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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.
191

Obtenção de GFP5-scFv recombinante reativo à LDL(-): possíveis aplicações na investigação da aterosclerose / Obtaining GFP5-scFv recombinant reactive LDL (-): possible applications in research of atherosclerosis

Daniel Ferreira Guilherme 12 September 2012 (has links)
A aterosclerose é a doença de base das principais complicações cardiovasculares. Os produtos de modificação das lipoproteínas de baixa densidade, como a subfração eletronegativa LDL (-), exercem um importante papel na progressão da aterosclerose. O objetivo do presente trabalho foi expressar a proteína de fusão, GFP5-scFv anti-LDL (-), desenvolver um método para detecção de LDL (-), assim como avaliar a possível utilização desta proteína como uma ferramenta para monitorar os ensaios de formação de células espumosas. A proteína GFP5-scFv anti-LDL (-) foi expressa em E. coli BL21DE3. Esta proteína de fusão foi desnaturada com 7M de ureia, purificada por cromatografia de afinidade e reenovelada por gradiente de diálise na presença de poliestireno sulfonado. A massa molecular da proteína foi confirmada por SDS-PAGE e sua afinidade de ligação à LDL (-) confirmada pelo dot blot e ELISA. O espectro de emissão de fluorescência da GFP5-scFv anti-LDL (-) é qualitativamente equivalente ao da GFP5, porém com intensidade de emissão mais baixa. Na tentativa de superar essa limitação tentou-se realizar a inserção de um peptídeo ligante flexível entre os domínios de ligação da GFP5 e do scFv anti-LDL (-) para melhorar a eficiência de emissão de fluorescência da quimera. Os ensaios in vitro com macrófagos RAW 264.7 demonstraram que a GFP5-scFv anti-LDL (-) não apresentou toxicidade significante e não reduziu a captação de LDL (-) pelos macrófagos. Demonstrou-se por microscopia confocal, que a GFP5-scFv anti-LDL é internalizada pelos macrófagos e pode ser visualizada no interior destas células. Portanto, a proteína recombinante GFP5-scFv anti-LDL (-) é uma ferramenta que poderá ser utilizada em ensaios in vitro com macrófagos para o estudo da aterosclerose. / Atherosclerosis is the most important cause of the cardiovascular diseases. The modifications of low density lipoproteins that induces the formation of modified particles, like the electronegative LDL subfraction, - LDL (-), are know to play a key role in the progression of atherosclerosis. The aim of the present work was to express a fusion protein, GFP5-scFv anti LDL (-), to develop a method to assess LDL (-), as well as to evaluate the use of this protein as a tool for in vitro assay in the investigation of atherosclerosis. The protein GFP5-scFv anti LDL (-) was expressed in E. Coli BL21DE3. The fusion protein was denatured with 7M urea, purified by affinity chromatografy and refolded by gradient dialysis in the presence of PSS. The molecular mass of the protein was confirmed by SDS-PAGE and its affinity for LDL (-) was confirmed by dot blot and ELISA. The emission spectrum of GFP5-scFv is qualitatively equivalent to that of GFP5, although with a lower fluorescence emission intensity. In an attempt to overcome this limitation we tried to perform the insertion of a flexible linker between the binding domains of GPF5 and scFv was done in order to increase the fluorescence emission of this fusion protein. The in vitro assays with RAW 264.7 macrophages showed that the GFP5-scFv anti-LDL (-) has no significant toxicity to these cells and did not decrease the uptake of LDL (-) by these macrophages. It was demonstrated by confocal microscopy that the GFP5-scFv anti-LDL (-) is internalized by macrophages and can be visualized inside these cells. Thus, GFP5-scFv anti-LDL (-) fusion proteins is a useful to that can be used for in vitro assays with macrophages in the investigation of atherosclerosis.
192

Criopreservação de sêmen de galos / Roosters sperm cryopreservation

Laan, Guilherme Martino Van Der 30 November 2007 (has links)
Made available in DSpace on 2014-08-20T13:32:51Z (GMT). No. of bitstreams: 1 dissertacao_guilherme_van_der_laan.pdf: 723829 bytes, checksum: 399e8e1ec5f5ec9b7f77f1ffa1d0af80 (MD5) Previous issue date: 2007-11-30 / Adding extenders to poultry semen is currently used in artificial insemination programs to optimize the management of genetically superior males. Fresh semen fertility usually declines after 1 hour of collection, raising the need to use diluents and low temperatures to store semen for longer periods. Low density lipoprotein (LDL), extracted from the egg yolk, is used as a component of various mammalian semen diluents, however its application on poultry semen has not been evaluated. Regarding cryopreservation, different methodologies have been developed during the past years. One alternative is to use dimethylacetamide (DMA) as a cryoprotectant. The best results with DMA are obtained when semen is subjected to ultra-fast freezing, in pellets, and to a fast thawing at 60ºC. The objective of this work was to establish protocols to preserve rooster sperm, focusing on the use of LDL as a component of the refrigeration diluent, and on DMA as a internal cryoprotectant for freezing. To reach these objectives, the effect of adding different levels of LDL liposomes to the cooling diluent, upon the quality characteristics of semen refrigerated at 5 °C, was evaluated. The quality of semen frozen with DMA, packed in straws or pellets, and thawed in three different temperatures was also evaluated. The results obtained allow to conclude that: adding 6% of LDL liposomes to the cooling diluent preserves the general sperm quality, suggesting that improvements on fertility could be obtained if a limit in lipoprotein supplementation is imposed; body temperature (40°C) is most suitable for thawing sperm frozem with DMA; and packing sperm in straws is more efficient than packing in pellets. This last observation is of great value, since storing semen in straws is more appropriate due to sanitary reasons, and more convenient for ejaculates identification, especially for field application of genetic banks. / A adição de diluentes ao sêmen de aves é uma prática rotineiramente empregada em programas de inseminação artificial para melhorar o manejo de machos geneticamente superiores. A fertilidade do sêmen fresco normalmente decai 1 hora após a coleta, por isso a necessidade do uso de diluentes e temperaturas hipotérmicas para o armazenamento do sêmen por períodos mais prolongados. A Lipoproteína de Baixa Densidade (LDL), extraída da gema de ovo, tem sido utilizada na composição de diversos diluentes de sêmen para mamíferos, porém, ainda não tinha sido avaliada a sua aplicação em diluentes de resfriamento para sêmen de aves. Em relação ao congelamento, diversos métodos foram desenvolvidos ao longo dos anos. Uma das alternativas é o uso da Dimetilacetamida (DMA) como crioprotetor. Os melhores resultados obtidos com DMA ocorrem quando o sêmen é submetido ao congelamento ultra-rápido na forma de pellets e a um rápido descongelamento à 60ºC. O objetivo deste trabalho foi o estabelecimento de protocolos de preservação de sêmen de galos, enfocando o uso de Lipoproteínas de Baixa Densidade (LDL) como um componente do diluente para resfriamento, e a Dimetilacetamida (DMA) como crioprotetor interno para o congelamento. Para isto, foi verificado o efeito da adição de diferentes níveis de lipossomas de LDL na composição do diluente de resfriamento, sobre as características de qualidade do sêmen resfriado à 5 °C. Também foi avaliada a qualidade do sêmen congelado utilizando DMA como crioprotetor, envasado em palhetas ou pellets, e descongelados em três diferentes temperaturas. Os resultados obtidos nestes estudos nos permitiram concluir que: a adição de lipossomas de LDL ao diluente de resfriamento mantém a qualidade geral dos espermatozóides quando adicionado na proporção de 6%; sugerindo que melhorias na fertilidade podem ser obtidas desde que seja respeitado um limite de adição desta lipoproteína ao diluente; a temperatura corporal (40°C) foi a mais apropriada para descongelamento de sêmen criopreservado com DMA; e ainda, o envase em palhetas é mais eficiente em relação ao pellet. Esta última observação é de grande valor, visto que o armazenamento do sêmen em palhetas é mais adequado por razões sanitárias, e mais conveniente para a identificação dos ejaculados, especialmente para a aplicação a campo de bancos genéticos.
193

