Researchers at Jefferson Medical College and Duke University have used gene therapy to help damaged heart cells regain strength and beat normally again in the laboratory. The work takes the scientists one step closer to eventual clinical trials in humans. Walter Koch, Ph.D., director of the Center for Translational Medicine of the Department of Medicine at Jefferson Medical College of Thomas Jefferson University in Philadelphia, and his colleagues at Duke used a virus to carry a gene into the heart cells of individuals who had suffered heart failure. The gene blocks the activity of an enzyme that is increased in such heart cells, in turn, enabling the cells to beat at normal strength. Dr. Koch and his co-workers at Duke University Medical Center in Durham, N.C., presented their findings this week at the American Heart Association’s Scientific Sessions 2003 in Orlando.