1. Division of Otolaryngology, Tohoku Medical and Pharmaceutical University Hospital, Sendai, Japan
2. Department of Otolaryngology - Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
3. Department of Otolaryngology, Iwate Medical University, Morioka, Japan
4. Division of Medical Biochemistry, Department of Biomolecular Sciences, Saga Medical School, Saga, Japan
5. Department of Otolaryngology, Gifu University Graduate School of Medicine, Gifu, Japan
6. Technical Services Division, Tohoku Medical and Pharmaceutical University, Sendai, Japan
7. Division of Pathology, Tohoku Medical and Pharmaceutical University, Sendai, Japan