Department of Infectious;
Respiratory;
and Digestive Medicine;
Graduate School of Medicine;
University of the Ryukyus;
Nishihara;
Okinawa 903-0215;
Japan;
Department of Endoscopy;
Graduate School of Medicine;
University of the Ryukyus;
207 Uehara;
Nishihara;
Okinawa 903-0215;
Japan;