By GINA KOLATA Ask anyone: Americans are getting fatter and fatter. Advertising campaigns say they are. So do federal officials and the scientists they rely on. But Dr. Jeffrey Friedman, an obesity researcher at Rockefeller University, argues that contrary to popular opinion, national data do not show Americans growing uniformly fatter. Instead, he says, the statistics demonstrate clearly that while the very fat are getting fatter, thinner people have remained pretty much the same. Let it be said that Dr. Friedman, a Howard Hughes Medical Institute investigator and the discoverer of the gene for leptin, a hormone released by fat cells, is not fat. He is tall and gangly, with the rumpled look of an academic scientist. As an obesity researcher, he might be expected to endorse the prevailing view that obesity in this country is out of control. But Dr. Friedman said he was outraged by the acceptance of what he sees as a hurtful myth, one that encourages people to believe that if you are fat, it is your fault. Copyright 2004 The New York Times Company

Keyword: Obesity
Link ID: 5609 - Posted: 06.08.2004

By BENEDICT CAREY Moody teenagers who visit therapists for help often wonder how useful all that talk about feelings and emotions really is. Now, many doctors are asking the same thing. Last week, researchers presented findings from a large government-financed study showing that depressed teenagers were much more likely to improve by taking Prozac than by undergoing a standardized form of talk treatment, cognitive behavior therapy. For parents desperately trying to help a depressed teenager, the study may appear to make their choices even more confusing. Already worried by Food and Drug Administration warnings that antidepressants can be dangerous for a small number of children and adolescents, parents now face the news that the best alternative, talk therapy, may be a waste of time. Yet experts say the results of the study are more complicated, and less discouraging, than they might seem at first glance. The study, to be published this year, offers some reassurance that the drugs are probably helping. At the same time, it makes clear that psychotherapy does have a place. Although statistically, therapy alone was no better than a placebo, it did lift depression in 43 percent of the teenagers studied, compared with 35 percent given dummy pills. Almost three-quarters of the adolescents who combined talk and drug treatments improved significantly, and the psychotherapy appeared to reduce the risk of suicide. Copyright 2004 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 5608 - Posted: 06.08.2004

Because we live in a visually complex world, one of the major tasks of vision is to resolve ambiguous information into a stable image of our surroundings. By presenting subjects with differing versions of visually ambiguous images, researchers have identified the factors that are important for perceptual stabilization, a process that allows the visual system to overcome conflicting information and maintain a steady perception of an image. Visual perception is generally accurate and stable. However, when a visual stimulus provides conflicting or insufficient information, perception can be bi-stable or even multi-stable – that is, the way an image is perceived by the viewer can change or switch back and forth over time. By studying the visual system's solution when faced with such ambiguous conditions, Dr. Xiangchuan Chen from the University of Science and Technology of China and Dr. Sheng He from the University of Minnesota sought to tease out clues to the underlying mechanisms of visual perception. Earlier research had shown that perception can be stabilized when the ambiguous visual stimuli were presented intermittently. Memory of the recent perceptual experience had been proposed to explain this stabilization effect. But the nature of this "perceptual memory" has remained unclear.

Keyword: Vision
Link ID: 5607 - Posted: 06.24.2010

A meticulous series of experiments – and the fortuitous use of a vacuum cleaner – lead to breakthrough new insight on the genetic basis of epilepsy. Circadian rhythms -- the normal ups and downs of body rhythms – help organize physiological processes into a 24 hour cycle, affecting everything from body temperature, hormone levels and heart rate, to pain thresholds. Scientists have now discovered that the combined deletion of three circadian genes, encoding the PAR bZip transcription factor protein family, results in accelerated aging and severe epilepsy in mice. Owing to the roughly 95% identity of PAR bZip proteins between mice and humans, it is anticipated that PAR bZip mutations may also underlie some forms of human epilepsy. A copy of this important new study is being released in advance of its June 15th publication date by the journal Genes & Development (http://www.genesdev.org). "The objective of the study was to assign physiological functions to the small family of PAR bZip transcription factors," explains Dr. Ueli Schibler, principal investigator of the study and in whose lab the first PAR bZip transcription factor was found nearly 15 years ago. The PAR bZip transcription factor family is composed of three proteins (DBP, HLF and TEF), all of which display distinct patterns of circadian accumulation: In tissues with high amplitudes of circadian clock gene expression (like the liver), PAR bZip protein levels change up to 50-fold throughout the day. However, in the brain, where clock gene expression varies little, PAR bZip protein levels barely change.

