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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.
11

Efeito de uma sobrecarga aguda de ácidos graxos monoinsaturados e saturados nos níveis séricos de GLP-1 e PYY em ratos wistar

Jornada, Manoela Neves da January 2012 (has links)
Introdução: A prevalência de doenças crônicas tem crescido em decorrência do aumento da obesidade nos últimos anos. Peptídeos secretados pelo trato gastrointestinal, como o peptídeo semelhante ao glucagon 1 (GLP-1) e o peptídeo YY (PYY), exercem papel fundamental no controle da ingestão alimentar, pois levam informações acerca dos nutrientes ingeridos até o sistema nervoso central, possuindo efeitos anorexígenos e/ou orexígenos. Tanto GLP-1 quanto PYY são produzidos pelas células-L do íleo distal e cólon, sendo liberados após a ingestão alimentar. Além do efeito incretina produzido pelo GLP-1, ambos os peptídeos apresentam implicações no controle do apetite, o qual reflete na redução do peso corpóreo. Objetivos: Demonstrar um aumento na secreção de GLP-1 e PYY após sobrecarga oral de diferentes tipos de lipídios, comparados à controle negativo (água) e positivo (glicose). Métodos: Foi realizado um estudo experimental controlado em ratos Wistar, distribuídos em 4 grupos de acordo com a sobrecarga oral: grupo MUFA (óleo de oliva); grupo SAT (banha suína); grupo GLUC (glicose) e grupo CONT (água), foram avaliadas as concentrações séricas de GLP-1 ativo e PYY3-36 nos tempos: 0, 15, 30, 60 e 120 minutos. As sobrecargas foram isovolumétricas e isocalóricas, com exceção do grupo controle. Resultados: Houve pico de secreção do GLP-1 pós-sobrecarga no grupo MUFA no ponto 120’ vs CONT e GLUC (p≤0,001) e no ponto 30’ quando comparado ao seu baseline. Também observou-se pico de secreção de PYY no grupo MUFA vs CONT no ponto 30’ (p=0,015); no ponto 60’ vs CONT e GLUC (p=0,019) e no ponto 120’ vs CONT e SAT (p=0,02). A carga secretada do PYY foi maior no MUFA quando comparada ao CONT (p=0,04). Verificou-se forte correlação entre os níveis basais e AUC’s do GLP-1 e PYY (r=0,57; (p= 0,02); r=0,39; (p≤0,001)). A proporção GLP-1/PYY apresentou um coeficiente médio de 3,77 (±2,04). O grupo MUFA evidenciou níveis menores de glicose e maiores de insulina no ponto 15’, enquanto SAT mostrou níveis maiores de glicose e menores de insulina neste ponto, porém, sem diferença significativa. Conclusão: A sobrecarga oral de fontes de ácidos graxos monoinsaturados promoveu um pico de secreção do GLP-1 de forma rápida e no que diz respeito ao PYY, o pico foi mais sustentado. Estudos adicionais são necessários, a fim de se avalir o efeito de fontes distintas de lipídeos da dieta sobre a secreção destes peptídeos e seus efeitos na saciedade. / Background: The increased prevalence of chronic diseases has risen due to obesity. Gut peptides, such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), play an important role controlling food intake in response to a meal. GLP-1 exerts the known incretin effect stimulating the release of insulin in a glucosedependent manner. Besides its insulinotropic effects, it is well established that GLP-1 slows gastric emptying, and also inhibits inappropriate glucagon release, additionally improves satiety. Both PYY and GLP-1 are produced by L cells of the distal ileum and colon. Objective: Demonstrate an increased secretion of PYY and GLP-1 after oral overload of different types of lipids, compared to negative (water) and positive (glucose) control. Methods: We conducted a controlled experimental study in Wistar rats, divided into 4 groups according to oral overload: MUFA group (olive oil), SAT group (lard:), carbohydrates group (glucose) and CONT group (water), It was evaluated the serum concentration of active GLP-1 and PYY3-36 in the times: 0, 15, 30, 60 and 120 minutes. Overloads were isovolumetric and isocaloric, but the control group. Results: It was verified a higher peak secretion of GLP-1 in MUFA group at 120' after overload vs. CONT and carbohydrates (p ≤ 0.001) and at 30' when compared to its baseline (p=0,01). It was shown a higher secretion peak of GLP-1 after MUFA overload at time 120’ vs CONT e GLUC (p≤0,001) and at time 30’ when compared to its baseline. It was also verified a PYY release peak in MUFA vs CONT at time 30’ (p=0,015); 60’ vs CONT e GLUC (p=0,019) and 120’ vs CONT e SAT (p=0,02). PYY release load presented higher in MUFA group when compared to CONT (p=0,04). A strong correlation was seen between baseline PYY and GLP-1 (r=0,57; p= 0,02) as their AUC’s (r=0,39; p≤0,001). GLP-1/PYY proportion release presented a mean coefficient of 3, 77(±2,04).Conclusion: monounsaturated fatty acids promoted a release peak of GLP-1 in a faster manner and concerning PYY this peak was more sustained. Further studies are necessary to evaluate whether distinct diet fatty acids can ameliorate these gut peptides release and their role on satiety.
12

Efeito de uma sobrecarga aguda de ácidos graxos monoinsaturados e saturados nos níveis séricos de GLP-1 e PYY em ratos wistar

