• 【纤连蛋白促进人角膜成纤维细胞介导的胶原凝胶收缩。】 复制标题 收藏 收藏
    DOI:10.1016/j.exer.2006.06.008 复制DOI
    作者列表:Liu Y,Yanai R,Lu Y,Kimura K,Nishida T
    BACKGROUND & AIMS: :Collagen contraction mediated by corneal fibroblasts (CFs) is implicated in the maintenance of corneal shape. Given that fibronectin is expressed at sites of corneal stromal wounding, we investigated the effect of fibronectin on CF-mediated collagen gel contraction. Human CFs were cultured in a three-dimensional gel of type I collagen in the absence or presence of various extracellular matrix (ECM) components. The contraction of collagen gels mediated by CFs was evaluated by measurement of changes in gel diameter. The formation of stress fibers and focal adhesions in CFs was examined by fluorescence microscopy. The abundance of paxillin, phosphorylated paxillin, integrins alpha5, beta1, and alpha2, and alpha-smooth muscle actin in CFs was examined by immunoblot analysis. Fibronectin promoted CF-mediated collagen gel contraction in a concentration- and time-dependent manner. Other ECM proteins or glycosaminoglycans did not exhibit such an effect. Fibronectin also induced cell spreading, the formation of stress fibers, and the establishment of focal adhesions containing paxillin in CFs cultured in three-dimensional collagen gels. In addition, it increased the amounts of paxillin, phosphorylated paxillin, and integrins alpha5 and beta1 in these cells. The expression of integrin alpha2 and alpha-smooth muscle actin was not affected by fibronectin, however. Furthermore, the peptide GRGDSP (an antagonist of fibronectin receptors) blocked the stimulatory effect of fibronectin on CF-mediated collagen gel contraction. These results suggest that fibronectin promoted CF-mediated collagen gel contraction in a manner dependent on the formation of stress fibers and focal adhesions, the activation of paxillin, and the up-regulation of integrin alpha5beta1. Fibronectin may therefore contribute to the maintenance of corneal shape by CFs during the healing of stromal wounds.
    背景与目标: :角膜成纤维细胞(CFs)介导的胶原蛋白收缩与维持角膜形状有关。鉴于纤连蛋白在角膜基质损伤的部位表达,我们研究了纤连蛋白对CF介导的胶原凝胶收缩的影响。在不存在或存在各种细胞外基质(ECM)成分的情况下,将人CFs在I型胶原蛋白的三维凝胶中培养。通过测量凝胶直径的变化来评估CFs介导的胶原蛋白凝胶的收缩。 CFs中应力纤维的形成和粘着斑通过荧光显微镜检查。通过免疫印迹分析检查了CF中的Paxillin,磷酸化Paxillin,整合素α5,β1和α2以及α平滑肌肌动蛋白的含量。纤连蛋白以浓度和时间依赖性方式促进CF介导的胶原蛋白凝胶收缩。其他ECM蛋白或糖胺聚糖没有表现出这种作用。纤连蛋白还可以在三维胶原蛋白凝胶中培养的CF中诱导细胞扩散,形成应力纤维以及建立含有帕西林的粘着斑。此外,它增加了这些细胞中的Paxillin,磷酸化Paxillin和整合素alpha5和beta1的量。但是,整联蛋白α2和α平滑肌肌动蛋白的表达不受纤连蛋白的影响。此外,肽GRGDSP(纤连蛋白受体的拮抗剂)阻断了纤连蛋白对CF介导的胶原凝胶收缩的刺激作用。这些结果表明纤连蛋白促进CF介导的胶原蛋白凝胶收缩的方式取决于应激纤维的形成和粘着斑,paxillin的激活以及整联蛋白alpha5beta1的上调。因此,纤连蛋白可能在基质伤口愈合过程中通过CF维持角膜形状。
  • 【细胞质基因表达系统提高了阳离子脂质体介导的体内基因向小鼠脑内转移的效率。】 复制标题 收藏 收藏
    DOI:10.1006/bbrc.1997.6568 复制DOI
    作者列表:Mizuguchi H,Nakagawa T,Morioka Y,Imazu S,Nakanishi M,Kondo T,Hayakawa T,Mayumi T
    BACKGROUND & AIMS: Development of methodologies for gene transfer into the central nervous system (CNS) is important for fundamental research as well as clinical studies for gene therapy. Cationic liposomes (CL) are attractive vectors because of their safety and ease of use. However, to date only low rates of success have been reported. We succeeded in obtaining high transfection efficiencies into the newborn mouse brain in vivo by CL and a cytoplasmic gene expression system based on T7 RNA polymerase and T7 RNA polymerase- and the luciferase-gene with the T7 promoter sequence. This system showed an efficiency rate 2 orders of magnitude higher than the standard system, which used CL and luciferase genes with a Rous sarcoma virus promoter, pRSVL. In addition, in vitro experiments using LLCMK2 cells showed that cytoplasmic gene expression occurred rapidly (within 6 h) after transfection. In contrast, pRSVL required 24-48 h for induction of luciferase expression. Our results suggest that the cytoplasmic gene expression system is useful for gene delivery into the CNS.

