Leukotrienes (LT) are biologically active lipid mediators known to be involved in allergic inflammation. Leukotrienes have been shown to mediate diverse features of allergic conditions including ...inflammatory cell chemotaxis/activation and smooth muscle contraction. Cysteinyl leukotrienes (LTC₄, LTD₄ and, LTE₄) and the dihydroxy leukotriene LTB₄ are generated by a series of enzymes/proteins constituting the LT synthetic pathway or 5-lipoxygenase (5-LO) pathway. Their function is mediated by interacting with multiple receptors. Leukotriene receptor antagonists (LTRA) and LT synthesis inhibitors (LTSI) have shown clinical efficacy in asthma and more recently in allergic rhinitis. Despite growing knowledge of leukotriene biology, the molecular regulation of these inflammatory mediators remains to be fully understood. Genes encoding enzymes of the 5-LO pathway (i.e. ALOX5, LTC4S and LTA4H) and encoding for LT receptors (CYSLTR1/2 and LTB4R1/2) provide excellent candidates for disease susceptibility and severity; however, their role remains unclear. Preliminary data also suggest that 5-LO pathway/receptor gene polymorphism can predict patient responses to LTSI and LTRA; however, the exact mechanisms require elucidation. The aim of this review was to summarize the recent advances in the knowledge of these important mediators, focusing on genetic and pharmacogenetic aspects in the context of allergic phenotypes.
In the last years, applications for silver nanoparticles (Ag NPs) continue to increase together with the concerns about their potential input and hazards in aquatic ecosystems, where microalgae are ...key organisms. The aim of the present study was to assess the relative sensitivity of three marine microalgae species with differences in cell wall composition/structure exposed to Poly N-vinyl-2-pirrolidone/Polyethyleneimine (PVP/PEI) coated 5nm Ag NPs and uncoated 47nm Ag NP. As limited attention has been paid to the role of coating agents in NP toxicity, the effect of PVP/PEI alone was also evaluated. After 72h in artificial seawater, 47nm Ag NPs formed around 1400nm size aggregates while PVP/PEI coated 5nm Ag NPs reached around 90nm. Ag+ release in seawater was around 3% for 47nm Ag NPs and 30% for PVP/PEI coated 5nm Ag NPs. PVP/PEI coated 5nm Ag NP aggregates entrapped the algal cells in a network of heteroaggregates, while uncoated 47nm Ag NPs interacted to a lesser extent with algae. The concentration of PVP/PEI coated 5nm Ag NPs that exerted the median effect (EC50) on algae growth pointed out differences in algae sensitivity: T. suecica was about 10 times more sensitive than I. galbana and P. tricornutum. Further, the coating agent alone was as toxic to algae as PVP/PEI coated 5nm Ag NPs, suggesting that presence of the coating agent was the main driver of toxicity of coated NPs. Uncoated 47nm Ag NPs instead, showed similar toxicity towards algae although P. tricornutum was slightly less sensitive than T. suecica and I. galbana, which agrees with the presence of a resistant silicified cell wall in the diatom. The present work demonstrates differences in sensitivity of three marine microalgae, possibly related to their cell surface and size characteristics.
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•Effects of coated, uncoated Ag NPs and coating agent on microalgae were evaluated.•Coated 5 nm Ag NPs produced aggregates of smaller size and released 10 times more Ag ions than uncoated 47 nm Ag NPs.•Coated 5 nm Ag NPs were more toxic than uncoated 47 nm Ag NPs.•The coating agent alone was as toxic as coated 5 nm Ag NPs.•Tetraselmis suecica was about 10 times more sensitive than Isochrysis galbana and Phaeodactylum tricornutum.
Inflammatory gene expression in airway smooth muscle may be influenced by its inflammatory milieu. We analysed the gene expression profile of airway smooth muscle cells cultured from human airways ...exposed to a pro-inflammatory cytokine, interleukin-1β, a T helper-2 cytokine, interleukin-13, and to a growth factor, transforming growth factor (TGF)β1 (10 ng/ml each) after 4 and 24 h using the Affymetrix GeneChip 95A array which detects ∼12,500 genes and expression sequence tags (ESTs). Airway smooth muscle cells were responsive to each cytokine with distinctive patterns of gene expression for cytokines, chemokines, adhesion and signalling proteins, and transcription factors. Interleukin-1β induced the highest number of genes such as cytokines/chemokines including interleukin-8, growth-related oncogene (GRO)-α, -β and -γ, epithelial neutrophil activating protein (ENA)-78, monocyte chemotactic protein (MCP)-1, -2 and -3 and eotaxin. Using quantitative real-time reverse transcription-polymerase chain reaction, the expression of GRO-α, -β and -γ, interleukin-8 and eotaxin by interleukin-1β was confirmed, with good correlation with microarray data. Transforming growth factor (TGF)β1 induced other growth factors such as connective tissue growth factor (CTGF), vascular endothelial growth factor (VEGF), insulin growth factor (IGF) and many structural and extracellular matrix proteins. Interleukin-13 was the weakest inducer, with stimulation of eotaxin and genes of unknown function. While many genes were co-regulated at 4 and 24 h, there were also differences in expression patterns. Interleukin-1β induces a predominantly pro-inflammatory profile while TGFβ1 can be linked to proliferative and matrix changes. The rich profile of mediators, growth factors and signalling molecules released from airway smooth muscle depends on the inflammatory milieu.
