1. Thomas Jefferson University, Philadelphia, Pennsylvania, USA
2. University of Lubeck, Lubeck, Germany
3. University-Hospital Mannheim, Mannheim, Germany
4. University of Pennsylvania, Philadelphia, Pennsylvania, USA
5. University of Pittsburgh, Pittsburgh, Pennsylvania, USA
6. Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
7. MedStar Washington Hospital Center, Washington, DC, USA
8. University of Alabama, Birmingham, Alabama, USA
9. University Hospital Cleveland, Cleveland, Ohio, USA
10. Technical University of Munich, Munich, Germany