A team of researchers led by cognitive scientist Elizabeth Bates, a professor at the University of California, San Diego, has developed a novel new brain imaging technique that produces maps that “light up” the relationship between the severity of a behavioral deficit and the voxels (similar to pixels in computer images) in the brain that contribute the most to that deficit. Discovery of the new technique, known as Voxel-based Lesion-Symptom Mapping (VLSM), was reported in the April 21 issue of Nature Neuroscience. According to Bates, who is known for her research on the brain and how it is organized to process language, VLSM will give researchers an invaluable new tool for pinpointing the specific areas of the brain that are most crucial for normal functioning during critical brain activities, starting with the measures of language comprehension and production that were used for the first demonstration in Nature Neuroscience, but moving on to many different language and non-language functions. To view or download the paper, which includes color VLSM brain maps, please visit: “This is a new brain mapping technique to be used with structural rather than functional magnetic resonance imaging scans (fMRI) that locate brain damage for individual patients,” said Bates. “It is an important breakthrough because it is a bridge, a tool, to bring two completely different traditions in brain research – lesion-behavior mapping and fMRI’s -- into alignment.” Copyright ©2001 Regents of the University of California

Keyword: Brain imaging
Link ID: 3720 - Posted: 06.24.2010

A major study has confirmed the value of potential markers for identifying people with Alzheimer's disease. Scientists at the National Institute of Mental Health (NIMH) found that levels of two key indicators in spinal fluid distinguished clinically diagnosed Alzheimer's patients from controls with 89-92 percent efficiency. This matches or exceeds current clinical diagnostic methods, such as doctor's evaluation of medical history, cognitive testing, and brain scans. However, the potential telltale signs, or biomarkers, won't be ready for use as predictive and diagnostic tools until completion of long-term studies now underway. Trey Sunderland, M.D., chief, NIMH Geriatric Psychiatry Branch, and colleagues, report on their study -- which included both direct examination of 203 patients and controls and a meta-analysis of world literature -- in the April 23, 2003 Journal of the American Medical Association. "We're hopeful that biomarkers will eventually be developed to help detect incipient illness in younger people who are at risk but who may not yet show any symptoms," said Sunderland. "Clues from biochemical, genetic and brain imaging studies could point to new possibilities for preventive interventions." The NIMH study examined cerebrospinal fluid (CSF) levels of two protein fragments, hallmarks of the disease process, found in brains of Alzheimer's victims: beta-amyloid, which clumps together to form brain-damaging plaques, and tau, which strangles neurons in tangled filaments.

Keyword: Alzheimers
Link ID: 3719 - Posted: 06.24.2010

By GINA KOLATA For nearly nine months, doctors and researchers have been struggling with an intractable problem: how could two large high-quality studies come to diametrically different conclusions about menopause, hormone therapy and heart disease? The question arose in July, when scientists saw data from a large federal study called the Women's Health Initiative, which was ended early when it became clear that a widely used hormone-replacement drug, Prempro, had risks, including heart attacks, that exceeded its benefits. That finding directly contradicted previous studies showing that the hormones reduced heart disease risk — in particular, the Nurses' Health Study, a large research effort that has been going on for years. Copyright 2003 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 3718 - Posted: 06.24.2010

Scientists report for the first time that “baby” teeth, the temporary teeth that children begin losing around their sixth birthday, contain a rich supply of stem cells in their dental pulp. The researchers say this unexpected discovery could have important implications because the stem cells remain alive inside the tooth for a short time after it falls out of a child’s mouth, suggesting the cells could be readily harvested for research. According to the scientists, who published their findings online today in the Proceedings of the National Academy of Sciences, the stem cells are unique compared to many “adult” stem cells in the body. They are long lived, grow rapidly in culture, and, with careful prompting in the laboratory, have the potential to induce the formation of specialized dentin, bone, and neuronal cells. If followup studies extend these initial findings, the scientists speculate they may have identified an important and easily accessible source of stem cells that possibly could be manipulated to repair damaged teeth, induce the regeneration of bone, and treat neural injury or disease. “Doctors have successfully harvested stem cells from umbilical cord blood for years,” said Dr. Songtao Shi, a scientist at NIH’s National Institute of Dental and Craniofacial Research (NIDCR) and the senior author on the paper. “Our finding is similar in some ways, in that the stem cells in the tooth are likely latent remnants of an early developmental process.”

