1. From the Department of Medicine (Cardiovascular Research), St Elizabeth’s Medical Center, Tufts University School of Medicine, Boston, Mass; Department of Pathology (F.O.T), University of Texas, San Antonio, Tex; Center for Learning and Memory (P.K.), Massachusetts Institute of Technology, Cambridge, Mass; and Biocompatibles UK Limited (S.W., L.K., P.W.S.), Surrey, UK.