263 research outputs found
Ajustement des marqueurs d’insertion des tubes endotrachéaux selon l’âge gestationnel.
peer reviewedIntroduction et objectifs: le positionnement adéquat d’un tube endotrachéal (TET) peut être difficile en raison de la marge de manœuvre limitée associée aux faibles distances laryngo-trachéales du prématuré. Les marqueurs distaux censés faciliter l’évaluation de ce positionnement ne sont pas standardisés entre les fabriquants, et le marquage généralement unique par taille de tube ne tient pas compte de la croissance associée à l’âge gestationnel. L’objectif de l’étude est de décrire les distances entre les cordes vocales (CV) et la moitié de la trachée en fonction de l’âge gestationnel et proposer des nouveaux marquages adaptés.
Méthodes : la moitié de la longueur de la trachée ajoutée à la hauteur de la lame postérieure du cricoïde permet d’estimer la distance entre les CV et la moitié de la trachée (CV-MiTr). Ces longueurs sont issues à postériori d’une base de données prospective reprenant les distances détaillées du larynx et de la trachée mesurées lors d’autopsies de fœtus et nouveau-nés exempts de malformation des voies respiratoires (Fayoux et coll., Journal of anatomy 2008). Une corrélation est établie avec l’âge gestationnel.
Résultats : les données proviennent de 121 patients. Il existe une corrélation linéaire entre la distance CV-MiTr et l’AG (r=0,91; y=2,6043+0,6275x; p<.0001). Des marqueurs d’insertion positionnés à 17,7; 18,9; 20,8; 22,7; 24,6 et 26,4 mm correspondraient à des AG de 24, 26, 29, 32, 35 et 38 semaines respectivement. Ils pourraient être indiqués par des lignes de couleurs contrastées.
Conclusion : la relation linéaire entre la distance CV-mi-trachée et l’AG donne l’opportunité de revoir les marqueurs d’insertion des tubes endotrachéaux pour les patients les plus petits. Ces nouveaux marqueurs devraient être comparés cliniquement à ceux actuellement en usage avant d’être généralisés
Staging of regional nodes in AJCC stage I and II melanoma: 18FDG PET imaging versus sentinel node detection.
PRIMARY PURPOSE: The staging of regional nodes by means of sentinel node detection has been shown to accurately detect subclinical nodal metastases from cutaneous melanoma. On the other hand, the oncological applications of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG PET) are, nowadays, firmly established. However, the sensitivity of such metabolic imaging for staging the regional nodes in primary melanoma remains debatable. We prospectively assessed the actual value of PET for detecting sentinel node metastases in 21 consecutive patients presenting with early-stage melanoma. MATERIALS AND METHODS: Twenty-one melanoma patients scheduled for lymphatic mapping and sentinel lymphadenectomy underwent fully corrected whole-body PET using 18FDG. In all cases, the disease was initially classified as either stage I or II, from the latest version of the American Joint Committee on Cancer staging system. The sentinel node detection was systematically performed within the week following the PET scan. Serial sections of the sentinel nodes were analyzed by both conventional pathology and immunohistochemical staining. Metastatic sentinel nodes were also assessed for the size of tumor deposits and the degree of nodal involvement (focal, partial, or massive). The median follow-up time was 12 months. RESULTS: Six of the 21 patients (28.5%) had an involved sentinel node. PET was positive in only one case with a sentinel node >1 cm. In the five other cases, the sentinel nodes missed by PET were <1 cm with focal and/or partial involvements. One patient, free of regional nodal metastases in both sentinel node detection and PET imaging, had, however, a same-basin recurrence 3 months later. In another case, PET had one false positive result. Overall, the sentinel detection of subclinical nodal metastases had a sensitivity of 86%. PET detected only 14% of sentinel node metastases. CONCLUSIONS: Sentinel node detection remains the procedure of choice for detecting subclinical lymph node involvement from primary cutaneous melanoma. Owing to its limited spatial resolution, PET appears insufficiently sensitive to identify microscopic nodal metastases. As a practical consequence, metabolic imaging is not recommended as a first-line imaging strategy for staging regional lymph nodes in patients with stage I or II melanoma
Cell biology: exercises and methods
Cet ouvrage propose aux étudiants des premières années d’études supérieures une méthode progressive et conviviale pour comprendre et appliquer les concepts fondamentaux de la biologie cellulaire.
À la suite de rappels de cours, sous forme de fiches, chaque chapitre propose des exercices de difficulté croissante pour s’évaluer : QCM, questions Vrai/Faux et exercices de synthèse. Les corrigés détaillés mettent en évidence la méthodologie. Des ressources numériques avec des exercices d’entraînement supplémentaires complètent l’ouvrage.
Cette nouvelle édition, actualisée, s'enrichit de nouveaux QCM, Vrai/Faux et exercices
Multicenter evaluation of a new electrochemiluminescence immunoassay for everolimus concentrations in whole blood
Background: The precise monitoring of everolimus, an immunosuppressant drug, is vital for transplant recipients due to its narrow therapeutic range. This study evaluated the analytical performance of a new electrochemiluminescence immunoassay (ECLIA) for everolimus concentrations in whole blood.
Methods: Accuracy, imprecision, and sensitivity studies for the Roche Elecsys everolimus ECLIA were performed at 5 European laboratories. The ECLIA was compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods, as well as the Quantitative Microsphere System everolimus assay.
