In vitro assembly of infectious nucleocapsids of bacteriophage phi 6: formation of a recombinant double-stranded RNA virus.

A system is described for assembling infectious bacteriophage phi 6 nucleocapsids in vitro. Procapsids encoded by cDNA copies of genomic segment L in Escherichia coli were used to package and replicate viral RNA segments. The resulting filled particles were shown to be capable of infecting host cell spheroplasts after incubation with purified nucleocapsid shell protein P8. The infected spheroplasts yielded infectious virions. A modified cDNA-derived RNA segment was inserted into virions by this method. The resulting infectious virions contained the same 4-base-pair deletion as the modified cDNA. These findings support the contention that the preformed procapsids are the "machine" that replicates the phi 6 genome, by showing that the cDNA-derived procapsids are competent to package and replicate RNA properly.     

偶联剂CGE（N）—R型处理前后牙本质的表面状态及其...

In order to research the states of dentine surface and dentine surface primed with coupling agent, we used microscope, transmission electron microscope (TEM) and solid fluorescence method. Observed under microscope, patterning of dentinal tubules and their poles was very explicit; through the view of interface between coupling agent adsorbed and human dentine powder by TEM, it was revealed that the coupling agent was adsorbed onto the dentine surface as if it "grew out" of the dentine surface; through examination of interface between the coupling agent adsorbed and dentine surface by fluorescence spectrum, which differed from that of the coupling agent or dentine surface, i.e., this fluorescence spectrum of interface changed obviously (red shift). This phenomenon indicated that there was a chemical reaction occurring between tooth surface and adsorbed coupling agent. Therefore we can conclude that the three examinations are necessary to provide the argument for establishment of chemical bonding mechanism between dentine and coupling agent.     

Determination of trace selenium in human body by anodic stripping voltammetry at gold-disc electrode

Summary For determination of trace Se we used high-pressure wet digester to pretreat the specimens obtained from the human body. This method is very effective in preventing loss of Se by volatilization which often occurs in the sample pretreatment. We studied the method of using anodic stripping voltammetry at gold-disc electrode to measure the trace Se present in the human body and found it to be the optimal procedure. The detection limitation was about 2x10⁻⁸ g/L, the recovery rate of Se about 96.6±6,7 % , and the coefficient of variation CV = 7.0%.     

5-氨基水杨酸灌肠对大鼠免疫性结肠炎的影响

目的 探讨5-氨基水杨酸(5-ASA)灌肠对大鼠三硝基苯磺酸(TNBS)诱导的结肠炎的作用.方法用TNBS诱发大鼠结肠炎.造模7天后,用不同剂量的5-ASA(25、50、100mg·kg-1·d-1)开始灌肠.观察大鼠粪隐血(OB)反应强度、结肠大体形态和组织学改变,并检测肠黏膜髓过氧化物酶(MPO)活性.结果 5-ASA灌肠可明显降低结肠黏膜损伤指数(CMDI)、OB反应强度、MPO活性及组织学评分(HS),各剂量组间有一定的量效关系.结论 5-ASA灌肠对TNBS诱导的大鼠结肠炎有保护作用,且与剂量有一定关系.     

提高大脑皮质神经元细胞产率以及活性的研究

目的　提高培养大脑皮质神经元的产率以及活性 ,使实验的细胞模型有良好的一致性和可比性。方法　实验分析了大脑皮质神经元培养过程中 ,从选材、取材到分散细胞等一系列步骤中维持细胞活性的内在因素 ,应用细胞形态学指标 ,Trypanblue染色计数分析以及染色观察。结果　每侧大脑皮质得到细胞约 2 .5× 10 6～ 3.0× 10 6个 ,而且种植不同时间 6 ,12 ,48h细胞存活率均在 95 %以上。结论　该法是较好的大脑皮质神经元培养方法。     

