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Síntese e avaliação biológica de glicodicetopiperazinas relacionadas a mucinas de células tumorais e parasitárias / Synthesis and biological evaluation of glycodiketopiperazines related to mucins from tumoral and parasite cellsTeixeira, Maristela Braga Martins 03 September 2010 (has links)
Mucinas são glicoproteínas altamente O-glicosiladas cuja principal característica estrutural é a presença de -GalNAc ligado aos resíduos hidroxilados de serina e treonina. Em alterações celulares malignas, esse núcleo é exposto como um antígeno carboidrato associado a tumor (Tn) e sua alta expressão em células cancerosas faz dele um alvo para o desenvolvimento de abordagens contra o câncer. Mucinas de Trypanosoma cruzi, agente etiológico da Doença de Chagas, apresentam -GlcNAc ligado à apoproteína, envolvido no processo de sialilação catalisado pela enzima fundamental trans-sialidase (TcTS) mediadora da invasão celular. Sendo o componente glicosídico do antígeno Tn um análogo estrutural e funcional de -GlcNAc, pode influenciar na atividade de TcTS, alvo terapêutico para a Doença de Chagas. Neste contexto, foram sintetizados glicopeptídeos lineares e cíclicos derivados de GalNAc mimetizando sua ocorrência em mucinas tumorais e parasitárias. Doadores e aceptores glicosídicos convenientemente protegidos foram preparados e ligados entre si com -estereosseletividade por dois métodos de glicosilação: perclorato/carbonato de prata (promotor clássico de referência) e brometo de mercúrio (promotor pela primeira vez utilizado para doadores glicosídicos do tipo azidocloreto). Os blocos de glicoaminoácidos obtidos foram acoplados a um segundo resíduo, formando glicodipeptídeos lineares inéditos, que originaram glicodicetopiperazinas funcionalizadas com -GalNAc, igualmente inéditas a literatura, mediante a etapa de desproteção/ciclização. Glicoaminoácidos intermediários contendo -GalNAc foram desprotegidos e submetidos a ensaios de cinética enzimática em TcTS, apresentando expressiva inibição de 57% a 79% da atividade da enzima. Os mesmos blocos foram avaliados quanto à citotoxicidade em células tumorais, apresentando entre 73% e 79% de morte celular na linhagem Jurkat e cerca de 30% na linhagem B16F10. Os resultados ensaios biológicos sugerem que os compostos de interesse preparados podem atuar como inibidores da enzima TcTS e agentes de citotoxicidade seletiva em células tumorais. / Mucins are heavily O-glycosylated glycoproteins which major feature being the presence of -GalNAc bound to hydroxylated protein residues of serine and threonine. In malignant cell transformation this core is exposed as a tumor associated carbohydrate antigen (Tn), and its high-level expression in cancer cells turns it into a target for developing anticancer approaches. Mucins from Trypanosoma cruzi, aetiologic agent of Chagas Disease, display -GlcNAc linking glycans to the apoprotein, involved in the sialilation process catalized by tran-sialidase enzyme (TcTS), essential cell invasion by the parasite. Being Tn antigen an structural and functional analogue of -GlcNAc, it may interfere on TcTS, a therapeutic target Chagas Disease. In this context, linear and cyclic glycopeptides containing GalNAc were synthesized, mimicking their natural occurrence in tumoral and parasite mucins. Glycosidic donors and acceptors, conveniently protected were prepared and bound to each other with -stereoselectivity, though two glycosylation methods: silver perchlorate/carbonate (classical reference promoter) and mercuric bromide (first used as a promoter for azidochloride donors). Glycoaminoacids building blocks obtained were coupled to a second residue, furnishing novel linear glycopeptides, which generated glicodiketopiperazines functionalized with -GalNAc, equally unpublished, upon deprotection/cyclization step. Intermediate -GalNAc-containing glycoaminoacids were deprotected and subjected to kinetic enzymatic assay on TcTS, showing expressive enzyme activity inhibition from 57% to 79%. The same compounds were assessed for cytotoxicity on tumoral cells, showing from 73% to 79% of death for Jurkat cells and about 30% for B16F10 cells. Biological results sugest that the prepared compounds of interest may act as TcTS enzyme inhibitors and selective cytotoxic agents on tumoral cells.
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Određivanje trans masnih kiselina u prehrambenim proizvodima gasnom hromatografijom-masenom spektrometrijom / Determination of trans fatty acids in foodstuffs by gaschromatography-mass spectrometryKravić Snežana 04 October 2010 (has links)
<p>U okviru doktorske disertacije optimizovani su uslovi određivanja<br />metilestara masnih kiselina, uključujući i trans izomere, primenom<br />kapilarne gasne hromatografije–masene spektrometrije, na<br />kapilarnoj koloni SP-2560 (dužina x unutrašnji prečnik: 100 m x<br />0,25 mm, debljina sloja stacionarne likvidne faze 0,20 μm,<br />biscijanopropil polisiloksan). Korišćenjem standarnih rastvora<br />metilestara masnih kiselina optimizovani su temperaturni program,<br />odnos razdeljivanja i uslovi akvizicije podataka SCAN tehnikom.<br />Razvijena je metoda za pripremu uzoraka u cilju određivanja sastava<br />masnih kiselina u prehrambenim proizvodima gasnom<br />hromatografijom–masenom spektrometrijom zasnovana na<br />istovremenoj mikrotalasnoj ekstrakciji i esterifikaciji (SMEE).<br />Validacija metode je izvedena poređenjem sa rezultatima dobijenim<br />gasnom hromatografijom–masenom spektrometrijom nakon<br />ekstracije po Soxhlet-u i derivatizacije masnih kiselina u metilestre<br />masnih kiselina. Rezultati dobijeni primenom razvijene i referentne<br />metode bili su statistički isti, kako u pogledu sastava masnih<br />kiselina, tako i efikasnosti ekstrakcije. Rezultati su pokazali da su<br />prednosti SMEE u odnosu na konvencionalnu metodu: kratko vreme<br />pripreme uzoraka i samim tim manja potrošnja energije, kao i<br />upotreba malih količina skupih organskih rastvarača. Dobro slaganje<br />rezultata dobijenih primenom referentne i metode zasnovane na<br />istovremenoj mikrotalasnoj ekstrakciji i esterifikaciji pokazuje da bi<br />se SMEE mogla primeniti kao rutinska metoda za pripremu uzoraka<br />prehrambenih proizvoda u cilju određivanja trans masnih kiselina<br />(TFA). Određen je sastav masnih kiselina, sa posebnim akcentom na<br />trans masne kiseline, u 273 uzoraka prikupljenih sa našeg tržišta u<br />periodu od juna 2006. do juna 2009. godine. Sadržaj trans masnih<br />kiselina u analiziranim uzorcima prehrambenih proizvoda, sirovina i<br />međuproizvoda koji se koriste u pekarskoj i konditorskoj industriji,<br />kretao se u veoma širokom intervalu, od 0,0% do čak 48,7%.<br />Prosečan sadržaj trans masnih kiselina iznosio je 0,2% u uljima,<br />6,5% u jestivim margarinima, 19,9% u margarinima za domaćinstvo,<br />9,8% u industrijskim margarinima, 24,3% u namenskim mastima,<br />10,8% u masnim punjenjima, 1,6% u mlečnim proizvodima, 10,9%<br />u slanom trajnom pecivu, 10,2% u čajnom pecivu, 6,3% u tvrdom<br />keksu, 11,0% u vafel proizvodima, 10,6% u čokoladnim<br />proizvodima i 9,2% u karamelama. Od ukupno 124 analizirana<br />uzorka, koja se ne koriste za direktnu upotrebu u ishrani (namenske<br />masti, masna punjenja, industrijski i margarini za domaćinstvo) 86<br />uzoraka (69,3%) sadrži više od 5% trans masnih kiselina, 25<br />(20,2%) sadrži manje od 5% TFA, dok u 13 uzoraka (10,5%) nije<br />detektovano prisustvo trans izomera. Od ukupno 140 analiziranih<br />uzoraka, koji se koriste za direktnu upotrebu u ishrani 74 uzoraka<br />(52,8%) sadrži više od 2% trans masnih kiselina, 20 (14,3%) sadrži<br />manje od 2% TFA, dok u 46 uzoraka (32,9%) nije detektovano<br />prisustvo trans izomera.</p> / <p>In this thesis, operating conditions for fatty acids determination,<br />including trans isomers, by capillary gas chromatography–mass<br />spectrometry, on capillary column SP-2560 (100 m x 0.25 mm, with<br />a 0.20 μm film thickness of biscyanopropyl polysiloxane liquid<br />phase) were optimized. Temperature program, split ratio and<br />condition of data acquisition by SCAN technique were optimized<br />using standard solutions of fatty acid methyl esters. A sample<br />preparation method based on simultaneous microwave assisted<br />extraction–esterification (SMEE) was developed for the<br />determination of the fatty acid composition of foodstuffs by gas<br />chromatography–mass spectrometry. The proposed sample<br />preparation method was validated by comparison with the reference<br />Soxhlet extraction method followed by derivatisation by methyl<br />ester formation and the same determination step. The fatty acid<br />compositions, as well as extraction efficiencies obtained by the use<br />of the proposed SMEE method and reference method were<br />statistically similar. The results showed that compared to the<br />conventional method, SMEE method offer the advantages of short<br />sample preparation time, low consumption of expensive organic<br />solvents and less energy consumption. This good agreement between<br />results provided, both by the SMEE and reference method,<br />demonstrates the usefulness of the former as the routine method for<br />the treatment of food samples prior to trans fatty acid analysis. The<br />fatty acid composition, and trans fatty acid content of 273 samples<br />collected from June 2006 to June 2009 year were determined. Trans<br />fatty acid content in the analysed samples of food products, raw<br />materials and intermediate products used in bakery and<br />confectionery industry was ranged in a very wide interval, from<br />0.0% to 48.7%. The average contents of trans fatty acids were 0.2%<br />in oils, 6.5% in the edible margarines, 19.9% in cooking margarines,<br />9.8% in industrial margarines, 24.3% in shortenings, 10.8 % in fat<br />fillings, 1.6% in dairy products, 10.9% in crackers, 10.2% in tea<br />cookies, 6.3% in biscuits, 11.0% in wafer products, 10.6% in<br />chocolate products and 9.2% in the caramels. From the total of 124<br />analysed samples, which are not used for direct human consumption<br />(shortenings, fat fillings, industrial and cooking margarines) 86<br />samples (69.3%) contained more than 5% trans fatty acids, 25 (20.2<br />%) contained less than 5% TFA, while 13 samples (10.5%) had an<br />undetectable levels of trans isomers. From a total of 140 analysed<br />samples, which are used for direct human consumption 74 food<br />samples (52.8%) contained more than 2% trans fatty acids, 20<br />(14.3%) contained less than 2% TFA, while 46 samples (32.9%) had<br />an undetectable levels of trans isomers.</p>
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Vulnerabilidade para o HIV em mulheres trans : o papel da psicologia e o acesso à saúdeCosta, Angelo Brandelli January 2015 (has links)
O objetivo deste estudo foi analisar a vulnerabilidade programática, social e individual para a infecção por HIV em mulheres trans. Para esse fim, realizaram-se quatro estudos. No primeiro estudo, a partir da análise crítica da escala de Masculinidade e Feminilidade (M) da versão brasileira da Escala de Personalidade de Comrey (CPS), recuperou-se o tratamento histórico que a psicologia feminista deu às ideias de sexo e gênero e seus desdobramentos. Além disso, apontou-se para uma concepção de gênero autodeterminada, não essencialista, pluralista e não patológica. Por fim, analisou-se como o CPS é mantido como medida psicológica válida no contexto brasileiro em paralelo, contraditoriamente, com a defesa da igualdade de gênero. O segundo estudo avaliou a prevalência de HIV em mulheres trans do sul do brasil que buscam cirúrgicas de redesignação genital e fatores associados. O terceiro, buscou conhecer as demandas e barreiras no acesso a serviços de saúde relativos ao HIV e específicos para pessoas trans em dois estados do Brasil - Rio Grande do Sul e São Paulo -, que iniciaram de forma pioneira o atendimento a essa população. Foram investigadas, ainda, as experiências de discriminação no contexto de saúde que impactavam o acesso à saúde em geral. Por fim, o quarto estudo, avaliou a eficácia de uma intervenção online multidimensional (educacional, afetiva e comportamental) para mudar as atitudes dos profissionais de saúde em relação a população LGBT. Encontrou-se que a psicologia brasileira precisa aderir a uma visão inclusiva da diversidade de gênero, que a prevalência de HIV em mulheres trans é alta e associada ao trabalho sexual, que há barreiras no seu acesso à saúde e, que o preconceito dos profissionais de saúde é alto, mas que intervenções para reduzi-lo são efetivas. Apontam-se diretrizes para psicologia reduzir a vulnerabilidade da população trans. / The aim of this study was to analyze the programmatic, social and individual vulnerability to HIV infection among trans women. For this aim, four studies were done. In the first study, a critical literature review of the Masculinity and Femininity (M) scale of the Brazilian version of Comrey Personality Scale (CPS) recovered the historical treatment that feminist psychology gave the sex and gender ideas and their developments. In addition, the studied pointed to a self-determined, not essentialist, pluralistic and not pathological gender conception. Finally, it was examined how the CPS is kept as valid psychological measure in the Brazilian context in parallel, paradoxically, to the defense of gender equality. The second study assessed the prevalence of HIV and associated factors in trans women from southern Brazil who seek sex reassignment surgery. The third study sought to evaluate the demands and barriers in access to health services related to HIV and specific to trans people in two states in Brazil - Rio Grande do Sul and São Paulo - that started in a pioneering way the care of this population. It also investigated the experiences of discrimination in the health context that impacted access to health care in general. Finally, the fourth study assessed the effectiveness of a multidimensional (educational, affective and behavioral) web-based intervention program to change Brazilian health care practitioners’ attitudes toward the LGBT population. It was found that the Brazilian psychology must adhere to a comprehensive view of gender diversity, that the prevalence of HIV in trans women is high and associated with sex work, that there are barriers in the healthcare access and that prejudice among health professionals is high, but, interventions to reduce it are effective. We point to guidelines for psychology to reduce the vulnerability of trans population.
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Transmidiação, linguagem, discurso e experiência de criação de universo narrativo: o ex-pectador e as cenas estendidas do site da telenovela Passione / Trans media, language, discourse and creation experience of narrative universe: the ex-pectator and the extented scenes of telenovela PassioneLemos, Ligia Maria Prezia 12 December 2012 (has links)
O presente estudo tem o objetivo de lançar um olhar crítico e documental sobre experimentações surgidas na ficção televisiva brasileira com a introdução de plataformas tecnológicas que possibilitaram a difusão do conteúdo em outras telas. Para isso, investiga as cenas estendidas e publicadas como exclusivas no site da telenovela Passione, da Rede Globo, exibida de maio de 2010 a janeiro de 2011. Essas cenas representaram um \"ensaio\" de criação de linguagem que abre questionamentos significativos no campo da linguagem da produção em uma época marcada pelas alterações dos papéis do emissor, do receptor e dos meios de comunicação. Com esse objetivo, o trabalho propõe uma análise daquelas cenas da telenovela que, produzidas exclusivamente para o site, estendem a narrativa da TV para a internet. Partindo de uma perspectiva interdisciplinar, indica discussões possíveis acerca da linguagem complexa e da expressão artística e, dessa forma, o trabalho busca examinar o objeto por meio de uma série de lentes epistemológicas. A abordagem teórica do trabalho, com sustentação nos Estudos Culturais e suas ramificações na América Latina, visa aproximar-se do tema da transmidiação, atravessando questões relacionadas ao pensamento complexo e a cultura das redes. Portanto, tem um papel de revisão ao mesmo tempo em que coloca propostas de modelos de análise em um momento histórico em que os existentes se mostram muitas vezes insuficientes para dar conta da complexidade das práticas sociais envolvidas na Comunicação. Uma das hipóteses que trazemos à luz é que o conceito de autoria encontra-se ampliado pela interatividade, pelos sistemas colaborativos e interativos e pela produção dos fãs; o que leva o polo da produção a pesquisar e experimentar diferentes possibilidades criativas. Como procedimento metodológico, utilizamos o estudo de caso das cenas estendidas da telenovela Passione e, em paralelo, consideramos a linguagem de outros transbordamentos para múltiplas plataformas, realizando uma abordagem qualitativa documental. Dessa forma, o processo metodológico se desdobrou de maneira simultânea e complementar: (a) no acompanhamento da telenovela pela TV analógica e digital; (b) no acompanhamento do site antes, durante e após a exibição da telenovela, com interatividade pessoal; (c) no acompanhamento de outras plataformas; (d) no acompanhamento das cenas estendidas. O corpus da pesquisa é composto por 211 cenas estendidas de Passione que estavam no ar, no site, na Aba Personagens, no mês de junho de 2011 e que foram organizadas e transcritas para análise. Colocado no papel de confidente e com forte expectativa de interagir, o espectador, olhado pelas lentes teóricas e metodológicas de nossa pesquisa, transforma-se em ex-pectador. O ex-pectador é aquele que está em rede, está com. / The following study objective is to create a critical view about one of the instances of experimentation on brazilian TV fiction with the introduction of technologic platforms which enabled the broadcast of content to other screens. To reach that objective, this paper investigates the extended scenes published as exclusive content at Rede Globo\'s telenovela Passione website, available from May 2010 through January 2011. These scenes represented an essay of language creation that opens significant questioning in the field of production language in an age marked by changes in the role of the broadcaster, changes on the receiver end of the spectrum and in communication methods. With this objective, this study proposes to review these telenovela scenes produced exclusively to the website, expanding the story from the television to the internet. Following distinct visions, it indicates possible discussions about the complex language and artistic expression and, in this way, the study proposes to examine the same object through a series of epistemological lenses. The theoretical structure of this essay has, therefore, a role of revision, exposing proposals of review models in a historic moment in which the existing ones can no longer explain the complexity of communications. One hypothesis that we bring to light is that the concept of authorship finds itself amplified by interactivity, by collaborative and interactive systems and by fan creation; which leads to the point of production to research and experiment different creative possibilities. As a methodological procedure, we use the study of subject of extended scenes from telenovela Passione and, in the same time, consider the language of other creations to multiple platforms, doing a qualitative and documental approach. In that way, the methodological process unfolded in a simultaneous and complementary manner: (a) following up the telenovela by analogic and digital television; (b) following up the website before, during and after the presentation of the telenovela with personal interactivity; (c) following up other platforms; (d) following up the extended scenes. The research body is comprised of 211 extended scenes of Passione that were available on its website in the \'personagens\' tab in July 2011. Those of which were organized and transcripted for analysis. In the role of confidant and with great expectations to interact, the spectator, looking through the theoretical and methodological lenses of our research, transforms into an ex-pectador. The ex-pectador is the one who is in ring.
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Cell biology and role of TAS3-derived trans-acting small interfering RNA during Arabidopsis thaliana development / Biologie cellulaire et rôle au cours du développement d'Arabidopsis thaliana des trans-acting small interfering RNA produits par TAS3Jouannet, Virginie 12 January 2012 (has links)
L'interférence ARN est un ensemble de mécanismes de régulation essentiel pour denombreux processus au cours du développement. Ces mécanismes sont caractérisés par lʼinhibition séquence-spécifique de lʼexpression de gènes via lʼaction de petites molécules dʼARN. Parmi les différentes voies de l'interférence ARN, la voie des trans-acting siRNAs dérivés du précurseurTAS3,qui combine des caractéristiques des voies des miRNAs et siRNAs, est spécifique des plantes et en contrôle divers aspects essentiels du développement. Dans cette voie, AGO7, un membre de la famille des protéines ARGONAUTE, interagit spécifiquement avec miR390 pour cibler et cliver le transcrit TAS3 amorçant ainsi la production de tasiARFs par lʼaction de SGS3, RDR6 et DCL4. Cette voie est conservée chez toutes les plantes terrestres. Par leur activité de répression sur des membres des facteurs de réponse à l'auxine ARF2, ARF3 et ARF4, les tasiARFS contrôlent la transition de phase et la régionalisation des feuilles. Notre laboratoire et dʼautres ont montré que TAS3 était également exprimé dans la racine dʼArabidopsis, posant la question du rôle joué par la voie TAS3dans le développement des racines. Nous avons établi que la voie TAS3, par lʼaction des tasiARFs, joue un rôle essentiel dans le contrôle de la croissance des racines latérales. Nous avons démontré que la voie TAS3 agit en aval de lʼauxine pour maintenir la correcte zone et abondance des facteurs de réponse à l'auxine, ARF2, ARF3 et ARF4. De plus nous avons élucidé un ensemble complexe de rétroactions de ces ARFs sur lʼexpression de miR390. Bien que les mécanismes de la voie TAS3 ont été identifié par divers screen génétiques, notre connaissance de lʼorganisation subcellulaire de cette voie reste essentiellement méconnue. Pour cette raison, nous avons choisi dʼétudier la localisation subcellulaire de la voie TAS3, en nous focalisant sur AGO7 qui en constitue un composant spécifique. Nous avons montré que AGO7, RDR6 et SGS3 sʼaccumulent dans des focicytoplasmiques spécifiques, les siRNA bodies. Nous avons observé une colocalisation entre cessiRNA bodies et des marqueurs des stress granules ainsi qu'une protéine virale associée aux membranes. Finalement nous avons démontré lʼimportance de la localisation cytoplasmique dʼAGO7pour la biogenèse des tasiARFs. Notre travail a permis de mieux comprendre les mécanismes de lʼaction de la voie TAS3 au cours du développement dʼArabidopsis. / RNA silencing is a regulatory mechanism essential for many processes during development. This mechanism is characterized by the sequence-specific inhibition of gene expression by small RNA molecules. Among the several pathways of RNA silencing, the TAS3 trans-acting small interfering RNA (ta-siRNA) pathway, which combines features of both micro (mi)RNA and siRNA pathways, is unique to plants and controls several key aspects of plant development. In this pathwayAGO7, a member of the ARGONAUTE family of RNAse, interacts specifically with miR390 to target and cut the TAS3 transcript, priming it for production of tasiARFs by SGS3, RDR6 and DCL4 action. This pathway is conserved across all land plants. By their repressing activity on Auxin Response Factors members, ARF2, ARF3 and ARF4, the tasiARFs control phase change and leaf patterning. Our lab and others have shown that TAS3 is also expressed in the root of Arabidopsis, raising the question of the role played by the TAS3 pathway in root development. We have shown that theTAS3 pathway, through the tasiARFs action, plays an essential role in the control of lateral rootgrowth. We have demonstrated that the TAS3 pathway acts downstream of auxin, to maintain the proper zonation and abundance of the Auxin Response Factors ARF2, ARF3 and ARF4. In addition,we unravelled a complex set of feedbacks of these ARFs on miR390 expression. Although the mechanisms of TAS3 processing have been identified through various genetic screens our knowledge of the subcellular organization of this pathway remains essentially unknown. For this reason we have chosen to study the subcellular localization of the TAS3 pathway, and focused on AGO7 which represents a specific element of this pathway. We have shown that AGO7, RDR6 and SGS3 accumulate in cytoplasmic foci, dubbed siRNA bodies. We have observed colocalization between these siRNA bodies and markers of the stress granules and a membrane-associated viral protein. Finally we have demonstrated the functional relevance of the cytoplasmic localization of AGO7 for the biogenesis of tasiARFs. Our work has led to a better understanding of the mechanisms underlying the action the TAS3 pathway during the development of Arabidopsis.
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Avalia??o de ?cidos graxos trans em minibolos comercializados na cidade do Rio de Janeiro ap?s a implementa??o da RDC 360 / Trans fatty acids in minibolos marketed in the city of Rio de Janeiro - RDC 360RODRIGUES, Felipe Reis 20 July 2012 (has links)
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Previous issue date: 2012-07-20 / CAPES / In Brazil on December 23, 2003 the National Agency of Sanitary Surveillance - ANVISA has published the resolution number 360 (360 RDC). The purpose of this resolution was to repeal the laws related to nutrition labeling of packaged foods ready for consumption (DRC 39 and 40). The legislation of 2003 had the requirement on the labeling of food content of trans fatty acids, as well as specific characteristics of the information contained therein. Currently, epidemiological studies have be associated the consumption of trans fats to the risk of developing cardiovascular and chronic degenerative diseases. In addition, health professionals report that the children have shown high rates of obesity, a situation directly related to excessive consumption of manufactured products. In order to ensure the maintenance and promotion of health, the accuracy of food labels sold in Brazil, mainly in relation to lipid content present in them should be more effectively monitor. This work aimed to make a critical analysis of the nutritional labeling of ?minibolos? sold in the city of Rio de Janeiro, relating lipid profile and content of trans fatty acids and their claim presented. The methodology used for derivatization of fatty acids is characterized by the extraction transesterification. It consists of an acidic or basic catalysis, where there is a double exchange of glycerides of esters of fatty acids. The method described by Huang (2006) for methylation of fatty acids was subjected to the validation process to ensure the accuracy of the results. The determination and quantification of fatty acids were performed by gas chromatography (GC-FID) using fused silica capillary column CP-Sil 88 (100 mx 0.25 mm), at the Analytical Laboratory of Food and Beverage - LAAB. We analyzed the products containing the information to be free of trans fatty acids to quantify the actual levels of these products in order to ascertain whether the labels were described in reliable information. From the results, the obligation to inform in the labels quantities of trans fatty acids was sufficient to make available to brazilian consumers which foods are free of trans fatty acids and which still have trans fatty acids in the food industry. There were no trans fatty acids in the composition of the samples, what means that is a real assertion to be exempt from the same type of fatty acid. / No Brasil no dia 23 de dezembro de 2003 a Agencia Nacional de Vigil?ncia Sanit?ria ? ANVISA publicou a resolu??o de n?mero 360 (RDC 360). O objetivo desta resolu??o era revogar as legisla??es relacionadas a rotulagem nutricional de alimentos embalados prontos para consumo (RDC 39 e 40). A legisla??o de 2003 teve como principal caracter?stica a exig?ncia de se constar no r?tulo dos alimentos o teor de ?cidos graxos trans, al?m de caracter?sticas especificas das informa??es contidas no mesmo. Atualmente, estudos epidemiol?gicos t?m associado o consumo de gorduras trans ao risco do desenvolvimento de doen?as cardiovasculares e cr?nico-degenerativas. Al?m disso, profissionais da ?rea de sa?de relatam que a popula??o infantil tem apresentado ?ndices elevados de obesidade, situa??o diretamente relacionada ao consumo excessivo de produtos industrializados. Com o intuito de zelar pela manuten??o e promo??o da sa?de da popula??o, deve-se fiscalizar de forma mais efetiva a veracidade dos r?tulos dos alimentos comercializados no Brasil, principalmente em rela??o aos teores lip?dicos presentes nos mesmos. O presente trabalho teve por objetivos fazer uma an?lise cr?tica da rotulagem nutricional de minibolos comercializados em estabelecimentos varejistas na cidade do Rio de Janeiro, relacionando o perfil lip?dico e o teor de ?cidos graxos trans e sua alega??o apresentada. A metodologia empregada para a derivatiza??o dos ?cidos graxos ? caracterizada pela transesterifica??o. Ela consiste em uma cat?lise ?cida ou b?sica, onde h? uma dupla troca de acilglicer?is em ?steres de ?cidos graxos. O m?todo descrito por Huang (2006) para metila??o dos ?cidos graxos foi submetido ao processo de valida??o para assegurar a veracidade dos resultados obtidos. A determina??o e quantifica??o dos ?cidos graxos foram realizadas por cromatografia gasosa (CG-FID), utilizando coluna capilar de s?lica fundida CP-Sil 88 (100 m x 0.25 mm), do Laborat?rio Anal?tico de Alimentos e Bebidas ? LAAB. Foram analisados os produtos que cont?m a informa??o de serem isentos de ?cidos graxos trans para quantificar os teores reais destes produtos, visando averiguar se o descrito nos r?tulos eram informa??es fidedignas. A partir dos resultados, verificou-se em que medida a obrigatoriedade de informar nos r?tulos as quantidades de AG trans foi suficiente para tornar dispon?veis aos consumidores brasileiros quais os alimentos que s?o livres de ?cidos graxos trans e quais ainda possuem ?cidos graxos trans na ind?stria aliment?cia no Brasil. N?o foram encontrados AG trans na composi??o das amostras analisadas, sendo real a alega??o das mesmas serem isentas desse tipo de ?cido graxo.
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Síntese e avaliação biológica de glycoclusters com potencial aplicação para o tratamento de diabetes e doença de Chagas / Synthesis and biological evaluation of glycoclusters with potential applications in diabetes and Chagas diseaseFiguerêdo, Andreza da Silva 02 April 2018 (has links)
As funções abrangentes e complexas de carboidratos nos sistemas biológicos oferecem muitas possibilidades para explorar essas estruturas no desenvolvimento de estratégias terapêuticas. Como consequência de sua estrutura e função, algumas glicosidases e glicosiltransferases envolvidas em patologias significativas como diabetes e doença de Chagas são alvos interessantes na busca por inibidores enzimáticos baseados em carboidratos. Assim, o conhecimento de características estruturais e mecanismo de ação de ?- e ?-glucosidases e trans-sialidases e as sólidas evidências de que glicosidases são sensíveis a efeito de multivalência sustentaram o planejamento de glycoclusters potencialmente inibidores dessas enzimas contendo três, quatro ou seis unidades correlatas aos seus substratos naturais (glicose e galactose/ácido siálico). Adicionalmente foram propostos glycoclusters baseados na estrutura do glicoaminoácido ?-GalNAc-O-Thr. Empregando reações de cicloadição CuAAC, treze dos dezesseis glycoclusters tetra- e hexavalentes inicialmente propostos foram obtidos em bons rendimentos, sendo 8 derivados de glicose, 4 de galactose e o derivado tetravalente de ácido siálico 7. Dez desses compostos são inéditos na literatura. Com a finalidade de gerar diversidade estrutural o derivado trivalente 29 foi preparado e permitiu o acoplamento de um imino-açúcar D-gluco ou L-gulo DNJ a estruturas trivalentes de glicose. A mesma estratégia levou à obtenção do glycocluster 85, contendo unidades de galactose e um resíduo de ácido siálico. Ensaios de cinética em ?-glucosidases de arroz e Saccharomyces cerevisiae e ?-glucosidase de amêndoas com os glycoclusters derivados de glicose 1-4, 9-12 e 63-66 mostraram atividade interessante apenas para os compostos mistos, evidenciando a importância do imino-açúcar para a interação com essas enzimas. No que diz respeito aos derivados multivalentes de galactose e/ou ácido siálico 5-7, 13, 14 e 85, inibição expressiva da enzima TcTS foi alcançada pelo derivado 7 (IC50 450 ?M). Ensaios de atividade tripanocida, bloqueio de invasão e citotoxicidade sobre fibroblastos de mamífero não-infectados cultivados in vitro evidenciaram atividade de todos esses compostos contra a forma amastigota e bloqueio de invasão celular por T. cruzi (diminuindo a infecção em concentrações de até 25?M). / The comprehensive and elaborate functions of carbohydrates in biological systems offer countless possibilities to apply these structures in the development of therapeutic strategies. Because of their structure and function, some glycosidases and glycosyltransferases involved in pathological conditions such as diabetes and Chagas disease are interesting targets in the search for carbohydrate-based enzyme inhibitors. Thus, the knowledge of structural features and the mechanism of action of ?- and ?-glucosidases and trans-sialidases, combined with strong evidences that glycosidases are sensitive to multivalent effect, have supported the design of substrate-based glycoclusters with potential glycosidases inhibitory properties. In addition, glycoclusters based on the structure of the ?-GalNAc-O-Thr glycoamino acid have been planned. Using CuAAC cycloaddition reactions, thirteen of the sixteen tetra- and hexavalent glycoclusters were obtained in good yields, being 8 glucose derivatives, 4 galactose, and the tetravalent sialic acid derivative 7. Ten of these compounds are unpublished. In order to generate structural diversity, the trivalent block 29 was prepared and allowed the coupling of trivalent glucose clusters to iminosugars D-gluco or L-gulo DNJ isomers. The same strategy afforded glycocluster 85, containing galactose units and a sialic acid residue. Kinetic assays in ? and ?-glucosidases with the glucose-derived glycoclusters 1-4, 9-12 and 63-66 showed interesting activity only for the heteroclusters compounds, evidencing the relevance of iminosugars for the interaction with these enzymes. Regarding galactose and/or sialic acid cluster 5-7, 13, 14 and 85, significant inhibition of the TcTS enzyme was achieved by derivative 7 (IC50 450 ?M). In vitro assays for trypanocidal activity and cytotoxicity showed good results for of all these compounds. They appear to block host cell invasion by T. cruzi (reducing infection index in concentrations up to 25?M).
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Effet protecteur des produits laitiers sur le risque de syndrome métabolique : quel est l'impact nutritionnel de l'acide trans-palmitoléique (C16∶1 n-7 trans) ? / Consumption of dairy products and lower risk of metabolic syndrome : a nutritional role for trans-palmitoleic acid (trans-C16∶1 n-7) ?Guillocheau, Etienne 01 July 2019 (has links)
L’acide trans-palmitoléique (C16:1 n-7 trans, TPA) est considéré comme un marqueur de la consommation de produits laitiers. D’une part, la consommation de produits laitiers est associée à un moindre risque de syndrome métabolique. D’autre part, de forts taux circulants de TPA sont épidémiologiquement associés à un moindre risque de diabète de type 2. Les bénéfices de la consommation de produits laitiers peuvent-ils en partie être expliqués par le TPA ? À ce jour cependant, aucune étude de supplémentation en TPA n’existe pour confirmer ces associations, et les doutes sur l’origine formelle du TPA ne sont pas levés. Dans ce travail, nous montrons (1) que le TPA provient de la rétro-conversion endogène de l’acide trans vaccénique (C18:1 n-7 trans, TVA) alimentaire chez l’Homme, (2) que le TPA et le TVA sont apportés exclusivement par la matière grasse de ruminants (lait et viande de ruminants) en France, (3) la possibilité d’obtenir du TPA pur en quantités suffisantes pour mener des études nutritionnelles et (4) que la supplémentation en TPA pur chez la souris dans un contexte de mise en place de syndrome métabolique empêche la mise en place de certaines dysfonctions métaboliques. Dans l’ensemble, ces résultats montrent que le TPA, acide gras spécifique de la matière grasse laitière, peut expliquer en partie l’association épidémiologique entre consommation élevée de produits laitiers et moindre risque de syndrome métabolique. / Trans-palmitoleic acid (trans-C16:1 n-7, TPA) is usually considered as a biomarker of dairy fat consumption. On the one hand, dairy product consumption is associated with lower risk of metabolic syndrome. On the other hand, high circulating levels of TPA in humans are epidemiologically associated with lower risk of type 2 diabetes. Could benefits of dairy products consumption rely in part on TPA? So far, there is no nutritional study involving TPA to confirm such observational associations, and doubts remain as regards to the formal origin of TPA. In this work, we demonstrate (1) that TPA arises from the endogenous retro-conversion of dietary trans-vaccenic acid (trans-C18:1 n-7, TVA) in humans, (2) that both TPA and TVA intakes are exclusively ensured by ruminant products (milk and meat) consumption, (3) the ability to get pure TPA in enough amounts to carry out reliable nutritional studies and (4) that pure TPA supplementation on mice fed an obesogenic diet prevents from several metabolic dysfunctions. Taken together, our results demonstrate that the dairy fatty acid TPA may explain part of the epidemiological association between high consumption of dairy products and lower risk of metabolic syndrome.
