低剂量微囊藻毒素亚急性肝毒性及其机理

为了研究低剂量微囊藻毒素 (MC)的亚急性肝毒性及其作用机理 ,将SD大鼠随机分为 4组 ,每组雌雄各 1 0只 ,分别经腹腔注射MC 0 ,4,8,1 2 μg·(kg·d) - 1,3 5天后观察各组大鼠血清酶学和肝脏病理学变化 .用原位末端标记法 (TUNEL)观察肝细胞凋亡 ,并用ABC免疫组化技术检测肝脏增殖细胞核抗原 (PCNA) .结果表明染毒组大鼠血清γ 谷氨酰转移酶 (GGT)活力和全血谷胱甘肽 (GSH)浓度下降 ,血清乳酸脱氢酶 (LDH)和谷草转氨酶(AST)升高 ,谷丙转氨酶 (ALT)未见显著变化 .染毒组大鼠肝脏出现特征性的形态学变化 ,并有活跃的肝细胞凋亡和增生并存的现象 .说明微囊藻毒素引起的氧化损伤和肝细胞凋亡可能是其致肝脏毒性的原因     

汉江下游突发“水华”的调查研究

对１９９２年春汉江下游水体暴发“水华”进行了调查研究，对“水华”的特征，产生的原因以及对策，建议等进行了分析、探讨。结果表明，其直接原因是以小环藻为主的硅藻的急剧增殖造成的。     

The effect of oxygen tension on colony formation and cell proliferation of amniotic fluid cellsin vitro

The effects of reduced oxygen concentrations in the gas phase over the culture medium on colony formation and cell proliferation were investigated in high and low cell density primary and secondary cultures of amniotic fluid cells. Using two standard culture methods (25 cm² plastic flasks and Leighton type tubes) a significantly reduced culture time was observed at high cell density for mass cultures by incubation within a low oxygen tension gas phase (2.5 per cent to 7.5 per cent O₂) instead of conventional air (18 per cent O₂). At low cell density colony formation was significantly enhanced in cultures grown at reduced oxygen tension. Using gas permeable membranes as support, lowering the oxygen tension from 7.5 per cent to 2.5 per cent yielded an increase in plating efficiency of cells from approximately 5 per cent to 25 per cent, whereas plating efficiency was less than 2 per cent for cells grown at ambient 18 per cent O₂. It is suggested that low oxygen tension in the gas phase is an effective means of enhancing clonal growth in amniotic fluid cell cultures, thereby reducing both culture time and risk of culture failure.     

山区和平原连接处SF6试验及扩散规律研究

为更好了解污染物在复杂地形条件下的湍流扩散规律,2010年9月开展了一系列SF6示踪扩散试验,获取了SF6浓度数据,以此实验数据为基础,计算出SF6浓度分布在水平和垂直方向的扩散标准差、地面峰值浓度等参数,并与P-T-C扩散参数进行对比,总结得出了污染物在山区和平原连接处中性、稳定、强稳定等气象条件下湍流扩散规律。     

Alterations in the rabbit lymphoid tissue after bendiocarb administration

Various pesticides have immuno-suppressive effects, and thus the organisms become responsive to viral, bacterial and parasitic diseases and neoplasm. The aim of the study was to observe the structure of the small intestine (height of enterocytes and crypts), mucosal lymphoid tissue (Payer's patches, lymphocytes in lamina propria) and a lymph node after administration of bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-yl-methylcarbamate) on days 3, 10, 20, 30 and 60 of the experiment. The height of the observed enterocytes showed an increasing tendency. On days 20, 30 and 60 we also observed an increase in diameter of crypts located in intestinal epithelium. The number of cells in lamina propria mucosae was significantly reduced on days 20 and 30 after administration of bendiocarb. Observations of the lymph node showed that on days 10 and 20 there was a significant increase in relative volume of medulla at the expense of the relative volume of the cortex and a decrease in the number of lymphocytes. However, we recorded an increase in diameter of lymphocytes. The intracellular parasite Toxoplasma gondii (T. gondii) belongs to the most common pathogenic parasites in the world and it can cause serious health complications in pregnant and immunodeficient individuals. DNA isolation, standard polymerase chain reaction (PCR) and visualization in a 2.5 % agarose gel, the presence of DNA T. gondii was detected in no examined rabbit brain samples. Using real time PCR T. gondii DNA was detected and quantified in the three rabbit brain samples (10 %).     

Toxicological characterization of the landfill leachate prior/after chemical and electrochemical treatment: A study on human and plant cells

In this research, toxicological safety of two newly developed methods for the treatment of landfill leachate from the Piškornica (Croatia) sanitary landfill was investigated. Chemical treatment procedure combined chemical precipitation with CaO followed by coagulation with ferric chloride and final adsorption by clinoptilolite. Electrochemical treatment approach included pretreatment with ozone followed by electrooxidation/electrocoagulation and final polishing by microwave irradiation. Cell viability of untreated/treated landfill leachate was examined using fluorescence microscopy. Cytotoxic effect of the original leachate was obtained for both exposure periods (4 and 24 h) while treated samples showed no cytotoxic effect even after prolonged exposure time. The potential DNA damage of the untreated/treated landfill leachate was evaluated by the comet assay and cytokinesis-block micronucleus (CBMN) assay using either human or plant cells. The original leachate exhibited significantly higher comet assay parameters compared to negative control after 24 h exposure. On the contrary, there was no significant difference between negative control and chemically/electrochemically treated leachate for any of the parameters tested. There was also no significant increase in either CBMN assay parameter compared to the negative control following the exposure of the lymphocytes to the chemically or electrochemically treated landfill leachate for both exposure periods while the original sample showed significantly higher number of micronuclei, nucleoplasmic bridges and nuclear buds for both exposure times. Results suggest that both methods are suitable for the treatment of such complex waste effluent due to high removal efficiency of all measured parameters and toxicological safety of the treated effluent.     

3种增塑剂单独和联合暴露对MCF-7细胞增殖的影响

为了探究结构差异较大、应用较为广泛的几类增塑剂雌激素活性的联合效应,选择邻苯二甲酸二丁酯(DBP)、双酚A(BPA)和壬基酚(NP)作为邻苯二甲酸酯、双酚A类和烷基酚类增塑剂的代表物进行试验.用DBP、BPA和NP单独及两两混合处理MCF-7细胞.采用MTT法检测培养24h、48 h、72 h和96h时的细胞增殖情况.采用流式细胞术检测药物培养48h后的细胞生长周期分布,并计算细胞增殖指数(PI).运用效应叠加模型(ES)判定联合效应类型.结果表明,在单独暴露试验中,DBP、BPA和NP组PI均大于1,且均能提高S期(DNA合成期)细胞比例.因此,DBP、BPA和NP均能显著促进MCF-7细胞增殖.混合暴露试验中,1)DBP和BPA在MTT试验中24h、48h、72 h和96h时的效应叠加指数(ESI)分别为1.013 9、1.023 8、0.9999、1.010 8,在流式细胞仪试验中ESI为1.014 1.因此,DBP和BPA的雌激素活性联合效应为加和作用.2)DBP和NP在MTT试验中24 h、48 h、72 h和96 h时的ESI分别为1.004 0、1.008 6、1.011 5、1.010 3,流式细胞仪试验中ESI为0.997 0.因此,DBP和NP的雌激素活性联合效应为加和作用.3)BAP和NP在MTT试验中24h、48 h、72 h和96h时的ESI分别为0.980 6、0.981 8、0.977 7、0.973 3,流式细胞仪试验的ESI为0.912 8.由此可知,BPA和NP的雌激素活性联合效应为拮抗作用.因此,可以采用MCF-7细胞增殖试验研究环境污染物雌激素活性联合效应.     

不同分化形态的嗜肺军团菌对嗜热四膜虫BF1的感染和胞内增殖特征

嗜肺军团菌是一种广泛分布于淡水生态环境中的条件性胞内致病菌,其不同的分化形态与菌体的存活、感染力和毒力有密切关系.本文对不同分化形态的表达绿色荧光蛋白的嗜肺军团菌在不同感染复数(multiplicityofinfec-tion,MOI)下感染嗜热四膜虫BF1株的条件以及胞内增殖的特征进行了研究.结果表明,胞内的军团菌比大肠杆菌有更强的抗消化能力,30℃时处于对数生长期的嗜肺军团菌即使在MOI等于100的情况下仍然在24h内被四膜虫消化殆尽,而平板培养至稳定期的菌体即使MOI只有50即可实现胞内增殖,并在18h内使宿主数量急剧下降.饲喂军团菌后,四膜虫都有一个数量先上升的过程,然后依MOI的不同呈现稳定或下降的趋势.本文还通过荧光显微镜观察描述了一定MOI下四膜虫对稳定期菌体的消化和形态变化的动态过程.图7参14     

白眉蝮蛇毒精氨酸酯酶对CHL细胞增殖抑制和染色体畸变的影响

研究了蝮蛇清栓酶的有效成分精氨酸酯酶体外对中国仓鼠肺成纤维细胞 (CHL)增殖和染色体畸变的影响 .精氨酸酯酶的浓度以酶活单位U表示 .细胞增殖抑制试验和染色体畸变试验都用两种方法 :直接法和代谢活性法 .精氨酸酯酶设 3个浓度 :1.0× 10 -3 U /mL ,0 .5× 10 -3 U /mL和 0 .2 5× 10 -3U/mL .其中最高浓度比临床治疗浓度高约10 0倍 .细胞增殖抑制试验采用细胞贴壁培养 ,乙醇固定 ,结晶紫染色 ,单层细胞密度计测定细胞密度 .染色体畸变试验采用给药后 2 4h和 48h收集中期分裂细胞 ,低渗固定 ,制片 ,Giemsa染色 ,观察 10 0个中期分裂细胞的染色体结构异常及多倍体的出现率 .试验结果表明 ,精氨酸酯酶在上述浓度对CHL细胞的增殖没有抑制作用 ,对CHL细胞的染色体结构也没有影响 .表 2参 10     

长江、嘉陵江(重庆段)源水有机提取物的类雌激素活性评价

为了解长江、嘉陵江(重庆段)源水有机提取物的类雌激素活性，分别于夏季和冬季采用GDX—120大孔树脂对位于城区上、中、下游5个断面长江、嘉陵江(重庆段)源水进行有机物的浓缩提取。用体外MCF—7细胞增殖试验检测有机提取物的类雌激素活性。结果显示，源水有机提取物均具有类雌激素活性。其类雌激素活性中、下游均高于上游，丰水期高于枯水期。