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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.
151

Epidémiologie du paludisme et environnement : étude de deux communautés amérindiennes de l'est et de l'ouest guyanais / Epidemiology of malaria and environment : study of two Amerindian populations in Eastern and Western French Guiana

Stéfani, Aurélia 14 December 2011 (has links)
Notre étude s’est proposée d’analyser l’incidence du paludisme et son évolution dans le temps et dans l’espace, ainsi que de rechercher les facteurs de risque d’accès palustres chez les enfants d’un village du Moyen-Oyapock (Camopi), peuplé d’Amérindiens wayampi et émerillon, d’une part, et d’un village du Haut-Maroni (Antecume Pata), peuplé d’Amérindiens wayana, d’autre part. L’approche a été multiple avec, pour chacun des deux sites d’étude :- Une analyse de survie (modèle de Cox) à partir des accès palustres confirmés biologiquement dans une cohorte d’enfants de moins de sept ans régulièrement suivis, ainsi qu’un questionnaire de type Connaissances, Attitudes et Pratiques (CAP), puis les caractéristiques des habitats et la description de leur environnement immédiat.- Une analyse spatiale avec une classification de l’occupation du sol à partir d’images satellites SPOT 5, l’extraction de variables environnementales d’intérêt, l’étude de leur effet sur la transmission du paludisme et la mise au point d’une méthode objective de sélection d’un rayon d’observation autour des habitations pour la caractérisation de l’environnement.- Une étude de séries temporelles (ARIMA) afin de déterminer l’effet des évènements climatiques et hydrologiques sur le paludisme, aux niveaux local et plus global (El Niño).Les taux d’incidence d’accès palustres sur la période 2001-2009 se sont révélés particulièrement élevés chez les jeunes enfants, notamment à Camopi avec une moyenne de 773‰ par année. Une diminution brutale de l’incidence a eue lieu en 2007 sur le Haut-Maroni et ce phénomène est observé à Camopi depuis 2010. Une prémunition se développe assez rapidement au cours de la vie (2-3 ans), surtout contre les reviviscences à Plasmodium vivax. Les facteurs environnementaux se sont avérés être les plus nombreux et les plus fortement liés à l’incidence palustre. En effet, le dégagement des alentours du carbet de toute végétation et une certaine distance de celui-ci à la forêt sont des facteurs protecteurs. La composante géographique est également apparue essentielle à Camopi avec une incidence qui variait selon le fleuve d’habitation et en fonction de la distance au hameau principal. Les facteurs météorologiques locaux (température et niveau du fleuve) se sont également révélés être liés à l’incidence du paludisme à court terme (0-3 mois). Par ailleurs, nos résultats ont permis d’émettre un certain nombre d’hypothèses quant à la transmission et au(x) vecteur(s) local(ux), et notamment de suggérer la participation d’un vecteur autre qu’An. darlingi dans la transmission du paludisme à Camopi. Nous avons également prouvé par ce travail que la télédétection et les systèmes d’information géographique sont très prometteurs pour la prise en compte de la dimension spatiale et environnementale dans l’étude des maladies transmissibles, notamment dans les zones d’accès difficile de Guyane. / The aim of our study was to analyze the incidence of malaria in children and its evolution through time and space, as well as to search for risk factors in a village in Mid-Oyapock (Camopi), populated by Amerindians Wayampi and Emerillon, on the one hand, and a village in Upper-Maroni (Antecume Pata), populated by Amerindians Wayana, on the other hand. The approach was multiple with, for both study sites:- A survival analysis (Cox modelling) completed out of biologically confirmed malaria attacks in a cohort of children under seven, as well as a Knowledge, Attitudes, Practices and Behavior (KAPB) questionnaire, and also the characteristics of the houses and the description of their immediate environment.- A spatial analysis with a land cover classification from SPOT 5 satellite images, the extraction of environmental variables, the study of their effect on malaria transmission and the development of an objective method for picking the proper observation horizon around houses in order to characterize the environment.- A time series study (ARIMA) to determine the effect of climatic and hydrological events on malaria at local and global (El Niño) scales.The incidence rates of malaria attacks during the period 2001-2009 were particularly high among young children, especially in Camopi with an average of 773‰ by year. A sharp decline in incidence occurred in 2007 on the Upper Maroni and this phenomenon has been observed in Camopi since 2010. An acquired immunity develops quite rapidly during the life (2-3 years old), especially against P. vivax relapses. Environmental factors were found to be the most strongly associated with malaria incidence. Indeed, living in a hut cleared from the surrounding vegetation and at a larger distance from the forest are protective factors. The geographic component also appeared essential in Camopi with an incidence which varied with the river of living and with the distance from the main hamlet. The local meteorological factors (temperature and river level) also proved to be linked to malaria incidence in the short term (0-3 months). Moreover, our results have allowed issuing a number of assumptions about the transmission and the local vector(s), in particular to suggest the involvement of another vector than An. darlingi in the malaria transmission in Camopi. We also proved by this work that remote sensing and geographic information systems hold great promise for the inclusion of the spatial and environmental dimensions in the study of transmitted diseases, especially in areas of difficult access in French Guiana.
152

