Matsumoto, Japan -- Researchers have demonstrated spread of senile amyloidosis from affected mice to their nursing offspring. The paper by Korenaga et al., "Transmission of amyloidosis in offspring of mice with AApoAII amyloidosis," appears in the March issue of The American Journal of Pathology and is highlighted on the cover of the Journal. Dementia can result from several disease mechanisms, including amyloidosis. Amyloidosis occurs when cellular proteins that normally float freely in the body form organized, nonfunctional aggregates, or fibrils, that cause cellular damage. This injury can lead to such disorders as Alzheimer's disease and Creutzfeld-Jakob disease, depending on the protein involved and where the fibrils accumulate. Genetics are known to be involved in these disorders, but researchers have also shown that injecting fibrils into susceptible mice accelerates disease onset. That led researchers guided by Dr. Xiaoying Fu to ask whether pups born to affected mothers also display accelerated disease. Using a mouse strain that carries a mutation for senile amyloidosis, Dr. Fu's group injected female mice with amyloid fibrils, to accelerate their disease, and then allowed the mice to mate and produce offspring. The mouse pups born to these mothers exhibited elevated levels of amyloid fibrils that increased with age. These fibrils were first seen in the intestines, spreading later to liver, spleen and other organs.

Keyword: Alzheimers
Link ID: 8846 - Posted: 04.29.2006

Helen Pearson A messy birth could be good for the baby's digestion. So say researchers in Germany, who have found evidence that baby mice squeezing through the birth canal swallow bacterial molecules that help their gut grow healthily. The finding suggests that kids born by caesarean might miss out. Swarms of friendly bacteria normally live in our guts, and cells lining the intestinal tubes do not attack them. Mathias Hornef at the University Clinic of Freiburg, Germany, and his colleagues, have found that, in mice at least, these intestinal cells 'learn' not to harm the bugs sometime around birth. The team extracted intestinal cells from mice embryos before birth and exposed them to a component of bacteria. The embryonic cells reacted and produced inflammatory molecules. But the same gut cells from one-day-old newborn mice or adult mice did not. Somehow, the cells in the more developed mice had learned to ignore the bacterial trigger. The researchers think that bacterial scraps naturally slopping around in the birth canal and mother's faeces are swallowed by the baby mice as they make their entry into the world. These molecules pass down into the gut, where they stimulate the gut cells; a single exposure is enough to teach the cells to tolerate friendly bugs in the future. ©2006 Nature Publishing Group

Keyword: Neuroimmunology
Link ID: 8845 - Posted: 06.24.2010

Blood clots in the brain may be a sign of increased risk of developing dementia, scientists suggest. The clots, known as cerebral emboli, were seen in people who had Alzheimer's disease or another form of dementia. The University of Manchester team who carried out the study say they could act as an early warning sign of the conditons. Dementia experts said the British Medical Journal finding was a significant and valuable discovery. The researchers monitored the occurrence of spontaneous blood clots in the brain in 170 patients - 85 with Alzheimer's disease and 85 with vascular dementia - compared them with groups of people of the same age. Forty per cent (32) patients with Alzheimer's and 37% (31) with vascular dementia had clots in just one hour of monitoring, compared to just 14 and 15% in the healthy groups (12 patients in each). The researchers, led by Professor Charles McCollum, said the finding suggested that the types of dementia have more in common than had been previously thought. They said more research was needed to investigate their finding further. Clive Ballard, director of research at the Alzheimer's Society which partially funded the study, said: "Blood clots in the brain can be detected in people at any age and their prevalence in people with Alzheimer's disease is a very significant finding. "The strong correlation between Alzheimer's and blood clots could lead to a way of detecting and treating Alzheimer's disease much earlier." (C)BBC

Keyword: Alzheimers
Link ID: 8844 - Posted: 04.28.2006

From The Economist print edition IF CANNABIS were unknown, and bioprospectors were suddenly to find it in some remote mountain crevice, its discovery would no doubt be hailed as a medical breakthrough. Scientists would praise its potential for treating everything from pain to cancer, and marvel at its rich pharmacopoeia—many of whose chemicals mimic vital molecules in the human body. In reality, cannabis has been with humanity for thousands of years and is considered by many governments (notably America's) to be a dangerous drug without utility. Any suggestion that the plant might be medically useful is politically controversial, whatever the science says. It is in this context that, on April 20th, America's Food and Drug Administration (FDA) issued a statement saying that smoked marijuana has no accepted medical use in treatment in the United States. The statement is curious in a number of ways. For one thing, it overlooks a report made in 1999 by the Institute of Medicine (IOM), part of the National Academy of Sciences, which came to a different conclusion. John Benson, a professor of medicine at the University of Nebraska who co-chaired the committee that drew up the report, found some sound scientific information that supports the medical use of marijuana for certain patients for short periods—even for smoked marijuana. This is important, because one of the objections to marijuana is that, when burned, its smoke contains many of the harmful things found in tobacco smoke, such as carcinogenic tar, cyanide and carbon monoxide. Yet the IOM report supports what some patients suffering from multiple sclerosis, AIDS and cancer—and their doctors—have known for a long time. This is that the drug gives them medicinal benefits over and above the medications they are already receiving, and despite the fact that the smoke has risks. © The Economist Newspaper Limited 2006.

Keyword: Drug Abuse
Link ID: 8843 - Posted: 06.24.2010

CAMBRIDGE, Mass.--MIT brain researchers have developed a "cocktail" of dietary supplements, now in human clinical trials, that holds promise for the treatment of Alzheimer's disease. For years, doctors have encouraged people to consume foods such as fish that are rich in omega-3 fatty acids because they appear to improve memory and other brain functions. The MIT research suggests that a cocktail treatment of omega-3 fatty acids and two other compounds normally present in the blood, could delay the cognitive decline seen in Alzheimer's disease, which afflicts an estimated 4 million to 5 million Americans. "It's been enormously frustrating to have so little to offer people that have (Alzheimer's) disease," said Richard Wurtman, the Cecil H. Green Distinguished Professor of Neuropharmacology at MIT, who led the research team. The study appears in the May 9 issue of Brain Research. Wurtman will present the research at the International Academy of Nutrition and Aging 2006 Symposium on Nutrition and Alzheimer's Disease/Cognitive Decline in Chicago on Tuesday, May 2. The three compounds in the treatment cocktail - omega-3 fatty acids, uridine and choline - are all needed by brain neurons to make phospholipids, the primary component of cell membranes.

Keyword: Alzheimers
Link ID: 8842 - Posted: 04.28.2006

Rowan Hooper An artificial insect "eye" could give surveillance cameras and surgical instruments the ability to see almost everything around them. The ultra-wide angle compound lens, which is about the size of an insect's eye, was developed by US researchers at the University of California, Berkeley. The 'back end' of the camera is yet to be produced. The eyes of insects such as bees and dragonflies are made up of tens of thousands of tiny components called ommatidia. These all point in different directions to give the insect a very wide field of vision. Inspired by this, Luke Lee and colleagues developed an artificial compound eye consisting of a moulded polymer resin dome filled with thousands of light-guiding channels, called waveguides, each topped with its own miniature lens. The artificial eye could be used to create surveillance cameras, cellphone cameras, and surgical endoscopes with a much wider field of vision, the researchers say. The whole eye is 2.5 millimetres in diameter. Each artificial ommatidia consists of a lens attached to a polymer waveguide that directs light towards the centre of the eye. © Copyright Reed Business Information Ltd.

