By CLIFFORD KRAUSS with SANDRA BLAKESLEE VANCOUVER, British Columbia, — Mad cow disease was diagnosed in a cow in Canada today, and United States health authorities immediately placed a ban on imports of beef, cattle and animal feed from Canada. The report shocked ranchers through much of western Canada, where trading in livestock was immediately halted because of plummeting cattle prices. The shock waves spread through the financial markets, where prices in many Canadian and American meat and restaurant companies fell sharply. Canadian authorities stressed that only one cow out of Canada's total cattle population of 3.6 million was found to be sick and there was no immediate evidence that the disease had spread among livestock or humans. Copyright 2003 The New York Times Company

Keyword: Prions
Link ID: 3828 - Posted: 06.24.2010

--- Using a laser range-finder, neurobiologists have scanned real-life scenes to gather millions of distance measurements to surfaces in each scene -- analyzing the mass of data to explain a series of long-known but little-understood quirks in how people judge distances. The measurements reveal, for example, that the tendency of people to estimate the distance of isolated objects as being six to 12 feet away arises because that is the average distance of actual objects and surfaces in the visual scenes people encounter. Thus, said the Duke University Medical Center neurobiologists, the findings support their theory that the visual system has evolved to make the best statistical guess about distances and other features of visual scenes, based on past experience. Copyright © 1992-2003 Bio Online, Inc.

Keyword: Vision
Link ID: 3827 - Posted: 06.24.2010

Symptoms may pose risk to fetus, raise chance of post-partum depression ANN ARBOR, MI – One in five pregnant women may be experiencing symptoms of depression, but few are getting help for it, a new University of Michigan study finds. And those with a history of depression any time before their pregnancy -- about one in every four women -- are about twice as likely as other women to show signs of depression while pregnant, the study results show. The results reveal troubling under-diagnosis and under-treatment of depression in pregnancy. Twenty percent of the women scored high on a standard survey of depression symptoms, but of those, only 13.8 percent were receiving any mental health counseling, drugs or other treatment. Only about 24 percent of those who had had depression in the last six months were receiving treatment during pregnancy.

Keyword: Depression; Hormones & Behavior
Link ID: 3826 - Posted: 06.24.2010

Scientists at The Scripps Research Institute (TSRI) have designed a new way to make vaccines against drugs of abuse that could become a valuable tool for treating addiction by helping the body clear the drug from the bloodstream. The latest vaccine they created using this approach induces the body to clear nicotine. "These new vaccines greatly suppress the reinforcing aspects of the drug," says principal investigator Kim D. Janda, Ph.D. "Blocking it before it gets to the brain--that's the key."

Keyword: Drug Abuse
Link ID: 3825 - Posted: 05.21.2003

Results presented at APA Wilmington, Del/San Francisco –- An analysis of two studies presented today at the 156th annual meeting of the American Psychiatric Association (APA) examined the use of quetiapine fumarate as a monotherapy for acute mania in patients suffering from bipolar disorder. Pooled results from two 12-week clinical trials involving more than 600 patients showed that 48.1% of patients treated with quetiapine fumarate achieved a response [defined as >50% decrease from baseline YMRS (Young Mania Rating Scale) score], compared with 31.3% of those given placebo. The data presented are among the first to evaluate the efficacy, tolerability and safety of quetiapine fumarate as a monotherapy treatment for acute mania associated with bipolar disorder.1 The studies presented are from two of three Phase III trials that supported AstraZeneca's (AZN: NYSE) Supplemental New Drug Application (sNDA) for quetiapine fumarate, in the adjunctive and monotherapy treatment of acute mania associated with bipolar disorder. The sNDA for quetiapine fumarate was submitted to the U.S. Food & Drug Administration in December 2002. Quetiapine fumarate is currently indicated for the treatment of schizophrenia in adults.

Keyword: Schizophrenia; Depression
Link ID: 3824 - Posted: 06.24.2010

Exclusive from New Scientist Print Edition The remarkable visual vocabulary of cuttlefish, which change the colour of their skin in a flash for communication or camouflage, is being catalogued with the help of a mathematical technique borrowed from signal processing. Independent component analysis (ICA) was invented to untangle mixtures of signals. For example, it can pick out individual voices from the babble of a crowd. Now cuttlefish expert Daniel Osorio and his colleagues from the University of Sussex in Britain are hoping it can help them work out which basic elements cuttlefish use to build up their sophisticated patterns. They called in neuroscientist John Anderson, also at Sussex, to help as they photographed a cuttlefish (Sepia officinalis) swimming around in a tank. © Copyright Reed Business Information Ltd.