Long-term effects of the cholesterol level and its drug treatment

Hyttinen, L. (Laura) 06 December 2011 (has links)
Abstract Increased plasma cholesterol is a well-known risk factor for cardiovascular diseases in middle and early old age. At older ages, this association seems to disappear. Very few studies have assessed the impact of the lifelong cholesterol burden on old age, the purpose of this thesis. Study populations consisted of 1) old persons with familial hypercholesterolemia (FH), a genetic disorder associated with an increased risk of coronary heart disease (CHD) if untreated, and 2) initially healthy men (The Helsinki Businessmen Study, HBS) followed-up from midlife to old age. A population-based FH cohort, aged ≥ 65 years (n=37, aged 65 to 84 years) agreed to participate in this study. All but one of them had been using statin therapy for approx. 15 years. Variables studied were: health-related quality of life (HRQoL) with questionnaires (RAND-36, 15D), a brain magnetic resonance imaging (MRI) scan and cognitive tests (CERAD). These older FH patients enjoyed a similar HRQoL as controls in the general population. Only two (6%) of the older FH patients had clinically silent brain infarcts detected by MRI and those aged 65 to 74 years did not have more white matter hyperintensities (WMHIs) when compared to middle-aged controls. In the cognitive assessments, FH patients, especially those with duration of statin therapy longer than median, even expressed better episodic memory than population controls. HBS consists of a cohort of men (3277 men) who at baseline (1964–1973) were healthy and in their 40s. They were subdivided into seven groups according to baseline total cholesterol value at 1 mmol/L intervals starting from ≤  4 mmol/L. In 2000, at a mean age of 73 years, they filled a postal questionnaire including RAND-36. Cumulative mortality data were collected up to January 2010. A strong and graded relation was found between the cholesterol level and total mortality, those men with a cholesterol level ≤  4 mmol/L exhibiting the lowest mortality. A low cholesterol value at midlife also predicted a better score in the Physical functioning scale of RAND-36 in old age. In conclusion, in initially healthy men, a low cholesterol value at midlife was associated with better survival and better physical function in old age. Despite their genetic risk, FH patients on long-term statin medication seemed to enjoy a health and cognitive status similar to the general population. / Tiivistelmä Suurentunut plasman kolesterolipitoisuus on tunnettu valtimotautien riskitekijä keski-iässä, mutta vanhuusiässä kolesterolin merkitys näyttää vähentyvän. Hyvin harvassa tutkimuksessa on tutkittu elämänaikaisen kolesterolitason vaikutuksia vanhuusiän terveydentilaan, kuten tässä väitöskirjatyössä. Tutkimuskohteina olivat 1) iäkkäät, joilla on familiaalinen hyperkolesterolemia (FH) eli perinnöllinen sairaus, johon hoitamattomana liittyy lisääntynyt sepelvaltimotaudin riski, sekä 2) alun perin terveet miehet (Helsingin Johtajatutkimus), joita seurattiin keski-iästä vanhuuteen. Väestöpohjainen, 65 vuotta täyttänyt (65–84 vuotta, 37 henkilöä) FH-potilaiden ryhmä oli yhtä lukuun ottamatta käyttänyt keskimäärin 15 vuoden ajan statiinilääkitystä. Heille tehtiin seuraavat tutkimukset: terveyteen liittyvän elämänlaadun kyselyt (RAND-36- ja15D-mittarit), aivojen magneettitutkimus (MRI) ja kognitiota tutkivat testit (CERAD). FH-potilaiden elämänlaatu ei eronnut väestöverrokeista. Aivojen MRI tutkimuksessa vain kahdella (6 %) FH-potilaalla oli todettavissa kliinisesti hiljainen aivoinfarkti ja 65–74-vuotiailla FH-potilailla ei ollut enempää valkean aineen muutoksia kuin keski-ikäisillä verrokeilla. Kognitiotutkimuksissa FH-potilailla oli parempi episodinen muisti kuin väestöverrokeilla, etenkin niillä FH-potilailla, joiden statiinihoidon kesto oli mediaania pidempi. Helsingin Johtajatutkimukseen kuului alun perin 3 277 lähtötilanteessa (1964–1973) tervettä keski-ikäistä miestä. Heidät jaettiin lähtövaiheen kolesterolitason perusteella seitsemään ryhmään yhden millimoolin välein siten, että alin ryhmä oli alle 4 mmol/l. Vuonna 2000 (keski-ikä 73 vuotta) lähetettiin postikysely, johon kuului myös RAND-36. Kokonaiskuolleisuutta seurattiin tammikuuhun 2010 asti. Kokonaiskuolleisuuden ja keski-iän kokonaiskolesterolin välillä oli vahva ja asteittainen suhde siten, että niillä miehillä oli pienin kuolleisuus, joilla oli alin kolesteroli (alle 4 mmol/l). Pienin kolesterolipitoisuus keski-iässä oli myös yhteydessä RAND-36-mittarin Fyysinen toimintakyky -osion parempaan pistemäärään. Yhteenveto: Alun perin terveillä miehillä pieni kolesterolipitoisuus keski-iässä ennusti pitempää elämää ja myös parempaa fyysisistä toimintakykyä vanhalla iällä. Huolimatta perinnöllisestä riskistä oli pitkäaikaista statiinilääkitystä käyttäneiden FH-potilaiden terveydentila muuta väestöä vastaava.
194

Fibrinogenio, FVII, FVIII, FIX, FX e FXI como fatores de risco para tromboembolismo venoso em pacientes de uma população brasileira / Fibrinogen, FVII, FVIII, FIX, FX and FXI as risk factors for venous throembolism among patients of a Brazilian population

