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Id: biblio-1017370
Autor: Chang, Ermei; Zhang, Jing; Deng, Nan; Yao, Xiamei; Liu, Jianfeng; Zhao, Xiulian; Jiang, Zeping; Shi, Shengqing.
Título: Transcriptome differences between 20- and 3, 000-year-old Platycladus orientalis reveal that ROS are involved in senescence regulation
Fonte: Electron. j. biotechnol;29:68-77, sept. 2017. tab, graf.
Idioma: en.
Projeto: National Non-Profit Research Institutions of Chinese Academy of Forestry.
Resumo: Background: Platycladus orientalis has an extremely long life span of several thousands of years, attracting great interests in the mechanisms involved in such successful senescence regulation and resistance at physiological and molecular levels. Results: The levels of reactive oxygen species (ROS) were higher in 3,000-year-old than in 20-year-old P. orientalis, and the activities of GR and GSH demonstrated the same trend. We produced and analyzed massive sequence information from pooled samples of P. orientalis through transcriptome sequencing, which generated 51,664 unigenes with an average length of 475 bp. We then used RNA-seq analysis to obtain a high-resolution age­course profile of gene expression in 20- and 3,000-year-old P. orientalis individuals. Totally, 106 differentially expressed genes were obtained, of which 47 genes were downregulated and 59 upregulated in the old tree. These genes were involved in transcription factors, hormone-related responses, ROS scavengers, senescence-related responses, stress response, and defense and possibly play crucial roles in tackling various stresses in the 3,000-year-old P. orientalis during its life time. The expression patterns of genes related to ROS homeostasis further indicated that the high ability of ROS scavenging could be helpful for the 3,000-year-old P. orientalis to resist senescence. Conclusions: This study provides a foundation for the elucidation of senescence resistance through molecular studies and the discovery of useful genes in P. orientalis.
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1008175
Autor: Chang, Lingmo; Sun, Huan; Yang, Hua; Wang, Xuehua; Su, Zhizhe; Chen, Fang; Wei, Wei.
Título: Over-expression of dehydroascorbate reductase enhances oxidative stress tolerance in tobacco
Fonte: Electron. j. biotechnol;25:1-8, ene. 2017. graf, ilus.
Idioma: en.
Projeto: National Science Foundation of China; . Application of Sichuan Province Based Project. 31071448; 2014JY0051.
Resumo: Background: Ascorbic acid (Asc) is one of the most abundant antioxidants and it serves as a major contributor to protect plants against oxidative damage. Plants use two enzymes that participate in the metabolic recycling of Asc. One of these two enzymes is dehydroascorbate reductase (DHAR). It directly regenerates Asc from its oxidized state and thus prevents Asc from being irreversibly hydrolyzed to 2, 3-diketogulonic acid. This study aimed to examine whether over-expression of DHAR leads to an enhanced oxidative stress tolerance in tobacco plants. Results: In this study, we functionally characterized a novel JcDHAR gene from Jatropha curcas and found via quantitative RT-PCR analysis that JcDHAR can be induced with H2O2, salt and PEG stresses. The DHAR activities of transgenic tobacco plants increased from 2.0 to 5.3 fold compared to wild-type plants. As a result, the transgenic plants displayed enhanced tolerance to oxidative stress. Conclusions: Our results indicate that JcDHAR expression can effectively enhance the tolerance to oxidative stress in plants.
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1003646
Autor: Sandoval D, Bárbara; Reyes R, Tatiana; Oyarzún G, Manuel.
Título: Mecanismos de los efectos nocivos para la salud de la contaminación atmosférica proveniente de incendios forestales / Mechanisms of noxious effects of wildfire air pollution over human health
Fonte: Rev. chil. enferm. respir;35(1):49-57, mar. 2019. graf.
Idioma: es.
