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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
401

Estudo morfológico e molecular de proteínas envolvidas nos processos de invasão, migração e angiogênese em gliomas tratados com ácido gama-linolênico. / Morphological and molecular study of proteins involved in the processes of invasion, migration and angiogenesis in gliomas treated with gamma-linolenic acid.

Miyake, Juliano Andreoli 17 November 2009 (has links)
O glioblastoma multiforme (GBM) é a forma mais maligna de tumor cerebral, originado de células astrocíticas e caracterizado pela intensa proliferação, angiogênese e invasão celular pelo parênquima cerebral normal. O ácido gama-linolênico (GLA) mostrou ter ações anti-tumorais, nos processos de proliferação, migração e angiogênese. Utilizou-se o modelo ortotópico de GBM de rato (C6) e o modelo ex vivo tratados com GLA para análise de migração e proliferação celular. Foi observada uma redução da imunomarcação do fator de crescimento para endotélio vascular (VEGF), seu receptor Flt-1 e da metaloproteinase-2 de matriz, com consequente diminuição de vasos após o tratamento com GLA. No modelo ex vivo observou que o GLA reduziu a distância de migração e a mitose das células tumorais e também causou aumento das células tumorais em processo de apoptose. Os resultados revelaram que o GLA foi capaz de modular a expressão de algumas proteínas envolvidas nos processos angiogênico, migratório e proliferativo do GBM, o que sugere a sua utilização no tratamento desta patologia. / Glioblastoma multiforme (GBM) is the most malignant form of brain tumour originating from astrocytes and is characterized by intense proliferation, angiogenesis and cell invasion through the normal brain parenchyma. Gamma-linolenic acid (GLA) has anti-tumour activities in the processes of proliferation, migration and angiogenesis. This study used the orthotopic GBM rat model (C6) and ex vivo model treated with GLA to analyze cell migration and proliferation. Decreased immunostaining was observed for vascular endothelial growth factor (VEGF), its receptor Flt-1 and matrix metalloproteinase-2, with consequent reduction of blood vessels after treatment with GLA. In the ex vivo model GLA reduced the migration distance and mitosis of tumor cells and increased tumour cell apoptosis. The results revealed that GLA was able to modulate the expression of several proteins involved in angiogenesis, migration and proliferation in GBM, supporting the use of GLA in the treatment of this disease.
402

Proposta de uma ferramenta para o gerenciamento da melhoria cont?nua de processos / Proposal of a tool for managing continuous process improvement

OLIVEIRA, Tatiane Pinto de 31 January 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-12-06T15:33:47Z No. of bitstreams: 1 2013 - Tatiane Pinto de Oliveira.pdf: 9317541 bytes, checksum: 679ad8a2ef29c5f4173b89c71984becf (MD5) / Made available in DSpace on 2018-12-06T15:33:47Z (GMT). No. of bitstreams: 1 2013 - Tatiane Pinto de Oliveira.pdf: 9317541 bytes, checksum: 679ad8a2ef29c5f4173b89c71984becf (MD5) Previous issue date: 2013-01-31 / The objective of this dissertation was to propose, implement and validate a tool for managing continuous process improvement through integration of two well-known tools in the market, the Omega 8 Orca, aimed to assess the maturity of processes, and the BSC, as manager of the results, in order to give these organizations a more targeted tool for the Brazilian. From an integrated view of these methods was designed Iris - Manager of Organizational Process Maturity. In general, this tool proposes to assess the maturity levels of six strategic elements - top management commitment, organization and structure, training, performance indicators, customer relationship and integration of information system - representing the management structure of organizations, mapping the current levels of maturity and realizing the projected future levels, desired by companies. To address the gap between the company's current stages and the stages desired are proposed action plans, which designate what measures, should be taken to ensure that the objectives are achieved. To follow up the evolution of these maturity levels, it was proposed to use the method of measuring the BSC, which has its four perspectives linked to the strategic elements of the 8 Omega ORCA. Action research was chosen as the implementation methodology of this study, to propose a suitable method of preparation and implementation of organizational studies. Thus, this methodology allowed the study objectives were achieved in the implementation of the tool in the two selected companies. The development of the research took place in two stages to validate the proposed tool. In this study validated the phases of implementation, regarding the evaluation of the maturity of organizational processes. The validation step of measuring the evolution of the elements was not possible in this study because tracking the development of maturity of the companies? demand more time than willing to complete this survey. However, the results of the three phases, related to the maturity of the companies studied were validated through interviews with their representatives, and the issues raised were arranged in a conceptual map, which summarizes the perceptions of companies about the proposed tool. The tool was considered an ally to the strategic decisions of firms and organizational development. / O objetivo desta disserta??o foi propor, implantar e validar uma ferramenta para gerenciamento da melhoria cont?nua de processos por meio da integra??o de duas ferramentas conhecidas no mercado, o Omega 8 Orca, voltada para avaliar a maturidade de processos, e o BSC, como gerenciador dos resultados, de modo a dotar essas organiza??es de uma ferramenta mais direcionada ? realidade brasileira. A partir de uma vis?o integrada destes m?todos foi idealizado o ?ris - Gerenciador de Maturidade de Processos Organizacionais. De um modo geral, esta ferramenta prop?e avaliar os n?veis de maturidade de seis elementos estrat?gicos - comprometimento da alta dire??o, organiza??o e estrutura, treinamento, indicadores de desempenho, relacionamento com os clientes e integra??o do sistema de informa??o - que representam a estrutura gerencial das organiza??es, mapeando os n?veis atuais de maturidade e realizando a proje??o dos n?veis futuros, desejados pelas empresas. Para solucionar a dist?ncia, entre os est?gios atuais da empresa e os est?gios desejados, s?o propostos planos de a??o, que designam quais medidas devem ser tomadas para que os objetivos sejam alcan?ados. Para realizar o acompanhamento da evolu??o de maturidade desses n?veis, foi proposta a utiliza??o do m?todo de mensura??o do BSC, que possui as suas quatro perspectivas atreladas aos elementos estrat?gicos do 8 Omega ORCA. A pesquisa-a??o foi escolhida como metodologia de implanta??o deste estudo, por propor um m?todo adequado de elabora??o e implanta??o de estudos organizacionais. Assim, essa metodologia permitiu que os objetivos do estudo fossem alcan?ados na implanta??o da ferramenta nas duas empresas selecionadas. O desenvolvimento da pesquisa se deu em dois momentos para a valida??o da ferramenta proposta. Neste trabalho foram validadas as fases de implanta??o, referentes ? avalia??o da maturidade dos processos organizacionais. A etapa de valida??o da mensura??o da evolu??o dos elementos n?o foi poss?vel neste estudo, pois o acompanhamento do desenvolvimento de maturidade das empresas demanda mais tempo do que o disposto para a conclus?o desta pesquisa. Por?m, os resultados das tr?s fases, referentes ? maturidade das empresas estudadas, foram validados atrav?s de entrevistas com os seus representantes, e os temas levantados foram dispostos num mapa conceitual, que resumiu as percep??es das empresas sobre a ferramenta proposta. A ferramenta foi considerada como uma aliada ?s decis?es estrat?gicas das empresas e ao desenvolvimento organizacional.
403

Assessment of Red Blood Cell Membrane Fatty Acid Composition in Relation to Dietary Intake in Patients Undergoing Cardiac Catheterization

Litwin, Nicole S 01 May 2014 (has links)
Red blood cells (RBC) have been shown to mediate plaque development seen in coronary artery disease (CAD). This study determined whether differences in RBC fatty acid (FA) composition were related to CAD risk. FAs were extracted from RBCs of 38 individuals who have undergone cardiac catheterization, 9 of whom had obstructive CAD, and analyzed via gas chromatography. Ferric reducing ability of plasma (FRAP) assay was used to determine oxidative stress. Food frequency questionnaires were used to correlate RBC omega-3 FA to daily intake of omega-3 FA. No correlation was found between RBC content and intake of omega-3 FA. FRAP values and RBC FA composition did not differ between the 2 groups with exception of the saturated FA, palmitic acid (p=0.018). These results suggest that RBC FA composition may differ between individuals with or at risk for CAD. Additional research is needed to validate this biomarker as a predictor of CAD.
404

