Takeshi Ogura1, Atsushi Okuda2, Kazuhide Higuchi2. 1. Second Department of Internal Medicine, Osaka Medical College, 2-7 Daigakuchou, Takatsukishi, Osaka 569-8686, Japan. Electronic address: in2121@osaka-med.ac.jp. 2. Second Department of Internal Medicine, Osaka Medical College, 2-7 Daigakuchou, Takatsukishi, Osaka 569-8686, Japan.