e-Pilly TROP Maladies infectieuses tropicales

L’e-Pilly TROP est un ouvrage d’infectiologie tropicale destiné aux médecins et aux étudiants en médecine des pays francophones du Sud. La prise en compte des différents niveaux de la pyramide sanitaire dans ces pays le rend aussi accessible aux infirmiers des centres de santé communautaires urbains et des structures de santé intermédiaires des zones rurales. Par définition, les Pays En Développement accroissant progressivement leurs capacités de diagnostic biologique et de traitement, les outils de prise en charge correspondent aux moyens des niveaux périphériques comme à ceux des niveaux hospitaliers de référence

Identification and Evolution of Drug Efflux Pump in Clinical Enterobacter aerogenes Strains Isolated in 1995 and 2003

BACKGROUND: The high mortality impact of infectious diseases will increase due to accelerated evolution of antibiotic resistance in important human pathogens. Development of antibiotic resistance is a evolutionary process inducing the erosion of the effectiveness of our arsenal of antibiotics. Resistance is not necessarily limited to a single class of antibacterial agents but may affect many unrelated compounds; this is termed 'multidrug resistance' (MDR). The major mechanism of MDR is the active expulsion of drugs by bacterial pumps; the treatment of gram negative bacterial infections is compromised due to resistance mechanisms including the expression of efflux pumps that actively expel various usual antibiotics (beta-lactams, quinolones, ...). METHODOLOGY/PRINCIPAL FINDINGS: Enterobacter aerogenes has emerged among Enterobacteriaceae associated hospital infections during the last twenty years due to its faculty of adaptation to antibiotic stresses. Clinical isolates of E. aerogenes belonging to two strain collections isolated in 1995 and 2003 respectively, were screened to assess the involvement of efflux pumps in antibiotic resistance. Drug susceptibility assays were performed on all bacterial isolates and an efflux pump inhibitor (PAbetaN) previously characterized allowed to decipher the role of efflux in the resistance. Accumulation of labelled chloramphenicol was monitored in the presence of an energy poison to determine the involvement of active efflux on the antibiotic intracellular concentrations. The presence of the PAbetaN-susceptible efflux system was also identified in resistant E. aerogenes strains. CONCLUSIONS/SIGNIFICANCE: For the first time a noticeable increase in clinical isolates containing an efflux mechanism susceptible to pump inhibitor is report within an 8 year period. After the emergence of extended spectrum beta-lactamases in E. aerogenes and the recent characterisation of porin mutations in clinical isolates, this study describing an increase in inhibitor-susceptible efflux throws light on a new step in the evolution of mechanism in E. aerogenes

Aliasing affects ActiLife software raw accelerometry to count conversion from different sampling frequencies

International audienceAccelerometry counts are widely used to quantify physical activity in an objective manner. ActiGraphTM accelerometers offer to record acceleration signal with different sampling frequency (fs). Nevertheless additional counts were shown to be computed by ActiLife software from acceleration signal with a sampling frequency fs>30 Hz compared to signal with default fs=30 Hz or multiple. This paper relies on the study of synthetic signals to point out the origin of this error and to recommend an adjusted method. A piecewise-frequency sinus time series (0-15 Hz) was generated at different sampling frequencies (fs=30, 50 and 100 Hz). The artificial acceleration raw signal was resampled to 30 Hz using different antialiasing lowpass filters before ActiLife count computation. The use of an antialiasing filter which did not properly attenuate aliasing replicas was found to induce aliasing frequencies within ActiLife bandpass filter which is the cause of extract activity counts. We were able to reproduce fictitious counts for acceleration around 10 Hz. A simple adjustment of antialiasing filter parameters allowed to avoid this problem. This study reproduces ActiLife counts processing from 50 and 100 Hz sampled signal. Count overestimations from fs=50 and 100 Hz signal were induced because of aliasing in the frequency bandwidth of the ActiLife count filter. This can be corrected by a relevant antialiasing filtering before ActiLife software processing or this can be done in high-level mathematical programing

Physical activity estimation from accelerometry

International audienceObjective physical activity (PA) quantification is traditionally achieved using lightweight accelerometers accounting for activity frequency, intensity and duration. The accelerometer data are usually converted into activity counts and these counts can be used on their own to quantify the intensity and duration of a PA period or they can serve as features for energy expenditure computation or activity classification. This paper investigates the way how Actigraph counts are computed. Several points are discussed regarding bandpass filtering and amplitude non-linearities that may hamper some analysis. Experimental data were used 1) to assess reconstructed filter performances to replicate ActiGraph counts during an urban-circuit involving 20 subjects wearing an ActiGraph GT3X+ and 2) explain filter limitations (e.g. plateauphenomenon) thanks to a treadmill test with incremental speed (n=4). This study reproduces well ActiLife filter and reveals the impact of band-pass filtering on ActiLife count conversion. These results provide some keys to interpret knowingly ActiLife count based studies

Effect of carbamylation on the structural properties of type I collagen

11-12 Octobr

Effect of Carbamylation on the structural properties of type I collagen.

Septembr

La carbamylation modifie les propriétés structurales du collagène de type I et ses interactions avec les polynucléaires neutrophiles humains

12 ma

Activation de p60-Src, de la PI-3 Kinase et de NF-kB induite par l'interaction entre les monocytes humains et le collagène de type I

Ma

Influence de la modification du collagène de type I par le méthylglyoxal sur l'activation des monocytes humains

Novembr