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Impedimetric immunosensor for electronegative low density lipoprotein (LDL(-)) based on monoclonal antibody adsorbed on (polyvinyl formal)-gold nanoparticles matrix

OLIVEIRA, Maria D. L.; ABDALLA, Dulcineia S. P.; GUILHERME, Daniel F.; FAULIN, Tanize E. S.; ANDRADE, Cesar A. S.
Fonte: ELSEVIER SCIENCE SA; AMSTERDAM Publicador: ELSEVIER SCIENCE SA; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
98.07168%
Monoclonal antibodies (MAb) have been commonly applied to measure LDL in vivo and to characterize modifications of the lipids and apoprotein of the LDL particles. The electronegative low density lipoprotein (LDL(-)) has an apolipoprotein B-100 modified at oxidized events in vivo. In this work, a novel LDL-electrochemical biosensor was developed by adsorption of anti-LDL(-) MAb on an (polyvinyl formal)-gold nanoparticles (PVF-AuNPs)-modified gold electrode. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to characterize the recognition of LDL-. The interaction between MAb-LDL(-) leads to a blockage in the electron transfer of the [Fe(CN)(6)](4-)/K(4)[Fe(CN)(6)](3-) redox couple, which may could result in high change in the electron transfer resistance (R(CT)) and decrease in the amperometric responses in CV analysis. The compact antibody-antigen complex introduces the insulating layer on the assembled surface, which increases the diameter of the semicircle, resulting in a high R(CT), and the charge transferring rate constant k(0) decreases from 18.2 x 10(-6) m/s to 4.6 x 10(-6) m/s. Our results suggest that the interaction between MAb and lipoprotein can be quantitatively assessed by the modified electrode. The PVF-AuNPs-MAb system exhibited a sensitive response to LDL(-)...

Natural, but not lyophilized, low density lypoproteins were an acceptable alternative to egg yolk for cryopreservation of ram semen

MOUSTACAS, V. S.; ZAFFALON, F. G.; LAGARES, M. A.; LOAIZA-ECCHEVERRI, A. M.; VARAGO, F. C.; NEVES, M. M.; HENEINE, L. G. D.; ARRUDA, R. P.; HENRY, M.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
77.776807%
The objective was to evaluate the suitability of using natural or lyophilized low density lipoproteins (LDL), in lieu of whole egg yolk, in extenders for cryopreserving ram semen. Once extragonadal sperm reserves were depleted in 10 fertile Santa Ines cross rams, two ejaculates per ram were collected for cryopreservation. Nine extenders were used: Tris-16% egg yolk extender with 5% glycerol as a control (T1), and substitution of whole egg yolk with 8, 12, 16 or 20% natural LDL (T2-T5, respectively), or with 8, 12, 16, or 20% lyophilized LDL (T6-T9). Semen was diluted to 100 X 10(6) sperm/mL, packaged into 0.25 mL straws, cooled, held at 5 C for 3 h, and then frozen in liquid nitrogen vapor. Immediately after thawing (37 degrees C for 30 s), sperm total and progressive motility, and kinetic parameters were analyzed with computer assisted semen analysis (CASA). Percentage of sperm with plasma membrane functional integrity was assessed by the hypoosmotic swelling test (HOST), sperm membrane physical integrity with propidium iodide (PI), and acrosome integrity with FITC-PSA using an epifluorescent microscope. For all sperm end points, there was no difference between the control and natural LDL treatments (P > 0.05): total motility (T1: 20.9 +/- 11.9 and average of T2-T5: 25.9 +/- 13.6%; mean SD)...

