8-Hydroxydeoxyguanosine in leukocyte DNA and urine of quartz-exposed workers and patients with silicosis

Objective: To examine radical-induced DNA damage and its elimination in workers exposed to quartz and in patients with silicosis, and to assess the relationship of these effects to lung function. Methods: Blood and spontaneous urine samples were obtained from active, quartz-exposed workers without silicosis (n=63), and from retired workers with silicosis (n=42). Levels of 8-hydroxydeoxyguanosine (8-OHdG) were determined in peripheral blood leukocyte DNA and urine, by the use of high-performance liquid chromatography coupled with ultra violet- (UV) and electrochemical detection. Results: No significant differences in the mean levels of 8-OHdG in leukocyte DNA and of urinary excretion of 8-OHdG were found between silicosis patients and quartz-exposed healthy workers. However, in the group of silicosis patients with increased oxidative DNA damage the urinary excretion of 8-OHdG was lower than in the corresponding group of active workers without silicosis. In the case of silicosis, urinary 8-OHdG correlated positively, and 8-OHdG in DNA correlated negatively, with forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC). Healthy workers with a personally estimated high dust exposure in the workplace showed higher levels of 8-OHdG in DNA than did workers with moderate dust exposure. No association of 8-OHdG formation and/or elimination with duration of employment, field of activity, smoking or age was found. Conclusion: Our findings suggest that a less effective repair of 8-OHdG is associated with a higher degree of pulmonary airway obstruction in patients with silicosis. Received: 13 August 1999 / Accepted: 5 January 2000     

Assessment of abnormal DNA repair responses and genotoxic effects in lead exposed workers

BACKGROUND: One of the main sources of occupational exposure to lead (Pb) in Turkey is in workers of battery industries. Genotoxic studies in human populations exposed to this metal have had conflicting results. METHODS: Genotoxic effects of Pb were studied in blood cell samples from workers of battery manufactures exposed to Pb compounds by chromosomal aberration (CA) assay and X-ray induced challenge (XRC) assay to assess DNA damage and interference with DNA repair processes after an in vitro exposure of X-ray (1 Gy). The battery manufacturers (n=23) and 23 people who were not occupationally exposed to lead compounds were selected as a control group and classified into categories according to their blood lead levels. RESULTS: The CA frequencies in the exposed and control group were not significantly different (P>0.05) by conventional CA (CCA) assay, however, the XRC assay demonstrated significantly elevated CAs (P<0.05). Statistically non-significant but reduced DNA repair responses have also been observed in lead exposed workers. CONCLUSION: The results of this study showed significant increases in the CAs by XRC assay in Pb exposed workers compared to CCA assay. Our data suggests that Pb exposure may cause reduction in DNA repair capacity and these individuals will be more prone to DNA damage. Therefore, preventive measures should be improved against genotoxic risk in workplaces.     

DNA strand breaks, oxidative damage, and 1-OH pyrene in roofers with coal-tar pitch dust and/or asphalt fume exposure

