化工厂生产废水致突变性研究

本文就合肥某化工厂生产用水、氯乙烯工段生产废水、化工厂总排污渠污水、南淝河化工厂下游水、化工厂深井水及阴性对照双蒸水进行了有机浓集物的致突变性研究,Ａｍｅｓ试验结果表明：南淝河水在化工厂用于生产之间已受到致突变性污染,ＴＡ９８＋Ｓ９和ＴＡ９８－Ｓ９均出现阳性,化工厂总排污渠污水ＴＡ９８＋Ｓ９呈阳性且有增强趋势,氯乙烯工段生产废水和南淝河化工厂下游水ＴＡ９８＋Ｓ９也呈阳性。深井水和双蒸馏水ＴＡ９８＋     

化学物质致突变性的检测方法研究进展

化学物质的致突变性评价对于预防人类疾病和控制环境污染具有非常重要的意义.为了检测化学物质的致突变性,对化学物质的致突变性评价中常用的一些主要方法及其应用的效果做了概述,并对当前致突变性检测的方法学中存在的问题以及发展趋势进行了简要的讨论.     

土壤环境中除草剂甲磺隆降解的研究Ⅰ.土壤性质的影响

采用方差分析,研究了各土壤中不同形态甲磺隆残留量的差异程度;通过主因子分析,选出5个主因子,它们代表了整体信息量的90.4%;回归分析后建立了土壤性质和甲磺隆残留间的多元回归方程;经偏相关分析和通径分析得出,土壤pH值和微生物活性是甲磺隆降解的主要影响因素。     

氯嘧磺隆降解菌的分离鉴定及其降解特性

利用富集培养技术从长期施用氯嘧磺隆的土壤中分离得到1株能够降解氯嘧磺隆的细菌L-7。通过生理生化特性和16SrRNA序列分析,初步鉴定L-7为寡养单胞菌属(Stenotrophomonas sp.)。并分析了氯嘧磺隆的初始浓度、接种量、温度和pH值对L-7菌株降解氯嘧磺隆效果的影响,确定了最佳降解条件。结果表明,该菌在氯嘧磺隆浓度为100mg/L、接种量为5%、pH4.0、温度30°C条件下,接种5d后对氯嘧磺隆的降解效率达到80%以上。     

氯嘧磺隆对土壤微生物群落结构的影响

采用磷脂脂肪酸(PLFA)法研究了黑龙江省苇河地区不同氯嘧磺隆施药历史下土壤微生物群落结构的差异, 并测定了土壤中氯嘧磺隆的残留量.结果表明：不同施药历史下氯嘧磺隆在土壤中的残留量均很低;随着施用氯嘧磺隆年限的增加,土壤微生物的PLFA总量减少, 革兰氏阴性菌/革兰氏阳性菌（GN/GP）和真菌/细菌比降低,土壤微生物的压力指数增加.主成分分析表明,氯嘧磺隆显著改变了大豆田土壤微生物群落结构.     

甲磺隆对微囊藻生长和光合系统的影响

研究选取了水体常见蓝藻优势种类——铜绿微囊藻(Microcystis aeruginosa PCC7806)作为研究对象, 了解磺酰脲类除草剂甲磺隆(Metsulfuron-methyl)对铜绿微囊藻生长和光合系统的影响。研究表明, 当甲磺隆浓度大于80 mg/L时, 对铜绿微囊藻的生长具有显著抑制。通过回归分析和Probit分析, 甲磺隆对铜绿微囊藻生长的EC₅₀为81.998 mg/L。细胞色素研究结果显示, 实验第6天, 各浓度处理下单位细胞内Chl.a和类胡萝卜素含量均低于对照组, 且当甲磺隆浓度为80 mg/L时, 单位细胞内类胡萝卜素含量显著低于对照组。快速叶绿素荧光诱导动力学变化结果分析显示, 实验第6天甲磺隆胁迫下单位反应中心捕获的用于电子传递的能量(ET₀/RC)及单位反应中心用于电子传递的量子产额(φE₀)受到显著抑制, 综合细胞色素变化结果显示, 甲磺隆能显著抑制光合系统反应中心电子受体侧电子性能。综上所述, 甲磺隆可能作用于光合系统反应中心电子受体侧, 从而对铜绿微囊藻光合系统造成影响。     

