1. Department of Medicine, University of Washington (D.D., G.J.T.), Seattle, Washington 98195
2. Department of Medicine and Physiology, University of Alberta (T.J.K.), Edmonton, Alberta, Canada AB T6G 252
3. Department of Veterans Affairs Puget Sound Health Care System (G.J.T.), Seattle, Washington 98195
4. Department of Nutrition, University of California (P.J.H.), Davis, California 95616