1 Dept of Respiratory Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
2 Dept of Occupational Health, Tohoku University Graduate School of Medicine, Sendai, Japan.
3 Research Division for Development of Anti-Infective Agents, Institute of Development, Agieng and Cancer, Tohoku University Graduate School of Medicine, Sendai, Japan.
4 Division of Respiratory and Infection Medicine, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
5 Bioscience Medical Research Centre, Niigata University Medical and Dental Hospital, Niigata, Japan.
6 Clinical Research Centre, NHO Kinki-Chuo Chest Medical Centre, Osaka, Japan.