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Strategies to control Yaws and other Neglected Tropical Diseases in the South Pacific Islands / Estrategias para el control del Pián y otras Enfermedades Tropicales Desatendidas en Islas del Pacífico SurMitjà Villar, Oriol 01 June 2012 (has links)
Every year, through mass drug administration (MDA), hundreds of millions of the world’s poorest people receive a single annual dose of one or more drugs to eliminate certain parasitic worm or bacterial infections. Some of these infections, mostly prevalent in tropical areas, have traditionally been neglected from the public health and research point of view. These conditions, collectively known as the neglected tropical diseases (NTDs), still cause, at the cusp of the second decade of the 21st century, a significant amount of morbidity and mortality. The existing control measures for NTD have an enormous potential, although there are still some challenges that require further investigation. For some diseases, alternative strategies may be needed, including longer duration of MDA programmes or modified drug regimens. For other diseases, such as yaws, the work must start almost from scratch, since little has been achieved in terms of control of this disease in the past 50 years. Although eight NTDs affect the region, two diseases pose a major public health problem in the South Pacific Islands, namely yaws and lymphatic filariasis and are the basis for his thesis. These two infections were selected for a number of reasons. First, they affect the South Pacific region disproportionately. Secondly, little research has been conducted in the past years. And third, but more importantly, several epidemiological, technological and historical factors make these two diseases amenable to elimination. Safe and effective tools and interventions to achieve these targets are available and concerted efforts to scale them up are likely to lead to success.
Yaws is one of the most neglected of the NTDs. Yaws was one of the first diseases to be targeted for eradication on a global scale, efforts which almost led to the disease disappearance as a result of a massive treatment program started in the 1950s. After the successful eradication campaigns the primary health care systems were supposed to give the last push towards eradication of yaws. However a combination of various factors including poor political commitment and limited funding resulted in a progressive abandonment of efforts and the resurgence of the disease. Every new case of yaws was the disappointing confirmation that the public health world had missed a great opportunity.
Today yaws has resurged in many tropical areas and presents new challenges including its unknown epidemiological situation, the attenuated clinical forms of the disease, a poor awareness and knowledge among health care workers, the lack of knowledge about the effectiveness of classic treatment with penicillin and, an obvious need for research into simplified administration schemes or new antibiotic treatments, particularly oral ones.
There is an enormous knowledge gap regarding current reliable epidemiological information about the disease. Certainly we know little about the burden in the three Melanesian countries where the disease is highly endemic, Papua New Guinea, Solomon Islands and, Vanuatu. In Solomon Islands and Vanuatu there are indications that Yaws is widespread and prevalent, but we know that the diagnosis is unreliable. This takes us to the next point, what does a diagnosis of yaws mean?
Overall the natural history of the disease in this era, where it is often subject to inadequate antibiotic pressure, is very unclear. Some authors have suggested that yaws appears to be attenuated in both Solomon Islands and Vanuatu. They state that bone involvement in yaws is now rare and implies that yaws is a mild disease not requiring efforts for elimination. However, the first paper of this thesis describes the epidemiology of yaws in Lihir Island (Papua New Guinea, PNG) and shows a high rate of classical primary ulcers (almost 60%) and significant bone and periosteal involvement (more than 15%), suggesting that “attenuation” is not an important issue. When we look at the diagnostic criteria for yaws, signs and symptoms alone are still used often in many areas to diagnose the disease. This reliance on clinical findings was the result of the difficulty of performing serological tests in remote areas. Today, available rapid serological tests are simple, rapid, inexpensive and useful for guiding confirmation of cases, making them adequate tools for the diagnosis and monitoring of the disease. The clinical diagnosis of yaws is complicated because its clinical manifestations may be unspecific. Thus, it is possible that a significant proportion of yaws cases may in fact have been falsely diagnosed. We show, in the first article, that in our experience only 60% of the cases with a clinical suspicion of yaws were finally confirmed by serologic tests. Therefore, a proper diagnosis of yaws requires the interpretation of clinical findings with reference to laboratory results and the epidemiologic history of the patient.
Serological testing in yaws is not only important for diagnostic accuracy, but also is very helpful in defining the disease’s evolution and eventual cure after treatment. Rapid plasma regain (RPR) titres should decline within 6-12 months, becoming negative in less than 2 years. The second article of this thesis combines a clinical and serological approach to assess the response after treatment with benzathine benzylpenicillin, and it identifies an overall 20% treatment failure. This could be related to resistance to the antimicrobial drug used or to re-infection caused. The distinction between re-infection and true resistance to antibiotic treatment is difficult to make but these failures are worrisome. This article also proposes a multivariate model performed to identify independent determinants of failure that affected the outcome after treatment. The risk for reinfection caused by repeated contact with infected children seems to be a pivotal predictor of failure. Low baseline titters (<1:32) of RPR are also an important and independent predictor of failure, possibly as a result of the greater difficulty in resolving chronic infections which are usually accompanied by low titters.
With yaws re-emerging, the development of new strategies against this infection aimed at simplifying its treatment and potentially re-focussing strategies towards its eradication seems essential. Injectable penicillin is still effective but management with an oral drug that can be easily administered on a large scale should be the preferred method for treatment. To date, there had been no studies that directly compared the efficacy of penicillin with any of the potentially alternative agents shown to work in the treatment of the non-venereal treponematoses. The fourth paper in this thesis has shown that a single-dose of oral azithromycin is non-inferior to benzathine benzylpenicillin for the treatment of yaws in children in PNG. In an open-label randomised trial, at 6-month follow-up, 96% of patients treated with azithromycin were cured, as were 93% in the benzathine benzylpenicillin group.
The prospects of eliminating and eventually eradicating yaws may now be enhanced by the use of a single-dose of oral azithromycin in mass drug administration campaigns. Community based mass administration of azithromycin has been widely used in many locations for the control of trachoma, which, like yaws, is a disease of poor rural communities in developing countries, and has been used in a more limited way to control granuloma inguinale and outbreaks of venereal syphilis.
Elimination of yaws and lymphatic filariasis in the South-Pacific Islands is now considered biologically feasible and programmatically attainable. The Global Programme to Eliminate Lymphatic Filariasis (GPELF) has expanded quickly to reach the target of elimination by 2020. On the other hand the strategy to eliminate yaws is again at the centre of discussions and given that infected humans are the only source of disease, its eradication could be achieved within a very relatively short time. The fifth article of the thesis comprehensively reviews antimicrobial treatments and elimination strategies against yaws. In order to control yaws and push it towards elimination, we propose to move away from penicillin to azithromycin and use mass treatment campaigns of the entire population in endemic communities irrespective of the prevalence. Also, to make sure all cases are tracked down and treated, strict follow-up measures and selective mass treatment will be required until zero case prevalence is reached. Importantly, we suggest testing the principle of interrupting transmission in pilot implementation studies, including prevalence surveys to assess the impact of the intervention and macrolide resistance monitoring which in our opinion will be essential evaluation tools to guide us towards a sustainable elimination.
