1. From the Central Laboratory Animal Facility (K.R., E.W.) and the Institutes of Pathology (H.-A.L., D.B., S.C.S.), Clinical Chemistry and Laboratory Medicine (M.T., K.J.L.), Medical Biometry, Epidemiology, and Informatics (M.B.), and Medical Microbiology and Hygiene (M.H., S. Bhakdi), Johannes Gutenberg University Mainz, Germany; and the Department of Biochemistry (S. Black, D.S.), Case Western Reserve University, Cleveland, Ohio.