两种Ames试验方法在槲皮素致突变试验中灵敏度的研究

目的:通过传统Ames试验与改进彷徨试验对槲皮素的致突变试验结果,比较两种试验的灵敏度.方法:Ames试验方法采用平板掺入法,选择3.2、16、80、400、2000μg/mL 5个剂量组的槲皮素在有或无代谢话化条件下处理鼠伤寒沙门氏菌株TA98和TA 100 48小时后计数回复突变菌落数;改进彷徨试验采用96孔板法,选择0.128、0.64、3.2、16、80μg/mL 5个剂量组的槲皮素在有或无代谢活化条件下处理鼠伤寒沙门氏菌株TA98和TA100 24小时后计数变色孔数.结果:Ames试验结果显示槲皮素在80-2000μg/mL回复突变菌落数明显增加并超过对照2倍并有明显剂量反应关系,Ames试验结果阳性;改进彷徨试验结果显示槲皮素在0.64-80μg/mL变色孔数明显增加(P＜0.01),并有剂量反应关系,结果为阳性;而在0.64-16μg/mL剂量下,改进彷徨试验能检测出阳性结果,而Ames试验未检测出阳性结果.结论:在较低浓度时,改进彷徨试验能检测出Ames试验检测不出的阳性结果,表明改进彷徨试验灵敏度较Ames试验高.     

Ames试验假阳性的判断方法

目的:确立一种判断Ames试验假阳性的可靠方法。方法:在Ames平皿掺入试验中发现经受试物处理的TA97和TA1535的菌落数相比溶媒对照组明显增加,为了证实其是因为受试物致突变性导致的回变菌落数增加还是由受试物毒性导致的菌落数增加,对分别经受试物和阳性对照物处理的Ames菌落进行增菌培养后接种于无组氨酸的培养基上,观察比较细菌的生长情况。结果:经受试物处理的菌株不能生长在无组氨酸的培养基中,而经阳性对照物处理的菌株则可以生长在无组氨酸的培养基上,说明经受试物处理的菌株没有发生突变。结论:此方法能可靠地验证菌株是否为突变菌株,由本研究可以发现经受试物处理的菌株没有发生突变,Ames平皿掺入试验中所观察到的菌落数增加是由于受试物毒性造成的假阳性。     

Ames试验中各类不同样品处理方法的探讨

Ａｍｅｓ试验中各类不同样品处理方法的探讨韩惠娟,查捷（杭州市卫生防疫站,杭州３１０００６）８０年代以来,世界各国对人类肿瘤和遗传病与环境污染关系的认识逐渐加深,更加重视环境污染问题。环境污染为每一个工业国家必须解决的重大问题之一。Ａｍｅｓ试验是目前国...     

蕨菜乙醇提取物的Ames试验研究

目的：研究蕨菜乙醇提取物的致突变作用,为蕨菜的开发利用提供一定依据;方法：制备蕨菜乙醇提取物,采用Ames试验方法,以50μg/皿敌克松作为诱变剂,分别添加提取物50、100、200、400、800μg/皿,统计回变菌落数;结果：受试物各剂量组回变菌落数均未超过自发回变菌落数的2倍,且无剂量-反应关系;结论：在本实验条件下,蕨菜乙醇提取物无致突变作用.     

昆明水源水和自来水水质致突变性及化学背景值：I.Ames试验和水源…

本文报道，用ＸＡＤ－２离子树脂吸附富集法制备自来水和滇池及松华坝水库源水提取物，以Ａｍｅｓ鼠伤寒沙门氏菌回复突变系统诱发致突变性，Ａｍｅｓ试验结果如下：来自滇池源水经氯化的自来水提取物，用ＴＡ９８菌株加Ｓ９或不加Ｓ９混合物，突变率〉２，结果为阳性。滇池源水提取致突变性可疑。使用化学分析法结合生物分析法评价昆明自来水和滇池及松华坝水库水中的化学微量污染物，估价在水中的微量污染物对人体健康的潜在致癌效     

Ames试验中菌落呈色计数法的探讨

本实验利用氯化三苯四氮唑(TTC)使革兰氏阴性菌显色的原理,在平板法Ames试验中,添加TTC浓度为lmg/皿时,使测试菌株(鼠伤寒沙门氏菌组氨酸缺陷型株TA97、TA98、TA100、TA102)呈为红色。试验证明TTC本身无诱变性,亦不干扰阳性物(2-AF)的诱变性。菌落呈色后便于菌落计数,并在一定程度上提高试验结果的准确性。     

