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See detailContribution of epigenetic alteration of BRCA1 and BRCA2 genes in breast carcinomas in Tunisian patients
Ben Gacem, Riadh; Hachana, Mohamed Ridha ULg; Ziadi, Sonia et al

in Cancer Epidemiology, Biomarkers & Prevention : A Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology (2011)

Objective: The aim of this study was to evaluate the contribution of the BRCA1 and BRCA2 promoter methylation in the pathogenesis of sporadic breast cancer in Tunisian patients. Methods: Breast carcinoma ... [more ▼]

Objective: The aim of this study was to evaluate the contribution of the BRCA1 and BRCA2 promoter methylation in the pathogenesis of sporadic breast cancer in Tunisian patients. Methods: Breast carcinoma tissues (n=117) and available paired normal breast tissues (n=65) from Tunisian women who had no family history were investigated for the methylation status of BRCA1 and BRCA2 promoters using methylation-specific PCR. Breast specimens from women without carcinoma (16 fibroadenomas and 5 mastopathies) were used as control. Results: Hypermethylation of BRCA1 and BRCA2 promoters was detected respectively in 60.7% and 69.2% of the carcinoma tissues, and in only 7.7% and 4.6% of the paired normal breast tissues. None of the fibroadenomas and mastopathies showed hypermethylation. Correlations were found between BRCA1 and BRCA2 hypermethylation and decrease in their mRNA expression (p=0.02 and p=0.009, respectively). Moreover, BRCA1 methylation correlates with patients age (p=0.01) and triple negative (ER-, PR-, HER2-) tumors (p=0.01). Patients with methylated BRCA1 and/or BRCA2 had a significant prolonged survivals compared to those with unmethylated tumors (p=0.002). Conclusion: Our results suggest an important role of BRCA1 and BRCA2 promoter methylation in breast cancer development in the Tunisian population. [less ▲]

Detailed reference viewed: 42 (8 ULg)
See detailThe contribution of ERS1 SAR data in neotectonics
Cornet, Yves ULg; Ozer, Pierre ULg

in Guyenne, T. D. (Ed.) Proceedings of the Second ERS Applications Workshop, London, UK, 6-8 December 1995 (1996)

Detailed reference viewed: 13 (3 ULg)
See detailThe contribution of ethnoarchaeological macro- and microscopic wear traces to the understanding of archaeological hide-working processes
Beyries, Sylvie; Rots, Veerle ULg

in Longo, Laura; Della Riva, Martina (Eds.) Proceedings of the Congress "Prehistoric Technology: 40 years later. Functional Studies and the Russian Legacy" (2008)

Detailed reference viewed: 23 (2 ULg)
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See detailThe contribution of familiarity to within- and between-domain associative recognition memory: Use of a modified remember/know procedure
Bastin, Christine ULg; Van der Linden, Martial ULg; Schnakers, Caroline ULg et al

in European Journal of Cognitive Psychology (2010), 22(6), 922-943

The purpose of the present study was to determine the extent to which familiarity can support associative recognition memory as a function of whether the associations are within- or between-domain ... [more ▼]

The purpose of the present study was to determine the extent to which familiarity can support associative recognition memory as a function of whether the associations are within- or between-domain. Standard recognition and familiarity only performance were compared in different participants, using a new adaptation of the remember/know procedure. The results indicated that within-domain (face face) associative recognition was mainly supported by familiarity. In contrast, familiarity provided relatively poor support to between-domain (face name) associative recognition for which optimal performance required a major recollection contribution. These findings suggest that familiarity can support associative recognition memory, particularly for within-domain associations, and contrast with the widely held view that associative recognition depends largely on recollection. [less ▲]

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See detailContribution of GC×GC TOFMS to tobacco analysis
Brokl, Michal ULg; Bishop, Louise; Wright, Christopher et al

Scientific conference (2011, September 21)

Detailed reference viewed: 4 (2 ULg)
See detailContribution of GC×GC-TOFMS to tobacco analysis
Brokl, Michal ULg; Bishop; Liu et al

Conference (2012, January)

Detailed reference viewed: 5 (0 ULg)
See detailContribution of glycoproteomics in the search for accessible biomarkers in human lymphoma
Kischel, Philippe; Greffe, Yannick; Waltregny, David ULg et al

Scientific conference (2008)

