Transcriptional profiling of zebrafish identifies host factors controlling susceptibility to Shigella flexneri

Shigella flexneri is a human-adapted pathovar of Escherichia coli that can invade the intestinal epithelium, causing inflammation and bacillary dysentery. Although an important human pathogen, the host response to S. flexneri has not been fully described. Zebrafish larvae represent a valuable model to study human infections in vivo. Here we use a Shigella-zebrafish infection model to generate mRNA expression profiles of host response to Shigella infection at the whole animal level. Immune response-related processes dominate the signature of early Shigella infection (6 hours post-infection). Consistent with its clearance from the host, the signature of late Shigella infection (24 hours post-infection) is significantly changed, and only a small set of immune-related genes remain differentially expressed, including acod1 and gpr84. Using mutant lines generated by ENU, CRISPR mutagenesis and F0 Crispants, we show that acod1- and gpr84-deficient larvae are more susceptible to Shigella infection. Together, these results highlight the power of zebrafish to model infection by bacterial pathogens and reveal the mRNA expression of the early (acutely infected) and late (clearing) host response to Shigella infection

In vivo biomolecular imaging of zebrafish embryos using confocal Raman spectroscopy

Zebrafish embryos provide a unique opportunity to visualize complex biological processes, yet conventional imaging modalities are unable to access intricate biomolecular information without compromising the integrity of the embryos. Here, we report the use of confocal Raman spectroscopic imaging for the visualization and multivariate analysis of biomolecular information extracted from unlabeled zebrafish embryos. We outline broad applications of this method in: (i) visualizing the biomolecular distribution of whole embryos in three dimensions, (ii) resolving anatomical features at subcellular spatial resolution, (iii) biomolecular profiling and discrimination of wild type and ΔRD1 mutant Mycobacterium marinum strains in a zebrafish embryo model of tuberculosis and (iv) in vivo temporal monitoring of the wound response in living zebrafish embryos. Overall, this study demonstrates the application of confocal Raman spectroscopic imaging for the comparative bimolecular analysis of fully intact and living zebrafish embryos

Consolidation with ethyl silicate: how the amount of product alters the physical properties of the bricks and affects their durability

We evaluated the consolidating capacity of ethyl silicate in three types of bricks fired at 800, 950 and 1100 °C. We chose two concentrations of product, at 25% and 50%, diluting the product in white spirit to estimate whether greater dilution enables the product to penetrate deeper into the bricks, or whether a higher concentration leads to better consolidation of bricks. The application of ethyl silicate caused bricks porosity to decline and their compactness to increase. These changes were more accentuated as the concentration of the product increased. The pore size distribution not changed substantially except that there were fewer of the smallest pores. The color and the lightness of the pieces changed after application of the consolidant, albeit slightly. The durability of bricks improved as manifested by the results of the salt crystallization test. In general, the longest-lasting pieces were those treated with 25% ethyl silicate.Se ha evaluado la capacidad consolidante del silicato de etilo en tres tipos de ladrillos cocidos a 800, 950 y 1100 °C. Se eligieron dos concentraciones de producto, al 25% y 50%, diluyéndolo en white spirit para estimar si más dilución favorece una penetración más en profundidad del producto o si una mayor concentración produce una mejor consolidación de los ladrillos. El silicato de etilo ha causado una disminución de la porosidad y un aumento de la compacidad de los ladrillos, acentuándose estas modificaciones con mayor concentración de producto. La distribución porométrica no ha cambiado de forma sustancial, disminuyendo los poros más pequeños. Color y luminosidad de las piezas han modificado ligeramente tras la aplicación del consolidante. Los ladrillos consolidados han mejorado su durabilidad frente al envejecimiento acelerado producido por las sales. En general, las piezas más duraderas han resultado ser las tratadas con el 25% de silicato de etilo.This study was financially supported by Research Group RNM179 of the Junta de Andalucía and by Research Project MAT2016-75889-R

Septins restrict inflammation and protect zebrafish larvae from Shigella infection

Shigella flexneri, a Gram-negative enteroinvasive pathogen, causes inflammatory destruction of the human intestinal epithelium. Infection by S. flexneri has been well-studied in vitro and is a paradigm for bacterial interactions with the host immune system. Recent work has revealed that components of the cytoskeleton have important functions in innate immunity and inflammation control. Septins, highly conserved cytoskeletal proteins, have emerged as key players in innate immunity to bacterial infection, yet septin function in vivo is poorly understood. Here, we use S. flexneri infection of zebrafish (Danio rerio) larvae to study in vivo the role of septins in inflammation and infection control. We found that depletion of Sept15 or Sept7b, zebrafish orthologs of human SEPT7, significantly increased host susceptibility to bacterial infection. Live-cell imaging of Sept15-depleted larvae revealed increasing bacterial burdens and a failure of neutrophils to control infection. Strikingly, Sept15-depleted larvae present significantly increased activity of Caspase-1 and more cell death upon S. flexneri infection. Dampening of the inflammatory response with anakinra, an antagonist of interleukin-1 receptor (IL-1R), counteracts Sept15 deficiency in vivo by protecting zebrafish from hyper-inflammation and S. flexneri infection. These findings highlight a new role for septins in host defence against bacterial infection, and suggest that septin dysfunction may be an underlying factor in cases of hyper-inflammation

La cura dei materiali nel restauro dei monumenti

Attraverso la lettura di alcuni episodi, il volume discute le carenze dell'applicazione della' scienza' ai reali lavori di conservazione. In questo senso, viene rivolta particolare attenzione alla tecnologia della conservazione architettonica il cui compito, particolarmente difficile, non può non avere il supporto di un'attività di ricerca scientifica altamente specializzata