首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
将将城疫病毒(NDV)F48E8株融合蛋白基因导入鸡痘病毒(FPV)插入载体pEGF1175-1的P7.5启动子下游,得到转移载体pFG1175-1重组质粒。采用脂质体转染技术,将该质粒转染FPV282E株感染的鸡胚成纤维细胞(CEF)。,经过多次蓝斑筛选纯化,获稳定的重组病毒rFPV-NDF。间接免疫荧光试验表明,rFPV-NDF感染的CEF中表达了NDV的融合蛋白。用rFPV-NDF免疫的SF  相似文献   

2.
禽呼肠孤病毒变异株的分离鉴定   总被引:5,自引:0,他引:5  
从病鸡肝分离到一株病毒,经电镜检查、理化特性分析、核酸电泳和中和试验等证明它为禽呼肠孤病毒(ARV)。该病毒只在鸡胚肝细胞(CELi)上产生细胞病变(CPE),在鸡胚成纤维细胞(CEF)和V_(ero)细胞上不增殖,它对热无敏感,Mg ̄(2+)不能增强其对热的稳定性,其基因组中的4个小节段的迁移率与ARVFDO和S_(1133)株明显不同,表明它是不同于FDO和S_(1133)的ARV变异株。  相似文献   

3.
应用聚合酶链反应技术,用设计带有限制性酶切位点的引物,特异地扩增从起始密码子开始的1 .8 kb 新城疫病毒( N D V) 血凝素神经氨酸酶( H N) 基因开放式阅读框,然后插入p T K2 B 的 Nhe Ⅰ位点,构建了含 N D V H N 基因的插入载体p T K H N1 和p T K H N2 ,再与感染火鸡疱疹病毒( H V T) 细胞的总 D N A 共转染鸡胚成纤维细胞( C E F) ,经有限稀释法和 Dotblot 筛选,得到含有 H N 基因的重组体r H V T1 和r H V T2 。经组织培养传代和 Western blot 分析,表明重组体在感染细胞中表达了 H N 蛋白。重组体在 C E F 上的生长特性与亲本病毒相同,且在连续传代过程中保持稳定。为国内新城疫基因工程疫苗研制奠定了基础。  相似文献   

4.
为了提高人睫状神经营养因子(CNTF)的生物学活性,用PCR方法获取N端缺失14个氨基酸的CNTF基因片段,经酶切鉴定、核酸测序证实突变体的核苷酸序列,将其重组至表达质粒pBV220,构建了CNTF突变体表达载体pBV-CNTFΔ.用SDS-PAGE测定其表达水平,鸡胚背根节无血清培养法检测表达蛋白的生物学活性.结果表明,pBV-CNTFΔ能表达生物学活性高于天然CNTF的约26kD蛋白质,表达水平达30%.为今后通过基因工程方法获得CNTF突变体,从而制备高效的CNTF制剂创造了条件.  相似文献   

5.
睫状神经营养因子的研究进展   总被引:3,自引:0,他引:3  
睫状神经营养因子 (CiliaryNeurotrophicFac tor ,CNTF )最初是从鸡胚的眼组织睫状节中提取出来 ,因对睫状节神经元有营养作用并可维持鸡副交感神经节的存活而得名[1~ 3] 。CNTF属神经调节细胞因子家族中的一员 ,但不属于神经营养因子家族成员。至今 ,已发现CNTF具有广泛的生物学活性 ,如它对于感觉和运动神经元的分化、存活及功能维持均具有重要作用[1,4 ] 。本文就CNTF的结构、分布、生物学效应及其与脊髓损伤修复的关系作一综述。1.CNTF及其基因结构1 1 CNTF的结构CNTF最初由H…  相似文献   

6.
在克隆和鉴定新城疫病毒(NDV)F48E8株血凝素-神经氨酸酶(HN)基因的基础上,应用分子克隆技术将HN基因导入鸡痘病毒插入载体pFG1175-1中启动子P7.5的下游,得到携带NDV-HN基因的质粒pFGHN1175-1。将此质粒pFGHN1175-1以脂质体转染中国鸡痘病毒疫苗株282E4株感染3 ̄4h的鸡胚成纤维细胞,采用蓝斑筛选方法纯化3次,得到稳定的重组鸡痘病毒。用NDV-HN基因特异  相似文献   

