55 research outputs found
Preditores ecocardiográficos de remodelação ventricular após o infarto agudo do miocárdio em ratos
Roles of the Taql and Bsml vitamin D receptor gene polymorphisms in hospital mortality of burn patients
OBJECTIVE: The aim of this study was to evaluate the roles of the Taql and Bsml vitamin D receptor gene polymorphisms in hospital mortality of burn patients. METHODS: In total, 105 consecutive burn injury patients over 18 years in age who were admitted to the Burn Unit of Bauru State Hospital from January to December 2013 were prospectively evaluated. Upon admission, patient demographic information was recorded and a blood sample was taken for biochemical analysis to identify the presence of the Taql(rs731236) and Bsml(rs1544410) polymorphisms. All of the patients were followed over their hospital stay and mortality was recorded. RESULTS: Eighteen of the patients did not sign the informed consent form, and there were technical problems with genotype analysis for 7 of the patients. Thus, 80 patients (mean age, 42.5±16.1 years) were included in the final analysis. In total, 60% of the patients were male, and 16.3% died during the hospital stay. The genotype frequencies for the Taql polymorphism were 51.25% TT, 41.25% TC and 7.50% CC; for the Bsml polymorphism, they were 51.25% GG, 42.50% GA and 6.25% AA. In logistic regression analysis, after adjustments for age, gender and total body surface burn area, there were no associations between the Taql (OR: 1.575; CI95%: 0.148-16.745; p=0.706) or Bsml (OR: 1.309; CI95%: 0.128-13.430; p=0.821) polymorphisms and mortality for the burn patients. CONCLUSIONS: Our results suggest that the Taql and Bsml vitamin D receptor gene polymorphisms are not associated with hospital mortality of burn patients
Periostin as a modulator of chronic cardiac remodeling after myocardial infarction
OBJECTIVE: After acute myocardial infarction, during the cardiac repair phase, periostin is released into the infarct and activates signaling pathways that are essential for the reparative process. However, the role of periostin in chronic cardiac remodeling after myocardial infarction remains to be elucidated. Therefore, the objective of this study was to investigate the relationship between tissue periostin and cardiac variables in the chronic cardiac remodeling induced by myocardial infarction. METHODS: Male Wistar rats were assigned to 2 groups: a simulated surgery group (SHAM; n = 8) and a myocardial infarction group (myocardial infarction; n = 13). After 3 months, morphological, functional and biochemical analyses were performed. The data are expressed as means±SD or medians (including the lower and upper quartiles). RESULTS: Myocardial infarctions induced increased left ventricular diastolic and systolic areas associated with a decreased fractional area change and a posterior wall shortening velocity. With regard to the extracellular matrix variables, the myocardial infarction group presented with higher values of periostin and types I and III collagen and higher interstitial collagen volume fractions and myocardial hydroxyproline concentrations. In addition, periostin was positively correlated with type III collagen levels (r = 0.673, p = 0.029) and diastolic (r = 0.678, p = 0.036) and systolic (r = 0.795, p = 0.006) left ventricular areas. Considering the relationship between periostin and the cardiac function variables, periostin was inversely correlated with both the fractional area change (r = -0.783, p = 0.008) and the posterior wall shortening velocity (r = -0.767, p = 0.012). CONCLUSIONS: Periostin might be a modulator of deleterious cardiac remodeling in the chronic phase after myocardial infarction in rats
Zinc Supplementation Attenuates Cardiac Remodeling After Experimental Myocardial Infarction
Background/Aims: The objective of our study was to evaluate the effects of zinc supplementation on cardiac remodeling following acute myocardial infarction in rats. Methods: Animals were subdivided into 4 groups and observed for 3 months: 1) Sham Control; 2) Sham Zinc: Sham animals receiving zinc supplementation; 3) Infarction Control; 4) Infarction Zinc. After the followup period, we studied hypertrophy and ventricular geometry, functional alterations in vivo and in vitro, changes related to collagen, oxidative stress, and inflammation, assessed by echocardiogram, isolated heart study, western blot, flow cytometer, morphometry, and spectrophotometry. Results: Infarction induced a significant worsening of the functional variables. On the other hand, zinc attenuated both systolic and diastolic cardiac dysfunction induced by infarction. Considering the infarct size, there was no difference between the groups. Catalase and superoxide dismutase decreased