1. Department of Gastroenterology, Juntendo University School of Medicine, Japan
2. Department of Gastroenterology, Juntendo Tokyo Koto Geriatric Medical Center, Japan
3. Department of Dermatology, Juntendo Tokyo Koto Geriatric Medical Center, Japan
4. Department of Human Pathology, Juntendo Tokyo Koto Geriatric Medical Center, Japan