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【目的】获得转EGFP基因神经干细胞并监测其自我更新、增殖和多向分化潜能;通过用EGFP对神经干细胞进行标记和体外追踪实验,为EGFP作为示踪标记对神经干细胞进行体内移植研究奠定基础。【方法】利用神经干细胞培养技术体系,从胎龄30 d猪胎儿脑组织中分离培养神经干细胞,通过脂质体介导转染技术,将EGFP基因导入神经干细胞,诱导转基因神经干细胞贴壁分化,观察其体外增殖、分化特点。采用RT-PCR技术检测干细胞和分化细胞表面标志或相关基因。【结果】成功分离培养出神经干细胞,获得转EGFP基因神经干细胞,神经干细胞在表达EGFP的同时仍具有多向分化潜能。神经干细胞中Nestin表达强阳性,NogoA、DCX、CyclinD2、CD133、Hes1、Oct4、CD-90、Nanog和Sox2表达阳性;体外诱导的神经干细胞可以分化为星形胶质细胞(表达GFAP)、少突胶质细胞(表达GalC)和神经元细胞(表达NF、NSE和MAP2);能分化为脂肪细胞(表达LPL和PPARγ-D)、成骨细胞(表达Osteonectin和Osteocalcin)、肌细胞(表达myf-5、myf-6和myoD)、内皮细胞(表达CD31、CD34、CD144和eNOS)和软骨细胞(表达COL2A1)。【结论】从猪胎儿大脑组织分离神经干细胞具有可行性和有效性,转EGFP基因神经干细胞具有自我更新、增殖和多向分化潜能,可以用EGFP对神经干细胞进行标记、追踪,作为示踪标记进行神经干细胞体内移植研究。 相似文献
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干细胞及其在人类医学上的应用前景 总被引：1，自引：0，他引：1
干细胞是指从胚胎、胎儿或成年个体各种组织中分离出来的多能性细胞 ,具有体外保持未分化状态的无限增殖能力 ,在不同条件下可诱导分化为不同的细胞类型、组织甚至器官。胚胎癌细胞、胚胎干细胞、胚胎生殖细胞和成年组织干细胞是目前研究的几类主要干细胞 ,它们除作为发育生物学研究的细胞模型外 ,在人类医学领域也具有潜在的应用价值 相似文献
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哺乳动物胚胎干细胞一般可从胚胎囊胚内细胞团分离得到 ,具有在体外保持不分化的无限增殖能力 ,在合适的培养条件下 ,胚胎干细胞可定向诱导分化形成多种细胞类型。人们对胚胎干细胞进行体外培养与定向分化可以得到大量同源细胞 ,以应用于患疾病的细胞或器官移植治疗等研究。文章概述了胚胎干细胞增殖与分化的信号调节机制、诱导分化方法 ,国内外研究概况及展望 4个方面的内容 相似文献
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最近,由于干细胞研究普遍取得的令人鼓舞的进展以及干细胞分离、培养、移植等新技术方法的出现和发展,出生后雄性个体的生殖系干细胞———精原干细胞(spermatogonialstemcell,SSC)已成为一个愈加引人瞩目的课题。SSC位于睾丸曲细精管基膜上,既具有自增殖(self-renewal)潜能和定向分化潜能,又是自然状态下出生后个体内在整个生命期间能够进行自增殖并能将基因传递至子代的惟一成体干细胞。了解干细胞增殖与分化的调节机制,获得足够数量的种子细胞一直是所有干细胞研究共同面临的迫切问题之一。近年来,借助于SSCs移植技术这一功能性检测方法,国内外学者就SSCs体外培养的条件进行了深入探讨,取得了可喜进展。结合自己的前期工作,参考相关最新进展,就影响哺乳类SSCs体外存活、增殖、分化的因素及未来需要解决的问题进行了评述。 相似文献
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最近，由于干细胞研究普遍取得的令人鼓舞的进展以及干细胞分离、培养、移植等新技术方法的出现和发展，出生后雄性个体的生殖系干细胞——精原干细胞(spermatogonial stem cell, SSC)已成为一个愈加引人瞩目的课题。SSC位于睾丸曲细精管基膜上，既具有自增殖(self-renewal)潜能和定向分化潜能，又是自然状态下出生后个体内在整个生命期间能够进行自增殖并能将基因传递至子代的惟一成体干细胞。了解干细胞增殖与分化的调节机制，获得足够数量的种子细胞一直是所有干细胞研究共同面临的迫切问题之一。近年来，借助于SSCs移植技术这一功能性检测方法，国内外学者就SSCs体外培养的条件进行了深入探讨，取得了可喜进展。结合自己的前期工作，参考相关最新进展，就影响哺乳类SSCs体外存活、增殖、分化的因素及未来需要解决的问题进行了评述。 相似文献
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牛乳腺上皮细胞的分离培养 总被引：23，自引：0，他引：23
比较了几种乳腺细胞分离培养方法的特点。实验证明：胶原酶消化法和组织块种植法均可用于培养牛原代乳腺细胞。其中,胶原酶消化法容易得到均匀的乳腺细胞,且上皮细胞所占比例也比较高;组织块培养法不容易丢失、损伤上皮细胞,但上皮细胞长出较晚,且占比例较低,然而,用于培养小动物乳腺组织具有优势,并且可结合组织块转移、胰蛋白酶消化纯化上皮细胞,用此方法本实验获得了牛乳腺上皮细胞富集的细胞系;同时讨论了乳腺上皮细胞增殖与分化的关系,提出终末分化的腺上皮细胞已不再分裂增殖的观点。 相似文献
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Reddien PW Oviedo NJ Jennings JR Jenkin JC Sánchez Alvarado A 《Science (New York, N.Y.)》2005,310(5752):1327-1330
