1. Medical School of Jishou University, Jishou, Hunan 416000, P.R. China
2. Department of Pathology, First Affiliated Hospital of Jishou University, Jishou, Hunan 416000, P.R. China
3. Department of Microbiology and immunology, Medical school of Jishou University, Jishou, Hunan 416000, P.R. China