三氧化二砷与维甲酸联合作用在NB4,MR2细胞系中的体外研究

目的：观察三氧化二砷(As2O3)和全反式维甲酸(ATRA)联合作用对NB4，MR2不同亚型急性早幼粒白血病细胞株，诱导分化、增殖、凋亡的影响。方法:以NB4，MR2为体外模型，利用细胞生长曲线、台盼蓝拒染法、MTT法、NBT、细胞形态Wrigh‘s-Gimesa染色，观察细胞增殖、分化、凋亡的相互作用。结果：NB4细胞株：0．5μmol/L As2O3与10^-6mol/L ATRA对细胞增殖、分化、凋亡呈现拮抗，而0．5μmol/L As2O3与(10^-7--10^-8mol/L)ATRA呈现协同；MR2细胞株：0．5μmol/L As2O3与10^-6mol/L ATRA对细胞增殖、分化、凋亡呈现协同。结论：As2O3与全反式维甲酸协同效应呈现不同细胞、剂量的特异性，MR2细胞株协同效应明显强于NB4细胞株。     

心肌缺血再灌注损伤时细胞核被膜钙泵活性特征的研究

目的　研究心肌缺血再灌注损伤时Ca2 + 、ATP、ADP和AMP对细胞核被膜钙泵 (Ca2 + ATPase)活性的调节。方法　采用大鼠心肌缺血再灌注模型 ,密度梯度分离纯化细胞核 ,定磷法测定Ca2 + ATPase活性。结果　与正常大鼠相比 ,缺血再灌注损伤动物血浆MDA和FFA显著升高 (P <0 0 1) ;细胞核Ca2 + ATPase活性下降 ,对Ca2 + 亲和力降低 ;ADP、AMP对核Ca2 + ATPase活性的影响明显减弱 ;ATP对Ca2 + ATPase的作用在 [ATP]小于 1 0mmol L时 ,与正常细胞Ca2 + AT Pase活性无显著差异 ,浓度增至 2 0mmol L时 ,活性低于正常细胞 ,ATP浓度继续增加 ,核Ca2 + ATPase活性快速增加。结论　心肌缺血再灌注损伤时Ca2 + 、ATP、ADP、AMP对心肌细胞核Ca2 + ATPase活性的影响发生了明显改变 ,其病理生理意义值得进一步探讨。     

Handling of asymmetrical dimethylarginine and symmetrical dimethylarginine by the rat kidney under basal conditions and during endotoxaemia.

BACKGROUND: Asymmetrical dimethylarginine (ADMA) is capable of inhibiting nitric oxide synthase enzymes, whereas symmetrical dimethylarginine (SDMA) competes with arginine transport. The potential role of inflammation in the metabolism of ADMA has been elucidated in an in vitro model using tumour necrosis factor-alpha, resulting in a decreased activity of the ADMA-degrading enzyme dimethylarginine dimethylaminohydrolase (DDAH). The kidney probably plays a crucial role in the metabolism of ADMA by both urinary excretion and degradation by DDAH. We aimed to further elucidate the role of the kidney in a rat model under basal conditions and during endotoxaemia. METHODS: Twenty-five male Wistar rats weighing 275-300 g were used for this study. The combination of arteriovenous concentration differences and kidney blood flow allowed calculation of net organ fluxes. Blood flow was measured using radiolabelled microspheres according to the reference sample method. Concentrations of ADMA, SDMA and arginine were measured by high-performance liquid chromatography. RESULTS: The kidney showed net uptake of both ADMA and SDMA and fractional extraction rates were 35% and 31%, respectively. Endotoxaemia resulted in a lower systemic ADMA concentration (P = 0.01), which was not explained by an increased net renal uptake. Systemic SDMA concentrations increased during endotoxaemia (P = 0.007), which was accompanied by increased creatinine concentrations. CONCLUSIONS: The rat kidney plays a crucial role in the regulation of concentrations of dimethylarginines, as both ADMA and SDMA were eliminated from the systemic circulation in substantial amounts. Furthermore, evidence for the role of endotoxaemia in the metabolism of dimethylarginines was obtained as plasma levels of ADMA were significantly lower in endotoxaemic rats.     

胃癌组织中Fas、FasL和P27表达的临床研究

目的 研究Fas、FasL、P27在胃癌组织中的表达，并探讨其生物学意义。方法 采用免疫组化SP法检测50例胃癌组织、癌旁交界组织、距肿瘤边缘5cm组织及10例正常胃粘膜中Fas、FasL的表达，并对正常胃粘膜和肿瘤组织中P27的表达进行检测。结果 胃癌组织、癌旁交界组织的Fas表达和P27的表达明显低于正常组织(P＜0．01)，而FasL表达明显高于正常组织。胃癌不同TNM分期、不同分化程度、淋巴结有无转移的Fas、FasL表达无显著性差异(P＞0．05)，而P27表达有显著性差异(P＜0．01，P＜0．05)。结论 Fas、FasL表达与胃癌形成有关，与胃癌进展无关，Fas/FasL系统可能在胃癌发生发展过程的免疫逃避中起重要作用；P27可能是一个预测胃癌预后的重要因素。     

胰岛素泵治疗与2型糖尿病第一时相分泌的研究进展

随着对糖尿病机理研究的深入，发现胰岛β细胞第一时相分泌，对糖尿病的发生、发展有重要影响，新诊断2型糖尿病患者早期予胰岛素泵治疗，模拟生理性胰岛素分泌方式，可改善第一时相分泌，促进胰岛β细胞功能的修复，利于糖尿病的治疗及预后。     

