In Situ Fe and S isotope analyses in pyrite from the 3.2 Ga Mendon Formation (Barberton Greenstone Belt, South Africa): Evidence for early microbial iron reduction

International audienceOn the basis of phylogenetic studies and laboratory cultures, it has been proposed that the ability of microbes to metabolize iron has emerged prior to the Archaea/ Bacteria split. However, no unambiguous geochemical data supporting this claim have been put forward in rocks older than 2.7-2.5 giga years (Gyr). In the present work, we report in situ Fe and S isotope composition of pyrite from 3.28-to 3.26-Gyr-old cherts from the upper Mendon Formation, South Africa. We identified three populations of microscopic pyrites showing a wide range of Fe isotope compositions, which cluster around two δ 56 Fe values of −1.8‰ and +1‰. These three pyrite groups can also be distinguished based on the pyrite crystallinity and the S isotope mass-independent signatures. One pyrite group displays poorly crystallized pyrite minerals with positive Δ 33 S values > +3‰, while the other groups display more variable and closer to 0‰ Δ 33 S values with recrystallized pyrite rims. It is worth to note that all the pyrite groups display positive Δ 33 S values in the pyrite core and similar trace element compositions

Lung transplantation after allogeneic stem cell transplantation : a pan-European experience

Late-onset noninfectious pulmonary complications (LONIPCs) affect 6% of allogeneic stem cell transplantation (SCT) recipients within 5 years, conferring subsequent 5-year survival of 50%. Lung transplantation is rarely performed in this setting due to concomitant extrapulmonary morbidity, excessive immunosuppression and concerns about recurring malignancy being considered contraindications. This study assesses survival in highly selected patients undergoing lung transplantation for LONIPCs after SCT. SCT patients undergoing lung transplantation at 20 European centres between 1996 and 2014 were included. Clinical data pre- and post-lung transplantation were reviewed. Propensity score-matched controls were generated from the Eurotransplant and Scandiatransplant registries. Kaplan-Meier survival analysis and Cox proportional hazard regression models evaluating predictors of graft loss were performed. Graft survival at 1, 3 and 5 years of 84%, 72% and 67%, respectively, among the 105 SCT patients proved comparable to controls (p=0.75). Sepsis accounted for 15 out of 37 deaths (41%), with prior mechanical ventilation (HR 6.9, 95% CI 1.0-46.7; p Lung transplantation outcomes following SCT were comparable to other end-stage diseases. Lung transplantation should be considered feasible in selected candidates. No SCT-specific factors influencing outcome were identified within this carefully selected patient cohort.Peer reviewe

Liposomal antagomiR-155-5p restores anti-inflammatory macrophages and improves arthritis in preclinical models of rheumatoid arthritis

Objective: We previously reported an increased expression of microRNA‐155 (miR‐155) in the blood monocytes of patients with rheumatoid arthritis (RA) that could be responsible for impaired monocyte polarization to anti‐inflammatory M2‐like macrophages. In this study, we employed two preclinical models of RA, collagen‐induced arthritis and K/BxN serum transfer arthritis, to examine the therapeutic potential of antagomiR‐155‐5p entrapped within PEGylated (polyethylene glycol [PEG]) liposomes in resolution of arthritis and repolarization of monocytes towards the anti‐inflammatory M2 phenotype. Methods: AntagomiR‐155‐5p or antagomiR‐control were encapsulated in PEG liposomes of 100 nm in size and −10 mV in zeta potential with high antagomiR loading efficiency (above 80%). Mice were injected intravenously with 1.5 nmol/100 μL PEG liposomes containing antagomiR‐155‐5p or control after the induction of arthritis. Results: We demonstrated the biodistribution of fluorescently tagged PEG liposomes to inflamed joints one hour after the injection of fluorescently tagged PEG liposomes, as well as the liver's subsequent accumulation after 48 hours, indicative of hepatic clearance, in mice with arthritis. The injection of PEG liposomes containing antagomiR‐155‐5p decreased arthritis score and paw swelling compared with PEG liposomes containing antagomiR‐control or the systemic delivery of free antagomiR‐155‐5p. Moreover, treatment with PEG liposomes containing antagomiR‐155‐5p led to the restoration of bone marrow monocyte defects in anti‐inflammatory macrophage differentiation without any significant functional change in other immune cells, including splenic B and T cells. Conclusion: The injection of antagomiR‐155‐5p encapsulated in PEG liposomes allows the delivery of small RNA to monocytes and macrophages and reduces joint inflammation in murine models of RA, providing a promising strategy in human disease.imag

Community-Level Responses to Iron Availability in Open Ocean Plankton Ecosystems

Predicting responses of plankton to variations in essential nutrients is hampered by limited in situ measurements, a poor understanding of community composition, and the lack of reference gene catalogs for key taxa. Iron is a key driver of plankton dynamics and, therefore, of global biogeochemical cycles and climate. To assess the impact of iron availability on plankton communities, we explored the comprehensive bio-oceanographic and bio-omics data sets from Tara Oceans in the context of the iron products from two state-of-the-art global scale biogeochemical models. We obtained novel information about adaptation and acclimation toward iron in a range of phytoplankton, including picocyanobacteria and diatoms, and identified whole subcommunities covarying with iron. Many of the observed global patterns were recapitulated in the Marquesas archipelago, where frequent plankton blooms are believed to be caused by natural iron fertilization, although they are not captured in large-scale biogeochemical models. This work provides a proof of concept that integrative analyses, spanning from genes to ecosystems and viruses to zooplankton, can disentangle the complexity of plankton communities and can lead to more accurate formulations of resource bioavailability in biogeochemical models, thus improving our understanding of plankton resilience in a changing environment