Keyword: Animal Communication
Link ID: 3823 - Posted: 06.24.2010

By JOHN O'NEIL For smokers trying to quit, a day can feel a lot longer than 24 hours, and a new study shows that in fact a smoker's sense of time is distorted by going without nicotine. The study, published in the journal Psychopharmacology Bulletin, found that smokers allowed access to tobacco and nonsmokers were equally accurate in estimating a 45-second interval, calculating it on average at 52 seconds. But smokers who had not had cigarettes in 24 hours were off by far more, making an average guess of 71 seconds, said the study's lead researcher, Dr. Laura Cousino Klein, an assistant professor of biobehavioral health at Penn State. Copyright 2003 The New York Times Company

Keyword: Drug Abuse
Link ID: 3822 - Posted: 05.20.2003

DALLAS – – Researchers from UT Southwestern Medical Center at Dallas and the Mayo Clinic have discovered a novel genetic mutation that leads to a debilitating muscle condition known as myasthenia. Myasthenia, a severe form of muscle weakness, usually results from an autoimmune attack against the nerve-muscle junction in which the nerve's communication to the muscle is broken down. In a study appearing this week in the online early edition of Proceedings of the National Academy of Sciences, researchers unveil a new cause discovered in a single patient: a genetic mutation leading to a shutdown in muscle responsiveness to the nerve's electrical impulses. "This was a surprise in that it's a totally different mechanism for a well-researched disease," said Dr. Stephen Cannon, chairman of neurology at UT Southwestern, who studied the consequences of the genetic mutation. "Until this study, every single case of myasthenia ever examined had been attributed to a reduction in what's called the safety factor of neurotransmission – or how reliably the nerve talks to the muscle."

Keyword: Movement Disorders; Muscles
Link ID: 3821 - Posted: 06.24.2010

CHICAGO --- Accumulation of neurofibrillary tau tangles not only causes the memory loss that occurs in Alzheimer's disease but also may be responsible for the memory deficits seen in normal aging and in some cases of mild cognitive impairment, a study from Northwestern University and the University of Miami has found. Mild cognitive impairment is isolated memory loss more severe than what is associated with "normal aging," but without the additional cognitive difficulties or disruptions of daily living activities characteristic of Alzheimer's disease. Individuals with mild cognitive impairment have been shown to develop Alzheimer's at a higher rate than those without cognitive impairment, suggesting that mild cognitive impairment may represent an intermediate stage between aging-related memory loss and Alzheimer's disease.

Keyword: Alzheimers
Link ID: 3820 - Posted: 05.20.2003

By Rossella Lorenzi, Discovery News — Baby seals can recognize their mother's voice in the hubbub of large dense breeding colonies as early as two days after birth, according to a study published in the current issue of the journal Animal Behavior. One of the few investigations of voice recognition in mammals, the study focuses on subantarctic fur seals (Arctocephalus tropicalis) living on the remote Amsterdam Island in the Indian Ocean. "By conducting playback experiments with both natural and synthetic signals, I identified the acoustic parameters effectively used in these recognition processes. I also studied the ontogeny of mother's voice in pup: we demonstrated that pups need to be 2 to 5 days old to be able to recognize their mother's voice," lead author Isabelle Charrier, from University of Alberta, told Discovery News. Copyright © 2003 Discovery Communications Inc.

Keyword: Development of the Brain; Hearing
Link ID: 3819 - Posted: 06.24.2010

Anti-anti-smoking study provokes furore among researchers. HELEN PEARSON Public-health experts are up in arms over a controversial new study claiming that passive smoking may not be a killer. The 39-year analysis, involving some 118,000 subjects, finds that smokers' spouses were no more likely than those in smoke-free households to die from lung cancer and heart disease1. It is co-authored by James Enstrom of the University of California, Los Angeles, and Geoffrey Kabat of the State University of New York, Stony Brook. Based on the findings, Enstrom questions whether banning smoking in public spaces really saves lives. "I feel that the question about whether it protects people from dying is overblown," he says. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Drug Abuse
Link ID: 3818 - Posted: 06.24.2010

