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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.
21

Goma de soja: uma alternativa de emulsificante para dietas de poedeiras comerciais / Soy gum: an emulsifying alternative for diets of laying hens

Souza, Rosemary Pereira de Pedro [UNESP] 03 March 2017 (has links)
Submitted by ROSEMARY PEREIRA DE PEDRO SOUZA null (rosemaryppsouza@gmail.com) on 2017-04-07T21:23:24Z No. of bitstreams: 1 Dissertação - Rosemary P. de P Souza 07-04.pdf: 1118611 bytes, checksum: 9417b9cfa0ee4b0a1002991a20e5a5f8 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-17T14:40:37Z (GMT) No. of bitstreams: 1 souza_rpp_me_ilha.pdf: 1118611 bytes, checksum: 9417b9cfa0ee4b0a1002991a20e5a5f8 (MD5) / Made available in DSpace on 2017-04-17T14:40:37Z (GMT). No. of bitstreams: 1 souza_rpp_me_ilha.pdf: 1118611 bytes, checksum: 9417b9cfa0ee4b0a1002991a20e5a5f8 (MD5) Previous issue date: 2017-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O experimento foi conduzido no Setor de Avicultura da Universidade Estadual Paulista – UNESP, Faculdade de Engenharia de Ilha Solteira, com a finalidade de avaliar o efeito da inclusão de níveis crescentes de goma de soja (0, 1, 2, 3, 4 e 5%) na alimentação de poedeiras comercias, e verificar a viabilidade econômica de sua utilização como mais um produto comercial derivado da soja. Foram utilizadas 180 poedeiras comerciais leves da linhagem Lohmann, com 40 semanas de idade, durante o período de 112 dias (quatro ciclos de 28 dias), distribuídas em um delineamento inteiramente casualizado, totalizando 6 tratamentos com 5 repetições (6 aves por parcela). No experimento foram avaliados dados de parâmetros zootécnicos: porcentagem de postura (ave/dia), consumo de ração (g/ave/dia), peso dos ovos (g), conversão alimentar (kg/kg), qualidade interna e externa dos ovos e estabilidade oxidativa dos ovos. No que se refere aos parâmetros de desempenho a inclusão de 5% de goma na dieta aumentou o consumo de ração e a maior produção de ovos foi observada nos tratamentos com a inclusão de 3 e 5% de goma. Quanto ao peso médio dos ovos e massa de ovos a inclusão de goma a partir de 3% favoreceu o aumento dos mesmos. Para os parâmetros de qualidade dos ovos os tratamentos com 4 e 5% de goma foram os que apresentaram os menores valores de unidade Haugh, o aumento da coloração da gema ocorreu a partir da inclusão de 3% de goma. A estabilidade oxidativa dos ovos apresentou diferença (P<0,05) apenas para os ovos provenientes do tratamento com 4% de goma armazenados sob refrigeração por 21 dias. A análise econômica mostrou maior retorno econômico com a inclusão de apenas 1% de goma de soja na dieta. / The experiment was carried in the Poultry Sector of the Universidade Estadual Paulista - UNESP, Ilha Solteira Campus, in order to evaluate the effect of inclusion of increasing levels of soy gum (0, 1, 2, 3, 4 and 5 %) In the feeding of commercial laying hens, and verify the economic viability of this use as another commercial product derived from soybean. The study used 180 Lohmann commercial laying hens with 40 week old Lohmann commercial laying hens during the period of 112 days (four cycles of 28 days), distributed in a completely randomized design, totaling 6 treatments with 5 replicates (6 birds per plot). The evaluated parameters were feed intake (g/bird/day), egg weight (g), feed conversion (kg/kg), internal and external egg quality and oxidative stability of eggs. Regarding the performance parameters, the inclusion of 5% gum in the diet increased the feed intake and, the higher egg production was observed in the treatments with the inclusion of 3 and 5% of soy gum. Regarding the average egg weight and egg mass, the inclusion of soy gum from 3% favored their increase. For egg quality parameters treatments with 4 and 5% of soy gum were the ones with the lowest values of Haugh unit, the increase of the color of the yolk occurred from the inclusion of 3% of gum. The oxidative stability of the eggs presented a difference (P<0.05) only for the eggs from the treatment with 4% of gum stored under refrigeration for 21 days. The economic analysis showed a higher economic return with the inclusion of 1% of soy gum in the diet.
22

Choline Transport Links Phospholipid Metabolism and Inflammation in Macrophages

Snider, Shayne January 2017 (has links)
Choline is necessary for the synthesis of phosphatidylcholine (PC), the predominant phospholipid species and an important lipid intermediate. Macrophages, critical mediators of innate immunity, have been implicated in lipid dysregulation associated with metabolic disease. Despite the importance of choline in lipid metabolism, few studies have investigated the relationship between choline metabolism and inflammation. My research revealed that macrophage polarization increased choline metabolism and the expression of the choline transporter CTL1. In addition, choline deficient macrophages showed altered cytokine secretion, suggesting choline metabolism may play an important role in regulating the immune response. This study also describes the generation of a novel CTL1-/- mouse, which showed decreased choline uptake and incorporation into lipids. As an in vivo model for choline deficiency, CTL1-/- mice represent an important model for the future study of choline metabolism. Altogether, these findings suggest an important relationship exists between choline metabolism and inflammation.
23

Synthesis of Phosphatidylethanolamine Lipids for Model Studies of the Cell Membrane

Teye-Kau, John Hayford G 01 December 2021 (has links)
Concerns about global warming have resulted in a surge of research into alternatives to fossil fuels. In recent years, biofuels have gained traction due to their low environmental impact. Biofuel production most commonly employs microorganisms to convert biomass to fuel for industrial and transportation applications. Compounds made in biofuel production, however, are toxic to cell membranes and disrupt their integrity, harming the microorganisms and limiting biofuel yield. A key to overcoming this challenge is understanding how fuels interact with microorganisms’ cell membranes, which perform a host of functions, including transport, cell recognition, transduction, and movement. Phospholipids are the cell membrane’s building blocks and provide the critical matrix to support these vital functions. This research sought to make in-vitro membrane phospholipid models of the bacterium Bacillus subtilis (a biofuel producer candidate), subject them to fuel stress and employ fluorescence techniques to understand how fuels affect membrane integrity.
24

Vascular Endothelial Cell Senescence Mediated by Integrin β4 in Vitro

Liu, Xia, Yin, Deling, Zhang, Yun, Zhao, Jing, Zhang, Shangli, Miao, Junying 27 November 2007 (has links)
To understand whether integrin β4 is involved in vascular endothelial cell (VEC) senescence, we examined integrin β4 level changes, as well as P53 and reactive oxygen species (ROS) levels and alterations of phosphatidylcholine-specific phospholipase C (PC-PLC) activity before and after knocking-down integrin β4 by small interfering RNA. We found integrin β4, P53 and ROS levels increased significantly, while Ca2+-independent PC-PLC activity obviously decreased during VEC senescence. On the other hand, integrin β4 down-regulation attenuated the senescence phenotype and reversed Ca2+-independent PC-PLC activity, and P53 and ROS levels. The data suggested that integrin β4 might mediate VEC senescence through depressing Ca2+-independent PC-PLC and elevating the levels of P53 and ROS.
25

Phospholipid Flippase Activity and Cellular Function of Class 5 P4-ATPases / クラス5 P4-ATPaseのリン脂質フリッパーゼ活性と細胞内での機能

Naito, Tomoki 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第20305号 / 薬科博第74号 / 新制||薬科||8(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 中山 和久, 教授 竹島 浩, 教授 根岸 学 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM
26

Genetic analysis of methyltransferases involved in choline synthesis of Arabidopsis thaliana

Zulipihaer, Dilixiati 10 1900 (has links)
<p>In plants, S-adenosyl-L-methionine-dependent phospho-base <em>N</em>-methyl transferases catalyze the three sequential methylations of phosphoethanolamine to phosphocholine, the precursor for choline and the major membrane phospholipid phosphatidylcholine. The enzyme phosphoethanolamine <em>N</em>-methyltransferase (PEAMT) catalyzes the first and committing step in choline synthesis, a step for which no known by-pass has been found. In <em>Arabidopsis thaliana</em> there are two loci annotated as encoding PEAMT and a putative PEAMT, At3g18000 (<em>NMT1</em>) and<em> </em>At1g73600 (<em>NMT3</em>), respectively. A related gene product that catalyzes the last two methylations is encoded by locus At1g48600 (<em>NMT2</em>). The objective of this study was to investigate the role of <em>NMT3 </em>in <em>Arabidopsis</em>. Three SALK lines carrying independent T-DNA insertions in At1g73600 were used: SALK_062703, SALK_016929c and SALK_120703c.</p> <p>Genomic DNA was used for PCR and sequence analysis of the products established the insertion of T-DNA in the protein coding region of At1g73600 for all three lines. Gene expression was analyzed by q-PCR. Primer design was particularly important for <em>NMT3 </em>transcript quantification by q-PCR. In SALK_062703 <em>nmt3 </em>mutants, the T-DNA is in exon 8 and in the SALK_120703c line it is in intron 6. In both cases, no <em>NMT3 </em>transcripts were detected using primers that annealed to sites 3’ to the position of the T-DNA in the gene. However, low levels of transcripts were detected using primers that annealed at positions 5’ to the site of T-DNA insertion. In the SALK_016929c line the position of the T-DNA insertion was in exon 2 and primers annealing near the site of the T-DNA insertion showed no <em>NMT3 </em>expression in this mutant but amplifying the mid portion of the gene showed WT levels of <em>NMT3 </em>transcripts. Thus all the mutants produce truncated <em>NMT3 </em>transcripts and by avoiding areas that overlap truncated transcript regions we could differentiate between <em>NMT3</em> knock-out or knock-down expression.</p> <p>Wild-type (<em>NMT3</em>) and <em>nmt3 </em>seedlings from the three lines grown on defined media plates showed no difference with respect to primary root length, number or density of lateral roots, and total root length. Exposing seedlings to salt (50 or 75 mM NaCl) led to reductions in root growth but again, roots of wild-type plants were indistinguishable from the mutant seedlings. One anomaly relates to the <em>nmt3</em> SALK_120703c<em> </em>line which showed two root phenotypes. On saline media most of the seedlings had longer roots that resembled the wild-type and other mutant lines and about a third had shortened roots. Whether the seedlings had long or short roots on salt, they all lacked <em>NMT3 </em>transcripts. This line is likely carrying another insertion that yields a salt-sensitive root phenotype. Mutant plants at four-weeks looked like wild-type plants and time of flowering was not reproducibly delayed or accelerated in mutant plants relative to wild-type.</p> <p>In wild-type seedlings the relative expression level of the three <em>NMT </em>genes is similar at day or night with transcript abundance ranked in the order <em>NMT3</em> > <em>NMT2 </em>> <em>NMT1. nmt3 </em>seedlings harvested midday showed no detectable <em>NMT3</em> expression but the abundance of <em>NMT1 </em>transcripts was 6.2-fold and 1.7-fold higher relative to wild-type in shoots and roots, respectively. At night, <em>NMT1 </em>expression in shoots of<em> nmt3 </em>seedlings decreased 4.8-fold relative to the level of <em>NMT1 </em>expression at midday while transcripts detected in roots increased slightly (1.3-fold). Using SALK_036291 <em>nmt1 </em>seedlings we found that <em>NMT3 </em>expression in shoots and roots was modestly up-regulated in the absence of <em>NMT1 </em>expression and the expression of <em>NMT3 </em>is lower at night than during the day. Also, regardless of the genotype or time of day, <em>NMT2 </em>expression remained constant even when <em>NMT1 </em>and <em>NMT3 </em>transcripts underwent several-fold changes in abundance. Interestingly, four-week old <em>nmt3 </em>plants of the SALK_062703 line showed that <em>NMT3 </em>expression is knocked-out in leaves but only knocked-down in roots.</p> <p><em> NMT3 </em>was the most highly expressed of the three <em>NMT </em>genes monitored by q-PCR. Nonetheless, three independent T-DNA insertion lines defective for <em>NMT3</em> expression were wild-type by appearance and as such, offer compelling evidence that NMT3 is not required by <em>Arabidopsis. </em>The increased expression of <em>NMT1 </em>in <em>nmt3 </em>plants and <em>NMT3</em> in <em>nmt1 </em>plants strongly suggests that plants compensate for the loss of one gene by up-regulating, to varying extents, the expression of the remaining <em>NMT </em>gene. If this is the case, a reasonable prediction made for a cross between <em>nmt1 </em>and <em>nmt3 </em>plants is that it would be lethal unless plants have yet another way to circumvent the loss of an essential enzyme for this committing metabolic bottleneck in choline synthesis.</p> / Master of Science (MSc)
27

The Impact of Dietary Fat and Phosphatidylcholine on Increased Trimethylamine-N-oxide Levels

Ajlan, Reem 26 January 2018 (has links)
Trimethylamine-N-oxide (TMAO) is an important biomarker of atherosclerosis. TMAO is the product of a hepatic conversion of trimethylamine (TMA). Releasing of TMA moieties is dependent on the adaptation of the gut microbiota to dietary TMA containing substrates such as phosphatidylcholine (PC), choline, and L-carnitine. A high-fat diet is an environmental risk factor that may increase TMAO production. However, it isn’t clear if the high dietary intake of TMA is sufficient to promote increased plasma TMAO or if a high-fat intake is also required. We hypothesized that TMAO would be increased after consuming a high-fat diet and a high PC diet independently, with greater increases when consumed together. Four groups of twelve mice each were maintained on different treatments that were either low or high-fat with or without PC over two weeks. Then, a meal containing 9.99 g of corn oil and 0.75 g soybean L-α-Lecithin per 1 kg body weight was provided to all mice to indirectly observe the adaptation of the microbiota to the altered diet. The results of circulating TMAO levels showed that fat appeared to suppress TMAO production, which is against previous evidence. The microbial adaptation to the different treatments wasn’t observed in the measurement of fecal TMA levels. As a result, our hypothesis was rejected. Future work addressing the impact of gene expressions of enzymes on the gut and the liver is needed. The use of another high TMA containing substrates such as choline and rats is recommended. / Master of Science in Life Sciences / Cardiovascular disease (CVD) is heart and blood vessel diseases - many of which are caused by atherosclerosis, a condition wherein fatty materials accumulate in the artery wall, reducing blood flow. The compound trimethylamine-N-oxide (TMAO) was found to be an important biomarker of atherosclerosis. TMAO levels increase in the body when gut microbiota releases trimethylamine (TMA) moieties from dietary phosphatidylcholine (PC), choline, and L-carnitine such as eggs and meat. A high-fat intake was believed to have an impact on increased levels of TMAO. However, it wasn’t clear if the dietary intake of high TMA containing substrates such as PC, is sufficient to promote TMAO formation or if a high-fat content is also required. We hypothesized that TMAO would be increased after consuming a high-fat diet and a high PC diet independently, with greater increases when consumed together. The results would suggest new dietary strategies to avoid CVD. Four groups of twelve mice each were maintained on different treatments that were either low or high-fat with or without PC over two weeks. Then, a meal containing corn oil and PC was provided to all mice to observe the adaptation of the microbiota to the altered diet. The results showed that fat reduces circulating TMAO production, which is against previous evidence. Fecal TMA levels showed that microbiota activities weren’t observed in the colon. As a results, no significant levels of TMA and its precursors were observed in feces.
28

Le rôle de la phosphatidylcholine dans la prévention de la lithiase cholestérolique chez les souris génétiquement susceptibles

Kasbo, Joelle 10 1900 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal. / La formation des calculs biliaires est principalement due à la précipitation des cristaux de cholestérol de la bile sursaturée en cholestérol et à la présence des agents pro- ou antinucléants. De plus, il est établi que la génétique et la diète contribuent grandement à ce phénomène. La supplementation de la diète en phosphatidylcholine (PC) améliore la fonnation de la bile en augmentant le transport maximal des acides biliaires et la sécrétion des lipides biliaires. Les phospholipides sont importants pour maintenir la solubilité du cholestérol dans la bile et le tiers de la PC biliaire origine de la PC de la diète. L'objectifde cette étude est de tester l'effet d'une supplementation de la diète en PC sur l'incidence des calculs biliaires de cholestérol. Pour ce faire, des souris C57BL/6J, génétiquement susceptibles à la formation des calculs biliaires de cholestérol lorsque nourries avec une diète lithogénique (contenant 1% de cholestérol et 0,5% d'acide cholique), ont été utilisées. Un premier groupe a reçu la diète lithogénique et un second groupe la diète lithogénique enrichie à 2 ou 6% en PC. Les résultats ont montré que la supplementation en PC à 2% retarde la formation de calculs biliaires de cholestérol. Ceci a été associé avec une réduction de l'mdice de saturation en cholestérol et avec une augmentation significative de la concentration de la protéine antinucléante hépatique (APF). Cependant, l'augmentation de la supplementation à 6% en PC, prévient complètement la formation de calculs biliaires de cholestérol et ceci par une réduction significative de l'indice de saturation de la bile hépatique en cholestérol et par l'augmentation significative du flux biliaire et de la sécrétion biliaire des acides biliaires et des phospholipides. En conclusion, la supplementation en PC a un effet bénéfique sur la prévention de la formation des calculs biliaires de cholestérol chez les souris génétiquement susceptibles à la lithiase cholestérolique.
29

Untersuchungen zur Entstehung, Lokalisation und Wirkung von fragmentiertem Phosphatidylcholin (FPC) im Menschen

