1. Department of Gastroenterology and Hepatology, Kusunoki Hospital, Fujioka 375-0024, Japan
2. Department of Clinical Research, NHO Takasaki General Medical Center, Takasaki 370-0829, Japan
3. Department of Gastroenterology, Gunma Saiseikai Maebashi Hospital, Maebashi 371-0821, Japan
4. Department of Internal Medicine, Isesaki Municipal Hospital, Isesaki 372-0817, Japan
5. Department of Internal Medicine, Kiryu Kosei General Hospital, Kiryu 376-0224, Japan
6. Department of Gastroenterology and Hepatology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
7. Department of Gastroenterology, NHO Takasaki General Medical Center, Takasaki 370-0829, Japan