Text and Data Mining valid from 2019-06-13
Received: 9 April 2019
Accepted: 5 June 2019
First Online: 13 June 2019
Compliance with ethical standards
: Yoshiko Ariji, Yoshihiko Sugita, Toru Nagao, Atsushi Nakayama, Motoki Fukuda, Yoshitaka Kise, Michihito Nozawa, Masako Nishiyama, Akitoshi Katumata and Eiichiro Ariji declare that they have no conflict of interest.
: 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.
: This article does not contain any studies with animal subjects performed by any of the authors.