272 research outputs found

    Adrenal Steroids Modulate Fibroblast-Like Synoviocytes Response During B. abortus Infection

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    Brucella abortus stimulates an inflammatory immune response that stimulates theendocrine system, inducing the secretion of dehydroepiandrosterone (DHEA) andcortisol. In humans, the active disease is generally present as osteoarticular brucellosis.In previous studies we showed that B. abortus infection of synoviocytes creates aproinflammatory microenvironment. We proposed to determine the role of cortisoland DHEA on synoviocytes and infiltrating monocytes during B. abortus infection.Cortisol inhibited IL-6, IL-8, MCP-1, and MMP-2 secretion induced by B. abortusinfection in synovial fibroblast. Cortisol-mediated MMP-2 inhibition during B. abortusinfection was reversed by IL-6. DHEA inhibited B. abortus-induced RANKL up-regulationin synovial fibroblast through estrogen receptor (ER). B. abortus infection did notmodulate glucocorticoid receptor (GR) expression. Cell responses to cortisol alsodepended on its intracellular bioavailability, according to the activity of the isoenzymes11b-hydroxysteroid dehydrogenase (HSD) type-1 and 11b-HSD2 (which are involvedin cortisone-cortisol interconversion). B. abortus infection did not modify 11b-HSD1expression and GRa/b ratio in the presence or absence of adrenal steroids. Supernatantsfrom B. abortus-infected monocytes induced 11b-HSD1 in synovial cells. Administrationof cortisone was capable of inhibiting the secretion of RANKL by synoviocytes mimickingcortisol?s effect. These results go along with previous observations that highlighted theability of synovial tissue to secrete active steroids, making it an intracrine tissue. This isthe first study that contributes to the knowledge of the consequence of adrenal steroidson synoviocytes in the context of a bacterial infection.Fil: Gentilini, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Giambartolomei, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Delpino, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentin

    Mutational Analysis of c-KIT and PDGFRA in Canine Gastrointestinal Stromal Tumors (GISTs)

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    Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the canine gastrointestinal tract and are diagnosed by the immunohistochemical expression of the receptor tyrosine kinase (RTK) KIT. Activating mutations of the proto-oncogenes c-KIT and PDGFRA drive GIST oncogenesis and are used to predict the response to RTK-inhibitors in human oncology. Currently, the frequency and significance of these mutations in canine GIST have not been adequately explored. Therefore, we investigated the mutational status of c-KIT (exons 9, 11 and 13) and PDGFRA (exons 12 and 18) genes by PCR followed by fragment analysis for c-KIT deletions and PCR followed by screening with DHPLC and direct sequencing confirmation for single nucleotide variations in 17 formalin-fixed paraffin-embedded canine GISTs confirmed by KIT immunopositivity. c-KIT mutations were detected in 47% of cases, with a mutation detection rate significantly higher (p = 0.0004, Fisher's exact test) and always involving exon 11. A PDGFRA gene mutation (exon 18) was identified in one case. Even if follow-up data were not available for all cases, four cases with documented abdominal metastases displayed c-KIT mutations. These data confirm that c-KIT exon 11 mutations occur frequently in canine GISTs, and identify the presence of a PDGFRA mutation similar to human GISTs. This study also suggests a potential association of c-KIT mutation with more aggressive biological behavior

    The European Flood Alert System EFAS - Part 2: Statistical Skill Assessment of Probabilistic and Deterministic Operational Forecasts

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    Since 2005 the European Flood Alert System (EFAS) has been producing probabilistic hydrological forecasts in pre-operational mode at the Joint Research Centre (JRC) of the European Commission. EFAS aims at increasing preparedness for floods in trans-national European river basins by providing medium-range deterministic and probabilistic flood forecasting information from 3 to 10 days in advance, to national hydrometeorological services. This paper is Part 2 of a study presenting the development and skill assessment of EFAS. In Part 1, the scientific approach adopted in the development of the system has been presented, as well as its basic principles and forecast products. In the present article, two years of existing operational EFAS forecasts are statistically assessed and the skill of EFAS forecasts is analysed with several skill scores. The analysis is based on the comparison of threshold exceedances between proxy-observed and forecasted discharges. Skill is assessed both with and without taking into account the persistence of the forecasted signal during consecutive forecasts. Skill assessment approaches are mostly adopted from meteorology and the analysis also compares probabilistic and deterministic aspects of EFAS. Furthermore, the utility of different skill scores is discussed and their strengths and shortcomings illustrated. The analysis shows the benefit of incorporating past forecasts in the probability analysis, for medium-range forecasts, which effectively increases the skill of the forecasts.JRC.A.1-Work programme E

