Rice burning and asthma hospitalizations, Butte County, California, 1983-1992

We investigated the association between rice burning and daily asthma hospitalizations in Butte County, California, from 1983 to 1992. Eighty-two percent of planted rice was burned, with a mean of 555 acres burned on days when burning was permitted. For 60% of the days during this period, no rice burning occurred. Peak burning occurred in fall and spring but was not correlated with criteria pollutants. Asthma admissions averaged 0.65/day and peaked in March. In the basic Poisson model with daily asthma hospitalizations as the outcome of interest, burn acreage showed a small but statistically significant elevation of risk for hospitalization per acre of rice burned [relative risk (RR) = 1.0001; 95% confidence interval (CI), 1. 00004-1.0002], after adjusting for maximum daily temperature, seasonal factors, and yearly population. In this model, burn acreage showed a dose-response effect as acreage burned increased. Days with the greatest acreage burned (>499 acres) had the largest risk of hospitalization (RR = 1.23; CI, 1.09-1.39), and days with moderate burning (between 100 and 499 acres) had a slightly lower risk of admission (RR = 1.2; CI, 1.05-1.37). Elevations of air pollutants were not associated with days of increased rice burning; however, rice burn acreage was shown to have a small but statistically significant effect on asthma morbidity in Butte County. This evidence suggests that further limitations on the daily amount of rice straw permitted to be burned should be considered to reduce pulmonary morbidity related to asthma.     

Effects of acute passive smoking on exercise-induced bronchoconstriction in asthmatic children

This study was designed to investigate the acute effects of environmental tobacco smoke (ETS) in children with mild asthma during rest and exercise. We studied 13 children [8 males, 5 females; mean age 10 (range 8-13) yr; mean forced expired volume in 1 s (FEV1) 93% (range 82-108%) of predicted] with exercise-induced bronchoconstriction [46 +/- 4% (SE) fall in FEV1 after exercise during cold air breathing]. Children were exposed to ETS (20 ppm carbon monoxide) or ambient air (AA) for 1 h. During the first 54 min of exposure, children were at rest, and during the last 6 min they exercised on a bicycle ergometer (2 W/kg body wt). Spirometry was performed before and during exposure and after exercise. Respiratory symptoms were recorded before and after exposures. In seven children the experiments with AA and ETS were done in duplicate. FEV1 between 5 and 54 min of exposure at rest decreased by 3.2 +/- 0.8% (SE) during AA and by 7.2 +/- 2.3% during ETS exposure compared with preexposure values; the difference between AA and ETS was statistically significant (P = 0.04). The drop in FEV1 was achieved within 5 min and did not change with ongoing exposure. Analysis of individual data revealed that the mean changes during ETS were mainly effected by three children with a significant fall and one child with a significant improvement in FEV1 (P < 0.05). Maximum postexercise fall of FEV1 was 25 +/- 4% after AA and 24 +/- 3% after ETS, which did not differ significantly. Upper and lower respiratory tract symptoms were not significantly different between exposures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Exhaled nitric oxide is higher both at day and night in subjects with nocturnal asthma

Nitric oxide in exhaled air is thought to reflect airway inflammation. No data have been reported so far on circadian changes in NO in subjects with nocturnal asthma. To determine whether exhaled NO shows a circadian rhythm inverse to the circadian rhythm in airway obstruction in subjects with nocturnal asthma, we conducted a study involving six healthy controls, eight individuals without nocturnal asthma (4-h to 16-h variation in peak expiratory flow [PEF] <= 15%), and six individuals with nocturnal asthma (4-h to 16-h PEF variation > 15%). Smoking, use of corticosteroids, and recent respiratory infections were excluded. NO concentrations were measured at 12, 16, 20, and 24 h, and at 4, 8, and 12 h of the next day, using the single-breath method. At the same times, FEV1 and PEF were also measured. Mean NO concentrations were significantly higher in subjects with nocturnal asthma than in subjects without nocturnal asthma, and higher in both groups than in healthy controls at all time points. Mean exhaled NO levels over 24 h correlated with the 4-h to 16-h variation in PEF (r = 0.61, p < 0.01). Exhaled NO did not show a significant circadian variation in any of the three groups as assessed with cosinor analysis, in contrast to the FEV1 in both asthma groups (p < 0.05). At 4 h, mean +/- SD NO levels were higher than at 16 h in subjects with nocturnal asthma; at 50 +/- 20 ppb versus 42 +/- 15 ppb (p < 0.05); other measurements at all time points were similar. Differences in NO and FEV1 from 4 h to 16 h did not correlate with one another. We conclude that subjects with nocturnal asthma exhale NO at higher levels both at night and during the day, which may reflect more severe diurnal airway-wall inflammation. A circadian rhythm in exhaled NO was not observed. NO levels did not correspond to the circadian rhythm in airway obstruction. The small increase in NO at 4 h may indicate an aspect of inflammation, but it is not associated with increased nocturnal airway obstruction.     

Respiratory disease in workers exposed to colophony solder flux fumes: continuing health concerns

The objectives of this study were to establish the prevalence of respiratory, eye, nose and throat symptoms of likely work-relation in workers exposed to colophony solder flux fumes and to assess their lung function. A cross-sectional study was conducted in four medium-sized electronics firms in which control measures to capture solder flux fume were absent or visibly ineffective. All female solders and women working adjacent to soldering stations completed an administered questionnaire concerning symptoms, work history and current soldering frequency. Measurements were made of their forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) during the course of a working shift, using a Vitallograph-Compact portable spirometer. Using weekly hours of soldering as a crude index of current exposure, workers were classified into high (> or = 37 h/wk) and low (< or = 20 h/wk) exposure groups, and their health responses were compared in the analysis. Individuals with symptoms suggestive of work-related asthma were also asked to provide serial peak flow measurements over a further 2-week period, and adequate returns were charted and read by two physicians experienced in the diagnosis of occupational asthma. Data were collected on 152 female workers (overall participation rate = 97%). Symptoms of recurrent, persistent wheeze and/or chest tightness were reported by 75 (49%) of interviewees; 36 (24%) gave a history typical of occupational asthma and six more (4%) a history of pre-existing asthma worsened at work. Twenty-one (14%) of the workforce complained of recurrent breathlessness on moderate exertion; 41 workers (27%) had work-related symptoms of the nose or throat and 25 (16%) had work-related eye symptoms. The odds ratios for 'all wheeze', shortness of breath, and work-related eye, nose and chest symptoms were all significantly greater (raised about 4-5 fold) in women who soldered > or = 37 h/wk when compared with those soldering < or = 20 h/wk. After adjustment by logistic regression for atopy, age and smoking status even higher risk estimates were generally obtained. The odds ratios (OR) and 95% confidence intervals (CI) for high vs. low were: for 'all wheeze', OR = 7.2, CI = 2.5-20.7; for work-related eye symptoms, OR = 5.2, CI = 1.4-19.8; for work-related nasal symptoms, OR = 4.0, CI = 1.4-11.1 and for occupational asthma symptoms, OR = 5.2, CI = 1.4-14.2. Mean FEV1 and FVC percentage difference from expected were slightly lower in full-time solderers than in part-time solderers, but the differences were not significant. Thirty-seven of the 51 workers (73%) who were asked to carry out serial peak flow measurements completed an adequate return: 27 of these records confirmed the presence of asthma, and in all of the cases the history suggested onset post-dating employment in soldering. Eleven peak flow records were indicative of occupational asthma. The health problems associated with colophony solder flux were documented over 18 years ago, but are still clearly apparent in situations where adequate control has not been achieved.     

Effect of age upon airway obstruction and reversibility in adult patients with asthma