Optical Tweezers and Its use in Studying Red Blood Cells - Healthy and Infected

Paul, Apurba January 2016 (has links) (PDF)
The experiment discussed in the next chapter was to confirm the aforementioned bystander effect. In the first experiment we separated hosting and non-hosting mRBCs by the percol purification method and then measured the corner frequencies of them. The mean fc of the distribution is almost the same, and this confirms the effect of the parasite on the non-hosting mRBC. In the next experiment, we have incubated nRBCs in the spent media and measured the corner frequency at six-hours intervals to see how the fc changed with the incubation time. The results showed that within 24 hours, the fc of the incubated nRBCs increases to the level of the iRBCs. The fact that nRBCs are getting affected by the spent media indicates that some substances must be released in the spent media which alter the physical properties of the nRBCs. This kind of effect on non-host mRBCs was previously observed by some earlier works [Dondorp97, Sabolovic91a, Bambardekar08]. It has also been recently shown that the rosetting of the host mRBCs to the non-host mRBCs is also activated by the substances released in the medium [Handunnetti89, Wahlgren89], which are also somewhat similar to the bystander effect observed by us. In addition to this, there are reports which suggest that sickle cell disease also shows binding properties [Roseff08, Zhang12] which may be due to the substances released in the medium. So it was already observed that the released substances induced changes in the properties of RBCs, but our study gives a direct confirmation of the same. The next study was to find out the released substances which were responsible for the observed changes above. We incubated infected and uninfected RBCs in different drugs. Then, we measured them to see what kind of changes occur in the corner frequency of the incubated RBCs. The corner frequency of normal RBCs incubated in db-cAMP shows the maximum change. So the released substance that is responsible for the bystander effect may be due to the db-cAMP. All the experiments above were done using samples cultured only in the lab. Since the environment of the blood taken directly from the patient may differ from the one that is cultured in the lab, it is natural to find out if similar kinds of changes can be observed in the clinical sample or not. The study in chapter 6 was targeted to find out the same. We took clinical samples from BMRI for patients having a confirmed malaria infection by both P. falciparum and P. vivax. This also provided us the opportunity to work with the P. vivax infected sample as it is very difficult to culture them in the lab. The results shown in this chapter clearly indicate that similar kinds of changes occur in the clinical sample also. It is worth noting that even though P. vivax infects only immature RBCs (reticulocytes), changes were also observed in P. vivax samples. This gives us another strong confirmation about the previously observed bystander effect. This also indicates that this technique can be used as a tool to diagnose malaria. Although we cannot differentiate between P. falciparum and P. vivax, this technique combined with other well established techniques can give us more confirmation. So, in all the experiment above we have shown an easy and novel technique which can be used to differentiate between normal and malaria-infected RBCs. We have also observed the bystander effect and tried to find out the released substances which are responsible for this effect. We have shown that this technique can use the bystander effect of malaria to identify malaria. It has also been shown that the RBCs taken from the patient sample also show the same changes as the cultured samples, which gives us the possibility that this technique can be used as a diagnostic tool combined with other technique. This technique can also be used in experiments like the effects of drugs and to find out drugs for diseases like malaria. Future outlook 1. We have observed the changes only for malaria. There may be other diseases like sickle cell anemia which can also alter the corner frequency of the distribution of RBCs. We have to find out the specificity of the observed changes. 1 We can directly measure the elasticity of RBCs using dual traps in optical tweezers to find out the effect of different infections and drugs on the rigidity of RBCs and compare the with the data above. 2 We can also study other cells using the same method to see if we can find out any difference between healthy and unhealthy cells.
153

Morbidity and mortality due to Plasmodium vivax malaria in Papua, Indonesia and its control using antimalarial drugs

