Proteome changes in muscles, ganglia, and gills in Corbicula fluminea clams exposed to crude oil: Relationship with behavioural disturbances

International audienc

Specific versus Non-Specific Immune Responses in an Invertebrate Species Evidenced by a Comparative de novo Sequencing Study

Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5′-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5′-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses

Performances of domiciliary ventilators compared by using a parametric procedure

WOS:000379882100001International audienceBackground: Noninvasive mechanical ventilation is sufficiently widely used to motivate bench studies for evaluating and comparing performances of the domiciliary ventilators. In most (if not in all) of the previous studies, ventilators were tested in a single (or a very few) conditions, chosen to avoid asynchrony events. Such a practice does not reflect how the ventilator is able to answer the demand from a large cohort of patients with their inherent inter-patient variability. We thus developed a new procedure according which each ventilator was tested with more than 1200 "simulated" patients. Methods: Three lung mechanics (obstructive, restrictive and normal) were simulated using a mechanical lung (ASL 5000) driven by a realistic muscular pressure. 420 different dynamics for each of these three lung mechanics were considered by varying the breathing frequency and the mouth occlusion pressure. For each of the nine ventilators tested, five different parameter settings were investigated. The results are synthesized in colored maps where each color represents the ventilator (in) ability to synchronize with a given muscular pressure dynamics. A synchronizability e is then computed for each map. Results: The lung model, the breathing frequency and the mouth occlusion pressure strongly affect the synchronizability of ventilators. The Vivo 50 (Breas) and the SomnoVENT autoST (Weinmann) are well synchronized with the restrictive model ((epsilon) over bar = 86 and 78 %, respectively), whereas the Elisee 150 (ResMed), the BiPAP A40 and the Trilogy 100 (Philips Respironics) better fit with an obstructive lung mechanics ((epsilon) over bar = 87, 86 and 86 %, respectively). Triggering and pressurization performances of the nine ventilators present heterogeneities due to their different settings and operating strategies. Conclusion: Performances of domiciliary ventilators strongly depend not only on the breathing dynamics but also on the ventilator strategy. One given ventilator may be more adequate than another one for a given patient

Judiciarisation de la fin de vie en réanimation : quand les proches demandent la poursuite des traitements

International audienc

Tension-time index of inspiratory muscles in COPD patients: role of airway obstruction

AbstractInspiratory muscle function has been shown to be related to general muscle weakness, weight loss, blood gas tensions, airway obstruction and hyperinflation. The aim of this study was to define (1) the factor that is the main determinant of the tension-time index of the inspiratory muscles (Ttmus), and which thus increases the risk of inspiratory muscle fatigue; and (2) whether a breathing strategy is adopted to avoid inspiratory muscle fatigue.Twenty-seven normal volunteers and 35 stable COPD outpatients (FEV1% predicted, range: 21–89%; and FRC/TLC, range: 49–77%) were studied. The Ttmus was determined as follows: Ttmus = Pi/Pimax · Ti/Ttot, where Pi is the mean inspiratory pressure calculated from the mouth occlusion pressure (P0·1), Pimax is the maximal inspiratory pressure, Ti is the inspiratory time, and Ttot is the total time of the breathing cycle.COPD patients showed significantly lower Pimax and higher P0·1, Pi, Pi/Pimax, and Ttmus than normal subjects. No patient had a Ttmus value higher than the inspiratory muscle fatigue threshold of 0·33. The FEV1 was significantly correlated with Ttmus and all its components in the patients. The FRC/TLC was also correlated with all components except Pi. Body weight was only correlated with Pimax. In a forward and backward stepwise regression analysis, FEV1 appeared to be the only significant factor explaining the variance of log (Pi/Pimax) and log (Ttmus), whereas FRC/TLC was the principal determinant of Pimax. In COPD patients, a non-linear relationship was found between Ti and P0·1. A negative linear relationship was found between Ti/Ttot and Pi/Pimax.In conclusion, although hyperinflation predominantly affected inspiratory muscle strength in a group of stable COPD patients with a wide range of severity, airway obstruction was the principal factor determining the magnitude of Ttmus. In addition, in order to remain below the inspiratory muscle fatigue threshold, as the severity of airway obstruction increased, patients adopted a breathing strategy characterized by decreased Ti/Ttot as inspiratory pressure demand increased

Cycling in critically ill patients in a neurological intensive care unit: A pilot study

ObjectiveTo determine the safety and feasibility of cycling in critically ill patients with brain or spinal cord injury.MethodsPatients with brain or spinal cord injury, either ventilated or not, who were admitted to the neurological intensive care unit (ICU) for at least one day were included. A multidisciplinary team with a physiotherapist, occupational therapist, nurses, intensive care doctors and a rehabilitation doctor screened the patients every morning for indications of early rehabilitation, specifically for indications of cycling with a cyclo-ergometer. This technique was used amongst other rehabilitation prescriptions in the neurological ICU such as mobilisations, neuromuscular-electrostimulation, ergonomic postures and transfer from bed to chair. The cyclo-ergometer used was MOTOmed and gave the possibility to do passive, motor-assisted, or active resistive training. The use of MOTOmed was assessed from a safety (contraindications and side effect profile) and feasibility (time constraints, availability, access to the machines and different modes) perspective.ResultsDuring 40 days, 49 passive cycling sessions and 21 active cycling sessions were completed. Two patients used the MOTOmed every day. Between one and seven patients, out of a total of 18 patients in the unit, were able to use the cyclo-ergometer on any one day. The physiotherapist needed ten minutes to prepare the patient. A nurse was needed to set up and adjust the external ventricular deviation if needed. Each session lasted 30minutes. The MOTOmed analysed the time using the passive or active mode, the force balance between the two legs and the calories used. The resistance and speed can be modified. The contraindications were: femoral venous or arterial lines, fragile skin, agitation or an acute medical problem. The relative contraindications were: bacterial isolation, external ventricular deviation. Only two side-effects were found: one desaturation and skin lesions.ConclusionLiterature on rehabilitation in neurological intensive care unit is poor. The delivery of cycling in critically ill patients with brain or spinal cord injury is both safe and feasible. Further research is required to confirm and evaluate the efficacy of cycling to prevent muscle weakness, spasticity and functional disorder in this population