October 3: Viagra may aggravate sleep disorder, Reuters
Anti-impotence drug could worsen breathing problems of apnea patients
NEW YORK - Viagra (sildenafil) taken at bedtime may worsen breathing problems in patients with severe obstructive sleep apnea, results of a study published in the Archives of Internal Medicine suggest.
Obstructive sleep apnea is a common problem that occurs when the soft tissues at the back of the throat collapse and close off the airway during sleep, resulting in brief moments in which breathing stops.
Impotence, also known as erectile dysfunction, is highly prevalent in patients with obstructive sleep apnea, note Dr. Suely Roizenblatt, of Federal University of Sao Paulo, Brazil, and colleagues. However, sildenafil prolongs the action of nitric oxide, which promotes upper airway congestion.
The researchers therefore examined the effects of a single 50-mg dose of sildenafil on the sleep of 14 men (average age, 53.1 years) with severe obstructive sleep apnea.
The subjects were randomly assigned to receive sildenafil or a placebo ("sugar pill") before they participated in an all-night sleep study, which included at least 7 hours of recording time). The subjects switched treatments and process was repeated the next night.
Compared with placebo, sildenafil led to a significantly increased desaturation index, the number of episodes of oxygen reduction per hour of recording time (30.3 events per hour versus 18.5 events per hour). There was also a significant increase in the percentage of total sleep time with an oxygen saturation of less than 90 percent (15.6 percent versus 7.9 percent) and a significant increase in the maximal duration of a desaturation event (72.5 s versus 48.1 seconds).
Sleep structure was also altered by sildenafil use, with in increase in stage 2 non-rapid eye movement sleep compared with placebo and a decrease in deep sleep compared with the start of the study and placebo, Dr. Roizenblatt’s team reports.
Because of the small sample size, the results should not be extrapolated to all obstructive sleep apnea patients. "Nevertheless," they say, "sildenafil should be used with caution for treating erectile dysfunction in individuals with a sleep-related breathing disorder."
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October 3: Many Women Delay Sleep Apnea Treatment, Forbes.com
(HealthDay News) -- Many women with obstructive sleep apnea put off seeking diagnosis and treatment for the ailment, Canadian researchers say.
Early diagnosis and treatment of the condition can ease symptoms and help curb health-care costs, the study concluded.
Obstructive sleep apnea occurs when the tissue in the back of the throat collapses and blocks the airway during sleep. An estimated 15 million to 20 million Americans have been diagnosed with the condition, and millions more remain undiagnosed and untreated.
The most common and effective treatment for obstructive sleep apnea is continuous positive airway pressure (CPAP), which provides a steady stream of pressurized air to patients to keep their airway open while they sleep.
In the study, researchers at the Sleep Disorders Center at St. Boniface General Hospital in Winnipeg, Manitoba, studied 414 women with obstructive sleep apnea.
They found that the women's use of health-care services increased in the two years prior to their diagnosis, but then declined in the two years after diagnosis.
"Our results showed the sleep clinic evaluation (correcting diagnosis and recommending treatment) in patients with obstructive sleep apnea may lead to a significant reduction in physician claims and ambulatory visits," study author Dr. Katsuhisa Banno said in a prepared statement. "Early diagnosis and treatment of OSA may thus contribute to a significant cost savings to health-care systems," she added.
More information
The American Academy of Family Physicians has more about sleep apnea.
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October 3: For Some Who Lost Their Hearing, Implants Help, The New York Times
By JANE E. BRODY
Jenni Ewald and her husband, Russ, both lost their hearing as young children after bouts with meningitis – Jenni when she was 1, Russ more gradually starting at age 3. They met in college, communicating with sign language and lip reading, fell in love, married and had a baby. But neither could hear their baby cry, at least not until Jenni got a cochlear implant at Loyola University Health System in Maywood, Ill.
Russ was so impressed with Jenni’s result that he underwent the same procedure a few months later. Now living in Tempe, Ariz., both Ewalds can hear their two young daughters.
As victims of profound bilateral sensorineural hearing loss – a destruction of the hair cells in the cochlea of the inner ear that transmit sound signals to the auditory nerve – the Ewalds were not candidates for hearing aids, which simply amplify sounds reaching the ear and depend on normally functioning hair cells.
But they benefited from an implant that makes it possible for profoundly deaf people to hear and learn to interpret speech and other sounds. Perhaps as many as one million people in the United States could benefit from a cochlear implant. For children born deaf or who lose their hearing before they are verbal, the implants enable them to learn to talk.
An Intense Controversy
The surgery cannot create normal hearing; people who receive it can hear but might be described as having mild or moderate hearing loss. That fact has rendered cochlear implants the subject of intense controversy. Many in the deaf community say these less-than-perfect devices can turn a healthy deaf person – who learned to communicate using sign language, lip reading or both – into someone with a hearing handicap whose self-image may be undermined.
Still, those arguments have not stopped some 100,000 people worldwide, including about 25,000 in the United States, from undergoing implant surgery. Roughly half of implant recipients are children. Well-known users of cochlear implants include the conservative commentator Rush Limbaugh; Jack Ashley, the well-known member of the British Parliament; and the 1995 Miss America, Heather Whitestone.
Miss Whitestone was nearly deaf for 28 years until she received an implant in her right ear at Johns Hopkins Medical Center in Baltimore in 2002, allowing her to hear the voices of her two young sons. Early this year she lost what little hearing she had in her left ear and, in August, underwent a second implant, also at Johns Hopkins.
But not everyone with profound hearing loss – uncorrectable with traditional hearing aids – is a candidate for a cochlear implant. Ideal candidates include people with severe sensorineural hearing loss in both ears who still have a functioning auditory nerve; those who have lived only a short time with hearing loss; those with good speech and language skills or, in the case of young children, those in a family willing to work hard to acquire speech and language skills through therapy; those medically able to withstand general anesthesia and surgery, and those who want to live in a hearing world and have realistic expectations about what can be achieved with a cochlear implant.
Dr. John P. Leonetti, a neurotologist at Loyola who performed the implant surgery for the Ewalds, said he depends on the evaluation by the audiologist, who tells him who is – and who is not – a good candidate for a cochlear implant. He said the need for cochlear implants is rising rapidly as the population ages and more and more people lose their hearing and cannot be helped by a hearing aid. Currently, Medicare reimburses only a fraction of the cost of the procedure, keeping it out of reach of many people. Insurance rarely covers the price of even one device, about $40,000, which does not include physicians’ fees, hospital charges and the audiologist’s services.
The Device and Procedure
After decades of experimentation, primarily in the United States, Austria and Australia, the first cochlear implant was approved for use in patients by the Food and Drug Administration in December 1984, initially only for adults and now in children as young as a year old. Special approval is sometimes granted for infants as young as 6 months.
