First Department of Internal Medicine;
Oita University;
Oita 879-5593;
Japan;
Department of Surgery;
National Hospital Organization Oita Medical Center;
Oita 870-0263;
Japan;
Department of Pathology;
National Hospital Organization Oita Medical Center;
Oita 870-0263;
Japan;
Department of Gastroenterology and Hepatology;
National Hospital Organization Oita Medical Center;
Oita 870-0263;
Japan;