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See detailMembrane type-1 matrix metalloproteinase and TIMP-2 in tumor angiogenesis
Sounni, Nor Eddine ULg; Janssen, M.; Foidart, Jean-Michel ULg et al

in Matrix Biology (2003), 22(1), 55-61

The matrix metalloproteinases (MMPs) constitute a multigene family of over 23 secreted and cell-surface associated enzymes that cleave or degrade various pericellular substrates. In addition to virtually ... [more ▼]

The matrix metalloproteinases (MMPs) constitute a multigene family of over 23 secreted and cell-surface associated enzymes that cleave or degrade various pericellular substrates. In addition to virtually all extracellular matrix (ECM) compounds, their targets include other proteinases, chemotactic molecules, latent growth factors, growth factor-binding proteins and cell surface molecules. The MMP activity is controlled by the physiological tissue inhibitors of MMPs (TIMPs). There is much evidence that MMPs and their inhibitors play a key role during extracellular remodeling in physiological situations and in cancer progression. They have other functions that promoting tumor invasion. Indeed, they regulate early stages of tumor progression such as tumor growth and angiogenesis. Membrane type MMPs (MT-MMPs) constitute a new subset of cell surface-associated MMPs. The present review will focus on MT1-MMP which plays a major role at least, in the ECM remodeling, directly by degrading several of its components, and indirectly by activating pro-MMP2. As our knowledge on the field of MT1-MMP biology has grown, the unforeseen complexities of this enzyme and its interaction with its inhibitor TIMP-2 have emerged, often revealing unexpected mechanisms of action. (C) 2003 Elsevier Science B.V/Intemational Society of Matrix Biology. All rights reserved. [less ▲]

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See detailAdhesion of endometrial cells labeled with 111 Indium-tropolonate to peritoneum: a novel in vitro model to study endometriosis
Beliard, Aude ULg; Noël, Agnès ULg; Goffin, Frédéric ULg et al

in Fertility and Sterility (2003), 79(Suppl. 1), 724-729

Objective: To evaluate, in a new original in vitro assay, putative factors that could modulate the adhesion of endometrial cells to peritoneum. Design: Prospective, controlled in vitro study. Setting ... [more ▼]

Objective: To evaluate, in a new original in vitro assay, putative factors that could modulate the adhesion of endometrial cells to peritoneum. Design: Prospective, controlled in vitro study. Setting: Academic research laboratory. Patient(s): Fourteen nonmenopausal women undergoing hysterectomy or laparoscopy for benign gynecologic indication. Intervention(s): Endometrial cells obtained from women with regular cycles without endometriosis were labeled with (111)Indium and confronted in vitro with mouse peritoneum in the presence of various cytokines and/or antiadhesive compounds. Main Outcome Measure(s): Radioactivity in (111)Indium-labeled endometrial cells. Result(s): The adhesion of human endometrial cells to mouse peritoneum was increased by treatment with pro-inflammatory cytokines (interleukin IL-1 beta, IL-6, TNF alpha, TGF-beta1). Whereas heparan sulfate had no effect on cell adhesion, a gel of ferric hyaluronate (Intergel) was able to counteract the pro-adhesive effect of cytokines. Interestingly, the pretreatment of peritoneum with cytokines, 24 hours before cell seeding in the presence of the ferric hyaluronate gel, restored the cytokine-promoting effect on cell adhesion. Conclusion(s): Proinflammatory cytokines promote the in vitro peritoneal adhesion of endometrial cells. An antiadhesive hyaluronate gel used in clinics decreases the adhesion in a dose-dependent manner and reduces cytokine bioavailability. (Fertil Steril((R)) 2003;79(Suppl 1):724-9. (C) 2003 by American Society for Reproductive Medicine.). [less ▲]

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See detailJeunesse, quartiers, violence : pour une politique de prévention intégrée
Comeron, Manuel ULg

in Manuel de la Police (2003), (67), 166

La violence juvénile, particulièrement dans les quartiers, constitue un problème majeur de sécurité urbaine. A l'éclairage des travaux scientifiques sur la déviance sociale et la délinquance juvénile, les ... [more ▼]

