Researchers have discovered a key regulatory molecule whose overactivation by the abnormal protein produced in Huntington's disease (HD) causes the central pathologies of the disease. The abnormal HD protein activates the regulatory protein called p53, which in turn switches on a host of other genes. This abnormal gene activation damages the cells' power plants, called the mitochondria, and kills brain cells. The researchers also speculated that disturbances in p53 may also play a role in some forms of Parkinson's disease and amyotrophic lateral sclerosis, or Lou Gehrig's disease. Ironically, p53 is the same regulatory protein that is inactivated in a large fraction of cancers. This inactivation allows abnormal cancer cells to escape the cell's protective "suicide program" that would normally kill them. The researchers theorize that the lower incidence of cancer in HD patients could be caused by the protective effect of overactive p53. In the July 7, 2005, issue of Neuron, Akira Sawa and colleagues at Johns Hopkins University School of Medicine reported experiments ranging from molecular studies in cultured brain cells to analysis of the brains of human HD patients that demonstrated the central role of p53 in the pathologies of HD.

Keyword: Huntingtons
Link ID: 7602 - Posted: 07.07.2005

Michael Hopkin Women are most likely to cheat on their long-term partner when they are at their most fertile, and they tend to choose genetically superior men for their fling. That's the claim of a study by Czech researchers, which found that the smell of a socially dominant male is most exciting to women in stable relationships, especially on days when they are ovulating. Jan Havlícek, of Charles University in Prague, and his colleagues asked 48 men to complete a questionnaire, rating statements such as "I am the life of the party", in order to score the volunteers' social dominance. The researchers also asked them to wear cotton pads under their arms to collect sweat. A group of 65 women then smelled the pads and rated the sexiness and masculinity of the scent. Women in the middle week of their menstrual cycle, the point at which fertility is at its peak, tended to prefer the smell of the men who scored highest on the dominance quiz. This preference was not shown by women at other points in their cycle. What's more, the effect was only significant for women in long-term relationships, the researchers report in the journal Biology Letters1. This shows that both menstrual phase and relationship status can have an effect on which men women tend to prefer, says Havlícek. ©2005 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 7601 - Posted: 06.24.2010

For newborn mammals, including humans, identifying Mom by her odor can be critical to maternal bonding and survival. However, researchers have not understood how this odor identification develops. Now, Kevin Franks and Jeffry Isaacson of the University of California, San Diego School of Medicine report in the July 7, 2005, issue of Neuron that this process develops in basically the same way that newborns' developing visual systems learn to recognize the world. That is, during a critical early period, the infant's olfactory circuitry wires itself as a result of experiencing Mom's odor. In their initial experiments with rat brains, the researchers identified two receptors, called AMPA receptors and NMDA receptors, as the key components of the olfactory circuitry that undergoes such early olfactory adaptation. Such receptors are proteins embedded in the "receiving stations" of neurons and are activated by chemical signals called neurotransmitters--in this case, the neurotransmitter glutamate. Alterations in the relative numbers of such receptors "tune" neurons to be more or less likely to be triggered by neurotransmitters. Thus, such changes in networks of neurons can lay down the preferred neural pathways that constitute learning. The researchers found in studies of rat brain tissue that as newborn rats aged, the fraction of NMDA receptors tended to go down in a brain olfactory processing region called the lateral olfactory tract. This reduction tended to activate connections among neurons in the region.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 7600 - Posted: 07.07.2005