Douglas, Nicholas Martin January 2011 (has links)
Plasmodium vivax malaria threatens nearly half the world’s population. This relapsing disease may be more severe than previously recognised and is proving refractory to current malaria control measures. This thesis aimed to describe the burden of anaemia and mortality attributable to vivax malaria in Southern Papua, Indonesia, an area endemic for multidrug-resistant P. vivax and P. falciparum, and to determine the potential of currently available antimalarial drugs to reduce transmission of P. vivax in co-endemic regions. Approximately 0.5 million uniquely identified clinical records from patients presenting to Mitra Masyarakat Hospital between April 2004 and May 2009 were matched with corresponding laboratory and pharmacy data in order to determine the burden of anaemia in the hospital setting and the effectiveness of primaquine prescription for preventing P. vivax relapses. Clinical information extracted from patient notes was used to clarify the contribution of P. vivax malaria to a series of deaths detected by an active hospital-based surveillance system. Additional secondary sources of data used in this thesis included a large house-to-house survey and multiple clinical trials of antimalarial therapy from both Southern Papua and Northwestern Thailand. In Southern Papua, P. vivax malaria is an important cause of haematological morbidity both in the hospital and community setting. This morbidity is most significant in the first year of life when P. vivax infection accounts for 23% of all severe anaemia (haemoglobin <5g/dL) in the hospital and approximately 28% of all moderate-to-severe anaemia (haemoglobin <7g/dL) in the community. In this region concomitant P. vivax infection accentuates haematological impairment associated with P. falciparum malaria. Plasmodium vivax in Southern Papua rarely causes death directly but rather indirectly contributes to mortality through exacerbation of comorbid conditions. In Northwestern Thailand, 53.8% of patients with falciparum malaria who were treated with a rapidly eliminated drug between 1991 and 2005 had a recurrence of vivax malaria within two months making P. vivax infection the most common cause of parasitological failure in these individuals. Slowly eliminated artemisinin combination therapies (ACT) provided the greatest protection against recurrent P. vivax parasitaemia during 63 days of follow-up. In three randomised controlled trials from Papua and Thailand, P. vivax gametocytaemia was shown to mirror asexual parasitaemia closely and to have the same characteristics in acute and recurrent infections. This emphasises that the most important chemotherapeutic means of blocking P. vivax transmission is prevention of future relapse. Primaquine is recommended for this purpose but analyses in this thesis suggest that in Southern Papua, unsupervised primaquine at a dose of 0.5mg/kg/day for 14 days, does not reduce the risk of subsequent relapse (Adjusted Hazard Ratio = 1.01 [95% confidence interval 0.95-1.07]). Plasmodium vivax malaria should not be neglected. High priority must be given to new hypnozoitocidal drug discovery. In the interim, optimising the safety and effectiveness of primaquine and adoption of a unified ACT-based blood schizontocidal treatment strategy for malaria of any parasitological cause in co-endemic regions will be crucial for controlling P. vivax malaria.
154

Avaliação do nível de concordância do teste imunocromatográfico OptiMAL-IT® e a gota espessa no diagnóstico da malária, no município de Mazagão-AP, Brasil

FADUL, Danielle Scerne January 2007 (has links)
Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-07T16:03:10Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoNivelConcordancia.pdf: 1258819 bytes, checksum: 6d1ffa3e55c412538882010cdc01808f (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2014-02-13T16:58:07Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoNivelConcordancia.pdf: 1258819 bytes, checksum: 6d1ffa3e55c412538882010cdc01808f (MD5) / Made available in DSpace on 2014-02-13T16:58:07Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoNivelConcordancia.pdf: 1258819 bytes, checksum: 6d1ffa3e55c412538882010cdc01808f (MD5) Previous issue date: 2007 / O diagnóstico precoce e o tratamento adequado dos casos de malária é a principal estratégia para o controle da doença. Várias alternativas para o diagnóstico microscópico tradicional foram propostas nos últimos anos, os testes imunocromatográficos que capturam antígenos alvos dos parasitos da malária estão sendo propostos, como o teste OptiMAL-IT® que detecta a desidrogenase lática do Plasmodium sp.. O estudo teve como objetivo a avaliação do nível de concordância entre o teste imunocromatográfico (OptiMAL-IT®) e a gota espessa para o diagnóstico da malária no Município de Mazagão – Amapá. Foram analisados 413 indivíduos com sintomatologia de malária, que procuraram o serviço da Unidade Mista de Saúde de Mazagão, com idade entre 01-68 anos. Os resultados do teste OptiMAL-IT® foram comparados com os resultados obtidos (das amostras) através da gota espessa corada pelo Giemsa. Dos 413 pacientes suspeitos de apresentarem malária, 317(76.8%) eram positivos através da GE e 311 (75.3%) eram positivos pelo TDR. Das lâminas de GE positivas, foram encontrados 27.4% de P. falciparum e 72.6% de P. vivax. O teste OptiMAL-IT® detectou 27.7% de P. falciparum e 72.3% de P. vivax. A sensibilidade obtida com o TDR para o P. falciparum foi de 97.7% e para o P. vivax foi de 98.2%, a sensibilidade global do TDR foi de 98.1% e a especificidade global e para ambas as espécies foi de 100%. Foram encontrados valores preditivos positivos e negativos de 100% e 94.1%, respectivamente. O teste OptiMAL-IT®, teve uma alta concordância com a GE, foi específico e eficiente, podendo ser usado no diagnóstico de malária nas situações onde a microscopia não está disponível. / The precocious diagnosis and the opportune treatment of the cases of malaria is one of the main strategies for the control of the disease. Several alternatives for the traditional microscopic diagnosis were proposed in the last years, the Immunochromatographic tests that capture white antigens of the parasites of the malaria they are being proposed, as the test OptiMAL-IT® that captures the lactic desidrogenase of the Plasmodium sp.. The study had as objective the evaluation of the level of agreement between the Immunochromatographic test (OptiMAL-IT®) and the thick drop for the diagnosis of the malaria in the City of Mazagão – Amapá, Brazil. 413 individuals were analyzed with malaria sintomatology that had looked for the service of the unit of health service of the city, with age among 01-68 years. The results of the OptiMAL-IT® test were compared with the obtained results, of the same samples, through the thick drop red-faced by the Giemsa. Of the 413 patients suspicious to present malaria, 317(76.8%) were positive through GE and 311 (75.3%) were positive for TDR OptiMAL-IT®. Of the positive blades of GE, had been found 27.4% of P. falciparum and 72.6% of P. vivax . The OptiMAL-IT® test detected 27.7% of P. falciparum and 72.3% of P. vivax. The sensibility obtained with TDR for P. falciparum was of 97.7% and for P. vivax was of 98.2%, the global sensibility of TDR was of 98.1% and the global specificity for both the species was of 100%. They were found preditivos values positive and negative of 100% and 94.1%, respectively. The OptiMAL-IT® test had a high agreement with thick drop, it is specific and efficient. It can be used in the diagnosis of malaria in the situations where microscopy is not available.
155

