1. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, 2001 N. Soto Street, Los Angeles, CA 90033, USA
2. Department of Medicine, Division of Cardiology, University of California, Irvine, Irvine, CA, USA
3. Pulmonology Department, Shariati Hospital, Tehran, Iran
4. National Research Institute of Tuberculosis and Lung Disease, E19575/154 Darabad, Shaheed Bahonar Avenue, Tehran 19556, Iran
5. Pulmonology Department, Sina Hospital, Tehran, Iran