1. Department of Medical Biochemistry, Faculty of Pharmacy , Medical University of Plovdiv , Plovdiv , Bulgaria
2. Department of Medical Microbiology and Immunology “Prof. Dr. Elissay Yanev”, Faculty of Pharmacy , Medical University of Plovdiv , Plovdiv , Bulgaria
3. Research institute at Medical University of Plovdiv , Plovdiv , Bulgaria
4. Department of Physiology, Faculty of Medicine , Medical University of Plovdiv , Plovdiv , Bulgaria