Asthénie et troubles visuels chez un peintre de 48 ans

in Revue Médicale de Liège (2002), 57(12), 785-8

Tiredness is a common complaint which may have multiple causes, sometimes difficult to ascertain. As occupational activities can play a major role in the incidence of various diseases, failure to ... [more ▼]

Tiredness is a common complaint which may have multiple causes, sometimes difficult to ascertain. As occupational activities can play a major role in the incidence of various diseases, failure to investigate the patient's work history may hinder an adequate patient care. In the clinical case described hereafter, the patient symptoms could eventually be ascribed to a psycho-organic syndrome (POS) caused by the chronic exposure to organic solvents in the painting material used. This syndrome is non specific, evolves with time in an insidious manner, and, in its last stages, may cause non reversible brain damages. When facing non typical neurological symptoms in a working age adult, one has thus to consider the possibility of this diagnosis since the workers populations exposed to solvents are large in several occupations, and because the recent legal recognition in Belgium of this syndrome as an occupational disease does provide some interesting means for a better follow-up and protection of the patients concerned. [less ▲]

Changes in the arginine-vasopressin immunoreactive systems in male mice lacking a functional aromatase gene

in Journal of Neuroendocrinology (2002), 14(12), 971-978

In male rodents, the arginine-vasopressin-immunoreactive (AVP-ir) neurones of the bed nucleus of the stria terminalis (BNST) and medial amygdala are controlled by plasma testosterone levels (decreased ... [more ▼]

In male rodents, the arginine-vasopressin-immunoreactive (AVP-ir) neurones of the bed nucleus of the stria terminalis (BNST) and medial amygdala are controlled by plasma testosterone levels (decreased after castration and restored by exogenous testosterone). AVP transcription in these nuclei is increased in adulthood by a synergistic action of the androgenic and oestrogenic metabolites of testosterone and, accordingly, androgen and oestrogen receptors are present in both BNST and medial amygdala. We used knockout mice lacking a functional aromatase enzyme (ArKO) to investigate the effects of a chronic depletion of oestrogens on the sexually dimorphic AVP system. Wild-type (WT) and ArKO male mice were perfused 48 h after an i.c.v. colchicine injection and brain sections were then processed for AVP immunocytochemistry. A prominent decrease (but not a complete suppression) of AVP-ir structures was observed in the BNST and medial amygdala of ArKO mice by comparison with the WT. Similarly, AVP-ir fibres were reduced in the lateral septum of ArKO mice and but not in the medial preoptic area, a region where the AVP system is not sexually dimorphic in rats. No change was detected in the supraoptic and suprachiasmatic nuclei. However, a decrease in AVP-ir cell numbers was however, detected in one subregion of the paraventricular nucleus. These data support the hypothesis that the steroid-sensitive sexually dimorphic AVP system of the mouse forebrain is mainly under the control of aromatized metabolites of testosterone. [less ▲]

Macrophage migration inhibitory factor (MIF) expression in human glioblastomas correlates with vascular endothelial growth factor (VEGF) expression

in Neuropathology & Applied Neurobiology (2002), 28(6), 452-460

Macrophage migration inhibitory factor (MIF) is a peptide released upon hypothalamo-pituitary stimulation that acts as a potent endogenous antagonist of the glucocorticoid inhibition of acute inflammatory ... [more ▼]

Macrophage migration inhibitory factor (MIF) is a peptide released upon hypothalamo-pituitary stimulation that acts as a potent endogenous antagonist of the glucocorticoid inhibition of acute inflammatory response and subsequent antigen-specific response. MIF also sustains tumour growth as it promotes angiogenesis, overcomes p53-mediated cell growth arrest and inhibits tumour-specific immune responses. Using quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry, we studied MIF expression in 35 human glioblastomas and two normal brains. We compared these results with the expression of vascular endothelial growth factor (VEGF), the most potent angiogenic factor in glioblastomas. We detected MIF in normal cortical neurons and glial cells. All glioblastomas were positive for MIF mRNA with expression levels similar to or higher than those of normal brain. MIF immunoreactivity was seen mainly in tumour cells and less frequently in hyperplastic endothelial cells. The expressions of MIF and VEGF mRNA were strongly correlated (P < 0.0001). Our results demonstrate the expression of MIF in human glioblastomas, and indicate a close relationship with VEGF expression. This is of particular interest given the potential modulation of MIF by glucocorticosteroids. [less ▲]

Increased expression of the putative axon growth-repulsive extracellular matrix molecule, keratan sulphate proteoglycan, following traumatic injury of the adult rat spinal cord

in Acta Neuropathologica (2002), 104(6), 592-600

Keratan sulphate proteoglycan (KSPG) is a developmentally regulated barrier molecule, directing axonal growth during central nervous system (CNS) formation. The possible re-expression and functional ... [more ▼]

Keratan sulphate proteoglycan (KSPG) is a developmentally regulated barrier molecule, directing axonal growth during central nervous system (CNS) formation. The possible re-expression and functional significance of KSPG in preventing axon regeneration following spinal cord injury (SCI) is poorly understood. In the present investigation, the spatio-temporal expression of KSPG was studied following experimental SCI. There was no indication of sparing of axons at the lesion epicentre following severe compression injury. By 7 days post operation (p.o.) a diffuse increase of KSPG immunoreactivity (KSPG-IR) was observed in the parenchyma surrounding the lesion. This was followed by a delayed (21-28 days p.o.) and largely heterogeneous increase of KSPG-IR in the lesion epicentre, which revealed both cellular and extracellular matrix-like distribution patterns. Although no re-growth of anterogradely labelled corticospinal axons was observed, many 200-kDa neurofilament (NF)-positive axon could be detected growing into the connective tissue scar. This phase of spontaneous axonal re-growth was closely associated with a framework of glial cells (including Schwann cells from damaged local spinal nerve roots) that had migrated into the lesion site. The spontaneous nerve fibre re-growth could be detected in both KSPG-rich and KSPG-poor territories. The present data suggest that the lesion-induced up-regulation of KSPG-IR may have contributed to the lack of corticospinal axon re-growth. However, the lack of any direct spatio-temporal correlation between the distribution of raised KSPG-IR and spontaneous NF-positive axonal regeneration suggests that at least some populations of axons can resist the putative inhibitory effects of this extracellular matrix molecule. [less ▲]

Optimization of the separation of beta-blockers by ion-pair capillary electrophoresis in non-aqueous media using univariate and multivariate approaches

in Journal of Separation Science (2002), 25(15-17), 1087-1095

The separation of four beta-blocking drug substances (atenolol, sotalol, betaxolol, and metoprolol) selected as model basic analytes has been investigated in non-aqueous capillary electrophoresis (NACE ... [more ▼]

The separation of four beta-blocking drug substances (atenolol, sotalol, betaxolol, and metoprolol) selected as model basic analytes has been investigated in non-aqueous capillary electrophoresis (NACE) using the principle of ion-pair formation. Camphorsulphonate was selected as the counter-ion in a background electrolyte (BGE) made up of formate buffer in a mixture of acetonitrile/methanol or acetonitrile/ethanol. The influence on resolution of the concentration of the counter-ion, the nature and proportion of the organic solvents, as well as the concentration of the ionic components of the BGE was first studied by a univariate approach. An experimental design was then applied to estimate possible quadratic effects and first-order interactions. To identify the most important factors affecting the separation of the four beta-blockers, a two-level fractional factorial design with 16 experimental points was applied as a screening test. A three factor Box-Behnken design with 12 experimental points was used to predict and optimize the selectivity. Finally the optimal conditions obtained by the univariate and the multivariate, approaches were compared. [less ▲]

Site effect analysis around the seismically induced Ananevo, Rockslide, Kyrgyzstan

in Bulletin of the Seismological Society of America (2002), 92(8), 3190-3209

In 1911, the surface-wave magnitude 8.2 Kemin earthquake hit northeastern Tien Shan (Kyrgyzstan), close to the cities of Bishkek and Almaty, the capitals of Kyrgyzstan and Kazakhstan, respectively ... [more ▼]

In 1911, the surface-wave magnitude 8.2 Kemin earthquake hit northeastern Tien Shan (Kyrgyzstan), close to the cities of Bishkek and Almaty, the capitals of Kyrgyzstan and Kazakhstan, respectively. Several hundreds of people were killed by the earthquake, some by indirect effects such as landslides and mudflows. A particular but nonfatal landslide triggered by the Kemin event was a rockslide in the vicinity of Ananevo, north of lake Issyk Kul (Kyrgyzstan) rockslide located above the fault zone activated in 1911. In the summer of 1999, a geophysical-seismological field trip was organized to study geology and to record seismic ground motions on and around the Ananevo rockslide. The work was part of project assessing seismogenic landslide hazard in northern Kyrgyzstan, based on various case studies of slope failures in connection with site-specific ground-motion dynamics. The geophysical investigations consisted of seismic refraction tests processed as 2D seismic tomographies and surface-wave inversion, which were combined to build a 3D geophysical model of the landslide site. Ground motions from small earthquakes were analyzed using several techniques to define site effects over the mountain massif. Both H/V and standard spectral ratios indicated lower dominant frequencies with stronger amplification in the crest region with respect to the mountain slope. These effects could be partially simulated by I D, 2D, and 3D finite-element modeling. By comparing the numerical results with the experimental data, the presence of a surficial low-velocity layer of varying thickness appeared to be the key factor controlling the ground motion around the rockslide. [less ▲]

The north-eastern Polish anorthosite massifs: petrological, geochemical and isotopic evidence for a crustal derivation

in Terra Nova (2002), 14(6), 451-460

Deeply buried 1.5 Ga Polish anorthosites, accessible only by bore holes, reveal diagnostic features of some massif-type anorthosites (polybarism, jotunitic parent magma), diapirically emplaced in the mid ... [more ▼]

Deeply buried 1.5 Ga Polish anorthosites, accessible only by bore holes, reveal diagnostic features of some massif-type anorthosites (polybarism, jotunitic parent magma), diapirically emplaced in the mid crust together with the rapakivi granites of the EW-trending Mazury complex, intruded along a major crustal discontinuity. Geochemical modelling and isotope data corroborate recent experimental work on the basaltic system in dry conditions: the source rock of the parental magma is a gabbronorite, necessarily lying in the lower crust. Since no Archaean crust is known in the region, high initial Os-188/Os-187 ratios for sulphide-oxide isochrons and negative epsilon(Nd) values are best accounted for by melting a similar to 2.0 Ga mafic crust. [less ▲]

Le Secret des Géants

Scientific conference (2002, December)

L'Intérêt herpétologique des gares de triage de l'Entre-Sambre-et-Meuse (Belgique)

in Natura Mosana (2002), 55(4), 63-69

Use of simulation in the commissioning of an office building

in Proceedings of SSB'2002 congress (2002, December)

In the frame of two successive IEA-ECBCS annexes, the « CA-MET » building in Namur was the object of commissioning and re-commissioning activities. First, during the construction of the building and ... [more ▼]

In the frame of two successive IEA-ECBCS annexes, the « CA-MET » building in Namur was the object of commissioning and re-commissioning activities. First, during the construction of the building and installation of the HVAC plant, a systematic survey of the work was carried out in the frame of IEA Annex 34 (“Fault Detection”). Therefore, attention was paid to a specific part of the plant (a typical Air handling Unit) and a number of testing and verifications were performed, as a complement to the normal and ongoing commissioning activities: - testing and balancing of air and water networks - air flowrate measurements - water flowrate measurements - control system analysis The most important faults identified in this part of the project were classified according to the IEA 34 template and, for each of these faults, the possibility of developing an automatic fault detection method was analysed. The paper will report on the most relevant problems and present the automatic fault detection method proposed. In a second step, which occurred during in the early stages of the operational phase of the building, a further verification of specific subsystems was carried out, as part of a re-commissioning activity. This work is being realized in the frame of IEA Annex 40 and ends up with a proposal of systematic verification procedure to be applied, as a first example, to a VAV system. This procedure follows a hierarchical approach (bottom-up), starting with the local VAV loop, going through the AHU and ending with the chilled water production equipment. The paper reports on the application of the procedure to the selected building and will be based upon experimental results obtained during target monitoring campaigns. [less ▲]