AIRWAY RESPONSES FOLLOWING CHLORINE GAS EXPOSURE

说明： 氯气暴露发生在职业环境中。氯气 吸入对急性和慢性肺反应的影响呈剂量依赖性 对氯气暴露有未知的肺功能下降和 呼吸道刺激。风险因素及控制机制。这个 这项研究的具体目的是确定：(1)哮喘的影响与 既往存在的气道高反应性对肺功能和呼吸道的影响 氯的反应性和炎症反应；(2)氯的影响 浓度对肺功能、呼吸道反应性和炎症的影响 氯气浓度对肺功能和呼吸道的影响 对氯的反应性和炎症反应；以及(3)评估时间 肺功能、呼吸道反应性和炎症的动态变化 对氯的反应。据推测，呼吸道多动症和 较高的氯浓度将导致较大的肺部变化 功能、呼吸道反应性和炎症反应，而这些 在接触氯之后，变化将有不同的时间进程。 这项研究将使用两个受控的人体暴露实验， 采用单盲、重复测量和反平衡设计。这个 两个实验的两个受试组将由21名没有 21例同时患有哮喘和呼吸道疾病的患者 多动症。在实验一中，受试者将暴露15分钟 分别为：(1)百万分之零点四的氯；(2)百万分之1.0的氯；及 (3)过滤空气(控制)。肺功能和呼吸道反应性 在暴露前、暴露后1小时和20小时进行测量。气道口 炎症，由细胞和生化成分决定 诱导痰，将在暴露前65h和暴露后20h进行测量。在……里面 实验二，受试者将分别接触以下各项15分钟：(1) 氯(从实验一测定的浓度)；(2)过滤空气 (控制)。将测量肺功能和呼吸道反应性 暴露前即刻，暴露后3h和72h。引痰会 在曝光前65h、曝光后3h和72h进行。这样做的结果 研究将提供有关一种主要刺激性化学物质的信息 职业环境。特别是，一个大的 风险增加的亚人群，剂量-反应效应，以及 将测定氯气暴露后的时间动态效应。

DESCRIPTION: Chlorine gas exposure occurs in occupational environments. Chlorine gas inhalation results in dose-dependent for acute and chronic pulmonary responses to chlorine exposure are unknown decrements in pulmonary function and respiratory tract irritation. The risk factors and controlling mechanisms. The specific aims of this study are to determine: (1) the effects of asthma with pre-existing airway hyper reactivity on the pulmonary function and airway reactivity and inflammation responses to chlorine; (2) the effects of chlorine concentration on the pulmonary function and airway reactivity and inflammation responses to chlorine concentration on the pulmonary function and airway reactivity and inflammation responses to chlorine; and (3) to assess the time dynamics of the pulmonary function and airway reactivity and inflammation responses to chlorine. It is hypothesized that both airway hyperactivity and higher chlorine concentration will result in larger changes in pulmonary function and airway reactivity and inflammation responses, and that these changes will have differential time courses following chlorine exposure. This study will use two controlled human exposure human exposure experiments, utilizing a single-blind, repeated-measures, and counter- balanced design. The two subject groups for both experiments will consist of 21 individuals with no airway hyperactivity, and 21 individuals with both asthma and airway hyperactivity. In Experiment One, subjects will be exposed for 15 min separately to each of: (1) chlorine at 0.4 ppm; (2) chlorine at 1.0 ppm; and (3) filtered air (Control). Pulmonary function and airway reactivity will be measured immediately pre-exposure and 1 and 20 h post-exposure. Airway inflammation, as determined by cellular and biochemical components from sputum-induction, will be measured 65h pre-exposure and 20 h post-exposure. In Experiments Two, subjects will be exposed for 15 min separately to each of: (1) chlorine (concentration determined from Experiment One); (2) filtered air (Control). Pulmonary function and airway reactivity will be measured immediately pre-exposure and at 3 and 72 h post-exposure. Sputum-induction will be performed 65h pre-exposure at 3 and 72 h post-exposure. The results of this study will provide information on a major irritant chemical relevant to occupational environments. Specially, the susceptibility of a large sub-population at increased risk, the dose-response effects, and the post-exposure time dynamics of the effects of chlorine gas will be determined.