Dissertations / Theses on the topic 'Albumen'
To see the other types of publications on this topic, follow the link: Albumen.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Albumen.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Roeske, Alison. "The albumen muse." Diss., Online access via UMI:, 2005.
Find full text
2
Durance, Timothy Douglas. "Isolation of avidin and lysozyme from egg albumen." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27297.
Full textAbstract:
A single column cation exchange method was developed which allowed simultaneous recovery of lysozyme and avidin from undiluted egg white using a unique elution sequence which involved accumulation of avidin on the column through several cycles of egg white application and lysozyme elution. Lysozyme was recovered with higher yields than reported for the isoelectric precipitation methods often used in the industry (86% vs 60 - 80%) and in high purity. Avidin recovery was also as good or better than that of previously reported ion exchange methods (74 - 80% vs 17 -80%). The purity of the avidin fraction (up to 40.9%) was superior to other reported primary avidin fractions. Avidin was shown to have a greater potential for both electrostatic and hydrophobic interactions with Duolite C-464 than lysozyme but under the conditions of this separation, electrostatic interactions were dominant.
Secondary purification of avidin by carboxymethyl celluose cation exchange (CMC), gel filtration, metal chelate interaction chromatography (MCIC), aliphatic hydrophobic interaction chromatography (HIC), and Phenyl-Sepharose interaction chromatography (PSIC) each resulted in considerable increase in avidin purity. In terms of resin capacity, yields, and avidin purity however, CMC ion exchange was superior. A comparison of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) andnative protein electrophoresis profiles gave clear evidence of protein - protein interaction between avidin and lysozyme in partially purified avidin preparations. This interaction may also occur between the native proteins in the egg white, but has not been demonstrated with certainty.
The molar ratio of avidin to available biotin binding sites was estimated by 5 methods. For highly purified avidin samples the hydroxy azo benzoic acid (HABA) method proposed by Green (1965) was superior. A new method, utilizing an immobilized biotin column, which did not require extensive purification of avidin was found to give similar results.
Finally, a highly sensitive assay of proteins bound to nitrocellulose membranes was developed which was capable of quantifying as little as 0.12 µg of protein. Membrane bound proteins were labeled with peroxidase via a biotin - avidin linkage as previously reported and bound peroxidase activity was related to initial protein content. The method was applicable to determination of the relative concentrations of different protein bands on Western blots of electrophoresis gels.Land and Food Systems, Faculty of
Graduate
3
Wang, Guang. "Phospholipids oxidation and foaming enhancement of egg albumen." [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3389160.
Full text
4
Tchamo, Pierre. "Sélection de maïs (Zea mays L. ) à albumen tendre et résistant au streak, étude des caractères correlés au facteur albumen tendre ou dur." Paris 11, 1987. http://www.theses.fr/1987PA112153.
Full textAbstract:
Le maïs constitue J'un des principaux aliments de base de la population de l'Est du Cameroun où toute la production maïsicole est faite par des paysans qui pratiquent une agriculture de subsistance. Parmi les facteurs qui limitent le rendement du maïs dans cette région, le streak (maladie virale transmise par un insecte du genre cicadelle) est l'un des plus importants. On a utilisé la méthodologie de la sélection récurrente pour sélectionner deux populations de maïs (l'une à albumen tendre et l'autre à albumen dur) pour la résistance contre le streak. En cas d'épidémie de steak les variétés résistantes ont une récolte normale alors que la récolte est presque nulle pour les variétés sensibles. La population à albumen tendre permet dans les conditions de culture traditionnelles d'avoir un gain de rendement d'environ soixante-dix pour cent par rapport à la variété locale non améliorée. Les corrélations entre caractères ont été étudiées dans les deux populations à albumen tendre et dur afin de rechercher les groupes de caractères liés à la qualité du grain. Certains de ces caractères tels que la longueur de l'épi et le diamètre de l'épi sont d'une part très fortement corrélés entre eux indépendamment du génotype et d'autre part très liés au rendement. Les caractères longueur de l'épi 1 longueur de la feuille et nombre de rangées de grains sont corrélés au facteur albumen tendre. Ces corrélations sont probablement d'ordre génétique. Des hypothèses tendar. T à les situer dans un linkat ont été émisesMaize is one of the principal staple foods of the population of the Eastern Cameroon where all maize production is produce by subsistance farmers. Among the factors that limit maize yield in this area, streak (A viral disease transmitted by a specific insect vector of the genus Cadulina) is one of the most important. Two maize populations (the first one with a soft endosperm and the second one with a hard endosperm) were selected for streak resistance using recurrent selection methodology. Ln cases of streak epidemy, these resistant varieties give a normal production whereas the production of the sensitive varieties is nearly null. Ln the traditional cultural conditions, the soft endosperm population out yields the unimproved local variety by seventy per cent. Correlations between characters were studied in the two populations with soft or hard endosperm to search groups of characters linked with grain quality. Some of these characters such as ear length and ear diameter are on one hand very highly correlated to each other independently of their genotype, and on the other hand very correlated with yield. Ear length, leaf length and kernel row number are correlated with soft endosperm factor. The origin of these correlations is probably genetics. Hypotheses on linkage situations are proposed
5
Tchamo, Pierre. "Sélection de maïs (Zea mays L.) à albumen tendre et résistant au streak étude des caractères corrélés au facteur albumen tendre ou dur /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb376102333.
Full text
6
Begum, Ferdausi. "Proteomic measures of albumen degradation as indicators of egg freshness." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/25678.
Full textAbstract:
With prolonged storage especially at elevated temperatures, thick albumen deteriorates as it loses its viscous characteristics and this is regarded as a sign of reduced egg freshness and quality. Currently, HU is a widely used procedure for determining albumen quality. Proteomic analysis of egg albumen changes could provide a comprehensive understanding of egg freshness and used to assess egg quality during storage and processing. A core objective of this research was to identify and quantify proteins that change during albumen degradation with the potential to identify novel biomarkers of egg freshness and quality. The first efforts of identifying the protein changes in albumen used 2D-PAGE. The changes in albumen proteins were obvious after just 7d of storage at room temperature and this fitted with the more pronounced changes observed using conventional measures of egg quality. The N-TAILS approach to identifying protein changes in egg albumen was instigated and a number of antibacterial proteins were identified. Lysozyme C was identified in all samples. Lysozyme C changes associated with albumen degradation provides a potential biomarker of albumen quality and by association egg aging. The second objective of the project was to evaluate egg quality from different production systems. In retrospect, such an evaluation would have little relevance if some of the other factors such as hen age, ambient temperature and acute stress, could not be accounted for. After accounting for these there was no differences in the deterioration of egg quality during storage at commercial cool room conditions for eggs collected from free range or conventional cage production systems.
7
Eskandrani, Areej. "Antioxidant and antiotensin converting enzyme inhibitory activities of egg albumen proteins." Thesis, University of Surrey, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658625.
Full textAbstract:
The present study investigated the in vitro antioxidant and ACE-inhibitory activities of egg albumen hydrolysate (EAR) prepared with pepsin and pancreatin enzymes. The EAR and peptides were purified by ultrafiltration (UF), gel filtration (GF), and High Performance Liquid Chromatography (HPLC) and tested for" antioxidant and ACE-inhibitory activities. Antioxidant activity was assessed by lipid peroxidation inhibition in a linoleic acid system using the ferric thiocyanate (FTC) and thiobarbituric acid reactive species (TBARS) methods. The EAR, and 2, 5 and 10 kDa UP fractions, as well as the GF26 peptide fractions (I mg/ml) inhibited linoleic acid autoxidation, by 40, 76, 63, 53 and 79 % respectively, which was inversely related to peptide fraction size. However, 0.01 % butylated hydroxytoluene (BHT) and 0.01 % trolox had higher activity (95 and 82 %, respectively) compared with the peptide fractions (p<0.05). Similarly, inhibition of TBARS was in the order 29, 39, 27, 17, 70 and 78 % for EAR, 2 kDa, ' 5 kDa, 10 kDa, trolox and BHT respectively. The putative antioxidant mechanism of EAR involved scavenging activity based on the I, l-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (OH") and superoxide anion (02") radical scavenging assays, and ferric (Fe3+) reducing and ferrous (Fe2+) ion chelating activities in a dose-dependent manner. All peptide fractions exhibited ACE-inhibitory activity, based on the ACE-catalyzed liberation of hippuric acid from the hippuryl-L-histidyl-L-Ieucine residue, which improved on further GF and HPLC purification. The 2, 5 and 10 kDa peptides exhibited % ACE inhibitory activities of 78, 71 and 62 %, respectively, compared to the positive control captopril (96 %). The 2, 5 and 10 kDa peptides had ICso values of 6.01, 6.86 and 7.93 mg/ml respectively. Further, GF and HPLC purification of the 2 kDa peptides improved the ICso values to 5.76 and 5.13 mg/ml, respectively. Cell viability of human colon carcinoma mono-layer (caco-2) cell line, assayed by the tetrazolium dye (MTT) colorimetric assay confIrmed that the 2 kDa peptides were not toxic. The 2 kDa peptides (0.1 mg/ml) reduced most of the endogenous antioxidant enzyme activities in a dose-dependent manner, indicating scavenging of ROS. It was evident that a significant proportion of the 2 kDa peptides were resistant to cellular aminopeptidases present in caco-2 cell epithelium and were therefore transported in their intact forms across the caco-2 cell epithelium. In addition, The 2 kDa peptides exhibited significant ROS scavenging activity evidenced by enhanced viability of the Ea.hy926 (HUVECs) cell lines, using the lucigenin-enhanced chemiluminescent and fluorescence methods. The results confirm that bioactive peptides derived from the EAH have significant antioxidant and ACE·inhibitory activities and potentially useful neutraceutical applications.
8
Taylor, Claire E. "Functional aspects of chemically modified bovine blood plasma and egg albumen proteins." Thesis, University of Surrey, 1988. http://epubs.surrey.ac.uk/785/.
Full text
9
Toussant, Matthew J. "Studies of egg albumen quality : the effects of dietary vanadium and ascorbic acid, genetics, and avian infectious bronchitis virus vaccination on albumen composition and other relationsips with egg production parameters /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487846885779791.
Full text
10
Markiv, Anatoliy. "Identification, cloning and functional characterisation of lectinsfrom the albumen gland of the Roman snail Helix pomatia." Thesis, University of Westminster, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502237.
Full textAbstract:
The lectin from the albumen gland of the Roman snail Helix pomatia has been widely used in studies relating glycosylation changes to the metastatic potential of cancer cells. Detailed information related to the sequence, structure and binding site of HPA lectin would assist in identifying the HPA binding partners on cancer cells. Availability of a recombinant form of HPA has the potential to be developed as a diagnostic tool for cancer prognostication. The work embodied in this thesis includes characterisation of the lectin from the albumen gland of Helix pomatia with the goal of obtaining an insight into the identity of the carbohydrate-binding partners on the membrane of cancer cells and producing a recombinant form of this lectin for diagnosis of metastatic cancer. For this purpose the study first identified the amino acid sequence of the HPA lectin, this was cloned into Escherichia coli with a view to obtaining a crystal structure of the agglutinin and its carbohydrate-binding site, to functionally analyse the carbohydratebinding properties of the recombinant lectin and allow comparison with the native material. A comparative analysis of in-house purified HPA and commercially sourced material provided evidence of heterogeneity in the agglutinin preparation. MS/MS analysis of the protein separated by isoelectrofocussing showed that more than one polypeptide sequence was present in the protein sample known as HPA. The cloning and identification of HPA lectin showed that three separate protein sequences were present in the lectin purified from the albumen gland of the Roman snail Helix pomatia. Two of the polypeptides are consistent with GalNAc binding lectins of the H-type family and were termed HPAI and HPAII. The third lectin (HPAIIJ) showed sequence similarity to a sialic acid binding lectin from another snail Cepaea hortensis and structural analysis of the novel protein suggests it will form a C1 q/TNF ' . like fold. The genes for all three polypeptides were cloned and recombinant forms of the proteins were prepared. Different expression plasmid constructs were evaluated. The results provide the first demonstration of successful cloning and expression of all three recombinant forms of the HPA isolectins using an E. coli expression system. A combination of crystal structure analysis and molecular modelling of the GalNAc/GlcNAc binding isolectins (HPAI and HPAII) from Helix pomatia has led to the identification of amino acids participating in direct hydrogen bonding with the carbohydrates and also amino acids involved in lectin trimer formation via noncovalent bonding. Functional analysis of HPAI and HPAII using surface plasmon resonance provided information on the affinity of binding of native and recombinant material to GalNAc/GlcNAc carbohydrates attached to bovine serum albumin. The interactions were observed to be of the same order of magnitude for both native and recombinant material. Glycan chip microarray studies showed that recombinant HPAI and HPAII recognised similar binding partners to native HPA and agglutination studies showed that the recombinant forms of the HPAI and HPAII isolectins were functional in clumping blood group A red blood cells. The recombinant forms of the lectin produced in this study are valuable tools for Glycobiology studies to analyse changes in the posttranslational glycosylation in normal and cancer cells as detected using HPA. The recombinant lectins may also be used in microbiology, serology and other glycome analyses. Structural information on the carbohydrate-binding site of the HPA lectins may later be used to identify their binding partners on the membrane of malignant cells and this might in turn lead to a better understanding of changes in glycosylation that governs the metastatic potential of cancer cells.
11
Scheppokat, Angela Michelle. "Efficient enzymatic syntheses of L-fucosylated and D-galactosylated oligosaccharides using glycosyltransferases from Helix pomatia albumen glands." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=967059011.
Full text
12
Webber, Witt Manuella [Verfasser]. "The allergic potential arising from proteinous wine fining agents of milk and chicken egg albumen / Manuella Webber Witt." Gießen : Universitätsbibliothek, 2015. http://d-nb.info/1068922443/34.
Full text
13
Norre, Frédéric. "REGULATION TRANSCRIPTIONNELLE DU PROMOTEUR HMWG-DX5 DE BLE DANS L'ALBUMEN DE MAÏS ET CREATION DE PROMOTEURS CHIMERIQUES." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2002. http://tel.archives-ouvertes.fr/tel-00371477.
Full textAbstract:
La région promotrice proximale du gène Glu-1D1 de gluténine de haut poids moléculaire de blé (PrHMWG-Dx5) porte une boîte albumen bifactorielle atypique qui comprend un motif G " like " (5'-TTACGTGG-3') situé en amont d'une boîte prolamine (Pb1, 5'-TGCAAAG-3'). Les tests d'expression transitoire dans l'albumen de maïs indiquent que le fragment promoteur minimal contenant au moins la boîte G " like " est nécessaire et suffisant pour une activité maximale de PrHMWG-Dx5. Dans le maïs transgénique, nous avons montré que la séquence de 89 pb qui contient la boîte albumen bifactorielle se comporte comme une unité cis-activatrice fonctionnelle. Sa répétition en tandem direct confère un effet activateur additif puissant spécifique de l'albumen. En contraste, l'association des séquences activatrices as-1 et as-2 du promoteur 35S du CaMV avec des séquences promotrices dérivées de PrHMWG-Dx5 dérégule son activité dans les plants de maïs et de tabac. Par la technique de retard de migration, nous avons démontré que la boîte G " like " peut fixer deux groupes de protéines qui ont respectivement la même affinité de liaison à l'ADN que les facteurs de transcription de la famille Opaque-2 et de la famille ASF-1. Nos résultats nous conduisent à proposer un modèle hypothétique qui repose sur une dualité fonctionnelle de la boîte G " like " dans l'albumen des céréales, et suggère son implication potentielle alternativement dans la synthèse des protéines de réserve et dans la réponse de défense de la plante.
14
Akintoye, Olumuyiwa Adetokunbo. "The effect of micro- and macro-molecules on the microstructure and gel characteristics of whey protein concentrate and albumen." Thesis, University of Leeds, 2007. http://etheses.whiterose.ac.uk/15215/.
Full textAbstract:
Avian egg albumen and whey protein concentrates from milk are widely used in the food industry as binder systems, emulsifiers, and foaming agents and for general consumption. In meat-like analogues such as Quom, the whey protein concentnite and egg albumen are relied upon to produce tough gels with the application of heat. Like many food products, the heat-inauced gelation of the protein molecules depend on the environmental conditions and other materials present in the system as well as any interactions between them. A study of a range of ingredients as well as environmental the factors of pH, material concentration and various blends of whey protein concentrate and albumen was initiated in the hqpe, of quantifying the effect of the materials on gel structure. Texture Profile Analysis (TPA) , stress relaxation, protein gel dissolution, ' colour measurement and confocal laser scanning microscopy (CLSM) were employed to assess, measure and quantify the relationships between the environmental factors and the added materials. The results obtained indicated that whey protein 'and albumen form an interpenetrating gel under normal conditions. The optimum ratio at which the combined binder exhibited it maximum values was of the order of 2:1 (whey/albumen). The pH'of the, media had the biggest effect on the gel properties. Alteration' in pH close to 'the isoelectric point changes the gel from a fine-stranded network to one with a particulate or filamentous network. Significant interactions were observed between all the main variables on at least one of the responses. Addition of hydrocolloids with large molecules in relation to the protein such as methylcellulose and pectin led to phase separation. Methylcellulose induced' a change in the gel from one that imbibed water to one that exuded water as the concentration of the material was increased up to 2%. With high methoxyl pectin, there was phase separation at pectin concentration of as little as 0.5% and phase inversion at pectin concentration in excess of 0.5%. The starch products generally delivered the largest incret;Jse in the gel hardness, but there were changes to other gel properties depending on what type of starch was used. Milk-derived ingredients such as lactose, casein and glycomacropeptide (GMP) were not necessarily compatible with a whey protein/albumen gel. Dissolutions tests with protein perturbing agents such as DTE, SDS and urea showed that some of the added materials interfered with protein'-protein gel formation by one of two ways (1) by blocking· the formation of the bonds necessary to stabilize the protein structure and/or (2) interacting with the water molecules in ' preference to the protein molecules. In addition the CLSM micrographs proved that there was indeed phase separation of the molecules when the conditions were not favourable.
15
March, Alan Charles. "Computer automation of a novel ion-exchange process for the simultaneous recovery of lysozyme and avidin from chicken egg albumen." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29660.
Full textAbstract:
A three-column ion-exchange system was designed, fabricated and computer-automated to accommodate a novel 'elution looping' process developed by Dr. Tim Durance (U.B.C. Department of Food Science) during his doctoral studies on the recovery of lysozyme and avidin. This processing technique enhances the simultaneous recovery of these two pharmaceutically important proteins from chicken egg albumen. The processing system prototype was sized to handle throughput rates between approximately five and 300 liters per day of albumen to facilitate both laboratory and small commercial scale work. Very efficient use is made of the ion-exchange resin due to a two-column cascaded feed arrangement.
The processing control software was designed to provide flexibility and ease of operation in setting up new and existing method files, allowing for the selection of any column or group of columns to use and providing a 'staged-shutdown' approach toward handling columns fouled with congealed albumen during unattended operation. This approach attempts to maximize the productivity of the system even when one or two of the columns has become fouled with congealed albumen.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
16
Bedrani, Larbi. "Modulation de l'immunité innée moléculaire de l'oeuf." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR4008/document.
Full textAbstract:
L’œuf est un aliment riche en divers composés dont de nombreuses molécules antimicrobiennes qui sont les effectrices de son système de défense moléculaire innée et complètent l’action des immunoglobulines (IgYs) afin de protéger l’embryon. La composition en IgYs de l’œuf est sous la dépendance notamment des stimulations microbiennes de la poule. L’objectif de notre travail a été d’évaluer l’influence de ces mêmes stimulations sur le système de défense moléculaire innée du blanc d’œuf. Nous avons exploré cette hypothèse en utilisant deux approches expérimentales. La première était basée sur la comparaison de l’activité antibactérienne des blancs d’œufs de poules axéniques, de poules exemptes d’organismes pathogènes spécifiques (EOPS), et de poules conventionnelles. La seconde approche a testé les effets de deux types d’inductions du système immunitaire chez la poule: injection d’un immunostimulant, le lipopolysaccharide bactérien (LPS) et administration oral de souches vaccinales atténuées (virale, bactérienne et parasitaire). Nos résultats montrent que l’activité antibactérienne du blanc d’œuf est augmentée en fonction de la charge microbienne du milieu de vie de la poule, après stimulation de celle-ci par voie intraveineuse avec du LPS ou suite à la vaccination avec des souches atténuées virale ou bactérienne. Néanmoins cette augmentation est modérée de par son amplitude et son spectre antibactérien. Ces résultats suggèrent que les poules peuvent renforcer modérément l’activité antimicrobienne du blanc d’œuf en réponse à des stimuli microbiens de leur milieu et anticiper ainsi les besoins de l’embryon en termes de protectionThe egg is a balanced source of different nutrients and contains a myriad of antibacterial peptides/proteins that ensure its chemical protection. These molecules are a part of its innate molecular defense and, in addition to the maternal immunoglobulins IgY, contribute to the protection of the forming embryo whose development occurs ex utero. It is well documented that yolk immunoglobulin deposition is induced by the environmental microbiome of the hen but no such evidence is available for antimicrobial peptides/proteins. Therefore the aim of this thesis was to assess whether the hen has the ability to stimulate the innate molecular immunity of the egg white when facing a higher environmental microbial load (commensal or pathogenic). To address these questions, we developed two main experimental approaches; the first assessed the impact of the hen environmental microbial load through the comparison of three groups of hens with different immune status:-Germ free, -Specific pathogen free (SPF), and -conventional. The second approach explored the effect of different types of immune stimulation in hens: non-infectious stimulation (systemic injection of bacterial lipopolysaccharide (LPS)); immune stimulation using attenuated live vaccines (Infectious bronchitis virus vaccine, Salmonella enterica Enteritidis vaccine and a complex of Eimeria vaccine). Our results show that the activity of egg white is increased in response to higher microbial environmental charge, after LPS systemic stimulation or after vaccinating hens with live attenuated viral and bacterial strains. However this response is moderate both in its amplitude and microbial spectrum. Altogether, it appears that hens when subjected to immune stimuli, have the ability to reinforce moderately the antibacterial activity of the egg white as an attempt to anticipate the need of protection of their embryos
17
Kim, Jonghan. "Pharmacokinetics and pharmacodynamics of protein turnover and production in vivo." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1100554543.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xxi, 203 p.; also includes graphics. Includes bibliographical references (p. 191-203).
18
Souza, Janaina Cristina da Silva Maciel de. "Níveis dietéticos de metionina e cobre quelatado, treonina e zinco quelatado sobre a composição química do ovo e o teor de colesterol da gema." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-23022018-122854/.
Full textAbstract:
Na avicultura de postura, a associação dos aminoácidos e minerais quelatados pode afetar positivamente a composição química dos ovos e o colesterol da gema. Desta forma, em dois ensaios experimentais distintos, objetivou-se com avaliar a interação do nível dietético de metionina e cistina com o cobre quelatado e treonina e zinco quelatado sobre a composição química do ovo. Para tanto, foram utilizados em cada ensaio 320 poedeiras comerciais, distribuídas sob o delineamento inteiramente casualizado. Os tratamentos, distribuídos aleatoriamente em quatro repetições, foram organizados em arranjo fatorial 5 x 4: sendo o primeiro fator teor de aminoácido e o segundo nível do mineral quelatado, constituindo 20 tratamentos, com quatro repetições e quatro aves por unidade experimentais. A parcela experimental era constituída de quatro aves com 48 semanas de idade. No primeiro ensaio os níveis totais de metionina+ cistina (met+cys) eram: 0,613, 0,631, 0,816, 0,918 e 0,955 % e os de cobre (Cu): 18, 44, 71 e 99 mg / kg. No segundo, eram: níveis totais de treonina (Thr) 0,614, 0,698, 0,875, 1,006, 1,055%; e. zinco (Zn): 31, 73, 104 e 121 mg / kg. Os níveis avaliados foram estabelecidos após análises laboratoriais. Em ambos os experimentos, foram avaliados: ovos e conteúdos, taxas diárias de deposição, composição química dos conteúdos na Matéria Natural (MN) e Matéria Seca (MS). Para as determinações da composição química PB%, EE%, MM%, H2O% e colesterol dos ovos, foram colhidos dois ovos por parcela. Os dados foram analisados utilizando-se o procedimento SISVAR 5.6 e o nível de significância considerado foi de 5%. No ensaio 1, o efeito de interação (P < 0,05) entre Met + Cys*Cu, foi observado para maioria das variáveis avaliadas. Entretanto, foram observados efeito principal (P < 0,05) de Met+ Cys para as seguintes variáveis: peso de casca e gema; deposição de Nitrogênio (N), Extrato Etéreo no Albúmen (EE no Alb) e Cinzas, composição química do ovo nas Matérias Natural e Seca; Proteína Bruta (PB), Extrato Etéreo (EE) e Cinzas no Albúmen, ovo reconstituído e MS no Alb, e para colesterol total. O efeito do aumento nos níveis de Met + Cys resultou em acréscimo de 18,17 % no teor de colesterol. Ensaio 2: Foi observado efeito de interação (P <0,05) entre Thr* Zn, para maioria das variáveis analisadas. Todavia, foi observado efeito principal (P< 0,05) do aminoácido para as seguintes variáveis: pesos de casca e gema, na composição química do ovo na MN (EE na gema), onde o aumento nos níveis de Thr resultaram no aumento do EE na gema, para o colesterol total. Conclui-se que em ambos os experimentos a utilização mineral quelatado em dietas para poedeiras pode trazer benefícios para qualidade do ovo, melhorando alguns parâmetros da composição química do ovo.In laying hens production, an association of amino acids and chelated minerals can positively affect a chemical composition and yolk cholesterol.of the eggs. Thus, the objective was to evaluate the interaction of the dietary level of methionine and cystine with the chelated copper and chelated threonine and zinc on the chemical composition of the egg, in two different experimental trials. For this, 320 commercial layers were used in each experiment, distributed under a completely randomized design. The treatments, were randomly distributed in four replications, in a 5 x 4 factorial arrangement of treatments, with five levels of the factor amino acid content and four levels of the factor chelated mineral concentration, constituting 20 treatments, with 4 replicates and 4 layers per experimental unit. The experimental plot consisted of four birds with 48 weeks of age. In the first trial, the total methionine + cystine (Met + Cys) levels were: 0.613, 0.631, 0.816, 0.918 e 0.955% and cooper (Cu): 18, 44, 71 e 99 mg / kg. In the second trial, the total threonine (Thr) levels were: 0.614, 0.698, 0.875, 1.006, 1.055%, and zinc (Zn): 31, 73, 104 e 121 mg / kg. The levels assessed were established after laboratory analysis. In both experiments, were evaluated: eggs and contents, daily rates of deposition, chemical composition of contents in natural matter (NM) and dry matter (DM). For the determinations of the chemical composition (PB%, EE%, MM%, H2O% and cholesterol of the eggs), two eggs were collected per plot. Data were analyzed using the SISVAR 5.6 procedure and the level of significance considered was 0.05. Experiment 1: the interaction effect (P < 0.05) between Met + Cys*Cu was observed for most of the evaluated variables. However, the main effect of Met + Cys was observed (P < 0.05) for the following variables: egg shell and yolk weight; deposition of nitrogen (N), ether extract (EE) in albumen and ash; chemical composition of the egg in natural and dry matter (CP, EE and Ash in the albumen, reconstituted egg and DM in albumen) for the total cholesterol. The effect of the increase in a Met + Cys levels resulted in an increase of 18.17% in the cholesterol content. Experiment 2: the interaction effect (P < 0.05) between Thr* Zn was observed for most of the observed variables. However, the main effect (P < 0.05) of the amino acid was observed for the following variables: egg shell and yolk weights, in the chemical composition of the egg in the NM (EE yolk), where the increase in Thr levels resulted in increased of yolk EE, Therefore, it is concluded that in both experiments the chelated mineral utilization in laying diets can bring benefits to egg quality, improving some parameters of the egg chemical composition.
19
Silva, Mayra Fernanda Rizzo. "Desempenho, qualidade dos ovos e balanço de nitrogênio de poedeiras comerciais alimentadas com diferentes níveis de proteína bruta, metionina e lisina." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-01092006-101659/.
Full textAbstract:
Foram conduzidos dois experimentos com um total de 416 poedeiras Hisex White, com os objetivos de avaliar os efeitos de diferentes níveis dietários de proteína bruta (PB) e de lisina (LIS) sobre as características de desempenho, qualidade interna dos ovos e determinar o balanço e o coeficiente de metabolizabilidade aparente do nitrogênio (Experimento 1) e avaliar os efeitos de diferentes níveis dietários de LIS e metionina (MET) sobre o desempenho, qualidade interna dos ovos e propriedades funcionais dos componentes dos ovos (Experimento 2). No Experimento 1, foram utilizadas 160 poedeiras alojadas individualmente e submetidas ao delineamento inteiramente casualizado (DIC) em esquema fatorial 4 x 2, com os fatores: níveis de PB (12%, 14%, 16% e 18%) e de LIS (0,85% e 1,00%), totalizando oito tratamentos com cinco repetições de quatro aves cada. No Experimento 2, foram utilizadas 256 poedeiras alojadas individualmente e submetidas ao DIC em arranjo fatorial 4x4, com os fatores: níveis de LIS (0,482%, 0,682%, 0,882% e 1,082%) e de MET (0,225%, 0,318%, 0,411% e 0,505%), totalizando 16 tratamentos com quatro repetições de quatro aves cada. O desempenho foi avaliado por meio das características consumos de ração (CR), lisina (CLIS), metionina (CMET), proteína bruta (CPB) e de energia (CE), peso (PO), produção (PROD) e massa de ovos (MO), e conversão alimentar (CA). As características CPB, PO e MO tiveram respostas linear crescente. A qualidade interna dos ovos foi avaliada por meio das características peso e porcentagens de albúmen (ALB%) e gema (GEM%), e unidade Haugh (UH). A ALB% apresentou diferença significativa com resposta linear crescente. Em ambos experimentos, a qualidade dos ovos armazenados foi mensurada pelas características UH, PO e altura de albúmen, as quais apresentaram melhores resultados quando os ovos foram conservados em ambiente refrigerado. No entanto, independente do ambiente, a qualidade dos ovos piorou com o aumento do tempo de armazenamento. Respostas máximas das análises de proteína, sólidos totais, viscosidade e pH dos componentes albúmen e gema, foram obtidas quando as aves foram alimentadas com a concentração média de 15,33% de PB na dieta. No Experimento 1, após o término do período experimental foram realizadas coletas das excretas por um período de três dias para cálculo do balanço de nitrogênio, sendo observado aumento significativo da ingestão e excreção de nitrogênio conforme o incremento de PB na dieta. No experimento 2, as características CR, CMET, CE, PROD, PO e MO apresentaram resposta máxima quando as aves foram alimentadas com as concentrações dietárias médias de 0,870% de LIS e de 0,450% de MET. A classificação dos ovos por tipo e as características de qualidade interna e externa dos ovos não sofreram influência dos diferentes níveis dietários de MET e LIS. As propriedades funcionais dos componentes albúmen e gema foram avaliadas por meio da qualidade do cozimento com a confecção de bolos tipos Angel e Sponge cakes, a qual não foi influenciada pelos tratamentos. Conclui-se que níveis médios de 15,33% de PB, 0,450% de MET e 0,870% de LIS satisfazem as exigências das poedeiras para as características avaliadas.Four hundred sixteen Hisex White hens were used to evaluate the effects of different dietary levels of crude protein (CP) and lysine (LYS) on performance, internal egg quality and to determine the nitrogen balance and its apparent metabolizability coefficient (Experiment 1), and to evaluate the effects of different dietary levels of LYS and methionine (MET) on performance, internal egg quality and functional properties of egg components (Experiment 2). One hundred sixty hens were randomly distributed in a 4 x 2 factorial scheme: CP levels (12%, 14%, 16% and 18%) and LYS levels (0,85% and 1,00%) totalizing eight treatments with five replicates of four birds each (Experiment 1). Two hundred fifty six hens were randomly distributed in a 4 x 4 factorial scheme: LYS levels (0,482%, 0,682%, 0,882% and 1,082%) and MET levels (0,225%, 0,318%, 0,411% and 0,505%) totalizing sixteen treatments with four replicates of four birds each (Experiment 2). Several characteristics were evaluated such as performance: intakes of feed, LYS, MET, CP and energy, egg production, egg weight, egg mass, and feed conversion; internal egg quality: weight and percentages of egg albumen and egg yolk, Haugh unit; quality of storaged eggs: Haugh unit, egg weight and albumen height; analyses of concentrations of protein, total solids, viscosity and pH of the egg components. The characteristics intake of CP, egg weight, egg mass, and albumen percent showed positive and linear response. In both experiments, the quality of storaged eggs was better when eggs were storaged in refrigerated environment than natural environment. However, irrespective of the environment, the internal egg quality was impaired as the time of storage was increased. Maximum responses for analyses of protein, total solids, viscosity, and pH of albumen and yolk were obtained when hens were fed diets containing 15,33% of CP. In the Experiment 1, after the experimental period, another assay was carried out to determine the nitrogen balance by using total excreta procedure during a three-day period. It was observed increase of intake and excretion of nitrogen as the content of CP in the diet was increased. In the Experiment 2, feed intake, MET intake, energy intake, egg production, egg weight, and egg mass showed maximum responses when hens were fed diets containing 0,870% of LYS and 0,450% of MET. Egg grading, internal and external egg quality characteristics were not influenced by the different dietary levels of MET and LYS. The functional properties of egg components (cooking quality by making Angel and Sponge cakes) were not affected by the treatments. It was concluded that hens fed diets containing 15,33% of CP, 0,450% of MET, and 0,870% of LYS show optimum performance, internal and external egg quality.
20
Seta, Luciane de. "Estudo da atração miraxonal e da composição bioquimica da hemolinfa, da agua de condicionamento e da glandula do albumen de Biompharia glabrata e Biompharia tenagophila infectadas por Schistosoma mansoni." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314958.
Full textAbstract:
Orientador: Luiz Augusto MagalhãesTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-07-21T19:20:20Z (GMT). No. of bitstreams: 1 Seta_Lucianede_D.pdf: 7041259 bytes, checksum: 63818bb271fb5ebabc71fe09ec0a175a (MD5) Previous issue date: 1996
Resumo: Estudamos a atração miraxonal frente à moluscos Biomphalaria glabrata e Biomphalaria tenagophila infectados ou não pelo Schistosoma mansoni, sua água de condicionamento (SCW), sua hemolinfa e seu extrato da glândula do albúmen. Em síntese, pudemos observar que moluscos B. tenagophila infectados atraíram mais miracídios de S. mansoni S1 que os moluscos não infectados. O mesmo ocorreu com sua SCW, sua hemolinfa e também seu extrato da glândula do albúmen. O mesmo não ocorreu em B. glabrata infectada por S. mansoni, que apresentou uma nítida repelência aos miracídios BH. Em B. glabrata observamos que sua SCW atraiu mais miracídios de S. mansoni BH que o próprio molusco. Moluscos B. glabrata sadios atraíram mais miracídios que os moluscos infectados. Ao compararmos a atração miraxonal frente ao extrato da glândula do albúmen de moluscos sadios e infectados com sua SCW pudemos verificar que: 1) Os componentes do extrato da glândula do albúmen seriam quimioatraentes para os miracídios de S. mansoni; 2) O extrato da glândula do albúmen atraiu mais miracídios que sua SCW, independente dessa SCW ser de moluscos sadios ou infectados por S. mansoni. Paralelamente analisamos o conteúdo de aminoácidos livres da hemolinfa, da SCW e do extrato da glândula do albúmen de B. glabrata e B. tenagophila infectadas ou não pelo S. mansoni. Na hemolinfa de B. glabrata sadia (HBgS) foram encontrados 28 aminoácidos livres, e na hemolinfa de moluscos infectados (HBgI) foram encontrados 32. Na hemolinfa de B. tenagophila sadia (HBtS) foram encontrados 28 aminoácidos livres e na hemolinfa dos moluscos infectados foram encontrados 33. Na hemolinfa de B. glabrata infectada houve um aumento geral da concentração de aminoácidos livres em relação ao encontrado na hemolinfa de moluscos sadios. Na hemolinfa de B. tenagophila infectada houve uma redução da concentração de aminoácidos livres em relação aos moluscos sadios. Na água de condicionamento (SCW) de B. glabrata sadias foram encontrados 19 aminoácidos livres, enquanto que na SCW desses moluscos, infectados por S. mansoni foram encontrados 17. Na SCW de B. tenagophila sadias foram encontrados 19 aminoácidos livres, enquanto que na SCW de B. tenagophila infectados foram encontrados 16. Não houve correspondência entre o conteúdo de aminoácidos livres da hemolinfa e da SCW. No extrato da glândula do albúmen de B. glabrata sadios foram encontrados 4 aminoácidos livres e nos moluscos infectados foram encontrados 5. No extrato da glândula do albúmen de B. tenagophila sadia foram encontrados 7 aminoácidos livres e nos moluscos infectados foram encontrados 6. Analisamos o conteúdo de aminoácidos livres como possíveis quimioatraentes para os miracídios de S. mansoni. Através da eletroforese em gel de poliacrilamida da hemolinfa verificamos haver uma redução de algumas frações proteicas na hemolinfa de B. tenagophila infectadas por S. mansoni, por volta de 45 Kda. A cromatografia de exclusão molecular da hemolinfa apresentou em ambas espécies de moluscos sadios ou infectados uma característica nítida da presença da hemoglobina e as demais frações de menor peso molecular. Tal resultado foi confirmado na eletroforese (SDS-P AGE)
Abstract: We studied the miraxonal atraction in the snails Biomphalaria glabrata and B. tenagophila, both infected with Schistosoma mansoni and non infected , the snail conditioned water (SCW), the hemolymph and the albwnen gland extract. We were able to observe that infected B. tenagophila atracted more SJ S. mansoni miracidia than the non-infected snails. The same fact was observed with the SCW, the hemolymph and the albwnen gland extract. The opposite results occur with infected B. glabrata snails, wich showed a clear repellence to the BH S. mansoni miracidia. In B. glabrata snails, we observed that their SCW atracted more BH S. mansoni miracidia than snails. Non infected B. glabrata atracted more miracidia than the infected ones. The comparison of the miraxonal atraction to the albumen gland extracts of non infected and infected snails with their SCW, showed that: 1) The components of the albumen gland extract were chemoattactive to S. mansoni miracidia; 2) The albwnen gland extracts attracted more miracidia than their SCW, regardless of the SCW being from infected or non infected snails. In addition, we analysed the presence of free amino acids in the hemolymph, SCW and albumen gland extracts of infected by S. mansoni or non infected B. glabrata and B. tenagophila. In the hemolymph of non infected B. glabrata (HBgS), we found 28 free amino acids, and in the hemolymph of snails infected with S. mansoni (HBgI) we found 32. In the hemolymph of infected B. glabrata, there was a general increase in concentration of free arnino acids when compared to the values observed in the hemolymph of non infected snails. In the snail conditioned water (SCW) of non infected B. glabrata (WBgS) we found 19 free amino acids, while in the SCW of snails infected with S. mansoni, on1y 17 amino acids were found. In the SCW of non infected B. tenagophila 19 free amino acids were found, whereas in the the SCW of infected B. tenagophila 16 free amino acids were found. No relationship between the content of free amino acids of the hemolymph and SCW was detected. In the albumen gland extract of non infected B. glabrata 4 free amino acids were found and 5 in the infected snails. In the albumen gland extract of non infected B. tenagophila we found 7 free amino acids and 6 in the infected snails. Free amino acids were tested as possible chemoattratents to the S.mansoni miracidia. Through polyacrilamide gell electrophoresis (SDS-P AGE) we verified a reduction of some protein fractions with molecular weight in the range of 45 Kda, in the hemolympph of B. tenagophila infected with S. mansoni. The molecular exc1usion cromatography of the hemolymph of both species of snails showed a c1ear presence of haemoglobin and other fractions with lower molecular weights. This result was confirmed by the electrophoresis (SDS-P AGE)
Doutorado
Parasitologia
Doutor em Ciências
21
Belli, Carla Bargi. "Avaliação de solução concentrada de albumina eqüina na fluidoterapia em eqüinos com desidratação leve a moderada." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-13082007-114121/.
Full textAbstract:
A utilização de colóides é indicada em várias situações, mas nem sempre aplicável na clínica de eqüinos. O objetivo desse trabalho foi avaliar o uso de solução concentrada de albumina eqüina (diluída a 5%) durante fluidoterapia em eqüinos com desidratação leve a moderada, comparando-a com fluidoterapia apenas com solução fisiológica. Foram utilizados dois grupos de cinco eqüinos adultos, sem alterações clínicas. Cada animal passou pelo protocolo dos dois grupos experimentais (fluidoterapia apenas com solução fisiológica; fluidoterapia com solução de albumina eqüina e solução fisiológica). A desidratação foi induzida com duas aplicações de furosemida e jejum. Durante o experimento foram realizadas várias avaliações: pesagem; exame físico geral; hematócrito; osmolalidade plasmática; gasometria; proteína total; albumina; Na; K; débito cardíaco; pressão arterial; uréia e creatinina, e cálculo da pressão oncótica e volume plasmático. Com a aplicação da solução de albumina houve diferença em relação ao outro grupo, embora nem sempre demonstrada estatisticamente, na avaliação do turgor de pele, hematócrito, proteína total, albumina, Na plasmático, pressão arterial, débito cardíaco, pressão oncótica e volume plasmático. Concluiu-se que: a aplicação apenas de pequeno volume de solução de albumina é capaz de causar efeitos comparáveis aos da infusão sob pressão de metade do volume de solução fisiológica calculado para reidratar o mesmo animal; ao final da fluidoterapia, a solução de albumina leva a maior valor de pressão arterial e de albumina sérica e menor de proteína total, mesmo sem diferença estatística, do que apenas a aplicação de solução fisiológica; ao final da fluidoterapia, com o uso de solução de albumina o turgor de pele dos animais ainda indica presença de desidratação, ao contrário dos que recebem apenas solução fisiológica onde o mesmo indica boa hidratação em todos os animais; a solução concentrada de albumina eqüina é passível de ser usada em fluidoterapia nesta espécie, com facilidade de preparação e aplicação e não demonstrando efeitos deletérios.The colloids utilization is indicated in several situations, but not always applicable in equine practice. The objective of this study was to evaluate the use of the equine concentrated albumin solution (diluted to 5%) during fluid therapy in horses with slight to moderate dehydration, making a comparison with fluid therapy only with physiologic saline solution. Two groups of five adult horses, without clinical alterations, were used. Each animal was submitted to the protocol of each experimental group (fluid therapy only with physiologic saline solution; fluid therapy with equine albumin solution and physiologic saline solution). The dehydration was induced with two administrations of furosemide and fasting. During the experimental period, several evaluations were made: weighing; gasometry; total protein; albumin; Na; K; cardiac output; arterial pressure; urea and creatinin, and calculation of the oncotic pressure and plasmatic volume. With the administration of albumin solution, there was difference, although not always statistically demonstrated in the evaluation of the skin turgor, packed cell volume, total protein and albumin, plasmatic Na, arterial pressure, cardiac output, oncotic pressure and plasmatic volume. It was concluded that: the administration of only a small volume of albumin solution is capable of causing effects comparable to the infusion under pressure of half of the calculated volume of physiologic saline solution necessary to rehydrated the animal; at the end of the fluid therapy, the albumin solution leads to higher values of arterial pressure and serum albumin and lower values of total protein, although without statistical difference, than the single administration of physiologic saline solution; at the end of the fluid therapy, with the use of the albumin solution, the skin turgor still indicates the presence of dehydration, the opposite that occurs with the animals when receiving only physiologic saline solution, where the test indicates good hydration in all the horses; the equine concentrated albumin solution is utilizable in fluid therapy in this species, with easy preparation and administration and with no demonstration of deleterial effects.
22
Barthole, Guillaume. "Contribution à l’étude du contrôle transcriptionnel de la maturation de la graine d’Arabidopsis." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112166/document.
Full textAbstract:
Chez la plante modèle Arabidopsis, le processus de maturation de la graine et, en particulier, l’accumulation de composés de réserves (huile et protéines de réserve) sont étudiés depuis de nombreuses années. Si les voies de biosynthèse conduisant à l’accumulation de tels composés sont bien décrites, leur régulation est encore largement méconnue. Mon travail de thèse s’inscrit dans un projet de recherche dont le but est d’identifier de nouveaux régulateurs transcriptionnels de la maturation de la graine d’Arabidopsis. Après avoir réalisé une étude comparative du processus de maturation chez les deux zygotes de la graine, embryon et albumen, nous avons caractérisé un facteur de transcription appelé MYB118, exprimé spécifiquement dans l’albumen et potentiellement impliqué dans la régulation du processus de maturation. Son patron d’expression, finement caractérisé, montre un pic d’accumulation d’ARNm en début de maturation de la graine, plus spécifiquement dans l’albumen. Des études menées sur des lignées mutantes ou surexprimant LEAFY COTYELDON2 (LEC2) révèlent que l’expression de MYB118 est activée par ce régulateur maître de la maturation de la graine. Une analyse biochimique de graines myb118 montre que le contenu en huile et en protéines de réserve est doublé dans l’albumen et réduit dans l’embryon de ce mutant par comparaison aux graines sauvages. Finalement, une analyse transcriptomique effectuée sur des graines myb118 a permis d’identifier des cibles putatives dont la dérégulation pourrait expliquer le phénotype : MYB118 semble être un répresseur de l’accumulation de composés de réserve dans l’albumen. Comme la famille de facteurs de transcription à laquelle appartient MYB118 comprend de nombreux membres, nous nous sommes intéressés au patron d’expression et au rôle de ses paralogues les plus proches. L’un d’entre eux, appelé MYB115, est exprimé spécifiquement dans l’albumen chalazal et semble avoir une fonction partiellement redondante à celle de MYB118In the model plant Arabidopsis thaliana, seed maturation and more especially the accumulation of storage compounds such as oil and seed storage proteins (SSP) have been widely studied. Although the biosynthetic networks underlying the accumulation of such compounds are now well described, regulation of these pathways remains poorly understood. My Ph.D. project is a part of a research program aimed at identifying new transcriptional regulators of seed maturation in Arabidopsis. After a comparative analysis of maturation processes in the two zygotic tissues of the seed, namely the embryo and the endosperm, we have characterized MYB118, an endosperm-specific transcription factor, putatively involved in the regulation of this maturation process. A fine and comprehensive characterization of its expression pattern showed a peak of expression at the onset of the maturation phase in the endosperm. Expression studies carried out in LEAFY COTYLEDON2 (LEC2) mutant and over-expressing lines demonstrated that MYB118 expression is positively regulated by this master regulator. Biochemical analysis of myb118 seeds showed that oil and SSP contents were doubled in the endosperm fraction and decreased in the embryo of this mutant compared to the wild type. A transcriptomic analysis of myb118 mutant seeds point out some putative targets, the misregulation of which could explain this phenotype: MYB118 seems to be a repressor of storage compounds accumulation in the endosperm.Since MYB118 belongs to the broad family of MYB transcription factors, we investigated the expression pattern and the role of its closest paralogs. One of them, called MYB115 is expressed specifically in the chalazal endosperm and seems to have partially redundant functions with MYB118
23
Grimault, Aurélie. "Étude fonctionnelle de deux facteurs de transcription intervenant dans la régulation du développement du grain de maïs : ZmZOU impliqué dans la communication embryon-albumen et ZmAFL4 impliqué dans l'accumulation de réserves." Thesis, Lyon, École normale supérieure, 2014. http://www.theses.fr/2014ENSL0957.
Full textAbstract:
Le grain de maïs est composé de 3 compartiments : l’embryon et l’albumen issus de la double fécondation et l’enveloppe d’origine maternelle. Le développement du grain et l’accumulation de réserves demande l’établissement d’une communication étroite entre l’embryon et l’albumen pour coordonner leur développement respectif. Si, des régulateurs majeurs impliqués dans le développement de la graine d’Arabidopsis ont été décrits, ces connaissances restent parcellaires chez les céréales. Les objectifs de ma thèse consistaient d’une part à étudier le contrôle de la communication entre l’embryon et l’albumen et d’autre part la régulation du remplissage du grain de maïs. Par l’analyse de lignées transgéniques sous exprimant ZmZHOUPI (ZmZOU-RNAi), nous avons établi que ce facteur de transcription à domaine bHLH, bien que s’exprimant exclusivement dans l’albumen, affecte significativement le développement de l’embryon (taille de l’embryon, persistance du suspenseur). L’analyse de données RNAseq (grains sauvages versus grains ZmZOU-RNAi) a permis d’identifier des gènes cibles potentiels de ZmZOU. De plus, nous avons montré que 3 facteurs de transcription de type bHLH homologues d’INDUCER OF CBP EXPRESSION (ICE) forment un partenariat avec ZmZOU.D’autre part, nous avons étudié les homologues d'ABA INSENSITIVE3, FUSCA3 et LEAFY COTYLEDON2 (AFL) qui forment un réseau de facteurs de transcription, à domaine B3, régulant l’accumulation d’huile et de protéines de réserves dans l’embryon d’Arabidopsis. Grâce à des analyses phylogénétiques et d’expression, nous avons établi que chez le maïs le réseau AFL, constitué de 5 membres (ZmAFLs), est partiellement conservé. Par dosages et analyse d’expression, nous avons montré que ZmAFL4, en particulier, est impliqué dans le contrôle de la biosynthèse de l’amidon dans l’albumenMaize kernel is composed of three major compartments: an embryo and an endosperm both produced by double fertilization and the maternally derived seed coat. Seed development and reserves accumulation demands coordination and thus communication between embryo and endosperm allowing specific growth of each compartment. While major regulators involved in seed development have been already described in Arabidopsis, knowledge in cereals remains limited. My thesis purposes were to study on one hand the control of communication between embryo and endosperm and on the other hand regulation of maize kernel filling.By analysis of transgenic lines knock down ZmZHOUPI (ZmZou-RNAi), we showed that this bHLH domain transcription factor, exclusively expressed in endosperm, affect significantly embryo development, size of embryo proper and suspensor persistence. RNAseq data analyses let find putative direct targets of ZmZOU. Additionally, we identified ZmZOU partners, 3 bHLH domain transcription factor homologs of INDUCER OF CBP EXPRESSION (ICE).Furthermore, we studied homologs of three B3 domain transcription factors named ABA INSENSITIVE3, FUSCA3 et LEAFY COTYLEDON2 (AFL) which form a regulatory network governing oil and seed storage proteins accumulation in Arabidopsis embryo. By phylogenetic and expression analysis, we established that 5 genes (ZmAFLs) constitute in maize a partially conserved AFL network. Through dosage and expression analysis, we established that particularly ZmAFL4 is involved in starch biosynthesis regulation
24
Aquino, Adriano. "Análise proteômica dos ovos de codorna não fertilizados em diferentes tempos e temperaturas de estocagem." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75133/tde-18082015-100420/.
Full textAbstract:
O uso de codornas japonesas (Coturnix coturnix japonica) como modelo animal para estudos relacionados a indústria avícola está crescente em decorrência do aumento no consumo de carne e ovos. O ovo possui várias aplicações e a sua funcionalidade está correlacionada com a composição química e, mais especificamente, com seu alto valor proteico. Contudo, o ovo é um alimento altamente perecível, pois pode perder sua qualidade rapidamente entre o período de estocagem e consumo. A qualidade do ovo pode ser afetada por condições ambientais como tempo e temperatura de estocagem. Parâmetros convencionais como pH, massa e a unidade Haugh são usados para a avaliação da qualidade do ovo. Além disso, técnicas analíticas podem ser utilizadas para a avaliação de qualidade em diversas matrizes alimentares. Assim, o presente trabalho tem como objetivos a avaliação e identificação de proteínas presentes em ovos de codorna japonesa submetidos a diferentes tempos e temperaturas de estocagem empregando técnicas eletroforéticas e espectrometria de massas, além de, ferramentas estatísticas. Durante estocagem à 0-21 dias, observou um aumento no pH, diminuição na massa do ovo e uma mudança significativa no proteoma das amostras nos períodos de 14 a 21 dias. Além disso, os resultados de análise de componentes principais (PCA) demostraram a influência da temperatura pela formação de 4 grupos independentes para amostras de albúmen e 3 grupos para as amostras de plasma e fração granular, respectivamente. Para o plasma, as amostras estocadas à 25 °C e controle se agruparam. Já para a fração granular, o agrupamento ocorreu entre as amostras estocadas a 25 °C com a 37 °C, demonstrando similaridade entre si. As proteínas com os níveis significativamente (p <0.05) alterados durante a estocagem pertencem as famílias serpina (ovalbumina), transferrina (ovotransferrina), inibidores Kazal tipo de protease (ovoinibidor). Para a ovotransferrina, proteína encontrada em todas as amostras foi observado a formação de isoformas no albúmen, plasma e fração granular nas amostras estocadas a 37 °C, sendo um bom indicador de controle de qualidade. Por fim, para as amostras de albúmen fracionadas por OFFGEL e analisadas por 1D-PAGE foi observado a formação de isoformas tanto para a ovalbumina quanto para a ovotransferrina bem como a degradação de ovoinibidor nas amostras estocadas por 21 dias a 37 °C, fatos que podem estar associados ao desbaste. Esses eventos afirmam a influência do tempo e temperatura de estocagem na qualidade do ovo de codorna.The use of Japanese quail (Coturnix coturnix japonica) as animal model for studies related to the poultry industry is becoming more common due to the increased consumption of meat and eggs. The egg has a variety of applications and its functionality is correlated to the chemical composition and, more specifically, its high protein value. However, the egg is a highly perishable food, and it can lose its quality between the period of storage and consumption. The egg quality can be affected by environmental conditions such as storage time and temperature. Conventional parameters such as pH and Haugh unit mass are used for egg quality assessment. Furthermore, analytical techniques can be used for quality assessment in various food matrices. This study aims to review and to identify proteins present in Japanese quail eggs submitted at different times and storage temperatures using electrophoretic techniques and mass spectrometry techniques, as well as statistical tools. During storage at 0-21 days, observed an increase in pH, decrease in egg mass and a significant change in the proteome of samples during the 14 to 21 day period. Moreover, the principal component analysis results (PCA) have shown the influence of temperature because of the formation of the four groups to albumin samples and three groups for the plasma and granules fraction samples, respectively. In plasma, the samples stored at 25 ° C and clustered control. As for the granule fraction pooling occurred between samples stored at 25 ° C to 37 ° C, showing similarities among them. The proteins with significant levels (p <0.05) of change during the storage belong to serpin family (albumin), transferrin (ovotransferrin), Kazal type protease inhibitors (ovoinhibitor). Ovotransferrin, a protein isoform found in albumin, plasma and granules fraction samples and was observed the formation of more isoforms in samples stored at 37 ° C, a good to quality control lost indicator. Finally, for the albumen samples that were fractionated by OFFGEL and analyzed by 1D-PAGE, the formation of both isoforms to ovalbumin was observed as well as ovotransferrin and ovoinhibitor degradation in samples stored for 21 days at 37 ° C that can be associated to thinning. These events affirm the influence of time and storage temperature on quail egg quality.
25
Fragoso, Viviane Muniz da Silva. "Estudo da interação de antipsicóticos atípicos e albumina sérica com base em modelos matemáticos e espectrofluorimétricos." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=5913.
Full textAbstract:
Os antipsicóticos são drogas utilizadas no tratamento de muitos transtornos psiquiátricos, sendo classificados em dois grupos: típicos e atípicos. Os típicos formam o grupo de drogas que bloqueiam especialmente os receptores de dopamina e, por isto, causam efeitos colaterais característicos, que se manifestam através de sintomas extrapiramidais e podem terminar em discinesia tardia. Os atípicos apresentam eficácia antipsicótica similar à dos antipsicóticos típicos, mas produzem menos efeitos colaterais extrapiramidais e não causam discinesia tardia. Os antipsicóticos se ligam às proteínas plasmáticas, principalmente a albumina, a qual representa cerca de 60% do total das proteínas no soro humano. Neste trabalho estudamos os processos de interação de duas drogas antipsicóticas atípicas, risperidona e sulpirida, com as albuminas séricas humana (HSA) e bovina (BSA), através da técnica de supressão da fluorescência intrínseca do triptofano. A partir dos espectros de fluorescência, a análise dos dados foi feita obtendo-se os gráficos e as constantes de Stern-Volmer. A análise da supressão da fluorescência foi feita a partir da média aritmética dos dados oriundos dos experimentos realizados em cada condição adotada. Como a molécula da sulpirida é fluorescente desenvolvemos uma modelagem matemática do processo de interação, que nos permitiu então obter os dados referentes à supressão da fluorescência da proteína. Os resultados mostraram que a risperidona e a sulpirida suprimem a fluorescência de ambas albuminas por um processo de quenching estático, formando complexos droga-albumina. A risperidona tem uma afinidade com a HSA cerca de 6,5 vezes maior do que a sulpirida, a 37 oC. As constantes de associação calculadas para a interação risperidona-HSA, através da Teoria de Stern-Volmer, foram 1,43 ( 0,05) x 105 M-1, a 37 C, e 2,56 ( 0,09) x 105 M-1, a 25 C1; e para a sulpirida, 2,20 ( 0,08) x 104 M-1, a 37 C, e 5,46 ( 0,20) x 104 M-1, a 25 C. Como a taxa de quenching da BSA foi maior do que a da HSA, sugerimos que o sítio primário para a risperidona nas albuminas esteja localizado mais próximo ao domínio do triptofano 134 da BSA do que do domínio do triptofano 212 da HSA. O mesmo sugerimos com relação ao sítio para a sulpirida a 37 C.Antipsychotics are drugs used to treat many psychiatric disorders. They are classified into two groups: typical and atypical. The typical group act blocking dopamine receptors in particular and it causes characteristic side effects with extrapyramidal symptoms, and can lead to tardive dyskinesia. The atypical group presents similar efficacy to typical group, but they produce less extrapyramidal side effects and does not cause tardive dyskinesia. Antipsychotics bind to plasmatic proteins, mainly to albumin, which represents about 60% of total human serum proteins. In this study we studied the interactions of two atypical antipsychotic drugs, risperidone and sulpiride, with human serum albumin (HSA) and bovine (BSA) through the technique of intrinsic tryptophan fluorescence quenching. From the fluorescence spectra, a data analysis was made to obtain Stern-Volmer plots and constants. Quenching analysis was performed used from using arithmetic means of data from experiments for each adopted condition. As sulpiride molecule is fluorescent, a mathematical modeling for interaction process was made. It allows us then to obtain the data referents to fluorescence quenching of protein. Results showed that risperidone and sulpiride quench the fluorescence for both albumins by static quenching process, forming complexes drug-albumin. The risperidone affinity to HSA is about 6.5 higher than supiride, at 37 oC. Stern-Volmer constants for interaction risperidone-HSA were 1.43 ( 0.05) x 105 M-1, at 37oC, and 2.56 ( 0.09) x 105 M-1, at 25 oC; and for sulpiride were 2.20 ( 0.08) x 104 M-1, at 37 oC, and 5.46 ( 0.20) x 104 M-1, at 25 oC. As the quenching ratio for BSA was higher than HAS, we suggested that the primary site for risperidone on albumin is closer of the domain of trypthophan 134 of BSA than the domain of trypthophan 212 of HAS. The same is suggested for the primary site of supiride at 37oC.
26
Martins, Caroline de Azevedo. "Lipotoxicidade na leptospirose humana: aspectos prognósticos e potencial efeito benéfico da administração de albumina." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3309.
Full textAbstract:
A leptospirose humana é uma doença infecciosa aguda de amplo espectro clínico e que cursa com alterações metabólicas e dislipidêmicas envolvendo colesterol total e frações, triglicerídeos e ácidos graxos não esterificados (AGNEs). Dentre os mecanismos celulares envolvidos na sua fisiopatologia encontram-se a inibição da enzima Na, K ATPase pela endotoxina GLP e a lipotoxicidade, ambos agravados pela redução dos níveis circulantes da albumina, molécula que exerce um papel fundamental na adsorção de moléculas lipídicas. Neste estudo observacional, determinamos as concentrações séricas de bilirrubina, creatinina e albumina e, pela técnica de cromatografia líquida de alta performance, a concentração sérica dos AGNEs de cadeia longa (C16: C18) de 27 pacientes com síndrome de Weil durante o período de internação hospitalar, dos quais cinco vieram a falecer. Verificamos correlações significantes (p<0,05) ao longo da internação hospitalar, nas concentrações séricas de marcadores bioquímicos de gravidade da doença (bilirrubina, creatinina e albumina), AGNEs, ácido oléico e ácido linoléico, e relação molar ácido oléico/ albumina, com r (Pearson) de -0,7981, -0,7699, 0,9014, -0,8795 -0,9816, -0,9694, -0,9821, respectivamente. A relação molar ácido oléico/ albumina e ácido oléico+ linoléico/albumina foi significantemente mais elevada nos pacientes que faleceram (p<0,001), retornando aos valores semelhantes aos do grupo controle nos pacientes que evoluíram para a cura. Na análise por Curva Roc, a relação molar ácido oléico/albumina se mostrou um bom teste preditivo, com valor de corte 0,705 associado com maior especificidade e sensibilidade prognóstica. Nossos resultados sugerem que a utilização parenteral da albumina humana em pacientes com leptospirose pode ser uma potente ferramenta terapêutica nos casos mais graves ao interferir positivamente no resgate do equilíbrio bioquímico das relações molares ácido oléico/ albumina e ácido oléico+linoléico/albumina.
27
Moussu, Steven. "A functional and genetic analysis of novel signaling molecules regulating embryo surface formation in Arabidopsis thaliana." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEN067/document.
Full textAbstract:
Le développement de la graine est une étape cruciale du cycle de vie des Angiospermes. La graine est composée de trois compartiments : (1) Le tégument, assurant un rôle protecteur, (2) l’albumen, qui a un rôle principalement nourricier pour (3) l’embryon, qui donnera la future plante. Ainsi, ces trois tissus se développent de concert pour former une graine viable. Une telle coordination présuppose que les différents compartiments communiquent entre eux. Dans ce contexte, j’ai étudié les gènes impliqués dans la formation de la cuticule embryonnaire, une structure hydrophobe recouvrant la plante et essentielle pour limiter les pertes d’eau, assurant ainsi sa survie. Au début de ma thèse, différents gènes étaient déjà connus, certains spécifiques de l’embryon, et d’autres spécifiques de l’albumen, renforçant l’idée de l’existence d’une communication moléculaire entre les deux tissus. Côté albumen, le facteur de transcription ZOU contrôle l’expression d’ALE1, une protéase. Côté embryon, deux récepteurs, GSO1 et GSO2, sont impliqués. L’étude de l’interaction génétique de ces différents gènes a permis de prouver leur appartenance à la même voie de signalisation. L’identité de ces gènes nous a amené à supposer l’existence d’un ou plusieurs peptides agissant comme messagers entre l’embryon et l’albumen. Ainsi, mes travaux de thèse ont permis de caractériser de nouveaux gènes impliqués dans ce processus, ainsi que certaines propriétés de la cuticule. Le principal est CERBERUS, dont l’expression est contrôlée par ZOU, un peptide sécrété par l’albumen qui est nécessaire pour la mise en place d’une cuticule fonctionnelle et la mise en place d’une structure non encore décrite à ce jour, la gaine embryonnaire. Un nouveau rôle pour GSO1 et GSO2 a aussi été démontré. Des résultats préliminaires suggèrent que TPST, une enzyme impliquées dans la sulfation des peptides, est impliquée dans la voie de signalisation étudiée. Enfin, mes travaux ont identifiés un autre gène, FRIABLE1, qui est aussi essentiel à la mise en place de la cuticule et joue dans la même voie de signalisation. Les découvertes associées à mes travaux de thèse ont permis de compléter et d’approfondir les connaissances sur les gènes impliqués dans la formation de la surface de l’embryon chez ArabidopsisSeed development is a crucial step in Angiosperms life cycle. The seed is composed of three distinct compartments: (1) The testa, ensuring a protective function, (2) the endosperm, which plays a key nutritive role supporting (3) the embryo, the fate of which is to become the future plant. These three tissues develop concomitantly to form a viable seed. Such developmental coordination necessitates the involvement of communication between the compartments. In this context, I have studied genes involved in the establishment of the embryonic cuticle, a hydrophobic structure that surrounds the embryo, plays an essential post-germination function in regulating water loss and is thus critical for plant survival. At the beginning of my PhD, several proteins were known to be involved in the process of cuticle establishment, some of which were expressed in the endosperm and others in the embryo, hinting at the existence of molecular communication between the two tissues. On the endosperm side, the transcription factor ZOU controls the expression of ALE1, a subtilisin-like serine protease. On the embryo side, two receptors, GSO1 and GSO2, are involved. Genetic interaction between the genes encoding these proteins had confirmed their involvement the same signalling pathway. The molecular identities of these proteins led us to propose the existence of one or more unidentified peptides acting as messengers between the embryo and the endosperm. My research has allowed the characterization of novel proteins involved in the process of embryonic surface formation. The principal subject of my research has been CERBERUS, a peptide produced in the endosperm, the expression of which is controlled by ZOU, and which is necessary both for the formation of an intact embryonic cuticle and the production of a previously uncharacterised structure, the embryo sheath. I have demonstrated novel roles for GSO1 and GSO2 in embryo sheath deposition. Furthermore, I have generated preliminary data suggesting that a protein involved in peptide sulfation, TPST, is involved in the GSO1 GSO2 signalling pathway. Finally, I have shown that another protein involved in posttranslational protein modification, FRIABLE1 is involved in this same pathway. My results have advanced knowledge of the molecular mechanisms controlling embryonic surface formation in Arabidopsis
28
Topin, Vincent. "Matériaux granulaires cimentés : modélisation et application à l'albumen de blé." Phd thesis, Montpellier 2, 2008. http://www.theses.fr/2008MON20102.
Full textAbstract:
Ce travail de thèse est consacré à l'étude des matériaux granulaires cimentés composés d'un assemblage dense de particules et d'une matrice remplissant partiellement l'espace entre les particules. Cette étude a été plus particulièrement appliquée au cas de l'albumen de blé, modélisé comme un assemblage de granules d'amidon liés entre eux par une matrice protéique, afin de comprendre les origines physiques de la friabilité (blés hard, soft, durum) des variétés de blé. Une modélisation numérique basée sur une discrétisation sur réseau a permis de prendre en compte la déformation et la rupture des phases et de leurs interfaces. Nous avons mis en évidence, par une étude paramétrique en compression et en traction simples, trois régimes de rupture caractérisés par l'endommagement des particules en fonction de la fraction volumique de la matrice et de l'adhésion à l'interface entre les particules et la matrice. La microstructure granulaire contrôle la concentration des contraintes, mise en évidence par leurs densités de probabilité, et le mode de fissuration du milieu. Une comparaison a été réalisée avec la méthode des éléments discrets dans le cas de la transmission des forces. Des expériences de compression simple sur un matériau modèle ont permis de valider les résultats numériques en faisant varier la fraction volumique de la matrice et l'adhésion particule-matrice. Dans les deux cas, numérique et expérimental, on a montré que l'endommagement des particules est gouverné par une ténacité relative à l'interface particule-matrice qui combine la fraction volumique de la matrice et l'adhésion à l'interface. Nous avons également élaboré un modèle théorique simple permettant de prendre en compte les effets de structure granulaires pour prédire les seuils de rupture et les modules élastiques en traction et en compression. Le rapprochement entre nos résultats et les données relatives à l'endommagement des granules d'amidon pour différentes variétés de blé suggère que l'adhésion à l'interface entre la matrice protéique et les granules d'amidon est contrôlée par le volume de puroindolinesIn this work, we investigate cemented granular materials involving a dense particulate structure and a continuous matrix filling partially the interstitial space. The results were applied to the wheat endosperm modelled as an assembly of starch granules embedded in a protein matrix in view of better understanding of the origins of the wheat hardness (soft, hard and durum classes of wheat). The deformation and fracture of the particle and matrix phases and their interface were modelled by means of a lattice element approach. Three regimes of crack propagation were evidenced by a detailed parametric study in simple compression and tension. These regimes are characterized by particle damage as a function of the matrix volume fraction and particle-matrix adhesion. The granular microsctructure is shown to control the stress concentration, analyzed through the probability densities of the local stresses, and the rupture modes. The force transmission is found to compare well between the lattice element method and discrete element method. Simple compression tests were performed on samples of a cemented granular material in which the matrix volume fraction (cement) and particle-matrix adhesion (LECA beads coated by silicone) were varied. The experimental results were in good agreement with numerical results. In both cases, we find that particle damage is controlled by the relative toughness of the particle-matrix interface combining the matrix volume fraction and particle-matrix adhesion. A simple theoretical model was elaborated taking into account the structural effects for the prediction of the elastic moduli in tension and compression, as well as the rupture thresholds. When compared to measured data concerning starch damage for different wheat varieties, our results suggest that the starch-protein adherence is dependent on the volume of puroindolines at the interface
29
Topin, Vincent. "Matériaux granulaires cimentés : modélisation et application à l'albumen de blé." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2008. http://tel.archives-ouvertes.fr/tel-00371864.
Full textAbstract:
Ce travail de thèse est consacré à l'étude des matériaux granulaires cimentés composés d'un assemblage dense de particules et d'une matrice remplissant partiellement l'espace entre les particules. Cette étude a été plus particulièrement appliquée au cas de l'albumen de blé, modélisé comme un assemblage de granules d'amidon liés entre eux par une matrice protéique, afin de comprendre les origines physiques de la friabilité (blés hard, soft, durum) des types de blé. Une modélisation numérique basée sur une discrétisation sur réseau a permis de prendre en compte la déformation et la rupture des phases et de leurs interfaces. Nous avons mis en évidence, par une étude paramétrique en compression et en traction simples, trois régimes de rupture caractérisés par l'endommagement des particules en fonc- tion de la fraction volumique de la matrice et de l'adhésion à l'interface entre les particules et la matrice. La microstructure granulaire contrôle la concentration des contraintes, mise en évidence par leurs densités de probabilité, et le mode de fissuration du milieu. Une comparaison a été réalisée avec la méthode des éléments discrets dans le cas de la transmission des forces. Des expériences de compression simple sur un matériau modèle ont permis de valider les résultats numériques. Dans les deux cas, numérique et expérimental, l'endommagement des particules est gouverné par une ténacité relative à l'interface particule-matrice qui combine la fraction volumique de la matrice et l'adhésion à l'interface. Nous avons également élaboré un modèle théorique simple permettant de prendre en compte les effets de structure granulaire pour prédire les seuils de rupture et les modules élastiques en traction et en compression. Le rapprochement entre nos résultats et les données relatives à l'endommagement des granules d'amidon pour différentes variétés de blé suggère que l'adhésion à l'interface entre la matrice protéique et les gra- nules d'amidon est contrôlée par le volume de puroindolines.
30
Silva, Sandra Huber da. "AVALIAÇÃO DA LIGAÇÃO DA ALBUMINA HUMANA AO NÍQUEL E SUA POTENCIAL APLICAÇÃO NA DETECÇÃO DA ISQUEMIA CARDÍACA." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/5934.
Full textAbstract:
Acute coronary syndrome (ACS) is characterized by the occurrence of a set of signs and
symptoms that are related to myocardial ischemia. Unstable angina (UA) and acute
myocardial infarction with ST segment elevation (AMI-SST) and without ST segment
elevation (AMI-SSST) comprise this syndrome. It stands out among the diseases that affect
the cardiovascular system due to its high prevalence and its impact on mortality in the general
population. Its formation occurs due to rupture or erosion of atheromatous plaque, producing
progressive tissue ischemia. This ischemia may progress to necrosis of the cardiomyocytes
and changes could be detected by laboratory biomarkers. The gold standard biomarkers for
the diagnosis of myocardial necrosis are the cardiac troponins I (cTnI) or T (cTnT), which
have nearly absolute myocardial specificity and clinical sensitivity, reflecting microscopic
areas of myocardial necrosis. However, markers used for the detection of myocardial
ischemia during the pre-infarction are potentially the most interesting because they offer the
opportunity for early intervention to prevent progression of the infarction. Thus, a biomarker
to detect myocardial ischemia in the absence of necrosis would add substantially to the
current clinical tools. The main objectives of this study were: (a) to evaluate the binding of
albumin to nickel in patients with suspected ACS and develop a laboratory method based on
this property capable of detecting cardiac ischemia, (b) develop a test protocol on the binding
of albumin to nickel adapted to the automated Cobas Mira, (c) to investigate the diagnostic
features of this method in the diagnosis of ACS, and (d) compare the test results of albumin
binding to nickel with the albumin cobalt- binding to investigate whether the type of metal
used in the test interferes with the diagnostic features of the method. Patients with myocardial
ischemia showed a reduction in the capacity of binding albumin to nickel. A test, which was
adapted for the automated Cobas Mira, was developed to detect this change. The binding test
of albumin to nickel showed a potential role in excluding the diagnosis of AMI and was
effective in the diagnosis of ACS because of its significant negative and positive predictive
values, respectively. The test using nickel showed a slightly higher skill in the diagnosis of
ACS than the test using cobalt. Thus, we could conclude that the type of metal (nickel or
cobalt) influences the characteristics of the diagnostic test.A síndrome coronariana aguda (SCA) caracteriza-se pela ocorrência de um conjunto de sinais e sintomas que estão relacionados à isquemia miocárdica. A angina instável (AI) e o infarto agudo do miocárdio com elevação do segmento ST (IAM-SST) e sem elevação do segmento ST (IAM-SSST) compõem esta síndrome. Destaca-se dentre as doenças que acometem o sistema cardiovascular devido a sua alta prevalência e seu impacto sobre a mortalidade na população em geral. Sua formação ocorre devido à ruptura ou erosão da placa ateromatosa, produzindo isquemia progressiva tecidual, sendo que esta isquemia pode progredir para necrose dos cardiomiócitos, podendo as alterações serem detectadas por biomarcadores laboratoriais. Os biomarcadores padrão-ouro para o diagnóstico de necrose miocárdica são as troponinas cardíacas I (cTnI) ou T (cTnT), que tem quase absolutas especificidade miocárdica e sensibilidade clínica, refletindo zonas microscópicas de necrose miocárdica. No entanto, marcadores utilizados para detecção da isquemia miocárdica na fase pré-infarto são potencialmente os mais interessantes, pois oferecem a oportunidade de intervenção precoce para impedir a progressão do infarto. Desta forma, um biomarcador que realmente detecte isquemia miocárdica na ausência de necrose acrescentaria substancialmente às atuais ferramentas clínicas. Os objetivos principais deste estudo foram: (a) avaliar a ligação da albumina ao níquel em pacientes com suspeita de SCA e desenvolver um método laboratorial baseado nesta propriedade capaz de detectar a isquemia cardíaca; (b) desenvolver um protocolo do teste de ligação da albumina ao níquel adaptado ao sistema automatizado Cobas Mira; (c) investigar as características diagnósticas deste método no diagnóstico da SCA; (d) comparar os resultados obtidos no teste de ligação da albumina ao níquel com o teste de ligação da albumina ao cobalto a fim de investigar se o tipo de metal utilizado no ensaio interfere nas características diagnósticas do método. Os pacientes com isquemia do miocárdio apresentaram uma redução na capacidade de ligação da albumina ao níquel, sendo desenvolvido um teste capaz de detectar essa alteração, o qual foi adaptado para o sistema automatizado Cobas Mira. O teste de ligação da albumina ao níquel apresentou um potencial papel na exclusão diagnóstica do IAM e foi eficaz no diagnóstico da SCA em virtude de seus significativos valores preditivos negativo e positivo, respectivamente. O ensaio utilizando o níquel demonstrou uma habilidade discretamente superior no diagnóstico da SCA, do que o ensaio que utiliza o cobalto, o que permite concluir que o tipo de metal (níquel ou cobalto) influencia nas características diagnósticas do ensaio.
31
Lambot, Nathalie. "Mouvements transmembranaires et effet sécrétagogue de l'albumine au niveau du syncytiotrophopblaste humain." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210899.
Full textAbstract:
Le placenta assure les échanges materno-fœtaux et possède une fonction endocrine autonome. Les hormones placentaire lactogène (hPL) et chorionique gonadotrope (hCG) sont synthétisées par le syncytiotrophoblaste. A ce jour, les mécanismes impliqués dans le contrôle de la sécrétion de ces deux hormones ne sont pas connus. In vitro, l’influx d’ions Ca2+ entraîne une augmentation immédiate et soutenue de la libération d’hPL et d’hCG à partir d’explants de placentas à terme. En outre, l’élévation de la concentration extracellulaire en albumine, principale protéine maternelle circulante en contact direct avec le trophoblaste, stimule de manière immédiate et transitoire la libération d’hPL et d’hCG.L’objectif de nos travaux a été de vérifier la spécificité de l’activité sécrétagogue de l’albumine au niveau du placenta, de caractériser les messagers cellulaires potentiellement impliqués dans la libération d’hPL et d’hCG, et de définir l’interaction entre l’albumine et le trophoblaste, en utilisant des explants provenant de placentas humains à terme.
Nos travaux démontrent que la riposte sécrétoire à l’albumine (5%, m/v) est largement mimée par d’autres agents colloïdaux (dextran et polygéline). Cette stimulation colloïdale de la libération d’hPL et d’hCG impliquerait une mobilisation de Ca2+ à partir de réserves intracellulaires. L’intervention de 3 messagers cellulaires a été envisagée: les IPs/DAG, l’AMPc, et le GMPc. Le fluorure de sodium, la forskoline, ou le nitroprussiate sodique, activateurs connus de la production respective des IPs, de l’AMPc, et du GMPc, augmentent de manière significative les taux placentaires de chacun de ces messagers, sans toutefois affecter la libération d’hPL ou d’hCG. De plus, l’élévation de la concentration extracellulaire en albumine (5%, m/v) ne modifie pas les taux des IPs, de l’AMPc et du GMPc dans les explants placentaires, tandis qu’elle stimule la sécrétion hormonale. Ces systèmes de signalisation, bien que fonctionnels au niveau du trophoblaste, ne joueraient donc pas un rôle majeur dans la régulation de la libération d’hPL et d’hCG.
Nos résultats mettent en évidence une internalisation rapide d’albumine marquée, avec de l’125I ou de la fluorescéïne, dans le syncytiotrophoblaste. Une large fraction de cette albumine est recyclée, intacte, vers la circulation maternelle selon un processus sensible à l’abaissement de la température et indépendant du cytosquelette. L’albumine marquée restant dans les explants placentaires est partiellement dégradée. Trois mécanismes ont été envisagés pour expliquer ces mouvements d’entrée et de sortie de l’albumine au sein du placenta humain: l’endocytose médiée par l’albondine via les caveolae, le système des coated pits clathrine-dépendant, et l’endocytose médiée par la mégaline. Par immunohistochimie, nous avons montré que, dans le tissu placentaire, la caveoline-1, protéine caractéristique des caveolae, est localisée uniquement dans l’endothelium des capillaires fœtaux. La clathrine, au niveau des coated pits, et la mégaline se trouvent au contraire dans le syncytiotrophoblaste. La méthyl-b-cyclodextrine et l’hydrochlorure de chlorpromazine, inhibiteurs d’une endocytose dépendant de la clathrine, réduisent significativement l’internalisation placentaire de l’albumine marquée. Par contre, le DIDS ou le NPPB, susceptibles de perturber l’endocytose médiée par la mégaline, n’affectent pas la captation d’albumine marquée par les explants placentaires. L’albumine pénétrerait donc dans le syncytiotrophoblaste principalement par un processus clathrine-dépendant. La mégaline ne jouerait ici qu’un rôle mineur dans l’entrée de la protéine. Un tel processus de recyclage de l’albumine pourrait être similaire à celui décrit pour les immunoglobulines G au niveau du syncytiotrophoblaste.
Ces mouvement d’entrée et de sortie de l’albumine ne semblent pas associés à la stimulation de la libération d’hPL et d’hCG par l’albumine. Ils pourraient par contre participer significativement, étant donné leur ampleur, à la nutrition fœtale. L’albumine est en effet un transporteur notoire d’ions et d’acides gras, molécules qui pourraient être acheminées au fœtus via le phénomène de recyclage placentaire de l’albumine mis en évidence par ce travail. /
The human placenta is the site of all maternal-fetal exchanges, and is also an active endocrine organ. Placental lactogen (hPL) and chorionic gonadotrophin (hCG) hormones are synthesized by the syncytiotrophoblast. So far, the mechanisms involved in the regulation of both hormones secretion remain elusive. In vitro, calcium inflow causes an immediate and sustained rise in the hPL and hCG releases from human term placenta explants. Moreover, increasing the extracellular concentration of albumin, the major maternal plasma protein in direct contact with the human trophoblast, stimulates the hPL and hCG releases in an immediate and transient way.
Our study have aimed to check the specificity of this secretory effect of albumin, to investigate the potential cellular messengers involved in the hPL and hCG releases, and to define the interaction between albumin and the throphoblast layer, using human term placenta explants.
Our results indicate that the triggering effect of albumin (5%, w/v) is largely mimicked by two other colloidal agents (dextran and polygelin). This “colloidal” stimulation of the hPL and hCG releases would involve the mobilization of calcium from intracellular pools. Three cellular messengers have been considered to mediate this process: the IPs/DAG, the cAMP, and the cGMP. Sodium fluoride, forskolin, or sodium nitroprusside, known activators of respectively the IPs, cAMP, and cGMP production, significantly increase the placental content of each of those messengers, without modifying the hPL and hCG releases. In addition, raising the extracellular concentration of albumin does not cause any change in the placental level of IPs, cAMP, and cGMP, while stimulating the hormonal release. These three signaling pathways are thus functional in human term trophoblast but do not appear to significantly modulate the hPL and hCG secretions.
Our findings show that albumin, labeled with 125I or with fluorescein, is rapidly internalized into the syncytiotrophoblast. Thereafter, the intact protein is largely recycled to the maternal circulation, through a temperature-sensitive and cytoskeleton-independent process. The labeled albumin remaining in placental explants is partially degraded. Three different mechanisms could participate to the albumin entry into the human placenta: the albondin-mediated endocytosis via the caveolae, the clathrin-dependent coated pits system, and the megalin-mediated endocytosis. Using immunohistochemistry, caveolin-1, marker of the caveolae, is localized in the endothelium of the fetal capillaries and not in the syncytiotrophoblast. By contrast, clathrin and megalin are observed only in the syncytiotrophoblast. Methyl-b-cyclodextrin, and chlorpromazine hydrochloride, known inhibitors of the clathrin-dependent endocytotic process, significantly reduce the placental uptake of labeled albumin. On the other hand, DIDS or NPPB, able to perturb the megalin-mediated endocytosis, do not affect the labeled albumin uptake. Thus, albumin seems to be internalized into the syncytiotrophoblast mainly through a clathrin-dependent mechanism. Megalin would only play a minor role in this process. Such movements of albumin in the human placenta may be similar to the recycling process reported for IgG at that site.
The placental apical recycling of albumin is not associated to the albumin triggering effect on the hPL and hCG releases. This quantitatively significant internalization process may participate to the fetus’ nutrition. Indeed, Albumin carries ions and fatty acid, which could be brought to the fetus via the protein recycling evidenced by our study.
Doctorat en sciences biomédicales
info:eu-repo/semantics/nonPublished
32
Lesage, Véronique. "Contribution à la validation fonctionnelle du gène majeur contrôlant la dureté / tendreté de l'albumen du grain de blé par l'étude de lignées quasi-isogéniques." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00697012.
Full textAbstract:
La dureté du grain de blé est un des paramètres fondamentaux de la texture de l'albumen. Ce caractère, essentiel pour la valeur d'utilisation des farines, est fortement lié à l'absence ou à la modification des puroindolines. Afin de mieux comprendre la fonction biologique de ces protéines dans le grain de blé (Triticum aestivum L.), nous avons étudié à quatre stades de développement du grain la localisation subcellulaire des puroindolines par immunocytochimie et les protéomes dans deux lignées de blé quasi-isogéniques pour la dureté. Dès la fin de la cellularisation de l'albumen, les puroindolines sont localisées sur la face interne des membranes vésiculaires et dans les corps protéiques en formation, structures dans lesquelles s'accumulent les protéines de réserve du grain. L'analyse par AFFFF (Asymmetrical Flow Field-Flow Fractionation) des deux lignées Hard et Soft, qui diffèrent essentiellement par l'absence du gène Pina dans la lignée Hard, a montré une corrélation entre la dureté et la taille des polymères de protéines de réserve. L'analyse protéomique des fractions albumines/globulines et amphiphiles des grains en développement a révélé une augmentation des protéines de la machinerie de repliement et de réponse au stress dans la lignée Hard, par rapport à la lignée Soft. Les deux approches méthodologiques utilisées semblent également mettre en évidence une cinétique de développement du grain raccourcie dans la lignée Hard. Ces observations suggèrent que les puroindolines interagissent avec les protéines de réserve du grain et suivent le même routage cellulaire. Elles pourraient être impliquées dans les mécanismes de repliement et d'assemblage des prolamines.
33
Esposito, Breno Pannia. "Interações de Complexos de Ródio(II) com Albumina Humana." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/46/46134/tde-27092006-172252/.
Full textAbstract:
Vários complexos de ródio Rh2(L)4 (L = acetato, propionato, butirato, trifluoroaceta-to e trifluoroacetamidato) ligam-se à albumina de soro humana (HSA) em relações mola-res de aproximadamente 8:1. Medidas de dicroísmo circular mostraram que os carboxila-tos mais lipossolúveis (butirato e trifluoroacetato) provocaram as maiores alterações na estrutura secundária da HSA. As constantes de Stern-Volmer para a supressão de fluo-rescência da HSA por esses complexos também foram maiores para os compostos mais lipofílicos. O amidato lipossolúvel, Rh2(tfc)4, apresentou supressão intermediária e não provocou alterações estruturais. Isto mostra que é possível projetar metalofármacos anti-tumorais que se ligam a proteínas de transporte em grande quantidade, sem provocar al-terações estruturais importantes. Esses complexos tiveram também suas afinidades em relação à HSA determinadas por espectrofotometria, observando-se no caso dos alquil-carboxilatos uma correlação inversa com suas lipossolubilidades, o que sugere uma com-petição entre coordenação axial ao metal e interação hidrofóbica do ligante. A difusão dos complexos livres ou ligados à proteína para células de Ehrlich in vitro parece primordial-mente governada pelo caráter hidrofóbico do complexo. O complexo Rh2(tfc)4 apresentou afinidade pela proteína (K = 214,1), além de partição celular tanto em ausência (32,1%) como na presença (48,6%) de HSA. Desta forma, o composto HSA:Rh2(tfc)4 teve sua a-ção antitumoral investigada em camundongos Balb-c portadores de ascite de Ehrlich, mostrando que a HSA pode ser um reservatório para o complexo de ródio.Various divalent rhodium complexes Rh2(L)4 (L = acetate, propionate, butyrate, tri-fluoroacetate and trifluoroacetamidate) have been found to bind to non-defatted human serum albumin (HSA) at molar ratios about 8:1. The circular dichroism measurements showed that the more liposoluble carboxylates butyrate and trifluoroacetate caused the major alterations of the secondary structure of HSA. Stern-Volmer constants for the fluo-rescence quenching by these complexes were also higher for the lipophilic metal com-pounds. In the case of the rhodium carboxylates it was observed that their denaturating and quenching properties could be explained in terms of their liposolubilities: the higher their lipophilic characters, the higher their abilities to penetrate inside the protein frame-work leading to structural alterations, and the closer they could get to the Trp214 residue causing fluorescence quenching. The liposoluble amidate complex Rh2(tfc)4, presented an intermediate quenching and did not cause structural alterations in the protein, presumably not penetrating inside the peptidic backbone. This shows that it is possible to design new antitumor metal complexes which bind to a large extent to a transporter protein causing little structural damage. The affinities for human albumin of these five rhodium(II) comple-xes were determined by spectrophotometry. In the case of the alkylcarboxylates, an inver-se correlation of affinity with their liposolubilities was observed. Diffusion of the free or pro-tein-bound complexes into Ehrlich cells in vitro seems to be primarily governed by the hy-drophobic character of the complex. The complex Rh2(tfc)4 exhibited considerable affinity towards the protein (K = 214.1) as well as cell partition both in the absence (32.1%) and presence (48.6%) of HSA. The compound HSA:Rh2(tfc)4 has had its antitumoral action in tumor-bearing Balb-c mice investigated, showing that HSA can be a drug reservoir for the rhodium complex.
34
Donofre, Ana Carolina. "Vibrações no transporte de ovos fertilizados: efeitos no nascimento e na qualidade de pintos de corte." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-20032014-105707/.
Full textAbstract:
O objetivo deste trabalho foi avaliar os efeitos das vibrações mecânicas decorrentes do transporte sobre a qualidade de ovos fertilizados e sobre o nascimento e a qualidade de pintos de corte. O experimento foi dividido em duas fases desenvolvidas em um incubatório comercial em Mogi-Mirim/SP. Na primeira, 1920 ovos fertilizados de matrizes da linhagem Cobb-500 (31 a 34 semanas) foram expostos a simulações dos movimentos vibratórios, produzidos por um agitador mecânico desenvolvido para este fim. Na segunda fase, esses ovos foram incubados até o nascimento das aves. Avaliaram-se os efeitos de diferentes intensidades de vibração e tempos de exposição sobre as respostas de interesse. A intensidade foi definida por duas faixas de vibração simuladas pelo agitador (faixa inferior; RSS de 2,5 m.s-2 e faixa superior; RSS de 7,5 m.s-2), as quais foram associadas a dois tempos de exposição, um mínimo e um máximo (60 e 180 minutos, respectivamente). Foi adotado um delineamento aleatorizado em blocos com tratamentos em esquema fatorial mais um controle (2 x 2 + 1). A qualidade dos ovos fertilizados foi mensurada a partir da perda de peso e de medidas tomadas na gema e no albúmen (altura, diâmetro e índices, e unidade Haugh). Pela análise de variância foi possível observar efeitos dos fatores experimentais na qualidade dos ovos fertilizados, principalmente nas medidas tomadas no albúmen. Os resultados indicaram que os ovos quando expostos às vibrações, em faixas mais intensas e/ou por mais tempo, apresentam seu albúmen liquefeito, o que é um sinal de perda de qualidade. Esses resultados foram comprovados pela redução no índice de albúmen e na unidade Haugh, quando realizados os testes t e de Tukey a 5% de significância. Após o nascimento das aves foi avaliada a taxa de eclodibilidade, a caracterização da mortalidade e a qualidade dos pintos de corte (peso absoluto e classificação). Por meio da regressão logística, observou-se que a exposição dos ovos fertilizados às vibrações pode afetar negativamente a taxa de eclodibilidade e a proporção de pintos classificados em primeira linha. Essas respostas foram menores pelo teste de Wald a 5% de significância no tratamento formado pela faixa de vibração superior aplicada por mais tempo. Os piores resultados no nascimento refletiram diretamente em um aumento nas perdas totais devido à exposição dos ovos aos movimentos vibratórios, com a significância de efeito comprovada principalmente pela a faixa de vibração. Além disso, pela análise de variância foi observada uma pequena redução do peso das aves nascidas de ovos vibrados, quando feita a comparação de médias pelo teste t com o controle. Por fim, acredita-se que o comprometimento da qualidade do albúmen tenha gerado piores resultados no nascimento e na qualidade dos pintos de corte. Dessa forma, é possível concluir que a exposição às vibrações pode comprometer a incubação e gerar prejuízos de grandes dimensões para os incubatórios, caso ocorram em condições semelhantes às simuladas nesta pesquisa.The aim of this research was to evaluate the effects of mechanical vibrations during birth, and on the quality of fertile eggs and broiler chicks due to transportation. The experiment was divided in two phases developed in a commercial incubator in Mogi-Mirim, São Paulo. In the first phase, 1920 fertile eggs from Cobb-500 matrix (31 to 34 weeks) were used. These eggs were exposed to vibrations in a mechanical simulator. In the second phase, the eggs were incubated until the moment of birth. The effects of different vibration intensities and time exposition upon different feed backs were assessed. The intensity was defined by two vibration levels simulated by a mechanical agitator (inferior level; RSS - 2.5 m.s-2; superior level; RSS - 7.5 m.s-2), in which were associated to two different exposition periods of time (minimum, 60 minutes; and maximum, 180 minutes, respectively). A modeling in blocks with treatments in a factorial treatment and a control (2 x 2 +1) was chosen randomly. The quality of fertile eggs was evaluated considering the weight loss and measurements taken in the egg yolk and in the albumen (height, diameter, indexes, and Haugh unity). Using the analysis of variance, it was possible to observe the effects of experimental factors on the quality of fertile eggs, mainly, in the measurements found in the albumen. The results indicated that the eggs that were exposed to vibrations in very intense levels, and/or for more time, presented liquefied albumen, showing quality loss. These results were seen by the reduction in the albumen index as well as in the Haugh unity, found in the Tukey test submitted to the level of significance of 5%. After birth, the hatching tax, the mortality characterization, and the quality of broiler chicks (absolute weight and classification) were evaluated. Using the logistical regression, it was possible to observe that fertile eggs exposed to vibrations can affect negatively the hatching tax and the proportion of chicks classified in first line. These results were found smaller in the Wald test at significance of 5% in the treatment formed by the superior vibration level applied for a longer period of time. The worst results found in birth demonstrated an increase in total loss because of vibration exposition on the eggs with a significance effect proved, mainly, by the vibration level. Furthermore, through the analysis of variance, it was observed a small weight reduction of birds hatched from vibrated eggs. These results were observed when they were compared to the averages found in the control group and t test. Thus, if the albumen quality is compromised it is believed that it generates worst results in birth and in the quality of broiler chicks. Hence, it is possible to conclude that vibrations are capable of compromise incubation, resulting in huge financial loss for incubators, if similar conditions happen to be the way they were simulated on this study.
35
Runstrom, Gunilla. "Albumin in tears." Thesis, Aston University, 2013. http://publications.aston.ac.uk/19562/.
Full textAbstract:
Albumin is not endogenous to the tear film and is present as a product of plasma leakage. It is used as a diagnostic marker of ocular insult and inflammation. Tear albumin is, however, poorly understood, with large variations in reported concentrations between studies. There is also no authoritative information on whether its presence in tears is responsive or part of an adaptive reaction.The presented research aimed to resolve the disparities in published tear albumin concentrations and investigate the role of albumin in the tear film. Collation and evaluation of the available literature identified collection method, stimulus, assay technique, and disease state as factors able to influence quoted tear albumin to different extents. Difference in sampling technique exhibited the largest variations in mean tear albumin concentrations. Review of the literature also highlighted that little systematic investigations of the daily cycle of tear albumin levels, and subject-to-subject-variation, had been carried out. In order to remedy this shortcoming, variations in tear albumin concentration were investigated in 13 subjects throughout the waking day. Results identified a time period where albumin levels are relatively stable (2-6 hours post-waking). This was designated a suitable baseline for the determinations of tear albumin concentrations and subject-to-subject comparisons. Significantly, a previously unrecognised progressive increase in albumin concentration during the latter part of the day was also identified in the population. This increase suggests that albumin may play a more active and dynamic role in the ocular environment than is commonly perceived. To facilitate the collection of additional tear albumin data, tear sampling and point-of-care analysis in contact lens clinics were investigated. Two instruments were evaluated and were found to be suitable for the analysis of tear albumin in commercial institutions. Collectively, the described research has provided new insight into tear albumin and a strong foundation for further studies.
36
Figueira, Tiago Rezende 1980. "Alterações metabólicas e mitocondriais na analbuminemia congênita = estudos em ratos nagase analbuminêmicos-dislipidêmicos." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/308195.
Full textAbstract:
Orientador: Anibal Eugenio VercesiTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-19T05:29:39Z (GMT). No. of bitstreams: 1 Figueira_TiagoRezende_D.pdf: 22742066 bytes, checksum: dd66394fba07238337b8c5a2eeb0c858 (MD5) Previous issue date: 2011
Resumo: A analbuminemia congênita é uma doença autossômica recessiva caracterizada por níveis traços de albumina plasmática (< 1 mg/mL) e sintomas clínicos leves. Entre as comorbidades apresentadas pelos indivíduos e ratos analbuminêmicos (ratos Nagase - NAR), os distúrbios no metabolismo/transporte de lipídeos plasmáticos são as mais marcantes. A dislipidemia associada à analbuminemia é caracterizada por níveis aumentados de colesterol e triglicérides, e déficit de ácidos graxos livres (FFA). Nesta tese, são apresentados três estudos independentes sobre a analbuminemia, os quais objetivaram investigar: 1) os mecanismos da hipertrigliceridemia e do déficit de FFA plasmático do NAR; 2) o metabolismo de carboidratos no NAR; 3) as funções mitocondriais no NAR. Também é apresentado um quarto estudo (aspectos metodológicos) sobre o uso do probe safranina para avaliar o potencial elétrico transmembrana mitocondrial. Os principais resultados destes estudos foram: Estudo um: as taxas de lipogênese (596 ± 40 vs. 929 ± 124 ?mol 3H2O/g/h) e de secreção de triglicérides para o plasma (4,25 ± 1,00 vs. 7,04 ± 1,68 mg/dL/min) foram mais lentas (P ? 0,05) no NAR do que no rato controle Sprague-Dawley (SDR). As injeções de heparina ou de albumina no NAR promoveram um aumento de FFA plasmático em função do tempo. Noventa minutos após a injeção de albumina, os níveis de FFA plasmáticos nos NAR se elevaram de 0,36 ± 0,05 para 1,34 ± 0,16 mEq/L (P ? 0,05), atingindo os níveis do SDR. Estes resultados indicam que a falta de albumina plasmática inibe a lipólise intravascular e causa o déficit de FFA plasmático na analbuminemia, e que a produção hepática de triglicérides não contribui para a hipertrigliceridemia no NAR. Estudo dois: a concentração de glicose plasmática foi similar entre os NAR e os SDR alimentados ou em jejum, porém a insulinemia no estado alimentado foi maior nos NAR do que nos SDR (P ? 0,05). O NAR apresentou maior tolerância à glicose quando comparado ao SDR (P ? 0,05). Esta maior tolerância a glicose está associada à maior resposta insulinêmica à administração de glicose. Não houve diferença entre os grupos para a sensibilidade periférica a insulina. Apesar do conteúdo similar de glicogênio hepático no estado alimentado, o NAR apresentou menor conteúdo de glicogênio (40% do SDR) após 6 h de jejum. A injeção de piruvato (substrato neoglicogênico) promoveu um aumento mais rápido na glicemia do NAR em comparação ao SDR. Deste modo, os resultados indicam que o NAR apresenta metabolismo de glicose acelerado. Estudo três: a capacidade de retenção de Ca2+ pelas mitocôndrias isoladas do fígado do NAR aos três meses de idade foi ~50% daquela do SDR. Esta variável não se diferiu entre os grupos quando avaliada aos 21 dias de vida dos ratos. Foi observada uma depleção de ~20% no conteúdo de nitrosotiol e um aumento de ~30% na expressão de ciclofilina D nas mitocôndrias de fígado do NAR. Nenhuma das variáveis relacionadas ao estado redox mitocondrial diferiu entre NAR e SDR, tais como: o conteúdo de tióis reduzidos, de glutationa total, a taxa de liberação de H2O2, e o estado reduzido de NAD(P)H. Com isso, conclui-se que a maior expressão de ciclofilina D, um componente importante no processo de transição de permeabilidade mitocondrial, e o menor conteúdo de nitrosotiol nas mitocôndrias dos NAR podem explicar a sua menor capacidade de retenção de Ca2+
Abstract: Congenital analbuminemia is a rare autosomal recessive disorder characterized by a trace level of albumin in blood plasma and mild clinical symptoms. Analbuminemic patients and rats (Nagase analbuminemic rats - NAR) present associated abnormalities, among which the disturbances in plasma lipid metabolism and transport are hallmarks. The dyslipidemia associated with analbuminemia comprises a unique plasma lipid profile (i.e. high cholesterol and triglycerides, but a severe free-fatty acids deficiency). Three independent works on analbuminemia are presented in this PhD thesis, whose aims were: 1) to investigate the mechanisms of NAR hypertriglyceridemia and plasma free-fatty acids deficiency; 2) to study carbohydrate metabolism in NAR; 3) to evaluate mitochondrial (dys)function in NAR. Also, a methodological study about the use of the dye safranine as a fluorescent probe for the assessment of mitochondrial transmembrane electrical potential is presented in this thesis. The main results from these studies were: Study one: lipogenesis (596 ± 40 vs. 929 ± 124 ?mol 3H2O/g/h) and triglyceride secretion rates (4.25 ± 1.00 vs. 7.04 ± 1.68 mg/dL/min) were slower (P ? 0.05) in fasted NAR than in control Sprague-Dawley rats (SDR). The injection of either heparin or albumin elicited an increase in NAR plasma FFA levels over time. FFA levels reached control levels 90 min after the albumin administration into NAR, increasing from 0.36 ± 0.05 to 1.34 ± 0.16 mEq/L (P ? 0.05). These results indicate that the lack of plasma albumin inhibits intravascular lipolysis and causes the FFA deficit observed in NAR. Moreover, hepatic triglyceride output seems not to contribute to NAR hypertriglyceridemia. Study two: plasma glucose levels were similar between fed and fasted NAR and SDR, but fed insulinemia was higher in NAR than in SDR (P ? 0.05). NAR displayed increased glucose tolerance compared to SDR (P ? 0.05). This enhanced glucose tolerance was associated with higher insulinemia after the glucose load, and with similar insulin sensitivity between the groups. Despite similar liver glycogen content in fully fed condition, NAR had lower glycogen content (40% of control) after 6-h fasting. The injection of pyruvate (gluconeogenic substrate) elicited a faster rise in glycemia of NAR than in SDR. Therefore, NAR display enhanced glucose metabolism. Study three: the Ca2+ retention capacity of the liver mitochondria isolated from 3-month-old NAR was about 50% that of the control. Interestingly, the assessment of this variable in 21-day-old NAR and SDR indicated that the mitochondrial Ca2+ retention capacity was preserved at this age. A 20% decrease in mitochondrial nitrosothiol content and a 30% increase in cyclophilin D expression were observed in NAR liver mitochondria. None of the variables related to mitochondrial redox state differed between the controls and NAR, i.e., namely the contents of reduced mitochondrial membrane protein thiol groups and total glutathione, H2O2 release rate, and NAD(P)H reduced state. We conclude that the higher expression of cyclophilin D, a major component in the mitochondrial permeability transition process, and decreased nitrosothiol content in NAR mitochondria may underlie their lower Ca2+ retention capacity
Doutorado
Biologia Estrutural, Celular, Molecular e do Desenvolvimento
Doutor em Ciências
37
Nicolas-Simonnot, Marie-Odile. "Contribution à l'étude de la chromatographie frontale des protéines par échange d'anions : Application à l'albumine du serum bovin bovin." Vandoeuvre-les-Nancy, INPL, 1991. http://docnum.univ-lorraine.fr/public/INPL_T_1991_NICOLAS_SIMONNOT_M_O.pdf.
Full textAbstract:
La chromatographie d'échange d'anions mettant en jeu une protéine fait intervenir simultanément plusieurs phénomènes : l'échange d'ions proprement dit, ainsi que d'autres réactions, essentiellement de dissociation, en phase liquide ou solide. La démarche adoptée ici consiste à découpler toutes les contributions et à les examiner séparément, avant de les regrouper dans un modèle global. On étudie le comportement des supports échangeurs d'ions faibles en fonction de l'environnement ionique, les interactions entre les électrolytes faibles (tampons de pH) et les échangeurs d'anions, les interactions entre la protéine (albumine du sérum de bovin) et la solution (modélisation des courbes de dosage), et les interactions entre la protéine et des échangeurs d'anions (mesures d'isothermes en réacteur ferme et expériences en colonne en milieu tamponné ou non). On propose un modèle de la protéine (au niveau de l'échange d'ions), dont le comportement global s'approche de celui d'un électrolyte faible. Avant d’aborder les expériences en colonne avec une protéine-modèle (albumine de sérum bovin), on analyse les interactions entre cette protéine et la solution (modélisation de courbes de dosage). De même, on étudie les interactions entre la protéine et des échangeurs d’anions par la mesure d’isothermes dans différentes conditions. Enfin, des expériences de chromatographie frontale sont présentées. On commence par des systèmes « simples » du point de vue de l’échange d’ions (échanges binaires ou ternaires, en milieu non tamponné), avant de travailler en milieu tampon (où toutes les contributions sont mêlées). L’interprétation de ces expériences nous conduit à proposer un mécanisme d’échange. On montre que le comportement global de la protéine s’approche de celui d’un électrolyte faible, ce qui constitue un point de départ de vue de l’élaboration d’un modèle
38
Tasleem-Tahir, Ayesha. "Analyse du protéome de l'albumen et des couches périphériques du grain de blé (Triticum aestivum L.) en développement : vers une intégration des données avec le transcriptome." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2012. http://tel.archives-ouvertes.fr/tel-00923145.
Full textAbstract:
Le blé est la seconde céréale la plus produite dans le monde. Il constitue une importante source de denrées alimentaires et de beaucoup d'autres usages industriels. La compréhension des mécanismes impliqués dans le développement du grain de blé est fondamentale pour développer des blés à valeur ajoutée. La physiologie du grain de blé et les mécanismes moléculaires impliqués dans son développement nécessitent d'être mieux connus et ces connaissances pourront être très utiles pour l'amélioration du blé mais aussi des autres céréales. L'approche protéomique a été aussi utilisée dans ce contexte mais aucun travail n'avait jusqu'ici été réalisé sur la totalité des phases de développement des tissus et sur des intervalles de temps très courts. La caractérisation des changements d'expressions protéiques dans les couches périphériques du grain et de l'albumen est présentée dans cette étude. Nous avons utilisé les grains de Triticum aestivum de la variété Récital, cultivés à l'INRA de Clermont-Ferrand. Les grains ont été prélevés tous les 50°C jour (°Cj) depuis la fécondation jusqu'à la maturité sur 15 stades de développement pour les couches périphériques et sur 21 stades pour l'albumen amylacé. Pour chaque échantillon, les couches périphériques des grains ont été disséquées et les protéines totales extraites. L'analyse des protéines en électrophorèse bidimensionnelle puis par spectrométrie de masse MALDI-TOF a permis d'identifier via l'interrogation des bases de données, 207 protéines différentiellement exprimées sur 15 stades de développement (0°Cj-700°Cj). Ces protéines ont ensuite été classées en 16 classes fonctionnelles. L'analyse en cluster a révélé 5 profils d'expression au cours du temps. Parallèlement, l'albumen amylacé a été isolé des grains et les protéines métaboliques de ce tissu extraites. Après électrophorèse bidimensionnelle des protéines, 487 protéines variant significativement dans l'albumen sur l'ensemble des stades de développement (0°Cj-1006°Cj) ont été identifiées par utilisation de la LC-MS. Les protéines ont été réparties sur neuf profils d'expression et 17 fonctions biochimiques. Le protéome des couches périphériques a ensuite été comparé au protéome de l'albumen dans le but de comprendre si l'évolution des processus biochimiques diffère dans chacun de ces tissus. Au final, nous avons optimisé l'intégration des données protéomiques avec celles du transcriptome (en se focalisant sur les protéines du métabolisme carboné). Seulement 32% des profils d'expression protéome/transcriptome montrent une corrélation significative au cours du développement (152°Cj-700°Cj). Les profils d'expression des enzymes ont été comparés sur les deux niveaux. Ils devraient permettre de distinguer les processus régulés au niveau du transcriptome de ceux régulés au niveau du protéome. L'ensemble de ces données pourra être compilé dans une base de données propre de la variété Récital et utilisé comme référence dans l'étude des maladies et des stress abiotiques des tissus du grain de blé en développement.
39
Švachová, Michaela. "Experimentální analýza utváření mazacího filmu v náhradách kyčelního kloubu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241180.
Full textAbstract:
This diploma thesis deals with an experimental analysis of lubricant film formation in hip joint replacements. The main objective is to clarify the effect of mean speed, slide-to-roll ratio, and material of femoral head on the development of film thickness, focusing on the role of particular constituents contained in model synovial fluid, such as albumin and -globulin. For this purpose, a model ball-on-disc configuration was applied, while the development of lubricant film was evaluated using the combination of fluorescent microscopy and optical interferometry. To better understand the process, coefficient of friction between implant surfaces was later investigated as well. The effect of material, slide-to-roll ratio, mean speed and model fluid composition was analysed. Results indicate that the main parameter, influencing the character of film formation, is slide-to-roll ratio. Under most conditions, the dominant constituent responsible for the film thickness development was albumin. Coefficient of friction is affected mainly by the material of implant. The thesis contains original scientific results extending the knowledge in the area of hip joint biotribology.
40
Penteado, Flora Cristina Lobo [UNESP]. "Indução da diferenciação hepatocítica a partir de células-tronco mesenquimais isoladas da medula óssea e da retina humanas." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/103071.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:32:22Z (GMT). No. of bitstreams: 0
Previous issue date: 2008-03-17Bitstream added on 2014-06-13T19:43:01Z : No. of bitstreams: 1
penteado_fcl_dr_arafcf.pdf: 1008387 bytes, checksum: 40b22d48514b2c755f67d69d9ae8cff6 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
Alguns trabalhos realizados recentemente relatam que as células-tronco mesenquimais (CTM) podem ser induzidas à aquisição de marcadores hepatocíticos pelo transplante em modelos animais de dano hepático, ou pelo cultivo in vitro com fatores de crescimento e citocinas. O presente trabalho teve por objetivo avaliar o comportamento das CTM frente à indução da diferenciação hepatocítica. As CTM foram isoladas da medula óssea de quatro doadores saudáveis, caracterizadas e submetidas ao protocolo de indução à diferenciação hepatocítica in vitro e in vivo. As células induzidas in vitro apresentaram mudanças na sua morfologia, mostrando a morfologia semelhante à do hepatócito, porém, o perfil imunofenotípico não foi modificado. As células induzidas também não apresentaram o aumento dos transcritos de albumina, citoqueratina 18 e citoqueratina 19 quando analisadas por RT-PCR em tempo real, e não alteraram a expressão de albumina, citoqueratina 18 e alfafetoproteína como demonstrado por imunofluorescência. Quando analisadas in vivo, as CTM demonstraram o potencial migratório para o tecido hepático danificado de camundongos imunodeficientes. Em conjunto, os resultados sugerem que as CTM da medula óssea não são capazes de se diferenciar em hepatócitos quando estimuladas in vitro pela metodologia utilizado neste trabalho, mas são capazes de migrar para o tecido hepático danificado in vivo, o que sugere o seu papel no reparo do fígado. A contribuição para o reparo pode estar associada com o efeito parácrino dessas células.
Some recently works have been reported that mesenchymal stem cells (MSC) can be induced to the acquisition of hepatocytic markers for the transplant in animal models of liver damage, or for the in vitro culture with growth factors and cytokines. The present work aim is to evaluate the behavior of the MSC in front of the induction of the hepatocytic differentiation. The MSC was isolated from the bone morrow of 4 normal donators, characterized and submitted to the protocol of in vitro and in vivo induction of hepatocytic differentiation. The in vitro induced cells showed morphology changes acquiring hepatocytes-like morphology. However, the immunophenotypic profile of those cells was not modified. The induced cells did not present increase of the albumin, cytokeratin 18 and cytokeratin 19 transcripts, when analyzed by real time RTPCR. The expression of albumin, cytokeratin 18 and alpha foetoprotein was also not modified as demonstrated by immunofluorescence. In vivo, the MSC have demonstrated the migratory potential for the damaged liver of immunodeficient mice. Together, the results suggest that the bone morrow MSC are not capable of in vitro hepatocytic differentiating according to the approach in this work, but are capable to homming into damaged hepatic tissue in vivo. This migration capacity suggests their role in the repair mechanisms.
41
Silva, Marcelo Anselmo Oseas da 1982. "Avaliação e caracterização de sistemas baseados em ponto nuvem visando a remoção de albumina do plasma sanguineo." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248577.