Keyword: Vision; Robotics
Link ID: 8841 - Posted: 06.24.2010

Topping up levels of a hormone found naturally in the stomach could be a new way to treat obesity. Boosting oxyntomodulin limits appetite and raises activity levels at the same time - leading to speedy but healthy weight loss rates, a UK study suggests. The hormone tells us we are full after a meal, but the obese have less of it. The fact dieting tends to lead to reductions in activity often makes weight loss harder, the International Journal of Obesity study says. Professor Steve Bloom head of the Division of Investigative Science at Imperial College London said earlier studies had shown oxyntomodulin decreased appetite. But this was the first time it had been shown to increase physical activity levels. The fact that oxyntomodulin was naturally found in the body was also an advantage as it was unlikely to have unpleasant side-effects, he said. "It's not like one of those nasty drugs where you have to take some horrible chemical for years. It is naturally a occurring hormone. We are using the body's own method of limiting appetite." There are some conditions where people have high levels of the hormone after certain types of injuries to the gut, for example, and they tend to loose a lot of weight and stay very thin. And there do not appear to be any harmful effects of having high levels of oxyntomodulin, he said pointing to some medical conditions that produce this. The only side-effect appears to be sustained weight loss, he said (C)BBC

Keyword: Obesity; Hormones & Behavior
Link ID: 8840 - Posted: 04.27.2006

Among spotted hyenas, being a supermom is less about packing lunches, and more about packing a hormonal punch that gives her cubs a powerful head start. In a study appearing in the April 26 edition of the international science journal Nature, Michigan State University zoology professor Kay Holekamp and her former graduate student Stephanie Dloniak along with Jeffrey French from the University of Nebraska, report that high-ranking, dominant spotted hyena mothers pass to their offspring high levels of certain hormones that make cubs more aggressive and sexually vigorous – in other words more likely to survive, thrive and reproduce. The study shows that alpha females have higher levels of androgen during the final stages of pregnancy than lower-ranking group members. “What this means is that there are gifts a mom can give to her baby,” said Holekamp, who also is a recent recipient of a 2006 Guggenheim Fellowship for her work on hyenas. “She can manipulate her offspring’s behavior and help her kids to survive and reproduce successfully by transferring status-related traits via prenatal hormone exposure.” “This research sheds light on mammalian reproductive biology and helps us imagine how evolution might have produced such a bizarre product,” Holekamp said © 2006 Michigan State University Division of University Relations

Keyword: Hormones & Behavior; Aggression
Link ID: 8839 - Posted: 06.24.2010

The over-prescribing of the drug Ritalin to children diagnosed with alleged behavioural problems is a growing scandal, a leading scientist said yesterday. Baroness Greenfield, a neuro-scientist and director of the Royal Institution, said the overuse of the drug should be addressed as a matter of urgency. In a House of Lords debate on science and education, she said children's inability to pay attention might simply be the result of too much time spent on a computer screen, or watching television where only short attention spans were needed. "I am not proposing that we become information technology Luddites but we could be stumbling into a powerful technology, the impact of which we understand poorly at the moment," she said. "The problem with these drugs (such as Ritalin) is that they do not target a single trait such as mood, or concentration or wakefulness. "Drugs will manipulate in a very 'broad spectrum' way the chemicals in the brain that in turn could have both widespread and also long lasting effects." © Copyright of Telegraph Group Limited 2006.

Keyword: ADHD; Development of the Brain
Link ID: 8838 - Posted: 06.24.2010

LA JOLLA – The brain, that exquisite network of billions of communicating cells, starts to take form with the genesis of nerve cells. Most newborn nerve cells, also called neurons, must travel from their birthplace to the position they will occupy in the adult brain. Researchers at the Salk Institute for Biological Studies have identified a molecule expressed on the surface of certain migrating neurons that helps them find their correct position along on the way. Decreasing levels of that protein, an adhesion molecule called MDGA1, prevents neurons that normally make this protein from assuming their proper position, resulting in brain malformation, researchers report in the April 26th issue of the Journal of Neuroscience. As Dennis D. M. O'Leary, Ph.D., senior author of the study and a Professor in the Molecular Neurobiology Laboratory put it, "proper neuronal positioning is essential for development of appropriate wiring, which is in turn critical for establishing a normal, functioning nervous system." Neurons migrate throughout the brain, but migration is particularly important for development of part of the brain known as the cerebral cortex. The cortex sits like a skullcap over the rest of the brain and is responsible for sensory perception, higher-level reasoning, and, in humans, language. In mammals, the largest and evolutionarily newest part of the cortex, the neocortex, is recognized anatomically by its six horizontal layers.

