Mesure objective de la perception des effets de blocs dans le cas de séquence d'images codées par transformée

L'un des inconvénients majeurs des techniques de codage par Transformée en Cosinus Discrète (TCD) est l'apparition de discontinuités aux frontières entre les blocs adjacents, dues à la quantification grossière des coefficients transformés. Un modèle de perception des effets de blocs est défini qui prédit l'importance de cette dégradation dans chaque image de la séquence vidéo. Celui-ci intègre les propriétés essentielles de la vision humaine telles que la sensibilité spatio-temporelle au contraste et les phénomènes de masquage spatial et temporel. Cette mesure est ensuite utilisée dans un post-traitement adaptatif pour la réduction des effets de blocs dans les images. Les résultats obtenus montrent que les images corrigées présentent une amélioration sensible de la qualité visuelle

Global Retinoblastoma Presentation and Analysis by National Income Level.

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

Travel burden and clinical presentation of retinoblastoma: analysis of 1024 patients from 43 African countries and 518 patients from 40 European countries

BACKGROUND: The travel distance from home to a treatment centre, which may impact the stage at diagnosis, has not been investigated for retinoblastoma, the most common childhood eye cancer. We aimed to investigate the travel burden and its impact on clinical presentation in a large sample of patients with retinoblastoma from Africa and Europe. METHODS: A cross-sectional analysis including 518 treatment-naïve patients with retinoblastoma residing in 40 European countries and 1024 treatment-naïve patients with retinoblastoma residing in 43 African countries. RESULTS: Capture rate was 42.2% of expected patients from Africa and 108.8% from Europe. African patients were older (95% CI -12.4 to -5.4, p<0.001), had fewer cases of familial retinoblastoma (95% CI 2.0 to 5.3, p<0.001) and presented with more advanced disease (95% CI 6.0 to 9.8, p<0.001); 43.4% and 15.4% of Africans had extraocular retinoblastoma and distant metastasis at the time of diagnosis, respectively, compared to 2.9% and 1.0% of the Europeans. To reach a retinoblastoma centre, European patients travelled 421.8 km compared to Africans who travelled 185.7 km (p<0.001). On regression analysis, lower-national income level, African residence and older age (p<0.001), but not travel distance (p=0.19), were risk factors for advanced disease. CONCLUSIONS: Fewer than half the expected number of patients with retinoblastoma presented to African referral centres in 2017, suggesting poor awareness or other barriers to access. Despite the relatively shorter distance travelled by African patients, they presented with later-stage disease. Health education about retinoblastoma is needed for carers and health workers in Africa in order to increase capture rate and promote early referral

The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

Ex Vivo Lung Perfusion: A Chance for β2-Agonists to Prove Their Clinical Efficacy in Acute Lung Injury?

International audienc

ETUDE IN VIVO DE LA COMPOSITION IONIQUE DU LIQUIDE ALVEOLAIRE ET DU LIQUIDE TRACHEAL

GRENOBLE1-BU Médecine pharm. (385162101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Mesures répétées de la perméabilité capillaro-alvéolaire à une macromolécule au cours de modèles de lésion pulmonaire inflammatoire chez le chien

Nous avons mis au point une méthode de lavage broncho-alvéolaire permettant d'effectuer in vivo des mesures répétées (toutes les 15 min. pendant 3h30.) de la perméabilité capillaro-alvéolaire à une macromolécule (FlTC-dextran). Sur un modèle pré-clinique de lésion à l'acide oléique (AO) on observe, en 30 minutes un pic de perméabilité au FlTC-dextran. La perméabilité décroît ensuite lentement jusqu'à la fin de l'expérience. Nous avons testé les effets de la terbutaline, un b2-agoniste réputé réduire in vitro l'augmentation de perméabilité dans les lésions pulmonaires inflammatoires. Une perfusion de terbutaline débutée 10 min. après la lésion à l'AO ne modifie pas l'évolution de la perméabilité. Une perfusion tardive de terbutaline (90 min. aprés la lésion) aggrave la perméabilité. Comme l'index cardiaque et la pression capillaire augmentent au cours de la perfusion de terbutaline, nous supposons que la terbutaline recrute des capillaires lésés et aggrave la perméabilité à la phase tardive de la lésion à l'AO.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Deconstructing cluster identity : place branding and trademarking by cluster organizations

The paper defines ‘cluster identity’ as an intangible attribute of clusters comprised of place branding and trademarking by cluster organizations, respectively anchored in a ‘logic of belonging’ and a ‘logic of similarity’. We expand the taxonomy of proximities and their dynamics according to their belonging/similarity logic and their tangible/intangible nature. As illustrated in the context of the Bordeaux wine region of France, we find that a prevailing logic of belonging leads to reputational inertia. We propose that trademarking by cluster organizations can facilitate the adaptation of cluster identity, thereby emphasizing its potential as an instrument for cluster managers to engage in community-building

Monitoring the capillary-alveolar leakage in an A.R.D.S. model using broncho-alveolar lavage.

International audienceOBJECTIVES: We developed a modified broncho-alveolar lavage (BAL) technique in order to perform repeated measurements of capillary-alveolar leakage of a macromolecule in oleic acid (OA)-induced lung injury. METHODS: BAL was performed in anesthetized dogs in a closed lung sampling site, using a bronchoscope fitted with an inflatable cuff. Fluorescein-labeled Dextran (FITC-D70) was continuously infused and its concentration measured in plasma and BAL fluid. A two-compartment model (blood and alveoli) was used to calculate K(AB), the transport-rate coefficient of FITC-D70 from blood to alveoli. K(AB) was estimated every 15 minutes over three hours. RESULTS: K(AB), close to zero at base-line both in control (n = 3) and in OA-injured lungs (n = 7), reached a peak in permeability 30 minutes after the induction of OA injury (K(AB) = 1.43 +/- 0.31 . 10(- 3) . minutes(- 1)), followed by a slow recovery. CONCLUSIONS: We conclude that this technique allows the monitoring of capillary-alveolar transport of macromolecules in in vivo experimental models. This monitoring may prove useful to study the mechanisms of the exudative stage of acute lung injury and to test therapies aimed at slowing the alveolar accumulation of plasma proteins and procoagulant factors that contribute to alveolar fibrosis