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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.
151

Comparação entre a atividade da proteína de transferência de colesterol esterificado e o tamanho da HDL na associação com a aterosclerose carotídea / Comparison between cholesteryl ester transfer protein and HDL size in association with carotid atherosclerosis

Parra, Eliane Soler, 1981- 25 August 2018 (has links)
Orientadores: Andrei Carvalho Sposito, Eliana Cotta de Faria / Texto em português e inglês / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T06:33:21Z (GMT). No. of bitstreams: 1 Parra_ElianeSoler_D.pdf: 3645332 bytes, checksum: 085ab65e147faa7a1f1684591c22e6d8 (MD5) Previous issue date: 2014 / Resumo: A lipoproteína de alta densidade (HDL) é um complexo heterogêneo e versátil de partículas com variações funcionais resultantes da integração de uma vasta gama de componentes, como apolipoproteínas, receptores, transportadores, enzimas e fosfolípides, com ações indiretas ou diretas sobre o seu metabolismo. Além disso, as concentrações plasmáticas do colesterol da HDL (HDL-C) e seu tamanho representam importantes fatores inversos ao desenvolvimento de doenças cardiovasculares, particularmente em indivíduos em prevenção primária. A proteína de transferência de colesterol esterificado (CETP) desempenha uma função importante no transporte reverso do colesterol (TRC) que é umas das principais funções antiaterogênicas da HDL. No entanto, a atividade da CETP é inversamente associada às concentrações de HDL-C e ao tamanho da partícula. Adicionalmente, HDL grande demonstra ser mais efetiva no efluxo do colesterol, parte integrante do TRC, comparada à partícula de HDL menor. Nesse contexto, o objetivo do estudo foi avaliar, em indivíduos livres de doença aterosclerótica manisfesta, a associação entre o tamanho da HDL e a redução da atividade da CETP induzida geneticamente com a carga aterosclerótica carotídea. Utilizamos para esse fim dois polimorfismos da CETP, TaqIB e I405V, que foram bem caracterizados funcionalmente e encontrados frequentemente na população. Assim, os objetivos desta tese foram: (i) investigar se a presença dos polimorfismos TaqIB e I405V do gene da CETP está associada às concentrações de HDL-C e à aterosclerose carotídea subclínica (n=207); (ii) pesquisar se, além das concentrações de HDL-C, o tamanho da partícula de HDL está associado à aterosclerose subclínica (n=284). Para estes estudos foram determinados os perfis lipídicos, lipoproteícos e apoproteícos, proteína C-reativa (PCR), anticorpos anti-LDL oxidada, atividades das proteínas CETP e de transferência de fosfolípides (PLTP), HDL2 e HDL3 e o diâmetro da HDL. Os polimorfismos TaqIB e I405V da CETP também foram detectados. A espessura da camada íntima-medial da artéria carótida comum (EIMc) foi mensurada por ultrassonografia. Na presença do menor alelo dos polimorfismos TaqIB e I405V da CETP, EIMc correlacionou-se inversamente com atividade da CETP e positivamente com atividade da PLTP e anticorpos anti-LDL oxidada. Na análise multivariada, a presença do menor alelo do polimorfismo TaqIB, mas não do I405V, foi associado a um aumento de 5,1 vezes de risco de maior EIMc. No entanto, a atividade da CETP não diferiu entre os grupos de presença e ausência do menor alelo do polimorfismo TaqIB. Com relação ao tamanho das partículas, HDL maiores foram associadas a menores EIMc e foram melhores indicadores de risco de aterosclerose carotídea subclínica comparadas às concentrações de HDL-C. Em conclusão, o aumento do tamanho da HDL tem associação independente com a carga aterosclerótica e, embora o polimorfismo TaqIB também se associe, sua interação parece ser independente da atividade da CETP / Abstract: High-density lipoproteins ( HDL ) are a group of heterogeneous and complex particles with versatile functional changes resulting from the integration of a wide range of components, such as apolipoproteins, receptors, transporters, enzymes and phospholipids with indirect or direct actions on your metabolism. In addition, plasma concentrations of HDL cholesterol (HDL -C) and its size are inversely related to the development of cardiovascular diseases, particularly in primary prevention in individuals. The cholesterol ester transfer protein (CETP) plays an important role in reverse cholesterol transport (RCT), which is one of the main functions of HDL. However, CETP activity is inversely related to HDL-C and particle size. Additionally, largest HDL particles have demonstrated a higher cholesterol efflux capacity. In this context, the aim of the study was to evaluate, in individuals free of manifest atherosclerotic disease, the association between the size of HDL and CETP activity genetically induced with carotid atherosclerosis burden. We used for this purpose, two polymorphisms of CETP TaqIB and I405V, which have been well characterized functionally and often found in the population. The objectives of this thesis were: (i) to investigate whether the presence of polymorphisms I405V and TaqIB of CETP gene is associated with HDL-C and subclinical carotid atherosclerosis (n= 207); (ii) to investigate if, in addition to HDL-C, the particle size of HDL is associated with atherosclerosis (n= 284). We determined lipid, lipoprotein profiles and apolipoprotein, C-reactive protein (CRP), antibodies against oxidized LDL, CETP and phospholipid transfer protein (PLTP) activities, HDL2 and HDL3 and HDL size. The TaqIB and I405V CETP polymorphisms were also analyzed. Common carotid artery intima-media thickness (cIMT) was measured using ultrasonography. In the presence of the minor alleles of the TaqIB and I405V polymorphisms of CETP, cIMT was inversely correlated with CETP activity and positively with PLTP activity and antibodies against oxidized LDL. In multivariate analysis, the presence of the minor allele of the TaqIB polymorphism, but not the I405V, was associated with a 5.1 times increased risk of higher cIMT. However, CETP activity did not differ between the presence and absence of minor allele groups of the TaqIB polymorphism. Regarding HDL size, increased HDL size was associated with lower cIMT and was better marker of risk of subclinical carotid atherosclerosis compared to HDL-C. In conclusion, increased size of HDL is independently associated with atherosclerotic and, although TaqIB polymorphism is also associated, its interaction seems to be independent of CETP activity / Doutorado / Clinica Medica / Doutora em Clínica Médica
152

Capacidade da Lipoproteína de Alta Densidade (HDL) de receber lipídeos em diferentes faixas etárias: um estudo in vitro utilizando uma lipoproteína artificial / Capacity of the High Density Lipoprotein (HDL) to receive lipids in different age: a study in vitro using an artificial nanoemulsion

Carolina Heitmann Mares Azevedo 26 September 2007 (has links)
A relação entre transferência de lipídeos, idade e aterogênese são complexas e ainda não estão claras. É possível que a troca de lipídeos esteja alterada com a avançar da idade e relacionada com a Doença Arterial Coronariana (DAC). O objetivo deste trabalho foi verificar a hipótese se em indivíduos mais jovens a habilidade da HDL de receber lipídeos é diferente de indivíduos mais velhos com e sem a evidência clínica da DAC. Dentro desses aspectos, foram determinados o diâmetro da partícula desta lipoproteína, a atividade da Paraoxonase (PON1) e sua capacidade de receber lipídeos. Para tanto, foram estudados 86 indivíduos divididos em quatro grupos: adulto jovem (25±4), meia-idade (42±8), idosos sem evidência clínica de DAC (75±6) e idosos com DAC (74±5). Uma nanoemulsão artificial rica em colesterol (LDE) marcada com 3H-TG e 14C-CL ou 3H-CE e 14C-FL foi incubada com plasma. Após a precipitação de outras lipoproteínas, o sobrenadante contendo HDL foi separado e em seguida, medida a radioatividade. O diâmetro da HDL foi medido por laser scattering (nm). Foram constatadas diferenças significativas entre as taxas de transferência de 3H-éster de colesterol (CE) entre os grupos: adulto jovem (3.7±1.0%); meia idade (4.1 ±0.7%) e idosos (5.3±1.8%);p= 0.024. Também ocorreu diferença entre as taxas de transferência do 14C-fosfolipídeo (FL): adulto jovem (18.7±4.6%), meia idade (18.3 ±4.0%) e idosos (20.6±5.3); p=0.0368. Com relação ao tamanho das partículas de HDL, foi encontrada diferença entre os grupos: os grupos adulto jovem (8.9± 0.3nm) e meia idade (8.9± 0.3nm) apresentaram menores diâmetros de HDL quando comparados ao do grupo de idosos sem evidência clínica da DAC (9.7± 1.6);p= 0,0444. As transferências de lipídeos foram expressas em % de radioatividade. A idade correlacionou-se positivamente com a taxa de transferência do 3H- éster de colesterol (r=0.3365; p=0.0036), com a concentração de colesterol total (r=0.4965; p=0.0001) e com a concentração de HDL colesterol (r=0.3559; p=0.0023). Também houve correlação positiva com o tamanho de HDL (r=0.3695; p=0.0013). Em princípio, os indivíduos idosos sem evidência clínica da DAC, aparentemente têm alguma proteção contra a mesma. Desse modo, com o intuito de saber se os resultados encontrados no presente trabalho sustentam a afirmação acima, foi realizada a comparação desse grupo com um grupo de idosos que apresentavam a DAC. O grupo com DAC apresentou menor tamanho de partícula de HDL (8,7±0,7). As taxas de transferência de 3H-CE e de 14C-FL também foram menores neste grupo (3H-CE=3,1 ±2,3 e 3H-TG= 5,1 ±1 ,6). Devido ao importante papel antiaterogênico da HDL, esses resultados podem ser relevantes para estabelecer novos mecanismos existentes entre os aspectos qualitativos dessa lipoproteína, o avanço da idade e a presença da DAC. / The relationship between transfer of lipids, age and atherogenesis are complex and yet unclear and is possible that the shift of lipids to HDL may be altered by the aging process and related with coronary artery disease (CAD). We tested the hypothesis whether in younger patients the ability of HDL to receive lipids is different from that of elderly patients with or without CAD. Inside of these aspects, the HDL size, the activity of Paraoxonase (PON1) and its capacity to receive lipids was determined. It was studied, 25 younger, 25 middle age, 36 elderly patients with a coronariography and/or a perfusion scintilography on the last 6 months (11 with CAD, 74±5 yo; and 25 patients without proved CAD, 75±6 yo). An artificial cholesterol-rich nanoemulsion labeled with 3H-TG and 14C-FC or H-CE and 14C-PL was incubated, per 1 hour, with plasma. After chemical precipitation of apoB-containing lipoproteins and the nanoemulsion, the supernatant containing HDL was counted for radioactivity. The HDL diameter was measured by laser-light-scattering. Transfer of CE and PL to HDL was smaller in young patients than in the elderly patients without CAD, but the transfer of the other lipids are equal (CE: young= 3.7±1.0%; middle age= 4.1 ±0.7%; elderly without CAD= 5.3±1.8%; p= 0.024 and PL: young= 18.7±4.6%; middle age= 18.3 ±4.0%; elderly without CAD= 20.6±5.3; p=0.0368). The HDL size was greater in elderly group without CAD (9.7± 1.6nm) than in younger (8.9± 0.3nm) and middle age patients (8.9± 0.3nm); p=0,0444. Transfer of lipids to HDL was expressed as % of total incubated radioactivity. The age positively correlated with the transfer of CE (r=0.3365; p=0.0036), with the total cholesterol concentration (r=0.4965; p=0.0001) and with the HDL concentration cholesterol (r=0.3559; p=0.0023). Also had positive correlation with the size of HDL (; p=0.0013). In principle, the aged patients without CAD, have some protection against the same one. In this aspect, with intention to know if the results found in the present work support the affirmation above, was compared this group with a group of aged that presented the CAD. Comparing elderly patients without CAD with elderly patients with CAD, the transfer of CE and FL as well as HDL size was smaller in the CAD group (CE=3.1±2.3 and TG= 5.1±1.6; 8.7±0.7nm). Due to HDL important antiatherogenic roles, this result can be relevant to establish new mechanisms and risk factors in aging and in CAD.
153

Association between periodontal and systemic inflammation:a study of pro- and anti-inflammatory mediators

Norppa, A. (Anna) 12 November 2012 (has links)
Abstract The principal aim of this study was to explore associations between systemic inflammatory status and periodontal inflammation and tissue destruction. The study population consisted of 61 patients with chronic periodontitis, 30 periodontally healthy control subjects, and 80 subjects with type 1 diabetes mellitus (T1DM). The T1DM subjects were periodontally treated and re-examined eight weeks after completion of the treatment. The periodontal measures included plaque, probing depth (PD), bleeding on probing (BOP) and attachment level (AL). The serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interleukin (IL)-10, as well as the gingival crevicular fluid (GCF) level of matrix metalloproteinase (MMP)-8 were analyzed using commercially available ELISA assays, and serum high density lipoprotein (HDL) level using direct enzymatic methods. Serum IL-6 level associated significantly with the extent of inflamed periodontal pockets in T1DM subjects. Moreover, serum IL-6 modulated local periodontal inflammation in T1DM patients; periodontal healing turned out to be poorer in subjects with a high level of serum IL-6 than in those with a low level. Serum TNF-α/IL-10 ratio was three times higher in chronic periodontitis patients than in periodontally healthy control subjects. In T1DM subjects a significant inverse association between serum HDL level and the extent of inflamed periodontal pockets was found; subjects with a low serum HDL level presented 50% more inflamed periodontal sites than subjects with a high serum HDL level. A significant association between GCF MMP-8 level in shallow crevices and the extent of periodontal attachment loss in chronic periodontitis patients was observed. In conclusion, we focused on analyzing associations between systemic inflammatory status and periodontal conditions. According to our results, periodontal inflammation/infection is associated with systemic inflammatory status using serum IL-6, TNF-α/IL-10 ratio and HDL as indicators. Also, a high level of MMP-8 in GCF in shallow crevices could be indicative of higher susceptibility to periodontal infection and tissue destruction. / Tiivistelmä Tutkimuksen tavoitteena oli tarkastella hampaiden kiinnityskudosten tulehduksen (pardodontiitti) ja siihen liittyvän inflammaation yhteyttä systeemiseen tulehdustilaan. Tutkimusaineistoon kuului 61 yleistervettä potilasta, joilla oli kohtalaisesti tai pitkälle edennyt parodontiitti, 30 yleistervettä yksilöä, joiden hampaiden kiinnityskudokset olivat terveet/lähes terveet (kontrolliryhmä), sekä 80 tyypin 1 diabetes mellitus (T1DM) potilasta, joilla esiintyi vaihtelevasti parodontiittia. T1DM potilaiden parodontiitti hoidettiin, ja heidät tutkittiin uudelleen kahdeksan viikon kuluttua hoidon päättymisestä. Tutkittavilta tarkastettiin plakin määrä, ientaskujen syvyys, ienverenvuoto ja hampaiden kiinnityskudoksen menetys. Systeemistä tulehdustilaa mitattiin käyttäen seerumin interleukiini (IL)-6, tuumorinekroosifaktori (TNF)-α ja interleukiini (IL)-10 tasoja. Lisäksi määritettiin ientaskunesteen matriksimetalloproteinaasi (MMP)-8 taso. Kaikki edellä mainitut tulehduksen välittäjäainetasot määritettiin käyttäen ELISA-menetelmää. T1DM potilaiden seerumin IL-6 pitoisuuden ja tulehtuneiden ientaskujen määrän välillä vallitsi positiivinen yhteys. Lisäksi havaittiin, että seerumin korkea IL-6 taso heikensi parodontiitin paranemista. T1DM potilailla havaittiin käänteinen yhteys seerumin HDL-pitoisuuden ja tulehtuneiden ientaskujen määrän välillä. Tutkittavilla, joilla seerumin HDL-taso oli matala (<1.35 mmol/l), oli 50 % enemmän tulehtuneita ientaskuja kuin niillä, joilla HDL-taso oli korkea (≥1.35). Parodontiitti-ryhmässä seerumin TNF-α/IL-10 suhde oli kolminkertainen verrattuna kontrolliryhmän vastaavaan ilmentäen voimakkaampaa matala-asteista tulehdusta parodontiitti-potilailla. Matalista (<4 mm) ientaskuista kerätyn ientasunesteen MMP-8 pitoisuuden ja parodontiitin vaikeusasteen välillä vallitsi merkittävä postiivinen yhteys parodontiitti-potilailla. Yhteenvetona, systeemisen tulehdustilan ja hampaiden kiinnityskudosten välillä vallitsee kaksisuuntainen yhteys; toisaalta parodontiitti lisää matala-asteista systeemistä tulehdustilaa ja toisaalta kohonnut systeeminen tulehdustila lisää alttiutta parodontiittiin ja siihen liittyvään inflammaatioon. Lisäksi ientaskunesteen korkea MMP-8 pitoisuus matalissa ientaskuissa voi merkitä lisääntynyttä alttiutta parodontiumin alueen tulehdukselle ja kudostuholle.
