Once an ischemic stroke occurs, reactive oxygen species (ROS) and oxidative stress degrade the tight connections between cerebral endothelial cells resulting in their damage. The expression of antioxidant genes may be enhanced, and ROS formation may be reduced following Nrf2 activation, which is associated with protection against ischemic stroke. Overexpression of spermine oxidase (Smox) in the neocortex led to increased H2O2 production. However, how Smox impacts the regulation of the blood-brain barrier (BBB) through antioxidants has not been examined yet. We conducted experiments both in the cell level and in the transient middle cerebral artery occlusion (tMCAO) model to evaluate the effect of Smox siRNA lentivirus (si-Smox) knockdown on BBB protection against ischemic stroke. Mice treated with si-Smox showed remarkably decreased BBB breakdown and reduced endothelial inflammation following stroke. The treatment with si-Smox significantly elevated the Bcl-2 to Bax ratio and decreased the production of cleaved caspase-3 in the tMCAO model. Further investigation revealed that the neuroprotective effect was the result of the antioxidant properties of si-Smox, which reduced oxidative stress and enhanced CD31+ cells in the peri-infarct cortical areas. Of significance, si-Smox activated Nrf2 in both bEnd.3 cells and tMCAO animals, and blocking Nrf2 with brusatol diminished the protective effects of si-Smox. The study findings suggest that si-Smox exerts neuroprotective effects and promotes angiogenesis by activating the Nrf2 pathway, thus decreasing oxidative stress and apoptosis caused by tMCAO. As a result, si-Smox may hold potential as a therapeutic candidate for preserving BBB integrity while treating ischemic stroke.

在专业课程中融入思政元素是实现立德树人的重要手段,病原生物学实验课是理论联系实践的重要课程,是培养学生科学与人文素养的重要阵地.本文阐述在该课程中融入思政元素的重要意义及实施路径,为教学中实现专业知识传授与思想价值引领的有机结合、进而与思想政治理论课同向同行奠定基础.

目的 探究norD编码的超家族转运蛋白NorD对耐甲氧西林金黄色葡萄球菌生物膜形成的影响.方法 使用耐甲氧西林金黄色葡萄球菌MW2野生株和norD基因缺失株及norD互补菌株,微孔法培养形成生物膜,同时使用番红染剂对形成的生物膜染色,通过酶标仪检测特定波长下的A值,对细菌生物膜形成定量分析.结果 常规培养时,MW2野生株和MW2 norD缺失株生物膜的形成比较差异无统计学意义(P＞0.05).低Fe2+离子环境下,MW2 norD基因缺失株培养48 h,生物膜形成的量少于MW2(t=3.878,P=0.0082).结论 MW2 norD基因缺失株在低Fe2+离子环境下引发生物膜分解,提示NorD可促进Fe2+离子环境下生物膜的形成.

实验教学是医学微生物教学中不可或缺的组成部分,不但可以有效促进理论课教学内容的消化吸收,还能培养学生分析问题和解决问题的能力,因此实验教学也是教学改革的重要环节.从医学微生物学实验教学角度出发,结合七年制和本科教学实践,概括了医学微生物学实验教学改革的内容,从明确教学目的、开展设计式教学、采用多样化教学手段和融入人文教育这几个方面介绍改革经验.

OBJECTIVE:To develop and evaluate the efficiency of air purification and sterilization instrument based on nano-sized TiO(2) photocatalytic technique. METHODS:The nano-sized TiO(2) photocatalytic air purification and sterilization instrument was designed and a sample had been prepared. The sterilization efficiencies for E.coli and Klebsiella by the nano-sized TiO(2) photocatalytic instrument and ultraviolet (UV) were measured in closed labs. The on-site efficiency of the instrument was evaluated, too. RESULTS:The nano-sized TiO(2) photocatalytic air purification and sterilization instrument was composed of five units: rough filter, nano-sized TiO(2) photocatalytic unit, activated carbon fiber filter, negative ion generator, and programmed control unit. The E.coli killing rates by the nano-sized TiO(2) photocatalytic instrument were 76.0%, 81.8%, 77.5%, and 80.7% at 30, 60, 90, and 120 minutes, respectively. There was no significant difference between the E.coli killing rates of the instrument and UV (P > 0.05), except the 120 minutes timepoint. The Klebsiella killing rates by the instrument were 78.4%, 79.5%, 67.3%, and 58.5% at 30, 60, 90, and 120 minutes, respectively. The Klebsiella killing efficiencies of the instrument at 30 and 60 minutes were better than that of UV (P < 0.01). There was no significant difference between the Klebsiella killing efficiencies of the instrument and UV (P > 0.05). CONCLUSION:The air sterilization efficiency of the nano-sized TiO(2) photocatalytic instrument should be equivalent or better as compared with the UV. This instrument might be used for the air purification and sterilization of the public locations.

