Effects of Selenium Yeast on Oxidative Stress,Growth Inhibition,and Apoptosis in Human Breast Cancer Cells

Recent evidence suggests that selenium (Se) yeast may exhibit potential anti-cancer properties; whereas the precise mechanisms remain unknown. The present study was aimed at evaluating the effects of Se yeast on oxidative stress, growth inhibition, and apoptosis in human breast cancer cells. Treatments of ER-positive MCF-7 and triple-negative MDA-MB-231 cells with Se yeast (100, 750, and 1500 ng Se/mL), methylseleninic acid (MSA, 1500 ng Se/mL), or methylselenocysteine (MSC, 1500 ng Se/mL) at a time course experiment (at 24, 48, 72, and 96 h) were analyzed. Se yeast inhibited the growth of these cancer cells in a dose- and time-dependent manner. Compared with the same level of MSA, cancer cells exposure to Se yeast exhibited a lower growth-inhibitory response. The latter has also lower superoxide production and reduced antioxidant enzyme activities. Furthermore, MSA (1500 ng Se/mL)-exposed non-tumorigenic human mammary epithelial cells (HMEC) have a significant growth inhibitory effect, but not Se yeast and MSC. Compared with MSA, Se yeast resulted in a greater increase in the early apoptosis in MCF-7 cells as well as a lower proportion of early and late apoptosis in MDA-MB-231 cells. In addition, nuclear morphological changes and loss of mitochondrial membrane potential were observed. In conclusion, a dose of 100 to 1500 ng Se/mL of Se yeast can increase oxidative stress, and stimulate growth inhibitory effects and apoptosis induction in breast cancer cell lines, but does not affect non-tumorigenic cells.     

听觉毛细胞死亡的分子调控

听觉毛细胞损伤是引起听力损失最常见的原因,本综述主要介绍几个信号通路,包括炎症反应、丝裂原活化蛋白激酶信号传导途径、氧化性应激等,涉及毛细胞发生毒性反应或应激反应后的程序性和坏死性死亡,揭示了引起听觉毛细胞损伤的信号通路的相互作用,以及避免听觉毛细胞因凋亡或非凋亡途径死亡的治疗干预策略。     

Differentiation of amniotic epithelial cells into various liver cell types and potential therapeutic applications

The aim of Regenerative Medicine is to replace or regenerate human cells, tissues or organs in order to restore normal function. Among all organs, the liver is endowed with remarkable regenerative capacity. Nonetheless, there are conditions in which this ability is impaired, and the use of isolated cells, including stem cells, is being considered as a possible therapeutic tool for the management of chronic hepatic disease.Placenta holds great promise for the field of regenerative medicine. It has long been used for the treatment of skin lesions and in ophthalmology, due to its ability to modulate inflammation and promote healing. More recently, cells isolated from the amniotic membrane are being considered as a possible resource for tissue regeneration, including in the context liver disease. Two cell types can be easily isolated from human amnion: epithelial cells (hAEC) and mesenchymal stromal cells (hAMSC). However only the first cell population has been demonstrated to be a possible source of proficient hepatic cells. This review will summarize current knowledge on the differentiation of hAEC into liver cells and their potential therapeutic application.     

痰液细胞在哮喘患儿病程中的动态变化及意义

目的　观察哮喘患儿痰液细胞在病程不同时相的动态变化 ,探讨其在哮喘发病中的作用。方法　收集 2 5例哮喘患儿发作之初、病情好转以及病情缓解时期的痰液 ,比较哮喘病程不同时相之间以及不同时相与 10例正常儿童之间痰液细胞成分的差异。结果　哮喘急性发作初期痰液脱落上皮细胞明显增多 ,嗜酸性粒细胞、中性粒细胞和淋巴细胞与正常对照无明显差别 ;随着病情好转 ,脱落上皮细胞数显著下降 ,而嗜酸性粒细胞数和(或 )中性粒细胞数显著升高 ,淋巴细胞与正常对照仍无明显差别 ;当病情缓解时 ,脱落上皮细胞的数量接近正常对照 ,嗜酸性粒细胞和 (或 )中性粒细胞数也显著下降 ,而淋巴细胞明显增多。结论　上皮细胞脱落可能与哮喘急性发作有关 ;嗜酸性粒细胞或中性粒细胞除造成上皮细胞脱落外 ,可能还发挥促上皮细胞再生的有益作用 ,有助于病情的恢复 ;淋巴细胞可能在维持哮喘慢性气道炎症中发挥作用。     

小鼠CD4+CD25+T细胞的分离、鉴定和体外功能的检测

目的　建立CD4 CD2 5 T细胞的免疫磁性分离(MACS)方法,并检测其体外免疫抑制功能。方法　分离C5 7BL 6小鼠和Balb c小鼠脾脏细胞后运用MACS法分离CD4 CD2 5 T淋巴细胞,用台盼蓝染色法和流式细胞法检测选出细胞的活性和纯度,用淋巴细胞转化实验分析其免疫抑制功能。结果　MACS分选法分选出的CD4 CD2 5 T细胞活性>97% ,纯度>95 % ;此方法获得的CD4 CD2 5 T细胞在体外不增殖,经丝裂原活化后可以抑制同品系小鼠和异品系小鼠的CD4 CD2 5 -T细胞增殖,这种抑制作用具有剂量依赖性。结论　MACS法可简单迅速分选出高纯度无菌CD4 CD2 5 T细胞,且不影响细胞活力。CD4 CD2 5 T调节性细胞在体外具有免疫无能和免疫抑制作用;丝裂原活化的该细胞免疫抑制功能具有剂量依赖性,但不具有抗原特异性。     

