Received: 29 December 2017
Accepted: 1 June 2018
First Online: 13 June 2018
: All animal experimental protocols were approved by the Institutional Animal Care and Faculty of Medicine at the University of the Ryukyus (No. 5115), and all the animal experiments were carried out in strict accordance with the Guidelines for Care and Use of Laboratory Animals of the Institutional Animal Care and Faculty of Medicine at the University of the Ryukyus. All efforts were made to minimize animal suffering.
: The authors declare that they have no competing interests.
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