Anna Petherick Ever felt unlucky in love? You’re surely better off than the nematode worm Caenorhabditis elegans. When the Hawaiian and Bristol strains of this worm breed with one another, their offspring pay the price: a genetic incompatibility kills a quarter of the offspring. Yet the genes responsible for this brutal outcome seem to be conserved by natural selection. Researchers have found that embryos of C. elegans unlucky enough to be missing one particular gene, called zeel-1, die early in development if their male parent delivered a metaphorical bomb into their embryotic life in the form of a compound produced from an incompatible version of another gene, peel-1, in his sperm. Hannal Seidel and her colleagues at Princeton University in New Jersey, discovered this quirk of nature by accident, when they crossed worms for a different experiment. Discovering that one in four embryos were dying, they suspected genetics might be to blame — patterns of gene inheritance mean that some conditions can affect exactly 25% of offspring. The researchers set to work matching up different worms with each other to see what had happened to the offspring. C. elegans is almost always hermaphroditic, and almost always reproduces on its lonesome. But occasionally, one of these worms will produce a true male offspring (never a female). This male can then go forth to have sex with another worm. This happens as infrequently as one in a 1,000 generations. © 2008 Nature Publishing Group

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 11196 - Posted: 06.24.2010

US scientists claim a drug can reverse some of the early symptoms of Alzheimer's disease - with the first effects seen within 10 minutes. The Journal of Neuroinflammation reports how the memory of an 81-year-old man improved sharply after etanercept was injected into his spine. His wife described it as her husband being "put back to where he was". But UK experts warned that a single success did not prove that the drug would work for every dementia patient. An ageing population means a substantial increase in the numbers of people suffering Alzheimer's disease. Some studies have suggested that too much of a body chemical called tumour necrosis factor-alpha may be at least partly to blame for the advance of the condition. Etanercept, which is licensed for use as a rheumatoid arthritis drug, works to block this body chemical. Scientists from the University of California at Los Angeles, and the University of Southern California, have already published a study which suggested that this could benefit Alzheimer's patients. In previous studies, they noticed that injecting the drug into the neck spine seemed to deliver almost immediate effects - so set out to test this on just one patient, a former doctor in the early stages of the disease. Before the drug, they measured his performance on cognitive tests, and performed poorly, unable to remember the name of the doctor treating him, the date, or the state in which he lived. He could not perform simple mental arithmetic, or name more than two animals. (C)BBC

Keyword: Alzheimers
Link ID: 11195 - Posted: 01.10.2008

By LINDA A. JOHNSON -- A rare genetic variation dramatically raises the risk of developing autism, a large study showed, opening new research targets for better understanding the disorder and for treating it. Research into the causes of autism has focused on genetic causes because so many families have multiple children with the disorder. Thus far, only about 10 percent of autism cases have a known genetic cause. Boston-area researchers estimate the gene glitch they've identified accounts for another 1 percent of cases. They found a segment of a chromosome which has genes linked to brain development and various developmental disorders was either missing or duplicated far more often in autistic people. The defect was inherited in some cases, but more often the result of a random genetic accident. The results from the Autism Consortium study, released online Wednesday by the New England Journal of Medicine, confirm those of smaller studies by U.S. and Canadian research groups in the past year. The consortium verified its findings by checking two other DNA databases. "They really did nail it," said Dr. Andrew Zimmerman, director of the Kennedy Krieger Institute's Center for Autism & Related Disorders in Baltimore, who was not involved in the research. © Copyright 1996-2008 The Washington Post Company

Keyword: Autism; Genes & Behavior
Link ID: 11194 - Posted: 06.24.2010

NEW findings seem to contradict one of the most widely accepted assumptions about ageing: that the human brain is at its most powerful between the ages of 18 and 26. Scientists have discovered that intelligence, instead of peaking in our youth, remains stable and in some respects gets sharper as we grow older. The researchers found that verbal skills continued to increase for at least two decades beyond the age of 20, while arithmetic ability remained constant. Their work suggests that many assumptions made by employers, policymakers and educational institutions about ageing need to be rethought. "Verbal ability appears to keep increasing over time," said Lars Larsen, a psychologist at the University of Aarhus, Denmark, who led the research. In the study, Dr Larsen obtained the records of 4300 US ex-servicemen who had been given a battery of intelligence tests when they joined the military at the age of about 20. The same servicemen were tested again two decades later. Dr Larsen's research involved carrying out a meticulous comparison of the two sets of data. The results, published in Intelligence, a peer-reviewed academic journal, show that the real changes in intelligence are more marked and more complex than had been realised. Copyright 2008 News Limited