Avaliação da adesão ao tratamento preconizado para malária: determinação da primaquina em pacientes diagnosticados com Plasmodium vivax

GONÇALVES FILHO, Wilson Vieira 31 March 2016 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-06-26T15:23:07Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_AvaliacaoAdesaoTratamento.pdf: 2067376 bytes, checksum: 3c5af254a9831ca1ae13900e6d751a32 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-06-26T18:28:34Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_AvaliacaoAdesaoTratamento.pdf: 2067376 bytes, checksum: 3c5af254a9831ca1ae13900e6d751a32 (MD5) / Made available in DSpace on 2017-06-26T18:28:34Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_AvaliacaoAdesaoTratamento.pdf: 2067376 bytes, checksum: 3c5af254a9831ca1ae13900e6d751a32 (MD5) Previous issue date: 2016-03-31 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas / A malária é uma doença que ameaça 50% da população mundial, que vivem em zonas endêmicas, como África, Sudoeste Asiático e América Latina. No que se refere à malária causada por Plasmodium vivax no Brasil, cujo tratamento é baseado em primaquina e cloroquina, é um importante problema de saúde pública que atrapalha o desenvolvimento da região Amazônica e que a adesão à terapia medicamentosa é um dos principais fatores que influenciam na eficácia do tratamento. Este estudo utiliza métodos indiretos para avaliar a adesão ao tratamento, correlacionando-a com a concentração plasmática de primaquina e carboxiprimaquina. Desse modo foi realizado um estudo observacional transversal controlado com 27 pacientes, na cidade de Anajás - Pará, antes (D0) durante (D1) e após (D7) o tratamento com o antimalárico, seguido de avaliação os pacientes com perguntas baseadas no teste de Morisky-Green ao final do tratamento. Foi possível observar maior prevalência da malária vivax em indivíduos do sexo masculino (70,4%) e na faixa etária de 20 a 39 anos (55,56%), o teste de Morisky-Green indicou uma adesão de 75%, 15 de um total de 20 pacientes, com uma taxa de acerto de 80%, 65%, 70% e 65% para as perguntas. A concentração média de primaquina no D1 foi de 134,8 ng/mL, no D7 de 131,9 ng/mL, e os valores de carboxiprimaquina foram de 408 ng/mL e 529,4 ng/mL respectivamente. É possível observar diferença estatisticamente significativa entre os valores do carboxiprimaquina em D1 e D7 no grupo dos aderentes definido pelo teste de Morisky-Green, mostrando que a carboxiprimaquina se acumula no organismo, sendo assim mais indicada para avaliar a adesão ao tratamento. Dessa forma, é importante ressaltar que estas concentrações de primaquina e carboxiprimaquina são as primeiras determinações de fármacos e metabólitos encontradas para o tratamento curto preconizado pelo Ministério da Saúde para malária vivax na região amazônica, corroborando para a pesquisa de avaliação da adesão aos antimaláricos. / Malaria is a disease that threatens 50% of the world population living in endemic areas such as Africa, Asia and Latin America. Concerning malaria caused by Plasmodium vivax in Brazil, which treatment is based on primaquine and chloroquine, it is a major public health issue that hinders the development of the Amazon region and adherence to drug therapy is one of the main factors that influence the effectiveness of the drug. This study uses indirect methods assess treatment adherence, correlating it with plasma concentrations of primaquine and carboxyprimaquine. Thus, a cross-sectional observational controlled study was conducted with 27 patients in Anajás, Pará before (D0), during (D1) and after (D7) treatment using the antimalarials, followed by the assessment of the patients with questions based on Morisky-Green test at the end of the treatment. Higher prevalence of vivax malaria was observed in males (70.4%) and age group of 20-39 years (55.56%), Morisky-Green test indicated adherence of 75%, 15 out of 20 patients, with hit rates of 80%, 65%, 70% and 65% to the questions. Mean-value of primaquine concentration on D1 was 134.8 ng/mL, and 131.9 ng/mL on D7, values for carboxyprimaquine are 408 ng/ml and 529.4 ng/mL respectively. It is possible to observe a statistically significant difference in the carboxyprimaquine values between D1 and D7 in the acceding group defined by the Morisky-Green tests, showing that carboxyprimaquine accumulates in the body; therefore being more suitable for assessing adherence to treatment. Therefore, it is important to point out these concentrations of primaquine and carboxyprimaquine consist as the first determination study of drugs and metabolites found for the short-course treatment suggested by the Ministry of Health for vivax malaria in the Amazon region, supporting the studies of adherence surveys regarding antimalarials.
156