No single androgen (sex hormone) level was found to be predictive of low sexual function in women, according to a study in the July 6 issue of JAMA. Sexual dysfunction, primarily low libido, is common among women, with prevalences of 8 percent to 50 percent, according to background information in the article. Although multiple psychosocial and health factors contribute to low sexual desire and arousal, it has been proposed that androgen levels are significant independent determinants of sexual behavior in women. It is widely believed that a low serum free testosterone level is the diagnostic marker for the cluster of symptoms described as characterizing "female androgen insufficiency" based on therapeutic trials, and expert opinion. However, evidence that a low serum testosterone level distinguishes women with low sexual function from others, is lacking. Susan R. Davis, M.D., Ph.D., of Monash Medical School, Alfred Hospital, Victoria, Australia, and colleagues conducted a study to determine if low self-reported sexual function is associated with low serum androgen levels. The study included 1,423 women aged 18 to 75 years who were randomly recruited from April 2002 to August 2003. Women were excluded from the analysis if they were younger than 45 years and using oral contraception. Women were surveyed with the Profile of Female Sexual Function (PFSF) and serum levels of total and free testosterone, androstenedione (an androgenic steroid), and dehydroepiandrosterone sulfate (DHEAS, a natural steroid hormone) were measured. The researchers write: "We found no evidence of associations between low scores for any of the sexual domains evaluated and low serum total and free testosterone levels. In contrast, we observed significant associations between low sexual desire, arousal, and responsiveness in younger women [aged 18 to 44 years] and low responsiveness in older women [aged 45 years or older] and low serum DHEAS level relative to age."

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 7599 - Posted: 07.06.2005

When encouraged to use memorization strategies commonly employed by healthy individuals, people with schizophrenia can be helped to remember information just as well as their healthy counterparts, a process that in itself seems to spur a normalization of memory-related activities in the brains of people with schizophrenia, suggests new research from Washington University in St. Louis. For decades, schizophrenia treatment has relied on powerful drugs to control the disease's most debilitating symptoms -- hallucinations, delusions and paranoia – often ignoring seemingly less ominous problems associated with learning, memory, attention and other cognitive functions that are so basic to everyday life. Now, as part of a new wave of research aimed at helping people with schizophrenia lead fuller, more normal lives, a study at Washington University in St. Louis has demonstrated that people with schizophrenia can be helped to remember things just as well as healthy subjects as long as they are given proper cues and memory aids. The study suggests a new way of understanding the cognitive problems that underlie schizophrenia, and offers hope that schizophrenia's suffering can be alleviated through the development of more effective cognitive rehabilitation programs.

Keyword: Schizophrenia
Link ID: 7598 - Posted: 06.24.2010

Vitamin E supplements do not protect healthy women against heart attacks and stroke, according to new results from the Women’s Health Study, a long-term clinical trial of the effect of vitamin E and aspirin on both the prevention of cardiovascular disease and of cancer. The vitamin E results of the Women’s Health Study are published in the July 6 issue of the Journal of the American Medical Association. In addition to the cardiovascular disease findings, the study authors report that there was no effect of vitamin E on total cancer or on the most common cancers in women — breast, lung, and colon cancers. The Women’s Health Study was funded by the National Heart, Lung, and Blood Institute (NHLBI) and the National Cancer Institute of the National Institutes of Health. “This landmark trial has given women and their physicians important health information. We can now say that despite their initial promise, vitamin E supplements do not prevent heart attack and stroke. Instead, women should focus on well proven means of heart disease prevention, including leading a healthy lifestyle and controlling risk factors such as high blood pressure and high cholesterol,” said NHLBI Director Elizabeth G. Nabel, M.D. The Women’s Health Study was conducted between 1992 and 2004. The participants were 39,876 healthy women age 45 years and older who were randomly assigned to receive 600 IU of Vitamin E or placebo and low-dose aspirin or placebo on alternate days. The participants were followed for an average of 10.1 years. The aspirin results published last March found no benefit of aspirin (100 mg every other day) in preventing first heart attacks or death from cardiovascular causes in women but did find a reduced risk of stroke overall, as well as reduced risk of both stroke and heart attack in women aged 65 and older.

Keyword: Stroke
Link ID: 7597 - Posted: 06.24.2010

Roxanne Khamsi People itching for a solution to seasonal allergies could get help from self-hypnosis, a team of Swiss researchers suggests. The study finds that simply focusing one's thoughts on allergen-free environments can reduce symptoms of hay fever by one-third. Although the arrival of spring brings better weather, it also triggers the release of plant pollens that cause allergies. Hay fever affects about 10-15% of adults in industrialized nations. To treat this, people turn to medications such as antihistamines, decongestants and sometimes steroids. But these can cause side-effects such as drowsiness, a dry mouth and raised blood pressure. Allergy sufferers have sought alternatives approaches, including psychotherapy-related methods, to ease their itchy eyes and runny noses. Wolf Langewitz of the University Hospital Basel, Switzerland, and his colleagues sought to find out how well self-hypnosis works. The team recruited 79 patients with moderate to severe allergic reactions to grass or tree pollen, who then received training on self-hypnosis. To achieve successful results using self-hypnosis, says Langewitz, one must first enter a trance-like state and then focus the mind on a particular theme. The whole process, he adds, can take as little as five minutes. ©2005 Nature Publishing Group

