ITHACA, N.Y. -- A five-year study has found that lead is harmful to children at concentrations in the blood that are typically considered safe. Reporting in the latest issue (April 17) of The New England Journal of Medicine , two Cornell University scientists say that children suffer intellectual impairment at a blood-lead concentration below the level of 10 micrograms per deciliter (mcg/dl) -- about 100 parts per billion -- currently considered acceptable by the Centers for Disease Control and Prevention (CDC). "We also found that the amount of impairment attributed to lead was most pronounced at lower levels," says Richard Canfield, lead author of the journal paper and a senior researcher in Cornell's Division of Nutritional Sciences. The study followed 172 children in the Rochester, N.Y., area whose blood lead was assessed at 6, 12, 18, 24, 36, 48 and 60 months and who were tested for IQ at both 3 and 5 years of age. The study was conducted by researchers at Cornell, the Cincinnati Children's Hospital, the University of Rochester, the National Institutes of Health and the University of Washington.

Keyword: Neurotoxins; Development of the Brain
Link ID: 3700 - Posted: 04.17.2003

Researchers at the University of California, San Diego (UCSD) School of Medicine have found that the levels of a pituitary hormone that increases testosterone are enhanced after exposure to bright light in the early morning. The findings suggest that light exposure might serve some of the same functions for which people take testosterone and other androgens. One of the study's authors, Daniel Kripke, M.D. UCSD professor of psychiatry, added "the study also supports data that bright light can trigger ovulation in women, which is also controlled by luteinizing hormone (LH), the pituitary hormone we studied." Published in the current issue of the journal Neuroscience Letters (341, 2003, 25-28), the study looked at LH excretion following bright light exposure (1,000 lux) from 5-6 a.m. each morning for five days in 11 healthy men ages 19-30. The same group of men had their LH measured again after exposure to a placebo light (less than 10 lux) from 5-6 a.m. for five days.

Keyword: Hormones & Behavior; Biological Rhythms
Link ID: 3699 - Posted: 04.17.2003

No clear choices on which fish are best Olivia Wu, Chronicle Staff Writer So you jack up the amount of fish you eat, pump the omega-3s, and make your heart healthier and happier than it's ever been. But at the same time, are you accumulating toxic levels of mercury and making a mess of your brain and nerves? It depends, scientists say. What kind of fish, how large the fish are and your individual tolerance for mercury are all factors in choosing a mercury-safe seafood diet. You can eat fish often -- if you choose carefully. ©2003 San Francisco Chronicle

Keyword: Neurotoxins; Development of the Brain
Link ID: 3698 - Posted: 06.24.2010

Exclusive from New Scientist Print Edition Combining the most potent neurotoxin known to man and a protein from the Mediterranean coral tree could deliver a long-lasting treatment for the chronic pain that afflicts millions of people, including cancer patients. The neurotoxin in question is botulinum toxin, perhaps better known as Botox, the treatment that has smoothed out the wrinkles on many a celebrity forehead. But it is also used to treat an increasing range of medical conditions. The neurotoxin, whose effects can last for months, works by blocking the release of the neurotransmitters that relay the "contract now" message from nerves to muscles. The machinery that is knocked out is actually found inside most cells, but the toxin only affects the neurons that control muscles. This is because of a targeting sequence in the toxin that only permits it to bind to muscle cells. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 3697 - Posted: 06.24.2010

By LAWRENCE K. ALTMAN UNITED NATIONS, — Monkeys experimentally infected with a new coronavirus have developed an illness similar to the mysterious human respiratory disease SARS, and it is now almost certain that the coronavirus causes the disease, a World Health Organization official said here today. Dr. David L. Heymann, executive director in charge of communicable diseases for W.H.O., said the agency "is 99 percent sure" that SARS is caused by the new coronavirus based on the monkey experiments in the Netherlands. Experiments on animals are necessary because the lack of an effective treatment for SARS and the relatively high death rate make it unethical to conduct such experiments on humans. Preliminary findings show that the monkeys developed an illness resembling SARS after the coronavirus was put in their nostrils. Some monkeys developed pneumonia, and examination of their lungs under a microscope showed that the coronavirus caused a pattern of lung damage similar to what affected humans have suffered. Copyright 2003 The New York Times Company

Keyword: Animal Rights
Link ID: 3696 - Posted: 06.24.2010

New research at North Carolina State University’s College of Veterinary Medicine indicates that cloned pigs can have the same degree of variability in physical appearance and behavior as normally bred animals. Two separate studies show that while clones are genetically identical to the original animal, the similarities end there. This dispels the commonly held notion that cloned animals retain the physical and behavioral attributes of the animal from which they were cloned. The research was conducted by Dr. Jorge Piedrahita, professor of molecular biomedical sciences at NC State, and colleagues at Texas A&M University. His study on cloned pig behavior, which appears in Applied Animal Behaviour Science, is the first published research on the behavior of cloned mammals. The study on cloned pig physiology, which appears in Biology of Reproduction, is the first study on clone physiology that included control subjects.

Keyword: Genes & Behavior
Link ID: 3695 - Posted: 06.24.2010

Exclusive from New Scientist Print Edition Women who navigate around 3D computer-generated environments for a living - or even for fun - are having their style cramped by ultra-narrow computer displays and graphics software that favours men. Female architects, designers, trainee pilots and even computer gamers should be given much wider computer screens, a team of computer scientists from Carnegie Mellon University in Pittsburgh, Pennsylvania, and Microsoft's research lab in Redmond, Washington, told a computer usability conference in Fort Lauderdale, Florida, last week. Wider screens and more realistic 3D animations, they say, will boost women's spatial orientation and 3D map-reading skills to match those of their male counterparts. It may sound like sexual prejudice, but it seems that men's much-debated ability to navigate slightly better than women applies in virtual environments as well as the real world. And on average, says Microsoft computer scientist Mary Czerwinski, men are quicker to create a mental map of an environment and orient themselves within it. © Copyright Reed

Keyword: Sexual Behavior; Learning & Memory
Link ID: 3694 - Posted: 06.24.2010

You don't see as much as you think you do By Carey Goldberg, Globe Staff, Look up and around you, then back at these words. How much did you see of your surroundings? Pretty much all of it, and in rich detail, right? Wrong. In recent years, a rash of experiments, spurred by new technology, have demonstrated that people often take in far less of the world around them than previously thought. Tests have found that subjects miss even major changes right before their eyes - say, the sudden disappearance of an airplane's jet engine, or a woman's bright scarf. © Copyright 2003 Globe Newspaper Company.

Keyword: Vision
Link ID: 3693 - Posted: 06.24.2010

NewScientist.com news service Partial memory blackouts after drinking binges could contribute to future alcoholism, say researchers, because drinkers may fill in the blanks with rosy memories. Experiments involving moderate alcohol intake showed that drinkers who had previously suffered partial memory loss had poorer memories than drinkers who had not. Questionnaires also revealed that the memory loss drinkers also had more optimistic attitudes about the effect alcohol had upon them. These results, and others from the same study, led the scientists at the University of Texas in Austin to conclude that drinkers experiencing "fragmentary blackouts" are more likely to misremember drinking experiences and then fill in the gaps with positive beliefs. And this would increase the likelihood of them drinking heavily in the future, the researchers say. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Learning & Memory
Link ID: 3692 - Posted: 06.24.2010

By JANE E. BRODY I pick up my morning newspaper and flip directly to the sports pages because almost every article on Page 1 is about the war. I turn on the radio to get the traffic and weather reports only to hear that American troops have been hit by fire from their own side or that they have killed Iraqi civilians trying to escape the war zone. Throughout New York City and elsewhere, there are subtle reminders — police officers carrying gas masks, soldiers with rifles at airports and toll booths — that any of us at any time could be struck by another terrorist attack equal to the devastation of Sept. 11, or worse. Bankruptcy or insurmountable debt seems to be looming everywhere, resulting in growing unemployment and reductions in services vital to our quality of life. Copyright 2003 The New York Times Company

Keyword: Stress
Link ID: 3691 - Posted: 06.24.2010

By DENISE GRADY A pill to make you thin: it has long been a dieter's dream. But despite intense, if not desperate interest from the public — 60 million Americans are obese — and eagerness from drug companies to meet the demand, efforts to develop weight-loss drugs have been disappointing. The human body seems to guard its fat stores jealously, and attempts to outsmart the system often fail outright or backfire, causing dangerous side effects. Recently, in what might seem an odd twist, researchers have been studying weight loss in people taking two drugs already on the market, but approved for a completely different use, to treat epilepsy. Both drugs, Zonegran and Topamax, are also used to prevent migraine headaches. Zonegran is made by Elan Pharmaceuticals, and Topamax by Ortho-McNeil, a unit of Johnson & Johnson. The weight-loss potential of both drugs was discovered almost by accident, when people taking them for epilepsy or migraines noticed that they were dropping weight without trying. Copyright 2003 The New York Times Company

