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See detailDown-Regulation of MT1-MMP expression by the alpha3 chain of type IV collagen inhibits bronchial tumor cell line invasion
Martinella-Catusse, C.; Polette, M.; Noël, Agnès ULg et al

in Laboratory Investigation : Journal of Technical Methods & Pathology (2001), 81

The basement membrane (BM) is the first barrier encountered by tumor cells when they become invasive. Moreover, some invasive tumor clusters are surrounded by a remnant or neosynthetized BM material. We ... [more ▼]

The basement membrane (BM) is the first barrier encountered by tumor cells when they become invasive. Moreover, some invasive tumor clusters are surrounded by a remnant or neosynthetized BM material. We have previously reported the presence of a particular alpha chain of type IV collagen, the alpha3(IV) chain, in bronchopulmonary carcinomas. This chain was not detected in the normal bronchial epithelium, but was found around some invasive tumor cluster BM. In the present study, we examined the effects of the alpha3(IV) chain on the invasive properties of bronchial tumor cell lines, with special emphasis on their expression of matrix metalloproteinase-2 (MMP-2) and its activator, membrane type 1-matrix metalloproteinase (MT1-MMP), which is largely involved in tumor progression. Two epithelial bronchial cell lines (16HBE14o- and BZR), showing different invasive abilities, were evaluated. Using the Boyden chamber invasion assay, we demonstrated that the alpha3(IV) chain inhibits the invasive properties of BZR cells and modifies their morphology by inducing an epithelial cell shape. In the presence of the recombinant NC1 domain of the alpha3(IV) chain, the expression of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) was not modified in either cell line. The NC1 alpha3(IV) domain did not modulate the MT1-MMP expression of noninvasive 16HBE14o- cells, whereas a 50% decrease of MT1-MMP mRNA was observed in invasive BZR cells. Accordingly, Western blot analyses showed a disappearance of the 45-kd MT1-MMP form when BZR cells were treated with the recombinant NC1 alpha3(IV) domain. These findings suggest that the alpha3 chain of type IV collagen may play a role in tumor invasion, at least by decreasing the expression and synthesis of MT1-MMP. [less ▲]

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See detailDown-Regulation of Vascular Endothelial Growth Factor by Tissue Inhibitor of Metalloproteinase-2: Effect on in Vivo Mammary Tumor Growth and Angiogenesis
Hajitou, Amin; Sounni, Nor Eddine ULg; Devy, Laetitia et al

in Cancer Research (2001), 61(8), 3450-7

The tissue inhibitor of metalloproteinases-2 (TIMP-2) has at least two independent functions, i.e., regulation of matrix metalloproteinases and growth promoting activity. We investigated the effects of ... [more ▼]

The tissue inhibitor of metalloproteinases-2 (TIMP-2) has at least two independent functions, i.e., regulation of matrix metalloproteinases and growth promoting activity. We investigated the effects of TIMP-2 overexpression, induced by retroviral mediated gene transfer, on the in vivo development of mammary tumors in syngeneic mice inoculated with EF43.fgf-4 cells. The EF43.fgf-4 cells established by stably infecting the normal mouse mammary EF43 cells with a retroviral expression vector for the fgf-4 oncogene, are highly tumorigenic and overproduce vascular endothelial growth factor (VEGF). Despite a promotion of the in vitro growth rate of EF43.fgf-4 cells overexpressing timp-2, the in vivo tumor growth was delayed. At day 17 post-cell injection, the volume of tumor derived from TIMP-2-overexpressing cells was reduced by 80% as compared with that obtained with control cells. Overexpression of TIMP-2 was associated with a down-regulation of VEGF expression in vitro and in vivo, a reduction of vessel size, density, and blood supply in the induced tumors. In addition, TIMP-2 completely inhibited the angiogenic activity of EF43.fgf-4 cell-conditioned medium in vitro using a rat aortic ring model. Our findings suggest that overexpression of TIMP-2 delays growth and angiogenesis of mammary carcinoma in vivo and that down-regulation of VEGF expression may play an important role in this TIMP-2-mediated antitumoral and antiangiogenic effects. Finally the in vivo delivery of TIMP-2, as assessed by i.v. injection of recombinant adenoviruses vectors, significantly reduced the growth of the EF43.fgf-4-induced tumors. This effect of TIMP-2 was shown to be equally comparable with that of angiostatin, a known potent inhibitor of angiogenesis. [less ▲]

