By Robert Lanza and Nadia Rosenthal Stem cells raise the prospect of regenerating failing body parts and curing diseases that have so far defied drug-based treatment. Patients are buoyed by reports of the cells' near-miraculous properties, but many of the most publicized scientific studies have subsequently been refuted, and other data have been distorted in debates over the propriety of deriving some of these cells from human embryos. Provocative and conflicting claims have left the public (and most scientists) confused as to whether stem cell treatments are even medically feasible. If legal and funding restrictions in the U.S. and other countries were lifted immediately, could doctors start treating patients with stem cells the next day? Probably not. Many technical obstacles must be overcome and unanswered questions resolved before stem cells can safely fulfill their promise. For instance, just identifying a true stem cell can be tricky. For scientists to be able to share results and gauge the success of techniques for controlling stem cell behavior, we must first know that the cells we are studying actually possess the ability to serve as the source, or "stem," of a variety of cell types while themselves remaining in a generic state of potential. But for all the intensive scrutiny of stem cells, they cannot be distinguished by appearance. They are defined by their behavior. © 1996-2004 Scientific American, Inc.

Keyword: Stem Cells; Regeneration
Link ID: 5549 - Posted: 06.24.2010

New research may provide a key insight into how the brain switches from sleep to wakefulness. Studying the brains of narcoleptic dogs, they've identified a class of neurons that seems to determine when the animals are alert and attuned to their surroundings. During sleep, the body goes limp and the mind drifts off. Researchers regard these processes as two separate phenomena, and to study them, they often turn to specially bred dogs with narcolepsy--a disorder characterized by uncontrollable sleepiness. Like many human narcoleptics, the dogs also suffer bouts of cataplexy, episodes in which intense emotions (brought on by rough play, tasty treats, or other stimuli) cause them to lose all muscle tone and collapse in a heap, unable to move but wide-eyed and alert. This condition mimics the physical aspect of sleep, without the mental aspect. By recording the electrical chatter of neurons in the dogs' brains, Jerry Siegel and his colleagues at the University of California, Los Angeles, previously found that in cataplexy, certain neurons in a brain region called the hypothalamus reduce their activity. These neurons release one of two neurotransmitters, noradrenaline or serotonin, suggesting that these neurotransmitters are important for maintaining the physical side of wakefulness. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Sleep
Link ID: 5548 - Posted: 06.24.2010

Researchers at Edinburgh University have claimed they can predict who is susceptible to obesity. They said their work explains how some people can consume high-fat food without putting on weight. They have been working with mice which, like humans, are prone to becoming fat when given a rich diet. The study discovered that some of the mice have a natural ability to deal with a "junk food" diet without suffering ill-effects. The research was funded by the Wellcome Trust and led by endocrinologist Dr Nik Morton. It involved feeding mice a diet of "mouse hamburgers" to simulate the food consumed by many humans. Dr Morton said: "Until now we knew little about why some of us can follow this lifestyle and stay lean and healthy, whereas others pile on the pounds. "This research has shown one of the possible reasons why individuals have such differing responses to the intake of too much fatty food: an enzyme we express in our fat stores and liver." Some of the mice were found to have a higher level of the enzyme (11-HSD-1) which made them more prone to becoming obese.

Keyword: Obesity
Link ID: 5547 - Posted: 05.28.2004

By ELIZABETH OLSON - Four decades after the surgeon general's first report on smoking and health linked cigarette use to lung cancer, larynx cancer and bronchitis, the latest annual report has further expanded the list of smoking-related diseases. The new report, issued Thursday by Surgeon General Richard H. Carmona, concludes that in addition to the many other diseases listed in the intervening years, smoking can cause cancers of the cervix, kidney, pancreas and stomach, as well as abdominal aortic aneurysms, acute myeloid leukemia, cataracts, pneumonia and gum disease. The report, Dr. Carmona said at a news briefing, "documents that smoking causes disease in nearly every organ in the body at every stage of life." Among the other disorders listed since the first report, in 1964, are cancers of the esophagus, throat and bladder; chronic lung disease; and chronic heart and cardiovascular diseases. Copyright 2004 The New York Times Company