Lymphatic filariasis (LF), caused by the mosquito-borne nematode Wuchereria Bancrofti, is a major public-health problem in the Melanesian countries. Annual MDA over five years is currently the WHO’s recommended strategy to eliminate lymphatic filariasis. This approach aims to suppress microfilaraemia in infected individuals and bring the infection below a threshold that leads to interruption of transmission. However theoretical work and clinical field experience has highlighted how the ecological diversity between different endemic regions can result in elimination thresholds that vary between local communities. This means that the duration required might be different for different areas. Other variables have also been previously identified as potentially having an influence on the outcome of the program, including baseline prevalence of infection, vector density or the treatment coverage. The last article of this thesis provides data about the impact of a five-year filariasis control program in Papua New Guinea. The findings reported support this strategy for areas with low-to-moderate rates of transmission in regions where anopheline mosquitoes transmit this infectious disease. Additional measures or longer periods of treatment may be necessary in areas with a high rate of transmission.
The experience acquired on Lihir Island in MDA programs during the campaigns for the elimination of filariasis, will be very valuable when implementing a pilot strategy for yaws control. Also, in the near future it might be important to link yaws mass treatment with other mass programmes to increase efficiency. The plan for elimination of lymphatic filariasis in PNG was approved as a pilot project in 2005 but the program still needs to be extended to the total of 20 provinces in the country where filariasis is endemic. In this context, an integrated approach to NTD control could represent an important global public health solution in PNG and other South Pacific Islands.
Little has been achieved in the past decade in NTDs. We are now in a good position to translate into policies the results of our research projects. A new elimination policy for yaws around the azithromycin pillar has been sketched a WHO consultation meeting held in Morges, Switzerland last March. In the intentions of the organization, a last global mass campaign to tackle yaws should permit to reach zero cases in 2017, and the subsequent certification of worldwide interruption of transmission by 2020. / Cada año, a través de la administración masiva de medicamentos (MDA), cientos de millones de personas, las más pobres del mundo, reciben una dosis única de uno o más medicamentos para eliminar ciertas infecciones, parasitarias o bacterianas. Algunas de estas infecciones, frecuentes sobre todo en las zonas tropicales, han sido tradicionalmente desatendidas desde el punto de vista de salud pública e investigación. Estas enfermedades, conocidas comúnmente como las enfermedades tropicales desatendidas (ETD), aún causan, en el inicio de la segunda década del siglo 21, una cantidad significativa de morbilidad y mortalidad.
Las medidas de control actuales para ETDs tienen un enorme potencial, pero todavía existen algunas cuestiones que requieren investigación. Para algunas de estas infecciones, son necesarias estrategias alternativas, incluyendo una mayor duración de los programas de MDA o regímenes modificados de medicamentos. Para otras enfermedades, como la enfermedad de pián, el trabajo debe comenzar casi desde cero, ya que poco se ha logrado, en términos de control de esta enfermedad, en los últimos 50 años.
Aunque ocho ETDs afectan a la región, dos enfermedades constituyen un problema importante de salud pública en las Islas del Pacífico Sur, a saber: el pián y la filariasis linfática y son la base de esta tesis. Estas dos infecciones fueron elegidas por muchas razones. En primer lugar, afectan a la región del Pacífico Sur de forma desproporcionada. En segundo lugar, pocas investigaciones se han llevado a cabo en los últimos años. Y en tercer lugar, pero lo más importante, varios factores epidemiológicos, tecnológicos e históricos hacen que estas dos enfermedades sean susceptibles de eliminación. Existen armas terapéuticas seguras y eficaces para lograr este objetivo, y esfuerzos coordinados para ejecutar los programas de control pueden conducir al éxito.
El pián es una de las más olvidadas de las ETDs. Ésta fue una de las primeras enfermedades en ser objetivo de erradicación a escala global. Los esfuerzos de un programa de tratamiento masivo, que se inició en la década de 1950, casi llevaron a la desaparición de la enfermedad. Después de las exitosas campañas de erradicación, los sistemas de salud de atención primaria debían dar el último empujón hacia la erradicación del pián. Sin embargo, una combinación de varios factores, incluyendo un pobre compromiso político y una financiación limitada, dieron como resultado el abandono progresivo de los esfuerzos y el resurgimiento de la enfermedad. Cada nuevo caso de pián era la decepcionante confirmación de que el mundo de la salud pública había perdido una gran oportunidad.
Hoy la enfermedad de pián ha resurgido en muchas áreas tropicales con nuevos desafíos: una situación epidemiológica desconocida, formas clínicas atípicas o atenuadas, poco conocimiento de la enfermedad entre el personal sanitario, la falta de datos acerca de la eficacia del tratamiento clásico con penicilina inyectable y la necesidad de desarrollar esquemas terapéuticos simplificados o investigar en nuevos tratamientos antibióticos, en especial de administración oral.
Actualmente hay una enorme brecha de conocimiento entorno a la información epidemiológica fiable sobre la enfermedad. Ciertamente, sabemos poco acerca de la incidencia en los tres países melanesios, donde la enfermedad es altamente endémica, Papúa Nueva Guinea (PNG), Islas Salomón y Vanuatu. En las Islas Salomón y Vanuatu, las cifras de incidencia son muy altas lo que demuestra que el pián es una enfermedad frecuente y ampliamente extendida, pero sabemos que el diagnóstico no es muy fiable. Esto nos lleva al siguiente punto: ¿Cuáles son los criterios diagnósticos del pián?
En general, la historia natural de la enfermedad en la época actual, donde la bacteria es objeto de presión antibiótica inadecuada, no es muy clara. Algunos autores han escrito que el pián parece presentar manifestaciones “atenuadas” en las Islas Salomón y Vanuatu. Afirman que la afectación ósea en el pián es poco frecuente, lo que implica que el pián es una enfermedad leve que no requeriría esfuerzos para su eliminación. Sin embargo, el primer trabajo de esta tesis describe la epidemiología del pián en la Isla de Lihir (Papúa Nueva Guinea) y muestra una alta tasa de úlceras primarias clásicas (casi el 60% de casos) y una afectación significativa del hueso y periostio (más del 15%) que sugiere que la "atenuación" no es un tema importante.
