Kosuke Minaga, Tomohiro Watanabe, Ken Kamata, Masatoshi Kudo, Department of Gastroenterology and Hepatology, Kindai University Faculty of Medicine, Osaka 589-8511, Japan
Naoki Asano, Division of Gastroenterology, Tohoku University Graduate School of Medicine, Miyagi 980-8574, Japan
Author contributions: Minaga K and Watanabe T wrote the manuscript draft and prepared the figures; Kamata K, Asano N and Kudo M assisted in writing the manuscript and reviewed the final version.
Conflict-of-interest statement: None of the authors has any conflict of interests related to this manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Tomohiro Watanabe, MD, PhD, Associate Professor, Department of Gastroenterology and Hepatology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan. firstname.lastname@example.org
Telephone: +81-72-366-0221 Fax: +81-72-367-2880
Received: March 6, 2018
Peer-review started: March 6, 2018
First decision: March 29, 2018
Revised: April 3, 2018
Accepted: April 9, 2018
Article in press: April 9, 2018
Published online: April 28, 2018