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肝脏和胰腺前体细胞都是由胚胎前肠内胚层细胞发育而来的。脊椎动物中,在高度保守的诱导信号和遗传调节因子作用下,肝脏和胰腺前体细胞特化,并获得器官功能和再生能力。由于对肝脏疾病和Ⅰ型糖尿病有重要的临床价值,肝脏、胰腺的发育和再生机制成为了研究热点。通过对不同模式生物的研究,揭示了进化上保守的诱导信号和转录因子诱导肝脏、胰腺细胞的分化机制,这为干细胞和前体细胞如何诱导分化为肝实质细胞和胰腺β细胞提供了理论依据。 相似文献
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本研究利用TSA（Trichostatin A）、ROS（Roscovitine）、血清饥饿和接触抑制方法处理牛卵丘/颗粒细胞,检测处理前后细胞乙酰化水平、周期分布及其对重组胚发育能力的影响,为提高核移植效率提供理论基础。分别采用上述方法处理牛卵丘/颗粒细胞,首先对处理的细胞形态及活率进行观察,并利用流式分选技术检测处理细胞的周期分布,再通过间接免疫荧光法检测经上述不同处理前后细胞乙酰化水平变化,最后以上述处理细胞作为核供体构建重组胚,比较重组胚发育水平的不同。试验结果显示,经上述处理的卵丘/颗粒细胞形态良好,活率均保持在94%以上;TSA处理卵丘/颗粒细胞后,其乙酰化水平较对照组和其他处理组明显增加（P〈0.05）,经ROS处理的卵丘/颗粒细胞乙酰化表达水平同样高于对照组（P〈0.05）,但仍低于TSA处理组（P〈0.05）,但经血清饥饿处理的卵丘/颗粒细胞乙酰化水平较对照组明显降低（P〈0.05）;利用TSA处理卵丘/颗粒细胞24 h后,细胞被明显抑制在G0/G1期,且较其他处理组的抑制现象更加明显（P〈0.05）;并且,经TSA处理后的卵丘/颗粒细胞充当供体细胞,其卵裂率和囊胚率较对照组明显增加（P〈0.01,（85.2±3.4）%vs（68.6±6.7）%;（30.2±5.7）%vs（10.4±8.3）%）。经TSA处理的牛卵丘/颗粒细胞,与其他处理组相比,乙酰化水平较高,细胞形态良好,细胞周期被明显抑制在G0/G1期,且获得了较高的卵裂率和囊胚率,作为供体细胞的处理方式较为适合。 相似文献
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旨在系统分析伯氏疟原虫感染引起宿主T细胞、NK细胞、Tim-3表达及细胞因子的变化。选取64只雌性C57BL/6小鼠随机分为8组,每组8只,分别于感染后0、4、7、9、11、13、16和19 d获取小鼠脾及外周血免疫细胞,利用流式细胞术检测小鼠主要免疫细胞亚群及免疫检查点分子Tim-3表达水平的变化;同时检测血清中细胞因子的变化。结果表明,感染疟原虫后,小鼠脾CD3+CD4+ T细胞、CD3+CD8+ T细胞及NK细胞的比例均逐渐降低（P<0.01）,且伴随着3种细胞Tim-3表达量的升高（P<0.01）。小鼠外周血CD3+CD4+ T细胞的比例呈先降低后升高趋势,CD3+CD8+ T细胞的比例呈先升高后降低趋势（P<0.05）;小鼠外周血CD3-NK1.1+细胞的比例呈先降低后升高趋势,但感染末期,其比例仍低于未感染组（P<0.05）。Tim-3分子在外周血CD3+CD4+ T细胞、CD3+CD8+ T细胞及CD3-NK1.1+细胞的表达均显著升高（P<0.05）。感染疟原虫后,小鼠血清中促炎细胞因子IL-2的分泌量均显著高于未感染组（P<0.05）;促炎细胞因子IFN-γ、TNF-α和IL-6在血清中分泌均呈先升高后降低趋势（P<0.05）;具有免疫抑制作用的细胞因子IL-10呈逐渐升高趋势,且感染后期急剧升高（P<0.001）。以上结果表明,感染疟原虫后,小鼠的特异性免疫反应发挥了一定的杀伤作用,但由于Tim-3免疫检查点分子及一些发挥免疫抑制作用的细胞因子（IL-10）的过度表达,有利于疟原虫逃避宿主的免疫捕杀作用。该研究提示了从宿主免疫抑制角度研究疟原虫感染的重要性。 相似文献
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Résumé— En plus des kératinocytes, l'épiderme contient des cellules résidentes de morphologie dendritique. Ce sont principalement la cellule de Langerhans, la cellule de Merkel et le mélanocyte. Ces cellules ont des fonctions diverses dans le tégument. Le mélanocyte assure la pigmentation cutanée et la protection contre les radiations U.V., et pourrait intervenir également dans la modulation de l'inflammation cutanée. La cellule de Langerhans intervient dans la surveillance immunologique des surfaces corporelles ecternes. La cellule de Merkel a des fonctions neuroendocrines. Cet article donne un aperçu de la structure et de la fonction de ces trois importantes populations cellulaires dans la peau. [Resident dentritic cells in the epidermis: Langerhans cells, Merkel cells and melanocytes (Cellules dentritiques résidentes de l'épiderme: cellules de Langerhans, cellules de Merkel et mélanocytes). Resumen— La epidermis contiene, además de los queratinocitos, células résidentes de morfologia dendria dendritica. Estas son principalmente las células de Langerhans, las células de Merkel y los melanocitos. Estas células tienen varias funciones en el integumento. Los melanocitos se encargan de la pigmentación y protección de la piel contra la radiación ultravioleta y tarrtbién participan en la regulación de la inflamación cutánea. Las células de Langerhans ayudan en la regulación inmunológica en la superficie externa. Las células de Merkel tienen funciones neuroendocrinas. Esta revisión da un repaso general a la estructura y función de tres importantes células de la piel. [Resident dendsuitic cells in the epidermis: Langerhans