双核微核法检测煤尘遗传毒性的研究

用双核微量核法对三种煤尘亚硝化前后的致突变性进行检测，结果未经亚硝化时，三种煤尘均呈现致突变作用；而在酸性条件下被亚硝化后，二种烟煤表现出了致突变性能。试验提示，在检测煤尘致突变作用中，体外细胞双核微核法的灵敏度高于传统微核法。     

煤尘提取物的遗传毒性研究

本研究系采集山西省８个大矿务局所属的１０个煤矿，井下掘进工作面煤样１６份，包括７种煤、即烟煤、无烟煤，弱粘结煤，肥煤，瘦煤、焦煤、气煤，每一份煤将经提取，分成丙份；一份进行亚硝化，另一份为非亚硝化煤样，分别进行Ａｍｅｓ试验，ＳＯＳ显色试验，双微核试验，大鼠骨骼细胞染色体为分骅结果表：１６份煤样提取物经亚硝化后，其中有１０种Ａｍｅｓ试验。ＳＯＳ显色试验均为阳性，从１０种阳性煤尘中，选１至３种进行染色     

大蒜对N—亚硝酰胺致突变作用的影响

大蒜摄入量与患胃癌的风险呈负相关,可能具有防胃癌作用。我们使用Ames试验探讨了大蒜对人胃癌可疑病因N-亚硝酰胺致突变性的影响。结果表明大蒜球茎匀浆在无毒性的剂量(5-15mg/皿)范围内有阻断100nmol/皿ENNG (N-ethyl-N′-nitro-N-nitrosoguanidine)、150nmol/皿的MNU(N-methyl-N-nitrosourea)和200μl/皿亚硝化鱼露直接致TA100回复突变作用,但在平板掺入试验中增强5nmol/皿MNNG(N-methyl-N′-nitro-N-nitrosoguanidine)致突变强度,在预培养试验中则抑制它的致突变作用。大蒜的有效成分大蒜素(0.1-0.3μmol/皿)能明显地阻断TA100的致突变性。以上结果证明大蒜及其有效成分有抗N-亚硝酰胺致突变的作用。文中对大蒜在特殊条件下促进MNNG致突变的机理进行了讨论。     

指状青霉提取物诱发E.coli ND-160及K12 infA基因突变

背景与目的:研究指状青霉(Penicillium digitatum)提取物对大肠杆菌菌株的致突变性.材料与方法:采用E.coliND-160菌株回复突变试验、K12infA基因突变试验及其突变序列分析.结果:指状青霉提取物:①可明显地诱导ND-160菌株回复突变;②对K12菌株可诱发其infA基因DNA序列中5个碱基位点突变,且其中1个位点的突变还可导致编码相应氨基酸的改变(Lys→Val).结论:指状青霉对大肠杆菌基因有明显的致突变性.     

化妆品的致突变和抗突变同步快速试验分析

目的与方法: 为了快速筛选有致突变性的化妆品,采用大肠杆菌溶源性菌GY5027和对噬菌体敏感的指示菌GY4015,对29种化妆品进行致突变和抗突变同步快速试验.同时观察了急性经口试验、急性眼睛刺激试验和急性或多次皮肤刺激试验.结果:在加和不加大鼠肝脏微粒体酶(S-9)条件下,全部样品无抗突变阳性;4种样品呈现致突变阳性,其中2种至少1项急性试验阳性.经SPSS软件作等级相关分析表明,同步试验与急性试验结果相关显著(r-s＝0.392,P=0.036).结论:部分化妆品确实存在致突变性;采用致突变和抗突变同步试验可快速、大量筛选有致突变性的化妆品;急性试验阳性化妆品致突变性也较高.     

鲁奇低温煤焦油的致突变性及致突变性组份的鉴定

本文将致突变性研究与化学分级和化学组份鉴定相结合,研究讨论了鲁奇低温煤焦油样品的致突变性及致突变性分布,讨论了样品的致突变性来源,并对显著致突变性级分的化学组份进行了分析鉴定。 煤焦油样品经酸碱提取分离为酸性、碱性和中性组分,中性组分和碱性组分再经硅胶柱制备色谱分别分为N_1—N_6六个级分和B_1-B_3三个级分。Ames试验表明,对样品     

