• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 4
  • 4
  • 2
  • 1
  • Tagged with
  • 19
  • 19
  • 19
  • 19
  • 18
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 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

Fluktuace hladin mastných kyselin v tkáních náhle zemřelých osob a srovnání s hodnotami u patologických stavů / The fluctuation of fatty acids levels in the tissues of suddenly deceased persons and comparison with values in pathological states

Čunátová, Alena January 2020 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Alena Čunátová Supervisor of Diploma Thesis: Mgr. Monika Kuchařová, Ph.D. Title of Diploma Thesis: The fluctuation of fatty acids levels in the tissues of suddenly deceased persons and comparison with values in pathological states Fatty acids and their metabolites are significantly involved in many physiological and pathological processes. This thesis monitors the levels of selected fatty acids in human tissues and the effect of long-term disease on their stores. In addition to the general characteristics, the theoretical part focuses on the intake of polyunsaturated fatty acids and their importance in the human body. It also deals with the effects of eicosanoids and other fatty acid metabolites. Methods used in fatty acid bioanalysis are also described. In the experimental part, the proportion of fatty acids in seven tissue types was compared between two groups of donors. One of them included 8 relatively young, healthy, suddenly deceased individuals. The second group included 12 elderly polymorbid patients. The obtained tissue samples were adjusted using extraction and derivatization techniques. Gas chromatography with flame ionization detection was used for analysis. The measured...
12

Stanovení hladin mastných kyselin ve vybraných tkáních / The determination of fatty acids level in chosen tissues

Kynclová, Kamila January 2021 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Kamila Kynclová Supervisor of Diploma Thesis: Mgr. Monika Kuchařová, Ph.D. Title of Diploma Thesis: Determination of fatty acids levels in selected human tissues Fatty acid are an essential part of many metabolic processes in the body. The theoretical part of the the thesis presents primarily omega-3 and omega-6 fatty acids, their general characteristics, metabolism and their effect on various disease. The roles of fatty acid in cancer, neuropsychiatric and inflammatory diseases are described here. The thesis also mentions the method of gas chromatography, which was used to determine the levels of fatty acids. The experimental part of the thesis includes method, chromatographic analysis and results. 13 fatty acids in 7 different tissues were analyzed: subendocardial tissue, liver parenchymal tissue, kidney and adrenal tissue, skeletal muscle tissue, adipose and brain tissue. Tissues were collected from 20 healthy, suddenly deceased, cadavers. Donors were divided into two groups according to age. The obtained data were statistically processed and divided according to individual fatty acids. In the end the results between the two groups were evaluated with a possible explanation of the...
13

Treatment of Hypertriglyceridemia with Omega-3 Fatty Acids: A Systematic Review

Lewis, Amanda Gloria 29 June 2004 (has links) (PDF)
Purpose: To 1) critically appraise available randomized controlled trials (RTCs) addressing the efficacy of long-chain ω-3 fatty acids as a secondary prevention agent of hypertriglyceridemia, and 2) make recommendations for clinical practice. Data Sources: All RCTs identified from several databases from 1993-2003 were reviewed by two independent reviewers who extracted data from each study and used the previously tested Boyack and Lookinland Methodological Quality Index (MQI) to determine study quality. Results: Ten studies reported long-chain ω-3 fatty acids to be effective in the treatment of hypertriglyceridemia. The average decrease in triglycerides (TG) was 29%, total cholesterol (TC) 11.6%, very low density lipoprotein (VLDL) 30.2%, and low-density lipoprotein (LDL) 32.5%. One study found LDLs to increase by 25%. The average increase in high-density lipoprotein (HDL) was 10%. The overall average MQI score was 36% (26%-54%). Many of the RCTs had serious shortcomings including short duration, lack of a power analysis, no intention to treat analysis, no report of blind assessment of outcome, and lack of dietary control as a confounding variable. Conclusions/Implications: Overall study methodology was weak. Although the evidence supporting the use of long-chain ω-3 fatty acids in the secondary prevention of hypertriglyceridemia is reasonably strong, until there are larger RCTs of stronger methodological quality, it is not recommended to treat hypertriglyceridemia with ω-3 fatty acid supplementation in lieu of lipid lowering medications.
14

Fatty Acids and Risk of Fracture in Postmenopausal Women

Orchard, Tonya Sue 25 July 2011 (has links)
No description available.
15

Efeito antioxidante dos compostos fenólicos de especiarias sobre os ácidos graxos das séries ω 3 e ω 6 / Influence of spices phenolic compounds on lipoperoxidation and lipid profile of rats tissues

