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56 result(s) for "de Oliveira, Jarbas Rodrigues"
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Sepsis-Associated Encephalopathy: from Pathophysiology to Progress in Experimental Studies
Sepsis is an organ dysfunction caused by an uncontrolled inflammatory response from the host to an infection. Sepsis is the main cause of morbidity and mortality in intensive care units (ICU) worldwide. One of the first organs to suffer from injuries resulting from sepsis is the brain. The central nervous system (CNS) is particularly vulnerable to damage, mediated by inflammatory and oxidative processes, which can cause the sepsis-associated encephalopathy (SAE), being reported in up to 70% of septic patients. This review aims to bring a summary of the main pathophysiological changes and dysfunctions in SAE, and the main focuses of current experimental studies for new treatments and therapies. The pathophysiology of SAE is complex and multifactorial, combining intertwined processes, and is promoted by countless alterations and dysfunctions resulting from sepsis, such as inflammation, neuroinflammation, oxidative stress, reduced brain metabolism, and injuries to the integrity of the blood-brain barrier (BBB). The treatment is limited once its cause is not completely understood. The patient’s sedation is far to provide an adequate treatment to this complex condition. Studies and experimental advances are important for a better understanding of its pathophysiology and for the development of new treatments, medicines, and therapies for the treatment of SAE and to reduce its effects during and after sepsis.
Liraglutide improves liver microvascular dysfunction in cirrhosis: Evidence from translational studies
Hepatic stellate cells (HSC) play a key role in the development of chronic liver disease (CLD). Liraglutide, well-established in type 2 diabetes, showed anti-inflammatory and anti-oxidant properties. We evaluated the effects of liraglutide on HSC phenotype and hepatic microvascular function using diverse pre-clinical models of CLD. Human and rat HSC were in vitro treated with liraglutide, or vehicle, and their phenotype, viability and proliferation were evaluated. In addition, liraglutide or vehicle was administered to rats with CLD. Liver microvascular function, fibrosis, HSC phenotype and sinusoidal endothelial phenotype were determined. Additionally, the effects of liraglutide on HSC phenotype were analysed in human precision-cut liver slices. Liraglutide markedly improved HSC phenotype and diminished cell proliferation. Cirrhotic rats receiving liraglutide exhibited significantly improved liver microvascular function, as evidenced by lower portal pressure, improved intrahepatic vascular resistance, and marked ameliorations in fibrosis, HSC phenotype and endothelial function. The anti-fibrotic effects of liraglutide were confirmed in human liver tissue and, although requiring further investigation, its underlying molecular mechanisms suggested a GLP1-R-independent and NF-κB-Sox9-dependent one. This study demonstrates for the first time that liraglutide improves the liver sinusoidal milieu in pre-clinical models of cirrhosis, encouraging its clinical evaluation in the treatment of chronic liver disease.
Maternal separation induces long-term oxidative stress alterations and increases anxiety-like behavior of male Balb/cJ mice
Early life stress (ELS) exposure is a well-known risk factor for the development of psychiatric conditions, including anxiety disorder. Preclinical studies show that maternal separation (MS), a classical model of ELS, causes hypothalamic–pituitary–adrenal (HPA) axis alterations, a key contributor to the stress response modulation. Given that HPA axis activation has been shown to induce oxidative stress, it is possible to hypothesize that oxidative stress mediates the relationship between chronic ELS exposure and the development of several disorders. Here, we investigate the effects of MS in the oxidative status [plasma and brain reduced glutathione, catalase and thiobarbituric acid reactive substances (TBARS)], metabolism (glucose, triglycerides and cholesterol) and anxiety-like behaviors in adult Balb/cJ mice. In short, we found that MS increased anxiety-like behaviors in the open field, light/dark test but not in the elevated-plus maze. Animals also presented increased circulating cholesterol, increased TBARS in the plasma and decreased catalase in the hippocampus. Our findings suggest that MS induces long-term alterations in oxidative stress and increased anxiety-like behaviors.
