Smoking and intermediate alpha1-antitrypsin deficiency and lung function in middle-aged men.

Lung function was evaluated in a representative population sample of 50-year-0ld men living in one Swedish city. Twenty-four smoking and 15 non-smoking men heterozygous for alpha1-antitrypsin deficiency--that is, with the protease-inhibitor (Pi1 phenotype MZ--were carefully matched for weight and smoking habit with Pi M controls. The pulmonary function of non-smoking Pi MZ subjects did not differ from that of non-smoking Pi M controls. In contrast, smoking heterozygotes showed a significant loss of elastic recoil, enlarged residual volumes, and increased closing capacity but no signs of obstructive ventilatory impairment. Most smoking Pi MZ individuals reported mild exertional dyspnoea.     

Simultaneous diffusion and convection in single breath lung washout

Two mathematical models of pulmonary single breath gas washout (one analytic, one numerical) are developed and their predictions compared with experimental data on human subjects. Weibel's 23 generation symmetric anatomical model is used as a guide to bronchial tree geometry. Experimental plots of nitrogen concentration versus volume expired, dead space versus breath holding time, and dead space versus tidal volume are compared with plots predicted by the models. Agreement is good. A plot of nitrogen concentration in the airways as predicted by the numerical model at different times during inhalation and exhalation of a single breath of oxygen is shown. Model predictions for changes in dead space with changes in washout gas and expiratory flow rate are discussed. Use of the analytic model for obtaining average values of the path length from mouth to alveoli in a given subject is discussed. To the extent of their agreement with experiment, the models provide a sound physical basis for the correlation of airway structure and function.     

Alpha-1-antitrypsin (protease inhibitor) phenotypes and longevity

We have tested the hypothesis that the protease inhibitor phenotypes MZ and MS are disadvantageous and reduce survival by comparing the prevalence of these phenotypes in a group of 707 very old people (hospital patients) with the prevalences reported in younger populations of blood donors. The MS and MZ phenotypes appear to be no less common among those who have survived to old age, but a highly significant difference was found in the occurrence of the M subtypes. The M1 type was more common in the elderly, and the M heterozygotes were less common than would be predicted from the reported incidence in younger groups and from the Hardy-Weinberg equilibrium. This discrepancy appeared to be smaller in subjects of Mediterranean origin than in those of British or Irish genetic background.     

Trachea and lung dimensions in nonsmoking twins: morphological and functional studies

To compare genetic and environmental factors that determine lung function and dimensions, chest radiographs and pulmonary function were measured in 17 pairs of nonsmoking twin adolescent boys (12 monozygotic pairs and 5 dizygotic pairs). Genetic factors dominated in tracheal width and lung dimensions (height, width, and apicofissural and fissurodiaphragmatic distances) at residual volume. Genetic factors also affected forced vital capacity, functional residual capacity, forced expiratory volume in 1 s, maximum expiratory flow at 25% vital capacity, and maximum flow at 50% vital capacity-to-forced vital capacity ratio. Peak expiratory flow correlated with tracheal width at residual volume. Age correlated with lung dimensions (width and depth) but not with tracheal width. These results indicate that genetic factors determine the dimensions and function of central airways, peripheral airways, and lung parenchyma in adolescent males. The effects of genetic factors on some functional measurements (airway resistance, closing volume-to-vital capacity ratio, and phase III in single-breath N2 washout) may be masked because of poor reproducibility of the tests.     

Pulmonary function changes in ozone-interaction of concentration and ventilation.

A total of 28 healthy young subjects have been exposed for 2 h to ozone (0.37-0.75 ppm) under conditions of either rest or intermittent light exercise (sufficient to increase the respiratory minute volume by a factor of 2.5). All pulmonary function tests (vital capacity, forced expiratory volume, maximum expiratory flow-volume curve, slope of phase III of alveolar nitrogen plateau) showed a significant deterioration relative to parallel control experiments. Responses were related to the dose of ozone as calculated from the product of concentration, exposure time, and respiratory minute volume during exposure, changes at 1 h averaging approximately one-half those seen at 2 h.     

Relative resistance of functional beta2-adrenoceptor-mediated smooth muscle responses to in vitro desensitization.

