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From yellow to pink using a fluorimetric and colorimetric pyrene derivative and mercury (II) ions

Pinheiro, Daniela; Castro, Catherine S. de; Melo, J. Sérgio Seixas de; Oliveira, Elisabete; Nuñez, Cristina; Fernández-Lodeiro, Adrián; Capelo, José Luis; Lodeiro, Carlos
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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A new simple and multifunctional fluorescent probe based on pyrene linked through an imine bond to a hydroxyphenol unit was synthesised, fully characterized and investigated in solution. Additionally, its behaviour in the presence of several ions (H+, Zn2+, Cd2+, Cu2+, Ni2+, Pb2+, Fe2+, Hg2+ and Al3+) was investigated in CH2Cl2. It was found that the absorption spectra of probe 1 shows no differences for all ions titrations except in the presence of H+ and Hg2+ where a new longer wavelength band becomes visible (inducing a colour change from yellow to orange and pink, respectively). In the emission, a blue-shift and an enhancement of the fluorescence of the probe for all metal ions was observed with the exception of Al3+ where no detectable changes could be observed. The probe was found to be selective for Hg2+ ion at low concentrations (till one equivalent).; 1st International Caparica Conference on Chromogenic and Emissive Materials

Ensaio cometa em microalgas marinhas: danos no DNA de Dunaliella tertiolecta Butcher 1959 causados pela exposição à 4-nitroquinolina-N-óxido e ao benzo [a] pireno; Comet assay in marine microalgae: DNA damage in Dunaliella tertiolecta Butcher 1959 caused by exposure to 4-nitroquinoline-N-oxide and benzo[a]pyrene

Ussami, Keyi Ando
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/10/2007 PT
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Dunaliella tertiolecta, uma alga verde fitoplanctônica de ampla distribuição no ambiente marinho, foi escolhida como organismo teste para estudar a possibilidade de ser utilizada no ensaio cometa, um teste de detecção de danos no DNA em células individualizadas muito utilizado na ecotoxicologia. Essas algas foram facilmente lisadas pela solução de lise alcalina iônica, seus cometas foram corados eficientemente pelo brometo de etídio e pela prata, e a análise por índice de danos apresentou boa correlação com momento de cauda, comprimento de cauda e porcentagem de DNA na cauda. As algas foram expostas a concentrações crescentes de 4-nitroquinolina-N-óxido (4NQO) e benzo[a]pireno (BAP) por 1, 2 e 4 h no escuro. Após somente 1 h de exposição, observou-se um aumento significativo de danos no DNA das algas expostas a 0,25 µM de 4NQO, demonstrando a sensibilidade das mesmas em relação a células de animais. Os dados obtidos da exposição ao BAP não foram consistentes e necessitam de verificação. A metabolização de BAP em compostos tóxicos pelas algas e o efeito das condições de luminosidade antes e durante as exposições são discutidos. Os resultados indicam que D. tertiolecta pode ser utilizada em laboratório para avaliação de genotoxicidade na água através do ensaio cometa.; D. tertiolecta...

Estudo sobre efeitos do naftaleno e benzo(a) pireno em Trachinotus carolinus (Perciformes, Carangidae) utilizando biomarcadores citogenotóxicos, histopatológicos e bioquímicos; Study of the effects of naphthalene and benzo(a) pyrene in Trachinotus carolinus (Perciformes, Carangidae) using citogenotoxic, histopahological and biochemical biomarkers.

Santos, Thaís da Cruz Alves dos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/12/2009 PT
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A exposição dos peixes a poluentes provoca danos nos organismos que podem ser identificados precocemente através de respostas biológicas. O presente estudo visou avaliar os efeitos do naftaleno e benzo(a)pireno em pampos da espécie Trachinotus carolinus. Foram avaliados os efeitos citogenotóxicos, histopatológicos e bioquímicos após exposições às concentrações de 0,9 M; 2,7 M e 8,1 M de NAP e BAP por períodos de 12, 24, 48 e 96 horas. O NAP causa quebra no DNA de eritrócitos de pampos em concentrações de 8,1 M e a partir de 12 horas de exposição. O BAP revelou ser genotóxico a partir da menor concentração e de 24 horas. A mutagenicidade de ambos os poluentes, avaliada através da indução de formação de micronúcleos e anormalidades nucleares eritrocitárias, também ocorre a partir de curtos períodos de exposição e freqüências de MN e ANE estão relacionadas com a duração da exposição. O período de exposição aos HPAs foi determinante na intensidade e severidade das lesões observadas nos tecidos dos peixes. A especificidade de CYP1A, observada segundo análise imunohistoquímica, ocorreu de maneira dose-dependente e evidenciada principalmente nos maiores períodos experimentais. Os poluentes orgânicos...

