Made available in DSpace on 2014-06-11T19:33:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-31Bitstream added on 2014-06-13T21:06:05Z : No. of bitstreams: 1 furuta_pi_dr_jabo.pdf: 1073038 bytes, checksum: 5e772861c92b1e24fce5e65feea5cf02 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A neosporose é uma doença causada pelo protozoário Neospora caninum, e causa um grande impacto econômico na pecuária mundial. Sabe-se que muitos mamíferos são considerados hospedeiros intermediários, e que recentemente, foi confirmado o papel das aves no ciclo de vida de N. caninum como hospedeiros intermediários. O presente trabalho teve como finalidade estudar o ciclo evolutivo e patogenia de N. caninum em cães alimentados com ovos embrionados de Gallus gallus domesticus previamente inoculados com taquizoítas. Realizou-se diariamente o exame de fezes dos animais, pela técnica de flutuação, constatando a presença de oocistos nas fezes a partir de 7 dia apósinfecção. Anticorpos anti- N. caninum foram pesquisados semanalmente nos cães pela RIFI, sendo observados anticorpos a partir dos 14dai. Semanalmente um cão foi eutanasiado e durante a necropsia observou-se em todos os cinco animais, aumento dos linfonodos mesentéricos e das tonsilas, presença de muco no duodeno e jejuno e hepatoesplenomegalia, com hiperplasia de polpa branca do baço. Pelo exame histopatológico detectou-se reatividade dos linfonodos, lesões no fígado, coração, pulmão, baço e rim. Pelas técnicas de imunoistoquímica, imunofluorescência indireta dos tecidos e no Real-time PCR, observou-se a presença do parasito. Os resultados obtidos apontam que, os ovos embrionados infectados pelo parasito mostraram eficiência como modelo experimental para infectar cães, que eliminaram oocistos nas fezes, mesmo não apresentando sinais clínicos da neosporose. Ademais, os cães infectados apresentaram prematura soroconversão pela prévia administração de bicarbonato de sódio e o uso das técnicas citadas tornou possível a detecção do parasito nos tecidos analisados. / Neosporosis is a protozoan disease caused by Neospora caninum and affects the reproductive system in cattle worldwide. Infection by the parasite has been widely described in mammals, and recently the role of birds in its lifecycle was confirmed as intermediate hosts. This work aimed to study the life cycle of N. caninum and the pathogeny in dogs that were fed with embryonated eggs inoculated with tachyzoites. The tested dogs were followed up for oocyst shedding, by flotation technique, and it was detected at 7 days after infection. Antibodies anti- N. caninum were detected at 14dai. Once a week, one dog was euthanized and at the necropsy alterations was observed on the mesenteric lymph nodes and tonsils, presence of mucus at duodenum and jejunum portions, and hepatosplenomegaly. At the histopathological examination lymph nodes alterations were noticed ranging from moderate to intense. In addition, there were alterations in liver, heart, lung, spleen and kidney. The parasite was detected by immunochemistry and indirect immunofluorescense tests as well as by Real-time PCR. The results herein presented suggest that inoculated embryonated eggs showed to be an efficient model to infect dogs, because of shedding oocysts, and no clinical alterations. Moreover, the infected dogs presented earlier seroconvertion because of sodium bicarbonate solution administration and the parasite detection in the analyzed tissues was successful by the techniques used.

Vários estudos têm relatado um aumento da incidência de câncer de pele em todo o mundo. No Brasil, o câncer de pele em geral continua sendo a neoplasia mais incidente em ambos os gêneros. Os tumores de anexos cutâneos compõem um grupo grande de neoplasias que exibem diferenciação morfológica para um dos epitélios anexiais da pele normal. Este trabalho trata dos aspectos clínicos, histológicos e imunoistoquímicos de um tumor anexial de origem folicular: o triquilemocarcinoma e sua versão benigna o triquilemoma. Os objetivos foram analisar comparativamente os dados clínicos, epidemiológicos e a expressão de citoqueratinas 15 e 16, claudinas 1,3,4,5,7 e 11, antígeno CD34, do p63 e do índice de proliferação celular pelo Ki67 entre o grupo dos Triquilemomas e Triquilemocarcinomas diagnosticados na Divisão de Dermatologia do Hospital das Clínicas da Universidade de São Paulo no período de 1991 a 2009 e definir um padrão imunofenotípico que auxilie no diagnóstico diferencial dos dois tumores. O estudo foi feito através de revisão clínico-epidemiológica de prontuário dos casos diagnosticados no período de 1991 a 2009; revisão das lâminas em HE e PAS com e sem diastase; realização das técnicas de imunoistoquímica. No período de 18 anos foram identificados 22 casos válidos de triquilemoma e 16 casos válidos de triquilemocarcinoma. Observou-se uma maior incidência de Triquilemoma entre adultos masculinos enquanto que os Triquilemocarcinomas predominaram entre os idosos femininos. A cabeça foi mais acometida entre os casos benignos que entre os malignos. A opção terapêutica predominante entre os triquilemomas foi de eletrocoagulação e de excisão cirúrgica para os demais casos. A claudina-1, claudina-4 e o CD34 apresentavam medianas mais altas nos casos benignos que nos malignos. Portanto, conclui-se que os dados epidemiológicos e clínicos dos dois grupos de tumores se distinguem em relação à idade, gênero, local de acometimento e tipo de tratamento; observou-se perda de expressão das CL1 e 4 e do CD34, marcadores de diferenciação celular, nos Triquilemocarcinomas em comparação aos Triquilemomas. Por outro lado, o índice de proliferação celular pelo Ki67 mostrou-se um marcador inútil para a distinção entre as formas benigna e maligna / Several studies have been reporting an increasing incidence in skin cancers all over the world. In Brazil, skin cancers are the most prevalent neoplasia in both genders. The skin adnexal tumors are a large group of neoplasias that differentiate into normal skin adnexal epithelium. We report here the clinical, histopathological and immunochemical aspects of the tumors of follicular origin: the trichilemmal carcinoma and its benign variation - trichilemmoma. The objectives were to analise comparatively the clinical and histological data and to compare the expression of the cytokeratins 15 and 16, claudins 1,3,4,5,7 and 11, antigen CD34, p63 and the cell proliferation index in the Ki67 between the two groups, defining a immunophenotypic pattern that could help the differential diagnosis of the two tumors. The study was made by identifying in the hospital records the cases of these tumors between 1991 and 2009. After that, a clinico-epidemiological review was made in the medical records, the histological samples were reviewed to confirm the diagnosis. The best areas were selected to compose the Tissue MicroArray that was used to immunochemical reactions. In these 18 years, there were 22 valid cases of trichilemmoma and 16 of trichilemmal carcinoma. There was a higher incidence of trichilemmoma in male adults and of trichilemmal carcinoma in female elderly. The head was more affected in the benign tumors than in the malignat ones. The treatment option was electrodissection in Trichilemmomas and surgical excision in Trichilemmal carcinomas. Claudin-1, claudin-4 and CD34 were more expressed in the first group. So, we concluded that the clinical and epidemiological data in the two groups differ in age, gender, local of the tumor and treatment option. There was loss of expression of CL1 and 4 and of CD34, cell differentiation markers, in the Trichilemmal carcinoma when compared to the Trichilemmomas. On the other hand, the Ki67 expression was of no use in differentiating the two groups of tumor

No description available.