1-deoxy-D-xylulose-5-phosphate Synthase (DXS) Mechanistic Study and its Implication in the Development of Novel Antibiotics and Antimalarials

Handa, Sumit 01 January 2012 (has links)
Isoprenoids are the largest family of biologically active compounds, synthesized by five carbon subunits namely isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). For long time the mevalonate-dependent (MVA) pathway has been considered as the sole source of IPP and DMAPP, until recently a new non-mevalonte dependent (NMVA) pathway was discovered. This new pathway utilizes entirely different set of enzymes for isoprenoids synthesis and don't have any homologues in humans. NMVA pathway is the only source of isoprenoids for certain eubacteria, parasite and plants. Absence of the NMVA pathway in higher organisms has opened a new platform for the development of novel antibiotics and antimalarials. 1-deoxy-D-xylulose-5-phosphate synthase (DXS), the first enzyme in NMVA pathway has been reported as the rate limiting enzyme in the synthesis of IPP and DMAPP and has been the center of interest for inhibitor development. Reaction mechanism of thiamine pyrophosphate (TPP) and Mg2+ dependent DXS enzyme has been studied in this report. Using steady state kinetics analysis, product inhibition and dead end inhibitor, the mechanism of substrate (pyruvate and D-glyceraldehyde-3-phosphate) addition was studied. Due to different domain organization in DXS as compared to theother TPP dependent enzyme, the mechanism of addition was found to be random sequential rather than ping-pong mechanism. Based on bioinformatics tool and in vitro studies it has been established that NMVA exists in all the plasmodium species, thus making the enzymes involved in NMVA as an alluring target for new antimalarial drugs. All the plasmodium species and other member of the phylum apicomplexa harbor apicoplast an organelle which is homologous to the chloroplast of plants and algae. All the enzymes from NMVA pathway translocate to apicoplast from nucleus through a secretory pathway using signaling and transit peptide. In this study DXS from P. vivax has been cloned and expressed in E. coli using genomic DNA and codon optimized synthetic DNA as a source. Expression of full length DXS with signal and transit peptide as well as mature protein without these peptide using serial deletion has been studied. Kinetic parameters of P.vivax DXS have been calculated and found to be comparable to the DXS from other species.
157

Avaliação da resposta de anticorpos contra antígenos de Plasmodium vivax relacionada a fatores genéticos do parasito e do hospedeiro humano /

Melo, Luciane Moreno Storti de. January 2011 (has links)
Orientador: Ricardo Luiz Dantas Machado / Banca: Cláudio Tadeu Daniel Ribeiro / Banca: Érika Martins Braga / Banca: Claudia Regina Bonini Domingos / Banca: Érika Cristina Pavarino Bertelli / Resumo: O presente estudo avaliou a resposta de anticorpos contra diferentes antígenos de merozoíto e esporozoíto de Plasmodium vivax, relacionando com as variantes da porção repetitiva do domínio central do gene da Proteína Circunsporozoítica (CSP) do parasito (VK210, VK247 e P. vivax-like) e com os polimorfismos do HLA-DRB1 no hospedeiro humano. A resposta de anticorpos foi avaliada para peptídeos das regiões conservadas e centrais variáveis da CSP, da porção N-terminal da Proteína de Superfície do Merozoíto 1-MSP1 (Pv200L), e recombinante do Antígeno 1 de Membrana Apical (AMA-1) e a Proteína de ligação ao Duffy (DBP) por ELISA, em amostras de plasma de pacientes naturalmente infectados com P. vivax. Inicialmente nós avaliamos a distribuição destas variantes da CSP em cinco diferentes áreas da Amazônia a fim de entender sua atual dinâmica de transmissão. A variante VK210 continua sendo a mais prevalente em todas as áreas estudadas. No entanto, pela primeira vez documentamos a presença das variantes VK247 e P. vivax-like como infecções simples na Amazônia brasileira evidenciando um novo perfil distribuição destas, o que possa sugerir um processo de adaptação das mesmas. Quando comparamos a resposta de anticorpos e a infecção pelas variantes de P. vivax, não foram observadas associações significativas entre a presença de determinada variante da CSP e a freqüência de resposta de anticorpos contra os três peptídeos do merozoíto analisados, MSP1 (Pv200L), AMA-1 e DBP e nem contra as frações conservadas da CSP no esporozíto, N-terminal [N] e C-terminal [C]. A falta de associações significativas entre resposta sorológica contra esses peptídeos fornece informações promissoras quanto à utilização destes antígenos para o desenvolvimento de uma vacina contra malária. Todavia, a variação na porção central da CSP deve ser considerada... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study evaluated the antibody response against merozoite and sporozoite antigens of Plasmodium vivax and its relationship with the variants of the repetitive central region of the gene for Circunsporozoite protein (CSP) in parasite (VK210, VK247 and P. vivax-like) and, with the HLA-DRB1 polymorphisms in human host. The antibody response to synthetic peptides of the CSP conserved and variable regions and of the N-terminal portion of Merozoite surface protein - MSP1 (Pv200L), and, to recombinants peptides of the Apical Membrane Antige 1 (AMA-1) and of the Duffy Binding Protein (DBP) was evaluable by ELISA in plasma samples of malaria patients naturally infected with P. vivax. Firstly, we evaluated the CSP variants distribution among five different areas from Brazilian Amazon, in order to understand their current dynamic of transmissions. VK210 variant remains the most prevalent in all study areas. However, it is the first detection of VK247 e P. vivax-like variants as simple infection in the Brazilian Amazon, showing a new distribution profile, which may suggest an adaptation process of them. When comparing the antibody response and infection by variants of P. vivax, there were no significant associations between the presence of particular CSP variant and the frequency of antibody response against all three merozoite peptides analyzed, MSP1 (Pv200L), AMA-1, DBP and against the CSP conserved fractions in the sporozoite, N-terminal and C-terminal. The lack of significant associations among immune response against these peptides provides promising information regarding the use of these antigens for malaria vaccine development. On the other hand, the central variability of CSP should be considered to employment of this region as an immunogen, since the antibody response appears to be variant-specific. In order to evaluate the polymorphisms... (Complete abstract click electronic access below) / Doutor
158

Identificação de potenciais determinantes imunológicos de gravidade na malária humana / Identification of potential immunologic determinants of severity in human malaria

Andrade, Bruno de Bezerril January 2010 (has links)
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-06-05T21:05:38Z No. of bitstreams: 1 Bruno de Bezerril Andrade - 2010.pdf: 74164438 bytes, checksum: a1cccf3d1f924ff7710fc4a73a190f0a (MD5) / Made available in DSpace on 2012-06-05T21:05:38Z (GMT). No. of bitstreams: 1 Bruno de Bezerril Andrade - 2010.pdf: 74164438 bytes, checksum: a1cccf3d1f924ff7710fc4a73a190f0a (MD5) / Universidade Federal da Bahia. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / A malária é considerada uma das mais importantes doenças infecciosas do mxmdo. Esta doença é causada por diversas espécies do protozoário Plasmodium sp., principalmente o Plasmodium falciparum e o Plasmodium vivax, transmitido por mosquitos do gênero Anopheles. Apesar dos esforços governamentais e privados para o desenvolvimento de estratégias para o controle da doença, o panorama atual da malária está piorando, muito em razão do aparecimento de cepas de parasitas resistentes aos medicamentos. Os casos fatais são relatados principalmente na Áfiica e são causados pelo Plasmodium falciparum. Apesar de ser menos letal, a malária causada pelo Plasmodium vivax é mais amplamente distribuída e pode apresentar também alta morbidade e mortalidade. Na maioria das áreas endêmicas, estudos têm identificado vários fatores relacionados à imunidade clínica ou susceptibilidade aos parasitas. Assim, pelo menos quanto à malária causada pelo Plasmodium falciparum, idade, polimorfismos genéticos e exposição repetida ao parasita são considerados importantes determinantes da evolução da doença. Infelizmente, pouco tem sido feito na identificação de fatores preditores consistentes que poderiam ser usados para avaliação clínica. Este quadro é ainda pior para malária causada pelo Plasmodium vivax, provavelmente porque muitos pesquisadores consideram que é uma doença benigna. Além disso, como a maioria do conhecimento atual sobre a patogênese da malária não ajudou a reduzir a ocorrência da infecção e suas complicações, novas abordagens são necessárias para superar este cenário desfavorável. Esta Tese reúne um conjunto de seis manuscritos que visam identificar potenciais determinantes da gravidade da malária em uma área endêmica da Amazônia Ocidental Brasileira. Em primeiro lugar, um método preciso e eficaz para o diagnóstico da malária foi rastreado através da comparação de vários testes, incluindo um software baseado em redes neurais artificiais. O ensaio molecular mostrou-se o mais eficiente para o diagnóstico da malária sintomáticos e assintomáticos. Além disso, a utilização racional de um teste rápido para diagnóstico da malária pode ser promissora em áreas onde há dificuldade na formação continuada dos técnicos diagnósticos. A rede neural artificial indicou que o balanço de citocinas é um forte determinante do quadro clínico. Em outro estudo, uso de sorologia para mensuração de anticorpos IgG contra o sonicado de glândula salivar do vetor Anopheles darlingi mostrou-se útil para a avaliação da exposição ao Plasmodium vivax e também para estimar a imunidade clínica á malária. Em um terceiro estudo com foco na identificação de outros fatores relacionados à imunidade clínica, a exposição natural ao vírus da hepatite B mostrou-se associada à redução da gravidade clínica da malária causada tanto pelo Plasmodium vivax quanto pelo Plasmodium falciparum. No que diz respeito exclusivamente à malária vivax, os casos graves apresentaram uma intensa e desregulada resposta inflamatoria sistêmica. Nestes pacientes, a enzima antioxidante superóxido dismutase-1 surgiu como um excelente marcador da gravidade e mostrou-se envolvida na patogênese da doença grave, na qual há uma liberação de grandes quantidades de heme livre. Em conjunto, os manuscritos desta tese adicionam importantes informações no entendimento dos mecanismos determinantes da gravidade da malária, extremamente / Malaria is considered one of the most important infectious diseases that ever threaten the world. This disease is caused mainly by the infection with Plasmodium falciparum or Plasmodium vivax transmitted by Anopheles mosquitoes. Despite governmental and private efforts for the development of key strategies for the disease control, the actual panorama of the Plasmodium infection is getting worse due to the emergence of drug resistMt parasite strains. The lethal cases are reported mostly in Africa and are caused by Plasmodium falciparum. Albeit being less lethal, Plasmodium vivax infections are more widely distributed can cause high morbidity and eventually death. In most endemic areas, studies have indentified a number of factors related to clinical immunity or susceptibility to the parasites. Thus, at least regarding the falciparum malaria, age, genetic polymorphisms and repeated exposure to Plasmodium are considered most important determinants of the disease outcome. Unfortunately, little has been made in the screening of reliable predicting factors that could be ultimately used for clinical evaluations. This landscape is even worse for vivax malaria, probably because many researches consider it as a benign disease. Moreover, as most of the current knowledge about the malaria pathogenesis did not truly help to relieve the disease burden, new insights are necessary to overcome this unfavorable scenario. This thesis brings together a set of six manuscripts that aim to identify potential determinants of the disease severity linked to the immunopathogenesis in an endemic area from the western Brazilian Amazon. First, a precise and effective method for malaria diagnosis was screening by comparing multiple tests, including a software based of artificial neural networks. The molecular assay showed to be the most efficient for the diagnosis of symptomatic and asymptomatic malaria. In addition, the rational use of a rapid test for the diagnosis of malaria may be promising in areas where there is difficulty in continued training of technical human resources. The artificial neural network indicated that the cytokine balance is a strong determinant of the clinical presentation. In another study, the use of serology for measuring IgG antibodies against the sonicate salivary gland of Anopheles darlingi vector is a promising marker of exposure to Plasmodium vivax and can also estimate the clinical immunity. Intriguingly, the natural exposure to the hepatitis B virus appeared as an important factor associated with reduced clinical severity for both vivax and falciparum malaria. Concerning solely the vivax malaria, severe cases have an intense and unregulated inflammatory response. In these patients, the antioxidant enzyme superoxide dismutase-1 has emerged as an excellent marker of severity and was involved in the pathogenesis of the severe disease in which there is a release of large amounts of free heme. Together, the manuscripts of this thesis add important information in understanding the mechanisms that determine the severity of malaria.
159