Helios Is Associated with CD4 T Cells Differentiating to T Helper 2 and Follicular Helper T Cells In Vivo Independently of Foxp3 Expression

Although in vitro IL-4 directs CD4 T cells to produce T helper 2 (Th2)-cytokines, these cytokines can be induced in vivo in the absence of IL-4-signalling. Thus, mechanism(s), different from the in vitro pathway for Th2-induction, contribute to in vivo Th2-differentiation. The pathway for in vivo IL-4-independent Th2-differentiation has yet to be characterized. - upregulate Th1 features - T-bet and IFN-γ - but not Helios. In addition, CD4 T cells induced to produce Th2 cytokines in vitro do not express Helios. The kinetics of Helios mRNA and protein induction mirrors that of GATA-3. The induction of IL-4, IL-13 and CXCR5 by alumOVA requires NF-κB1 and this is also needed for Helios upregulation. Importantly, Helios is induced in Th2 and TFh cells without parallel upregulation of Foxp3. These findings suggested a key role for Helios in Th2 and TFh development in response to alum-protein vaccines. We tested this possibility using Helios-deficient OTII cells and found this deficiency had no discernable impact on Th2 and TFh differentiation in response to alumOVA.Helios is selectively upregulated in CD4 T cells during Th2 and TFh responses to alum-protein vaccines in vivo, but the functional significance of this upregulation remains uncertain

Mesoscale modeling of the Shock-to-Detonation Transition of pressed-HMX based on a surface regression model

International audienceShock-to-Detonation Transition (SDT) of heterogeneous high explosives results from processes occurring at the microstructural level. Thus, mesoscale modeling is expected to allow a better comprehension of the SDT. Recent experimental evidence suggested that hotspots mainly developed on the surface of the energetic crystals, which are then consumed by the propagation of a deflagration front. In the present study, mesoscale simulations of the SDT of pressed HMX were performed. The reactive model employed consisted of igniting the surface of the crystals after the shock passage, and reconstructing the burn front propagation, using a modified Youngs’ method. In this reactive model, the velocity of the deflagration front was modeled by a pressure-dependent law, as suggested by the literature. The simulations showed that the Single Curve Initiation principle remained valid. The parameter deflagration velocity times the surface to volume ratio was found to enable the equivalence between microstructures. This approach provides a new framework to study the SDT of heterogeneous explosives, by considering how the combustion of energetic crystals participate to the shock acceleration and transition into a detonation. This paper serves as a proof of concept, applied to the pressed HMX

Regulation of cortical stability by RhoGEF3 in mitotic Sensory Organ Precursor cells in Drosophila

International audienceIn epithelia, mitotic cells round up and push against their neighbors to divide. Mitotic rounding results from increased assembly of F-actin and cortical recruitment of Myosin II, leading to increased cortical stability. Whether this process is developmentally regulated is not well known. Here, we examined the regulation of cortical stability in Sensory Organ Precursor cells (SOPs) in the Drosophila pupal notum. SOPs differed in apical shape and actomyosin dynamics from their epidermal neighbors prior to division, and appeared to have a more rigid cortex at mitosis. We identified RhoGEF3 as an actin regulator expressed at higher levels in SOPs, and showed that RhoGEF3 had in vitro GTPase Exchange Factor (GEF) activity for Cdc42. Additionally, RhoGEF3 genetically interacted with both Cdc42 and Rac1 when overexpressed in the fly eye. Using a null RhoGEF3 mutation generated by CRISPR-mediated homologous recombination, we showed using live imaging that the RhoGEF3 gene, despite being dispensable for normal development, contributed to cortical stability in dividing SOPs. We therefore suggest that cortical stability is developmentally regulated in dividing SOPs of the fly notum

Practical recommendations on room sizes for hospitalised newborn infants and their families based on a systematic review of the literature.

International audienc

0548: Heart failure with preserved ejection fraction: an echocardiographic based approach to assess the prognosis. A report from the large prospective KaRen study

BackgroundKaRen is a prospective study designed to characterize and follow a cohort of heart failure with preserved ejection fraction (HFpEF) patients. HFpEF remains a challenging syndrome. Patients have clinical signs linked to congestion but left ventricular (LV) EF is > 45%. We sought to test the relevance of echocardiographic parameters as predictors of death or hospitalization for cardiovascular reasons.Methods and resultsFollowing an acute HF accompanied with NT-proBNP >300pg/ml (BNP >100pg/ml) and LVEF >45%, patients were included (n=349). The patients were reassessed by echo-Doppler after 4-8 weeks. Echocardiographies were standardized and the analysis centralized. LVEF was 62±13%, LV global longitudinal strain: – 15±3%, E/e’:12.9±6.2, Left atrial volume: 49±18ml/m², Tricuspid regurgitation: 2.9±0.9m/s. Two parameters are correlated with the survival without any death or hospitalisation for cardiovascular reason and could be combined in a score: 2 x (E / e’) + RA area. This score has a theoretical range between 0 and 14. Based on tertiles of the score, censoring (frequencies of death or hospitalization for heart failure) were 48 (37.80), 67 (57.76) and 85 (75.22) in the 1st tertile – poor prognosis (N = 127), the 2nd tertile – intermediate (N = 116) and the 3rd tertile – good prognosis (N = 113), respectively.ConclusionCombination of simple echocardiographic criteria (right atrial area and E/e’ ratio) was found relevant to predict the long term prognosis in a large cohort of patients diagnosed for heart failure with preserved ejection fraction