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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.
201

Molecular studies using amastigote-specific genes in Leishmania

Ghedin, Elodie. January 1997 (has links)
No description available.
202

Study of the secretome of leishmania involved in the infection

Moreira Santarém, Nuno 18 April 2018 (has links)
Les parasites protozoaires du genre Leishmania sont les agents microbiens responsables d’un groupe de maladies connues sous le nom de leishmanioses. L’infection productive dépend de la capacité de survie du parasite suite au premier contact initial du système immunitaire de l’hôte. Par conséquent, la prolifération du parasite à l’intérieur des phagolysosomes sera responsable de la pathologie. Les promastigotes stationnaires, récupérés en culture axénique de laboratoire sont semblables aux promastigotes métacycliques. Ces derniers sont fortement immunomodulateurs et sont considérés, traditionnellement comme la forme la plus infectieuse du parasite. Les protéines sécrétées de différents organismes ont été directement impliquées dans plusieurs pathologies. Donc, il est possible que les protéines sécrétées par Leishmania, soient également impliquées dans la capacité du parasite à subvertir le système immunitaire. Les avancées récentes dans l’étude du sécrétome de plusieurs types de Leishmania ont permis d’affirmer que le sécrétome est fort complexe. Nous avons déterminé qu’environ 300 protéines sont sécrétées par le parasite, la plupart d’entre elles ayant aucun signal canonique de sécrétion. Le sécrétome de Leishmania est donc composé surtout de protéines qui sont libérées par sécrétion non conventionnelle, . Afin d’étudier le sécrétome associé à la virulence, nous avons développé et validé une approche qui a permis l’étude des composants de l’exoprotéome des parasites stationnaires et logarithmiques. Cette approche était basée sur la culture continue des parasites dans un milieu de culture sans supplément de sérum de bovin fœtal, cRPMI, dans lequel la virulence des parasites est maintenue. Grâce à cette approche nous avons mis en évidence un exoproteome distinct de ceux jusqu’à date répertorié. La méthode de production et de la récupération de l’exoproteome sont donc très importants. Notre exoprotéome est dominé par la GP63, une glycoprotéine dont l’importance centrale dans l’infection a été déjà validée. La culture continue des parasites est donc essentiel pour avoir un exoprotéome représentatif. Nous avons également déterminé que la cultutre en continu pouvait amener à une diminution de la virulence et quarante divisions sont nécessaires pour une perte de virulence significative. Par conséquent toutes nos études se sont fait chez des parasites comptant moins de 20 divisions. Le principal mécanisme associé à la perte de virulence a été identifié comme une incapacité de se différencier en amastigotes. Le cRPMI a donc permis la culture des parasites pour l’étude de l’exoprotéome tout en maintenant la virulence des parasites. La présence de vésicules, décrite déjà comme un composant de l’ exoprotéome, a été confirmée aussi par notre approche continue et a été confirmé, d’ailleurs, dans l’exoproteome des parasites en phase de croissance logarithmique. Les vésicules récupérées des parasites logarithmiques diffèrent de celles recueillies de parasites en phase stationnaire de croissance. En effet des protéines potentiellement impliquées dans la rénovation et le recyclage du contenu protéique, tels certains composants du ribosome étaient enrichies dans les parasites en phase logarithmique tandis que les vésicules des parasites stationnaires ont un contenu protéomique ayant des caractéristiques similaires aux corps apoptotiques des cellules de mammifères. En dehors de la GP63, plusieurs autres protéines décrites comme immunomodulatrices ont été retrouvées dans l’exoprotéome des parasites stationnaires, ce qui indique que celui-ci contient un ensemble de protéines avec un potentiel d’interaction directe avec les cellules du système immunitaire. Immunologiquement, l’exoprotéome récupéré des parasites stationnaires a été capable d’activer les cellules dendritiques, laissant supposer une fonction importante dans la création d’un environnement inflammatoire précoce lors des premières étapes de l’infection. En conclusion, la recherche développée a contribué à l’avancement des connaissances actuelles sur la biologie du Leishmania, grâce au développement et à la validation d’une nouvelle approche afin d’étudier son exoprotéome. L’exoprotéome récupéré était dynamique, il avait une composition spécifique, dépendant du stade du parasite. Cet exoprotéome avait des effets spécifiques sur les cellules dendritiques et il jouait un rôle important dans les étapes précoces de l’infection. Cette étude a ouvert des nouvelles perspectives sur l’exoprotéome de Leishmania spp. permettant la découverte de nouvelles protéines immunomodulatrices et, en corrolaire, de nouvelles cibles pour le contrôle de la maladie associée au parasite. / Protozoa parasites of the genus Leishmania are the responsible for a group of diseases known as leishmaniasis. The infection is associated with the capacity of these parasites to survive in the phagolysosomes of infected macrophages. Successful infections with pathogenic Leishmania spp. are linked to the capacity of the parasite to survive the initial impact of the host immune system and to interfere with the infected cells rendering them incapable of eliminating the parasites. The secreted proteins from the parasite are expected to be in the front line for interactions with the host. Recent advances in the study of the secretome of Leishmania spp. depicted it as highly complex with the majority of proteins without any predictable secretion signal. The secretome is composed of proteins that are released by different mechanisms like conventional and unconventional secretion. Several proteins secreted by Leishmania spp. are known to interact and influence the outcome of the disease by directly interfering with the host immune cells. The proteomic studies on the Leishmania spp. secretome identified more than three hundred proteins released into the exterior. The stationary promastigotes recovered in axenic culture were enriched in the most virulent promastigote form, the metacyclic parasites. Therefore we aimed at evaluating the exoproteome associated with the stationary parasites. To achieve this we developed and validated an approach that would enable the study of the exoproteome components of stationary and logarithmic parasites. This approach was based on the continuous cultivation of the parasites in a medium without any protein supplementation that maintained the basic virulence of the parasites. The continuous approach produced a GP63-rich exoproteome that was distinct from the traditional approaches indicating that the process of recovery induced a significant bias in the study. Furthermore as the continuous approach was chosen, we determined the mechanisms associated with loss of virulence assuring that fully virulent parasites were used. At least forty parasite divisions were required for a short-term loss of virulence. The main mechanism associated with loss of virulence was identified as a growing incapacity to differentiate into amastigotes. The defined time interval of forty divisions enabled us to evaluate the exoproteome without loss of virulence related to the subculture. The protein-free medium developed, cRPMI, retained parasite virulence and morphology similar to that of parasites grown in standard media. The exoproteomes recovered using cRPMI were dominated by proteins without any recognizable secretion sequence, in concordance with reports on other Leishmania spp. The presence of vesicles, already reported as a component of the exoproteome, was also confirmed using our continuous approach. Furthermore, the presence of vesicles in the logarithmic parasites exoproteome was confirmed. The protein content of these vesicles presented a dynamic profile that was dependent on the parasite stage. The vesicles recovered from logarithmic parasites seemed to be related to protein turnover, being significantly enriched in ribosomal components. The vesicles from stationary parasites are of different composition, presenting some characteristics similar to apoptotic bodies. Immunologically the exoproteome recovered from stationary parasites was able to activate dendritic cells suggesting that the exoproteome might have a function in the creation of an early inflammatory environment leading to the recruitment of neutrophils and monocytes that might function as safe heavens for the parasites. In conclusion, our research has contributed to the advance of the current knowledge of Leishmania biology, through the development and validation of a novel approach to study the Leishmania secretome. The exoproteome recovered from stationary parasites had specific immune-modulating effects on bone marrow derived dendritic cells, indicating that it can play an important role in the precocious steps of infection. This study opened new perspectives into the Leishmania spp. exoproteome that will enable the search of new immunomodulatory proteins that might become the future targets to leishmaniasis control.
203