Miniaturization of electronics over the years has resulted in a small two-piece device used in cochlear implants. One, consisting of a receiver and stimulator, is implanted under the skin behind the ear. The other is made up of a microphone, a sound processor and a transmitter that is placed externally over the receiver, held in place magnetically. In the case of young children, the sound processor may be worn in a hip pack or harness. No wires connect the two parts, reducing the risk of infection and damage to the device.
To create sound, the microphone picks up and amplifies noises that the sound processor then filters, giving priority to audible speech. The processor sends electrical signals to the transmitter, which in turn sends the processed sound signals to the internal receiver electromagnetically.
The receiver and stimulator convert the signals into electric impulses, which are sent to an array of up to 24 electrodes. They, in turn, send the impulses to the hair cells and into the brain via the auditory nerve. The two dozen electrodes must fill in for the 16,000 hair cells normally used for hearing.
Efforts are under way to improve the technology. Last week, the F.D.A. approved a system with 120 inputs that is said to enhance the ability to hear music and to improve hearing in noisy environments. It is called the Harmony HiResolution Bionic Ear System, developed by Boston Scientific Corporation.
A Two-Stage Installation
A cochlear implant is installed in two stages. The first involves surgically implanting the internal component into the cochlea, which permanently destroys any residual hearing the person may have in that ear. Though some doctors recommend implanting only one ear, bilateral implants typically result in better hearing. The main drawback of a double implant is the cost.
About four to six weeks later, after complete healing of the implant area, the second external part of the device is installed. This is accompanied by a lot of fine tuning to adjust the signals as well as many months and even years of audiological training and, for those who do not already speak intelligibly, speech therapy.
Without intensive therapy and periodic adjustments of the device, obtaining a cochlear implant is all but useless. An unequivocal commitment to a rehabilitation program – which, in the case of young children, necessarily involves a commitment of the parents – is essential to success.
But even with such a commitment, people who have been profoundly deaf for many years may have a harder time learning to interpret speech through cochlear implants because the part of the brain normally used for hearing can, over the years, become diverted to serve other functions.
Children born deaf who receive cochlear implants before age 2 generally do better with spoken language than those who receive implants at a later age, though the window of opportunity for processing auditory signals in the brain does not close until adolescence. The sound transmitted through a cochlear implant has a robotic quality, but over time and with electrode adjustments, the sound of speech more closely resembles the human voice. and the doorbell, chirping of birds, and other noises sound pretty much as they do to people with normal hearing, Dr. Leonetti says.
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October 9: AHA-HBP: Hypertensive Children At Risk for Sleep Apnea, MedPage Today
Crystal Phend, Staff Writer, MedPage Today
Reviewed by Rubeen K. Israni, M.D., Fellow, Renal-Electrolyte and Hypertension Division, University of Pennsylvania School of Medicine
SAN ANTONIO, Oct. 9 -- Children with high blood pressure are more likely to snore and have other sleep-disordered breathing problems than normotensive peers, researchers said here.
Hypertension is known to be a risk factor for obstructive sleep apnea in adults. But a small study reported at the American Heart Association's Council for High Blood Pressure Research conference has linked the relationship to children as well.
Children with enlarged tonsils and hypertension were more than twice as likely to have sleep-disordered breathing than those with adenotonsillar hypertrophy alone (odds ratio 2.16, 95% confidence interval 1.18 to 3.95, P<0.007), found Alisa A. Acosta, M.D., of the University of Texas at Houston, and colleagues.
Nearly 60% of the study participants with both conditions had sleep-disordered breathing compared with the reported prevalence of 40% in kids with adenotonsillar hypertrophy only.
Likewise, hypertension doubled the odds of sleep-disordered breathing in kids with both obesity and hypertension (OR 2.18, 95% CI 1.19 to 4.01, P<0.007 compared with obesity alone). Nearly two-thirds of those with both conditions had sleep-disordered breathing whereas the reported rate in obese children is 46%.
Sleep-disordered breathing occurs in 2% of children overall and is characterized by short periods of complete (apnea) or partial (hypopnea) upper airway obstructions.
It is particularly important in the pediatric population because it can result in it can result in poor growth and pulmonary hypertension, Dr. Acosta said. Other consequences may include daytime sleepiness, limited attention span, poor school performance, and hyperactivity.
The study included 15 boys and five girls ages four years to 18 (mean age 12.6) who all had hypertension and a history of snoring. Seventeen of the participants were overweight. They underwent nocturnal polysomnography to characterize any breathing problems during sleep.
Dr. Acosta said her clinic routinely screens pediatric patients with hypertension for sleep-disordered breathing risk factors. When children have snoring, enlarged tonsils, a body mass index above the 85th percentile, or nocturnal hypertension by ambulatory blood pressure monitoring, they are selected to undergo nocturnal polysomnography.
Of the study participants, 55% had nocturnal hypertension (11) and 85% had adenotonsillar hypertrophy (17). Seventeen had a body mass index above the 95th percentile (85%), and one child was at the 90th percentile for height, weight and gender.
Sleep disordered breathing was found by nocturnal polysomnography in 60% of the participants (12 of 20).
Of these, seven had obstructive sleep apnea defined as more than one episode of apnea per hour. Another four had obstructive hypoventilation, defined as a maximum partial pressure of carbon dioxide in the blood of more than 53 torr during sleep or greater than 50 torr during more than 10% of sleep or both. One patient had mild sleep disordered breathing, defined as 1.5 apneas and hypopneas per hour.
Among the remaining eight patients without sleep disordered breathing, six had a primary snoring disorder and two had normal polysomnography without snoring.
The researchers said that based on their findings, hypertension in children may constitute an additional risk factor for sleep disordered breathing in addition to obesity and enlarged tonsils, which have previously been shown to be risk factors.
However, since the study was limited by the small number of participants, further studies are needed to confirm the relationship between sleep disordered breathing and hypertension, Dr. Acosta and colleagues noted.
Dr. Acosta suggested that lifestyle changes, such as weight loss and a low-salt-diet, may reduce the risk of sleep disordered breathing in children with hypertension.
Primary source: Conference of the Council for High Blood Pressure Research
Source reference:
Acosta AA, et al "Sleep Disordered Breathing in Children with Hypertension" Conference of the Council for High Blood Pressure Research 2006; Abstract 75.
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October 10: Strep Symptoms: When to Use Antibiotics, The New York Times
By JANE E. BRODY
School is in full swing, it’s fall, and strep-throat season is about to begin.
