Relationship between pulmonary test variables and asthma and wheezing: a validation of self-report of asthma

We investigated the relationship between the pulmonary test variable measurements and self-reported asthma and wheezing from a cross-sectional study conducted in Saskatchewan. Based on the responses to the questionnaire, the subjects were classified into asthmatic, wheezing, and asymptomatic groups. For both male and female subjects the mean values of forced expiratory volume in 1 s (FEV1), forced expiratory flow during the middle half of the forced vital capacity (FEF25-75), and FEV1/FVC ratio were lowest in asthmatics, followed by wheezing and asymptomatic groups, respectively. This trend was also observed in forced vital capacity (FVC) for men but not for women. After adjusting for current smoking status, the trend in the means across the three groups was statistically significant in men for FEV1 (p = 0.03), FEF25-75 (p = 0.002), and FEV1/FVC ratio (p = 0.002) and in women for FEF25-75 (p < 0.001) and FEV1/FVC ratio (p < 0.001). The differences in the adjusted means of FVC, FEV1, FEF25-75, and FEV1/FVC ratio between asymptomatic subjects and the other two groups were significant in both male and female subjects. Significant differences were also observed between asthmatics and wheezing groups in the adjusted means of FEF25-75 and FEV1/FVC ratio in male and female subjects. We conclude that the self-report of asthma has a high level of validity against the criterion of concurrently measured pulmonary test variables.     

Monogenic determinants of familial Alzheimer''s disease: presenilin-2 mutations

An industry-wide pulmonary morbidity study was undertaken to evaluate the respiratory health of employees manufacturing refractory ceramic fibers at five US sites between 1987 and 1989. Refractory ceramic fibers are man-made vitreous fibers used for high temperature insulation. Of the 753 eligible current employees, 742 provided occupational histories and also completed the American Thoracic Society respiratory symptom questionnaire; 736 also performed pulmonary function tests. Exposure to refractory ceramic fibers was characterized by classifying workers as production or nonproduction employees and calculating the duration of time spent in production employment. The risk of working in the production of refractory ceramic fibers and having one or more respiratory symptoms was estimated by adjusted odds ratios and found to be 2.9 (95 percent confidence interval 1.4-6.2) for men and 2.4 (95 percent confidence interval 1.1-5.3) for women. The effect of exposure to refractory ceramic fibers on forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), the ratio of the two (FEV1/FVC), and forced expiratory flow (liters/second) between 25 percent and 75 percent of the FVC curve (FEF(25-75)) was evaluated by multiple regression analysis using transformed values adjusted for height, by dividing by the square of each individual's height. For men, there was a significant decline in FVC for current and past smokers of 165.4 ml (p < 0.01) and 155.5 ml (p = 0.04), respectively, per 10 years of work in the production of refractory ceramic fibers. For FEV1, the decline was significant (p < 0.01) only for current smokers at 134.9 ml. For women, the decline was greater and significant for FVC among nonsmokers, who showed a decrease of 350.3 ml (p = 0.05) per 10 years of employment in the production of refractory ceramic fibers. These findings indicate that there may be important sex differences in response to occupational and/or environmental exposure.     

Comparative relationship between copper-zinc plasma concentrations and superoxide dismutase activity in camels and cows

OBJECTIVE: To further define the asthma-like syndrome seen in swine confinement workers. DESIGN: A cross-sectional study was performed at a swine confinement facility in rural Nebraska and at the University of Nebraska Medical Center, Omaha, Nebraska. Participants: 24 swine confinement workers and 14 urban normal control subjects. All subjects completed a questionnaire concerning respiratory complaints. We performed hypertonic saline challenges on the swine confinement workers and control subjects in order to induce expectoration of sputum. Cell counts and cell differentials were determined in the induced sputum samples. Nasal, mean, and peak exhaled nitric oxide was measured in both groups. Spirometry was also done. RESULTS: Swine confinement workers were significantly more likely to report wheezing, cough, and sinusitis symptoms than controls (p = .003). Macrophages were significantly elevated in the induced sputum samples of the swine confinement workers vs the control subjects (0.59 macrophages/mL +/- 0.1 SEM vs 0.36 +/- .16; p = .006), while there was no difference in numbers of neutrophils. No eosinophils were observed. A small elevation in mean exhaled nitric oxide was seen in the swine confinement workers compared to normal controls (11.7 ppb +/- 0.6 SEM vs 10.2 +/- 1.6; p = 0.023). Spirometry values did not differ statistically between swine confinement workers and the control group. CONCLUSIONS: Swine confinement workers have signs and symptoms of lower respiratory tract inflammation when studied using induced sputum and exhaled nitric oxide. Findings in the swine confinement workers differ from those in asthmatics and chronic bronchitis.     

