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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

Expressão da glicoproteína recombinante do vírus rábico em sistemas Drosophila melanogaster (S2) e Semliki Forest Virus (SFV). / Rabies virus glycoprotein expression in Drosophila melanogaster (S2) and Semliki Forest Virus (SFV) systems.

Astray, Renato Mancini 18 September 2009 (has links)
A glicoproteína do vírus rábico (RVGP) é o antígeno capaz de induzir a formação de anticorpos neutralizantes e a resposta imune protetora contra a infecção pelo vírus rábico. Estudamos as cinéticas de expressão da RVGP e de seu RNA mensageiro (RVGPmRNA) em dois sistemas distintos de expressão recombinante: células de Drosophila melanogaster (S2) e células BHK-21 infectadas com vírus Semliki Forest Virus (SFV). Para isso, fizemos um trabalho de padronização do tratamento de amostras de cultivos celulares, adequando-as a um teste de ELISA para dosagem da RVGP e estabelecemos um método de RT-PCR quantitativa (qRT-PCR) para a dosagem do RVGPmRNA. Desenvolvemos também um novo método de titulação de partículas SFV por qRT-PCR, aplicável a praticamente qualquer construção de SFV recombinante. Em ensaios preliminares, as preparações de RVGP recombinante utilizadas para a imunização de camundongos foram capazes de induzir a formação de anticorpos neutralizantes e de conferir um bom grau de proteção ao teste de desafio intracerebral com vírus rábico. / The rabies virus glycoprotein is the major antigen able to induce a neutralizing antibody response and survival after challenge against rabies virus infection. We have studied the kinetic expression of RVGP and its messenger RNA (RVGPmRNA) in two different recombinant expression systems: stably transfected Drosophila melanogaster cells (rS2) and BHK-21 cells infected with Semliki Forest Virus carrying RVGP genetic information (SFV-RVGP). We have done a work of standardization of the cell culture samples treatment prior to RVGP quantification by ELISA, and we have developed and standardized a quantitative RT-PCR (qRT-PCR) to quantify the RVGPmRNA. We have also developed a new method of SFV particles titration by qRT-PCR, which is applicable to other constructions of recombinant SFV. We utilized the RVGP expressed by rS2 and SFV-RVGP systems on preliminary in vivo assays. The RVGP samples used to mice immunization were able to induce neutralizing antibodies and to lead to a nice level of protection against the intracerabral rabies virus challenge.
342

Uso de bioindicador de efeito endócrino e validação do método para determinação de hormônios na água da Represa Municipal de São José do Rio Preto, SP / Use of the endocrine bioindicator efect and method validation for determination homones in water at reservoir São José do Rio Preto city, SP

