CHAPEL HILL -- Last March, a multi-center national study made headlines by concluding that taking a combination of the hormones estrogen and progestin did not improve the quality of life for women who are free of menopause-related symptoms but did expose them to a slightly higher risk of heart attacks, strokes and breast cancer. For that reason, many medical scientists began recommending against the combined therapy in the absence of such symptoms, saying the risks of estrogen plus progestin outweighed the benefits. The latest findings from Women's Health Initiative studies provide new evidence that the combined hormone therapy significantly boosts the risks of dementia and strokes in postmenopausal women while not improving what scientists call "global cognitive function" -- how the brain works.

Keyword: Hormones & Behavior; Alzheimers
Link ID: 3848 - Posted: 05.28.2003

With an estimated 44 million adults affected, chances are that you know someone with a mental disorder. Many scientists believe that a variety of these brain ailments arise from complicated interactions between multiple genes and the environment. Now new technologies, including a tool known as a microarray that allows researchers to evaluate thousands of genes in a single experiment, are helping push the field forward. In examples of recent work, microarray studies provided insights into how sets of genes link to depression and schizophrenia. Altogether, new findings are helping researchers better understand the underpinnings of mental disease so they can develop improved treatments. Harrowing feelings of sadness, hopelessness and pessimism have sapped away your friend’s interest to participate in life and kept her under the covers for days. You wonder what put your pal in the glare of depression. Now, new technologies, including a tool known as a microarray, are helping push the field forward. In examples of recent work, microarray studies provided new insights into how sets of genes link to depression and schizophrenia. Copyright © 2003 Society for Neuroscience

Keyword: Genes & Behavior; Schizophrenia
Link ID: 3847 - Posted: 06.24.2010

By BARRON H. LERNER, M.D. What would you do if your baby was born intersex, with sex organs and external genitalia not clearly male or female? How would you choose whether to bring up your child as a boy or a girl and decide whether doctors should perform corrective genital surgery? A series of new studies and a book, "Intersex and Identity" (Rutgers University Press, 2003), seek to provide the answers to these questions. Yet despite this research, the ultimate choices may have less to do with a child's medical condition than with the hospital selected for childbirth. If this sounds like an anomaly in an era of evidence-based medicine, you are right. It was only a dozen years ago that decisions about intersex children, who make up roughly 1 in 2,500 births, were made independently by physicians. So when infants were born with congenital adrenal hyperplasia, in which the female sex organs do not respond to hormones in utero, doctors shortened the enlarged clitorises and created vaginas. Surgeons converted boys born with extremely small penises, a condition known as micropenis, into girls, building clitorises and vaginas. Copyright 2003 The New York Times Company |

Keyword: Sexual Behavior
Link ID: 3846 - Posted: 05.28.2003

Jane Elliott BBC News Online health staff When Nadien Lucas went to bed she could hear the sound of cars and a horse in the field behind her house. But just hours later there was a deafening silence. For two years she lived in a world without sound, until doctors fitted her with a cochlear implant and finally restored her hearing. She had suffered from a viral infection and lost the hearing in one ear, but doctors reassured her that she would be able to hear with her remaining ear, which had also been affected. But then overnight this last contact with the hearing world was shattered. When she woke up she could not hear the toilet flushing or the tap water running. (C)BBC

Keyword: Hearing
Link ID: 3845 - Posted: 05.26.2003

Alzheimer's affects four million people worldwide Scientists have taken a step towards finding out why memory deteriorates with age. Researchers in the United States have found that memory loss may be linked to so-called brain tangles. These occur when twisted fragments of proteins within nerve cells clog up the cells. Large numbers of these tangles are already known to cause Alzheimer's disease. This latest research, by Dr Angela Guillozet and colleagues at Northwestern University, indicates that these tangles also occur in people who do not have Alzheimer's. They examined the brains of eight dead people. Three had suffered from mild cognitive impairment - a more severe form of memory loss than that associated with ageing but less severe than Alzheimer's. The remaining five had healthy brains. The researchers found tangles in all of the brains. However, the number of tangles was higher in those with mild cognitive impairment. (C) BBC

Keyword: Alzheimers; Learning & Memory
Link ID: 3844 - Posted: 05.26.2003

New research by psychologist Dr Stephen Joseph at the University of Warwick reveals that women who experience traumatic childbirth can develop symptoms of post-traumatic stress disorder (PTSD), a serious condition of anxiety usually associated with events like wars and assaults. Although health workers and psychologists are increasingly aware of postnatal depression, post-traumatic stress disorder goes widely unrecognised. Some PTSD symptoms are very similar to those experienced by those with postnatal depression, so health professionals sometimes misdiagnose the condition. However, the conditions are distinct and women with PTSD often go undetected by health workers as this is not a condition that is routinely screened for. Posttraumatic stress can develop after exposure to a frightening event or ordeal in which physical harm occurred or was threatened. Studies suggest between 2 - 5% of women might develop PTSD following difficult and traumatic childbirth, and a much larger number are likely to suffer from some of the symptoms of PTSD, such as intrusive thoughts about what happened and nightmares, even if they don't develop the full syndrome.

Keyword: Stress
Link ID: 3843 - Posted: 05.26.2003

Genetics professor's amusing look into the science of maleness Carl T. Hall, Chronicle Science Writer HOUGHTON MIFFLIN; 222 PAGES; $25 In "Y: The Descent of Men," Steve Jones, professor of genetics at University College in London and author of the much-admired "Darwin's Ghost" and "The Language of Genes," gives us one of the more arresting openers of this spring's crop of nonfiction. "Ejaculate," he suggests, "if you are so minded and equipped, into a glass of chilled Perrier. There you will see a formless object, but look hard enough -- or at least so eighteenth-century biologists believed -- and a baby appears: the male gift to the female, whose only job is to incubate the child produced with so much labor by her mate. So central seemed a husband's role that his wife was a mere seedbed, a step below him in society, in the household, and, most of all, in herself." ©2003 San Francisco Chronicle

Keyword: Sexual Behavior
Link ID: 3842 - Posted: 06.24.2010

By MATT RIDLEY VANCOUVER, British Columbia — Alarming as it was to learn last week that mad cow disease had appeared in North America, the news could have been far worse. Thanks to advances in bioscience and technology, we can now stop an epidemic like mad cow disease, and its human offshoot, Creutzfeldt-Jakob disease, in its tracks. Little is known so far about the particular case discovered last week in western Canada. The black Angus cow was 6 to 8 years old, officials said, and had lived on six ranches and had had five or more calves. Nine herds have been quarantined so far. In Britain, the mad cow epidemic that began in the late 1980's infected nearly 200,000 cattle before it was halted, and more than 120 people died through infected meat. The episode shattered the British public's confidence in government reassurances about food safety, and contributed heavily to British and European refusal to accept official assurances about the safety of genetically modified crops. The environmental movement managed to make much of this distrust, using it to promote fears of interfering with nature, whether through technology or industrial agriculture. Copyright 2003 The New York Times Company

Keyword: Prions
Link ID: 3841 - Posted: 06.24.2010

It’s estimated that at least 4.5 million U.S. adolescents are cigarette smokers. Each day, nearly 4,800 teens smoke their first cigarette, and nearly 2,000 of them will become regular smokers. That’s almost two million annually. “Of all the people alive in this world today, we expect half a billion will be killed by cigarette smoking—two-thirds in poor countries,” Greg Connolly director of the Tobacco Control Program at the Massachusetts Department of Public Health, told PBS’s NOVA. “And of those two-thirds, half are children under the age of 18.” Now some teenagers are smoking cigarettes they perceive to be safer than conventional ones—additive-free cigarettes, and hand-rolled unfiltered cigarettes from India called bidis. Bidis, which are wrapped in tendu leaves, are especially appealing to teens because they are cheaper than regular cigarettes, and come in flavors like strawberry, chocolate, and black licorice. © ScienCentral, 2000-2003.

Keyword: Drug Abuse
Link ID: 3840 - Posted: 06.24.2010

Maybe you really are what you eat. This would solve the long-time mystery of why so many of Guam's Chamorro people – up to a third per village -- suffered a devastating neurological disease. A new study suggests that they gorged on flying fox bats that in turn had feasted on neurotoxin-laden cycad seeds. "Through the consumption of cycad-fed flying foxes, the Chamorro people may have unwittingly ingested large quantities of cycad neurotoxins," say Clark Monson of the University of Hawaii, Honolulu, Sandra Banack of California State University, Fullerton, and Paul Cox of the National Tropical Botanical Garden in Kalaheo, Hawaii, in the June issue of Conservation Biology. Guam's indigenous Chamorro people historically had a high incidence of a neurological disease with similarities to Lou Gehrig's, Parkinson's and Alzheimer's diseases. Called ALS-PDC (amyotrophic lateral sclerosis-Parkinsonian dementia complex), the disease's symptoms range from muscle weakness and paralysis to dementia. The rate of ALS-PDC has been as much as 100 times higher in Guam's Chamorro people than in the continental U.S.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 3839 - Posted: 06.24.2010