人脑胶质瘤中P53和VEGF 的表达及意义

目的 探讨胶质瘤组织中血管内皮生长因子(VEGF)和P53蛋白的表达及其临床意义。方法 应用免疫组织化学技术对50例胶质瘤组织进行P53、VEGF表达的检测。结果 P53、VEGF的表达均随胶质瘤病理级别的升高而升高。Ⅰ～Ⅳ级病理分级中P53阳性率分别为22．22％(4／18)，65％(13／20)，75％(9／12)；VEGF阳性率分别为27．78％(5／18)，90％(18／20)，100％(12／12)。P53、VEGF的表达均与胶质瘤病理分级显著相关(P＜0．01)，P53和VEGF阳性表达符合率为76％(38／50)，两者的表达有显著性相关(P＜0．01)。结论 P53和VEGF蛋白的表达是判断胶质瘤生物学行为的重要指标；胶质瘤组织突变的P53基因可上调VEGF的表达，促进血管生成，进而影响胶质瘤的进展。     

Use of the microorganism Bacillus stearothermophilus as a model to evaluate toxicity of the lipophilic environmental pollutant endosulfan

Microorganisms are very powerful tools for the supply of information about the toxic effects of lipophilic compounds, since an impairment of cell growth usually occurs as a result of perturbations related, in most cases, with the partition of toxicants in membranes. The thermophilic eubacterium Bacillus stearothermophilus has been used as a model system to identify α- and β-endosulfan interactions with the membrane possibly related with the insecticide toxicity. Two approaches have been pursued: (a) bacterial growth is followed and the effects of endosulfan isomers determined; (b) biophysical studies with the fluorescent fluidity probe 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed to assess the effects of α- and β-endosulfan on the organization of the membrane lipid bilayer. The effects on growth were quantitatively evaluated by determination of growth parameters, namely the lag phase, the specific growth rate and the cell density reached by cultures in the stationary phase. Growth inhibition by α and β-endosulfan dependent on the concentration is diminished or removed by the addition of 2.5 m Ca²⁺ to bacterial cultures. Fluorescence DPH polarization consistently showed opposite effects of Ca²⁺ and α- and β-endosulfan on the physical state of bacterial polar lipid dispersions.     

东部马脑炎病毒E2基因与GM-CSF共表达质粒的构建及其免疫原性初步研究

目的:利用粒细胞-巨噬细胞集落刺激因子(GM-CSF)作为基因佐剂,提高东部马脑炎病毒E2基因重组质粒的免疫效果.方法:分别扩增E2基因与GM-CSF基因,连接进入含有内部核糖体插入位点(IRES)的真核表达载体中,构建共表达质粒.Lipofectamine2000介导转染真核细胞BHK-21,反转录PCR检测E2和GM-CSF两个基因的转录,Western印迹法和间接免疫荧光法(IFA)检测细胞内E2基因表达产物的抗原性.通过肌肉注射免疫BALB/c小鼠,IFA法测定血清抗体效价,FACS测定免疫小鼠脾细胞中CD4 /CD8 淋巴细胞构成比,初步观察共表达质粒的免疫原性.结果:经酶切鉴定与序列测定证明重组共表达质粒中含有E2和GM-CSF两个基因且序列正确.转染细胞的反转录PCR可见E2和GM-CSF两个基因的转录.Western印迹结果可见转染细胞的裂解液在相对分子质量50 000位置有特异性条带.将转染细胞制成荧光抗原片,经IFA检测可见胞浆中出现特异荧光.免疫小鼠的最高血清抗体效价为1:160,但细胞免疫未观察到明显的提高.结论:构建的共表达质粒pE2-IRES-mGM-CSF具有良好的免疫原性,能有效刺激小鼠特异性体液免疫应答,提高了E2基因重组质粒诱导的血清抗体效价.     

休克期切痂对烫伤大鼠全身和肠道局部免疫功能的影响

目的　观察休克期切痂对烫伤大鼠全身和肠道局部免疫功能的影响 ,探讨其可能的机制。　方法　选用 96只Wistar大鼠。取其中 2 4只大鼠的躯干部皮肤冻存于液氮中 ,另取 8只作正常对照组。余下 6 4只造成 30 %TBSAⅢ度烫伤后 ,随机分为A组 2 4只 ,伤后不作任何处理 ;B组 2 4只 ,伤后 2 4h腹腔注射等渗盐水 5 0ml/kg,一次性切痂后用上述冻存异体皮覆盖 ;C组 1 6只 ,伤后 72h进行处理 ,方法同B组。检测A、B组大鼠伤后 2、4、8d和C组伤后 4、8d及正常对照组大鼠的脾淋巴细胞增殖功能、血浆和肠组织白细胞介素 (IL)2水平、肠黏液分泌型免疫球蛋白A(sIgA)及肠组织中二胺氧化酶 (DAO)含量的变化。　结果　各时相点下A、B、C组大鼠脾淋巴细胞增殖功能、血浆IL 2水平、肠组织IL 2及肠黏液sIgA含量均较正常对照组减少。B组伤后 4、8d和C组伤后 8d的脾淋巴细胞增殖功能接近正常对照组 ,血浆和肠组织IL 2水平明显高于A组 (P <0.0 1)。伤后 4、8d,B组肠黏液sIgA含量分别为 (3.5 1± 2 .1 4 )、(3.0 3± 0 .95 )mg/g,C组分别为 (1 .4 0± 0 .6 4 )、(1 .5 2± 1 .2 6 )mg/g,B组较C组增加近 1倍 (P 0.0 1 )。A组伤后 4、8d肠组织DAO活性低于正常对照组和B组 (P 0.0 5)。结论　休克期切痂有助于烫伤大鼠全身和肠道