1. a Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health , Bethesda , MD , 20892
2. d Departments of Medicine and Pharmacology , Duke University Medical Center , Durham , NC , 27710
3. c Biochemical Mechanisms Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health , Bethesda , MD , 20892
4. b Pharmacodynamics Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health , Bethesda , MD , 20892