| 1. |
- Ciumas, C., et al.
(författare)
-
White matter development in children with benign childhood epilepsy with centro-temporal spikes
- 2014
-
Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 137:4, s. 1095-1106
-
Tidskriftsartikel (refereegranskat)abstract
- Benign childhood epilepsy with centro-temporal spikes (BCECTS) is associated with cognitive disturbances thought to reflect interference between the epileptic focus and brain development. Using diffusion tensor imaging, Ciumas et al. demonstrate abnormal maturation of white matter at the epileptic focus, which correlates with duration of epilepsy and cognitive performance.Benign childhood epilepsy with centro-temporal spikes (BCECTS) is a unique form of non-lesional age-dependent epilepsy with rare seizures, focal electroencepalographic abnormalities affecting the same well delineated cortical region in most patients, and frequent mild to moderate cognitive dysfunctions. In this condition, it is hypothesized that interictal electroencepalographic discharges might interfere with local brain maturation, resulting in altered cognition. Diffusion tensor imaging allows testing of this hypothesis by investigating the white matter microstructure, and has previously proved sensitive to epilepsy-related alterations of fractional anisotropy and diffusivity. However, no diffusion tensor imaging study has yet been performed with a focus on BCECTS. We investigated 25 children suffering from BCECTS and 25 age-matched control subjects using diffusion tensor imaging, 3D-T-1 magnetic resonance imaging, and a battery of neuropsychological tests including Conner's scale and Wechsler Intelligence Scale for Children (fourth revision). Electroencephalography was also performed in all patients within 2 months of the magnetic resonance imaging assessment. Parametric maps of fractional anisotropy, mean-, radial-, and axial diffusivity were extracted from diffusion tensor imaging data. Patients were compared with control subjects using voxel-based statistics and family-wise error correction for multiple comparisons. Each patient was also compared to control subjects. Fractional anisotropy and diffusivity images were correlated to neuropsychological and clinical variables. Group analysis showed significantly reduced fractional anisotropy and increased diffusivity in patients compared with control subjects, predominantly over the left pre- and postcentral gyri and ipsilateral to the electroencephalographic focus. At the individual level, regions of significant differences were observed in 10 patients (40%) for anisotropy (eight reduced fractional anisotropy, one increased fractional anisotropy, one both), and 17 (56%) for diffusivity (13 increased, one reduced, three both). There were significant negative correlations between fractional anisotropy maps and duration of epilepsy in the precentral gyri, bilaterally, and in the left postcentral gyrus. Accordingly, 9 of 12 patients (75%) with duration of epilepsy > 12 months showed significantly reduced fractional anisotropy versus none of the 13 patients with duration of epilepsy 12 months. Diffusivity maps positively correlated with duration of epilepsy in the cuneus. Children with BCECTS demonstrate alterations in the microstructure of the white matter, undetectable with conventional magnetic resonance imaging, predominating over the regions displaying chronic interictal epileptiform discharges. The association observed between diffusion tensor imaging changes, duration of epilepsy and cognitive performance appears compatible with the hypothesis that interictal epileptic activity alters brain maturation, which could in turn lead to cognitive dysfunction. However, such cross-sectional association does not demonstrate causality, and other hitherto unidentified factors could represent the common cause to part or all of the observed findings.
|
|
| 2. |
- Bonnefoy, C, et al.
(författare)
-
Prenatal diagnosis of lobar bronchial atresia
- 2011
-
Ingår i: Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. - 1469-0705. ; 37:1, s. 110-112
-
Tidskriftsartikel (refereegranskat)
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Gossec, Laure, et al.
(författare)
-
OARSI/OMERACT Initiative to Define States of Severity and Indication for Joint Replacement in Hip and Knee Osteoarthritis. An OMERACT 10 Special Interest Group
- 2011
-
Ingår i: Journal of Rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 38:8, s. 1765-1769
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. To define pain and physical function cutpoints that would, coupled with structural severity, define a surrogate measure of "need for joint replacement surgery," for use as an outcome measure for potential structure-modifying interventions for osteoarthritis (OA). Methods. New scores were developed for pain and physical function in knee and hip OA. A cross-sectional international study in 1909 patients was conducted to define data-driven cutpoints corresponding to the orthopedic surgeons' indication for joint replacement. A post hoc analysis of 8 randomized clinical trials (1379 patients) evaluated the prevalence and validity of cutpoints, among patients with symptomatic hip/knee OA. Results. In the international cross-sectional study, there was substantial overlap in symptom levels between patients with and patients without indication for joint replacement; indeed, it was not possible to determine cutpoints for pain and function defining this indication. The post hoc analysis of trial data showed that the prevalence of cases that combined radiological progression, high level of pain, and high degree of function impairment was low (2%-12%). The most discriminatory cutpoint to define an indication for joint replacement was found to be [pain (0-100) + physical function (0-100) > 80]. Conclusion. These results do not support a specific level of pain or function that defines an indication for joint replacement. However, a tentative cutpoint for pain and physical function levels is proposed for further evaluation. Potentially, this symptom level, coupled with radiographic progression, could be used to define "nonresponders" to disease-modifying drugs in OA clinical trials. (J Rheumatol 2011;38:1765-9; doi:10.3899/jrheum.110403)
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Coste, S, et al.
(författare)
-
Assessing foliar chlorophyll contents with the SPAD-502 chlorophyll meter: 165 a calibration test with thirteen tree species of tropical rainforest in French Guiana
- 2010
-
Ingår i: Annals of Forest Science. - 1286-4560. ; 67:6
-
Tidskriftsartikel (refereegranskat)abstract
- • Chlorophyll meters such as the SPAD-502 offer a simple, inexpensive and rapid method to estimate foliar chlorophyll content. However, values provided by SPAD-502 are unitless and require empirical calibrations between SPAD units and extracted chlorophyll values. • Leaves of 13 tree species from the tropical rain forest in French Guiana were sampled to select the most appropriate calibration model among the often-used linear, polynomial and exponential models, in addition to a novel homographic model that has a natural asymptote. • The homographic model best accurately predicted total chlorophyll content (µg cm-2) from SPAD units (R² = 0.89). Inter-specific differences in the homographic model parameters explain less than 7% of the variation in chlorophyll content in our dataset. • The utility of the general homographic model for a variety of research and management applications clearly outweighs the slight loss of model accuracy due to the abandon of the species-effect.
|
|
| 10. |
|
|
