Dissertations / Theses on the topic 'Oxidative stress factors'
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Wong, Hoi-kin, and 黃凱健. "New factors that affect adrenomedullin expression." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/195971.
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Master of Philosophy
Goumenaki, Eleni. "Factors governing the sensitivity of lettuce to ozone-induced oxidative stress." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432760.
Full textPoljak, Anne Medical Sciences Faculty of Medicine UNSW. "Oxidative, inflammatory and vascular factors in Alzheimer's disease." Publisher:University of New South Wales. Medical Sciences, 2008. http://handle.unsw.edu.au/1959.4/41273.
Full textYuan, Jianfeng. "Effects of hyperbaric oxygen on oxidative stress, angiogenesis factors and endothelial cell injury." Thesis, University of Plymouth, 2007. http://hdl.handle.net/10026.1/2451.
Full textPerry, Leslie M. "Regulation of Alternative Sigma Factors During Oxidative and Ph Stresses in the Phototroph Rhodopseudomonas Palustris." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc700009/.
Full textMullan, B. A. "Factors influencing endothelial function and arterial pulse wave morphology : the role of oxidative stress." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398095.
Full textSarrafee, Sara. "ROLE OF THE PORPHYROMONAS GINGIVALIS ECF SIGMA FACTOR, SIGH, IN OXIDATIVE STRESS RESPONSE." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1804.
Full textHelmersson, Johanna. "Prostaglandins and Isoprostanes in Relation to Risk Factors for Atherosclerosis : Role of Inflammation and Oxidative Stress." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4803.
Full textTakahashi, Ken-ichi. "Humoral factors for oxidative stress and regulation of body weight in patients with Obstructive Sleep Apnea." Kyoto University, 2008. http://hdl.handle.net/2433/124218.
Full textNälsén, Cecilia. "Measurement and Evaluation of Antioxidant Status and Relation to Oxidative Stress in Humans." Doctoral thesis, Uppsala University, Clinical Nutrition Research, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6742.
Full textNumerous diseases are associated with reduced antioxidant defence and oxidative stress. The antioxidant defence includes dietary and endogenous antioxidants and involves complex interactions between them. The effects of dietary factors on antioxidant status and oxidative stress of healthy humans were investigated in the studies described in this thesis. Assays of plasma antioxidant capacity encompass interactions between various antioxidants. Although uric acid has an unclear function as an antioxidant, it is a major determinant of antioxidant capacity. We measured antioxidant capacity in the presence and absence of uric acid to provide more information on the application of measures of antioxidant capacity. Individuals with high dietary intakes of various antioxidants and antioxidant rich foods, especially when combined, had higher plasma antioxidant capacities than those with lower antioxidant intakes. However, there were no associations between dietary intake of antioxidants or antioxidant rich foods and the plasma concentration of F2-isoprostanes, which is considered a reliable biomarker for oxidative stress. Intakes of various doses of a mixture of bilberry juice and black tea, rich in flavonoids for four weeks, increased antioxidant capacity in some groups, but urine levels of F2-isoprostanes were not affected. There were substantial individual variations in responses to the drinks related to baseline antioxidant capacity. Supplementation with eicosapentaenoic acid and docosahexaenoic acid decreased the plasma levels of F2-isoprostanes, but not prostaglandin F2α formation or antioxidant capacity.
It was concluded that a high intake of foods rich in antioxidants is related to improved antioxidant status. After intake of foods rich in antioxidants, the antioxidant status may increase, but with considerable individual variation in the responses, which warrants further investigation. Lipid peroxidation in vivo is not easily affected by dietary antioxidants in healthy humans. Although n-3 fatty acids are highly unsaturated, they reduce nonenzymatic free radical-catalyzed lipid peroxidation, but not enzymatic lipid peroxidation.
Leung, Man-hong, and 梁文康. "Investigating the role of the forkhead box transcription factor FOXM1 against oxidative stress and DNA damage in human embryonic stem cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2015. http://hdl.handle.net/10722/208595.
Full textTaqi, Aboubakr Mohamed Omar [Verfasser]. "Transcription factors mediated oxidative stress response in bovine follicular cells and preimplantation embryos / Mohamed Omar Taqi Aboubakr." Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1224966139/34.
Full textSingh, Sukhvinder Pal. "Postharvest oxidative stress in plums : mechanism and implications for storage and fruit quality." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/551.
Full textCastillo, Andreo Esther. "Regulación por estrés oxidativo de la actividad del factor de transcripción Pap1 de Schizosaccharomyces pombe." Doctoral thesis, Universitat Pompeu Fabra, 2005. http://hdl.handle.net/10803/7089.
Full textLa levadura Schizosaccharomyces pombe es un organismo modelo ideal para el estudio de las respuestas a estrés oxidativo en las células eucariotas ya que posee sensores específicos a estrés oxidativo como el factor de transcripción Pap1 (pombe AP-1-like) y rutas de respuesta global a estrés, como las descritas en las células de mamífero, que son activadas por diferentes tipos de estrés. En el centro de esta ruta de respuesta global a estrés se encuentra la MAPK (Mitogen-activated protein kinase) Sty1.
El factor de transcripción Pap1, de localización citoplasmática basal, se acumula en el núcleo en respuesta a estrés oxidativo. Este cambio de localización subcelular es debido a la inhibición del exporte nuclear dependiente de Crm1, aunque se desconocía el mecanismo molecular utilizado por este factor de transcripción para sensar y responder a oxidantes como H2O2 y dietilmaleto (DEM). Los resultados obtenidos indican que H2O2 oxida de forma reversible dos residuos de cisteína de Pap1 induciendo, seguramente, la formación de un puente disulfuro intramolecular, mientras que, DEM actúa como un agente alquilante que modifica de forma irreversible los residuos de cisteína del dominio C-terminal de Pap1.
El gen que codifica para el factor de transcripción Pap1 fue aislado inicialmente como un gen que, en elevado número de copias, confería a las células un fenotipo de resistencia a ciertas drogas como estaurosporina. Esto es debido a que, tras acumularse en el núcleo en respuesta a estrés oxidativo, Pap1 activa la transcripción de genes implicados tanto en la respuesta antioxidante como en la resistencia a multidrogas. Todos aquellos genes que, al igual que pap1 fueron identificados por su implicación en la resistencia a multidrogas, codifican para proteínas que regulan la actividad del factor de transcripción Pap1. hba1 fue el único gen relacionado con resistencia a multidrogas, cuyo producto génico, una proteína con un dominio de unión a Ran (Ran-binding domain), Hba1, no había sido relacionado con la actividad de Pap1. Uno de los objetivos de mi trabajo experimental era el de determinar si Hba1 tenía un papel en la regulación de la actividad de Pap1.
Nuestros resultados indican que la proteína Hba1, localizada en el nucleoplasma de la célula, participa en el exporte nuclear mediado por Crm1 de ciertas proteínas como el factor de transcripción Pap1 y la MAPK Sty1, aunque no de otras como la proteína PKI. Por ello, la pérdida de función de Hba1, por sobreexpresión o deleción del gen hba1, induce la localización nuclear constitutiva de Pap1 y Sty1 en ausencia de estrés. Esta localización nuclear de Pap1 es suficiente para la activación transcripcional de sus genes diana. Por lo tanto, el fenotipo de resistencia aumentada a multidrogas de las cepas en las que se ha perdido la actividad de la proteína Hba1, es debido a la acumulación de Pap1 en el núcleo en condiciones de no-estrés.
Medlow, Paul Wallace. "The effects of aerobic exercise on oxidative stress and cardiovascular risk factors in aging and type II diabetes mellitus." Thesis, University of Ulster, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601214.
Full textMistry, Hiten. "Selenium, selenoproteins and factors which might interact with them relating to oxidative stress, in normal and pre-eclamptic pregnancies." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491024.
Full textSingh, Indu, and indu singh@rmit edu au. "The influence of antioxidants on thrombotic risk factors in healthy population." RMIT University. Medical Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081205.121719.
Full textWang, Zhenchao. "Role of Oxidative Stress, Growth Factors and Apoptosis in Diabetic Nephropathy and Regulation of Preoptic Area Regulatory Factor-2 Expression by Insulin/IGF-1." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1305040037.
Full textAlkazemi, Dalal Usamah Zaid. "Modulating factors of serum oxysterol concentrations in daughters from gestational diabetes and non-gestational diabetes." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100757.
Full textLe diabète pré-gestationnel et le diabète de gestation (DG) augmentent le risque dedéveloppement d'une future résistance à l'insuline et de diabète de type 2 autant pourla mère que pour l'enfant. Le stress oxydatif est un facteur potentiel impliqué dans ledéséquilibre du glucose sanguin associé au diabète de type 2 et au syndromemétabolique. La présente thèse est une étude sectionnelle croisée, ayant pour but demesurer des marqueurs du stress oxidatif, notamment la concentration des oxystérolsgénérés par les radicaux libres dans le sérum d'adolescentes, nées de mères ayantprésenté ou non un diabète de gestation. Nos résultats montrent des concentrationsd'oxystérols (7P-hydroxycholesterol) plus élevées dans le sérum de filles issues degestations diabétiques à comparer aux filles de mères n'ayant pas eu de DG.Cependant, la différence entre les deux groupes n'était pas statistiquementsignificative après un ajustement au cholestérol total. La concentration d'oxystérolsétait significativement corrélée aux marqueurs d'obésité, notamment la circonférencede la taille et l'index de masse corporelle, possiblement à l'origine de la tendance desoxystérols à être plus élevés dans le cas des adolescentes issues de gestationsdiabétiques.
Rytter, Elisabet. "Effect of Dietary Antioxidants on Oxidative Stress, Inflammation and Metabolic Factors : Studies in Subjects with Overweight and with Type 2 Diabetes." Doctoral thesis, Uppsala universitet, Oxidativ stress och inflammation, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-134938.
Full textYu, Xin. "STUDIES OF FACTORS AFFECTING INTRACELLULAR TOXICITY OF THE SCA7 DISEASE PROTEIN ATAXIN - 7 : FOCUS ON ATAXIN-7 DEGRADATION AND OXIDATIVE STRESS." Licentiate thesis, Stockholms universitet, Institutionen för neurokemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-64167.
Full textAt the time of defence the following paper was unpublished and had a status as follows: Paper 2: Manuscript
Svensson, Michael B. "Endogenous antioxidants in human skeletal muscle and adaptation in energy metabolism : with reference to exercise-training, exercise-related factors and nutrition /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-433-X.
Full textChan, Kevin Ki Fai. "Factors influencing arbovirus transmission: vector competence and the effects of virus infection on repellent response, oxidative stress, and glutathione-S-transferase activity." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/104393.
Full textDoctor of Philosophy
Zika (ZIKV), La Crosse (LACV), and Cache Valley (CVV) viruses are transmitted by mosquitoes and can make humans and animals very sick. There are many biological factors that determine if a mosquito can transmit a virus and these viruses can change the biology of a mosquito. We conducted laboratory studies to see if Aedes and Culex mosquitoes can transmit ZIKV and CVV. We found that all Aedes mosquitoes were able to transmit CVV and only the Asian tiger mosquito and Asian rock pool mosquito were able to transmit ZIKV. Mosquitoes infected with high amounts of CVV developed higher transmission rates. We also found that transmission of ZIKV was limited by barriers in the mosquito midgut and salivary glands. Second, we looked at the effects of LACV and ZIKV infection on how Aedes mosquitoes respond to repellents and found that infected mosquitoes were less sensitive to low concentrations of DEET, picaridin, and PMD. Increasing concentrations of the repellents to 10% or higher was able to provide adequate protection against infected and uninfected mosquitoes. Lastly, we determined the effects of ZIKV and LACV infection on oxidative stress and glutathione-S-transferase (GST) activity in the Asian tiger mosquito. Virus infection did not change oxidative stress, but GST activity was higher in infected mosquitoes tested after 3 days after infection. We found that oxidative stress decreased and GST activity increased over the 10-day test period. This indicates that GSTs may help control damaging products from oxidative stress. The results from this entire study identified what mosquitoes were able to transmit emerging mosquito-borne viruses and demonstrated the biological effects of virus infection in the mosquitoes.
Gumpper, Kristyn Nicole. "Maintaining Cardiac and Gastric Physiology: TRIM Proteins as Central Factors in Regulation of Organ Homeostasis at the Cellular Level." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563287863754715.
Full textLee, Bo Young. "Signaling events in activity dependent neuroprotection, neurodegeneration, and synaptic plasticity." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1180458484.
Full textMiralles, Pérez Bernat. "Effects of Fish Oil and its Combination with Grape Seed Polyphenols or Buckwheat D-Fagomine on Cardiometabolic Risk Factors and Oxidative Stress in Rats." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672213.
Full textEn las últimas décadas, las prevalencias de obesidad, de dislipidemia aterogénica y de síndrome metabólico han aumentado a nivel mundial. La resistencia a la insulina es una característica común en estos trastornos cardiometabólicos. La patogenia de la resistencia a la insulina está claramente relacionada con el estrés oxidativo, la inflamación y la acumulación de lípidos bioactivos como los diacilgliceroles y las ceramidas. Los ácidos grasos poliinsaturados ω-3 (AGPI ω-3) presentes en el aceite de pescado, el ácido eicosapentaenoico (EPA) y el ácido docosahexaenoico (DHA), están asociados a un menor riesgo de desarrollar trastornos cardiometabólicos. Sin embargo, cuando se administra en dosis excesivas, el DHA puede provocar efectos perjudiciales para la salud. La combinación de compuestos bioactivos puede ser una estrategia preventiva para proteger contra la aparición de trastornos cardiometabólicos. El objetivo de este trabajo es evaluar los efectos del aceite de pescado y su combinación con polifenoles de semillas de uva o D-fagomina del trigo sarraceno sobre los factores de riesgo cardiometabólico y el estrés oxidativo en ratas sanas y en ratas alimentadas con una dieta rica en grasas. La suplementación con el aceite de pescado rico en DHA mejora varios factores de riesgo cardiometabólico, pero aumenta el daño oxidativo de las biomoléculas en ratas sanas. La suplementación combinada con el aceite de pescado con una proporción EPA/DHA 1:1 y los polifenoles de semillas de uva tiende a reducir el estrés oxidativo y modula significativamente el contenido de lípidos bioactivos en el hígado de ratas alimentadas con una dieta alta en grasas. La suplementación combinada con el aceite de pescado con una proporción EPA/DHA 1:1 y la D-fagomina del trigo sarraceno tiene efectos beneficiosos sobre el estrés oxidativo y sobre algunos factores de riesgo cardiometabólico en ratas alimentadas con una dieta rica en grasas. Aumentar la ingesta dietética de AGPI ω-3 mediante suplementos de aceite de pescado con una proporción EPA/DHA 1:1, de forma individual o combinada con los polifenoles o la D-fagomina, puede ser una estrategia nutricional útil para proteger contra los mecanismos implicados en el desarrollo de trastornos cardiometabólicos en individuos sanos y en individuos con un alto riesgo de enfermedad.
The past few decades have seen an alarming increase in the worldwide prevalence of obesity, atherogenic dyslipidemia, and metabolic syndrome. Insulin resistance is a common characteristic in these cardiometabolic disorders. The pathogenesis of insulin resistance is clearly related to oxidative stress, inflammation as well as accumulation of bioactive lipids such as diacylglycerols and ceramides. The ω-3 polyunsaturated fatty acids (ω-3 PUFA) from fish oil, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with lower risk for developing cardiometabolic disorders. Nevertheless, when provided in excess, DHA may lead to deleterious effects on health. Combining bioactive compounds may be a powerful preventive strategy to protect against the onset of cardiometabolic disorders. The aim of the present work is to explore the influence of fish oil and its combination with grape seed polyphenols or buckwheat D-fagomine on cardiometabolic risk factors and oxidative stress in healthy rats and in rats fed a high fat diet. The supplementation with the fish oil rich in DHA beneficially affects several cardiometabolic risk factors, but increases oxidative damage to biomolecules in healthy rats. The combined supplementation with fish oil containing EPA/DHA 1:1 and grape seed polyphenols tends to attenuate oxidative stress, and significantly modulates abundances of bioactive lipids in the liver of rats fed a high fat diet. The combined supplementation with fish oil containing EPA/DHA 1:1 and buckwheat D-fagomine exerts beneficial influence on oxidative stress and on some related cardiometabolic risk factors in rats fed a high fat diet. The increase in dietary intake of ω-3 PUFA from fish oil supplements containing EPA/DHA 1:1, alone or combined with polyphenols or D-fagomine, may be a useful nutritional strategy to protect against the mechanisms underlying the onset of cardiometabolic disorders in healthy individuals and in individuals at high risk of disease.
Chung, Wai Shing. "Investigation on the correlation between redox changes and oxidative stress in diabetes, and their role in transcription factors activation in vitro and in vivo." HKBU Institutional Repository, 2002. http://repository.hkbu.edu.hk/etd_ra/428.
Full textRowe, Derrick. "Secreted Factors from Human Umbilical Cord Blood Cells Protect Oligodendrocytes from Ischemic Insult." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3323.
Full textFitsanakis, Vanessa A., Kimberly N. Thompson, Sarah E. Deery, Dejan Milatovic, Zak K. Shihabi, Keith M. Erikson, Russell W. Brown, and Michael Aschner. "A Chronic Iron-Deficient/High-Manganese Diet in Rodents Results in Increased Brain Oxidative Stress and Behavioral Deficits in the Morris Water Maze." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etsu-works/6346.
Full textKegler, Aline. "NEUROINFLAMAÇÃO E VIA APOPTÓTICA NA EPILEPSIA." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/11251.
Full textEpilepsy is a neurological disease that affects around 1% of world population, with neurobiological, neurochemical, cognitive and psychological consequences. Despite the good prognosis, the high number of epilepsy patients who have refractory seizures to medicine, reflects lack of a better understanding about excitotoxic disorders characteristic of the disease. So, the aim of the study was to investigate if there is an association between apoptotic markers and inflammation pathway in epileptic subjects and those without the disease. Blood samples were collected from subjects with epilepsy and were measured protein carbonyl, tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-لا), acetylcholinesterase (AChE), caspases (CASP8 and CASP3) and picogreen (PG). The results showed an increase in all analyzed biochemistry parameters from epilepsy subjects when compared to healthy, suggesting that there is a relation between this disease with apoptotic and inflammatory markers. Furthermore, there was a positive correlation between TNF-α with CASP 8 and 3. IFN-لا was just correlated with caspase 3. The correlation between analyzed parameters with seizure severity and antiepileptic drugs (AEDs) treatment was not significant, indicating that medicine administration and symptoms improve did not influence obtained results. So, our results suggest that epileptic seizures can induce the creation of a vicious circle between neuroinflammation and cell death, resulting in DNA damage in epilepsy patients. Furthermore, we suggest that AEDs acting in TNF-α or IFN-لا pathway could represent an adjunctive therapy in epilepsy patients treatment.
A epilepsia é uma doença neurológica que afeta em torno de 1% da população mundial, tendo consequências no âmbito neurobiológico, neuroquímico, cognitivo e psicológico. Apesar do bom prognóstico, o elevado número de pacientes com epilepsia, que apresentam convulsões refratárias aos medicamentos, reflete a falta de um melhor entendimento dos distúrbios excitotóxicos característicos desta doença. A partir disto, o objetivo deste estudo foi investigar se existe uma associação entre os marcadores apoptóticos e a via inflamatória em indivíduos epilépticos e naqueles sem a doença. Amostras de sangue foram coletadas de pacientes com epilepsia e posteriormente foram analisados os níveis de proteína carbonil, fator de necrose tumoral alfa (TNF-α), interferon gama (INF-لا), acetilcolinesterase (AChE), caspases (CASP8 e CASP3) e picogreen (PG). Os resultados mostraram um aumento em todos os parâmetros bioquímicos analisados no sangue de pacientes com epilepsia quando comparado aos controles. Além disso, foi observada uma correlação positiva entre TNF-α com as caspases (8 e 3). O IFN-لا correlacionou-se apenas com os níveis da caspase 3. A correlação entre os parâmetros analisados com a gravidade das crises epilépticas e o tratamento com fármacos antiepilépticos (FAEs) não foi significativa, indicando que a administração de medicamentos para controle das crises e melhora dos sintomas não influenciou nos resultados obtidos. Dessa forma, os nossos dados sugerem que as crises epilépticas podem induzir a geração de um ciclo vicioso entre neuroinflamação e apoptose celular, induzindo ao estresse oxidativo e resultando no dano ao DNA nos pacientes com epilepsia. Além disso, nós sugerimos que o uso de FAEs que atuem na via do TNF-α ou IFN-لا poderia representar uma terapia complementar no tratamento dos pacientes epilépticos.
Koskenkorva, Taija Susanna. "Insights into the function of Pseudomonas aeruginosa flavohemoglobin : identification of regulatory factors and their roles in the transcription of fhp during nitrosative and oxidative stress /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17211.
Full textMöllsten, Anna. "Factors influencing the risk of diabetic nephropathy : analyses of genes, smoking and diet." Doctoral thesis, Umeå universitet, Pediatrik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-911.
Full textPermuth, Wey Jennifer. "Evaluation of Common Inherited Variants in Mitochondrial-Related and MicroRNA-Related Genes as Novel Risk Factors for Ovarian Cancer." Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3488.
Full textMello, Maristela Previato. "Caracterização funcional de fatores de transcrição da família MarR de Chromobacterium violaceum." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17136/tde-13092018-104909/.
Full textTranscription factors belonging to the MarR family act as direct intracellular sensors of signals and control many processes in bacteria, including virulence and degradation of aromatic compounds. In this work, we identify and characterize MarR family transcription factors controlling virulence in Chromobacterium violaceum, an opportunistic pathogen of humans. Using allelic exchange mutagenesis, we generate non-polar null mutants for twelve of the fifteen MarR family regulators found in the C. violaceum genome. In virulence tests, when introduced by intraperitoneal injection in BALB/c mice, the ?CV_0210 (?ohrR), ?CV_0577 and ?CV_2726 mutant strains were less virulent, while the ?CV_1776 was more virulent, when compared to the wild-type strain. The other nine MarR mutants showed no difference in virulence tests. To define the regulon of some MarR family transcription factors, the gene expression profiles were determined by DNA microarray analysis and Northern blot assays for the ?CV_0210 (?ohrR), ?CV_1776, ?CV_1810 and ?CV_2726 mutant strains, for the wild-type strain overexpressing CV_2726 and for the wild-type strain exposed to oxidative stress generated by cumene hydroperoxide (CHP). The CV_1810 is a repressor of a regulon that comprised two divergent operons encoding enzymes that possibly metabolize aromatic compounds, but catabolic products of these compounds did not function as ligands capable of antagonizing the repression of CV_1810 on the CV_1801 gene. The regulon of the activator CV_2726, defined as fourteen differentially expressed genes commonly found in assays in the absence and overexpression of the CV_2726 gene, revealed few genes (cstA) with potential to be involved in the phenotype of lower virulence of the ?CV_2726 mutant strain. Regulators CV_0577 and CV_1776 were allocated in the urate-responsive UrtR subfamily and probably afect the virulence of C. violaceum with overlapping regulons. The CV_1776 regulon contains dozens of genes, many of them related to amino acid catabolism, but there are few candidates for classical virulence factors (pecM, escU). Some genes related to catabolism/utilization of purine (CV_0578 and CV_3771) were 12 regulated by both CV_1776 and CV_0577 and responded to the presence of urate. The transcriptional profile of the adaptive response of C. violaceum to CHP, a ligand that oxidizes the OhrR regulator, revealed the upregulation of genes related to the detoxification of peroxides (antioxidant enzymes and thiol-reducing systems), degradation of the aromatic moiety of CHP (oxygenases), and protection against other secondary stresses (DNA repair, heat shock, iron limitation, and nitrogen starvation responses). The OhrR regulon was shown to be small, including two upregulated genes, CV_0209 (ohrA) and CV_0208 (putative diguanylate cyclase), and three downregulated genes (hemolysin, chitinase, and collagenase) in the ?ohrR mutant. Thus, the attenuated virulence of the ?ohrR mutant might be related to the increased production of the second messenger cyclic di-GMP (c-di-GMP) and the decreased expression of extracellular enzymes required for tissue dissemination, in this mutant strain. In conclusion, we have defined the transcriptional response to CHP, identified potential virulence factors such as diguanylate cyclase as members of the OhrR regulon, and shown that C. violaceum uses the transcription factors of the MarR family CV_0577, CV_1776, CV_2726 and OhrR to modulate its virulence.
Silva, Ana Luísa Patrício. "Impact of natural and/or chemical stressors on the freeze-tolerant and euryhaline enchytraeid, Enchytraeus albidus." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/16009.
Full textRapid climatic changes are taking place in Arctic, subarctic and cold temperate regions, where predictions point to an increase in freeze-thaw events, changes in precipitation, evaporation and salinity patterns. Climate change may therefore result in large impacts in ecosystem functioning and dynamics, especially in the presence of contaminants due to intense anthropogenic activities. Even though multiple stress approaches have received increasing interest in the last decades, the number of such studies is limited. In particular, knowledge on the effect of freezethaw events and salinity fluctuations on ecotoxicology of soil invertebrates is lacking, especially important when considering supralittoral species. Therefore, the aim of this thesis was to investigate the effects of low temperature and salinity fluctuations, singly and in combination with contaminants, in the freeze-tolerant and euryhaline enchytraeid Enchytraeus albidus. The assessment of population level endpoints (survival and reproduction), along with physiological and biochemical parameters such as levels of cryoprotectants, ice/water content, oxidative stress biomarkers, cellular energy allocation, and tissue concentration of chemicals (when applied), provided new and valuable knowledge on the effects of selected physical and chemical stressors in E. albidus, and allowed the understanding of adjustments in the primary response mechanisms that enable worms to maintain homeostasis and survival in harsh environments such as polar and temperate-cold regions. The presence of moderate levels of salinity significantly increased freeze-tolerance (mainly evaluated as survival, cryoprotection and ice fraction) and reproduction of E. albidus. Moreover, it contributed to the readjustments of cryoprotectant levels, restoration of antioxidant levels and changed singnificantly the effect and uptake of chemicals (copper cadmium, carbendazim and 4-nonylphenol). Temperature fluctuations (simulated as daily freeze-thaw cycles, between -2ºC and -4ºC) caused substancial negative effect on survival of worms previsouly exposed to non-lethal concentrations of 4-nonylphenol, as compared with constant freezing (-4ºC) and control temperature (2ºC). The decrease in cryoprotectants, increase in energy consumption and the highest concentration of 4-nonylphenol in the tissues have highlighted the high energy requirements and level of toxicity experienced by worms exposed to the combined effect of contaminants and freezing-thawing events. The findings reported on this thesis demonstrate that natural (physical) and chemical stressors, singly or in combination, may alter the dynamics of E. albidus, affecting not only their survival and reproduction (and consequent presence/distribution) but also their physiological and biochemical adaptations. These alterations may lead to severe consequences for the functioning of the ecosystems along the Arctic, subarctic and cold temperate regions, where they play an important role for decomposition of dead organic matter. This thesis provides a scientific basis for improving the setting of safety factors for natural soil ecosystems, and to underline the integration of similar investigations in ecotoxicology, and eventually in risk assessment of contaminants.
As alterações climáticas estão a atingir rapidamente as regiões do Ártico, SubÁrtico e as regiões temperadas, apontando as previsões para um aumento de eventos de congelamento-descongelamento, bem como mudanças nos padrões de precipitação, evaporação e de salinidade. Estas alterações climáticas poderão resultar em impactos francamente negativos no funcionamento e dinâmica de ecossistemas, especialmente quando associados à presença de contaminantes resultantes da intensa atividade antropogénica. Embora a incorporação de stressores múltiplos em estudos de ecotoxicidade tenha recebido um crescente interesse pela comunidade científica, o seu número é ainda reduzido. Particularizando, o conhecimento dos efeitos de eventos de congelamento-descongelamento e de flutuações de salinidade permanecem desconhecidos, especialmente quando se consideram espécies supra-litorais. Neste contexto, o objetivo geral da presente tese consistiu em investigar os efeitos das flutuações de temperaturas e salinidade, individualmente ou em combinação com contaminantes, no enquitraídeo tolerante ao frio e eurialino - o Enchytraeus albidus. A avaliação de parâmetros populacionais (sobrevivência, reprodução e bioacumulação), fisiológicos (níveis de crioprotetores, conteúdo em gelo / água, temperatura de fusão e sobrecongelamento) e bioquímicos (biomarcadores de stress oxidativo, alocação de energia celular) permitiu compilar novas e valiosas informações sobre os efeitos dos stressores físicos e químicos selecionados no enquitraídeo e compreender quais os reajustes nos mecanismos de resposta primários que lhes permitem manter a homeostasia e sobrevivência em ambientes inóspitos como as regiões Polares e temperadas-frias. A presença de níveis moderados de salinidade aumentou significativamente a tolerância a temperaturas congelantes (essencialmente avaliada como sobrevivência, crioprotecção e fracção de gelo extracelular) e a reprodução do E. albidus. Além disso, contribuiu para a regulação de crioprotectores, restauração dos níveis de antioxidantes nestes organismos e alterou significativamente o efeito e a incorporação/absorção de substâncias químicas (cádmio, cobre carbendazim e 4-nonilfenol). As flutuações de temperatura (simuladas como ciclos diários de congelamento-descongelamento, com temperaturas entre 2ºC e -4ºC) causaram um efeito substancialmente negativo na sobrevivência de organismos previamente expostos a concentrações não letais de 4-nonilfenol, quando comparados com organismos expostos a uma temperatura congelante constante (-4ºC) ou à temperatura controlo (2ºC). A diminuição na crioproteção, o aumento no consumo de energia e a maior concentração de 4-nonilfenol nos tecidos vieram sublinhar o elevado gasto energético e o nível de toxicidade sofrido pelos organismos expostos à combinação de contaminantes e eventos de congelamento e descongelamento. Os resultados apresentados nesta tese demonstram, assim, que a presença de stressores naturais (físicos) e químicos, isoladamente ou em combinação, podem alterar a dinâmica do E. albidus, afetando não só a sua sobrevivência e reprodução (e consequente presença / distribuição), mas também as suas adaptações fisiológicas e bioquímicas. Essas alterações podem levar a consequências graves para o funcionamento dos ecossistemas do Ártico, subÁrtico e regiões temperadas-frias, uma vez que estes organismos desempenham um papel importante para a decomposição de matéria orgânica morta. Esta tese fornece ainda uma base científica para melhorar a atribuição de coeficientes de segurança para os ecossistemas naturais do solo, alertando para a integração de investigações semelhantes em ecotoxicologia, e, eventualmente, para a avaliação de risco ecológico de contaminantes.
Liu, Beiqing. "Distinct regulation of early gene transactivation and IL-2 gene expression by sublethal levels of oxidative stress in activated human T lymphocytes: Involvement of intracellular signaling pathways and transcription factors /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487945015617244.
Full textVanzella, Cláudia. "Efeitos do exercício físico sobre a memória e sobre parâmetros bioquímicos e moleculares no hipocampo e no músculo de ratos senescentes." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/158166.
Full textAging is a process in which structural and functional changes occur in most organs and may lead to increased susceptibility to various age-related diseases. Several approaches have been investigated with the aim of reducing age-related symptoms and physical exercise is a therapeutic strategy that has presented neuroprotective action in different experimental models. In this context, some studies show that regular physical exercise is related to the improvement of quality of life and to the prevention of age-related cognitive decline. In the present thesis, we investigated the effect of moderate physical exercise on memory and on biochemical parameters in the hippocampus and soleus muscle in 3, 6 and 22 months-old rats. For that, three different experiments were carried out, which gave rise to the three chapters presented in this thesis. In the first experiment, we studied the effect of physical exercise in 3 and 22 months-old rats. In this experiment, the exercise prevented the age-related acquisition deficit of reference memory. In addition, exercise prevented the increased in oxidative stress and also was able to increase the expression of neurotrophic factors BDNF, NT-3 and IGF-1 in the hippocampus of aged rats. It is important to note that there was a positive correlation between the reduction of oxidative stress and latency to find the platform on the 5th day of training in the reference memory task, i.e., reduction of reactive species levels and lipid peroxidation, might be associated with the exercise-related memory improvement. In the second experiment, we evaluated the effect of physical exercise in 3, 6 and 22 months-old rats. Corroborating with the results presented in the previous experiment, it was demonstrated that moderate physical exercise prevented age-related spatial reference and working memory deficits. It has also been shown that the cognitive training in Water maze increased the activity of the Na+,K+-ATPase and AChE enzymes in the hippocampus of adult and aged rats. The increase in Na+,K+-ATPase activity was even further increased in aged rats that were submitted to physical exercise combined with cognitive training. In addition, a positive correlation was observed between the Na+,K+-ATPase activity in the hippocampus of aged exercised rats and the latency to find the platform on the 5th day of training in the reference memory task, i.e., the increase in Na+,K+-ATPase activity is associated with the exercise-related memory improvement in aged rats. Consistently, a negative correlation between the Na+,K+-ATPase activity and the difference (delta) between the mean latencies of trials 1 and 4 in the working memory task was also found, i.e., the exercised aged rats showed better performance in the working memory task associated with the increase in Na+,K+-ATPase activity. In the third experiment, we investigated the effect of physical exercise in 3 and 22 months-old rats. Exercise increased the reactive species content and lipid peroxidation in soleus muscle of young rats. Aged rats showed an increase in lipid peroxidation and a reduction in the catalase activity. Exercise induced an increase in reactive species levels, a reduction in sulfhydryl content and an increase in carbonyl proteins; however, the exercise was able to increase the superoxide dismutase and catalase activities in the soleus of aged rats. Thus, the results of first and second experiments demonstrate that physical exercise prevents the age-related decline of spatial memory and this effect might be related to the reduction of oxidative stress, increased expression of neurotrophic factors and the increase in the Na+,K+-ATPase activity in the hippocampus of aged rats. The muscle results demonstrate that soleus of young rats, although susceptible to the increased in reactive species and lipid peroxidation, showed no damage to proteins, suggesting that other mechanisms, such as the non-enzymatic antioxidant defense system, may be acting to compensate the effects of exercise. In addition, the muscle of the aged rats seems to be more sensitive than the young rats to changes in the cellular oxidative state induced by exercise, since aged exercised animals showed an increase in the activity of antioxidant enzymes, but there was no reduction of oxidative damage.
Juvany, Cánovas Marta. "Edat cronològica, edat fisiològica i sexe: factors determinants de l'estrès oxidatiu en plantes." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/283933.
Full textMetabolic processes in plants such as photosynthesis, photorespiration and respiration, produce reactive oxygen species (ROS). ROS are highly toxic molecules but besides of its damaging nature they are implicated in cell signaling in different cellular processes. However, under stress conditions plants can suffer an increase of ROS levels. When ROS concentration becomes high enough to overwhelm antioxidant systems, plant suffer oxidative stress as a consequence of the unbalanced cellular redox status. Despite the importance to unravel plant stress responses, little is known about the mechanisms implicated in perennial plants. Furthermore, the possible effect of plant intrinsic factors, as plant age or reproductive effort, in oxidative stress levels is still poorly understood. The main objective of this thesis was to determine how plant age, both chronological and physiological, as well as reproductive effort may influence oxidative stress levels in perennial plants. With this purpose levels of antioxidants as carotenoids, anthocyanins and alpha-tocopherol together with endogenous contents of stress hormones were measured, but with special emphasis in malondialdehyde acid levels, a byproduct of lipid peroxidation. To better understand the plant age effect we used leaves and juvenile plants of Pistacia lentiscus as well as moribund beech trees. Increases in lipid peroxidation not only could mean an oxidative damage but play a signaling role. Therefore, chronolorgical age concomitantly with the measure of oxidative stress levels is a good indicator of plant physiological age. Sex-related changes in photoprotection mechanisms between female and male plants of Pistacia lentiscus, a dioecious plant, where observed under climatological adverse conditions. Although females phowed higher oxidative stress levels compared to males, females were not affected negatively, suggesting a role in signaling. In addition, photoprotection capacity was higher in reproductive shoots relative to non-reproductive shoots in females, thus suggesting that females prioritized protection to fruit-bearing shoots.
Ingelsson, Erik. "Insulin Resistance and Inflammation as Risk Factors for Congestive Heart Failure." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5879.
Full textTomás, Mestres Marta. "Factors genètics i ambientals i les seves interaccions com a determinants de l'efecte protector de la paraoxanasa1 en la malaltia cardiovascular." Doctoral thesis, Universitat Pompeu Fabra, 2003. http://hdl.handle.net/10803/7067.
Full textParaules claus: paraoxonasa, PON1, genotips, simvastatina, hipercolesterolèmia familiar, interacció gen-dieta, lipoproteïna d'alta densitat (HDL), exercici físic agut, entrenament físic, estrès oxidatiu, àcid oleic, oli d'oliva, peròxids lipídics, malaltia cardiovascular.
The present thesis evaluates some environmental factor effects on paraoxonase1 (PON1), an possibly protective against cardiovascular disease antioxidant enzyme, through two intervention studies and a cross-sectional one. First, treatment with simvastatin of the familial hypercholesterolemic patients, which had low paraoxonase activity, was associated with an increase in the activity to values similar to the normolipemic ones, regardless of the PON1-55 or PON1-192 polymorphisms. Second, Regular exercise was associated with an increase in PON1 activity in QQ subjects and with a decrease in R carriers. Increased PON1 activity immediately after a bout of exercise was subsequently followed by a decrease of activity. The recovery of the basal PON1 activity levels at 24 h was found in QQ subjects regardless of their training status and in trained R carriers, but not in untrained R carriers.
Third, high oleic acid intake was associated with increased HDL cholesterol and PON1 activity levels only in men who were QR and RR of the PON1-192 polymorphism, respectively.
Pasanen, A. K. (Anna Kaisa). "A translational study on the roles of redox molecules, cell cycle regulators and chemokine receptors as prognostic factors in diffuse large B-cell lymphoma." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526202624.
Full textTiivistelmä Lymfoomat ovat yli 70 erilaisen maligniteetin muodostama ryhmä imukudoksen syöpiä, ja diffuusi suurisoluinen B-solulymfooma (engl. DLBCL) on yleisin lymfoomatyyppi. Yli 70 prosenttia DLBCL-potilaista pystytään parantamaan nykyaikaisilla hoidoilla, mutta osa potilaista kuolee edelleen tautiin. Nämä potilaat tarvitsisivat tehokkaampia hoitoja vakavien haittavaikutusten riskistä huolimatta, mutta huonon ennusteen potilaiden tunnistaminen etukäteen on vaikeaa. Tutkimuksen tavoitteena oli löytää biologisia tekijöitä DLBCL-potilaiden hoitovasteen ja taudin keskushermostossa (engl. CNS) uusiutumisen ennustamiseen. Aineisto sisältää 263 lymfoomapotilasta. 205 potilaalla on DLBCL, ja 37:llä näistä primaari aivolymfooma (PCNSL). Immunohistokemiallisilla värjäyksillä määritettiin oksidatiivisen stressin markkereiden 8-hydroksideoksiguanosiinin (8-OHdG) ja nitrotyrosiinin, sekä antioksidanttientsyymien mangaanisuperoksidi-dismutaasin (MnSOD), tioredoksiinin (Trx) ja gammakysteiiniligaasin (GCL) ilmentyminen reaktiivista imukudosta sekä B-soluperäisiä lymfoomia edustavissa näytteissä. DLBCL-näytteistä määritettiin lisäksi solusykliä säätelevien proteiinien p16, p53, p21 ja p27 sekä kemokiinireseptorien CXCR4, CXCR5 ja CCR7 ilmentyminen. Lisäksi reaktiivista imukudosta, imusolmuke-DLBCL:aa, sekundaarista CNS-lymfoomaa ja PCNSL:aa edustavista näytteistä määritettiin immunoelektronimikroskooppisesti reseptorien CXCR4 ja CXCR5 sekä ligandien CXCL12 ja CXCL13 ilmentyminen. Tulosten mukaan voimakas nitrotyrosiini-, Trx- ja GCL-positiivisuus ovat yhteydessä huonoon ennusteeseen. Solusyklin säätelyhäiriön vaikeusastetta kuvaava ennusteellinen pisteytys jaotteli DLBCL-potilaat kolmeen ennusteelliseen ryhmään. Runsas sytoplasminen CXCR5-positiivisuus oli yhteydessä CNS-tautiin, kun taas tumapositiivisuus CXCR4:lle korreloi imusolmuketautiin. Tutkimustulokset kuvaavat DLBCL:n merkittävää biologista heterogeenisyyttä, mutta tulosten varmistamiseksi tarvitaan lisää tutkimuksia. Korkea antioksidanttiaktiivisuus ja solusyklin säätelyhäiriöiden kasautuminen erottivat huonoennusteisia potilasryhmiä, jotka voisivat hyötyä uudenlaisista hoidoista. Kemokiinireseptorien ilmentyminen vaikuttaisi olevan yhteydessä DLBCL:n CNS-hakuisuuteen, ja tulosten varmistuessa ekspressioprofiilien analysointia voitaisiin tulevaisuudessa hyödyntää ennaltaehkäisevien hoitojen tehokkaammassa kohdentamisessa
Bonarriba, Beltrán Carlo Rakso. "Litiasis de oxalato cálcico monohidrato papilar y de dihidrato: estudio comparativo de factores de riesgo." Doctoral thesis, Universitat de les Illes Balears, 2014. http://hdl.handle.net/10803/134501.
Full textCalcium oxalate monohydrate (COM) papillary calculi can be initiated by subepithelial calcification of the renal papillae. Hydroxyapatite disruption of the papillary epithelial layer can become the nidus of a COM papillary calculus. This study evaluated the causes of papillary tissue calcifications in 60 patients with calcium oxalate lithiasis, 30 with COM papillary and 30 with calcium oxalate dihydrate (COD) calculi. Urinary redox potential was higher in the COM papillary than the COD group, suggesting that the former are more deficient in antioxidants due to increased oxidative stress. Urinary calcium was significantly higher in the COD group, whereas urinary oxalate was significantly higher in the COM group, suggesting a great degree of oxidative injury of renal cells.Evaluations of their diets showed that both groups consumed low amounts of phytate-rich products. Of diseases possibly associated with urolithiasis, the prevalence of gastroduodenal ulcer differed significantly, being higher in the COM group and suggesting that epithelial lesions are common to gastroduodenal ulcers and COM papillary renal stones. The prevalence of Diabetes Mellitus type 2 was higher significantly in the COD than the COM papillary group. Occupational exposure to cytotoxic products occurred in 47% of the COM and 27% of the COD group, but this difference was not statistically significant. Metabolic syndrome occurred in 23% of the COD and 3% of the COM papillary. These findings indicate that oxidative stress is associated with injury to papillary tissue and that this is the origin of intrapapillary calcifications. The continuation of this process is due to modulators and/or deficiencies in inhibitors of crystallization. Identifying and eliminating the causes of injury may prevent recurrent episodes in patients with papillary COM calculi.
Byon, Chang Hyun. "Oxidative stress-stimulated vascular calcification." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2009. https://www.mhsl.uab.edu/dt/2010r/byon.pdf.
Full textPelletier, Laure. "Individual and environmental drivers of the foraging behaviour in a long-lived coastal seabird." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01023688.
Full textFairbrass, Danielle L. "Engineering oxidative stress resistance in CHO cell factories." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/16227/.
Full textCastro, Giner Francesc. "Genetic and environmental factors in asthma: a population based European study." Doctoral thesis, Universitat Pompeu Fabra, 2009. http://hdl.handle.net/10803/7194.