Keyword: Epilepsy; Biological Rhythms
Link ID: 5606 - Posted: 06.24.2010

ST. PAUL, Minn. – Despite limited evidence of effectiveness, many epilepsy and multiple sclerosis patients believe marijuana is an effective treatment and are actively using it, according to two Canadian studies published in the June 8 issue of Neurology, the scientific journal of the American Academy of Neurology. Multiple sclerosis patients in Halifax, Nova Scotia, and epilepsy patients in Edmonton, Alberta, recently participated in a questionnaire and a telephone survey, respectively, regarding patterns, prevalence and perceived effects of marijuana use. Results of these surveys may raise more questions than they answer. In the study of epilepsy patients from the University of Alberta Epilepsy Clinic, 136 subjects responded to the phone survey. Of these, nearly half had used marijuana in their lifetime; one in five had used marijuana in the past year; 20 (15 percent) had used in the past month; 18 (13 percent) used more than 48 days per year; and 11 (8 percent) used more than half the days of the year. Four patients were actually considered marijuana dependent. Odds of frequent marijuana use were eight times greater for patients with frequent seizures and 10 times greater for those who had had epilepsy for at least five years.

Keyword: Drug Abuse; Pain & Touch
Link ID: 5605 - Posted: 06.24.2010

BY TOM SIEGFRIED (KRT) - Some scientists wonder how smart it is to enhance how smart people are. At first glance, it seems like a no-brainer. Smarts are in short supply in the world today, and you'd be tempted to think the more, the better. On the other hand, some ostensibly smart people do some pretty stupid things. Making people smarter might have its dumb side. At the very least, the issue calls for some thoughtful consideration, many neuroscientists and bioethicists believe. Society may soon have to face some tough choices about whether the mental equivalent of Viagra poses more risks than benefits. In the past, the question has been moot, because nobody knew how to enhance mental function, anyway. Even though the "smart pill" industry has become big business, most studies don't show such pills to be very effective. © 2004, The Dallas Morning News.

Keyword: Learning & Memory
Link ID: 5604 - Posted: 06.24.2010

You know the location of your cousin’s house. How to prepare a grilled cheese sandwich. When to wear rain boots. How to calculate a tip for the pizza delivery guy. The list goes on and on. Thanks to memory you can easily navigate life. Many people, however, are not so fortunate. Alzheimer’s disease (AD), for example, which affects some 4 million older Americans, destroys memory and thinking capabilities. Individuals with AD may have trouble recalling addresses, major events, or the name of the president. Making meals and managing finances can become difficult. Over time problems with memory and thinking get even worse. Speech abilities diminish. Dressing and other simple tasks require assistance. For years, the biological basis of memory was unclear, which hindered the search for treatments to improve memory and thinking in those with disorders like AD. Now, a series of recent discoveries have advanced the field. The studies uncover several brain components that appear to play significant roles in memory. What’s more, evidence indicates that methods that target the components can enhance memory. Copyright © 2004 Society for Neuroscience

Keyword: Learning & Memory
Link ID: 5603 - Posted: 06.24.2010

Expressing high levels of a sugar-adding protein known as LARGE in mice that lack the protein can prevent muscular dystrophy in these animals, according to studies by researchers at the University of Iowa Roy J. and Lucille A. Carver College of Medicine. Furthermore, the research suggests that LARGE protein also can restore normal function to a critical muscle protein that is disrupted by glycosylation (sugar-adding) defects in several different human muscular dystrophies. The team's findings, which appear June 6 in an advanced online publication of Nature Medicine and online in the journal Cell on June 3, might lead to new treatments for this particular class of muscular dystrophies and other muscle diseases caused by glycosylation defects. A group of muscular dystrophies, which include Fukuyama Congenital Muscular Dystrophy, Walker-Warburg Syndrome and Muscle-Eye-Brain disease, are caused by mutations in glycosylation enzymes – proteins that add sugars to other proteins. In these diseases, defects in the sugar-adding mechanism disrupt the properties of alpha-dystroglycan, a protein critical for normal muscle function.

