ORCID Profile
0000-0002-0909-8900
Current Organisations
Hospices Civils de Lyon
,
Bangladesh Agricultural University
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Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2013
DOI: 10.1212/01.WNL.0000436611.28210.EC
Abstract: We focused on cerebral imaging findings in a large cohort of young patients with a symptomatic ischemic cerebrovascular event (CVE) to extract relevant pathophysiologic and clinical information. We analyzed the scans of 2,979 patients (aged 18-55 years) enrolled in the sifap1 project with clinical evidence of ischemic stroke (IS) or clinically defined TIA in whom MRI, including diffusion-weighted imaging, was obtained within 10 days of the CVE. Age groups were categorized as 18-34, 35-44, and 45-55 years. We compared age- and sex-specific proportions of infarct features, white matter hyperintensities, and old microbleeds. Acute infarcts were identified in 1,914 of 2,264 patients (84.5%) with IS and 101 of 715 patients (14.1%) with TIA. Among patients with IS, younger age was significantly associated with acute infarcts in the posterior circulation, while anterior circulation infarcts and acute lacunar infarcts were more frequent in older age groups. One or more old infarcts were present in 26.8% of IS and 17.1% of TIA patients. This rate remained high even after excluding patients with a prior CVE (IS, 21.7% TIA, 9.9%). The prevailing type of old infarction was territorial in patients younger than 45 years and lacunar in those aged 45 years or older. The frequency of white matter hyperintensities (46.4%) and their severity was positively associated with age. Old microbleeds were infrequent (7.2%). Young adults show a high frequency of preexisting and clinically silent infarcts and a relative preference for acute ischemia in the posterior circulation. Findings suggesting small-vessel disease become apparent at age 45 years and older.
Publisher: Massachusetts Medical Society
Date: 16-08-2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
DOI: 10.1161/STROKEAHA.114.008548
Abstract: Fabry disease (FD) may cause stroke and is reportedly associated with typical brain findings on magnetic resonance imaging (MRI). In a large group of young patients with an acute cerebrovascular event, we wanted to test whether brain MRI findings can serve to suggest the presence of FD. The Stroke in Young Fabry Patients (SIFAP 1) study prospectively collected clinical, laboratory, and radiological data of 5023 patients (18–55 years) with an acute cerebrovascular event. Their MRI was interpreted centrally and blinded to all other information. Biochemical findings and genetic testing served to diagnose FD in 45 (0.9%) patients. We compared the imaging findings between FD and non-FD patients in patients with at least a T2-weighted MRI of good quality. A total of 3203 (63.8%) patients had the required MRI data set. Among those were 34 patients with a diagnosis of FD (1.1%), which was definite in 21 and probable in 13 cases. The median age of patients with FD was slightly lower (45 versus 46 years) and women prevailed (70.6% versus 40.7% P .001). Presence or extent of white matter hyperintensities, infarct localization, vertebrobasilar artery dilatation, T1-signal hyperintensity of the pulvinar thalami, or any other MRI finding did not distinguish patients with FD from non-FD cerebrovascular event patients. Pulvinar hyperintensity was not present in a single patient with FD but seen in 6 non-FD patients. Brain MRI findings cannot serve to suspect FD in young patients presenting with an acute cerebrovascular event. This deserves consideration in the search for possible causes of young patients with stroke. URL: www.clinicaltrials.gov . Unique identifier: NCT00414583.
Publisher: Elsevier BV
Date: 2019
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2020
DOI: 10.1161/STROKEAHA.119.027390
Abstract: Relative signal intensity of acute ischemic stroke lesions in fluid-attenuated inversion recovery (fluid-attenuated inversion recovery relative signal intensity [FLAIR-rSI]) magnetic resonance imaging is associated with time elapsed since stroke onset with higher intensities signifying longer time intervals. In the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke Trial), intravenous alteplase was effective in patients with unknown onset stroke selected by visual assessment of diffusion weighted imaging fluid-attenuated inversion recovery mismatch, that is, in those with no marked fluid-attenuated inversion recovery hyperintensity in the region of the acute diffusion weighted imaging lesion. In this post hoc analysis, we investigated whether quantitatively measured FLAIR-rSI modifies treatment effect of intravenous alteplase. FLAIR-rSI of stroke lesions was measured relative to signal intensity in a mirrored region in the contralesional hemisphere. The relationship between FLAIR-rSI and treatment effect on functional outcome assessed by the modified Rankin Scale (mRS) after 90 days was analyzed by binary logistic regression using different end points, that is, favorable outcome defined as mRS score of 0 to 1, independent outcome defined as mRS score of 0 to 2, ordinal analysis of mRS scores (shift analysis). All models were adjusted for National Institutes of Health Stroke Scale at symptom onset and stroke lesion volume. FLAIR-rSI was successfully quantified in stroke lesions in 433 patients (86% of 503 patients included in WAKE-UP). Mean FLAIR-rSI was 1.06 (SD, 0.09). Interaction of FLAIR-rSI and treatment effect was not significant for mRS score of 0 to 1 ( P =0.169) and shift analysis ( P =0.086) but reached significance for mRS score of 0 to 2 ( P =0.004). We observed a smooth continuing trend of decreasing treatment effects in relation to clinical end points with increasing FLAIR-rSI. In patients in whom no marked parenchymal fluid-attenuated inversion recovery hyperintensity was detected by visual judgement in the WAKE-UP trial, higher FLAIR-rSI of diffusion weighted imaging lesions was associated with decreased treatment effects of intravenous thrombolysis. This parallels the known association of treatment effect and elapsing time of stroke onset.
Publisher: Massachusetts Medical Society
Date: 19-07-2018
Publisher: Frontiers Media SA
Date: 13-01-2021
DOI: 10.3389/FSUFS.2020.609788
Abstract: Organic waste streams, otherwise known as organic amendments (OA), contain potentially valuable nutrients which may additionally increase legacy nutrient availability in soil. This is particularly the case for phosphorus (P) where declining reserves of rock phosphate add an extra dimension to their utility. In acidic soils, OA have been reported to increase P availability through the action of O-aryl and carbonyl groups (represent organic acid compounds) by substituting previously fixed, legacy P and forming organometallic complexes to reduce P sorption. This study aimed to investigate if signature P (orthophosphate) and C (O-aryl and carbonyl) content of OA could be used to predict soil P availability, to replace traditional ways of testing OA and also for future prescriptive applications. Food waste and biosolid were the sources of OA in this study, with pyrolysis and composting processes used to create a range of functional groups. Nuclear magnetic resonance (NMR) spectroscopy was utilized to identify forms of C (solid-state 13 C NMR) and P compounds (solution-state 31 P NMR) in these OA. The O-aryl, carbonyl, and orthophosphate content were higher in pyrolysis and composted materials compared to their feedstock substrate. The effect of OA addition on soil P availability was monitored in a 110-day laboratory incubation study. Results showed an increase in soil P availability (Olsen P) and a decrease in soil P buffering capacity (PBC) after incubation. The increase in soil P availability was not predicted well by the NMR-derived orthophosphate content of OA, which may be due to the overestimation of plant-available orthophosphate content by the solution-state 31 P NMR. Furthermore, an additional increase in soil ΔOlsen P (difference between observed and expected) was obtained above the Olsen P added from OA indicating substitution of previously fixed soil P. Both indices of P availability namely ΔOlsen P ( r = 0.63–0.83) and ΔPBC (difference between treatment—control) ( r = −0.50 to −0.80) showed strong (but opposite) correlations with the ratio of O-aryl to carbonyl C content of OA. It was concluded that the ratio of O-aryl and carbonyl C content of OA could be used to predict the P availability in acidic soil.
No related grants have been discovered for Laurent Derex.