Cyclotron Research Center
Cyclotron Research Center
Martin C.,University of Liège |
Letellier C.,Coda Research |
Caij B.,Coda Research |
Gauthier D.,British Petroleum |
And 3 more authors.
Veterinary Microbiology | Year: 2011
Inter-species transmission is often incriminated in the epidemiology of Pestivirus diseases. The purpose of this study was to investigate the prevalence of Pestivirus in some mountain wild ungulates and to determine their role in Pestivirus transmission, as mountain pastures are a place where cohabitations between wild and domestic ungulates are particularly high. Between 2003 and 2007, a longitudinal epidemiological study was carried out on hunted ungulates in the French Hautes-Alpes department. Pestivirus-specific antibodies against p80 protein (also named NS3) common to all Bovine Viral Diarrhea Virus (BVDV) and Border Disease Virus (BDV) were found in 45.9% (95% confidence interval [CI95%]: 40.5-51.3%) of the 343 tested chamois (Rupicapra rupicapra). In addition, mouflons (Ovis gmelinii musimon) were shown for the first time to be strongly infected (61.1%; CI95%: 38.6-83.6) by a Pestivirus. These serological ELISA results were confirmed by comparative virus neutralization tests, performed on seven Pestivirus strains by using 15 seropositive samples. The highest antibody titers were directed against 2 BDV strains (Av and 33s strains), rather than BDV-4, a strain responsible for Pyrenean-chamois epizooties. Virus neutralization tests confirm a BDV circulation in wild ungulates in the French South Alps. However, no Pestivirus RNA was detected by reverse-transcriptase polymerase chain reaction in serum and spleen samples from seronegative animals and no virus was isolated from those samples either. Efforts should be made to improve the protocol in order to be able to isolate and characterize the local strain. Finally, the oldness (age) and femaleness (gender) increase the risk of seroconversion in chamois. © 2010 Elsevier B.V.
Galanaud D.,University Pierre and Marie Curie |
Perlbarg V.,University Pierre and Marie Curie |
Gupta R.,Massachusetts General Hospital |
Stevens R.D.,Johns Hopkins University |
And 18 more authors.
Anesthesiology | Year: 2012
BACKGROUND:: Existing methods to predict recovery after severe traumatic brain injury lack accuracy. The aim of this study is to determine the prognostic value of quantitative diffusion tensor imaging (DTI). METHODS:: In a multicenter study, the authors prospectively enrolled 105 patients who remained comatose at least 7 days after traumatic brain injury. Patients underwent brain magnetic resonance imaging, including DTI in 20 preselected white matter tracts. Patients were evaluated at 1 yr with a modified Glasgow Outcome Scale. A composite DTI score was constructed for outcome prognostication on this training database and then validated on an independent database (n = 38). DTI score was compared with the International Mission for Prognosis and Analysis of Clinical Trials Score. RESULTS:: Using the DTI score for prediction of unfavorable outcome on the training database, the area under the receiver operating characteristic curve was 0.84 (95% CI: 0.75-0.91). The DTI score had a sensitivity of 64% and a specificity of 95% for the prediction of unfavorable outcome. On the validation-independent database, the area under the receiver operating characteristic curve was 0.80 (95% CI: 0.54-0.94). On the training database, reclassification methods showed significant improvement of classification accuracy (P < 0.05) compared with the International Mission for Prognosis and Analysis of Clinical Trials score. Similar results were observed on the validation database. CONCLUSIONS:: White matter assessment with quantitative DTI increases the accuracy of long-term outcome prediction compared with the available clinical/radiographic prognostic score. © 2012, the American Society of Anesthesiologists, Inc.
PubMed | Cyclotron Research Center and University of Liège
Type: Journal Article | Journal: Cerebral cortex (New York, N.Y. : 1991) | Year: 2016
Genetic variability related to the catechol-O-methyltransferase (COMT) gene (Val(158)Met) has received increasing attention as a possible modulator of executive functioning and its neural correlates. However, this attention has generally centered on the prefrontal cortices because of the well-known direct impact of COMT enzyme on these cerebral regions. In this study, we were interested in the modulating effect of COMT genotype on anterior and posterior brain areas underlying interference resolution during a Stroop task. More specifically, we were interested in the functional connectivity between the right inferior frontal operculum (IFop), an area frequently associated with inhibitory efficiency, and posterior brain regions involved in reading/naming processes (the 2 main non-executive determinants of the Stroop effect). The Stroop task was administered during functional magnetic resonance imaging scanning to 3 groups of 15 young adults divided according to their COMT Val(158)Met genotype [Val/Val (VV), Val/Met (VM), and Met/Met (MM)]. Results indicate greater activity in the right IFop and the left middle temporal gyrus in homozygous VV individuals than in Met allele carriers. In addition, the VV group exhibited stronger positive functional connectivity between these 2 brain regions and stronger negative connectivity between the right IFop and left lingual gyrus. These results confirm the impact of COMT genotype on frontal functions. They also strongly suggest that differences in frontal activity influence posterior brain regions related to a non-executive component of the task. Particularly, changes in functional connectivity between anterior and posterior brain areas might correspond to compensatory processes for performing the task efficiently when the available dopamine level is low.