Cuando nos fijamos en los criterios diagnósticos, únicamente signos y síntomas todavía se utilizan en muchas áreas para el diagnóstico de la enfermedad. Esta confianza en los hallazgos clínicos fue el resultado de la dificultad de realizar pruebas serológicas en las zonas remotas. Hoy en día, las pruebas serológicas rápidas son simples, rápidas, económicas y útiles para orientar la confirmación de los casos. El diagnóstico clínico del pián es complicado debido a que sus manifestaciones pueden ser inespecíficas. Así, es posible, que una proporción significativa de los casos de pián puedan haber sido falsamente diagnosticados. En el primer artículo, presentamos que, en nuestra experiencia, sólo el 60% de los casos con sospecha clínica de pián fueron finalmente confirmados por pruebas serológicas. Por lo tanto, un diagnóstico adecuado del pián requiere la interpretación de los hallazgos clínicos con referencia a los resultados de laboratorio y la historia epidemiológica de los pacientes.
Las pruebas serológicas en el pián no sólo son importantes para el diagnóstico de la enfermedad, también son muy útiles en la definición de curación después del tratamiento. En la prueba de la Reagina plasmática rápida (RPR) los títulos deben descender a los 6-12 meses, llegando a ser negativa en menos de 2 años. El segundo artículo de esta tesis combina un enfoque clínico / serológico para evaluar la respuesta a bencilpenicilina benzatina, e identifica una tasa de fracaso terapéutico del 20% a los 12 meses del tratamiento. Esto podría estar relacionado con resistencia al fármaco antimicrobiano, o bien indicar una re-infección por re-exposición. La distinción entre la re-infección y la resistencia verdadera al tratamiento es difícil, pero estos fracasos terapéuticos son preocupantes. En este artículo se describe un modelo multivariante realizado para identificar los factores determinantes del fracaso terapéutico. El riesgo de re-infección causado por el contacto repetido con otros niños infectados parece ser un predictor fundamental de fracaso. También es un factor de riesgo, los títulos basales bajos (< 1:32) de RPR. Este último factor podría estar relacionado con la mayor dificultad para resolver infecciones crónicas (en estadio secundario), habitualmente acompañadas de títulos bajos.
Con la enfermedad de pián re-emergiendo, el desarrollo de nuevas estrategias contra la infección para hacer más fácil los esfuerzos de erradicación es esencial. La penicilina inyectable sigue siendo eficaz, pero el tratamiento con un fármaco por vía oral que pueda ser fácilmente administrado a gran escala es el método preferido para el tratamiento, prevención y finalmente eliminación en todas las regiones endémicas del mundo. Hasta la fecha, no ha habido estudios que comparen directamente la eficacia de la penicilina con cualquiera de los agentes alternativos en el tratamiento de las treponematosis no venéreas.
El cuarto artículo de esta tesis ha demostrado que una dosis única de azitromicina por vía oral no es inferior a la bencilpenicilina benzatina intramuscular, para el tratamiento del pián en niños en Papúa Nueva Guinea. En un ensayo abierto, aleatorio, el 96% de los pacientes tratados con azitromicina estaban curados a los 6 meses de seguimiento, al igual que el 93% en el grupo de bencilpenicilina benzatina. Las perspectivas de finalmente erradicar el pián son ahora mayores, mediante el uso de una dosis única de azitromicina oral en campañas masivas de tratamiento. El tratamiento masivo con azitromicina ha sido ampliamente utilizado para el control del tracoma, que, al igual que el pián es una enfermedad de comunidades rurales pobres de países en desarrollo. También se ha utilizado de una manera más limitada para controlar el granuloma inguinal y brotes de sífilis venérea. En general, el uso de azitromicina ha demostrado ser seguro, y de hecho ha habido beneficios inesperados de salud en algunos programas.
La eliminación del pián y la filariasis linfática en las Islas del Pacífico Sur se considera ahora biológicamente factible y operacionalmente alcanzable. El Programa Global para
Eliminar la Filariasis Linfática (GPELF) se ha expandido rápidamente para alcanzar la meta de eliminación en el año 2020. Por otro lado la estrategia para eliminar el pián es nuevamente centro de atención. Además, dado que los seres humanos infectados son la única fuente de la enfermedad, su eliminación podría lograrse en un plazo relativamente corto.
El quinto artículo de la tesis revisa de forma integral el tratamiento con antimicrobianos y las estrategias de eliminación contra el pián. Con el fin de controlar el pián hasta la erradicación, se propone pasar de la penicilina a la azitromicina, y el uso de campañas de tratamiento masivo de toda la población en todas las comunidades endémicas. Además, para asegurar que todos los casos son encontrados y tratados, serán necesarias medidas estrictas de seguimiento y tratamiento masivo selectivo hasta llegar al objetivo de cero casos clínicos. Es importante destacar que el principio de interrupción de la transmisión se debe probar en estudios piloto, incluyendo estudios de prevalencia, para monitorizar el impacto de la intervención, y también la valoración de resistencia a macrolidos, que en nuestra opinión, serán herramientas fundamentales que nos guíen en el camino hacia una eliminación sostenible
La filariasis linfática (FL), causada por el nematodo Wuchereria bancrofti, es otro de los grandes problemas de salud pública en los países de la Melanesia. Un curso de MDA anual, durante cinco años, es la estrategia que la OMS recomienda para eliminar la FL. Este enfoque tiene como objetivo suprimir la microfilaremia en los individuos infectados y disminuir los niveles de infección por debajo de un umbral que conduzca a la interrupción de la transmisión. Sin embargo, trabajo teórico y experiencia práctica clínica han puesto de relieve cómo la diversidad ecológica, entre diferentes regiones endémicas, puede resultar en que los umbrales de eliminación varíen en diferentes comunidades. Esto significa que la duración requerida podría ser diferente para diferentes áreas. Algunas variables que han sido previamente identificadas como potenciales determinantes en el resultado de un Programa para la eliminación de FL (PELF) son la prevalencia basal de infección por filariasis, la densidad de vectores (mosquitos) o la cobertura del tratamiento en la población.
El último artículo de esta tesis, proporciona datos sobre el impacto de un PELF de cinco años en PNG. Los resultados obtenidos apoyan la estrategia descrita para las zonas con baja a moderada tasas de transmisión en regiones donde mosquitos anofelinos transmiten la infección (pe. Melanesia, África). Medidas adicionales o períodos más largos de tratamiento pueden ser necesarios en áreas con una alta tasa de transmisión.
La experiencia adquirida en la Isla de Lihir en los programas de tratamiento masivo durante las campañas para la eliminación de la filariasis, será muy valiosa en la aplicación de una estrategia piloto para el control del pián. Además, en un futuro próximo podría ser importante vincular los programas para el control del pián con otros programas de tratamiento masivo (por ejemplo, filariasis) para aumentar la eficiencia y reducir los costos. El plan para la eliminación de la filariasis linfática en PNG fue aprobado como proyecto piloto en 2005 en la provincia de Milne Bay. El programa todavía tiene que ser extendido a un total de 20 provincias en el país, donde la filariasis es endémica. En este contexto, un enfoque integrado para el control de enfermedades tropicales olvidadas podría representar una importante solución global de salud pública en PNG.
Poco se ha logrado en la última década en enfermedades tropicales desatendidas. Ahora estamos en una buena posición para traducir los frutos de nuestra investigación en políticas de salud. Durante una consulta celebrada en la sede de la OMS en Ginebra el pasado mes de marzo, ya se ha esbozado una nueva política de eliminación para el pián que toma como pilar el tratamiento con azitromicina. La intención de la OMS es que una última campaña global debe permitir llegar a cero casos de pián en 2017, y la posterior certificación de la interrupción de la transmisión en todo el mundo en el año 2020.
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Capacidade instalada para pesquisa científica sobre Leishmanioses no Brasil, 2004 a 2008 / Installed capacity for scientific research on Leishmaniasis in Brazil, 2004-2008Tenorio, Marge [UNIFESP] 29 September 2010 (has links) (PDF)
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Previous issue date: 2010-09-29 / As Leishmanioses são classificadas pela OMS como uma das dez doenças negligenciadas tropicais (DNT), as quais apresentam alta incidência, atingem segmentos empobrecidos da população e não obtêm visibilidade social, portanto o investimento em diagnóstico, terapêutica e imunização é precário. As Leishmanioses fazem parte das doenças tropicais em expansão e não existem mecanismos adequados para sua prevenção e controle. Representam um problema de saúde pública mundial: 88 países apresentam pelo menos uma das trinta espécies de Leishmania e 350 milhões de indivíduos estão expostos à contaminação. Em algumas espécies, a letalidade das Leishmanioses pode alcançar 100% em pacientes sem tratamento. Diante desse quadro, realizou-se uma investigação com o objetivo de identificar o perfil da produção científica brasileira sobre o tema das Leishmanioses, no período 2004-2008, a fim de subsidiar o processo de formulação de políticas e tomada de decisões da gestão governamental, no tocante ao fomento à pesquisa em saúde nessa área do conhecimento. A pesquisa se refere a um estudo descritivo, elaborado com emprego da análise bibliométrica e da pesquisa documental. A Bibliometria consiste em um conjunto de leis e princípios empíricos que compõem os fundamentos teóricos da Ciência da Informação. A análise bibliométrica compreendeu a consulta, coleta e recuperação de informações quantitativas, em bases de dados da ciência da saúde no Brasil, seguida da organização dos dados coletados, sistematização em categorias de indexação, registro da coleta em banco de dados Excel e análise interpretativa das informações científicas e tecnológicas obtidas. A pesquisa documental constou de coleta e análise de dados em acervos institucionais de setores do órgão governamental federal de saúde. Em todas as bases consultadas, foram localizadas 749 publicações, produzidas no período 2004-2008 sobre o tema das Leishmanioses, das quais 521 atenderam aos critérios de inclusão. Foram publicados 415 artigos científicos por pesquisadores brasileiros em revistas indexadas, nacionais e internacionais. No diretório dos grupos de pesquisa da Plataforma Lattes, foi identificado o cadastro de 214 grupos dedicados ao tema. Receberam títulos nessa linha de pesquisa (Leishmanioses) 43 mestres e 44 doutores. A análise bibliométrica e documental permitiu identificar tendências de crescimento da produção científica brasileira sobre as Leishmanioses, no período 2004-2008, de grande relevância para a saúde pública, por tratar-se de doença negligenciada tropical. O Brasil detém o maior número de centros de pesquisa sobre Leishmanioses no mundo e atua em cooperação técnico-científica em âmbito nacional e internacional. Pode-se afirmar, portanto, que existe capacidade de médio porte instalada no país para a pesquisa sobre a doença. Além disso, foram identificados estudos em rede e multicêntricos, que podem favorecer a expansão e fortalecimento dos grupos voltados à pesquisa sobre Leishmaniose em âmbito nacional. Entende-se que seja oportuna a indução de ações e políticas públicas de fomento à pesquisa sobre estudos clínicos de fases I, II e III e sobre desenvolvimento tecnológico, a fim de propiciar o incremento do diagnóstico e tratamento das Leishmanioses no país. / The Leishmaniasis are classified by WHO as one of ten tropical neglected diseases (NTD), which have high incidence, affecting impoverished segments of the population and do not get social visibility, so the investment in diagnostic, therapeutic and immunization are poor. The Leishmaniasis is part of the tropical diseases in expansion process and there aren’t appropriate mechanisms for its prevention and control. They represent a public health problem worldwide: 88 countries have at least one of the thirty species of Leishmania and 350 million individuals are exposed to contamination. In some species, the lethality of Leishmaniasis may reach 100% in untreated patients. Given this situation, we carried out an investigation to identify the profile of Brazilian scientific literature on the subject of Leishmaniasis in the period 2004-2008 in order to support the process of policy formulation and decision making of government administration, with regard to development of health research in this area of knowledge. The survey refers to a descriptive study with use of bibliometric analysis and documentary research. The Bibliometrics consists of a set of empirical laws and principles that form the theoretical foundations of information science. Bibliometric analysis included query, collection and recovery of quantitative information in the databases of health science in Brazil, then organization of the data collected, systematized into categories of indexing, record collection in Excel database and interpretative analysis of scientific and technological information obtained. The collection consisted of desk research and data analysis in institutional sectors of the federal government body health. In all of the following databases were located 749 publications produced in the period 2004-2008 on the theme of Leishmaniasis, of which 521 met the inclusion criteria. 415 scientific articles were published by Brazilian researchers in indexed journals, national and international. In the directory of research groups of the Lattes Platform, were identified from the register 214 groups dedicated to the theme. Received titles in this line of research (Leishmaniasis) 43 masters and 44 doctors. Bibliometric analysis and documentation identified growth trends of the Brazilian scientific production on Leishmaniasis, in the period 2004-2008, of great relevance to public health, because it is neglected tropical disease. Brazil has the largest number of research centers on Leishmaniasis in the world and serves on scientific-technical cooperation in national and international areas, so it can be stated that there is midsize capacity for research on the disease installed in the country. Identified studies in multi-center network can promote the expansion and strengthening of the groups directed to research on Leishmaniasis nationwide. It is understood that is desirable the induction of actions and policies to encourage research on clinical trials of phases I, II and III and on technological development in order to facilitate the increase in diagnosis and treatment of Leishmaniasis in the country. / TEDE / BV UNIFESP: Teses e dissertações
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Etude des mécanismes de résistance du moustique Aedes aegypti aux insecticides pyréthrinoïdes : Apports des nouvelles technologies de séquençage ADN à l’identification de nouveaux marqueurs de résistance. / Pyrethroid insecticides resistance mechanisms in the mosquitoe Aedes aegypti : next-generation sequencing technlologies for identifiying new resistance markers.Faucon, Frédéric 14 December 2015 (has links)