Moreira, Ana Vládia Bandeira 19 February 2003 (has links)
Dentro da perspectiva da utilização de compostos fenólicos como antioxidantes naturais para minimizar os efeitos in vitro e in vivo do processo oxidativo dos lípides insaturados, foi realizada a monitoração dietética de duas dietas ricas em lípides das séries ω3 e ω6 e a suplementação de um chá de uma mistura de especiarias, em ratos Wistar, com o objetivo de verificar a influência dos compostos fenólicos, presentes nas especiarias, sobre o metabolismo de ácidos graxos das séries ω3 e ω6. Extratos e frações das especiarias mostarda, canela e erva doce foram obtidos e tiveram suas atividades antioxidantes testadas em sistemas aquoso (cooxidação de substratos com o uso de ácido linoléico/β-caroteno) e lipídico (RANCIMAT) e o perfil de compostos fenólicos identificados e quantificados por CGMS. A partir de uma mistura de especiarias, foi elaborado um chá que foi fornecido aos animais de cada grupo dietético (ω3 e ω6). Após 45 dias de tratamento, os animais foram sacrificados e tiveram seus tecidos coletados para análise de TBARs e do perfil lipídico por CGMS. Todos os extratos das especiarias apresentaram atividade antioxidante equivalente ou superior ao BHT. Foram identificados por CGMS os ácidos fenólicos: catecol, salicílico e caféico. Foi obtido nos tecidos dos animais que o somatório do perfil de ácidos graxos saturados e dos insaturados apresentaram diferença entre os grupos testes e controles. Logo, no tecido cerebral, o EPA foi incorporado apenas no grupo ω3 que recebeu o extrato das especiarias. Já para o DHA, do mesmo grupo dietético, os tecidos hepático e renal também apresentaram incorporação aumentada em relação ao controle. No grupo dietético ω6, destaca-se um aumento no percentual de incorporação do ácido linoléico nos tecidos cardíaco e renal no grupo experimental. Enquanto, para o ácido araquidônico, houve diferença em todos os tecidos. Já, para os resultados da lipoperoxidação, observou-se que todos os tecidos dos animais que receberam o extrato das especiarias apresentaram baixos valores em comparação aos seus respectivos controles. Este estudo também avaliou a ação de compostos fenólicos do chá da mistura das especiarias mostarda, canela e erva doce sobre as enzimas lipoxigenase e cicloxigenase. O extrato da mistura das especiarias a 100 e 200 ppm foi adicionado no meio de reação contendo o substrato e a enzima lipoxigenase 1B da Sigma com 112.000 und/mg. A cicloxigenase foi obtida de vesículas seminais de carneiro e seguiu-se o mesmo protocolo de atividade para a lipoxigenase. Indometacina foi o inibidor utilizado como controle positivo da reação. Observou-se que a 200 ppm, como na concentração do chá (0,02%), a lipoxigenase foi inibida em aproximadamente em 90%. Já para a cicloxigenase, o extrato a 200 ppm resultou numa média de 75% de inibição da atividade da enzima, enquanto que a indomentacina apresentou uma média de 77% de inibição. A absorção aparente do chá das especiarias indicou que os fenólicos presentes na mistura foram absorvidos em média de 75%. O estudo histopatológico dos intestinos delgados dos animais não apresentou nenhuma diferença na área de absorção entre o grupo experimental e o controle. Estes dados sugerem, portanto, um efeito antioxidante das substâncias fenólicas identificadas nas especiarias sobre os ácidos graxos das séries ω3 e ω6, podendo agir diretamente: (1) no alimento (óleo), (2) com modificação do perfil lipídico, (3) proteção quanto à oxidação de tecidos e (4) inibição das enzimas da biossíntese dos eicosanóides. / Considering the perspective for the use of phenolic compounds as natural antioxidants to minimize in vitro and in vivo effects of oxidative processes on unsaturated lipids, this work monitored Wistar rats fed with two diets rich in ω3 and ω6 polyunsaturated lipids, supplemented with tea made from a blend of spices. The objective of the work was to study the influence of phenolic compounds present in spices on the metabolism of ω3 and ω6 fatty acids. Extracts and fractions of mustard, cinnamon and anise were obtained and had their antioxidant activity tested in aqueous (co-oxidation of substrates using linoleic acid/β-carotene) and lipidic systems (RANCIMAT). Their phenolic compounds profile was determined and quantified using CGMS. The rats of each diet group (ω3 and ω6) were given tea made from a blend of spices and sacrificed after 45 days. Their tissues were then collected and analyses of TBARS and lipid profile were performed using CGMS. Ali the extracts of spices showed equal or higher antioxidant activity than BHT. The following phenolic acids were identified using CGMS: cathecol, salicilic and cafeic. It was observed that the total amount of the profile of saturated and unsaturated fatty acids in the rat tissues were different in the test group and the control group. In brain tissue, EPA was found only in the ω3 diet group which was given the tea. Concerning DHA, liver and kidney tissues of the same diet group showed higher concentrations than the control group. In the ω6 diet group, an outstanding increase of linoleic acid in cardiac and kidney tissues was found. Concerning the arachidonic acid, a difference in concentration was observed in ali tissues. Ali the tissues from rats given the tea presented a lower level of lipid peroxidation than their respective control groups. The present research also evaluated the action of phenolic compounds found in the tea made from the blend of mustard, cinnamon and anise on the enzymes lipoxygenase and cycloxygenase. The extract of the blend of spices, in the concentrations of 100 and 200 ppm, was added to the substrate and Sigma lipoxygenase 112.000 units/mg. Cycloxygenase was obtained from sheep seminal bladders and underwent the same protocol as lipoxygenase. Indomethacin was the inhibitor used as the positive control of the reaction. It was observed that in the concentration of 200 ppm (that is 0.02%, the same concentration as in the tea), lipoxygenase presented an average 90% inhibition. The extract of cycloxygenase 200 ppm presented 75% inhibition of the enzyme activity, while indomethacin presented an average 77% inhibition. It was found that around 75% of the phenolic compounds present in the tea made from the blend of spices were absorbed, thus leading to the conclusion that apparent absorption of the tea took place. Histopathologic examinations on the small intestines of the rats did not reveal any difference in the absorption area between the experimental and the control groups. Such results suggest therefore an antioxidant effect of the phenolic substances identified in the spices on the ω3 and ω6 fatty acids, this effect being possible directly (1) on the food (oil) , (2) modification of the profile fatty acids, (3) oxidation protection tissues and, (4) inhibition of enzymes of eicosanoids biosinthesys.
16

