RxPG News : ENT

New polymer gel may restore vocal cords

Fri, 15 Jul 2011 13:15:02 PST

( from http://www.rxpgnews.com ) A polymer gel, developed by scientists, could be implanted into scarred vocal cords to restore their normal functioning.

The gel, which mimics key traits of human vocal cords, could help millions of people with voice disorders. How it was developed is an interesting story.

In 1997, actress and singer Julie Andrews of 'The Sound of Music' fame lost her voice following a surgery to remove non-cancerous lesions from her vocal cords.

She approached Steven Zeitels, professor of laryngeal surgery at Harvard Medical School, for help. Zeitels was developing a new type of material that could be implanted into scarred vocal cords to restore their normal function.

In 2002, he enlisted the help of MIT's Robert Langer, professor in chemical engineering, an expert in developing polymers for biomedical applications, the journal Annals of Otology, Rhinology & Laryngology reports.

The team led by Langer and Zeitels has now developed a polymer gel with the help of former Massachusetts Institute of Technology researcher Sandeep Karajanagi. They hope to start testing in a small clinical trial next year, according to a Harvard statement.

About six percent of the US population has some kind of voice disorder, and the majority of those cases involve scarring of the vocal cords, says Karajanagi.

Many of those are children whose cords are scarred from intubation - during surgery, while others are victims of laryngeal cancer.

Other people who could benefit are those with voices strained from overuse, such as teachers. 'This would be so valuable to society, because every time a person loses their voice, say, a teacher, all of their contributions get lost to society,' Zeitels says.

Hearing loss rate in older adults climbs to more than 60 percent in national survey

Mon, 28 Feb 2011 05:00:00 PST

( from http://www.rxpgnews.com ) Nearly two-thirds of Americans age 70 and older have hearing loss, but those who are of black race seem to have a protective effect against this loss, according to a new study led by Johns Hopkins and National Institute on Aging researchers. These findings, published online Feb. 28 in the Journal of Gerontology: Medical Sciences, provide what is believed to be the first nationally representative survey in older adults on this often ignored and underreported condition.

Contrary to the view that hearing loss is of only minor importance in old age, study leader Frank Lin, M.D., Ph.D., assistant professor in the Division of Otology at Johns Hopkins University School of Medicine and a core faculty member in the Johns Hopkins Center of Aging and Health, says studies including his own have strongly linked it to other health problems, such as cognitive decline, dementia, and poorer physical functioning. And he notes that relatively little is known about risk factors that drive hearing loss.

To fill in some of the blanks, Lin and his colleagues analyzed data from the 2005-2006 cycle of the National Health and Nutrition Examination Survey, a research program that has periodically gathered health data from thousands of Americans since 1971. In the 2005-2006 cycle, the hearing of participants 70 years or older was checked using a test that determined whether they could detect tones in frequencies used in speech.

When the researchers analyzed the numbers from 717 volunteers, they found that about 63 percent had hearing loss that ranged from mild to severe. Mixing in demographic data showed that those who were older or male were more likely to have hearing loss or more severe hearing loss than younger or female subjects. The researchers also found that being black appeared to be protective. While about 64 percent of white subjects had hearing loss, only about 43 percent of black subjects did. After accounting for other factors that are associated with hearing loss like age and previous noise exposure, black participants had only a third of the chance of having hearing loss when compared with white participants.

Lin notes that he and his colleagues aren't sure why being black might prevent hearing loss, but they and other research teams have suggested that pigment produced by cells in the skin and inner ear might protect the inner ear by absorbing free radicals, among other mechanisms.

Despite the overwhelming number of older adults with hearing loss, the study found that only one-fifth use hearing aids, with only 3 percent of those with mild hearing loss taking advantage of these devices.

Any way you cut it, the rates of hearing aid use are phenomenally low, Lin says. He and his colleagues are currently planning a study to see whether hearing aid use could prevent some of the conditions connected to hearing loss.

2 drugs protect hearing better than 1

Wed, 23 Feb 2011 05:00:00 PST

( from http://www.rxpgnews.com ) Whether on a battlefield, in a factory or at a rock concert, noise-induced hearing loss is one of the most common hazards people face.

Researchers at Washington University School of Medicine in St. Louis have identified a low-dose, two-drug cocktail that reduces hearing loss in mice when given before they are exposed to loud noise. The drugs, already FDA-approved for other conditions, also treat hearing loss after noise exposure.

While both drugs are known to protect hearing on their own, this is the first study to test the two in combination.

We found they have synergy, says Jianxin Bao, PhD, research associate professor of otolaryngology at the School of Medicine. Two drugs at lower dosages can block more signaling pathways than one alone, improving results while reducing side effects. We got the idea from cancer and HIV studies that use multiple drugs at lower dosages.

Bao presented the work Feb. 21 in Baltimore at a meeting of the Association for Research in Otolaryngology.

In earlier work, Bao's group found that anticonvulsant drugs for treating epilepsy helped protect hearing in mice after exposure to loud noise. And other groups had determined that glucocorticoids, anti-inflammatory drugs often used to treat allergies and asthma, were also protective.

The reasons these drugs reduce noise-induced hearing loss are not well understood. But anticonvulsants are known to block calcium channels in nerve cells, and Bao's group speculates that the drug helps protect neuronal connections between hair cells and auditory neurons.

For this work, Bao and colleagues chose two drugs from the anti-epilepsy family and two from the glucocorticoid family.

We picked drugs that have fewer side effects and that can be chronically used, says Bao, also associate professor of audiology and communication sciences.

To test each drug's ability to prevent hearing loss, they gave various doses to mice two hours before exposing them to noise. To test treatment, they administered the drugs to different groups of mice 24 hours after noise exposure.

Three of the four drugs showed increasing protection with higher doses. And two of the drugs in combination, the anticonvulsant zonisamide and the glucocorticoid methylprednisolone, showed comparable hearing protection at much lower doses than when administered alone.

While the drugs do not prevent all hearing loss following sustained exposure to noise at 110 decibels, or about the sound of a chain saw, they can significantly reduce the loss by about 10 to 30 decibels.

In other words, a mouse with normal hearing might be able to hear a sound at 30 decibels. After exposure to loud noise, that mouse might only hear sounds that reach 50 decibels. But if that mouse were treated, it might be able to hear sounds at 40 decibels. In humans, protecting 5 or 10 decibels makes a difference in being able to hear everyday speech.

Bao says their next step is to test the drugs in animals that model human hearing more closely.

Award to honor pivotal career in speech research

Fri, 15 Oct 2010 04:00:00 PST

( from http://www.rxpgnews.com ) The American Speech-Language-Hearing Association (ASHA) has announced plans to award Dr. Emily Tobey of UT Dallas its prestigious Honors of the Association for her pioneering research and academic leadership.

Tobey holds the Nelle C. Johnston Chair in Communication Disorders in the School of Behavioral and Brain Sciences (BBS) and conducts much of her research in the Callier Center for Communication Disorders. In selecting her for its highest honor, ASHA cited her study of speech production by cochlear implant users, her groundbreaking studies in oral rehabilitation and brain imaging, and her many leadership roles. The award will be presented to Tobey and other recipients in November in Philadelphia.

Emily Tobey's research and service contributions to improving the life of those with hearing disorders and diseases is remarkable, Dr. William Yost, professor and chairman of speech and hearing science at Arizona State University, wrote in his letter supporting Tobey's nomination. Her body of work has been substantial and significant, which to me is the definition of what is meant by receiving Honors from ASHA.

Tobey said she is pleased to receive this special recognition from her fellow researchers and clinicians. Out of more than 140,000 ASHA members, only 200 have been awarded the Honors of the Association.

Although I receive this award as a personal award, it clearly is not, she said. The award represents the efforts of the Dallas Cochlear Implant Program, a joint enterprise between UT Dallas, UT Southwestern Medical Center and Children's Medical Center, to provide our community with a first-rate clinical and research team. I am proud to be associated with the team and thrilled by the recognition of our quality program.

Tobey has made some of the most important contributions concerning the longitudinal effects of cochlear implantation on children during her decades-long focus on speech production and oral language development in young people. Her work has been continuously funded by the National Institutes of Health (NIH) or other agencies since 1975, and she currently holds three active NIH grants.

After earning her PhD from City University of New York in 1981, her career took a new path when she became part of the team that helped organize the first Food and Drug Administration (FDA) clinical trials for cochlear implants. The prosthetic device was considered extremely controversial at the time, with no consensus of acceptance by the scientific community.

She soon became involved in the design and execution of national FDA clinical trials and was among the first investigators to be funded by the NIH to conduct investigations in deaf individuals receiving the devices. Her activities resulted in FDA approval of the devices for implantation in children in 1992 and their current use worldwide.

Tobey's recent research has expanded to include using the latest imaging techniques to study changes in brain function in adults who receive cochlear implants. This leading-edge work could help specialists determine underlying processes in the speech perception and production of adults who had normal hearing, lost hearing through deafness and regained auditory input with a cochlear implant.

Tobey has published peer-reviewed manuscripts with more than 155 professionals around the world during her career. She works directly on research efforts not only at UT Dallas, but also with John Hopkins School of Medicine, UT Southwestern Medical Center and many other institutions around the world.

Besides her direct involvement in research, Tobey also has helped raise awareness and encourage progress by taking on leadership and administrative posts with a variety of top professional organizations, such as ASHA and the Acoustical Society of America. She serves as associate provost at UT Dallas, assisting with faculty development, program review, diversity and community engagement.

Teaching has always been a top priority for Tobey, and she has launched the careers of many graduate students involved in the field of speech, language and hearing. Before joining UT Dallas, she was a professor at Louisiana State University Medical Center.

Tobey earned her bachelor's degree at New Mexico State University and her master's degree at Louisiana State, both in speech-language pathology.

ASHA's recognition of Emily Tobey for her career achievements is wonderful acknowledgement of her decades-long leadership in speech and hearing science, said Dr. Bert Moore, dean of BBS. There is no greater pleasure as an academic than being honored by one's peers, and this is the highest recognition bestowed by the leading organization in Emily's field. The University is the daily recipient of her many talents, and this award pleases her colleagues and me greatly.

Southampton to conduct UK's first cochlear implant operation to give sound in both ears

Thu, 26 Aug 2010 04:00:00 PST

( from http://www.rxpgnews.com ) The UK's first operation to fit a single cochlear implant capable of giving sound in both ears takes place this Friday (27 August), thanks to the work of the South of England Cochlear Implant Centre (SOECIC), based at the University of Southampton.

A cochlear implant is an electronic device that can help both adults and children who have a severe to profound hearing loss. It has two parts: an internal receiver/stimulator package and electrode array, and an external speech processor that looks like a hearing aid. The device uses small electrical currents to directly stimulate the hearing nerve, which then sends signals to the brain where they are interpreted as sound.

Julie Brinton, Joint Head of the Centre, comments: Over the past 20 years the South of England Cochlear Implant Centre has implanted over 500 people with different implants. Some adults and children have already received two implants, with one in each ear. The difference with the device being used on Friday is that, although information is delivered to each ear, there is only one implant.

Although around 40 of these devices have been implanted in patients in Europe, this is the first of its kind in the UK.

The operation will be carried out at Southampton General Hospital by Mike Pringle, Consultant Otolaryngologist based at Queen Alexandra Hospital in Portsmouth.

Mike Pringle says: This is different to other types of implant as it is one implant going into both ears. It's not unusual for children to have two implants, one in each ear, but adults usually just have one.

This type of device has an internal receiver/stimulator with two wires; one will go directly into one inner ear and the other will go over the top of the head, under the scalp, to reach the other inner ear. There will be a microphone on each ear collecting sounds from both sides.

The advantage is that it allows adults to have bilateral hearing. Having two ears working makes it easier to hear in noisy backgrounds and also helps with localisation, or hearing where sounds are coming from.

Also, because there is only one processor and one internal receiver stimulator this makes this device significantly cheaper than two separate implants.

The recipient of the implant is a 44-year old woman from the Isle of Wight. She has been deaf all her life and has used hearing aids until now.

Dr Helen Cullington, Clinical Scientist (Audiology) at the University of Southampton, adds: Following the surgery she will need to wait for four to six weeks before the device is tuned and she can begin to have auditory rehabilitation to encourage her listening with the new sensation she will experience.

There is an individual programme for each patient; a computer is used to assess the levels and frequencies of sound that the patient can hear and tune the implant accordingly. This is a very exciting opportunity for a deaf adult to obtain hearing in both ears.

Tinnitus study looks for cure to 'ringing in the ears'

Wed, 11 Aug 2010 04:00:00 PST

( from http://www.rxpgnews.com ) The NIH has granted a University of Texas at Dallas researcher and a university-affiliated biomedical firm $1.7 million to investigate whether nerve stimulation offers a long-term cure for tinnitus.

Described as a ringing in the ears, tinnitus affects 20 percent to 40 percent of recently returned military veterans and about 10 percent of all people over 65 years old. The U.S. Veterans Administration spends about $1 billion a year in disability payments related to tinnitus, said Dr. Michael Kilgard, associate professor in UT Dallas' School of Behavioral and Brain Sciences. The disorder causes mild irritation for some people but is disabling and painful for many others.

Kilgard will use his portion of the grant, $448,000 over two years, to continue testing whether vagus nerve stimulation (VNS) can retrain the brain to ignore the nerve signals that simulate ringing. The researchers in earlier tests found that VNS stimulation, when paired with the presentation of alternative tones, appeared to reverse the effects of tinnitus.

We're glad to get an opportunity to further our research on tinnitus, Kilgard said. This grant will support advances in our understanding of VNS treatment, and it will move the technological development forward so we can better deliver that therapy to patients.

The researchers plan to change the pattern for stimulation, increasing the frequency to see if more intensive therapy might reverse the effects of tinnitus faster. The primary aim of the new research is to accumulate enough data to design clinical trials using VNS to treat tinnitus in human subjects in the United States.

VNS previously translated successfully to humans for the treatment of epilepsy, depression and other neurological disorders.

The new grant resulted from the NIH's partnership with the federal government's Small Business Innovation Research program (SBIR). Part of the grant will go to Kilgard and his work in the lab, and the other portion will further research by MicroTransponder, a biomedical start-up company that works in conjunction with UT Dallas researchers and has helped bring in more than $6 million in grants in the past two years.

MicroTransponder is attempting to develop a less invasive method for delivering the electric charge that stimulates the vagus nerve in the neck. Currently, Kilgard uses wires attached to the neck to stimulate the nerve. The goal is to create a remotely controlled device similar to the technology used for toll tags on highways, Kilgard said.

Will Rosellini, a PhD student in neuroscience at UT Dallas, is CEO of MicroTransponder. Dr. Larry Cauller, associate professor of neuroscience, developed the neural interface technology that led to MicroTransponder. He is the company's chief science officer.

For medical devices, the ultimate goal is to have the least invasive procedure possible, but this is usually accomplished in an iterative fashion, with each new version being less invasive than the past, Rosellini said. The eventual goal is to have our SAINT System be injectable via a needle, but there are several intermediary versions of the device that must be developed and thoroughly tested before that will be possible.

Rosellini said Dr. Roger Miller, a scientific program director at the National Institute on Deafness and Other Communication Disorders, has been a champion of MicroTransponder's efforts to use VNS to combat tinnitus. Kilgard said Miller has been extremely helpful in advancing the new therapy closer to a clinical reality.

The VNS treatment would be an improvement over current therapies involving medications or counseling because it offers a possible permanent end to the condition, an actual cure instead of just a treatment, Kilgard said. Current therapies have limited success and frequently must be modified over time because they cease to be effective.

MicroTransponder and Kilgard now are working with researchers in Belgium to set up a protocol for conducting the first round of tests in humans. Less than half of therapies that are successful in animals prove successful when tested on people, Kilgard said.

We want to find out as much as we can about how well this works in rats. That is what this phase of the research is about, he said. Once we have that additional data, we can try out a similar therapy on humans, and we hope to find this offers a permanent end to their tinnitus discomfort.

Dr. Bert Moore, dean of the School of Behavioral and Brain Sciences, said UT Dallas' relationship with MicroTransponder continues to yield results.

The story behind this research is a wonderful example of how investigators such as Drs. Cauller and Kilgard, exploring basic mechanisms of how the brain adapts and learns, can collaborate with corporate partners to develop new technologies to address a variety of human problems, he said. This is the goal of our research mission at UT Dallas, creating new knowledge so that we can impact and improve people's lives.

Genetic modifier in Usher syndrome will lead to better diagnosis

Fri, 11 Jun 2010 04:00:00 PST

( from http://www.rxpgnews.com ) Gothenburg, Sweden: Usher syndrome (USH), an inherited condition involving both hearing and vision loss, is not a simply recessively inherited disease, a scientist will tell the annual conference of the European Society of Human Genetics today (Saturday). Dr. Hanno Bolz, Associate Medical Director of the Bioscientia Centre for Human Genetics, Ingelheim, Germany, and active in teaching and research at the University Hospital of Cologne, will say that his team's research challenges the traditional view that USH was inherited as a single gene disorder, and shows that it may result from at least two different genetic mutations. This could lead to more accurate diagnosis of this condition, which is responsible for up to 10% of all cases of childhood deafness and 50% of all deaf/blindness in adults.

Some USH patients have only one mutant copy of an Usher gene, which in itself is insufficient to explain a recessive disease, and there is often an unexplained variability of the visual characteristics of the condition, even between close family members. Dr. Bolz's team, including scientists from Cologne University, Germany and zebrafish researchers from the University of Oregon, USA, decided to look for additional USH genes and genetic modifiers that could be involved in disease causation.

We became interested in researching sensory diseases such as Usher syndrome because they can be very debilitating and affect people at a young age, said Dr. Bolz. Despite extensive research into USH, there is currently no effective treatment for it.

Apart from linkage studies of recessive disease, where a particular trait or disease characteristic is traced within a family, another way of identifying genes linked to disease is to analyse genes that encode proteins which are similar to the proteins involved in the disorder being studied. Using a genome-wide database search, the team identified a gene, PDZD7, which encoded a protein with striking similarity to the proteins whirlin and harmonin, both known to be involved in USH.

We found that some patients with only a single mutation of the gene responsible for the condition, GRP98, also had a mutant copy of PDZD7, and that this gene interacts with proteins involved in USH, said Dr. Bolz. We were able to validate these findings in transgenic zebrafish, and to show that PDZD7 localises to cilia, thus providing further confirmation that USH is a retinal ciliopathy.

Cilia are antenna-like protuberances that project from cells and are often involved in sensory activity such as vision, hearing or smell. Genetic mutations can affect their proper functioning, and these defects in turn affect critical signalling pathways essential to cell development. As a result, cilia defects are involved in many diseases which produce multiple symptoms.

Diagnosis of USH is complicated, the scientists say. At present it is normally related to clinical symptoms, such as childhood hearing impairment and the vision disease retinitis pigmentosa in the first or second decade of life. Retinitis pigmentosa affects the layer of light-sensitive tissue in the retina and vision loss occurs as the light-sensing cells gradually deteriorate, causing blind spots which eventually merge to produce tunnel vision and sometimes total blindness.

A recipe for hearing: Sensory hair cells made from stem cells

Thu, 13 May 2010 04:00:00 PST

( from http://www.rxpgnews.com ) After ten years of effort, researchers reporting in the May 14th issue of the journal Cell, a Cell Press publication, say they have found a way to coax embryonic stem cells as well as reprogrammed adult cells to develop into sensory cells that normally reside in the mammalian inner ear. Those mechanosensitive sensory hair cells are the linchpin of hearing and balance.

Assuming their recipe can be further perfected to reliably generate hair cells in the millions, it opens the door to detailed molecular studies on the cells and new insight into the molecular basis for hearing, according to the researchers. That's especially significant, says Stefan Heller of Stanford University School of Medicine, because the inner ear shelters the last of our senses for which the molecular basis is unknown.

That understanding could also set researchers on a path to discovering new ways to prevent or correct hearing loss by encouraging hair cells' regeneration. After all, the researchers say, our inability to regenerate lost hair cells is the major reason for the permanence of hearing loss as well as certain balance disorders.

Scientists have been left in the dark on the molecular basis for hearing in large part because hair cells are relatively scarce by comparison to other sensory cells, Heller explains. Our inner ears harbor about 30,000 sensory hair cells in total in two different types, few of which can be dissected out of the inner ear and kept alive for study. (Compare that to the 120 million photoreceptors in the retina, all of which can be isolated rather easily.)

Heller's team long ago realized that one solution to this problem was to use stem cells as a source for generating new hair cells, and now they've got the recipe. They have devised what they refer to as a stepwise guidance protocol for making the hearing cells, starting with either mouse embryonic stem cells or induced pluripotent stem (iPS) cells, which are stem cell-like cells derived from adult mouse cells.

The researchers first directed the stem cells to become ectodermal cells capable of responding to ear-inducing growth factors. They then subjected those so-called otic progenitor cells to varying differentiation conditions until they found one that led to the formation of cell clusters displaying hair cell-like characteristics. The key ingredients were chemicals known as a fibroblast growth factors or FGFs, which others had shown to be both sufficient and necessary for ear development.

The hair cell-like cells display all the markers associated with bona fide hair cells, they report. Closer examination of the cells under a scanning electron microscope showed that they were developing bundled structures highly reminiscent of the hair-like tufts of stereocilia that lend hair cells their name.

Most importantly, further study showed that the hair cell-like cells also respond to mechanical stimulation by producing currents like hair cells should. (Fluid inside the ear moves in response to vibration, setting hair cells in motion. Those sensory cells then convert that mechanical signal into an electrical one that is ultimately sent to the brain.)

The reprogrammed cells acted like immature, as opposed to adult, hair cells, they found. For instance, the cells responded with currents regardless of whether they were pushed or pulled; mature hair cells only work in one direction.

In addition to its promise for further scientific study, the new protocol could have clinical implications.

The fact that in vitro-generated hair cell-like cells display mechanosensitivity demonstrated that generation of replacement hair cells from pluripotent stem cells is feasible, a finding that justifies the development of stem cell-based treatment strategies for hearing and balance disorders, the researchers conclude.

Heller says that perhaps the most promising strategy for taking advantage of this new source for hair cells is high-throughput screening for drugs to awaken mammals' lost ability to regenerate hair cells in the way that other animals can.

For some reason, we've lost this mechanism but it must still be there somehow, Heller says. We need to find ways to activate it.

Increased risk of hearing loss with regular analgesic use

Mon, 01 Mar 2010 12:48:22 PST

( from http://www.rxpgnews.com ) In a study published in the March 2010 issue of The American Journal of Medicine, researchers determined that regular use of aspirin, acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) increases the risk of hearing loss in men, particularly in younger men, below age 60.

Hearing loss is the most common sensory disorder in the US, afflicting over 36 million people. Not only is hearing loss highly prevalent among the elderly, but approximately one third of those aged 40-49 years already suffer from hearing loss. Even mild hearing loss can compromise the ability to understand speech in the presence of background noise or multiple speakers, leading to social isolation, depression, and poorer quality of life.

Investigators from Harvard University, Brigham and Women's Hospital, Vanderbilt University and the Massachusetts Eye and Ear Infirmary, Boston looked at factors other than age and noise that might influence the risk of hearing lose. Aspirin, acetaminophen, and ibuprofen are the 3 most commonly used drugs in the US. The ototoxic effects of aspirin are well known and the ototoxicity of NSAIDs has been suggested, but the relation between acetaminophen and hearing loss has not been examined previously. The relationship between these drugs and hearing loss is an important public health issue.

Study participants were drawn from the Health Professionals Follow-up Study, which tracked over 26,000 men every 2 years for 18 years. A questionnaire determined analgesic use, hearing loss and a variety of physiological, medical and demographic factors.

For aspirin, regular users under 50 and those aged 50-59 years were 33% more likely to have hearing loss than were nonregular users, but there was no association among men aged 60 years and older. For NSAIDs, regular users aged under 50 were 61% more likely, those aged 50-59 were 32% more likely, and those aged 60 and older were 16% more likely to develop hearing loss than nonregular users of NSAIDs. For acetaminophen, regular users aged under 50 were 99% more likely, regular users aged 50-59 were 38% more likely, and those aged 60 and older were 16% more likely to have hearing loss than nonregular users of acetaminophen.

Writing in the article, Sharon G. Curhan, MD, ScM, Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, and colleagues state, "Regular use of analgesics, specifically aspirin, NSAIDs, and acetaminophen, might increase the risk of adult hearing loss, particularly in younger individuals. Given the high prevalence of regular analgesic use and health and social implications of hearing impairment, this represents an important public health issue."

Specialists in hearing, HIV come together to study AIDS patients

Tue, 03 Nov 2009 05:00:00 PST

( from http://www.rxpgnews.com ) Specialists in HIV and in hearing at the University of Rochester Medical Center are teaming up to measure the hearing of people with AIDS.

The five-year study is believed to be the first large study of its kind testing the hearing of people with HIV/AIDS and comparing the results with those from people without HIV. The new effort, supported by a $1.9 million grant from the National Institute on Deafness and Other Communication Disorders, is the result of collaboration between hearing experts and experts on HIV and AIDS.

The study is led by Amneris Luque, M.D., associate professor of Medicine and director of Strong Memorial Hospital's AIDS Clinic, which provides care for more than 900 patients. The project brings together experts in the nervous system and the immune system, both of which are involved in many types of hearing loss. The first of 360 participants who will take part in the study enrolled last week.

Luque will work closely with hearing researcher Robert Frisina, Ph.D., professor of Otolaryngology, Biomedical Engineering, and Neurobiology and Anatomy. Frisina's team, which is based at the Medical Center as well as the National Technical Institute for the Deaf, is widely regarded as one of the premier groups in the world looking at age-related hearing loss.

Luque says that since AIDS was recognized nearly three decades ago, hearing loss among some patients has been reported. However, these reports have been scattered and unconfirmed.

There has not been a systematic study looking at hearing function in people with HIV, said Luque. If there is hearing impairment, it could be related to the disease itself; it might be related to infections that our patients with AIDS are prone to getting; or it might be related to the medications used to treat the disease.

Luque notes that some scientists have found evidence that people with HIV/AIDS may be aging prematurely compared to people without HIV. The team will look closely at whether a similar acceleration of aging may play a role in the hearing of people with HIV.

In addition, of course, many people without HIV also experience hearing loss. Causes of hearing loss can include noise exposure, medications used to treat conditions like cancer or other infections, or heredity. Sorting out those causes from other processes unique to people with HIV is challenging.

We're trying to tease out what is happening in people with HIV, said Luque. Is there something inherent about the infection that may be involved in hearing loss?

Participants in the study will undergo periodic, rigorous testing of their hearing. Scientists will study patients at various stages of HIV infection, including some infected people known as long-term non-progressors or elite controllers, people in whom the infection hasn't advanced even without medication.

The team will compare the results in HIV/AIDS patients to results in healthy people who have had similar hearing tests conducted at the International Center for Hearing and Speech Research, where Frisina is associate director. That database includes extensive information about the hearing of more than 1,400 healthy people who have had similar testing done.

Lehigh researcher awarded $1.8 million NIH grant

Tue, 17 Mar 2009 04:00:00 PST

( from http://www.rxpgnews.com ) BETHLEHEM, PA, March 17, 2009 -- Lehigh University assistant professor of neuroscience Michael Burger has been awarded a $1.8 million grant from the National Institutes of Health's (NIH) National Institute on Deafness and Other Communication Disorders for his research entitled Efferent Inhibitory Mechanisms in Binaural Processing. The five-year grant will allow Burger to build upon the preliminary data he first collected under a grant he received from the Deafness Research Foundation for his work on Efferent Function in Sound Localization Processing.

I'm very excited about this grant because it provides the funds to ensure the long-term viability of my lab and gives me the resources I need to attack my research agenda, says Burger. It's very validating to have people in my field appreciate my work and my approach to auditory neuroscience.

Burger is interested in how the auditory system processes sound information. The ear and the brain work in tandem to determine the location of sound, relying on a specialized neural circuit in the brain devoted to the process. The brain is able to compute where sound comes from by determining when a sound wave strikes each ear. Auditory neurons can detect the tiny microsecond differences in arrival time of a sound between the two ears. This system also has to function over a wide range of sound intensities, making this computation particularly challenging.

I am extremely impressed with the way Mike investigates fundamental cell-to-cell processes in deciphering how the brain detects the location of sounds, says Murray Itzkowitz, professor and chair of Lehigh's biological sciences department. While the hearing health implications of his research are clear, I see his program as providing a model to explore many complex aspects of brain function and that too explains why the NIH is so interested in his program.

The research centers on the question of how cellular, synaptic, and systems level properties are integrated to allow sensory neurons to extract and represent features of the acoustic environment. The grant will enable Burger to further explore how the inhibitory components of the circuit influence processing in each brain area involved in computing sound source location.

Burger and the other members of his lab work with chickens, which have brain circuitry similar to human brain structures. Chickens also serve as good developmental models because researchers are able to study hearing at any stage. Over the long term, Burger hopes to use the findings gleaned from his work with chickens to build a mechanistic understanding of sound localization circuitry in vertebrate systems.

Burger first began studying hearing at a bat auditory neuroscience lab while a Ph.D. student at the University of Texas at Austin and later started working with birds as a senior postdoctoral fellow at the Department of Otolaryngology-Head and Neck Surgery at the University of Washington. In 2005, he was awarded a prestigious Alexander von Humboldt Research Fellowship at the University of Munich. Burger joined the Lehigh faculty in 2006.

While this research may be fundamental in nature, its contributions could play a significant role in clinical applications. Understanding how normal brain circuits function can help develop or improve prosthetic devices such as cochlear implants. These electronic devices substitute for damaged structures in the ear that may not function properly, and can restore hearing to deaf patients.

New iPod listening study shows surprising behavior of teens

Wed, 18 Feb 2009 05:00:00 PST

( from http://www.rxpgnews.com ) A new study involving iPods and teenagers by the University of Colorado at Boulder and Children's Hospital Boston indicates teenagers who receive pressure from their peers or others to turn down the volume of their iPods instead turn them up higher.

The study also showed that teen boys listen louder than teen girls, and teens who express the most concern about the risk for and severity of hearing loss from iPods actually play their music at higher levels than their peers, said CU-Boulder audiologist and doctoral candidate Cory Portnuff, who headed up the study. Such behaviors put teens at an increased risk of music-induced hearing loss, he said.

The results of the study, conducted by Portnuff and Associate Professor Kathryn Arehart of CU-Boulder's speech, language and hearing sciences department and Brian Fligor, director of diagnostic audiology at Children's Hospital Boston, were presented at the annual Hearing Conservation Conference held in Atlanta last week. Children's Hospital Boston is the teaching hospital of Harvard Medical School.

Other findings from the study indicated teens play their music louder than young adults, and teens may inaccurately perceive how loud they are playing their music. The good news, said Portnuff, is that teens in the study who understand the benefits of listening at a lower volume have less of a risk for hearing loss.

We really don't a have good explanation for why teens concerned about the hearing loss risk actually play their music louder than others, he said. But we do know that teens who knew what the benefits were of listening at lower levels had less hearing loss risk, which is why we believe targeted education is the key.

Portnuff said the new study indicated a relatively small percentage of teens -- somewhere between 7 and 24 percent -- listen to their iPods and MP3 players at risky levels. We don't seem to be at an epidemic level for hearing loss from music players, Portnuff said.

The new findings regarding the sound volumes selected by music-playing teens today are similar to findings 20 years ago when Walkman audio cassette players first came onto the market, Portnuff said. One of the concerns we have today is that while Walkmans back then operated on AA batteries that usually began to run down after several hours, teenagers today can listen to their iPods for up to 20 hours without recharging them.

A 2006 study by Portnuff and Fligor indicated a typical person can safely listen to an iPod for 4.6 hours per day at 70 percent volume using stock earphones. But listening to music at full volume for more than five minutes a day using stock earphones increased the risk of hearing loss in a typical person, according to the study.

The 2006 study also concluded that individuals can safely listen to iPods for 90 minutes a day with stock earphones if the volume is at 80 percent of maximum levels without greatly increasing the risk of hearing loss, he said.

Loud music can potentially damage delicate hair cells in the inner ear that convert mechanical vibrations, or sound, to electrical signals that the brain interprets as sound, said Portnuff. Over time, the hair cells can become permanently damaged and no longer work, producing hearing loss.

Everyone does not share the same risk of hearing loss, he said. Some people are born with tougher ears that allow them to listen to music relatively safely for longer periods. In contrast, those with tender ears may suffer ear damage even if they follow MP3 listening recommendations. There is really no way of knowing which people are more prone to damage from listening to music, he said.

Damage to hearing occurs when a person is exposed to loud sounds over time, said Portnuff. The risk of hearing loss increases as sound is played louder and louder for long durations, so knowing the levels one is listening to music at, and for how long, is extremely important. The new study included about 30 volunteers from the Denver-Boulder area.