154

Caractérisation métrologique de méthodes de références primaires candidates pour l’énumération des lipoprotéines et le dosage de l’hémoglobine glyquée HbA1c / Metrological characterization of candidate primary reference methods for the enumeration of lipoprotein particles and the absolute quantification of glycated hemoglobin HbA1c

Clouet, Noémie 11 September 2017 (has links)
En biologie clinique, disposer de mesures fiables et comparables, indépendamment du temps et du laboratoire, est primordial afin de permettre une prise en charge et un suivi adaptés des patients. Le moyen privilégié est d’établir la traçabilité métrologique des résultats de mesure aux unités du système international (SI), notamment par le biais de méthodes de référence et de matériaux de référence certifiés d’ordre supérieur. Ces travaux de thèse se sont attachés à caractériser deux méthodes de référence primaires candidates. Une méthode d’énumération absolue des lipoprotéines par ES-DMA pour l’évaluation du risque cardiovasculaire a été développée et caractérisée. Les résultats obtenus ont mis en évidence certaines limitations instrumentales rendant l’établissement de la traçabilité au SI difficile. Malgré les avantages certains de cette méthode pour l’analyse avancée de lipoprotéines, la fidélité et la robustesse des mesures ne sont pas suffisantes pour la considérer comme méthode de référence primaire. Une méthode de quantification de l’hémoglobine glyquée HbA1c, un biomarqueur du diabète sucré, par LC-MS/MS associée à la dilution isotopique a été mise en place et validée. La traçabilité au SI des résultats de dosage a été établie, toutefois, les incertitudes de mesures demeurent élevées et la comparabilité avec la méthode de référence IFCC reste à évaluer sur un nombre plus significatif d’échantillons et de laboratoires. Pour conclure, ces travaux ont mis en évidence les défis associés à la mise en place de nouvelles chaînes de traçabilité ainsi que les problématiques liées au développement de méthodes de référence primaires pour le dosage de biomarqueurs complexes. / Ensuring reliability and between-laboratory comparability of in-vitro diagnostic test results is essential for appropriate and internationally harmonized decision making and patient follow-up. To this end, a privileged way is to establish results metrological traceability to the international system of units (SI) through the development of primary reference methods and higher order reference materials. This thesis aimed at characterizing two candidate primary reference procedures.A method for lipoprotein absolute quantification by ES-DMA for cardiovascular diseases risk assessment was developed and characterized. Results evidenced some advantages of this method compared to other advanced lipoprotein testing assays, but some instrumental weaknesses make the establishment of results traceability to the SI difficult in the current state-of-the-art. Precision and robustness are additionally not sufficient for this method to be considered as a primary reference method.A method for the quantification of glycated hemoglobin HbA1c, a biomarker of diabetes mellitus, by LC/MS/MS associated to isotopic dilution was implemented and validated. Results traceability to the SI units could successfully be established. However, measurement uncertainties remain large and comparability with the IFCC reference method is still to be further assessed on a significant number of samples and laboratories.To conclude, this study highlighted the challenges associated with the implementation of new traceability chains and the difficulties related to the development and characterization of primary reference procedures for the quantification of complex biological markers.
155

