105 research outputs found

    Neuropilins 1 and 2 mediate neointimal hyperplasia and re-endothelialization following arterial injury

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    AIMS: Neuropilins 1 and 2 (NRP1 and NRP2) play crucial roles in endothelial cell migration contributing to angiogenesis and vascular development. Both NRPs are also expressed by cultured vascular smooth muscle cells (VSMCs) and are implicated in VSMC migration stimulated by PDGF-BB, but it is unknown whether NRPs are relevant for VSMC function in vivo. We investigated the role of NRPs in the rat carotid balloon injury model, in which endothelial denudation and arterial stretch induce neointimal hyperplasia involving VSMC migration and proliferation. METHODS AND RESULTS: NRP1 and NRP2 mRNAs and proteins increased significantly following arterial injury, and immunofluorescent staining revealed neointimal NRP expression. Down-regulation of NRP1 and NRP2 using shRNA significantly reduced neointimal hyperplasia following injury. Furthermore, inhibition of NRP1 by adenovirally overexpressing a loss-of-function NRP1 mutant lacking the cytoplasmic domain (ΔC) reduced neointimal hyperplasia, whereas wild-type (WT) NRP1 had no effect. NRP-targeted shRNAs impaired, while overexpression of NRP1 WT and NRP1 ΔC enhanced, arterial re-endothelialization 14 days after injury. Knockdown of either NRP1 or NRP2 inhibited PDGF-BB-induced rat VSMC migration, whereas knockdown of NRP2, but not NRP1, reduced proliferation of cultured rat VSMC and neointimal VSMC in vivo. NRP knockdown also reduced the phosphorylation of PDGFα and PDGFβ receptors in rat VSMC, which mediate VSMC migration and proliferation. CONCLUSION: NRP1 and NRP2 play important roles in the regulation of neointimal hyperplasia in vivo by modulating VSMC migration (via NRP1 and NRP2) and proliferation (via NRP2), independently of the role of NRPs in re-endothelialization

    Metals, environment and life interference of vanadium in living systems and their contextualization in teaching experimental sciences

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    The ammonium metavanadate (V + 5), widely used in chemical industry is a toxic compound which is involved in several cases of enzyme inhibition. The alkaline phosphatase (ALP) a zincglycoenzyme implicated in cell growth and apoptosis can be affected by the presence of metals like vanadium. The main objective of this study was to interest young students to the toxicity of metals, exploring the effects of vanadium on the ALP activity, using Saccharomyces cerevisiae as biological model. This activity was developed by a pilot group of students from Dom Manuel Martins high school of Setúbal, Portugal, which follow the yeast growth at 640nm and obtained cell extracts from S. cerevisiae growing at 28 ◦C in YPD medium (glucose 2% (w / v)) in absence and presence of 25 or 75mM NH4VO3, for the quantification of proteins at 720nm by Lowry’s method and ALP activity determination at 405 nm, using pNPP as substrate. The young people observed a growth inhibition of yeast cells exposed to vanadium as well as a decrease of total proteins and ALP activity level, facts which put in evidence a sharp toxicological effect of vanadium in eukaryotic cell. The average score obtained before and after the experimental activity (41%) and (63%), respectively, using the same set of questionsproblem, revealed an overall positive performance of skills developed by students, in the scope of metals toxicological effects in eukaryote cells. In more detail, it was also observed a positive and significant effect in each experimental phase (p < 0.05), before and after the development of the action. The assessment of skills developed by students showed an improvement of their compliance level, thereby acquiring a significant learning. The results for the opinion survey showed that most respondents classified the activity and its difficulty degree as good