Jornada, Manoela Neves da January 2012 (has links)
Introdução: A prevalência de doenças crônicas tem crescido em decorrência do aumento da obesidade nos últimos anos. Peptídeos secretados pelo trato gastrointestinal, como o peptídeo semelhante ao glucagon 1 (GLP-1) e o peptídeo YY (PYY), exercem papel fundamental no controle da ingestão alimentar, pois levam informações acerca dos nutrientes ingeridos até o sistema nervoso central, possuindo efeitos anorexígenos e/ou orexígenos. Tanto GLP-1 quanto PYY são produzidos pelas células-L do íleo distal e cólon, sendo liberados após a ingestão alimentar. Além do efeito incretina produzido pelo GLP-1, ambos os peptídeos apresentam implicações no controle do apetite, o qual reflete na redução do peso corpóreo. Objetivos: Demonstrar um aumento na secreção de GLP-1 e PYY após sobrecarga oral de diferentes tipos de lipídios, comparados à controle negativo (água) e positivo (glicose). Métodos: Foi realizado um estudo experimental controlado em ratos Wistar, distribuídos em 4 grupos de acordo com a sobrecarga oral: grupo MUFA (óleo de oliva); grupo SAT (banha suína); grupo GLUC (glicose) e grupo CONT (água), foram avaliadas as concentrações séricas de GLP-1 ativo e PYY3-36 nos tempos: 0, 15, 30, 60 e 120 minutos. As sobrecargas foram isovolumétricas e isocalóricas, com exceção do grupo controle. Resultados: Houve pico de secreção do GLP-1 pós-sobrecarga no grupo MUFA no ponto 120’ vs CONT e GLUC (p≤0,001) e no ponto 30’ quando comparado ao seu baseline. Também observou-se pico de secreção de PYY no grupo MUFA vs CONT no ponto 30’ (p=0,015); no ponto 60’ vs CONT e GLUC (p=0,019) e no ponto 120’ vs CONT e SAT (p=0,02). A carga secretada do PYY foi maior no MUFA quando comparada ao CONT (p=0,04). Verificou-se forte correlação entre os níveis basais e AUC’s do GLP-1 e PYY (r=0,57; (p= 0,02); r=0,39; (p≤0,001)). A proporção GLP-1/PYY apresentou um coeficiente médio de 3,77 (±2,04). O grupo MUFA evidenciou níveis menores de glicose e maiores de insulina no ponto 15’, enquanto SAT mostrou níveis maiores de glicose e menores de insulina neste ponto, porém, sem diferença significativa. Conclusão: A sobrecarga oral de fontes de ácidos graxos monoinsaturados promoveu um pico de secreção do GLP-1 de forma rápida e no que diz respeito ao PYY, o pico foi mais sustentado. Estudos adicionais são necessários, a fim de se avalir o efeito de fontes distintas de lipídeos da dieta sobre a secreção destes peptídeos e seus efeitos na saciedade. / Background: The increased prevalence of chronic diseases has risen due to obesity. Gut peptides, such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), play an important role controlling food intake in response to a meal. GLP-1 exerts the known incretin effect stimulating the release of insulin in a glucosedependent manner. Besides its insulinotropic effects, it is well established that GLP-1 slows gastric emptying, and also inhibits inappropriate glucagon release, additionally improves satiety. Both PYY and GLP-1 are produced by L cells of the distal ileum and colon. Objective: Demonstrate an increased secretion of PYY and GLP-1 after oral overload of different types of lipids, compared to negative (water) and positive (glucose) control. Methods: We conducted a controlled experimental study in Wistar rats, divided into 4 groups according to oral overload: MUFA group (olive oil), SAT group (lard:), carbohydrates group (glucose) and CONT group (water), It was evaluated the serum concentration of active GLP-1 and PYY3-36 in the times: 0, 15, 30, 60 and 120 minutes. Overloads were isovolumetric and isocaloric, but the control group. Results: It was verified a higher peak secretion of GLP-1 in MUFA group at 120' after overload vs. CONT and carbohydrates (p ≤ 0.001) and at 30' when compared to its baseline (p=0,01). It was shown a higher secretion peak of GLP-1 after MUFA overload at time 120’ vs CONT e GLUC (p≤0,001) and at time 30’ when compared to its baseline. It was also verified a PYY release peak in MUFA vs CONT at time 30’ (p=0,015); 60’ vs CONT e GLUC (p=0,019) and 120’ vs CONT e SAT (p=0,02). PYY release load presented higher in MUFA group when compared to CONT (p=0,04). A strong correlation was seen between baseline PYY and GLP-1 (r=0,57; p= 0,02) as their AUC’s (r=0,39; p≤0,001). GLP-1/PYY proportion release presented a mean coefficient of 3, 77(±2,04).Conclusion: monounsaturated fatty acids promoted a release peak of GLP-1 in a faster manner and concerning PYY this peak was more sustained. Further studies are necessary to evaluate whether distinct diet fatty acids can ameliorate these gut peptides release and their role on satiety.
13

Efeito de uma sobrecarga aguda de ácidos graxos monoinsaturados e saturados nos níveis séricos de GLP-1 e PYY em ratos wistar

