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1.
Migration and differentiation of cerebral cortical neurons after transplantation into the brains of ferrets 总被引：4，自引：0，他引：4
S K McConnell 《Science (New York, N.Y.)》1985,229(4719):1268-1271
Cells from the cerebral proliferative zones of newborn ferrets were labeled with tritiated thymidine and a fluorescent dye and were transplanted as a single-cell suspension into the occipital region of newborn ferrets. The transplanted cells became thoroughly integrated into the host environment: many cells migrated through the intermediate zone and into the cortical plate, where they developed as pyramidal neurons. Other transplanted cells came to resemble glial cells. After 1 to 2 months most transplanted neurons had taken up residence in layer 2 + 3, the normal destination of neurons generated on postnatal days 1 and 2. Thus the sequence of morphological differentiation and the eventual laminar position of the isochronically transplanted neurons closely paralleled that of their normal host counterparts. 相似文献
2.
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
3.
Labeling of neural cells by gold-filled Sendai virus envelopes before intracerebral transplantation 总被引：1，自引：0，他引：1
Gold-filled Sendai virus envelopes were fused with cell suspensions from the basal forebrain of fetal rat donors, and the resulting gold-labeled cells were transplanted into the neocortex of adult rat recipients. Not only did large numbers of labeled cells remain intact through 3 months in the neocortex, but sizable numbers migrated subcortically to the recipient's lesioned nucleus basalis region (a distance of 4 to 5 millimeters). Since this technique is capable of labeling most transplanted cells for long periods of time, it may be useful in determining the survival, migration, and connectivity of intracerebrally transplanted tissues. 相似文献
4.
Cell cycle dependence of laminar determination in developing neocortex 总被引：29，自引：0，他引：29
The neocortex is patterned in layers of neurons that are generated in an orderly sequence during development. This correlation between cell birthday and laminar fate prompted an examination of how neuronal phenotypes are determined in the developing cortex. At various times after labeling with [3H]thymidine, embryonic progenitor cells were transplanted into older host brains. The laminar fate of transplanted neurons correlates with the position of their progenitors in the cell cycle at the time of transplantation. Daughters of cells transplanted in S-phase migrate to layer 2/3, as do host neurons. Progenitors transplanted later in the cell cycle, however, produce daughters that are committed to their normal, deep-layer fates. Thus, environmental factors are important determinants of laminar fate, but embryonic progenitors undergo cyclical changes in their ability to respond to such cues. 相似文献
5.
T L Dao 《Science (New York, N.Y.)》1969,165(895):810-811
Mammary glands were transplanted from donors treated with 7,12-dimethylbenz(a)anthracene to untreated isologous recipients. Incidence of mammary tumors in mammary grafts from 56-day-old donors was significantly higher than that in grafts from 120-day-old donors, regardless of the age of the recipient hosts. Whent mammary glands were transplanted from untreated donors to isologous recipients that subsequently received 7,12-dimethyl-benz(a)anthracene, a similar difference in tumor incidence in the grafts was observed. In contrast to mammary glands of older females, mammary glands of young adult female rats are highly vulnerable to the carcinogenic effect of 7,12-dimethylbenz(a)anthracene. 相似文献
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Transfer of bilirubin uridine diphosphate-glucuronyltransferase to enzyme-deficient rats 总被引：2，自引：0，他引：2
Cells from a clonal strain (MH(1)C(1)) of rat hepatoma were transplanted subcutaneously into two homozygous Gunn rats, which are jaundiced because the enzyme bilirubin uridine diphosphate-glucuronyltransferase is absent from the liver. Because of the enzyme activity present in the transplanted cells, the recipient rats developed the capacity to conjugate bilirubin and reverted in large part to a normal pattern of bilirubin excretion. 相似文献
8.
将鼻咽癌克隆细胞株ＣＮＥ－２Ｚ－Ｈ５／Ｆ１移植入裸鼠痛部皮下，观察其自发性转移，进而用克隆株Ｈ５移植瘤的淋巴结及肺转移灶组织，直接接种裸鼠背部皮下，研究其转移表型的改变。结果显示：克隆株Ｈ５和Ｆ１的转移率不同；Ｈ５淋巴结转移灶及肺转移灶移植瘤，和其原代移植瘤比，其转移能力和转移途径有明显的差异。 相似文献
9.