    Physical realization of the Glauber quantum oscillator

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    More than thirty years ago Glauber suggested that the link between the reversible microscopic and the irreversible macroscopic world can be formulated in physical terms through an inverted harmonic oscillator describing quantum amplifiers. Further theoretical studies have shown that the paradigm for irreversibility is indeed the reversed harmonic oscillator. As outlined by Glauber, providing experimental evidence of these idealized physical systems could open the way to a variety of fundamental studies, for example to simulate irreversible quantum dynamics and explain the arrow of time. However, supporting experimental evidence of reversed quantized oscillators is lacking. We report the direct observation of exploding n = 0 and n = 2 discrete states and Γ0 and Γ2 quantized decay rates of a reversed harmonic oscillator generated by an optical photothermal nonlinearity. Our results give experimental validation to the main prediction of irreversible quantum mechanics, that is, the existence of states with quantized decay rates. Our results also provide a novel perspective to optical shock-waves, potentially useful for applications as lasers, optical amplifiers, white-light and X-ray generation

    Bortezomib a Safe Treatment for Patients with Multiple Myeloma and Cystic Fibrosis

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    Introduction: Bortezomib is a proteasome inhibitor that targets myeloma cell and its bone marrow micro-environment. Intravenous Bortezomib (1.3 mg/m2 administered on days 1,4,8 and 11 of a 21 day cycle), with or without dexamethasone, is effective and well tolerated in patients with relapsed/refractory multiple myeloma (MM). Methods:  We treated a MM patient with Cystic Fibrosis with Bortezomib alone to avoid the use of corticosteroid and consequently the risk of lung infection reactivations, first of all due to the patient Pseudomonas aeruginosa colonization. Bortezomib was administrated at 1.3 mg/m2 on days 1,4,8 and 11 with a 10 day rest period  and four 21-day cycles were administered. We evaluate the treatment response and toxicity. Results: After four cycles of therapy the patient achieved a  very good partial response (VGPR) according to the IMWG response criteria, without clinically significant side effects. Conclusions: Bortezomib can be successfully utilized for the management of this difficult disease situatio

    Altered modulation of lamin A/C-HDAC2 interaction and p21 expression during oxidative stress response in HGPS

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    Defects in stress response are main determinants of cellular senescence and organism aging. In fibroblasts from patients affected by Hutchinson-Gilford progeria, a severe LMNA-linked syndrome associated with bone resorption, cardiovascular disorders, and premature aging, we found altered modulation of CDKN1A, encoding p21, upon oxidative stress induction, and accumulation of senescence markers during stress recovery. In this context, we unraveled a dynamic interaction of lamin A/C with HDAC2, an histone deacetylase that regulates CDKN1A expression. In control skin fibroblasts, lamin A/C is part of a protein complex including HDAC2 and its histone substrates; protein interaction is reduced at the onset of DNA damage response and recovered after completion of DNA repair. This interplay parallels modulation of p21 expression and global histone acetylation, and it is disrupted by LMNAmutations leading to progeroid phenotypes. In fact, HGPS cells show impaired lamin A/C-HDAC2 interplay and accumulation of p21 upon stress recovery. Collectively, these results link altered physical interaction between lamin A/C and HDAC2 to cellular and organism aging. The lamin A/C-HDAC2 complex may be a novel therapeutic target to slow down progression of progeria symptoms

    Rapid and Affordable High Throughput Screening of SARS-CoV-2 Variants Using Denaturing High-Performance Liquid Chromatography Analysis