Jornada, Manoela Neves da January 2012 (has links)
Introdução: A prevalência de doenças crônicas tem crescido em decorrência do aumento da obesidade nos últimos anos. Peptídeos secretados pelo trato gastrointestinal, como o peptídeo semelhante ao glucagon 1 (GLP-1) e o peptídeo YY (PYY), exercem papel fundamental no controle da ingestão alimentar, pois levam informações acerca dos nutrientes ingeridos até o sistema nervoso central, possuindo efeitos anorexígenos e/ou orexígenos. Tanto GLP-1 quanto PYY são produzidos pelas células-L do íleo distal e cólon, sendo liberados após a ingestão alimentar. Além do efeito incretina produzido pelo GLP-1, ambos os peptídeos apresentam implicações no controle do apetite, o qual reflete na redução do peso corpóreo. Objetivos: Demonstrar um aumento na secreção de GLP-1 e PYY após sobrecarga oral de diferentes tipos de lipídios, comparados à controle negativo (água) e positivo (glicose). Métodos: Foi realizado um estudo experimental controlado em ratos Wistar, distribuídos em 4 grupos de acordo com a sobrecarga oral: grupo MUFA (óleo de oliva); grupo SAT (banha suína); grupo GLUC (glicose) e grupo CONT (água), foram avaliadas as concentrações séricas de GLP-1 ativo e PYY3-36 nos tempos: 0, 15, 30, 60 e 120 minutos. As sobrecargas foram isovolumétricas e isocalóricas, com exceção do grupo controle. Resultados: Houve pico de secreção do GLP-1 pós-sobrecarga no grupo MUFA no ponto 120’ vs CONT e GLUC (p≤0,001) e no ponto 30’ quando comparado ao seu baseline. Também observou-se pico de secreção de PYY no grupo MUFA vs CONT no ponto 30’ (p=0,015); no ponto 60’ vs CONT e GLUC (p=0,019) e no ponto 120’ vs CONT e SAT (p=0,02). A carga secretada do PYY foi maior no MUFA quando comparada ao CONT (p=0,04). Verificou-se forte correlação entre os níveis basais e AUC’s do GLP-1 e PYY (r=0,57; (p= 0,02); r=0,39; (p≤0,001)). A proporção GLP-1/PYY apresentou um coeficiente médio de 3,77 (±2,04). O grupo MUFA evidenciou níveis menores de glicose e maiores de insulina no ponto 15’, enquanto SAT mostrou níveis maiores de glicose e menores de insulina neste ponto, porém, sem diferença significativa. Conclusão: A sobrecarga oral de fontes de ácidos graxos monoinsaturados promoveu um pico de secreção do GLP-1 de forma rápida e no que diz respeito ao PYY, o pico foi mais sustentado. Estudos adicionais são necessários, a fim de se avalir o efeito de fontes distintas de lipídeos da dieta sobre a secreção destes peptídeos e seus efeitos na saciedade. / Background: The increased prevalence of chronic diseases has risen due to obesity. Gut peptides, such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), play an important role controlling food intake in response to a meal. GLP-1 exerts the known incretin effect stimulating the release of insulin in a glucosedependent manner. Besides its insulinotropic effects, it is well established that GLP-1 slows gastric emptying, and also inhibits inappropriate glucagon release, additionally improves satiety. Both PYY and GLP-1 are produced by L cells of the distal ileum and colon. Objective: Demonstrate an increased secretion of PYY and GLP-1 after oral overload of different types of lipids, compared to negative (water) and positive (glucose) control. Methods: We conducted a controlled experimental study in Wistar rats, divided into 4 groups according to oral overload: MUFA group (olive oil), SAT group (lard:), carbohydrates group (glucose) and CONT group (water), It was evaluated the serum concentration of active GLP-1 and PYY3-36 in the times: 0, 15, 30, 60 and 120 minutes. Overloads were isovolumetric and isocaloric, but the control group. Results: It was verified a higher peak secretion of GLP-1 in MUFA group at 120' after overload vs. CONT and carbohydrates (p ≤ 0.001) and at 30' when compared to its baseline (p=0,01). It was shown a higher secretion peak of GLP-1 after MUFA overload at time 120’ vs CONT e GLUC (p≤0,001) and at time 30’ when compared to its baseline. It was also verified a PYY release peak in MUFA vs CONT at time 30’ (p=0,015); 60’ vs CONT e GLUC (p=0,019) and 120’ vs CONT e SAT (p=0,02). PYY release load presented higher in MUFA group when compared to CONT (p=0,04). A strong correlation was seen between baseline PYY and GLP-1 (r=0,57; p= 0,02) as their AUC’s (r=0,39; p≤0,001). GLP-1/PYY proportion release presented a mean coefficient of 3, 77(±2,04).Conclusion: monounsaturated fatty acids promoted a release peak of GLP-1 in a faster manner and concerning PYY this peak was more sustained. Further studies are necessary to evaluate whether distinct diet fatty acids can ameliorate these gut peptides release and their role on satiety.
14

Thiol−ene Coupling of Renewable Monomers : at the forefront of bio-based polymeric materials