Keyword: Obesity; Epilepsy
Link ID: 3690 - Posted: 06.24.2010

PHILADELPHIA -- Opening a new front in the battle against Alzheimer's disease, scientists at the University of Pennsylvania have found that a protein long associated with the disease inflicts grave damage in a previously unimagined way: It seals off mitochondria in affected neurons, resulting in an "energy crisis" and buildup of toxins that causes cells to die. This pathway, the first specific biochemical explanation for pathologies associated with Alzheimer's, is detailed in the April 14 issue of the Journal of Cell Biology. While the normal function of the amyloid precursor protein (APP) remains unknown, senior author Narayan G. Avadhani and his colleagues have determined that a mere 50-amino-acid stretch of the protein wreaks havoc by essentially starving mitochondria and the cells they nourish. "We found that when APP leaves the nucleus, it can be directed both to mitochondria and to the endoplasmic reticulum," said Avadhani, professor of biochemistry and chair of the Department of Animal Biology in Penn's School of Veterinary Medicine. "APP has an acidic, negatively charged region that causes it to jam irreversibly while traversing protein transport channels in the mitochondrial membrane. This hampers, and eventually completely blocks, mitochondria's ability to import other proteins and produce cellular energy."

Keyword: Alzheimers; Apoptosis
Link ID: 3689 - Posted: 04.15.2003

A woman's heavy episodic drinking during pregnancy triples the odds that her child will develop alcohol-related problems at age 21, according to a new study that has been tracking young adults since before their birth. The paper, published today in the April issue of the Archives of General Psychiatry, points to fetal alcohol exposure as a risk factor in a person developing alcohol-related problems at 21. This relationship persists even when other demographic factors, including family history of alcohol problems, prenatal exposure to nicotine and other drugs, and other aspects of the family environment, are taken into account, said the University of Washington's John Baer and Ann Streissguth, the paper's lead authors. "It appears that exposure to alcohol during pregnancy can predict the amount of alcohol problems that a child will have in adulthood," said Baer. "It takes us a step further in understanding why some people have alcohol problems.

Keyword: Drug Abuse; Development of the Brain
Link ID: 3688 - Posted: 04.15.2003

Keyhole operations to deal with scar tissue inside the abdomen have surprisingly little effect on pain, says a study. Patients, particularly women with endometriosis, develop "adhesions" - patches of scar tissue that can attach to major organs and distort them. These are often a source of extreme pain - but there is debate about the benefits of operating to remove them. Doctors suspect much of the relief experienced by patients following "adhesiolysis" - is unconnected. Researchers in the Netherlands studied 100 women with chronic abdominal pain caused adhesions. Half were given adhesiolysis operations, and most reported some improvement in their symptoms. But the other half enjoyed an equal improvement, despite having only a diagnostic laparoscopy. (C) BBC

Keyword: Pain & Touch; Hormones & Behavior
Link ID: 3687 - Posted: 04.14.2003

NewScientist.com news service A caffeine and alcohol cocktail similar to an Irish coffee could prevent severe brain damage in stroke victims, new research has revealed. The experimental drug, called caffeinol, has the potency of two cups of strong coffee and a small shot of alcohol. When injected into rats within three hours of an artificially stimulated stroke, brain damage was cut by up to 80 per cent. Neurologist James Grotta and colleagues from the University of Texas-Houston Medical School have also now demonstrated the safety of caffeinol in a small pilot study in patients who suffered ischaemic strokes, when the artery to the brain becomes blocked and cuts off the blood supply. © Copyright Reed Business Information Ltd.

Keyword: Stroke; Drug Abuse
Link ID: 3686 - Posted: 06.24.2010

A young bird that goes hungry too often isn't likely to grow up to be an avian Caruso, a new study finds. Later in life, these males warble meager repertoires, potentially compromising chances with the opposite sex. Female birds often look for extravagant plumage or brightly colored beaks when selecting a mate. That's because these features can hint at a male's overall vigor (ScienceNOW, 3 April ). Females also prefer males with virtuoso singing, but researchers haven't understood how musical ability might reflect health. One possible explanation, the so-called nutritional stress hypothesis, is that males that go hungry at key times early in life, when the brain structures associated with singing are developing, end up with lame songs. Females looking for the best mate, the theory goes, would do well to avoid males who have fallen on such hard times. To test this idea, Kate Buchanan, a biologist at Cardiff University in Wales, and her colleagues reared 48 male and female European starlings. Half of the birds were fed around the clock as much as they could eat. The other half was fed at irregular intervals for 80 days, beginning approximately 1 month after they hatched. Nine months later, males that experienced nutritional stress spent less time singing and they produced shorter song bouts. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Stress; Sexual Behavior
Link ID: 3685 - Posted: 06.24.2010

