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Effects of Sleep Apnea on Nocturnal Free Fatty Acids in Subjects with Heart Failure

JUN, Jonathan C.; DRAGER, Luciano F.; NAJJAR, Samer S.; GOTTLIEB, Stephen S.; BROWN, Cynthia D.; SMITH, Philip L.; SCHWARTZ, Alan R.; POLOTSKY, Vsevolod Y.
Fonte: AMER ACAD SLEEP MEDICINE Publicador: AMER ACAD SLEEP MEDICINE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Study Objectives: Sleep apnea is common in patients with congestive heart failure, and may contribute to the progression of underlying heart diseae. Cardiovascular and metabolic complications of sleep apnea have been attributed to intermittent hypoxia. Elevated free fatty acids (FFA) are also associated with the progression of metabolic, vascular, and cardiac dysfunction. The objective of this study was to determine the effect of intermittent hypoxia on FFA levels during sleep in patients with heart failure. Design and interventions: During sleep, frequent blood samples were examined for FFA in patients with stable heart (ejection fraction < 40%). In patients with severe sleep apnea (apnea-hypopnea index = 15.4 +/- 3.7 events/h; average low SpO(2) = 93.6%). In patients with severe sleep apnea, supplemental oxygen at 2-4 liters/min was administered on a subsequent night to eliminate hypoxemia. Measurements and Results: Prior to sleep onset, controls and patients with severe apnea exhibited a similar FFA level. After sleep onset, patients with severe sleep apnea exhibited a marked and rapid increase in FFA relative to control subjects. This increase persisted throughout NREM and REM sleep exceeding serum FFA levels in control subjects by 0.134 mmol/L (P = 0.0038) Supplemental oxygen normalized the FFA profile without affecting sleep architecture or respiratory arousal frequency. Conclusion: In patients with heart failure...

Proton flux induced by free fatty acids across phospholipid bilayers: New evidences based on short-circuit measurements in planar lipid membranes

ARCISIO-MIRANDA, Manoel; ABDULKADER, Fernando; BRUNALDI, Kellen; CURI, Rui; PROCOPIO, Joaquim
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
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Free fatty acids (FFA) are important mediators of proton transport across membranes. However, information concerning the influence of the Structural features of both FFA and the membrane environment on the proton translocation mechanisms across phospholipid membranes is relatively scant. The effects of FFA chain length, unsaturation and membrane composition on proton transport have been addressed in this study by means of electrical measurements in planar lipid bilayers. Proton conductance (G(H)(+)) was calculated from open-circuit voltage and short-circuit current density measurements. We found that cis-unsaturated FFA caused a more pronounced effect on proton transport as compared to Saturated and trans-unsaturated FFA. Cholesterol and cardiolipin decreased membrane leak conductance. Cardiolipin also decreased proton conductance. These effects indicate a dual modulation of protein-independent proton transport by FFA: through a flip-flop mechanism and by modifying a proton diffusional pathway. Moreover the membrane phospholipid composition was shown to importantly affect both processes. (C) 2009 Elsevier Inc. All rights reserved.; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); National Council for Scientific and Technological Development (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); State of Sao Paulo Research Foundation (FAPESP)

Efeitos elétricos de ácidos graxos livres em bicamadas lipídicas planas.; Electrical effects of free fatty acids in planar lipid bilayers.

Miranda Filho, Manoel de Arcisio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/08/2007 PT
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Ácidos graxos livres (FFA) são importantes mediadores do transporte de prótons através de membranas. Porém, pouco se sabe sobre a influência estrutural tanto dos FFA como do ambiente lipídico na translocação de prótons através de membranas. Tanto os efeitos do comprimento da cadeia e número de insaturações dos FFA como a composição da membrana foram analisados por medidas elétricas em bicamadas lipídicas planas. Condutância a prótons (GH+) e condutância de vazamento (Gleak) foram calculadas a partir de medidas de voltagem em circuito aberto e de corrente de curto-circuito obtidas através de um eletrômetro ou um amplificador de patch-clamp (modo de voltage-clamp). Nossos resultados mostram que FFA com cis-insaturações causam um efeito mais pronunciado no transporte de próton quando comparados com FFA saturados ou trans-insaturação. Colesterol e cardiolipina diminuem Gleak de membranas. Cardiolipina também diminui GH+. Esses efeitos indicam uma dupla modulação do transporte de prótons: pelo mecanismo de flip-flop dos FFA e por uma via difusional simples adicional.; Free fatty acids (FFA) are important mediatiors of proton transport across membranes. However, little is known about the structural influence of both FFA and the membrane environment have in proton translocation across phospholipid membranes and by which means this influence is brought about. Both the effects of FFA chain length and insaturation and membrane composition on proton transport have been addressed in this study by electrical measurements in planar lipid bilayers. Proton conductance (GH+) and leak conductance (Gleak) were calculated from open-circuit voltage and short-circuit current measurements obtained using either an electrometer or a patch-clamp amplifier (voltage-clamp mode). We found that cis-unsaturated FFA caused a more pronounced effect on proton transport as compared to saturated or trans-unsaturated FFA. Cholesterol and cardiolipin decreased Gleak. Cardiolipin also decreased GH+. These effects indicate a dual modulation of protein-independent proton transport by FFA through flip-flop and by an additional simple diffusional pathway.

