烹调油烟冷凝物对DNA链损伤作用的实验研究

目的；探讨烹调油烟冷凝物对人外周血淋巴细胞DNA的损伤作用。方法：采用单细胞凝胶电泳检测不同浓度的烹调油烟冷凝物处理60min后的人外周血淋巴细胞的DNA单链断裂，双链断裂及DNA－蛋白交联的情况。结果：各剂量的烹调油烟冷凝物均可引起DNA单、双链断裂（与对照组比较：P＜0．05），100μg/ml及其以上浓度的烹调油烟冷凝物可诱导DNA－蛋白交联的形成（与对照组比较P＜0．05），交联率分别为21．35％，27．20％，34．30％，并存在着明显的剂量－反应关系。结论：烹调油烟冷凝物能引起人外周血淋巴细胞DNA的损伤，DNA的损伤可能是烹调油烟致细胞恶性转化的重要机制之一。     

食用油烟对大鼠肺Ⅱ型细胞毒性及与氧化应激的关系

[目的 ]研究食用油烟对大鼠肺Ⅱ型细胞的细胞毒性、DNA损伤及其与氧化应激的关系。 [方法 ]采用MTT比色法、溴乙锭荧光法和单细胞凝胶电泳技术 ,分别测定食用油烟对大鼠肺Ⅱ型细胞的细胞毒性、DNA交联和DNA链的断裂作用 ,并用抗氧化剂N 乙酰半胱氨酸 (NAC)进行干预。 [结果 ]食用油烟对大鼠肺Ⅱ型细胞具有细胞毒作用 ,对DNA既有交联作用又有链断裂作用 ,在受试剂量范围内呈剂量 反应关系。染毒前对大鼠肺Ⅱ型细胞用抗氧化剂NAC预处理 ,可降低食用油烟对大鼠肺细胞的细胞毒性和DNA损伤作用。 [结论 ]食用油烟对大鼠Ⅱ型细胞以及DNA的损伤与氧化应激有关     

危险品货运站空气污染物对DNA的损伤作用

目的探讨危险品货运站空气污染物的DNA损伤作用。方法应用SOS/umu试验,大鼠肺Ⅱ型细胞的DNA交联试验和单细胞凝胶电泳试验,检测危险品货运站空气污染物对DNA的损伤情况。结果空气污染物在81,163,325,650μg/10μl的剂量范围,不加S9活化系统的条件下,污染物显示遗传毒性,存在剂量-反应关系(r=0.994,P<0.01);加入S9活化系统后,污染物未显示出遗传毒性。在1.02,2.03,4.06,8.13 mg/ml的剂量范围内,污染物能引起大鼠肺Ⅱ型细胞DNA产生双链间的交联和单链断裂,存在剂量-反应关系(r交联=0.981,r断裂=0.987,P<0.01)。结论危险品货运站空气污染物具有DNA损伤作用。     

烹调油烟对大鼠肺细胞的氧化损伤作用

以大鼠Ⅱ型肺细胞为实验对象，研究了烹调烟颗粒提取物（以下简称油烟）对肺细胞的毒性作用，及其与氧化应激作用的关系。结果表明，油烟对大鼠肺Ⅱ型细胞具有细胞毒作用，对细胞DNA既可产生双链间交联又可造成单链断裂，可诱导肺细胞脂质过氧化产物丙二醛生成量增加，以及谷胱甘肽含量降低，在受试剂量范围内呈剂量－效应关系和时间－效应关系，染毒前对大鼠Ⅱ型肺细胞用抗氧化剂N－乙酰半胱氨酸预处理，则可降低油烟对大鼠肺细胞的细胞毒性和DNA损伤作用，研究结果初步证实油烟可以导致大鼠Ⅱ型肺细胞的细胞活力下降，产生DNA双链交联与DNA单链断裂，油烟对肺细胞的上述毒性作用与氧化应激有关，其可能途径为促进脂质过氧化与干扰谷胱甘肽抗氧化防御系统等。     

铁路危险品货运站空气污染物对肺细胞DNA的损伤作用

探讨铁路危险品货运站空气污染物对大鼠肺Ⅱ型细胞DNA的损伤作用。[方法]应用大鼠肺Ⅱ型细胞的原代培养技术,结合四氮甲基唑蓝（MTT）比色法、DNA交联试验和单细胞凝胶电泳试验,检测了铁路危险品货运站空气污染颗粒提取物对大鼠肺Ⅱ型细胞生长的抑制作用及对DNA的损伤情况。[结果]在1．02、2．03、4．06、8．13mg/ml的浓度范围内颗粒提取物能引进大鼠肺Ⅱ型细胞DNA产生双链间的交联和单链断裂,并存在剂量－反应关系（r交联＝0．981,r断裂＝0．987,P＜0．01）。[结论]铁路危险品货运站空气污染颗粒提取物对大鼠肺Ⅱ型细胞DNA具有明显的损伤作用,其损伤程度与染毒浓度和染毒时间有关。     

铁路危险品货运站空气颗粒提取物对大鼠肺细胞的损伤及抗氧化剂的干预作用

目的了解铁路危险品货运站空气颗粒提取物对大鼠肺Ⅱ型细胞的损伤,并探讨多种抗氧化剂的干预作用。方法原代培养SD大鼠肺Ⅱ型细胞分别以N-乙酰半胱氨酸（NAC）、维生素C（VC）和维生素E（VE）等抗氧化剂预处理,加入某铁路危险品货运站空气颗粒提取物染毒。用四甲基偶氮唑盐比色法、溴乙锭荧光法检测大鼠肺Ⅱ型细胞的生长情况和DNA交联的形成。结果经1．02～8．13mg／ml提取物染毒,大鼠肺Ⅱ型细胞的吸光度（A）值明显下降,有剂量-反应关系（r=0．962,P〈0．05）,经过终浓度为10-80mmol／L的NAC处理后,各实验组细胞的A值升高（P〈0．01）,加入终浓度为10mmol／L的NAC、VC和VE,各实验组细胞的A值升高,（P〈0．01）。经1．02-8．13mg／ml空气颗粒提取物染毒,大鼠肺Ⅱ型细胞DNA交联率上升,有剂量．反应关系（r=-0．981,P〈0．01）,加入终浓度为10mmol／L的VC和VE,各实验组DNA交联率下降（P〈0．05）。结论铁路危险品货运站空气颗粒提取物能导致大鼠肺Ⅱ型细胞损伤并具有致DNA交联作用,NAC、VC和VE等抗氧化剂能拮抗这些作用。     

烹调油烟雾诱导核酸氧化损伤及其标志物8-羟基脱氧鸟苷的形成机制

目的 了解烹调油烟雾的遗传毒性效应。方法 以核酸加合物8-羟基脱氧鸟苷(8-OHdG)作为DNA氧化损伤的生物学标志物,用高效液相色谱-电化学检测法(HPLC-EC)对烹调油烟雾染毒的小牛胸腺DNA及Wistar大鼠气管灌注染毒的肺组织DNA中8-OHdG进行定量检测,通过气质联用法(GC-MS)进行有机成分和原子吸收法(AAS)进行无机元素分析,并从混合污染物化学组成成分的角度推断了烹调油烟雾造成DNA氧化损伤的分子机理。结果体外试验表明烹调油烟雾的各组分,包括油烟冷凝物、残留油、油烟颗粒物、油烟挥发性有机物均能能诱导DNA氧化产生8-OHdG,产生量的顺序为残留油>冷凝物>油烟颗粒物>油烟挥发性有机物。体内实验结果表明油烟冷凝物可诱导大鼠肺组织DNA的氧化且具有剂量一反应关系和时间一效应关系。结论烹调油烟雾具有明确的遗传毒性,可诱导核酸氧化产生加合物8-OHdG,其机制可能是烹调油混合污染物中存在痕量金属离子如Fe2+、Cu2+等,介导Fenton反应生成羟自由基,直接进攻DNA造成氧化损伤。     

煤烟对大鼠肺Ⅱ型细胞DNA损伤作用的研究

目的探讨煤烟对大鼠肺Ⅱ型细胞DNA的损伤作用.方法采用单细胞凝胶电泳法(SCGE)和溴乙锭荧光法(EFA)结合细胞原代培养技术检测了煤烟颗粒提取物对大鼠肺Ⅱ型细胞DNA单链断裂作用和双链交联形成作用.结果煤烟颗粒提取物在15～120 mg/L的浓度范围内具有细胞毒性,受试物剂量和检测到的A值存在剂量-反应关系(r=-0.943, P<0.05).在10～40 mg/L的剂量范围内可以引起细胞DNA发生单链断裂和DNA双链交联作用.与对照组相比,各剂量组检测到的DNA交联率分别增加了18.2%、23.7%和31.4%,最高剂量组检测到的平均彗尾长度是对照组的3.6倍.结论煤烟可以导致肺Ⅱ型细胞DNA的损伤.     

