Ocular adnexal (orbital) solitary fibrous tumor: nuclear STAT6 expression and literature review.

PURPOSE: To report the clinico-pathological features of solitary fibrous tumor occurring in the ocular adnexa (OA) in a single center. To assess the presence of NAB2-STAT6 genes fusion in OA solitary fibrous tumor detected by nuclear overexpression of STAT6. METHODS: Retrospective study including orbital and OA solitary fibrous tumors treated between 2006 and 2014 in our center. The clinical, radiological, and histopathological findings were evaluated. STAT6 expression was assessed by immunohistochemistry. RESULTS: Five patients were identified and presented with a chronic OA mass. The tumors were radiologically well delimited, highly vascularized and without bone erosion. All the patients underwent complete surgical excision. Pathological examination confirmed solitary fibrous tumor in all cases. All tumors demonstrated a nuclear expression of STAT6. There were no recurrences, with a mean follow-up of 5 years after surgery. Our review demonstrated that proptosis was the most common presentation occurring in 60 % of the cases. In the ocular adnexa, adverse histological criteria were found in 19.7 % of the tumors, and recurrences were observed in 48 % of these cases. Thirty-six percent of patients presented at least one local recurrence, and metastastic spread was found in 2.4 % of the cases. Tumor-related death was described in two cases. CONCLUSION: Ocular adnexal SFT are rare and usually present as a chronic orbital mass with proptosis. In the OA, solitary fibrous tumor demonstrates STAT6 nuclear expression, as documented in other locations. Recurrences are unusual and metastasis exceptional. Initial surgical resection should be complete in order to avoid recurrence.

Digitalización del sistema de control de nivel en calentadores y tanques de drenaje de una Central Nuclear

Contexto Una central nuclear, al igual que cualquier otro tipo de central generadora de energía eléctrica, mediante turbinas de vapor, está basada en un proceso termodinámico. El rendimiento de las mismas es función del salto entálpico del vapor, para mejorarlo las centrales están constituidas por un ciclo compound formado por turbina de alta presión y turbinas de baja presión, y un ciclo regenerativo consistente en calentar el agua de alimentación antes de su introducción a los generadores de vapor. Un ciclo regenerativo está basado en etapas de calentadores o cambiadores de calor para aprovechar al máximo la energía térmica del vapor, este proyecto está basado en la mejora y optimización del proceso de control de estos para contribuir a mejorar el rendimiento de la central. Objetivo Implementar un sistema de control que nos permita modernizar los clásicos sistemas basados en controles locales y comunicaciones analógicas. Mejorar el rendimiento del ciclo regenerativo de la central, aprovechando las mejoras tecnológicas que ofrece el mercado, tanto en el hardware como en el software de los sistemas de instrumentación y control. Optimizar el rendimiento de los lazos de control de cada uno de los elementos del ciclo regenerativo mediante estrategias de control. Procedimiento Desarrollo de un sistema de control actualizado considerando, como premisa principal, la fiabilidad del sistema, el análisis de fallos y la jerarquización del riesgo. Análisis y cálculo de los lazos de control considerando las premisas establecidas. Configuración de los lazos mediante estrategias de control que nos permitan optimizar y minimizar los efectos del fallo. Para ello se han utilizado parámetros y datos extraídos de la Central Nuclear de Ascó. Conclusiones Se ha modernizado y optimizado el sistema de control mejorando el rendimiento del ciclo regenerativo. Se ha conseguido un sistema más fiable, reduciendo el riesgo del fallo y disminuyendo los efectos de los mismos. El coste de un proyecto de estas características es inferior al de un sistema convencional y ofrece más posibilidades. Es un sistema abierto que permite utilizar e interconectar equipos de diferentes fabricantes, lo que favorece tanto el mantenimiento como las posibles ampliaciones futuras del sistema.

