不同运动方式和时间对大鼠骨骼肌线粒体呼吸链复合体酶Ⅰ和Ⅳ活性的影响

背景：急性剧烈运动对机体可造成氧化应激,线粒体生成活性氧造成机体氧化应激和钙离子超负荷,导致骨骼肌功能下降,机体产生疲劳。然而长期规律运动后线粒体产生适应性变化,从而起到保护机体免受过多活性氧损害的作用。 目的：观察不同运动方式和时间对大鼠骨骼肌线粒体呼吸链复合体酶Ⅰ,Ⅳ活性的影响。 方法：48只健康雄性SD大鼠随机等分为正常对照组、无氧运动组、有氧运动组和交替运动组。在大鼠运动2,4,6周的时候分别处死,差速离心提取大鼠骨骼肌线粒体,分光光度法测定线粒体呼吸链复合体酶Ⅰ,Ⅳ的活性。 结果与结论：运动后有氧组、交替组与无氧组线粒体呼吸链复合体酶I的活性随时间先增强而后下降;运动后有氧组与交替组线粒体呼吸链复合体酶Ⅳ的活性随时间而增强,无氧组则下降。说明有氧运动在中长期耐力运动中可有效提高大鼠体内呼吸链复合体酶Ⅰ,Ⅳ的活性,而无氧运动则只能在短期内提高其活性,长时间无氧运动可能导致对线粒体呼吸链复合体酶的损伤,影响骨骼肌工作效率,造成机体疲劳。     

唇侧和舌侧托槽对变形链球菌黏附作用的比较研究

目的通过比较唇侧和舌侧托槽对变形链球菌的黏附作用是否存在差异,从而使医生和患者对这两种矫治器的应用有更明确的认识,以指导临床工作。方法选用美国Ormco公司生产的唇侧和舌侧托槽各40个,每种托槽分为10组,每组4个托槽。分别浸泡于变形链球菌的菌液中6h,然后将每组托槽分别在37℃TSB液体培养基中放置24、48、72h,然后用平板培养计数法计算每个样本在以上各时间点的黏附细菌数。结果在6、24、48、72h4个时间段,唇侧和舌侧托槽对变形链球菌的黏附均无显著性差异;唇侧和舌侧托槽对变形链球菌的黏附作用随时间增长均有增加的趋势。结论唇侧和舌侧托槽在使用时,都应该采取预防和控制菌斑的措施,保护患者牙体和牙周的健康。     

污水养殖鱼肉有机提取物致突变性研究

目的：评价污水养殖鱼的细胞遗传毒理学安全性，方法：用小鼠骨髓细胞的微核试验对采自天津市南、北排污河流域污水养鱼池的污养鱼肉有机提取物进行致突变性检测。结果：本次采集的3组污养鱼肉有机抽取物均呈致突变阳性结果，而清养鱼有机提取物呈致突变阴性结果，结论：污水养殖鱼体内含有有机致突变物质，这些物质会通过食物链进入人体，可能对人群健康产生潜在危害。     

LPS-induced NF-κB activation requires Ca2+ as a mediator in isolated pancreatic acinar cells of rat

Objective To investigate the effect of Ca2+ on lipopolysaccharide (LPS)-induced NF-κB activation in pancreatic acinar cells and the role of NF-κB in LPS-induced acinar cell injury. Methods Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to varying concentrations of LPS (from 1 to 20 mg/L) in the presence or absence of EGTA. At various time points (30 minutes, 1 hour, 2 hours, 4 hours and 10 hours) after treatment with the agents, cell viability was determined by MTT. Nuclear translocation of NF-κB’s subunit p65 was visualized by immunofluorescence staining and nuclei protein was extracted to perform EMSA which was used to assay the activity of NF-κB binding to the DNA sequence containing the recognition site of NF-κB. Results LPS induced cell damage in a time- and concentration-dependent manner while EGTA attenuated LPS-induced cell damage (P<0.05). NF-κB p65 immunofluorescence staining had increased intensity in the cytoplasm and indicated that nuclear translocation occurred within 30 minutes and its zenith was reached at 1 hour after LPS (10 mg/L) treatment. Testing of NF-κB DNA binding activity showed the same alteration phase as p65 immunofluorescence staining. NF-κB activation preceded the pathological alteration of pancreatic acinar cells. The Ca2+ chelator EGTA inhibited LPS-induced NF-κB activation. Conclusions NF-κB activation is an important early event in LPS-induced injury to pancreatic acinar cells. Ca2+ is an important mediator in the process of LPS-induced NF-κB activation.     

