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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.
21

Role Of Transmembrane 141 in Cholesterol Metabolism

Al-Khfajy, Wrood Salim Dawood 19 November 2014 (has links)
No description available.
22

The Interplay Between Apolipoproteins and ATP-Binding Cassette Transporter A1

Smith, Loren E. 06 December 2010 (has links)
No description available.
23

Die Adsorption von Lipoproteinen an der Oberfläche fibrogener und inerter Mineralstäube

Bogatu, Bettina Ulrike 14 June 2004 (has links)
Sieben fibrogene und fünf nicht fibrogene (inerte) Mineralstäube wurden auf ihr Adsorptionsvermögen gegenüber Lipoproteinen untersucht. Die Adsorption erfolgte aus menschlichem Serum bzw. bovinem Lipoproteinkonzentrat. Die spezifischen Oberflächen der Stäube wurden mit Hilfe einer neuen Methode ermittelt, die auf der Adsorption von Nonadecansäure beruht. Sie vernachlässigt Oberflächenporen mit Öffnungsdurchmessern / Seven fibrogenic and five nonfibogenic (inert) mineral dusts were examined for their adsorption capacity for lipoproteins. Lipoproteins came from human serum and bovine lipoprotein- concentrate. The specific surface areas of the dusts were determined with the help of a new method, which is based on the adsorption of nonadecanoic acid. It neglects surface pores with opening diameters less than 2,5nm. The most important result is that fibrogenic dusts adsorb significantly more high density lipoproteins (HDL), than the inert dusts. The adsorption of HDL on quartz can be reduced up to 96% by addition of Polyvinylpyridine-N-oxide (PVPNO), an inhibitor of quartz- induced fibrosis. The HDL- adsorption might play a role during the developing process of mineral-dust-induced fibrosis.
24

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

Riedel, Saskia 01 February 2017 (has links) (PDF)
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.
25

Structural studies of HDL and applications of EM on membrane proteins

Zhu, Lin January 2017 (has links)
A large number of proteins interact with biological membranes, either integrated in the membrane (PepTSo2), embedded on a membrane surface (5-lipoxygenase) or encircling a cutout of lipid bilayer (apolipoprotein1 (apoA-I). They function as transporters, receptors or biocatalysts in cellular processes like inflammation or cholesterol transport which are touched upon here. Malfunction of specific membrane proteins are the cause for several diseases or disorders. Knowledge of protein structure supports understanding of its mechanism of function. Here, transmission electron microscopy (TEM) was used for structure determination. To obtain structure information to high resolution for membrane proteins, normally surrounded by lipids, demands specific methods and materials for stabilization. Stabilized in detergent the structure of the bacterial transporter PepTSo2 was shown to form a tetramer even bound to substrate. However, with a protein based stabilizer, Salipro, the structure of PepTSo2 could be determined to high resolution. High density lipoprotein (HDL) in blood plasma, involved in the removal of cholesterol from peripheral tissues, have a central role in cardiovascular function, metabolic syndrome and diabetes. The HDL-particle is composed of two copies of ApoA1 and around hundred lipid molecules. From TEM data, for the first time the clearly discoidal shape could be shown by 3-dimendional reconstructions. These were used for modelling the ApoA1 protein dimer by a "biased fitting" procedure. The results indicate how ApoA1 folds around a lipid bilayer in a disc-shaped structure. Modified HDL called nanodiscs were here used to show the Ca2+ dependent binding of 5-lipoxygenase on the nanodisc bilayer and thereby increased production of the inflammatory mediator leukotrieneA4. Dimerization of 5-lipoxygenase inactivates these functions. / <p>QC 20170323</p>
26

Studies on Lipoprotein Specificity of Human Plasma Lecithin Cholesterol Acyltransferase

Jahani, Mehrnoosh 05 1900 (has links)
Huian plasma high-density lipoprotein (HDL) were isolated by a procedure employing polyanion precipitation and column chromatography. Lipid and protein composition of the HDL isolated by this method was found to be similar to another HDL preparation isolated by ultracentrifugation. However, minor differences were noted, including a higher phospholipid and apoproteinE content and lower triglyceride content of the HDL isolated by column chromatography. Four subfraction of HDL were obtained following chromatography on an anion exchange column. The subfraction four had the highest esterified to free cholesterol ratio, the second highest phospholipid to unesterified cholesterol, and the lowest molecular weight. In addition it was consistently coincided with lecithin: cholesterol acyltransferase (LCAT) activity and found to be the best substrate for the enzyme.
27

Impacto da incorporação de ômega 3 na funcionalidade da lipoproteína de alta densidade: ensaio clínico aleatorizado, paralelo e controlado / Impact of omega 3 incorporation on the functionality of high-density lipoprotein: randomized, parallel and controlled clinical trial

Cartolano, Flavia de Conti 26 September 2018 (has links)
INTRODUÇÃO: Apesar de classicamente a lipoproteína de alta densidade (HDL) ser descrita como um fator de risco independente para as doenças cardiovasculares (DCV), devido ao seu papel no transporte reverso de colesterol (TRC), atualmente sabe-se que esta partícula exerce múltiplos mecanismos biológicos que podem contribuir para esta cardioproteção, com estudos indo além do conteúdo de colesterol associada à HDL (HDL-C). OBJETIVO: Avaliar o impacto da suplementação de ?-3 no perfil de ácidos graxos, tamanho e capacidade antioxidante da HDL. MÉTODOS: Estudo clínico, aleatorizado, controlado, duplo cego e paralelo, onde foram incluídos 147 indivíduos adultos, com fatores de risco cardiovascular, que foram alocados no grupo ?-3 (n=77 - 3,0 g/dia contendo 1,8 g de EPA+DHA) ou no grupo ?-6 (n=70 - 3,0 g/dia de óleo de girassol contendo 1,95 g de ácido linoleico). No início (T0) e após 8 semanas (T8) amostras de sangue foram coletadas e, a partir do plasma ou soro, foram analisados o perfil lipídico (CT, HDL-C, LDL-C, TG), as apolipoproteínas AI, CII e CIII, as subfrações da HDL (Lipoprint®), a atividade da paraoxonase (PON1) e da proteína transportadora de éster de colesterol (CETP), a capacidade antioxidante da HDL (método experimental) e o perfil de ácidos graxos e conteúdo de AGNEs da HDL. Os resultados do efeito do tempo, da intervenção e das interações entre os parâmetros monitorados e os desfechos foram realizados com o auxílio do programa SPSS® versão 20.0. O valor de significância considerado foi de p<0,05. RESULTADOS: Os grupos ?-3 e ?-6 eram semelhantes entre si em relação a idade, sexo, tabagismo e uso de medicamentos, ambos apresentando alta prevalência de hipertensão e dislipidemia. Nos dois grupos, houve redução em todos os marcadores lipídicos, exceto a concentração de HDL-C, que aumentou. Observou-se o efeito do tempo no conteúdo de HDLAGNEs (?=-16,2%), no percentual de HDLGRANDE (?=20,1%) e de HDLPEQUENA (?=-5,0%). O aumento de EPA na HDL se associou à menor chance de ter elevação da atividade da PON1 (OR=0,446; IC=0,200-0,994), da concentração de HDLAGNEs (OR=0,275; IC=0,113-0,660) e do percentual de HDLPEQUENA (OR=0,337; IC=0,146-0,782). Observou-se ainda que o EPA se associou a, aproximadamente, 3,5 mais chances de aumento no percentual da HDLGRANDE (OR=3,522; IC=1,652-7,507). Quanto ao aumento de DHA na HDL, este esteve associado de maneira significativa à diminuição da concentração de Apo AI (OR=0,351; IC=0,150-0,821), além da atividade da PON1 (OR=0,226; IC=0,110-0,639) e da concentração de HDLAGNEs (OR=0,275; IC=0,113-0,668). Resultados similares aos obtidos com o EPA foram observados para o DHA e o tamanho da HDL. Não foi constatado efeito da incorporação de EPA e DHA na resistência à oxidação. CONCLUSÃO: A intervenção com ?-3 promoveu mudanças na composição da partícula de HDL, aumentando o percentual das subfrações maiores, sem, contudo, modificar sua capacidade antioxidante. / BACKGROUND: Although high-density lipoprotein (HDL) is classically described as an independent risk factor for cardiovascular disease (CVD), because of its role in reverse cholesterol transport (RCT), currently, it is known that this particle exerts multiple biological mechanisms that may contribute to this cardioprotection, with studies going beyond HDL cholesterol content (HDL-C). OBJECTIVE: To evaluate the impact of ?-3 supplementation on the fatty acid profile, size and antioxidant capacity of HDL. METHODS: A randomized, controlled, double-blind, parallel clinical study involving 147 adult subjects with cardiovascular risk factors, who were allocated into the ?-3 group (n=77 -3.0 g/day containing 1.8 g EPA + DHA) or the ?-6 group (n=70 -3.0 g/day of sunflower oil containing 1.95 g of linoleic acid). In the beginning (T0) and after 8 weeks (T8) blood samples were collected and, from plasma or serum, were analyzed lipid profile (TC, HDL-C, LDL-C, TG), apolipoproteins AI, CII and CIII, HDL subfractions (Lipoprint®), paraoxonase (PON1) and cholesterol ester carrier protein (CETP) activities, antioxidant capacity of HDL (experimental method), the fatty acid profile and NEFAs content HDL. Results of the effect of time, intervention and interactions between monitored parameters and outcomes were performed with the aid of SPSS® software version 20.0. The significance level considered was p<0.05. RESULTS: The ?-3 and ?-6 groups were similar in relation to age, sex, smoking and medication use, both presenting high prevalence of hypertension and dyslipidemia. In both groups, there was a reduction in all lipid markers except HDL-C concentration, which increased. The effect of time on HDLNEFAs content (?=-16.2%), and on the percentage of HDLLARGE (?=20.1%) and HDLSMALL (?=-5.0%) were observed. Increasing EPA in HDL was associated with a lower chance of enhance PON1 activity (OR=0.446, CI=0.200-0.994), HDLNEFAs concentration (OR=0.275, CI=0.113-0.660), and HDLSMALL (OR=0.337, CI=0.146- 0.782). It was also observed that EPA was associated with approximately 3.5 more chances of raising the percentage of HDLLARGE (OR=3.522, CI=1.652-7.507). Increasing DHA in HDL was significantly associated with a decrease in Apo AI concentration (OR=0.351, CI=0.150- 0.821), and also PON1 activity (OR=0.226, CI=0.110-0.639) and concentration of HDLNEFAs (OR=0.275, CI=0.113-0.668). Similar results obtained with EPA were observed for DHA and HDL size. No effect of the incorporation of EPA and DHA on oxidation resistance was observed. CONCLUSION: The ?-3 intervention promoted changes in the composition of the HDL particle, increasing the percentage of the larger subfractions, without, however, modifying its antioxidant capacity.
28

High‐density lipoprotein mutant eye drops for the treatment of posterior eye diseases / 高比重リポタンパク変異体を利用した後眼部疾患に対する点眼治療の開発

Suda, Kenji 23 January 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20810号 / 医博第4310号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 清水 章, 教授 萩原 正敏, 教授 松原 和夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
29

Development of Biocompatible Polymer Monoliths for the Analysis of Proteins and Peptides

Li, Yun 12 August 2009 (has links) (PDF)
Biocompatibility is an important issue for the development of chromatographic stationary phases for the analysis of biomolecules (including proteins and peptides). A biocompatible stationary phase material is a material that resists nonspecific adsorption of biomolecules and does not interact with them in a way that would alter or destroy their structures or biochemical functions. The monolithic column format is a good alternative to typical spherical particle packed columns for capillary liquid chromatography of biomacromolecules. Several novel anion-exchange polymer monoliths for the analysis of proteins were synthesized for improved biocompatibility. Two novel polymeric monoliths were prepared in a single step by a simple photoinitiated copolymerization of 2-(diethylamino)ethyl methacrylate and polyethylene glycol diacrylate (PEGDA), or copolymerization of 2-(acryloyloxy)ethyl trimethylammonium chloride (AETAC) and PEGDA, in the presence of selected porogens. The resulting monoliths contained functionalities of diethylaminoethyl (DEAE) as a weak anion exchanger and quaternary amine as a strong anion exchanger, respectively. An alternative weak anion exchange monolith with DEAE functionalities was also synthesized by chemical modification after photoinitiated copolymerization of glycidyl methacrylate (GMA) and PEGDA. The dynamic binding capacities of the three monoliths were comparable or superior to values that have been reported for various other monoliths. Chromatographic performances were also similar to those provided by a modified poly(GMA-co-ethylene glycol dimethacrylate) monolith. Separations of standard proteins were achieved under gradient elution conditions using these monolithic columns. This work represents a successful attempt to prepare functionalized monoliths via direct copolymerization of monomers with desired functionalities. Compared to earlier publications, laborious surface modifications were avoided and the PEGDA crosslinker improved the biocompatibility of the monolithic backbone. Protein separations by capillary size exclusion chromatography (SEC) require a monolith that is biocompatible, has sufficient pore volume, has the appropriate pore size distribution, and is rigid. Most polymer monoliths have not possessed a biomodal pore-size distribution, i.e., especially with one distribution in the macropore region and the other in the mesopore region. Furthermore, non-specific adsorption of proteins in these stationary phases has persisted as a major unresolved problem. To overcome these difficulties, a porous poly[polyethylene glycol methyl ether acrylate (PEGMEA)-co-PEGDA] monolith which can resist adsorption of both acidic and basic proteins when using an aqueous buffer without any organic solvent additives was developed. Based on this biocompatible monolith, surfactants were introduced as porogens with the hope of significantly increasing the mesopore volume within the polymer. Two types of surfactants were studied, including poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) or PPO-PEO-PPO and Brij. Pore size distributions were examined using a well-defined molecular weight range series of proteins and peptides by inverse size exclusion chromatography, which indicated relatively large volume percentages of mesopores and micropores. The two new monoliths demonstrated different SEC behaviors, low nonspecific adsorption of proteins, and high mechanical rigidity. High density lipoprotein (HDL) is a heterogeneous class of lipoprotein particles with subspecies that differ in apolipoprotein and lipid composition, size, density, and charge. In this work, I developed a new capillary SEC method for size separation of native HDL particles from plasma using a capillary packed with BioSep-SEC-4000 particles, Three major sizes of HDL particles were separated. Additionally, capillary SEC and capillary strong anion-exchange chromatography of non-delipidated HDL were accomplished using poly(PEGMEA-co-PEGDA) and poly(AETAC-co-PEGDA) monoliths. These new LC methods using packed and monolithic stationary phases provided rapid separation of HDLs and excellent reproducibility.
30

Relationship Between Lipid Profiles and Hypertension: A Cross-Sectional Study of 62,957 Chinese Adult Males

Chen, Siwei, Cheng, Wenke 10 October 2023 (has links)
Background Patterns of dyslipidemia and incidence of hypertension have been rarely reported in Asian populations with inconsistent findings. To accumulate further evidence in Asian populations, the study aimed to investigate the relationship between lipid profiles and hypertension in Chinese adult males. Methods We conducted a cross-sectional study based on the data from the DATADRYAD database. The overall population was divided into hypertensive and non-hypertensive groups based on baseline blood pressure levels. For continuous variables, Mann-Whitney test was performed between two groups, while Kruskal-Wallis and Dunn tests were used among multiple groups. The chi-square test was carried out for dichotomous variables. Spearman's correlation coefficient was employed to assess the association between systolic blood pressure (SBP), diastolic blood pressure (DBP) and lipid profiles, whereas the relationship between lipid profiles and the incidence of hypertension was evaluated using multivariate logistic regression. The Bayesian network (BN) model was adopted to investigate the relationship between clinical characteristics and hypertension, and the importance of related predictor to the incidence of hypertension was obtained to make conditional probability analysis. Results Finally, totally 62,957 participants were included in this study. In the lipid profiles, total cholesterol (TC), low-density cholesterol (LDL-c), and non- high-density lipoprotein cholesterol (non-HDL-c) were higher in the hypertensive population (p <0.001). In the fully multivariate model, for every 1 mg/dl increase in TC, LDL-c and non-HDL, the risk of hypertension increased by 0.2% [1.002 (1.001–1.003)], 0.1% [1.001 (1.000–1.002)], and 0.1% [1.001 (1.000–1.002)]. Meanwhile, HDL-c became positively associated with the incidence of hypertension (p for trend < 0.001) after adjusting for the body mass index (BMI), and 1 mg/dl increment in HDL-c increased the risk of hypertension by 0.2% [1.002 (1.000–1.002)] after fully adjusting for multiple variables. Furthermore, the BN showed that the importance of age, BMI, fasting plasma glucose (FPG), and TC to the effect of hypertension is 43.3, 27.2, 11.8, and 5.1%, respectively. Conclusion Elevated TC, LDL-c, and non-HDL-c were related to incidence of hypertension in Chinese adult males, whereas triglycerides (TG) was not significantly associated. The relationship between HDL-c and hypertension incidence shifted from no association to a positive correlation after adjusting for the BMI. Moreover, the BN model displayed that age, the BMI, FPG, and TC were strongly associated with hypertension incidence.

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