烹调油烟对暴露人群的免疫损伤作用

[目的 ]检测烹调油烟对人外周血淋巴细胞的毒性作用 ,并分析烹调油烟对职业暴露人群的免疫损伤作用 ,为全面评价烹调油烟的健康危害提供依据。 [方法 ]从居民厨房脱排油烟机的集油杯中采取烹调油烟冷凝物 ,用二甲基亚砜 (DMSO)配成不同浓度的烹调油烟冷凝物乳液 ,应用MTT法检测烹调油烟冷凝物对人外周血淋巴细胞的毒性作用。以餐饮行业厨师 87人为暴露组 ,管理人员 65人为对照组进行流行病学调查。测定外周血免疫球蛋白和T淋巴细胞转化率 (PBLT) ,采用多因素分析方法分析职业暴露烹调油烟对机体免疫功能的影响。 [结果 ]不同浓度烹调油烟冷凝物受试组间的吸光度 (A)值差异有显著性 (P <0 .0 1) ;受试物浓度在 12 5 μg /ml以上时 ,各浓度组与DMSO对照组的吸光度(A)值都存在显著性差异 ,而且各浓度组吸光度 (A)值随测试浓度的升高而递减。暴露组IgG、IgA和PBLT明显低于对照组 ,而且与暴露年限存在剂量 效应关系。 [结论 ]烹调油烟对人外周血淋巴细胞具有一定的毒性作用 ,并且存在剂量 反应关系。烹调油烟对机体的体液免疫和细胞免疫功能均有一定的影响     

β-胡萝卜素与香烟烟气颗粒物对体外大鼠肺细胞毒性的交互作用

[目的 ]研究 β 胡萝卜素对香烟烟气颗粒物致肺细胞毒性的交互作用。[方法 ]建立大鼠肺Ⅱ型细胞体外培养模型 ,加入 β 胡萝卜素或 /和香烟烟气颗粒物用MTT比色法检测细胞活性。[结果 ] β 胡萝卜素剂量在 0 1～ 0 5 μg/ml时 ,肺细胞活性明显增加 ;剂量在 1 0～ 2 0 μg/ml时 ,肺细胞活性明显降低。β 胡萝卜素在 0 2 μg/ml剂量时 ,可抑制香烟烟气颗粒物毒性 ;而在 0 5～ 2 0 μg/ml剂量范围内可增强香烟烟气颗粒物的细胞毒性作用。[结论 ] β 胡萝卜素在 0 1～2 0 μg/ml剂量范围内对大鼠肺细胞的生长具有先促进后抑制的双重作用。β 胡萝卜素对香烟烟气颗粒物肺细胞毒性存在交互作用 ,低浓度时表现为拮抗作用 ,高浓度时为协同作用。其交互作用可能是在细胞内实现的     

甲基叔丁基醚致DNA损伤的体内和体外研究

目的 探讨甲基叔丁基醚（MTBE）对动物致癌的机制.方法 小鼠经呼吸道染毒MTBE 20 d后,取肝、肾、肺细胞进行单细胞凝胶电泳（SCGE）、DNA交联试验及肺和肾组织中丙二醛（MDA）含量测定.对体外培养的大鼠肺Ⅱ型细胞、肝细胞进行SCGE、DNA交联试验和程序外DNA合成试验（LDS）.结果 MTBE 1 440、4 968 mg/m^3组染毒小鼠肝细胞、各剂量组肾细胞、4 968 mg/m^3组肺细胞DNA迁移距离均大于阴性对照组;肝细胞DNA迁移距离与MTBE浓度有剂量-反应关系（r=0.997,P=0.003）.MTBE1 440、4 968 mg/m^3组雌性小鼠及4 968 mg/m3组雄性小鼠肾MDA含量高于阴性对照组,差异有统计学意义（P＜0.05）.MTBE浓度＞0.050mmol/L时,大鼠肺Ⅱ型细胞、肝细胞DNA迁移距离较阴性对照组增加,差异有统计学意义（P＜0.05）,且DNA迁移距离与MTBE浓度有剂量-反应关系（r肺=0.967,T肝=0.963,均P＜0.05）;5.0、10.0 mmol/L MTBE组大鼠肺Ⅱ型细胞、肝细胞的3H-TrR掺入量每分钟脉冲数（CPM）均高于阴性对照组,差异有统计学意义（P＜0.05）;各剂量组小鼠肝细胞、大鼠肺Ⅱ型细胞和肝细胞的DNA交联率与阴性对照组的差异均无统计学意义（P＞0.05）.结论 MTBE对DNA有损伤作用,细胞DNA断裂和脂质过氧化是其引起动物肝、肾肿瘤的可能机制之一.     

