Search results for "peroxidase"
showing 10 items of 435 documents
Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus.
2009
Codoner-Franch P, Pons-Morales S, Boix-Garcia L, Valls-Belles V. Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus. Background: Type 1 diabetes (T1D) mellitus and obesity are recognized risk factors for cardiovascular disease (CVD). A common mechanism underlying an increased risk for endothelial dysfunction in these two metabolic diseases is oxidative stress. Objective: To evaluate and compare the oxidant/antioxidant defense systems in children affected with T1D or obesity in order to determine the importance of oxidative stress before the emergence of complications. Subjects: Children with T1D (n = 20) or obesity (n = 22), without com…
Differences in the behavior of advanced glycation end products and advanced oxidation protein products in patients with allergic rhinitis
2013
BACKGROUND: The presence of oxidative stress in patients with asthma is well documented; however, the role of oxidative stress in allergic rhinitis has received less attention, although it is likely to be similar to that observed in patients with asthma. Advanced glycation end products (AGEs) and advanced oxidation protein products (AOPPs) are compounds formed by the transformation of macromolecules, including proteins, which can serve as densitometric markers of oxidative stress and inflammation in several diseases. OBJECTIVE: The aim of this study was to investigate the role of AGEs and AOPPs as new markers of oxidative stress and inflammation in patients affected by allergic rhinitis. ME…
Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair
2015
Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed …
Immunoperoxidase Staining of Fine-Needle Aspiration Biopsies of Renal Cell Carcinoma Using Tumor-Specific Monoclonal Antibody
1987
In 30 nephrectomy specimens, fine needle aspiration biopsies (FNAB) were performed both in the tumor and in the macroscopically normal part of the kidney: 18 were well differentiated renal cell carcinoma (RCC), 6 were moderately differentiated RCC, 4 were poorly differentiated RCC, and 2 were oncocytomas. FNAB was also performed in a bone metastasis of RCC. FNAB materials were stained using the immunoperoxidase method with RCC-specific monoclonal antibody and were compared with the staining of frozen sections. In all cases where tumor-antigen expression could be demonstrated in the frozen sections, a FNAB had already proven positive. There were only 2 false-negative cases where sufficient c…
Effect of Ti(IY) on some indicators of physiological activity inCapsicum annuum, L.
1994
SummaryPaprika pepper (Capsicum annuum, L., cv. Negral) plants grown in a greenhouse were supplied Ti(IV) ascorbate through the roots or through leaves. Biomass production, peroxidase (donor: H2O, oxidoreductase; EC 1.11.1.7) activity, and malic acid, starch and chlorophyll concentrations were determined in different plant organs. It was observed that Ti increased the concentration of some of the metabolites studied and promoted both peroxidase activity and biomass production. The profitable effect of the Ti treatments could occur because they enhance the availability of other nutrients. This effect could be due to the low redox potential of the Ti+3/Ti+4 system that catalyzes the activity …
Interference of carbidopa and other catechols with reactions catalyzed by peroxidases
2018
Abstract Background A number of compounds, including ascorbic acid, catecholamines, flavonoids, p-diphenols and hydrazine derivatives have been reported to interfere with peroxidase-based medical diagnostic tests (Trinder reaction) but the mechanisms of these effects have not been fully elucidated. Methods Reactions of bovine myeloperoxidase with o-dianisidine, bovine lactoperoxidase with ABTS and horseradish peroxidase with 4-aminoantipyrine/phenol in the presence of carbidopa, an anti-Parkinsonian drug, and other catechols, including l -dopa, were monitored spectrophotometrically and by measuring hydrogen peroxide consumption. Results Chromophore formation in all three enzyme/substrate sy…
Fructose-enriched diet modifies antioxidant status and lipid metabolism in spontaneously hypertensive rats
2005
Abstract Objective High-fructose consumption in industrial countries has been shown to induce metabolic abnormalities or syndrome X. Changes in antioxidant defense are unknown in hypertension associated with metabolic disorders induced by high-fructose feeding. Methods Twenty spontaneously hypertensive rats were assigned to one of two groups; one received a fructose-enriched diet (60% fructose) and the other a starch diet. After a 13-wk diet period, total antioxidant status was assessed in the blood and liver by monitoring the rate of free radical-induced red blood cell hemolysis. Antioxidants (enzymes and vitamins) were determined in blood and liver. Gene expression of antioxidant enzymes …
Hole burning and pressure phenomena in chromoproteins
1993
Abstract We investigated the behavior of spectral holes under pressure at various frequencies within the inhomogeneous band for two proteins, namely myoglobin and horseradish peroxidase. In order to achieve narrow bandwidth hole burning, the heme chromophore was replaced by protoporphyrin IX and mesoporphyrin IX, respectively. In myoglobin, we found that the pressure induced shift of the holes varied in a strongly non-linear fashion, when the burn-frequency was tuned across the absorption band. In horseradish peroxidase the pressure shift was linear with burn-frequency but changed in a dramatic fashion upon complex formation with a substrate molecule. These observations are interpreted with…
Elucidation of Carbohydrate Molecular Interaction Mechanism of Recombinant and Native ArtinM
2013
[EN] The quartz crystal microbalance (QCM) technique has been applied for monitoring the biorecognition of ArtinM lectins at low horseradish peroxidase glycoprotein (HRP) concentrations, using a simple kinetic model based on Langmuir isotherm in previous work.(18) The latter approach was consistent with the data at dilute conditions but it fails to explain the small differences existing in the jArtinM and rArtinM due to ligand binding concentration limit. Here we extend this analysis to differentiate sugar-binding event of recombinant (rArtinM) and native (jArtinM) ArtinM lectins beyond dilute conditions. Equivalently, functionalized quartz crystal microbalance with dissipation monitoring (…
Functional Enzyme Mimics for Oxidative Halogenation Reactions that Combat Biofilm Formation
2017
Transition-metal oxide nanoparticles and molecular coordination compounds are highlighted as functional mimics of halogenating enzymes. These enzymes are involved in halometabolite biosynthesis. Their activity is based upon the formation of hypohalous acids from halides and hydrogen peroxide or oxygen, which form bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities in follow-up reactions. Therefore, enzyme mimics and halogenating enzymes may be valuable tools to combat biofilm formation. Here, halogenating enzyme models are briefly described, enzyme mimics are classified according to their catalytic functions, and current knowledge about th…