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Biomedical subjects

B Brotons

Publications and source records attributed to B Brotons.

5 recordsLinked to original sources
PubMed2000

Airway responsiveness to acetaldehyde in patients with asthma: relationship to methacholine responsiveness and peak expiratory flow variation.

BACKGROUND: Although airway hyperresponsiveness to inhaled acetaldehyde has been documented in Japanese patients with asthma, the response to this bronchoconstrictor agent has never been studied in Caucasians. OBJECTIVES: The objectives of the study were to determine differences in airway responsiveness to acetaldehyde between asthmatic and healthy subjects, and to examine the relationship between acetaldehyde responsiveness and the variability of peak expiratory flow (PEF). METHODS: The response to methacholine and acetaldehyde challenges was measured in 81 non-smoking adults (61 asthmatics and 20 normal controls). Subjects recorded PEF morning and evening for 14 days. The response to both bronchoconstrictor agents was measured by the PC20 (provocative concentration required to produce a 20% fall in FEV1). PEF variation was expressed as amplitude percentage mean, and as low percentage best (lowest PEF expressed as a percentage of the best PEF recorded). RESULTS: The two types of challenge yielded a similarly high level of sensitivity (100% for methacholine and 92% for acetaldehyde) and specificity (90 and 100%, respectively) to distinguish between asthma and controls. Asthmatic subjects were on average 265-fold less sensitive to acetaldehyde than to methacholine. PC20 acetaldehyde correlated weakly but significantly with both indices of PEF variation (amplitude percentage mean: rho = - 0.36, P = 0. 004; low percentage best: rho = 0.42, P = 0.001). CONCLUSIONS: These results indicate that airway hyperresponsiveness to acetaldehyde is a sensitive and specific indicator for separating asthmatic and normal subjects. Airway responsiveness to methacholine or acetaldehyde and PEF variation are not reflecting the same pathophysiological process in the airways.

Acetaldehyde↗
PubMed1994

[The prevalence of chronic obstructive pulmonary disease and asthma. A cross-sectional study].

Four hundred sixty-seven patients between 35 and 65 years of age were studied, all taken from a random sample of the population of Health Area 5 of the Valencian Community. Figures for respiratory symptoms, smoking, previous lung disease, professional activity and lung function were obtained through questionnaires and spirometry. The prevalence of asthma found was 2.78% (C.I. 2.76-2.79); chronic bronchitis was 4.07% (C.I. 2.37-5.77) and airflow limitation was 6.4% (C.I. 4.5-8.3). Smokers represented 33.2% of the sample. A significant association was found between the level of intensity of symptoms and lung function. There were no differences between smokers and non smokers with respect to FEV1%. An association between workplace exposure and spirometry was found only for FEV1/FVC%.

Adult↗
PubMed1991

[Contrast echocardiography in the diagnosis of severe hypoxemia associated with liver cirrhosis].

Severe hypoxemia is an uncommon feature of hepatic cirrhosis. Its major cause are intrapulmonary arteriovenous shunts, both due to direct arteriovenous communications and abnormally dilated pulmonary capillaries. In the present study, a case of cirrhosis associated with severe hypoxemia is reported. Contrast echocardiography showed pulmonary arteriovenous shunts, and low values of mixed venous blood (15% or less were obtained with the method of 100% oxygen breathing). These data suggest that the basic mechanism of hypoxemia, in this case, were capillary dilatations rather than true pulmonary arteriovenous anastomoses. The pathophysiological mechanisms of hypoxemia in cirrhosis are discussed, with emphasis on the present relevance of echocardiography for a full evaluation of these patients, particularly when liver transplantation is contemplated.

Aged↗