二苯甲烷二异氰酸酯作业工人的气道反应性研究

用支气管组胺激发试验分别测定了64名二苯甲烷二异氰酸酯(MDI)作业工人;47名三氯氧磷作业工人和193名交通警察的气道反应性。吸入组胺后MDI组最大呼气流速峰值(PEFR)较基础值平均下降7.77％,MDI组气道反应性阳性率7.8％,与对照两组比较,差异有显著性。气道反应性增高与吸烟无关,建议对MDI作业工人及接触其它致敏物质的工人进行健康监护时,将气道反应性测定列为常规检查指标。     

二苯甲烷二异氰酸酯作业工人嗜碱粒细胞释放能力的研究

３０例二苯甲烷二异氰酯酯作业开人和１２例哮喘患者的嗜碱粒细胞脱颗粒指数和嗜柘粒细胞脱颗粒试验阳性率均非常显著地高于３５例不接触ＭＤＩ的对照者；哮喘组ＤＩ与抗原特异性ＩｇＥ ＯＤ值高度相关，与非特异性支气管激发试验的阳性符合率为７７．７８％；ＨＢＤＴ的诊断指数为１７２．１％。结果表明，嗜碱粒细胞释放能力依赖于ＩｇＥ水平，在ＭＤＩ哮喘发病中起重要作用，可结合临床用于ＭＤＩ哮喘诊断。     

二苯甲烷二异氰酸酯哮喘患者血嗜碱细胞组胺释放试验

12例二苯甲烷二异氰酸酯(MDI)哮喘患者血嗜碱细胞组胺平均释放率为32.7%,显著高于15名无症状的MDI作业工人和30名不接触MDI的对照者。嗜碱细胞组胺释放试验(HRBT)与临床诊断的符合率为91.7%,诊断指数191.7%。HRBT与特异性IgE、全血组胺、特异性抗原皮肤试验的符合率分别为83.3%、66.7%、70%。结果表明,HRBT是诊断MDI哮喘特异、敏感的体外试验方法。     

二苯甲烷二异氰酸酯对作业工人肺通气功能的影响

近年来 ,二苯甲烷二异氰酸酯 (ＭＤＩ)被越来越广泛的应用在硬质泡沫材料、阻燃材料、衣物的编织材料以及汽车的缓冲材料等生产行业中[1,2 ] 。对于ＭＤＩ引发的作业工人呼吸道症状以及职业性哮喘等致敏作用国外时有报道 ,尤其是低浓度下ＭＤＩ对工人肺通气功能的影响尚存有异议[2 ,3 ] 。为此 ,我们探讨了低浓度ＭＤＩ对作业工人肺通气功能的影响。一、对象与方法1 研究对象 :选择烟台某化工厂接触ＭＤＩ的 5 1名男性工人为观察组 ,所选对象均为身体健康无其他毒物接触史者 ,平均年龄 (33.3± 6 .0 )岁 ;另外选择与实验组条件一致的某事业…     

二苯甲烷二异氰酸酯作业工人血清中抗原特异性IgG抗体水平的研究

目的探讨抗原特异性ＩｇＧ抗体（ＳＩｇＧ）与二苯甲烷二异氰酸酯（ＭＤＩ）哮喘发病的关系。方法观察ＭＤＩ作业工人血清中ＳＩｇＧ水平,并将ＭＤＩ哮喘患者与正常人进行对比。结果ＳＩｇＧ平均ＯＤ值,哮喘组与接触组均显示大于对照组（ｔ值分别为１１３０,９５）。但哮喘组与接触组（ｔ＝１７５）,有症状组与无症状组（ｔ＝１７６）之间差异无显著意义。ＳＩｇＧ抑制试验仅显示ＭＤＩ－ＨＳＡ（人血清白蛋白）对ＳＩｇＧ抗体有明显抑制作用。结论ＳＩｇＧ水平与ＭＤＩ引起的呼吸道症状之间有显著相关关系,且具有较高的诊断价值。     

高效液相色谱测定车间空气中4,4—二苯甲烷二异氰酸酯

４,４二苯甲烷二异氰酸酯（ＭＤＩ）是生产聚合尿烷泡沫塑料和涂料的主要原料之一,其较低的蒸汽压对接触工人可造成健康危害,现行卫生标准为０２ｍｇ／ｍ３。国内目前对ＭＤＩ的检测还没有国家标准方法。本研究采用先进的ＨＰＬＣ测试手段在国内率先建立了测定空气中ＭＤＩ的分析方法,灵敏度高,精度高,特异性强,消耗低并且操作简便。最低检测限为１８μｇ／ｍ３回归直线方程Ｙ＝０２２Ｘ－０３７,相关系数ｒ＝０９９９８,变异系数范围为２０％～８７％,采样效率＞９５％,样品贮存１４天稳定性＞９８％。应用本方法…     

