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1.
Wilms瘤1基因在肾小管上皮细胞转分化中的表达及作用   总被引:11,自引:0,他引:11       下载免费PDF全文
目的 探讨Wilms 肿瘤1基因(WT1)在肾小管上皮细胞(TEC)向肌成纤维细胞转分化中的可能作用。方法 将体外原代培养TEC分别置含IL-1α(10 ng/ml)、 IL-1α+抗WT1中和抗体(10 μg/ml)的DMEM/F12培养基中培养, 观察TEC的形态变化及免疫学特征。采用RT-PCR检测各组TEC中WT1及α-SMA的表达。结果 经IL-1α掺入培养5 d后,体外培养的TEC形态特征趋于成纤维细胞化,细胞拉长、梭形变,失去原有的呈铺路石样的生长方式。电镜下细胞极性丧失,表面微绒毛消失。正常情况下,成年TEC不表达WT1。经IL-1α掺入培养1 d后,TEC重新表达WT1,同时伴有α-SMA的表达;3 d后WT1表达消失,呈一过性特征,而α-SMA的表达则随时间的延长而逐渐增强。在培养中掺入抗WT1抗体以中和WTl基因产物后,尽管仍给予IL-1α刺激,TEC大都保持原有特征不变,α-SMA及WT1 mRNA仅呈微弱表达。结论 高浓度IL-1α可导致TEC向肌成纤维细胞的转分化。在TEC的转分化过程中,WT1基因的重新、一过性表达可能起着重要作用。成年TEC重新获得WT1表达,可能是其发生转分化的内在启动机制。体外中和WT1的基因产物可明显抑制TEC的转分化进程,并可能籍此影响肾脏的纤维化发生。  相似文献
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骨成形蛋白7对人肾小管上皮细胞增殖和转分化的影响   总被引:8,自引:1,他引:7  
目的观察骨成形蛋白7(BMP-7)对TGF-β1诱导的人肾小管上皮细胞转分化的影响,以探讨其延缓小管间质纤维化病变的作用及其可能机制。方法将体外培养的人肾小管上皮细胞分为空白对照组、TGF-β1组、TGF-β1 50ng/mlBMP-7组、TGF-β1 100ng/mlBMP-7组。应用MTT比色法测定BMP-7对人肾小管上皮细胞增殖的作用;间接免疫荧光法测定人肾小管上皮细胞α-SMA、角蛋白、波形蛋白的表达;流式细胞仪检测表达α-SMA阳性的HK-2细胞百分率;RT-PCR检测细胞中α-SMAmRNA的表达。结果与空白对照组相比,不同浓度的BMP-7处理HK-2细胞24、48h后,HK-2细胞均明显增殖(P<0.05)。免疫荧光检测结果显示,经TGF-β1刺激后,角蛋白表达减弱,α-SMA和波形蛋白表达增强;加入50ng/mlBMP-7处理24、48h后,细胞中α-SMA和波形蛋白表达减弱。流式细胞仪检测发现,加入50ng/mlBMP-7处理24、48h后,表达α-SMA的HK-2细胞阳性率逐渐下降,与TGF-β1处理组相比差异有显著性意义(P<0.05)。RT-PCR结果显示,空白对照组无α-SMAmRNA表达,5ng/mlTGF-β1组与空白对照组相比,α-SMAmRNA表达明显上调(P<0.05),而TGF-β1 50ng/mlBMP-7组、TGF-β1 100ng/mlBMP-7组与TGF-β1组相比,α-SMAmRNA表达有下降趋势,但无显著性差异(P>0.05)。结论TGF-β1促进肾小管上皮细  相似文献
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The hallmark of failing renal transplants is tubular atrophy and interstitial fibrosis (TA/IF). Injury to tubular epithelial cells (TEC) could contribute to fibrogenesis via epithelial-mesenchymal transition (EMT). We examined the features of EMT in renal transplants that developed TA/IF. Biopsies from 10 allograft kidneys with impaired function and TA/IF and 10 biopsies from transplants with stable function were compared to their implantation biopsies. Relative to implantation biopsies, TEC in TA/IF kidneys showed loss of epithelial markers (E-cadherin, cytokeratin) with altered distribution. Some TEC also showed new cytoplasmic expression of mesenchymal markers vimentin, S100A4, and alpha smooth muscle actin (alpha-SMA) and collagen synthesis marker heat shock protein (HSP-47), both in deteriorating and atrophic tubules. Double immunostaining showed coexpression of cytokeratin and vimentin, S100A4 and HSP-47, indicating intermediate stages of EMT in TA/IF. These changes were absent or much less in transplants with stable function. EMT features in the TA/IF group correlated with serum creatinine (vimentin, S100A4, HSP-47), history of T-cell-mediated rejection (cytokeratin, S100A4) and proteinuria (cytokeratin). These findings support a model in which the TEC damage induces loss of epithelial features and expression of fibroblast features, as a common pathway of deterioration by either immunologic or nonimmunologic processes.  相似文献
5.
