Échanges et circulation des textes dans l’espace littéraire mondial

Pascale Casanova Partant de la description de la structure et du fonctionnement de l’espace littéraire international, le séminaire a porté principalement, d’une part sur la question de la constitution et de la légitimation de la valeur littéraire et d’autre part sur l’hypothèse de l’établissement d’une « grammaire » des choix littéraires dans les zones les plus dépendantes de l’espace littéraire. C’est notamment à partir de la traduction considérée à la fois comme échange inégal, voie d’accum..

Cholinergic white matter pathways along the Alzheimer's disease continuum

Nemy et al. investigate cholinergic white matter projections along the Alzheimer's disease continuum. They show that alterations are already present in individuals with subjective cognitive decline, preceding the more widespread alterations seen in mild cognitive impairment and Alzheimer's disease dementia. Previous studies have shown that the cholinergic nucleus basalis of Meynert and its white matter projections are affected in Alzheimer's disease dementia and mild cognitive impairment. However, it is still unknown whether these alterations can be found in individuals with subjective cognitive decline, and whether they are more pronounced than changes found in conventional brain volumetric measurements. To address these questions, we investigated microstructural alterations of two major cholinergic pathways in individuals along the Alzheimer's disease continuum using an in vivo model of the human cholinergic system based on neuroimaging. We included 402 participants (52 Alzheimer's disease, 66 mild cognitive impairment, 172 subjective cognitive decline and 112 healthy controls) from the Deutsches Zentrum für Neurodegenerative Erkrankungen Longitudinal Cognitive Impairment and Dementia Study. We modelled the cholinergic white matter pathways with an enhanced diffusion neuroimaging pipeline that included probabilistic fibre-tracking methods and prior anatomical knowledge. The integrity of the cholinergic white matter pathways was compared between stages of the Alzheimer's disease continuum, in the whole cohort and in a CSF amyloid-beta stratified subsample. The discriminative power of the integrity of the pathways was compared to the conventional volumetric measures of hippocampus and nucleus basalis of Meynert, using a receiver operating characteristics analysis. A multivariate model was used to investigate the role of these pathways in relation to cognitive performance. We found that the integrity of the cholinergic white matter pathways was significantly reduced in all stages of the Alzheimer's disease continuum, including individuals with subjective cognitive decline. The differences involved posterior cholinergic white matter in the subjective cognitive decline stage and extended to anterior frontal white matter in mild cognitive impairment and Alzheimer's disease dementia stages. Both cholinergic pathways and conventional volumetric measures showed higher predictive power in the more advanced stages of the disease, i.e. mild cognitive impairment and Alzheimer's disease dementia. In contrast, the integrity of cholinergic pathways was more informative in distinguishing subjective cognitive decline from healthy controls, as compared with the volumetric measures. The multivariate model revealed a moderate contribution of the cholinergic white matter pathways but not of volumetric measures towards memory tests in the subjective cognitive decline and mild cognitive impairment stages. In conclusion, we demonstrated that cholinergic white matter pathways are altered already in subjective cognitive decline individuals, preceding the more widespread alterations found in mild cognitive impairment and Alzheimer's disease. The integrity of the cholinergic pathways identified the early stages of Alzheimer's disease better than conventional volumetric measures such as hippocampal volume or volume of cholinergic nucleus basalis of Meynert

First-Trimester Screening for Gestational Diabetes Mellitus in Twin Pregnancies

We previously reported a logistic regression model for prediction of GDM from maternal characteristics and medical history in 75,161 singleton pregnancies. In this study of 1376 twin and 13,760 singleton pregnancies recruited at 11–13 weeks’ gestation, we extend the model to include terms for twin pregnancies. We found the respective odds of GDM in dichorionic and monochorionic twin pregnancies to be 1.36 (95% CI: 1.02–1.81) and 2.78 (95% CI: 1.72–4.48) times higher than in singleton pregnancies. In both singleton and twin pregnancies, the risk for GDM increased with maternal age and weight and birth weight z-score of a baby in a previous pregnancy and is higher in women with a previous pregnancy complicated by GDM; in those with a first- or second-degree relative with diabetes mellitus; in women of Black, East Asian, and South Asian racial origin; and in pregnancies conceived through the use of ovulation-induction drugs. In singleton pregnancies, at 10% and 20% false-positive rate, the detection rate was 43% and 58%, respectively. In twin pregnancies, using risk cut-offs corresponding to 10% and 20% false-positive rates in singletons, the respective false-positive rates were 27% and 47%, and the detection rates were 63% and 81%