Relationship between lung inflammation, changes in lung function and severity of exposure in victims of the Bhopal tragedy

The world's worst chemical industrial disaster, which occurred at Bhopal on 2-3 December, 1984, resulted in considerable respiratory morbidity in the exposed population. Therefore, a study was planned to evaluate the relationship between lower respiratory tract inflammation, lung function and severity of exposure. Sixty patients exposed to methyl isocyanate and presenting with respiratory symptoms were studied using bronchoalveolar lavage (BAL) 1-7 yrs after the accident. Pulmonary function tests included forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). An index of severity of exposure was derived retrospectively on the basis of the acute symptoms in the victims themselves or the occurrence of death among their family members. Total lung inflammatory cells (p < 0.01) and absolute numbers of macrophages (p = 0.01) and lymphocytes (p < 0.05) increased as severity of exposure increased. FEV1/FVC % (p = 0.05) was also significantly lower as severity of exposure increased. Moderately exposed subjects had significantly lower FEV1/FVC % (p < 0.05) compared to those mildly exposed. In nonsmokers, BAL neutrophils, both percentage and absolute numbers, showed significant negative correlations with FEV1 % predicted (rs = -0.350, p < 0.05; and rs = -0.374, p < 0.01, respectively). Neutrophil percentage was negatively correlated with FEV1/FVC % (rs = -0.378; p < 0.01). Absolute lymphocytes had significant negative correlations with FVC % pred (rs = -0.318; p < 0.05). Macrophages had significant positive correlations with FVC % pred (rs = 0.322; p < 0.05) and FEV1 % pred (rs = 0.433; p < 0.01). Radiographic abnormalities (International Labour Organization (ILO) classification) were associated with decline in FEV1 % pred (p < 0.05). This study suggests that pulmonary function abnormalities occur in gas-exposed subjects as a consequence of an abnormal accumulation of lung inflammatory cells (lymphocytes and neutrophils), and that the intensity of lung inflammation and reduction in pulmonary function are greater in severely exposed subjects. As it has been observed that decline in pulmonary function is associated with radiographic abnormalities, there is a suggestion that injury following toxic gas exposure can lead to irreversible lung damage.     

Respiratory findings in workers employed in the brick-manufacturing industry

We studied 233 male workers employed in two brick-manufacturing plants and 149 matched control workers. The mean age of the brick workers was 35 years, with a mean duration of employment in this industry of 16 years. The prevalence of chronic respiratory symptoms as well as acute symptoms during the work shift were recorded. Lung function was measured on Monday during the work shift by recording maximum expiratory flow-volume (MEFV) curves, from which the forced vital capacity (FVC), the one-second forced expiratory volume (FEV1) and flow rates at 50% and the last 75% of the FVC (FEF50, FEF75) were measured. The results of periodic chest roentgenograms were reviewed. There was a significantly higher prevalence of chronic cough (31.8%), chronic phlegm (26.2%), and chest tightness (24.0%) in exposed workers, compared with control workers (20.1%; 18.1%; 0%) (P < 0.05). This increased symptom frequency was also documented among nonsmokers studied by age and by length of employment, suggesting a work-related effect. Among work shift-related symptoms, high prevalences were noted for upper respiratory tract symptoms (e.g., dry throat, eye irritation, throat irritation). The measured FVC and FEV1 were significantly lower than predicted for brick workers and suggested a restrictive pattern. The mean FVC (as a percent of predicted) was 78.1% and FEV1 was 88.1%. The FEF50 and FEF25 were not significantly decreased. A multiple regression analysis with age, exposure, and smoking as predictors and lung function parameters as response variables showed a significant effect between exposure and FVC. Significant chest roentgenographic abnormalities were not documented. These findings of a restrictive lung function pattern in brick workers with normal chest roentgenograms may suggest early interstitial disease. Additionally, a bronchitic component, as suggested by the respiratory symptoms, may also be present.     

