Superoxide dismutase in patients with chronic hepatitis C virus infection

It has been reported that hepatitis C virus (HCV) may cause oxidative stress in infected cells. Patients with chronic hepatitis C exhibit an increased production of tumor necrosis factor-alpha (TNF alpha), a cytokine that can produce oxidative stress by stimulating the generation of reactive oxygen species (ROS). Cell defense against ROS includes overexpression of Mn-superoxide dismutase (SOD), an inducible mitochondrial enzyme. To investigate cell defense against oxidative stress in HCV infection, we analyzed Mn-SOD mRNA in liver and in peripheral blood mononuclear cells (PBMC) from patients with chronic hepatitis C. Mn-SOD expression in PBMC was significantly increased in patients with HCV infection. Patients with sustained virological and biochemical response after therapy showed significantly lower Mn-SOD than patients with positive viremia. By contrast, Mn-SOD expression was not enhanced in the liver of patients with chronic hepatitis C. The values of Mn-SOD mRNA did not correlate with TNF alpha mRNA expression, viral load, or liver disease activity. Our results indicate that in HCV infection an induction of Mn-SOD was present in PBMC but absent in the liver, suggesting that this organ could be less protected against oxidative damage. Oxidative stress could participate in the pathogenesis of HCV infection

The A640G CYBA polymorphism associates with subclinical atherosclerosis in diabetes

Oxidative stress is implicated in diabetes. The NADPH oxidases are the main source of superoxide in phagocytic and vascular cells, and p22phox is a key subunit. Genetic variants of CYBA, the human p22phox gene, associate with cardiovascular disease. We investigated the association of the A640G polymorphism with diabetes and its impact on phagocytic NADPH oxidase-dependent superoxide production and subclinical atherosclerosis. We studied 1212 subjects in which clinical parameters including carotid intima-media thickness (cIMT) were assessed. The A640G polymorphism was genotyped by TaqMan probes. In 496 subjects, the NADPH oxidase-dependent superoxide production in peripheral blood mononuclear cells was assessed by chemiluminescence. The GG genotype prevalence was significantly higher in type 2 diabetic patients than in non-diabetic subjects. Peripheral blood mononuclear cells from diabetic GG patients presented higher NADPH oxidase-dependent superoxide production than those of diabetic AA/AG patients. Within the diabetic group, GG patients presented higher cIMT levels than AA/AG patients. The A640G CYBA polymorphism may be a marker of oxidative stress risk and may be indicative of subclinical atherosclerosis in type 2 diabetes

Taller Integrado I "Orgía Mecánica". Innovación Educativa

Un espacio pedagógico de convergencia para el aprendizaje y la práctica dialógica de la Aequitectura. Memoria de la experiencia realizada en la Escuela Técnica Superior de Arquitectura de Madrid en Noviembre de 200

Post-mortem findings in Spanish patients with COVID-19; a special focus on superinfections

IntroductionWhole-body autopsies may be crucial to understand coronavirus disease 2019 (COVID-19) pathophysiology. We aimed to analyze pathological findings in a large series of full-body autopsies, with a special focus on superinfections. MethodsThis was a prospective multicenter study that included 70 COVID-19 autopsies performed between April 2020 and February 2021. Epidemiological, clinical and pathological information was collected using a standardized case report form. ResultsMedian (IQR) age was 70 (range 63.75-74.25) years and 76% of cases were males. Most patients (90%,) had at least one comorbidity prior to COVID-19 diagnosis, with vascular risk factors being the most frequent. Infectious complications were developed by 65.71% of the patients during their follow-up. Mechanical ventilation was required in most patients (75.71%) and was mainly invasive. In multivariate analyses, length of hospital stay and invasive mechanical ventilation were significantly associated with infections (p = 0.036 and p = 0.013, respectively). Necropsy findings revealed diffuse alveolar damage in the lungs, left ventricular hypertrophy in the heart, liver steatosis and pre-infection arteriosclerosis in the heart and kidneys. ConclusionOur study confirms the main necropsy histopathological findings attributed to COVID-19 in a large patient series, while underlining the importance of both comorbid conditions and superinfections in the pathology

Clinical course of patients with severe COVID-19 pneumonia treated with remdesivir: A real-life study.