By mean of construction of pathogenic biology laboratory teaching base,and the development of reforms of teaching methods as well as student's extracurricular activities,students' innovative abilities were developed.In addition,student's mental and scientific qualities were improved,and teaching quality was promoted.The role of teaching laboratory was then upgraded to be a teaching base for improving student's overall quality and innovative ability.

OBJECTIVE To establish the random amplification of polymorphic DNA (RAPD) typing technology for Proteus strains and apply it in the epidemiology investigation. METHODS To optimize the experiment condition of random amplification DNA polymorphic fingerprinting technique. Fingerprinting map of 21 Proteus strains were tested by RAPD. RESULTS Twenty one Proteus strains were divided into 18 distinct genotypes, among them 16 P. mirabilis strains were divided into 13 distinct genotypes and 5 from P. vulgaris strains. CONCLUSIONS RAPD provides markers for typing of clinical strains and it is suitable for molecular epidemiology studies with high typeability, simplicity and rapidness.

分析黑龙江省分离的肺炎克雷伯菌产超广谱β-内酰胺酶基因片段的序列,确定该基因所产ESBLs的亚型.用双纸片法初筛检测产ESBLs菌株,聚合酶链反应扩增ESBLs编码基因片段,并将其克隆至pUC19载体中,双脱氧链终止法测定核苷酸序列以确定亚型.测序结果证实所获得的ESBLs基因片段含1 047个核苷酸,其基因型为SHV型,与SHV-12型ESBLs编码基因相同.上述结果表明,黑龙江省内分离的产超广谱β-内酰胺酶肺炎克雷伯菌含有SHV-12编码基因.

比较产超广谱β-内酰胺酶克雷伯菌与大肠埃希菌质粒的表型与分布.用BlaTEM引物经PCR技术将51林克雷伯菌与29株大肠埃希菌编码产超广谱β-内酰胺酶的质粒扩增,琼脂糖凝胶电泳分离目的片段后得到完整的质粒电泳图谱.克雷伯菌与大肠埃希菌存在有相同大小的产超广谱β-内酰胺酶的质粒.2种细菌有产ESBL相同质粒,PCR技术可用于产超广谱β-内酰胺酶细菌质粒的分析.

By using short single oligomer primer with arbitrarily chosen sequences in polymerase chain reaction, randomly amplified polymorphic DNA (RAPD) was applied in differentiating clinical isolates of 52 Klebsiella pneumoniae and 28 Staphylococcus aureus. RAPD produced multiple polymorphic DNA bands when K. pneumoniae DNA was used as template. Using DNA fingerprints technique, the similarity coefficients values of 52 K. pneumoniae was measured and calculated, and dendrogram was drawn. The 52 Klebsiella pneumoniae were divided into 7 Patterns. But in the 28 Staphylococcus aureus, 3 characteristic lands were obtained. Minor differences in the RAPD fingerprints were detected. The research findings demonstrated that RAPD has a potential as a widely useful tool in providing genotypic characters for taxonomic descriptions and molecular epidemiology study.

目的探讨草绿色链球菌的基因分型,比较菌株间基因差异,寻找流行菌株与疾病的关系,为临床提供流行病学资料. 方法设计17 bp随机引物,采用随机扩增多态DNA(random amplified polymorphic DNA ,RAPD)技术对从临床标本中培养分离出的30株草绿色链球菌进行分析. 结果 17 bp随机引物将30株细菌扩增出12条特征性带,分为独特而稳定的3个型别, 型别Ⅱ在引起咽炎的菌株中占的比例相对较多. 结论 RAPD技术是细菌基因分型及分子流行病学研究的好方法,在调查监控医院感染流行株方面有重要的临床意义.