    Pseudoscalars Mesons in Hot, Dense Matter

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    Phase transitions in hot and dense matter and the in--medium behavior of pseudoscalar mesons (π±,π0,K±,K0,Kˉ0,ηandη\pi^{\pm}, \pi^0, K^{\pm}, K^0 ,\bar K^0,\eta {and} \eta' ) are investigated, in the framework of the three flavor Nambu--Jona-Lasinio model, including the 't Hooft interaction, which breaks the UA(1)U_A(1) symmetry. Three different scenarios are considered: zero density and finite temperature, zero temperature and finite density in quark matter with different degrees of strangeness, and finite temperature and density. At T=0, the role of strange valence quarks in the medium is discussed, in connection with the phase transition and the mesonic behavior. It is found that the appearance of strange quarks, above certain densities, leads to meaningful changes in different observables, especially in matter with \betaequilibrium.Thebehaviorofmesonsinthe --equilibrium. The behavior of mesons in the T-\rho$ plane is analyzed in connection with possible signatures of restoration of symmetries.Comment: 33 pages, 12 figures, PRC versio

    Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

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    The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor gamma (PPAR gamma), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 mu M) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs

    Choledocal cysts: spectrum of imaging findings

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    Preschool literacy and reading performance in primary school

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    A literacia pré-escolar tem recebido uma crescente atenção. Neste estudo, participaram 70 crianças que iniciaram o 1.º ano de escolaridade no ano letivo 2009/10 e que, na educação pré-escolar, frequentaram três instituições com abordagens diferenciadas de leitura e de escrita. O estudo inclui quatro medidas repetidas no tempo nas áreas da fonologia, reconhecimento de letras, palavras e velocidade de leitura. Os resultados sugerem que a abordagem específica à leitura na educação pré-escolar condiciona o desempenho da leitura na instrução primária. Contudo, essa influência parece ser atenuada com o tempo. Por outro lado, verificou-se que sujeitos que receberam instrução direta de leitura em idade pré-escolar (mas não treino fonológico) obtêm resultados significativamente superiores em tarefas fonológicas aos de sujeitos que receberam treino fonológico prolongado (mas não de leitura).The debate regarding kindergarten literacy has received increasing attention and social visibility. In this study, participants are 70 children who attended first grade in 2009/2010. Participants attended three kindergartens with unique approaches to reading. A four wave repeated measure design was conducted to investigate the growth of the children in phonological awareness, letter recognition, word recognition, and reading speed. Results suggest that the approach towards reading and writing in kindergarten affects children's performance in grades 1 and 2 of elementary school. This influence, however, seems to fade over time. Moreover, results show that children who received formal reading instruction in kindergarten, perform significantly better in phonological tasks than children who received direct and extended phonological instruction.(undefined)info:eu-repo/semantics/publishedVersio

    Current and novel therapeutic opportunities for systemic therapy in biliary cancer

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    none24Biliary tract cancers (BTCs) are a group of rare and aggressive malignancies that arise in the biliary tree within and outside the liver. Beyond surgical resection, which is beneficial for only a small proportion of patients, current strategies for treating patients with BTCs include chemotherapy, as a single agent or combination regimens, in the adjuvant and palliative setting. Increased characterisation of the molecular landscape of these tumours has facilitated the identification of molecular vulnerabilities, such as IDH mutations and FGFR fusions, that can be exploited for the treatment of BTC patients. Beyond targeted therapies, active research avenues explore the development of novel therapeutics that target the crosstalk between cancer and stroma, the cellular pathways involved in the regulation of cell death, the chemoresistance phenotype and the dysregulation of RNA. In this review, we discuss the therapeutic opportunities currently available in the management of BTC patients, and explore the strategies that can support the implementation of precision oncology in BTCs, including novel molecular targets, liquid biopsies and patient-derived predictive tools.openMarin J.J.G.; Prete M.G.; Lamarca A.; Tavolari S.; Landa-Magdalena A.; Brandi G.; Segatto O.; Vogel A.; Macias R.I.R.; Rodrigues P.M.; Casta A.L.; Mertens J.; Rodrigues C.M.P.; Fernandez-Barrena M.G.; Da Silva Ruivo A.; Marzioni M.; Mentrasti G.; Acedo P.; Munoz-Garrido P.; Cardinale V.; Banales J.M.; Valle J.W.; Bridgewater J.; Braconi C.Marin, J. J. G.; Prete, M. G.; Lamarca, A.; Tavolari, S.; Landa-Magdalena, A.; Brandi, G.; Segatto, O.; Vogel, A.; Macias, R. I. R.; Rodrigues, P. M.; Casta, A. L.; Mertens, J.; Rodrigues, C. M. P.; Fernandez-Barrena, M. G.; Da Silva Ruivo, A.; Marzioni, M.; Mentrasti, G.; Acedo, P.; Munoz-Garrido, P.; Cardinale, V.; Banales, J. M.; Valle, J. W.; Bridgewater, J.; Braconi, C

