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关键词： 胰腺干细胞   糖尿病   诱导分化   胰岛移植  

摘要： 分离人胚胎胰腺组织中的胰岛细胞于体外培养,应用免疫细胞化学及RT-PCR的方法对其中的胰腺干细胞进行鉴定,并应用免疫磁珠的方法纯化其中的干细胞。结论是人胚胎胰腺组织中存在一定比例的干细胞,可以作为体外向胰岛素分泌细胞诱导分化的细胞来源。

关键词： 人体组织学   医学院校   教材   人体胚胎学  

ISBN: (纸本)7534937043

摘要： 全国医学高等教育教材:本书为组织学与胚胎学高等教育教材。

关键词： nanofibers   nanofibrillar surfaces   extracellular matrix   mouse embryonic fibroblasts   myosin II-B   fibronectin   laminin-1   collagen I  

摘要： Growth of cells in tissue culture is generally performed on two-dimensional (213) surfaces composed of polystyrene or glass. Recent work, however, has shown that such 2D cultures are incomplete and do not adequately represent the physical characteristics of native extracellular matrix (ECM)/basement membrane (BM), namely dimensionality, compliance, fibrillarity, and porosity. In the current study, a three-dimensional (3D) nanofibrillar surface composed of electrospun polyamide nanofibers was utilized to mimic the topology and physical structure of ECM/BM. Additional chemical cues were incorporated into the nanofibrillar matrix by coating the surfaces with fibronectin, collagen I. or laminin-1. Results from the current study show an enhanced response of primary mouse embryonic fibroblasts (MEFs) to culture on nanofibrillar surfaces with more dramatic changes in cell spreading and reorganization of the cytoskeleton than previously observed for established cell lines. In addition, the cells cultured on nanofibrillar and 2D surfaces exhibited differential responses to the specific ECM/BM coatings. The localization and activity of myosin II-B for MEFs cultured on nanofibers was also compared. A dynamic redistribution of myosin II-B was observed within membrane protrusions. This was previously described for cells associated with nanofibers composed of collagen I but not for cells attached to 2D surfaces coated with monomeric collagen. These results provide further evidence that nanofibrillar surfaces offer a significantly different environment for cells than 2D substrates.

关键词： tooth development   TCDD   gene expression   dioxin   tooth morphology  

摘要： Dioxins are ubiquitous environmental poisons that cause disturbances in developing organs, including the teeth. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at the cap stage leads to reduced tooth size and deformation of cuspal morphology. Our hypothesis was that TCDD affects the expression of genes specific for tooth development, which leads to these aberrations. Mouse embryonic E14 tooth germs were cultured for 24 hrs with/without 1 mu M TCDD. Analysis of total RNA on Affymetrix arrays showed that TCDD altered the expression of 31 known genes by a fold factor of at least 2. Genes implied in tooth development expressed only slight changes. Genes active at the cap stage were selected for quantitative PCR analysis. Of these, the most highly up-regulated were Follistatin and Runx2, while TGF beta 1 and p21 were the most down-regulated genes. Incomplete tooth morphogenesis caused by TCDD may thus result from modified expression of developmentally regulated genes.

关键词： equine zona pellucida   ZPB   ZPC   N-acetylglucosamine   scanning electron microscopy   confocal laser scanning microscopy  

摘要： In the equine, the zona pellucida (ZP) is the major barrier to successful in vitro fertilization. Therefore the aim of our studies was to analyze species-specific features of the equine ZP in regard to structure and glycoprotein ZPB and ZPC expression sites during oocyte development and embryogenesis. The equine ZP revealed high immunological crossreactivity to porcine ZPB and ZPC. In the ovary, the distribution of ZPB and ZPC was co-localized and correlated with the developmental stage of the follicle. ZPB and ZPC expression started in the oocyte of the late primordial and primary follicle. In the secondary follicle, both the oocyte and the cumulus cells contributed to ZPB and ZPC synthesis. After in vivo maturation the oocyte stopped ZPB and ZPC production whereas the cumulus cells continued synthesis. Contrary, in vitro matured (IVM) cumulus-oocytecomplexes (COCs) revealed a reverse expression pattern. This was correlated to alterations in the distribution, number, and size of pores in the ZP. In the zona, N-acetylglucosamine residues were colocalized with ZPC. The acellular glycoprotein capsule surrounding early equine embryos was negative for ZPB and ZPC. Our results imply that in the horse ZPB and ZPC glycoprotein expression is differentially regulated during folliculogenesis, oocyte maturation, and embryogenesis. Contrary to the bovine and porcine, zona protein synthesis during in vivo maturation is completely overtaken by the cumulus cells implying that in the horse these cells are crucial for zona integrity. During IVM, the cumulus cells lose their ability to synthesize glycoproteins leading to alterations in the zona structure.

