1. From the Department of Physiology (Z.B., G.K., A.K.), New York Medical College, Valhalla, NY; the La Jolla Bioengineering Institute (J.A.F., J.-C.Y., C.R.W.), La Jolla, Calif; and the Department of Pathophysiology (Z.B., A.K.), Semmelweis University, Budapest, Hungary.