Cordeiro, Daniela 10 December 2009 (has links)
Dentre os vários xenobióticos que as atividades humanas têm produzido nas últimas décadas, os desreguladores endócrinos (EDs), incluindo os hormônios, vêm chamando a atenção de pesquisadores devido aos efeitos que eles causam em animais. Esses efeitos podem resultar em características hermafroditas nos peixes e em anfíbios, inibição do crescimento testicular, inibição da espermatogênese, decrescimento da capacidade de fertilização dos ovos e alteração no comportamento reprodutivo dos seres vivos. Concentrações de apenas 10 ng L-1 de hormônio no meio aquático já são capazes de causar efeito endócrino nos organismos. Neste estudo determinou-se o hormônio natural 17β-estradiol e os hormônios sintéticos levonorgestrel e 17α-etinilestradiol na água da Represa Municipal de São José do Rio Preto (SP). A primeira etapa deste estudo foi a validação dos métodos segundo a Resolução-RE 899 da ANVISA. Os limites de detecção, de quantificação e inferior de quantificação do método para a determinação do 17α-etinilestradiol foram, respectivamente, 25, 100 e 100 ng L-1. A linearidade, desvio-padrão relativo, exatidão e recuperação média para o 17α-etinilestradiol foram, respectivamente, R de 0,98, 3,23%, 100,53% e 89,95%. Os limites de detecção, de quantificação e inferior de quantificação do método para a determinação do 17β-estradiol foram, respectivamente, de 100, 150 e 150 ng L-1. A linearidade, desvio-padrão relativo, exatidão e recuperação média do 17β-estradiol foram, respectivamente, R de 0,99, 3,43%, 106,16% e 89,05%. Para o levonorgestrel, os limites de detecção, de quantificação e inferior de quantificação foram, respectivamente, 50, 150 e 150 ng L-1. A linearidade, desvio-padrão relativo, exatidão e recuperação média do método para a determinação do levonorgestrel foi respectivamente, R de 0,98, 3,48%, 105,15% e 86,45%. Na segunda etapa desta pesquisa analisaram-se amostras de água coletadas na Represa Municipal de São José do Rio Preto (SP) quanto à presença de hormônios. Como método de extração dos hormônios, usou-se a SPE e, como técnica analítica HPLC/FLU/DAD. Os resultados não indicaram a presença dos hormônios estudados até o limite de detecção do método empregado. Foi feita também a análise de vitelogenina (VTG) em plasma sanguíneo de peixes das espécies Geophagus brasiliensis (cará), Satanoperca pappaterra (zoiúdo) e Tilapia rendalli (tilápia rendali) capturados na referida represa. Observou-se que os peixes machos continham concentração de VTG na faixa de 152,4 a 2.841,8 ng mL-1. Isto indica que há substâncias de efeito endócrino na água da represa, mas não se pode afirmar que sejam os hormônios estudados. / Among the several xenobiotics that human activities have produced in the last decades, endocrine disruptors (EDs), including hormones, have been drawing the attention of researches due to the effects they can cause in animals. Those effects may result in hermaphrodite characteristics in fishes and amphibians, testicular growth inhibition, spermatogenesis inhibition, eggs fertilization capacity decrease, and changes in the reproductive behavior of living beings. Concentrations of only 10 ng L-1 of hormones in the aquatic medium are capable of causing endocrine effects in organisms. In this study, the natural hormone 17β-estradiol and the synthetic ones levonorgestrel and 17α-ethinylestradiol were determined in the waters of the São José do Rio Preto (SP) dam. The first step of this study was the validation of the methods according to ANVISA\'s Resolution 899. The detection, quantification, and lower quantification limits of the method for determining 17α-ethinylestradiol were, respectively, 25, 100, and 100 ng L-1. The linearity, relative standard deviation, accuracy, and average recovery of the method for determining 17α-ethinylestradiol were, respectively, R equal to 0.98, 3.23%, 100.53%, and 89.95%. The detection, quantification, and lower quantification limits of the method for determining 17β-estradiol were, respectively, 100, 150, and 150 ng L-1. The linearity, relative standard deviation, accuracy, and average recovery of the method for determining 17β-estradiol were, respectively, R equal to 0.99, 3.43%, 106.16%, and 89.05%. For levonorgestrel, the detection, quantification, and lower quantification limits of the method were, respectively, 50, 150, and 150 ng L-1. The linearity, relative standard deviation, accuracy, and average recovery of the method for determining levonorgestrel were, respectively, R equal to 0.98, 3.48%, 105.15%, and 86.45%. In the second step of this research, samples collected in the São José do Rio Preto (SP) dam were analyzed regarding the presence of hormones. For extracting the hormones, SPE cartridges were used followed by HPLC/FLU/DAD. The results indicated the absence of the studied hormones down to the detection limits of the methods employed. Vitellogenin (VTG) analyses were performed in the blood plasma of fishes captured in the beforementioned dam, of the species Geophagus brasiliensis (pearl cichlid or pearl eartheater), Satanoperca pappaterra (Pantanal eartheater or Paraguay River eartheater), and Tilapia rendalli (redbreast tilapia). It was observed that male fishes had VTG concentrations between 152.4 and 2,841.8 ng mL-1. That indicates that there are substances with endocrine effect in the dam water, although one cannot say the studied hormones are among them.
343

Estudo soroepidemiológico da infecção por paramixovírus ofídico em serpentes mantidas em cativeiro

Oliveira, Cristiano Correa January 2019 (has links)
Orientador: Lucilene Delazari Santos / Resumo: O veneno de serpente tem sido utilizado para diversas finalidades terapêuticas; portanto, desde o início do século XX, a criação de serpentes em cativeiro tornou-se uma atividade cada vez mais relevante. Os principais motivos da existência e permanência destes cativeiros se atribuem à produção dos soros antiofídicos, e o uso de seus venenos e seus componentes isolados com potenciais aplicações à saúde animal e humana. Porém, a vida em cativeiro pode resultar na síndrome da má adaptação, a qual o animal sob estresse desenvolve inapetência e, consequentemente há o acometimento da imunidade, podendo desenvolver infecções por micro-organismos como fungos, bactérias e vírus. Desta forma, o controle e prevenção de infecções em serpentes mantidas em cativeiro tornaram-se assuntos muito importantes. Dentre as doenças infecciosas virais, têm-se a infecção pelo Paramixovírus ofídico, atualmente, denominado Ferlavirus reptiliano. Este vírus é altamente devastador em serpentes, pois atua no sistema nervoso central e respiratório, podendo levar à morte e/ou morbidade na fase aguda da doença, sendo que na fase crônica, o animal pode atuar como reservatório do vírus, e disseminar a doença no plantel. Atualmente, não há tratamento específico nem vacinas disponíveis para esta virose. Porém, testes sorológicos estão emergindo para a detecção de anticorpos. Dentre estes testes, encontram-se o ensaio de Inibição de Hemaglutinação (HI) e o ensaio de ELISA de Bloqueio de Fase Líquida (BFL-ELISA), ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Snake venom has been used for several therapeutic purposes. Therefore, breeding snakes in captivity has become an increasingly relevant activity since early20th century. The main reasons for the existence and permanence of these captivities are the production of snake antivenom and the use of venom and its isolate compounds with potential applications in human and animal health. However, living in captivity may result in the maladaptation syndrome, in which the animal under stress develops inappetence and, consequently, a decrease in immunity, becoming more likely to develop infections caused by microorganisms as fungi, bacteria and viruses. Thus, the control and prevention of infections in snakes kept in captivity became very important subjects. The infection by the ophidian paramyxovirus named reptilian ferlavirus is among the viral infectious diseases. This virus is highly devastating in snakes because its action in central and respiratory nervous system and may lead to death and/or morbidity in the acute stage of the disease, consideringthat the animal may act as a reservoir of the virus in the chronic stage and spread the disease in the breeding stock. Nowadays, there isn’t a specific treatment or vaccines available for strike this viral infection, however, serological tests are emerging for antibodies detection. Hemagglutination Inhibition (HI) and Liquid Phase Blocking ELISA (LPB-ELISA) are among these tests, which differs from each other in sensitivity and analytical ... (Complete abstract click electronic access below) / Mestre
344

