Exposure of the marine deposit feeder Hydrobia ulvae to sediment associated LAS

7 páginas, 4 figuras, 4 tablas.Linear Alkylbenzene Sulfonates (LAS) effects (mortality, egestion rate, behaviour) on the marine deposit feeder Hydrobia ulvae were assessed in whole-sediment and water-only systems. The results were combined with a bioenergetic-based kinetic model of exposure pathways to account for the observed toxicity. The 10-d LC50 value based on the freely dissolved fraction was 9.3 times lower in spiked sediment (0.152 ± 0.001 (95% CI) mg/L) than in water-only (1.390 ± 0.020 (95% CI) mg/L). Consequently, the actual 10-d LC50 value (208 mg/kg) was overestimated by the Equilibrium Partitioning calculation (1629 mg/kg). This suggests that the sediment associated LAS fraction was bioavailable to the snails. It could also be due to modifications in physiological parameters in absence of sediment, the organism natural substrate.This research was supported by the European Commission through the FP6 program (EST Marie Curie Fellowship) and it was performed in the framework of the RISICO project (MEST-CT-2004-505182). We also acknowledge the financial support of ERASM, ECOSOL and PETRESA.Peer reviewe

Supplementary Material for: Accumulation of carbamylation-derived products in aneurysmal aorta

Introduction: Carbamylation is a nonenzymatic post-translational modification of proteins characterized by the binding of isocyanic acid to amino groups of proteins, which leads to the alteration of their properties. An increase of serum carbamylation-derived products, including homocitrulline (HCit), has been shown to be associated with the development of cardiovascular diseases. Methods: HCit was quantified by LC-MS/MS within extracts of aneurysmal and control human aortas. A mouse model of aortic aneurysm (ApoE-/- mice perfused with angiotensin II and fed with sodium cyanate) was used to evaluate the role of carbamylation in aneurysm development. Results: HCit quantification showed a greater heterogeneity of values in aneurysmal aortas in comparison with control ones. At the maximum diameter of dilation, HCit values were significantly higher (+94%, p<0.05) compared with less dilated areas. No differences was observed according to aneurysm size or when comparing ruptured and unruptured aneurysms. No significant effect of carbamylation on aneurysm development was observed using the animal model. Conclusions: These results evidenced the accumulation of HCit within aneurysmal aortas but do not allow to conclude about the exact participation of protein carbamylation in the development of human abdominal aortic aneurysms

A Murine ESC-like State Facilitates Transgenesis and Homologous Recombination in Human Pluripotent Stem Cells

Murine pluripotent stem cells can exist in two functionally distinct states, LIF-dependent embryonic stem cells (ESCs) and bFGF-dependent epiblast stem cells (EpiSCs). However, human pluripotent cells so far seemed to assume only an epiblast-like state. Here we demonstrate that human iPSC reprogramming in the presence of LIF yields human stem cells that display morphological, molecular, and functional properties of murine ESCs. We termed these hLR5 iPSCs because they require the expression of five ectopic reprogramming factors, Oct4, Sox2, Klf4, cMyc, and Nanog, to maintain this more naive state. The cells are "metastable" and upon ectopic factor withdrawal they revert to standard human iPSCs. Finally, we demonstrate that the hLR5 state facilitates gene targeting, and as such provides a powerful tool for the generation of recombinant human pluripotent stem cell lines