Alterações clínicas, hematológicas, bioquímicas e histopatológicas em ovinos infectados experimentalmente por Trypanosoma vivax (Ziemann, 1905) /

Almeida, Katyane de Sousa. January 2007 (has links)
Orientador: Adjair Antonio do Nascimento / Banca: Celio Raimundo Machado / Banca: Luiz Augusto do Amaral / Banca: Katia Denise Saraiva Bresciani / Banca: Milton Hissashi Yama / Resumo: A infecção experimental por T. vivax em ovinos foi realizada com o objetivo de avaliar os sinais clínicos, a parasitemia, as alterações hematológicas, anatomopatológicas e bioquímicas, além de realizar a biometria do parasito. Para tanto, foram utilizados oito ovinos machos, sorologicamente negativos para T. vivax, sendo quatro destinados ao grupo testemunho e quatro infectados com 105 T. vivax. As colheitas de sangue foram realizadas duas vezes antes da infecção e, posteriormente, em dias determinados, destinados aos exames laboratoriais. Exames clínicos e parasitemias foram realizados diariamente; e o peso, um dia antes da infecção, e com intervalos de 30 dias, a necropsia foi realizada aos 120 dias após infecção. Observou-se que a amostra usada era típica de T. vivax e o período prépatente de um dia, com parasitemia intermitente até o final do experimento. Os sinais clínicos encontrados nos animais infectados foram: apatia, palidez das mucosas, emaciação, aumento dos linfonodos, corrimento nasal, hipertermia, alterações no peso, diarréia e neuropatias. Ocorreu diminuição significativa na contagem global de hemácias, no teor de hemoglobina, no hematócrito e no volume corpuscular médio. A anemia, no final da observação, foi microcítica normocrômica, e leucocitose causada por linfocitose. Todos os exames bioquímicos apresentaram alterações nos animais infectados em relação ao grupo testemunho exceto a tiroxina total. No geral, observou-se: diminuição do colesterol total, colesterol ligado ao HDL, do lipídio total hepático, dos glicogênios hepático e muscular, ferro, magnésio, gamaglutamiltransferase, aspartatoaminotransferase, fosfatase alcalina, creatinaquinase, lactatodesidrogenase, triiodotironina, cortisol e nas proteínas da fase aguda, exceto a transferrina e antitripsina que estiveram altas no final do período experimental...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this research was to study an experimental infection of T. vivax in sheep, evaluating clinical signs and parasitemia as well as hematological, anatomopathological and biochemical alterations and to obtain the biometric data of the parasite. Eight male sheep were used, four in the testimony group and four infected with 105 T. vivax .Blood samples were collected two times before and posterior to receiving the infection on days designated and determined by laboratory exams. The animals were examined daily, as well as the clinical aspects and parasitemia. The animals were also weighed one day before the infection and in 30 day intervals, until they were sacrificed. The following results were obtained: the sample used was typical of T. vivax and the parasites were detected in the blood on the first day after the infection of the intermittent parasite until the end of the experiment. The clinical signs found were: apathy, paleness of the mucous, emaciation, lymph gland enlargement, runny nose, hyperthermia, weight alterations, diarrhea and neurological signs. There was a significant decrease in the global hemacia count, hemoglobin and in the hematocritic and in the average packed cell volume. The anaemia, at the end of the observations, were microcitic, normochromic and leucocitosis due to the lymphocytes. All of the biochemical exams presented alterations in the animals infected in relation to the testimony group except for the thyroxine. In general, was observed: decrease in total cholesterol, HDL, total hepatic lipid, hepatic and muscular glycogen, iron, magnesium, gamaglutamiltrasnferase, aspartate aminotransferase, alkaline phosphatase, creatine kinase, lactate desidrogenase, triiodothyronine, cortisol and proteins in the acute phase except the transferrin and antitrypsin that were high at the end of the experimental period...(Complete abstract, click electronic address below) / Doutor
160

