Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2016-02-19T13:19:42Z No. of bitstreams: 1 Clarissa Cunha Santana Avaliação... 2015.pdf: 1937824 bytes, checksum: 1d212794cc3bec0caa6b8414a186531b (MD5) / Approved for entry into archive by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2016-02-19T13:19:53Z (GMT) No. of bitstreams: 1 Clarissa Cunha Santana Avaliação... 2015.pdf: 1937824 bytes, checksum: 1d212794cc3bec0caa6b8414a186531b (MD5) / Made available in DSpace on 2016-02-19T13:19:53Z (GMT). No. of bitstreams: 1 Clarissa Cunha Santana Avaliação... 2015.pdf: 1937824 bytes, checksum: 1d212794cc3bec0caa6b8414a186531b (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / A malária é uma doença causada por cinco espécies de parasitos do gênero Plasmodium que causa anualmente a morte de milhares de pessoas, principalmente em países pobres da África. Muito antiga, uma diversidade de fármacos já foram empregados na tentativa de erradicação da doença, entretanto o aparecimento de cepas resistentes, bem como efeitos adversos gerados pelo tratamento impossibilitou tal ação. Os quinolínicos configuram uma grande parte destes tratamentos, apresentando uma notável atividade antimalárica. Neste trabalho nós avaliamos o potencial antimalárico de três novos derivados quinolínicos BS 260, BS 318 e BS 373 em culturas de Plasmodium falciparum, cepa w2, cloroquina resistente. BS 373 apresentou melhor atividade contra culturas de Plasmodium falciparum e, assim como o BS 318, foi capaz de inibir a biocristalização de hemozoína pelos parasitos. A microscopia eletrônica de transmissão revelou uma desorganização celular, diminuição do tamanho e quantidade de cristais de hemozoína no vacúolo digestivo, bem como vacuolizações citoplasmáticas e presença de estruturas membranares no vacúolo digestivo, o que indica a ocorrência de um processo autofágico nas células tratadas com 10 LM e 20 LM do BS 373. A presença de cristais citoplasmáticos indica a ocorrência de autólise pela ruptura da membrana do vacúolo digestivo. Por fim, o efeito dos tratamentos se mostrou irreversível nos parasitos com 24 horas de tratamento para BS 318 e BS 373, enquanto que para BS 260 essa irreversibilidade só foi observada após 48 horas. Nossos dados mostram que os derivados quinolínicos testados são efetivos contra culturas de P. falciparum, configurando bons candidatos à novas moléculas antimaláricas. / Malaria is a disease caused by five Plasmodium species that cause deaths of thousands of people annually, mostly in poor countries of Africa. Very anccient, a variety of drugs have been used in an attempt to eradicate the disease, however the emergence of resistant strains, as well as adverse effects caused by treatment prevented such action. The quinoline are a large part of these treatments, presenting a remarkable antimalarial activity. In this paper we evaluate the antimalarial potential of three new quinoline derivative BS 260, BS 318 and BS 373 in Plasmodium falciparum chloroquine resistant, w2 strain, cultures. BS 373 showed the best activity against Plasmodium falciparum cultures, while and analogously to BS 318 was able to inhibit the hemozoin formation by parasites. The transmission electron microscopy revealed a cell disorganization, decreased size and amount of hemozoin crystals in the digestive vacuole, cytoplasmic vacuolization and presence of membrane structures in the digestive vacuole, which indicates an autophagic process in cells treated with 10 LM and 20 LM BS 373. Cytoplasmic being crystals indicate parasite cell autolusis caused by digestive vacuole membrane disrupture. Finally, the effect of treatment proved irreversible on parasites at 24 hours of treatment for BS 318 and BS 373, whereas for BS 260 this irreversibility was only observed after 48 hours. Our data show that the quinoline derivatives tested are effective against P. falciparum cultures, setting good candidates for new antimalarial molecules.

La malaria est la 1ère parasitose mondiale du fait de son taux de morbidité et de mortalité. Elle est responsable de 198 millions de cas dont 584 000 décès en 2013 (OMS). La forme la plus sévère est due à l’apicomplexe Plasmodium falciparum. Etant donné l’absence d’un vaccin efficace et l’augmentation des résistances aux traitements, il est crucial d’approfondir nos connaissances sur la biologie de P. falciparum afin de trouver de nouvelles cibles thérapeutiques. Le cycle de vie complexe avec deux hôtes nécessite une régulation précise et dynamique de l’expression des gènes et des modifications post-traductionnelles. Dans ce contexte, il a été montré que les kinases et les phosphatases, impliquées dans les processus de phosphorylation et de déphosphorylation respectivement, jouent un rôle crucial pour la survie du parasite. Chez les eucaryotes, les phosphatases sont impliquées dans la croissance cellulaire, la différentiation et la division. Parmi elles, PP1, une des principales sérine/thréonine phosphatases, est composée d’une sous-unité catalytique (PP1c) et d’une sous-unité régulatrice. Ces régulateurs sont essentiels et confère à PP1 une localisation, une spécificité et une régulation de son activité. La majorité des régulateurs interagissent avec PP1c via différents motifs tel que le motif RVxF. Chez P. falciparum, PP1 (PfPP1c) est exprimée et semble être essentielle au niveau du stade érythrocytaire, en particulier dans la libération des mérozoïtes infectieux. Pour mieux comprendre la fonction de PfPP1c, nous étudions les régulateurs de PP1 chez le parasite. Nos études précédentes nous ont permis de caractériser 3 régulateurs au niveau moléculaire et fonctionnel. Dans ce contexte, nous avons montré que PfLRR1 et PfI2 inhibent l’activité de PP1 alors que PfI3 l’active. Des études de génétique inverse suggèrent que ces régulateurs sont aussi essentiels que la PP1c elle-même. Récemment, nous avons identifié dans le génome de P. falciparum le facteur d’initiation de la traduction de type 2 sous-unité ß (eIF2ß) qui pourrait être un partenaire/régulateur potentiel de PfPP1. Dans la 1ère partie de cette étude, l’objectif principal a été d’étudier la présence de motifs additionnels de fixation à PfPP1c dans PfI2 et leur impact sur sa fonction. En utilisant la RMN, un troisième motif d’interaction FxxR/KxR/K a été identifié. Ce motif a été montré comme agissant de concert avec le motif canonique RVxF. En effet, la mutation des deux motifs abolie complètement l’interaction avec PfPP1. De plus, en utilisant le modèle d’ovocytes de Xénope, nous avons montré que ces motifs sont nécessaires à PfI2 pour réguler l’activité de PP1. Finalement, l’utilisation d’un peptide dérivé du motif d’interaction FxxR/KxR/K de PfI2 a montré une accumulation dans les érythrocytes infectés et un effet anti-plasmodial a été observé. Dans la 2ème partie de cette étude, nous avons étudié eIF2β, un autre régulateur potentiel de PfPP1. Par des expériences de GST pull-down, nous avons montré l’interaction entre PfeIF2β/PfPP1 et deux motifs d’interaction ont été identifiés : RVxF et FxxR/kxR/K. De plus, en utilisant le modèle d’ovocytes de Xénope, nous avons démontré que PfeIF2ß est impliqué dans la transition G2/M, suggérant un rôle inhibiteur sur l’activité de PP1. La mutation d’un des deux motifs n’empêche pas la formation du complexe alors que la mutation des deux abolie l’interaction avec PP1. Afin de déterminer la fonction de PfeIF2ß in vivo chez Plasmodium, des expériences de génétique inverse ont été réalisées. Nous avons montré l’accessibilité au locus du PfeIF2ß par Knock-in et des expériences d’interruption du gène elf2ß chez Plasmodium falciparum et berghei (espèce spécifique aux rongeurs) sont actuellement en cours afin de déterminer l’essentialité de cette protéine dans le développement du parasite. / Malaria is still the most severe infectious disease in the world because of its high rate of morbidity and mortality. Malaria is responsible for 198 million cases among which 584 000 deaths in 2013 (WHO). The most deadly parasite is the Apicomplexa Plasmodium falciparum. Given the lack of efficient vaccine with long-lasting protection and the increase of resistance against current treatments it is crucial to further deepen our understanding the biology of Plasmodium falciparum to find new means of control. The complex life cycle within two hosts necessitates a highly accurate and dynamic regulation of gene expression and of post translational modifications. In this context, it has been shown that kinases and phosphatases, involved in phosphorylation/dephosphorylation processes respectively, play a key role in parasite survival. In eukaryotes, phosphatases have been shown to be involved in cell growth, differentiation and division. Among them, Protein phosphatase type 1 (PP1) has been reported as one of the major serine/threonine phosphatase proteins involved in diverse cellular functions. PP1 is composed of a single catalytic subunit (PP1c) with a capacity to interact with a high number of regulatory subunits. These regulators are essential as they are key players in different roles of PP1c, including its trafficking, activity and specificity. Most of regulators interact with PP1c via several binding motifs including the RVXF motif. In Plasmodium falciparum, PP1c (PfPP1c) is expressed and seems to be essential for blood stage parasite, in particular merozoïte liberation. To better understand the function of PfPP1c, we investigated the regulators of protein phosphatase type I in this parasite. Our earlier studies have characterized three regulators at the molecular and functional levels. In this context, we have shown that PfLRR1 and PfI2 inhibit PP1 activity while PfI3 activates it. Reverse genetic studies suggested that these regulators are as essential as the PP1c itself. Recently, we found in P. falciparum genome the eukaryotic translation initiation factor 2 subunit ß (eIF2ß) which could be a potential partner/regulator of PfPP1. In the first part of this study, the main objective was to further explore in PfI2 the presence of additional motifs of binding to PfPP1c and their impacts on its function. Using NMR spectroscopy, a third motif was identified: FxxR/KxR/K. This motif has been found to act together with the canonical motif RVxF. Indeed, mutations in both motifs abolished completely the interaction with PfPP1. In addition, using Xenopus oocytes model, we showed that both motifs were necessary for PfI2 to regulate the activity of PP1. Finally the use of a peptide spanning the FxxR/KxR/K motif of PfI2 regulator showed an accumulation in infected erythrocytes and an antiplasmodial effect was observed.In the second part, we investigated eIF2ß as a potential regulator of PfPP1. By GST pull-down assays, we have shown the interaction between PfeIF2ß/PfPP1 and two binding motifs were identified : RVxF and FxxR/KxR/K motifs. Moreover, using Xenopus oocytes model, we demonstrated that PfeIF2ß is involved in G2/M transition, suggesting an inhibitor function of PP1 activity. Mutation of one of two motifs did not prevent the interaction while mutation of both abolished this binding. To gain more insights on the function of PfeIF2ß in Plasmodium, reverse genetic experiments were carried out. We have shown the accessibility of PfeIF2ß locus by Knock-in and we are performing Knock-out experiments on Plasmodium falciparum and berghei (specific species of the rodents) to determine the essentiality of this protein for parasite development.

