1. Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
2. Department of Anatomy, Histology and Embryology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
3. Department of Physiology and Pathophysiology, Faculty of Medicine, Sofia Medical University, Sofia, Bulgaria
4. Department of Clinical Laboratory & Clinical Pharmacology, Alexander Hospital, Faculty of Medicine, Sofia Medical University, Sofia, Bulgaria