Keyword: Intelligence; Language
Link ID: 11193 - Posted: 01.10.2008

Anna Salleh -- Neanderthals probably froze to death in the last ice age because rapid climate change caught them by surprise without the tools needed to make warm clothes, finds new research. Ian Gilligan, a postgraduate researcher from the Australian National University argues his case in the current issue of the journal World Archaeology. By the time some Neanderthals developed sewing tools it was too little too late, said Gilligan. Neanderthals began to die out just before the last glacial maximum, 35,000 to 30,000 years ago and were replaced by modern humans. Previous studies have argued that one of the key reasons for this is that modern humans had better hunting tools, providing them with the extra food they needed to survive the cold. But Gilligan disagrees that the development of hunting tools was so important to modern humans' survival over the Neanderthals. For a start, he argues, Neanderthals were already successful hunters, surviving in Europe and Eurasia for over 100,000 years. Most of the tools supposed to have given modern humans the edge over Neanderthals were actually more useful for making warm clothes. © 2008 Discovery Communications

Keyword: Evolution
Link ID: 11192 - Posted: 06.24.2010

By Lisa Stein Want to lose weight but lack the willpower to just say no to fatty foods and sweets? Help may be on the way. The first clinical trials of an experimental weight-loss drug show that it helps curb appetite—and burn more fat—even at low doses. Researchers report in the journal Cell Metabolism that taranabant, developed by drug giant Merck, is the second drug found to be successful in fighting flab by blocking cannabinoid receptors (responsible for the psychological effects of marijuana a.k.a. Cannabis sativa) in the brain's reward circuitry. "The effects of marijuana on appetite have been known for millennia from its medicinal and recreational use," said study author Steven Heymsfield of Merck Research Laboratories. "The ingredient responsible stimulates cannabinoid receptors. When you block the cannabinoid system with an antagonist like taranabant, you suppress appetite." The first indication that the cannabinoid-1 (CB1) receptor might be a prime weight-loss target came during studies of an earlier drug called rimonabant (manufactured by sanofi-aventis), which is now available as a diet aid in several European countries but has yet to receive the Food and Drug Administration's nod for use in the U.S. © 1996-2007 Scientific American Inc.

Keyword: Obesity; Drug Abuse
Link ID: 11191 - Posted: 06.24.2010

By Greg Miller The ability to suppress distracting or distressing memories helps people cope with everyday life, yet neuroscientists know little about how it works. Now researchers have gained some clues from a study that combined hypnosis and functional magnetic resonance imaging (fMRI) to investigate changes in brain activity as volunteers suppressed--and later recalled--memories of a recently viewed movie. Some people can be made to suppress a particular memory by hypnotic suggestion, an effect called posthypnotic amnesia. Hoping to take advantage of this phenomenon, neuroscientist Yadin Dudai of the Weizmann Institute of Science in Rehovot, Israel, and colleagues had subjects watch a movie depicting a young woman going about her daily routine--making meals, talking on the phone, rollerblading with friends, and so on. A week later, the volunteers returned to the lab and, under hypnosis, were instructed to forget the movie until they heard the phrase "Now you can remember everything." As the researchers had hoped, the hypnosis triggered memory suppression. After the subjects woke up, they took a quiz about the activities of the woman in the movie. They performed no better than chance, answering only half of the yes-no questions correctly. Immediately afterward, the volunteers heard the magic phrase and took the quiz again. This time they averaged about 80% correct, the same as a control group that wasn't susceptible to posthypnotic amnesia. © 2008 American Association for the Advancement of Science