Keyword: Neuroimmunology
Link ID: 7596 - Posted: 06.24.2010

There is growing evidence that a common childhood throat infection increases the risk of neurological disorders such as Tourette's syndrome. Scientists found children with such disorders were twice as likely to have had recent streptococcal infections than their healthy peers. Researchers at Seattle's Center for Health Studies suggest the body's response to the infection may be key. But they tell the journal Pediatrics, that it is just one potential trigger. OCD is more commonly associated with adults, but the researchers say it affects around 1 to 2% of school-age children - and transient tics can affect 10 to 25% of primary school age children. Tourette's - a neurological disorder characterized by tics, involuntary vocalization, and, in some cases, the compulsive utterance of obscenities - affects around one in every 100 children to some degree. Scientists had suspected there may be a link between the streptococcal infection and neurological disorders. It has been suggested that the body's natural response to infection, where particular antibodies are produced and directed to parts of the brain, might be linked in some way to these disorders. However, it is not clear why most of the millions of children who have bacterial throat infections each year do not develop such disorders. (C)BBC

Keyword: Tourettes; OCD - Obsessive Compulsive Disorder
Link ID: 7595 - Posted: 07.05.2005

By Rick Weiss, Washington Post Staff Writer A mysterious biological mechanism that subtly changes the way people's genes behave may account for many of the surprising differences between identical twins, researchers announced yesterday. Geneticists said the new work, by an international team of scientists who studied the DNA of more than 40 pairs of twins, strengthens the case that a fledgling research field called epigenetics holds the long-sought answer to one of biology's toughest questions: How do environmental influences, such as exposure to pollutants, consumption of certain foods or perhaps even powerful emotional experiences, produce lasting and potentially life-altering changes in a person's DNA? Beyond its potential importance for understanding differences in identical twins, epigenetics could explain many of the twists of fate that affect ordinary people -- why one person may be struck by cancer, for example, while another is spared, even though neither's DNA harbors a cancer-causing mutation. "This is how the environment talks to the genome," said Rudolf Jaenisch, a geneticist at the Whitehead Institute for Biomedical Research in Cambridge, Mass., who was not part of the project. "This paper says lifestyle, or environmental influences or whatever you want to call them, have a real influence on your DNA." © 2005 The Washington Post Company

Keyword: Genes & Behavior
Link ID: 7594 - Posted: 06.24.2010

By BENEDICT CAREY Some people are attracted to women; some are attracted to men. And some, if Sigmund Freud, Dr. Alfred Kinsey and millions of self-described bisexuals are to be believed, are drawn to both sexes. But a new study casts doubt on whether true bisexuality exists, at least in men. The study, by a team of psychologists in Chicago and Toronto, lends support to those who have long been skeptical that bisexuality is a distinct and stable sexual orientation. People who claim bisexuality, according to these critics, are usually homosexual, but are ambivalent about their homosexuality or simply closeted. "You're either gay, straight or lying," as some gay men have put it. In the new study, a team of psychologists directly measured genital arousal patterns in response to images of men and women. The psychologists found that men who identified themselves as bisexual were in fact exclusively aroused by either one sex or the other, usually by other men. The study is the largest of several small reports suggesting that the estimated 1.7 percent of men who identify themselves as bisexual show physical attraction patterns that differ substantially from their professed desires. Copyright 2005 The New York Times Company