UQ research finds speech disorders can be assessed from a distance

Sun, 11 Jan 2009 05:00:00 PST

( from http://www.rxpgnews.com ) There should be no barriers to providing high-quality speech pathology services, according to University of Queensland PhD graduate Dr Anne Hill.

Completed through UQ's School of Health and Rehabilitation Sciences, Dr Hill's research found speech and language disorders could be validly and reliably assessed over the internet using a telerehabilitation application.

Having worked clinically with people living with an acquired neurogenic communication disorder, I saw how frustrating it was for both the person with the communication disorder and the clinician if access to these services was restricted due to issues of caseload, distance or mobility issues, she said.

Telerehabilitation seems particularly well-suited to Australia, with our widely dispersed population and rural and remote communities.

This form of service delivery may help alleviate some of the access problems experienced by those living in rural and remote areas, as well as the metropolitan population restricted by mobility issues.

While Dr Hill was already won over by the potential benefits of telerehabilitation, she felt an academic investigation finding evidence of its success was important before introduction to the speech-language pathology profession.

Using a UQ-built telerehabilitation device, the study assessed 86 patients with various speech and language disorders, such as dysarthria, aphasia and apraxia of speech.

Each participant was also assessed using the traditional face-to-face method, allowing Dr Hill to gather comparative data and measure the validity and reliability of remote assessment.

Two speech pathologists conducted simultaneous rating of the face-to-face and telerehabilitation assessment of the participants, she said.

One of the two speech pathologists was randomly assigned to lead the assessment, either in the telerehabilitation environment or the face-to-face environment, while the other speech pathologist became a silent scorer of the assessment in the alternative environment.

This methodology allowed for the direct comparison between the telerehabilitation and face-to-face assessments, which is important in the development of evidence-based guidelines.

Telerehabilitation has the potential to address the major issues of service delivery in future decades, such as resolving inequities in access to rehabilitation services and meeting the increased demand for services due to an expanding ageing population.

Furthermore, telerehabilitation holds some promise for the further development of community-based chronic disease/disorder management protocols and providing cost-effective, functionally appropriate, high quality rehabilitation to all.

The introduction of telerehabilitation to the profession of speech-language pathology unlocks an exciting new era of research which blends clinical and technological innovation to better understand and serve those living with a communication disorder.

Future research will be limited only by our imagination in applying evolving technology to rehabilitation.

A new comprehensive clinical guideline for benign paroxysmal positional vertigo

Sat, 01 Nov 2008 03:52:08 PST

( from http://www.rxpgnews.com ) Head and Neck Surgery Foundation (AAO-HNSF) will issue a comprehensive clinical guideline to help healthcare practitioners identify and treat patients with benign paroxysmal positional vertigo (BPPV), one of the most common underlying conditions that cause dizziness. The guideline emphasizes evidence-based recommendations on managing BPPV, the most common vestibular (inner ear) disorder in adults.

BPPV is a disorder that causes feelings of vertigo, dizziness, and nausea. Episodes of BPPV can be brought on by abrupt changes in movement, like standing up or turning the head suddenly. The condition usually begins to affect people after the age of 50, but it can affect younger patients.

"Approximately 5.6 million medical appointments per year in the United States can be attributed to complaints of dizziness," said Neil Bhattacharyya, MD, chair of the multidisciplinary BPPV Guideline Panel. "We know now that anywhere from 17 to 42 percent of these patients will ultimately receive a diagnosis of BPPV. Unfortunately, proper diagnosis and treatment for those suffering is often delayed due to a lack of standardized diagnostic steps and relative unawareness of effective treatment options."

The primary purposes of the new AAO-HNSF guideline, for patients 18 years and older, are to improve quality of care and outcomes for BPPV by improving the accurate and efficient diagnosis of the condition, reducing the inappropriate use of suppressant medications, decreasing the inappropriate use of ancillary tests such as radiographic imaging and vestibular testing, and to promote the use of effective repositioning maneuvers for treatment.

Expenses relating to the diagnosis and treatment of BPPV cost the U.S. healthcare system approximately $2 billion per year. Additionally, 86 percent of patients suffer some interrupted daily activities and lost days at work because of BPPV.

Fortunately, BPPV can be readily diagnosed by clinicians in an outpatient setting most of the time without complicated testing. Once a proper diagnosis has been made, simple, effective treatment options are available to relieve symptoms quickly.

Some of the key recommendations of the guideline include:

A strong recommendation for clinicians to diagnose posterior semicircular canal BPPV with an office-based diagnostic test (the Dix-Hallpike maneuver, detailed within the guideline).
A recommendation for clinicians to also test patients for a second type of BPPV affecting the lateral semicircular canal when initial testing is not conclusive (using the supine roll test).
Clinicians should differentiate BPPV from other causes of imbalance, dizziness, and vertigo.
Clinicians should question patients with BPPV for factors that modify management including impaired mobility or balance, CNS disorders, a lack of home support, and increased risk for falling. These recommendations will help prevent some of the dangerous morbidities from BPPV.
Clinicians should not obtain radiographic imaging or vestibular testing in a patient diagnosed with BPPV, unless the diagnosis is uncertain or there are additional symptoms or signs unrelated to BPPV that warrant testing.
Clinicians should not routinely treat BPPV with vestibular suppressant medications such as antihistamines or benzodiazepines.
For patients who are initial treatment failures, clinicians should evaluate them for persistent BPPV or underlying peripheral vestibular or CNS disorders.
Clinicians should counsel patients regarding the impact of BPPV on their safety, the potential for disease recurrence, and the importance of follow-up.

The guideline was created by a multidisciplinary panel of clinicians representing the fields of otolaryngology, audiology, emergency medicine, physical medicine and rehabilitation, geriatrics,physical therapy, family physicians, neurology, and chiropractics.

Seniors with vocal problems want treatment but aren't getting it

Tue, 23 Sep 2008 04:00:00 PST

( from http://www.rxpgnews.com ) DURHAM, N.C. -- The breathy, hoarse voice of senior citizens is often thought to be a normal sign of aging. But doctors at the Duke Voice Care Center say that's a false perception that needs to change. And they've discovered that it may partially explain why seniors who want treatment for the condition aren't seeking it.

That's a problem, added Seth Cohen, M.D., a Duke otolaryngologist and the study's lead author, because voice and swallowing concerns can lead to serious quality of life issues including anxiety, depression and social withdrawal.

Nearly 20 percent of the 248 octogenarians studied by the Duke researchers had dysphonia, the medical term for hoarseness, weakness or loss of voice. Fourteen percent had dysphagia or painful swallowing. Approximately three-quarters of the respondents (77.6% for dysphonia and 79.4% for dysphasia) had not sought treatment, even though more than half (55.9%) expressed interest in getting help.

Voice and swallowing issues are serious concerns and people who want medical care are not getting it, says Cohen of the research presented at the 2008 annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery in Chicago, IL. Is it because they have so many medical problems and these issues are getting pushed aside or overlooked? We don't know. What we do know is these medical concerns have a huge impact on quality of life, and more people should be aware of the treatments available and be able to obtain help.

Previous studies have reported that nearly one-fourth of elderly individuals believe vocal and swallowing problems are a normal part of aging, a perception found to be even more common among those who actually suffer. The Duke physicians surmise that this may lead some elderly people to accept their difficulties and not seek treatment.

Half of those surveyed were unaware that treatment existed. This is a concern, says Cohen, because symptoms of depression were found to be more common among those affected. And, previous studies have reported a connection between the conditions and increased depression, anxiety and social withdrawal.

Cohen says part of the problem may be under-recognition. Primary care physicians are currently managing the many medical conditions elderly people routinely face, and may not be discussing voice and swallowing problems with their patients. Regardless, Cohen says the Duke data shows that needs to change.

Our results highlight the need for better education of the general public and, primary care providers, Cohen said. Whether this effort leads to increased awareness and/or better outcomes for these patients is the basis of further study. But for now, we know these problems have a significant negative impact on quality of life, and obtaining appropriate treatment can make a big difference.

15 years later: Landmark hearing study follows up on farm youth

Fri, 12 Sep 2008 04:00:00 PST

( from http://www.rxpgnews.com ) (MARSHFIELD, Wis.) A landmark study conducted by Marshfield Clinic Research Foundation (MCRF) 15 years ago found that an educational intervention improved hearing protection use among farm youth.

Now, the National Institute for Occupational Safety and Health (NIOSH) has awarded a $954,000 grant to MCRF to study the same group of Wisconsin youth to see whether the increase in hearing protection use continued into adulthood and whether it helped preserve hearing.

The new three-year study, under principal investigator Barbara Marlenga, Ph.D., a research scientist with the National Farm Medicine Center, MCRF, will evaluate whether the hearing conservation program conducted with farm youth from 1992-96 had long-term benefits to safeguard hearing. Although that hearing conservation program was conducted with farm youth, the impact of this new study goes beyond agriculture.

Noise-induced hearing loss is a big problem, Marlenga said. Ten million people in the United States, including children and youth, have hearing loss from exposure to loud noises. More than 30 million workers are estimated to be exposed to hazardous noise levels on the job.

The key to success of this study is the ability to find the youth from the original research study. To qualify for the new grant, Marlenga and colleagues conducted a search for the earlier participants, who are now young adults. She sent a letter to a small number of the original 689 people, then called and asked if they would be willing to participate in the follow-up study. More than 90 percent of those she reached said they would participate in a follow-up study.

Being able to demonstrate that we could find these students again was crucial to our receiving the grant, Marlenga said. This is a one-of-a-kind opportunity to see if early intervention to prevent noise-induced hearing loss can be sustained over time, Marlenga said.

The original study, conducted through the National Farm Medicine Center, MCRF, evaluated hearing of 689 farm youth in junior and senior high school. Half the participants received ear muffs and ear plugs as well as training and reminders about using hearing protection over a four-year period while in school. At the end of the study, the youth who received the intervention reported using hearing protection more consistently than those who did not, although at that time hearing test results were not different between the two groups.

After 15 years, we expect that noise-induced hearing loss would start to appear, Marlenga said.

For the new study, participants will again have their hearing tested and will be asked about work and home noise exposure. They will also be asked about hearing protection and whether they are required to use it where they work.

Study aims to improve sex education for deaf pupils

Wed, 11 Jun 2008 04:00:00 PST

( from http://www.rxpgnews.com ) British parents are to be quizzed about their children's sex education in a unique study that hopes to improve the way the subject is taught to deaf pupils.

The University of Manchester's Audiology and Deafness team is recruiting parents of both deaf and hearing primary school children for its research on children's sex and relationship education (SRE).

The researchers hope their findings will make SRE more accessible for deaf children and, at a later stage, they plan to devise a fun, non-threatening computer game to explore how much deaf as well as hearing children know about issues related to growing up.

Study leader Sarah Suter, in the School of Psychological Sciences, said: The way SRE is taught in the UK varies from school to school as only selected areas, like HIV and reproduction, are mandatory; other areas of the SRE curriculum, such as feelings and relationships, are guidance only.

Teaching SRE to deaf children brings additional challenges, as deaf pupils don't 'overhear' and may miss comments and discussions that inform hearing children.

In addition some deaf children have a very literal understanding of words and may have difficulty understanding the many terms in SRE that require subtle interpretation. They may understand the textbook terms but not the euphemisms that also arise in such discussions.

It is important we address these issues as children who do not get a good SRE are more vulnerable to abuse because they may not recognise inappropriate behaviour or that their boundaries are being crossed.

Senior lecturer in education of the deaf, Wendy McCracken, added: There is some evidence to suggest that deaf children are much more likely to face abuse. They may not have the language to be able to tell someone that it is happening and also may lack awareness that the behaviour is inappropriate.

It is a human right to understand what is happening to your body and what you can expect from relationships. A good SRE keeps children safe.

The three-year study is the first to investigate the sexual and relationships knowledge of deaf children. Other studies have investigated the understanding of deaf college students and adults in the US, but none has ever explored the SRE of deaf youngsters.

It is important that we know what children are learning at primary-school age before puberty and the effects of raging hormones kick in, added Wendy.

The study reflects a Government push on social and emotional development of children. Let's not forget that the UK has the highest teen pregnancy rate in Europe, so the subject clearly needs to be addressed.

The team will ask parents in an informal discussion, or by means of an online or postal survey, about what they know of their child's SRE, whose responsibility they believe it is and if they give their children SRE at home. The questions are factual and address what their knowledge of their child's SRE is, rather than whether they believe SRE is right or wrong.

The website also provides parents with the names and contact details of organisations that can help them with any problems, including the National Deaf Children's Society, the parent-support charity ParentlinePlus and the UK's leading sexual health charity, the Family Planning Association.

Gene therapy involving antibiotics may help patients with Usher syndrome

Mon, 02 Jun 2008 04:00:00 PST

( from http://www.rxpgnews.com ) Barcelona, Spain: A new approach to treating vision loss caused by Type 1 Usher syndrome (USH1), the most common condition affecting both sight and hearing, will be unveiled by a scientist at the annual conference of the European Society of Human Genetics tomorrow (Tuesday 3 June). Ms Annie Rebibo Sabbah, from the Genetics Department of the Rappaport Faculty of Medicine, Technion, Haifa, Israel, will tell the conference that preliminary results using a class of drugs called aminoglycosides, commonly used as antibiotics, had had promising effects in vitro and in cell culture.

Usher syndrome is a recessively- inherited disease; in order to have it, the child must receive a mutated form of the Usher gene from each parent. Approximately 3 to 6 percent of all children who are deaf and another 3 to 6 percent of children who are hard-of-hearing have it. In developed countries, about four babies in every 100,000 births have Usher syndrome. Children born with USH1 begin to develop visual problems in early childhood, and these develop quickly into an eye disorder called retinitis pigmentosa, which leads to complete blindness.

There are several types of genetic mutations involved in Usher syndrome, including nonsense mutations. In this type of mutations the protein in the cell is totally absent, or abnormally short, says Ms Rebibo Sabbah. We knew that aminoglycosides are able to suppress nonsense mutations to the extent that, instead of having no protein at all, or a truncated protein, the cell receives a partial amount of full-length protein that may even be functional.

As a model, the team took several nonsense mutations of the PCDH15 gene, which is responsible for Usher syndrome. They were able to produce partial suppression of the mutations in vitro using commercial aminoglycosides. The same result was achieved ex vivo, in cultured cells.

Despite these promising results, the most serious problem with aminoglycosides is their toxicity to the kidney and to the inner ear, which causes limitation in their use, says Ms Rebibo Sabbah. We worked with Professor Baasov, from the Chemistry Faculty at Technion, to try to develop a new compound based on aminoglycosides which will have reduced toxicity.

The scientists tested more than forty new compounds for ones which had the same efficacy as aminoglycosides, but with significantly reduced toxicity. We found a very promising new compound, called NB30, says Ms Rebibo Sabbah. After testing its toxicity in cells, we tried it in mice. In both models the toxicity was significantly reduced compared to the current commercially available aminoglycosides, and we could also see the suppressive activity of NB30 in the cultured cells.

This is the first time that this therapeutic strategy has been tried in Usher syndrome, the scientists say. Their next step will be to look at another USH1- related gene (CDH23) and its nonsense mutations in both humans and mice.

Our final aim is to prove that a nonsense mutation underlying Usher syndrome is capable of being suppressed in vivo in a mouse model by commercial aminoglycosides, and also by NB30, and that this will have a positive effect on retinal function, says Ms Rebibo Sabbah. We will also continue to look for new compounds with improved characteristics.

The researchers hope that their work will lead to therapy to delay the progression and, indeed, the onset, of vision loss in patients with USH1. Because it is recessively inherited, this is a particularly invidious disease, says Ms Rebibo Sabbah.

In most cases, parents have normal hearing and vision and are not aware that they are carriers of Usher syndrome. But if they have a child with another carrier, they will have a one in four chance of having a child with the condition at each birth. We need urgently to find an effective treatment.

Zebrafish may help solve ringing in vets' ears

Wed, 30 Apr 2008 04:00:00 PST

( from http://www.rxpgnews.com ) CHICAGO -- Ernest Moore, an audiologist and cell biologist at Northwestern University, developed tinnitus -- a chronic ringing and whooshing sound in his ears -- twenty years ago after serving in the U.S. Army reserves medical corps. His hearing was damaged by the crack of too many M16 rifles and artillery explosions. He suspects his hearing also suffered from hunting opossum with rifles as a kid on his grandmother's farm in Tennessee.

Ever since his ears began ringing, Moore has been researching a cure. He's at the forefront of just a small band of such scientists in the country. There's a lot riding on his work.

Half of the soldiers returning from Iraq and Afghanistan exposed to explosive devices suffer from tinnitus. The major cause is exposure to loud noises, which can damage and destroy hair cells of the inner ear. It's the number one war-related disability.

Nearly 400,000 troops collected disability for service-related tinnitus in 2006, which cost $539 million in 2006. The number climbs nearly 20 percent each year. It could hit $1 billion by 2011, according to the American Tinnitus Association.

An additional 12 million Americans have tinnitus severe enough to seek medical attention. In about two million of those cases, patients are so debilitated they can't function normally.

Despite the widespread suffering, there has only been a paltry $3 million allotted for public and private research. As a tinnitus researcher, Moore feels like a cross between Rodney Dangerfield and Sisyphus.

It's been tough to snare research money from the small purse and hard to garner respect for tinnitus. Ears don't bleed from tinnitus, Moore explained. It's a hidden problem. It's not obvious and dramatic like a heart attack or cancer -- although it torments its sufferers. Only one out of ten grant proposals he submits each year have been funded.

The research itself is challenging because Moore can't ask mice and rats if their ears are ringing. Now, he's working with zebrafish (yes, they do have ears, which are remarkably similar to humans' ears.) He's been able to cause ringing in their ears -- he thinks -- by exposing them to certain drugs and tracking their erratic swimming on video. Moore then looks at the cells in their ears to see if the electrical firing has increased, an early sign of damage and tinnitus. His early findings show an increased firing.

Then Moore attempts to block this effect with drugs to return the cells to their normal activity. In preliminary research, it appears the drugs he has tested do slow down the increased electrical firing or tinnitus-like behavior of the hair cells in the ear.

Moore is beginning to meet with doctors to discuss launching a clinical trial to test these drugs for patients with tinnitus.

If these drugs are found to be safe -- and some are already on the market for other uses -- and if they are found to have efficacy in humans, then they might be used to treat an individual's tinnitus, Moore said.

If the hair cell is not totally damaged -- just beginning to break down, and you administer these drugs, you might be able to prevent it from further damage and interfere with the cells' ability to generate tinnitus, he explained.

Tinnitus finally will begin to get some respect in April when The Department of Defense 2008 Appropriations Bill will open up $50 million in new research funding for tinnitus related to service in the armed forces. Ernest Moore has applied to launch the clinical trial with the drugs he has used with the zebrafish.

Lend me your ears -- and the world will sound very different

Sun, 13 Jan 2008 05:00:00 PST

( from http://www.rxpgnews.com ) Recognising people, objects or animals by the sound they make is an important survival skill and something most of us take for granted. But very similar objects can physically make very dissimilar sounds and we are able to pick up subtle clues about the identity and source of the sound. Scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) are working out how the human ear and the brain come together to help us understand our acoustic environment. They have found that the part of the brain that deals with sound, the auditory cortex, is adapted in each individual and tuned to the world around us. We learn throughout our lives how to localise and identify different sounds. It means that if you could hear the world through someone else's ears it would sound very different to what you are used to.

The research, which features in the current issue of BBSRC Business, could help to develop more sophisticated hearing aids and more effective speech recognition systems.

The research team at the University of Oxford, led by Dr Jan Schnupp, have studied the auditory cortex of the brain and discovered that its responses are determined not merely by acoustical properties, like frequency and pitch, but by statistical properties of the sound-scape. In the world loudness and pitch are constantly changing. The random shifts in sounds are underpinned with a statistical regularity. For example, subtle and gradual changes are statistically more regular than large and sudden changes. Dr Schnupp's team have found that our brains are adapted to the former; the neurons in the auditory cortex appear to anticipate and respond best to gradual changes in the soundscape. These are also the patterns most commonly found in both nature and musical compositions.

Dr Schnupp, a research leader at the University of Oxford Auditory Neuroscience Group, said: Our research to model speech sounds in the lab has shown that auditory neurons in the brain are adaptable and we learn how to locate and identify sounds. Each person's auditory cortex in their brain is adapted to way their ears deliver sound to them and their experience of the world. If you could borrow someone else's ears you would have real difficulty in locating the source of sounds, at least until your brain had relearned how to do it.

Dr Schnupp has also found that the auditory cortex does not have neurons sensitive to different aspects of sound. When the researchers look at how the auditory cortex responds to changes in pitch, timbre and frequency they saw that most neurons reacted to each change. Dr Schnupp explains: In the closely related visual cortex there are different neurons for processing colour, form and motion. In the auditory cortex the neurons seem to overwhelmingly react to several of the different properties of sound. We are now investigating how they distinguish between pitch, spatial location and timbre.

If we can understand how the auditory cortex has evolved to do this we may be able to apply the knowledge to develop hearing aids that can blot out background noise and speech recognition systems that can handle different accents.

The Oxford team's current project is using BBSRC funding to fit trained ferrets with harmless auditory implants. The animals are trained to respond to different sounds and the implants enable the team to observe the auditory neurons as the ferret responds to different sounds.

Professor Nigel Brown, BBSRC Director of Science and Technology, said: This research is revealing how our senses work and how the brain interprets information from the ears. These BBSRC-funded studies of a fundamental biological process may bring exciting developments in helping people with hearing and other disabilities.

Scientists search for brain center responsible for tinnitus

Fri, 05 Oct 2007 04:00:00 PST

( from http://www.rxpgnews.com ) BUFFALO, N.Y. -- For the more than 50 million Americans who experience the phantom sounds of tinnitus -- ringing in the ears that can range from annoying to debilitating -- certain well-trained rats may be their best hope for finding relief.

Researchers at the University at Buffalo have studied the condition for more than 10 years and have developed these animal models, which can �tell� the researchers if they are experiencing tinnitus.

These scientists now have received a $2.9 million five-year grant from the National Institutes of Health to study the brain signals responsible for creating the phantom sounds, using the animal models, and to test potential therapies to quiet the noise.

The research will take place at the Center for Hearing and Deafness, part of the Department of Communicative Disorders and Sciences in the university�s College of Arts and Sciences. Richard Salvi, Ph.D., director of the center, is principal investigator. Scientists from UB�s Department of Nuclear Medicine and from Roswell Park Cancer Institute in Buffalo are major collaborators on portions of the project.

Tinnitus is caused by continued exposure to loud noise, by normal aging and, to a much lesser extent, as a side effect of taking certain anti-cancer drugs. It is a major concern in the military: 30 percent of Iraq and Afghanistan combat veterans suffer from the condition.

�For many years it was thought that the buzzing or ringing sounds heard by people with tinnitus originated in the ear,� Salvi said. �But by using positron emission tomography [known as PET scanning] to view the brain activity of people with tinnitus at UB, we�ve been able to show that these phantom auditory sensations originated somewhere in brain, not in the ear. That changed the whole research approach.�

Salvi and colleagues discovered that when the brain�s auditory cortex begins receiving diminished neural signals from the cochlea, the hearing organ, due to injury or age, the auditory cortex �turns up the volume,� increasing weak neural signals from the cochlea. Increasing the volume of these weak signals may be experienced as the buzzing, ringing, or hissing characteristic of tinnitus. Currently there is no drug or treatment that can abolish these phantom sounds.

Over the past decade, Salvi�s team has developed the animal models, allowing the researchers to explore the neurophysiological and biological mechanisms associated with tinnitus, the major focus of this new study. Ed Lobarinas, Ph.D., and Wei Sun, Ph.D., in the Department of Communicative Disorders and Sciences, developed the models.

One of the major goals of the project is to try to identify the neural signature of tinnitus -- what aberrant pattern of neural activity in the auditory cortex is associated with the onset of tinnitus. In another study phase, the researchers will assess neural activity throughout the entire brain using a radioactive tracer, fluorodeoxyglucose (FDG), which is taken up preferentially into regions of the brain that are highly active metabolically.

The third phase of the study involves the use of potential therapeutic drugs to suppress salicylate- or noise-induced tinnitus. In early studies, the researchers have been able to modulate some ion channels with one unique compound, and have been able to completely eliminate aspirin-induced tinnitus using the highest doses of the compound. This phase involves collaboration with scientists at NeuroSearch Pharmaceuticals in Denmark.

Music training linked to enhanced verbal skills

Mon, 24 Sep 2007 04:00:00 PST

( from http://www.rxpgnews.com ) EVANSTON, Ill. --- Music training, with its pervasive effects on the nervous system�s ability to process sight and sound, may be more important for enhancing verbal communication skills than learning phonics, according to a new Northwestern University study.

Musicians use all of their senses to practice and perform a musical piece. They watch other musicians, read lips, and feel, hear and perform music, thus, engaging multi-sensory skills. As it turns out, the brain�s alteration from the multi-sensory process of music training enhances the same communication skills needed for speaking and reading, the study concludes.

�Audiovisual processing was much enhanced in musicians� brains compared to non-musician counterparts, and musicians also were more sensitive to subtle changes in both speech and music sounds,� said Nina Kraus, Hugh Knowles Professor of Communication Sciences and Neurobiology and director of Northwestern�s Auditory

Neuroscience Laboratory, where the work was performed. �Our study indicates that the high-level cognitive processing of music affects automatic processing that occurs early in the processing stream and fundamentally shapes sensory circuitry.�

The nervous system�s multi-sensory processing begins in the brainstem, an evolutionarily ancient part of the brain previously thought to be relatively unmalleable.

�Musicians have a specialized neural system for processing sight and sound in the brainstem, the neural gateway to the brain,� said Northwestern doctoral student Gabriella Musacchia, lead author of the study.

For many years, scientists believed that the brainstem simply relayed sensory information from the ear to the cortex, a part of the brain known for cognitive processing.

Because the brainstem offers a common pathway that processes music and speech, the study suggests that musical training conceivably could help children develop literacy skills and combat literacy disorders.

The study, �Musicians Have Enhanced Subcortical Auditory and Audiovisual Processing of Speech and Music,� will be published online the week of Sept. 24 in the Proceedings of the National Academy of Sciences (PNAS). The co-investigators are Gabriella Musacchia, Mikko Sams, Erika Skoe and Nina Kraus.

Study participants, who had varying amounts of musical training or none at all, wore scalp electrodes that measured their multi-sensory brain responses to audio and video of a cellist playing and a person speaking.

The data showed that the number of years that a person practiced music strongly correlated with enhanced basic sound encoding mechanisms that also are relevant for speech. Beyond revealing super-accurate pitch coding vital to recognizing a speaker�s identity and emotional intent, the study showed enhanced transcription of timbre and timing cues common to speech and music.

�The study underscores the extreme malleability of auditory function by music training and the potential of music to tune our neural response to the world around us, � Kraus said.

Previous research has shown brainstem transcription errors in some children with literacy disorders.

Since music is inherently more accessible to children than phonics, the new research suggests, music training may have considerable benefits for engendering literacy skills.

Sensitivity of brain center for 'sound space' defined

Thu, 20 Sep 2007 04:00:00 PST

( from http://www.rxpgnews.com ) While the visual regions of the brain have been intensively mapped, many important regions for auditory processing remain �uncharted territory.� Now, researchers at the Hebrew University of Jerusalem and elsewhere have identified a region responsible for a key auditory process � perceiving �sound space,� the location of sounds, even when the listener is not concentrating on those sounds.

The findings settle a controversy in earlier studies that failed to establish the auditory region, called the planum temporale, as responsible for perception of auditory space by default.

The researchers, led by Dr. Leon Y. Deouell, of the Psychology Department and the Interdisciplinary Center for Neural Computation of the Hebrew University, and colleagues from the University of California, Berkeley, and the Weizmann Instititue of Science published their findings in the Sept. 20 issue of the journal Neuron, published by Cell Press. Working with Deouell on the project were Aaron S. Heller of University of California, Berkeley; Prof. Rafael Malach of the Weizmann Institute of Science; and Prof. Mark D�Esposito and Prof. Robert T. Knight of the University of California, Berkeley

Studies by other researchers had shown that the planum temporale was activated when people were asked to perform tasks in which they located sounds in space. However, many researchers believed that the region was responsible only for intentional processing of such information. And, in fact, previous studies had failed to establish that the planum temporale was responsible for automatic, nonintentional representation of spatial location.

Previous research done by Dr. Deouell and others has shown that some patients with brain damage may be specifically impaired in this function. Understanding how the normal brain machinery for this function is organized may help to understand why it breaks down and eventually how to mend it.

In their work, Deouell and colleagues used an improved experimental design that enabled them to more sensitively determine the brain�s auditory spatial location center. For example, they presented their human subjects with sounds against a background of silence, used headphones that more accurately reproduced sound location, and used noise with a rich spectrum, which has been shown to be more readily locatable in space. They also used sounds recorded from microphones placed in each subject�s own ears, and then played the same sounds back, thus tailoring the sounds specifically to the subjects� own head and ears.

In their experiments, they presented bursts of the noise to the volunteers wearing the headphones while the subjects� brains were scanned by functional magnetic resonance imaging. In this widely used brain-scanning technique, harmless magnetic fields and radio waves are used to image blood flow in brain regions, which reflects brain activity in those locations.

The subjects were instructed to ignore the sounds. And, to divert their attention, they either watched a movie with the sound turned off or were given a simple button-pushing task.

When the position of the noise bursts was varied in space, the researchers found that the planum temporale in the subjects� brain was, indeed, activated. What�s more, the greater the number of distinct sound locations subjects heard during test runs, the greater the activity in the planum temporale.

The researchers thus concluded that their experiments �suggest that neurons in this region represent, in a nonintentional or preattentive fashion, the location of sound sources in the environment.�

Brain center for 'sound space' identified

Wed, 19 Sep 2007 04:00:00 PST

( from http://www.rxpgnews.com ) While the visual regions of the brain have been intensively mapped, many important regions for auditory processing remain terra incognita. Now, researchers have identified the region responsible for a key auditory process�perceiving �sound space,� the location of sounds. The findings settle a controversy in earlier studies that failed to establish the auditory region, called the planum temporale, as responsible for perceiving auditory space.

Leon Y. Deouell and colleagues published their findings in the September 20, 2007 issue of the journal Neuron, published by Cell Press.

Studies by other researchers had shown that the planum temporale was activated when people were asked to perform tasks in which they located sounds in space. However, many researchers believed that the region was responsible only for intentional processing of such information. And in fact, previous studies had failed to establish that the planum temporale was responsible for automatic, nonintentional representation of spatial location.

However, Deouell and colleagues used an improved experimental design that enabled them to more sensitively determine the brain�s auditory spatial location center. For example, they presented their human subjects with sounds against a background of silence, used headphones that more accurately reproduced sound location, used noise with a rich spectrum which has been shown to be more readily locatable in space, and created an individually tailored sound space for each subject by using sounds previously recorded directly from the subjects� own ears.

In their experiments, they presented bursts of the noise to the volunteers wearing the headphones while the subjects� brains were scanned by functional magnetic resonance imaging. In this widely used brain-scanning technique, harmless magnetic fields and radio waves are used to image blood flow in brain regions, which reflects brain activity in those locations.

The subjects were instructed to ignore the sounds. And, to divert their attention, they either watched a movie with the sound turned off or were given a simple button-pushing task.

When the position of the noise bursts was varied in space, the researchers found that the planum temporale in the subjects� brain was, indeed, activated. What�s more, the greater the number of distinct sound locations subjects heard during test runs, the greater the activity in the planum temporale.

The researchers concluded that their experiments �suggest that neurons in this region represent, in a nonintentional or preattentive fashion, the location of sound sources in the environment.� They wrote that �Space representation in this region may provide the neural substrate needed for an orientation response to critical auditory events and for linking auditory information with information acquired through other modalities.�

Researcher developing new method for hearing loss assessment

Thu, 06 Sep 2007 04:00:00 PST

( from http://www.rxpgnews.com ) WEST LAFAYETTE, Ind. - A Purdue University researcher is working on a new technique to diagnose hearing loss in a way that more accurately reflects real-world situations.

The traditional way to assess speech understanding in people with hearing loss is to put them in a quiet room and ask them to repeat words produced by one person they can't see, said Karen Iler Kirk, a professor of speech, language and hearing sciences. The goal of our research is to develop new tests that reflect more natural listening situations with visual cues, different background noises, voice quality, dialects and speaking rates. This is a more accurate way to predict how people perceive speech in the real world and, therefore, can help us determine appropriate therapy and interventions, such as cochlear implants.

The better the diagnostic tool we have to make such decisions, the better we can serve our patients.

Kirk received a $2.8 million grant from the National Institute on Deafness and Other Communication Disorders for the five-year project to develop two new audiovisual and multi-talker sentence tests that expand upon the traditional spoken word recognition format that has been used since the 1950s. One test is for adults and the other for children. More than 1,000 people ages 4-65 will participate in the study.