Mello, Tayana Bezerra Teixeira 07 May 2006 (has links)
Orientador: Joyce Maria Annichinno-Bizzacchi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-08T02:29:39Z (GMT). No. of bitstreams: 1 Mello_TayanaBezerraTeixeira_D.pdf: 2343820 bytes, checksum: be3d8e4b057cd84ec6771c67b8b1407d (MD5) Previous issue date: 2006 / Resumo: Nos últimos anos tem sido demonstrada uma associação entre níveis elevados de certos fatores da coagulação e risco de tromboembolismo venoso (TEV). Entretanto, o número de estudos é pequeno e a maioria estão restritos a populações caucasóides. Neste estudo caso-controle emparelhado por idade, sexo e etnia investigamos os níveis plasmáticos do fibrinogênio, FVII, FVIII, FIX, FX, FXI, FvW e grupo sanguíneo (GS) ABO no risco trombótico. Foram analisados 175 pacientes com TEV (122 mulheres e 53 homens), com idade mediana de 36 anos (13-63), acompanhados no Ambulatório de Hemostasia da Unicamp no período de julho de 2002 a julho de 2005. Na análise univariada, níveis elevados de FVIII (OR: 5,3 IC95% 2,9-9,6), FvW (OR: 4,9 IC95% 2,7-8,9), FIX (OR: 2,4 IC95% 1,3-4,4), FXI (OR: 2,1 IC95% 1,1-4,0) e GS não O (OR: 3,0 IC95% 1,9-4,6) foram fatores de risco para TEV. O FVIII, FvW e GS não O foram associados ao risco tanto em membro inferior como em sítio incomum da doença. A análise de todas estas variáveis, segundo critério de seleção ¿stepwise¿, mostrou o FVIII (OR: 3,1 IC95% 1,6-6,0), FvW (OR:2,8 IC95% 1,4-5,4) e o GS não-O (OR:2,2 IC95% 1,3-3,5) como fatores de risco independentes para TEV e que o FIX e FXI agiram sinergicamente a estas variáveis no acréscimo do risco trombótico. Risco de recorrência foi conferido por elevações do FIX (OR: 4,7 IC95% 1,8-11,9) e FXI (OR: 3,4 IC95% 1,8-8,7). Os determinantes dos níveis plasmáticos do FVIII não estão totalmente esclarecidos. Como a LRP (Low density lipoprotein receptor related protein) tem um papel no catabolismo do FVIII, foram pesquisados os polimorfimos C200T, o A775P e o D2080N no gene codificador dessa proteína, como fator de risco para TEV e a influência dos mesmos sobre os níveis do FVIII e FvW. Não houve diferença nas prevalências destes polimorfismos entre pacientes e controles. No entanto, no grupo-controle, o genótipo DN, do polimorfismo D2080N, foi associado a menores concentrações do FVIII (77,4 UI/dl) e FvW (70,2 UI/dl), quando comparado ao genótipo DD (127 UI/dl e 108,4 UI/dl, respectivamente p<0,05). Em conclusão, nesta população brasileira miscigenada, o FVIII, FvW , FIX, FXI e GS não O foram associados ao risco de TEV e o polimorfismo D2080N, no gene da LRP, interferiu com os níveis plasmáticos de FVIII e FvW / Abstract: During the last years an association between high levels of certain coagulation factors and the risk for venous thromboembolism (VTE) has been demonstrated. The number of studies, however, is small, and most of them are restricted to Caucasian populations. In this case control study, matched for age, sex and ethnicity, we investigated the plasma levels of fibrinogen, FVII, FVIII, FIX, FX, FXI, vWF and the ABO blood group (BG) in the thrombotic risk. It was analyzed 175 patients with VTE (122 women and 53 men), median age 36 years (13-63), followed at the hemostasis outpatient clinic at the State University of Campinas ¿ UNICAMP, between July 2002 and July 2005. In univariate analysis, elevated levels of FVIII (OR: 5.3 95%CI 2.9-9.6), FvW (OR: 4.9 95%CI 2.7-8.9), FIX (OR: 2.4 95%CI 1.3-4.4), FXI (OR: 2.1 95%CI 1.1-4.0) and non O BG (OR: 3.0 95%CI 1.9-4.6) were risk factors for VTE. FVIII, FvW and non O BG were associated with the risk both in lower limbs and unusual sites of disease. Analysis of all these variables by stepwise selection criteria showed FVIII (OR:3.1 95%CI 1.6-6.0), FvW (OR:2.8 95%CI 1.4-5.4) and non O BG (OR:2.2 95%CI 1.3-3.5) as independent risk factors for VTE, and FIX and FXI increased synergistically the risk of thrombosis of these variables. Risk of recurrence was conferred by FIX (OR:4.7 IC95% 1.8-11.9) and FXI (OR:3.4 IC95% 1.8-8.7). The FVIII plasma levels determinants are not well established. Since LRP (Low density lipoprotein receptor related protein) has a role in the catabolism of FVIII, we evaluated the C200T, A775P and, D2080N polymorphisms in the gene coding of this protein, as risk factor for VTE and their influence upon the levels of FVIII and vWF. There was no difference regarding the prevalence of these polymorphisms between patients and controls. However, in the control group, the DN genotype, of the D2080N polymorphism, was associated with lower concentrations of FVIII (77.4 UI/dl) and vWF (70.2 UI/dl), when compared to DD genotype (127 UI/dl e 108.4 UI/dl, respectively p<0.05). In conclusion, in these Brazilian miscigenous population, increased levels of FVIII, FvW, FIX, FXI and non O BG were associated with VTE risk and the D2080N polymorphism, in the LRP gene, influenced plasma levels of FVIII and vWF / Doutorado / Biologia Estrutural, Celular, Molecular e do Desenvolvimento / Doutor em Fisiopatologia Medica
195

Os efeitos do exercício resistido no metabolismo da lipoproteína de baixa densidade (LDL) e da lipoproteína de alta densidade (HDL), utilizando uma nanoemulsão semelhante a LDL / Effects of resistance exercise on the low density lipoprotein (LDL) and high density lipoprotein (HDL) metabolism: utilizing an LDLlike nanoemulsion