BackgroundThere is currently much uncertainty regarding the most optimal treatment for COVID-19. This study analyze the change in the clinical condition of patients hospitalized for severe COVID-19 pneumonia and treated with remdesivir in a real-life setting, based on the WHO Ordinal Scale. Clinical complications, treatment safety, and impact of other associated drugs were also analyzed.MethodsWe conducted an observational, retrospective study including patients treated with remdesivir. The need for admission to the ICU, the length of ICU and hospital stay, and the need for ventilatory support were analyzed. The laboratory parameters, drugs administered concomitantly, and difference in the length of hospital stay according to the concomitant treatment received were also evaluated. A univariate and multivariate Cox regression analysis was performed to analyze associated factors.ResultsA total of 92 patients were included. The mean length of hospital stay was 15 days, and 90% of the patients had been discharged from the hospital 28 days after starting treatment with remdesivir. The likelihood of hospital discharge among patients not presenting with hypertension as a comorbidity was significantly higher than that of those with this condition (HR = 3.19, P = 0.008). Nineteen patients had to be admitted to the ICU (mean of 18 days). Approximately 11% required invasive mechanical ventilation (mean of 22 days). Almost 37% of the patients received high-flow oxygen therapy and 14% non-invasive mechanical ventilation. Four deaths were recorded within the first week. Main adverse events were increases in transaminase and creatinine levels. Nosocomial infections were more frequent when remdesivir was combined with immunosuppressive drugs.ConclusionsPatients with severe COVID-19 pneumonia and treated with remdesivir require relatively prolonged hospital stays, many with a need for ventilatory support and, in a considerable proportion of cases, admission to the ICU. However, the observed survival rate is high, and the drug is well tolerated

Novel Polyphenol Oxidase Mined from a Metagenome Expression Library of Bovine Rumen

RL5, a gene coding for a novel polyphenol oxidase, was identified through activity screening of a metagenome expression library from bovine rumen microflora. Characterization of the recombinant protein produced in Escherichia coli revealed a multipotent capacity to oxidize a wide range of substrates (syringaldazine > 2,6-dimethoxyphenol > veratryl alcohol > guaiacol > tetramethylbenzidine > 4-methoxybenzyl alcohol > 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) >> phenol red) over an unusually broad range of pH from 3.5 to 9.0. Apparent Km and kcat values for ABTS, syringaldazine, and 2,6-dimetoxyphenol obtained from steady-state kinetic measurements performed at 40 °C, pH 4.5, yielded values of 26, 0.43, and 0.45 μm and 18, 660, and 1175 s-1, respectively. The Km values for syringaldazine and 2,6-dimetoxyphenol are up to 5 times lower, and the kcat values up to 40 times higher, than values previously reported for this class of enzyme. RL5 is a 4-copper oxidase with oxidation potential values of 745, 400, and 500 mV versus normal hydrogen electrode for the T1, T2, and T3 copper sites. A three-dimensional model of RL5 and site-directed mutants were generated to identify the copper ligands. Bioinformatic analysis of the gene sequence and the sequences and contexts of neighboring genes suggested a tentative phylogenetic assignment to the genus Bacteroides. Kinetic, electrochemical, and EPR analyses provide unequivocal evidence that the hypothetical proteins from Bacteroides thetaiotaomicron and from E. coli, which are closely related to the deduced protein encoded by the RL5 gene, are also multicopper proteins with polyphenol oxidase activity. The present study shows that these three newly characterized enzymes form a new family of functional multicopper oxidases with laccase activity related to conserved hypothetical proteins harboring the domain of unknown function DUF152 and suggests that some other of these proteins may also be laccases.This work was supported by grants from ViaLactiaBiosciences Ltd. (New Zealand), the BMBF BiotechGenoMik Programme (to P. N. G. and O. V. G.), European Community Project MERG-CT-2004-505242 “BIOMELI,” Spanish Ministry of Education and Science (VEM2004-08559) and Comunidad de Madrid Project (GR/AMB/0690/2004), Gobierno Vasco (to M. Z.), a European Community Marie Curie fellowship, a Spanish Ministerio de Ciencia y Tecnología-Ramón y Cajal contract (to M. F.), and Madrid Autonomic Community and European Social Funds (to M. P.).Peer reviewe

The A640G CYBA polymorphism associates with subclinical atherosclerosis in diabetes

Oxidative stress is implicated in diabetes. The NADPH oxidases are the main source of superoxide in phagocytic and vascular cells, and p22phox is a key subunit. Genetic variants of CYBA, the human p22phox gene, associate with cardiovascular disease. We investigated the association of the A640G polymorphism with diabetes and its impact on phagocytic NADPH oxidase-dependent superoxide production and subclinical atherosclerosis. We studied 1212 subjects in which clinical parameters including carotid intima-media thickness (cIMT) were assessed. The A640G polymorphism was genotyped by TaqMan probes. In 496 subjects, the NADPH oxidase-dependent superoxide production in peripheral blood mononuclear cells was assessed by chemiluminescence. The GG genotype prevalence was significantly higher in type 2 diabetic patients than in non-diabetic subjects. Peripheral blood mononuclear cells from diabetic GG patients presented higher NADPH oxidase-dependent superoxide production than those of diabetic AA/AG patients. Within the diabetic group, GG patients presented higher cIMT levels than AA/AG patients. The A640G CYBA polymorphism may be a marker of oxidative stress risk and may be indicative of subclinical atherosclerosis in type 2 diabetes