Etude comparative des effets biologiques des acides gras polyinsaturés oméga-3 (ALA, EPA, DHA) : importance dans la prévention de l'obésité et du syndrome métabolique / A comparative study of the biological effects of polyunsaturated fatty acids (ALA, EPA, DHA) and their significance on preventing obesity and metabolic syndrome

Pinel, Alexandre 18 December 2015 (has links)
L’obésité est un état physiopathologique d’origine multifactorielle caractérisé par une accumulation excessive de tissu adipeux (TA). Elle est associée à une augmentation du risque de développer une insulino-résistance (IR), un syndrome métabolique et, à terme, un diabète de type 2. L’altération des fonctions du TA au cours de l’obésité joue un rôle central dans l’apparition des troubles métaboliques, tels qu’une accumulation ectopique de graisse et une IR périphérique, notamment dans le muscle. Dans ce contexte, la qualité des apports énergétiques et plus précisément en lipides pourrait jouer un rôle important dans l’adaptation des tissus au cours de l’obésité. Ainsi le palmitate (PAL), un acide gras saturé (AGS) est pro-lipogénique, pro-inflammatoire et lipotoxique, ce qui favorise l’apparition d’une IR. Les acides gras polyinsaturés oméga-3 (3) auraient des effets antagonistes au PAL et donc potentiellement protecteurs vis-à-vis des perturbations métaboliques associées à l’obésité. Parmi les 3, les effets spécifiques des trois principaux acides gras alimentaires, les acides alpha-linolénique (ALA), éicosapentaénoïque (EPA) et docosahexaénoïque (DHA), ont été très peu décrits.L’objectif principal de ce travail de thèse a été d’étudier les effets propres de l’ALA, de l’EPA et du DHA sur les altérations métaboliques induites en situation d’obésité. Des explorations mécanistiques ont été réalisées sur les cellules musculaires C2C12 dans lesquelles l’IR a été induite par le PAL et sur des adipocytes 3T3-L1 pour étudier l’impact des AGPI 3 sur la différenciation adipocytaire. Les effets des AGPI 3 ont ensuite été étudiés in vivo, en supplémentant des souris C57BL/6 sauvages ou déficientes en leptine (ob/ob) lors de la consommation d’un régime obésogène riche en lipides et en sucrose (mimant un régime occidental).Dans les cellules musculaires C2C12, les trois 3 co-incubés avec le PAL ont induit de façon comparable une diminution du contenu en composés lipotoxiques et une amélioration de la captation du glucose, mais seuls l’EPA et le DHA ont restauré la -oxydation du PAL et l’activation de la voie de signalisation de l’insuline. De plus, l’EPA et le DHA ont eu un effet protecteur supérieur à l’ALA vis-à-vis de l’inflammation induite par le PAL. Dans le modèle in vivo, seul la supplémentation en EPA a amélioré l’homéostasie du glucose en comparaison avec les supplémentations en ALA et en DHA. Alors que l’EPA a réduit la prise de masse grasse, le DHA a induit une hypertrophie des cellules adipeuses associée à une augmentation de la sécrétion de leptine et une baisse de la sécrétion d’adiponectine. Dans un modèle d’adipocytes 3T3-L1 en culture, le DHA a accéléré la différenciation des préadipocytes en comparaison avec l’ALA et l’EPA, pouvant expliquer son effet hypertrophique in vivo.En conclusion et dans nos conditions expérimentales, les 3 ALA, EPA et DHA ont bien des effets communs sur le métabolisme lipidique et glucidique in vitro mais également des effets propres qui ont permis de montrer qu’une supplémentation nutritionnelle en EPA serait plus intéressante pour limiter l’IR in vivo par rapport au DHA ou à l’ALA. Le DHA a quant à lui favorisé l’hypertrophie du TA, perturbant ainsi la sécrétion des adipokines participant à la régulation de la sensibilité à l’insuline des tissus périphériques, comme le muscle squelettique. / Obesity is characterized by an excess of adipose tissue (AT) mass and may be caused by multiple factors. It is associated with an increased risk of the development of insulin-resistance (IR) and metabolic syndrome, leading to type 2 diabetes. The impairment of lipid storage in the AT play a central role in obesity-associated disorders, as it leads to ectopic lipid accumulation and peripheral IR notably in muscles. In this context, the quality of dietary lipids may play a role in the regulation of AT and muscle metabolisms. In fact, palmitic acid (PAL), a saturated fatty acid (SFA) induces lipogenesis, inflammation and lipotoxicity favoring IR in many tissues. On the contrary, omega-3 polyunsaturated fatty acids (3) have protective effect against obesity-associated disorders. Among them, linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) specific effects remained partially described.This work aimed at exploring the specific effects of 3 on metabolic disorders and the development of obesity. Mechanisms were studied in C2C12 muscle cells during PAL-induced IR and in 3T3-L1 adipocytes to determine the impact of 3 on adipocyte differentiation. In vivo, the effects of 3 were investigated by supplementating C57BL/6 wild-type or leptin-deficient (ob/ob) mice with ALA, EPA or DHA during a high fat / high sucrose diet (mimicking a western diet).In C2C12 muscle cells, co-incubation of 3 with PAL induced a similar decrease in the content of lipotoxic compound and improved glucose uptake, whereas only EPA and DHA restored -oxidation and insulin signaling activation. Furthermore, EPA and DHA were more potent to reduce PAL-induced inflammation compared to ALA. In mice, only EPA improved whole body glucose homeostasis compared to ALA and DHA. While EPA reduced body fat gain, DHA induced hypertrophy in AT, increased leptin secretion and decreased those of adiponectine. In cultured 3T3-L1 adipocytes, preadipocyte differentiation was also induced by DHA compared to ALA and EPA and might explain the hypertrophy observed in mice.In conclusion and in our experimental conditions, ALA, EPA and DHA have common effects on in vitro lipid and glucose metabolism but also specific effects, demonstrating that EPA would be more interesting to limit IR in vivo compared to DHA or ALA. DHA favored hypertrophy of AT and disturbance of adipokine secretion involved in peripheral regulation of insulin sensitivity, notably in muscle.
405

N-3 fatty acids, eicosanoids and control of inflammation / by Joanna Susan Hawkes

Hawkes, Joanna Susan January 1993 (has links)
Errata slip inserted / Bibliography: leaves 178-199 / xxi, 199, [55] leaves, [3] leaves of plates : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, and Rheumatology Unit, Royal Adelaide Hospital, 1994
406

Establishment and characterization of a murine T-cell lymphoma/leukemia model

Johansson, Ann-Sofie January 2010 (has links)
Mouse models of human disease are valuable tools for studying pathogenesis and for evaluating novel therapies. T-cell lymphoma is a relatively rare disease in humans, affecting 100-150 persons yearly in Sweden. It exists in both aggressive and more indolent forms. We have established a mouse model for an aggressive T-cell lymphoma, the T-cell lymphoma/leukemia (TLL) mouse. In the present thesis, the TLL mouse model was characterized and used for experimental therapeutic and primary prevention studies. The TLL mouse was established unintentionally in our laboratory during work on VH-gene replacement in a “knock-in” mouse experimental setting. The generated chimeras all developed aggressive T-cell lymphomas affecting the lymphoid organs, lungs, kidneys and liver. The lymphoma phenotype segregated from the targeted locus and we could demonstrate the presence of Moloney murine leukemia virus (MMLV) in the germline of the affected mice. MMLV is a retrovirus known to induce T-cell lymphomas when inoculated in newborn mice.  We further characterized two TLL substrains; TLL-2 and TLL-14 carrying the proviral integrations on chromosomes 2 and 14 respectively. Significant differences were found between the substrains regarding lymphoma frequency and immunophenotype, the TLL-14 substrain developing tumors with higher frequency than TLL-2 and with a more mature immunophenotype. A transfer model was developed in which TLL cells could be readily transferred intravenously to syngenic recipients causing aggressive lymphomas. The transfer model was used in a therapeutic study where the selective COX-2 inhibitor celecoxib was evaluated as a single agent and in combination with the established anti-tumor agent cyclophosphamide. The study was based on results from other tumor types that have indicated celecoxib, originally an anti-inflammatory and analgetic drug, to have possible anti-tumor effects. In our TLL model, however, we could not demonstrate any benefit of celecoxib monotherapy or any additive effect to cyclophosphamide. Dietary fatty acids, in particular omega-3 fatty acids, have been a focus of public and scientific interest due to observed effects on the prevention of cardiovascular disease, cancer and inflammatory conditions. In addition, omega-3 fatty acids inhibit T-cell proliferation in vitro. We supplemented the diet of TLL mice with omega-3 and omega-6 fatty acids respectively and could demonstrate a significant delay in lymphoma onset between 5-8 months of age in the group receiving an omega-3 rich diet.
407

Linker-based Lecithin Oral Drug Delivery Systems

Chu, Jacquelene 04 December 2012 (has links)
In this study, pharmaceutical-grade and food-grade linker-based lecithin self-emulsifying delivery systems (SEDS) were developed with a combination of lipophilic and hydrophilic linkers. These additives at suggested concentrations are safe for pharmaceutical and food applications. The ratio of surfactant lecithin and linkers in these systems was optimized to develop surfactant in oil preconcentrates. The preconcentrates containing different surfactant concentrations and oil were diluted with fed state simulated intestinal fluid to produce pseudo-ternary phase diagrams and to identify the formulations that produced self-emulsifying or self-microemulsifying delivery systems. Optimal SEDS preconcentrates were evaluated using a dialyzer model to simulate intestinal uptake. An uptake of 39.6 mg/cm2 for the pharmaceutical-grade SEDS was obtained within 72 minutes, which promises substantial improvement in the bioavailability of hydrophobic actives. The optimal uptake of 12.2 mg/cm2 for food-grade SEDS suggests enhancement in the bioavailability of omega-3 fatty acids.
408

Glutatation Transferasas de clase Omega en Saccharomyces cerevisiae: Estudio Bioquímico y Funcional

Barreto Parra, Lina Patricia 19 January 2007 (has links)
Saccharomyces cerevisiae posseeix dues glutatió transferases (GST) anomenades Gtt1i Gtt2, amb capacitat de conjugar una molècula de glutatió amb el substrat estàndarCDNB. Aquests dos enzims no són clasificables dins de les classes convencionalsdescrites en base a l'estructura de les GST d'eucariotes superiors, encara que guardencerta similitud estructural amb els membres de la classe Zeta. En aquesta memòria esdescriu la caracterització de tres GST de classe Omega en S. cerevisiae anomenadesGto1, Gto2 i Gto3, codificades respectivament per les ORFs YGR154c, YKR076w iYMR251w. Els enzims d'aquesta classe no tenen activitat sobre CDNB, però són activescom tiol oxidoreductases i posseïxen activitat dehidroascorbat reductasa i dimetilarsenatreductasa. La primera d'elles, Gto1, és peroxisomal i posseïx un senyal de localitzacióde tipus PTS1 en la regió C-terminal. Aquest senyal és reconeguda pel transportadorperoxisomal Pex5, que facilita la seva internalizació en aquest organul. D´altre banda,Gto2 i Gto3 tenen localització citoplàsmica. Els gens GTO de S. cerevisiae s'induïxenper estrès oxidativu però amb patrons distints per als tres gens. La dependènciad'aquesta expressió dels factors de trascripció Yap1, Msn2 i Msn4 es relaciona amb lapresència de seqüències YRE i STRE en els promotors dels gens GTO. El mutant Dgto1és sensible a l'agent oxidant diamida i té una concentració intracel· lular de glutatiómenor que la soca silvestre. Aquest fenotip es relaciona amb que el triple mutant Dgtt2Dgtt1 Dgto1 sigui sensible al cadmi, indicant que les tres GST Gtt1, Gtt2 i Gto1intervenen en la detoxificació d'aquest metall. Altre fenotip rellevant és la dificultat delmutant Dgto1 per a créixer en medis de cultiu amb àcid oleic com única font de carboni,indicant que les funcions peroxisomals en el mutant estan afectades. L'absència deGTO1 en S. cerevisiae causa així mateix el descens en l'expressió de gens involucratsen la via de síntesi de cisteïna i metionina. Com a conseqüència, el mutant Dgto1 creixamb dificultat en absència de treonina, serina o lisina. La manca de GTO1 en S.cerevisiae impedeix que utilitzi eficientment la cisteïna o la cistationina com úniquesfonts de sofre, manifestant defectes en la transulfuració, procés que permet la síntesi demetionina a partir de cisteïna. Això suggereix que Gto1 podria estar regulant l'activitatcistationina b-liasa de Str3 mitjançant la seva activitat tiol oxidoreductasa, atès que Str3també és peroxisomal. Atès que la cisteína 387 de Str3 és important per a la sevaactivitat biològica i està conservada en les cistationina b-liasas d'altres espècies defongs, aquest residu podria ser diana de Gto1 per a la regulació de l'estat redox de laproteïna Str3RESÚMENSaccharomyces cerevisiae posee dos glutatión transferasas (GST) denominadas Gtt1 yGtt2 con capacidad de conjugar una molécula de glutatión con el sustrato estándarCDNB. Estas dos enzimas no son clasificables dentro de las clases convencionalesdescritas con base en la estructura de las GST de eucariotas superiores, aunqueguardan cierta similitud estructural con las de clase Zeta. En esta memoria se describela caracterización de tres GST de clase Omega en S. cerevisiae denominadas Gto1,Gto2 y Gto3, codificadas por las ORF YGR154c, YKR076w y YMR251w. Las enzimasde esta clase no tienen actividad sobre CDNB, pero son activas como tioloxidoreductasa y poseen actividad dehidroascorbato reductasa y dimetilarsenatoreductasa. La primera de ellas, Gto1, es peroxisomal y posee una señal de localizaciónde tipo PTS1 en la región C-terminal. Dicha señal es reconocida por el transportadorperoxisomal Pex5, que facilita su internalización en este organelo. Por otra parte, Gto2y Gto3 tienen localización citoplásmica. Los genes GTO de S. cerevisiae se inducen porestrés oxidativo pero con patrones distintos para los tres genes. La dependencia de estaexpresión de los factores de trascripción Yap1, Msn2 y Msn4 se relaciona con lapresencia de secuencias YRE y STRE en los promotores de dichos genes. El mutanteDgto1 es sensible al agente oxidante diamida y tiene una concentración intracelular deglutatión menor que la cepa silvestre. Este fenotipo se relaciona con que el triplemutante Dgtt1 Dgtt2 Dgto1 sea sensible al cadmio, indicando que las tres GST Gtt1,Gtt2 y Gto1 intervienen en la detoxificación de este metal. Otro fenotipo relevante es ladificultad del mutante Dgto1 para crecer en medios con ácido oleico como única fuentede carbono, indicando que las funciones peroxisomales en dicho mutante estánafectadas. La ausencia de GTO1 en S. cerevisiae causa así mismo el descenso en laexpresión de varios genes involucrados en la vía de síntesis de cisteína y metionina.Como consecuencia, el mutante Dgto1 crece con dificultad en ausencia de treonina,serina o lisina. La ausencia de Gto1 en S. cerevisiae impide que utilice eficientementela cisteína o la cistationina como únicas fuentes de azufre, manifestando defectos en latransulfuración, proceso que permite la síntesis de metionina a partir de cisteína. Ellosugiere que Gto1 podría estar regulando la actividad cistationina b-liasa de Str3mediante su actividad tiol oxidoreductasa, dado que Str3 también es peroxisomal.Dado que la cisteína 387 de Str3 es importante para su actividad biológica y estáconservada en las cistationina b-liasas de otras especies de hongos, este residuopodría ser diana de Gto1 para la regulación del estado redox de la proteína Str3.SUMARYSUMMARYSaccharomyces cerevisiae contains two glutathion transferases (GST) named Gtt1 andGtt2, which are enzymes with glutathione conjugating activity with the standard substrateCDNB. These two enzymes are not classified into the conventional classes that havebeen established based on the structure of mammalian GST, although they keep certainstructural similarity with Zeta class members. In this report, we describe thecharacterization of three S. cerevisiae Omega class GST named Gto1, Gto2 and Gto3,coded by ORFs YGR154c, YKR076w and YMR251w, respectively. The enzymes ofthis class do not exhibit activity with CDNB but they are active as tiol oxidoreductases,dehydroascorbate reductases and dimetilarsonate reductases. The first of them, Gto1,is located at the peroxisome and is targeted to this organelle throught a C-terminalPTS1-type sequence. This sequence is recognized by the peroxisomal transporterPex5 that facilitates peroxisomal import. On the other hand, Gto2 and Gto3 are at thecytosol. The GTO genes of S. cerevisiae are induced by oxidative stress, although theexpression patterns are different for the three genes. The expression of GTO genesdepends on Yap1, Msn2 and Msn4 transcription factors and correlates with thepresence of YRE and STRE sequences in the promoters of these genes. The absenceof GTO1 causes a hipersensitivity to the oxidant diamide in S. cerevisiae and reducesthe intracelular concentration of glutathione, compared with the wild type stain. Thisphenotype is related to cadmium sensitivity of the Dgtt1 Dgtt2 Dgto1 triple mutant,indicating that Gtt1, Gtt2 and Gto1 participate in the response to cadmium toxicity.Another rellevant phenotype of S. cerevisiae cells lacking GTO1 is the growth defectwith oleic acid as the sole carbon source, indicating that the peroxisome funtions areaffected in the mutant. This mutant also grows defficiently in the absence of threonine,serine or lysine in the growth medium. Lack of GTO1 function also affects negativelythe expression of several genes involved in methionine and cisteine sinthesis. As aconsecuence, the Dgto1 mutant shows defective growth in a medium with cisteine orcistationine as the sole sulfur source as a consequence of defective trasulfuration, aprocess that allows methionine synthesis from cisteine. This suggests that Gto1 couldregulate the cystathionine b-lyase activity of Str3 through its thiol oxidoreductaseactivity, since Str3 is also peroxisomal. As the cysteine 387 residue of Str3 is importantfor the biological activity of this protein and is conserved in fungal species, this residuecould be a target of Gto1 for the regulation of the redox state of Str3.
409

