1. Department of Gastroenterology, Akita University Graduate School of Medicine, Akita, Japan
2. Kataoka Internal Medicine Clinic, Akita, Japan
3. Kudo Gastroenterology Clinic, Akita, Japan
4. Zeniya Clinic, Akita, Japan
5. Segawa Clinic, Noshiro, Japan
6. Oikawa Clinic, Akita, Japan
7. Odashima Masaru Clinic, Yokote, Japan
8. Matsugasaki Clinic, Akita, Japan
9. Kuramitsu Clinic, Akita, Japan
10. Sasahara Internal Medicine Clinic, Akita, Japan
11. Yoneyama Gastroenterology Clinic, Akita, Japan
12. Tomita Gastroenterology Clinic, Akita, Japan