    背景与目标: 基因转移到中枢神经系统(CNS)的方法学的发展对于基础研究以及基因治疗的临床研究都很重要。由于阳离子脂质体(CL)的安全性和易用性,它们是有吸引力的载体。然而,迄今为止,仅报道了低成功率。我们成功地通过CL和基于T7 RNA聚合酶和T7 RNA聚合酶以及荧光素酶基因(具有T7启动子序列)的细胞质基因表达系统,成功地在体内获得了新生小鼠大脑的高转染效率。该系统的效率比标准系统高2个数量级,后者使用带有Rous肉瘤病毒启动子pRSVL的CL和荧光素酶基因。此外,使用LLCMK2细胞的体外实验显示,转染后(6小时内)细胞质基因表达迅速发生。相比之下,pRSVL需要24-48小时才能诱导萤光素酶表达。我们的结果表明,胞质基因表达系统可用于将基因传递到中枢神经系统。

  • 【阳离子脂质体介导的人免疫缺陷病毒1型Tat蛋白进入细胞的摄取。】 复制标题 收藏 收藏
    DOI:10.1016/s0166-0934(97)00070-0 复制DOI
    作者列表:Fong SE,Smanik P,Smith MC,Jaskunas SR
    BACKGROUND & AIMS: The human immunodeficiency virus type 1 (HIV-1) Tat protein strongly transactivates gene expression from the viral long terminal repeat (LTR) and is required for virus efficient replication. Previous studies have shown that cells scrape-loaded in the presence of purified recombinant Tat can absorb the protein in a receptor-independent fashion. Using recombinant Tat in which cysteine residues were blocked by sulfitolysis to prevent disulfide aggregation (S-Tat) we were unable to observe this phenomenon, possibly because of improper protein folding. In this study we report that the block to cellular uptake could be overcome by mixing S-Tat with a cationic liposome, Lipofectin. When mixed with Lipofectin, S-Tat effected a specific, concentration-dependent transactivation of HIV-1 LTR-directed reporter gene activity in Hela Cells. Cellular uptake was confirmed by Western blot analysis with an anti-Tat antibody. The method described utilizes cells plated in a 96-well format, requires only nanogram quantities of S-Tat protein and is much less labor-intensive than assays involving scrape-loading, making it suitable for use as a high-throughput screen for detecting Tat inhibitors. The method may have applications for the analysis of other recombinant proteins that require uptake into intact cells for determination of functionality and presents a general technique for introducing exogenous proteins into cells.

    背景与目标: 人类免疫缺陷病毒1型(HIV-1)Tat蛋白可以强烈地激活病毒长末端重复序列(LTR)的基因表达,并且是病毒有效复制所必需的。先前的研究表明,在纯化的重组Tat存在下,被刮擦的细胞可以以不依赖受体的方式吸收蛋白质。使用重组Tat,其中半胱氨酸残基被亚硫酸盐分解作用阻止,以防止二硫键聚集(S-Tat),我们无法观察到这种现象,这可能是由于蛋白质折叠不当所致。在这项研究中,我们报道通过将S-Tat与阳离子脂质体Lipofectin混合可以克服对细胞摄取的阻碍。与Lipofectin混合后,S-Tat在Hela细胞中实现了HIV-1 LTR指导的报告基因活性的特异性,浓度依赖性的反式激活。用抗Tat抗体通过蛋白质印迹分析确认了细胞摄取。所描述的方法利用以96孔格式铺板的细胞,仅需纳克量的S-Tat蛋白,并且比涉及刮擦试验的劳动强度低得多,使其适合用作检测Tat的高通量筛选抑制剂。该方法可用于分析其他重组蛋白质,这些蛋白质需要摄取完整的细胞来确定功能性,并提出了将外源蛋白质引入细胞的一般技术。

  • 【一项对儿童进行i-gel和喉罩Supreme气道比较的随机等效试验。】 复制标题 收藏 收藏
    DOI:10.1111/pan.12078 复制DOI
    作者列表:Jagannathan N,Sommers K,Sohn LE,Sawardekar A,Shah RD,Mukherji II,Miller S,Voronov P,Seraphin S
    BACKGROUND & AIMS: BACKGROUND:The laryngeal mask airway Supreme (Supreme) is a new single-use supraglottic device with gastric access capability now available in all sizes for children. OBJECTIVES:To compare the i-gel with the Supreme in children for routine airway maintenance. MATERIALS/METHODS:One hundred and seventy children, aged 3 months to 11 years, 5-50 kg in weight, were randomly assigned to receive either the i-gel or the Supreme. The primary outcome measured was airway leak pressure. Secondary outcomes included the following: ease and time for insertion, insertion success rate, fiberoptic grade of view, ease of gastric tube placement, number of airway manipulations, quality of airway during anesthetic maintenance, and complications. RESULTS:A total of 168 patients were assessed for the outcomes. The median (IQR [range]) airway leak pressure for the i-gel was higher than with the Supreme, 20 (18-25 [9-40]) cm H(2)O vs 17 (14-22 [10-40]) cm H(2)O, respectively (P = 0.001). There were no differences in the time for device insertion, fiberoptic grade of view, quality of airway, and complications. Median (IQR[range]) time of successful insertion of a gastric tube was faster with the Supreme, 12 (9.2-14.3 [5.2-44.2]) s than with the i-gel, 14 (11.9-19 [6.9-75]) s; P = 0.01. The number of airway manipulations during placement was higher with the i-gel than with the laryngeal mask airway Supreme (12 vs 13 patients), P = 0.02. CONCLUSIONS:In infants and children, when a single-use supraglottic device with gastric access capabilities is required, the i-gel demonstrated higher airway leak pressures and can be a useful alternative to the Supreme.