Metabolic and structural rearrangement during dark-induced autophagy in soybean (Glycine max L.) nodules: An electron microscopy and P-31 and C-13 nuclear magnetic resonance study

The effects of dark-induced stress on the evolution of the soluble metabolites present in senescent soybean (Glycine max L.) nodules were analysed in vitro using C-13- and P-31-NMR spectroscopy. Sucrose and trehalose were the predominant soluble storage carbons. During dark-induced stress, a decline in sugars and some key glycolytic metabolites was observed. Whereas 84% of the sucrose disappeared, only one-half of the trehalose was utilised. This decline coincides with the depletion of Gln, Asn, Ala and with an accumulation of ureides, which reflect a huge reduction of the N-2 fixation. Concomitantly, phosphodiesters and compounds like P-choline, a good marker of membrane phospholipids hydrolysis and cell autophagy, accumulated in the nodules. An autophagic process was confirmed by the decrease in cell fatty acid content. In addition, a slight increase in unsaturated fatty acids (oleic and linoleic acids) was observed, probably as a response to peroxidation reactions. Electron microscopy analysis revealed that, despite membranes dismantling, most of the bacteroids seem to be structurally intact. Taken together, our results show that the carbohydrate starvation induced in soybean by dark stress triggers a profound metabolic and structural rearrangement in the infected cells of soybean nodule which is representative of symbiotic cessation.

Postnatal β-cell maturation is associated with islet-specific microRNA changes induced by nutrient shifts at weaning.

Glucose-induced insulin secretion is an essential function of pancreatic β-cells that is partially lost in individuals affected by Type 2 diabetes. This unique property of β-cells is acquired through a poorly understood postnatal maturation process involving major modifications in gene expression programs. Here we show that β-cell maturation is associated with changes in microRNA expression induced by the nutritional transition that occurs at weaning. When mimicked in newborn islet cells, modifications in the level of specific microRNAs result in a switch in the expression of metabolic enzymes and cause the acquisition of glucose-induced insulin release. Our data suggest microRNAs have a central role in postnatal β-cell maturation and in the determination of adult functional β-cell mass. A better understanding of the events governing β-cell maturation may help understand why some individuals are predisposed to developing diabetes and could lead to new strategies for the treatment of this common metabolic disease.

Versatility of field theory motivated nuclear effective Lagrangian approach

We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei.

Mechanisms of OGT-mediated HCF-1 protein maturation

Post-translational protein modifications are crucial for many fundamental cellular and extracellular processes and greatly contribute to the complexity of organisms. Human HCF-1 is a transcriptional co-regulator that undergoes complex protein maturation involving reversible and irreversible post-translational modifications. Upon synthesis as a large precursor protein, HCF-1 undergoes extensive reversible glycosylation with β-N-acetylglucosamine giving rise to O-linked-β-N-acetylglucosamine (O-GlcNAc) modified serines and threonines. HCF-1 also undergoes irreversible site-specific proteolysis, which is important for one of HCF-1's major functions - the regulation of the cell-division cycle. HCF-1 O-GlcNAcylation and site-specific proteolysis are both catalyzed by a single enzyme with an unusual dual enzymatic activity, the O-GlcNAc transferase (OGT). HCF-1 is cleaved by OGT at any of six highly conserved 26 amino acid repeated sequences (HCF-1PRO repeats), but the mechanisms and the substrate requirements for OGT-mediated cleavage are not understood. In the present work, I characterized substrate requirements for OGT-mediated cleavage and O-GlcNAcylation of HCF-1. I identified key elements within the HCF-1PRO-repeat sequence that are important for proteolysis. Remarkably, an invariant single amino acid side-chain within the HCF-1PRO-repeat sequence displays particular OGT-binding properties and is essential for proteolysis. Additionally, I characterized substrate requirements for proteolysis outside of the HCF-1PRO repeat and identified a novel, highly O-GlcNAcylated OGT-binding sequence that enhances cleavage of the first HCF-1PRO repeat. These results link OGT association and its O-GlcNAcylation activities to HCF-1PRO-repeat proteolysis.

Intercomparação e calibração de medidores de atividade utilizados em serviços de medicina nuclear

OBJETIVO: O objetivo deste trabalho foi estabelecer um padrão de trabalho para intercomparação e calibração de medidores de atividade (calibradores de dose) utilizados na maioria dos serviços de medicina nuclear, para determinação da atividade dos radionuclídeos administrados aos pacientes nos exames específicos ou nos procedimentos terapêuticos. MATERIAIS E MÉTODOS: Foi utilizado um calibrador de dose comercial, um conjunto de fontes radioativas padrões, além de seringas, frascos e ampolas contendo soluções de radionuclídeos utilizados em medicina nuclear. RESULTADOS: O calibrador de dose comercial foi calibrado com soluções de radionuclídeos utilizados em medicina nuclear. Os testes simples do instrumento, tais como o teste de linearidade e da variação da resposta com o volume da fonte a uma concentração de atividade constante, foram descritos e realizados. CONCLUSÃO: O instrumento estudado pode agora ser utilizado como sistema de referência para intercomparação e calibração de outros instrumentos medidores de atividade, como um método de controle da qualidade de calibradores de dose utilizados em serviços de medicina nuclear.

Proposta de método de inspeção de radioproteção aplicada em instalações de medicina nuclear

O objetivo principal deste trabalho é implantar um método de inspeção imparcial e eficiente, visando à utilização segura e correta das radiações ionizantes no campo da medicina nuclear. Este método de inspeção aqui proposto foi aplicado em 113 serviços de medicina nuclear do país, obedecendo a uma freqüência de análise bienal (1996, 1998, 2000 e 2002). Foram estabelecidos 82 itens de radioproteção com pesos para cada item, baseados nos fatores de risco, de acordo com as normas da Comissão Nacional de Energia Nuclear (CNEN) e as recomendações da Agência Internacional de Energia Atômica. Na análise do serviço, cada item de não conformidade com as normas da CNEN gerou uma irregularidade de radioproteção, com seu peso associado. O somatório dos pesos deu a cada serviço uma pontuação final que o classificou dentro de três faixas de valores que determinaram uma tomada de decisão por parte do órgão regulador e fiscalizador: funcionamento sem restrição - menor que 100 pontos; funcionamento com restrição - igual ou maior que 100 e menor que 300 pontos; funcionamento suspenso - igual ou maior que 300 pontos. Para o caso de irregularidades reincidentes, criou-se um fator multiplicativo para a pontuação. A reincidência em qualquer item de radioproteção (irregularidade) teve seu peso multiplicado por 2n, onde n era o número de vezes em que o item encontrava-se irregular. O estabelecimento prévio de itens de radioproteção, com atribuição de pesos para cada item, procurou minimizar os valores subjetivos e pessoais presentes no julgamento e na avaliação técnica das instituições inspecionadas.

Characterization of the HIV protease inhibitor Nelfinavir cellular targets

The HIV protease inhibitors (HIV-PIs) are among the most potent antiviral drugs for the HIV infection. Treatment of patients with HIV-PIs has been linked with development of side effects including dyslipidemia, lipodystrophy syndrome and cardiovascular complications. Moreover, these drugs have shown anti-tumoral activity in non-infected patients but little is known about the involved molecular mechanism for these off-target effects. Here we propose that the HIV-PI Nelfinavir could block a cellular protease thus causing the observed phenotypes. We firstly focus our attention on a cellular protein, DDI2, showing sequence and structural conservation with the HIV protease. We applied cellular and in vitro approaches to produce a correctly folded recombinant protein in order to investigate the presence of a proteolytic activity. Despite the fact that we could identify two techniques that can be applied to produce a folded recombinant DDI2, no proteolytic activity has been identified in the present study. However, we could observe that decreasing the DDI2 levels recapitulated some phenotype observed in presence of HIV-PIs, including the phosphorylation of the protein translation regulators eIF2a and eEF2. As an alternative approach to identify cellular targets for HIV-PIs, we applied a proteomic screening called Slice-SILAC. We focused our attention on the defective maturation of Lamin A, a member of the nuclear lamina, induced by the block of the cellular protease Zmpste24. We demonstrated that Nelfinavir induced accumulation of Prelamin A and nuclear shape defects and in addition caused presence of cytosolic DNA, probably due to TREX1 downregulation. We showed that these phenotypes correlated with activation of the AIM2 inflammasome and IL-lß release. These findings suggest that DDI2 and Zmpste24 are direct or indirect cellular targets for the HIV-PIs and indicate a possible role for these proteins in promoting off-target effects and anti¬tumoral activity observed in HIV-PI treated patients. -- Les inhibiteurs de la protéase du VIH (IP-VIH) sont parmi les médicaments antiviraux les plus efficaces pour l'infection par le VIH. Le traitement des patients avec les IP-VIH cause des effets secondaires comprenant la dyslipidémie, le syndrome de lipodystrophie et les complications cardio-vasculaires. De plus, ces médicaments ont montré une activité anti-tumorale chez les patients non infectés, toutefois le mécanisme moléculaire impliqué dans ces effets hors-cible reste inconnu. Nous proposons que l'IP-VIH Nelfinavir puisse bloquer une protéase cellulaire provoquant les phénotypes observés. De ce fait, nous avons concentré notre attention sur une protéine cellulaire, DDI2, qui possède une séquence et une structure proche de celle de la protéase du VIH. Nous avons appliqué des approches cellulaire et in vitro pour produire une protéine recombinante correctement repliée afin d'étudier son activité protéolytique. Malgré le fait que nous avons pu identifier deux techniques qui peuvent être appliquées pour produire une protéine DDI2 recombinante correctement repliée, aucune activité protéolytique n'a été identifiée dans la présente étude. De plus, nous avons pu observer que la réduction de DDI2 récapitule les phénotypes observé avec le IP-VIH, y compris les phosphorylations de eIF2a et eEF2, impliquées dans la régulation de la traduction protéique. Une approche alternative, appelée Slice-SILAC, a été utilisée afin d'identifier de nouvelles cibles cellulaires du Nelfinavir. Nous avons concentré notre attention sur la maturation défectueuse de la Lamine A, un membre de la lamine nucléaire, induite par l'inhibition de la protéase cellulaire Zmpste24. Nous avons démontré que le Nelfinavir induit une accumulation de Prélamine A déformant la membrane nucléaire et la présence d'ADN cytosolique, probablement en raison de la régulation négative de TREX1. Nous avons montré que ces phénotypes causent l'activation de l'inflammasome AIM2 et la sécrétion d'IL-lß. Ces résultats suggèrent que DDI2 et Zmpste24 sont des cibles cellulaires pour les IP-VIH et indiquent un possible rôle pour ces protéines dans l'apparition d'effets secondaires ainsi que dans l'activité anti-tumorale observée chez les patients traités avec les IP-VIH.

