1. Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
2. Department of Gastroenterology, Matsushita Memorial Hospital, 5-55 Sotojima-cho, Moriguchi city, Osaka 570-8540, Japan
3. Department of Pathology, Matsushita Memorial Hospital, 5-55 Sotojima-cho, Moriguchi, Osaka 570-8540, Japan