Funding for this research was provided by:
the Japanese Health Labour Sciences Research Grant (038)
Text and Data Mining valid from 2018-03-20
Received: 8 February 2018
Accepted: 12 March 2018
First Online: 20 March 2018
Ethics approval and consent to participate
: The current retrospective study was approved by the institutional review board (Tokyo Medical and Dental University). The informed consent was obtained from each patient.
: Not applicable.
: Atsushi Okawa is currently receiving a science research grant (038) from the Japanese Health Labour. For the remaining authors, none were declared.
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