Analyse statistique de données radiomiques et métabolomiques : prédiction des lésions mammaires triple-négatives

International audienceLa caractérisation de l’hétérogénéité tumorale à partir des images médicales (appeléeaussi radiomique) et de l’extraction de données omiques est un enjeu majeur en cancérologie,notamment dans la mise en place de la médecine de précision. Or actuellement, le lien entre lesvariables radiomiques (VR) et les caractéristiques biologiques des lésions est encore mal connu.L’objectif de ce travail est d’étudier la corrélation entre les VR et les variables métabolomiques (VM)dans le cancer du sein, et d’analyser leur capacité à prédire le sous-type immunohistochimique deslésions

Radiology

Background: A target mismatch profile can identify good clinical response to recanalization after acute ischemic stroke, but does not consider region specificities. Purpose: To test whether location-weighted infarction core and mismatch, determined from diffusion and perfusion MRI performed in patients with acute stroke, could improve prediction of good clinical response to mechanical thrombectomy compared with a target mismatch profile. Materials and Methods: In this secondary analysis, two prospectively collected independent stroke data sets (2012–2015 and 2017–2019) were analyzed. From the brain before stroke (BBS) study data (data set 1), an eloquent map was computed through voxel-wise associations between the infarction core (based on diffusion MRI on days 1–3 following stroke) and National Institutes of Health Stroke Scale (NIHSS) score. The French acute multimodal imaging to select patients for mechanical thrombectomy (FRAME) data (data set 2) consisted of large vessel occlusion–related acute ischemic stroke successfully recanalized. From acute MRI studies (performed on arrival, prior to thrombectomy) in data set 2, target mismatch and eloquent (vs noneloquent) infarction core and mismatch were computed from the intersection of diffusion- and perfusion-detected lesions with the coregistered eloquent map. Associations of these imaging metrics with early neurologic improvement were tested in multivariable regression models, and areas under the receiver operating characteristic curve (AUCs) were compared. Results: Data sets 1 and 2 included 321 (median age, 69 years [IQR, 58–80 years]; 207 men) and 173 (median age, 74 years [IQR, 65–82 years]; 90 women) patients, respectively. Eloquent mismatch was positively and independently associated with good clinical response (odds ratio [OR], 1.14; 95% CI: 1.02, 1.27; P =.02) and eloquent infarction core was negatively associated with good response (OR, 0.85; 95% CI: 0.77, 0.95; P =.004), while noneloquent mismatch was not associated with good response (OR, 1.03; 95% CI: 0.98, 1.07; P =.20). Moreover, adding eloquent metrics improved the prediction accuracy (AUC, 0.73; 95% CI: 0.65, 0.81) compared with clinical variables alone (AUC, 0.65; 95% CI: 0.56, 0.73; P =.01) or a target mismatch profile (AUC, 0.67; 95% CI: 0.59, 0.76; P =.03). Conclusion: Location-weighted infarction core and mismatch on diffusion and perfusion MRI scans improved the identification of patients with acute stroke who would benefit from mechanical thrombectomy compared with the volume-based target mismatch profile. © RSNA, 2022.Translational Research and Advanced Imaging Laborator

Time to treatment with bridging intravenous alteplase before endovascular treatment:subanalysis of the randomized controlled SWIFT-DIRECT trial.

BACKGROUND We hypothesized that treatment delays might be an effect modifier regarding risks and benefits of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT). METHODS We used the dataset of the SWIFT-DIRECT trial, which randomized 408 patients to IVT+MT or MT alone. Potential interactions between assignment to IVT+MT and expected time from onset-to-needle (OTN) as well as expected time from door-to-needle (DTN) were included in regression models. The primary outcome was functional independence (modified Rankin Scale (mRS) 0-2) at 3 months. Secondary outcomes included mRS shift, mortality, recanalization rates, and (symptomatic) intracranial hemorrhage at 24 hours. RESULTS We included 408 patients (IVT+MT 207, MT 201, median age 72 years (IQR 64-81), 209 (51.2%) female). The expected median OTN and DTN were 142 min and 54 min in the IVT+MT group and 129 min and 51 min in the MT alone group. Overall, there was no significant interaction between OTN and bridging IVT assignment regarding either the functional (adjusted OR (aOR) 0.76, 95% CI 0.45 to 1.30) and safety outcomes or the recanalization rates. Analysis of in-hospital delays showed no significant interaction between DTN and bridging IVT assignment regarding the dichotomized functional outcome (aOR 0.48, 95% CI 0.14 to 1.62), but the shift and mortality analyses suggested a greater benefit of IVT when in-hospital delays were short. CONCLUSIONS We found no evidence that the effect of bridging IVT on functional independence is modified by overall or in-hospital treatment delays. Considering its low power, this subgroup analysis could have missed a clinically important effect, and exploratory analysis of secondary clinical outcomes indicated a potentially favorable effect of IVT with shorter in-hospital delays. Heterogeneity of the IVT effect size before MT should be further analyzed in individual patient meta-analysis of comparable trials. TRIAL REGISTRATION NUMBER URL: https://www. CLINICALTRIALS gov ; Unique identifier: NCT03192332