Determinação de caseína e ácidos graxos livres em leite cru bovino; Determination of casein and free fatty acids in raw bovine milk

Meduri, Beatriz
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/12/2011 PT
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1000.0588%
A caseína e os ácidos graxos livres (AGL) são importantes componentes do leite relacionados às suas características industriais e sensoriais. Alguns fatores são responsáveis por alterações em suas concentrações, dentre eles, pode-se destacar as condições de armazenamento, além da agitação e, principalmente, a contagem de células somáticas (CCS). Para estudar tais alterações, avaliou-se através do presente estudo o efeito da temperatura de armazenamento (- 20oC e 7oC) e da idade das amostras (3, 6, 9 e 12 dias), assim como da CCS (CCS1: 400 mil, CCS2:400-750 mil e CCS3: 750 mil células somáticas/mL de leite). O efeito das condições de armazenamento sobre a caseína e os AGL foi avaliado no primeiro estudo. O efeito da CCS sobre a caseína e os AGL, por outro lado, foi avaliado no segundo estudo. No primeiro estudo, observou-se aumento nos teores de AGL ao longo do tempo, ou seja, acompanhando o aumento do período de armazenamento, com médias superiores em amostras resfriadas (7oC), em relação às congeladas (-20oC). Desta forma, sugere-se que análises laboratoriais devem ser realizadas em até três dias para este componente, devido ao seu aumento progressivo em amostras resfriadas. Para a caseína, entretanto...

Efeito comparativo de repositores energéticos sobre as concentrações plasmáticas de glicose e ácidos graxos livres de corredores de longa distância; Comparative effects of energetic repositors on plasma free-fatty acids and glucose of long distance runners

Ribeiro, Beatriz Gonçalves
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/08/2004 PT
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1000.0588%
A reposição de glicogênio pós treino foi investigada usando uma mistura de ambos, glicose e glicose-frutose, como repositores, em atletas corredores de longa distância. Dez corredores competitivos (30±4,7 anos) foram avaliados para composição corporal e consumo alimentar antes do exercício de 90 minutos em esteira elétrica a 70% V02máx. Amostras de sangue venoso foram coletadas antes e após o término do exercício, quando eles receberam 1g de carboidrato.kg-1 de uma mistura de ambos, glicose-frutose (CHO1) e glicose (CHO2), e outra com sucralose ou placebo (controle). Amostras de sangue foram retiradas 30, 60, 90 e 120 minutos após o consumo dos suplementos e usadas para determinação de glicose e de ácidos graxos plasmáticos, por reações colorimétricas. Não foram observadas diferenças significativas na composição corporal e na hidratação durante o exercício. Os tratamentos CHO1 e CHO2 produziram elevação na glicemia, em 30 minutos, comparados ao grupo placebo. Entretanto, em 90 min, somente no tratamento CHO1, uma queda na glicemia foi observada (CHO2>CHO1). Os ácidos graxos livres aumentaram comparativamente após o exercício (CHO1=CHO2=placebo) e, diferente do placebo, em 90 minutos, reduziram nos tratamentos CHO1 e CHO2. Ambos os repositores atuaram similarmente nas concentrações de ácidos graxos livres...