Brain changes that occur with cocaine use and the tendency toward relapse may be reduced by a behavioral treatment using extinction training--a form of conditioning that removes the reward associated with a learned behavior. NIDA-funded researchers found that extinction training during cocaine withdrawal produces changes in brain receptors for glutamate, a brain chemical found in the nucleus accumbens, the reward center of the brain. A reduction in glutamate input from cortical brain regions by chronic cocaine use is thought to contribute to persistent cravings for the drug. The researchers trained rats to self-administer cocaine by pressing a lever and to associate the availability of cocaine with certain environmental cues (lights and noise). Once the rats had learned to expect cocaine when they pressed the lever, cocaine and the cues were removed so that the rats did not receive the cocaine that they were anticipating. One group of rats received this extinction training during cocaine withdrawal while another group did not receive the training. After extinction training was over, the researchers exposed the rats to the cocaine-associated cues and administered cocaine to induce relapse.

Keyword: Drug Abuse
Link ID: 3838 - Posted: 05.24.2003

When it comes to tolerating spicy foods, not all mouths are created equal. Findings published today in the journal Science help explain why that is the case. Researchers have identified a lipid molecule that plays a critical role in controlling the severity of a burning sensation. Scientists have known for some time that it is a compound known as capsaicin that gives chili peppers their kick. In the mouth, the capsaicin receptor (TRPV1) governs the level of pain that can accompany a spicy meal. Elizabeth D. Prescott and David Julius of the University of California, San Francisco, investigated a specific binding site within TRPV1. They discovered that a lipid molecule known as PIP2 is usually bound to the receptor, but in the presence of capsaicin, it is released, creating a painful sensation. The strength with which PIP2 is bound to TRPV1, the researchers found, thus determines how sensitive the neurons are to the spice. © 1996-2003 Scientific American, Inc.

Keyword: Pain & Touch; Chemical Senses (Smell & Taste)
Link ID: 3837 - Posted: 06.24.2010

Butterfly flight simulator sheds light on epic migration During their winter migration to Mexico, monarch butterflies depend on an internal clock to help them navigate in relation to the sun, scientists have found. By studying monarchs inside a specially designed flight simulator, the researchers have gathered what they believe is the first direct evidence of the essential role of the circadian clock in celestial navigation. The study appears in the journal Science, published by the American Association for the Advancement of Science (AAAS). In the fall, monarch butterflies journey from central and eastern North America to a small region in central Mexico. Only every fourth or fifth generation makes the trip, indicating that the urge to migrate is instinctive, rather than learned.

Keyword: Biological Rhythms; Animal Migration
Link ID: 3836 - Posted: 05.23.2003

St. Louis, — Scientists at Washington University School of Medicine in St. Louis have gained new insights into the causes of human deafness and balance disorders by studying the inner ear of chickens. The research provides new clues as to why birds can replace critical cells in the inner ear and humans cannot. Loss of these so-called sensory hair cells in humans is a leading cause of deafness and impaired balance due to aging, infectious disease and exposure to loud noise. The study will be published in the June 1 issue of the journal Human Molecular Genetics and appears online today. The team measured the activity of more than 1,800 genes in sensory cells from two regions of the chicken inner ear: the cochlea, where sound is converted into nerve impulses, and the utricle, where balance is sensed. The utricle of birds replaces sensory cells regularly, while the cochlea replaces them when they die. The investigators discovered more than 100 significant differences between the two regions.

Keyword: Hearing
Link ID: 3835 - Posted: 06.24.2010

Hints emerge that doomed jab did some good. HELEN PEARSON A controversial vaccine may stall Alzheimer's disease, despite having serious side-effects, new research suggests. The study revives optimism that a tweaked version of the shot could reach the clinic. Early hopes for the vaccine died in January 2002, when a handful of patients in a clinical trial of the treatment developed brain inflammation. The results forced Elan, the Dublin-based company behind the vaccine, to stop the tests. Now a team led by Roger Nitsch of the University of Zurich in Switzerland has released the first data on how patients fared after immunization. Independently of Elan, the researchers monitored 30 patients in the clinical trial after it stopped1. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Alzheimers
Link ID: 3834 - Posted: 06.24.2010

CHAPEL HILL -- Adults with attention-deficit-hyperactivity disorder treated long term with an extended-release mixed-salts amphetamine medication maintained significant symptom improvement with good tolerance, a new study shows. University of North Carolina at Chapel Hill researchers presented the study results - from one of the largest trials ever conducted of adult ADHD - today (May 21) at the American Psychiatric Association annual meeting, the world's largest psychiatric conference. "ADHD is not just a childhood disorder. While hyperactivity may sometimes diminish by adulthood, inattention and impulsivity often remain," said Dr. Richard H. Weisler, adjunct professor of psychiatry at UNC's School of Medicine.