Keyword: Drug Abuse
Link ID: 5546 - Posted: 05.28.2004

by John Tidwell So there you are, gazing proudly at all those cute, colorful reef fish in your saltwater aquarium, serene in the knowledge that you know precisely which fish is what, right down to the species’ names and the individuals’ genders. But wait—weren't there supposed to be two red female stoplight parrotfish? How the heck did a green male get in there? Better get used to it—he used to be a she. In the wild, gender ambiguity is natural and practically anything goes, as long as it works. For the past couple billion years, plant and animal species have tried all sorts of ways to solve the problem of how to survive and make as many babies as possible. In that time, they evolved a mind-reeling array of solutions. From protozoa to pill bugs to porgies, changing from one sex to another is not just biological ingenuity, it’s a way of life. It’s also shocking proof that gender is a much more versatile, flexible tool in Mother Nature’s kit than anyone had previously realized—and is kinkier than you ever imagined. Your very green, very male stoplight parrotfish eyes you knowingly through the glass, as if to say “You ain’t seen nothin’ yet!” What in the name of Charles Darwin is going on here? Copyright 2004 Friends of the National Zoo.

Keyword: Sexual Behavior; Evolution
Link ID: 5545 - Posted: 06.24.2010

Is being fearful or shy actually bad for your health? Two researchers are studying the effect of these states of mind on our stress levels, and, in turn, our health. Sonia Cavigelli, a biological psychologist at the University of Chicago, studied 14 pairs of brother rats, with each pair consisting of one brave rat and one fearful rat (or, one neophilic and one neophobic), and exposed them to new environments with unfamiliar objects. The brave rats explored quickly and willingly, but the fearful rats froze up and did not explore much. She told Discover Magazine that it's bad news to be a scaredy rat. "What we found was that the fearful animals are dying at a rate approximately 60 percent faster than the non-fearful animals," says Cavigelli. "The difference in age between the two kinds of animals, if you compare it to humans, was approximately a difference of about 10 years." © ScienCentral, 2000-2004.

Keyword: Stress
Link ID: 5544 - Posted: 06.24.2010

Researchers have produced what they say is the best evidence to date that food additives aggravate hyperactive behavior in children. To many parents that's an article of faith. But numerous studies over the past 30 years have failed to provide conclusive evidence. John Warner, a pediatric allergist at the University of Southampton, U.K., and colleagues studied what they say is the largest group of subjects ever assembled from the general population for such a study: 277 3-year-olds on the Isle of Wight, about half of whom were diagnosed with attention deficit hyperactivity disorder (ADHD). In the monthlong trial, each child spent a week drinking juice spiked with food colorings and sodium benzoate, a common preservative. After a week of drying out, they spent another week drinking identical-tasting juice with no additives. Parents were blind to the study design. The additives in the juice were "no more than what you would expect in a reasonable child's diet," says Warner. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: ADHD
Link ID: 5543 - Posted: 06.24.2010

ALS is an incurable paralysing muscle disorder affecting five in every one hundred thousand people. The disease mainly strikes healthy people in the most active period of their life, without any warning or family history. Researchers from VIB (the Flanders Interuniversity Institute for Biotechnology), lead by Prof. Peter Carmeliet (K.U.Leuven) already indicated the importance of the VEGF protein in this illness, on the basis of genetic studies. In cooperation with Oxford BioMedica, an Oxford-based biotech company, a new study of the VIB researchers indicates that gene therapy with VEGF appears to be one of the most promising therapies. By administering the gene that produces VEGF in the nerve trajectory of ALS mice, the researchers were able to slow down the development of the illness and increase their life expectancy by 30% - the largest therapeutic effect ever achieved for ALS. ALS can affect anyone. Chinese leader Mao Tse Tung, Russian composer Dimitri Sjostakowitz, legendary Yankee baseball player Lou Gehrig and astrophysicist Stephen Hawkins were all affected by ALS. A large number of Italian top football players, pilots and soldiers in the Gulf War were also affected by this fatal disease. Around half of them die within three years, some even within a year, mostly in full possession of their faculties as a result of asphyxiation.