Electronegative Low-Density Lipoprotein is Associated with Dense Low-Density Lipoprotein in Subjects with Different Levels of Cardiovascular Risk

MELLO, Ana Paula de Queiroz; SILVA, Isis Tande da; OLIVEIRA, Aline Silva; NUNES, Valeria Sutti; ABDALLA, Dulcineia Saes Parra; GIDLUND, Magnus; DAMASCENO, Nagila Raquel Teixeira
Fonte: SPRINGER HEIDELBERG Publicador: SPRINGER HEIDELBERG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
98.3412%
Dyslipidemias and physicochemical changes in low-density lipoprotein (LDL) are very important factors for the development of coronary artery disease (CAD). However, pathophysiological properties of electronegative low-density lipoprotein [LDL(-)] remain a controversial issue. Our objective was to investigate LDL(-) content in LDL and its subfractions (phenotypes A and B) of subjects with different cardiovascular risk. Seventy-three subjects were randomized into three groups: normolipidemic (N; n = 30) and hypercholesterolemic (HC; n = 33) subjects and patients with CAD (n = 10). After fasting, blood samples were collected and total, dense and light LDL were isolated. LDL(-) content in total LDL and its subfractions was determined by ELISA. LDL(-) content in total LDL was lower in the N group as compared to the HC (P < 0.001) and CAD (P = 0.006) groups. In the total sample and in those of the N, HC, and CAD groups, LDL(-) content in dense LDL was higher than in light LDL (P = 0.001, 0.001, 0.001, and 0.033, respectively) The impact of LDL(-) on cardiovascular risk was reinforced when LDL(-) content in LDL showed itself to have a positive association with total cholesterol (beta = 0.003; P < 0.001), LDL-C (beta = 0.003; p < 0.001), and non-HDL-C (beta = 0.003; P < 0.001) and a negative association with HDL-C (beta = -0.32; P = 0.04). Therefore...

Validation of a novel ELISA for measurement of electronegative low-density lipoprotein

FAULIN, Tanize do Espirito Santo; SENA, Karine Cavalcanti Mauricio de; TELLES, Andreia Elisa Rodrigues; GROSSO, Daniela de Mattos; FAULIN, Edson Jose Bernardi; ABDALLA, Dulcineia Saes Parra
Fonte: WALTER DE GRUYTER & CO Publicador: WALTER DE GRUYTER & CO
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
97.95935%
Background: Oxidative modification of low-density lipoprotein (LDL) plays a key role in the pathogenesis of atherosclerosis. LDL(-) is present in blood plasma of healthy subjects and at higher concentrations in diseases with high cardiovascular risk, such as familial hypercholesterolemia or diabetes. Methods: We developed and validated a sandwich ELISA for LDL(-) in human plasma using two monoclonal antibodies against LDL(-) that do not bind to native LDL, extensively copper-oxidized LDL or malondialdehyde-modified LDL. The characteristics of assay performance, such as limits of detection and quantification, accuracy, inter- and intra-assay precision were evaluated. The linearity, interferences and stability tests were also performed. Results: The calibration range of the assay is 0.625-20.0 mU/L at 1: 2000 sample dilution. ELISA validation showed intra- and inter- assay precision and recovery within the required limits for immunoassays. The limits of detection and quantification were 0.423 mU/L and 0.517 mU/L LDL(-), respectively. The intra- and inter- assay coefficient of variation ranged from 9.5% to 11.5% and from 11.3% to 18.9%, respectively. Recovery of LDL(-) ranged from 92.8% to 105.1%. Conclusions: This ELISA represents a very practical tool for measuring LDL(-) in human blood for widespread research and clinical sample use. Clin Chem Lab Med 2008; 46: 1769-75.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Conselho Nacional de Pesquisa e Desenvolvimento Cientifico (CNPq)

Analytical quantification of low-density lipoprotein using europium tetracycline indicator

SILVA, Flavia Rodrigues De Oliveira; Monteiro, Andrea Moreira; Figueiredo Neto, Antonio Martins; Gidlund, Magnus Ake; Vieira Junior, Nilson Dias; COURROL, Lilia Coronato
Fonte: JOHN WILEY & SONS LTD Publicador: JOHN WILEY & SONS LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
98.07168%
Low-density lipoprotein (LDL) is known as `bad` cholesterol. If too much LDL circulates in the blood it can be retained in the walls of the arteries, causing atherosclerosis. In this paper we showed an alternative method to quantify LDL using the europium tetracycline (EuTc) indicator. The optical properties of the EuTc complex were investigated in aqueous solutions containing LDL. An enhancement was observed of the europium luminescence in the solutions with LDL compared those without the lipoprotein. A method to quantify the amount of LDL in a sample, based on EuTc enhanced luminescence, is proposed. The enhancement mechanism is also discussed. Copyright (C) 2009 John Wiley & Sons, Ltd.; FAPESP; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); CNPq; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); IMFCx (Instituto do Milenio de Fluidos Complexos); IMFCx (Instituto do Milenio de Fluidos Complexos)

Hydroxychloroquine reduces low-density lipoprotein cholesterol levels in systemic lupus erythematosus: a longitudinal evaluation of the lipid-lowering effect

Cairoli, E.; Rebella, M.; Danese, N.; Garra, V.; Borba, E. F.
Fonte: SAGE PUBLICATIONS LTD; LONDON Publicador: SAGE PUBLICATIONS LTD; LONDON
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
78.064966%
The influence of antimalarials on lipids in systemic lupus erythematosus (SLE) has been identified in several studies but not in many prospective cohorts. The aim of this study was to longitudinally determine the effect of antimalarials on the lipoprotein profile in SLE. Patients and methods: Fasting total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL) and low-density lipoprotein cholesterol (LDL) plasma levels were determined at entry and after 3 months of hydroxychloroquine (HCQ) treatment in a longitudinal evaluation of 24 patients with SLE. Results: a significant decrease in TC (198 +/- 33.7 vs. 183 +/- 30.3 mg/dl, p = 0.023) and LDL levels (117 +/- 31.3 vs. 101 +/- 26.2 mg/dl, p = 0.023) were detected after the 3 months of HCQ therapy. The reduction of 7.6% in TC (p = 0.055) and 13.7% in LDL levels (p = 0.036) determined a significant decrease in the frequency of dyslipidemia (26% vs. 12.5%, p = 0.013) after HCQ therapy. Conclusion: This longitudinal study demonstrated the beneficial effect of antimalarials on lipids in SLE since this therapy induced a reduction of atherogenic lipoproteins. Lupus (2012) 21, 1178-1182.; Programa para la Investigacion Biomedica PROINBIO, Facultad de Medicina, Universidad de la Republica; Programa para la Investigacion Biomedica PROINBIO...

Lipoproteína de baixa densidade eletronegativa (LDL-) em indivíduos com diferentes níveis de risco cardiovascular: parâmetros nutricionais e bioquímicos ; Electronegative low density lipoprotein (LDL-) in subjects with different levels of cardiovascular risk: nutritional and biochemical parameters

Mello, Ana Paula de Queiroz
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 31/05/2007 PT
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98.01031%
Introdução: As dislipidemias representam um dos principais fatores de risco para as doenças cardiovasculares e, particularmente, para a aterosclerose. Portanto, todos os fatores nutricionais capazes de reduzir a sua incidência ou melhorar seu quadro clínico, representam ferramentas importantes para sua prevenção ou tratamento. Além das dislipidemias, as modificações oxidativas da lipoproteína de baixa densidade (LDL) têm relação direta com o processo aterosclerótico. Objetivos: O objetivo deste estudo foi avaliar a possível influência dos Parâmetros Nutricional (alimentar e antropométrico) e Bioquímicos sobre a geração de LDL- em indivíduos com diferentes níveis de risco cardiovascular Métodos: Para a consecução destes objetivos foram avaliados indivíduos com hipercolesterolemia associada à LDL com (n = 10) ou sem (n = 33) aterosclerose, quando comparados aos indivíduos normocolesterolêmicos (n = 30). A partir desta amostra avaliou-se o hábito alimentar (questionário quantitativo de freqüência alimentar), a antropometria (peso, altura, circunferência da cintura, % de gordura corporal e % de massa magra), o perfil lipídico (colesterol e triacilgliceróis), o conteúdo de LDL- (plasma, LDL total e sub-frações de LDL) e os auto-anticorpos anti-LDL- no plasma. O diagnóstico de aterosclerose foi feito através da pesquisa dos prontuários e da avaliação do índice tornozelo-braço (ITB). Resultados: A análise do perfil lipídico indicou que a concentração de colesterol plasmático no grupo Controle (180...