Ambulatory patient-activated arrhythmia monitoring: comparison of a new wrist-applied monitor with a conventional precordial device

Sensitivity of forced expiratory flow between 25% and 75% of the vital capacity (FEF25-75) in detecting airway obstruction was investigated in 14 children with mild-moderate asthma, allergic to house dust mites, while at high altitude (1756 m). Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEF25-75, and peak expiratory flow (PEF) were measured every 2 weeks for 12 weeks (total, 84 measurements). The presence or absence of wheezing at the chest auscultation was ascertained before each test. During the study period, a significant improvement of both mean (SD) FEF25-75 [61 (12)% vs. 68 (11)% of the predicted value, p = 0.005] and PEF [95 (16)% vs. 103 (13)%, p = 0.002] was observed. FEV1 changed only marginally [82 (7)% vs. 86 (6)%, p = 0.05]. Wheezing was present on 12/84 occasions. Wheezing was associated with abnormal FEF25-75 values on most occasions but not with abnormal FEV1 or PEF. FEF25-75 was decreased on 51% of days in which wheezing was absent. FEV1 and PEF were, respectively, normal in 69% (p < 0.0001) and 92% (p < 0.0001) of measurements in which FEF25-75 was abnormal. These results suggest that FEF25-75 may be considered a good indicator of airflow obstruction and a sensitive marker of respiratory improvement in asthmatic children during reduced antigen exposure.     

Antioxidant supplementation and respiratory functions among workers exposed to high levels of ozone

Ozone exposure has been related to adverse respiratory effects, in particular to lung function decrements. Antioxidant vitamins are free-radical scavengers and could have a protective effect against photo-oxidant exposure. To evaluate whether acute effects of ozone on lung functions could be attenuated by antioxidant vitamin supplementation, we conducted a randomized trial using a double-blind crossover design. Street workers (n = 47) of Mexico City were randomly assigned to take daily a supplement (75 mg vitamin E, 650 mg vitamin C, 15 mg beta carotene) or a placebo and were followed from March to August 1996. Pulmonary function tests were done twice a week at the end of the workday. During the follow-up, the mean 1-h maximum ozone level was 123 ppb (SD = 40). During the first phase, ozone levels were inversely associated with FVC (beta = -1.60 ml/ppb), FEV1 (beta = -2.11 ml/ppb), and FEF25-75 (beta = -4.92 ml/ppb) (p < 0.05) in the placebo group but not in the supplement group. The difference between the two groups was significant for FVC, FEV1, and FEF25-75 (p < 0.01). During the second phase, similar results were observed, but the lung function decrements in the placebo group were smaller, suggesting that the supplementation may have had a residual protective effect on the lung. These results need to be confirmed in larger supplementation studies.     

Nitrile butyl rubber glove permeation of pesticide formulations containing 2,4-D-amine, DDT, DEET, and Diazinon

Previous studies have suggested that excessive losses of FVC and FEV1 were occurring in Vermont granite workers despite the fact that mean quartz levels existing in the industry were below the current OSHA standard of 100 micrograms/m3. We reexamined these losses in granite workers over an 8-year period, testing the workforce biennially from 1979 to 1987. All workers, including stone shed, quarry, and office, were offered forced spirometry using a 10-L water-sealed spirometer (Collins). In the peak year of participation (1983), 887 workers out of a total of approximately 1,400 were tested. Estimates of longitudinal loss were based on 711 workers who participated in at least three of the surveys. The mean age of this group was 42.9 years, and the mean years employed was 19.3 years; 21.4 percent were non-smokers (NS), 34.2 percent were ex-smokers (ES), and 44.4 percent were current smokers (CS). Average annual losses of FVC were 0.018 (SD = 0.056) L (CS, 0.025 L; NS, 0.006 L: and ES, 0.016 L). Average annual losses of FEV1 were 0.030 (SD = 0.041) L (CS, 0.038 L; NS, 0.020 L; and ES, 0.027 L). Analysis of covariance indicated that losses were related to the initial values for FVC or FEV1, height, age, and smoking status. After adjusting for these variables, the losses of both FVC and FEV1 were not correlated with years employed in the granite industry. No significant differences existed in the loss of FVC or FEV1 in categories of workers exposed to different levels of granite dust, eg, office, quarry, and stone shed workers. The annual losses of pulmonary function were significantly smaller than those estimated previously, which were 0.070 to .080 L in FVC, and 0.050-0.070 L in FEV1. We conclude that dust levels in the Vermont granite industry, which have been in conformance with OSHA permissible exposure limits, do not accelerate pulmonary function loss.     

Evaluation of heliox in children hospitalized with acute severe asthma. A randomized crossover trial

STUDY OBJECTIVE: To determine whether breathing a blend of 70% helium:30% oxygen (heliox) would improve pulmonary function, decrease clinical score, and improve the sensation of dyspnea in children hospitalized with acute severe asthma. DESIGN: Prospective, randomized, double-blind, crossover study. SETTING: The inpatient pediatric service of a military, tertiary care, teaching hospital. PATIENTS: Children 5 to 18 years who required hospital admission for treatment of acute asthma. INTERVENTIONS: All patients received 5 mg of nebulized albuterol every 1 to 4 h, with a dose given within 30 min of the start of the study, and IV administered methylprednisolone. Patients breathed heliox and a 30% oxygen-enriched air mixture for 15 min each in random order. MEASUREMENTS AND RESULTS: Clinical score, dyspnea score, oxygen saturation, heart rate, and respiratory rate, followed by FVC, FEV1, peak expiratory flow rate (PEFR), and, mean midexpiratory flow rate (FEF25-75) were obtained at study entry, 15 min after breathing the first gas mixture (heliox or air per randomization), 15 min after breathing the second mixture, and again 15 min after stopping the second gas mixture (study end values). Eleven children were enrolled, and all completed the study. There were no significant differences between study entry and study end spirometric values. Using the paired t test, we found no significant differences between mean values (SD) of FEV1 and FVC obtained while breathing heliox vs air; FEV1-heliox, 53% (18%) of the predicted value; FEV1-air, 52% (16%) of the predicted value (p = 0.36); FVC-heliox, 69% (22%) of the predicted value; and FVC-air, 70% (21%) of the predicted value (p = 0.50). The differences in values for PEFSR and FEF25-75 while breathing heliox vs air were small but did reach statistical significance in favor of heliox: PEFR-heliox, 56% (20%) of the predicted value; PEFR-air, 50% (16%) of the predicted value (p = 0.04); FEF25-75-heliox, 32% (13%) of the predicted value; and FEF25-75-heliox, 29% (11%) of the predicted value (p = 0.006). Heliox had no effect on either clinical or dyspnea scores. CONCLUSION: The short-term inhalation of heliox did not benefit this group of children hospitalized with acute, severe asthma.     

Should sperm donors be paid? A survey of the attitudes of the general public

Human immunodeficiency virus (HIV) infection has been associated with a wide spectrum of pulmonary disease. We report three HIV-seropositive patients with rapidly worsening airway obstruction associated with bronchiectasis. All subjects (age range 33-39 yrs) were cigarette smokers. Two had previously used intravenous drugs. The CD4 lymphocyte count ranged 40-250 cells x mm(-3). All individuals had complained of increasing dyspnoea for 3-6 months. Within 1 yr, they all developed severe airway obstruction with a decrease in both forced expiratory volume in one second (FEV1) and ratio of FEV1 to forced vital capacity (FEV1/FVC) to less than 60% of predicted value, and a decrease in mean forced expiratory flow at 25-75% of the forced vital capacity (FEF25-75) to less than 35% of predicted value. Computed tomography of the chest disclosed bilateral dilated and thickened bronchi. No classical causes of genetic or acquired bronchiectasis were identified in our patients. Recurrent bacterial bronchitis occurred in the follow-up period of the three patients. In conclusion, unusually rapid airway obstruction associated with bronchiectasis should be added to the wide spectrum of respiratory complications of human immunodeficiency virus infection.     

Determinants of survival in pulmonary Langerhans' cell granulomatosis (histiocytosis X). Groupe d'Etude en Pathologie Interstitielle de la Société de Pathologie Thoracique du Nord

The course of pulmonary Langerhans' cell granulomatosis (pulmonary LCG) is variable, difficult to predict and ranges from spontaneous remission to progressive respiratory insufficiency and death. To identify the determinants of survival, we performed a survival analysis on 45 patients with pulmonary LCG. The patients were aged 28 +/- 10 yrs (mean +/- SD) (range 12-62 yrs), 32 males and 13 females, almost exclusively current smokers (96%), and 78% presented symptoms at the time of diagnosis. Diagnosis was made by lung biopsy in 25 patients (56%) and by bronchoalveolar lavage (BAL) analysis in 20 patients (44%). The patients were followed for a median period of 6 yrs (range 1-29 yrs) after the diagnosis. During the period of observation, 33 (73%) patients survived (median follow-up period = 5.8 yrs; range, 1-29 yrs) and 12 (27%) died or underwent lung transplantation (median follow-up period = 8.4 yrs; range 1.4 - 16.1 yrs). The median survival was approximately 13 years. A univariate analysis demonstrated that diminished survival was significantly associated with: an older age at diagnosis (p = 0.0001); a lower forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio at diagnosis (p = 0.005); a higher residual volume/total lung volume (RV/TLC) ratio at diagnosis (p = 0.02); and steroid therapy during follow-up (p = 0.03). Additional predictive information on mortality was: age > 26 yrs (sensitivity 83%, specificity 64%); FEV1/FVC ratio < 0.66 (sensitivity 75%, specificity 86%); and a RV/TLC ratio > 0.33 (sensitivity 75%, specificity 63%). In multivariate Cox analysis, the combination of factors which gave the best prognostic value was FEV1/FVC ratio and age (p < 0.01). The present findings suggest that adverse prognosis factors at diagnosis in pulmonary Langerhans' cell granulomatosis include older age, lower FEV1/FVC ratio and higher RV/TLC ratio, with additional predictive information on mortality if aged > 26 yrs, FEV1/FVC ratio < 0.66, and RV/TLC ratio > 0.33.     

Albendazole for treatment and prophylaxis of microsporidiosis due to Encephalitozoon intestinalis in patients with AIDS: a randomized double-blind controlled trial

STUDY OBJECTIVES: To determine whether obese, apparently healthy individuals experience dyspnea at rest and, if so, whether their pulmonary function test (PFT) profile and maximal respiratory pressures are different from obese, healthy subjects without dyspnea. DESIGN: Prospective, open. SETTING: Pulmonary function test laboratory, Veterans Administration Medical Center. PATIENTS: Twenty-three obese male subjects (each with a body mass index [BMI] of > 28 kg/m2) with an FEV1 level and an FEV1/FVC ratio > or = 80% of predicted and no coexisting conditions. Fifteen complained of dyspnea, where eight denied having it, at rest. MEASUREMENTS AND RESULTS: Standard PFT parameters and maximum static inspiratory (P(Imax)) and expiratory (P(Emax)) mouth pressures were determined. Subjects with dyspnea had similar age and height but larger body weight (113.9+/-5.0 vs 97.4+/-2.6 kg, p = 0.03) and BMI (37.4+/-1.6 vs 31.8+/-0.7 kg/m2, p = 0.02) than subjects without dyspnea, and a greater number of them were current or previous smokers. Forced expiratory flow at 75% vital capacity (54.9+/-6 vs 75.5+/-7% predicted, p = 0.05), maximum voluntary ventilation (MVV; 90.2+/-3.8 vs 107.8+/-9.3% predicted, p = 0.05), and P(Emax) (77+/-2 vs 97.8% predicted, p = 0.007) were significantly reduced in the group of subjects with dyspnea. Large airway function (FVC, FEV1, and FEV1/FVC ratio), lung volumes, and gas exchange parameters were similar between the two groups. CONCLUSIONS: Some obese, but otherwise healthy, individuals experience dyspnea at rest. Reduced P(Emax) and MVV combined with greater body mass and peripheral airway disease are most likely responsible for the sensation of dyspnea in these individuals.     

