广西虎纹捕鸟蛛毒诱导U251胶质瘤细胞凋亡 及Caspase-3的激活

目的:探讨虎纹捕鸟蛛毒抑制体外脑胶质瘤细胞系U251生长并诱导其凋亡,激活半胱天冬酶-3(Caspase-3)的作用。方法:将U251细胞分为3组:空白组、顺铂组、加药组(虎纹捕鸟蛛毒素浓度为37.5,50,75,100,150 mg·L-1),毒素作用24,48 h后用四甲基偶氮唑蓝(MTT)法检测细胞活性并与顺铂组、空白组做对比;流式细胞仪AnnexinV-FITC检测细胞凋亡率;Caspase-3分光光度法检测Caspase-3的相对活性。结果:虎纹捕鸟蛛毒素剂量为37.5,50,75,100,150 mg·L-1时,对U251细胞的增殖有显著性抑制作用(P<0.05或P<0.01),IC50为53.48 mg·L-1。虎纹捕鸟蛛毒素可诱导U251胶质瘤细胞凋亡并呈浓度依赖关系。在剂量为150 mg·L-1诱导48 h,细胞早期凋亡率84.1%,晚期凋亡率4.48%。用不同浓度分别处理细胞,Caspase-3活性于48 h,150 mg·L-1时达高峰,对细胞中的执行分子Caspase-3的激活速度快,活化程度为9.23,并存在剂量依赖关系和浓度依赖性的升高。结论:虎纹捕鸟蛛毒素明显抑制U251细胞生长并诱导其发生凋亡,凋亡过程中有Caspase-3的激活。     

Evaluation of serum zonulin level in prediabetic patients

BackgroundThis study aimed to investigate the relationship between lipopolysaccharide (LPS) and zonulin levels and also to show the effect of acute hyperglycemic stress induced by oral glucose tolerance testing (OGTT) on zonulin levels in pre-diabetic patients.MethodsFour groups were constituted according to the criteria of the American Diabetes Association (ADA), based on OGTT results: control group (n:40); prediabetic group (n:56), divided into two subgroups: impaired fasting glucose group (IFG) (n:36), and impaired glucose tolerance (IGT) + IFG group (n:20) and type-2 diabetes mellitus (T2DM) group (n:45).ResultsZonulin and LPS did not significantly differ between the prediabetes and control groups, but were significantly higher in the T2DM group compared to both the prediabetic and the control group (P < 0.001). After OGTT, zonulin and LPS were significantly higher in the prediabetes group compared to the control group (P < 0.01 and P < 0.05, respectively), and significantly lower in the IFG and IFG + IGT groups compared to the T2DM group (P < 0.001, P < 0.001 and P < 0.001, P < 0.001, respectively). A positive correlation was detected between fasting zonulin and 2-hour zonulin (r = 0.727, P < 0.001) and between fasting LPS (r = 0.555, P < 0.001) and 2-hour LPS (r = 0.567, P < 0.001) in the prediabetic group. Increased zonulin and LPS levels and the positive correlation between these levels during the prediabetic period although non significant suggests onset of intestinal permeability.ConclusionsDuring acute hyperglycemia in prediabetic patients, up-regulation of zonulin and LPS may affect intestinal function. The intestines may play a key role in up-regulation of glucose and the pathogenesis of diabetes.     

腺病毒介导的IL-24基因对胶质瘤细胞系U251拓扑异构酶Ⅱα及Caspase-3表达的影响

目的探讨腺病毒介导的IL-24基因(Ad5F35-hIL-24)对胶质瘤细胞系U251拓扑异构酶Ⅱα(topoⅡα)及Caspase-3表达的影响。方法应用腺病毒载体将IL-24基因转染U251细胞后,采用四甲基偶氮唑盐(MTT)方法观察Ad5F35-hIL-24对U251细胞的抑制作用;Hoechst33258荧光染色,以及流式细胞术测定细胞凋亡;应用免疫组织化学方法检测topoⅡα表达;免疫印迹法检测topoⅡα和Caspase-3蛋白质表达变化;Transwell实验观察Ad5F35-hIL-24对U251细胞侵袭力的影响。结果与对照组相比,Ad5F35-hIL-24对胶质瘤细胞有明显抑制作用,能显著诱导细胞凋亡,且呈浓度依赖性;免疫组织化学法显示,Ad5F35-hIL-24能明显抑制topoⅡα表达;免疫印迹检测表明,topoⅡα表达明显降低,而Caspase-3蛋白的表达水平增加;Transwell实验表明,Ad5F35-hIL-24能明显降低U251细胞的侵袭能力。结论外源性IL-24基因能显著抑制胶质瘤细胞增殖,诱导细胞凋亡;topoⅡα及Caspase-3是其重要的作用靶点。该结果对于IL-24基因用于临床治疗胶质瘤有一定参考意义。     

N400 as an index of uncontrolled categorization processing in brand extension

Chrysotoxine is a naturally occurring bibenzyl compound found in medicinal Dendrobium species. We previously reported that chrysotoxine structure-specifically suppressed 6-hydroxydopamine (6-OHDA)-induced dopaminergic cell death. Whether chrysotoxine and other structurally similar bibenzyl compounds could also inhibit the neurotoxicity of 1-methyl-4-phenyl pyridinium (MPP(+)) and rotenone has not been investigated. We showed herein that chrysotoxine inhibited MPP(+), but not rotenone, induced dopaminergic cell death in SH-SY5Y cells. The overproduction of reactive oxygen species (ROS), mitochondrial dysfunction as indexed by the decrease in membrane potential, increase in calcium concentration and NF-κB activation triggered by MPP(+) were blocked by chrysotoxine pretreatment. The imbalance between the pro-apoptotic signals (Bax, caspase-3, ERK and p38 MAPK) and the pro-survival signals (Akt/PI3K/GSK-3β) induced by MPP(+) was partially or totally rectified by chrysotoxine. The results indicated that ROS inhibition, mitochondria protection, NF-κB modulation and regulation of multiple signals determining cell survival and cell death were involved in the protective effects of chrysotoxine against MPP(+) toxicity in SH-SY5Y cells. Given the different toxic profiles of 6-OHDA and MPP(+) as compared to rotenone, our results also indicated that DAT inhibition may partially account for the neuroprotective effects of chrysotoxine.     