Influência do pH na interação do Photofrin®, Photogem® e Photosan® com DMPC e lipoproteína de baixa densidade; Influence of the pH in the interaction of Photofrin®, Photogem® and Photosan® with DMPC and low density lipoprotein

Natal, Aline Martins Duboc
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 21/09/2007 PT
Relevância na Pesquisa
77.988867%
O efeito do fotossensibilizador na estrutura biológica não é apenas influenciado por suas propriedades fotofísicas, mas também por sua interação específica com biosistemas.Além disso, a localização do fotossensibilizador no tecido tumoral é um importante fator que resulta em diferentes mecanismos de destruição do tumor. Muitos fotossensibilizadores, após administração sistêmica, se ligam às proteínas plasmáticas e com isso são distribuídos em diferentes sítios no organismo. Os fotossensibilizadores hidrofílicos são largamente transportados por albuminas e globilinas e se acumulam preferencialmente no estroma vascular dos tumores. Entretanto, fotossensibilizadores mais hidrofóbicos se ligam às lipoproteínas, principalmente LDL, que promove a entrada do FS na célula através de endocitose mediado por receptor. Sendo assim, a localização do FS depende de sua ligação com as deferentes proteínas plasmáticas, sua farmacocinética e também é influenciada pela diferença entre o tecido normal e tumoral. O tecido tumoral tem pH mais baixo e maior expressão de receptores de LDL do que os tecidos normais, aumentando a seletividade dos FSs as células tumorais. A incorporação de FS hidrofóbicos em lipossomas para a administração sistêmica pode realçar ao transporte deste pelas lipoproteínas. No presente trabalho estudou-se a influência do pH na interação de fotossensibilizadores com lipossomas de DMPC e LDL. Os fotossensibilizadores utilizados nesse estudo foram Photofrin®...

Caracterização de lipoproteína de baixa densidade (LDL) por meios espectroscópicos; Characterization of low density lipoprotein (LDL) by spectroscopic methods

Sicchieri, Letícia Bonfante
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 01/08/2012 PT
Relevância na Pesquisa
97.95935%
O presente trabalho tem como objetivo avaliar se o complexo Európio- Clorotetraciclina (EuCTc) ou o corante Tioflavina T (ThT) podem atuar como biossensores precisos e eficientes de colesterol numa fração específica, através de procedimentos simples. Para isso estudaram-se as propriedades ópticas do complexo EuCTc e ThT na presença da Lipoproteína de Baixa Densidade (LDL) em seu estado nativo e em seu estado oxidado. O primeiro estudo realizado verificou a melhor razão molar entre o Európio e a Clorotetraciclina, em seguida verificou-se a influência da diálise da LDL na emissão do complexo EuCTc, para obtenção de um protocolo para quantificação da concentração da LDL. Foram traçadas as curvas de calibração da emissão do complexo EuCTc com várias concentrações da LDL nativa, LDL oxidada com íons de Cobre e LDL oxidada com íons de Ferro. Em seguida obteve-se o tempo de vida do íon Európio no complexo EuCTc na presença de diferentes concentrações de LDL nativa e LDL oxidada por íons de Cobre. Na segunda parte do trabalho estudou-se a emissão do corante Tioflavina T na presença da LDL nativa e LDL oxidada. Na terceira etapa as propriedades ópticas dos biossensores EuCTc e ThT foram investigadas na presença do plasma sanguíneo e foram comparadas às emissões do complexo EuCTc e o corante ThT com a LDL ultracentrifugada...

Influência do ω-3 sobre a lipoproteína de baixa densidade eletronegativa [LDL(-)], anticorpos LDL(-) e tamanho das partículas de LDL em indivíduos com síndrome metabólica; Influence of ω-3 over electronegative low density lipoprotein [LDL(-)] plasma concentrations, antiLDL(-) and LDL particles in individuals with metabolic syndrome