Prediction of Alzheimer's Disease Using Midregional Proadrenomedullin and Midregional Proatrial Natriuretic Peptide: A Retrospective Analysis of 134 Patients With Mild Cognitive Impairment

Objective: Development of biomarkers for early detection of Alzheimer's disease (AD) is a major clinical research goal. On the basis of the hypothesis that cardiovascular risk factors contribute to the pathogenesis of AD, we investigated whether the cardiovascular risk markers midregional proadrenomedullin (MR-proADM) and midregional proatrial natriuretic peptide (MR-proANP) predict a major clinical milestone, ie, conversion from predementia mild cognitive impairment (MCI) to manifest AD. Method: A group of 134 MCI patients, among 137 originally prospectively recruited at the memory disorder clinic at Malmo University Hospital, Malmo, Sweden, between July 1998 and June 2001, was clinically followed for 4-6 years. We determined whether plasma concentrations of MR-proADM and MR-proANP at baseline predicted time to conversion from MCI to clinically diagnosed AD (DSM-III-R). MCI was diagnosed according to Petersen criteria. Results: During follow-up, 41.8% of MCI patients remained cognitively stable, 42.5% converted to possible and probable AD, and 15.7% converted to other forms of dementia (MCI-other). MCI converters and MCI-other patients showed increased concentrations of MR-proANP and MR-proADM compared to the stable MCI patients (P=.0001). At a cutoff of 87 pmol/L, MR-proANP yielded a sensitivity of 73.7% and a specificity of 64.3% for predicting conversion to All. The survival analysis showed that higher values of MR-proANP and MR-proADM were associated with progression to AD. In a multivariate Cox regression model including known risk factors, MR-proANP and MR-proADM remained independent risk factors for conversion to AD for patients below the age of 72 years. Conclusions: Our study shows that plasma concentrations of MR-proANP and MR-proADM have predictive value in the progression from predementia MCI to clinical AD. Sensitivity was particularly high, which may recommend this test for first-stage screening in patients at risk for AD. J Clin Psychiatry 2011;72(4): 556-563 (C) Copyright 2010 Physicians Postgraduate Press, Inc

Long-term environmental enrichment is associated with better fornix microstructure in older adults

Background Sustained environmental enrichment (EE) through a variety of leisure activities may decrease the risk of developing Alzheimer’s disease. This cross-sectional cohort study investigated the association between long-term EE in young adulthood through middle life and microstructure of fiber tracts associated with the memory system in older adults. Methods N = 201 cognitively unimpaired participants (≥ 60 years of age) from the DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE) baseline cohort were included. Two groups of participants with higher ( n = 104) or lower ( n = 97) long-term EE were identified, using the self-reported frequency of diverse physical, intellectual, and social leisure activities between the ages 13 to 65. White matter (WM) microstructure was measured by fractional anisotropy (FA) and mean diffusivity (MD) in the fornix, uncinate fasciculus, and parahippocampal cingulum using diffusion tensor imaging. Long-term EE groups (lower/higher) were compared with adjustment for potential confounders, such as education, crystallized intelligence, and socio-economic status. Results Reported participation in higher long-term EE was associated with greater fornix microstructure, as indicated by higher FA (standardized β = 0.117, p = 0.033) and lower MD (β = −0.147, p = 0.015). Greater fornix microstructure was indirectly associated (FA: unstandardized B = 0.619, p = 0.038; MD: B = −0.035, p = 0.026) with better memory function through higher long-term EE. No significant effects were found for the other WM tracts. Conclusion Our findings suggest that sustained participation in a greater variety of leisure activities relates to preserved WM microstructure in the memory system in older adults. This could be facilitated by the multimodal stimulation associated with the engagement in a physically, intellectually, and socially enriched lifestyle. Longitudinal studies will be needed to support this assumption