育发剂致突变性2种试验方法的比较

背景与目的:探讨检测育发剂致突变性的适宜的方法.材料与方法:运用Ames试验、小鼠淋巴瘤细胞试验(MLA)对3种育发剂的致突变性进行研究.结果:28种育发剂中有85.72%的样品对组氨酸缺陷型鼠伤寒沙门氏菌均有程度不同的抑菌或杀菌作用,选取的3种育发剂对组氨酸缺陷型鼠伤寒沙门氏菌均有较强的抑菌杀菌作用,在试验浓度下均未呈现致突变性;MLA试验结果显示,1号样品和3号样品育发剂在测试浓度下未呈现致突变性;2号样品育发剂随浓度增大,L5178Y细胞TK位点的突变频率有升高的趋势,其中8 μl/ml、40 μl/ml和200 μl/ml剂量组的突变率,与对照组相比差异有统计学意义(P＜0.05).结论:小鼠淋巴瘤细胞试验(MLA)可做为毒性较大育发剂的遗传毒性筛检的补充试验.     

胃癌高发区鱼露中N-亚硝基化合物前体的分析

对胃癌高发区福建长乐县49份鱼露样品的N-亚硝基化合物(NOC)前体进行分析,从中检出17种游离氨基酸,总含量为630μmol/ml。其中谷氨酸、丙氨酸、亮氨酸、缬氨酸、赖氨酸和甘氨酸的含量占70％。另外还检出了肌酸(2.67μmol/ml)、肌酐(3.01μmol/ml)和腐胺(0.014μmol/ml)。在亚硝化后样品中NOC总量高达2.95μmol/ml,其乙酸乙酯萃取物中还检出了0.06μmol/ml的N-亚硝酰胺。结果说明鱼露中含有可亚硝化胺类前体,长期食用可能与当地胃癌高发有关。     

北豆根提取物抗突变和致突变的实验研究

目的:分析中药北豆根不同提取物的抗突变和致突变作用,为抗肿瘤新药开发、研制提供依据。方法:用三步法初步分离、纯化北豆根提取物,得到北豆根水提液(aqueousextractofrhizomamenispermi,RMAE)、醇提液的初步纯化产物蝙蝠葛酚性生物碱(phenolicalka-loidsofmenispermumdauricum,PAMD)和北豆根多糖成分(rhizomamenispermipolysaccha-ride,RMP)。采用细菌培养技术进行抗突变致突变直接及间接同步快速实验,以检测不同北豆根提取物的抗突变和致突变活性。结果:北豆根不同提取物RMAE、PAMD和RMP的直接和间接致突变实验结果均为阴性。而RMP直接和间接抗突变结果为阳性,并且具有浓度依赖性。RMAE、PAMD直接和间接抗突变实验结果均为阴性。结论:北豆根各提取物均无致突变毒性,而RMP具有直接和间接的抗突变活性。     

鱼露致中国仓鼠卵巢细胞HGPRT位点突变作用

背景与目的:研究鱼露及亚硝化鱼露对中国仓鼠卵巢(CHO)细胞HGPRT位点突变的影响.材料与方法:分别将鱼露和亚硝化鱼露分成4个不同剂量处理组:5 μl/ml、2.5μl/ml、1.25 μl/ml、0.625 μl/ml,另设阳性对照组(EMS:0.75 μg/ml,不需代谢活化;MCA:4 μg/ml,需代谢活化)和溶剂对照组(三蒸水),应用CHO/HGPRT基因突变试验,采用琼脂平皿法,检测鱼露和亚硝化鱼露对CHO细胞的毒性及突变体频率,评价鱼露及亚硝化鱼露引起突变的可能性.结果:经S9系统活化和未经S9系统活化的所有处理组突变体频率差异均有统计学意义(X2S9-=41.115;FS9 =19.528;P均＜0.01);亚硝化鱼露及经S9系统代谢活化后的鱼露组处理突变体频率均显著高于溶剂对照组(P＜0.05或P＜0.01),且存在剂量-效应关系(S9-:r 亚硝化鱼露=0.986,P＜0.05;S9 :r鱼露=0.950,P=0.05;r亚硝化鱼露=0.997,P＜0.01);而未经S9系统活化的鱼露处理组与溶剂对照组间差异均无统计学意义(P＞0.05).结论:鱼露经亚硝化后对CHO/HGPRT位点有致突变作用,经S9系统活化后可能也有此作用.     

Mutagenic activity in the stomach and small intestine of rats after oral administration of nitrosated beef extract

The products formed by the reaction of beef extract with nitrite were assayed in the Salmonella/microsome mutagenicity test. In strain TA1538, TA98 and TA100 a direct-acting mutagenic response was observed. The presence of liver-microsome preparation resulted in decreased mutagenicity. To study the absorption, distribution and excretion of mutagenic substances in nitrosated beef extract, the test material was given perorally to rats. Investigations of the stomach, bile fluid, urine, small intestine and blood samples were carried out, and mutagenicity was found in the contents of stomach and small intestine. It is supposed that unlike beef extract itself, its nitroso product is not excreted in the bile but passes directly from the stomach and small intestine.     

Mutagenicity of emission and immission samples around industrial areas

Urban air particulates (suspended particles and settling dusts), as well as dusts emitted by a S?derberg aluminium production plant and a coal-burning power plant, in the industrial town of Ajka were analysed for polycyclic aromatic hydrocarbon (PAH) content (liquid chromatography) and mutagenicity (Salmonella microsome test). The same parameters for air particulates from Pápa (a town of similar size without much heavy industry) were analysed and compared to those from Ajka. The dust content, PAH concentration and the mutagenic potency of the air in Ajka were higher than in Pápa. Mutagenicity of airborne particulates showed a clear seasonality with a winter maximum and a summer minimum in both towns. The mutagenic potency of air correlated well with the benzo[a]pyrene (BP) and PAH content in Ajka but not in Pápa. The amounts of extractable organic material and mutagenic potency, as calculated for unit quantity of airborne particulate matter, were higher in the Pápa samples. Similar differences between the two towns were observed in the case of deposited dust. As regards the emission dusts, the aluminium plant emissions are responsible for much more of the mutagenicity of the urban air than the power plant emission, which is the main component of air dust pollution in Ajka.     

上海市大气悬浮颗粒物有机提取物的致突变性研究

本研究采用Ａｍｅｓ试验研究上海市大气浮颗粒物的致突变性。结果表明，在没有体外活化主情况下可引起ＴＡ９８菌株回复突变数增加，加入活化系统可降低致突变性。冬季样品的致突变性大于夏季样品，比较不同采样点的致突变性、Ｋ、Ｈ、Ｅ等三个点样品的致突变性最强，当考虑到浓度后，Ｈ、Ｅ、Ｇ三点致突变性最强，Ｋ点受浓度影响最大。     

Mutagenicity and carcinogenicity of fish sauce from a county with the high risk for gastric cancer in china

The mutagenicity and carcinogenicity of fish sauce (FS) sample from Changle County, a high gastric cancer mortality (113.20/10⁵) are, were investigated with the biologic short-term tests and laboratory animal experiment. The results showed that the extract of FS was markedly direct mutagenic towardS. typhimurium TA100, induced high sister chromatid exchanges (SCE) and micronucleus (MN) in V79 cells after nitrosation with sodium nitrite. But the non-nitrosated FS did not. The nitrosated fish sauce (NFS) also induced SOS inE. coli PQ37 and alkylation of calfthymus DNA. The potency of NFS to induce unscheduled DNA synthesis (UDS) in human normal gastric mucosal cells was increased about fivefold compared with FS. When the NFS extract was given to newborn rats by gavage, dysplasia and adenocarcinoma were induced in the glandular stomach in the 4th and 16th experimental week, respectively. N-nitrosamides were also found in NFS, which may account for the mutagenicity and carcinogenicity of NFS. It is indicated that FS, a traditional daily eaten seasoning, may contribute to the causes of the high gastric cancer mortality for the local residents.     

Biological monitoring of human exposure to coal tar. Urinary mutagenicity assays and analytical determination of polycyclic aromatic hydrocarbon metabolites in urine

