Technical aspects of an impact acceleration traumatic brain injury rat model with potential suitability for both microdialysis and PtiO2 monitoring

This report describes technical adaptations of a traumatic brain injury (TBI) model-largely inspired by Marmarou-in order to monitor microdialysis data and PtiO2 (brain tissue oxygen) before, during and after injury. We particularly focalize on our model requirements which allows us to re-create some drastic pathological characteristics experienced by severely head-injured patients: impact on a closed skull, no ventilation immediately after impact, presence of diffuse axonal injuries and secondary brain insults from systemic origin...We notably give priority to minimize anaesthesia duration in order to tend to banish any neuroprotection. Our new model will henceforth allow a better understanding of neurochemical and biochemical alterations resulting from traumatic brain injury, using microdialysis and PtiO2 techniques already monitored in our Intensive Care Unit. Studies on efficiency and therapeutic window of neuroprotective pharmacological molecules are now conceivable to ameliorate severe head-injury treatment

Changements de pratiques dans les produits cosmétiques des lanceurs d'alerte aux impacts sur le milieu aquatique

International audiencePrésentation du projet Cosmet'ea

Contribution of Fluorescence Techniques in Determining the Efficiency of the Non-thermal Plasma Treatment

We have recently developed a non-thermal plasma (NTP) equipment intended to sterilize fragile medical devices and maintain the sterile state of items downstream the treatment. With traditional counts on agar plate a six log reduction of Staphylococcus aureus viability was obtained within 120 min of O2, Ar, or N2 NTP treatments. However to determine the best NTP process, we studied the different physiological states of S. aureus by flow cytometry (FC) and confocal laser scanning microscopy (CLSM) focusing on the esterasic activity and membrane integrity of the bacteria. Two fluorochromes, 5-(and-6)-carboxy-2′,7′-dichlorofluorescein diacetate and propidium iodide were used in order to distinguish three sub-populations: metabolically active, permeabilized, and damaged bacteria that can be in the viable but nonculturable state. FC and CLSM highlight that O2 and Ar NTP treatments were the most attractive processes. Indeed, a 5 min of Ar NTP generated a high destruction of the structure of bacteria and a 120 min of O2 NTP treatment led to the higher decrease of the total damaged bacteria population. SEM observations showed that in presence of clusters, bacteria of upper layers are easily altered compared to bacteria in the deeper layers. In conclusion, the plate counting method is not sufficient by itself to determine the best NTP treatment. FC and CLSM represent attractive indicator techniques to select the most efficient gas NTP treatment generating the lowest proportion of viable bacteria and the most debris

Central mechanisms of itch: A systematic literature review and meta-analysis

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ATELIER : TRAVAILLER DES COMPETENCES TRANSVERSALES EN INFORMATION : UNE NECESSITE AVEC LES ETUDIANTS D'AUJOURD'HUI

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Simulation Method Linking Dense Microalgal Culture Spectral Properties in the 400–750 nm Range to the Physiology of the Cells

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIREInternational audienceThis work describes a method to model the optical properties over the (400-750 nm) spectral range of a dense microalgal culture using the chemical and physical properties of the algal cells. The method was based on a specific program called AlgaSim coupled with the adding-doubling method: at the individual cell scale, AlgaSim simulates the spectral properties of one model, three-layer spherical algal cell from its size and chemical composition. As a second step, the adding-doubling method makes it possible to retrieve the total transmittance of the algal medium from the optical properties of the individual algal cells. The method was tested by comparing the simulated total transmittance spectra for dense marine microalgal cultures of Isochrysis galbana (small flagellates) and Phaeodactylum tricornutum (diatoms) to spectra measured using an experimental spectrophotometric setup. Our study revealed that the total transmittance spectra simulated for the quasi-spherical cells of Isochrysis galbana were in good agreement with the measured spectra over the whole spectral range. For Phaeodactylum tricornutum, large differences between simulated and measured spectra were observed over the blue part of the transmittance spectra, probably due to non-spherical shape of the algal cells. Prediction of the algal cell density, mean size and pigment composition from the total transmittance spectra measured on algal samples was also investigated using the reversal of the method. Mean cell size was successfully predicted for both species. The cell density was also successfully predicted for spherical Isochrysis galbana, with a relative error below 7%, but not for elongated Phaeodactylum tricornutum with a relative error up to 26%. The pigments total quantity and composition, the carotenoids:chlorophyll ratio in particular, were also successfully predicted for Isochrysis galbana with a relative error below 8%. However, the pigment predictions and measurements for Phaeodactylum tricornutum showed large discrepancies, with a relative error up to 88%. These results give strong support for the development of a promising tool providing rapid and accurate estimations of biomass and physiological status of a dense microalgal culture based on only light transmittance properties