The traditional spoken word recognition format has been used to determine the need for some sensory aids, such as hearing aids, which are used to amplify sound, Kirk said. However, it is not the best method for assessing the benefits of other sensory aids, such as the more expensive cochlear implants.

A cochlear implant is an electronic device that can provide a sense of sound to someone who is deaf or severely hard of hearing. The device, which is surgically implanted, picks up and processes sound that is converted into electric impulses that are sent to the auditory nerve. More than 100,000 people worldwide have received cochlear implants, and more health insurance companies are paying for the surgery and therapy, Kirk said.

This project also is expanding word lists from the traditional monosyllabic words to a greater range of words based on how often they are used and lexical density - the number of words phonetically similar to the target. For example, the word cat has a number of lexical neighbors such as bat, cap, cut and scat. A word like banana may be used frequently but has few words that sound similar.

The 10 diverse speakers, who are recording more than 6,000 sentences combined, will not be producing perfectly articulated speech.

It's important to use sentence materials that are produced by different speakers because in the real world, we do not listen to just one person, Kirk said.

In addition to the auditory component, the materials will be presented in a visual format so listeners can see and hear the phrase.

This is really important because hearing-impaired people often have great difficulty understanding speech if they are just listening. Seeing the face and following lip reading cues can help someone understand the intended message, she said.

Participants will be tested in auditory-only, visual-only or auditory plus visual modalities. At the end of the project, DVDs containing the test, as well as instruction booklets, data-gathering forms and a manual for data interpretation, will be available to professionals.

Another benefit from this study will be the raw data generated.

Just collecting information from 1,000 individuals and measuring how well they perform on these tests gives us tremendous information that is not available elsewhere, Kirk said.

'Holy Grail' of hearing: True identity of pivotal hearing structure is revealed

Wed, 05 Sep 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Our ability to hear is made possible by way of a Rube Goldberg-style process in which sound vibrations entering the ear shake and jostle a successive chain of structures until, lo and behold, they are converted into electrical signals that can be interpreted by the brain. Exactly how the electrical signal is generated has been the subject of ongoing research interest.

In a study published in the September 6 issue of the journal Nature, researchers have shed new light on the hearing process by identifying two key proteins that join together at the precise location where energy of motion is turned into electrical impulses. The discovery, described by some scientists as one of the holy grails of the field, was made by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health (NIH), and the Scripps Research Institute in La Jolla, CA.

�This team has helped solve one of the lingering mysteries of the field,� says James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. �The better we understand the pivotal point at which a person is able to discern sound, the closer we are to developing more precise therapies for treating people with hearing loss, a condition that affects roughly 32.5 million people in the United States alone.�

When a noise occurs, such as a car honking or a person laughing, sound vibrations entering the ear first bounce against the eardrum, causing it to vibrate. This, in turn, causes three bones in the middle ear to vibrate, amplifying the sound. Vibrations from the middle ear set fluid in the inner ear, or cochlea, into motion and a traveling wave to form along a membrane running down its length. Sensory cells (called hair cells) sitting atop the membrane �ride the wave� and in doing so, bump up against an overlying membrane. When this happens, bristly structures protruding from their tops (called stereocilia) deflect, or tilt to one side. The tilting of the stereocilia cause pore-sized channels to open up, ions to rush in, and an electrical signal to be generated that travels to the brain, a process called mechanoelectrical transduction.

Most scientists believe that the channel gates are opened and closed by microscopic bridges�called �tip links��that connect shorter stereocilia to taller ones positioned behind them. If scientists could determine what the tip links are made of, they�d be one step closer to understanding what causes the channel gates to open. This is no easy feat, however, because stereocilia are extremely small, scarce, and difficult to handle. Several proteins had been reported to occur at the tip link in earlier studies, but results have been conflicting to this point.

New study finds infant hearing test results may predict sudden infant death syndrome

Thu, 26 Jul 2007 04:00:00 PST

( from http://www.rxpgnews.com ) SEATTLE: July 26, 2007 One of the greatest medical mysteries of our time has taken a leap forward in medical understanding with new study results announced by Dr. Daniel D. Rubens of Childrens Hospital and Regional Medical Center in Seattle. Rubens study published in July, 2007 in Early Human Development found all babies in a Rhode Island study group who died of Sudden Infant Death Syndrome (SIDS) universally shared the same distinctive difference in their newborn hearing test results for the right inner ear, when compared to infants who did not have SIDS. This is the first time doctors might be able to identify newborns at risk for SIDS by a simple, affordable and routine hearing test administered shortly after birth. In the study, medical records and hearing tests of 31 babies who died from SIDS in Rhode Island were examined and compared to healthy babies. Rhode Island has a particularly robust database of newborn hearing test data.

The cause of SIDS, known around the world as crib death and cot death, has eluded physicians and grieving parents for centuries. Responsible for many previously unexplainable deaths of infants usually two to four months old and striking boys more than girls, SIDS causes tragic, sudden death in approximately 1 in 1,000 newborns world-wide, making it the largest cause of death in young infants. In the United States approximately 3,600 deaths each year were attributed to SIDS from 1992-1999, according to an April, 2004 article in Archives of Pediatric and Adolescent Medicine. Death occurs during sleep, seemingly with no warning and no previous symptoms. Changes in infant care have been promoted including the Back to Sleep program discouraging sleeping on the stomach, and avoiding exposure to cigarette smoke. Various causes have been suggested, including disturbances in respiratory control and infant overheating, but to date nothing has proven conclusive.

It is known that the inner ear contains tiny hairs that are involved in both hearing and vestibular function. Rubens proposes that vestibular hair cells are important in transmitting information to the brain regarding carbon dioxide levels in the blood. He postulates that injury to these cells will disrupt respiratory control, playing a critical role in predisposing infants to SIDS.

The SIDS infants in Rubens study showed a consistent four point lower score in their standard newborn hearing tests, across three different sound frequencies in the right ear, when compared to babies that didnt die from SIDS. Additionally, healthy infants typically test stronger in the right ear than the left. However, in each of the SIDS cases studied, the right ear tested lower than the left, reversing the test results of healthy babies.

This discovery opens a whole new line of inquiry into SIDS research, said Rubens. For the first time, its now possible that with a simple, standard hearing test babies could be identified as at risk for SIDS, allowing preventative measures to be implemented in advance of a tragic event. He urges further research, adding We must now fully explore all aspects of inner ear function and SIDS, and analyze testing frequencies higher than those currently tested by newborn hearing screen centers.

Previous groundbreaking SIDS research at Seattle Childrens Hospital and Regional Medical Center took place during the 1970s, when Dr. Bruce Beckwith was one of the first researchers to describe features of SIDS that can identify cases during autopsy, distinguishing SIDS deaths from other causes of infant death. Beckwith is highly recognized in the body of SIDS research, making his work among the most significant earlier published findings about the condition. It has been my great privilege to follow in Dr. Beckwiths footsteps with this new discovery that creates the possibility of identifying SIDS infants before tragedy strikes, said Rubens. Each new breakthrough brings us closer to making SIDS a condition of the past.

Ability to listen to 2 things at once is largely inherited, says twin study

Tue, 17 Jul 2007 06:00:00 PST

( from http://www.rxpgnews.com ) Your ability to listen to a phone message in one ear while a friend is talking into your other ear?and comprehend what both are saying?is an important communication skill that?s heavily influenced by your genes, say researchers of the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health. The finding, published in the August 2007 issue of Human Genetics, may help researchers better understand a broad and complex group of disorders?called auditory processing disorders (APDs)?in which individuals with otherwise normal hearing ability have trouble making sense of the sounds around them.

?Our auditory system doesn?t end with our ears,? says James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. ?It also includes the part of our brain that helps us interpret the sounds we hear. This is the first study to show that people vary widely in their ability to process what they hear, and these differences are due largely to heredity.?

The term ?auditory processing? refers to functions performed primarily by the brain that help a listener interpret sounds. Among other things, auditory processing enables us to tell the direction a sound is coming from, the timing and sequence of a sound, and whether a sound is a voice we need to listen to or background noise we should ignore. Most people don?t even realize they possess these skills, much less how adept they are at them. Auditory processing skills play a role in a child?s language acquisition and learning abilities, although the extent of that relationship is not well understood.

To determine if auditory processing skills are hereditary, NIDCD researchers studied identical and fraternal twins who attended a national twins festival in Twinsburg, OH, during the years 2002 through 2005. A total of 194 same-sex pairs of twins participated in the study (138 identical pairs and 56 fraternal pairs), representing ages 12 through 50. All twins received a DNA test to confirm whether they were identical or fraternal and a hearing test to make sure they had normal hearing.

If a trait is purely genetic, identical twins, who share the same DNA, will be alike nearly 100 percent of the time, while fraternal twins, who share roughly half of their DNA, will be less similar. Conversely, if a trait is primarily due to a person?s environment, both identical and fraternal twins should have roughly the same degree of similarity, since most twins grow up in the same household.

The volunteers took five tests that are frequently used to identify auditory processing difficulties in children and adults. In three of the tests, volunteers listened as two different one-syllable words or nonsense syllables (short word fragments such as ba, da, and ka) were played into their right and left ears simultaneously, and then tried to name both words or syllables. In two other tests, volunteers listened to digitally altered one-syllable words played into the right ear and tried to identify the word. One test artificially filtered out high-pitched sounds, which tended to obscure the consonants, while the other sped up the word.

In all but the filtered-words test, researchers found a significantly higher correlation among identical twins than fraternal twins, indicating that differences in performance for those activities had a strong genetic component. Participants showed the widest range of abilities on those tests in which they were asked to identify competing words or nonsense syllables entering each ear?called dichotic listening ability. The tests in which different one-syllable words were played simultaneously into each ear showed the widest degree of variation as well as the highest correlation among twins, especially identical twins. As much as 73 percent of the variation in dichotic listening ability was due to genetic differences, a magnitude that is comparable to well-known inherited traits such as type 1 diabetes and height. Conversely, the ability to understand the filtered words showed high correlation among all twins, indicating that variation in that skill is primarily due to differences in environment.

Scientists believe that problems with dichotic listening ability are often due to a lesion or disconnect between the brain's right and left hemispheres. When we listen to someone talking, speech entering the right ear travels in large part to the left side of the brain, where language is processed. Speech entering the left ear travels first to the right side of the brain before crossing to the brain?s language center on the left side by way of the corpus callosum, a pathway connecting the brain's right and left hemispheres.

Today?s finding that normal twins show such wide variation in their dichotic listening abilities, and that the differences are mostly due to genetic variation, adds a new perspective to our understanding of auditory processing disorders. These disorders may affect as many as seven percent of school-aged children in the United States and often appear alongside language and learning disorders, including dyslexia. APDs also affect older adults and stroke victims and can limit the successfulness of hearing aids in the treatment of hearing loss. The researchers suggest that scientists may be able to fine-tune their understanding of what an APD is and the role these disorders play in the development of language and learning disorders.

Nearly 90 percent of babies receive recommended newborn screening tests

Tue, 10 Jul 2007 04:00:00 PST

( from http://www.rxpgnews.com ) WHITE PLAINS, N.Y., JULY 11, 2007 Nearly 90 percent of all babies born in the United States more than double the percentage in 2005 live in states that require screening for at least 21 life-threatening disorders, according to the latest March of Dimes Newborn Screening Report Card.

The March of Dimes endorsed the 2004 report of the American College of Medical Genetics (ACMG) that calls for every baby born in the U.S. to be screened for 29 genetic or functional disorders. If diagnosed early, all of these devastating conditions can be successfully managed or treated to prevent severe consequences.

Two years ago, only 38 percent of infants were born in states that required screening for at least 21 of these 29 core conditions. As a result of four years of intensive advocacy efforts by March of Dimes chapters and their partners, that percentage has increased to 87.5, or about 3.6 million babies.

While this important expansion of newborn screening is very good news for families, the lives of 500,000 newborns who still arent tested hang in the balance, said Dr. Jennifer L. Howse, president of the March of Dimes. Despite the pleas of parents, clinicians and advocacy groups the United States still lacks consistent federal guidelines for newborn screening. Babies must be screened, to receive immediate treatment necessary to survive and lead healthy lives. The lack of federal guidelines makes it difficult for states to get support for needed legislation.

In states that do not follow the ACMG recommendations, the March of Dimes staff and volunteers continue to work with governors, legislatures, and parent groups to advocate for expanded newborn screening on a state-by-state basis.

In Pennsylvania, newborn screening is offered at most hospitals, but it is not required by law. Therefore it is not a guarantee and, potentially, screening could be eliminated or reduced.

Massachusetts had been a leader in newborn screening when, in the early 1960s, it became the first state to routinely screen all newborns for PKU (phenylketonuria), an inherited metabolic disorder that, if untreated, causes severe mental retardation. But today Massachusetts requires screening for only 12 of the 29 core conditions.

Nationwide, a discouraging 6.1 percent of babies are born in states that required screening for only 10 to 20 of the core conditions and 6.2 percent of newborns will get screening for fewer than 10 conditions. Disparities in state newborn screening programs mean some babies may die or develop brain damage or other severe complications because they are not identified in time for effective treatment, said Dr. Howse.

All babies across America should receive the benefits of being screened for all of these 29 treatable conditions, said Dr. Howse.

At present, 13 states and the District of Columbia require screening for all 29 core, treatable, conditions. While most states are working to meet that goal, Montana, Kansas and West Virginia, enacted legislation this year requiring all babies be screened for all of the core conditions. Their programs will be implemented next year.

Other states overcame remarkable challenges in order to provide for the health of their smallest citizens. For example, Louisiana, which still is recovering from the devastating hurricanes of 2005, requires screening for 28 of the core conditions.

This is the fifth consecutive year the March of Dimes has analyzed state-by-state newborn screening requirements, creating a snapshot of the nations progress toward improving the health of newborns. The March of Dimes contracted with the National Newborn Screening and Genetics Resource Center to survey each states newborn screening requirements.

The snapshot shows that the nation is on target to meet the March of Dimes goal of having all babies screened for 20 or more of the recommended panel of genetic disorders by 2008.

Global community listens to TAU genetic researcher at EU Conference on Hearing Loss

Mon, 09 Jul 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Paris -- Prof. Karen Avraham, chair of the department of human molecular genetics and biochemistry at Tel Aviv Universitys Sackler School of Medicine, represented EuroHear, a consortium of 25 European, Israeli and U.K.-based research teams, at the European Union conference Hearing and Seeing: European Research to Fight Deafness and Blindness, held at Pariss College de France on July 2-3, 2007.

This fall, Prof. Avraham will visit the U.S. to address several Tel Aviv University:American Council groups on recent advances in research on hearing impairments.

Twelve-million euros have gone into funding EuroHear, in which Prof. Avraham plays a leading role. Attendees at the conference included hundreds of academic representatives as well as patient groups, who are instrumental in helping scientists understand hearing loss.

The goal of the conference was to bring researchers and clinicianswho work with both the deaf and blindtogether to discuss each others strides made in their respective fields, says Prof. Avraham, an American-Israeli geneticist, whose field of research, genomics, aims to investigate the biological mechanisms that can lead to hearing disorders.

Prof. Avrahams work demonstrates that geopolitical issues should not be allowed to hinder academic and scientific collaboration. Her laboratory at the Sackler School has taken part in discovering key genes for deafness in the Israeli and Palestinian populations, and she and her Palestinian colleague, Prof. Moien Kanaan, have helped identify 10 hearing loss genes. Together, as an example of Tel Aviv Universitys commitment to cross-cultural academic and scientific collaboration, they have become renowned for a unique multi-disciplinary approach to understanding the high incidence of genetic deafness among Palestinian children.

Most recently, Prof. Avrahams group discovered a new type of hearing impairment in Israel called OTSC4, a form with onset in early adulthood. Other landmark gene discovery research conducted by Prof. Avraham is now being used in diagnostic tests for patients.

Knowing ones genetic predisposition can certainly aid clinicians today and in the future for developing treatments and therapies to prevent further loss. One day a cure may be within reach, says Prof. Avraham, stressing the importance of international academic collaboration to achieve further breakthroughs.

European figures for hearing impairment mirror those in the U.S. Over 10% of the E.U. population suffer some kind of hearing impairment, a figure rising to 40% among those 75 and older. The costs of managing hearing loss are considerable in terms of physical, social and mental well-being, educational development and employment. Early identification of such conditions and intervention are therefore extremely important for society.

Study examines cause of hearing loss for patients with certain genetic disease

Tue, 03 Jul 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Patients with the genetic disorder von Hippel-Lindau disease may suddenly experience hearing loss because of a tumor-associated hemorrhage in the inner ear, according to a study in the July 4 issue of JAMA.

Endolymphatic sac tumors (ELSTs; tumors of the inner ear) occur sporadically but may be associated with von Hippel-Lindau disease (VHL; a genetic disease characterized by the development of blood vessel tumors in the retina of the eye and in the brain; lesions and cysts can also develop in other parts of the body). ELSTs are associated with significant dysfunction of hearing and balance, including sudden irreversible hearing loss. The mechanisms and appropriate treatments for this disorder are not well understood.

John A. Butman, M.D., Ph.D., of the National Institutes Health, Bethesda, Md., and colleagues conducted a study, between May 1990 and December 2006, to determine the mechanisms underlying hearing loss in patients with ELSTs. Clinical findings and audiologic data were correlated with magnetic resonance imaging and computed tomography imaging studies. Thirty-five patients with von Hippel-Lindau disease and ELSTs in 38 ears were identified.

the most common ELSTassociated clinical finding in this series was hearing loss. Sensorineural hearing loss (SNHL) occurred in 31 patients (89 percent) or 34 of the affected ears (89 percent) and was frequently moderate or profound. Other less frequent ELSTassociated findings included aural [pertaining to the ear or hearing] fullness, aural pain, facial nerve weakness, and aural pain and facial nerve weakness combined, the authors write.

Intralabyrinthine (inner ear) hemorrhage was found in 11 of 14 ears with sudden SNHL but occurred in none of the 17 ears with gradual SNHL or normal hearing. Tumor size was not related to SNHL.

Based on the relationship between the imaging and clinical findings in these patients, 3 distinct mechanisms (either alone or in combination) may account for the audiovestibular [hearing and balance] morbidity associated with ELSTs. These include direct invasion of the otic capsule [embryonic cartilage capsule that surrounds the inner ear mechanism and develops into bony tissue] by tumor, intralabyrinthine hemorrhage, and endolymphatic hydrops [recurrent vertigo accompanied by ringing in the ears and deafness].

Since significant audiovestibular dysfunction, including deafness, can occur suddenly in a manner that is not related to tumor size, early surgical intervention may be warranted. While this study does not address the effectiveness of surgical resection, several small operative series indicate that complete resection of ELSTs can be curative, can alleviate vestibular symptomatology, and can be performed with hearing preservation and minimal morbidity.

Therefore, in patients with hearing and imaging evidence of an ELST, surgery may be considered after weighing its potential risks to prevent neurologic worsening or amelioration of symptoms. To intervene early, prompt diagnosis based on clinical and imaging findings is necessary. Thus, serial clinical evaluations and high-resolution MRI and CT imaging to detect small ELSTs or intralabyrinthine hemorrhage are warranted in patients with VHL, the authors conclude.

Difficulty identifying odors may predict cognitive decline

Mon, 02 Jul 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Older adults who have difficulty identifying common odors may have a greater risk of developing problems with thinking, learning and memory, according to a report in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Mild cognitive impairmentor a decline in thinking, learning and memory abilitiesis increasingly recognized as a precursor to Alzheimers disease, according to background information in the article. Impairments in the ability to recognize odors have been associated with more rapid cognitive decline and also with the development transition from mild cognitive impairment to Alzheimers disease. However, little is known about factors that predict the development of mild cognitive impairment.

Robert S. Wilson, Ph.D., of Rush University Medical Center, Chicago, and colleagues studied 589 older adults (average age 79.9) who did not have cognitive impairment in 1997. At that time, the participants took a smell identification test, during which time 12 familiar odors were placed under their nose. They were asked to match each odor to one of four possible alternatives, and were scored from one to 12 based on the number of correct responses. At the beginning of the study and again every year for up to five years, the participants underwent a clinical evaluation that included a medical history, neurological examination and testing of their cognitive function.

During the study, 177 individuals (30.1 percent) developed mild cognitive impairment. Risk of developing mild cognitive impairment increased as odor identification decreased, so that those who scored below average (eight) on the odor identification test were 50 percent more likely to develop the condition than those who scored above average (11). This association did not change when stroke, smoking habits or other factors that might influence smell or cognitive ability were considered. Impaired odor identification was also associated with lower cognitive scores at the beginning of the study and with a more rapid decline in episodic memory (memory of past experiences), semantic memory (memory of words and symbols) and perceptual speed.

The neurobiological bases of age-associated olfactory dysfunction are uncertain, the authors write. Evidence suggests that even before the symptoms of Alzheimers disease develop, hallmark tangles develop in certain areas of the brain that may be associated with the processing of smells. Because difficulty identifying odors is associated with other neurological diseases, including Parkinsons disease, other mechanisms are likely involved. Further clinicopathological and clinicoradiological research on age-related olfactory dysfunction is needed, they continue.

Among older persons without manifest cognitive impairment, difficulty in identifying odors predicts subsequent development of mild cognitive impairment, the authors conclude. The findings suggest that olfactory dysfunction can be an early manifestation of Alzheimers disease and that olfactory assessment may be useful for early disease identification.

Promising results from first gene therapy clinical trial for Parkinson's disease reported

Thu, 21 Jun 2007 04:00:00 PST

( from http://www.rxpgnews.com ) NEW YORK (June 21, 2007) -- In what could be a breakthrough in the treatment of neurological disease, a team led by physician-scientists at NewYork-Presbyterian Hospital/Weill Cornell Medical Center has completed the first-ever phase 1 clinical trial using gene therapy to battle Parkinson's disease.

The study of 11 men and one woman with the progressive neurodegenerative illness found that the procedure -- in which surgeons inject a harmless gene-bearing virus into the brain -- was both safe and resulted in improved motor function for Parkinson's patients over the course of one year. The findings are published in the June 23 issue of The Lancet.

These exciting results need to be validated in a larger trial, but we believe this is a milestone -- not only for the treatment of Parkinson's disease, but for the use of gene-based therapies against neurological conditions generally, says lead researcher Dr. Michael Kaplitt, associate professor of neurological surgery and the Victor and Tara Menezes Clinical Scholar in Neurological Surgery at Weill Cornell Medical College, and director of Movement Disorders Surgery at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

Dr. Kaplitt has devoted much of his academic research career to the development of effective gene therapy techniques against Parkinson's disease and other neurological disorders. In fact, 13 years ago, he and Dr. Matthew During pioneered a now widely used gene-delivery technique for the brain using an altered, harmless form of adeno-associated virus (AAV). In 2003, Dr. Kaplitt performed the world's first gene therapy surgery for Parkinson's, conducted at NewYork Presbyterian/Weill Cornell.

Viruses exist in nature mainly to transfer their own genes to the host cell, he explains. So, we modify the AAV in such a way that the only gene it carries is the one we want to deliver to the therapeutic site.

In this case, the gene of interest is the glutamic acid decarboxylase (GAD) gene. GAD makes a chemical called GABA, a major inhibitory neurotransmitter in the brain that helps 'quiet' excessive neuronal firing, explains Dr. During, the senior author of the current study, who worked on this research while at Weill Cornell. Dr. During is now professor of molecular biology and cancer genetics at Ohio State University.

In Parkinson's disease, not only do patients lose many dopamine-producing brain cells, but they also develop substantial reductions in the activity and amount of GABA in their brains. This causes a dysfunction in brain circuitry responsible for coordinating movement, Dr. During explains.

The researchers' bold idea: to insert the GABA-producing gene GAD back into an area of the brain called the subthalamic nucleus, a key regulatory center within this motor circuit.

Our hope was that with a single operation to this single site, we could boost GABA production and thereby normalize the function of the entire circuit, Dr. Kaplitt says. Not only would this alter the chemical balance in the subthalamic nucleus; it should also provide GABA to other parts of the network that weren't getting enough of the neurotransmitter.

To test that theory, the investigators injected the GAD-bearing AAV vector into the subthalamic nucleus of each of the 12 Parkinson's patients, but only on one side of their brains.

Because this was the first such study of its kind, we targeted just one side of the brain initially out of concerns for the patients' safety, Dr. During says. However, since the patients were symptomatic on both sides of the brain, this also provided an untreated side for comparison with the treated hemisphere.

The researchers then used a standard assessment of motor function, the Unified Parkinson's Disease Rating Scale (UPDRS) to track changes in patients' symptoms over the next 12 months. They also tracked changes in each patient's brain activity using positron emission tomography (PET) scans. These were both performed by the other two principal authors of the study, Drs. Andrew Feigin and David Eidelberg of North Shore-Long Island Jewish Health System.

Like all phase 1 studies, this one was primarily focused on gauging the safety of the technique, Dr. Kaplitt says. And on that count it succeeded brilliantly: We saw no adverse events related to the treatment, no immunological changes or infections over the year of the study, no imaging evidence of toxicity whatsoever.

The results in terms of clinical and neurological efficacy were also encouraging.

In terms of the UPDRS scores measuring motor function, we observed significant improvements in the 'off-state' phase -- meaning that period when Parkinson's patients have been off their medicines for 12 hours -- and also in the on-medication phase, when they were taking their drugs, Dr. Kaplitt says.

For example, at three months post-treatment, the patients as a group had already charted between a 25- and 30-percent improvement in off-state UPDRS scores, and those improvements persisted over the full year of the study. Similar results were seen in the on-medication state, the researchers found. Several individual patients showed impressive improvements of between 40 percent and 65 percent.

That was really surprising and heartening, because traditional Parkinson's surgeries improve patients in the off-state but not as frequently in the on-medication state, Dr. Kaplitt says.

Interestingly, these improvements in motor function were due to the side of the body controlled by the brain hemisphere that had received the treatment, Dr. During notes. Also, AAV tends to require several weeks to maximize and stabilize production of a therapeutic gene, and in fact we did not see significant clinical changes until more than 1 month after surgery. These both further suggest that it was the gene therapy that was driving their improvement.

There were also strong trends toward reductions in medication-linked dyskinesia (movement difficulties) and improved activities of daily living, although neither of these trends reached statistical significance.

Finally, PET scans revealed a more normal level of activity up to 1 year following surgery in exactly those areas of the brain that the researchers had been hoping to fix. Again, this improvement occurred only in that half of the brain that had received the GAD gene, Dr. Eidelberg says.

Will these remarkable improvements persist Only longer follow-up can tell, but prior studies in animals, including primates, suggest that the transplanted gene does stay active for years, Dr. Kaplitt says.

Our next step of course is to move towards a larger, more definitive efficacy-centered study, he notes.

We believe that this breakthrough trial has implications that go far beyond Parkinson's research, Dr. Kaplitt adds. It's taken us nearly two decades of hard work to get here, but the success of this trial lays the foundation for the use of gene therapy against neurological diseases generally. We've now shown that the genetic modification of the patient's own brain cells can be done safely, and it appears to have enough effectiveness in this case to justify further exploration -- potentially opening up gene therapy for a host of brain disorders.

Mother mice more attuned to pup sounds than others

Mon, 11 Jun 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Researchers have shown for the first time that the behavioral context in which communication sounds are heard affects the brain's ability to detect, discriminate and ultimately respond to them. Specifically, the researchers found that the auditory neurons of female mice that had given birth were better at detecting and discriminating vocalizations from mouse pups than the auditory neurons in virgin females.

ÒAlthough there have been many studies on communication and neurons in animals, such as in primates, birds and bats, those studies have focused on how neurons respond to sounds that were already behaviorally relevant to the animals, says Robert Liu, PhD, Emory University assistant professor of biology and lead author of the study, which appears in the June 12, 2007 issue of PLoS Biology.

What's different about this study is that we used natural vocalizationsÑa range of pup callsÑto see how well neurons in mother mice and virgin, or pup-nave mice, detect, discriminate and act on this behaviorally important sound,Ó says Dr. Liu. Ultrasonic calls emitted by mouse pups communicate distress and elicit a search and retrieval response from mothers.

Our current work demonstrates that the neural code for communication sounds in adult mammals can change, either because of experience or because of hormonal mechanisms, as the significance of the signal is acquired. This means that the brain can improve information processing for specific communicative functions, says Liu.

Liu began the work as a postdoctoral fellow in the lab of senior author Christoph Schreiner, PhD, MD, professor and vice chair of otolaryngology, head and neck surgery and a member of the W.M. Keck Foundation Center for Integrative Neuroscience at the University of California, San Francisco.

In the study, the researchers determined that the neurons in the mothers' auditory cortex, an area of the brain that processes sounds, showed larger and earlier electrical spiking, or signaling, than in virgin mice, says Dr. Schreiner.

This shows, says Dr. Liu, that, the timing plays an important role in the neural code of sounds. The idea that spike timing is important in brain processes has been around for a long time, but we're looking at it specifically in the context of natural communication. And we found that the big difference in encoding is the behavioral relevance of these sounds.

Although the pups' vocalizations vary quite a bit, Dr. Liu says the mothers can still detect the calls, understand them and take action. What is really intriguing is that behavioral studies have shown that, if you look at vocalizations made by male adult mice, they also make very high-frequency vocalizations as do pups but the mothers don't react to them as they do to the pup calls, says Dr. Liu.

Along these lines, another behavioral study, reported by a team in Germany in 1987, revealed behavioral differences in mice in response to vocalizations. In this case, says Schreiner, there were two groups of mice: the pup-nave mice and the mother mice who really care about these sounds. The researchers found that, If you play these vocalizations, the mothers run over to get the pup. If it's a different sound, they don't go as often, and why should they? Likewise, the female mice who have not been mothers don't go to the source of the pup calls more often than to any other vocalization. They're the same age and same species, yet only one thing is different: one group has had pups and the other hasn't. It appears that a switch is thrown that improves sensitivity to these sounds in the mothers.Ó

Dr. Schreiner says further research is needed to determine whether mothers recognize pup sounds immediately after they become pregnant, meaning a hormonal switch has been thrown, or after they give birth. Recognition of pup cries after birth would indicate that exposure to the cries triggers mothers' attentiveness.

Dr. Schreiner likens the improved ability of mother mice to distinguish sounds to what adult humans experience when initially learning a foreign language. ÒWe go to a foreign country, hear what people are saying, but we can't make subtle discriminations of syllables in order to establish the border between words. With time and experience the brain is adjusting to this, our neurons are becoming more discriminative, and we can distinguish words in what initially just appeared to us as an unbroken stream of sound.Ó

According to the authors, this study helps demonstrate how important sounds are encoded in the normal brain but also has implications for developing therapeutic strategies in children and adults who suffer from speech-perception deficits.

Bird song study gives clues to human stuttering

Mon, 11 Jun 2007 04:00:00 PST

( from http://www.rxpgnews.com ) HOUSTON and NEW YORK -- Researchers at the Methodist Neurological Institute (NI) in Houston and Weill Cornell Medical College in New York City used functional MRI to determine that songbirds have a pronounced right-brain response to the sound of songs, establishing a foundational study for future research on songbird models of speech disorders such as stuttering, as reported today in Proceedings of the National Academy of Sciences U.S.A.

This is the first functional MRI study to determine how vocal sounds are represented within the brain of an awake zebra finch, a well-studied animal model of vocal learning. Because of many similarities between birdsong and human speech, this research could lead to a better understanding of the cause of stuttering and other speech problems.

By using specifically-tailored high-resolution fMRI in awake, mildly sedated zebra finches, scientists were able to look at the activity in the entire avian brain during song stimulation.

While we found that both sides of the brain were activated by sounds in the songbirds, our research showed that the right side of their brains discriminated sounds better, said Santosh A. Helekar, M.D., Ph.D., lead author of the paper. Helekar is associate research professor of neuroscience at the Methodist NI and Weill Cornell. If we can link what we find in birds to what we already know about human brains, then we could better understand the causes of speech disorders and, in the long-run, be able to provide treatments to patients.

Helekar has long collaborated with Dr. David Rosenfield, director of the speech and language center at the Methodist NI and a nationally-renowned language expert, to study stuttering and other speech disorders.

Using the blood oxygenation level-dependent (BOLD) fMRI method, researchers observed brain response patterns in 16 adult zebra finches during playback of the birds' own song, their tutor's song, an unfamiliar zebra finch's song, and a synthetic sound of a single frequency. The songbirds' own song caused a stronger response in the auditory areas of the brain. The overall findings suggest that vocal sounds may be better represented on the right side of the brain in these songbirds.

We don't know exactly what goes wrong with the human brain when a patient stutters or has a particular speech problem. But, if we can understand the neurobiology of the brain of this animal model and how sounds are processed by birds that produce normal and variant songs, then we may be able to translate these findings into treatments for patients with disorders such as stuttering and verbal dyspraxia, said Henning U. Voss, Ph.D., first author on the PNAS paper and assistant professor of physics in radiology at Citigroup Biomedical Imaging Center of Weill Cornell Medical College.