Cloreto de cobre como novo catalisador na esterificação de ácidos graxos; Copper chloride as catalyst in the esterification of free fatty acids

França, Mírian Cotrim
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/04/2013 PT
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Para uma produção eficiente e economicamente viável de ésteres é necessária a utilização de catalisadores durante o processo, uma vez que a transesterificação e a esterificação são reações de equilíbrio, sendo necessário deslocar o equilíbrio de reação na direção desejada. Nesse trabalho, ésteres metílicos e etílicos de ácidos graxos de cadeia longa foram produzidos usando cloretos de cobre como catalisadores. Para definir a melhor condição reacional, foram estudadas três diferentes razões em massa de AGLs de dendê/ metanol (ou etanol) / catalisador. Definida a melhor condição reacional, foram produzidos monoésteres metílicos e etílicos a partir de ácidos graxos livres do destilado da soja assim como das borras do refino correspondente do óleo de soja e de dendê. Os ésteres metílicos e etílicos foram caracterizados através das técnicas de cromatografia gasosa acoplada à espectrometria de massas (CG/MS) e ressonância magnética nuclear de prótons (RMN 1H). Observou-se que as reações empregando cloreto de cobre como catalisador reagem preferencialmente com AGLs em relação aos triésteres. Dentre esses ácidos graxos livres, os de cadeia insaturada, são os que reagem mais facilmente com o catalisador. Em relação ao álcool empregado...

Effects of acute cold exposure on rectal temperature, blood glucose and plasma free fatty acids in alloxan-diabetic rats

Macari, Marcos; Ferro, J. A.; Eizirik, D. L.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 63-65
ENG
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These experiments were carried out to study the effects of acute cold exposure (0-2°C/4 hr) on rectal temperature, blood glucose and plasma free fatty acids (FFA) in alloxan-diabetic rats. Male Wistar rats weighing 170-190 g were used and diabetes was induced by i.v. alloxan injection (40 mg/kg body wt). Cold exposure produced severe hypothermia in diabetic rats. After 4 hr of cold, blood glucose of diabetic rats was reduced from 296±16 to 86t±12 mg/dl (P<0.01), and FFA increased slightly, but was not statistically different (P>0.05) from the initial value. As expected, interscapular brown adipose tissue (IBAT) and retroperitoneal and epididymal white adipose tissues were significantly lower in diabetic than in control rats. Cold exposure reduced total IBAT lipids in control but not in diabetic animals. The results of this experiment suggest that diabetic rats were unable to maintain body temperature in the cold, probably because of a failure to generate an adequate amount of heat by nonshivering thermogenesis in brown adipose tissue.

Recuperação de acidos graxos livres em resina de troca ionica.; Recuperation of free fatty acids in ion exchange resins.

Erika Cristina Cren
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/03/2005 PT
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Alguns óleos vegetais são sensíveis às condições drásticas do processo de refino, físico ou químico, podendo apresentar problemas ao serem submetidos a estes processos, tais como perda de substâncias desejáveis, como os nutracêuticos, escurecimento do óleo, além de perdas elevadas de óleo neutro. A extração líquido-líquido vem sendo estudada como alternativa aos métodos tradicionais de desacidificação destes óleos, pois utiliza condições brandas de processo, mas apresenta como desvantagem a necessidade de recuperação do solvente usado para a desacidificação, para sua futura reutilização. Resinas de troca iônica podem ser utilizadas como complemento da extração liquido-liquido, permitindo separar na corrente de extrato os ácidos graxos livres extraídos do solvente utilizado na extração, de forma a recuperá-lo. Ambos os processos se complementam, pois atingem os mesmos objetivos de mínima demanda de energia e mínima perda de óleo neutro, além de potencialmente poderem reduzir a perda de nutracêuticos em alguns óleos, já que utilizam condições mais brandas de processo se comparado a métodos de desacidificação convencionais. Este trabalho estudou o comportamento de equilíbrio e cinético de troca iônica em batelada para a separação dos ácidos graxos livres de um sistema modelo contendo ácido oléico + etanol...

