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Raddi, Maria Stella Gonçalves
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Id: lil-547638
Autor: Pereira, Débora Helena; Kitagawa, Rodrigo Rezende; Raddi, Maria Stella Gonçalves; Fonseca, Luiz Marcos da; Ximenes, Valdecir Farias.
Título: The triad Indole-3-Acetic Acid Ethyl Ester/Esterase/Horseradish Peroxidase as a new cytotoxic Prodrug/Enzyme combination
Fonte: Appl. cancer res;30(1):204-209, Jan.-Mar. 2010. ilus.
Idioma: en.
Resumo: The antibody-directed enzyme prodrug therapy (ADEPT) is a means of restricting the action of toxic drugs to the tumor site. The enzyme/prodrug pair horseradish peroxidase (HRP)/indole-3-acetic acid (IAA) has been studied as a combination with potential application in ADEPT strategies. In this combination, the non-toxic plant hormone IAA is activated to cytotoxic species by the catalytic action of HRP. Objective: We studied the use of the ethyl ester of IAA as a new prodrug that could be activated by two enzymes, HRP and esterase. Methods: The oxidation of IAA and its ethyl ester, catalyzed by HRP, was monitored by the consumption of dioxygen and liquid chromatography. The cytotoxicity of IAA and its ethyl ester in combination with HRP and esterase was assessed using the lineage McCoy cells through the trypan blue and neutral red assays. Results: We found that HRP was not able to catalyze the oxidation of IAA-ethyl ester in the absence of an additional esterase. Hence, the potential cytotoxicity of the IAA-ethyl ester could be controlled by sequential treatment with esterase, to liberate the carboxyl group, and HRP, for oxidation and generation of cytotoxic species. We present evidence for the potential application of the combination IAA-ethyl ester/esterase/horseradish peroxidase as a new ADEPT, GDEPT or related strategy. Conclusions: We suggest that this technique could provide more selectivity in the generation of cytotoxic drugs at tumor sites.
Descritores: Esterases
Peroxidase do Rábano Silvestre
-Protocolos de Quimioterapia Combinada Antineoplásica
Responsável: BR30.1 - Biblioteca


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Id: biblio-1010412
Autor: Mohamed, Saleh A; Al-Harbi, Majed H; Almulaiky, Yaaser Q; Ibrahim, Ibrahim H; El-Shishtawy, Reda M.
Título: Immobilization of horseradish peroxidase on Fe3O4 magnetic nanoparticles
Fonte: Electron. j. biotechnol;27:84-90, May. 2017. graf, ilus, tab.
Idioma: en.
Resumo: Background: Iron magnetic nanoparticles have attracted much attention. They have been used in enzyme immobilization because of their properties such as product is easily separated from the medium by magnetic separation. The present work was designed to immobilize horseradish peroxidase on Fe3O4 magnetic nanopraticles without modification. Results: In the present study, horseradish peroxidase (HRP) was immobilized on non-modified Fe3O4 magnetic nanoparticles. The immobilized HRP was characterized by FT-IR spectroscopy, scanning electron microscopy, and energy dispersive X-ray. In addition, it retained 55% of its initial activity after 10 reuses. The optimal pH shifted from 7.0 for soluble HRP to 7.5 for the immobilized HRP, and the optimal temperature shifted from 40°C to 50°C. The immobilized HRP is more thermostable than soluble HRP. Various substrates were oxidized by the immobilized HRP with higher efficiencies than by soluble HRP. Km values of the soluble and immobilized HRP were 31 and 45 mM for guaiacol and 5.0 and 7.0 mM for H2O2, respectively. The effect of metals on soluble and immobilized HRP was studied. Moreover, the immobilized HRP was more stable against high concentrations of urea, Triton X-100, and isopropanol. Conclusions: Physical immobilization of HRP on iron magnetic nanoparticles improved the stability toward the denaturation induced by pH, heat, metal ions, urea, detergent, and water-miscible organic solvent.
Descritores: Enzimas Imobilizadas/química
Óxido Ferroso-Férrico/química
Peroxidase do Rábano Silvestre/química
-Solubilidade
Espectrometria por Raios X
Temperatura
Microscopia Eletrônica de Varredura
Espectroscopia de Infravermelho com Transformada de Fourier
Enzimas Imobilizadas/metabolismo
Nanopartículas/química
Peroxidase do Rábano Silvestre/metabolismo
Concentração de Íons de Hidrogênio
Responsável: CL1.1 - Biblioteca Central