Keyword: Development of the Brain
Link ID: 8837 - Posted: 06.24.2010

Scientists have discovered that a dominant hyena puts her cubs on the road to success before they are born by passing on high levels of certain hormones that make her budding young leaders more aggressive and sexually advanced. The report, published in the April 27 issue of Nature, is the first study in mammals to demonstrate a relationship between a female's social rank and her ability to influence her offspring's behavior through prenatal hormone transfer. Previously, this phenomenon had only been documented in birds. Michigan State University's Kay Holekamp, together with her colleagues, spent almost 10 years sampling androgen levels from free-ranging hyenas in Kenya. Androgens are hormones, such as testosterone, that control development of typically masculine characteristics like aggression, muscle development and sexual behavior. The team found that alpha females had higher androgen levels late in pregnancy when compared to the subordinate, pregnant females in the pack. Consequently, the cubs of the alpha females were more aggressive and exhibited more sexual play, characteristics that elevate the chances for life-success in both sexes. In hyena packs, male-female social roles are reversed from what is normally found in nature--that is, female hyenas are larger, more aggressive and dominate the group. They even have deceptively male-like genitalia, leading to the misconception that they are hermaphrodites.

Keyword: Hormones & Behavior; Aggression
Link ID: 8836 - Posted: 04.27.2006

By Elizabeth Pennisi Politicians, teachers, and even grandmothers chatting on telephones routinely use rambling sentences full of internal asides. The ability to piece together phrases in different combinations provides unlimited communicative capacity and helps distinguish humans from other species. But this ability may not be as unique as once thought. Starlings, 21-cm tall, iridescent black songbirds native to Eurasia and North Africa, can understand similarly structured songs, according to a new study. There's no rule that a sentence must convey only a single bit of information--all we need do is make it "recursive" by embedding additional phrases and clauses. For example, "Some birds sing complex songs," becomes more informative when written "Some birds, those that advertise their suitability as mates, sing complex songs." Linguists have thought that only humans could build and understand such complex sentences. Birds, on the other hand, merely add notes to the beginning or end of any particular string of sounds. Timothy Gentner, a neuroscientist at the University of California, San Diego, now challenges this assumption. Genter's team trained starlings, accomplished singers and mimics, to recognize recursive patterns. The researchers composed 16 artificial starling songs consisting of different "warbles" and "rattles" from a live bird. After several months of training, 9 of 11 starlings had learned to peck a lever for a food reward when they heard recursive variations of the phrase "warble, rattle." © 2006 American Association for the Advancement of Science.

Keyword: Language
Link ID: 8835 - Posted: 06.24.2010

Routine ultrasounds show that heavy drinkers who continue to imbibe after learning they are pregnant may carry fetuses with reduced skull and brain growth compared to those of abstainers or quitters, says a new study. Although the alcohol-exposed babies' growth remained within normal range, the findings reveal effects of drinking on the developing human brain. The study will appear in the May issue of Alcoholism: Clinical and Experimental Research. "What this tells us is that the earlier you abstain in a pregnancy, the better the outcome," said lead author Nancy Handmaker, a University of New Mexico clinical psychologist with expertise in maternal-fetal health. Alcohol use during pregnancy is a leading preventable cause of birth defects and developmental disabilities in the United States, according to the Centers for Disease Control and Prevention. Fetal Alcohol Spectrum Disorder -- which includes a range of cognitive, emotional and behavioral problems -- may be present in as many as one of every 100 births. The study authors obtained routine ultrasound data from 167 pregnant women who had reported a history of hazardous drinking before pregnancy. Of these, 97 were classified as heavy drinkers. The study compared the fetal growth measures among drinkers who quit after learning of their impending motherhood to those among women who continued to drink.