Contribution of S6K1/MAPK Signaling Pathways in the Response to Oxidative Stress: Activation of RSK and MSK by Hydrogen Peroxide
Cells respond to different kind of stress through the coordinated activation of signaling pathways such as MAPK or p53. To find which molecular mechanisms are involved, we need to understand their cell adaptation. The ribosomal protein, S6 kinase 1 (S6K1), is a common downstream target of signaling by hormonal or nutritional stress. Here, we investigated the initial contribution of S6K1/MAPK signaling pathways in the cell response to oxidative stress produced by hydrogen peroxide (H2O2). To analyze S6K1 activation, we used the commercial anti-phospho-Thr389-S6K1 antibody most frequently mentioned in the bibliography. We found that this antibody detected an 80-90 kDa protein that was rapidly phosphorylated in response to H2O2 in several human cells. Unexpectedly, this phosphorylation was insensitive to both mTOR and PI3K inhibitors, and knock-down experiments showed that this protein was not S6K1. RSK and MSK proteins were candidate targets of this phosphorylation. We demonstrated that H2O2 stimulated phosphorylation of RSK and MSK kinases at residues that are homologous to Thr389 in S6K1. This phosphorylation required the activity of either p38 or ERK MAP kinases. Kinase assays showed activation of RSK and MSK by H2O2. Experiments with mouse embryonic fibroblasts from p38 animals' knockout confirmed these observations. Altogether, these findings show that the S6K1 signaling pathway is not activated under these conditions, clarify previous observations probably misinterpreted by non-specific detection of proteins RSK and MSK by the anti-phospho-Thr389-S6K1 antibody, and demonstrate the specific activation of MAPK signaling pathways through ERK/p38/RSK/MSK by H2O2.
Sex differences in outcomes of patients undergoing on-pump coronary artery bypass grafting surgery
There are controversies regarding the impact of sex on mortality and postoperative complications in patients undergoing on-pump coronary artery bypass grafting (CABG), although some studies demonstrate comparable outcomes. This study sought to evaluate sex differences regarding risk factors associated with hospital mortality and postoperative clinical outcomes among patients undergoing isolated on-pump CABG. We conducted a retrospective observational cohort study of patients who underwent isolated on-pump CABG from January 1996 to January 2020. Patients were divided into two groups (male and female) and compared regarding preoperative characteristics, surgical technical variables, and in-hospital outcomes. All-cause mortality between groups was compared using logistic regression. Risk factors for mortality, along with their respective odds ratios (OR), were separately assessed using a logistic regression model with p-values for interaction. We analyzed 4,882 patients, of whom 31.6% were female. Women exhibited a higher prevalence of age >75 years (12.2% vs 8.3%, p<0.001), obesity (22.6% vs 11.5%, p<0.001), diabetes (41.6% vs 32.2%, p<0.001), hypertension (85.2% vs 73.5%, p<0.001), and NYHA functional classes 3 and 4 (16.2% vs 11.2%, p<0.001) compared to men. Use of the mammary artery for revascularization was less frequent among women (73.8% vs 79.9%, p<0.001), who also received fewer saphenous vein grafts (2.17 vs 2.27, p = 0.002). A history of previous or recent myocardial infarction (MI) had an impact on women’s mortality, unlike in men (OR 1.61 vs 0.94, p = 0.014; OR 1.86 vs 0.99, p = 0.015, respectively). After adjusting for several risk factors, mortality was found to be comparable between men and women, with an OR of 1.20 (95% CI 0.94–1.53, p = 0.129). In conclusion, female patients undergoing isolated on-pump CABG presented with a higher number of comorbidities. Previous and recent MI were associated with higher mortality only in women. In this cohort analysis, female gender was not identified as an independent risk factor for outcome after CABG.
Mesenchymal stem cells decrease lung inflammation during sepsis, acting through inhibition of the MAPK pathway
Background Sepsis is a severe medical condition that ranks among the top 10 causes of death worldwide and which has permanently high incidence rates. Mesenchymal stem cells (MSCs) have been found to be potent modulators of immune responses. More importantly, there is evidence that MSCs have a beneficial effect on preclinical models of polymicrobial sepsis. However, the changes caused by the MSCs in the effector cells of the host immune system remain unclear. Methods A mouse model of sepsis (male C57BL/6 mice) with three experimental groups was used for experiments in vivo: a control group, an untreated septic group, and a septic group treated with MSCs. In vitro experiments were performed using a cell line of pulmonary macrophages (RAW 264.7) co-cultured with MSCs and stimulated with lipopolysaccharide (LPS). Results In vivo we demonstrated that treatment with MSCs was able to reduce the expression of cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB), and thereby decrease the production of inflammatory cytokines. In vitro experiments using a co-culture of macrophages with MSCs showed a decrease in COX-2 and NF-κB, and showed that this reduction was directly related to the ability of MSCs to inhibit phosphorylation of ERK, RSK, and p38, enzymes that belong to the family of mitogen-activated protein kinases (MAPKs). Conclusions This study demonstrated that MSCs are able to inhibit the MAPK pathway activation, modulating the inflammatory response during sepsis. This understanding that MSCs can remodel the response of host cells and improve the course of sepsis is essential for developing new treatments for this pathology.
