1. University of Colorado at Denver and Health Sciences Center (L.A.K.), Denver, Colorado 80217
2. University of California, San Francisco (P.B., M.G.S., C.G.), San Francisco, California 94121
3. St. Luke’s-Roosevelt Hospital Center (D.P.K.), New York, New York 10025
4. Merck Research Laboratories (S.B.H.), Rahway, NJ 07065
5. University of Alabama at Birmingham (C.E.L.), Birmingham, Alabama 35294
6. Veterans Affairs Medical Center (M.G.S., R.S., C.G.), San Francisco, California 94121