La violence juvénile, particulièrement dans les quartiers, constitue un problème majeur de sécurité urbaine. A l'éclairage des travaux scientifiques sur la déviance sociale et la délinquance juvénile, les intervenants sociaux et services de police construisent des actions communes afin de proposer une réponse préventive intégrée. [less ▲]

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See detailA comparison of voluntary and electrically induced contractions by interleaved H-1- and P-31-NMRS in humans
Vanderthommen, Marc ULg; Duteil, S.; Wary, C. et al

in Journal of Applied Physiology (2003), 94(3), 1012-1024

Skeletal muscle voluntary contractions (VC) and electrical stimulations (ES) were compared in eight healthy men. High-energy phosphates and myoglobin oxygenation were simultaneously monitored in the ... [more ▼]

Skeletal muscle voluntary contractions (VC) and electrical stimulations (ES) were compared in eight healthy men. High-energy phosphates and myoglobin oxygenation were simultaneously monitored in the quadriceps by interleaved H-1- and P-31-NMR spectroscopy. For the VC protocol, subjects performed five or six bouts of 5 min with a workload increment of 10% of maximal voluntary torque (MVT) at each step. The ES protocol consisted of a 13-min exercise with a load corresponding to 10% MVT. For both protocols, exercise consisted of 6-s isometric contractions and 6-s rest cycles. For an identical mechanical level (10% MVT), ES induced larger changes than VC in the P-i-to-phosphocreatine ratio [1.38 +/- 1.14 (ES) vs. 0.13 +/- 0.04 (VC)], pH [6.69 +/- 0.11 (ES) vs. 7.04 +/- 0.07 (VC)] and myoglobin desaturation [43 +/- 15.9 (ES) vs. 6.1 +/- 4.6% (VC)]. ES activated the muscle facing the NMR coil to a greater extent than did VCs when evaluated under identical technical conditions. This metabolic pattern can be interpreted in terms of specific temporal and spatial muscle cell recruitment. Furthermore, at identical levels of energy charge, the muscle was more acidotic and cytoplasm appeared more oxygenated during ES than during VC. These results are in accordance with a preferential recruitment of type II fibers and a relative muscle hyperperfusion during ES. [less ▲]

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See detailImage analysis of the axonal ingrowth into poly(D,L-lactide) porous scaffolds in relation to the 3-D porous structure
Blacher, Silvia ULg; Maquet, Véronique; Luyckx, Françoise ULg et al

in Biomaterials (2003), 24(6), 1033-1040

Porous polymer scaffolds are promising materials for neural tissue engineering because they offer valuable three-dimensional (3D) supports for the in vitro and in vivo axonal growth and tissue expansion ... [more ▼]

Porous polymer scaffolds are promising materials for neural tissue engineering because they offer valuable three-dimensional (3D) supports for the in vitro and in vivo axonal growth and tissue expansion. At the time being, how the in vivo neuronal cell development depends on the scaffold 3-D architecture is unknown. Therefore, scanning electron micrographs of longitudinal sections of porous polylactide scaffolds and immunohistological sections of these scaffolds after implantation and neurofilament staining have been studied by image analysis. Pore orientation and axonal ingrowth have been investigated by spectral analysis on gray level SEM images. Binary image processing has been carried out and the binary images have been studied by spectral analysis in order to estimate the possible effect of the image noise on the real pattern. In addition to axonal orientation, density and length distribution of the regenerated axons into the polymer scaffold have been measured. Dependence of the axonal ingrowth on the 3D-polymer scaffold has been discussed on the basis of the collected data. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailOzone et asthme: un couple dans l'air du temps
Kleis, S.; Louis, Renaud ULg; Bartsch, Pierre ULg

in Revue Médicale de Liège (2003), 58(3), 132-8

Ozone is a pollutant the production of which depends on weather conditions and car engine combustion. Numerous epidemiological studies have indicated that high ozone levels correlated with morbidity in ... [more ▼]