Keyword: Sexual Behavior
Link ID: 7593 - Posted: 07.05.2005

By Krishna Ramanujan ITHACA, N.Y. -- Cornell University researchers have learned how a common fish found along the West Coast can hum and hear outside sounds at the same time. The study marks the first time that scientists have found a direct line of communication between the part of a vertebrate's brain that controls the vocal muscle system and the part of the ear that hears sound. The researchers believe that understanding the auditory system of the plainfin midshipman fish (Porichthys notatus ) -- a 6- to 10-inch fish found along the coastline from Alaska to California -- will offer insights into how other vertebrates -- including humans -- hear. The general pattern of connections between neurons in the auditory system is the same in all vertebrates, including mammals. While humans hear with the cochlea of the inner ear, the midshipman uses the sacculus, a part of the ear that in humans detects acceleration or linear movement. Because the study indicates a relationship between the ear and the auditory and vocalization systems of the brain, it could help scientists understand some of the mechanisms that contribute to deafness.

Keyword: Hearing; Sexual Behavior
Link ID: 7592 - Posted: 07.05.2005

At first glance identical twins seem, well, identical. In fact many of these sibling pairs show minor physical variations and differences in characteristics such as susceptibility to disease. Just what causes these dissimilarities is unclear. But a new report suggests that epigenetic factors--that is, differences in how the genome is expressed--could responsible. Mario F. Fraga of the Spanish National Cancer Center and his colleagues studied 160 monozygous twins ranging from three to 74 years of age. They analyzed two epigenetic traits, DNA methylation and histone acetylation, along the entire genome and compared the results for each set of twins. They determined that early in life, twins were indistinguishable in the manner in which their genes were expressed. Among older sets of twins, however, significant differences in the gene-expression portraits were apparent for 35 percent of the study group. (The image above shows methylation patterns for three-year-old twins (left) and 50-year-old twins (right), with the differences highlighted in red.) In addition, twins who had spent the most time apart and had more divergent medical histories exhibited the greatest epigenetic differences. Environmental factors, including smoking habits, physical activity levels and diet, can influence epigenetic patterns and may help explain how the same genotype can be translated in different ways, the scientists say. They suggest that future studies should investigate specific mechanisms that cause this so-called epigenetic drift in identical twins. A report describing the work is published online this week by the Proceedings of the National Academy of Sciences. --Sarah Graham © 1996-2005 Scientific American, Inc.

Keyword: Genes & Behavior
Link ID: 7591 - Posted: 06.24.2010

CHICAGO — Individuals with problem gambling behavior have personality profiles similar to the profiles of those with alcohol, marijuana and nicotine-associated addictive disorders, according to an article in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals. It has been difficult to identify personality traits associated with problem gambling because most previous studies have drawn subjects from those seeking treatment for a gambling disorder, who are unlikely to be representative of the majority of individuals in the community with gambling problems, according to background information in the article. Previous studies have also shown problem gambling associated with alcohol dependence and suggested an association with drug and nicotine dependence as well. Wendy S. Slutske, Ph.D., of the University of Missouri-Columbia, and colleagues compared personality assessments obtained in 1991-1992 for 939 young adults (475 men and 464 women) from Dunedin, New Zealand, who were 18 years old, with diagnoses of problem gambling and alcohol, cannabis [marijuana] and nicotine dependence in the previous year based on structured interviews conducted when the individuals were 21 years old in 1993-1994. The researchers conducted two analyses of the data. In the first, the researchers examined the associations between problem gambling and each of three substance abuse disorders (alcohol, cannabis and nicotine). In the second, the researchers examined the independent association of 10 basic aspects of personality variation with problem gambling and each of the three substance addictive disorders.