SIVmac251感染中国恒河猴外周血免疫学及病毒学指标动态变化

目的 观察中国恒河猴感染猴免疫缺陷病毒(simian immunodeficiency virus,SIV)后病毒学和免疫学基本指标的变化规律,探讨中国恒河猴用于艾滋病模型时外周血白细胞(WBC)和CD4+T细胞比例的标准.方法 以SIVmac251感染36只中国恒河猴,于感染前1天及感染后1～8周每周及感染后第10周分别采集外周静脉血,检测血常规、外周血淋巴细胞亚群和病毒载量.结果 除WBC计数变化不显著外,其余检测指标均在感染后第1、2周时变化最为剧烈;WBC计数在(4～10)×106个/ml之间结合外周血CD4'T细胞比例高于25％的可作为艾滋病模型的选猴标准.结论 为应用中国恒河猴进行艾滋病研究提供了有益的信息.     

甲氟喹对胶质瘤细胞的放射增敏作用

目的:研究甲氟喹对胶质瘤细胞的放射增敏作用,并对其机制进行初步探索。方法:取指数生长期的胶质瘤U251细胞,采用CCK-8检测法研究甲氟喹作用后U251细胞的存活率;细胞克隆形成实验评估甲氟喹对U251细胞的放射增敏效果;流式细胞技术检测甲氟喹联合X射线作用后U251细胞的活性氧水平和细胞凋亡率,探索联合作用下U251细胞的死亡机制。结果:甲氟喹对胶质瘤细胞具有良好的放射增敏效果,其对U251细胞的最大放射增敏比为1.64。X射线联合甲氟喹作用于U251细胞后,细胞的凋亡水平增加,活性氧水平增加,活性氧抑制剂谷胱甘肽能抑制X射线联合甲氟喹作用诱导的U251细胞凋亡。结论:甲氟喹对U251细胞有放射增敏作用,其作用机制可能为通过增加细胞活性氧水平、诱导细胞凋亡导致放射敏感性增加。     

Association of IL8 -251A/T, IL12B -1188A/C and TNF-α -238A/G polymorphisms with Tourette syndrome in a family-based association study in a Chinese Han population

An earlier study indicated a possible relationship between Tourette syndrome (TS) and the cytokines. To explore this further, we analyzed the association of the polymorphisms, IL8 -251A/T, IL12B -1188A/C and TNF-α -238A/G, in the IL8, IL12B and TNF-α cytokine genes with TS in a Chinese Han population. A total of 108 patients diagnosed with TS and their parents were recruited for the study. The genetic contributions of the IL8 -251A/T, IL12B -1188A/C, and TNF-α -238A/G polymorphisms were evaluated using polymerase chain reaction and restriction enzyme digestion (PCR-RFLP) and haplotype relative risk (HRR) and transmission disequilibrium test (TDT) statistics. Our results revealed no significant associations between the IL8 -251A/T, IL12B -1188A/C and TNF-α -238A/G polymorphisms and TS (for IL8 -251A/T, TDT=0.418, df=1, P=0.518; HRR=2.17, X(2)=3.000, P=0.083, 95%CI: 0.900-5.230; for IL12B -1188A/C, TDT=1.131, df=1, P=0.288; HRR=1.27, X(2)=0.35, P=0.549, 95%CI: 0.580-2.790; for TNF-α -238A/G, TDT=2.793, df=1, P=0.095; HRR=0.27, X(2)=2.90, P=0.089, 95%CI: 0.061-1.217). This result was confirmed using haplotype-based haplotype relative risk (HHRR) which allows the two alleles in each genotype to be considered separately. Our data suggests that the IL-8 -251A/T, IL-12B -1188A/C and TNF-α -238A/G polymorphisms may not be associated with susceptibility to TS in the Chinese Han population studied. However, these results need to be replicated using larger datasets collected from different populations.     

L’ingénierie cutanée pour le traitement des brûlures graves

Severe burned patients need definitive and efficient wound coverage. Outcome of massive burns has been improved by using cultured epithelial autografts (CEA). Despite fragility, percentages of success take, cost of treatment and long-term tendency to contracture, this surgical technique has been developed in few burn centres. First improvements were to combine CEA and dermis-like substitute. Cultured skin substitutes provide earlier skin closure and satisfying functional result. These methods have been used successfully in massive burns. Second improvement was to allow skin regeneration by using epidermal stem cells. Stem cells have capacity to differentiate into keratinocytes, to promote wound repair and to regenerate skin appendages. Human mesenchymal stem cells contribute to wound healing and were evaluated in cutaneous radiation syndrome. Skin regeneration and tissue engineering methods remain a complex challenge and offer the possibility of new treatment for injured and burned patients.