Estevez Fernandez, Diana Gabriela
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/03/2015 PT
Relevância na Pesquisa
77.771973%
Introdução A Síndrome Metabólica (SM) representa um conjunto de fatores que determinam maior risco para Doença Cardiovascular (DCV), devido principalmente à Resistência à Insulina (RI) e ao estado inflamatório promovido pelo tecido adiposo branco hipertrofiado. Nesse contexto, a condição de dislipidemia favorece o desenvolvimento da aterosclerose, devido a que maiores concentrações de lipoproteína de baixa densidade (LDL) no plasma podem propiciar modificações nessas partículas. Essas modificações podem ter origem oxidativa ou não oxidativa e impactar nas características aterogênicas da LDL. O ômega três tem mostrado efeitos hipolipemiantes e anti-inflamatórios, que podem reduzir o risco cardiovascular de indivíduos com SM. Objetivo:: avaliar o efeito da suplementação de 3g de ω-3 por um período de oito semanas sobre a concentração plasmática das partículas de LDL eletronegativas [LDL(-)] e seus anticorpos, assim como monitorar possíveis mudanças nas concentrações das subfrações das LDL. Metodologia: Foram incluídos 115 participantes de ambos os sexos, entre 30 e 74 anos, com SM, separados nos grupos de intervenção com ω-3 (n=58) e controle com ω-9 (n=57). Foram realizadas análises de perfil lipídico e por meio de ELISA foram avaliadas a concentração de LDL(-) e de antiLDL(-) no plasma dos participantes. O tamanho das subfrações de LDL foi realizado no sistema Lipoprint. O efeito do tempo e das intervenções foi testado por meio do programa SPSS versão 20.0...

Intensified peginterferon α-2a dosing increases sustained virologic response rates in heavy, high viral load hepatitis c genotype 1 patients with high low-density lipoprotein

Harrison, Stephen A.; Abdurakhmanov, Djamal; Shiffman, Mitchell L.; Bakulin, Igor; Mazur, Wlodzimierz; Rodriguez-Torres, Maribel; Silva, Giovanni Faria; Cheinquer, Hugo; Messinger, Diethelm; Connell, Edward V.; McKenna, Michael; Tatsch, Fernando; Reddy, K
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 271-279
ENG
Relevância na Pesquisa
98.28005%
BACKGROUND AND GOAL: Patients infected with hepatitis C virus (HCV) with elevated low-density lipoprotein (LDL) levels achieve higher sustained virologic response (SVR) rates after peginterferon (PegIFN)/ribavirin treatment versus patients with lower LDL. Our aim was to determine whether SVR rates in patients with low/elevated LDL can be improved by dose intensification. STUDY: In PROGRESS, genotype 1 patients with baseline HCV RNA≥400,000 IU/mL and body weight ≥85 kg were randomized to 48 weeks of 180 μg/wk PegIFN α-2a (40 kDa) plus ribavirin (A: 1200 mg/d; B: 1400/1600 mg/d) or 12 weeks of 360 μg/wk PegIFN α-2a followed by 36 weeks of 180 μg/wk, plus ribavirin (C: 1200 mg/d; D: 1400/1600 mg/d). This retrospective analysis assessed SVR rates among patients with low (<100 mg/dL) or elevated (≥100 mg/dL) LDL. Patients with high LDL (n=256) had higher baseline HCV RNA (5.86×10 IU/mL) versus patients with low LDL (n=262; 4.02×10 IU/mL; P=0.0003). RESULTS: Multiple logistic regression analysis identified a significant interaction between PegIFN α-2a dose and LDL levels on SVR (P=0.0193). The only treatment-related SVR predictor in the nested multiple logistic regression was PegIFN α-2a dose among patients with elevated LDL (P=0.0074); therefore...

Cardiovascular complications and increased levels of circulating modified low density lipoprotein in HIV patients and patients with lipodystrophy

Ronchini,K.R.O.M.; Duarte,A.J.S.; Casseb,J.S.R.; Gidlund,M.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2004 EN
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The introduction of highly active antiretroviral therapy (HAART) for patients infected with HIV has significantly prolonged the life expectancy and to some extent has restored a functional immune response. However, the premature introduction of HAART has led to a significant and alarming increase in cardiovascular complications, including myocardial infarction and the appearance of abnormal distribution of body fat seen as lipodystrophy. One key element in the development of ischemic coronary artery disease is the presence of circulating and tissue-fixed modified low density lipoprotein (mLDL) that contributes to the initiation and progression of arterial lesions and to the formation of foam cells. Even though not completely elucidated, the most likely mechanism involves mLDL in the inflammatory response and the induction of a specific immune response against mLDL. Circulating antibodies against mLDL can serve as an indirect marker of the presence of circulating and vessel-fixed mLDL. In the present study, we measured antibodies to mLDL and correlated them with immune status (i.e., number of CD4+ T cells) in 59 HIV patients and with the clinical manifestation of lipodystrophy in 10 patients. We observed a significant reduction in anti-mLDL antibody levels related both to lipodystrophy and to an immunocompromised state in HIV patients. We speculate that these antibodies may explain in part the rapid development of ischemic coronary artery disease in some patients.

