Objective To observe the effects of mesenchymal stem cells (MSCS) transplantation on the brain-derived neurotrophic factors (BDNF) after the spinal cord injury (SCI) of rats, and investigate the mechanism of repairing the SCI by MSCS transplantation.Methods Mesenchymal stem cells were cultured from the thighbone of adult SD rats and identified by immunoctochemistry.Seven days after the operation of spinal cord injury, the mesenchymal stem cells were transplanted into the injured spinal cord site.Sixty adult SD rats were random divided into three groups: Spinal cord injury cured with transplants of mesenchymal stem cells to the injured spinal cord site ( group A), spinal cord injury received PBS solution( group B) and control group ( group C).The expression of brain - derived neurotrophic factors of the lesion and neighbor areas were examined by immunohistochemistry, The mechanism of repairing the lesion and neighbor areas were examined by immunohistochemistry, and the mechanisms of repairing the spinal cord injury after mesenchymal stem cells transplantation were investigated.Results Mesenchymal stem cells began to grow after 24 hours of inoculation and proliferate 72 hours later.The proliferate the proliferous cyclewas 4 ～6 days, it declined on the 10th era.Mesenchymal stem cells turned to flat, and the mesenchymal stem cells could maintain the ability of proliferation if bFGF was added.Compared with group B, transplantation of mesenchymal stem cells enhanced more expression of brain-derived neurotrophic factors in group A ( 14 d :0.31 ± 0.03 vs 0.25 ± 0.04, P ＜ 0.01 ).Conclusion Mesenchymal stem cells in transplantation group showed a continued high level of brain-derived neurotrophic factors, which may be one of the mechanisms of repairing the spinal cord injury by mesenchymal stem cells transplantation.

Objective To investigate the effect of interferon-α (IFN-α) on expression of major histocompatibility complex (MHC) class I chain-related protein A (MICA) in the malignant hematopoietic cell lines.Methods The myeloid leukemia cell lines K562 and B-cell lymphoma cell line Raji were treated with IFN-α.The expression of MICA was measured by RT-PCR and immunohistochemical staining at mRNA and protein level.The cytotoxicity of human NK cells to the IFN-α treated malignant hematopoietic cells was detected by MTT method.Results After being treated with 1000 U/ml IFN-α,up-regulation of MICA mRNA in Raji and K562 cells were respectively found in 24 h and 48 hours (t =17.016,P ＜0.05; t =5.616,P ＜0.05).After being treated with IFN-α 72 hours,up-regulation of MICA mRNA in K562 and Raji were found at the dose of 500 U/ml and 1000 U/ml dose (t =6.622,P ＜0.05; t =9.071,P ＜0.05).The mRNA and protein expression of MICA were up-regulated by IFN-o in the two malignant hematopoietic cells in a time and dosedependent manner.After being treated with 1000 U/ml IFN-o for 72 hours,the susceptibility of the two malignant hematopoietic cells to NK cytolysis was significantly increased (t =20.016,P ＜0.05; t =7.969,P ＜0.05).Moreover,the up-regulated susceptibility can be blocked by anti-MICA antibody.Conclusion IFN-α can up-regulate the MICA expression in the malignant hematopoietic cell lines and thereby enhance the susceptibility to cytolysis of NK cells.

Objective To determine counts of T lymphocyte sub-populations in malignant and tuberculous pleural effusion or ascites and evaluate its significance in difierential diagnosis.Methods T lymphocyte sub-populations in pleural effusion or ascites and peripheral blood were determined in 30 patients with tuberculosis and 31 patients with cancer by flow cytometry.Concentrations of cytokines Th1 and Th2,γ-interferon(IFN-γ),interleukin-12(IL-12)and IL-4 in pleural effusion or ascites were measured by enzyme-linked immunosorbent assay(ELISA).Results Compared to that in peripheral blood,percentage of CD3+ and CD4+ T-celI counts were all higher in both malignant and tuberculous pleural effusion or ascites [(73±6)%and(67±20)%vs.(51±19)%and(48±14)%,P＜0.05].Although CD3+T-cells count was higher in tuberculous pleural effusions or ascites,no difference in ratio of CD3+ and CD4+/CD3+ and CD8+ T-cell counts was found between malignant and tuberculous pleural effusions or ascites.However,ratios of IFN-γ and IL-12 to IL-4 were higher in tuberculous pleural effusion or ascites(54±24 and 82±19vs.8±6 and 19±10,t=10.34 and 16.28,respectively,P＜0.01).Conclusions CD3+ and CD4+ Tcells can be aggregated in both malignant and tuberculous pleural effusions or ascites,80 nature (tuberculosis or malignancy)of pleural effusion or ascites can not be differentiated by CD4+ and/or CD8+ T-cell counts only,and determination of cytokines Th1 and Th2 can help their differentiation.

Objective To study the relationship between the dynamic change of free DNA in cerebrospinal fluid (CSF)and the tissue injury in the patients with hypertensive intracerebral hemorrhage.Methods 54 cases of hypertensive intracerebral hemor-rhage were divided into 3 groups according to the glasgow coma scale(including 17 mild cases,21 moderate cases and 16 severe ca-ses).2 mL of CSF was collected for extracting free DNA on 1,3,7,15 d after stroke onset.The free DNA level was measured by the fluorescent real-time PCR.Results The free DNA level in the severe group was significantly higher than that in the mild and mod-erate groups.The free DNA level in the abnormal intracranial pressure group was higher than that in the normal intracranial pres-sure group;the intracranial infection group was higher than the non-infection group.Conclusion The free DNA level has certain value for diagnosing the craniocerebral injury in hypertensive intracerebral hemorrhage and is conducive to monitor the occurrence of postoperative complications.