44 research outputs found
Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography
A prospective study was performed on neurosurgical samples from 18 patients
to evaluate the use of Full-Field Optical Coherence Tomography (FF-OCT) in
brain tumor diagnosis. FF-OCT captures en face slices of tissue samples at
1\mum resolution in 3D with a typical 200\mum imaging depth. A 1cm2 specimen is
scanned at a single depth and processed in about 5 minutes. This rapid imaging
process is non-invasive and 30 requires neither contrast agent injection nor
tissue preparation, which makes it particularly well suited to medical imaging
applications. Temporal chronic epileptic parenchyma and brain tumors such as
meningiomas, low- grade and high-grade gliomas, and choroid plexus papilloma
were imaged. A subpopulation of neurons, myelin fibers and CNS vasculature were
clearly identified. Cortex could be discriminated from white matter, but
individual glial cells as astrocytes (normal or reactive) or oligodendrocytes
were not observable. This study reports for the first time on the feasibility
of using FF-OCT in a real-time manner as a label-free non-invasive imaging
technique in an intra-operative neurosurgical clinical setting to assess
tumorous glial and epileptic margins
Etude des liens entre les systÚmes visuel et proprioceptif : approche électrophysiologique et comportementale chez le sujet sain et le patient amputé du membre supérieur
Le codage de la position et des mouvements des diffĂ©rents segments corporels implique lâintervention coordonnĂ©e des systĂšmes perceptifs visuel et proprioceptif. Lâobjectif
de ce travail de thÚse était de caractériser la nature de ces interactions dans le contrÎle moteur.
Notre dĂ©marche, basĂ©e sur une investigation par les potentiels Ă©voquĂ©s consistait Ă mesurer lâactivitĂ© Ă©lectrique du cortex moteur primaire lors dâune activitĂ© visuomotrice. Nous avons pu montrer que la simple vue dâun effecteur (e.g., main) suffit pour provoquer une planification motrice dans le cortex moteur correspondant, quâil sâagisse effectivement de lâeffecteur ou quâil sâagisse dâune image reconstituĂ©e artificiellement, par le biais dâun miroir reflĂ©tant la main opposĂ©e, par exemple. Ces rĂ©sultats attestent de lâinfluence de la vision sur les
processus de planification du mouvement et fournissent une mesure objective des effets de la vision sur le cortex moteur.
Dans un second temps, nous avons Ă©tudiĂ© lâinfluence du feedback visuel lorsque le membre est absent, avec des patients amputĂ©s du membre supĂ©rieur. Cette approche nous a permis dâĂ©valuer lâimpact de lâexpĂ©rience perceptive en comparant les donnĂ©es dâamputĂ©s traumatiques avec celles de personnes agĂ©nĂ©siques, dont lâorigine de lâabsence du membre
est congĂ©nitale. Ainsi nous montrons que lâactivation motrice corticale peut ĂȘtre gĂ©nĂ©rĂ©e par un feedback visuel du membre absent seulement si le systĂšme moteur est (sujets sans dĂ©ficit sensorimoteur) ou a Ă©tĂ© fonctionnel (amputĂ©s traumatiques). De plus, nous montrons que cette activitĂ© corticale reflĂšte une programmation motrice en cohĂ©rence avec le mouvement Ă effectuer. En effet, les performances motrices dans une tĂąche de dessin en miroir sont meilleures chez ces sujets lorsquâils ont un feedback sagittal de leur main active (i.e. donnant lâimpression de voir leur main absente). Nous proposons que le feedback visuel provoque la rĂ©activation de programmes moteurs existants, en lien avec la main vue et la tĂąche Ă rĂ©aliser. Ces rĂ©sultats fournissent une preuve directe de la persistance fonctionnelle des rĂ©gions dĂ©nervĂ©es suite Ă lâamputation traumatique dâun membre
Etude des liens entre les systÚmes visuel et proprioceptif (Approche électrophysiologique et comportementale chez le sujet sain et le patient amputé du membre supérieur)
Le codage de la position et des mouvements des diffĂ©rents segments corporels implique l intervention coordonnĂ©e des systĂšmes perceptifs visuel et proprioceptif. L objectif de ce travail de thĂšse Ă©tait de caractĂ©riser la nature de ces interactions dans le contrĂŽle moteur. Notre dĂ©marche, basĂ©e sur une investigation par les potentiels Ă©voquĂ©s consistait Ă mesurer l activitĂ© Ă©lectrique du cortex moteur primaire lors d une activitĂ© visuomotrice. Nous avons pu montrer que la simple vue d un effecteur (e.g., main) suffit pour provoquer une planification motrice dans le cortex moteur correspondant, qu il s agisse effectivement de l effecteur ou qu il s agisse d une image reconstituĂ©e artificiellement, par le biais d un miroir reflĂ©tant la main opposĂ©e, par exemple. Ces rĂ©sultats attestent de l influence de la vision sur les processus de planification du mouvement et fournissent une mesure objective des effets de la vision sur le cortex moteur. Dans un second temps, nous avons Ă©tudiĂ© l influence du feedback visuel lorsque le membre est absent, avec des patients amputĂ©s du membre supĂ©rieur. Cette approche nous a permis d Ă©valuer l impact de l expĂ©rience perceptive en comparant les donnĂ©es d amputĂ©s traumatiques avec celles de personnes agĂ©nĂ©siques, dont l origine de l absence du membre est congĂ©nitale. Ainsi nous montrons que l activation motrice corticale peut ĂȘtre gĂ©nĂ©rĂ©e par un feedback visuel du membre absent seulement si le systĂšme moteur est (sujets sans dĂ©ficit sensorimoteur) ou a Ă©tĂ© fonctionnel (amputĂ©s traumatiques). De plus, nous montrons que cette activitĂ© corticale reflĂšte une programmation motrice en cohĂ©rence avec le mouvement Ă effectuer. En effet, les performances motrices dans une tĂąche de dessin en miroir sont meilleures chez ces sujets lorsqu ils ont un feedback sagittal de leur main active (i.e. donnant l impression de voir leur main absente). Nous proposons que le feedback visuel provoque la rĂ©activation de programmes moteurs existants, en lien avec la main vue et la tĂąche Ă rĂ©aliser. Ces rĂ©sultats fournissent une preuve directe de la persistance fonctionnelle des rĂ©gions dĂ©nervĂ©es suite Ă l amputation traumatique d un membre.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF
Motor Cortex Activation Induced by a Mirror: Evidence From Lateralized Readiness Potentials
Behavioral and Electrophysiological Evidence of Motor Cortex Activation Related to an Amputated Limb: A Multisensorial Approach
Impact of patient ancestry on heterogeneity of Sjögrenâs disease
Objectives We aimed to compare disease characteristics between primary Sjögrenâs syndrome (pSS) patients of African ancestry (AA) and Caucasian ancestry.Methods We conducted a retrospective, caseâcontrol study in a French national and European referral centre for pSS. All patients with pSS of AA were matched with two Caucasians patients having similar follow-up duration. We explored clinical and biological parameters associated with a cumulative EULAR Sjögrenâs Syndrome Disease Activity Index (cumESSDAI â„5) (consisting of individual clinESSDAI domain maximum throughout follow-up).Results We identified 74 patients of AA matched with 148 Caucasian. Median age at pSS diagnosis was younger in AA patients (43 years (IQR 33â51) vs 56 years (44.8â59.2), p<0.001). AA patients presented higher median titre of gammaglobulins (18.5 g/L (IQR 15â22.8) vs 13.4 g/L (9.9â16.9), p<0.001), more frequently positive for anti-SSA (88% vs 72%, p=0.007) and anti-RNP (11% vs 2.7%, p=0.023) antibodies. During the follow-up (median: 6 years (IQR 2â11)), AA patients presented more systemic complications: arthritis, myositis, interstitial lung disease, lymphadenopathy, central nervous system involvement. Median cumESSDAI score was higher in AA patients (7.5 (IQR 3.2â16.0) vs 4.0 (IQR 2.0â9.0), p=0.002). Interestingly, in multivariate analyses, factors associated with disease activity were sub-Saharan AA (OR 2.65 (95% CI 1.06 to 6.94)), rheumatoid factor (OR 2.50 (95% CI 1.28 to 4.96)) and anti-RNP positivity (OR 11.1 (95% CI 1.88 to 212)).Conclusion Patients of AA display higher disease activity with a hallmark of higher B-cell activation. Studies to investigate biological drivers behind such differences are needed
Mutation in the mitochondrial translation elongation factor EFTs results in severe infantile liver failure
Background & AimsMultiple respiratory chain deficiencies represent a common cause of mitochondrial diseases and often result in hepatic failure. A significant fraction of patients present mitochondrial DNA depletion but a number of cases remain unexplained. The aim of our study was to identify the disease causing gene in a kindred with intrauterine growth retardation, neonatal lactic acidosis, liver dysfunction and multiple respiratory chain deficiency in muscle.MethodsHomozygosity mapping was performed by 50K SNP genotyping and candidate genes were successively analyzed by direct sequencing on genomic DNA of the family members.ResultsSNP genotyping detected several regions of homozygosity in which we focused our attention to genes involved in mitochondrial translation. We sequenced the TSFM gene, encoding the mitochondrial translation factor EFTs and identified a homozygous mutation changing a highly conserved arginine into a tryptophan (R312W).ConclusionsThis mutation has been previously reported in two unrelated kindred presenting two distinct syndromes (fatal mitochondrial encephalomyopathy and hypertrophic cardiomyopathy respectively). The description of a third syndrome associated with a same TSFM mutation gives support to the broad clinical and genetic heterogeneity of mitochondrial translation deficiencies in human. It suggests that mitochondrial translation deficiency represents a growing cause of hepatic failure of mitochondrial origin in infants
Anti-RNP positivity in primary Sjogren's syndrome is associated with a more active disease and a more frequent muscular and pulmonary involvement
International audienceObjectives To describe and compare the clinical and biological characteristics of subjects with primary Sjogren's syndrome (pSS) with and without anti-RNP antibodies. Methods Patients fulfilling the American College of Rheumatology (ACR)/EULAR 2016 criteria for pSS and having anti-RNP antibodies, without other connective tissue disease diagnosed and no anti-dsDNA antibodies were retrieved from the database from our French National Reference Center. These patients were compared with all other patients with pSS with negative anti-Sm, anti-RNP and anti-dsDNA antibodies. Results Overall, 21 patients with pSS positive for anti-RNP antibodies and 446 negative for anti-RNP antibodies were retrieved. Anti-RNP-positive patients had a lower median age at onset of pSS symptoms (41.0 vs 50.0 years, p=0.01), a higher median EULAR Sjogren's syndrome disease activity index at inclusion (8.0 vs 3.0, p= 1 (66.7% vs 85.5%, p=0.03). If the analysis is restricted to anti-SSA-positive patients, anti-RNP positivity is associated with the same clinicobiologic features except the pulmonary involvement. Conclusion Patients with pSS with anti-RNP antibodies displayed a more active systemic disease, with more frequent muscular and pulmonary involvement, and increased gammaglobulin level, compared with anti-RNP-negative patients