Spelling suggestions: "subject:"xenobiotics"" "subject:"xenobioticos""
111 |
ESTUDO DA RELAÇÃO ENTRE OS NÍVEIS DE INDICADORES BIOLÓGICOS DE EXPOSIÇÃO AO TOLUENO E O ESTRESSE OXIDATIVO EM EXPOSTOS OCUPACIONALMENTE A TINTAS / STUDY OF THE RELATIONSHIP BETWEEN THE LEVELS OF BIOLOGICAL EXPOSURE INDICES AND OXIDATIVE STRESS IN OCCUPATIONALLY EXPOSED TO PAINTSMoro, Angela Maria 19 March 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Paints occupational exposure is an important health problem due to the wide variety of chemicals and xenobiotics present in their constitution. Organic solvents and heavy metals
are among the main chemical constituents of paints. In the view of the variety of substances
found in paints, can be noted that painters are simultaneously exposed to various
xenobiotics, suggesting a case of co-exposure or exposure mixed. Biological monitoring is an
essential tool for assessing the risk to health and occupational health practices. Moreover, it
is known that there is a close relationship between the xenobiotics constituents of paints and
oxidative stress, such as toxicological mechanism. In this study was evaluated oxidative
damage by quantification of blood biomarkers of oxidative stress such as malondialdehyde
(MDA), reduced glutathione (GSH), δ-aminolevulinate dehydratase enzyme (ALA-D),
superoxide dismutase (SOD) and catalase (CAT ), in individuals occupationally exposed to
paints (n = 48) and non-exposed subjects (n = 30). Biological monitoring of toluene was
performed by quantification of different biomarkers of exposure, urinary hippuric acid and
ortho-cresol, and blood toluene. For xylene, styrene, ethylbenzene and lead were quantified
urinary levels of methylhippuric acid, mandelic acid, phenylglyoxylic acid and blood lead,
respectively. Despite all IBEs were below the biological limit exposure (BEL), significant
changes in oxidative stress biomarkers were found in exposed group. Plasma levels of MDA
and blood antioxidant enzymes (SOD and CAT) had shown increased in the group of
painters when compared with non-exposed group; this increase was accompanied by GSH
levels depletion and enzyme ALA-D inhibition. It was also observed several correlations
between the oxidative stress biomarkers and biomarkers of exposure to xenobiotics present
in paints. By statistical tests were evaluated which of the paints constituents played the
greatest influence on changes in oxidative stress biomarkers, in this case of co-exposure.
Among the exposure biomarkers tested, blood toluene was suggested as the main
responsible for increased lipid peroxidation; in addition, it was appointed as a new and
important inhibitor of the enzyme ALA-D. Thus, it is suggested that a joint evaluation of
biomarkers of exposure and oxidative stress biomarkers might be useful to ensure, in longterm,
the worker s health. / A exposição ocupacional a tintas representa um importante problema de saúde devido à ampla variedade de substâncias químicas e xenobióticos presentes na sua constituição. Solventes orgânicos e metais pesados encontram-se entre os principais
compostos químicos constituintes das tintas. Tendo em vista a variedade de substâncias presentes na composição das tintas, pode-se constatar que pintores encontram-se simultaneamente expostos a diferentes xenobióticos, caracterizando um processo de coexposição ou exposição mista. A monitorização biológica é uma ferramenta essencial para a avaliação do risco à saúde e práticas de saúde ocupacional. Por outro lado, sabe-se que
existe uma estreita relação entre os xenobióticos constituintes de tintas e o estresse oxidativo, como mecanismo toxicológico. Neste estudo foi avaliado o dano oxidativo, através da quantificação de biomarcadores sanguíneos do estresse oxidativo, como alondialdeído (MDA), glutationa reduzida (GSH), enzima δ-aminolevulinato desidratase (ALA-D), superóxido dismutase (SOD) e catalase (CAT); em indivíduos expostos (n=48) e não
expostos (n=30) ocupacionalmente a tintas. A monitorização biológica do tolueno foi realizada através da quantificação dos diferentes biomarcadores de exposição, ácido hipúrico e orto-cresol urinários, e tolueno sanguíneo. Para xileno, estireno, etilbenzeno e chumbo foram quantificados os níveis urinários dos ácidos metil-hipúrico, mandélico, fenilglioxílico, e chumbo sanguíneo, respectivamente. Apesar de todos os IBEs se
encontrarem abaixo dos índices biológicos máximos permitidos (IBMP), alterações significativas nos biomarcadores do estresse oxidativo foram encontradas no grupo de expostos. Os níveis plasmáticos de MDA e das enzimas sangüíneas antioxidantes (SOD e CAT) se mostraram aumentados no grupo de pintores quando comparados com o grupo não exposto; esse aumento foi acompanhado pela depleção nos níveis de GSH e inibição da
enzima ALA-D. Foram observadas ainda várias correlações entre os biomarcadores do estresse oxidativo e biomarcadores de exposição aos xenobióticos presentes nas tintas.
Através de testes estatísticos foram avaliados quais dos constituintes das tintas desempenhavam maior influência sobre as alterações nos biomarcadores de estresse oxidativo, nesse caso de co-exposição. Dentre os biomarcadores de exposição analisados, o tolueno sanguíneo foi sugerido como o principal responsável pelo aumento da peroxidação lipídica; além de ser apontado como um novo e importante inibidor da enzima ALA-D. Dessa forma, sugere-se que a avaliação conjunta de biomarcadores de exposição e biomarcadores do estresse oxidativo possa ser útil para assegurar, em longo, prazo a saúde do trabalhador.
|
112 |
Approche in vivo/in vitro du métabolisme de perturbateurs endocriniens chez le poisson zèbre (Danio rerio) / In vivo/ in vitro metabolic fate of endocrine disruptors in zebrafish (Danio rerio) modelsLe Fol, Vincent 17 December 2015 (has links)
Les perturbateurs endocriniens (PE) posent des risques pour la santé Humaine et pour la faune. L’utilisation de tests biologiques basés sur des mécanismes d’action spécifiques permet de caractériser le potentiel PE des substances chimiques dans le cadre de l'évaluation toxicologique, mais les capacités de biotransformation de ces modèles sont rarement prises en compte. Or, le métabolisme conditionne le devenir des xénobiotiques (détoxication vs. bioactivation) et donc in fine l'activité biologique mesurée. Dans ce travail, le devenir de deux contaminants œstrogéniques émergents (benzophénone-2, bisphénol S) a été comparé dans de nouveaux modèles in vitro et in vivo de poisson zèbre (cellules ZELH-zfERs, larve transgénique cyp19a1b-GFP) et des lignées humaines. Nos résultats démontrent que les modèles de poissons zèbres sont métaboliquement compétents et soulignent leur pertinence dans une approche intégrée in vivo/in vitro pour le criblage de l'activité PE des substances chimiques. / Endocrine disruptors (ED) are potentially harmful for Human beings and for wildlife species. Species-specific mechanism-based screening tests nowadays allow characterizing the ED potency of chemicals in the context of their toxicological assessment. However, the biotransformation capabilities of the biological models used are seldom taken into consideration, despite they ultimately condition the fate of the tested xenobiotics (detoxification vs. bioactivation), and, consequently, the biological response. In this work, we examined the fate of two emerging ED (benzophenone-2, bisphenol S) using novel in vitro and in vivo zebrafish models (ZELH-zfERs cells and cyp19a1b-GFP transgenic larvae) as well as human cell lines. Our results demonstrate that the zebrafish models are metabolically competent, and underline their relevance, accuracy and usefulness in an integrated in vivo/in vitro screening approach designed to assess ED's biological activity
|
113 |
Využití oxidačních procesů (AOP) pro odstraňování mikropolutantů / Use of oxidation processes (AOP) for removal of micropolutantsStříteský, Luboš January 2013 (has links)
This thesis deals with advanced oxidation processes (AOPs) and it’s use for removal of micropollutants from wastewater. The first chapter explains the need AOPs, water quality, pollution and substances that are present in the water. Further, the first chapter outlines approach of the current legislation to micropollutants. The second chapter explains the theory and principle of operation of AOPs. This chapter is divided into two sections. The first section describes AOPs, which were tested at selected WWTP. In the second section, there are described some other AOPs. The third chapter is a literature retrieval of AOPs dealing with the removal of micropollutants. This chapter is focused on the removal of hormones by AOPs using ozone-based AOPs. The fourth chapter describes the actual testing of selected AOPs. The chapter describes selected WWTP, pilot-scale AOP unit and test results. In the last chapter there is designed and described full-scale AOP tertiary unit for removing of micropollutants. The last chapter also contains economic analysis of the proposed tertiary unit.
|
114 |
Efeitos da inalação da fumaça do cigarro no estresse oxidativo do sistema nervoso central de camundongos jovens / Effects of cigarette smoke in oxidative stress in the central nervous system of young miceTôrres, Larissa Helena Lôbo 25 August 2009 (has links)
A fumaça do cigarro é composta por mais de 4.700 substâncias, muitas das quais tóxicas. O sistema nervoso central (SNC) possui poucas defesas antioxidantes, além de ser rico em lipídeos facilmente oxidáveis e de conter alto teor de metais de transição envolvidos na formação de radicais livres. Existem evidências de que a fumaça do cigarro causa alterações nas enzimas antioxidantes em roedores adultos, mas pouco se sabe sobre os efeitos do tabaco no SNC ainda em desenvolvimento. Assim, este trabalho tem como objetivo avaliar os possíveis efeitos da fumaça do cigarro no SNC de camundongos jovens. Camundongos BALB/c foram expostos a uma mistura de fumaça central e lateral do cigarro (Souza Cruz - Derby Vermelho) dentro de uma câmara de polipropileno acoplada a um sistema Venturi. Além da exposição aguda, realizada no 18º dia de vida, os animais foram expostos a partir do 5º dia de vida por 13 ou 35 dias, durante 2 horas por dia, 7 dias por semana. Os animais foram então eutanasiados por deslocamento cervical imediatamente ou três horas após a última exposição e foram realizadas as determinações das atividades enzimáticas da glutationa peroxidase, glutationa redutase, glutationa S-transferase, além da quantificação de malonaldeído (MDA) e 3-nitrotirosina no cerebelo, córtex frontal, estriado, hipocampo e hipotálamo. Nossos resultados indicam que o SNC em desenvolvimento é susceptível à fumaça do cigarro. Foram detectadas alterações nas enzimas antioxidantes em diferentes estruturas encefálicas imediatamente após a última exposição sugerindo diferença de sensibilidade das diferentes áreas à fumaça do cigarro. Contudo, essas perturbações não são persistentes, uma vez que a maior parte delas desapareceu três horas após a exposição. O cerebelo parece ser a estrutura mais resistente enquanto o córtex frontal e o estriado, as mais sensíveis. No córtex frontal as alterações enzimáticas são mais persistentes e houve aumento de MDA no grupo agudo e eutanásia 3 horas após a exposição, enquanto no cerebelo, estriado e hipocampo houve aumento de MDA no grupo agudo e eutanásia imediatamente após a exposição. Esses resultados sugerem uma resposta mais tardia do córtex frontal e uma possível adaptação dos tecidos ao xenobiótico. É importante destacar que a eutanásia realizada imediatamente após a exposição crônica à fumaça do cigarro não reflete somente o efeito da última exposição, já que tanto o padrão encontrado na alteração das enzimas quanto na determinação de MDA foi diferente do observado após exposição aguda. / Cigarette\'s smoke is composed of more than 4.700 substances, many of them are toxic. The central nervous system (CNS) has few antioxidant defenses, is rich in easily oxidable lipids and contains high levels of transition metals which are involved in the formation of free radicals. There are evidences that tobacco smoke causes changes in the antioxidant enzymes in adult rodents, but little is known about its effects during CNS development. Thus, the aim of this work was to evaluate the possible effects of cigarettes smoke in the CNS of young mice. BALB/c mice were exposed to a mixture of mainstream and sidestream smoke of cigarette (Souza Cruz Red Derby) in a polypropylene chamber attached to a Venturi system. Besides acute exposure, performed at the 18th day of life, the animals were exposed from the 5th day of life for 13 or 35 days, 2 hours a day, 7 days in a week. The animals were then euthanized by cervical dislocation, immediately or three hours after the last exposure. The determinations of enzymatic activities of glutathione peroxidase, glutathione reductase, glutathione S-transferase, and the quantification of malonaldehyde (MDA) and 3-nitrotyrosine in cerebellum, frontal cortex, striatum, hippocampus and hypothalamus were performed. Our results indicate that the CNS in development is susceptible to cigarettes smoke. Alterations in antioxidant enzymes in different brain structures were detected immediately after the last exposure suggesting differences in sensitivity of different areas to cigarette\'s smoke. However, these disturbances are not persistent, as most of them disappeared three hours after exposure. Cerebellum seems to be the more resistant structure, while frontal cortex and striatum the most sensitive. Enzyme changes in frontal cortex were more persistent and there was an increase of MDA only in the acute group and euthanasia 3 hours after exposure, whereas in cerebellum, striatum and hippocampus, MDA increased only in acute group and immediately euthanasia after exposure. These results suggest a delayed response of the frontal cortex and a possible adaptation of tissues to xenobiotics. It is important to point out that euthanasia performed immediately after chronic exposure to cigarette smoke not only reflect the effect of the last exposure, since the pattern found in the modification of enzymes and in the determination of MDA was different from that observed after acute exposure.
|
115 |
Marcadores de estresse oxidativo em Minutocellus polymorphus (Heterokontophyta) sob exposição ao oxifluorfeno e ao benzo [a]pireno / Oxidative stress markers in Minutocellus polymorphus (Heterokontophyta) under oxyfluorfen and benzo[a]pyrene exposureTorres, Moacir Aluisio 17 November 2008 (has links)
Nesse trabalho enfatizamos o uso de marcadores bioquímicos de estresse oxidativo em microalgas como sinalizadores precoces de exposição a agentes xenobióticos. A curva de crescimento e a taxa de crescimento diário (µ) foram determinadas através do monitoramento in vivo da fluorescência da clorofila. Baseado nos protocolos de testes toxicológicos in vitro, usando microalgas expostas por 48h, determinou-se a concentração efetiva que inibiu 50% de µ (IC50). Culturas de M. polymorphus, com concentração inicial de 1 X 106 células.mL-1, foram submetidas separadamente ao IC50 de oxiflurfeno (OxF) e benzo[a]pireno (BaP) por 48h sendo, posteriormente, coletadas para a análise de cinética enzimática em espectrofotômetro. As análises tanto dos níveis de MDA como dos níveis de GSH/GSSG e Asc- foram feitas em HPLC usando detectores de fluorescência e detectores coulométricos flow-through respectivamente. Além disso, os ensaios sobre a excreção/liberação de H2O2 in vivo foram feitos em um luminômetro usando-se a técnica do luminol. Os valores de IC50 para o OxF e BaP foram de 0,24 µg.L-1 e 0,99 µg.L-1 respectivamente. Os resultados das análises enzimáticas, obtidos nos ensaios com OxF, ao serem comparadas com controles, mostram aumentos para SOD (150 ± 7 e 32 ± 6 USOD.mg.prot-1), seguidos por aumentos menores para CAT (6,5 ± 0,7 e 3,9 ± 0,5 U.mg.prot.-1) e APx (1,01 ± 0,06 e 0,82 ± 0,05 U.mg.prot.-1) respectivamente. Nas culturas expostas ao BaP os resultados, comparados ao controle, mostraram maior atividade de CAT (35,7 ± 1,3 e 4,0 ± 0,9 U.mg.prot.-1) e APx (4,95 ± 0,06 e 0,86 ± 0,03 U.mg.prot.-1) enquanto a SOD foi menos pronunciada (105 ± 6 e 35 ± 5 USOD.mg.prot.-1). As análises das enzimas GR e DHAR quando comparadas ao controle (0,78 ± 0,07 e 0,43 ± 0,08 U.mg.prot.-1 respectivamente) apresentaram-se inibidas em quase 50% quando sob a ação de OxF e não apresentaram variações na presença de BaP. As análises de GST comparadas aos controles, tiveram menor atividade nos grupos sob OxF (176 ± 28 e 73 ± 18 ) frente ao BaP (402 ± 67 e 71 ± 24). Os resultados em HPLC revelaram níveis de MDA elevados nos dois grupos, especificamente 9 e 5 vezes o valor dos controles para as amostras expostas ao OxF e ao BaP respectivamente. Os resultados de GSH mostram diminuição de GSHtotal frente aos controles, em quase 40% sob ação do OxF e mais de 50% nas culturas com BaP. Além disso, a percentagem de GSH na forma de GSSG comparada ao GSHtotal (%IR Índice redox) foi de 60 e 75% nos grupos com OxF e BaP respectivamente. Nos valores obtidos nas análises de Asc- os resultados apontam diminuição em 45% sob OxF e pouco mais de 15% na presença de BaP. As análises de excreção/liberação in vivo de H2O2 mostram acentuada liberação nas células expostas ao OxF quando comparadas ao tratamento com BaP. A observação dos valores de IC50, mostra uma maior toxicidade de OxF quando comparada ao BaP e os resultados das análises das enzimas antioxidantes nos revelam que M. polymorphus usa diferentes estratégias frente aos agentes tóxicos. Tendo em vista a inibição de CAT e APx, as células sob exposição ao OxF utilizam a eliminação direta de H2O2 no meio e, eliminação via ação da GST. No entanto, tal situação parece não diminuir os níveis de lipoperoxidação, mesmo com consumo excessivo de Asc. As culturas expostas ao BaP evitam a evolução de H2O2 via atividade enzimática preferencial e os níveis baixos de GSH denotam a utilização de GST em processos de conjugação de xenobióticos. / The use of biochemical oxidative stress biomarkers in microalgae, as early watches during xenobiotic exposure are emphasized. The growth curve and the diary cells population increase rate (µ) were determined by chlorophyll fluorescence in vivo monitoring. Applying toxicological in vitro tests protocols and using microalgae exposed for 48h, we have determined the effective concentration that provoked 50% of µ inhibition (IC50). M. polymorphus cultures in an initial cellular concentration of 1 X 106 cell.mL-1 were separately submitted to IC50 oxyfluorfen (OxF) and benzo[a]pyrene (BaP) during 48h and, after that, they were gathered to the kinetics enzymatic assay using spectrophotometer. The levels of MDA and the levels of GSH/GSSG plus Asc- were determined in the HPLC system coupling to the fluorescence and coulometric flow-through detectors, respectively. Additionally, in vivo H2O2 excretion/releasing assays were done using a luminometer associated to the luminol technique. The IC50 obtained in the OxF and BaP tests brought out the values 0.24 µ.L-1 and 0.99 µg.L-1 respectively. The results from the enzymatic analyses in the culture under OxF exposure, when compared to the controls, have shown increases in the SOD activities (150 ± 7 and 32 ± 6 USOD.mg.prot-1) followed by minor results to CAT (6.5 ± 0.7 and 3.9 ± 0.5 U.mg.prot.-1) and APx activities (1.01 ± 0.06 and 0.82 ± 0.05 U.mg.prot.-1), respectively. On the other hand, in cultures under BaP treatment, the results compared to the control have shown an increase of CAT (35.7 ± 1.3 and 4.0 ± 0.9 U.mg.prot.