Implication des Galectines-3, 7 et 9 dans la réponse immunitaire contre le parasite Leishmania major

St-Pierre, Guillaume 19 April 2018 (has links)
La galectine-3, une protéine cytosolique de l’hôte est impliquée dans la réponse immunitaire contre Leishmania major, un parasite protozoaire causant une infection cutanée. Lors d’une infection avec la souche LV39 de L. major, la galectine-3 se libère dans le milieu extracellulaire et participe au recrutement de neutrophiles au site d’infection. La galectine-3 ne semble cependant pas impliquée lors d’infections avec la souche L. major Friedlin qui possède un arrangement de saccarides différent sur ses phosphoglycans. In vitro, les deux souches de L. major sont en mesure de cliver la galectine-3, mais LV39 semble plus efficace. Différents essais ont été effectués in vivo afin de vérifier si les galectines-7 et 9 peuvent aussi avoir un rôle à jouer lors d’infection avec L. major. Alors qu’aucun effet significatif n’a pu être attribué à la galectine-9, l’absence de galectine-7 semble apporter une guérison plus rapide des lésions engendrées par L. major Friedlin. / Our recent data suggest that galectin-3, a host cytosolic protein is involved in the immune response against the Leishmania major strain LV39, which induces cutaneous infection. Following infection with this parasite, galectin-3 is released in the extracellular space and plays a role in neutrophil recruitment. In contrast, in another L. major strain called Friedlin, which expresses a different glycan structure on the phosphoglycans, galectin-3 has no impact on the host immune response and disease outcome. Our laboratory previously reported that L. major LV39 cleaves galectin-3. Our data suggest that both L. major strains are able to cleave galectin-3 in vivo, although the cleavage by LV39 is more efficient than that by Friedlin. We also addressed the role of galectins-7 and 9 in a murine L. major infection model. Lack of galectin-9 did not alter the pathogenesis of Leishmania infection. In contrast, lack of galectin-7 contributed to improve healing process.
204

