81 research outputs found

    Characterization of an antagonistic peptide produced by a Bacteroides Fragilis isolate obtained from a patient with intra-abdominal infection / Caracterização de um peptido antagonístico produzido por Bacteroides Fragilis isolado obtido em um paciente com infecção intra-abdominal

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    The indigenous microbiota of humans is extremely rich and diverse, with special emphasis on the intestinal microbiota. As a constituent of this microbiota, it is mentioned the genus Bacteroides, whose members are Gram negative rods, obligate anaerobes, amphibionts, associated to the etiopathogenesis of important infectious diseases, such as intra-abdominal infections. Bacteroides strains have the ability to synthesize antagonistic substances that play an ecological role, especially in densely colonized habitats, giving a competitive advantage to the producing samples. The objective of this study was to evaluate the synthesis capacity of antagonistic substances by 40 samples of Bacteroides and Parabacteroides isolated from patients with intra-abdominal infections. The expression of antagonism was evaluated by the overlay diffusion method, using, as well as the test samples, 36 reference samples of Gram negative and Gram-positive bacteria. Subsequently, a production strain (Bacteroides fragilis) was used for extraction, purification and partial characterization of the detected antagonistic substance. As indicator strains, Bacteroides ovatus and Bacteroides caccae were used. The production strain was submitted to protein extraction, and the activity of the precipitated intracellular extract was detected with (NH4) 2SO4 in concentrations of 30% (C30) and 50% (C50). C30 and C50 were inactivated by proteases and high temperatures and remained active after exposure to organic solvents and a wide pH range. Both fractions presented antagonistic activity of bacteriostatic nature. The C50 extract was subjected to ion exchange chromatography, and 50 fractions were recovered. Among them, fractions 1 to 4, referring to a single peak, that were not able to bind to the column, presented antagonistic activity. Fractions from the ion exchange chromatography were applied in gel filtration chromatography. Among them, fractions 2 and 3 were able to inhibit the developing sample. These fractions were submitted to reverse phase chromatography, and 50 fractions were collected. One of them, fraction 2C, remained active against the revealing sample. Mass spectrometry, from fraction 2C obtained from reverse phase chromatography, presented ions of approximately 1300.00 Da, which generated a more intense signal. The search performed by similarity between the sequenced peptides and proteins described in the BLASTP database, from fragmentation obtained in reverse phase chromatography, resulted in 100% identity between two peptides. One of the sequenced peptides showed 100% identity to a type VII secretion protein. The search performed by similarity between the sequenced peptides and proteins described in the ANTIMICROBIAL PEPTIDE DATABASE database, from fragmentation obtained with trypsin digestion, resulted in 42% identity with a Streptomyces microcine. Together, the results indicate the production of antagonistic substances by the B. fragilis sample under study. It is plausible to assume that they play a relevant role in interbacterial relationships, as a virulence factor, in a complex environment such as intra-abdominal infection

    A new species of jupati, genus Metachirus Burmeister 1854 (Didelphimorphia, Didelphidae) for the Brazilian Amazon

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    The brown or pouchless four-eyed opossums or jupatis represent the genus Metachirus with a wide geographical range in the Neotropics. Recent studies show distinct monophyletic clades with high genetic divergence and recognized two species, Metachirus nudicaudatus and Metachirus myosuros. Nevertheless, there is a need for systematic revision with multiple sources of evidence on the taxonomy of Metachirus, which has never been fully revised. Here we describe a new species of Metachirus for the Brazilian Amazon from the Xingu/Tocantins interfluve using the unification of concepts and evolutionary significant units, morphological, genetic, and geographic data. Our analysis reveals a new species within Metachirus as a differentiated Amazonian clade from the Serra dos Carajás region and the Caxiuanã National Forest, both in the Xingu endemism centre. This new species can be distinguished from the type species, M. nudicaudatus and from M. myosuros through discrete external morphological characters, including cranium and dentition, and molecular data with an average degree of divergence, but ancient divergence time for the mitochondrial cytochrome b gene. The Amazon River delimits the distribution of the new species, which also occurs in areas under strong anthropogenic pressure, reinforcing the importance to guide conservation strategies for the region. didelphid; Serra dos Carajás; taxonomy; Xingu/ Tocantins interfluve.acceptedVersio

    Qualitative characteristics of the Longissimus thoracic lumborum muscle of Nellore cattle during different maturation periods

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    The effect of maturation on the physical (pH, color, weight loss on cooking, and shear force) and biological (microbiology, concerning mesophiles and psychrotrophiles, and sarcomere length) characteristics of the Longissimus thoracic lumborum muscle of adult Nellore cattle was assessed over four maturation periods (0, 7, 14, and 21 days) and two cut thicknesses (2.5 and 7.5 cm). Sixty-four Longissimus thoracic lumborum muscles from castrated Nellore males were purchased from Frigorífico Nutrial, Sergipe, Brazil. The study was performed using a completely randomized design, corresponding to a 2 x 4 factorial with eight replicates. The microbiological analysis revealed the sanitary conditions in which the samples were handled and stored, yielding counts of psychrotrophiles (2.18 x 105 CFU g-1) and mesophiles (2.4 x 105 CFU g-1) well below the critical deterioration level (106 CFU g-1). The pH (5.57) and the loss on cooking (24.13%) were not influenced by the evaluated variables (P > 0.05). The other evaluated parameters significantly varied as a function of the maturation period and the cut thickness (both P 0.05). Regarding the b* intensity, the 2.5-cm cut yielded a darker staining at time zero, which decreased with the maturation period. However, the 7.5-cm cut differed between the non-matured and the matured samples. Regarding the red and yellow color of the meat fat (a* and b*, respectively), a* displayed lighter intensity at 7 days of maturation or the 2.5-cm cut (P 0.05). The shear force of the meat decreased to 4.49 kgf at 21 days of maturation. The sarcomere length varied for the 2.5-cm cut (P 0.05). Longissimus thoracic lumborum muscle of adult Nellore cattle should be matured as a larger, vacuum-packed cut for a minimum of 14 days to produce meat with improved quality

    SELNET clinical practice guidelines for bone sarcoma

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    Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context

    AVASUS’ Contributions to Promoting Lifelong Learning in Health: Toward Achieving the SDGs and Strengthening Global Health Security

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    The Virtual Learning Environment of the Brazilian Health System (AVASUS) was developed by the Laboratory for Technological Innovation in Health (LAIS) and the Secretariat of Distance Education (SEDIS) at the Federal University of Rio Grande do Norte (UFRN) in partnership with Brazil’s Ministry of Health (MoH). AVASUS provides open educational resources in the health field and has emerged as the third largest platform for massive health education globally, with more than one million students. Among the various learning pathways AVASUS offers, some specifically focus on meeting the educational needs to address public health emergencies and overlooked health contexts. The main argument in this study is that technology-mediated lifelong learning in health is an effective strategy for achieving the Sustainable Development Goals (SDGs) of the 2030 Agenda. This chapter analyzes the pathways related to COVID-19, syphilis, and prison health, focusing on the contributions towards achieving SDGs 3, 4, 5, 10, 11, 16, and 17 and fulfilling the Global Health Security Agenda. Our analysis revealed two key findings. Lifelong learning in health (i) prompts decision-making on public health policies and (ii) contributes towards implementing the SDGs. Ultimately, AVASUS should be recognized as a tool to improve health services and support policy-making

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
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