All physicians and most parents by now know the importance of recognizing and adequately treating a throat infection caused by Group A streptococcal bacteria. These organisms, if not stopped in their tracks by appropriate antibiotics, can result in rheumatic fever and permanently damaged heart valves, among other serious complications.
Thanks to penicillin, which readily kills strep bacteria, rheumatic fever has all but disappeared in countries like the United States. Now physicians are worried about overtreatment, the prescription of antibiotics for children whose sore throats are caused not by bacteria but by viruses that do not cause long-term damage and are not susceptible to antimicrobial therapy.
Some children and adults are healthy carriers of strep bacteria; the organisms reside in their throats but do not make them sick. They rarely, if ever, spread the infection to others. But when such carriers develop a sore throat for any reason, a positive test result for strep typically leads to treatment with antibiotics, which is often needless and possibly hazardous.
Complicated Decision
Symptoms of a strep throat and a sore throat caused by a virus can overlap (children may experience stuffy noses, coughs and sneezing with a strep infection as well as with a cold), further complicating a doctor's decision on whether to treat the illness or to let nature take its course. Nationally, 70 percent of children with sore throats who are seen by a physician are treated with antibiotics, though at most 30 percent have strep infections. And as many as half who are treated with antibiotics because a throat culture was positive for strep are healthy carriers and actually have a cold or some other viral infection, says Dr. Edward L. Kaplan, a pediatrician at the University of Minnesota in Minneapolis and an expert on streptococcal illness.
Antibiotic treatment is best reserved for illnesses in which it is likely to be effective. Overuse of antibiotics can give rise to dangerous antibiotic-resistant bacteria. Antibiotics can wipe out friendly bacteria in the gut, and they sometimes cause life-threatening allergic reactions.
Both Dr. Kaplan and Dr. Alan L. Bisno, an internist at the University of Miami School of Medicine and the Veterans Affairs Medical Center in Miami, say there are usually good ways for physicians and parents to distinguish between sore throats caused by a strep infection and those caused by a virus or some other bacterium.
Group A strep causes 15 percent to 30 percent of sore throats in children, Dr. Kaplan and Dr. Bisno reported in the September issue of Mayo Clinic Proceedings. The illness is most common in school-age children as old as 15.
Strep infections are less common in adults, who are also far less likely than children to develop a serious complication like rheumatic fever if a strep infection goes untreated.
Strep bacteria are shed from the nose and throat of infected people and easily spread to others. This is why strep often makes the rounds in classrooms and day care centers. Occasionally, strep infections "ping-pong" among family members, but "there's no strong evidence that the family pet is a source," Dr. Bisno said.
In a small proportion of children, strep infections occur repeatedly over the course of several years. Jennifer L. St. Sauver and colleagues at the Mayo Clinic in Rochester, Minn., analyzed cases of strep throat occurring at least one month apart among children ages 4 to 15 in Rochester between Jan. 1, 1996, and Dec. 31, 1998. They found that 1 percent of the children (2 percent of those from 4 to 6 years old) had repeated episodes.
Dr. Kaplan and Dr. Bisno point out, however, that as thorough as the Rochester study was, in all likelihood the incidence of repeated strep throat infections is lower than what the researchers found. In only about a third of the cases counted as strep were data available that showed the cases met the accepted clinical profile of a strep infection.
Classic Symptoms
Here are the classic symptoms of strep throat:
- Sudden onset of a very sore throat.
- A beefy red throat and tonsils, sometimes with white patches and pus.
- Difficulty swallowing.
- Fever over 101 degrees.
- Tender and often swollen lymph nodes in the neck.
- Headache.
- Shivers and shaking alternating with cold sweats.
- In children, often nausea, vomiting and abdominal pain.
When someone with a painfully sore throat and fever is taken to the doctor, the appropriate exam includes a rapid strep test - a throat swab that checks for the presence of the strep antigen. The test, which can be done in the doctor's office, takes 5 or 10 minutes to process and is 70 to 80 percent accurate. If the test is positive and the patient has at least some of the classic symptoms of strep, a prescription for an antibiotic - usually penicillin or a derivative - is considered an appropriate course of action.
If the rapid test is negative, a throat culture should also be done in which the throat swab is plated on a laboratory dish and incubated for 24 to 48 hours. This test, when the throat swab is properly done, is considered the gold standard for detecting the presence of strep bacteria. A positive result, when combined with symptoms of a strep infection, warrants antibiotic treatment.
Two Options for Treatment
Dr. Bisno explained that the examining physician has two options. The preferred course of treatment, as described in the 2002 practice guidelines of the Infectious Diseases Society of America, is to wait for the results of the throat culture before starting antibiotic therapy. The physician can write a prescription for antibiotics but suggest that it not be filled unless the throat culture is positive.
The second option, considered less than ideal, is to start antibiotic therapy right away and then stop it if the throat culture is negative, which almost always means the throat infection is caused by a virus, Dr. Bisno said. But, he added, this course of action is reasonable if, in spite of a negative result on the rapid test, "the child is really sick" with symptoms that suggest a strep infection.
An advantage of this option is that if the infection is indeed strep, 24 hours on an antibiotic renders the patient noncontagious, allowing a return to school or work after just a day's absence.
With or without treatment, Dr. Bisno said, strep infections are limited, and most people are better within three or four days. Furthermore, he said, it is safe to wait several days - and perhaps as many as nine days - before starting antibiotic therapy without compromising the chances of preventing rheumatic fever.
In addition, the decision to treat or not to treat can be simplified, Dr. Bisno said, if children with sore throats have symptoms of a cold - "no fever, no red throat, a runny nose and a cough." Such children, he said, "shouldn't be tested at all for strep" and should not be given antibiotics.
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October 11: New York subway could be damaging to ears: study, Reuters
NEW YORK (Reuters) - As little as 30 minutes a day exposed to the high decibel levels of New York's subway system could result in hearing loss -- and wearing an iPod can increase the risk, according to a new U.S. study.
Researchers from the Mailman School of Public Health at the city’s Columbia University found that exposure to the noise levels of the New York transit system can exceed recommended guidelines of the World Health Organization and the U.S. Environmental Protection Agency (EPA).
"A big source of urban noise is mass transit ... (but) it's our means of transportation that is so vital to us that we have to accept it as it is," said Robyn Gershon, professor of sociomedical sciences and lead author of the study.
The study, published in the latest edition of the Journal of Urban Health, found the highest decibel level on the platform was 106, and the average level was 94 decibels.
WHO and EPA guidelines say people should not be subjected to levels of 106 decibels for more than 30 seconds to protect their hearing.
Gershon said people who use personal listening devices to block out the noise were at an even greater risk.