cells, Merkel cells and Melanocytes (Células résidentes en la epidermis: células de Langerhans, células de Merkel y melanocitos). Abstract— In addition to the keratinocytes, the epidermis contains resident cells of dendritic morphology. These are principally the Langerhans cell, Merkel cell and melanocyte. These cells have a number of different functions in the integument. The melanocyte is responsible for skin pigmentation and protection against UV radiation, and may also play a role in the modulation of cutaneous inflammation. The Langerhans cell aids in the immunological monitoring of the body's external surfaces. The Merkel cell has neuroendocrine functions. This review gives an overview of the structure and function of these three important cells of the skin. 相似文献
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B.J. Biller A. Guth J.H. Burton S.W. Dow 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(5):1118-1123
Background: Increased numbers of regulatory T cells (Treg) and decreased ratios of CD8+ T cells to Treg have been shown to correlate with decreased survival times (ST) in humans with certain malignancies. A possible connection between Treg and ST in dogs with cancer has not been investigated previously. Hypothesis: The purpose of this study was to compare numbers of Treg and T lymphocyte subsets in dogs with osteosarcoma (OSA) to those of healthy dogs and to determine whether pretreatment values were associated with disease‐free interval or with ST. We hypothesized that Treg numbers would be increased in dogs with cancer and that dogs with a high percentage of Treg would have a poorer prognosis. Animals: Twelve client‐owned dogs with appendicular OSA were entered into a prospective clinical trial. Twenty‐two healthy dogs were used as controls. Methods: The percentages and numbers of Treg and CD4+ and CD8+ T cells in blood, lymph nodes, and tumors were determined with flow cytometry and compared between dogs with OSA and control dogs. Results: Dogs with OSA had significantly fewer circulating CD8+ T cells and significantly more Treg compared with healthy dogs. The CD8/Treg ratio also was significantly lower in dogs with OSA compared with control dogs. In dogs with OSA, a decreased CD8/Treg ratio was associated with significantly shorter STs. Conclusions: These data support a role for Treg in the immune control of canine OSA and suggest that determination of the CD8/Treg ratio may be useful for assessing outcomes. 相似文献
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采用方瓶存放BHK21细胞悬液,在2℃～8℃冰箱存放不同时间后,按常规方法进行细胞复苏和传代。对比存放不同时间后细胞复苏时的驯化次数、细胞数量和细胞活力,寻求最佳存放时间和复苏代次以指导生产。同时将2℃～8℃冷藏保存方法与液氮冻存细胞方法在细胞复苏周期和达到所需扩繁细胞数方面进行比较。结果表明,方瓶冷藏保存BHK21细胞悬液最长可存放60d,经2—5代驯化后,细胞形态和活力恢复正常,细胞数量与收悬液前细胞数量无显著差异,并能稳定传20代以上。与液氮冻存细胞方法相比,该方法在快速恢复细胞产量时有较大优势,在生产周期紧张的情况下可作为辅助方法保障细胞传代的延续。 相似文献
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K. O'Neill A. Guth B. Biller R. Elmslie S. Dow 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(4):875-881
Background: Regulatory T cells (Treg) have been shown to suppress antitumor immunity and often are increased in humans and rodents with cancer. However, Tregs have not been well studied in dogs with cancer and it is not known if certain tumor types are associated with increased Tregs.
Hypothesis: We hypothesized that Treg percentages would be increased in dogs with cancer and that Treg percentages would be higher in dogs with certain types of cancer.