7.
鸡GnRH对体外培养的鸡卵泡膜细胞合成甾类激素的作用   总被引:1,自引:0,他引:1  
在建立鸡卵泡膜细胞体外无血清贴壁培养模型基础上,研究了鸡促性腺激素释放激素(cGnRHⅡ)对鸡卵胞膜细胞合成睾酮(T)和雌二醇(E2)的直接作用;以及在绵羊促黄体激素(oLH)或促卵泡激素(oFSH)存在时,cGnHⅡ对膜细胞合成T或E2的影响。实验结果如下:①在培养液中单独加入cGnRHⅡ,能促进F5、F3卵泡膜细胞合成T及E2,并具有剂量依赖关系;而对于F1卵泡膜细胞的作用效果不明显。②cGnRHⅡ与oLH(50ng)共同处理,当cGnRHⅡ低剂量(100g)时,膜细胞T合成量明显增加,而加大剂量时,T合成量则显著降低。③cGnRHⅡ(500ng)与oFSH(50ng)共同处理对膜细胞E2的合成有抑制作用,降低cGnRHⅡ的含量,可逐渐恢复oFSH对膜细胞E2合成的刺激作用。  相似文献   

8.
手术或屠宰采取措囊胚(B)、扩张囊胚(EB)。孵出囊胚(HB),置于含10%FCS的GIT液中进行42℃水浴10分钟的热应激和-7℃酒精糟10分钟的低温感受试验。结果,热应激对猪胚的存活率及发育率均无影响(P>0.05);而热应激提高了猪胚对低温的耐受程度,热应激的胚胎再经低温感受试验后,培养24小时的EB(φ<50)、EB(φ≥50)和HB的活细胞数分别较相应的对照组提高35.5%、41.3%和51.1%,差异显著(P<0.05),但在热应激处理液中添加了蛋白合成抑制剂者没有产生这一效果,此结果证明,热应激很可能诱发猪胚内产生抗低温的应激蛋白质,这为进一步研究猪胚胎冷冻和改进猪胚冷冻前处理提供了依据和可能途径。  相似文献   

9.
rhCNTF对鸡胚感觉与运动神经元神经营养作用的比较   总被引:4,自引:0,他引:4  
在无血清培养条件下,观察了重组人睫状营养因子(rhCNTF)对鸡胚背根节感觉神经元及腹角运动神经元的营养作用。结果表明rhCNTF对这两类神经元均有明显的促存活作用,并呈一定的剂量/效应关系。rhCNTF浓度在0.5ng/ml以下时无作用,1.0-1.5ng/ml时已有促神经元存活作用,4ng/ml时作用最明显,再增加到100ng/ml神经元存活数无进一步增加。比较培养7天时两类神经元存活数发现感觉神经元对CNTF缺乏的敏感性高于运动神经元,提示CNTF对运动神经元的促存活作用只是它多种类型神经元营养作用中较弱的一环  相似文献   

10.
云南松成熟胚的体细胞胚胎的发生研究   总被引:10,自引:0,他引:10  
云南松(Pinus yunnanesis Franch)是我国特产的一种优良森林树种。本研究采用云南松成熟合子胚为起始外植体,在含2,4-D10mg/L,KT和BA各4mg/L的改良P6培养基上得到胚发生培养物。将白色半透明的胚性愈伤组织(含早期原胚)在含2,4-D1.0mg/L,KT和BA各0.4mg/L的培养基上保持并增殖。在附加9,000mg/L肌醇的高渗培养基(含NAA0.5mg/L,KT  相似文献   

11.
Transfer of cell-mediated immunity was achieved with dialyzable cell-free extracts from lymphoid cells of mice primed to the contact sensitizing agent, 2,4-dinitrofluorobenzene (DNFB). The biological activity of the extract (Transfer Factor, TF) was analyzed in vivo by the ear thickness assay and in vitro by the macrophage migration inhibition (MMI) test and lymphocyte transformation using the soluble analog, sodium 2,4-dinitrobenzenesulfonate. Consistently positive responses occurred 20 hr following a single intravenous injection of 5 × 107 lymphocyte equivalents per recipient. The most potent source of TF (memory TF) was lymph node cells obtained 30 days after primary exposure to DNFB. By contrast TF prepared at the peak of the response to DNFB was less potent which was shown to be due to the presence in it of a suppressor factor. Memory TF elicited macrophage inhibition factor production in naive lymph node cells whereas positive responses were only obtained in the ear thickness and lymphocyte transformation assays provided recipients had undergone prior subliminal sensitization. Specificity of TF was tested using picryl chloride and oxazolone as control antigens. Results from the MMI and ear thickness assays were consistent with the presence in Transfer Factor of an antigen-specific component. Its effects, however, on the proliferative response to antigen lacked specificity and depended on prior sensitization of recipients, rather than donors, to the inducing antigen. The target of the specific component was considered to be an Ly-1+, Ia?, Ly23? T cell since MIF production and in vivo delayed hypersensitivity are known to be mediated by a T cell bearing this phenotype. Taken together these findings emphasize the value of using a battery of tests of cell-mediated immune function when studying soluble mediators such as Transfer Factor and suggest that the current system is a valid experimental model for analysis of the Transfer Factor phenomenon.  相似文献   

