Article History
Received: 25 July 2018
Accepted: 31 December 2018
First Online: 7 January 2019
Compliance with Ethical Standards
:
: Mari Nakao declares that she has no conflict of interest. Fumiko Oshima declares that she has no conflict of interest. Yutaka Maeno declares that he has no conflict of interest. Shinichi Izumi declares that he has no conflict of interest.
: This study was approved by the Institutional Review Board of Tohoku University School of Medicine (ID 2016-1-857) with the 1964 Helsinki Declaration and its later amendments. This article does not contain any studies with human participants, materials acquired from human body parts, or animals performed by any of the authors. Information including ethical standards and contact information on this study was disclosed on the web site of each facility that participated in this study.