Keyword: ALS-Lou Gehrig's Disease ; Trophic Factors
Link ID: 5542 - Posted: 05.28.2004

(SACRAMENTO, Calif.) -- Despite the highly publicized closing of the Women's Health Initiative study, the scientific community should not rule out that women may benefit from hormone therapy after menopause, say researchers at UC Davis, Duke and Harvard Universities. Their review of the scientific literature on the biology of estrogens and progestins appears in the May 28 issue of the journal Science. "It was right to close the Women's Health Initiative trial," said Judith L. Turgeon, professor of internal medicine at UC Davis School of Medicine and senior author of the Science article. "But we should not generalize the results of this trial and overlook the real potential that other forms of hormone therapy may offer to postmenopausal women." The Women's Health Initiative trials used the steroid formulation most frequently prescribed in the United States at the time, given to women in pill form on a daily basis. New information gleaned from basic research in the biology of ovarian hormones, however, indicates that not all estrogens and progestins are alike, nor do they behave identically in different tissues in the body. "As our understanding of the biology of these hormones grows, the more we realize how important certain factors are -- such as formulation, dosage, whether they're given by a pill or a patch, and characteristics of women being treated," said co-author Phyllis M. Wise, dean of the division of biological sciences and distinguished professor of neurobiology, physiology and behavior at UC Davis. "More targeted therapies may yield important health benefits."

Keyword: Hormones & Behavior
Link ID: 5541 - Posted: 05.28.2004

David Perlman, Chronicle Science Editor An international team of scientists, seeking to track the course of human evolution and the ancient roots of genetic diseases, has completed the first highly accurate map of the genes in a single chimpanzee chromosome and compared them gene-by-gene with their human counterparts. The result, the scientists say, reveals surprising differences between the species, even though they are the closest of relatives in the primate family. The international team completed the first sequence of the genes in chimp chromosome pair No. 22, one of 24 chromosome pairs in the chimpanzee. That pair is the counterpart of chromosome 21 in the human array of 23 chromosome pairs. The sequencing feat was accomplished by a consortium of scientists working at genetics centers in five nations headed by Yoshiyuki Sakaki and Asao Fujiyama of Japan's Genomics Sciences Center in Yokohama. ©2004 San Francisco Chronicle

Keyword: Evolution; Genes & Behavior
Link ID: 5540 - Posted: 06.24.2010

— Experiments by Howard Hughes Medical Institute (HHMI) researchers have revealed it might be possible for randomness in gene expression to lead to differences in cells — or people, for that matter — that are genetically identical. The researchers, HHMI investigator Erin K. O'Shea and colleague Jonathan M. Raser, both at the University of California, San Francisco, published their findings May 27, 2004, in Science Express, the online edition of the journal Science. According to O'Shea, the original notion that random noise in gene expression — the processes by which proteins are synthesized from the information contained in DNA — arose from a paradox. “While processes such as gene expression involved in the development of organisms proceed in a very orderly fashion, paradoxically, they depend on chemical reactions that are inherently probabilistic, like flipping a coin,” said O'Shea. “And since these processes involve small numbers of molecules, they should be significantly affected by chance, just as flipping a coin a few times will be more heavily affected than flipping it many times.” ©2004 Howard Hughes Medical Institute

Keyword: Genes & Behavior
Link ID: 5539 - Posted: 06.24.2010

Scientists may have developed a gene therapy treatment for the most common form of motor neurone disease (MND). In lab tests on mice the therapy slowed onset and progression of Amyotrophic Lateral Sclerosis (ALS). It also extended life expectancy by 30%. Writing in the journal Nature, the research team at biopharmaceutical firm Oxford BioMedica stressed the work is at an early stage. MND affects about 5,000 people in the UK and there are 1,000 new cases a year. The disease is caused by the death of cells - called motor neurones - that control movement in the brain and spinal cord. There is currently no known cure. ALS is a form of the disease which affects adults, leading to paralysis and death within five years for most patients. The new treatment - called MoNuDin - essentially consists of a gene which triggers production of a chemical called a vascular endothelial growth factor (VEGF). The gene is injected into the muscles, but stimulates VEGF production in the nerve cells of the spine. (C)BBC

