Daniel Silveira Serra

Changes in rat respiratory system produced by exposure to exhaust gases of combustion of glycerol

The combustion of residual glycerol to generate heat in industrial processes has been suggested as a cost-effective solution for disposal of this environmental liability. Thus, we investigated the effects of exposure to the exhaust gases of glycerol combustion in the rat respiratory system. We used 2 rats groups, one exposed to the exhaust gases from glycerol combustion (Glycerol), and the other exposed to ambient air (Control). Exposure occurred 5h a day, 5days a week for 13 weeks. We observed statistically changes in all parameters of respiratory system mechanics in vivo. This results was supported by histological analysis and morphometric data, confirming narrower airways and lung parenchimal changes. Variables related to airway resistance (ΔRN) and elastic properties of the tissue (ΔH), increased after challenge with methacholine. Finally, analysis of lung tissue micromechanics showed statistically increases in all parameters (R, E and hysteresivity). In conclusion, exhaust gases from glycerol combustion were harmful to the respiratory system.

Essential oil of Croton Zehntneri attenuates lung injury in the OVA-induced asthma model

ABSTRACT Objective: Croton zehntneri Pax et Hoffm. is a Euphorbiaceae species, popularly known as “canela de cunhã,” a native plant of northeastern Brazil, whose essential oil (EOCZ) shows relatively specific myorelaxant action for the smooth muscle of the airways and in the respiratory tract. Based on this information, EOCZ figures as a candidate for testing in the treatment of asthma, and the present study investigated the benefits of using EOCZ in an ovalbumin-induced asthma model. Methods: 48 male BALB/c mice were divided into six groups (n = 8). In the ST, SO100, and SO300 groups, mice were sensitized and challenged with saline, and then treated with 200 µL of 0.1% Tween 80, 100 mg/kg EOCZ and 300 mg/kg EOCZ, respectively. In the OT, OO100, and OO300 groups, mice were sensitized and challenged with OVA, and then treated with 200 µL of 0.1% Tween 80, 100 mg/kg EOCZ and 300 mg/kg EOCZ, respectively. Results: Our results demonstrated significant changes in all respiratory mechanics variables analyzed between the OO300 and OT groups demonstrating the effectiveness of EOCZ to attenuate the OVA-induced lung injury. In addition, the use of EOCZ at a dose of 300 mg/kg showed an antioxidant effect and decreased inflammatory cells in the pulmonary parenchyma. In conclusion, our results demonstrated that EOCZ was able to improve the lesion in the respiratory system of mice subjected to OVA-induced asthma. Conclusions: The antioxidant action of EOCZ was likely the main mechanism of action in the reversal of this lesion, so more tests should be performed for its confirmation.

Pulmonary mechanic and lung histology induced by Crotalus durissus cascavella snake venom

ABSTRACT This study have analyzed the pulmonary function in an experimental model of acute lung injury, induced by the Crotalus durissus cascavella venom (C. d. cascavella) (3.0 &mgr;g/kg ‐ i.p), in pulmonary mechanic and histology at 1 h, 3 h, 6 h, 12 h and 24 h after inoculation. The C. d. cascavella venom led to an increase in Newtonian Resistance (Symbol), Tissue Resistance (Symbol) and Tissue Elastance (Symbol) in all groups when compared to the control, particularly at 12 h and 24 h. The Histeresivity (Symbol) increased 6 h, 12 h and 24 h after inoculation. There was a decrease in Static Compliance (Symbol) at 6 h, 12 h and 24 h and inspiratory capacity (Symbol) at 3 h, 6 h, 12 h and 24 h. C. d. cascavella venom showed significant morphological changes such as atelectasis, emphysema, hemorrhage, polymorphonuclear inflammatory infiltrate, edema and congestion. After a challenge with methacholine (MCh), Symbol demonstrated significant changes at 6, 12 and 24 h. This venom caused mechanical and histopathological changes in the lung tissue; however, its mechanisms of action need further studies in order to better elucidate the morphofunctional lesions. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. HIGHLIGHTSC. d. cascavella venom increased Newtonian resistance, tissue resistance, tissue elastance and histeresivity in rat lungs.C. d. cascavella venom reduced static compliance and inspiratory capacity in rat lungs.C. d. cascavella venom induced morphological changes in the lung tissue.

Respiratory System of Rats Exposed to Pollutants arising out of Heating Residual Glycerol

Biofuels, such as biodiesel are renewable alternatives and environmentally safe fossil fuels. In the production of biodiesel, about 10% of the total volume is residual glycerol. This residual glycerol has impurities that prevent their direct use. Thus, it is important to search for alternatives to the direct use of such environmental liabilities. His direct combustion appears as a very promising route. Among the steps for using the residual glycerol as a fuel, no heating, with potential to generate pollutants whose effects on health are poorly investigated. This paper presents to study the effects of vapors from the residual glycerol heating in the respiratory system of rats. The animals were exposed to glycerol heating gas for 5 hours. As a result, an increase in the parameters of tissue elastance (H) and tissue resistance (G) of animals exposed to gases. Our results demonstrate that, despite the short period of exposure, there are changes in parameters related to lung tissue (G, H and CST), proving the harmful effect on the respiratory system of mice exposed to pollutants from the residual glycerol heating. This study can be used as reference works that intend to use the residual glycerol as fuel furnaces or boilers.

Análise da função pulmonar e estrutura micromecânica após 14 dias de restrição de movimento em ratas

A imobilizacao e uma condicao que compromete diversos segmentos e sistemas orgânicos, inclusive o sistema respiratorio, levando a alteracoes estruturais e funcionais. O objetivo deste estudo foi analisar a funcao pulmonar e estrutura micromecânica apos 14 dias de restricao de movimento de ratas. Foram utilizados catorze ratas Wistar com massa corporal entre 210 g±50 g, distribuidas em dois grupos, compostos por (n=7) cada grupo: Controle (C) e Imobilizado (I). O procedimento de imobilizacao envolveu abdomen (e ultimas costelas), pelve, quadril e joelho em extensao, alem de tornozelo em flexao plantar, por duas semanas. Apos esse periodo de imobilizacao, foi realizada a analise da funcao pulmonar por ventilador mecânico para pequenos animais (flexiVent) e manobras de recrutamento alveolar (MR). E, posteriormente, foram retiradas tiras do pulmao de cada animal para analisar a micromecânica pulmonar. Para a analise estatistica, utilizou-se o teste t nao pareado com significância estatistica (p<0,05), expresso como media±erro padrao da media. O grupo I apresentou mudancas significantes nos parâmetros da resistencia das vias aereas (RN) pre-MR(C=0,067±0,003 cmH2O.s/mL, I=0,095±0,004 cmH2O.s/mL, p<0,05) e histerisividade (η) pre-MR(C=0,203±0,004 cmH2O.s/mL, I=0,248±0,013 cmH2O.s/mL, p<0,05), que retornaram a seus valores de normalidade pos-MR, considerando-se RN pos-MR (C=0,064±0,003 cmH2O.s/mL, I=0,065±0,004 cmH2O.s/mL, p<0,05) e η (C=0,209±0,005 cmH2O.s/mL, I=0,214±0,007 cmH2O.s/mL, p<0,05). Conclui-se que a imobilizacao acarreta alteracoes funcionais reversiveis no sistema respiratorio apos 14 dias de restricao de movimento, o que e evidenciado pela reducao de RN e η pos-MR.

Analysis of pulmonary function and micromechanics structure after 14 days of movement restriction in female rats