Full textAsthma is a disease with a complex etiology, involving multiple genetic and environmental factors, and with an important role of the interplay of these factors through gene-environment interactions. In this thesis I aimed to advance our knowledge on the importance of genetic polymorphisms and their interaction with environmental data for the occurrence of asthma and related phenotypes (atopy and bronchial hyperreactivity). This objective was developed through the replication of genetic associations previously reported, the assessment of gene-environment interactions and the identification of new susceptibility genes using genome-wide analysis based on a pooling DNA strategy. The thesis was, mostly, performed within the European Community Respiratory Health Survey (ECRHS). This cohort has information and DNA samples from approximately 5,000 adult subjects followed-up for 9 years, with extensive questionnaires on respiratory symptoms, clinical evaluations and information on environmental exposures. This thesis replicates previous effects on asthma of polymorphisms in TNFA and NPSR1 genes. In addition, interactions have been established between TNFA and obesity, NQO1 and air-pollution, and NPSR1 and age at onset of asthma. The approach based on genome-wide analysis of DNA pools identified the SGK493 region being associated with atopy. This thesis contributes to the understanding of the etiology of asthma through the identification and replication of genetic associations and gene-environment interactions.
Alkazemi, Dalal Usamah. "Oxidative stress as a cardiovascular risk factor in Canadian Inuit." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114158.
Full textUne baisse dans la consommation des aliments traditionnels chez les Inuits pose un problème nutritionnel car elle fournit des nutriments associés à la protection contre les maladies cardio-vasculaires (MCV). Il existe une controverse, cependant, en ce qui concerne le stress oxydatif chez les Inuits en raison de l'oxydabilité des tissus plus élevée possible de n-3, des acides gras polyinsaturés (AGPI) de l'alimentation traditionnelle des Inuits rich en AGPI n-3, et leur exposition alimentaire à des pro-oxydants et des contaminants tels que le méthylmercure et les biphényles polychlorés (BPC). Nous avons proposé que la détermination de tout état de stress oxydatif du corps via la méthode de l'étalon-or isoprostanes, qui reflètent une réponse globale aux différentes charges métaboliques et des xénobiotiques, puisse être un indicateur des adaptations et des prédispositions des Inuits aux maladies cardiovasculaires. Les objectifs de cette thèse sont les suivants: (i) de quantifier les concentrations plasmatiques de F2-isoprostanes, F3-isoprostanes, et isofurans et d'évaluer leur relation avec les facteurs de risque cardiometabolique (ii) d'évaluer le lieu entre le statut en sélénium et les isoprostanes plasmatiques et d'évaluer la relation entre l'exposition au méthylmercure et du sélénium alimentaire tissus sur un état de stress oxydatif, (iii) d'examiner l'impact de la diminution de la consommation d'aliments traditionnels sur les paramètres du stress oxydatif, et (iv) d'évaluer la contribution des PCB sur le proxidant d'un état de stress oxydatif. Une série d'études transversales ont été réalisées en utilisant les données de l'Enquête sur l'Année Polaire Internationale de la Santé des Inuits (2007-2008). Les analyses transversales ont été menées pour étudier la relation entre l'alimentation (sélénium (Se), n-3 et n-6 AF, gras trans et saturés), les contaminants (MeHg et les PCB), l'obésité et les facteurs de risques cardiovasculaires comme l'hypertension, la dyslipidémie, le tabagisme et la protéine C réactive par rapport à un stress oxydatif avec l'étalon-or F2-isoprostanes et les nouveaux biomarqueurs isoprostane F3-isoprostanes et isofurans. Les concentrations plasmatiques des isoprostanes ont été déterminées par chromatographie en phase gazeuse, par l'ionisation négative chimique d'ions et par la méthode de spectrométrie de masse. Des analyses variées ont été utilisées pour déterminer les corrélats finals de isoprostanes. Les résultats ont montré que les Inuits sont protégés par le mercure causé par le stress oxydatif en raison de leur statut en sélénium élevée, et que les consommateurs d'aliments traditionnels ont été les plus protégés. Tous les isoformes isoprostanes ont été associés à l'obésité. Les F2-isoprostanes et isofurans ont en outre été associés à la protéine C réactive et de la pression artérielle. Aussi, les F3-isoprostanes et isofurans sont davantage liés aux contaminants que les F2-isoprostanes. En règle générale, cette thèse montre que les contaminants dans l'Arctique ne présentent aucun risque sur le stress oxydatif, mais que l'abandon aujourd'hui de la nourriture traditionnelle est associé à l'obésité et le stress induit par l'oxydation inflammatoire. Une constatation importante est que chaque isoprostane possède un attribut unique qui explique le risque potentiel de maladies cardio-vaculaires, et une mesure simultanée des isoprostanes donne un aperçu mécanistique avantageuse dans le stress oxydatif pas capturé par les F2-isoprostanes.
Harris, Jessica Lynn. "INVESTIGATIONS INTO MODULATION OF BRAIN OXIDATIVE STRESS BY VARIOUS INTERVENTIONS." UKnowledge, 2012. http://uknowledge.uky.edu/chemistry_etds/12.
Full textWang, Bo. "Transcriptional regulation of the human NAD(P)H: quinone oxidoreductase gene during oxidative stress." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262435.
Full textLourenço, Rogério Ferreira. "Caracterização dos sistemas ChrR-σR e CC3476σT na resposta de C. crescentus aos estresses oxidativo e osmótico." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-27112008-100001/.
Full textCaulobacter crescentus is among the bacteria whose genomes encode a high number of ECF sigma factors, which are involved in the transcriptional regulation of a limited set of genes in response to several environmental signals. In the present work, two ECF sigma factors from C. crescentus, σR e σT, were functionally characterized. Data showed that σR e σT are maintained in reduced expression levels under physiological growth conditions, due to the action of ChrR and CC3476, respectively. However, during C. crescentus exposure to cadmium, organic hydroperoxide, singlet oxygen and UVA irradiation, σR expression is positively auto-regulated. Transcriptome analyses showed that σR regulates the expression of genes involved in protecting cells against oxidative damages. Central to this transcriptional response is the inactivation of ChrR, with residues C186 and C188 of this protein being necessary for sensing cadmium but not organic hydroperoxide or singlet oxygen. In addition, data revealed that sigR and two other σR-dependent genes (cfaS and CC2258) are essential for C. crescentus survival when oxidative damages are generated in the cells for long periods of time. Similarly, σT expression increases at a transcriptional level in this bacterium under hyperosmotic conditions induced by NaCl or sucrose. Besides being positively auto-regulated, σT independently controls the expression of σU and σE, forming an expression cascade of ECF sigma factors in C. crescentus. σT, but not σU or σE, displays an essential role in C. crescentus survival during NaCl or sucrose exposure. Additionally, the absence of σT leads to an increased sensitivity of this bacterium to H2O2, despite the absence of induction in sigT, sigU or sigE expression under the same stress condition. Therefore, the present work has contributed to the understanding of two mechanisms of C. crescentus adaptation to oxidative and osmotic stresses