Saint Louis University study suggests new approach to treating obesity ST. LOUIS -- Obese people are not getting critical chemical signals to their brains that tell them to stop eating, findings from Saint Louis University suggest. The review of research was published in the March issue of Current Pharmaceutical Design. Normally, a protein called leptin is released from fat cells and hitches a ride across the blood vessels that feed the brain, known as the "blood-brain barrier." The protein then is in the right place to tell the brain that the body has had enough to eat, to eat less or to burn calories faster. However, among those who are obese, the brain doesn't seem to be getting the message. This could be because the blood-brain barrier doesn't properly transport the leptin or because the brain isn't interpreting the signals properly.

Keyword: Obesity
Link ID: 3684 - Posted: 04.14.2003

And sheds light on motivation and reward in male sexual behavior How does the body know it has had an ejaculation? And why does it care? Anatomically, it is more complex than it seems, says the University of Cincinnati scientist who last year identified the spinal cord cells that control ejaculation in rats and the neural pathway by which signals travel between the body's sexual organs to the brain. At the Experimental Biology 2003 meeting in San Diego, Dr. Lique Coolen reviews work her laboratory has done in understanding ejaculation and then discusses her current work in how chemical signals on this pathway contribute to pleasure and reward, key elements in sexual behavior. Dr. Coolen is this year's recipient of the American Association of Anatomists' C. J. Herrick Award in Comparative Neuroanatomy. Scientists had known for years that there must be a group of cells in the spinal center that control ejaculation. Following spinal cord injury that prevents sensation from reaching the brain, humans and other animals remain able to achieve erection and ejaculation upon stimulation. But the location of this spinal ejaculation generator remained a mystery until last August when Dr. Coolen and a postdoctoral fellow in her laboratory, Dr. William Truitt, reported their findings in Science . Dr. Coolen had targeted the lumbar spinothalamic neurons in the lower back because these neurons appeared active only after ejaculation and not during sexual arousal or mounting. When the researchers used a highly selective toxin to destroy the thalamic neurons in adult male rats, the rats appeared not to notice. They continued their sexual interest and behavior, including penetration of the female. But they no longer had ejaculations, confirming that these were the cells the researchers had been hunting.

Keyword: Sexual Behavior
Link ID: 3683 - Posted: 04.14.2003

CHAPEL HILL -- University of North Carolina at Chapel Hill scientists working with colleagues at Duke University have discovered that even after dopamine and norepinephrine systems are disrupted in specially modified laboratory animals, cocaine still provides reinforcing "rewards" to animals that ingest it. Their study, reported Saturday (April 12) at a meeting of the American Society for Pharmacology and Experimental Therapeutics in San Diego, shows the brain's ability to process the addictive drug is more complex than many researchers believed. It also brings medical science a bit closer to the day when effective therapies will be available to treat cocaine addiction, the scientists say. "What we call transporters normally take up biological chemicals known as neurotransmitters such as dopamine and return them to neurons to be reprocessed," Dykstra said. "When transporters are blocked, however, dopamine will remain in the synapses of nerve cells."

Keyword: Drug Abuse
Link ID: 3682 - Posted: 04.14.2003

By NICHOLAS WADE Deep in the recesses of the human heart, lurking guiltily beneath the threshold of consciousness, there may lie a depraved craving — for the forbidden taste of human flesh. The basis for this morbid accusation, made by a team of researchers in London, is a genetic signature, found almost worldwide, that points to a long history of cannibalism. The signature is one that protects the bearer from infection by prions, proteins that can be transmitted in infected meat and attack the nerve cells of the brain. Prions can be acquired from eating infected animals, as in the case of the mad cow disease that in 1996 spread to people in England, but they spread even more easily through eating infected humans. This fact is known from study of the Fore, a tribe in the eastern highlands of Papua New Guinea that started to practice ritual cannibalism at the end of the 19th century. Dr. D. Carleton Gajdusek, who later received a Nobel Prize for his work, noticed that the Fore were being devastated by a neurodegenerative disease known as kuru. He linked it with their practice of eating the brains of their dead in mortuary feasts. When the feasts were banned by Australian authorities in the mid-1950's, the incidence of kuru declined, and no cases have appeared in anyone born after that time. Copyright 2003 The New York Times Company

Keyword: Prions; Genes & Behavior
Link ID: 3681 - Posted: 06.24.2010