La résistance des moustiques aux insecticides pyréthrinoïdes (PYRs) menace les programmes de lutte anti-vectorielle à l'échelle mondiale. Chez le moustique Aedes aegypti, vecteur de la dengue et du Chikungunya, les principaux mécanismes causant cette résistance ont été identifiés. La résistance métabolique joue alors un rôle important et consiste en une biodégradation accrue de l'insecticide par des enzymes de détoxication. Néanmoins, les bases moléculaires de ce mécanisme restent méconnues. La plupart des gènes impliqués dans la résistance métabolique aux PYRs ont été identifiés par des approches transcriptomiques, mais les modifications génomiques à l'origine de leur sur-expression dans les populations résistantes ainsi que les modifications structurales des enzymes en lien avec la résistance restent méconnues. Cette thèse vise alors à utiliser les nouvelles approches de séquençage à haut débit (NGS) pour caractériser les mécanismes moléculaires de la résistance aux PYRs chez le moustique Ae. Aegypti. La première partie de la thèse présente une étude pilote RNA-seq menée sur des populations de laboratoire sélectionnées avec des insecticides. Cette étude a pour objectif d'évaluer les avantages des NGS pour l'étude des mécanismes de résistance chez les moustiques. Le rôle des enzymes de détoxication dans la résistance a ainsi été clairement confirmé. Plusieurs gènes codant pour ces enzymes apparaissent sur-exprimés dans les populations résistantes et un important regroupement de P450 montre une forte empreinte de sélection en lien avec la résistance aux PYRs. La seconde partie de la thèse présente une étude sur des populations naturelles échantillonnées sur divers continents. Cette étude combine les technologies d'enrichissement génomique et de DNA-seq afin d'étudier les variations génomiques liées à la résistance au PYR Deltaméthrine. La comparaison de la couverture de séquençage entre populations résistantes et sensibles a permis d'identifier des variations de nombre de copies (CNVs) de certains gènes de détoxication associées à la résistance à la Deltaméthrine. Des mutations non-synonymes fortement liées au phénotype de résistance ont également été mises en évidence. La comparaison de ces marqueurs de la résistance entre les différentes populations a révélé que les gènes/mutations associés à la résistance à la Deltaméthrine sont peu conservés entre continents, probablement à cause des différences de fond génétique des populations, de leur histoire démographique et des pressions de sélections. La troisième partie de la thèse décrit une étude par RNA-seq portant sur les mêmes populations naturelles, visant à croiser des données de transcriptomique (expression des gènes et polymorphisme des transcrits) avec les données génomiques générées par l'étude précédente. Plusieurs enzymes de détoxications ont été retrouvées sur-exprimées chez les populations résistantes en lien avec les CNVs précédemment identifiées. Des centaines de variations de polymorphisme ont été identifiées par DNA-seq dans les zones cis-promotrices des différents gènes étudiés. Parmi ces variations, plusieurs apparaissent associées à la sur-régulation d'enzymes de détoxication. Enfin, la comparaison des données de polymorphismes obtenues par DNA-seq et RNA-seq a permis d'étudier les phénomènes d'expression d'allèles spécifiques en lien avec la résistance. Cette étude confirme l'intérêt de croiser des données de transcriptomique et de génomique pour caractériser les bases moléculaires de la résistance aux insecticides. D'un point de vue général, cette thèse permet de mieux appréhender les mécanismes de résistance du moustique Ae. aegypti aux PYRs mais aussi d'identifier de nouveaux marqueurs de la résistance potentiellement utilisables pour développer de nouveaux outils moléculaires diagnostiques de la résistance sur le terrain. Ce travail met également en avant les apports des NGS pour l'étude fine des bases moléculaires de l'adaptation d'organismes modèles. / Mosquito control programs worldwide are increasingly threatened by resistance to pyrethroid insecticides (PYRs). In the dengue and chikungunya vector Aedes aegypti, the key resistance mechanisms include modifications in the protein targeted by insecticides (target-site mutations) and metabolic resistance, consisting in an increased insecticide biodegradation by so called detoxification enzymes. However, as opposed to target-site mutations, the molecular basis of metabolic resistance remains poorly understood. Most metabolic resistance genes have been detected by transcriptomic approaches based on their over-expressed in resistant populations, but genomic changes leading to these expression changes as well as structural changes in enzymes potentially involved in resistance remain unknown. In this context, this thesis aims at using next-generation sequencing approaches for characterizing PYR resistance mechanisms in the mosquito Ae. aegypti.The first chapter of this thesis describes a pilot study on laboratory insecticide-selected populations of Ae. aegypti. This study aims at investigating the benefits of next-generation sequencing for studying resistance mechanisms in mosquitoes. This study confirmed that detoxification enzymes play a key role in resistance, with several of them being over-expressed in resistant populations and a large cluster of cytochrome P450 genes showing a selection imprint associated with resistance to PYRs.The second chapter of this thesis describes a study conducted on natural mosquito populations from various continents. Combining genomic target enrichment (targeting about 800 genes potentially involved in resistance) and DNA-seq allowed unravelling genomic changes associated with resistance to the PYR deltamethrin. Comparing normalized sequencing coverage between resistant and susceptible populations identified significant copy number variations (CNVs) in several detoxification genes strongly associated to deltamethrin resistance. Non-synonymous mutations affecting detoxification enzymes associated to the resistance phenotype were also detected. Comparing resistance markers between populations from various continents revealed that genes/mutations associated with deltamethrin resistance are poorly conserved across continents, probably due to differences in the genetic background of populations but also differences in terms of demographic history and selection pressures.The third chapter describes an RNA-seq study performed on the same natural mosquito populations in order to cross-link transcriptomic data (gene expression and transcript polymorphism) with genomic data obtained from the previous study. Multiple detoxification enzymes were found over-transcribed in resistant populations linked with previously identified CNVs. Hundreds polymorphism variations were identified by targeted DNA-seq in cis-promoter regions of detoxification genes. Among them, several were associated with the upper-regulation of detoxification enzymes in resistant populations. Finally, cross-comparing polymorphism data obtain from DNA-seq and RNA-seq allowed investigating allele specific expression (ASE) events related to PYR resistance. Overall, this study confirmed the benefits of combining transcriptomic and genomic NGS approaches for studying the molecular basis of insecticide resistance.As a whole, this thesis not only contributed to better understand PYR resistance mechanisms in the dengue vector Ae. aegypti but also identified novel genomic markers of resistance opening the way for developing new molecular diagnostic to early detect and monitor resistance mechanisms in the field. This work also highlights the benefits of using NGS technologies for unravelling the molecular bases of adaptation in model organisms.