Objetivos: Desenvolver, caracterizar e avaliar a eficácia in vivo e o perfil farmacocinético de suspensões de nanocápsulas (NC) poliméricas contendo quinina (QN). Metodologia: As NC-QN foram preparadas através de nanoprecipitação com diferentes concentrações de QN: 2 (NC2-QN), 3 (NC3-QN) e 4 mg/mL (NC4-QN). A NC4-QN também foi revestida com quitosana. Todas as formulações foram caracterizadas através de taxa de encapsulação, teor, diâmetro, índice de polidispersão, potencial zeta e pH, sendo a estabilidade avaliada por 30 dias. A avaliação da eficácia foi realizada com diferentes doses de cada formulação, em modelo de malária experimental em ratos Wistar infectados com Plasmodium berguei. A dose de NC-QN com a qual se obteve 100 % de cura dos animais foi selecionada para a avaliação farmacocinética. Nesses experimentos, os animais sadios ou infectados receberam a QN livre ou a NC2-QN, 25 mg/kg, iv bolus. As amostras de plasma coletadas em tempos pré-determinados foram quantificadas por CLAE com método validado para a determinação da QN. Os protocolos com animais foram aprovados pelo Comitê de Ética em Pesquisa da UFRGS (#2005477). Resultados e discussão: As suspensões coloidais preparadas com diferentes concentrações de QN apresentaram diâmetro adequado, população modispersa, potencial zeta diferente de zero, doseamento e taxa de encapsulação superior a 90 %. Somente a NC2-QN, na dose de 75 mg/kg/dia, q8h, curou todos os animais. Nas doses de 30 e 60 mg/kg/dia, q8h, 28,6 e 85,7% dos animais sobreviveram, respectivamente, com a NC2-QN. Houve uma diminuição significativa no t½ das NC2-QN (32,9 ± 8,9 min) em relação ao fármaco livre (69,8 ± 44,6 min), no grupo de animais infectados (α = 0,05) em função de uma tendência de aumento do CLtotal (7,1 ± 3,3 versus 9,9 ± 2,1 L/h/kg) do fármaco nanoencapsulado. Conclusões: A nanoencapsulação da QN reduziu a dose efetiva do fármaco no modelo animal avaliado em 30 % e aumentou a sobrevivência dos animais infectados em cerca de 60 %, apresentando-se como uma alternativa potencial para o tratamento da malária. / Objectives: The aims of this study were to develop and characterize polymeric nanocapsules (NC) containing quinine (QN) and to evaluate their efficacy in vivo as well as the pharmacokinetic profile of the nanoencapsulated drug. Methodology: NC-QN were prepared by nanoprecipitation with different drug concentration 2 (NC2- QN), 3 (NC3-QN) and 4 mg/mL (NC4-QN). All formulations were characterized in terms of encapsulation efficacy, drug loading, zeta potential, particle size, polydispersion index, and pH. The stability nanocapsules suspensions were evaluated during 30 days. An experimental malaria model with Plasmodium berghei was used to evaluate NC-QN efficacy in Wistar rats. Different doses were tested for each formulation. The pharmacokinetic evaluation was performed with the dose of NC–QN which presented 100 % efficacy in malaria model. The NC2-QN or QN free were administrated by i.v. route (25 mg/kg) to health and infected rats. Blood samples were collected at pre-determinated time points and quantified by an HPLC validated method. Animal protocols were approved by UFRGS Ethics in Research Committee (# 2005477). Results and discussion: All suspensions presented adequate particle size, monodisperse population, negative zeta potential, drug content and encapsulation efficiency higher than 90 %. The formulation NC2-QN (75 mg/kg/day) administrated q8h daily during 7-9 days post-infection cured all infected rats. For NC2-QN, 30 and 60 mg/kg/day, q8h, 28.6 and 85.7 % of survival were observed, respectively. NC2-QN presented significant decrease in QN t½ compared to the free drug (32.9 ± 8.9 min and 69.8 ± 44.6 min, respectively), in infected rats (α = 0,05). This occurs due to the tendency of increase in CLtotal (7.1 ± 3.3 to 9.9 ± 2.1 L/h/kg, for free QN and NC2-QN, respectively). CLtotal increased in the encapsulated group. Conclusion: Nanoencapsulation reduced QN effective dose in 30 % and increased in 60 % the survival of the infected animals. Theses results indicate that NC-QN is a potential strategy to be investigated for malaria treatment.

L'artémisinine (ART) est un composé antipaludique majeur très actif sur les souches multi-résistantes de Plasmodium falciparum. Cependant, son application clinique est limitée par sa faible solubilité en milieu aqueux et sa faible biodisponibilité par voie orale. La mise en œuvre de cyclodextrines (CDs) bioestérifiées et de dérivés amphiphiles polyoxyéthylénés permet de viser deux objectifs : i) d'une part d'améliorer la concentration aqueuse d'ART à travers son association aux vecteurs colloïdaux de CDs modifiées et ii) d'autre part d'améliorer sa biodisponibilité et son efficacité thérapeutique à travers la décoration de la surface des vecteurs. La décoration surfacique est sensée augmenter le temps de circulation sanguine des nanovecteurs de manière à maintenir des doses plasmatiques efficaces d'ART sur une longue période, suite à une administration intraveineuse. Des suspensions colloïdales stables suffisamment chargées d'ART ont été mises au point permettant de palier le problème d'insolubilité en milieu aqueux de la molécule active et donc d'envisager son administration par voie parentérale. Les essais de lyodisponibilité indiquent que l'ART est libérée des nanosystèmes pendant une période de 4 jours pour les nanoréservoirs et de 11 jours pour les nanosphères. En plus des caractérisations physico-chimiques et pharmacotechniques, les potentialités des nanoparticules décorées en surface ont été évaluées et comparées au cours de tests biologiques. In vitro, l'ART mise en forme a montré une bonne efficacité sur des souches plasmodiales choloroquino-sensibles (3D7) et chloroquino-résistantes (K1) avec des CI50 très faibles de l'ordre de 3 à 6 ng/mL. Le concept de co-nano-assemblage de dérivés amphiphiles de γ-CD-C10 bioestérifiée et de polyéthylène glycol (PEG) dans les conditions de nanoprécipitation semble être une approche intéressante pour conférer des propriétés de furtivité aux nano-systèmes de γ-CD-C10. En effet, les études in vitro mettent en évidence une diminution significativement de la phagocytose par les cellules macrophagiques et/ou de l'adsorption des protéines du complément sérique à la surface des nanoparticules de γ-CD-C10 décorées par le polysorbate 80, le stéarate de PEG1500, et le DMPE-mPEG2000. In vivo, nous observons une augmentation du temps de circulation sanguine des nanoréservoirs γ-CD-C10/polysorbate 80 et des nanosphères γ-CD-C10/DMPE-mPEG2000. Enfin, les études de pharmacocinétique réalisées chez le rat montrent que les paramètres pharmacocinétiques de l'ART sont améliorés lorsqu'elle est associée aux deux systèmes nanoparticulaires précédents. En effet, des valeurs de clairance plasmatique très faibles et de temps de demi-vie plasmatique longs (3 et 5 heures, respectivement) de l'ART ont été enregistrées avec ces deux formulations. Ces formes vectorisées d'ART mises au point ouvrent de perspectives intéressantes pour la prise en charge thérapeutiques des crises de paludisme sévère. / Artemisinin (ART), an endoperoxide sesquiterpene lactone antimalarial drug isolated from a Chinese medicinal herb (Artemisia annua), has a fast action against chloroquine-sensitive and chloroquine-resistant strains of P. falciparum, making it very effective in the treatment of multidrug-resistant malaria. However, its poor aqueous solubility, short half-life, and high first-pass metabolism limit its use in therapeutics. The purpose of the present study was to investigate the potential of self-assembled bio-transesterified CD-based nanocarriers as ART delivery systems for an intravenous route. The objective of our study was twofold: (i) to improve the ART dosage through its association with CD esters-based nanocarriers, (ii) to ensure a sufficient blood circulation time of the nanocarriers through their surface decoration, which is a prerequisite to reach infected erythrocytes after systemic administration. Stable colloidal suspensions with good ART association rate were developed to solve the problem of insolubility in aqueous medium of the active molecule and therefore consider its parenteral administration. The γ-CD-C 10 based nanospheres showed a significant sustained release profile of ART extended up to 4 days for nanosphères and 11 days for nanoreservoirs. In addition to the physicochemical characterizations, the potential of nanoparticles decorated on the surface were evaluated and compared in biological tests. The results from this study indicate that ART-loaded nanosystems, mainly PEGylated ones exhibit satisfactory in vitro activity against Chloroquine-sensitive (3D7) and chloroquine-resistant (K1) strains of P. falciparum with very low IC50 of the order of 3 to 6 ng / mL. The concept of co-assembly of nano-amphiphilic derivatives of γ-CD-C10 bioestérifiée and polyethylene glycol (PEG) under conditions of nanoprecipitation seems to be an interesting approach to impart stealth nano-systems-γ-CD C10. Indeed, in vitro studies show a significant decrease in phagocytosis by macrophages and/or adsorption of serum complement proteins on the surface of nanoparticles of γ-CD-C10 decorated by polysorbate 80, PEG1500 stearate, and mPEG2000-DMPE. In vivo, we observed an increase in blood circulation time of nanoreservoirs γ-CD-C10/polysorbate 80 and nanospheres γ-CD-C10/DMPE-mPEG2000. Finally, pharmacokinetic studies in rats show that the pharmacokinetics of ART are enhanced when combined with previous two nanoparticle systems. Indeed, values of plasma clearance and very low time of long plasma half-life (3 to 5 hours, respectively) of ART were recorded with both formulations. These colloidal forms of ART developed open up interesting prospects for the therapeutic treatment of severe malaria.

