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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.
121

Weekly One-Day Water-Only Fasting Interventional Trial for Low-Density Lipoprotein Cholesterol Reduction (WONDERFUL)

Bartholomew, Ciera Lynn 30 March 2021 (has links)
Purpose: Fasting has been promoted as a method of preventing disease and aging for thousands of years. With heart disease being a leading cause of death in the U.S., researchers have explored the effects of fasting on variables that influence cardiovascular disease (CVD), like LDL cholesterol. Therefore, the purpose of this study was to assess the effects of weekly water-only fasting on LDL cholesterol (LDL-C) in men and women with metabolic risk factors for CVD. Methods: This study was a randomized control trial in adult men and women. Participants were randomized to fasting (treatment) or normal diet (control). The fasting protocol consisted of four weeks of two 24-hour water-only fasts, followed by 22 weeks of once-weekly water-only 24-hour fasts. Measurements such as height, weight, waist circumference and LDL-C were assessed at baseline, 4 weeks, 13 weeks, and 26 weeks. Results: Intermittent fasting (n = 50) and control (n = 53) participants were 49.3 ± 12.0 and 47.0 ± 9.8 years, respectively, predominantly females (66.0% and 67.9%), overweight (103 ± 24 and 100 ± 21 kg), and with mild LDL-C elevation (124 ± 19 and 128 ± 20 mg/dL). Change in weight was −1.70 ± 4.69 (kg) in the fasting group and 0.20 ± 3.45 (kg) in the control group and not different between conditions (p = 0.06). There was no condition-by-period interaction for LDL-C (p = 0.06). Similarly, the change in LDL-C from baseline to follow-up was not different between conditions (t = −0.538, p = 0.59; Cohens D = 0.12) Conclusions: A once-per-week intermittent fasting regimen did not reduce weight or LDL-C. Further research of such fasting regimens is needed to evaluate their potential impact on cardiometabolic health.
122

Human Monocyte Scavenger Receptors Are Pattern Recognition Receptors for (1→3)-β-D-Glucans

Rice, Peter J., Kelley, Jim L., Kogan, Grigorij, Ensley, Harry E., Kalbfleisch, John H., William Browder, I., Williams, David L. 01 July 2002 (has links)
Glucans are cell wall constituents of fungi and bacteria that bind to pattern recognition receptors and modulate innate immunity, in part, by macrophage activation. We used surface plasmon resonance to examine the binding of glucans, differing in fine structure and charge density, to scavenger receptors on membranes isolated from human monocyte U937 cells. Experiments were performed at 25°C using a biosensor surface with immobilized acetylated low density lipoprotein (AcLDL). Inhibition of the binding by polyinosinic acid, but not polycytidylic acid, confirmed the interaction of scavenger receptors. Competition studies showed that there are at least two AcLDL binding sites on human U937 cells. Glucan phosphate interacts with all sites, and the CM-glucans and laminarin interact with a subset of sites. Polymer charge has a dramatic effect on the affinity of glucans with macrophage scavenger receptors. However, it is also clear that human monocyte scavenger receptors recognize the basic glucan structure independent of charge.
123

Effects of a Comprehensive Wellness Program on Serum Lipid Concentration Among the Residents

Williams, Kimberly A. 16 December 2010 (has links)
No description available.
124

The effect of simvastatin and pitavastatin on insulin secretion from clonal pancreatic ß-cells (INS-1)