Estudo sobre o uso do resíduo da etapa de deceragem de óleo de farelo de arroz para a produção de ácidos graxos e álcoois graxos; Study of the use of the dewaxing step residue of rice bran oil to produce fatty acids and fatty alcohols

Kelly Lendini Troni
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/06/2013 PT
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A cera do óleo de farelo de arroz (OFA) é um resíduo da etapa de deceragem no processo de refino de óleos. Tradicionalmente, as ceras naturais, que em excesso geram turbidez no óleo vegetal embalado, são removidas por cristalização e filtração a baixa temperatura. Esse resíduo da etapa de deceragem pode conter de 20 a 80% em massa de óleo, seguido por uma fração principal de ceras, álcoois graxos livres, ácidos graxos livres e hidrocarbonetos. A fração de cera do resíduo é constituída por álcoois graxos e ácidos graxos de cadeia longos esterificados (mais de 18 carbonos). Considerando que o óleo de farelo de arroz tem 4-6% em massa de cera, uma grande quantidade dessa fonte natural de compostos graxos é subaproveitada na indústria de óleos vegetais. De acordo com a revisão bibliográfica, nenhum trabalho na literatura trata da produção de ácidos graxos e de álcoois graxos a partir da hidrólise do resíduo extraído da etapa de deceragem usando vapor supersaturado (elevadas temperaturas e alto vácuo). Nestas condições, a reação de degradação de ceras, ou de desesterificação, ocorre sem a presença de catalisadores em um meio graxo. Diante do exposto, esta dissertação de mestrado teve por objetivo o estudo inédito de aplicação das mesmas condições da desacidificação por via física como rota na produção de ácidos graxos e álcoois graxos a partir do resíduo da etapa de deceragem de óleo de farelo de arroz...

Goat milk free fatty acid characterization during conventional and ohmic heating pasteurization

Pereira, Ricardo; Martins, Rui C.; Vicente, A. A.
Fonte: American Dairy Science Association Publicador: American Dairy Science Association
Tipo: Artigo de Revista Científica
Publicado em /08/2008 ENG
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The disruption of the milk fat globule membrane can lead to an excessive accumulation of free fatty acids in milk, which is frequently associated with the appearance of rancid flavors. Solid-phase microextraction and gas chromatography techniques have been shown to be useful tools in the quantification of individual free fatty acids in dairy products providing enough sensitivity to detect levels of rancidity in milk. Therefore, the aim of this study was to characterize the short-chain and medium-chain free fatty acid profile in i) raw untreated goat milk; ii) raw goat milk passing through pumps and heating units (plate-and-frame heat exchanger and ohmic heater); and iii) processed goat milk by conventional and ohmic pasteurization to determine the influence of each treatment in the final quality of the milk. Multivariate statistical analysis has shown that the treatments studied were not responsible for the variability found on free fatty acid contents. In particular, it was possible to conclude that ohmic pasteurization at 72°C for 15 s did not promote an extended modification of free fatty acid contents in goat milk when compared with that of conventional pasteurization. Furthermore, principal component analysis showed that the capric acid can be used to discriminate goat’s milk with different free fatty acid concentrations. Hierarchical cluster analysis showed evidence of the existence of correlations between contents of short and medium chain free fatty acids in goat milk.

Optimization of pretreatment of jatropha oil with high free fatty acids for biodiesel production

Suwito, Supriyono; Dragone, Giuliano; Sulistyo, Hary; Murachman, Bardi; Purwono, Suryo; Teixeira, J. A.
Fonte: SP Higher Education Press Publicador: SP Higher Education Press
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
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A central composite rotatable design and response surface methodology were used in order to investigate the individual and combined effects of the ethanol-to-oil ratio, H2SO4 concentration, temperature and time of reaction on the reduction of free fatty acid (FFA) in jatropha oil. A quadratic polynomial model relating the reaction variables with FFA reduction was developed, presenting a good coefficient of determination (R2= 0.893). For reducing FFA to less than 1%, the optimal combination was found to be 0.62 v$v–1 ethanol-to-oil ratio (14.9 v$v–1 ethanol-to-FFA ratio), 1.7% v$v–1 H2SO4 concentration,and 79 min reaction time at a reaction temperature of 54°C. These results are of great relevance to maximize methyl esters formation by transesterification using an alkaline catalyst.; Fundação para a Ciência Technology through G. Dragone grant SFRH/BPD/44935/2008. The authors acknowledge financial support from project INNOVALGAE (PTDC/AACAMB/108511/2008)

Esterification of free fatty acids with methanol using heteropolyacids immobilized on silica

