Utility of enhanced CT for patients with suspected uncomplicated renal colic and no acute findings on non-enhanced CT

AIM: To evaluate the utility of contrast-enhanced computed tomography (CECT) for patients with suspected uncomplicated renal colic (URC) and no abnormalities on non-enhanced computed tomography (NECT). MATERIALS AND METHODS: The hospital institutional review board and ethics committee approved this retrospective study with a waiver of informed consent. Between January 2016 and April 2017, all consecutive adult patients who consulted at the adult Emergency Department (ED) with suspected URC and who had undergone both NECT and CECT were included retrospectively. The primary endpoint was prevalence of CECT-only diagnosis without acute findings on NECT. The risk factors for an acute finding were identified by logistic regression analysis. RESULTS: Among 126 patients with suspected URC, 12 were excluded. Among the 76 patients with no acute findings on NECT, CECT led to find acute lesions in 14/76 (18%) cases, but only 2/76 (3%) resulted in a change of management. Predictive factors of abnormal finding on CECT were: low renal clearance and high leukocyte count with OR 0.96 (95% confidence interval [CI]: 0.93-0.99), p=0.0189 and OR 5.79 (95% CI: 1.55-21.64), p=0.0091, respectively. CONCLUSIONS: In most cases, NECT is sufficient for screening patients with suspected URC. If leucocytosis and low renal function are present, stronger consideration may be given to CECT

Suspicious liver nodule in chronic liver disease: Usefulness of a second biopsy

PURPOSE: To assess the usefulness of a second biopsy when the first one was inconclusive in patients with a liver nodule found during the follow-up for chronic liver disease. MATERIALS AND METHODS: Among 381 patients (544 nodules) included in a prospective study designed to evaluate the accuracy of imaging for the diagnosis of small hepatocellular carcinoma (HCC) in chronic liver disease, 254 nodules were biopsied. The following histological results were considered as conclusive: HCC, dysplastic or regenerative nodule, and other identified tumors (benign or malignant). For nodules with inconclusive results (e.g. fibrosis or no definite focal lesion), a second biopsy was suggested, but was not mandatory. RESULTS: A total of 242 patients (194 men, 48 women; mean age, 61.9±9.5 [SD]; range: 40.2-89.0years) with 254 nodules underwent a first biopsy. Mean nodule diameter was 19.2±5.4mm (range: 10-33mm). The first biopsy was conclusive in 189/254 nodules (74.4%): 157 HCCs (83.1%), 11 regenerative nodules (5.8%), 10 dysplastic nodules (5.3%), 3 cholangiocarcinomas (1.6%), and 8 other tumors (4.2%). Among the 65 nodules for which the first biopsy was inconclusive, a second biopsy was performed for 17 nodules in 16 patients within 6 months of the first one. It was conclusive in 13/17 nodules (76.5%): 10 HCCs (76.9%), 2 dysplastic nodules (15.4%), and 1 other tumor (7.7%). In 4/17 nodules (23.5%), no definitive diagnosis could be provided. CONCLUSION: The diagnostic yield of a second biopsy of a suspicious lesion suggestive of HCC in chronic liver disease is not decreased compared to the first one. Repeated biopsy after a first negative one could be an alternative option to the follow-up of patients with chronic liver disease

Doppler ultrasonography devices, including elastography, allow for accurate diagnosis of severe liver fibrosis

OBJECTIVES: Advanced chronic liver disease is frequent yet largely underdiagnosed. Doppler-US is a common examination and we recently identified three simple Doppler-US signs associated with severe liver fibrosis. Recent Doppler-US devices include elastography modules, allowing for liver stiffness measurement (LSM). Our aim was to assess whether the use of elastography following positive simple Doppler-US signs improves the detection of severe liver fibrosis in a single Doppler-US examination. METHODS: 514 patients with chronic liver disease who consecutively underwent percutaneous liver biopsy were included in the study. All patients had a Doppler-US examination and LSM with Virtual Touch Quantification (VTQ) on the same day as a liver biopsy. A subset of 326 patients also had LSM with 2D shear wave elastography (SSI). Severe fibrosis was defined as Metavir F ≥ 3 on liver biopsy. RESULTS: Multivariate analysis confirmed our three simple Doppler-US signs (liver surface irregularity, splenomegaly ≥110 mm, and demodulation of hepatic veins) as independently associated with severe fibrosis. The presence of at least one of these three signs showed 85.6% sensitivity and 36.1% specificity for the diagnosis of severe liver fibrosis. Using VTQ (≥1.59 m/s) where there was a positive Doppler-US sign increased the specificity to 80.8%, at the cost of a decrease in sensitivity (73.7%). Similar results were obtained with SSI (≥9.5 kPa), with 73.3% specificity and 81.5% sensitivity. CONCLUSION: Elastography improves the accuracy of Doppler-US in the detection of severe fibrosis. This two-step procedure will help radiologists to accurately identify patients who need to be referred to specialist hepatologists during routine Doppler-US examinations