3-dimensional pictures of ALS mutant proteins support two major theories about how the disease is caused A new study reveals for the first time how gene mutations lead to the inherited form of amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease. The study suggests that the two most prominent theories of how familial ALS (FALS) and other related diseases develop are both right in part. "No one has ever demonstrated at the molecular level how ALS mutations might lead to disease," says study author John Hart, Ph.D., director of the University of Texas Health Science Center X-ray Crystallographic Core Laboratory in San Antonio. "Using a technique commonly used in structural biology, we could see the intimate details of how toxic familial ALS proteins interact. And we found out that the proteins are interacting in a way they shouldn't be." The study was funded by the National Institute of Neurological Disorders and Stroke and appears in the June 2003 issue of Nature Structural Biology. ALS is a progressive, fatal neurological disease that usually strikes in mid-life. It causes muscle weakness, leads to paralysis, and usually ends in death within 2 to 5 years of diagnosis. Affecting as many as 20,000 Americans, ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 3817 - Posted: 05.19.2003

Was Orton right? Washington, DC – Using functional magnetic resonance imaging (fMRI) to study brain activity in children, researchers today confirmed part of an eighty-year-old theory on the neurobiological basis of reading disability, and shed new light on brain regions that change as children become accomplished readers. Their findings were reported in the May 18 online publication of the journal Nature Neuroscience. In 1925 Dr. Samuel Orton, a clinician and prominent dyslexia researcher, hypothesized that normally developing readers suppress the visual images reported by the right hemisphere of the brain because these images could potentially interfere with input from the left. Advanced technology allowed researchers at Georgetown University Medical Center to discover that children do in fact "turn off" the right side of the visual parts of the brain as they become accomplished readers. This confirms an aspect of Orton's theory--born out of observations of individuals with reading disability--is correct. For the first time, they also were able to demonstrate that different phonological skills relate to activity in different parts of the brain when children read. Phonological skills allow readers to sound out words by correctly associating sounds with written symbols. They are critical for children learning to read and are often found to be impaired in children with developmental dyslexia.

Keyword: Dyslexia
Link ID: 3816 - Posted: 06.24.2010

Overextended polyglutamine in huntingtin protein has eclectic effects on the cell By Ricki Lewis In the late 1800s, Long Island physician George Huntington lent his name to this disorder, which is characterized by uncontrollable, dancelike movements and personality changes.6 After a long illness, individuals with HD die from complications such as choking or infection. The genetic marker discovered in 1983 had the uninspiring name G8 and the gene discovered 10 years later had the equally ineloquent IT15, for "interesting transcript 15." HD was one of the first expanded triplet repeat disorders identified, caused by extra glutamines at huntingtin's amino end. Normal huntingtin has 34 glutamine repeats and is likely antiapoptotic. Mutant proteins with more than 40 repeats cause HD. Wild-type huntingtin is cleaved and stays in the cytoplasm. Elongated, it invades the nucleus, where its effects are dual. "Mutant huntingtin enters the nucleus through pores, losing its antiapoptotic function and generating toxic products. So HD is both a gain of function through the generation of polyglutamine fragments, and a loss of antiapoptotic function," explains Michael Hayden, a professor of medical genetics at the University of British Columbia. Abnormally extended huntingtin may disable transcription factors as well as clog proteasomes. "It is becoming increasingly challenging to make sense of it all, to see all the effects of polyglutamine and to identify those important to the disease mechanism, as opposed to the so-called epiphenomena that just happen," says Kenneth Fischbeck, director of the neurogenetics division at the National Institute of Neurological Disorders and Stroke. HD may reflect an unfortunate pairing: polyglutamine is more likely to aggregate than other amino acids, and neurons are more likely to feel the effects than other cells.7,8 "Neurons appear to be exquisitely sensitive to expanded stretches of polyglutamines. This may be because they no longer divide, they have different sets of proteins expressed, and as they age, their ability to deal with cellular insults decreases," explains Larry Marsh, professor of developmental and cell biology at the University of California, Irvine.4 Adds co-author and colleague Joan Steffan, associate professor of psychiatry and human behavior, "Neurons have a different set of transcription factors expressed than other cells, and these transcription factors are more sensitive to interference by polyglutamine-containing proteins." ©2003, The Scientist Inc.

Keyword: Huntingtons
Link ID: 3815 - Posted: 06.24.2010

When Tessa found out she was pregnant after fertility treatment, she felt a mix of delight and doubt. .... Estimates suggest that 5% of the population may have a different father to the one they think they are related to, says Professor John Burn, of the Institute of Human Genetics in Newcastle. He runs one of the UK's few paternity testing services, which carries out about 300 DNA tests a year - a third of results surprise those involved. But men should be cautious about trying to prove their suspicions, he says, for the truth is often unkind.

