Reversible effect of MR and ELF magnetic fields (0.5 T and 0.5 mT) on human lymphocyte activation patterns

PURPOSE: The aim of this study was to investigate the effects of magnetic fields (MF) of different intensity generated by a magnetic resonance (MR) unit (0.5 Tesla) and a double cylindrical coil (0.5 m Tesla) on human CD4(+) T cell lines. MATERIALS AND METHODS: CD4(+) T cells were exposed for two hours under isothermal conditions (37 +/- 0.5 degrees C) to the above mentioned MF; a control group was provided for each exposed sample. After exposure, the samples were analysed in the laboratory for the following endpoints: release of cytokines, expression of surface markers, cell proliferation and levels of cytosolic free-calcium. RESULTS: Exposure to MF for 2 h and subsequent in vitro stimulation in the presence of the appropriate mitogen, caused a decrease of interferon-gamma production, a decrease of cell proliferation, a decrease of expression of CD25 and a decrease of cytosolic free calcium concentration in exposed CD4(+) T cell lines. Data obtained, were statistically significant when evaluated after 24 h of in vitro culture, but were not significant, for both types of MF, when the experimental groups were analysed after prolonged in vitro culture. CONCLUSION: These results indicate that static magnetic fields (SMF) can give rise to transient biological effects on T lymphocytes and the present system is a sensitive model for understanding the effects of MF on the immune system.     

In vitro apoptosis in peripheral blood mononuclear cells induced by low-dose radiotherapy displays a discontinuous dose-dependence

Purpose: Cells undergoing apoptosis contribute to the regulation of activated mononuclear cells (Voll et al. 1997). Low-dose radiotherapy (LD-RT) is known to improve inflammatory symptoms, but the mechanism of action is still unclear. The aim of this study was to investigate the rate of apoptosis of peripheral blood mononuclear cells (PBMC) induced by LD-RT within the therapeutic dose range of anti-inflammatory RT. Materials and methods: PBMC were isolated from venous blood of ten healthy volunteers and were irradiated with single doses between 0.1 and 3.0Gy. Apoptotic nuclei were detected by flow cytometry after propidium iodide (PI) triton staining, and apoptotic cells were detected by annexin V/PI staining and cell scatter analysis. Since apoptotic cells display increased cytoplasmatic granularity and concomitant reduced cell size, they can be distinguished from viable cells in forward/side scatter (FSC/SSC) histograms. Apoptotic PBMC were further subtyped by double staining with annexin V and directly labelled monoclonal antibodies recognizing the lineage-specific surface markers CD4, CD8, and CD19, respectively. The apoptosis rate of irradiated cells was analysed in a time and dose dependent fashion and was compared to a sham-irradiated control. Results: After irradiation, a dose-dependent increase in apoptosis was observed, with a discontinuity (plateau or peak) between 0.3Gy and 0.7Gy in 9/10 donors (90%) and 59/80 samples (74%). 8/10 donors (80%) and 38/80 samples (47%) showed not only a discontinuous increase with a plateau but a relative maximum of apoptosis peaking within the dose range of 0.3Gy and up to 0.7Gy. Conclusion: LD-RT induces a relative maximum of apoptosis in PBMC in the does range between 0.3Gy and 0.7Gy. This may contribute to its anti-inflammatory effect observed clinically.     

重组干扰素-γ对哮喘患者外周血单核细胞IL-4和IL-10 mRNA表达的调节作用

目的 :研究重组干扰素 -γ对哮喘患者外周血单核细胞 (PBMC)IL - 4和IL - 10mRNA表达的调节作用。方法 :哮喘患者9例、正常人 5例的外周静脉血 ,ficoll-hypaue密度梯度离心分离PBMC ,分为 2组进行培养 ,A组加入rIFN -γ ,0 .2U·μl-1;B组为不加rIFN -γ的对照组。在 3 7℃ ,5 %CO2 培养箱中培养 48h后 ,用RT -PCR方法检测PBMCIL - 4和IL - 10mRNA表达。结果 :哮喘患者PBMCIL - 4mRNA的表达显著高于正常对照组 (P <0 .0 5 ) ,IL - 10mRNA的表达低于正常对照组 (P <0 .0 5 )。rIFN -γ作用于PBMC 48h后 ,哮喘患者PBMCIL - 4mRNA的表达显著降低 (P <0 .0 5 ) ,IL - 10mRNA的表达明显上升 (P <0 .0 5 ) ,而健康者PBMCIL - 4和IL - 10mRNA的表达均无显著改变 (P >0 .0 5 )。结论 :rIFN -γ可能通过下调哮喘患者PBMCIL- 4mRNA的表达、上调IL - 10mRNA的表达而发挥抗炎作用     

