1 Department of Respiratory Disease, Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital, Naka-ku, Hiroshima, Japan. Electronic address: graymzo@yahoo.co.jp.
2 Department of Respiratory Disease, Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital, Naka-ku, Hiroshima, Japan.
3 Department of Respiratory Disease, Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital, Naka-ku, Hiroshima, Japan; Ohashi Clinic, Naka-ku, Hiroshima, Japan.
4 Department of Molecular and Internal Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan.