Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-13T12:18:42Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_SoroepidemiologiaChlamydiaTrachomatisChlamydia.pdf: 2065401 bytes, checksum: 1da33c9028340a826d8e01d04fe2f763 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-04-22T13:32:53Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_SoroepidemiologiaChlamydiaTrachomatisChlamydia.pdf: 2065401 bytes, checksum: 1da33c9028340a826d8e01d04fe2f763 (MD5) / Made available in DSpace on 2014-04-22T13:32:54Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_SoroepidemiologiaChlamydiaTrachomatisChlamydia.pdf: 2065401 bytes, checksum: 1da33c9028340a826d8e01d04fe2f763 (MD5) Previous issue date: 2009 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A Chlamydia trachomatis e o Treponema pallidum compartilham com o HIV uma importante forma de transmissão: a via sexual. Por conta do comprometimento imunológico dos portadores de HIV, a C. pneumoniae pode apresentar um papel potencial em infecções respiratórias. Este trabalho objetivou a descrição da soroprevalência destes três agentes em portadores de HIV do Estado do Pará, Brasil. Entre setembro de 2007 a junho de 2008, foram coletadas 430 amostras de portadores de HIV em Belém, Pará. Estas foram submetidas a um ELISA para detecção de anticorpo IgG e IgM anti-Chlamydia e, dentre os positivos, uma amostragem aleatória foi escolhida e submetida à microimunofluorescência para sorotipagem. Para a detecção de anticorpos anti-Treponema pallidum foi feito um teste não treponêmico (RPR) e um teste treponêmico (ELISA). Os resultados obtidos foram analisados pelo teste do χ2. A prevalência geral de anticorpos anti-Chlamydia foi 64,2% (51,6% para IgG e 4% para IgM). A sorotipagem mostrou uma alta prevalência de C. trachomatis (100% tanto para IgG como IgM), e C. pneumoniae (73,5% IgG e 70,5% IgM), sendo que houve uma larga disseminação dos sorotipos que causam infecções genitais da Chlamydia trachomatis. A prevalência geral de anticorpos contra o Treponema pallidum foi de 34,9%, sendo que 7,3% apresentaram resultado laboratorial indicativo de sífilis. As variáveis que apresentaram associação com a infecção por Chlamydia e Treponema pallidum foram: o gênero masculino, maior idade, baixa escolaridade, número de parceiros por semana, a prática de sexo anal, homossexualismo/bissexualismo, uso de droga não-endovenosa, histórico de IST. Faz-se necessário tanto a conscientização como o monitoramento da população, para impedir a transmissão destes agentes e para a melhoria da qualidade de vida dos indivíduos portadores de HIV. / Chlamydia trachomatis and Treponema pallidum share the sexual route of transmission with HIV-1. In consequence of the compromise of the immune response among HIV-1 carriers, C. pneumoniae is a potential harassment in respiratory infections. The present study intended the description of the seroprevalence of those three agents among 430 HIV-1 infected persons residing in the State of Para, Brazil, attended at the State Reference Unit (URE-DIPE), between September 2007 to June 2008. Plasma samples were tested using an enzyme immuno assay for the detection of IgM and IgG antibodies to Chlamydia and those which elicited positive results were ramdomly selected for serotyping through a microimmunofluorescence assay. Antibodies to T. pallidum were detected using a flocculation reaction (RPR) and an enzyme immunoassay. Results were compared statistically using the Chi square test (χ2). The general prevalence to Chlamydia was 64.2% (51.6% IgG reactivity and 4% to IgM). Serotyping showed 100% reactivity to C. trachomatis (for both IgG and IgM), a high prevalence to C. pneumoniae (73.5% IgG and 70.5% to IgM) and a large distribution of reactivity to strains of C. trachomatis which cause genital infections. Prevalence of antibodies to T. pallidum was 34.9% and 7.3% showed laboratory evidence of syphilis. Infection with both pathogens were associated to several characteristics which included: higher prevalence among males, high age, low number of study years, high number of sexual partners, anal sexual relations, homosexual/bisexual habits, use of non injecting drugs and the history of sti. It is necessary not only the individual attention for prevention, but also the continuous monitoring to block transmission and the improvement of the well being of HIV-1 infected persons.

Social amoebae are eukaryotic organisms that inhabit soil of almost every climate zone. They are remarkable for their switch from unicellularity to multicellularity as an adaptation to starvation. When starved, millions of single cells aggregate and form a multicellular fruiting body, which contains reproductive spore cells and dead stalk cells, which help in spore dispersion. This costly behavior made social amoebae a model system for addressing major questions of the evolution of cooperation and multicellularity. In this study we look at three different aspects of social amoebae behavior; aggregation, non-aggregation and competition, and ask how they contribute to our understanding of cooperation in social amoebae and microbial systems in general.We explored the known but neglected observation that, upon starvation, not all cells aggregate and engage in multicellular development. We describe phenotypically and genetically non-aggregating cell proportion in D. discoideum species. Both aggregating and non-aggregating strategy are costly or beneficial depending on duration of starvation. With our computational model we propose that partitioning the population into unicellular and multicellular states is adaptive in fluctuating environments with unpredicted duration of starvation periods. Social amoebae may therefore lie at the intersection of cooperation and bet-hedging. In the second part, we provide a new framework for addressing the contrasting observations of high genetic diversity in natural populations of social amoebae and experimentally suggested low diversity-high relatedness required for cooperation. We propose that complex life cycle of social amoebae provides multiple competition points that can possibly play an important role in maintaining diversity and cooperation. We explore this experimentally and computationally by looking at competition over the whole life cycle between 6 natural isolates of D. discoideum. Our simulation model indicates that competition at different stages of the life cycle can lead to exclusion of "social winners". Though we failed to explain strain coexistence. Although preliminary, our results emphasize the importance of integrating species ecology in cooperative studies.Finally, we focus on a new aggregation dynamics in P. pallidum species observed in our lab. Aggregation is a population level process during which population gets divided into numerous subpopulations/aggregates that face selection independently. Such population partitioning can have strong evolutionary consequences on cooperation that have not yet been explored experimentally. We describe the population dynamics qualitatively and propose several quantitative measurements of population partitioning into aggregates. Our preliminary results suggest that there is a preference for aggregates of certain size, but there is no spatial organization of aggregates.