氯化镉所致DNA损伤及锌的拮抗效应的研究

目的通过体外实验,了解氯化镉(CdCl2)对中国仓鼠肺成纤维细胞(V79细胞)的直接DNA损伤作用及锌的拮抗作用,初步探讨镉的遗传毒性机制及预防措施。方法采用甲基四唑法(MTT法)了解CdCl2对于V79细胞的毒性,通过碱性单细胞凝胶电泳常用的几个评价指标,研究CdCl2体外对于V79细胞DNA的断裂损伤,并采用生理浓度ZnCl2(10μmol/L)加以拮抗。结果MTT试验中,CdCl2对于V79细胞的毒性随染毒剂量增加而增高,呈线性关系,线性方程为:y=-0.009 4x 94.472;在碱性单细胞凝胶电泳中,CdCl2单独染毒,随着染毒剂量增加,DNA损伤加重,而锌具有明显的拮抗作用。结论本实验条件下,CdCl2能造成V79细胞DNA损伤,生理浓度的锌可以拮抗镉的DNA损伤效应。     

SiO2粉尘介导的DNA损伤及其影响因素的研究

目的 研究小剂量（7.5-120.0μg/ml)SiO2粉尘对中国仓鼠肺成纤维细胞（CHLF）的DNA损伤作用。方法 采用彗星试验，按SiO2粉尘不同的作用浓度和时间分组来观察DNA损伤，通过去铁胺（DFX）和盐酸维拉帕米（Ver)的作用间接观察钙离子和羟自由基对DNA损伤的影响。以彗星尾长作为DNA损伤程度的评价指标。结果 与对照组相比，SiO2明显增加了CHLF的DNA迁移距离，差异有显著性（P＜0．01）；在7．5－120．0μg/ml剂量范围内，彗星尾长随SiO2剂量的增加而增加，2h组的DNA损伤比1h组更严重。0.5-2.0mmol/L DFX和2.5-20.0μg/ml Ver能有效减轻90μg/ml SiO2所致的DNA损伤，其保护作用随浓度加大而增加。结论 小剂量SiO2有致CHLF DNA损伤的作用，损伤过程中有羟自由基和钙离子的参与，抗氧化剂和钙拮抗剂可对抗SiO2对机体DNA的损伤作用。     

Cooking oil fume-induced cytokine expression and oxidative stress in human lung epithelial cells

Epidemiological studies have shown an association between exposure to indoor air pollution from Chinese-style cooking and risk of lung cancer among Chinese females. Several toxic substances have been identified in cooking oil fumes (COF) collected from heated rapeseed oil. In this study, we examined the biological effects of COF on CL3 human lung epithelial cells. Exposure to 200 microg/ml COF significantly reduced cell growth within 4 days. In addition, we examined the effect of COF on TGFbeta1, TGFbeta2, IL-6, IL-8, and IFN-gamma gene expressions with the RT-PCR method. We found that TGFbeta1 mRNA levels increased after exposure to 200 microg/ml COF for 24 h. Similarly, exposure to 10 microM benzo[a]pyrene or 100 nM 12-O-tetradecanoylphorbol-13-acetate increased TGFbeta1 mRNA levels at 24 h. The mRNA levels of TGFbeta2, IL-6, IL-8, and IFN-gamma did not increase after treatment with COF, benzo[a]pyrene, or 12-O-tetradecanoylphorbol-13-acetate. COF-induced TGFbeta1 production was confirmed by quantification of TGFbeta1 in conditioned medium with enzyme-linked immunosorbent assay. Exposure to 200 microg/ml COF significantly increased TGFbeta1 secretion in a time-dependent and dose-dependent manner. It has been demonstrated that reactive oxygen intermediates induce TGFbeta1 gene expression. When CL3 cells were exposed to 200 microg/ml COF for 15 min, there was an increase in intracellular peroxide formation with the dichlorofluorescein method. Furthermore, treatment with 200 microg/ml COF for 12 h also significantly induced lipid peroxidation in CL3 cells. Our results show that exposure to COF inhibits cell growth, increases TGFbeta1 secretion, and induces oxidative stress in CL3 lung epithelial cells. This suggests that TGFbeta1 and oxidative stress play a role in the biological effects of COF on lung epithelial cells.     