Development of immunoassays for diagnosis of type 1 diabetes / Développement de dosages d’auto-anticorps pour le diagnostic du diabète de type 1

Kikkas, Ingrid 06 October 2014 (has links)
Le diabète de type 1 est une maladie auto-immune caractérisée par la destruction des cellules bêta des îlots de Langerhans du pancréas. Au cours de ce processus auto-immun, des auto-anticorps sont produits contre plusieurs antigènes des cellules bêta, par exemple l'insuline, l'acide glutamique décarboxylase (GAD65), la protéine tyrosine phosphatase (IA-2) et le transporteur de zinc (ZnT8). Au moins un auto-anticorps contre l'un de ces antigènes est présent dans> 95% des personnes atteintes de diabète de type 1 lors de la détection de l'hyperglycémie. Ces auto-anticorps peuvent servir de marqueurs précoces de diabète de type 1, car ils peuvent être présents des années avant l'apparition de la maladie, ce qui permet un diagnostic précoce avant les manifestations cliniques. Dans le cadre de cette thèse, nous avons développé, en partenariat avec une équipe de recherche clinique, une série de tests diagnostiques originaux, basée sur la détection précoce des différents auto-anticorps d’îlots de Langerhans à partir d'échantillons de sérum humain. Ces tests de diagnostic comprennent des tests bridging ELISA pour la détection d'auto-anticorps contre l'insuline, IA-2 et GAD65, qui sont rapides, facile à utiliser et n’utilisent pas de radioactivité. De plus, un test immunochromatographique sur bandelette pour la détection des auto-anticorps contre IA-2 a été développé. Le principal avantage des tests bandelettes est sa convivialité : les résultats peuvent être obtenus en 45 min en utilisant de très petits volumes de sérums et sans l'utilisation d’appareils spécialisés. Tous ces tests développés en interne ont été validés avec des échantillons de sérum de patients atteints de diabète de type 1 et de témoins sains et leurs performances ont été comparées avec celles de tests disponibles sur le marché. En outre, nous avons développé un test multiplex pour la détection simultanée de plusieurs auto-anticorps associés au diabète de type 1, ce qui permet de gagner du temps et d’augmenter la valeur diagnostic et prédictive du test par rapport à la détection d’un seul autoanticorps. Ce test multiplex a été validé pour la détection de deux autoanticorps (IA-2A et GADA) et comparé à nos tests ELISA de IA-2A et GADA. / Type 1 diabetes is an autoimmune disease characterized by the destruction of pancreatic beta cells within the islets of Langerhans. In the course of this autoimmune process, autoantibodies are generated against several beta-cell antigens, e.g. insulin, glutamic acid decarboxylase (GAD65), tyrosine phosphatase-like protein (IA-2) and zinc transporter 8 (ZnT8). At least one autoantibody against one of these antigens is present in >95% of individuals with type 1 diabetes upon hyperglycemia detection. These autoantibodies can serve as early markers of type 1 diabetes, since they can be present years before disease onset, allowing for an early diagnosis before clinical manifestations. In the course of this thesis we have developed, in partnership with a clinical research team, a series of original diagnostic tests, based on the early detection of the different anti-Langerhans islet autoantibodies from human serum samples. These diagnostic tests include bridging ELISAs for the detection of autoantibodies to insulin, IA-2 and GAD65, which are rapid, non-radioactive and easy-to-use. Moreover, a lateral flow immunoassay (dipstick) for detection of autoantibodies to IA-2 was developed. The key advantage of lateral flow immunoassay is its user-friendly format: results can be obtained within 45 min using very small volumes of sera and without the use of any specialized apparatus. All these in-house assays were validated with diabetic and healthy human serum samples and the assay performances were compared to commercially available tests on the market. In addition, we have developed a multiplex assay for simultaneous detection of multiple diabetes-associated autoantibodies, which is time-effective and increases the diagnostic and predictive values of the assay, comparing to single autoantibody detection. This multiplex assay was validated for detection of two autoantibodies i.e. IA-2A and GADA and compared to in-house IA-2A and GADA bridging ELISAs.
345

Recherche de nouvelles réactions de couplage par criblage immuno-enzymatique / Discovery of coupling reactions using an immunoassay screening

Kolodych, Sergii 12 September 2013 (has links)
La recherche de nouvelles réactions est un des enjeux fondamentaux de la chimie organique. En dehors de l’approche classique basée sur la conception d’une réaction en s’appuyant sur les propriétés chimiques des substrats, une nouvelle approche utilisant le criblage systématique de combinaisons aléatoires de fonctions réactives a été récemment adoptée par plusieurs groupes. Cette stratégie nécessite un outil analytique permettant de cribler un très grand nombre de réactions par jour et d’identifier les meilleures combinaisons conduisant à la formation de produits intéressants. Les travaux de thèse présentés dans ce mémoire s’inscrivent dans le contexte de l’utilisation des techniques de dosages immuno-enzymatiques (ELISA) comme outil de criblage pour la recherche de nouvelles réactions de couplage. Dans un premier temps le criblage de 2688 combinaisons de fonctions réactives et de catalyseurs choisies au hasard a été effectué. Ce criblage a permit de mettre en évidence deux nouveaux couplages en présence de sels de cuivre : une réaction entre les thiourées et les phénols conduisant à la formation des isourées et une réaction entre les N-hydroxythiourées et les alcynes conduisant à la formation des thiazole-2-imines. Dans un second temps le criblage de 2816 combinaisons de fonctions sélectionnées, cette fois-ci, de façon rationnelle a été effectué. Ce criblage a visé la découverte de nouvelles cycloadditions [3+2] répondant aux critères de la chimie « click ». Ainsi l’utilisation de dosage immuno-enzymatique a été étendue à l’optimisation des nouvelles réactions découvertes ainsi qu’à l’évaluation de leurs cinétique, chimiosélectivité et biocompatibilité. Près de 3000 tests complémentaires effectuées sur les « hits » issus du criblage primaire ont ainsi permit de mettre en évidence 4 nouvelles réactions de couplage dont une nouvelle réaction « click » : la cycloaddition sydnone-alcyne catalysée au cuivre (CuSAC). Dans la dernière partie de ce manuscrit les études plus détaillées sur la réaction CuSAC ont été effectuées, notamment l’identification de la structure du produit de couplage et l’étendue du champ d’application de cette réaction. Enfin, l’aspect « click » de la réaction CuSAC a été illustré par l’application de cette réaction au marquage d’une protéine. / Discovery of new reactions is one of the fundamental goals in organic chemistry. In addition to the traditional approach to reaction discovery, consisting in designing a reaction on the basis of known chemical properties of reagents, new approaches based on the screening of random combinations of reactive functions and catalysts have been recently developed. The main prerequisite of this strategy is an analytical tool allowing screening of a big number of reactions per day and identifying combinations leading to the formation of unanticipated products. In the work presented herein a high-throughput immunoassay screening has been used for the discovery of new coupling reactions. In the first part of this work a screening of 2688 combinations of randomly chosen reactive functions and catalysts was carried out. This screening led to the discovery of two copper-promoted coupling reactions: a reaction between thioureas and phenols leading to the formation of isoureas through desulfurization; and a reaction between N-hydroxythioureas and alkynes leading to the formation of thiazole-2-imines. In the second part of the work a screening of 2816 combinations of rationally designed chemical functions and catalysts was carried out. This screening was focused on the discovery of catalytic [3+2] cycloadditions that comply with the standards of “click” chemistry. In this study, the use of immunoassay screening was extended to optimize new reactions and to evaluate their kinetics, chemoselectivity and biocompatibility. Therefore, around 3000 complementary tests were carried out on the hits, identified in the primary screening. This allowed the discovery of 3 new coupling reactions and one new “click” reaction: a copper-catalyzed sydnone-alkyne cycloaddition (CuSAC). The last part of the work was focused on detailed studies of the CuSAC reaction. Identification of the structure of the coupling product and substrate scope of this reaction was carried out. Finally, the applicability of the CuSAC reaction for bioconjugation was demonstrated by an example of protein labeling.
346

Ecologia de Culex quinquefasciatus e de Culex nigripalpus no Parque Ecológico do Tietê, São Paulo, Brasil / Ecology of Culex quinquefasciatus and Culex nigripalpus at the Parque Ecológico do Tietê, São Paulo, Brasil.