"They are making it that loud because they are trying to drown out all the noise around them, which could be 85 or 90 decibels and that is just too loud," said Gershon, calling this the first scientific subway noise assessment in over 30 years.
So how can the four million or so commuters who use the New York subway system lessen the risks to their hearing?
Gershon suggested standing at the front of the station platform rather than the back or middle as the study found the noise levels were lighter at the front.
"But the best way is to use hearing protection and the cheapest way is to use these little ear plugs that you can buy in pharmacy for about $1 or $2," she said.
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October 12: Hang on to your voice as cold season arrives, MyrtleBeachOnline.com
By Joan Leotta
For The Sun News
The air turns chill and everything is great until the first round of autumn colds begins.
The prospect of a few sniffles may not seem daunting. But when those sniffles "go south" and become a sore throat, then the stakes are higher. Discomfort rises, and of course there is the loss of voice.
This last, often the subject of many jokes, is far from funny if it happens to you. Imagine not being able to tell the grocery clerk if you want paper or plastic or not being heard when you call the pharmacy for a refill. Life’s small tasks become large when one no longer has a voice, albeit temporarily.
There are three stages involved with preparing for the fall cold season: prevention; getting through it quickly, suffering some sore throat but avoiding the no-voice stage; and recovering the lost voice as quickly as possible without serious damage.
Cold and sore throat prevention
The keys to keeping infection at bay are to build up the body's natural immune system with a healthy diet with lots of fruits and vegetables, particularly foods high in vitamin C; keep hydrated with water and avoid things such as alcohol, which dehydrates; get plenty of rest; and wash hands frequently.
Dr. Richard C. Osman of Coastal Carolina Otolaryngology Associations in Myrtle Beach seconds the hand-washing advice and adds, "Most sore throats [like colds] are viral. Wash your hands. Avoid close contact with persons who are [already] sick with viral respiratory infections [colds] or sore throats."
Proper cold-weather clothing is important to maintaining body temperature, according to the University of Pittsburgh Voice Care Center Web site. Living in a normally warm area such as Myrtle Beach makes it easy to forget that hats are important to keep around, especially in the fall, when temperatures can get chilly, even for just a day or two.
The Voice Center advises: "Seventy-five percent of body temperature loss occurs through the head, so a warm hat can decrease temperature loss and reduce the amount of energy required to keep you warm. This saved energy can be used to fight infection."
The site also recommends wearing a scarf in winter to keep cold air from irritating the voice box.
Avoiding getting worse
Once that cold turns into a sore throat, don't give up. Take defensive measures when your throat feels scratchy and a coughing chorus begins to accompany the melody line of sneezes. At this stage, lifestyle remedies include eliminating smoking and avoiding alcohol - not only for its dehydrating effects, but also because it can irritate the throat.
Osmon recommends drinking plenty of fluids and gargling salt water or mouthwash every two hours to clean the throat and kill viruses and bacteria.
"If there are nasal symptoms such as congestion or post-nasal drainage a saline nasal spray and nasal decongestants will help," he said.
The University of Pittsburgh Voice Care Center adds that, in addition to drinking lots of water to help the body get rid of infection, one should avoid things that make the body lose water, including the caffeine found in coffee, tea and soft drinks.
In addition, the Web site advises wariness of allergy and cold medications that contain antihistamines, as those often include an ingredient that can dry out the body.
With regard to lozenges, the Pittsburgh site also advises avoiding the use of throat-numbing lozenges (products containing menthol, phenol or benzocaine) for the simple reason that their pain-numbing effect may lead to a false sense of security and further subsequent injury to your voice. To avoid coughing (which can also harm your voice) they advise staying well-hydrated.
If all of this seems a bit over the top for "just a cold" or to protect your voice, consider the words of Catherine Franz, a Fairfax, Va.-based speaker and writer: "Think of your voices as a rare violin. You wouldn't expose that violin to a night in a smoke-filled room, lay cigars or pour alcohol all over it and expect it not to suffer from abuse the next day!"
So despite your precautions, the germs or virus still seem to be winning and your cold descends into hoarseness or laryngitis.
Resting your voice is a first line of defense against permanent damage and a boon to restoring your normal voice.
Healing book
"The Harvard Medical School Guide to Healing Your Sinus" by Dr. Ralph B. Metson (McGraw Hill, paperback, $14.95)
If your problem is colds that develop into one of a variety of types of sinus infections instead of throat infections - or both - take a look at this book at your local library or bookstore.
The common cold is anything but common. This book lists things to do to avoid colds and includes chapters on what symptoms mean you should be asking your physician to look at your sinuses, not simply tell you to take two aspirin for a cold.
"Healing Your Sinuses" is part of a series of health books published under the Harvard Medical school rubric. While they are complete studies of the ailment (in this case sinus), they do not purport to be physician substitutes. Rather, they are intended to be guides for you to use to know when to call a physician, what to ask your physician and details on treatments a physician may recommend but not explain as clearly as one might like (including, in this case, how to flush out the nasal passages).
The book discusses modern medical and herbal/homeopathic treatments giving the reader fodder for long conversations with the physician. It's a good addition to the library of anyone who is a regular sinus sufferer.
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October 13: Nail polish can contain some risks, The Arizona Republic
Conventional nail polishes dispensed at most drugstores and nail salons contain a veritable witch’s brew of chemicals, including toluene. The chemical has been linked to health issues including headaches; eye, ear, nose and throat irritation; nervous system disorder; and damage to the liver and kidneys.
Another common yet toxic ingredient in conventional nail polish is a chemical plasticizer known as dibutyl phthalate (DBP). According to the Environmental Working Group (EWG), a non-profit research and advocacy organization that campaigns to educate consumers about the health risks of cosmetics, studies have linked DBP to underdeveloped genitals and other reproductive system problems in newborn boys.
As such, DBP is banned from cosmetics in the European Union, but the Food and Drug Administration in the United States has taken no such action.
Luckily, safer nail polishes exist and are readily available at natural health and beauty supply stores as well as from some online outlets.
Major nail polish manufacturers are also now getting in on the act. According to the Campaign for Safe Cosmetics, a coalition of organizations confirmed last year that they would begin removing DBP from products.
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October 16: Risk Factors Identified for Complications After Sleep Apnea Surgery, MedPage Today
By Judith Groch, Senior Writer, MedPage Today
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco
SEATTLE, Oct. 16 – Surgery to correct obstructive sleep apnea (uvulopalatopharyngoplasty) is more likely to have complications if the conditions is severe, a concurrent retrolingual procedure is done, BMI is high, or there are medical comorbidities, found a VA study.
After uvulopalatopharyngoplasty, each additional illness besides sleep apnea almost doubled the risk of serious complications, and having a concurrent non-nasal procedure increased the complication risk almost fivefold compared with noncurrent procedures, according to a report in the October issue of the Archives of Otolaryngology – Head and Neck Surgery.