Keyword: Muscles; Movement Disorders
Link ID: 5602 - Posted: 06.24.2010

Local snoozing implies that slumber makes for better learning. TANGUY CHOUARD A good night's rest is hard work for parts of your brain, say US neuroscientists. Regions related to learning show increased activity in sleepers who spent their evening mastering a new skill, they say. The discovery shows that sleep is valuable for consolidating new information and is not a simple 'standby' mode. Local brain processing during the night led to new skills being more firmly cemented, the research indicates. Giulio Tononi of the University of Wisconsin-Madison and his colleagues measured electrical brain signals in subjects who learned a simple computer game before going to sleep. The kind of activity that occurs during sleep was increased in a penny-sized region in the brains of slumbering subjects who had learned the game. Just playing the game did not have this effect. The researchers conclude that sleep falls on brain circuits that have been changed, not just used, during the day. (C) Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Sleep; Learning & Memory
Link ID: 5601 - Posted: 06.08.2004

Scientists are working on a new decontamination method to kill the proteins that cause the human form of mad cow disease. They hope their work eradicates even the tiniest potential for patients to contract vCJD from surgical equipment. The technique, a form of electrolysis, has been successfully tested on some forms of protein. Its developers, from Exeter University, hope it will also prove an effective way to kill the superbug MRSA. Lead researcher Dr Claus Jacob told BBC News Online the technique took advantage of the fact that surgical instruments were made of metal, and so could conduct electricity. It works by connecting the instrument to a battery-type device, and feeding through a very low voltage electrical current. This produces a series of chemical reactions on the surface of the instrument, which generate highly reactive oxygen particles that destroy biological matter clinging to the surface of the instrument. In some respects, the technology mimics the way that the body's immune system generates similar oxygen particles to fight off bacterial infection. (C)BBC

Keyword: Prions
Link ID: 5600 - Posted: 06.06.2004

It may sound like a load of quackers but according to new research ducks have regional accents. "Cockney" ducks from London make a rougher sound, not unlike their human counterparts, so their fellow quackers can hear them above the city's hubbub. But their country cousins communicate with a softer, more relaxed sound, the team from Middlesex University found. Ducks, like humans, are influenced by their environment, said Dr Victoria De Rijke, who has been nicknamed Dr Quack. Her research team discovered the difference after recording the quacks of ducks at two separate locations. The birds at Spitalfields City Farm in the heart of the cockney east London, were found to be "much louder and vocally excitable" than the ducks recorded on Trerieve Farm in Downderry, Cornwall, said English language lecturer Dr De Rijke. "The Cornish ducks made longer and more relaxed sounds, much more chilled out. "The cockney (London) quack is like a shout and a laugh, whereas the Cornish ducks sound more like they are giggling," she added. "London ducks have the stress of city life and a lot of noise to compete with, like sirens, horns, planes and trains."

Keyword: Language; Evolution
Link ID: 5599 - Posted: 06.06.2004

By LESLIE BERGER TWO years after a bombshell dropped on hormone replacement therapy, there are signs that the rush away from the drugs is ending. In July 2002, a federal study, part of the Women's Health Initiative, was halted when its data showed the dangers of hormone therapy outweighing its long-term benefits. Sales of the drugs — estrogen and estrogen-progestin — plunged. But new figures show that in recent months the drop appears to be bottoming out. Some doctors report an upswing in demand from menopausal women unable to find other sources of relief. Drugmakers, who have introduced low-dose versions of the products, are making their first new marketing forays. And some prominent doctors are even beginning to argue that women have been needlessly scared away from treatment. Of course, the grand hope of the past is gone: that giving older women a substitute for the estrogen they produced in their youth could stave off heart disease, strokes and dementia. The new approach emphasizes the lowest dose for the shortest time — and only for relief of hot flashes and other menopausal symptoms. Copyright 2004 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 5598 - Posted: 06.24.2010

