Search results for "Lipids"
showing 10 items of 2228 documents
The Influence of Acetylcholine and Choline on the Incorporation of Phosphate into Phospholipids of Etiolated Bean Hypocotyl Hooks
1980
Summary Acetylcholine influenced the radiolabelling of phospholipids in vivo in etiolated hypocotyl tissue of dwarf beans in darkness. Under aerobic conditions the specific activity of the phospholipids was decreased and under anaerobic conditions increased. The biosynthesis of phospholipids was strongly increased by the bivalent cations calcium and manganese and decreased by 2,4-dinitrophenol, anaerobiosis, atropine and ascorbic acid. Magnesium stimulated the uptake of the radioactive phosphate but not the specific activity of the phospholipids. The results are discussed in comparison with the «phospholipid-effect» of acetylcholine in animal tissues.
Mixtures of lecithin with polymerizable derivatives of cholesterol. A monolayer film balance study.
1986
One of the best investigated binary lipid mixtures is the lecithin-cholesterol system. We show here that it is possible to modify the cholesterol in such a way that it can be polymerized without changing its behaviour in mixtures with lecithin. The polymerizable derivatives exhibit a very similar phase diagram in the mixture with dipalmitoyl-phosphatidylcholine as the cholesterol itself. This is demonstrated by filmbalance measurements.
Biocatalyzed acidolysis of soybean oil triacylglycerols to increase oleic acid content
2004
Lipase catalyzed acidolysis of triacylglycerols (TAG) of soybean oil with oleic acid in organic solvent was studied; immobilized lipase from Rhizomucor miehei was used and the effects of reaction time, incubation temperature and enzyme load on TAG total and positional fatty acid (FA) percentage compositions were investigated. The results show that oleic acid incorporation was high after 24 and 48 h, while after 72 h a lower level of oleic acid in TAG was observed. Moreover, for the reactions carried out at 30 and 40 degrees C, it was observed that the oleic acid level was about 46.5% while ligtly higher values (about 49%) were observed at 50 degrees C; however, under this last condition, th…
Development of antibiotic loaded biodegradable matrices to prevent superficial infections associated to total knee arthroplasty.
2019
Abstract Development of a pharmaceutical form for the superficial infections related with arthroplasties would be helpful for clinical practice. In this context, we set out to evaluate ciprofloxacin and gentamicin elution from systems based on chitosan. Films and semisolid hydrogels containing chitosan alone (2%) or in combination with gelatin (6%) or different proportions (from 12% to 36%) of tetrakis-(hydroxymethyl)-phosphonium-chloride (THPC) were tested as delivery systems. Different antibiotic doses were assayed (0.5 mg/cm2,1 mg/cm2 and 2 mg/cm2). Antibiotic release was studied for each formulation. In vitro cytocompatibility studies and a simulation exercise for bioactivity evaluation…
Eutrophication reduces the nutritional value of phytoplankton in boreal lakes
2019
Eutrophication (as an increase in total phosphorus [TP]) increases harmful algal blooms and reduces the proportion of high-quality phytoplankton in seston and the content of ω-3 long-chain polyunsaturated fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) in fish. However, it is not well-known how eutrophication affects the overall nutritional value of phytoplankton. Therefore, we studied the impact of eutrophication on the production (as concentration; μg L−1) and content (μg mg C−1) of amino acids, EPA, DHA, and sterols, i.e., the nutritional value of phytoplankton in 107 boreal lakes. The lakes were categorized in seven TP concentration categories ranging from ultra…
Appendix B. Fatty acid and sterol profiles of terrestrial particulate organic carbon (t-POC), bacteria, and phytoplankton diets.
2016
Fatty acid and sterol profiles of terrestrial particulate organic carbon (t-POC), bacteria, and phytoplankton diets.
Multisensory perception of dietary faty-acids in Drosophila.
2012
International audience; Fatty-acids (FAs) are crucial for animal survival and reproduction. However, our knowledge of the mechanisms underlying the perception and preference of dietary FA is limited, particularly in invertebrates. We obtained behavioral data with wild-type Drosophila melanogaster larvae and adults showing a clear preference to some of the FAs tested (C14:0, C16:0, C18:0, C18:1, C18:2, C18:3). These data, based on tests involving both individuals and groups, showed that larvae prefer desaturated FAs whereas adults prefer saturated FAs. Moreover, we found that larval and adult responses relied on olfaction and taste modalities, and maybe also on mechanoperception [1]. We will…
24S-hydroxycholesterol and cholesterol-24S-hydroxylase (CYP46A1) in the retina: from cholesterol homeostasis to pathophysiology of glaucoma.
2011
http://www.sciencedirect.com/; International audience; Free cholesterol is the predominant form of cholesterol in the neural retina. The vertebrate neural retina exhibits its own capacity to synthesize cholesterol and meets its demand also by taking it from the circulation. Defects in cholesterol synthesis and trafficking in the neural retina has detrimental consequences on its structure and function, highlighting the crucial importance of maintaining cholesterol homeostasis in the retina. Our purpose was to give a review on the functioning of the retina, the role of cholesterol and cholesterol metabolism therein, with special emphasis on cholesterol-24S-hydroxylase (CYP46A1). Similar to th…
In vivo consequences of cholesterol-24s-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina
2011
Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol in neurons and participates in cholesterol homeostasis in the central nervous system, including the retina. We aimed to evaluate the consequences of CYP46A1 inhibition by voriconazole on cholesterol homeostasis and function in the retina. Rats received daily intraperitoneal injections of voriconazole (60mg/kg), minocycline (22mg/kg), voriconazole plus minocycline, or vehicle during five consecutive days. The rats were submitted to electroretinography to monitor retinal functionality. Cholesterol and 24S-hydroxycholesterol were measured in plasma, brain and retina by gas chromatography-mass spectrometry. T…
The mechanisms of the action of omega-3s in the retina
2013
Age-related Macular Degeneration (AMD) is the leading cause of visual loss in Western countries after the age of 50y. Based on large-scale epidemiologic studies, it appears now as evident that omega-3 polyunsaturated fatty acids (PUFAs) provide benefits in preventing both, early and late stages of AMD. The aim of this paper is to summarize the knowledge about the biological mechanisms by which omega-3 PUFAs may be protective for the retina. The content of this presentation will range from biochemical data about the occurrence of omega-3 PUFAs in retinal cell membranes to results from cellular and animal studies showing that omega-3 PUFAs can influence processes involved in signal transducti…