关键词： 人体胚胎学   成人教育：高等教育   教材   人体组织学  

ISBN: (纸本)9787504646934

摘要： 本书讲述了组织学与胚胎学研究内容及其意义和组织学和胚胎学研究的相关技术。并从细胞的概况和结构及增殖、细胞的运行性切入，分别讲述了上皮组织、神经组织、免疫系统等知识。

关键词： 人体解剖学   图谱   医学院校   教材   人体组织学：人体胚胎学  

ISBN: (纸本)7538435077

摘要： 本书为医学院校教材。主要介绍解剖学与组织胚胎学的典型图谱，使学生对解剖学与组织胚胎学有个全面的了解。

关键词： 人体解剖学   专业学校   教材   人体组织学：人体胚胎学  

ISBN: (纸本)7810717219

摘要： 全国中等卫生学校教材:本书作为中等医学教材，共13章，涵盖了中等医学教育病理学大纲所要求的内容，每章后安排了相应的练习和答案，并包括实验项目。

关键词： sea urchin   embryo   primary mesenchyme   cell migration   guidance   differentiation   VEGF   skeleton   morphogenesis  

摘要： During development, cell migration plays an important role in morphogenetic processes. The construction of the skeleton of the sea urchin embryo by a small number of cells, the primary mesenchyme cells (PMCs), offers a remarkable model to study cell migration and its involvement in morphogenesis. During gastrulation, PMCs migrate and become positioned along the ectodermal wall following a stereotypical pattern that determines skeleton morphology. Previous studies have shown that interactions between ectoderm and PMCs regulate several aspects of skeletal morphogenesis, but little is known at the molecular level. Here we show that VEGF signaling between ectoderm and PMCs is crucial in this process. The VEGF receptor (VEGFR) is expressed exclusively in PMCs, whereas VEGF expression is restricted to two small areas of the ectoderm, in front of the positions where the ventrolateral PMC clusters that initiate skeletogenesis will form. Overexpression of VEGF leads to skeletal abnormalities, whereas inhibition of VEGF/VEGFR signaling results in incorrect positioning of the PMCs, downregulation of PMC-specific genes and loss of skeleton. We present evidence that localized VEGF acts as both a guidance cue and a differentiation signal, providing a crucial link between the positioning and differentiation of the migrating PMCs and leading to morphogenesis of the embryonic skeleton.

关键词： cardiac   heart development   hypoxia-inducible factor   intrauterine growth retardation  

摘要： Embryos can be exposed to environmental factors that induce hypoxia. Currently, our understanding of the effects of hypoxia on early mammalian development is modest. Potential mediators of hypoxia action include the nucleoside adenosine, which acts through A(1) adenosine receptors (A(1)ARs) and mediates adverse effects of hypoxia on the neonatal brain. We hypothesized that A(1)ARs may also play a role in mediating effects of hypoxia on the embryo. When pregnant dams were exposed to hypoxia (10% O-2) beginning at embryonic day (E) 7.5 or 8.5 and continued for 24-96 h, A(1)AR+/+ embryos manifested growth inhibition and a disproportionate reduction in heart size, including thinner ventricular walls. Yet, when dams were exposed to hypoxia, embryos lacking A(1)ARs (A(1)AR-/-) had much more severe growth retardation than A(1)AR+/+ or +/- embryos. When levels of hypoxia-inducible factor 1 alpha (HIF1 alpha) were examined, A(1)AR-/- embryos had less stabilized HIF1 alpha protein than A(1)AR+/- littermates. Normal patterns of cardiac gene expression were also disturbed in A(1)AR-/- embryos exposed to hypoxia. These results show that short periods of hypoxia during early embryogenesis can result in intrauterine growth retardation. We identify adenosine and A(1)ARs as playing an essential role in protecting the embryo from hypoxia.