Ozone is a pollutant the production of which depends on weather conditions and car engine combustion. Numerous epidemiological studies have indicated that high ozone levels correlated with morbidity in asthma. Experimental studies have shown that exposure of healthy subjects and asthmatics to ozone levels comparable to those measured in ambient air during hot summer days can generate respiratory symptoms, neutrophilic airways inflammation and lung function impairment. Lung function changes following ozone exposure are more pronounced in asthmatics and are dependent on the duration and intensity of exposure, a previous exposure and the nutritional status of the subjects. The airway epithelial cell layer is likely to play a pivotal role in initiating the inflammatory process following ozone exposure. Control of ambient air ozone levels must be a target for public health authorities. [less ▲]

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See detailPolymer/layered silicate nanocomposites by combined intercalative polymerization and melt intercalation: a masterbatch process
Lepoittevin, Bénédicte; Pantoustier, Nadège; Devalckenaere, Myriam et al

in Polymer (2003), 44(7), 2033-2040

Poly(ε-caprolactone) (PCL) and poly(vinyl chloride) (PVC) layered silicate nanocomposites were prepared by combination of intercalative polymerization and melt intercalation. In a first step, high clay ... [more ▼]

Poly(ε-caprolactone) (PCL) and poly(vinyl chloride) (PVC) layered silicate nanocomposites were prepared by combination of intercalative polymerization and melt intercalation. In a first step, high clay content PCL nanocomposites were prepared by in situ polymerization of -caprolactone intercalated between selected organo-modified silicate layers. The polymerization was catalyzed with dibutyltin dimethoxide in the presence of montmorillonites, the surface of which were previously exchanged with (functionalized) long alkyl chains ammonium cations. Then, these highly filled PCL nanocomposites were added as masterbatches in commercial PCL and PVC by melt blending. The intercalation of PCL chains within the silicate layers by in situ polymerization proved to be very efficient, leading to the formation of intercalated and/or exfoliated structures depending on the organo-clay. These masterbatches were readily dispersed into the molten PCL and PVC matrices yielding intercalated/exfoliated layered silicate nanocomposites which could not be obtained by melt blending the matrix directly with the same organo-modified clays. The formation of nanocomposites was assessed both by X-ray diffraction and transmission electronic microscopy. Interestingly, this so-called 'masterbatch' two-step process allowed for preparing PCL nanocomposites even with non-modified natural clay, i.e. sodium montmorillonite, which showed a material stiffness much higher than the corresponding microcomposites recovered by direct melt intercalation. The thermal stability of PCL nanocomposites as a function of clay content was investigated by thermogravimetry (TGA). [less ▲]

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See detailSensation-seeking and impulsivity in young and older adults' decision making
Willems, Sylvie ULg; Van der Linden, Martial ULg; Marczewski, Philippe

in Brain & Cognition (2003), 51(2), 237-239

The somatic marker hypothesis asserts that decision-making processes involve emotion. Using a gambling task that models real-life decisions, studies showed that old adults perform less efficiently than ... [more ▼]

The somatic marker hypothesis asserts that decision-making processes involve emotion. Using a gambling task that models real-life decisions, studies showed that old adults perform less efficiently than younger adults, by adopting a strategy that is disadvantageous on the long term. This study aimed at re-examining the age effect on decisionmaking with the same paradigm, and to explore whether differences are related to sensation-seeking and impulsivity traits of personality. Young and older adults were compared on the gambling task (Bechara, Damasio, & Damasio, 2000a), and on questionnaires of sensationseeking and impulsivity. Results confirmed an age effect on the gambling task performance. Moreover, performance in both young and older adults on this task was correlated to scores on the sensation-seeking scale, but not to the rating of impulsivity [less ▲]

