179 research outputs found

    A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability

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    AIM To evaluate a standardised MRI acquisition protocol and a new image rating scale for disease severity in patients with progressive supranuclear palsy (PSP) and multiple systems atrophy (MSA) in a large multicentre study. METHODS The MRI protocol consisted of two-dimensional sagittal and axial T1, axial PD, and axial and coronal T2 weighted acquisitions. The 32 item ordinal scale evaluated abnormalities within the basal ganglia and posterior fossa, blind to diagnosis. Among 760 patients in the study population (PSP = 362, MSA = 398), 627 had per protocol images (PSP = 297, MSA = 330). Intra-rater (n = 60) and inter-rater (n = 555) reliability were assessed through Cohen's statistic, and scale structure through principal component analysis (PCA) (n = 441). Internal consistency and reliability were checked. Discriminant and predictive validity of extracted factors and total scores were tested for disease severity as per clinical diagnosis. RESULTS Intra-rater and inter-rater reliability were acceptable for 25 (78%) of the items scored (≥ 0.41). PCA revealed four meaningful clusters of covarying parameters (factor (F) F1: brainstem and cerebellum; F2: midbrain; F3: putamen; F4: other basal ganglia) with good to excellent internal consistency (Cronbach α 0.75-0.93) and moderate to excellent reliability (intraclass coefficient: F1: 0.92; F2: 0.79; F3: 0.71; F4: 0.49). The total score significantly discriminated for disease severity or diagnosis; factorial scores differentially discriminated for disease severity according to diagnosis (PSP: F1-F2; MSA: F2-F3). The total score was significantly related to survival in PSP (p<0.0007) or MSA (p<0.0005), indicating good predictive validity. CONCLUSIONS The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA. Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224

    Normalisation to Blood Activity Is Required for the Accurate Quantification of Na/I Symporter Ectopic Expression by SPECT/CT in Individual Subjects

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    The utilisation of the Na/I symporter (NIS) and associated radiotracers as a reporter system for imaging gene expression is now reaching the clinical setting in cancer gene therapy applications. However, a formal assessment of the methodology in terms of normalisation of the data still remains to be performed, particularly in the context of the assessment of activities in individual subjects in longitudinal studies. In this context, we administered to mice a recombinant, replication-incompetent adenovirus encoding rat NIS, or a human colorectal carcinoma cell line (HT29) encoding mouse NIS. We used 99mTc pertechnetate as a radiotracer for SPECT/CT imaging to determine the pattern of ectopic NIS expression in longitudinal kinetic studies. Some animals of the cohort were culled and NIS expression was measured by quantitative RT-PCR and immunohistochemistry. The radioactive content of some liver biopsies was also measured ex vivo. Our results show that in longitudinal studies involving datasets taken from individual mice, the presentation of non-normalised data (activity expressed as %ID/g or %ID/cc) leads to ‘noisy’, and sometimes incoherent, results. This variability is due to the fact that the blood pertechnetate concentration can vary up to three-fold from day to day. Normalisation of these data with blood activities corrects for these inconsistencies. We advocate that, blood pertechnetate activity should be determined and used to normalise the activity measured in the organ/region of interest that expresses NIS ectopically. Considering that NIS imaging has already reached the clinical setting in the context of cancer gene therapy, this normalisation may be essential in order to obtain accurate and predictive information in future longitudinal clinical studies in biotherapy

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    [Does diffusion and perfusion MRI modify the diagnosis and management of cerebral ischemic accidents?]

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    International audienceSince 25 years, CT has the capability to recognize hemorrhagic infarcts in emergency. On the other hand, cytotoxic oedema is visible only 12 or 24 hours after the onset of the ischemic stroke. T2 weighted MR-sequences are more sensitive and few hours after the onset, cytotoxic oedema appears as hypersignal, particularly using FLAIR sequences (Fluid Attenuated Inversion Recuperation). Described in 1986, diffusion-weighted MRI is a very sensitive technique to detect the cytotoxic oedema few minutes after the onset. The attenuation of the apparent diffusion coefficient must be evaluated with a map. This attenuation appears as hypersignal and its sensibility is close than 100%. The mismatch between data of perfusion MRI and diffusion MRI is the area of the ischemic penumbra. These new MRI techniques are easy to learn and must be available 24 h a day and 7 days a week in the stroke centers. They are simple, rapid and highly accurate for the diagnosis of acute ischemic stroke. They could be useful to select candidates to aggressive therapy during the first 3 or 6 hours. Potentially, they improve patient's outcome

    Le besoin éducatif particulier, un moment d’exception pédagogique : regards croisés des enseignants du premier et du second degré

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    Les études sur l’inclusion des élèves à BEP en classe ordinaire interrogent les pratiques enseignantes, soit en termes d’obstacles à l‘apprentissage, soit en termes d’écart aux attentes institutionnelles. À partir de la théorie de Becker, notre approche s’intéresse au moment où l’enseignant sursoit à ses attentes, modifiant la situation au regard de cette particularité de l’élève. Nous montrons comme Roiné que l’exception pédagogique et didactique opérée est une construction sociale qui rend compte, à rebours, des normes véhiculées par les enseignants. La confrontation des solutions singulières proposées par les deux types d’enseignants (premier et second degrés) montre, au-delà d’une préférence liée à leur formation (plutôt pédagogique pour l’un et plutôt didactique pour l’autre), que la différenciation répond plus au trouble du déroulement de l’apprentissage collectif qu’au besoin éducatif lui-même

    [Functional MRI: brain plasticity, brain disease and functional recovery]

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    International audienceBrain plasticity may be defined as long-term alteration in behavior related activity of distributed neural systems. Functional imaging, and particularly functional MRI, allows to investigate the mechanisms underlying brain plasticity. Two aspects may be distinguished: one is learning in healthy subjects; the other is functional reorganization following or associated with acute or chronic brain injury. Because functional MRI is totally non invasive, it appears well suited to follow such reorganization over time. This theme will be developed in the following text

    [Functional MRI: brain plasticity, brain disease and functional recovery]

    No full text
    International audienceBrain plasticity may be defined as long-term alteration in behavior related activity of distributed neural systems. Functional imaging, and particularly functional MRI, allows to investigate the mechanisms underlying brain plasticity. Two aspects may be distinguished: one is learning in healthy subjects; the other is functional reorganization following or associated with acute or chronic brain injury. Because functional MRI is totally non invasive, it appears well suited to follow such reorganization over time. This theme will be developed in the following text
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