牙龈卟啉单胞菌感染对载脂蛋白e基因敲除小鼠动脉粥样硬化的影响

目的: 探讨牙龈卟啉单胞菌(Porphyromonas gingivalis,P. gingivalis)引起的炎症和氧化应激反应对动脉粥样硬化的影响及作用机制。方法: 采用8周龄载脂蛋白e基因敲除(ApoE knockout,ApoE-/-)小鼠建立动脉粥样硬化动物模型,将小鼠随机分为两组:(1)磷酸盐缓冲液(phosphate buffered saline,PBS)健康对照组:8只ApoE-/-小鼠,普通饮食+PBS鼠尾静脉注射;(2)P. gingivalis感染组:8只ApoE-/-小鼠,普通饮食+P. gingivalis鼠尾静脉注射。1周3次,隔天1次,共10次。4周后处死,取心脏组织进行油红O染色,血清进行酶联免疫吸附测定(enzyme-linked immunosorbent assay,ELISA),主动脉进行实时荧光定量PCR以及Western blot检测。结果: P. gingivalis 感染组较PBS健康对照组可以显著加重ApoE-/-小鼠动脉粥样硬化斑块的形成,增加血清中炎症介质,如白细胞介素(interleukin,IL)-1β、IL-6和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)以及氧化应激介质8-羟脱氧鸟苷(8-hydroxy-2-deoxyguanosine,8-OHDG)表达,增加主动脉组织中IL-1β、IL-6、TNF-α、NADPH 氧化酶(NADPH oxidase,NOX)-2和NOX-4基因的mRNA水平。P. gingivalis感染后在主动脉组织中观察到核转录因子-κB(nuclear factor-kappa B,NF-κB)表达有增高趋势。结论: P.gingivalis感染会加速ApoE-/-小鼠动脉粥样硬化进程,诱导氧化应激和炎症反应;NF-κB信号通路可能是P. gingivalis加速动脉粥样硬化形成的重要作用机制。     

羊红膻根中羊红膻素H等的分离与鉴定

从草药羊红膻Ｐｉｍｐｉｎｅｌｌａ ｔｈｅｌｌｕｎｇｉａｎａ Ｗｏｌｆｆ。根降压有效部位中首次分得５个化合物,经光谱（ＵＶ,ＩＲ,ＭＳ,＾１ＨＮＭＲ,＾１３ＣＮＭＲ,＾１Ｈ－＾１ＨＣＯＳＹ,＾１Ｈ－＾１３ＣＣＯＳＹ,ＤＥＰＴ）解析,鉴定为５－甲氧基－２－甲基苯骈呋喃（Ｉ）,甘油二乙酸酯（Ⅱ）,异香草醛（Ⅲ）,棕榈酸（Ⅳ）,油酸（Ⅴ）,其中化合物Ｉ为具有降压活性的新化合物,命名为羊红膻素Ｈ;化合物Ⅱ～     

胃癌相关抗原MG7-Ag模拟肽表位的筛选及测序分析

目的　从噬菌体呈现的随机肽库中筛选胃癌单克隆抗体MG7所识别的胃癌相关抗原的短肽模拟表位 ,为进一步研究胃癌相关抗原与单抗结合的结构基序奠定基础。方法　用胃癌单克隆抗体MG7对呈现于噬菌体衣壳蛋白pⅧ上的 2个九肽库分别进行亲和富集和免疫筛选 ;阳性克隆进一步用荧光标记和硝酸纤维素膜斑点印迹法证实其结合活性 ;经随机抽取部分阳性克隆进行DNA序列分析 ,推导出相应噬菌体呈现肽的氨基酸序列 ,通过序列比较分析相对保守的表位信息 ;运用HLA分子结合分析软件预测已测序短肽与HLA分子结合的可能性。结果　经反复多轮筛选和结合活性检测 ,从pⅧ和pⅧ cys 2个噬菌体肽库中分别得到了 12和 30个阳性克隆 ;通过对部分阳性克隆进行测序分析 ,推导相应的随机肽序列和序列比较分析 ,得到具有相对保守性的表位信息如PLX0 2 S、SAVR、XRMX、YARN等。经计算机预测分析 ,发现它们可与HLA多个分子结合。结论　PLX0 2 S、SAVR、XRMX、YARN等有可能为胃癌单克隆抗体MG7所识别的表位基序。     

肺炎支原体感染伴心肌受累(附46例分析)

近年来国内外陆续有对肺炎支原体 (MP)肺外脏器受累和心脏受累的报道 ,为了进一步研究证实我地区该病的心脏受累情况及发生率。方法 :对 30 7例门诊及住院确诊为MP感染的患儿进行临床、心电图、胸部X线检查 ,并记录有关症状和体征 ,必要时测心肌酶谱 ,对发现有心脏受累者除按MP感染治疗外尚给予心脏支持疗法 ,并定期随访。结果 :有心脏受累者 46例、占 1 4 9% ,平均年龄 9 8±S1 72a。结论 :本文心脏受累者占MP感染的发生率较文献报道 (4 9% )明显为高 ,可能与多数患儿发病年龄较大存在再感染有关。我们认为凡MP感染的患儿应把心电图检查做为常规检查项目。     

病态嗓音的计算机定量评估

观察各类喉病患者嗓音声学参数及声谱图特征,探讨计算机声学测试技术在病态嗓音评估中的应用价值。方法采用计算机嗓音声学测试系统对７８例正常成人及９８例喉病患者元音信号进行检测,对其主要声学诊断及声谱图特征进行分析,并与主观听觉评价结果进行了比较。