El Perú en PISA 2018 : informe nacional de resultados

El presente informe da cuenta de los principales resultados de los estudiantes peruanos en esta evaluación de altos niveles de exigencia, propios de los estándares de países desarrollados de la OECD, bajo el interés de tener información confiable sobre algunos de los principales retos a futuro que, en materia de aprendizaje de los estudiantes, debe afrontar nuestro sistema educativo. En general, se presentan los resultados de Lectura, Matemática y Ciencia y se analiza en mayor medida los resultados de Lectura por ser la competencia priorizada en PISA 2018. Además, si bien en este ciclo Perú participó también de la prueba de Educación financiera, en este informe no se presentan los resultados de esta competencia. Estos se encuentran disponibles en el informe correspondiente a esta evaluación (Organisation for Economic Co-operation and Development, 2020). El primer capítulo presenta las características generales de la evaluación, los países participantes, la población evaluada y una descripción general de las competencias evaluadas, así como de los instrumentos aplicados y las formas en que PISA reporta los resultados. Además, se describe brevemente uno de los aspectos novedosos del ciclo de evaluación PISA 2018: la aplicación de un modelo adaptativo para la prueba de Lectura, área de énfasis de este ciclo. El segundo capítulo presenta los resultados de la competencia lectora de los estudiantes peruanos en PISA 2018. En primer lugar, se describe el modelo de evaluación de Lectura y se detallan los niveles de desempeño que pueden alcanzar los estudiantes. En segundo lugar, se muestran los resultados para los países participantes, así como el desempeño de los países latinoamericanos, incluyendo Perú, donde se analiza cómo estos han evolucionado a lo largo de los años. En tercer lugar, se analizan los resultados en función de las características de los estudiantes y de las escuelas, considerando también la tendencia del desempeño de estos grupos poblacionales en el tiempo. Finalmente, como cuarto punto, se presentan algunos factores asociados al desarrollo de la competencia lectora de los estudiantes peruanos. Los capítulos tercero y cuarto están dedicados a la competencia matemática y la competencia científica, respectivamente. Se presenta una breve descripción del modelo de evaluación y de los niveles de desempeño para cada competencia. Asimismo, se brindan los resultados de los países participantes, haciendo énfasis en los países latinoamericanos junto con la tendencia de los resultados en los ciclos PISA. También se presentan los resultados según características del estudiante y de las escuelas, considerando los cuatro últimos periodos de evaluación. El quinto capítulo presenta otra de las principales novedades de este informe en relación con informes de ciclos anteriores de PISA: un análisis de la relación entre los resultados de PISA 2018 con los resultados de las evaluaciones censales de estudiantes (ECE) llevadas a cabo hasta el año 2016. Este análisis, además de brindar datos relevantes sobre los resultados de una cohorte de estudiantes peruanos a lo largo de su trayectoria educativa, sienta las bases de estudios que permitan revelar la riqueza e importancia de la complementariedad entre la información obtenida a nivel de evaluaciones nacionales y las evaluaciones internacionales de estudiantes que se llevan a cabo en nuestro país. En el sexto capítulo, se presentan las conclusiones principales del estudio de PISA 2018 en el país y se desarrolla una sección adicional de recomendaciones para política educativa a la luz de toda la información elaborada. En atención a los desafíos en materia de rendimiento, pero, fundamentalmente, en materia de brechas de inequidad que presentan los resultados de PISA 2018 a nivel nacional, se espera que esta información sirva de insumo para la toma de decisiones futuras en política educativa que contribuyan a la mejora de la calidad de los aprendizajes de todos los estudiantes peruanos

Effect of extracranial lesion severity on outcome of endovascular thrombectomy in patients with anterior circulation tandem occlusion: analysis of the TITAN registry

Introduction Endovascular treatment (EVT) for tandem occlusion (TO) of the anterior circulation is complex but effective. The effect of extracranial internal carotid artery (EICA) lesion severity on the outcomes of EVT is unknown. In this study we investigated the effect of EICA lesion severity on the outcomes of tandem occlusion EVT. Methods A multicenter retrospective TITAN (Thrombectomy In TANdem lesions) study that included 18 international endovascular capable centers was performed. Patients who received EVT for atherosclerotic TO with or without EICA lesion intervention were included. Patients were divided into two groups based on the EICA lesion severity (high-grade stenosis (>= 90% North American Symptomatic Carotid Endarterectomy Trial) vs complete occlusion). Outcome measures included the 90-day clinical outcome (modified Rankin Scale score (mRS)), angiographic reperfusion (modified Thrombolysis In Cerebral Ischemia (mTICI) at the end of the procedure), procedural complications, and intracranial hemorrhage at 24 hours follow-up. Results A total of 305 patients were included in the study, of whom 135 had complete EICA occlusion and 170 had severe EICA stenosis. The EICA occlusion group had shorter mean onset-to-groin time (259 +/- 120 min vs 305 +/- 202 min;p=0.037), more patients with diabetes, and fewer with hyperlipidemia. With respect to the outcome, mTICI 2b-3 reperfusion was lower in the EICA occlusion group (70% vs 81%;p=0.03). The favorable outcome (90-day mRS 0-2), intracerebral hemorrhage and procedural complications were similar in both groups. Conclusion Atherosclerotic occlusion of the EICA in acute tandem strokes was associated with a lower rate of mTICI 2b-3 reperfusion but similar functional and safety outcomes when compared with high-grade EICA stenosis

