Publications by authors named "Saraiva L"

Protease-activated receptor 2 (PAR2) is implicated in the pathogenesis of chronic inflammatory diseases, including periodontitis; it can be activated by gingipain and produced by Porphyromonas gingivalis and by neutrophil protease 3 (P3). PAR2 activation plays a relevant role in inflammatory processes by inducing the release of important inflammatory mediators associated with periodontal breakdown. The effects of periodontal treatment on PAR2 expression and its association with levels of proinflammatory mediators and activating proteases were investigated in chronic periodontitis patients.

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The regulation of protein kinase C (PKC) isoforms by ceramide is still controversial. In this work, the yeast Saccharomyces cerevisiae was used as a model to elucidate the effect of ceramide on the activity of mammalian PKC isoforms. For that, isc1Δ cells, with a deletion in the pathway for ceramide production by hydrolysis of complex sphingolipids, individually expressing mammalian PKCα, δ and ζ were used.

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Background: Biological factors can affect the motor development process of children. However, the magnitude of these effects throughout the developmental process remains fairly unknown.

Aim: To determine the influence of age, sex and selected somatic measures on the motor performance of pre-school children.

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Cell electrospinning and aerodynamically assisted bio-threading are novel bioplatforms for directly forming large quantities of cell-laden scaffolds for creating living sheets and vessels in three-dimensions. The functional biological architectures generated will be useful in both the laboratory and the clinic.

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Multilocus sequence typing (MLST) represents the gold standard genotyping method in studies concerning microbial population structure, being particularly helpful in the detection of clonal relatedness. However, its applicability on large-scale genotyping is limited due to the high cost and time spent on the task. The selection of the most informative nucleotide positions simplifies genomic characterization of bacteria.

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Brain accumulation of soluble amyloid-β oligomers (AβOs) has been implicated in synapse failure and cognitive impairment in Alzheimer's disease (AD). However, whether and how oligomers of different sizes induce synapse dysfunction is a matter of controversy. Here, we report that low-molecular-weight (LMW) and high-molecular-weight (HMW) Aβ oligomers differentially impact synapses and memory.

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Black leaf streak disease (BLSD), also known as black sigatoka, represents the main foliar disease in Brazilian banana plantations. In addition to photosynthetic leaf area losses and yield losses, this disease causes an alteration in the pre- and postharvest behavior of the fruit. The aim of this work was to investigate the starch metabolism of fruits during fruit ripening from plants infected with BLSD by evaluating carbohydrate content (i.

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This study was designed to examine the cultural sensitivity of the PDMS-2 for Portuguese preschool children aged 36-71 months. A total of 540 children (255 males and 285 females) from 15 public preschools of Viana do Castelo, Portugal, were assessed. Age and gender effects in motor performance were examined.

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Desulfovibrio species are Gram-negative anaerobic sulfate-reducing bacteria that colonize the human gut. Recently, Desulfovibrio spp. have been implicated in gastrointestinal diseases and shown to stimulate the epithelial immune response, leading to increased production of inflammatory cytokines by macrophages.

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α-Mangostin (1) and gambogic acid (2) are natural products with potent cytotoxic activity against several human tumor cells. However, their molecular mechanisms of action remain controversial. In this work, using yeast-based assays, it was shown that both xanthones are potential inhibitors of the p53-MDM2 interaction.

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The virtual screening of a library of xanthone derivatives led us to the identification of potential novel MDM2 ligands. The activity of these compounds as inhibitors of p53-MDM2 interaction was investigated using a yeast phenotypic assay, herein developed for the initial screening. Using this approach, in association with a yeast p53 transactivation assay, the pyranoxanthone (3,4-dihydro-12-hydroxy-2,2-dimethyl-2H,6H-pyrano[3,2-b]xanthen-6-one) (1) was identified as a putative small-molecule inhibitor of p53-MDM2 interaction.

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Staphylococcus aureus is a pathogen responsible for severe community- and nosocomially acquired infections. To fight pathogen intrusion, the innate immune system uses a plethora of weapons, with the generation of oxidative and nitrosative stresses among the most efficient. In this work, the S.

