Genotoxic assessment of anthracene and benzo [a] pyrene to milkfish Chanos chanos

Mutagenic and genotoxic effects of polycyclic aromatic hydrocarbons, anthracene and benzo [a] pyrene (BaP), in milkfish Chanos chanos were determined using micronucleus (MN) test and comet assay (CA). Distinct mean frequencies of nuclear abnormalities such as MNs; binucleated micronuclei, nuclear bud, and fragmented apoptotic cells were measured. Significant increase in DNA damage with five classes of damage level was observed and expressed in terms of arbitrary unit (AU). Mean frequencies of total nuclear abnormalities were 0.5?±?0.25 cells in control; 0.67?±?0.33 cells in solvent control; 70?±?9.60 cells in 0.176?mg?L^?1 anthracene, and 91.83?±?6.25 cells in 0.031?mg?L^?1 BaP. The greatest DNA damage of 170AU was observed in 0.176?mg?L^?1 anthracene-exposed group and 182AU was observed in 0.031?mg?L^?1 BaP-treated fish. This study confirmed that the CA and MN assays are useful tools in determining potential genotoxicity of water pollutants and might be appropriate as a part of monitoring program.     

Molecular level toxicological evaluation of a dental composite implanted in albino rats

Dental composite (DC) resins are synthetic resins which are used as restorative material or adhesives in dentistry. Monomers and other components released into the oral environment from the DC material even after polymerization might affect the surrounding tissues and even the whole body gradually. Biocompatibility of DC has to be stringently evaluated since the fillings are in close contact with mucosa, tooth, and pulp. Common difficulties with various current dental materials include allergies, chemical leakage from the material, and pulpal irritation which are due to the byproducts of chemical reactions during different stages of material hardening. Dental Products Laboratory of Sree Chitra Tirunal Institute for Medical Sciences and Technology developed a new BIS-GMA-based DC. In this study the oxidative stress induced by this DC material in vivo was tested for a period of 1, 4, 8, 26, or 52 weeks in albino rats. Dental materials were implanted intramuscularly into the gluteus muscle and oxidative biomarkers such as lipid peroxidation, 8-oxo-deoxyguanosine (8-OHdG) concentration, and total glutathione content analyzed. Data showed no significant changes in antioxidant defense system and 8-OHdG levels in nuclear DNA of the tissue. Serum biochemical results confirmed that animals were in normal functioning physiological state.     

植物彗星实验及其在生态毒理监测中的应用

植物彗星实验(Comet assay)是近几年发展起来的一项检测DNA损伤的新技术,具有快速、简便、灵敏性高和可靠性强等特点.本文总结了近年来国内外植物彗星实验的研究成果,详细介绍了植物彗星实验方法及其在生态毒理学中的应用.     

人血淋巴细胞检测浊漳河地表水的遗传毒性

为评价浊漳河水体中有机污染物的致突变性,采用单细胞凝胶电泳(SCGE)技术,研究了浊漳河水体3个不同样点的有机提取物对人外周血淋巴细胞DNA损伤效应。结果显示,各水样中的有机提取物均能引起DNA损伤,且随剂量的增高,有机物对DNA的损伤加重;细胞DNA损伤与对照组相比均有显著性差异(p<0.01)。这表明人外周血淋巴细胞对水体有机污染物的毒作用非常敏感。细胞彗星尾部DNA含量(%DNAT)和染毒剂量呈极显著正相关(R2>0.8547,p<0.01)。以上结果表明,浊漳河水体受到一定程度的有机物污染,这些有机污染物可诱导淋巴细胞DNA损伤,具有遗传毒性。SCGE技术作为一种简便、快速和灵敏的检测方法在水环境遗传毒性监测方面具有较大的应用价值。     

彗星实验技术及其应用

彗星实验是瑞典科学家Ostling和Johanson于1984年发明的检测毒物DNA损伤效应的方法。它经历了从最初的微电泳技术、中性彗星实验、碱性彗星实验、酶切彗星实验和双向垂直彗尾彗星实验等不断完善的发展过程。在毒理学、遗传学和环境生态科学等领域有着重要的应用,是经济合作与发展组织(OECD)和欧洲食品安全局等国际组织推荐的测定遗传毒性的方法之一。彗星实验的关键点包括单细胞悬液的制备、细胞裂解液的成分与比例,低熔点琼脂糖凝胶的浓度,电泳条件等。在典型应用领域,如蚯蚓、鱼、两栖动物、鼠和人的彗星实验很难找到标准实验方案。成功的彗星实验还需关注,实验设计时必须包括阳性对照,结果表述时必须有图为证,实验方案可能因物种或细胞而异。     