TNF及铜绿假单胞菌刺激呼吸道上皮细胞表达NOD2蛋白

目的：通过对TNF及铜绿假单胞菌（PAO1）刺激肺上皮细胞株（A549）表达胞浆蛋白NOD2的研究,进一步了解NOD2在机体天然免疫病原体识别过程中的作用。方法：培养呼吸道肺癌上皮细胞株A549,以TNF、铜绿假单胞菌PAO1刺激细胞,并以未刺激组做对照,通过半定量RT-PCR技术观察胞浆蛋白NOD2的表达变化。结果：与未刺激组比较,TNF、铜绿假单胞菌PAOI都能够上调A549细胞NOD2蛋白的表达。结论：TNFα与铜绿假单胞菌PAO1刺激能增强A549细胞胞装蛋白NOD2的表达,提示细胞内受体NOD2在呼吸道天然免疫病原体识别过程中可能起重要作用。     

抑郁症患者血中T细胞亚群数量及相关因素的研究

目的：研究抑郁症患者外周血中T细胞亚群的变化及相关因素，探讨抑郁症患者的免疫功能变化，为治疗提供新的依据。方法：应用碱性磷酸酶标记链霉卵白素法检测32例抑郁症患者和32例健康对照血中T细胞亚群数量及构成比，并与其相关因素进行多元线性回归分析。结果：1．与对照组相比，抑郁症患者血中CD3^ 、CD4^ 细胞数以及CD4^ ／CD8^ 比值明显降低，而CD8^ 细胞数明显升高。2．男性患者与抑郁症患者总体改变相同。而女性患者血中CD3^ 、CD4^ 细胞数、CD8^ 细胞数以及CD4^ ／CD8^ 比值与对照组比较差异不显著；3．多元线性回归结果：抑郁症患者血中CD8^ 细胞数与病程呈非常显著负相关。结论：抑郁症患者免疫功能低下，其免疫功能低下可能能有性别差异，而且抑郁症患者的免疫功能变化可能与病程有关。     

骨髓基质细胞和壳聚糖/明胶共混材料生物相容性研究

目的:研究壳聚糖/明胶共混材料对离体培养的骨髓基质细胞粘附及增殖的影响,寻找骨髓基质细胞新的载体材料。方法:取2周龄幼兔的长骨采集骨髓,培养骨髓基质细胞,体外扩增1周后,种植于纯壳聚糖和壳聚糖/明胶共混材料的表面。在倒置光学显微镜、扫描电镜的辅助下,观察细胞的粘附和生长情况,种植7d后用透射电镜观察细胞功能状况,用MTT方法检测种植后2d、4d、6d、8d细胞的增殖情况。结果:壳聚糖/明胶共混材料和纯壳聚糖能促进骨髓基质细胞在材料表面粘附并保持其在机体内的形态。壳聚糖/明胶共混材料表面的骨髓基质细胞功能活跃。在材料表面和培养板表面培养的骨髓基质细胞均能持续增殖,而壳聚糖/明胶共混材料能显著促进骨髓基质细胞的增殖(P<0.01)。结论:壳聚糖/明胶共混材料保持了壳聚糖的某些生物活性,同时由于加入明胶,能促进骨髓基质细胞的增殖,可作为骨髓基质细胞的载体应用于组织工程。     

骨髓间充质干细胞分化为血管内皮细胞的实验研究

目的 :探讨骨髓间充质干细胞 (MSCs)自体移植后在扩张型心肌病(DCM)微环境中分化为血管内皮细胞的可行性。方法 :以日本大耳白兔为研究对象 ,分离培养扩增MSCs,盐酸阿霉素耳缘静脉注射复制兔DCM模型 ,将 5溴脱氧尿嘧啶 (BrdU)标记的MSCs移植到DCM心肌内 ,4周后观察移植细胞的增殖分化情况。结果 :细胞移植 4周后 ,实验组心肌内有BrdU标记的阳性细胞 ,有一部分参与组成新生血管 ,对照组中没有发现 ,且实验组毛细血管密度大于对照组 ,差异具有显著性 (P<0 .0 1)。结论 :MSCs自体移植到扩张型心肌病后可以分化为血管内皮细胞。     

氨对培养胚鼠大脑神经元形态的影响

为研究氨对培养神经元的影响，并探讨神经元形态改变在肝性脑病发生中的作用。通过对胚胎大鼠大脑神经元的分散培养，结合光镜，透射电镜及免疫组织化学法，观察了氨对分散培养胚鼠大脑神经细胞的影响，发现氨可引起神经元胞体肿胀，尼氏小体溶解，胞质内出现颗粒及空泡变性，甚至突起崩解，核固缩，细胞坏死脱落；电镜下示细胞内内质网，线粒体扩张及囊性变，粗面内质网脱颗粒，大量致密小体出现，突起肿胀，微丝减少；神经微丝蛋白及突触体素的表达减少。实验结果表明，氨对培养神经元具有一定毒性作用，神经元的病变可能影响了其正常功能，促使肝性脑病的发生。