Laporta, Gabriel Zorello 19 October 2007 (has links)
Introdução - Culex quinquefasciatus é um mosquito sinantrópico que causa incômodo à população humana e é relacionado com a transmissão de nematóides ou arbovírus em áreas endêmicas, respectivamente, do litoral brasileiro e da América Central ou do Norte. Culex nigripalpus é um mosquito hemi-sinantrópico que possui a capacidade de se dispersar para as áreas antrópicas e transmitir Saint Louis Virus e Equine Encephalitis Virus, respectivamente, na América do Norte e Venezuela. Objetivo - Caracterizar o hábito alimentar de Culex nigripalpus e a densidade, a sobrevivência e o hábito alimentar de Culex quinquefasciatus no Parque Ecológico do Tietê (PET), São Paulo. Métodos - O PET é uma Área de Preservação Ambiental com animais residentes ou migratórios. As amostras de mosquitos adultos foram coletadas, mensalmente, em quatro áreas no PET, durante um ano e por meio de aspirador à bateria. O método de ELISA indireto foi empregado para a identificação do hospedeiro que é fonte alimentar ao mosquito. A densidade da população de Cx. quinquefasciatus foi estimada pelo método de marcação, soltura e recaptura na vegetação da margem de um canal no PET. Amostras de fêmeas de Cx. quinquefasciatus desse local foram dissecadas ou acompanhadas em laboratório para estimativa da taxa de sobrevivência. Resultados – A proporção de repastos sangüíneos de Cx. quinquefasciatus e de Cx. nigripalpus foi, respectivamente, 6,5 e 8,3% em humanos, 18,8 e 27,7% em cães, 7,4 e 2,3% em galinhas, 2,8 e 9,0% em ratos, 3,2 e 8,3% em múltiplos hospedeiros e 67,7 e 60,9% em hospedeiros não identificados. Human Blood Index para Cx. quinquefasciatus e Cx. nigripalpus foi, respectivamente, 0,20 e 0,17. Feeding Index entre os hospedeiros homem/cão, homem/galinha e homem/rato foi, respectivamente, 0,35, 0,63 e 2,65 para Cx. quinquefasciatus e 0,30, 2,56 e 1,05 para Cx. nigripalpus. A distribuição de repastos sangüíneos teve associação significante estatisticamente com as fêmeas de Cx. nigripalpus em estádio de Sella 2 coletadas em todas as áreas do PET. A densidade de Cx. quinquefasciatus para uma área de 2.520 m2 foi 7.262±1.537. A proporção de paridas, a duração do ciclo gonotrófico e a taxa de sobrevivência foram, respectivamente, igual a 0,48, 4,75 (CL 95% = 4,3-5,2) e 0,86, estimados para a população de Cx. quinquefasciatus. Conclusões – Cães e galinhas foram hospedeiros importantes para Cx. quinquefasciatus, enquanto que cães foram hospedeiros importantes para Cx. nigripalpus. O repasto sangüíneo é mais bem detectado pelo ELISA indireto em fêmeas no estádio de Sella 2. A sobrevivência e a densidade de Cx. quinquefasciatus indicam que essa espécie é epidemiologicamente relevante na área do PET como espécies vetora ou peste urbana. Essa espécie deve ser objetivo do programa de controle de vetores no município de São Paulo. / Introduction - Culex quinquefasciatus has high synanthropy, infest human dwellings and is vector of nematoids and arbovirus from endemic areas, respectively, in Brazilian coast and in Central or North America. Culex nigripalpus has average synanthropy and can disperse through the anthropic environment carrying Saint Louis Virus and Equine Encephalitis Virus, respectively, in North America and Venezuela. Objective - To characterize host-feeding habit of Culex nigripalpus and density, survival and host-feeding habit of Culex quinquefasciatus in the Parque Ecológico do Tietê (PET), São Paulo. Methods - The PET is an Area of Environmental Protection with resident or migratory animals. The samples of adult mosquitoes were collected, monthly, in four areas in the PET, during one year and by means of a backpack battery aspirator. An indirect ELISA technique was used for the identification of the host that is an alimentary source for the mosquito species. The density of Cx. quinquefasciatus population was estimated using the Mark, Release and Recapture method on the vegetation of the edge of a canal in the PET. Samples of females of Cx. quinquefasciatus from this place were dissected or followed in laboratory for estimating the survival rate. Results – Cx. quinquefasciatus and Cx. nigripalpus fed on human 6.5 and 8.3%, dog 18.8 and 27.7%, chicken 7.4 and 2.3%, rat 2.8 and 9.0%, multiple hosts 3.2 and 8.2% and unidentified hosts 67.9 and 60.9%, respectively. The unweighted human blood index (HBI) values were 0.20 for Cx. quinquefasciatus and 0.17 for Cx. nigripalpus populations. The feeding index values between the hosts human/dog, human/chicken and human/rat were, respectively, 0.35, 0.63 and 2.65 for Cx. quinquefasciatus and 0.30, 2.56 and 1.05 for Cx. nigripalpus. The distributions of blood-meals had statistically significant association on Sella 2 stage of the Cx. nigripalpus collected in all areas at the PET. The density of Cx. quinquefasciatus for an area of 2,520 m2 was 7,262±1,537. The proportion of parous, gonotrophic cycle length and survival rate were, respectively, equal to 0.48, 4.75 (CL 95% = 4.3-5.2) and 0.86, for Cx. quinquefasciatus population. Conclusions – Dogs and chickens are important hosts for Cx. quinquefasciatus, whereas dog is an important host for Cx. nigripalpus. The host-blood of females in Sella 2 stage increases sensibility of the indirect ELISA assay. The survivorship and the density of Cx. quinquefasciatus indicate that these species are epidemiologically relevant in the PET area as either a pest or vector species. Those species should be a goal of the vector control program of Sao Paulo municipality.
347

Caracterização molecular e avaliação da resistência ao vírus da tristeza dos citros (CTV) em plantas transgênicas de laranja \'Valência\' (Citrus sinensis L. Osbeck) / Molecular characterization and resistance evaluation to citrus tristeza virus (CTV) in transgenic plants of Valência orange (Citrus sinensis L. Osbeck)

Fabiana Rezende Muniz 02 February 2009 (has links)
No Brasil a citricultura está entre as culturas de maior importância. A produtividade dessa cultura no país ainda é considerada baixa e esse fato se deve, em parte, a diversas pragas e doenças. Dentre as doenças, tem-se a tristeza, causada pelo Citrus tristeza virus (CTV). Esse patógeno também pode estar relacionado com outra importante doença da cultura, a morte súbita dos citros (MSC). Com isso, o CTV ganhou ainda maior expressão. Uma alternativa para controlar viroses de plantas é a obtenção de plantas transgênicas resistentes a esses patógenos. Este trabalho objetivou caracterizar com análise molecular e avaliar a resistência ao CTV de plantas transgênicas de laranja Valência (Citrus sinensis L. Osbeck), contendo fragmentos do genoma do CTV, em três construções gênicas diferentes. A transgenia das plantas foi confirmada por análises de Southern blot. A transcrição do transgene foi avaliada por RT-PCR. O material foi inoculado com duas borbulhas infectadas pelo isolado Pêra- IAC, enxertadas no porta-enxerto abaixo do ponto de enxertia da copa transgênica, e pelo vetor Toxoptera citricida infectado. Após quatro semanas da inoculação, para avaliar a resistência ao vírus, brotações da copa transgênica foram submetidas ao teste de ELISA sanduíche indireto com anticorpo monoclonal contra a proteína da capa protéica do CTV. Os resultados indicaram variação na resistência à translocação do vírus nas diferentes construções transgênicas utilizadas e entre clones de uma mesma planta. Todas as linhagens transgênicas inoculadas indicaram a presença do vírus em pelo menos uma das três repetições avaliadas, quando inoculadas por enxertia. Quando inoculadas pelo vetor algumas plantas apresentaram todos os seus clones com baixos valores de absorbância, indicando uma possível resistência ao patógeno. / In Brazil, citrus is one of the most important cultures. The productivity of this culture in the country is still considered low and this fact is due to several pests and diseases that affect the crop. Among the diseases there is the tristeza, caused by Citrus tristeza virus (CTV). This pathogen can also be related with another important disease, the citrus sudden death. Therefore, CTV acquired much more significance. This work aimed to characterize with molecular analysis and to evaluate the resistance to CTV of transgenic Valência plants (Citrus sinensis L. Osbeck), containing genomic fragments of CTV, in three different transgenic constructs. The plants were confirmed as transgenic by Southern blot. The transcription of the transgene was evaluated by RT-PCR. The transgenic plants were challenged with a weak strain of CTV, CTV-IAC, by bud inoculation with two infected bubbles, and by the infected vector Toxoptera citricida. After four weeks of inoculation, the evaluation of viral replication in the transgenic seious was done by ELISA indirect sandwich with monoclonal antibody against the CTV coat protein. The results indicated variation of the resistance to the translocation of the virus between the different transgenic constructs used and between clones of the same plant. All the inoculated plants indicated the presence of the virus in, at least, one of the three evaluated clones, when inoculated by grafting. When inoculated by the vector some plants had all their clones with low values of virus, indicating a possible resistance to the pathogen.
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Utvärdering av C6-peptid-baserad serologi på cerebrospinalvätska som komplement vid diagnostik av neuroborrelios