A imobilizacao e uma condicao que compromete diversos segmentos e sistemas orgânicos, inclusive o sistema respiratorio, levando a alteracoes estruturais e funcionais. O objetivo deste estudo foi analisar a funcao pulmonar e estrutura micromecânica apos 14 dias de restricao de movimento de ratas. Foram utilizados catorze ratas Wistar com massa corporal entre 210 g±50 g, distribuidas em dois grupos, compostos por (n=7) cada grupo: Controle (C) e Imobilizado (I). O procedimento de imobilizacao envolveu abdomen (e ultimas costelas), pelve, quadril e joelho em extensao, alem de tornozelo em flexao plantar, por duas semanas. Apos esse periodo de imobilizacao, foi realizada a analise da funcao pulmonar por ventilador mecânico para pequenos animais (flexiVent) e manobras de recrutamento alveolar (MR). E, posteriormente, foram retiradas tiras do pulmao de cada animal para analisar a micromecânica pulmonar. Para a analise estatistica, utilizou-se o teste t nao pareado com significância estatistica (p<0,05), expresso como media±erro padrao da media. O grupo I apresentou mudancas significantes nos parâmetros da resistencia das vias aereas (RN) pre-MR(C=0,067±0,003 cmH2O.s/mL, I=0,095±0,004 cmH2O.s/mL, p<0,05) e histerisividade (η) pre-MR(C=0,203±0,004 cmH2O.s/mL, I=0,248±0,013 cmH2O.s/mL, p<0,05), que retornaram a seus valores de normalidade pos-MR, considerando-se RN pos-MR (C=0,064±0,003 cmH2O.s/mL, I=0,065±0,004 cmH2O.s/mL, p<0,05) e η (C=0,209±0,005 cmH2O.s/mL, I=0,214±0,007 cmH2O.s/mL, p<0,05). Conclui-se que a imobilizacao acarreta alteracoes funcionais reversiveis no sistema respiratorio apos 14 dias de restricao de movimento, o que e evidenciado pela reducao de RN e η pos-MR.

Análisis de la función pulmonar y estructura micromecanica después de 14 días de restricción en el movimiento en ratas

A imobilizacao e uma condicao que compromete diversos segmentos e sistemas orgânicos, inclusive o sistema respiratorio, levando a alteracoes estruturais e funcionais. O objetivo deste estudo foi analisar a funcao pulmonar e estrutura micromecânica apos 14 dias de restricao de movimento de ratas. Foram utilizados catorze ratas Wistar com massa corporal entre 210 g±50 g, distribuidas em dois grupos, compostos por (n=7) cada grupo: Controle (C) e Imobilizado (I). O procedimento de imobilizacao envolveu abdomen (e ultimas costelas), pelve, quadril e joelho em extensao, alem de tornozelo em flexao plantar, por duas semanas. Apos esse periodo de imobilizacao, foi realizada a analise da funcao pulmonar por ventilador mecânico para pequenos animais (flexiVent) e manobras de recrutamento alveolar (MR). E, posteriormente, foram retiradas tiras do pulmao de cada animal para analisar a micromecânica pulmonar. Para a analise estatistica, utilizou-se o teste t nao pareado com significância estatistica (p<0,05), expresso como media±erro padrao da media. O grupo I apresentou mudancas significantes nos parâmetros da resistencia das vias aereas (RN) pre-MR(C=0,067±0,003 cmH2O.s/mL, I=0,095±0,004 cmH2O.s/mL, p<0,05) e histerisividade (η) pre-MR(C=0,203±0,004 cmH2O.s/mL, I=0,248±0,013 cmH2O.s/mL, p<0,05), que retornaram a seus valores de normalidade pos-MR, considerando-se RN pos-MR (C=0,064±0,003 cmH2O.s/mL, I=0,065±0,004 cmH2O.s/mL, p<0,05) e η (C=0,209±0,005 cmH2O.s/mL, I=0,214±0,007 cmH2O.s/mL, p<0,05). Conclui-se que a imobilizacao acarreta alteracoes funcionais reversiveis no sistema respiratorio apos 14 dias de restricao de movimento, o que e evidenciado pela reducao de RN e η pos-MR.

Changes of respiratory system in mice exposed to PM4.0 or TSP from exhaust gases of combustion of cashew nut shell

Air pollution is a topic discussed all over the world and the search for alternatives to reduce it is of great interest to many researchers. The use of alternative energy sources and biofuels seems to be the environmentally safer solution. In this work, the deleterious effects on the respiratory system of mice exposed to PM4.0 or TSP, present in exhaust gases from the combustion of CNS were investigated, through data from respiratory system mechanics, oxidative stress, histopathology and morphometry of the parenchyma pulmonary. The results show changes in all variables of respiratory system mechanics, in oxidative stress, the histopathological analysis and lung morphometry. The results provide experimental support for epidemiological observations of association between effects on the respiratory system and exposure to PM4.0 or TSP from CNS combustion exhaust gases, even at acute exposure. It can serve as a basis for regulation or adjustment of environmental laws that control the emissions of these gases.