-1) and APx activities (4.95 ± 0.06 and 0.86 ± 0.03 U.mg.prot.-1) followed by minor SOD activities (105 ± 6 and 35 ± 5 USOD.mg.prot-1). The results from enzymatic analyses of GR and DHAR under OxF exposure presented around 50% of controls value (0.78 ± 0.07 and 0.43 ± 0.08 U.mg.prot.-1respectively). Contrarily, the culture under BaP treatment didnt show any variation compared to the controls. Instead, GST analyses - in the culture under OxF treatment - have shown minor activity (176 ± 28 and 73 ± 18) facing the cell cultures under BaP exposure (402 ± 67 and 71 ± 24), when compared to the controls. In the cultures under OxF and BaP treatment, HPLC analyses displayed an increase of 9 and 5 fold, respectively, in the MDA levels. The results of GSH in cultures under OxF have shown a decrease of 40% GSHtotal when compared to the control, and more than 50% in cultures under BaP treatment. In addition, the percentage of GSH in the GSSG form compared to GSHtotal (%RI Redox index) was 60 and 75% in the OxF and BaP groups, respectively. In the results obtained in analyses of Asc- there are a decrease of 45% in cultures under OxF and a little bit more than 15% in cultures under BaP treatment. The analyses of in vivo H2O2 excretion/releasing have shown pronounced freeing in the cell under OxF exposure when compared with BaP cultures. The results of IC50 value point to an increased toxicity in cells under OxF treatment in comparison to BaP cultures. On the other hand the results of antioxidant enzymes have shown us different strategies used by M. polymorphus facing the toxic agents. Having in mind the inhibition of CAT and APx, the cells under OxF exposure adopt the direct elimination of H2O2 in the culture medium and via GST activity. However, this situation seems not reduce the lipoperoxidation levels, not even, under the exceedingly Asc- consuming. Cultures exposed to BaP avoid H2O2 evolution de mainly via enzymatic activity and the lower levels of GSH pointing to the activity of GST during xenobiotic conjugation process.
|
116 |
Metabolic activation of drugs and other xenobiotics in hepatocellular carcinoma.January 1993 (has links)
Grace S.N. Lau. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 335-362). / List of Abbreviations --- p.i / Abstract --- p.1 / Chapter Chapter 1 --- General Introduction and Study Objectives / Chapter 1.1 --- Metabolic activation - role in drug toxicity and carcinogenesis --- p.5 / Chapter 1.2 --- Hepatocellular carcinoma --- p.12 / Chapter 1.2.1 --- Epidemiology --- p.12 / Chapter 1.2.2 --- Aetiological factors --- p.17 / Chapter 1.2.2.1 --- Hepatitis B virus infection --- p.17 / Chapter 1.2.2.2 --- Cirrhosis --- p.24 / Chapter 1.2.2.3 --- Aflatoxins --- p.25 / Chapter 1.2.2.4 --- Other factors --- p.26 / Chapter 1.2.2.5 --- Summary --- p.29 / Chapter 1.3 --- Study objectives --- p.30 / Chapter Chapter 2 --- The Metabolism of Paracetamol in Healthy Subjects andin Patients with Liver Disease and Hepatocellular Carcinoma / Chapter 2.1 --- Introduction --- p.34 / Chapter 2.1.1. --- History of paracetamol --- p.34 / Chapter 2.1.2 --- Pharmacology of paracetamol --- p.37 / Chapter 2.1.3 --- "Absorption, Distribution, Metabolism and Excretion" --- p.38 / Chapter 2.1.3.1 --- Absorption --- p.38 / Chapter 2.1.3.2 --- Distribution --- p.41 / Chapter 2.1.3.3 --- Metabolism --- p.42 / Chapter 2.1.3.4 --- Excretion --- p.57 / Chapter 2.1.4 --- Toxicity and Overdosage --- p.59 / Chapter 2.2 --- Estimation of paracetamol and its metabolites in plasma and urine by high performance liquid chromatography --- p.72 / Chapter 2.2.1 --- Introduction --- p.72 / Chapter 2.2.2 --- Analytical method --- p.76 / Chapter 2.2.2.1 --- Materials --- p.76 / Chapter 2.2.2.2 --- Instrumentation --- p.77 / Chapter 2.2.2.3 --- Collection and storage of samples --- p.79 / Chapter 2.2.2.4 --- Chromatographic conditions --- p.79 / Chapter 2.2.3 --- Urine assay --- p.79 / Chapter 2.2.3.1 --- Preparation of standards and test samples for urine assay --- p.79 / Chapter 2.2.3.2 --- Calculation of results for urine assay --- p.80 / Chapter 2.2.3.3 --- Results of urine assay --- p.81 / Chapter 2.2.3.4 --- Validation of urine assay --- p.81 / Chapter 2.2.4 --- Plasma assay --- p.83 / Chapter 2.2.4.1 --- Preparation of standards and test samples for plasma assay --- p.83 / Chapter 2.2.4.2 --- Calculation of results for plasma assay --- p.91 / Chapter 2.2.4.3 --- Results of plasma assay --- p.91 / Chapter 2.2.4.4 --- Validation of plasma assay --- p.93 / Chapter 2.2.5 --- Summary --- p.99 / Chapter 2.3 --- The pharmacokinetics of paracetamol in healthy subjects --- p.103 / Chapter 2.3.1 --- Introduction --- p.103 / Chapter 2.3.2 --- Study protocol --- p.103 / Chapter 2.3.3 --- Methods --- p.103 / Chapter 2.3.3.1 --- Subjects --- p.103 / Chapter 2.3.3.2 --- Drug administration and sampling --- p.104 / Chapter 2.3.3.3 --- Drug analysis --- p.108 / Chapter 2.3.3.4 --- Calculations --- p.108 / Chapter 2.3.4 --- Pharmacokinetic analysis --- p.109 / Chapter 2.3.5 --- Statistical analysis --- p.113 / Chapter 2.3.6 --- Results --- p.114 / Chapter 2.3.6.1 --- Plasma Results --- p.114 / Chapter 2.3.6.2 --- Urine Results --- p.118 / Chapter 2.3.6.3 --- Pharmacokinetic Results --- p.125 / Chapter 2.3.6.4 --- Statistical Results --- p.134 / Chapter 2.3.7 --- Discussion --- p.145 / Chapter 2.4 --- "The pharmacokinetics of paracetamol in healthy subjects, patients with liver disease and hepatocellular carcinoma" --- p.155 / Chapter 2.4.1 --- Introduction --- p.155 / Chapter 2.4.2 --- Study protocol --- p.156 / Chapter 2.4.3 --- Methods --- p.156 / Chapter 2.4.3.1 --- Subjects --- p.156 / Chapter 2.4.3.2 --- Drug administration and sampling --- p.157 / Chapter 2.4.3.3 --- Drug analysis --- p.160 / Chapter 2.4.3.4 --- Calculations --- p.160 / Chapter 2.4.4 --- Pharmacokinetic analysis --- p.161 / Chapter 2.4.6 --- Results --- p.162 / Chapter 2.4.6.1 --- Plasma Results --- p.162 / Chapter 2.4.6.2 --- Urine Results --- p.162 / Chapter 2.4.6.3 --- Pharmacokinetic Results --- p.179 / Chapter 2.4.7 --- Discussion --- p.194 / Chapter 2.4.8 --- Summary --- p.203 / Chapter Chapter 3 --- Metabolic Activation of Aflatoxin B1 in Healthy Subjects and in Patients with Liver Disease and Hepatocellular Carcinoma / Chapter 3.1 --- General introduction --- p.206 / Chapter 3.1.1 --- Chemical structures and properties --- p.207 / Chapter 3.1.2 --- Contamination of food by aflatoxins --- p.209 / Chapter 3.1.3 --- Metabolism of aflatoxins --- p.210 / Chapter 3.1.4 --- Human diseases possibly related to exposure to aflatoxins --- p.226 / Chapter 3.1.4.1 --- Acute aflatoxicosis --- p.226 / Chapter 3.1.4.2 --- Reye's syndrome --- p.227 / Chapter 3.1.4.3 --- Kwashiorkor --- p.228 / Chapter 3.1.4.4 --- Impaired immune function --- p.229 / Chapter 3.1.4.5 --- Hepatocellular carcinoma --- p.230 / Chapter 3.1.5 --- Biochemical and molecular epidemiology of aflatoxins --- p.232 / Chapter 3.2 --- Development of an ELISA method to monitor AFB1 exposure in human serum --- p.237 / Chapter 3.2.1 --- Introduction --- p.237 / Chapter 3.2.2 --- Preparation of all the components necessary for analysing AFB1-albumin adducts by ELISA --- p.243 / Chapter 3.2.2.1 --- Materials --- p.243 / Chapter 3.2.2.2 --- Preparation of rabbit AFB1 antiserum --- p.244 / Chapter 3.2.2.3 --- Preparation of the rat monoclonal antibody --- p.244 / Chapter 3.2.2.4 --- Concentration of cell culture supernatant by ammonium sulphate precipitation --- p.246 / Chapter 3.2.2.5 --- Preparation of the BSA-AFB1 conjugate --- p.248 / Chapter 3.2.2.6 --- Preparation of the immunoaffinity gel --- p.250 / Chapter 3.2.2.7 --- Preparation of the ELISA plates --- p.251 / Chapter 3.2.3 --- General procedures used in the analysis of AFB1- albumin adducts --- p.252 / Chapter 3.2.3.1 --- Competitive ELISA binding assay --- p.253 / Chapter 3.2.3.2 --- Sep-pak C18 cartridge --- p.254 / Chapter 3.2.3.3 --- Immunoaffinity column --- p.255 / Chapter 3.2.3.4 --- Evaporation process --- p.255 / Chapter 3.2.3.5 --- HPLC --- p.256 / Chapter 3.2.3.6 --- Radioactive counting --- p.256 / Chapter 3.2.3.7 --- Albumin isolation --- p.257 / Chapter 3.2.3.8 --- Digestion of albumin --- p.257 / Chapter 3.2.3.9 --- Animal procedures --- p.258 / Chapter 3.2.4 --- Validations --- p.259 / Chapter 3.2.4.1 --- Analysis of standard AFB1 and AFB1- lysine in ELISA --- p.259 / Chapter 3 2.4.2 --- Optimisation of antiserum dilution and concentration of coating antigenin ELISA --- p.259 / Chapter 3 2.4.3 --- Elution characteristics and capacity of the immunoaffinity column --- p.261 / Chapter 3.2.4.4 --- Comparison of immunoaffinity gels prepared with different affinity gels --- p.261 / Chapter 3.2.4.5 --- Immunoaffinity column experiment of AFB1-lysine --- p.263 / Chapter 3.2.4.6 --- HPLC Analysis of fractions from immunoaffinity column --- p.263 / Chapter 3.2.4.8 --- HPLC analysis of fractions from Sep- Pak C18 cartridge --- p.264 / Chapter 3.2.4.9 --- Digestion of serum albumin by proteinase K --- p.264 / Chapter 3.2.4.10 --- Effect of ethanol in samples to be loaded onto Sep-Pak C18 cartridge --- p.265 / Chapter 3.2.4.11 --- Effect of drying in a vacuum concentrator on recovery of radioactivity of 3H-AFB1 --- p.266 / Chapter 3.2.4.12 --- Evaluation of the overall procedure for the analysis of serum albumin adducts of AFB1 --- p.267 / Chapter 3.2.4.13 --- HPLC analysis of samples obtained after digestion and all clean-up procedures --- p.268 / Chapter 3.2.5 --- Results and discussion --- p.268 / Chapter 3.2.5.1 --- BSA-AFB1 conjugate --- p.268 / Chapter 3.2.5.2 --- Treatment of experimental animals with 3H-AFB1 --- p.270 / Chapter 3.2.5.3 --- Optimisation of antiserum dilution and concentration of coating antigenin ELISA --- p.272 / Chapter 3.2.5.4 --- Analysis of standard AFB1 and AFB1- lysine in ELISA --- p.275 / Chapter 3.2.5.5 --- Sep-Pak C18 cartridge - elution characteristics and capacity --- p.279 / Chapter 3.2.5.6 --- Elution characteristics of immunoaffinity columns --- p.282 / Chapter 3.2.5.7 --- Immunoaffinity column experiment of AFB1-lysine --- p.290 / Chapter 3.2.5.8 --- Digestion of serum albumin by proteinase K --- p.295 / Chapter 3.2.5.9 --- Effect of ethanol in samples to be applied onto Sep-Pak C18 cartridges --- p.297 / Chapter 3.2.5.10 --- Recovery of radioactivity after dryingin a vacuum concentrator --- p.300 / Chapter 3.2.5.11 --- Recovery of the overall clean-up procedure for the analysis of serum albumin adducts of AFB1 --- p.300 / Chapter 3.2.5.12 --- HPLC analysis of samples obtained after all clean-up procedures --- p.305 / Chapter 3.2.5.13 --- The use of rabbit anti-AFB1 anti-serum and rat anti-AFB1 monoclonal antibody --- p.308 / Chapter 3.2.6 --- Summary --- p.309 / Chapter 3.3 --- Monitoring of AFBralbumin adducts in plasma of patients with liver disease and hepatocellular carcinoma --- p.311 / Chapter 3.3.1 --- Introduction --- p.311 / Chapter 3.3.2 --- Material and methods --- p.314 / Chapter 3.3.2.1 --- Subject --- p.314 / Chapter 3.3.2.2 --- Sample collections --- p.315 / Chapter 3.3.2.4 --- Assay for AFB1-albumin adducts --- p.315 / Chapter 3.3.2.5 --- Statistical analysis --- p.318 / Chapter 3.3.3 --- Results and discussion --- p.318 / Chapter Chapter 4 --- Summary and Ideas for Further Studies --- p.330 / Acknowledgements --- p.333 / References --- p.335 / Appendices --- p.364
|
117 |
Relação da nutrição apícola com a microbiota do pólen e do sistema digestório de abelhas melíferas verificada por sequenciamento de nova geraçãoSaraiva, Miriane Acosta 16 March 2015 (has links)
Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-09-12T20:02:35Z
No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
Relação Da Nutrição Apícola Com A Microbiota Do Pólen E Do Sistema Digestório De Abelhas Melíferas Verificada Por Sequenciamento De Nova Geração.pdf: 2887795 bytes, checksum: 12218b912a445c8eb21706a94911e90f (MD5) / Made available in DSpace on 2016-09-12T20:02:35Z (GMT). No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
Relação Da Nutrição Apícola Com A Microbiota Do Pólen E Do Sistema Digestório De Abelhas Melíferas Verificada Por Sequenciamento De Nova Geração.pdf: 2887795 bytes, checksum: 12218b912a445c8eb21706a94911e90f (MD5)
Previous issue date: 2015-03-16 / A microbiota e os genes funcionais ativamente envolvidos no processo de decomposição e utilização de grãos de pólen em pão de mel e no trato digestório de abelha ainda não são completamente compreendidos. O objetivo deste trabalho foi avaliar a estrutura e diversidade da
comunidade de bactérias e Archaeas em amostrasde pão de mel e sistema digestório de abelhas
africanizadas, bem como para prever os genes envolvido na bioprocessamento microbiano do pólen, usando a tecnologia de seqüenciamento de nova geração. Um total de 11 filos bacterianos foram encontrados dentro do sistema de digestório de abelhas e 10 filos bacterianos foram encontrado dentro pão de mel. Embora a comparação a nível de filo mostre mais filos em comum, a análise filogenética mais profunda mostrou maior variação de composição taxonômica. A família Enterobacteriaceae, Ricketsiaceae, Spiroplasmataceae e Bacillaceae, foram os principais grupos responsáveis por a especificidade do intestino de abelhas, enquanto as principais famílias responsáveis pela especificidade do pão de mel foram Neisseriaceae, Flavobacteriaceae, Acetobacteraceae e Lactobacillaceae. Em termos da estrutura da comunidade microbiana, a análise mostrou que as comunidades dos dois ambientes foram bastante diferentes umas das outras, com apenas 7% dos táxons a nível de espécies compartilhados entre o sitema digestório de abelhas e o pão de mel. Os resultados indicaram a presença de um elevado nível de especialização e uma microbiota intestinal bem adaptada dentro de cada abelha e do pão de mel.A comunidade associada ao pão de mel, apresentou maior abundância relativa de genes relacionados com a degradação de aminoácidos, carboidratos, e o metabolismo lipídico, sugerindo que biodegradação do pólen ocorre predominantemente pela microbiota associada ao pão de mel. Estes resultados sugerem uma complexa e importante relação entre nutrição de abelhas e suas comunidades microbianas. / The microbiota and the functional genes actively involved in the process of breakdown and
utilization of pollen grains in beebread and beeguts are not yet understood. The aim of this work
was to assess the diversity and community structure of bacteria and archaea in Africanized
honeybee guts and beebread as well as to predict the genes involved in the microbial
bioprocessing of pollen using state of the art ‘post-light’ based sequencing technology. A total of
11 bacterial phyla were found within bee guts and 10 bacterial phyla were found within
beebread. Although the phylum level comparison shows most phyla in common, a deeper
phylogenetic analysis showed greater variation of taxonomic composition. The families
Enterobacteriaceae, Ricketsiaceae, Spiroplasmataceae and Bacillaceae, were the main groups
responsible for the specificity of the bee gut while the main families responsible for the
specificity of the beebread were Neisseriaceae, Flavobacteriaceae, Acetobacteraceae and
Lactobacillaceae. In terms of microbial community structure, the analysis showed that the
communities from the two environments were quite different from each other with only 7 % of
species-level taxa shared between beegut and beebread. The results indicated the presence of a
highly specialized and well-adapted microbiota within each bee gut and beebread. The beebread
community included a greater relative abundance of genes related to amino acid, carbohydrate,
and lipid metabolism, suggesting that pollen biodegradation predominantly occurs in the
beebread. These results suggests a complex and important relationship between honeybee
nutrition and their microbial communities.
|
118 |
Efeitos da inalação da fumaça do cigarro no estresse oxidativo do sistema nervoso central de camundongos jovens / Effects of cigarette smoke in oxidative stress in the central nervous system of young miceLarissa Helena Lôbo Tôrres 25 August 2009 (has links)
A fumaça do cigarro é composta por mais de 4.700 substâncias, muitas das quais tóxicas. O sistema nervoso central (SNC) possui poucas defesas antioxidantes, além de ser rico em lipídeos facilmente oxidáveis e de conter alto teor de metais de transição envolvidos na formação de radicais livres. Existem evidências de que a fumaça do cigarro causa alterações nas enzimas antioxidantes em roedores adultos, mas pouco se sabe sobre os efeitos do tabaco no SNC ainda em desenvolvimento. Assim, este trabalho tem como objetivo avaliar os possíveis efeitos da fumaça do cigarro no SNC de camundongos jovens. Camundongos BALB/c foram expostos a uma mistura de fumaça central e lateral do cigarro (Souza Cruz - Derby Vermelho) dentro de uma câmara de polipropileno acoplada a um sistema Venturi. Além da exposição aguda, realizada no 18º dia de vida, os animais foram expostos a partir do 5º dia de vida por 13 ou 35 dias, durante 2 horas por dia, 7 dias por semana. Os animais foram então eutanasiados por deslocamento cervical imediatamente ou três horas após a última exposição e foram realizadas as determinações das atividades enzimáticas da glutationa peroxidase, glutationa redutase, glutationa S-transferase, além da quantificação de malonaldeído (MDA) e 3-nitrotirosina no cerebelo, córtex frontal, estriado, hipocampo e hipotálamo. Nossos resultados indicam que o SNC em desenvolvimento é susceptível à fumaça do cigarro. Foram detectadas alterações nas enzimas antioxidantes em diferentes estruturas encefálicas imediatamente após a última exposição sugerindo diferença de sensibilidade das diferentes áreas à fumaça do cigarro. Contudo, essas perturbações não são persistentes, uma vez que a maior parte delas desapareceu três horas após a exposição. O cerebelo parece ser a estrutura mais resistente enquanto o córtex frontal e o estriado, as mais sensíveis. No córtex frontal as alterações enzimáticas são mais persistentes e houve aumento de MDA no grupo agudo e eutanásia 3 horas após a exposição, enquanto no cerebelo, estriado e hipocampo houve aumento de MDA no grupo agudo e eutanásia imediatamente após a exposição. Esses resultados sugerem uma resposta mais tardia do córtex frontal e uma possível adaptação dos tecidos ao xenobiótico. É importante destacar que a eutanásia realizada imediatamente após a exposição crônica à fumaça do cigarro não reflete somente o efeito da última exposição, já que tanto o padrão encontrado na alteração das enzimas quanto na determinação de MDA foi diferente do observado após exposição aguda. / Cigarette\'s smoke is composed of more than 4.700 substances, many of them are toxic. The central nervous system (CNS) has few antioxidant defenses, is rich in easily oxidable lipids and contains high levels of transition metals which are involved in the formation of free radicals. There are evidences that tobacco smoke causes changes in the antioxidant enzymes in adult rodents, but little is known about its effects during CNS development. Thus, the aim of this work was to evaluate the possible effects of cigarettes smoke in the CNS of young mice. BALB/c mice were exposed to a mixture of mainstream and sidestream smoke of cigarette (Souza Cruz Red Derby) in a polypropylene chamber attached to a Venturi system. Besides acute exposure, performed at the 18th day of life, the animals were exposed from the 5th day of life for 13 or 35 days, 2 hours a day, 7 days in a week. The animals were then euthanized by cervical dislocation, immediately or three hours after the last exposure. The determinations of enzymatic activities of glutathione peroxidase, glutathione reductase, glutathione S-transferase, and the quantification of malonaldehyde (MDA) and 3-nitrotyrosine in cerebellum, frontal cortex, striatum, hippocampus and hypothalamus were performed. Our results indicate that the CNS in development is susceptible to cigarettes smoke. Alterations in antioxidant enzymes in different brain structures were detected immediately after the last exposure suggesting differences in sensitivity of different areas to cigarette\'s smoke. However, these disturbances are not persistent, as most of them disappeared three hours after exposure. Cerebellum seems to be the more resistant structure, while frontal cortex and striatum the most sensitive. Enzyme changes in frontal cortex were more persistent and there was an increase of MDA only in the acute group and euthanasia 3 hours after exposure, whereas in cerebellum, striatum and hippocampus, MDA increased only in acute group and immediately euthanasia after exposure. These results suggest a delayed response of the frontal cortex and a possible adaptation of tissues to xenobiotics. It is important to point out that euthanasia performed immediately after chronic exposure to cigarette smoke not only reflect the effect of the last exposure, since the pattern found in the modification of enzymes and in the determination of MDA was different from that observed after acute exposure.
|
119 |
Relação da nutrição apícola do pólen e do sistema digestório de abelhas melíferas verificada por sequenciamento de nova geraçãoSaraiva, Miriane Acosta 16 March 2015 (has links)
Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-07-21T18:21:38Z
No. of bitstreams: 1
Relação Da Nutrição Apícola Com A Microbiota Do Pólen E Do Sistema Digestório De Abelhas Melíferas Verificada Por Sequenciamento De Nova Geração.pdf: 2887795 bytes, checksum: 12218b912a445c8eb21706a94911e90f (MD5) / Approved for entry into archive by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-08-23T16:34:05Z (GMT) No. of bitstreams: 1
Relação Da Nutrição Apícola Com A Microbiota Do Pólen E Do Sistema Digestório De Abelhas Melíferas Verificada Por Sequenciamento De Nova Geração.pdf: 2887795 bytes, checksum: 12218b912a445c8eb21706a94911e90f (MD5) / Made available in DSpace on 2016-08-23T16:34:05Z (GMT). No. of bitstreams: 1
Relação Da Nutrição Apícola Com A Microbiota Do Pólen E Do Sistema Digestório De Abelhas Melíferas Verificada Por Sequenciamento De Nova Geração.pdf: 2887795 bytes, checksum: 12218b912a445c8eb21706a94911e90f (MD5)
Previous issue date: 2015-03-16 / A microbiota e os genes funcionais ativamente envolvidos no processo de decomposição e utilização de grãos de pólen em pão de mel e no trato digestório de abelha ainda não são completamente compreendidos. O objetivo deste trabalho foi avaliar a estrutura e diversidade da comunidade de bactérias e Archaeas em amostrasde pão de mel e sistema digestório de abelhas africanizadas, bem como para prever os genes envolvido na bioprocessamento microbiano do pólen, usando a tecnologia de seqüenciamento de nova geração. Um total de 11 filos bacterianos foram encontrados dentro do sistema de digestório de abelhas e 10 filos bacterianos foram encontrado dentro pão de mel. Embora a comparação a nível de filo mostre mais filos em comum, a análise filogenética mais profunda mostrou maior variação de composição taxonômica. A família Enterobacteriaceae, Ricketsiaceae, Spiroplasmataceae e Bacillaceae, foram os principais grupos responsáveis por a especificidade do intestino de abelhas, enquanto as principais famílias responsáveis pela especificidade do pão de mel foram Neisseriaceae, Flavobacteriaceae, Acetobacteraceae e Lactobacillaceae. Em termos da estrutura da comunidade microbiana, a análise mostrou que as comunidades dos dois ambientes foram bastante diferentes umas das outras, com apenas 7% dos táxons a nível de espécies compartilhados entre o sitema digestório de abelhas e o pão de mel. Os resultados indicaram a presença de um elevado nível de especialização e uma microbiota intestinal bem adaptada dentro de cada abelha e do pão de mel.A comunidade associada ao pão de mel, apresentou maior abundância relativa de genes relacionados com a degradação de aminoácidos, carboidratos, e o metabolismo lipídico, sugerindo que biodegradação do pólen ocorre predominantemente pela microbiota associada ao pão de mel. Estes resultados sugerem uma complexa e importante relação entre nutrição de abelhas e suas comunidades microbianas. / The microbiota and the functional genes actively involved in the process of breakdown and utilization of pollen grains in beebread and beeguts are not yet understood. The aim of this work was to assess the diversity and community structure of bacteria and archaea in Africanized honeybee guts and beebread as well as to predict the genes involved in the microbial bioprocessing of pollen using state of the art ‘post-light’ based sequencing technology. A total of 11 bacterial phyla were found within bee guts and 10 bacterial phyla were found within beebread. Although the phylum level comparison shows most phyla in common, a deeper phylogenetic analysis showed greater variation of taxonomic composition. The families Enterobacteriaceae, Ricketsiaceae, Spiroplasmataceae and Bacillaceae, were the main groups responsible for the specificity of the bee gut while the main families responsible for the specificity of the beebread were Neisseriaceae, Flavobacteriaceae, Acetobacteraceae and Lactobacillaceae. In terms of microbial community structure, the analysis showed that the communities from the two environments were quite different from each other with only 7 % of species-level taxa shared between beegut and beebread. The results indicated the presence of a highly specialized and well-adapted microbiota within each bee gut and beebread. The beebread community included a greater relative abundance of genes related to amino acid, carbohydrate, and lipid metabolism, suggesting that pollen biodegradation predominantly occurs in the beebread. These results suggests a complex and important relationship between honeybee nutrition and their microbial communities.
|
120 |
Τύχη και επίδραση ξενοβιοτικών ουσιών στην αναερόβια χώνευση υγρών αποβλήτων και ιλύος / Fate and effect of xenobiotic compounds on the anaerobic digestion processΦουντουλάκης, Μιχαήλ 24 June 2007 (has links)
Η ευρωπαϊκή ένωση αναγνωρίζοντας τα προβλήματα που προκαλούνται από την παρουσία ξενοβιοτικών ουσιών στην επεξεργασμενη ιλύ εκδίδει συγκεκριμένες οδηγίες σχετικά με την διάθεση της στο έδαφος. Φαρμακευτικές ουσίες ,LAS ,APE, PAE και PAHs συχνά απαντώνται σε σημαντικές ποσότητες στην ιλύ, πολλές από τις ουσίες είναι παρεμπόδιστες ενώ η επίδραση τους στην λειτουργία των αναερόβιων αντιδραστήρων είναι άγνωστη. Στην εργασία αυτή μελετήθηκε η επίδραση των ρυπαντών αυτών στην διεργασία της αναερόβιας χώνευσης καθώς και η βιοαποδόμηση τους κάτω από αναερόβιες συνθήκες. Η τριχλωζάνη και η οφλοξακίνη παρεμποδίζουν την διαδικασία τησ αναερόβιας χώνευσης αυξάνοντας τα επίπεδα της συγκέντρωσης του διαλυτού χαο. Επίσης ο διαιθυλ(2-εξυλ)φθαλικός εστέρας βιοαποδομείται μερικώς. / Problems related to agricultural recycling of sludge include the presence of pollutants including priority pollutants identified in the EU urban water directives. Pharmaceuticals,LAS ,APE, PAE and PAHs are often present in significant quantities in the sludge. many of these compounds are inhibitory, and the impact on digester performance in unknown. in this work we identify the impact of these pollutants on the anaerobic process. itself, as well as degradation of the target compounds triclosaw and ofloxacin seemed to inhibit the anaerobic digestion process, increasing the dissolved cod concentration rapidly. Dehp was partially degraded. the mass transferrate was rate limiting for functioned as a tank equalizing the concentration of the dehp troughout the solid particle.
|
Page generated in 0.0487 seconds