脂肪干细胞向表皮细胞表型转分化的研究   总被引:5,自引:0,他引:5  
目的探讨脂肪干细胞(adipose-derivedstemcells,ADSCs)跨胚层向表皮细胞表型转分化的可能性。方法取大鼠脂肪组织,用酶消化法分离、培养ADSCs,用免疫细胞化学法、流式细胞仪法鉴定ADSCs。实验分为皮肤匀浆条件培养基诱导7d组;皮肤匀浆条件培养基加入EGF(20ng/ml)诱导7d组;皮肤匀浆条件培养基诱导4d,撤条件培养基,改10?S/DMEM培养3d组;10?S/DMEM为对照组。诱导后经流式细胞仪检测CK19、CK10的表达。结果①免疫细胞化学分析表明ADSCs表达CD49d,而不表达CD106、CD34、CK19、CK10;流式细胞仪检测CD49d、CD44的阳性率分别为94.32%、90.38%。②各诱导实验组细胞CK19阳性率分别为45.32%、26.58%、23.37%,CK10阳性率分别为43.56%、25.54%、18.20%,较对照组CK19阳性率18.53%、CK10阳性率2.46%,明显增高(P<0.01),差异有统计学意义。结论皮肤匀浆液可以诱导ADSCs向表皮细胞表型转分化。  相似文献
6.
己酮可可碱对肾小管上皮细胞转分化抑制作用的实验研究   总被引:4,自引:1,他引:3  
目的:探讨己酮可可碱(PTX)对单侧输尿管梗阻(UUO)模型大鼠肾间质平滑肌肌动蛋白(α-SMA)表达的影响,并在体外研究其对肾小管上皮细胞转分化及其对Smad 7表达的作用.方法:将实验大鼠分为假手术组、UUO对照组和UUO PTX治疗组.用免疫组化法测定各组动物肾组织α-SMA表达.体外培养的人肾小管上皮细胞(HK-2),经TGF-β1及PTX干预后,用蛋白印迹检测α-SMA和Smad 7表达,用ELISA检测培养上清中Ⅰ型胶原含量.结果:假手术组大鼠肾组织仅血管壁α-SMA免疫染色阳性.UUO对照组第3 d、第7 d、第14 d,α-SMA表达程度分别为(2.90±0.71)%、(8.50±0.97)%、(17.9±2.70)%,PTX治疗组则分别为(2.70±0.62)%、(6.90±0.83)%、(13.8±1.9)%,术后第7 d(P<0.05)、第14 d(P<0.01)两组有统计学差异.TGF-β1(8 ng/ml)刺激HK-2细胞72 h后,α-SMA表达强度为(87.7±7.0)%,培养上清中Ⅰ型胶原浓度为(2 560.49±95.03) ng/ml;而加入PTX 10、50、100、300、500 μg/ml干预72 h后,α-SMA表达强度(F=174.998,P<0.001)和培养上清中的Ⅰ型胶原(F=460.883,P<0.001)呈浓度依赖性减少.在TGF-β1刺激前24 h、TGF-β1刺激后0 h、12 h、24 h、36 h或48 h后分别加入PTX(500 μg/ml),α-SMA表达强度(F=144.131,P<0.001)和培养上清中的Ⅰ型胶原(F=444.557,P<0.001)则呈时间依赖性减少.TGF-β1刺激的同时,分别加入PTX 10、50、100、300、500 μg/ml干预72 h后,Smad 7表达强度分别为(50.6±3.1)%、(49.4±2.9)%、(48.9±2.5)%、(51.4±1.8)%、(49.5±3.0)%,与阳性对照组(46.9±3.5)%比较无统计学差异(P>0.05).结论:(1)PTX可减少UUO大鼠肾间质α-SMA表达;(2)在体外,PTX可抑制TGF-β1诱导的肾小管上皮细胞转分化,该作用与Smad 7表达无关,其机制有待于进一步研究.  相似文献
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Adult bone marrow-derived stem/progenitor cells have traditionally been considered to be tissue-specific cells with limited capacity for differentiation. However, recent discoveries have generated tremendous excitement regarding possible applications of stem cells, particularly bone marrow-derived stem cells, in the treatment of human diseases. The potential ability to regenerate cells of various different lineages has raised the therapeutic possibility of using these bone marrow-derived stem cells as a source of cells for tissue repair and regeneration. Tissue engineering is a rapidly expanding interdisciplinary field aimed at restoring function to tissues through the delivery of constructs which become integrated into the patient. The use of bone marrow-derived stem cells provides a less invasive source for cells applicable to tissue engineering, including cardiovascular tissues such as heart valves, blood vessels, and myocardium. Although these strategies are in the early stages of development, they are conceptually promising and offer important insights into the future treatment of various cardiovascular ailments.  相似文献
