1. Department of Internal Medicine, Division of Nephrology, St. Louis University, St. Louis, MO, U.S.A.
2. Hemotology-Oncology Division, University of Pennsylvania, Philadelphia, PA 19104, U.S.A.
3. E.I. Du Pont Merck Pharmaceutical Co., P.O. Box 80400, Wilmington, DE 19880, U.S.A.
4. Department of Dermatology, University of Michigan, Ann Arbor, Ml, U.S.A.