4,859 research outputs found

    Phenoconversion from probable rapid eye movement sleep behavior disorder to mild cognitive impairment to dementia in a population-based sample

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    © 2017 The Authors Introduction Rapid eye movement sleep behavior disorder (RBD) is strongly associated with synucleinopathies. In 2012, we reported an increased risk of mild cognitive impairment (MCI) and Parkinson disease (PD) in cognitively normal Olmsted County, Minnesota, residents, aged 70 to 89 years with probable RBD. Here, we examine their progression to dementia and other neurodegenerative phenotypes. Methods Fifteen participants with RBD who were diagnosed with either MCI or PD were longitudinally followed, and their subsequent clinical courses were reviewed. Results Over 6.4 ± 2.9 years, six of the 14 participants with MCI developed additional neurodegenerative signs, five of whom had Lewy body disease features. Four of them progressed to dementia at a mean age 84.8 ± 4.9 years, three of whom met the criteria for probable dementia with Lewy bodies. One subject with PD developed MCI, but not dementia. Discussion Our findings from the population-based sample of Olmsted County, Minnesota, residents suggest that a substantial number of RBD patients tend to develop overt synucleinopathy features over time, and RBD patients who develop MCI and subsequent dementia have clinical features most consistent with dementia with Lewy bodies

    Le sentiment d’appartenance à l’école : une analyse conceptuelle

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    Le sentiment d’appartenance à l’école est considéré comme un phénomène qui favorise la réussite scolaire et l’adaptation des jeunes à l’école. Malgré son importance, les études ne permettent pas d’en arriver à une représentation conceptuelle exhaustive de ce concept. Cet article vise à identifier les attributs définitionnels du sentiment d’appartenance à l’école dans le but de favoriser sa compréhension. La méthode conceptuelle privilégiée est celle de Walker et Avant (2011) qui comporte huit étapes distinctes permettant de mener un tel examen. La revue de la documentation a été menée par le biais de moteurs de recherche généralistes (p. ex. : Google, Google Scholar) et spécialisés (p. ex. : PsyInfo, Eric, Francis) en considérant les définitions en langues anglaise et française. En se basant sur l’analyse conceptuelle ayant été menée, quatre attributs définitionnels sont suggérés. L’élève doit : (1) ressentir une émotion positive à l’égard du milieu scolaire ; (2) entretenir des relations sociales positives avec les membres du milieu scolaire ; (3) s’impliquer activement dans les activités de la classe ou celles de l’école ; (4) percevoir une certaine synergie (harmonisation), voire une similarité, avec les membres de son groupe. En plus d’être abordés dans la perspective des principaux modèles théoriques en sciences de l’éducation qui tiennent compte du sentiment d’appartenance à l’école, ces attributs ont donné lieu à l’élaboration d’une nouvelle définition que nous présentons dans le présent article

    Towards novel difluorinated sugar mimetrics; syntheses and conformational analyses of highly-functionalised difluorinated cyclooctenones

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    Highly-functionalised difluorinated cyclooctenones were synthesised from trifluoroethanol using either metallated difluoroenol acetal or carbamate chemistry, followed by a [2,3]-Wittig rearrangement or aldol reaction. Efficient RCM reactions afforded the title compounds which showed rather restricted fluxional behaviour by VT 19F NMR. Topological characterisation by molecular modelling and NOESY/ROESY experiments offered a number of challenges, but allowed the identification of two favoured boat-chair conformers which interconverted by pseudorotation with relatively large activation barriers

    Adenocarcinoma Arising in Gastric Heterotopic Pancreas: A Case Report

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    A heterotopic pancreas in the gastrointestinal tract is mostly found incidentally and its malignant transformation is extremely rare. We describe the second case of adenocarcinoma arising in a gastric heterotopic pancreas of an asymptomatic 35-yr-old man in Korea. Esophagogastroduodenoscopy revealed a submucosal tumor with an irregular central umbilication in the gastric antrum. A wedge resection specimen demonstrated a submucosal oligolocular cystic mass (1.7×1.4×1.2 cm) with a solid portion. Microscopically, the cystic portion was composed of dilated pancreaticobiliary type ducts with adjacent small foci of periductal glandular structures. The adenocarcinoma components in the solid area infiltrated the proper muscle and the overlying mucosa of the stomach. The transitional area between the benign ductal structures and the adenocarcinoma component was found. The follow-up course was uneventful 5 months postoperatively

    Detection of micrometastasis by cytokeratin 20 RT-PCR is limited due to stable background transcription in granulocytes

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    The reverse transcription polymerase chain reaction (RT-PCR) amplification of cytokeratin 20 (CK20) mRNA is considered a promising candidate method for the detection of circulating tumour cells in bone marrow and peripheral blood of cancer patients. In this study we have investigated the diagnostic specificity of the CK20 mRNA detection in samples from healthy donors (HD; n = 33), intensive care units patients (ICU; n = 20) and bone marrow obtained from patients suffering from chronic inflammatory diseases (CID; n = 14). RNAs purified from stabilized lysates showed positive results in 24% of the HD group (8/33), 35% of the ICU group (8/20) and in 40% of the CID group (5/14). The use of Ficoll gradients to separate nucleated cells completely restored the specificity of this CK20 RT-PCR assay. The CK20-expressing cells are positively identified to belong to the granulocyte fraction of leucocytes, which appear to express the gene on a background level. Our results demonstrate for the first time that CK20 mRNA expression is not limited to epithelium. Its occurrence in normal granulocytes has to be considered in tests designed to detect circulating cancer cells or micrometastases. © 1999 Cancer Research Campaig

    A novel method to analyze leukocyte rolling behavior in vivo

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    Leukocyte endothelial cell interaction is a fundamentally important process in many disease states. Current methods to analyze such interactions include the parallel-plate flow chamber and intravital microscopy. Here, we present an improvement of the traditional intravital microscopy that allows leukocyte-endothelial cell interaction to be studied from the time the leukocyte makes its initial contact with the endothelium until it adheres to or detaches from the endothelium. The leukocyte is tracked throughout the venular tree with the aid of a motorized stage and the rolling and adhesive behavior is measured off-line. Because this method can involve human error, methods to automate the tracking procedure have been developed. This novel tracking method allows for a more detailed examination of leukocyte-endothelial cell interactions
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