Jaspar M.,Cyclotron Research Center |
Manard M.,Cyclotron Research Center |
Manard M.,University of Liège |
DIdeberg V.,University of Liège |
And 3 more authors.
Cerebral Cortex | Year: 2016
Genetic variability related to the catechol-O-methyltransferase (COMT) gene (Val158Met) has received increasing attention as a possible modulator of executive functioning and its neural correlates. However, this attention has generally centered on the prefrontal cortices because of the well-known direct impact of COMT enzyme on these cerebral regions. In this study, we were interested in the modulating effect of COMT genotype on anterior and posterior brain areas underlying interference resolution during a Stroop task. More specifically, we were interested in the functional connectivity between the right inferior frontal operculum (IFop), an area frequently associated with inhibitory efficiency, and posterior brain regions involved in reading/naming processes (the 2 main non-executive determinants of the Stroop effect). The Stroop task was administered during functional magnetic resonance imaging scanning to 3 groups of 15 young adults divided according to their COMT Val158Met genotype [Val/Val (VV), Val/Met (VM), and Met/Met (MM)]. Results indicate greater activity in the right IFop and the left middle temporal gyrus in homozygous VV individuals than in Met allele carriers. In addition, the VV group exhibited stronger positive functional connectivity between these 2 brain regions and stronger negative connectivity between the right IFop and left lingual gyrus. These results confirm the impact of COMT genotype on frontal functions. They also strongly suggest that differences in frontal activity influence posterior brain regions related to a non-executive component of the task. Particularly, changes in functional connectivity between anterior and posterior brain areas might correspond to compensatory processes for performing the task efficiently when the available dopamine level is low. © 2014 The Author 2014.
Albouy G.,Cyclotron Research Center |
Sterpenich V.,Cyclotron Research Center |
Vandewalle G.,Cyclotron Research Center |
Darsaud A.,Cyclotron Research Center |
And 10 more authors.
NeuroImage | Year: 2012
During the initial training of a motor sequence, performance becomes progressively faster but also increasingly reproducible and consistent. However, performance temporarily becomes more variable at mid-training, reflecting a change in the motor representation and the eventual selection of the optimal performance mode (Adi-Japha et al., 2008). At the cerebral level, whereas performance speed is known to be related to the activity in cerebello-cortical and striato-cortical networks, the neural correlates of performance variability remain unknown. We characterized the latter using functional magnetic resonance imaging (fMRI) during the initial training to the Finger Tapping Task (FTT), during which participants produced a 5-element finger sequence on a keyboard with their left non-dominant hand. Our results show that responses in the precuneus decrease whereas responses in the caudate nucleus increase as performance becomes more consistent. In addition, a variable performance is associated with enhanced interaction between the hippocampus and fronto-parietal areas and between the striatum and frontal areas. Our results suggest that these dynamic large-scale interactions represent a cornerstone in the implementation of consistent motor behavior in humans. © 2012 Elsevier Inc.
Boutaayamou M.,University of Liège |
Boutaayamou M.,INTELSIG Laboratory |
Bruls O.,University of Liège |
Denoel V.,University of Liège |
And 6 more authors.
2015 International Conference on 3D Imaging, IC3D 2015 - Proceedings | Year: 2015
We describe a new gait segmentation method based on the continuous wavelet transform to identify stride-by-stride gait cycles from measurements of foot-mounted three-dimensional (3D) accelerometers. The detection of such gait cycles is indeed a crucial step for an accurate extraction of relevant gait events such as heel strike, toe strike, heel-off, and toe-off. We demonstrate the ability of this segmentation method, used in conjunction with a validated extraction algorithm, to calculate the following gait (duration) parameters for each gait cycle during the gait of a healthy young subject and of an elderly subject with Parkinson's disease (PD) in OFF and ON states: durations of (1) loading response, (2) mid-stance, (3) push-off, (4) stance, (5) swing, (6) stride, (7) step, and (8) double support phases. The experimental results show that the proposed method can extract relevant refined gait parameters to quantify subtle gait disturbances in subjects with PD. © 2015 IEEE.
Henrottin J.,Cyclotron Research Center |
Zervosen A.,Cyclotron Research Center |
Lemaire C.,Cyclotron Research Center |
Sapunaric F.,University of Liège |
And 6 more authors.
ACS Medicinal Chemistry Letters | Year: 2015
Indoleamine 2,3-dioxygenase (hIDO) is an enzyme that catalyzes the oxidative cleavage of the indole ring of l-tryptophan through the kynurenine pathway, thereby exerting immunosuppressive properties in inflammatory and tumoral tissues. The syntheses of 1-(2-fluoroethyl)-tryptophan (1-FETrp) and 1-((1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl)methyl)-tryptophan, two N1-fluoroalkylated tryptophan derivatives, are described here. In vitro enzymatic assays with these two new potential substrates of hIDO show that 1-FETrp is a good and specific substrate of hIDO. Therefore, its radioactive isotopomer, 1-[18F]FETrp, should be a molecule of choice to visualize tumoral and inflammatory tissues and/or to validate new potential inhibitors. © 2015 American Chemical Society.
