Pre-eclampsia (PE) is a hypertensive disorder of pregnancy and has been associated with placental growth restriction. The pre-eclamptic placenta releases free radicals to maternal circulation, thus increasing oxidative stress. An impaired redox state leads to reduction in circulating nitric oxide (NO) levels and activation of extracellular matrix metalloproteinases (MMPs). However, activation of MMPs induced by oxidative stress is still unclear in PE. Antioxidant effects have been demonstrated with the use of pravastatin. Therefore, we hypothesized that pravastatin protects against oxidative stress-induced activation of MMPs in a rat model of PE. The animals were divided into four groups: normotensive pregnant rats (Norm-Preg); pregnant rats treated with pravastatin (Norm-Preg + Prava); hypertensive pregnant rats (HTN-Preg); and hypertensive pregnant rats treated with pravastatin (HTN-Preg + Prava). The deoxycorticosterone acetate (DOCA) and sodium chloride (DOCA-salt) model was used to induce hypertension in pregnancy. Blood pressure, and fetal and placental parameters were recorded. The gelatinolytic activity of MMPs, NO metabolites and lipid peroxide levels were also determined. Endothelium function was also examined. Pravastatin attenuated maternal hypertension, prevented placental weight loss, increased NO metabolites, inhibited increases in lipid peroxide levels, and reduced the activity of MMP-2, and these effects were observed along with enhanced endothelium-derived NO-dependent vasodilation. The present results provide evidence that pravastatin protects against activation of MMP-2 induced by oxidative stress in pre-eclamptic rats. These findings may also involve improvement in endothelial function related to NO and antihypertensive effects of pravastatin, thus suggesting pravastatin as a therapeutic intervention for PE.
Volatile anesthetics may cause vascular dysfunction; however, underlying effects are unclear. The aim of the present study was to investigate whether sevoflurane and isoflurane affect vascular function, nitric oxide (NO) bioavailability, and biomarkers of oxidative stress and inflammation. Wistar rats were divided into three experimental groups: Not anesthetized (control group) or submitted to anesthesia with isoflurane (Iso group) or sevoflurane (Sevo group). Hemodynamic parameters were monitored during anesthesia, and blood gas values and biochemical determinants were analyzed. Isometric contractions were recorded in aortic rings. Vasoconstriction induced by potassium chloride (KCl) and phenylephrine (Phe) were measured. No differences in hemodynamic parameters and blood gasses variables were observed. Impaired KCl and Phe‐induced contractions were observed in endothelium‐intact aorta of Sevo compared to Iso and Control groups. Redox imbalance was found in Sevo and Iso groups. Reduced NO bioavailability and increased activity of matrix metalloproteinase 2 (MMP‐2) were observed in Sevo, but not in the Iso group. While reduced IL‐10 and IL‐1β were observed in Sevo, increases in IL‐1β in the Iso group were found. Sevoflurane, but not isoflurane, anesthesia impairs vasocontraction, and reduced NO and cytokines and increased MMP‐2 activity may be involved in vascular dysfunction after sevoflurane anesthesia.
Lead (Pb) reduces NO bioavailability, impairs the antioxidant system, and increases the generation of reactive oxygen species (ROS). Pb‐induced oxidative stress may be responsible for the associated endothelial dysfunction. Sildenafil has shown nitric oxide (NO)‐independent action, including antioxidant effects. Therefore, we examined the effects of sildenafil on oxidative stress, reductions of NO and endothelial dysfunction in Pb‐induced hypertension. Wistar rats were distributed into three groups: Pb, Pb + sildenafil and Sham. Blood pressure and endothelium‐dependent vascular function were recorded. We also examined biochemical determinants of lipid peroxidation and antioxidant function. ROS levels, NO metabolites and NO levels in human umbilical vein endothelial cells (HUVECs) were also evaluated. Sildenafil prevents impairment of endothelium‐dependent NO‐mediated vasodilation and attenuates Pb‐induced hypertension, reduces ROS formation, enhances superoxide dismutase (SOD) activity and antioxidant capacity in plasma and increases NO metabolites in plasma and HUVECs culture supernatants, while no changes were found on measurement of NO released from HUVECs incubated with plasma of the Pb and Pb + sildenafil groups compared with the sham group. In conclusion, sildenafil protects against ROS‐mediated inactivation of NO, thus preventing endothelial dysfunction and attenuating Pb‐induced hypertension, possibly through antioxidant effects.
Introdução: O vírus Influenza, um dos maiores desafios de saúde pública do mundo, causa epidemias anuais recorrentes com infecções respiratórias agudas que apresentam manifestações que variam de quadros leves a complicações fatais. Objetivos: Caracterizar o perfil epidemiológico de pacientes hospitalizados com Síndrome Respiratória Aguda Grave (SRAG) por Influenza na região Noroeste Paulista do Brasil. Adicionalmente, verificar a sazonalidade da gripe e a prevalência do vírus Influenza na população desta região. Métodos: estudo transversal retrospectivo com levantamento de dados de exames de pacientes internados em hospitais da região noroeste do estado de São Paulo, Brasil, no período de janeiro a dezembro de 2018. Resultados: Foram analisados os resultados de 1712 amostras, das quais, 430 (25%) foram positivas para o vírus influenza, destas 417 (97%) foram positivas para Influenza A e 13 (3%) positivas para Influenza B. Com relação à faixa etária, 53,7% das amostras eram de pacientes pertencentes a grupos de risco, sendo 418 amostras (24,4%) de idosos acima de 60 anos e 501 (29,3%) amostras de crianças menores de cinco anos. Cerca de 89% das amostras positivas foram provenientes de pacientes não vacinados. Conclusão: Concluiu-se que houve predomínio do vírus Influenza A em idosos e crianças, ambos considerados importantes grupos de risco. Além disso, foi evidenciada a importância da vacinação para a redução dos casos positivos. A detecção e identificação precoce possibilitam o tratamento correto, a diminuição do tempo de internação e seus custos e minimizam os riscos de evolução para casos graves e óbito. Cabe ressaltar a importância de medidas de prevenção que devem ser mantidas e fortalecidas, principalmente, a vacinação.
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