Ames试验中菌落呈色计数法的探讨

本实验利用氯化三苯四氮唑(TTC)使革兰氏阴性菌显色的原理,在平板法Ames试验中,添加TTc浓度为1mg/皿时,使测试菌株(鼠伤寒沙门氏菌组氨酸缺陷型株TA97、TA98、TA100、TA102)呈为红色。试验证明TTC本身无诱变性,亦不干扰阳性物(2-AF)的诱变性。菌落呈色后便于菌落计数,并在一定程度上提高试验结果的准确性。     

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。     

昆明水源水和自来水水质致突变性及化学背景值:I.Ames试验和水源水及自来水微量有机、无机污染物化学背景值

本文报道，用XAD-2离子树脂吸附富集法制备自来水和滇池及松华坝水库源水提取物，以Ames鼠伤寒沙门氏菌回复突变系统诱发致突变性，Ames试验结果如下：来自滇池源水经氯化的自来水提取物，用TA[98]菌株加S9或不加S[9]混合物，突变率>2，结果为阳性。滇池源水提取物致突变性为可疑。使用化学分析法结合生物分析法评价昆明自来水和滇池及松华坝水库水中的化学微量污染物，估价在水中的微量污染物对人体健康的潜在致癌效应是有意义的。     

昆明水源水和自来水水质致突变性及化学背景值1．Ames试验和水源水及自来水微量有机、无机污染物化学背景值

本文报道：用ＸＡＤ－２离子树脂吸附富集法制备自来水和滇池及松华坝水库源水提取物,以Ａｍｅｓ鼠伤寒沙门氏菌回复突变系统诱发致突变性。Ａｍｅｓ试验结果如下：来自滇池源水经氯化的自来水提取物,用ＴＡ９８菌株加Ｓ９或不加Ｓ９混合物,突变率＞２,结果为阳性。滇池源水提取物致突变性为可疑。使用化学分析法结合生物分析法评价昆明自来水和滇池及松华坝水库水中的化学微量污染物,估价在水中的微量污染物对人体健康的潜在致癌效应是有意义的。     

Using Short-Term Mutagenicity Tests for the Evaluation of Genotoxicity of Contaminated Soils

The study is aimed at evaluating the genotoxicity of contaminated soils using two bacterial mutagenicity assays — the Ames test and the SOS Chromotest. Initially, attention is directed at the method of extraction of soil samples by organic solvents. The detection of mutagenicity was dependent on the type of organic solvent. Dichloromethane (DCM) proved to be a better extraction agent than acetone because it is more effective for extracting mutagenic compounds. In the second part of our study, the possibilities of using bacterial mutagenicity assays for monitoring the course and effectiveness of bio-remediation of contaminated soils were ascertained. The results of an evaluation of the genotoxicity of a residue of polycyclic aromatic hydrocarbons (PAHs) that decompose with difficulty showed that a decrease in the concentration of detectable components need not always correspond to a total decrease of the mutagenic effect. Contaminants inducing SOS repair were degraded relatively quickly in soils, whereas it was found that mutagens inducing frameshift mutations persisted in samples.     

Ames实验及彗星实验检测辅酶NADH的抗突变作用

采用Ames实验及单细胞凝胶电泳（SCGE,彗星实验）,对还原型辅酶NADH进行抗突变研究。NADH中、高剂量组在加或不加S9的情况下,均能不同程度地抑制由致突变物引起的TA98、TA100回变菌落数的增加,降低SCGE拖尾细胞率。表明还原型辅酶NADH具有一定的抗突变作用。     

Mutagenicity of blue rayon extracts of human bile in the Ames test

The mutagenicity of human bile was examined in the Ames Salmonella/microsome assay. Bile samples were obtained from the gallbladders resected from patients with cholelithiasis, choledocholithiasis, gallbladder cancer, extrahepatic bile duct cancer and other disease. For extraction of mutagenic components, the bile samples were treated with blue rayon and the adsorbed materials were assayed with Salmonella typhimurium TA98 in the presence of S9 mix. Twenty-four bile samples were tested and positive mutagenic activity was found in 14 samples. A 200-μl bile equivalent material gave 6.3 times as many revertant colonies as the solvent control. With several samples that had undergone two cycles of blue rayon extraction, clear dose-response relationships in mutagenicity were demonstrated.     

