1. Department of Gastroenterology and Hepatology; Nagoya University Graduate School of Medicine; Nagoya Japan
2. Department of Endoscopy; Nagoya University Hospital; 65 Tsuruma-cho, Showa-ku Nagoya 466-8550 Japan
3. Department of Pathology and Clinical Laboratories; Nagoya University Hospital; Nagoya Japan
4. Division of Surgical Oncology, Department of Surgery; Nagoya University Graduate School of Medicine; Nagoya 466-8550 Japan