Mechanistic insights of SIDER2 retroposon-mediated mRNA decay in Leishmania

Azizi, Hiva 24 April 2018 (has links)
Leishmania est un pathogène important pour la santé humaine avec plus de 350 millions de personnes à risque dans le monde. Leishmania présente des caractéristiques uniques en termes de régulation génique constituant ainsi un excellent modèle pour l’étude des mécanismes de régulation génique. Chez Leishmania ainsi que les autres Trypanosomatidae, il n’y a pas de controle au niveau de l’initiation de la transcriptin et la regulation se fait pas presque exclusivement au niveau post-transcriptionnel. Les éléments régulateurs en cis situés dans les régions 3' non-traduites (3'UTRs) des ARN messagers chez Leishmania (ARNms) sont essentiels pour la régulation de la stabilité ou la traduction des transcrits. Malgré les efforts considérables déployés pour l’identification de ces éléments régulateurs, uniquement quelques centaines ont été caractérisées chez les eucaryotes. Nous avons identifiés une nouvelle classe de rétroéléments agissant en cis, appelés SIDERs (Short Interspersed DEgenerate Retroposons) qui sont largement distribués dans le génome du parasite (>2000 copies de SIDER1 et SIDER2), situés pour la plupart dans la région 3ʹUTR. Les transcrits contenant SIDER2 le région 3ʹUTR sont dégradés par un mécanisme indépendant de la déadénylation initié par un clivage endonucléolytique au sein de la séquence signature II (SII) qui est conservée parmi SIDER2. Mon travail a consisté à déterminer les séquences nécessaires pour le clivage endonucléolytique et à identifier les trans-régulateurs jouant un rôle dans la dégradation des ARNm dépendante de SIDER2. Nous avons adopté une approche de purification d'affinité d'ARN étiquetés MS2 permettant de capturer les facteurs trans-régulateurs. Parmi ces éléments liant spécifiquement SIDER2, la Pumilio protéine PUF6 est responsable de la dégradation du transcrit rapporteur possédant la séquence SIDER2 en 3ʹUTR. De plus, l’inactivation du gène PUF6 se manifeste par une augmentation de stabilité des transcrits, suggérant un rôle de PUF6 dans la dégradation des ARNm médiée par SIDER2. Des études de mutations au sein de la séquence conservée, signature II, responsable de la régulation de la dégradation, ont permis de souligner l’importance de sites de clivages putatifs, précédemment identifiés au niveau de SIDER2. De plus, deux régions additionnelles proches de l’extrémité terminale de la séquence SIDER2 se sont révélées de jouer aussi un rôle au niveau de la déstabilisation de l’ARNm. Enfin, nous avons investigué le rôle de la traduction au niveau de la dégradation des ARNm médiée par SIDER2 et nous avons montré que la dégradation des transcrits SIDER2 est liée à une traduction active, soulignant ainsi l’importance de la machinerie de la traduction au niveau de la régulation globale des transcrits contenants des éléments SIDER2 dans le 3’UTR.. / Leishmania spp. are important human pathogens which put lives of over 350 million people at risk, worldwide. Apart from being an important human pathogen, Leishmania has unique features in terms of gene regulation, rendering it an excellent model organism to study gene regulation mechanisms. Notably, Leishmania and other trypanosomatids lack control at the level of transcription initiation and therefore most of the regulation of gene expression takes place post-transcriptionally. Cis-acting elements in 3ʹ-untranslated regions (3ʹUTRs) of Leishmania messenger RNAs (mRNAs) are central to the regulation of mRNA decay or translation efficiency. We have identified a novel class of cis-acting retroposons, termed SIDERs (Short Interspersed DEgenerate Retroposons) that are widely distributed in the parasite genome (>2000 copies of SIDER1 and SIDER2), mostly within 3ʹUTRs. Transcripts bearing SIDER2 in their 3ʹUTR are degraded via a deadenylation-independent pathway involving endonucleolytic cleavage within the conserved signature II (SII) sequence of SIDER2 elements. My research project aimed at determining the sequence requirements for endonucleolytic cleavage and identifying the trans-acting factor(s) contributing to SIDER2-mediated mRNA decay. We employed a tethering approach using the MS2 system to capture the trans-acting proteins in vivo. Amongst the proteins specifically tethered to SIDER2, the Pumilio protein PUF6 was shown to downregulate the SIDER2-harboring reporter transcript. Furthermore, inactivation of the PUF6 gene resulted in upregulation and increased transcript stability, indicating that PUF6 contributes to SIDER2-mediated decay. Mutational analysis within the conserved SII region, known to regulate decay, highlighted the importance of the previously mapped putative cleavage sites in mediating degradation of SIDER2-containing transcripts. Furthermore, two additional regions closer to the end of the SIDER2 sequence were found to contribute to mRNA destabilization. Finally, we addressed the requirement of translation for SIDER2 mediated decay and showed that degradation of SIDER2 transcripts is linked to ongoing translation, underscoring significance of the translation apparatus in global regulation of SIDER2-containing transcripts.
205

Estudo da correlação entre entre a carga parasitária de cães com diferentes apresentações clínicas da Leishmaniose Visceral e a transmissão ao vetor da Leishmania infantum

