Supported in part by a Hatch research fund from Idaho Agricultural Experiment Station, University of Idaho (BGH145), Moscow, ID 83844, and subcontracts of the Department of Defense (contract No. DAMD17-03-1-0746); the National Institute of Neurological Disorders and Stroke, National Institutes of Health (contract No. N01-NS-0-2327); and the National Heart Lung and Blood Institute, National Intitutes of Health. The latter 3 subcontracts were provided through the Baltimore Research and Education Foundation Incorporated, 151-A, 10 N Greene St, Baltimore, MD 21201.