甲苯二异氰酸甲酯所致支气管哮喘患者的支气管激发试验及免疫学研究

对18例临床上诊断为支气管哮喘的TDI作业者进行变应原BPT,并与其它免疫学指标对比观察。发现BPT阳性14例(占77.8％),其中速发反应7例,迟缓反应6例,双相反应1例。BPT阳性者的肺功能指标FVC、FEV_1、MMF、PF、V_(75)、V_(50)、V_(25)等均有明显降低。免疫指标中以IgA、特异性IgE的增高为著,各占7例及9例,并与BPT阳性反应相一致。以上证明了TDI哮喘的变态反应机理,特别是与IgE介导的速发型反应有关。此外,BPT作为一种病因诊断手段,有明显的特异性及实用性。     

Occupational asthma related to low levels of airborne methylene diphenyl diisocyanate (MDI) in orthopedic casting work

Orthopedic plaster casts contain methylene diphenyl diisocyanate (MDI). A few case reports have suggested occupational asthma to MDI in casting work. However, the knowledge of the exposure levels related to the occupational asthma cases is lacking. We report on two occupational asthma cases due to MDI in nurses irregularly applying orthopedic plaster casts, verified with placebo controlled specific inhalation challenge. The levels of MDI in the air were measured in the exposure chamber during the specific inhalation challenges with a quantitative method including filter collection and subsequent liquid chromatography-mass spectrometry (LC-MS) analysis of the isocyanate groups. In order to estimate the level of airborne MDI in casting work, measurements were conducted also in two hospitals during the application and removal of synthetic plaster casts using the same method. The concentrations were well below the occupational exposure limit in both specific inhalation challenge and hospital measurements. Based on our findings, even minor exposure to airborne MDI in casting work can cause an asthmatic reaction in some patients.     

邻苯二甲酐作业哮喘患者的免疫学观察

对10例PA作业哮喘患者进行免疫学指标观察。发现以苯酐为变应原的支气管激发试验(A-BPT)有半数阳性,其中双相反应3例,速发及迟缓反应各1例。血中抗原特异性IgE 及IG(S-IgE,S-IgG)分别有50%及80%阳性,与正常人对照有明显差异。本观察认为PA 哮喘在临床上基本符合一种变应性机制;但鉴于某些病例的非典型性,特别是体内存在较高水平的S-IgG 抗体,因此不能用单一的IgE 介导的速发型变态反应来解释。这种非典型病例更多的可能是一种慢性气道刺激反应以及体内IgG 型抗体增高的全身性反应。     

Dietary Antioxidants and Ozone-Induced Bronchial Hyperresponsiveness in Adults with Asthma

Ozone exposure aggravates asthma, as has been demonstrated in both controlled exposures and epidemiologic studies. In the current double-blind crossover study, the authors evaluated the effects of dietary antioxidants (i.e., 400 IU vitamin E/500 mg vitamin C) on ozone-induced bronchial hyperresponsiveness in adult subjects with asthma. Seventeen subjects were exposed to 0.12 ppm of ozone or to air for 45 min during intermittent moderate exercise. Bronchial hyperresponsiveness was assessed with 10-min sulfur dioxide (i.e., 0.10 ppm and 0.25 ppm) inhalation challenges. Subjects who were given dietary antioxidants responded less severely to sulfur dioxide challenge than subjects given a placebo (i.e., forced expiratory volume in the 1st sec: -1.2% vs. 4.4%, respectively; peak flow: +2.2% vs. -3.0%, respectively; and mid-forced expiratory flow: +2.0% vs. -4.3%, respectively). Effects were more pronounced when subjects were grouped by response to sulfur dioxide at the screening visit. The results suggest that dietary supplementation with vitamins E and C benefits asthmatic adults who are exposed to air pollutants.     

Occupational asthma (OA) with sensitization to diphenylmethane diisocyanate (MDI) presenting at the onset like a reactive airways dysfunction syndrome (RADS)

BACKGROUND: Two types of OA are distinguished: immunological (OA with sensitization) and non-immunological, i.e., irritant induced asthma or reactive airways dysfunction syndrome (RADS). METHODS: We describe the case of a worker who developed respiratory symptoms after a spill of diphenylmethane diisocyanate (MDI) at the workplace. RADS was initially diagnosed and the worker resumed working. The progressive worsening of symptoms and the appearance of symptoms-work relationship one year later, when concentrations of isocyanates were no longer "irritant," suggested immunological OA. RESULTS: The diagnosis was confirmed by specific inhalation challenge test, followed by removal from exposure and complete recovery. CONCLUSIONS: In the case of RADS due to an agent with both irritant and sensitizing properties, history should be repeatedly assessed for a possible symptom-work relationship. If this is found, further investigations should be carried out, including specific inhalation challenges, to confirm the possibility of immunological OA.     

治疗儿童变应性鼻炎对支气管哮喘控制的影响

目的观察治疗儿童变应性鼻炎(allergic rhinitis,AR)对支气管哮喘(bronchial asthma,BA)控制的影响。方法 2009年1月至2010年5月将65例在本院耳鼻咽喉科确诊为支气管哮喘伴变应性鼻炎患儿,将其随机分为观察组(n=35)及对照组(n=30)。两组患儿年龄、性别、治疗前支气管哮喘严重程度分级、肺功能[最大呼气流量(peak expiratory flow,PEF)预计值]等比较,差异无显著意义(P>0.05)(本研究遵循的程序符合本院人体试验委员会制定的伦理学标准,得到该委员会批准,分组征得受试对象监护人的知情同意,并与其签署临床研究知情同意书)。两组均按照支气管哮喘严重程度,采取常规吸入丙酸氟替卡松气雾剂[(100~500)μg/d],2~4次/d治疗,观察组同时联合布地奈德鼻喷剂治疗,第1个月为两侧鼻孔各一喷(64μg/喷),2次/d;第2个月改为1次/d;第3个月隔日1次,连续治疗3个月。治疗期间每个月门诊随访2次,共随访6个月,观察两组临床疗效及肺功能改善情况。结果观察组经联合治疗的总有效率为94.2%(33/35),对照组为73.3%(22/30),两组疗效比较,差异有显著意义(P<0.05)。观察组和对照组治疗后肺功能改善情况(最大呼气流量预计值)比较[(85.73±5.42)%vs.(81.95±4.31)%],差异有显著意义(P<0.05)。结论对于支气管哮喘伴变应性鼻炎患儿,积极治疗变应性鼻炎对控制其支气管哮喘有积极作用。     

河南省支气管哮喘诊治现状调查分析

目的：了解河南省哮喘诊治现状，改进防治对策。方法：对2000年河南省全人群采用分层随机整群抽样调查，依据询问病史体检，确诊哮喘患者。结果：受检人口65033人，哮喘患病率1．05％，延误7天以上就诊者40．00％，诊断率为20．00％，诊断方法单一，治疗管理混乱，仅0．30％的哮喘病人按全球哮喘防治创议（GINA）要求正规治疗管理。结论：向基层宣传普及GINA知识是哮喘防治取得成功的重要措施。     

Assessment and control of exposures to polymeric methylene diphenyl diisocyanate (pMDI) in spray polyurethane foam applicators

In this work we characterize personal inhalation and dermal exposures to diphenyl methane diisocyanate (MDI) and other species in polymeric MDI (pMDI) formulations during spray polyurethane foam (SPF) insulation at 14 sites in New England. We further assess the adequacy of current workplace practices and exposure controls via comparative urinary biomonitoring of the corresponding methylene diphenyl diamine (MDA) pre- and post-shift. MDI and pMDI are potent dermal and respiratory sensitizers and asthmagens, strong irritants of the skin, eyes, and the respiratory tract, and may cause skin burns. This study is the first comprehensive report to-date on the work practices, inhalation and dermal exposures to isocyanates and effectiveness of existing controls during SPF applications.Breathing zone exposures to 4,4′ MDI (n = 31; 24 sprayers, 7 helpers) ranged from 0.9 to 123.0 μg/m3 and had a geometric mean (GM) of 13.8 μg/m3 and geometric standard deviation (GSD) of 4.8. Stationary near field area samples (n = 15) were higher than personal exposures: GM, 40.9 (GSD, 3.9) μg/m3, range 1.4–240.8 μg/m3. Sixteen percent of personal air samples and 35% of area samples exceeded the National Institute for Occupational Health and Safety's (NIOSH) full shift recommended exposure limit (REL) of 50 μg/m3, assuming zero exposure for the unsampled time. 4,4′ MDI load on the glove dosimeters had a GM of 11.4 (GSD 2.9) μg/glove pair/min, suggesting high potential for dermal exposures. Urinary MDA had a GM of 0.7 (GSD, 3.0) μmol MDA/mol creatinine (range, nd-14.5 μmol MDA/mol creatinine). Twenty-five % of urine samples exceeded the Health and Safety Executive (HSE) biological monitoring guidance value (BMGV) of 1 μmol MDA/mol creatinine. We further report on field observations regarding current exposure controls, discuss implications of these findings and opportunities for improving work practices to prevent isocyanate exposures during SPF insulation.