Keyword: Drug Abuse
Link ID: 7590 - Posted: 06.24.2010

A new classification tool may allow healthcare professionals treating children with autism and autism-related disorders to more systematically sort out the combination of traits in the condition, and to better predict how children may improve over time. If the model holds up to further study, it may also allow researchers to gauge the effectiveness of different autism treatments. Developmental pediatrician James Coplan, M.D., reports on a study of 91 children he saw between 1997 and 2002 at the Regional Autism Center of The Children's Hospital of Philadelphia. Most patients were pre-schoolers or of elementary school age, and predominantly boys. The study appears in the July 2005 issue of Pediatrics. The children in the study had autistic spectrum disorders (ASD), a group of neurodevelopmental disorders of impaired social communication. Those disorders include classic autism, pervasive developmental disorder and Asperger's syndrome. Dr. Coplan studied the relationship among three variables: the severity of the disorder (called atypicality), general intelligence (measured as IQ or developmental quotient) and time. "These disorders are dynamic and change over time," says Dr. Coplan. "Although they are traditionally classified into mutually exclusive diagnostic boxes, they tend to blend into each other, and this model provides a way to look continuously at ASD, as the symptoms occur and develop along the autistic spectrum, and as the symptoms change over time."

Keyword: Autism
Link ID: 7589 - Posted: 07.05.2005

Women are bigger wimps than men when it comes to pain, research suggests, contrary to the popular notion that the reverse is true. Not only do they feel pain more easily, women are less able to cope with it, believe scientists at Bath University. Women focus on the emotional aspects of their pain, which makes it worse, while men tend to focus on the physicality. Their findings are based on a series of pain tests on 50 men and women using triggers such as ice cold water. Volunteers were asked to put their arm in a warm water bath for two minutes before plunging the same arm into a vat of icy water for a further two minutes or until they could stand the pain no longer. The women felt pain much sooner than the men and were able to endure it for far less time. Furthermore, when men were asked to think about the sensory aspects of the pain rather than the emotions related to it, the pain decreased. This strategy did nothing to help the women. Lead researcher Dr Ed Keogh, a psychologist at the Pain Management Unit at the university, said: "Our research has shown that whilst the sensory-focused strategies used by men helped increase their pain threshold and tolerance of pain, it was unlikely to have any benefit for women. "Women who concentrate on the emotional aspects of their pain may actually experience more pain as a result, possibly because the emotions associated with pain are negative." (C)BBC

Keyword: Pain & Touch; Sexual Behavior
Link ID: 7588 - Posted: 07.05.2005

Obese people can be fitted with a device that fools their brain into thinking they have eaten to help them lose weight. The technology, by Transneuronix, comprises a matchbox-sized pacemaker implanted into the abdomen, linked to electrodes in the stomach wall. Experts said it could be a new tool to fight the UK's obesity problem. However, it would not work miracles and the user must still eat a healthy diet and do exercise, they cautioned. The device works by triggering the nerves in the stomach that are involved in digestion. These tell the brain that the stomach is full so the individual feels as though they have already eaten even though they have not. Similar devices are available on the market and some have already been fitted in private clinics in the UK. A spokesman from Transneuronix said a physician at Aberdeen Royal Infirmary would be trained in the technology at the end of the month. However, Transneuronix tells potential patients: "Surgery is not a cure for the chronic disease of morbid obesity, but it can be an effective tool to fight the disease. Having surgery does not excuse you from a personal responsibility for your health. If you snack between meals, do not exercise regularly, and do not participate in ongoing post-surgical therapeutic support programs, you can regain weight." (C)BBC

Keyword: Obesity
Link ID: 7587 - Posted: 07.05.2005

A multi-site study sponsored by the National Institute of Mental Health (NIMH) finds children with autism characterized by tantrums, aggression, and/or self-injury respond favorably to the antipsychotic medication risperidone for up to six months. Published in the July edition of the American Journal of Psychiatry, the study found the medication not only decreased aggression but also reduced repetitive behaviors and increased social interaction – all with limited side effects. The two-part study also found discontinuation after six months prompted rapid return of disruptive and aggressive behavior in most cases. Atypical antipsychotic medications such as risperidone are of interest to doctors who treat children with autism because studies show the newer medications benefit adults with schizophrenia with fewer neurological side effects than older options. "A variety of treatments, including medication, are used to manage aggressive behaviors in autistic children, but controlled medication trials are limited," said Dr. James McCracken, lead author and site investigator at the Semel Institute for Neuroscience and Human Behavior at UCLA. "Our findings support adding risperidone to the small arsenal of intermediate-term medication options for the tens of thousands of children with autism who display aggressive and destructive behaviors.