Frey, Bettina 14 December 2000 (has links)
Oxidativ modifizierte Phospholipide haben PAF-ähnliche Struktur und zeigen in vitro PAF-ähnliche Wirkung. Dabei handelt es sich hauptsächlich um fragmentierte Phosphatidylcholine, die eine lange Fettsäure- oder Alkylkette in sn-1 Stellung und einen kurzen Acylrest (C4-C9) mit oxidiertem C-Atom in sn-2 Stellung haben und als PAF-ähnliche Lipide bezeichnet werden. In der vorliegenden Arbeit wurden durch eine neue HPLC-Fluoreszenzmethode ein Vertreter dieser in vivo existierender PAF-ähnlichen Lipide im Plasma quantifiziert. Dieses fragmentierte Phosphatidylcholin (FPC) besitzt einen Palmitoylrest in sn-1 Position, sowie eine C3 oder C4 Kette in sn-2 Position und erfüllt damit die strukturelle Voraussetzungen für biologische Aktivität. Weiterhin konnte gezeigt werden, dass FPC in biologisch aktiven Fraktionen enthalten war, deren biologische Aktivität jedoch nicht von PAF bewirkt wurde, sondern von PAF-ähnlichen Lipiden. Dies unterstützt die Vermutung, dass FPC biologische Aktivität zeigt. Im Plasma wird FPC von Lipoproteinen transportiert. Oxidativer Stress in biologischen Systemen, ausgelöst durch Tabakrauch, Organischämie/ Reperfusion, Vitamin E-Mangel oder Inkubation von Zellen mit H2O2, führte zu einer Erhöhung der FPC-Konzentration. Damit wurde gezeigt, dass die PAF-ähnlichen Lipide in vivo durch Radikal-induzierte Lipidperoxidation gebildet werden können. Trotz eines Konzentrationsanstiegs von FPC nach oxidativem Stress, kam es bei einer systemischen Inflammation, die von Radikal-bildenen Prozessen begleitet ist, jedoch nicht zu einer Anreicherung von FPC-ähnlichen Lipidperoxidationsprodukten. Ursache für die fehlende Anreicherung von oxidativ modifizierten Lipiden bei einer systemischen Inflammation könnte ihr rascher Abbau durch Phospholipasen, oder der Abbau von Vorstufen, bzw. die Substratrminderung, sein. / Oxidative modified phospholipids have PAF like structure and show in vitro PAF like activity. They consist of fragmented phosphatidylcholine with a long fatty acid or alkyl chain in sn-1 position and a short acylrest (C4-C9) with a oxidized C-atom in sn-2 position. According to their structure they are called PAF like lipids. In this paper one representative of these in vivo existing PAF like lipids are quantified in plasma by means of a new fluorescence HPLC method. These fragmented phosphatidylcholines consits of a palmitoylrest in sn-1 position and a C3 or C4 chain in sn-2 position and therefore they fullfill the strutural conditions to have biological activity. We further showed, that the biological active fractions contain FPC. The biological activity is not caused by PAF but by PAF like lipids. This fact supports the hypothesis that FPC are biological active. FPC is carried by lipoproteins in plasma. Oxidative stress caused by cigarette smoke, ischemia/ reperfusion, Vitamin E deficiency or incubation of cells with H2O2 leads to an increase of the concentration of FPC. Thereby it could be shown that PAF like lipids can be formed in vivo by means of radical induced lipidperoxidation. Many radical producing processes are involved in systemic inflammation. Despite of an increase of FPC's concentration after oxidative stress, there was no accumulation of FPC like lipidperoxidation products during systemic inflammation. One reason for the missing accumulation of oxidative modified lipids during systemic inflammation can be the fast degradation by phospholipases or the reduction of substrat.
30

Improving Caco-2 cell permeability assay using phospholipid covered silica beads

Faradj, Lana January 2021 (has links)
The Caco-2 cell assay is widely used for in vitro permeability measurements. However, a draw back with the assay that this study will focus on improving, is compound adsorption to the plastic material. Lipophilic compounds such as Cyclosporin A and Peptide J, that will be used in this study, tend to bind to the plastic material in the assay. This can result in poor recovery and misleading permeability predictions. Bovine serum albumin (BSA) is an alternative used today to prevent this but is not always successful.    The aim of this study is therefore to improve the Caco-2 permeability assay by adding phospholipid covered silica beads (PLB) to the basolateral chamber. The role of the PLB is to bind the compound of interest and decrease the amount of compound bound to the plastic material and thus better predict the permeability of the compound of interest.   The PLB was produced using phosphatidylcholine and silica beads. Caco-2 cells were seeded and maintained for 21-29 days ahead of the experiment. PLB concentration of 20, 60 and 100 mg/ml were prepared. Samples were analyzed with HPLC-MSMS. The results showed that with increasing PLB concentration we had a significantly decrease in non-specific plastic binding resulting in reliable permeability predictions, concluding that the hypothesis was correct.

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