Objective: To determine the potential for asphalt fume exposure to increase DNA damage, we conducted a cross-sectional study of roofers involved in the application of roofing asphalt. Methods: DNA strand breaks and the ratio of 8-hydroxydeoxyguanosine (8-OHdG) to 2-deoxyguanosine (dG) were measured in peripheral blood leukocytes of roofers. In addition, urinary excretion of 8-OHdG and 8-epi-prostaglandin F_2α (8-epi-PGF) was also measured. The study population consisted of 26 roofers exposed to roofing asphalt and 15 construction workers not exposed to asphalt during the past 5 years. A subset of asphalt roofers (n=19) was exposed to coal-tar pitch dust (coal tar) during removal of existing roofs prior to applying hot asphalt. Personal air monitoring was performed for one work-week to measure exposure to total particulates, benzene-soluble fraction of total particulates, and polycyclic aromatic compounds (PACs). Urinary 1-OH-pyrene levels were measured as an internal biomarker of PAC exposure. Results: Full-shift breathing zone measurements for total particulates, benzene-solubles and PACs were significantly higher for coal-tar exposed workers than for roofers not exposed to coal tar. Similarly, urinary 1-OH-pyrene levels were higher in coal-tar exposed roofers than roofers not exposed to coal tar. Total particulates or benzene-soluble fractions were not associated with urinary 1-OH-pyrene, but PAC exposure was highly correlated with urinary 1-OH-pyrene. When stratified by 1-OH-pyrene excretion, DNA strand breaks increased in a dose-dependent manner, and leukocyte 8-OHdG/dG decreased in a dose-dependent manner. Significant changes in DNA damage appeared to be linked to PACs from coal-tar exposure, although asphalt fume alone was associated with a small but significant increase in urinary 1-OH-pyrene and DNA strand breaks. Conclusions: Results are consistent with previous reports that asphalt or coal-tar exposure can cause DNA damage. Urinary 8-epi-PGF remained relatively constant during the week for virtually all subjects, regardless of exposure indicating that neither asphalt nor coal-tar exposure induces an overt oxidative stress. A small, but statistically significant increase in 8OHdG was evident in end-of-week urine samples compared with start-of-week urine samples in roofers exposed to coal-tar. The increase in urinary 8OHdG coupled with the decrease in leukocyte 8-OHdG/dG, suggests that coal-tar exposure induces protective or repair mechanisms that result in reduced levels of steady-state oxidative-DNA damage. Received: 5 September 2000 / Accepted: 20 February 2001     

hOGG1基因在Cr(Ⅵ)诱导线粒体DNA氧化损伤中的作用

目的探讨hOGG1基因在Cr(Ⅵ)诱导线粒体DNA氧化损伤中的修复作用。方法取不同浓度的Cr(Ⅵ)(0、2、8和32μmol/L)处理L-02肝细胞24h,分别测定细胞内活性氧簇(ROS)与hOGG1 mRNA表达水平和线粒体内8-羟基脱氧鸟苷(8-OHdG)与hOGG1基因表达的人类8-羟基鸟嘌呤DNA糖苷酶蛋白(hOGG1蛋白)水平。结果 8μmol/L和32μmol/L剂量组与对照组比较,细胞内ROS平均水平及线粒体内8-OhdG平均水平均明显增加(P<0.05),而hOGG1基因mRNA水平和线粒体内hOGG1蛋白水平,与对照组比较,2μmol/L剂量组两者水平均上升(P<0.05),32μmol/L剂量组两者水平均降低(P<0.05)。结论 Cr(Ⅵ)可诱导细胞内ROS水平增加,引起线粒体DNA氧化损伤,而hOGG1基因表达水平的改变,影响了线粒体DNA的修复能力。hOGG1基因在Cr(Ⅵ)诱导线粒体DNA氧化损伤中起到了重要的作用。     

Leukocyte 8-hydroxydeoxyguanosine and aromatic DNA adduct in coke-oven workers with polycyclic aromatic hydrocarbon exposure

Objective To investigate the potential for exposure to polycyclic aromatic hydrocarbons (PAHs) to induce oxidative DNA damage, we conducted a cross-sectional study in coke-oven workers employed at an iron–steel factory.Methods The study population contained 119 coke-oven workers from different work areas of the oven and 38 controls. Personal information on age, employment duration, smoking habit and alcohol consumption was obtained at an interview. Leukocyte 8-hydroxydeoxyguanosine (8-OHdG) was measured by high performance liquid chromatography with electrochemical detection. Leukocyte aromatic DNA adducts as effective dose, and urinary 1-hydroxypyren as internal dose, were also measured, and used to analyze the relationship of 8-OHdG with other biomarkers for PAH exposure, tobacco smoke and alcohol consumption.Results The leukocyte 8-OHdG revealed a wide inter-individual variation. The highest 8-OHdG level was detected in bottom-workers of the coke-oven. There were significant differences among the four different work areas (P=0.02). We could not find significant correlation between 8-OHdG levels and urinary 1-hydroxypyrene, but a weakly positive correlation was found between 8-OHdG and leukocyte aromatic DNA adducts among all subjects (r=0.19 P=0.03). We could not observe any effect of smoking and alcohol drinking on 8-OHdG production.Conclusion We could not find clear evidence that PAH exposure induces oxidative DNA damage.     

