雪貂和旱獭作为胃癌病因研究的实验模型

本项研究是以雪貂（Ｆｅｒｒｅｔ）和旱獭（Ｗｏｏｄｃｈｕｃｋ）作为实验动物模型，由于这两种动物的某些器官特征在解剖学上和生理学上与人类有其相似之处，试图通过雪貂和旱獭体内生物合成亚硝胺，说明人类暴露于化学致场物亚硝胺的另外一个来源是生物体内合成。同时，用烷基化学致癌物二甲基亚硝胺对旱獭进行ＤＮＡ烷基化的研究，发现由于被旱獭肝炎病毒（ＷＨＶ，ＷｏｏｄｃｈｕｃｋＨｅｐａｔｉｔｉｓＶｉｒｕｓ）感染的旱獭，不仅体内易于合成亚硝胺，而且其肝脏组织ＤＮＡ烷基化的水平高于对照组。以ＤＮＡ烷基化反应产生的烷化核酸碱基作为生物标志（Ｒｉｏｍａｒｋｅｒｓ），对于胃癌高发区人群尿中的烷化核酸碱基进行定量测定，并与低发区相对照，显示两者之间有差异性。本项研究为从动物实验外推到人群的设想提供了启示，还提出了以生物标志作为建立分子流行病学的依据。     

污染水体的总抗氧化能力生物标志物研究

以无污染饲养鲫鱼为监测生物,采取主动生物监测法(ABM)对太湖北部梅梁湖与贡湖污染区进行生物监测,并分析各监测点常规水质指标及表层沉积物中多环芳烃(PAHs)、多氯联苯(PCBs)、有机氯农药(OCPs)与重金属含量,同时定期(7,14,2,28d)采集生物样,分析鲫鱼大脑组织及肌肉组织中总抗氧化能力(TAOC)活性.结果表明,鲫鱼脑组织TAOC活性比肌肉组织TAOC活性值高出约4倍,并且对污染物协迫反应敏感.实验第14d开始,脑组织TAOC呈显著诱导效应(P<0.05),最大值出现在PCBs污染严重的梅梁湖4号站点,相比参照点活性增加62.19%.其次是重金属污染严重的梅梁湖3号监测点,而污染最小的贡湖1号监测点TAOC变化较小.肌肉组织中TAOC对污染物反应不敏感,不适合作微污染区生物标志物.     

水葫芦内生细菌脂肪酸生物标记特性研究（Characteristics of PLFA Biomarkers for the Endophyte Bacteria inside Eichhornia crassipe（Mart.）Solms）

应用基于微生物细胞脂肪酸成分鉴定的全自动微生物鉴定系统,鉴定水葫芦内生细菌25株,分属15个属.共检测到27个脂肪酸生物标记(PLFAs),这些生物标记分为4种类型,即(1)高频次分布:在25株细菌中出现13～22次,属于细菌总体类群(general)的生物标记.(2)中频次分布:在25株细菌中出现5～7次,可以用于代表细菌属类群(genus)识别生物标记.(3)低频次分布:在细菌中的分布概率较小,可以用于指示特定细菌种间差异的生物标记.(4)微频次分布:仅在一种细菌种类出现,是细菌种(species)特征生物标记.利用脂肪酸生物标记分析同属细菌不同种的差异,可将微杆菌属分为2类,第1类包括菌株9Microbacterium barkeri和11Microbacterium imperiale,这两个菌株17:0ISO和14:0ISO的脂肪酸生物标记含量均为0.第2类包括10Microbacterium esteraromaticum、12Microbacterium lacticum和13Microbacterium liquefaciens,这3个菌株均含有17:0ISO脂肪酸生物标记而区别于第一类菌株.利用脂肪酸生物标记的差异对25株内生细菌进行聚类分析,可将水葫芦内生细菌类群分为4类.不同植物内生菌群落中存在着特异的生物标记,利用特征脂肪酸生物标记的分析方法,分析水葫芦内生细菌的群体特性,对于植物内生菌微生物群落的研究具有重要意义.     

