1. Department of Neurology, University Greifswald, Greifswald, Germany.
2. Institute for Clinical Chemistry and Laboratory Medicine, University Greifswald, Greifswald, Germany.
3. Insitute for Biochemistry, University Greifswald, Greifswald, Germany.
4. Proteome Center Rostock, University of Rostock, Rostock, Germany.