scholarly journals Bactericidal activity of a superoxide anion-generating system. A model for the polymorphonuclear leukocyte.

1979 ◽  
Vol 149 (1) ◽  
pp. 27-39 ◽  
Author(s):  
H Rosen ◽  
S J Klebanoff
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Bactericidal Activity ◽  
Parent Strain ◽  
Carotenoid Pigments ◽  
Bacterial Killing ◽  
Oxidase System ◽  
System A ◽  
Presence And Absence ◽  
Generating System

The acetaldehyde-xanthine oxidase system in the presence and absence of myeloperoxidase (MPO) and chloride has been employed as a model of the oxygen-dependent antimicrobial systems of the PMN. The unsupplemented xanthine oxidase system was bactericidal at relatively high acetaldehyde concentrations. The bactericidal activity was inhibited by superoxide dismutase (SOD), catalase, the hydroxyl radical (OH.) scavengers, mannitol and benzoate, the singlet oxygen (1O2) quenchers, azide, histidine, and 1,4-diazabicyclo[2,2,2]octane (DABCO) and by the purines, xanthine, hypoxanthine, and uric acid. The latter effect may account for the relatively weak bactericidal activity of the xanthine oxidase system when purines are employed as substrate. A white, carotenoid-negative mutant strain of Sarcina lutea was more susceptible to the acetaldehyde-xanthine oxidase system than was the yellow, carotenoid-positive parent strain. Carotenoid pigments are potent 1O2 quenchers. The xanthine oxidase system catalyzes the conversion of 2,5-diphenylfuran to cis-dibenzoylethylene, a reaction which can occur by a 1O2 mechanism. This conversion is inhibited by SOD, catalase, azide, histidine, DABCO, xanthine, hypoxanthine, and uric acid but is only slightly inhibited by mannitol and benzoate. The addition of MPO and chloride to the acetaldehyde-xanthine oxidase system greatly increases bactericidal activity; the minimal effective acetaldehyde concentration is decreased 100-fold and the rate and extent of bacterial killing is increased. The bactericidal activity of the MPO-supplemented system is inhibited by catalase, benzoate, azide, DABCO, and histidine but not by SOD or mannitol. Thus, the acetaldehyde-xanthine oxidase system which like phagocytosing PMNs generates superoxide (O.2-) and hydrogen peroxide, is bactericidal both in the presence and absence of MPO and chloride. The MPO-supplemented system is considerably more potent; however, when MPO is absent, bactericidal activity is observed which may be mediated by the interaction of H2O2 and O.2- to form OH. and 1O2.

scholarly journals Hemolysis and iodination of erythrocyte components by a myeloperoxidase- mediated system

Blood ◽  
1975 ◽  
Vol 45 (5) ◽  
pp. 699-707 ◽  
Author(s):  
SJ Klebanoff ◽  
RA Clark
Keyword(s):  
Superoxide Dismutase ◽  
Thyroid Hormones ◽  
Glucose Oxidase ◽  
Xanthine Oxidase ◽  
Combined Effect ◽  
Oxidase System ◽  
Generating System

Abstract Erythrocytes are hemolyzed by myeloperoxidase, an H2O2-generating system (glucose + glucose oxidase; hypoxanthine + xanthine oxidase) and an oxidizable cofactor (chloride, iodide, thyroxine, triiodothyronine). The combined effect of chloride and either iodide or the thyroid hormones is greater than additive. Myeloperoxidase can be replaced by lactoperoxidase in the iodide-, thyroxine and triiodothyronine- dependent, but not in the chloride-dependent, systems. Hemolysis is is inhibited by the peroxidase inhibitors, azide and cyanide, and by catalase and is stimulated by superoxide dismutase when the xanthine oxidase system is employed as the source of H2O2. Hemolysis by the iodide-dependent system is associated with the iodination of erythrocyte components.

scholarly journals Note on an accelerating action of uric acid on the xanthine oxidase system

1932 ◽  
Vol 26 (2) ◽  
pp. 472-475 ◽  
Author(s):  
Douglas Creese Harrison
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Oxidase System

scholarly journals The effect of oxygen-dependent antimicrobial systems on strains ofLegionella pneumophilaof different virulence