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See detailStates of awareness associated with memory for emotional and neutral pictures in older and younger adults
D'Argembeau, Arnaud ULg; Comblain, Christine; Van der Linden, Martial ULg et al

in Brain & Cognition (2003, March), 51(2), 220-221

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See detailAdéquation entre les formations existantes en éducation physique, les motivations des étudiants et les différents débouchés professionnels.
Carlier, Ghislain; Gaspard, Laurent; Gérard, Philippe et al

in Point sur la Recherche en Education (Le) (2003), 27

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See detailRole of plasminogen activator-plasmin system in tumor angiogenesis
Rakic, Jean-Marie ULg; Maillard, Catherine ULg; Jost, M. et al

in Cellular and Molecular Life Sciences : CMLS (2003), 60(3), 463-473

New blood formation or angiogenesis has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization. Angiogenesis is associated ... [more ▼]

New blood formation or angiogenesis has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization. Angiogenesis is associated with important extracellular remodeling involving different proteolytic systems among which the plasminogen system plays an essential role. It belongs to the large serine proteinase family and can act directly or indirectly by activating matrix metalloproteinases or by liberating growth factors and cytokines sequestered within the extracellular matrix. Migration of endothelial cells is associated with significant upregulation of proteolysis and, conversely, immunoneutralization or chemical inhibition of the system reduces angiogenesis in vitro. On the other hand, genetically altered mice developed normally without overt vascular anomalies indicating the possibility of compensation by other proteases in vivo. Nevertheless, they have in some experimental settings revealed unanticipated roles for previously characterized proteinases or their inhibitors. In this review, the complex mechanisms of action of the serine proteases in pathological angiogenesis are summarized alongside possible therapeutic applications. [less ▲]

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See detailModeling of Electro-Mechanical Coupling Problem using the Finite Element Formulation
Rochus, Véronique ULg; Rixen, Daniel J.; Golinval, Jean-Claude ULg

Conference given outside the academic context (2003)

A modeling procedure is proposed to handle strong electro-mechanical coupling appearing in micro-electromechanical systems (MEMS). The finite element method is used to discretize simultaneously the ... [more ▼]

A modeling procedure is proposed to handle strong electro-mechanical coupling appearing in micro-electromechanical systems (MEMS). The finite element method is used to discretize simultaneously the electrostatic and mechanical fields. The formulation is consistently derived from variational principles based on the electromechanical free energy. In classical weakly coupled formulations staggered iteration is used between the electrostatic and the mechanical domain. Therefore, in those approaches, linear stiffness is evaluated by finite differences and equilibrium is reached typically by relaxation techniques. The strong coupling formulation presented here allows to derive exact tangent matrices of the electro-mechanical system. Thus it allows to compute non-linear equilibrium positions using Newton-Raphson type of iterations combined with adaptive meshing in case of large displacements. Furthermore, the tangent matrix obtained in the method exposed in this paper greatly simplifies the computation of vibration modes and frequencies of the cou pled system around equilibrium configurations. The non-linear variation of frequencies with respect to voltage and stiffness can be then be investigated until pull-in appears. In order to illustrate the effectiveness of the proposed formulation numerical results are shown first for the reference problem of a simple flexible capacitor, then for the model of a micro-bridge. [less ▲]

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See detailIsokinetic evaluation of muscular function in patients with chronic pain and fatigability
Maquet, Didier ULg; Croisier, Jean-Louis ULg; Moutschen, Michel ULg et al

in Isokinetics & Exercise Science (2003, March), 11(1), 73-74

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See detailNear Optimal Closed-Loop Control. Application to Electric Power Systems
Ernst, Damien ULg

Doctoral thesis (2003)

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See detailMexiko: (De-)Konstruktion von Nation und Ethnie im Diskurs der Guerilla
Vanden Berghe, Kristine ULg; Maddens, Bart

in WeltTrends : Zeitschrift für internationale Politik und vergleichende Studien. (2003), 38

