Studies of the familial aggregation of chronic bronchitis and obstructive airways disease

The familial aggregation of chronic bronchitis and obstructive airways disease was investigated in a propositus population of 430 persons aged 45-54 years and 1340 of their first (1 degree), second (2degrees) and third (3 degrees ) order relatives. All subjects were screened in their homes using a modified British MRC respiratory disease questionnaire and a portable spirometer. 1 degree relatives of propositi with either chronic bronchitis or obstructive airways disease demonstrated up to a two-fold excess prevalence of chronic bronchitis when compared to 1 degree relatives of non-affected propositi. This excess prevalence of chronic bronchitis was independent of sex, cigarette smoking patterns, respiratory illness history, residence in a common household, geographical distribution within the study community and the presence of alpha1-antitrypsin Pi variants. The prevalence of chronic bronchitis in 1 degree relatives of diseased propositi was also greater than in 2 degrees relatives of diseased propositi, in whom the prevalence approximated that of the general population.     

气溶胶粒子在呼吸系统内沉降规律的数值模拟

目的：研究可吸入气溶胶粒子在人体气管、支气管内的沉积规律。方法：建立基于Weibel模型的G0～G3级气管、支气管模型,在呼吸强度为15、30和60 L/min时,设定不同的出口边界条件,模拟气溶胶粒子不同密度和不同粒子直径时的颗粒沉积情况。结果：不同的边界条件下,流场变化不大,对粒子的沉积影响不大。相对于粒子密度,粒子的直径和呼吸强度对沉积规律的影响更大。结论：该研究对于开发新的气溶胶吸入治疗药物和新的气溶胶吸入治疗装置具有一定的借鉴意义,为进一步研究气溶胶浓度和失能剂起效的血药浓度的对应关系提供了一定的依据。     

氨溴索联合沙丁胺醇雾化治疗慢性支气管炎疗效观察

目的:探讨氨溴索联合沙丁胺醇雾化治疗慢性支气管炎(含慢性阻塞性肺疾病)的疗效.方法:选取慢性支气管炎急性发作患者116例作为研究对象,随机分为观察组和对照组.在一般常规治疗的基础上,对照组给予吸入用硫酸沙丁胺醇溶液雾化(氧驱动)治疗,观察组则给予盐酸氨溴索注射液加吸入用硫酸沙丁胺醇溶液联合雾化(氧驱动)治疗,对比分析两组的疗效.结果:观察组患者临床症状、FEV1、V/Q等改善情况优于对照组,差异有统计学意义(P＜0.05).结论:盐酸氨溴索联合吸入用硫酸沙丁胺醇雾化吸入治疗慢性支气管炎疗效显著,值得临床推广.     

Atopy, smoking, and chronic bronchitis.

The aim was to test the hypothesis that atopy increases the occurrence of chronic bronchitis. Relations between atopy, smoking, and chronic bronchitis were studied in farmers. The data were from two successive postal surveys and a skin prick tested subsample. The cross-sectional study consisted of 9017 farmers. Those 6899 farmers who did not have chronic bronchitis at the beginning and who continued farming were followed for three years. A sample of 150 farmers was skin-tested with 36 allergens. The prevalence of chronic bronchitis (rate per 1000), standardised for age and sex, was 41 in non-atopic non-smokers, 101 in atopic non-smokers, 106 in non-atopic smokers, and 257 in atopic smokers (effect of atopy: p less than 0.001; effect of smoking: p less than 0.001). The standardised incidence rates of chronic bronchitis (per 1000 farming years) were 14, 34, 36, and 50, respectively (atopy: p less than 0.001; smoking p less than 0.001). The relative risk of chronic bronchitis, calculated from the incidence data adjusting for the effects of age, sex, smoking or atopy by logistic regression analysis was 2.2 for atopy (95% confidence interval 1.8-2.7) and 2.3 for smoking (1.8-2.9). Only 20 farmers had chronic bronchitis in the skin-tested subjects; the results were consistent with the findings in the surveys but did not reach statistical significance for atopy. In conclusion, atopy and smoking have independent and additive effects on the occurrence of chronic bronchitis at least in dusty farming work.     

Impaction and sedimentation deposition of fibers in airways

Theoretical impaction and sedimentation deposition of fibers in a model airway have been obtained based upon Jeffery's theory of particle motion. The corresponding expressions for the equivalent diameter of fibers have also been derived. The results are compared with experimental data and other formulas available in the literature for glass fibers. It is shown that for the flow condition existing in the airways, the equivalent diameters of fibers for both impaction and sedimentation are very close to the values obtained when the fibers are oriented parallel to the flow.     

