1. Division of Endocrinology, Department of Internal Medicine, National Institutes of Health Specialized Cooperative Center in Reproductive Research, University of Virginia School of Medicine (G.Z.), Charlottesville, Virginia 22908
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Mayo Medical and Graduate Schools of Medicine, Endocrine Research Unit, Mayo Clinic (J.D.V.), Rochester, Minnesota 55905