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Reducing the ‘Neglect’ in Neglected Tropical Diseases: A Review of the Debate surrounding the Effectiveness of Mass Deworming – A Case Study of Kenya –Brigitzer, Kim January 2016 (has links)
Neglected tropical diseases are parasitic and bacterial diseases mainly prevalent in developing countries affecting people living in poverty. The World Health Organization’s human rights-based approach emphasizes the “prevention, control, elimination and eradication of neglected tropical diseases” through the use of preventative chemotherapy, such as the mass administration of deworming drugs to improve people’s health.This research paper will take a deeper look at how WHO has been communicating NTDs to make them less ‘neglected’ and how the NTD discourse has been shaping development organizations’ action. In addition, it aims to investigate how successful mass deworming has really been in terms of the recent debate.This study is using a combination of a discourse analysis and qualitative interviews in order to investigate how the NTD discourse and recent initiatives by international organizations have contributed to making NTDs less neglected. It deconstructs representations of the ‘Other’ – the superiority of the ‘West’ over the ‘Rest’ – in relation to the NTD discourse and its inherent power structures. Discourses are analyzed to identify power relations between governments, development organizations, pharmaceutical industries, and recipients of deworming drugs as part of Kenya’s 2013 deworming campaign.The results showed that the NTD discourse has helped raise awareness for NTDs. NTDs and their debilitating effect on populations have been better and more widely communicated, making them less ‘neglected’. WHO and other development organizations’ actions have contributed to making NTDs more visible and have given NTDs higher priority on the global health agenda. Findings from this research study revealed that the ongoing debate has not had a negative impact on international funding. More research and development of a vaccine against NTDs is needed to find more ways to tackle these devastating diseases.
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Reducing Usage Barriers : Employing AI-based Image Analysis in a Diagnostic PlatformSvensson, Viktoria, Lindberg, Stina January 2024 (has links)
Neglected Tropical Diseases (NTDs) currently affect approximately 1.6 billion people worldwide, predominantly impacting populations with limited resources and access to healthcare. The study employs an interdisciplinary approach within the field of diagnostics and information technology to investigate the application of computer vision in developing diagnostic tools with the aim of fighting the spread of neglected tropical diseases (NTDs). By leveraging advancements in the field of computer vision, the research seeks to enhance diagnostic accuracy and efficiency by lowering the usage barriers of the diagnostic tool. The research explores the feasibility of using computer vision to differentiate between various characteristics of images generated by a microscope in a diagnostic setting. The aim is to determine the most suitable method for image analysis in the diagnostic setting, comparing conventional image processing techniques, such as image filtering and color models, with Artificial Intelligence (AI)-based methods. The results revealed that the complexity of the images rendered conventional image filters and color models inadequate, highlighting the necessity of alternative methodologies, such as AI. The findings suggest that AI-based approaches are better suited to handle the intricate details and variations present in the images captured by the microscope by offering more accurate and reliable diagnostic capabilities. However, the model trained on single-labeled images required an additional technique for addressing images containing multiple characteristics, namely thresholding. Thresholds were essential for effecting the model's final prediction to suit the specific use case. By implementing thresholds, the model could, to a higher degree, distinguish between overlapping features within the images, ensuring more accurate classification and enhancing overall performance in the diagnostic setting. The final result presents a promising AI model that has the potential to reduce the usage barriers of the diagnostic tool. Hence, this study represents a small step in the right direction toward the larger goal of fighting the spread of neglected tropical diseases.
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Dengue diagnostics and therapeutic interventions in Viet NamTricou, Vianney M. January 2011 (has links)
Dengue is a major public health problem that affects tens of millions of people annually in tropical and sub-tropical countries. This acute viral infection happens to be severe and even life threatening but there is still no available drug or vaccine. Previous studies have noted early higher viral burden in patients who develop more severe symptoms suggesting that administration of a potent and safe antiviral may prevent progression to severe dengue. To verify this hypothesis, we have conducted the first RCT directed towards reducing the viral burden in vivo by administrating chloroquine (CQ), a cheap and well-tolerated drug that inhibits DENV in vitro with concentrations achievable in vivo, to 307 Vietnamese adults with suspected dengue (257 of them were laboratory-confirmed cases). Unfortunately, we did not see an effect of CQ on the duration of infection. However in patients treated with CQ, we observed a trend towards a lower incidence of severe forms. We did not find any differences in the immune response that can explain this trend. We also found more adverse events, primarily vomiting, with CQ. In addition, we have explored the relationships between clinical features, antibody responses and virological markers in these patients. We found that the early magnitude of viremia is positively associated with disease severity and there are serotype dependent differences in infection kinetics. We found as well that DENV was cleared faster and earlier in patients with secondary infections. To complete this study, we have also evaluated 2 rapid lateral flow tests for the diagnosis of dengue in a panel of plasma samples from 245 RT-PCR confirmed dengue patients and 47 with other febrile illnesses. Our data suggest that the NS1 test component of these tests are highly specific and have similar levels of sensitivity (~60%). Both NS1 assays were significantly more sensitive for primary than secondary dengue. The IgM parameter in the SD Duo test improved overall test sensitivity without compromising specificity. All these findings are of major importance for further anti-viral drug testing.
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Síntese e avaliação biológica de selenoaminas heteroarílicas : uma nova proposta quimioterápica para maláriaSilva, Gabriela Dias da January 2014 (has links)
Orientador: Prof. Dr. Rodrigo Luiz Oliveira Rodrigues Cunha / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência & Tecnologia - Química, 2014. / Errata: Folha 4, linha 20. Onde se lê "Figura 1. Imagem de microscopia evidanciando o anel trofozoíta (no centro em destaque), leia-se Figura 1. Imagem de microscopia evidanciando o anel trofozoíta (no centro, em destaque). Fonte: https://pt.wikipedia.org/wiki/ficheiro:Plasmodium_ovale_01.png / As doenças tropicais negligenciadas (DTNs), características de regiões menos desenvolvidas do planeta com baixos níveis de escolaridade, habitação e saneamento básico estão sujeitas às opções terapêuticas limitadas e ineficientes. A cada ano, cerca de 250 milhões de casos de malária são diagnosticados e aproximadamente um milhão de pessoas morre desta doença.
A baixa eficácia, elevada toxicidade e a emergência de cepas de parasitas resistentes à fármacos, são fatores que determinam a necessidade da síntese de novos fármacos e programas de investimentos e inovação em pesquisa e desenvolvimento (P&D).
A proposta de compostos híbridos ou funcionalização de moléculas, como também pode ser
chamada, é uma abordagem bem estabelecida para síntese de fármacos. Moléculas híbridas ganham destaque com o uso em várias áreas terapêuticas, tais como inflamação, alergia, depressão, propostas quimioterápicas contra o câncer e parasitemia.