Estado nutricional na malária: influência nos aspectos clínicos e laboratoriais de pacientes naturalmente infectados por Plasmodium vivax

MONTE, Carlos Rodrigo Souza do 10 November 2015 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-17T12:27:16Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstadoNutricionalMalaria.pdf: 1789600 bytes, checksum: d1e8544fa76134d12e67a05eff210f30 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-10-24T14:31:32Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstadoNutricionalMalaria.pdf: 1789600 bytes, checksum: d1e8544fa76134d12e67a05eff210f30 (MD5) / Made available in DSpace on 2017-10-24T14:31:32Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstadoNutricionalMalaria.pdf: 1789600 bytes, checksum: d1e8544fa76134d12e67a05eff210f30 (MD5) Previous issue date: 2015-11-10 / FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas / A malária é considerada pela Organização Mundial de Saúde um problema global de saúde pública. No Brasil, a maioria dos casos ocorre por P. vivax. Esse estudo objetivou avaliar a influência da obesidade nos marcadores inflamatórios, bioquímicos, hematológicos, parasitológicos e manifestações sintomatológicas em pacientes com malária vivax. Participaram 78 pacientes (37 eutróficos, 25 sobrepeso e 14 obesos) com diagnóstico de malária por P. vivax de população residente de área hiperendêmica no Estado do Pará. O estado nutricional não apresentou influência na carga parasitária nesta população infectada por P. vivax, embora tenha sido observada tendência a parasitemia mais elevadas nos obesos. A frequência das manifestações clínicas, tais como calafrio, cefaleia, tríade malárica (febre, calafrio e cefaleia), mialgia, tosse e diarreia e o escore clínico, foram mais altos nos obesos em comparação aos eutróficos. Pacientes obesos apresentaram elevado nível de leucócitos totais, neutrófilos, monócitos, triglicérides, colesterol total, VLDL, AST e ALT em comparação aos eutróficos. Os níveis séricos das citocinas moduladoras da inflamação TNF-α e IL-10 não diferiram entre os grupos nutricionais, entretanto houve uma correlação negativa entre o TNF-α e a circunferência abdominal. O nível sérico de citocinas moduladoras da inflamação (TNF-α e IL-10) influenciaram a parasitemia, perfil hematológico, perfil bioquímico e o escore clínico de indivíduos naturalmente infectados por P. vivax. O estado nutricional influenciou a resposta imune na infecção pelo P. vivax, sendo um importante determinante de risco neste estudo. Embasado nessas considerações, outras pesquisas são necessárias para o melhor entendimento da doença nesse contexto. / Malaria is considered by the World Health Organization a global public health problem. In Brazil, most cases occur by P. vivax. This study aimed to evaluate the influence of obesity on inflammatory markers, biochemical, hematological, parasitological profiles and clinical manifestations in vivax malaria patients at Pará State. Seventy-eight (37 eutrophic, 25 overweight and 14 obese) patients positive to P. vivax were included. Chills, headache, malaria triad (fever, chills and headache), myalgia, cough and diarrhea were more frequent, whereas the clinical score were higher in obese compared to normal weight patients. Obese patients had a higher level of count of total leukocytes, neutrophils, monocytes, triglycerides, total cholesterol, VLDL, AST, ALT compared to lean patients. Parasitaemia was similar among nutritional status, although was observed trend to higher parasitaemia (> 5.000 parasites/μL) in obese patients. Serum levels of TNF-α and IL-10 did not differ among nutritional groups, though there was a negative correlation between TNF-α and waist circumference. Among overweight and obese was observed a positive correlation between IL-10 and parasitemia, neutrophils, urea and a negative correlation with red blood cells, lymphocytes, platelets. Throughout, TNF-α was correlated negativity with the clinical score. Nutritional status influences immune response against the infection and it has been an important risk factor in this findings. However, further studies are required to understand the malaria in this context.

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