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See detailDowngrading skin climacteric aging by hormone replacement therapy.
Quatresooz, Pascale ULg; Pierard, Gérald ULg

in Expert Review of Dermatology (2007), 2

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See detailDownmodulator role of SHIP-1 in NOD2 signaling
Condé, Claude ULg

Doctoral thesis (2012)

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See detailDownregulation of CD94/NKG2A inhibitory receptors on CD8+ T cells in HIV infection is more pronounced in subjects with detected viral load than in their aviraemic counterparts.
Zeddou, Mustapha ULg; Rahmouni, Souad ULg; Vandamme, Arnaud ULg et al

in Retrovirology (2007), 4

The CD94/NKG2A heterodimer is a natural killer receptor (NKR), which inhibits cell-mediated cytotoxicity upon interaction with MHC class I gene products. It is expressed by NK cells and by a small ... [more ▼]

The CD94/NKG2A heterodimer is a natural killer receptor (NKR), which inhibits cell-mediated cytotoxicity upon interaction with MHC class I gene products. It is expressed by NK cells and by a small fraction of activated CD8+ T lymphocytes. Abnormal upregulation of the CD94/NKG2A inhibitory NKR on cytotoxic T cells (CTLs) could be responsible for a failure of immunosurveillance in cancer or HIV infection. In this study, CD94/NKG2A receptor expression on CD8+ T lymphocytes and NK cells was assessed in 46 HIV-1-infected patients (24 viraemic, 22 aviraemic) and 10 healthy volunteers. The percentage of CD8+ T lymphocytes expressing the CD94/NKG2A inhibitory heterodimer was very significantly decreased in HIV-1-infected patients in comparison with non-infected controls. Within the HIV infected patients, the proportion of CD8+ T lymphocytes and NK cells expressing CD94/NKG2A was higher in subjects with undetectable viral loads in comparison with their viraemic counterparts. No significant difference was detected in the proportion of CD8+ T lymphocytes expressing the activatory CD94/NKG2C heterodimer between the HIV-1 infected patients and the healthy donors, nor between the vireamic and avireamic HIV-1 infected patients. In conclusion, chronic stimulation with HIV antigens in viraemic patients leads to a decreased rather than increased CD94/NKG2A expression on CD8+ T lymphocytes and NK cells. [less ▲]

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See detailDownregulation of ICAM-1 and VCAM-1 expression in endothelial cells treated by photodynamic therapy
Volanti, Cédric ULg; Gloire, Geoffrey ULg; Vanderplasschen, Alain ULg et al

in Oncogene (2004), 23(53), 8649-8658

Photodynamic therapy (PDT) is a treatment for cancer and several noncancerous proliferating cell diseases that depends on the uptake of a photosensitizing compound followed by selective irradiation with ... [more ▼]

Photodynamic therapy (PDT) is a treatment for cancer and several noncancerous proliferating cell diseases that depends on the uptake of a photosensitizing compound followed by selective irradiation with visible light. In the presence of oxygen, irradiation leads to the production of reactive oxygen species (ROS). A large production of ROS induces the death of cancer cells by apoptosis or necrosis. A small ROS production can activate various cellular pathways. Here, we show that PDT by pyropheophorbide-a methyl ester (PPME) induces the activation of nuclear factor kappa B (NF-kappaB) in HMEC-1 cells. NF-kappaB is active since it binds to the NF-kappaB sites of both ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1) promoters and induces the transcription of several NF-kappaB target genes such as those of IL-6, ICAM-1, VCAM-1. In contrast, expression of ICAM-1 and VCAM-1 at the protein level was not observed, although we measured an IL-6 secretion. Using specific chemical inhibitors, we showed that the lack of ICAM-1 and VCAM-1 expression is the consequence of their degradation by lysosomal proteases. The proteasome and calpain pathways were not involved. All these observations were consistent with the fact that no adhesion of granulocytes was observed in these conditions. [less ▲]

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See detailA Downscaling Approach Toward High-resolution Surface Mass Balance Over Antarctica
Gallée, Hubert; Agosta, Cécile ULg; Gential, Luc et al

in Surveys in Geophysics (2011), 32(4-5), 507-518518

The Antarctic ice sheet surface mass balance shows high spatial variability over the coastal area. As state-of-the-art climate models usually require coarse resolutions to keep computational costs to a ... [more ▼]