Nouveaux rôles de l'apolipoprotéine E dans le cycle du virus de l'hépatite C : Docteur Jekyll ou Mister Hyde ? / New roles of apolipoprotein E in HCV life cycle : Doctor Jekyll or Mister Hyde?

Crouchet, Émilie 09 September 2016 (has links)
L’infection par le virus de l’hépatite C (HCV) est une cause majeure d’hépatite chronique, de cirrhose hépatique et ce carcinome hépatocellulaire dans le monde. La compréhension des relations entre le virus et sa cellule hôte, l’hépatocyte, est indispensable pour le développement de nouvelles stratégies thérapeutiques et d’un vaccin préventif. La particularité de ce virus est son lien étroit avec le métabolisme lipidique. Le virus circule dans le sang associé aux lipoprotéines, formant une lipo-viro-particule (LVP) infectieuse. L’apolipoprotéine E (apoE) est une protéine cellulaire faisant intégralement partie de la LVP. Elle joue un rôle majeur dans l’infection et à la production des particules virales. Durant ce travail de thèse, j’ai pu approfondir les connaissances sur le rôle d’apoE dans le cycle viral du HCV sous deux aspects très différents. D’une part, j’ai pu démontré que la forme libre d’apoE, non liée aux lipoprotéines, inhibe la réplication du HCV grâce à la régulation du métabolisme lipidique hépatique, en induisant un efflux de cholestérol ABCG1-dépendant. D’autre part, j’ai participé à une étude démontrant que l’apoE liée à la LVP contribue à l’échappement du virus au système immunitaire, en masquant les épitopes de la protéine virale E2 aux anticorps neutralisants. Ces études ont mis en évidence deux nouveaux rôles d’apoE dans la pathogenèse du HCV. / Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. Understanding virus-host interactions in hepatocytes will contribute towards the development of new therapeutic strategies and a protective vaccine. HCV life cycle and the lipid metabolism are inextricably intertwined. A particular feature of this virus is that, in the blood, HCV virions are associated with lipoproteins, forming an infectious lipoviroparticle (LVP). Apolipoprotein E (apoE) is a key component of LVPs that plays an essential role in HCV entry and virions production. My PhD project entailed a more detailed dissection of apoE’s role in the HCV life cycle. I demonstrated that lipid-free apoE inhibits HCV replication by regulating the hepatic lipid metabolism via an ABCG1-dependent cholesterol efflux. Furthermore, I contributed to a study demonstrating that LVP-associated apoE helps the virus escape host immunity by blocking access of neutralizing antibodies to the viral glycoprotein E2. The work presented highlights two new roles of apoE in HCV pathogenesis
156

Efeito do dispositivo endoscópico temporário de exclusão duodeno jejunal na resistência insulínica e no risco cardiovascular em pacientes obesos com diabetes tipo 2 / Effect of the duodeno jejunal bypass liner in insulin resistance and cardiovascular risk in obese patients with type 2 diabetes

