96 research outputs found

    Schistosoma mansoni Stomatin Like Protein-2 Is Located in the Tegument and Induces Partial Protection against Challenge Infection

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    Schistosomiasis is a parasitic disease causing serious chronic morbidity in tropical countries. Together with the publication of the transcriptome database, a series of new vaccine candidates were proposed based on their functional classification. However, the prediction of vaccine candidates from sequence information or even by proteomics or microarrays data is somewhat speculative and there remains the considerable task of functional analysis of each new gene/protein. In this study, we present the characterization of one of these molecules, a stomatin like protein 2 (SmStoLP-2). Sequence analysis predicts signals that could contribute to protein membrane association and mitochondrial targeting, which was confirmed by differential extractions of schistosome tegument membranes and mitochondria. Additionally, confocal microscope analysis showed SmStoLP-2 present in the tegument of 7-day-old schistosomula and adult worms. Studies in patients living in endemic areas for schistosomiasis revealed high levels of IgG1, IgG2, IgG3 and IgA anti-SmStoLP-2 antibodies in individuals resistant to reinfection. Recombinant SmStoLP-2 protein, when used as vaccine, induced significant levels of protection in mice. This reduction in worm burden was associated with a typical Th1-type immune response. These results indicate that SmStoLP-2 could be useful in association with other antigens for the composition of a vaccine against schistosomiasis

    DNA Barcoding Bromeliaceae: Achievements and Pitfalls

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    <div><h3>Background</h3><p>DNA barcoding has been successfully established in animals as a tool for organismal identification and taxonomic clarification. Slower nucleotide substitution rates in plant genomes have made the selection of a DNA barcode for land plants a much more difficult task. The Plant Working Group of the Consortium for the Barcode of Life (CBOL) recommended the two-marker combination <em>rbcL</em>/<em>matK</em> as a pragmatic solution to a complex trade-off between universality, sequence quality, discrimination, and cost.</p> <h3>Methodology/Principal Findings</h3><p>It is expected that a system based on any one, or a small number of plastid genes will fail within certain taxonomic groups with low amounts of plastid variation, while performing well in others. We tested the effectiveness of the proposed CBOL Plant Working Group barcoding <em>markers</em> for land plants in identifying 46 bromeliad species, a group rich in endemic species from the endangered Brazilian Atlantic Rainforest. Although we obtained high quality sequences with the suggested primers, species discrimination in our data set was only 43.48%. Addition of a third marker, <em>trnH–psbA</em>, did not show significant improvement. This species identification failure in Bromeliaceaecould also be seen in the analysis of the GenBank's <em>matK</em> data set. Bromeliaceae's sequence divergence was almost three times lower than the observed for Asteraceae and Orchidaceae. This low variation rate also resulted in poorly resolved tree topologies. Among the three Bromeliaceae subfamilies sampled, Tillandsioideae was the only one recovered as a monophyletic group with high bootstrap value (98.6%). Species paraphyly was a common feature in our sampling.</p> <h3>Conclusions/Significance</h3><p>Our results show that although DNA barcoding is an important tool for biodiversity assessment, it tends to fail in taxonomy complicated and recently diverged plant groups, such as Bromeliaceae. Additional research might be needed to develop markers capable to discriminate species in these complex botanical groups.</p> </div

    Projeto TURARQ - Turismo Arqueológico para Territórios de Baixa Densidade do Médio Tejo

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    Apresentação do projeto TurArq, que tem como objetivo principal promover o turismo científico e cultural em territórios de baixa densidade do Médio Tejo português (municípios de Abrantes, Constância, Mação, Tomar e Vila Nova da Barquinha), gerando riqueza e novos empregos, apostando no usufruto presencial do património arqueológico e nos meios de divulgação digital. O projeto pretende contribuir para uma gestão patrimonial integrada na região, a fixação de capital humano, a mobilização de recursos dedicados à sua capacitação e a valorização do património existente. Visa ainda promover o desenvolvimento comunitário, a coesão do território e a sua preservação, numa lógica de sustentabilidade.Os autores agradecem ao projeto “Contratação de Recursos Humanos Altamente Qualificados - Territórios do interior - Entidades Não Empresariais do Sistema I&I” (Centro-04-3559-Fse-000158), financiado pelo Fundo Social Europeu e pelo Instituto Politécnico de Tomar. Trabalho financiado por fundos nacionais através da Fundação para a Ciência e Tecnologia (Fct), no âmbito dos projetos Uid/00073//2020 (Cgeo), Uid/05488/2020 (Techn&Art) e Uid/05567/2020 (Ci2)info:eu-repo/semantics/publishedVersio

    Leishmania braziliensis exosomes activate human macrophages to produce proinflammatory mediators