氯嘧磺隆降解菌株LW-3的分离及生物学特性研究

从长期受氯嘧磺隆污染的土壤中分离到一株氯嘧磺隆高效降解菌株,命名为LW-3,菌株LW-3可以氯嘧磺隆为唯一氮源生长,接种量为2%时,50 mg/L氯嘧磺隆经过7 d,降解率达70%～80%.生理生化实验和16S rDNA序列同源性分析,将菌株LW-3归属于假单胞茵属(Pseudomonas sp.);菌株的适宜降解条件为;温度30℃～35℃,pH 6.5～7.2,pH对菌株LW-3降解氯嘧磺隆有明显地影响.     

一株氯嘧磺隆降解菌分离鉴定及降解条件优化

为解决氯嘧磺隆残留对土壤、水体污染及后茬敏感作物药害问题,为污染土壤微生物修复提供降解菌种资源,文中采用富集培养、逐级驯化等方法,从氯嘧磺隆污染土壤中分离到1株高效氯嘧磺隆降解菌T9DB-01,经形态特征、生理生化及16S rDNA序列分析,鉴定为假单胞菌Pseudomonas sp.。采用单因素实验探究温度、pH值、底物浓度、装液量和接种量对菌株T9DB-01降解氯嘧磺隆的影响,采用正交试验及验证,优化菌株T9DB-01对氯嘧磺隆降解条件。结果表明,在30℃,pH 8.0,底物浓度200 mg/L,装液量100 mL/250 mL,接种量4%的条件下,5 d后降解率达到93.7%。该降解菌株对氯嘧磺隆污染土壤原位生物修复具有一定的应用潜力。     

抑菌生的致突变性试验

本文应用Ames试验、微核试验,对中国人民解放军224医院及沈阳军区军事医学研究所研制的具有抗感染作用的枯草杆菌BS_(224)生态制剂即抑菌生进行了致突变性检测。结果表明:BS_(224)生态制剂不能使鼠伤寒沙门氏菌株发生回复突变,不引起小鼠骨髓嗜多染红细胞微核率升高,初步认为BS_(224)生态制剂无突变性,推测无致癌性。     

抚仙湖有机污染物化学背景值及人淋巴细胞体外致突变性评定

用ＸＡＤ－２树脂提取抚仙湖７个采样点的有机物质水样提取物,用气相色谱／质谱（ＧＣ／ＭＳ）进行分析,在每种水样品中发现有上百种有机污染物,提取物用培养的人淋巴细胞系姐妹染色单体交换（ＳＣＥ）试验作致突变潜力检查,结果显示,仅入湖口水样在高浓度组（０．０６２５Ｌ／ｍＬ）诱发ＳＣＥ明显增加。     