Borja, Lairton Souza January 2013 (has links)
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2013-11-07T16:33:35Z No. of bitstreams: 1 Lairton Souza Borja Estudo da Correlação entre a carga parasitária de cães com diferentes...pdf: 1237856 bytes, checksum: 9bc0086e1a2811c6ba645a2fc3b31e9f (MD5) / Made available in DSpace on 2013-11-07T16:33:35Z (GMT). No. of bitstreams: 1 Lairton Souza Borja Estudo da Correlação entre a carga parasitária de cães com diferentes...pdf: 1237856 bytes, checksum: 9bc0086e1a2811c6ba645a2fc3b31e9f (MD5) Previous issue date: 2013 / Universidade Federal da Bahia. Faculdade de Medicina da Bahia. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil. / No Novo Mundo, a leishmaniose visceral (LV) é causada pela Leishmania infantum, que tem como vetor o inseto flebotomíneo Lutzomyia longipalpis. Os cães são considerados o principal reservatório urbano da infecção. Devido ao fato do controle da LV se basear, principalmente, no controle da leishmaniose visceral canina (LVC), é importante estudar o papel dos cães na transmissão da infecção. Foi demonstrado que cães apresentando diferentes apresentações clínicas da LV, inclusive os assintomáticos transmitem a infecção ao vetor flebotomíneo. Nenhum estudo sistemático avaliou a associação direta entre a carga parasitária em diferentes tecidos e a transmissão do parasito. A hipótese desse estudo é que cães com baixa carga parasitária na pele e no sangue não transmitem a infecção ao vetor flebotomíneo. O objetivo deste estudo foi analisar se há correlação entre a carga parasitária de cães com diferentes apresentações clínicas da LV e a transmissão ao vetor Lutzomyia longipalpis. Foram selecionados 35 cães de dois canis, locazidos em area endêmica (n=23) e não endêmica (n=12) para LV. Os animais foram classificados de acordo com o número de sinais clínicos em: assintomáticos (sem sinais; n=12), oligossintomáticos (1-3 sinais; n=15) e polissintomático (<3 sinais; n =8). Todos os 35 cães foram positivos em pelo menos um dos testes diagnósticos: ELISA (n=8), cultura de aspirado esplênico (n=9) e qPCR (n=35) dos tecidos avaliados. Diferentes tecidos (sangue periférico, aspirado esplênico e biópsia de pele) foram coletados para quantificação do DNA do parasito pela qPCR. Para avaliar a capacidade de transmissão dos cães, foi realizado xenodiagnóstico, seguido de determinação da carga parasitária em cada flebótomo utilizando qPCR. Finalmente, a capacidade de transmissão de Leishmania foi estimada pela determinação, após o xenodiagnóstico, da infectividade de cães ao flebótomo, da taxa de infecção de flebótomos, e da carga parasitária transmitida aos flebótomos. Baixa carga parasitária na pele e no sangue foi detectada em aproximadamente 85% dos cães assintomáticos. A infectividade de cães ao flebótomo variou de 60 a 90%, e foi similar entre animais apresentando diferentes números de sinais clínicos. Foi identificado que o maior percentual (51%) de cães transmite parasitos a um pequeno número de flebótomos (de 1 a 5 em 30 flebótomos utilizados no xenodiagnóstico). Entre os tecidos analisados, correlação positiva foi detectada entre a infectividade de cães ao vetor e a carga parasitária nas amostras de sangue (r = 0.50, p<0.01). Adicionalmente, foi observada, correlação positiva entre menor taxa de infecção dos flebótomos e baixa carga parasitária no sangue (r = 0.53, p<0.01). Em conjunto, estes dados mostram que cães com baixa carga parasitária são capazes de transmitir o parasito, porém a um pequeno número de flebótomos e com uma baixa carga parasitária. / In the New World, visceral leishmaniasis (VL) is caused by Leishmania infantum and is usually transmitted by Lutzomyia longipalpis. Dogs are considered the main urban reservoir of the parasite. Evaluation of the importance of dogs in Leishmania transmission in VL is well established. Dogs with different clinical forms of VL have shown to transmit the infection to the sandfly vector, even those with no clinical signs of the disease. Comprehensive studies that correlate transmission and parasite load in different tissues are scarce. Our hypothesis is that dogs with low parasite load in the skin and blood do not transmit the infection to the sandfly vector. We aimed to analyze the correlation between parasite load of dogs with different clinical forms of CVL and transmission to the vector Lutzomyia longipalpis. Thirty five dogs were selected from two canine kennels, located in an endemic (n=23) and non-endemic area (n=12) for VL. These animals were classified according to the clinical signs into asymptomatic (no signs; n=12), olygosymptomatic (1-3 signs; n=15) and polysymptomatic (>3 signs; n=8). All the 35 dogs tested positive for at least one of the diagnostic tests: ELISA (n=8), culture in splenic aspirates (n=9) and qPCR for Leishmania DNA detection (n=35). Different tissues (blood, splenic aspirate and skin biopsy) were collected for quantification of parasite load using qPCR. To evaluate the infectivity of the dogs to vector, first we performed the xenodiagnosis, then we quantified parasite load in each sandfly using qPCR. Finally, transmission of Leishmania was estimated by determining infectivity to sandflies, and the infection rate, and the parasite load transmitted to sandflies. Low parasite load in the skin and blood was detected in approximately 85% of asymptomatic dogs. Infectivity to sandflies varied from 60 to 90%, and shown to be similar among animals presenting different number of clinical signs. It was noted that the highest percentage (51%) of dogs transmitted infection to a small number of sandflies (from 1 to 5 in 30 sandflies used in xenodiagnosis). Positive correlation between infectivity to sandflies and parasite load was only detected in blood among the tissues analyzed (r = 0.50, p <0.01). Additionally, a lower parasite load in blood (r = 0.53, p <0.01) were correlated to the presence of lower number of positive sandflies in xenodiagnosis. These findings indicate that animals with low parasite load are capable to transmit Leishmania to sandflies, although to a lower number of sandflies and with a low parasite load.
206

