1. Department of Neurosurgery, Seoul National University College of Medicine, Seoul 110-744, Korea
2. Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
3. Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
4. Department of Brain & Cognitive Sciences, College of Pharmacy, Brain Disease Research Institute, Ewha Woman's University, Seoul 120-750, Korea
5. Department of Biochemistry, Inha University School of Medicine, Incheon 402-751, Korea
6. Department of Neurosurgery, Mayo Clinic, USA
7. Department of Neurology, Seoul National University College of Medicine, Seoul 110-744, Korea
8. Department of Laboratory Medicine, Seoul National University Hospital, Seoul 110-744, Korea