1. From the Department of Surgery (J.A.D., A.O., D.D.M., S.K.W., P.K.H., T.W.W.), Section of Vascular Surgery, Conrad Jobst Vascular Research Laboratories, and Unit for Laboratory Animal Medicine (D.D.M.), University of Michigan, Ann Arbor, MI; Department of Medicine (N.M.), Division of Hematology/Oncology, University of North Carolina, Chapel Hill, NC.