Keyword: ADHD
Link ID: 3833 - Posted: 05.22.2003

An enzyme crucial to formation of Alzheimer’s plaques and tangles may hold promise as a target for future medications, suggest studies in mice and cells. By blocking the enzyme, lithium stems the accumulation of beta amyloid, which forms Alzheimer’s plaques, scientists funded by the National Institutes of Health (NIH) report in the May 22, 2003 Nature. Inhibiting the enzyme, glycogen synthase kinase — 3 alpha (GSK-3 alpha), also blocks formation of neurofibrilary tangles by the tau protein. “Although widely used to treat bipolar disorder, lithium’s propensity to cause side-effects may limit its use in older people, who are more susceptible to Alzheimer’s disease,” cautioned Peter Klein, M.D., University of Pennsylvania School of Medicine, who led the research team, which was funded by the National Institute of Mental Health (NIMH) and the National Institute on Aging (NIA). It will also be important to develop “new agents” that specifically target GSK-3 alpha, he added. To pinpoint the enzyme’s role in the formation of amyloid plaques, the researchers first treated cells expressing the amyloid precursor protein with lithium, which they had earlier shown blocks GSK-3. Therapeutic doses of lithium inhibited the production of beta amyloid. Another GSK-3 inhibitor, structurally unrelated to lithium, also reduced production of beta amyloid, as did blocking expression of the GSK-3 alpha protein. Likewise, raising GSK-3 alpha levels enhanced beta amyloid production. These experiments established that the enzyme is required for maximal amyloid processing.

Keyword: Alzheimers
Link ID: 3832 - Posted: 06.24.2010

COLUMBUS, Ohio -- Musicians who hear the music they are performing while learning a new piece have a better memory for the music later, a new study suggests. But after they learn a song, actually hearing the music as they play does not improve the accuracy of their performance. These results shed new light on how memory works and on theories about how people learn, said Caroline Palmer, co-author of the study and professor of psychology at Ohio State University. Specifically, Palmer said the findings cast doubt on the universality of matching theories – theories that state memory works best when conditions are similar during learning and during recall of the information.

Keyword: Hearing; Learning & Memory
Link ID: 3831 - Posted: 06.24.2010

ST. PAUL, MN - Public education is needed about the symptoms and risks of mini-stroke, also called transient ischemic attack or TIA, according to the first large study on the topic, which is published in the May 13 issue of Neurology, the scientific journal of the American Academy of Neurology. The study found that only 9 percent of people could give the definition of a TIA or identify a symptom of TIA. TIA symptoms are the same as those for a regular stroke, but TIA symptoms resolve themselves within 24 hours. The phone survey of more than 10,000 people found that 3.2 percent had TIA symptoms but never saw a physician about them. Among those with a TIA diagnosis, 16 percent saw the doctor more than a week after the symptoms occurred. “People think that because these symptoms go away quickly, they don’t need to worry about them, but that’s definitely not the case,” said study author and neurologist S. Claiborne Johnston, MD, PhD, of the University of California, San Francisco. “People who’ve had a TIA are at high risk of having a stroke, particularly in the first few days after the TIA, and doctors can help them reduce that risk. ”

Keyword: Stroke
Link ID: 3830 - Posted: 06.24.2010

A whole lot of shaking helps bring your eyes into sharp focus By Eric Haseltine Your brain cells are sometimes like hyperactive children that get bored quickly. For instance, without a constant change of scenery, neurons in your visual system will literally tune out incoming information in search of fresh stimulation. Fix your gaze on the black "eye" in the center of Figure A for 20 seconds, while trying not to blink. After six or seven seconds, the dotted circle will begin to fade in and out of your awareness. Called Troxler fading, for Ignaz Paul Vital Troxler, a Swiss scientist who described the phenomenon in 1804, the effect is believed to be caused by a rapid decrease in the eye's response to images that are stabilized on the retina. Notice that if you scan your eyes back and forth across the black eye, causing slight shifts in the images on your retinas, the dotted circle will not vanish. © Copyright 2003 The Walt Disney Company

Keyword: Vision
Link ID: 3829 - Posted: 06.24.2010