The vocal learning process in the zebra finch offers a model system to study the neural and behavioral mechanisms by which humans learn to produce sounds. Songbirds such as zebra finches have specialized areas of their brains devoted to communication. That is why they have been used as animal models to study speech disorders, such as stuttering. It is estimated that more than 3 million Americans stutter.

A wider range of sounds for the deaf

Fri, 08 Jun 2007 04:00:00 PST

( from http://www.rxpgnews.com ) ANN ARBOR, Mich. -- More than three decades ago, scientists pursued the then-radical idea of implanting tiny electronic hearing devices in the inner ear to help profoundly deaf people. An even bolder alternative that promised superior results implanting a device directly in the auditory nerve was set aside as too difficult, given the technology of the day.

Now, however, scientists have shown in animals that its possible to implant a tiny, ultra-thin electrode array in the auditory nerve that can successfully transmit a wide range of sounds to the brain. The studies took place at the University of Michigan Kresge Hearing Research Institute.

If the idea pans out in further animal and human studies, profoundly and severely deaf people would have another option that could allow them to hear low-pitched sounds common in speech, converse in a noisy room, identify high and low voices, and appreciate music areas where cochlea implants, though a boon, have significant limitations.

In nearly every measure, these work better than cochlear implants, says U-M researcher John C. Middlebrooks. He led a study requested by the National Institutes of Health to re-evaluate the potential of auditory nerve implants. Middlebrooks is a U-M Medical School professor of otolaryngology and biomedical engineering. He collaborated with Russell L. Snyder of the University of California, San Francisco and Utah State University. The two co-authored an article on the results in the June issue of Journal of the Association for Research in Otolaryngology.

The possible auditory nerve implants likely would be suitable for the same people who are candidates today for cochlear implants: the profoundly deaf, who cant hear at all, and the severely deaf, whose hearing ability is greatly reduced. Also, the animal studies suggest that implantation of the devices has little impact on normal hearing, offering the possibility of restoring sensitivity to high frequencies while preserving remaining low-frequency hearing.

Middlebrooks says its possible that the low power requirements of the auditory nerve implants might lead to development of totally implantable devices. That would be an improvement over the external speech processor and battery pack cochlear implant users need to wear and often have to recharge daily.

If the initial success in animals is borne out in further tests, a human auditory nerve implant is probably five to 10 years away, he says.

The researchers used cats bred for laboratory use in their experiments. They measured brain processing of auditory signals in normal conditions, then compared deaf animals brain responses to sounds using cochlear implants and then the direct auditory nerve implants. These measurements employed neuron -monitoring technology developed earlier at U-M. The scientists found their sensitive 16-electrode microarray resulted in several advantages over cochlear implants.

Approved by the Food and Drug Administration in 1984, cochlear implants have greatly benefited profoundly and severely deaf people. More than 100,000 implants have been performed worldwide in the last two decades, including more than 1,000 at U-M.

Like the new device, cochlear implants are small electrode arrays that receive signals from an external sound processor... They are designed to stimulate the auditory nerve and other cells to produce a sensation of hearing. But their location, separated from auditory nerve fibers by fluid and a bony wall, is a limitation.

Access to specific nerve fibers is blunted, Middlebrooks says. The effect is rather like talking to someone through a closed door.

With the new intraneural stimulation procedure, that effect is eliminated, and there are other technical advantages, too. The intimate contact of the array with the nerve fibers achieves more precise activation of fibers signaling specific frequencies, reduced electrical current requirements and dramatically reduced interference among electrodes when they are stimulated simultaneously, Middlebrooks says.

Middlebrooks has talked with U-M surgeons in otolaryngology about surgical approaches in humans, and is working with U-M biomedical engineers on an intraneural device that can remain in place and be tested further in animals over the next two years. The devices need to be studied over time to see if they are safely tolerated by the auditory nerve.

If our work continues to go very well, we might begin human trials in no less than five years, Middlebrooks says.

Such a device might be used first in people whose cochleas are filled with bone and therefore arent eligible for a cochlear implant, or people whose cochlear implants are no longer effective.

The University of Michigan has submitted a patent application for the procedure. Through its Office of Technology Transfer, it is seeking a commercialization partner to assist in bringing the technology to market.

Some children are born with 'temporary deafness' and do not require cochlear implant

Wed, 16 May 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Clinical research conducted in the Department of Communication Disorders at the University of Haifa revealed that some children who are born deaf recover from their deafness and do not require surgical intervention. To date, most babies who are born deaf are referred for a cochlear implant. Many parents will say to me: 'My child hears; if I call him, he responds'. Nobody listens to them because diagnostic medical equipment did not register any hearing. It seems that these parents are smarter than our equipment, said Prof. Joseph Attias, a neurophysiologist and audiologist in the Department of Communication Disorders at the University of Haifa, who made the discovery.

There are two causes of congenital deafness among children. One is the lack of hair cells, receptors in the inner ear that convert sounds into pulse signals that activate the auditory nerve. The second cause is a malfunction of the nerves. A child may be born with what appears to be a normal inner ear, but the hair cells do not communicate with the auditory nerves and the child cannot hear. To date, doctors have recommended the same treatment for all children born deaf. Once a child has been diagnosed as deaf, doctors recommend a cochlear implant, a surgically- implanted electronic device that bypasses the hair cells and directly stimulates the auditory nerve. Prof. Attias stresses that a cochlear implant is an excellent treatment for children with congenital deafness whose hearing does not improve over time. However, it appears that some children are born with temporary deafness a condition previously unidentified.

This discovery, like other revolutionary discoveries, was made by chance. A child who was born with malfunctioning hair cells and was scheduled for a cochlear implant was referred to Prof. Attias for a pre-surgical evaluation. The evaluation found that the child's brain and auditory nerves exhibited beginning responses to sound stimuli. The surgery was postponed. Follow-up visits showed increasing function of the hair cells and eventually the child reached a state of normal hearing. Prof. Attias, who is part of a cochlear implant team at Schneider Children's Medical Center, looked in the department archives and found other, similar cases. Because these children go through a series of tests and evaluations by different doctors, a process that often takes months, there are cases of children who were initially referred for the procedure who didn't have it done. Sometimes parents decide not to do the surgery; sometimes they do it elsewhere. I called parents and found another seven cases of children who were diagnosed as deaf, did not have the procedure done, and began to hear, said Prof. Attias.

Prof. Attias then found another five children who had been referred to him for pre-operative testing who had begun to hear. At the end of his clinical research, he identified a window of opportunity of 17 months during which deaf children may begin to hear. A child whose deafness is caused by a malfunctioning connection between hair cells and the auditory nerve should not have a cochlear implant in the first 17 months of life. Research results show the possibility that at least some of these children undergo the procedure for nothing, explained Prof. Attias.

He added that some of the children only develop partial hearing, which can be augmented with external hearing aids. Prof. Attias is now researching temporary deafness among young children, looking to find a way to identify those who will recover and those who will not.

Study shows isolation of stem cells may lead to a treatment for hearing loss

Thu, 05 Apr 2007 04:00:00 PST

( from http://www.rxpgnews.com ) CLEVELAND, OH -- Have you ever walked by someone listening to their i-Pod loud enough for you recognize the song? Studies have shown noise-induced hearing loss is going to become the next big epidemic affecting our younger generation though the effects wont show until it is too late to treat. In addition to loud noise, certain cancer drugs or genetic factors can cause hearing loss in humans due to loss or faulty development of the sensory microphones (hair cells) inside the ear the cochlea. Lost hair cells are not replaced and people exposed to these conditions face permanent hearing loss. Identification of the stem cells from the adult cochlea would be a major step forward to develop new therapeutic approaches to hearing loss.

Members of the National Center for Regenerative Medicine research team, Dr. Robert Miller and Dr. Kumar Alagramam, both of Case Western Reserve University School of Medicine, recently published research findings in Developmental Neuroscience which suggest new ways of treating hearing loss. These researchers have isolated cochlear stem cells located in the inner ear and already primed for development into ear-related tissue due to their proximity to the ear and expression of certain genes necessary for the development of hearing. Previous work in our lab with young-adult mouse cochlear tissue showed expression of genes normally found in stem cells and neural progenitors. This led us to hypothesize that cochlea harbors stem cells and neural precursor cells. Our work in collaboration with Millers lab supports our hypothesis Dr. Alagramam said. They say that in early life, these precursor cells may be able to regenerate hair cells, but their capacity to do so becomes limited as the ear develops and ages. The team's research is a major step in devising a therapy to reverse permanent hearing loss because it may lead to the activation of cochlear stem cells in the inner ear to regenerate new hair cells. Clearly we have miles to go before we reach our end goal, but the exciting part is now we can test compounds that could promote regeneration of hair cells from these precursor cells in vitro, we can study the genes expressed during the transition from stem cells to hair cells, and we can think of developing strategies for cell replacement, i.e. transplanting these cochlear stem cells into the adult cochlea to affect hair cell replacement in the mouse, by extension, in humans remarked Dr. Alagramam.

In this paper, Drs. Miller and Alagramam offer further evidence for the existence of cochlear stem cells in the mouse cochlea by confirming the ability to form stem cell spheres in culture and by characterizing these cells in terms of neural and hair cell development using a panel of stem cell development and hair cell markers. The formation of spheres from early postnatal cochlear tissues and their expression of a wide range of developmental markers unique to hair cells confirm the possibility that self-supporting hair cell precursors exist in or can be derived from the postnatal mammalian cochlea.

Currently there are no clinical treatments to repair these hair cells vital to normal hearing. In the United States, 30% of people over the age of 65 have a handicapping hearing loss and of those, one in 500 people become deaf before reaching adulthood. In most cases, the target is the highly specialized hair cells. Docked inside the spiral duct of the human cochlea are ~15,000 hair cells, which are highly specialized neuroepithelial cells that enable us to hear a violin or a whisper. These hair cells differ in length by minuscule amounts and are set in motion by specific frequencies of sound. We hear this sound because this motion induces the hair cell to release an electrical impulse which passes along the auditory nerve to the brain. If the sound is too loud, the hair cells are damaged and no longer send signals to the brain. Severely damaged hair cells do not repair themselves nor do they regenerate naturally.

While further research is necessary, the researchers believe these precursor cells have the potential to regenerate the damaged hair cells and restore normal hearing. The team has already begun animal studies to explore the use of cochlear stem cells in well-established hair cell ablation models and in deaf mouse mutants with predictable patterns of early hair cell loss. This line of research will evaluate the in vivo survival and differentiation of self-renewing cochlear cell populations and potentially lead to new therapies for the numerous individuals that are going to suffer from noise-induced hearing loss in the near future.

One membrane, many frequencies

Tue, 27 Mar 2007 04:00:00 PST

( from http://www.rxpgnews.com ) Modern hearing aids, though quite sophisticated, still do not faithfully reproduce sound as hearing people perceive it. New findings at the Weizmann Institute of Science shed light on a crucial mechanism for discerning different sound frequencies and thus may have implications for the design of better hearing aids.

Research by Dr. Itay Rousso of the Weizmann Institutes Structural Biology Department, which recently appeared in the Proceedings of the National Academy of Sciences (PNAS), suggests that a thin structure in the inner ear called the tectorial membrane responds to different frequencies. This membrane communicates between the outer hair cells (which amplify sound in the form of mechanical vibrations) and the inner hair cells (which convert these mechanical vibrations to electrical signals and pass them on to the brain via the auditory nerve). If certain genes for this membrane are missing or damaged, total deafness ensues.

Rousso and research student Rachel Gueta, together with researchers at the Ben-Gurion University of the Negev, wanted to explore the mechanical properties of the tectorial membrane. Using an atomic force microscope, which probes surfaces with a fine microscopic needle, they tested the resistance of the gel-like membrane at various points to assess precisely how rigid or flexible it was. To their surprise, the scientists found that the level of rigidity varies significantly along the length of the membrane: One end of the membrane can be up to ten times more rigid than the other.

These differences occur in the part of the membrane that is in direct contact with the outer hair cells. Observation under a scanning electron microscope revealed that this variation is due to changes in the way the protein fibers are arranged: At one end, they form a flimsy, net-like structure that allows the membrane to be flexible; on the rigid side, the fibers are densely and uniformly packed.

The more rigid a tectorial membrane is, the higher the frequency at which it can vibrate. Thus, the flexible end of the membrane, which should respond to low-frequency vibration, is found near the hair cells that transmit low frequencies, and the rigid end near hair cells that transmit high ones. This spatial separation, say the scientists, translates into the ability to distinguish between sounds of different frequencies.

The new understanding of the mechanics of hearing may assist in the development of better hearing aids. Rousso, meanwhile, plans to continue exploring how variations in membrane rigidity affect hearing. He intends to test tectorial membranes under different physiological conditions to further understand how we hear such a wide range of frequencies (the highest is a thousand times the lowest), as well as to shed light on the causes of certain hearing problems.

Anti-epileptics can prevent permanent hearing loss, study reports

Wed, 14 Mar 2007 08:31:28 PST

( from http://www.rxpgnews.com ) On the battlefield, a soldier's hearing can be permanently damaged in an instant by the boom of an explosion, and thousands of soldiers returning from Iraq have some permanent hearing loss. But what if soldiers could take a pill before going on duty that would prevent damage to hearing?

Research at Washington University School of Medicine in St. Louis suggests a medicinal form of hearing protection may someday be a possibility. A group headed by Jianxin Bao, Ph.D., research associate professor of otolaryngology and head of the Central Institute for the Deaf's Presbycusis and Aging Laboratory, has found that two anti-epileptic drugs can prevent permanent hearing loss to a significant degree in mice exposed to loud noises.

"The military has a tremendous need for preventing noise-induced hearing loss," Bao says. "But others would also benefit. For example, many hunters have hearing loss on the side where they hold their gun, and pilots are especially prone to hearing loss because of the noise in airplane cabins. Protective equipment or earplugs aren't always appropriate, and right now no drug on the market can prevent or treat noise-induced hearing loss."

Bao's laboratory is dedicated to the study of both age-related and noise-induced hearing loss. About 28 million Americans have a hearing impairment, and excessive noise is the predominant cause of permanent hearing loss. At least 30 million people in the United States encounter hazardous levels of noise at work, particularly in jobs such as construction, mining, agriculture, manufacturing, transportation and the military.

Bao and colleagues found that if they exposed mice to loud sounds and then gave them trimethadione (Tridione®) or ethosuximide (Zarontin®) anticonvulsive medications used to treat epilepsy they could prevent a significant amount of permanent hearing loss. When mice got the medications before noise exposure, only trimethadione, not ethosuximide, significantly reduced subsequent hearing loss. The results are reported in Hearing Research and are now available through advanced online publication.

Bao notes that other researchers are investigating agents such as antioxidants for their potential in preventing hearing loss, but the two anticonvulsive drugs his lab studied have had FDA approval and so could be used much sooner in clinical trials that study hearing loss.

The experiments in mice showed that the drugs could reduce by about five decibels the permanent threshold shift that can occur after noise exposure. For example, if the softest sound the mice could hear before the noise was 30 decibels, after the noise it might take a louder, 50-decibel sound for the untreated mice to hear but only 45 decibels for the treated mice. A decibel is a standard unit of sound, and normal conversation is around 60 decibels.

"In people, a five decibel difference in hearing ability can be important for everyday speech," Bao says. "We will continue our investigations of these kinds of drugs to see if we can improve the results. One possibility is to combine an anticonvulsant with an antioxidant to increase the protective effect."

Both drugs tested are T-type calcium channel blockers, which inhibit the movement of calcium ions into nerve cells. In the ear, calcium may play a role in causing damage to hair cells (specialized cells that sense sound vibrations) and the nerve cells that connect the hair cells to the hearing centers of the brain.

These anti-epileptic drugs can have unwanted side effects such as dizziness and sleepiness. "The drugs' side effects would be detrimental in certain situations," Bao says. "But lowering the dosage and combining them with other drugs may be effective. Newer versions of anti-epilepsy drugs have fewer side effects, and it may be possible to modify the structure of the drugs so that they don't cross into the brain, which could avert some side effects."

Research finds music training 'tunes' human auditory system

Mon, 12 Mar 2007 04:00:00 PST

( from http://www.rxpgnews.com ) EVANSTON, Ill. -- A newly published study by Northwestern University researchers suggests that Mom was right when she insisted that you continue music lessons -- even after it was clear that a professional music career was not in your future.

The study, which will appear in the April issue of Nature Neuroscience, is the first to provide concrete evidence that playing a musical instrument significantly enhances the brainstems sensitivity to speech sounds. This finding has broad implications because it applies to sound encoding skills involved not only in music but also in language.

The findings indicate that experience with music at a young age in effect can fine-tune the brain's auditory system. Increasing music experience appears to benefit all children -- whether musically exceptional or not -- in a wide range of learning activities, says Nina Kraus, director of Northwestern's Auditory Neuroscience Laboratory and senior author of the study.

Our findings underscore the pervasive impact of musical training on neurological development. Yet music classes are often among the first to be cut when school budgets get tight. That's a mistake, says Kraus, Hugh Knowles Professor of Neurobiology and Physiology and professor of communication sciences and disorders.

Our study is the first to ask whether enhancing the sound environment -- in this case with musical training -- will positively affect the way an individual encodes sound even at a level as basic as the brainstem, says Patrick Wong, primary author of Musical Experience Shapes Human Brainstem Encoding of Linguistic Pitch Patterns. An old structure from an evolutionary standpoint, the brainstem once was thought to only play a passive role in auditory processing.

Using a novel experimental design, the researchers presented the Mandarin word mi to 20 adults as they watched a movie. Half had at least six years of musical instrument training starting before the age of 12. The other half had minimal (less than 2 years) or no musical training. All were native English speakers with no knowledge of Mandarin, a tone language.

In tone languages, a single word can differ in meaning depending on pitch patterns called tones. For example, the Mandarin word mi delivered in a level tone means to squint, in a rising tone means to bewilder, and in a dipping (falling then rising) tone means rice. English, on the other hand, only uses pitch to reflect intonation (as when rising pitch is used in questions).

As the subjects watched the movie, the researchers used electrophysiological methods to measure and graph the accuracy of their brainstem ability to track the three differently pitched mi sounds.

Even with their attention focused on the movie and though the sounds had no linguistic or musical meaning for them, we found our musically trained subjects were far better at tracking the three different tones than the non-musicians, says Wong, director of Northwesterns Speech Research Laboratory and assistant professor of communication sciences and disorders.

The research by co-authors Wong, Kraus, Erika Skoe, Nicole Russo and Tasha Dees represents a new way of defining the relationship between the brainstem -- a lower order brain structure thought to be unchangeable and uninvolved in complex processing -- and the neocortex, a higher order brain structure associated with music, language and other complex processing.

These findings are in line with previous studies by Wong and his group suggesting that musical experience can improve ones ability to learn tone languages in adulthood and level of musical experience plays a role in the degree of activation in the auditory cortex. Wong also is a faculty member in Northwesterns Interdepartmental Neuroscience Program.

The findings also are consistent with studies by Kraus and her research team that have revealed anomalies in brainstem sound encoding in some children with learning disabilities which can be improved by auditory training.

We've found that by playing music -- an action thought of as a function of the neocortex -- a person may actually be tuning the brainstem, says Kraus. This suggests that the relationship between the brainstem and neocortex is a dynamic and reciprocal one and tells us that our basic sensory circuitry is more malleable than we previously thought.

Overall, the findings assist in unfolding new lines of inquiry. The researchers now are looking to find ways to train the brain to better encode sound work that potentially has far-reaching educational and clinical implications. The study was supported by Northwestern University, grants from the National Institutes of Health and a grant from the National Science Foundation.

RIT researchers developing 'micropump' for hearing-loss treatments

Mon, 12 Feb 2007 05:00:00 PST

( from http://www.rxpgnews.com ) Hearing aids have existed, in one form or another, for hundreds of years. Wearable, electrical hearing aids have been around for about 75 years. More recentlyover the past 50 yearscochlear implants have been used to create or restore hearing for some of the estimated 30 million people in modern societies affected by permanent hearing loss and deafness (including many age 65 and older).

The older technologies produce similar outcomes: Amplifying and filtering sound to enhance hearing. Are there better ways to improve hearing?

Researchers at Rochester Institute of Technology aim to surpass the inherent limitations of hearing aids and cochlear implants through the development of a micropump for administering drugs and gene-based therapy treatments. The goal: improved treatment and curing of auditory dysfunction.

The project is supported by a $922,048 award from the National Institutes of HealthNational Institute on Deafness and Other Communication Disorders.

Pioneering studies in the areas of auditory gene therapy and chemotherapy have produced exciting results showing potential for protection and regeneration of sensory systems in the inner ear, explains David Borkholder, the project's principal investigator and an assistant professor of electrical engineering in RIT's Kate Gleason College of Engineering. More elaborate treatments are needed to achieve full restoration of hearing in animal models and for translational results in human clinical trials.

Borkholder is collaborating with the University of Rochester Medical Center to develop an implantable, refillable, variable-flow micropump platform for intracochlear drug delivery for deafness therapy research. Initially, a device will be designed for and tested using mice.

This micropump will enable chronic, calibrated delivery of multiple therapeutic agents that is not possible with existing pump technologies explains Borkholder, an expert in biomedical engineering and micoelectromechanical systems.

The project is expected to provide a detailed understanding of acceptable dose and timing profiles for intracochlear drug delivery in mice without detriment to cochlear function. The technology is scaleable to use in humans and may be particularly useful in pediatrics.

Robert D. Frisina, a professor and associate chair of otolaryngology and professor of biomedical engineering and neurobiology and anatomy at the University of Rochester Medical Center, is serving as research mentor. Frisina is also distinguished researcher in biological sciences in RIT's College of Science and professor of communication sciences and associate director of the International Center for Hearing and Speech Research at the National Technical Institute for the Deaf at RIT.

Although some people are helped with hearing aids, the majority of those with hearing loss or hearing-related balance disorders go untreated, Frisina says. Future biomedical interventions will be aimed at treating the underlying biological problems that cause permanent sensorineural hearing loss rather than trying to amplify and filter incoming sounds with hearing aids.

A critical step for implementing research aimed at repairing or restoring nerve cells that are damaged or missing in the inner ear is to develop more precise, calibrated micropumps for delivering chemotherapeutic, gene-therapy or stem-cell therapeutic agents, first for animal research, then for clinical trials. This project is a critical step forward in developing microfabricated pumps. Longer-term goals include developing and testing inner ear micropumps for clinical applications to treat human inner-ear hearing and balance problems.

Surprising airbag hazards among research findings at hearing safety conference

Thu, 08 Feb 2007 05:00:00 PST

( from http://www.rxpgnews.com ) At the National Hearing Conservation Associations 32nd annual conference, top experts in the field will reveal new findings related to automobile airbags, military hearing protection, and farm-work related trauma. Several hundred people are expected to attend the conference, titled A Passion to Preserve, which will be held Feb. 15-17 at the Hyatt Regency in Savannah, Ga.

Permanent hearing loss is the third most common chronic health condition in people over the age of 65, and roughly 30 million people in the United States have significant permanent hearing loss.

The extent of the problem in society is much greater than people realize, said NHCA Director of Education Brian Fligor. It deserves so much of our time, attention and resources because so much of it is preventable, and it has such a profound effect on our quality of life, productivity, and general well being.

The conference will host dozens of presentations, including auditory physiologist Dr. G. Richard Prices Intense Impulse Noise: Hearing Conservations Poison Gas, which has surprising new data on hearing loss as a result of automobile airbag deployment. He will present data predicting that 17 percent of people who are exposed to car airbag deployment in the United States will suffer some permanent hearing loss. Price will also describe research that concludes, counterintuitively, that having car windows rolled up when airbags are deployed is actually less hazardous to the ear than rolled-down windows. Previously experts thought rolled-up windows were more dangerous because they allow for higher pressure to be created inside the cabin.

Dr. Nancy Sprince, of the University of Iowa College of Public Health, will be presenting Hearing Loss: A Risk Factor for Farm-Work Related Traumatic Injury, in which she will discuss a new study showing that hearing difficulties increase farmers risk of work-related traumatic injuries. She will advocate the prevention of agricultural injuries by controlling the noise exposure that leads to hearing loss.

A luncheon presented by Dr. Charles D. Ross of Longwood University will discuss how acoustical phenomena affected the outcomes of Civil War battles. He will explain how acoustic shadows, a catch-all term that encompasses several types of phenomena, can make a person not hear a sound he or she would ordinarily hear or make a person hear a sound he or she would not ordinarily hear. Also among the presentations will be an Army study assessing an improved version of the combat arms earplug. Previous concerns over the plugs fit, comfort and size have been improved, and the plug has been evaluated for performance in a number of different functions.

Pittsburgh ear study finds that fluid in the ear does not impair development in children

Fri, 19 Jan 2007 05:00:00 PST

( from http://www.rxpgnews.com ) Early insertion of ear tubes in otherwise healthy infants and young children with persistent fluid in the middle ear does not improve developmental outcomes up to 9 to 11 years of age, according to results of an important study at Children's Hospital of Pittsburgh of UPMC led by otitis media researcher Jack Paradise, MD.

These findings strongly suggest that no intervention is necessary for most children with fluid in their ears. Results of the study are published in the Jan. 18 issue of the New England Journal of Medicine.

Dr. Paradise and colleagues have conducted a longitudinal study of 6,350 children enrolled before the age of 2 months between 1991 and 1995. Among the group of those children who developed persistent middle ear fluid before age of 3 years, the researchers found no evidence that prompt insertion of ear tubes improves developmental outcomes compared with delayed insertion if the fluid eventually fails to clear up spontaneously. This finding reverses a decades-old belief held by many in the medical community that fluid in the middle ear may lead to developmental impairment.

These findings provide strong evidence that fluid persisting in the middle ear for periods as long as we studied does not affect developmental outcomes in children as old as 11 and that for otherwise healthy children with middle ear effusion, placement of ear tubes is ordinarily not necessary, said Dr. Paradise, a longtime pediatrician at Children's and professor emeritus of Pediatrics at the University of Pittsburgh School of Medicine.

Among children in the United States, otitis media is the most commonly diagnosed illness after the common cold. About 90 percent of children have at least one episode of otitis media by the time they are 3 years of age. The term otitis media refers both to ear infections and to fluid in the ear that follows ear infections or can lead to ear infections. Otitis media is inflammation in the lining of the middle ear cavity and usually occurs as a complication of a cold or other respiratory infection. The placement of ear tubes, because of either repeated infections, or persistent fluid or both, is the second most common surgery (next to circumcision) among children in the United States.

About 75 percent of children have at least one episode of otitis media by the time they are 3 years of age. Nearly half of these children have three or more episodes by the time they are 3.

Previously published study results by Dr. Paradise, an internationally recognized as a pioneer in pediatric primary care research, and colleagues also showed that prompt insertion of ear tubes in children with middle ear effusion also did not improve developmental outcomes at age 6 or at ages 3 and 4.

Previous studies by other investigators reported had warned that hearing loss associated with persistent otitis media in young children might result in long-term impairment of their development.

Because of this, official guidelines were developed recommending that young children with middle ear effusion lasting for as long as three or four months undergo insertion of ear tubes to clear the fluid and return the hearing to normal.

However, these previous studies, because of their design, established no cause-and-effect relationship between otitis media and developmental impairments, according to Dr. Paradise.

His cumulative findings played an important role in the 2004 decision by the American Academy of Pediatrics, the American Academy of Family Physicians and the American Academy of OtolaryngologyHead and Neck Surgery to revise these guidelines for the insertion of ear tubes.

Before 3 years of age, 429 children in Children's ear study with persistent effusion were randomly assigned to undergo ear tube insertion either promptly or up to nine months later if effusion persisted. Researchers assessed literacy, attention, social skills and academic achievement in 391 of these children at 9 to 11 years of age in the most recent component of the study.

At the time of testing, 84 percent of the children in the early-treatment group and 45 percent of the children in the delayed-treatment group had undergone insertion of ear tubes. There were no significant differences between the two groups in 48 different developmental measures.

These findings, coupled with the relatively minor risk associated with ear tube surgery, provide clear support for conservative management of fluid in the middle ear, as the fluid almost always clears up spontaneously, according to Dr. Paradise.

Our recommended treatment approach for children under age 3 in whom fluid has persisted for three months in both ears or four to five months in one ear now calls for watchful waiting for at least six additional months when fluid is present in both ears and for at least nine additional months when fluid is present in only one ear, he said.

His contributions have advanced pediatric medicine worldwide in the diagnosis and treatment of common childhood diseases, most notably diseases and disorders of the ears, tonsils and adenoids. His primary areas of research have involved investigation of indications for tonsillectomy and adenoidectomy and the management of middle-ear disease. His studies of these conditions have gained him international recognition.

Among his studies of otitis media, Dr. Paradise discovered the near universality of the disease in infants and young children with cleft palate. He also helped establish the use of tympanometry, a noninvasive test to determine the presence or absence of middle-ear abnormalities. Tympanometry has since become a standard diagnostic procedure in primary care pediatrics and an important tool in clinical studies of otitis media.

Call centre staff could face hearing damage risk

Sun, 19 Nov 2006 17:37:13 PST

( from http://www.rxpgnews.com ) London, Nov 19 (IANS) People working at call centres could suffer hearing damage from acoustic shock, say health experts.

Acoustic shocks are temporary or permanent disturbances of the functioning of the ear or of the nervous system, which may be caused to the user of a telephone or earphone by a sudden sharp rise in the acoustic pressure produced by it.

The sound could be a whistle, a bleep or any unexpected noise. Two thirds of call centres in Britain fail to protect their workers against hearing damage from noise, reported the online edition of BBC News.

A group of experts from The National Health Service (NHS) in Britain have formed an Acoustic Safety Programme, aimed at making call centre managers aware of the problem.

There are many people who have experienced acoustic shock but do not realise it, according to the experts. They warn that while some organisations are acting to safeguard the hearing of their staff, the vast majority are not.

Call centres can introduce equipment such as headphones that extract any potential cause of acoustic shock to protect the worker's hearing.

There should also be measures that will raise awareness about the problem, the experts added.

'It (acoustic shock) can be a debilitating occurrence for a call centre worker. They can develop permanent damage to their hearing,' said Chris Atwell, operations director for the Acoustic Safety Programme.

Added Mark Downs of the Royal National Institute for the Deaf: 'Acoustic shock is not the same as noise-induced hearing loss and is believed to occur at sound pressure levels below those which present an immediate risk to hearing damage.'

Critical hearing gene helps send auditory messages to brain

Thu, 19 Oct 2006 04:00:00 PST

( from http://www.rxpgnews.com ) By studying a gene earlier linked to deafness in humans, researchers now have new insight into the molecular process by which components of the inner ear send messages to the brain. The team reports its findings in the October 20, 2006, issue of the journal Cell, published by Cell Press.

The researchers found that mice lacking the gene otoferlin are profoundly deaf. The animals' deafness results from an inability to translate sound stimulation into the release of a chemical nerve messenger, or neurotransmitter, that would usually pass that information to auditory nerves and on to the brain, they reported. The sensory structures within the mutant animals' ears otherwise appeared to develop normally.

Study of the genes responsible for deafness can bring new insight into the molecular basis of how hearing works, said Christine Petit of the Institut Pasteur in Paris, France.

The sensory machinery within the inner ear is particularly intriguing, she added, in the sense that it operates with extreme temporal precision.

In mammals, the hearing organ, or cochlea, is a snail-shaped structure of the inner ear that is filled with a watery fluid. When that liquid moves in response to sound vibrations, thousands of sensory hair cells are set into motion.

Those sensory receptors come in two types: inner and outer hair cells. Outer hair cells amplify sound within the cochlea, allowing for hearing sensitivity. In contrast, inner hair cells are the genuine sensory cells transmitting information on the temporal structure and intensity of sound to the central nervous system, Petit said.

While outer hair cell defects can lead to considerable hearing loss, she added, a loss of inner hair cell function results in total deafness as messages cannot get through.

Inner hair cells operate in a manner comparable to neurons, she said. When an inner hair cell is stimulated, channels open up allowing calcium to flow in. In turn, that influx of calcium leads small sacs full of neurotransmitter to fuse with the cell membrane, releasing their contents into the space, or synapse, between the sensory cells and auditory nerve endings.

That chemical release allows nerve messages to be passed from one neuron to another. In inner hair cells, those neurotransmitter-filled vesicles are held in place at the cell membrane by tethers known as ribbons.

The current study follows up a report by Petit's team several years ago that people with a recessive form of deafness harbor two abnormal copies of the otoferlin gene. They also had some evidence hinting that the gene might act as a calcium sensor with an important role in neurotransmitter release by the inner hair cells. For example, otoferlin resembles a calcium-sensing protein involved in release of chemicals by sensory neurons elsewhere in the body. Their current study provides additional evidence to confirm that notion.

