1,944 research outputs found

    GABA in the central amygdaloid nucleus modulates the electrolyte excretion and hormonal responses to blood volume expansion in rats

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    We investigated the involvement of GABAergic mechanisms of the central amygdaloid nucleus (CeA) in unanesthetized rats subjected to acute isotonic or hypertonic blood volume expansion (BVE). Male Wistar rats bearing cannulas unilaterally implanted in the CeA were treated with vehicle, muscimol (0.2 nmol/0.2 µL) or bicuculline (1.6 nmol/0.2 µL) in the CeA, followed by isotonic or hypertonic BVE (0.15 or 0.3 M NaCl, 2 mL/100 g body weight over 1 min). The vehicle-treated group showed an increase in sodium excretion, urinary volume, plasma oxytocin (OT), and atrial natriuretic peptide (ANP) levels compared to control rats. Muscimol reduced the effects of BVE on sodium excretion (isotonic: 2.4 ± 0.3 vs vehicle: 4.8 ± 0.2 and hypertonic: 4.0 ± 0.7 vs vehicle: 8.7 ± 0.6 µEq·100 g-1·40 min-1); urinary volume after hypertonic BVE (83.8 ± 10 vs vehicle: 255.6 ± 16.5 µL·100 g-1·40 min-1); plasma OT levels (isotonic: 15.3 ± 0.6 vs vehicle: 19.3 ± 1 and hypertonic: 26.5 ± 2.6 vs vehicle: 48 ± 3 pg/mL), and ANP levels (isotonic: 97 ± 12.8 vs vehicle: 258.3 ± 28.1 and hypertonic: 160 ± 14.6 vs vehicle: 318 ± 16.3 pg/mL). Bicuculline reduced the effects of isotonic or hypertonic BVE on urinary volume and ANP levels compared to vehicle-treated rats. However, bicuculline enhanced the effects of hypertonic BVE on plasma OT levels. These data suggest that CeA GABAergic mechanisms are involved in the control of ANP and OT secretion, as well as in sodium and water excretion in response to isotonic or hypertonic blood volume expansion.FAPESPCNP

    The impact of the COVID-19 pandemic on cancer screening

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    Letter to the editorThis study was funded by the Foundation for Science and Technology – FCT (Portuguese Ministry of Science, Technology and Higher Education) in collaboration with the Agency for Clinical Research and Biomedical Innovation (AICIB), under the scope of the project ‘Impacto da pandemia COVID-19 nos cuidados prestados a doentes oncológicos’ (Research 4 COVID 174_596850546), and national funding from FCT, under the Unidade de Investigação em Epidemiologia – Instituto de Saúde Pública da Universidade do Porto (EPIUnit; info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB/04750/2020/PT). SM was also funded under the scope of the project ‘NEON-PC - Neuro-oncological complications of prostate cancer: longitudinal study of cognitive decline’ (POCI-01-0145-FEDER-032358; ref. PTDC/SAU-EPI/32358/2017), which is funded by FEDER through the Operational Programme Competitiveness and Internationalization, and national funding from FCT. The funding sources had no involvement in the conduct of the research and/or preparation of the article

    Chromobacterium violaceum as a potential biosurfactant‐producing microorganism

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    Chromobacterium violaceum is a Gram‐negative bacterium found in the soil and water in tropical and sub‐tropical environments. Its complete genome sequence revealed wide varying alternative pathways for energy generation, complex and extensive systems for stress adaptation, motility and widespread utilization of quorum sensing for control of its inducible systems. Biosurfactants are amphiphilic compounds produced by microorganisms, both intra and extracellularly, that reduce surface and interfacial tensions. In this work, C. violaceum UCP 1552 isolated from the contaminated area of Pernambuco, was used. Biosurfactant production was carried out in 500mL Erlenmeyer flasks containing 250mL of LB medium [tryptone – 10g/L, yeast extract – 5g/L, sodium chloride – 5g/L] plus 5g/L glucose and 1.6g/L soy oil, at 150 rpm and 30°C. Samples were collected at different fermentation times (from 0 to 188h) to evaluate cellular growth, glucose consumption and biosurfactant production (by reduction of surface tension and emulsification index determination). Biomass growth was observed during the first 96h and afterwards the cells entered the stationary phase. Moreover, glucose was consumed in the first 30h. Surface tension of the fermentation broth free of C. violaceum cells recovered after 188h was found to be 32 mN/m. The highest emulsification index was observed for 12h experiment, being 56 and 59% for sunflower oil and nhexadecane, respectively. Results gathered in this study reveal the C. violaceum potential as a biosurfactant‐producer opening novel perspectives for its application in the environmental area.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Representação de ciclos harmônicos de séries temporais de dados EVI/MODIS para análise do cultivo da cana-de-açúcar.

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    O objetivo deste trabalho foi analisar o cultivo da cana-de-açúcar no Estado de São Paulo, utilizando a análise harmônica aplicada em séries temporais de dados EVI/MODIS, do período de outubro de 2001 a setembro de 2011, por meio da representação dos termos harmônicos.SBSR 2013

    Analysis of the vegetation phenology from the Alto Paraguai basin throught the representation of harmonic cycles of EVI/MODIS time-series.

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    The Alto Paraguai Basin (BAP) is of strategic importance for Brazil, due to its ecological diversity of landscape, especially because it includes the Pantanal floodplain. The harmonic analysis can be used in remote sensing time-series data to study the cyclic behavior of vegetation indices. The visual representation of harmonic terms can hel image interpretation through the combination of colors in the HLS (Hue, Lightness, Saturation) space which provides a soft visual transition effect between the cycles. The objective of this study was to analyze the vegetation phenology of the BAP using the harmonic analysis applied to an EVI (Enhanced Vegetation Index) time-series data from MODIS (Moderate Resolution Imaging Spectroradiometer) during 10 hydrologic years from October 2001 to September 2011, considering the HLS representation of the harmonic terms. The results show that the vegetation phenology of BAP presents spatial patterns coherent with the vegetation development and consistent with the variability of the seasonal inundations in Pantanal, which determines the hydrologic conditions of the region, directly affecting the moment of maximum EVI. The HLs representation of harmonic terms indicates that it is an effective tool for the visual interpretation of vegetation cycles

    Rhipicephalus bursa Sialotranscriptomic Response to Blood Feeding and Babesia ovis Infection: Identification of Candidate Protective Antigens

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    Ticks are among the most prevalent blood-feeding arthropods, and they act as vectors and reservoirs for numerous pathogens. Sialotranscriptomic characterizations of tick responses to blood feeding and pathogen infections can offer new insights into the molecular interplay occurring at the tick-host-pathogen interface. In the present study, we aimed to identify and characterize Rhipicephalus bursa salivary gland (SG) genes that were differentially expressed in response to blood feeding and Babesia ovis infection. Our experimental approach consisted of RNA sequencing of SG from three different tick samples, fed-infected, fed-uninfected, and unfed-uninfected, for characterization and inter-comparison. Overall, 7,272 expressed sequence tags (ESTs) were constructed from unfed-uninfected, 13,819 ESTs from fed-uninfected, and 15,292 ESTs from fed-infected ticks. Two catalogs of transcripts that were differentially expressed in response to blood feeding and B. ovis infection were produced. Four genes coding for a putative vitellogenin-3, lachesin, a glycine rich protein, and a secreted cement protein were selected for RNA interference functional studies. A reduction of 92, 65, and 51% was observed in vitellogenin-3, secreted cement, and lachesin mRNA levels in SG, respectively. The vitellogenin-3 knockdown led to increased tick mortality, with 77% of ticks dying post-infestation. The reduction of the secreted cement protein-mRNA levels resulted in 46% of ticks being incapable of correctly attaching to the host and significantly lower female weights post-feeding in comparison to the control group. The lachesin knockdown resulted in a 70% reduction of the levels associated with B. ovis infection in R. bursa SG and 70% mortality. These results improved our understanding of the role of tick SG genes in Babesia infection/proliferation and tick feeding. Moreover, lachesin, vitellogenin-3, and secreted cement proteins were validated as candidate protective antigens for the development of novel tick and tick-borne disease control measures.FCT for funds to GHTM UID/Multi/04413/2013.info:eu-repo/semantics/publishedVersio
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