1. Division of Gastroenterology, Department of Internal Medicine, Asahikawa Medical University, Asahikawa, Japan
2. Division of Cardiology, Nephrology, Pulmonology and Neurology, Department of Internal Medicine, Asahikawa Medical University, Asahikawa, Japan
3. Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Asahikawa, Japan.