浅论临床医学教育的困境与对策

高校扩招、专业增多，教师教学任务加重、教师梯队建设相对滞后，卫生制度的改革，学生双向择业时间的延长等诸多因素给临床医学教育带来前所未有的冲击，通过分析重庆医科大学临床教学出现的困境，提出了应对措施，旨在确保人才培养质量的提高。     

红景天甙对大鼠肝组织TGF-β1/Smads信号通路的作用

目的:结扎肝动脉(Hepatic artery ligation,HAL)建立急性大鼠肝损伤模型,探讨药物红景天甙对大鼠肝损伤时TGF-β1、Smad2/3、P-Smad2/3、及c-ski表达的影响.方法:66只Wistar大鼠随机分为对照组、肝动脉结扎组和红景天甙干预组,结扎分为1、2、4、6、8h5个时间段,红景...     

丹参素对PDGF-BB刺激下肝星状细胞的抑制作用

目的观察丹参素对PDGF-BB刺激下大鼠肝星状细胞活化增殖,Ⅰ、Ⅲ型胶原合成与分泌,ERK1/2和PI3K通道蛋白表达的影响,探讨丹参素抑制肝纤维化的分子机制。方法用不同浓度丹参素(0.250、0.125、0.062 mmol/L)、ERK通道特异性抑制剂UO126(20 nmol/L)和PI3K通道特异性抑制剂LY294002(20 nmol/L)分别作用于经血小板衍生生长因子PDGF-BB(10 ng/ml)处理的大鼠肝星状细胞(HSC)48 h,CCK8法检测HSC增殖活性,免疫化学染色法测定Ⅰ、Ⅲ型胶原合成,酶联免疫吸附法观察Ⅰ、Ⅲ型胶原分泌,Western blot测定ERK1/2、p-ERK1/2、AKT和p-AKT蛋白表达。结果 PDGF-BB 10 ng/ml处理后,HSC增殖明显增加(0.139±0.009),丹参素能抑制PDGF-BB刺激大鼠HSC增殖的作用,并随丹参素浓度增加(0.062、0.125、0.250 mmol/L)细胞增殖受到的抑制作用越强(0.102±0.008、0.083±0.007、0.066±0.014,P<0.05),Ⅰ、Ⅲ型胶原合成及分泌均显著减少(P<0.05),p-ERK1/2和p-AKT蛋白表达均显著降低(P<0.05)。结论丹参素可通过抑制PDGF-BB诱导的HSC增殖和活化,同时抑制与肝纤维化密切相关的MAPK、PI3K途径中ERK、AKT蛋白的磷酸化,负性调控肝纤维化过程,其机制可能与抑制ERK1/2和PI3K信号转导通路有关。     

丹参素对转化生长因子β1刺激肝星状细胞信号传导的影响

目的:探讨丹参素对转化生长因子β1(Transformation growth factor,TGFβ1)刺激大鼠肝星状细胞(Hepatic stellate cell,HSC)信号传导通路的影响.方法:体外分离、培养大鼠肝HSC,检测丹参素(O.062 5～0.2500 mmol/L)对TGFβ1促进HSC活化、HSC表达α-SMA和HSC表达Smad2、Smad3、Smad7 mRNA的影响.结果:丹参素(0.062 5-0.250 0 mmol/L)对TGFβ1引起的HSC增殖具有明显的抑制作用,并呈剂量依赖性(P相似文献   

细胞因子与肝星状细胞

星状细胞(HSC)的激活是肝纤维化发生、发展的关键步骤。HSC的激活是通过各种细胞因子(CK)经旁分泌或自分泌途径作用的结果,并且活化HSC的CK受体表达增加。随着对CK研究的逐渐深入,针对CK的治疗有望成为抗肝纤维化的一种重要手段。现就与HSC相关的CK综述如下:     