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BACKGROUND:Glomerular cellular crescents consist of epithelial cells and macrophages, which can undergo an irreversible process of fibrous organization. However, the origin of the fibroblast-type cells that mediate this fibrous organization is unclear. METHODS: This study examined glomerular epithelial- myofibroblast transdifferentiation (GEMT) in the formation and evolution of glomerular crescents in two distinct rat models of glomerulonephritis: 5/6 nephrectomy and antiglomerular basement membrane (GBM) disease. RESULTS: Early in the course of both disease models, and prior to crescent formation, immunohistochemistry staining and in-situ hybridization demonstrated de novo expression of alpha-smooth-muscle actin (alpha-SMA), a marker of smooth muscle cells and myofibroblasts, by glomerular parietal epithelial cells (GPEC). The expression of alpha-SMA by GPEC was accompanied by a loss of E-cadherin staining, a marker of epithelial cells. At this early stage of GEMT, ultrastructural studies identified the presence of characteristic actin microfilaments and dense bodies within GPEC which retained a normal epithelial morphology with apical-basal polarity and microvilli. A late stage of transdifferentiation was seen in fibrocellular crescents. In this case, GPEC attached to intact segments of the capsular basement membrane contained large bundles of actin microfilaments throughout the cell, and this was accompanied by a loss of polarity, microvilli, and tight junctions. There was a significant correlation between the presence of alpha-SMA(+) GPEC and glomerular crescent formation. Cellular crescents contained small numbers of alpha-SMA(+) myofibroblasts. These cells become the dominant population in fibrocellular crescents, which was associated with marked local proliferation. Relatively few alpha-SMA(+) myofibroblasts remained in fibrotic/organizing crescents. Most cells within cellular and fibrocellular crescents expressed transforming growth factor-beta (TGF-beta) and basic fibroblast growth factor (FGF-2), suggesting that these growth factors may regulate this GEMT process during the evolution of glomerular crescents. CONCLUSIONS: This study provides the first phenotypic and morphological evidence that glomerular epithelial-myofibroblast transdifferentiation participates in the formation and evolution of glomerular crescents.  相似文献
9.
黄芪通过c-met调控TGF-β1诱导的肾小管上皮细胞转分化   总被引:3,自引:1,他引:2  
AB 目的:探讨黄芪对TGF-β1诱导的肾小管上皮细胞转分化及细胞外基质分泌的作用及机制。方法:体外培养正常大鼠肾小管上皮细胞(NRK52E),应用倒置相差显微镜观察NRK52E细胞形态学变化;免疫组织化学染色法及实时荧光定量PCR法检测α-平滑肌肌动蛋白(α-SMA),肝细胞生长因子HGF受体(c-met)的表达;ELISA法定量检测细胞上清液中胶原Ⅰ(Col-Ⅰ),胶原Ⅲ(Col-Ⅲ)和纤维黏连蛋白(FN)的水平。结果:TGF-β1可诱导肾小管上皮细胞肌成纤维细胞转分化(TEMT),TGF-β1诱导组细胞肥大、拉长,呈长梭形,α-SMA表达明显增强,Col-Ⅰ、Col-Ⅲ和FN分泌增加(P〈0.05)。加入不同浓度黄芪后,细胞形态接近正常肾小管上皮细胞形态,α-SMA表达、Col-Ⅰ、Col-Ⅲ和FN分泌均较TGF-β1诱导组明显抑制(P〈0.05),c-met表达较TGF-β1诱导组增加(P〈0.05)且呈剂量依赖性。结论:TGF-β1可以诱导肾小管上皮细胞肌成纤维细胞转分化,增加细胞外基质成分Col-Ⅰ、Col-Ⅲ和FN的分泌;黄芪能够抑制TGF-β1诱导的NRK52E细胞转分化以及细胞外基质的分泌;黄芪抑制细胞转分化的机制可能与其增强c-met的表达有关。  相似文献
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目的:通过研究姜黄素(curcumin,Cur)对转化生长因子-β1(TGF-β1)诱导人肾小管上皮细胞(HK-2)转分化及分泌细胞外基质(ECM)成分的影响,探讨姜黄素在防治肾小管-间质纤维化方面可能的作用机制。方法:应用不同浓度Cur处理经TGF-β1诱导活化的HK-2细胞,通过显微镜观察细胞形态改变,免疫组化技术检测α-平滑肌肌动蛋白(α-SMA)和E-钙黏蛋白(E-cadherin)的表达;应用酶联免疫吸附法(ELISA)检测细胞培养上清Ⅰ型胶原(ColⅠ)、Ⅲ型胶原(ColⅢ)和纤连蛋白(FN)的分泌。结果:(1)正常HK-2细胞表达E-cadherin,不表达α-SMA,经TGF-β1刺激后细胞表型发生转变,E-cadherin的表达明显减弱,α-SMA表达明显增强;(2)不同浓度Cur组与单纯TGF-β1刺激组相比α-SMA的表达有所减弱,而E-cadherin的表达增强;(3)不同浓度Cur抑制了ColⅠ、ColⅢ和FN的分泌,与单纯TGF-β1刺激组相比有统计学差异(P〈0.05)。结论:姜黄素能抑制TGF-β1诱导人肾小管上皮细胞转分化及细胞外基质成分ColⅠ、ColⅢ和FN的合成,在一定程度上具有防治肾小管-间质纤维化的作用。  相似文献
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