University of Grenoble

About: University of Grenoble is a education organization based out in Saint-Martin-d'Hères, France. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 25658 authors who have published 45143 publications receiving 909760 citations.

Intra-Articular Cytokine Levels in Adolescent Patients after Anterior Cruciate Ligament Tear.

Abstract: The treatment of anterior cruciate ligament (ACL) injuries in children and adolescents is challenging Preclinical and clinical studies investigated ACL repairing techniques in skeletally immature subjects However, intra-articular bioenvironment following ACL tear has not yet been defined in skeletally immature patients The aim of this study was to measure cytokine concentrations in the synovial fluid in adolescent population Synovial levels of IL-1β, IL-1ra, IL-6, IL-8, IL-10, and TNF-α were measured in 17 adolescent patients (15 boys) with ACL tears who underwent ACL reconstruction including acute (5), subacute (7), and chronic (5) phases Femoral growth plates were classified as “open” in three patients, “closing” in eight, and “closed” in six Eleven patients presented an ACL tear associated with a meniscal tear The mean Tegner and Lysholm scores ( ) of all patients were 8 ± 1 and 5076 ± 26, respectively IL-8, TNF-α, and IL-1β levels were significantly greater in patients with “open” physes IL-1ra and IL-1β levels were significantly higher in patients with ACL tear associated with a meniscal tear Poor Lysholm scores were associated with elevated IL-6 and IL-10 levels IL-10 levels positively correlated with IL-6 and IL-8 levels, whereas TNF-α concentration negatively correlated with IL-6 levels Skeletally immature patients with meniscal tears and open growth plates have a characteristic cytokine profile with particularly elevated levels of proinflammatory cytokines including IL-8, TNF-α, and IL-1β This picture suggests that the ACL tear could promote an intra-articular catabolic response in adolescent patients greater than that generally reported for adult subjects The study lacks the comparison with synovial samples from healthy skeletally immature knees due to ethical reasons Overall, these data contribute to a better knowledge of adolescent intra-articular bioenvironment following ACL injuries

The cosmic microwave background anisotropy power spectrum measured by archeops

Abstract: We present a determination by the Archeops experiment of the angular power spectrum of the cosmic microwave background anisotropy in 16 bins over the multipole range l=15-350. Archeops was conceived as a precursor of the Planck HFI instrument by using the same optical design and the same technology for the detectors and their cooling. Archeops is a balloon-borne instrument consisting of a 1.5 m aperture diameter telescope and an array of 21 photometers maintained at ~100 mK that are operating in 4 frequency bands centered at 143, 217, 353 and 545 GHz. The data were taken during the Arctic night of February 7, 2002 after the instrument was launched by CNES from Esrange base (Sweden). The entire data cover ~ 30% of the sky.This first analysis was obtained with a small subset of the dataset using the most sensitive photometer in each CMB band (143 and 217 GHz) and 12.6% of the sky at galactic latitudes above 30 degrees where the foreground contamination is measured to be negligible. The large sky coverage and medium resolution (better than 15 arcminutes) provide for the first time a high signal-to-noise ratio determination of the power spectrum over angular scales that include both the first acoustic peak and scales probed by COBE/DMR. With a binning of Delta(l)=7 to 25 the error bars are dominated by sample variance for l below 200. A companion paper details the cosmological implications.

Efficient analysis of large-scale genome-wide data with two R packages: bigstatsr and bigsnpr.

Abstract: Motivation Genome-wide datasets produced for association studies have dramatically increased in size over the past few years, with modern datasets commonly including millions of variants measured in dozens of thousands of individuals. This increase in data size is a major challenge severely slowing down genomic analyses, leading to some software becoming obsolete and researchers having limited access to diverse analysis tools. Results Here we present two R packages, bigstatsr and bigsnpr, allowing for the analysis of large scale genomic data to be performed within R. To address large data size, the packages use memory-mapping for accessing data matrices stored on disk instead of in RAM. To perform data pre-processing and data analysis, the packages integrate most of the tools that are commonly used, either through transparent system calls to existing software, or through updated or improved implementation of existing methods. In particular, the packages implement fast and accurate computations of principal component analysis and association studies, functions to remove single nucleotide polymorphisms in linkage disequilibrium and algorithms to learn polygenic risk scores on millions of single nucleotide polymorphisms. We illustrate applications of the two R packages by analyzing a case-control genomic dataset for celiac disease, performing an association study and computing polygenic risk scores. Finally, we demonstrate the scalability of the R packages by analyzing a simulated genome-wide dataset including 500 000 individuals and 1 million markers on a single desktop computer. Availability and implementation https://privefl.github.io/bigstatsr/ and https://privefl.github.io/bigsnpr/. Supplementary information Supplementary data are available at Bioinformatics online.

Diaphragmatic dysfunction in patients with ICU-acquired weakness and its impact on extubation failure

Abstract: Diaphragm function is rarely studied in intensive care patients with unit-acquired weakness (ICUAW) in whom weaning from mechanical ventilation is challenging. The aim of the present study was to evaluate the diaphragm function and the outcome using a multimodal approach in ICUAW patients. Patients were eligible if they were diagnosed for ICUAW [Medical Research Council (MRC) Score <48], mechanically ventilated for at least 48 h and were undergoing a spontaneous breathing trial. Diaphragm function was assessed using magnetic stimulation of the phrenic nerves (change in endotracheal tube pressure), maximal inspiratory pressure and ultrasonographically (thickening fraction). Diaphragmatic dysfunction was defined by a change in endotracheal tube pressure below 11 cmH2O. The endpoints were to describe the correlation between diaphragm function and ICUAW and its impact on extubation. Among 185 consecutive patients ventilated for more than 48 h, 40 (22 %) with a MRC score of 31 [20–36] were included. Diaphragm dysfunction was observed with ICUAW in 32 patients (80 %). Change in endotracheal tube pressure and MRC score were not correlated. Maximal inspiratory pressure was correlated with change in endotracheal tube pressure after magnetic stimulation of the phrenic nerves (r = 0.43; p = 0.005) and MRC score (r = 0.34; p = 0.02). Thickening fraction was less than 20 % in 70 % of the patients and was statistically correlated with change in endotracheal tube pressure (r = 0.4; p = 0.02) but not with MRC score. Half of the patients could be extubated without needing reintubation within 72 h. Diaphragm dysfunction is frequent in patients with ICU-acquired weakness (80 %) but poorly correlated with the ICU-acquired weakness MRC score. Half of the patients with ICU-acquired weakness were successfully extubated. Half of the patients who failed the weaning process died during the ICU stay.