Detailed reference viewed: 10 (1 ULg)
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See detailContribution of high mass resolution and accuracy of FTMS to molecular imaging
Debois, Delphine ULg; Calligaris, David ULg; Cimino, Jonathan ULg et al

Conference (2012, April 04)

Since its first implementation in 1997, MALDI Mass Spectrometry Imaging (MALDI MSI) has become an important tool in the proteomic arsenal, especially for biomarker hunting. First dedicated to high ... [more ▼]

Since its first implementation in 1997, MALDI Mass Spectrometry Imaging (MALDI MSI) has become an important tool in the proteomic arsenal, especially for biomarker hunting. First dedicated to high molecular weight, MALDI MSI is more and more used to map the distribution of small molecules too (lipids, drugs and metabolites,…). Last developments tend to improve the sample treatments to obtain the best spatial resolution as possible. From this perspective, great efforts have been made on the MALDI matrix deposition methods. Now, one of the remaining challenges for MALDI-MSI users consists of identification of detected molecules. For high molecular weight, methods inspired by classical proteomics techniques, are regularly used. Bottom-Up (PMF obtained after in situ trypsin digestion) and Top-Down (in situ In-Source Decay) approaches have been used directly from a tissue slice, leading to the identification of some of the most abundant proteins present at the surface of the tissue. When small molecules are analyzed, the identification is more straightforward. Indeed, tandem mass spectrometry can easily be used, leading to the fragmentation of the detected compounds which allows their unambiguous identification. This identification is even more reliable when high resolution exact mass measurements can be performed. In this talk, I will present how in our lab, we profit of the exceptional features of FT-ICR mass spectrometry for imaging and especially for identification purposes. The first example will deal with the benefit of high mass accuracy and high mass resolution for ISD-based protein identification. The mass accuracy and high mass resolution coupled with the use of a “cleaning” software allow unequivocal assignment of ISD fragments of proteins, in the low mass range (m/z between 300 and 900), whether from pure solutions or from tissue slices. The next examples will deal with the imaging of small molecules. The identification of drugs and their metabolites is facilitated with high mass accuracy. In our lab, we work on the localization of methadone and its first metabolite, EDDP in necrophagous fly larvae. In the mass range of these compounds (278-310 m/z), many matrix ion peaks are detected and the unique features of FT-ICR allows for unambiguous identification thanks to exact mass measurements. We also use MALDI Imaging to map the messenger molecules between plant roots and beneficial bacteria. The comparison of spectra recorded with a TOF/TOF instrument and with a FT-ICR demonstrates that high resolution allows for detecting molecules which could have been missed otherwise. It also allows to distinguish unknown compounds from alkali adducts of known molecules. [less ▲]

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See detailContribution of Host MMP-2 and MMP-9 to Promote Tumor Vascularization and Invasion of Malignant Keratinocytes
Masson, Véronique ULg; de la Ballina, L. R.; Munaut, Carine ULg et al

in FASEB Journal (2005), 19(2), 234-6

The matrix metalloproteinases (MMPs) play a key role in normal and pathological angiogenesis by mediating extracellular matrix degradation and/or controlling the biological activity of growth factors ... [more ▼]

The matrix metalloproteinases (MMPs) play a key role in normal and pathological angiogenesis by mediating extracellular matrix degradation and/or controlling the biological activity of growth factors, chemokines, and/or cytokines. Specific functions of individual MMPs as anti- or proangiogenic mediators remain to be elucidated. In the present study, we assessed the impact of single or combined MMP deficiencies in in vivo and in vitro models of angiogenesis (malignant keratinocyte transplantation and the aortic ring assay, respectively). MMP-9 was predominantly expressed by neutrophils in tumor transplants, whereas MMP-2 and MMP-3 were stromal. Neither the single deficiency of MMP-2, MMP-3, or MMP-9, nor the combined absence of MMP-9 and MMP-3 did impair tumor invasion and vascularization in vivo. However, there was a striking cooperative effect in double MMP-2:MMP-9-deficient mice as demonstrated by the absence of tumor vascularization and invasion. In contrast, the combined lack of MMP-2 and MMP-9 did not impair the in vitro capillary outgrowth from aortic rings. These results point to the importance of a cross talk between several host cells for the in vivo tumor promoting and angiogenic effects of MMP-2 and MMP-9. Our data demonstrate for the first time in an experimental model that MMP-2 and MMP-9 cooperate in promoting the in vivo invasive and angiogenic phenotype of malignant keratinocytes. [less ▲]

