1. Department of Cytology, Faculty of Biology, University of Warsaw, Warsaw, Poland.
2. Department of Neurology and Neurosurgery, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
3. Spine Surgery Department, Institute of Mother and Child, Warsaw, Poland.
4. Department of Neurosurgery, Children's Memorial Health Institute, Warsaw, Poland.
5. Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
6. Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland.