Search results for "MATTER"
showing 10 items of 16762 documents
Structural hemispheric asymmetries underlie verbal Stroop performance
2017
Performance on tasks involving cognitive control such as the Stroop task is often associated with left lateralized brain activations. Based on this neuro-functional evidence, we tested whether leftward structural grey matter asymmetries would also predict inter-individual differences in combatting Stroop interference. To check for the specificity of the results, both a verbal Stroop task and a spatial one were administered to a total of 111 healthy young individuals, for whom T1-weighted magnetic resonance imaging (MRI) images were also acquired. Surface thickness and area estimations were calculated using FreeSurfer. Participants' hemispheres were registered to a symmetric template and Lat…
Temporal lobe grey matter volume in schizophrenia is associated with a genetic polymorphism influencing glycogen synthase kinase 3-beta activity
2010
At the crossroad of multiple pathways regulating trophism and metabolism, glycogen synthase kinase (GSK)3 is considered a key factor in influencing the susceptibility of neurons to harmful stimuli (neuronal resilience) and is a target for several psychiatric drugs that directly inhibit it or increase its inhibitory phosphorylation. Inhibition of GSK3 prevents apoptosis and could protect against the neuropathological processes associated with psychiatric disorders. A GSK3-beta promoter single-nucleotide polymorphism (rs334558) influences transcriptional strength, and the less active form was associated with less detrimental clinical features of mood disorders. Here we studied the effect of r…
Age–sex differences in the global burden of lower respiratory infections and risk factors, 1990–2019: results from the Global Burden of Disease Study…
2022
Funding: Bill & Melinda Gates Foundation. Background: The global burden of lower respiratory infections (LRIs) and corresponding risk factors in children older than 5 years and adults has not been studied as comprehensively as it has been in children younger than 5 years. We assessed the burden and trends of LRIs and risk factors across all age groups by sex, for 204 countries and territories. Methods: In this analysis of data for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we used clinician-diagnosed pneumonia or bronchiolitis as our case definition for LRIs. We included International Classification of Diseases 9th edition codes 079.6, 466–469, 470.0, 480–4…
Effects of Heat Waves on Mortality
2013
Heat waves and air pollution are both associated with increased mortality. Their joint effects are less well understood.We explored the role of air pollution in modifying the effects of heat waves on mortality, within the EuroHEAT project. Daily mortality, meteorologic, and air pollution data from nine European cities for the years 1990-2004 were assembled. We defined heat waves by taking both intensity and duration into account. The city-specific effects of heat wave episodes were estimated using generalized estimating equation models, adjusting for potential confounders with and without inclusion of air pollutants (particles, ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide). To …
Evidence of Wallerian degeneration in normal appearing white matter in the early stages of relapsing-remitting multiple sclerosis
2003
Objective: Wallerian degeneration in normal appearing white matter in early relapsing-remitting multiple sclerosis (RRMS), and its correlation with the number of relapses and disease duration. Background Recent pathological studies have demonstrated Wallerian degeneration in normal appearing white matter (NAWM) in multiple sclerosis (MS), in established RRMS, and in chronic MS. However, the presence of Wallerian degeneration early in the disease and its correlation with relapse and with disease duration has not been studied. Methods: We performed proton magnetic resonance spectroscopic imaging in 21 MS patients, and 4 healthy controls, age and gender matched, aged under 45 years, with a max…
Usefulness of quantitative peritumoural perfusion and proton spectroscopic magnetic resonance imaging evaluation in differentiating brain gliomas fro…
2016
Objectives The purpose of our study was to evaluate whether peritumoural perfusion weighted and proton spectroscopic magnetic resonance imaging can be used in differentiating between primary gliomas and solitary metastases. Methods Ten low-grade gliomas, eight high-grade gliomas and 10 metastases were prospectively evaluated with magnetic resonance imaging, dynamic susceptibility contrast enhanced perfusion imaging and single-voxel proton magnetic resonance spectroscopy before surgical resection or stereotactic biopsy. Maximal relative cerebral blood volume values were calculated drawing three regions of interest of 2 cm2 in the non-enhancing peritumoural areas. Maximal relative cerebral bl…
Automated segmentation of changes in FLAIR-hyperintense white matter lesions in multiple sclerosis on serial magnetic resonance imaging
2019
Longitudinal analysis of white matter lesion changes on serial MRI has become an important parameter to study diseases with white-matter lesions. Here, we build on earlier work on cross-sectional lesion segmentation; we present a fully automatic pipeline for serial analysis of FLAIR-hyperintense white matter lesions. Our algorithm requires three-dimensional gradient echo T1- and FLAIR- weighted images at 3 Tesla as well as available cross-sectional lesion segmentations of both time points. Preprocessing steps include lesion filling and intrasubject registration. For segmentation of lesion changes, initial lesion maps of different time points are fused; herein changes in intensity are analyz…
Quantification of Regional Intrapulmonary Oxygen Partial Pressure Evolution during Apnea by 3He MRI
1999
We present a new method to determine in vivo the temporal evolution of intrapulmonary oxygen concentrations by functional lung imaging with hyperpolarized (3)Helium ((3)He-->). Single-breath, single-bolus visualization of (3)He--> administered to the airspaces is used to analyze nuclear spin relaxation caused by the local oxygen partial pressure p(O(2))(t). We model the dynamics of hyperpolarization in the lung by rate equations. Based hereupon, a double acquisition technique is presented to separate depolarization by RF pulses and oxygen induced relaxation. It permits the determination of p(O(2)) with a high accuracy of up to 3% with simultaneous flip angle calibration using no additional …
Voxel based analyses of diffusion tensor imaging in Fabry disease
2007
Background: Fabry disease (FD) is a lysosomal storage disorder that is associated with marked cerebrovascular disease. Conventional MRI shows an extensive load of white matter lesions (WMLs) already at an early stage in FD. Objective: Investigator independent and sensitive quantification of brain structural changes in clinically affected men and women with FD. Methods: The authors performed a voxel-based analysis of diffusion tensor images (DTI) in 25 FD patients and 20 age-matched normal controls. Results: DTI revealed significant increases of cerebral white matter diffusivity (MD) in FD patients that were pronounced in the periventricular white matter. Even the subgroup of patients withou…
3T Double Inversion Recovery Magnetic Resonance Imaging: diagnostic advantages in the evaluation of cortical development anomalies
2016
Abstract Purpose The aim of this work was to investigate the diagnostic value of the DIR sequence at 3T MR imaging operating in the evaluation of cortical development anomalies. Methods We studied 40 patients, with a previous diagnosis of cortical dysplasia, by FLAIR-3D, DIR, FSE T2 and MPR-GE T1 sequences at 3T MRI. Two independent observers evaluated, for each sequence and lesion, some semiological aspects (cortical thickness, cortical signal intensity, white-gray matter blurring, subcortical white matter intensity). We made also a quantitative evaluation of the cortical signal intensity in lesion site, drawing a ROI on each MRI sequences and comparing them to the correspondent normal con…