The Antarctic ice sheet surface mass balance shows high spatial variability over the coastal area. As state-of-the-art climate models usually require coarse resolutions to keep computational costs to a moderate level, they miss some local features that can be captured by field measurements. The downscaling approach adopted here consists of using a cascade of atmospheric models from large scale to meso-gamma scale. A regional climate model (Modegravele Atmospheacuterique Reacutegional) forced by meteorological reanalyses provides a diagnostic physically-based rain- and snowfall downscaling model with meteorological fields at the regional scale. Although the parameterizations invoked by the downscaling model are fairly simple, the knowledge of small-scale topography significantly improves the representation of spatial variability of precipitation and therefore that of the surface mass balance. Model evaluation is carried out with the help of shallow firn cores and snow height measurements provided by automatic weather stations. Although downscaling of blowing snow still needs to be implemented in the model, the net accumulation gradient across Law Dome summit is shown to be induced mostly by orographic effects on precipitation. [less ▲]

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See detailDownscaling of ECMWF grid meteorological data : comparison with ground stations and validation
Tychon, Bernard ULg; Horion, Stéphanie

Conference (2006, October)

CGMS currently operates on observed station data. Switching from this classical approach to a modelled data from European Centre for Medium-range Weather Forecast, ECMWF, has to be tested before applying ... [more ▼]

CGMS currently operates on observed station data. Switching from this classical approach to a modelled data from European Centre for Medium-range Weather Forecast, ECMWF, has to be tested before applying it operationally. In this study, we concentrated on the impact of the downscaling of meteorological data with grid sizes ranging from 1.875 to 0.35 degrees to the new CGMS grid size of 25 X 25 km. Four different grid sizes corresponding respectively to the dimensions of the Operational, EPS, Monthly and Seasonal ECMWF Models were checked. The control was done on daily data of 25 stations selected on a 2-year period in a window covering the South of Germany and Czech Republic, a large part of Austria and the North of Italia in order to analyse the downscaling impact on plains, mountainous and coastal zones. For each grid size, four different downscaling methods were applied: the reference method that uses the classical CGMS interpolation procedure, the nearest neighbour approach, and two more complicated interpolation techniques using the Model Output Statistics developed by Meteo Consult (MC-MOS). The analysis showed that the accuracy of the downscaling procedure is largely influenced by the input data grid size. RMSE increases between the smallest and the largest grids are respectively 59%, 51%, 33%, and 33% for Tmax, Tmin, Wind Speed and Radiation fields. Rainfall does not seem to be affected by the downscaling process but the RMSE is high in all cases. In most cases, the best interpolation method is also the more complex one and the one that requires more computer time to be calculated. RMSE decrease of 22%, 50%, 57% and 28% respectively for Tmax, Tmin, Wind speed and Radiation fields when we compare the best interpolation method results with the reference approach. An exception in this general rule is for the rainfall rate estimation whose accuracy is not always best with the most complex interpolation technique. [less ▲]

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See detailDownscaling of the global HYCOM to the Cariaco basin (Venezuela) using ROMS
Alvera Azcarate, Aïda ULg; Barth, Alexander ULg; Weisberg, R. H.

Conference (2008)

A high-resolution (1/60 degree), three-dimensional numerical circulation model of the Cariaco basin (Venezuela) is constructed by nesting the Regional Ocean Modeling System (ROMS) in the 1/12 degree ... [more ▼]

A high-resolution (1/60 degree), three-dimensional numerical circulation model of the Cariaco basin (Venezuela) is constructed by nesting the Regional Ocean Modeling System (ROMS) in the 1/12 degree global Hybrid Coordinate Ocean Model (HYCOM). The Cariaco basin is a semi-enclosed trench located along the coast of Venezuela. Its maximum depth is about 1400 m, and it is connected to the open ocean by two shallow passages: the Centinela channel in the northwest (146 m depth) and the Tortuga channel in the northeast (135 m depth). The main objective of this work is to improve our knowledge of the Cariaco basin dynamics, and to understand how the basin is influenced by the Caribbean Sea. The nesting of the Cariaco model in HYCOM is therefore crucial for these analyses. First, the annual cycle of the basin is described, using the results from a 2004 hindcast. Then, two modes of interaction between the basin and the open ocean are studied: (i) the meanders and eddies that travel westward with the Caribbean Current, and (ii) a subsurface eastward current that flows along the South America north coast. The ventilation of the basin through its channels is analyzed by studying the annual variations of the thermocline depth in the basin channels. In addition to the improved knowledge of the Cariaco basin circulation, which can help to better understand the climate of the past through paleoceanographic studies, this work is also an example of the feasibility of one of the objectives of GODAE: downscaling from a large-scale model to a regional model. In particular, the nesting ratio of 5 used in this work (from 9 km down to 1.82 km) demonstrates that a high-resolution model can be successfully nested in HYCOM. [less ▲]

