1. From the Cardiology Division and Cardiovascular Research Center (D.N.A., F.N., P.L.H.), Stroke and Neurovascular Regulation Laboratory, Department of Radiology (Y.G.-Ö., C.A., M.A.M.), and Athinoula A. Martinos Center (A.K.D.), Massachusetts General Hospital, Charlestown, Massachusetts; and the Institute for Environmental Medicine (J.C.M., T.K., V.R.M.) and the Department of Pharmacology (V.R.M.), University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.