References of "Gillet, Marie-Claire"
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See detailMG-63 Osteoblast Culture on Biodegradable Textiles for Bone Tissue Regeneration
Moniotte, Nicolas; Borget, Pascal; Pirotte, Fabrice et al

Poster (2007)

The primary aim of bone scaffold is to restore, maintain and improve the structure and properties of damaged bones. The scaffold acts as a 3-D template for guided tissue-engineering and provides an ... [more ▼]

The primary aim of bone scaffold is to restore, maintain and improve the structure and properties of damaged bones. The scaffold acts as a 3-D template for guided tissue-engineering and provides an excellent transition from in vitro to in vivo systems, avoiding auto- or allo-grafting treatments, both associated with serious limitations. The pore size of the scaffold must be large enough to allow cell migration and proliferation through the structure, but small enough to provide sufficient specific area for cell attachment. In this work, degradable poly(lactic acid) (PLA) yarns were knitted into complexes superstructures and evaluated as 3-D scaffold to promote cell bone reconstruction. PLA fabrics were knitted from multi-filaments in a double layer interlock structure to produce a weft knit. The fabrics are made of two porosities, one defined by the open space inside a loop (~1mm) and the second by the distance between the filaments (1-10 µm), with high control and reproducibility inherent to the manufacturing process. Human MG-63 osteoblast-like cells were seeded on PLA textiles and cell viability and proliferation were evaluated using MTS (tetrazolium salt) assays, DNA quantitative analysis (hoechst), fluorescence staining (acridine orange) and scanning electron microscopy. Alkaline Phosphatase activity in cell lysates was also investigated. After 3 days of culture, MG-63 fully expressed their fibroblastic phenotype. Although the number of cells was high, mitochondrial activity was shown to be reduced when cells are on the PLA fibres (compared to culture on a glass slide). This may be due the release of lactic acid by slow hydrolysis of PLA ester-bonds. Only a small population of cells was dead. Furthermore, it could be due to cells in a less active phase, such as cells entering the G0 phase, or in a maturing phase. From 6 to 12 days, the number of cell inside the PLA fabrics increased and typical fibroblastic morphology was maintained. Cells were mainly observed in the spaces between fibres. After 24 days of culture, MG-63 colonization is covering all the PLA knit. Small granular structures are present on the cell surface and low ALP concentration is detected, indicating the beginning of the differentiation process, rather than a toxic effect of PLA hydrolysis. This work shows that knitted PLA fabrics, seeded with autogeneous osteoblast cells can potentially be used as tissue-engineered implants for the treatment of bone defects. [less ▲]

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See detailMG-63 osteoblasts culture on poly-(lactic acid) degradable textiles for bone tissue regeneration
Moniotte, Nicolas; Pirotte, Fabrice; Borget, Pascal et al

Article for general public (2007)

This work shows that knitted PLA fabrics, seeded with human MG-63 osteoblasts can potentially be used as tissue engineered systems for in vitro to in vivo transition, for the treatment of bone defect

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See detailMercury in the blood of free ranging pinnipeds: levels, sources of variation, toxicocinetic and potential impact using an in vitro model
Das, Krishna ULg; Gillet, Marie-Claire ULg; Habran, Sarah ULg et al

Conference (2007)

Despite 30 years of international regulations, Hg levels in marine mammals have not decreased. Various environmental models even suggest a rise of mercury in the biota during the next decades, linked to ... [more ▼]