An application of the challenge assay in boat builders exposed to low levels of styrene--a feasibility study of a possible biomarker for acquired susceptibility.

Sensitivity to carcinogens and susceptibility for malignant diseases may be related to genetic predisposition, e.g. polymorphisms in toxicant-metabolizing enzymes or DNA repair deficiencies. The latter may also be acquired by exposure to substances that interfere with DNA repair processes. Application of the challenge assay to an exposed population may allow scientists to study the interference of DNA repair as an acquired susceptibility phenomenon. The assay was therefore used in a feasibility study to evaluate its application. A group of 14 workers exposed to low levels of styrene (mean < 100 mg/m3 styrene in air; 35 micrograms/l styrene in blood) and a reference of seven controls were investigated for structural chromosomal aberrations using FISH. The rate of exchange-type aberrations per 100 metaphases was 0.14 (95% CI, 0.05-0.31) in controls and 0.22 (95% CI, 0.13-0.36) in exposed workers. The difference is not statistically significant. Interaction with DNA repair was measured in the 14 workers and 2 historical controls using the challenge assay. Exchange-type aberrations per 100 metaphases after X-ray challenge of 1.66 Gy were 13.26 (10.53-16.50) and 16.19 (15.00-17.40) for the controls and exposed, respectively. The difference is statistically significant (p < 0.038). Among the exposed group, the challenge response was also significantly correlated with the cumulative lifetime exposure to styrene (R2 = 0.3996; p < 0.015) but not with the current exposure as measured in blood (R2 = 0.0226; p = 0.700). The challenge responses in the short-term and long-term exposed subgroups were 15.55 (14.23-16.96) and 17.90 (15.64-20.39), respectively, based on sample sizes of 5 and 9, respectively. The difference was not significant. Hence, data from our study are consistent with the hypothesis that long-term exposure to styrene can interfere with DNA repair activities. The lack of statistically significant differences in some of the data may be due to the small sample size and a possible confounding by age in our investigation. Additional data from our ongoing study should clarify this uncertainty.     

Oxidative DNA damage estimated by plasma 8-hydroxydeoxyguanosine (8-OHdG): influence of 4, 4'-methylenebis (2-chloroaniline) exposure and smoking

Oxidative DNA damage may play an important role in the human carcinogenic process. Recently, we reported a case of bladder cancer among 4, 4'-methylenebis (2-chloroaniline) (MBOCA)-exposed workers. By measuring the plasma level of 8-hydroxydeoxyguanosine (8-OHdG), we investigated the association between oxidative DNA damage and MBOCA exposure. In addition, we examined the effects of different confounders on the plasma level of 8-OHdG. We undertook a cross-sectional survey at four MBOCA-producing factories in Taiwan (158 subjects). Plasma 8-OHdG levels and urinary MBOCA concentrations were measured by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Personal characteristics were collected by questionnaire. The workers were classified according to their job titles as exposed (n=57) or unexposed (n=101) groups as well as classified according to urinary MBOCA levels as high urinary MBOCA (>20 microg/g creatinine) (n=45) or low urinary MBOCA (n=108) groups. Neither the MBOCA-exposed workers nor the high urinary MBOCA workers had a significant increase in the mean plasma 8-OHdG level, even after adjustment for potential confounders. Age and gender were significantly positively correlated with plasma 8-OHdG levels. Smokers among high urinary MBOCA workers also had significantly higher 8-OHdG levels than non-smokers among high urinary MBOCA workers. Our study provides evidence that smoking rather than MBOCA exposure induces elevation of plasma 8-OHdG levels among workers exposed to MBOCA, indicating that oxidative DNA damage does not play an important role in the carcinogenic processes of MBOCA.     

