1. Third Department of Internal Medicine, University of Toyama, Toyama, Japan
2. Department of Gastroenterology, Teikyo University Mizonokuchi Hospital, Kawasaki, Japan
3. First Department of Internal Medicine, Gifu University, Gifu, Japan
4. Department of Gastroenterology, Gifu Prefectural Medical Center, Gifu, Japan
5. Department of Gastroenterology, Gifu Municipal Hospital, Gifu, Japan