Claudino, Mauro January 2011 (has links)
Plant derived oils bear intrinsic double-bond functionality that can be utilized directly for the thiol–ene reaction. Although terminal unsaturations are far more reactive than internal ones, studies on the reversible addition of thiyl radicals to 1,2-disubstituted alkenes show that this is an important reaction. To investigate the thiol–ene coupling reaction involving these enes, stoichiometric mixtures of a trifunctional propionate thiol with monounsaturated fatty acid methyl esters (methyl oleate or methyl elaidate) supplemented with 2.0 wt.% Irgacure 184 were subjected to 365-nm UV-irradiation and the chemical changes monitored. Continuous (RT– FTIR) and discontinuous (NMR and FT–Raman) techniques were used to follow the progress of the reaction and reveal details of the products formed. Experimental results supported by numerical kinetic simulations of the system confirm the reaction mechanism showing a very fast cis/trans-isomerization of the alkene monomers (<1.0 min) when compared to the total disappearance of double-bonds, indicating that the rate-limiting step controlling the overall reaction is the hydrogen transfer from the thiol involved in the formation of final product. The loss of total unsaturations equals thiol consumption throughout the entire reaction; although product formation is strongly favoured directly from the trans-ene. This indicates that initial cis/trans-isomer structures affect the kinetics. High thiol–ene conversions could be easily obtained at reasonable rates without major influence of side-reactions demonstrating the suitability of this reaction for network forming purposes from 1,2-disubstituted alkenes. To further illustrate the validity of this concept in the formation of cross-linked thiol–ene films a series of globalide/caprolactone based copolyesters differing in degree of unsaturations along the backbone were photopolymerized in the melt with the same trithiol giving amorphous elastomeric materials with different thermal and viscoelastic properties. High thiol–ene conversions (>80%) were easily attained for all cases at reasonable reaction rates, while maintaining the cure behaviour and independent of functionality. Parallel chain-growth ene homopolymerization was considered negligible when compared with the main coupling route. However, the comonomer feed ratio had impact on the thermoset properties with high ene-density copolymers giving networks with higher glass transition temperature values (Tg) and a narrower distribution of cross-links than films with lower ene composition. The thiol–ene systems evaluated in this study serve as model example for the sustainable use of naturally-occurring 1,2-disubstituted alkenes at making semi-synthetic polymeric materials in high conversions with a range of properties in an environment-friendly way. / Vegetabiliska oljor som innehåller dubbelbindningar kan användas direkt för thiolene reaktioner. Trots att terminala dubbelbindningar är mycket mer reaktiva än interna visar dessa studier att den reversibla additionen av thiyl radikaler till 1,2-disubstituerade alkener är en viktig reaktion. För att undersöka tiol–ene reaktionerna, som ivolverar dessa alkener förbereddes stökiometriska blandningar av en trifunktionell propionat tiol och enkelomättade fettsyrametylestrar (metyloleat eller metyl elaidat) samt 2.0 vikt.% Irgacure 184. Dessa blandningar utsattes för 365-nm UV strålning och de kemiska förändringarna studerades. De kemiska förändringarna analyserades med olika kemiska analysmetoder; realtid RT–FTIR, NMR och FT–Raman. Dessa användes för att analysera de kemiska reaktionerna i realtid och följa bildandet av produkterna. Reaktionsmekanismen bekräftades med hjälp av experimentella data och beräkningar av numeriska och kinetiska simuleringar för systemet. Resultaten visar en mycket snabb cis/trans-isomerisering av alkenmonomeren (<1.0 min) jämfört med den totala förbrukningen av dubbelbindningarna, vilket indikerar att det hastighetsbegränsande steget kontrolleras av väteförflyttningen från tiolen till slutprodukten. Förbrukningen av den totala omättade kolkedjan är lika med tiolförbrukningen under hela reaktionen, även om bildandet av produkten gynnas från trans-enen. Detta indikerar att den första cis/trans-isomerstrukturen påverkar kinetiken. Höga tiol-ene utbyten kan enkelt erhållas relativt snabbt utan inverkan av sidoreaktioner. Detta innebär att denna reaktion kan användas som nätverksbildande reaktion för flerfunktionella 1,2-disubstituted alkenmonomerer. Vidare användes fotopolymerisation i smälta på en serie globalid/kaprolaktonbaserade sampolyestrar med varierad grad av omättnad med samma tritiol vilket resulterade i bildandet av amorfa elastomeriska material med olika termiska och viskoelastiska egenskaper. Hög omsättning (>80%) uppnåddes relativt enkelt för samtliga blandningar oberoende av den initiala funktionaliteten. Homopolymerisation av alkenen var försumbar i jämförelse med den tiol–en-reaktionen. Mängden alkengrupper har inverkan på härdplastsegenskaperna där en hög andel alken ger en nätstruktur med högre glastransitionstemperatur (Tg). Tiol–ene reaktionen utvärderades i modellsystem baserade på naturlig förekommande 1,2-disubstituterade alkener för att demonstrera konceptet med tiol-förnätade halvsyntetiska material. / QC 20110915
15

Efeitos dos diferentes ácidos graxos no metabolismo lipídico e estresse oxidativo em camundongos C57/BL alimentados com dieta hiperlipídica e rica em frutose / Effects of different fatty acids on lipid metabolism and oxidative stress in C57/BL mice fed a high fat diet and rich in fructose