Animals: The percentages and numbers of Tregs and nonregulatory T cells and B cells were assessed in 34 dogs with cancer and 9 age-matched control dogs. Dogs evaluated included 14 dogs with sarcoma, 7 dogs with carcinoma, 7 dogs with lymphoma, and 6 dogs with mast cell tumor.
Methods: Numbers and percentages of Tregs, CD4+ , and CD8+ T cells and B cells were determined using flow cytometry and compared between control dogs and dogs with cancer.
Results: The percentage of Tregs was significantly increased overall in dogs with cancer compared with control dogs. When tumor types were compared, Treg percentages were significantly increased in dogs with carcinoma. The Treg/CD8 T cell ratio was significantly higher in dogs with cancer compared with control dogs and was also significantly increased in 2 dogs with T-cell lymphoma.
Conclusions: Treg percentages in blood were increased in dogs with cancer, particularly in dogs with carcinoma. The Treg/CD8 ratio also identified tumor-specific abnormalities in dogs with cancer. These findings indicate that tumor-specific factors may affect Tregs in dogs. 相似文献
Hypothesis: We hypothesized that Treg percentages would be increased in dogs with cancer and that Treg percentages would be higher in dogs with certain types of cancer.
Animals: The percentages and numbers of Tregs and nonregulatory T cells and B cells were assessed in 34 dogs with cancer and 9 age-matched control dogs. Dogs evaluated included 14 dogs with sarcoma, 7 dogs with carcinoma, 7 dogs with lymphoma, and 6 dogs with mast cell tumor.
Methods: Numbers and percentages of Tregs, CD4
Results: The percentage of Tregs was significantly increased overall in dogs with cancer compared with control dogs. When tumor types were compared, Treg percentages were significantly increased in dogs with carcinoma. The Treg/CD8 T cell ratio was significantly higher in dogs with cancer compared with control dogs and was also significantly increased in 2 dogs with T-cell lymphoma.
Conclusions: Treg percentages in blood were increased in dogs with cancer, particularly in dogs with carcinoma. The Treg/CD8 ratio also identified tumor-specific abnormalities in dogs with cancer. These findings indicate that tumor-specific factors may affect Tregs in dogs. 相似文献
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本试验旨在体外分离培养兔子宫内膜细胞(腺上皮细胞和基质细胞)和平滑肌细胞,并且探讨纯化子宫内膜上皮细胞和基质细胞的方法。用差速离心法和差速贴壁法获得纯化的子宫内膜上皮细胞和基质细胞,用滤网法分离得到子宫平滑肌细胞,分别在添加20%胎牛血清(FBS)、100μg/mL牛胰岛素、63.5 nmol/L雌二醇(E2)、7.14nmol/L孕酮(P4)的DMEM/F12(1∶1)培养液和37℃5%CO2的饱和湿度条件下培养;用免疫组化和免疫荧光法鉴定细胞并检测分离的细胞纯度。结果表明用该方法成功地分离培养了兔子宫内膜上皮细胞和基质细胞,且2种细胞纯度都达98%左右,基质细胞出现蜕膜化;子宫平滑肌细胞的纯度为97%左右,而且出现横纹状的生长。本研究表明子宫内膜细胞和平滑肌细胞能够在体外成功培养;在含20?S、100μg/mL牛胰岛素、63.5 nmol/L E2、7.14 nmol/L P4的DMEM/F12(1∶1)培养液和37℃5%CO2饱和湿度的培养条件下最有利于体外培养的子宫内膜细胞和平滑肌细胞的生长。 相似文献
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S Apichela MA Jiménez‐Díaz M Roldan‐Olarte JN Valz‐Gianinet DC Miceli 《Reproduction in domestic animals》2009,44(6):943-951
Sperm reservoirs in South American Camelids would be crucial for successful fertilization. Since ovulation occurs approximately 36 h after mating, the maintenance of the sperm viability in the oviduct waiting for the ovum is a critical reproductive event. Our study aimed at determining whether the isthmus or the utero tubal junction (UTJ) could function as a sperm reservoir in llama by means of in vivo and in vitro experiments. For the in vivo experiments, the oviducts of adult females with a dominant follicle bigger than 7 mm were examined for the presence of sperm at 6, 18, 24, 28 and 35 h after mating. The results using scanning and transmission electron microscopy showed ultrastructural differences between isthmus and UTJ with respect to (1) predominance of secretory cells in the UTJ and ciliated cells in the isthmus epithelium and (2) cytoplasmic