79 research outputs found

    ESUR/ESUI consensus statements on multi-parametric MRI for the detection of clinically significant prostate cancer: quality requirements for image acquisition, interpretation and radiologists’ training

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    Objectives: This study aims to define consensus-based criteria for acquiring and reporting prostate MRI and establishing prerequisites for image quality. Methods: A total of 44 leading urologists and urogenital radiologists who are experts in prostate cancer imaging from the European Society of Urogenital Radiology (ESUR) and EAU Section of Urologic Imaging (ESUI) participated in a Delphi consensus process. Panellists completed two rounds of questionnaires with 55 items under three headings: image quality assessment, interpretation and reporting, and radiologists’ experience plus training centres. Of 55 questions, 31 were rated for agreement on a 9-point scale, and 24 were multiple-choice or open. For agreement items, there was consensus agreement with an agreement ≥ 70% (score 7–9) and disa

    ESUR/ESUI consensus statements on multi-parametric MRI for the detection of clinically significant prostate cancer: quality requirements for image acquisition, interpretation and radiologists’ training

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    Funder: Radboud University Medical CenterAbstract: Objectives: This study aims to define consensus-based criteria for acquiring and reporting prostate MRI and establishing prerequisites for image quality. Methods: A total of 44 leading urologists and urogenital radiologists who are experts in prostate cancer imaging from the European Society of Urogenital Radiology (ESUR) and EAU Section of Urologic Imaging (ESUI) participated in a Delphi consensus process. Panellists completed two rounds of questionnaires with 55 items under three headings: image quality assessment, interpretation and reporting, and radiologists’ experience plus training centres. Of 55 questions, 31 were rated for agreement on a 9-point scale, and 24 were multiple-choice or open. For agreement items, there was consensus agreement with an agreement ≥ 70% (score 7–9) and disagreement of ≤ 15% of the panellists. For the other questions, a consensus was considered with ≥ 50% of votes. Results: Twenty-four out of 31 of agreement items and 11/16 of other questions reached consensus. Agreement statements were (1) reporting of image quality should be performed and implemented into clinical practice; (2) for interpretation performance, radiologists should use self-performance tests with histopathology feedback, compare their interpretation with expert-reading and use external performance assessments; and (3) radiologists must attend theoretical and hands-on courses before interpreting prostate MRI. Limitations are that the results are expert opinions and not based on systematic reviews or meta-analyses. There was no consensus on outcomes statements of prostate MRI assessment as quality marker. Conclusions: An ESUR and ESUI expert panel showed high agreement (74%) on issues improving prostate MRI quality. Checking and reporting of image quality are mandatory. Prostate radiologists should attend theoretical and hands-on courses, followed by supervised education, and must perform regular performance assessments. Key Points: • Multi-parametric MRI in the diagnostic pathway of prostate cancer has a well-established upfront role in the recently updated European Association of Urology guideline and American Urological Association recommendations. • Suboptimal image acquisition and reporting at an individual level will result in clinicians losing confidence in the technique and returning to the (non-MRI) systematic biopsy pathway. Therefore, it is crucial to establish quality criteria for the acquisition and reporting of mpMRI. • To ensure high-quality prostate MRI, experts consider checking and reporting of image quality mandatory. Prostate radiologists must attend theoretical and hands-on courses, followed by supervised education, and must perform regular self- and external performance assessments

    Intratesticular varicocele: an easy diagnosis but unclear physiopathologic characteristics.

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    International audienceOBJECTIVE: Intratesticular varicocele (ITV) is an uncommon sonographic finding with controversial data concerning its prevalence and physiopathologic characteristics. The goal of this study was to determine the prevalence of ITV in a urogenital imaging department and to describe its sonographic features. METHODS: All identified cases of ITV were prospectively collected in the same imaging department. RESULTS: Intratesticular dilated veins (>2 mm) with a positive response to the Valsalva maneuver were referred to as ITV. Nine cases of ITV were detected in 8 patients (mean age, 60 years; range, 30-85 years) in a series of 1832 scrotal sonographic examinations performed over 5 years (0.4%). A history of homolateral scrotal surgery was found in 5 cases. In most cases, ITV was left sided (6/9) and located in the mediastinum testis (6/9) with associated extratesticular varicocele (8/9) and testicular hypotrophy (7/9). Five of the 7 hypotrophic testes had other causes of hypotrophy. CONCLUSIONS: Although variations do exist in the sonographic appearance of ITV, its specific sonographic and Doppler appearance should enable the radiologist to obviate further study. Intratesticular varicocele is often associated with ipsilateral testicular atrophy, but whether it is a cause or a consequence of testicular atrophy remains unclear

