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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.
291

Evaluation of a functional oil composed of medium chain triacylglycerols, phytosterols and n-3 fatty acids on the cardiovascular risk profile of overweight women

Bourque, Christine. January 2002 (has links)
We examined the effect of a functional oil (FctO), with potential weight-controlling and blood lipid-lowering attributes, vs beef tallow as control (C), on the cardiovascular risk profile of overweight women. The FctO comprised energy expenditure-enhancing medium chain triacylglycerols, cholesterol-lowering phytosterols and triacylglycerol-suppressing n-3 fatty acids. In a randomized, single-blind, crossover design, inpatient trial, 17 women consumed each oil as part of a controlled, supervised, energy-adjusted diet for 27 days. Body weight decreased similarly during both dietary periods. Plasma total and LDL cholesterol levels decreased by 4.8% and 10.4% following FctO, and were lower by 9.0% and 16.4% respectively, after FctO vs C. HDL cholesterol and circulating triacylglycerol levels were unaffected by treatment, though HDL:LDL and HDL:total cholesterol ratios increased by 19.5% and 9.4% on FctO. Plasma total homocysteine levels were higher on FctO vs C. Plasma glutathione increased with FctO supplementation. / We conclude that consumption of FctO improves the overall cardiovascular risk profile of overweight women.
292

Facilitating Clinical Trials of Parenteral Lipid Strategies for the Prevention of Intestinal Failure Associated Liver Disease (IFALD) in Infants

Diamond, Ivan R. 15 November 2013 (has links)
Objective: The objective of this thesis was to facilitate clinical trials of the optimal lipid based approach (e.g.: omega-3 containing lipid emulsions or minimization of conventional lipid) for the prevention of Intestinal Failure Associated Liver Disease (IFALD). This was achieved through 3 related projects. Project 1: The first project examined the risk of advanced IFALD associated with exposure to conventional intravenous lipid in a logistic regression model. The study demonstrated that each day of conventional lipid (> 2.5 g/kg/day) was associated with a significant increase in the risk of advanced IFALD [Odds Ratio: 1.04 95% CI: 1.003 – 1.06]. Project 2: The second project surveyed experts in Intestinal Failure regarding their beliefs of the efficacy of lipid minimization and lipid emulsions containing omega-3 fatty acids relative to conventional emulsions. The goal of the project was to develop prior distributions of the treatment response for these therapies that can be used in Bayesian analyses of clinical trials. Our results demonstrated consistent expert opinion that the novel lipid based approaches are superior to conventional therapy. Estimates of the treatment effect were similar for the two approaches (median elicited treatment response, relative to conventional lipid, was a relative risk of 0.53 for omega-3 lipid and 0.45 for lipid minimization). Project 3: The final project was a pilot randomized controlled trial of an omega-3 emulsion. The study demonstrated that the randomized design is a feasible strategy for evaluating lipid based approaches for the prevention of IFALD. A Bayesian preliminary assessment of the results of the trial, suggests a high likelihood that the trial will demonstrate a difference between the conventional and omega-3 emulsion evaluated in the trial. However, since the analysis was blinded, the direction of the difference is not known. Conclusion: This thesis will contribute to the design and analysis of high quality and feasible randomized trials that will allow investigators to address the optimal lipid based approach to the management of IFALD.
293

Synthesis of novel triglycerides from mackerel by-products and vegetable oils

Zuta, Charles Prince January 2003 (has links)
The study was designed to develop a nutraceutical product from by-products of fish processing. Fish oil was extracted from mackerel tissues (skin, viscera and muscle) using hexane-isopropanol (3:2 v/v) and chloroform-methanol (2:1 v/v) solvent systems. An oxidative study was carried out to determine the best processing and storage conditions to minimize autooxidation of mackerel oil. Urea complexation was used to concentrate polyunsaturated fatty acids (PUFA) from the extracted fish oil. The urea complexation process was optimized to determine the best reaction conditions for high yield of the omega-3 fatty acids in particular, and total PUFA. / Conjugated linoleic acid (CLA) was synthesized from four vegetable oils (sunflower, canola, soybean and corn) by alkaline isomerization. The CLA isomers and PUFA concentrated from mackerel tissues were used to synthesize triglycerides by lipase-catalyzed esterification. The effect of temperature, reaction medium, enzyme, moisture removal system and glycerol to fatty acid ratio on extent of synthesis were investigated. The synthesis process was also optimized using central composite design to determine the best conditions for high synthesis yield. The fatty acid composition and positional analyses were determined by GC-FID and electrospray ionization mass spectrometry (EI-MS) / The results showed that mackerel skins were most suitable for concentrating PUFA. The eicosapentaenoic acid (EPA) and -docosahexaenoic acid (DHA) content of fish oil from the tissues examined ranged between 6.3--9.7 (wt%) with an iodine value of 134 +/- 5.0. The baseline total PUFA content was increased from ca 21.0 to ca 83.0 (wt%) with an associated iodine value of 296 +/- 7.0 using urea complexation. Low (50 ppm and 100 ppm) levels of alpha-tocopherol in combination with low storage temperature (-40°C) showed lowest oxidation after 66 days of storage. High levels (250 and 500 ppm) of alpha-tocopherol were observed to be prooxidant based on TBARS, peroxide and conjugated diene measurements. Urea to fatty acid ratio and temperature were predominant effectors influencing the amounts of individual omega-3 fatty acids and total PUFA concentrated by urea complexation. The model developed for the optimized urea complexation process were capable of predicting the yields of EPA, DHA, total PUFA and Iodine values to a high degree of accuracy at R2 = 0.87, 0.96, 0.95, and 0.92 respectively. / Sunflower oil was most suitable for synthesizing conjugated linoleic acid by alkaline isomerization, compared with soybean, canola and corn oil. Two CLA isomers, c9,t11 and t10, c12 were most abundant and occurred in approximately equal proportions irrespective of vegetable oil used. Total CLA synthesized from sunflower oil was 93.5 +/- 3.5 (wt%) with the two major isomers making up 89 +/- 3.5 (wt%). Candida antartica lipase showed more synthesis activity than Mucor meihie in both organic and solvent-free systems. Analysis of isolated synthesized triglycerides by GC-FID and mass spectrometry showed that DHA, EPA, CLA and linolenic acid were the main fatty acids incorporated into the triglycerides. DHA and EPA were mostly esterified at the sn-2 position.
294

Effets des acides gras Oméga-3 sur la Cardioprotection: Etude des acides gras oméga-3 chez le rat et chez des patients porteurs d'un défibrillateur automatique implantable

Zeghichi, Sabrina 26 March 2009 (has links) (PDF)
Bien que le régime méditerranéen (MED) soit considéré comme le meilleur régime alimentaire pour prévenir les maladies cardiaques, on ignore toujours si l'adoption de MED résulte en une amélioration de la résistance du myocarde à l'ischémie et la reperfusion et en une prévention des arythmies ventriculaires. En conséquence, nous avons mené deux études : (1) vérifier si un profile lipidique de type MED; faible en gras saturés et en acides gras oméga-6 (ω6) et riche en acides gras oméga-3 (ω3) d'origines végétale et marine; peut réduire la taille d'infarctus et une meilleure récupération de la fonction ventriculaire gauche (FVG) dans un modèle de rat. Les rats MED ont été comparés avec des rats recevant des régimes riches en acides gras saturés ou en acides gras ω6. Les résultats montrent une grande accumulation des ω3 et une diminution de l'acide arachidonique dans le plasma, les membranes des cellules cardiaques et dans les mitochondries. Pareillement, les rats MED avaient une taille infarctus plus réduite par rapport aux deux autres groupes, tandis que FVG récupération n'était pas différente dans les trois groupes. La deuxième étude épidémiologique a été menée au Centre Hospitalier Universitaire de Grenoble pour déterminer une éventuelle corrélation entre les oméga-3 et la survenue de complications rythmiques. Deux cent trente huit patients porteurs de défibrillateurs automatiques implantables (DEF) ont été inclus. La composition en acides gras des globules rouges a été analysé et l'index oméga-3 a été calculée à partir de l'acide eicosapentaénoïque et acide docosahexaénoïque. Aucune différence significative entre les acides gras oméga-3 (ALA, EPA et DHA) ou l'index oméga-3 et la survenue d'événements n'a été observée entre quartiles. Néanmoins, l'index oméga-3 chez ces patients était déjà à des niveaux qui ont été démontrés avoir un pouvoir cardioprotecteur (8.6±1.59 à 8,8±1.76).
295

Replenishing what is Lost: Using Supplementation to Enhance Hippocampal Function in Fetal Alcohol Spectrum Disorders

Patten, Anna Ruth 22 April 2013 (has links)
Fetal Alcohol Spectrum Disorders (FASD) are the most common cause of cognitive impairment in the United States (Sokol et al., 2003). In young school children in North America and some Western European countries, recent reports have estimated the prevalence of FASD to be as high as 2-5% (May et al., 2009). Currently there are no widely accepted treatment options for FASD, mainly due to the fact that the underlying neurological deficits that occur with prenatal ethanol exposure (PNEE) are still largely unknown. This thesis examines the long-lasting changes that occur in the hippocampus following PNEE using biochemical and electrophysiological techniques. We find that PNEE produces a reduction of the endogenous antioxidant glutathione (GSH), resulting in an increase in oxidative stress that is accompanied by long-lasting reductions in long-term potentiation (LTP) of synaptic efficacy. Interestingly, males exhibited greater deficits in synaptic plasticity than females, despite similar reductions in GSH in both sexes. By depleting GSH in control animals we determined that LTP in the DG of female animals is more resistant to changes in GSH, which may explain the sexual dichotomy observed in these studies of PNEE. Based on these findings, ethanol-exposed animals received postnatal dietary supplementation with either a precursor of GSH, N-Acetylcysteine (NAC) or Omega-3 fatty acids. These supplements helped to counteract the effects of PNEE and improved hippocampal function. The findings in this thesis support the hypothesis that increasing antioxidant capacity can enhance hippocampal function, which in turn may improve learning and memory in FASD, providing a therapeutic avenue for children suffering with these disorders. / Graduate / 0570 Nutrition / 0317 Neuroscience / anna.r.patten@gmail.com
296