Keyword: Learning & Memory
Link ID: 11190 - Posted: 06.24.2010

By Charles Q. Choi Just as Nana and Papa help take care of the kids, senior birds have now been seen for the first time behaving like grandparents. The new findings could shed light on how grandparenting — rare in the animal kingdom except in humans — develops. In a very small number of mammal species other than humans — such as pilot whales and some monkeys — researchers have occasionally seen older adults engage in what might be grandparenting. Still, this behavior remains largely overlooked outside humans, explained molecular ecologist David Richardson of the University of East Anglia in England. For more than 10 years, Richardson and his colleagues have investigated the Seychelles warbler (Acrocephalus sechellensis), once one of the world's rarest birds due to human interference. Conservation efforts have now helped rescue this tropical songbird from the edge of extinction. The small island the researchers worked on is also the nesting site of half a million seabirds. The constant rain of bird droppings "means a hat is a must!" Richardson recalled. In addition, "although the island is incredibly beautiful, it can also be full of mosquitoes, especially in the jungle. In some wet years you would be lucky to get away with 300 to 400 bites a day. Fortunately, there is no human malaria, so it is not life threatening." © 2008 LiveScience.com.

Keyword: Sexual Behavior
Link ID: 11189 - Posted: 06.24.2010

A little alcohol combined with a healthy active lifestyle may be the best recipe for a longer life. A European Heart Journal study suggests the combination can cut the risk of heart disease. A Danish team found people who led an active lifestyle were less prone to heart disease - but the risk was cut still further if they drank moderately. However, UK experts warned people should not be encouraged to drink, as too much alcohol can be very damaging. The researchers followed nearly 12,000 men and women for nearly 20 years, during which 1,242 died from ischaemic heart disease (IHD). Overall, they found people who did not drink or take any exercise had the highest risk of heart disease - 49% higher than people who either drank, exercised or did both. When comparing people who took similar levels of exercise, they found that those who drank moderately - one to 14 units of alcohol a week - were around 30% less likely to develop heart disease than non-drinkers. This finding held good for people who were completely inactive, through to those who took vigorous regular exercise - with the overall risk declining as exercise levels increased. Non-drinkers who were physically active had a 31%-33% reduced risk of IHD compared to physically inactive non-drinkers. But their reduced risk was dwarfed by physically active people who drank at least one drink a week - their risk was up to 50% lower than that of physically inactive non-drinkers. Past research has suggested that alcohol consumption may decrease the risk of heart disease by increasing the levels of "good" cholesterol and possibly thinning the blood. It was a similar story when the researchers looked at deaths from all causes: physical activity appeared to reduce the risk, while moderate drinkers fared better than their abstemious peers across all physical activity levels. (C)BBC

Keyword: Drug Abuse
Link ID: 11188 - Posted: 01.09.2008

New approaches to the treatment of tinnitus - a buzzing or ringing in the ears - are being pioneered and may hold the promise of a future cure. Over a third of the UK population will suffer from tinnitus at some point in their lives. For 600,000 of these people the condition will become so severe that it seriously impedes the quality of their lives. Sufferers can become agitated and forgetful. They are sometimes unable to sleep, sustain relationships, or hold down employment. Every year there are many reports of tinnitus driving sufferers to suicide. There is no respite from the constant noise and no cure. Tinnitus is often described as a 'mild ringing' in the ears. But for Kate Cook, a busy working mother of two and presenter of the documentary Longing for Silence, the effects of the condition are debilitating. She has had a high pitched whistle inside her head for 25 years and the impact on her life is huge. It never goes away and when she is tired or stressed the volume swells to unbearable levels. "After a long day you have got this incredible noise inside you. A whistling, squeaking, almost physical sensation in your ears. That is when you feel really really lonely. And because it is a silent symptom to everyone around you, there is this hopeless feeling of being on my own with it," says Kate. Like many tinnitus sufferers, she feels frustrated by the lack of help on offer. "There is a complete vacuum of information for people like me. Because it is not fatal people think it is not that bad. But it ruins lives." (C)BBC