Resumo: O sistema sangüíneo ABO (sABO) é o mais importante sistema na compatibilidade de grupos sangüíneos. Muitas pesquisas têm mostrado associações deste sistema com várias doenças infecciosas, inclusive a malária. Este estudo avaliou a associação entre os genótipos do sistema histo-sangüíneo ABO e a malária não grave causada pelo Plasmodium falciparum. A genotipagem dos grupos sangüíneos do sistema ABO foi feita de acordo com o protocolo de PCR/ RFLP, em amostras de indivíduos maláricos e não maláricos de áreas da Amazônia brasileira. O genótipo homozigoto ABO*O01O01 foi prevalente tanto nos maláricos quanto nos doadores de sangue. O genótipo ABO*AB representou cerca de 3% da população infectada e 5% da não infectada. Não foram verificadas diferenças estatisticamente significantes na comparação das freqüências alélicas e genotípicas do sABO entre pacientes e grupo controle, mesmo quando foram analisados apenas indivíduos com infecções puras de P. falciparum. A freqüência do sABO na Amazônia brasileira pode estar relacionada com a baixa freqüência de malária grave pelo P. falciparum. Portanto, os genótipos encontrados no sistema ABO dos indivíduos maláricos e não maláricos pode promover relevantes informações, para o entendimento da epidemiologia da malária grave por P. falciparum na Amazônia brasileira. / Abstract: The ABO blood system (sABO) is the most important system on the blood groups compatibility. Several studies have shown its associations with various infectious diseases, including malaria. This study evaluated the association between the ABO histo-blood genotypes and non-severe malaria caused by Plasmodium falciparum. PCR/RFLP protocol had be used for both ABO blood group system genotyping in malaria suffering individuals and blood donors, from malaria areas of the Brazilian Amazon. The homozygous genotype ABO*O01O01 was prevalent in both malaria and the blood donors. The genotype ABO*AB represented about 3% of the infected population and 5% of non-infected. No statistically significant differences were observed in sABO genotypic and allelic frequencies of patients and the control group, even when individuals were analyzed only with pure infection of P. falciparum. The frequency of sABO in the Brazilian Amazon may be related to the low frequency of non-severe malaria P. falciparum. Therefore, the genotypes found in the ABO blood system in malaric and non-malaric individuals can promote relevant information for the understanding of the severe malaria by P. falciparum epidemiology in the Brazilian Amazon. Keywords: Malaria; ABO blood group system; Plasmodium falciparum. / Orientador: Ricardo Luiz Dantas Machado / Coorientador: Luiz Carlos de Mattos / Banca: Carlos Eugênio Cavasini / Banca: Irineu Luiz Maia / Mestre

A malária é uma das principais doenças parasitárias no mundo, e o aumento da resistência aos antimaláricos atualmente utilizados dificulta o controle dessa parasitose. Assim, é de interesse a descoberta de novas vias metabólicas que sirvam de alvos para o desenvolvimento de drogas para combater essa doença. Nosso laboratório, nos últimos anos, tem investido na caracterização de intermediários e produtos finais da via de isoprenóides. Baseando-se na presença das vias 2-C-metil-D-eritritol 4-fosfato e do chiquimato, decidimos verificar se ocorriam as biossínteses de retinóides e vitamina K no ciclo intraeritrocitário do P. falciparum, através da análise de produtos metabolicamente marcados com [1(n)-3H]-pirofosfato de geranilgranila por análises cromatográficas (HPLC e TLC), além da espectrometria de massas. Não identificamos a presença de retinal, retinol e ácido retinóico no ciclo intraeritrocitário do P. falciparum. Já a biossíntese de vitamina K precisa ser estudada com mais profundidade, pois há indícios de biossíntese, em especial da menaquinona-4. / Malaria is one of the most important parasitic diseases in the world. The spread of resistance to the antimalarials impairs the parasite\'s control. Therefore, is necessary the discovery of new metabolic routes to allow new antimalarials development. Our group has been studying the isoprenoid pathway, characterizing the intermediate and secondary products of this pathway. Based on the presence of 2-C-methyl-D-erythritol 4-phosphate and shikimate pathways, we decided to investigate the occurrence of retinoids and vitamin K biosynthesis in P. falciparum, through the chromatography of [1(n)-3H]Geranylgeranylpyrophosphate labeled products of intraerythrocytic stages of P. falciparum, and mass espectometry analysis. The retinal, retinol and retinoic acid were not identified in P. falciparum. The results indicate the menaquinone-4 biosynthesis, although deeper investigation is necessary.

O diagnóstico da malária tem como teste de referência a gota espessa, porém é consenso que é preciso adotar alternativas em situações específicas, com técnicas mais sensíveis e que possam ser aplicadas no processamento de grande número de amostras, como estudos clínicos, epidemiológicos ou triagem de doadores em bancos de sangue. Com a finalidade de formar uma plataforma de diagnóstico para malária em amostras agrupadas em pools, foi realizada análise comparativa da PCR em tempo real, a nested PCR e um teste rápido específico para detecção de anticorpos contra P.falciparum e P. vivax, com intuito de reduzir o número de ensaios, com custo relativamente baixo. Foram utilizadas 50 amostras de sangue positivas para Plasmodium, de acordo com a prevalência das espécies no Brasil (P. vivax 75%, P. falciparum 22% e P. malariae 3%), com diagnóstico realizado pelo método padrão ouro. Adicionalmente, 48 amostras de sangue negativas para Plasmodium foram selecionadas para controle negativo e confecção de 15 pools, contendo amostras positivas e negativas. Quatro das amostras negativas para malária eram positivas para outras doenças. Tanto as amostras positivas como as negativas foram submetidas individualmente aos ensaios de PCR em tempo real, nested PCR e teste imunocromatográfico SD Bioline Pf/Pv para detecção de malária. Um teste de PCR convencional foi incluído a fim de testar a qualidade do DNA, mediante amplificação de uma sequência do gene humano da -globina como controle interno. Posteriormente as amostras foram analisadas em pools pelos ensaios moleculares e sorológicos. Nos testes individuais, 45/49 amostras foram positivas para Plasmodium pela PCR em tempo real, com Sensibilidade de 91,84%, e Especificidade (48/48) de 100,00%; 46/49 amostras detectaram Plasmodium pela nested PCR, com Sensibilidade de 93,88%, e Especificidade (12/12) de 100,00%; 32/46 amostras foram reagentes no teste sorológico SD Bioline Pf/Pv, com Sensibilidade de 69,56%, e Especificidade (10/10) de 100,00%. Nos ensaios com amostras agrupadas, 13 pools (86,66%) foram positivos pela PCR em tempo real; a nested PCR também obteve positividade nos mesmos 