Pulmonary function, smoking habits, and high resolution computed tomography (HRCT) early abnormalities of lung and pleural fibrosis in shipyard workers exposed to asbestos

To evaluate the presence of asbestos-related pleural and parenchymal abnormalities and their correlation with pulmonary function and smoking habits, 119 asbestos-exposed asymptomatic workers (mean age, 46.2 years; mean duration of asbestos exposure, 8.6 years; mean latency time, 21.6 years) with normal standard P.A chest radiographs were submitted to HRCT, CO-diffusing capacity and pulmonary function tests. HRCT scans were normal only in 31 (26%) examined workers; 31 (26%) subjects showed both pleural and parenchymal involvement, and 50 (42%) and seven (6%) had exclusively pleural and parenchymal abnormalities, respectively. Based on CO-diffusing capacity and pulmonary function tests, no significant difference was demonstrated between workers with pleural lesions and subjects with normal pleura; however, lower values of FVC were observed in the nonsmoking workers with parenchymal abnormalities in comparison with nonsmoking subjects with normal parenchyma (78.2 vs. 89.7% of predicted values; p = 0.03 by student's two-tailed t test), and lower values of FEV1/FVC in the smokers with parenchymal lesions with respect to smokers with normal parenchyma (93.7 vs. 100.2% of predicted values; p = 0.005 by students' two-tailed t test). In conclusion, our results demonstrate that HRCT may detect early parenchymal abnormalities which correlate with exposure to asbestos and respiratory function impairment, including a reduction in obstructive indices in smokers occupationally exposed to asbestos, without any clinically evident disease.     

Eosinophil cationic protein in the asthmatic infant: correlation with the clinic and pulmonary function

PATIENTS AND METHODS: Serum eosinophil cationic protein (ECP) was measured in 99 chronic asthmatic patients (51 males and 48 females) with a mean age of 10.59 years and correlated with the number of eosinophils, lung function, symptoms in the last 6 months and clinical scoring (that reflecting the clinical situation during the last 15 days). RESULTS: Serum ECP showed a significant correlation with the total number of eosinophils (p < 0.001, R = 0.44), clinical scoring (p < 0.05, R = 0.26), number of inhaled beta 2-agonist doses needed in the last 15 days (p < 0.05, R = 0.26), forced expiratory volume during 1 second (FEV1; p < 0.01, R = -0.27), forced vital capacity (FVC; p < 0.05, R = -0.23), maximal mid-expiratory flow (FEF25-27; p < 0.001, R = -0.37). However, there was no significant correlation between the total number of eosinophils and the clinical situation of the children or the FEV1, but we found a significant correlation with the FEF25-27. Patients with ECP < 20 had better results on lung function tests than patients with ECP > 20 (FEV1: 108.89 +/- 17.7 vs 100.5 +/- 22 (p < 0.05), FEF25-27: 93.81 +/- 24.4 vs 75.21 +/- 24.5 (p < 0.001). CONCLUSIONS: The findings of this study suggest that the ECP level is a good marker of the situation of asthma in childhood. The levels of ECP will probably be able to help us to evaluate the degree of bronchial inflammation that neither the clinical state nor the lung function define completely.     

Respiratory health of California rice farmers

Rice farmers are occupationally exposed to agents that may affect respiratory health, including inorganic dusts and smoke from burning of agricultural waste. To assess respiratory health of this occupational group, we conducted a cross-sectional study, including a self-administered health and work questionnaire, spirometry, and chest radiography among 464 male California rice farmers. Mean age +/- SD was 48.3 +/- 15.2 yr; mean duration of rice farming was 25.7 +/- 14.3 yr. Prevalences for respiratory symptoms were: chronic bronchitis (6.3%), physician-diagnosed asthma (7.1%), and persistent wheeze (8.8%). Chronic cough was reported by 7.1% of respondents and was associated with reported hours per year burning rice stubble. Mean FEV1 and FVC were at expected values. FEV1 was inversely associated with years working in rice storage and use of heated rice dryers. Mean FEF25-75 was 93% of expected and was inversely associated with rice storage activities involving unheated rice driers. ILO profusion scores > or = 1/0 for small irregular opacities were seen in 18 (10.1%) of 178 chest radiographs. Study findings suggest increased asthma prevalence among California rice farmers. Radiologic findings consistent with dust or fiber exposure were increased compared with those of the general population, although no associations with specific farming activities were identified.     