However, because of the low complication rate in this study, it was not possible to determine individual significance of the risks and whether they were independent of one another, said Edward Weaver, M.D., of the University of Washington here and colleagues. The cumulative complication risk of having a current separate retrolingual procedure is also unknown, he added.
Previous multisite studies of patients who had surgery for obstructive sleep apnea have found an overall 1.6% rate of serious complications, including a 0.2% 30-day mortality rate. But previous reports of risk factors for complications have been conflicting, Dr. Weaver’s team said.
The VA study was in two parts. The first included a prospective cohort of 3,130 consecutive patients (97% men, mean age 50) who had uvulopalatopharyngoplasty (including tonsillectomy) from 1991 to 2001. The patients, from the Veterans Affairs National Surgical Quality Improvement Program database, were analyzed to determine the relationship between perioperative complications and either medical comorbidity or having a concurrent procedure.
Demographic and health variables included age, sex, race, smoking status, and year of operation, a potential confounder because of temporal trends associated with practice patterns.
In this part of the study, 51 patients (1.6%) had complications, the researchers reported.
Comorbidities were associated with serious complications (adjusted risk ratio, 1.96, 95% confidence interval, 1.16-3.18) for each increase in the American Society of Anesthesiologists (ASA) class.
Concurrent nonnasal procedures also increased the complication risk compared with non-concurrent procedures (adjusted risk ratio, 4.94, CI, 2.34-10.4). Nonnasal procedures included various retrolingual surgeries.
Sixteen specific serious complications were identified in the database. These included 30-day mortality; respiratory events (reintubation, pneumonia, prolonged ventilation emergent tracheotomy, or pulmonary edema); cardiovascular events (cardiac arrest, myocardial infarction, cerebrovascular accident, or pulmonary embolism). Other complications included serious hemorrhage, coma, wound infection, deep venous thrombosis, renal failure, and systemic sepsis.
In the large cohort group, most patients had few major comorbid conditions: 79% had none, 14% had one, 6% had two, and 1% had more than two major conditions. About half of the patients had at least one concurrent upper airway procedure, most commonly a nasal procedure.
In the second part of the study, data on BMI, apnea-hypopnea index (disease severity), and oxygen saturation were collected from a nested case-control subset study of 43 of 51 veterans from the original cohort with complications and 212 matched controls.
In this subgroup, the apnea-hypopnea index, body mass index, and medical comorbidity were each associated with serious complications after adjustment for confounding variables.
However, this study had insufficient power to determine whether these risk factors were independent of one another, the researchers said. The same held true for the lowest oxygen saturation, which was not associated with serious complications, Even so, the authors said, the sample size was inadequate to rule out a small effect.
Having another retrolingual procedure at the same time was also independently associated with a serious complication after adjustment for confounders, but the cumulative risk of separate retrolingual procedures is unknown, the investigators wrote.
The study’s limitations included the lack of data on sleep apnea severity and obesity in the prospective database, whereas the case-control analysis depended on the accuracy of recording sleep study results, medical comorbidity, and BMI in the medical records.
Perioperative management may also play a role in the likelihood that serious complications will develop, the investigators noted.
Despite the large sample size, the rare number of serious post- surgery complications may "render this study inadequately powered to isolate the independent significance of various risk factors," Dr. Weaver said.
Finally, he said, because the data came exclusively from veterans, the findings may not be generalizable to all adult patients, because, for example, on average veterans are sicker. On the other hand, he said, the large cohort size, broad geographic distribution, inclusion of various sleep apnea procedures, and variety of surgeons adds to the generalizability of this study.
Primary source: Archives of Otolaryngology – Head & Neck Surgery
Source reference:
Kezirian, EJ, et al "Risk Factors for Serious Complication After Uvulopalatopharyngoplasty" Arch Otolaryngol Head Neck Surg 2006; 132:1091-1098.
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October 17: Obesity Boosts Complications From Sleep Apnea Surgery, HealthDay News
Sometimes sleep apnea is so severe that patients opt for surgery to correct the condition, which can trigger frequent nighttime awakenings.
Now, a new study shows that complications from these surgeries are more likely in the very overweight, those with more severe sleep apnea, and those who have other medical problems.
People with sleep apnea repeatedly stop breathing during the night due to upper airway obstruction. Sleep apnea is associated with an increased risk of cardiovascular disease and poor quality of life.
The most common kind of operation to correct sleep apnea is uvulopalatopharyngoplasty (UPPP), in which surgeons remove the uvula and other soft tissues at the back of the throat in order to clear the airway. About 1.6 percent of patients suffer serious complications, including 0.2 percent who die within 30 days after surgery.
This study, by a team at the University of California, San Francisco, looked at 3,130 patients (97 percent men, average age 50) who underwent UPPP between 1991 and 2001 at U.S. Veterans Affairs medical centers.
Serious complications following surgery were more likely to occur in patients who had more severe sleep apnea, higher body mass index, and those who had additional non-nasal surgeries at the same time and other medical problems. For each additional illness besides sleep apnea that a patient had, the risk for complications almost doubled, the study found.
The findings were published in the October issue of the Archives of Otolaryngology.
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October 19: New Study Provides First Guidelines For Safe Levels Of IPod Music Listening, ScienceDaily
A new analysis of iPods and other portable, digital music players by researchers at the University of Colorado at Boulder and Children’s Hospital in Boston has produced the first-ever detailed guidelines for safe listening levels using earphones.
The study indicates a typical person can safely listen to an iPod for 4.6 hours per day at 70 percent volume using stock earphones, according to Cory Portnuff, a doctoral researcher in CU-Boulder’s speech language and hearing sciences department. Portnuff, who undertook the study with Brian Fligor, director of audiology at Children’s Hospital — the teaching hospital of Harvard Medical School — said the study quantifies both safe and hazardous music listening levels for the typical person.
The researchers found, for example, that listening to music at full volume through an iPod for more than five minutes a day using stock earphones can increase the risk of hearing loss in a typical person. But they also concluded that individuals can safely listen to iPods for 90 minutes a day with the supplied earphones if the volume is at 80 percent of maximum levels without greatly increasing the risk of hearing loss.
"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 findings were presented at a national conference, "NoiseInduced Hearing Loss in Children at Work and Play," held Oct. 18 and Oct. 19 in Covington, Ky.
The researchers found no significant difference in sound levels between five of the most popular genres of popular music they tested, including rock, rhythm and blues, dance, Top 40 and country. Portnuff and Fligor measured specific sound levels from five portable music players, including the Apple iPod, the Apple iPod Nano, the Apple iPod Mini, the Creative Zen Micro and the SanDisk Sansa. The guidelines developed by the researchers apply to all of the music players analyzed in the study, all of which produced similar volumes.