Avaliação in vitro da atividade anti-leishmania induzida por complexos metálicos a base de prata

Soldera, Pauline de Faria 11 July 2015 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-06T13:53:11Z No. of bitstreams: 1 Dissertação Parcial - Pauline Soldera.pdf: 748540 bytes, checksum: 966764b9bef7541de4b3724ad90c77a6 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-06T13:53:35Z (GMT) No. of bitstreams: 1 Dissertação Parcial - Pauline Soldera.pdf: 748540 bytes, checksum: 966764b9bef7541de4b3724ad90c77a6 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-06T13:53:49Z (GMT) No. of bitstreams: 1 Dissertação Parcial - Pauline Soldera.pdf: 748540 bytes, checksum: 966764b9bef7541de4b3724ad90c77a6 (MD5) / Made available in DSpace on 2016-12-06T13:53:49Z (GMT). No. of bitstreams: 1 Dissertação Parcial - Pauline Soldera.pdf: 748540 bytes, checksum: 966764b9bef7541de4b3724ad90c77a6 (MD5) Previous issue date: 2015-07-11 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Leishmaniasis is an infectious disease - parasitic caused by a parasite of the genus Leishmania and transmitted by the bite of infected female sandfly. Human infections caused by Leishmania can manifest in different ways, depending on the causal species, such as cutaneous leishmaniasis (CL) or visceral leishmaniasis (VL). The therapeutic arsenal against LT is still very restricted. The pentavalent antimony remain the drugs of choice for the treatment and, despite its efficacy, have side effects with prolonged treatment time. Medicinal Chemistry Inorganic have offered new possibilities for research, and metals, especially transition, offer some advantages over drugs, including the variety of oxidation states, enabling their participation in redox biological processes. In the present work we studied the in vitro effect of two metal complexes silver base (Ag1 and Ag2), against promastigotes and amastigotes of Leishmania. (Leishmania) amazonensis and Leishmania. (Viannia) guyanensis in periods of 24, 48 and 72 hours. The metal complexes were synthesized by the team of "Istituto per l'Energetica and le Interfasi" IENI, Padua, Italy (CNR, National Research Council, IT) and sent to biological testing at the National Institute for Amazonian Research (INPA). Results of bioassays with L. (L.) amazonensis showed that Ag2 substance showed higher anti-leishmania activity in the concentration of 160μM/ml, from 72h, EC50 14.53 uM/ml in the manual counting method, and by the MTT method at 24 hours period with EC50 11.35 uM/mL. In cons tests the amastigote form, there was little infection of macrophages by Ag1 complex, 25% infected, compared with 61% without infection amastigotes. Results with L. (V.) guyanensis, the manual counting method, Ag1 did not show satisfactory values, with EC50> 60 uM / ml, Ag2 showed moderate activity in the period of 24h and 48h, EC50 43.22 uM / ml and 57, 64 uM / ml. For the MTT the two substances had EC50 values> 60 uM / ml. Against amastigote forms, with Ag1 complex was cell death of the macrophages. Ag2 showed 38% infection rate, with 47% of uninfected macrophages. Thus, the two metal complexes did not perform well when tested across the promastigote and amastigote forms of L. (V.) guyanensis. Against forms L. (L.) amazonensis, both complexes showed satisfactory results, and the Ag2 complex, with better results in promastigote and amastigote forms / A leishmaniose é uma doença infecto – parasitária causada por um parasita do gênero Leishmania e transmitida pela picada do flebotomíneo fêmea infectado. Infecções humanas causadas pela Leishmania podem manifestar-se de diferentes formas, dependendo da espécie causal, como leishmaniose tegumentar (LT) ou leishmaniose visceral (LV). O arsenal terapêutico contra a LT ainda é muito restrito. Os antimoniais pentavalentes permanecem como as drogas de primeira escolha para o tratamento e, apesar de sua eficácia, apresentam efeitos colaterais, com tempo de tratamento prolongado. A Química Inorgânica Medicinal têm oferecido novas possibilidades para a pesquisa, e os metais, em especial os de transição, oferecem algumas vantagens sobre os fármacos, incluindo a variedade de estados de oxidação, permitindo sua participação em processos biológicos redox. No presente trabalho foi estudado o efeito in vitro de dois complexos metálicos a base de prata (Ag1 e Ag2), contra as formas promastigotas e amastigotas de Leishmania. (Leishmania) amazonensis e Leishmania. (Viannia) guyanensis nos períodos de 24, 48 e 72 horas. Os complexos metálicos foram sintetizados pela equipe do “Instituto per l’Energetica e le Interfasi”, IENI, Pádua, Itália(CNR, Conselho Nacional de Pesquisas, IT) e encaminhados para testes biológicos no Instituto Nacional de Pesquisas da Amazônia (INPA). Resultados dos bioensaios com L. (L.) amazonensis demonstraram que a substância Ag2 apresentou maior atividade anti-leishmania na concentração de 160μM/mL, no período de 72h, EC50 14,53 μM/mL no método de contagem manual, e pelo no método MTT, no período de 24h, com EC50 11,35 μM/mL. Nos testes contras as forma amastigota, houve pouca infecção de macrófagos pelo complexo Ag1, 25% infectados, contra 61% sem infecção do formas amastigotas. Resultados com L. (V.) guyanensis, pelo método de contagem manual, Ag1 não apresentou valores satisfatório, com do EC50 >60 μM/ mL, Ag2 apresentou atividade moderada nos período de 24h e 48h, EC50 43,22 μM/ mL e 57, 64 μM/ mL. Pelo método MTT as duas substâncias apresentaram valores de EC50 >60 μM/ mL. Contra as formas amastigotas, com o complexo Ag1, houve a morte celular dos macrófagos. Ag2 apresentou taxa de infecção de 38%, contra 47% de macrófagos não infectados. Sendo assim, os dois complexos metálicos não desempenharam bons resultados quando testados frente as formas promastigota e amastigota de L. (V.) guyanensis. Contra as formas de L. (L.) amazonensis, ambos complexos apresentaram resultados satisfatórios, sendo o complexo Ag2, tendo melhores resultados em formas promastigota e amastigota.
207