Keyword: Stem Cells
Link ID: 3717 - Posted: 06.24.2010

Researchers find important similarity among Alzheimer's, Parkinson's, Huntington's and other degenerative diseases Irvine, Calif. -- UC Irvine researchers have discovered an important similarity in the causes of cell degeneration and death in diseases such as Alzheimer's, Parkinson's, Huntington's, type II diabetes and CJD, suggesting that a single therapy could combat these different ailments. UCI molecular biologists Charles Glabe and Rakez Kayed found that small toxic molecules believed to trigger cell damage in these diseases have a similar structure. The study, which appears in the April 18, 2003 issue of Science, implies that these molecules, called toxic soluble oligomers, share parallel functions, which makes them suitable targets for new drugs or vaccines that could halt progression of many degenerative diseases. "This discovery will help focus attention on what may be the primary mechanism for degeneration and cell death," said Glabe, professor of molecular biology and biochemistry. "Whatever makes these molecules toxic is likely to be the same for all of the different types of oligomers in the different diseases."

Keyword: Alzheimers; Huntingtons
Link ID: 3716 - Posted: 04.22.2003

HOUSTON – A gene therapy developed by researchers at Baylor College of Medicine has apparently cured diabetes in mice by inducing cells in the liver to become beta cells that produce insulin and three other hormones. "It's a proof of principle," said Dr. Lawrence Chan, professor of medicine and molecular and cellular biology as well as chief of the division of diabetes, endocrinology and metabolism at the College. "The exciting part of it is that mice with diabetes are 'cured.' " In the research, which is described in a report in Nature Medicine's online edition today, Chan and his colleagues used the NeuroD gene, a transcription factor that induces the liver to produce cells that make insulin and the three hormones associated with the pancreas' endocrine system.

Keyword: Obesity
Link ID: 3715 - Posted: 06.24.2010

The brain's miserly habits can make your head spin By Eric Haseltine Your brain is a taskmaster that often makes individual neurons perform multiple operations at the same time. Like any other overworked laborers forced to juggle too many responsibilities, overwrought nerve cells are prone to make mistakes. Experiment 1 Focus on the star in the center of Figure A. Slowly move your head toward the page, then away from it. The rotation you perceive is called the Pinna-Brelstaff illusion. Vision researchers Filippo Pinna and Gavin Brelstaff theorize that illusory rotation arises from the brain's strategy of making certain neurons responsible for detecting both the orientation and the direction of movement of visual lines and curves. Neurons in the visual cortex of the brain are organized into subgroups, each of which responds best to lines oriented at a specific angle. Neurons that "prefer" the particular angle of an object viewed at any given moment are more active than those preferring other orientations. A subgroup of visual neurons gets most excited when a line with a preferred orientation is in motion and the direction of that motion is at a right angle to the line's orientation. © Copyright 2003 The Walt Disney Company

Keyword: Vision
Link ID: 3714 - Posted: 06.24.2010

Life-altering surgery on rise By Christine Rook Lansing State Journal More than ever, Americans turn to surgery to control their weight. The number of weight-related operations has more than tripled nationwide in the past eight years. These are not cosmetic quick fixes. They include everything from stomach stapling to permanently bypassing several feet of intestine. They are costly and invasive and mean lost time from work, strict diets and the understanding that even with surgery a person still might end up obese. Why, then, are people signing up? Because for the morbidly obese - people whose weight is slowly killing them - surgery isn't an easy out. It's the only out. webmaster@lsj.com Copyright 2003

