1. Departments of Medical Research, Taichung Veterans General Hospital, Taichung 40705, Taiwan
2. Departments of Otolaryngology, Taichung Veterans General Hospital, Taichung 40705, Taiwan
3. School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan
4. School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
5. Department of Post-Baccalaureate Medicine, College of Medicine, National Chung-Hsing University, Taichung 40227, Taiwan