Keyword: Drug Abuse; Development of the Brain
Link ID: 8834 - Posted: 04.27.2006

Roxanne Khamsi Widespread wishful thinking has left some US states with gross underestimates of their obesity rates, a new study suggests. People generally misreport their height and weight to paint a slimmer picture of themselves when answering health-survey questions by phone, say researchers. And as a consequence, obesity levels in some southern states have been underestimated by as much as 50%. “This study can make a serious contribution to help us get to grips with the obesity epidemic,” comments Morgan Downey, director of the American Obesity Association in Washington, DC. He adds that the findings have “enormous implications on the policy level”. An increasing number of people in the US and other parts of the globe are clinically obese. Generally, doctors consider people who have a body mass index (BMI) higher than 30 units as obese. The body mass index is defined the weight in kilograms divided by the square of the height in metres. More than 300 million adults around the world are obese according to the World Health Organization. Experts note that the rates of obesity differ drastically around the world – in some countries such as Japan it remains below 5% while in urban areas of Samoa it rises above 75%. © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 8833 - Posted: 06.24.2010

Researchers have identified a protein that reins in the rogue activity of the molecules that make the amyloid-beta protein—which may prevent normal brain function in people with Alzheimer's disease. Their findings reveal a potentially powerful tool for designing novel Alzheimer's treatments. Amyloid beta-peptides are sticky, neurotoxic protein fragments that accumulate, kill nerve cells, and clump together to form the distinctive amyloid plaques in the brains of people with Alzheimer's disease. They are generated when a larger, normal protein called amyloid precursor protein (APP) is cleaved or split in a series of events. A protein complex called the presenilin complex is responsible for the final cleavage event. Presenilin complexes are thought to cause an unusual form of protein cleavage in which selected membrane proteins are split in a region that crosses cell membranes. This previously unrecognized form of protein cleavage is essential for several normal signaling processes. The same presenilin complex also generates amyloid-beta from APP. The presenilin cleavage that generates amyloid-beta may be a physiological process unrelated to signaling. In fact, it may just be a way to remove unneeded protein stubs from cellular membranes. © 2006 Howard Hughes Medical Institute.

Keyword: Alzheimers
Link ID: 8832 - Posted: 06.24.2010

By STEPHANIE SAUL When GlaxoSmithKline began talking to Roche three years ago about commercializing the prescription diet drug Xenical, the timing could not have been better for Steven L. Burton. An executive with Glaxo's consumer heath care division, Mr. Burton had been overweight for years, carrying 270 to 275 pounds on his 6-foot-1 frame. Those measurements put him well into the "obese" category, a condition shared by 30 percent of American adults. And his doctor had just issued a stern warning to Mr. Burton. "I didn't think seriously about a serious weight-loss program until I had a couple of kids and I had a doctor who was telling me pretty bluntly that it was time to do something about my blood pressure and high cholesterol and weight for the sake of my kids," he said recently. "That's pretty motivating." Now Mr. Burton, 47, has the job of motivator in chief as Glaxo prepares to market an over-the-counter version of Xenical. During the last three years, while ramping up the marketing plans, he has been using the drug himself. And while he does not envision himself posing for the before and after shots in a diet ad, he can offer personal testimony to the drug's potential benefits. In his three years on Xenical, Mr. Burton said he has dropped to 210 pounds from 270, and kept it off. Copyright 2006 The New York Times Company

Keyword: Obesity
Link ID: 8831 - Posted: 04.26.2006

New research attempting to shed light on the evergreen question--just how do male and female brains differ?--has found that timing is everything. In a study involving over 8,000 males and females ranging in age from 2 to 90 from the across the United States, Vanderbilt University researchers Stephen Camarata and Richard Woodcock discovered that females have a significant advantage over males on timed tests and tasks. Camarata and Woodcock found the differences were particularly significant among pre-teens and teens. "We found very minor differences in overall intelligence. But if you look at the ability of someone to perform well in a timed situation, females have a big advantage," Camarata said. "It is very important for teachers to understand this difference in males and females when it comes to assigning work and structuring tests. To truly understand a person's overall ability, it is important to also look at performance in un-timed situations. For males, this means presenting them with material that is challenging and interesting, but is presented in smaller chunks without strict time limits." The findings are particularly timely, with more attention being paid by parents, educators and the media to the troubling achievement gap between males and females in U.S. schools. "Consider that many classroom activities, including testing, are directly or indirectly related to processing speed," the authors wrote.