They now report that otoferlin activity in the cochlea occurs only in the inner hair cells, where it concentrates in the ribbon-associated synaptic vesicles. They also found that the otoferlin protein binds calcium and interacts with other proteins known to play a role in neurotransmitter release.

To further examine the gene's role in a living animal, the researchers studied knockout mice completely lacking a functional otoferlin gene. When exposed to sounds of various frequencies, the mice showed no detectable activity in parts of the brain that normally process sound.

They further found that the profoundly deaf mice suffered a complete loss of neurotransmitter release from their inner hair cells, despite having an apparently normal ribbon synapse and calcium flow.

The findings led the researchers to conclude that otoferlin is essential for a late step of [neurotransmitter release] and may act as the major [calcium] sensor triggering membrane fusion at the inner hair cell ribbon synapse.

The findings also have therapeutic implications, as they suggest that people who are deaf as a result of defects in otoferlin will benefit from cochlear implants, the researchers said. Cochlear implants analyze sound messages and convert them into electrical signals, bypassing the cochlea to directly stimulate the auditory nerves.

That's good news, Petit said, since otoferlin-linked deafness is an auditory neuropathy, a class of hearing impairment for which the best course of treatment had remained uncertain.

Dartmouth researchers find a neural signature of bilingualism

Tue, 17 Oct 2006 04:00:00 PST

( from http://www.rxpgnews.com ) HANOVER, NH Dartmouth researchers have found areas in the brain that indicate bilingualism. The finding sheds new light on decades of debate about how the human brain's language centers may actually be enhanced when faced with two or more languages as opposed to only one. The study was presented at the Society for Neuroscience's annual meeting on October 14-18 in Atlanta, Ga.

The researchers used an optical imaging technology called Near Infrared Spectroscopy (or NIRS) as a new microscope into the human brain's higher cognitive capacities, and they are among the first to take advantage of this technology in this way. NIRS has been used in the detection of, for example, breast tumors and heart blood flow. The Dartmouth team used NIRS to measure changes in the brain's oxygen levels while people performed specific language and cognitive tasks.

Authors of the study are Mark Shalinsky, former post-doctoral fellow at Dartmouth now a research fellow at Massachusetts General Hospital; Ioulia Kovelman, formerly a Dartmouth graduate student currently a post-doctoral fellow at MIT; Melody Berens, currently a post-doctoral fellow at Dartmouth; and Laura-Ann Petitto, the study's senior scientific director, and professor and chair of the Department of Education at Dartmouth.

NIRS provides much the same information as functional magnetic resonance imaging or 'fMRI,' but has several advantages over fMRI, says Shalinsky, the study's electro-neurophysiologist who created the analysis programs to use NIRS technology in this new way. NIRS technology is quiet, small and portable. It's only about the size of a desktop computer. It's child friendly, and it tolerates a participant's body movements, which makes it ideal for studying language where participants move their mouths to speak.

The NIRS showed similar increased brain activity across all people--monolinguals and bilinguals--in the brain's classic left-hemisphere language regions when they were speaking in only one language (that is, in monolingual mode), involving the left Broca's area and left dorsolateral prefrontal cortex (DLPFC), which are brain areas key to language and verbal working memory, respectively.

When bilinguals were simultaneously processing each of their two languages and rapidly switching between them (that is, in bilingual mode), they showed an increase in brain activity in both the left and the right hemisphere Broca's area, with greater activation in the right equivalent of Broca's area and the right DLPFC. This finding emerged as the key indicator of the brain's bilingual signature.

The researchers examined 20 people ranging from 18 to 30 years old (average age was 21.1 years). Ten participants were monolingual (who spoke only English), and ten were bilingual (who spoke both English and Spanish from around birth). Language processing tasks were given to monolingual people speaking their one language while undergoing NIRS brain recordings. The monolingual speakers' behavioral and brain activity were then compared to the bilingual speakers' behavioral and brain activity while performing identical language processing tasks in monolingual mode (that is, in Spanish, and in English) or in bilingual mode (that is, when simultaneously processing and rapidly switching between their two languages). The Dartmouth team used the Hitachi ETG-4000 NIRS system.

For decades, people have wondered whether the brains of bilingual people are different from monolinguals. People also worry that the brains of bilingual children are somehow negatively impacted by early experience with two languages, explains Petitto, who also holds the John Wentworth Endowed Chair in the Social Sciences. The present findings are significant because they show that the brains of bilinguals and monolinguals are similar, and both process their individual languages in fundamentally similar ways. The one fascinating exception is that bilinguals appear to engage more of the neural landscape available for language processing than monolinguals, which is a very good thing.

The team proposes that bilingual language processing provides a new window into the extent of what nature's neural architecture for language processing could be, if only we used it. Petitto adds The irony is that we may find it is the monolingual that is not taking full advantage of the neural landscape for language and cognitive processing than nature could have potentially made available.

She says that this research advances the path for using NIRS brain imaging technology both to understand the neural underpinnings of all human language and especially to discover the secrets of the bilingual brain.

Vision and hearing loss often occur together in older age

Mon, 09 Oct 2006 04:00:00 PST

( from http://www.rxpgnews.com ) Older adults with vision loss may be more likely to also have hearing loss, and the opposite appears true as well, according to a report in the October issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

In 1994, 18 percent of U.S. adults older than 70 reported impaired vision, 33 percent reported hearing problems and 9 percent reported both, according to background information in the article. Because more adults are living longer and the number of older adults is increasing, the burden associated with such age-related sensory impairments may be increasing.

Ee-Munn Chia, M.B.B.S., University of Sydney, Australia, and colleagues examined the association between age-related hearing and vision loss in 1,911 adults who were part of the Blue Mountains Eye Study, which enrolled older adults from the Blue Mountains region west of Sydney. Five years after the original study, between 1997 and 1999, participants (then age 55 to 98, average age 69.8) underwent a medical interview along with vision and hearing examinations.

Among the participants, 178 (9.3 percent) had visual impairment (worse than 20/40 vision) without contacts or glasses and 56 (2.9 percent) had best-corrected visual impairment, meaning that their best vision while wearing glasses or contacts was worse than 20/40. In addition, 766 (40 percent) had hearing impairment, including 599 with mild impairment, 141 with moderate impairment and 26 with marked impairment. Hearing loss occurred in 116 patients (65.2 percent) of those who were visually impaired. For each additional line on the eye chart that an individual could not read, his or her odds of having hearing impairment increased by 18 percent if the reduction was in best-corrected vision or 13 percent in uncorrected vision. When the researchers looked specifically at the two most common causes of age-related vision impairment, cataracts and age-related macular degeneration, they found that both were independently associated with hearing loss.

It is possible that both vision and hearing loss are regular consequences of aging, which could explain why they often occur in the same individual. In addition, common risk factors could predispose older adults to both conditions. Each condition has been postulated to result from somewhat similar genetic, environmental and lifestyle factors, the authors write. Exposure to oxidative stress [when cells receive too much oxygen], cigarette smoking and atherosclerosis [hardening of the arteries] and its risk factors have been linked respectively to age-related macular degeneration, cataract and hearing loss. Another common risk factor for cataract and visual and hearing impairments is diabetes.

Irrespective of the cause of sensory impairment, these two impairments were found to have a cumulative effect on function and well-being, significantly affecting both physical and mental domains, they conclude. Further studies are needed to understand the relationship between visual and hearing impairments in older persons and to determine whether intervention to improve these impairments could delay biologic aging.

UK researcher identifies brain region responsible for spatial hearing

Fri, 06 Oct 2006 21:10:00 PST

( from http://www.rxpgnews.com ) A major science prize was today awarded to a researcher who is looking for the region of the brain that helps us to hear someone in a noisy place, such as a party or bar, and is responsible for "training" the brain to hear better in these situations.

Not being able to hear a person's voice in a noisy room and follow conversations is one of the most common problems for Britain's nine million people with a hearing impairment.

Deafness Research UK, the leading medical charity, has awarded the 2007 Pauline Ashley Prize to Sam Irving, a young researcher at the MRC Institute for Hearing Research in Nottingham.

The Pauline Ashley Prize, established in memory of the charity's founder, Lady Ashley of Stoke, is awarded annually to a talented young scientist near the beginning of their career and undertaking research into deafness, or a related condition such as tinnitus.

Most people with a hearing impairment have trouble picking out what someone is saying when they're in a noisy room. Parties or bars are some of the worst places because the level of background noise is high, and so scientists call this the "cocktail party effect".

To see what this was like, Irving wore an earplug in one ear for a week which gave him a one-sided hearing loss. He said: "It was hell - especially when I was in the pub with friends. The background hubbub of the bar seemed to be the same level as the people I was talking to so I could barely hear what they were saying and it took a huge effort of concentration to follow any conversation. During the week, I gave up and spent a lot of time at home on my own because it was so distressing and tiring to be with lots of people or in a noisy place."

Our ability to detect a particular sound in the middle of lots of noise relies on the fact that we have two ears, and each detects an individual sound at a slightly different time (a sound coming from the left will reach the left ear slightly faster than it reaches the right ear). This is known as binaural or "spatial" hearing because it helps us identify where a sound is coming from and to concentrate or focus our hearing on that particular sound.

But, if you have some form of hearing problem in at least one ear, this ability is disrupted and the brain struggles to tell one sound from another.

The key to understanding this ability lies in the brain. Scientists are currently trying to work out exactly what part of the brain is responsible and how it allows us to distinguish one sound from lots of noise. Early research has had some remarkable results.

Most mammals also have this ability and in 2006, scientists working in the Oxford Auditory Neuroscience Group found that spatial hearing in ferrets has the ability to bounce-back or adapt to a hearing loss over time. Their brains are being "trained" to cope with the hearing loss and distinguish sounds much better.

The Oxford study placed healthy ferrets in a "ring of sound" where a sound is played from one of 12 speakers placed in a circle around the ferret and their response is monitored to see if they can detect which speaker the sound is coming from. Ferrets with normal hearing are very good at this and have excellent spatial hearing.

The team then fitted each of the ferrets with a small earplug in one ear which blocks some of the sound and so mimics a hearing loss. They then got the ferrets to perform the same task twice a day for two weeks and made a startling discovery. At first, the ferrets' ability to identify where the sound was coming from was dramatically reduced (because their spatial hearing had been disrupted by the earplug) but after two weeks they regained their ability and by the end of the period were as good at detecting the location of the sounds as they were before being fitted with an earplug.

Something in their brain was changing or adapting to the new situation and they were learning to compensate for the hearing loss.

Irving said: "When we switch on a bright light our eyes detect the increase in light levels and the brain sends a message to the eye to tell it to contract the pupil and let in less light. This is a feedback system where the brain is getting information from the eye about its surroundings, processing that information, and sending messages back to the eye to help it cope with different situations. We think something very similar is happening with the ear in spatial hearing."

"The brain is constantly monitoring the sounds around us and so knows what normal sound levels it would expect. When we introduce an earplug, it can detect the reduction in sound being received and we think it is actively sending messages back to the ear telling it how to cope with the new hearing loss, perhaps by stimulating or increasing the signal which is being blocked. It's compensating for the problem in a really clever way."

Irving is trying to locate the place in the brain which is channeling these feedback messages back to the ear.

"We already have a likely candidate called the OCB, the Olivocochlear Bundle, which is a part of the brain that we know is a centre of feedback information being transmitted from the brain back to the ear. We're now trying to work out if the OCB is responsible for spatial hearing in ferrets."

The Pauline Ashley Prize will allow Irving to work with a team led by Professor Charles Liberman at the Eaton Peabody Lab at MIT/Harvard, leading experts on the OCB system. His study will compare the performance of ferrets which have had their OCB removed with normal ferrets in the "ring of sound".

At the same time, Irving is conducting a study with human subjects who have volunteered to wear an earplug for five days. These subjects will be tested in a similar ring of sound and their performance measured over time. Early results show that humans also have the same ability to train their brain to cope with the hearing loss and become better at the task the longer they're wearing the earplug.

Irving said: "Understanding how this system works is fairly basic science, but will be vital in the future for engineering new ways of helping people with hearing impairment cope with difficult situations. They could be helped by computer generated training programs which run like regular computer games, but can target weaknesses in listening skills. By incorporating training exercises much like those performed by the ferrets, they can lead to auditory learning and an improved ability to listen."

First evidence that musical training affects brain development in young children

Tue, 19 Sep 2006 04:00:00 PST

( from http://www.rxpgnews.com ) Researchers have found the first evidence that young children who take music lessons show different brain development and improved memory over the course of a year compared to children who do not receive musical training.

The findings, published today (20 September 2006) in the online edition of the journal Brain [1], show that not only do the brains of musically-trained children respond to music in a different way to those of the untrained children, but also that the training improves their memory as well. After one year the musically trained children performed better in a memory test that is correlated with general intelligence skills such as literacy, verbal memory, visiospatial processing, mathematics and IQ.

The Canadian-based researchers reached these conclusions after measuring changes in brain responses to sounds in children aged between four and six. Over the period of a year they took four measurements in two groups of children those taking Suzuki music lessons and those taking no musical training outside school and found developmental changes over periods as short as four months. While previous studies have shown that older children given music lessons had greater improvements in IQ scores than children given drama lessons, this is the first study to identify these effects in brain-based measurements in young children.

Dr Laurel Trainor, Professor of Psychology, Neuroscience and Behaviour at McMaster University and Director of the McMaster Institute for Music and the Mind, said: This is the first study to show that brain responses in young, musically trained and untrained children change differently over the course of a year. These changes are likely to be related to the cognitive benefit that is seen with musical training. Prof Trainor led the study with Dr Takako Fujioka, a scientist at Baycrest's Rotman Research Institute.

The research team designed their study to investigate (1) how auditory responses in children matured over the period of a year, (2) whether responses to meaningful sounds, such as musical tones, matured differently than responses to noises, and (3) how musical training affected normal brain development in young children.

At the beginning of the study, six of the children (five boys, one girl) had just started to attend a Suzuki music school; the other six children (four boys, two girls) had no music lessons outside school.

The researchers chose children being trained by the Suzuki method for several reasons: it ensured the children were all trained in the same way, were not selected for training according to their initial musical talent and had similar support from their families. In addition, because there was no early training in reading music, the Suzuki method provided the researchers with a good model of how training in auditory, sensory and motor activities induces changes in the cortex of the brain.Brain activity was measured by magnetoencephalography (MEG) while the children listened to two types of sounds: a violin tone and a white noise burst. MEG is a non-invasive brain scanning technology that measures the magnetic fields outside the head that are associated with the electrical fields generated when groups of neurons (nerve cells) fire in synchrony. When a sound is heard, the brain processes the information from the ears in a series of stages. MEG provides millisecond-by-millisecond information that tracks these stages of processing; the stages show up as positive or negative deflections (or peaks), called components, in the MEG waveform. Earlier peaks tend to reflect sensory processing and later peaks, perceptual or cognitive processing.

The researchers recorded the measurements four times during the year, and during the first and fourth session the children also completed a music test (in which they were asked to discriminate between same and different harmonies, rhythms and melodies) and a digit span memory test (in which they had to listen to a series of numbers, remember them and repeat them back to the experimenter).

Analysis of the MEG responses showed that across all children, larger responses were seen to the violin tones than to the white noise, indicating that more cortical resources were put to processing meaningful sounds. In addition, the time that it took for the brain to respond to the sounds (the latency of certain MEG components) decreased over the year. This means that as children matured, the electrical conduction between neurons in their brains worked faster.

Of most interest, the Suzuki children showed a greater change over the year in response to violin tones in an MEG component (N250m) related to attention and sound discrimination than did the children not taking music lessons.

Analysis of the music tasks showed greater improvement over the year in melody, harmony and rhythm processing in the children studying music compared to those not studying music. General memory capacity also improved more in the children studying music than in those not studying music.

Prof Trainor said: That the children studying music for a year improved in musical listening skills more than children not studying music is perhaps not very surprising. On the other hand, it is very interesting that the children taking music lessons improved more over the year on general memory skills that are correlated with non-musical abilities such as literacy, verbal memory, visiospatial processing, mathematics and IQ than did the children not taking lessons. The finding of very rapid maturation of the N250m component to violin sounds in children taking music lessons fits with their large improvement on the memory test. It suggests that musical training is having an effect on how the brain gets wired for general cognitive functioning related to memory and attention.

Dr Fujioka added: Previous work has shown assignment to musical training is associated with improvements in IQ in school-aged children. Our work explores how musical training affects the way in which the brain develops. It is clear that music is good for children's cognitive development and that music should be part of the pre-school and primary school curriculum.

The next phase of the study will look at the benefits of musical training in older adults.

Boosting local immunity in nose can help treat chronic sinusitis

Fri, 15 Sep 2006 17:35:00 PST

( from http://www.rxpgnews.com ) Researchers at Johns Hopkins have evidence that curbed activity from several key chemicals on the inner lining of the nose are linked to chronic sinusitis that fails to respond to the usual current treatments.

An estimated 32 million Americans know the misery of persistent inflammation of the moist tissue that lines the nose and sinus cavities. The result is clogged passages and recurring infections, according to the U.S. Centers for Disease Control and Prevention.

Because nearly one in 10 of those treated see symptoms return within weeks or months after drugs or surgery fail to keep the sinus passages open, scientists have long suspected that these resistant cases had some underlying problem with the immune system contributing to the ailment.

In a study to be described on Sept. 19 at the annual scientific sessions of the American Academy of Otolaryngology, Head and Neck Surgery, the Hopkins team found that in chronic sufferers who failed to respond to treatment, the activity of at least four genes in the body's nasal immune defense system were severely decreased, and their production of two proteins critical to this defense was 20 to 200 times less than normal.

Comparing nasal epithelial cell samples from nine patients who benefited from surgery with nine who did not, the Hopkins team discovered suppressed levels of human beta defensin 2 (HBD2) and mannose binding lectin (MBL) in those whose symptoms returned. The proteins are naturally produced in the nose whenever the immune system detects foreign bacteria or fungi, binding to invading pathogens, inactivating them and making them easily disposed of.

An earlier study published by the same team in the March-April issue of the American Journal of Rhinology also showed that sinus tissue from people with chronic sinusitis that resisted treatment had 30 times lower than normal activity of a so-called toll-like receptor gene, TLR9.

Inside the nose, researchers say, toll-like receptor proteins (TLRs) detect invading bacteria and other pathogens in the air by attaching to their trace byproducts. Once a threat is identified, the receptors stimulate the epithelial cells to produce antibiotic proteins, such as HBD2 and MBL, to fight the invading organisms. This innate response helps prevent airborne bacteria or fungi from settling in the nose and sinus cavities, causing infection.

"Colonization with microorganisms is a common problem in patients with chronic sinusitis and polyps, but the reasons for this are incompletely understood," says Andrew Lane, M.D., an associate professor at The Johns Hopkins University School of Medicine and director of its rhinology and sinus surgery center. "Now we are uncovering new clues as to what might be wrong and perhaps, ultimately, how it might be treated.

"The nose's first line of defense is the epithelium, and when the local innate immune function is curtailed, infections can get a head start, which might serve to worsen the sinus inflammation.

"The potential is there to manipulate these chemical receptors and proteins to see if this makes patients more responsive to conventional therapy," says Lane.

The study, led by Lane, was believed to be the first to determine levels of each TLR - there are 10 - by directly measuring messenger RNA expression in sinusitis patients and those more fortunate to not have it. Scientists have known for more than a year that TLRs were present in both the healthy and sinusitis-wracked nose, but not which receptors or proteins were more important than others in the condition's chronic form. That study involved 30 men and women, mostly from the Baltimore region, who had surgery for chronic sinusitis at Hopkins. (Another 10 had no sinus problem and served as study controls.)

Those who underwent surgery did so after standard therapy using antibiotics, decongestants and steroids had failed to stop their symptoms and keep their infections from coming back. Indeed, 20 participants in the study had developed nasal polyps, which have no known cause and are especially hard to treat, researchers say. They note that polyps must often be surgically removed to allow the sinuses to drain normally.

All patients were monitored for a minimum of six months to see if any symptoms or polyps returned. Thirteen in the surgery group had recurrent inflammation within three months to one year after surgery, while the rest remained symptom free.

The Hopkins team took samples during surgery of the mucous membrane lining the nose, and using real-time polymerase chain reaction, analyzed the samples for any genetic differences between the groups.

"Surgically treating sinusitis is much like plumbing, in the sense that we try to restore normal sinus cavity drainage pathways," adds study presenter Murugappan Ramanathan Jr., M.D., a resident in otolaryngology - head and neck surgery at Hopkins. "But for the intractable cases, surgery may fail because the problem is not so much about plumbing as it is inflammation, and for this we need research at the molecular level to find a solution."

Acidic mammalian chitinase gene linked to recurrent sinusitis

Thu, 07 Sep 2006 00:39:00 PST

( from http://www.rxpgnews.com ) Although it's unclear why it's so, scientists at Johns Hopkins have linked a gene that allows for the chemical breakdown of the tough, protective casing that houses insects and worms to the severe congestion and polyp formation typical of chronic sinusitis.

A team of Hopkins sinus experts has found that the gene for the enzyme, acidic mammalian chitinase (AMCase), is up to 250 times more active in people with severe sinus inflammation that persists even after surgery when compared to patients in whom surgery is successful. Sinus surgery is usually the treatment of last resort for those who do not respond to drug therapy. But nearly one in 10 of those treated see symptoms return within weeks or months after surgery fails to keep open the nasal passages, scientists say.

The Hopkins report, published in the July issue of the American Journal of Rhinology, is believed to be the first to identify the enzyme's presence in the nose and confirm its link to sinusitis.

"This finding does not mean that there are actually parasites in the nose causing sinusitis, but our study does lend support to the concept that really severe and persistent sinusitis may be a case of a misplaced immune response directed against parasites that are not really there," says study lead author Andrew Lane, M.D., an associate professor at The Johns Hopkins University School of Medicine and director of its rhinology and sinus surgery center.

Previous research by other scientists had looked at the enzyme's tie-ins to asthma, which, like nasal polyps, is an inflammatory response of the body's immune system. The theory, Lane says, is that allergies and asthma result from genes that control the body's defenses against parasites, but these genes are dormant in healthy people. However, when turned on by so-called ghost parasites, the potent inflammatory response is medically very difficult to control.

Researchers say that although chitin, a rigid chemical compound common to fungi, insects and roundworms, is not naturally found in the human body, the presence of its corresponding enzyme and its role in the buildup of mucus and fluids, and polyp formation makes the enzyme a legitimate target for drug therapies to block its production and action.

"If we can selectively shut down the antiparasite immune response, we could potentially have new treatments for these airway diseases of the lung and nose," says Lane.

New therapies are needed, he says, as an alternative to long-term steroids, which block the inflammatory chemical pathway but also have debilitating side effects, including loss of bone density, cataracts in the eye and weight gain.

An estimated 32 million Americans suffer from persistent inflammation of the tissue that lines the nasal and sinus cavities, according to the United States Centers for Disease Control and Prevention.

Thirty-three men and women participated in the two-year study at Hopkins, designed to find out if any of the genetic traits already known to be common in asthmatics were as active in patients with sinusitis. Twenty-two were scheduled to have surgery for sinusitis, while the remaining 11 served as study controls, having surgery for some other ailment than sinusitis.

All those who underwent sinus surgery did so after standard therapy using antibiotics, decongestants and steroids had failed to stop their symptoms and keep their sinus inflammation from coming back. They also had nasal polyps, or tissue outgrowths resulting from the inflammation, which, Lane says, are particularly hard to treat.

In the surgery, a thin, tube-like endoscope is inserted into the nose, with a camera attached to provide a close-up view of the nasal and sinus passages. Slender surgical instruments placed alongside the endoscope allow surgeons to cut away inflamed tissue and polyps, clearing a path for the sinuses to drain normally. Lane says that if left untreated, polyps can lead to severe blockage and recurring infections.

All patients were monitored for a minimum of nine months to see if polyps and their resulting symptoms returned. Ten in the surgery group had their polyps return within six months, while 12 remained symptom free.

The Hopkins team took samples during surgery of the mucous membrane lining the nose, and using real-time polymerase chain reaction tests, analyzed the samples for any genetic differences between the groups.

When researchers initially compared all the nasal tissue samples, they found that half had the gene for AMCase turned on, or expressed, to make the chitinase protein. During follow up, they found that the 10 patients who had their polyps return had exceedingly higher levels of AMCase expression than the other sinusitis patients and controls. Gene expression of another inflammatory protein, called interleukin-13, already known to be high in asthmatics, was also found to be elevated in those with polyps, but the levels of interleukin-13 did not have the same predictive value as the elevated expression of AMCase, researchers say.

Lane adds that future research will have to determine if high genetic expression of AMCase is an underlying cause of inflammation or if AMCase is simply one of many chemicals produced by cells in the nose in response to chronic inflammation.

The next phase of their research, he says, is to look for what triggers the anti-parasite response. However, Lane cautions that this reaction against parasites may come at the expense of the nose's ability to ward off other invaders, such as bacteria, viruses or fungi.

"The epithelial cells lining the nasal and sinus cavities play an important role as first responders of the immune system," he says. "But when they are distracted fighting non-existent parasites, they cannot deal well with the very real microbes continuously coming into the nose."

This, Lane notes, may promote growth of bacteria and fungi in the nose, which is a common finding in those with chronic sinusitis with polyps.

Brain enzyme treatment relieves memory lapse in Alzheimer's mice

Thu, 24 Aug 2006 04:00:00 PST

( from http://www.rxpgnews.com ) An enzyme that helps neurons rid themselves of excess or aberrant proteins is required for normal brain function, according to a new report in the August 25, 2006 issue of the journal Cell, published by Cell Press. What's more, by increasing brain levels of the enzyme in mice with Alzheimer's symptoms, the researchers found they could reverse lapses of memory characteristic of the debilitating disease.

Treatments that elevate the protein, known as ubiquitin C-terminal hydrolase L1 (Uch-L1), might therefore have potential as a new therapy for Alzheimer's disease, according to the researchers. Currently available therapies have almost exclusively targeted amyloid beta (Aß), the protein responsible for the amyloid plaques that riddle the brains of patients with Alzheimer's disease, they added.

By injecting what is essentially a Uch-L1 drug to raise its levels in the brain, we were able to restore a great deal of brain activity in a transgenic mouse model of Alzheimer's disease, said Michael Shelanski of Columbia University.

While amyloid beta is certainly a key player in Alzheimer's disease--and efforts to reduce it remain a worthy goal--our results show that, even in the presence of the plaque, damage to memory can be reversed.

The findings suggest that neurons' protein-ridding machinery, the so-called ubiquitin/proteasomal pathway, may play an important early role in the pathogenesis of Alzheimer's disease, he added.

Ubiquitin is a tag that marks proteins for destruction by the cellular garbage disposal known as the proteasome, Shelanski explained. Uch-L1 acts as the proteasome's gatekeeper, he added. Before proteins can be eliminated by the proteasome, Uch-L1 must remove their ubiquitin tag.

Earlier studies found that the brains of Alzheimer's disease patients show an accumulation of ubiquitin-tagged proteins, suggesting some defect of the protein degradation machinery, the researchers noted. Studies of the brains of humans with Alzheimer's after death found evidence that the proteasome remained intact but largely unable to degrade proteins.

Interestingly, Uch-L1--a protein found almost exclusively in nerve cells--was also found at reduced levels in the Alzheimer's brain. Unpublished studies by Shelanski's group found that cells treated with Aß exhibited a rapid drop in Uch-L1, he said.

To further investigate in the current study, the researchers treated brain slices with a chemical that blocks Uch-L1 function. The treated brain tissue displayed a decline in long-term potentiation (LTP), a process whereby nerve connections are strengthened. LTP is regarded as the cellular basis for learning and memory.

Treatments that restored Uch-L1 levels corrected deficits in nerve transmission both in brain slices treated with Aß and in slices taken from transgenic mice with mutations that lead to elevated Aß and associated cognitive decline.

The researchers next asked whether Uch-L1 played an important role in fear conditioning, a form of learning known to be impaired in several mouse models of Alzheimer's disease.

For fear conditioning, mice treated with the Uch-L1 inhibitor and control mice were placed in a novel context (a fear-conditioning box) and exposed to a tone paired with a mild foot shock. Their ability to learn fear was tested 24 hr later by measuring freezing behavior in response to the box or the auditory cue. Contextual versus cued responses represent different forms of learning that depend on different parts of the brain.

A day after their exposure to the shock, mice with reduced levels of Uch-L1 showed a decrease in freezing behavior to 65% that of normal mice when placed in the box. The differences between treated and untreated mice persisted 7, 14, and 21 days after exposure to the electric shock, they reported.

On the other hand, the mice showed no differences in response to the auditory tone, suggesting variation among brain regions in the role of Uch-L1.

In mice with symptoms that mimic those found in patients with Alzheimer's disease, treatments that raised Uch-L1 greatly increased their freezing time compared to their transgenic littermates when contextual learning was assessed over time, the researchers found. Improvements in the treated animals' ability to establish a memory for fear did not depend on changes in Aß levels.

The findings provide a new window into the Alzheimer's brain that could lead to new therapies, the researchers said.

The rapid fall in Uch-L1 activity in response to Aß raises the possibility that, in the Alzheimer's brain, Aß initiates a signaling cascade that results in the partial inhibition of proteasome activity more rapidly than is likely as the result of the accumulation of misfolded or undigestable proteins.

Our data suggest that Uch-L1 could be an attractive target for the development of new therapeutic approaches to Alzheimer's disease, either alone or in combination with therapies that alter Aß levels.

NIH turns to FSU for top research on learning disabilities

Tue, 11 Jul 2006 04:00:00 PST

( from http://www.rxpgnews.com ) Tallahassee, Fla. -- Florida State University has been awarded a $6-million grant from the federal government over five years to fund research efforts aimed at more effectively understanding, predicting and preventing the development of learning disabilities such as dyslexia in children, it was announced today.

The grant will fund the creation of a National Institutes of Health (NIH) Multidisciplinary Learning Disabilities Center at FSU. The center, which will be one of only four in the nation, represents the NIH's flagship research program for learning disabilities.

Dyslexia is a learning disorder marked by impairment of the ability to recognize and comprehend written words. Although once thought of as visual disorder, scientists now know that the condition's manifestations -- misspellings, reversing letters and words, even writing backwards -- spring from an inability to recognize sounds, not visual cues.

Many kids with reading disabilities really aren't identified until the second grade, said Richard K. Wagner, FSU's Alfred Binet Professor of Psychology and a Distinguished Professor of Psychology. As the principal investigator for the NIH grant, he will oversee the work of the Multidisciplinary Learning Disabilities Center.

The center will enable FSU researchers to conduct behavioral and genetic studies involving thousands of Florida children with dyslexia. The center will be an arm of FSU's Florida Center for Reading Research (www.fcrr.org), which was itself established in 2002 as a cornerstone of Gov. Jeb Bush's Just Read, Florida! initiative to have all schoolchildren in the state reading at their grade level by the year 2012.

Our hope is to develop ways of diagnosing dyslexia and other learning disabilities at a younger age so that these children have greater chances of leading a happy, productive and successful life, Wagner said. And it's a phenomenal opportunity for FSU because we will get to participate in the NIH's premier research into dyslexia.

Wagner said the center will conduct several studies involving large numbers of volunteers. In one of these, FSU researchers will identify a sample of 500 Florida families with members who have severe reading problems. In addition to educational and psychological testing, DNA samples will be taken from the volunteers to examine possible genetic components of their learning disabilities.

FSU also plans to perform a large-scale study of twins.

We will be searching for 9,000 sets of twins from throughout the state, Wagner said. After we identify them, we will seek parental permission to access their school records. Specifically, we will be looking for variability in their reading skills.

In addition to Wagner, nearly two dozen faculty members and post-doctoral researchers from FSU's departments of psychology and communication disorders, College of Education, and Florida Center for Reading Research, as well as four molecular geneticists from the Yale University School of Medicine, will participate in five major research projects under the NIH grant.

For more than 20 years, Rick Wagner has been a leading scholar in the areas of learning disabilities, dyslexia and cognitive psychology, said Joseph K. Torgesen, director of the Florida Center for Reading Research. I am delighted that he will have the opportunity to put his expertise to use in overseeing such important research into the study of dyslexia.

Chronic middle ear infections linked to resistant biofilm bacteria

Tue, 11 Jul 2006 04:00:00 PST

( from http://www.rxpgnews.com ) Direct evidence of bacterial biofilms has been found on the middle ear tissue of children who suffer from chronic ear infections, according to a study published today in the Journal of the American Medical Association (JAMA) by researchers from the Allegheny Singer Research Institute (ASRI) at Allegheny General Hospital in Pittsburgh, the Medical College of Wisconsin and Children's Hospital of Wisconsin in Milwaukee.

Biofilms are antibiotic resistant colonizations of bacteria that attach to surfaces and form a slime-like barrier that acts as a formidable defense mechanism, protecting the bacteria from eradication.

