Search results for "acides gras"

Effect of acyl-CoA oxidase activity on the accumulation of gamma-decalactone by the yeast Yarrowia lipolytica: a factorial approach.

2007

International audience; beta-Oxidation is a cyclic pathway involved in the degradation of lipids. In yeast, it occurs in peroxisomes and the first step is catalyzed by an acyl-CoA oxidase (Aoxp). The yeast Yarrowia lipolytica possesses several genes (POX) coding for Aoxps. This study is based on the factorial analysis of results obtained with the many POX derivative strains that have been constructed previously. The effect of interactions between Aoxps on the acyl-CoA oxidase (Aox) activity was important even at the second order. We then investigated the effect of Aox activity on growth and lactone production. Aox activity was correlated with acidification of the medium by cells and with ce…

Approche nutritionnelle de la thérapie du syndrome de l'œil sec : prévention par les acides gras polyinsaturés

2008

Dry eye disease affects 15% of the population over the age of 65. It is characterized mainly by inflammation of the ocular surface (tear film, conjunctiva and cornea) which represents a relevant target for therapeutic strategies. The side effects and long-term intolerance of anti-inflammatory drugs give rise to an increasing interest for dietary components exhibiting anti-inflammatory properties, such as polyunsaturated fatty acids (PUFAs). In these studies, we developed a scopolamine-induced dry eye model in the rat that mimics changes occurring in Humans suffering from moderate dry eye. We described the time course of clinical signs, inflammation and mucin production loss. We investigated…

Involvment of docosanoïc acid (C22=0), and of very long chain fatty acids (tetracosanoïc acid (C24=0), hexacosanoïc acid (C26=0) in Alzheimer's disea…

2013

In the brain and in the plasma of patients with Alzheimer’s disease (AD), marked accumulation of C22:0 and of very long chain fatty acids (C24:0 ; C26:0) have been reported. Important decreases of docosahexaenoic acid (DHA; C22:6 n-3) have also been described as well as quantitative and qualitative modifications of plasmalogens. Altogether, these lipid modifications suggest an implication of peroxisomal metabolism disorders in the physiopathology of AD. Therefore, the biological activities of C22:0, C24:0 and C26:0 have been studied on human neuronal cells SK-N-BE. On these cells, the lipotoxicity of fatty acids (C22:0, C24:0 and C26:0) leads to various cellular modifications: topographical…

Acides gras polyinsaturés de la rétine : ont-ils une origine alimentaire ? Lipid Nutri+

2010

National audience; L’objectif du présent article est de faire le point sur l’origine des acides gras polyinsaturés dans la rétine neurale, en se focalisant en particulier sur le DHA. Nous appuierons notre propos en particulier sur nos données récentes obtenues sur des sujets décédés chez qui la rétine neurale et le couple EPR/choriocapillaire ont été prélevés et analysés pour leur contenu en lipides. Le profil en acides gras du tissu adipeux nous a servi de marqueur de consommation. Nous avons ainsi pu rechercher si les teneurs en AGPI de la rétine neurale sont le reflet des habitudes alimentaires des sujets.

Synthèse et formulation de résines photopolymérisables issues de la biomasse : application pour l'impression Braille

2014

The work of the PhD deals with the synthesis of polymerizable monomers derived from biomass, the study of their photopolymerization and the characterization of the resulting materials. The formulated monomers were tested in a printing method of Braille characters.The monomers were prepared in a two-steps reaction that is simple, economic and environmentally friendly. The first step comprised a reaction between glycerol derivatives (glycerol carbonate or glycidol) and fatty acids. In the second step, the obtained [alpha]-monoglycerides were functionalized to obtain photopolymerizable monomers. The different obtained monomers that bear (meth)acrylate and/or epoxy groups were photopolymerized …

Evaluation of the toxicity of mussels from 2 sites of the Moroccan Atlantic Coast (Jorf Lasfar and Oualidia) used as bioindicators of contamination :…

2012

Toxic substances generated by various human activities are spilled on different area of the Moroccan coast. Shellfishes can concentrate pollutants and have some adverse effects on human health through the food chain. Despite the strengthening of food safety rules, the involvement of chemical pollution of food on metabolic disorders is not known. To predict the impact of pollutants on the aquatic ecosystem and human health, the development of appropriate biomonitoring tools is required.We quantified heavy metals (Cd, Cr and Pb) in mussels (Mytilus galloprovincialis) from two sites of Moroccan Atlantic coast (industrial site Jorf Lasfar (JL) and touristic site Oualidia (OL)) due to the proxim…

impact of dietary intake of n-3 polyunsaturated fatty acids on the physiology of the peripheral olfactory system in young mice

2021

Abstract : Olfaction plays a major role in the detection of volatile chemical signals present in the environment and triggers behaviors such as food intake, social interactions or danger avoidance. Recent studies suggested that nutritional and metabolic status of individuals may influence their olfactory capacities. Olfactory disorders have been observed in people with pathologies such as obesity and diabetes as well as in rodents exposed to obesogenic or diabetogenic diets. The physiological mechanisms underlying these dysfunctions are not known. One hypothesis is that a nutritional imbalance in lipids might alter the functioning of the peripheral olfactory system. In this context, the obj…

Effet de la diversité botanique des pâturages de montagne sur le profil en acides gras et les caractéristiques sensorielles des laits.

2007

The Elovl5 enzyme in breast cancer : regulation of cancer cell proliferation and metastasis

2021

Breast cancer is the most diagnosed cancer and the leading cause of cancer death in women. The 5-year relative survival rate is less than 30% for metastatic breast cancer and metastases account for more than 75% of breast cancer deaths. Fatty acid metabolism is altered in cancer and contributes to tumor progression and metastasis. Here, we were interested in Elongation of very long chain fatty acids protein 5 (Elovl5) which catalyzes the elongation of long-chain fatty acids. We observed that the tumors from patients with a breast cancer had a lower expression of Elovl5 than paired normal breast tissue. However, low expression of Elovl5 is associated with a worse prognosis in breast cancer p…

Etude du contrôle hédonique de la prise alimentaire par l'analyse des potentiels évoqués gustatifs

2016

Hedonic control of food intake has been studied using neurophysiological investigations in animals and functional imaging in humans. Gustatory evoked potentials (GEPs), a higher time resolution technique than functional imaging, have never been used for this purpose. The first aim of this thesis was to establish a reliable recording of GEPs in humans, in response to a sapid stimulus. The second aim was to determine the GEPs modifications according to the hedonic value of food intake. GEPs recording was performed in response to an intermittent stimulation of a sapid solution in more than 100 young healthy subjects. The comparisons between cerebral recordings in response to water or paraffin …