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%.     

Expression and function of c-kit receptor in bone marrow mononuclear cells of patients with myelodysplastic syndromes

目的　了解骨髓增生异常综合征 (MDS)骨髓单个核细胞c kit受体的表达与功能。方法　采用免疫荧光方法测定c kit受体蛋白 (CD117)的表达 ;逆转录 聚合酶链反应方法测定c kitmRNA的表达 ;细胞培养检测c kit受体的功能。结果　CD117表达率正常人为 3 0 4 %± 1 4 9% ,MDS患者为 8 58%± 5 2 8% ,两者差异有显著性 (P <0 0 5) ;RA患者为 5 12 %± 2 13% ) ,RAEB RAEB t患者为 10 0 1%± 5 0 7% ,两者差异有显著性 (P <0 0 5) ;MDS继发白血病患者为 32 4 3%± 18 16 %。MDS患者c kit基因mRNA表达与CD117表达相一致。正常骨髓单个核细胞体外半固体培养 ,在加入造血干细胞因子、白细胞介素 3、红细胞生成素 (SCF IL 3 Epo)后形成的粒 巨噬细胞集落 (CFU GM)较仅加入IL 3 Epo显著增多 (P <0 0 5) ,红系爆式集落 (BFU E)数量极显著增多 ,且BFU E体积显著增大(P <0 0 1)。MDS患者在上述相同条件下CFU GM数量无明显变化 (P >0 0 5) ,与正常对照比较 ,CFU GM和BFU E数量均显著减少 (P <0 0 5)。结论　MDS患者骨髓单个核细胞CD117表达明显高于正常对照 ,且与病情进展相关 ;c kitmRNA表达与CD117表达相一致 ;MDS患者骨髓单个核细胞体外培养时 ,SCF协同IL 3、Epo促进造血干 祖细胞增殖分化能力较正常对照明     

CagA阳性幽门螺杆菌感染与上胃肠道疾病关系的研究

目的探讨CagA阳性幽门螺杆菌(Hp)感染与上胃肠道病变的关系;并观察Hp根除治疗后血清中抗CagAIgG抗体水平的变化.方法808例因上胃肠道症状而接受胃镜检查的病人,同时作Hp检查.对Hp感染者用ELISA方法检测血清中抗CagAIgG抗体;阳性者予含质子泵抑制剂(PPI)三联疗法根除治疗.其中60例根除治疗失败病人和120例根除成功病人在Hp根除治疗结束3个月和6个月时复查血清中抗CagAIgG抗体水平.结果在不同临床疾病中,慢性浅表性胃炎(CSG)、慢性萎缩性胃炎(CAG)、胃溃疡(GU)、十二指肠溃疡(DU)和胃癌(GC)感染Hp的病人中抗CagAIgG抗体阳性率分别为55.4%、70.5%、83.2%、90.8%、89.7%.后4组阳性率明显高于CSG组,后3组均明显高于CAG组;在不同程度的胃粘膜病变中,CSG、CAG、肠上皮化生(IM)、非典型增生(Dys)和GC感染Hp的病人中抗CagAIgG抗体的阳性率分别为43.0%、53.8%、77.6%、88.6%、89.7%.IM、Dys和GC组均明显高于CSG和CAG组;60例根除失败者在治疗前及治疗后3个月和6个月时血清中抗CagAIgG水平分别为(72±41)U/ml,(67±36)U/ml和(69±40)U/ml,治疗前后差异无显著意义,无一例转为阴性;120例根除治疗成功者治疗后3个月和6个月血清中抗CagAIgG水平平均由(69±38)U/ml分别下降至(47±30)U/ml和(32±15)U/ml,治疗后与治疗前比较差异均有显著意义,在治疗后3个月和6个月时分别有7.5%(9/120)和19.2%(23/120)的病人抗体转为阴性.结论CagA阳性的Hp可能导致更严重的上胃肠道疾病和更严重的胃粘膜病变;Hp根除治疗后血清中抗CagAIgG抗体水平明显下降,但下降较慢,不宜作为个体监测疗效的指标.     

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。     

高效液相色谱蒸发激光散射检测器分析西洋参中的人参皂甙

目的：采用高效液相色谱蒸发激光散射检测器测定西洋参中人参皂甙的含量。方法：色谱柱为NH2柱,并以乙腈－水－异丙醇（80：20：15）和水作为梯度洗脱流动相,蒸发激光散射检测器。定量方法简单,准确。结果：回收率为95.97%-100.05%,相对标准偏差为0．87％－2．75％。结论：该法可作为西洋参质量控制方法。     

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。     

老年Ⅱ型糖尿病患者血清C反应蛋白与血糖相关性分析

目的 :考察老年Ⅱ型糖尿病 (NIDDM)患者血清C 反应蛋白水平及其与血糖水平的相关性。方法 :选取老年NIDDM患者 183例 ,其中病史 5年以上血糖控制良好、无并发症且无感染性疾病者 97例 ;初次确诊、血糖控制不良者 86例 ,其中无感染性疾病者 5 0例 ,有急性腹泻或尿路感染者 36例。未患NIDDM者 70人作为对照组 ,其中 35人为健康体检者 ,另 35人为有发热性疾病、有症状的感染或慢性感染性疾病患者。测定空腹血糖和C 反应蛋白浓度。结果 :老年NID DM患者血清C 反应蛋白水平显著升高 ,结论 :高血糖可能是血清C 反应蛋白水平增高的相关因素。