Resumo: Los incendios forestales representan un problema creciente de la salud pública a nivel mundial, especialmente para la población más vulnerable (niños, ancianos, embarazadas y portadores de enfermedades cardiovasculares o respiratorias crónicas) expuesta al humo y a otros contaminantes aéreos. A diferencia de la contaminación atmosférica habitual de grandes urbes, aquella derivada de los incendios forestales tiene una composición diferente y su ocurrencia es esporádica y difícil de prever. La exposición a contaminantes atmosféricos derivados de incendios forestales se asocia a aumento de la morbilidad respiratoria y cardiovascular, mediada por una respuesta inflamatoria pulmonar y sistémica, estrés oxidativo y disfunción endotelial. En sujetos expuestos a humo de incendios forestales se ha observado un aumento en la producción de citoquinas pro-inflamatorias, activación endotelial y disfunción del sistema nervioso autónomo, que produce daño tisular, aumento de los mecanismos protrombóticos, aumento de la presión arterial y cambios en el ritmo cardiaco. Esta revisión analiza los mecanismos que han sido involucrados en generar efectos nocivos para la salud de seres humanos expuestos a material particulado y gases emanados de incendios forestales.

Wildfires represent a growing global public health issue, especially to the most vulnerable segment of the population (children, old people, pregnant women, patients with cardiovascular or respiratory diseases) exposed to smoke and other air borne contaminants generated from these events. In contrast to great cities ' usual atmospheric pollution, that derives from forest fires differ in composition and its occurrence is sporadic and usually unpredictable. Exposure to atmospheric pollutants derived from forest fires has been associated to increased respiratory and cardiovascular morbidity, mediated by an inflammatory systemic response, oxidative stress and endothelial dysfunction. In people exposed to forest fire smoke an increased production of pro-inflammatory cytokines, endothelial activation and autonomic nervous system dysfunction has been observed, that leads to tissue injury, increased prothrombotic response, increased blood pressure and changes in heart rhythm. This review analyzes the mechanisms that have been involved in generating harmful health effects in humans exposed to inhaled particulate matter and gases steaming from wildfires.
Responsável: CL1.1 - Biblioteca Central


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Leonart, Maria Suely Soares
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Id: lil-670460
Autor: Henneberg, Railson; Otuki, Michel Fleith; Furman, Aline Emmer Ferreira; Hermann, Priscila; Nascimento, Aguinaldo José do; Leonart, Maria Suely Soares.
Título: Protective effect of flavonoids against reactive oxygen species production in sickle cell anemia patients treated with hydroxyurea
Fonte: Rev. bras. hematol. hemoter;35(1):52-55, 2013. ilus.
Idioma: en.
Resumo: OBJECTIVE: The aim of this study was to evaluate the protective effects of quercetin, rutin, hesperidin and myricetin against reactive oxygen species production with the oxidizing action of tert-butylhydroperoxide in erythrocytes from normal subjects and sickle cell anemia carriers treated with hydroxyurea. METHODS: Detection of intracellular reactive oxygen species was carried out using a liposoluble probe, 2',7'-dichlorfluorescein-diacetate (DCFH-DA). A 10% erythrocyte suspension was incubated with flavonoids (quercetin, rutin, hesperidin or myricetin; 30, 50, and 100 µmol/L), and then incubated withtert-butylhydroperoxide (75 µmol/L). Untreated samples were used as controls. RESULTS: Red blood cell exposure to tert-butylhydroperoxide resulted in significant increases in the generation of intracellular reactive oxygen species compared to basal levels. Reactive oxygen species production was significantly inhibited when red blood cells were pre-incubated with flavonoids, both in normal individuals and in patients with sickle cell anemia. Quercetin and rutin had the highest antioxidant activity, followed by myricetin and hesperidin. CONCLUSION: Flavonoids, in particular quercetin and rutin, showed better antioxidant effects against damage caused by excess reactive oxygen species characteristic of sickle cell anemia. Results obtained with patients under treatment with hydroxyurea suggest an additional protective effect when associated with the use of flavonoids.
Responsável: BR408.1 - Biblioteca da Faculdade de Medicina - BFM


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Id: biblio-894933
Autor: Oliveira, Jessica Silva Santos de; Santos, Gabriela da Silva; Moraes, João Alfredo; Saliba, Alessandra Mattos; Barja-Fidalgo, Thereza Christina; Mattos-Guaraldi, Ana Luíza; Nagao, Prescilla Emy.
Título: Reactive oxygen species generation mediated by NADPH oxidase and PI3K/Akt pathways contribute to invasion of Streptococcus agalactiae in human endothelial cells
Fonte: Mem. Inst. Oswaldo Cruz;113(6):e140421, 2018. graf.
Idioma: en.
Projeto: Universidade do Estado do Rio de Janeiro.
Resumo: BACKGROUND Streptococcus agalactiae can causes sepsis, pneumonia, and meningitis in neonates, the elderly, and immunocompromised patients. Although the virulence properties of S. agalactiae have been partially elucidated, the molecular mechanisms related to reactive oxygen species (ROS) generation in infected human endothelial cells need further investigation. OBJECTIVES This study aimed to evaluate the influence of oxidative stress in human umbilical vein endothelial cells (HUVECs) during S. agalactiae infection. METHODS ROS production during S. agalactiae-HUVEC infection was detected using the probe CM-H2DCFDA. Microfilaments labelled with phalloidin-FITC and p47phox-Alexa 546 conjugated were analysed by immunofluorescence. mRNA levels of p47phox (NADPH oxidase subunit) were assessed using Real Time qRT-PCR. The adherence and intracellular viability of S. agalactiae in HUVECs with or without pre-treatment of DPI, apocynin (NADPH oxidase inhibitors), and LY294002 (PI3K inhibitor) were evaluated by penicillin/gentamicin exclusion. Phosphorylation of p47phox and Akt activation by S. agalactiae were evaluated by immunoblotting analysis. FINDINGS Data showed increased ROS production 15 min after HUVEC infection. Real-Time qRT-PCR and western blotting performed in HUVEC infected with S. agalactiae detected alterations in mRNA levels and activation of p47phox. Pre-treatment of endothelial cells with NADPH oxidase (DPI and apocynin) and PI3K/Akt pathway (LY294002) inhibitors reduced ROS production, bacterial intracellular viability, and generation of actin stress fibres in HUVECs infected with S. agalactiae. CONCLUSIONS ROS generation via the NADPH oxidase pathway contributes to invasion of S. agalactiae in human endothelial cells accompanied by cytoskeletal reorganisation through the PI3K/Akt pathway, which provides novel evidence for the involvement of oxidative stress in S. agalactiae pathogenesis.
Responsável: BR1.1 - BIREME


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Id: biblio-1008047
Autor: Benites, Julio; Asunción-Alvarez, Holbert D; Ybañez-Julca, Roberto O; Ganoza-Yupanqui, Mayar L; Jacinto-Fernandez, Juan J; Reyes-De la Vega, Junior B; Zavaleta-Cruz, Hair J; Pinedo-Alcántara, Adela N; Lavado-Fonseca, Cristian M; Medina-Mejia, Carlos A; Catalan, Marcelo; Morales, Bernardo; Albuquerque, Ricardo D.D.G. de; Rocha, Leandro; Martinez, José L.
Título: Chemical composition by HPLC-ESI-QTOF-MS/MS: Estrogenic and antioxidant effects of Mangifera indica L. cv. "Kent" leave extracts on ovariectomized rats / Composición química por HPLC-ESI-QTOF-MS/MS: efectos estrogénicos y antioxidantes de extractos de Mangifera indica L. cv. "Kent" en ratas ovariectomizadas
Fonte: Bol. latinoam. Caribe plantas med. aromát;18(3):336-346, mayo 2019. tab, ilus.
Idioma: en.
Projeto: Desarrollo Científico, Tecnológico y de Innovación Tecnológica; . Consejo Nacional de Ciencia Tecnología e Innovación Tecnológica (Perú).
Resumo: The chemical composition of Mangifera indica L. cv. "Kent" leaves was determined by HPLC-ESI-QTOF-MS/MS. Polyphenolic compounds characterized as benzophenone derivatives were the main components found in extracts (1, maclurin 3-C-(2-O-galloyl)-D- glucoside isomer; 2, maclurin 3-C---D-glucoside; 3, iriflophenone 3-C---D-glucoside; 5, maclurin 3-C-(2,3-di-O-galloyl)---D-glucoside; 6, iriflophenone 3-C-(2-O-galloyl)---D-glucoside; 7, methyl-iriflophenone 3-C-(2,6-di-O-galloyl)---D-glucoside) and xanthones (4, mangiferin and 8, 6-O-galloyl-mangiferin). The estrogenic and antioxidant effects of aqueous extracts from Mangifera indica L. cv. "Kent" leaves on ovariectomized rats were determined by uterotrophic assay and malondialdehyde (MDA) levels in erythrocytes, bone, liver, and stomach. We conclude that the polyphenolic compounds from extracts act as exogenous antioxidant agents against oxidative damage in ovariectomized rats.