Omega-3 Fatty Acid Blood Biomarkers Before and After Acute Fish Oil Supplementation in Men and Women

Metherel, Adam Henry January 2007 (has links)
Omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicospentaenoic acid (EPA), are important mediators for cardiovascular disease, fetal/infant development, neurological disorders and inflammatory diseases. Supplementation and washout studies are important for future research on the physiological effects of omega-3 fatty acids and for determination of the proper washout period for future cross-over studies. In this study, omega-3 fatty acid blood biomarker comparisons are made for the n-3 HUFA score (% of n-3 HUFAs in total HUFAs) and omega-3 index (sum of EPA + DHA) in plasma, erythrocytes, whole blood and a novel finger-tip prick blood method (FTPB) of analysis. This FTPB method of fatty acid analysis is further tested to determine the potential for its use in fatty acid analysis. In addition, gender differences in response to omega-3 fish oil supplementation are analyzed in all four blood fractions. Nine males and seven females were supplemented with 8 fish-oil capsules per day (providing 3.2 g/day EPA and 1.6 g/day DHA) for four weeks, followed by an eight-week omega-3 washout period. Venous plasma, erythrocyte and whole blood samples were collected during weeks 0, 4, 8 and 12 and FTPB samples were collected weekly during supplementation and washout fatty acid analysis was performed. EPA and DHA incorporation is lowest in magnitude in erythrocytes relative to all other blood fractions. Omega-3 blood biomarker comparisons demonstrate that the n-3 HUFA score is a more reliable measure across all blood fractions compared to the omega-3 index. In addition, the n-3 HUFA score demonstrates no differences (p > 0.05) between FTPB and whole blood analysis, providing evidence to support its usefulness as a tool for fatty acid analysis. However, differences (p < 0.05) do exist between these methods for saturated fatty acid, monounsaturated fatty acids, omega-6 polyunsaturated fatty acids (PUFAs) and omega-3 PUFAs. Baseline fatty acid levels for DHA, and the DHA:EPA and DHA:DPA ratios tend to be higher (p < 0.05) in females, and docosapentaenoic acid n-3 (DPAn-3) is higher (p > 0.05) in males across all blood fractions. Furthermore, a gender effect (p < 0.05) is seen for the DHA:EPA ratio across all blood fractions. At baseline, female DHA:EPA is higher (p < 0.05) than males with supplementation lowering both male and female values and removing any differences (p > 0.05) between genders. Washout results in a return of levels towards baseline, however, baseline levels are not fully reached. Furthermore, while gender differences do begin to reform during washout, these differences are not significant (p > 0.05). In conclusion, omega-3 fatty acid responses, particularly DHA:EPA ratio, demonstrate significant gender differences that may be related to differences in long-chain PUFA synthesis pathways between males and females. In addition, the n-3 HUFA score may be a more valuable omega-3 blood biomarker than the omega-3 index, as the n-3 HUFA score displays more consistent levels across all blood fractions. Finally, the FTPB method of analysis may be a useful tool in the measurement of fatty acid composition, however, some microwave methylation problems do exist, specifically in the phospholipid class of lipids.
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Omega-3 Fatty Acid Blood Biomarkers Before and After Acute Fish Oil Supplementation in Men and Women

Metherel, Adam Henry January 2007 (has links)
Omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicospentaenoic acid (EPA), are important mediators for cardiovascular disease, fetal/infant development, neurological disorders and inflammatory diseases. Supplementation and washout studies are important for future research on the physiological effects of omega-3 fatty acids and for determination of the proper washout period for future cross-over studies. In this study, omega-3 fatty acid blood biomarker comparisons are made for the n-3 HUFA score (% of n-3 HUFAs in total HUFAs) and omega-3 index (sum of EPA + DHA) in plasma, erythrocytes, whole blood and a novel finger-tip prick blood method (FTPB) of analysis. This FTPB method of fatty acid analysis is further tested to determine the potential for its use in fatty acid analysis. In addition, gender differences in response to omega-3 fish oil supplementation are analyzed in all four blood fractions. Nine males and seven females were supplemented with 8 fish-oil capsules per day (providing 3.2 g/day EPA and 1.6 g/day DHA) for four weeks, followed by an eight-week omega-3 washout period. Venous plasma, erythrocyte and whole blood samples were collected during weeks 0, 4, 8 and 12 and FTPB samples were collected weekly during supplementation and washout fatty acid analysis was performed. EPA and DHA incorporation is lowest in magnitude in erythrocytes relative to all other blood fractions. Omega-3 blood biomarker comparisons demonstrate that the n-3 HUFA score is a more reliable measure across all blood fractions compared to the omega-3 index. In addition, the n-3 HUFA score demonstrates no differences (p > 0.05) between FTPB and whole blood analysis, providing evidence to support its usefulness as a tool for fatty acid analysis. However, differences (p < 0.05) do exist between these methods for saturated fatty acid, monounsaturated fatty acids, omega-6 polyunsaturated fatty acids (PUFAs) and omega-3 PUFAs. Baseline fatty acid levels for DHA, and the DHA:EPA and DHA:DPA ratios tend to be higher (p < 0.05) in females, and docosapentaenoic acid n-3 (DPAn-3) is higher (p > 0.05) in males across all blood fractions. Furthermore, a gender effect (p < 0.05) is seen for the DHA:EPA ratio across all blood fractions. At baseline, female DHA:EPA is higher (p < 0.05) than males with supplementation lowering both male and female values and removing any differences (p > 0.05) between genders. Washout results in a return of levels towards baseline, however, baseline levels are not fully reached. Furthermore, while gender differences do begin to reform during washout, these differences are not significant (p > 0.05). In conclusion, omega-3 fatty acid responses, particularly DHA:EPA ratio, demonstrate significant gender differences that may be related to differences in long-chain PUFA synthesis pathways between males and females. In addition, the n-3 HUFA score may be a more valuable omega-3 blood biomarker than the omega-3 index, as the n-3 HUFA score displays more consistent levels across all blood fractions. Finally, the FTPB method of analysis may be a useful tool in the measurement of fatty acid composition, however, some microwave methylation problems do exist, specifically in the phospholipid class of lipids.

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