The data was collected at Children’s Hospital in Boston and analyzed at the Hearing Research Laboratory at CUBoulder. The research was funded primarily by the Department of Otolaryngology at Boston’s Children’s Hospital.
Typical individuals can tolerate about two hours a day of a decibel unit known as 91-dBA before risking hearing loss, Portnuff said. The term dBA stands for "A-weighted decibels, a scale that takes into account that the human ear has different sensitivities to different frequency levels," he said.
Loud sounds can stress and potentially damage delicate hair cells in the inner ear that convert mechanical vibrations, or sound, to electrical signals that the brain interprets as sound. "Over time, the hair cells can become permanently damaged and no longer work, producing hearing loss," he said.
But not everyone shares the same risk of hearing loss, Portnuff said. Some people have "tougher ears," allowing them to listen to music relatively safely for longer periods, while those with "tender ears" may suffer ear damage even if they follow the new study recommendations. "There is really no way of knowing which people are more prone to damage from listening to music," he said.
The type of earphones used affect the potential damage to ears, Portnuff said. Socalled "isolator" earphones — which block out background noise — are capable of producing higher soundlevels than earphones with socalled "earbuds." Conversely, "supraaural" earphones that are placed over the ears rather than inside them can be used for longer periods and still be considered safe for typical people, he said.
"No one set of earphones is more dangerous than another," he said. "While isolator style earphones are capable of producing higher levels of sound than earbuds, most people use them at a lower volume than earbuds because they block out background noise. It’s important to monitor the level of volume control settings."
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October 23: FDA rejects Replidyne drug application, The Denver Business Journal
Replidyne Inc. got bad news from the U.S. Food and Drug Administration, which says its new antibiotic isn’t ready to market.
The Louisville company (NASDAQ: RDYN) is working with New Yorkbased Forest Laboratories Inc. (NYSE: FRX) to bring the drug faropenem medoxomil to market.
Replidyne submitted a new drug application for faropenem medoxomil in December for the treatment of sinusitis, pneumonia, bronchitis and skin infections.
The application was filed based on the results of 11 Phase III clinical trials involving more than 5,000 patients.
But the FDA recommended further studies for all four of the proposed indications. The FDA didn’t raise any safety concerns related to the drug.
Replidyne and Forest said they would ask the FDA about what more is needed, including how many more clinical trials they should undertake. The companies said it would be at least two years before the new studies were completed.
Replidyne, which went public in June, has a collaboration and commercialization agreement with Forest. The agreement calls for Replidyne to co-develop and co-market faropenem medoxomil in the United States.
The agreement with Forest calls for Replidyne to receive as much as $250 million in upfront and milestone payments. The company already has received $50 million. Replidyne also is entitled to receive royalties on any future sales of the antibiotic.
Replidyne originally hoped the drug would be on the market in the fall of 2007.
Wall Street reacted to the news by dumping shares of both companies. Replidyne shares lost 45.41 percent of their value to close at $5.59, while shares of Forest were off by 5.69 percent and closed at $48.54.
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October 23: Nasopharyngeal Carcinoma Incidence Higher in Young Blacks Than Whites, Reutes Health
By Will Boggs, MD
NEW YORK OCT 23, 2006 (Reuters Health) — Blacks under 20 years face higher rates of nasopharyngeal carcinoma (NPC) than do whites and even Asians, according to a report in the October Archives of Otolaryngology—Head and Neck Surgery.
"NPC in the U.S. is not a disease affecting only Asians," Luke M. Richey from University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina told Reuters Health. "NPC is a relatively rare neoplasm, and in younger age groups, it occurs in blacks at a rate more than twice that of whites."
Richey and colleagues used data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) tumor registry to investigate incidence and survival rates for cases of NPC in blacks, whites, and Asians younger than 30 years between 1973 and 2002.
Among individuals under age 20 years, NPC incidence rates ranged from 1.61 per million for blacks to 0.95 per million for Asians and 0.61 per million for whites, the authors report.
In the age 20 to 29 group, incidence rates were much higher for Asians (7.18/million) than for blacks (1.87/million) and whites (0.96/million), the results indicate.
Survival rates in younger patients diagnosed with NPC did not differ significantly among blacks, whites, and Asians, the report indicates.
"The higher incidence of NPC in young blacks in the U.S. has multiple causes," Richey said. "Genetic and/or environmental factors lead to cellular or immune alterations, which in the setting of EBV viral infection, give rise to NPC."
"As we accumulate longer followup in national and regional cancer databases, we will be able to further investigate NPC epidemiology and make comparisons between demographic groups," Richey concluded.
SOURCE:
— Arch Otolaryngol Head Neck Surg 2006;132:10351040.
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October 24: Newlyweds say snoring adds stress, United Press International
MINNEAPOLIS, Oct. 24 (UPI) — Sixtyseven percent U.S. newlywed couples have at least one partner who snores, according to a new survey.
Fortythree percent of snorers and 42 percent of the bed partners of snorers said snoring adds stress to their relationship, while 54 percent of the newlyweds with a snoring partner surveyed attribute their sleepless nights to snoring.
In fact, when asked to identify what keeps them up at night, the only thing more likely than snoring to cause sleep loss is stress — 57 percent. However, more lose sleep to snoring more than work and family issues combined, the survey finds.
Snoring not only takes the bliss out of the bedroom — a poor night’s sleep "significantly" affects how 59 percent of the respondents function the next day, according to the survey.
Many newlyweds — 40 percent — consider snoring a fact of life and have not taken any measures to manage the problem; those who try to do something about the problem find nudging, prodding or yelling — 29 percent — are the most common tactics.
Only one in 10 wakes up the snorer, and 7 percent of newlyweds leave their beds and sleep in another room, according to the survey by Impulse Research.
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October 24: Smells like home, The News Journal
By PATRICIA TALORICO
The aroma from a freshly brewed pot of coffee touches a chord deep within Barbara Maletsky that evokes more than just a "mmmm, that smells good" reaction.
The scent always acts as a culinary time machine.
"As soon as I smell coffee, I go back to my Aunt Betty’s house on Thanksgiving Day," Maletsky says. "We’re watching football, we’re satiated and we’re happy. It takes me back to a more simpler time when things were not so complex."
While we may eat with our eyes, we’re actually seduced by a symphony of alluring scents, be it the bouquet of baking bread, the aroma of sizzling bacon or the piney perfume of roasted rosemary chicken.