Direct Reprogramming of Mouse Fibroblasts into Functional Skeletal Muscle Progenitors

Skeletal muscle harbors quiescent stem cells termed satellite cells and proliferative progenitors termed myoblasts, which play pivotal roles during muscle regeneration. However, current technology does not allow permanent capture of these cell populations in vitro. Here, we show that ectopic expression of the myogenic transcription factor MyoD, combined with exposure to small molecules, reprograms mouse fibroblasts into expandable induced myogenic progenitor cells (iMPCs). iMPCs express key skeletal muscle stem and progenitor cell markers including Pax7 and Myf5 and give rise to dystrophin-expressing myofibers upon transplantation in vivo. Notably, a subset of transplanted iMPCs maintain Pax7 expression and sustain serial regenerative responses. Similar to satellite cells, iMPCs originate from Pax7+ cells and require Pax7 itself for maintenance. Finally, we show that myogenic progenitor cell lines can be established from muscle tissue following small-molecule exposure alone. This study thus reports on a robust approach to derive expandable myogenic stem/progenitor-like cells from multiple cell types

Single-phase flow in a pulsed column: Particle Image Velocimetry validation of a CFD based model

International audienceThe pulsed column is a widely used technology for liquid-liquid extraction processes in various industries. A thorough understanding of the biphasic flow in the column is essential to achieve process optimization and design. This paper is dedicated to the modelling of the single-phase flow which is strongly influencing the transport, breakage and coalescence of droplets in the apparatus. In this aim, a Computational Fluid Dynamics (CFD) model was developed for the simulation of a disc and doughnut pulsed column. To discuss the relevance of the RANS-based CFD model, the simulation results have been compared to Particle Image Velocimetry (Ply) measurements synchronized on the pulsation period. Since the behaviour of the dispersed phase is strongly dependent on the turbulent properties of the flow, such as eddies size and dissipation rate, the discussion is focussed on turbulent quantities. In this aim, 3D simulations were first carried out and compared to 2D axisymmetric ones. Then, different numerical schemes and turbulence models were compared to experimental data to choose the model offering the most accurate modelling of the single-phase flow

Distinct regulatory cascades govern extraocular and pharyngeal arch muscle progenitor cell fates

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The host RNA polymerase II C-terminal domain is the anchor for replication of the influenza virus genome

Summary The current model is that the influenza virus polymerase (FluPol) binds either to host RNA polymerase II (RNAP II) or to the acidic nuclear phosphoprotein 32 (ANP32), which drives its conformation and activity towards transcription or replication of the viral genome, respectively. Here, we provide evidence that the FluPol-RNAP II binding interface has a so far overlooked function for replication of the viral genome. Using a combination of cell-based and in vitro approaches, we show that the RNAP II C-terminal-domain, jointly with ANP32, enhances FluPol replication activity and we propose a model in which the host RNAP II is the anchor for transcription and replication of the viral genome. Our data open new perspectives on the spatial coupling of viral transcription and replication and the coordinated balance between these two activities

Unenhanced CT for clinical triage of elderly patients presenting to the emergency department with acute abdominal pain