1986 ◽  
Vol 97 (1) ◽  
pp. 61-69 ◽  
Author(s):  
R. I. Jepras ◽  
R. B. Fitzgeorge
Keyword(s):  
Xanthine Oxidase ◽  
Bactericidal Activity ◽  
Legionella Pneumophila ◽  
Fine Particle ◽  
Polymorphonuclear Neutrophil ◽  
Oxidase System ◽  
Virulent Strains ◽  
Halide System ◽  
Bactericidal Activities ◽  
Effect Of Oxygen

SUMMARYFour strains ofLegionella pneumophilaof different virulence as identified by ability to produce pneumonia and death in guinea-pigs infected by a fine-particle aerosol were examined for factors which may intracellularly influence virulence. Possible bactericidal mechanisms possessed by alveolar phagocytes were examined. A relationship could be established between resistance to H2O2, catalase activity and virulence amongst the strains.Virulent strains resisted the bactericidal activity generated by the xanthine oxidase system; avirulent strains did not. Incorporation of various specific inhibitors of the xanthine oxidase system indicated that the main bactericidal activities were associated with the production of H2O2and hydroxyl radicals ('OH).All strains ofL. pneumophilawere susceptible to the bactericidal activity generated by the myeloperoxidase-H202-halide system, confirming earlier observations that polymorphonuclear neutrophil leucocytes (PMNLS) are able to kill both virulent and avirulent strains ofL. pneumophila.

scholarly journals Hemolysis and iodination of erythrocyte components by a myeloperoxidase- mediated system

Blood ◽  
1975 ◽  
Vol 45 (5) ◽  
pp. 699-707
Author(s):  
SJ Klebanoff ◽  
RA Clark
Keyword(s):  
Superoxide Dismutase ◽  
Thyroid Hormones ◽  
Glucose Oxidase ◽  
Xanthine Oxidase ◽  
Combined Effect ◽  
Oxidase System ◽  
Generating System

Erythrocytes are hemolyzed by myeloperoxidase, an H2O2-generating system (glucose + glucose oxidase; hypoxanthine + xanthine oxidase) and an oxidizable cofactor (chloride, iodide, thyroxine, triiodothyronine). The combined effect of chloride and either iodide or the thyroid hormones is greater than additive. Myeloperoxidase can be replaced by lactoperoxidase in the iodide-, thyroxine and triiodothyronine- dependent, but not in the chloride-dependent, systems. Hemolysis is is inhibited by the peroxidase inhibitors, azide and cyanide, and by catalase and is stimulated by superoxide dismutase when the xanthine oxidase system is employed as the source of H2O2. Hemolysis by the iodide-dependent system is associated with the iodination of erythrocyte components.

Renal purine efflux and xanthine oxidase activity during experimental nephrosis in rats: Difference between puromycin aminonucleoside and adriamycin nephrosis

1990 ◽  
Vol 78 (3) ◽  
pp. 283-293 ◽  
Author(s):  
Fabrizio Ginevri ◽  
Rosanna Gusmano ◽  
Roberta Oleggini ◽  
Silvia Acerbo ◽  
Roberta Bertelli ◽  
...  
Keyword(s):  
Uric Acid ◽  
Free Radicals ◽  
Urinary Excretion ◽  
Xanthine Oxidase ◽  
Oxidase Activity ◽  
Xanthine Dehydrogenase ◽  
Renal Tissue ◽  
Puromycin Aminonucleoside ◽  
Oxidase System ◽  
Baseline Values

