ScienceCache

Vol. 152
Oct. 30, 2003

TREATING BLOOD CLOTS, A HALF-CENTURY LATER
The first new oral drug in 50 years to prevent blood clots after knee-replacement surgery was superior to the standard treatment in an international clinical trial of about 2,300 patients led by Charles Francis, professor of medicine and pathology and laboratory medicine. Researchers also have tested the new drug, ximelagatran, for prevention of stroke, heart attacks and deep vein thrombosis, and if approved by the FDA it would offer millions of patients an alternative to the commonly prescribed anticoagulant, warfarin. Francis says ximelagatran has now been studied in some 17,000 patients during the past five years. The compound was developed as an alternative to oral warfarin (brand name: Coumadin), in an effort to find a drug that was easier for patients and doctors to manage. Warfarin requires constant laboratory monitoring, and has a long list of side effects and food and drug interactions. Studies show ximelagatran is absorbed quickly, does not require adjustments or close monitoring, and has no food or drug interactions. “Coumadin is a fine drug, but lots of people don’t do well on it,” Francis says. “We’ve been 50 years with no alternative and now it looks like we have one.” The results of the study are reported in today’s issue of the New England Journal of Medicine, which in this issue paid special attention to scientific advances in the treatment of blood clots, or thrombosis. Francis’ study took place at 116 medical centers in the United States, Canada, Israel, Mexico and Brazil.
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MERCURY EXPOSURE RISKS REVIEWED BY TOP EXPERTS
Today’s New England Journal of Medicine also includes a review article on the toxicology of mercury by Thomas Clarkson and Gary Myers of the university, along with Laszlo Magos of the Medical Research Council Laboratories in the United Kingdom. The three discuss the risks of mercury from three major sources: fish consumption, dental amalgams, and vaccines. More than 30 years ago the Rochester team, based on a grain-poisoning event in Iraq, put together the first precise data showing that pre-natal exposure to high levels of mercury could harm a developing child. Since then the team has carried out extensive studies to try to pinpoint the levels at which mercury poses a danger. Earlier this year the group published its findings from a study of 643 children showing no detectable risk from the low levels of mercury their mothers were exposed to from eating ocean seafood. And last year another Rochester team led by Michael Pichichero showed that blood levels of mercury in children who received vaccines containing the preservative thimerosal are comfortably below current safety limits. The group is continuing these studies and is looking at the possible effects from mercury contained in most dental fillings, though they say “there is no clear evidence supporting the removal of amalgams.” In today’s review article, the team weighs the unproven risk from low mercury levels to the risks of avoiding vaccination, eliminating seafood from the diet and eliminating other sources of mercury, and concludes, “…..attempts to reduce such exposure may post greater health risks than those hypothesized to occur from mercury.”

BONE CELLS HELP CALL THE SHOTS FOR THE BLOOD’S STEM CELLS WITHIN
Just as oak barrels don’t simply hold fine wine but also play a vital role in its aging and development, scientists have discovered that bones nurture and control blood development in the bone marrow within to a profound extent. In some sense the finding may not seem startling – after all, it’s long been known that the bone marrow that is the source of all our blood cells is in the center of our longest bones. But the team’s paper in last week’s issue of the journal Nature is the first to pinpoint the role of bone forming cells in controlling the expansion of blood-forming stem cells, and to identify a way to multiply such cells without pushing them along toward their ultimate cell fate. The finding could be important for bone-marrow-transplant patients, for whom a limit in stem cells often makes the procedure more dangerous if not impossible. By exploiting their knowledge of the bone’s role in the creation of blood cells, the team was able to create mice that were nearly four times as likely to survive a difficult transplant as other mice. The bone marrows of the treated mice looked much healthier and were more densely packed with blood cells. “This started as a rather improbable project, a side project that became more and more interesting as we made our findings,” says endocrinologist Laura Calvi, the first author. “It’s especially exciting because the compound we used is already known to work safely in people, so we can start looking quickly to see whether this strategy will work in people too.”
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INNOVATORS RECOGNIZED AT THE MEDICAL CENTER
Tuesday afternoon in the Arthur Kornberg Medical Research Building, the medical center honored 32 of its researchers who have been awarded patents in the past three years. The inventions are part of a collection of intellectual property that brought to the University $42 million in royalties this year, placing the institution seventh among universities nationwide. The importance of the discoveries goes far beyond the dollars earned – they make very real differences in the quality of the lives of patients in Rochester and oftentimes around the globe. Such is true of the vaccine against childhood meningitis, which has prevented tens of thousands of cases of the oft-fatal disease. Among the honorees: Yan Yu, who developed a better way to plan treatment for patients with prostate cancer; Patricia Rodier, Susan Hyman and Christopher Stodgell, for their discovery of a gene that may be linked to autism; Charles Duffy, for a new system to detect Alzheimer’s disease early by measuring a person’s ability to detect motion; Ruola Ning, for new computerized tomography or CT technology that can detect tumors better than traditional technology; and Robert Rose, for an edible vaccine against human papilloma virus. “The heart of our mission is the pursuit of knowledge for the purpose of treating and curing disease, and alleviating suffering,” says C. McCollister “Mac” Evarts, CEO of the medical center. “But the fact of the matter is that we as an academic institution can’t do that alone. A discovery made in one of our labs – no matter how profound – can't help people until a company in the commercial sector takes that knowledge and uses it to produce a product, such as a drug or a medical device or a diagnostic test.”
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