1. Endoscopy, Robert Wood Johnson University Hospital, New Brunswick, New Jersey, USA;
2. La Mesa, La Mesa, California, USA;
3. Pune Hospital, Pune Hospital, Pune, India;
4. West Virginia University, Morgantown, West Virginia, USA;
5. Methodist Dallas Medical Center, Dallas, Texas, USA;
6. Instituto Ecuatoriano de Enfermedades Digestivas, Guayaquil, Ecuador;
7. Milan Hospital, Milan, Italy;
8. Hospital das Clinicas da FMRPUSP, Sao Paulo, Brazil.
9. Minneapolis VA Health Care System, Minneapolis, Minnesota, USA;