Keyword: Autism; Schizophrenia
Link ID: 7586 - Posted: 06.24.2010

A drug that relieves the symptoms of Parkinson’s disease – but was controversially withdrawn over toxicity fears – has now been shown to stimulate growth of the nerve fibres damaged by the disease. When delivered directly to the brain, glial cell-line derived neurotrophic factor (GDNF) had been shown to stimulate regrowth of cells in animal models of Parkinson’s. But this is the first time regrowth has been seen in the human brain, says Steven Gill, a neurosurgeon at Frenchay Hospital, Bristol, UK. Gill was running a trial study where five patients with advanced Parkinson’s disease were fitted with a tiny catheter that delivered GDNF direct to the putamen, part of the basal ganglia in the centre of the brain. In the putamen of Parkinson’s patients the chemical messenger dopamine is lost. The symptoms of Parkinson’s - which include uncontrollable shaking and trembling - were reduced in all five patients. They showed dramatic improvements with respect to their motor skills, verbal memory, facial expressions and motivation. However, Amgen, the company that makes GDNF, withdrew the drug after fears over its toxicity and a second trial of 34 patients was halted. That was despite the fact that the toxicity trials involved testing far higher doses of GDNF on animal models, and that none of the human subjects had showed any ill-effects. © Copyright Reed Business Information Ltd.

Keyword: Parkinsons; Trophic Factors
Link ID: 7585 - Posted: 06.24.2010

Bruce Bower It's bad enough that some rhesus monkey mothers regularly kick, hit, bite, and otherwise brutalize their babies. But to make things worse, females exposed to such abuse as infants often grow up to become abusive parents themselves, perpetuating a primate cycle of family violence, a new study finds. Being abused as an infant outweighs any primarily genetic trait, such as an anxious temperament, in fostering abusive parenting by female monkeys, says primatologist Dario Maestripieri of the University of Chicago. His argument rests on two central observations. First, rhesus moms frequently mistreated their babies after having themselves been raised by abusive mothers, either biological or adoptive. Second, females born to abusive mothers uniformly became caring parents after having been raised by nonabusive adoptive mothers. "Rhesus monkeys are an excellent animal model of human child abuse," Maestripieri asserts. The ways in which these behaviors get transmitted across generations in monkeys and people "may be very similar," he adds. In people, roughly 30 percent of abused children become abusive parents. Maestripieri's team worked with a population of rhesus monkeys living at an outdoor research facility in Georgia. The population included some females who had been observed to abuse their offspring. The researchers transferred some newborns between mothers to create four groups of female infants: six infants born to physically abusive mothers and given as newborns to unrelated, nonabusive mothers; eight infants born to nonabusive mothers and adopted as newborns by abusive mothers; eight infants born to abusive mothers and raised by them; and nine infants born to nonabusive mothers and raised by them. Copyright ©2005 Science Service.

Keyword: Development of the Brain; Aggression
Link ID: 7584 - Posted: 06.24.2010

Naila Moreira Orca-whale and dolphin mothers and their newborns appear not to sleep for a month after the pups' birth, researchers report. Neither parent nor offspring shows any ill effects from the long waking stint, and the animals don't later compensate with extra sleep. No previously studied mammal stays awake for so long, says Jerry Siegel of the University of California, Los Angeles (UCLA), an investigator in the study. In the months following their wakeful period, baby whales and dolphins—and their mothers—ramped up slowly to sleep amounts typical of normal adults, Siegel and his colleagues report. The infants' sleep pattern contrasts with that of other mammals, which need extra sleep during infancy and gradually sleep less as they age. Oleg Lyamin, also of UCLA, started observing an orca mother and her baby just after it was born at SeaWorld, San Diego. Orcas usually snooze for 5 to 8 hours a night, closing both eyes and floating motionlessly. The SeaWorld orca mother and baby, Lyamin found, neither shut their eyes nor remained motionless. Instead, the animals were constantly active, with the infant surfacing for a breath every 30 seconds. The researchers made similar observations of another SeaWorld orca mom and baby. Copyright ©2005 Science Service.

Keyword: Sleep; Development of the Brain
Link ID: 7583 - Posted: 06.24.2010