By Jennifer Viegas, Discovery News — Seasonal changes cause fat to shift locations in our body, thus altering the shape of our figures at certain times of the year, according to a new study. Varying testosterone levels drive the shape changes, the study suggests. The hormone, often associated with brawn and aggressiveness, fluctuates over the seasons in both men and women. The most evident changes occur within the waist and hip region, the study determined. When testosterone levels rose, women became less curvy as fat shifted toward the waist. Other research has determined that the opposite happens in men, who retain more fat in the abdominal region when testosterone levels fall. The scientists examined seasonal testosterone fluctuations in the saliva of 220 women and 127 men. They also measured the waists and hips of the female study participants over the seasons. "We found that women’s and men’s testosterone is highest in the fall," said Sari van Anders, who led the research. "As well, women’s waist-to-hip ratio (how big the waist is relative to the hips) is highest during the fall, and central measures of fat deposition, like abdominal fat, were also somewhat higher in the fall (for women)." © 2006 Discovery Communications Inc.

Keyword: Biological Rhythms; Hormones & Behavior
Link ID: 9026 - Posted: 06.24.2010

Rowan Hooper A DNA vaccine has successfully reduced the symptoms of Alzheimer's disease in mice. The result could signal the first preventative and restorative treatment vaccine for Alzheimer’s without serious side effects. Alzheimer’s disease progresses as small proteins called amyloid beta (Ab) peptides are overproduced, forming plaques in the brain that interfere with its function. Memory loss and mental deterioration follow. A vaccination approach – getting the immune system to clean up the plaques – has been considered the most promising way to tackle the disease, but its success has been limited, until now. In 2002, for example, the US pharmaceutical company Elan halted trials of a vaccine that raised antibodies against Ab peptides, after some patients suffered brain inflammation (see Key Alzheimer's vaccine trial abandoned). The new vaccine is different because instead of using the Ab peptide itself to stimulate antibody production, it uses a stretch of DNA that codes for the Ab peptide, says Yoh Matsumoto, at the Tokyo Metropolitan Institute for Neuroscience, Japan, who led the research. Since DNA vaccination stimulates the immune system more gently than peptide vaccination, it should also avoid the brain swelling seen in the Elan trial. © Copyright Reed Business Information Ltd

Keyword: Alzheimers
Link ID: 9025 - Posted: 06.24.2010

Certain variants of a simple sugar ameliorate Alzheimer's-like disease in mice, according to a new study by Canadian researchers. Although the new studies are still in the early stages, the findings could lead to new therapies that prevent or delay the onset of Alzheimer's disease. The new studies show that some types of a sugar called cyclohexanehexol—also known as inositol—prevented the accumulation of amyloid â deposits, a hallmark of Alzheimer's disease. Scyllo-inositol treatment also improved cognitive abilities in the mice and allowed them to live a normal lifetime. The study appeared in advance online publication of the journal Nature Medicine on June 11, 2006. HHMI international research scholar and senior author Peter St George-Hyslop cautioned that the chemicals tested in these studies are not the type of inositol sold commercially as a nutritional supplement. That type—myo-inositol—has been shown previously to be ineffective at breaking up amyloid aggregates, he said. In the brain of a person with Alzheimer's disease, small proteins called amyloid â aggregate into plaques, and a protein called tau clumps into neurofibrillary tangles. The brain becomes inflamed and neurons atrophy and die. It's not completely clear what kind of amyloid â peptide (monomers, oligomeric aggregates, or fibrillar aggregates) is responsible for the onset of disease, said St George-Hyslop of the University of Toronto. "Because we were able to show that scyllo-inositol specifically dispersed the high-molecular-weight oligomeric aggregates, this study confirms that the initiating event is the accumulation of oligomeric aggregates of amyloid â peptide,” he said. © 2006 Howard Hughes Medical Institute.

Keyword: Alzheimers
Link ID: 9024 - Posted: 06.24.2010

By Joel Garreau Studying with diligent friends is fine, says Heidi Lessing, a University of Delaware sophomore. But after a couple of hours, it's time for a break, a little gossip: "I want to talk about somebody walking by in the library." One of those friends, however, is working too hard for dish -- way too hard. Instead of joining in the gossip, "She says, 'Be quiet,' " Lessing says, astonishment still registering in her voice. Her friend's attention is laserlike, totally focused on her texts, even after an evening of study. "We were so bored," Lessing says. But the friend was still "really into it. It's annoying." The reason for the difference: Her pal is fueled with "smart pills" that increase her concentration, focus, wakefulness and short-term memory. As university students all over the country emerge from final exam hell this month, the number of healthy people using bootleg pharmaceuticals of this sort seems to be soaring. Such brand-name prescription drugs "were around in high school, but they really exploded in my third and fourth years" of college, says Katie Garrett, a 2005 University of Virginia graduate. © 2006 The Washington Post Company