The way a dish tickles the nose affects us in intimate ways. Wafting aromas can open the door to a warehouse of sentimental memories. Walk through a kitchen, take a deep whiff of freshly baked chocolatechip cookies and suddenly you’re 10 years old again.
The sense of smell is actually much more complex than taste. According to the American Dietetic Association, smell contributes to about 80 percent of a food’s flavor and the rest comes from taste and texture.
After specialized nerves in the nose detect chemical molecules within inhaled air, smell is recognized by an area of the brain known as the limbic system. It’s the same area that also involves emotional behavior and memory. That’s why, researchers believe, when people sniff certain aromas, it often evokes specific memories.
Maletsky, a graduate of the Restaurant School in Philadelphia who now works as a culinary instructor and a private chef, long ago learned that it’s important to entice the brain of someone she is feeding before food ever goes into the mouth.
"If it looks appealing and smells appealing, you’ve already won them. They are already excited about eating," the Bellefonte resident says.
During a recent cooking class at the WilliamsSonoma store in the Shoppes at Brinton Lakes in Glen Mills, Pa., Maletsky cooked an aromatic fruitstuffed pork loin with an apple cider demiglace that made customers salivate.
"It was so fragrant and fallish. It was like we were in a Rockwell painting," she says.
"It was like sensory overload even before they ate it. It was just all the whole anticipation of what was coming."
One of the first things freshman students at the Culinary Institute of America learn is the importance of food aromas.
"For these students, their palate is as much a tool as their knives," says Elana Raider, an associate professor who teaches an Introduction to Gastronomy class at the Hyde Park, N.Y., campus.
As part of her class, Raider shows students how smells are key to flavor by having them do an experiment. She asks them to hold their nose when eating jelly beans. Almost all have trouble identifying flavor.
"All you can taste is a little hint of sweet or sour," Raider says of the basic taste sensations which also include bitter and salty.
"When you unplug your nose, then you get the flavor."
Smells: Love ’em or hate ’em
People have the ability to distinguish between 3,000 and 10,000 different odors, according to the American Academy of Otolaryngology (Head and Neck Surgery).
Women are generally more accurate than men in identifying odors.
"We love – and hate – the smells we do for psychological and evolutionary reasons," says Robert Pierson, chair of the food science and technology department at Delaware Valley College in Doylestown, Pa.
"Things that generally smell good to us – sugary freshbaked cookies or sizzling bacon, for example – are things that we need. We’re genetically built to want to eat sweet and fatty things to build up calories."
Pierson says people are naturally repelled by smells like rotting flesh or garbage because "our bodies know that’s something we should probably steer clear of."
"You can train your body to like things you might first find revolting, though," says Pierson, who previously worked in some of the area’s finest restaurants including The Dilworthtown Inn near West Chester, Pa., and Jake’s Restaurant in Manayunk, Pa.
"No one likes blue cheese the first time they try it. But you can sensitize your palate to like things after a few tastes."
Clemson (S.C.) University’s Department of Food Science and Nutrition is now collecting data on the effects of food aromas on weight loss, genetics and psychology.
Researchers have found that aromas such as chocolate or steak cooking on the grill stimulate the appetite and make people want to eat even if they aren’t hungry. But past studies from the school have found that there are aromas that can suppress the appetite such as fresh green apples, bananas and peppermint.
Smell and taste work together
A sense of smell is most accurate in men and women between the ages of 30 and 60, and then it begins to decline.
Thirty percent of Americans between the ages of 70 and 80 have a problem with their sense of smell, according to the National Institutes of Health. Two out of three people over 80 also will have a problem.
People who lose their sense of smell – through upper respiratory infections, smoking, disease and traumatic head injuries – sometimes believe that food has lost its taste. But it’s usually not the case. The food may have lost its aroma, but the sweet, salty, sour, and bitter tastes will remain.
Just like Aunt Betty, Barbara Maletsky is interested in good aromas.
She says chefs are "forever sniffing and smelling spice jars, fresh herbs, fruits for ripeness, soups for seasoning, the kitchen air to tell if something’s done."
"Smell is, perhaps, the most integral part of our lives as chefs," says Maletsky who hopes she is now helping creating memories for her own family. Recently, she cooked a big Sunday breakfast at her Bellefonte home for her two children, ages 10 and 12, complete with fried ham, eggs, pancakes and, of course, percolating coffee.
"We went out for a walk and then came back home," Maletsky says. "[The house] smelled like a fabulous oldfashioned diner. We just kept walking out and walking back in the house. It just made you happy."
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October 24: Online health searchers don't check sources, The Boston Globe
By Reuters
WASHINGTON -- Only one-fourth of Americans who search the Internet for health advice regularly check the source and date of the information they find to assess its quality, according to a survey released yesterday by the Pew Internet Project.
About 10 million American adults -- or 7 percent of U S Internet users -- searched for information on a health topic or medical problem on a typical day in August, the non profit think tank said. That ranks health searches at about the same level of popularity as paying bills online, reading blogs, or using the Internet to find a phone number or address.
Common health topics searched on the Web include specific diseases or medical treatments, exercise, nutrition, prescription drugs, and alternative medicines, Pew said.
Just 15 percent of those surveyed said they always checked the source and date of the health information online, while another 10 percent said they did so most of the time. Three-quarters of those surveyed said they checked the source and date sometimes, hardly ever, or never, Pew said.
Most Web users look for health information with a general search engine such as Google or Yahoo, the study found.
Several new search engines that focus only on medical topics have become available, including Healthline.com, Medstory.com, Healia.com, Mammahealth.com, and Kosmix.com.
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October 30: Nocturnal Heartburn and Acid Regurgitation in GERD Associated With Supraesophageal Symptoms: Presented at ACG, PeerView Media Bar
By Paula Moyer
LAS VEGAS, NV -- October 30, 2006 -- When patients with gastroesophageal reflux disease (GERD) have nocturnal heartburn and acid regurgitation, they are more likely to have more supraesophageal symptoms throughout the day than do patients with daytime GERD, according to investigators who presented their findings here at the 71st annual meeting of the American College of Gastroenterology (ACS).
"Among patients with nocturnal GERD, 70% reported at least 1 daytime supraesophageal symptom," said primary investigator Ronnie Fass, MD, associate professor of medicine, University of Arizona, and director of GI motility laboratories, Southern Arizona Veterans Affairs Health Care Center, Tucson, Arizona. In contrast, 60% of those with daytime-only GERD reported supraesophageal symptoms.
Examples of supraesophageal symptoms are globus sensation, sinusitis, coughing, sore throat, throat clearing, and night-time snoring, as well as wheezing, choking, noncardiac chest pain, and hoarseness. Knowing the subtype of GERD associated with such symptoms can help physicians take more detailed histories and treat their GERD more effectively, Dr. Fass said in a presentation on October 23rd.
