1. Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C.
2. School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan, R.O.C.
3. Division of Pulmonary and Critical Care Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C.
4. Division of Thoracic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan, R.O.C.