We have identified two genes, smedwi-1 and smedwi-2, expressed in the dividing adult stem cells (neoblasts) of the planarian Schmidtea mediterranea. Both genes encode proteins that belong to the Argonaute/PIWI protein family and that share highest homology with those proteins defined by Drosophila PIWI. RNA interference (RNAi) of smedwi-2 blocks regeneration, even though neoblasts are present, irradiation-sensitive, and capable of proliferating in response to wounding; smedwi-2(RNAi) neoblast progeny migrate to sites of cell turnover but, unlike normal cells, fail at replacing aged tissue. We suggest that SMEDWI-2 functions within dividing neoblasts to support the generation of cells that promote regeneration and homeostasis. 相似文献
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Pluripotent cells in the embryo can generate all cell types, but lineage-restricted cells are generally thought to replenish adult tissues. Planarians are flatworms and regenerate from tiny body fragments, a process requiring a population of proliferating cells (neoblasts). Whether regeneration is accomplished by pluripotent cells or by the collective activity of multiple lineage-restricted cell types is unknown. We used ionizing radiation and single-cell transplantation to identify neoblasts that can form large descendant-cell colonies in vivo. These clonogenic neoblasts (cNeoblasts) produce cells that differentiate into neuronal, intestinal, and other known postmitotic cell types and are distributed throughout the body. Single transplanted cNeoblasts restored regeneration in lethally irradiated hosts. We conclude that broadly distributed, adult pluripotent stem cells underlie the remarkable regenerative abilities of planarians. 相似文献
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［目的］分析河南省铜山湖淡水三角涡虫的核型,以期为其分类提供依据。［方法］采用空气干燥法制备染色体,对在河南省驻马店境内铜山湖产地首次采到的数十条淡水三角涡虫进行核型分析。［结果］研究发现,该产地三角涡虫中期分裂细胞中,染色体数目以25条为主（70.1%）,还有少部分24条（14.2%）,极少数16条（2.8%）,是以三倍体2n=3x=24＋1B为主,兼有很少的三倍体2n=3x=24和二倍体2n=2x=16的形式,8组中,最大组染色体的相对长度是最小组的2倍多,形态多为中着丝粒染色体。核型公式为2n=3x=24＋1SB,表现出明显的二倍体和三倍体共存的多态性,总体属于2B。［结论］该分析结果为明确河南省淡水涡虫在我国物种上分布的地位提供基础资料。 相似文献
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Translating stem and progenitor cell biology to the clinic: barriers and opportunities 总被引：1，自引：0，他引：1
Weissman IL 《Science (New York, N.Y.)》2000,287(5457):1442-1446
Stem cells are the natural units of embryonic generation, and also adult regeneration, of a variety of tissues. Recently, the list of tissues that use the model of differentiation from stem to progenitor to mature cell has increased from blood to include a variety of tissues, including both central and peripheral nervous systems and skeletal muscle; it is also possible that all organs and tissues are derived from, and still contain, stem cells. Because the number and activities of stem cells and their progeny are homeostatically regulated, clinical stem cell transplantation could greatly add to the physician's armamentarium against degenerative diseases. 相似文献
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试验说明杨梅癌肿病病原细菌也可从叶痕或皮孔侵入茎,在薄壁细胞内大量繁殖并继续向茎皮层侵染,皮层薄壁细胞受到细菌分泌物的刺激,细胞分裂,使皮层细胞数目增多,向外突出形成肿瘤,肿瘤内有大量薄壁细胞及排列不规则的输导组织;后者与茎内的维管组织相连,结果使寄主体内的部分物质物质运往病部,消耗于肿瘤的生长,枝梢得不到充足的水分和养料,可能是造成肿瘤以上枝梢枯死的原因之一。 相似文献
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Generalized potential of adult neural stem cells 总被引：1，自引：0，他引：1
Clarke DL Johansson CB Wilbertz J Veress B Nilsson E Karlström H Lendahl U Frisén J 《Science (New York, N.Y.)》2000,288(5471):1660-1663
The differentiation potential of stem cells in tissues of the adult has been thought to be limited to cell lineages present in the organ from which they were derived, but there is evidence that some stem cells may have a broader differentiation repertoire. We show here that neural stem cells from the adult mouse brain can contribute to the formation of chimeric chick and mouse embryos and give rise to cells of all germ layers. This demonstrates that an adult neural stem cell has a very broad developmental capacity and may potentially be used to generate a variety of cell types for transplantation in different diseases. 相似文献
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Multilineage potential of adult human mesenchymal stem cells 总被引：7，自引：0，他引：7
Pittenger MF Mackay AM Beck SC Jaiswal RK Douglas R Mosca JD Moorman MA Simonetti DW Craig S Marshak DR 《Science (New York, N.Y.)》1999,284(5411):143-147
Human mesenchymal stem cells are thought to be multipotent cells, which are present in adult marrow, that can replicate as undifferentiated cells and that have the potential to differentiate to lineages of mesenchymal tissues, including bone, cartilage, fat, tendon, muscle, and marrow stroma. Cells that have the characteristics of human mesenchymal stem cells were isolated from marrow aspirates of volunteer donors. These cells displayed a stable phenotype and remained as a monolayer in vitro. These adult stem cells could be induced to differentiate exclusively into the adipocytic, chondrocytic, or osteocytic lineages. Individual stem cells were identified that, when expanded to colonies, retained their multilineage potential. 相似文献
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[目的]建立绒山羊胚胎干细胞体系。[方法]采用与其胎儿成纤维细胞共培养的方式从20 mm绒山羊胎儿生殖嵴及其周围组织分离克隆出大量原始生殖细胞(PGCS)集落。[结果]这些集落的细胞经过多次传代具有胚胎干细胞(ES)的诸多特征,如鸟巢状结构、AKP染色阳性、具有连续传代能力等。[结论]该细胞具有多能性,类似ES细胞。 相似文献
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Out of Eden: stem cells and their niches 总被引：2，自引：0，他引：2
Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. Both intrinsic and extrinsic signals regulate stem cell fate and some of these signals have now been identified. Certain aspects of the stem cell microenvironment, or niche, are conserved between tissues, and this can be exploited in the application of stem cells to tissue replacement therapy. 相似文献
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本文报道了药用植物鸭跖草的根、茎和叶的解剖结构。鸭跖草的木质部为六原型，韧皮部与木质部排列，根皮层中分布有粘液细胞和晶体细胞。其内皮层具凯氏带。茎中维管束散生，许多近表皮薄壁组织细胞中含有分散的或成束的多个晶体，茎中央薄壁组织中含有粘液细胞和单宁细胞。叶为两面叶，叶肉组织分栅栏组织和海绵组织，栅栏组织细胞一层，叶中含有粘液细胞和晶体细胞。 相似文献