Efeitos tóxicos de benzo(a)pireno sobre a macroalga vermelha Gracilaria birdiae; Toxic Effects of Benzo(a)pyrene on the Red Macroalga Gracilaria birdiae

Almeida, João Vasconcellos de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 09/04/2010 PT
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Os organismos chamados de algas apresentam uma grande diversidade de espécies e ocupam uma grande variedade de nichos ecológicos. Fundamentais para a manutenção das condições que permitem a vida no planeta, inclusive porque constituem a base de cadeias tróficas de ecossistemas aquáticos, as algas vêm sofrendo com o descarte contínuo de resíduos resultantes das mais variadas atividades humanas. Por outro lado, as algas, ao serem expostas aos poluentes, podem indicar a presença dos mesmos em seus habitats por meio de seus biomarcadores. Neste sentido, este trabalho preocupou-se em caracterizar as bases moleculares da toxicidade do hidrocarboneto policíclico aromático (HPA) benzo(a)pireno (BaP), presente no petróleo cru e derivado da combustão parcial de matéria orgânica, sobre a macroalga vermelha Gracilaria birdiae, uma Rhodophyta marinha nativa. Para avaliar a agressividade do poluente, a alga foi exposta a diferentes concentrações do HPA em água do mar, tanto em situações de exposição aguda (24 e 96h) quanto crônica (7 e 15 dias). Após estes períodos de exposição, alguns biomarcadores bioquímicos e fisiológicos da alga tiveram seus comportamentos analisados. Foram eles: taxas de crescimento (TC); duas defesas antioxidantes: os níveis do tripeptídeo de baixo peso molecular glutationa (GSH) e a atividade da enzima superóxido dismutase (SOD); os níveis do dímero de glutationa GSSG; a fotossíntese da macroalga; e seu aspecto de pigmentação geral. Foi possível observar que BaP é tóxico para a macroalga G. birdiae. Aumentos da concentração do HPA nos meios de cultura das algas provocaram menores TC. A partir destes dados de TC foi possível determinar uma curva de inibição do crescimento da alga e a 7 respectiva IC50 de BaP para um período de exposição de 15 dias...

Biochemical biomarkers in Oreochromis niloticus exposed to mixtures of benzo[a]pyrene and diazinon.

Tridico, Camila Pereira; Ferreira Rodrigues, Aline Cristina; Nogueira, Lilian; da Silva, Daniele Caetano; Moreira, Altair Benedito; de Almeida, Eduardo Alves
Fonte: Academic Press Inc. Elsevier B.V. Publicador: Academic Press Inc. Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 858-863
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 06/03873-1; Biochemical biomarkers (the activities of acetylcholinesterase, 7-ethoxyresorufin-O-deetilase, carboxylesterase, catalase, glutathione peroxidase and glutathione S-transferase) were evaluated in Nile tilapia (Oreochromis niloticus) that had been exposed to benzo[a]pyrene (BaP) and the organophosphate pesticide diazinon (DZ), at 0.5 mg/L. The animals were pre-exposed to BaP for three days, and DZ was then added to both non-exposed and pre-exposed groups, being exposed for 2 and 7 additional days. The level of BaP was also measured in the bile. BaP caused the induction of phase I and II enzymes, and DZ caused carboxylesterase inhibition in gills but not in liver. AChE activity was unchanged. No significant modulation was observed in antioxidant enzymes. When in combination with BaP, DZ caused a significant decrease of EROD and GST induction. Levels of BaP in the bile were also increased in fish exposed to BaP combined with DZ, indicating an interference of DZ in responses activated by BaP. (C) 2010 Elsevier B.V. All rights reserved.

Simultaneous Determination of Phenanthrene and Benzo(a)pyrene in Water Samples by Synchronous Fluorescence Spectroscopy

Sposito, Thiago Luiz; Bisinoti, Marcia Cristina; Moreira, Altair Benedito
Fonte: Taylor & Francis Inc Publicador: Taylor & Francis Inc
Tipo: Artigo de Revista Científica Formato: 2271-2279
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 07/50461-3; Processo FAPESP: 05/51242-8; A simple and sensitive method was developed to simultaneously determine phenanthrene and benzo(a) pyrene in water samples using synchronous fluorescence spectroscopy with a 56-nm Delta lambda. The method was used to simultaneously determine both compounds in samples of spiked surface water. Analytical recoveries were 96.9-101.1% for phenanthrene and 95.8-103.5% for benzo(a) pyrene. Analytical results were checked for precision with 15 measurements for each compound. Relative standard deviations were 1.9% for phenanthrene and 2.9% for benzo(a) pyrene, which shows that the proposed method is quite precise.

Effect of mixture of diazinon and benzo[a]pyrene in Glutathione S-transferase of Nile tilapia

da Silva, Daniele Caetano; Trídico, Camila Pereira; Serrano, Lenard; Almeida, Eduardo A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 9-15
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 2006/03873-1; Currently, with the growing contamination of aquatic ecosystems, many compounds, such as pesticides and hydrocarbons, are improperly released into rivers and lakes. Studies about the exposure of single pollutants causing biochemical variations are abundant in the literature. However, there are few studies focused on the biological effects of complex mixtures. The aim of this investigation was to evaluate whether mixture diazinon and benzo[a]pyrene can affect the biochemical activities of classic biomarkers such as acetylcholinesterase (AChE), carboxylesterase (CbE), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in Nile tilapia and compare the effects on enzymatic systems of the exposure to a mixture of compounds and the effects observed when they are exposed separately. We measured the activity of enzymes in gills and liver of Nile Tilapia (Oreochromis niloticus) after 2 and 7 days of exposure to Diazinon (0.5 mg/L) and benzo[a]pyrene (1.0 mg/L) individually and in mixture. The results showed that in the mixture group after 7 days of exposure, the benzo[a]pyrene increased the inhibitory action of Diazinon in GST enzyme activity...

Avaliação da polaridade superficial de nailons por espectroscopia de fluorescencia; Pyrene fluorescence spectroscopy applied to studies of nylons polarity sites

Leonardo Dela Coleta Bald
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/08/2004 PT
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Este trabalho trata da determinação da polaridade superficial de diferentes tipos de náilons, previamente caracterizados por métodos térmicos de análise (DSC e TGA), infraverrnelho (FT-IR) e difratometria de raios-X (XRD): -6, -6,6, -6,10, -6,12 e -11. O náilon-6,9, incluído neste trabalho, foi caracterizado apenas por FT-IR e XRD. Para tanto, empregou-se urna metodologia baseada nas propriedades de fluorescência do pireno, uma molécula cuja estrutura vibrônica em particular é fortemente dependente da polaridade do meio. Mostrou-se que ambos intensidades vibrônicas e decaimentos de fluorescência dependem da polaridade superficial dos náilons estudados, e que esses polímeros podem ser classificados em termos de polaridade de acordo com sua classe, AB (náilons -6 e -11) ou AABB (náilons-6,6, -6,9, -6,10 e -6,12). Na qualidade de sensor de polaridade, o pireno mostra que sistemas mais polares apresentam menor tempo de decaimento e maior valor da relação II/IIII (valor obtido a partir do espectro de fluorescência do pireno adsorvido na matriz polimérica). Os náilons podem então ser comparados a solventes comuns, utilizando-se os valores da escala de polaridade py do pireno. Este mostrou ser uma sonda de curto alcance: caso o polímero possua monômero cujo comprimento linear ultrapasse 7Å...

Sensing hydration and behavior of pyrene in POPC and POPC/cholesterol bilayers: A molecular dynamics study

Loura, Luís M. S.; Martins do Canto, António Manuel Teixeira; Martins, Jorge
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
POR
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Molecular dynamics (MD) simulations of bilayers of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) with varying amounts of cholesterol (0, 5, 20, and 40 mol%) were carried out in the absence and presence of inserted pyrene molecules. Both fluorophore and bilayer parameters were computed, for characterization of probe location and dynamics, as well as its effects on the host bilayer. In agreement with previous studies in fluid disordered bilayers, pyrene prefers to be located in the hydrophobic acyl chain region of POPC bilayers, close to the glycerol group of lipid molecules and causes ordering of the lipid acyl chains. However, incorporation of pyrene in binary POPC/cholesterol bilayers decreases the acyl chain order parameter (especially near the end of the chains), opposing the ordering effect of cholesterol. These effects are modest and mainly felt locally. Significantly, as the bilayer is enriched with cholesterol, the relative position of pyrene and the POPC carbonyl and phosphocholine groups is invariant, and the local water density around the probe decreases. This work clarifies and supports the cautious use of pyrene Ham effect to effectively measure equivalent polarity in lipid bilayers. Within the time scale of the MD simulations...

Selectivity and efficiency of pyrene attachment to alkanes induced by broadband X-rays

BROWN,GERALD O.; GUARDALA,NOEL A.; PRICE,JACK L.; WEISS,RICHARD G.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2003 EN
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Bombardment of pyrene-doped n-heneicosane (C21H44) in its orthorhombic solid phase with <1.3> MeV broadband X-rays results in the formation of both mono- and di-heneicosylpyrenes, whereas the same dose in liquid cyclohexane yields only monosubstituted pyrene. In both cases, the reaction efficiency decreases as pyrene concentration is increased from 10-5 to 10-2 M. Qualitatively, the overall attachment efficiency is higher in orthorhombic n-heneicosane than in liquid cyclohexane, but the selectivity of attachment is greater in cyclohexane. Differences between these results and those from irradiations of the same samples with eV range photons are discussed.

Usefulness of argyrophilic nucleolar organizer regions in detection of lung cells alterations after benzo[a]pyrene instillation

Silva,Baldomero Antonio Kato da; Silva,Iandara Schettert; Pereira,Daniel Martins; Aydos,Ricardo Dutra; Carvalho,Paulo de Tarso Camillo de
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2006 EN
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PURPOSE: To verify the relationship between AgNOR expression and lung tissues changes of Wistar rats after pulmonary instillation of benzo[a]pyrene (B[a]P). METHODS: Male Rattus norvegicus albinus,Wistar lineage were given a single intrapulmonary instillation of B[a]P at doses of 10 and 20 mg/kg in a volume of approximately 0,3 ml. After 7 and 21 days the rats were killed and the lung slices submitted to a histological technique of AgNOR. AgNOR dots were quantified and the result analyzed by statistical tests; p <= 0,05 was considered significant. RESULTS: The mean values of AgNOR dots for the experimental groups 10/7 (1,51±0,86) and 10/21 (1,84±0,13) were statistically different (p = 0,009). Among the groups 20/7 (1,63±0,11) and 20/21 (2,48±0,28) was observed statistically significant difference (p = 0,003). CONCLUSION: The AgNOR technique can be useful in identification of cells changes induced by B[a]P.

Sistematic study of benzo[a]pyrene in coffee samples

Badolato,Elza S. G.; Martins,Maristela S.; Aued-Pimentel,Sabria; Alaburda,Janete; Kumagai,Edna E.; Baptista,Gisleine G.; Rosenthal,Amaury
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2006 EN
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A method for extracting and quantifying benzo[a]pyrene (B[a]P) was evaluated and improved for samples of green and roasted ground Arabica (Coffea arabica) and Conillon (Coffea canephora) Brazilian coffees. The influence of the roasting process in B[a]P formation was considered too. These samples were extracted with acetone, followed by saponification and cyclohexane extraction. The extracts were cleaned by chromatography on a silica-gel. The quantification was done by HPLC with reversed-phase and fluorescence detection under isocratic conditions. The detection and quantification limits were 0.03 µg kg-1 and 0.10 µg kg-1, respectively. The recovery ranged from 76 to 116% for concentrations between 1.00 and 3.00 µg kg-1. The values obtained for B[a]P concentrations were from 0.47 to 12.5 µg kg-1 for samples of ground roasted coffee. B[a]P was absent in the green coffee samples. The control of the roasting parameters is fundamental for obtaining a good quality product.

Individual sensitivity to cytogenetic effects of benzo[alpha]pyrene in cultured human lymphocytes: influence of glutathione S-transferase M1 genotype

Güven,Gülgün S.; Güven,Mehmet; Onaran,Ilhan; Ulutin,Turgut; Hacihanefioglu,Seniha
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2006 EN
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Sister chromatid exchange (SCE) and chromosome aberrations (CA) in peripheral lymphocytes has been widely used in assessing exposure to mutagens and carcinogens. One of the extensively studied genotoxins is benzo[alpha]pyrene (BaP). We studied the ability of BaP to induce SCE and CA in 16 glutathione S-transferase M1 (GSTM1)-positive and 15 GSTM1-null individuals by analyzing 72-h whole-blood lymphocyte cultures, either BaP-untreated (controls) or treated with 5 µM of BaP for 24 or 48 h. There was no differences in the level of BaP-induced chromosomal aberrations between GSTM1-positive or null individuals when the cells were BaP-exposed for 24 h (0.083 ± 0.059 vs. 0.090 ± 0.058) or 48 h (0.092 ± 0.057 vs. 0.096 ± 0.050. The frequency of SCE in controls was GSTM1-positive = 2.96 ± 0.35 and GSTM1-null = 3.23 ± 0.56 while that for BaP-treated lymphocytes was GSTM1-positive = 5.56 ± 0.83 and GSTM1-null = 6.09 ± 1.11 and were not statistically significant. The rates of BaP-induced in vitro chromatid and chromosome-type gaps and breaks were similar in all groups, although GSTM1-null genotype chromatid-type breaks were more frequent (0.064 ± 0.039 per metaphase) than chromosome-type breaks (0.032 ± 0.027 per metaphase) after 48 h treatment with BaP (p < 0.001). These findings suggest that BaP-induced in vitro SCE and CA are not influenced by the GSTM1 genotype.

Monitoring the effect of pyrene on the germination and radial growth of the wild and mutant strains of Rhizopus arrhizus UCP402

Shiosaki,Ricardo Kenji; Albuquerque,Clarissa Daisy da Costa; Okada,Kaoru; Fukushima,Kazutaka; Campos-Takaki,Galba Maria
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
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The physiological mutant of Rhizopus arrhizus was obtained in the pyrene resistance gradient test. Comparative studies were carried out about the behavior of the germination process and the radial growth of the mutant and wild strains of R. arrhizus UCP 402. Sabouraud Sucrose and Yeast Malt Broth cultures containing pyrene (10 mg/L) induced the germination process of the sporangiospores of the wild and mutant strains of R. arrhizus. The radial growth of the strains was inversely proportional to the pyrene concentration in the culture medium. The results showed an adaptation of R. arrhizus UCP 402x (mutant) in the pyrene (50mg/L) and suggested a higher ability of application in the removal of pyrene from the contaminated areas.

Degradation of Benzo [a] Pyrene by a novel strain Bacillus subtilis BMT4i (MTCC 9447)

Lily,Madhuri Kaushish; Bahuguna,Ashutosh; Dangwal,Koushalya; Garg,Veena
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
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Benzo [a] Pyrene (BaP) is a highly recalcitrant, polycyclic aromatic hydrocarbon (PAH) with high genotoxicity and carcinogenicity. It is formed and released into the environment due to incomplete combustion of fossil fuel and various anthropogenic activities including cigarette smoke and automobile exhausts. The aim of present study is to isolate bacteria which can degrade BaP as a sole source of carbon and energy. We have isolated a novel strain BMT4i (MTCC 9447) of Bacillus subtilis from automobile contaminated soil using BaP (50 μg /ml) as the sole source of carbon and energy in basal salt mineral (BSM) medium. The growth kinetics of BMT4i was studied using CFU method which revealed that BMT4i is able to survive in BaP-BSM medium up to 40 days attaining its peak growth (10(29) fold increase in cell number) on 7 days of incubation. The BaP degradation kinetics of BMT4i was studied using High Performance Liquid Chromatography (HPLC) analysis of BaP biodegradation products. BMT4i started degrading BaP after 24 hours and continued up to 28 days achieving maximum degradation of approximately 84.66 %. The above findings inferred that BMT4i is a very efficient degrader of BaP. To our best of knowledge, this is the first report showing utilization of BaP as a sole source of carbon and energy by bacteria. In addition...

Characterization of pyrene utilizing Bacillus spp. from crude oil contaminated soil

Khanna,Purnima; Goyal,Dinesh; Khanna,Sunil
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
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Pyrene, a high molecular weight polycyclic aromatic hydrocarbon (PAH), is a priority pollutant present in soil contaminated with crude oil, coal-tar and complex PAHs. Bacterial consortium CON-3 developed from crude oil contaminated soil of Patiala, Punjab (India) cometabolized 50 µg ml-1 pyrene in the presence of glucose (0.5 %; w/v) at 30 °C, as determined by reverse-phase high performance liquid chromatography (HPLC). Bacillus sp. PK-12, Bacillus sp. PK-13 and Bacillus sp. PK-14 from CON-3, identified by 16S rRNA gene sequence analysis, were able to cometabolize 64 %, 55 % and 53 % of pyrene in 35 days, respectively. With the increase in glucose concentration to 1.0 % (w/v) in growth medium isolates PK-12, PK-13 and PK-14 showed 19 - 46 % uptake of 50 µg ml-1 pyrene in 4 days, respectively. Uptake of pyrene was correlated with growth and biosurfactant activity, which is suggestive of the potential role of members of Bacillus genera in pyrene mobilization and its uptake.

Évaluation de la cytogénotoxicité humaine induite par l’exposition à de faibles doses de benzo-a-pyrène, à l’aide de biomarqueurs précoces

Fortin, Fléchère
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Le benzo-a-pyrène (BaP) est un hydrocarbure aromatique polycyclique (HAP) cancérogène pour l’homme, qui contamine toutes les sphères de notre environnement. Son métabolite, le BaP-7,8-diol-9,10-époxyde (BPDE) est considéré comme son cancérogène ultime. Le BPDE se lie à l’ADN, formant des adduits qui doivent être réparés et qui seraient responsables des dommages à l’ADN et de la cancérogenèse induite par le BaP. Les adduits BPDE-ADN et les dommages à l’ADN (bris simple-brin [BSB] à l’ADN, aberrations chromosomiques [AC], échanges entre chromatides-sœurs [ÉCS] et micronoyaux [MN]) ont été mesurés dans les lymphocytes humains exposés à de faibles concentrations de BaP, provenant de jeunes volontaires non-fumeurs et en santé. Suite à l’exposition au BaP, le niveau d’adduits BPDE-ADN et la fréquence des AC et des MN augmentent significativement, puis diminuent aux concentrations les plus élevées de BaP testées, suggérant une induction du métabolisme de phase II du BaP. Lors de la mesure des ÉCS, nous obtenons une courbe dose-réponse linéaire, indiquant la production d’un autre type de lésions devant être réparées par le système de réparation par recombinaison homologue. Ces lésions pourraient être des bris à l’ADN ou des bases oxydées (8-OH-dG)...

Étude du continuum exposition-effet cancérogène du benzo[a]pyrène

Moreau, Marjory
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Le benzo[a]pyrène (BaP) est un contaminant environnemental de la famille des hydrocarbures aromatiques polycycliques ayant été classé cancérogène chez l’humain. Cependant, la relation entre l’exposition et les effets est toujours mal documentée. L’objectif de cette thèse était de mieux documenter la relation quantitative entre l’exposition au BaP, l’évolution temporelle des biomarqueurs d’exposition et l’apparition d’altérations biologiques précoces, à partir d’études expérimentales chez le rat. Dans un premier temps, nous avons déterminé l’effet de 4 doses de BaP (0.4, 4, 10 et 40 µmol/kg) sur plusieurs biomarqueurs d’exposition (3- et 7-OHBaP, 4,5- et 7,8-diolBaP, BaPtétrol et 1,6-, 3,6- et 7,8-diones-BaP), les adduits à l’ADN et l’expression de gènes impliqués dans le métabolisme du BaP, la réparation de l’ADN et le stress oxydatif. Le BaP et ses métabolites ont été mesurés dans le sang, les tissus et les excrétas, 8 h et 24 h après l’administration intraveineuse de BaP par chromatographie liquide à ultra haute performance (UHPLC) couplée à la fluorescence. Les adduits à l’ADN ont été quantifiés dans les poumons par immuno-essai en chémoluminescence. L’expression des gènes dans les poumons a été réalisée par PCR quantitative en temps réel (qRT-PCR). Les résultats ont révélé une bonne relation dose-excrétion pour le 3-OHBaP...

