1. From the Department of Respiratory Medicine, The Jikei University School of Medicine Kashiwa Hospital , 163-1 Kashiwashita , Kashiwa, Chiba 277-8567, Japan
2. Division of Respiratory Diseases, Department of Internal Medicine, The Jikei University School of Medicine , 3-19-18 Nishishimbashi , Minato-ku, Tokyo 105-8471, Japan