To establish whether such a link existed, Dr. Fass and colleagues conducted an internet-based survey, the GERD Symptom and Medication Questionnaire (GERD-SMQ). Among 18,213 people invited to participate, 2,603 were found to be eligible. Among these, 668 screened positive for GERD, in that they had symptoms within the past 3 months. Within this subset, 303 (45%) met the criteria for nocturnal heartburn and regurgitation.
The investigators also found that patients with nocturnal GERD patients had a higher prevalence of each supraesophageal symptom except for snoring and daytime sinusitis.
The average severity scores among nocturnal GERD cases were greater for all supraesophageal symptoms than those with daytime GERD.
Nocturnal heartburn and regurgitation were linked to more frequent supraesophageal symptoms, regardless of the time of day, Dr. Fass said. "Therefore, supraesophageal symptoms may contribute to the overall burden of disease."
[Presentation title: Patients With Nocturnal Heartburn and Acid Regurgitation Report More Frequent Nighttime and Daytime Atypical GERD Symptoms. Abstract P681]
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October 31: Children: Antibiotics Unhelpful Against Many Ear Infections, The New York Times
By NICHOLAS BAKALAR
Antibiotic treatment for children with ear infections is not helpful in all cases, a new study has found. The report, which appears in the Oct. 21 issue of The Lancet, analyzed data from six studies and included more than 1,600 children from 6 months to 12 years old.
In a few cases, researchers found, antibiotics were useful. Fifty-five percent of untreated children under 2 with infections in both ears still had pain or fever after three to seven days, while only 30 percent of those given antibiotics did. The results for children up to 12 with a fluid discharge from the ear were roughly the same. This suggests that it is advisable to use antibiotics in such cases.
But treating infants who had infection in only one ear was ineffective — 40 percent of untreated children under 2 still had pain after three to seven days, and so did 35 percent of those who received antibiotics. In children older than 2, antibiotics were generally unhelpful. Twenty-six percent of untreated children still had pain or fever after three to seven days, and so did 19 percent of children who received treatment.
The results do not mean that children with ear infections should be left untreated, says Dr. Maroeska M. Rovers, the lead author of the study and an epidemiologist at the University Medical Center in Utrecht, the Netherlands.
"Our study showed that not all children benefit from antibiotics," she said. "But children should be treated with analgesics to control pain and fever. If the symptoms are worsening, or if the analgesics are not helping, parents should call the physician."
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October 31: Tastes Great! Study Shows Brain's Response To Pleasing -- And Changing -- Tastes, Science Daily
We all have tastes we love, and tastes we hate. And yet, our "taste" for certain flavors and foods can change over time, as we get older or we get tired of eating the same old thing.
Now, a new University of Michigan study gives new evidence about what's going on in the brain when we taste something we like, or develop a liking for something we once hated.
And although the study used rats instead of people, it has direct implications for understanding the way we perceive pleasure -- and the reasons why some people develop problems, such as drug abuse, depression or anorexia, that knock their pleasure response off balance.
In a new paper in the November issue of the Journal of Neurophysiology, U-M neuroscientists and psychologists report the findings from direct monitoring of an area of the brain known as the ventral pallidum. Located deep in the brain, it's a kind of traffic center for signals from different areas of the brain that process tastes and pleasurable sensations.
The researchers were able to track the activity of brain cells in that area while the rats received water, salt water and sugar water directly into their mouths. They also recorded how the rats behaved while they tasted those different solutions, including signs that they liked or disliked the tastes. And, they repeated the tests when the rats had been treated with drugs that greatly reduced their bodies' salt levels.
At first, the rats all behaved negatively after tasting a strong salt-water solution, compared to the water or sugar water. Their ventral pallidum brain activity was also much lower in response to the salt water.
But when the researchers put the rats into a salt-deprived state using a combination of diet and hormones that cause the body to get rid of salt, the picture changed. Suddenly, the rats' brain activity rose as high when they received the salt water as it had when they received sugar water. The effect lasted for a while after the rats' bodies returned to normal salt levels, but soon enough it wore off.
"We converted something that wasn't pleasing to something that suddenly became pleasurable, and when we did that the neurons we were studying switched their response," says senior author J. Wayne Aldridge, Ph.D., a research associate professor in the Department of Neurology at the U-M Medical School. "Pleasure has traditionally been one of the hardest problems for neuroscience to measure, but these results shed light on how it is represented in brain activity."
The study was designed so that the signals from the ventral pallidum were only related to the "liking" -- or disliking -- of the taste, and not to a salt-seeking drive or movement. The ventral pallidum is part of the limbic system of the brain, which is involved in motor-muscle control as well as pleasure and reward.
In an accompanying editorial, University of North Carolina researchers Robert Wheeler and Regina Carelli call the study "elegant" and the results a "profound step" toward understanding the nature of pleasure itself, rather than the behaviors and actions triggered by it.
Aldridge collaborated on the study with former U-M Psychology graduate student Amy Tindell, Ph.D., and with Kent Berridge, Ph.D., a professor in the Department of Psychology in the College of Literature, Science, and the Arts.
"This finding reveals a type of brain Morse code for pleasure," says Berridge. "The faster these neurons fire, the more pleasant the taste seems to become. The hardest test for a pleasure code is whether the brain signal can track the change from nasty to nice. The amazing fact is that these neurons pass that test."
Aldridge notes that an analogous effect occurs in everyday human life, when a formerly favorite food becomes less attractive after we have over-indulged in that food.
"Moment by moment, this low-level information processing in the brain helps us react to what we like or don't like," he says. "These neurons respond to a taste as pleasurable, or as not pleasurable."
But research on how these neurons fire to signal pleasure is important for more than just curiosity's sake, he adds. The ventral pallidum is an important brain region for both pleasure and craving. If firing patterns go wrong in ventral pallidum, it could possibly contribute to eating disorders, anorexia and drug addiction.
Eventually, activation in the ventral pallidum in response to pleasurable tastes could also be useful in brain-mapping techniques in humans. All in all, Aldridge says, the new paper is "a really good example of how animal experiments help us understand the human brain. If we can understand how the brain generates normal pleasures, we may have a new focus for effective treatments in people who don't experience normal pleasure."
In addition to Tindell, Berridge and Aldridge, who also holds an adjunct appointment in Psychology, the study's authors include Psychology postdoctoral fellow Susana Pecina and graduate student Kyle Smith. The study was funded by the National Institutes of Health and the National Science Foundation. Reference: J. Neurophysiol, 96: 2399-2409, November 2006; Editorial: J Neurophysiol 96: 2175-2176, November 2006
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