High levels of LDL-C combined with low levels of HDL-C further increase platelet activation in hypercholesterolemic patients

Chan,L.W.; Luo,X.P.; Ni,H.C.; Shi,H.M.; Liu,L.; Wen,Z.C.; Gu,X.Y.; Qiao,J.; Li,J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 EN
Relevância na Pesquisa
78.18699%
High levels of low-density lipoprotein cholesterol (LDL-C) enhance platelet activation, whereas high levels of high-density lipoprotein cholesterol (HDL-C) exert a cardioprotective effect. However, the effects on platelet activation of high levels of LDL-C combined with low levels of HDL-C (HLC) have not yet been reported. We aimed to evaluate the platelet activation marker of HLC patients and investigate the antiplatelet effect of atorvastatin on this population. Forty-eight patients with high levels of LDL-C were enrolled. Among these, 23 had HLC and the other 25 had high levels of LDL-C combined with normal levels of HDL-C (HNC). A total of 35 normocholesterolemic (NOMC) volunteers were included as controls. Whole blood flow cytometry and platelet aggregation measurements were performed on all participants to detect the following platelet activation markers: CD62p (P-selectin), PAC-1 (GPIIb/IIIa), and maximal platelet aggregation (MPAG). A daily dose of 20 mg atorvastatin was administered to patients with high levels of LDL-C...

Effect of low density lipoprotein on the quality of cryopreserved dog semen

Varela Junior, Antonio Sergio; Corcini, Carine Dahl; Ulguim, Rafael da Rosa; Alvarenga, Marcus Vinicius; Bianchi, Ivan; Corrêa, Marcio Nunes; Lucia Junior, Thomaz; Deschamps, João Carlos
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
97.95935%
Egg yolk is included in extenders for semen cryopreservation due to its protective effect against cold shock,which is attributed to the presence of low density lipoprotein (LDL). This study evaluates how semen quality is affected by using LDL as a replacement for egg yolk in extenders for cooled and frozen dog semen. In Experiment 1 semen was extended in TRIS–glucoseat5ºC, in four treatments: 20% egg yolk (T1); 6% (T2); 8% (T3); and 10% LDL (T4). Spermmotility and membrane integrity after 24, 48, 72 and 96 hand the 50% conservation rate of motil espermatozoa (50M) were evaluated. The 50 M was less for T1 than for the other treatments (P <0.01), but T2–T4 did not differ (P >0.05). In Experiment 2, glycerol at 10% was included in the freezing extender, in treatments similar to those from Experiment 1. Spermmotility and membrane integrity did not differ for T2, T3 and T4 at any period in Experiment 1 and after thawing in Experiment 2 (P >0.05), but were greater for all LDL treatments than for T1 (P <0.01), in both experiments. Thus, LDL can replace egg yolk in the composition of the TRIS–glucose extender for cooled or frozen dog semen.

Effect of low density lipoprotein on the quality of cryopreserved dog semen

Varela Junior, Antonio Sergio; Corcini, Carine Dahl; Ulguim, Rafael da Rosa; Alvarenga, Marcus Vinicius Figueira de; Bianchi, Ivan; Corr??a, Marcio Nunes; Lucia Junior, Thomaz; Deschamps, Jo??o Carlos
Fonte: Universidade Federal de Pelotas Publicador: Universidade Federal de Pelotas
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
97.95935%
Egg yolk is included in extenders for semen cryopreservation due to its protective effect against cold shock, which is attributed to the presence of low density lipoprotein (LDL). This study evaluates howsemen quality is affected by using LDL as a replacement for egg yolk in extenders for cooled and frozen dog semen. In Experiment 1, semenwas extendedinTRIS???glucose at 5 ???C, in four treatments:20% egg yolk (T1); 6% (T2); 8% (T3); and 10% LDL (T4). Spermmotility and membrane integrity after 24, 48, 72 and 96 h and the 50% conservation rate of motile spermatozoa (50M) were evaluated. The 50M was less for T1 than for the other treatments (P < 0.01), but T2???T4 did not differ (P > 0.05). In Experiment 2, glycerol at 10% was included in the freezing extender, in treatments similar to those fromExperiment 1. Spermmotility and membrane integrity did not differ for T2, T3 and T4 at any period in Experiment 1 and after thawing in Experiment 2 (P > 0.05), but were greater for all LDL treatments than for T1 (P < 0.01), in both experiments. Thus, LDL can replace egg yolk in the composition of the TRIS???glucose extender for cooled or frozen dog semen.

Red wine and fractionated phenolic compounds prepared from red wine inhibit low density lipoprotein oxidation in vitro

Kerry, Nicole Louise; Abbey, Mavis
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Artigo de Revista Científica
Publicado em //1997 EN
Relevância na Pesquisa
87.95935%
The oxidative modification of low density lipoproteins (LDL) has been implicated in the development of atherosclerosis. This study examined the effect of red wine, ethanol and red wine stripped of phenols on copper-mediated and azo-initiated LDL oxidation. Red wine containing phenolic compounds (0.025–20 mg:l gallic acid equivalents) increased the lag time of conjugated diene formation, inhibited the generation of thiobarbituric acid reactive substances (TBARS) and decreased the relative electrophoretic mobility of LDL in a concentration-dependent manner. These changes were not apparent in LDL incubated with ethanol or red wine stripped of phenols. In other experiments, red wine (75 mg:l gallic acid equivalents) was incubated with plasma at 37°C for 3 h. The LDL isolated from this plasma displayed a 60% increase in lag time following copper-mediated oxidation. Uptake of this LDL by cultured J774 macrophages was three-fold lower than control LDL. Red wine was fractionated into phenolic acids (fraction 1), catechins and monomeric anthocyanidins (fraction 2), flavonols (fraction 3) and polymeric anthocyanidins (fraction 4). All red wine fractions prolonged the time before LDL oxidation. Fraction 2 displayed a significantly greater antioxidant activity than fractions 3 and 4 (but not fraction 1) in at least one pro-oxidant model. In conclusion we have shown that antioxidant compounds in red wine can associate with LDL particles following an incubation in whole plasma...

The effect of natural dietary antioxidants on low density lipoprotein oxidation and atherosclerosis / Nicole Louise Kerry.

Kerry, Nicole Louise
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 695030 bytes; application/pdf
Publicado em //1997 EN
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Investigates the in vitro antioxidant properties of red wine containing polphends and the isoflavone genistein. Subsequently the effect of red wine on low density lipoprotein oxidation and fatty streak lesion development in cholesterol-fed rabbits was examined.; Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, 1998; Includes bibliographical references (34 leaves).; xxi, 204 leaves : ill. ; 30 cm.; Title page, contents and abstract only. The complete thesis in print form is available from the University Library.

Achievement of 2011 European low-density lipoprotein cholesterol (LDL-C) goals of either <70 mg/dl or ≥50% reduction in high-risk patients: results from VOYAGER; Achievement of 2011 European low-density lipoprotein cholesterol (LDL-C) goals of either <70 mg/dl or >/-50% reduction in high-risk patients: results from VOYAGER