    背景与目标: 背景:喉罩气道“至尊”(Supreme)是一种新型的具有胃道通行功能的一次性声门上装置,目前可用于各种尺寸的儿童。
    目的:比较i-gel和Supreme在儿童常规气道维护中的作用。
    材料/方法:随机分配3个月至11岁,体重5-50公斤的一百零七名儿童接受i-gel或Supreme。测得的主要结果是气道泄漏压力。次要结果包括以下几项:插入的容易程度和时间,插入成功率,光纤的视线等级,胃管放置的容易程度,气道操作的次数,麻醉剂维持期间气道的质量以及并发症。
    结果:共评估了168例患者的预后。 i-gel的中位(IQR [范围])气道泄漏压力高于Supreme,20(18-25 [9-40])cm H(2)O vs 17(14-22 [10-40 ])cm H(2)O分别(P = 0.001)。在设备插入时间,光纤视线等级,气道质量和并发症方面没有差异。 Supreme插入胃管的中位数(IQR [range])时间在Supreme的情况下为12(9.2-14.3 [5.2-44.2])s,而在i-gel的情况下则为14(11.9-19 [6.9-75])。 )s; P = 0.01。 i-gel放置期间气道操纵的次数比喉罩Supreme气道操纵者高(12例vs 13例),P = 0.02。
    结论:在婴幼儿中,当需要一次性使用具有胃通路功能的声门上装置时,i-gel表现出较高的气道渗漏压力,可以作为Supreme的有用替代品。
  • 【冷却塔中的嗜肺军团菌:计数波动,通过脉冲场凝胶电泳(PFGE)确定遗传变异性以及PFGE模式的持久性。】 复制标题 收藏 收藏
    DOI:10.1128/AEM.00066-07 复制DOI
    作者列表:Ragull S,Garcia-Nuñez M,Pedro-Botet ML,Sopena N,Esteve M,Montenegro R,Sabrià M
    BACKGROUND & AIMS: :The concentrations of Legionella pneumophila in cooling towers may vary considerably over short periods of time, producing significant fluctuations throughout the year. Despite genetic variability, in small geographical areas the same indistinguishable pulsed-field gel electrophoresis patterns may be shared among different cooling towers and persist over time.
    背景与目标: :冷却塔中嗜肺军团杆菌的浓度在短时间内可能会发生很大变化,全年会产生明显的波动。尽管遗传变异,在较小的地理区域中,相同的难以区分的脉冲场凝胶电泳图谱可能会在不同的冷却塔之间共享并随着时间的流逝而持续存在。
  • 【聚焦超声在凝胶隧道中微泡的空化阈值。】 复制标题 收藏 收藏
    DOI:10.1016/j.ultrasmedbio.2007.04.018 复制DOI
    作者列表:Sassaroli E,Hynynen K
    BACKGROUND & AIMS: :The investigation of inertial cavitation in micro-tunnels has significant implications for the development of therapeutic applications of ultrasound such as ultrasound-mediated drug and gene delivery. The threshold for inertial cavitation was investigated using a passive cavitation detector with a center frequency of 1 MHz. Micro-tunnels of various diameters (90 to 800 microm) embedded in gel were fabricated and injected with a solution of Optison(trade mark) contrast agent of concentrations 1.2% and 0.2% diluted in water. An ultrasound pulse of duration 500 ms and center frequency 1.736 MHz was used to insonate the microbubbles. The acoustic pressure was increased at 1-s intervals until broadband noise emission was detected. The pressure threshold at which broadband noise emission was observed was found to be dependent on the diameter of the micro-tunnels, with an average increase of 1.2 to 1.5 between the smallest and the largest tunnels, depending on the microbubble concentration. The evaluation of inertial cavitation in gel tunnels rather than tubes provides a novel opportunity to investigate microbubble collapse in a situation that simulates in vivo blood vessels better than tubes with solid walls do.
    背景与目标: :微隧道中惯性空化的研究对于超声治疗应用的发展具有重要意义,例如超声介导的药物和基因传递。使用中心频率为1 MHz的无源空化检测器研究了惯性空化的阈值。制造嵌入在凝胶中的各种直径的微隧道(90至800微米),并注入浓度为1.2%和0.2%的水中稀释的Optison(商标)造影剂溶液。持续时间为500毫秒,中心频率为1.736 MHz的超声脉冲用于使微泡产生声波。声压每隔1秒增加一次,直到检测到宽带噪声发射为止。发现观察到宽带噪声发射的压力阈值取决于微隧道的直径,最小隧道和最大隧道之间的平均增加幅度为1.2到1.5,具体取决于微气泡的浓度。凝胶隧道而不是管中的惯性空化的评估提供了一个新的机会,可以在模拟体内血管的情况下比具有坚固壁的管更好地研究微泡塌陷。
  • 【棘突棘:通过二维凝胶电泳分析蛋白质模式。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Wongkham C,Maleewong W,Ieamviteevanich K,Intapan PM,Morakote N
    BACKGROUND & AIMS: :The protein extracts from male (MS) and female (FS) adults and advanced third-stage larvae (LS) of Gnathostoma spinigerum were separated by high resolution two-dimensional gel electrophoresis (2-DE). The polypeptide spots, as detected by silver staining, were subsequently identified. The spot patterns of LS, MS and FS were highly complex and consisted of more than 75, 44, 52 prominent spots, respectively. In addition, the stage-specific protein patterns were identified. This 2-DE database should provide an important reference for future biological and biochemical studies of G. spinigerum.