Effect of different exposed lights on quercetin and quercetin glucoside content in onion (Allium cepa L.)

Quercetin and quercetin glucosides are the major flavonols present in onion (Allium cepa L.) and are predominantly present as quercetin, quercetin-3,4′-diglucoside and quercetin-4′-glucoside. Effect of different light wavelengths on onion after harvest and storage, with fluorescent, blue, red and ultra violet light influenced the quercetin and quercetin glucosides profile. In a peeled onion, all the light treatments elevated quercetin content in bulb. Among them, particularly fluorescent light effect was more eminent which stimulates the maximum synthesis of quercetin in onion. In case of whole onion bulb, skin and pulp showed different responses to light treatment, respectively. The pulp had the highest quercetin glucosides under blue light, whereas the lowest under fluorescent light. Onion skin showed nearly opposite pattern as compared to the pulp. In particular, light treatment proved to be a better way to increase the level of quercetin content in onions which might be utilized for industrial production of bioactive compounds from onion and onion waste products.     

Mutagenicity assessment of Salacia chinensis by bacterial reverse mutation assay using histidine dependent Salmonella typhimurium tester strains

Background and objectiveGenotoxicity analysis is one of the most important non-clinical environmental safety investigations required for pharmaceutical and agrochemical product registration. Any medicinal product must undergo a risk evaluation to determine its mutagenicity and carcinogenicity.Materials and methodsThe Ames test is a commonly used in vitro test for determining a test chemical's mutagenic activity. Histidine-dependent Salmonella typhimurium strains with a defective gene that causes the bacteria to synthesis the necessary amino acid histidine for life were tested for mutagenic potential. In order to reveal pro-mutagens and mutagens, the mutagenic potential of both plate integration and pre-incubation techniques was examined in the presence and absence of metabolizing system. Salacia chinensis has been widely used in ayurveda to treat various ailments. However, the information of mutagenicity of Salacia chinensis is scarce as per available literature.ResultsThe mutagenicity of a Salacia chinensis root extract was investigated utilizing the Ames assay with plate incorporation and pre-incubation protocols using the appropriate Salmonella typhimurium tester strains: TA98, TA100, TA1537, TA1535, and TA102 in the presence and absence of S9. The concentrations used were 0.3123, 0.625, 1.25, 2.5 and 5 mg/plate. The extract of Salacia chinensis root did not show any mutagenic effect in any of the Salmonella typhimurium strains at the concentrations tested in the absence or presence of metabolic activation.ConclusionThe root of Salacia chinensis was hence confirmed to be non-mutagenic and at least according to the results of this genotoxicity evaluation can be regarded as being safe for human use.     

Evaluation of the antimutagenic potential of chitosan oligosaccharide: Rec, Ames and Umu tests

Two types of chitosan oligosaccharides (COS), COS I (1-kDa < MW < 3-kDa) and COS II (3-kDa < MW < 5-kDa), were tested for antimutagenic activities against chemical mutagens using Umu gene expression, Ames, and Bacillus subtilis Rec mutagenicity tests. At the highest chitosan oligosaccharide dose (1 mg) tested, mutagenic activity of indirect-acting mutagen was inhibited by 50% in the Umu gene expression system and in the Ames test. Chitosan oligosaccharide (0.01, 0.1 and 1 mg) also suppressed 4-nitroquinoline-N-oxide (NQO)-induced mutagenicity in the B. subtilis Rec^– assay.     

两种体外细胞毒性检测方法的比较研究

目的比较两种常用的细胞毒性检测方法在医疗器械生物学评价中的相关性。方法分别采用MTT比色法和细胞增殖度法,在37℃条件下,将五种医疗器械／生物材料的浸提液分别与小鼠成纤维细胞（L-929）接触2天和2,4,7天,比较材料对细胞的毒性影响。结果5种不同的材料浸提液分别表现出不同程度的细胞毒性反应（0～2级）。将MTT比色法与细胞增殖度法（2天）的实验数据进行相关性分析,显示两者之间具有良好的相关性（R=0．977）。结论MTT比色法由于其检测所需的细胞量相对较少,试验步骤相对简便、检测周期短,因此具有一定的优越性,是个值得推荐的细胞毒性检测方法。