Keyword: ALS-Lou Gehrig's Disease
Link ID: 5538 - Posted: 05.27.2004

Measuring brain cell activity in dogs with a genetic form of narcolepsy, neurobiologists Jerome Siegel and his colleagues have presented evidence that wakefulness is maintained by the activity of neurons triggered by the neurotransmitter histamine. The discovery will be appreciated by anyone in whom antihistamines in allergy or over-the-counter sleep drugs cause drowsiness. The findings offer new insights both into normal sleep and narcolepsy. To "dissect" the neurological components of sleep, the scientists studied the phenomenon of cataplexy -- the abrupt loss of muscle tone while maintaining a state of complete wakefulness. The majority of narcoleptics suffer from this malady, in which a strong emotion, even a funny joke, can cause them to drop into a state of paralyzed awareness ranging from a few seconds to half an hour. Similarly, in narcoleptic dogs, emotional excitement, play, or even receiving a favorite food can trigger cataplexy. The researchers have been using cataplexy as a unique natural "experiment" to distinguish the neural basis of loss of consciousness from that of skeletal muscle paralysis during sleep. In their studies, they have concentrated on the role of three kinds of neurons in the brain's hypothalamus -- the central controlling region for sleep and wakefulness.

Keyword: Sleep
Link ID: 5537 - Posted: 05.27.2004

They were meant to show that gender was determined by nurture, not nature - one identical twin raised as a boy and the other brought up as a girl after a botched circumcision. But two years ago Brian Reimer killed himself, and last week David - formerly Brenda - took his life too. Oliver Burkeman and Gary Younge unravel the tragic story of Dr Money's sex experiment Until a few years ago, the name David Reimer meant little to those outside his immediate circle, and by the time he killed himself last Tuesday in unknown circumstances in his hometown of Winnipeg, it was already slipping back towards obscurity - a name belonging to nobody more remarkable than a local odd-job man, a 38-year-old former slaughterhouse worker who was separated from his wife, and enjoyed shopping at flea markets and tinkering with his car. In fact, to anyone taking an interest in the development of psychology in the 1970s and 1980s, Reimer's life story would have long been infamous, but also pseudonymous. Going by the name "John", and subsequently "Joan", David Reimer had been an unwitting guinea-pig - along with his identical twin brother Brian - in a medical experiment at first celebrated, then notorious. Masterminded by a prominent Baltimore physician, John Money, it was an attempt to settle, once and for all, the fraught nature-versus-nurture debate: to prove that gender was so fluid that by a mere change in childrearing practice, plus a little surgery, a boy could be turned into a girl, while his twin developed as a male. Guardian Unlimited © Guardian Newspapers Limited 2004

Keyword: Sexual Behavior
Link ID: 5536 - Posted: 06.24.2010

Scientists have discovered that the brain's centre of reasoning is among the last areas to mature. The finding, by a team at the US National Institute of Mental Health, may help to explain why teenagers often seem to be so unreasonable. Researchers used imaging techniques to show "higher order" brain areas do not develop fully until young adulthood. The research is published in the journal Proceedings of the National Academy of Sciences. The decade-long study used magnetic resonance imaging to follow the development of the brains of 13 health children every two years as they grew up. The aim was to get a better picture of how the brain develops so that it would be easily to pin down abnormalities that occur in conditions such as schizophrenia. The researchers found that grey matter - the working tissue of the brain's cortex - diminishes in a back-to-front wave over time. They believe this is a key part of the maturation process, whereby unused and unneeded connections between brain cells are gradually destroyed. They found the first areas to mature were those with the most basic functions, such as processing the senses and movement. Next came areas, such as the parietal lobes, involved in spatial orientation and language. (C)BBC

Keyword: Development of the Brain; Hormones & Behavior
Link ID: 5535 - Posted: 05.27.2004

Humans and their closest relatives, chimpanzees, may be more different than geneticists have realised. Previously, scientists have estimated that humans and chimps differ in about 1.5 per cent of the DNA letters that spell out their genomes. However, these estimates have been based on studies of only small subsets of the two genomes, because the chimp genome has not been sequenced precisely enough to allow a large-scale, base-by-base comparison. That has now changed, thanks to the International Chimpanzee Chromosome 22 consortium, a team of researchers based in Asia and Europe that has sequenced a single chimpanzee chromosome in unprecedented detail. The group then compared this sequence against its human counterpart, chromosome 21. They found that the two differ at only 1.44 per cent of the DNA bases that the two chromosomes have in common - a minuscule difference that confirms earlier estimates. © Copyright Reed Business Information Ltd