Keyword: Obesity
Link ID: 3713 - Posted: 04.20.2003

Possible link between this orphan disease and neurodegenerative disorders considered | By Brendan A. Maher A movement disorder can start as a twinge. A child's leg turns in while walking. Writing becomes difficult, painful. For many, these types of diseases--broadly termed dystonias--progress no further than persistent muscle cramps. Yet in many children affected by rare, heritable, early-onset dystonia, a generalized movement disorder called torsion dystonia develops as well. The disorder can affect the entire body: Opposing muscles work against each other, twisting the posture, causing repetitive movements, or contorting arms and legs into unnatural positions. Oftentimes, the earlier in life symptoms appear, the worse they get. To uncover the roots of this dominant trait, which has only 30% to 40% penetrance, researchers spent more than 15 years studying afflicted, diverse families and a population of Ashkenazi Jews to zero in on a responsible mutation: a three-basepair deletion in DYT1 that appears exactly the same across ethnic groups.1 Recent efforts to elucidate the function for torsinA--the protein this gene encodes--reveal that torsins may act as molecular chaperones, altering protein folding and clearing aggregates from living cells. In worms, torsins alleviate engineered poly-glutamine clumps,2 and in cell culture, torsinA suppresses a-synuclein aggregation.3 These results and others reveal ties to troublesome neurodegenerative disorders such as Parkinson, Huntington, and Alzheimer disease. Protein aggregates are hallmarks of these diseases, but their role remains controversial. Likewise, torsinA's role in clearing the aggregates is murky, and such clumps are not even found in patients with dystonia. Yet, some draw parallels between torsion dystonia and Parkinson disease: Uncontrollable movements are common to both, and some treatments, including deep-brain stimulation, seem to ameliorate symptoms, even though dystonia is not a neurodegenerative disease. ©2003, The Scientist Inc.

Keyword: Movement Disorders; Genes & Behavior
Link ID: 3712 - Posted: 06.24.2010

The discovery could help understand fat absorption Scientist have discovered a gene that makes people more likely to absorb fat. They were looking at why some people are more prone to diseases linked to excessive consumption of fat. But they say it may help understand how too much fat can lead to obesity, diabetes, high blood fat levels and heart attacks. It may and aid the development of new treatments. An international team of researchers looked at the genetic causes of severe fat malabsorption in three rare diseases, chylomicron retention disease (CMRD), Anderson Disease and CMRD with Marinesco Sjogren syndrome, a neuromuscular disorder. The genetic mutations in the three disorders mean that a protein called Sar1b, which is required for all dietary fat absorption, cannot work properly. Scientists from Imperial College London and the Hammersmith Hospital studied families from across the world and found all those affected by the three disorders had the same genetic mutation. (C) BBC

Keyword: Obesity; Genes & Behavior
Link ID: 3711 - Posted: 04.19.2003

Talk is cheap, but it can tax your memory Bruce Bower Law-enforcement officials typically solicit descriptions of criminals from eyewitnesses, often just after an offense has occurred. It stands to reason that thorough accounts by those who saw what happened will help investigators round up the likeliest suspects. Eyewitnesses can then pick the criminals out of a lineup. When crime-scene interviewing had its first brush with memory research in 1990, however, the results proved disturbing. A series of laboratory studies found that memories for a mock criminal's face were much poorer among eyewitnesses who had described what the perpetrator looked like shortly after seeing him, compared with those who hadn't. Psychologist Jonathan W. Schooler of the University of Pittsburgh, who directed the studies, dubbed this effect "verbal overshadowing of visual memories." His paper's subtitle put it more bluntly: "Some things are better left unsaid." Not among scientists, though. Discussion generated by Schooler's results ushered in a wave of research examining how eyewitnesses can find themselves, as he later quipped, "at a loss from words." Studies have confirmed that, at least under certain circumstances, verbal descriptions impair memories for faces and other hard-to-describe perceptions, such as the taste of a fine wine or the sound of a person's voice. Recent investigations, described in the December 2002 Applied Cognitive Psychology , extend what's known about verbal overshadowing and offer potential tactics for counteracting this memory-sapping effect. However, no one yet knows the full range of perceptions subject to verbal overshadowing or its implications for various eyewitness-interviewing techniques. From Science News, Vol. 163, No. 16, April 19, 2003, p. 250. Copyright ©2003 Science Service