The pulmonary performance and airway reactivity in acute and chronic fascioliasis before and after triclabendazole treatment

The pulmonary performance and airway reactivity were evaluated in 16 acute and 12 chronic fascioliasis patients before and after treatment with triclabendazole in a trial to clarify some underlying pulmonary changes which can explain the chest symptomatology that may accompany this intestinal fluke. Before treatment, the maximum voluntary ventilation was impaired in the acute and chronic cases. In the acute stage, the affection was in the small airways (as denoted by lower values of FEF75% compared to control), while in the chronic stage, the impairment was more generalized including not only the small and large airways (as shown by diminished FVC, FEV1, FEFmax, FEF25%, FEF50% and FEF75%) but also, the upper airway (as noticed by lower values of FIVC and FIF50% compared to the corresponding control values). By individual analysis of the dose response slopes (DRS), 37.5% of acute and 33.3% of chronic cases had bronchial hyperactivity. After triclabendazole treatment and cure of the patients, most of the pulmonary flow rates improved significantly compared to the pre-treatment values. Moreover, all cases regained normal bronchial reactivity and the DRS diminished significantly than during fascioliasis infection. It is concluded that, although the fluke doesn't have a cycle in the lung, yet it may have an impact on the pulmonary performance and airway reactivity which subsides greatly after treatment with triclabendazole.     

Follow-up study of changes in respiratory function in the same workers after an additional 6 years of exposure to pollutants in the rubber industry

Follow-up study of respiratory function was carried out in a group of 311 male workers employed in one rubber industry. The prevalence of respiratory symptoms and ventilatory capacity were recorded over te period of six years. Lung function was measured by recording maximum expiratory flow-volume (MEFV) curves on which forced vital capacity (FVC), one-second forced expiratory volume (FEVI) and flow rates at 50% and the last 25% of the vital capacity (FEF50, FEF25) were read. The prevalence of all chronic respiratory symptoms was higher during the follow-up study although not statistically significant (p > 0.05). During both studies smokers had significantly higher prevalence of chronic cough, chronic phlegm and chronic bronchitis than nonsmokers (p < 0.05 or < 0.025). Measured values of ventilatory capacity were significantly lower than predicted normal values during both studies (p < 0.01). Percentage of predicted values were lower during the follow-up study in comparison to that during the initial study. The mean lowest percentages were obtained for FEF25 (initial study: 77.4%; follow-up study: 70.5%). Smokers had larger mean annual decrease of FVC: 0.073 L; FEVI: 0.063 L; FEF50: 0.100 L/s; FEF25: 0.085 L/s than nonsmokers (FVC: 0.063 L; FEVI: 0.058 L; FEF50: 0.083 L/s; FEF25: 0.058 L/s). Workers exposed for more than 10 years had larger mean annual decrease of ventilatory capacity tests than hose with shorter exposure. Our data indicate that exposure to noxious agents in rubber industry may be responsible for the development of chronic respiratory symptoms and chronic lung function changes.     

Spirometry in life-long non-smoking, healthy Chinese women in Taiwan

To establish the spirometric values for normal, healthy Chinese women in Taiwan, the spirometry of 506 life-long non-smoking, healthy Chinese women was examined, including 140 subjects over the age of 60 years. Significant correlations among age, height and forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC%, peak expiratory flow (PEF), Vmax75, Vmax50, Vmax25 were found. However, there were no significant correlations between age and FEV1/FVC%, nor age and Vmax25 in the elderly group. FEV1 (FEV1*) and FVC (FVC*) were standardized to the overall mean height for elderly women using Cole's formula. The decline in FEV1* and FVC* with age were observed. The predicted value for the average 70-year-old woman with a height of 1.5 m derived from the present study is compared with those from other surveys of the elderly. The values from the present study are somewhat higher than the values from the Hong Kong study. The authors believe the fact that all of the present subjects were life-long non-smokers might explain the differences.     

