1. Baylor University Medical Center at Dallas; Dallas TX USA
2. University of Utah Health Sciences Center; Salt Lake City UT USA
3. University of Colorado; Denver CO USA
4. University of California; Los Angeles CA USA
5. University of California; San Francisco CA USA
6. Columbia University College of Physicians & Surgeons; New York NY USA
7. Johns Hopkins University; Baltimore MD USA
8. Methodist Hospital; Houston TX USA