1. Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica, Republic of Serbia.
2. Medical Faculty Novi Sad, University of Novi Sad, Novi Sad, Republic of Serbia.
3. General Hospital Sremska Mitrovica, Sremska Mitrovica, Republic of Serbia.
Submitted: 26 January 2017.
Accepted: 14 April 2017.
Study carried out at the Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica, Republic of Serbia.
Correspondence to:
Ivan Kopitovic. Institute for Pulmonary Diseases of Vojvodina, Put doktora Goldmana 4, 21204, Sremska Kamenica, Republic of Serbia.
Tel./Fax: 38 121 4805175. E-mail: ikopitovic@gmail.com or ivan.kopitovic@mf.uns.ac.rs
Financial support: This study received financial support from the Provincial Secretariat for Science and Technological Development, Autonomous Province of Vojvodina, Republic of Serbia (Project no. 114-451-718/2015-02).