Effect of n-3 vs n-6 fatty acids and methyl ethyl ketone peroxide on adipose tissue cellularity, muscle weight, and lipoprotein lipase activity in rats

Venkateswaran, Lakshmi, 1965- 22 March 1993 (has links)
Graduation date: 1993
17

Avaliação da estabilidade oxidativa do óleo de chia microencapsulado

Inácio, Alexandre Guimarães 22 February 2017 (has links)
CAPES / O óleo de chia vem sendo amplamente estudado devido aos seus benefícios para a saúde humana, sendo fonte de ácidos graxos essenciais como o ômega-3 e ômega-6, além de diversos compostos antioxidantes. Contudo, assim como outros óleos ricos em ácidos graxos insaturados, ele possui baixa estabilidade oxidativa. A encapsulação do óleo de chia é uma alternativa para protegê-lo da luz e do oxigênio, fatores determinantes para o início das reações de degradação. O impacto da encapsulação sobre a proteção do óleo deve ser mensurado e no estudo de óleos e gorduras as técnicas de análise térmica vem ganhando destaque nos últimos anos devido a rapidez, precisão e facilidade de operação. Neste trabalho, o óleo de sementes de chia foi microencapsulado em cera de carnaúba e sua estabilidade térmica foi avaliada. Primeiramente, as micropartículas foram caracterizadas por Espectroscopia no Infravermelho Médio, Difração de Raios-X, Cromatografia Gasosa e Microscopia Eletrônica de Varredura, sendo verificado um alto índice de eficiência de encapsulação (97%), apresentando tamanhos micrométricos, formato esférico e sem fissuras. Calorimetria Diferencial de Varredura (DSC) foi utilizada nos modos isotérmico e não isotérmico a fim de determinar os parâmetros de Arrhenius do óleo in natura e microencapsulado. Foi possível verificar a efetiva proteção do óleo de chia conferida pelas micropartículas de cera de carnaúba, sendo detectado um aumento na temperatura de indução oxidativa de até 26º C nos ensaios não isotérmicos. As micropartículas contendo o óleo também foram submetidas ao ensaio de estabilidade acelerada em estufa. Os espectros obtidos através do Uv-Vis foram utilizados para análise quimiométrica e na determinação dos coeficientes de extinção a 232 e 270 nm, corroborando o aumento da estabilidade oxidativa observado nos ensaios calorimétricos. / Chia oil has been widely studied because of its benefits to human health, being source of important fatty acids like omega-3 and omega-6, in addition to several antioxidant compounds. However, like other oils rich in unsaturated fatty acids, it has low oxidative stability. The encapsulation of chia oil is an alternative to protect it from light and oxygen, factors that determine the beginning of degradation reactions. The impact of encapsulation on oil protection should be measured and in the study of oils and fats the techniques of thermal analysis have been gaining prominence in recent years due to the speed, precision and ease of operation. In this work, the oil of chia seeds was microencapsulated in carnauba wax and its thermal stability was evaluated. Firstly, the microparticles were characterized by Medium Infrared Spectroscopy, X-Ray Diffraction, Gas Chromatography and Scanning Electron Microscopy. A high encapsulation efficiency index (97%) was verified, presenting micrometric sizes, spherical shape without cracks. Differential Scanning Calorimetry (DSC) was used in isothermal and non-isothermal modes in order to determine the Arrhenius parameters of the natural and microencapsulated oil. It was possible to verify the effective protection of the chia oil conferred by the microparticles of carnauba wax, and an increase in the oxidative induction temperature of up to 26º C was detected in non-isothermal tests. The microparticles containing the oil were also subjected to the schaal oven test and the spectra obtained through Uv-vis were evaluated by chemometrics and determination of the extinction coefficients at 232 and 270 nm, corroborating the increase in the oxidative stability observed in the calorimetric assays.
18

Efeito antioxidante dos compostos fenólicos de especiarias sobre os ácidos graxos das séries ω 3 e ω 6 / Influence of spices phenolic compounds on lipoperoxidation and lipid profile of rats tissues

Ana Vládia Bandeira Moreira 19 February 2003 (has links)
Dentro da perspectiva da utilização de compostos fenólicos como antioxidantes naturais para minimizar os efeitos in vitro e in vivo do processo oxidativo dos lípides insaturados, foi realizada a monitoração dietética de duas dietas ricas em lípides das séries ω3 e ω6 e a suplementação de um chá de uma mistura de especiarias, em ratos Wistar, com o objetivo de verificar a influência dos compostos fenólicos, presentes nas especiarias, sobre o metabolismo de ácidos graxos das séries ω3 e ω6. Extratos e frações das especiarias mostarda, canela e erva doce foram obtidos e tiveram suas atividades antioxidantes testadas em sistemas aquoso (cooxidação de substratos com o uso de ácido linoléico/β-caroteno) e lipídico (RANCIMAT) e o perfil de compostos fenólicos identificados e quantificados por CGMS. A partir de uma mistura de especiarias, foi elaborado um chá que foi fornecido aos animais de cada grupo dietético (ω3 e ω6). Após 45 dias de tratamento, os animais foram sacrificados e tiveram seus tecidos coletados para análise de TBARs e do perfil lipídico por CGMS. Todos os extratos das especiarias apresentaram atividade antioxidante equivalente ou superior ao BHT. Foram identificados por CGMS os ácidos fenólicos: catecol, salicílico e caféico. Foi obtido nos tecidos dos animais que o somatório do perfil de ácidos graxos saturados e dos insaturados apresentaram diferença entre os grupos testes e controles. Logo, no tecido cerebral, o EPA foi incorporado apenas no grupo ω3 que recebeu o extrato das especiarias. Já para o DHA, do mesmo grupo dietético, os tecidos hepático e renal também apresentaram incorporação aumentada em relação ao controle. No grupo dietético ω6, destaca-se um aumento no percentual de incorporação do ácido linoléico nos tecidos cardíaco e renal no grupo experimental. Enquanto, para o ácido araquidônico, houve diferença em todos os tecidos. Já, para os resultados da lipoperoxidação, observou-se que todos os tecidos dos animais que receberam o extrato das especiarias apresentaram baixos valores em comparação aos seus respectivos controles. Este estudo também avaliou a ação de compostos fenólicos do chá da mistura das especiarias mostarda, canela e erva doce sobre as enzimas lipoxigenase e cicloxigenase. O extrato da mistura das especiarias a 100 e 200 ppm foi adicionado no meio de reação contendo o substrato e a enzima lipoxigenase 1B da Sigma com 112.000 und/mg. A cicloxigenase foi obtida de vesículas seminais de carneiro e seguiu-se o mesmo protocolo de atividade para a lipoxigenase. Indometacina foi o inibidor utilizado como controle positivo da reação. Observou-se que a 200 ppm, como na concentração do chá (0,02%), a lipoxigenase foi inibida em aproximadamente em 90%. Já para a cicloxigenase, o extrato a 200 ppm resultou numa média de 75% de inibição da atividade da enzima, enquanto que a indomentacina apresentou uma média de 77% de inibição. A absorção aparente do chá das especiarias indicou que os fenólicos presentes na mistura foram absorvidos em média de 75%. O estudo histopatológico dos intestinos delgados dos animais não apresentou nenhuma diferença na área de absorção entre o grupo experimental e o controle. Estes dados sugerem, portanto, um efeito antioxidante das substâncias fenólicas identificadas nas especiarias sobre os ácidos graxos das séries ω3 e ω6, podendo agir diretamente: (1) no alimento (óleo), (2) com modificação do perfil lipídico, (3) proteção quanto à oxidação de tecidos e (4) inibição das enzimas da biossíntese