Full textAbstract:
Orientador: Marco Aurelio Zezzi ArrudaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
Made available in DSpace on 2018-08-10T13:14:37Z (GMT). No. of bitstreams: 1 Silva_MarceloAnselmoOseasda_M.pdf: 1369513 bytes, checksum: 35e33836144e52420b1164f512aa97e9 (MD5) Previous issue date: 2008
Resumo: Nesta dissertação foi estudado o comportamento de partição da albumina, proteína presente em elevada concentração no plasma sangüíneo e que interfere na determinação em diversas técnicas analíticas. No estudo efetuado foram avaliados diferentes sistemas aquosos de duas fases, explorando um fenômeno denominado ponto nuvem. Tais sistemas empregam surfactantes, sob condições experimentais específicas, obtendo-se a formação de duas fases imiscíveis: uma rica e outra pobre em tensoativo. Observou-se que devido às características hidrofílicas da albumina, bem como à dimensão dos agregados formados, sua extração para fase rica em tensoativo apresenta valores de coeficiente de partição que não ultrapassam 0,66 o que representa uma eficiência de extração de ca.40%. A extração da proteína apresentou-se viável mediante a utilização de uma mistura composta por um tensoativo não-iônico (Triton® X-114), que possibilita a separação de fases em temperatura biocompatível, na presença de outro tensoativo iônico (dodecil sulfato de sódio - SDS), que atua favorecendo as interações eletrostáticas entre os agregados e as moléculas protéicas, desde que se trabalhe em meio com pH abaixo de 5,0. Análises de dicroísmo circular complementaram o estudo e fornecerem evidências de que a aplicação do sistema baseado na mistura composta por Triton® X-114 e SDS causava desnaturação parcial da proteína, o que não inviabilizou sua aplicação para extração da mesma em uma amostra real. A eficiência deste sistema foi, então, avaliada para a remoção de albumina em plasma sangüíneo. Um coeficiente de partição de 1,1 foi obtido, indicando que ca.51% das proteínas encontravam-se na fase rica em tensoativo. As amostras submetidas ao procedimento de extração também foram avaliadas frente à técnica de eletroforese em gel, sendo que a fase pobre em sufactante apresentou um perfil eletroforético mais detalhado quando comparada a uma amostra que não foi submetida ao procedimento proposto. Já na fase rica em surfactante, foi observada a presença majoritária de albumina e, em menor concentração, outras proteínas de grande abundância no plasma tais como imunoglobulina G e transferrina. Por fim, o método apresentou desempenho semelhante ao de sistemas disponíveis comercialmente para remoção de albumina, tal como o sistema da Millipore®, apresentado neste trabalho
Abstract: In this work the partition behavior of albumin was studied, which is found at high concentrations in blood plasma, which interferes in many analytical techniques determinations. The present study evaluated different aqueous two-phase systems, exploiting a phenomenon called of cloud point. These systems employ surfactants under specific experimental conditions, enabling formation of two immiscible phases: one rich and another poor in surfactant. Due to the hydrophilic characteristcs of albumin, as well as its aggregate dimensions, its extration to the surfactant rich phase presented partition coefficients lower than 0.66, representing and extraction efficiency of ca. 40%. Protein extraction was feasible by applying a mixture comprised of a nonionic surfactant (Triton® X-114), which allowed the phase separation at biocompatible temperatures, and an ionic one (sodium dodecylsufate - SDS), wich promotes eletrostatic interactions between aggregates and protein molecules, since the extraction procedure is carried out at pH 5.0. Circular dichroism analysis complemented the study and it showed that a system based on a Triton® X-114 and SDS mixture causes partial protein denaturation, but its application for a real sample is feasible. The efficiency of this was evaluated for albumin removal from blood plasma. A partition coefficient of 1.1 was obtained, indicating that ca. 51% of proteins were contained in the surfactant rich phase. Albumin depleted samples were submitted to gel eletrophoresis and the surfactant poor phase presented a more detailed gel electrophoresis profile, when compared with a crude sample. The surfactant rich phase reveled that albumin is the predominant protein present, but it is possible to find other highly concentrated plasmatic proteins including immunoglobulin G and transferrin. Finally, the method presented similar performance when compared with commercially available systems for albumin removal, such as the Millipore® system, wich was also evaluated in this work
Mestrado
Quimica Analitica
Mestre em Química
42
Castro, Camila Cristina de Lima. "Conjugados de ovalbumina e albumina bovina com desferrioxamina e suas interações com íons metálicos." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-21062017-091716/.
Full textAbstract:
O ferro é essencial para a vida do ser humano, desempenhando um papel fundamental no metabolismo. Contudo, quando não armazenado em compartimentos biológicos adequados, o metal apresenta um potencial tóxico ao organismo, uma vez que contribui para a formação de espécies reativas de oxigênio. A sobrecarga de ferro é uma condição desfavorável para portadores de algumas disfunções genéticas, como a hemocromatose, ou de anemias crônicas que requeiram transfusões de sangue periódicas, como é o caso da talassemia. Os fármacos atuais que controlam a patologia, como a desferrioxamina (DFO), requerem infusão subcutânea lenta, causando desconforto em pacientes e podendo trazer um série de complicações, como insuficiência hepática e renal. A modificação dessas moléculas com biopolímeros é uma proposta para minimizar efeitos colaterais e aumentar a biodisponibilidade do fármaco no organismo. Dentre esses biopolímeros, destacam-se as albuminas proveniente do soro bovino (BSA) e do ovo (OVA), que têm baixa toxicidade, baixo custo e abundância de sítios reativos, que quando modificados, favorecem reação com a desferrioxamina. Como resultado, houve a reação dos biopolímeros com a desferrioxamina, com mudanças em suas estruturas secundárias e possível dimerização, resultando na formação de conjugados possuem afinidade com íon ferro e capacidade antioxidante semelhante ao fármaco original, características que tornam os compostos bons candidatos a uma alternativa à terapia de quelação. Os conjugados BSA-DFO e OVA-DFO podem reagir, além do ferro, com gadolínio, fazendo com o que os complexos tenham uma potencial aplicação como agentes de contraste em ressonância magnética de imagem (MRI). Neste trabalho, vimos que o complexo entre Gd(III) e BSA-DFO apresentou uma relaxatividade de 52,92 s-1 mM-1 para T2 e 45,37 s-1 mM-1 para T1 , um valor bem superior aos fármacos disponíveis no mercado, que apre-sentam relaxatividade entre 4 e 5 s-1 mM-1, o que foi explicado por sua elevada massa molecular, indicando que poderia ter bons efeitos na qualidade de MRI, com menores doses.Iron is essential for human life, playing a fundamental role in metabolism. However, when not stored in appropriate biological compartments, the metal presents a toxic potential to the body, contributing to the formation of reactive oxygen species (ROS). Iron overload is an unfavorable condition for people with certain genetic disorders, such as hemochromatosis, or chronic anemias that require periodic blood transfusions, as thalassemia. Current drugs that control the pathology, as desferrioxamine, require slow subcutaneous infusion, causing discomfort in patients and may lead to a number of complications, such as hepatic and renal failures. As a result, the biopolymers were reacted with desferrioxamine, with changes in their secondary structures and possible dimerization, resulting in the formation of conjugates with iron ion affinity and antioxidant capacity similar to the original drug, characteristics that make the compounds good candidates for an alternative chelation therapy As a result, the reaction of the biopolymers with desferrioxamine caused a change in the secondary structure, with possible formation of dimers and showing different mobility when exposed to an electric potential difference. Not all polymer chains have reacted with DFO, however BSA-DFO complex has antioxidant capacity similar to the original drug. The BSA-DFO and OVA-DFO conjugates can react, in addition to iron, with gadolinium, making the complexes potential contrast agents for magnetic resonance imaging (MRI). In this work, the complex between Gd(III) and BSA-DFO presented a relaxativity of 52,92 s-1 mM-1 for T2 and 45,37 s-1 mM-1 for T1, values higher than the available drugs in the market (4 - 5 s-1 mM-1) which was explained by the high molecular weight, indicating a good effects on the quality of MRI, with lower doses.
43
Venturini, Diego [UNESP]. "Síntese do dímero da vanilina, desenvolvimento de sonda susceptível a dicroísmo circular induzido e sua aplicação para caracterização de sítios de ligação em albumina." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150438.
Full textAbstract:
Submitted by Diego Venturini null (diego.venturini@lpnet.com.br) on 2017-04-26T03:06:48Z
No. of bitstreams: 1
dissertação defesa FINAL.pdf: 3454973 bytes, checksum: 46340a211534e710264ebdb1e5d788ef (MD5)Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-26T12:43:24Z (GMT) No. of bitstreams: 1 venturini_d_me_bauru.pdf: 3454973 bytes, checksum: 46340a211534e710264ebdb1e5d788ef (MD5)
Made available in DSpace on 2017-04-26T12:43:24Z (GMT). No. of bitstreams: 1 venturini_d_me_bauru.pdf: 3454973 bytes, checksum: 46340a211534e710264ebdb1e5d788ef (MD5) Previous issue date: 2017-03-23
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A albumina é a proteína solúvel mais abundante no sangue e desempenha um papel crítico na manutenção da pressão osmótica e no transporte de substâncias. A divanilina apresenta propriedades antioxidantes e pode ser usada como intensificador de sabor e cremosidade nos alimentos. Em nosso trabalho realizamos um estudo abrangente sobre a interação da divanilina com a albumina do soro bovino (BSA) aplicando técnicas de fluorescência molecular e dicroísmo circular (CD) para determinar a constante de ligação, as características físico-químicas de suas interações e utilizar a divanilina como sonda suscetível a dicroísmo circular na discriminação de sítios de ligação na albumina a partir do monitoramento do sinal de Dicroísmo Circular Induzido (ICD). Os resultados obtidos indicaram que a divanilina pode se ligar aos sítios I e II, mas liga-se preferencialmente ao sítio de drogas I da BSA com constante de associação (Ka) de 3,33, 2,83, 2,03x105 M-1, em temperaturas de 298, 308 e 318 K, respectivamente. Esses valores foram cerca de 4 vezes mais elevados em comparação com a vanilina. Os valores obtidos de energia livre de Gibbs, variação de entalpia e entropia para a ligação a partir da equação de Van't Hoff foram de -31,5 kJ/mol, -19,42 kJ/mol e 40,8 J/mol.K-1, respectivamente, demonstrando que as forças principais que atuaram para a estabilização do complexo foram ligações de hidrogênio e interações hidrofóbicas. Em presença de BSA a divanilina tornou-se uma molécula quiral, fato evidenciado pelo seu espectro de dicroísmo circular induzido. A quiralidade axial foi teoricamente confirmada a partir do estudo das conformações mais estáveis adotadas pela divanilina usando a Teoria Funcional da Densidade (DFT). Os estudos de Docking molecular confirmaram a estrutura conformacional a qual a divanilina se ligou na BSA sendo a anti-aS com ângulo diedro entre 230º e 241º. A preferência pelo sítio I também pôde ser confirmada pelo docking devido a energia conformacional apresentada para a estrutura da divanilina quando inserida nesse sítio, sendo de -63,1 Kcal/mol enquanto que no sítio 2 a energia obtida foi de -59,7 Kcal/mol.
The albumin is the most abundant soluble protein in blood and plays a critical role in maintaining the osmotic pressure and transport of substances. The divanillin has antioxidant properties and can be used as flavor enhancer in food and creaminess. In this work, we carried out a comprehensive study on the interaction of divanillin with bovine serum albumin (BSA) applying molecular fluorescence techniques and circular dichroism (CD) to determine the binding constant and the physicochemical characteristics of their interactions and use divanillin as susceptible probe circular dichroism in discrimination of albumin binding sites from the ICD signal monitoring. The results indicated that divanillin can bind to sites I and II, but preferentially binds to site I of drugs in BSA with association constant (Ka) 3.33, 2.83, 2.03x105M-1, at temperatures (298, 308, 318K) respectively. These values were about 5 times higher compared to vanillin. The values of Gibbs free energy, enthalpy and entropy changes for the connection from the van't Hoff equation were -31,5 kJ/mol, -19,42 kJ/mol and 40,8 J/mol.K-1, respectively, showing that the main forces that have acted to stabilize the complex were hydrogen bonds and hydrophobic interactions. In the presence of BSA, divanillin became a chiral molecule as evidenced by its induced circular dichroism spectrum. The axial chirality was theoretically confirmed from the study of the most stable conformations adopted by divanillin using the Functional Theory Density (DFT). Axial chirality was theoretically confirmed from the study of the more stable conformations adopted by divanilin using the Functional Density Theory (DFT). Molecular docking studies confirmed the conformational structure to which divanilin bound in BSA with anti-aS having a dihedral angle between 230° and 241°. The preference for site I can also be confirmed by docking due to the conformational energy presented for the divanilin structure when inserted at that site, being -63.1 Kcal/mol while at site 2 the energy obtained was -59.7 Kcal/mol.
44
Young, Eleanor Dawn, and ellie@goldstreetstudios com au. "Mechanisms of Controlling Colour and Aesthetic Appearance of the Photographic Salt Print." RMIT University. Applied Science, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080901.142948.
Full textAbstract:
Abstract The salt print is an important part of photography, both in its historic value and in the tonal range it can provide. This tonal range is greater than any other photographic printing process available to date attributed to the inherent masking ability of the metallic silver. However the intrinsic production problems have made it a 'forgotten' process. There are five key problems. 1. The difficulties in achieving the potential extensive tonal range. 2. The varying colour of the print. 3. Staining that appears in the print, during and after processing. 4. Instability and longevity of the salt print. 5. Contradictory and inaccurate information in material published on the salt print. Although the emphasis of the research is on exploring and controlling the colour and tonal range, the staining problems and stability of the print are also addressed. The materials used for contact negatives today vary in both capture and output, from analogue film processed in the traditional wet darkroom to a variety of transparent film printed from digital files. Inadequate density and tonal range can affect all types of negatives. To provide sufficient exposure time for the salt prints extended tonal range adjustments to the negative were necessary. These long exposures then converted sufficient silver salts to the image making metallic silver, utilising the intrinsic self-masking process. Ultimately this research has uncovered ways to control colour and tonal range and certain aesthetic qualities of the salt print, while simultaneously resolving some of the conflicts in published information. Accurate and consistent methods of processing eliminate staining, providing some stability to the print. The activities and steps carried out to make a salt print are manual; precise duplication is therefore almost unattainable. Nevertheless, although tests on a densitometer may display numeric differences, visual differences are barely noticeable.
45
Westley, Chantel Barbara, and chantel westley@flinders edu au. "The distribution, biosynthetic origin and functional significance of Tyrian purple precursors in the Australian muricid Dicathais orbita (Neogastropoda: Muricidae)." Flinders University. Biological Sciences, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20090414.153942.
Full textAbstract:
Information on the biosynthetic origin and functional advantage of marine mollusc natural products is not only essential to our understanding of chemical ecology, but to the development and responsible production of therapeutic agents. As demonstrating in situ activity is methodologically hindered, functions inferred by in vitro activity have been assumed for many secondary metabolites. The anatomical and ontogenetic distribution of natural products can not only provide information on the biosynthesis and storage of metabolites, but identify selective pressures likely to affect survivorship at a specific life stage. Thus, dissection and chemical analysis of distinct tissues, in combination with histochemistry may offer a valuable approach.
Marine gastropods of the Muricidae are renowned for the ancient dye Tyrian purple, which evolves from choline esters of bromoindoxyl sulphate in the hypobranchial gland through a series of enzymatic and photo-oxidative reactions. Prochromogen hydrolysis by arylsulphatase liberates neuromuscular active choline esters and cytotoxic bromoindole precursors, which also occur in muricid egg masses. Although visual accounts of dye pigments in the muricid gonoduct suggest precursors may be incorporated into egg masses from a maternal source, their biosynthetic origin and the evolutionary significance of the hypobranchial gland is unknown. Thus, the Muricidae, and in particular Dicathais orbita upon which most previous research has been focused, is an ideal model for this novel approach to natural product research.
To confirm observations of dye pigments in muricid gonoducts and gain an understanding of their anatomical distribution, a liquid chromatography-mass spectrometry (LC-MS) method was developed to simultaneously quantify pigments, precursors and the prochromogen, tyrindoxyl sulfate. The prochromogen was not only detected in albumen and capsule gland extracts, but bioactive intermediates and the dye 6,6-dibromoindigo were also present in the latter. These findings provided preliminary evidence for the maternal provision of prochromogens in egg masses of D. orbita and identified regions within which to conduct histochemical investigations. Tyrindoxyl sulphate was also detected in male prostate gland extracts, along with the dibromoindigo isomer, 6,6-dibromoindirubin and its oxidative precursor, 6-bromoisatin. This not only implies physiological differences exist between male and female gonoducts, but that these secondary metabolites are not solely intended for egg masses and may hold significance throughout the life cycle.
Histomorphological inspection of the pallial gonoduct-hypobranchial gland complex was conducted over the annual cycle to determine a mechanism for precursor transfer between these structures. Although an anatomical connection was not detected, the secretions of two hypobranchial cell types thought to be involved in Tyrian purple synthesis were of remarkable biochemical similarity to those of various capsule and albumen gland lobes. Together these findings implied the potential for natural product synthesis within the pallial gonoduct of D. orbita.
To establish the role of these glandular lobes in the incorporation of intracapsular fluid and capsule laminae, identical histochemical techniques were applied to transverse capsule wall sections. Biochemical correlations not only provided a simple method of deciphering the complex process of encapsulation in neogastropods, but effectively identified the destination of gonoduct secretions in egg capsules of D. orbita. Comparisons of capsule and gonoduct biochemistry revealed that the intracapsular fluid and inner capsule wall are secreted by the posterior capsule gland lobe, the middle lamina by the lateral lobes and the outer layers by the dorsal lobe, albumen and pedal glands.
Investigation into the location of regulatory enzymes and precursors was conducted to establish the biosynthetic origin of Tyrian purple prochromogens and mechanisms governing bioactive precursor synthesis. Novel histochemical techniques for the localization of bromoperoxidase, the enzyme thought to facilitate prochromogen bromination, and tyrindoxyl sulphate were developed and applied to gonoduct, hypobranchial gland, and encapsulated larvae sections. Standard staining reactions for the indole precursor, tryptophan, and arylsulphatase were also applied. The histochemical approach adopted revealed that tyrindoxyl sulphate is de novo biosynthesized through the post-translational bromination of dietary derived tryptophan. Two biosynthetic sites were identified, one related to hypobranchial secondary metabolism and the second of significance to the presence of bioactive precursors in muricid egg masses.