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Molecular Dynamics Simulations Towards The Understanding of the Cis-Trans Isomerization of Proline As A Conformational Switch For The Regulation of Biological ProcessesVelazquez, Hector 10 May 2014 (has links)
Pin1 is an enzyme central to cell signaling pathways because it catalyzes the cis–trans isomerization of the peptide ω-bond in phosphorylated serine/threonine-proline motifs in many proteins. This regulatory function makes Pin1 a drug target in the treatment of various diseases. The effects of phosphorylation on Pin1 substrates and the basis for Pin1 recognition are not well understood. The conformational consequences of phosphorylation on Pin1 substrate analogues and the mechanism of recognition by the catalytic domain of Pin1 were determined using molecular dynamics simulations. Phosphorylation perturbs the backbone conformational space of Pin1 substrate analogues. It is also shown that Pin1 recognizes specific conformations of its substrate by conformational selection. Dynamical correlated motions in the free Pin1 enzyme are present in the enzyme of the enzyme–substrate complex when the substrate is in the transition state configuration. This suggests that these motions play a significant role during catalysis. These results provide a detailed mechanistic understanding of Pin1 substrate recognition that can be exploited for drug design purposes and further our understanding of the subtleties of post-translational phosphorylation and cis–trans isomerization.
Results from accelerated molecular dynamics simulations indicate that catalysis occurs along a restricted path of the backbone configuration of the substrate, selecting specific subpopulations of the conformational space of the substrate in the active site of Pin1. The simulations show that the enzyme–substrate interactions are coupled to the state of the prolyl peptide bond during catalysis. The transition-state configuration of the substrate binds better than the cis and trans states to the catalytic domain of Pin1. This suggests that Pin1 catalyzes its substrate by noncovalently stabilizing the transition state. These results suggest an atomistic detail understanding of the catalytic mechanism of Pin1 that is necessary for the design of novel inhibitors and the treatment of several diseases. Additionally, a set of constant force biased molecular dynamics simulations are presented to explore the kinetic properties of a Pin1 substrate and its unphosphorylated analogue. The simulations indicate that the phosphorylated Pin1 substrate isomerizes slower than the unphosphorylated analogue. This is due to the lower diffusion constant for the phosphorylated Pin1 substrate.
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Determining the Judicial Juristiction in the Transnational CyberspaceRaut, Bimal Kumar January 2004 (has links)
This thesis analyses the traditional notion of jurisdiction in the light of Internet based activities which are inherently decentralised and ubiquitous. It is clear that the unique nature of the Internet has undermined the very foundation of the traditional notion of jurisdiction and the territorially based concepts of law and their application. Which court should hear disputes arising out of Internet activities? On what grounds may a court assert or decline the jurisdiction? These are perplexing questions currently facing courts worldwide because of the trans-national nature of the Internet by which people can transcend borders readily and rapidly. One simple and straightforward factor confronting lawmakers is that while most laws have a territorial nexus, the Internet defies the notion of territoriality. Traditionally, judicial jurisdiction has been exercised on a number of bases, such as where the defendant resides, whether the defendant is present within the forum and whether the defendant has property in the forum or not. These elements have been made largely irrelevant by the Internet. The Internet does not respect traditional boundaries and territories and it can even enable people to cross borders without any physical mobility. For instance, people are able to interact and even do business without revealing their identity. In the absence of any definite international law on Internet jurisdiction, how have the courts responded to this challenge? This thesis has examined the recent case law in Australia, United States of America and France. In examining the case authorities, the only conclusion that can be reached is that current court approaches are unworkable. This thesis has also examined some international proposals on the matter and found them to be deficient. Now, the dilemma before us is this: on the one hand, the present court approaches on Internet jurisdiction are unworkable. On the other hand, there is no clear international guidance to govern the jurisdictional issue. I believe this book makes a small contribution towards this perplexing question by proposing a new transnational principle which could be achieved through a "trans-national judicial dialogue". Trans-national judicial dialogue can play a significant role in the creation, recognition, and enforcement of global norms. There are a number of benefits to be gained if this approach is adopted in Internet jurisdiction cases. Ideally, trans-national judicial dialogue would reduce the conflicts among courts and foster a consensual approach, thus providing a stable and predictable paradigm for the crucial issue of jurisdiction. Moreover, the parties involved in a case would be prevented from forum shopping in search of a forum with a greater likelihood of a favourable decision. Also, courts would not be able to decline jurisdiction merely because of foreign elements involved. This may be the most appropriate global approach which is urgently required to address an increasingly global problem.
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