175 research outputs found

    Crystallization and preliminary X-ray characterization of 1,3-propanediol dehydrogenase from the human pathogen Klebsiella pneumoniae

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    1,3-Propanediol dehydrogenase from K. pneumoniae has been overexpressed in E. coli, purified and crystallized. Diffraction data have been collected to 2.7 Å resolution

    Stratification of ST-Elevation Myocardial Infarction Patients Based on Soluble CD40L Longitudinal Changes

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    Involvement of soluble CD40 ligand (sCD40L) in thrombosis and inflammation on the context of coronary artery disease is currently being revised. In that perspective, we had studied the association of sCD40L with markers of platelet activation and markers of endothelial and vascular function. On that cohort, a stratification of patients with acute myocardial infarction (AMI) 1 month after percutaneous coronary intervention (PCI) was observed based on concentrations of sCD40L. The study intended to identify the groups of AMI patients with different profiles of sCD40L concentrations and verify how medication, clinical evolution, biochemical data, and markers of regulation of endothelial function at genetic (endothelial nitric oxide synthase polymorphisms) and post-transcriptional levels (circulating microRNAs) affect sCD40L serum levels. Lower quartiles of sCD40L (<2.3 ng/mL) were associated with higher concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP), high frequency of G894T polymorphism, and altered expression of a set of microRNAs assumed to be involved in the regulation of endothelial and cardiac function and myocardium hypertrophy, relative to patients in sCD40L upper quartiles. A characteristic sCD40L variation pattern in STEMI patients was identified. Low levels of sCD40L 1 month after PCI distinguish STEMI patients with worse prognosis, a compromised cardiac healing, and a persistent endothelial dysfunction, as given by the association between sCD40L, NT-proBNP, G894T polymorphism, and specific profile of miRNA expression. These results suggest sCD40L could have a prognostic value in STEMI patients.info:eu-repo/semantics/publishedVersio

    (I)Migrantes, diversidades e desigualdades no sistema educativo português : balanço e perspectivas

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    O objectivo do presente artigo consiste em procurar transmitir um olhar sociologicamente informado no que concerne à situação portuguesa no domínio das políticas educativas públicas e investigações produzidas relacionadas com o sistema educativo e a (i)migração, ou seja, com a tentativa de construção de uma educação intercultural. Neste sentido, será realizada uma análise descritiva e compreensivo-interpretativa da evolução desta problemática em Portugal desde que a mesma se tornou objecto de reflexão por parte de investigadores/as e políticos nos finais da década de oitenta, início da década de noventa do século XX. Nesta análise, será dada ênfase às investigações e quadros teóricos produzidos e às medidas legislativas e políticas educativas no domínio do tratamento da diferença cultural dentro do sistema educativo português.The aim of this article consists in attempting to transmit a sociologically informed view in what the Portuguese situation in the field of public policies and research related to the educational system and (im)migration are concerned, that is, in attempting to construct an intercultural education. In this way, a descriptive and comprehensiveinterpretative analysis of the evolution of this problem in Portugal will be realized, since the latter became an object of reflection on the part of researchers and politicians towards the end of the 80s, the beginning of the 90s of the XXth century. In this analysis, emphasis will be given on the research and theoretical frameworks produced and on the legislative measures and educational policies in the field of treating cultural difference in the Portuguese educational system

    Validation of a Novel, Sensitive, and Specific Urine-Based Test for Recurrence Surveillance of Patients With Non-Muscle-Invasive Bladder Cancer in a Comprehensive Multicenter Study