Phase angle of bioimpedance as a marker of inflammation in cardiovascular diseases: A systematic review
•Phase angle is inversely associated with inflammatory markers in cardiovascular diseases.•Increased levels of C-reactive protein and tumor necrosis factor-α are associated with a smaller phase angle.•The phase angle is a potential tool for identifying the inflammatory state in individuals with cardiovascular diseases. [Display omitted] The aim of this systematic review was to investigate whether phase angle (PhA) of bioelectrical impedance is associated with inflammatory markers in cardiovascular diseases (CVDs). A search was performed in the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Latin American Caribbean Health Sciences Literature (LILACS), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Scopus; and in the gray literature up to January 2022. Studies with individuals with CVDs were included, to evaluate the association between PhA and the inflammatory markers interleukin (IL)-6, IL-10, IL-18, IL-1β, IL-33, tumor necrosis factor (TNF)-α, C-reactive protein (CRP), toll-like receptor (TLR) 2, TLR 4, nuclear factor κB, pathogen-associated molecular pattern molecules, lipopolysaccharides, interferon-γ–inducing factor, and JAK STAT. We identified 755 articles and, after an eligibility analysis, 5 studies were included. The inflammatory markers investigated in the studies were CRP, TNF-α, and IL-33. In patients with CVDs, PhA was negatively associated with CRP and TNF-α in 80% and 100% of the studies, respectively. The present results suggested that PhA is inversely associated with inflammatory markers in individuals with CVDs, and its clinical use is encouraged for better therapeutic planning.
Exenatide induces autophagy and prevents the cell regrowth in HepG2 cells
The incidence of hepatocellular carcinoma (HCC) keeps rising year by year, and became the second leading cause of cancer-related death. Some studies have found that liraglutide, a GLP-1 analog, may decrease the tumor cells proliferation. Due to this, the aim of this work is to investigate the antiproliferative potential of exenatide, another GLP-1 analog. Cell proliferation was assessed by direct count with Trypan blue dye exclusion. Flow cytometry was used to determinate autophagy and nuclear staining. Morphometric analysis was used to verify senescence and apoptosis. The mechanism that induced cell growth inhibition was analyzed by Western Blot. Treatment with exenatide significantly decreases cell proliferation and increases autophagy, both in relation to control and liraglutide. In addition, mTOR inhibition was greater in cells treated with exenatide. In relation to chronic treatment, exenatide does not allow cellular regrowth by preventing some resistance mechanism that the cells can acquire. These results suggest that exenatide has a potent anti-proliferative activity via mTOR modulation and, among the GLP-1 analogs tested, could be in the future an alternative for HCC treatment.
Octyl gallate induces hepatic steatosis in HepG2 cells through the regulation of SREBP-1c and PPAR-gamma gene expression
Octyl gallate (OG) is an antioxidant commonly used in food, although there is no definition of its acceptable daily intake. There are reports and showing that food additives and drugs can alter lipid metabolism. Lipid droplet accumulation in hepatic cells is one of the main findings in the unregulated lipid metabolism and is strongly related to the development of nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the effects of OG on lipid metabolism in the hepatocellular carcinoma cell line (HepG2). The results have shown, for the first time, that treatment with OG increased the overall amount of lipids, the triglyceride concentration, the lipid droplet area, and SREBP-1c and PPAR-γ gene expression. Taken together, the findings indicate that OG induces lipid droplet accumulation in HepG2 cells through the regulation of SREBP-1c and PPAR-γ gene expression without involving mTOR/S6K1 and may contribute to NAFLD when used as a food additive.
Fructose-1,6-bisphosphate prevents pulmonary fibrosis by regulating extracellular matrix deposition and inducing phenotype reversal of lung myofibroblasts
Pulmonary fibrosis (PF) is the result of chronic injury where fibroblasts become activated and secrete large amounts of extracellular matrix (ECM), leading to impaired fibroblasts degradation followed by stiffness and loss of lung function. Fructose-1,6-bisphosphate (FBP), an intermediate of glycolytic pathway, decreases PF development, but the underlying mechanism is unknown. To address this issue, PF was induced in vivo using a mouse model, and pulmonary fibroblasts were isolated from healthy and fibrotic animals. In PF model mice, lung function was improved by FBP as revealed by reduced collagen deposition and downregulation of ECM gene expression such as collagens and fibronectin. Fibrotic lung fibroblasts (FLF) treated with FBP for 3 days in vitro showed decreased proliferation, contraction, and migration, which are characteristic of myofibroblast to fibroblast phenotype reversal. ECM-related genes and proteins such as collagens, fibronectin and α-smooth muscle actin, were also downregulated in FBP-treated FLF. Moreover, matrix metalloproteinase (MMP) 1, responsible for ECM degradation, was produced only in fibroblasts obtained from healthy lungs (HLF) and FBP did not alter its expression. On the other hand, tissue inhibitor of metalloproteinase (TIMP)-1, a MMP1 inhibitor, and MMP2, related to fibroblast tissue-invasion, were predominantly produced by FLF and FBP was able to downregulate its expression. These results demonstrate that FBP may prevent bleomycin-induced PF development through reduced expression of collagen and other ECM components mediated by a reduced TIMP-1 and MMP2 expression.