Pilocytic astrocytoma (PA) is the most common pediatric brain tumor, and there are few medical therapies available to those patients for whom surgery is not curative. However, it has been difficult to design targeted PA therapies because the cellular mechanisms that lead to the cancer are incompletely understood, and there is no animal model of the disease. Recent work has suggested that activation of a particular cell signaling pathway may be required for PA formation, and mutations in one gene in that pathway, a kinase called BRAF, are found in more than half of all ...

EDITOR'S PICK An inside look at how the elite control HIV In the years since the AIDS epidemic began, it has become clear that there is substantial variation in the way that individuals respond to HIV infection. Although most progress quickly from initial infection to immunodeficiency, a small subset survive for long periods without developing symptoms. These patients, dubbed elite controllers, display undetectable levels of viral replication, but the mechanism that explains how their immune systems effectively control the virus is not understood. In this paper, Mathias ...

Elevated levels of p21, a protein best known as a cancer fighter, may be involved in the ability of a few individuals to control HIV infection with their immune system alone. In a paper in the April edition of the Journal of Clinical Investigation, researchers from the Massachusetts General Hospital (MGH) Infectious Disease Division and the Ragon Institute of MGH, MIT and Harvard report that CD4 T cells from HIV controllers, while capable of being infected, can effectively suppress key aspects of the viral life cycle, an ability that may be associated with increased expression ...

A variety of plant seedlings suffer most from competition when planted with close relatives, and grow best when planted alongside distant relatives in field soils, researchers from Case Western Reserve University and the University of California, Davis, have found. And, when seeds of the same species are buried among relatives in the field, the seeds germinate at a higher rate and grow better early in life in close relatives' habitats than distant relatives' habitats. The work will be published in the Proceedings of the National Academy of Sciences March 14. The findings, ...

According to classical ecology, when two species compete for the same resource, eventually the more successful species will win out while the other will go extinct. But that rule cannot explain systems such as the Amazon, where thousands of tree species occupy similar ecological niches. The childhood game of rock-paper-scissors provides one solution to this puzzle, report researchers at the University of Chicago and the University of California, Santa Barbara in Proceedings of the National Academy of Sciences. A mathematical model designed around the game's dynamics produced ...

Mark Twain called it "the most delicious fruit known to man." But the cherimoya, or custard apple, and its close relations the sugar apple and soursop, also have lots of big, awkward seeds. Now new research by plant scientists in the United States and Spain could show how to make this and other fruits seedless. Going seedless could be a big step for the fruit, said Charles Gasser, professor of plant biology at UC Davis. "This could be the next banana -- it would make it a lot more popular," Gasser said. Bananas in their natural state have up to a hundred seeds; all ...

Bariatric surgery can result in long-term weight loss and significant reductions in cardiac and other risk factors for some severely obese adults, according to a scientific statement from the American Heart Association. The statement, published in Circulation: Journal of the American Heart Association, is the first by the American Heart Association focused solely on bariatric surgery and cardiac risk factors, according to lead author Paul Poirier, M.D., Ph.D., director of the prevention/rehabilitation program at Quebec Heart and Lung Institute at Laval University ...

In the run up to World Malaria Day on the 25th April 2011, BioMed Central's open access journal Malaria Journal takes a long hard look at the development of natural compounds for use in the fight against malaria. There are over 200 million cases of malaria each year with 85% of all cases being children under five years old and, according to the World Health Organisation, in 2009 malaria was responsible for 781,000 deaths worldwide. Low cost treatment is available, 100 million children a year are treated with Artemisinin combination therapy at a cost of about 30 cents ...

A new legal high has emerged that seems to be replacing the banned substance mephedrone or "miaow miaow", warns a critical care paramedic in Emergency Medicine Journal. Mephedrone was banned in England, when it was reclassified as a class B drug in April 2010. The new drug in circulation is "ivory wave," also known as "purple wave," "ivory coast," or "vanilla sky." And its use has already been implicated in hospital admissions and deaths in various parts of England, says the author. Ivory wave is usually sold online as bath salts in packets of between 200 and 500 ...

Heavy drinking is not associated with one of the two most common types of gullet (oesophageal) cancer, suggests research published online in Gut. Gullet cancer is the sixth leading cause of cancer death worldwide and occurs as one of two main types: squamous cell carcinoma or adenocarcinoma. But while rates of gullet adenocarcinoma have soared in many Western countries over the past three decades, those of squamous cell carcinoma have been falling. The squamous cell variety is strongly linked to alcohol consumption. The authors pooled data from 11 international studies, ...

The impact on mental health of a badly paid, poorly supported, or short term job can be as harmful as no job at all, indicates research published online in Occupational and Environmental Medicine. Because being in work is associated with better mental health than unemployment, government policies have tended to focus on the risks posed by joblessness, without necessarily considering the impact the quality of a job may have, say the authors. They base their findings on seven waves of data from more than 7000 people of working age, drawn from a representative national ...

COLUMBUS, Ohio – A new study in Honduras suggests that climate-related weather disasters may sometimes actually provide opportunities for the rural poor to improve their lives. Researchers found that that the poorest inhabitants of a small village in northeastern Honduras increased their land wealth and their share of earnings relative to more wealthy residents after Hurricane Mitch devastated their village in October 1998. The findings offer a glimmer of hope from widespread concerns that the world's poor will suffer the most from shocks created by global climate change. "In ...

The research, published today (Tuesday March 15 2011) in The Journal of Physiology, shows a definite link between maternal and offspring obesity and is the first demonstration that this is the case in mammals which bear 'mature offspring' – as humans do. Professor Peter Nathanielsz, lead author of the research, said: "A relationship between maternal obesity and offspring obesity has been clearly identified in rodents but as their young are born immature, it was not clear whether the findings would apply to humans. "Lambs offer a more similar model to understand the ...