Loss of cones in the retina may cause some types of colour blindness Scientists have found that some colour blind people are missing as many as one third of the normal number of specialised light-detecting cells. However, apart from colour blindness, the general quality of their sight appears unaffected. The researchers hope their work will enable earlier detection of eyesight disorders. The study, by the University of Rochester, is published in Proceedings of the National Academy of Sciences. The Rochester team used a technique called adaptive optics to study the retina of the eye in much closer detail than has previously been possible. It was originally developed to help astronomers see more clearly through the Earth's atmosphere. Lead researcher Dr Joseph Carroll said: "Not only are we excited to show how this method can reveal us living cells in a way never before possible, but it's revealed a mystery with profound implications. "If a third of the light-receiving cells in your eye are absent and you don't even notice it, it means that when a patient complains to a doctor about waning light sensitivity, then the damage must already be very serious." (C)BBC

Keyword: Vision
Link ID: 5597 - Posted: 06.05.2004

By BARRY MEIER The two drug trials were known within SmithKline Beecham as Study 329 and Study 377. Study 329 suggested that the company's popular drug Paxil might help depressed adolescents. Study 377, completed not long afterward, indicated that Paxil provided no more benefit than a sugar pill in treating depressed young people. But only the favorable study was widely publicized by Paxil's maker. The company chose not to discuss publicly the trial with negative results, and those findings came to light only when an outside researcher on the study team decided to disclose them at a medical conference. "That particular study would have been buried," said that researcher, Dr. Robert Milin of the Royal Ottawa Hospital in Canada. "It would have been buried to the public." Federal regulators in this country are now scrambling to reassess the effectiveness and safety of antidepressants like Paxil, after British regulators touched off a controversy last year by asking drug companies for unpublished data from antidepressant trials. That data suggested that several antidepressants, including Paxil, might give rise to suicidal thoughts in some young users - a potential problem not revealed in any published studies. Copyright 2004 The New York Times Company |

Keyword: Depression; Development of the Brain
Link ID: 5596 - Posted: 06.05.2004

Not all sugars are equal, at least when it comes to weight gain and health Philadelphia, PA -- Researchers at the Monell Chemical Senses Center, the University of California, Davis and other collaborating colleagues report that drinking beverages containing fructose, a naturally-occurring sugar commonly used to sweeten soft drinks and other beverages, induces a pattern of hormonal responses that may favor the development of obesity. It is estimated that consumption of fructose has increased by 20-30% over the past three decades, a rate of increase similar to that of obesity, which has risen dramatically over the same time span. Data from the present study suggest a mechanism by which fructose consumption could be one factor contributing to the increased incidence of obesity. In the study, reported in the June 4 issue of the Journal of Clinical Endocrinology and Metabolism, 12 normal-weight women ate standardized meals on two days. The meals contained the same number of calories and the same distribution of total carbohydrate, fat and protein. On one day the meals included a beverage sweetened with fructose. On the other day, the same beverage was sweetened with an equal amount of glucose, another naturally-occurring sugar that is used by the body for energy.

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 5595 - Posted: 06.05.2004

Dementia in AIDS patients is caused by a large, late invasion of HIV-infected macrophages--large, long-lived cells of the immune system that travel throughout the body and ingest foreign antigens to protect against infection--into the brain, according to researchers at Temple University's Center for Neurovirology and Cancer Biology (http://www.temple.edu/cnvcb/), debunking a longstanding "Trojan Horse" theory that early infection by macrophages remains latent until the latter stages of AIDS. The results of their study, "Macrophage/Microglial Accumulation and Proliferating Cell Nuclear Antigen Expression in the Central Nervous System in Human Immunodeficiency Virus Encephalopathy," was published in the June issue of the American Journal of Pathology [June 2004; Volume 164, Number 6] (http://ajp.amjpathol.org/). The study was funded by the National Institute of Neurodegenerative Disorder and Stroke and the Howard Hughes Medical Institute. "Basically, one of the longstanding models for how HIV causes dementia is the 'Trojan Horse' model," says Jay Rappaport, Ph.D., a professor of biology at the Center, who led the study. "According to this model, early during HIV infection, there may be a few macrophages that are infected and get into the brain and establish an infection in the resident microglia [long-term resident macrophages of the brain]. Then, late in the disease, there's a resurgence of the HIV virus from the macrophages." Rappaport and his collaborators believe that this longstanding theory does not hold true, that the early invasion of HIV-infected macrophages are controlled and cleared away by the body's immune system.