Keyword: Learning & Memory; Language
Link ID: 3710 - Posted: 06.24.2010

By EMILY EAKIN In the middle of the 17th century, Spinoza took on Descartes and lost. According to Descartes' famous dualist theory, human beings were composed of physical bodies and immaterial minds. Spinoza disagreed. In "The Ethics," his masterwork, published after his death in 1677, he argued that body and mind are not two separate entities but one continuous substance. As for Descartes' view of the mind as a reasoning machine, Spinoza thought that was dead wrong. Reason, he insisted, is shot through with emotion. More radical still, he claimed that thoughts and feelings are not primarily reactions to external events but first and foremost about the body. In fact, he suggested, the mind exists purely for the body's sake, to ensure its survival. Copyright 2003 The New York Times Company

Keyword: Emotions
Link ID: 3709 - Posted: 04.19.2003

Last month, the Department of Health and Human Services (HHS) conducted a site visit of an investigator at the University of California, San Francisco (UCSF), whose studies of sex workers have been the target of a recent inquiry by Congress. Although there is no hard evidence that the inquiry and the site visit are linked, the events have shaken researchers at UCSF and some at the National Institutes of Health (NIH). The controversy centers on work by AIDS researcher Tooru Nemoto, whose projects include preventing HIV infection in Asian sex workers and in men who are planning or have had a sex change operation. HHS officials inquired about how UCSF was managing Nemoto's grants from the department in early January. In late March, four officials from NIH and another HHS agency, the Substance Abuse and Mental Health Services Administration (SAMHSA) spent 2 days at UCSF asking about procedures and going "all over San Francisco" to hear scientific talks by Nemoto, says UCSF grants manager Joan Kaiser. She says that UCSF officials "haven't heard back" but assume the grants were in compliance. UCSF officials thought no more of it until they learned last week about a 13 March e-mail memo from a House of Representatives staffer. Roland Foster of the House Subcommittee on Criminal Justice, Drug Policy, and Human Resources chaired by Mark Souder (R-IN), raised concerns about two NIH-funded studies of sex workers--one of them Nemoto's. The memo argues that by attempting to protect the health of sex workers, the studies "seek to legitimize the commercial sexual exploitation of women." Foster's memo asks for the names of study section members who approved the grants and the scores they gave. Foster says he played "no role" in the UCSF site visit but is "interested in what may be found." Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 3708 - Posted: 06.24.2010

A gene that stops different species of fruit flies from interbreeding is evolving faster than other genes, according to researchers at the University of California, Davis, and the University of Cambridge in England. The findings may help scientists understand how new species evolve from existing ones. The offspring of matings between different species are often sterile, like mules, or don't form viable animals at all. This incompatibility is important for evolution, as new species form when they are genetically cut off from their close relatives. Over 60 years ago, geneticist Theodosius Dobzhansky proposed that matings between closely related species would cause harmful or lethal genetic effects in the offspring, preventing interbreeding and driving the two species apart. Daniel Barbash, a postgraduate researcher at UC Davis, together with postgraduate researchers Dominic Siino and Aaron Tarone at UC Davis and John Roote, a genetics researcher at Cambridge University, studied a gene called Hybrid male rescue (Hmr) in the fruit fly Drosophila melanogaster and three close relatives.

Keyword: Sexual Behavior; Evolution
Link ID: 3707 - Posted: 04.19.2003

It’s just a sugar pill. It has no active medicinal content, and yet sometimes patients get well after taking it. In scientific communities it’s known as a placebo. Its power has puzzled scientists and baffled pharmaceutical industries for a long time. The improvements that patients experience from taking placebos is known as the placebo effect. Placebos are commonly used in clinical tests of new drugs. Andrew Leuchter, professor of psychiatry at the University of California Los Angeles’s Neuropsychiatry Institute, says that when doctors test a new medical treatment or when pharmaceutical companies develop a new medication, “they always end up comparing it to a placebo, so they can see if this new medication that they’re developing is better than no treatment.” The placebo effect is so strong that new medications are generally not considered to be effective unless they are proven to work better than placebos. Although scientists are not sure about how the placebo works, recent studies have illustrated that it’s power is hard to deny. Leucher and his colleagues witnessed and studied the placebo effect in patients being treated for major depression. In a study published in the American Journal of Psychiatry, the researchers explain that by using a technique called quantitative electro encephalography or QEEG, they measured and studied patient’s brain activity and showed for the first time that the placebo effect is not just in the mind but that it’s a real change, a real “physical phenomenon” in the brain. © ScienCentral, 2000-2003.

