1. Division of Gastroenterology, Department of Internal Medicine; Nippon Medical School Chiba Hokusoh Hospital; Chiba Japan
2. Core Research Facilities for Basic Science, Research Center for Medical Sciences; Jikei University School of Medicine; Tokyo Japan
3. Division of Gastroenterology and Hepatology; Otakanomori Hospital; Chiba Japan
4. Division of Gastroenterology and Hepatology; Jikei University School of Medicine Katsusika Medical Center; Tokyo Japan
5. Division of Gastroenterology; Machida Municipal Hospital; Tokyo Japan
6. Division of Gastroenterology and Hepatology, Department of Internal Medicine; Nippon Medical School; Tokyo Japan