Recentemente as atividades biológicas de compostos de Selênio têm recebido crescente
atenção, em especial os derivados hipervalentes de Selênio (IV) que têm sido estudados por nosso grupo de pesquisas como inibidores de cisteína peptidases. O merecido destaque dos compostos de Selênio hipervalentes, avaliados como inibidores enzimáticos aumentam as chances de encontrar inibidores mais eficientes e seletivos para enzimas envolvidas em infecções parasitárias. Neste sentido, esse trabalho propôs a junção de duas propriedades químicas que atuam contra o desenvolvimento do Plasmodium falciparum (protozoário responsável pela Malária): a inibição da heme-polimerase através da ação de sistemas hetrocíclicos nitrogenados (como bases fracas), e a inibição de cisteína peptidases com a atuação das selenuranas, as quais reduzem o efluxo da droga em cepas resistentes a outros fármacos. Os compostos sintetizados foram submetidos a testes biológicos para a avaliação de seu potencial como quimioterápicos para a malária. Os compostos foram eficientes na inibição do desenvolvimento dos parasitas in vitro e mostraram interferir na homeostase celular. Além disso, não causaram hemólise e nem diminuição significativa da viabilidade de células endoteliais. Juntos, os resultados obtidos mostram que esses compostos são potenciais candidatos para desenvolvimento de novos fármacos, uma vez que é letal ao parasita e contém os benefícios de composto híbrido. / Neglected tropical diseases (NTDs), typical of less developed regions of the world with low
levels of education, habitation and sanitation are subject to limited and ineffective treatment options. Each year, about 250 million cases of Malaria are diagnosed and about 1 million people die of this disease. The low efficacy, high toxicity and the emergence of chloroquine resistant in Plasmodium falciparum strains are factors that determine the necessity for synthesis of new drugs and investments and innovations programs in research and development (R&D). The proposed of hybrid compounds, or they are also called functionalization of molecules, is a well-established approach to synthesis of drugs. Hybrid molecules are highlighted on use in various therapeutic areas such as inflammation, allergy, depression, proposals for cancer and parasitosis chemotherapy.
Recently the biological activities of selenium compounds has received great attention,
particularly hypervalent derivatives of selenium (IV) that it has been studied by our research group as inhibitors of cysteine peptidases. The worth prominence of hypervalent selenium compounds evaluated as enzyme inhibitors, which increase the chances of finding more efficient and selective for enzymes involved in parasitic infections inhibitors .
In this way, this work proposed the addition of two chemical properties that act against the
development of Plasmodium falciparum (protozoan responsible for Malaria). Inhibition of heme polymerase by way of the action of amino groups (such as weak bases), and inhibition of cysteine peptidases with the performance of selenuranes reduces the efflux of drug in resistant strains to other drugs. The synthesized compounds were subjected to biological evaluation of their potential as chemotherapeutic agents for Malaria tests. The compounds were effective in inhibiting the development of parasites in vitro and interference on cellular homeostasis. In addition, didn¿t cause hemolysis or a significant decrease in viability of endothelial cells. Together, the results show that these compounds are good candidates for development of new drugs since it is lethal to the parasite, does not harm the host and has the benefits of a hybrid compound.
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Maladies infectieuses, écosystèmes et pauvreté : le cas de l'ulcère de Buruli au Cameroun / Infectious diseases, ecosystems and poverty : the case of Buruli ulcer in CameroonGarchitorena Garcia, Andrés 11 December 2014 (has links)
Comprendre les rétroactions entre les maladies infectieuses, la structure des écosystèmes et le développement économique est nécessaire pour alléger le fardeau des maladies tropicales négligées. Ce groupe d'infections parasitaires, virales, et bactériennes est étroitement associé à des conditions géographiques, environnementales, sanitaires et économiques particulières aux régions tropicales. A travers l'étude de l'ulcère de Buruli, une maladie émergente et négligée associé à une morbidité et handicap très importants dans des régions tropicales, ce travail de thèse s'intéresse aux interactions complexes entre ces différents composants des systèmes épidémiologiques. Combinant un travail de terrain important pour la collecte des données environnementales avec une approche de recherche multidisciplinaire, cette thèse vise à améliorer notre compréhension des différents aspects de l'écologie et de l'épidémiologie de cette maladie infectieuse. Notamment, la dynamique de son agent pathogène, M. ulcerans, est caractérisée pour un large éventail d'écosystèmes et communautés aquatiques au Cameroun, permettant d'identifier les facteurs environnementaux permettant sa propagation. En outre, nous évaluons la transmission de l'agent pathogène de l'environnement à l'homme et l'impact de la maladie sur le développement économique des populations endémiques. Ainsi, ce travail montre comment les dynamiques écologiques, épidémiologiques, environnementales et économiques interagissent de concert, mettant en évidence de façon criante le besoin d'une telle approche interdisciplinaire dans l'étude des maladies tropicales négligées. / Understanding the feedbacks between infectious diseases, ecosystem structure and economic development is necessary to alleviate the burden of Neglected Tropical Diseases. This group of parasitic, viral, and bacterial infections is closely associated with particular geographical and environmental conditions mainly present in the tropics, thriving under conditions of poverty, inefficient sanitation and malnutrition. This PhD thesis works through the case study of Buruli ulcer, an emerging and neglected infectious disease associated with a great morbidity and disability burden in tropical regions. Relying on an extensive environmental field survey and a multidisciplinary research approach, this PhD attempts to gain a better understanding of different aspects of the ecology and epidemiology of Buruli ulcer. Notably, the dynamics of its pathogen, M. ulcerans are characterized for a wide range of freshwater ecosystems and aquatic communities in Cameroon, and the environmental drivers of M. ulcerans presence are investigated. Furthermore, we assess the transmission of the pathogen from the environment to humans and the impact of the disease on the economic development of endemic populations. Thus, this work shows how the interplay between ecological, epidemiological and economic dynamics interact together and calls for an urgent need to apply such inter-disciplinary approach to decrease the burden of neglected tropical diseases.
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Identificação e avaliação imunológica de potenciais epítopos de linfócitos T CD4+ e T CD8+ no proteoma de Leishmania (Viannia) braziliensisSILVA, Rafael de Freitas e 06 September 2016 (has links)
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Previous issue date: 2016-09-06 / As leishmanioses são doenças causadas por protozoários do gênero Leishmania e
estão presentes em 98 países e territórios e possuem incidência anual de 2
milhões de casos. A Leishmania (Viannia) braziliensis (L.V. braziliensis) é uma das
principais espécies causadoras da leishmaniose cutânea (LC) no Brasil. Apesar
disso, ainda não há uma vacina segura e eficaz para ser utilizada em seres
humanos. Nesse sentido, o objetivo deste trabalho foi identificar no proteoma
predito de L.V. braziliensis, potenciais epítopos de linfócitos T e avaliá-los por meio
de ensaios imunológicos. No primeiro capítulo, o proteoma predito de L.
