新型鸭呼肠孤病毒RT-LAMP检测方法的建立

建立适于基层实验室快速检测新型鸭呼肠孤病毒(Novel duck reovirus,NDRV)的一步反转录环介导等温扩增(RT-LAMP)方法。基于新型鸭呼肠孤病毒S3基因的6个保守区域设计了4条LAMP引物,利用Bst DNA聚合酶在63℃恒温保持45 min即可完成反转录和扩增反应,由此建立了RT-LAMP检测方法。该方法具有良好的特异性,除NDRV外对其他6种常见鸭病的检测结果均为阴性。该方法对病毒RNA的最低检出量为0.1 pg,是常规RT-PCR方法的100倍。临床应用结果表明,该方法与病毒分离鉴定方法的符合率为98%,而且对仪器的要求低,适于基层实验室和现场检测。     

改良逆转录环介导等温扩增检测技术快速实时检测H9亚型禽流感病毒

利用改良逆转录环介导等温扩增(RT-LAMP)技术建立一种快速、灵敏的检测方法用于H9亚型禽流感病毒检测。根据H9亚型禽流感病毒血凝素(HA)基因保守区序列中的8个区段设计6条特异性引物,在恒温条件下进行核酸扩增反应,并以琼脂糖凝胶电泳和目视检查绿色荧光两种方法对扩增结果进行判定。结果表明,RT-LAMP的最小检测限为100 fg,灵敏度比PT-PCR高100倍,且与H5亚型、H7亚型禽流感病毒,新城疫病毒(NDV)无交叉反应。目视检查绿色荧光与常规琼脂糖凝胶电泳的判定结果一致。整个扩增检测过程在35 min内即可完成。利用临床样本对RT-LAMP法进行验证,结果与RT-PCR一致。由实时浊度分析得到的标准曲线,计算出临床样本中的病毒质粒拷贝数均在2×107-2×104之间。因此,本研究建立的RT-LAMP方法快速、灵敏、特异性强,是H9亚型禽流感病毒的一种高效检测方法。     

A组轮状病毒可视化RT-LAMP方法的建立

【目的】建立一种利用颜色判定的快速、简单、灵敏度高的检测方法,即可视化的逆转录环介导等温扩增(RT-LAMP)方法,并应用于人A组轮状病毒的基因检测。【方法】针对A组轮状病毒VP6基因的6个保守区域设计4条特异性引物,在64 °C恒温条件下进行核酸扩增反应1 h,在扩增前加入染料钙黄绿素(Calcein)作为反应指示剂,以钙黄绿素的颜色变化作为结果判定标准。评价该方法的特异性和灵敏度,并同时利用RT-LAMP和RT-PCR两种方法对90份临床腹泻样本中的病毒核酸进行检测。【结果】RT-LAMP方法特异性较高,灵敏度可以达到103 copies/μL RNA分子水平,比RT-PCR高出100倍。对临床标本的检出率与RT-PCR方法相当。【结论】建立的RT-LAMP法灵敏度较高,特异性强,节省时间,结果可视化,具有野外检测和现场快速检测的潜力。     

猪轮状病毒RT-LAMP检测方法的建立及应用

为了建立一种适用于猪轮状病毒(PoRV)的逆转录-环介导等温核酸扩增(RT-LAMP)的快速、灵敏检测方法。依据GenBank上登录的PoRV VP7基因保守序列,设计了6条特异性引物,通过对外引物与内引物浓度比、Bst DNA聚合酶浓度、Mg2+浓度、dNTP浓度和反应条件等进行优化。结果显示,当外引物与内引物浓度比为200nmol/L∶2 400nmol/L(1∶12)、Bst DNA聚合酶浓度为0.64 U/μL、Mg2+浓度为2.5 mmol/L、dNTP浓度为1.0mmol/L,在恒温(60℃)条件下作用60min,扩增效果出现明显"梯状"条带,同时对建立的RT-LAMP检测方法进行特异性和敏感性验证,其只有PoRV获得特异性扩增条带,与其他猪流行性腹泻病毒、猪传染性胃肠炎病毒、猪瘟病毒等无交叉反应,具有良好的特异性,最低检测分子拷贝数为1.0×102拷贝/μL,具有极高的敏感性。反应结束后肉眼可见阳性扩增产物出现白色沉淀,加入SYBR GreenⅠ观察颜色变化可以判定结果。该方法适用于野外、基层部门和海关快速检测PoRV的新方法,在临床上有良好的推广意义。     

仙台病毒RT-LAMP可视化检测方法的建立

目的建立一种快捷、灵敏的检测方法,即反转录-环介导等温扩增方(RT-LAMP)用于仙台病毒(SeV)的检测。方法根据Gen Bank公布的SeV序列(DQ219803.1),在其保守区域设计了六套LAMP引物,利用LAMP Real-Time Turbidimeter LA-320C仪监测反应进程并筛选最佳引物、反应条件,建立对SeV核酸进行特异性扩增的RT-LAMP检测方法,并可通过加入目测荧光检测试剂肉眼判断结果。对所建立的方法进行了敏感性、特异性评估并对92份样品进行了检测。结果该方法在63℃恒温下作用60 min,SeV RNA获得了高效率的特异性扩增,与其余常见小鼠病毒无交叉反应;最低检出量为2.1TCID_(50) SeV,比RT-PCR方法高102倍;肉眼判断结果与RealTime Turbidimeter LA-320仪监测结果一致;通过对92份样品的RT-LAMP,RT-PCR和间接ELISA方法的检测比对,三者符合率为100%。结论建立的SV RT-LAMP检测方法具有快速、特异、灵敏,操作简单的特点,具有良好的应用前景。     

非洲马瘟病毒群特异性RT-PCR检测方法的研究

非洲马瘟病毒(African horse sickness virus,AHSV)为双股RNA病毒,感染所有马科动物.设计2对位于AHSV基因组S7片段的引物,经RT-PCR扩增,证实2对引物对6种血清型的AHSV RNA均有特异性扩增,且能对同属的蓝舌病病毒(BTV)、鹿出血热病毒(EHDV)进行区别诊断.经序列测定及Blast,证实所扩增的条带确为AHSV S7相应位置核苷酸序列,表明已初步建立AHSV群特异性RT-PCR检测方法.     

口蹄疫病毒RT-LAMP检测方法的建立

利用逆转录环介导等温核酸扩增技术(RT-LAMP),建立了口蹄疫病毒快速检测方法,同时评价了该方法的灵敏性和特异性。结果表明,根据口蹄疫病毒多聚蛋白基因保守区段设计的LAMP引物能够在65℃下,1 h内实现目标核酸区段的大量扩增,检测结果可直接用肉眼判断。该检测体系具有极高的特异性,只能检测到目标病毒,与其他类似病毒如猪水泡病病毒、猪瘟病毒、猪细小病毒等无交叉反应,可检测到10-5稀释度的目标病毒核酸量,比普通RT-PCR的灵敏性高100倍,比荧光PCR高10倍。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism