Peroxidase Iodide
Mostrando 1-12 de 27 artigos, teses e dissertações.
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1. Screening and identification of TPO gene mutations in patients with partial or total iodide organification defect / Hipotireoidismo congênito: rastreamento e identificação de mutações no gene TPO em pacientes com defeito parcial ou total de incorporação de iodeto
Introdução: O hipotireoidismo congênito é a causa mais frequente de retardo mental evitável, cuja prevalência é de 1/3000 crianças nascidas vivas. Pode ser causado por disgenesia tireoideana (80% dos casos) ou por defeitos de síntese hormonal (20% restantes). As disormonogêneses tem sido associadas a mutações nos genes da tireoperoxidase (TPO), t
Publicado em: 2009
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2. Aspectos genéticos do hipotireoidismo congênito
Hipotireoidismo congênito (HC) afeta cerca de 1:3000 a 1:4000 recém-nascidos (RN). Numerosos genes são essenciais, tanto para o desenvolvimento normal do eixo hipotálamo-hipófise-tireóide quanto para a produção hormonal, e estão associados ao HC. Cerca de 85% do hipotireoidismo primário é denominado disgenesia tireoidiana e evidências sugerem que
Arquivos Brasileiros de Endocrinologia & Metabologia. Publicado em: 2004-02
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3. Anticorpos anti-tiróide: aspectos metodológicos e importância diagnóstica
Desde sua descrição, há mais de 40 anos, a pesquisa de anticorpos (Ac) contra antígenos (Ag) tiroideanos tem tido papel importante no diagnóstico da patologia tiroideana. A tiróide é freqüentemente acometida por doenças autoimunes, daí o interesse pela definição dos Ag tiroideanos que podem estar envolvidos no processo. O primeiro Ag reconhecido
Arquivos Brasileiros de Endocrinologia & Metabologia. Publicado em: 2003-10
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4. Thyroid peroxidase activity is inhibited by amino acids
Normal in vitro thyroid peroxidase (TPO) iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml) or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml). A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml) and some amino acids (cysteine, tryptophan and methionine, 50 µM each) also inhibited the TPO iodide o
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-03
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5. Antifungal Effects of Peroxidase Systems
In the presence of hydrogen peroxide and either potassium iodide, sodium chloride, or potassium bromide, purified human myeloperoxidase was rapidly lethal to several species of Candida. Its candidacidal activity was inhibited by cyanide, fluoride, and azide, and by heat inactivation of the enzyme. A hydrogen peroxidegenerating system consisting of d-amino ac
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6. Some enzymatic characteristics of eosinophil peroxidase from patients with eosinophilia and from healthy donors.
Some enzymatic characteristics of human eosinophil peroxidase were compared with those of human myeloperoxidase. Both enzymes catalyzed the oxidation of iodide by hydrogen peroxide. This assay proved to be very sensitive; the activity of 100 eosinophils/ml could be measured. The position of the pH optimum of this reaction was linearly dependent on the logari
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7. Mycoplasmacidal Activity of Peroxidase-H2O2-Halide Systems 1
A mycoplasmacidal system consisting of myeloperoxidase (MPO)-containing granules, H2O2, and a halide is described. In all parameters measured, it appears to be identical to the MPO-H2O2-halide bactericidal system previously reported. It has a pH optimum of approximately 5.5 and an optimal MPO:H2O2 ratio of 1:25. The halide requirement can be satisfied by eit
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8. Cofactor Role of Iodide in Peroxidase Antimicrobial Action Against Escherichia coli
The mechanism of antimicrobial activity of the peroxidase-hydrogen peroxide (H2O2)-iodide (I−) system was investigated. Inhibition of respiration and loss of viability of Escherichia coli were used as measures of antimicrobial activity. Because the bacteria destroyed H2O2, peroxidase antimicrobial action depended on the competition for H2O2 between the bac
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9. Oxidation of Escherichia coli Sulfhydryl Components by the Peroxidase-Hydrogen Peroxide-Iodide Antimicrobial System
The chemical modification of bacterial components was studied following incubation of Escherichia coli with the peroxidase-hydrogen peroxide (H2O2)-iodide (I−) antimicrobial system or with iodine (I2). The oxidation of cell sulfhydryls and the iodination of cell components were measured. Both the peroxidase system and I2 oxidized sulfhydryls. When the I−
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10. Susceptibility of Escherichia coli to Bactericidal Action of Lactoperoxidase, Peroxide, and Iodide or Thiocyanate
The bactericidal action that results from lactoperoxidase-catalyzed oxidation of iodide or thiocyanate was studied, using Escherichia coli as the test organism. The susceptibility of intact cells to bactericidal action was compared with that of cells with altered cell envelopes. Exposure to ethylenediaminetetraacetic acid, to lysozyme and ethylenediaminetetr
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11. Virucidal effects of glucose oxidase and peroxidase or their protein conjugates on human immunodeficiency virus type 1.
Glucose oxidase and peroxidase (lactoperoxidase or myeloperoxidase) are virucidal to human immunodeficiency virus type 1 (HIV-1) in the presence of sodium iodide, as assessed by the loss of viral replication in a syncytium-forming assay or by the inhibition of cytopathic effects on infected cells. In the presence of low concentrations of sodium iodide, five
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12. Role of the Phagocyte in Host-Parasite Interactions XXIV. Aldehyde Generation by the Myeloperoxidase-H2O2-Chloride Antimicrobial System: a Possible In Vivo Mechanism of Action
Myeloperoxidase (MPO), H2O2, and chloride ions in the presence of bacteria form aldehydes and are bactericidal. The use of heat-inactivated MPO prevented both killing and aldehyde generation. Decarboxylation and deamination of carboxyl and amino group substrates arising from the bacterial surface may participate in the reaction which yields aldehydes. Bacter