1. Fourth Department of Internal Medicine, and
2. Division of Gastroenterology and Hepatology, Department of Medicine, Postgraduate School of Medicine, Kyoto University, Kyoto 606
3. Second and
4. Department of Internal Medicine, National Cancer Center Hospital, Tokyo 104
5. Second Department of Internal Medicine, Shimane University School of Medicine, Shimane 693, Japan
6. Hyogo Gastroenterology Study Group, Kobe University School
of Medicine, Kobe 650