Inhalation of a radioactively labeled monodisperse aerosol in rats for the assessment of regional deposition and clearance

Unanesthesized male Sprague-Dawley rats, averaging 261 g of weight (s.d. = 9 g), were exposed to a radioactively (198Au) labeled monodisperse carnauba wax aerosol, whose AMMD was 0.54 micrometers with a sigma g of 1.1, to determined the alveolar deposition and clearance of particles. Results indicate that 74% of the initial lung burden is cleared in phase one with a T/2 of 11 hours. The remaining 26%, conventionally considered to be the alveolar deposit, is cleared with a T22 of 320 hours. Excised lungs from serial sacrifices have also been measured. The retention curve resulting form the pooled lung data per each day compared well with the curve of the whole animals counted in vivo.     

Other obstructive diseases: byssinosis, chronic bronchitis and occupational COPD and eosinophilic bronchitis

Besides occupational asthma and diseases derived from acute inhalation, other obstructive diseases also have an occupational origin. Although at present byssinosis is a rare disease in Spain, we describe its characteristics because of its historical interest amongst occupational respiratory diseases and because it is still relevant in developing countries. Chronic bronchitis can also be related to exposure at work to dust and smoke, and is often referred to as "industrial bronchitis". Historically, the relation of CPOD to occupation has been subject to controversy, but nowadays this relationship is accepted; we describe the present evidence supporting this relationship. Finally, we describe eosinophilic bronchitis without asthma, an entity that was described for the first time in 1989 and that can sometimes have an occupational origin, sharing aetiological agents with occupational asthma.     

The effect of aerosol charge on the deposition and clearance of TiO2 particles in rats

A titanium dioxide aerosol when generated by a Wright dust feed will have a higher electrostatic charge by a factor of 5.5 than one which has been discharged by a bipolar ion field produced by a 7.5 mCi ⁸⁵Kr source. The deposition of particles in the lung of rats was lower by ～21% when an aerosol discharger was used. Particle clearance from the lung alveoli was not affected by the use of the discharger.     

Quantity and size distribution of cough-generated aerosol particles produced by influenza patients during and after illness

The question of whether influenza is transmitted to a significant degree by aerosols remains controversial, in part, because little is known about the quantity and size of potentially infectious airborne particles produced by people with influenza. In this study, the size and amount of aerosol particles produced by nine subjects during coughing were measured while they had influenza and after they had recovered, using a laser aerosol particle spectrometer with a size range of 0.35 to 10 μm. Individuals with influenza produce a significantly greater volume of aerosol when ill compared with afterward (p = 0.0143). When the patients had influenza, their average cough aerosol volume was 38.3 picoliters (pL) of particles per cough (SD 43.7); after patients recovered, the average volume was 26.4 pL per cough (SD 45.6). The number of particles produced per cough was also higher when subjects had influenza (average 75,400 particles/cough, SD 97,300) compared with afterward (average 52,200, SD 98,600), although the difference did not reach statistical significance (p = 0.1042). The average number of particles expelled per cough varied widely from patient to patient, ranging from 900 to 302,200 particles/cough while subjects had influenza and 1100 to 308,600 particles/cough after recovery. When the subjects had influenza, an average of 63% of each subject's cough aerosol particle volume in the detection range was in the respirable size fraction (SD 22%), indicating that these particles could reach the alveolar region of the lungs if inhaled by another person. This enhancement in aerosol generation during illness may play an important role in influenza transmission and suggests that a better understanding of this phenomenon is needed to predict the production and dissemination of influenza-laden aerosols by people infected with this virus. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resources: a PDF file of demographic information, influenza test results, and volume and peak flow rate during each cough and a PDF file containing number and size of aerosol particles produced.].     

The relationships of aerosol deposition, lung size, and the rate of mucociliary clearance

Although the effect of deposition pattern of an inhaled aerosol upon subsequent mucociliary clearance is well recognized, the influence of lung size on the rate of clearance has not been clearly defined. To examine the relationships of lung size in terms of the forced vital capacity (FVC) and aerosol deposition pattern to the rate of mucociliary clearance, we measured lung retention of an inhaled 8-micron aerosol for 120 min using a gamma camera in 13 healthy nonsmoking volunteers. The deposition pattern of the inhaled aerosol was defined in terms of the initial skew of the distribution of retained activity within the right lung (skew) and the percent retained at 24 hr (R24). Multiple regression analysis showed that FVC was responsible for approximately 36% of the variability in bronchial retention with time, with a lesser contribution from variations in deposition pattern (skew and R24). Mucociliary clearance was significantly slower (i.e., greater bronchial retention) in male subjects than in female subjects which can probably be attributed to the differences in FVC. Variations in lung sizes as well as deposition pattern should therefore be considered when making between subject comparisons of the mucociliary clearance rate.     