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    Bladder cancer (BC), the most frequent malignancy of the urinary system, is ranked the sixth most prevalent cancer worldwide. Of all newly diagnosed patients with BC, 70–75% will present disease confined to the mucosa or submucosa, the non-muscle-invasive BC (NMIBC) subtype. Of those, approximately 70% will recur after transurethral resection (TUR). Due to high rate of recurrence, patients are submitted to an intensive follow-up program maintained throughout many years, or even throughout life, resulting in an expensive follow-up, with cystoscopy being the most cost-effective procedure for NMIBC screening. Currently, the gold standard procedure for detection and follow-up of NMIBC is based on the association of cystoscopy and urine cytology. As cystoscopy is a very invasive approach, over the years, many different noninvasive assays (both based in serum and urine samples) have been developed in order to search genetic and protein alterations related to the development, progression, and recurrence of BC. TERT promoter mutations and FGFR3 hotspot mutations are the most frequent somatic alterations in BC and constitute the most reliable biomarkers for BC. Based on these, we developed an ultra-sensitive, urine-based assay called Uromonitor®, capable of detecting trace amounts of TERT promoter (c.1-124C > T and c.1-146C > T) and FGFR3 (p.R248C and p.S249C) hotspot mutations, in tumor cells exfoliated to urine samples. Cells present in urine were concentrated by the filtration of urine through filters where tumor cells are trapped and stored until analysis, presenting long-term stability. Detection of the alterations was achieved through a custom-made, robust, and highly sensitive multiplex competitive allele-specific discrimination PCR allowing clear interpretation of results. In this study, we validate a test for NMIBC recurrence detection, using for technical validation a total of 331 urine samples and 41 formalin-fixed paraffin-embedded tissues of the primary tumor and recurrence lesions from a large cluster of urology centers. In the clinical validation, we used 185 samples to assess sensitivity/specificity in the detection of NMIBC recurrence vs. cystoscopy/cytology and in a smaller cohort its potential as a primary diagnostic tool for NMIBC. Our results show this test to be highly sensitive (73.5%) and specific (93.2%) in detecting recurrence of BC in patients under surveillance of NMIBC.This study was supported by FCT (“Portuguese Foundation for Science and Technology”) through a PhD grant to RB (SFRH/ BD/111321/2015). Further funding was obtained from the project “Advancing cancer research: from basic knowledge to application” NORTE-01-0145-FEDER-000029: “Projetos Estruturados de I & D & I,” funded by Norte 2020—Programa Operacional Regional do Norte. This article is a result of the project PTDC/MED-ONC/31438/2017 (The Other Faces of Telomerase: Looking beyond Tumor Immortalization), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI) and by Portuguese funds through FCT. Further funding by the European Regional Development Fund (ERDF) through the Operational Programme for Competitiveness and Internationalisation— COMPETE 2020, and Portuguese national funds via FCT, under project POCI-01-0145-FEDER-016390:CANCEL STEM

    Characterization of an Alkali- and Halide-Resistant Laccase Expressed in E. coli: CotA from <i>Bacillus clausii</i>

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    The limitations of fungal laccases at higher pH and salt concentrations have intensified the search for new extremophilic bacterial laccases. We report the cloning, expression, and characterization of the bacterial cotA from Bacillus clausii, a supposed alkalophilic ortholog of cotA from B. subtilis. Both laccases were expressed in E. coli strain BL21(DE3) and characterized fully in parallel for strict benchmarking. We report activity on ABTS, SGZ, DMP, caffeic acid, promazine, phenyl hydrazine, tannic acid, and bilirubin at variable pH. Whereas ABTS, promazine, and phenyl hydrazine activities vs. pH were similar, the activity of B. clausii cotA was shifted upwards by ~0.5-2 pH units for the simple phenolic substrates DMP, SGZ, and caffeic acid. This shift is not due to substrate affinity (K(M)) but to pH dependence of catalytic turnover: The k(cat) of B. clausii cotA was 1 s⁻¹ at pH 6 and 5 s⁻¹ at pH 8 in contrast to 6 s⁻¹ at pH 6 and 2 s⁻¹ at pH 8 for of B. subtilis cotA. Overall, k(cat)/K(M) was 10-fold higher for B. subtilis cotA at pH(opt). While both proteins were heat activated, activation increased with pH and was larger in cotA from B. clausii. NaCl inhibited activity at acidic pH, but not up to 500-700 mM NaCl in alkaline pH, a further advantage of the alkali regime in laccase applications. The B. clausii cotA had ~20 minutes half-life at 80°C, less than the ~50 minutes at 80°C for cotA from B. subtilis. While cotA from B. subtilis had optimal stability at pH~8, the cotA from B. clausii displayed higher combined salt- and alkali-resistance. This resistance is possibly caused by two substitutions (S427Q and V110E) that could repel anions to reduce anion-copper interactions at the expense of catalytic proficiency, a trade-off of potential relevance to laccase optimization
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