Jeferson Luis da Silva 12 September 2011 (has links)
Treinamento físico é considerado um dos principais instrumentos para promover um estilo de vida saudável. No entanto, os efeitos do treinamento resistido sobre as vias metabólicas, especialmente o metabolismo lipídico intravascular é em grande parte inexplorada e merece uma investigação mais aprofundada. No presente estudo nós avaliamos os efeitos do treinamento resistido sobre o metabolismo de uma nanoemulsão artificial lipídica e na transferência de lípides para HDL, uma importante etapa do metabolismo da HDL. A cinética plasmática da nanoemulsão artificial lipídica foi estudada em 15 homens saudáveis com treinamento resistido regular de 1-4 anos (idade = 25 ± 5 anos, VO2máx = 50 ± 6 mL/kg/min) e em 15 homens saudáveis sedentários (28 ± 7 anos, VO2máx = 35 ± 9 mL/kg/min). A nanoemulsão artificial lipídica marcada com éster de colesterol-14C e colesterol livre-3H foi injetada por via intravenosa, as amostras de plasma foram coletadas por 24 h para determinar curvas de cinéticas e a taxa fracional de remoção (TFR). Transferência de lípides para HDL foi determinada in vitro pela incubação de amostras de plasma com nanoemulsões (doadores de lípides) marcada com o isótopo radioativo colesterol livre, éster de colesterol, triglicérides e fosfolípides. Tamanho da HDL, atividade da paraoxonase 1 e os níveis de LDL oxidada também foram determinadas. Os dois grupos apresentaram LDL-colesterol, HDL-colesterol e triglicérides semelhantes, mas a LDL oxidada foi menor no grupo treinamento resistido (30 ± 9 vs 61 ± 19 U/L, p = 0,0005). No treinamento resistido, a nanoemulsão éster de colesterol-14C foi removida duas vezes mais rápido do que em indivíduos sedentários (TFR: 0,068 ± 0,023 vs 0,037 ± 0,028, p = 0,002), bem como o colesterol livre-3H (0,041 ± 0,025 vs 0,022 ± 0,023, p = 0,04). Embora ambos os componentes da nanoemulsão tenham sido removidos na mesma proporção em indivíduos sedentários, no grupo treinamento resistido o colesterol livre-3H foi removido mais lento do que o éster de colesterol-14C (p = 0,005). Tamanho da HDL, paraoxonase 1 e as taxas de transferência de HDL dos quatro lipídios foram as mesmas em ambos os grupos. Portanto, concluímos que o treinamento resistido acelera a remoção da nanoemulsão artificial lipídica, o que provavelmente explica a redução dos níveis de LDL oxidada no grupo treinamento resistido. O treinamento resistido também alterou o equilíbrio da TFR do colesterol livre e esterificado. No entanto, o treinamento resistido não teve efeito nos parâmetros relacionados ao metabolismo da HDL / Exercise training is considered one of the main instruments to promote a healthy lifestyle. However, effects resistance training on the metabolic pathways, specially the intravascular lipid metabolism is largely unexplored and deserves further investigation. In this study we evaluated the effects of resistance training on the metabolism of an LDL-like nanoemulsion and on lipid transfer to HDL, an important step of HDL metabolism. LDL-like nanoemulsion plasma kinetics was studied in 15 healthy men under regular resistance training for 1-4 years (age = 25 ± 5 years, VO2peak = 50 ± 6 mL/kg/min) and in 15 healthy sedentary men (28 ± 7 years, VO2peak = 35 ± 9 mL/kg/min). LDL-like nanoemulsion labeled with 14C-cholesteryl ester and 3H-free cholesterol was injected intravenously, plasma samples were collected over 24 h to determine kinetics curves and fractional clearance rates (FCR). Lipid transfer to HDL was determined in vitro by incubating of plasma samples with nanoemulsions (lipid donors) labeled with radioactive free cholesterol, cholesteryl ester, triglycerides and phospholipids. HDL size, paraoxonase 1 activity and oxidized LDL levels were also determined. The two groups showed similar LDL and HDL-cholesterol and triglycerides, but oxidized LDL was lower in resistance training group (30 ± 9 vs 61 ± 19 U/L, p = 0.0005). In resistance training, the nanoemulsion 14Ccholesteryl ester was removed twice as fast than in sedentary individuals (FCR: 0.068 ± 0.023 vs 0.037 ± 0.028, p = 0.002), as well as 3H-free cholesterol (0.041 ± 0.025 vs 0.022 ± 0.023, p = 0.04). While both nanoemulsion labels were removed at the same rate in sedentary individuals, in resistance training group 3H-free cholesterol was removed slower than 14C-cholesteryl ester (p = 0.005). HDL size, paraoxonase 1 and the transfer rates to HDL of the four lipids were the same in both groups. Therefore, we conclude that the resistance training accelerated the clearance of LDL-like nanoemulsion, which probably accounts for the oxidized LDL levels reduction in resistance training group. Resistance training also changed the balance of free and esterified cholesterol FCRs. However, RT had no effect on HDL metabolism related parameters
196

