1. Institute of Neurobiochemistry, University of Witten/Herdecke, 58448 Witten, Germany.
2. Department of Periodontology, Faculty of Dental Medicine, University of Witten/Herdecke, 58448 Witten, Germany.
3. Research and Development Department, Miltenyi Biotec GmbH, D-51429 Bergisch Gladbach, Germany.
4. Department of Physiology and Pathophysiology, Faculty of Medicine, University of Witten/Herdecke, 58448 Witten, Germany.