13 pools (86,66%). O teste imunocromatográfico SD Bioline apresentou Sensibilidade de 73,33% considerando o diagnóstico pela gota espessa. Tanto a PCR em tempo real como a nested PCR apresentaram boa sensibilidade e especificidade, seja nas amostras clínicas analisadas individualmente ou em pools, diferentemente do teste sorológico SD Bioline. Ambas as metodologias moleculares apresentaram desempenho semelhante, com bons resultados de acurácia e indicadores de validade, como Sensibilidade, Especificidade, Valor Preditivo Positivo e Negativo. Considerando-se as vantagens inerentes à PCR em tempo real, como rapidez, processamento em sistemas fechados e dispensa de eletroforese após amplificação, este método deve ser indicado como primeira escolha para diagnóstico de malária em grande número de amostras, seguido da nested PCR para diferenciação de espécies de Plasmodium. O teste sorológico, que é específico para detecção de anticorpos contra P. vivax e P. falciparum, pode ser indicado apenas como método complementar no diagnóstico de malária / The diagnosis of malaria is based on the thick blood film as reference test, but the consensus is that it is necessary to adopt alternatives in specific situations, with more sensitive techniques that could be applied in the processing of large numbers of samples in clinical and epidemiological studies or in the screening of donors at blood banks. The purpose of this study was to analyze and compare the real-time PCR, the nested PCR and a rapid test for detection of specific antibodies against Plasmodium falciparum and P. vivax, to build a platform for malaria diagnosis in pooled samples, reducing the number of tests and providing relatively low cost. For the tests analysis, we used 50 blood samples positive for Plasmodium, according to the prevalence of the species in Brazil (75% P. vivax, 22% P. falciparum and 3% P. malariae), with diagnosis performed by the gold standard method. In addition, 48 blood samples negative for Plasmodium were selected for negative control and production of 15 pools containing positive and negative samples. Four of the malaria negative samples were positive for other diseases. Both the positive and negative samples were submitted to individual testing of real-time PCR, nested PCR and immunochromatographic test SD Bioline Pf/Pv for the detection of malaria. To check the quality of DNA, a conventional PCR was included, with amplification of a sequence of the -globin human gene as internal control. Subsequently the samples were analyzed in pools by molecular and serological tests. In individual tests, 45/49 samples were positive for Plasmodium by real time PCR, with sensitivity of 91.84% and (48/48) 100.00% specificity, 46/49 samples detected Plasmodium by nested PCR, with sensitivity of 93.88% and (12/12) specificity 100.00%; 32/46 samples were positive on serological test SD Bioline, with sensitivity of 69.56% and (10/10) 100.00% specificity. In tests with pooled samples, 13 pools (86.66%) were positive by real time PCR; the nested PCR also had positive results in the same 13 pools (86.66%). Immunochromatographic test SD Bioline Pf/Pv showed sensitivity of 73.33% compared with blood smear. Both real-time PCR and the nested PCR showed good sensitivity and specificity in samples analyzed individually and in pools, unlike the SD Bioline test. Both molecular methods showed similar performance, with good results in accuracy and validity indicators, such as sensitivity, specificity, positive and negative predictive values. Considering the advantages inherent in real-time PCR, a fast test that is processed in closed systems without post-amplification handling, this method should be indicated as first choice for diagnosis of malaria in large numbers of samples, followed by nested PCR for species determination. Serological test, that is specific for antibodies against P. vivax and P. falciparum, could be used as a supplementary method for diagnosis of malaria

Made available in DSpace on 2014-06-11T19:27:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-16Bitstream added on 2014-06-13T18:31:22Z : No. of bitstreams: 1 carvalho_db_me_sjrp.pdf: 1649413 bytes, checksum: 0ac4714a8b68e2f57418348441007ee7 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O sistema sangüíneo ABO (sABO) é o mais importante sistema na compatibilidade de grupos sangüíneos. Muitas pesquisas têm mostrado associações deste sistema com várias doenças infecciosas, inclusive a malária. Este estudo avaliou a associação entre os genótipos do sistema histo-sangüíneo ABO e a malária não grave causada pelo Plasmodium falciparum. A genotipagem dos grupos sangüíneos do sistema ABO foi feita de acordo com o protocolo de PCR/ RFLP, em amostras de indivíduos maláricos e não maláricos de áreas da Amazônia brasileira. O genótipo homozigoto ABO*O01O01 foi prevalente tanto nos maláricos quanto nos doadores de sangue. O genótipo ABO*AB representou cerca de 3% da população infectada e 5% da não infectada. Não foram verificadas diferenças estatisticamente significantes na comparação das freqüências alélicas e genotípicas do sABO entre pacientes e grupo controle, mesmo quando foram analisados apenas indivíduos com infecções puras de P. falciparum. A freqüência do sABO na Amazônia brasileira pode estar relacionada com a baixa freqüência de malária grave pelo P. falciparum. Portanto, os genótipos encontrados no sistema ABO dos indivíduos maláricos e não maláricos pode promover relevantes informações, para o entendimento da epidemiologia da malária grave por P. falciparum na Amazônia brasileira. / The ABO blood system (sABO) is the most important system on the blood groups compatibility. Several studies have shown its associations with various infectious diseases, including malaria. This study evaluated the association between the ABO histo-blood genotypes and non-severe malaria caused by Plasmodium falciparum. PCR/RFLP protocol had be used for both ABO blood group system genotyping in malaria suffering individuals and blood donors, from malaria areas of the Brazilian Amazon. The homozygous genotype ABO*O01O01 was prevalent in both malaria and the blood donors. The genotype ABO*AB represented about 3% of the infected population and 5% of non-infected. No statistically significant differences were observed in sABO genotypic and allelic frequencies of patients and the control group, even when individuals were analyzed only with pure infection of P. falciparum. The frequency of sABO in the Brazilian Amazon may be related to the low frequency of non-severe malaria P. falciparum. Therefore, the genotypes found in the ABO blood system in malaric and non-malaric individuals can promote relevant information for the understanding of the severe malaria by P. falciparum epidemiology in the Brazilian Amazon. Keywords: Malaria; ABO blood group system; Plasmodium falciparum.

