1. Barbara Davis Center, University of Colorado HSC, Denver, Colorado
2. Department of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina
3. Department of Medicine, University of Texas HS, San Antonio, Texas
4. Department of Medicine, University of California Los Angeles, Los Angeles, California
5. Department of Physiology and Biophysics, University of Southern California, Los Angeles, California
6. Kaiser Research Center, Northern California, Division of Research, Oakland, California
7. Division of Epidemiology and Clinical Applications, National Heart, Lung, and Blood Institute, Bethesda, Maryland