The discovery of biofilms in the setting of chronic otitis media represents a landmark evolution in the medical community's understanding about a disease that afflicts millions of children world-wide each year and further endorses the emerging biofilm paradigm of chronic infectious disease, said Garth Ehrlich, Ph.D., principal investigator and executive director of the ASRI Center for Genomic Sciences.

Over the past ten years, Dr. Ehrlich and J. Christopher Post, M.D., Ph.D., FACS, an Allegheny General Hospital pediatric ear specialist and medical director of the Center for Genomic Sciences, have pioneered the biofilm theory to explain the persistence of chronic ear infections. In 2002, the team published in JAMA (Apr 2002; 287: 1710 1715) the first animal evidence of biofilms in the middle ear, setting the stage for the current clinical investigation.

According to co-investigator Joseph E. Kerschner M.D., Today's study completely alters the concept about how physicians should approach the treatment of children with otitis media. This historic finding sheds new light on the decreasing efficacy of antibiotics in treating kids with ear infections and has serious implications about the future direction of therapeutic research. Dr. Kerschner is associate professor of otolaryngology at the Medical College and chief of pediatric otolaryngology at the College and Children's Hospital of Wisconsin, a major teaching affiliate of the College.

Nearly all of the children in our study who suffered from chronic otitis media tested positive for biofilms in the middle ear, even those who were asymptomatic.

It appears that in many cases recurrent disease stems not from re-infection as was previously thought and which forms the basis for conventional treatment, but from a persistent biofilm, Ehrlich said.

Given that bacteria living in biofilms are metabolically resistant to antibiotics, this study makes a definitive, scientifically-based statement against the use of these drugs to treat children with chronic ear infections. It simply does not help the child and increases the risk of breeding more resistant strains of bacteria, he said.

Characterized as either an acute or chronic disease, otitis media (OM) is the most common illness for which children visit a physician, receive antibiotics or undergo surgery in the United States. There are two subtypes of chronic OM: recurrent OM (ROM) is diagnosed when children suffer repeated infections over a span of time and during which clinical evidence of the disease resolves between episodes, and chronic OM with effusion is diagnosed when children have persistent fluid in the ears that lasts for months in the absence of any other symptoms except conductive hearing loss.

Though antibiotics have proven to be effective for children with acute OM where biofilms have not yet formed, those with chronic disease typically benefit little from the drugs and more so from myringotomy, a surgical procedure in which small tubes are placed in the eardrum to continuously drain infectious fluid (called effusion).

Working with Dr. Kerschner, Drs. Ehrlich and Post obtained middle ear muscosa or membrane tissue - biopsies from children undergoing myringotomy for OM with effusion (OME) and ROM. The team gathered uninfected mucosa biopsies from children and adults undergoing cochlear implantation as a control.

Using advanced confocal laser scanning microscopy, three dimensional images were obtained of the biopsies and evaluated for biofilm morphology using generic stains and species-specific probes for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis by Luanne Hall Stoodley, Ph.D. and her ASRI colleagues. Effusions, when present, were also evaluated for evidence of pathogen specific nucleic acid sequences (indicating presence of live bacteria).

The study found mucosal biofilms in the middle ears of 46/50 children (92%) with OME and ROM. Biofilms were not observed in eight control middle ear mucosa specimens obtained from cochlear implant patients.

Our findings demonstrate what we have suspected for years, that children with chronic otitis media have biofilms in their middle ears. Healthy children do not. The idea of treating recurrent disease with antibiotics therefore is not supported by the scientific evidence, Dr. Post said. Chronic middle ear infection is not the result of a sterile inflammatory process, but an indolent bacterial disease. Understanding that, we can now begin to explore more effective treatments for it.

Dr. Post said future therapies may be medical, technological or biological in nature, including the use of probiotics an approach in which children are deliberately populated but not infected with good bacteria that prevent the formation of biofilms. In an ongoing study at the University of Florida, researchers are inoculating children against cavities using a bacteria that sets up house in their teeth where plaque biofilms usually grow.

The idea with chronic middle ear infections would be to engineer a bacteria that could occupy the nasopharynx but not cause recurring infection, Dr. Post said.

Until something new comes along, however, placement of ear tubes to provide children with symptomatic relief will still be necessary and recommended. Antibiotics should also continue to be prescribed for acute otitis media to help prevent potentially serious complications, such as mastoiditis and meningitis, Dr. Kerschner said.

Beta-actin mutations linked to deafness and dystonia

Mon, 10 Jul 2006 20:26:00 PST

( from http://www.rxpgnews.com ) Findings of a recent genetic study on developmental brain disorders may be the "tip of an iceberg" revealing factors involved with a number of congenital diseases, according to UC Irvine researchers.

The study is the first to find that mutations in the structural proteins in brain cells - beta-actin - are linked to disorders such as deafness and dystonia, a debilitating neural disease, and further suggests that genetic variants of these proteins may play a wider role with inherited human diseases. Study results appeared in the June issue of the American Journal of Human Genetics.

The findings give vital clues to the basis of some developmental disorders and make early diagnosis possible for diseases such as dystonia, allowing for greater treatment opportunities, said Dr. Vincent Procaccio of UCI's Center for Molecular and Mitochondrial Medicine and Genetics and lead author, though the study does not point to potential therapies.

"These types of actin proteins are prevalent throughout the body and play a key role in processes that are an essential part of development," said Procaccio, who is also an assistant professor of pediatrics. "To find that these mutations are involved with brain disorders seems to be the tip of an iceberg. Since beta-actin is involved with many developmental cell functions, it would appear that its genetic variants can be involved with a number of other congenital disorders."

Procaccio and his colleagues studied brain tissue samples from deceased twins who had a number of developmental disabilities including dystonia, a neurological disorder that causes twisting or jerking movements in parts of the body. Genetic analysis revealed mutations in the beta-actin gene. These mutations affected protein conformation, which would not allow beta-actin to bind with ATP - the chemical fuel synthesized by mitochondria that give a cell its energy.

Beta-actin is a structural protein that helps form the cytoskeleton - a cell's skeleton that gives it structure and strength. Unable to receive fuel, the mutated beta-actin proteins break down, ultimately damaging and destroying the cell. In the brain, this leads to the neural tissue damage related to congenital neurological disorders like dystonia.

Taking this information, Procaccio and his fellow researchers are working to demonstrate that beta-actin mutations are a common cause of neurological disorders. They are currently analyzing several DNA samples from patients to identify additional abnormalities. In addition, they are investigating the cellular and biophysical abnormalities resulting from beta-actin mutations, which will serve as a basis to identify other mutations and disease phenotypes arising from genetic abnormalities of beta-actin proteins.

"Ultimately, we hope to prove that the identification of genetic abnormalities of the beta-actin are likely to explain the causes of a spectrum of disease phenotypes, including congenital malformation syndromes and other inherited degenerative diseases, that are presently poorly understood," he said.

Role of Folic Acid in Treatment of Laryngeal Leucoplakia

Tue, 13 Jun 2006 02:26:00 PST

( from http://www.rxpgnews.com ) Folic acid supplements may prevent cancer progression and promote regression of disease, according to a new study. Published in the July 15, 2006 issue of CANCER, a peer-reviewed journal of the American Cancer Society, the small study found that 31 of 43 patients with the precancerous laryngeal lesion called leucoplakia demonstrated 50 percent or greater reduction in the lesion size after six months of taking folate supplements. In 12 of 31 responders, there was no evidence of the original lesion. Folate levels in the patients' blood also increased significantly from baseline while homocysteine levels decreased significantly. This study provides data to support the hypothesis that folate insufficiency is a risk factor for cancer progression.

Folate deficiency is the most common vitamin deficiency in the United States. Folate is a naturally occurring B vitamin (B-9) found abundantly in fresh vegetables and fruits. Folic acid is its more stable synthetic form found in dietary supplements and fortified foods. At the biochemical level, folate is incorporated into coenzymes that are essential in facilitating a variety of reactions in nucleic acid and amino acids metabolism. Some of which are critical to healthy life, such as DNA synthesis, DNA repair, and converting homocysteine to methionine. The latter is particularly important because excess homocysteine is linked to chronic health problems, such as cancer and cardiovascular disease.

Animal and human studies have increasingly demonstrated associations between folate deficiency, serum homocysteine elevations, and a variety of cancers. Some studies have suggested folate supplementation or at least a high folate dietary intake may protect against some cancers. This body of evidence suggests folate to be an effective chemopreventive drug. Other chemopreventive drugs are being tested, and while the retinoids demonstrate the most promise, they are highly toxic. Giovanni Almadori, M.D. of the Institute of Otolaryngology, UniversitÃ Cattolica del Sacro Cuore, Policlinico A. Gemelli in Rome, Italy and colleagues investigated the efficacy of folic acid dietary supplementation to treat precancerous lesion and prevent cancer.

The investigators enrolled 43 patients with untreated laryngeal leucoplakia and treated them with folic acid (5mg three times a day) and evaluated the progression of leucoplakia every 30 days for six months.

Over six months of treatment, 12 patients (28 percent) had complete resolution of their leucoplakia lesions; 19 patients (44 percent) had reduction of 50 percent or more in the size of their lesions and 12 patients (28 percent) had no response. Mean folate levels increased and mean homocysteine levels decreased significantly. There were no moderate or severe adverse events reported.

Comparison to another promising chemopreventive drug regimen that includes a retinoid, "our complete response rate is lower than the one reported in a smaller population," the authors write. Nevertheless, folate "is characterized by a lower grade of toxicity," and there was no progression of disease.

These results suggest, according to the researchers, "folate supplementation, alone or in combination with other chemopreventive drugs, could effectively reduce the risk of progression in an already genetically altered mucosa, especially in patients with hypofolatemia."

Duke University study finds hearing aids are underused

Fri, 02 Jun 2006 04:00:00 PST

( from http://www.rxpgnews.com ) These are among the key findings of a literature review conducted by the Medical Technology Assessment Working Group at Duke University. Researchers found consistent evidence that hearing loss contributes to a decline in quality of life, particularly among the elderly.

However, they also found no research in existence documenting how hearing devices can enhance everyday experiences.

Approximately six million people in the United States use a hearing aid, most for treating moderate hearing loss, but 35 to 50 percent of hearing aid users are not satisfied, the study found.

Hearing aids are being underused, in part the Duke team reasoned, because of social attitudes that reflect misunderstandings about hearing loss (e.g., beliefs that hearing loss is inevitable later in life) and because of the cost and possible inconvenience of hearing aids.

One area of critical need is understanding the barriers to hearing aid use that contribute to irregular use of hearing devices by those who have them, said Linda K. George, Ph.D., professor and project director of the study. Until these areas are better understood, continued innovations in hearing aid devices will be hampered.

The report noted that it would not be surprising to find that the use of devices for hearing loss is associated with substantial increases in productivity and other social contributions, but as yet, the issue has not been validated by research.

Investigators also found that research to date devotes little attention on matching consumers to specific types of hearing devices (e.g., cochlear implants, hearing aids) and the extent to which consumers can choose among devices. The Duke team urged more research be undertaken to understand the impact of hearing devices on social, emotional and physical disabilities, as well as the consumer effects of patient education on the use of these devices.

As found in other disease fields examined by the Duke team (including sensory, musculoskeletal, renal, cardiovascular, and cancer), available information on device evaluation lags substantially behind advances in technologies. For example, most of the evidence available to the researchers was based on hearing devices that have been superceded by newer versions.

The study examined the impact of medical technologies on treatment of hearing loss, with emphasis on the elderly population, and is part of larger study funded by a grant from InHealth: The Institute for Health Technology Studies, to examine the effects of medical technology on patients, particularly those who have completed treatment or received care. InHealth is a nonprofit research and education organization that studies the role, impact and value of medical technology through non-restricted grants to independent, academic investigators.

Hearing aids are a great example of how medical technology can have a profound effect on quality of life for millions of people, said Executive Director, Martyn Howgill. We need a better understanding of why people are not using hearing devices in order to improve hearing aid technology in ways that would surely aid untold millions of potential recipients.

Study shows autism-related developmental 'red flags' identifiable at age two in children

Thu, 01 Jun 2006 04:00:00 PST

( from http://www.rxpgnews.com ) The study examined development in 87 infants at 6, 14 and 24 months of age using a standardized development test. Based on data and clinical judgment at 24 months, participants were classified as: unaffected, language delayed (LD) or ASD. Researchers compared development across groups at the three target ages and observed statistically significant differences between the ASD group and the unaffected group at 14 months. By 24 months, significant differences were detectable between the ASD group and both the unaffected and LD groups.

Introducing behavioral interventions even one year earlier can make a tremendous difference in the lives of children with autism and their families, said Dr. Rebecca Landa, Director of the Center for Autism and Related Disorders at the Kennedy Krieger Institute in Baltimore, MD and lead author of the study. If we are able to educate professionals to identify red flags in development we can then recognize and diagnose the disorder at one-and-a-half or two years of age, instead of three or four, allowing for earlier intervention and ultimately better outcomes.

Participants in the study included infants at high risk for autism (siblings of children with autism), and infants at low risk (no family history of autism). Researchers measured development using the Mullen Scales of Early Learning (MSEL), a standardized test which assesses five domains of development, including: gross and fine motor; visual reception; and receptive and expressive language. At 14 months, four of the five mean MSEL scores were significantly lower in toddlers with ASD than those in the unaffected group. By 24 months, the ASD group performed significantly worse than the unaffected group in all domains of development, and worse than the LD group in three domains. Nearly half of the ASD group showed developmental worsening between 14 and 24 months.

This study and previous research studies conducted by Dr. Landa found that developmental red flags for parents and physicians to watch for include: poor eye contact; reduced responsive smiling; diminished babbling; reduced social responsivity; and difficulty with language development, play and initiating or sustaining social interaction.

With so many unanswered questions in the autism arena, we need to tackle this condition on many different fronts, said Dr. Gary Goldstein, President and CEO of the Kennedy Krieger Institute. For this reason, experts at Kennedy Krieger are not only conducting early diagnosis and intervention research, but also investigating the genetic and environmental causes of autism, as well as other potential treatment options.

Autism is the fastest growing developmental disorder in the United States. This year more children will be diagnosed with autism than AIDS, diabetes and cancer combined, yet profound gaps remain in our understanding of both the causes and cures of the disorder. Increasing our knowledge about developmental disruptions in individuals with ASD is crucial, since early detection and intervention can lead to improved outcomes in individuals with ASD.

Surgical plugs in ear's bone stops strange form of severe dizziness

Sat, 20 May 2006 04:00:00 PST

( from http://www.rxpgnews.com ) Rapid, uncontrollable eye movements that swish and thump as the eyes roll and blink. Bones that creak as the body moves. Sudden dizziness, loss of balance. Falling down after a loud noise, such as the sound of your own voice, a cough or even laughter. These are hallmarks of a debilitating and relatively rare syndrome known as superior canal dehiscence that has stumped clinicians for a long time.

Victims lose balance, fall down stairs, are unable to read or sleep due to loud noises inside their head, and some become convinced they are mentally ill, suffering from symptoms that won't yield to conventional treatment. Now, Johns Hopkins surgeons have proven that these symptoms can all be successfully treated by a single operation that plugs up a threadbare layer of bone in the inner ear.

Superior canal dehiscence occurs in roughly equal numbers of men and women and is often not diagnosed until after age 40, when symptoms, such as hearing loss, appear to worsen. However, patients often recall that initial symptoms happened much earlier in their lives.

The surgical plugging procedure can put a stop to even severe symptoms and can lead to a return to normal daily activities and, in some cases, to a mild-to-moderate improvement in hearing, says Lloyd B. Minor, M.D., the Andelot Professor and director of otolaryngology - head and neck surgery at The Johns Hopkins University School of Medicine. It was Minor who, in 1998, first clinically described superior canal dehiscence and developed the surgical techniques to repair it.

In a pair of reports believed to offer the largest followup analysis of patients after their surgery for the syndrome, a Hopkins team, led by Minor, found that plugging the superior canal where the bone casing is thin, and then covering the plug with a bone graft, prevented symptoms from recurring.

Researchers say that for patients who had already experienced some hearing loss from the syndrome, the plugging procedure - which essentially compresses and closes off the canal - often helps restore their hearing. They note that improvements in hearing occurred in five of 29 patients who underwent surgery for the disorder between 1996 and 2005.

They add that the risk of hearing loss is very low in patients who have not had previous ear surgery, with no hearing loss reported in 19 patients undergoing their first operation.

No wider than a toothpick, the canal bone in question rests at the top of the inner ear's three semicircular canals. Thinning due to failure of bone to develop properly and maintain its strength over time makes the ear hypersensitive to sound and motion. A common complaint is autophony, where patients hear their own voices reverberating inside their head. For some patients, even a conversational level of loudness can produce symptoms strong enough to cause severe discomfort.

The Hopkins surgeons will present their findings from a decade's worth of research this week at the Combined Otolaryngological Spring Meeting (COSM) being held in Chicago, Ill. Since the team saw its first patient with the condition in 1995, they have successfully operated on 39.

While no survey exists of just how widespread is the condition, Minor says about two-thirds of those who have it will never require surgery. But for the remaining one-third who undergo surgery to repair the bone casing in the ear, the surgery in most cases fixes the disturbance in balance caused by the dehiscence.

In their latest findings, researchers report that in 19 patients undergoing analysis of abnormal eye movements, surgery led to a resolution in each case of vertigo, or dizziness, brought on by loud noises.

The surgery, which takes from four to six hours, is extremely delicate and requires access to the inner ear, a space the surgeons describe as no wider than the diameter of a dime. They first cut a hole above the ear and open the skull, after which they move aside a part of the brain so that they can reach the three paired canals that form the inner ear, of which the superior canal is the one closest to the top of the head. The plug mixture is made up of small chips of the patient's bone and fibrous tissue taken from the area of incision and the temporary opening the surgeons make in the skull.

In the first study to be presented at the COSM, audiograms were performed both presurgery and postsurgery to assess hearing levels. In the second study, tests of eye movements in response to sound and to rapid head movements were used to assess the inner ear's balance function after surgery.

Minor cautions that the surgery has the potential to damage balance, but notes that the studies suggest the other two balance canals, the posterior and horizontal canals, can adapt. Postsurgery results showed a 44 percent reduction in the function of the superior semicircular canal, while function in the other two canals was typically not affected. This shows, researchers say, that plugging typically limits sensation in just the one canal.

The results should allow surgeons to better counsel their patients with superior canal dehiscence on what is the likely improvement to their hearing and balance after either procedure, according to the lead authors of the studies, John Carey, M.D., an associate professor, and Charles Limb, M.D., an assistant professor, both in otolaryngology - head and neck surgery at Hopkins.

However, Limb notes that only long-term data from postsurgical monitoring of patients for longer than 10 years will truly confirm if surgical treatments hold steady or decline at some point. The Hopkins team continues to monitor how its patients are doing.

Although research on the condition is relatively new, Minor believes the underlying cause of the syndrome is an opening in a layer of bone that fails to develop to normal thickness during or after birth. The open balance canal can then respond to sounds and to pressure induced by activities such as coughing, sneezing or straining. And this abnormal activation of the canal is then misinterpreted by the brain as a head movement that leads patients to lose their balance and to have abnormal eye movements.

According to Minor, normal inner ear bone thickness is on average 0.7 millimeters. And while the condition can affect both ears, in patients with just one ear affected, the other ear has less-than-normal bone thickness.

Diagnosing the condition consists of CT scans of the head to gauge the thickness of the bones in the inner ear, as well as balance tests to record how various sounds trigger body motions, including eye movements and contractions of muscles in the neck.

What is the sound of one person talking? New speech collection tells all, syllable by syllable

Mon, 01 May 2006 04:00:00 PST

( from http://www.rxpgnews.com ) All the scientists really cared about was how they said it.

In a lab at Ohio State University , researchers recorded 30- to 60-minute casual interviews with these residents, talking about how Columbus has changed over the years, how families should get along, as well as issues in sports, traffic and politics.

The participants were told that the purpose of the study was to learn how people express everyday opinions in conversation. But when the interviews were over, the scientists didn't even examine the views that were expressed.

Instead, they painstakingly listened to every spoken word indeed every syllable - along with coughs, laughs and pauses in the conversation, and then labeled what actually was spoken.

The result is a 306,652-word repository of how people in central Ohio speak. Now scientists from around the world, and in a variety of disciplines, can use the collection called the Buckeye Speech Corpus to advance their research. (Researchers refer to a collected body of recordings as a corpus.)

A critical part of communication is how your ears translate the sounds coming out of my mouth into recognizable words, said Mark Pitt, one of the leaders of the project, and professor of psychology at Ohio State.

You don't have to go to school to learn how to do it. It is fast and efficient. The scientific question is 'how is this done?' The corpus will help researchers find answers to that question and many others.

Other members of this large research team include Eric Fosler-Lussier, assistant professor of computer science and engineering, and Elizabeth Hume, professor of linguistics, both at Ohio State.

The corpus, available to researchers on DVD, includes the actual recordings of the interviews, a written transcript, and several levels of labeling. The first half of the corpus was officially released in March. A typical display of a stretch of speech from the DVD shows two visual representations of speech from one of the talkers, indicating volume and frequency. Below the displays is a line with a transcription of what the speaker is saying. Then comes a line of phonemic labeling, which shows how each word spoken was pronounced similar to the pronunciation guides found in a dictionary.

This phonemic labeling is a key part of the corpus, because in casual conversations, people don't always use the proper English pronunciations they were taught in school, said Laura Dilley, a post-doctoral researcher in psychology who works on the corpus.

It's interesting because of the many kinds of modifications that happen to the acoustics of speech in conversations, Dilley said. For example, we may pronounce 'don't you' as 'don'tcha' when we are talking.

By looking at the phonemic transcriptions we can tell exactly how a person pronounced a word. And from that scientists may be able to make some inferences about why people produce the sound one way as opposed to another.

The interviews are also labeled to show when people made non-word sounds during a conversation, such as a cough.

Even laughs are noted, because some researchers may be interested in how that is part of a conversation, Pitt said. It can convey meaning as well.

The 40 residents were interviewed in 1999 and 2000. But it has taken until this year to label the speech of half of the speakers, Pitt said. The data from the remaining 20 participants should be available by the end of the year.

Collecting the interviews took a long time. But what really takes a long time is labeling them. Researchers had to listen to each conversation and figure out what sounds of the language the speakers said or didn't say. It's very difficult and very time consuming, he said.

When you actually sit down to label each word, they can blend together and be very difficult to identify, Pitt said. Sometimes you scratch your head trying to figure out how to label the speech. But when you're just listening to it as part of the conversation, it is all perfectly intelligible. That's part of the mystery of communication that scientists are trying to figure out.

A combination of factors makes the Buckeye Speech Corpus a unique resource for researchers, according to Pitt and Dilley. For one, it is one of the largest corpora of high-fidelity, conversational speech available. Other corpora involve speakers reading words directly from a text, but that is very different than conversation. There are also corpora of conversational speech recorded over the telephone, but that does not have the high fidelity of this corpus, and the dynamic of face-to-face conversation.

Another key difference is that the Buckeye Corpus is available free to researchers, both in academia and industry.

Although the Buckeye Corpus has been available for only a few weeks, researchers from around the world are already ordering copies of it. A researcher from Italy ordered the corpus to study slips of the tongue, such as when people accidentally substitute one word for another that sounds similar (saying rabbit instead of habit).

Pitt and Dilley expect a lot more interest in the corpus.

Across a variety of fields -- in communication, speech sciences, linguistics, speech and hearing, computer science, psychology the corpus will provide different uses, Pitt said. It was created for all these scientific communities.

Computer scientists could use the corpus to help improve speech recognition software. Communication researchers will find it useful to study conversational dynamics. Psychologists will be interested in what listeners are faced with in terms of the physical and acoustic properties of speech.

Eventually, the corpus will have a search function that will make it even more useful. If a researcher wanted to look up all the uses or pronunciations of a certain word in the interviews, he or she could do that, Dilley said.

The work of transcribing and labeling the interviews allowed the Ohio State researchers to uncover some interesting facts about how people speak in conversation.

For instance, the speakers spoke a total of 306,652 words, but only 9,600 different words. Almost 80 percent of the total words spoken were one-syllable words. One and two-syllable words made up more than 90 percent of the total words spoken.

Slightly more than half of the words spoken (57 percent) were function words words like prepositions, pronouns and conjunctions that have mostly grammatical uses within a sentence. The remaining 43 percent were content words, which includes nouns, verbs and adjectives.

The Buckeye Speech Corpus project was originally funded with a seed grant from Ohio State's Office of Research. It has since received funding from the National Institute on Deafness and Other Communication Disorders, which is part of the National Institutes of Health.

Ohio State may be emerging as a center for corpora of conversational speech, Pitt said, as the Department of Speech and Hearing Sciences was just awarded a large, multi-year grant from NIH to collect interviews with speakers native to Ohio, Wisconsin, and western North Carolina.

Researchers learn more about ways to regenerate the ear's hearing cells

Fri, 28 Apr 2006 04:00:00 PST

( from http://www.rxpgnews.com ) In these first studies of the role of the Rb protein in the ears of postnatal mice, we have confirmed that under the right conditions mature hair cells can go through the cell cycle and produce new, functioning hair cells. But we've also confirmed that you need to block Rb reversibly and at an early stage of development, otherwise the hair cells will die, says Zheng-Yi Chen, DPhil, of the MGH Neurology Service, the study's senior author. In 2005 Chen was named to the Scientific American 50, the magazine's annual list of outstanding leaders, for this continuing research project.

Named for the hair-like projections on their surfaces, hair cells form a ribbon of vibration sensors along the length of the cochlea the organ of the inner ear that senses sound where they convert sonic vibrations to electrical signals that are carried to the brain. The cells are very sensitive to damage from excessive noise, infections and toxins. Once damaged, hair cells do not naturally regenerate in mammals, and their death accounts for most types of acquired hearing loss.

All cells grow and divide through a process called the cell cycle, and many proteins have been identified that control different cell cycle phases. In 2005 Chen's group published a paper in the journal Science reporting that the Rb protein, known to suppress the cell cycle, could be important for halting the cell cycle in hair cells. They used a genetically modified mouse strain in which Rb was no longer made in the inner ear. By examining the inner ears of mouse embryos that strain did not survive past birth the researchers found more hair cells in the knockout mice than in the ears of normal mice at the same stage of development. The additional cells looked and functioned like normal hair cells and appeared to be actively regenerating.

For this followup study, the researchers developed a new strain of inner-ear Rb-knockout mice that survive for up to six months past birth. Their investigation of the effects of Rb deletion on the hair cells of the inner ear finds differences between the auditory portion of the organ, which controls hearing, and the vestibular area, which is involved with balance. While the Rb-negative auditory hair cells in early postnatal mice are dividing and growing, the cells do not mature properly and eventually die, resulting in the mice becoming deaf by the age of 3 months. Vestibular hair cells, however, appear to grow and mature relatively normally and continue cell division even in mature mice. Adult Rb-knockout mice maintain some vestibular function, indicating that those hair cells are contributing to their sense of balance at the system level.

We've shown that vestibular hair cell regeneration may be achieved and may be less of an obstacle than auditory cell regeneration, Chen says. Now we need to find ways to create a similar system in the auditory cells, and this new model will help us better understand the mechanisms behind functional hair cell regeneration. Our next step will be developing a transient, reversible block of Rb function to assess its role in both types of hair cell. Chen is an assistant professor of Neurology of Harvard Medical School (HMS).

Technology to improve learning for visually-impaired children

Thu, 27 Apr 2006 04:00:00 PST

( from http://www.rxpgnews.com ) We are experimenting with how to use different senses to partially replace missing visual capabilities, especially in tasks that are central in the construction of the system, he says. Empirical research of collaborative and cross-modal haptic interfaces for visually-impaired children is one of the most important research activities.

Haptic technology interfaces with the user through the sense of touch. This emerging technology adds the sense of touch to previously visual-only solutions. MICOLE's software architecture and applications are multimodal, that is, they use hearing and touch to complement different levels of visual disability.

Their work extends beyond developing an assistive tool. In addition to MICOLE's immediate value as a tool, the system will have societal implications by improving the inclusion of the visually disabled in education, work and society in general, explains Raisamo.

Initial field studies involved interviews with teachers, children and related user organisations as well as observations of actual group work in schools. The objective was to determine how visually-impaired children collaborate in school with peers and teachers, and to understand to what extent they engage in group work.

The interaction among the pupils, with teachers and with their peers is very important for learning, says Raisamo. We know that collaborative learning has benefits because the pupils learn through a dialogue with their peers and construct their own knowledge by doing tasks together with others.

Field study results from Austria, Finland, France, Greece, Ireland, Lithuania, Sweden and the UK showed major differences in the education of visually-impaired children, however, they revealed many similarities regarding aspects of collaboration. Based on these results, a prototyping workshop was held in Stockholm where the school situation for such pupils was addressed. Various hapitc and auditory applications developed within MICOLE were assessed and new designs formulated.

He notes there are no specific requirements for the users of the system. The system adapts to the users. It is aimed at visually-impaired children, but because it facilitates collaboration among sighted and visually-impaired children, it also supports sighted children.

A multimodal system with visual, audio and haptic feedback can support many kinds of users with disabilities because missing one of the modalities does not make the system unusable, Raisamo adds.

Project partners have developed or tested 16 different interfaces and application prototypes, such as explorative learning of the earth's internal layers, rhythm reproduction, a tactile maze game, virtual maracas (percussion instruments), post-its with a haptic barcode, an electric circuit browser, a haptic simon game, memory games, a haptic turtle and a haptic game of the classic first video game, pong.

For example, to better teach natural phenomenon, such as seasons, gravity and the solar system, project partners constructed a system using proactive agents that offer the pupil help when necessary. The user decides whether to accept help comprised of visual, auditory and haptic feedback to present content.

Project partners include European and world leaders in the area of haptics and multimodal-human-computer interaction. For example, Reachin Technologies AB is a world leader in haptic technology; France Telecom has experience in developing applications for the blind.

MICOLE offers an outstanding opportunity and the critical mass for the consortium to integrate and realise results of their earlier work and to test the most novel ideas to meet the needs of the visually impaired, says Raisamo. The results are expected to make a valuable European contribution to the development of the information society and real-world equality for visually-disabled children, empowering them as future citizens.

The multimodal software architecture to create new applications is under construction. Scientific results from multimodal navigation and cross-modal presentation of information are being fed in to the team's work. The three-year project is scheduled to end in August 2007.

Hyperactivity, attention deficit, sleepiness, and ADHD often improves after tonsillectomy - Study

Mon, 03 Apr 2006 14:52:00 PST

( from http://www.rxpgnews.com ) In fact, about half of the children in the study who were found to have Attention-Deficit/Hyperactivity Disorder before tonsil surgery no longer met criteria for this diagnosis one year later. Other cognitive and behavioral issues also improved.

On the whole, the 78 children who had their tonsils out were much more likely than a comparison group of 27 children to have had behavior and sleep problems at the start of the study. But by the end of the study, tests showed little difference between the two groups.

The research paper is published online in the April issue of the journal Pediatrics by a team from the University of Michigan Health System. Data were collected from rigorous tests of sleep and breathing at night, and attention and behavior during the day. The results support previous observations of a link between children's sleep-related breathing problems -- such as snoring and breathing interruptions called apneas -- and daytime behavior problems.

The researchers caution that their results do not yet prove cause and effect, and that tonsillectomy is not usually a "cure" for ADHD. But, they say, the growing body of evidence on this issue suggests that a significant number of children with inattention, hyperactivity, or sleepiness during the day and also sleep-breathing problems at night may benefit during both the night and day by tonsillectomy, an operation that was once performed on more than a million children a year but has become much less common in recent decades.

The procedure, also called adenotonsillectomy when both the tonsils and structures called adenoids are removed, is now performed on a few hundred thousand children a year. Nearly half of them have the surgery because enlarged tonsils and adenoids block the flow of air through their throat and impair their ability to breathe, and most of the rest because of repeated ear and throat infections. Almost all of the children who had surgery in the new study were thought by their surgeons to have symptoms of sleep apnea.

"These findings help support the idea that sleep-disordered breathing is actually helping to cause behavioral problems in children, and making them sleepy," says lead author Ronald Chervin, M.D., M.S., director of the U-M Sleep Disorders Center and co-leader of the U-M Center for Sleep Science. "This is one of the first studies to document, using gold-standard measures, that all of these sleep and behavior problems tend to resolve one year after enlarged tonsils and adenoids are removed."

One of the most striking findings that children once diagnosed with ADHD no longer had the condition a year after tonsillectomy occurred in 11 of 22 children with ADHD. This means that sleep and breathing problems are only part of the ADHD puzzle, and that tonsillectomy isn't a cure-all for ADHD, notes Chervin, an associate professor of neurology at the U-M Medical School.

