1. Department of Internal Medicine UnMed Clinic Motomachi Yokohama Kanagawa Japan
2. Department of Public Health and Environmental Medicine The Jikei University School of Medicine Tokyo Japan
3. Department of Internal Medicine Kajihara Clinic Hiratsuka Kanagawa Japan
4. Department of Internal Medicine, Division of Gastroenterology and Hepatology The Jikei University Kashiwa Hospital Chiba Japan