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1.
We report here the adoptive transfer, to patients with metastatic melanoma, of highly selected tumor-reactive T cells directed against overexpressed self-derived differentiation antigens after a nonmyeloablative conditioning regimen. This approach resulted in the persistent clonal repopulation of T cells in those cancer patients, with the transferred cells proliferating in vivo, displaying functional activity, and trafficking to tumor sites. This led to regression of the patients' metastatic melanoma as well as to the onset of autoimmune melanocyte destruction. This approach presents new possibilities for the treatment of patients with cancer as well as patients with human immunodeficiency virus-related acquired immunodeficiency syndrome and other infectious diseases.  相似文献   

2.
基因工程化食品安全性在我国还是个新论题,文中从生物体内细胞的基因所含有的控制信息多重性和复杂性的角度,论述对控制信息结构及作用的困难性和局限性,论证了基因重组引起遗传基因变异的可能性,并通过实例,进一步证实遗传基因变异及控制给人类带来的危害,启发人们对基因工程化食品安全性加以关注。  相似文献   

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4.
A liquid crystal system was used for the fabrication of a highly ordered composite material from genetically engineered M13 bacteriophage and zinc sulfide (ZnS) nanocrystals. The bacteriophage, which formed the basis of the self-ordering system, were selected to have a specific recognition moiety for ZnS crystal surfaces. The bacteriophage were coupled with ZnS solution precursors and spontaneously evolved a self-supporting hybrid film material that was ordered at the nanoscale and at the micrometer scale into approximately 72-micrometer domains, which were continuous over a centimeter length scale. In addition, suspensions were prepared in which the lyotropic liquid crystalline phase behavior of the hybrid material was controlled by solvent concentration and by the use of a magnetic field.  相似文献   

5.
从1994年到现在,全世界转基因作物的种植生产和消费已经超过20年。转基因作物刚开始出现便立即被农民所接受。单单在2013年,全世界范围内包括棉花、玉米、大豆、油菜、甜菜和苜蓿在内的转基因作物种植面积已高达1.75亿hm2,有14个国家的转基因作物种植面积超过50万hm2。绝大多数转基因作物的两个典型优点是抗除草剂和抗虫。主要生产国的转基因作物普及率已经达到90%。如今,转基因作物在发达国家的种植面积比发展中国家更大。截至目前,还没有关于人类消费转基因作物以及含转基因成分食品的数据统计,绝大部分(约90%)的主要转基因作物被用作动物饲料,少数转基因作物,如木瓜、南瓜及甜玉米则被直接消费,油、淀粉、高果糖甜味剂、蔗糖和卵磷脂等来源于转基因作物的原料普遍被应用于食品产业。在美国超市,高达70%的产品中含有转基因成分,很多其他国家的人们也在消费这样的产品,尤其是那些没有要求转基因标识的国家和地区。在许多国家,一些非政府组织经常散布关于转基因食物的谣言,以达到阻挠公众接受转基因食物和转基因作物商业化的目的。遗憾的是,政府决策者的决定常常基于政治考虑,而非出于转基因作物的重要科学意义。  相似文献   

6.
The ecological risks and benefits of genetically engineered plants   总被引:2,自引:0,他引:2  
Discussions of the environmental risks and benefits of adopting genetically engineered organisms are highly polarized between pro- and anti-biotechnology groups, but the current state of our knowledge is frequently overlooked in this debate. A review of existing scientific literature reveals that key experiments on both the environmental risks and benefits are lacking. The complexity of ecological systems presents considerable challenges for experiments to assess the risks and benefits and inevitable uncertainties of genetically engineered plants. Collectively, existing studies emphasize that these can vary spatially, temporally, and according to the trait and cultivar modified.  相似文献   

7.
环境生物修复中高效基因工程菌的构建策略   总被引:16,自引:0,他引:16       下载免费PDF全文
通过对环境污染物的生物降解机制及妨碍污染物降解的因素进行分析,提出了几种高效基因工程降解菌的构建策略,包括重组污染物降解基因以优化污染物降解途径、重组污染物摄入相关基因以改善对污染物的生物可利用性和重组环境不利因子抵抗基因以增强其环境适应性等.  相似文献   

8.
A recombinant gene encoding human growth hormone (hGH) was stably introduced into cultured myoblasts with a retroviral vector. After injection of genetically engineered myoblasts into mouse muscle, hGH could be detected in serum for 3 months. The fate of injected myoblasts was assessed by coinfecting the cells with two retroviral vectors, one encoding hGH and the other encoding beta-galactosidase from Escherichia coli. These results provide evidence that myoblasts, which can fuse into preexisting multinucleated myofibers that are vascularized and innervated, may be advantageous as vehicles for systemic delivery of recombinant proteins.  相似文献   

