1. From the Laboratoire RTG, (C.D., J.-M.H.), Institut Pasteur, Paris; the Cardiovascular Department, Rhône-Poulenc Rorer/Gencell (J.-M.C., F.E., P.B., D.B., N.D.), Vitry/Seine; and the Laboratoire INSERM U325 (J.C.F., G.C.), Institut Pasteur de Lille, Lille, France.