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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.
1

The 'methanol oxidase' system in an acidophilic methylotroph, Acetobacter methanolicus

Chan, Hak Tak Claude January 1990 (has links)
No description available.
2

Studies on the cytochrome P450←c←a←m enzyme system

Westlake, Andrew C. G. January 1997 (has links)
No description available.
3

Investigation into electron transfer to the periplasm for c-type cytochrome biogenesis

Bushell, K. Mark W. January 2002 (has links)
No description available.
4

The modification of electrode surfaces

Lowe, V. J. January 1987 (has links)
No description available.
5

Characterizations of the anti-obesity and anti-adipogenic effects of the limonoid prieurianin

Saunders, Rudel Anton. January 2010 (has links)
Dissertation (Ph.D.)--University of Toledo, 2010. / "Submitted to the Graduate Faculty as partial fulfillment of the requirement for the Doctoral of Philosophy Degree in Biomedical Sciences." Title from title page of PDF document. "A Dissertation entitled"--at head of title. Bibliography: p. 80-98.
6

Expression pattern of GPI-anchored non-specific lipid transfer proteins in Physcomitrella patens

Höglund, Andrey January 2011 (has links)
During the water-to-land transition, that occurred approximately 450 MYA, novel habitats wererevealed to the emerging plants. This terrestrial habitat was a harsh environment compared to theaquatic, with shifting substrate content, irregular supply of water, damaging UV-radiation andrapid fluctuating temperatures. Non-specific lipid transfer proteins (nsLTP) are today only foundin the land living plants and not in the green algae. This suggests that these genes might haveevolved to help the plants cope with the stressful conditions. In this study the expression patternhas been analysed of the nsLTPs in the moss Physcomitrella patens during the possible conditionsthat raised during the water-to-land transition. The moss was exposed to salt, UV-B, drought, copper, cold and osmotic stress. Quantitative real-time PCR was used to analyse the transcription levels. I found that six genes were upregulated during either cold, dehydration or UV-B stress. This suggest that these genes are involved in the plant defense against these abiotic stresse
7

Lipid-Transfer-Proteine aus Arabidopsis thaliana - physiologische und molekulare Funktionsanalyse

Jülke, Sabine 18 February 2013 (has links) (PDF)
Die durch den obligat biotrophen Protisten Plasmodiophora brassicae hervorgerufene Pflanzenkrankheit Kohlhernie verursacht weltweit hohe ökonomische Verluste. Bis heute gibt es keine effektiven Möglichkeiten, diese Pflanzenkrankheit zu bekämpfen. Eine Analyse der Genexpression in infizierten Wurzeln im Vergleich zu nicht infizierten Wurzeln ergab, dass die Gene für Lipid-Transfer-Proteine während der gesamten Krankheitsentwicklung differentiell reguliert sind. Über die Funktionen von Lipid-Transfer-Proteinen in Pflanzen wird noch spekuliert. Diskutiert wird dabei eine Funktion bei der Anpassung an verschiedene abiotische Stressfaktoren, bei der Pathogenabwehr sowie bei dem Transfer von Lipiden. In dieser Arbeit wurden transgene Pflanzen generiert, in denen die pathogenbedingte LTP-Genregulation umgekehrt ist. Es wurden transgene A. thaliana Pflanzen erzeugt, die die Gene LTP1, LTP3, LTP4, AT1G12090 sowie AT2G18370 überexprimieren und die Genexpression von AT4G33550 sowie AT1G62510 reprimieren. Die Regulation der LTP-Genexpression erfolgte dabei durch den wurzel- und keimlingsspezifischen Promotor Pyk10. Zusätzlich wurden in dieser Arbeit auch T-DNA-Insertionsmutanten für die Gene AT1G12090, AT2G18370, AT3G22620, AT5G05960, LTP3 sowie LTP4 untersucht. Mittels semiquantitativer Expressionsanalyse konnte die Modulation der LTP-Genexpression in den LTP-Mutanten bestätigt werden. Darüber hinaus konnte gezeigt werden, dass die Modulation der Expression eines LTP-Gens auch die Expression anderer LTP-Gene beeinflusst. Die phytopathologischen Analysen der LTP-Mutanten hinsichtlich der Entwicklung der Pflanzenkrankheit Kohlhernie ergab, dass die Überexpression der Gene LTP1, LTP3 sowie AT2G18370 und die Repression der Expression von AT1G62510 eine verringerte Anfälligkeit für diese Krankheit bewirkt. Die verstärkte Expression der Gene LTP1, LTP3, LTP4, AT1G12090 sowie AT2G18370 resultiert außerdem in einer verringerten Symptomentwicklung infolge einer Pseudomonas syringae-Infektion. Die verringerte Expression des Gens AT4G33550 führt hingegen zu einer größeren Anfälligkeit für eine P. brassicae Infektion; die Infektion mit P. syringae wird dadurch aber nicht beeinflusst. Die physiologische Charakterisierung der LTP-Mutanten umfasste die Analyse des Pflanzenwachstums unter Salzstress bzw. osmotischem Stress sowie die Entwicklung der Seneszenz in abgetrennten Rosettenblättern. Es konnte gezeigt werden, dass die Gene LTP1, LTP3, LTP4, AT4G33550 sowie AT1G62510 bei der Anpassung an Salzstress sowie die Gene LTP3, AT3G22620, AT4G33550 und AT1G62510 bei der Anpassung an osmotischen Stress eine Rolle spielen. Durch die Modulation der Expression der genannten Gene wird das Wachstum unter diesen Stressbedingungen sowohl positiv als auch negativ beeinflusst. Die Entwicklung der Seneszenz wird ebenfalls durch eine veränderte LTP-Genexpression (LTP1, LTP3, LTP4, AT3G22620 sowie AT4G33550) beeinflusst. Für die biochemische Charakterisierung wurden die LTP-Gene aus A. thaliana mit einem Fusionspartner in E. coli exprimiert und die resultierenden Fusionsproteine gereinigt. Diese wurden nach Abspalten des Fusionspartners hinsichtlich ihrer antimikrobiellen Aktivität und auf die Fähigkeit, Calmodulin zu binden, untersucht. Für die gereinigten Lipid-Transfer-Proteine LTP1, LTP3, LTP4, AT2G18370 sowie AT1G62510 konnte unter den bisher getesteten Versuchsbedingungen keine antimikrobielle Aktivität nachgewiesen werden. Für die Proteine LTP1, LTP3 und LTP4 konnte eine calciumunabhängige Calmodulin-Bindung nachgewiesen werden. Die Ergebnisse dieser Versuche ermöglichen keine Aussage bezüglich der genauen Funktion der einzelnen Lipid-Transfer-Proteine, geben aber Hinweise darauf, dass diese bei den entsprechenden Stress-Vorgängen eine Rolle spielen. Welche Funktion sie dabei genau erfüllen, muss in weiterführenden Analysen untersucht werden.
8

A expressão da proteína de transferência de colesteril éster (CETP) modula a adiposidade e a expressão de genes envolvidos em lipólise e lipogênese / Cholesteryl ester transfer protein (CETP) expression modulates adiposity and expression of genes involved in lipolysis and lipogenesis

