1. Department of Internal Medicine, Gil Medical Center, Gachon University School of Medicine, Incheon, Korea.
2. Department of Laboratory Medicine, Gil Medical Center, Gachon University School of Medicine, Incheon, Korea.
3. Department of Neurosurgery, Gil Medical Center, Gachon University School of Medicine, Incheon, Korea.
4. Department of Physiology, Gil Medical Center, Gachon University School of Medicine, Incheon, Korea.