1. The Orthopaedic Hospital University of Southern California, Los Angeles, California, USA
2. The George Washington University Medical Center, Washington D.C., USA
3. The University of California, San Diego, California, USA
4. The Blood Center of Southeastern Wisconsin, Milwaukee, Wisconsin, USA
5. The Children’s Hospital of Michigan, Wayne State University, Detroit, Michigan
6. The University of Colorado Health Sciences Center, Denver, Colorado,USA
7. The University of North Carolina Hospitals, Chapel Hill, North Carolina, USA
8. The University of Connecticut Health Center, Farmington, Connecticut, USA