1. Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka 812‑8582, Japan
2. Department of Medical Gastroenterology, Shimonoseki Hospital, Yamaguchi, Yamaguchi 750‑8520, Japan
3. Department of Medicine and Clinical Science, Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka 812‑8582, Japan
4. Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Iwate Medical University, Morioka, Iwate 020‑8505, Japan