焦炉工外周血TH1/TH2型细胞因子表达与IFN-γ、IL-10 DNA甲基化分析

目的了解焦炉逸散物(coke oven emissions,COEs)暴露的焦炉工多环芳烃(polycyclic aromatic hydrocarbons,PAHs)内暴露水平及焦炉工机体外周血白细胞介素-2(interleukin-2,IL-2)、γ-干扰素(interferon-γ,IFN-γ)、白细胞介素-4(IL-4)、白细胞介素-10(IL-10)的表达,及IFN-γ、IL-10表观遗传机制在COEs暴露损伤中的表现。方法随机选取某焦化厂炼焦车间接触COEs的85名工人作为暴露组,同是焦化厂非COEs暴露的47名作业工人作为对照组,采集暴露组及对照组工人晨尿进行碱水解-高效液相色谱荧光法检测1-羟基芘(1-OHPyr)水平,尿肌酐校正;采集空腹外周静脉血,用酶联免疫吸附试验测定血清中IL-2、IFN-γ、IL-4和IL-10的表达;采用飞行时间质谱分析IFN-γ和IL-10的甲基化水平。结果焦炉工人尿1-OHPyr含量高于对照组(F=12.446,P<0.05),且炉侧工和炉顶工高于对照组(P<0.05)。与对照组相比,焦炉工血清IL-2含量降低(F=14.77...     

Urinary 8-hydroxy-2'-deoxyguanosine as a biomarker of oxidative DNA damage in workers exposed to fine particulates

Residual oil fly ash (ROFA) is a chemically complex mixture of compounds, including metals that are potentially carcinogenic because of their ability to cause oxidative injury. In this study, we investigated the association between exposure to particulate matter with an aerodynamic mass median diameter 相似文献   

甲醛暴露工人XRCC1基因多态性与DNA损伤的关系研究

目的探讨甲醛暴露工人DNA修复基因XRCC1多态性与外周血淋巴细胞DNA损伤的关系。方法选择某密度板厂的151名甲醛暴露工人(暴露组)和某推土机厂的112名非甲醛暴露工人(对照组)为研究对象。用气相色谱法检测作业环境的甲醛浓度,应用彗星实验测定研究对象外周血淋巴细胞DNA损伤,以Olive尾距和彗星尾长反映DNA损伤水平,用PCR-RFLP方法分析XRCC1基因的多态性;用多元协方差分析调整工人的年龄、工龄、职业甲醛暴露及吸烟与饮烟情况,比较XRCC1基因不同基因型个体的Olive尾距和彗星尾长。结果使用多元协方差分析校正甲醛暴露工人的年龄、工龄、甲醛暴露水平和吸烟与饮酒情况后,携带Arg280His位点变异基因型个体的Olive尾距和彗星尾长(几何均值分别为4.30和13.42)均显著高于野生型基因型的个体(几何均值分别为3.38和11.71),差异均有显著性(Olive尾距:P<0.05,彗星尾长:P<0.01);未发现XRCC1基因其他3个位点的多态性与甲醛暴露工人Olive尾距和彗星尾长有显著关联。结论XRCC1基因Arg280His位点的多态性影响甲醛暴露工人的DNA损伤水平。     