The effects of in vitro incubation of rat isolated left atria, pulmonary artery rings, and aortic rings with isoprenaline (10(-6) M for 6 h) were examined to compare the degree of desensitization of beta1- and beta2-adrenoceptor-mediated functional responses. The experimental protocols were carefully controlled to exclude influence from persistence of agonist in the tissues after the prolonged exposures, time-dependent changes in tissue sensitivity, and the methods of plotting the data. Concentration-response curves for isoprenaline were constructed before incubation with isoprenaline and, after washout during 1 h, a second curve was obtained. Two protocols were employed: firstly, the preincubation curve was constructed to ensure that a maximum response was obtained (>10(-6) M) and, secondly, the preincubation curve was constructed to a maximum isoprenaline concentration of 10(-6) M. Preincubation curves were corrected for time-dependent changes in sensitivity from sham-incubation control experiments. There was significant desensitization of the beta1-adrenoceptor-mediated positive inotropic responses of the left atria, using both protocols, seen as rightward shifts (dose ratios: 4.48 +/- 1.12 and 8.39 +/- 2.3) of the concentration-response curves and depression of the maximum responses (77.0 +/- 3.2 and 60.8 +/- 5.5%). In contrast, the beta2-adrenoceptor-mediated relaxations of the noradrenaline-constricted pulmonary artery and aorta did not display a significant loss of sensitivity. When the relaxation responses were plotted as a percentage of the noradrenaline-induced tone, there was no significant rightward shift of the concentration-response curves in the pulmonary artery (dose ratios: 2.82 +/- 1.33 and 2.24 +/- 0.62) or aorta (dose ratios: 1.43 +/- 0.62 and 1.31 +/- 0.27) and thus no desensitization.     

Simulation of regional lung emptying during slow and forced expirations.

Regional lung emptying was simulated by means of a bialveolar lung model. The influence of bronchial asymmetry and the vertical pleural pressure gradient was evaluated. The model suggests that 1) in vivo the influence of the pleural pressure gradient prevails over that of the bronchial asymmetry; 2) in the presence of this gradient, the shape of phases III and IV of the single-breath washout curves obtained following inspiration of a tracer gas bolus at residual volume is determined by the recoil pressure-volume curve of the lung, by the vertical displacements of the alveoli, and,, at higher flow rates, by the elastic characteristics of the airways; 3) if the pleural pressure gradient is independent of lung volume and of flow rate, the factors mentioned in 2 suffice to produce single-breath washout curves (phases III and IV) and regional vs. overall lung volume relationships corresponding to those observed in vivo; 4) the configuration of the maximal expiratory flow-volume curve is relatively insensitive to pulmonary and bronchial asymmetry, at least in healthy individuals.     

Effects of reduction mammaplasty on pulmonary function and symptoms of macromastia

A number of studies have documented subjective improvement in somatic and psychological symptoms following breast reduction surgery. Objective data demonstrating improved postoperative function have been more difficult to assess, and particularly with respect to pulmonary function, the results have been contradictory. In this prospective study, patients completed a comprehensive preoperative questionnaire modified from the American Thoracic Society Division of Lung Diseases Epidemiology Standardization Project (1978). This questionnaire noted subjective pulmonary symptoms and pulmonary medical history. In addition, subjective symptoms related to breast size, including back and neck pain and shoulder pain and grooving, and a subjective evaluation of body image, were evaluated. All subjects received preoperative pulmonary function testing, including spirometry, lung volume measurements, and measurement of peak inspiratory and expiratory flow rates and pressures. Eight weeks after breast reduction, a repeat questionnaire and pulmonary function testing were administered. Preoperative and postoperative pulmonary function values were compared using Cochran-Mantel-Haenszel tests, and correlations were tested between changes in pulmonary function test values and subjective symptom improvement. Forty-four patients underwent an average of 2228-g bilateral reduction. All of these patients had their surgical procedures preauthorized as medically necessary by their insurance carriers. All subjective parameters examined were statistically significantly improved following breast reduction (p < 0.001). Of the 17 patients with preoperative complaints of shortness of breath, all noted significant improvement following breast reduction surgery (p < 0.001). Of the objective pulmonary criteria evaluated, inspiratory capacity, peak expiratory flow rate, and maximal voluntary ventilation showed a statistically significant improvement following surgery (p < 0.05). These changes correlated with body mass index; the greater the index, the greater the change in maximal voluntary ventilation and peak expiratory flow rate. Smokers in this group had the largest change in maximal voluntary ventilation (p < 0.008). No correlation could be found between preoperative pulmonary symptoms, a single subjective symptom, or grams of breast weight reduction and changes in pulmonary function tests. The results show that pulmonary parameters, related primarily to work of breathing (inspiratory capacity, maximal voluntary ventilation, peak expiratory flow rate), were statistically improved following breast reduction surgery, and these changes correlated with body mass index.     

Ventilatory Tests and Pulmonary Conductance in Hospitalized Patients

In a series of 49 patients, including individuals with varying lung pathology and some older patients with no lung disease, the usual excellent correlation between first-second forced expiratory volume and maximum breathing capacity was found (coefficient of correlation=0.88). The first-second forced expiratory volume and maximum mid-expiratory flow rate were also seen to be closely related (coefficient of correlation=0.87). The relationship between these ventilatory tests and direct mechanical measurements of pulmonary resistance, however, was not as striking. Reduction in pulmonary compliance not due to loss or removal of pulmonary tissue did not affect the interrelationships between these tests. First-second forced expiratory volume, expressed as a percentage of the predicted vital capacity, was more closely related to the expression “% of predicted maximum breathing capacity” than the first-second forced expiratory volume, expressed as a percentage of the actual vital capacity (p<.05).     

Pulmonary function in men after oxygen breathing at 3.0 ATA for 3.5 h.

As a pulmonary component of Predictive Studies V, designed to determine O2 tolerance of multiple organs and systems in humans at 3.0-1.5 ATA, pulmonary function was evaluated at 1.0 ATA in 13 healthy men before and after O2 exposure at 3.0 ATA for 3.5 h. Measurements included flow-volume loops, spirometry, and airway resistance (Raw) (n = 12); CO diffusing capacity (n = 11); closing volumes (n = 6); and air vs. HeO2 forced vital capacity maneuvers (n = 5). Chest discomfort, cough, and dyspnea were experienced during exposure in mild degree by most subjects. Mean forced expiratory volume in 1 s (FEV1) and forced expiratory flow at 25-75% of vital capacity (FEF25-75) were significantly reduced postexposure by 5.9 and 11.8%, respectively, whereas forced vital capacity was not significantly changed. The average difference in maximum midexpiratory flow rates at 50% vital capacity on air and HeO2 was significantly reduced postexposure by 18%. Raw and CO diffusing capacity were not changed postexposure. The relatively large change in FEF25-75 compared with FEV1, the reduction in density dependence of flow, and the normal Raw postexposure are all consistent with flow limitation in peripheral airways as a major cause of the observed reduction in expiratory flow. Postexposure pulmonary function changes in one subject who convulsed at 3.0 h of exposure are compared with corresponding average changes in 12 subjects who did not convulse.     

慢性阻塞性肺疾病急性加重期患者血清SAA水平与肺功能、炎性因子的相关性及其诊断价值分析

目的:探讨慢性阻塞性肺疾病急性加重期(AECOPD)患者血清淀粉样蛋白A(SAA)水平与肺功能及炎性因子的相关性,并分析其诊断价值。方法:选取2013年6月-2018年6月中国人民解放军第970医院收治的204例慢性阻塞性肺疾病(COPD)患者作为研究对象,其中COPD稳定期患者132例作为COPD稳定组,AECOPD患者72例作为AECOPD组。另选取同期于中国人民解放军第970医院进行健康体检的50例健康体检者作为健康组。比较三组受试者血清SAA水平、白细胞介素-8(IL-8)、白细胞介素-6(IL-6)、C反应蛋白(CRP)、降钙素原(PCT)水平及肺功能,采用Pearson相关性分析AECOPD患者血清SAA水平与肺功能及炎性因子的相关性,并分析SAA对AECOPD的诊断价值。结果:AECOPD组患者血清SAA、PCT、CRP、IL-6、IL-8水平较COPD稳定组及健康组升高(P0.05),COPD稳定组患者血清SAA、IL-6、IL-8、PCT、CRP水平均高于健康组,差异有统计学意义(P0.05);AECOPD组患者第一秒用力呼气容积(FEV1)、用力肺活量(FVC)、第一秒用力呼吸容积占用力肺活量的百分比(FEV1/FVC%)、第一秒用力呼气容积占预计值百分比(FEV1%)低于COPD稳定组及健康组,差异有统计学意义(P0.05),COPD稳定组患者FEV1、FVC、FEV1/FVC%、FEV1%低于健康组,差异有统计学意义(P0.05)。Pearson相关性分析显示,AECOPD患者血清SAA水平与IL-8、IL-6、CRP、PCT呈正相关,与FEV1%、FEV1/FVC%、FEV1、FVC呈负相关(P0.05)。受试者工作特征(ROC)曲线结果显示,SAA对AECOPD诊断的敏感度为80.85%,特异度为80.07%,曲线下面积为0.832。结论:AECOPD患者血清SAA水平明显升高,其与患者肺功能及炎症因子存在相关性,具有较高的诊断价值,可用于AECOPD患者病情的评估。     

Distal projection of insufflated gas during tracheal gas insufflation.

Tracheal gas insufflation (TGI) flushes expired gas from the ventilator circuitry and central airways, augmenting CO2 clearance. Whereas a significant portion of this washout effect may occur distal to the injection orifice, the penetration and mixing behavior of TGI gas has not been studied experimentally. We examined the behavior of 100% oxygen TGI injected at set flow rates of 1-20 l/min into a simulated trachea consisting of a smooth-walled, 14-mm-diameter tube. Models incorporating a separate coaxial TGI injector, a rough-walled trachea, and a bifurcated trachea were also studied. One-hundred percent nitrogen, representing expiratory flow, passed in the direction opposite to TGI at set flow rates of 1-25 l/min. Oxygen concentration within the "trachea" was mapped as a function of axial and radial position. Three consistent findings were observed: 1) mixing of expiratory and TGI gases occurred close to the TGI orifice; 2) the oxygenated domain extended several centimeters beyond the endotracheal tube, even at high-expiratory flows, but had a defined distal limit; and 3) more distally from the site of gas injection, the TGI gas tended to propagate along the tracheal wall, rather than as a central projection. We conclude that forward-directed TGI penetrates a substantial distance into the central airways, extending the compartment susceptible to CO2 washout.     

Effect of chest strapping on regional lung function.

We studied lung mechanics and regional lung function in five young men during restrictive chest strapping. The effects on lung mechanics were similar to those noted by others in that lung elastic recoil increased as did maximum expiratory flow at low lung volumes. Chest strapping reduced the maximum expiratory flow observed at a given elastic recoil pressure. Breathing helium increased maximum expiratory flow less when subjects were strapped than when they were not. These findings indicated that strapping decreased the caliber of airways upstream from the equal pressure point. Regional lung volumes from apex to base were measured with xenon 133 while subjects were seated. The distribution of regional volumes was measured at RV, and at volumes equal to strapped FRC and strapped TLC; no change due to chest strapping was observed. Similarly, the regional distribution of 133Xe boluses inhaled at RV and strapped TLC was unaffected by chest strapping. Closing capacity decreased with chest strapping. We concluded that airway closure decreased during chest strapping and that airway closure was not the cause of the observed increase in elastic recoil of the lung. The combination of decreased slope of the static pressure-volume curve and unchanged regional volumes suggested that strapping increased the apex-to-base pleural pressure gradient.     

alpha-Difluoromethylornithine attenuates monocrotaline-induced airway/lung dysfunction.

On the basis of the previous findings that alpha-difluoromethylornithine (DFMO, an inhibitor of ornithine decarboxylase, which is the rate-limiting enzyme in polyamine biosynthesis) treatment prevents monocrotaline-(MCT) induced pulmonary hypertension and that ventilatory dysfunction precedes pulmonary hypertension in MCT-treated rats, we hypothesize that MCT-induced changes in airway/lung function are polyamine dependent. To evaluate this hypothesis, in phase 1, 48 young Sprague-Dawley rats were evenly divided into four groups: control, DFMO, MCT, and DFMO + MCT. Each DFMO rat received DFMO in its drinking water (2%) for 11 days, with additional injections (400 mg/kg sc) on the 5th day. Each MCT rat received a single injection of MCT (60 mg/kg sc) 1 wk before the functional study. Each DFMO + MCT rat received the same DFMO and MCT treatments as above, and MCT was administered on the 5th day of the DFMO treatment. In the MCT group, there were marked rightward shifts in pressure-volume and maximal flow-static recoil (MFSR) curves and significant decreases in dynamic and quasi-static compliance, the maximal expiratory flow, slope of the MFSR curve, and the carbon monoxide diffusing capacity, as well as a significant increase in alveolar wall thickness. However, in rats treated with DFMO + MCT, most of MCT-induced changes were significantly attenuated. To evaluate whether MCT causes bronchoconstriction, a bronchodilator, terbutaline (0.2 mg/kg i.v.), was administered to control (n = 7) and MCT (n = 11) rats in phase 2. Terbutaline significantly reversed MCT-induced decreases in maximal expiratory flow and slope of the MFSR curve, whereas it did not alter these parameters in controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

舒利迭无创通气对慢性阻塞性肺疾病合并呼吸衰竭患者肺功能及动脉血 气分析的影响

目的:探讨舒利迭联合无创通气对慢性阻塞性肺疾病(COPD)合并呼吸衰竭患者肺功能和动脉血气的影响。方法:选取2013年5月-2015年5月在我院接受治疗的COPD合并呼吸衰竭患者92例,根据治疗方法不同,将患者分为研究组和对照组。对照组患者给予控制感染、化痰、平喘等常规治疗,研究组在此基础上给予舒利迭无创通气治疗。采用血气分析仪检测两组患者治疗前后二氧化碳分压(PaCO_2)、血氧分压(PaO_2)及酸碱度(pH)等动脉血气指标。应用肺功能检测仪检测患者用力肺活量(FVC)、呼气高峰流量(PEFR)以及1 s用力呼气容积(FEV1)等肺功能指标。结果:治疗前,两组患者PaCO_2,PaO_2,pH,FVC,PEFR及FEV1比较,差异均无统计学意义(P0.05);治疗后,两组患者PaCO_2较治疗前明显下降,而PaO_2与pH明显上升,差异具有统计学意义(P0.05);治疗后,研究组PaCO_2低于对照组,而PaO_2与pH高于对照组,差异具有统计学意义(P0.05);治疗后,两组患者FVC,PEFR及FEV1明显上升,且研究组高于对照组,差异均具有统计学意义(P0.05)。结论:舒利迭联合无创通气对COPD合并呼吸衰竭患者肺功能及动脉血气具有明显的改善作用,值得临床推广及应用。     

Alpha-1-antitrypsin types and pulmonary disease among employees at a sulphite pulp factory in northern Sweden

Alpha-1-antitrypsin (alpha 1-AT) phenotypes and serum levels were measured in 518 employees at a sulphite pulp factory. There were 439 men and 79 women with the mean age of 42 years (range 18-65 years). Mean time of employment at the factory was 17.5 years and 216 (42%) individuals had been employed for more than 20 years. Chronic bronchitis was present in 47 (9.1%) individuals. alpha 1-AT rare types (MZ, MS, MF) were present in 12.8% of the individuals with chronic bronchitis compared to 8.4% in employees with no respiratory symptoms, the difference being not statistically significant. Individuals with chronic bronchitis and rare types were evenly distributed with regard to work place at the factory. Serum levels of alpha 1-AT were somewhat higher in smokers compared to non-smokers, but the difference was not statistically significant. Exposure to SO2 and chlorine did not seem to affect the serum levels of alpha 1-AT in M type individuals. In the present study, individuals heterozygous for alpha 1-AT deficiency phenotypes (MZ, MS, MF) did not seem to have an increased rate of chronic bronchitis. However, the rate of chronic bronchitis in factory employees was significantly increased compared to that among non-employees in the surrounding community. This increase appears to be due to a higher rate of smoking and to occupational exposure (SO2 and chlorine) among the sulphite pulp factory workers.     

A plethysmographic technique for direct measurement of airway resistance in hamsters

We have developed a new technique to directly measure airway resistance (Raw) in small animals with a pressure-type body plethysmograph equipped with a hot-wire microflow sensor. Seventeen male golden hamsters weighing 70-84 g were studied. Change in alveolar pressure (delta PA) was calculated from total gas volume and the respired volume difference through the flow sensor between the midpoints of the tidal excursion curve, reflecting the thorax movement. The ratio of delta PA to the flow difference between those two midpoints gave Raw. Raw was compared with pulmonary resistance, and inspiratory and expiratory resistances were also compared. Raw was 0.44 +/- 0.06 (SE) cmH2O.ml-1.s. Mean of the coefficients of variation of Raw was 19.6 +/- 3.2% (SE). Raw was well correlated with pulmonary resistance (r = 0.93). We demonstrated that Raw could be directly measured in small animals with a hot-wire flow sensor and a plethysmographic technique, and the values were well correlated with previously reported pulmonary resistance.     