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Id: lil-678082
Autor: Baldión Elorza, Paula Alejandra; Viteri Lucero, Laura Nathalia; Lozano Torres, Edilberto.
Título: Efecto de la peroxidasa sobre la resistencia de unión de una resina compuesta al esmalte dental posblanqueamiento / Effect of peroxidase on composite resin adhesion to dental enamel after whitening
Fonte: Rev. Fac. Odontol. Univ. Antioq;24(1):8-21, jul.-dic. 2012. ilus, tab.
Idioma: es.
Resumo: Introducción: se ha reportado que el oxígeno residual liberado por los agentes blanqueadores interfieren en la adhesión de las resinas compuestas a la estructura dental, razón por la cual se tiene como objetivo comparar la resistencia de unión al corte (RUC) de una resina compuesta al esmalte dental posblanqueamiento con peróxido de hidrógeno al 38%, antes y después de tratar la superficie con la enzima peroxidasa previo a la adhesión. Métodos: se seleccionaron 45 premolares humanos sanos, divididos entres grupos de 15 dientes cada uno. Grupo 1: control (solo adhesión); grupo 2: blanqueamiento y adhesión; grupo 3: blanqueamiento, aplicación de peroxidasa y adhesión. Posterior al tratamiento se midió la RUC en la máquina de ensayos Shimadzu, para determinar diferencia estadísticamente significativa entre los tres grupos con nivel de confianza de 95% y con valor de p < 0,05. Resultados: el grupo control obtuvo la RUC de 12,8 Mpa (± 3,2), el grupo con blanqueamiento tuvo el promedio de 3,5 Mpa (± 1,43) y el grupo con blanqueamiento y aplicación de peroxidasa presentó promedio de 12,2 Mpa (± 3,12). Conclusiones: los valores de RUC disminuyeronsignificativamente con la aplicación de peróxido de hidrógeno al 38%, sin embargo, se logró el aumento significativo al aplicar la peroxidasa previa a la adhesión.

Introduction: some reports suggest that residual oxygen released by whitening agents interfere with composite resinadhesion to dental structure. The objective of this study is therefore to compare composite resins' shear bond strength to dental enamel after whitening using 38% hydrogen peroxide pre- and post- treatment with peroxidase enzyme before adhesion. Methods: a total of 45 healthy human premolars were selected and divided into three groups of 15 teeth each. Group 1: control group (only adhesion); group 2: whitening and adhesion; group 3: whitening, application of peroxidase, and adhesion. After treatment, shear bond strength was measured with a Shimadzu testing machine in order to determine significant statistical differences among the three groups, with a confidence level of 95% and p < 0.05. Results: the control group obtained a shear bond strength of 12.8Mpa (± 3.2), the whitening group showed an average 3.5 Mpa (± 1.43), and the group treated with whitening and peroxidase presented an average 12.2 Mpa (± 3.12). Conclusions: shear bond strength values significantly decreased with application of 38% hydrogen peroxide; however, a significant increase was also obtained byapplying peroxidase before adhesion.
Descritores: Peroxidase do Rábano Silvestre
Peróxido de Hidrogênio
Clareamento Dental
Responsável: CO66.1 - Biblioteca


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Texto completo SciELO Chile
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Id: lil-504122
Autor: La Rotta Hernández, Camilo Enrique; Werberich, Diogo Simon; Mattos, Marcio Contrucci Saraiva de; D'Elia, Eliane.
Título: Electrogeneration of hydrogen peroxide applied to the peroxide-mediated oxidation of (R)-limonene in organic media
Fonte: Electron. j. biotechnol;10(4):521-535, oct. 2007.
Idioma: en.
Resumo: Horse radish peroxidase (HRP) from Armoracia rusticana catalyses the oxidation of (R)-limonene into the oxidized derivatives carveol and carvone. This study compares the direct addition (DA) of hydrogen peroxide with its continuous electrogeneration (EG) during the enzymatic oxidation of (R)-limonene. Reaction mixtures containing HRP, (R)-limonene as substrate, and hydrogen peroxide, added directly or electrogenerated, in 100 mM sodium-potassium phosphate buffer pH 7.0, at 25ºC were studied. Two electrochemical systems for the hydrogen peroxide electrogeneration were evaluated, both containing as auxiliary electrode (AE) a platinum wire and saturated calomel electrode (SCE) as reference. Reticulated vitreous carbon foam (RVCF) and an electrolytic copper web (CW) were evaluated as working electrodes (WE). Results were compared in terms of hydrogen peroxide electrogeneration, (R)-limonene residual concentration or conversion and product selectivity. Best results in terms of maximum H2O2 concentration (1.2 mM) were obtained using the CW electrode at -620 mV SCE, and continuous aeration. Use of the EG system under optimized conditions, which included the use of acetone (30% v/v) as a cosolvent in a 3 hrs enzymatic reaction, lead to a 45% conversion of (R)-limonene into carveol and carvone (2:1). In comparison to the results obtained with DA, the use of EG also improved the half-life of the enzyme.
Descritores: Cicloexanos/química
Eletroquímica/métodos
Peroxidase do Rábano Silvestre/química
Peróxido de Hidrogênio/química
Terpenos/química
-Armoracia/química
Catálise
Cromatografia Gasosa
Eletroquímica/instrumentação
Monoterpenos/química
Oxirredução
Solventes
Espectrofotometria
Responsável: CL1.1 - Biblioteca Central


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Madeira, Miguel Carlos
Id: lil-321989
Autor: Rizzolo, Roelf Justino Cruz; Madeira, Miguel Carlos; Oliveira, José Américo; Martins, Ariovaldo Antônio.
Título: Localizaçäo dos aferentes primários que inervam a articulaçäo temporomandibular do macaco Cebus Apella / Localization of primary afferent neurons that innervate the temporomandibular joint in Cebus monkey
Fonte: Rev. odontol. UNESP;30(2):291-300, jul.-dez. 2001. ilus.
Idioma: pt.
Resumo: A origem da inervaçäo sensitiva da articulaçäo temporomandibular (ATM) é motivo de controvérsia. Livros clássicos de anatomia indicam que os corpos neuronais responsáveis por essa inervaçäo estariam localizados no núcleo mesencefálico do nervo trigêmeo. Entretanto, estudos realizados em mamíferos inferiores indicam que esses neurônios estariam localizados no gânglio trigeminal. Neste trabalho, empregando a técnica de traçado de vias nervosas mediante a utilizaçäo de peroxidase do rábano silvestre (HRP), estudou-se a inervaçäo da ATM do primata Cebus apella. Os resultados mostram que os corpos neuronais responsáveis pela inervaçäo sensitiva da ATM nesses animais se localizam apenas no gânglio trigeminal
Descritores: Peroxidase do Rábano Silvestre
Articulação Temporomandibular
Nervo Trigêmeo
-Cebus
Responsável: BR186.1 - Biblioteca Honório Monteiro


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Id: lil-319780
Autor: Rehen, S. K; Linden, R.
Título: Apoptosis in the developing retina: paradoxical effects of protein synthesis inhibition
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;27(7):1647-1651, Jul. 1994.
Idioma: en.
Resumo: Cell death by apoptosis is usually characterized as an active process that requires protein and RNA synthesis. The requirement of protein synthesis for the degeneration of ganglion cells and other cell types was studied in neural retinae explanted from the eyes of newborn rats. Ganglion cells were detected by the presence of retrogradely transported horseradish peroxidase injected into the superior colliculus. Apoptotic cells were recognized by their condensed and deeply stained chromatin. The data show that the death of ganglion cells, whose axons are damaged when preparing the explants, is blocked or delayed by protein synthesis inhibitors. In contrast, the blockade of protein synthesis produced cell death with apoptotic morphology in the neuroblastic layer of the same retinae. The results suggest the operation in the developing retina of both a program of apoptosis dependent on the synthesis of killer proteins, and a latent mechanism of apoptosis that is normally blocked by repressor proteins.
Descritores: Apoptose
Inibidores da Síntese de Proteínas/farmacologia
Retina
-Animais Recém-Nascidos
Morte Celular
Cicloexilaminas
Peroxidase do Rábano Silvestre
Degeneração Neural
Retina
Células Ganglionares da Retina
Limites: Animais
Ratos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-285438
Autor: Lema, Carolina; Carvajal, Roger; Pantoja, María Rosa; Sánchez, Lilia.
Título: Evaluación de la especie raphanus sativus como fuente alternativa para la purificación de peroxidasa y su utilización en pruebas de inmunodiagnóstico / Evaluation of the species Raphanus sativirus is alternative source peroxidasa purificaton and its use in inmuodiagnostic tests
Fonte: Biofarbo;4(4):5-13, dic. 1995. ilus.
Idioma: es.
Resumo: Se purificó Peroxidasa a partir de 3 fuentes vegetales: Raphanus sativus (rábano común), Bolivian radish (rábano procedente de semillas mejoradas) y Amoracia lapathifolia (horse-radish ó raíz picante). Se obtuvo un extracto crudo de cada especie, se efectuó una precipitación etanólica, separación de fracciones activas de peso molecular semejante mediante cromatografía de exclusión molecular y aislamiento de sub-fracciones activas en función a su comportamiento acido básico frente a un intercambiador aniónico. La sub-fracción de actividad enzimática específica más elevada (aislada a partir de la variedad Bolivian radish, aproximadamente 9 y 5 veces superior en relación a las sub-fracciones semejantes de rábano común y de raíz picante), fue conjugado satisfactoriamente a la anti-IgG humana (producida en conejo), lo cual alentaría la posibilidad de su aplicación en las pruebas de inmunodiagnóstico. Se partió de 25 gr. de cada vegetal (tubérculos y raices) obteniendose aproximadamente 1 mg. de enzima activa
Descritores: EVALUATION
Raphanus
-Bolívia
Peroxidase do Rábano Silvestre
Responsável: BO3.1 - Biblioteca


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Id: lil-225971
Autor: Bravo, Hermes; Inzunza, Oscar.
Título: Effect of pre and postnatal retinal deprivation on the striate-peristriate cortical connections in the rat
Fonte: Biol. Res;27(1):73-7, 1994. ilus, tab, graf.
Idioma: en.
Resumo: The tangential distribution of the striate-peristriate cortical connections in normal, postnatally eye nucleated and congenitally anophthalmic rats, was studied after a single injection of wheat germ agglutinin conjugated with horseradish peroxidase into the striate cortex. The typical normal pattern of separate fields in the peristriate cortex is altered in eye enucleated animals, in such a way that their areal distribution in the cerebral cortex is increased and each field tends to fuse with the adjacent one. This process is more marked in anophthalmic animals, a finding that is in agreement with the notion that ganglion cells exert their influence before the visual pathway is functional
Descritores: Córtex Cerebral/anatomia & histologia
Retina/anatomia & histologia
Privação Sensorial
Córtex Visual/anatomia & histologia
-Anoftalmia
Córtex Cerebral/citologia
Enucleação Ocular
Peroxidase do Rábano Silvestre
Ratos Sprague-Dawley
Córtex Visual/citologia
Vias Visuais/anatomia & histologia
Aglutininas do Germe de Trigo
Limites: Animais
Ratos
Tipo de Publ: Estudo Comparativo
Responsável: BR1.1 - BIREME