PC-B2对AFB1致肝细胞DNA损伤及修复影响

目的 探讨原花青素B2（PC-B2）对黄曲霉毒素B₁（AFB₁）所致人胚胎肝细胞（L-02）DNA损伤及修复基因表达影响。方法 取对数期生长良好的L-02细胞随机分为空白对照组、溶剂对照组、PC-B2处理组（3、10、30 μg/mL）、AFB₁染毒组（10、20、30、40 μg/mL）和PC-B2干预组（3、10、30 μg/mL PC-B2+30 μg/mL AFB₁）,利用噻唑蓝法、酶联免疫吸附法和荧光定量PCR技术分别测定细胞增殖活力、细胞上清液8-羟基脱氧鸟苷（8-OHdG）含量及细胞hOGG1基因表达水平。结果 AFB₁可明显抑制L-02细胞增殖活力（P < 0.05）,呈剂量-效应关系;与溶剂对照组比较,30 μg/mL AFB₁组细胞活力[（69.9±2.46）%]明显降低（P < 0.05）,细胞上清中8-OHdG含量[（2.779±0.089）ng/mL]明显升高（P < 0.05）;与30 μg/mL AFB₁组比较,3、10、30 μg/mL PC-B2干预组细胞活力[分别为（70.6±2.67）%、（69.7±1.94）%、（82.4±1.58）%]明显升高（P < 0.05）,细胞上清中8-OHdG 含量[分别为（2.550±0.078）、（2.376±0.109）、（1.873±0.065）ng/mL]明显降低（P < 0.05）;与溶剂对照组比较,30 μg/mL AFB₁组L-02细胞hOGG1基因表达减少（P < 0.05）;与30 μg/mL AFB₁组比较,PC-B2干预组L-02细胞hOGG1表达明显升高。结论 PC-B2可提高肝细胞增殖活力,抑制AFB₁所致肝细胞DNA损伤,其机制可能与调控修复基因hOGG1表达有关。     

职业接触环氧丙烷工人DNA和Hb加合物分析

目的 研究长期接触低浓度环氧丙烷（PO）对职业人群的遗传毒性。方法 对PO作业现场进行环境监测的同时，采集接触组和对照组工人的血样，采用^32P后标记法和N-alkyl Edman气质谱法对DNA加合物（1－HP－腺嘌呤）和血红蛋白加合物（HP－缬氨酸）含量进行了检测和分析。结果 PO车间两个岗位作业工人PO时间加权平均浓度（TWA）分别为2.6mg/m^3和6.9mg/m^3；PO接触组工人的DNA加合物水平高于对照组，差异有非常显著性（P＝0．0012）；血红蛋白加合物水平也明显高于对照组，差异有非常显著性（P＝0．0018）；DNA加合物与血红蛋白加合物量呈正相关（r=0.882)；差异有非常显著性（P＜0．01）。结论 长期接触低浓度PO对职业人群具有细胞遗传学毒性。     

Cytogenetic markers, DNA single-strand breaks, urinary metabolites, and DNA repair rates in styrene-exposed lamination workers

The effect of occupational exposure to styrene on frequencies of chromosomal aberrations and binucleated cells with micronuclei and on single-strand break levels in peripheral blood lymphocytes was studied in 86 reinforced plastic workers and 42 control individuals (including 16 maintenance workers with intermittent, low-dose exposure). In these individuals, the irradiation-specific DNA repair rates and the repair rates of 8-oxoguanines were investigated. We assessed the exposure by measuring the concentrations of styrene in air and in blood and of mandelic acid, phenylglyoxylic acid, 4-vinyl phenol conjugates and regioisomeric phenyl hydroxyethyl mercapturic acids in urine. All these parameters correlated with one another. No clear relationship was found between the styrene exposure and the frequencies of chromosomal aberrations. Binucleated cells with micronuclei were moderately related to the parameters of styrene exposure. We found a negative correlation between all exposure parameters and single-strand breaks. The positive correlation between exposure parameters and DNA repair rates suggests that particular DNA repair pathways may be induced by styrene exposure.     

Rapid and intermediate N-acetylators are less susceptible to oxidative damage among 4,4′-methylenebis(2-chloroaniline) (MBOCA)-exposed workers

Objectives

In this study, we explored the association between a marker of oxidative stress, 8-hydroxydeoxyguanosine (8-OHdG), and genetic polymorphism of the carcinogen-metabolizing enzyme N-acetyltransferase 2 (NAT2) among 4,4′-methylenebis(2-chloroaniline) (MBOCA)-exposed workers.