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Efficient delivery of small interfering RNA (siRNA) remains the greatest technological barrier to the clinical implementation of RNA interference strategies. We are investigating the relationship between the biophysical properties of siRNA nanocomplexes and their transfection efficiency as an approach to the generation of improved formulations. Peptide-based formulations are of great interest, and so in this study we have compared nanocomplex formulations for siRNA delivery containing linear and branched oligolysine or oligoarginine peptides.

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Sandflies are holometabolous insects that are of great epidemiological importance in the neotropical region as vectors of leishmaniases. Caves are ecotopes that significantly differ from external environments and, among the insects that live or visit their internal area and adjacent environment, sandflies are commonly found. Based on this context, the objective of this work was to examine the period of activity of sandflies in the cave environment in the aphotic zone.

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The transmission of Leishmania involves several species of sand flies that are closely associated with various parasites and reservoirs, with differing transmission cycles in Brazil. A study on the phlebotomine species composition has been conducted in the municipality of Divinópolis, Minas Gerais, Brazil, an endemic area for cutaneous leishmaniasis (CL), which has intense occurrence of visceral leishmaniasis (VL) cases. In order to study the sand flies populations and their seasonality, CDC light traps (HP model) were distributed in 15 houses which presented at least one case of CL or VL and in five urban parks (green areas).

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Nyssomyia intermedia and Nyssomyia neivai constitute a species complex associated with Leishmania transmission. The aim of this study was to analyse the ecological profiles of the Ny. intermedia and Ny.

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Sulfate-reducing microorganisms are a diverse group of bacteria and archaea that occupy important environmental niches and have potential for significant biotechnological impact. Desulfovibrio, the most studied genus among the sulfate-reducing microorganisms, contains proteins with a wide variety of tetrapyrrole-derived cofactors, including some unique derivatives such as uroporphyrin I and coproporphyrin III. Herein, we review tetrapyrrole metabolism in Desulfovibrio spp.

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The discovery of a novel canine norovirus was recently reported. The VP1 capsid protein of this canine norovirus was expressed in Saccharomyces cerevisiae and purified with a yield of 1.6-1.

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As a model organism Saccharomyces cerevisiae has greatly contributed to our understanding of many fundamental aspects of cellular biology in higher eukaryotes. More recently, engineered yeast models developed to study endogenous or heterologous proteins that lay at the root of a given disease have become powerful tools for unraveling the molecular basis of complex human diseases like neurodegeneration. Additionally, with the possibility of performing target-directed large-scale screenings, yeast models have emerged as promising first-line approaches in the discovery process of novel therapeutic opportunities against these pathologies.

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An increasing number of researchers are using the Saccharomyces cerevisiae chronological aging model to gain insight into the post-mitotic cellular aging. Recently, an alternative approach to the traditional cellular viability assay by colony-forming unit (CFU) counts, based on the propidium iodide (PI) staining combined with flow cytometry (PI-FCM), was proposed for the assessment of yeast chronological aging. Since the chronological aging assessment shows variations particularly concerning the aging media, in this work, the influence of the most common aging media (exhausted media or water) on the assessment of chronological aging by PI staining was studied.

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Carbon monoxide-releasing molecules (CO-RMs) are, in general, transition metal carbonyl complexes that liberate controlled amounts of CO. In animal models, CO-RMs have been shown to reduce myocardial ischaemia, inflammation and vascular dysfunction, and to provide a protective effect in organ transplantation. Moreover, CO-RMs are bactericides that kill both Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa.

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Yeast revealed to be a versatile organism for studying endocytosis. Here, inhibition of endocytosis by H(2)O(2) and its correlation with apoptotic cell death were ascertained in Saccharomyces cerevisiae. We found that H(2)O(2) causes alterations in vacuolar morphology and a concentration-dependent inhibition of endocytosis.

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Intracellular free iron, is under aerobic conditions and via the Fenton reaction a catalyst for the formation of harmful reactive oxygen species. In this article, we analyzed the relation between intracellular iron storage and oxidative stress response in the sulfate reducing bacterium Desulfovibrio vulgaris Hildenborough, an anaerobe that is often found in oxygenated niches. To this end, we investigated the role of the iron storage protein bacterioferritin using transcriptomic and physiological approaches.

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