• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 43
  • 5
  • 3
  • 3
  • 1
  • 1
  • Tagged with
  • 61
  • 24
  • 14
  • 13
  • 9
  • 6
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
31

Desenvolvimento e controle de qualidade de micropartículas poliméricas contendo praziquantel para o tratamento pediátrico da esquistossomose

Machado, Jaison Carlosso January 2016 (has links)
A esquistossomose é uma doença parasitária aguda e crônica causada por vermes sanguíneos (vermes nematoides) do gênero Schistosoma. O homem contrai a esquistossomose através da penetração ativa da cercaria na pele. A importância do tratamento desta enfermidade consiste não só no fato de curar a doença ou diminuir a carga parasitária dos pacientes, bem como impedir sua evolução para formas mais graves. Para o tratamento da esquistossomose o fármaco de escolha é o praziquantel; isso se deve ao seu amplo espectro, sua eficácia, segurança e a relação custo/tratamento. A única forma farmacêutica disponível no Brasil é o comprimido, na dose de 600 mg, a qual pode ser subdividida em quatro partes de 150 mg, a fim de facilitar o ajuste de dose. No entanto, no momento da subdivisão dos comprimidos ocorre o rompimento do revestimento. Este fato acaba levando a uma exposição do fármaco e, consequentemente, de seu sabor amargo. Esta característica dificulta a administração do medicamento, principalmente na população infantil, prejudicando o tratamento e o controle da doença. Uma alternativa para este problema é o desenvolvimento de sistemas poliméricos microparticulados que associados ao fármaco impediriam o contato direto com as papilas gustativas e assim promoveriam uma melhoria na palatabilidade. Para isso utilizou-se a técnica modificada de deposição interfacial do polímero pré-formado seguido de secagem por aspersão. Três matrizes poliméricas, com diferentes características de liberação foram utilizadas, Eudragit RL 100 – liberação tempo dependente e Eudragit E100 e L30D-55 – liberação pH dependente. Além disso, dois tipos de sistemas carreadores do fármaco foram preparados, microcápsulas e microesferas poliméricas. Estes sistemas obtidos foram avaliados e caracterizados a fim de eleger a melhor proposta de formulação visando o mascaramento do sabor do fármaco. De acordo com os resultados obtidos selecionou-se um sistema composto por microcápsulas formadas a partir do polímero L30D-55. A partir de então inseriu-se este sistema na forma farmacêutica pó para suspensão oral, onde diferentes propostas de formulações, contendo dois edulcorantes auxiliares, aspartame e sacarina, separadamente, e seus respectivos placebos foram avaliadas através de um método in vitro para a determinação do sabor, a língua eletrônica ou sensor gustativo. As diferentes formulações avaliadas apresentaram capacidade em mascarar o sabor desagradável do fármaco e, assim resultam em uma promissora alternativa para o aumento da adesão por parte dos pacientes à terapêutica, principalmente para crianças, em virtude da facilidade de administração, do ajuste da dose em função da massa corpórea e ao sabor muito mais agradável ao paladar infantil. / Schistosomiasis is a parasitic disease acute and chronic caused by blood worms (nematodes worms) of the genus Schistosoma. Man acquires schistosomiasis through the active penetration of the worms in skin. The importance of treatment of this disease is not only the fact of curing the disease or decreases the parasite load of patients, well as prevent progression to more severe forms. For the treatment of schistosomiasis praziquantel is the drug of choice, this is due to its wide spectrum, its efficacy, safety and the relation cost / treatment. The single dosage form available in Brazil is tablet at a dose of 600 mg, which can be subdivided into four parts of 150 mg to facilitate dose adjustment. However when the subdivision of the tablets occurs the disruption of the coating. This fact provides a drug exposure and consequently of its bitter taste. This characteristic complicates the administration of the drug mainly in children, affecting the treatment and control of disease. An alternative for this problem is the development of microparticulate polymeric systems which associated with the drug would prevent direct contact with the taste buds and thus promote an improvement in palatability. For this was used a modified technique interfacial deposition of preformed polymer followed by spray drying. Three polymer matrices with different release characteristics have been used, Eudragit RL 100 – time dependent release, and Eudragit E100 and L30D-55 – pH dependent release. Furthermore, two types of drug carrier systems have been prepared, polymeric microspheres and microcapsules. These systems obtained were evaluated and characterized in order to select the best proposal formulation aimed at masking the taste of the drug. According to the results we selected a system comprising microcapsules formed from L30D-55 polymer. From then was inserted into this system in the pharmaceutical form, powder for oral suspension, where different proposals formulations containing two auxiliary sweeteners, aspartame and saccharin, separately, and their respective placebos were evaluated in an in vitro method for determining the taste, the electronic tongue. The different formulations tested presented excellent ability to mask the unpleasant taste of the drug and thus present an excellent alternative for increasing adherence to therapy, especially for children, because of the ease of administration, according on dose adjustment of body mass and the much more palatable to children's taste.
32

