1. Department of Medicine, Veterans Affairs North Texas Health Care System and the University of Texas Southwestern Medical Center at Dallas
2. Department of Clinical Sciences, University of Texas Southwestern Medical Center at Dallas
3. Center for Mineral Metabolism, University of Texas Southwestern Medical Center at Dallas
4. Department of Nuclear Medicine, Veterans Affairs North Texas Health Care System and the University of Texas Southwestern Medical Center at Dallas
5. Department of Medicine, Veterans Affairs North Texas Health Care System, Dallas
6. Department of Medicine, University of Pennsylvania, Philadelphia
7. Department of Medicine, University of Texas Southwestern Medical Center at Dallas