Pulmonary emphysema associated with the FZ alpha 1-antitrypsin phenotype.

In one family three brothers were found to have a moderate deficiency of alpha 1-antitrypsin associated with the unusual Pi (protease inhibitor) phenotype FZ. The Pi phenotypes of their six living siblings were found to be FM (in three), M (in two) and MZ (in one). The three FZ brothers all had moderate to severe obstructive airways disease, and two had at least moderately severe pulmonary emphysema. Additional risk factors included moderate cigarette smoking in two and prolonged exposure to grain dust in all three. The same risk factors applied to the six non-FZ siblings, but they had only mild symptoms and pulmonary dysfunction or no lung problems at all; one, a female smoker with the MZ phenotype, had probable early emphysema demonstrated radiologically. The three FZ men may have had reduced fertility, as they produced only 1 child among them, as compared with 39 among the other eight siblings. This family study thus suggests that individuals with the FZ phenotype are at risk for pulmonary emphysema and chronic obstructive airways disease, particularly in the presence of other risk factors, such as cigarette smoking and grain dust exposure.     

Effect of long-term treatment with salmeterol on asthma control: a double blind,randomised crossover study.

OBJECTIVES: To determine the effect of adding salmeterol 50 micrograms twice daily for six months to current treatment in subjects with asthma who control their inhaled corticosteroid dose according to a management plan. DESIGN: A double blind, randomised crossover study. SETTING: Nottingham. SUBJECTS: 101 subjects with mild or moderate asthma taking at least 200 micrograms twice daily of beclomethasone dipropionate or budesonide. INTERVENTIONS: Salmeterol 50 micrograms twice daily and placebo for six months each, with a one month washout. Subjects adjusted inhaled steroid dose according to guidelines. MAIN OUTCOME MEASURE: Reduction in inhaled steroid use, exacerbations of asthma, and use of oral steroids. RESULTS: Data were available for 87 subjects. When compared with placebo salmeterol treatment was associated with a 17% reduction in inhaled steroid use (95% confidence interval 12% to 22%) with no significant difference in the number of subjects who had an exacerbation (placebo 25%, salmeterol 16%) or use of oral steroids. For secondary end points salmeterol treatment was associated with higher morning and evening peak expiratory flow and forced expiratory volume in one second; a reduction in symptoms, bronchodilator use and airway responsiveness to methacholine; and no effect on serum potassium concentration, 24 hour heart rate, or the final forced expiratory volume in one second achieved during a salbutamol dose-response study. CONCLUSIONS: In subjects who adjusted their inhaled steroid treatment according to guidelines the addition of salmeterol 50 micrograms twice daily was associated with a reduction in inhaled steroid use and improved lung function and symptom control.     

Ozone inhalation effects consequent to continuous exercise in females: comparison to males

Exposure to ozone (O3) at ambient photochemical smog alert levels has been shown to cause alteration in pulmonary function and exercise response in humans, but there is a paucity of data on females. The initial purpose of the present investigation was to study the effects of O3 inhalation on pulmonary function and selected exercise respiratory metabolism and breathing pattern responses in young adult females. Six female subjects exercised continuously on a bicycle ergometer for 1 h on 10 occasions at one of three intensities, while exposed to 0.0, 0.20, 0.30, or 0.40 ppm O3. Forced expiratory volume and flow rates and residual volume (RV) were measured before and immediately following each protocol. During exercise, expired minute ventilation (VE), respiratory frequency (fR), tidal volume, O2 uptake (VO2), and heart rate (HR) were measured every 10 min. O3 dose-dependent decrements were observed for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and forced expiratory flow rate during the middle half of FVC, coupled with an increase in RV and altered exercise ventilatory pattern. There was also an increased VE but no significant O3 effect on VO2 or HR. Comparison of the females' responses to those of a group of young adult males (previously studied) at the same total O3 effective dose (i.e., expressed as the simple product of O3 concentration, VE, and exposure time) revealed significantly greater effects on FVC, FEV1.0, and fR for the females. With VE reduced for females as a function of exercise intensity at the same percent of maximum VO2, these differences were considerably attenuated, although not negated.(ABSTRACT TRUNCATED AT 250 WORDS)