Knaziak, Margareta January 2012 (has links)
Borrelios är den vanligaste fästingburna infektionen på norra halvklotet, och orsakas av spiroketer tillhörande Borrelia burgdorferi sensu lato-komplexet. Dessa bakterier kan spridas till flera organ och ge upphov till olika symptom i bland annat hud, nervsystem, leder och hjärta. Omkring 15 % utvecklar neurologiska symptom, så kallad neuroborrelios. Den bästa indikatorn på aktiv neuroborrelios är framförallt karakteristiska neurologiska symptom samt tecken på en inflammatorisk förändring i cerebrospinalvätskan (CSV) i kombination med lokalt producerade antikroppar mot Borrelia burgdorferi s.l. i CSV. Nuvarande metod för diagnostik av neuroborrelios är en immunokemisk metod, en ELISA (enzyme-linked immunosorbent assay) som bygger på en jämförelse av Borrelia-antikroppsnivåer i CSV och i serum genom beräkning av antikroppsindex (AI). Beräkning av AI kompenserar för en eventuell ospecifik överföring av antikroppar från serum, till följd av en skada på blod-hjärnbarriären. Det finns dock tecken på att den nuvarande analysmetoden har för låg sensitivitet med falskt negativa resultat, framförallt tidigt i infektionsförloppet. För diagnostik av andra former av borrelios än neuroborrelios används en typ av ELISA baserad på C6-peptid. C6-peptid ELISA visar god känslighet för detektion av B. burgdorferi s.l.-specifika antikroppar i serum. C6-antigenet utgör en starkt immunogen och konserverad region av bakteriens VlsE-ytprotein. Syftet med den här studien var att undersöka om detektion av antikroppar mot C6-peptid i CSV kan komplettera den nuvarande använda metoden och därmed förbättra den totala sensitiviteten för diagnostik av neuroborrelios. I studien analyserades 169 patientprover från unga personer, samt 18 oklara patientfall som tidigare bedömts negativa med den nuvarande metoden. Antikroppar mot C6-peptid detekterades hos åtta unga patienter samt två oklara patientfall. Av dessa hade åtminstone tre unga patienter sannolikt neuroborrelios. Resultat från den här studien tyder på att C6-peptid-ELISA på CSV-prover kan fungera som ett komplement till befintlig metod för diagnostik av neuroborrelios. En kombination av båda metoderna kan sannolikt ge en betydligt högre sensitivitet. Vid tolkning av resultat från C6-peptid-baserade analysmetoder på CSV ska hänsyn tas till eventuell ospecifik överföring av B. burgdorferi s.l.-specifika antikroppar genom blod-hjärnbarriären. / Lyme Borreliosis, caused by spirochetes of the Borrelia burgdorferi sensu lato-complex, is the most common tick-borne infection in the temperate regions of the northern hemisphere. The bacteria can infect many different organs, this can give rise to a variety of symptoms in skin, the nervous system, joints and heart. Approximately 15 % of the infected individuals show neurological symptoms referred to as neuroborreliosis. An active neuroborreliosis is indicated by inflammatory changes in the cerebrospinal fluid (CSF) and local synthesis of anti-Borrelia antibodies in CSF. The current method to diagnose neuroborreliosis is an enzyme-linked immunosorbent assay (ELISA) which compares levels of anti-Borrelia antibodies in CSF and serum by calculating an antibody index (AI). Calculations of AI compensate for unspecific leakage of antibodies from serum to CSF following an injury of the blood-brain barrier. The drawback of the current method is a low sensitivity with a high rate of false negative results in samples collected early during an infection. Another type of ELISA, based on the use of a C6 peptide, has earlier shown good sensitivity for detection of B. burgdorferi s.l.-specific antibodies in serum. The C6 antigen corresponds to a highly immunogenic and conserved region of the bacterial surface protein VlsE. The aim of this study was to investigate whether a detection of antibodies against the C6 peptide in CSF could improve the total sensitivity for the diagnostics of neuroborreliosis. In the current study, 169 samples with negative AI from young patients and 18 samples from special cases were analyzed. Antibodies against the C6 peptide were found in 8 young patients and in 2 samples from special cases. Out of these, 3 young patients were stated positive for neuroborreliosis. Results of this study show that the C6 peptide ELISA on CSF samples could act as a complement to the current serological method for diagnosing neuroborreliosis. A combination of both methods could possibly increase the overall sensitivity. However, the blod-brain barrier injury issue is a problem in the analysis and interpretation of the results of the C6 peptide-based method on CSF should take into consideration a possible dysfunction of the blood-brain barrier. In conclusion, a combination of both the current method and the C6 peptide ELISA could give a markedly improved sensitivity in diagnostics of neuroborreliosis.
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Seroprävalenz von Tetanustoxoid-Antikörpern bei Pferden in Mitteldeutschland und Evaluierung ihrer Bestimmung mittels eines immunchromatographischen Schnelltestes / Seroprevalence of tetanus toxoid antibodies in horses in central Germany and evaluation of an immunochromatographic dipstick test for their determination