Caetano, C; Fonseca, I; Ramos, A; Vital, J; Castanheiro, Jose
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
POR
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896.6939%
The esterification of palmitic acid with methanol was studied using tungstophosphoric acid (PW), molibdophosphoric acid (PMo) and tungstosilicic acid (SiW) immobilized by sol–gel technique on silica, at 60 º C. It was observed that the catalytic activity decreases in the series: PW-silica > SiW-silica > PMo-silica. A series of PW immobilized on silica with different PW loadings from 2.5 wt.% to 8.4 wt.% were prepared. It was observed that the PW-silica2 (with 4.2 wt.%) shows the highest catalytic activity on esterification of palmitic acid with methanol. Catalytic stability of the PW-silica2 was evaluated by performing consecutive batch runs with the same catalyst sample. After the second batch it was observed a stabilisation of the initial activity. In order to study the heteropolyacid lixiviation, a posterior catalytic experiment was carried out. The PW-silica2 was put in contact with methanol, without palmitic acid, during 72 h. After this period, the catalyst was separated from methanol by centrifugation, and the palmitic acid was added to the reaction mixture. It was observed that the reaction only occurs in the heterogeneous phase. The PW-silica2 was also used as catalyst in esterification of others fatty acids: oleic and stearic acid. It was also observed a good catalytic activity of PW-silica2 for the different substrates used in the esterifications.

Esterification of free fatty acids over chitosan with sulfonic acid groups

Caetano, CS; Caiado, M; Ramos, A; Fonseca, I; Vital, J; Castanheiro, J
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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Chitosan, which is an abundant biopolymer, with sulfonic acid groups was used as an efficient, environmentally friendly heterogeneous catalyst for the esterification of free fatty acids with methanol into their more fatty acid methyl ester. Sulfonic acid catalysts supported on chitosan have been studied in the esterification of palmitic acid with methanol at 60 C. The sulfonic acid groups were introduced onto chitosan (CT) through cross-linking with sulfosuccinic acid (SSA). The catalytic activity increased as the amount of sulfonic acid groups present in chitosan was increased. However, with large amounts of sulfonic acid groups, the catalytic activity decreased. This behaviour can be explained by the factors that limit the diffusion. The catalytic stability of the CT4 (2.08 mmol sulfonic acid groups/g) sample was evaluated through consecutive batch runs performed with the same catalyst sample. After the second batch, the catalytic activity stabilised. The CT4 catalyst was also used as a catalyst in the esterification of oleic and stearic acids with methanol. A good catalytic activity of CT4 for the different substrates used in the esterifications was observed.

Free Fatty Acids and Their Metabolism Affect Function and Survival of Podocytes

Sieber, Jonas; Jehle, Andreas Werner
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
EN_US
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Podocyte injury and loss critically contribute to the pathogenesis of proteinuric kidney diseases including diabetic nephropathy. Deregulated lipid metabolism with disturbed free fatty acid (FFA) metabolism is a characteristic of metabolically unhealthy obesity and type 2 diabetes and likely contributes to end-stage kidney disease irrespective of the underlying kidney disease. In the current review, we summarize recent findings related to FFAs and altered renal FFA metabolism with a special focus on podocytes. We will outline the opposing effects of saturated and monounsaturated FFAs and a particular emphasis will be given to the underlying molecular mechanisms involving insulin resistance and endoplasmic reticulum homeostasis. Finally, recent data suggesting a critical role of renal FFA metabolism to adapt to an altered lipid environment will be discussed.

Free fatty acids have more potent effects on gastric emptying, gut hormones, and appetite than triacylglycerides

Little, T.; Russo, A.; Meyer, J.; Horowitz, M.; Smyth, D.; Bellon, M.; Wishart, J.; Jones, K.; Feinle-Bisset, C.
Fonte: W B Saunders Co Publicador: W B Saunders Co
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
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896.6939%
BACKGROUND & AIMS: The effects of fat on gastric emptying (GE), gut hormones, and energy intake are dependent on digestion to free fatty acids (FFAs). In animals, small intestinal oleic acid inhibits energy intake more potently than the triacylglyceride (TG) triolein, but there is limited information about the comparative effects of FFA and TG in human beings. We compared the effects of FFA and TG on GE, gut hormone secretion, appetite, and energy intake in healthy males. METHODS: Nine men (age, 23 +/- 2 y; body mass index, 22 +/- 1 kg/m(2)) were studied on 3 occasions to evaluate the effects of (1) 40 g oleic acid (FFA, 1830 kJ), (2) 40 g macadamia oil (TG, 1856 kJ; both 600-mL oil-in-water emulsions stabilized with 4% milk protein and labeled with 15 MBq (123)I), or (3) 600 mL 4% milk protein (control, 352 kJ), administered intragastrically, on GE, plasma cholecystokinin (CCK) and peptide-YY (PYY) levels, appetite perceptions, and subsequent energy intake. RESULTS: GE of FFA was much slower than that of TG (P < .05), with greater retention of FFA, than TG, in the proximal stomach (P < .001). Hunger was less (P < .05), and fullness was greater (P < .05), after FFA when compared with control and TG. Increases in plasma CCK and PYY levels were greater after FFA than TG or control (P < .05). Energy intake tended to be less after FFA compared with TG (control...

