Oxidatively Damaged DNA: A Possible Antigenic Stimulus for Cancer Autoantibodies

Reactive oxygen species (ROS) are cytotoxic at higher concentration resulting in cell death, mutations, chromosomal aberrations or carcinogenesis. In this study DNA was modified by singlet oxygen and superoxide anion radicals generated by illumination of riboflavin under 365 nm UV-light. The modified DNA induced high titre antibodies in experimental animals. In enzyme immunoassay, serum antibodies from cancer patients (n = 34) showed a higher recognition of the modified DNA, as compared to the native form. This was further confirmed by the gel-shift assay. Immune IgG were used as a probe to detect oxidative lesions in the DNA of cancer patients. DNA isolated from lymphocytes of cancer patients proved to be an appreciable inhibitor of the experimentally induced antibodies against the ROS-DNA. This indicates the presence of oxidative lesions in the DNA obtained from cancer patients. The results show that ROS induced oxidative damage to DNA in cancer patients generate neo-epitopes that are alien for the immune system, resulting in autoantibody formation.     

耐力训练下调的HDMCP 表达对非酒精性脂肪肝线粒体活性氧 生成的影响

目的:研究耐力训练对非酒精性脂肪肝HDMCP表达的影响及与活性氧生成的关系.方法:以西方膳食诱导的脂肪肝小鼠为模型,跑台运动为训练手段,测定肝脏HDMCP及MnSOD表达,顺乌头酸酶和MnSOD活性,MDA、OH·-含量的变化.结果:非酒精性脂肪肝小鼠模型组肝脏MnSOD与HDMCP表达显著升高,顺乌头酸酶活性显著下降,MnSOD活性显著升高,MDA和OH·-含量显著升高;耐力训练后MnSOD表达进一步升高,而HDMCP表达显著降低,顺乌头酸酶活性得到明显恢复,MDA和OH·-含量显著降低,MnSOD活性进一步升高.结论:HDMCP在非酒精性脂肪肝发病过程中可能作为一种应激蛋白,调控线粒体活性的生成,但其调控作用不能够完全代替抗氧化系统的作用,只是起辅助作用,抗氧化系统才是真正的抗氧化主体;耐力训练后,抗氧化系统能力进一步增强,HDMCP表达降低,从而提高线粒体偶联程度,增强线粒体ATP合成能力.     

紫外线技术处理船舶压载水的可行性研究

船舶压载水对保证船舶稳性和航行安全起着至关重要的作用。然而船舶压载水中带有的病原体和有害生物也随压载水在全球范围内一起转移 ,污染海洋 ,危害人类。本文对控制船舶压载水中的病原体和有害生物传播进行了分析 ,提出了用紫外线技术处理船舶压载水的方案 ,并就其可行性进行了探讨。     

说“实”论“虚”——解读《高老庄》

“实”与“虚”两个层面所具有的意义是《高老庄》中所包蕴的主要思想内核。“实”的一面续写了90年代末商州农民的浮躁心态,“虚”的一面则继承了从沈从文开始的“种的退化”的忧思。后一个层面意义主要由一系列象征意象组合推演而成,并探究了为汉民族“换种”的可能性。     

自然湿地甲烷排放时空变化规律研究（英文）

对三江平原沼泽湿地甲烷排放时空变化规律及其影响因素进行了研究。自然湿地甲烷排放存在着明显的季节性变化,即随着植物生长甲烷排放量不断增加,在8月未达到最大值,而后下降。这一变化特点主要受温度和沼泽静水层深度所控制。春季低温不仅直接降低了甲烷的产生强度,而且也降低了其它好氧微生物的活性,使得沼泽水中存留较多的氧气,这些氧气直接加速了沼泽水中甲烷氧化,同时又提高了沼泽水的氧化还原电位,后者反过来进一步减缓甲烷的产生。三江平原不同植被生长的沼泽甲烷排放通量呈如下特点：毛果苔草>乌拉苔草>小叶章。莎草科植物生长的沼泽中,72-86%的甲烷通过植物排放进入大气,而小叶章生长的沼泽只有28-31%。毛果苔草促进了沼泽水中甲烷的氧化而不是产生,相反小叶章通过释放根系分泌物刺激甲烷产生的能力大于分泌氧气促进甲烷氧化的能力。毛果苔草沼泽水中更高的甲烷浓度是由于深的静水层淹没更多的植物立枯,从而为产甲烷菌提供充足的底物所致。     

五种五味子属药用植物及东紫苏的化学成分和生物活性研究

对五种五味子属(Schisandra)药用植物（小花五味子Schisandra micrantha,狭叶五味子S. lancifolia,滇翼梗五味子S. henryi var. yunnanensis var. yunnanensis,复瓣黄龙藤S. Plena,华中五味子S. sphenanthera）和唇形科植物东紫苏 (Elsholtzia bodinieri) 的化学成分进行了研究,从中共分离鉴定了101个化合物,26个为新化合物。首次从3种五味子属植物中发现了3种高度氧化的新奇骨架类型。此外,还发现了18,19-seco-乌索酸型苷和17,20断裂并失去17位侧链的羊毛甾烷型和环阿尔廷型八降三萜等新的骨架类型。 对分离得到的部分化合物进行了体外抗HIV-1、急毒、抗炎和抗肿瘤活性实验,发现部分化合物具有抗HIV-1活性。其中化合物SM-10和SM-26具有显著的抑制HIV-1病毒活性,选择指数分别为174.08和 >25.04。且毒性较小,作为作用于病毒与细胞结合和融合靶点的小分子化合物具有重要的意义。     