Objective: To analyse the genomic polymorphysm of three subspecies of Klebsiella pneumoniae by pulsed-field gel electrophoresis (PFGE). Methods: The genomic DNA was digested with 40U of Xba I restriction endonuclease and then PFGE was carried out with CHEF-III system. Results: A total of 15 types and subtypes were identified by PFGE which showed DNA polymorphism of this species and specific fragments of subspecies were selected. Conclusion: PFGE is an accurate and liable typing method to analyze Klebsiella pneumoniae. It can be used as epidemiological surveillance.

目的对伤寒、鼠伤寒沙门菌染色体结构进行比较分析,以便进行流行病学监测,为认识细菌的遗传进化和致病性奠定基础.方法分别用Xba1和Spe1酶切、消化细菌染色体,结合脉冲凝胶电泳技术对哈市几所医院分离到的12株伤寒沙门菌和3株鼠伤寒沙门菌进行染色体结构分析.结果两型沙门菌染色体经此两种酶切后分别产生18、17和16、15个片段,包括鼠伤寒沙门菌标准株在内的3株鼠伤寒和12株伤寒沙门菌染色体总长度分别为4765kb和4725kb.结论实验显示沙门菌染色体结构大致相同,但酶切位点及片段长度有所区别,由此推测可能是两者感染宿主与致病性不同的原因.

[目的]比较伤寒沙门菌与鼠伤寒沙门菌染色体结构差异,追溯其进化根源,以便对其进行流行病学研究.[方法]用I-CeuI脉冲凝胶电泳技术对哈市几所医院分离的12株伤寒沙门菌和3株鼠伤寒沙门菌进行染色体结构分析,并构建I-CeuI物理图.[结果]两型沙门菌染色体经酶切电泳后均产生7个片段;其染色体总长度分别为4765kb和4725kb.[结论]实验中全部沙门菌染色体结构大致相同,但伤寒沙门菌染色体中存在插入与删除序列,推测可能是两者感染宿主与致病性不同的原因.

肺炎克雷伯菌(Klebsiella pneumoniae)为周围环境及人肠道、呼吸道长居菌群,也是常见的机会病原菌.

[目的]对凝固酶阴性葡萄球菌进行DNA分型并分析其多态性,为临床提供流行病学资料.[方法]用随机设计10、17、18bp的三种引物,分别对实验菌株DNA做RAPD.[结果]18bp的引物扩增的产物最理想,以其图谱的差异对临床分离株DNA分析后,20株区分为5个型别.其中属Ⅰ型者含株数多,为16/20占总数的80%.[结论]RAPD技术能在DNA水平上对凝固酶阴性葡萄球菌分型,以其方法快捷、可靠、经济的优点可适用于该菌致医院感染源的追踪及流行病学研究.

[目的]应用RAPD技术分析甲型溶血性链球菌DNA多态性并对其分型.[方法]随机设计17bp和10bp两条引物,采用近年来建立起来的RAPD技术对30株甲型溶血性链球菌DNA进行扩增,扩增产物经凝胶电泳后得到指纹图.[结果]共出现12个DNA条带,根据指纹图的异同将其分为Ⅰ、Ⅱ、Ⅲ型别.[结论] 甲型溶血性链球菌DNA用RAPD技术分析,把该菌进一步分型且方法操作简便,结果准确、稳定.

沙门菌属(Salmonella)是肠杆菌科家族中的成员,属内有五个亚属,包括2500多个血清型.因该属细菌中不同的种、型往往具有很强的宿主特异性,故能在哺乳类、鸟类和爬行类等多种动物中引起疾病.多年来对该属细菌的研究主要基于宿主特异性、是否存在特异性表面抗原及对噬菌体的敏感性等表型特征.随着分子生物学技术的发展,尤其近年来迅速兴起的脉冲凝胶电泳(Pulsed-field gel electro phoresis,PFGE)技术的应用,已在基因水平对沙门菌属细菌进行分析,找出属中菌间遗传方面的差异及进化根源,进而对病原菌进行流行病学研究,以便找到更好的预防和控制方法.现将PFGE技术在沙门菌属染色体结构分析中的应用综述如下: