1. Howard University, College of Medicine, Washington, DC 20060, USA
2. Division of Cardiovascular Disease, Department of Medicine, Washington, DC 20060, USA
3. University of Michigan, Ann Arbor, MI 48109, USA
4. Harlem Hospital Center, New York, NY 10037, USA
5. Martin Luther King/Charles R. Drew University of Medicine, Los Angeles, CA 90059, USA
6. University of Utah, Salt Lake City, UT 84112, USA
7. The Cleveland Clinic Foundation, Cleveland, OH 44195, USA
8. National Institute of Health, Bethesda, MD 66420, USA