1. Department of Clinical Research, Hofu Institute of Gastroenterology, 14-33 Ekiminami, Hofu 747-0801, Yamaguchi, Japan
2. Department of Gastroenterology & Hepatology, Hofu Institute of Gastroenterology, 14-33 Ekiminami, Hofu 747-0801, Yamaguchi, Japan
3. Department of Surgery, Hofu Institute of Gastroenterology, 14-33 Ekiminami, Hofu 747-0801, Yamaguchi, Japan
4. Department of Clinical Research, National Hospital Organization Kanmon Medical Center, 1-1 Sotoura, Chofu, Shimonoseki 752-8510, Yamaguchi, Japan
5. Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, 1-1-1Minamikogushi, Ube 755-8505, Yamaguchi, Japan