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1.
L-异亮氨酸产生菌选育的研究   总被引:6,自引:0,他引:6  
以黄色短杆菌(Brevibacteriumflavum)ATCC14067为出发菌株,经硫酸二乙酯(DES)、紫外线(UV)和亚硝基胍(NTG)逐级诱变处理,α-氨基-β-羟基戊酸(AHV)、S-2-氨基乙基-L-半胱氨酸(AEC)、磺胺胍(SG)、乙硫氨酸(Eth)、α-氨基丁酸(α-AB)、异亮氨酸氧肟酸(IleHx)等氨基酸结构类似物及琥珀酸为碳源平板定向筛选,获得一株L-异亮氨酸高产菌ZQ-4(AHV~γ、AEC~γ、SAM~γ、SG~γ、Eth~γ、α-AB~γ、IleHx~γ)在含13.5%葡萄糖培养基中,摇瓶发酵72h、L-异亮氨酸积累可达2.8-3.0%。  相似文献   

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应用ELISA和PCR法检测502例乙肝病人血清,401例HBsAg阳性血清中,有114例(28.4%)抗-HCV和HCVRNA双项阳性,25例(6.2%)HCVRNA单项阳性;21例(5.2%)抗-HCV单项阳性。将HBsAg乙肝病人分成HBVDNA,HBeAg阳性组和HBVDNA,HBeAg阴性组。前者抗-HCV阳性率为11.6%~20.5%,HCVRNA阳性率为16.2%~20.5%。后者抗-HCV阳性率为20.2%~55.6%,HCVRNA阳性率为23%~60.3%。结果说明长期携带HBV者和慢性乙肝病人均可重叠HCV感染。HBVDNA阳性组抗-HCV和HCVRNA阳性率明显高于HBVDNA阳性组  相似文献   

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用BamHI和HindII将丙肝病毒C+E1DNA片段从其克隆载体pGEM3zf-HCV/C+E1上切下,经Taq酶补齐3’末端后插入到载体pSVL-T中,构建成丙肝病毒C+E1真核表达载体pSVL-HCV/C+E1。本实验中重组效率达64.7%(11/17),正向插入为50%(2/4)。  相似文献   

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用丙肝病毒C+E1区真核表达质粒pcDNA-HCV/C+E1按400ug/只剂量免疫BALB/C小鼠,14周后同一剂量再加强免疫一次。加强免疫后2周,在50%PEG1450介导下将脾细胞与SP2/0小鼠骨髓瘤细胞(51)融合。实验结果融合率达54.3%(313/576)。阳性率为5.4%(17”313)。克隆化后得到6株稳定分泌抗丙肝病毒C区单克隆抗体杂交瘤细胞株。这6株杂交瘤均产生IgM抗体,接种BALB/C小鼠后产生腹水的效价为164-1320(ELISA)。  相似文献   

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对379例良、恶性肝组织进行的免疫组织化学研究显示,33%的慢性迁延性肝炎(6/18)、76%的慢性活动性肝炎(26/34)、92%的肝硬变(57/62)和97%的肝细胞性肝癌(HCC)(58/60)中有HBxAg表达,阳性率高于HBsAg或HBcAg。癌周肝中的HBxAg阳性率显著高于非癌周肝。与其它2种HBV抗原不同,HBxAg表达在细胞类型上有较明显的选择性,在肝小多角细胞(SPLC)、小细胞性不典型增生(SCD)及HCC中较强。与IGFⅡ、c-erbB-2、c-myc和EGF-R表达进行的对照研究表明HBxAg与IGFⅡ和c-erbB-2这2种HCC发生相关基因的表达关系密切。PCNA染色结果显示HBxAg阳性组织的细胞增殖活性显著高于HBxAg阴性组织。我们的结果还表明HBxAg表达与肝细胞不典型增生的发生和进展有关、提出HBVX基因可能通过其表达产物(HBxAg)首先激活IGFⅡ、c-erbB-2基因,继而引起显著的SPLC增生和SCD而参与HCC发生的.  相似文献   

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高产稳产聚羟基烷酸的重组大肠杆菌的构建   总被引:7,自引:0,他引:7  
重组大肠杆菌Escherichia coliHMS174(pTZ18UPHB) 含有携带聚羟基烷酸(PHA) 合成基因( phaCAB)** 的质粒pTZ18UPHB,是很有潜力的PHA 生产菌,但存在着质粒不稳定和不能合成3羟基丁酸(3HB) 与3羟基戊酸(3HV) 共聚物[P(3HBco3HV)] 的缺陷。将RK2 质粒上的par DE 基因引入pTZ18UPHB 构成质粒pJMC2 ,该质粒可以在宿主E.ColiHMS174 中稳定遗传。将培养基中的磷酸盐浓度降至18 m mol/L,发现E.Coli HMS174(pJMC2) 能够以丙酸为前体合成P(3HBco3HV) ,其中3HV 在共聚物中的含量为5 % ~8 % 。在5L自动发酵罐中分批补料培养E.Coli HMS174(pJMC2) ,培养基初始磷酸盐浓度为15 m mol/L,30 h 后每升培养液中干菌体可达42-5 g,P(3HBco3HV) 占干重的70 % ,其中3HV 在共聚物中的含量为4-9 % 。  相似文献   