Physiological,biochemical and growth responses of Azolla pinnata to chlorpyrifos and cypermethrin pesticides exposure: a comparative study

Cypermethrin and chlorpyrifos pesticide- (5, 15 and 30 ppm) induced effects on growth, metabolic and antioxidative behaviour of Azolla pinnata were analysed after 96 h of treatment. Growth of A. pinnata was increased by 72–76% over the initial mass under control condition. Further, the growth was decreased by 26 and 30% following treatment with 5 ppm of cypermethrin and chlorpyrifos, respectively, compared to control. Whereas, 30 ppm of pesticide treatment caused substantial decrease in biomass accumulation, even less than the initial mass. The Chlorophyll a content was declined at higher concentrations of chlorpyrifos, while carotenoids content increased significantly in the presence of both the pesticides. Photosynthetic rate showed declining trend with rising concentration of pesticides, while an increasing trend was noticed in the case of respiratory O₂ consumption. The oxidative biomarkers malondialdehyde, superoxide radicals and hydrogen peroxide increased with increasing concentration of both the pesticides. The activity of enzymatic antioxidants enzyme superoxide dismutase, glutathione-S-transferase and ascorbate peroxidase (APX) was enhanced with increasing concentrations of both the pesticides; however, a declining trend was noticed in the case of APX at 30 ppm chlorpyrifos treatment. The study concludes that chlorpyrifos appeared to be more toxic than cypermethrin; however, both the pesticides significantly reduced the growth performance.     

Introduction of the land snail Cornu aspersum as a bioindicator organism of terrestrial pollution with the use of a suite of biomarkers

The use of organisms in biomonitoring studies allows the determination of the pollution levels, the assessment of the quality of the enviroment and the study of toxic effects of pollutants on the organisms. By studying the responses (biomarkers) of organisms, it is possible to assess the exposure and effects of pollutants. Land gastropods are widely used in relevant studies as they possess several characteristics that make them ideal for use as bioindicators. In the present study we sought to evaluate several biomarkers in the laboratory using snails of the species Cornu aspersum after the exposure to heavy metals (Cd, Hg) and a mixture of polycyclic aromatic hydrocarbons (PAHs) (anthracene, phenanthrene and naphthalene). The biomarkers studied were the following: lysosomic membrane stability using the neutral red retention assay (NRR), the production of reactive oxygen species (ROS) using the compound DCFH-DA and flow cytometry, lipid peroxidation using the TBARs assay that measures the concentration of malondialdehyde (MDA), protein carbonylation (–CO) using ELISA, and single strand breaks of DNA using the comet assay. Our results show significant differences in the responses between the control group and the groups that were exposed to pollutans, enhancing the role of Cornu aspersum as a promising bioindicator organism in terrestrial pollution studies with the use of the biomarkers applied.     

Biomarkers of oxidative status associated with metal pollution in the blood of the white stork (Ciconia ciconia) in Spain

The aim of this study was to determine the impact of specific environmental contaminants on the activities of antioxidant enzymes in terrestrial, free-living birds. To investigate this, several biomarkers and the levels of lead, mercury, and arsenic were determined in blood of white stork (Ciconia ciconia) nestlings from two different colonies located in the west of Spain that were exposed to different environmental conditions and human activities. Different biomarker and contaminant patterns were observed between the two colonies, suggesting different levels of environmental contamination. In comparison to nestlings from a natural reference area, the levels of the three hazardous elements Pb, As, and Hg were significantly higher in the colony nearby a landfill. Analysis of antioxidant biomarkers revealed significantly higher levels of glutathione and glutathione S-transferase activity in birds from the colony close to the landfill site than were found in those from the “control” area. In contrast, the levels of malondialdehyde did not significantly differ between the two sampling sites. In addition, a positive correlation between glutathione and both Hg and As has been observed. Taken together, exposure to the three hazardous elements is reflected by enhanced activity of glutathione S-transferases, and elevated levels of glutathione and malondialdehyde. White storks can therefore be considered as a suitable model species for environmental monitoring programs.     