Le phylum Hemichordata est composé exclusivement d'organismes marins et, avec les embranchement Echinodermata et chordata, il forme le groupe des Deutérostomes sur l'arbre de la vie des animaux. Dans les chapitres d'introduction et le deuxième, je donne un aperçu des hémichordés, y compris les enteropneustes solitaires et les pterobranches coloniaux et je les défini dans un contexte évolutif ou phylogénétique. Les enteropneustes sont souvent considérés comme le meilleur proxy vivant de l'ancêtre des deutérostomes. Les ptérobranches comprennent les Cephalodiscida et les Graptolithina. Les graptolites (graptos = écrit, lithos = roche) sont principalement représentés par des espèces fossiles remontant à la Période Cambrienne, il y a plus de 500 millions d'années. Ces «écritures dans la roche» sont largement connues et étudiées par les paléontologues et sont si abondantes qu'elles sont utilisées comme fossiles indicateurs pour identifier les couches sédimentaires. Les graptolites sont éteints sauf pour cinq espèces benthiques appartenant au genre Rhabdopleura, membres de la famille Rhabdopleuridae, que j'examine en détail dans le chapitre trois. Rhabdopleura recondita de la mer Méditerranée fait l'objet de cette thèse. Il est courant le long des côtes sud de l'Italie d'où je l’ai échantillonné en plongée sous- marine. Il est inhabituel que des colonies résident cachées à l'intérieur de la zoaria des bryozoaires morts. Seuls les tubes érigés font saillie à partir de la matrice de l'hôte. Les chapitres quatre et cinq sont les contributions les plus significatives de cette thèse, avec un accent sur les tubes de R. recondita. Le chapitre quatre fournit des observations de la construction de tubes par R. recondita gardé en captivité. J'ai observé la capacité des larves, des zooïdes et des colonies à sécréter de nouveaux tubes en présence et en l'absence du matériel hôte du zoarium bryozoaire. Nous avons découvert que la colonisation larvaire et la sécrétion du dôme peuvent se produire sans l'hôte bryozoaire, mais la croissance continue de la colonie nécessite le substrat de l'hôte. Les zooïdes adultes ne peuvent reformer de nouveaux tubes que s'ils sont capables de s'abriter à l'intérieur du matériel hôte. Un résultat surprenant des observations des zooïdes a été la sécrétion d'un opercule et d'un tube évasé. Les colonies qui avaient des tubes érigés enlevés ont pu fabriquer de nouveaux tubes, mais à un faible nombre. Une étude parallèle a été réalisée sur des colonies dont les tubes avaient été retirés, puis cultivées dans des canaux à quatre vitesses d'écoulement. Cette expérience a été conçue pour induire une réponse plastique phénotypique à l'écoulement. Au lieu de cela, je n'ai trouvé aucune différence significative dans la longueur du tube ou le nombre de tubes en réponse à quatre vitesses d'écoulement. Ce résultat suggère que le développement du tube de R. recondita peut être canalisé ou fixé. Il est significatif car il suggère que de petites différences qui distinguent les espèces primitives de graptolites encroûtantes sont bonnes. Le chapitre cinq porte sur la composition des tubes de R. recondita. Plusieurs hypothèses et de nombreuses analyses ont été faites sur ce sujet, mais aucune n'a été concluante. J'utilise ici la génomique et la bioinformatique, l'immunochimie et la spectroscopie et rejette les hypothèses selon lesquelles les tubes sont de la kératine ou de la cellulose. Au lieu de cela, j'ai trouvé huit gènes de chitine synthase dans le génome et le trascriptome, un complexe composé d'un polysaccharide semblable à la chitine, d'une protéine, d'un acide gras et de composants élémentaires inattendus. Cette étude est significative car elle ferme la porte sur une ancienne hypothèse de composition de tube de graptolite et révèle qu'il s'agit d'une structure complexe comprenant de la chitine. Le chapitre de conclusion est un bref résumé des résultats et une réflexion sur les aveenues potentiellement fructueuse pour des recherches futures. / The phylum Hemichordata is comprised of exclusively marine organisms, and together with the Echinodermata and Chordata forms the Deuterostomia branch on the animal tree of life. In the introductory and second chapters I provide a background on Hemichordata including the solitary Enteropneusta and the colonial Pterobranchia and define them in an evolutionary or phylogenetic context. The enteropneusts are often regarded as the best living proxy of the deuterostome ancestor. Pterobranchs, include the Cephalodiscida and Graptolithina. Graptolites (graptos=written, lithos=rock) are mostly represented by fossil species dating back to the Cambrian Period, more than 500 million years ago. These “writings in the rock” are widely known and studied by paleontologists and are so abundant that they are used as index fossils to identify sedimentary layers. Graptolites are extinct but for five benthic species belonging to the genus Rhabdopleura, members of the Rhabdopleurida, which I extensively review in chapter three. Rhabdopleura recondita from the Mediterranean Sea is the subject of this thesis. It is common along the south coasts of Italy from where I sample it by SCUBA diving. It is unusual in that colonies reside hidden inside of the zoaria of dead bryozoans. Only erect tubes project from the host matrix. Chapters four and five are the most significant contributions of this thesis, with a focus on R. recondita tubes. Chapter four provides observations of tube building by R. recondita kept in captivity. I observed larvae, zooids and colonies abilities to secrete new tubes in the presence and absence of the bryozoan zoarium host material. We discovered that larval settlement and dome secretion can occur without the bryozoan host, but the continued growth of the colony requires the host substrate. Adult zooids can reform new tubes only if they are able to shelter inside of host material. A surprising result from the zooid observations was the secretion of an operculum and a flared tube. Colonies that had erect tubes removed were able to make new tubes, but fewer in number. A parallel study was done on colonies that had tubes removed and then were cultured in channels at four flow velocities. This experiment was designed to induce a phenotypic plastic response to flow. Instead, I found no significant difference in tube length or tube number in response to four flow velocities. This result suggests that the tube development of R. recondita may be canalized, or fixed. It is significant because it suggests that small differences that distinguish primitive, encrusting graptolite species, are good. Chapter five is on the composition of R. recondita tubes. Several hypotheses and numerous analysis have been done on this topic, but none were conclusive. Here I use genomics and bioinformatics, immunochemistry and spectroscopy and reject the hypotheses that the tubes contain keratin or cellulose. Instead I found eight chitin synthase genes in the genome and transcriptome, a complex made of a chitin-like polysaccharide, protein, fatty acid and unexpected elemental components. This study is significant because it closes the door on old hypothesis of graptolite tube composition and reveals that it is a complex structure including chitin. The conclusion chapter is a brief summary of the results and a reflection on fruitful avenues of future research.

Polycyclic aromatic hydrocarbons are environmental chemicals that are produced during incomplete combustion of coal, oil, gas, and garbage. Toxic effects of these compounds are mediated via the ligand activated Aryl Hydrocarbon Receptor (AHR) signaling pathway. To enable the study of the AHR signaling mechanism, our lab has generated many human proteins using recombinant DNA technology. This thesis documents the design and synthesis of a number of proteins of the AHR deletion construct CΔ553. The bacterial expressed and purified fusion proteins could be utilized as antigen to generate antibodies and be used for cellular delivery. The purified protein was immunogenic in rabbits and produced significant amount of polyclonal antibodies. In western blot analysis, the antibodies were able to the detect baculovirus expressed AHR and different recombinant proteins of the AHR. The polyclonal antibodies were also used in the gel-shift assay to show the AHR dependent gel shift. Cellular delivery CΔ553 was achieved using the protein transduction domain from the HIV-1 virus transactivating protein (TAT). In order to deliver the CΔ553 into mammalian cells, an expression vector was constructed to generate the TAT-CΔ553 fusion protein. The TAT-CΔ553 fusion protein was successfully transduced into two mammalian cells-HeLa and HepG2. The in vivo function of TAT-CΔ553 was determined using the luciferase reporter plasmid assay. The transduced protein was functional; it competed with the AHR and heterodimerize with ARNT in both HeLa and HepG2 cells at a concentration of 3.8x103 nM and 18 nM respectively. Since there an apparent similarity between the basic region of TAT-PTD and CΔ553, we examined the transduction potential of CΔ553. Western blot analysis indicated that the extent of denatured protein transduction was comparable for CΔ553 and TAT-CΔ553 in HepG2 cells. Thus CΔ553 might have intrinsic transduction capability.

No description available.

