空气污染与儿童哮喘

工业化导致的空气污染是儿童哮喘发生、发展的高危因素之一。常见的空气污染物种类繁多,如交通相关空气污染物、多环芳香烃、香烟烟雾、尘埃颗粒及细颗粒物 PM 2.5等,均与儿童哮喘密切相关。它们通过各种相关信号通路,从而调节哮喘进程;同时空气污染导致的哮喘相关基因表观遗传学改变、上皮间充质转化及遗传多态性等亦影响儿童哮喘个体异质性及诊疗个体化。目前,空气污染与儿童哮喘研究已取得一定进展,但其确切机制仍需进一步研究。本文就常见的空气污染物参与儿童哮喘的发生、发展及其机制进行阐述。     

Air pollution, bronchial asthma, and acute respiratory infections in minors, Habana City

OBJECTIVE: To identify the relationship between emergency visits for acute respiratory illnesses, acute bronchial asthma crisis (ABAC) and acute respiratory infections (ARI), in children less than 14 years of age, and the daily changes of air pollutant levels, in two central hospitals of Havana City, between October 1st 1996 and March 16 1998. MATERIAL AND METHODS: An ecological time series study was conducted. We assessed the relationship between the presence of acute respiratory illnesses, ABAC, and IRA, and exposure to levels of particles less than 10 microg/m3 (PM10), smoke, and sulfur dioxide (SO2); negative binomial regression models were used to assess latency periods of one to five days as well as the cumulative effect of seven days before the emergency visit. RESULTS: The levels of atmospheric pollutants were low, in general. The 24-hour mean values for PM10 levels, smoke, and SO2, were 59.2 microg/m3 (SD=29.2), 27.7 microg/m3 (SD=21.2), and 21.1 microg/m3 (SD=20.1), respectively. An increase of 20 microg/m3 in the daily average of black smoke was associated with a 2.2% increase (95% CI 0.9-3.6) in the number of emergency visits for ABAC. A 20 microg/m3 increase in the daily average of black smoke and SO was associated with an increase in ARI of 2.4% (95% CI 1.2-3.6), and 5% (95% CI 1.3-5.3), respectively, with a 5-day lag. We also observed a cumulative effect for all the contaminants studied. CONCLUSIONS: These results suggest that air pollution levels in Havana City affect children's respiratory health; therefore implementation of control measures is necessary, especially those aimed at decreasing motor vehicle exhaust fumes. The English version of this paper is available at: http://www.insp.mx/salud/index.html.     

Air pollution induced asthma and alterations in cytokine patterns

In recent decades, clinicians and scientists have witnessed a significant increase in the prevalence of allergic rhinitis and asthma. The factors underlying this phenomenon are clearly complex; however, this rapid increase in the burden of atopic disease has occurred in parallel with rapid industrialization and urbanization in many parts of the world. Consequently, more people are exposed to air pollutants than at any point in human history. Worldwide increases in allergic respiratory disease have mainly been observed in urban communities. Epidemiologic and clinical investigations have suggested a strong link between particulate air pollution and detrimental health effects, including cardiopulmonary morbidity and mortality. The purpose of this review is to provide an evidence-based summary of the effects of air pollutants on asthma, focusing on particulate matter PMs, diesel exhaust particles (DEPs), and ozone as major air pollutants. An overview of observational and experimental studies linking these pollutants with asthma will be provided, followed by consideration of the mechanisms underlying pollutant induced immune response and inflammation. The cytokine response will be viewed in depth and a brief discussion of future research and clinical directions is provided.     

Outdoor air pollution, climatic changes and allergic bronchial asthma.

Both the prevalence and severity of respiratory allergic diseases such as bronchial asthma have increased in recent years. Among the factors implicated in this "epidemic" are indoor and outdoor airborne pollutants. Urbanisation with its high levels of vehicle emissions and Westernised lifestyle parallels the increase in respiratory allergy in most industrialised countries, and people who live in urban areas tend to be more affected by the disease than those of rural areas. In atopic subjects, exposure to air pollution increases airway responsiveness to aeroallergens. Pollen is a good model with which to study the interrelationship between air pollution and respiratory allergic diseases. Biological aerosols carrying antigenic proteins, such as pollen grains or plant-derived paucimicronic components, can produce allergic symptoms. By adhering to the surface of these airborne allergenic agents, air pollutants could modify their antigenic properties. Several factors influence this interaction, i.e., type of air pollutant, plant species, nutrient balance, climatic factors, degree of airway sensitisation and hyperresponsiveness of exposed subjects. However, the airway mucosal damage and the impaired mucociliary clearance induced by air pollution may facilitate the penetration and the access of inhaled allergens to the cells of the immune system, and so promote airway sensitisation. As a consequence, an enhanced immunoglobulin E-mediated response to aeroallergens and enhanced airway inflammation favoured by air pollution could account for the increasing prevalence of allergic respiratory diseases in urban areas.     