1. The hypothesis was tested that the renal xanthine oxidase system provides a source of oxygen free radicals in puromycin aminonucleoside and adriamycin experimental nephrosis by generating uric acid from hypoxanthine and xanthine. 2. The concentrations in renal tissue of the putative intermediary products of puromycin aminonucleoside metabolism, hypoxanthine and xanthine, and of their precursors, adenosine and inosine, were lower in rats treated with puromycin aminonucleoside than in normal controls, whereas concentrations of the metabolites were normal after adriamycin intoxication. Their daily urinary excretion was lower in the 24 h after puromycin amino-nucleoside administration compared with the baseline values and returned to near normal levels within 5 days. After adriamycin the 24 h urinary excretion of xanthine and uric acid was double the baseline levels (P <0.001). 3. When equimolar amounts of hypoxanthine were injected instead of puromycin aminonucleoside, the concentration of all bases increased slightly in renal tissue and their urinary efflux was double the baseline level: allantoin, uric acid, the unmodified nucleotide and xanthine were the most represented compounds in urine. 4. The enzymatic activities relative to xanthine oxidase (EC 1.1.3.22) and xanthine dehydrogenase (EC 1.1.1.204) in renal tissues were unchanged 1 day after puromycin aminonucleoside or hypoxanthine intoxication and only moderately increased in both groups at 13 days (the time of appearance of heavy proteinuria in the puromycin aminonucleoside-treated group). In contrast, xanthine oxidase and xanthine dehydrogenase activities were higher in adriamycin-treated rats at 1 and 15 days after the treatment (P <0.001). 5. Feeding rats with normoprotein diets containing tungsten induced a marked and constant decrease of renal xanthine oxidase and xanthine dehydrogenase activities to 20% of the baseline values in both puromycin amino-nucleoside- and adriamycin-treated rats. Inhibition of renal xanthine oxidase and xanthine dehydrogenase activities by tungsten was associated with a marked reduction (P <0.001) of proteinuria in adriamycin-treated rats and the same occurred with allopurinol, a specific inhibitor of xanthine oxidase activity. In contrast, tungsten treatment did not reduce the proteinuria associated with puromycin aminonucleoside, which reached a maximum 13 days after puromycin aminonucleoside intoxication. Hypoxanthine-treated rats were normoproteinuric after 2 months of observation. 6. These data demonstrate an activation of renal xanthine oxidase and xanthine dehydrogenase after adriamycin intoxication which is relevant to the induction of proteinuria. They also argue against the involvement of the renal xanthine oxidase system as a source of free radicals in puromycin aminonucleoside nephrosis and suggest that the nucleotide cycle is not a normal route for puromycin aminonucleoside degradation. Other metabolic pathways for free radical generation from puromycin aminonucleoside must be considered.

Chain-breaking/Preventive Antioxidant, Urate-lowering, and Anti-inflammatory Effects of Pure Curcumin

2020 ◽  
Vol 17 (1) ◽  
pp. 66-74
Author(s):  
Seghira Bisset ◽  
Widad Sobhi ◽  
Chawki Bensouici ◽  
Abdelhalim Khenchouche
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Acid Production ◽  
Biological Activities ◽  
Antioxidant Effect ◽  
Metal Chelating ◽  
Wide Range ◽  
Chain Breaking ◽  
Pharmaceutical Industries ◽  
Anti Inflammatory

Background: Several researches have shown that therapeutic compounds or phytochemicals from natural sources are important in the food as it is valuable in pharmaceutical industries due to their fewer side effects and potent against various diseases. Curcumin, a major polyphenol derived from turmeric spice, which used in many foods, has a wide range of biological activities, with quite a safety. Objective: The goal of this study was to investigate the antioxidant, urate-lowering, and antiinflammatory effects of pure curcumin. Methods: The antioxidant activity was evaluated for chain-breaking antioxidant effect (radicalscavenging and reducing abilities assays) and for preventive antioxidant effect with metal chelating assay, the urate-lowering was assayed on aspectrophotometer by measuring the inhibition of uric acid production by xanthine oxidase (XO) enzyme, and the anti-inflammatory effect was estimated using in vitro albumin denaturation inhibition. Results: Curcumin showed a significant and good chain-breaking antioxidant effect, both in free radical- scavenging assays (Galvinoxyl radical, ABTS, and hydroxyl radical), and in reducing abilities methods (reducing power, Cupric ion reducing antioxidant capacity and O-phenanthroline assays). In preventive antioxidant effect, assessed with the metal chelating assay, curcumin showed significant effect but with high concentration compared with standard. In the xanthine/xanthine oxidase system, curcumin significantly inhibited uric acid production (IC50=0.71 ± 0.06 mg/mL). Regarding antiinflammatory activity, curcumin showed significant inhibition of albumin denaturation with an IC50 value of 1181.69 ± 1.11μg/mL. Conclusion: These results indicated that curcumin showed promising antioxidant, anti-gout and antiinflammatory properties and might be used as potential, natural drugs against oxidative and inflammation- related diseases.