dos eicosanóides. / Considering the perspective for the use of phenolic compounds as natural antioxidants to minimize in vitro and in vivo effects of oxidative processes on unsaturated lipids, this work monitored Wistar rats fed with two diets rich in ω3 and ω6 polyunsaturated lipids, supplemented with tea made from a blend of spices. The objective of the work was to study the influence of phenolic compounds present in spices on the metabolism of ω3 and ω6 fatty acids. Extracts and fractions of mustard, cinnamon and anise were obtained and had their antioxidant activity tested in aqueous (co-oxidation of substrates using linoleic acid/β-carotene) and lipidic systems (RANCIMAT). Their phenolic compounds profile was determined and quantified using CGMS. The rats of each diet group (ω3 and ω6) were given tea made from a blend of spices and sacrificed after 45 days. Their tissues were then collected and analyses of TBARS and lipid profile were performed using CGMS. Ali the extracts of spices showed equal or higher antioxidant activity than BHT. The following phenolic acids were identified using CGMS: cathecol, salicilic and cafeic. It was observed that the total amount of the profile of saturated and unsaturated fatty acids in the rat tissues were different in the test group and the control group. In brain tissue, EPA was found only in the ω3 diet group which was given the tea. Concerning DHA, liver and kidney tissues of the same diet group showed higher concentrations than the control group. In the ω6 diet group, an outstanding increase of linoleic acid in cardiac and kidney tissues was found. Concerning the arachidonic acid, a difference in concentration was observed in ali tissues. Ali the tissues from rats given the tea presented a lower level of lipid peroxidation than their respective control groups. The present research also evaluated the action of phenolic compounds found in the tea made from the blend of mustard, cinnamon and anise on the enzymes lipoxygenase and cycloxygenase. The extract of the blend of spices, in the concentrations of 100 and 200 ppm, was added to the substrate and Sigma lipoxygenase 112.000 units/mg. Cycloxygenase was obtained from sheep seminal bladders and underwent the same protocol as lipoxygenase. Indomethacin was the inhibitor used as the positive control of the reaction. It was observed that in the concentration of 200 ppm (that is 0.02%, the same concentration as in the tea), lipoxygenase presented an average 90% inhibition. The extract of cycloxygenase 200 ppm presented 75% inhibition of the enzyme activity, while indomethacin presented an average 77% inhibition. It was found that around 75% of the phenolic compounds present in the tea made from the blend of spices were absorbed, thus leading to the conclusion that apparent absorption of the tea took place. Histopathologic examinations on the small intestines of the rats did not reveal any difference in the absorption area between the experimental and the control groups. Such results suggest therefore an antioxidant effect of the phenolic substances identified in the spices on the ω3 and ω6 fatty acids, this effect being possible directly (1) on the food (oil) , (2) modification of the profile fatty acids, (3) oxidation protection tissues and, (4) inhibition of enzymes of eicosanoids biosinthesys.
19

Bioprocessing of soybean seed-coats for production of proteins & omega-3 fatty acids using Pythium isolates

Burkey, Carren Nyambare 10 August 2020 (has links)
No description available.

Page generated in 0.0688 seconds