By Jennifer Viegas, Discovery News — Genes and gender help determine an individual’s urge to scratch, suggests a new study on pruritus, otherwise known as itch. The study is the first to demonstrate sex differences in itch-induced scratching behavior in animals. The researchers studied mice, but the findings could apply to humans and other mammals. The conclusion? Females scratched themselves 23 percent more often than males did. "We haven’t investigated the underlying mechanisms of the sex difference yet, but they usually involve gonadal (reproductive gland) hormones, such as estrogen, progesterone and testosterone, either during development or in adulthood," said Jeffrey Mogil, one of the researchers. Mogil, a specialist in the genetics of pain at McGill University in Canada, and his colleagues induced itching in the mice by administering chloroquine, a malaria drug known to cause itchiness. The researchers also used histamines, compounds produced by mammalian tissues to dilate small blood vessels. Histamines are largely responsible for the itchiness associated with allergies, hence the relief provided by antihistamines. The team's findings have been accepted for publication in the journal Pain. © 2006 Discovery Communications Inc.

Keyword: Pain & Touch; Sexual Behavior
Link ID: 9014 - Posted: 06.24.2010

Jacqueline Ruttimann The commonest cause of blindness in the elderly has been treated with small pieces of genetic material that block genes. The result comes from the first clinical trial to assess the effectiveness of a therapy known as RNA interference (RNAi). The trial tested a drug called Bevasiranib on patients suffering from age-related macular degeneration (AMD), which erodes vision as blood vessels grow on the retina at the back of the eyes. The currently incurable condition affects about 1.65 million Americans. Bevasiranib was developed by Acuity Pharmaceuticals of Philadelphia. The company estimates that 11 million people worldwide will have AMD by 2013. The trial on 129 patients found that Bevasiranib reduced blood-vessel growth in the eyes and improved vision slightly. At the lowest doses, these effects lasted for several months; at higher doses the positive responses are still present, says Dale Pfost, Acuity's president. No adverse side effects were seen other than the anticipated swelling and inflammation at the site where the drug was injected into the eye. "It's a very encouraging result," says Pfost, who announced the preliminary findings at the meeting of the American Society of Gene Therapy in Baltimore on 1 June. ©2006 Nature Publishing Group

Keyword: Vision
Link ID: 9013 - Posted: 06.24.2010

SAN DIEGO, Calif.—A team of Johns Hopkins researchers developed a new radiotracer—a radioactive substance that can be traced in the body—to visualize and quantify the brain’s cannabinoid receptors by positron emission tomography (PET), opening a door to the development of new medications to treat drug dependence, obesity, depression, schizophrenia, Parkinson’s disease and Tourette syndrome. Discovery of the [11C]JHU75528 radioligand, a radioactive biochemical substance that is used to study the receptor systems of the brain, “opens an avenue for noninvasive study of central cannabinoid (CB1) receptors in the human and animal brain,” explained Andrew Horti, assistant professor of radiology at Johns Hopkins Medicine, Baltimore, Md. He explained that there is evidence that CB1 receptors play an essential role in many disorders including schizophrenia, depression and motor function disorders. “Quantitative imaging of the central CB1 using PET could provide a great opportunity for the development of cannabinergic medications and for studying the role of CB1 in these disorders,” added the co-author of “PET Imaging of Cerebral Cannabinoid CB1 Receptors with [11C]JHU75528.” Cannabinoid receptors are proteins on the surface of brain cells; they are most dense in brain regions involved with thinking and memory, attention and control of movement. The effects of tetrahydrocannabinol (THC), the primary psychoactive compound in marijuana, are due to its binding to specific cannabinoid receptors located on the surface of brain cells. “Blocking CB1 receptors presents the possibility of developing new, emerging medications for treatment of obesity and drug dependence including alcoholism, tobacco and marijuana smoking,” said Horti. © 2006 SNM

Keyword: Drug Abuse; Brain imaging
Link ID: 9012 - Posted: 06.24.2010

Peter Aldhous Huntington’s disease may be about to meet its match with the development of a therapy designed to knock out production of the defective protein that causes the condition. Huntington’s is an untreatable inherited disease in which repetitive sequences of DNA lead to the production of a faulty version of a protein called huntingtin, giving it multiple copies of the amino acid glutamine. As adults, its victims lose their cognitive abilities, suffer involuntary movements and, after a decade or more, die. This week at the American Society of Gene Therapy meeting in Baltimore, Maryland, researchers led by Beverly Davidson of the University of Iowa described their progress treating the disease with a technique called RNA interference, or RNAi. RNAi uses short sequences of RNA just over 20 bases long to trigger a natural “gene-silencing” mechanism, shutting down the production of specific proteins by targeting the RNA that carries the instructions for making them. Last year, Davidson raised the hopes of people carrying the Huntington’s gene when she used engineered viruses to treat mice with the mutated gene. The viruses produce “small interfering” RNA sequences designed to block the RNA carrying the message to make huntingtin. © Copyright Reed Business Information Ltd.

Keyword: Huntingtons
Link ID: 9011 - Posted: 06.24.2010

By ELISSA ELY, M.D. She was thinking of throwing herself in front of traffic. The day program had sent her over with her lunch in a bag, as if she were on a field trip instead of being there for a crisis evaluation. All morning she had been coming apart, and told us so in her own tongue. "I'm up and down, up and down, like the sun going in and out, in and out," she said, the lunch dangling out of her shoulder bag, unnoticed. "I'm losing my luster and my equilibrium." Equilibrium was something she had never known, actually. When she was a child, her mother had pushed her out of a speeding car. In adolescence, foster families had pushed her from one home to another. Medical illnesses had unbalanced her in adulthood. She tried to compensate with a deliberately sunny disposition. My office was full of drawings of flowers with pert pistil noses, houses with happy expressions in their window eyes, trees with beaming trunks. Then, for no particular reason — maybe a disagreement in the group home or a bad morning in the program — she would become possessed. Real and psychotic tragedies from the past and present became mixed up. Copyright 2006 The New York Times Company

Keyword: Schizophrenia
Link ID: 9010 - Posted: 06.24.2010

By BENEDICT CAREY The use of potent antipsychotic drugs to treat children and adolescents for problems like aggression and mood swings increased more than fivefold from 1993 to 2002, researchers reported yesterday. The researchers, who analyzed data from a national survey of doctors' office visits, found that antipsychotic medications were prescribed to 1,438 per 100,000 children and adolescents in 2002, up from 275 per 100,000 in the two-year period from 1993 to 1995. The findings augment earlier studies that have documented a sharp rise over the last decade in the prescription of psychiatric drugs for children, including antipsychotics, stimulants like Ritalin and antidepressants, whose sales have slipped only recently. But the new study is the most comprehensive to examine the increase in prescriptions for antipsychotics. The explosion in the use of drugs, some experts said, can be traced in part to the growing number of children and adolescents whose problems are given psychiatric labels once reserved for adults and to doctors' increasing comfort with a newer generation of drugs for psychosis. Shrinking access to long-term psychotherapy and hospital care may also play a role, the experts said. Copyright 2006 The New York Times Company

Keyword: Schizophrenia
Link ID: 9009 - Posted: 06.06.2006

A little-known mental disorder marked by episodes of unwarranted anger is more common than previously thought, a study funded by the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) has found. Depending upon how broadly it’s defined, intermittent explosive disorder (IED) affects as many as 7.3 percent of adults — 11.5-16 million Americans — in their lifetimes. The study is based on data from the National Comorbidity Survey Replication, a nationally representative, face-to-face household survey of 9,282 U.S. adults, conducted in 2001-2003. People with IED may attack others and their possessions, causing bodily injury and property damage. Typically beginning in the early teens, the disorder often precedes — and may predispose for — later depression, anxiety and substance abuse disorders. Nearly 82 percent of those with IED also had one of these other disorders, yet only 28.8 percent ever received treatment for their anger, report Ronald Kessler, Ph.D., Harvard Medical School, and colleagues. In the June, 2006 Archives of General Psychiatry, they suggest that treating anger early might prevent some of these co-occurring disorders from developing. To be diagnosed with IED, an individual must have had three episodes of impulsive aggressiveness “grossly out of proportion to any precipitating psychosocial stressor,” at any time in their life, according to the standard psychiatric diagnostic manual. The person must have “all of a sudden lost control and broke or smashed something worth more than a few dollars…hit or tried to hurt someone…or threatened to hit or hurt someone.”

Keyword: Emotions
Link ID: 9008 - Posted: 06.24.2010

A steadily increasing number of patients younger than age 20 received prescriptions for antipsychotic medications between 1993 and 2002, according to a report published in the June issue of Archives of General Psychiatry, one of the JAMA/Archives journals. Antipsychotics are medications used to treat mental disorders, such as schizophrenia and mania, that may involve loss of contact with reality. Several studies have indicated that prescriptions for these medications have been increasing among children and adolescents, raising concerns among professionals and the public. However, no national data have previously been available, according to background information in the article. Most prescriptions given to children and adolescents are for second-generation antipsychotics, which are not approved by the U.S. Food and Drug Administration for pediatric patients. Mark Olfson, M.D., M.P.H., College of Physicians and Surgeons, Columbia University, New York, and colleagues analyzed data from a national survey of office-based physicians conducted yearly by federal researchers. In addition to recording whether the child or adolescent patient received a prescription for antipsychotics, the physician or a staff member also logged the patient's age, sex and race or ethnicity; the length of the visit; the physician's specialty and whether the patient received psychotherapy.

Keyword: Schizophrenia
Link ID: 9007 - Posted: 06.06.2006

Premature babies are much more likely to become hyperactive children than full-term infants, research suggests. Danish researchers found babies born at between 34 and 36 weeks were 70% more likely to develop attention deficit hyperactivity disorder. Those born at less than 34 weeks were three times more likely to have ADHD. The study of 30,000 children in the Archives of Diseases in Childhood also found an increased incidence of ADHD in children with a low birth weight. Previous small studies have shown a link between prematurity and increased risk of ADHD but have only looked at babies born very prematurely - at less than 28 weeks gestation. Researchers used data from Danish national registers to compare the risk of ADHD or the related hyperkinetic disorder and preterm birth in 834 children with the conditions and 20,100 controls. Babies born at term but weighing between 3lb 3oz and 5lb 5oz (1.5kg to 2.5kg) at birth were 90% more likely to develop hyperactivity disorder and ADHD than those of normal weight. A birth weight of 5lb 6oz to 6lb 6oz was associated with a 50% increased risk. Around 90% of the children with hyperkinetic disorder or ADHD were boys. Writing in the journal, Dr Karen Linnet said: "Previous research shows that children born below 28 weeks have an increased risk of ADHD. However, most preterm children are born with higher gestational ages of 28 to 36 weeks. This large population-based study showed that preterm delivery near term and proxy measures of intrauterine growth in children born at or above term increase the risk of hyperkinetic disorder." Charlotte Davies, spokesperson for baby charity Tommy's, said: "Although the correlation between babies who are born prematurely and the increased risk of developing learning difficulties and behavioural problems is well-documented, this study is of particular significance because it has massive implications for the UK. (C)BBC

Keyword: ADHD; Development of the Brain
Link ID: 9006 - Posted: 06.05.2006

Review by ELIZABETH MARSHALL THOMAS Amy Sutherland's title will draw the eyes of animal lovers. We have been kicked, bitten and scratched by the animals who fascinate us, but our interest does not flag, nor do we hold our injuries against those who inflicted them. Far from it — we are eager for more. Sutherland writes of those who are kicked, bitten and scratched under circumstances that many of us might dream of —as students of the Exotic Animal Training and Management Program (EATM) at Moorpark College in Ventura County, Calif. EATM produces specialists who train animals for television and film and hold jobs at aquariums and zoos. Thousands of young people, especially women (who make up an overwhelming majority of students at EATM), long for such careers and wonder how to achieve them. Some will be applying to Moorpark before they finish Sutherland's last chapter. Before they send the application, though, they should read this account of a year at EATM through to the end. Not only do aspiring trainers risk being injured or even killed by animals. They also have to pull the heads off pigeons and put rats in gas chambers — not nice at all, especially for an animal lover, but the captive raptors and reptiles eat the rats and pigeons, and someone has to kill them first. Furthermore, EATM is like boot camp. Roll call is at 6:30 a.m., and students are penalized for every minute they are late. They must clean cages and shovel dung as well as maintain good grades in an academic program. Students must also adhere to a dress code and, if so ordered, let a mandrill pinch them as a safe way of venting his rage. Many will not be able to maintain the pace or tolerate the strict atmosphere and will drop out or be kicked out. But those who complete the program will be ready for meaningful, important jobs. They will not make much money but they will be doing what they love — working with animals. Copyright 2006 The New York Times Company