纤维素吸水材料

文章简要综述了纤维素吸水材料的种类及研究进展。     

A note on Chinese Bamboo paper: The impact of modern manufacturing processes on its photostability

Papermaking has a special place in the cultural heritage of China. Papers made from different types of plant fibers were, and are still used for particular applications. Bamboo paper is a handmade paper that has been traditionally used for book printing and restoration of ancient paper objects since antiquity in China, whereas Xuan paper, the subject of recent previous study, is used for traditional Chinese calligraphy and painting. Following our previous approach on Xuan paper, four modern Bamboo papers manufactured using traditional or chemically-facilitated techniques were artificially aged by UVA radiation and changes to their optical properties were evaluated by reflectance and 3D-fluorescence spectroscopies. Paper samples produced by different methods displayed different fluorescence spectra and UVA photolysis of paper resulted in decreases in the fluorescence intensities and reflectance values, manifested as differing photoyellowing of the papers. Assays of reactive oxygen species, ROS, revealed that papers made by chemically-assisted pulping methods generally produce more hydrogen peroxide or superoxide radicals than those made by traditional methods, which correlates with their relative yellowing rates. Different spatial distributions of calcium and chlorine were also observed by SEM/EDS analysis in the chemically-manufactured papers, probably arising from the specific pulping and/or bleaching chemicals used in their manufacture.     

Allergens/Antigens,Toxins and Polyketides of Important <Emphasis Type="Italic">Aspergillus</Emphasis> Species

The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important species relevant to human, agricultural and biotechnological applications. The potential of Aspergillus species to produce highly diversified complex biomolecules such as multifunctional proteins (allergens, antigens, enzymes) and polyketides is fascinating and demands greater insight into the understanding of these fungal species for application to human health. Recently a regulator gene for secondary metabolites, LaeA has been identified. Gene mining based on LaeA has facilitated new metabolites with antimicrobial activity such as emericellamides and antitumor activity such as terrequinone A from A. nidulans. Immunoproteomic approach was reported for identification of few novel allergens for A. fumigatus. In this context, the review is focused on recent developments in allergens, antigens, structural and functional diversity of the polyketide synthases that produce polyketides of pharmaceutical and biological importance. Possible antifungal drug targets for development of effective antifungal drugs and new strategies for development of molecular diagnostics are considered.     

过度运动激活中性粒细胞产生的活性氧对淋巴细胞DNA损伤及干预研究

目的:探讨过度运动激活中性粒细胞NADPH氧化酶介导产生的活性氧(ROS)对淋巴细胞DNA损伤的影响及实施二联苯碘(DPI)干预作用.方法:30只雄性Vistar大鼠随机分为3组,安静组(C,n=10)、过度训练组(E,n=10)和DPI干预组(D,n=10),E组和D组进行递增负荷跑台训练11周,末次训练结束后在36～40 h内各组随机取8只眼眶静脉采血.应用ELISA方法检测血浆细胞因子水平及血液中脂质过氧化水平;提取白细胞用AnnexinV/PI双染色法流式测定中性粒细胞凋亡与坏死程度;免疫细胞化学的激光共聚焦法测定NADPH氧化酶关键亚基的gp91 phox与p47phox的共定位;单细胞凝胶电泳测定淋巴细胞的DNA损伤程度.结果:1)与C组比较.E组血浆IL-1b显著性升高,IL-8、TNF-α显著升高(分别为P＜0.01和P＜0.05),MCP-1与CINC显著性下降(P＜0.05);而D组血浆IL-1b、MCP-1显著下降(P＜0.05),IL-8、TNF-α显著性升高(P＜0.05);E组和D组大鼠血浆慨、MPO水平均上升(分别为P＜0.01和P＜0.05);2)与C组相比,E组、D组中性粒细胞性凋亡的百分比均显著上升(P＜0.01),但中性粒细胞的死亡数E组增加(P＜0.05)而D组无显著变化;3)与C组比较,E组出现DNA损伤的彗星细胞数非常显著性升高(P＜0.01),且彗星细胞的宽度和尾长的变化均达到显著性水平,而D组的变化均未达到显著性水平;4)中性粒细胞的共聚焦染色定位显示:与安静组对照比较,E组出现了NADPH氧化酶关键亚基的gp91phox与p47phox的共定位.结论:1)过度运动可引起外周血炎性因子和趋化分子分泌的增加,从而有可能诱发组织炎症的发生和而调节T淋巴细胞的分化;2)过度运动可激活外周血中性粒细胞的NADPH氧化酶介导产生过多的ROS使血液的脂质过氧化水平提高;3)由此途径产生的ROS的增多和血液过氧化水平的提高可能引起中性粒细胞本身的凋亡甚至死亡和淋巴细胞的DNA损伤:4)由此途径产生的ROS的增多、吞噬细胞及淋巴细胞的过氧化损伤、炎性因子及免疫调节因子的变化等多因素可调节细胞免疫,是过度运动引起的运动型免疫抑制的可能因素.