Účinek vybraných antiparazitik na motolice Trichobilharzia regenti / Effect of selected antiparasitic drugs on Trichobilharzia regenti

Lípová, Pavlína January 2012 (has links)
Praziquantel is a drug of choice for the treatment of schistosomiasis caused by human species of the genus Schistosoma. The effect of the drug on avian schistosomes is not completely known. Monensin is a drug used for the treatment of coccidiosis, and its effect on avian schistosomes is unknown. In the thesis, we studied the effect of these drugs on avian schistosome Trichobilharzia regenti. Under in vitro conditions, both drugs were effective after 6 hours of incubation. Praziquantel causes an extensive vacuolization of the whole body, while monensis treatment causes vacuolization of the anterior part of body. Higher concentration of praziquantel causes depolymerization of myofilaments and separation of surface membranes. Monensin did not impair muscles, but caused separation of tegumental layer from the basal membrane. Schistosomula in ducks were not killed by the drugs under in vivo conditions, but the worms were damaged by the drugs. Praziquantel caused vacuolization of the tegument and separation of membranes from the surface. Only vacuolization of the tegument occurred in schistosomula from ducks treated with monensin . No damage to the muscles was observed in the case of both drugs. Histological evaluation of the nerve tissue showed that thero no difference between treated and control duck....
33

Systematic review and meta-analysis of the effects of treatment and immunization against schistosomiasis

Fukushige, Mizuho January 2016 (has links)
Schistosomiasis is a water-borne parasitic disease of great public health importance mainly in sub-Saharan African countries. The majority of current control programmes use the antihelminthic drug praziquantel to reduce disease burden in endemic areas. Praziquantel treatment has been reported to accelerate the development of protective immunity against re-infection that otherwise takes years to develop. To date, there is no licensed vaccine for schistosomiasis in humans but an attenuated schistosome parasite vaccine has been tested in animal models. Employing systematic review and meta-analysis approaches, my PhD research has four main objectives relating to attenuated schistosome vaccine and praziquantel treatment: 1) to identify predictors that determine protection levels after treatment with attenuated Schistosoma mansoni vaccines in the mouse model, 2) to quantify the influence of host and schistosome parasite species on attenuated parasite vaccine efficacy, 3) to explore the direction of change (increase/decrease) in schistosome parasite-specific antibody isotypes after praziquantel treatment in humans, 4) to identify predictors of praziquantel efficacy in humans. My analyses revealed three factors that have an influence on the protection levels provided by attenuated schistosome parasite vaccines: increasing numbers of immunizing parasites had a positive effect on the levels of protection whereas increasing the radiation dose and the time to challenge infection had negative effects. Analyses showed that the attenuated schistosome vaccine has the potential to achieve protection levels as high as 79% after a single dose in mice. Alongside this, baboon studies consistently reported protective effects of attenuated schistosome vaccines against re-infection. These results show there is a high potential for an attenuated schistosome parasite vaccine to be effective in humans. A meta-analysis of the influence of praziquantel treatment on the direction of change in schistosome-specific antibody isotypes was conducted. The analysis revealed considerable variability in the antibodies’ direction of change among populations. The results also demonstrated an increase of anti-worm IgA and IgE in the majority of studies. These antibodies have been reported to have a protective effect against re-infection. The combination of age and infection intensity, and the number of days after treatment were identified as influential predictors for some antibody isotypes, but there was no single predictor that consistently affected all antibody isotypes in the same way. Praziquantel efficacy levels in humans were investigated and the analyses revealed that cure rates for schistosomiasis increase with praziquantel dose, and were affected by the identity of the schistosome parasite species (S. mansoni vs. S. haematobium) and the age of the participants (children: 0-19 years old vs. adults: ≥ 20 years old). There has been no clear efficacy level reduction over the treatment years (1979-2013) suggesting that praziquantel is still effective in the treatment of schistosomiasis despite concerns about possible resistance. The development of a schistosome vaccine will benefit from a closer investigation into the mechanisms through which protection is acquired in attenuated schistosome parasite vaccine studies showing high potential efficacy in animal models. Nevertheless, it will take time to develop a schistosome vaccine for human use. The uptake of the vaccine will be made even more challenging by the lack of adequate infrastructure in schistosomiasis endemic areas. In the meantime, close monitoring of praziquantel efficacy levels is necessary to confirm the effectiveness of schistosomiasis control in endemic areas.
34