La composición química de las hojas de Mangifera indica L. cv. "Kent" se determinó por HPLC-ESI-QTOF-MS/MS. Compuestos polifenólicos caracterizados como derivados de benzofenona fueron los componentes principales encontrados en los extractos (1, isómero de la maclurina 3-C-(2-O-galoyil)-D-glucósido; 2, maclurina 3-C-ß-D-glucósido; 3, iriflofenona 3-C-ß-D-glucósido; 5, maclurina 3-C-(2,3-di-O-galloíl)-ß-D-glucósido; 6, iriflofenona 3-C-(2-O-galloil)-ß-D-glucósido; 7, metil-iriflofenona 3-C-(2,6-di-O- galloyl)-ß-D-glucósido) y xantonas (4, mangiferina y 8, 6-O-galoyil-mangiferina). Los efectos estrogénicos y antioxidantes de los extractos acuosos de hojas de Mangifera indica L. cv. "Kent" en ratas ovariectomizadas se determinaron mediante ensayo uterotrófico y la medición de los niveles de malondialdehído (MDA) en eritrocitos, huesos, hígado y estómago. Concluimos que los compuestos polifenólicos de los extractos actúan como agentes antioxidantes exógenos contra el daño oxidativo en ratas ovariectomizadas.
Responsável: CL1.1 - Biblioteca Central


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Id: lil-604422
Autor: Gomes, Tâmara Kelly de Castro; Oliveira, Suzana Lima de; Ataíde, Terezinha da Rocha; Trindade Filho, Euclides Maurício.
Título: O papel da dieta cetogênica no estresse oxidativo presente na epilepsia experimental / The role of the ketogenic diet on oxidative stress present in experimental epilepsy
Fonte: J. epilepsy clin. neurophysiol;17(2):54-64, 2011.
Idioma: pt.
Resumo: INTRODUÇÃO: A epilepsia é um dos transtornos neurológicos mais comuns, sendo definido como uma condição de crises recorrentes espontâneas. Existe uma importante relação entre radicais livres e enzimas antioxidantes no fenômeno epiléptico, e as espécies reativas de oxigênio (EROs) têm sido implicadas na neurodegeneração induzida pelas crises. OBJETIVO: A presente revisão teve como objetivo investigar a relação existente entre o estresse oxidativo e a epilepsia, destacando o efeito da dieta cetogênica sob condições experimentais. MATERIAL E MÉTODOS: Procedeu-se a pesquisa em artigos científicos publicados nos Bancos de Dados Medline, PubMed, Periódicos CAPES, ScienceDirect e Scielo. As palavras-chave selecionadas para a pesquisa incluíram epilepsia, status epilepticus, pilocarpina, estresse oxidativo, espécies reativas de oxigênio, disfunção mitocondrial. RESULTADOS E DISCUSSÃO: Terapia dietética tem sido utilizada, como é o caso da dieta cetogênica (DC), a qual é rica em lipídeos e pobre em carboidratos e utilizada por mais de oito décadas para o tratamento de epilepsia refratária, principalmente em crianças. A DC modula a bionergética mitocondrial, diminui a formação de EROs, aumenta a capacidade antioxidante celular e ainda, previne alterações do DNA mitocondrial. CONCLUSÃO: Evidências de atuação da DC na disfunção mitocondrial, como ocorre na epilepsia, são muitas e demonstram claramente efeitos benéficos dessa terapêutica.

INTRODUCTION: Epilepsy is a neurological disorder more common, being defined as a condition of spontaneous recurrent seizures. An important relationship exists between free radicals and antioxidant enzymes in epileptic phenomena and reactive oxygen species (ROS) have been implicated in neurodegeneration induced by crises. AIM: This review aimed to investigate the relationship between oxidative stress and epilepsy, highlighting the effect of the ketogenic diet under experimental conditions. METHODS: There has been research papers published in the databases Medline, PubMed, CAPES journals, ScienceDirect and Scielo. The keywords selected for the study included epilepsy, status epilepticus, pilocarpine, oxidative stress, reactive oxygen species, mitochondrial dysfunction. RESULTS AND DISCUSSION: Dietary therapy has been used, such as the ketogenic diet (KD), which is rich in fat and low in carbohydrates and used by more than eight decades for the treatment of refractory epilepsy, especially in children. The KD modulates mitochondrial bioenergetic, decreases the formation of ROS, increases the antioxidant capacity and also prevents changes in mitochondrial DNA. CONCLUSION: Evidence of activity of KD in mitochondrial dysfunction, as epilepsy, are many and clearly demonstrate the beneficial effects of the therapy.