    Response of the Diatom Phaeodactylum tricornutum to Photooxidative Stress Resulting from High Light Exposure

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    The response of microalgae to photooxidative stress resulting from high light exposure is a well-studied phenomenon. However, direct analyses of photosystem II (PSII) D1 protein (the main target of photoinhibition) in diatoms are scarce. In this study, the response of the diatom model species Phaeodactylum tricornutum to short-term exposure to high light was examined and the levels of D1 protein determined immunochemically. Low light (LL) acclimated cells (40 µmol photons m−2 s−1) subjected to high light (HL, 1,250 µmol photons m−2 s−1) showed rapid induction of non-photochemical quenching (NPQ) and ca. 20-fold increase in diatoxanthin (DT) concentration. This resulted from the conversion of diadinoxanthin (DD) to DT through the activation of the DD-cycle. D1 protein levels under LL decreased about 30% after 1 h of the addition of lincomycin (LINC), a chloroplast protein synthesis inhibitor, showing significant D1 degradation and repair under low irradiance. Exposure to HL lead to a 3.2-fold increase in D1 degradation rate, whereas average D1 repair rate was 1.3-x higher under HL than LL, leading to decreased levels of D1 protein under HL. There were significant effects of both HL and LINC on P. tricornutum maximum quantum yield of PSII (Fv/Fm), showing a reduction of active PSII reaction centres. Partial recovery of Fv/Fm in the dark demonstrates the photosynthetic resilience of this diatom to changes in the light regime. P. tricornutum showed high allocation of total protein to D1 and an active D1-repair cycle to limit photoinhibition

    Autophagy and ATP-induced anti-apoptosis in antigen presenting cells (APC) follows the cytokine storm in patients after major trauma

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    Severe trauma and the systemic inflammatory response syndrome (SIRS) occur as a result of a cytokine storm which is in part due to ATP released from damaged tissue. This pathology also leads to increased numbers of immature antigen presenting cells (APC) sharing properties of dendritic cells (DC) or macrophages (MΦ). The occurrence of immature APC appears to coincide with the reactivation of herpes virus infections such as Epstein Barr virus (EBV). The aim of this study was the comparative analysis of the ultrastructural and functional characteristics of such immature APC. In addition, we investigated EBV infection/ reactivation and whether immature APC might be targets for natural killers (NK). Significant macroautophagy, mitochondrial degradation and multivesicular body formation together with the identification of herpes virus particles were morphological findings associated with immature APC. Exogenous stressors such as ATP further increased morphological signs of autophagy, including LC3 expression. Functional tests using fluorescent bacteria proved impaired phagolysosome fusion. However, immature APC were susceptible to NK-92-mediated cytolysis. We found evidence for EBV latency state II infection by detecting EBV-specific LMP1 and EBNA2 in immature APC and in whole blood of these patients. In summary, trauma-induced cytokine storms may induce maturation arrest of APC, promote ATP-induced autophagy, support EBV persistence and impair the degradation of phagocytozed bacteria through inefficient phagolysosome fusion. The susceptibility to NK-mediated cytolysis supports the hypothesis that NK function is likely to contribute to immune reconstitution after major trauma by regulating immature APC, and ATP-induced autophagy and survival
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