A new study involving the University of Colorado Boulder shows clear evidence of the continuous control of fire by Neanderthals in Europe dating back roughly 400,000 years, yet another indication that they weren't dimwitted brutes as often portrayed. The conclusion comes from the study of scores of ancient archaeological research sites in Europe that show convincing evidence of long-term fire control by Neanderthals, said Paola Villa, a curator at the University of Colorado Museum of Natural History. Villa co-authored a paper on the new study with Professor Wil Roebroeks ...

An inexpensive type 2 diabetes drug that has been around for more than 15 years works just as well and has fewer side effects than a half-dozen other, mostly newer and more expensive classes of medication used to control the chronic disease, new Johns Hopkins research suggests. In their report, published online March 14 in the journal Annals of Internal Medicine, the Hopkins team found that metformin, an oral drug that was first approved by the U.S. Food and Drug Administration in 1995, not only controlled blood sugar, but was also less likely to cause weight gain or ...

SEATTLE – A wealth of maternal and child health data is being made immediately and freely accessible through a new collaboration between the Institute for Health Metrics and Evaluation (IHME) and the Centers for Disease Control and Prevention's (CDC) Division of Reproductive Health. The Division chose IHME's Global Health Data Exchange (GHDx) to host its reports and datasets for an extensive series of reproductive health survey data from more than 30 countries that have received technical assistance from the Division from 1975 to the present. The datasets cover a wide ...

CHICAGO – Heavy alcohol consumption, specifically three or more glasses of liquor a day, is associated with an increased risk of death from pancreatic cancer, according to a report in the March 14 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. "Alcoholic beverage consumption – a modifiable lifestyle factor – is causally related to several cancers, including oral cavity, pharynx, larynx, esophagus, liver, colorectum and female breast," the authors write as background information in the article. "Heavy alcohol consumption causes acute and chronic ...

CHICAGO -- A meta-analysis of nine previous studies found that quitting smoking shortly before surgery was not associated with an increased risk of postoperative complications, according to a report published online today that will appear in the July 11 print issue of Archives of Internal Medicine, one of the JAMA/Archives journals. "Cigarette smoking has been implicated as a risk factor for postoperative complications across a spectrum of surgical specialties," the authors provide as background information. "Compared with nonsmokers, smokers who undergo surgery have ...

CHICAGO – Patients with a recent onset of Parkinson disease have a high prevalence of vitamin D insufficiency, but vitamin D concentrations do not appear to decline during the progression of the disease, according to a report in the March issue of Archives of Neurology, one of the JAMA/Archives journals. Vitamin D is now considered a hormone that regulates a number of physiological processes. "Vitamin D insufficiency has been associated with a variety of clinical disorders and chronic diseases, including impaired balance, decreased muscle strength, mood and cognitive ...

CHICAGO – Regular consumption of fish and omega-3 fatty acids found in fish is associated with a significantly reduced risk of developing age-related macular degeneration in women, according to a report posted online today that will appear in the June issue of Archives of Ophthalmology, one of the JAMA/Archives journals. "An estimated nine million U.S. adults aged 40 years and older show signs of age-related macular degeneration (AMD)," the authors write as background information in the article. "An additional 7.3 million persons have early age-related macular degeneration, ...

CHICAGO – Patients with a disease known as retinal vein occlusion (RVO) have a significantly higher incidence of stroke when compared with persons who do not have RVO, according to a report in the March issue of Archives of Ophthalmology, one of the JAMA/Archives journals. "Retinal vein occlusion (RVO) is a retinal vascular disease in which a retinal vein is compressed by an adjacent retinal artery, resulting in blood flow turbulence, thrombus formation, and retinal ischemia," the authors write as background information in the article. "Although RVO is a significant cause ...

Children express the stereotype that mathematics is for boys, not for girls, as early as second grade, according to a new study by University of Washington researchers. And the children applied the stereotype to themselves: boys identified themselves with math whereas girls did not. The "math is for boys" stereotype has been used as part of the explanation for why so few women pursue science, mathematics and engineering careers. The cultural stereotype may nudge girls to think that "math is not for me," which can affect what activities they engage in and their career ...

Scientists from Monash University have uncovered a new understanding of how male puberty begins. The key to their findings lies with a protein known as SMAD3 and the rate at which it is produced. Researchers, Associate Professor Kate Loveland and Dr Catherine Itman from the Faculty of Medicine, Nursing and Health Sciences have discovered through laboratory testing that half as much SMAD3 protein results in faster maturation than the norm, and an inability to create SMAD3 results in abnormal responses to testosterone. "SMAD3 is a protein that translates signals from ...

Alum is an adjuvant (immune booster) used in many common vaccines, and Canadian researchers have now discovered how it works. The research by scientists from the University of Calgary's Faculty of Medicine is published in the March 13 online edition of Nature Medicine. The new findings will help the medical community produce more effective vaccines and may open the doors for creating new vaccines for diseases such as HIV or tuberculosis. "Understanding alum properties will help other vaccines because we are one step deeper into the mechanistic insight of adjuvants, ...

Research into how the brain transmits messages to other parts of the body could improve understanding of disorders such as epilepsy, dementia, multiple sclerosis and stroke. Scientists at the University of Edinburgh have identified a protein crucial for maintaining the health and function of the segment of nerve fibres that controls transmission of messages within the brain. The study, published in the journal Neuron, could help direct research into neurodegenerative disorders, in which electrical impulses from the brain are disrupted. This can lead to inability to ...