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Biomedical subjects

E Vandenbussche

Publications and source records attributed to E Vandenbussche.

At least 19 recordsLinked to original sources
PubMed2002

Longitudinal study evaluating neuropsychological changes in so-called asymptomatic carriers of the Huntington's disease mutation after 1 year.

OBJECTIVES: To determine (1) whether the battery of neuropsychological tests was sufficiently sensitive to find differences between symptomatic patients with Huntington's disease (HD) and clinically asymptomatic individuals carrying the HD gene (AGC) and individuals without the HD gene (NGC) and (2) whether increasing cognitive impairment is found in AGC as compared with NGC. METHODS: A case-control, single-blind study comparing subjects with clinically manifest HD (n=21), AGC (n=12) or NGC (n=11) and a 1-year follow-up of AGC and NGC. Genotype for the HD gene was determined by molecular testing. A large battery of neuropsychological tests measuring several cognitive domains was performed. RESULTS: On most neuropsychological tasks, HD patients perform significantly worse than AGC and NGC. At baseline and follow-up examination, compared with NGC, AGC had lower scores on the symbol digit modalities test. Scores on a block span task declined more rapidly among AGC than among NGC. CONCLUSION: Cognitive impairments in HD patients are found when compared with clinically asymptomatic individuals carrying the HD mutation. Furthermore, our results suggest that subtle cognitive deficits are present in asymptomatic persons who have inherited the HD gene.

Adult↗
PubMed2002

[Bipolar arthroplasty in rotator cuff arthropathy: 13 cases].

PURPOSE OF THE STUDY: A series of 13 patients with an excentered osteoarthritis of the glenoid who underwent bipolar shoulder arthroplasty is reported. MATERIAL AND METHODS: The series included 13 patients treated in two centers between 1995 and 1998. Mean age was 70 years (58-88). Constant's absolute score and Swanson's score were used for clinical assessment. The Hamada and Fukuda classification was used for the radiographic assessment. The follow-up radiography series included an AP view in the three rotation positions, an AP view in maximum abduction to assess intraprosthetic mobility, a lateral view (Lamy) and measurements of both humeri. Several measurements were made to assess humerus lateralization and glenoid wear: deltoid lever arm, lateral humeral displacement, distance between the lateral border of the coracoid and the center of the glenoid and the subacromial space. Mean preoperative Constant score was 23 points: pain 3 pts, activity 5 pts, motion 13 pts, force 2 pts. Mean preoperative Swanson score was 11. Active anteflexion was 78 degrees, active abduction 68 degrees and passive external rotation 17 degrees. The Hamada and Fukuda classification was 9 grade 4 and 4 grade 5. All patients had a full thickness unrepairable rotator cuff tear: three with 2 tendon tears, and 10 with 3 tendon tears. All patients were reviewed clinically and had a complete radiography series at last follow-up (mean 28 months, range 7 - 56 months). RESULTS: At last follow-up, the mean absolute Constant score was 37 points: pain 10 pts, activity 9 pts, motion 14 pts, force 4 pts. Mean Swanson score at last follow-up was 19 points. Mean active anteflexion was 69 degrees, active abduction was 63 degrees and passive external rotation was 29 degrees. A satisfactory deltoid lever arm had been achieved compensating the glenoid wear by a greater lateral displacement of the humerus. At last follow-up, there were no cases of humeral loosening but three cases with important glenoid wear were observed after two years. Comparing the results obtained using small cups (40 and 44) with arthroplasties using large cups (48 and 52) showed a trend favoring small cups: Constant score 43 vs 32 points, Swanson score 21 versus 17 points, anteflexion 72 degrees versus 66 degrees and passive external rotation 34 degrees versus 26 degrees. DISCUSSION: Our results confirmed the efficacy of bipolar arthroplasty for pain relief, but the mobility outcome was less than satisfactory, excepting passive external rotation. It would appear to be preferable to use small cups. Comparing our results with data in the literature, particularly the better results for mobility using simple humeral prostheses, suggests that the principles of shoulder and hip arthroplasty concern different mechanisms: a sufficient deltoid lever arm must be achieved, but without overstretching the periarticular soft tissue (capsule, subcapsule, teres minor), and using a cup size close to the size of the healthy humeral head. Glenoid reaming should not be reserved only for asymmetrical glenoid wear in the horizontal plane. CONCLUSION: Our results suggest that bipolar arthroplasty for excentered osteoarthritis of the glenoid cavity is indicated for: stiffness in external rotation, major concentric wear in patients under 65 years of age, or asymmetric glenoid wear.

Aged↗
PubMed2002

[The superolateral approach for shoulder prosthesis].

We describe a superolateral approach to the shoulder for implantation of total shoulder prostheses or humeral prostheses. The advantages of this approach include preservation of the supraspinatus tendon and an excellent exposure of the posterior part of the glenoid cavity. We illustrate this approach with three clinical examples: total shoulder arthroplasty with reconstruction of the posterior part of the glenoid using a screwed autograft for central degeneration with posterior wear of the glenoid, intermediate arthroplasty for excentric degeneration with irreparable rotator cuff tears, and simple humeral arthroplasty with bone suture of the tuberosities for cephalotuberosity fracture.

Arthroplasty, Replacement↗
PubMed2001

Psychophysical evidence for a general temporal processing deficit in children with dyslexia.

The hypothesis of a general (i.e. cross-modal) temporal processing deficit in dyslexia was tested by examining rapid processing in both the auditory and the visual system in the same children with dyslexia. Participants were 10- to 12-year-old dyslexic readers and age-matched normal reading controls. Psychophysical thresholds were estimated for auditory gap and visual double flash detection, using a two-interval, two-alternative forced-choice paradigm. Significant group differences were found for the auditory and the visual test. Furthermore, temporal processing measures were significantly related to word and pseudo-word reading skills. As 70% of the dyslexic readers had significantly higher thresholds than controls for both auditory and visual temporal processing, the evidence tends to support the hypothesis of a general temporal processing deficit in children with dyslexia.

Auditory Perception↗
PubMed2001

Analysis of extracellular gamma-aminobutyric acid, glutamate and aspartate in cat visual cortex by in vivo microdialysis and capillary electrophoresis-laser induced fluorescence detection.

To investigate the influence of a partial sensory deprivation on the extracellular concentration of amino acid neurotransmitters in cat visual cortex, a capillary electrophoresis method was developed for the quantification of gamma-aminobutyric acid (GABA), glutamate (Glu) and aspartate (Asp) in in vivo microdialysis samples of cat brain. Microdialysis samples from different regions of area 17 were obtained every 15-min using CMA 12 2-mm probes perfused with synthetic cerebrospinal fluid and derivatized using fluorescein isothiocyanate (FITC). Laser-induced fluorescence (LIF) detection was employed. Good selectivity was obtained with a borate buffer (20 mM, pH 10.25). The whole procedure, including the washing step takes only 15 min. The conditions for derivatization and separation were optimized. The parameters for validation such as linearity, precision and detection limit are also reported. The results are consistent with those of HPLC but, as the sample volumes needed are only 1--5 nl, a much better time resolution can be obtained.

Animals↗
PubMed2001

The variety of visual perceptual impairments in pre-school children with perinatal brain damage.

To study the selectivity of visual perceptual impairment in children with early brain injury, eight visual perceptual tasks (L94), were administered to congenitally disabled children both with and without risk for cerebral visual impairment (CVI). The battery comprised six object-recognition and two visuoconstructive tasks. Seven tasks were newly designed. For these normative data are presented (age 2.75-6.50 years). Because the recognition tasks required object naming, each item included a canonical control drawing and visual perceptual ability was evaluated relative to the non-verbal intelligence level, instead of chronological age. In 22 multiple disabled children with no indications of CVI, the frequency of impairment did not exceed that in the reference sample for any L94 task. In contrast, in 57 5-year-old children who were at risk for CVI due to pre-maturity or birth asphyxia, a significant increase in the frequency of impairment was seen on six L94 tasks (range 12-38%). However, only five children had more than two impairments, indicating that the deficits were selective, not pervasive. We conclude that early brain lesions interfere with the functioning of particular visual subsystems, yet leave other subsystems intact and functioning within the normal range.

Agnosia↗
PubMed2001

In vivo microdialysis in the visual cortex of awake cat. I: surgery, animal training and sampling.

Sampling and monitoring release of excitatory and inhibitory amino acids in the striate cortex of mammals will provide important information for visual system research. A method allowing repeated microdialysis in the cortical layers of area 17 of the awake cat is described. Under visual control through a surgical microscope and using a stereotactic instrument, four probe guides are permanently implanted in area 17 of one hemisphere of the anesthetized animal and two fixation bars are mounted on the skull to allow fixation of the cat in a stereotactic frame. The implantation of four probe guides in the same hemisphere allows simultaneous sampling from different cortical regions subserving different parts of the visual field. A removable transparent cover protects the probe guides. After recovery from surgery the awake cats are trained to adapt to a fixation in a stereotaxic apparatus. Once adapted to that situation, the cats are used for 5 h in vivo microdialysis experiments without anesthesia.

Amino Acids↗
PubMed2001

In vivo microdialysis in the visual cortex of awake cat. II: sample analysis by microbore HPLC-electrochemical detection and capillary electrophoresis-laser-induced fluorescence detection.

Sampling and monitoring release of excitatory and inhibitory amino acids in the striate cortex of mammals will provide important information for visual system research. Two microbore high performance liquid chromatography-electrochemical detection methods and a capillary electrophoresis-laser induced fluorescence detection were developed to determine the inhibitory amino acid, gamma-aminobutyric acid and the excitatory amino acids, glutamate and aspartate in microdialysates of cat striate cortex. In the liquid chromatography method, samples were derivatized using OPA-TBT. Ten microliters of derivatized product was injected onto the microbore column (100 x 1 mm i.d., C8) for quantitative analysis. Electrochemical detection was employed. In the capillary electrophoresis method, samples were derivatized using fluorescein isothiocyanate and separated in borate buffer within 15 min, then detected by a laser-induced fluorescence detector.

Amino Acids↗
PubMed2001

In vivo microdialysis in the visual cortex of awake cat. III: histological verification.

In vivo microdialysis sampling extracellular excitatory and inhibitory amino acids from the striate cortex of mammals will provide important information for visual system research. To facilitate the interpretation of microdialysis results, this protocol critically examines: (1) the location of probe implantation in the visual cortex using Nissl staining; (2) the morphological changes after probe implantation by visualization of neurons containing glutamate; (3) the morphological changes after probe implantation by visualization of gliosis using glial fibrillary acidic protein (GFAP) immunocytochemistry; (4) the implantation of the probe in sensory-deprived versus non-deprived cortical regions by visualization of neurons containing c-Fos protein after limited retinal lesion. The histochemical and immunocytochemical methods of Glu, GFAP and c-Fos used are described.

Animals↗
PubMed2001

Visuoperceptual impairment in MS patients: nature and possible neural origins.

Failures on visuoperceptual neuropsychological tasks (on neuropsychological tests of visuo-spatial perception or on tests concerning semantic properties of visual objects), may indicate focal deficits of visuoperceptual function, or could be the result of (an)other (peripheral) visual deficit(s), or be the effect of a more general cognitive decline. In multiple sclerosis (MS) patients exhibiting sufficient visual acuity and not showing severe cognitive deterioration, impairment on a comprehensive set of 31 visuoperceptual neuropsychological tasks was compared with spatial resolution deficits (SRD), temporal resolution deficits (TRD) for visual stimuli, abnormal pattern shift visual evoked potential (PSVEP) responses, and failing scores on neuropsychological tasks other than visuoperceptual tasks. Impairment on the visuoperceptual neuropsychological tasks was highly independent from the other abnormal visual and cognitive neurological impairments examined, suggesting that it mostly represented focal deficits. Only TRD in both eyes related to this impairment and this relationship was rather weak. Thus in some MS patients a slowed visual information processing may be one of the combined deficits underlying visuoperceptual neuropsychological task impairment. Given that SRD and TRD were not related to another stage of MS and reflect disturbances of a P (parvocellular channel and ventral stream projections) and M (magnocellular channel and dorsal stream projections) visual-system function respectively, demyelination of a certain M pathway may become a co-determinant of visuoperceptual neuropsychological task impairment more rapidly than damage to a certain P pathway.

Adult↗
PubMed2001

[Infection of a total knee prosthesis revealed by an abscess of the posterior leg compartment. A case report].

We report a case of infection of a non-cemented total knee prosthesis that led to abscess formation in the posterior compartment of the leg. This case illustrates the deleterious effect of screws used to fix the non-cemented articular surface of the tibia. Infection, like osteolysis due to polyethylene granuloma, can develop along the screw tract and reach the posterior compartment, especially when the screw protrudes through the posterior cortical of the tibia. Diffusion of an intra-articular event into the posterior compartment should be suspected in patients with a total knee prosthesis who experience calf pain.

Abscess↗
PubMed2000

Sampling extracellular aspartate, glutamate and gamma-aminobutyric acid in striate cortex of awake cat by in vivo microdialysis: surgical and methodological aspects.

A method which permits repeated microdialysis in the cortical layers of area 17 of the awake cat is described. Under visual control through a surgical microscope and using a stereotactic instrument, four probe guides are permanently implanted in area 17 of one hemisphere of the anesthetized animal and two fixation bars are mounted on the skull to allow fixation of the cat in a stereotactic frame. The implantation of four probe guides in the same hemisphere allows simultaneous sampling from different cortical regions serving different parts of the visual field. A removable transparent cover protects the probe guides. After recovery from surgery the awake cats are trained to adapt to a fixation of 5 h in a stereotaxic apparatus. Once adapted to that situation, the cats are ready for microdialysis experiments without anesthesia. The day of the experiment, the awake animal was fixed in the stereotactic frame and the probes inserted into the guides. To test the validity of the method, the basal efflux and the depolarization efflux, triggered by the addition of 65 mM K(+) to the artificial cerebrospinal fluid, of the amino acids aspartate, glutamate and gamma-aminobutyric acid are measured by two HPLC-electrochemical detection methods. The exact localization of the probes and the reaction of the surrounding tissue is studied using immunocytochemistry for glutamate and glial fibrilary acidic protein. Our neurochemical and morphological results suggest the feasibility of multiple and repeated probe insertions for microdialysis experiments in the cerebral cortex of awake and behaving cat. This method provides a new tool to investigate the cortical plasticity.

Animals↗
PubMed2000

Impairment in motion discrimination tasks is unrelated to amount of damage to superior temporal sulcus motion areas.

The behavioral role of the middle temporal (MT/V5) area and its satellites in motion processing is still unclear, particularly the degree to which MT/V5 proper is critical for different types of motion processing. Therefore, effects of small and large lesions in the caudal part of the superior temporal sulcus of macaque monkeys were compared for two tasks requiring different types of motion processing: a direction and a kinetic orientation discrimination. The small lesion was restricted to the peripheral representation of MT/V5 but included V4t, whereas the large lesion included all of MT/V5 and the medial superior temporal (MST) area as well as substantial parts of the floor of the superior temporal (FST) area. Both lesions resulted in significant and long-lasting impairment of direction discrimination but had a lesser effect on kinetic orientation discrimination. Thus the effects of small STS lesions on motion perception are much stronger than expected.

Animals↗
PubMed2000

Relation between visual perceptual impairment and neonatal ultrasound diagnosis of haemorrhagic-ischaemic brain lesions in 5-year-old children.

Visual-perceptual abilities were assessed in 5-year-old children with the following neonatal neurological conditions: born preterm with normal ultrasound scan (NL, n=17); born preterm with ultrasound diagnosis of intraventricular haemorrhage (IVH, n=17); born preterm with ultrasound diagnosis of periventricular leukomalacia (PVL, n=12); born term with hypoxic-ischaemic encephalopathy (HIE, n=11). Visual-perceptual ability was evaluated with the L94: eight visual-perceptual tasks designed to evaluate different aspects of visual perception at the preschool level in children with multiple disabilities. Impairment was established in comparison to the performance age obtained on non-verbal intelligence subtests, instead of chronological age. Frequency of L94 impairment was highest in children with PVL, while children with IVH did not differ from the NL control group. Impairment rates were increased also in children with transient periventricular echodensities, and in children with HIE. Impairments were only moderately related to the delay of visual acuity maturation in infancy.

Cerebral Hemorrhage↗
PubMed2000

A new cat Fos antibody to localize the immediate early gene c-fos in mammalian visual cortex after sensory stimulation.

We developed a novel antibody against cat Fos by immunizing rabbits with a 26-amino-acid peptide. Immunocytochemistry on visual cortex of cats undergoing different visual manipulations was applied to test the reliability and the efficacy of this antiserum. One hour of light stimulation after an overnight dark adaptation resulted in strongly induced Fos expression in supra- and infragranular layers of cat primary visual cortex. Short-term monocular deprivation changed the Fos expression profile into a columnar immunostaining related to ocular dominance columns. Fos expression has also been analyzed in cats in which visual input was confined to the right hemisphere by sectioning the left optic tract and the corpus callosum. In the right hemisphere, visual stimulation elicited Fos induction, whereas in the contralateral hemisphere a very low Fos signal was observed. The specificity of this newly synthesized antibody was confirmed by Western blotting. To further establish the applicability of this Fos antiserum, we performed immunostaining on monkey and rat visual cortex. This new cat Fos antibody appears to be excellent for study of Fos expression as a marker for mapping neuronal activity in mammalian brain.

Animals↗
PubMed2000

Visuoperceptual impairment in multiple sclerosis patients diagnosed with neuropsychological tasks.

A comprehensive set of 31 binocular neuropsychological tasks assessing a series of spatial and non-spatial visuoperceptual abilities was used to study visuoperceptual impairment in a representative group of 49 MS-clinic patients exhibiting neither diagnosed ophthalmological afflictions nor major psychiatric diagnoses. Among these patients, true frequency rate of visuoperceptual impairment, i.e. of subjects failing four or more tasks, was estimated at 26%. The pattern of visuoperceptual impairment was non-uniform, non-selective, restricted and idiosyncratic. Only four tasks yielded significant rates of impairment. They concerned colour discrimination, the perception of the Müller-Lyer illusion and object recognition in two separate conditions. Each of the four factors identified by factor analysis had an important representative (with factor loading >0.35) among these four tasks. Failures on these tasks correlated poorly. Together, the four tasks satisfactorily predicted visuoperceptual impairment as defined by the comprehensive set of tasks (sensitivity 86.7%; specificity 81.3%), but with regard to an uncontaminated criterion, their aggregate sensitivity and specificity was only 75 and 56% respectively. Visuoperceptual neuropsychological task performance related significantly but weakly to cognitive status, physical disability and to pyramidal, cerebellar and brain stem neurological signs, and did not correlate with other clinical neurological signs, disease duration, type of MS, a history of optic neuritis, depression or medication status Multiple Sclerosis (2000) 6 241 - 254

Adult↗