Keyword: Sexual Behavior
Link ID: 3814 - Posted: 05.19.2003

A friendly approach works best when a male hyena wants a mate - while bullying or aggressive courting gets him nowhere, researchers have found. The study, of hyenas in the Serengeti, Tanzania, turns on its head the assumption that socially dominant males would have more reproductive success. It also shows that females have clear tactics to keep over-enthusiastic suitors at bay. The researchers used genetic testing to establish which pups had been sired by which males within groups of hyenas. They found that males which had attempted to use harassment or "monopolisation" to mate with females rarely ended up fathering offspring. Males that took their time to "befriend" females had far more success. Friendly tactics included grooming, greeting and making "amicable" gestures. (C) BBC

Keyword: Sexual Behavior
Link ID: 3813 - Posted: 05.19.2003

Chronic wasting disease, a cousin of mad cow disease, is spreading among wild deer in parts of the U.S. Left unchecked, the fatal sickness could threaten North American deer populations--and maybe livestock and humans By Philip Yam A place called the eradication zone, lying about 40 miles west of Madison, Wis., covers some 411 square miles. There thousands of white-tailed deer live--or rather, used to live. Last year the Wisconsin Department of Natural Resources instituted special hunting periods to try to wipe out upward of 18,000 deer. During the fall, dead deer were taken to registration areas, where state employees in protective suits and gloves dragged carcasses from pickup trucks and lifted them onto plastic-covered picnic tables. With hacksaws, they severed the heads, double-bagged them and sent them for testing; the bodies themselves were incinerated. © 1996-2003 Scientific American, Inc.

Keyword: Prions
Link ID: 3812 - Posted: 06.24.2010

Although thought of as a psychological problem, the eating disorder anorexia nervosa often runs in families, suggesting that it has a genetic component. Now researchers have found two genes that help determine the risk of acquiring the disease. The results suggest that variations in genes involved in mood and appetite can put women at risk for anorexia. People with anorexia, usually women, have a distorted body image, starve themselves, and tend to be perfectionists. Studies over the last decade have suggested that genes play a role. The risk of becoming anorexic is about half a percent in the general population, but in 2000, researchers found that the risk jumped 11-fold in people with anorexic family members. Family dynamics don't appear to explain the link: Psychiatrist Walter Kaye at the University of Pittsburgh and colleagues found a variation of a region on chromosome 1 that was common in people with the disease. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Anorexia & Bulimia
Link ID: 3811 - Posted: 06.24.2010

Work published in Journal of Medical Genetics indicates break may lead to an understanding of an important piece of the puzzle Researchers at the University of Alberta have discovered a genetic flaw in a family suffering with schizophrenia that may help to explain an important biochemical process implicated in the onset of the disease. Studying a British mother and daughter, the researchers discovered that both were found to have a "break" in a large gene on human chromosome 14, due to a rearranged chromosome. The broken gene is a member of a family of similar genes affecting brain development and function. The genes in this group are involved in behaviour, memory and regulating day/night cycles.

Keyword: Genes & Behavior; Schizophrenia
Link ID: 3810 - Posted: 05.19.2003

* Mecamylamine is a drug that blocks the effects of nicotine in the brain. * Mecamylamine is believed to reduce the rewarding effects of cigarette smoking. * A new study has found that mecamylamine also reduces self-reported stimulant and euphoric effects of alcohol in humans, as well as their desire to drink more. Mecamylamine is a central nicotinic receptor antagonist that is believed to reduce the rewarding effects of cigarette smoking. Scientists have suspected for some time that common mechanisms may be involved in both nicotine and alcohol reward. Furthermore, prior research has suggested that mecamylamine blocks the reinforcing effects of alcohol in animals. A new study, published in the May issue of Alcoholism: Clinical & Experimental Research , has found that mecamylamine reduces the self-reported stimulant and euphoric effects of alcohol in humans, and also decreases their desire to drink more. "Of all the drugs that act in the brain to produce their rewarding effects," said Harriet de Wit, associate professor in the department of psychiatry at the University of Chicago and corresponding author for the study, "alcohol has some of the most complex and varied effects on neurotransmitter receptor systems. One of the receptor systems where alcohol may act is the nicotinic acetylcholine (NACh) receptor system, the same system where nicotine acts. By acting at these NACh receptors, alcohol also increases the activity of another neurotransmitter system, the dopamine system, which is where most drugs are thought to produce their rewarding effects. We hypothesized that mecamylamine would block the effects of alcohol on the NACh receptors which would, in turn, reduce the activity of the dopamine system, resulting in a dampening of the rewarding effects of the alcohol."

Keyword: Drug Abuse
Link ID: 3809 - Posted: 05.19.2003