Keyword: Drug Abuse; Learning & Memory
Link ID: 9023 - Posted: 06.24.2010

By N. R. KLEINFIELD Dr. John Newcomer is a psychiatrist who generally treats people with severe ailments of the mind and spirit. But before his patients sit down, before he hears about their clammy paranoia or renegade voices, Dr. Newcomer wants to know about their waist size. He steers them to a scale to learn their weight. He orders a blood sugar test. If big numbers come up, he begins a conversation about Type 2 diabetes, a disease associated with obesity that is appearing with alarming frequency among the mentally ill. "Uncontrolled diabetes can ruin a person's life as much as uncontrolled schizophrenia," said Dr. Newcomer, a professor of psychiatry at Washington University School of Medicine in St. Louis. In fact, among the mentally ill, roughly one in every five appear to develop diabetes — about double the rate of the general population. This is a little-recognized surge, but one that is jolting mental health professionals into rethinking how they care for an often neglected population. For decades, psychiatrists have worried primarily about patients' mental states, making sure they did no harm to themselves or others because of unrelenting voices or a smothering depression. Copyright 2006 The New York Times Company

Keyword: Schizophrenia; Obesity
Link ID: 9022 - Posted: 06.24.2010

By Virginia Hughes A few years ago, scientists found that the common fruit fly, Drosophila melanogaster, sleeps in a remarkably human-like way. Now a new study on fruit fly brains shows that a specific brain region—previously linked to the fly's memories of smell—is also vital to sleep. These results support the idea that memory consolidation may play a big part in fly sleep, and, likely, human sleep. "The link between sleep and learning a lot of people can identify with – particularly college students who pull all-nighters," says lead researcher Jena Pitman of Northwestern University, "But that link is pretty universal." Might a sleeping fruit fly be digesting the memory of a rotten banana it ate for dinner? Fruit flies and humans share many of what scientists call the "essential features" of sleep. Both species sleep for many hours at night, for instance, says Ravi Allada, one of the other neuroscientists involved in the study. With flies, too, as Allada explains, "the longer they're asleep, the harder you have to poke them to get them to wake up." If you deprive them of sleep, flies will try to catch up on sleep the next day. And fly sleep patterns respond to some drugs in the same way we do: antihistamines make them drowsy and caffeine keeps them awake. This all suggests that "the mechanism of sleep is very similar" in fruit flies and humans, says Allada. Though the similarities between fly sleep and human sleep were well-established a few years ago, no one had studied the specific fly brain regions involved in sleeping until now. The latest Northwestern study, published in Nature on June 7, sought to figure out which part of the brain—if any—could be isolated for sleep studies. © 2005 Discover Media LLC.

Keyword: Sleep
Link ID: 9021 - Posted: 06.24.2010

Bruce Bower A mental disorder that encompasses a wide range of recurring, hostile outbursts, including domestic violence and road rage, characterizes considerably more people than previous data had indicated, a national survey finds. At some point in their lives, between 5.4 percent and 7.3 percent of U.S. adults qualify for a diagnosis of intermittent explosive disorder, concludes a team led by sociologist Ronald C. Kessler of Harvard Medical School in Boston. Those percentages, which depend on whether the syndrome is narrowly or broadly defined, correspond to between 11.5 million and 16 million people, respectively. In any given year, intermittent explosive disorder affects between 2.7 percent and 3.9 percent of adults, or from 5.9 million to 8.5 million people, Kessler and his coworkers report. "We never thought we'd find such high prevalence rates for this condition," Kessler says. In contrast, a 2004 study of 253 Baltimore residents estimated a lifetime prevalence of 4 percent for intermittent explosive disorder. Intermittent explosive disorder features tirades, grossly disproportionate to the triggering circumstances, during which a person destroys property, tries to hurt or actually hurts someone, or threatens to do so. The expression of rage elicits a sense of relief, followed by remorse for the incident. The syndrome doesn't include outbursts that stem from other mental disorders or from alcohol or drug effects. ©2006 Science Service.

Keyword: Emotions; Aggression
Link ID: 9020 - Posted: 06.24.2010

New therapies for stroke patients may soon be possible, thanks to a discovery made by a team of University of British Columbia neuroscience researchers who have found a new stroke death channel -- the conduit through which key chemicals are lost from brain cells during stroke, causing the cell death that disables stroke victims. The findings were published recently in Science and will be the subject of an editorial in next month’s issue of Nature Reviews Neuroscience. “We’ve known for 40 years about chemicals flowing out of cells after stroke, but nobody knew the exact process -- so we went looking for the death channel. And we found it,” says Roger Thompson, a UBC Psychiatry post-doctoral Fellow who made the discovery, along with graduate student Ning Zhou and Psychiatry Prof. Brian MacVicar, all members of the Brain Research Centre at UBC Hospital and of Vancouver Coastal Health Research Institute. The researchers found, in animal models, that brain cell membranes were disrupted at the site of gap junction hemichannels. Gap junctions are connections that allow molecules and ions to flow between cells. Junctions are composed of two hemichannels that bridge the intercellular space. Until now, scientists believed the disruption to occur at the site of glutamate channels. Glutamate is one of the brain’s most abundant chemical messengers. However, therapeutic strategies targeted at glutamate channels failed to prevent brain cell death. © Copyright The University of British Columbia