Antihypertensive Therapy Is Associated with Reduced Rate of Conversion to Alzheimer's Disease in Midregional Proatrial Natriuretic Peptide Stratified Subjects with Mild Cognitive Impairment

Background: Hypertension is a major risk factor of Alzheimer's disease (AD); however, controlled studies on the effect of antihypertensive treatment on the risk of dementia are inconclusive. Therefore, a biological marker that predicts individual response to antihypertensive treatment would be of high clinical relevance. Midregional proatrial natriuretic peptide (MR-proANP), an inactive surrogate molecule of the mature atrial natriuretic peptide, is related to circulatory function and hypertension. Methods: A sample population of 134 subjects with mild cognitive impairment (MCI) was followed for up to 6 years. Multivariable Cox regression analysis was conducted to predict conversion to AD based on all relevant variables. Results: Baseline MR-proANP was significantly increased in the AD converter group (p 74 pmol/L. Further subgrouping by age (>/<= 72 years at baseline) increased the positive correlation of antihypertensive treatment and MCI outcome for patients below the age of 72 years (conversion rate reduced by 74%, p = .016). Conclusions: These data seem to support the notion of a potential impact of circulatory function for the prognosis of AD at a prodromal stage. The MR-proANP levels may be useful to predict the effect of antihypertensive treatment on conversion rates to AD in subjects with MCI

Cholinergic white matter pathways along the Alzheimer's disease continuum

Nemy et al. investigate cholinergic white matter projections along the Alzheimer's disease continuum. They show that alterations are already present in individuals with subjective cognitive decline, preceding the more widespread alterations seen in mild cognitive impairment and Alzheimer's disease dementia. Previous studies have shown that the cholinergic nucleus basalis of Meynert and its white matter projections are affected in Alzheimer's disease dementia and mild cognitive impairment. However, it is still unknown whether these alterations can be found in individuals with subjective cognitive decline, and whether they are more pronounced than changes found in conventional brain volumetric measurements. To address these questions, we investigated microstructural alterations of two major cholinergic pathways in individuals along the Alzheimer's disease continuum using an in vivo model of the human cholinergic system based on neuroimaging. We included 402 participants (52 Alzheimer's disease, 66 mild cognitive impairment, 172 subjective cognitive decline and 112 healthy controls) from the Deutsches Zentrum fur Neurodegenerative Erkrankungen Longitudinal Cognitive Impairment and Dementia Study. We modelled the cholinergic white matter pathways with an enhanced diffusion neuroimaging pipeline that included probabilistic fibre-tracking methods and prior anatomical knowledge. The integrity of the cholinergic white matter pathways was compared between stages of the Alzheimer's disease continuum, in the whole cohort and in a CSF amyloid-beta stratified subsample. The discriminative power of the integrity of the pathways was compared to the conventional volumetric measures of hippocampus and nucleus basalis of Meynert, using a receiver operating characteristics analysis. A multivariate model was used to investigate the role of these pathways in relation to cognitive performance. We found that the integrity of the cholinergic white matter pathways was significantly reduced in all stages of the Alzheimer's disease continuum, including individuals with subjective cognitive decline. The differences involved posterior cholinergic white matter in the subjective cognitive decline stage and extended to anterior frontal white matter in mild cognitive impairment and Alzheimer's disease dementia stages. Both cholinergic pathways and conventional volumetric measures showed higher predictive power in the more advanced stages of the disease, i.e. mild cognitive impairment and Alzheimer's disease dementia. In contrast, the integrity of cholinergic pathways was more informative in distinguishing subjective cognitive decline from healthy controls, as compared with the volumetric measures. The multivariate model revealed a moderate contribution of the cholinergic white matter pathways but not of volumetric measures towards memory tests in the subjective cognitive decline and mild cognitive impairment stages. In conclusion, we demonstrated that cholinergic white matter pathways are altered already in subjective cognitive decline individuals, preceding the more widespread alterations found in mild cognitive impairment and Alzheimer's disease. The integrity of the cholinergic pathways identified the early stages of Alzheimer's disease better than conventional volumetric measures such as hippocampal volume or volume of cholinergic nucleus basalis of Meynert

TRY plant trait database - enhanced coverage and open access

10.1111/gcb.14904GLOBAL CHANGE BIOLOGY261119-18