The effects of anthracene on biochemical responses of Mediterranean mussels Mytilus galloprovincialis

Mediterranean mussels Mytilus galloprovincialis is among the most widely used bioindicators, and anthracene (AN) is one of the most commonly found hydrocarbons in the aquatic environment. M. galloprovincialis were exposed to nominal concentrations of 0.05, 0.15 and 0.4?μg/L AN. Chemical analysis using high-performance liquid chromatography revealed the uptake of AN in the whole soft body and digestive gland at different amounts. After a short exposure (2, 4 and 8 days), the results revealed that AN induced malondialdehyde (MDA), glutathione (GSH) and acetylcholinesterase (AChE) activity in digestive gland. Our findings demonstrated also that AN reduced the filtration rates in a concentration-dependent manner. Increase in lipid peroxidation (MDA content) in digestive gland (p?M. galloprovincialis, where digestive gland constitutes a valuable organ for investigating AN biotransformation and toxicity.     

水体沉积物毒性鉴别与评价研究进展

综述了水体沉积物毒性鉴别与评价的主流方法以及研究进展,指出毒性测试和致毒因子鉴别方法是限制水体沉积物污染生态风险评价的关键因素,认为发展和应用以生物标记物和生物效应为导向,尤其是各种具有污染专一性指示作用的生物效应标志测试方法的建立和应用,并结合具有选择性的样品分级技术和先进的仪器进行定性定量分析,将是以生物效应为导向、以化学分析为基础的复杂水体沉积物毒性鉴别与评价的重要发展方向.     

不同铅暴露区人体离体牙铅含量和年龄关系及指示意义

人体牙釉质是记录环境铅(Pb)暴露信息的较好载体。本研究采用微波消解-电感耦合等离子体质谱仪(ICP-MS)联用的方法测定来自高Pb暴露区(铅锌冶炼厂地区)和Pb暴露对照区(农业种植区)附近长期居住 /不同年龄段人体离体牙的Pb含量,结果显示：高Pb暴露区离体牙表现出Pb含量高且随居民年龄增长而增高的趋势,离体牙Pb含量从6—12岁儿童的(60.8±15.3) μg·g^-1增加到65岁以上老年人的(200.1±30.5) μg·g^-1;而铅暴露对照区人体离体牙Pb含量低且基本随年龄增长变化不大。Pb主要通过呼吸道和消化道进入人体并在牙齿中富集,因此,牙齿中的Pb含量与生活环境密切相关。研究结果表明：生活在高Pb暴露区的人群,环境中的Pb可能通过各种介质(空气、水、实物等)不断进入人体,其牙齿不断蓄积环境来源的Pb。因此人体离体牙Pb有可能作为人体长期Pb暴露生物标志物。     

氯代硝基苯胺对鲫鱼(Carassius auratus)血清抗氧化酶的影响

研究了2-氯-4-硝基苯胺、4-氯-3-硝基苯胺，2-氯-5-硝基苯胺对斑马鱼的急性毒性，96hLC50分别为6.99,2.58,8.63mg/L，为阐明氯化硝基苯胺类化合物对水生生物抗氧化酶的早期影响，将鲫鱼暴露于梯度浓度的2-氯-4-硝基苯胺，4-氯-3-硝基苯胺，2-氯-5-硝基苯胺中，研究鲫鱼血清SOD和GSH-PX活性短期（48h)内的变化，研究结果表明，在实验设置浓度下，随着暴露浓度升高，与空白对照组相比，3种化合物对SOD活性表现为先轻微激活后抑制，对GSH-PX活性先激活再抑制后有所回升，表明3种化合物对鲫鱼血清SOD和GSH-PX活性有显著影响，与3种化合物96hLC50相比，引起生化效应的暴露浓度明显降低，且反应快速，可考虑SOD和GSH-PX酶活性相结合作为该类化合物对水环境污染胁迫的敏感生物指示物。