1. Division of Infectious Diseases (V.A.T.), Massachusetts General Hospital, Boston, Massachusetts 02114
2. Program in Nutritional Metabolism (V.A.T., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114
3. Division of Endocrinology and Metabolism (T.T.B.), Johns Hopkins University, Baltimore, Maryland 21287
4. Biostatistics Center (H.L.), Massachusetts General Hospital, Boston, Massachusetts 02114