Made available in DSpace on 2014-12-17T14:10:19Z (GMT). No. of bitstreams: 1 MagalyLM.pdf: 1867638 bytes, checksum: 80b497f52832062348a84e06f5fb5e32 (MD5) Previous issue date: 2009-05-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Malaria, also popularly known as maleita , intermittent fever, paludism, impaludism, third fever or fourth fever, is an acute infectious febrile disease, which, in human beings, is caused by four species: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. Malaria, one of the main infectious diseases in the world, is the most important parasitoses, with 250 million annual cases and more than 1 million deaths per year, mainly in children younger than live years of age. The prophylactic and therapeutic arsenal against malaria is quite restricted, since all the antimalarials currently in use have some limitation. Many plant species belonging to several families have been tested in vivo, using the murine experimental model Plasmodium berghei or in vitro against P. falciparum, and this search has been directed toward plants with antithermal, antimalarial or antiinflammatory properties used in popular Brazilian bolk medicine. Studies assessing the biological activity of medicinal plant essential oils have revealed activities of interest, such as insecticidal, spasmolytic and antiplasmodic action. It has also been scientifically established that around 60% of essential oils have antifungal properties and that 35% exhibit antibacterial properties. In our investigation, essential oils were obtained from the species Vanillosmopsis arborea, Lippia sidoides and Croton zethneri which are found in the bioregion of Araripe-Cear?. The chemical composition of these essential oils was partially characterized and the presence of monoterpenes and sesquiterpenes. The acute toxicity of these oils was assessed in healthy mice at different doses applied on a single day and on four consecutive days, and in vitro cytotoxicity in HeLa and Raw cell lines was determined at different concentrations. The in vivo tests obtained lethal dose values of 7,1 mg/Kg (doses administered on a single day) and 1,8 mg/Kg (doses administered over four days) for 50% of the animals. In the in vitro tests, the inhibitory concentration for 50% of cell growth in Hela cell lines was 588 μg/mL (essential oil from C. zethneri after 48 h), from 340-555 μg/mL (essential oil from L. sidoides, after 24 and 48 h). The essential oil from V. arborea showed no cytotoxicity and none of the essential oils were cytotoxic in Raw cell lines. These data suggest a moderate toxicity in the essential XVIII oils under study, a finding that does not impede their testing in in vivo antimalarial assays. Was shown the antimalarial activity of the essential oils in mice infected with P. berghei was assessed. The three species showed antimalarial activity from 36%-57% for the essential oil from the stem of V. arborea; from 32%-82% for the essential oil from the leaves of L. sidoides and from 40%-70% of reduction for the essential oil from the leaves of C. zethneri. This is the first study showing evidence of antimalarial activity with these species from northeast Brazil. Further studies to isolate the active ingredients of these oils are needed to determine if a single active ingredient accounts for the antimalarial activity or if a complex integration of all the compounds present occurs, a situation reflected in their biological activity / A mal?ria, tamb?m conhecida popularmente como maleita, febre intermitente, paludismo, impaludismo, febre ter?? ou febre quart?, ? uma doen?a infecciosa febril aguda e, em seres humanos, ? causada por quatro esp?cies de plasm?dios: Plasmodium falciparum, P. vivax, P. malariae e P. ovale. A mal?ria permanece como uma das principais doen?as infecciosas no mundo, sendo a mais importante parasitose, com 250 milh?es de casos anuais e mais de 1 milh?o de mortes por ano, principalmente em crian?as menores de cinco anos. O arsenal profil?tico e terap?utico contra a mal?ria est? bastante restrito, pois todos os antimal?ricos em uso atualmente apresentam alguma limita??o. Muitas esp?cies vegetais pertencentes a v?rias fam?lias foram testadas in vivo usando o modelo experimental murino Plasmodium berghei ou in vitro contra o P. falciparum, e essa busca tem sido orientada para plantas usadas no folclore popular brasileiro como antit?rmicas e/ou antimal?ricas ou com atividade antiinflamat?ria. Estudos sobre a avalia??o da atividade biol?gica dos ?leos essenciais de plantas medicinais t?m revelado atividades de interesse, como a??o inseticida, espasmol?tica e antiplasm?dica. Tem sido ainda, estabelecido cientificamente que cerca de 60% dos ?leos essenciais possuem propriedades antif?ngicas e 35% exibem propriedades antibacterianas. Na presente investiga??o, os ?leos essenciais foram obtidos de Vanillosmopsis arborea (Asteraceae), Lippia sidoides (Verbenaceae) e Croton zethneri (Euphorbiaceae), encontradas na biorregi?o do Araripe-Cear?. A