Efforts toward the First Enantioselective Total Synthesis of Praziquantel and Synthetic Model Studies on Ecteinascidin 743 by Novel Aromatic C-H Insertion Methodology

Chen, Chiliu 18 March 2004 (has links)
The thesis is composed of three chapters. The aim of this thesis is to apply the novel dirhodium perfluorobutyrate-catalyzed intramolecular aromatic C-H insertion methodology to the enantioselective total synthesis of praziquantel and synthetic model studies on ecteinascidin 743, which belongs to the important tetrahydroisoquinoline family. The first introductory chapter deals with the biological significance and previous synthetic methodologies. Our novel methodology is based on dirhodium perfluorobutyrate-catalyzed intromolecular aromatic C-H insertion reaction, which is crucial in the pivotal carbon-carbon bond formation when constructing isoquinolone moiety, which is ubiquitous in numerous natural products of significant biological and pharmacological activities. The second chapter takes on the first enantioselective total synthesis of praziquantel, an antihelmintic drug. Praziquantel is used worldwide to treat schistosomiasis, which has tremendous impact on the global fight on this disease affecting 150 million people. We believe this is the first asymmetric total synthesis to date, which is distinct from previous racemic syntheses reported. We also shed light on the mechanistic aspect of this key reaction to rationalize the superb regioselectivity and stereoselectivity achieved. The third chapter explores the synthetic model studies on ecteinascidin 743, a tetrahydroisoquinolone family natural product with significant antitumor and antimicrobial activities. Several different synthetic routes were attempted, including the N-Methyl and the N-Boc routes, and the results achieved contributed significantly to our final synthetic plan of the target molecule.
35

The Potential of Triclabendazole in Combination with Praziquantel for the Treatment of Schistosoma mansoni Infections

sbong@murdoch.edu.au, Sze How Bong January 2007 (has links)
Previous work has suggested that triclabendazole, a member of the benzimidazole group of compounds, possessed efficacy against Schistosoma mansoni. In view of recent indications in praziquantel treatment failures and loss of sensitivity, it is imperative that new anti-schistosomals are developed as contingent treatment options, while resistance alleles, if any, remain at low frequencies. While recent studies have indicated that triclabendazole monotherapy exert weak anti-schistosomal effects, the combinatorial application of triclabendazole with praziquantel has not been explored. To assess this hypothesis, triclabendazole and its metabolites were initially assessed against the many life-stages of Schistosoma mansoni in vitro. Combinatorial drug and isobologram analyses against adult Schistosoma mansoni was also performed, and subsequently applied against other parasitic models (Giardia duodenalis and Haemonchus contortus) to assess the specificity of such effects. Subsequently, the drug combinations were assessed against Schistosoma mansoni in vivo. To further assess the suitability of combinatorial drug applications, an economic model was developed to project the cost-efficacy of praziquantel-triclabendazole drug combinations in a global focus. It was concluded that triclabendazole and its metabolites possessed good efficacy against immature schistosomula, albeit weak efficacy against adult Schistosoma mansoni. Upon combination with praziquantel, however, a strong synergistic effect against adult worms were observed in vitro. Praziquantel and triclabendazole were also shown to possess unique and independent ovicidal modes of action that can be of clinical significance. More importantly, in vivo drug trials concluded that the combinations exerted additive effects against Schistosoma mansoni harbored in mice. Economic modeling and cost-effectiveness analyses further demonstrated the feasibility of this drug combination, and may represent a new line of treatment against mansonial schistosomiasis
36

Desenvolvimento de hidrogéis de dextrano contendo praziquantel /

Campos, Flávio dos Santos. January 2009 (has links)
Resumo: A esquistossomose é um sério problema de saúde pública nos países tropicais. No Brasil, é causado pelo Schistossoma mansoni. O tratamento é feito com praziquantel, o qual é eficaz contra todas as espécies importantes de esquistossomos, que afetam os seres humanos, apesar de sua alta permeabilidade no Trato Gastrointestinal (TGI). Este fármaco tem solubilidade muito baixa em água, que pode limitar a sua absorção. Devido a essa limitação, a biodisponibilidade do PZQ é muito baixa e seu aumento é um aspecto importante e desafiador no desenvolvimento de formulações. O desenvolvimento de sistemas de liberação de fármacos tem sido muito utilizada no intuito de solucionar a necessidade de melhora de biodisponibilidade de fármacos. Os sistemas de liberação de fármacos permitem uma maior eficácia dos fármacos com a redução das doses e de sua freqüência de administração e redução dos efeitos adversos; aumentando a adesão aos tratamentos por parte dos pacientes. Muitas dessas estratégias estão sendo focadas nos sistemas matriciais poliméricos como, por exemplo, os hidrogéis, os quais são amplamente estudados por prolongarem a liberação dos fármacos. O dextrano é um polissacarídeo, que é altamente hidrofílico, atóxico, seguro, estável, biocompatível e biodegradável. O objetivo deste trabalho é o desenvolvimento de hidrogéis, utilizando dextrano com massas moleculares de 70kDa e 148kDa, e o praziquantel como fármaco-modelo. Os hidrogéis foram preparados e obtidos misturando dextrano e praziquantel em proporções fármaco:polímero de 1:0,5 e 1:1 em sistemas solventes com diferentes valores de constantes dielétricas, os quais foram secas em evaporador rotativo. As propriedades biofarmacêuticas, tais como solubilidade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Schistosomiasis is a serious problem of public health in tropical countries. In Brazil, it is caused by Schistosoma mansoni. The treatment is done with praziquantel which is effective against all important schistosomiasis species, which affect the human being, in spite of its high permeability in Gastrointestinal Tract (TGI). This drug has very poorly water solubility, that could limiting its absorption. Due to this limitation, PZQ's bioavailability is very low and your increase is a challenging and an important aspect for the development of formulations. Development of drug release systems has been very used in order to solve the need of improvement of bioavailability of poorly water soluble drugs. Drug release systems allow for greater effectiveness of drugs by reducing their doses and frequency of administration and reduction of adverse effects; increasing adherence to treatments by patients. Many of these strategies have been focused in polymeric matrix systems such as, the hydrogels, which have been widely studied prolong the release of the drug. Dextran is a polysaccharide that is highly hydrophilic, non toxic, safe, stable, biocompatible and biodegradable. The objective of this work is the development of hydrogels, using dextran with molecular weight of 70kDa and 148kDa, and praziquantel as de drug-like model. Hydrogels were prepared and obtained mixing dextran and praziquantel in proportions drug:polymer of 1:0,5 and 1:1 in solvent systems with different values of dielectric constants, which were dried in rotary evaporator. Biopharmaceutical properties, such as solubility and dissolution rate, were analyzed in the design of hydrogels. Characterization assays were performed swelling test, IR spectroscopy and DSC. The tests of swelling rate showed that the hydrogels swell slowly, but faster than the free polymer... (Complete abstract click electronic access below) / Orientador: Maria Palmira Daflon Gremião / Coorientador: Adélia Emilia de Almeida / Banca: Marco Vinìcius Chaud / Banca: Beatriz Stringuetti Ferreira Cury / Mestre
37

