1. From the Sinai Center for Thrombosis Research (V.L.S., A.I.M.), Johns Hopkins University, Baltimore, Md; Columbia University (A.H.G.), New York, NY; Emory University (C.B.N., D.L.M), Atlanta, Ga; Queen’s University (L.T.v.Z.), Kingston, Ontario, Canada; West Virginia University (M.S.F.), Morgantown, WV; Duke Clinical Research Institute (K.R.R.K, R.M.C., C.M.O.), Durham, NC; and Pfizer, Inc (M.G., W.H.), New York, NY.