OBJECTIVE: In a cross-sectional study we evaluated the effect of aging (separately from that of duration of disease) on airway obstruction and reversibility by comparing two groups of non-smoker patients with asthma. METHODS: We compared two groups of patients: group A, which had 50 subjects (8 men and 42 women) aged 59.7+/-4.6 years (mean +/- SD), and group B, comprised of 51 subjects (19 men and 32 women) who were 35.7+/-7.4 years old. The groups were selected because of comparable baseline degree of obstruction (FEV1 % of predicted, 67.8+/-20.3 in group A; 73.0+/-19.6 in group B, NS) and duration of the disease (14.0+/-11.7 years vs 11.2+/-9.1, NS). Spirometric examination, with a bronchodilator test, was performed and subjects not reaching 85% of predicted were submitted to a 4-week course of inhaled steroids. RESULTS: Although a higher number of subjects from group B responded to the acute bronchodilator test (p < 0.001), the maximum response achievable with treatment (steroid or bronchodilator) (deltaFEV1 expressed as the percent of predicted) was not statistically different between groups (12.0+/-17.5 vs 16.0+/-23.9). The mean FEV1 attainable after treatment (deltaFEV1%PT) was significantly lower in the older group (p = 0.0006). Within groups, the baseline FEV1% did not correlate with age; it was inversely correlated with the duration of the disease (p < 0.03 and p < 0.01, respectively). In both groups deltaFEV1 was inversely related with the baseline FEV1, whereas FEV1%PT was correlated with the duration of the disease, with a slope nearly doubled in group B (p < 0.001). CONCLUSIONS: Both the process of aging and the prolonged exposure to disease effects are important factors in determining the functional characteristics of chronic asthma: In particular, aging is associated not only with a reduced acute responsiveness to bronchodilators, but also with a reduced slope of the duration-FEV1%PT relationship that suggests a slowing of the rate of loss of reversibility of uncertain biological meaning.     

Long-term effects of therapy on respiratory health

Only scant information is available on the long-term consequences to respiratory health of treatment with bronchodilators and oral corticosteroids. In the present study, we aimed to gain more information about these consequences. We examined 712 men working in the Paris area, by means of a subjective assessment of whether their respiratory health worsened or improved from 1960 to 1972, the decline in forced expiratory volume in one second (FEV1) over this time-period, and mortality from 1972 to 1992, in relation to respiratory therapy dispensed during a 2 year period in 1970-1971, as recorded in social security reimbursement records. As expected, subjects with respiratory symptoms or airflow limitation were more likely to have been prescribed respiratory therapy. After accounting for the effect of lung function level and smoking, subjects dispensed inhaled beta-agonists were likely to feel their condition had worsened and had a greater decline in FEV1 from 1960 to 1972. Among subjects with airflow limitation who reported asthma or persistent wheeze, having been dispensed oral corticosteroids on an intermittent basis was associated with improved survival (relative risk (RR) 0.32; 95% confidence interval (95% CI): 0.10-0.91) after adjusting for FEV1 level and smoking category. Our results add to the evidence that regular use of beta-agonist bronchodilators may be associated with adverse effects on respiratory health, whilst intermittent use of corticosteroids may be of long-term benefit.     

Accelerated lung function decline in swine confinement workers

We conducted a longitudinal study to determine the annual rate decline in pulmonary function measurements in male swine confinement workers. For comparison, a grain farming group and a nonfarming rural-dwelling control group were also chosen for the longitudinal study. Two hundred seventeen swine confinement workers, 218 grain farmers, and 179 nonfarming control subjects had valid pulmonary function measurements at the baseline observation conducted in 1990 to 1991 and at the second observation conducted in 1994 to 1995. The swine confinement workers were younger (mean age=38.3+/-11.7 [SD] years) than the nonfarming control subjects (42.6+/-10.4 years) and the grain farmers (44.5+/-11.9 years). When stratified by age, nonfarming control subjects had the lowest mean annual rate decline in FEV1 and FVC in all age categories. The swine confinement workers had the largest annual rate decline in FEV1 and FVC, and this was most obvious in the middle age categories. After controlling for age, height, smoking, and baseline pulmonary function, swine confinement workers had excess annual decline of 26.1 mL in FEV1 (p=0.0005), 33.5 mL in FVC (p=0.0002), and 42.0 mL/s in forced expiratory flow between 25% and 75% of FVC (FEF[25-75%]) (p=0.02) over nonfarming control subjects. Grain farmers had excess annual decline of 16.4 mL in FEV1 (p=0.03), 26.7 mL in FVC (p=0.002), and 11.2 mL/s in FEF(25-75%) (p=0.38) over control subjects. These findings suggest that workers engaged in the swine industry and grain farmers appear prone to accelerated yearly losses in lung function and may therefore be at risk for the future development of chronic airflow limitation.     

Summertime haze air pollution and children with asthma

In order to investigate associations between summertime haze air pollution and asthma at an individual level, 52, 58, and 56 children (ages 7 to 13) attending a summer "asthma camp" were followed during the last week of June in 1991, 1992, and 1993, respectively. Most of the subjects had moderate to severe asthma. Daily records were kept of the environmental conditions, as well as of subject medication use, lung function, and medical symptoms. Air pollution was found to be significantly and consistently correlated with acute asthma exacerbations, chest symptoms, and lung function decrements. The pollutant most consistently associated with adverse health consequences was ozone (O3), although associations with sulfates and hydrogen ion suggest a possible role by fine particles as well. Effects were found to be roughly monotonic as a function of O3 concentration. Regression of morning (8:00 A.M.) to afternoon (5:00 P.M.) peak flow change on O3 indicated pulmonary function reductions similar to those previously reported for more active children without asthma. Moreover, analyses also indicated an increased risk of an asthma exacerbation and of experiencing chest symptoms of approximately 40% on the highest pollution day, relative to the mean. Based on these relative risk estimates, a rise in the 1-h daily maximal O3 from 84 ppb to 160 ppb was associated in this group with an increase from 20 to 28 (+/- 2) in the expected number of unscheduled medications administered/day, and from 29 to 41 (+/- 3) in the expected total number of chest symptoms/day. Thus, air pollution can be a major contributor to the respiratory problems experienced by children with asthma during the summer months.     

Is bronchial hyperresponsiveness more frequent in women than in men? A population-based study

To test the hypothesis that a greater proportion of women than men react to methacholine challenge and investigate the possible reasons for any differences observed, we recruited 495 subjects 20 to 44 yr of age (50.9% male) in Paris and 304 subjects (51.3% male) in Montpellier (France), as part of the European Community Respiratory Health Survey. The proportion of responders (PD20 < or = 4 mg methacholine) was 33.7% in women and 11.9% in men (odds ratio = 3.8; 95% confidence interval = 2.4-6.0) in Paris and 43.2% in women and 29.5% in men (odds ratio = 1.8; 95% confidence interval = 1.1-2.9) in Montpellier. These differences could not be explained by asthma, respiratory symptoms, atopy, or lung function parameters. In stepwise logistic regressions including sex, asthma, and asthma-like symptoms, nasal allergies, atopy, baseline FEV1, FEV1%pred, FVC, and FEV1%FVC, the odds-ratios for the effect of female sex on PD20 < or = 4 mg methacholine were 5.2 (3.0-9.0) in Paris and 2.2 (1.2-3.8) in Montpellier. Reacting to low doses of methacholine (PD20 < or = 0.5 mg) was associated with asthma and atopy in both men and women. In contrast, reacting to doses between 0.5 and 4 mg was associated with asthma and atopy only in men and with heavy tobacco consumption only in women. We conclude that the excess of hyperresponsiveness in women is not due to their having smaller lung size or airway caliber than men and may be related to a greater susceptibility to smoking.     

Asthma in the elderly: underperceived, underdiagnosed and undertreated; a community survey

Bronchial asthma is now increasingly recognized in the elderly and is associated with significant morbidity and mortality. The aims of this study were two-fold: first, to assess the prevalence and, second, to evaluate diagnostic awareness, therapeutic management and patient perception of bronchial asthma among elderly patients in the community. From the age-sex register of an urban general practice in NE England, 2004 patients aged > 65 years were eligible for inclusion. Response to an initial screening questionnaire on respiratory symptomatology was 68% (n = 1362). Of these, 869 patients had respiratory symptoms: 390 voluntarily agreed to be evaluated further including assessment of airway physiology. In this group 369/390 had obstructive spirometry and, of these, 95 patients fulfilled clinical and physiological criteria of bronchial asthma. Prevalence of asthma within this age cohort was minimally and rather crudely assigned at 4.5% (95/2004). Among the 95 patients so-defined patients with asthma [age 70 +/- 8 years (mean +/- SD), FEV1 = 0.96 +/- 0.41, 33 male, 75 life-long non-smokers], subjective awareness, perception and attribution of pulmonary symptoms were poor. Further, despite tangible evidence of reversible and significant airflow limitation, only 21 were receiving inhaled glucocorticoid therapy (median daily dose 400 micrograms). Asthma in the elderly remains poorly perceived, poorly recognized and suboptimally treated. These findings are particularly apposite in the light of current epidemiological trends in asthma mortality and morbidity in elderly age cohorts.     

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.     

Association of spatial distribution of childhood respiratory morbidity with environmental dust pollution

The objective of this study was to investigate the spatial distribution of respiratory morbidity and asthma in children in relation to high levels of airborne dust pollution. A cross-sectional survey of 2035 children (aged 5-11 yr) by parent-completed questionnaire, with concurrent monitoring of dust deposition rates in the vicinity of children's homes, was performed in 15 primary schools (5 in each of 3 areas of Merseyside). The main outcome measures were (1) doctor-diagnosed asthma, (2) parent-reported respiratory symptoms of recent excess cough, wheeze, and breathlessness, and (3) school absenteeism due to respiratory ill health. Proximity to the source of dust pollution was associated with increased prevalence of excess cough, breathlessness, school absence due to respiratory ill health, and doctor-diagnosed asthma, after adjusting for a range of socioeconomic, environmental, and other confounding factors. The adjusted odds for excess cough and breathlessness for children living within 2 km of the source (dock area) are estimated to be almost twice those for children living more than 2 km away: excess cough 1.9 (95% CI 1.4-2.6); breathlessness 1.9 (1.3-2.7); school absence 1.5 (1.2-1.9); and doctor-diagnosed asthma 1.5 (1.1-2.0). Excess cough was significantly associated with the mean annual dust deposition recorded in the vicinity of the child's home. The adjusted odds ratio for excess cough corresponding to an increase in mean annual dust deposition of 50 mg/m2/d was 3.1 (95% CI 1.1-8.2). These results suggest that airborne dust was associated with respiratory morbidity in these children, which could relate to the high prevalence of childhood doctor-diagnosed asthma in this community.     

Lung epithelial permeability and bronchial responsiveness in subjects with stable asthma

Lung epithelial permeability of asthmatic patients has been reported to be similar or lower than that of healthy subjects and to be correlated or not to bronchial hyperresponsiveness. To clarify these discrepancies, we evaluated 99mTc-DTPA pulmonary clearance in a group of carefully selected asthmatic patients with mild, stable asthma (n = 13; seven women; mean age +/- SD = 27.69 +/- 6.63 years), and compared them with a group of healthy, nonsmoking subjects (n = 8; six women; mean age +/- SD = 24.38 +/- 5.15 years). Selection criteria for asthmatics were as follows: baseline FEV1 > or = 80% of predicted values, no bronchial infections, and/or no asthma attacks during 4 weeks prior to study and peak expiratory flow rate variability lower than 20%, over a period of 3 weeks. Patients controlled symptoms with beta 2-adrenergic drugs only, regularly or on demand. Mean baseline FEV1 (+/-SD) as percent of predicted was 102.38 +/- 13.97 and 112.88 +/- 18.36, respectively (p < 0.05). In the asthmatic group, bronchial responsiveness to methacholine (PC20 M FEV1) ranged between 0.55 and 28.5 mg/mL. Mean value (+/-SD) of DTPA clearance from lungs to blood (evaluated on the first 10 min out of 30 min of the curves) in the asthmatic group was not different from that of control group (68.31 +/- 21.46 and 69.5 +/- 15.73). In the asthmatic patients, there was no correlation between PC20 M values and DTPA T1/2 min of the whole lung, nor between PC20 M and inner and outer lung clearance zones. Moreover, both in asthmatics and healthy subjects, DTPA clearance of outer (alveolar) zones was significantly faster than that of inner (bronchial) zones (57.69 +/- 19.94 vs 102.08 +/- 38.19, p < 0.001, and 59.75 +/- 12.49 vs 103.5 +/- 31.86, p < 0.003, respectively). Our data show that DTPA clearance in patients with stable asthma is similar to that found in healthy subjects; it is not correlated to degree of bronchial responsiveness and occurs more rapidly in the outer zones than in the inner zones, both in asthmatic patients and in healthy subjects. Thus, to date, DTPA clearance index is not a valid tool for identifying and/or monitoring asthmatic patients.     

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.     

Structure of the latissimus dorsi muscle and respiratory function

The aim of this study was to evaluate whether respiratory function influences the structure of the latissimus dorsi muscle (LD). Twelve patients (58 +/- 10 yr) undergoing thoracotomy were studied. Lung and respiratory muscle function were evaluated before surgery. Patients showed a forced expired volume in 1 s (FEV1) of 67 +/- 16% of the reference value, an FEV1-forced vital capacity ratio of 69 +/- 9%, a maximal inspiratory pressure of 101 +/- 21% of the reference value, and a tension-time index of the diaphragm (TTdi) of 0.04 +/- 0.02. When patients were exposed to 8% CO2 breathing, TTdi increased to 0.06 +/- 0.03 (P < 0.05). The structural analysis of LD showed that 51 +/- 5% of the fibers were type I. The diameter was 56 +/- 9 microns for type I fibers and 61 +/- 9 microns for type II fibers, whereas the hypertrophy factor was 87 +/- 94 and 172 +/- 208 for type I and II fibers, respectively. Interestingly, the histogram distribution of the LD fibers was unimodal in two of the three individuals with normal lung function and bimodal (additional mode of hypertrophic fibers) in seven of the nine patients with chronic obstructive pulmonary disease. An inverse relationship was found between the %FEV1-forced vital capacity ratio and both the diameter of the fibers (type I: r = -0.773, P < 0.005; type II: r = -0.590, P < 0.05) and the hypertrophy factors (type I: r = -0.647, P < 0.05; type II: r = -0.575, P = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of the incidence of clinical symptoms and risk factors for COPD based on the monitoring of refinery workers in Piock (1993-1996)

Work place environment plays an important role in development diseases because of the time spend in and different toxic factors placed in it. The aim of study was to assess the ventilatory efficiency in individuals employed in Generating Plant (GP) in relation to the pollution of the work place and the tobacco smoking habit during 3 years. The study covered a group of 144 male individuals employed at GP. (age 39.3 +/- 8.7 yrs, period of employment 20.3 +/- 8.6 yrs, smokers 53.5%. Lung function tests consisted of VC, FVC, FEV1, FEV1%VC, PEF, FEF50 counted from flow-volume curve and TGV, Rt measured using pletysmographic method. All tests were performed using pletysmograph (Masterlab) "Jaeger" placed on the ambulance near to the work place. The measurements were taken in May 1993 and 1996. Results were compared to with normal values (acc. ECSC). The anamnesis was obtained from all workers in the form of questionnaire projected for this study. All measurements were done during work time (9.00 a.m. to 2.00 p.m.). Mean values of the ventilation indices remained within the normal range but comparing results in smokers and non-smokers group significant differences in FEV1 and TGV were found. The symptoms of chronic bronchitis were present in 20.8% of persons. Spirometric criteria for the COPD diagnosis were found in 16 persons (11%). Only 5 persons (31%) were symptomatic. The mean decrease of FEV1 was 16.2 ml/yr, in the COPD group it was 82.5 ml/yr. The greater annual loss of FEV1 was found in the smokers and symptoms groups.     

Caretaker recognition of respiratory signs in children: correlation with physical examination findings, x-ray diagnosis and pulse oximetry

Caretaker recognition of clinical utility of respiratory signs and symptoms in the prediction of pneumonia was examined in a prospective study of infants and children in four cities in Egypt. In all 688 children aged 2 months-5 years presenting with a history and/or physical examination findings of cough and difficult or fast breathing were recruited from out-patient health facilities. The validity of caretaker terms was determined using paediatrician observation of standard respiratory signs and symptoms, x-ray diagnosis and pulse oximetry as standards. The sensitivity of 'nahagan' (Egyptian Arabic for fast breathing) for identifying elevated respiratory rate was 78% +/- 4, and was slightly higher for < 12 month olds (85% +/- 5) versus children aged 1-5 years (74% +/- 5). 'Sedro tale nazel', which describes the chest as moving up and down, was a sensitive (86% +/- 3) and specific (60% +/- 4) indicator of chest indrawing. 'Tazyeek' (wheeze) had a sensitivity of 75% +/- 3 and specificity of 66% +/- 4 when compared to paediatrician assessment of wheezing during physical examination. Although not specific, the caretaker terms, 'nahagan' or 'nafas seria' (fast breathing) and 'sedro tale nazel' (chest indrawing), either spontaneously or after asking, were sensitive (> 71%) indicators of radiologic pneumonia and oxygen desaturation, and therefore can be used to prompt timely health seeking behaviour in these settings.     