Allopurinol and Loss of Consciousness in a 78-old Year Man Suffering from Gout

2020 ◽  
Vol 20 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Mahnaz Arian ◽  
Mina AkbariRad ◽  
Ahmad Bagheri Moghaddam ◽  
Abdollah Firoozi ◽  
Mohammad Jami
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Kidney Stones ◽  
Oxidase Inhibitor ◽  
Loss Of Consciousness ◽  
Drug Induced ◽  
Xanthine Oxidase Inhibitor ◽  
Case Presentation ◽  
Maculopapular Rashes ◽  
Reduced State

: Allopurinol is an FDA -Approved xanthine oxidase inhibitor, which is effective in the treatment of gout, hyperuricemia and uremic kidney stones in patients with an increased level of uric acid excretion. Xanthine oxidase acts by converting hypoxanthine and xanthine into uric acid, and therefore its inhibition results in decreased production of uric acid. The most common side effects of this medication are as follows: maculopapular rashes, hives, itching, headache, dizziness, abnormal hair loss, fever and hypersensitivity reaction. Case Presentation: This report represents a case of drug-induced meningitis of a senile man who ended up in the ICU due to the remarkably reduced state of consciousness.

scholarly journals Functional and Transcriptional Adaptations of Blood Monocytes Recruited to the Cystic Fibrosis Airway Microenvironment In Vitro

2021 ◽  
Vol 22 (5) ◽  
pp. 2530
Author(s):  
Bijean D. Ford ◽  
Diego Moncada Giraldo ◽  
Camilla Margaroli ◽  
Vincent D. Giacalone ◽  
Milton R. Brown ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Bactericidal Activity ◽  
Scavenger Receptor ◽  
Receptor Expression ◽  
Blood Monocytes ◽  
Bacterial Killing ◽  
Blood Neutrophils ◽  
Vitro Model

Cystic fibrosis (CF) lung disease is dominated by the recruitment of myeloid cells (neutrophils and monocytes) from the blood which fail to clear the lung of colonizing microbes. In prior in vitro studies, we showed that blood neutrophils migrated through the well-differentiated lung epithelium into the CF airway fluid supernatant (ASN) mimic the dysfunction of CF airway neutrophils in vivo, including decreased bactericidal activity despite an increased metabolism. Here, we hypothesized that, in a similar manner to neutrophils, blood monocytes undergo significant adaptations upon recruitment to CFASN. To test this hypothesis, primary human blood monocytes were transmigrated in our in vitro model into the ASN from healthy control (HC) or CF subjects to mimic in vivo recruitment to normal or CF airways, respectively. Surface phenotype, metabolic and bacterial killing activities, and transcriptomic profile by RNA sequencing were quantified post-transmigration. Unlike neutrophils, monocytes were not metabolically activated, nor did they show broad differences in activation and scavenger receptor expression upon recruitment to the CFASN compared to HCASN. However, monocytes recruited to CFASN showed decreased bactericidal activity. RNASeq analysis showed strong effects of transmigration on monocyte RNA profile, with differences between CFASN and HCASN conditions, notably in immune signaling, including lower expression in the former of the antimicrobial factor ISG15, defensin-like chemokine CXCL11, and nitric oxide-producing enzyme NOS3. While monocytes undergo qualitatively different adaptations from those seen in neutrophils upon recruitment to the CF airway microenvironment, their bactericidal activity is also dysregulated, which could explain why they also fail to protect CF airways from infection.

scholarly journals Detecting and Quantifying Polyhaloaromatic Environmental Pollutants by Chemiluminescence-Based Analytical Method

