Cytotoxic and genotoxic potential of respirable fraction of composite dust on human bronchial cells

ObjectiveTo determine the cytotoxic and genotoxic potential of the respirable fraction of composite dust (<4 μm) on human bronchial epithelial cells.MethodsComposite sticks of three commercial dental composites (Filtek Supreme XTE, Grandio, Transbond XT) were ground in an enclosed plexiglass chamber with a rough dental bur (grain-size 100 μm) and the generated airborne respirable dust was collected in a personal cyclone on a teflon filter (pore size 5 μm). Immediately after particle collection, the dust was quantified gravimetrically and the particles were suspended in cell culturing medium. Next, human bronchial epithelial cells (16HBE14o-) were exposed to the suspensions (3 μg/ml–400 μg/ml). After 24 h, cell viability (WST-1 assay) and membrane integrity (LDH assay) were evaluated. Furthermore, the genotoxic effect of a sub-cytotoxic concentration (50 μg/ml) of composite dust was evaluated by the comet assay after 3 h exposure and cell cycle disturbances were analyzed by flow cytometry. Cellular uptake of particles was evaluated by transmission electronic microscope (TEM).ResultsFor all three tested composite materials, a decrease in metabolic activity of 10–35% was observed when the cells were exposed to the highest concentrations (100 μg/ml–400 μg/ml). Toxicity was partially linked to membrane disruption especially after 72 h exposure. All tested composites provoked a mild genotoxic effect after short-term exposure compared to the control groups. TEM revealed that respirable particles of all tested composites were taken up by the cells.SignificanceThe respirable fraction of composite dust only showed cytotoxic effects at the highest concentrations, whereas mild genotoxicity was observed after exposure to a sub-cytotoxic concentration.     

皖西卫生职业学院大学生蠕形螨感染调查分析

目的:了解皖西卫生职业学院大学生蠕形螨感染情况,为采取相应的预防措施提供依据。方法:采用透明胶纸黏贴法对584名2010级高专生进行蠕形螨检查,问卷调查其卫生习惯、居住环境及皮肤性质、家庭住址等。结果:共检查学生584人,阳性人数93人,总感染率为15.92%。男女两性感染率分别为5.56%(2/36)、16.61%(91/548);农村生源感染率为12.62%(38/301),城市生源感染率23.29%(17/73);中学住校生与不住校生感染率分别为16.53%(40/242)、15.50%(53/342)。结论:我院高专学生蠕形螨感染率较低,可能与检查的季节、学校环境条件、个人卫生习惯等因素有关。     

2009年山西省部分煤矿接尘工人工作倦怠情况调查

[目的]了解煤矿接尘工人工作倦怠与工作相关因素的关系,为缓解煤矿接尘工人工作倦怠,保障其身心健康提供理论依据。[方法]2009年抽取山西省7个煤矿的接尘工人2 055人,采用Maslach工作倦怠问卷通用版(MBI-GS)进行调查。[结果]调查2 055人,工作时间长、接尘时间长,工作疲劳度高者工作倦怠较严重;井下工作年限长、接尘工龄长者工作倦怠较严重;对工作满意、个人兴趣爱好广泛者工作倦怠相对较轻。[结论]煤矿接尘工人的工作倦怠受多种工作相关因素的影响。     

Occupational Risk Factors for COPD Phenotypes in the Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study

Introduction: The contribution of occupational exposure to the risk of chronic obstructive pulmonary disease COPD in population-based studies is of interest. We compared the performance of self-reported exposure to a newly developed JEM in exposure-response evaluation. Methods: We used cross-sectional data from Multi-Ethnic Study of Atherosclerosis (MESA), a population-based sample of 45–84 year olds free of clinical cardiovascular disease at baseline. MESA ascertained the most recent job and employment, and the MESA Lung Study measured spirometry, and occupational exposures for 3686 participants. Associations between health outcomes (spirometry defined airflow limitation and Medical Research Council-defined chronic bronchitis) and occupational exposure [self-reported occupational exposure to vapor-gas, dust, or fumes (VGDF), severity of exposure, and a job-exposure matrix (JEM)-derived score] were evaluated using logistic regression models adjusted for non-occupational risk factors. Results: The prevalence of airflow limitation was associated with self-reported exposure to vapor-gas (OR 2.6, 95%CI 1.1–2.3), severity of VGDF exposure (P-trend < 0.01), and JEM dust exposure (OR 2.4, 95%CI 1.1–5.0), and with organic dust exposure in females; these associations were generally of greater magnitude among never smokers. The prevalence of chronic bronchitis and wheeze was associated with exposure to VGDF. The association between airflow limitation and the combined effect of smoking and VGDF exposure showed an increasing trend. Self-reported vapor-gas, dust, fumes, years and severity of exposure were associated with increased prevalence of chronic bronchitis and wheeze (P < 0.001). Conclusions: Airflow limitation was associated with self-reported VGDF exposure, its severity, and JEM-ascertained dust exposure in smokers and never-smokers in this multiethnic study.     

螨制剂舌下免疫治疗对单一和多重致敏变应性鼻炎的疗效评估

目的观察单一和多重变应性鼻炎患者舌下脱敏的疗效异同并分析原因。方法回顾性分析舌下脱敏治疗1年以上单一和多重变应性鼻炎患者终止治疗1年后的疗效,并对粉尘螨变应原组分与其他点刺变应原作同源进化树分析。结果纳入患者50例,舌下免疫治疗显效22例,有效15例,无效13例,总有效率为74%。50例患者中30例(60%)为多重变态反应患者,阳性率最高的前3种变应原依次为蟑螂(83%)、冬季花粉(70%)和蚕丝(63%)。用有序多分类资料比较的秩和检验分析舌下脱敏治疗1年以上单一尘螨过敏患者与多重变态反应患者的疗效,两组总体分布相同。结论使用舌下含服粉尘螨滴剂治疗变应性鼻炎,多重与单一尘螨变态反应患者治疗效果相当。粉尘螨滴剂亦可用于多重变态反应患者常规治疗。     

Long-term safety of subcutaneous immunotherapy with TO-204 in Japanese patients with house dust mite-induced allergic rhinitis and allergic bronchial asthma: Multicenter,open label clinical trial

Background

To evaluate the long-term safety of subcutaneous immunotherapy with TO-204, a standardized house dust mite (HDM) allergen extracts, we conducted a multicenter, open label clinical trial.

Malaria control by residual insecticide spraying in Chingola and Chililabombwe,Copperbelt Province,Zambia

Malaria is endemic in the whole of Zambia and is the leading cause of morbidity and mortality. Prior to 1980, effective malaria control was achieved in the northern mining towns of Chingola and Chililabombwe by means of annual residual spraying programmes. In the 1970s, incidence rates were as low as 20/1000 p.a., but by 2000 had increased to 68/1000 p.a. in Chingola and to 158/1000 p.a.in Chililabombwe. Konkola Copper Mines (KCM) initiated a malaria control programme in which all dwellings in the two towns and within a 10-km radius were sprayed with either dichlorodiphenyltrichloroethane or a synthetic pyrethroid (Icon by ZENECA or Deltamethrin by Aventis). Houses were sprayed in November and December 2000, at the start of the peak transmission period. There was a statistically significant reduction in malaria incidence recorded at KCM health facilities in the two towns, representing a protective incidence rate ratio of 0.65 (95% CI 0.44, 0.97) when comparing the post-spraying period with the corresponding period of the previous 2 years. This reduction followed a single round of house spraying during a year with higher rainfall than the preceding two and in an area where chloroquine was first-line treatment. This house-spraying programme is an example of private/public sector collaboration in malaria control.