composi??o qu?mica dos ?leos essenciais foi parcialmente caracterizada e revelou a presen?a de monoterpenos e sesquiterpenos. Avaliou-se a toxicidade aguda destes ?leos em camundongos sadios, em diferentes doses aplicadas em um ?nico dia e, em quatro dias consecutivos, como tamb?m, verificou-se a citotoxicidade in vitro em duas linhagens de c?lulas: HeLa e Raw, em diferentes concentra??es. Atrav?s dos ensaios in vivo foi poss?vel obter valores de dose letal de 7,1 mg/Kg (doses administradas em ?nico dia) e de 1,8 mg/Kg (doses administradas por quatro dias). Nos ensaios in vitro, a concentra??o inibit?ria para 50% do crescimento celular em linhagens de c?lulas HeLa foi de 588 μg/mL (?leo essencial de C. zethneri ap?s 48 h), de 340 555 μg/mL (?leo essencial de L. sidoides, ap?s 24 e 48 h). O ?leo essencial de V. XVI arborea n?o apresentou citotoxicidade. Todos os ?leos essenciais n?o foram citot?xicos em linhagens de c?lulas Raw. Estes dados obtidos sugerem uma moderada toxicidade dos ?leos essenciais em estudo, que n?o os impossibilitam a test?-los em ensaios antimal?ricos in vivo. Avaliou-se a atividade antimal?rica dos ?leos essenciais em camundongos infectados com P. berghei. Os ensaios foram realizados em diferentes experimentos. As tr?s esp?cies apresentaram atividade antimal?rica de 36 - 57% para o ?leo essencial do caule de V. arborea; de 32 - 82% para o ?leo essencial das folhas de L. sidoides e de 40 - 70% de redu??o para o ?leo essencial das folhas de C. zethneri. Este ? o primeiro estudo de evid?ncia de atividade antimal?rica com essas esp?cies no nordeste brasileiro. Estudos posteriores para isolamento dos princ?pios ativos destes ?leos s?o necess?rios para constatar se um ?nico princ?pio ativo ? o respons?vel pela atividade antimal?rica ou se ocorre intera??o complexa de todos os compostos presentes, refletindo em sua atividade biol?gica

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas Gerais / A malária é um grave problema de saúde pública. Os medicamentos de escolha para tratar a doença são as terapias baseadas em combinações de artemisininas. Porém, uma crescente resistência à estas drogas tem sido reportada. A presente investigação teve como objetivo avaliar o papel do extrato etanólico bruto de Trichoderma stromaticum (Ext-Ts) em camundongos C57BL/6 infectados com Plasmodium berghei ANKA, um conhecido modelo experimental de malária cerebral experimental. Foram monitoradas as manifestações clinicas, histológicas, imunológicas e bioquímicas características da infecção. Observou-se que o tratamento com Ext-Ts foi capaz de prevenir as alterações neurológicas associadas à malária cerebral experimental, diminuir os níveis de parasitemia e aumentar significativamente a sobrevivência de animais infectados. Além disso, foi observado que em camundongos tratados com Ext-Ts houve diminuição dos níveis de colesterol total, triglicerídeos e TGP no soro, menor deposição de hemozoína no fígado, atenuação da intensidade do edema pulmonar, proteção da integridade da barreira hematoencefálica, assim como menor citoaderência e achados histopatológicos nos tecidos avaliados, quando comparado com camundongos infectados não tratados. Esta proteção foi associada com uma diminuição na expressão de IFN-γ e ICAM-1 no cérebro dos animais tratados em relação a animais não tratados. Estes resultados sugerem que o Ext-Ts é uma potencial fonte de compostos antimaláricos e/ou imunomoduladores que poderiam melhorar o tratamento atual no contexto do aumento da resistência aos derivados da artemisinina. / Malaria is a severe health problem. The first-line treatment against the disease are the artemisinin-based combination therapies. However, increased resistance to these drugs has been reported. The aim of this study was to evaluate the role of crude etanolic extracts of Trichoderma stromaticum (Ext-Ts) in C57BL/6 mice infected with Plasmodium berghei ANKA, a well-known model of experimental cerebral malaria. Clinical, histological, immunological and biochemical features of the infection were monitored. It was found that Ext-Ts treatment was able to prevent neurological alterations associated with experimental cerebral malaria, decreased parasitemia levels and significantly improved survival of infected animals. Furthermore, it was observed that in Ext-Ts-treated mice a reduction of total serum cholesterol, triglycerides and TGP, lower hemozoin deposition into the liver, attenuation of pulmonary edema intensity, integrity of the blood-brain barrier as well as fewer cytoadherence and histopathological findings in assessed tissues in comparison with untreated infected mice. This protection was associated with decreased IFN-γ and ICAM-1 mRNA expression in brain of treated animals compared with untreated animals. These results suggest that Ext-Ts is a potential source of antimalarial and immunomodulatory compounds that could improve the current treatment in the context of resistance to artemisinin derivatives. / Dissertação (Mestrado)