Recknagel, Stephan 27 November 2015 (has links) (PDF)
Trotz der längst etablierten und weit verbreiten Impfprophylaxe mit potenten Toxoidimpfstoffen sind dramatisch verlaufende Tetanusinfektionen noch immer im Alltag des Pferdepraktikers präsent. Dies gab Anlass, verschiedene Impfprotokolle und die daraus resultierende humorale Immunitätslage zu überprüfen. Kenntnis über die durch Vakzination erwirkte Tetanusimmunität ist im Falle der Versorgung von Verletzungen oder vor elektiven Eingriffen hinsichtlich der Entscheidung für oder gegen eine neuerliche aktive und/oder passive Immunisierung erforderlich. Weiterhin ermöglicht die Kontrolle auf Persistenz homologer maternaler Antikörper vor Durchführung der Erstvakzination eine optimale Impfprophylaxe. Für diese beiden Indikationen wurde der Fassisi® TetaCheck als direkt am Patienten anwendbarer Schnelltest entwickelt. Dieser Streifentest wurde mit besonderem Augenmerk auf der zuverlässigen Identifizierung nicht ausreichend geschützter Individuen und der Unempfindlichkeit gegenüber der Testdurchführung und Interpretation durch ungeschulte Personen evaluiert. Zunächst wurden 91 Serumproben von Klinikpatienten mit glaubhafter Impfanamnese mittels Doppel-Antigen-ELISA (DAE) untersucht. Neben der Bestimmung der Seroprävalenz protektiver Tetanustoxoid-Antikörperkonzentrationen (TTAK) von > 0,1 IE/ml in dieser Population wurden mögliche Einflussgrößen auf die Höhe der TTAK zum Zeitpunkt der Blutentnahme analysiert. Zu diesen zählten das Alter der Tiere, die Impfintervalle, der Zeitabstand zur letzten Vakzination und das gleichzeitige Verimpfen weiterer Komponenten. Der Tetanus-Streifentest (TST) wurde evaluiert, indem die durch zwei unabhängige Untersucher ermittelten qualitativen Resultate des Schnelltestes mit den mittels DAE quantifizierten Antitoxinkonzentrationen in 99 Serumproben retrospektiv verglichen wurden. Ergänzend erfolgte die objektive Quantifizierung der Farbreaktion im Testfeld des TST durch Fotografieren und anschließender Analyse mittels einer Bildbearbeitungssoftware. Die Seroprävalenz protektiver TTAK betrug 92,3 %. 89 % der untersuchten Pferde waren ihrem jeweiligen Alter entsprechend gemäß der ‚Leitlinie zur Impfung von Pferden‘, herausgegeben von der Ständigen Impfkommission Vet. des Bundesverbandes Praktizierender Tierärzte immunisiert. Fünf dieser Pferde waren jedoch nicht ausreichend geschützt. Hierzu zählten ein fünf Monate altes Fohlen, bei welchem die maternalen Antikörper bereits unter die Schutzgrenze abgefallen waren, zwei juvenile Pferde ohne abgeschlossene Grundimmunisierung und zwei adulte Pferde. Abweichungen von der Impfempfehlung bestanden ausschließlich in Form verlängerter Abstände der Wiederholungsimpfungen von drei bis zu acht Jahren. Trotzdem wiesen diese Tiere protektive TTAK auf. Unter alleiniger Betrachtung des Patientenalters wiesen alle geriatrischen Patienten (n = 12) TTAK weit oberhalb der Schutzgrenze auf. Hinsichtlich der Einhaltung unterschiedlicher Boosterintervalle unterschieden sich die TTAK nicht signifikant (p = 0,117). Der zeitliche Abstand zur letzten Tetanusimpfung ließ keine Prognose über die zu erwartenden TTAK zu. TTAK nach Impfung mit monovalenten Vakzinen unterschieden sich nicht signifikant von denen nach Durchführung einer Kombinationsimpfung (p = 0,63). Für den TST ergaben sich eine Sensitivität von 83,6 % und eine Spezifität von 100 %. Die Übereinstimmung der Untersucher hinsichtlich eines binären Resultats war fast vollkommen (K = 0,88). Die Durchführung des TST durch den jeweils anderen Untersucher hatte keinen maßgeblichen Einfluss auf die Auswertung des Teststreifens (K = 0,80 und K = 0,84). Durch Erweiterung des vom Hersteller vorgegebenen Bewertungsmaßstabes „negativ“, „schwach positiv“ und „positiv“ auf fünf unterschiedliche Farbintensitäten konnte eine bessere Differenzierung ungeschützter Individuen von Tieren mit belastbarer Immunität ermöglicht werden. Zwischen der objektiv gemessenen Farbintensität und der TTAK bestand ein positiver linearer Zusammenhang (r² = 0,74). Auf diesen Ergebnissen basierend sollte zur Vermeidung ineffektiver Immunisierungen vor der Erstvakzination eine Bestimmung der TTAK mit Vollendung des fünften Lebensmonats erfolgen. Hierzu erwies sich der Fassisi® TetaCheck aufgrund seiner Zuverlässigkeit und Unempfindlichkeit als überaus geeignet. Da auch das strikte Einhalten der Impfempfehlung keine ausreichende Seroprotektion garantiert und die Eintragungen im Pferdepass fehlerhaft sein können, kann nur über eine Bestimmung der TTAK Gewissheit über den tatsächlichen Immunstatus erlangt werden. Die routinemäßige Implementierung des TST in die Pferdepraxis kann dazu beitragen, die Notwendigkeit einer Immuntherapie zu diagnostizieren und damit unnötige und nebenwirkungsbehaftete TT- oder Antiserumgaben zu minimieren. Im zweijährlichen Abstand vorgenommene Wiederholungsimpfungen führen zu keiner besseren Immunitätslage gegenüber wesentlich längeren Impfintervallen. Die Impfempfehlung könnte daher ein acht- bis zehnjähriges Boosterintervall ausweisen. Die humorale Tetanusimmunität betreffend ergeben sich keine Nachteile bei gleichzeitiger Impfung weiterer Komponenten.
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Nachweis und Aufreinigung von Abscisinsäure-bindenden Proteinen aus dem Cytosol von Spinat- und Arabidopsis-Pflanzen / detection and purification of abscisic acid-binding proteins in the cytosol of spinach and Arabidopsis plants

Strauß, Michaela 24 April 2002 (has links)
No description available.

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