The effect of salmeterol on nocturnal symptoms, airway function, and inflammation in asthma

STUDY OBJECTIVE: To determine the efficacy of salmeterol alone in a group of patients with moderate asthma with nocturnal worsening of symptoms. DESIGN: Double-blind, randomized, placebo-controlled crossover study. SETTING: Tertiary care hospital specializing in respiratory diseases. PARTICIPANTS: Ten patients with nocturnal asthma. INTERVENTIONS: Subjects were randomized to salmeterol, 100 micrograms twice daily, or placebo for 6 weeks with a 1-week washout between treatment periods. Symptoms, nocturnal awakenings, and beta 2-agonist use were recorded daily. Spirometry was performed at weeks 1 and 6 of each period at bedtime and at 4 AM, and methacholine challenge was performed at 4 AM followed by bronchoscopy with BAL. BAL fluid analysis included cell count and differential count, eosinophil cationic protein, Charcot-Leyden crystal protein, leukotriene B4, and thromboxane B2. RESULTS: The percentage of nights with awakenings decreased significantly with salmeterol (69.8 +/- 8.7% vs 30.6 +/- 10.8% for placebo and salmeterol, respectively; p = 0.02). The percentage of 24-h days with supplemental inhaled beta 2-agonist use significantly decreased with salmeterol (85.9 +/- 9.4% vs 70.4 +/- 10.1% for placebo and salmeterol, respectively; p = 0.04). There were no significant differences in bronchial reactivity, 4 AM FEV1, overnight percentage change in FEV1, or indexes of airway inflammation. CONCLUSIONS: Salmeterol alone improves the number of nocturnal awakenings and supplemental 24-h beta 2-agonist use in nocturnal asthma without significantly altering lung function and airway inflammation.     

Respiratory quotient is inversely associated with muscle sympathetic nerve activity

The relative amounts of the macronutrients oxidized by an individual are reflected in the respiratory quotient (RQ), which varies inversely with lipid oxidation. A high RQ, indicating a relatively low lipid oxidation, and a low activity of the sympathetic nervous system have both been identified as risk factors for body weight gain. The stimulatory effect of norepinephrine on lipid oxidation suggests that low lipid oxidation may contribute to the relationship between low sympathetic nervous activity and body weight gain. The purpose of the present study was to determine whether low basal muscle sympathetic nerve activity (MSNA), a direct measure of sympathetic nervous outflow, is independently associated with low lipid oxidation. Intraneural recordings of basal MSNA were performed in 39 healthy, nondiabetic males, 19 Caucasians (mean +/-SD, 33 +/- 9 yr, 91 +/- 23 kg, and 28 +/- 11% body fat) and 20 Pima Indians (30 +/- 5 yr, 94 +/- 25 kg, and 35 +/- 8% fat) immediately after measurement of 24-h RQ in a respiratory chamber. Basal MSNA, energy balance, and age were independent determinants of 24-h RQ, together explaining 45% of its variability. Accordingly, 24-h RQ adjusted for energy balance and age was inversely related to MSNA (r = -0.41; P = 0.01). Race, percent body fat, and fasting plasma insulin were not independent determinants of 24-h RQ. Although MSNA explained only a limited part of the variability in 24-h RQ, the results support the hypothesis that an effect on lipid oxidation contributes to the demonstrated relationship between low activity of the sympathetic nervous system and body weight gain.     

Acute neurohumoral and cardiovascular effects of idarubicin in leukemia patients

To examine the nature of asthma in the elderly, we compared older (group 1: 65 years or older, n = 50) with younger patients (group 2: <40 years, n = 99) and to determine the influence of long-standing disease, elderly asthmatics with early onset (group A: onset before 40, n = 22) were compared with patients developing symptoms later in their lives (group B: onset after 40, n = 22). Blood eosinophilia and IgE value >/=100 IU/l were more frequent in younger patients. Short symptom-free periods were more frequent among older asthmatics (78.5 vs. 45.4%, p < 0.001). Only 31.2% of older patients had only mild symptoms. Requirement of systemic steroids was higher in the elderly population. The worst FEV1 was lower in older patients (54.4 +/- 17.3 vs. 71.8 +/- 18.5%, p 相似文献