International audiencePurpose: The purpose of this study was to compare the diagnostic accuracy and inter-reader agreement of unenhanced computed tomography (CT) to those of contrast-enhanced CT for triage of patients older than 75years admitted to emergency department (ED) with acute abdominal pain (AAP).Patients and methods: Two hundred and eight consecutive patients presenting with AAP to the ED who underwent CT with unenhanced and contrast-enhanced images were retrospectively included. There were 90 men and 118 women with a mean age of 85.4±4.9 (SD) (range: 75-101.4years). Three readers reviewed unenhanced CT images first, and then unenhanced and contrast-enhanced CT images as a single set. Diagnostic accuracy was compared to the standard of reference defined as the final diagnosis obtained after complete clinico-biological and radiological evaluation. Correctness of the working diagnosis proposed by the ED physician was evaluated. Intra- and inter-reader agreements were calculated using the kappa test and interclass correlation. Subgroup analyses were performed for patients requiring only conservative management and for those requiring intervention.Results: Diagnostic accuracy ranged from 64% (95% CI: 62-66%) to 68% (95% CI: 66-70%) for unenhanced CT, and from 68% (95% CI: 66-70%) to 71% (95% CI: 69-73%) for both unenhanced and contrast-enhanced CT. Contrast-enhanced CT did not significantly improve the diagnostic accuracy (P=0.973-0.979). CT corrected the working diagnosis proposed by the ED physician in 59.1% (range: 58.1-60.0%) and 61.2% (range: 57.6-65.5%) of patients before and after contrast injection (P>0.05). Intra-observer agreement was moderate to substantial (k=0.513-0.711). Inter-reader agreement was substantial for unenhanced (kappa=0.745-0.789) and combined unenhanced and contrast-enhanced CT (kappa=0.745-0.799). Results were similar in subgroup analyses.Conclusion: Unenhanced CT alone is accurate and associated with high degrees of inter-reader agreement for clinical triage of patients older than 75years with AAP in the emergency setting

Use of synchronised PIV to measure a pulsed flow velocity field in a discs and doughnuts column

The study presented here deals with the pulsed flow in a discs and doughnuts column. We aim for the understanding of the hydrodynamic properties of the one-phase flow. We experimentaly investigate the pulsation intensity effects on flow structure. Velocity fields from the PIV process reveal that the use of pulsation intensity (Amplitude x Frequency) can only be limited to qualitative analysis. No obvious tendency of the flow structure and intensity could be linked to it. Moreover, an unexpected eddy stemming from the lack of centenring of the packings appeared in the measured velocity fields, highlighting the asymmetry of the flow

Reliability of extracellular contrast versus gadoxetic acid in assessing small liver lesions using liver imaging reporting and data system v.2018 and European association for the study of the liver criteria.

Background & aims: The diagnostic accuracy of Liver Imaging Reporting and Data System (LI-RADS) v.2018 and European Association for the Study of the Liver (EASL) criteria for the diagnosis of HCC have been widely evaluated, but their reliability should be investigated. We aimed to assess and compare the reliability of LI-RADS v.2018 and EASL criteria for the diagnosis of HCC using MRI with extracellular contrast agents (ECAs) and gadoxetic acid (GA) and determine the effect of ancillary features on LI-RADS reliability. Approach & results: Ten readers reviewed MRI studies of 92 focal liver lesions measuring <3 cm acquired with ECAs and GA <1 month apart from two prospective trials, assessing EASL criteria, LI-RADS major and ancillary features, and LI-RADS categorization with and without including ancillary features. Inter-reader agreement for definite HCC diagnosis was substantial and similar for the two contrasts for both EASL and LI-RADS criteria. For ECA-MRI and GA-MRI, respectively, inter-reader agreement was k = 0.72 (95% CI, 0.63-0.81) and k = 0.72 (95% CI, 0.63-0.80); for nonrim hyperenhancement, k = 0.63 (95% CI, 0.54-0.72) and k = 0.57 (95% CI, 0.48-0.66); and for nonperipheral washout, k = 0.49 (95% CI, 0.40-0.59) and k = 0.48 (95% CI, 0.37-0.58) for enhancing capsule. The inter-reader agreement for LI-RADS after applying ancillary features remained in the same range of agreement. Conclusions: Agreement for definite HCC was substantial and similar for both scoring systems and the two contrast agents in small focal liver lesions. Agreement for LI-RADS categorization was lower for both contrast agents, and including LI-RADS ancillary features did not improve agreement