Analysis of SKI-1/S1P prodomain provides insight on maturation and activation of SKI-1/S1P zymogen

SKI-l/SlP protease is a member of the proprotein convertase family, with several functions in cellular metabolism and homeostasis. It is responsible for the processing of several cellular substrates, including ATF6, SREBPs, and GlcNAc-1- phosphotranspherase. Furthermore, SKI-1/SlP is also responsible for maturation of arenavirus surface glycoprotein into GP1 and GP2 subunits. This processing is a strict requirement in order to achieve fully mature and fusion-competent virions. Furthermore, SKI-1/SlP itself is synthesized as an inactive zymogen, requiring sequential autocatalytic processing at several sites (B'/B and C) in its prodomain in order to mature and become fully active. Our project focused on the analysis of SKI- 1/S1P prodomain in the biogenesis of the active enzyme. In this context we have additionally developed and characterized a novel cell-based sensor for assessment of cellular activity of the enzyme, with a potential application in screening for novel SKI- 1/S1P inhibitors. In a first aim we have analysed the relevance of cleavage motifs found in the enzyme prodomain. Using molecular and biochemistry tools we have identified and characterized a novel C' maturation site. Furthermore, we found that SKI-1/SlP autoprocessing results in intermediates whose catalytic domain remains associated with prodomain fragments of different lengths. Contrasting with other proprotein convertases, incompletely matured intermediates of SKI-1/SlP exhibit full catalytic activity toward selected substrates. In a second aim, we turned our attention to the structural basis of SKI-1/SlP N- terminus assisted folding. Studying the folding and activity of prodomain-truncated forms of the enzyme we found that a minimal folding unit is contained in the AB region. Deletion of the BC sequence affected auto-maturation but not folding, and partial activity was retained. However, the BC region seemed required for complete and full activity. Phylogenetic analyses showed that the AB sequence is highly conserved, while the BC fragment is variable in sequence and length. Specifically, replacement of the human prodomain with that of Drosophila, resulted in a fully mature and active chimeric enzyme, suggesting an evolution process of SKI-1/SlP prodomain towards a more complex arrangement and steps of activation. Overall, the additional data we have produced might provide fundamental knowledge crucial for the development of novel SKI-1/SlP inhibitors while also providing new SKI- 1/S1P variants with potential use in crystallization purpose. -- SKI-l/SlP est une protéase membre de la famille des proprotéines convertases (PCs), avec plusieurs fonctions dans le métabolisme cellulaire et de l'homéostasie. Il est responsable pour la maturation de plusieurs substrats cellulaires, y compris ATF6, SREBPs et GlcNAc-1-phosphotranspherase. SKI-l/SlP est également responsable pour la maturation de la glycoprotéine des arénavirus, une exigence stricte pour atteindre des virions infectieuse. Synthétisé comme un zymogène inactif, SKI-l/SlP nécessite d'un traitement autocatalytique séquentiel sur plusieurs sites (B'/B et C) de son prodomaine afin de devenir pleinement active. Notre projet était axé sur l'analyse de SKI-l/SlP prodomaine dans la biogenèse de l'enzyme. Dans ce contexte, nous avons développé un nouveau senseur-cellulaire pour l'évaluation de l'activité de l'enzyme. Ce dernier pourrait avoir une potentielle application dans l'identification de nouveaux inhibiteurs de SKI-l/SlP. Premièrement, nous avons analysé la pertinence des motifs de clivage trouvés dans le prodomaine de l'enzyme. En utilisant des outils moléculaires et biochimiques, nous avons identifié et caractérisé un nouveau site de maturation (C'). Aussi, nous avons constaté que la maturation de SKI-l/SlP a des intermédiaires dont le domaine catalytique reste associé à des fragments du prodomaine de différentes longueurs. Contrastant avec d'autres PCs, les intermédiaires partiellement matures de SKI-1 / SIP présentent une activité catalytique complète envers des substrats spécifiques. Dans un deuxième but nous avons tourné notre attention sur la base structurelle du pliage de SKI-l/SlP assisté par son N-terminus: En étudiant l'activité et pliage des formes tronquées dans le prodomaine de l'enzyme, nous avons constaté qu'une unité de pliage minimale est contenue dans la région de l'AB. La suppression de la séquence d'auto-BC affecte la maturation mais pas le pliage, et l'activité partielle est maintenue. Cependant, la région BC semble nécessaire pour une activité complète. Les analyses phylogénétiques ont montré que la séquence AB est fortement conservée, tandis que le fragment de BC est variable en longueur et en séquence. En particulier, le remplacement du prodomaine humain avec celui de la drosophile, a donné lieu à une enzyme chimérique complètement mature et active. Suggérant un processus d'évolution du prodomaine vers un arrangement et des mesures d'activation plus complexe. Globalement, ces donnees supplémentaires augment les connaissances fondamentales cruciales pour le développement de nouveaux inhibiteurs de SKI-1/ SIP, tout en offrant de nouvelles variantes SKI-1 / SIP dans le but d'obtenir la structure cristallographique de l'enzyme.