Statistical analysis of bioassays,based on hazard modelling

A stochastic model is proposed to describe time-dependent lethal effects of toxic compounds. It is based on simple mechanistic assumptions and provides a measure for the toxicity of a chemical compound, the so-called killing rate. The killing rate seems a promising alternative for the LC50. The model also provides the no-effect level and the LC50, both as a function of exposure time. The model is applied to real data and to simulated data.     

水环境中雌激素的酶联免疫快速生物筛选技术研究

采用酶联免疫(ELISA)检测技术,对来自长江口及污水处理厂的水样分析典型雌激素雌二醇(E2)的浓度,将检测结果与化学方法检测数据进行比较验证,以阐明ELISA应用于水环境雌激素快速筛选的可行性。结果表明:ELISA的检测限可低至0.5 ng/L,试验的变异系数<30%,具有较高的灵敏性和良好的重复性;ELISA检测长江口水样中E2浓度范围≤0.7 ng/L,污水处理厂水样为2.5～11.5 ng/L,与液相色谱串联质谱(LC-MS/MS)的检测数据进行比较分析,其相关系数R~2为0.9147,表明2种方法具有良好的相关性;ELISA检测所需的水样量比LC-MS/MS更少,使用96微孔板可同时对43个样品进行检测,缩短了多个样品的分析时间,具有快速简便、经济适用的特点。因此,ELISA作为1种快速、简便、灵敏的雌激素高通量筛选技术,可为环境保护部门开展水环境雌激素物质调查和水体雌激素快速诊断等工作提供技术支持。     

酶联免疫吸附法测定麻疯树核糖体失活蛋白

建立了一种检测麻疯树核糖体失活蛋白(Curcin)的简便、快速的酶联免疫吸附测定法(ELISA).ELISA条件优化试验结果显示:最佳条件为costar酶标板在紫外线下照射45 min后进行包被;抗原最适稀释度为1:640倍(2.5μg/mL);curcin抗血清最适稀释度为1:12 800倍;2%封闭用山羊血清封闭120 min;二抗最适稀释度为1:5 000倍.在此试验条件下检测curcin含量,得到回归方程y=31.722x+106.88,相关系数R2=0.993 3.Curcin浓度在0.08～11μg/mL之间,曲线呈良好的线性关系.本方法的最低检测限为0.08μg/mL.高、中、低3个浓度的添加回收率分别为95.56%、102.27%、98.40%,平均回收率为98.74%.板内和板间的平均变异系数分别为4.78%和6.71%.Curcin抗血清与2种大戟科同类蛋白均无交叉反应.利用本方法成功检测了麻疯树种仁及脱毒饼粕中的curcin含量.     

铀胁迫对大豆与玉米幼苗细胞DNA损伤的彗星试验研究

以铀浓度为1000 μmol·L-1、800 μmol·L-1、600 μmol·L-1、400 μmol·L-1、200μmol·L-1和100μmol·L-1的6组铀溶液和对照组(0μmol·L-1)培养大豆和玉米幼苗,采用彗星试验研究铀胁迫对大豆和玉米幼苗细胞DNA的损伤情况.试验结果表明,铀浓度为1 000 μ...     

The Cytotoxicity of Some Organic Solvents on Isolated Hepatocytes in Monolayer Culture

The cytotoxic effects of volatile and water-insoluble organic solvents (ethylbenzene, tetrachloroethylene, n-hexane) were tested on isolated hepatocytes in monolayer culture by using the 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) reduction assay. All of the tested compounds inhibited metabolic activity of hepatocytes and this effect depended on the concentration of solvents in the incubatory medium. The presence of fetal calf serum in the medium did not change the cytotoxicity of xenobiotics. IC₅₀ values calculated on the basis of the MTT assay indicated that ethylbenzene was more cytotoxic than tetrachloroethylene and n-hexane. Using hepatocyte monolayer culture and the MTT assay to assess cytotoxicity of organic solvents causes many technical problems. It seems that it cannot be used as a rapid, cheap, and credible method.