Methods development for epidemiologic investigations of the health effects of prolonged ozone exposure. Part I: Variability of pulmonary function measures

The acute and subacute effects of ambient concentrations of ozone on lung function have been studied extensively in a variety of settings. Such studies generally have focused on measures of function that reflect either lung volumes or flows that are influenced by the physiology of large and small airways (e.g., forced expiratory volume in one second [FEV1). Data from animal studies suggest that the effects of prolonged exposure to elevated ambient concentrations of ozone result in abnormalities in the centriacinar region of the lung; and dosimetry models for humans predict that long-term exposure to ozone could impact the same areas of the human lung. However, alterations in structure at this level of the lung are not well reflected by measuring FEV1 until substantial structural changes have occurred. Measures of the lung function that reflect the functional mechanics of airways smaller than 2 mm in diameter are considered to be more relevant. At least one epidemiologic study has provided evidence that small-airway functions may be relevant to effects of prolonged exposure to environments with high concentrations of oxidants. A considerable body of physiologic data has established that flow rates measured during the terminal portion of a maximum expiratory flow-volume (MEFV) curve are largely governed by airways smaller than 2 mm in diameter A similar interpretation has been given to changes in the slope of phase III (delta N2) of the single-breath nitrogen washout (SBNW) curve. Despite the attractiveness of these measures in relation to airway physiology, some data suggest that measurements of flow via the terminal portions of MEFV and SBNW curves have much greater within-subject variability than forced vital capacity (FVC and FEV1. The present study was undertaken as part of a larger feasibility study to develop methods to study the effects of prolonged exposure to elevated ambient ozone levels on lung function in adolescents. A convenience sample of 239 freshmen (ages 16-20 years) entering the University of California, Berkeley were recruited to participate in this protocol. All were lifelong residents of the San Francisco Bay Area or the Los Angeles Basin. Subjects were studied on two occasions five to seven days apart. At each test session, subjects performed up to eight forced expiratory maneuvers to produce three acceptable and reproducible MEFV curves by modified American Thoracic Society criteria. Tests of SBNW were then performed on the basis of detailed criteria for validity and reproducibility. Eight attempts to generate three curves were allowed. The delta N2 was obtained by a least-squares regression of nitrogen concentrations between the 750-mL and 1750-mL volume points. Instantaneous flow at 75% of expired volume (FEF75%), average flow between the 25% and 75% volume points (FEF25%-75%), and delta N2 were the principal outcomes. Variance components were estimated with a nested random effects model with adjustments for important covariates. The average within-subject coefficients of variation (+/-SD of distribution of means) for male subjects were: FEV1 1.2 (+/-0.8); FEF25%-75% 3.2 (+/-2.3); FEF75% 5.8 (+/-5.0); and delta N2 17.9 (+/-12.3); for female subjects they were: FEV1 1.4 (+/-0.9); FEF25%-75% 3.0 (+/-2.2); FEF75% 6.2 (+/-5.2); and delta N2 19.9 (+/-17.0). The variance attributed to test session was less than 1% for all measures. The percentages of variance due to within-subject variation for each measure (adjusted for sex, area of residence, ethnicity, and height) were: FVC 3.6%; FEV1 3.0%; FEF25%-75% 5.2%; FEF75% 8.9%; and delta N2 23.9%. Of all subjects tested, 234 (97.9%) could provide at least two acceptable MEFV curves, but only 218 (91.2%) could provide at least two acceptable SBNW curves. The results were unchanged by recent history of acute, respiratory illness.(ABSTRACT TRUNCATED)     

Analysis of ventilation parameters before and after fiber optic bronchoscopy in patients with atopic bronchial asthma and chronic obstructive pulmonary diseases

Bronchial asthma and chronic bronchitis in a stable period of the disease could be an indication for diagnostic bronchofiberoscopy. The aim of the authors of this article is to assess whether bronchoscopy may be safely used either as diagnostic or therapeutic procedure. 21 patients (age 33-46), 13 with atopic bronchial asthma and 8 with COPD took part in this study. The measurements were carried out one day before and 3 hours after the bronchoscopy. The following parameters: Forced Vital Capacity (FVC), Forced Expiratory Volume (FEV1), Forced Expiratory Flow (FEF25, FEF50, FEF75) and Resistance of Airways (R aw) were taken into consideration. It was shown that bronchofiberoscopy could be performed safely in these patients and did not lead to woersing ventilation parameters. Bronchospasm was not observed during the study. Moreover the increase in FEF50, FEF75 and R aw were observed. This significant decrease of amount of bronchial discharge could serve as an explanation of this phenomenon.