    RhoG GTPase Controls a Pathway That Independently Activates Rac1 and Cdc42Hs

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    RhoG is a member of the Rho family of GTPases that shares 72% and 62% sequence identity with Rac1 and Cdc42Hs, respectively. We have expressed mutant RhoG proteins fused to the green fluorescent protein and analyzed subsequent changes in cell surface morphology and modifications of cytoskeletal structures. In rat and mouse fibroblasts, green fluorescent protein chimera and endogenous RhoG proteins colocalize according to a tubular cytoplasmic pattern, with perinuclear accumulation and local concentration at the plasma membrane. Constitutively active RhoG proteins produce morphological and cytoskeletal changes similar to those elicited by a simultaneous activation of Rac1 and Cdc42Hs, i.e., the formation of ruffles, lamellipodia, filopodia, and partial loss of stress fibers. In addition, RhoG and Cdc42Hs promote the formation of microvilli at the cell apical membrane. RhoG-dependent events are not mediated through a direct interaction with Rac1 and Cdc42Hs targets such as PAK-1, POR1, or WASP proteins but require endogenous Rac1 and Cdc42Hs activities: coexpression of a dominant negative Rac1 impairs membrane ruffling and lamellipodia but not filopodia or microvilli formation. Conversely, coexpression of a dominant negative Cdc42Hs only blocks microvilli and filopodia, but not membrane ruffling and lamellipodia. Microtubule depolymerization upon nocodazole treatment leads to a loss of RhoG protein from the cell periphery associated with a reversal of the RhoG phenotype, whereas PDGF or bradykinin stimulation of nocodazole-treated cells could still promote Rac1- and Cdc42Hs-dependent cytoskeletal reorganization. Therefore, our data demonstrate that RhoG controls a pathway that requires the microtubule network and activates Rac1 and Cdc42Hs independently of their growth factor signaling pathways

    Effect of Impella During Veno-Arterial Extracorporeal Membrane Oxygenation on Pulmonary Artery Flow as Assessed by End-Tidal Carbon Dioxide

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    International audiencePeripheral veno-arterial extracorporeal membrane oxygenation (VA ECMO) exposes the patient to a pulmonary blood flow bypass and a left ventricle afterload increase. Impella, a catheter-mounted microaxial rotary pump, has been proposed for left ventricle (LV) unloading in combination with VA ECMO. In order to assess the effect of Impella on pulmonary flow and LV preload, we checked Doppler pulmonary artery velocity-time integral (pVTI) and LV diastolic diameter (LVED) by transesophageal echocardiography and end-tidal carbon dioxide (EtCO2) during a step-by-step increase in Impella flow (Impella ramp test). From 134 patients on VA ECMO retrieved from our database, 27 (20%) have benefited secondary Impella implantation, out of which 11 patients had available EtCO2, pVTI, and LVED measurements at various levels of Impella speeds. We observed a proportional increases in pVTI and EtCO2 and decrease in LVED (p ≤ 0.001) during Impella flow increase. There was a significant correlation between EtCO2 and ITV pulm (Pearson correlation coefficient 0.64; p = 0.006). The study shows that Impella improves pulmonary flow, an effect that can be easily measured by EtCO2 monitoring, and ensures LV discharge, allowing adapting Impella flow adequately to patient's individual needs

    Critical Activities of Rac1 and Cdc42Hs in Skeletal Myogenesis: Antagonistic Effects of JNK and p38 Pathways

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    The Rho family of GTP-binding proteins plays a critical role in a variety of cellular processes, including cytoskeletal reorganization and activation of kinases such as p38 and C-jun N-terminal kinase (JNK) MAPKs. We report here that dominant negative forms of Rac1 and Cdc42Hs inhibit the expression of the muscle-specific genes myogenin, troponin T, and myosin heavy chain in L6 and C2 myoblasts. Such inhibition correlates with decreased p38 activity. Active RhoA, RhoG, Rac1, and Cdc42Hs also prevent myoblast-to-myotube transition but affect distinct stages: RhoG, Rac1, and Cdc42Hs inhibit the expression of all muscle-specific genes analyzed, whereas active RhoA potentiates their expression but prevents the myoblast fusion process. We further show by two different approaches that the inhibitory effects of active Rac1 and Cdc42Hs are independent of their morphogenic activities. Rather, myogenesis inhibition is mediated by the JNK pathway, which also leads to a cytoplasmic redistribution of Myf5. We propose that although Rho proteins are required for the commitment of myogenesis, they differentially influence this process, positively for RhoA and Rac1/Cdc42Hs through the activation of the SRF and p38 pathways, respectively, and negatively for Rac1/Cdc42Hs through the activation of the JNK pathway

    Etude de charges optiques à intégrer dans des nanosats

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    International audienceNanosats or CubeSats are emerging technologies corresponding to miniaturized satellites with a wet mass between 1 and 10kg. In this study, we explored the possibility of doing earth observation in the longwave infrared. The challenge is to integrate the longest focal length as possible in a 2U volume dedicated to the optical payload. Another challenge is to use a low cost, lightweight and low power consumption microbolometer which requires high apertures optics. For these volumes, there is a competition between refractive designs, often more compact when having high apertures, and reflective designs, having a lower mass and being easily athermalized. The choice is not obvious and we studied a telephoto refractive design and an off-axis Three Mirror Anastigmat (TMA) reflective design. The key technology for the telephoto design is the use of chalcogenide glasses whereas the key technology for the TMA is the use of freeform surfaces
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