Responsável: BR16.1 - Biblioteca de Ciências da Saúde


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Toniolli, Ricardo
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Id: biblio-895447
Autor: Souza, Wildelfrancys L; Moraes, Elenice A; Toniolli, Ricardo.
Título: Adição de antioxidantes ao sêmen de carneiros e seus efeitos após a descongelação / Addition of antioxidants in ram semen and the effects after thawing
Fonte: Pesqui. vet. bras = Braz. j. vet. res;37(5):471-478, maio 2017. tab, graf.
Idioma: pt.
Projeto: Centro de Pesquisa em Suínos, Espécies Nativas e Silvestre; . Pró Reitoria de Pesquisa e Pós-Graduação da UNIVASF.
Resumo: Objetivou-se avaliar o efeito da adição dos antioxidantes ácido ascórbico, melatonina e Trolox C, associados ao sêmen diluído de carneiros sobre o estresse oxidativo e o potencial fecundante após criopreservação. Foram coletados 10 ejaculados de 3 carneiros (n=30) e diluídos em Tris-Gema de ovo até a concentração final de 200x106 sptz/mL e, mantidos em banho maria a 32°C. Os antioxidantes foram adicionados da seguinte forma: controle (sem adição de antioxidantes); 100µM de melatonina (MEL) + 0,05% de ácido ascórbico (AA); 100µM de MEL + 90µL de Trolox C (TRO); 90µL de TRO + 0,05% de AA; e 100µM de MEL + 0,05%AA + 90µL de TRO. Depois, o sêmen foi resfriado em câmara fria a 5°C por duas horas, após esse período, envasado e lacrado em palhetas de 0,5mL, e então acondicionado sob vapor de nitrogênio liquido (N2L), a 8cm da lâmina líquida por 15 minutos, e depois imersos no N2L. As amostras foram analisadas quanto à motilidade espermática, integridade da membrana plasmática e da membrana acrossomal, atividade mitocondrial, teste de ligação e a quantificação do estresse oxidativo. As variáveis foram submetidas à análise de variância e medias comparadas pelo teste de Tukey a 5% de probabilidade. A motilidade (total e progressiva) foi maior (P<0,05) quando adicionado à associação MEL+AA+TRO (67% e 49,89%), MEL+AA (64,37% e 45,61%) e MEL+TRO (61,65% e 41,15%) comparado ao tratamento controle (55,52% e 36,54%) e TRO+AA (57,07% e 38,40%). A adição de MEL+AA+TRO ao sêmen diluído manteve (P<0,05) a integridade da membrana plasmática (30,75%) e acrossomal (84,53%) dos espermatozoides quando comparado ao tratamento controle (15,60 e 68,16%, respectivamente), além de ter promovido maior (P<0,05) atividade mitocondrial (96,43%) quando comparado aos demais tratamentos. O número de espermatozoides que apresentaram à capacidade de ligação a membrana perivitelina da gema de ovo foi maior (P<0,05) no sêmen tratado com as diferentes associações de antioxidante quando comparado ao controle, sendo a associação MEL+AA+TRO (178,36%) superior (P<0,05) aos demais tratamentos. Não houve diferença (P>0,05) entre os tratamentos quanto a quantidade de espécies reativas ao ácido tiobarbitúrico produzidos. Conclui-se que a adição de MEL+AA+TRO ao sêmen diluído de carneiros, nas doses avaliadas, melhora a qualidade espermática após descongelação.(AU)

Aimed to evaluate the effect of adding antioxidants as ascorbic acid, melatonin and Trolox C to diluted semen of ram with oxidative stress to potenciate fertilization after cryopreservation. Ten samples collected were diluted in Tris-egg yolk to a final concentration of 200x106 sperm/mL and kept in a water bath at 32°C. Antioxidants were added as follows: 100µM melatonin (MEL) +.05% ascorbic acid (AA); 100µM of MEL + 90µL of Trolox C (TRO); 90µL of TRO + 0.05% AA; and 100µM of MEL0.05% AA + 90µL of TRO. Semen was cooled in a cold chamber at 5°C for two hours and packaged, sealed in 0.5mL straws, packaged under liquid nitrogen vapor (N2L), 8cm of water depth for 15 minutes, and then immersed in N2L. Samples were assayed for motility, integrity of the plasma membrane and acrosomal membrane, mitochondrial activity, binding assay and oxidative stress spermatozoa. The variables were analyzed by ANOVA and means compared by Tukey test (P<0.05). Percentage of total and progressive