氧化型染发剂DNA交联作用的研究

采用溴乙锭荧光法测定氧化型染发剂的主要成分对苯二胺（ＰＰＤ）、过氧化氢（Ｈ２Ｏ２）和ＰＰＤ－Ｈ２Ｏ２混合物对小牛胸腺ＤＮＡ的双链间交联形成作用。结果表明：用０～６％的对苯二胺及０～３％的Ｈ２Ｏ２对小牛胸腺ＤＮＡ直接染毒，３７℃３０ｍｉｎ时无双链间ＤＮＡ交链的形成；而ＰＰＤ和Ｈ２Ｏ２发生氧化反应后则具有双链ＤＮＡ交联形成作用并具有剂量反应关系（ｒ＝０．８２９，Ｐ＜０．０１），在受试剂量为０～０．８％（以对苯二胺含量计）时，氧化型对苯二胺的ＤＮＡ交联作用增加了４．２倍。研究结果提示，ＤＮＡ交联作用可能是氧化型染发剂遗传毒作用过程中ＤＮＡ损伤的一种方式。     

Cooking Oil Fumes and Lung Cancer: A Review of the Literature in the Context of the U.S. Population

There is growing evidence that exposure to cooking oil fumes (COF) is linked to lung cancer. Existing literature on this risk was reviewed, specifically as it may relate to potentially at-risk populations such as Chinese immigrants and restaurant workers in the United States. Studies were identified by searching the NCBI database with key terms. All studies that examined the significance, prevalence, and/or mechanism(s) of the association between COF exposure and cancer (all types) were included. A majority of epidemiologic studies found associations between lung cancer and COF exposure. All studies that examined the mechanisms underlying the risk found evidence for mutagenic and/or carcinogenic compounds in COF extract and/or molecular mechanisms for COF-induced DNA damage or carcinogenesis. The evidence reviewed underscores the need to thoroughly investigate the association among at-risk groups in the United States, as well as to develop and assess concrete interventions to reduce these risks.     

Influence of exposure regimen on nitrogen dioxide-induced morphological changes in the rat lung

Experiments were performed to study the influence of concentration, exposure pattern, and length of exposure on the degree and extent of morphological alterations in the NO2-exposed rat lung. Four weeks of continuous exposure to 20 mg NO2/m3 consecutively revealed damage and loss of cilia, replacement of desquamated type I pneumocytes by type II pneumocytes resulting in a cuboidal epithelial lining, an influx of alveolar macrophages, and hypertrophy and hyperplasia of the bronchiolar epithelium. The animals recovered almost completely from the induced lesions within 8 days. Continuous exposure to 1, 2.5, or 5 mg/m3 displayed minimal alterations in the 5 mg/m3 group. The effects increased with exposure time. Intermittent or continuous exposure to 20 mg NO2/m3 resulted in minor differences after 4 weeks. The onset of the lesions was delayed and the massive influx of alveolar macrophages in the continuously exposed animals failed to appear in the intermittently exposed animals. This work demonstrates that in subacute experiments: Concentration plays a more important role in inducing pulmonary lesions than exposure time when the product of concentration and time is kept constant. This effect is stronger during intermittent exposure than during continuous exposure. Continuous exposure seems to be a more important factor with regard to a macrophage response than intermittent exposure. The rat lung has a large capacity to repair almost completely from damage caused by short-term NO2 exposure.     

In vitro genotoxicity assessment of commercial quartz flours in comparison to standard DQ12 quartz

Crystalline silica has been classified as a human carcinogen, but there is still considerable debate on its variable fibrogenic and carcinogenic potential. We investigated genotoxicity of a panel of four quartz flours in comparison to DQ12 standard quartz with similar size and surface area, using single cell gel electrophoresis (SCGE) or comet assay. A549 human lung epithelial cells were incubated for 4 hours with different concentrations of quartz ranging from 1.6 to 200 micrograms/cm2 and cytotoxicity was assessed using leakage of lactate dehydrogenase (LDH), trypan blue exclusion and conversion of a metabolic substrate (MTT). DNA strand breakages were seen with all quartzes at an in vitro concentration of 200 micrograms/cm2. At this concentration all tests and quartz samples showed significant cytotoxicity. The most toxic quartz flour (Qz 2/1-C) but not DQ12, showed an increase in strand breaks at 40 micrograms/cm2 in cell culture. At this concentration no cytotoxicity was seen with LDH and MTT, but a significant increase in cells with trypan blue uptake was noted. No differences in tail moment percentage were observed at equal concentrations of different quartz flours. Also no correlation between DNA damage and OH-radical generation or surface radicals as measured by electron spin resonance was observed. We conclude that quartzes do not cause strand breaks without concomitant cell toxicity and a sufficient in vitro concentration of > 40 micrograms/cm2 can only be reached in vivo with instillation of massive doses (> 100 mg). Therefore, in vitro genotoxicity found here is unlikely to explain the genotoxicity observed in in vivo studies with the same and other quartzes.