Abdul-Akbar, Princess Maryam 13 February 2024 (has links)
OBJECTIVE: The 10th leading cause of death in the United States is heart disease. Most of the deaths by heart disease has a correlation with an occlusion of the coronary arteries. While diabetes mellitus is currently the 7th leading cause of death, which is a chronic condition that affects more than 37 million people in America. The global epidemic of obesity largely explains the dramatic increase in the incidence and prevalence of type 2 diabetes (T2D) over the past 25 years. Statins are well known drugs to decrease LDL for individuals who suffer from hypercholesterinemia; however, there is also an increased risk of developing diabetes mellitus. An estimation of 10-20 per 10,000 patients per year demonstrated an excess risk of T2D with the long-term use of statin. Here we examine the effects of simvastatin and pitavastatin on pancreatic ß-cell function to determine whether altered insulin secretion may contribute to an increased risk of T2D. METHODS: The experiments were performed using clonal pancreatic ß-cells (INS-1). The cells were grown in 4 mM glucose in RPMI media. Cells were grown for three days before adding the different types of statins: simvastatin and pitavastatin for one day. Then the cells were used to perform the glucose-induced insulin secretion (GSIS) experiment. Insulin secretion and insulin content were assay using a fluorescence-based immunoassay. The study was calculated using Microsoft Excel. Standard variance and standard error were used to assess the difference sets of data. RESULTS: INS-1 cells responded to acute glucose stimulation after chronic culture in both low (4 mM) and high (11 mM) glucose. Secretion from cells cultured at 4 mM glucose was higher than cells cultured at 11 mM glucose at all glucose concentrations tested, characteristic of the effects of glucolipotoxicity (GLT). Insulin content in cells cultured at high glucose was decreased 8.6-fold compared to cells cultured at the more physiological low glucose condition. When normalized to basal secretion cells cultured at high glucose exhibited basal hypersecretion and increased GSIS compared to those in low glucose. Simvastatin (100 nM, 24 hrs) increased basal insulin secretion to a greater extent than Pitavastatin. The effects of pitavastatin on basal insulin secretion were less consistent than seen with simvastatin. Simvastatin was also shown to inhibit GSIS from cells cultured at 4 mM glucose, while pitavastatin increased GSIS. CONCLUSION: Both pitavastatin and simvastatin alter insulin secretion from pancreatic ß-cells. The effect of simvastatin to both increase basal and decrease GSIS, characteristic of GLT suggests pitavastatin may be the statin of choice to reduce the risk of statin-induced T2D.
125

Interaction between CD36 and Oxidized LDL Modulates Macrophage Cytoskeletal Functions: A Mechanism of Macrophage Trapping

Park, Young Mi 06 July 2010 (has links)
No description available.
126

A novel pathway for VLDL assembly in the mouse liver / Ein neuer Stoffwechselweg zur Synthese von VLDL in der Mausleber

Mleczko, Anna 02 November 2006 (has links)
No description available.
127

Verifiering av P-LDL-kolesterol på Beckman Coulter AU680 / Verification of P-LDL-cholesterol on Beckman Coulter AU680

