Determination of reliability criteria for liver stiffness evaluation by transient elastography

UNLABELLED: Liver stiffness evaluation (LSE) is usually considered as reliable when it fulfills all the following criteria: ≥10 valid measurements, ≥60% success rate, and interquartile range / median ratio (IQR/M) ≤0.30. However, such reliable LSE have never been shown to be more accurate than unreliable LSE. Thus, we aimed to evaluate the relevance of the usual definition for LSE reliability, and to improve reliability by using diagnostic accuracy as a primary outcome in a large population. 1,165 patients with chronic liver disease from 19 French centers were included. All patients had liver biopsy and LSE. 75.7% of LSE were reliable according to the usual definition. However, these reliable LSE were not significantly more accurate than unreliable LSE with, respectively: 85.8% versus 81.5% well-classified patients for the diagnosis of cirrhosis (P = 0.082). In multivariate analyses with different diagnostic targets, LSE median and IQR/M were independent predictors of fibrosis staging, with no significant influence of ≥10 valid measurements or LSE success rate. These two reliability criteria determined three LSE groups: "very reliable" (IQR/M ≤0.10), "reliable" (0.10< IQR/M ≤0.30, or IQR/M >0.30 with LSE median <7.1 kPa), and "poorly reliable" (IQR/M >0.30 with LSE median ≥7.1 kPa). The rates of well-classified patients for the diagnosis of cirrhosis were, respectively: 90.4%, 85.8%, and 69.5% (P < 10(-3) ). According to these new reliability criteria, 9.1% of LSE were poorly reliable (versus 24.3% unreliable LSE with the usual definition, P < 10(-3) ), 74.3% were reliable, and 16.6% were very reliable. CONCLUSION: The usual definition for LSE reliability is not relevant. LSE reliability depends on IQR/M according to liver stiffness median level, defining thus three reliability categories: very reliable, reliable, and poorly reliable LSE. (HEPATOLOGY 2013)

Long-term follow-up of patients with congenital myasthenic syndrome caused by COLQ mutations.

Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous inherited disorders characterized by impaired neuromuscular transmission. Mutations in the acetylcholinesterase (AChE) collagen-like tail subunit gene (COlQ) cause recessive forms of synaptic CMS with end plate AChE deficiency. We present data on 15 COLQ -mutant CMS carrying 16 different mutations (9 novel ones identified) followed-up for an average period of 10 ears. The mean age at the first examination was 19 ears old (range from 3 to 48). We report relapses during short or long-term periods characterized by worsening of muscle weakness sometimes associated with respiratory crises. All the relapses ended spontaneously or with 3-4 DAP or ephedrine with no residual impairment. The triggering factors identified were esterase inhibitors, effort, puberty or pregnancy highlighting the importance of hormonal factors. There was no genotype-phenotype correlation. At the end of the follow-up, 80% of patients were ambulant and 87% of patients had no respiratory trouble in spite of severe relapses

Brain anomalies in maternally inherited diabetes and deafness syndrome

International audienc

Proteomic analysis identifies argininosuccinate synthase 1 as a useful biomarker for hepatocellular adenoma classification and patient management

International audienc

Cooling Channel Analysis of a LOX/LCH4 Rocket Engine Demonstrator

A computational procedure able to describe the coupled hot-gas/wall/coolant environment that occurs in most liquid rocket engines is presented and demonstrated. The coupled analysis is performed by loose coupling of the two-dimensional axisymmetric Reynolds-Averaged Navier-Stokes equations for the hot-gas flow and the conjugate three-dimensional model for the coolant flow and solid material heat transfer in the regenerative cooling circuit. The latter model is in turn based on the coupled Reynolds-Averaged Navier-Stokes equations for the coolant flow and Fourier equation for the thermal conduction in the solid material. In this study, the thermal behavior of a regeneratively cooled oxygen/methane engine demonstrator is analyzed in detail. Starting from a nominal operative condition of the engine, different levels of channel surface roughness and coolant mass flow rate are considered in order to understand their influence on the heat transfer capability of the cooling system. Results show that the heat transfer can be markedly impaired if the operating parameters undergo rather minor changes with respect to the nominal condition

Analysis of Curved-Cooling-Channel Flow and Heat Transfer in Rocket Engines

Coolant-flow modeling in regeneratively cooled rocket engines fed with turbomachinery is a challenging task because of the high wall-temperature gradient, the high Reynolds number, the high aspect ratio of the channel cross section, and the curved geometry. In the present study, to better comprehend the role of the thrust-chamber shape of a rocket engine on the heat exchange, computations of supercritical hydrogen flow in single- and double-curvature channels are carried out. In particular, a parametric numerical analysis of the flow in an asymmetrically heated rectangular channel with a high aspect ratio and various radii of curvature is performed by means of a Reynolds. averaged Navier Stokes solver for real fluids, which is validated against experimental data of heated and curved. channel flow taken from open literature. Results permit the effect of curvature on global heat transfer coefficient, pressure loss, and bulk temperature increase to be quantified