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Archive - May 11, 2011

Date

Personalized Medicine 4.0 Conference: Focus on Pharmacogenomics & Consumer Genetic Testing

This year’s Personalized Medicine Conference (4.0) will be held Thursday, May 26 from 8 am to 7 pm at the South San Francisco Conference Center on the campus of San Francisco State University. This fourth annual conference on personalized medicine focuses on two exciting areas – pharmacogenomics (the right drug, at the right dose, for the right patient, at the right time) and the controversial topic of direct-to-consumer genetic testing, examining the science, the business, and the social dimensions of each. Personalized Medicine 4.0 is a one-day conference and networking opportunity for health and industry professionals, educators, and scientists. Learn how the new genomic medicine will affect your work and your life. Seating is limited. Register now at http://personalizedmedicine.sfsu.edu. For additional information or to sponsor this event, please e-mail dnamed@sfsu.edu or call Arlene Essex at 415-405-4107. Advance registration is $495 through 5/16. Save $100 – Early registration is $395 ending soon! Contact us for academic rates.

Evolutionary Adaptations Can Be Reversed, But Rarely

Ever since Charles Darwin proposed his theory of evolution in 1859, scientists have wondered whether evolutionary adaptations can be reversed. Answering that question has proved difficult, partly due to conflicting evidence. In 2003, scientists showed that some species of insects have gained, lost, and regained wings over millions of years. But a few years later, a different team found that a protein that helps control cells’ stress responses could not evolve back to its original form. Dr. Jeff Gore, assistant professor of physics at MIT, says the critical question to ask is not whether evolution is reversible, but under what circumstances it could be. “It’s known that evolution can be irreversible. And we know that it’s possible to reverse evolution in some cases. So what you really want to know is: What fraction of the time is evolution reversible?” he says. By combining a computational model with experiments on the evolution of drug resistance in bacteria, Dr. Gore and his students have, for the first time, calculated the likelihood of a particular evolutionary adaptation reversing itself. They found that a very small percentage of evolutionary adaptations in a drug-resistance gene can be reversed, but only if the adaptations involve fewer than four discrete genetic mutations. The findings will appear in the May 13 issue of the journal Physical Review Letters. Lead authors of the paper are two MIT juniors, Longzhi Tan and Stephen Serene. Dr. Gore and his students used an experimental model system developed by researchers at Harvard University to study the evolution of a gene conferring resistance to the antibiotic cefotaxime in bacteria. The Harvard team identified five mutations that are crucial to gaining resistance to the drug.

Beneficial Bacteria Help Repair Intestinal Injury by Inducing Reactive Oxygen Species

The gut may need bacteria to provide a little bit of oxidative stress to stay healthy, new research suggests. Probiotic bacteria promote healing of the intestinal lining in mice by inducing the production of reactive oxygen species, researchers at Emory University School of Medicine have shown. The results, published online on May 9, 2011, in PNAS, demonstrate a mechanism by which bacterial cultures in foods such as yogurt and kimchi have beneficial effects on intestinal health. The insights gained could also guide doctors to improved treatments for intestinal diseases, such as necrotizing enterocolitis in premature babies or intestinal injury in critically ill adults. The laboratories of Dr. Andrew Neish and Dr. Asma Nusrat, both professors of pathology and laboratory medicine, teamed up for the study. The paper’s co-first authors are postdoctoral fellow Dr. Philip Swanson and associate research professor Dr. Amrita Kumar. “It’s been known for years that probiotic bacteria can have these kinds of helpful effects, but it wasn’t really clear how this worked,” Dr. Neish says. “We’ve identified one example, among many, of how certain kinds of bacteria have specific biochemical functions in the body.” Recent research has shown that the bacteria in our intestines influence our metabolism and immune systems. For example, an imbalance in the proportions of harmful and beneficial bacteria seems to over-activate immune cells in the intestines, driving inflammatory bowel disease. Intestinal epithelial cells, the cells that line the intestine, live in close contact with bacteria and normally form a barrier that keeps bacteria away from other organs. They can repair small gaps in the barrier, which breaks down in intestinal diseases, by migrating into the gaps.