braziliensis foi comparado ao de outras espécies e analisado quanto a presença de
epítopos. Nessa etapa foram encontrados epítopos derivados de mais de 8 mil
proteínas conservadas entre diferentes espécies de Leishmania. Os epítopos
foram clusterizados e então utilizados para etapa de docagem molecular com
estruturas de MHC I e MHC II depositadas no Protein Data Bank. A docagem
molecular resultou em epítopos peptídicos de 15 aminoácidos com alta afinidade
de ligação às moléculas de MHC I e MHC II. Os 10 melhores resultados foram
então sintetizados e avaliados, in vitro, quanto à capacidade de estimular a
proliferação de células mononucleares do sangue periférico (PBMC) de indivíduos
com LC após o tratamento (PT). Os resultados indicaram que 50% das moléculas
testadas apresentaram capacidade de estimular, significativamente (p<0,05), a
proliferação celular quando comparado às células de indivíduos saudáveis que não
vivem em região endêmica para LC. No segundo capítulo, os peptídeos foram
avaliados quanto à capacidade de estimular a proliferação de PBMC de indivíduos
com LC em sua fase ativa (AD) e indivíduos moradores de área endêmica para LC
resistentes à infecção (RT). Em paralelo, quantificou-se a expressão do fator de
transcrição T-bet em PBMC de indivíduos PT, e citocinas dos perfis Th1, Th2 e
Th17 foram mensuradas no sobrenadante de cultura das células de indivíduos PT
e AD. Os resultados demonstraram altos níveis de proliferação nas células do
grupo RT para todos os peptídeos testados. Além disso, níveis significativos de Tbet
foram observados em linfócitos T CD4+ e CD8+ após estímulo com seis
peptídeos. Níveis significativos de IFN-γ, TNF e IL-6 foram observados no
sobrenadante das células do grupo PT com quatro dos peptídeos testados. Altos
níveis dessas citocinas também foram encontrados no sobrenadante do grupo AD.
No terceiro capítulo, avaliou-se o efeito dos peptídeos sobre células dendríticas de
medula (BMDC) murinas, produção de citocinas de sobrenadante, e células
dendríticas esplênicas murinas após estímulo com os peptídeos. Verificou-se altos
níveis de MHC II e CD40 em uma subpopulação de BMDC estimuladas com as
moléculas e altos níves de TNF e IL-6 após 48h de estímulo. Para as células
esplênicas, foram observados altos níveis de subpopulações celulares
expressando CD11b+, IL-12p70+, CD205+ e CD11b+ após estímulo com o peptídeo
que teve o melhor resultado in silico. Por fim, os resultados indicam o grande
potencial imunogênico que os epítopos identificados apresentam, o que dá suporte
ao desenvolvimento futuro de abordagens vacinais. / The leishmaniasis are diseases caused by protozoans from the genus
Leishmania which are present in 98 countries and territories, with an annual
incidence of 2 million cases. Among the other species, Leishmania (Viannia)
braziliensis is the main specie implicated with cutaneous leishmaniasis (CL) in
Brazil. Besides that, there is no safe and effective vaccine against leishmaniasis
to be applied in humans. In this context, the aim of this work was to identify in
the predicted proteome of L. braziliensis potential CD4+ and CD8+ T cell
epitopes and evaluate them by immunological assays. In the first chapter, the
predicted proteome of L. braziliensis was compared with other species and
analyzed for the presence of epitopes. In this step, epitopes from more than
8,000 conserved proteins were found among other species of Leishmania. The
epitopes were clustered and then used for the molecular docking with MHC I
and MHC II structures deposited in the Protein Data Bank. This approach
resulted in 15 aminoacids peptide epitopes with high binding affinity for MHC I
and MHC II. The 10 best results were synthesized and evaluated in vitro for
their capacity to stimulate the proliferation of peripheral blood mononuclear cells
(PBMC) of individuals with CL post treatment (PT). The results have shown that
50% of the tested molecules had the capacity to stimulate, significantly
(p<0.05), cell proliferation when compared with cells of healthy individuals living
in non-endemic regions. For the second chapter, the peptides were evaluated
for their capacity to stimulate the proliferation of PBMC from CL individuals with
active disease (AD) and of individuals resistant to infection (RT) living in
endemic region. In parallel, the T-bet transcription factor expression was
quantified in PBMC of PT individuals, and cytokines from the Th1, Th2 and
Th17 profiles were measured in culture supernatant of PT and AD groups. High
levels of cell proliferation in the RT group were demonstrated for all peptides
tested. Moreover, significant levels of T-bet in CD4+ and CD8+ T cells were
verified after stimulation with six peptides. For IFN-γ, TNF and IL-6, significant
levels were detected in the supernatant of cultures from the PT group with four
peptides tested. High levels of these same cytokines were also present in the
supernatant of AD group. In the third chapter, the peptide effects over murine
bone marrow dendritic cells (BMDC), the production of cytokines in the
supernatant and murine spleen dendritic cell subsets were evaluated after
peptide stimuli. High levels of MHC II and CD40 were verified for stimulated
BMDC and high levels of TNF and IL-6 after 48h of stimuli. For spleen cells,
high levels of cells expressing CD11b+, IL-12p70+, CD205+ e CD11b+ were
observed after stimulation with the peptide which showed the best in silico
result. In conclusion, the results indicate the great immunogenic potential of the
identified peptides and support the further development of vaccine approaches
using those molecules.
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Dengue and development: a critical political ecologyMulligan, Kate 04 1900 (has links)
<p>Policies for the control of dengue fever often construct the mosquito-borne virus as a disease of poverty, and call for disease control through “development” to meet the needs of poor populations and impoverished or unsanitary spaces. However, exceptions to the narrative of a rich/poor dengue divide persist in non-poor urban environments across the world. One example is Malaysia's new administrative capital city of Putrajaya – a wealthy and centrally planned new city with among the highest rates of dengue in the country.</p> <p>This dissertation drew on theories of ecosocial epidemiology and urban political ecology to investigate and contextualize the geography of dengue and development in Putrajaya. Key informant interviews and critical discourse analysis found that infectious disease control fell well below other urban priorities for the city, and that globally dominant dengue control strategies targeted toward poor populations were inappropriately transferred to Putrajaya's non-poor local environment. A systematic review of the research literature found no clear evidence showing an association between dengue and conditions of poverty. These findings challenge conventional thinking by policy makers about epidemiological transition and the social determinants of health.</p> <p>The dissertation addresses the dearth of research into the world's neglected tropical diseases (NTDs); in particular, gaps in our understanding of the biopolitical and socioecological contexts (sites of urban governance, sites of health policy development and implementation, and sites of academic research) in which policies for NTDs like dengue are determined, enacted and justified. The dissertation further identifies non-poor urban environments – in particular those undergoing rapid development, such as Putrajaya – as key spaces for future geographic and political ecological research related to epidemiological transition, economic development and the social and environmental determinants of health.</p> / Doctor of Philosophy (PhD)
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