2,656 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 role of estradiol in adrenal insufficiency and its interaction with corticosterone on hydromineral balance

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    AbstractEstradiol (E2) plays an important role in controlling the homeostasis of body fluids. Several studies have reported the involvement of the hypothalamic pituitary adrenal axis (HPA) in the homeostatic control of hydromineral balance and the influence of estrogens on the modulation of this system. Nevertheless, until now, the physiological relevance of HPA axis activity on the hydromineral balance in females has not yet been fully elucidated. Therefore, the objective of the present study was to evaluate the effects of E2 (20μg/animal) pretreatment on neuroendocrine and hydroelectrolyte changes induced by adrenalectomy (ADX) with or without glucocorticoid hormone replacement (corticosterone, CORT; 10mg/kg) in ovariectomized rats (OVX). The results show that sodium appetite, natriuresis and the elevated plasma angiotensin II (ANG II) concentration induced by ADX were attenuated by E2 pretreatment. Additionally, a reduction of AT1 mRNA expression in the subfornical organ (SFO) and an increase in plasma atrial natriuretic peptide (ANP) concentrations by E2 pretreatment were observed. E2 pretreatment reversed the reduction in water intake induced by ADX in ADX CORT-replaced rats. Moreover, E2 pretreatment attenuated corticotropin releasing factor (CRF) mRNA expression in the paraventricular nucleus (PVN) induced by ADX. In contrast, E2 pretreatment increased CRF mRNA expression in the PVN in ADX CORT-replaced rats. Taken together, these results suggest that E2 has an important role in the modulation of behavioral and neuroendocrine responses involved in the maintenance of body fluid homeostasis in ADX rats with or without glucocorticoid replacement therapy

    The impact of the COVID-19 pandemic on the short-term survival of patients with cancer in Northern Portugal

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    The COVID-19 pandemic led to potential delays in diagnosis and treatment of cancer patients, which may negatively affect the prognosis of these patients. Our study aimed to quantify the impact of COVID-19 on the short-term survival of cancer patients by comparing a period of 4 months after the outbreak began (2 March 2020) with an equal period from 2019. All cancer cases of the esophagus, stomach, colon and rectum, pancreas, lung, skin-melanoma, breast, cervix, and prostate, from the Portuguese Oncology Institute of Porto (IPO-Porto) and diagnosed between 2 March and 1 July of 2019 (before COVID-19) and 2020 (after COVID-19) were identified. Information regarding sociodemographic, clinical and treatment characteristics were collected from the cancer registry database and clinical files. Vital status was assessed to 31 October of the respective years. Cox proportional hazards regression was used to estimate crude and propensity score-adjusted hazards ratio (HR) and 95% confidence intervals (95% CIs) of death. During follow-up to 31 October, there were 154 (11.8%) deaths observed before COVID-19 and 131 (17.2%) after COVID-19, corresponding to crude and adjusted HRs (95% CI) of 1.51 (1.20-1.91) and 1.10 (0.86-1.40), respectively. Significantly higher adjusted hazards of death were observed for patients with Stage III cancer (HR = 2.37; 95% CI: 1.14-4.94) and those undergoing surgical treatment (HR = 3.97; 95% CI: 1.14-13.77) or receiving radiotherapy (HR = 1.96; 95% CI: 1.96-3.74), while patients who did not receive any treatment had a lower mortality hazards (HR = 0.62; 95% CI: 0.46-0.83). The higher overall short-term mortality observed during the COVID-19 pandemic largely reflects the effects of the epidemic on the case-mix of patients being diagnosed with cancer.Funding information: European Regional Development Fund through the Operational Programme Competitiveness and Internationalization & Fundação para a Ciência e a Tecnologia, Grant/Award Number: POCI-01-0145-FEDER-032358; ref. PTDC/SAU-EPI/32358; Fundação para a Ciência e a Tecnologia, Grant/Award Number: info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB/04750/2020/PT; Fundação para a Ciência e a Tecnologia & Agency for Clinical Research and Biomedical Innovation, Grant/Award Number: RESEARCH 4 COVID-19 174_59685054

    The impact of the coronavirus disease 2019 pandemic on the diagnosis and treatment of cancer in Northern Portugal

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    Objectives The coronavirus disease 2019 (COVID-19) pandemic has affected the availability of healthcare resources, and adjustments to cancer care have been necessary considering the risk of morbidity by COVID-19 and of cancer progression. This study aims to quantify the impact of the COVID-19 pandemic on the care of patients with cancer by comparing a period of 4 months after the outbreak began (2 March 2020) with an equal period from 2019. Methods Cancer cases of the esophagus, stomach, colon and rectum, pancreas, lung, skin-melanoma, breast, cervix, prostate, non-Hodgkin lymphoma, and leukemia from the Portuguese Oncology Institute of Porto, and diagnosed between 2 March and 1 July 2019 (before COVID-19) and 2020 (after COVID-19) were identified. Those with the first treatment outside the Portuguese Oncology Institute of Porto were excluded. Sociodemographic, clinical and treatment characteristics were obtained from the cancer registry database and clinical files. Results The absolute number of new cancer cases decreased nearly 40% after the COVID-19 pandemic (from 1430 to 866). The largest decreases were observed for cervical (-74.3%) and prostate (-71.7%) cancers. Cases were more often diagnosed at more advanced stages in 2020 (P = 0.001), and the proportion of patients not starting any treatment until 1 July was just under 20% in 2019 and nearly 40% in 2020. The median times from symptoms onset, first medical exam and first appointment to diagnosis, and from diagnosis to first appointment, multidisciplinary tumor board meeting and first treatment were shorter after COVID-19. Conclusions There was a notable overall decrease in cancer diagnoses after COVID-19, with changes in the characteristics of incident cases. © 2022 Lippincott Williams and Wilkins. All rights reserved.This 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; UIDB/04750/2020). SM was 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 the European Regional Development Fund through the Operational Programme Competitiveness and Internationalization, and national funding from FCT. The funding sources had no involvement in the conduct of the research or preparation of the article

    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

    Mineração de dados para classificação das fases fenológicas da cultura da cana-de-açúcar utilizando dados do sensor modis e de precipitação.

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    RESUMO: Os dados do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) fornecem coberturas de áreas com grande extensão e alta periodicidade, características fundamentais que possibilitam o monitoramento de culturas agrícolas estratégicas para o Brasil, como a da cana-de-açúcar. A mineração de dados é uma abordagem promissora para melhorar a análise de dados de sensoriamento remoto. O objetivo deste trabalho foi aplicar técnicas de mineração de dados para classificação das fases fenológicas da cana-de-açúcar no Estado de São Paulo, utilizando dados MODIS e, também, de precipitação que auxiliam na caracterização do ciclo de desenvolvimento da cultura. As abordagens de seleção de atributos mostraram que todos os atributos do conjunto de dados foram considerados relevantes para a classificação. O balanceamento de classes pelo método de amostragem foi fundamental para melhorar a acurácia do modelo de classificação gerado pelo algoritmo J48. A descoberta do conhecimento pode ser feita através de regras de decisão relevantes para especialistas, revelando a aderência de técnicas de mineração de dados em problemas de classificação de imagens de satélite.SBIAgro 2011

    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
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