Traitements homéopathiques des différents troubles liés à la grossesse

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Strand-specific transcriptomes of Enterohemorrhagic Escherichia coli in response to interactions with ground beef microbiota: interactions between microorganisms in raw meat

France GenomiqueInternational audienceBackground: Enterohemorrhagic Escherichia coli (EHEC) are zoonotic agents associated with outbreaks worldwide. Growth of EHEC strains in ground beef could be inhibited by background microbiota that is present initially at levels greater than that of the pathogen E. coli. However, how the microbiota outcompetes the pathogenic bacteria is unknown. Our objective was to identify metabolic pathways of EHEC that were altered by natural microbiota in order to improve our understanding of the mechanisms controlling the growth and survival of EHECs in ground beef.Results: Based on 16S metagenomics analysis, we identified the microbial community structure in our beef samples which was an essential preliminary for subtractively analyzing the gene expression of the EHEC strains. Then, we applied strand-specific RNA-seq to investigate the effects of this microbiota on the global gene expression of EHEC O26(21765) and O157(EDL933) strains by comparison with their behavior in beef meat without microbiota. In strain O26(21765), the expression of genes connected with nitrate metabolism and nitrite detoxification, DNA repair, iron and nickel acquisition and carbohydrate metabolism, and numerous genes involved in amino acid metabolism were down-regulated. Further, the observed repression of ftsL and murF, involved respectively in building the cytokinetic ring apparatus and in synthesizing the cytoplasmic precursor of cell wall peptidoglycan, might help to explain the microbiota's inhibitory effect on EHECs. For strain O157(EDL933), the induced expression of the genes implicated in detoxification and the general stress response and the repressed expression of the peR gene, a gene negatively associated with the virulence phenotype, might be linked to the survival and virulence of O157:H7 in ground beef with microbiota.Conclusion: In the present study, we show how RNA-Seq coupled with a 16S metagenomics analysis can be used to identify the effects of a complex microbial community on relevant functions of an individual microbe within it. These findings add to our understanding of the behavior of EHECs in ground beef. By measuring transcriptional responses of EHEC, we could identify putative targets which may be useful to develop new strategies to limit their shedding in ground meat thus reducing the risk of human illnesses

No evidence for genetic differentiation in juvenile traits between Belgian and French populations of the invasive tree Robinia pseudoacacia

Background – The role of evolution in biological invasion studies is often overlooked. In order to evaluate the evolutionary mechanisms behind invasiveness, both quantitative and population genetics studies are underway on Robinia pseudoacacia L., one of the worst invasive tree species in Europe.Methods – A controlled experiment was set up using 2000 seeds from ten populations in Southern France and ten populations in Belgium. Seedlings were cultivated in two climatic chambers set at 18°C and 22°C. Early development life history traits (e.g. seedling phenology) and functional traits (e.g. growth rates) were monitored. Genotyping using SNP markers was used to evaluate the genetic differentiation among the populations and a QST – FST comparison was done in order to test for the role of selection.Results – Populations exhibited a strong plasticity to temperature for all measured traits, the warmer environment being generally more suitable, irrespective of their origin. No significant departure from neutral evolution was evidenced by the QST – FST comparisons, although we found a slightly significant differentiation at the molecular level. Conclusion – Plasticity for the functional and life history traits was evidenced but no genetic interaction suggesting no possible evolution of plasticity at those traits. Moreover, no support for genetic differentiation and local adaptation was found among studied populations within invasive range, raising two main questions: first, what is the role of selection on functional and life-history traits; and second, is the elapsed time since first introduction sufficient to allow evolution and local adaptation

Self-organization and dewetting kinetics in sub-10 nm diblock copolymer line/space lithography

International audienceIn this work, we investigated the self-assembly of a lamellar block copolymer (BCP) under different wetting conditions. We explored the influence of the chemical composition of under-layers and top-coats on the thin film stability, self-assembly kinetics and BCP domain orientation. Three different chemistries were chosen for these surface affinity modifiers and their composition was tuned in order to provide either neutral wetting (i.e. an out-of-plane lamellar structure), or affine wetting conditions (i.e. an in-plane lamellar structure) with respect to a sub-10 nm PS- b -PDMSB lamellar system. Using such controlled wetting configurations, the competition between the dewetting of the BCP layer and the self-organization kinetics was explored. We also evaluated the spreading parameter of the BCP films with respect to the configurations of surface-energy modifiers and demonstrated that BCP layers are intrinsically unstable to dewetting in a neutral configuration. Finally, the dewetting mechanisms were evaluated with respect to the different wetting configurations and we clearly observed that the rigidity of the top-coat is a key factor to delay BCP film instability

Defining definitions: a Delphi study to develop a core outcome set for conditions of severe maternal morbidity

Objective: Develop a core outcome set of international consensus definitions for severe maternal morbidities. Design: Electronic Delphi study. Setting: International. Population: Eight expert panels. Methods: All 13 high-income countries represented in the International Network of Obstetric Surveillance Systems (INOSS) nominated five experts per condition of morbidity, who submitted possible definitions. From these suggestions, a steering committee distilled critical components: eclampsia: 23, amniotic fluid embolism: 15, pregnancy-related hysterectomy: 11, severe primary postpartum haemorrhage: 19, uterine rupture: 20, abnormally invasive placentation: 12, spontaneous haemoperitoneum in pregnancy: 16, and cardiac arrest in pregnancy: 10. These components were assessed by the expert panel using a 5-point Likert scale, following which a framework for an encompassing definition was constructed. Possible definitions were evaluated in rounds until a rate of agreement of more than 70% was reached. Expert commentaries were used in each round to improve definitions. Main outcome measures: Definitions with a rate of agreement of more than 70%. Results: The invitation to participate in one or more of eight Delphi processes was accepted by 103 experts from 13 high-income countries. Consensus definitions were developed for all of the conditions. Conclusion: Consensus definitions for eight morbidity conditions were successfully developed using the Delphi process. These should be used in national registrations and international studies, and should be taken up by the Core Outcomes in Women's and Newborn Health initiative. Tweetable abstract: Consensus definitions for eight morbidity conditions were successfully developed using the Delphi process.</p