    背景与目标: :通过高分辨率二维凝胶电泳(2-DE)分离了棘突棘鱼男性(MS)和女性(FS)成年人以及晚期第三阶段幼虫(LS)的蛋白质提取物。随后鉴定出通过银染检测的多肽斑点。 LS,MS和FS的斑点模式非常复杂,分别包含超过75、44、52个突出斑点。另外,鉴定了阶段特异性蛋白质模式。该2-DE数据库应为今后对菠菜的生物学和生化研究提供重要参考。
  • 【巢式PCR变性梯度凝胶电泳法测定茅台酒发酵发酵液大曲中的微生物多样性。】 复制标题 收藏 收藏
    DOI:10.1007/s11274-012-1045-y 复制DOI
    作者列表:Xiu L,Kunliang G,Hongxun Z
    BACKGROUND & AIMS: :This study endeavored to investigate the diversity of microbes present during the shaping, ripening and drying of Daqu, a fermentation starter culture and substrata complex of Maotai alcoholic spirit. A nested PCR-denaturing gradient gel electrophoresis technique was utilized with different combinations of primers. The results showed the presence of bacteria, yeasts and molds. The microflora, which originate from wheat, were readily detectable during every stage of the fermentation process. However, the microbial structure had clear differences in the shaping, ripening and drying processes. In the shaping stage, there was a high level of diversity of the LAB (lactic acid bacteria) and fungi in the shaped samples. In the ripening stage, however, a reduction of diversity of fungi with a high level of diversity of the Bacilli was observed in the ripened samples. In the drying stage, the diversity of Bacilli and fungi, especially acid-producing bacteria, reduced dramatically. Interestingly, uncultured Lactococcus sp., Microbacterium testaceum, Cochliobolus sp., and Thermoascus crustaceus were the first to be detected in the fermentation starters used in liquor production. This study revealed the microbial diversity and distributions during the shaping, ripening and drying of Daqu-making, facilitating evaluation of the hygienic conditions and aiding in the design of specific starter and/or adjunct cultures.
    背景与目标: :这项研究致力于调查在大曲酒的发酵,发酵发酵培养物和基质复合物大曲酒的成型,成熟和干燥过程中存在的微生物多样性。巢式PCR变性梯度凝胶电泳技术与引物的不同组合一起使用。结果表明存在细菌,酵母和霉菌。源自小麦的微生物区系在发酵过程的每个阶段都易于检测到。但是,微生物的结构在成型,成熟和干燥过程中存在明显差异。在成型阶段,成型样品中的LAB(乳酸菌)和真菌具有较高的多样性。然而,在成熟阶段,在成熟样品中观察到真菌的多样性降低,而芽孢杆菌的多样性高。在干燥阶段,芽孢杆菌和真菌的多样性,特别是产酸细菌的多样性大大降低。有趣的是,未经发酵的乳球菌属,睾丸微杆菌属,科氏单胞菌属和甲壳类嗜热菌首先在白酒生产中使用的发酵剂中被检测到。这项研究揭示了大曲制作过程中成型,成熟和干燥过程中的微生物多样性和分布,有助于评估卫生条件,并帮助设计特定的发酵剂和/或辅助培养物。
  • 【pH,水活度和凝胶微结构(包括氧分布和流变特性)对鼠伤寒沙门氏菌生长动力学的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.ijfoodmicro.2008.06.031 复制DOI
    作者列表:Theys TE,Geeraerd AH,Verhulst A,Poot K,Van Bree I,Devlieghere F,Moldenaers P,Wilson D,Brocklehurst T,Van Impe JF
    BACKGROUND & AIMS: :In this study, the growth of Salmonella Typhimurium in Tryptic Soy Broth was examined at different pH (4.50-5.50), water activity a(w) (0.970-0.992) and gelatin concentration (0%, 1% and 5% ) at 20 degrees C. Experiments in TSB with 0% gelatin were carried out in shaken erlenmeyers, in the weak 1% gelatin media in petri plates and in the firm 5% gelatin media in gel cassettes. A quantification of gel strength was performed by rheological measurements and the influence of oxygen supply on the growth of S. Typhimurium was investigated. pH, as well as a(w) as well as gelatin concentration had an influence on the growth rate. Both in broth and in gelatinized media, lowering pH or water activity caused a decrease of growth rate. In media with 1% gelatin a reduction of growth rate and maximal cell density was observed compared to broth at all conditions. However, the effects of decreasing pH and a(w) were less pronounced. A further increase in gelatin concentration to 5% gelatin caused a small or no additional drop of growth rate. The final oxygen concentration dropped from 5.5 ppm in stirred broth to anoxic values in petri plates, also when 0% and 5% gelatin media were tested in this recipient. Probably, not stirring the medium, which leads to anoxic conditions, has a more pronounced effect on the growth rate of S. Typhimurium then medium solidness. Finally, growth data were fitted with the primary model of Baranyi and Roberts [Baranyi, J. and Roberts, T. A., 1994. A dynamic approach to predicting bacterial growth in food. International Journal of Food Microbiology 23, 277-294]. An additional factor was introduced into the secondary model of Ross et al. [Ross, T. and Ratkowsky, D. A. and Mellefont, L. A. and McMeekin, T. A., 2003. Modelling the effects of temperature, water activity, pH and lactic acid concentration on the growth rate of Escherichia coli. International Journal of Food Microbiology 82, 33-43.] to incorporate the effect of gelatin concentration, next to the effect of pH and a(w). A two step and a global regression procedure were applied. Both procedures were able to fit the data well, but the global regression procedure led to smaller standard errors on the parameters.
    背景与目标: :在这项研究中,在不同pH(4.50-5.50),水分活度a(w)(0.970-0.992)和明胶浓度(0%,1%和5%)下检测了鼠伤寒沙门氏菌在大豆胰液中的生长。 20℃。在摇动的锥形瓶中,在培养皿中的弱1%明胶培养基和在凝胶盒中的牢固的5%明胶培养基中,在含0%明胶的TSB中进行实验。通过流变学测量对凝胶强度进行定量,并研究了氧气供应对鼠伤寒沙门氏菌生长的影响。 pH值以及a(w)以及明胶浓度对生长速率都有影响。在肉汤和糊化培养基中,降低pH值或水活度都会导致生长速率下降。在所有条件下,与肉汤相比,在含1%明胶的培养基中,观察到生长速率和最大细胞密度降低。但是,降低pH和a(w)的影响不太明显。明胶浓度进一步增加到5%明胶会导致生长速率的下降很小或没有下降。当在该接受者中测试0%和5%明胶培养基时,最终氧气浓度也从搅拌肉汤中的5.5 ppm降至皮氏培养皿中的缺氧值。可能,不搅拌导致缺氧条件的培养基,对伤寒沙门氏菌的生长速率的影响要比培养基的坚固性更为明显。最后,生长数据符合Baranyi和Roberts的主要模型[Baranyi,J.和Roberts,T. A.,1994。一种预测食物中细菌生长的动态方法。国际食品微生物学杂志23,277-294]。 Ross等人的次级模型中引入了一个额外的因素。 [Ross,T.和Ratkowsky,D. A.和Mellefont,L. A.和McMeekin,T. A.,2003年。模拟温度,水活度,pH和乳酸浓度对大肠杆菌生长速率的影响。 International Journal of Food Microbiology 82,33-43。]将明胶浓度的影响与pH和a(w)的影响相结合。应用了两步和全局回归程序。两种方法都能很好地拟合数据,但是全局回归方法导致参数上的标准误差较小。
  • 【脐带血血小板凝胶对人间质基质细胞伤口愈合能力的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.transci.2020.102734 复制DOI
    作者列表:Mallis P,Alevrogianni V,Sarri P,Velentzas AD,Stavropoulos-Giokas C,Michalopoulos E
    BACKGROUND & AIMS: BACKGROUND:Wound healing is a dynamic process, involving the recruitment of growth factors, cytokines, chemokines and cellular populations. Recently, the Cord Blood Platelet Gel (CBPG) has been applied successfully in wound closure and tissue regeneration. Moreover, its proper combination with stem cell populations such as Mesenchymal Stromal Cells (MSCs) may positively improve the wound healing process. Based on the above data, this study aimed to the evaluation of wound healing capacity of MSCs combined with CBPG under in vitro conditions. METHODS:Initially, CBPG was developed from Cord Blood Units (CBUs). The determination of wound healing ability of MSCs was performed using the scratch wound assay. In addition, the morphological features, immunophenotypical characteristics and differentiation capacity of MSCs were evaluated. RESULTS:Scratch wound assay results showed, that CBPG could positively stimulate the MSCs migration. Moreover, MSCs cultured in presence of CBPG were characterized by elongated shape and improved stemness properties as it was indicated by flow cytometric analysis and differentiation process. CONCLUSION:These results clearly showed the beneficial effect of CBPG in combination with MSCs in wound healing. The proper combination of CBPG with stem cells strategy may enhance the healing process in patients with skin erosions.