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See detailDownscaling transient climate change with a stochastic weather generator for the Geer catchment, Belgium
Blenkinsop, Steve; Harpham, C.; Burton, A. et al

in Climate Research (2013)

The coarse resolution of climate models creates the need for future scenarios which are downscaled to an appropriate spatial scale. Considerable effort has been devoted to the development of downscaling ... [more ▼]

The coarse resolution of climate models creates the need for future scenarios which are downscaled to an appropriate spatial scale. Considerable effort has been devoted to the development of downscaling methods but a number of important issues remain in the development of robust, usable climate scenarios. These include the incorporation of various sources of uncertainty into future scenarios and the production of scenarios at timescales relevant to planners. This paper describes a new procedure which addresses these issues by producing a multi-model ensemble of transient climate change scenarios. This method couples an existing stochastic rainfall model to a new, transient implementation of a weather generator, using changes projected by an ensemble of regional climate model (RCM) experiments. The methodology is demonstrated by the generation of transient scenarios of daily rainfall, temperature and potential evapotranspiration (PET) for the Geer catchment in Belgium for the period 2010 to 2085. The utility of these scenarios is demonstrated by assessing the changes projected by the simulated time series of several temperature indices. The Geer is projected to experience a decrease in the occurrence of frost days with a corresponding shortening of the frost season and lengthening of the growing season. By examining a large ensemble of transient scenarios the range of uncertainty in these projections is assessed, but further, it is suggested that additional information on the projected timing of specified threshold events or system responses may be provided which could aid planners in assessing the likely timescales of required interventions and adaptation responses. [less ▲]

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See detailDownstream proceeding.
Thonart, Philippe ULg

Poster (1987, June)

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See detailDoxa
Provenzano, François ULg

in Glinoer, Anthony; Saint-Amand, Denis (Eds.) Lexique Socius. Les concepts des approches sociales du littéraire (2014)

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See detailLes doyens de l'immigration - Le troisième âge immigré en Belgique
Perrin, Nathalie ULg

Book published by Academia-Bruylant (2009)

" On a fait appel à des bras et ce sont des êtres humains qui sont venus ", et pour continuer la sentence de l'écrivain suisse Max Frisch qui indiquait que l'immigration était et est, avant tout, une ... [more ▼]

" On a fait appel à des bras et ce sont des êtres humains qui sont venus ", et pour continuer la sentence de l'écrivain suisse Max Frisch qui indiquait que l'immigration était et est, avant tout, une problématique humaine, on pourrait dire que ces êtres humains sont restés et ont vieilli. Dans les années 1970, certains pensaient qu'une fois le pactole amassé et le travail manquant, les immigrés rentreraient chez eux. Ils sont restés. Et puis, on les a oubliés, pour ne parler que de leurs enfants, ces fameuses deuxième, troisième, quatrième générations. Voici l'une des premières recherches menées sur la question en Belgique, résultat d'une étude menée en 2004 en Wallonie et à Bruxelles, revue et enrichie en décembre 2007. L'hypothèse de départ est que les immigrés âgés connaissent les mêmes difficultés et problèmes que les autres personnes âgées, en particulier celles appartenant à un milieu social comparable. Ce qui les en différencie, cependant, c'est l'ignorance dont ils font l'objet de la part des institutions et des autorités publiques. Cette étude propose ainsi une revue de la littérature existante sur le sujet en Belgique, une série de données et d'analyses statistiques, les principales caractéristiques de cette population établie à partir d'entretiens et propose des pistes de réflexion pour une meilleure prise en compte du vieillissement des personnes immigrées de Belgique. [less ▲]

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See detail« Dozon, Jean-Pierre. Une anthropologie en mouvement. L’Afrique miroir du contemporain. Versailles. Éditions Quae, 2008, 272 p.»
Melice, Anne ULg

in Cahiers d'Etudes Africaines (2013), 212(LIII (4)), 951-954

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See detail« Dozon, Jean-Pierre. Une anthropologie en mouvement. L’Afrique miroir du contemporain. Versailles. Éditions Quae, 2008, 272 p.»
Melice, Anne ULg

in Cahiers d'Etudes Africaines (2013), 212(LIII (4)), 951-954

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See detailDPF
Bibliographisches Institut; Münzberg, Franziska ULg

