Tesis sobre el tema "Citrate metabolism"
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Levasseur, Rémi. "Aluminum citrate transport and metabolism in Pseudomonas fluorescens". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0018/MQ46489.pdf.
Texto completoJúnior, Celso Heitor de Freitas. "Avaliação metabólica de homens idosos portadores de litíase urinária". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/5/5153/tde-12012012-154818/.
Texto completoPURPOSES: Rise in life expectancy has caused a global populational ageing and people older than 60-years have increased more than any other age group. The incidence of urinary lithiasis in aging people has increased during the last years, mainly in developed nations. Some aspects concerning organic ageing increase morbidity related to urolithiasis in older individuals making prevention and medical management of urinary stones relevant in this age group. Our objective is to evaluate metabolic parameters in men older than 60 years with urinary stones. MATERIALS AND METHODS: A case-control study was performed. Inclusion criteria were: men older than 60- years old with renal pain episodes or incidental diagnosis of urinary lithiasis beginning after 60-years old (case arm). Control group was constituted by patients older than 60 years without renal colic past or diagnosis of urolithiasis. Patients were recruited from a database from the Urologic Clinic at University of São Paulo Medical School Hospital. Each individual was submitted to anamnesis and those selected underwent a metabolic evaluation for urinary stones: serum dosages of total and ionized calcium, uric acid, phosphorus, glucose, urea, creatinine and parathyroid hormone (PTH); urine culture and urinary pH. Twenty four hour urine samples were obtained for volume quantification and for calcium, citrate, creatinine, uric acid and sodium dosages. An abdominal x-ray and ultrasonography were performed in all patients. Case arm patients underwent two complete metabolic urinary investigations while control arm individuals to only one. All results were submitted to statistical analysis. RESULTS: One hundred and ten individuals were called up for initial evaluation and 70 were selected. Fifty-one individuals concluded the whole clinical investigation: 25 in the case arm and 26 in the control arm. Hypocitraturia was present in 56% of case arm patients and 15,4% of the control arm patients (p=0,002). Hypernatriuria in 24-hour urine samples was found in 64% of case arm patients and in 30,8% of control arm patients (p=0,017). These results were submitted to univariate and multiple logistic regressions and maintained their levels of significancy. CONCLUSION: Hypocitraturia and hypernatriuria are the main metabolic disorders among aging men with urolithiasis
Jeffery, David. "Studies on citrate and malate metabolism in Lycopersicon esculentum". Thesis, University of Bath, 1985. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353243.
Texto completoAl-Tarrah, Mustafa. "The effect of citrate synthase on skeletal muscle metabolism". Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=235778.
Texto completoDufort, Fay Josephine. "Contribution of Glucose Metabolism to the B Lymphocyte Responses". Thesis, Boston College, 2012. http://hdl.handle.net/2345/3161.
Texto completoB-lymphocytes respond to environmental cues for their survival, growth, and differentiation through receptor-mediated signaling pathways. Naïve Blymphocytes must acquire and metabolize external glucose in order to support the bioenergetics associated with maintaining cell volume, ion gradients, and basal macromolecular synthesis. The up-regulation of glycolytic enzyme expression and activity via engaged B-cell receptor mediated-events was glucose-dependent. This suggests an essential role for glucose energy metabolism in the promotion of B cell growth, survival, and proliferation in response to extracellular stimuli. In addition, the activity of ATP-citrate lyase (ACL) was determined to be crucial for ex vivo splenic B cell differentiation to antibody-producing cells wherein B cells undergo endomembrane synthesis and expansion. This investigation employed knockout murine models as well as chemical inhibitors to determine the signaling components and enzymes responsible for glucose utilization and incorporation into membrane lipids. These results point to a critical role for phosphatidylinositol 3- kinase (PI3K) in orchestrating cellular glucose energy metabolism and glucosedependent de novo lipogenesis for B lymphocyte responses
Thesis (PhD) — Boston College, 2012
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
Roberts, Andrew. "Crassulacean acid metabolism and photosynthetic plasticity in the genus Clusia : an ecophysiological study". Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360879.
Texto completoSaeed, Saima. "The role of mitochondrial citrate synthase in the metabolism of developing potato tubers". Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621806.
Texto completoSienkiewicz-Porzucek, Agata. "Evaluation of the role of mitochondrial citrate synthase, mitochondrial and cytosolic isoforms of isocitrate dehydrogenase in tomato leaf metabolism". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2010. http://dx.doi.org/10.18452/16074.
Texto completoAlthough the TCA cycle is a respiratory metabolic pathway of central importance for all living organisms, relatively few molecular physiological studies of plants were performed to date. Here, I report the generation and functional analysis of tomato plants (Solanum lycopersicum) independently displaying mildly limited activity of mitochondrial citrate synthase (CS) and two isocitrate dehydrogenases, namely mitochondrial NAD-IDH and cytosolic NADP-ICDH. The transgenic plants revealed minor phenotypic alterations. Although the leaf photosynthetic performance was largely unaltered, the changes in mitochondrial respiration and carbon flux through the TCA cycle were observed. Moreover, the plants were characterized by significant modifications in the leaf metabolic content and in maximal catalytic activities of several enzymes involved in primary C and N metabolism. These results hint towards limitations in nitrate assimilation pathway. The transcript profiling performed by utilizing TOM1 microarrays and quantitative RT-PCR approach revealed that the deficiency in mitochondrial CS activity was partially compensated by up-regulation of peroxisomal CS isoform. The limitations in the activities of isocitrate dehydrogenases resulted in up-regulation of the photorespiratory pathway, which presumably played a compensatory role in supporting organic acid production and re-establishing redox balance in the transgenic leaves. Interestingly, the leaf metabolic response towards nitrogen starvation conditions was far more dramatic in NADP-ICDH transgenic plants than NAD-IDH plants, hinting that the cytosolic isoform may be the major 2-oxoglutarate supplier in tomato metabolism.
Daniels, Martin André [Verfasser]. "The mammalian citrate transporter mINDY (I’m not dead yet) and its protective role in hepatic metabolism / Martin André Daniels". Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2021. http://d-nb.info/1228860742/34.
Texto completoAlhindi, Yosra. "Effects of low citrate synthase activity on physiological responses of mice to high fat diet and palmitate induced lipotoxicity". Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231391.
Texto completoDa, veiga moreira Jorgelindo. "Modélisation de la bascule métabolique chez les cellules eucaryotes : application à la production de citrate chez la levure Yarrowia lipolytica". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX015/document.
Texto completoThe main goal of this thesis project is to study and characterize mechanisms involved in respiratory to fermentative shift in eukaryotic cells endowed with mitochondrial metabolism. Eukaryotic cells have different oxygen requirements for energy production and survival in a given environment. They are described as strict aerobic when the presence of oxygen is necessary or optional aero-anaerobic in when oxygen is not essential for energy production. The yeast Yarrowia lipolytica was chosen as our study model thanks to its particularity since it is a strict aerobic microorganism with a high capacity to accumulate lipids and to produce organic acids. Experimental and analytical studies, using mathematical methods for modeling cell metabolism, allowed us to identify metabolic constraints involved in respiratory to fermentative transition in this yeast showing oxidative energy metabolism. Production of citric acid by Y. lipolytica, already reported in the literature, has been chosen as a marker for this in respiratory to fermentative shift. We found that the inhibition of the alternative oxidase protein (AOX) involved in mitochondrial respiration, by adding n-Propyl gallate (nPG) molecule improves the yield of citric acid production by fermentation of glucose in a Y. lipolytica culture. These results show that nPG, already used in food and pharmaceutical industry as a preservative, plays on respiratory to fermentative balance by inhibition of oxygen consumption and thus stimulates the production of citric acid. Modeling of the metabolic network of Y. lipolytica, described at genome-scale, by dynamic Flux Balance Analysis (FBA) has identified the accumulation of intracellular ROS (Reactive Oxygen Species) species as major levers for respiratory to fermentative shift and therefore the production of citric acid by Y. lipolytica. Therefore, our preliminary results show that oxidation of lipids accumulated by Y. lipolytica could be involved in generation of ROS species. This study must be experimentally deepened and constitutes an important contribution for the agri-food and pharmaceutical industry.Key words: Respiratory to fermentative shift, Citric acid, lipids, Yarrowia lipolytica, n-Propyl gallate, Reactive Oxygen Species, modeling, dynamic Flux Balance Analysis
Ladeira, Courelas da Silva Ana Rita [Verfasser] y Martina [Akademischer Betreuer] Muckenthaler. "Citrate Defines a Regulatory Link Between Energy Metabolism and the Liver Hormone Hepcidin / Ana Rita Ladeira Courelas da Silva ; Betreuer: Martina Muckenthaler". Heidelberg : Universitätsbibliothek Heidelberg, 2017. http://d-nb.info/1180985338/34.
Texto completoEicher, Camille. "Adaptive evolution and acid tolerance of the wine bacterium Oenococcus oeni". Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. https://nuxeo.u-bourgogne.fr/nuxeo/site/esupversions/8f1a0519-c564-4cfe-ae5a-1e0bc656416c.
Texto completoOenococcus oeni is the wine bacterium responsible for malolactic fermentation in wine. This second fermentation step reduces total acidity, bringing roundness, softness and microbiological stability to the wine. Nevertheless, wine represents a harsh environment for the development of microorganisms, combining several stress factors that can seriously compromise malolactic fermentation. Particular attention was paid to acid stress, with the aim of identifying unknown mechanisms involved in the response of O. oeni to this stress. Therefore, two experimental evolutions were conducted on two different strains of this bacterium to adapt cells to low pH in order to improve their acid tolerance. It resulted in the appearance of mutations that were identified by whole genome sequencing of the evolved populations obtained.The first experiment conducted on ATCC BAA-1163 revealed the fixation of mutations in the citrate locus of all evolved populations. Therefore, citrate metabolism in O. oeni was extensively studied during this PhD. The results highlighted that a modulation of citrate consumption rate can improve acid tolerance of O. oeni. In addition, the mechanisms involved in the regulation of citrate locus expression in this bacterium were explored, revealing the function of the transcriptional regulator CitR and the involvement of an antisense RNA. A study of the global carbon metabolism of strains from different origins also showed a great diversity between them, which could be correlated to their ecosystems and comforted the link between citrate consumption and acid tolerance. Finally, the second adaptive evolution carried out on the commercial strain IOEB_S450 revealed the acquisition of mutations in different genes including the malate locus and opens the way to new research opportunities
Hanse, Marine. "Rôle du récepteur aux lipoprotéines, LSR, dans la régulation du transport et de la distribution des lipides alimentaires". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL086N/document.
Texto completoThe hepatic lipoprotein receptor LSR is involved in the clearance of triglyceride-rich lipoproteins including chylomicrons remnants during the post-prandial phase. Reduced LSR protein expression in mice (LSR+/-) is associated with dyslipidemia and increased postprandial lipemia; these mice exhibit increased weight gain with aging or when placed under a high-fat diet. In order to better understand the regulation of the distribution of dietary lipids, we looked for factors that could regulate LSR protein levels. Leptin is a hormone secreted by the adipose tissue that is a centrally-acting satiety factor, and was demonstrated to modulate LSR mRNA and protein expression through the modulation of transcription of the gene lsr. Leptin has been reported be involved in the control of lipogenesis through SREBP-1c. Using Garcinia cambogia extract containing an inhibitor of ATP citrate lyase, we demonstrated that there is an important link between lipogenic enzymes and LSR protein levels and with other lipoprotein receptors that provides the means to maintain a balance between endogenous lipid synthesis and dietary intake of exogenous lipids. When exogenous lipid intake is increased in the form of a high-fat diet, mice exhibited a decrease in hepatic lipogenic enzymes expression, but a deficiency of LSR led to increased lipid content in the peripheral tissues. These results suggest the presence of mechanisms for the maintenance for the balance between lipogenesis (de novo endogenous lipid synthesis), lipolysis (lipids used as energy substrate), and lipid storage through an important link between lipogenic enzymes and LSR
Hall-Ponselè, Andrew M. "Genetic engineering of the primary/secondary metabolic interface in tobacco BY-2 cells". Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:be5a3ee3-33c7-455c-b043-409987395f98.
Texto completoMorgan, Megan Jayne. "Identification of molecular-genetic determinants of quality traits of tomato fruit". Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:662d8b1e-70cf-44fb-9ed3-46dcacc39bad.
Texto completoJeremias, Juliana Toloi [UNESP]. "Balanço de macroelementos da dieta e supersaturação relativa da urina para oxalato de cálcio, equilíbrio ácido-básico e metabolismo ósseo de gatos adultos". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/101269.
Texto completoA composição mineral da dieta influencia as características da urina de gatos, estando envolvida no desenvolvimento e prevenção de urolitíases. Diante disso, em um primeiro experimento, foram investigados os efeitos da manipulação mineral da dieta baseada em seu excesso de bases sobre excreção urinária de macroelementos e supersaturação relativa da urina para oxalato de cálcio (SSR OxCa). Em uma dieta basal (EB=381meq/kg) foram adicionadas quatro doses de mistura de sais aniônicos, resultando em dietas com EB de 248mEq/kg, 169mEq/kg, 115mEq/kg e -22mEq/kg. Foram utilizados 30 gatos adultos saudáveis em um delineamento inteiramente casualizado com cinco tratamentos e seis gatos por dieta. Os gatos permaneceram em gaiolas metabólicas durante sete dias de adaptação à dieta, seguidos de cinco dias de coleta total de urina (em garrafas com 100mg de timol). A urina produzida em cada período de 24 horas teve aferido seu volume, densidade e pH, concentrações de sete macroelementos, ácido úrico, citrato e oxalato. A SSR OxCa foi calculada pelo programa Equil-93.O equilíbrio ácido-básico foi estudado pela hemogasometria de sangue venoso e suas médias foram comparadas por contrastes polinomiais (P,0,05). Um segundo experimento investigou durante um período de quatro meses as consequências da ingestão de dieta com excesso de ânions sobre o equilíbrio ácido-básico, o balanço entre formação e reabsorção óssea, a excreção urinária de cálcio e a supersaturação relativa da urina para oxalato de cálcio. Foram utilizados 18 gatos adultos saudáveis em um delineamento inteiramente casualizado com três dietas (EB de 196, EB de 9 e EB de -187mEq/kg MS) e seis gatos por dieta. Foram realizados os mesmos procedimentos do experimento anterior e para a avaliação do metabolismo ósseo foi realizada a...
Food mineral composition influences the acid-base equilibrium and the characteristics of cat’s urine and is involved in the development and prevention of urolithiasis. We investigate, in the first experiment, the effects of diet mineral manipulation based on food base excess (BE) on cats mineral balance and urinary relative supersaturation for calcium oxalate (CaOx RSS). In a basal formulation for cat maintenance (BE=381mEq/kg) four dosages of a commercial mixture of acidifying salt was added, resulting in diets with BE of 248mEq/kg, 169mEq/kg, 115mEq/kg and -22mEq/kg). Thirty adult healthy cats, were used, in a completely randomized design with five treatments and six cats per diet. A 7-d adaptation phase followed 5-d of total collection of faeces and urine. Urine were pooled by cat and analyzed for density, volume, pH, Ca, P, Mg, Na, Cl, K, S, citrate and oxalate. The CaOx RSS was calculated with Equil-93. The acid-base balance was studied by blood gas analysis of venous blood and their means were compared by polynomial contrasts (P<0.05). The experiment 2 investigated over a period of four months, consequences of ingestion of diet with anions excess on acid-base balance, balance between bone formation and resorption, calcium urinary excretion and CaOx RSS. Eighteen adult healthy cats, were used, in a completely randomized design with three treatments (BE of 196, BE of 9 and BE of -187 mEq/kg) and six cats per diet. The same procedures were performed in the previous experiment and the assessment of bone metabolism was performed by bone densitometry (DEXA) and serum markers carboxy terminal telopeptide type 1 (CTX-1) and bone alkaline phosphatase (BAP). The addition of salt mixture resulted in dose-dependent reduction of the pH of urine (p <0.0001) and not altered the volume and density of cat's urine... (Complete abstract click electronic access below)
Jeremias, Juliana Toloi. "Balanço de macroelementos da dieta e supersaturação relativa da urina para oxalato de cálcio, equilíbrio ácido-básico e metabolismo ósseo de gatos adultos /". Jaboticabal, 2013. http://hdl.handle.net/11449/101269.
Texto completoBanca: Áureo Evangelista Santana
Banca: Márcia Mery Kogika
Banca: Ricardo Souza Vasconcellos
Banca: Márcio Antônio Brunetto
Resumo: A composição mineral da dieta influencia as características da urina de gatos, estando envolvida no desenvolvimento e prevenção de urolitíases. Diante disso, em um primeiro experimento, foram investigados os efeitos da manipulação mineral da dieta baseada em seu excesso de bases sobre excreção urinária de macroelementos e supersaturação relativa da urina para oxalato de cálcio (SSR OxCa). Em uma dieta basal (EB=381meq/kg) foram adicionadas quatro doses de mistura de sais aniônicos, resultando em dietas com EB de 248mEq/kg, 169mEq/kg, 115mEq/kg e -22mEq/kg. Foram utilizados 30 gatos adultos saudáveis em um delineamento inteiramente casualizado com cinco tratamentos e seis gatos por dieta. Os gatos permaneceram em gaiolas metabólicas durante sete dias de adaptação à dieta, seguidos de cinco dias de coleta total de urina (em garrafas com 100mg de timol). A urina produzida em cada período de 24 horas teve aferido seu volume, densidade e pH, concentrações de sete macroelementos, ácido úrico, citrato e oxalato. A SSR OxCa foi calculada pelo programa Equil-93.O equilíbrio ácido-básico foi estudado pela hemogasometria de sangue venoso e suas médias foram comparadas por contrastes polinomiais (P,0,05). Um segundo experimento investigou durante um período de quatro meses as consequências da ingestão de dieta com excesso de ânions sobre o equilíbrio ácido-básico, o balanço entre formação e reabsorção óssea, a excreção urinária de cálcio e a supersaturação relativa da urina para oxalato de cálcio. Foram utilizados 18 gatos adultos saudáveis em um delineamento inteiramente casualizado com três dietas (EB de 196, EB de 9 e EB de -187mEq/kg MS) e seis gatos por dieta. Foram realizados os mesmos procedimentos do experimento anterior e para a avaliação do metabolismo ósseo foi realizada a... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Food mineral composition influences the acid-base equilibrium and the characteristics of cat's urine and is involved in the development and prevention of urolithiasis. We investigate, in the first experiment, the effects of diet mineral manipulation based on food base excess (BE) on cats mineral balance and urinary relative supersaturation for calcium oxalate (CaOx RSS). In a basal formulation for cat maintenance (BE=381mEq/kg) four dosages of a commercial mixture of acidifying salt was added, resulting in diets with BE of 248mEq/kg, 169mEq/kg, 115mEq/kg and -22mEq/kg). Thirty adult healthy cats, were used, in a completely randomized design with five treatments and six cats per diet. A 7-d adaptation phase followed 5-d of total collection of faeces and urine. Urine were pooled by cat and analyzed for density, volume, pH, Ca, P, Mg, Na, Cl, K, S, citrate and oxalate. The CaOx RSS was calculated with Equil-93. The acid-base balance was studied by blood gas analysis of venous blood and their means were compared by polynomial contrasts (P<0.05). The experiment 2 investigated over a period of four months, consequences of ingestion of diet with anions excess on acid-base balance, balance between bone formation and resorption, calcium urinary excretion and CaOx RSS. Eighteen adult healthy cats, were used, in a completely randomized design with three treatments (BE of 196, BE of 9 and BE of -187 mEq/kg) and six cats per diet. The same procedures were performed in the previous experiment and the assessment of bone metabolism was performed by bone densitometry (DEXA) and serum markers carboxy terminal telopeptide type 1 (CTX-1) and bone alkaline phosphatase (BAP). The addition of salt mixture resulted in dose-dependent reduction of the pH of urine (p <0.0001) and not altered the volume and density of cat's urine... (Complete abstract click electronic access below)
Doutor
Muir, Jacqueline M. "Citrate synthase from the hyperthermophilic archaeon, Pyrococcus furiosus". Thesis, University of Bath, 1995. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260247.
Texto completoGOUPRY, STEPHANE. "Etude par spectrometrie de masse de rapport isotopique du 1 3c du co-metabolisme citrate-glucose chez une bacterie lactique". Nantes, 2001. http://www.theses.fr/2001NANT2009.
Texto completoSiqueira, Joseilma Luciana Neves. "Alterações estruturais e metabólicas induzidas por citrato em células tumorais (MCF-7) e não tumorais (Fibroblastos) in vitro". reponame:Repositório Institucional da UnB, 2016. http://repositorio.unb.br/handle/10482/22156.
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O citrato é um metabólito intermediário do ciclo de Krebs que possui função alostérica. Quando em altas concentrações, esta molécula modula a glicólise por meio da inibição da atividade da enzima fosfofrutoquinase no citoplasma. As células de câncer apresentam reprogramação do seu metabolismo energético, produzindo energia, preferencialmente, por via glicolítica. Esta estratégia pode ser consequência de privação de oxigênio no microambiente do tumor; da rápida obtenção de energia, quando comparada à fosforilação oxidativa; de disfunção mitocondrial; ou mesmo da manutenção da homeostase mitocondrial, preservando a organela de estresse oxidativo. Nesse sentido, o citrato pode ser explorado como potencial agente antitumoral, atuando em processos-chave do funcionamento das células neoplásicas. O objetivo deste trabalho foi investigar alterações estruturais e metabólicas induzidas por citrato em células da linhagem tumoral MCF-7 (adenocarcinoma mamário humano) e em células normais (cultura primária de fibroblastos derivados de polpa dentária humana). Ensaios de citotoxicidade por meio do método colorimétrico MTT demonstraram redução da viabilidade dos dois tipos celulares de maneira dependente do tempo e da concentração do tratamento. O citrato foi mais citotóxico em células MCF-7 do que em fibroblastos na concentração de 20 mM e nos tempos de 24 e 48 h. O teor de citrato nas células MCF-7 é elevado no grupo controle e o tratamento não reduziu a produção de lactato. Foi observado inibição da atividade da enzima fosfofrutoquinase das células MCF-7 tratadas com citrato. Análises morfométricas apontaram alterações ultraestruturais das mitocôndrias em fibroblastos, o que sugere adaptação ao estresse celular produzido pelo tratamento. Não foi observado alteração de potencial de membrana mitocondrial em ambas as células após tratamento. No entanto, MCF-7 apresentou formação de espécies reativas de oxigênio. __________________________________________________________________________________________________ ABSTRACT
Citrate is an intermediate metabolite in the Krebs cycle that has allosteric function. When this molecule is present in high concentrations, it modulates the glycolysis through inhibition of the enzyme phosphofructokinase activity in the cytoplasm. Cancer cells exhibit metabolic reprogramming to the energy production preferably by glycolytic pathway. This strategy may result from oxygen deprivation in the tumor microenvironment; the rapid achievement of energy compared to oxidative phosphorylation; mitochondrial dysfunction; or even the maintenance of mitochondrial homeostasis, preserving organelle against oxidative stress. Therefore, the citrate can be explored as a potential antitumor agent, working in the key processes of cellular functions of the cancer cells. The objective of this study was to investigate structural and metabolic changes induced by citrate in tumor cell line MCF-7 (human breast adenocarcinoma) and normal cells (fibroblasts from human dental pulp). Cytotoxicity assays using the MTT colorimetric method performed in three independent experiments, demonstrated that citrate reduced the viability of both cell types in a manner dependent on the time and concentration of the treatment. Citrate was more cytotoxic in MCF-7 cells than in fibroblasts in a concentration of 20 mM at 24 and 48 h. The citrate content in MCF-7 cells is elevated in the control group and the treatment did not reduce the production of lactate. It was observed a reduction in the activity of the enzyme phosphofructokinase MCF-7 cells treated with citrate. Morphometric analysis showed ultrastructural changes of mitochondria in fibroblasts. These changes suggest adaptation to cellular stress produced by the treatment. There was no alteration in mitochondrial membrane potential in both cells after treatment. However, MCF-7 showed formation of reactive oxygen species.
Baracat, Emílio Carlos Elias 1959. "Esvaziamento gastrico de uma solução de citrato de sodio em ratos com acidose metabolica induzida por cloreto de amonio". [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/308879.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: O objetivo do presente trabalho foi estudar um modelo de desidratação por privação de água e o esvaziamento gástrico de líquidos em ratos desidratados. Foram utilizados ratos Wistar (n=380) para o estudo de um modelo de privação de água (n=80) e para o estudo do esvaziamento gástrico das soluções (n=300). No primeiro grupo, os animais permaneceram em privação de água por periodos de 24 (n=10), 48 (n=lO) e 72 horas (n=10), comparados com controles (n=15), com acesso à água. A seguir, no estudo da recuperação da desidratação (n=35), utilizou-se o periodo de privação por 72 horas, sendo que, no tempo de 67 horas de privação, água foi oferecida por 60 minutos (n=15) e 120 minutos (n=15), enquanto controles (n=5) permaneceram sem acesso à água. Foram determinados perda de peso, hematócrito e densidade plasmática em cada animal. No estudo do esvaziamento gástrico, foram estudadas três refeições de prova, salina (n=30), água (n=30) e solução reidratante da OMS (n=30), nos tempos de privação de 24, 48 e 72 horas. O mesmo número de animais foi utilizado para composição dos gruposcontroles. A seguir, utilizando o tempo de privação de 72 horas, determinou-se o esvaziamento gástrico da solução reidratante (n=lO) e de água (n=10), com oferta de água por 60 minutos no tempo de 67 horas de privação. O mesmo procedimento foi usado para as soluções reidratante (n=10) e glico-salina (n=lO), com oferta de água por 120 minutos. Nos dois estudos foram utilizados o mesmo númere de animais-controles, com privação total e sem privação de água. No modelo de desidratação, houve diferença estatisticamente significativa nos três parâmetros estudados (perda de peso, hematócrito e densidade plasmática), entre os animais do grupo de estudo e de controle, quando se utilizaram os tempos de privação de 48 e 72 horas, sendo mais pronunciadas neste último (p<0,05). Na recuperação da desidratação, após privação de água por 67 horas e oferta da mesma por 60 minutos, ocorreu uma diminuição progressiva dos valores de perda de peso, hematócrito e densidade plasmática, avaliados com 72 horas do início do estudo. Houve tendência à normalização quando a oferta de água se deu por 120 minutos
Abstract: Os valores da retenção gástrica de salina e de água foram inferiores aos da solução reidratante, nos três tempos estudados. Não houve diferença nas medidas de retenção gástrica entre os grupos de estudo com privação de água e os controles, exceto para as refeições de prova de água e solução reidratante, no tempo de privação de 72 horas, que mostraram retarde de esvaziamento gástrico (p<0,05). No grupo de animais com oferta parcial de água por 60 minutos, no tempo de privação de 67 horas, observou-se uma recuperação do padrão de esvaziamento gástrico da água em relação ao controle, avaliado com 72 horas do início do estudo, mantendo-se o retarde da solução reidratante (p<0,02). No esvaziamento gástrico da solução reidratante e glico-salina, com oferta parcial de água por 120 minutos, no tempo de 67 horas de privação, observou-se uma tendência de retarde das refeições de prova, avaliado 72 horas após o início do estudo (p=0,04). Nos estados de desidratação provocados por privação de água, sem mudança ou com alterações pequenas do conteúdo eletrolítico corporal, a solução reidratante mostrou retarde de esvaziamento gástrico, após reidratação com água. Por outro lado, a água, na situação do animal reidratado, mostrou esvaziamento gástrico semelhante ao grupocontrole. Neste estudo, há indicações de que os mecanismos de controle em que participam receptores na mucosa duodenal, e que interferem na motilidade gástrica, estão alterados na desidratação por privação de água, em ratos
Mestrado
Pediatria
Doutor em Saude da Criança e do Adolescente
Hudson, Erica M. "Determining the usefulness of aerobic and anaerobic enzyme assays as proxies for rockfish ecological data". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002750.
Texto completoSoares, Andressa Heimbecher. "Hipogonadismo associado à obesidade: efeitos do tratamento com citrato de clomifeno". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5135/tde-13062018-074535/.
Texto completoINTRODUCTION: Obesity can cause secondary hypogonadism in man. The standard testosterone replacement therapy (TRT) improves metabolic parameters but can lead to infertility. Only recently TRT was not clearly associated with adverse cardiovascular (CV) events, but its impacts on endothelial function are still controversial. AIM: To evaluate the effects of Clomiphene Citrate (CC) in out clinic young man with obesity related hypogonadism: total testosterone (TT) <= 300 ng/dL on two occasions, positive symptoms in ADAM questionnaire, Luteinizing Hormone (LH) low or inappropriate normal (RV: 1.7-8.6 IU/liter). METHODS: This is a randomized, double blind, placebo-controlled, parallel group, single-center study. Seventy eight patients aged 36.5±7.8 years, Body mass index (BMI) 46.2±8.5 kg/m2 were randomized (1:1) to receive CC 50 mg or Placebo (PLB) during 12 weeks. MAIN OUTCOME MEASURES: 1) Clinical symptomology: ADAM Questionnaire, number of sexual intercourses and satisfaction with sexual life; 2) Hormonal monitoring: serum TT, Free testosterone, Estradiol (E2), LH and Follicle-stimulating hormone (FSH), SHBG, TT/E2 ratio; 3) Body composition and anthropometric measurements: BMI, waist circumference (WC) and Bioelectric Impedance analysis parameters; 4) Metabolic response parameters: systolic and diastolic blood pressure, fasting blood glucose (FBG), glycated hemoglobin (HbA1c), serum cholesterol and fractions, triglycerides; 5) CV assessment by endothelial function parameters: Flowmediated dilatation of the brachial artery (FMDAB), circulating levels of sICAM-1, sVCAM-1, E-selectin and flow cytometry endothelial progenitor cells (EPCs); 6) Adverse outcomes: Hematocrit, serum Prostate-Specific Antigen (PSA), International Prostate Symptom Score (I-PSS), Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) and Selfreported Adverse Effects. RESULTS: Two groups were similar with regard to age (CC: 35.5±7.8 years; PLB: 35.6±7.8; P=0.951), BMI (CC: 45.5±11.3 kg/m2; PLB: 47.2±9.6; P=0.470), WC (CC: 137.5±17.9 cm; PLB: 140.2±19.6; P=0.526) and total testosterone (CC: 225.8±70.0 ng/dL; PLB: 216.0±72.1; P=0.543) in baseline data. There was an improvement in one sexual complaint (weaker erections) (P < 0.001) and there were significant improvements (P < 0.001) in TT, Free Testosterone, E2, LH, FSH and SHBG in CC group (vs. PLB). There was a gain in lean mass (P < 0.001), free fat mass (P=0.004) and muscle mass (P < 0.001). CC reduced HDL compared to PLB (P < 0.001) and showed no effect in other metabolic parameters. No statistical significance was seen in CV parameters. CC reduced ALT (P < 0.001) and increased PSA (P=0.023). CONCLUSIONS: CC was effective in increase hormonal response parametersand improved one sexual complaint (weaker erections). Despite body composition changes, CC did not improved metabolic profile and lowered LDL cholesterol. CC showed no adverse response in CV parameters. CC treatment for HG appears to be an effective alternative in young obese men wishing to preserve their fertility but long-term follow-up trials to better analyze the metabolic profile and CV outcomes are needed
DeMoranville, Kristen J. "CHARACTERIZATION AND MOLECULAR REGULATION OF METABOLIC AND MUSCLE FLEXIBILITY IN A NEOTROPICAL MIGRANT, DUMETELLA CAROLINENSIS (GRAY CATBIRD)". Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1435874292.
Texto completoSilva, Júlio César Rodrigues Lopes. "Produção de biomassa, análise sensorial de chás, caracterização química do óleo essencial por cromatografia gasosa uni e bidimensional abrangente de clones selecionados de Lippia alba (Mill.) N. E. Br quimiotipo citral /". Botucatu, 2019. http://hdl.handle.net/11449/181545.
Texto completoBanca: Beatriz Helena Lameiro de Noronha Sales Maia
Banca: Filipe Pereira Giardini Bonfim
Resumo: Lippia alba (Mill.) N.E.Br, pertencente à família Verbenaceae é uma planta medicinal amplamente distribuída na América do Sul. A composição química do óleo essencial da espécie, a qual derivam suas propriedades terapêuticas mostra-se variável, com divisão em quimiotipos. Entre eles, o quimiotipo citral destaca-se pelas ações calmante e ansiolítica, sendo suas folhas empregadas na medicina popular na forma de chá. Dessa forma, visando o potencial uso econômico de Lippia alba, este estudo teve como objetivos avaliar clones de Lippia alba do quimiotipo citral quanto a produtividade de biomassa e óleo essencial, perfil sensorial do chá e composição química do óleo essencial pelas técnicas de cromatografia gasosa unidimensional (CG) e bidimensional abrangente (CG×CG). Entre os clones, dois mostraram-se promissores para inserção em sistemas de produção, com foco em maior produção de biomassa e óleo essencial. Os perfis químicos dos óleos essenciais dos clones são variáveis entre si. O emprego do sistema CG×CG resultou em maior capacidade de detecção dos constituintes dos óleos essenciais. Ao todo foram identificadas 47 substâncias por CG×CG, contra 26 no CG. A maior sensibilidade e resolução fazem do sistema CG×CG uma importante ferramenta metabolômica no estudo dos constituintes voláteis de Lippia alba. Os clones X6M?C e X6M7 se destacaram quanto as características sensoriais de aroma e sabor, com potencial de inclusão na indústria alimentícia na forma de chá.
Abstract: Lippia alba (Mill.) N.E.Br, from the Verbanaceae family is a medicinal plant widely distributed in the South America. The species's essential oil chemical composition, which derives its therapeutic properties, shows itself as variable, with division in chemotypes. Among them, the citral chemotype highlights itself for the soothing and anxiolytic actions, being its leaves used in the popular medicine in the form of tea. Thus, aiming the potential economic use of the Lippia alba, this work has as objectives evaluate the clones of the citral chemotype of Lippia alba in terms of productivity of biomass and essential oil, sensorial profile and chemical composition of the essential oil by using the one-dimensional gas Chromatography (CG) and comprehensive twodimensional gas chromatography(CGxCG). Among the clone, two stood out as promising to insertion in production systems, with focus on a bigger production of biomass and essential oil. The chemical profiles of the clones's essential oil are variable among themselves. The use of the CGxCG system have resulted in a bigger capacity of identification of the essential oils constituents. Altogether, 47 substances have been identified by CGxCG, against 26 in CG. The better sensibility and resolution are part of the CGxCG, an important metabolomics tool of the volatile constituents of Lippia alba. The X6M?C e X6M7 clones stood out in terms of sensorial features of flavor, with potential of inclusion in the food industry in the form of tea.
Mestre
Ecelbarger, Carolyn Mary. "Effects of aging, dietary citrate, kidney function and tissue turnover on aluminum metabolism in rats". 1992. http://catalog.hathitrust.org/api/volumes/oclc/28738985.html.
Texto completoRoss, Kerry Lynn. "Iron regulation of mitochondrial aconitase synthesis : a role for iron regulatory proteins (IRP) in cellular citrate metabolism /". 2002. http://www.library.wisc.edu/databases/connect/dissertations.html.
Texto completoDavies, Rhiannon. "Allometric Scaling in Centrarchid Fish: Origins of Intra- and Inter-specific Variation in Oxidative and Glycolytic Enzyme Levels in Muscle". Thesis, 2007. http://hdl.handle.net/1974/897.
Texto completoThesis (Master, Biology) -- Queen's University, 2007-10-31 11:55:28.757
Sienkiewicz-Porzucek, Agata [Verfasser]. "Evaluation of the role of mitochondrial citrate synthase, mitochondrial and cytosolic isoforms of isocitrate dehydrogenase in tomato leaf metabolism / von Agata Sienkiewicz-Porzucek". 2009. http://d-nb.info/1002453992/34.
Texto completoCikánková, Tereza. "Vliv psychotropních látek na mitochondriální funkce". Doctoral thesis, 2020. http://www.nusl.cz/ntk/nusl-437212.
Texto completoGuay, Claudiane. "Étude de l'implication des navettes du pyruvate découlant du métabolisme mitochondrial du glucose dans la régulation de la sécrétion d'insuline par les cellules bêta pancréatiques". Thèse, 2010. http://hdl.handle.net/1866/3614.
Texto completoDiabetes is a metabolic disorder characterized by a combination of insulin resistance in peripheral tissues with an inappropriate amount of insulin secreted by the pancreatic β-cells to overcome this insulin resistance. In order to help find a cure for diabetic patients, we need to elucidate the mechanisms underlying the proper control of insulin secretion in response to glucose. In pancreatic β-cells, glucose metabolism leads to the production of metabolic coupling factors, like ATP, implicated in the regulation of insulin vesicle exocytosis. The mechanism linking ATP production by the oxidative metabolism of glucose to the triggering of insulin release that involves Ca2+ and metabolically sensitive K+ channels is relatively well known. Other mechanisms are also involved in the regulation of insulin secretion in response to glucose and other nutrients, such as fatty acids and some amino acids. Malonyl-CoA and NADPH are two metabolic coupling factors that have been suggested to be implicated in the transduction of metabolic signaling coming from glucose metabolism to control the release of insulin granules. However, the mechanisms implicated remained to be defined. The goal of the present thesis was to further our understanding of the role of the pyruvate shuttles, derived from mitochondrial glucose metabolism, in the regulation of insulin secretion. In pancreatic β-cells, pyruvate shuttles are produced by the combination of anaplerosis and cataplerosis processes and are thought to link glucose metabolism to the regulation of insulin secretion by the production metabolic coupling factors. In our first study, we wished to determine the role of the pyruvate/citrate shuttle in the regulation of glucose-induced insulin secretion. The pyruvate/citrate shuttle leads to the production in the cytoplasm of both malonyl-CoA and NADPH and also stimulates the metabolic flux through the glycolysis by re-oxidating NADH. A previous study done in the group of Dr Prentki has suggested the feasibility of the pyruvate/citrate shuttle in pancreatic β-cells. To investigate our hypothesis, we inhibited three different steps of this shuttle in INS 832/13 cells, a pancreatic β-cell line. Specifically, we repressed, using pharmacological inhibitors or RNA interference technology, the mitochondrial citrate export to the cytoplasm and the expression of malic enzyme (MEc) and ATP-citrate lyase (ACL), two key enzymes implicated in the pyruvate/citrate shuttle. The inhibition of each of those steps resulted in a reduction of glucose-induced insulin secretion. Our results underscore the importance of the pyruvate/citrate shuttle in the pancreatic β-cell signaling and the regulation of insulin secretion in response to glucose. Other research groups are also interested in studying the implication of pyruvate cycling processes in the regulation of insulin exocytosis. They suggested a role for the pyruvate/malate and the pyruvate/isocitrate/α-ketoglutarate shuttles. Therefore, three different shuttles derived from the mitochondrial glucose metabolism could be implicated in the regulation of glucose-induced insulin release. All those three shuttles can produce NADPH in the cytoplasm. In the pyruvate/malate and the pyruvate/citrate shuttles, the NADPH is formed by cytosolic malic enzyme (MEc), whereas in the pyruvate/isocitrate/α-ketoglutarate, NADPH is produced by cytosolic isocitrate dehydrogenease (IDHc). In our first study, we established the importance of MEc expression in the regulation of insulin secretion. In our second study, we wanted to investigate the importance of IDHc expression in glucose-induced insulin secretion. The reduction of IDHc expression in INS 832/13 cells stimulated insulin release in response to glucose by a mechanism independent of ATP production coming from glucose oxidative metabolism. This stimulation was also observed in isolated rat pancreatic cells. IDHc knockdown cells showed elevated glucose incorporation into fatty acids, suggesting that isocitrate metabolism could be redirected into the pyruvate/citrate shuttle in these cells. Taken together, these results suggest that IDHc is not essential for glucose-induced insulin secretion and that a compensatory mechanism, probably involving the pyruvate/citrate shuttle, explains the enhanced insulin secretion in IDHc knockdown cells . The pyruvate/citrate shuttle is the only pyruvate shuttle that is linked to the production of malonyl-CoA. Malonyl-CoA is a known inhibitor of carnitine palmitoyl transferase 1, the rate-limiting step in fatty acid oxidation. Therefore, the raising level of malonyl-CoA in response to glucose redirects the metabolism of fatty acids into the triglycerides/free fatty acids cycle which combine esterification and lipolysis processes. Previous studies done in the laboratory of Dr Prentki supported the concept that lipolysis of endogenous lipid stores is an important process for the appropriate regulation of insulin secretion. A first lipase, hormone-sensitive lipase (HSL), has been identified in pancreatic β-cells. HSL expression is important, but not sufficient, for the β-cell lipolysis activity. In a complementary study, we have investigated the role of another lipase, adipose triglyceride lipase (ATGL), in the regulation of insulin secretion in response to glucose and to fatty acids. We first demonstrated the expression and the activity of ATGL in pancreatic β-cells. Reducing ATGL expression using shRNA in INS 832/13 cells caused a reduction in insulin secretion in response to glucose and to fatty acids. Pancreatic islets from ATGL null mice also showed defect in insulin release in response to glucose and to fatty acids. The results demonstrate the importance of ATGL and intracellular lipid signaling in the regulation of insulin secretion. In conclusion, the work presented in this thesis suggests a role for the pyruvate/citrate shuttle in the regulation of insulin secretion in response to glucose. This mechanism possibly implicates the production of NADPH and malonyl-CoA in the cytoplasm. The results also points to a re-evaluation of the role of IDHc in glucose-induced insulin secretion. The precise role of IDHc in pancreatic β-cells needs to be determined. Finally, the data have also documented a role of lipolysis and ATGL in the coupling mechanisms of insulin secretion in response to both fuel and non-fuel stimuli.
Yu, Hsiang-Fu y 游象富. "Effect of lemongrass oil and citral on metabolism and toxicity of acetaminophen in rats". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/2k68jj.
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