1. Laboratory of Clinical Immunology, University Hospital “St. Ivan Rilski”, Medical University of Sofia, 1431 Sofia, Bulgaria
2. Clinic of Neurosurgery, University Hospital “St. Ivan Rilski”, Medical University of Sofia, 1431 Sofia, Bulgaria
3. Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
4. Acibadem City Clinic, University Hospital “Tokuda”, 1407 Sofia, Bulgaria
5. Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria