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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.
271

Les effets du dalcetrapib, un inhibiteur de la protéine de transfert des esters de cholestérol (CETP), sur la structure et la fonction des lipoprotéines de haute densité (HDL) dans l’étude dal-PLAQUE2

Beaudet, Marie-Lou 10 1900 (has links)
No description available.
272

Syndrome métabolique affectant les survivants de la leucémie lymphoblastique aiguë pédiatrique : rôle et dysfonctions des lipoprotéines « HDL »

Fournier, Maryse 04 1900 (has links)
No description available.
273

Mesure de l’activité de la lécithine : cholestérol acyltransférase (LCAT), une enzyme impliquée dans la biogenèse des HDL, par chromatographie liquide - spectrométrie de masse (LC-MS)

Blanchard, Matthieu 02 1900 (has links)
No description available.
274

Characteristics and mechanisms of phosphate removal by calcium-iron layered double hydroxides and their hydrolysis products / Synthèse et transformations minéralogiques des hydroxydes doubles lamellaires calcium-fer pour l'élimination des phosphates en milieu aqueux

Al-Jaberi, Muayad 23 June 2016 (has links)
La mise au point de nouveaux matériaux pour piéger les anions phosphate présents dans les eaux usées est une des clés pour lutter contre le phénomène d’eutrophisation des eaux de surface. Au cours de cette étude, les hydroxydes doubles lamellaires contenant des ions CaII et FeIII dans les feuillets cationiques et des anions chlorure et nitrate au sein de l’espace inter-feuillets (CaFe-HDL-Cl et CaFe-HDL-NO3) ont été utilisés pour piéger les phosphates. Ces deux variantes d’HDL ont été synthétisées par trois méthodes simples de co-précipitation. La capacité de piégeage de ces matériaux a été évaluée par des expériences de sorption en « batch » à l’équilibre et des mesures de cinétique dans une gamme de pH comprise entre 4 et 12. La cinétique de piégeage du phosphate par les HDL obéit à une loi du pseudo-second ordre. Les isothermes révèlent que les HDL synthétisés avec un rapport CaII : FeIII de 2 : 1 sont les plus efficaces pour piéger les phosphates. On mesure des capacités de piégeage très élevées de l’ordre de 385 et 402 mg g-1 pour les composés CaFe-HDL-Cl et CaFe-HDL-NO3, respectivement. Les données obtenues à l’équilibre ont pu être ajustées par des isothermes de type Langmuir et/ou Freundlich. Pour des concentrations en phosphate élevées ([PO43-] ≥ 100 mg L-1), la caractérisation des solides et des liquides par diverses techniques révèlent que la HDL se dissout et libèrent des cations solubles Ca2+ qui précipitent avec les phosphates pour former l’hydroxyapatite Ca5(PO4)3OH. A ce mécanisme principal s’ajoute un mécanisme de piégeage secondaire qui est l’adsorption des phosphates par un gel ferrique dopé en ions calcium qui est lui aussi issu de la transformation minéralogique de l’HDL. A faible concentration en phosphate ([PO43-] ≥ 100 mg L-1), l’hydroxyapatite ne se forme pas et l’adsorption des phosphates par ce gel ferrique dopé en ions calcium devient le mécanisme de piégeage principal. / The development of an efficient removal material for phosphate from wastewater to prevent the eutrophication in surface waters is very important. In this study, CaIIFeIII layered double hydroxide containing chloride and nitrate as intercalated anions (CaFe-LDH-Cl and CaFe-LDH-NO3) were used as removal materials for phosphate. Both forms were designed and synthesized at different CaII: FeIII molar ratios (2:1, 3:1, and 4:1) following three simple co-precipitation methods. The materials were evaluated for the removal of phosphate by batch equilibrium sorption experiments and kinetic measurements. The efficiency of the phosphate removal from aqueous solution was investigated in the range pH 4-12. As a result, it was found that pseudo-second-order kinetic model described well the phosphate removal. The isotherms of adsorption of PO43- ions showed that CaFe-LDH-Cl and CaFe-LDH-NO3 at CaII: FeIII molar ratio of 2:1 revealed the highest rate of phosphate uptake of 385 and 402 mg g-1, respectively, comparing to other CaII: FeIII molar ratios. Equilibrium data were well fitted with Freundlich and Langmuir isotherms. In the case of high phosphate concentration ([PO43-] ≥ 100 mg L-1), the comprehensive analysis of the phosphate-uptake products with different techniques revealed that CaFe-LDH dissolve first and then released Ca2+ ions reacting with PO43- anions to form Ca5(PO4)3OH (hydroxyapatite) which is the main mechanism for phosphate removal. Also, phosphate was removed partially via a subsidiary process other than precipitation of hydroxyapatite. The excess in phosphate removal was attributed to the formation of a disordered Ca doped ferrihydrite which removed phosphate via simple surface adsorption. In the case of initial low phosphate concentration ([PO43-] < 100 mg L-1), the analysis showed that PO43- removed mainly via simple surface adsorption over disordered Ca doped ferrihydrite which was the main component in the residual solid after partial Ca2+ releasing from LDH
275

Materiais derivados de hidróxidos duplos lamelares: síntese, caracterização e aplicação em adsorção e processos avançados de oxidação / Layered double hydroxides-derived materials: synthesis, characterization and application in adsorption and advanced oxidation processes

Santos, Rodrigo Morais Menezes dos [UNESP] 15 January 2016 (has links)
Submitted by RODRIGO SANTOS (rodrigo_ilct@yahoo.com.br) on 2016-01-27T16:19:53Z No. of bitstreams: 1 Dissertação Rodrigo Morais Menezes dos Santos.pdf: 4136391 bytes, checksum: 50ec17cef563517b2a5199c9c72d9a0f (MD5) / Approved for entry into archive by Sandra Manzano de Almeida (smanzano@marilia.unesp.br) on 2016-01-27T18:53:38Z (GMT) No. of bitstreams: 2 santos_rmm_me_araiq_int.pdf: 4136391 bytes, checksum: 50ec17cef563517b2a5199c9c72d9a0f (MD5) santos_rmm_me_araiq_par.pdf: 1040758 bytes, checksum: a18d1d9fa74ec9c42cb002b3084f4a61 (MD5) / Made available in DSpace on 2016-01-27T18:53:38Z (GMT). No. of bitstreams: 2 santos_rmm_me_araiq_int.pdf: 4136391 bytes, checksum: 50ec17cef563517b2a5199c9c72d9a0f (MD5) santos_rmm_me_araiq_par.pdf: 1040758 bytes, checksum: a18d1d9fa74ec9c42cb002b3084f4a61 (MD5) Previous issue date: 2016-01-15 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A contaminação de recursos hídricos por diversos poluentes orgânicos, como os corantes têxteis, tem causado sérios problemas ambientais. Alguns processos de descontaminação utilizam materiais sólidos para adsorção/sorção, com características apropriadas para a implantação em escala industrial, apresentando alta eficiência e baixo custo. Os Processos Avançados de Oxidação (AOP), como a fotocatálise heterogênea, também têm sido empregados na descontaminação de águas, convertendo os poluentes orgânicos em substâncias mais facilmente degradáveis, inertes ou inofensivas. Materiais multifuncionais como os Hidróxidos Duplos Lamelares (HDL) e seus derivados se mostram promissores tanto em processos adsortivos como fotocatalíticos. No presente trabalho foi dado enfoque ao processo de adsorção de um azocorante têxtil, utilizando HDL do sistema ZnAl-CO3 e o óxido misto obtido no tratamento térmico a 450°C. Os materiais apresentaram características interessantes e alta capacidade de remoção do corante. As isotermas de adsorção apresentaram boa correlação com o modelo de Langmuir e o cálculo de seus parâmetros revelou que a capacidade máxima adsortiva do material calcinado foi cerca de 6 vezes superior ao material não calcinado, 1587,1 mg⋅g-1 e 261,8 mg⋅g-1, respectivamente. A maior capacidade de adsorção/sorção foi atribuída ao melhoramento das propriedades texturais e ao comportamento da “regeneração” da estrutura HDL pelo precursor calcinado. Os resultados revelaram que o controle cinético do processo é uma etapa de adsorção química, e os parâmetros termodinâmicos calculados mostraram que o processo de adsorção é espontâneo e endotérmico. Os experimentos de conversão fotocatalítica de corante mostraram que os derivados da calcinação dos HDL são materiais promissores para serem utilizados nos AOP. A formação do nanocompósito ZnAl2O4/ZnO no material calcinado a 850°C, mostrou os melhores resultados de conversão, pela estratégia de acoplamento de bandas para separação de cargas, que diminui os problemas relacionados com a recombinação dos portadores de carga, além da maior absorbância no UV. Dessa forma, os resultados obtidos mostram a multifuncionalidade desses materiais, e fornecem novas evidências sobre a reconstrução de HDL pelo “efeito memória”, tópico de intensa discussão na literatura. / The contamination of water resources by several organic pollutants, including textile dyes, which have caused serious environmental problems. Solid materials for adsorption with appropriate features to be employed in industrial scale, such as high efficiency and low cost have been used in some decontamination processes. The Advanced Oxidation Processes (AOP) including heterogeneous photocatalysis, have also been used in water treatment, converting the organic pollutants into easily degradable, inert or harmless substances. Multifunctional materials, such as the Layered Double Hydroxides (LDH) and their derivatives, show potential in both adsorptive and photocatalytic processes. In this work the textile azo dye adsorption process using a ZnAl-CO3 LDH and the mixed oxide obtained from thermal treatment at 450 °C were focused. The materials presented interesting features and high removal capacity for the dye. The adsorption isotherms showed good correlation with the Langmuir isotherm model and the calculated parameters revealed that the maximum adsorption capacity of the calcined material was about 6 times higher than the non-calcined material, 1587.1 mg⋅g-1 and 261.8 mg⋅g-1, respectively. The higher adsorption capacity was assigned to the improvement of the textural properties and to the LDH-structure recovery from the calcined precursor. The results showed kinetic control of the process is a chemical adsorption step, and the calculated thermodynamic parameters showed the adsorption process is spontaneous and endothermic. The dye photocatalytic conversion experiments presented that the derivatives of the LDH calcination are promising materials to be used in the AOP. The formation of a ZnAl2O/ZnO nanocomposite from calcination at 850 °C showed the best conversion results from the coupling semiconductors for charge separation strategy that diminish some problems associated with charge carrier recombination and its higher UV absorbance. Thus, the results show the multi-functionality of these materials, giving some light to the discussion about LDH recovery by "memory effect" that remains a topic of intense debate in the literature. / FAPESP: 2013/25043-4
276

TAB2VHDL: um ambiente de síntese lógica para máquinas de estados finitos

Tancredo, Leandro de Oliveira [UNESP] 19 September 2002 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-09-19Bitstream added on 2014-06-13T19:28:11Z : No. of bitstreams: 1 tancredo_lo_me_ilha.pdf: 1818873 bytes, checksum: ed384d89dcc56a20c364164f7beef4f2 (MD5) / Este trabalho apresenta uma nova ferramenta de síntese para projetos de sistemas digitais denominada TAB2VHDL. A partir da descrição em diagrama de transição de estados de uma máquina finita, representada no modelo de Mealy, é gerada uma descrição otimizada do sistema na linguagem de VHDL. Elimina-se dessa forma a tarefa árdua com detalhes de projeto. A TAB2VHDL foi comparada com duas outras ferramentas disponíveis comercialmente. Foram projetados diversos chip-set de códigos de transmissão digital utilizados no setor de telecomunicações. Os resultados comprovaram o desempenho satisfatório com relação ao custo de implementação, ao tempo de execução e uso de memória. / This paper presents a new synthesis tool for digital system projects called TAB2VHDL. From the description in states transition diagram of a finite machine, represented in Mealy's model, an optimized system description in VHDL language is generated. Therefore, it is eliminated an arduous task with project details. The TAB2VHDL was compared with two other available commercial tools. It was projected a sort of chip-set digital transmission codes, used in telecommunication sector. The results proved the satisfactory performance related to the implementation cost, to the time of execution and memory use.
277

Rastreamento dos fatores de risco para síndrome metabólica em adolescentes eutróficos e com excesso de peso /

Pegolo, Giovana Eliza. January 2010 (has links)
Resumo: O objetivo deste estudo foi rastrear a ocorrência de fatores de risco da síndrome metabólica em adolescentes eutróficos e com excesso de peso em dois momentos transversais, com intervalo de seis meses. A amostra foi constituída por 64 adolescentes divididos em quatro grupos: meninos eutróficos e com excesso de peso e meninas eutróficas e com excesso de peso. As variáveis investigadas foram: peso, estatura, circunferência da cintura, percentual de gordura corporal, pressão arterial, colesterol total, LDL-colesterol, HDLcolesterol , triglicerídeos, glicose, ingestão de nutrientes, número de passos diário e tempo gasto com hábitos sedentários (assistir televisão, uso de computador e videogames). A média de idade foi de 11,4 ±0,3 anos para os meninos e 11,5 ±0,3 anos para as meninas. Foi diagnosticado um caso de síndrome metabólica, mas a presença de fatores de risco foi constatada nas duas avaliações. Entre os adolescentes com excesso de peso, 56% dos meninos e 31% das meninas apresentaram obesidade abdominal na primeira avaliação e as mesmas proporções foram observadas no segundo momento. Houve aumento da incidência da proporção de adolescentes com baixa concentração de HDLcolesterol nos grupos eutróficos e com excesso de peso. Entre os adolescentes eutróficos, na segunda avaliação 44% dos meninos e 69% das meninas apresentaram HDL-colesterol inferior a 40 mg/dL. No grupo com excesso de peso, 69% dos meninos e 63% das meninas apresentaram tal condição. Houve redução significativa de HDL-colesterol acompanhada de aumento de triglicerídeos, dois parâmetros críticos no desenvolvimento da síndrome metabólica. Além disso, foi detectada correlação inversa e significativa entre triglicerídeos e HDL-colesterol nas duas avaliações. Entre os adolescentes com excesso de peso, houve aumento, em ambos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study was aimed to track risk factors of metabolic syndrome in eutrophic and overweight adolescents in two time periods, with a time interval of six months between the two periods. The sample was composed of 64 adolescents divided into four groups: eutrophic boys, overweight boys, eutrophic girls and overweight girls. The assessed variables were: weight, height, waist circumference, body fat percentage, arterial blood pressure, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, glucose, nutrient intake, number of daily steps and hours of sedentary behavior (watching TV, playing on the computer or videogames). The average age of the boys was 11.4 ±0.3 years and of the girls was 11.5 ±0.3 years. One case of metabolic syndrome was diagnosed, but the presence of risk factors was detected in both assessments. Among overweight adolescents, 56% of the boys and 31% of the girls had abdominal obesity in the first assessment and the same percentage was found in the second assessment. There was an increase in the percentage of adolescents with low HDL-cholesterol concentrations in the eutrophic and overweight groups. Among the eutrophic adolescents, in the second assessment, 44% of the boys and 69% of the girls had HDL-cholesterol lower than 40 mg/dL. In the overweight group, 69% of the boys and 63% of the girls had this condition. There was a significant reduction in HDL-cholesterol followed by an increase in the triglycerides, two critical parameters in the development of the metabolic syndrome. Besides, an inverse and significant correlation between triglycerides and HDL-cholesterol was detected in both assessments. Among overweight adolescents there was an increase, in both sexes, in the number of adolescents with the two risk factors (boys: from 12% to 44%; - girls: from 6% to 25%), due... (Complete abstract click electronic access below) / Orientador: Thaïs Borges César / Coorientador: João Bosco Faria / Banca: Ellen Cristini Freitas Araújo / Banca: Marina Vieira da Silva / Banca: Anderson Marlieri Navarro / Banca: Maria Rita Marques de Oliveira / Doutor
278

Effects of heavy alcohol intake on lipoproteins, adiponectin and cardiovascular risk

Kuusisto, S. (Sanna) 25 November 2014 (has links)
Abstract The effect of alcohol intake on the pathophysiology of atherosclerotic cardiovascular disease is controversial, especially with respect to heavy alcohol intake. The pathobiology behind atherosclerosis is a complex and multiparametric phenomenon, therefore a self-organizing map (SOM), an unsupervised learning based artificial neural network technique, was applied in the present work. This study was carried out to investigate the effect of heavy alcohol intake on the pathophysiology of atherosclerosis, including several lipoproteins and adiponectin, an adipocyte-derived cytokine that may ameliorate atherosclerosis. Firstly, the effect of heavy alcohol intake on the capacity of HDL and its subclasses (HDL2 and HDL3) to mediate cholesterol efflux from macrophages was studied. Secondly, data of ultracentrifugally isolated lipoproteins were fed into SOM analysis to investigate whether this method can find diverse lipoprotein phenotypes from the heterogeneous lipoprotein data. Thirdly, the aforementioned method was applied to multivariate data of alcohol drinkers to study whether distinct metabolic profiles are associated to heavy alcohol consumption. The results revealed that HDL2, not HDL3, of heavy alcohol drinkers had an enhanced capacity to remove cholesterol from macrophages when compared with control persons. SOM analysis enhanced the ultracentrifugally based lipoprotein data and depicted several novel lipoprotein phenotypes. In addition, lipoprotein-based SOM analysis found two distinct metabolic profiles in heavy alcohol drinkers: an anti-atherogenic and a metabolic syndrome-like profile with opposite metabolic features, such as characteristics of lipoproteins, plasma concentration of adiponectin and prevalence of metabolic syndrome. These profiles also tended to differ in their CV risk. In conclusion, the enhanced cholesterol efflux capacity of HDL2 in heavy drinkers is an anti-atherogenic change linked to alcohol drinking. However, clinically it may be important to be aware that although heavy alcohol drinkers have a low LDL-C level, they differ in their other lipoprotein measures, forming distinct phenotypes with potentially different CV risks. Finally, SOM analysis of ultracentrifugally based lipoprotein data generates in silico classification of lipoprotein particles and thereby offers a new tool for lipoprotein research. / Tiivistelmä Alkoholinkäytön vaikutus ateroskleroottisen sydän- ja verisuonitaudin patofysiologiaan on kiistanalainen, etenkin runsaan alkoholinkäytön kohdalla. Koska patobiologia ateroskleroosin taustalla on monimutkainen ilmiö, tässä työssä sovellettiin menetelmänä itseorganisoituvaa karttaa, joka on ohjaamattomaan oppimiseen perustuva neuroverkkomalli. Tutkimuksen tavoitteena oli selvittää runsaan alkoholinkäytön vaikutusta ateroskleroosin patofysiologisiin merkkiaineisiin, mukaan lukien useita lipoproteiineja sekä adiponektiini, rasvasoluperäinen sytokiini, joka voi lievittää ateroskleroosia. Ensimmäisessä osatyössä tutkittiin runsaan alkoholinkäytön vaikutusta HDL:n ja sen alafraktioiden (HDL2 ja HDL3) kykyyn poistaa kolesterolia makrofageista. Toisessa osatyössä ultrasentrifuugaukseen perustuva lipoproteiiniaineisto syötettiin itseorganisoituvaan karttaan. Työssä selvitettiin löytäisikö menetelmä erilaisia lipoproteiinifenotyyppejä heterogeenisestä aineistosta. Kolmannessa osatyössä em. menetelmää sovellettiin monimuuttuja-aineistoon, joka koostui runsaasti alkoholia käyttävistä ja verrokeista. Tutkittiin, liittyykö runsaaseen alkoholinkäyttöön erilaisia metabolisia profiileja. Tulokset osoittivat, että suurkuluttajien HDL2-hiukkasen kolesterolinpoistokyky makrofageista oli suurempi kuin verrokeilla. Itseorganisoituvaan karttaan perustuva lipoproteiinien luokittelumenetelmä löysi useita uusia lipoproteiinifenotyyppejä. Lisäksi, em. menetelmä löysi suurkuluttajilta kaksi erilaista metabolista profiilia: anti-aterogeeninen ja metabolisen syndrooman kaltainen. Näillä oli vastakkaiset metaboliset piirteet, kuten lipoproteiinien ominaisuudet, adiponektiinin pitoisuus plasmassa ja metabolisen syndrooman esiintyvyys. Profiileihin liittyi mahdollisesti myös erilainen sydän- ja verisuonitautiriski. Tutkimus osoittaa, että alkoholin suurkuluttajilla havaittu parempi HDL2:n kyky poistaa kolesterolia soluista on anti-aterogeeninen muutos, joka liittyy alkoholin käyttöön. Kliinisesti voi olla merkittävää, että vaikka alkoholin suurkuluttajilla oli pieni LDL-C pitoisuus, he jakaantuivat muiden lipoproteiiniperäisten muuttujien perusteella kahteen eri fenotyyppiryhmään, joihin liittyi erilainen sydäntautiriski. Lisäksi itseorganisoituva kartta loi ultrasentrifugoinnilla eristetyille lipoproteiineille in silico -luokittelun, joten se tarjoaa uuden työkalun lipoproteiinitutkimukseen.
279

Physiopathologie de l'efflux de cholestérol du macrophage humain : relation avec le développement de l'athérosclérose et la mortalité chez des patients à haut risque cardiovasculaire / Physiopathology of human macrophage cholesterol efflux : relationship with the development of atherosclerosis in patients at high cardiovascular risk

Gall, Julie 05 April 2017 (has links)
La capacité des particules HDL à exercer des effets anti-athérogènes passe notamment par leur capacité à assurer le transport inverse du cholestérol (RCT). L'objectif principal de mon programme de recherche est l'étude de l'étape initiale du transport inverse du cholestérol que représente l'efflux de cholestérol du macrophage, dans le contexte des maladies métaboliques et du risque cardiovasculaire et de mortalité. J'ai étudié la relation entre l'efflux, et les conséquences sur le développement de l'athérosclérose dans un contexte métabolique particulier ; le syndrome métabolique (SM). J'ai démontré que les critères individuels du SM sont intimement liés à l'efflux et que ces deux notions sont associées de façon indépendante aux paramètres cliniques de l'athérosclérose. J'ai aussi évalué la pertinence de l'efflux de cholestérol comme biomarqueur de la mortalité. Cette étude identifie l'efflux comme prédicteur de la mortalité toutes causes confondues, indépendamment des taux de HDL-cholestérol et des facteurs de risques cardiovasculaires traditionnels, dans une population de patients traités par angioplastie coronaire primaire, suite à un infarctus du myocarde avec élévation du segment ST. Enfin, je me suis intéressée à à une situation métabolique particulière ; l'état postprandial. Mes travaux montrent que la réponse postprandiale hypertriglycéridémique physiologique observée chez des individus sans désordre métabolique ne s'accompagne pas d'altération majeure de l'efficacité du RCT ou de l'inflammation systémique. Mes travaux confirment le rôle déterminant de l'efflux dans la prévention du développement de l'athérosclérose et de la mortalité cardiovasculaire. / The contribution of high-density lipoprotein to cardiovascular benefit is closely linked to its anti-atherogenic role in the cellular cholesterol efflux. The main purpose of my project was to evaluate the efficiency of the first step of reverse cholesterol transport (RCT), which is the efflux capacity, on metabolic disorder context, on cardiovascular risk and on mortality. My research has focused on three independent and complementary parts. I have first evaluated the relationship between efflux and its consequences on atherosclerosis development in a metabolic syndrome (MetS) population. I have shown that individual criteria of MetS are closely related synergistically to cholesterol efflux capacity. In addition, established metabolic syndrome and cholesterol efflux capacity were independently associated with clinical features of atherosclerosis. In a second study I identified cholesterol efflux capacity as a predictor of all-cause mortality in consecutive ST-segment elevation myocardial infarction patients treated by primary angioplasty, independent of HDL-C, traditional cardiovascular risks or cardiac risk factors. Finally I have evaluated the consequences of postprandial hypertriglyceridemia on the functionality of key steps of RCT and associated anti-inflammatory components. My work has shown that the physiological postprandial hypertriglyceridemia response is not accompanied by a major alteration in the efficiency of RCT or systemic inflammation, on individual without metabolic syndrome. In conclusion, I have confirmed the crucial role of the first step of reverse cholesterol transport in preventing the development of atherosclerosis and cardiovascular mortality.
280

Einfluss von körperlichem Training bei chronischer Herzinsuffizienz auf die Transkription von proangiogenen microRNAs in Endothelzellen

Riedel, Saskia 19 November 2015 (has links)
Die chronische Herzinsuffizienz ist ein schwerwiegendes progredientes Krankheitsbild, das sich neben Dyspnoe und abnehmender Leistungsfähigkeit in einer nachgewiesenen Verschlechterung der HDL-Funktion manifestiert. In zahlreichen Studien, in denen der Einfluss von körperlichem Training auf die Progredienz der chronischen Herzinsuffizienz untersucht wurde, korrelierte dauerhaftes Ausdauertraining mit einer Verbesserung der eNOS-Aktivität und damit der HDLFunktion in Gefäßen. Ein Regulationsmechanismus von Endothelzellen besteht in der Expression von angiogenen microRNAs, die über negative Regulation die Proteinexpression beeinflussen. Ziel dieser Studie ist es nun, einen möglichen Zusammenhang zwischen der HDL-Funktionalität und der microRNA-Expression in Endothelzellen zu prüfen und damit die Funktionsänderung von HDL bei Herzinsuffizienten auf molekularer Ebene nachzuweisen. Zudem soll eine Beeinflussung der HDL-Funktion durch körperliches Training geprüft werden. Dafür wurde das HDL von gesunden und herzinsuffizienten Probanden (NYHAIII-Stadium) vor und nach einem vier- bzw. zwölfwöchigen Trainingsprogramm aus dem Plasma isoliert. Anschließend erfolgte mit dem gewonnenen HDL die 24-stündige Inkubation von HAEC-Kulturen. Nach Isolation der microRNAs aus dem gewonnenen Zelllysat konnte die Menge ausgewählter proangiogener miRs über RT-PCR quantifiziert werden. Die molekularbiologische Analyse der Proben zeigte eine, im Vergleich zu den Kontrollzellen, signifikant verringerte Menge an miR-21, -126 und -222 in den, mit HDLNYHAIII-inkubierten, Endothelzellen. Die miR-Expression der Endothelzellen zeigte nach dem Trainingsprogramm eine Annäherung an das Expressionsniveau der Kontrollen. Aus der dargelegten Studie wird so ersichtlich, dass das HDL von Herzinsuffizienten die Expression von proangiogenen microRNAs in Endothelzellen hemmt, was scheinbar in Korrelation mit der Ausbildung von endothelialen Dysfunktionen bei Herzinsuffizienz steht. Zudem konnte gezeigt werden, dass körperliches Training mit einer verbesserten Endothelfunktion über die Erhöhung der miR-Expression in Endothelzellen einhergeht.

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