Allergic reactions are mainly mediated by the interactions between the IgE and its ligands, amongst them CD23 and CD21 in what is termed the IgE network. CD23 is involved in upregulating IgE expression by forming a trimolecular complex with CD21 and IgE on the B-cell surface, resulting in the specific activation of IgE-positive B cells. CD21 also interacts with C3d and is a bridge between the innate and the immune system. A crystal structure of the interaction has been solved (Szakonyi et al., 2001) but was controversial because it contradicted previous biochemical analyses. The aims of this thesis were to use various biophysical techniques to study the interactions between the molecules in the IgE network and its possible inhibition. Part 1: Characterisation of a phage display-derived peptide that inhibit IgE binding to CD23 A peptide was previously derived using phage display technology and tested for binding ability to CD23 using SPR and ITC. Subsequent NMR experiments were performed to identify the binding site, followed by characterization of its derivatives. Crystallisation of CD23 with the peptide and soaking with its truncated tripeptide, NWP, were also attempted. Part 2: Characterisation of CD23 and its interaction with its ligands X-ray crystallography was undertaken to solve the structure of derCD23 in complex with a phage display-derived peptide (Part1) followed by crystal soaking with a truncated tripeptide, NWP. However, a reproducible, high-resolution wild type derCD23 structure was determined at 1.9 Å. A comparison of the binding behaviour between the monomeric derCD23 and a trimeric CD23 construct was carried out in order to see the effect of oligomerisation upon IgE binding. Using the known interaction map as well as a crystal structure, the possible interacting residues between CD23 and IgE were examined. The characterisation of the CD23/CD21 interaction was continued from previous efforts in order to confirm that the binding epitope of CD23 for CD21 lies within the C-terminus of CD23. Characterisation of the interactions of CD23/IgE/FcεRI was performed to examine these multimolecular interactions and possible regulatory mechanisms in mast cell degranulation. It was shown that CD23 can form multimeric complexes with IgE-Fc that bind to FcεRI with higher apparent affinity than IgE-Fc alone, which may lead to increases in mast cell degranulation. It was also found that the IgE bound on FcεRI still binds to CD23 although with a lower binding capacity, presumably due allosteric changes. The binding of CD23 with a monoclonal antibody IDEC-152 was also characterised using SPR and NMR spectroscopy. It was proposed that IDEC-152 might interfere with the trimerisation site of CD23 thus reducing its affinity for IgE. A thermofluor assay was developed and optimised for potential screening of compounds that bind to derCD23 using a qPCR machine, which may be useful to screen compounds that bind to CD23 as part of future drug discovery project. Crystallisation of the derCD23/CD21 and IgE/triCD23/CD21 complexes was also attempted as part of ongoing crystallisation projects. Part 3: The interaction between C3d and CD21 The interaction between C3d and CD21 is believed to be a bridge between the innate and adaptive immune response, and is thought to be pivotal in the initiation of autoimmune disease. Following from previous studies on this interaction, further characterisations were performed using NMR and ITC to confirm the involved sites on CD21 (SCR1-2) in binding to C3d. Several potential salt bridges have been identified so far, allowing a high-resolution docked structure of the C3d/CD21 complex.

With the continued need for drug discovery and the quest to understand disease and treatment, there remains a requirement for improved methods to study protein-protein interactions and to identify potential drug leads for protein targets. We sought to develop a new approach to directly link genotype and phenotype to use as a probe for the identification of binding partners of proteins. The method creates millions of water-in-oil emulsions, each of which functions as a micro-environment for the amplification of a library of random peptide-encoding DNA molecules, which covalently bind to a bead. Subsequently the emulsions are broken and the bead-DNA complexes are recovered, which subsequently form another emulsion with in vitro transcription and translation components and incubated under suitable protein synthesis conditions. The synthetic peptide is designed with tags that link to the same bead which it is translated from. In chapter 3, the detailed design and optimisation of the method will be discussed. Cross-clade neutralising antibodies specific to HIV-1 are rare, partly because glycosylation restricts access to conserved backbone residues of gp120. In chapter 4, we hypothesized that peptides may have greater access than relatively large antibody structures, and so used our method to display random peptides on beads using a protein domain scaffold. Using a single round of selection, we identified 22 gp120-binding peptides, 4 of which were able to inhibit HIV-1 replication in vitro. One of the inhibitory peptides was found to bind the CCR5/CXCR4-binding site of gp120 and was able to inhibit clade B and C CCR5-tropic isolates of HIV-1. We have identified HIV-1 cross-clade neutralising peptides using a novel in vitro bead display library. Comprehensive antigenic characterization of a T cell population of unknown specificity is challenging. Existing MHC class I expression systems are limited by the practical difficulty of probing cell populations with an MHC class I peptide library and the cross-reactivity of T cells that are able to recognise many variants of an index peptide. We reasoned that a bead-based display high-throughput approach may overcome these challenges. Using emulsion PCR and emulsion in vitro transcription/translation of a random library of peptides conjugated to β-2-microglobulin on beads, we refolded with exogenous wild-type HLA-A*0201 or CD8-null A*0201 (domains 1 and 2 of HLA-A*0201 and domain 3 of Kb with mutated residues 226A/227L). The HLA bead libraries were used to probe HLA-A*0201-restricted T cells with specificity for influenza, CMV and EBV. High-throughput sequencing was used to rank sequences of identified peptides. Compared to pre-selection sequences, we observed significant enrichment for sequences containing HLA-A2 anchors and correct viral fragments for all T cell populations. HLA bead display provides a novel approach to identify the specificity of T cells. In summary, we combine the convenient handling of beads, the homogeneity of micro-environment in emulsion, and next-generation sequencing to create an attractive alternative to identify ligands of protein targets and antigenic peptides.

Orientadora: Rosangela Zacarias Machado / Banca: Ana Patrícia Yatsuda Natsui / Banca: Carlos Wilson Gomes Lopes / Banca: Aramis Augusto Pinto / Banca: Rosemeri de Oliveira Vasconcelos / Resumo: A neosporose é uma doença causada pelo protozoário Neospora caninum, e causa um grande impacto econômico na pecuária mundial. Sabe-se que muitos mamíferos são considerados hospedeiros intermediários, e que recentemente, foi confirmado o papel das aves no ciclo de vida de N. caninum como hospedeiros intermediários. O presente trabalho teve como finalidade estudar o ciclo evolutivo e patogenia de N. caninum em cães alimentados com ovos embrionados de Gallus gallus domesticus previamente inoculados com taquizoítas. Realizou-se diariamente o exame de fezes dos animais, pela técnica de flutuação, constatando a presença de oocistos nas fezes a partir de 7 dia apósinfecção. Anticorpos anti- N. caninum foram pesquisados semanalmente nos cães pela RIFI, sendo observados anticorpos a partir dos 14dai. Semanalmente um cão foi eutanasiado e durante a necropsia observou-se em todos os cinco animais, aumento dos linfonodos mesentéricos e das tonsilas, presença de muco no duodeno e jejuno e hepatoesplenomegalia, com hiperplasia de polpa branca do baço. Pelo exame histopatológico detectou-se reatividade dos linfonodos, lesões no fígado, coração, pulmão, baço e rim. Pelas técnicas de imunoistoquímica, imunofluorescência indireta dos tecidos e no Real-time PCR, observou-se a presença do parasito. Os resultados obtidos apontam que, os ovos embrionados infectados pelo parasito mostraram eficiência como modelo experimental para infectar cães, que eliminaram oocistos nas fezes, mesmo não apresentando sinais clínicos da neosporose. Ademais, os cães infectados apresentaram prematura soroconversão pela prévia administração de bicarbonato de sódio e o uso das técnicas citadas tornou possível a detecção do parasito nos tecidos analisados. / Abstract: Neosporosis is a protozoan disease caused by Neospora caninum and affects the reproductive system in cattle worldwide. Infection by the parasite has been widely described in mammals, and recently the role of birds in its lifecycle was confirmed as intermediate hosts. This work aimed to study the life cycle of N. caninum and the pathogeny in dogs that were fed with embryonated eggs inoculated with tachyzoites. The tested dogs were followed up for oocyst shedding, by flotation technique, and it was detected at 7 days after infection. Antibodies anti- N. caninum were detected at 14dai. Once a week, one dog was euthanized and at the necropsy alterations was observed on the mesenteric lymph nodes and tonsils, presence of mucus at duodenum and jejunum portions, and hepatosplenomegaly. At the histopathological examination lymph nodes alterations were noticed ranging from moderate to intense. In addition, there were alterations in liver, heart, lung, spleen and kidney. The parasite was detected by immunochemistry and indirect immunofluorescense tests as well as by Real-time PCR. The results herein presented suggest that inoculated embryonated eggs showed to be an efficient model to infect dogs, because of shedding oocysts, and no clinical alterations. Moreover, the infected dogs presented earlier seroconvertion because of sodium bicarbonate solution administration and the parasite detection in the analyzed tissues was successful by the techniques used. / Doutor

No description available.