Medicine

Whale sharks -- giants of the fish world that strike terror only among tiny creatures like the plankton and krill they eat -- are imperiled by over-fishing of the species in parts of its ocean range. That threat is underscored in a new study from geneticists led by Jennifer Schmidt, University of Illinois at Chicago associate professor of biological sciences, reported online April 7 in the journal PLoS One. Schmidt and her colleagues studied the DNA of 68 whale sharks from 11 locations across the Indian and Pacific Oceans and the Caribbean Sea -- an area that covers most of the shark's known…

It's basically a given that diets loaded with fat can lead to considerable health problems. But a new study in the April issue of Cell Metabolism, a Cell Press publication, shows that in some cases diets that are high in both fat and protein can be even worse. The researchers led by Christopher Newgard of Duke Medical Center report that rats fed high-fat (HF) diets supplemented with extra so-called branched chain amino acids (BCAA) don't have to eat as much or gain as much weight to develop insulin resistance as do chubbier animals fed a high-fat diet alone. Moreover, those ill effects of…

BOSTON – April 7, 2009 – Researchers at the Joslin Diabetes Center have shown for the first time that insulin plays a key role in suppressing levels of glucagon, a hormone involved in carbohydrate metabolism and regulating blood glucose levels. The study helps in the understanding of why those with diabetes have high blood glucose levels and could lead to development of a drug aimed at targeting glucagon levels. "This is a very important finding because until now scientists have only speculated that insulin may be involved in keeping glucagon levels in check," said Rohit N. Kulkarni, M.D.,…

During the past few years, several new genetic risk factors for rheumatoid arthritis (RA) have been identified. The majority of genetic risk factors identified so far have been associated with autoantibody-positive RA, which affects about two-thirds of RA patients, but distinguishing this variant from autoantibody-negative RA, which is less destructive, is considered increasingly important. A new study led by Diane van der Woude of Leiden University Medical Center in The Netherlands examined 148 twin pairs in which one twin had RA. Participants were tested for antibodies known as anti-…

Waterdogs, they're called, these larvae of tiger salamanders used as live bait for freshwater fishing. With tiger salamander larvae, anglers hope to catch largemouth bass, channel catfish and other freshwater fishes. They may be in for more than they bargained for: salamanders in bait shops in Arizona, Colorado and New Mexico are infected with ranaviruses, and those in Arizona, with a chytrid fungus called Batrachochytrium dendrobatidis (Bd). "These diseases have spread with the global trade in amphibians,'" says James Collins, assistant director for biological sciences at the National…

NEW BRUNSWICK, N.J. – Rutgers geneticist Linda Brzustowicz and her colleagues have identified a specific DNA change that is likely to increase risk for developing schizophrenia in some people. It provides a potential mechanism that may be a point of entry for drug therapy, consistent with the growing trend of personalized medicine. The research findings are reported in the April issue of the American Journal of Psychiatry (AJP). An accompanying editorial highlights the significance of this work. Brzustowicz, a professor of genetics at Rutgers, The State University of New Jersey, and board-…

Scientists at the University of Melbourne have discovered the local action of immune cells in the skin, which could improve treatment of viral skin infections. This work identifies previously unrecognised first-line defence mechanisms that are particularly important in barrier locations such as the skin and the gut, often used as portals of entry by viruses and bacteria. Researchers examined two aspects of anti-viral immune responses by studying the cells involved in the initial stimulation of the immune response, and the cells that remember past infections to boost the response after…

Killing only older mosquitoes could be a more sustainable way of controlling malaria, and has the potential to lead to evolution-proof insecticides that never become obsolete, according to an article in this week's issue of PLoS Biology. Each year, malaria – spread through mosquito bites – kills around a million people, and many of the chemicals used to kill the insects become ineffective as the mosquito's resistance to them evolves. New theoretical work, by Andrew Read and Matt Thomas (both at Penn State), and Penelope Lynch (Open University, UK), predicts that simple changes to the way…

LA JOLLA, CA—About 1.25 million neurons in the retina -- each of which views the world only through a small jagged window called a receptive field -- collectively form the seamless picture we rely on to navigate our environment. Receptive fields fit together like pieces of a puzzle, preventing "blind spots" and excessive overlap that could blur our perception of the world, according to researchers at the Salk Institute for Biological Studies. In the April 7 issue of the journal Public Library of Science, Biology, the scientists say their findings suggest that the nervous system operates with…

EDITOR'S PICK: Separating the beneficial effects of a drug from the adverse side effects Nicotinic acid is one of the most effective drugs for raising levels of "good" cholesterol and lowering levels of "bad" cholesterol and other lipids (fats), thereby reducing the risk of heart attack. However, patients often stop taking the drug due to one specific side effect, flushing of the skin that often includes an intense burning and itching sensation. A way to separate the beneficial effects of nicotinic acid from the flushing response has now been elucidated in mice by Robert Lefkowitz and…