Oliveira Ivarsson, Martin January 2019 (has links)
Kolesterol transporteras i blodet med hjälp av lipoproteinpartiklar. Höga nivåer av low-density lipoprotein (LDL)-kolesterol i blodet är en riskfaktor för kardiovaskulär sjukdom. Koncentrationen av LDL-kolesterol kan beräknas med hjälp av Friedewalds formel men det finns även metoder där LDL-kolesterol kan analyseras direkt. Syftet med arbetet var att verifiera metoden direkt LDL-kolesterol på analysinstrumentet Beckman Coulter AU680. Metodens inomserie- och totalimprecision analyserades. Två korrelationsstudier utfördes mellan direkt LDL-kolesterol och beräknat LDL-kolesterol, en med 43 patientprover med triglycerider < 4,5 mmol/L och en med 11 patientprover med triglycerider > 4,5 mmol/L. Friedewalds formel ska egentligen inte användas vid triglycerider > 4,5 mmol/L, men i detta fall användes formeln ändå för att utvärdera eventuella skillnader mellan metodernas resultat vid höga triglyceridkoncentrationer. Vid analys av metodens inomserieimprecision blev variationskoefficienten (CV) omkring 0,5 % vid analys av både den låga kontrollen (A1) och den höga kontrollen (A2). CV för totalimprecisionen blev 1,21 % vid analys av A1 och 1,11 % vid analys av A2. Korrelationsstudierna visade ett linjärt samband mellan metoderna men den direkta metoden gav något högre resultat vid lägre koncentrationer och något lägre resultat vid högre koncentrationer jämfört med beräknat LDL-kolesterol. Vid triglycerider > 4,5 mmol/L gav den direkta metoden betydligt högre resultat än beräknat LDL-kolesterol. Slutsatsen blev att metoden hade god precision. Överensstämmelsen mellan metodernas resultat var relativt bra för proverna med triglycerider < 4,5 mmol/L. Vid triglycerider > 4,5 mmol/L var differensen mellan metoderna stor, troligtvis på grund av falskt för låga resultat från beräknat LDL-kolesterol. / Cholesterol is transported in the blood by lipoproteins. High levels of low-density lipoprotein (LDL)-cholesterol in the blood is a risk factor for cardiovascular disease. The concentration of LDL-cholesterol can be calculated using the Friedewald formula but there are also methods that measure LDL-cholesterol directly. The aim of this study was to verify the method P-LDL-cholesterol on a Beckman Coulter AU680 analyzer. Within-run imprecision and total imprecision were analyzed. The correlation between direct LDL-cholesterol and calculated LDL-cholesterol was examined using 43 patient samples with triglyceride levels < 4,5 mmol/L and 11 patient samples with triglyceride levels > 4,5 mmol/L. The Friedewald formula is not supposed to be used on triglyceride levels > 4,5 mmol/L, but in this case the formula was used anyway to evaluate differences between the methods at high triglyceride concentrations. The coefficient of variation (CV) for the within-run imprecision was about 0,5 %, both for the low control (A1) and the high control (A2). Total imprecision had a CV of 1,21 % for A1 and 1,11 % for A2. There was a linear relationship between the methods, but the direct method gave slightly higher results at low concentrations and slightly lower results at high concentrations compared to calculated LDL-cholesterol. At triglyceride levels > 4,5 mmol/L the results from the direct method was considerably higher than calculated LDL-cholesterol. The conclusion is that the precision of the method was good. The correlation between the results from direct LDL-cholesterol and calculated LDL-cholesterol was relatively high for samples with triglyceride levels < 4,5 mmol/L. At triglyceride levels > 4,5 mmol/L there was a big difference between the methods, probably because of falsely low results from calculated LDL-cholesterol.
128

Atividade antioxidante do chá mate (Ilex paraguariensis) / Antioxidant activity of tea mate (Ilex paraguariensis)