12.
Transfer Factor is a dialysable moiety obtained from immune lymphocytes. It has been successfully used for the treatment of several viral infections including labial and genital herpes. In the present study, thirty-three patients with low immune response to HSV antigens and suffering from herpes ocular infections were orally treated with HSV-specific transfer factor (TF). Their relapse index was reduced from 20.1 before treatment to 0.51 after TF administration, with only 6/33 patients relapsing. Although this is not a placebo-controlled-randomized study, the results suggest that TF specific for HSV antigens may be efficacious for preventing relapses of ocular herpes infections as has been the case with genital and labial localisations.Abbreviations CMI Cell-mediated immunity - CMV Cytomegalo-virus - EBV Epstein-Barr virus - HIV Human immunodeficiency virus - HK Herpes keratitis - HSV Herpes simplex virus - IRI Individual relapse index - KU Kerato-uveitis - LMT Leucocyte migration test - LST Lymphocyte stimulation test - MIF Migration inhibition factor - RHK Relapsing herpes keratitis - TF Transfer factor  相似文献   

13.
Transfer Factor (TF) was used in a placebo controlled pilot study of 20 patients with chronic fatigue syndrome (CFS). Efficacy of the treatment was evaluated by clinical monitoring and testing for antibodies to Epstein-Barr virus (EBV) and human herpes virus-6 (HHV-6). Of the 20 patients in the placebo-controlled trial, improvement was observed in 12 patients, generally within 3-6 weeks of beginning treatment. Herpes virus serology seldom correlated with clinical response. This study provided experience with oral TF, useful in designing a larger placebo-controlled clinical trial.  相似文献   

14.
Multistep syntheses of substituted benzenes and benzoquinone inhibitors of tissue Factor VIIa are reported. The benzene analogues were designed such that their substitution pattern would occupy and interact with the S(1), S(2), and S(3) pockets of the tissue Factor VIIa (TF/VIIa) enzyme. The compounds exhibited modest potency on TF/VIIa with selectivity over Factor Xa and thrombin. The X-ray crystal structures of the targeted fluorobenzene 12a and benzoquinone 14 inhibitors bound to TF/VIIa were obtained and will be described.  相似文献   

15.
Tissue Factor (TF) is the initiator of coagulation and Tissue Factor Inhibitor (TFPI) is the physiological inhibitor of the TF/FVIIa complex. Circulating levels of TF and TFPI were quantified in dengue patients and the relationships with disease severity and infecting serotype analysed. A significant decrease in TF and TPFI plasma levels was observed in mild DF patients compared with severe dengue. Furthermore, both factors were associated with haemorrhagic manifestations. Finally, TF levels were significantly increased in DENV-1/2 infected patients as compared with DENV-4. These findings suggest that activation of TF-pathway is an important component of DENV -related coagulation disorders.  相似文献   

16.
郭宝福  郭鑫 《生物技术》1993,3(3):25-28
本文报道了在国内首次用转移因子制剂治疗奶牛隐性乳房炎的效果。我们采用的转移因子制剂是本单位从健康猪脾细胞提取的,经按人用转移因子制检规程检测达到要求后,用于本省西部、东部和郊区三个奶牛场计159头患隐性乳房炎的奶牛,每天一次肌注,连续用药5次,测定用药前后的客观指标(CMT、BTB、苛性钠及氯化物凝乳试验等),以痊愈、显效、好转及无效等判定标准,经统计学处理后看出,用药后与用药前比较,差异非常显著(P<0.01),治疗组的有效率为91.2%,看出了应用转移因子治疗奶牛隐性乳房炎具有明显的治疗效果。  相似文献   