Estudo da resistência do Schistosoma mansoni Sambon, 1907 ao praziquantel

Couto, Flávia Fernanda Bubula January 2014 (has links)
Submitted by Nuzia Santos (nuzia@cpqrr.fiocruz.br) on 2015-04-15T18:38:01Z No. of bitstreams: 1 Tese_DIP_FlaviaFernandaBubulaCouto.pdf: 1019436 bytes, checksum: 5193b8188e8f866ddd717bb135bc3fee (MD5) / Approved for entry into archive by Nuzia Santos (nuzia@cpqrr.fiocruz.br) on 2015-04-15T18:38:09Z (GMT) No. of bitstreams: 1 Tese_DIP_FlaviaFernandaBubulaCouto.pdf: 1019436 bytes, checksum: 5193b8188e8f866ddd717bb135bc3fee (MD5) / Approved for entry into archive by Nuzia Santos (nuzia@cpqrr.fiocruz.br) on 2015-04-15T18:38:18Z (GMT) No. of bitstreams: 1 Tese_DIP_FlaviaFernandaBubulaCouto.pdf: 1019436 bytes, checksum: 5193b8188e8f866ddd717bb135bc3fee (MD5) / Made available in DSpace on 2015-04-15T18:38:18Z (GMT). No. of bitstreams: 1 Tese_DIP_FlaviaFernandaBubulaCouto.pdf: 1019436 bytes, checksum: 5193b8188e8f866ddd717bb135bc3fee (MD5) Previous issue date: 2014 / Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou. Belo Horizonte, MG, Brasil / Atualmente, a droga utilizada no tratamento da esquistossomose é o praziquantel (PZQ). Alguns casos de isolados de S. mansoni resistentes ao PZQ no campo e em laboratório já foram relatados. Estes relatos refletem uma parcela ínfima do problema real, devido às dificuldades para a comprovação dessa resistência em condições de laboratório. Recentemente, nosso grupo conseguiu induzir resistência, em laboratório, a uma cepa de S. mansoni, utilizando sucessivos tratamentos com PZQ em B. glabrata infectadas com o S. mansoni (cepa LE-PZQ). Diante disso, este trabalho teve como objetivo geral avaliar a resistência/ suscetibilidade da cepa LEPZQ ao longo de seu desenvolvimento no hospedeiro vertebrado bem como avaliar a ação do PZQ em cercárias sensíveis e resistentes ao PZQ a fim obter um teste rápido para detecção de resistência e, por fim, estudar o envolvimento das proteínas SMDR2, SmMRP1 e SmMVP na resistência do S. mansoni ao PZQ. Para isso, camundongos infectados com a cepa LE-PZQ ou com a cepa suscetível (LE) foram tratados com PZQ após 2, 6, 16, 23 e 45 dias de infecção. Os resultados mostraram maior recuperação de vermes da cepa resistente tratadas com PZQ após 16 e 23 dias de infecção em comparação com a cepa LE. Outro objetivo do nosso estudo foi avaliar a perda da cauda de cercárias LE e LE-PZQ após 1 e 2 horas de contato com o PZQ em diferentes concentrações. Cercárias LE-PZQ apresentaram uma perda da cauda estatisticamente menor após exposição nas diferentes concentrações de PZQ por 1 ou 2 horas. Artigos sobre resistência à multidrogas (MDR) têm sido importantes para estudo de resistência em diversos organismos. Por isso, investigamos os níveis de RNA de SMDR2 e SMRP1 por qRT-PCR. SMDR2 mostrou níveis maiores em fêmeas quando comparados com machos e vermes em pares na cepa LE. Na cepa LE-PZQ, vermes fêmeas apresentaram níveis maiores quando comparados apenas com vermes machos. Quando comparadas as duas cepas, a resistente apresentou níveis estatisticamente maiores em machos, fêmeas e vermes em pares. SmMRP1 demonstrou expressão significativamente maior em machos e machos e fêmeas nas duas cepas quando comparados com fêmeas. Na comparação entre a cepa sensível e a resistente, a LE-PZQ apresentou maiores níveis de expressão em machos e vermes em pares. Investigamos também os níveis de RNA e proteínas de SmMVP. Foi possível observar que SmMVP está diferencialmente expressa entre machos, fêmeas e vermes em pares quando comparados entre si em cada cepa e quando compara-se cepa sensível e resistente. / Currently, the drug of choice in schistosomiasis treatment is Praziquantel (PZQ). Some cases of S. mansoni resistant strains to PZQ in field and laboratory have been already reported. These cases reports reflect a small parcel of the real problem due to the difficulty to prove this resistance in laboratory conditions. Recently, our group induced resistance in a S. mansoni strain using successive PZQ treatments in B. glabrata infected, under laboratory conditions (LE-PZQ strain). Thus, this work aimed to evaluate the resistance/ susceptibility of the LE-PZQ strain during its development in the vertebrate host as well as to evaluate the PZQ action in susceptible and resistant cercarie in order to obtain a rapid test to detect resistance, and lastly to study the involvement of SMDR, SmMRP1 and SmMVP proteins in the S. mansoni resistance to PZQ. For that, mice were infected with LE-PZQ strain or susceptible strain (LE) and treated with PZQ after 2, 6, 16, 23 and 45 days of infection. The results showed a bigger worm recovery when it was treated after 16 and 23 days of the infection when compared with susceptible strain. We also aimed to evaluate tail loss of LE and LE-PZQ cercarie after exposure to PZQ for 1 or 2 hours in different concentrations. LE-PZQ cercarie showed a statistically smaller tail loss after PZQ exposure in all concentrations for 1 or 2 hours. Works about multidrug resistance (MDR) have been important to studies of resistance in several organisms. Therefore, we investigated levels of RNA for SMDR2, SmMRP1 and SmMVP using RT-PCR. Females showed high levels of expression when compared to males and paired worms in the LE strain. In the LE-PZQ strain, female worms showed high levels of expression only when compared to male worms. When compared both strains, the resistant showed high levels of expression in males, females and paired worms. SmMRP1 showed upregulated in males and paired worms in both strains when compared to females. In the susceptible and resistant strain comparison, LE-PZQ strain showed high levels of expression in male and paired worms. We investigated also RNA and proteins levels for SmMVP. It was possible to observe that SmMVP was found differentially expressed in adult males and females from the susceptible strain.
38

