1. Department of Molecular Gastroenterology and Hepatology Graduate School of Medical Science Kyoto Prefectural University of Medicine 465 Kajii‐cho, Kawaramachi‐Hirokoji, Kamigyo‐ku Kyoto 602‐8566 Japan
2. Department of Infectious Diseases Graduate School of Medical Science Kyoto Prefectural University of Medicine 465 Kajii‐cho, Kawaramachi‐Hirokoji, Kamigyo‐ku Kyoto 602‐8566 Japan
3. Department of Forensic Medicine Graduate School of Medical Science Kyoto Prefectural University of Medicine Kyoto 602‐8566 Japan
4. Department of Gastroenterology Nishijin Hospital Kyoto 602‐8319 Japan
5. Department of Gastroenterology Kyoto First Red Cross Hospital Kyoto 605‐0981 Japan
6. Department of Gastroenterology Aiseikai Yamashina Hospital Kyoto 607‐8086 Japan
7. Department of Pathology Kyoto First Red Cross Hospital Kyoto 605‐0981 Japan