1 Center for Gastroenterology, Teine-Keijinkai Hospital, Sapporo, Japan; Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan.
2 Department of Pathology, Teine-Keijinkai Hospital, Sapporo, Japan; Department of Investigative Pathology, Tohoku University Graduate School of Medicine, Sendai, Japan.
3 Center for Gastroenterology, Teine-Keijinkai Hospital, Sapporo, Japan.