Karlson, B.; Nicholls, S.; Lundman, P.; Palmer, M.; Barter, P.
Fonte: Elsevier Science Ireland Publicador: Elsevier Science Ireland
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
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OBJECTIVE: Guidelines published in 2011 by the European Atherosclerosis Society and the European Society of Cardiology recommend a goal of either low-density lipoprotein cholesterol (LDL-C) <70 mg/dl (~1.8 mmol/l) or ≥ 50% reduction in LDL-C for patients at very high cardiovascular risk. The aim of this study was to determine the percentage of high-risk patients from the VOYAGER individual patient data meta-analysis treated with rosuvastatin 10-40 mg, atorvastatin 10-80 mg or simvastatin 10-80 mg who achieved this goal. METHODS: We analysed 25,075 patient exposures from high-risk patients. Paired comparisons were made between each rosuvastatin dose and an equal or higher dose of either atorvastatin or simvastatin, with a series of meta-analyses that included only randomised studies that directly compared rosuvastatin and its comparator treatments. RESULTS: As statin dose increased, higher percentages of patients achieved LDL-C <70 mg/dl or ≥ 50% LDL-C reduction. A greater percentage achieved this goal with rosuvastatin 10-40 mg (43.8-79.0%) than with equal or double milligram doses of atorvastatin (16.1-65.2%) or simvastatin (0-39.7%). Paired comparisons showed statistically significant differences for: rosuvastatin 10 mg vs. atorvastatin 10-20 mg and simvastatin 10-20 mg; rosuvastatin 20 mg vs. atorvastatin 20-40 mg and simvastatin 20-80 mg; and rosuvastatin 40 mg vs. atorvastatin 40-80 mg and simvastatin 40-80 mg (all p < 0.001). CONCLUSION: These data from VOYAGER highlight the importance of an effective statin at an appropriate dose to achieve treatment goals for LDL-C in patients with very high cardiovascular risk.; Björn W. Karlson...

Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise

Harrison, Michael; Moyna, Niall M; Zderic, Theodore W; O'Gorman, Donal J; McCaffrey, Noel; Carson, Brian P; Hamilton, Mart T
Fonte: BioMed Central Publicador: BioMed Central
Tipo: info:eu-repo/semantics/article; all_ul_research; ul_published_reviewed
ENG
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peer-reviewed; Background: Many of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS), it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects.Methods: Using a randomized cross-over design, very low density lipoprotein (VLDL) responses were evaluated in eight men on the morning after i) an inactive control trial (CON), ii) exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF), and iii) after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL).Results: The intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG) determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70-120 nm (large) particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43-55 nm (medium) particle range. VLDL-TG in smaller particles (29-43 nm) was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change...

Behavior of the thermal diffusivity of native and oxidized human low-density lipoprotein solutions studied by the Z-scan technique

Santos, Priscila Ribeiro dos; Genaro-Mattos, Thiago C.; Monteiro, Andrea Moreira; Miyamoto, Sayuri; Figueiredo Neto, Antonio Martins
Fonte: SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS; BELLINGHAM Publicador: SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS; BELLINGHAM
Tipo: Artigo de Revista Científica
ENG
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Modifications in low-density lipoprotein (LDL) have emerged as a major pathogenic factor of atherosclerosis, which is the main cause of morbidity and mortality in the western world. Measurements of the heat diffusivity of human LDL solutions in their native and in vitro oxidized states are presented by using the Z-Scan (ZS) technique. Other complementary techniques were used to obtain the physical parameters necessary to interpret the optical results, e. g., pycnometry, refractometry, calorimetry, and spectrophotometry, and to understand the oxidation phase of LDL particles. To determine the sample's thermal diffusivity using the thermal lens model, an iterative one-parameter fitting method is proposed which takes into account several characteristic ZS time-dependent and the position-dependent transmittance measurements. Results show that the thermal diffusivity increases as a function of the LDL oxidation degree, which can be explained by the increase of the hydroperoxides production due to the oxidation process. The oxidation products go from one LDL to another, disseminating the oxidation process and caring the heat across the sample. This phenomenon leads to a quick thermal homogenization of the sample, avoiding the formation of the thermal lens in highly oxidized LDL solutions. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JBO.17.10.105003]; National Counsel for Scientific and Technological Development (CNPq); National Counsel for Scientific and Technological Development (CNPq); Sao Paulo Research Foundation (FAPESP); Sao Paulo Research Foundation (FAPESP); National Institute of Science and Technology of Complex Fluid (INCTFCx); National Institute of Science and Technology of Complex Fluid (INCT-FCx); Redoxoma (INCT-Redoxoma); Redoxoma (INCTRedoxoma)