共查询到19条相似文献，搜索用时 234 毫秒
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研究了小鼠艾氏腹水癌细胞在含有不同低温保护剂的玻璃化冻存液内，快速降温冷冻保存１－７ｄ后细胞超微结构和功能的变化。这种快速、简便的方法可应用于艾氏腹水癌细胞的深低温保存。 相似文献
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随着基因工程和畜牧学的结合,胚胎冷冻已经发展成为动物胚胎工程中一个重要的调控技术。自从Whittingham[1]在1972年首次报道了通过小鼠胚胎冷冻得到正常后代以来,已有13种其他哺乳动物胚胎冷冻获得成功。胚胎冷冻技术在有效保存(时间和花费)珍稀及突变物种资源,人类不孕治疗,家畜繁殖等方面有广泛的应用。我国也将胚胎冷冻和移植列入“八五”计划的重要项目。一,胚胎冷冻的原理和冷冻保护剂胚胎冷冻保存是采用特殊的保护措施和降温程序,使胚胎在-196℃条件下代谢停止,而升温后又能恢复代谢能力的一种长期保护胚胎的技术。冷冻保护剂可以改… 相似文献
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为探讨体外受精－胚胎移植（IVT－ET）过程中影响临床妊娠率的因素，对248个常规IVF－ET周期进行了分析，研究了夫妇年龄、穿刺卵泡数、获取卵母细胞数、卵母细胞成熟卵比率、卵母细胞空卵比率、精液精子质量和数量、授精前孵育时间、授精精子密度、受精率、多原核孕卵生成率、卵裂率、移植胚胎数目、胚胎累积评分及移植过程评分和临床妊娠之间的关系。结果表明，临床妊娠率与母方年龄呈显著性负相关（P＜0．05），与移植胚胎数目、胚胎累积评分和移植过程评分呈显著性正相关（P＜0．05）。说明母方年龄、移植胚胎数目、胚胎累积评分和移植过程评分是影响临床妊娠的重要因素。 相似文献
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本文探讨了HYA(透明质酸酶)的浓度和作用时间对牛体外成熟卵母细胞脱卵丘的影响,不同强度电脉冲 乙醇 6-DMAP对牛体外成熟卵母细胞的孤雌激活作用以及和乙醇 6-DMAP激活的比较.对电融合脉冲强度,脉冲次数进行了优化.结果表明:卵母细胞成熟培养22h,用0.20%HYA作用10min或0.50%HYA作用5min效果较好.在激活电压1.8kV/cm、20us/次、间隔1 s,脉冲次数为1次的条件下的激活效果较好,在此条件下与乙醇 6-DMAP激活相比较,孤雌激活胚胎的囊胚率分别为19.6%和26.9%,差异不显著. 相似文献
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阐述了蒙古马保种工作的意义,并总结了蒙古马保种观点、保种目标及其影响保种的因素等各环节,从而探讨了蒙古马保种的主要研究方案——基地活体保种技术、冷冻精液保种技术、冷冻胚胎保种技术、基因库保种技术、分子标记辅助保种技术等蒙古马保种技术措施. 相似文献
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Microinjection with ultra-fine glass capillaries is widely used to introduce cryoprotective agents and other foreign molecules into animal cells, oocytes, and embryos. The fragility of glass capillaries makes difficult the microinjection of fish eggs and embryos, which are usually protected by a hard outer shell, called the chorion. In this study, we introduce a new electromechanical approach, based on the electropiercing of fish eggs with a stationary needle electrode. The electropiercing setup consists of two asymmetric electrodes, including a μm-scaled nickel needle placed opposite to a mm-scaled planar counter-electrode. A fish egg is immersed in low-conductivity solution and positioned between the electrodes. Upon application of a short electric pulse of sufficient field strength, the chorion is electroporated and the egg is attracted to the needle electrode by positive dielectrophoresis. As a result, the hard chorion and the subjacent yolk membrane are impaled by the sharp electrode tip, thus providing direct access to the egg yolk plasma. Our experiments on early-stage medaka fish embryos showed the applicability of electro-microinjection to fish eggs measuring about 1 mm in diameter. We optimized the electropiercing of medaka eggs with respect to the field strength, pulse duration, and conductivity of bathing medium. We microscopically examined the injection of dye solution into egg yolk and the impact of electropiercing on embryos'' viability and development. We also analyzed the mechanisms of electropiercing in comparison with the conventional mechanical microinjection. The new electropiercing method has a high potential for automation, e.g., via integration into microfluidic devices, which would allow a large-scale microinjection of fish eggs for a variety of applications in basic research and aquaculture. 相似文献
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大鼠是研究人类疾病的理想模型动物,而利用核移植手段是创造遗传修饰大鼠的最佳手段。但由于大鼠卵母细胞和胚胎发育的特殊性,克隆大鼠一直没有取得成功。我们在对大鼠卵细胞活化进行了深入研究的基础上,采用了全新的快速一步法体细胞核移植技术,并且利用蛋白激酶抑制剂(MG132)阻断大鼠卵母细胞减数分裂中期到后期的转变,成功地创造出有繁殖能力的体细胞克隆大鼠。该项研究为人类疾病的研究、相关药物的研制创造了条件。 相似文献
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简单地说,异种移植是将器官、组织或细胞从一个物种的机体内取出,植入另一物种机体内的技术。异种移植一方面能为得不到同种供体器官的病人带来生的希望,另一方面又存在着给整个人类带来跨物种感染和毁灭性疫病流行的潜在风险。本文对这一近年来充满争议、比较危险的基因工程应用技术的科学上的不确定因素,以及所引发的伦理问题进行分析,尝试着为今后在我国开展异种移植伦理问题的研究做一些初步的问题清理工作。 相似文献
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Kirejczyk M 《Social studies of science》1999,29(6):889-912
Twenty years ago, the technology of in vitro fertilization created a new artefact: the human embryo outside the woman's body. In many countries, political debates developed around the artefact. One of the central questions in these debates is whether it is permissible to use human embryos in research and, if so, under what conditions. To date, no uniform answer to this question has been given by the governments and parliaments of the different nation states. This highlights the importance of national cultures and local dynamics in the process of crafting the space for human embryo research. In this paper I approach the issue of the national context by comparing the Dutch and British parliamentary debates on human embryos. Though some arguments used in both debates were similar, the outcomes were very different. In the UK, the Human Fertilisation and Embryology Act was passed in 1990. In the Netherlands, several bills on human embryos have been drafted, but each of them was withdrawn from the proceedings before reaching Parliament. To understand the processes which led to these different outcomes, I scrutinize the roles in the Netherlands of the political parties, of the scientists' lobby and of women speakers, and compare them with the findings of the UK debate. I also reflect upon the role played by gender in these two culturally different political contexts. 相似文献
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This article discusses xenotransplantation (XTP: the surgical role of nonhuman tissues, organs, and cells for human transplantation) and examines the way its scientific promoters have defended their technology against potentially damaging public representations. The authors explore the criteria used to legitimate the selection of the pig as the best species from which to "harvest" transplant tissues in the future. The authors' analysis shows that scientists and medical practitioners routinely switch between scientific and cultural repertoires. These repertoires enable such actors to exchange expert identities in scientific discourse for public identities in cultural discourse. These discourses map onto similarities and differences between animal donors and human hosts. Finally, the case is used to comment on a number of related approaches where the dynamics of medical and scientific authority are discussed. 相似文献
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New forms of life produced by biomedical research, such as human embryonic stem cells (hESC), have been the object of public debate beyond the scientific fields involved. This article brings to light the case of Brazil, where recently passed federal legislation has authorized research with in vitro human embryos. It focuses on the legislative debate in the Brazilian National Congress between 2003 and 2005 on the Biosafety Bill of Law, which cleared for hESC research a certain share of supernumerary and unviable human embryos frozen in the country's assisted reproduction clinics. The passing of this Bill triggered other public reactions, chiefly a Direct Action of Unconstitutionality in Brazil's Federal Supreme Court. This study adopts an anthropological perspective for describing and analyzing the chief arguments in both debates, in terms of how the notion of 'life' was deployed and negotiated by contending parties. If, on the one hand, the definition of life appeared firmly attached to a conception of both the in vitro embryo and the fetus as a human person, on the other a movement towards breaking down life along utilitarian lines was found when the potential beneficiaries of stem cell therapy came into the equation. In all cases, however, notions of life were negotiated from a hybrid continuum of (biological) facts and (religious, moral and juridical) values, and resonated in different ways with the idea of the individual as privileged mode of constructing personhood in the context of modern nation states. 相似文献