A few children even developed new ADHD a year after surgery. Chervin says this supports previous evidence that damage from sleep-disordered breathing may occur in early years, even though the result is not seen until later. If confirmed, this would mean that early diagnosis and treatment of sleep-disordered breathing are particularly important.

When they entered the study, and before any surgery, all the children in the study had their behavior assessed by a child psychiatrist, as well as by their parents, who completed standardized questionnaires. The children had their attention span and short-term memory measured using a standard computer-based test, and spent a night in the U-M Michael S. Aldrich Sleep Disorders Laboratory. There, they were monitored for breathing problems during sleep, and also for their level of sleepiness, as measured by how long it took them to fall asleep in a series of naps.

All the tests were repeated a year after the children had a tonsillectomy at U-M C.S. Mott Children's Hospital or St. Joseph Mercy Health System, performed by otolaryngologists (ear, nose and throat doctors) from any of eight practices in the local area. For the comparison group, who had non-tonsil surgery or no surgery, the second round of testing was performed a year after initial tests. The researchers analyzed the test results using sophisticated statistical analysis.

Among those children scheduled for tonsillectomy, the sleep-breathing tests showed that before surgery, half of them had obstructive sleep apnea (OSA), usually in the mild to moderate range, in contrast to only one of the comparison children. At the end of the study, only 12 percent of the tonsillectomy patients had OSA, including one patient who hadn't had it before tonsillectomy, compared with 3 children among the comparison patients who completed the sleep test series. In all, five children did not complete follow-up tests.

In people of any age, OSA occurs when breathing stops and starts repeatedly during the night, often in part because the throat is narrowed or blocked, keeping sufficient air from getting into the windpipe and lungs. People with sleep apnea often snore, or snort and gasp throughout the night, though not all snorers have sleep apnea. About one to three percent of children have OSA, including a good number of those children who snore regularly. Enlarged tonsils are a common cause of the sleep disorder in children, while obesity, allergies, acid reflux and structural abnormalities in the head and neck also contribute to it in children and adults.

Interruptions in breathing during sleep can cause the brain to "wake up" to some extent, even if the sleeping person is not aware of it. These repeated interruptions disturb the sleep patterns that are essential to a good night's sleep and are thought to be the reason why daytime behavior might be affected by poor breathing during the night. Sleep apnea is also linked to heart and blood pressure problems, and in children, to slow growth.

The researchers also compared the tonsillectomy patients who had had OSA before surgery with those who had not. In all, the children who had not had it before tonsillectomy were just as likely as the children with OSA to have a high score on standard tests of hyperactivity, and just as likely to have behavioral improvement after tonsillectomy.

As a result of this finding and other data, the study adds to an issue that's currently puzzling sleep researchers: Why the results of sleep tests to monitor brain activity and breathing don't always correlate with children's daytime behavior. The standard measures used to assess children's sleep problems, and the threshold levels that are used to assess the severity of a sleep problem, may need to be reevaluated, says Chervin.

To explore this issue further, he and his U-M colleagues are now recruiting patients for a study that will compare those standard measures with new ones, including a measure of how hard children work to breathe during the night, and another that looks for subtle changes in brain activity with every labored breathing cycle.

The bottom line for parents, Chervin and his colleagues say, is that any child who snores regularly, or has other signs of breathing problems during sleep, may benefit from an evaluation for sleep problems and perhaps from tonsillectomy especially if the child is also having behavior problems at home or school.

"If you have a child who has difficulties with attention deficit, hyperactivity, or daytime sleepiness, there may be something that can be done about it if the child proves to have a sleep disorder," Chervin says. "An undiagnosed sleep disorder is not the solution for all children with ADHD. But it could be something worth looking into for a substantial minority, especially those children with symptoms that suggest a sleep disorder such as sleep apnea."

Scientists discover reason behind ear canal in Chinese frog: Ultrasonic communication

Wed, 15 Mar 2006 05:00:00 PST

( from http://www.rxpgnews.com ) Amolops tormotus, also referred to as the concave-eared torrent frog, is the first non-mammalian species found to be capable of producing and detecting ultrasounds for communication, much like dolphins, bats, and some rodents. It does so, the researchers report, to make itself heard above the din of low-frequency sounds produced in its surroundings so that it can communicate territorial information to other males of its species. In addition to helping researchers puzzle out how the ear evolved, the research may one day enable scientists to develop new strategies or technologies that help people to hear in environments in which there is a lot of background noise.

In the study of communication and communication disorders, researchers can gain a great deal of insight by looking at the natural world, says James F. Battey, M.D., Ph.D., director of the NIDCD. The more we can learn about the extraordinary mechanisms that Amolops and other animals have developed to hear and communicate with one another, the more fully we can understand the hearing process in humans, and the more inspired we can be in developing new treatments for hearing loss.

Ultrasounds are high-pitched sounds more than 20 kilohertz (kHz) in frequency, exceeding the upper limit of sounds detectable by humans, and far higher than the 12 kHz frequencies that most amphibians, reptiles, and birds are capable of hearing and producing. Key parts of the ear must be specially adapted to detect ultrasounds namely, the eardrum must be very thin to vibrate effectively at these high frequencies, and the bones of the middle ear must be extremely lightweight in order to transmit ultrasonic vibrations to the inner ear. The presence of an ear canal not only protects A. tormotus's thin and fragile eardrum from the environment but also lessens the distance between the eardrum and the inner ear, thus allowing the bones of the middle ear to be shorter, and as a result, lighter in weight.

Researchers have known for several years that A. tormotus males produce high-pitched, birdlike calls that extend into the ultrasonic range. What remained to be tested was whether the ultrasounds were a byproduct of the frog's sound production system or were heard and responded to by other males of that species. Researchers Albert S. Feng, Ph.D., an auditory neuroscientist at the University of Illinois, Urbana-Champaign, and Peter M. Narins, Ph.D., who studies auditory behavior, neurophysiology, and mechanics at the University of California, Los Angeles, and collaborators conducted behavioral and physiological studies to investigate A. tormotus's hearing ability.

The researchers first wanted to know if A. tormotus can hear ultrasounds. They recorded a male's call, split it into the audible components and ultrasonic components, and observed the responses of eight A. tormotus males to each of the split sounds. Five of the eight frogs produced calls in response to the audible, ultrasonic, or both components of the species call and three did not. Results of the behavioral observations showed that males were capable of hearing and responding to ultrasounds.

The researchers then measured the electrical activities in A. tormotus's midbrain that is involved in sound processing and found marked electrical responses to sounds extending into the ultrasonic range both in the averaged response of a population of nerve cells in the brain and in single nerve cells confirming the frog's capacity for hearing ultrasounds. (Interestingly, a different species that lives in similar environments also demonstrated an ability to hear ultrasounds.)

The next steps for the researchers will be to study A. tormotus's eardrum, as well as hair cells, the sensory cells in the inner ear that are essential for hearing, to learn how they are able to detect ultrasounds. They also are interested in learning why only the males possess recessed eardrums while the females do not.

Other researchers involved in the study represent the Chinese Academy of Sciences Shanghai Institutes of Biology Sciences and Institute of Biophysics. Additional funding sources for the study include the National Science Foundation and China's State Key Basic Research and Development Plan and National Natural Sciences Foundation.

Rheumatoid arthritis does not increase risk of hearing loss, Mayo Clinic study finds

Mon, 06 Mar 2006 05:00:00 PST

( from http://www.rxpgnews.com ) The study results will be presented Monday at the American Auditory Society annual meeting in Scottsdale, Ariz.

This is very good news for rheumatoid arthritis patients, says Eric Matteson, M.D., Mayo Clinic rheumatologist and senior study researcher. Patients with rheumatoid arthritis actually have preserved hearing and are no more susceptible to hearing loss than those who do not have the disease; there is no measurable difference with standard testing. This was surprising. I expected to see more hearing loss in rheumatoid arthritis patients.

The study included 29 patients ages 40 to 69 who had rheumatoid arthritis for more than five years, categorized by decades of age. The researchers compared them to 30 participants of the same gender and age categories who did not have rheumatoid arthritis. All participants had comprehensive hearing tests and questionnaires to measure hearing and dizziness handicaps and assess their overall health. Seventeen of 29 patients with rheumatoid arthritis had abnormal hearing for at least one sound frequency (a measure of pitch), as did 14 of 30 of those without rheumatoid arthritis.

Dr. Matteson notes, however, that the findings do not mean that hearing loss is never related to rheumatoid arthritis. Hearing loss can be a symptom of rheumatoid arthritis, but it doesn't seem to be more of a problem than in the general population, he says.

The researchers found that though no objective difference was detected in comprehensive hearing evaluations of rheumatoid arthritis patients compared to those without the disease, the rheumatoid arthritis patients were more likely to perceive that they had hearing problems. This phenomenon was most pronounced in those who had more severe rheumatoid arthritis and had disabilities due to the disease.

Perhaps this is due to severe disability and thus an overall feeling of helplessness, says Dr. Matteson. People who have profound disability may generalize their disabilities to other areas of the body -- they just feel worse overall.

Among the rheumatoid arthritis patients who had hearing loss, most often the loss was partial and due to nerve problems in the inner ear (sensorineural). The cause of this loss is uncertain, but may be due to factors such as noise exposure according to the researchers. In addition, the hearing loss may be related to an autoimmune attack in which the immune system attacks the cochlea, the inner ear cavity containing hair cells and the nerves which connect the cochlea to the brain. The researchers also noted a possible link between the hearing loss and rheumatoid arthritis medications, as patients who took hydroxychloroquine were somewhat more likely to have hearing problems than other study participants.

Critical next steps in this research, according to Dr. Matteson, are a large study of hearing loss among members of the general population with and without rheumatoid arthritis, in addition to a study to assess the impact of rheumatoid arthritis medications on hearing.

The research team also included Christine Halligan, M.D.; Christopher Bauch, Ph.D.; Robert Brey, Ph.D.; Sara Achenbach and William Bamlet, all of Mayo Clinic.

New vaccine against ear infection

Fri, 03 Mar 2006 12:53:00 PST

( from http://www.rxpgnews.com ) Czech scientists have developed a vaccine to help prevent ear infections in young children.

Next to the common cold, ear infections are the most commonly diagnosed childhood illness. More than three out of four children in the US have at least one ear infection by the time they reach three years of age.

The infection known as acute otitis media could be very painful and - very rarely - cause long term damage.

Roman Prymula, from the University of Defence at Hradec Kralove, Czech Republic, administered almost 5,000 infants with either the ear vaccine or a hepatitis A vaccine at various ages between three and 15 months.

When the researchers followed them up at the age of two, 333 of the children given the new vaccine had a middle ear infection, compared with 499 in the control group, reported the online edition of BBC News.

The vaccine was shown to be effective against disease-causing bacteria.

"We found a reduction in ear, nose and throat specialist-confirmed episodes of acute otitis media by about a third in infants in the vaccine group compared with the control group," Prymula said.

The researchers say the findings are important because both bacterium are significant causes of lower respiratory tract infections.

Novel vaccine effective against middle ear infection in young children

Thu, 02 Mar 2006 05:00:00 PST

( from http://www.rxpgnews.com ) Otitis media (middle ear infection) accounts for nearly 20 million visits to a paediatrician every year in the USA. The bacteria Streptococcus pneumoniae and Haemophilus influenzae are the leading causes of infection. Although vaccines against S. pneumoniae exist, they are not effective enough in the age group where the disease is most prevalent--children younger than two years.

Roman Prymula (University of Defence, Hradec Kralove, Czech Republic) and colleagues tested a vaccine containing proteins from 11 different strains of S. pneumoniae attached to a protein derived from H. influenzae. 4968 infants were randomly assigned to receive the pneumococcal protein D vaccine (intervention group) or hepatitis A vaccine (control group) at the ages of 3, 4, 5 and 12-15 months. The investigators followed up the children at the end of their second year of life and found that there were 333 cases of otitis media in the pneumococcal protein D vaccine group and 499 in the control group. They also found that using the vaccine not only protected against pneumocccal otitis media, but also against middle ear infection caused by H. influenzae.

Dr Prymula states: We found a reduction in ear, nose and throat specialist-confirmed episodes of acute otitis media by about a third in infants in the vaccine group compared with controls.

A novel vaccine could help prevent middle ear infection in children under two years of age, according to a paper in this week's issue of The Lancet.

Otitis media (middle ear infection) accounts for nearly 20 million visits to a paediatrician every year in the USA. The bacteria Streptococcus pneumoniae and Haemophilus influenzae are the leading causes of infection. Although vaccines against S. pneumoniae exist, they are not effective enough in the age group where the disease is most prevalent--children younger than two years.

Roman Prymula (University of Defence, Hradec Kralove, Czech Republic) and colleagues tested a vaccine containing proteins from 11 different strains of S. pneumoniae attached to a protein derived from H. influenzae. 4968 infants were randomly assigned to receive the pneumococcal protein D vaccine (intervention group) or hepatitis A vaccine (control group) at the ages of 3, 4, 5 and 12-15 months. The investigators followed up the children at the end of their second year of life and found that there were 333 cases of otitis media in the pneumococcal protein D vaccine group and 499 in the control group. They also found that using the vaccine not only protected against pneumocccal otitis media, but also against middle ear infection caused by H. influenzae.

Dr Prymula states: We found a reduction in ear, nose and throat specialist-confirmed episodes of acute otitis media by about a third in infants in the vaccine group compared with controls.

Middle cranial fossa approach preserves hearing in acoustic neuroma patients

Tue, 28 Feb 2006 20:58:00 PST

( from http://www.rxpgnews.com ) Even when they're extremely small, tumors on the nerves that connect the brain to the ear can wreak havoc on a person's hearing and balance. But removing them is a delicate process that can, in some cases, cause further harm.

That's why a new study from the University of Michigan Medical School is encouraging. Researchers found high rates of success at preserving patients' hearing when a particular type of procedure was used to remove the tumors, which are known as acoustic neuromas or vestibular schwannomas.

The study, published in the latest issue of the journal Otology & Neurotology, examined the cases of 73 patients with acoustic neuromas who were operated on between 1999 and 2005 using a procedure known as the middle cranial fossa, or MCF, approach. Of the people in the study who had useful hearing before the surgery, about three-quarters retained a level of useful hearing after their tumors were removed.

"Hearing preservation rates have not always been high following the removal of acoustic neuromas," says H. Alexander Arts, M.D., professor of otolaryngology at the U-M Medical School. "The important message with this research is that if you present to us with a small acoustic neuroma, we have a very good chance of preserving your hearing."

The issue of how to preserve the hearing of patients with small acoustic neuromas has become increasingly significant in recent years, with the widespread use of magnetic resonance imaging resulting in the diagnosis of the tumors much earlier than in the past. When very small lesions are detected in people with excellent hearing, Arts notes, hearing conservation is a primary goal of the treatment.

There are several surgical approaches for removing acoustic neuromas. Only two, the MCF approach and the "suboccipital" approach, allow for the possibility of hearing preservation. The suboccipital approach comes from behind the ear, and the MCF approach is from above the ear. Smaller tumors usually can be removed much more easily and with less chance of injury to the hearing nerve using the MCF approach.

Hearing status in the study was classified as A, B, C or D, with Class A being the best. Sixty-two people had Class A or B hearing (referred to in the study as "useful hearing") before the procedure, and of those, 45 people (73 percent) remained in Class A or B afterward. Three people began with Class C, with two of them remaining at that level afterward; eight patients began with Class D hearing, and one of them improved to Class C.

One of the best gauges of success was that a large number of patients with the highest level of hearing did not deteriorate significantly after the procedure. Of the 34 patients who began with Class A hearing, 27 people (80 percent) maintained Class A or B hearing. Ninety-six percent of patients experienced excellent or satisfactory facial nerve outcomes.

Arts notes that previous analyses of hearing preservation have indicated about a 30 percent rate of hearing preservation when techniques other than MCF were used. Since the more widespread use of the MCF approach, and because tumors are now being diagnosed when they are smaller due to more improved MRI imaging techniques, hearing preservation rates have been improving. The results presented in this study represent the highest hearing preservation rates published to date.

In addition to Arts, who also has an appointment in the Department of Neurosurgery, the authors on the paper were Steven A. Telian, M.D., and Hussam El-Kashlan, M.D., of the Department of Otolaryngology at U-M, and B. Gregory Thompson, M.D., of the departments of Neurosurgery and Otolaryngology at U-M.

Stroke patients regain ability to communicate through use of speech generating device

Mon, 20 Feb 2006 05:00:00 PST

( from http://www.rxpgnews.com ) Traditionally aphasic patients have been entitled to a few months of speech rehabilitation during a brief period of so-called spontaneous recovery when the brain physiologically heals itself from injury. But research, using computers to do extended therapy, now indicates that these patients can continue to improve even many years after their stroke or brain trauma. Lingraphicare America, developers of the Lingraphica speech generating device for aphasia, has published results of studies which show significant improvements after use of the device over a period of approximately 20 weeks. Speech generating devices are specialized computers that produce audible speech from words and images.

The Lingraphica uses graphic icons to represent words that a user selects in order to hear them speak. These icons can be combined into phrases or sentences that can then be spoken by the device. Patients use the device to hear and repeat words and phrases for the purpose of practice and therapy, but they also use it to speak for them in order to make their wishes known, for instance to order food or inform a caregiver of a need.

Lingraphicare's data documents that nearly half of the subjects of its study evolved to a less severe diagnostic category of aphasia after use of the device. Over a thousand persons with aphasia were assessed using the standardized assessment instruments, the Western Aphasia Battery (WAB) that measures a patient's level of impairment (for instance how well they can repeat a word or name an object from a line drawing), and the Communication Effectiveness Index (CETI) that measures how well a patient communicates in everyday life out in the community. These assessments were done upon intake and then again at discharge from the study. The patients had mostly been discharged from previous treatment programs after having reached a plateau, and no longer being candidates for further significant gains. Nonetheless, assessments showed that, in the mean, those clients made further significant gains after use of the device, and such gains were found in every diagnostic category of aphasia regardless of severity level or time since the onset of aphasia.

Findings from data analyses have been published in the peer reviewed journals Aphasiology, Stroke, Archives of Physical Medicine and Rehabilitation, and Topics in Geriatric Rehabilitation. (The articles can be printed off of Lingrahicare's website, where charts of the data can also be downloaded.)

The effectiveness of the device can be attributed to several factors. First, as has been documented in stroke rehabilitation research, undamaged parts of the brain will often take over the tasks of damaged areas when a patient engages in daily repeated practice. With a computer, patients can work for hours a day at whatever pace they choose. Second, the Lingraphica uses a technique called projection: when a user clicks on an icon, it quadruples in size. This is designed to put the user in a state of arousal not unlike the fight or flight response caused when a predator approaches, and increases a patient's concentration and involvement. Previous study done by researchers Clifford Nass and Byron Reeves of Stanford have documented the patient's response to this type pf stimulus.

Born with a love of speech

Fri, 17 Feb 2006 05:00:00 PST

( from http://www.rxpgnews.com ) It's well established that neonates have a preference for speech above other sounds, but where does this come from? Is it something that's built in and there's something about the speech signal that they're tuned to listen to without the benefit of experience, or does it come from their prenatal experience in the womb? I think we've shown that there's an experience-independent component to newborns' preference for speech, says Dr. Vouloumanos, an Assistant Professor in McGill's Department of Psychology in Montreal, Canada.

She'll be presenting the findings of her latest research at the annual meeting of the American Association for the Advancement of Science in St. Louis, February 17th.

Neural and cochlear development is such that at about six months gestation the fetus begin to hear a range of frequencies. Thus, there's the possibility that newborns preferentially listen to speech because they're used to it from their in-utero tuning-in.

But, which speech sounds actually get through the uterine sound barrier to the fetus? According to Dr. Vouloumanos, the best evidence indicates that the uterine environment acts as a low-pass filter. This means that only very low, deep sounds those below about 400 Hertz make it to a fetus' ear.

Dr. Vouloumanos and colleagues developed a painstaking two part experimental procedure to separate out possible in-utero exposure from innate predisposition.

At the core of the studies is a unique set of complex speech analogues designed to be as close to speech as possible, without being words. This provided a stringent test for a newborn's ability to distinguish speech from other sounds.

The speech-like sounds, which resemble a chorus of Martians, closely mimic the melodic aspects of speech. They also contain a fundamental frequency the core pitch of a voice, such as baritone or soprano, that helps us clue in to the identity of a voice. These non-speech stimuli were developed by Drs. Sonya Bird and Guy Carden in the Department of Linguistics and Dr. Janet Werker in the Department of Psychology, all at the University of British Columbia, where Dr. Vouloumanos was a doctoral student at the time of research.

In the first stage of the experiments, Dr. Vouloumanos and her colleagues compared the response of 10 to 72-hour-old infants to the speech-like sounds and those of monosyllabic nonsense words, such as lif. When the neonate sucked on a sterilized pacifier, one or the other sound type was played for a one minute interval. The infants were observed for changes in their sucking behaviour.

The neonates changed their behaviour to elicit speech, says Dr. Vouloumanos. What we found is that their sucking behaviour increased to hear speech and it decreased when the sucking would elicit the non-speech sounds.

The study involved 20 neonates at British Columbia's Women's and Children's Hospital. The research, presently in press in the journal Development Science, revealed that the neonates sucked about 15-per cent more in response to the human speech compared with the analogue.

Having demonstrated that newborns could distinguish between these two types of very similar sounds, Dr. Vouloumanos then tested the core question: Had the infants already picked-up an ear for speech in the womb? Could the newborns discriminate between just the low frequency aspects (those that are heard across the womb) of their speech analogue and non-sense words? If they showed a similar preference for the low-frequency non-sense words over the speech analogues it would indicate that they could have developed the preference in their mother's uterus

When Dr. Vouloumanos' tested 16 neonates with just the low frequency sounds the infants showed no preferences.

We established that the low-pass filter signals weren't distinguishable to the neonates. The low frequency sounds that we used in our study didn't have enough information for the neonates to tell them apart, says Dr. Vouloumanos of the unpublished results. From that I conclude tentatively that this preference for speech that we observe might be independent of prenatal experience. It's something that's more built-in.

As excited as she is about the results, Dr. Vouloumanos, says that the findings raise as many questions as they answer. Given the similarity between the speech and speech analogues, the $64, 000 question is what is exactly about speech to which newborns are so drawn?

Says Dr. Vouloumanos: There's something about speech that infants will orient towards, but we don't yet know what it is. What are the aspects of the speech stimulus have we taken away in making our non-speech sounds?

Aldosterone linked to good hearing as we age

Sun, 12 Feb 2006 18:38:00 PST

( from http://www.rxpgnews.com ) Researchers have linked a hormone known to adjust levels of key brain chemicals to the quality of our hearing as we age. The more of the hormone that older people have in their bloodstream, the better their hearing is, and the less of the hormone, the worse their hearing is.

The hormone, aldosterone, is known to regulate kidney function and also plays a role in controlling levels of two crucial signaling chemicals in the nervous system, potassium and sodium. For nerves to send signals crisply and work properly, potassium and sodium must be in precise proportion, without any disruption in the molecular channels or gates through which they move. Levels of potassium are particularly crucial in the sensitive inner ear, where fluid rich in potassium plays a central role in converting sounds into signals that the nervous system recognizes.

The team of scientists in Rochester, N.Y., put 47 healthy men and women between the ages of 58 and 84 through a battery of sophisticated hearing tests. Scientists also measured their blood levels of aldosterone, which is known to drop as people age. They found that people with severe hearing loss had on average about half as much aldosterone in their bloodstream as their counterparts with normal hearing. The researchers noted, however, that the levels of aldosterone found in all the participants is considered normal, and that no patients or physicians should consider altering aldosterone levels without more research.

The findings come from researchers at the International Center for Hearing and Speech Research (ICHSR), a group funded by the National Institute on Aging that is recognized as a leader in research on age-related hearing loss. The center includes scientists from the National Technical Institute for the Deaf at Rochester Institute of Technology and neuroscientists from the University of Rochester.

"The inner ear is especially sensitive to any disruption in potassium levels," said Robert D. Frisina, Ph.D., professor of Otolaryngology at the University of Rochester Medical Center and an adjunct professor at Rochester Institute of Technology. "We know that potassium levels in the inner ear seem to decrease as we age and that these falling levels play a role in age-related hearing loss, and we also know that blood levels of aldosterone generally decrease with age.

"We found a direct link between blood levels of aldosterone and the ability of people to hear normally as they age. Depressed hormone levels may hurt hearing both in the inner ear and the part of the brain used for hearing. More research is needed, however, to understand the precise role that aldosterone plays â for instance, whether it's a cause of failed hearing, or whether it's symptomatic. Before we understand the issue more fully, people should not worry about their aldosterone levels or look to boost the amount in their bloodstream."

The team led by Frisina published its results in the November issue of the journal Hearing Research. This week at the annual international meeting of the Association for Research in Otolaryngology in Baltimore, the team presented its latest results showing just how important potassium regulation is to age-related hearing loss.

In Baltimore, Otolaryngology medical resident Jared Spencer, M.D., presented results from "knockout" mice whose genes controlling the potassium channels in the inner ear don't function properly, and confirmed that malfunctioning potassium channels are central to age-related hearing loss, or presbycusis. The channels are highly concentrated in a part of the brain that plays an important role providing feedback from the brain to the ears. Frisina's team previously discovered that the feedback system is one of the first things to go wrong in age-related hearing loss, often declining in people who are in their 40s and 50s, usually before they even realize their hearing is declining.

"We are now working out some of the underlying biology about how the decline occurs," said Frisina. "We have evidence that these potassium channels may play an important role in the failure of the feedback system, which is a big part of age-related hearing loss."

Nearly everyone wrestles with failing hearing at some point. While some people suffer from hearing damage as a result of exposure to loud noise, or from other causes such as the side effects of some medications, for many people hearing problems occur with no known cause. Some people notice problems in their 40s and 50s, but the process becomes very noticeable for most people in their 60s and older.

Frisina said that until the biology of the problem is better understood, the best advice for people concerned about hearing loss is to limit exposure to loud, damaging noise and to medications that are toxic to the ears. He also counsels people to eat healthy and to exercise â "all those things you know you should be doing to stay healthy with age," he said.

Meanwhile, his team is looking at the possibility of using gene therapy to try to correct the problem. It may be possible some day to modify a person's inner ear to correct the potassium imbalance that is central to hearing loss. Such an approach might also address the biggest cause of congenital deafness, which involves a genetic mutation that mucks up the potassium balance in the inner ear.

Chance, music, and the ear of the beholder

Mon, 06 Feb 2006 05:00:00 PST

( from http://www.rxpgnews.com ) The work is reported by a team of scientists led by Dr. Jan Schnupp at the Oxford University Auditory Neuroscience group.

The world we inhabit is constantly subjected to countless random influences that may occasionally conspire to bring about large and abrupt changes in our environment, but that more often will cancel each other out, and thus provoke only little or no change. Imagine a boy playing a game where, on every round, he tosses twenty coins, and for every head he will take a step to the left, while for every tail he will take a step to the right. In most rounds, the number of heads will be very similar to that of the tails, and the boy's net position will change only a little, but occasionally it might be almost all heads or all tails and the boy will make a sudden large leap to the left or right. Many things in nature are pushed around, much like the boy in this game, by a combination of random influences, from dust grains in a drop of water pushed about by the collision with water molecules to flocks of animals roaming across a pasture. Scientists would say that their movement is approximately 1/f-distributed, which means simply that there is an inverse relationship between the size of a change and the likelihood of a change. Small changes occur often (at a large frequency), while large, abrupt changes occur with a proportionately smaller frequency.

In the 1970s, the American scientists Voss and Clarke noticed that even music, speech, and natural soundscapes appear to behave according to the 1/f rule. Large, abrupt changes in loudness or in musical pitch are proportionally less frequent than small, gradual ones, and when human volunteers are asked to rate computer-generated random melodies, they instinctively prefer those melodies that obey the 1/f rule to those that do not. Melodies that change more abruptly than the 1/f rule would sound unpleasantly erratic. In contrast, melodies that change more slowly sound boring.

Now, in the new study, the researchers have discovered that this preference for 1/f-distributed soundscapes appears to be hard-wired into the mammalian brain. Individual neurons in the auditory cortex of ferrets were found to respond more strongly and more reproducibly to stimuli with random pitch and loudness fluctuations that conformed to the 1/f rule than to other stimuli that did not. This selective sensitivity results in a more accurate representation of the 1/f-distributed sounds within the brain. 1/f-distributed behavior has a strong random element, but is nevertheless not entirely unpredictable, and it appears that our sensory systems have evolved to expect this partial predictability as natural, and to exploit it to become particularly efficient at processing sensory inputs that exhibit just the right amount of randomness.

New route to therapy for Rett syndrome?

Wed, 01 Feb 2006 05:00:00 PST

( from http://www.rxpgnews.com ) Rett syndrome is the most common form of mental retardation in girls, affecting about one in 10,000. The X-linked disorder is particularly devastating, because while children with the disease are normal as infants, when they become toddlers they suffer a dramatic decline in physical and mental abilities. They experience language and growth retardation, breathing problems, seizures, motor dysfunction, hand-wringing, and social impairment.

The primary cause of Rett syndrome is a mutation in the gene for MECP2, or methyl-CpG binding protein 2. In their study, Jaenisch and his colleagues explored how this mutation might affect the activity of another gene, called Bdnf. This gene is known to produce the neurotrophic factor BDNF that is essential for neuronal survival and the adaptability, or plasticity, of connections among neurons. Bdnf had been known to be a target of control by MeCP2, but researchers did not know whether it played a significant role in the disease pathology.

In their studies of mice lacking the Mecp2 gene, Jaenisch and his colleagues found that the animals showed lower levels of BDNF. They also found that knocking out BDNF in normal mice produced some of the same Rett syndrome-like symptoms as mice lacking Mecp2. Knocking out both genes in the mice seemed to produce some additive effects, they found. Such mice died earlier than mice lacking only Mecp2 and showed more lethargy.

A key discovery came, however, when the researchers produced mice that lacked Mecp2 but had higher levels of BDNF. Such mice showed an increased lifespan compared to Mepc2-deficient mice, enhanced brain activity, increased locomotor activity, and some increase in brain weight.

The researchers concluded that these findings demonstrate a functional interaction between these two genes. They theorized, however, that the interaction was indirect: Given that BDNF expression depends on neuronal activity, we favor the hypothesis that Mecp2 deficiency reduces neuronal activity, thereby indirectly causing a decreased BDNF protein level, they wrote.

The latest findings of BDNF involvement in Rett syndrome add to the diseases linked to abnormal BDNF expression--which is also found in Huntington's disease, schizophrenia, and depression--noted the researchers.

Our findings provide in vivo evidence of a functional interaction between Mecp2 and Bdnf, concluded the researchers. Furthermore, our results indicate that manipulating the BDNF level or the BDNF signaling pathways may present therapeutic opportunities for [Rett syndrome] patients.

They also wrote that Although BDNF is only one of many genes regulated by MeCP2, it is the first one shown to modulate disease progression of Mecp2 mutant mice.

Online ear and hearing diagnosis to break sound barrier

Wed, 25 Jan 2006 05:00:00 PST

( from http://www.rxpgnews.com ) The unique software which is expected to be available for doctors in 12 months' time will be a collection of ear and hearing diagnoses and associated symptoms collated from reports published by medical experts in international scientific and medical articles, reports and journals.

The software will use statistics from a database of medical reports to present a list of potential symptoms for a general practitioner, as they are selected, with the program suggesting the most likely diagnosis and is expected to benefit doctors based in regional locations.

One of Australia's leading ear surgeons and Director of the Lions Ear and Hearing Institute (LEHI), Professor Marcus Atlas, congratulated the Institute's Senior Scientist, Dr Rob Eikelboom, for heading the research lead to the signing of a memorandum of understanding to develop the program with technology start-up, Paradigm Diagnostics.

We are pleased to have signed a commercial agreement with Paradigm Diagnostics and we hope to finalise a licensing agreement shortly to advance this exciting technology, Professor Atlas said.The new decision support system ties in with our telemedicine program which is close to reaching commercialisation. (Ear telemedicine is a relatively new technology that enables patients with ear disease and hearing impairments to access ear specialists).

We are not suggesting that doctors will be eventually replaced by computers as a result of this breakthrough in patient diagnosis, he said.

What we are saying is that the software will enable a general practitioner to more easily diagnose an ear and hearing condition particularly if they are unsure of a patient's symptom, or have difficulty contacting a skilled ear specialist.We look forward to finalising the software because it will be an extremely valuable tool for particularly for general practitioners and health workers located anywhere, as well as trainee ear and hearing specialists, Professor Atlas said.

Professor Atlas said the computer-aided tool would also play an important role supporting the Lions Ear and Hearing Institute's ear tele-health system, which uses technologies to improve access to ear specialists to reduce ear diseases.

Professor Stuart Bunt, head of Paradigm Diagnostics, has been developing the diagnosis software technology at the University of Western Australia for the last 10 years.

