• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.465-470
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• 1994

This study was undertaken to measure the activity of myeloperoxidase and leukocyte peroxidase of hen. 70 hens were decapitated to observe the activity of enzymes according to ages. The activity of peroxidase by the Lowry's method with bovine serum albumin as standard. Gel filtration chromatography was carried out of sephacryl S-300 column. The results obtained were summarized as follows; 1. The mean of specific activity of myeloperoxidase and leukocyte peroxidase was 16.80(units/mg) and 15(units/mg), respectively. 2. The specific activity of myeloperoxidase in 35 days hen was significantly increased and showed almost the same level of activity to 350 days hen. 3. The specific activity of leukocyte peroxidase in 35 days hen was significantly increased and showed a little increased tendency from 210 days to 350 days hen. 4. On the sephacryl S-300 column chromatography, two separated peaks of myeloperoxidase activity were observed. The molecular weights of myeloperoxidase were 57,000 dalton and 13,700 dalton.

• Biomedical Science Letters
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• v.6 no.4
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• pp.281-288
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• 2000

Leukocyte activation with cardiac surgery procedures produces various iuflammatory substances and involves in postoperative pathophysiology. The present study was carried out to elucidate changes in leukocyte myeloperoxidase level and effect on the heart and lung during cardiac operation. Total leukocyte and differential counts in peripheral blood, myeloperoxidase (MPO) and troponin-T concentratiens (TnT) in coronary sinus blood, and pulmonary vascular resistance (PVR) were measured at preoperative and postoperative period. The parameters were compared between sampling periods, and relationship was investigated between MPO and each variable. At the end of operation, there were leukocytosis with neutrophilia (p＜0.01), and increases of MPO and TnT concentrations (p＜0.05), but decrease in PVR (p＜0.05). MPO had a positive correlation to TnT, total leukocyte, neutrophil, or operative times (p＜0.05), whereas PVR had a negative relationship to total leukocyte or neutrophil counts (p＜0.05). These results indicate that cardiac surgery leads to elevated liberations of myeloperoxidase from neutrophils and may harmfully affect myocardium.

• Journal of Medicine and Life Science
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• v.21 no.1
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• pp.15-19
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• 2024

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic necrotizing vasculitis that predominantly affects small vessels of the body. The two most common ANCAs are myeloperoxidase ANCA and proteinase 3 ANCA. Neurological manifestations are frequent in patients with AAV, including peripheral neuropathy, meningitis, and stroke. AAV-associated ischemic stroke usually affects small vessels supplying the white matter or brainstem. This case report details the presentation and treatment course of a 70-year-old man with rapidly progressive multiple intracranial large artery involvement attributed to myeloperoxidase ANCA-associated vasculitis. Despite treatment with high-dose steroids and a rituximab infusion, the patient developed new speech difficulties and respiratory distress, and brain imaging confirmed new stroke lesions with progressive multiple intracranial large cerebral artery involvement. The patient died from SARS-CoV-2 infection 4 months after the diagnosis. This case emphasized the rare presentation of rapidly progressive large vessel involvement in a patient with myeloperoxidase ANCA-associated vasculitis despite active immunotherapy.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.123-133
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• 1995

A number of tricyclic antidepressants appear to have inhibitory action on calmodulin. Although amitriptyline, imipramine and doxepine have been shown to inhibit calcium uptake, oxidative phosphorylation and ATPase activities, effects of amitriptyline, imipramine and doxepine on functional responses of human neutrophils have not been elucidated. In this study, effects amitriptyline, imipramine and doxepine on superoxide and hydrogen peroxide generation, myeloperoxidase release, leukocriene B4 formation and intracellular calcium level were investigated. Superoxide and hydrogen peroxide production in heat aggregated IgG-activated neutrophils were inhibited by amitriptyline, imipramine and doxepine. EDTA, EGTA, verapamil and bepredil inhibited heat aggregated IgG-induced superoxide production. Chlorpromazine, trifluoperazine, staurosporine and H-7 also inhibited it. PMA-induced superoxide production was inhibited by amitriptyline, imipramine, doxepine, chlorpromazine and H-7. Amitriptyline, imipramine, chlorpromazine and trifluoperazine inhibited the myeloperoxidase release by heat aggregated IgG. Productions of $LTB_4$, and 5-HETE in heat aggregated IgG-activated neutrophils were inhibited by amitriptyline, imipramine and doxepine. In neutrophils, elevation of intracellular calcium induced by heat aggregated IgG was inhibited by amitriptyline, imipramine, doxepine, chlorpromazine and EGTA, while verapamil slightly inhibited increase of intracellular calcium and H-7 did not inhibit it. These results suggest that the inhibitory effect of amitriptyline, imipramine and doxepine on respiratory burst, myeloperoxidase release and LTB4 production in heat aggregated IgG-activated neutrophils appears to be ascribed to the inhibition of calcium mobilization, calmodulin and protein kinase C.

