1. From the departments of Medicine and Pathology, University of Chicago Hospitals and Clinics, and the Franklin McLean Memorial Research Institute (operated by the University of Chicago for the U.S. Department of Energy under Contract No. EY-76-C-02–0069), Chicago, IL (address reprint requests to Dr. Golomb at the University of Chicago Hospitals, 950 E. 59th Street, Box 420, Chicago, IL 60637).