119 research outputs found

    Proteomic Analysis Reveals That Iron Availability Alters the Metabolic Status of the Pathogenic Fungus Paracoccidioides brasiliensis

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    Paracoccidioides brasiliensis is a thermodimorphic fungus and the causative agent of paracoccidioidomycosis (PCM). The ability of P. brasiliensis to uptake nutrients is fundamental for growth, but a reduction in the availability of iron and other nutrients is a host defense mechanism many pathogenic fungi must overcome. Thus, fungal mechanisms that scavenge iron from host may contribute to P. brasiliensis virulence. In order to better understand how P. brasiliensis adapts to iron starvation in the host we compared the two-dimensional (2D) gel protein profile of yeast cells during iron starvation to that of iron rich condition. Protein spots were selected for comparative analysis based on the protein staining intensity as determined by image analysis. A total of 1752 protein spots were selected for comparison, and a total of 274 out of the 1752 protein spots were determined to have changed significantly in abundance due to iron depletion. Ninety six of the 274 proteins were grouped into the following functional categories; energy, metabolism, cell rescue, virulence, cell cycle, protein synthesis, protein fate, transcription, cellular communication, and cell fate. A correlation between protein and transcript levels was also discovered using quantitative RT-PCR analysis from RNA obtained from P. brasiliensis under iron restricting conditions and from yeast cells isolated from infected mouse spleens. In addition, western blot analysis and enzyme activity assays validated the differential regulation of proteins identified by 2-D gel analysis. We observed an increase in glycolytic pathway protein regulation while tricarboxylic acid cycle, glyoxylate and methylcitrate cycles, and electron transport chain proteins decreased in abundance under iron limiting conditions. These data suggest a remodeling of P. brasiliensis metabolism by prioritizing iron independent pathways

    Evidence of contamination by oil and oil products in the Santos-Sao Vicente estuary, Sao Paulo, Brazil

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    Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/Sao Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatao city and of another of low anthropogenic influence (Cananeia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/Sao Vicente estuary.CAPES (Brazilian Agency for Science and Technology); Oceanographic Institute of Sao Paulo University; Laboratory of Ecotoxicology and Environmental Chemistry of the University of Algarve; CAPES-PDEE [BEX 2176/07-6]info:eu-repo/semantics/publishedVersio

    Profile of paediatric rheumatology specialists and services in the state of São Paulo

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    INTRODUCTION: Paediatric rheumatology (PR) is an emerging specialty, practised by a limited number of specialists. Currently, there is neither a record of the profile of rheumatology patients being treated in Brazil nor data on the training of qualified rheumatology professionals in the country. OBJECTIVE: To investigate the profile of PR specialists and services, as well as the characteristics of paediatric patients with rheumatic diseases, for estimating the current state of rheumatology in the state of São Paulo. PATIENTS AND METHODS: In 2010, the scientific department of PR of the Paediatric Society of São Paulo administered a questionnaire that was answered by 24/31 accredited specialists in PR practising in state of São Paulo and by 8/21 institutions that provide PR care. RESULTS: Most (91%) of the surveyed professionals practise in public institutions. Private clinics (28.6%) and public institutions (37.5%) reported not having access to nailfold capillaroscopy, and 50% of the private clinics reported not having access to acupuncture. The average duration of professional practise in PR was 9.4 years, and 67% of the physicians had attended postgraduate programmes. Seven (87.5%) public institutions perform teaching activities, in which new paediatric rheumatologists are trained, and five (62.5%) offer postgraduate programmes. Two-thirds of the surveyed specialists use immunosuppressants and biological agents classified as restricted use by the Health Secretariat. The disease most frequently reported was juvenile idiopathic arthritis (29.1-34.5%), followed by juvenile systemic lupus erythematosus (JSLE) (11.6-12.3%) and rheumatic fever (9.1-15.9%). The incidence of vasculitis (including Henoch-Schönlein purpura, Wegener's granulomatosis, and Takayasu's arteritis) and autoinflammatory syndromes was higher in public institutions compared to other institutions (P = 0.03, P = 0.04, P = 0.002, and P < 0.0001, respectively). Patients with JSLE had the highest mortality rate (68% of deaths), mainly due to infection. CONCLUSION: The field of PR in the state of São Paulo has a significant number of specialists with postgraduate degrees who mostly practise at teaching institutions with infrastructures appropriate for the care of high-complexity patients.INTRODUÇÃO: A reumatologia pediátrica (RP) é uma especialidade emergente, com número restrito de especialistas, e ainda não conta com uma casuística brasileira sobre o perfil dos pacientes atendidos e as informações sobre a formação de profissionais capacitados. OBJETIVO: Estudar o perfil dos especialistas e dos serviços em RP e as características dos pacientes com doenças reumáticas nessa faixa etária a fim de estimar a situação atual no estado de São Paulo (ESP). PACIENTES E MÉTODOS: No ano de 2010 o departamento científico de RP da Sociedade de Pediatria de São Paulo encaminhou um questionário respondido por 24/31 especialistas com título de especialização em RP que atuam no ESP e por 8/12 instituições com atendimento nesta especialidade. RESULTADOS: A maioria (91%) dos profissionais exerce suas atividades em instituições públicas. Clínicas privadas (28,6%) e instituições (37,5%) relataram não ter acesso ao exame de capilaroscopia e 50% das clínicas privadas não tem acesso à acupuntura. A média de tempo de prática profissional na especialidade foi de 9,4 anos, sendo 67% deles pós-graduados. Sete (87,5%) instituições públicas atuam na área de ensino, formando novos reumatologistas pediátricos. Cinco (62,5%) delas têm pós-graduação. Dois terços dos especialistas utilizam imunossupressores e agentes biológicos de uso restrito pela Secretaria da Saúde. A doença mais atendida foi artrite idiopática juvenil (29,1%-34,5%), seguida de lúpus eritematoso sistêmico juvenil (LESJ) (11,6%-12,3%) e febre reumática (9,1%-15,9%). Vasculites (púrpura de Henoch Schönlein, Wegener, Takayasu) e síndromes autoinflamatórias foram mais incidentes nas instituições públicas (P = 0,03; P = 0,04; P = 0,002 e P < 0,0001, respectivamente). O LESJ foi a doença com maior mortalidade (68% dos óbitos), principalmente por infecção. CONCLUSÃO: A RP no ESP conta com um número expressivo de especialistas pós-graduados, que atuam especialmente em instituições de ensino, com infraestrutura adequada ao atendimento de pacientes de alta complexidade.34635

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (&gt;66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Pervasive gaps in Amazonian ecological research

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