Conflict of interest

Dr. Kazuaki Tanabe has received lecture fees from Otsuka Pharmaceutical Co, Ltd. Drs. Yuka Kawanami, Kazuto Yamaguchi, Seita Yamasaki, Yuzo Kagawa, Hirotomo Sato, Nobuhide Watanabe, Akihiro Endo, Hiroyuki Yoshitomi declare that they have no conflict of interests.

Human rights statements and informed consent

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. Informed consent was obtained from the patient for being included in the study.