Keyword: Sexual Behavior; Intelligence
Link ID: 8830 - Posted: 04.26.2006

EVANSTON, Ill. --- Two teams of researchers at Northwestern University have found a novel pathological hallmark of the neurodegenerative disease amyotrophic lateral sclerosis (ALS) at the molecular level. The neurologists and biochemists show how and why the mutated superoxide dismutase (SOD1) protein, which is associated with a familial form of ALS, becomes vulnerable and prone to aggregation and also provide evidence linking disease onset with the formation of intermolecular aggregates. The findings, which have implications for new therapeutics for the devastating disease, were published online this week in two related papers by the Proceedings of the National Academy of Sciences (PNAS). ALS is a progressive paralytic disorder caused by degeneration of motor neurons in the brain and spinal cord. The cause and development (pathogenesis) of the fatal disease are not known, and there is no effective treatment. Fifteen years ago, an international consortium led by Teepu Siddique, M.D., Les Turner ALS Foundation/Herbert C. Wenske Foundation Professor at Northwestern's Feinberg School of Medicine, mapped the first ALS gene to chromosome 21. Subsequently, they found that mutations in the SOD1 gene are responsible for 20 percent of familial (inherited) ALS cases. Siddique and his colleagues also made the first ALS transgenic mouse models. Although more than 100 types of a single mutation in the SOD1 gene have been identified and multiple lines of the mouse models developed, a key question remains to be answered: How does the genetic mutation alter this incredibly stable protein to make it so toxic that it kills motor neurons and causes neurodegenerative disease?

Keyword: ALS-Lou Gehrig's Disease
Link ID: 8829 - Posted: 04.26.2006

When kids try to do impossible things, like attempting to get into a tiny toy car, sit on a dollhouse chair, or slide down a miniature model of a playground slide, Judy DeLoache not only chuckles, she also investigates why. The psychology professor at the University of Virginia says toddlers treating scale models like full-sized objects is one of the most comical behaviors she and her colleagues observe at their Child Study Center. "They're funny, quite funny to watch, but we think that they also tell us something important about early development," says DeLoache, who is also a visiting professor at New York University. She says these errors are perfectly normal and occur most often in kids 18 to 30 months old. "It's a very vivid demonstration that things that are so fundamental to the behavior of adults or older children can really go dramatically awry when you've got a very immature brain underlying the behavior," she explains. As she wrote in Scientific American Mind magazine, learning to think symbolically — grasping the concept that one thing can represent another — is a challenge to young minds and a critical part of early brain development. © ScienCentral, 2000-2006.

Keyword: Development of the Brain; Language
Link ID: 8828 - Posted: 06.24.2010

Dartmouth researchers are learning more about the effects of alcohol on the brain. They've discovered more about how the brain works to mask or suppress the impact that alcohol has on motor skills, like reaching for and manipulating objects. In other words, the researchers are learning how people process visual information in concert with motor performance while under the influence of alcohol. "We found that the brain does a pretty good job at compensating for the effect that alcohol has on the brain's ability to process the visual information needed to adjust motor commands," says John D. Van Horn, a research associate professor of psychological and brain sciences and the lead author on the paper. "Alcohol selectively suppresses the brain areas needed to incorporate new information into subsequent and correct motor function." For the study, eight people, ranging in age from 21-25, were asked to maneuver a joy stick both while sober and when experiencing a blood alcohol level of 0.07 percent (just below the legal definition of intoxicated). Brain activity during this task was captured using functional magnetic resonance imaging, known as fMRI. The study was published online in the journal NeuroImage on March 6, 2006. © 2006 Trustees of Dartmouth College

Keyword: Drug Abuse
Link ID: 8827 - Posted: 06.24.2010