1. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, Korea.
3. AIDS Research Institute, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Anesthesiology, Yonsei University College of Medicine, Seoul, Korea.
5. Department of Rehabilitation Medicine and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Korea.