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3365
Author(s):  
Ben-Zhan Zhu ◽  
Miao Tang ◽  
Chun-Hua Huang ◽  
Li Mao
Keyword(s):  
Analytical Method ◽  
Degradation Kinetics ◽  
Environmental Pollutants ◽  
Environmental Implications ◽  
Future Studies ◽  
System A ◽  
Quinoid Structure ◽  
Fenton System ◽  
Generating System ◽  
H2o2 System

Polyhaloaromatic compounds (XAr) are ubiquitous and recalcitrant in the environment. They are potentially carcinogenic to organisms and may induce serious risks to the ecosystem, raising increasing public concern. Therefore, it is important to detect and quantify these ubiquitous XAr in the environment, and to monitor their degradation kinetics during the treatment of these recalcitrant pollutants. We have previously found that unprecedented intrinsic chemiluminescence (CL) can be produced by a haloquinones/H2O2 system, a newly-found ●OH-generating system different from the classic Fenton system. Recently, we found that the degradation of priority pollutant pentachlorophenol by the classic Fe(II)-Fenton system could produce intrinsic CL, which was mainly dependent on the generation of chloroquinone intermediates. Analogous effects were observed for all nineteen chlorophenols, other halophenols and several classes of XAr, and a novel, rapid and sensitive CL-based analytical method was developed to detect these XAr and monitor their degradation kinetics. Interestingly, for those XAr with halohydroxyl quinoid structure, a Co(II)-mediated Fenton-like system could induce a stronger CL emission and higher degradation, probably due to site-specific generation of highly-effective ●OH. These findings may have broad chemical and environmental implications for future studies, which would be helpful for developing new analytical methods and technologies to investigate those ubiquitous XAr.

scholarly journals Uric Acid, Oxidative Stress and Inflammation in Chronic Heart Failure with Reduced Ejection Fraction

2015 ◽  
Vol 23 (4) ◽  
pp. 397-406 ◽  
Author(s):  
Adriana Iliesiu ◽  
Alexandru Campeanu ◽  
Daciana Marta ◽  
Irina Parvu ◽  
Gabriela Gheorghe
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Uric Acid ◽  
Chronic Heart Failure ◽  
Ejection Fraction ◽  
Xanthine Oxidase ◽  
Left Ventricular ◽  
Paraoxonase 1 ◽  
Lv Function ◽  
The Relationship

Abstract Background. Oxidative stress (OS) and inflammation are major mechanisms involved in the progression of chronic heart failure (CHF). Serum uric acid (sUA) is related to CHF severity and could represent a marker of xanthine-oxidase activation. The relationship between sUA, oxidative stress (OS) and inflammation markers was assessed in patients with moderate-severe CHF and reduced left ventricular (LV) ejection fraction (EF). Methods. In 57 patients with stable CHF, functional NYHA class III, with EF<40%, the LV function was assessed by N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) levels and echocardiographically through the EF and E/e’ ratio, a marker of LV filling pressures. The relationship between LV function, sUA, malondialdehyde (MDA), myeloperoxidase (MPO), paraoxonase 1 (PON-1) as OS markers and high sensitivity C-reactive protein (hsCRP) and interleukin 6 (IL-6) as markers of systemic inflammation was evaluated. Results. The mean sUA level was 7.9 ± 2.2 mg/dl, and 61% of the CHF patients had hyperuricemia. CHF patients with elevated LV filling pressures (E/e’ ≥ 13) had higher sUA (8.6 ± 2.3 vs. 7.3 ± 1.4, p=0.08) and NT-proBNP levels (643±430 vs. 2531±709, p=0.003) and lower EF (29.8 ± 3.9 % vs. 36.3 ± 4.4 %, p=0.001). There was a significant correlation between sUA and IL-6 (r = 0.56, p<0.001), MDA (r= 0.49, p= 0.001), MPO (r=0.34, p=0.001) and PON-1 levels (r= −0.39, p= 0.003). Conclusion. In CHF, hyperuricemia is associated with disease severity. High sUA levels in CHF with normal renal function may reflect increased xanthine-oxidase activity linked with chronic inflammatory response.

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