Renata Salatti Ferrari

Oxidative Stress and Lung Ischemia-Reperfusion Injury

Ischemia-reperfusion (IR) injury is directly related to the formation of reactive oxygen species (ROS), endothelial cell injury, increased vascular permeability, and the activation of neutrophils and platelets, cytokines, and the complement system. Several studies have confirmed the destructiveness of the toxic oxygen metabolites produced and their role in the pathophysiology of different processes, such as oxygen poisoning, inflammation, and ischemic injury. Due to the different degrees of tissue damage resulting from the process of ischemia and subsequent reperfusion, several studies in animal models have focused on the prevention of IR injury and methods of lung protection. Lung IR injury has clinical relevance in the setting of lung transplantation and cardiopulmonary bypass, for which the consequences of IR injury may be devastating in critically ill patients.

Relationship Between MELD Severity Score and the Distance Walked and Respiratory Muscle Strength in Candidates for Liver Transplantation

The model end-stage liver disease (MELD) severity scoring system is used in the allocation of organs for liver transplantation. However, there is no evidence of its relationship with the functionality and respiratory muscle strength in these patients. The aim of this study was to analyze the correlation of MELD with distance walked and respiratory muscle strength in patients awaiting liver transplantation. We performed a cross-sectional analysis of 24 individuals (16 male and 8 female) with mean age of 51.8 +/- 10.4 years. The MELD score inversely correlated with the 6-minute walking test (6MWT) (r = -0.85; P < .001) and with the maximal inspiratory pressure (MIP) (r = -0.69; P < .001). In addition, there was a correlation between 6MWT and MIP (r = 0.77; P < .001). Thus, MELD scores can be considered to be effective tools to predict the functional capacity and respiratory muscle strength in candidates for liver transplantation.

Oxidative Stress and Pulmonary Changes in Experimental Liver Cirrhosis

The use of carbon tetrachloride (CCl4) in rats is an experimental model of hepatic tissue damage; which leads to fibrosis, and at the long term, cirrhosis. Cirrhosis is the consequence of progressive continued liver damage, it may be reversible when the damaging noxae have been withdrawn. The aim of this study is to evaluate the changes caused by cirrhosis in lung and liver, through the experimental model of intraperitoneal CCI4 administration. We used 18 male Wistar rats divided into three groups: control (CO) and two groups divided by the time of cirrhosis induction by CCI4: G1 (11 weeks), G2 (16 weeks). We found significant increase of transaminase levels and lipid peroxidation (TBARS) in liver and lung tissue and also increased antioxidant enzymes SOD and CAT, as well as the expression of TNF-α and IL-1β in the lung of cirrhotic animals. We observed changes in gas exchange in both cirrhotic groups. We can conclude that our model reproduces a model of liver cirrhosis, which causes alterations in the pulmonary system that leads to changes in gas exchange and size of pulmonary vessels.

LUNG AND LIVER CHANGES DUE TO THE INDUCTION OF CIRRHOSIS IN TWO EXPERIMENTAL MODELS

CONTEXT To evaluate lung and liver changes in two experimental models using intraperitoneal carbon tetrachloride (CCl4) and bile duct ligation (BDL). methods: Twenty-four male Wistar rats were divided into a control group (CO) and an experimental group (EX). We evaluated the liver transaminases (AST, ALT, AP), arterial blood gases (PaO2, PCO2 and SpO2) and lipid peroxidation by TBARS (substances that react to thiobarbituric acid) and chemiluminescence. We also evaluated the antioxidant enzyme superoxide dismutase (SOD) and histology of lung tissue and liver. RESULTS There were significant differences in AST, ALT, ALP and PaO2 between CO group and EX group (P<0.05). The levels of TBARS, chemiluminescence and activity of enzyme superoxide dismutase were increased to different degrees in the CCl4 groups: CO and in the BDL -EX (P<0.05, respectively). In the lung histology, an increase in the wall thickness of the pulmonary artery and a diameter reduction in the CCl4 animal model were observed: comparing CO group with EX group, we observed a reduction in thickness and an increase in the diameter of the artery wall lung. CONCLUSION Both experimental models have caused liver damage and alterations in the artery wall that are associated with major changes in pulmonary gas exchange.

Assessment of functional capacity and pulmonary in pediatrics patients renal transplantation

INTRODUCTION Pediatric patients undergoing kidney transplantation can present changes in pulmonary function and functional capacity for exercise. OBJECTIVE To evaluate the functional capacity and pulmonary function in children and adolescents undergoing kidney transplantation. METHOD Children and adolescents aged six to 18 years of age were evaluated in Outpatient Clinic of Nephrology, Hospital da Criança Santo Antônio, Santa Casa de Porto Alegre, RS, Brazil in period the june of 2010 the march of 2011. Pulmonary capacity was assessed by spirometry and maximal respiratory pressures and functional capacity through 6-minute walk test (6MWT). RESULTS The sample comprised 25 patients, 14 (56%) males with a mean age of 13.5 ± 3.3 years. From, 19 (76%) underwent dialysis before transplantation. Mean forced vital capacity (FVC) was 97.91 + 24.32% and forced expiratory volume in one second (FEV1) 100.53 + 17.66% from predicted value. In the 6MWT, the patients walked 229.14 meters less than predicted (p < 0.001). The maximum inspiratory pressure (MIP) was significantly lower than predicted, and the difference in cmH₂O -24.63 (p = 0.03), as the maximum expiratory pressure (MEP), with a difference of 49.27 cmH₂O (p < 0.001). By correlating, functional capacity, spirometry and maximal respiratory pressures, find an association between FVC and 6MWT (r = 0.52, p = 0.01) and FVC and MIP (r = 0.54, p = 0.01). CONCLUSION Reduced functional capacity and maximum respiratory pressures were diagnosed in a small cohort of pediatric patients after kidney transplantation. Better the functional capacity and PiMáx better the FVC.