Institution: | 1. Pediatric Metabolism Branch, National Institute of Arthritis, Metabolism, and Digestive Diseases, National Institutes of Health, Bethesda, Md. 20014, Bethesda, Md. USA;2. Digestive and Hereditary Diseases Branch, National Institute of Arthritis, Metabolism, and Digestive Disease, National Institutes of Health, Bethesda, Md. 20014, Bethesda, Md. USA |