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    Exosomes, organelles measuring 30-200nm, are secreted by various cell types. Leishmania exosomes consist of many proteins, including heat shock proteins, annexins, Glycoprotein 63, proteins exerting signaling activity and those containing mRNA and miRNA. Studies have demonstrated that Leishmania donovani exosomes downregulate IFN-γ and inhibit the expression of microbicidal molecules, such as TNF and nitric oxide, thus creating a microenvironment favoring parasite proliferation. Despite lacking immunological memory, data in the literature suggest that, following initial stimulation, mononuclear phagocytes may become “trained” to respond more effectively to subsequent stimuli. Here we characterized the effects of macrophage sensitization using L. braziliensis exosomes prior to infection by the same pathogen. Human macrophages were stimulated with L. braziliensis exosomes and then infected with L. braziliensis. Higher levels of IL-1β and IL-6 were detected in cultures sensitized prior to infection compared to unstimulated infected cells. Moreover, stimulation with L. braziliensis exosomes induced macrophage production of IL-1β, IL-6, IL-10 and TNF. Inhibition of exosome secretion by L. braziliensis prior to macrophage infection reduced cytokine production and produced lower infection rates than untreated infected cells. Exosome stimulation also induced the consumption/regulation of NLRP3 inflammasome components in macrophages, while the blockade of NLRP3 resulted in lower levels of IL-6 and IL-1β. Our results suggest that L. braziliensis exosomes stimulate macrophages, leading to an exacerbated inflammatory state that may be NLRP3-dependent

    Efeito do extrato aquoso de Sida cordifolia na regeneração hepática após hepatectomia parcial

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    Introdução: O uso de plantas medicinais para o tratamento de patologias humanas tem aumentado em todo mundo. Muitas delas são usadas por administração oral, e após a absorção podem afetar muitos órgãos. Objetivo: Esse estudo, tem como objetivo verificar o efeito do extrato aquoso de Sida cordifolia, popularmente conhecida no Brasil como “malva-branca”, na regeneração hepática. Métodos: Vinte ratos foram divididos em 4 grupos: controle, Sida 100, Sida 200 e Sida 400. Os animais foram submetidos a administração oral de água destilada, 100, 200 e 400 mg/kg de extrato aquoso de Sida cordifolia, respectivamente. Imediatamente após, foi realizada hepatectomia parcial 67%. Vinte quatro horas após, os fígados foram removidos. A regeneração hepática foi avaliada por imunohistoquímica (PCNA), usando o anticorpo monoclonal PC-10. Resultados: Os grupos Sida100 e Sida200 mostraram índices de regeneração hepática maiores que o grupo controle (p<0.001 e p<0.05, respectivamente). Conclusão: O extrato aquoso de Sida cordifolia estimula a regeneração hepática após hepatectomia parcial a 67% em ratos. _________________________________________________________________________________________ ABSTRACT: Purpose: The use of medicinal plants for the treatment of human diseases has increased worldwide. Many of them are used by oral administration and, after absorption, may affect many organs. Therefore, this study aimed at assessing the effects of the aqueous extract of Sida cordifolia leaves, popularly known in Brazil as “malva-branca”, on liver regeneration. Methods: Twenty rats were divided into four groups: control, Sida100, Sida200 and Sida400 groups. All animals were submitted to oral administration of distilled water, 100, 200 and 400 mg/kg of the aqueous extract of Sida cordifolia, respectively. Immediately after this, they underwent 67% partial hepatectomy. Twenty four hours later, their livers were removed. Hepatic regeneration was assessed by immunohistochemical staining for proliferating cell nuclear antigen (PCNA) using the PC-10 monoclonal antibody. Results: Sida100 and Sida200 groups disclosed higher liver regeneration indices than control group (p<0.001 and p<0.05, respectively). Conclusion: The aqueous extract of Sida cordifolia stimulates liver regeneration after 67% partial hepatectomy in rats

    Microbiological quality in the flour and starch cassava processing in traditional and model unit

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    O objetivo deste trabalho foi avaliar a qualidade microbiológica de farinha e fécula durante as diferentes etapas do processamento de mandioca, em unidades tradicionais e em uma unidade modelo. Foram determinados índices de coliformes totais e termotolerantes, Bacillus cereus, Salmonela spp., bactérias e fungos nas farinhas e féculas. Não foram observadas presenças de B. cereus e Salmonella spp. na farinha e fécula de mandioca produzidas nas unidades estudadas. A incidência microbiana diminui com o avanço da etapa do processamento para obtenção de farinha e foi menor na unidade modelo. Após o processo de torra, a carga microbiana estava de acordo com os valores preconizados pela legislação brasileira, concluindo-se que essa etapa pode ser considerada como crítica na obtenção de farinha. Na obtenção de fécula, a carga microbiana nas unidades tradicionais são maiores que na modelo, e o aumento do número de extrações promove o aumento da incidência de microrganismos, sendo recomendadas apenas quatro extrações. ______________________________________________________________________________________ ABSTRACT: The objective of this research was to evaluate microbiological contamination in the flour and starch during cassava processing in traditional and model units. The total and fecal coliforms indexes, Bacillus cereus, Salmonella, bacteria, yeast and fungi were determined. Bacillus cereus and Salmonella were not detected in any sample. The incidence of microorganisms decreased along the processing to obtain cassava flour, and is lower in model unit. After the roasting process, the microbial load was below the values established by the Brazilian legislation, and can be regarded as a critical step in obtaining cassava flour. Concerning starch production, the microbial load in the traditional units was higher than in the model units, and the increase of the extraction steps has promoted the growth of microorganisms. It’s recommended the used of only 4 extractions
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