bulbous projection of the secretory cells in the UTJ. Sperm adhered by a mucus‐like substance were seen only in the UTJ at 6, 18, 24 and 28 h post‐mating. Lack of sperm adhered to oviductal mucosa was observed around ovulation (35 h). In vitro experiments demonstrated higher ability of UTJ epithelial cell explants with respect to isthmus explants to bind sperm in a co‐cultured system. The anatomical features and the presence of a sperm bonding agent in the UTJ together with the in vitro differential binding of sperm to UTJ explants strongly suggest that both may be feasible mechanisms that facilitate sperm storage in this oviductal region in llama. 相似文献
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Infections with gastrointestinal nematodes represent a major problem for human health and animal health and production. The physical size of the parasite, its changing life-cycle stages and the relative inaccessibility to host cells pose unique challenges to the immune system, which has evolved specialized strategies for parasite control. This paper reviews the work performed in the authors' laboratories to identify components that are involved in the natural rejection response against ruminant gastrointestinal nematode parasites, in particular Haemonchus contortus in sheep. The results of these studies indicate that stage-specific antibodies act in concert with effector cells, in particular globular leukocytes (intraepithelial mast cells) and eosinophils, appropriately activated/primed by type 2 (T2) cytokines, to initiate different mechanisms of parasite expulsion and killing. In addition, other molecules, in particular carbohydrate binding galectins, may be involved in strengthening the final effector phase of the rejection response. 相似文献
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为探究不同直径有腔卵泡中猪卵巢颗粒细胞的生理机能差异,以期为后续生殖毒理学研究奠定基础。采用剖剪法获取猪卵巢内三种直径范围的有腔卵泡（小型〈2mm,中型2-5mm,大型≥5mm）并获得颗粒细胞,台盼蓝染色方法计算细胞存活率,倒置显微镜下观察细胞形态并计算细胞纯度,实时定量方法检测促卵泡刺激素受体基因（FSHR）及促黄体生成素受体基因（LHR）的表达进一步鉴定颗粒细胞,四甲基偶氮唑蓝（MTT）法测定细胞生长曲线。结果显示从大中小三种不同直径有腔卵泡中获得的猪卵巢颗粒细胞存活率分别为68%、75%、72%,纯度分别为97%、95%、90%;细胞生长曲线表明,从24h开始进入对数生长期,并于120h达到最大值,且中型卵泡中获得的颗粒细胞生长增殖状态最佳;实时定量结果显示FSHR在猪三种直径的有腔卵泡颗粒细胞中均表达阳性,且呈现差异。 相似文献
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探讨橙皮苷对3种霉菌毒素处理的HepG2细胞增殖和迁移作用的影响。采用MTT、Griess、细胞划痕愈合试验分别检测细胞活力、细胞分泌NO、细胞迁移率。结果3种毒素对HepG2细胞增殖的影响随毒素浓度的增加呈现先促进后抑制的作用,低浓度DON、OTA(0.04μmol/L和0.08μmol/L),ZEN(<2μmol/L)显著提高HepG2细胞活力及促进增殖,高浓度霉菌毒素明显降低HepG2细胞活力及抑制细胞增殖。与霉菌毒素组比较,橙皮苷组HepG2细胞活力降低及增殖减弱,表示橙皮苷能缓解霉菌毒素对细胞的毒性。与空白对照组比较,霉菌毒素组HepG2分泌NO量显著降低,不同浓度及不同霉菌毒素对NO分泌没有明显影响;与霉菌毒素组比较,橙皮苷组不同浓度DON处理的细胞分泌NO差异不显著。低浓度DON毒素(0.08μmol/L^2μmol/L)处理HepG2细胞24、36、48 h后,DON毒素能极显著促进HepG2细胞迁移,随着霉菌毒素对细胞处理时间延长细胞迁移快,而高浓度DON毒素(10μmol/L、50μmol/L)对促细胞迁移影响显著低于低浓度DON。结果低浓度DON霉菌毒素促进HepG2细胞增殖及迁移,表明DON毒素对HepG2具有潜在的致癌性,橙皮苷能抑制HepG2细胞增殖及缓解霉菌毒素毒性的作用。 相似文献
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Veslemy Myhruold 《Acta veterinaria Scandinavica》1980,21(2):291
The cryoprotection of the sheep erythrocyte intermediate EAC4 cells, used as reagent in titration of the first complement component, Gl, was investigated. The cryoprotective agents tested were untreated polyvinylpyrrolidone (PVP), purified PVP, neutralized PVP and a hydroxyethylated potato starch of high viscosity, Avelex 1030, hydrolyzed for 40 min. Recovery of EAG4 cells after thawing was 80–90 %, with best results using untreated, purified or neutralized PVP. The EAG4 cells frozen in the presence of untreated PVP showed, however, increased susceptibility to the hemolytic action of Gl, whereas cells frozen with purified or neutralized PVP or with Avelex 1030 gave titers similar to that obtained with fresh cells. Gl titrations with frozen and thawed EAG4 cells gave more reproducible results than those obtained when titrations were performed with fresh separately prepared cells. 相似文献