in infarcted animals, and zinc increased its activity. We found higher expression of collagens I and III in infarcted animals, but there was no effect of zinc supplementation. Likewise, infarcted animals had higher levels of IL-10, but without zinc interference. Nrf-2 values were not different among the groups. Infarction increased the amount of Treg cells in the spleen as well as the amount of total lymphocytes. Zinc increased the amount of CD4+ in infarcted animals, but we did not observe effects in relation to Treg cells. Conclusion: zinc attenuates cardiac remodeling after infarction in rats; this effect is associated with modulation of antioxidant enzymes, but without the involvement of collagens I and III, Nrf-2, IL-10, and Treg cells
Cardiac Remodeling: Concepts, Clinical Impact, Pathophysiological Mechanisms and Pharmacologic Treatment
Abstract Cardiac remodeling is defined as a group of molecular, cellular and interstitial changes that manifest clinically as changes in size, mass, geometry and function of the heart after injury. The process results in poor prognosis because of its association with ventricular dysfunction and malignant arrhythmias. Here, we discuss the concepts and clinical implications of cardiac remodeling, and the pathophysiological role of different factors, including cell death, energy metabolism, oxidative stress, inflammation, collagen, contractile proteins, calcium transport, geometry and neurohormonal activation. Finally, the article describes the pharmacological treatment of cardiac remodeling, which can be divided into three different stages of strategies: consolidated, promising and potential strategies
Effects of Continuous Aerobic Exercise on Skeletal Muscle Atrophy Induced by Heart Failure
Heart failure is a common and severe disease that worsens morbidity, mortality, and quality of life. One of the clinical manifestations of heart failure is peripheral muscular atrophy, whose presence impacts the prognosis of heart failure patients. Inflammation is one of the main mechanisms related to muscle atrophy. We hypothesized that inflammation, through excessive activation of the Nlrp3 inflammasome, would be tightly associated with skeletal muscle atrophy induced by heart failure. Additionally, aerobic exercise, well known for its anti-inflammatory action, would counteract this condition in a rat model of heart failure. PURPOSE: We aimed to evaluate the effects of continuous aerobic exercise training on gene expression of Nlrp3 and atrogin-1, a key gene involved in skeletal muscle atrophy, in rats with heart failure induced by monocrotaline. METHODS: Thirty male Wistar rats were randomly divided into four groups: Control (C), Exercised (Ex), Heart Failure (HF) and HF exercised (HFEx). Initially, rats in groups HF and HFEx received a single dose of monocrotaline 60 mg/kg, intraperitonially, while groups C and Ex received a saline solution injection of equivalent volume. Two days after the injection, rats in Ex and HFEx groups were submitted to 30 minutes of treadmill running, 5 days/week, for 4 weeks, at moderate-intensity, determined by maximal endurance test. Groups C and HF were not subjected to any exercise program. After 4 weeks, rats were euthanized and the medial head of the gastrocnemius muscle was collected. Gene expression of atrogin-1 and Nlrp3 was performed by real time PCR. Two-way ANOVA was used for statistical analysis with significance level of pRESULTS: The rats in HF group had lower gastrocnemius muscle mass than rats in the C group (C: 1.53 ±0.05; Ex: 1.37 ± 0.13; HF: 0.98 ± 0.21; HFEx:1.20 ± 0.19 g; pHFCONCLUSION: Our data showed that monocrotaline-induced heart failure caused skeletal muscle atrophy in rats, in a mechanism independent of the NLRP3 inflammasome. A 4-week continuous aerobic exercise protocol provided partial protection from skeletal muscle atrophy
Cardiac remodeling induced by smoking: concepts, relevance, and potential mechanisms
Cardiac or ventricular remodeling is characterized by molecular, cellular, and interstitial alterations that lead to changes in heart size, mass, geometry and function in response to a given insult. Currently, tobacco smoke exposure is recognized as one of these insults. Indeed, tobacco smoke exposure induces the enlargement of the left-sided cardiac chambers, myocardial hypertrophy, and ventricular dysfunction. Potential mechanisms for these alterations include hemodynamic and neurohormonal changes, oxidative stress, inflammation, nitric oxide bioavailability, matrix metalloproteinases and mitogen-activated protein kinase activation. This review will focus on the concepts, relevance, and potential mechanisms of cardiac remodeling induced by tobacco smoke
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