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新型HCV EIA诊断试剂盒的研制   总被引:3,自引:0,他引:3  
杨永平  曹经缓 《病毒学报》1994,10(2):118-127
丙型肝炎病毒(HCV)基因组结构区核壳蛋白(C)区抗原、膜蛋白E1和E2区抗原,以及非结构区NS3-NS5区抗原的区段,已经在原核细胞中获得有效的表达。同时,相应区段中的优势抗原表位肽也经化学合成法大规模地制备。HCV基因组上各区段抗原性的分析发现,由C区和NS3区分别编码的C抗原和C33c抗原是HCV基因组上两个优势抗原区段。其相应的抗体出现早(感染后6周可检出抗C33c抗体),阳转率高(约99%阳性检出率),特异性和重复性均优于其它区段抗原。以中国人HCV的C33c重组蛋白和分支状合成肽MAP-C-19为复合抗原,研制了适合我国抗HCV抗体检测的新型丙型肝炎病毒酶免疫测定(HCVELA)诊断试剂盒。它同当代美国Abbott/UBIHCVELA诊断试剂的符合率约98%,同加拿大YES公司HCVEIA诊断试剂的符合率约97.8%,阳性检出率提高了约2%,3次重复性达100%,表明其特异性、敏感性和重复性均达到了当代第二代JCVELA诊断试剂的水平。我国人群中抗HCV抗体的分布情况为:正常人群的检出率1%-2%;外科类住院病人检出率约28.8%;肝炎患者抗HCV阳性率为34.4%,慢活肝、肝硬化和重症肝炎患者  相似文献   

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Metylomonassp.GYJ3菌的甲烷单加氧酶(MMO)粗酶提取液经DEAE-SepharoseCL-6B阴离子交换层析、SephadexG-100凝胶过滤层析和DEAE-TSKgelHPLC分离纯化出MMO还原酶组分.经HPLC分析,纯度大于95%,纯化倍数为4.4,加入至MMO羟基化酶和调节蛋白B的体系中表现比活为228nmol环氧丙烷每分钟毫克蛋白.SDS-PAGE电泳表明还原酶由一种亚基组成,分子量42kD.ICP-AES测定还原酶的Fe含量为1.83molFe每mol蛋白.UV-Vis光谱表明还原酶除280nm蛋白质特征峰外在460nm有最大吸收峰,且A280nm/A460nm为2.50,与其它黄素一铁硫蛋白相似,推测还原酶可能含一个FAD辅基和Fe2S2中心.在厌氧条件下,还原酶能够和NADH作用,UV-Vis光谱分析表明还原酶460nm处特征吸收峰消失,说明在MMO催化过程中还原酶接受NADH的电子.DEAE-SepharoseCL-6B阴离子交换层析分离出调节蛋白B,部分纯化的调节蛋白B的分子量大约在20kD,它能够提高MMO比活性40倍,MMO还原酶和调节蛋白B单独存在时不具有MMO  相似文献   

9.
P~(53) PROTEIN OVEREXPRESSION IN PREMALIGNANT AND MALIGNANT LESIONS OF ORAL MUCOSA:IMMUNOHISTOCHEMICAL OBSERVATIONP~(53)PROTEI...  相似文献   

10.
病毒性肝炎HAV,HBV,HCV,HDV和HEV重叠感染的研究   总被引:1,自引:0,他引:1  
采用ELISA法检测了108例乙型肝炎病毒(HBV)感染者血清中的五种肝炎病毒──甲型(HAV)、乙型(HBV)、丙型(HCV)、丁型(HDV)和成型(HEV)肝炎病毒的标志物,并采用PCR技术检测了患者血清HBVDNA、HCVRNA及HDVRNA。结果五种肝炎病毒重叠感染者35例(32.4%),单纯HBV感染者73例(67.6%)。HBV、HAVM重感染率为4.6%,HBV、HCV二重感染率为9.2%,HBV、HDVM重感染率为14.8%,HBV、HEV二重感染率为1.9%,HBV、HCV和HDV三重感  相似文献   

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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.  相似文献   

16.
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  相似文献   

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