Keyword: Hearing
Link ID: 11187 - Posted: 01.09.2008

By Elizabeth Quill Each fall, millions of monarch butterflies wing it from their birthplaces in eastern North America to a small winter retreat in the mountains of central Mexico. Scientists have long puzzled at how the insects navigate the unfamiliar journey, which can span up to 3000 kilometers. Now researchers have exposed the cogs and gears that make a monarch's biological clock tick, timekeeping that they say is necessary for successful southward navigation. Scientists believe monarchs follow the sun like a compass. But this is easier said than done. Because the sun appears to rise and fall each day, the insects must constantly adjust to its movements, lest they quickly lose their way. In 2003, Steven Reppert, a neurobiologist at the University of Massachusetts Medical School in Worcester, showed that butterflies use an internal timepiece to help them fly in the right direction (ScienceNOW, 22 May 2003). In a pair of new studies, Reppert and his colleagues suggest that the connection between the clock and the compass relies on light-absorbing proteins called cryptochromes. First discovered in plants, cryptochromes help synchronize the internal clock--or circadian rhythm--in flies and mice (Science, 27 November 1998, p. 1628). © 2008 American Association for the Advancement of Science

Keyword: Biological Rhythms; Animal Migration
Link ID: 11186 - Posted: 06.24.2010

By Karla Gale NEW YORK (Reuters Health) - Administration of orexin-A, a naturally occurring brain neurotransmitter, counteracts the intellectual deficits and altered brain metabolism induced by sleep deprivation in monkeys, new research findings show. Orexin-A was tested because of its know specific brain activity in controlling sleep processes in mammals, lead author Dr. Sam A. Deadwyler told Reuters Health. Orexin-A is released by neurons in the brain, the scientists explain in the Journal of Neuroscience, and orexin-A receptors are located on neurons in many brain regions affected by sleep and sleep deprivation. Deadwyler, a neurobiologist at Wake Forest University in Winston-Salem, North Carolina, and his team worked with eight monkeys trained to perform an intellectual task to test short-term memory. The effect of orexin-A on the animals' performance was analyzed after a normal 12-hour sleep cycle and after being kept awake for 30 to 36 continuous hours. Brain metabolism was evaluated by F18-fluorodeoxyglucose PET scanning. When the monkeys were alert, orexin-A did not improve test performance. In fact, at the highest concentration of orexin-A, intellectual functioning worsened. However, when the monkeys were deprived of sleep, a low- or high-dose of orexin-A significantly improved the animals' test performance. SOURCE: Journal of Neuroscience, December 26, 2007. © 1996-2007 Scientific American Inc.

Keyword: Sleep
Link ID: 11185 - Posted: 06.24.2010

By LAURAN NEERGAARD, AP Medical Writer WASHINGTON - Those Type A go-getters aren't the only ones stressing their hearts. Nervous Nelsons seem to be, too. Researchers reported Monday that chronic anxiety can significantly increase the risk of a heart attack, at least in men. The findings add another trait to a growing list of psychological profiles linked to heart disease, including anger or hostility, Type A behavior, and depression. "There's a connection between the heart and head," said Dr. Nieca Goldberg of the New York University School of Medicine, a spokeswoman for the American Heart Association who wasn't involved in the study. "This is very important research because we really are focused very much on prescribing medicine for cholesterol and lowering blood pressure and treating diabetes, but we don't look at the psychological aspect of a patient's care," she added. Doctors "need to be aggressive about not only taking care of the traditional risk factors ... but also really getting into their patients' heads." The research was published Monday by the Journal of the American College of Cardiology. Everybody's anxious every now and then. At issue here is not the understandable sweaty palms before a big speech or nervousness at a party, but longstanding anxiety — people who are socially withdrawn, fearful, chronic worriers. It's a glass-half-empty personality.

Keyword: Emotions; Stress
Link ID: 11184 - Posted: 06.24.2010

By JANE E. BRODY Scott McCredie is a Seattle-based health and science writer who says he “discovered” what he calls “the lost sense” of balance after he watched in horror as his 67-year-old father tumbled off a boulder and disappeared from sight during a hike in the Cascades. Though his father hurt little more than his pride, Mr. McCredie became intrigued by what might have caused this experienced hiker, an athletic and graceful man, to lose his balance suddenly. His resulting science-and-history-based exploration led to a book, “Balance: In Search of the Lost Sense,” published last June by Little, Brown. Noting that each year one in three Americans 65 and older falls, and that falls and their sometimes disastrous medical consequences are becoming more common as the population ages, Mr. McCredie wonders why balance is not talked about in fitness circles as often as strength training, aerobics and stretching. He learned that the sense of balance begins to degrade in one’s 20s and that it is downhill — literally and figuratively — from there unless steps are taken to preserve or restore this delicate and critically important ability to maintain equilibrium. Vertigo, which can be caused by inner ear infections, low blood pressure, brain injuries, certain medications and some chronic diseases, is loss of balance in the extreme. Anyone who has experienced it — even if just from twirling in a circle — knows how disorienting and dangerous it can be. Really, without a sense of balance, just about everything else in life can become an insurmountable obstacle. Copyright 2008 The New York Times Company

Keyword: Miscellaneous
Link ID: 11183 - Posted: 06.24.2010

LOS ANGELES - Autism cases in California continued to climb even after a mercury-based vaccine preservative that some people blame for the neurological disorder was removed from routine childhood shots, a new study found. Researchers from the state Department of Public Health found the autism rate in children rose continuously during the 12-year study period from 1995 to 2007. The preservative thimerosal hasn’t been used in childhood vaccines since 2001, but is used in some flu shots. Doctors say the latest study adds to existing evidence refuting a link between thimerosal exposure and autism risk and should reassure parents that the disorder is not caused by vaccinations. If there was a risk, they said, autism rates should have dropped between 2004 and 2007. The findings show “no evidence of mercury poisoning in autism” since there was no decline in autism rates even after the elimination of thimerosal, said Dr. Eric Fombonne, an autism researcher at Montreal Children’s Hospital who had no role in the research. © 2008 The Associated Press.

Keyword: Autism; Neurotoxins
Link ID: 11182 - Posted: 06.24.2010

By TARA PARKER-POPE For people with chronic pain, relief comes with a tradeoff. Bed rest means missing out on life. Drugs take the edge off, but they also dull the senses and the mind. But there’s another potential option: implantable stimulators that blunt pain with electrical impulses. In this case, the tradeoff is living with a low-grade buzzing sensation in place of the pain. The devices, which are implanted near the spine, are not widely used. They are expensive, don’t work for everyone and rarely offer complete relief. Industry officials estimate that fewer than 10 percent of eligible patients opt for the treatment. But when they do work, they can be life-changing. Carolyn Stewart, 45, of Clifton, N.J., has lived with chronic back pain since she was 18, when she had surgery after a car accident. Then four years ago, a procedure for a collapsed lung accidentally resulted in nerve damage that caused excruciating pain. “I just want to sleep normally and not have pain that wakes me up every 20 minutes,” she said. Ms. Stewart has been using pain drugs to cope, but side effects, including fatigue and constipation, only add to her discomfort. A few years ago she did a “test drive” of a spinal cord stimulator and experienced a significant drop in her pain. Insurance troubles delayed a permanent implant, but this month she is finally undergoing surgery to attach the device to her spinal cord. “It’s not going to be 100 percent,” she said. “But I will be happy with a 50 percent change.” Copyright 2008 The New York Times Company

Keyword: Pain & Touch
Link ID: 11181 - Posted: 06.24.2010

By Emily Lyons When strangers ask her for directions, Karen Kostyal responds quickly. She has lived around Washington about 30 years and has a well-rooted sense of the area. Nonetheless, the Alexandria resident says, "my husband usually cuts in," supporting the stereotype that men feel their sense of orientation and direction is superior. "No question," says Buzz Smith, Kostyal's husband. "It's not that I don't get lost. [But] I can give directions . . . better than my wife can." That assertion may be contestable, but there are well-documented differences in how men and women get from Point A to Point B -- perhaps giving a scientific root to timeworn jokes about women being batty drivers and men never admitting (though committing) error. Studies over the past decade have shown that women are likelier to rely on landmarks and visual cues, and men on maps, cardinal directions (such as north and south) and gauges of distance. "Women are more dependent on a surrounding frame," says Luc Tremblay, an assistant professor of physical education and health at the University of Toronto, who has led studies on the matter. If landmarks change, women are more apt to notice and question their sense of orientation. "Men are capable of relying on another source of information alone," Tremblay says. While some scientists theorize that hormones account for navigational differences between the sexes, Tremblay thinks the answer may lie in the inner ear. © 2008 The Washington Post Company

Keyword: Sexual Behavior
Link ID: 11180 - Posted: 06.24.2010

Marlowe Hood, -- Tiny nerves crisscrossing the spine can bypass crippling injuries recently written off as irreversible, scientists reported in a study published Monday. Experiments conducted on mice at the University of California in Los Angeles showed for the first time that the central nervous system can rewire itself to create small neural pathways between the brain and the nerve cells that control movement. This startling discovery could one day open the way to new therapies for damaged spinal cords and perhaps address conditions stemming from stroke and multiple sclerosis, according to the study. Normally, the brain relays messages that control walking or running via neural fibers called axons. When these long nerves are crushed or severed -- in a road crash or sports accident, for example -- these lines of communication are cut, resulting in reduced movement or paralysis. "Not long ago, it was assumed that the brain was hard-wired at birth and that there was no capacity to adapt to damage," explained neurobiologist Michael Sofroniew, who led the research. © 2008 Discovery Communications

Keyword: Regeneration
Link ID: 11179 - Posted: 06.24.2010

Rachel Courtland By mating blind fish from distant underwater caves, researchers have bred offspring that can see. The results, published this week in Current Biology 1, show that the two populations took different evolutionary paths to blindness. “We’ve basically shown that these different populations have converged upon the same outward appearance independently, and that they use different genes to do it,” says Richard Bolowsky of New York University. The blind fish, called Astyanax mexicanus , live in isolated limestone caves in northeast Mexico. Over hundreds of millennia of living in darkness, the fish, which have a sighted ancestor, accumulated genetic mutations that affect eye development, and so lost their sight. Today some 29 different varieties of the blind Mexican fish live in isolated caves. Researchers have long wondered whether they all lost their sight the same way or not. Bolowsky and his assistants descended into the caves and fished out different blind populations to cross in the lab. If the fish had the same developmental mutations, the researchers reckoned they would produce blind offspring. Instead, the experiment produced a number of fry with functioning eyes; in the most successful pairing, 40% of hybrid fry could see. The results suggest fish from different caves have mutations that don’t overlap. © 2008 Nature Publishing Group

Keyword: Vision; Evolution
Link ID: 11178 - Posted: 06.24.2010

In experiments done in lab and animal studies, a breakdown in proper cell development has been shown to cause brain-specific stem cells to become starter seeds for aggressive brain tumors called glioblastoma multiforme, according to research from a team of researchers. This developmental breakdown is caused by an error in methylation, one of the cell's primary methods of controlling the extent to which genes are expressed. In laboratory studies and animal models of brain cancer, reversing this error repaired the breakdown, restoring the normal neural cell development pathway. The findings, which appear in the January 2008, issue of Cancer Cell, could increase basic understanding of brain tumor biology and lead to the development of targeted therapies for brain cancer. "The discovery of a link between tumor stem-like cells and expression control is both novel and exciting," said NCI Director John Niederhuber, M.D. "These results bring new clarity to how all aspects of the genome's function, regulation, and structure can be perturbed in the development of cancer." Many researchers have come to believe that the activity of a small group of stem-like tumor starter cells, or tumor-initiating cells with stem-like properties (TICs) may be one of the main reasons that cancer develops. Like normal stem cells, TICs are able to self-renew; unlike stem cells , TICs give rise to cells that develop into tumors, instead of differentiating into normal tissue. TICs have been reportedly found in tumors in a number of organs, including the breast, colon, lung, and brain.

Keyword: Miscellaneous
Link ID: 11177 - Posted: 01.08.2008