37 research outputs found
Geração de indicadores para periódicos científicos: um estudo na AtoZ
It presents the results from a proposal funded by an Institucional Notice. The funds received from the Federal University of Paraná were used to create a database that could generate some indicators for the academic online journal "AtoZ: new practices in information and knowledge". Based on a BibTeX set and the metadata extracted from the Open Journal System plataform, the results allowed an earnest data analysis that can support the decision-making process, as well as the potential use of the methodological procedures proposed for other journals
Geração de indicadores para periódicos científicos: um estudo na AtoZ
It presents the results from a proposal funded by an Institucional Notice. The funds received from the Federal University of Paraná were used to create a database that could generate some indicators for the academic online journal "AtoZ: new practices in information and knowledge". Based on a BibTeX set and the metadata extracted from the Open Journal System plataform, the results allowed an earnest data analysis that can support the decision-making process, as well as the potential use of the methodological procedures proposed for other journals
Content mining framework in social media: A FIFA world cup 2014 case analysis
© 2016 Elsevier B.V.This paper proposes a social media content mining framework that consists of seven phases. The framework was tested empirically during the FIFA World Cup 2014 at Curitiba (Brazil) as one of the main host city destinations. The research focused on the mining of Twitter content with tourist services ontology (hospitality, food and beverages, and transportation). In total, 58,686 valid messages were collected, analyzed, and associated with an application ontology. Content analysis demonstrated an accurate real-time reflection of tourism services. The framework is effective to collect relevant content and identify popular topics in social media toward strategic and operational tourism management
The proton-activated ovarian cancer G protein-coupled receptor 1 (OGR1) is responsible for renal calcium loss during acidosis.
Hypercalciuria is a common feature during metabolic acidosis and associates to nephrolithiasis and nephrocalcinosis. The mechanisms sensing acidosis and inducing increased urinary calcium excretion are still unknown. Here we tested whether mice deficient for proton-activated Ovarian cancer G-protein coupled receptor 1 (OGR1 or Gpr68) have reduced urinary excretion of calcium during chronic metabolic acidosis. In the kidney, OGR1 mRNA was found in cells of the glomerulus, proximal tubule, and interstitium including endothelial cells. Wild type (OGR1 <sup>+/+</sup> ) and OGR1 knockout (OGR1 <sup>-/-</sup> ) mice were given standard chow without (control) or loaded with ammonium chloride for one or seven days to induce acute or chronic metabolic acidosis, respectively. No differences in responding to the acid load were observed in the knockout mice, except for higher plasma bicarbonate after one day. Bone mineral density, resorption activity of osteoclasts, and urinary deoxypyridinoline were similar between genotypes. During metabolic acidosis the expression levels of key proteins involved in calcium reabsorption, i.e. the sodium/proton exchanger (NHE3), the epithelial calcium-selective channel TRPV5, and the vitamin D-dependent calcium binding protein calbindin-D28k were all higher in the knockout mice compared to wild type mice. This is consistent with the previous demonstration that OGR1 reduces NHE3 activity in proximal tubules of mice. Wild-type mice displayed a non-linear positive association between urinary proton and calcium excretion which was lost in the knockout mice. Thus, OGR1 is a pH sensor involved in the hypercalciuria of metabolic acidosis by controlling NHE3 activity in the proximal tubule. Hence, novel drugs modulating OGR1 activity may improve renal calcium handling
The elevation of circulating fibroblast growth factor 23 without kidney disease does not increase cardiovascular disease risk.
High circulating fibroblast growth factor 23 (FGF23) levels are probably a major risk factor for cardiovascular disease in chronic kidney disease. FGF23 interacts with the receptor FGFR4 in cardiomyocytes inducing left ventricular hypertrophy. Moreover, in the liver FGF23 via FGFR4 increases the risk of inflammation which is also found in chronic kidney disease. In contrast, X-linked hypophosphatemia is characterized by high FGF23 circulating levels due to loss of function mutations of the phosphate-regulating gene with homologies to an endopeptidase on the X chromosome (PHEX), but is not characterized by high cardiovascular morbidity. Here we used a novel murine X-linked hypophosphatemia model, the PhexC733RMhda mouse line, bearing an amino acid substitution (p.Cys733Arg) to test whether high circulating FGF23 in the absence of renal injury would trigger cardiovascular disease. As X-linked hypophosphatemia patient mimics, these mice show high FGF23 levels, hypophosphatemia, normocalcemia, and low/normal vitamin D levels. Moreover, these mice show hyperparathyroidism and low circulating soluble alpha Klotho levels. At the age of 27 weeks we found no left ventricular hypertrophy and no alteration of cardiac function as assessed by echocardiography. These mice also showed no activation of the calcineurin/NFAT pathway in heart and liver and no tissue and systemic signs of inflammation. Importantly, blood pressure, glomerular filtration rate and urea clearance were similar between genotypes. Thus, the presence of high circulating FGF23 levels alone in the absence of renal impairment and normal/high phosphate levels is not sufficient to cause cardiovascular disease
Systemic Jak1 activation provokes hepatic inflammation and imbalanced FGF23 production and cleavage.
Fibroblast growth factor 23 (FGF23) is a main regulator of mineral homeostasis. Low and high circulating FGF23 levels are associated with bone, renal, cardiovascular diseases, and increased mortality. Understanding the factors and signaling pathways affecting FGF23 levels is crucial for the management of these diseases and their complications. Here, we show that activation of the Jak1/Stat3 signaling pathway leads to inflammation in liver and to an increase in hepatic FGF23 synthesis, a key hormone in mineral metabolism. This increased synthesis leads to massive C-terminal FGF23 circulating levels, the inactive C-terminal fragment, and increased intact FGF23 levels, the active form, resulting in imbalanced production and cleavage. Liver inflammation does not lead to activation of the calcineurin-NFAT pathway, and no signs of systemic inflammation could be observed. Despite the increase of active intact FGF23, excessive C-terminal FGF23 levels block the phosphaturic activity of FGF23. Therefore, kidney function and renal αKlotho expression are normal and no activation of the MAPK pathway was detected. In addition, activation of the Jak1/Stat3 signaling pathway leads to high calcitriol levels and low parathyroid hormone production. Thus, JAK1 is a central regulator of mineral homeostasis. Moreover, this study also shows that in order to assess the impact of high FGF23 levels on disease and kidney function, the source and the balance in FGF23 production and cleavage are critical
Constitutive activation of Jak1 leads to increased fibroblast growth factor 23 levels in mice.
Meeting of the German Physiological Society (98th. 2019. Ulm, Germany