1. From the Department of Surgery, Urology Service, Walter Reed Army Medical Center, Washington, D. C., Center for Prostate Disease Research, Rockville, Maryland, Urology Service, Wilford Hall USAF Medical Center, Lackland and Urology Service, Department of Surgery, Brooke Army Medical Center, San Antonio, Texas, Urology Service, Naval Medical Center, San Diego, California, Urology Service, Madigan Army Medical Center, Tacoma, Washington, and Urology Service, Naval Medical Center, Portsmouth, Virginia