1-磷酸鞘氨醇与支气管哮喘

1-磷酸鞘氨醇是一类生物活性鞘脂类代谢物,不仅可以作为第一信使与G蛋白耦联受体结合,也可以作为第二信使参与调节细胞的发育、增殖、重塑、生存和活化细胞等生物效应。近些年的研究证实,1-磷酸鞘氨醇及其信号通路对于支气管哮喘的发生、发展起到了非常重要的作用。这将或许为支气管哮喘的治疗提供一个新途径,本文主要就1-磷酸鞘氨醇与支气管哮喘的关系作一综述。     

MicroRNA与支气管哮喘

MicroRNA是一类单链小分子RNA,在各个物种间具有高度的保守性。MicroRNA的主要功能是在转录后水平调节相关基因表达,进而对机体生长、发育以及疾病发生过程进行调控。支气管哮喘是一种常见的慢性气道炎症性疾病,其特征是反复发作性喘息、可逆的气道梗阻和气道重塑。近年来,MicroRNA在支气管哮喘发病过程中的调控机制日益引起研究者们的重视。本文就近年来MicroRNA在支气管哮喘发病机制方面的研究进行综述。     

Reflexology and bronchial asthma

Many asthma patients seek alternative or adjunctive therapies. One such modality is reflexology, whereby finger pressure is applied to certain parts of the body. The aim of the study was to examine the popular claim that reflexology treatment benefits bronchial asthma. Ten weeks of active or simulated (placebo) reflexology given by an experienced reflexologist, were compared in an otherwise blind, controlled trial of 20+20 outpatients with asthma. Objective lung function tests (peak flow morning and evening, and weekly spirometry at the clinic) did not change. Subjective scores (describing symptoms, beta2-inhalations and quality of life) and also bronchial sensitivity to histamine improved on both regimens, but no differences were found between groups receiving active or placebo reflexology. However, a trend in favour of reflexology became significant when a supplementary analysis of symptom diaries was carried out. It was accompanied by a significant pattern compatible with subconscious unblinding, in that patients tended to guess which treatment they had been receiving. No evidence was found that reflexology has a specific effect on asthma beyond placebo influence.     

MicroRNA与支气管哮喘

MicroRNA是一类单链小分子RNA,在各个物种间具有高度的保守性.MicroRNA的主要功能是在转录后水平调节相关基因表达,进而对机体生长、发育以及疾病发生过程进行调控.支气管哮喘是一种常见的慢性气道炎症性疾病,其特征是反复发作性喘息、可逆的气道梗阻和气道重塑.近年来,MicroRNA在支气管哮喘发病过程中的调控机制日益引起研究者们的重视.本文就近年来MicroRNA在支气管哮喘发病机制方面的研究进行综述.     

循环纤维细胞与支气管哮喘

支气管哮喘（简称哮喘）气道重塑是慢性哮喘不可逆性气流受限的重要原因,是由多种细胞共同作用最终导致气道结构异常的过程,目前机制尚未完全明确。近年来,越来越多的研究结果表明,循环纤维细胞在哮喘的气道重塑中发挥着重要作用。本文就循环纤维细胞的基本生物学特性以及其参与哮喘气道重塑的研究现状及进展作一综述。     

Drug-induced bronchial asthma

In any case of acute bronchoconstriction the possibility of an adverse reaction to a drug should be considered. In many of such side reactions no allergic mechanism can be detected. Therefore, they are included into the category of pseudoallergic reactions (PAR). The clinically most important form of drug-induced bronchial asthma, analgesics asthma, belongs to this PAR group. A further risk for asthmatics are intravenous applications of contrast-media for roentgenography which in about 15% induce a severe, sometimes life-threatening pseudo-allergic adverse reaction. In asthmatics, the application of any beta-receptor blocking agents and also the use of parasympathicotonic eye drops for treatment of glaucoma are contraindicated. Paradoxical bronchial constriction following application of antiasthmatics are preponderantly caused by locally irritative actions, less frequently by genuine allergic phenomena or additive intolerance. The most reliable prophylaxis against drug-induced bronchial asthma consists in strong avoidance of all derivatives possibly capable to trigger any intolerance. A respective warning should entered into the emergency passport.     

Air pollution

Despite progress in improving ambient air quality and reducing personal exposures to air pollutants in indoor settings, population exposures to air pollutants remain widespread and are an important public health concern. Many air pollutants are associated with adverse health effects; the most serious include development and exacerbation of asthma, loss of lung function, impaired neurobehavioral development, and death. These outcomes are the focus of current health effects research on environmental tobacco smoke and radon in indoor settings, and lead, ozone, and particulate matter outdoors. Advances in methods to measure exposures to specific pollutants and the identification of markers of individual susceptibility are providing improved data on the relation of exposure and disease, and, in turn, will improve efforts to protect public health.     

HSP60与支气管哮喘相关性的探讨

支气管哮喘(简称哮喘)是以气道高反应为特征的慢性气道炎症.目前哮喘的治疗局限在控制临床症状上,因此应用更广泛的治疗手段亟待大家去探索.CD4+T淋巴细胞在哮喘的气道炎症、黏液产生、气道高反应性中起了极其重要的作用.近年来有研究发现热休克蛋白60(heat shock protein 60,HSP 60)能够介导CD4+T淋巴细胞的分化,提示HSP60可能成为治疗哮喘的新靶点,尤其是重症哮喘和难治性哮喘.本文旨在就目前的关于HSP60和哮喘关系的研究作一综述.