鸡有核红细胞凋亡的电镜观察

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。     

BMP12基因和间充质干细胞修复兔跟腱缺损的形态学研究

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。     

间充质干细胞与人发角蛋白人工腱联合培养的形态学

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。     

长春新碱诱导的自噬性细胞凋亡对线粒体膜电位的影响

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。     

放线菌酮诱导鸡胚脾脏的细胞凋亡

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     

CD200 attenuates methamphetamine-induced microglial activation and dopamine depletion

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.