1. Urology Service, Department of Surgery, Walter Reed Army Medical Center, Washington, D.C., the Center for Prostate Disease Research, Uniformed Services University of the Health Sciences, Bethesda, Maryland, the Armed Forces Institute of Pathology, Washington, D.C., the Laboratory of Comparative Carcinogenesis, N.C.I., F.C.R.D.C., Frederick, Maryland and B.C.D.P., PRI/Dyn Corporation, Frederick, Maryland.