1. Department of Neurosurgery, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
2. Department for Immunology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
3. Center of Clinical Experimental Surgery and Translational Research, Biomedical Research Foundation of Academy of Athens, 11527 Athens, Greece
4. Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway