云南宁蒗地区摩梭人体脂肪参数对肺通气功能的影响

目的：探究云南宁蒗地区摩梭人的身体脂肪参数对肺通气功能的影响，为改善摩梭人身体素质提供依据。 方法：随机抽取云南宁蒗地区摩梭人365 名（ 男性139 名，女性226 名）为研究对象，采用生物电阻抗法对所有 受试者进行人体成分的测量，分析体脂肪参数（BFP）与肺活量（VC）、用力肺活量（FVC）、第1 秒用力呼气量（FEV １）、第1 秒用力呼气量占用力肺活量比值（FEV1/FVC）等肺通气功能指标的关系。所得数据经SPSS20.0 统计软 件包进行统计学处理。结果：云南宁蒗地区摩梭人的体脂分布大多处于正常范围，尤其是女性；BFP过高的以男 性居多；不同BFP组间的男、女性摩梭人的VC差异有统计学意义，但FVC、FEV1、FEV1/FVC 差异均无统计学意义； 肺活量体质量指数均随着BFP的增加呈下降趋势，差异有统计学意义。但不分高低的BFP除与肺活量体质量指数 呈负相关，与其余肺通气功能主要指标之间均无相关；在男性摩梭人中，BFP过轻组的肺活量体质量指数与身体 各部位脂肪参数无相关性，其他2 组肺活量体质量指数与身体各部位脂肪参数呈负相关。女性摩梭人BFP过低组、 标准组和过高组的肺活量体质量指数与身体各部位脂肪参数均呈负相关。结论：云南宁蒗地区摩梭人BFP升高是 肺通气功能下降损伤的危险因素，肺活量体质量指数随BFP的增加而减低。     

Studies of normal values and prediction equations for pulmonary function--spirometry and flow-volume measurements in healthy Japanese children 6 to 14 years of age

We analyzed spirometric data (spirograms and flow-volume curves) on 1,357 healthy Japanese children (6-14 yr, 709 males and 648 females) in Higashimatsuyama, Saitama. The area was selected as the representative of the less polluted area in Japan, as we intended to exclude possible effects of air-pollution on spirometric values. Hot-wire anaemometers (AS 3500, AS 4500, MINATO) were used in the spirometry and the test procedures were done following the American Thoracic Society recommendations. By multiple regression analysis prediction equations were obtained for VC, FVC, FEV1, FEV1/FVC (%), MMFR, PEFR (Peak Expiratory Flow Rate), V75, V50, and V25. The selected variables were height and weight for VC, FVC and FEV1 but only height for MMFR, PEFR, V75, V50 and V25. Since there was no significant correlations between FEV1/FVC (%) and these variables, we defined normal ranges for FEV1/FVC (%). The predicted values derived from our equations were larger than those obtained from the other studies published in Japan. The difference is probably due to the improvement in the body size of Japanese children and the equipments used.     

Long-term exposure to background air pollution related to respiratory and allergic health in schoolchildren

BACKGROUND: The impact of air pollution on asthma and allergies still remains a debate. OBJECTIVE: Our cross-sectional study was intended to analyse the associations between long-term exposure to background air pollution and atopic and respiratory outcomes in a large population-based sample of schoolchildren. METHODS: Six thousand six hundred and seventy-two children aged 9-11 years recruited from 108 randomly schools in six French cities underwent a clinical examination including a skin prick test (SPT) to common allergens, exercise-induced bronchial reactivity (EIB) and skin examination for flexural dermatitis. The prevalence of asthma, allergic rhinitis (AR) and atopic dermatitis was assessed by a standardized health questionnaire completed by the parents. Three-year-averaged concentrations of air pollutants (NO2, SO2, PM10 and O3) were calculated at children' schools using measurements of background monitoring stations. RESULTS: After adjusting for confounders, EIB, lifetime asthma and lifetime AR were found to be positively related to an increase in the exposure to SO2, PM10 and O3. The adjusted odds ratios (aOR) per increase of 5 microg/m3 of SO2 was 1.39 (95% confidence interval (CI)=1.15-1.66) for EIB and 1.19 (1.00-1.41) for lifetime asthma. The aOR for lifetime AR per increase of 10 microg/m3 of PM10 was 1.32 (CI=1.04-1.68). Moreover, SPT positivity was associated with O3 (aOR=1.34; CI=1.24-1.46). Associations with past year symptoms were consistent, even if not always statistically significant. Results persisted in long-term resident (current address for at least 8 years) children. However, no consistent positive association was found with NO2. CONCLUSIONS: A moderate increase in long-term exposure to background ambient air pollution was associated with an increased prevalence of respiratory and atopic indicators in children.     

Pulmonary effects of sulfur dioxide exposure and ipratropium bromide pretreatment in adults with nonallergic asthma

In this study we examined the potential short-term effect of sulfur dioxide (SO2) on total respiratory resistance and forced expiratory volume in patients with nonallergic asthma. A group of nine adult subjects with nonallergic asthma, 55 years of age or older, were exposed to SO2 at 0, 0.5, and 1.0 ppm for 20 minutes at rest followed by 10 minutes during light-moderate exercise. The measures of pulmonary function assessed were FEV1, specific total respiratory resistance (SRT), and maximal expiratory flow rates at 50% (Vmax50) and 75% (Vmax75) of expired vital capacity. Measurements were made before exposure to SO2 (baseline), postresting exposure, postexercising exposure, and at 30 minutes thereafter (recovery). Repeat measure analysis of variance revealed a statistically significant dose-response effect of SO2 inhalation on FEV1 (p = 0.008), SRT (p = 0.033), Vmax50 (p = 0.017), and Vmax75 (p = 0.048). Eight subjects had repeat exposure to SO2 at 1.0 ppm after treatment with either placebo or ipratropium bromide, 60 micrograms by metered-dose inhaler. Inpratropium bromide treatment, compared to placebo treatment, resulted in a statistically significant improvement in all baseline measures of pulmonary function: FEV1 (p = 0.017), SRT (p = 0.027), Vmax50 (p = 0.018), and Vmax75 (p = 0.035). However, this drug did not significantly alter the proportionate change in pulmonary function caused by SO2 inhalation in these subjects. These findings indicate that adults with nonallergic asthma are sensitive to short-term low-level SO2 exposure and that treatment with 60 micrograms of ipratropium bromide causes significant bronchodilation but does not protect, completely, these patients from the effect of SO2 inhalation.     

Influence of matching volume on reproducibility of maximal expiratory flow-volume curves

We examined the influence of "matching volume" on intrasubject variability of the descending limb of maximal expiratory flow-volume (MEFV) curves on air and helium-oxygen (He) in 18 healthy subjects and 28 patients with airflow limitation. Duplicate forced expirations were analysed according to four methods of alignment. With the first method, flows corresponding to identical percentiles of separate FVC (SEPVC) were compared. With the remaining three, we aligned curves at TLC, mid-vital capacity (VC50) and RV, respectively, for comparison of: a) flow at identical percentiles of the averaged FVC and b) expired volume at identical percentiles of the averaged peak flow. In healthy subjects, variability of flow at 50% and 75% of expired FVC (FEF50 and FEF75) did not change significantly with method, except that FEF75 on air varied more with method SEPVC than with VC50. In airflow limitation, FEF75 was significantly less reproducible when curves were matched at RV than at TLC, both on air and He. Over the latter part of expiration, an arbitrary index of variability of flow-defined volume also indicated that method RV gave the poorest precision in patients. We conclude that selection of matching volume does not influence the variability of MEFV-curves in health. In airflow limitation, however, TLC appears to be the most reliable volume for alignment.     

Blood lead levels,pulmonary function and agility in Polish schoolchildren

Background: Reduced vital capacity (VC) and forced vital capacity (FVC) are associated with lead (Pb) exposure.

Aim: The objective of this study is to analyse the effects of Pb on FVC and the shuttle run performance.

Subjects and methods: Data were available for 184 male and 189 female Polish schoolchildren aged 10–15?years. Regression analysis was performed of shuttle run performance (dependent) on Pb and FVC.

Results: Shuttle run time increased by 1.75 (±?0.77) and 1.97 (±?0.77) seconds for each 10?µg/dL increase in Pb blood among males and females, respectively. Higher shuttle run times indicate poorer performance. Average unadjusted blood Pb level in the sample was 5.27?μg/dL (±?0.19 SE) and 3.82?μg/dL (±?0.10 SE), respectively. Path analysis was used to assess the association of Pb level with shuttle run time. Blood Pb had a significant negative effect on VC (B=??13.60?±?3.28 [SE], p?B?=??13.08?±?3.27, p?B?=??0.04?±?0.007, p?B?=?1.59?±?0.75, p?B?=?1.49?±?0.73, p?Conclusions: Thus, Pb had direct and indirect effects that increased shuttle run time, i.e. negatively affected performance.     

Diesel exhaust particles enhance T-cell activation in severe asthmatics

Prevalence of asthma is increasing in westernized countries. Epidemiological studies showed the impact of traffic pollution on the triggering of asthma symptoms and exacerbations, and this effect is mainly attributed to the polycyclic aromatic hydrocarbon core of diesel exhaust particles (DEP). However, although DEP induce IgE synthesis, little is known of their role on T-cell activation, the main cells orchestrating asthma inflammation. We assessed the effect of DEP on T-cell activation in severe uncontrolled asthmatics during (n = 13) and outside (n = 19) exacerbations. Results were compared with data obtained in healthy controls (n = 14). Peripheral blood mononuclear cells were cultured in the presence of low-dose DEP. T-cell activation markers, CD69 and CD25, interleukin-4 (IL-4) and interferon (IFN)-gamma production and T-cell proliferation were assessed by flow cytometry. DEP exposure increased the proportion of CD3+CD69+ T cells in all subjects. The proportion of CD25+ T cells increased under DEP stimulation in the exacerbation group only. IFN-gamma- and IL-4-producing T cells increased in both asthmatic groups, especially during exacerbations, but not in controls. This effect was more pronounced for IL-4. In response to DEP stimulation, T-cell proliferation increased in higher proportion in asthmatics compared with controls. These results show that DEP activate T cells in asthmatics only, with a higher effect during exacerbations. This is in keeping with epidemiological data which demonstrated that DEP trigger respiratory symptoms in asthmatics but not in controls. The higher effect of DEP in exacerbated asthmatics suggests that uncontrolled asthma is a risk factor for aggravation under exposure to traffic pollutants.     

Non-reversibility of vinyl chloride carcinogenesis in rodents

A review of the data obtained from various studies on carcinogenicity of vinyl chloride (VC) in rodents, particularly on the effect of dose, age, duration of exposure and potential reversibility of lesions, revealed that vinyl chloride-induced carcinogenicity in rodents was dose and time related; no recovery occurred in mice even after only 1 month of VC exposures or in rats after 6-month exposures. In addition, younger animals (2 months old) were more susceptible to VC-induced carcinogenicity than animals held for 6 or 12 months prior to exposure. Initial 6 or 12 month exposures were adequate to detect the carcinogenic potential of VC. The above information was used as a basis for discussion on design of carcinogenicity studies. Possibility of determining the carcinogenic potential of a compound in a shorter period than the traditional 2 year studies in rodents was discussed in consideration with appropriate doses, species, age and exposure duration. Although this approach may be applicable to a strong carcinogen, it was not considered practicable in case of weak or unknown carcinogens.     

Effect of occupational exposure and smoking on spirometric tests and symptoms of chronic bronchitis

The importance of occupational exposure to airborne agents in the development of obstructive lung disease is uncertain. The aim of the study was to evaluate the effects of smoking and of occupational exposure on the lung function and chronic respiratory symptoms. I studied a group of 1239 adults (766 men and 473 women; mean age 44.9 +/- 8.6 yrs; current smokers 42.1%, lifetime nonsmokers 41.6%) working in 5 factories in the Bielsko-Biala area. Simple spirometric test (FEV1, FVC, FEV1%FVC) and a questionnaire on chronic respiratory symptoms, smoking habits and occupational exposures were applied. Respiratory symptoms and lung function were studied in relation to years of occupational exposure and adjusted for smoking habit. Occupational exposure was reported by 35.7% (n = 442) participants (dust 20.6%; gases or fumes 27.6%; mixed exposure 51.8%), with a mean duration of 20.9 +/- 9.2 years. In all cases concentrations of noxious agents did not exceed allowed levels. The symptoms of chronic bronchitis (cough and phlegm) were present in 12.3% and airflow limitation (FEV1% FVC < 0.7) in 6.9% of subjects. The significant relation of respiratory symptoms and bronchial obstruction to smoking was confirmed. No significant association between occupational exposure and ventilatory function or respiratory symptoms was found in a whole group. Smoking--specific analysis showed that current smokers appeared to be more susceptible to the effects of professional exposure. It was expressed in lower lung function indices and significantly higher odds ratios for airflow limitation or chronic respiratory symptoms for smokers exposed compared to nonexposed. Sufficient evidence of health selection processes known as a "healthy smoker" and a "healthy worker" effects were revealed.     

A centrifuge simulated push–pull manoeuvre with subsequent reduced +Gz tolerance

The push-pull effect (PPE) has been recognized as a deleterious contributor to fatal flight accidents. The purpose of the study was to establish a push-pull manoeuvre (PPM) simulation with a tri-axes centrifuge, studying the effect of this PPM on the +Gz tolerance, and to make this simulation suitable for pilot centrifuge training. The PPM was realized through pre-programmed acceleration profiles consisting of -1 Gz for 5 s followed by a +Gz plateau for 10 s. Relaxed +Gz tolerance recordings were obtained from 20 healthy male fighter aircraft pilots and 6 healthy male volunteers through exposure to pre-programmed profiles with and without previous -1 Gz exposure. A statistically significant decrease in +Gz tolerance was seen in all subjects after -1 Gz for 5 s exposure, 0.87 ± 0.13 G in the volunteer group and 0.95 ± 0.25 G in the pilot group. The ear opacity pulse as a +Gz tolerance endpoint criterion was sometimes found to be unreliable during the PPM experiments. The simulated PPM in this study elicited a PPE, which was obvious from the significant reduction in +Gz tolerance. The PPM profile appears useful to be included in centrifuge training.     

Exposure to air pollution during different gestational phases contributes to risks of low birth weight

BACKGROUND: Although there have been growing concerns about the adverse effects of air pollution on birth outcomes, little is known about which specific exposure times of specific pollutants contribute to low birth weight (LBW). METHODS: We evaluated the relationships between LBW and air pollution exposure levels in Seoul, Korea. Using the air pollution data, we estimated the exposure during each trimester and also during each month of pregnancy on the basis of the gestational age and birth date of each newborn. Generalized additive logistic regression analyses were conducted considering infant sex, birth order, maternal age, parental education level, time trend, and gestational age. RESULTS: The monthly analyses suggested that the risks for LBW tended to increase with carbon monoxide (CO) exposure between months 2-5 of pregnancy, with exposure to particles <10 micro m (PM(10)) in months 2 and 4, and for sulphur dioxide (SO(2)) and nitrogen dioxide (NO(2)) exposure between months 3-5. CONCLUSIONS: This study suggests that exposure to CO, PM(10,) SO(2) and NO(2) during early to mid pregnancy contribute to risks for LBW.     

Incidence and epidemiology of Citrus tristeza virus in the Valencian community of Spain

The first outbreak of citrus tristeza disease in Spain caused by Citrus tristeza virus (CTV) was recorded in 1957 in the Valencian Community (VC). In total c. 40 million trees, mainly of sweet orange and mandarin grafted on sour orange rootstocks, declined due to CTV. Large-scale surveys in different municipalities of the VC indicated that the disease spread very fast. Incidence increased from 11% in 1989 to 53% in 1998. Toxoptera aurantii and Aphis spiraecola (inefficient aphid vectors of CTV) predominated before 1985-87. Since then the relatively efficient vector Aphis gossypii has become dominant and induced an epidemic that has been modelled. The large number of A.gossypii that visited each clementine tree (estimated to exceed 97000 per year) explained the difference between the temporal pattern of spread of CTV in clementine which followed the Gompertz model and that in sweet orange (logistic model). The susceptibility of the different citrus species to CTV infection by aphids seems to depend on the number of young, succulent shoots produced. The epidemiological data allowed specific recommendations to be made to growers in order to facilitate a change to a modern citrus industry based on the use of selected varieties grafted on tristeza-tolerant rootstocks produced within a certification scheme. This has been done already in almost 90% of the VC citrus-growing area. The tristeza problem has been solved unless more aggressive isolates are introduced and become prevalent.     

Effect of developmental and ancestral high altitude exposure on chest morphology and pulmonary function in Andean and European/North American natives

Chest depth, chest width, forced vital capacity (FVC), and forced expiratory volume (FEV1) were measured in 170 adult males differing by ancestral (genetic) and developmental exposure to high altitude (HA). A complete migrant study design was used to study HA natives (Aymara/Quechua ancestry, n = 88) and low altitude (LA) natives (European/North American ancestry, n = 82) at both altitude (La Paz, Bolivia, 3,600 m) and near sea level (Santa Cruz, Bolivia, 420 m). HAN and LAN migrant groups were classified as: N^th generation migrants, born and raised in a non-native environment; child migrants who migrated during the period of growth and maturation (0–18 yrs); and adult migrants who migrated after 18 years of age. Chest depth, FVC, and FEV1 measures were larger with increasing developmental exposure in both HAN migrants at LA and LAN migrants at HA. Developmental responses were similar between HAN and LAN groups. FVC and FEV1 measures were larger in HANs vs LANs born and raised at HA to suggest a genetic effect, but were similar in HANs and LANs born and raised at LA. The similarity of HAN and LAN groups at LA suggests that the genetic potential for larger lung volumes at HA depends upon developmental exposure to HA. Additional data for females (HANs at HA, n = 20, and LAN adult migrants to HA, n = 17) show similar differences as those shown between male HAN and LAN groups. Am. J. Hum. Biol. 11:383–395, 1999. © 1999 Wiley-Liss, Inc.     

Differences in prevalence of allergic sensitization in urban and rural school children.

BACKGROUND: Environmental factors are important causes of sensitization, even though the effect of specific pollutants and the interaction between pollution and aeroallergens are not completely known. PURPOSE: To evaluate whether the exposure to pollutants or to allergens is a more important contributing factor in causing sensitization. METHODS: A group of 312 children living in the city and a group of 225 children living in a rural area, ages 11 to 14, were studied. All subjects underwent a skin prick test. The pollen counts were performed in the two different areas during the peak of the pollen season. At the same time the levels of ozone and suspended particulates were measured. RESULTS: The students living in the rural area showed a significantly higher percentage of sensitization than those in the city (P = .046). Sensitization to pollen was more frequent in the rural area (P < .001) but pet sensitization was more frequent in the city. More rural area students were sensitive to multiple allergens (P = .034). Pollen levels were higher in the rural area (P = .001). Both ozone and suspended particulate levels were higher in the city (P = .001 and P < .001, respectively). CONCLUSIONS: The degree of pollen exposure is a larger contributing pathogenic factor in inducing sensitization than air pollution.     

The effect of forced expirations on mucociliary clearance in patients with chronic bronchitis and in healthy subjects

Animal studies have shown that frequent coughing may damage the mucociliary apparatus in flow-limiting segments of the central airways. To determine whether mucociliary clearance in humans is affected by repeated dynamic compression associated with forced expirations, we measured pulmonary deposition and mucociliary clearance for 2 h of inhaled [99Tcm]albumin. The subjects inhaled [99Tcm]albumin on 2 study days (randomized) using (A) slow inspirations and forced expirations, while inhalation using (B) forced inspirations and slow expirations served as control. The study was conducted using 10 patients with chronic hypersecretory/obstructive bronchitis and six normal subjects. We found that inhalation of [99Tcm]albumin by the two manoeuvres (A and B) resulted in similar patterns of aerosol deposition. There was no significant difference in retention of radioactivity in the central lung region at 1 h in the patients with chronic bronchitis after inhalation with manoeuvre A (102%) and with manoeuvre B (91.5%), or in the healthy subjects after manoeuvre A (74%) and manoeuvre B (77%). There was also no difference in the retention at 2 h or in overall mucociliary clearance in any of the groups. We conclude that dynamic compression in the central airways associated with forced expiration does not affect bronchial clearance in the airways of healthy subjects or in patients with chronic bronchitis.     

Association of hepatitis A virus infection with allergic sensitization in a population with high prevalence of hepatitis A virus exposure

BACKGROUND: An inverse association between allergic sensitization and markers of exposure to food-borne and orofecal infections (particularly hepatitis A virus, HAV) has been reported. The prevalence of HAV exposure and allergic sensitization vary widely in different areas, and vary along with age within a given area. AIM: To investigate the association between HAV exposure and allergic sensitization in adults from a mostly rural area of Spain. METHODS: An age-stratified random sample of 720 subjects was drawn from the population older than 18 years of A-Estrada, Spain. From 697 eligible subjects, 469 (67.2%, median age 54 years, range: 18-92) participated in the study. Positive skin prick tests to a panel of aeroallergens defined allergic sensitization. Positive serum HAV antibodies (assayed in 465 subjects) defined HAV exposure. RESULTS: The prevalence of HAV exposure was 83.6% (95% CI: 80.7-86.5). The prevalence of allergic sensitization was lower in subjects with HAV exposure than in patients without it (25.0%vs 40.0%, OR 0.44, 95% CI: 0.25-0.77, P=0.004), but this association became substantially altered after adjusting for age, which was closely linked to both allergic sensitization and HAV exposure (adjusted OR 1.15, 95% CI: 0.60-2.19, P=0.66). CONCLUSIONS: In a population with high prevalence of HAV exposure, no significant association between HAV exposure and allergic sensitization is observed after controlling for the confounding effect of age.     

The impact of climate and traffic-related NO2 on the prevalence of asthma and allergic rhinitis in Italy

BACKGROUND: Environmental factors are likely to be involved in explaining the wide geographical variation in asthma and atopic diseases that has been documented in many recent epidemiological studies. AIM: To evaluate to what extent climate and outdoor NO2 pollution can explain the geographical variation in the prevalence of asthma and allergic rhinitis, and to estimate the relative risk for exposure to different levels of these two factors. METHODS: The impact of climate and long-term exposure to nitrogen dioxide (NO2) pollution on asthma and allergic rhinitis was assessed in a cross-sectional study, carried out during 1998 to 2000 on young adults aged 20 to 44 years (n = 18 873), living in 13 areas from two different Italian climatic regions (subcontinental and Mediterranean). RESULTS: Mediterranean areas had a significantly higher prevalence of asthma-like symptoms (P < 0.001), higher annual mean temperature (16.2 degrees C vs. 12.9 degrees C), lower temperature range (16.0 C degrees vs. 22.1 degrees C) and lower NO2 levels (31.46 microg/m3 vs. 57.99 microg/m3) than subcontinental ones. Mediterranean climate was associated with an increased risk of wheeze (OR = 1.23; 95% CI 1.13 to 1.35), tightness in the chest (OR = 1.21; 95% CI 1.11 to 1.33), shortness of breath (OR = 1.21; 95% CI 1.08 to 1.36) and asthma attacks (OR = 1.19; 95% CI 1.07 to 1.31). After adjusting for climate, an increase of 18.3 microg/m3 in NO2 levels moderately increased the risk of asthma attacks (OR = 1.13; 95% CI 0.98 to 1.32), tightness in the chest (OR = 1.11; 95% CI 0.98 to 1.26) and wheeze (OR = 1.11; 95% CI 0.96 to 1.28). When the levels of outdoor NO2 exposure rose, the prevalence of allergic rhinitis increased significantly in the Mediterranean region (OR = 1.38; 95% CI 1.12 to 1.69), but not in the subcontinental one (OR = 1.03; 95% CI 0.83 to 1.28). CONCLUSION: Our results show that the prevalence of asthma increases when annual mean temperature increases and temperature range decreases. Furthermore, climate interacts with NO2 outdoor exposure, increasing the risk for allergic rhinitis in people exposed to high stable temperatures. A long-term role for the effect of traffic pollution on asthma is also suggested.     

Change in pulmonary function following empyemectomy and decortication in tuberculous and non-tuberculous chronic empyema thoracis

Chronic empyema thoracis results from various etiologies. Improvement in pulmonary function after empyemectomy and decortication has proved difficult to predict when the etiology of chronic empyema thoracis is tuberculosis. The purpose of this study was to confirm the changes in pulmonary function according to the etiology after an operation. Sixty-five patients were classified into two groups according to their etiology: Group A (tuberculous) and Group B (non-tuberculous), and they were retrospectively evaluated with regard to their forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), percentage of predicted normal value of FEV1 (% FEV1) and FVC (%FVC). Empyemectomy and decortication was performed for all the patients and the two groups were similar in age, gender and preoperative spirometric parameters. In Group A (n=41), the pre- and postoperative mean values were 2.31 L and 2.8 L in FEV1, 65.8% and 80.5% in %FEV1, 2.62 L and 2.55 L in VC, 61.9% and 71.8% in %VC, respectively. In Group B (n=24), the pre- and postoperative mean values were 2.13 L and 2.49 L in FEV1, 66.4% and 73.8% in %FEV1, 2.55 L and 2.95 L in FVC, 64.9% and 71.8% in %FVC, respectively. All the spirometric parameters improved significantly in both groups compared to their preoperative values. However, no significance was shown in the rate of increase of the spirometric parameters between the two groups. In conclusion, improvement of lung function is expected after empyemectomy and decortication, regardless of the etiology of the chronic empyema thoracis.     

SO2-induced bronchopathy decreases airway sensitization with intratracheal ovalbumin in the rat

We investigated in this study the effect of SO2-induced bronchopathy on airway sensitization to ovalbumin in the rat. Sprague-Dawley rats were immunized with a single intratracheal injection of ovalbumin (OA) 100 micrograms in 0.1 ml PBS or 0.1 ml Bordetella pertussis (BP) heat-killed vaccine (6.5 X 10(9) cells X ml-1). The rats were primed immediately after SO2 exposure (60 h, 200 ppm; group I, n = 16) and three months after exposure was achieved (group II, n = 24), then compared to a control group exposed to air (group III, n = 30). Airway sensitization was evaluated by the in vitro contractile response to antigen challenge using paired tracheal rings. Specific IgE level was determined with PCA reactions. No significant difference was found in the maximal contractile responses to carbamyl choline within and between each group. Excepted in animals of group III, OA alone was not found able to sensitize the airways. When OA was used in association with BP, sensitization of the airways occurred, but this occurrence was found to depend upon a previous SO2 exposure: 73.3% in group III, 41.7% in group II and 25% in group I were sensitized. In addition, only five animals (BP + OA injected rats of group III) displayed a PCA positive reaction. It is concluded that: 1) the concomitant intratracheal injection of BP with OA increased the occurrence of specific airway sensitization, 2) a previous chronic exposure to SO2 decreased the specific tracheal smooth muscle sensitization to intratracheal ovalbumin. This decrease persisted, although slighter, when immunization was done three months after the exposure to SO2 was stopped.