1. From the Departments of Biomedical Engineering (R.E.F., B.D.G., M.A.S., B.R.B.), Microbiology (M.A.S.), and Cell Biology (M.A.S.); and Robert M Berne Cardiovascular Research Center (R.E.F., B.D.G., C.W., M.A.S., B.R.B.), University of Virginia, Charlottesville.