1. National Institute of Diabetes and Digestive and Kidney Diseases, Diabetes, Endocrine, and Obesity Branch, National Institutes of Health, Bethesda, Maryland.
2. National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
3. National Institutes of Child Health Development, National Institutes of Health, Bethesda, Maryland.
4. Clinical Center, National Institutes of Health, Bethesda, Maryland.
5. Division of Endocrinology and Metabolism, Virginia Commonwealth University, Richmond, Virginia.