The role of the free fatty acid, lauric acid, in appetite regulation and its potential as an appetite-suppressant.

Feltrin, Kate Lauren
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008
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The presence of nutrients, particularly fat, in the small intestine modulates gastrointestinal function and subsequent energy intake, and it is well established that the digestion of fat into free fatty acids is required for these effects to occur. Furthermore, the effects of fatty acids are dependent on their chain length. The research presented in this thesis relates to the effects of fatty acids, particularly lauric acid, on the regulation of gastrointestinal function and the suppression of energy intake. One of the first studies in humans to evaluate the effect of fatty acid chain length established that fatty acids with ≥ 12 carbon atoms slow gastric emptying, while fatty acids with ≤ 10 carbon atoms have no effect, indicating that there may be a separation in the effects of fatty acids occurring between those with ≤ 10 and ≥ 12 carbon atoms. More recent studies in humans have determined that there are marked differences in the effects of intraduodenal lauric acid, a saturated fatty acid with 12 carbon atoms (“C12”), and decanoic acid, a saturated fatty acid with 10 carbon atoms (“C10), on the modulation of gastrointestinal motility, hormone secretion and energy intake. For example, C12, but not C10, markedly suppresses energy intake...

Freie-Fettsäure-induzierte Apoptose und Proteinkinase C-Expressionsmuster in Endothel- und glatten Muskelzellen humaner Koronararterien; Free fatty acid-induced apoptosis and expression pattern of protein kinase C in endothelial (HCAEC) and smooth muscle cells (HCASMC) of human coronary arteries

Schatz, Ulrike
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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919.9184%
Fragestellung - Apoptose von vaskulären Endothel- und glatten Muskelzellen spielt bei der Pathogenese der Atherosklerose eine entscheidende Rolle. Da freie Fettsäuren in verschiedenen Zelltypen Apoptose induzieren, wurden die Effekte gesättigter und ungesättigter Fettsäuren auf die Apoptose von Endothel- und glatten Muskelzellen humaner Koronararterien untersucht. - Statine entfalten auch Cholesterin-unabhängige gefäßprotektive Wirkungen und können die Apoptose von Gefäßzellen sowohl erhöhen als auch erniedrigen. Deshalb wurde der Einfluss des Statins Atorvastatin auf die Lipoapoptose von Endothel- und glatten Muskelzellen humaner Koronar-arterien geprüft. - Um die mögliche Rolle der multifunktionalen Proteinkinase C (PKC) bei der Apoptose von Endothel- und glatten Muskelzellen humaner Koronararterien abzuklären, wurden das PKC-Expressionsmuster und die Effekte ver-schiedener Proteinkinase C-Inhibitoren untersucht. Material und Methodik - Apoptoseraten wurden durch Analyse des Zellzyklus (subG1-DNA-Gehalt) bestimmt. - PKC-Expressionsmuster wurden mit Isoform-spezifischen Antikörpern und Western Blots sowie mit Light Cycler PCR analysiert. - Intrazelluläre PKC-Verteilung wurde mit konfokaler Lasermikroskopie und Isoform-spezifischen Antikörpern ermittelt. Ergebnisse - In beiden Zelltypen induzierten die gesättigten Fettsäuren Palmitat (16:0) und Stearat (18:0) Apoptose...

