1. Medical College of Pennsylvania and Hahnemann University, Philadelphia, Pennsylvania
2. Duke University Medical Center, Durham, North Carolina
3. University of Alabama, Birmingham, Alabama
4. University of Miami School of Medicine, Miami, Florida
5. Medlantic Research Center, Washington, DC
6. University of Texas Medical Branch at Galveston, Galveston, Texas
7. University of Cincinatti, Cincinatti, Ohio
8. University of Washington, Seattle, Washington.