中药新药保肝作用的研究进展

肝脏作为代谢器官,在人体内发挥着重要作用。随着肝病的发病率逐年上升,如何有效的保肝护肝已成为医学界和药学界共同面一临的巨大挑战之一。化学药物在治疗肝病的同时常常伴随各种毒副作用甚至更进一步的肝损伤,而中药凭借其安全性和有效性的优势在肝病治疗领域受到越来越多的重视。中药护肝已有悠久的历史,近年来随着技术的进步,更多更好的新型中药逐步上市,相关研究不断增多。本文将就这些研究成果进行阐述。     

Measurement on Camber Deformation of Wings of Free-flying Dragonflies and Beating-flying Dragonflies

1　IntroductionNumerouskinematicparameters,includingwing beatfrequency ,wingorientation ,andbothspan andchord wisedeformation ,arerelevanttotheaerodynam icanalysisofinsectflight[1,2 ] .Althoughnearlyalltherecentstudiesofinsectflightaerodynamics[3,4 ] haveidentifiedthatthemechanismsrequireflowseparationattheleadingedge ,andcamberisnotexpectedtohaveanysignificantinfluenceonthemagnitudeoftheforcecoefficient,someinsects ,suchasdragonfliesandbut terflies,frequently glideusinglowanglesofattack ,lead…     

表没食子儿茶素没食子酸酯对人结肠癌HT-29细胞G1期的阻滞作用

目的:研究表没食子儿茶素没食子酸酯(Epigallaocatechin-3-gallate,EGCG)时人结肠癌HT-29细胞增殖的影响.方法:实验分为EGCG不同浓度处理组和阴性对照组.采用MTT比色法检测EGCG(30μg/mL、40μg/mL、50μg/mL、60μg/mL、70μg/mL)对HT-29细胞的生长影响;应用流式细胞术分析EGCG对HT-29细胞周期分布的影响;免疫印迹观测EGCG对HT-29细胞p38MAPK、cyclinD1蛋白表达的影响.结果:MTT比色结果显示.不同浓度EGCG(30μg/ml、40μg/ml、50μg/ml、60μg/ml)对HT-29细胞具有明显的生长抑制作用,并呈剂量-效应依赖关系(P<0.05);流式细胞术分析显示,EGCG诱导人结肠癌细胞G1期阻滞,且随着处理时间的延长,其诱导周期阻滞的效应越明显(P<0.05);蛋白免疫印迹显示.总的p38MAPK不随处理时间和浓度的改变而改变,但是磷酸化的p38MAPK蛋白的表达随处理时间和处理浓度的增加而明显增加,而CyclinD1蛋白的表达随处理浓度的增加而明显减少.结论:EGCG诱导HT-29细胞G1期阻滞,抑制细胞增殖,可能与活化p38MAPK,下调CyclinD1蛋白表达有关.     

Understanding the Impact of 2D and 3D Fibroblast Cultures on In Vitro Breast Cancer Models

The utilization of 3D, physiologically relevant in vitro cancer models to investigate complex interactions between tumor and stroma has been increasing. Prior work has generally focused on the cancer cells and, the role of fibroblast culture conditions on tumor-stromal cell interactions is still largely unknown. Here, we focus on the stroma by comparing functional behaviors of human mammary fibroblasts (HMFs) cultured in 2D and 3D and their effects on the invasive progression of breast cancer cells (MCF10DCIS.com). We identified increased levels of several paracrine factors from HMFs cultured in 3D conditions that drive the invasive transition. Using a microscale co-culture model with improved compartmentalization and sensitivity, we demonstrated that HMFs cultured in 3D intensify the promotion of the invasive progression through the HGF/c-Met interaction. This study highlights the importance of the 3D stromal microenvironment in the development of multiple cell type in vitro cancer models.     

昆虫抗药性和昆虫毒理动力学(英文)

不断地使用一种杀虫药剂防治昆虫,会导致昆虫产生抗药性。对昆虫抗药性资料进行广泛综述时,发现了仅单独的解毒作用不能被解释为家蝇对有机氯杀虫药剂产生高抗性原因。作为一个基因。家蝇可以对有机氯产生比对有机磷杀虫剂更高的抗药性,尽管有机磷杀虫剂一般在虫体内是不太稳定的。考虑到昆虫毒理的动力学,杀虫药剂的穿透作用更显示出其实际的重要性。根据穿透和解毒的速率,慢的穿透作用是解毒作用的一个限制因子。防治敏感和抗性昆虫的观察结果,可以划出物理和生物因子之间关系的几种相关曲线图解。这些相关性不仅能说明家蝇对有机磷和有机氯杀虫剂的抗性程度,而且也助于选择出新的杀虫毒剂。     

3D Collagen Alignment Limits Protrusions to Enhance Breast Cancer Cell Persistence

Patients with mammographically dense breast tissue have a greatly increased risk of developing breast cancer. Dense breast tissue contains more stromal collagen, which contributes to increased matrix stiffness and alters normal cellular responses. Stromal collagen within and surrounding mammary tumors is frequently aligned and reoriented perpendicular to the tumor boundary. We have shown that aligned collagen predicts poor outcome in breast cancer patients, and postulate this is because it facilitates invasion by providing tracks on which cells migrate out of the tumor. However, the mechanisms by which alignment may promote migration are not understood. Here, we investigated the contribution of matrix stiffness and alignment to cell migration speed and persistence. Mechanical measurements of the stiffness of collagen matrices with varying density and alignment were compared with the results of a 3D microchannel alignment assay to quantify cell migration. We further interpreted the experimental results using a computational model of cell migration. We find that collagen alignment confers an increase in stiffness, but does not increase the speed of migrating cells. Instead, alignment enhances the efficiency of migration by increasing directional persistence and restricting protrusions along aligned fibers, resulting in a greater distance traveled. These results suggest that matrix topography, rather than stiffness, is the dominant feature by which an aligned matrix can enhance invasion through 3D collagen matrices.     

A New Tool to Quantify Receptor Recruitment to Cell Contact Sites during Host-Pathogen Interaction

To understand the process of innate immune fungal recognition, we developed computational tools for the rigorous quantification and comparison of receptor recruitment and distribution at cell-cell contact sites. We used these tools to quantify pattern recognition receptor spatiotemporal distributions in contacts between primary human dendritic cells and the fungal pathogens C. albicans, C. parapsilosis and the environmental yeast S. cerevisiae, imaged using 3D multichannel laser scanning confocal microscopy. The detailed quantitative analysis of contact sites shows that, despite considerable biochemical similarity in the composition and structure of these species'' cell walls, the receptor spatiotemporal distribution in host-microbe contact sites varies significantly between these yeasts. Our findings suggest a model where innate immune cells discriminate fungal microorganisms based on differential mobilization and coordination of receptor networks. Our analysis methods are also broadly applicable to a range of cell-cell interactions central to many biological problems.