Robust multimodality registration for brain mapping

r r Abstract: We present a robust intrasubject registration method for the synergistic use of multiple neuroimaging modalities, with applications to magnetic resonance imaging (MRI), functional MRI, perfusion MRI, MR spectroscopy, and single-photon emission computed tomography (SPECT). This method allows user-friendly processing of difficult examinations (low spatial resolution, advanced pathology, motion during acquisition, and large areas of focal activation). Registration of three-dimensional (3D) brain scans is initially estimated by first-order moment matching, followed by iterative anisotrophic chamfer matching of brain surfaces. Automatic brain surface extraction is performed in all imaging modalities. A new generalized distance definition and new specific methodologies allow registration of scans that cover only a limited range of brain surface. A new semiautomated supervision scheme allows fast and intuitive corrections of possible false automatic registration results. The accuracy of the MRI/SPECT anatomical-functional correspondence obtained was evaluated using simulations and two difficult clinical populations (tumors and degenerative brain disorders). The average discrimination capability of SPECT (12.4 mm in-plane resolution, 20 mm slice thickness) was found to be better than 5 mm after registration with MRI (5 mm slice thickness). Registration accuracy was always better than imaging resolution. Complete 3D MRI and SPECT registration time ranged between 6–11 min, in which surface matching represented 2–3 min. No registration failure occurred. In conclusion, the application of several new image processing techniques allowed efficient and robust registration. Hum. Brain Mapping 5:3–17

Smoothness and degrees of freedom restrictions when using SPM 99

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What can we learn from the platelet lipidome?

Besides their proteome, platelets use, in all responses to the environmental cues, a huge and diverse family of hydrophobic and amphipathic small molecules involved in structural, metabolic and signaling functions; the lipids. Studying how platelet lipidome changes modulate platelet function is an old story constantly renewed through the impressive technical advances allowing the discovery of new lipids, functions and metabolic pathways. Technical progress in analytical lipidomic profiling by top-of-the-line approaches such as nuclear magnetic resonance and gas chromatography or liquid chromatography coupled to mass spectrometry enables either large-scale analysis of lipids or targeted lipidomics. With the support of bioinformatics tools and databases, it is now possible to investigate thousands of lipids over a concentration range of several orders of magnitude. The lipidomic landscape of platelets is considered a treasure trove, not only able to expand our knowledge of platelet biology and pathologies but also to bring diagnostic and therapeutic opportunities. The aim of this commentary article is to summarize the advances in the field and to highlight what lipidomics can tell us about platelet biology and pathophysiology

Que pourrait-être une sociologie de la gestion ? Actes de la journée d'études du RT 30 de l'AFS, 11 mars 2005

Créé à l'issue du congrès de l'AFS à Villetaneuse en 2004, le réseau thématique "sociologiede la gestion"(RT 30) se donne pour objet l'étude des dispositifs, outils ou pratiques de gestion, en entreprise comme hors entreprise (associations, sphère domestique,..). Dans le cadre des travaux qui sont apparus nécessaires pour conforter l’existence d’un courant de recherche s’intéressant à la sociologie de la gestion, une journée d'étude a été organisée le 11 mars 2005 pour clarifier un certain nombre de points de débat. En effet, lors du dernier congrès de l'AFS, au sein du Réseau Thématique 30 (février 2004), certains d'entre nous ont eu le sentiment qu'une confusion s'instaurait entre «sociologie de la gestion» et «gestion». Aussi, une prise de distance e un étayage théorique ont paru nécessaires. Plus largement, il s'agissait d'interroger les liens que la sociologie de la gestion pouvait entretenir avec d'autres disciplines (sociologie du travail, sociologie économique, histoire...) afin de mieux délimiter le champ de la sociologie de la gestion et ses ancrages disciplinaires.De même, certaines interventions ont laissé penser que la définition des «dispositifs de gestion» n'était pas nécessairement commune, partagée par tous et qu'il serait peut-être utile de procéder à une catégorisation ou typologie de cet objet (d'étude). Par ailleurs, la connaissance sociologique de la gestion en dehors de la France et, plus particulièrement, hors OCDE, pouvait constituer une manière de prendre du champ par rapport à ces confusions et brouillages. [...

SPECT memory activation studies thanks to non-rigid automated 3D image registration

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