Professor Bunt said medical practitioners would benefit from the diagnosis software, which would also suggest symptoms to check or tests to perform.

It really will be an innovative product that will speed up the diagnosis process for practitioners, Professor Bunt said.

Paradigm Diagnostics looks forward to advancing this revolutionary diagnosis technology with the Lions Ear and Hearing Institute.

Professor Bunt also said the software would provide medical background information, photos, video and references to assist with diagnosing patients.

Paradigm Diagnostics recently developed similar software programs for hazardous chemicals and is currently developing other diagnosis programs for corneal disease and sexually transmitted diseases.

Almost 2.5 million people in Australia are affected by hearing loss, with tens of thousands of children and adults currently suffering from ear disease.

Antibiotic telithromycin linked to liver damage

Sun, 22 Jan 2006 14:18:00 PST

( from http://www.rxpgnews.com ) An antibiotic drug to treat lung and sinus infections has been found to cause liver failure, according to a report.

Doctors at the Carolinas Medical Center in Charlotte, North Carolina, studied three patients who were administered the drug 'Ketek' and found liver failure in them, a report published in the journal Annals of Internal Medicine says.

All three cases occurred within a few months of each other last year, said report co-author John Hanson, a liver transplant doctor at the medical centre.

'Ketek' is prescribed to treat lung and sinus infections. The antibiotic also led to the death of a 26-year-old man and transplant surgery for a 51-year-old woman, it reported.

Ketek was approved by the US Food and Drug Administration in 2004. Doctors have sent their findings to the FDA and discussed them with Sanofi-Aventis SA, which makes Ketek.

The company is currently reviewing the data, the report said.

Salicylate causes tympanic membranes to rupture more easily

Mon, 26 Sep 2005 15:51:00 PST

( from http://www.rxpgnews.com ) It's well known that high doses of aspirin can cause ulcers and temporary deafness, but the biochemical mechanism responsible for these phenomena has never been deciphered. New research from Rice University offers clues, showing for the first time how salicylate -- an active metabolite of aspirin -- weakens lipid membranes. Researchers believe these mechanical changes disrupt the lining of the stomach, which functions to protect underlying tissue from the acidic contents of the gut. By a similar mechanism, the changes may result in aspirin-related deafness by interfering with the proper function of prestin, a transmembrane protein that's critical for mammalian hearing.

The study appears in the September issue of Biophysical Journal.

"Our studies found that membranes exposed to physiological concentrations of salicylate were thinner, more permeable, easier to bend and more likely to rupture," said study co-author Robert Raphael, the T.N. Law Assistant Professor of Bioengineering.

All cells are surrounded by membranes, ultrathin barriers of fatty acids that are just a few nanometers thick. Membranes act like a skin, sealing off the inner machinery of the cell from the outside world. About 40 percent of human proteins are "transmembrane" proteins, molecules that stick through the membrane like a needle through a cloth.

First identified five years ago, prestin is a transmembrane protein found in the inner ear. A motor protein, prestin is thought to act like a piezocrystal, converting electrical signals into mechanical motion. In the outer hair cells of the cochlea, prestin acts as a molecular motor, causing the cells to move rhythmically and amplify the sounds we hear.

"If you change the mechanical properties of the membrane, you will likely affect the biophysical processes that take place there, including those that are mediated by membrane proteins like prestin," Raphael said.

Raphael's findings also provide a mechanistic basis for the observations of Texas Medical Center researchers, who have found that the debilitating and dangerous gastrointestinal side-effects of anti-inflammatory drugs like aspirin and ibuprofen are independent of biochemical signaling cascades mediated by cyclo-oxygenase (COX). Raphael's research was co-sponored by the Texas Technology Development and Transfer Program and PLX Pharma, a Houston-based startup that began the final phase of clinical trials for its reformulated version of ibuprofen last December.

"Effectively, our results proved that salicylate can stabilize holes that spontaneously form in lipid membranes, thus increasing membrane permeability", Raphael said. "Our study highlights the pivotal role played by the mechanical properties of membranes in biological processes."

In their experiments, Raphael and graduate student Yong Zhou, the first author of the study, used a technique called micropipette aspiration. Working with needle-like glass capillary tubes, Zhou measured the mechanical properties of phospholipid membranes, which are very similar to those of live cells.

Raphael credited Zhou's initiative in applying new technology to the problem.

"Yong was the driving force for introducing the new technique of dynamic tension spectroscopy into my laboratory," Raphael said. "This enabled us to really get insight into the subtle details associated with the mechanism by which salicyalte affects membrane stability."

Zhou was recently awarded a Student Research Fellowship award from the American Gastroenterological Association to conduct studies on another salicylate-like molecule.

Amount of hearing in an ear prior to surgery is unrelated to a patient's ability to interpret speech using an implant

Sun, 04 Sep 2005 08:08:00 PST

( from http://www.rxpgnews.com ) Hearing-impaired individuals with severe to profound hearing loss and poor speech understanding who possess some residual hearing in one ear may experience significant communication benefit from a cochlear implant even if it is placed in the worse-hearing ear, a Johns Hopkins study suggests.

There is growing evidence that the amount of hearing in an ear prior to surgery is unrelated to a patient's ability to interpret speech using an implant, says Howard W. Francis, M.D., lead author of the study and an associate professor of otolaryngology-head and neck surgery. Therefore, the better-hearing ear could be saved for the continued use of a hearing aid or future technology to complement a cochlear implant, Francis says.

Reporting in the August issue of the journal Ear and Hearing, Francis and colleagues compared patients with no residual hearing, patients with some residual hearing in one ear and patients with some residual hearing in both ears. The patients' ability to interpret sounds and speech was measured before and after cochlear implant surgery.

Patients with residual hearing in one or both ears prior to surgery scored significantly higher on the speech perception tests following surgery, even when the implanted ear was profoundly deaf prior to surgery. The researchers also noted that patients' ability to interpret speech in a noisy environment increased dramatically over time in proportion with the amount of residual hearing in the non-implanted ear.

"In cases where even a small amount of hearing ability remains in one ear, the central nervous system is better able to integrate auditory information with a cochlear implant, and equally so from either ear," Francis says. "This speaks to the brain's circuitry and its ability to interpret electrical signals generated by the implant even in the presumably more degenerated ear."

How sensory hair cells in the ear develop unique shapes that enable sound perception

Fri, 19 Aug 2005 22:37:00 PST

( from http://www.rxpgnews.com ) Scientists are one step closer to understanding the genetic pathway involved in the development of hearing. New research findings, published online this week in the journal Nature Genetics, detail how sensory hair cells in the ear the cells largely responsible for hearing develop unique shapes that enable the perception of sound.

Located in the spiraled cochlea, the hearing portion of the inner ear, the hair cells transform the mechanical vibrations that enter the ear in the form of sound waves into chemical signals, which they then direct to the brain. Ping Chen, PhD, assistant professor of cell biology at Emory University School of Medicine, and her colleagues found that the development of cochlea and hair cells is dependent on a genetic pathway called the PCP (planar cell polarity) pathway.

Although some species, including birds, are capable of re-growing hair cells, mammals lack the ability to naturally regenerate hair cells. Thus individuals born with improperly developed hair cells, or those who lose them through trauma, disease, environmental factors or aging, cannot regain their hearing. Reports from the National Institutes of Health (NIH) indicate that severe hearing impairment affects 28 million Americans. That number includes the approximately 4,000 Americans each year who suffer from sudden deafness, and the roughly 12,000 children born each year with difficulty hearing.

Scientists have been optimistic that by discovering the genes involved in development of the ear they could learn the molecular and genetic basis for some forms of deafness and offer promises for future efforts in hearing restoration. For the past two decades they have understood that the unique asymmetrical shape of hair cells was an essential part of their proper function. However, it was not clear which genes were involved in the development of this polarized shape within the cochlea. By using mouse models, Dr. Chen and her research team discovered that the PCP pathway is involved in shaping the cochlea and the sensory hair cells. Mutations within this genetic pathway impact the shape of the cochlea and the polarity of the sensory hair cells that are essential for hearing.

"This basic molecular pathway is involved in regulating many other aspects of embryonic development in addition to the formation of the polarized structure of the auditory sensory organ," says Dr. Chen. "Finding out which processes are involved in the formation of these polarized cells is an essential, fundamental issue for both developmental and cell biologists."

Tonsillar homing of Epstein-Barr virus-specific CD8 T cells

Fri, 19 Aug 2005 13:54:00 PST

( from http://www.rxpgnews.com ) In a study appearing online on August 18 in advance of print publication of the September 1 issue of the Journal of Clinical Investigation, Alan Rickinson and colleagues from University of Birmingham address the immunology of long-term oropharyngeal shedding of Epstein-Barr virus at a time when infection of circulating lymphocytes is well-controlled.

The authors used three groups of patients at different stages of infection, representing different positions of the virus-host balance: acute infectious mononucleosis (IM) patients undergoing primary infection, post-IM patients shortly after resolution of acute infection, and long-term asymptomatic virus carriers.

During the acute disease and shortly after its resolution, CD8+ T cells specific for virus replicative epitopes are not efficiently targeted to oropharyngeal sites of viral replication, coincident with prolonged viral shedding from these sites.

By contrast, responses to virus latent cycle epitopes begin to accumulate more quickly in the tonsil post-IM and the latent infection is more rapidly controlled. In long-term virus carriers where both lytic and latent infections have been reduced to very low levels, both types of virus-specific response are dramatically enriched in tonsils compared to blood.

Indeed, in healthy asymptomatic carriers total reactivities to defined EBV epitopes can account for up to 20% of the entire tonsillar CD8 population. The data suggest that efficient control of EBV infection requires appropriate CD8 T cell homing to oropharyngeal sites.

Chronic sinus infection is not a tissue issue

Sun, 31 Jul 2005 14:09:00 PST

( from http://www.rxpgnews.com ) Mayo Clinic researchers have found that the cause of chronic sinus infections lies in the nasal mucus -- the snot -- not in the nasal and sinus tissue targeted by standard treatment. The findings will be published in the August issue of Journal of Allergy and Clinical Immunology and are available online at http://www.us.elsevierhealth.com/jaci.

"This strikingly teaches against what has been thought worldwide about the origin of chronic sinus infection: that inflammatory cells break down, releasing toxic proteins into the diseased airway tissue," says lead researcher and Mayo Clinic ear, nose and throat specialist Jens Ponikau, M.D. "Instead we found that these toxic proteins are released into the mucus, and not in the tissue. Therefore, scientists might need to take not only the tissue but also the mucus into account when trying to understand what causes chronic sinus infections and probably other airway diseases."

The findings could significantly change the way chronic sinus infection is treated, according to Dr. Ponikau.

"This has far-reaching implications," says Dr. Ponikau. "This suggests a beneficial effect in treatments that target primarily the underlying and presumably damage-inflicting nasal and sinus membrane inflammation, instead of the secondary bacterial infection that has been the primary target of treatments for the disease. Also, some surgeons have already started to change the way they do surgery for patients with chronic sinus infections, focusing now on removing the mucus, which is loaded with toxins from the inflammatory cells, rather than the tissue during surgery. Leaving the mucus behind might predispose patients for early recurrence of the chronic sinus infection."

Dr. Ponikau conducted this research along with Hirohito Kita, M.D., and Gail Kephart, Mayo Clinic allergic diseases researchers. David Sherris, M.D., and Eugene Kern, M.D., both former Mayo Clinic ear, nose and throat specialists who now work at the University at Buffalo, also participated in the project.

The team found that in chronic sinus infection patients, activated white blood cells (eosinophils) cluster in the nasal and sinus mucus and scatter a toxic protein (major basic protein) onto the nasal and sinus membrane. While major basic protein was not distributed in the nasal and sinus tissue, the level of this protein in the mucus of chronic sinus infection patients far exceeded that needed to damage the nasal and sinus membranes and make them more susceptible to infections such as chronic sinus infection.

To conduct this investigation, Dr. Ponikau and fellow researchers collected specimens from 22 consecutive Mayo Clinic chronic sinus infection patients undergoing endoscopic sinus surgery. The surgeons extracted the maximum possible tissue and mucus during the sinus surgery. The surgeons also extracted tissue and mucus from healthy patients undergoing septoplasty, surgery to fix a deviated septum, for comparison with the specimens from the chronic sinus infection patients. Through various forms of laboratory examination of the tissue and attached mucus, the investigators observed an abundance of major basic protein throughout the nasal and sinus mucus in all 22 specimens, but not in the tissue.

Chronic sinus infection is one of the most common chronic diseases in the United States, affecting 32 million adults, according to the National Center of Health Statistics. Chronic sinus infection produces nose and sinus problems characterized by stuffy nose, loss of sense of smell, postnasal drip, nasal discharge, and head and face pain lasting three months or longer. It notably decreases the quality of patients' lives, impairing physical and social functioning, vitality and general health, according to the Mayo Clinic researchers.

Extracorporeal septoplasty for difficult nasal reconstructive surgery

Tue, 19 Jul 2005 03:05:00 PST

( from http://www.rxpgnews.com ) A surgical technique that requires the removal, restructure and re-implantation of the nasal septum (the partition of the nose between the nostrils) appears to be a useful option for repairing the hard-to-treat severely deviated septum, according to an article in the July/August issue of the Archives of Facial Plastic Surgery, one of the JAMA/Archives journals.

Severe nasal septal deviations, usually the result of trauma, previous surgery or congenital malformations such as cleft palate, pose a particular challenge to plastic surgeons, according to background information in the article. The nasal septum affects both the appearance and the airway passages of the nose. Usual plastic surgical techniques often prove insufficient for reliably correcting severe septal deformities, the author suggests, necessitating the complete removal and correction of the septum to achieve good functional and aesthetic results.

Wolfgang Gubisch, M.D., of Marienhospital, Stuttgart, Germany, reviewed the medical charts of patients undergoing septoplasty (surgery of the nasal septum), either performed by him or under his supervision, at a facial plastic surgery center. Of the 2,119 patients from 1981 to 2004 with severe nasal septal deviations undergoing the surgery developed and refined by Dr. Gubisch, the charts of two groups were reviewed: 459 procedures performed by Dr. Gubisch from January 1, 1981 through July 31, 1987 and 108 patients whose procedures were supervised by Dr. Gubisch in 1996.

In the first group of patients, "Based on the subjective opinion of the surgeon and patients and the findings of the clinical examinations, a good to excellent functional result was obtained in 96 percent," the author writes. "Despite the complex deformity and complicated operative procedure, postoperative complications were rare and only 20 patients (four percent) elected to have revision septoplasty. Fifty-seven complications (12 percent) occurred, with the most common complaint being irregular contour of the dorsum [the bridge of the nose] (32 patients, seven percent)." In the supervised procedures, there were 14 postoperative complications (13 percent) and 12 dorsal (bridge of the nose) irregularities (11 percent). Eight patients (7 percent) chose to redo surgery.

"This vast experience of extracorporeal septoplasty [removal of the septum from the nose for repair] in 2,119 patients spanning 20 years demonstrates that it is an important technique in the armamentariam (armory of techniques) of surgeons for correcting of extensive nasal septal deviations that result from trauma, previous surgery, or congenital anomalies," the author concludes. "During the study period, the technique was improved to make it safe and practical for all surgeons dealing with this difficult problem."

Cidofovir as an Useful Adjunct in Treating Recurrent Respiratory Papillomatosis

Mon, 30 May 2005 20:57:00 PST

( from http://www.rxpgnews.com ) Recurrent Respiratory Papillomatosis (RRP) is a chronic disease evidenced by wart-like lesions in the larynx, particularly on the vocal folds. Debulking or removing a major part of the lesions is generally the treatment of choice in order to preserve as much laryngeal function as possible and limit the morbidity associated with surgical treatment of this generally benign disorder.

The papillomas cause hoarseness, and if left untreated can grow large enough to obstruct the airway and cause death. Some patients (6-17 percent) develop spread of the papillomas into the trachea, bronchi, or even the pulmonary parenchyma. On rare occasions the papilloma may undergo malignant transformation.

A majority of the patients afflicted with this disease are children, and the papillomas often demonstrate a more aggressive behavior in children. Recurrence is the norm, with the average child undergoing 10 surgeries in their lifetime, and seven percent undergoing over 100 surgeries. There are great financial costs of treating this chronic disease with estimates of direct lifetime medical costs of treating a single person with RRP reaching $200,000.

The human papilloma virus ( HPV ) 6 and 11 causes the disease is usually caused by. Human papillomaviruses ( HPVs ) are small, double-stranded DNA viruses that infect strictly squamous epithelial tissues and induce hyperproliferative lesions.

Cidofivir is an acyclic nucleoside phosphonate HPMPC [( S )-1-( 3-hydroxy-2-phosphonylmethoxypropyl )cytosine]. It has proved to be effective in vitro and in vivo against a wide variety of DNA virus and RNA retrovirus infections. Cidofovir is activated by multi-step phosphorylation.

The long-lasting antiviral effect of cidofovir allows infrequent dosing of the drug ( i.e., only once a week or every other week ), which clearly distinguishes cidofovir from other antiviral drugs ( acyclovir, penciclovir, and ganciclovir ), which have to be administered several times daily to sustain an antiviral response.

Complete remissions of papillomatous lesions have been achieved following either topical gel application or direct intralesional injections of cidofovir. The potential of cidofovir to treat laryngeal papillomatosis has also been demonstrated by studies in which patients with severe recurrent laryngeal papillomatosis, treated with intralesional injections of cidofovir resulted in a complete regression of the papillomatous lesions in the majority of the patients.

Although response to cidofovir is not universal, long-term follow-up of patients treated with cidofovir have demonstrated its usefulness as an adjunct in treating RRP.

Serial analysis of gene expressions ( SAGE ) was developed in 1995 as an open system technique for probing the expressed genome. As such, it identifies cellular transcripts without relying on known genes for detection. SAGE allows detailed qualitative and quantitative analysis of large numbers of cellular transcripts. A new study uses SAGE to study gene expression of papilloma cells before and after the administration of the anti-viral adjuvant cidofovir. The researchers hypothesize that there is a differential gene expression in the papilloma after treatment with cidofovir. This differential expression may help better understand the intracellular effects of cidofovir, and more importantly, potential genetic alterations that occur with antiviral therapy in general.

Methodology:

Papilloma samples were obtained from one patient during regularly schedule RRP débridements. During the first tissue harvest, samples were taken, after which cidofovir was injected into the base of the lesions. Two months later, the patients were taken back to the OR and samples were again harvested.

SAGE library was constructed using the I-SAGE kit from Invitrogen; total RNA was isolated from a patient sample using Trizol reagent. RNA integrity was tested prior to use by gel electrophoresis. NlaIII ( restriction site 5'-CATG-3' ) was used as the anchoring enzyme and BsmFI ( Type IIS restriction site ) as the tagging enzyme.

Sequence files were first analyzed with PHRED base-calling software to determine the accuracy of the sequencing run. A minimum PHRED score of 20 was used to filter out tags with a higher probability of sequencing error. This data was imported into eSAGE which also excludes tags of unexpected larger or smaller size to ensure the analysis of valid tags. The program then filters out duplicate dimers ( ditags with the same two tags ) as this suggests non-random ligation and a non-quantitative library.

Results:

Over 19,000 tags were found in each of the libraries, with 7,993 unique transcripts identified in the pre-treatment and 6,749 identified in the post-cidofovir library. A total of 997 transcripts were found in both libraries. Following cidofovir treatment, the greatest up-regulation was in gene families associated with cell proliferation, metabolism, transport and response to biotic stimuli. Post-treatment up-regulation was seen in numerous specific genes, such as Interferon Regulatory Factor, which has been associated with virus-host interactions, passive viral induction of host immune response, and response to DNA damage stimulus. Down-regulation was demonstrated in gene families associated with transcription, regulation of nucleic acid metabolism, and signal transduction.

Conclusions:

The researchers demonstrated a long list of genes that are expressed in RRP using the SAGE technique. More importantly, they have demonstrated how the expression of various gene families changes when exposed to the anti-viral drug cidofovir. Additionally, identification of more than 1400 unique transcripts was achieved that may help with new gene discovery and better understanding of the response to cidofovir and other anti-viral drugs on a genetic and molecular level.

Adenotonsillectomy Improves Asthma in Children

Mon, 30 May 2005 20:41:00 PST

( from http://www.rxpgnews.com ) Asthma or reactive airway disease is a chronic inflammatory disease that causes hypersensitivity of the airways. Hypersensitive airways result from too many stimuli, triggering narrowing and/or obstruction of the airways. This narrowing is caused by airway inflammation, often mediated by cellular elements such as mast cells, eosinophils, T-lymphocytes, alveolar macrophages, neutrophils and epithelial cells. During an asthmatic response, sufferers experience epithelial damage, excessive airway fluid, mucous hyper secretion and hyper responsiveness of bronchial smooth muscle causing difficulty in airflow in and out of the lungs.

Past research has found that improvement of upper airway disease ( i.e. tonsillitis, sinusitis, nasal congestion ) positively impacts lower airway disease. Adult asthmatics who have undergone endoscopic sinus surgery have been shown to have improvement in their sinus disease and a decrease in their medication requirements. Cystic fibrosis patients who are candidates for lung transplantation are generally recommended to undergo sinus surgery prior to transplantation surgery. Several small studies seem to suggest that tonsillectomy and adenoidectomy may decrease asthma severity in patients postoperatively.

A new study suggests that an adenotonsillectomy, which provides improvement in the upper airway of children, may in turn lead to improvement of the lower airways of children, especially those with bronchial asthma.

One explanation for improvement observed in these children postoperatively is that there is a decreased irritation to the bronchial system.

This occurs as a result of the decreased microaspiration of infectious secretions, which when present in the tracheobronchial tree may exacerbate asthma. In other words, removing the adenoids and tonsils causes a decrease in the amount of mucopurulent drainage from the upper airways which subsequently seed and irritate the lower airways. This study will examine the effect of adenotonsillectomy on reducing the impact of asthma on children and their families.

Methods:

A retrospective review was conducted of patients that underwent adenoidectomy and/or tonsillectomy within the last five years and carried a diagnosis of asthma. These charts were reviewed to glean demographic information on the patient in order to conduct caregiver interviews. Eighty seven charts were identified for review, 33 were excluded because parents could not be contacted, and 16 were excluded for comorbidities, such as cystic fibrosis, immunologic deficiencies, severe gastroesophageal reflux, etc. which left 38 patients for evaluation.

Patients were included in the study if they had undergone adenoidectomy and/or tonsillectomy within the last five years, and carried a diagnosis of asthma without a significant co-morbidity. Indications for surgery included obstructive sleep apnea, chronic tonsillitis, chronic sinusitis, or other related disorders. Both cold-knife and electrocautery techniques of tonsillectomy were included and adenoidectomies performed by both curettage and cautery were included. Asthma was diagnosed by a primary care physician or a pediatric pulmonologist.

A questionnaire was designed for caregivers to assess pre and post operative signs and symptoms of asthma in the patient. The parent was asked to answer the same set of questions for before surgery and after surgery. The survey was given no less than six months after surgery and no more than five years after surgery.

The mean age of the 38 patients included in the study was 5.4 years, ranging from 2 to 12 years. The male to female ratio was 1.92 ( 25 males, 13 females ). The mean post operative follow up period was 1.5 years, ranging from seven months to four years. Eight patients ( 21 percent ) underwent adenoidectomy alone, and 30 patients ( 79 percent ) underwent adenotonsillectomy. Key findings included:

* Medication use dropped greatly after surgery. Use of inhaled steroids decreased from 26 patients ( 68 percent ) to 17 patients ( 45 percent ), and Albuterol use decreased from 34 patients ( 89 percent ) to 18 patients ( 47 percent ). Use of long acting beta2-agonists decreased from four patients ( 10 percent ) to zero patients, and use of leukotriene moderators dropped from 12 patients ( 31 percent ) to 11 patients ( 28 percent ).

* Before surgery, 19 patients ( 50 percent ) had used systemic steroids at least once per year. After surgery, only seven patients ( 18 percent ) used systemic steroids.

* A decrease in severity of asthma was also observed. The average asthma severity score decreased from 2.12 preoperatively to 0.74 postoperatively.

* Of the children who attended school, the average number of missed school days/year decreased from 7.76 to 3.28; the average number of missed work days/year for working parents decreased from 7.35 to 1.8.

Despite the small number of subjects, the study revealed clear improvement of asthma symptoms for patients who had an adenotonsillectomy performed.

Spatial Hearing Aid Can Provide Direction of Sound

Thu, 28 Apr 2005 18:11:00 PST

( from http://www.rxpgnews.com ) Over three million Australians suffer from hearing loss but fewer than 20 per cent of them use hearing aids. Part of the problem is that technology just isn't good enough for them. Researchers from Sydney are changing that.

They've developed a more effective way of solving the biggest problem of the hearing impaired-how to carry on a conversation with more than one person or in a noisy environment. The result is a spatial hearing aid which provides the listener with direction as well as sound. It is now undergoing clinical trials in Sydney. If it passes the trials it could be on the market in three years.

The Spatial Hearing Aid aims to enable normal segregation of speech, and to provide a significant increase in speech intelligibility. The device should allow users to regain their ability to participate fully in their family, social and business lives.

"We humans naturally use our brains to sort out what sounds we want to pay attention to. The Spatial Hearing Aid provides spatial cues to help the hearing-impaired do this, without arbitrarily deciding which sounds are important," says Fresh innovator Dr Craig Jin, Senior Lecturer in the School of Electrical and Information Engineering at the University of Sydney and lead researcher on the project. "This is markedly different to the current industry trend which focuses on allowing the technology built into the hearing-aid to decide which sounds are important."

Up to 22 per cent of Australians suffer some sort of hearing impairment and, in people over 70, this rises to almost three out of four.

The costs in lost productivity, special education and medical care from untreated hearing impairment in the US are estimated at US$56 billion a year and growing. The Hearing Aid industry is worth about US$6 billion, with about 5.5 million units sold each year.

"Our research used a unique approach," Jin says. "We have simulated hearing-impaired listening in ourselves so that we really understand the issues confronting our end users. We aren't simply developing another hearing aid. Through our research we are examining how best to solve some of the most pressing problems facing hearing aid wearers in a new way."

"In addition, we are testing the Spatial Hearing Aid in a range of potential users to demonstrate the real world benefit for the hearing-impaired. And the University has established a spin-off company, VAST Audio Pty Ltd, to commercialise our efforts," says Jin.

Jin's innovation has won him a place at Fresh Innovators-a national initiative to bring the work of 16 early-career inventers to public attention. After training in Sydney, the Innovators are talking to the media, schools and business about their ideas. One of the 16 will win a study tour to the UK courtesy of the British Council Australia.

Sensory deprivation reduces new cell size in the olfactory system

Wed, 06 Apr 2005 23:45:00 PST

( from http://www.rxpgnews.com ) New Haven, Conn.--Sensory deprivation causes changes in new cell size and excitability in the olfactory system, which governs the ability to smell, according to a study in Neuron by a Yale School of Medicine researcher.

"This gives new insight into how stem cells in the olfactory system may be used to restore function in a brain that has been compromised by degenerative disease or trauma," said Gordon Shepherd, M.D., co-author of the paper and professor of neuroscience at Yale.

Shepherd, on sabbatical with Pierre-Marie Lledo of the Pasteur Institute, investigated how the olfactory system responds to changes brought about by injury or different levels of activity. They closed one nostril in mice, a common sensory deprivation procedure, and then observed how the olfactory system adjusted to the change in sensory input.

The olfactory system is one of the most plastic regions of the brain, with nerve cells that are continually replenished by stem cells. Stem cells in the nose replenish the sensory cells, which send the odor messages to the olfactory bulb. "There also are stem cells deep in the brain that replenish the interneurons, which carry out much of the processing of the odor messages that takes place in the olfactory bulb," Shepherd said.

When deprived of sensory input, there was a reduction in the size of the new interneurons, but this was compensated by an increase in their excitability. Shepherd and colleague Michele Migliore, visiting scientist from Palermo, Sicily, carried out simulations which showed how these two changes balance each other. "This preserves the function of the interneurons in being able to process input if it were to be restored," Shepherd said.

In another recent study, Shepherd and Migliore extended their model to show how processing takes place within the olfactory networks. The new data on plasticity will be incorporated into the new model.

Stem Cells to Help Hearing Impaired

Tue, 29 Mar 2005 15:29:00 PST

( from http://www.rxpgnews.com ) Researchers at Indiana University School of Medicine are several steps closer to the day when a profoundly deaf patient's own bone marrow cells could be used to let him or her hear the world.

The IU group, led by Eri Hashino, Ph.D., was able to transform, in the laboratory, stem cells taken from adult bone marrow into cells with many of the characteristics of sensory nerve cells -- neurons -- found in the ear. The results suggest that these adult stem cells could be used to treat deaf patients in the future, said Dr. Hashino, an associate professor and Ruth C. Holton Scholar in the Department of Otolaryngology -- Head and Neck Surgery.

The cells used in the research are called marrow stromal cells -- a type of stem cell from which fat, bone and cartilage normally develop.

"We were interested in marrow stromal cells because of their potential for use in autologous cell-based therapy," said Dr. Hashino, referring to cell transplantation in which a patient's own cells are used in treatment. The cells can be collected easily and kept alive in the laboratory until needed, she said.

Other researchers had previously shown that the marrow stromal cells could be induced to transform into neuronal cells, but it wasn't clear whether, or how, the cells could be further transformed into useful specialized neurons.

In a two-step process, Dr. Hashino and her colleagues first cultivated mouse marrow stromal cells with chemicals known to encourage stems cells to change into primitive neurons. The bone marrow cells took the shape and other characteristics of neurons. Next, they exposed the cells to two molecules that are secreted from nearby tissues of the ear during embryonic development. The two molecules -- known as Sonic hedgehog and retinoic acid -- together caused the marrow stromal cells to further develop into cells with many of the characteristics of auditory neurons, such as the presence of specific genes and proteins.

Dr. Hashino said she and her colleagues are beginning new experiments to test the feasibility of marrow stromal cell transplantation to stimulate the growth of the nerve cells that are often missing from the inner ears of patients with profound hearing loss.

"Sonic hedgehog and retinoic acid are molecules found in embryonic tissues, but not in adult tissues," said Dr. Hashino. "This suggests that treating marrow-derived stem cells with these molecules before transplantation might greatly enhance the possibility that the process would result in development of specific sensory neurons."

Minimally invasive surgery is a safe, effective therapy for geriatric patients

Thu, 30 Dec 2004 17:43:00 PST

( from http://www.rxpgnews.com ) Minimally invasive surgery to alleviate the pain and pressure of sinusitis is a safe, effective therapy for geriatric patients who can't be helped by medication alone, according to new research.

"This tells us that we should not neglect sinus problems in the elderly; that if medicines don't work, we have a surgical technique that is not that invasive and results in good outcomes," says Dr. Stilianos E. Kountakis, otolaryngologist, vice chair of the Medical College of Georgia Department of Otolaryngology Head and Neck Surgery and a principal author on the study published in the December issue of Otolaryngology Head and Neck Surgery. "There is a way to improve symptoms either with medicine or surgery if necessary, and it's worth pursuing because patients feel better overall and have better quality of life."

Dr. Kountakis and collaborators, led by Drs. J. Chris Colclasure and Charles W. Gross at the University of Virginia Health System, looked at 56 patients over age 60 who underwent functional endoscopic sinus surgery, which uses small cameras and monitors to approach sinuses through the nose and minimize trauma.

They found patients continued to report improvement in symptoms over the year following surgery, had few minor complications and no major complications, Dr. Kountakis says. The findings are comparable to studies of younger patient populations.

Sinusitis, which affects some 30 million Americans, is the sixth most common chronic condition of the elderly, says Dr. Kountakis. "As we mature, the sinus lining is not as efficient at transporting secretions so secretions stay behind, sinuses become obstructed more easily and more easily infected."

Despite the high incidence, sinusitis can go untreated in some elderly patients because other conditions take priority and/or create the perception that sinusitis is more difficult to treat in older patients, says Dr. Kountakis, who directs the Georgia Sinus and Allergy Center.

"We thought that maybe the endoscopic sinus surgery wouldn't be as effective because of the decreased efficiency of the sinuses that naturally occurs with age, but that wasn't the case. We thought maybe other medical problems, might make surgery less safe and effective, but that wasn't the case either," he says.

Instead they found 64 percent improvement in symptoms at three months, 73 percent improvement at six months and 75 percent improvement at 12 months, based on patient reports of their symptoms as well as physical exams.

Medical therapy, including inflammation-reducing steroids, mucus thinners and salt-water douches to moisturize and clean the sinuses, is always the first approach to treatment, Dr. Kountakis says. But after about a month, if the condition is no better, a surgical approach through the nose can be used to remove obstructions and/or widen sinus passages. Typically patients will continue to need some type of medicine following surgery to help keep their condition in check.