Exposure to cigarette smoke during pregnancy causes redox imbalance and histological damage in lung tissue of neonatal mice.

Smoking during pregnancy is directly associated with numerous serious conditions, such as premature birth, low birth weight, and perinatal mortality. We quantitatively evaluated histological inflammatory alterations, oxidative damage by lipid peroxidation, the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in the lungs of mice exposed to cigarette smoke during pregnancy. Eight female and four male mice were mated for five days. Pregnant female mice were randomly allocated to the control group or to the cigarette smoke group (n = 8) in which they were exposed to 12 cigarettes per day in an exposure chamber, three times a day for 21 days. The control group (CG; n = 8) was kept in the exposure chamber for the same duration, but without exposure to cigarette smoke. Six newborn mice from both groups were weighed 24 hours after birth and then euthanized. Lung tissue was collected and subjected to histomorphometric and biochemical analyses. The cigarette smoke group showed a significant reduction in snout-vent length compared to the control group. Histomorphometric analysis indicated increased alveolar septal thickness and a larger alveolar lumen in mice exposed to cigarette smoke than in mice in the control group. We observed increased alveolar inflammatory infiltrate, decreased SOD activity, and significantly higher oxidative damage in the cigarette smoke group. Our data indicate that cigarette smoke exposure during pregnancy decreases body length at birth, changes lung tissue, and causes redox imbalance and histological damage in newborn mice.

Correlação entre a pressão expiratória máxima (pemáx) e pico de fluxo expiratório máximo (pfe) em indivíduos saudáveis / Correlation between maximal expiratory pressure (mpe) and maximal expiratory flow peak (mefp) in healthy individuals

Introdução: A prova de função pulmonar é um recurso que tem colaborado com a validação científica da fisioterapia respiratória. Ela é capaz de estimar, entre outras variáveis, as alterações dos volumes e capacidades pulmonares, e/ ou as alterações da força dos músculos respiratórios. A mensuração da força é realizada através do manovacuômetro, no qual se obtém a pressão expiratória máxima (PEmáx.). Outra forma de avaliar a função pulmonar é a medida do pico de fluxo expiratório (PFE). Objetivos: Investigar a correlação entre a PEmáx. e PFE, em indivíduos saudáveis. Métodos: O estudo foi realizado na Universidade Severino Sombra. Oitenta e um voluntários de ambos os sexos, 55 do sexo feminino (22,69 ± 0,41 anos), e 26 do sexo masculino (23,11 ± 3,51 anos) participaram deste estudo. Um questionário respiratório foi aplicado para investigar parâmetros clínicos. Todos os indivíduos realizaram exame de manovacuometria e medidor de PFE, em posição ortostática. Os dados foram expressos como média ± erro padrão da média. Resultados: Uma correlação positiva foi encontrada entre a PEmáx. e PFE (r = 0,43; r2 = 0,18, p <0,001). Foi estimada a equação de regressão linear (PFE = 2,93 + 148,07 x PEmáx.), e os valores normais estimados foram apresentados em uma tabela. Conclusões: Este estudo mostra a influência da força dos músculos expiratórios no PFE em vias aéreas, e sugeriu uma equação para estimar a função ventilatória normal, na prática clínica.

Introduction: The pulmonary function is a feature that has collaborated with the scientific validation of respiratory therapy. It is able to estimate, among other variables, changes in lung volumes and capacities, and/or changes in respiratory muscle strength. The measurement of force is obtained by the manometer, through which one can obtain the maximum expiratory pressure (MEP). Another way to assess lung function is by the measurement of expiratory flow peak (EFP). Objectives: To investigate the correlation between MEP and EFP in healthy individuals (patients). Methods: This study was developed at the Severino Sombra University. Eighty-one volunteers of both sexes, 55 females (22.69 ± 0.41 years) and 26 males (23.11 ± 3.51 years) participated in this study. A respiratory questionnaire was applied to investigate clinical parameters. All individuals underwent manometer examination and flow peak measurement, in the standing position. Data were expressed as mean ± standard error of mean. Results: A positive correlation was found between MEP and EFP (r = 0.43, r2 = 0.18, p <0.001). The linear regression equation was estimated (PEF = 148.07 + 2.93 x MEP) and normal values were presented in a table. Conclusions: This study shows the influence of expiratory muscle strength in EFP in the airways, and suggested an equation to estimate the normal ventilating function in clinical practice.