    背景与目标: 背景:伤口愈合是一个动态过程,涉及生长因子,细胞因子,趋化因子和细胞群的募集。最近,脐带血血小板凝胶(CBPG)已成功应用于伤口闭合和组织再生。此外,将其与干细胞群体(如间质基质细胞(MSC))适当组合可积极改善伤口愈合过程。基于上述数据,本研究旨在评估在体外条件下结合CBPG的MSCs的伤口愈合能力。
    方法:最初,CBPG是从脐带血单位(CBU)开发的。 MSCs的伤口愈合能力的测定是使用刮擦伤口测定法进行的。此外,评价了MSC的形态特征,免疫表型特征和分化能力。
    结果:刮伤试验结果表明,CBPG可以积极刺激MSC的迁移。而且,通过流式细胞术分析和分化过程表明,在CBPG存在下培养的MSC具有细长的形状和改善的干特性。
    结论:这些结果清楚地表明,CBPG与MSC联合在伤口愈合中具有有益作用。 CBPG与干细胞策略的适当组合可增强皮肤糜烂患者的愈合过程。
  • 【血吸虫病感染期间从聚-N-乙酰氨基葡萄糖凝胶基质释放的IL-12的免疫调节作用。】 复制标题 收藏 收藏
    DOI:10.1007/s10616-013-9620-0 复制DOI
    作者列表:Salem ML,Shoukry NM,Zidan AA,Vournakis J
    BACKGROUND & AIMS: :We have reported recently that Interleukin-12 (IL-12) released from poly-N-acetyl glucosamine gel matrix (F2 gel/IL-12) is more effective than free IL-12 to enhance vaccination of mice with Schistosoma soluble worm antigen preparation. The aim of this study is to evaluate the effect of F2 gel/IL-12 on the inflammatory responses in mice undergoing schistosomiasis infection in absence of vaccination. To achieve this, mice undergoing Schistosoma mansoni infection or cured from this infection, after treatment with praziquantil (PZQ), were treated with subcutaneous injection of IL-12 for 3 consecutive days or once with F2 gel loaded with IL-12 (F2 gel/IL-12). The treatment was started on day 35 days after infection. For infection, mice were infected with 100 cercariae of S. mansoni using tail immersion method. We found that treatment with F2 gel/IL-12 induced significant decreases in the egg burden with a moderate reduction in the size of granuloma and decrease in the cellular granulomatous reaction in the lung as compared to infected mice treated with IL-12. These effects of F2 gel/IL-12 were more pronounced in infected mice previously treated with the anti-schistosomal drug PZQ. The total numbers of white blood cells in all treated mice showed similar profile. Treatment with IL-12 or F2 gel/IL-12, however, showed significant reduction in the number of mononuclear cells when compared with non-treated infected mice. In conclusion, this study showed the ability of IL-12 released from F2 gel to lower the inflammatory response to Schistosoma infection even in absence of vaccination.
    背景与目标: :我们最近报道说,从聚-N-乙酰氨基葡萄糖凝胶基质(F2凝胶/ IL-12)中释放的白介素12(IL-12)比游离IL-12更加有效地增强了血吸虫可溶性蠕虫抗原小鼠的疫苗接种准备。这项研究的目的是评估F2凝胶/ IL-12对在没有接种疫苗的情况下遭受血吸虫病感染的小鼠的炎症反应的影响。为此,在接受吡喹酮(PZQ)治疗后,将经历曼氏血吸虫感染或从这种感染中治愈的小鼠连续3天皮下注射IL-12或用载有IL-12的F2凝胶(F2 gel / IL-12)。在感染后第35天开始治疗。为了进行感染,使用尾部浸没法用100株曼氏链球菌尾感染小鼠。我们发现,与用IL-12治疗的受感染小鼠相比,用F2凝胶/ IL-12治疗可显着降低鸡蛋负担,同时肉芽肿大小可适度减少,肺中细胞肉芽肿反应减少。 F2 gel / IL-12的这些作用在先前用抗血吸虫病药物PZQ治疗的受感染小鼠中更为明显。在所有处理过的小鼠中白细胞的总数显示出相似的特征。然而,与未治疗的感染小鼠相比,用IL-12或F2凝胶/ IL-12治疗显示单核细胞数量显着减少。总之,这项研究表明,即使没有疫苗接种,从F2凝胶中释放的IL-12的能力也能降低对血吸虫感染的炎症反应。
  • 【离子液体对高直链淀粉淀粉的溶胶-凝胶相变,动力学和流变性质的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.ijbiomac.2020.06.186 复制DOI
    作者列表:Devi LS,Das AB
    BACKGROUND & AIMS: :The effect of 1-butyl-3-methylimidazolium chloride (BMIMCl) as a plasticizer on sol-gel phase transition, rheological, and physical properties of high amylose rice starch was studied. The inter-relationships of parameters were determined using principal component analysis. The sol-gel phase transition temperature and storage modulus of starch was varied significantly (p ≤ 0.05) in the presence of BMIMCl. The sol-gel phase transition temperature of native starch was varied between 53.99 and 39.7 °C, whereas, for starch with ionic liquid varied between 49.50 and 40.6 °C. The changes in storage modulus (G') during the sol-gel phase transition were suitable with first order kinetics. The temperature dependent rheology of starch during the sol-gel phase transition was efficiently (0.93 ≤ R2 ≤ 0.98) explained using the Arrhenius model. The thermal stability of the gel was improved in the presence of BMIMCl. The textural and electrical properties of the gel were significantly affected by the presence of BMIMCl. The inter-relationships between the parameters were developed and the initial temperature, resistance, and storage modulus showed a strong interrelation.