Keyword: Pain & Touch; Depression
Link ID: 3706 - Posted: 06.24.2010

Cannabis extract is to be trialled in a new South West study into Parkinson's Disease. The Peninsula Medical School is carrying out the study, which starts in May and will involve 24 patients from Cornwall and Devon. The study will be based at Derriford Hospital in Plymouth and will look at whether the drug can help reduce the side effects of some existing medication. Participants will be using a cannabis derivative called Cannador, which will be in capsule form. Parkinson's is one of the most common neurological diseases in older people. It is a progressive, degenerative, neurological condition for which there is currently no cure. Sufferers find increasing difficulty in moving their arms and legs. (C) BBC

Keyword: Parkinsons; Drug Abuse
Link ID: 3705 - Posted: 04.18.2003

Laughing gas is becoming a popular recreational drug, say doctors, who warn of potential health risks from its use. A survey in New Zealand found one in eight students at a university had used nitrous oxide recreationally. Cannisters of nitrous oxide are used in some domestic appliances - for example cream dispensing containers - and can be bought easily at hardware stores. Inhaling the gas can produce hallucinations and disorientation - and overuse has been linked to long-term health problems. The survey, published in the medical journal The Lancet, involved 1,782 first-year students at the University of Auckland. More than half of the students said they were aware that nitrous oxide could be used recreationally. Approximately 12% said they had used it recreationally at some point, and 3% - 39 students - said they were regular users. (C) BBC

Keyword: Drug Abuse
Link ID: 3704 - Posted: 04.18.2003

La Jolla, Calif.—A cellular receptor that balances the accumulation of fat and fat burning in the body may be a new target for anti-obesity and cholesterol-fighting drugs, according to a Salk Institute study. The study, published in the April 18 issue of Cell, identified the function of this key receptor for the first time. The receptor, called PPARd, was found to regulate how fat is used and could point the way to new treatments for obesity as well as its associated lethal medical complications: type II diabetes, cardiovascular disease, hypertension and atherosclerosis. Professor Ronald M. Evans, the March of Dimes Chair in Developmental and Molecular Biology at the Salk Institute and Howard Hughes Medical Institute investigator, and his team found that stimulating PPARd -- short for peroxisome proliferators-activated receptor -- depleted fat deposits in mice, while mice deficient in PPARd were prone to obesity.

Keyword: Obesity
Link ID: 3703 - Posted: 06.24.2010

— Exposure to continuous white noise sabotages the development of the auditory region of the brain, which may ultimately impair hearing and language acquisition, according to researchers from the University of California, San Francisco. According to the scientists, the young rats used in their study were exposed to constant white noise that is relevant to the increasing, random noise encountered by humans in today's environment. They theorize that their findings could aid in explaining the increase in language-impairment developmental disorders over the last few decades. The researchers, which included Howard Hughes Medical Institute medical student fellow Edward Chang and otolaryngology professor Michael Merzenich at the University of California at San Francisco, published their findings in the April 18, 2003, issue of the journal Science. ©2003 Howard Hughes Medical Institute

Keyword: Hearing
Link ID: 3702 - Posted: 06.24.2010

Injections appear to treat mouse multiple sclerosis. HELEN R. PILCHER Injections of cultured adult brain stem cells seem to have helped mice with a form of multiple sclerosis to recover from paralysis. Researchers hope that similar therapies may one day treat human sufferers of the disease. Cells injected into the bloodstream found their way to the animals' brains, where they repaired damaged and inflamed areas. Four out of 15 mice with paralysed back legs moved normally after treatment1. "It's a great recovery," says team member Angelo Vescovi of the Stem Cell Research Institute at the San Raffaele Hospital in Milan, Italy. The other 11 mice retained only minor tail paralysis. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Multiple Sclerosis; Stem Cells
Link ID: 3701 - Posted: 06.24.2010