Einfluss freier Fettsäuren auf die Insulinsekretion beim Menschen; Influence of free fatty acids on insulin secretion in humans

Steigenberger, Mirjam Elisabeth
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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Zu den pathophysiologischen Grundlagen des Diabetes mellitus Typ 2 gehören die Insulinresistenz und die gestörte Insulinsekretion. Ziel dieser Arbeit war es, zu untersuchen, ob der Spiegel der freien Fettsäuren im Nüchternplasma bei Risikopersonen für Diabetes mellitus Typ 2 die Insulinsekretion beeinträchtigt. Hierfür untersuchten wir in einer Querschnittsuntersuchung 1055 Probanden mit positiver Familienanamnese für Typ 2 Diabetes mellitus. Unabhängig von Alter, Geschlecht, Insulinsensitivität und prozentualem Fettgehalt des Körpers fanden wir in unserer multivariaten linearen Regressionsanalyse eine statistisch signifikante negative Korrelation (p<0,0001) der Konzentration nüchtern freier Fettsäuren mit der ersten Phase der Insulinsekretion. Dieser Befund bestätigt Hinweise aus früheren Studien. Aus bisher durchgeführten Studien ging jedoch nicht hervor, ob ein erhöhter Nüchternspiegel freier Fettsäuren die Entwicklung der ersten Phase der Glukose-induzierten Insulinsekretion beeinflusst oder voraussagen kann. Außerdem war bisher unklar inwiefern der Nüchternspiegel der freien Fettsäuren und die Änderung der ersten Phase der Glukose-induzierten Insulinsekretion durch eine Lebensstiländerung beeinflusst werden können. Zu diesem Zweck untersuchten wir bei 105 Probanden mit positiver Familienanamnese für Typ 2 Diabetes mellitus den Nüchternspiegel freier Fettsäuren und im Rahmen eines oralen Glukosetoleranztests die erste Phase der Insulinsekretion vor und nach einer 9-monatigen Lebensstilintervention. Außerdem wurden anthropometrische und metabolische Parameter erhoben...

Validation of a New Analytical Method for the Measurement of Free Fatty Acids in Biodiesel

FIGUEIREDO, Elizabeth da Silva; VIEIRA, Eduardo de Castro; CAVALCANTI, Eduardo Homem de Siqueira; D´ELIA, Eliane
Fonte: Instituto Nacional de Tecnologia Publicador: Instituto Nacional de Tecnologia
Tipo: Artigo de Revista Científica
EN
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905.6849%
Electroanalysis 2013, 25, No. 3, 750 – 756; International and Brazilian standards have in common the acid number as the main qualification parameter for biodiesel. Free fatty acids lead to engine corrosion and contribute to the formation of gum. The analytical methods specified for analysis are based on colorimetric and potentiometric titrations, which are characterised by lack of selectivity. This article proposes a new method based on the electrochemical reduction of quinones in the presence of the free fatty acids found in biodiesel on the glassy carbon electrode surface in the range of 0.4 V to 0.65 V versus Ag/AgCl/Cl- (3 molL-1). The proposed method was validated.

Association of free fatty acids with the insulin-resistant state but not with central obesity in individuals from Venezuela

Campos,Gilberto; Fernández,Virginia; Fernández,Erika; Molero,Emperatriz; Morales,Luz Marina; Raleigh,Xiomara; Connell,Lissette; Ryder,Elena
Fonte: Universidad del Zulia Publicador: Universidad del Zulia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2010 EN
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Individuals with insulin resistance (IR) usually have upper body obesity phenotype, often accompanied by an increase in plasma free fatty acids (FFA). Since the Venezuelan population has a high frequency of IR and central obesity, the purpose of this work was to determine FFA levels in 47 Venezuelan individuals, men and women, 24-58 years old, and analyze their relationship with central obesity and parameters of carbohydrate and lipid metabolism. Basal concentrations of TG, total cholesterol, LDL-C, and HDL-C were measured, and FFA, glucose and insulin, at basal state and at different times after a glucose load. Eighteen individuals presented insulin resistance (HOMA-IR >2.7) and 29 were non-insulin resistant (non-IR). Insulin resistant individuals (IR) had higher waist circumference, BMI and basal concentrations of FFA than the non-IR. No differences were observed in skin folds and other basal lipids studied. The increased FFA seemed to be related to the IR associated to BMI and not to central obesity, since the difference between IR and non-IR disappeared when they were matched for waist circumference. After a glucose load, FFA decreased in both groups, but remained significantly elevated in IR subjects. This effect disappeared after matching for BMI or waist circumference...