9.
In a variety of human genetic diseases, replacement of the absent or defective protein provides significant therapeutic benefits. As a model for a somatic cell gene therapy system, cultured murine fibroblasts were transfected with a human growth hormone (hGH) fusion gene and cells from one of the resulting clonal lines were subsequently implanted into various locations in mice. Such implants synthesized and secreted hGH, which was detectable in the serum. The function of the implants depended on their location and size, and on the histocompatibility of the donor cells with their recipients. The expression of hGH could be modified by addition of regulatory effectors, and, with appropriate immunosuppression, the implants survived for more than 3 months. This approach to gene therapy, here termed "transkaryotic implantation," is potentially applicable to many genetic diseases in that the transfected cell line can be extensively characterized prior to implantation, several anatomical sites are suitable for implantation, and regulated expression of the gene of therapeutic interest can be obtained.  相似文献   

10.
Social policies are used to regulate how members of a society interact and share resources. If we expand our sense of community to include the ecosystem of which we are a part, we begin to develop an ethical obligation to this broader community. This ethic recognizes that the environment has intrinsic value, and each of us, as members of society, are ethically bound to preserve its sustainability. In assessing the environmental risks of new agricultural methods and technologies, society should not freely trade economic gains for ecological damage, but rather seek practices that are compatible with ecosystem health. This approach is used to evaluate the environmental risks associated with genetically engineered insect-resistant trees. The use of insect-resistant trees is a biologically based pest control strategy that has several advantages over pesticide use. However, the use of genetically engineered trees presents particular ecological concerns because the trees are long lived and often are not highly domesticated. The main environmental concerns reviewed include: (1) adaptation of pests to the trees, leading to a non-sustainable agricultural practice, (2) transgenic trees producing environmental toxins, (3) insect resistance enhancing the invasiveness of the tree, causing it to become weedy or invade wild habitats, and (4) transfer of the transgene to wild or feral relatives of the tree, possibly increasing the invasiveness of weeds or wild plants. Some methods are available to offset these risks; however, the environmental risks associated with this technology have been poorly researched and need to be more clearly identified so that when we evaluate the risks, it is based on the best information obtainable. To fulfil an ethical obligation to the environment, public policies and government regulations are needed to preserve the sustainability of both the environment and the future of our production systems. A better understanding of both the ecological issues and of genetic engineering in general are needed on the part of citizens and policy makers alike to ensure that sound environmental decisions are made. Otherwise, the environmental benefits of this technology, mainly decreasing the use of more toxic pesticides in tree crops and forests, will either be lost or traded for other environmental hazards.  相似文献   

11.
Malignant gliomas are the most common malignant brain tumors and are almost always fatal. A thymidine kinase-negative mutant of herpes simplex virus-1 (dlsptk) that is attenuated for neurovirulence was tested as a possible treatment for gliomas. In cell culture, dlsptk killed two long-term human glioma lines and three short-term human glioma cell populations. In nude mice with implanted subcutaneous and subrenal U87 human gliomas, intraneoplastic inoculation of dlsptk caused growth inhibition. In nude mice with intracranial U87 gliomas, intraneoplastic inoculation of dlsptk prolonged survival. Genetically engineered viruses such as dlsptk merit further evaluation as novel antineoplastic agents.  相似文献   

12.
基因工程牛生长激素高密度发酵表达的研究   总被引:3,自引:0,他引:3  
通过对重组牛生长激素基因工程大肠杆菌摇瓶和5、30 L发酵罐发酵表达的研究,建立了基因工程牛生长激素的高密度发酵表达工艺,菌体密度最高可达到OD550=120,rbIL-2的表达量占菌体总蛋白的20%以上.  相似文献   

13.
14.
A gene coding for the major histocompatibility antigen HLA-A2 was transferred into human HLA-A2 negative M1 cells and murine L cells. Following transfection, these cells expressed molecules at the cell surface that are biochemically indistinguishable from HLA-A2 antigens on the human cell line JY from which the HLA-A2 gene was isolated. The M1A2 cells were recognized and lysed by a cytolytic T-cell clone specific for HLA-A2. The transfected L cells which express HLA-A2 in association with human beta 2-microglobulin were not lysed by this T-cell clone. The specific cytolysis of M1A2 cells could be inhibited by monoclonal antibodies to HLA-A2, and monoclonal antibodies to T3, T8, and LFA-1 on cytotoxic T lymphocytes. These results suggest that killing by allospecific T cells requires HLA-A2 antigens as well as other species-specific structures on the target cell surface.  相似文献   