Keyword: Miscellaneous; Sexual Behavior
Link ID: 5594 - Posted: 06.05.2004

PORTLAND, Ore. – A peculiar form of a gene mutation known to increase a person's risk for Parkinson's disease is puzzling doctors about how to counsel patients who have the anomaly. A study by researchers at the Oregon Health & Science University School of Medicine's Parkinson Center of Oregon, the University of Washington School of Medicine and the New York State Department of Health, Wadsworth Center, raises concerns about whether patients testing positive for a single mutation of the parkin gene, rather than the two mutations typically required for developing Parkinson's, can be accurately informed about their risks of developing the disease or passing it on to their children. The study represents "a call for getting more information about the gene," said John "Jay" G. Nutt, M.D., OHSU professor of neurology, and physiology and pharmacology, and Parkinson center director. "What are the clinical implications of finding this gene?" What's alarmed doctors is that in the clinical setting, the single mutation appears to be common: 18 percent of patients with early-onset Parkinson's disease – those diagnosed before age 40 – tested positive for parkin gene mutations, and of that group, 70 percent had only one mutation.

Keyword: Parkinsons; Genes & Behavior
Link ID: 5593 - Posted: 06.24.2010

Zeroing in on the genetic basis of language By Gary Marcus From our common ancestor with chimpanzees, it took only six million years, give or take, to develop the ability to speak. And, as we now know, the vast majority of our genetic material has been inherited unchanged. Language, and whatever else separates us from chimpanzees, has its origins in alterations to no more than about 1.5% of the nucleotides in the genome,1 a pretty neat trick, when you consider how handy talking can be. How did evolution pull it off? Some important clues have already come in, such as a recent study showing that there has been an important change in a gene relating to jaw structure that may have opened the way to the rapid expansion of the human brain,2 which is about four times the size of a chimp's. But size isn't everything. While a human-sized brain might be a necessary prerequisite for language, it is hardly likely to be sufficient. Whales and elephants have significantly larger brains than ours, but they don't have anything as complex as human language. Only with further evolutionary changes to our brains, perhaps in the last 100,000 years,3 did our ancestors begin to talk. © 2004, The Scientist LLC, All rights reserved.

Keyword: Language; Genes & Behavior
Link ID: 5592 - Posted: 06.24.2010

| By Nicole Johnston In the relative quiet following the outbreak of bovine spongiform encephalopathy in the United Kingdom, BSE returned to the headlines recently with a sole case found in the United States and new strains of BSE prion protein identified in France, Italy, and Japan. And, in May, French researchers said they found scrapie prion in sheep muscle, showing for the first time that prions have a direct path to the grocery store.1 While these events made headlines, other discoveries in the prion world also were occurring. Researchers have started, and only started, to get to the core of some fundamental questions involving prions. One of these is whether infectivity can be established in mammals using purified prion protein; the answer appears to be no. Investigators can isolate the protein from diseased animals, but they cannot reestablish infection in an uninfected animal. Researchers aren't sure why, but theories abound: The purified prion protein may not refold correctly, or perhaps other cellular factors act as accomplices. Answering the infectivity question would help confirm the role of prions in neurodegenerative diseases associated with mammalian transmissible spongiform encephalopathies (TSEs). "With mammals, the difficulty is that nobody has been able to take normal prion protein [PrPC], convert it in a test tube, and then infect animals," says biophysicist Witold Surewicz of Case Western Reserve University, Cleveland, Ohio. And that crucial missing link is what bothers prion skeptics such as Yale neurophysiologist Laura Manuelidis. "Nobody has shown that the protein is infectious." © 2004, The Scientist LLC, All rights reserved.

Keyword: Prions
Link ID: 5591 - Posted: 06.24.2010

An alternative treatment has been licensed in the UK to treat children with attention deficit hyperactivity disorder. Charmaine Wainwright, whose son Andrew - now 15 - was diagnosed with ADHD seven years ago, tells BBC News Online how atomoxetine has helped them. "I noticed something was different from an early age, probably even before he went to school. "I was working as a child-minder, and the other children would sit down and read, or paint, for hours on end. But he would do it for two minutes and then he'd be off." Andrew continued to behave in the same way when he went to school. It was only when Charmaine read a newspaper article about ADHD that she realised her son could be affected.

Keyword: ADHD
Link ID: 5590 - Posted: 06.04.2004