Ko Harada1, Kou Hasegawa2, Fumio Otsuka2. 1. Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kitaku, Okayama, Japan. Electronic address: me422084@s.okayama-u.ac.jp. 2. Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kitaku, Okayama, Japan.