某地区饮用水及水源水致突变性研究

目的 探讨某地区丰水期和枯水期的饮用水及水源水的致突变性。方法 采用AMES试验。结果 各水样中有大量的碱基移码型的直接致突变物和少量的需经代谢活化的碱基移码型的直接致突变物。各水样中的需经代谢活化的碱基置换型致突变物比不需代谢活化的碱基置换型致突变物多。黄河水枯水期的结果大于丰水期，有明显的季节性差别。结论 各水样在净化过程中不能除去这些有机致突变物，反而增加了新的致突变物。     

3R4F参比卷烟主流烟气总粒相物的Ames试验

目的:研究3R4F参比卷烟主流烟气总粒相物(TPM)的致突变作用。方法:采用4种鼠伤寒沙门氏菌菌株TA97、TA98、TA100和TA102,对3R4F参比卷烟的TPM进行Ames试验;筛选出对TPM较敏感的菌株为研究对象,比较体积分数5%和10%的S9混合液的活化能力及不同预培养时间(0、20、40和60min)的致突变作用。结果:在加S9的情况下,TA98和TA100对TPM较为敏感。体积分数5%和10%的S9混合液的致突变作用无明显差异,37℃下预培养20min效果更佳。结论:以TA98和TA100为研究对象,选择体积分数5%的S9混合液,采用预培养改良的Ames试验可有效测定卷烟烟气TPM的致突变作用。     

不同水文期水中非挥发性有机污染物致突变性的比较

应用大孔树脂吸附浓集水中有机物的技术，结合Ames致突变试验，研究了不同水文期的东湖与汉江水源水及其所制成的自来水中非挥发性有机物的致突变性。结果发现：在加与不加体外代谢活化系统（S9）的条件下，除枯水期外，其他水文时期东湖与汉江水源水中非挥发性有机物对TA98菌株的致突变试验为阳性结果；各水文期东湖与汉江自来水中有机物对 TA98和TA100菌株均具有致突变性，且致突变比活性强度均明显高于水源水，各期水样致突变比活性强度由强至依次为平水期＞枯水期＞丰水期。     

冻干肝S—9对前致癌物/前致突变物代谢活化能力的初步观察

<正> 许多致癌物、致突变物都是以前致癌物、前致突变物的形式存在,需经体内代谢活化转变为终末致癌物,终末致突变物之后才具有致癌、致突变作用。这些物质的代谢活化有赖于各种酶的参与,哺乳动物微粒体含有此类酶。目前,多采     

不同水文期水中非挥发性有机污染物致突变性的比较

应用大孔树脂吸附浓集水中有机物的技术,结合Ames致突变试验,研究了不同水文期的东湖与汉江水源水及其所制成的自来水中非挥发性有机物的致突变性.结果发现在加与不加体外代谢活化系统(S9)的条件下,除枯水期外,其他水文时期东湖与汉江水源水中非挥发性有机物对TA98菌株的致突变试验为阳性结果;各水文期东湖与汉江自来水中有机物对TA98和TA100菌株均具有致突变性,且致突变比活性强度均明显高于水源水,各期水样致突变比活性强度由强至弱依次为平水期＞枯水期＞丰水期.     

南湖水质富营养化现状及致突变性研究

目的：摸清南宁市南湖水质富营养化现状及其水质的致突变性。方法：采用常规理化检验方法及小鼠骨髓细胞微核实验进行检测。结果：湖水总氮、总磷和生化需氧量平均含量均明显超标，藻类生长旺盛，绿藻和蓝藻为优势藻种，水质属于重度富营养化。湖水有机浓集物能诱发小鼠骨髓细胞微核率升高，随剂量增加，微核率呈增高趋势。结论：富营养化的南湖水可能具有较强的致突变作用，故应加强治理及研究其富营养化对水质的潜在影响。     

亚硝化煤尘提取物的致突变性研究

本文选用 Ames 试验对亚硝化前后5种烟煤提取物的致突变性进行检测,结果显示,在加和不加 S_9混合液的情况下,5种非亚硝化煤尘提取物均不呈现致突变性。在酸性条件下经亚硝化后,5种烟煤样品中有2种煤尘样品的有机溶剂提取物表现出明显的致突变性,且不需 S_9混合液的代谢活化。在本实验所选剂量范围内,亚硝酸钠不具有致突变性。实验结果提示:煤尘在煤矿工人胃癌发病中可能起一定作用。     

10种常用染发剂的致突变作用研究

目的：研究检测常用染发剂是否具有致突变作用，为指导消费、保护健康提供科学依据．方法：采用鼠伤寒沙门氏菌／哺乳动物肝微粒体酶试验（Ames试验）对国内外的10种知名品牌染发剂进行致突变性检验．结果：所检测的10种国内外知名品牌染发剂均具有阳性致突变作用，其中8种染发剂具有移码突变致突变作用，2种染发剂同时具有移码突变和碱基置换致突变作用．结论：所检测的染发剂具有致突变作用，可对健康产生危害。     

串珠镰刀菌的致突变效应

从食管癌高发地区林县和辉县粮食中心分离的31株串珠镰刀菌培养物的乙醚提取物,用Ames试验和大肠杆菌变异株检测其致突变性,31株提取物不加S9活化、对TA100、TA98、大肠杆菌CM891和ND—160菌株均未显示致突变作用。而加S9活化的28株提取物,有13株对TA100菌株显示致突变效应,其中3株提以物同时也对TA98菌株出现致突变作用。根据以上结果,提示对TA100菌株诱发置换突变型的诱变物可能是亚硝胺类化合物,但还可能有另一种对TA98菌株诱发移码突变型的诱变物存在。     

大明湖水的致突变性研究

将大明湖水样经XAD-2树脂富集萃取物,用Ames试验检测了其致突变性。结果表明,湖心水和出口水有较明显的致突变性,有碱基置换型和移码型致突变作用,并有不经S-9混合物活化而直接致突变的可能。新菌株TA_(102)在加S-9混合物后敏感性增强,在研究地面水致突变作用中有实用意义。     

Vascular and morphogenetic abnormalities associated with exposure of cigarette smoke condensate during chicken and murine embryogenesis

Objective Embryonic movements （EM） and angiogenesis pathways are evolutionarily conserved mechanisms which are essential for proper embryonic development. Deviations in these processes by exposure to cigarette smoke condensate （CSC） may cause vascular and morphogenetic disorders. Methods Using chicken and mouse embryos, we have demonstrated the in vivo effects of CSC on EM, vascular development, and organogenesis. Results Examination of the CSC exposed chicken embryos revealed a significant reduction in EM, stunted growth, deviated pattern of blood vessels, hemorrhages, and localized necrosis. Likewise, mouse embryos that were exposed to CSC at E8.5 and E9.5 died between E11.5 and E12.5, respectively. These mouse embryos showed defects in morphogenesis and remodeling of the embryonic vasculature, while littermate controls showed normal development. Conclusion Cigarette smoking during pregnancy is fatal for growing embryos. CSC may induce the remodeling of embryonic vasculature, leading to various pathologies.     

Antimutagenicity of Propolis Against Some Mutagens in vivo and in vitro

OBJECTIVE: To evaluate the antimutagenicity of propolis in vivo and in vitro. METHODS: Salmonella typhimurium strains TA98 and TA100 were used as a test model in vitro against a direct mutagen DMC and an indirect mutagen 2AF with or without S9 mix, and MN formation of mice bone marrow cell and CAs induction of mice testicle cell were applied as a test model in vivo against two mutagens CP and MMC. RESULTS: The present study clearly demonstrated that propolis could inhibit mutagenicity of both DMC and 2AF directly in a dose-dependent manner, and significant antimutagenic effects (P < 0.05) were obtained in TA98 strain at 2000 and 3000 microg/plate. It also could inhibit mutagenicity of both DMC and 2AF to TA98 strain in a dose-dependent manner, with significant antimutagenic effects (P < 0.05) appeared at 1000, 2000, and 3000 microg/plate. The results of antimutagenicity test in vivo revealed that propolis could inhibit MN formation significantly (P < 0.05) at the doses of 45.0 and 135.0 mg/kg b. w., and decrease the frequency of chromosome aberrants and chromosome aberrant cells significantly (P < 0.05) only at the dose of 135.0 mg/kg b. w. CONCLUSION: The propolis is a good inhibitor for mutagencity of DMC and 2AF in vitro, as well as for CP and MMC in vivo.     

Antimutagenicity of Propolis Against Some Mutagens in vivo and in vitro

INTRODUCTION Propolis (CAS No. 9009-62-5) (sometimes also referred to as bee glue) is the generic name for the resinous substance collected by honeybees from various plant sources. In general, it is composed of 50% resin and vegetable balsam, 30% wax, 10%…     

22种食品在亚硝化后的致突变性

本研究用Ames试验加预培养法检测了22种食品在亚硝化后的致突变性。22种食品包括6种酱油、2种鱼露、2种虾酱、2种香肠、6种鱼干、米面薄脆片、油炸猪皮、酱菜和食品香料。结果表明,16种食品对TA 100有直接致突变性。在本组样品中,虾酱具有最强的致突变性,它的特异致突性为37000个回变菌/g。用HPLC分析了一种前致癌物氨基对乙酚的含量。测得每克虾酱中的含量为439μg。食品在亚硝化后所具有的致突变性,提示了该食物内含有胺或酰胺化合物,它可在体内形成内源性致癌物—亚硝胺。因此,检测食品的致突变性,对防癌有一定意义。     

Would a medium-nicotine, low-tar cigarette be less hazardous to health?

Smoking behaviour and exposure to carbon monoxide, nicotine, and tar were studied in 19 middle-tar smokers. All smoked their own brands for three weeks and then switched to either a conventional low-nicotine, low-tar brand (control) or a medium-nicotine, low-tar cigarette for a further three weeks, the order then being reversed. The medium-nicotine, low-tar brand also had a low delivery of carbon monoxide. With the medium-nicotine, low-tar cigarette mouth-level delivery and intake of nicotine was similar to that with the smokers' usual brands, and significantly greater than with the control low-tar cigarette. Intake of carbon monoxide from the medium-nicotine, low-tar cigarette was significantly less than with either own or control brands. With both low-tar brands mouth-level exposure to tar was reduced relative to smokers' usual cigarettes. There was no evidence, however, that the reduction in tar exposure was greater with the medium-nicotine brand than with the control low-tar cigarette. Both low tar brands were "'oversmoked" relative to subjects' usual middle-tar cigarettes. The medium-nicotine, low-tar cigarette was marginally more acceptable than the control brand, and the particular design used in the study resulted in a lower intake of carbon monoxide. In terms of reducing mouth-level exposure to tar, however, the medium-nicotine, low-tar cigarette had no advantage over the control low-tar product. In part this was because of the ratio of tar to nicotine delivery obtained by human smokers was not the same as that obtained by smoking machine.     

香烟烟雾凝聚物通过AP-1探针调节肺泡上皮细胞γ-GCS限速酶的表达

目的探讨香烟烟雾凝集物(CSC)对肺泡上皮细胞(CCL149)表达限速酶r-GCS的影响与机制。方法用不同浓度的CSC处理CCL149细胞1、4、8、12、24、48 h后,采用反向聚合酶链反应和W est印记法在CSC作用不同时间点检测CCL149细胞表达r-GCS的mRNA和蛋白的水平;脂质体转染及荧光素酶活性检测法测定CSC对大鼠gamm a-GCS重链(GCLC)基因5′-端启动子区域功能的影响;用EMSA法测定AP-1探针的结合水平。结果CSC可刺激CCL-149细胞表达gamm a-GCS,在一定浓度时(>1μg/m l),CCL149细胞用CSC处理后1、4、8 h组-γGCS mRNA的表达水平未见到有明显的差别;而12、24、48 h组-γGCS mRNA的表达水平较对照组明显增高(1.71±0.12 vs.0.67±0.06,P<0.05)。CSC亦能使带有GCLC 5′-端全长的荧光素酶报道基因的荧光素酶的活性增强,与无启动子的空载体对照组比较,CSC刺激后12、24、48 h组荧光素酶的活性均明显增强,其γ-GCS的活性均有升高(0.63±0.24 vs.1.75±0.27,P<0.05)。CSC尚促进AP-1与GCLC的DNA结合水平。结论CSC通过激活氧化应激敏感的转录因子AP-1上调CCL-149细胞内r-GCS的表达。     

Smokers' understandings of cigarette yield labels

An important part of public health policy on the control of smoking is the promotion of a reduction in intake of tar by persons who continue to smoke. One method that may contribute towards such a reduction is to encourage smokers to choose cigarette brands that contain low tar levels. This in turn might be promoted by the comprehensible labelling of cigarette packets with tar yields. We tested our hypothesis that the current information about tar yield on cigarette packets is incomprehensible to smokers on a sample of 498 persons (original sample, 500) who smoked. Only 10 (2%) smokers were able to state the correct tar content of their cigarette. On a scaled range of tar levels in all cigarette brands that are available in Australia, 344 (69.1%) smokers underestimated the level in their cigarette brand. On this scale, 280 (56%) smokers placed randomly chosen tar levels in the wrong category. It was agreed by 360 (72%) smokers that comparative tar yields should be displayed at all points of tobacco sale. It is recommended that a condition of issuing a licence to retail tobacco should be that the tar, nicotine and carbon monoxide yield information for all cigarette brands that are available in a national market should be displayed prominently to the consumer by the retailer.     

ACE基因多态性和吸烟与缺血性脑卒中关系的研究

目的探讨血管紧张素转换酶（ACE）基因多态性和吸烟与缺血性脑卒中（IS）患病的关系。方法应用聚合酶链反应（PCR）和变性高效液相色谱（DHPLC）技术筛查454例IS患者（病例组）和334例非IS患者（对照组）的ACE基因的多态分布，采用非条件logistic回归模型分析基因型、吸烟情况与缺血性脑卒中患病的关系。结果携带有DD基因型和D等位基因的吸烟群体患缺血性脑卒中的相对危险度分别为1．992和1．679；而携带有Ⅱ基因型的吸烟群体患缺血性脑卒中的相对危险度则为0．523。相反，非吸烟IS患者的ACE基因的各基因型和等位基因频率的分布与对照组相比，均无显著性差异（P〉0．10）。结论携带有D等位基因的吸烟群体容易患缺血性脑卒中，但携带有I等位基因的吸烟群体不容易患缺血性脑卒中，ACE基因与吸烟在缺血性脑卒中的发病过程中存在协同作用。     

几种霉制食品及虾酱的诱变性分析

用沙门氏鼠伤寒杆菌 TM_(677)抗8-吖鸟嘌呤正向突变试验检测腊八豆、豆瓣酱、豆腐乳及虾酱的诱变性,均为阴性。模拟人胃情况进行亚硝化处理后,均显不同程度的诱变性,且呈明显的剂量-诱变性效应关系。所含诱变剂前体的种类较多。但制腊八豆的同种同批黄豆未显诱变性,说明诱变剂前体产生于霉制加工过程。如在亚硝化处理前,加 2800ppm的抗坏血酸,可抑制全部阳性效应。     

肺心病标化截缩死亡率与吸烟关系的队列研究

作者采用队列研究方法对农民肺心病标化截缩死亡率与吸烟的关系进行了研究。对３５岁以上的农民２９４９８人５年随访的结果显示：肺心病死亡在全死因中的构成比为３０．３５％，居首位；男女性吸烟率分别为８６．４８％和３８．９６％；男女吸烟者肺心病标化死亡率与不吸烟者差异无显著性，相对危险度（ＲＲ）为１左右（Ｐ＞０．０５）；按性别和年龄分层分析表明各年龄组肺心病标化死亡率随年龄增大而增高，其间无显著性差异（Ｐ＞０．０５）；肺心病标化截缩死亡率随累计吸烟量增加而升高，虽然小剂量短时期吸烟与肺心病标化截缩死亡率间的关系不明显，ＲＲ也为１左右（Ｐ＞０．０５），但是，当累计吸烟总量达一定阈值时，（吸晒烟量达２７０ｋｇ以上，吸香烟量达２００００包以上），其ＲＲ为１．４０～３．９４；归因危险度为１７１～１６１０／１０万人年（Ｐ＜０．０５～０．０１）。