The mechanisms of detoxification of As(III), dimethylarsinic acid (DMA) and As(V) in the microalga Chlorella vulgaris

The response of Chlorella vulgaris when challenged by As(III), As(V) and dimethylarsinic acid (DMA) was assessed through experiments on adsorption, efflux and speciation of arsenic (reduction, oxidation, methylation and chelation with glutathione/phytochelatin [GSH/PC]). Our study indicates that at high concentrations of phosphate (1.62 mM of HPO42−), upon exposure to As(V), cells are able to shift towards methylation of As(V) rather than PC formation. Treatment with As(V) caused a moderate decrease in intracellular pH and a strong increase in the concentration of free thiols (GSH). Passive surface adsorption was found to be negligible for living cells exposed to DMA and As(V). However, adsorption of As(III) was observed to be an active process in C. vulgaris, because it did not show saturation at any of the exposure periods. Chelation of As(III) with GS/PC and to a lesser extent hGS/hPC is a major detoxification mechanism employed by C. vulgaris cells when exposed to As(III). The increase of bound As-GS/PC complexes was found to be strongly related to an increase in concentration of As(III) in media. C. vulgaris cells did not produce any As-GS/PC complex when exposed to As(V). This may indicate that a reduction step is needed for As(V) complexation with GSH/PC. C. vulgaris cells formed DMASV-GS upon exposure to DMA independent of the exposure period. As(III) triggers the formation of arsenic complexes with PC and homophytochelatins (hPC) and their compartmentalisation to vacuoles. A conceptual model was devised to explain the mechanisms involving ABCC1/2 transport. The potential of C. vulgaris to bio-remediate arsenic from water appeared to be highly selective and effective without the potential hazard of reducing As(V) to As(III), which is more toxic to humans

Transfusion-transmitted infections

Although the risk of transfusion-transmitted infections today is lower than ever, the supply of safe blood products remains subject to contamination with known and yet to be identified human pathogens. Only continuous improvement and implementation of donor selection, sensitive screening tests and effective inactivation procedures can ensure the elimination, or at least reduction, of the risk of acquiring transfusion transmitted infections. In addition, ongoing education and up-to-date information regarding infectious agents that are potentially transmitted via blood components is necessary to promote the reporting of adverse events, an important component of transfusion transmitted disease surveillance. Thus, the collaboration of all parties involved in transfusion medicine, including national haemovigilance systems, is crucial for protecting a secure blood product supply from known and emerging blood-borne pathogens

Rethinking European integration history in light of capitalism: the case of the long 1970s

This introduction outlines the possibilities and perspectives of an intertwining between European integration history and the history of capitalism. Although debates on capitalism have been making a comeback since the 2008 crisis, to date the concept of capitalism remains almost completely avoided by historians of European integration. This introduction thus conceptualizes ‘capitalism’ as a useful analytical tool that should be used by historians of European integration and proposes three major approaches for them to do so: first, by bringing the question of social conflict, integral to the concept of capitalism, into European integration history; second, by better conceptualizing the link between European governance, Europeanization and the globalization of capitalism; and thirdly by investigating the economic, political and ideological models or doctrines that underlie European cooperation, integration, policies and institutions. Finally, the introduction addresses the question of the analytical benefits of an encounter between capitalism and European integration history, focusing on the case of the 1970s. This allows us to qualify the idea of a clear-cut rupture, and better highlight how the shift of these years resulted from a complex bargaining that took place in part at the European level

Rapid analysis for cadmium metallothionein complexes by HPLC using microparticulate stationary phases

International audienceDifferent columns with microparticulate (1.5 and 2 μm) stationary phases were investigated for the analysis of the polymorphism of mammalian metallothionein (MT) by reversed-phase HPLC. When a non-porous 1.5 μm stationary phase was used, the duration of the chromatographic run was reduced 10-fold (in comparison with the conventional 5 μm packing) without any loss in resolution. The method was applied to the analysis of MT-1 and MT-2 preparations from rabbit liver. © Springer-Verlag 1999