Keyword: Stroke
Link ID: 9019 - Posted: 06.24.2010

Roxanne Khamsi The next time you listen to the Beatles sing “Michelle” you can thank an area of your brain called the left caudate. It could be what enables you to follow the lyrics as they switch from English to French, claim researchers at University College London in the UK. Previous brain-scan research into how the brain flips from one language to another has failed to identify any one region responsible, suggesting that the neural circuits for different languages are highly overlapping in the brain. Now Cathy Price and her colleagues have combined brain scans with behavioural tests and discovered that the left caudate becomes more active as people shift from thinking in one language to another. This area is thought to influence how we articulate words in association with another brain structure known as the thalamus. The research team recruited 35 bilingual people – 25 spoke German and English, 10 spoke Japanese and English. The participants viewed pairs of words while undergoing brain scans using either positron emission tomography (PET) or functional magnetic resonance (fMRI) imaging. When volunteers read two words with the same meaning but in different languages, or two words in the same language with unrelated meanings, the left caudate region in their brains became more active than when they read two words from the same language with a similar theme. This held true across both language groups. © Copyright Reed Business Information Ltd.

Keyword: Language
Link ID: 9018 - Posted: 06.24.2010

A federally funded team of researchers including several from Johns Hopkins have identified six regions of the human genome that might play a role in susceptibility to obsessive compulsive disorder, or OCD. The study was published online June 6 in Molecular Psychiatry. "OCD once was thought to be primarily psychological in origin," says Yin Yao Shugart, Ph.D., statistical geneticist and associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. "But now there is growing evidence that there is a genetic basis behind OCD, which will help us better understand the condition," she says. OCD is characterized by intrusive and senseless thoughts and impulses that together are defined as obsessions, as well as repetitive and intentional behaviors, referred to as compulsions. OCD is estimated to affect up to 3 percent of the American population. In what the research team describes as the first whole-genome scan to look for genetic "markers" or similarities in the genomes of people with OCD, results identified six potentially significant regions in the genome, which lie on five different chromosomes that appear "linked" to OCD. It's likely that any genes directly associated OCD are to be found in these regions. "We've long suspected that, rather than being caused by a single gene, OCD has multiple genetic associations," says Jack Samuels, Ph.D., an epidemiologist and assistant professor of psychiatry at the Johns Hopkins School of Medicine.

Keyword: OCD - Obsessive Compulsive Disorder; Genes & Behavior
Link ID: 9017 - Posted: 06.10.2006

In a new study published in the latest issue of Ethology researchers show that female songbirds can alter the size of eggs and possibly the sex of their chicks according to how they perceive their mate's quality. The researchers played back attractive ("sexy") songs and less attractive control songs of male canaries to female domesticated canaries. When the females started egg-laying they varied the size of their eggs in the nest according to the attractiveness of the male's song. That is, the more attractive the song, the larger the eggs. However it is remarkable that while larger eggs were more likely to contain male offspring in natural environments, in the experiment there was no difference in brood sex ratio between the different songs played to the females, which suggests different levels of female control. Male birdsong has long been known to attract females and influence mate choice decisions and even induce an alteration in the offspring's sex ratio. This study by Leitner et al. now shows experimentally that hearing attractive song also has a selective impact on female physiology. 45 female domesticated canaries participated in this study that was a collaboration of Royal Holloway, University of London and the Max Planck Institute for Ornithology in Seewiesen and Radolfzell in Germany. The birds were kept in large aviaries where their daily behaviour was monitored in a colony before they were tested in the song experiments. The females showed a remarkable consistency in their behavioural and reproductive performance and the song stimuli alone were sufficient to elicit a profound physiological change. This study further highlights the importance of behavioural stimuli for reproductive physiology. Bathroom Pavarottis beware.

Keyword: Sexual Behavior; Animal Communication
Link ID: 9016 - Posted: 06.10.2006

With help from some drowsy fruit flies, a team of researchers from the Howard Hughes Medical Institute (HHMI) at the University of Pennsylvania School of Medicine has identified a region of the fruit fly's brain that is crucial to controlling sleep. The finding, reported in the June 8, 2006, issue of the journal Nature, is important because it identifies a new role for brain structures, called mushroom bodies, which have now been shown to control fruit fly slumber. Mushroom bodies were known to be involved in processing sensory information and memory. Thus, the new studies lend support to the idea that sleep helps the brain consolidate learning and memory. “We spend one-third of our lives sleeping, but we know very little about sleep and how it is regulated,” explained Amita Sehgal, the senior author of the new Nature paper and an HHMI investigator at the University of Pennsylvania School of Medicine. “It's really pretty amazing that we know so little.” Sleep, in fact, is such a mystery that scientists are not even sure why animals require it. No purpose or underlying mechanism for the phenomenon has ever been proven. And while the new Nature report does not delve directly into the mysteries of why animals snooze, the findings support the idea that one of sleep's essential roles is to limit sensory input so the brain can organize and crystallize the day's memories for storage and future retrieval. © 2006 Howard Hughes Medical Institute.

Keyword: Sleep
Link ID: 9015 - Posted: 06.24.2010

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