Methods

The study population was recruited from four MBOCA-producing factories, and included 57 MBOCA-exposed workers and 101 unexposed control workers. Personal characteristics were collected by questionnaire. Plasma 8-OHdG levels were measured by LC/MS/MS. NAT2 alleles were measured by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP).

Results

NAT2 polymorphism influenced the plasma 8-OHdG levels of MBOCA-exposed workers, but not of non-exposed workers. No difference between exposed and control groups was found for the crude 8-OHdG levels among rapid, intermediate, and slow acetylators. After adjusting for gender, age, smoking, and alcohol consumption habit, the 8-OHdG concentration in the MBOCA-exposed workers was 0.18 pg/ml (95% CI −1.80 to −0.12) lower than the control group among rapid and intermediate acetylators. However, the difference between exposed and control groups was not significant for slow acetylators.

Conclusion

Gene–environment interactions could play a role in the carcinogenesis of occupational MBOCA exposure. We suggest that the impact of the NAT2 acetylator status is low, if at all, on the generation of the oxidative stress marker 8-OHdG in the investigated exposed group.     

硒和砷对HepG2细胞氧化应激和DNA氧化损伤及修复的作用

目的研究硒和砷单独及联合作用对HepG2细胞氧化应激和DNA氧化损伤及修复的影响。方法采用不同浓度的硒(2.5、5.0和10.0μmol/L亚硒酸钠)和砷(1.56、3.13、6.25、12.5和25.0μmol/L亚砷酸)为受试物单独或联合处理HepG2细胞。荧光法测定丙二醛(MDA)作为氧化应激的指标,高效液相色谱-电化学检测法(HPLC-EC)测定8-羟基鸟苷(8-OHdG)作为DNA氧化损伤的指标,Western Blot检测hOGG1表达作为DNA氧化损伤修复的指标。结果在硒和砷单独作用的条件下,可观察到:(1)5.0、10.0μmol/L的亚硒酸钠和6.25、12.5、25.0μmol/L的亚砷酸均引起HepG2细胞MDA含量增加、8-OHdG生成增多、hOGG1表达明显下降(P<0.05,P<0.01);(2)较低浓度的亚硒酸钠(2.5μmol/L)具有有限的抑制8-OHdG生成的作用(P>0.05)。在硒和砷联合作用的条件下,可观察到:(1)2.5μmol/L的亚硒酸钠和6.25μmol/L的亚砷酸同时染毒使MDA含量和8-OHdG的生成均较相应砷剂量组下降(P<0.05);(2)2.5μmol/L的亚硒酸钠与6.25、12.5和25.0μmol/L的亚砷酸同时染毒,hOGG1表达与相应砷剂量组比较没有明显差异(P>0.05)。结论5.0、10.0μmol/L的亚硒酸钠和6.25、12.5、25.0μmol/L的亚砷酸均可引起HepG2细胞氧化应激增强、8-OHdG生成增多、hOGG1表达明显下降;一定剂量的硒(2.5μmol/L的亚硒酸钠)对砷诱导的HepG2细胞氧化应激和DNA氧化损伤具有抑制作用,但对砷所致的DNA氧化损伤修复不产生明显影响。     

Smoking modify the effects of polycyclic aromatic hydrocarbons exposure on oxidative damage to DNA in coke oven workers

Purpose

Coke oven emissions containing polycyclic aromatic hydrocarbons (PAHs) are predominant toxic constituents of particulate air pollution that have been linked to increased risk of lung cancer. Numerous epidemiological studies have suggested that oxidative DNA damage may play a pivotal role in the carcinogenic mechanism of lung cancer. Little is known about the effect of interaction between PAHs exposure and lifestyle on DNA oxidative damage.