眼镜蛇神经毒素的急性毒性实验研究

目的　研究眼镜蛇神经毒素 （ Ｃｏｂｒａ ｎｅｕｒｏｔｏｘｉｎ, Ｎ Ｔ） 的急性毒性和蓄积毒性。方法　测 Ｎ Ｔ 对小鼠的 Ｌ Ｄ５０ ; 对大鼠、狗的１ 次性最小中毒剂量和最大安全剂量; 计算 Ｎ Ｔ 在小鼠、狗体内的２４ｈ 蓄积率。结果　 Ｎ Ｔ 经静注、肌注、腹腔、皮下 ４ 种途径给药对小鼠的 Ｌ Ｄ５０ 分别是 （１９５±９５） μｇ／ｋｇ、（１５６±８５） μｇ／ｋｇ、（１５１±１９） μｇ／ｋｇ、（１８４±８５） μｇ／ｋｇ, 对小鼠的最小致死剂量为９７５μｇ／ｋｇ。 Ｎ Ｔ 对大鼠、狗的１ 次性中毒剂量分别为５４μｇ／ｋｇ 和３４μｇ／ｋｇ。对小鼠、大鼠和狗的安全剂量分别为８１５μｇ／ｋｇ、４２μｇ／ｋｇ和３０μｇ／ｋｇ, 分别约为人临床用剂量 （７０μｇ／５０ｋｇ·ｄ－ １ ） 的５８２、３０ 和２１ 倍。 Ｎ Ｔ 在小鼠、狗体内的２４ｈ蓄积率分别为 ５７％ 和３０％ 以上。结论　 Ｎ Ｔ 在使动物中毒的剂量下有广泛的安全范围; Ｎ Ｔ 在动物体内存在弱蓄积毒性。     

Studies of genotoxicity and mutagenicity of nitroimidazoles: demystifying this critical relationship with the nitro group

Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potential induction of genotoxicity (comet assay) and mutagenicity (Salmonella/Microsome assay) and the correlations of these effects with their trypanocidal effect and with megazol were investigated. The compounds were designed to analyse the role played by the position of the nitro group in the imidazole nucleus (C-4 or C-5) and the presence of oxidisable groups at N-1 as an anion receptor group and the role of a methyl group at C-2. Nitroimidazoles bearing NO2 at C-4 and CH3 at C-2 were not genotoxic compared to those bearing NO₂ at C-5. However, when there was a CH3 at C-2, the position of the NO2 group had no influence on the genotoxic activity. Fluorinated compounds exhibited higher genotoxicity regardless of the presence of CH3 at C-2 or NO2 at C-4 or C-5. However, in compounds 11 (2-CH3; 4-NO2; N-CH2OHCH2Cl) and 12 (2-CH3; 4-NO2; N-CH2OHCH2F), the fluorine atom had no influence on genotoxicity. This study contributes to the future search for new and safer prototypes and provide.     

Evidence for the antimutagenicity and the mutagenicity of selenium

Evidence is summarized for the antimutagenicity as well as the mutagenicity of selenium. In general, antimutagenicity predominates at physiological levels, while mutagenicity occurs at 3 to 1000 times normal physiological levels.     

合成芋螺多肽SO3实验动物毒性及依赖性研究

通过对中国南海线纹芋螺毒素的基因克隆并经多肽化学合成,得到了一种含有25个氨基酸残基、3对二硫键的芋螺多肽SO3,并用电生理方法确定其属于N型钙离子通道抑制剂。金鱼采用脊背注射给予4μl不同浓度的药物来观察毒性反应,小鼠按2.5、5、12.5、15、25、62.5、125mg/kg的剂量侧脑室给予10μl药物来测定LD50。大鼠采用脊髓鞘内套管重复给药,剂量为2.0μg/kg,给药体积10μl,用烫尾法及压尾法测定其痛阈反应,观察连续给药15d时大鼠对SO3的药物依赖性。结果表明,当药物量分别为0.5、1.0、3.0、8.5μg时,MⅦA对金鱼的致死率分别为60％、80％、100％和100％,而SO3的致死率均为零。小鼠SO3的LD50为13.5mg/kg。经大鼠15d连续给药,未发现大鼠对SO3有药物依赖性,与进入Ⅲ期临床的无致瘾镇痛剂MⅦA相比,SO3同样没有药物依赖性,且副作用低。     

细菌胞外多糖提取优化及毒性试验研究

本文优化了提取Rhizobium sp.N613胞外多糖(REPS)的工艺条件,以发酵液pH值、乙醇浓度以及醇沉时间为因子,采用响应面法试验获得了REPS的最佳提取条件,即pH 5.9,乙醇浓度74%,醇沉时间16.5h。在该条件下,胞外多糖提取率为9.28±0.06 g·L -1,其纯度达97%,收率达93.6%。此外,还进行了REPS的特性粘度、急性毒性测试和蓄积毒性实验,结果表明该多糖具有粘度高、无毒性的特点,在食品医药领域有着广泛的应用前景。     