La division sociale de l’espace est méconnue pour les niveaux intermédiaires de la hiérarchie urbaine aux États-Unis, auxquels sont souvent appliqués les principes des plus grandes villes, et alors ...qu’ils sont souvent décrits comme des échelons idéaux. Cet article ouvre des pistes de recherche sur les dynamiques socio-spatiales dans les villes intermédiaires américaines à partir de la notion de discontinuité, notion privilégiée en raison de la moindre taille des villes et de son acception multidimensionnelle. Les enjeux sont doubles : définir une catégorie spécifique de la hiérarchie urbaine ; comprendre les logiques de la séparation sociale en leur sein et les discontinuités.
La division sociale de l’espace est méconnue pour les niveaux intermédiaires de la hiérarchie urbaine aux États-Unis, auxquels sont souvent appliqués les principes des plus grandes villes, et alors ...qu’ils sont souvent décrits comme des échelons idéaux. Cet article ouvre des pistes de recherche sur les dynamiques socio-spatiales dans les villes intermédiaires américaines à partir de la notion de discontinuité, notion privilégiée en raison de la moindre taille des villes et de son acception multidimensionnelle. Les enjeux sont doubles : définir une catégorie spécifique de la hiérarchie urbaine ; comprendre les logiques de la séparation sociale en leur sein et les discontinuités.
ABSTRACT IN FRENCH: La division sociale de l'espace est méconnue pour les niveaux intermédiairies de la hiérarchie urbaine aux États-Unis, auxquels sont souvent appliqués les principes des plus ...grandes villes, et alors qu'ils sont souvent décrits comme des échelons idéaux. Cet article ouvre des pistes de recherche sur les dynamiques socio-spatiales dans les villes intermédiaires américaines à partir de la notion de discontinuité, notion privilégiée en raison de la moindre taille des villes et de son acception multidimensionnelle. Les enjeux sont doubles: définir une catégorie spécifique de la hiérarchie urbaine; comprendre les logiques de la séparation sociale en leur sein et les discontinuités. // ABSTRACT IN ENGLISH: The social division of space is unclear for the intermediate levels of urban hierarchy in the US. Principles created for larger cities are often applied to these mid-size agglomerations, despite the fact that the latter are often described as ideal. This article explores different issues of the social and spatial dynamics in mid-size American cities using the notion of discontinuity. The challenges are twofold: to define a specific category for urban hierarchy and to understand the logic of their inner social separation and discontinuities, a key notion due to the smaller size of the cities and to its multidimensional definition. Reprinted by permission of Éditions BELIN
Cet article a pour objectif de présenter la méthodologie de diagnostic qualité et d’apurement des données, expérimentée à partir d’une enquête de mobilité individuelle (programme Mobi’Kids). Une ...première partie revient sur la démarche suivie et pointe l’enjeu de l’évaluation de la qualité de données hétérogènes issues d’une méthode mixte et longitudinale de collecte (suivis GPS, enquêtes, observations). Une deuxième partie établit un diagnostic qualité selon l’origine (GPS, algorithme, enquête) et la nature des erreurs (complétude, précision, cohérence). Ces typologies permettent, dans une troisième partie, de définir d’une chaîne de traitements reproductible visant à améliorer la qualité interne et externe des données.
This paper aims at proposing a data quality diagnosis and cleansing data methodology experimented on an individual mobility survey (Mobi’Kids program). The first section presents the theoretical approach to highlight the issue of a data quality diagnosis applied to heterogeneous data collected from mixed methods (GPS tracks, surveys, observations). Secondly, two typologies of major errors are discussed according to their origin (GPS, algorithm, survey) and their nature (completeness, accuracy, consistency). A processing chain is thirdly defined to improve both internal and external data quality in order to the perspective of a replicable methodology.
Née au début des années 1990, l’association Feuilles de Géo, nommée familièrement Feuilles de choux, était une coopérative de partage de cours à destination des enseignants en géographie dans le ...supérieur. Aujourd’hui méconnue des plus jeunes générations d’enseignants-chercheurs, le projet était inédit à l’époque : parler pédagogie en géographie à l’Université, quand« montrer ce qu’on faisait en cours, c’était quasiment obscène » (CG).Selon les fondateurs, la revue eut pourtant un certain suc...
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