Methods

The study population is composed by coke oven workers (365) and water treatment workers (144), and their urinary levels of four PAH metabolites and 8-hydroxydeoxyguanosine (8-OHdG) were determined. Airborne samples of exposed sites (4) and control sites (3) were collected, and eight carcinogenic PAHs were detected by high-performance liquid chromatography.

Results

The median values of the sum of eight carcinogenic PAHs and BaP in exposed sites were significantly higher than control sites (P?<?0.01). The study found that the urinary PAH metabolites were significantly elevated in coke oven workers (P?<?0.01). Multivariate logistic regression analysis revealed that the risk of high levels of urinary 8-OHdG will increase with increasing age, cigarette consumption, and levels of urinary 1-hydroxypyrene, and P for trend were all <0.05. Smoking can significantly modify the effects of urinary 1-hydroxypyrene on high concentrations urinary 8-OHdG, during co-exposure to both light or heavy smoking and high 1-hydroxypyrene levels (OR 4.28, 95% CI 1.32–13.86 and OR 5.05, 95% CI 1.63–15.67, respectively).

Conclusions

Our findings quantitatively demonstrate that workers exposed to coke oven fumes and smoking will cause more serious DNA oxidative damage.

     

Oxidative DNA damage is involved in cigarette smoke-induced lung injury in rats

Objective

Reactive oxygen species (ROS) induced by exogenous toxicants are suggested to be involved in carcinogenesis by oxidative modification of DNA. 8-Hydroxyl-2-deoxyguanosine (8-OHdG) has been considered as a reliable biomarker for oxidative DNA damage both in vivo and in vitro studies. But the effect of smoking on oxidative damage has not yet been fully elucidated.

Methods

Wistar rats were exposed to cigarette smoke at concentrations of 20 and 60 % for 30 min, twice/day for 45 weeks. Then the histopathology of lung tissues, levels of ROS, 8-OHdG, and total antioxidant (T-AOC), expression of DNA repair enzymes, e.g. 8-oxyguaine DNA glycosylase (OGG1), and MutThomolog 1 (Oxidized Purine Nucleoside Triphosphatase, MTH1) were determined in urine, peripheral blood lymphocytes, and lung tissue.

Results

The results showed that long-term cigarette smoke exposure can cause obvious damages of lung tissue in rats. In addition, a significant and cigarette smoke concentration-dependent increase in ROS and 8-OHdG were observed compared with the non-exposed control rats. In contrast, the expression of OGG1 and MTH1, and T-AOC levels were obviously decreased after long-term exposure to cigarette smoke.

Conclusion

These findings indicate that long-term exposure to cigarette smoker increases ROS levels, decreases total antioxidant capacity, and interferes DNA repair capacity that eventually induces oxidative DNA damage, which appears to play an important role in cigarette smoke-induced lung injury in rats, and determination of 8-OHdG levels might be a useful method for monitoring oxidative damage in cigarette smokers.     

低浓度砷暴露者皮肤损害及DNA氧化损伤

目的 探讨女性慢性低浓度砷(As)暴露者皮肤损害情况及与DNA氧化损伤的关系。方法 选择山西大同某村长期饮水型低As暴露女性54人(病例组)和经济水平相近的邻村女性18人(对照组)作为研究对象,测定当地水As及研究对象体内尿As水平;并测定尿中8-羟基脱氧鸟苷(8-OHdG)水平。结果 低As暴露组人群体内尿As平均水平为(13.99±4.65)μg/gCr,尿8-OhdG平均水平为(8.61±4.51)ng/mgCr,均高于对照组(P<0.05);尿中8-OHdG与尿As水平呈正相关(r=0.893,P<0.05);尿中8-OHdG水平与水As暴露程度呈正相关(r=0.847,P<0.05);尿8-OHdG水平较高者发生皮肤损害的危险性是较低者的2.838倍(OR=2.838,P<0.05)。结论 低浓度砷As暴露可致机体产生DNA氧化损伤;尿8-OHdG可作为一个稳定的As致氧化损伤生物标志物。     

