1. Division of Gastroenterology, Box 356424, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, U.S.A.
2. Puget Sound Veterans Affairs Health Care System, Seattle Division, Seattle, WA, U.S.A.
3. Division of Endocrinology and Metabolism, University of Washington School of Medicine, Seattle, WA, U.S.A.