Manca, Camila Sanches 30 June 2017 (has links)
A esteatose hepática não alcóolica está relacionada às causas crescentes de morbimortalidade de doenças hepáticas. Sua incidência está relacionada à obesidade e comorbidades vinculadas a esta, na qual tem despertado grande interesse na pesquisa. A modulação quantitativa da dieta pode promover ou retardar a patologia. Desta forma, terapias voltadas para retardar ou diminuir a esteatose hepática não alcóolica poderiam atenuar o dano hepático, melhorar a função hepática e reduzir sua progressão. Os objetivos do presente estudo foram: avaliar o consumo de óleos vegetais ricos em MUFAs e PUFAs usados comercialmente na prevenção ou redução da esteatose hepática analisando parâmetros do metabolismo lipídico hepático e sérico, estresse oxidativo e retardando a progressão de NAFLD. Material e Métodos: os animais foram divididos nos seguintes grupos: Controle (n=10) + HLF * (n=10); Grupo HLF * AZ (n=10); Grupo HLF* CN (n=10); Grupo HLF* S (n=10). Após 16 semanas de dieta e tratamento com os respectivos óleos, os animais foram anestesiados e o sangue retirado por punção cardíaca e os tecidos para as análises posteriores. Resultados: A oferta de uma dieta rica em gordura saturada (banha) + frutose ocasionou um aumento do peso no grupo HLF enquanto a administração dos respectivos óleos vegetais foi capaz de retardar o ganho de peso. O peso hepático e da soma dos tecidos adiposos epididimal e retroperitonial foi maior no HLF enquanto houve redução significativa no peso hepático HLF/S. O tecido retroperitonial foi menor no HLF/CN. De uma maneira geral o tratamento com os respectivos óleos vegetais diminui a esteatose em todos os grupos experimentais. A oferta de azeite extra virgem não refletiu no ganho de peso, porém o grupo teve um aumento significativo de TG e VLDL séricos, com diminuição do colesterol sérico. Avaliado histologicamente diminuiu o score de esteatose quando comparado ao HLF sendo classificado como esteatose macro e microvesicular de leve a moderada. O óleo de soja apresentou uma maior quantidade de PUFAs, sendo rico em n-6, refletiu na manutenção do peso dos animais, diminuiu a esteatose, sendo classificado como esteatatose leve, quando comparado ao HLF, porém aumentou o colesterol sérico. Apresentou um aumento de MDA e diminuição de GSH hepático. O óleo de canola devido a seu teor em ácidos graxos PUFAs (n-6 e n-3) teve maior incorporação do EPA e DHA que parecem ter evidenciado positivamente. Não apresentou alteração nos parâmetros bioquímicos e apresentou menor acúmulo de gordura hepática através da análise do percentual de gordura hepática e histopatologia, sendo caracterizado como esteatose leve. Pela peroxidação lipídica apresentou um maior acúmulo de MDA, porém um aumento de GSH. Contudo, a oferta dos respectivos óleos influenciou positivamente em diferentes mecanismos fisiológicos. / The Non-alcoholic fatty liver is related to the increasing causes of morbidity and mortality of liver diases. Its incidence is related to obesity and comorbidities linked to it, in which it has awaked great interest in the research. The disease is associated to genetic predisposition, lack of physical activity and high intake of saturated fats and fructose. Quantitative modulation of the diet may promote or retard the pathology. Thus, therapies aimed at delaying or decreasing non alcoholic hepatic steatosis could alleviate liver damage, improve liver function and reduce its progression. The objectives of the present study were: to evaluate the consumption of vegetable oils rich in commercially available MUFAs and PUFAs in the prevention or reduction of hepatic steatosis by analyzing parameters of hepatic and serum lipid metabolism, oxidative stress and delaying the progression of NAFLD. Material and Methods: animals were divided into the following groups: Control (n = 10) + HLF * (n = 10); Group HLF * AZ (n = 10); Group HLF * CN (n = 10); Group HLF * S (n = 10). After 16 weeks of diet and treatment with the respective oils, the animals were anesthetized and blood was withdrawn by cardiac puncture and tissues for further analysis. Results: The supply of a diet rich in saturated fat (lard) + fructose caused an increase in weight in the HLF group while the administration of the respective vegetable oils was able to delay the weight gain. Liver weight and sum of epididymal and retroperitoneal adipose tissues were higher in HLF while there was a significant reduction in HLF / S hepatic weight. Retroperitoneal tissue was lower in HLF / CN. In general, treatment with the respective vegetable oils decreases steatosis in all experimental groups. The supply of extra virgin olive oil did not reflect weight gain, but the group had a significant increase in serum TG and VLDL, with a decrease in serum cholesterol. Histologically it reduced the steatosis score when compared to the HLF being classified as mild to moderate macro and microvesicular steatosis. Soybean oil presented a higher amount of PUFAs, being rich in n-6, reflected in the maintenance of animal weight, decreased steatosis, being classified as mild steatosis when compared to HLF, but increased serum cholesterol. He presented an increase of MDA and decrease of hepatic GSH. Canola oil due to its content of PUFAs (n-6 and n-3) had greater incorporation of EPA and DHA than appear to have been positively evidenced. There was no alteration in the biochemical parameters and presented lower accumulation of liver fat through the analysis of the percentage of liver fat and histopathology, being characterized as mild steatosis. By the lipid peroxidation presented a greater accumulation of MDA, but an increase of GSH. However, the supply of the respective oils had a positive influence on different physiological mechanisms.
16

Genetic polymorphisms in the stearoyl-CoA desaturase1 (SCD1) gene and their influence on the conjugated linoleic acid (CLA) and monounsaturated fatty acids (MUFA) content of milk fat of Canadian Holstein and Jersey cows