Matsumoto, Ruth Lobato Teixeira 25 June 2008 (has links)
INTRODUÇÃO: A erva-mate (Ilex paraguarienis), uma planta nativa e consumida em grande parte da América do Sul, apresenta diversos compostos bioativos que já demonstraram importante atividade antioxidante in vitro e in vivo. O chá mate é um produto desta planta cujas propriedades antioxidantes ainda não foram avaliadas em ensaios com humanos. OBJETIVO: Este projeto visa avaliar o potencial antioxidante do chá mate in vivo e ex vivo sobre o plasma e LDL de humanos após a ingestão de chá-mate. MÉTODOS: Indivíduos em jejum (n=20) tiveram seu sangue coletado em três momentos: antes, após uma hora e depois de 1 semana (7 dias) da ingestão diária de chá-mate. O plasma e a LDL obtidos nos três momentos foram submetidos à oxidação por três mecanismos diferentes [Cobre (Cu+2), lipoxigenase e peroxinitrito (SIN-1)] e em seguida foram medidos os produtos de peroxidação lipídica formados: a concentração de TBARs (substâncias reativas ao ácido tiobarbitúrico) e a formação de dienos conjugados empregando-se métodos espectrofotométricos. Também foram determinados o perfil antioxidante total do plasma (TAS), avaliação da lipoperoxidação plasmática basal (TBARs), avaliação da fragmentação da Apolipoproteína B após oxidação da LDL, por eletroforese em gel com SDS-PAGE e os níveis de expressão, por meio de análise de PCR real time, de alguns genes relacionados à produção de enzimas antioxidantes. Teste t de Student pareado foi utilizado para verificar se houve diferença estatisticamente significante entre os resultados das diversas análises antes e após o consumo do chá. RESULTADOS: Os resultados obtidos pela maioria dos ensaios realizados demonstraram que o consumo de chá mate aumentou a resistência à oxidação, a capacidade antioxidante plasmática e a expressão de genes relacionados à produção de enzimas antioxidantes. CONCLUSÃO: Esses resultados sugerem que o consumo de chá mate por período curto pode atuar como antioxidante por múltiplos mecanismos e portanto pode contribuir para diminuição do risco de desenvolvimento de doenças crônicas relacionadas a processos oxidativo. / Yerba Mate (Ilex paraguariensis) is a native and widely consumed South American plant. It contains high concentrations of bioactive compounds that respond for its high antioxidant activity in vitro and in vivo. This activity has not been demonstrated yet in humans for the mate tea, a product derived from Yerba Mate. OBJECTIVE: The aim of this study was to evaluate the antioxidant activity of maté tea in vivo and ex vivo on plasma and LDL human after ingestion of mate tea infusion. METHODS: Fasting peripheral venous blood samples of twenty healthy women (n=20) were taken in three different times: before drinking the tea, one hour later and after one week of daily consumption (7 days) of mate tea. The plasma and isolated LDL were oxidated with 3 different systems [copper (CuSO4), lipoxygenase and peroxynitrite (SIN-1)]. Next, the peroxidation products evaluated were: concentration of malonaldeyde (TBA) and conjugated dienes (lag time), using spectrophotometric methods. We also measured the plasma total antioxidant status (TAS), serum levels of malondialdehyde (MDA) as thiobarbituric substances (TBARS), fragmentation of apo B using SDS-PAGE and the level of antioxidant enzyme gene expression by PCR real time. Paired t student test was used to analyze the results before and after ingestion of mate tea. RESULTS: The results obtained by most of the tests showed that mate tea ingestion increased the plasma and LDL resistance by ex vivo oxidation, the plasma antioxidant capacity and the level of antioxidant enzyme gene expression. CONCLUSION: This study suggests that regular consumption of mate tea can act as an antioxidant by multiple mechanisms and thus may contribute decrease the risk of developing chronic diseases related to oxidative processes.
129

Anticorpos contra lipoproteína de baixa densidade oxidada (oxLDL) e peptídeo da apolipoproteína B, aposB, (apoBD) como possível marcador no acompanhamento da eficácia do tratamento com Rosuvastatina em pacientes hipercolesterolêmicos. / Auto-antibodies against oxidized low density lipoprotein (oxLDL) and apoB peptide of apolipoprotein B (apoBD) as possible marker for monitoring effectiveness of Rosuvasatin tratament on hypercholesterolemic patients.

Trentin, Rafael Cardoso 05 September 2013 (has links)
Nesta dissertação, estudamos o efeito da Rosuvastatina (Ros) sob pacientes hipercolesterolêmicos. Dentro de 180 dias de estudo prospectivo, avaliamos a eficácia da utilização de anticorpos contra a LDL oxidada ou contra sequência peptídica da apolipoproteína B (apoBD) como marcadores no acompanhamento de resposta à droga. Acompanhamos 76 pacientes (Ros.,n=40/cont.,n=36) através das seguintes variáveis: perfil lipídico, TBARS, anticorpos IgG e IgM anti-oxLDL e IgG anti-apoBD. A partir dos resultados obtidos, concluímos que: não houve alterações consideradas significativas dentro do perfil lipídico; o tratamento controle reduziu significativamente TBARS; os anticorpos IgM anti-oxLDL e IgG anti-apoBD foram sensíveis como marcadores e houve redução significativa destes apenas no tratamento com Rosuvastatina; os níveis de anticorpos IgM e IgG anti-oxLDL não são correlacionados; existe correlação direta entre anticorpos IgG anti-oxLDL e anti-apoBD; os níveis de LDL se correlacionam inversamente aos níveis de IgG anti-oxLDL e IgG anti-apoBD. / In this dissertation, we studied the effect of rosuvastatin (Ros) in hypercholesterolemic patients. During 180 days, we evaluated t if antibodies against oxidized LDL or against a peptide from apolipoprotein B (apoBD) would work as markers to monitor a response to the drug. We enrolled 76 patients (Ros.,n = 40/cont.,n = 36 and used the following variables: lipid profile, TBARS, IgG and IgM anti-oxLDL and IgG anti-apoBD., We conclude that there were no significant changes seen in the lipid profile, the control treatment significantly reduced TBARS ,IgM anti-oxLDL and IgG anti-apoBD were sensitive markers and decreased significantly only in the treatment in Ros group; levels of IgM and IgG anti-oxLDL are not correlated; there is a direct correlation between IgG anti-oxLDL and anti-apoBD; LDL levels correlate inversely with levels of IgG anti-oxLDL and IgG anti-apoBD.
130

