Funding for this research was provided by:
Japan Agency for Medical Research and Development (18dk0207030h0003, 18dm0107143)
Qatar Biomedical Research Institute (VR98)
Received: 4 January 2019
Accepted: 29 May 2019
First Online: 4 June 2019
Ethics approval and consent to participate
: The Ethics Committee of Showa University School of Medicine approved this study, and it was performed according to the Declaration of Helsinki. Written informed consent was obtained from all participants prior to enrolment.
: Not applicable.
: The authors declare that they have no competing interests.