Detailed reference viewed: 48 (6 ULg)
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See detailThe contribution of large genomic deletions at the CDKN2A locus to the burden of familial melanoma.
Lesueur, F.; de Lichy, M.; Barrois, M. et al

in British Journal of Cancer (2008), 99(2), 364-70

Mutations in two genes encoding cell cycle regulatory proteins have been shown to cause familial cutaneous malignant melanoma (CMM). About 20% of melanoma-prone families bear a point mutation in the ... [more ▼]

Mutations in two genes encoding cell cycle regulatory proteins have been shown to cause familial cutaneous malignant melanoma (CMM). About 20% of melanoma-prone families bear a point mutation in the CDKN2A locus at 9p21, which encodes two unrelated proteins, p16(INK4a) and p14(ARF). Rare mutations in CDK4 have also been linked to the disease. Although the CDKN2A gene has been shown to be the major melanoma predisposing gene, there remains a significant proportion of melanoma kindreds linked to 9p21 in which germline mutations of CDKN2A have not been identified through direct exon sequencing. The purpose of this study was to assess the contribution of large rearrangements in CDKN2A to the disease in melanoma-prone families using multiplex ligation-dependent probe amplification. We examined 214 patients from independent pedigrees with at least two CMM cases. All had been tested for CDKN2A and CDK4 point mutation, and 47 were found positive. Among the remaining 167 negative patients, one carried a novel genomic deletion of CDKN2A exon 2. Overall, genomic deletions represented 2.1% of total mutations in this series (1 of 48), confirming that they explain a very small proportion of CMM susceptibility. In addition, we excluded a new gene on 9p21, KLHL9, as being a major CMM gene. [less ▲]

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See detailContribution of Lexico-Semantic Processes to Verbal Short-Term Memory Tasks: A Pet Activation Study
Collette, Fabienne ULg; Majerus, Steve ULg; Van der Linden, Martial ULg et al

in Memory (2001), 9(4-6), 249-259

Recent studies have demonstrated the intervention of long-term memory processes in verbal STM tasks and several cognitive models have been proposed to explain these effects. A PET study was performed in ... [more ▼]

Recent studies have demonstrated the intervention of long-term memory processes in verbal STM tasks and several cognitive models have been proposed to explain these effects. A PET study was performed in order to determine whether supplementary cerebral areas are involved when subjects have to execute short-term memory tasks for items having representations in long-term memory (in comparison to items without such representations: words vs non-words). Results indicate that verbal STM for words specifically involves the left middle temporal gyrus (BA 21) and temporo-parietal junction (BA 39). These areas can be associated with lexical and semantic processes. These results are in agreement with cognitive models that postulate the simultaneous influence of lexical and semantic long-term representations on verbal STM processes and/or a lexico-semantic buffer. [less ▲]

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See detailThe contribution of macroalgae to the assessment of the ecological quality of the rivers in Wallonia based on macrophytes indicator values in the British and French approaches
Sossey Alaoui, Khadija ULg; Galoux, Daniel; Rosillon, Francis ULg

Poster (2009, November 26)

In accordance with the water Framework Directive (WFD, European Parliament & The Council of the European Union, 2000) defining the overall ecological status of rivers, many hundred sites were analysed in ... [more ▼]

In accordance with the water Framework Directive (WFD, European Parliament & The Council of the European Union, 2000) defining the overall ecological status of rivers, many hundred sites were analysed in the Walloon network. Within each sample, macroalgae data were gathered at species/or at genus level and the main water quality parameters were collected several times per year from 2005 to 2009. <br />Seventeen species and genera cited in the French and English lists of macrophyte methods used to assess the ecological quality of rivers were considered. Within these sites, the ratio of the macroalgae among the contributory species was examined and the impact of these on the final scores of the River Macrophytes Nutrient index (United Kingdom, Wilby et al.,2006) and the biological macrophytic index in rivers (France, Haury et al., 2006) was analysed.At the same time, a ranking of these macroalgae along a trophy gradient has been established thanks to a principal component analysis of the physico-chemical parameters and a weighting of the species presence in a given waterbody by its abundance.The relationships between macroalgae scores and those found in France and in United Kingdom were studied using the Spearman rank correlation coefficient. <br />Literature: <br />European Parliament & The Council of the European Union, 2000. Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy. Official Journal of the European Communities 327: 1-72.Haury, J., M.-C. Peltre, M. Trémolières, J. Barbe, G. Thiébaut, I. Bernez, H. Daniel, P. Chatenet, G. Haan-Archipof, S. Muller, A. Dutartre, C. Laplace-Treyture, A. Cazaubon & E. Lambert-Servien, 2006. A new method to assess water trophy and organic pollution – the Macrophyte Biological Index for Rivers (IBMR): its application to different types of river and pollution. Hydrobiologia 570: 153-158. Willby, N., J. Pitt & G. Phillips, 2006. Summary of approach used in LEAFPACS for defining ecological quality of rivers and lakes using macrophyte composition. Draft Report January 2006. [less ▲]

Detailed reference viewed: 26 (8 ULg)
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See detailContribution of MT1-MMP and of Human Laminin-5 Gamma2 Chain Degradation to Mammary Epithelial Cell Migration
Gilles, Christine ULg; Polette, M.; Coraux, C. et al

in Journal of Cell Science (2001), 114(Pt 16), 2967-76

Membrane-type matrix metalloproteinase 1 (MT1-MMP) is a membrane-anchored matrix metalloproteinase (MMP) that is frequently associated with processes involving tissue remodelling and cell migration. We ... [more ▼]

Membrane-type matrix metalloproteinase 1 (MT1-MMP) is a membrane-anchored matrix metalloproteinase (MMP) that is frequently associated with processes involving tissue remodelling and cell migration. We have examined MT1-MMP expression and subcellular distribution as a function of MCF10A mammary epithelial cell migration using an in vitro outgrowth migration assay. Stronger expression of MT1-MMP was observed at the mRNA and at the protein level in cells at the periphery of the outgrowth. As shown by videomicroscopy, these cells were involved in an orientated cell migration, in contrast to stationary cells distant from the periphery. Furthermore, MT1-MMP was mainly distributed in lamellipodia of migratory cells, as well as at their basal surface in contact with the substrate. Laminin-5 (Ln-5), a recently described substrate for MT1-MMP, was deposited preferentially in the matrix by migratory cells. Fragments of the gamma2 subunit of Ln-5 were also identified in migratory cultures of MCF10A cells, attesting to its proteolytic degradation. These fragments corresponded in size to those we observed after incubation of purified human Ln-5 with the recombinant catalytic domain of human MT1-MMP. We also show that anti-Ln5 blocking antibodies, MMP inhibitors (BB94 and TIMP-2) and MT1-MMP antisense oligonucleotides significantly decreased MCF10A cell migration. Taken together, these observations demonstrate that MT1-MMP is spatially and temporally regulated during MCF10A cell migration, and suggest that MT1-MMP-mediated pericellular proteolysis of Ln-5 gamma2 chain could contribute to this process. [less ▲]

Detailed reference viewed: 48 (4 ULg)
See detailThe contribution of Multidimensional IRT for modeling applicants performance on a SJT.
Lothe, Benoit ULg; Monseur, Christian ULg; Hansez, Isabelle ULg

Poster (2013, May)

Situational judgment tests (SJTs) are testing methods often used in Personnel Selection to appraise different constructs (Whetzel & McDaniel, 2009). In the framework of an overall career progression ... [more ▼]

Situational judgment tests (SJTs) are testing methods often used in Personnel Selection to appraise different constructs (Whetzel & McDaniel, 2009). In the framework of an overall career progression program in a Public Administration, SJTs were developed to assess several competencies relevant to both task (e.g. planning, managing, etc.) and contextual performance (e.g. helping behaviour, organizational loyalty, etc.). Each competency is a combination of KSAOs needed to perform efficiently in a specific context (Campion & al., 2012; Le Boterf 2008). Given the lack of internal consistency of SJT and the dichotomous nature of the data, we decide to use Multidimensional Item Response Theory (MIRT) model to examine the issue of construct validity. Based on Hartig & Höhler (2009), we use MIRT compensatory model to estimate the latent covariance structures of the SJT. Different model are tested and compared depending on the number of dimension involved, the nature of the items and latent variables relation (between or within-item multidimensionality) and the number of model parameter (one or two parameter model). The results and findings lead us to discuss some implications (gaining accuracy, modeling performance in complex task, etc.) and limitations (dealing with complex loading structure, etc.) of using IRT, over and above classical test theory, in the specific case of SJTs applicants performance. The originality of this communication also lies in the way we addressed SJTs reliability and construct validity issues with a measurement based model that differs from the one usually used in the field. [less ▲]

Detailed reference viewed: 20 (0 ULg)
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See detailContribution of Mutant Analysis to the Understanding of Enzyme Catalysis: The Case of Class a Beta-Lactamases
Matagne, André ULg; Frère, Jean-Marie ULg

in Biochimica et Biophysica Acta (1995), 1246(2), 109-27

Class A beta-lactamases represent a family of well studied enzymes. They are responsible for many antibiotic resistance phenomena and thus for numerous failures in clinical chemotherapy. Despite the facts ... [more ▼]

Class A beta-lactamases represent a family of well studied enzymes. They are responsible for many antibiotic resistance phenomena and thus for numerous failures in clinical chemotherapy. Despite the facts that five structures are known at high resolution and that detailed analyses of enzymes modified by site-directed mutagenesis have been performed, their exact catalytic mechanism remains controversial. This review attempts to summarize and to discuss the many available data. [less ▲]

Detailed reference viewed: 59 (3 ULg)
See detailContribution of MX dynamin, oligoadenylate synthetase, and protein kinase R to anti-paramyxovirus activity of type-1 interferons in vitro
Leroy, M.; Baise, Etienne ULg; Pire, G. et al

in American Journal of Veterinary Research (2007), 68

OBJECTIVE: To determine the contribution of MX dynamin, oligoadenylate synthetase (OAS), and double-stranded RNA-dependent protein kinase R (PKR) to the antiviral effects of type 1 interferons (IFNs ... [more ▼]

OBJECTIVE: To determine the contribution of MX dynamin, oligoadenylate synthetase (OAS), and double-stranded RNA-dependent protein kinase R (PKR) to the antiviral effects of type 1 interferons (IFNs) against bovine parainfluenza-3 virus (PI-3V) infection of Vero cells. SAMPLE POPULATION: Vero cell cultures. PROCEDURES: PI-3V yield was first compared between control and transfected type 1 IFNs-incompetent Vero cells expressing recombinant OAS or MX proteins. Afterwards, phosphorylation of eukaryotic initiation factor 2 alpha (eIF2alpha) was used to scale the degree of PKR activation upon infection of Vero cells by PI-3V. RESULTS: Overexpression of OAS did not result in significantly decreased viral replication. Phosphorylated eIF2alpha forms, the hallmark of PKR activation, were not increased in IFNalpha-primed infected Vero cells. Although human MXA contributed to partial blockade of replication of bovine PI-3V, the antiviral effect was not as strong as that of IFNalpha. CONCLUSIONS AND CLINICAL RELEVANCE: The powerful anti-Paramyxovirus activity of type 1 IFNs is mediated by noncanonic pathways. [less ▲]

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See detailContribution of nanoclays to the barrier properties of a model proton exchange membrane for fuel cell application
Thomassin, Jean-Michel ULg; Pagnoulle, Christophe; Caldarella, Giuseppe ULg et al

in Journal of Membrane Science (2006), 270(1-2), 50-56

Direct methanol fuel cells (DMFCs) that use a proton exchange membrane (PEM) as electrolyte, is a promising alternative source of energy for the future. However, methanol crossover from the anodic side to ... [more ▼]

Direct methanol fuel cells (DMFCs) that use a proton exchange membrane (PEM) as electrolyte, is a promising alternative source of energy for the future. However, methanol crossover from the anodic side to the cathodic one is a major problem in DMFC. Proper dispersion of layered silicates within the fuel cell membrane has been proposed as a strategy for improving the barrier properties of the membrane. The validity of this approach has been tested in case of a model membrane consisting of phosphotungstic acid doped poly(vinyl alcohol). A solvent casting technique has been used, which allows the nanofiller to be delaminated by an ultrasonic pre-treatment, as confirmed by TEM and XRD analysis. The layered silicates have a favourable impact on the methanol permeability, whose the decrease overcompensates some loss in ionic conductivity. [less ▲]

Detailed reference viewed: 25 (0 ULg)