Kgwatalala, Patrick M., 1973- January 2008 (has links)
Stearoyl-CoA desaturase1 (SCD1) catalyzes the synthesis of conjugated linoleic acid (CLA) and mono-unsaturated fatty acids (MUFA) in the mammary gland of ruminant animals. We hypothesized that single nucleotide polymorphisms (SNPs) in the coding region, 5' and 3' untranslted regions (UTRs) of the SCD1 gene would influence the activity of SCD1 enzyme and consequently account for some within-breed variations in milk CLA and MUFA. Sequence analysis of the coding region of the SCD1 gene of Jerseys and Holsteins revealed c.702A→G, c.762T→C and c.878C→T SNPs in exon 5 in both breeds and c.435G→A in exon 3 in Holsteins. The SNPs resulted in: A (G435A702T 762C878), A1 (A435A702T 762C878), B (G435G702C 762T878) and B1 (A435G702C 762T878) coding variants in Holsteins and only variants A and B in Jerseys. Only SNP 878C→T resulted in a non-synonymous codon change resulting in p.293Ala and p.293Val protein variants or alleles at the SCD1 locus. Subsequent association studies found significantly higher C10 index, C12 index and C14 index and consequently higher concentrations of C10:1 and C12:1 in p.293AA cows compared to the p.293VV cows in both breeds. The SCD1 genotype had no influence on concentrations of C141, C16:1, C18:1 and CLA in both breeds. / Sequence analysis of the 5' and 3' UTRs revealed no SNPs in the 5'UTR and a total of 14 SNPs in the 3'UTR of both breeds. The SNPs were in complete linkage disequilibrium resulting in 3 haplotypes or regulatory variants: H1 (G1571G1644C1763C2053A2584 A3007C3107G3208 T3290G 3497G3682A4399C4533G4881), H2 (G1571G1644A1763C2053A 2584G3007 C3107G3208T3290G3497G 3682A4399C4533G4881) and H3 (T 1571C1644A1763 T2053G2584G3007T 3107A3208C3290A3497A3682T 4399T4533A4881) in Holsteins and only H1 and H3 variants in Jerseys. A subsequent association study involving 862 Holstein cows, found the H1 regulatory variant to be associated with higher C10 and C12 desaturase indices and consequently with higher concentrations of C10:1 and C12:1 compared with the H3 variant. The effects of the H2 variant were intermediate to those of H1 and H3. 3'UTR genotype had no influence on the concentrations of C14:1, C16:1, C18:1 and CLA. The concentrations of C10:1 and C12:1 in milk fat could therefore be due to effects of SNPs in the open reading frame and the 3'UTR regions of the SCD1 gene. These results indicate that SNPs in the coding and 3'UTR regions of the SCD1 gene could be used as markers for genetic selection for increased C10:1 and C12:1 contents of milk.
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Efeitos dos diferentes ácidos graxos no metabolismo lipídico e estresse oxidativo em camundongos C57/BL alimentados com dieta hiperlipídica e rica em frutose / Effects of different fatty acids on lipid metabolism and oxidative stress in C57/BL mice fed a high fat diet and rich in fructose

Camila Sanches Manca 30 June 2017 (has links)
A esteatose hepática não alcóolica está relacionada às causas crescentes de morbimortalidade de doenças hepáticas. Sua incidência está relacionada à obesidade e comorbidades vinculadas a esta, na qual tem despertado grande interesse na pesquisa. A modulação quantitativa da dieta pode promover ou retardar a patologia. Desta forma, terapias voltadas para retardar ou diminuir a esteatose hepática não alcóolica poderiam atenuar o dano hepático, melhorar a função hepática e reduzir sua progressão. Os objetivos do presente estudo foram: avaliar o consumo de óleos vegetais ricos em MUFAs e PUFAs usados comercialmente na prevenção ou redução da esteatose hepática analisando parâmetros do metabolismo lipídico hepático e sérico, estresse oxidativo e retardando a progressão de NAFLD. Material e Métodos: os animais foram divididos nos seguintes grupos: Controle (n=10) + HLF * (n=10); Grupo HLF * AZ (n=10); Grupo HLF* CN (n=10); Grupo HLF* S (n=10). Após 16 semanas de dieta e tratamento com os respectivos óleos, os animais foram anestesiados e o sangue retirado por punção cardíaca e os tecidos para as análises posteriores. Resultados: A oferta de uma dieta rica em gordura saturada (banha) + frutose ocasionou um aumento do peso no grupo HLF enquanto a administração dos respectivos óleos vegetais foi capaz de retardar o ganho de peso. O peso hepático e da soma dos tecidos adiposos epididimal e retroperitonial foi maior no HLF enquanto houve redução significativa no peso hepático HLF/S. O tecido retroperitonial foi menor no HLF/CN. De uma maneira geral o tratamento com os respectivos óleos vegetais diminui a esteatose em todos os grupos experimentais. A oferta de azeite extra virgem não refletiu no ganho de peso, porém o grupo teve um aumento significativo de TG e VLDL séricos, com diminuição do colesterol sérico. Avaliado histologicamente diminuiu o score de esteatose quando comparado ao HLF sendo classificado como esteatose macro e microvesicular de leve a moderada. O óleo de soja apresentou uma maior quantidade de PUFAs, sendo rico em n-6, refletiu na manutenção do peso dos animais, diminuiu a esteatose, sendo classificado como esteatatose leve, quando comparado ao HLF, porém aumentou o colesterol sérico. Apresentou um aumento de MDA e diminuição de GSH hepático. O óleo de canola devido a seu teor em ácidos graxos PUFAs (n-6 e n-3) teve maior incorporação do EPA e DHA que parecem ter evidenciado positivamente. Não apresentou alteração nos parâmetros bioquímicos e apresentou menor acúmulo de gordura hepática através da análise do percentual de gordura hepática e histopatologia, sendo caracterizado como esteatose leve. Pela peroxidação lipídica apresentou um maior acúmulo de MDA, porém um aumento de GSH. Contudo, a oferta dos respectivos óleos influenciou positivamente em diferentes mecanismos fisiológicos. / The Non-alcoholic fatty liver is related to the increasing causes of morbidity and mortality of liver diases. Its incidence is related to obesity and comorbidities linked to it, in which it has awaked great interest in the research. The disease is associated to genetic predisposition, lack of physical activity and high intake of saturated fats and fructose. Quantitative modulation of the diet may promote or retard the pathology. Thus, therapies aimed at delaying or decreasing non alcoholic hepatic steatosis could alleviate liver damage, improve liver function and reduce its progression. The objectives of the present study were: to evaluate the consumption of vegetable oils rich in commercially available MUFAs and PUFAs in the prevention or reduction of hepatic steatosis by analyzing parameters of hepatic and serum lipid metabolism, oxidative stress and delaying the progression of NAFLD. Material and Methods: animals were divided into the following groups: Control (n = 10) + HLF * (n = 10); Group HLF * AZ (n = 10); Group HLF * CN (n = 10); Group HLF * S (n = 10). After 16 weeks of diet and treatment with the respective oils, the animals were anesthetized and blood was withdrawn by cardiac puncture and tissues for further analysis. Results: The supply of a diet rich in saturated fat (lard) + fructose caused an increase in weight in the HLF group while the administration of the respective vegetable oils was able to delay the weight gain. Liver weight and sum of epididymal and retroperitoneal adipose tissues were higher in HLF while there was a significant reduction in HLF / S hepatic weight. Retroperitoneal tissue was lower in HLF / CN. In general, treatment with the respective vegetable oils decreases steatosis in all experimental groups. The supply of extra virgin olive oil did not reflect weight gain, but the group had a significant increase in serum TG and VLDL, with a decrease in serum cholesterol. Histologically it reduced the steatosis score when compared to the HLF being classified as mild to moderate macro and microvesicular steatosis. Soybean oil presented a higher amount of PUFAs, being rich in n-6, reflected in the maintenance of animal weight, decreased steatosis, being classified as mild steatosis when compared to HLF, but increased serum cholesterol. He presented an increase of MDA and decrease of hepatic GSH. Canola oil due to its content of PUFAs (n-6 and n-3) had greater incorporation of EPA and DHA than appear to have been positively evidenced. There was no alteration in the biochemical parameters and presented lower accumulation of liver fat through the analysis of the percentage of liver fat and histopathology, being characterized as mild steatosis. By the lipid peroxidation presented a greater accumulation of MDA, but an increase of GSH. However, the supply of the respective oils had a positive influence on different physiological mechanisms.
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Investigations of lipophilic bioactive dietary components to improve aspects of metabolic dysregulation in mice

Snoke, Deena B. January 2020 (has links)
No description available.
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Genetic polymorphisms in the stearoyl-CoA desaturase1 (SCD1) gene and their influence on the conjugated linoleic acid (CLA) and monounsaturated fatty acids (MUFA) content of milk fat of Canadian Holstein and Jersey cows

Kgwatalala, Patrick M., 1973- January 2008 (has links)
No description available.
20

Fractionnement par cristallisation extractive à froid des acides gras libres et des triglycérides de l'huile de Nephelium Lappaceum L. (Ramboutan) : oxygénation et enrichissement en acides gras particuliers / New crystallization separation and densification processes of saturated and monounsaturated fatty acids by gelation / degelling of saturated fatty acids and allylic hydroperoxidation of monounsaturated fatty acids of Nephelium Lappaceum L. oil (Rambutan)

Douniama-Lonn, Gré Véronique 17 November 2018 (has links)
Dans cette étude, les fruits du Nephelium Lappaceum L. (ramboutan) ont été récoltés en Mars 2015 à Boko, dans la zone sud de la République du Congo. Plante à graines oléagineuses avec un noyau riche en huile (36 %), particulièrement composée d’acides gras saturés et monoinsaturés à longues chaines : C16:0 4,84 %, C18:0 5,48 %, C18:1 45,62 %, C18:2 2,70 %, C20:0 26,53 %, C20:1 9,27 % et C22:0 2,64 %. L’huile de ramboutan a été hydrolysée par voie enzymatique en présence de lipase Candida rugosa, les acides gras libres sont obtenus avec un ratio acides gras saturés (AGS)/acides gras monoinsaturés (AGI) de 0,67. La disponibilité des acides gras saturés et monoinsaturés des familles en C20 et C22 a stimulé nos investigations vers l’élaboration des shortenings et biotensioactifs à haut point de fusion. Deux stratégies ont été mises en place à partir des concentrats en acides gras libres issus de l’hydrolyse enzymatique de l’huile de ramboutan en présence de lipase de Candida rugosa. La première a consisté à la cristallisation à froid des acides gras saturés par la technologie de gélification/dégélification. On observe à l’issu de ce procédé une séparation physique du mélange d’acides gras en deux fractions. Une étude thermique des fractions solide et fluide a été effectuée et a montré que les AGS (To = 15, 86 °C ; Tf = 18,49 °C) refroidissent plus vite, mais fondent moins vite que les AGI (To = -19, 46 °C, Tf= 3,87 °C). Les teneurs des AGI passent de 55,6 % après hydrolyse à 63,53 % dans la fraction fluide et celles des AGS passent de 39,1 % après hydrolyse à 45,13 %. Les résultats de la SFC indique une teneur en AGS de 25,98 % dans la fraction fluide mais de 38,24 % dans la fraction solide ; Et le rendement massique de la fraction fluide passent de 16% à 55 % et de 84 % à 45 % respectivement de la fraction fluide et la fraction solide. La deuxième stratégie a consisté à réaliser l'insertion allylique de l'oxygène singulet dans les acides gras libres monoinsaturés à longues chaines C18:1 et C20:1. Elle est réalisée dans un milieu émulsionné constitué d'un système multiphase NaOH/H2O2/Na2MoO4. Le produit de réaction, au moyen de la GC, montre la présence des acides gras non conventionnels, deux isomères d’hydroperoxydes d’acides gras respectifs de chaque AGMI (C18:1 et C20:1) de conformation trans. Il en résulte une augmentation de la teneur en acides gras saturés à longues chaines C20: 0 (26,21% à 56,46%) et C22 (2,48 % à 3,77 %). Le produit de cette réaction présente un ratio AGS/ AGT (acides gras totaux): 0,82. La valorisation séquencée des acides gras de l'huile de noyau de ramboutan permet de proposer deux plateformes de biomolécules shortenings à haut point de fusion: Une plateforme de composition bien définie en acides gras saturés C20:0 et C22:0 et une autre constituée par un bulk en acides gras saturés C20:0-C22:0 et acides gras insaturés monohydroxyperoxydés trans. Les investigations sur l'hydroperoxydation des acides gras insaturés ont révélé un intérêt particulier sur l'impact du radical hydroxy peroxyde sur le mouvement de la configuration trans et cis dans ces acides gras modifiés en présence de glycidol en monoesters de glycérol et d'acides gras hydroxy peroxydes insaturés cis. C'est une autre plateforme de synthèse originale de biotensioactifs hydroxy peroxydes insaturés cis nouveaux qu'offre la valorisation séquencée des concentrats d'acides gras insaturés de l'huile de ramboutan. / In this study, the fruits of Nephelium Lappaceum L. (Rambutan) were harvested in Boko, in the southern area of the Republic of Congo. Oilseed plant with an oil-rich core (36 %), particularly composed of long chain fatty acids: C16:0 4.84 %, C18:0 5.48 %, C18:1 45.62 %, C18:2 2.70 %, C20:0 26.53 %, C20:1 9.27 % and C22:0 2.64 %. Rambutan oil was hydrolyzed enzymatically in the presence of lipase Candida rugosa, the free fatty acids are obtained with a ratio of saturated fatty acids (AGS)/monounsaturated (AGI) of 0.67. The availability of saturated and monounsaturated fatty acids of the C20 and C22 families stimulated our investigations towards the development of shortenings and biotensioactives with a high melting point. Two strategies have been implemented using free fatty acid concentrates derived from the enzymatic hydrolysis of rambutan oil in the presence of Candida rugosa lipase. The first was to achieve the cold crystallization of saturated fatty acids by gelation / defrosting technology. At the end of this process, a physical separation of the fatty acid mixture into two fractions is observed. A thermal study of the solid and fluid fractions was carried out and showed that the AGS (To = 15, 86 °C, Tf = 18.49 °C) cool faster, but melt slower than the AGI (To = -19 46 °C, mp = 3.87 °C). The contents go from 55.6% after hydrolysis to 63.53 % of AGI in the fluid fraction and 39.1 % after hydrolysis to 45.13 % of AGS. The results of the SFC indicate an AGS content of 25.98 % in the fluid fraction but of 38.24 % in the solid fraction ; And the mass yield of 16 % to 55 % and 84 % to 45 % respectively of the fluid fraction (enriched in AGI, in particular in MUFA) and the solid fraction (enriched with AGS). The second strategy was to perform the allyl insertion of singlet oxygen in long-chain monounsaturated free fatty acids C18:1 and C20:1, carried out in an emulsified medium consisting of a multiphase NaOH / H2O2/Na2MoO4 system. The reaction product, using GC, shows the presence of unconventional fatty acids, two isomers of respective fatty acid hydroperoxides of each trans-conforming MUFA (C18:1 and C20:1) and an increase in saturated fatty acids content with long chain C20:0 (26.21 % to 56.46 %) and C22:0 (2.48 % to 3.77 %). The product of this reaction has an AGS/AGT ratio of 0.82. The sequential evaluation of the fatty acids of the Ramboutan core oil makes it possible to propose two platforms of biomolecules shortenings with a high melting point: A platform with a well defined composition of saturated fatty acids C20:0 and C22:0 and another constituted by a bulk of C20:0-C22:0 saturated fatty acids and transmonohydroxyperoxide trans unsaturated fatty acids. Investigations on the hydroperoxidation of unsaturated fatty acids have revealed a particular interest on the impact of hydroxyperoxide radical on the movement of the trans and cis configuration in these fatty acids modified in the presence of glycidol in monoesters of glycerol and hydroxyperoxide fatty acids unsaturated cis. This is another novel synthesis platform of new cis-unsaturated hydroxyperoxyd biotensiatives offered by the sequenced recovery of unsaturated fatty acid concentrates from rambutan oil.

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