Open Access Macedonian Journal of Medical Sciences; Vol 3, No 4 (2015): Dec 15 (OAMJMS); 551-557 Open Access Macedonian Journal of Medical Sciences Open Access Macedonian Journal of Medical Sciences, Vol 3, Iss 4, Pp 551-557 (2015) Open Access Macedonian Journal of Medical Sciences; Vol. 3 No. 4 (2015): Dec 15 (OAMJMS); 551-557