17.
Summary 26 breast cancer patients with recurrent disease were studied in order to evaluate whether transfer factor (TF) could abrogate serum blocking factors (SBF) and transfer or amplify immune reactivity directed to tumor-associated antigens (TAA) by using the leukocyte adherence inhibition assay (LAI). When 11 leukocyte samples obtained from patients reactive to cancer extract were preincubated with autologous blocking sera in the presence of PBS, nonspecific TF, or specific TF, leukocytes from these patients gained reactivity against breast cancer extract in none out of 11, one out of 11, and nine out of 11 experiments, respectively. Specific TF was obtained from donors with positive LAI breast cancer extract. Mean percentage LAI differences between control extract and breast cancer extract were –4.5±2.6, 0.5±1.7, and 15.5±2.4. The results of specific TF were significantly different from those of nonspecific TF (P<0.005).When nine leukocyte samples obtained from patients unreactive to cancer extract were preincubated with autologous blocking sera in the presence of PBS, nonspecific TF, or specific TF, leukocytes from these patients gained reactivity against breast cancer extract in none out of nine, one out of nine, and seven out of nine experiments, respectively. Mean percentage LAI differences between control extract and breast cancer extract were –4.6±2.0, 0.6±2.3, and 11.8±3.5. The results of specific TF were again significantly different from those of nonspecific TF (P<0.005).When allogeneic blocking sera were utilized, similar results were obtained. When specific TF was administered in two doses, 1 week apart subcutaneously to six breast cancer patients who were unreactive to breast cancer extracts, four patients gained reactivity against breast cancer extracts.Our in vitro experiments support the presence of a specific component in transfer factor extract which can transfer or amplify cell-mediated reactivity with abrogation of SBF directed at TAA.Abbreviations BSS = Balanced Salt Solution - LAI = Leukocyte Adherence Inhibition - PBS = Phosphate Buffered Saline - RPMI = Roswell Park Memorial Institute - SBF = Serum Blocking Factors - TAA = Tumor Associated Antigen - TF = Transfer Factor  相似文献   

18.
Structure-based drug design coupled with polymer-assisted solution-phase library synthesis was utilized to develop a series of pyrazinone inhibitors of the tissue factor/Factor VIIa complex. The crystal structure of a tri-peptide ketothiazole complexed with TF/VIIa was utilized in a docking experiment that identified a benzyl-substituted pyrazinone as a P(2) surrogate for the tri-peptide. A 5-step PASP library synthesis of these aryl-substituted pyrazinones was developed. The sequence allows for attachment of a variety of P(1) and P(3) moieties, which led to synthesis pyrazinone 23. Compound 23 exhibited 16 nM IC(50) against TF/VIIa with >6250x selectivity versus Factor Xa and thrombin. This potent and highly selective inhibitor of TF/VIIa was chosen for pre-clinical intravenous proof-of-concept studies to demonstrate the separation between antithrombotic efficacy and bleeding side effects in a primate model of thrombosis.  相似文献   

19.
20.
Human T lymphocytes become glucocorticoid-sensitive upon immune activation   总被引:1,自引:0,他引:1  
A murine model for Transfer Factor (TF) was used in an attempt to identify the nature of its antigen-specific component. TF was prepared from lymph node cells of CBA/Ca/T6 mice sensitized 30 days previously with 2,4-dinitrofluorobenzene (DNFB). To assay for the specific component of TF, 2 × 107 lymphocyte equivalents were injected intravenously into normal syngeneic recipients. Lymph node cells obtained 18–24 hr later gave a positive response in the macrophage migration inhibition (MMI) test in the presence of the soluble analog of DNFB (sodium 2,4-dinitrobenzenesulfonate). The activity of TF was abrogated by absorption with anti-Ia sera including both an Ia alloantiserum (A.TH anti-A.TL) and a xenogeneic rabbit anti-serum which exclusively recognizes carbohydrate-defined Ia antigens. Analysis by paper chromatography using the technique for purification of carbohydrate-defined Ia antigens revealed that MIF production was obtained exclusively with those fractions known to contain Ia antigenic activity. In addition, pretreatment of TF with insoluble conconavalin A (Con A) which has an affinity for carbohydrate-defined Ia antigens resulted in removal of its activity. Taken together these findings pointed to the presence in TF of I-region gene products. Absorption with antibody directed against the dinitrophenyl determinant abolished the capacity of TF to stimulate macrophage inhibition factor production suggesting that it might also contain antigen fragments possibly in association with Ia. No evidence was, however, obtained for H-2 restriction of the action of TF in vivo since it was found to exert an effect in a variety of strain combinations including A.TH and Balb/c which share no known common I-region specificities. Parallel experiments were carried out with the lymphocyte transformation assay since this is known to be a measure of the nonspecific components in TF. Pretreatment with mouse allo-anti-Iak serum directed against both protein-and carbohydrate-defined Ia antigens caused a partial reduction in the proliferative response. In contrast no change in response was observed when the TF was absorbed with insoluble Con A or anti-DNP serum. Furthermore, lymphocyte transformation was obtained with only one of the three paper chromatography fractions positive in the MMI assay as well as two other different fractions. Taken together, these findings permitted a distinction to be made between specific and nonspecific components of TF and indicated that the specificity of TF could be explained in terms of the presence of I-region gene coded products possibly in association with antigen fragments.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号