灵芝多糖对小鼠细胞免疫功能调节作用的实验研究

研究灵芝多糖 (GLB7)对小鼠细胞免疫功能调节作用的影响。实验小鼠分成 4组 ,分别经胃灌注不同剂量 (高、中、低 )灵芝多糖 ,每天 1次 ,连续 14d ,对照组小鼠用以等量蒸馏水代替。分别于实验第 15 ,2 8d进行小鼠细胞免疫功能调节作用的测试。灵芝多糖喂药后 2周 ,3个剂量组小鼠脾淋巴细胞转化试验、小鼠腹腔巨噬细胞对鸡血红细胞的吞噬百分率和吞噬指数 ;低剂量组小鼠迟发型变态反应 (DTH)、小鼠碳廓清 ;高剂量组小鼠NK细胞活性和对照组比较均有显著性差异 (P <0 .0 5 )。喂药后 4周 :上述实验结果和对照组比较均无显著性差异 (P >0 .0 5 )。结果提示灵芝多糖能提高小鼠的非特异性和特异性细胞免疫功能。  

三氧化二砷诱导人宫颈癌HeLa细胞凋亡及Bcl-2保护作用的机制研究

探讨三氧化二砷 (As₂ O₃)对人宫颈癌HeLa细胞的生物学效应和Bcl -2的高表达对这一效应的影响 .通过MTT ,克隆形成实验 ,形态观察 ,流式细胞仪 ,DNA凝胶电泳 ,细胞凋亡原位检测 (TUNEL) ,RT PCR ,Northernblot,Westernblot等方法发现As₂ O₃明显降低HeLa细胞存活率 ,并诱导其凋亡和细胞周期G2 /M期阻滞 ,分析显示As2 O3可能主要通过抑制c -myc基因和病毒致瘤基因的表达来诱导HeLa细胞凋亡 .Bcl -2的高表达也可能正是通过降低As₂ O₃对G2 /M期阻滞 ,逆转As₂ O₃对c -myc基因的降调节 ,减轻As₂ O₃对病毒致瘤基因的表达抑制作用 ,来部分阻止这种凋亡的发生 .我们还发现As₂ O₃能引起Bc1-2高表达HeLa细胞G2 /M期的弱阻滞 ,降调Bcl -2的表达以及略微抑制病毒致瘤基因的表达 ,这可能是As₂ O₃仍能诱导Bcl -2高表达HeLa细胞凋亡的原因 .  

真菌多糖等代谢产物的抗肿瘤药理研究综述

本文综述了真菌代谢产物（包括多糖及少量小分子）的抗肿瘤活性及其作用机理。  

腺病毒载体的应用及进展

腺病毒载体是近年来继逆转录病毒载体之后被广泛应用的一个基因运载系统。它具有宿主细胞广泛、繁殖滴度高、不整合及相对安全等特点，在基因治疗中发挥越来越大的作用。本介绍了Ｅ１区缺失为特征的第一代腺病毒载体应用的有效性、安全性等方面的研究情况，和旨在克服第一代腺病毒载体不足的第二代载体构建方面的进展。  

应用于基因治疗的重组体腺病毒的构建方法 Development of Adenovirus Recombinants for Gene Therapy

应用于基因治疗的重组体腺病毒的构建方法程金科林晨张雪艳吴（中国协和医科大学，中国医学科学院肿瘤研究所，北京１０００２１）ＤｅｖｅｌｏｐｍｅｎｔｏｆＡｄｅｎｏｖｉｒｕｓＲｅｃｏｍｂｉｎａｎｔｓｆｏｒＧｅｎｅＴｈｅｒａｐｙＣｈｅｎｇＪｉｎｋｅＬｉｎＣｈ...  

Hindmarsh-Rose 神经网络的混沌同步

研究了通过特殊构造的非线性函数耦合连接的神经网络的混沌同步问题。在发展基于稳定性准则的混沌同步方法的基础上,给出了计算同步稳定性的误差发展方程,当耦合强度取参考值时,可实现稳定的混沌同步而不需要计算最大条件Lyapunov指数去判定是否稳定。通过对按照完全连接形式构成的Hindmarsh-Rose神经网络的数值模拟,显示可仅从两个耦合神经的耦合强度的稳定性范围预期到许多耦合神经实现同步的稳定性范围。该方法在噪声影响下,对实现神经元的混沌同步仍具有较强的鲁棒性。此外发现随着耦合神经数的增加,满足同步稳定性的耦合强度减小,与耦合神经的数量成反比。  

Adenovirus-mediated transfer of RA538 gene and its antitumor effect

The RA538 cDNA was transferred into human ovarian cancer cell line SK-OV-3 and human melanoma cell line WM-983A by its recombinant adenoviral vector constructed through homologous recombination. It was demonstrated that the recombinant adenovirus could transfer RA538 gene with high efficiency, and could obviously inhibit tumor growth, with the inhibiting rates of 85% and 73% respectively, at the same time greatly repress the colony forming ability of the cells. The therapeutic experiments on transplanted subcutaneous tumor model in nude mice demonstrated that RA538 could significantly inhibit tumor growth. Flow cytometry and DNA fragmentation analysis indicated that RA538 could induce the cell cycle G1 arrest/apoptosis of the tumor cells. The expression of cmyc gene was found pronouncedly reduced by Western blot analysis. These results suggest that the RA538 recombinant adenovirus could be a promising drug in cancer gene therapy.  

Construction of shuttle, expression vector of human tumor necrosis factor alpha (hTNF-α) gene and its expression in a cyanobacterium, Anabaena sp. PCC 7120

The construction of the shuttle, expression vector of human tumor necrosis factor alpha (hTNF-a) gene and its expression in a cyanobacterium Anabaena sp. PCC 7120 was reported. The 700-bp hTNF cDNA fragments have been recovered from plasmid pRL-rhTNF, then inserted downstream of the promoter PpsbA in the plasmid pRL439. The resultant intermediary plasmid pRL-TC has further been combined with the shuttle vector pDC-8 to get the shuttle, expression vector pDC-TNF. The expression of the rhTNF gene in Escherichia coli has been analyzed by SDS-PAGE and thin-layer scanning, and the results show that the expressed TNF protein with these two vectors is 16.9 percent (pRL-TC) and 15.0 percent (pDC-TNF) of the total proteins in the cells, respectively, while the expression level of TNF gene in plasmid pRL-rhTNF is only 11.8 percent. Combined with the participation of the conjugal and helper plasmids, pDC-TNF has been introduced into Anabaena sp PCC 7120 by triparental conjugative transfer, and the stable transgenic  

Mechanisms of arsenic trioxide induced apoptosis of human cervical cancer HeLa cells and protection by Bcl-2

It was recently reported that arsenic trioxide (As_2O_3) can induce complete remission in patients with acute promyelocytic leukemia (APL). In this present article, the biological effect of As_2O_3 on human cervical cancer HeLa cells and HeLa cells overexpressing Bcl-2 is studied. By MTT and colony forming ability assays, morphology alteration, flow cytometric analysis, DNA gel electrephoresis and in situ cell death detection (TUNEL), it was found that As_2O_3 inhibited the growth of HeLa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR, Northern blot, Western blot analysis revealed that As_2O_3 induced HeLa cell apoptosis possibly via decreasing the expression of c-myc and viral genes. HeLa cells overexpressing Bcl-2 partly resist As_2O_3 induced apoptosis, which might be relative to preventing the cells from As_2O_3 caused G2/M block, downregulation of c-myc gene expression and inhibition of viral gene expression was also noted, However, it was found that As_2O_3 at a high concentratio  

腺病毒介导RA538基因转移及其肿瘤抑制作用

采用同源重组方法构建RA5 3 8cDNA重组体腺病毒 ,通过转导人卵巢癌细胞系SK OV 3和人黑色素瘤细胞系WM 983A ,证实腺病毒可高效转导RA5 3 8基因 ,能显著抑制肿瘤细胞的生长 ,其抑制率分别达 85 %和 73 % ;并显著降低两细胞系的集落形成能力 .对两细胞系的裸鼠皮下移植瘤进行治疗实验结果表明 ,RA5 3 8能明显抑制肿瘤的生长 .流式细胞计数和DNA片段化分析证实 ,RA5 3 8可引起肿瘤细胞G1期阻滞和 /或凋亡 .对c myc蛋白的Westernblot分析发现 ,RA5 3 8有明显下调c myc基因表达的作用 .根据这些结果 ,我们认为RA5 3 8重组体腺病毒有可能成为有应用价值的肿瘤基因治疗药物 .