1. Division of Respiratory Medicine; Mito Medical Center; University of Tsukuba; Tsukuba Ibaraki Japan
2. Division of General Medicine; Mito Medical Center; University of Tsukuba; Tsukuba Ibaraki Japan
3. Division of Pathology; Mito Medical Center; University of Tsukuba; Tsukuba Ibaraki Japan
4. Division of Surgery; Mito Medical Center; University of Tsukuba; Tsukuba Ibaraki Japan
5. Department of Pathology; Faculty of Medicine; University of Tsukuba; Tsukuba Ibaraki Japan