Avaliação do efeito das células-tronco mesenquimais na terapêutica da esquistossomose mansoni experimental

Miranda, Vitor Hugo Simões January 2016 (has links)
Submitted by Nuzia Santos (nuzia@cpqrr.fiocruz.br) on 2016-06-29T14:33:53Z No. of bitstreams: 1 Dissertacao_BCM_VitorMiranda_CPqRR2016.pdf: 25783006 bytes, checksum: 6dba14fa941ca70fa7ddaa50145c6789 (MD5) / Approved for entry into archive by Nuzia Santos (nuzia@cpqrr.fiocruz.br) on 2016-06-29T14:54:44Z (GMT) No. of bitstreams: 1 Dissertacao_BCM_VitorMiranda_CPqRR2016.pdf: 25783006 bytes, checksum: 6dba14fa941ca70fa7ddaa50145c6789 (MD5) / Made available in DSpace on 2016-06-29T14:54:45Z (GMT). No. of bitstreams: 1 Dissertacao_BCM_VitorMiranda_CPqRR2016.pdf: 25783006 bytes, checksum: 6dba14fa941ca70fa7ddaa50145c6789 (MD5) Previous issue date: 2016 / Made available in DSpace on 2016-07-29T17:20:08Z (GMT). No. of bitstreams: 3 Dissertacao_BCM_VitorMiranda_CPqRR2016.pdf.txt: 5144 bytes, checksum: af452bc1e75e1e62019b2414b4f384d9 (MD5) Dissertacao_BCM_VitorMiranda_CPqRR2016.pdf: 25783006 bytes, checksum: 6dba14fa941ca70fa7ddaa50145c6789 (MD5) license.txt: 2991 bytes, checksum: 5a560609d32a3863062d77ff32785d58 (MD5) Previous issue date: 2016 / Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil / A inflamação constitui um mecanismo de defesa local, porém, a falta de controle dessa reação pode causar severos danos aos tecidos. As células-tronco mesenquimais (CTMs) podem se diferenciar em múltiplos tipos celulares in vitro e in vivo, contribuindo, por exemplo, para o reparo de tecidos. Além disso, vários estudos demonstraram que as CTMs interagem com células da imunidade inata e adaptativa, levando a modulação negativa de várias funções efetoras, contribuindo assim, para a redução da inflamação. Entretanto, o efeito dessas células sobre a resposta inflamatória associada com doenças infecciosas e parasitárias, como a esquistossomose, ainda é pouco conhecido. Portanto o objetivo deste trabalho foi avaliar o efeito das CTMs derivadas do tecido adiposo (CTM-TA) na reação granulomatosa decorrente da esquistossomose mansoni experimental. Para isto, as CTM-TA foram caracterizadas fenotípica e funcionalmente, por meio da citometria de fluxo, bem como pela indução da diferenciação osteogênica e adipogênica. Posteriormente, as CTM-TA foram injetadas por via intravenosa em camundongos C57BL/6 infectados por Schistosoma mansoni, tratados ou não com praziquantel (PZQ). Após 15, 30 e 60 dias do tratamento, foram feitas análises histológicas do baço e fígado dos camundongos, bem como do perfil leucocitário e dosagem da enzima alanina aminotransferase (ALT) sérica. Os resultados mostraram que a recuperação do grupo de camundongos infectados e tratados com as CTM-TA associadas ao PZQ foi superior ao do grupo tratado apenas com PZQ. Observamos também melhorias na estrutura histológica do fígado, na arquitetura do espaço portal, redução do infiltrado inflamatório portal, na simplificação da constituição celular dos granulomas, fase do granuloma avançada e fibrosa com cicatrização parcial das lesões, melhoria da atividade inflamatória periportal e do parênquima. Além disso, observamos diminuição significativa dos níveis séricos da enzima ALT, e do tamanho dos granulomas, no tratamento associado. Em conclusão, os resultados mostraram que as CTM-TA controlaram a resposta inflamatória decorrente da infecção pelo S. mansoni , principalmente quando associadas ao praziquantel. / Inflammation is a local defense mechanism, but, the lack of control of this reaction can cause severe tissue damage. Mesenchymal stem cells (MSCs) can differentiate into multiple cell types in vitro and in vivo, contributing, for example, for tissue repair. Furthermore, several studies have demonstrated that MSCs can interact with cells of the innate and adaptive immune system leading to a down-modulation of various effector functions, thus collaborating to reduce inflammation. However, the effect of these cells on the inflammatory response associated with infectious and parasitic diseases, such as schistosomiasis, has not been widely studied. So, the objective of this study was to evaluate the effect of MSCs derived from adipose tissue (MSC-AT) in granulomatous reaction due to the experimental schistosomiasis. Initially, MSC-AT were characterized phenotypically and functionally by flow cytometry, as well as for their osteogenic and adipogenic differentiation. Thereafter, MSC-AT was injected intravenously into C57BL / 6 mice infected with Schistosoma mansoni, treated or not with praziquantel (PZQ). After 15, 30 and 60 days of treatment, histologic analysis of the spleen and liver of the mice were taken and the number of blood leukocytes and dosage of the enzyme alanine aminotransferase (ALT) levels. The results showed that recovery from the group of infected mice and treated with MSC-AT associated PZQ was superior to group treated with PZQ. We also observed improvements in the histological structure of the liver, the architecture of the portal space, reduction of inflammatory infiltrate portal, simplifying cell formation of granulomas, advanced granuloma phase and fibrous partial healing of injuries, improvement of periportal inflammatory activity and parenchymal. In addition, we observed a significant reduction in serum levels of ALT enzyme, and granuloma size, the associated treatment. In conclusion, our results showed that MSC-AT control the inflammation associated with S. mansoni infection, particularly when associated with praziquantel.
39