Neutron skin of 208Pb, nuclear symmetry energy, and the parity radius experiment

A precise determination of the neutron skin thickness of a heavy nucleus sets a basic constraint on the nuclear symmetry energy (the neutron skin thickness is the difference of the neutron and proton rms radii of the nucleus). The parity radius experiment (PREX) may achieve it by electroweak parity-violating electron scattering (PVES) on 208Pb. We investigate PVES in nuclear mean field approach to allow the accurate extraction of the neutron skin thickness of 208Pb from the parity-violating asymmetry probed in the experiment. We demonstrate a high linear correlation between the parity-violating asymmetry and the neutron skin thickness in successful mean field forces as the best means to constrain the neutron skin of 208Pb from PREX, without assumptions on the neutron density shape. Continuation of the experiment with higher precision in the parity-violating asymmetry is motivated since the present method can support it to constrain the density slope of the nuclear symmetry energy to new accuracy.

Nuclear Factor I-C acts as a regulator of hepatocyte proliferation at the onset of liver regeneration.

BACKGROUND & AIMS: Knockout studies of the murine Nuclear Factor I-C (NFI-C) transcription factor revealed abnormal skin wound healing and growth of its appendages, suggesting a role in controlling cell proliferation in adult regenerative processes. Liver regeneration following partial hepatectomy (PH) is a well-established regenerative model whereby changes elicited in hepatocytes lead to their rapid and phased proliferation. Although NFI-C is highly expressed in the liver, no hepatic function was yet established for this transcription factor. This study aimed to determine whether NFI-C may play a role in hepatocyte proliferation and liver regeneration. METHODS: Liver regeneration and cell proliferation pathways following two-thirds PH were investigated in NFI-C knockout (ko) and wild-type (wt) mice. RESULTS: We show that the absence of NFI-C impaired hepatocyte proliferation because of plasminogen activator I (PAI-1) overexpression and the subsequent suppression of urokinase plasminogen activator (uPA) activity and hepatocyte growth factor (HGF) signalling, a potent hepatocyte mitogen. This indicated that NFI-C first acts to promote hepatocyte proliferation at the onset of liver regeneration in wt mice. The subsequent transient down regulation of NFI-C, as can be explained by a self-regulatory feedback loop with transforming growth factor beta 1 (TGF-ß1), may limit the number of hepatocytes entering the first wave of cell division and/or prevent late initiations of mitosis. CONCLUSION: NFI-C acts as a regulator of the phased hepatocyte proliferation during liver regeneration.