Algorithmes flous : Application à la quantification du tissu adipeux en IRM abdominale

Le syndrome métabolique, associé à l'obésité est une pathologie en forte progression dans nos sociétés occidentales. Un marqueur jouant un rôle prépondérant dans le diagnostic de cette pathologie est le tour de taille, dépendant de la graisse viscérale et sous-cutanée. Nous proposons dans cet article une méthode automatique et fiable de segmentation des graisses viscérale et sous-cutanée utilisant succéssivement un algorithme de classification floue suivi d'un algorithme de connectivité nous permettant de nous affranchir des problèmes d'inhomogénéités du tissu adipeux et du champs magnétique

A comparison between early presentation of dementia with Lewy Bodies, Alzheimer's disease and Parkinson's disease: evidence from routine primary care and UK Biobank data

OBJECTIVE: To simultaneously contrast prediagnostic clinical characteristics of individuals with a final diagnosis of dementia with Lewy Bodies, Parkinson's disease, Alzheimer's disease compared to controls without neurodegenerative disorders. METHODS: Using the longitudinal THIN database in the UK, we tested the association of each neurodegenerative disorder with a selected list of symptoms and broad families of treatments, and compared the associations between disorders to detect disease-specific effects. We replicated the main findings in the UK Biobank. RESULTS: We used data of 28,222 patients with PD, 20,214 with AD, 4,682 with DLB and 20,214 controls. All neurodegenerative disorders were significantly associated with the presence of multiple clinical characteristics before their diagnosis including sleep disorders, falls, psychiatric symptoms and autonomic dysfunctions. When comparing DLB patients with patients with PD and AD patients, falls, psychiatric symptoms and autonomic dysfunction were all more strongly associated with DLB in the five years preceding the first neurodegenerative diagnosis. The use of statins was lower in patients who developed PD and higher in patients who developed DLB compared to AD. In PD patients, the use of statins was associated with the development of dementia in the five years following PD diagnosis. INTERPRETATION: Prediagnostic presentations of falls, psychiatric symptoms and autonomic dysfunctions were more strongly associated with DLB than PD and AD. This study also suggests that whilst several associations with medications are similar in neurodegenerative disorders, statin usage is negatively associated with Parkinson's Disease but positively with DLB and AD as well as development of dementia in PD

Microbial Communities of the Shallow-Water Hydrothermal Vent Near Naples, Italy, and Chemosynthetic Symbionts Associated With a Free-Living Marine Nematode

Shallow-water hydrothermal vents are widespread, especially in the Mediterranean Sea, owing to the active volcanism of the area. Apart free microbial communities’ investigations, few biological studies have been leaded yet. Investigations of microbial communities associated with Nematoda, an ecologically important group in sediments, can help to improve our overall understanding of these ecosystems. We used a multidisciplinary-approach, based on microscopic observations (scanning electron microscopy: SEM and Fluorescence In Situ Hybridization: FISH) coupled with a molecular diversity analysis using metabarcoding, based on the 16S rRNA gene (V3-V4 region), to characterize the bacterial community of a free-living marine nematode and its environment, the shallow hydrothermal vent near Naples (Italy). Observations of living bacteria in the intestine (FISH), molecular and phylogenetic analyses showed that this species of nematode harbors its own bacterial community, distinct from the surrounding sediment and water. Metabarcoding results revealed the specific microbiomes of the sediment from three sites of this hydrothermal area to be composed mainly of sulfur oxidizing and reducing related bacteria

Quantification de la stéatose hépatique par IRM chez le rat

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Apport de l'imagerie à l'évaluation de la fibrose hépatique

La prévalence et la gravité des complications de la cirrhose hépatique nécessitent de disposer d'une méthode de dépistage et de diagnostic non invasif. Les techniques d'imagerie ont l'avantage d'associer un bilan morphologique à l'évaluation de la fibrose. Ce travail et les données de la littérature s'accordent pour situer les performances diagnostiques (PD) de ces techniques au-delà de 80 % pour le diagnostic de cirrhose. Dans notre étude clinique, l'échographie Doppler avait une PD de 92 % pour le diagnostic de cirrhose. Mais, sa performance était plus faible pour la détection et la classification de la fibrose hépatique. Dans une approche plus quantitative en IRM, le temps de relaxation était bien corrélé (r=0,78) à l'aire de fibrose chez le rat, mais ces résultats était modèle dépendant. D'autres techniques d'imagerie radiologique sont à l'étude : l'imagerie de diffusion dont nous rapportons notre étude préliminaire, la perfusion hépatique, l'élastographie et l'analyse de texture.The prevalence and the morbidity of complications of cirrhosis justify the implementation of non invasive diagnosis and screening means. Imaging techniques have a major advantage: the realization in the same examination of fibrosis evaluation and morphological study. This work and the studies published in the literature agree on an interesting diagnostic accuracy (DA) of these techniques, superior to 80% for the diagnosis of cirrhosis. In our clinical study DA of ultrasound was 92% for the diagnosis of cirrhosis. But its accuracies were lower for the detection and classification of hepatic fibrosis. In a more quantitative way using MRI, relaxation time was well correlated (r=0.78) to the area of fibrosis in rat, but these results were depended of the model. Some radiological methods are in progress: diffusion weighted MRI that we report our preliminary study, hepatic perfusion, elastography and texture analysis.ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Faisabilité et premiers résultats du coloscanner à l'eau

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

ETUDE MORPHOLOGIQUE ET FONCTIONNELLE DES ANASTOMOSES PANCREATICOGASTRIQUES EN CPIRM AVEC INJECTION DE SECRETINE (DES RADIODIAGNOSTIC ET IMAGERIE MEDICALE)

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

INTERET DE L'IRM DE DIFFUSION DANS LE DIAGNOSTIC NON INVASIF DE LA CIRRHOSE HEPATIQUE

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Facteurs prédictifs radiologiques de récidive des lésions hépatiques traitées par radiofréquence

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Sémiologie dynamique des masses focales hépatiques en échographie de contraste (Atlas sur support CD-ROM)

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF