滋养层

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cytoplasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methylation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribution of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cyto-plasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methy-lation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribu-tion of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

On the functional differentiation,we found and that the type II ras-GTPaseactivating protein (p100-GAP),which was specifically expressed in humanplacenta,was largely expressed in the highly-differentiated syncytiotrophoblastcells and moderately expressed in the cultured intermediate trophoblast cells.While in the non-differentiated cytotrophoblast cell line-NPC,no expression was observed.Its mRNA and protein expressingcharacterization was in consistent with that of hCGβ,which was one of the mostimportant markers of the trophoblast cell functional differentiation.In addition,the expressing amount of p100-GAP increased with the progressing of pregnancyand the syncytium formation in vitro.

细胞功能分化的研究结果表明：经重组质粒的构建获得特异表达于人胎盘的p100－GAP的cDNA探针后，从蛋白和分子水平证实p100－GAP大量表达于分化程度高的合体滋养层细胞，少量表达于体外培养的中间型滋养层细胞，而非分化的细胞滋养层细胞NPC则不表达，这种表达特性与作为滋养层细胞功能分化重要指标之一的hCGβ高度一致；p100-GAP表达量还随妊娠过程和体外合体化过程而逐渐增加。

Trophoblast Medium is a complete medium designed for optimal growth of normal human trophoblast in vitro .

滋养层细胞培养基是专门为正常人类滋养层细胞体外培养设计的最适于其生长的培养基。

These results suggest that flow-induced shear stress regulates the expression of β1 integrin, in turn affects the motility of trophoblast cells.

流动剪切力的参与调节了滋养层细胞β1 整合素的表达，从而可影响滋养层细胞的迁移。

The methods of trophoblast isolation have deficiency of low product ion rate and other cells contamination.

原代培养的滋养层细胞存在产率低、杂细胞污染等方面的缺憾，而滋养层细胞又在细胞特性上发生了变化。

Uu not only bring out corresponding ultrapathological changes by adhering to the surface of the cytotrophoblast membrane,but also enters the body of the cytotrophoblast and does harm to them directly.

Uu不仅吸附在滋养层细胞膜表面诱发相应的超微病理改变，而且还进入滋养层细胞体内，对滋养层细胞产生直接杀伤作用。

Results The expression of ADAM19 are mainly in the cell membrane, plasma and column of cytotrophoblast; The expression of ADAM19 is mainly located on cytotrophoblast during first trimester of pregnancy, and on syncytiotrophoblast in second and third trimester.

结果ADAM19的表达主要集中在滋养细胞的细胞膜、细胞质中和细胞滋养层柱细胞中；早孕绒毛中，ADAM19表达主要集中于细胞滋养细胞膜，在晚孕期胎盘，ADAM19主要表达于合体滋养细胞膜。

From the early study of the pathogenesis of pre-eclampsia people have found its association with immunological function . In 1986 Ellis et al[1] had found that the extravillous chorionic cytotrophoblast contacting with the maternal tissue expressed high levels of Human leukocyte antigen-G, a major histocompatibility tissue-specific antigen . Extravillous chorionic cytotrophoblast with high levels expression of HLA-G proteins can invade the maternal deciduas and the maternal spiral arteries by displacing the endothelial lining and destroying most of the musculoelastic tissue of these arteries .

早期研究开始，许多学者即发现其与免疫学有密切关系，至1986年Ellis等[1]发现人类白细胞抗原(human leukocyte antigen，HLA) G分子高度表达在绒毛外滋养层细胞( extravillous cytotrophoblast，EVCT)上，即浸润至子宫蜕膜层甚至达子宫浅肌层以及子宫螺旋动脉内皮层，与母血及子宫组织直接接触的滋养细胞，这种独特的组织分布提示HLA-G分子在母胎免疫耐受方面起重要作用。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失