Javanainen A.,University of Jyväskylä |
Trzaska W.H.,University of Jyväskylä |
Trzaska W.H.,Helsinki Institute of Physics |
Harboe-Sorensen R.,European Space Agency |
And 3 more authors.
IEEE Transactions on Nuclear Science | Year: 2010
Semi-empirical fitting based on classical Bohr theory has been applied to the experimental LET data in silicon of the RADEF heavy ion cocktail species. The parameterized LET descriptions to be used in the European Component Irradiation Facilities are introduced and compared with the commonly used estimations from SRIM-code. Also, a new user interface, ECIF Cocktail Calculator, based on this work, has been published under the RADEF webpages at http://www.jyu.fi/accelerator/radef/ECIFCalc. © 2010 IEEE.
Landsness E.,University of Liège |
Landsness E.,University of Wisconsin - Madison |
Bruno M.-A.,University of Liège |
Noirhomme Q.,University of Liège |
And 8 more authors.
Brain | Year: 2011
The existence of normal sleep in patients in a vegetative state is still a matter of debate. Previous electrophysiological sleep studies in patients with disorders of consciousness did not differentiate patients in a vegetative state from patients in a minimally conscious state. Using high-density electroencephalographic sleep recordings, 11 patients with disorders of consciousness (six in a minimally conscious state, five in a vegetative state) were studied to correlate the electrophysiological changes associated with sleep to behavioural changes in vigilance (sustained eye closure and muscle inactivity). All minimally conscious patients showed clear electroencephalographic changes associated with decreases in behavioural vigilance. In the five minimally conscious patients showing sustained behavioural sleep periods, we identified several electrophysiological characteristics typical of normal sleep. In particular, all minimally conscious patients showed an alternating non-rapid eye movement/rapid eye movement sleep pattern and a homoeostatic decline of electroencephalographic slow wave activity through the night. In contrast, for most patients in a vegetative state, while preserved behavioural sleep was observed, the electroencephalographic patterns remained virtually unchanged during periods with the eyes closed compared to periods of behavioural wakefulness (eyes open and muscle activity). No slow wave sleep or rapid eye movement sleep stages could be identified and no homoeostatic regulation of sleep-related slow wave activity was observed over the night-time period. In conclusion, we observed behavioural, but no electrophysiological, sleep wake patterns in patients in a vegetative state, while there were near-to-normal patterns of sleep in patients in a minimally conscious state. These results shed light on the relationship between sleep electrophysiology and the level of consciousness in severely brain-damaged patients. We suggest that the study of sleep and homoeostatic regulation of slow wave activity may provide a complementary tool for the assessment of brain function in minimally conscious state and vegetative state patients. © 2011 The Author.
Seelaar H.,Erasmus University Rotterdam |
Papma J.M.,Erasmus University Rotterdam |
Garraux G.,Cyclotron Research Center |
Garraux G.,University of Liège |
And 7 more authors.
Neurology | Year: 2011
Objective: Frontotemporal lobar degeneration (FTLD) is a clinically, genetically, and pathologically heterogeneous disorder. The aim of this study was to compare clinical features and perfusion patterns on SPECT of patients with familial FTLD-TAR DNA binding protein 43 kDa (TDP) and MAPT mutations. Methods: Patients were included if they had MAPT or GRN mutations, positive family history with pathologically proven FTLD in the patient or first-degree relative, or were part of FTD-MND families. All patients and 10 age- and gender-matched controls underwent measurement of brain perfusion using 99mTc-HMPAO SPECT. We used SPM8 to perform image processing and oxelbased group analyses (p < 0.001). Gender and age were included as nuisance variables in the design matrices. Results: Of the 29 patients with familial FTLD, 19 had familial FTLD-TDP (GRN mutations in 6), and 10 had MAPT mutations. At clinical presentation, familial FTLD-TDP patients were older at onset (p = 0.030) and had more memory deficits (p < 0.011), whereas patients with MAPT had more naming deficits (p = 0.001) and obsessive-compulsive behavior (p = 0.001). The betweengroups SPECT analyses revealed significantly less perfusion in the right frontal lobe, precuneus, cuneus, and inferior parietal lobule in familial FTLD-TDP, whereas significantly less perfusion was found in the left temporal and inferior frontal gyri in MAPT. Post hoc analysis of familial FTLD-TDP with unknown genetic defect vs MAPT revealed less perfusion in the right frontal and parietal lobe. Conclusion: Familial FTLD-TDP shows relatively more posterior hypoperfusion, including the precuneus and inferior parietal lobule, possibly related to significant memory impairment. Patients with MAPT were characterized by impaired perfusion of the temporal regions and naming deficits. © 2011 by AAN Enterprises Inc.