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Id: lil-224082
Autor: Cruz-Rizzolo, Roelf Justino; Derogis, Alessandra; Lorenzato, Fábio.
Título: Estudo comparativo de diferentes conjugados de HRP no estudo das vidas neurais das estruturas bucofaciais / Comparative study of free HRP and HRP conjugates in the examination of the connectivity between orofacial structures and the central nervous system
Fonte: Rev. odontol. UNESP;26(2):461-70, jul.-dez. 1997. ilus.
Idioma: pt.
Resumo: A utilizaçäo de neurotraçadores tem revolucionado, nas últimas três décadas, o conhecimento sobre o padräo de conexöes entre as estruturas periféricas e o sistema nervoso. Entre os neurotraçadores, a peroxidase do rábano silvestre (HRP) tem sido a mais utilizada. Mais recentemente, combinaçöes desse neurotraçador com a aglutinina do germe do trigo (WGA) ou com a subunidade B da toxina colérica (CTB) têm demonstrado um considerável aumento na captaçäo dos conjugados resultantes (HRP-WGA, CTB-HRP), com melhora sensível na capacidade de traçar conexöes neurais. No presente experimento, foram testados ambos os cojugados e o HRP livre no contexto de um amplo estudo sobre o núcleo do nervo hipoglosso do rato, responsável pela inervaçäo motora da língua. Para isto, foram injetados na metade posterior da língua de cada rato 10 µl de HRP (20 por cento) ou 10 µl de CTB-HRP (0,15 por cento de toxina colérica + 12 por cento HRP) ou 10 µl de HRP-WGA (5 por cento de WGA + 30 por cento HRP). Após um período de sobrevivência de 48 horas, os animais foram perfundidos com uma soluçäo de aldeídos e, posteriormente, os encéfalos foram cortados em criostato (40 µm). Os cortes foram submetidos à reaçäo histoquímica do HRP, utilizando-se a tetrametilbenzidina como cromógeno. Os resultados indicam que, tanto desde o ponto de vista qualitativo como até quantitativo, os conjugados säo mais eficientes para evidenciar conexöes neurais que o HRP livre. Os conjugados HRP-WGA e CTB-HRP apresentam qualidades semelhantes, embora este último seja mais eficiente para evidenciar detalhes na arborizaçäo dendrítica e características morfológicas gerais dos motoneurônicos. Essa superioridade do conjugado CTB-HRP pode estar relacionada com a abundância de gangliosídeos do tipo GM1 na membrana pré-sináptica das junçöes neuromusculares. Esses gangliosídeos formam um grupo de receptores específicos para componentes da subunidade B da toxina colérica, o que potencializa a captaçäo da mesma pelos terminais axônicos
Descritores: Peroxidase do Rábano Silvestre
Conjugado Aglutinina do Germe de Trigo-Peroxidase do Rábano Silvestre
-Sistema Nervoso
Responsável: BR186.1 - Biblioteca Honório Monteiro


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Id: lil-176727
Autor: Abreu, Miguel; Kicliter, Earl; Lugo-Garcia, Nidza.
Título: Displaced amacrine cells in the ganglion cell layer of the ground squirrel retina
Fonte: P. R. health sci. j;12(2):137-41, jun. 1993.
Idioma: en.
Resumo: In some mammals a large portion of the retinal neurons of the ganglion cell layer are not ganglion cells. These neurons, lacking axons which pass to the brain via the optic nerve, are termed displaced amacrine cells. The present study assessed the number of displaced amacrine cells in the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). We compared the number of labeled cells in the ganglion cell layer after HRP injection of optic tracts and target nuclei with the total number of neurons in the ganglion cell layer. We conclude that approximately one half of the neurons in the ganglion cell layer are displaced amacrine cells, the other one half are ganglion cells. The displaced amacrine cells are on the average smaller than the ganglion cells. Our results provide a rationale for renewed study of relation of ganglion cell morphology and physiological functional type in this species
Descritores: Células Ganglionares da Retina/citologia
Retina/citologia
Sciuridae/anatomia & histologia
-Peroxidase do Rábano Silvestre
Limites: Animais
Tipo de Publ: Estudo Comparativo
Responsável: BR1.1 - BIREME



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