    背景与目标: :研究了1-丁基-3-甲基咪唑鎓氯化物(BMIMCl)作为增塑剂对高直链淀粉米淀粉的溶胶-凝胶相变,流变和物理性质的影响。使用主成分分析确定参数之间的相互关系。在BMIMCl存在下,淀粉的溶胶-凝胶相变温度和淀粉的储能模量有显着变化(p≤0.05)。天然淀粉的溶胶-凝胶相变温度在53.99至39.7°C之间变化,而离子液体淀粉在49.50至40.6°C之间变化。溶胶-凝胶相变过程中储能模量(G')的变化适合一级动力学。使用Arrhenius模型可以有效地解释淀粉在溶胶-凝胶相变过程中的温度依赖性流变(0.93≤R2≤0.98)。在BMIMCl的存在下改善了凝胶的热稳定性。 BMIMCl的存在显着影响了凝胶的质地和电性能。建立了参数之间的相互关系,并且初始温度,电阻和储能模量显示出很强的相互关系。
  • 【评价变性梯度凝胶电泳以区分二级环境中的大肠杆菌种群。】 复制标题 收藏 收藏
    DOI:10.1111/j.1462-2920.2006.01105.x 复制DOI
    作者列表:Sigler V,Pasutti L
    BACKGROUND & AIMS: :The development of methodology to differentiate mixed populations of Escherichia coli in the secondary habitat might improve monitoring of fecal pollution indicators and facilitate the development of strategies to mitigate bacterial pollution. The objective of this study was to determine the ability of denaturing gradient gel electrophoresis (DGGE) to differentiate mixed assemblages of E. coli in the natural environment. After confirming the identity of 184 environmental bacterial isolates as E. coli, each was subjected to polymerase chain reaction (PCR) of the beta-glucuronidase gene (uidA) followed by DGGE fingerprinting. The ability of DGGE to discriminate individual isolates at the strain level was determined by comparing fingerprints to those resulting from a standard, library-dependent fingerprinting method, BOX-PCR. Computerized analysis of fingerprints indicated that DGGE and BOX-PCR identified 15 and 21 unique phylotypes respectively. Rank-abundance plots comparing the numerical distribution of unique E. coli phylotypes detected by both methods revealed no difference in resolution at the population level. In water and sediment samples from two beaches, DGGE effectively distinguished indigenous E. coli populations with an average rate of correct classification (site-based) of 83%. Denaturing gradient gel electrophoresis of uidA genes isolated and PCR-amplified from environmental samples appears to be an effective tool to differentiate unique E. coli populations and should be useful to characterize E. coli dynamics in the secondary environment.
    背景与目标: :发展区分次级生境中大肠杆菌混合种群的方法学,可能会改善对粪便污染指标的监测,并有助于制定减轻细菌污染的策略。这项研究的目的是确定变性梯度凝胶电泳(DGGE)在自然环境中区分大肠杆菌混合组合的能力。在确认了184种环境细菌分离株的身份为大肠埃希菌后,对每种细菌进​​行β-葡萄糖醛酸苷酶基因(uidA)的聚合酶链反应(PCR),然后进行DGGE指纹分析。通过比较指纹与标准,依赖库的指纹分析方法BOX-PCR产生的指纹,可以确定DGGE在菌株水平上区分各个分离株的能力。指纹的计算机分析表明,DGGE和BOX-PCR分别鉴定了15种和21种独特的系统型。比较两种方法检测到的独特大肠杆菌系统型的数值分布的秩-丰度图显示,在种群水平上分辨率没有差异。在来自两个海滩的水和沉积物样本中,DGGE有效地区分了本土大肠杆菌种群,正确分类(基于现场)的平均比率为83%。从环境样品中分离并通过PCR扩增的uidA基因的变性梯度凝胶电泳似乎是区分独特的大肠杆菌种群的有效工具,并且对于表征次级环境中的大肠杆菌动态也应是有用的。
  • 【TGF-β1和rhBMP-2对胶原凝胶基质中培养的人骨髓基质细胞的相互作用。】 复制标题 收藏 收藏
    DOI:10.3349/ymj.2001.42.3.338 复制DOI
    作者列表:Kim MK,Niyibizi C
    BACKGROUND & AIMS: :Transforming growth factor-beta1 (TGF-beta1) and bone morphogenetic protein-2 (BMP-2) are abundant proteins in the bone matrix. However, their interaction in controlling osteoblast differentiation is not clearly understood. In this study, HBMSCs were cultured in collagen gel matrix with different condition of exogenous rhBMP-2 and TGF-beta1 in order to determine the interaction of BMP-2 and TGF-beta1 on human bone marrow stromal cells (HBMSCs) differentiation. The cultured cells were analyzed for cell proliferation, alkaline phophatase (ALP) activity and mineralization staining with Von-Kossa. The cells treated with TGF-beta1 exhibited a higher rate of cell growth than those without. However, the cells cultured in collagen gel matrix showed a lower rate of cell growth than the cells cultured in a monolayer. To investigate the effects of both cytokines on osteoblast differentiation, the cells were treated with 0, 1, 5, 10 ng/ml of TGF-beta1 for 2 days. This was followed by culturing with 0, 1, 5, and 10 ng/ml of TGF-beta1 and 100 ng/ml of rhBMP-2 together for 3 days with the alkaline phosphatase (ALP) activity measured. The cells treated with 1 ng/ml of TGF-beta1 responded efficiently to rhBMP-2 and expressed ALP activity with a level equivalent to that exhibited by cells that were not treated with TGF-beta1. The cells treated with 5 and 10 ng/ml of TGF-beta1 showed a dramatic decrease in ALP activity. The cells treated with 10 ng/ml of TGF-beta1 followed by rhBMP-2 alone exhibited an intermediate ALP activity. The cells treated with 100 ng/ml of rhBMP-2 demonstrated Von-Kossa positive solid deposits after 3 weeks, while there were few Von-Kossa positive solid deposits when the cells treated with 10 ng/ml of TGF-beta1. These results show that TGF-beta1 inhibits the effects of rhBMP-2 on the osteoblast differentiation of HBMSCs in a dose dependant manner. Furthermore, the effects of TGF-beta1 on HBMSCs are reversible. This suggest that TGF-beta1 and rhBMP-2 are coordinately controlled during the osteoblast differentiation of HMBSCs.
