1. Department of Hygiene, Faculty of Sport and Physical Education, University of Nis, Čarnojevića street 10 a 18000 Nis, Serbia.
2. Institute of Biochemistry, Medical Faculty, University of Nis, Serbia
3. Clinic of Pediatrics, Clinical Center, Nis, Serbia
4. Institute of Pathology, Medical Faculty, University of Nis, Serbia
5. Institute of Hygiene, Medical Faculty, University of Nis, Serbia
6. Institute of Transfusiology, Nis, Serbia
7. Department of Sport Medicine, Faculty of Sport and Physical Education, University of Nis, Serbia