Department of Internal Medicine, Division of Pulmonology and Allergy College of Medicine, Yeungnam University, Daegu, Korea.
Address for correspondence: Kwan Ho Lee, M.D. Department of Internal Medicine, Yeungnam University Hospital 317-1, Daemyung Dong, Namgu, Daegu, 705-035, Korea. Phone: 053-620-3838, Fax: 053-654-8386, ghlee@med.yu.ac.kr