TNF-α与胆管癌侵袭转移的研究进展

胆管癌是一种恶性胆管上皮肿瘤,其早期诊断困难,导致胆管癌患者预后差。TNF-α作为一种主要的炎性因子,在很多肿瘤的发生发展中起重要作用。在慢性胆管炎症中能诱导胆管癌的发生发展,并在促进胆管癌侵袭转移中扮演一种总开关角色,本综述分析它与胆管癌的侵袭与转移之间的密切关系,并提示抑制TNF-α对胆管癌治疗及预防具有重要作用。     

上皮间质转化与肝癌微环境变化的关系

通过对上皮间质转化理论基础的回顾,探讨上皮间质转化、间质上皮转化与肝脏纤维化及肝癌干细胞转化的关系,从而寻找肝癌干细胞的相关基因、抗体标记物及关键通路,这不仅有利于肝细胞癌分期的诊断,提示预后,更为寻找医治肝癌的方法提供更多的研究方向。     

Evaluation of the High- and Low-Temperature Performance of Asphalt Mortar Based on the DMA Method

Asphalt mortar is a typical temperature-sensitive material that plays a crucial role in the performance of asphalt mixture. This study evaluates the high- and low-temperature performance of asphalt mortar based on the dynamic mechanical analysis (DMA) method. Temperature-sweep tests of asphalt mortars were conducted using the DMA method under fixed strain level, frequency, and heating rate conditions. The dynamic mechanical response curves, characteristic temperature, and other indices were obtained and used to investigate the high- and low-temperature performance of asphalt mortar. The results showed that the phase transition temperatures T₁, T₀, and T_g can be used to evaluate the low-temperature performance of asphalt mortar. Additionally, they had a good linear relationship, and the evaluation results were consistent. Meanwhile, T₂, E₆₀, and tan(δ)_max indicators can effectively evaluate the high-temperature performance of asphalt mortar. Asphalt plays a key role in the performance of asphalt mortar. Mortars with neat asphalt A70 and modified asphalt AR had the worst and best high- and low-temperature performances, respectively. Furthermore, the finer gradation improved the low-temperature performance of asphalt mortar, while the coarser gradation improved the high-temperature properties of modified asphalt mortars but had the opposite effect on neat asphalt A70.     

Degradation Mechanism and Numerical Simulation of Pervious Concrete under Salt Freezing-Thawing Cycle

In order to explore the occurrence area of pervious concrete freeze-thaw deterioration, the mass loss, strength deterioration, ultrasonic longitudinal wave velocity and dynamic elastic modulus attenuation of pervious concrete under freeze-thaw cycles were measured, and a prediction model of freeze-thaw damage was established. The mechanical properties of hardened cement pastes with the same W/C ratio under freeze-thaw cycles were also measured. Mercury intrusion porosimetry (MIP) was used to measure the pore structure characteristic parameters and pore size distribution changes of cement paste under freeze-thaw cycle, and the microstructure evolution of interfacial transition zone (ITZ) of paste and aggregate was observed by SEM scanning electron microscopy. Finally, a pervious concrete model was established by DEM to analyze the relationship between the number of freeze-thaw cycles and the mesoscopic parameters. The results indicated that the quality, strength and dynamic elastic modulus of pervious concrete deteriorate to different degrees under the conditions of water freezing and salt freezing. The damage sensitivity and strength loss of freeze-thaw damage is greater than the dynamic elastic modulus loss, which is greater than mass loss. In the pervious concrete paste which underwent 100 freeze-thaw cycles, the pore structure and macro strength had no obvious change, and hardened paste and the aggregate-interface-generated defects increased with the increase in freezing and thawing times, indicating that the deterioration of pervious concrete performance under freeze-thaw cycles was closely related to the deterioration of the interface strength of the aggregate and hardened paste. The pervious concrete model established by DEM can accurately simulate the change of the compressive modulus and the strength of pervious concrete during freeze-thaw cycles.     

血清线粒体型门冬氨酸转移酶在百草枯中毒大鼠的价值

目的通过检测SD大鼠血清线粒体型天门冬氨酸氨基转移酶(mAST)的浓度的变化及其余各项血气和生化指标的相关性,探讨百草枯(PQ)中毒损伤的机制及mAST在百草枯中毒早期评估多器官功能中的价值。方法将84只健康SD大鼠随机分为对照组和染毒组,灌胃后0 h、2 h、6 h、12 h、24 h、48 h及72 h分别收集动脉血做血气分析,检测大鼠mAST及其他生化指标的浓度变化。结果 mAST在PQ中毒2 h即明显升高,远远早于动脉血气及动脉血乳酸值,而与反映急性肝功能损伤的指标(AST、ALT、DBIL、TBIL)、反映肝纤维化指标(γGT)、反映肾功能损伤的指标(SRBP)及一些特异性不强的指标(CK,LDH)呈显著正相关。结论 mAST在大鼠中毒早期组织未出现缺氧时即有显著升高且与反映肝肾功能的多个生化指标正相关,提示线粒体损伤可能是百草枯中毒致多器官损伤的发病机制中独立于组织缺氧的一项重要因素,对早期评估百草枯中毒患者肝肾功能损伤程度有参考价值。     