Dopamine is an important neurotransmitter that is involved in several human functions such as reward, cognition, emotions and movement. Abnormalities of the neurotransmitter itself, or the dopamine receptors through which it exerts its actions, contribute to a wide range of psychiatric and neurological disorders such as Parkinson’s disease and schizophrenia. Thus far, despite the great interest and extensive research, the exact role of dopamine and the causalities of dopamine related disorders are not fully understood. Here we have developed multimodal imaging methods, to investigate the release of dopamine and the distribution of the dopamine D2-like receptor family in-vivo in healthy humans. We use the [¹¹C]PHNO PET ligand, which enables exploration of dopamine-related parameters in striatal regions, and for the first time in extrastriatal regions, that are known to be associated with distinctive functions and disorders. Our methods involve robust approaches for the manual and automated delineation of these brain regions, in terms of structural and functional organisation, using information from structural and diffusion MRI images. These data have been combined with [¹¹C]PHNO PET data for quantitative dopamine imaging. Our investigation has revealed the distribution and the relative density of the D3R and D2R sites of the dopamine D2-like receptor family, in healthy humans. In addition, we have demonstrated that the release of dopamine has a functional rather than a structural specificity and that the relative densities of the D3R and D2R sites do not drive this specificity. We have also shown that the dopamine D3R receptor is primarily distributed in regions that have a central role in reward and addiction. A finding that supports theories that assigns a primarily limbic role to the D3R.

CONTEXTE La syphilis est une maladie ré-émergente depuis 2000. Son traitement est simple, mais son diagnostic est complexe. La technique d’amplification génique de Treponema pallidum (Tp-PCR) existe depuis 1990 mais le CDC l’a incluse dans sa définition de cas en janvier 2014. OBJECTIFS 1) Evaluer la performance diagnostique de la Tp-PCR à différents stades cliniques et milieux biologiques. 2) Mesurer la sensibilité, spécificité et les valeurs prédictives de la Tp-PCR en fonction de 3 groupes de référence dans des ulcères récents. 3) Comparer les performances des 2 principales cibles de Tp-PCR.MATÉRIEL ET MÉTHODES Premièrement, une revue systématique et méta-analyse des études publiées depuis 1990 ont été menées. Ensuite une étude multicentrique prospective a été conduite dans 5 villes européennes pendant 2 ans chez des patients avec un ulcère oro-génital. Tous ont reçu le test de référence local et 2 Tp-PCRs dans l’ulcère (gène tpp47 vs. polA). Les valeurs de sensibilité, spécificité et valeurs prédictives de la Tp-PCR ont été calculées comparativement au fond noir (FN), à la sérologie et à un gold standard amélioré. La concordance des 2 cibles a été évaluée par un coefficient kappa.RÉSULTATS PRINCIPAUX La méta-analyse conclut que la Tp-PCR a une meilleure performance dans les ulcères récents. L’étude clinique montre que la Tp-PCR décrit une meilleure performance comparativement au gold standard amélioré et a même une meilleure sensibilité que le FN. Les 2 cibles ont la même valeur diagnostique et une concordance quasi parfaite. CONCLUSIONS La Tp-PCR ciblant tpp47 ou polA est cliniquement utile pour diagnostiquer une syphilis primaire et pourrait même remplacer le FN sous certaines conditions. / BACKGROUND Syphilis has re-emerged in at-risk populations since 2000. Although the treatment of syphilis is simple, its diagnosis remains challenging. Treponema pallidum Polymerase Chain Reaction (Tp-PCR) has been used in the diagnosis of syphilis since 1990 but it is included in the case definition of the CDC since January 2014. OBJECTIVES 1) To assess the accuracy of Tp-PCR in various biological specimens and syphilis stages. 2) To measure its diagnostic performance (sensitivity, specificity and predictive values) in ulcers from early syphilis compared to three groups of reference. 3) To compare the accuracy of the two most currently used targets: tpp47 and polA genes.METHODS We conducted a systematic review and meta-analysis of all studies published from 1990. We implemented a multicentre, prospective, observational study in 5 European cities between 09/2011 and 09/2013 among patients with an oral or genital ulcer suggestive of syphilis. All patients were tested with traditional reference tests plus 2 Tp-PCRs (tpp47 and polA). We estimated the sensitivity, specificity and predictive values of Tp-PCR compared to darkfield microscopy (DFM), serology and an enhanced gold standard. We used the kappa coefficient to assess the agreement between the 2 targets.MAIN RESULTST p-PCR had the best accuracy in ulcers from early syphilis. Tp-PCR performed better when compared to the enhanced gold standard and had a higher sensitivity than DFM. The 2 Tp-PCRs had a similar accuracy and an almost perfect agreement.CONCLUSIONS Tp-PCR targeting either tpp47 or polA is clinically useful to confirm an early syphilis in smears and could even replace DFM under specific conditions.