Análise da atividade de CD100 na modulação da ativação de macrófagos e sua infectividade por Leishmania (Leishmania) amazonensis. / Analysis of CD100 modulation of macrophage activation and infectivity by Leishmania (Leishmania) amazonensis.

Mariana Kolos Galuppo 29 June 2012 (has links)
Considerando a importância do perfil do macrófago na infecção por Leishmania e o potencial papel de CD100 na modulação da ativação do m<font face=\"Symbol\">j, postulamos que essa molécula pode afetar a infectividade dessa célula por este parasita. Portanto, analisou-se e comparou-se a expressão de CD100 em diferentes tipos de m<font face=\"Symbol\">j (BALB/c e C57BL/6) e seus efeitos em termos de ativação e infecção com L. amazonensis. Avaliamos a expressão de CD100 e observamos que m<font face=\"Symbol\">js peritoneais de BALB/c expressam mais CD100 do que os de C57BL/6 e que esta expressão diminui ao longo da infecção. M<font face=\"Symbol\">j de BALB/c pré-tratados com sCD100 antes da infecção tem maior índice no tempo de 4h e quando em contato com o sCD100 antes, durante e após a infecção, o índice aumenta em 4 e 24h. Em m<font face=\"Symbol\">j de C57BL/6 pré-tratados com sCD100 ou no período de infecção, o índice aumenta em 4h. Quando permanecem durante todo o tempo em contato com o sCD100 o índice aumenta nos períodos de 4 e 24h. Concluímos que o CD100 pode estar relacionado com a modulação da infecção, e que a infecção afeta a expressão dessa molécula pelo m<font face=\"Symbol\">j. / Considering the importance of m<font face=\"Symbol\">j in Leishmania´s infection and the potential role of CD100 in the modulation of m<font face=\"Symbol\">j activation, we postulated that this molecule may affect m<font face=\"Symbol\">j infectivity. Therefore, we analyzed and compared the expression of CD100 on different types of m<font face=\"Symbol\">j (BALB/c and C57BL/6) and their effects in terms of m<font face=\"Symbol\">j activation and infectivity by L. amazonensis. We analyzed the expression of CD100 and the results suggest that m<font face=\"Symbol\">j from BALB/c express more CD100 than C57BL/6 and this expression decrease along the infection. M<font face=\"Symbol\">j from BALB/c pre-treated with sCD100 have augmented infection rates in 4h and in contact with the sCD100 before, during and after infection, increase rates in periods of 4 and 24h. In m<font face=\"Symbol\">j from C57BL/6 pre-treated with sCD100 or infection period, the rates increase in 4h. When macrophages remained in contact with sCD100 throughout the infection, rates increase after 4 and 24h. We can therefore conclude that CD100 may be related to modulation of Leishmania´s infection and that the infection itself affects CD100 expression in m<font face=\"Symbol\">j.
208

Análise da atividade de CD100 na modulação da ativação de macrófagos e sua infectividade por Leishmania (Leishmania) amazonensis. / Analysis of CD100 modulation of macrophage activation and infectivity by Leishmania (Leishmania) amazonensis.