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See detailRegulation of the alternative oxidase Aox1 gene in Chlamydomonas reinhardtii. Role of the nitrogen source on the expression of a reporter gene under the control of the Aox1 promoter
Baurain, Denis ULg; Dinant, Monique; Coosemans, Nadine ULg et al

in Plant Physiology (2003), 131(3), 1418-1430

In higher plants, various developmental and environmental conditions enhance expression of the alternative oxidase (AOX), whereas its induction in fungi is mainly dependent on cytochrome pathway ... [more ▼]

In higher plants, various developmental and environmental conditions enhance expression of the alternative oxidase (AOX), whereas its induction in fungi is mainly dependent on cytochrome pathway restriction and triggering by reactive oxygen species. The AOX of the unicellular green alga Chlamydomonas reinhardtii is encoded by two different genes, the Aox1 gene being much more transcribed than Aox2. To analyze the transcriptional regulation of Aox1, we have fused its 1.4-kb promoter region to the promoterless arylsulfatase (Ars) reporter gene and measured ARS enzyme activities in transformants carrying the chimeric construct. We show that the Aox1 promoter is generally unresponsive to a number of known AOX inducers, including stress agents, respiratory inhibitors, and metabolites, possibly because the AOX activity is constitutively high in the alga. In contrast, the Aox1 expression is strongly dependent on the nitrogen source, being down-regulated by ammonium and stimulated by nitrate. Inactivation of nitrate reductase leads to a further increase of expression. The stimulation by nitrate also occurs at the AOX protein and respiratory levels. A deletion analysis of the Aox1 promoter region demonstrates that a short upstream segment (-253 to +59 with respect to the transcription start site) is sufficient to ensure gene expression and regulation, but that distal elements are required for full gene expression. The observed pattern of AOX regulation points to the possible interaction between chloroplast and mitochondria in relation to a potential increase of photogenerated ATP when nitrate is used as a nitrogen source. [less ▲]

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See detailWork environment changes and stress. The role of work to family conflict
De Zanet, Fabrice ULg; Stinglhamber, Florence; Vandenberghe, Christian et al

Conference (2003, March)

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See detailReconstruire la ville sur la ville - Recyclage des espaces dégradés
Govaerts, P.; Timmermans, A.; Vanloqueren, T. et al

Report (2003)

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See detailProposal for the assessment protocols for different shoulder muscles groups
Forthomme, Bénédicte ULg; Croisier, Jean-Louis ULg; Crielaard, Jean-Michel ULg

in Isokinetics & Exercise Science (2003, March), 11

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See detailThe structure of a cold-adapted family 8 xylanase at 1.3 angstrom resolution - Structural adaptations to cold and investigation of the active site
Van Petegem, F.; Collins, T.; Meuwis, Marie-Alice ULg et al

in Journal of Biological Chemistry (2003), 278(9), 7531-7539

Enzymes from psychrophilic organisms differ from their mesophilic counterparts in having a lower thermo-stability and a higher specific activity at low and moderate temperatures. The current consensus is ... [more ▼]

Enzymes from psychrophilic organisms differ from their mesophilic counterparts in having a lower thermo-stability and a higher specific activity at low and moderate temperatures. The current consensus is that they have an increased flexibility, enhancing accommodation and transformation of the substrates at low energy costs. Here we describe the structure of the xylanase from the Antarctic bacterium Pseudoalteromonas haloplanktis at 1.3 Angstrom resolution. Xylanases are usually grouped into glycosyl hydrolase families 10 and 11, but this enzyme belongs to family 8. The fold differs from that of other known xylanases and can be described as an (alpha/alpha)(6) barrel. Various parameters that may explain the cold-adapted properties were examined and indicated that the protein has a reduced number of salt bridges and an increased exposure of hydrophobic residues. The crystal structures of a complex with xylobiose and of mutant D144N were obtained at 1.2 and 1.5 A resolution, respectively. Analysis of the various substrate binding sites shows that the +3 and -3 subsites are rearranged as compared to those of a family 8 homolog, while the xylobiose complex suggests the existence of a +4 subsite. A decreased acidity of the substrate binding cleft and an increased flexibility of aromatic residues lining the subsites may enhance the rate at which substrate is bound. [less ▲]

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