1. Section of Digestive Diseases, Yale School of Medicine , New Haven, CT , USA
2. Department of Chronic Disease Epidemiology, Yale School of Public Health , New Haven, CT , USA
3. Division of Gastroenterology and Hepatology, Keio University School of Medicine , Shinjuku-ku, Tokyo , Japan
4. Harvey Cushing/John Hay Whitney Medical Library, Yale School of Medicine , New Haven, CT , USA
5. Department of Pathology, Yale School of Medicine , New Haven, CT , USA
6. Gastroenterology Department, Syrian Specialty Hospital , Damascus , Syrian Arab Republic
7. CentraCare, Interventional Endoscopy Program, Saint Cloud Hospital , St. Cloud, MN , USA
8. Section of Medical Oncology, Department of Medicine, Yale Cancer Center, Yale School of Medicine , New Haven, CT , USA