Ivan Roberto Bonotto Orso 08 October 2013 (has links)
OBJETIVO: Avaliar a eficácia do dispositivo endoscópico temporário de exclusão duodeno jejunal (DEED) na redução da resistência à insulina e do risco cardiovascular em pacientes obesos mórbidos portadores de diabetes tipo 2 (DMT2), utilizando a relação Triglicerídeos/colesterol HDL (TG/HDL), porcentagem de perda de peso e controle glicêmico. MÉTODO: Neste estudo foram incluídos 54 pacientes implantados com o DEED e acompanhados por um período de 6 meses. Todos apresentavam uma relação TG/HDL com valor acima de 3,5, sugerindo uma maior resistência insulínica e um perfil lipídico compatível com um maior risco cardiovascular. O valor da relação inicial foi comparado com o valor obtido após 6 meses do implante do dispositivo, com o objetivo de avaliar se houve redução desse valor, indicando melhora na resistência insulínica e redução do risco cardiovascular. Também foi avaliada a melhora dos níveis de hemoglobina glicada (HbA1c) e a perda de peso obtida com o uso do dispositivo. Estes dois últimos achados foram correlacionados com a redução da relação TG/HDL para avaliar a presença de dependência entre os fatores. RESULTADOS: Todos os pacientes implantados com o DEED apresentaram redução significativa dos níveis de HbA1c, sendo que a maior parte dos pacientes (70,3%) obtiveram o controle do diabetes, com níveis abaixo de 7% ao final do estudo. Todos os pacientes também apresentaram redução do peso, com perda média de 12,6% do peso absoluto inicial. Foi observada redução da relação TG/HDL de 5,75 para 4,36 ao final do estudo (p 0,0001), com 42,6% dos pacientes apresentando relação final abaixo de 3,5. A melhora da relação TG/HDL apresentou uma importante associação com uma perda de peso maior que 10% do peso inicial. CONCLUSÃO: O DEED mantido por um período de 6 meses é eficaz na obtenção do controle do diabetes tipo 2, perda de peso e redução da relação TG/HDL em pacientes obesos mórbidos portadores de diabetes mellitus tipo 2. Porém, a melhora da relação TG/HDL está fortemente associada à perda de mais de 10% do peso inicial / OBJECTIVE: To evaluate the efficacy of the duodeno jejunal bypass liner (DJBL) in reducing insulin resistance and cardiovascular risk in morbidly obese patients with type 2 diabetes (T2DM). For this purpose we used the Triglycerides / HDL cholesterol ratio (TG / HDL), percentage of weight loss and glycemic control. METHODS: This study included 54 patients implanted with the DJBL and followed for a period of 6 months. All had a TG / HDL ratio equal or above 3.5, suggesting greater insulin resistance and lipid profile consistent with increased cardiovascular risk. The initial value of the ratio was compared with the value obtained 6 months after the device implantation, in order to assess whether this value decreased, indicating an improvement in insulin resistance and reduction in the cardiovascular risk. We also evaluated the improvement in glycated hemoglobin (HbA1c) and weight loss achieved with the device, and its relationship with the reduction of TG/HDL ratio. RESULTS: All patients implanted with the DJBL showed significant reduction in HbA1c levels. Most patients (70.3%) achieved diabetes control, with HbA1c levels below 7% by the end of the study. All patients also had a statistically significant weight reduction, with an average loss of 12.6% of initial weight. We observed an important improvement in insulin resistance and metabolic syndrome, with a significant reduction of the TG/HDL ratio from 5.75 to 4.36 (p = 0.0001) and 42.6% of the patients presenting a TG/HDL ratio lower than 3.5 at the end of the study. The improvement of the TG / HDL ratio presented a significant association with weight loss greater than 10% of initial weight. CONCLUSION: The DJBL maintained for a period of 6 months is effective in obtaining control of type 2 diabetes, weight loss and reduction in the TG / HDL ratio in morbidly obese patients with diabetes mellitus type 2. However, the improvement of the TG / HDL ratio is strongly associated with loss of more than 10% of the initial weight
157

Heterogeneidade e mecanismos moleculares da atividade anti-apoptótica das subfrações de HDL em células endoteliais humanas / Heterogeneity and molecular mechanisms of anti-apoptotic activity of high-density lipoprotein (HDL) subfractions on endothelial cells

Juliana Ascenção de Souza 19 March 2007 (has links)
Introdução: A lipoproteína de baixa densidade (LDL) e suas formas oxidadas (LDLox) possuem múltiplas propriedades aterogênicas, atuando na deposição de colesterol, indução e manutenção da inflamação, disfunção endotelial, surgimento de células espumosas na parede arterial e conseqüente formação da placa de ateroma. Adicionalmente, LDLox induz apoptose de células endoteliais humanas (HMEC). A lipoproteína de alta densidade (HDL) possui inúmeras atividades antiaterogênicas, incluindo ações antioxidante, anti-inflamatória e anti-trombótica. A HDL é capaz de proteger as HMEC contra apoptose. As subfrações de HDL (sHDL) são heterogêneas em sua composição físico-química e atividades biológicas. A atividade antioxidante das sHDL aumenta com a densidade (HDL2b<HDL2a<HDL3a<HDL3b <HDL3c) e está deficiente em pacientes com SMet. Contudo, a heterogeneidade da atividade anti-apoptótica das sHDL é ainda desconhecida. Objetivos: (i) avaliar a heterogeneidade da atividade protetora das sHDL de indivíduos normolipidêmicos (n=7) e de pacientes com SMet (n=16) contra apoptose de HMEC induzida por LDLox; (ii) definir os mecanismos moleculares envolvidos nesta atividade. Métodos: Através de ultracentrifugação por gradiente de densidade, isolamos cinco diferentes sHDL. HMEC foram incubadas com LDLox (200 ?g apoB/ml) na presença ou não das sHDL (5-100 ?g proteína/ml). Os marcadores de toxicidade (MTT) e de apoptose celular (microscopia de fluorescência, marcagem com anexina V, cit c, AIF, degradação Bid, atividade caspase-3 e fragmentação do ADN) foram analisados. Resultados: Todas sHDL protegeram as HMEC contra a toxicidade e apoptose induzidas pela LDLox. Com mesma concentração de proteína, as subfrações HDL3c (60% proteção - MTT - e >100% - anexina V) e 3b (43% e 67%, respectivamente) de indivíduos normolipidêmicos apresentaram atividade anti-apoptótica mais potente do que as subfrações HDL2a (29% e 28%; p<0,01 vs. HDL3c, respectivamente) e 2b (25% e 62%; p<0,001 vs. HDL3c, respectivamente). Todas sHDL reduziram geração de espécies reativas de oxigênio (ROS) induzida pela LDLox, sendo a HDL3c (54%) mais potente do que HDL2b (21%; p<0.05 vs. HDL3c). Houve correlação positiva entre as atividades anti-apoptótica e antioxidante intracelular com conteúdo de apoA-I e esfingosina 1-fosfato (E1F) das sHDL, senda HDL3b e 3c ricas em E1F. A atividade anti-apoptótica da E1F e das sHDL parece depender da interação com as células endoteliais via apoA-I e seu receptor SR-BI. Finalmente, as HDL3c (n=5) isoladas de pacientes com SMet possuem conteúdo significativamente menor de apoA-I e reduzida atividade anti-apoptótica (60%, p<0,01), quando comparada aos controles normolipidêmicos (n=5). Houve tendência à diminuição da proteção contra a geração de ROS (SMet, n=10). Conclusão: As subfrações HDL3c protegem de forma potente as células endoteliais humanas contra toxicidade e apoptose induzidas pela LDLox, assim como contra geração de ROS. Esta atividade antiapoptótica está reduzida na SMet. / Background: Low density lipoprotein (LDL) and its oxidized forms (oxLDL) have several atherogenic properties, including cholesterol deposition, inflammation, endothelial dysfunction and foam cell formation on the arterial wall, leading to atherosclerotic plaque development. In addition, oxLDL induces human endothelial cell apoptosis (HMEC). High-density lipoprotein (HDL) has number of antiatherogenic activities, as antioxidative, anti-inflammatory and anti-thrombotic actions. HDL displays anti-apoptotic activity and is able to protect endothelial cells against oxLDL-induced apoptosis. HDL subfractions (sHDL) are highly heterogeneous in their physical and chemical composition and biological functions. Antioxidative activity of HDL subfractions increases with increment in density, HDL2b<HDL2a<HDL3a<HDL3b <HDL3c. Important, HDL subfractions from subjects with metabolic syndrome (MetS), display a significantly lower antioxidative activity as compared to healthy controls. However, the heterogeneity of their anti-apoptotic activity was not demonstrated. Objectives: (i) to evaluate the heterogeneity of antiapoptotic activity of sHDL from normolipidemic controls (n=7) and MetS patients (n=16) towards oxLDL-induced apoptosis of HMEC; (ii) to define molecular mechanisms involved in this anti-apoptotic action. Methods: Five major sHDL were fractionated by density gradient ultracentrifugation. HMEC were incubated with mildly oxLDL (200 ?g apoB/ml) in the presence or absence of each sHDL (5-100 ?g protein/ml). Markers of cellular toxicity (MTT) and apoptosis (fluorescent nucleic acid staining, annexin V binding, cytochrome c, AIF and Bid, caspase-3 activity and DNA fragmentation) were observed. Results: All HDL subfractions isolated from normolipidemic subjects protected HMEC against oxLDL-induced toxicity and apoptosis. At equal protein concentrations, HDL3c (60% protection in the MTT test; >100% in annexin V biding) and 3b subfractions (43% and 67%, respectively) were more potent against oxLDL-induced toxicity and apoptosis as compared to HDL2a (29% and 28%; p<0.01 vs. HDL3c, respectively) and 2b subfractions (25% and 62%; p<0.001 vs. HDL3c, respectively). All HDL subfractions attenuated of reactive oxygen species (ROS) generation in HMEC induced by oxLDL. Again, HDL3c (54% inhibition) were more potent as compared to HDL2b (21%; p<0.05 vs. HDL3c). The anti-apoptotic and intracellular antioxidative activities of HDL3 were positively correlated with apoA-I and sphingosine 1-phosphate (S1P) content of sHDL and, possibly, depend on their cellular interaction through apoA-I and its SR-BI receptor. The sHDL3c isolated from MetS patients (n=5) possess reduced content of apoA-I and less potent anti-apoptotic activity (-60%, p<0.01) than controls (n=5). Conclusion: Normolipidemic small dense HDL3 provide potent protection of human endothelial cells from oxLDL-induced apoptosis; this anti-apoptotic activity is reduced in the MetS.
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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
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Content assist in integrated development environments for hardware description languages / Automatisk komplettering i integrerade utvecklingsmiljöer för hårdvarubeskrivningsspråk

Nadjar, David January 2023 (has links)
Content assist is one of the most powerful features in integrated development environments (IDE). While a lot of research papers exist on content assist for software programming languages (SPL), hardware description languages (HDL) aren’t covered at all. In this thesis, we improve content assist for SystemVerilog, one of the most widely used HDL, by using different ordering strategies and comparing them to each other. In the end, 6 different strategies are kept: two based on frequencies, one on the usage of the content assist, one on the name of the variable, one on the type of the variable, and one on the distance from their declaration to the cursor position. We test our implementation in 3 different open-source projects well-known and used by the SystemVerilog community: OpenTitan, SweRV, and riscv-dv. We achieve having the expected entry in the top 5 in more than 40% of cases with no prefix and up to 66% of cases with 1 character already typed. / Automatisk komplettering är en av de mest kraftfulla funktionerna i integrerade utvecklingsmiljöer (integrated development environments, IDE). Även om det finns många forskningsartiklar om automatisk komplettering för mjukvaruprogrammeringsspråk (software programming languages, SPL), täcks inte hårdvarubeskrivningsspråk (hardware description language, HDL) alls. I det här examensarbetet förbättras innehållshjälp för SystemVerilog, en av de mest använda HDL:erna, genom att använda olika ordningsstrategier och jämföra dem med varandra. Slutligen behålls 6 olika strategier: två baserade på frekvenser, en baserad på användningen av automatisk komplettering, en baserad på variabelns namn, en baserad på variabelns typ och en baserad på avståndet från deras deklaration till markörens position. Implementeringen testas i 3 olika open source-projekt som är välkända och används av SystemVerilog-användarna: OpenTitan, SweRV och riscvdv. Implementeringen föreslog den förväntade termen bland de fem första förslagen i 40% av fallen där inget prefix var givet och i 66% av fallen när ett tecken var givet
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Validation Of A Novel Hypothesis Of Generating Foam Cells By Its Use To Study Reverse Cholesterol Transport

Sengupta, Bhaswati 01 January 2014 (has links)
Generation of foam cells, an essential step for reverse cholesterol transport (RCT) studies, uses the technique of receptor dependent macrophage loading with radiolabeled acetylated Low Density Lipoprotein (Ac-LDL). In this study, we used the ability of a biologically relevant detergent molecule, Lysophosphatidylcholine (Lyso PtdCho), to form mixed micelles with cholesterol or cholesteryl ester (CE) to generate macrophage foam cells. Fluorescent or radiolabelled cholesterol / Lyso PtdCho mixed micelles were prepared and incubated with RAW 264.7 or mouse peritoneal macrophages. Results showed that such micelles were quite stable at 4°C and retained the solubilized cholesterol during one month storage. Macrophages incubated with cholesterol or CE (unlabeled, fluorescently labeled or radiolabeled) / Lyso PtdCho mixed micelles accumulated CE as documented by microscopy, lipid staining, labeled oleate incorporation, and by thin layer chromatography (TLC). Such foam cells unloaded cholesterol when incubated with high density lipoprotein (HDL) and not with oxidized HDL (Ox-HDL). We propose that stable cholesterol or CE / Lyso PtdCho micelles would offer advantages over existing methods. Oxidative stress is associated with heart failure (HF). Previously our research group observed that the patients with low left-ventricular ejection fraction showed accumulation of high level of oxidized LDL (Ox-LDL) when compared with the heart failure patients with normal range of ejection fraction (EF). HDL is known to be atheroprotective and one of its important antioxidative functions is to protect LDL from oxidative modifications. However, HDL itself undergoes oxidation and Ox-HDL becomes functionally poor. It is expected to have a diminished ability to promote reverse cholesterol transport. Therefore, it was hypothesized that the quality of HDL present in the patients with EF would more compromised than those present in the patients with normal EF. Functionality of HDL was evaluated by measuring its cholesterol efflux capacity from foam cells generated in vitro. Functionality of HDL, which is strongly related to the oxidative modifications of HDL was further estimated by measuring paraoxonase 1 (PON1) enzyme activity associated with HDL. Higher the PON1 activity and RCT ability, better is the functionality of HDL.

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