Use of Salmonella typhimurium TA 98, YG 1024 and YG 1021 and deconjugating enzymes for evaluating the mutagenicity from smokers'' urine

Four smokers were chosen for their different smoking habits, and their declared cigarette consumption confirmed by urinary measurement of nicotine and its metabolites. The promutagenicity of their urine was evaluated by the Ames test, modified according to Kado et al. (Mutation Res., 31 (1983) 25–32) after extraction on XAD2 Amberlite resin. The different Salmonella typhimurium strains TA 98, YG 1021 and YG 1024 were compared to determine the presence of amino aromatic compounds in the urine of smokers of blond and black tobacco. The strain YG 1024 shows higher mutagenicity than TA 98 for extracts from the smoker's urine and more particularly from black tobacco smokers. In addition, the pretreatment of urine by external enzymatic systems (β-glucuronidase or arylsulfatase) reveals the presence in the urine of glucurono- and sulfoconjugated forms of promutagens, including amino aromatic compounds.     

Predicting carcinogenicity of petroleum distillation fractions using a modified Salmonella mutagenicity assay

The Ames Salmonella/microsomal activation mutagenesis assay has been modified to improve sensitivity and reproducibility to complex mixtures derived from the refining and processing of petroleum. Oil samples were dissolved in cyclohexane and subsequently extracted with dimethyl sulfoxide to produce aqueous compatible solutions which readily interact with tester bacteria. Also, the liver homogenate (S-9) and NADP cofactor concentrations were increased and hamster rather than rat liver S-9 was used. The initial slope of the dose response curve relating mutagenicity (revertants per plate) to the dose of extract added was used as an index of mutagenic activity, this slope was obtained through a computerized curve fitting procedure. The modified assay was used to rank 18 oil samples for mutagenic activity, this ranking correlates highly (r = 0.92) with potency rankings of the same samples previously determined from dermal carcinogenicity bioassays. Sensitivity and reproducibility of the assay are sufficient to permit routine use for detecting potential carcinogenic activity of individual refinery streams and blends which contain components boiling above 500°F.Abbreviations API American Petroleum Institute - B[a]P benzo[a]pyrene - DMSO dimethyl sulfoxide - NADP nicotinamide adenine dinucleotide phosphate - PAH polycyclic aromatic hydrocarbon - S-9 microsomal fraction from rat liver     

Studies on the role of iron in the reversal of vanadium toxicity in chicks

The interaction of dietary iron levels on vanadium toxicity was studied in chicks. Dietary iron levels ranged from a deficiency, ca. 10 ppm, to an adequacy, 100 ppm supplemental iron. to an excess, 1000 ppm supplemental iron. Vanadium was fed at 10, 20, and 40 ppm. Vanadium toxicity as measured by chick growth was more severe in the iron-deficient animals than in those receiving supplemental iron. The increase in degree of toxicity in the iron-deficient animals was accompanied by an increase in the liver vanadium, both total and concentration. The addition, of vanadium to the diet did not influence the iron concentration of the liver or kidney. Radioisotope, studies with⁴⁸V revealed that the absorption of vanadium was not influenced by the iron concentration of the diet, but that the iron-deficient animals retained more vanadium in the blood and liver and less in the bone than did the iron supplemented animals. It is proposed that the degree of iron saturation of transferrin and ferritin to which vanadium can bind is a possible explanation for the results obtained. Paper No. 10687 of the Journal Series of the NC Agricultural Research Service, Raleigh, NC 27695-7601. The use of trade names implies neither endorsement of the products named nor criticism of similar products not mentioned by the NCARS.