Efeito da dieta tipo Mediterrânea na função endotelial e inflamação da aterosclerose: estudo comparativo com a dieta TLC (\"Therapeutic Lifestyle Changes\", no NCEP-ATPIII) / Effects of Mediterranean diet on endothelial function an inflammation in atherosclerosis: a comparative study with Therapeutic Lifestyle Changes Diet (TLCD) do National Cholesterol Education Program-ATPIII

Maria Cristina Dias Thomazella 01 June 2010 (has links)
A dieta Mediterrânea (DM) tem sido amplamente estudada do ponto de vista epidemiológico porém, o efeito pleno específico da DM, bem como os mecanismos pelos quais esse padrão dietético contribui para redução do risco cardiovascular em prevenção secundária, são desconhecidos. Isso ocorre, em parte, devido à dificuldade de aderência observada em ensaios clínicos de intervenção dietética, especialmente estudos comparativos com dietas hipolipemiantes, por exemplo, a dieta TLC, Therapeutic Lifestyle Changes Diet (TLCD) do National Cholesterol Education Program-ATPIII. Assim, realizamos um estudo clínico, controlado, não randomizado, comparando o perfil de risco cardiovascular de dieta Mediterrânea (DM) versus dieta TLC (DTLC) em 40 pacientes com doença arterial coronariana, homogeneamente selecionados (45-65 anos de idade, homens, que tiveram ao menos um evento coronariano nos 2 últimos anos) e intensamente medicados. Uma questão paralela foi entender os efeitos de ambas as dietas nos processos de inflamação, disfunção endotelial e do estresse oxidativo, fatores-chave na aterogênese e particularmente importantes na prevenção secundária. Os hábitos culturais e dietéticos foram relevantes para alocação dos pacientes nos grupos de dieta Mediterrânea (n = 21; dieta rica em grãos integrais, vegetais, frutas, oleaginosas 10 g/dia, azeite de oliva extra-virgem 30 g/dia e vinho tinto 250 ml/dia) ou dieta TLC (n = 19; suplementada com fitosteróis 2g/dia através de creme vegetal 20 g/dia). Escores de aderência validados na literatura e específicos às dietas mostraram resultado > 90% no índice de aderência aos dois padrões dietéticos. Alguns efeitos foram comuns à dieta Mediterrânea e à dieta TLC. Com ambas, houve redução significativa de peso, índice de massa corporal (kg/m²), variáveis de composição corporal e pressão arterial. Além disso, ambas as dietas promoveram redução dos níveis plasmáticos de ADMA e da relação L-arginina/ADMA. A reatividade da artéria braquial dependente do endotélio permaneceu inalterada em ambos os grupos; no entanto, pacientes sob DM e sob DTLC melhoraram a velocidade de fluxo no momento basal (pré-hiperemia vascular). Outros efeitos foram específicos a cada padrão dietético. Com a DM, foram observados diminuição na contagem total de leucócitos versus DTLC (p =0.025) e aumento nos níveis de HDL-colesterol em 3 mg/dL (p = 0.053) versus DTLC, que mantiveram níveis de HDL-C inalterados. O diâmetro basal da artéria braquial aumentou com a DM, mas não com a DTLC. Com a DTLC, houve redução estatisticamente significante versus DM nas variáveis lipídicas colesterol total, LDL-colesterol (p < 0.05) e LDL oxidada (p = 0.009), embora a razão LDL oxidada/LDL total não tenha se alterado. Níveis séricos/plasmáticos de apolipoproteína A-1, lipoproteína(a), glicose, mieloperoxidase, sICAM, sVCAM, e as razões glutationa reduzida/oxidada em plasma e eritrócitos não se alteraram em ambos os grupos. Em conjunto, estes dados indicam um perfil de efeitos da DM e DTLC compatíveis com redução do risco cardiovascular, mesmo em pacientes intensamente medicados, em prevenção secundária. Embora estes efeitos tenham sido equivalentes entre DM e DTLC, eles parecem ser mediados tanto por alguns mecanismos comuns, como alguns mecanismos específicos de cada dieta / The Mediterranean Diet (MD) has been widely studied with respect to epidemiology, but mechanisms whereby the Mediterranean Diet (MD) is cardioprotective are unclear. This is partly because of the difficulties of adherence in clinical trials of dietary intervention, particularly trials comparing it to traditional lipid-restraining diets, e.g., Therapeutic Lifestyle Changes Diet (TLCD) from National Cholesterol Education Program ATPIII. We performed a controlled, non-randomized clinical trial comparing the cardiovascular risk profile of the Mediterranean Diet (MD) versus the TLC Diet (TLCD) in 40 selected, highly-homogeneous, and intensively medicated patients with coronary heart disease (45-65 years, males, at least one coronary event over prior 2 years). In addition, we sought to investigate both diets effects on inflammation, endothelial dysfunction and oxidative stress, all key factors in atherogenesis and particularly important in secondary prevention. Dietary/cultural habits were the basis to allocate patients for 3 months to either MD (n = 21; rich in whole grains, vegetables, fruits, nuts 10g/day, extra-virgin olive oil 30g/day, red wine 250ml/day) or TLCD (n = 19; plus phytosterols 2g/day). Specific scores showed that both diets had >90% adherence. Some effects were common to both diets. Patients in both groups showed a significant reduction in weight, body mass index, body composition and blood pressure. Also, both groups presented a reduction in plasma levels of ADMA and L-arginine/ADMA ratio. Endothelial-dependent brachial artery reactivity remained unaltered in both groups. However, patients under MD and TLCD improved flow velocity at baseline (prior to hyperemia). Nevertheless, other effects were specific to each diet. With MD, there was significant decrease in leukocyte count vs. TLCD (p = 0.03) and average increase in HDL-cholesterol by 3 mg/dL (p = 0.053) versus TLCD. The brachial arterials basal diameter increased with MD but not with TLCD. However, with TLCD there was a statistically significant reduction of lipid variables: total cholesterol, LDL-cholesterol (p < 0.05) and oxidized LDL (p = 0.009) vs. MD even though the ratio of oxidized / total LDL remained unaltered. Plasma and serum levels of apolipoprotein A-1, lipoprotein(a), glucose, myeloperoxidase, sICAM, sVCAM, and glutathione reduced/oxidized ratio in plasma and erithrocytes also remained unaltered in both groups. Together, these results demonstrate a pattern of effects of MD and TLCD compatible with cardiovascular risk reduction, in secondary prevention, even in intensely medicated patients. Although these effects were equivalent between MD and TLCD, they seem to be mediated by some common mechanisms, as well as by each diets specific mechanisms
197

Der interzelluläre Transport Lipid-geladener Lysosomen aus Makrophagen in glatte Gefäßmuskelzellen führt zur phänotypischen Veränderung der Gefäßmuskelzellen in einen schaumzellartigen Phänotyp

Weinert, Sönke 27 June 2014 (has links)
AIMS: Macrophages (MPs) and vascular smooth muscle cells (VSMCs) closely interact within the growing atherosclerotic plaque. An in vitro co-culture model was established to study how MPs modulate VSMC behaviour. METHODS AND RESULTS: MPs were exposed to fluorescence-labelled-acetylated LDL (FL-acLDL) prior to co-culture with VSMCs. Fluorescence microscopy visualized first transport of FL-acLDL within 6 h after co-culture implementation. When MPs had been fed with FL-acLDL in complex with fluorescence-labelled cholesterol (FL-Chol), these complexes were also transferred during co-culture and resulted in cholesterol positive lipid droplet formation in VSMCs. When infected with a virus coding for a fusion protein of Rab5a and fluorescent protein reporter (FP) to mark early endosomes, no co-localization between Rab5a-FP and the transported FL-acLDL within VSMCs was detected implying a mechanism independent of phagocytosis. Next, expression of lysosome-associated membrane glycoprotein 1 (LAMP1)-FP, marking all lysosomes in VSMCs, revealed that the FL-acLDL was located in non-acidic lysosomes. MPs infected with virus encoding for LAMP1-FP prior to co-culture demonstrated that intact fluorescence-marked lysosomes were transported into the VSMC, instead. Xenogenic cell composition (rat VSMC, human MP) and subsequent quantitative RT-PCR with rat-specific primers rendered induction of genes typical for MPs and down-regulation of the cholesterol sensitive HMG-CoA reductase. CONCLUSION: Our results demonstrate that acLDL/cholesterol-loaded lysosomes are transported from MPs into VSMCs in vitro. Lysosomal transfer results in a phenotypic alteration of the VSMC towards a foam cell-like cell. This way VSMCs may lose their plaque stabilizing properties and rather contribute to plaque destabilization and rupture.
198

Kopplungsuntersuchungen zur Identifizierung Atherosklerose assoziierter Genorte und Atherosklerose- modifizierender Faktoren in LDL-Rezeptor defizienten BALB/c und C57BL/6 Mäusen: Publikationsdissertation zur Erlangung des akademischen Grades Dr. med.an der Medizinischen Fakultätder Universität Leipzig

Sündermann, Simon 17 July 2012 (has links)
Atherosklerotisch bedingte Herz-Kreislauferkrankungen zählen weltweit zu den häufigsten Todesursachen. Die vorliegende Arbeit befasst sich in einem Mausmodell mit der Identifikation neuer Genorte, welche die Ausprägung der Atherosklerose und deren Kofaktoren beeinflussen. Zu diesem Zweck wurde eine Kopplungsuntersuchung in einer Kreuzung Atherosklerose-empfindlicher C57BL/6 und BALB/c Mäuse auf dem LDL-Rezeptor defizienten Hintergrund durchgeführt. Außer der Größe der atherosklerotischen Läsionen wurden 61 weitere Phänotypen bestimmt. Als Hauptergebnis konnte ein neuer Genlocus auf dem proximalen Chromosom 2 identifiziert werden, welcher einen Einfluss auf die Größe der atherosklerotischen Läsionen an der Aortenwurzel hat. Des Weiteren zeigte sich eine Co-Segregation von Lipoproteinen (Very-Low-Density Lipoprotein (VLDL) Cholesterin und High-Density Lipoprotein (HDL) Cholesterin mit diesem Locus sowie eine Korrelation dieser Lipide mit der Läsionsgrösse. Diese Ergebnisse deuten darauf hin, dass der Effekt des Chromosom 2 Lokus auf die Atherosklerose durch genetische Faktoren des Fettstoffwechsels bedingt ist. Weitere Experimente sind notwendig um den QTL weiter einzuengen und die verantwortlichen Gene zu identifizieren.
199

Proatherosklerotische Wechselwirkung von oxidativem Stress, Low-Density-Lipoprotein, Angiotensin II und Endothelin-1 in humanen Endothelzellen

Catar, Rusan Ali 20 July 2007 (has links)
Eine der häufigsten kardiovaskulären Erkrankungen ist die Atherosklerose. Bei der Entstehung einer Atherosklerose spielt eine Hyperlipoproteinämie eine entscheidende Rolle. Ein weiterer Faktor für die Entstehung kardiovaskulärer Erkrankungen ist ein hoher Blutdruck. In dieser Arbeit wurde eine mögliche Interaktion zwischen Lipoproteinen und den blutdruckregulierenden Endothelin- und Renin-Angiotensin-Systemen untersucht. Weiterführende Analysen erfolgten an Rezeptoren für die Aufnahme von nLDL und oxLDL. Abschließend wurden Signalwege untersucht, die durch nLDL und oxLDL aktiviert werden. Tierexperimentielle Untersuchungen in Aorten und Herzen fettreich gefütterter Wildtyp- Mäuse unterstützen die Zellkultur-Ergebnisse einer Induzierung des Endothelin-Systems durch erhöhte Lipoproteine. Zusammenfassend zeigt diese Arbeit neue Mechanismen der Interaktion von Lipoproteinen und blutdruckregulierenden Systemen in Endothelzellen. Die Rezeptoren scheinen dabei eine Schlüsselrolle zu spielen. Dies spricht für eine Potenzierung von Hyperlipoproteinämie und Hypertonie bei der Entstehung von Herz-Kreislauf-Erkrankungen.
200

THERAPEUTIC MECHANISMS OF INTERLEUKIN-19 FOR VASCULAR PROLIFERATIVE DISEASES

Cuneo, Anthony January 2012 (has links)
Cardiovascular disease is the leading cause of mortality in the western world. The pro-inflammatory and pro-proliferative etiology of vascular proliferative diseases is well characterized, while much less is known about the mechanisms of anti-inflammatory and anti-proliferative processes. Interleukin-19 (IL-19) is a newly described member of the IL-10 family of anti-inflammatory interleukins, and our group was the first to discover IL-19 expression in activated, synthetic, but not quiescent, contractile human vascular smooth muscle cells (hVSMC). We also found that IL-19 is anti-inflammatory and anti-proliferative for hVSMC. IL-19 is able to reduce the abundance of COX-2, IL-1&beta;, IL-8, and Cyclin D1 transcripts which contain AU-rich elements (ARE) in their 3'-untranslated regions (3'-UTR). IL-19 is able to reduce the abundance of HuR, a stabilizing RNA-binding protein, which we feel provides a mechanism for these effects. The overall goal of this study is to elucidate IL-19's anti-inflammatory and anti-proliferative mechanism(s) in hVSMC in the context of vascular proliferative diseases. This goal has directed our overall hypothesis: IL-19's anti-proliferative and anti-inflammatory effects in hVSMC are mediated, at least in part, by modulation of HuR abundance and translocation, resulting in decreased stability of mRNA transcripts. HuR functions through a translocation mechanism, and IL-19 is able to reduce HuR cytoplasmic abundance. IL-19 also reduces HuR phosphorylation, which is a pre-requisite for HuR translocation, possibly through a PKC&alpha;-dependent mechanism. The stability of ARE-containing transcripts is reduced with IL-19 treatment, and reducing HuR expression by siRNA has the same inhibitory effect. VSMC are important mediators in the initiation of atherosclerosis. Oxidized low-density lipoprotein (ox-LDL) is able to induce IL-19 expression in these cells. VSMC are known to express scavenger receptors that take up ox-LDL. IL-19 is able to reduce the uptake of ox-LDL and the abundance of ox-LDL induced LOX-1 and CX-CL16 scavenger receptors. Interestingly, these scavenger receptors also have ARE in their 3'-UTR. IL-19 is able to reduce ox-LDL induced HuR cytoplasmic abundance. HuR knockdown by siRNA reduces the uptake of ox-LDL by hVSMC. These data suggest that IL-19 reduced scavenger receptor abundance may be due to decreased total and cytoplasmic HuR abundance. IL-19 reduces the abundance of ox-LDL induced COX-2 expression. Taken together, these results demonstrate that IL-19 down-regulates vital steps in vascular proliferative disease processes through an HuR-dependent mechanism. / Molecular and Cellular Physiology

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