Combined therapeutic effects of cytotoxic agent and differentiation-inducer on human gastric carcinoma cell line SGC-7901

Objective:To study the combined therapeutic effects of cytotoxic agent and differentiation-inducer on human gas tric carcinoma celll line SGC-7901 in vitro. Methods: The combined therapeutic effects of all-trans retinoic acid (ATRA), interferon a (IFNa)and fluorouracil (5-Fu) on gastric carcinoma cell line ax 7901 were observed when one of the 3, the combination of any 2 of the 3 and combination of all the 3 were administered respectively. The morphological and functional changes of gastric carcinoma cells were studied with MTT assay, flow cytometry, image analysis and determination of CEA content in the culture medium of the cells. Results: The cytostatic rate was increased as shown by the decrease of the rate of colony formation of the cells on culture disc when one agent, the combination of 2 agents and the combination of the 3 were administered progressively. The cells were relatively accumulated in the phase of G0/G1 and synthesis of DNA in he cells was inhibited.The malignant phenotype of the cells disappeared gradually while the characteristics of matUre cells were in creased. Meanwhile, CEA Level in the culture medium was decreased progressively. Apoptosis of the cells was oborved and a large amount of apoptotic apoptotic were found. Conclusion: The administration of the 3 agents in combination result in signif icant inhibition on proliferation, inducing of differention and promotion of apoptosis of gastric caxcinoma cells. The combina tion of cytotoxic agent and differention-inducer exerts significant inhibition on gastric carcinoma cells in vitro.

Id1-p53调控血管新生参与高切应力介导的易损斑块形成的机制

目的本课题组针对至今难以解释临床上动脉粥样硬化(As)易损斑块发生在高切应力区域的现象,在前人和本室前期研究基础上,从血管新生的视角入手,提出血管新生是导致As易损斑块发生在狭窄上游高切应力区域的重要因素、切应力通过Id1-p53信号通路调控血管新生的理论假设,并通过实验予以验证。方法通过动物模型和体外实验相结合研究切应力如何调控斑块内血管新生和易损斑块的形成及Id1-p53信号途径调控血管新生的机制。结果通过构建兔颈动脉狭窄模型发现,易损斑块主要发生在狭窄血管近心端的高切应力区域,高切应力区域斑块内有大量的血管新生,并且大部分的新生血管为周细胞、外膜不完整的容易破裂的微血管。体外实验的研究发现转录因子Id1蛋白的表达和分布受切应力和氧化型低密度脂蛋白的调控。并且Id1-p53信号通路是切应力和氧化型低密度脂蛋白调控血管新生的重要信号通路。目前正进一步通过使用血管新生抑制剂TNP-470在体验证血管新生就是高切应力引起易损斑块形成的重要因素。结论斑块形成引起的狭窄血管近心端的高切应力主要是通过促进斑块内血管新生引起易损斑块的形成,Id1-p53信号通路是切应力调控血管新生的重要信号通路。本研究不仅有助于阐明易损斑块在高切应力区域的发生机制,明确动脉粥样斑块内血管新生在切应力介导的As易损斑块形成中的作用,而且将为易损斑块的临床治疗提供新的靶点。

张杂谷穗分化时期与叶龄指数关系的研究

以2个杂交谷子新品种为材料,连续两年在田间自然播种条件下进行杂交谷子叶龄指数与穗分化时期回归关系的试验研究。结果表明,各品种的叶龄指数与穗分化时期之间均呈极显著的正相关关系,回归方程的检验达极显著水平。可利用回归方程,依据叶龄指数的观测值来预测穗分化时期。

从“消极差别化”到“积极差别化”——义务教育资源配置政策的创新逻辑

通过对义务教育政策变迁的"路径依赖"分析,探讨了义务教育城乡失衡问题的制度根源及其破解路径。国家对农村教育和城市教育实行不同的资源分配政策,导致了义务教育发展的城乡失衡。要促进义务教育的均衡发展,必须实行重点向农村倾斜的积极差别化政策,在财政投入、师资力量、资金援助等方面优先考虑农村,以推动农村义务教育的快速发展。

我国转租制度的困境与出路

转租是有别于租约让与和普通租赁的特殊租赁形式。在转租方面,世界各国立法大致可分为自由主义、限制主义和区别主义三种模式。我国《合同法》第224条关于转租的规定采限制主义,这虽然减轻了司法任务,促成了判决统一,但因不区分转租与租约转让且不分租赁之具体情形一概加以限制未免显得过于笼统,且该规定本身有违公平原则。在当前政治经济背景下,平衡当事人之利益显得尤为重要。借鉴自由主义的立法模式对现有制度予以修正,并对民事和商事租赁进行区别,对动产和不动产租赁采取不同规则具有重要意义。