Desenvolvimento e caracterização de carreadores lipídicos nanoestruturados contendo praziquantel

Santos, Fernanda Kolenyak dos [UNESP] 20 January 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-20Bitstream added on 2014-06-13T20:57:40Z : No. of bitstreams: 1 santos_fk_me_arafcf.pdf: 504042 bytes, checksum: ff6921c63666c7dee3c57494e9ca1b8f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A esquistossomose é uma doença que atinge cerca de 200 milhões de pessoas no mundo todo. A alta incidência desta doença está ligada à falta de condições sanitárias, ao diagnóstico tardio e, principalmente, à falta de tratamento medicamentoso eficiente. O praziquantel é o fármaco de primeira escolha para o tratamento da esquistossomose. No entanto, falhas no tratamento com este fármaco e relatos de isolamento de S. mansoni tolerantes podem comprometer a eficiência do PZQ. Assim, o PZQ representa um fármaco em que pesquisas para melhorar as suas propriedades biofarmacêuticas são necessárias, pois apresenta baixa solubilidade em meio aquoso e biodisponibilidade baixa ou errática. O presente trabalho vê como finalidade desenvolver carreadores lipídicos nanoestruturados (NLC) contendo praziquantel empregando como sistema lipídico o monoestearato de glicerila (GMS) e o ácido oléico (AO) e como sistema tensoativo a associações de monoestearato de polioxietileno sorbitano 60 (TWEEN60), fosfatidilcolina, Poloxamer (Pluronic F-127 PLU). Os NLCs foram preparados através de dois diferentes métodos, de sonicação e alta velocidade de cisalhamento a quente. Os sistemas foram caracterizados através da avaliação dos parâmetros de distribuição de tamanho, potencial zeta, índice de polidispersidade e eficiência de encapsulação. O transporte intestinal do fármaco foi avaliado através do modelo do saco intestinal invertido. Ambos os métodos de obtenção empregados mostraram-se eficazes para o preparo dos NLCs em escala nanometrica, com índice de polidispersidade homogeneo e um... / The Schistosomiasis is a debilitating disease with high misfit in the quality of people life reached about 200 million people worldwide. The high incidence of this disease is linked to poor sanitary conditions, late diagnosis, and especially the lack of effective drug treatment. Praziquantel is the drug of first choice for treatment of schistosomiasis. However, treatment failures with this drug and reports of isolation of S. mansoni tolerance may compromise the efficiency of PZQ. Thus, the PZQ represents an example in which surveys to improve the biopharmaceutical properties are needed, since it has low solubility in aqueous and low or erratic bioavailability. This work aims to develop nanostructured lipid carriers (NLC) containing praziquantel employing as lipid system the glycerin monostearate (GMS) and oleic acid (OA) as a surfactant system and some combination of polyoxyethylene sorbitan monostearate 60 (TWEEN60), phosphatidylcholine and Poloxamer (Pluronic F-127 PLU) as a surfactant system. NLCs were prepared by two different methodologies, the sonication and high shear rates to warm. The systems were characterized by determination of size distribution, zeta potential, polydispersity index and encapsulation efficiency. The intestinal transport of the drug was evaluate by using the model of inverted intestinal sac. Both methods were effective for the preparation of NLCs with an average diameter in the nanometer range, the polydispersity index indicating homogeneity of particle size and a zeta... (Complete abstract click electronic access below)
40