Results: Everolimus ECLIA accuracies were within the range 100% +/- 9%. Coefficients of variation (CVs) across the target range were <= 4.8% for repeatability and <= 8.4% for intermediate imprecision, whereas multisite reproducibility at lower (2.71 mcg/L) and higher everolimus concentrations (3.0-30.0 mcg/L) resulted in CVs of <= 13.7% and <= 12.4%, respectively. The CV at the assay's lower limit of quantification without considering bias was excellent, estimated as <= 9.3% at 0.5 mcg/L. The weighted Deming regression analysis, used for comparison of the results obtained by everolimus ECLIA and by LC-MS/MS methods, yielded a slope of 1.21 [95% confidence interval (CI): 1.15-1.26], intercept of 0.478 mcg/L (95% CI: 0.241-0.716), and a Pearson correlation coefficient (r) of 0.91. A single-site comparison between the ECLIA and the Quantitative Microsphere System assay revealed a slope of 1.05 (95% CI: 0.917-1.17), intercept of 1.03 mcg/L (95% CI: 0.351-1.70), and r of 0.91.
Conclusions: Based on these results, the Roche Elecsys everolimus ECLIA can be considered suitable for routine therapeutic drug monitoring. A positive bias was observed with respect to LC-MS/MS methods, suggesting that it may be necessary to rebaseline individual patients when switching from LC-MS/MS to the ECLIA; however, this must also be considered for any change of method for everolimus measurement
On digital sequences associated with Pascal's triangle
We consider the sequence of integers whose nth term has base-p expansion given by the nth row of Pascal's triangle modulo p (where p is a prime number). We first present and generalize well-known relations concerning this sequence. Then, with the great help of Sloane's On-Line Encyclopedia of Integer Sequences, we show that it appears naturally as a subsequence of a 2-regular sequence. Its study provides interesting relations and surprisingly involves odious and evil numbers, Nim-sum and even Gray codes. Furthermore, we examine similar sequences emerging from prime numbers involving alternating sum-of-digits modulo p. This note ends with a discussion about Pascal's pyramid involving trinomial coefficients
SURFACE ENGINEERING FOR PARTS MADE BY ADDITIVE MANUFACTURING
peer reviewedthe surface preparation of metal parts made by additive manufacturing (AM). AM is a technology of choice for manufacturing of parts with complex shapes (heat exchangers, RF supports, optical parts…) and integrated functions such as conformal cooling channels, clips, hinges, etc. This opens the door for lightweight parts which are of prime importance for space applications. The potential of the AM technologies is however impeded by the quite rough
surface finish that is observed on the as-manufactured parts. It is known that such a finish is likely to impact the
performance of the parts. Several post-treatment techniques can be applied to improve the surface condition of the AM parts. However, so far, the influence of the successive post-processing steps on the final properties is not well established. Therefore, a better understanding of the impact of surface characteristics on the material behaviour is needed to expand the use of AM for high performance parts.
The objective of this study, supported by ESA, is to propose and evaluate various surface finishing techniques for parts made by the AM technologies, in order to check their compatibility, evaluate their properties and derive
guidelines for future applications. CRM is the prime proposer of this study and is in charge of the surface treatment and characterisations. Sirris additive manufacturing facilities are used to produce the parts. Thales Alenia Space and Walopt are included into the industrial team to provide concrete application cases. The study focuses on metals. Two metals under study are presented here: AlSi10Mg and Ti6Al4V.
This paper is devoted to the early results of the first steps of surface preparation, namely material removal from the surface of the produced parts in order to improve their surface properties. As a first phase, tribo-finishing (TF) is tested on prototype parts to check its capabilities. Surface and volume parameters are analyzed, namely achieved roughness, material removal rate, location of removed material. The limitations in terms of geometry and applicability are discussed as well. These first observations should serve as guidelines for further application of AM for the design of parts used in space industry
A multicenter, open-label, randomized, proof-of-concept phase II clinical trial to assess the efficacy and safety of icatibant in patients infected with SARS-CoV-2 (COVID-19) and admitted to hospital units without invasive mechanical ventilation: study protocol (ICAT-COVID)
Background: COVID-19 has quickly become a global pandemic with a substantial number of deaths and is a considerable burden for healthcare systems worldwide. Although most cases are paucisymptomatic and limited to the viral infection-related symptoms, some patients evolve to a second phase, with an impaired inflammatory response (cytokine storm) that may lead to acute respiratory distress syndrome and death. This is thought to be caused by increased bradykinin synthesis. Methods: ICAT-COVID is a multicenter, randomized, open-label, proof-of-concept phase II clinical trial assessing the clinical efficacy and safety of adding icatibant to the standard of care in patients hospitalized with COVID-19 without invasive mechanical ventilation. Patients hospitalized with a confirmed COVID-19 pneumonia diagnosis (RTPCR or antigen test <= 10 days prior to randomization, and radiographic evidence of pulmonary infiltrates), rated 4 or 5' on the WHO's clinical status scale, are eligible. Patients will be randomized on a 1:1 ratio to either standard of care-plus-icatibant (experimental group) or to standard of care alone (control group). The experimental group will receive 30 mg of icatibant subcutaneously 3 times a day for 3 days (for a total of 9 doses). The expected sample size is 120 patients (60 per group) from 2 sites in Spain. Primary outcomes are the efficacy and safety of Icatibant. The main efficacy outcome is the number of patients reaching grades 2 or 1 on the WHO scale within 10 days of starting treatment. Secondary outcomes include long-term efficacy: number of patients discharged who do not present COVID-19-related relapse or comorbidity up until 28 days after discharge, and mortality. Discussion: Icatibant, a bradykinin type 2 receptor antagonist with proven effectiveness and safety against hereditary angioedema attacks, may be beneficial for COVID-19 patients by inhibiting bradykinin's action on endothelial cells and by inhibiting the SARS-CoV-2 M protease. Our working hypothesis is that treatment with standard of care-plus-icatibant is effective and safe to treat patients infected with SARS-CoV-2 admitted to hospital for pneumonia without invasive mechanical ventilation
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