焦炉工人血清谷胱甘肽硫转移酶活力和尿8-羟基脱氧鸟苷水平

目的 探讨血清谷胱甘肽硫转移酶（GST）和尿8-羟基脱氧鸟苷（8-OHdG）作为焦炉工人多环芳烃（PAHs）暴露生物监测标志的可行性.方法 用高效液相色谱-电化学方法和试剂盒分别检测47名男性焦炉工和31名男性对照者尿8-OHdG水平和血清GST活力;尿1-羟基芘（1-OHP）作为PAHs接触的内暴露标志,采用碱水解-高效液相色谱方法分析.结果 焦炉工人尿1-OHP浓度的中位数（P25～P75）为[5.7（1.4～12.0）μmol/mol Cr],血清GST活力为[22.1（14.9～31.2）U/ml],尿8-O-HdG水平为[1.9（1.4～15.4）μmol/mol Cr],均高于对照组工人[3.0（0.5～6.4）μmol/mol Cr、13.1（9.5～16.7）U/ml、1.3（1.0～4.0）μmol/mol Cr],差异均有统计学意义（P＜0.05或P＜0.01）.以吸烟分层,两组工人尿1-OHP浓度和血清GST活力仅在吸烟者中、尿8-OHdG水平仅在非吸烟者中差异有统计学意义（均P＜0.01）.焦炉工人血清GST活力和尿1-OHP浓度呈正相关（rs=0.31,P＜0.01,n=78）.多元Logistic回归分析显示,与对照工人相比,焦炉工人血清GST活力＞16.7 U/ml和尿8-OHdG水平＞1.8 μmol/mol Cr的OR值分别为13.2和4.4;高体重指数是影响尿8-OHdG水平下降的独立因素.结论 焦炉工人血清GST活力增强和氧化性DNA损伤增加,吸烟和职业暴露有交互作用;血清GST有可能作为PAHs暴露评价的生物标志;尿8-OHdG检测有助于焦炉工肺癌危险度评价.     

焦炉工人外周血淋巴细胞热休克蛋白72水平及与DNA损伤的关系

目的研究焦炉逸散物对焦炉工人外周血淋巴细胞热休克蛋白72（Hsp72）水平的影响及与DNA损伤的关系，探讨Hsp72在细胞损伤保护中的意义。方法选取267名焦炉工人和30名对照，以Western blot法检测外周血淋巴细胞Hsp72的水平，彗星试验检测DNA损伤水平，个体采样采集作业环境空气样本，高效液相色谱法测定环境苯并[a]芘浓度。结果高暴露组工人外周血淋巴细胞Hsp72水平（G±SG）和Olive尾矩（G±SG）分别为1．24±0．42和4．49±1．24，明显高于低暴露组（1．01±0．35和2．99±1．10）和对照组（0．85±0．34和2．40±1．00），差异有统计学意义（P〈0．05）。以全体研究对象Hsp72中位数为界值，将研究对象分为Hsp72高表达组和低表达组，Hsp72高表达的人数相对比率在对照组、低暴露组、高暴露组分别为36．7％、43．1％和58．3％，呈逐渐增高趋势，差异有统计学意义（P=0．003）。在Hsp72高表达组，Hsp72表达水平随着暴露等级升高而升高，其中高暴露组与对照组的差异有统计学意义（P〈0．05），但各组之间Olive尾矩的差异无统计学意义（P〉0．05）。在Hsp72低表达组中，各组Hsp72水平的差异无统计学意义（P〉0．05），而Olive尾矩随暴露等级升高而升高，其中高暴露组与低暴露组和对照组比较，差异有统计学意义（P〈0．01），且明显高于Hsp72高表达组的高暴露组工人。高暴露组Hsp72水平与Olive尾矩呈负相关（r=0．503，P〈0．01）。结论焦炉逸散物可诱导焦炉工人外周血淋巴细胞Hsp72水平升高，Hsp72对细胞DNA损伤具有保护作用。