15.
Leukocyte adhesion deficiency (LAD) is an inherited disorder of leukocyte function caused by derangements in CD18 expression. The genetic and functional abnormalities in a lymphocyte cell line from a patient with LAD have been corrected by retrovirus-mediated transduction of a functional CD18 gene. Lymphocytes from patients with LAD were exposed to CD18-expressing retrovirus and enriched for cells that express CD11a and CD18 (LFA-1) on the cell surface. Molecular and functional analyses of these cells revealed (i) one copy of proviral sequence per cell, (ii) viral-directed CD18 RNA that exceeded normal endogenous levels, (iii) normal quantities of CD11a and CD18 protein on the cell surface, and (iv) reconstitution of LFA-1-dependent adhesive function.  相似文献   

16.
Tissue from normal rat livers was grafted onto the livers of rats that were genetically deficient in bilirubin uridine diphosphate glucuronyltransferase activity. Twelve weeks after the grafting operation, the liver of the recipient rats had bilirubin uridine diphosphate glucuronyltransferase activity.  相似文献   

17.
In experiments designed for the study of interactions in vitro between the cells of glioblastoma multiforme and lymphocytes from the same donor, a marked eosinophilic response was noted in three out of six cases. This was an entirely unexpected finding since few, if any, eosinophils survive in tissue cultures. These cells incorporated (3)H-cytidine and (3)H-leucine 72 hours after the cultures had been established, an indication that they were metabolically active.  相似文献   

18.
PCV2对体外培养仔猪淋巴细胞凋亡的影响   总被引:8,自引:1,他引:7  
选用4头猪圆环病毒2型(porcine circovirus 2,PCV2)血清抗体阴性的普通断奶仔猪,无菌取脾脏,分离淋巴细胞,分为对照组和试验组进行体外培养。试验组在培养体系中加入一定量的PCV2。分别在培养后的0、2、4、6、12、24、36和48h收获淋巴细胞。用电子显微镜、DNA琼脂糖凝胶电泳对细胞凋亡进行定性测定,用流式细胞术对细胞周期和细胞凋亡率进行定量测定,同时测定了凋亡相关蛋白半胱天冬酶3(Caspase-3)的表达情况。结果显示,PCV2作用后不同时间,DNA电泳均呈现出具细胞凋亡特征的梯形条带;电镜下出现细胞凋亡各期的形态学变化。从培养后4h开始,试验组淋巴细胞凋亡率均显著高于对照组(P〈0.05);而表示细胞增殖活性的增殖指数(PI),试验组在2、4、6、12和24h均比对照组显著下降(P〈0.05);表达Caspase-3的细胞百分率,除0h外,试验组均显著高于对照组(P〈0.05)。上述结果表明,PCV2能引起体外培养的仔猪淋巴细胞凋亡率增加,细胞增殖活性下降,且Caspase-3是PCV2诱导淋巴细胞凋亡的重要调节物。  相似文献   

19.
选用30只波尔山羊作供体,89只奶山羊作受体进行胚胎移植,采用LOGISTIC回归分析影响受体妊娠率的影响因素。结果表明:受体发情状况和移植方式对妊娠率产生决定性作用,胚胎发育阶段也会极显著影响妊娠率。LOGISTIC回归分析可有效的应用于繁殖类试验。  相似文献   

20.
无菌采取犬抗凝血,分离淋巴细胞并制备成不同浓度。应用正交试验,探讨不同浓度淋巴细胞、植物血凝素P(PHA-P)、犊牛血清(FCS)对淋巴细胞增殖的影响。在此基础上,研究不同浓度犬、猪转移因子(transferfactor,TF)对犬淋巴细胞增殖的影响,增殖的结果用MTT法测定。结果表明,当犬淋巴细胞浓度为5×106个/ml,PHA-P为12.5μg/ml,FCS为10%时,淋巴细胞增殖效果最佳。在最佳培养条件下,犬、猪TF浓度在0.195 ̄25mg/ml时,对淋巴细胞转化增殖均有促进作用,但犬、猪TF单独或与PHA-P共同作用时对淋巴细胞增殖的最佳刺激浓度均为1.56mg/ml,且犬、猪TF单独作用于淋巴细胞的效应明显优于与PHA-P的协同作用。结果证实,同源或异源TF对犬淋巴细胞增殖有良好的刺激效果,同时研究结果为异源TF在临床上应用于犬病毒性疾病的防治提供了实验依据。  相似文献   

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