Replenishing what is Lost: Using Supplementation to Enhance Hippocampal Function in Fetal Alcohol Spectrum Disorders

Patten, Anna Ruth 22 April 2013 (has links)
Fetal Alcohol Spectrum Disorders (FASD) are the most common cause of cognitive impairment in the United States (Sokol et al., 2003). In young school children in North America and some Western European countries, recent reports have estimated the prevalence of FASD to be as high as 2-5% (May et al., 2009). Currently there are no widely accepted treatment options for FASD, mainly due to the fact that the underlying neurological deficits that occur with prenatal ethanol exposure (PNEE) are still largely unknown. This thesis examines the long-lasting changes that occur in the hippocampus following PNEE using biochemical and electrophysiological techniques. We find that PNEE produces a reduction of the endogenous antioxidant glutathione (GSH), resulting in an increase in oxidative stress that is accompanied by long-lasting reductions in long-term potentiation (LTP) of synaptic efficacy. Interestingly, males exhibited greater deficits in synaptic plasticity than females, despite similar reductions in GSH in both sexes. By depleting GSH in control animals we determined that LTP in the DG of female animals is more resistant to changes in GSH, which may explain the sexual dichotomy observed in these studies of PNEE. Based on these findings, ethanol-exposed animals received postnatal dietary supplementation with either a precursor of GSH, N-Acetylcysteine (NAC) or Omega-3 fatty acids. These supplements helped to counteract the effects of PNEE and improved hippocampal function. The findings in this thesis support the hypothesis that increasing antioxidant capacity can enhance hippocampal function, which in turn may improve learning and memory in FASD, providing a therapeutic avenue for children suffering with these disorders. / Graduate / 0570 Nutrition / 0317 Neuroscience / anna.r.patten@gmail.com
297

Prostate Cancer and Alpha-linolenic Acid

Carleton, Amanda 15 December 2010 (has links)
The objectives were to 1) conduct a meta-analysis to assess the association between alpha-linolenic acid (ALA) and prostate cancer; 2) analyze a trial of ALA on coronary heart disease with PSA as a post hoc outcome; 3) assess the effect of trial serum and also ALA directly on LNCaP cell growth. 1) The ALA meta-analysis of prospective and case-control studies showed no overall effect on prostate cancer. However, removal of one study from the analysis of prospective studies changed the result to a significant protective effect (RR=0.91; 95%CI:0.83,0.99). 2) No significant treatment difference was seen in the change in PSA in the randomized controlled trial. 3) The ALA treatment serum from the clinical trial did not affect LNCaP cell growth. However, ALA decreased LNCaP cell growth in a dose dependent manner when added to cell culture. The results provide no positive evidence for an effect of ALA on prostate cancer.
298

Prostate Cancer and Alpha-linolenic Acid

Carleton, Amanda 15 December 2010 (has links)
The objectives were to 1) conduct a meta-analysis to assess the association between alpha-linolenic acid (ALA) and prostate cancer; 2) analyze a trial of ALA on coronary heart disease with PSA as a post hoc outcome; 3) assess the effect of trial serum and also ALA directly on LNCaP cell growth. 1) The ALA meta-analysis of prospective and case-control studies showed no overall effect on prostate cancer. However, removal of one study from the analysis of prospective studies changed the result to a significant protective effect (RR=0.91; 95%CI:0.83,0.99). 2) No significant treatment difference was seen in the change in PSA in the randomized controlled trial. 3) The ALA treatment serum from the clinical trial did not affect LNCaP cell growth. However, ALA decreased LNCaP cell growth in a dose dependent manner when added to cell culture. The results provide no positive evidence for an effect of ALA on prostate cancer.
299

Linker-based Lecithin Oral Drug Delivery Systems

Chu, Jacquelene 04 December 2012 (has links)
In this study, pharmaceutical-grade and food-grade linker-based lecithin self-emulsifying delivery systems (SEDS) were developed with a combination of lipophilic and hydrophilic linkers. These additives at suggested concentrations are safe for pharmaceutical and food applications. The ratio of surfactant lecithin and linkers in these systems was optimized to develop surfactant in oil preconcentrates. The preconcentrates containing different surfactant concentrations and oil were diluted with fed state simulated intestinal fluid to produce pseudo-ternary phase diagrams and to identify the formulations that produced self-emulsifying or self-microemulsifying delivery systems. Optimal SEDS preconcentrates were evaluated using a dialyzer model to simulate intestinal uptake. An uptake of 39.6 mg/cm2 for the pharmaceutical-grade SEDS was obtained within 72 minutes, which promises substantial improvement in the bioavailability of hydrophobic actives. The optimal uptake of 12.2 mg/cm2 for food-grade SEDS suggests enhancement in the bioavailability of omega-3 fatty acids.
300

In vivo detection of alterations in fatty acyl species unsaturation in a mouse hepatocarcinogenesis model

Griffitts, Jeffrey Daniel. January 2008 (has links) (PDF)
Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 155-161.

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