1. Department of Medicine Northwestern University Chicago Illinois USA
2. Department of Medicine Medical University of South Carolina Charleston South Carolina USA
3. Department of Medicine Mayo Clinic Arizona Scottsdale Arizona USA
4. Department of Medicine Virginia Commonwealth University Richmond Virginia USA
5. Department of Medicine University of California San Francisco California USA
6. Department of Medicine University of Texas Southwestern Medical Center Dallas Texas USA
7. Department of Medicine University of Washington Seattle Washington USA
8. Department of Medicine Baylor College of Medicine Houston Texas USA