1. Center for Tissue Engineering and Stem Cell Research, Guizhou Medical University, Guiyang, Guizhou 561113, P.R. China
2. Clinical Medicine School, Guizhou Medical University, Guiyang, Guizhou 561113, P.R. China
3. Department of Pediatrics, Anshun People's Hospital, Anshun, Guizhou 561000, P.R. China
4. School of Natural Science, University of Texas at Austin, Austin, TX 78712, USA
5. Department of Human Anatomy, School of Basic Medicine, Guizhou Medical University, Guiyang, Guizhou 561113, P.R. China
6. Department of Surgery, Clinical Medical College, Guizhou Medical University, Guiyang, Guizhou 561113, P.R. China