Keyword: Learning & Memory
Link ID: 9005 - Posted: 06.24.2010

Clear summer skies may cloud our thoughts of air pollution. But however clear the day might be, pollution from cars, trucks and the burning of fossil fuels still abounds. And it doesn't just affect those of us who breathe it. A new study suggests that those who can't breathe yet are also at risk. "Children who had had more exposure in the womb to these combustion-related air pollutants scored significantly lower on the tests for mental development, and were more than twice, almost three times as likely to be developmentally delayed compared to the less exposed children," says environmental health scientist and molecular epidemiologist Frederica Perera. Her research team tested the mental development of 183 New York City kids at ages one, two and three. Their mothers wore air monitors during the final month of pregnancy to measure their exposure to pollutants. "The pollutants we're looking at are extremely widespread, really everywhere, not only in the urban areas but, in the suburban areas as well," she says. "We generate a lot of these pollutants locally, right here out on our streets and highways, we also have pollution from smoke stacks and power plants." © ScienCentral, 2000-2006.

Keyword: Neurotoxins; Development of the Brain
Link ID: 9004 - Posted: 06.24.2010

WASHINGTON -- As part of the effort to develop effective behavioral and medical sleep therapies, scientists consider the potential for dependence and abuse associated with prescription sleep drugs. This line of research has produced findings showing [news] that a recently approved prescription sleep drug may spare users the potential for dependence and abuse found with other sleep aids. Laboratory studies of the effects of ramelteon suggest that the drug's targeting of the brain's melatonin receptors rather than its benzodiazepine receptors make its subjective side effects different from those of old and new sedative hypnotics. The research is reported in the June issue of Behavioral Neuroscience, which is published by the American Psychological Association (APA). At the University of Texas Health Science Center in San Antonio, pharmacology researchers led by Charles P. France, PhD, assessed whether ramelteon instigated the same kinds of broad cognitive effects as other, more commonly prescribed sleep aids. That other group includes traditional hypnotics and newer drugs such as zaleplon (Sonata) and zolpidem (Ambien), all of which bind to the brain's benzodiazepine receptors and may result in impaired thinking, hangover, withdrawal symptoms and rebound insomnia. Laboratory tests and clinical studies also show that even low-dose benzodiazepines, especially in long-term use, create the potential for dependence and abuse. Says Dr. France, "Although medication might not always be indicated for insomnia, when they are prescribed, it is essential to limit the adverse side effects as much as possible."

Keyword: Sleep
Link ID: 9003 - Posted: 06.05.2006

A cannabis plant extract provides pain relief for patients after major surgery, research has shown. An Imperial College London team tested the extract - Cannador - on 65 patients after surgery such as knee replacements and found it helped manage pain. The researchers believe the results could lead to new pain relief drugs, even though the chance of side effects increased with stronger doses. The research appears in the US journal Anesthesiology. Lead researcher Dr Anita Holdcroft said: "Pain after surgery continues to be a problem because many of the commonly used drugs are either ineffective or have too many side effects. "These results show that cannabinoids are effective and may lead to the development of a wider range of drugs to manage post-operative pain." The researchers tested Cannador in different doses on 65 patients who had previously undergone surgery. While all 11 patients who received a 5mg dose of the drug requested additional pain relief, only 15 of the 30 who received the 10mg dose and 6 of the 24 on the 15mg dose did so. However as the dose increased some patients reported increased side effects such as nausea and increased heart rate. Professor Mervyn Maze from Imperial College London, who also worked on the study, said: "We thought cannabis might be beneficial in helping manage pain following surgery, as previous research indicated cannabinoids help 'top up' the body's natural system for reducing pain sensation. "This research proves it can be effective, with minimal side effects at low doses." GW Pharmaceuticals, a Salisbury-based firm, is developing cannabis-based medicines under licence from the UK government. (C)BBC

