1 Department of Respiratory Medicine, Hidaka Hospital, Gunma, Japan; Department of Respiratory Medicine, Comprehensive Cancer Center, International Medical Center, Saitama Medical University, Saitama, Japan. Electronic address: kkaira1970@yahoo.co.jp.
2 Department of Cardiovascular Medicine, Hidaka Hospital, Gunma, Japan.
3 Department of Respiratory Medicine, Hidaka Hospital, Gunma, Japan.