1. From the Center for Cerebrovascular Research (P.G., F.S., R.A.G., D.L., E.Y., G.-Y.Y., W.L.Y., H.S.), Department of Anesthesia and Perioperative Care and the Departments of Neurological Surgery (W.L.Y.) and Neurology (W.L.Y.), University of California, San Francisco, Calif.