    背景与目标: :转化生长因子β1(TGF-beta1)和骨形态发生蛋白2(BMP-2)是骨基质中的丰富蛋白。但是,尚不清楚它们在控制成骨细胞分化中的相互作用。在这项研究中,HBMSCs在具有不同条件的外源性rhBMP-2和TGF-beta1的胶原蛋白凝胶基质中培养,以确定BMP-2和TGF-beta1对人骨髓基质细胞(HBMSCs)分化的相互作用。用Von-Kossa分析培养的细胞的细胞增殖,碱性磷酸酶(ALP)活性和矿化染色。用TGF-β1处理的细胞比未用TGF-β1处理的细胞表现出更高的细胞生长速率。但是,与在单层中培养的细胞相比,在胶原凝胶基质中培养的细胞显示出较低的细胞生长速率。为了研究两种细胞因子对成骨细胞分化的影响,将细胞分别以0、1、5、10 ng / ml的TGF-beta1处理2天。随后,分别与0、1、5和10 ng / ml的TGF-beta1和100 ng / ml的rhBMP-2一起培养3天,并测量碱性磷酸酶(ALP)的活性。用1 ng / mlTGF-β1处理的细胞对rhBMP-2有效反应,并以与未用TGF-β1处理的细胞相同的水平表达ALP活性。用5和10 ng / ml的TGF-beta1处理的细胞显示ALP活性急剧下降。用10 ng / ml的TGF-beta1和单独的rhBMP-2处理的细胞表现出中等的ALP活性。用100 ng / ml rhBMP-2处理的细胞在3周后表现出Von-Kossa阳性固体沉积,而当用10 ng / ml的TGF-beta1处理时,Von-Kossa阳性固体沉积很少。这些结果表明,TGF-β1以剂量依赖的方式抑制了rhBMP-2对HBMSCs成骨细胞分化的影响。此外,TGF-β1对HBMSC的作用是可逆的。这表明在HMBSCs的成骨细胞分化过程中,TGF-beta1和rhBMP-2受到协调控制。
  • 【通过脂质体的掺入提高了细菌绿素a的光敏效率。】 复制标题 收藏 收藏
    DOI:10.1016/s1011-1344(01)00118-x 复制DOI
    作者列表:Damoiseau X,Schuitmaker HJ,Lagerberg JW,Hoebeke M
    BACKGROUND & AIMS: :To describe the action mechanisms of Bacteriochlorin a (BCA), a second generation photosensitizer, in phosphate buffer (PB) and in dimyristoyl phosphatidylcholine (DMPC) liposomes we carried out oxygen consumption and ESR measurements. In PB, where BCA was in a monomer-dimer equilibrium, our results suggested that the oxygen consumption was related to the BCA monomers concentration in solution. Incorporation of BCA in DMPC liposomes, by promoting the monomerization of BCA, increased 9-fold the oxygen consumption in comparison to the value in PB. The use of specific singlet oxygen quenchers (Azide and 9,10-Anthracenedipropionic acid) in ESR and oxygen consumption experiments allowed us to assert that BCA was mainly a type II sensitizer when it was incorporated in DMPC. Finally, the cell survival of WiDr cells after a PDT treatment was measured for cells incubated with BCA in cell culture medium and cells incubated with BCA in DMPC. Irrespective of the dye concentration, the cell survival was lower when liposomes were used. This effect could be the result of a better BCA monomerization and/or a different BCA uptake in cells.
    背景与目标: :为了描述第二代光敏剂细菌绿霉素a(BCA)在磷酸盐缓冲液(PB)和二肉豆蔻酰磷脂酰胆碱(DMPC)脂质体中的作用机理,我们进行了耗氧量和ESR测量。在PB中,BCA处于单体-二聚体平衡状态时,我们的结果表明,耗氧量与溶液中BCA单体的浓度有关。与PB中的值相比,通过促进BCA的单体化,将BCA掺入DMPC脂质体中可使耗氧量增加9倍。在ESR和耗氧实验中使用特定的单线态氧猝灭剂(叠氮化物和9,10-蒽二丙酸)使我们断言,将BCA掺入DMPC时,它主要是II型敏化剂。最后,对PDT处理后WiDr细胞的细胞存活率进行了测量,其中在细胞培养基中与BCA一起孵育的细胞以及在DMPC中与BCA一起孵育的细胞。不管染料浓度如何,当使用脂质体时,细胞存活率都较低。这种效果可能是由于BCA单体聚合效果更好和/或细胞中BCA摄入量不同所致。

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