Etude de préparations à base de plantes à risque fongique chez l'enfant immunodéprimé (à propos de 12 cas)

Introduction: Les sujets immunodéprimés sont à risque d'infections sévères notamment fongiques. De plus en plus de familles administrent des compléments alimentaires, sous forme de préparations à base de plantes, à leur enfant dans un sentiment d'innocuité non corrélé aux mises en gardes scientifiques publiées. A propos de plusieurs situations, nous nous sommes interrogées sur le risque fongique de ces produits chez l'immunodéprimé. Matériels et méthodes: D'octobre 2009 à février 2013, nous avons recueilli les données de 12 patients suivis dans le service d'hémato-oncopédiatrie ou en consultation de néphropédiatrie. Il s'agissait d'enfants à qui les parents ont donné ou voulu donner un ou des produits à base de plantes. Chaque préparation a bénéficié d'une analyse mycologique systématique. Résultats: Sur 42 produits analysés 40 étaient des compléments alimentaires dont 27 correspondaient à des préparations à base de plantes. Onze (28,2%) étaient positifs en culture pour Aspergillus (sp; niger; fumigatus), ou encore pour les genres Rhizopus, Zygosaccharomyces, Mucor ou Cladosporium. Ils avaient été majoritairement achetés en pharmacie et il y avait en moyenne 3,5 produits pris par enfant. Un cas d'un nourrisson de 7 mois s'était compliqué d'une péritonite aspergillaire. Discussion et conclusion: L'existence de champignons potentiellement pathogènes dans les préparations à base de plante entraîne un risque fongique réel chez l'immunodéprimé. Cette donnée doit conduire le clinicien à interroger systématiquement les parents sur un tel usage et à les informer sur les risques infectieux.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Impact of the process on dispersion and consequences on mechanical properties of polymers with embedded silica

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Impact of the process on dispersion and consequences on mechanical properties of polymers with embedded silica

International audienc

Dispersion control of raw and modified silica particles in PMMA. Impact on mechanical properties, from experiments to modelling

International audienceStructure and properties of PMMA/silica composites were characterized by various methods including SEM, TGA, rheology, microscopic level evaluation of nano-reinforcement effect on properties. Static modulus and yield strength of PMMA are enhanced with silica incorporation regardless of their dispersion or functionalization. However, composites ultimate properties are strongly affected by fillers characteristics. As expected, better performances are associated to well-dispersed and functionalized silica. A finite element modelling with interface debonding through cohesive model and interfacial area is introduced to reproduce the sensibility of tensile test response to fillers surface functionalization. Experimental results confirmed this modelling: at constant low weight rate, ultimate composites properties are mostly affected by any microstructural changes. An analysis of local stress confirms the premature breakage of composite with pristine silica. Finally, by considering the expected properties, functionalization of silica is not always a necessity. Instead of particle functionalization, a dispersion protocol could be advantageously used to reach interesting composite properties

Correlation between process and silica dispersion/distribution into composite: Impact on mechanical properties and Weibull statistical analysis

International audienceThe aim of this study is to propose a methodology for controlling and monitoring particle dispersion at each step of composite manufacturing. Composites with well and poor particle dispersion were manufactured and characterized by numerous methods to estimate the impact of different dispersion state on mechanical properties. An original: Weibull statistical analysis is suggested and shows the impact of this dispersion state on ultimate stress. For this purpose, a "model" matrix of PMMA was chosen. Well-dispersed silica enhanced Young's modulus by ∼9% and ultimate stress by ∼6%, while poorly-dispersed silica does not affect Young's modulus and ultimate stress. Moreover, a size effect is observed for well-dispersed composites; and not with poor particles dispersion

Mild head injury and attention deficit hyperactivity disorder in children

International audiencePurpose - Post-concussion syndrome is a well-described complication following moderate and severe head trauma but whether it occurs after mild head injury in children remains unclear. The aim of this study was to evaluate whether exposure to mild head injury with potential additional risk factors (non-surgical lesion on computed tomographic, high kinetic trauma, or Glasgow Coma Scale <15) is associated with attention deficit hyperactivity disorder (ADHD) after the head trauma. Methods - This study was performed in an emergency department on children admitted between 2009 and 2013. It compared victims of mild head injury aged 6-16 years with matched children presenting isolated non-surgical forearm fracture (ratio1/2). ADHD was assessed using Conners' Global Index-Parent short version 3-40 months after the trauma. The patients were compared using chi-square test or Fisher's exact test, t test or u-test as appropriate with a p value set at 0.05. Results - During the study period, 676 patients were admitted for mild head injury. Among them, 34 (5 %) fulfilled the inclusion criteria and were compared with 64 matched patients admitted for a forearm fracture. The groups were comparable. ADHD was observed in both groups (18 % in the mild head injury group, 11 % in the control group) with no significant differences between groups. The prevalence was high when compared to an expected frequency of 3.5-5.6 % in children aged 6-12 years in the general population. Conclusions - These results suggest that pre-existing ADHD may have contributed to injury proneness in both groups and does not argue for a specific risk of ADHD induced by mild head injury. The diagnosis of ADHD should be evoked at admission of children aged 6-16 years presenting with a trauma

Magnetic resonance imaging in children presenting migraine with aura: Association of hypoperfusion detected by arterial spin labelling and vasospasm on MR angiography findings.

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Grafting of graphene oxide with Ps, PMMA and PVAC for nanocomposite applications

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