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41.
利用透射电镜观察了正常成年鸡脾内红细胞的凋亡现象。结果显示,鸡脾内凋亡红细胞核染色质先呈现网眼样变化,后浓缩、边聚。凋亡红细胞整个被巨噬细胞吞噬,在其中分解变小成为凋亡小体。凋亡小体电子密度有的升高,有的降低,最后均被巨噬细胞消化清除。结果表明,有核的红细胞发生细胞凋亡,并借助于巨噬细胞的膜系统完成凋亡过程。 相似文献
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BMP12基因和间充质干细胞修复兔跟腱缺损的形态学研究 总被引:4,自引:0,他引:4
目的 观察用BMP12基因和间充质干细胞修复兔跟腱缺损的形态学变化。方法 模拟微重力条件下构建两种组织工程化肌腱。 2 4只新西兰白兔分为 4组 :①单纯人发角蛋白 (HHK对照组 )组 ;②骨髓间充质干细胞 (MSCs) /HHK组织工程化肌腱组 ;③骨形态发生蛋白 12 (BMP12 )基因诱导的腱细胞 /HHK组织工程化肌腱组 ;④pTARGET BMP12质粒 /HHK组。采用光电镜、免疫组织化学和RT PCR方法观察术后不同时期损伤肌腱的修复情况。结果 MSCs/HHK组织工程化肌腱组和基因诱导的腱细胞 /HHK组织工程化肌腱组的缺损肌腱的再生修复效果均优于单纯HHK组 ,尤以基因诱导的腱细胞 /HHK组织工程化肌腱组的修复效果最佳 ,且伴随有Ⅰ型胶原mRNA表达的增高。结论 BMP12基因和MSCs通过促进内源性愈合参与了缺损肌腱的再生修复。 相似文献
43.
目的:研究培养的人骨髓间充质干细胞(MSCs)与人发角蛋白(HHK)人工腱的相容性以及MSCs在HHK上的生长情况。方法:人MSCs与HHK人工腱联合培养后,分别在倒置显微镜及扫描电镜和透射电镜下观察MSCs的生长状态和超微结构。结果:MSCs在光镜下呈单层或多层贴附于HHK人工腱表面,扫描电镜下呈细长梭形,有的呈扁平多角形,其生长方向与HHK人工腱长轴相一致。透射电镜下可见静息态和活动态两种不同功能状态。结论:MSCs与HHK人工腱之间有极好的粘附性和相容性,是一种理想的组织工程种子细胞。 相似文献
44.
长春新碱诱导的自噬性细胞凋亡对线粒体膜电位的影响 总被引:7,自引:0,他引:7
目的:了解长春新碱(VCR)诱导的自噬性细胞凋亡是否与线粒体跨膜电位(△Ψm)改变有关及其可能的机制。材料与方法:以正常人的肝细胞系为体外模型,应用碘化丙啶(PI)/Rhodamine123(Rh123)双重染色检测△Ψm,通过亚GI期细胞和透射电镜鉴定细胞凋亡。结果与结论:VCR可明显诱导线粒体△Ψm下降,也可以诱导L-02细胞自噬性凋亡。线粒体△Ψm下降可能是VCR诱导自噬性细胞凋亡的关键环节。 相似文献
45.
为探讨放线菌酮与鸡胚期脾脏细胞凋亡的关系,采用透射电镜观察了经放线菌酮处理的鸡胚第41~42期脾脏的超微结构。结果显示正常发育组可见衰老血细胞凋亡,放线菌酮处理组则出现大量的幼稚血细胞凋亡。凋亡的幼稚血细胞核致密,染色深,药物诱导的凋亡早期出现线粒体增多,后期为内质网增多。巨噬细胞既吞噬正常凋亡细胞也吞噬放线菌酮诱导的凋亡细胞 相似文献
46.
This study examined the neuroprotective effect of cluster of differentiation molecule 200 (CD200) against methamphetamine (METH)-induced neurotoxicity. In the in vitro experiment, neuron-microglia cultures were treated with METH (20 μmol/L), METH (20 μmol/L)+CD200-Fc (10 μg/mL) or CD200-Fc (10 μg/mL). Those untreated served as control. Microglia activation expressed as the ratio of MHC-Ⅱ/CD11b was assessed by flow cytometry. The cytokines (IL-1β, TNF-α) secreted by activated microglia were detected by enzyme-linked immunosorbent assay (ELISA). In the in vivo experiment, 40 SD rats were divided into control, METH, METH+CD200-Fc and CD200-Fc groups at random. Rats were intraperitoneally injected with METH (15 mg/kg 8 times at 12 h interval) in METH group, with METH (administered as the same dose and time as the METH group) and CD200-Fc (1 mg/kg at day 0, 2, 4 after METH injection) in METH+CD200-Fc group, with CD200-Fc (1 mg/kg injected as the same time as the METH+CD200-Fc group) or with physiological saline solution in the control group. The level of striatal dopamine (DA) in rats was measured by high-performance liquid chromatography (HPLC). The microglial cells were immunohistochemically detected for the expression of Iba-1, a marker for microglial activation. The results showed that METH could increase the microglia activation in the neuron-microglia cultures and elevate the secretion of IL-1β and TNF-α, which could be attenuated by CD200-Fc. Moreover, CD200-Fc could partially reverse the striatal DA depletion induced by METH and reduce the number of activated microglia, i.e. Iba-1-positive cells. It was concluded that CD200 may have neuroprotective effects against METH-induced neurotoxicity by inhibiting microglial activation and reversing DA depletion in striatum. 相似文献