Inflammatory Bowel Diseases and School Absenteeism

International audienceObjectives - Inflammatory bowel diseases (IBDs) are chronic diseases which negatively affect the schooling of children. The aim is to analyze school absenteeism and its causes in children followed for IBD. Methods - A prospective multicenter study of IBD patients aged from 5 to 18 years old, from September 2016 to June 2017. Data on absenteeism and its causes were collected via a monthly questionnaire completed by patients or their family by mail. The results were compared with existing data supplied by the school authorities (497 students without IBD divided by class). Results - A total of 106 patients (62 boys), median age of 14 (5-18), were included. The global response rate was 83.1%. The patients with IBD were absent an average of 4.8% ± 5.5% of school days during the school year, against 3.2% ± 1.6% for non IBD group (P = 0.034). Digestive disorders accounted for 34% of the causes of absenteeism. Approximately 27% of the absences were due to scheduled events (hospitalizations, endoscopy, or consultations). By excluding the absences for scheduled care, the rate of school absenteeism of patients with IBD is significantly lower than that of non-IBD group. Conclusion - Children with IBD are more frequently absent from school than non-IBD group. The main cause of school absenteeism appears to be associated with the disease itself. The share of scheduled absenteeism is quite large. The organization and scheduling of the patients' care path must be a priority to maximally limit the negative impact of their disease on the patients' schooling

The histone demethylase KDM3 prevents auto-immune piRNAs production in <i>Drosophila</i>

SUMMARYIn animals, genome integrity of the germ line is protected from transposable element (TE) activity by small, non-coding, dedicated RNAs acting as an immune system against TEs, and called PIWI-interacting RNAs (piRNAs) 1,2. In Drosophila, the production of piRNAs is initiated from heterochromatic loci containing remnants of TEs and enriched in histone H3 trimethylated on lysine 9 (H3K9me3) 3–5. These loci, called piRNA clusters, constitute a memory of past TE invasions. Little is known about how piRNA clusters are genetically defined. Using a genetic screen combined with a bimodal epigenetic state piRNA cluster (BX2), we identified the splicing factor Half pint (Hfp) and the histone demethylase KDM3 as being able to prevent BX2 piRNA production. Furthermore, we showed that Hfp is needed to splice Kdm3 transcripts. Germline expression of Kdm3 coding sequence (splicing-independent) rescued the hfp germline knock-down (GLKD) effect demonstrating that Kdm3 is sufficient to prevent BX2 piRNA production. Our data revealed that in the absence of Kdm3, dozens of gene-containing regions become bona fide germinal dual strand piRNA clusters. Indeed, they produce piRNAs originating from both DNA strands, become transcribed in a Moonshiner-dependent manner and enriched in di-and tri-methylation of lysine 9 of histone H3 (H3K9me2/3) and in Rhino, an HP1-like protein. Eggs laid by Kdm3 GLKD females do not hatch and show developmental defects phenocopying loss of function of genes included into the new piRNA clusters, suggesting an inheritance of functional ovarian “auto-immune” piRNAs. Our results demonstrate that some gene-containing regions are actively prevented for piRNA production by proteins that counteract piRNA cluster emergence. Hence, a non-piRNA-producing state is therefore not a “by default” state but rather a cellular lock that is actively controlled for some genomic loci.KEY FACTSHfp regulates the expression of Kdm3 via its splicingKdm3 prevents genomic regions containing coding genes from becoming piRNA clustersEmbryos from Kdm3 mutant females show developmental phenotypes suggesting that auto-immune piRNAs are functional and alter the expression of genes embedded in newly established piRNA clusters</jats:sec

The histone demethylase Kdm3 prevents auto-immune piRNAs production in Drosophila

Genome integrity of the animal germline is protected from transposable element activity by PIWI-interacting RNAs (piRNAs). While piRNA biogenesis is intensively explored, little is known about the genetical determination of piRNA clusters, the genomic sources of piRNAs. Using a bimodal epigenetic state piRNA cluster ( BX2 ), we identified the histone demethylase Kdm3 as being able to prevent a cryptic piRNA production. In the absence of Kdm3, dozens of coding gene-containing regions become genuine germline dual-strand piRNA clusters. Eggs laid by Kdm3 mutant females show developmental defects phenocopying loss of function of genes embedded into the additional piRNA clusters, suggesting an inheritance of functional ovarian “auto-immune” piRNAs. Antagonizing piRNA cluster determination through chromatin modifications appears crucial to prevent auto-immune genic piRNAs production