1. From the Division of Vascular Surgery and the Pacific Vascular Research Laboratories, Department of Surgery (R.L.R.), and the Department of Pathology and Cardiovascular Research Institute (K.H.W.), University of California, San Francisco, and the San Francisco Veterans Administration Medical Research Center (R.L.R.); and the Gladstone Institutes of Cardiovascular Disease and Neurological Disease (R.L.R., S.M.L., K.H.W.), San Francisco, California.