Cinética plasmática do colesterol livre e do colesterol esterificado e transferência in vitro de lípides para a HDL, utilizando uma nanoemulsão lipídica artificial, em indivíduos com intolerância à glicose / Plasma kinetics of free and esterified cholesterol and in vitro lipid transfer to HDL, using an artificial lipidic nanoemulsion, in subjects with glucose intolerance

Bertato, Marina da Paz 26 March 2010 (has links)
O indivíduo com diabetes mellitus tipo 2 apresenta um risco de 2 a 4 vezes maior de desenvolver doença cardiovascular (DCV) quando comparado ao não-diabético, sendo que este aumento do risco para o desenvolvimento da DCV também é observado quando na intolerância à glicose (IG) que ocorre em fases mais precoces da história natural do diabetes. Atribui-se ser a presença da síndrome metabólica (SM), que ocorre na maioria dos pacientes com DM2 e IG, um fator importante para o desenvolvimento da DCV nestes indivíduos. Dos componentes da SM, inúmeros estudos destacam a dislipidemia como um dos principais fatores para este risco. A dislipidemia comumente encontrada na IG é caracterizada por hipertrigliceridemia, baixo HDL-C e presença de LDL pequena e densa. Entretanto, como a elevação dos níveis séricos do LDL-C associada ao surgimento de aterosclerose prematura em indivíduos não diabéticos na maioria das vezes não é observada em pacientes com IG, questiona-se se outras alterações do metabolismo lipídico, tais como alterações da cinética do colesterol ou a transferência de lípides das lipoproteínas para a HDL, poderiam estar relacionadas ao maior risco cardiovascular nestes pacientes. Estudo prévio, utilizando uma nanoemulsão lipídica artificial de LDL, verificou uma remoção mais rápida do colesterol na forma livre em pacientes normolipidêmicos com doença arterial coronária (DAC) quando comparada com controles. No presente estudo, utilizou-se a nanoemulsão lipídica artificial para avaliar se esses dois processos envolvidos no metabolismo da LDL e da HDL estão alterados em pacientes com intolerância à glicose que os predispõem à DAC, relacionando estes resultados com fatores de risco cardiovasculares, tais como a resistência à insulina, a obesidade e a dislipidemia. Para tanto, foram estudados 14 pacientes com IG e 15 controles, sem manifestação clínica de DCV, que não utilizam antidiabéticos orais e hipolipemiantes, comparados com controles pareados para idade, sexo, raça, IMC, tabagismo, consumo de álcool, prática de atividade física e doenças associadas. Para o estudo cinético, a nanoemulsão marcada foi injetada endovenosamente e amostras de sangue coletadas ao longo de 24h para a determinação da radioatividade, das curvas de decaimento plasmático e da taxa fracional de remoção (TFR) dos lípides marcados a partir de um modelo de análise compartimental. Foi medida a taxa de esterificação do 3Hcolesterol livre da nanoemulsão no plasma e avaliada a transferência in vitro de lípides da nanoemulsão para a fração HDL. A resistência à insulina foi estimada pelo modelo matemático de homeostase glicêmica (HOMA) e a adiposidade abdominal por tomografia computadorizada de abdômen. A concentração plasmática de colesterol total, LDL-C, HDL-C, triglicérides e de apolipoproteínas não diferiu entre os grupos. O perfil antropométrico relacionado ao peso, IMC e circunferência abdominal foi semelhante entre os grupos. O grupo IG apresentou maior concentração de insulina de jejum (p=0,01), menor sensibilidade à insulina (p<0,01) e maior índice de resistência à insulina (p<0,01). A TFR 14C-EC foi similar nos dois grupos, porém a TFR 3H-CL foi mais rápida no grupo IG comparado com controle (p=0,04). A porcentagem de esterificação do 3H-colesterol da nanoemulsão bem como a transferência de lípides da nanoemulsão para a fração HDL foram semelhantes entre os grupos. A remoção mais rápida do 3H-colesterol livre mostra que ocorreu uma dissociação das partículas de colesterol da nanoemulsão lipídica nos pacientes com intolerância à glicose. Essa dissociação do colesterol pode refletir alterações no metabolismo intravascular da lipoproteína LDL, as quais podem favorecer a aterogênese nesses pacientes / Individuals with diabetes mellitus type 2 are 2 to 4 times more susceptible to cardiovascular disease (CVD) than non-diabetic individuals. This increased risk is also observed for glucose intolerance (GI) which appears in the initial stages of diabetes. The presence of the metabolic syndrome (MS), present in most DM2 and GI patients, is also an important factor contributing to the development of CVD in these individuals. Various MS component studies emphasize dyslipidemia as one of the main contributors for this risk factor. The dyslipidemia commonly associated to GI is characterized by hypertriglyciridemia, low HDL-C and the presence of a small and dense LDL. However, since associated LDL-C levels with the development of premature atherosclerosis in non diabetic individuals is for the most part not observed in GI patients, it is questioned whether other lipid metabolism alterations such as cholesterol kinetics or the lipid transfer to HDL could be related to a greater CVD risk in these individuals. A previous study using an artificial LDL nanoemulsion showed a faster removal rate of the free cholesterol in normolipidemic with coronary artery disease (CAD) patients when compared to control individuals. In this study an artificial lipid nanoemulsion was used to evaluate both these processes involved in the metabolism of LDL and HDL which are both altered in patients with GI that expose them to CAD, and relating the results to CVD factors such as insulin resistance, obesity and dyslipidemia. 14 GI and 15 control individuals participated in this study. All without manifestations of CVD, none using any oral antidiabetic medication or hypolipimeants, paired for age, sex, race, BMI, smoking, alcoholic consumption, physical activity and comorbidities. For the kinetic study, a labeled nanoemulsion was interveneously injected and blood samples collected at determined intervals over a 24 hour period to determine the radiactive plasma decay curves and fractional clearance rate (FCR) of the labeled nanoemulsion lipids through a compartmental analysis model. Plasma esterification rate of the 3H-free cholesterol of the nanoemulsion was measured as was the in vitro transfer from the nanoemulsion to HDL fraction. Insulin resistance was obtained by the glycemic homeostasis mathematical model (HOMA) and abdominal adipose by a computerized tomography of the abdomen. No differences were observed for total cholesterol plasmatic concentrations, LDL-C, HDL-C, triglycerides or apolipoproteins between the two groups. The anthropometric profile related to weight, BMI and abdominal circumference was similar for both groups. The GI group presented higher fasting insulin concentration (p=0.01), less insulin sensitivity (p=0.01) and a greater insulin resistance (p=0.01). The TFR 14C-CE was similar in both groups, although the TFR 3H-CL was faster in the GI group compared to the control group (p=0.04). The esterification percentage of the nanoemulsions 3H-colesterol, as well as the lipid transfer from the nanoemulsion to HDL fraction were similar for both groups. The faster 3H-free cholesterol removal shows that a dissociation of the cholesterol particles of the lipidic nanoemulsion occurred in those patients with GI. This dissociation could possibly reflect alterations in the intravascular LDL lipoprotein metabolism which in turn, may favor atherogenesis in these patients

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