Galuppo, Mariana Kolos 29 June 2012 (has links)
Considerando a importância do perfil do macrófago na infecção por Leishmania e o potencial papel de CD100 na modulação da ativação do m<font face=\"Symbol\">j, postulamos que essa molécula pode afetar a infectividade dessa célula por este parasita. Portanto, analisou-se e comparou-se a expressão de CD100 em diferentes tipos de m<font face=\"Symbol\">j (BALB/c e C57BL/6) e seus efeitos em termos de ativação e infecção com L. amazonensis. Avaliamos a expressão de CD100 e observamos que m<font face=\"Symbol\">js peritoneais de BALB/c expressam mais CD100 do que os de C57BL/6 e que esta expressão diminui ao longo da infecção. M<font face=\"Symbol\">j de BALB/c pré-tratados com sCD100 antes da infecção tem maior índice no tempo de 4h e quando em contato com o sCD100 antes, durante e após a infecção, o índice aumenta em 4 e 24h. Em m<font face=\"Symbol\">j de C57BL/6 pré-tratados com sCD100 ou no período de infecção, o índice aumenta em 4h. Quando permanecem durante todo o tempo em contato com o sCD100 o índice aumenta nos períodos de 4 e 24h. Concluímos que o CD100 pode estar relacionado com a modulação da infecção, e que a infecção afeta a expressão dessa molécula pelo m<font face=\"Symbol\">j. / Considering the importance of m<font face=\"Symbol\">j in Leishmania´s infection and the potential role of CD100 in the modulation of m<font face=\"Symbol\">j activation, we postulated that this molecule may affect m<font face=\"Symbol\">j infectivity. Therefore, we analyzed and compared the expression of CD100 on different types of m<font face=\"Symbol\">j (BALB/c and C57BL/6) and their effects in terms of m<font face=\"Symbol\">j activation and infectivity by L. amazonensis. We analyzed the expression of CD100 and the results suggest that m<font face=\"Symbol\">j from BALB/c express more CD100 than C57BL/6 and this expression decrease along the infection. M<font face=\"Symbol\">j from BALB/c pre-treated with sCD100 have augmented infection rates in 4h and in contact with the sCD100 before, during and after infection, increase rates in periods of 4 and 24h. In m<font face=\"Symbol\">j from C57BL/6 pre-treated with sCD100 or infection period, the rates increase in 4h. When macrophages remained in contact with sCD100 throughout the infection, rates increase after 4 and 24h. We can therefore conclude that CD100 may be related to modulation of Leishmania´s infection and that the infection itself affects CD100 expression in m<font face=\"Symbol\">j.
209

Avaliação da especificidade do efeito da saliva do flebotomíneo vetor sobre a infectividade da espécie de Leishmania: infecção experimental de Leishmania (L.) amazonensis e Leishmania (V.) braziliensis com a saliva de Lutzomya flaviscutellata e Lutzomyia (Psychodopygus) complexus em camundongo BALB/c / Evaluation of the specificity of the effect of sand fly vector in the infectivity of Leishmania: experimental infection of Leishmania (L.) amazonensis and Leishmania (V.) braziliensis with the saliva of Lutzomyia flaviscutellata and Lutzomyia (Psychodopygus) complexus in BALB/c mice