Lung apoptosis after intra-pulmonary instillation of Benzo(a)pyrene in Wistar rats

Silva, Baldomero Antonio Kato da; Aydos, Ricardo Dutra; Silva, Iandara Schettert; Pereira, Daniel Martins; Carvalho, Paulo de Tarso Camillo de; Dourado, Doroty Mesquita; Reis, Filipe Abdalla dos; Nacer, Renato Silva
Fonte: Acta Cirurgica Brasileira Publicador: Acta Cirurgica Brasileira
Tipo: Artigo de Revista Científica
POR
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PURPOSE: To evaluate the influence of pulmonary instillation of Benzo[a]pyrene in lung apoptosis of Wistar rats. METHODS: Male Rattus norvegicus albinus, Wistar lineage was carried through an intra-pulmonary instillation of the Benzo[a]pyrene (B[a]P) dilution in alcohol 70%. Three experimental groups had been formed with 08 animals each: Control Group (Alcohol 70%); B[a]P Group 40 mg/kg; e B[a]P Group 80mg/kg, submitted to euthanasia 16 and 18 weeks after the experimental procedure. The pulmonary sections had been processed by TUNEL method and submitted to the histomorphometric analysis to quantify the apoptotic cell number. RESULTS: After 16 weeks, mean of apoptotic cells number in control group (19,3±3,2) was greater than 40mg/Kg group (11,8±1,9; p<0,01) and 80mg/Kg group (7,0±1,4; p<0,01). Significant difference also observed between 40mg/Kg and 80mg/Kg (p<0,05). After 18 weeks, mean of apoptotic cells number in control group (18,0±2,2) was greater than 40mg/Kg group (8,8±1,7; p<0,01) and 80mg/Kg group (5,5±1,3; p<0,01). Significant difference wasn't observed between 40mg/Kg and 80mg/Kg (ns). CONCLUSION: Intra-pulmonary instillation of Benzo[a]pyrene induces significant decrease of apoptotic activity in lung tissue.; OBJETIVO: Avaliar a influência da instilação intrapulmonar de Benzo[a]pireno na apoptose pulmonar de ratos Wistar. MÉTODOS: Rattus norvegicus albinus...

Lung apoptosis after intra-pulmonary instillation of Benzo(a)pyrene in Wistar rats

Silva,Baldomero Antonio Kato da; Aydos,Ricardo Dutra; Silva,Iandara Schettert; Pereira,Daniel Martins; Carvalho,Paulo de Tarso Camillo de; Dourado,Doroty Mesquita; Reis,Filipe Abdalla dos; Nacer,Renato Silva
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2010 EN
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PURPOSE: To evaluate the influence of pulmonary instillation of Benzo[a]pyrene in lung apoptosis of Wistar rats. METHODS: Male Rattus norvegicus albinus, Wistar lineage was carried through an intra-pulmonary instillation of the Benzo[a]pyrene (B[a]P) dilution in alcohol 70%. Three experimental groups had been formed with 08 animals each: Control Group (Alcohol 70%); B[a]P Group 40 mg/kg; e B[a]P Group 80mg/kg, submitted to euthanasia 16 and 18 weeks after the experimental procedure. The pulmonary sections had been processed by TUNEL method and submitted to the histomorphometric analysis to quantify the apoptotic cell number. RESULTS: After 16 weeks, mean of apoptotic cells number in control group (19,3±3,2) was greater than 40mg/Kg group (11,8±1,9; p<0,01) and 80mg/Kg group (7,0±1,4; p<0,01). Significant difference also observed between 40mg/Kg and 80mg/Kg (p<0,05). After 18 weeks, mean of apoptotic cells number in control group (18,0±2,2) was greater than 40mg/Kg group (8,8±1,7; p<0,01) and 80mg/Kg group (5,5±1,3; p<0,01). Significant difference wasn't observed between 40mg/Kg and 80mg/Kg (ns). CONCLUSION: Intra-pulmonary instillation of Benzo[a]pyrene induces significant decrease of apoptotic activity in lung tissue.