Software (2013)

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See detailDPP-4 inhibitors in the management of type 2 diabetes: A critical review of head-to-head trials.
SCHEEN, André ULg

in Diabètes & Métabolism (2011)

Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes. Direct comparisons with active glucose-lowering comparators in drug-naive patients have demonstrated that ... [more ▼]

Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes. Direct comparisons with active glucose-lowering comparators in drug-naive patients have demonstrated that DPP-4 inhibitors exert slightly less pronounced HbA(1c) reduction than metformin (with the advantage of better gastrointestinal tolerability) and similar glucose-lowering effects as with a thiazolidinedione (TZD; with the advantage of no weight gain). In metformin-treated patients, gliptins were associated with similar HbA(1c) reductions compared with a sulphonylurea (SU; with the advantage of no weight gain, considerably fewer hypoglycaemic episodes and no need for titration) and a TZD (with the advantage of no weight gain and better overall tolerability). DPP-4 inhibitors also exert clinically relevant glucose-lowering effects compared with a placebo in patients treated with SU or TZD (of potential interest when metformin is either not tolerated or contraindicated), and as oral triple therapy with a good tolerability profile when added to a metformin-SU or pioglitazone-SU combination. Several clinical trials also showed a consistent reduction in HbA(1c) when DPP-4 inhibitors were added to basal insulin therapy, with no increased risk of hypoglycaemia. Because of the complex pathophysiology of type 2 diabetes and the complementary actions of glucose-lowering agents, initial combination of a DPP-4 inhibitor with either metformin or a glitazone may be applied in drug-naive patients, resulting in greater efficacy and similar safety compared with either drug as monotherapy. However, DPP-4 inhibitors were less effective than GLP-1 receptor agonists for reducing HbA(1c) and body weight, but offer the advantage of being easier to use (oral instead of injected administration) and lower in cost. Only one head-to-head trial demonstrated the non-inferiority of saxagliptin vs sitagliptin. Clearly, more trials of direct comparisons between different incretin-based therapies are needed. Because of their pharmacokinetic characteristics, pharmacodynamic properties (glucose-dependent glucose-lowering effect) and good overall tolerability profile, DPP-4 inhibitors may have a key role to play in patients with renal impairment and in the elderly. The role of DPP-4 inhibitors in the therapeutic armamentarium of type 2 diabetes is rapidly evolving as their potential strengths and weaknesses become better defined mainly through controlled clinical trials. [less ▲]

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See detailThe Dppa Gene of Bacillus Subtilis Encodes a New D-Aminopeptidase
Cheggour, Abdelatif; Fanuel, Laurence; Duez, Colette ULg et al

in Molecular Microbiology (2000), 38(3), 504-13

Different strains of Bacillus were screened for their ability to hydrolyse D-alanyl-p-nitroanilide. Activity was detected in Bacillus pumilus, Bacillus brevis, Bacillus licheniformis 749I and Bacillus ... [more ▼]

Different strains of Bacillus were screened for their ability to hydrolyse D-alanyl-p-nitroanilide. Activity was detected in Bacillus pumilus, Bacillus brevis, Bacillus licheniformis 749I and Bacillus subtilis 168. The last strain was the best producer and was selected for the production and purification of the enzyme. The determination of the N-terminal sequence identified the enzyme as the product of the dppA gene (previously named dciAA) belonging to the dipeptide ABC transport (dpp) operon expressed early during sporulation. Open reading frames (ORFs) encoding putative related proteins were found in the genomes of a variety of Archaea and both sporulating and non-sporulating bacteria. The enzyme behaves as a D-aminopeptidase and represents the prototype of a new peptidase family. Among the tested substrates, the highest activities were found with D-Ala-D-Ala and D-Ala-Gly-Gly. The active enzyme behaves as an octamer of identical 30 kDa subunits. It exhibits a broad pH optimum, extending between pH 9 and 11. It is reversibly inhibited in the presence of Zn2+ chelators, and the sequence comparisons highlight the conservation of potential Zn-binding residues. As it has been shown by others that null mutations in the dpp operon do not inhibit spore formation, the physiological role of DppA is probably an adaptation to nutrient deficiency. [less ▲]

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