Keyword: Genes & Behavior; Evolution
Link ID: 5534 - Posted: 06.24.2010

Tampa, FL -- Werewolves notwithstanding, the full moon does not influence the frequency of epileptic seizures, reports a University of South Florida study. "Contrary to the myth, epileptic seizures are not more common during a full moon," said Selim Benbadis, MD, associate professor of neurology and neurosurgery at the USF College of Medicine. "In fact, we found the number of epileptic seizures was lowest during the full moon and highest in the moon's last quarter." The study, to be published in an upcoming issue of the journal Epilepsy & Behavior, is posted in the journal's online version. Dr. Benbadis said he decided to investigate the possible relationship between phases of the moon and the frequency of seizures after repeatedly hearing patients claim that their seizures were triggered or worsened by the full moon. "Even some health care professionals believe this, but it's never been scientifically tested," he said.

Keyword: Epilepsy; Biological Rhythms
Link ID: 5533 - Posted: 05.27.2004

How the brain stores those meaningful memories Smells trigger memories but can memories trigger smell, and what does this imply for the way memories are stored? A UCL study of the smell gateway in the brain has found that the memory of an event is scattered across sensory parts of the brain, suggesting that advertising aimed at triggering memories of golden beaches and soft sand could well enhance your desire to book a seaside holiday. By reversing the premise used in Marcel Proust's Remembrance of Things Past, UCL researchers established that the memory of an event is spread across different areas of the brain such as the hippocampus and the olfactory cortex - the smell gateway of the brain. In Proust's story, protagonist Charles Swann is transported back to his childhood when the smell of a biscuit dipped in tea triggers memories from his past.

Keyword: Learning & Memory; Chemical Senses (Smell & Taste)
Link ID: 5532 - Posted: 05.27.2004

A study in the May 26 issue of The Journal of the American Medical Association (JAMA) suggests that prenatal cocaine exposure was not associated with lower full scale IQ scores, or verbal or performance IQ scores at age 4 years. However, the study also found that prenatal cocaine exposure was associated with specific cognitive impairments and a lower likelihood of an above average IQ, but that home environments could make a difference for better outcomes for some children. "Cocaine readily crosses the placental and fetal brain barriers and has a direct effect on the developing fetal brain …" the authors provide as background information in the article. The authors add that "a number of methodologically sound studies have found a relationship between fetal cocaine exposure and negative child developmental outcomes in the first years of life, although others have not." In this study, Lynn T. Singer, Ph.D., from Case Western Reserve University, Cleveland, and colleagues assessed the effects of prenatal cocaine exposure and the quality of the caregiving environment on cognitive outcomes. The participants included 376 children (190 cocaine-exposed and 186 non-exposed) from a high-risk population who were enrolled in a longitudinal study from birth (September 1994 – June 1996). They were screened for drug exposure as infants, assessed at 6, 12 and 24 months of age and then tested at 4 years old for cognitive developments.

Keyword: Drug Abuse; Development of the Brain
Link ID: 5531 - Posted: 06.24.2010

A team of U.S. and Irish researchers has come one step closer to understanding why a high proportion of the population is genetically at risk for neural tube defects, according to a genetic study by researchers in Ireland and at two of the National Institutes of Health, the National Institute of Child Health and Human Development, and the National Human Genome Research Institute. Specifically, the researchers learned that having only one copy of a variant gene is enough to increase the chances of being born with a neural tube defect. Previously, researchers believed that two copies of the gene were needed to increase someone's risk of being born with a neural tube defect. The finding underscores the need for all women of childbearing age to follow the current recommendation to take 400 micrograms of the vitamin folic acid each day. The study appears on the Web site of the British Medical Journal, at http://bmj.com and will appear in the print edition of the journal at a later date. Neural tube defects are a class of birth defects affecting the brain and spinal cord. In one type, spina bifida, a piece of the spinal cord protrudes from the spinal column, causing paralysis below the protrusion. In anencephaly, a fatal neural tube defect, the brain and skull are grossly underdeveloped.

Keyword: Development of the Brain
Link ID: 5530 - Posted: 05.26.2004