The mutagenicity of urine extracts from anode plant workers exposed to coal tar pitch volatiles and non-smoking psoriatic patients treated with coal tar applications and UV light (Goeckermann regimen), was determined by the plate incorporation assay and the fluctuation test employing Salmonella typhimurium strain TA98 in the presence of rat liver post-mitochondrial fractions and deconjugating enzymes. The levels of total polycyclic aromatic hydrocarbons (PAHs) and of a marker metabolite of pyrene (1-hydroxypyrene) were determined in the urine of the same subjects. Both the occupational and in particular the therapeutic exposure to coal tar resulted in clear increases in urinary levels of PAH metabolites as compared to unexposed subjects. The level of 1-hydroxypyrene in the urine samples was comparable to or even greater than the corresponding level of total PAHs, indicating a poor recovery of PAH metabolites for this method. Following treatment with coal tar, most of the psoriatic patients excreted clearly increased levels of mutagens in their urine, while non-smoking anode plant workers showed no increase in urinary mutagenicity. The minimum levels of PAH metabolites corresponding to a significant increase in urinary mutagenicity varied from sample to sample, presumably depending on interfering factors present in different amounts in the extracts. Nonetheless the urine samples which were clearly mutagenic presented elevated levels of PAH metabolites, suggesting that the mutagenicity assays lack sufficient sensitivity to allow their application in the biological monitoring of most occupational exposures to coal tar.     

Role of nitrosamides in the high risk for gastric cancer in China.

Gastric cancer is the leading cause of death from cancer in China. Samples of fish sauce, a traditional seasoning, were collected in the high-risk area for gastric cancer in the Fuzhou area, Fujian Province. When fish sauce samples were nitrosated at pH 2.0, direct mutagenicity and high contents of N-nitrosamide were detected (30.9-78.0 microM); the N-nitrosamide content of three samples of fish sauce made in Guangdong and purchased from a market outside Fujian were low (2.1-6.0 microns). When the nitrosated fish sauce extract was given to newborn rats by gavage, dysplasia and adenocarcinoma were induced in the glandular stomach in the 4th and 16th experimental week, respectively. N-Nitrosamides were also found in fasting gastric juice from patients with chronic gastritis in the high-risk area of Putian. The mean concentration of total N-nitrosamides in the extracts correlated with the severity of gastritis in the stomach. These findings indicate that N-nitrosamides may play an important role in causing gastric cancer in China.     

Carcinogenic components of smokeless tobacco and tobacco-free cigarettes

The investigation deals with an assessment of carcinogenicity and mutagenicity of samples of smokeless tobacco now on the Russian market as well as ash from alternative cigarettes made of aromatic herbs. Our data showed that the levels of polycyclic aromatic hydrocarbons, volatile and tobacco-specific N-nitrosoamines complied with the standards in the producer-countries. Smokeless tobacco extracts failed to show (Ames) any mutagenic effects such as the "read-out frame shift" or "base-pair replacement" patterns. No tobacco-specific N-nitrosoamines were identified in herbal cigarettes. However, polycyclic aromatic hydrocarbons and volatile N-nitrosoamines content appeared to be identical to that of tobacco. Herbal cigarette smoke extracts mutagenicity induced by side-effects of carcinogenic substances was of similar magnitude as well.     

Mutagen formation during the cooking of fish

Compounds mutagenic toward Salmonella typhimurium strains sensitive to frameshift mutation (1537, 1538 and TA98) were formed when fish flesh was fried at 190°C. Four species of marine fish commonly consumed in the United States were cooked in an electric skillet and broiled beneath the elements of an electric oven. Organic extracts of the fish were tested in the Salmonella mutagenic assay using strains 1535, 1537, 1538, TA98 and TA100. Basic organic extracts of fried but not raw or broiled samples exhibited significant mutagenicity with metabolic activation. Mutagenic activity ratios ranging from 3.3 to 15.7 for the extract from 20 g of fish were observed. The mutagenicity produced during the frying of fish was dependent on time. Frying times of less than 6 min produced no mutagenic activity, while at 6 min or greater substantial mutagenicity was generated.     

Mutagenic activity and polycydic aromatic hydrocarbon levels in urine of workers exposed to coal tar pitch volatiles in an anode plant

The mutagenicity of urinary extracts and the excretion of PAHfrom workers occupationally exposed to coal tar pitch volatilesin an anode plant were analyzed. Mutagenicity of the urinaryextracts was measured by means of the plate test using S.typhimuriumstrain TA 98. After concentration, hydrolysis and reductionof the urine samples, PAH levels were measured by high resolutiongas chromatography/mass spectrometry. No significant differencewas found in the mutagenicity of the urinary extracts of non-smokersoccupationally exposed to PAH as compared with the controls.Low PAH concentrations were found in the urine of the exposedsubjects, which lends further support to the negative resultsobtained with the Ames' test. The increase of urinary PAH excretion,in relation to occupational exposure, was mainly due to theless mutagenic, low molecular weight compounds.