1. Department of Pathology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
2. College of Nursing, Zheng Zhou Railway Vocational and Technical College, Zhengzhou, Henan 451460, P.R. China
3. Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
4. Department of Neurology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China