Eficácia de quimioterápicos adicionados à ração para Piaractus mesopotamicus (Osteichthyes:Characidae) no controle de Dolops Carvalhoi (Crustacea:Branchiura) e Anacanthorus Penilabiatus (Monogenea: Dactylogyridae) /

Schalch, Sergio Henrique Canello. January 2006 (has links)
Orientador: Flávio Ruas de Moraes / Banca: Adjair Antonio do Nascimento / Banca: Gilson Pereira de Oliveira / Banca: Laura Satiko Okada Nakaghi / Banca: Oelinton Ferreira Barbosa / Resumo: Avaliou-se no presente trabalho, a eficácia anti-parasitária do praziquantel, levamisol e diflubenzuron administrados via oral, adicionados à ração e administrados a pacus (Piaractus mesopotamicus) infectados por Anacanthorus penilabiatus e Dolops carvalhoi. Foram utilizadas 19 caixas d’água de 300 litros de capacidade, comportando 28 peixes em cada uma. O alimento dos peixes foi feito misturando as drogas na ração. O experimento foi conduzido em quatro colheitas realizadas, um dia antes e três, sete e 15 dias após a aplicação dos medicamentos. A alimentação dos peixes com ração contendo diflubenzuron, levamisol e praziquantel isolado ou associados em diferentes concentrações foi feita durante sete dias. Os resultados da eficácia terapêutica sugerem que simples ou associado com levamisol e praziquantel, o diflubenzuron é eficiente contra o crustáceo D. carvalhoi, demonstrando que a eficácia dos tratamentos nos dias três, sete e 15 foi de 96,2 a 100%. Contra os monogenóides as drogas não apresentaram eficácia satisfatória. Os resultados sugerem o uso do diflubenzuron para o controle de D. cavalhoi em peixes de cativeiro nas condições deste ensaio. / Abstract: This assay evaluated the control efficacy of diflubenzuron, praziquantel and levamisole added to the diet of pacu (Piaractus mesoptamicus) infected with Anacanthorus penilabiatus and Dolops carvalhoi. Nineteen water tanks of 300 liters capacity were utilized with 28 fish in each one. The treatments were made by mixing the active principles in the diet. The experiment was evaluated in four harvests done one day before and three, seven and 15 days after the treatment. The medicated feeding was applied for seven days. The results of efficacy suggest that the diflubenzuron alone or associated with levamisole and praziquantel was efficient against the crustacean D. carvalhoi and the efficacy in the three, seven and 15 days evaluations ranged from 96,2 to 100%. Against the monogenean the drugs did not present efficacy. The results suggest the use of diflubenzuron for the control of D. carvalhoi in captive fishes in the conditions of this trial. / Doutor

Page generated in 0.0812 seconds