Patrício, Patrícia Riva 17 August 2018 (has links)
Orientador: Helena Coutinho Franco de Oliveira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-17T04:29:13Z (GMT). No. of bitstreams: 1 Patricio_PatriciaRiva_D.pdf: 4980020 bytes, checksum: e474966c1b7c224e3d8de5468871eefc (MD5) Previous issue date: 2010 / Resumo: A CETP é uma proteína plasmática que promove a transferência de lípides entre lipoproteínas, causando redução de HDL-colesterol e, portanto, aumento do risco de aterosclerose. Neste trabalho, investigamos o efeito da expressão desta proteína sobre a adiposidade e a expressão diferencial de genes em dois modelos animais. Inicialmente, comparamos camundongos transgênicos para a CETP humana (Tg) e controles irmãos não-transgênicos (NTg), que não expressam esta proteína. Verificamos que os camundongos CETP-Tg apresentaram redução do peso corporal, dos níveis plasmáticos de leptina, da massa dos depósitos de gordura perigonadal e subcutâneo e da área dos adipócitos. Também observamos que a expressão do RNAm da CETP é maior no tecido adiposo subcutâneo que no perigonadal. Quando comparados aos controles, os animais CETP-Tg tiveram as concentrações de RNAm no depósito perigonadal alteradas: apresentaram redução do fator de transcrição SREBP2 e da lipoproteína lipase e aumento da proteína quinase dependente de AMP (AMPK). Em relação ao tecido subcutâneo, houve diminuição do fator de transcrição PPAR_ e aumento da lipase hormônio sensível e da AMPK. Além disso, verificou-se também uma elevação de PPAR_ no fígado das fêmeas CETP-Tg, e uma elevação da lipase hepática no fígado de machos CETP-Tg. Em um segundo estudo, hamsters Golden Syrian, que expressam naturalmente a CETP, foram utilizados para confirmar se a inibição da CETP afetaria a adiposidade. Tratamento com anticorpo monoclonal neutralizante da CETP (TP2) durante um mês resultou em 70% de redução da atividade plasmática da proteína e em aumentos significativos de ganho de peso, massa de tecido adiposo visceral e área do adipócito, em comparação ao grupo controle (tratado com IgG irrelevante). Desta maneira, concluímos que a CETP induz a expressão diferencial de genes lipolíticos e lipogênicos no tecido adiposo, o que resulta em redução do conteúdo de gordura corporal. Esses resultados indicam, portanto, um novo papel antiadipogênico para a CETP. / Abstract: CETP is a plasma protein that promotes lipid transfer among plasma lipoproteins causing reduction of HDL-cholesterol and, thus, increases the risk of atherosclerosis. In this work we investigated the effect of CETP expression on differential gene expression and adiposity in two animal models. Human CETP expressing transgenic (Tg) mice and control CETP non-expressing littermates were compared. CETP-Tg mice had reduced body weight, plasma leptin levels, perigonadal and subcutaneous fat depots and adipocyte area. We also observed that CETP mRNA levels were higher in subcutaneous than in perigonadal adipose tissue. As compared to controls, CETP-Tg had altered tissue mRNA levels in the perigonadal adipose tissue: reduction of SREBP2 and lipoprotein lipase and elevation in AMPK. Regarding subcutaneous depot, there was a decrease in PPAR_ and marked elevation of hormone sensitive lipase and AMPK. In addition, an elevation in liver PPAR_ was found in female and hepatic lipase in male CETP Tg mice. Naturally CETP expressing Golden Syrian hamsters were used to confirm whether the inhibition of CETP would affect adiposity. Treatment with a neutralizing CETP monoclonal antibody (TP2) during one month resulted in 70% reduction in plasma CETP activity and significant increases in weight gain, visceral adipose tissue mass and adipocyte area, as compared to the control group (irrelevant IgG treated). In conclusion, CETP induces differential lipolitic and lipogenic gene expression in adipose tissue, resulting in reduction of body fat content. These findings disclose a novel anti-adipogenic role for CETP. / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular
9

Lipemia pos-prandial nas alterações das atividades da proteina de tranferencia de esteres de colesterol ou da lipase hepatica em humanos e em roedores / Lipemia postrandial in the alterations of the activities in the cholesterol ester transfer protein or hepatic lipase in human and rodents

Urban, Aline 19 December 2007 (has links)
Orientador: Eliana Cotta de Faria / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-11T19:49:35Z (GMT). No. of bitstreams: 1 Urban_Aline_M.pdf: 815848 bytes, checksum: 55752c75065f47c7931dd73654d5a65d (MD5) Previous issue date: 2007 / Resumo: A resposta pós-prandial a uma sobrecarga de gordura apresenta efeitos pró-aterogênicos diretos por deposição de lipoproteínas remanescentes na parede arterial e, indiretos sobre o metabolismo de lipoproteínas ricas em triglicérides. Alterações durante a lipemia pósprandial podem estar relacionadas com as atividades das proteínas de transferência de ésteres de colesterol e da lipase hepática. Estas duas proteínas possuem papel ambíguo no desenvolvimento da aterosclerose e sua atuação sobre o metabolismo de lipoproteínas ricas em triglicérides pós-prandiais é muito pouco descrita na literatura. Estudamos as repercussões metabólicas em mulheres assintomáticas (n=28) após uma refeição oral única, líquida e rica em gordura em indivíduos apresentando deficiência primária de CETP e LH com coletas de sangue seriadas até 8h. A seleção dos casos foi feita através da determinação de valores de corte para CETP e LH, iguais ou menores aos percentis 10 ou iguais ou maiores que os percentis 90 de uma população normolipidêmica (n=129). Os indivíduos que possuem atividade das proteínas entre os percentis 10 e 90 foram selecionados como controles. A mulher que apresenta deficiência múltipla (CETP -79% e LH -88%) possui aumento da lipemia pós-prandial que foi atenuada após um ano de tratamento de reposição hormonal com Tibolona. Analisando um grupo de 6 indivíduos com um aumento médio de 33% de CETP, obtivemos curvas dos lipides pós-prandiais similares aos controles, em contraste com os relatos de casos com lipemia aumentada e deficiência de CETP. Este modelo demonstra uma ausência de um efeito de CETP na lipoproteína rica durante seu aumento moderado, provavelmente devido a falta das mudanças no transporte reverso do colesterol e igualmente a ausência dos triglicérides de um efeito direto da proteína de transferência no metabolismo lipoproteínas ricas em triglicérides. O estudo pós-prandial que usa modelos de roedores foram também realizados; observamos após uma sobrecarga oral da gordura que camundongos de ambos os sexos e ratos fêmeas apresentam lipemia pós-prandial com características similares aos seres humanos normolipidêmicos. Uma distinta resposta foi observada nos ratos machos que são mais sensíveis à dieta apresentando lipemia tardia. / Abstract: The postprandial response to a fat overload presents proatherogenic direct effects with remanescent lipoproteins deposition in arterial walls and indirect on the triglycerides-rich lipoprotein metabolism. Alterations during the postprandial lipemia are related with the activities of cholesteryl ester transfer protein and hepatic lipase. These two proteins possess ambiguous roles in the development of atherosclerosis and their performance on the triglycerides-rich lipoprotein metabolism is very scarcely described in the literature. We studied the metabolic repercussions in assimptomatics women (n=28) after a single liquid and rich in fat oral meal in individuals presenting primary deficiency of CETP and HL with serial collections of blood up to 8h. The selection of participants was made through cutoff values for CETP and HL either equal or lower or equal or higher than percentiles 10 and 90 of a normolipidemic population (n=129). The individuals that presented activities of proteins between percentiles 10 and 90 were selected as controls. In a a case-report here described a woman who presented multiple deficiencies (CETP= -79% and HL= -88%) had increased postprandial lipemia that was attenuated one year of hormonal treatment with Tibolona, a result not described yet in the literature. Analyzing a group of 6 individuals with an average CETP increase of 33%, we obtained postprandial lipids curves similar to controls, in a sharp contrast with the case report with increased lipemia and CETP deficiency. This model demonstrates an absence of a CETP effect on triglyceride rich lipoprotein during its moderate increase, probably due the lack of changes in the reverse cholesterol transport and also the absence of a direct effect of the transfer protein on triglyceride-rich lipoprotein metabolism. As well postprandial studies using rodent models were performed; we observed after an oral overload of fat that mice of both the sexes and female rats present postprandial lipemia with characteristics similar to normolipidemic humans. A distinguished response was observed in male rats that are more sensible to the diet with the presence of the delayed and late lipemia. / Mestrado / Ciencias Biomedicas / Mestre em Ciências Médicas
10

Estudo dos mecanismos envolvidos na redução de adiposidade de camundongos que super-expressam a proteína de transferência de colesteril éster (CETP) / Effects of n-3 and n-6 fatty acids on the cholesteryl ester transfer protein (CETP) expression and activity in transgenic mice

Raposo, Helena Fonseca, 1981- 25 January 2013 (has links)
Orientador: Helena Coutinho Franco de Oliveira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T05:23:31Z (GMT). No. of bitstreams: 1 Raposo_HelenaFonseca_D.pdf: 7490061 bytes, checksum: b7d93ea4b63d773168cdfcbe34c70392 (MD5) Previous issue date: 2013 / Resumo: A proteína de transferência de colesteril éster (CETP) transfere colesterol esterificado (CE) das HDL para as lipoproteínas que contêm apo B, em troca de triglicérides. Assim, a CETP promove a redução dos níveis de HDL-colesterol no plasma, aumentando o risco de aterosclerose. Recentemente, nosso grupo verificou que camundongos transgênicos que expressam a CETP (CETP-Tg) apresentam menor adiposidade que os controles não transgênicos (NTg). Neste trabalho investigamos possíveis mecanismos que expliquem a redução da adiposidade. Camundongos CETP-Tg e controles NTg (C57/BL6 background) foram tratados com dieta padrão desde o desmame até os 5 meses de idade. Camundongos CETP-Tg apresentaram redução nos depósitos de tecido adiposo (~30%). Essa redução da adiposidade não foi compensada por deposição ectópica de lipídeos no fígado ou músculo, nem foi consequência de alteração do balanço de gordura (ingestão vs. excreção). Lipogênese in vivo e em adipócitos isolados (estimada por 3H2O e 14C-acetato) foram similares entre os grupos. A retenção de lipídeos exógenos e a captação de glicose pelo fígado, músculo e tecidos adiposos (estimada após dose oral de 3H-trioleina e injeção IP de 3H-2- deoxiglicose, respectivamente) não evidenciaram nenhuma diferença entre os genótipos. No estado alimentado, a expressão da CETP aumentou (~50%) a lipólise basal in vivo e estimulada por isoproterenol em adipócitos isolados. Coerentemente, os níveis de RNAm para HSL (hormone sensitive lipase) e ATGL (adipose triglyceride lipase) estavam aumentados, assim como FATP1 (fatty acid transport protein 1). No tecido adiposo marrom, verificou-se elevação nos níveis de ATGL, FATP1 e UCP1 (uncoupling protein 1). Além disso, o conteúdo protéico do receptor beta 3 adrenérgico também estava aumentado nos extratos de membrana celular de tecido adiposo visceral e marrom dos animais CETP-Tg. A expressão da CETP também elevou em cerca de 10% a taxa metabólica corporal (VO2 e gasto energético). Conclui-se que a CETP altera a expressão e/ou função de proteínas relacionadas à lipólise e termogênese, aumentando o gasto energético global e reduzindo a massa de gordura corporal. Em conjunto, esses resultados sugerem uma nova função antiadipogênica para a CETP / Abstract: Cholesteryl ester transfer protein (CETP) is a plasma protein that mediates the exchange of triglycerides for esterified cholesterol from HDL to the apoB containing lipoproteins. In this way, CETP promotes reduction of plasma HDLcholesterol and, thus, increases the risk of atherosclerosis. Recently, we found that CETP expressing mice (CETP-Tg) presented less adipose tissue mass than nonexpressing controls. In this work we investigated possible mechanisms to explain these findings. CETP-Tg and non-transgenic (NTg) control mice (C57/BL6 background) were fed with chow diet from weaning to 5 month of age. CETP-Tg mice had reduced visceral and subcutaneous fat depots (~30%) that was not compensated by lipid ectopic deposition and could not be explained by differences in fat intake and excretion. Lipogenesis rates in vivo and in isolated adipocytes (estimated using 3H2O and 14C-acetate) were similar in both CETP-Tg and control mice. Lipid retention and glucose uptake by liver, muscle and adipose tissues (estimated after an oral dose of 3H-triolein and IP injection of 3H-deoxiglucose) showed no significant differences between groups. In the fed state, CETP group showed higher (~50%) basal lipolysis rates in vivo and in isoproterenol stimulated lipolysis rates in isolated adipocytes. In accordance, visceral adipose hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) mRNA expression were elevated, as well as fatty acid transport protein (FATP1). In brown adipose tissue, ATGL, FATP1 and uncoupling protein 1 (UCP1) were increased. Furthermore, beta 3 adrenergic receptor proteins mass were upregulated in visceral and brown adipose tissues membrane extracts. In addition, whole body energy expenditure (measured by respirometry) was found to be elevated in CETP-Tg mice (10%). In conclusion, CETP change expression and function of proteins related to lipolysis and thermogeneis, thus, increasing whole body energy expenditure and resulting in less body fat content. These findings disclose a novel anti-adipogenic role for CETP / Doutorado / Fisiologia / Doutora em Biologia Funcional e Molecular

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