辐射诱导人细胞系CEM、外周血单个核细胞DNA修复基因hHR21~(sp)的表达研究

目的　研究辐射对人T淋巴细胞白血病细胞系 (CEM)、外周血单个核细胞的hHR2 1sp基因转录表达水平的影响及意义。方法　分别对人T淋巴细胞白血病细胞系CEM和正常人外周血单核细胞在UV或γ辐射后不同时间提取细胞总RNA ,通过RT PCR与hHR2 1sp 基因特异引物杂交 ,以 β actin为内参照放射影像密度扫描检测人T淋巴细胞白血病细胞系CEM、单核细胞DNA修复基因表达。结果　在UV 辐射、γ 辐射后早期 (3～ 6h) ,人T淋巴细胞白血病细胞系CEM和淋巴细胞hHR2 1sp基因的表达水平明显增加 ,照射后 6hhHR2 1sp基因的表达水平增加最多且UV辐射更明显 ,在晚期 (9h)降低。比较人细胞系CEM和淋巴细胞两者hHR2 1sp基因的表达水平 ,γ辐射 (3Gy)后淋巴细胞对hHR2 1sp基因表达高于人细胞系CEM ,且表达增加时间较长 ,达 9h ;而人细胞系CEM受到γ辐射后早期表达增加 ,在 6～ 9h后表达降低。结论　人T淋巴细胞白血病细胞系 (CEM)和人淋巴细胞的DNA修复基因hHR2 1sp基因在一定剂量辐射 (UV、γ辐射 )范围内其表达水平随辐射剂量增加而诱导表达水平增高 ,且对UV辐射更敏感 ;提示hHR2 1sp基因在人细胞系CEM细胞和人单核细胞在照射损伤后表达增加 ,可能是促进单核细胞损伤修复的原因之一。     

辐射诱导人细胞系CEM、外周血单个核细胞DNA修复基因hHR21sp的表达研究

目的：研究辐射对人T淋巴细胞白血病细胞系（CEM）、外周血单个核细胞的hHR21^sp基因转录表达水平的影响及意义。方法：分别对人T淋巴细胞白血病细胞系CEM和正常人外周血单核细胞在UV或γ辐射后不同时间提取细胞总RNA,通过RT－PCR与hHR21^sp基因特异引物杂交,以β-actin为内参照射像密度扫描检测人T淋巴细胞白血病细胞系CEM、单核细胞DNA修复基因表达,结果：UV－辐射、γ－辐射后早期（3－6h）, 人T淋巴细胞白血病细胞系CEM和淋巴细胞hHR21^sp基因的表达水平明显增加,照射后6hhHR21^sp基因的表达水平增加最多且UV辐射更明显,在晚期（9h)降低。比较人细胞系CEM和淋巴细胞两者hHR21^sp基因的表达水平,γ辐射（3Gy)后淋巴细胞对hHR21^sp基因表达高于人细胞系CEM,且表达增加时间较长,达9h;而人细胞系CEM受到γ辐射后早期表达增加,在6－9h后表达降低,结论：人T淋巴细胞白血病细胞系（CEM）和人淋巴细胞的DNA修复基因hHR21^sp基因在一定剂量辐射（UV、γ辐射）范围内其表达水平随辐射剂量增加而诱导表达水平增高,且对UV辐射更敏感,提示hHR21^sp基因在人细胞系CEM细胞和人单核细胞在照射损后表达增加,可能是促进单核细胞损伤修复的原因之一。     

强直性脊柱炎患者外周血单个核细胞干扰素诱导蛋白10及Th1/Th2型细胞因子的表达

目的　探讨干扰素诱导蛋白 10 (IP 10 )在强直性脊柱炎 (AS)发病中的作用。方法　收集肝素抗凝的AS患者的外周全血 ,梯度离心得到外周血单个核细胞(PBMC) ,应用半定量RT PCR法测定IP 10、IFN γ和IL 4mRNA表达水平。结果　AS患者PBMC中IP 10、IFN γ和IL 4mRNA表达水平均较健康对照组高(P <0 0 1) ,同时IFN γ/IL 4值也较对照组高 (P <0 0 5 )。IFN γ和IL 4mRNA表达水平与C 反应蛋白呈负相关 ,IP 10mRNA表达水平与IFN γ、IL 4mRNA和IFN γ/IL 4值均呈正相关。结论　AS患者PBMC表达的细胞因子以Th1型为主 ,IP 10表达升高 ,IP 10可能通过促进Th1型细胞向炎症部位的归巢来参与AS的发病     

α-粒子诱发BEP2D细胞癌变系的DNA断裂重接修复缺陷与XRCCs修复基因mRNA表达研究

目的 研究α粒子诱发人支气管上皮细胞(BEP2D)癌变细胞系BERP35T-1和BERP35T-4的DNA断裂损伤修复能力,分析其DNA断裂修复基因XRCCs系列的mRNA表达。方法 脉冲电场凝胶电泳法检测DNA双链断裂,RT-PCR分析DNA修复基因的mRNA表达。结果 恶性转化细胞系BERP35T-1和BERP35T-4受0～150Gyγ射线照射后修复4h的DNA断裂残留损伤显着高于亲本BEP2D细胞,mRNA表达分析显示修复基因XRCC2、XRCC3和Ku80(XRCC5)表达下调2.5～6.5倍,而BERP35T4细胞中DNAPKcs(XRCC7)表达上调2.4倍。结论 α粒子诱发恶性转化细胞系的DNA链断裂修复机理缺陷,其中部分原因是DNA修复基因的表达抑制。DNA修复缺陷将导致细胞基因组不稳定性,α粒子诱发细胞恶性转化机理可能与此相关。