1. Department of General Internal Medicine; Hiroshima University Hospital; 1-2-3 Kasumi Minami-ku Hiroshima 734-8551 Japan
2. Division of Gastroenterology and Hepatology; Toho University Omori Medical Center; Tokyo Japan
3. Department of Internal Medicine; Banbuntane Houtokukai Hospital, Fujita Health University School of Medicine; Nagoya Japan
4. Department of Community-Based Medical Educations; Nagoya City University Graduate School of Medical Sciences; Nagoya Japan
5. Department of Medicine and Clinical Oncology; Graduate School of Medicine, Chiba University; Chiba Japan
6. Saitama Medical University International Medical Center; Saitama Japan