Kinetic assessment of persistent halogenated xenobiotics in cell culture models: comparison of mono- and poly-halogenated compounds

We evaluated the suitability of single and multiple cell type cultures as model systems to characterise cellular kinetics of highly lipophilic compounds with potential ecotoxicological impact. Confluent mono-layers of human skin fibroblasts, rat astrocytoma C6 cells, non-differentiated and differentiated mouse 3T3 cells were kept in culture medium supplemented with 10% foetal calf serum. For competitive uptake experiments up to four different cell types, grown on glass sectors, were exposed for 3 h to ¹⁴C-labelled model compounds, dissolved either in organic solvents or incorporated into unilamellar lecithin liposomes. Bromo-, or chloro-benzenes, decabromodiphenylether (DBP), and dichlorodiphenyl ethylene (DDE) were tested in rather high concentration of 20 μM. Cellular toxicity was low. Compound levels were related to protein, DNA, and triglyceride contents. Cellular uptake was fast and dependent on physico-chemical properties of the compounds (lipophilicity, molecular size), formulation, and cell type. Mono-halogenated benzenes showed low and similar uptake levels (= low accumulation compounds). DBP and DDE showed much higher cellular accumulations (= high accumulation compounds) except for DBP in 3T3 cells. Uptake from liposomal formulations was mostly higher than if compounds were dissolved in organic solvents. The extent of uptake correlated with the cellular content of triglycerides, except for DBP. Uptake competition between different cell types was studied in a sectorial multi-cell culture model. For low accumulation compounds negligible differences were found among C6 cells and fibroblasts. Uptake of DDE was slightly and that of DBP highly increased in fibroblasts. Well-defined cell culture systems, especially the sectorial model, are appropriate to screen for bioaccumulation and cytotoxicity of (unknown) chemical entities in vitro.     

酵母Candida krusei对合成染料的脱色

通过筛选实验,从土壤中新分离到1株对活性艳红K-2BP具有明显脱色效果的酵母菌株Y-G-1,经鉴定为克鲁斯假丝酵母Candida krusei.该菌株对含活性艳红K-2BP起始浓度为200mg/L的培养基,最大脱色率为99%,达到最大脱色率的时间是12h.克鲁斯假丝酵母的最佳接种量应不低于5%(体积分数),培养基最适pH在4～9之间,氮源(NH₄)₂SO₄浓度不低于0.1%,相对应的碳源葡萄糖浓度不低于0.5%.对脱色机理的研究表明,该菌株对活性艳红K-2BP的去除属于降解脱色.此外,该菌株对另外9种染料(50mg/L)的脱色率在62%～96%之间.其中,对偶氮染料弱酸艳红B、活性黑KN-B和活性红M-3BE的脱色率都达到了90%以上,对三苯甲烷染料(酸性媒介漂蓝B)的脱色率达到了93%.表明克鲁斯假丝酵母在染料废水的处理上可能具有较好地应用潜能.     

高活性絮凝剂产生菌芽孢杆菌TS-1培养条件研究

从土壤中分离、筛选得到一株高絮凝活性絮凝剂产生菌,TS-1,初步鉴定为芽孢杆菌.通过六因素五水平正交设计实验,探讨了该菌产絮凝剂的最优条件.在最优条件为乳糖2%、蛋白胨1%、KH2PO4 0.2%、K2HPO4 0.2%、NaCl 0.05%、(NH4)2SO4 0.05%、MgSO4·7H2O 0.05%、pH 6.0、34℃、180r/min、摇床培养40h下,所产絮凝剂对4‰的高岭土悬浊液的絮凝效率为91.3%.     

电子产品环境应力筛选的技术及实施办法

环境应力筛选作为装备研制、生产中的一个非常重要的环节,结合有关标准,对环境应力筛选的作用、方法、裁减、实施办法等方面进行了阐述和论述。通过本文,使企业能够了解环境应力筛选的重要性,将此项工作落实到产品的研制/生产过程中,提高产品的可靠性,从而达到提升企业效益。     

我国土壤受试植物筛选与毒性预测

生态毒性数据缺乏是我国土壤基准与生态风险评估研究中一直存在的问题,开展本土受试植物的筛选可提供更多的生态毒理试验选材,从而获得不同物种的生态毒性数据.鉴于植物对土壤污染物的敏感性,从被子植物中依据分布范围、代表性和易于获得性等原则,对我国潜在的受试植物进行筛选,结果发现,13科53种被子植物分布广泛且易于获取,可作为本土受试植物;结合生态毒性数据的搜集与分析,其中12种受试植物的生态毒性数据相对丰富,并对部分典型污染物表现高敏感.此外在受试植物生态毒性预测模型研究方面,对12种受试植物两两进行建模预测,共得到132个物种种间关系估算模型(Interspecies Correlation Estimation,ICE),其中88个为显著性模型(F检验P<0.05);此处,回归分析了已构建ICE模型的评价参数,得出预测效果较好的ICE模型应满足交叉验证成功率≥ 80.00%、MSE ≤ 0.62、R² ≥ 0.76和分类学距离≤ 4的标准.最终筛选出25个符合上述标准的ICE模型,涉及禾本科-禾本科、十字花科-十字花科的相互预测,其中当燕麦Avena sativa、芜青Brassica rapa、普通小麦Triticum aestivum、玉蜀黍Zea mays和黑麦草Lolium perenne等作为替代物种时,预测物种的实际生态毒性值与预测值较为接近.受试植物的筛选与生态毒性预测模型的建立有助于生态毒性数据的产生,并为土壤污染管理和生态风险评估提供科学依据.     

有毒有害大气污染物排放源快速筛查方法的建立与应用

立足风险的环境管理是我国未来环境管理工作的核心任务.有毒有害大气污染物(HAPs)对人体健康有较大的危害,需要加强健康风险评估,并从源头上加以管控.针对我国当前缺乏HAPs排放源的快速筛查方法,利用监测数据和空气扩散模型,建立基于人体致癌/非致癌风险水平(R/H)、与风险源距离(D)和危害区域敏感程度(E)的三因素(R/H-D-E)风险分级矩阵,实现HAPs排放源的快速筛查,并将本方法应用于大型面源(化工园区)和分散源(加油站)的快速筛查.结果显示,化工园区符合“R2-D2-E3”和“H1-D2-E3”矩阵分布,被评价为高风险源;加油站符合“R2-D1-E2”和“H1-D1-E2”矩阵分布,被评价为低风险源.经检验分析,该方法的风险等级划分合理可行.相比国外同类方法,本方法可操作性强、适用性广,可为我国HAPs风险源的快速筛查和评估提供关键技术,服务于国家和地方大气风险源的管理.     

Prenatal diagnosis of Bruck syndrome

Bruck syndrome is an autosomal recessive connective tissue disorder combining features of osteogenesis imperfecta and arthrogryposis multiplex congenita. There are only few reports describing this rare syndrome of multiple fractures and joint contractures that is thought to be a subtype of osteogenesis imperfecta. We report the first case of prenatal diagnosis of this syndrome in a fetus at 23 weeks of gestation. Ultrasound findings included brachycephaly, retrognathia marked shortening and bowing of both femurs, bilateral fixed flexion of the elbows, bilateral fixed extension of the wrists and partially fixed flexion of the knees. The parents opted for termination of pregnancy. Macroscopic and radiologic examination of the aborted fetus confirmed the prenatal diagnosis, whereas morphological studies of the bone tissue found no hard evidence of osteogenesis imperfecta, probably due to the early stage of pregnancy and the heterogeneity of the syndrome itself. Copyright © 2005 John Wiley & Sons, Ltd.