1. Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania.
2. Department of Pharmacology, University of Pennsylvania, Philadelphia, Pennsylvania.
3. Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania.
4. Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
5. Department of Clinical Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem, Israel.