Keyword: Parkinsons; Drug Abuse
Link ID: 9002 - Posted: 06.03.2006

By Katherine Unger We all know that sinking feeling that comes when we just can't remember someone who clearly recognizes us. So imagine how uncomfortable life might be for a person incapable of recognizing anyone--even a close friend or relative--by face alone. Preliminary results from a recent survey suggest that up to 2% of the general population may be afflicted by this condition, known as prosopagnosia or face blindness. Developmental prosopagnosia, in which an individual has face blindness apparently from birth, was thought to be extremely rare. The first case, in fact, wasn't diagnosed until 1976. But cognitive neuroscientists Bradley Duchaine of University College London and Ken Nakayama of Harvard University say the condition may be far more common than believed. Duchaine and Nakayama decided to use the Internet to measure the prevalence of the condition. They recruited individuals for a barrage of psychological tests, including an online facial recognition survey. Some 1600 participants were first given a relatively easy task. They were "introduced" to an individual's face with pictures flashed on screen for 3 seconds, then presented with three additional photos--one of the prior person and two of other people--and asked to choose the person they had seen before. More difficult tests followed, in which participants were introduced to more faces and then presented with pictures of the same individuals but in different poses in different lighting. © 2006 American Association for the Advancement of Science

Keyword: Miscellaneous
Link ID: 9001 - Posted: 06.24.2010

Claire Ainsworth A simple vitamin supplement in a pregnant mouse's diet can make her offspring fatter, according to research presented on 1 June at the Human Genome Organisation meeting in Helsinki, Finland. The effect is thought to be due to chemical changes made to the mother's DNA, which can be passed down the generations. The study adds to the debate over whether it's a good idea for expectant mothers to up their dietary intake of folic acid, a common supplement used to help lower the incidence of spina bifida. Rob Waterland and his team at the Baylor College of Medicine in Houston, Texas studied the effects of certain compounds in food, including folic acid and vitamin B12. These compounds are known to add chemical constituents called methyl groups to DNA, which affects the activity of genes: part of a phenomenon called 'epigenetics'. Other researchers had already shown that adding methyl donors to a female mouse's diet can influence gene activity in her pups. In mice with a mutation in a coat-colour gene called agouti (the mutation is called agouti variable yellow, or Avy), supplementing the diet of pregnant females turns their pup's coats from yellow to brown. Waterland's team later showed that the supplements did this by methylating a bit of DNA that regulates the agouti gene, which effectively turns off the abnormal gene activity caused by the mutation. ©2006 Nature Publishing Group

Keyword: Obesity
Link ID: 9000 - Posted: 06.24.2010

EAST LANSING, Mich. — Theories about what causes attention deficit hyperactivity disorder, or ADHD, are many and varied, with experts speculating on a wide range of probable causes – genetics, environmental pollutants, food allergies and challenging home environments. In his new book, “What Causes ADHD? Understanding What Goes Wrong and Why,” Michigan State University psychologist Joel Nigg brings together the most recent neuropsychological research in an attempt to answer this challenging question. “Essentially there are multiple causes,” said Nigg. “Some we already know of, others have been suggested and disproved, still others deserve more study.” Nigg, an associate professor of psychology, said that while his book was written mainly for professionals and is a bit technical in places, parents longing for more ADHD information may find it useful, too. “It’s the kind of book that if you want to look something up, it has a specific section on those topics that we know about, such as television watching, diet and so on,” he said. © 2006 Michigan State University Division of University Relations

Keyword: ADHD
Link ID: 8999 - Posted: 06.24.2010

Andy Coghlan Experiments on non-human primates are the only option for some areas of medicine, according to a report published by the UK’s Medical Research Council and the Wellcome Trust on Friday. The report lists medical advances that they claim would have been impossible without experiments on monkeys. The publication of the report looks set to aggravate a bitter propaganda war between pro- and anti-vivisectionists trying to win public support on the issue of primate experiments. On Monday, a report is expected to be launched by the British Union for the Abolition of Vivisection calling for a complete ban on monkey experiments in the UK on moral as well as scientific grounds. At the heart of the debate is a controversial animal testing laboratory under construction at the University of Oxford, which will be used to investigate neurological diseases through experiments on monkeys. It has been the focus of ongoing protests by animal rights campaigners and more recently by pro-vivisection groups such as ProTest. Speaking at a press conference on Friday, Wellcome Trust director Mark Walport told journalists: “No one likes doing primate experiments, but some research can only be done on monkeys.” © Copyright Reed Business Information Ltd.

Keyword: Animal Rights
Link ID: 8998 - Posted: 06.24.2010

ELECTRICITY has long been used to treat medical disorders. As early as the second century AD, Galen, a Greek physician, recommended the use of electric eels for treating headaches and facial pain. In the 1930s Ugo Cerletti and Lucio Bini, two Italian psychiatrists, used electroconvulsive therapy to treat schizophrenia. These days, such rigorous techniques are practised less widely. But researchers are still investigating how a gentler electric therapy appears to treat depression. Vagus-nerve stimulation, to give it its proper name, was originally developed to treat severe epilepsy. It requires a pacemaker-like device to be implanted in a patient's chest and wires from it threaded up to the vagus nerve on the left side of his neck. In the normal course of events, this provides an electrical pulse to the vagus nerve for 30 seconds every five minutes. This treatment does not always work, but in some cases where it failed (the number of epileptic seizures experienced by a patient remaining the same), that patient nevertheless reported feeling much better after receiving the implant. This secondary effect led to trials for treating depression and, in 2005, America's Food and Drug Administration approved the therapy for depression that fails to respond to all conventional treatments, including drugs and psychotherapy. Not only does the treatment work, but its effects appear to be long lasting. A study led by Charles Conway of Saint Louis University in Missouri, and presented to a recent meeting of the American Psychiatric Association, has found that 70% of patients who are better after one year stay better after two years as well. © The Economist Newspaper Limited 2006.

Keyword: Depression
Link ID: 8997 - Posted: 06.24.2010

Early detection of autism is critical for early intervention, yet autism spectrum disorders (ASD) are typically not diagnosed until after three years of age. However, a study published today in the Journal of Child Psychology and Psychiatry found differences between typically developing children and those with ASD are detectable by two years of age. Because there are currently no medical diagnostic tests for autism, identifying developmental disruptions in infants and very young children with ASD may allow for earlier detection and critical intervention. The study examined development in 87 infants at 6, 14 and 24 months of age using a standardized development test. Based on data and clinical judgment at 24 months, participants were classified as: unaffected, language delayed (LD) or ASD. Researchers compared development across groups at the three target ages and observed statistically significant differences between the ASD group and the unaffected group at 14 months. By 24 months, significant differences were detectable between the ASD group and both the unaffected and LD groups. This study and previous research studies conducted by Dr. Landa found that developmental red flags for parents and physicians to watch for include: poor eye contact; reduced responsive smiling; diminished babbling; reduced social responsivity; and difficulty with language development, play and initiating or sustaining social interaction.

Keyword: Autism
Link ID: 8996 - Posted: 06.03.2006

By Katherine Unger The proteins that, when mangled, cause "Mad Cow" and similar diseases also help regulate how yeast cells metabolize metals, biochemists report. Exposure to high levels of metals can coax proteins called prions to adopt an abnormal disease-causing conformation, the researchers found. That could explain why outbreaks of prion diseases have popped up in Iceland, Slovakia, and Colorado--regions with soils high in manganese. Mad Cow disease in cattle, scrapie in sheep, and Creutzfeldt-Jakob disease in humans are all deadly and transmissible conditions in which the brain degenerates. All seemed to be caused by prion proteins that have changed shape so that enzymes can no longer break them down. This altered conformation is widely thought to be responsible for the diseases, because the tangled and essentially indestructible proteins collect in brain tissue (ScienceNOW, July 29 2004). Studies have shown that some metals bind to prion proteins, leading some scientists to wonder whether metals are involved in the shape shift. Now, biochemist Gerd Multhaup of the Free University of Berlin and colleagues have shown that prions alter metal metabolism in yeast. As a first step, they took a species of yeast that does not normally make prions and added prions that don't cause disease. Copper levels increased 1.6-fold inside these cells while manganese decreased by half compared to yeast without prion proteins, the researchers report in a paper to be published 13 June in Biochemistry. The researchers then added copper or manganese to the growth medium to form 1 to 5 millimolar concentrations; both additions transformed the prions to the indestructible form. © 2006 American Association for the Advancement of Science

Keyword: Prions
Link ID: 8995 - Posted: 06.24.2010