Comparison of cell-suspension and explant culture of rabbit limbal epithelial cells

Currently, most investigators directly use limbal explants to culture corneal epithelial cells. However, it has not been identified that limbal stem cells do readily migrate from the limbal explants onto culture plate or amniotic membrane carrier. In this study a cell-suspension culture system for rabbit limbal stem cells was developed and compared with the direct explant method in the aspect of stem cells content in the culture system. Rabbit limbal epithelial cells were dissociated from rabbit eyes by dispase and single cell suspension was made for cell-suspension culture. DeltaNp63 expression of cultured rabbit limbal epithelial cells by cell-suspension technique and explant technique was detected. In cell-suspension culture, isolated cell-suspension was evaluated by flow cytometric analysis for vimentin expression and residual limbal tissue after dispase treatment was examined by scanning electron microscopy. In limbal epithelial cells suspension less than 5% cells were vimentin positive. Examination of residual limbal tissue confirmed that all the limbal epithelial cells had been removed. Histological examination revealed that with cell-suspension culture the cultured epithelial cells could differentiate better than with explant technique. In cells cultured with cell-suspension, there were much more cells expressing DeltaNp63 than in explant cultured cells. In cells cultured with explants, most of DeltaNp63 labelling cells mustered around the explants, and peripheral cells on the slides were DeltaNp63 negative. These results suggested that with pure limbal epithelial cells suspension including basal cells, which could directly enter into culture system, cell-suspension culture technique was significantly superior to explant culture technique in terms of stem cells content.     

鼾症——脑出血的预报因素(两对照组配比病例对照研究)

本文采用两种对照组配比病例对照研究方法,通过条件logistic回归分析,对162例经颅脑CT扫描确诊的脑出血病人以及社区对照和医院对照,分别作1:1配比分析,以探讨鼾症与脑出血的关系.单因素分析结果表明,病例与社区对照比较以及病例与医院对照比较,打鼾者患脑出血的OR分别为2.43(95%CI:2.77～3.34)和2.10(95%CI:1.60～2.76).控制高血压和体重的作用后,OR分别为1.92(95%CI:1.27～2.91)和1.63(95%CI:1.22～1.17),仍具有统计学意义,经常打鼾很可能是脑出血独立的预报因素.本文还对本研究方法学特点进行了讨论.     

正交试验优化冬凌草中冬凌草甲素的提取工艺

目的:进行冬凌草甲素的提取工艺筛选和含量测定,为其临床应用及生产提供实验依据。方法:以正交试验筛选冬凌草甲素的提取工艺,采用HPLC法测定冬凌草甲素的含量。结果:优选冬凌草甲素的提取工艺为75%乙醇回流提取2次(1 h,1 h),以药材质量2%的活性炭脱色10 min。结论:该提取工艺得到的冬凌草甲素含量较高且提取时间较短,经HPLC法检测冬凌草甲素,重现性好,回收率高。     

蛋白酪氨酸磷酸酯酶-1B抑制剂的研究进展

蛋白酪酸磷酸酯酶-1B（PTP-1B）是蛋白酪氨酸磷酸脂酶（PTP）家族中最具代表性的成员，因其参与多种生理过程尤其是与机体对胰岛素的敏感性紧密相关，目前已经成为糖尿病和肥胖症治疗的新靶点。现从PTP简介、PTP-1B的结构、生理功能及6类抑制剂的结构性质等方面进行综述。     

Detection of Frameshift Mutations of the Transforming Growth Factor β Receptor Ⅱ in Gastric Cancers with Microsatellite Instability

OBJECTIVE To study the relationship among microsatellite instability （MSI）, frameshift mutations （FM） of the transforming growth factor β receptor Ⅱ （TGF β R Ⅱ）, methylation state of the hMLH1 promoter and hMLH1 protein expression level in gastric cancers, and to explore their relationship to gastric carcinogenesis. METHODS DNA was isolated from 101 gastric specimens and 5 microsatellite loci were detected. PCR, electrophoresis on denatured polyacrylamide gels and silver staining were performed to detect the MSI. The FMs of TGFβR Ⅱ were also screened with the same method. HMLH1 methylation was analyzed by methylation specific PCR （MSP） and sequencing. HMLH1 protein expression was detected using immunohistochemistry. RESULTS The incidence of MSIs was 53.7% and 0% in the cancers and normal tissues, respectively, with the frequency of MSIs being significantly higher in the gastric cancers compared to the normal gastric tissues （P〈0.05）. The frequency of hMLH1 methylation was 41.5%（17/41） in the gastric cancers and 0%（0/60） in the normal group. Decreased hMLH1 expression was observed in 94.1%（16/17） of cases exhibiting methylation. FMs of TGFβR Ⅱ were identified in 5 （62.5%） of the 8 samples with MSIH. In contrast, FMs were not found in MSI-L or microsatellite stable （MSS） cases. CONCLUSION MSIs and FMs of TGFβR Ⅱ may play an important role in gastric carcinogenesis. HMLH1 methylation is an important modification of the DNA which results in inactivation of hMLH1 and mismatch repair defects which lead to MSls and FMs of TGFβR Ⅱ.     

大豆异黄酮对小鼠脑缺血再灌注损伤的保护作用

大豆异黄酮(soybean isoflavone,SI)属生物类黄酮,主要是指以3-苯并吡喃酮为母核的化合物,主要有3类,即染料木甙类(genistin)、大豆甙类(daidzin)、6-甲氧基大豆甙类(glycitin)。目前,大量体内外实验和人群流行病学调查均发现大豆异黄酮具有广泛的生物学功效,如降低血脂、抗动脉粥样硬化、防治癌症和改善妇女更年期症状等。本研究在国内率先以脑缺血再灌注小鼠为模型,探讨SI对大脑损伤的保护作用。1材料与方法1.1材料1.1.1药品与试剂:大豆异黄酮(纯度40%,其中染料木黄酮22.34%,大豆苷元17.92%),购自天津市康宁生物化学工程有限公司;超氧化…