1. 2nd Department of Internal Medicine, Osaka Medical and Pharmaceutical University, Osaka, Japan
2. Endoscopy Center, Osaka Medical and Pharmaceutical University, 2-7 Daigakuchou, Takatsukishi, Osaka 569-8686, Japan
3. 2nd Department of Internal Medicine, Osaka Medical and Pharmaceutical University, 1-1 Daigakuchou, Takatsuki, Osaka 569-0801, Japan