1. Department of Internal Medicine, Sato Hospital, Nagano, Japan
2. Department of Medicine, Division of Gastroenterology and Hepatology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
3. Department of Health Promotion Medicine, Shinshu University School of Medicine, Matsumoto, Japan
4. Department of Internal Medicine, Yodakubo Hospital, Nagawa, Nagano, Japan