Respiratory symptoms,chronic bronchitis,and ventilatory function in shipyard welders

Summary The prevalence of respiratory symptoms (by standard questionnaire) and the impairment of ventilatory function (vital capacity and FEV_1-O with a bellows spirograph) were investigated in a group of 173 shipyard welders (with more than 5 years experience) in respect to length of exposure and roentgenologic picture. A group of 100 nonwelding shipyard workers served as controls for the prevalence of symptoms. Chronic cough (22%), chronic bronchitis (20%), dyspnea (20%) and wheezing (16%) were more frequent among welders; the difference was significant for the last 2 symptoms only. In contrast, objective (physical) signs were present in equal proportion (14–12%) in both groups. A ventilatory function defect (mostly of the restrictive type) was found in 20% of the welders. The mean FEV_1-0 was significantly decreased in welders with more than 10 years exposure (P相似文献   

Quantified pathology of emphysema, pneumoconiosis, and chronic bronchitis in coal workers

ABSTRACT From a continuous series of 886 postmortem examinations on coal mine workers in New South Wales, Australia, from 1949 to 1982 and their histories the following data were obtained: age at death (886 cases), percentage of emphysema in both lungs (Heard method) (870 cases), bronchial gland wall (G-W) ratio (Reid Index) (412 cases), chest radiograph within 10 years of death (792 cases), history of work at the coal face (844 cases), history of amount of tobacco smoked (606 cases), and FEV₁ five years before death (278 cases). Linear regression analysis showed the following: (1) The severity of emphysema had a significant positive regression on years of face work independently of age at death. (2) The severity of emphysema had a significant positive regression on the severity of -ray pneumoconiosis, which was best defined in the non-smoking group and the non-bronchitic group. (3) There was a significant multiple linear regression relationship between severity of emphysema (dependent variable) and pneumoconiosis and G-W (independent variables). The ratio of standardised regression coefficients was pneumoconiosis: G-W = 3:1. (4) The severity of -ray pneumoconiosis had a significant positive regression on years of face work and a negative regression on smoking amount. (5) G-W ratio had significant positive regression on age of death and severity of emphysema but not years of face work or severity of pneumoconiosis. (6) Smoking was not correlated with severity of emphysema or G-W ratio. (7) FEV₁ (% predicted) was significantly negatively correlated with bronchitis, emphysema, and pneumoconiosis. (8) Severity of pneumoconiosis and emphysema have declined slightly but significantly over the 33 year period, but there has been no significant change in G-W ratio during 1960-82.     

Kinetics of deposition and clearance of inhaled mineral dusts during chronic exposure

New inhalation studies have been carried out with rats exposed to UICC (Union International Contre le Cancer) amosite asbestos, with the main aim of further elucidating the factors the influence the accumulation of dust in the lung during prolonged chronic exposure. The results show that, for exposure times beyond a few weeks, the lung burden rises linearly and does not level off as predicted by simple models based on ideas taken from the 1966 report of the Task Group on Lung Dynamics. Furthermore, the lung burden is found to scale directly in proportion to the exposure concentration in a way that seems to contradict the overload hypothesis stated earlier. Nevertheless, the general pattern exhibited by our results for asbestos is markedly similar to that found elsewhere for rats inhaling diesel fume, leading to the suggestion that it is general (and not specific to fibrous dust); and the hypothesis that, whereas overload of clearance can take place at high lung burdens after exposure has ceased, it is cancelled by the sustained stimulus to clearance mechanisms provided by the continuous challenge of chronic exposure. The linearity of the increase in lung burden is explained in terms of a kinetic model involving sequestration of some inhaled material to parts of the lung where it is difficult to clear. The particular sequestration model favoured is one where, the longer a particle remains in the lung without being cleared, the more likely it will be sequestrated (and therefore less likely cleared). It is believed that such ideas may eventually be useful in forming exposure-dose relations for epidemiology.     

Clinical and epidemiological diagnosis of chronic dust-induced bronchitis

A unified scheme for comprehensive interview of workers of a large metallurgic works who come in contact with occupational noxious agents that cause respiratory organs was used to select 300 workers (199 men and 101 women). They underwent a bicycle exercise test that involved the determination of forced vital capacity (FVC), forced expiratory volume within the first second (FEV1), peak expiratory air flow (PEAF), and the Tiffeneau index. Moreover, the flow/volume ratio was examined on a Flowscreen device (Erich Eger) and a test with a bronchodilator (ventoline, 200 mu/kg) was also made. The authors conducted 64 assays of eosinophilic cationic protein (ECP) and 64 assays of mucinic antigen (MA). Serum ECP and MA levels were measured by immunofluoresence and sandwich-immunofluorescence, respectively. Screening functional indices obtained from the flow/volume and bronchodilator tests are sensitive in both manifestative and latent dust-induced bronchitis so they permit identification of latent and obvious airways obstruction. ECP is a highly reliable diagnostic criterion for the asthmatic form of chronic occupational bronchitis and MA is for its inflammatory form.