Francesquini, Fernanda de Camargo 20 February 2014 (has links)
No ciclo natural de transmissão da leishmaniose, as fêmeas infectadas de flebotomíneos regurgitam promastigotas na pele de hospedeiro junto com a saliva. Tem sido descrito que componentes da saliva do vetor possuem propriedades imunomodulatórias que facilitam o estabelecimento da infecção no hospedeiro, contudo a maior parte dos estudos emprega lisado de glândula salivar (LGS) de vetores colonizados em laboratório. Dessa forma, o principal objetivo deste estudo foi avaliar a especificidade do LSG dos flebotomíneos Lutzomyia flaviscutellata e Lutzomyia (Psychodopygus) complexus capturados no campo na infectividade de Leishmania (Leishmania) amazonensis e Leishmania (Viannia) braziliensis. Camundongos BALB/c foram inoculados no coxim plantar traseiro com formas promastigotas de L. (L.) amazonensis e L. (V.) braziliensis na ausência ou presença do LGS de L. flaviscutelata, e L. (P.) complexus. A evolução da infecção foi acompanhada semanalmente e biópsias do ponto de inoculação foram coletadas para análise histopatológica e determinação de carga parasitária na 4ª e 8ª semana pós-infecção (PI); e o linfonodo de drenagem para caracterização de subpopulações de linfócitos T por citometria de fluxo. Células de linfonodo de drenagem foram também cultivadas, com estímulo homólogo, para quantificação de citocinas (IL-10, IL- 12 e IL-4) no sobrenadante. A infecção por L. (L.) amazonensis e L. (V.) braziliensis não se mostrou exacerbada nos grupos co-inoculados com o LGS de ambas as espécies em relação ao grupo controle, inoculado somente com o parasito. O tamanho de lesão e carga parasitária do grupo controle foi maior ou igual aos grupos com saliva. Na infecção por L. (L.) amazonensis houve diminuição dos linfócitos CD4+ e aumento na população de linfócitos CD8+ enquanto na infecção por L. (V.) braziliensis houve manutenção da população de linfócitos CD4+ e aumento de linfócitos CD8+ em todos os grupos quando comparados ao grupo saudável. A produção de IL-10 e IL-12, não diferiram entre os grupos, assim como a produção de IL-4 no grupo infectado por L. (V.) braziliensis. No entanto, nos grupos infectados apenas com L. (L.) amazonensis e com saliva de L. flaviscutellata, foi observada uma maior produção de IL-4 em relação ao grupo saudável. De forma geral, os resultados mostraram que a saliva de L. flaviscutellata e de Lutzomyia (P.) complexus, no seu binômio natural vetor/parasito ou não, não favoreceram o estabelecimento da infecção causada por L. (L.) amazonensis e L. (V.) braziliensis em camundongos BALB/c. / During the natural transmission of leishmaniasis, the infected female phlebotomine regurgitates promastigotes into the host\'s skin together with the saliva. It has been reported that components of vector saliva contain immunomodulatory properties that facilitate the establishment of infection in the host, however the most studies employed salivary gland lysate (SGL) of laboratory colonized vectors. Thus, the main objective of this study was to evaluate the specificity of SGL of the phlebotomines Lutzomyia flaviscutellata and Lutzomyia (Psychodopygus) complexus caught in the field in the infectivity of L. (L.) amazonensis and L. (V.) braziliensis. BALB/c mice were inoculated in the hind footpad with promastigotes of L. (L.) amazonensis and L. (V.) braziliensis in the absence or presence of L. flaviscutelata, and L. (P.) complexus SGL. The evolution of the lesion size was evaluated weekly and biopsies from the site of infection were collected for histopathological analysis and determination of parasite load in the 4th and 8th week post infection (PI), and the draining lymph node to characterize subsets of T cells by flow cytometry. The draining lymph nodes cells were also cultured with specific antigen to determine the cytokines (IL-10, IL-12 and IL-4) in the supernatant. L. (L.) amazonensis and L. (V.) braziliensis infection was not exacerbated in the groups co-inoculated with the SGL of both species in the control group, only inoculated with the parasite. The lesion size and parasite burden of the control group was higher or equal to the groups with saliva. In L. (L.) amazonensis infection there was a decrease of CD4+ cells and an increase in the population of CD8+ cells while in L. (V.) braziliensis infection there was a maintenance of CD4+ cells and an increase in the population of CD8+ cells in all groups compared with the health group. The production of IL-10 and IL-12, did not differ between groups, as well as the production of IL-4 in the group infected by L. (V.) braziliensis. However, in the groups infected only with L. (L.) amazonensis in the presence of L. flaviscutellata saliva, it was observed a higher production of IL-4 in relation with the health group. As a whole, the results show that the saliva of L. flaviscutellata and L. (P.) complexus, in the natural vector/parasite binomium or not, did not favor the establishment of the infection caused by L. (L.) amazonensis and L. (V.) braziliensis in BALB/c mice
210

Avaliação da susceptibilidade de Lutzomyia migonei (Diptera: Psychodidae) ao desenvolvimento de Leishmania (Leishmania) infantum / Evaluation of the susceptibility of Lutzomyia migonei (Diptera: Psychodidae) to Leishmania (Leishmania) infantum

Guimarães, Vanessa Cristina Fitipaldi Veloso January 2016 (has links)
Submitted by Stephany Silva (stephany.silva@cpqam.fiocruz.br) on 2016-09-19T12:39:49Z No. of bitstreams: 1 Tese Doutorado_Vanessa Fitipaldi final. 15.07.16pdf.pdf: 4368605 bytes, checksum: 43e7621075f176708936269193abf2d3 (MD5) / Approved for entry into archive by Adagilson Silva (adagilson@cpqam.fiocruz.br) on 2016-09-19T18:06:33Z (GMT) No. of bitstreams: 1 Tese Doutorado_Vanessa Fitipaldi final. 15.07.16pdf.pdf: 4368605 bytes, checksum: 43e7621075f176708936269193abf2d3 (MD5) / Made available in DSpace on 2016-09-19T18:06:33Z (GMT). No. of bitstreams: 1 Tese Doutorado_Vanessa Fitipaldi final. 15.07.16pdf.pdf: 4368605 bytes, checksum: 43e7621075f176708936269193abf2d3 (MD5) Previous issue date: 2016 / Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, Brasil / A oferta e uso das Práticas Integrativas e Complementares (PICs) tem aumentado no Brasil e no mundo. Dentre as que mais cresceram no Brasil estão as chamadas Práticas Corporais (PCs). Esse artigo objetivou traçar um perfil dos usuários de PCs analisando sua qualidade de vida, os aspectos sociodemográficos e de saúde e os motivos que os levaram a procurar um serviço de PICs. Se tratou de um estudo exploratório e analítico, de abordagem quantitativa. Os dados foram coletados por meio dos prontuários e da avaliação qualidade de vida pelo WHOQOL-bref de 147 usuários de práticas corporais ofertadas por uma unidade de práticas intergrativas em Recife-PE. Os resultados apontaram associações significantes entre os aspectos sócio demográficos e de saúde, a qualidade de vida e os motivos de procura dos usuários de práticas corporais pelo serviço de PICs (AU)

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