Effect of Rapamycin on TGF-β1- induced epithelial-mesenchymal transition in LoVo colonic adenocarcinoma cells

Objective:To investigate the effect of Rapamycin on epithelial-mesenchyrnal transition(EMT) of LoVo colonic adenocarcinoma cells in vitro.Methods:Cultured LoVo colonic adenocarcinoma cells were divided into three groups: negative control group,EMT-inducing group(TGF-β1) and EMT-interfering group(TGF-β1 plus Rapamycin).E-cadherin expression in LoVo cells was detected by Western Blot,while the expression of vimentin was evaluated through immunocytochemistry.The Snail mRNA in LoVo cells was examined by RT-PCR.Results:TGF-β1 induced LoVo cell switching from polygonal to spindle-shaped.TGF-β1 enhanced the expression of vimentin,but lowered the level of E-cadherin.In contrast,Rapamycin impaired the transition induced by TGF-β1.Rapamycin dramatically abrogated TGF-β1-induced vimentin expression and restored E-cadherin expression in LoVo cells.Rapamycin significantly repressed the up-regulation of Snail mRNA expression induced by TGF-β1.Conclusion:Rapamycin dramatically abrogated TGF-β1 induced Snail mRNA expression in LoVo cells,hence inhibiting EMT of these cells in vitro.     

Epithelial to mesenchymal transition in the progression of tubulointerstitial fibrosis

Objective To review the mechanisms of epithelial to mesenchymal transition (EMT) and its role in the progression of tubulointerstitial fibrosis.Data sources The data used in this review were obtained mainly from the studies of EMT reported from 2000–2006.Study selection Relevant articles on studies of EMT in tubulointerstitial fibrosis were selected. Data were mainly extracted from the 45 articles listed in the reference section of this review.Results The process of EMT has gained wide recognition as candidate mechanism in progression of chronic fibrotic disorders. New markers were identified and facilitate the observation of EMT. EMT is regulated by many factors through activation of kinase-dependent signaling cascades. Recent findings suggest that EMT is a reversible process, which can be controlled by factors for their epithelial inducing activities. Conclusion Remarkable progresses of EMT research have been made recently. Preventing or reversing EMT is a promising strategy against renal fibrosis.     

孔扩散阻力对多孔催化剂失活动力学的影响

目前,在强扩散区城中,失活催化反应的分离型动力学方程式仅能用于1级反应和1级独立失活系统。本文把此类方程式扩展应用于各种1,2级反应和1,2级独立失活系统,同时针对气-固相反应器中气相流动呈活塞流或全混流的情况,讨论了如何由实验求取有关的动力学速率常数值。研究结果表明,过程存在孔扩散阻力时,反应转化率随着反应时间降低的速率比无孔扩散阻力的情况要慢。此外,对浓度独立失活和分离型动力学方程的特征也作了论述。     

lncRNA DNM3OS在喉鳞状细胞癌组织和细胞中的表达及其临床和生物学意义

目的:检测lncRNA DNM3OS在喉鳞状细胞癌(laryngeal squamous cell carcinoma,LSCC)组织和LSCC细胞株中的表达及其临床意义,探讨其对LSCC TU177细胞体外增殖、迁移及侵袭的影响,并分析DNM3OS与EMT的关系.方法:从河北医科大学第四医院生物标本库选取2014年3...     

核孔蛋白与肿瘤

在真核生物中,细胞的物质交换在其增殖和凋亡中长期存在,而细胞核与质的交换只能通过核孔复合体(NPC)进行的穿梭运动实现.NPC位于细胞核膜,通过穿梭运动实现真核生物中核与质之间蛋白、RNA等物质的运输任务.特定的核孔蛋白会调节特定的运输路径,而正是由于此,通过NPC进行的运输和调节是高选择性和协调性,从而使NPC在基因表达、信号网络和保持细胞内环境中起到了重要作用.它们当中有的会改变核膜的结构性状,影响有丝分裂,有的可以通过与激酶结合导致异常的生化反应,或者与其他生物因子作用,在血管生成、细胞迁移或者细胞生成及凋亡的环节出现异常变化,从而导致肿瘤的发生.