1. Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University – Varna, Varna, Bulgaria
2. Clinics of Nephrology, University Hospital – ‘Tzaritza Ioanna – ISUL’, Medical University – Sofia, Sofia, Bulgaria
3. Medical University – Varna, Varna, Bulgaria
4. Clinics of Nephrology, Dialysis and Transplantation, University Hospital – ‘St Marina’, Medical University – Varna, Varna, Bulgaria