瘦素与肝纤维化

1994年Zhang等人通过定向克隆技术首次发现了ob基因和该基因编码的蛋白产物—瘦素,瘦素的发现给肥胖及能量代谢领域带来了一次重大突破。瘦素不仅仅只对能量代谢起作用,它在病理生理学上的影响涉及许多系统。     

丹参素对大鼠肝星状细胞氨基末端蛋白激酶信号转导的影响

Objective To investigate the inhibitory effect of danshensu on the activation of JNK signaling in rat hepatic stellate cells (HSCs) induced by IL-1 β. Methods The proliferation of primary rat HSCs treated with different concentration of Danshensu was checked by MTT colorimetric assay. The expres-sion and phosphorylation of JNK and P-JNK was detected by western blotting. Synthesis and secretion of collagen Ⅰ were detected by the quantitative immunocytochemical assay and ELISA. Results Danshensu inhibited the proliferation of HSCs in a dose-dependent manner. At the concentration of 0.0625 to 0.25 mmol/L, Danshensu significantly repressed the proliferation of HSC induced by IL-115 (P < 0.05). Synthesis and secretion of Type β collagen was significantly decreased 24 hours after 0.25 mmol/L Danshensu treatment (P < 0.01). The phosphorylation of JNK induced by IL-1 β was significantly inhibited by Danshensu treatment (P < 0.05), however, the expression of JNK was not regulated by Danshensu. Conelutions Danshensu represses the activation and proliferation of HSCs, and inhibits the synthesis and secretion of Type β collagen, possibly via the repression of the JNK signal transduction.     

三七总皂甙诱导大鼠肝星状细胞凋亡的研究

三七及其主要有效成分三七总皂甙（PNS）具有抗肝纤维化作用。采用体外培养的传代大鼠肝星状细胞（HSC），利用有关凋亡检测技术，观察PNS对LISC增殖、调亡，胶原和层黏连蛋白（LN）合成的影响，从细胞水平探讨PNS抗肝纤维化机制。     

丹参素对大鼠肝星状细胞氨基末端蛋白激酶信号转导的影响

Objective To investigate the inhibitory effect of danshensu on the activation of JNK signaling in rat hepatic stellate cells (HSCs) induced by IL-1 β. Methods The proliferation of primary rat HSCs treated with different concentration of Danshensu was checked by MTT colorimetric assay. The expres-sion and phosphorylation of JNK and P-JNK was detected by western blotting. Synthesis and secretion of collagen Ⅰ were detected by the quantitative immunocytochemical assay and ELISA. Results Danshensu inhibited the proliferation of HSCs in a dose-dependent manner. At the concentration of 0.0625 to 0.25 mmol/L, Danshensu significantly repressed the proliferation of HSC induced by IL-115 (P < 0.05). Synthesis and secretion of Type β collagen was significantly decreased 24 hours after 0.25 mmol/L Danshensu treatment (P < 0.01). The phosphorylation of JNK induced by IL-1 β was significantly inhibited by Danshensu treatment (P < 0.05), however, the expression of JNK was not regulated by Danshensu. Conelutions Danshensu represses the activation and proliferation of HSCs, and inhibits the synthesis and secretion of Type β collagen, possibly via the repression of the JNK signal transduction.     

结缔组织生长因子与肝纤维化的研究进展

肝纤维化是大多数慢性肝病共有的组织学改变,因此,能否终止肝纤维化的进展甚或逆转至正常,是治疗慢性肝病的关键.在肝纤维化的发病机制及治疗研究中,细胞因子网络始终是人们研究的热点.结缔组织生长因子(connective tissuegrowth factor CTGF)是一种新发现的细胞因子,1991年由Bradham等从人脐静脉内皮细胞(HUVEC)培养液中分离所得,为富含半胱氨酸的多肽.目前,CTGF在肝纤维化的研究中已成为新的热点.本文就CTGF的结构,生物学特性,主要调节因素及其与肝纤维化的关系作一综述.