1. Renal Division, Department of Medicine, Peking University First Hospital, Beijing, P.R. China
2. Peking University Institute of Nephrology, Beijing, P.R. China
3. Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, P.R. China
4. Renal Division, Department of Medicine, Second Clinical Medical College, Guangzhou University of Traditional Chinese Medicine, Guangzhou, P.R. China
5. Laboratory of Electron Microscopy, Pathological Centre, Peking University First Hospital, Beijing, P.R. China