烟粉虱繁殖力的寄主适应性评估及分析 总被引：1，自引：0，他引：1
以种群平均产卵量(m)和样本的方差(V)为参数建立了1个烟粉虱产卵量的寄主适应性评价模型(0=m/lnV),并利用这个模型评估了烟粉虱在37种寄主植物上的产卵适应度.结果显示,烟粉虱虽然在供试的绝大多数寄主上都能够产卵,但寄主植物能够显著影响雌虫的产卵量.用聚类分析的方法可将37种寄主植物分为3个类别:嗜好寄主、适宜寄主和非适宜寄主,聚类分析的结果与适应域假说不一致,亲缘关系很近的植物种类分属于不同的寄主类别.通过配对样本均值比较的分析发现,不同生物型的烟粉虱种群具有明显差异,而相同生物型的种群,虽然取食经验不同,却表现出较高的相似性. 相似文献
10.
研究鼻咽癌克隆株ＣＮＥ－２Ｚ－Ｈ５高淋巴道转移裸鼠移植瘤离体培养细胞的细胞遗传学改变并探讨这种改变与肿瘤生物学特性之间的关系。方法染色体Ｇ显带后按人类细胞遗传学国际命名体制进行核型分析。 相似文献
11.
Expression of a retrovirus encoding human HPRT in mice 总被引：32，自引：0，他引：32
A D Miller R J Eckner D J Jolly T Friedmann I M Verma 《Science (New York, N.Y.)》1984,225(4662):630-632
Transmissible retroviruses encoding human hypoxanthine phosphoribosyltransferase (HPRT) were used to infect mouse bone marrow cells in vitro, and the infected cells were transplanted into mice. Both active human HPRT-protein and chronic HPRT-virus production were detected in hematopoietic tissue of the mice, showing transfer of the gene. These results indicate the possible use of retroviruses for somatic cell therapy. 相似文献
12.
目的 研究猪睾丸组织注射白消安消融猪内源精原干细胞(Spermatogonial stem cell,SSC)的效果,以及猪SSC同种异体移植后对内源性SSC消融受体生殖能力恢复的影响。方法 采用3 mg/kg剂量的白消安对9头6周龄大白公猪进行睾丸注射,另外3头注射2 mL 二甲基亚砜作为对照。3周后,对试验组公猪以相同剂量进行第2次睾丸注射。第2次注射3周后,采集试验组和对照组公猪睾丸进行相关检测,评估内源性SSC消融情况。第2次白消安注射1个月后,以两步酶消化法处理5~7日龄大白仔猪睾丸分离得到睾丸单细胞悬液,并用明胶差速贴壁法进行纯化,纯化后以免疫荧光和流式细胞术分析SSC的纯度。异体移植SSC 4个月后,用微卫星标记检测受体公猪精液以及睾丸组织中供体来源SSC的存在。结果 以3 mg/kg剂量的白消安处理大白公猪2次后,睾丸组织苏木精−伊红染色以及免疫组织化学染色结果显示,试验组睾丸曲细精管中各级生精细胞消融但其支持细胞结构完好,可以支持外源性SSC的定植及发育。免疫荧光以及流式细胞术结果表明,分离得到的睾丸单细胞悬液经纯化后UCHL-1阳性细胞占比由差速贴壁前的16.3%提高到了50.8%。苏木精−伊红染色以及免疫组织化学染色结果显示,猪SSC移植4个月后,移植组睾丸组织生精细胞恢复,在受体睾丸曲细精管基底膜上可检测到UCHL-1阳性SSC。受体睾丸组织的微卫星标记分析显示了供体SSC的存在,表明移植进入受体睾丸中的供体SSC可以在受体睾丸中定植存活超过4个月;精液微卫星标记未检测到供体来源的精子。结论 以3 mg/kg剂量的白消安注射公猪睾丸能有效消融内源性SSC,可以用来制备SSC移植的受体猪。两步酶消化及明胶差速贴壁法可成功分离纯化猪SSC。猪SSC经同种异体移植后可以在受体睾丸中定植存活超过4个月。 相似文献
13.
Milk of dairy cows frequently contains a leukemogenic virus 总被引：2，自引：0，他引：2
Milk or viable milk cells collected from 24 dairy cattle naturally infected with bovine leukemia virus were inoculated into lambs, which were subsequently examined for the development of infection. With this bioassay, infectious virus was demonstrated in the milk of 17 of the cows. Bovine leukemia virus is leukemogenic in at least two mammalian species, is widespread in commercial dairy herds, and can infect a wide range of hosts in vivo and cells, including human cells, in vitro. 相似文献
14.
Fetal raphe cells transplanted into the hypothalamus reversed facilitation of feminine sexual behavior in rats with brain lesions induced by 5,7-dihydroxytryptamine. Immunocytochemical and chemical analyses of serotonin indicate that reinnervation of the ventromedial nucleus of the hypothalamus by the transplants is associated with behavioral recovery. The findings suggest that transplanted fetal tissue can exert functional regulation over an innate, complex, hormone-dependent behavior in adult rats. 相似文献
15.
利用系统发育分析和RAPD技术对我国南京及周边地区的20株昆虫和植物花螺原体的分类地位和遗传多样性进行分析。结果表明:大多数菌株与Spiroplasma melliferum聚类,位于以16S rDNA序列构建的螺原体系统发育树的Citri-Chry-sopicola-Mirum类群;菌株ZHUF0901和MF0905位于Apis群内,但二者又分为2个不同的分支。利用筛选的34条RAPD引物共检测出664个位点,其中多态性位点数644个,多态性比率为96.99%。UPGMA聚类分析表明,在相似性系数达到0.6时,与Spiroplasma melliferum聚类的18株菌可根据螺原体宿主的不同分为明显的3个类群,菌株ZHUF0901与MF0905各为一类。同一时期不同宿主(植物花、蜜蜂以及其他昆虫)中的蜜蜂螺原体Spiroplasma melliferum亲缘关系很近,说明自然界中螺原体可通过水平传播方式进行传播。 相似文献
16.
Main JH 《Science (New York, N.Y.)》1966,152(3723):778-780
When tooth germs derived from 14-day mouse embryos were cultured on gelatin sponges in vitro for 37 days, they lost their characteristic morphology, appearing as a layer of undifferentiated epithelium on the sponge surface, with the mesenchymal cells scattered throughout the interstices. These cultures were then transplanted subcutaneously into isologous, newborn recipients and, over a period of 56 days, developed into incisor teeth that were almost perfect in shape and structure. 相似文献
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18.
对２０株黄芪根瘤菌进行了Ｃ,Ｎ源利用、抗生素抗性、耐逆性和酶活性研究。结果表明,不同地区,甚至同一地区或同种寄主来源的菌株存在着多样性。以ＵＰＧＭＡ聚类,在７５％的相似性水平上,分成５个表观群,其与已知根瘤菌Ｍ．ｈｕａｋｕｉ明显不同。 相似文献
19.
Rejection of renal allografts: specific immunologic suppression 总被引：17，自引：0，他引：17
Kidneys were transplanted across a major genetic barrier (Ag-B locus), from LewisxBN F(1) hybrid rats into bilaterally nephrectomized Lewis rats. Survival of grafts is prolonged (indefinite?) in rats treated with a combination of (i) intravenous injection of donor spleen cells 1 day before the graft, and (ii) passive immunization with antiserum prepared in rats of the recipient strain against donor spleen and lymph-node cells. The recipient's immune response to other antigens is not impaired. 相似文献
20.
A transmissible agent or factor has been found to be associated with all transplanted and spontaneous experimental tumors examined. This observation was made possible by utilization of a biochemical response of normal animals when inoculated with plasma or organ extracts from tumor-bearing hosts. This transmissible enzymic "lesion" is expressed by a five- to tenfold increase in the plasma lactic dehydrogenase activity of the injected normal test animals. The factor is heat labile, passes through bacteria-retaining filters, but is nondialyzable. It is partially sedimented by centrifugation at 100,000g for 1 hour. 相似文献