Development of different degrees of elastase-induced emphysema in mice: a randomized controlled experimental study

Introduction: Mouse models of emphysema are important tools for testing different therapeutic strategies. The aim of this study was to develop a mouse model of emphysema induced by different doses of elastase in order to produce different degrees of severity. Methods: Thirty female mice (C57BL/6) were used in this study. Different doses of porcine pancreatic elastase were administered intratracheally once a week for four weeks, as follows: 0.1 U (n=8), 0.15 U (n=7), and 0.2 U (n=7). Control mice (n=8) received 50 microL of sterile saline solution intratracheally. Lung mechanics were analyzed by plethysmography. Mean linear intercept and volume fraction occupied by collagen and elastic fibers were determined. Results: An increase in lung resistance was observed with 0.2 U of elastase [median (P-25-P75): 2.02 (1.67; 2.34) cmH2O.s/mL], as well as a decrease in tidal volume and minute ventilation. Peak expiratory flow increased significantly in the groups treated with 0.15 U and 0.2 U of elastase. Mean linear intercept was higher with 0.15 U and 0.2 U of elastase, with destruction of alveolar walls [median (P-25-P75): 30.31 (26.65-43.13) microm and 49.49 (31.67-57.71) microm respectively]. The volume fraction occupied by collagen and elastic fibers was lower in the group receiving 0.2 U of elastase. Conclusion: Four intratracheal instillations of 0.2 U of elastase once a week induced changes in lung function and histology, producing an experimental model of severe pulmonary emphysema, whereas 0.15 U resulted in only histological changes.

Gênero e manifestação de stress em hipertensos / Gender and the manifestation of stess in patients hypertensive

Embora estudos sustentem maior vulnerabilidade ao stress na população feminina, há escassez de dados sobre a população de hipertensos. Realizou-se um estudo transversal para verificar a diferença na prevalência de sintomas de stress entre os gêneros, por meio da aplicação do Inventário de Sintomas de Stress de Lipp e de um questionário de dados sociodemográficos. Os resultados não mostram diferença estatisticamente significativa concernente à presença de sintomas de stress entre as amostras masculina (n=33) e feminina (n=70). Contudo, mais homens apresentaram escores na fase de resistência (60,6 por cento), enquanto a fase de quase-exaustão preponderou entre as mulheres: 41,4 por cento versus 15,2 por cento dos homens. Considerando sintomas físicos e psicológicos no geral, independente de predominância de fase, as mulheres relataram ter significativamente mais sintomas psicológicos de stress nos escores referentes às fases de resistência, quase-exaustão e à fase de exaustão (p<0,05). Esses achados podem auxiliar no planejamento de abordagens de controle de stress.

Even though studies support the idea of greater vulnerability to stress in the female population, there is a dearth of studies related to hypertensive patients. A cross-sectional study was conducted with the aim of verifying the difference in the prevalence of stress symptoms in a male and female sample of hypertensive patients, using Lipp's Adult Stress Symptoms Inventory and a socio-demographic questionnaire. There was no statistically significant difference in respect of the presence of stress symptoms between males (n=33) and females (n=70). However, men obtained higher scores in the resistance phase (60.6 percent), while women obtained higher scores in the near-exhaustion phase (41.4 percent versus 15.2 percent of men). Considering overall physical and psychological symptoms, irrespective of the predominant phase, women reported significantly higher psychological stress symptoms than men in terms of the scores in the resistance and near-exhaustion phases, as well as the scores in the exhaustion phase (p<0.05). These findings may help in the planning of stress-management strategies.