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    Mutations in the receptor binding domain (RBD) of SARS-CoV-2 alter the infectivity, pathogenicity, and transmissibility of new variants of concern (VOCs). In addition, those mutations cause immune escape, undermining the population immunity induced by ongoing mass vaccination programs. There is an urgent need for novel strategies and techniques aimed at the surveillance of the active emergence and spread of the VOCs. The aim of this study was to provide a quick, cheap and straightforward denaturing high-performance liquid chromatography (DHPLC) method for the prompt identification of the SARS-CoV-2 VOCs. Two PCRs were designed to target the RBD region, spanning residues N417 through N501 of the Spike protein. Furthermore, a DHPLC screening analysis was set up. The screening consisted of mixing the unknown sample with a standard sample of a known variant, denaturing at high temperature, renaturing at room temperature followed by a 2-minute run using the WAVE DHPLC system to detect the heteroduplexes which invariably form whenever the unknown sample has a nucleotide difference with respect to the standard used. The workflow was able to readily detect all the variants including B.1.1.7, P.1, B.1.585 B.1. 617.2 and lineages at a very affordable cost. The DHPLC analysis was robust being able to identify variants, even in the case of samples with very unbalanced target concentrations including those samples at the limit of detection. This approach has the potential of greatly expediting surveillance of the SARS-CoV-2 variants

    PRKG2 Splice Site Variant in Dogo Argentino Dogs with Disproportionate Dwarfism

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    Dwarfism phenotypes occur in many species and may be caused by genetic or environmental factors. In this study, we investigated a family of nine Dogo Argentino dogs, in which two dogs were affected by disproportionate dwarfism. Radiographs of an affected dog revealed a decreased level of endochondral ossification in its growth plates, and a premature closure of the distal ulnar physes. The pedigree of the dogs presented evidence of monogenic autosomal recessive inheritance; combined linkage and homozygosity mapping assigned the most likely position of a potential genetic defect to 34 genome segments, totaling 125 Mb. The genome of an affected dog was sequenced and compared to 795 control genomes. The prioritization of private variants revealed a clear top candidate variant for the observed dwarfism. This variant, PRKG2:XM_022413533.1:c.1634+1G>T, affects the splice donor site and is therefore predicted to disrupt the function of the PKRG2 gene encoding protein, kinase cGMP-dependent type 2, a known regulator of chondrocyte differentiation. The genotypes of the PRKG2 variant were perfectly associated with the phenotype in the studied family of dogs. PRKG2 loss-of-function variants were previously reported to cause disproportionate dwarfism in humans, cattle, mice, and rats. Together with the comparative data from other species, our data strongly suggest PRKG2:c.1634+1G>T to be a candidate causative variant for the observed dwarfism phenotype in Dogo Argentino dogs

    Promoção de estratégias de aprendizagem no Ensino Superior: desafios para aprender

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    This study objective was to analyze contributions from “How to learn at the university?” workshop, offered to students from different undergraduate careers at a Public University. The workshop sought to identify learning challenges, self-harmful strategies, and to create opportunities for self-regulation of student learning. According to the results, the students' challenges are related to time management and lack of organization to study, and the most punctuated self-harm strategy was procrastination. The research showed that changes and advances in the behavior of students to learn are possible as long as they want and have opportunities for this.El objetivo de este estudio fue analizar las contribuciones del taller “¿Cómo aprender en la universidad?”, ofrecido a estudiantes de diferentes carreras de una Universidad Pública. El taller buscó identificar los desafíos para aprender estrategias auto perjudiciales, y profundizar la autorregulación del aprendizaje de los estudiantes. Conforme a los resultados, los desafíos de los estudiantes están relacionados a la gestión del tiempo, y a la falta de organización para estudiar, siendo que la estrategia auto perjudicial más destacada fue la procrastinación. La investigación mostró que son posibles los cambios y avances en el comportamiento de los estudiantes para aprender siempre que ellos quieran, y tengan oportunidades para este propósito.O objetivo deste estudo foi analisar contribuições da oficina “Como aprender na universidade?”, oferecida a estudantes de diferentes cursos de graduação de uma Universidade Pública. A oficina buscou identificar desafios para aprender, estratégias autoprejudiciais e oportunizar a autorregulação da aprendizagem dos estudantes. Conforme os resultados, os desafios dos estudantes estão relacionados à gestão do tempo e à falta de organização para estudar, sendo que a estratégia autoprejudicial mais pontuada foi a procrastinação. A pesquisa mostrou que são possíveis mudanças e avanços no comportamento dos estudantes para aprender desde que esses queiram e tenham oportunidades para esse propósito
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