motility was higher for sperm treated with MEL+AA+TRO (67% and 49.89%), MEL+AA (64.37% and 45.61%) and MEL+TRO (61.65% and 41.15%) compared with the other treatments (P<0.05). The integrity of the plasma membrane and acrosome was higher for all semen treated with antioxidant associations compared with control (P<0.05). Mitochondrial activity was higher in sperm treated with MEL+AA+TRO compared all treatments (P<0.05). The number of sperm binding to perivitelline membrane was higher for semen treated with antioxidant associations compared with control; also sperm treated with MEL+AA+TRO demonstrated higher effect of all (P<0.05). No difference was observed between the treatments by oxidative stress sperm (P>0.05). The addition of melatonin, ascorbic acid and Trolox C in diluted semen of ram improves sperm quality after thawing.(AU)
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-998288
Autor: Olarte S, Maricela; Sánchez R, Sergio Hugo; Aréchiga F, Carlos Fernando; Bañuelos V, Rómulo; Ramírez A, Elena Donají; López L, Argelia.
Título: Daño y respuesta celular en piel por exposición prolongada a radiación UV / Cell response and skin damage by prolonged exposure to UV radiation
Fonte: Rev. ANACEM (Impresa);9(1):44-51, jun. 2015. ilus, tab.
Idioma: es.
Resumo: La piel es uno de los órganos importantes que con mayor frecuencia sufre estrés oxidativo por la radiación ultravioleta (UV), proveniente de la radiación solar, por su longitud de onda se clasifica en: UVA, UVB, y UVC. La UVB es la que mayor daño biológico produce en la piel causando estrés oxidativo, el cual se da por una excesiva producción de Especies Reactivas del Oxígeno (ERO's) y su corrección está mediado por diferentes mecanismos enzimáticos endógenos como: Superóxido Dismutasa (SOD), Glutatión Peroxidasa (GPX), Catalasa y sistemas exógenos no enzimáticos como la vitamina E y la vitamina C. Los ERO's causan daños como oxidación de proteínas, ADN y lípidos, dando como consecuencia múltiples fenómenos inflamatorios, cáncer, inmunosupresión, daños celulares y estructurales. Para la realización de este artículo se hizo una revisión sistemática en bases de datos bibliográficas (PubMed/MEDLINE, Science) y a través de internet en revistas públicas, se definieron criterios de inclusión y exclusión (afecciones de la piel provocadas por la exposición de luz UV, ERO´s, antioxidantes) y un conjunto de variables para analizar las características de los artículos seleccionados como Respuesta celular en piel producida por exposiciones a la luz solar. Es importante estar actualizado en estos mecanismos, por el aumento del número de personas que se exponen a diario a la luz solar

The skin is one of the most important organs can undergo oxidative stress by ultraviolet radiation (UV), this come from solar ultraviolet radiation and is classified by its wavelength: UVA, UVB, and UVC. It is UV-B that causes greater biological damage to the skin causing oxidative stress, which occurs by excessive production of reactive oxygen species (ROS's) and its correction is mediated by different mechanisms such as endogenous enzyme; Superoxidedismutase (SOD), glutathione peroxidase (GPX), catalase and exogenous systems non-enzymatic include vitamin E, vitamin C. The ROS's cause oxidative damage to proteins, DNA, and lipids, giving due multiple inflammatory phenomena, cancer, immunosuppression and structural and damage cells. We performed a systematic review in bibliographic databases (PubMed / MEDLINE, Science) and through internet in public journals, Inclusion and exclusion criteria (skin disorder caused by exposure to UV light, ROS's, antioxidants) and a set of variables were defined to analyze the characteristics of selected items as skin cell response by exposure to sunlight. It is Important to be updated on these mechanisms by increasing the number of people who are exposed daily to sunlight
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-975701
Autor: Bin-Jaliah, Ismaeel; Haffor, Al-Said.