Tryptophan is stored within secretory cells of the lateral hypobranchial epithelium and once exocytosed, is united with bromoperoxidase from supportive cells to form tyrindoxyl sulphate. Prochromogen synthesis also occurs in the subepithelial vascular sinus for storage and secretion by medial hypobranchial secretory cells. Bioactive precursor synthesis on the epithelial surface is regulated by the liberation of arylsulphatase from adjacent supportive cells. These findings not only provide evidence for de novo biosynthesis of Tyrian purple precursors, but are first account of natural product biosynthesis within the gastropod hypobranchial gland. Together these findings imply a naturally selected function for the synthesis of bioactive indoles in hypobranchial gland secretions of the Muricidae and Gastropoda.
Tyrindoxyl sulphate is also transported within the vascular sinus to lateral and dorsal capsule gland lobes where bromoperoxidase and arylsulphatase also occur. Arylsulphatase was also detected within the albumen gland, which along with the posterior capsule gland lobe, acts as a storage site for dietary tryptophan. Thus, tyrindoxyl sulphate and the constituents for prochromogen and precursor biosynthesis are introduced to intracapsular fluid and capsule laminae by the capsule gland. Histochemistry in combination with LC-MS revealed an identical biosynthetic profile within larval vitellus, which is elaborated during oogenesis and may also receive secretions from the albumen gland. Due to the absence of a hypobranchial gland in veligers, it appears that pelagic larvae rely on vitelline natural products until settlement and metamorphous. These findings together with the in situ antimicrobial activity of bromoindoles suggest Tyrian purple precursors are incorporated into muricid egg masses as a maternal investment in larval defence against pathogens.
The results of this investigation clearly highlight the benefits of adopting a histochemical approach to natural product research. This novel alternative to radioisotopes and in situ demonstration of bioactivity, can not only aid in the elucidation of secondary metabolic pathways and chemically mediated interactions, but identify mechanisms of metabolite regulation and differentiate between biosynthetic and storage tissues. Apart from providing insight into the ecological significance of muricid secondary metabolites, the biosynthetic information provided is valuable to our understanding of chemical phylogeny and biosynthetic enzyme sequencing for the environmentally sound development of natural products as biomedical agents.
46
Saunders, J. E. "Drug targeting using albumin microspheres." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381061.
Full text
47
Sen, Sambit. "Albumin dialysis in liver failure." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1445935/.
Full textAbstract:
Albumin-bound toxins accumulating due to hepatic dysfunction are believed to lead to multi-organ dysfunction in liver failure, contributing to a poor prognosis. Thus, liver support devices utilising albumin dialysis have been developed, and the Molecular Adsorbents Recirculating System (MARS) is the one being investigated most thoroughly. This series of studies was designed to systematically investigate its role in liver disease. The initial studies evaluated its clinical impact in patients with severe alcoholic hepatitis. MARS therapy was safe and feasible. Improvement of hyperbilirubinaemia and hepatic encephalopathy were the most consistent findings. Effects on systemic haemodynamics or renal function were insignificant. A rapid and sustained portal hypotensive effect was observed, suggesting that albumin dialysis may be a useful adjunctive therapy for variceal bleeding in patients with liver failure. An apparent reduction in mortality was observed, though the studies were not powered to evaluate survival. The next study investigated the pathophysiological basis of these changes in acute- on-chronic liver failure. Albumin dialysis improved encephalopathy, accompanied by reduced oxidative stress, without significant changes in arterial ammonia or cytokines. The improvement in encephalopathy independent of ammonia highlights the importance of other mediators such as oxidative stress in its pathogenesis. A porcine model of acute liver failure (ALF) was used to study the effect of MARS on the cerebral changes. Attenuation of intracranial hypertension was observed, as was a reduction of cerebral oedema (in white matter), without alterations of arterial ammonia, cerebral blood flow, cytokines or oxidative stress. Thus, while hyperammonaemia is probably essential for the initial development of cerebral oedema and intracranial hypertension in ALF, cerebral hyperaemia and inflammation are not. Regional differences exist for brain oedema, perhaps with therapeutic indications. Factors in addition to hyperammonaemia are also important. Finally, the effect of albumin dialysis on protein-bound drugs was studied. MARS efficiently removed both albumin-bound (phenytoin, midazolam) and non-albumin-bound (fentanyl) substances. The mechanism is probably by uptake of free drug, with constant re-equilibration of free and bound components. Albumin dialysis may be important in treating non-dialysable protein-bound substance intoxications. Therefore, albumin dialysis does bring about measurable biochemical and pathophysiological changes, translating to clinical improvements. Ongoing randomized controlled trials will provide a definitive answer regarding impact on mortality.
48
Łomzik, Michał Pawel. "Synthesis and characterization of hybrid drugs based on ruthenium complex moiety and biologically active organic compounds." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0338/document.
Full textAbstract:
L’objectif de cette thèse est de préparer et caractériser de nouveaux agents théranostiques potentiels à base de complexes de ruthénium portant des molécules biologiquement actives. Pour évaluer potentiel théranostique des nouveaux composés les propriétés de luminescence et la cytotoxicité ont été considérées. Quatre nouveaux ligands portant des substituants a activité biologique: 5-(4-4’-methyl-[2,2’-bipyridine]-4-ylbut-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone (L1), 3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L2), 5,5-dimethyl-3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L3) and [1-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)-2,5-dioxoimidazolidin-4-yl]urea (L4) ont été prepares, caractérisés et engagés dans la synthese des complexes de ruthénium correspondants. Six complexes ont été obtenus a partir du ligand L1 ([Ru(bpy)2(L1)]2+, [Ru(Mebpy)2(L1)]2+, [Ru(tBubpy)2(L1)]2+, [Ru(Phbpy)2(L1)]2+, [Ru(dip)2(L1)]2+, [Ru(SO3dip)2(L1)]2-) et trios a partir de L2, L3 and L4 ([Ru(bpy)2(L2)]2+, [Ru(bpy)2(L3)]2+, [Ru(bpy)2(L4)]2+) (bpy = 2,2’-bipyridine, Mebpy = 4,4’-dimethyl-2,2-bipyridine, tBubpy = 4,4’-tert-butyl-2,2’-bipyridine, Phbpy = 4,4’-diphenyl-2,2-bipyridine, dip = 4,7-diphenyl-1,10-phenantroline and SO3dip = 4,7-di-(4-sulfonatophenyl)-1,10-phenantroline). Les propriétés spectroscopiques et photophysiques des composés ont été étudiées. La présence des ligands L1-L4 conduit a une décroissance du rendement quantique et de la durée de vie de l’état excité en comparaison des complexes non substitués [Ru(bpy)3]2+. Des calculs DFT montrent que les ligands L1-L4 n’influencent pas la géométrie du complexe mais accroissent le niveau énergétique de la HOMO induisant des band gap HOMO-LUMO plus faibles. Les interactions entre les complexes et l’human serum albumin (HSA) ont été étudiées. Tous les complexes préparaés montrent une tres forte affinité pour HSA – La constante d’association 105 M-1s-1 témoigne de la formation d’adduits Ru-HSA stables. Il a aussi été démontré que les complexes de ruthénium se lient préférentiellement a la poche hydrophobe des protéine, située dans le site 1 de Sudlow dans le sous domaine II A. Des études préliminaires ont montré que les complexes de ruthénium préparés presentent une activité cytotoxique vis-à-vis de diverses lignées de cellules cancéreuses. Cette activité associée aux bonnes propriétés de luminescence (rendement quantique, durée de vie) fait des nouveaux complexes des candidats potentiels pour les applications théranostiquesThe main goal of this thesis was synthesis and preliminary characterization of novel ruthenium(II) polypyridyl complexes bearing biologically active molecules as potential theranostic agents. Luminescence for the diagnostic applications, and cytotoxicity for the anticancer, therapeutic applications are considered as the theranostic properties. Four new ligands containing biologically active moieties - 5-(4-4’-methyl-[2,2’-bipyridine]-4-ylbut-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone (L1), 3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L2), 5,5-dimethyl-3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L3) and [1-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)-2,5-dioxoimidazolidin-4-yl]urea (L4) were synthesized and characterized. The ligands were used to obtain nine novel ruthenium(II) polypyridyl complexes. Six complexes were synthesized with ligand L1 ([Ru(bpy)2(L1)]2+, [Ru(Mebpy)2(L1)]2+, [Ru(tBubpy)2(L1)]2+, [Ru(Phbpy)2(L1)]2+, [Ru(dip)2(L1)]2+, [Ru(SO3dip)2(L1)]2-) and three with ligands L2, L3 and L4 ([Ru(bpy)2(L2)]2+, [Ru(bpy)2(L3)]2+, [Ru(bpy)2(L4)]2+) (bpy = 2,2’-bipyridine, Mebpy = 4,4’-dimethyl-2,2-bipyridine, tBubpy = 4,4’-tert-butyl-2,2’-bipyridine, Phbpy = 4,4’-diphenyl-2,2-bipyridine, dip = 4,7-diphenyl-1,10-phenantroline and SO3dip = 4,7-di-(4-sulfonatophenyl)-1,10-phenantroline). The spectroscopic and photophysical properties of those complexes were determined. The presence of ligands L1-L4 in the structure of the complex decreased luminescence quantum yield and luminescence lifetime in comparison with unmodified [Ru(bpy)3]2+ complex. The theoretical calculations have shown that ligands L1-L4 do not have influence on ruthenium core geometry. However, they increased the energy of the HOMO that resulted in a shorter band gap. The simulated electronic absorption spectra were in a good agreement with the experimental data. The interactions between the studied ruthenium complexes and human serum albumin (HSA) were investigated. All studied Ru(II) complexes exhibited strong affinity to HSA with the association constant 105 M-1s-1, which suggests formation of Ru complex-HSA adducts. It was also determined that ruthenium complexes most likely bind to the hydrophobic pocket of protein, located in Sudlow’s site I in the subdomain II A. Preliminary cytotoxicity evaluation for the studied ruthenium complexes showed their cytotoxic activity towards cancer cell lines. Those results, together with good luminescence properties of the studied ruthenium complexes (luminescence lifetimes and luminescence quantum yield) make them interesting candidates for potential theranostic applications
49
Reis, Felipe Costa Claro. "Investigação química de complexos de coordenação dos antibióticos enrofloxacina e norfloxacina combinados ao íon Ru(III) e suas interações com biomoléculas alvo." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-18092014-101658/.
Full textAbstract:
Este trabalho tem como objetivo sintetizar e caracterizar um novo complexo mononuclear de rutênio (III) e enrofloxacina (enro, fármaco antibacteriano da família das fluoroquinolonas), [Ru(enro)3].nH2O. Foram testadas várias rotas sintéticas e apenas a partir de uma delas obteve-se o composto desejado. O produto foi caracterizado pelas técnicas espectroscópicas de absorção na região do UV-visível e do infra-vermelho. Através desta última técnica foi possível determinar o modo pelo qual a enrofloxacina se coordena ao íon rutênio: a coordenação ocorre de modo bidentado através do oxigênio da piridona e do oxigênio do grupamento carboxilato. Outro objetivo deste trabalho foi investigar a interação do complexo mononuclear de rutênio (III) e norfloxacina, [Ru(nor)3].nH2O, com a albumina de soro humano (HSA), através da técnica de luminescência. Mais especificamente pelo estudo da supressão da luminescência dos resíduos de triptofano, aplicando-se o modelo de tratamento da supressão bimolecular de Stern-Volmer. O estudo de supressão de fluorescência mostrou, por meio de espectros de emissão da HSA, que com o aumento da concentração do complexo [Ru(nor)3].nH2O na solução de HSA, ocorre uma redução gradual da luminescência da HSA, devido a alterações da conformação da proteína, que sugerem alteração do microambiente próximos aos resíduos de triptofano. A partir do tratamento dos dados pode-se determinar tanto K_sv quanto a constante cinética do processo de supressão, que mostraram uma dependência com a temperatura sugerindo como mecanismo predominante de supressão o mecanismo dinâmico. Porém essa conclusão foi revista a partir da determinação dos tempos de vida do estado excitado da HSA, e pode-se concluir que o mecanismo predominante à temperatura ambiente é o mecanismo estático, porém com o aumento da temperatura ocorre a predominância do mecanismo do tipo dinâmico. Através da determinação dos parâmetros termodinâmicos, concluiu-se que as interações entre a HSA e o complexo são espontâneas, e forças de van der Waals e ligações de hidrogênio estão envolvidas na ligação entre a HSA e o supressor.This work aims to synthesize and characterize a new mononuclear ruthenium (III) complex and enrofloxacin (enro, antibacterial drug of the fluoroquinolone family), [Ru(enro)3].nH2O. Several synthetic routes were tested, but only from one of them it was obtained the desired compound. The product was characterized by spectroscopic techniques of absorption in UV-visible and infra-red regions. Through this last technique, it was possible to determine the coordination mode of enrofloxacin to the ruthenium ion: the coordination occurs in a bidentate way through the pyridone oxygen and the oxygen of the carboxylate group. Another aim of this study was to investigate the interaction of mononuclear ruthenium (III) complex and the norfloxacin, [Ru(nor)3].nH2O, with the human serum albumin (HSA), through the technique of luminescence. More specifically, by the study of the quenching of luminescence of tryptophan residues, by applying the Stern-Volmers model of treatment of bimolecular suppression. The fluorescence quenching study showed, through the emission spectra of HSA, that increasing the complex concentration in HSA solution, there is a gradual reduction of the luminescence of HSA, due to the conformational changes of the protein that suggests the change of microenvironment near tryptophan residues. From the data processing it is possible to determine both K_sv and the kinetic constant of the suppression process, which showed temperature dependence, suggesting as the predominant mechanism of quenching the dynamic mechanism. However, this conclusion has been revised from the determination of the lifetimes of the excited state of HSA, and it can be concluded that the predominant mechanism at room temperature is the static mechanism, but with the temperatures increase, it occurs the predominance of the dynamic type mechanism. By determining the thermodynamic parameters, it was concluded that the interactions between HSA and the complex are spontaneous, and Van der Waals forces and hydrogen bonds are involved in the binding between HSA and suppressor.
50
Camargo, Cintia Ramos [UNESP]. "Caracterização espectral e computacional da interação de derivados de benzoil-tiraminas e albumina humana São José do Rio Preto 2017." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152036.
Full textAbstract:
Submitted by CINTIA RAMOS CAMARGO null (cintiaramoscamargo@gmail.com) on 2017-10-26T19:26:25Z
No. of bitstreams: 1
Tese _Cintia Ramos Camargo_.pdf: 5811868 bytes, checksum: a56e37c6cc9f843250f31549c5aa7e98 (MD5)Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-31T18:52:56Z (GMT) No. of bitstreams: 1 camargo_cr_dr_sjrp.pdf: 5811868 bytes, checksum: a56e37c6cc9f843250f31549c5aa7e98 (MD5)
Made available in DSpace on 2017-10-31T18:52:56Z (GMT). No. of bitstreams: 1 camargo_cr_dr_sjrp.pdf: 5811868 bytes, checksum: a56e37c6cc9f843250f31549c5aa7e98 (MD5) Previous issue date: 2017-09-18
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A folha de louro verde brasileira, uma especiaria muito apreciada na cozinha local (Aniba riparia, Lauraceae), contém compostos químicos que apresentam derivados de benzoíla chamados riparinas, que possuem propriedades anti-inflamatórias, antimicrobianas e ansiolíticas. No entanto, não está claro qual o tipo de interação que as riparins desempenham com qualquer alvo molecular. Como um alvo rentável, a albumina de soro humano (HSA) é uma das principais proteínas extracelulares, com uma capacidade excepcional para interagir com várias moléculas, e também desempenha um papel crucial no transporte, distribuição e metabolismo de uma grande variedade de ligantes endógenos e exógenos. Para delinear o mecanismo de interação HSA-riparina, a espectroscopia e os métodos computacionais foram aplicados de forma sinérgica. Uma avaliação através de espectroscopia de fluorescência mostrou que a emissão, atribuída ao Trp 214, a 346 nm, diminuiu com as titulações das riparinas. Observou-se um mecanismo de supressão estática na ligação das riparinas à HSA. Os experimentos de fluorescência realizados em 298, 308 e 318 K possibilitaram a realização de análises termodinâmicas que indicassem uma reação espontânea na formação do complexo (ΔG <0). O experimento do balanço entálpico-entrópico e com um cálculo de modelagem molecular revelou que interações hidrofóbicas, ligação de hidrogênio e interações não específicas estão presentes para as riparinas I - III com a HSA. O conjunto de resultados das mudanças da fração de fluorescência obtidos através de Schatchard não foi conclusivo ao estabelecer que tipo de cooperatividade esteja presente na interação. Para esclarecer o complexo HSA-riparinas, a abordagem de Hill foi utilizada para distinguir o índice de afinidade e a constante de ligação. Observou-se uma correspondência entre as estruturas moleculares das riparinas, devido à presença do grupo hidroxila no anel B, com parâmetros termodinâmicos e índice de afinidade. Riparin III realiza uma ligação de hidrogênio intramolecular, que afeta o coeficiente de Hill e a constante de ligação. Portanto, a presença de grupos hidroxila é capaz de modular a interação entre riparinas e HSA. Os experimentos de competição de sítio indicaram o sítio I como sendo o mais acessado, e as ferramentas de modelagem molecular reforçavam os resultados experimentais detalhando a participação de resíduos.
The green Brazilian bay leaf, a spice much prized in local cuisine (Aniba riparia, Lauraceae), contains chemical compounds presenting benzoyl-derivatives named riparins, which have anti-inflammatory, antimicrobial and anxiolytic properties However, it is unclear what kind of interaction riparins perform with any molecular target. As a profitable target, human serum albumin (HSA) is one of the principal extracellular proteins, with an exceptional capacity to interact with several molecules, and it also plays a crucial role in the transport, distribution, and metabolism of a wide variety of endogenous and exogenous ligands. To outline the HSA– riparin interaction mechanism, spectroscopy and computational methods were synergistically applied. An evaluation through fluorescence spectroscopy showed that the emission, attributed to Trp 214, at 346 nm decreased with titrations of riparins. A static quenching mechanism was observed in the binding of riparins to HSA. Fluorescence experiments performed at 298, 308 and 318 K made it possible to conduct thermodynamic analysis indicating a spontaneous reaction in the complex formation (ΔG<0). The enthalpy-entropy balance experiment with a molecular modeling calculation revealed that hydrophobic, hydrogen bond and non-specific interactions are present for riparin I - III with HSA. The set of results from fractional fluorescence changes obtained through Schatchard was inconclusive in establishing what kind of cooperativity is present in the interaction. To shed light upon the HSA-riparins complex, Hill’s approach was utilized to distinguish the index of affinity and the binding constant. A correspondence between the molecular structures of riparins, due to the presence of the hydroxyl group in the B-ring, with thermodynamic parameters and index of affinity were observed. Riparin III performs an intramolecular hydrogen bond, which affects the Hill coefficient and the binding constant. Therefore, the presence of hydroxyl groups is capable of modulating the interaction between riparins and HSA. Site marker competitive experiments indicated Site I as being the most suitable, and the molecular modeling tools reinforced the experimental results detailing the participation of residues.