• Toxicological Research
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• v.20 no.3
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• pp.187-193
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• 2004

This study aimed to determine the association of maternal oxidative stress and adverse pregnancy outcome with serum vitamin C concentration and a myeloperoxidase (MPO) genetic polymorphism during pregnancy. We investigated 450 pregnant women who visited Ewha Womans University Hospital for prenatal care during gestational weeks 24～28. During the second trimester, we measured serum vitamin C levels and urinary 8-hydroxyde-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) as an oxidative stress biomarker. We determined the presence of a maternal MPO polymorphism (G-to-A substitution at nucleotide 463) using a PCR-RFLP assay. We compared the level of oxidative stress and birth weight with the vitamin C concentration and the presence of the MPO polymorphism. The mean level of maternal oxidative stress tended to be higher and the birth weight lower for MPO type A/A than for types A/G and G/G. Vitamin C levels above the 75 percentiles were associated with reduced concentrations of urinary MDA and 8-OHdG but increased birth weight. Our data demonstrate that oxidative stress and neonatal birth weight are associated with the MPO genetic polymorphism, with the association modified by the maternal vita-min C levels.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.58-62
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• 2002

The underlying mechanism by which the reflux of gastric juice elicits oesophagitis remaind unclear. To investigate inflammatory response to HCI in tissue of esophagus and lower esophageal sphincter experimental esophagitis was elicited by perfusion of 0.1 N HCI in cats. There was no difference in phospholipase $A_2$ (PLA$_2$) activity of tissue between control and esophagitis. Myeloperoxidase activity in esophagitis was significantly greater than that of control. However histamine content in esophageal mucosa of esophagitis was significantly smaller than that of control. These finding suggest that inflammatory response to HCI in esophagitis is related to changes of myeloperoxidase activity and histamine rather than change of PLA$_2$ activity.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.733-740
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• 1995

This investigation was undertaken to determine the relationship between the amount of polymorphonuclear leukocyte(PMN) enzyme myeloperoxidase(MPO) in gingival crevicular fluid(GCF) collected from active or control site and gingival disease status described by clinical indices(gingival index, papillary bleeding index, pocket depth, periotron unit). The results were as follows : 1. MPO activity/site was greater at active sites than at control sites. 2. According to increasing the clinical parameters, MPO/sites was higher statistically (P<0. 01, P<0.05). 3. High MPO(unit/site) groups was higher statistically than low MPO(unit/site) groups in various clinical parameters. 4. Correlation coefficients between MPO(unit/site) and GI, MPO($unit/{\mu}l$ GCF) and periotron unit were 0.4782, -0.5901, respectively.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.115-122
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• 1995

Effects of staurosporine, genistein and pertussis toxin on superoxide and HOCl production in C5a- or PMA-activated neutrophils were investigated. A C5a-induced superoxide and $H_2O_2$ production was inhibited by staurosporine, genistein and pertussis toxin. The stimulatory effect of PMA was inhibited by staurosporine but was not affected by pertussis toxin, whereas it was further promoted by genistein. Staurosporine and genistein inhibited superoxide production by sodium fluoride, but pertussis toxin did not affect it. PMA-induced $H_2O_2$ production was inhibited by staurosporine but was not affected by pertussis toxin. Genistein did not show a stimulatory effect on PMA-induced $H_2O_2$ production. Staurosporine and pertussis toxin inhibited HOCl production by C5a- or PMA, whereas genistein stimulated it. C5a-or PMA-induced myeloperoxidase release was inhibited by genistein, in this response the effect of pertussis toxin was not detected. Staurosporine did not affect the stimulatory effect of PMA on the release. Myeloperoxidase activity was markedly increased by genistein but was not affected by staurosporine and pertussis toxin. These results indicate that the respiratory burst of neutrophils may be regulated by protein kinase C and protein tyrosine kinase. Superoxide production induced by the direct activation of protein kinase C might be affected by protein tyrosine kinase oppositely. Genistein probably pro-motes HOCl production by activating myeloperoxidase.

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.38.2-38.2
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• 2004

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3259-3264
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• 2010

A label-free amperometric immunosensor has been proposed for the detection of myeloperoxidase (MPO) in human serum. To fabricate such an immunosensor, a composite film consisting of N,N-dimethylformamide (DMF), multiwall carbon nanotubes (MWCNTs) and 1-ethyl-3-methyl imidazolium tetrafluoroborate ($EMIMBF_4$) suspension was initially formed on a glassy carbon electrode (GCE). Then cerium dioxide ($CeO_2$) dispersed by chitosan was coated on the GCE. After that, MPO antibodies (anti-MPO) were attached onto the nano$CeO_2$ surface. With a noncompetitive immunoassay format, the antibody-antigen complex formed between the immobilized anti-MPO and MPO in sample solution. The immunosensor was characterized by cyclic voltammetry, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The factors influencing the performance of the immunosensor were studied in detail. Under optimal conditions, the current change before and after the immunoreaction was proportional to MPO concentration in the range of 5 to $300\;ng\;mL^{-1}$ with a detection limit of $0.2\;ng\;mL^{-1}$.