Título: Ultrastructural morphological alterations during hyperoxia exposure in relation to glutathione peroxidase activity and free radicals productions in the mitochondria of the cortical brain / Alteraciones morfológicas ultraestructurales durante la exposición a la hiperoxia en relación con la actividad de la glutatión peroxidasa y la producción de radicales libres en las mitocondrias de la corteza cerebral
Fonte: Int. j. morphol;36(4):1310-1315, Dec. 2018. tab, graf.
Idioma: en.
Resumo: Exposure to normobaric hyperoxia (NH) is known to increase the production of reactive oxygen species (ROS) by mitochondria. The present study was designed to examine mitochondrial ultrastructure morphological changes in the cortical brainin relation to glutathione peroxidase (GPX) activity and free radicals (FR) productions in brain tissue during hyperoxia exposure. The experimental groups were exposed to NH for 24 and 48 h continuously. Following the exposure periods, animals were sacrificed and cortical tissues were divided randomly into two parts; the first part was processed for the ultrastructural examination and the second was homogenized for GPX and FR determinations. Analysis of variance (ANOVA) showed that the main effects of O2 exposure periods were significant (p<0.05) for GPX and FR. Pair-wise means comparisons showed that NH elevated the average (+SE) GPX activity significantly (p<0.05) from the baseline control value of 5670.99+556.34 to13748.42+283.04 and 15134.19+1529.26 U/L with increasing length of NH exposure period from 24 to 48 h, respectively. Similarly, FR production was increased significantly (p<0.05) to 169.73+10.31 and 185.33+21.87, above baseline control of 105.27+5.25 Unit. Ultrastructure examination showed that O2 breathing for 48 h resulted in giant and swelled mitochondria associated with diluted inner membrane and damaged cristae. These mitochondria pathological alterations were associated with damages of myelin, axonal and cellular organelles. Normobaric-hyperoxia inducts mitochondria oxidative stress (MOS) and the subsequent rise of ROS causes variety of ultrastructure morphological pathological alterations in the organelles of cortical brain cells.

Se sabe que la exposición a la hiperoxia normobárica (HN) aumenta la producción de especies reactivas de oxígeno (ERO) por parte de las mitocondrias. El estudio se diseñó para examinar los cambios morfológicos de la ultraestructura mitocondrial en la corteza cerebral con la actividad de la glutatión peroxidasa (GPX) y la producción de radicales libres (RL) en el tejido cerebral durante la exposición a la hiperoxia. Los grupos experimentales fueron expuestos a HN durante 24 y 48 h continuamente. Tras los períodos de exposición, los animales se sacrificaron y los tejidos corticales se dividieron aleatoriamente en dos partes; la primera parte se procesó para el examen ultraestructural y la segunda se homogeneizó para las determinaciones de GPX y RL. El análisis de varianza (ANOVA) mostró que los efectos principales de los períodos de exposición al O2 fueron significativos (p <0,05) para GPX y RL. Las comparaciones de medias por pares mostraron que la HN elevó la actividad promedio de GPX (+ SE) significativamente (p <0,05) desde el valor de control de línea base de 5670,99 + 556,34 a 13748,42 + 283,04 y 15134,19 + 1529,26 U / L con una mayor duración del período de exposición a HN de 24 a 48 h, respectivamente. De manera similar, la producción de RL se incrementó significativamente (p <0,05) a 169,73 + 10,31 y 185,33 + 21,87, por encima del control de referencia de 105,27 + 5,25 unidades. El examen de la ultraestructura mostró que la respiración de O2 durante 48 h dio lugar a mitocondrias gigantes e hinchadas asociadas con la membrana interna diluida y las crestas dañadas. Estas alteraciones patológicas de las mitocondrias se asociaron con daños de mielina, axones y organelos celulares. La hiperoxia normobárica induce el estrés oxidativo mitocondrial (MOS) y el posterior aumento de las ERO provoca una variedad de alteraciones patológicas y morfológicas en los organelos de las células cerebrales corticales.
Responsável: CL1.1 - Biblioteca Central



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