Despite 30 years of international regulations, Hg levels in marine mammals have not decreased. Various environmental models even suggest a rise of mercury in the biota during the next decades, linked to climate change. The objective of this study is (1) to assess Hg levels in blood samples of free-ranging pinnipeds, (2) to understand level variation during different periods of life (gestation, lactation, fasting) and potential impact on lymphocytes using a preliminary in vitro model (peripheral blood mononuclear cells, PBMC). Blood samples were collected from harbour seals (Phoca vitulina n= 22) from the North Sea and from elephant seals from the Californian coast (Mirounga angustirostris 12 females and 12 pups). Harbour seal PBMC were isolated, set in medium culture and contaminated with methyl-Hg (1 µM). Biological tests and proteomic assay were realized on control and contaminated PBMC. Hg levels were from the same order of magnitude for the two species despite two different lifestyles and habitats: from 40 to 590 ng.g-1 fw in harbour seal and from 63 to 919 ng.g-1 fw in elephant seal. Hg concentrations in the blood depend upon several factors such as body weight, fasting and lactation duration for mothers and pups. After 21 days of lactation, female elephant seals doubled their blood Hg levels (from 308 to 593 ng.g-1fw) while a decrease is observed for pups. This increase is linked to mobilization from blubber and muscle during fasting associated to lactation. Cell model revealed an in vitro effect of Hg even at low concentration (1µM). Number of PBMC, viability, metabolic activity, DNA and RNA synthesis were reduced in vitro suggesting deleterious effects of Hg in concentrations encountered in free-ranging pinnipeds. Knowing that Hg methylation in the ocean is linked to temperature, one can wonder on Hg levels (and effects) in pinnipeds during the next decades. [less ▲]

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See detailStudy of the effect of exposition of MCF-7/bos cells to 17-ß-estradiol by 2D DIGE
Collodoro, Mike; Dobson, Rowan ULg; Bertrand, Virginie ULg et al

Poster (2006, October)

The aim of this work is to identify biomarkers following exposition to 17ß-estradiol in MCF7/bos (hormonal dependent epithelial mammary cancer) cells. The application is to optimise screening tests that ... [more ▼]

The aim of this work is to identify biomarkers following exposition to 17ß-estradiol in MCF7/bos (hormonal dependent epithelial mammary cancer) cells. The application is to optimise screening tests that will enable the detection (and eventual quantification but not identification) of numerous compounds having an estrogenic activity in a single rapid test. [less ▲]

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See detailNew Cold Plasma and DLC Surface Treatments for Medical Co-Cr-Mo and Ti-6Al-4V Prostheses
Matarazzo, Lucas; Gillet, Marie-Claire ULg; Forest, B et al

Poster (2006, September 27)

Recent studies indicate that the most important factor limiting the longevity of hip prostheses is the production of wear particles from the prosthetic components. We have studied the effect of two ... [more ▼]

Recent studies indicate that the most important factor limiting the longevity of hip prostheses is the production of wear particles from the prosthetic components. We have studied the effect of two surface treatment techniques on the Ti-6Al-4V alloy: ionic nitruration (cold plasma) and Diamond-like Coating (DLC). These two techniques create a layer of 7-8 μm in depth on the surface of the alloy, modifying its structure and hardening it considerably. Biocompatibility was analyzed using cellular culture to compare viability, proliferation (DNA quantification) and differentiation (ALP assay) of human osteoblast-like cells (MG 63) as well as cellular adhesion of human fibroblasts (WI 38) or osteoblasts, under SEM. [less ▲]

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See detailAntiprotozoal and cytotoxic triterpenoid saponins from the roots of Cephalaria gigantea
Tabatadze, Nino; Elias, Riad; Delmas, F. et al

Poster (2006, July)

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See detailN1,N2,N3-trisisopentenyl guanidine and N1,N2-diisopentenyl guanidine, two cytotoxic alkaloids from Alchornea cordifolia (Schumach.& Thonn.) Mull. Arg. (Euphorbiaceae) root barks.
Mavar-Manga, H.; Chapon, David; Hoet, Sara et al

in Natural Product Communications [=NPC] (2006), 1(12), 1097-1100

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See detailInduction of Apoptosis in Human Promyelocytic Leukemia Cells by a Natural Trachylobane Diterpene
Block, Sébastien; Gerkens, Pascal; Peulen, Olivier ULg et al

in Anticancer Research (2005), 25(1A), 363-368

Background: Trachylobane diterpenes are secondary metabolites quite rare in nature and their bioactivities are poorly known. Recently we have described the cytotoxic activity of ent- trachyloban-3‚-ol ... [more ▼]

Background: Trachylobane diterpenes are secondary metabolites quite rare in nature and their bioactivities are poorly known. Recently we have described the cytotoxic activity of ent- trachyloban-3‚-ol isolated from the leaves of Croton zambesicus, a plant used in African folk medicine. Materials and Methods: Cell viability on several cell lines, cell morphology, DNA laddering, annexin V and caspase-3 activation experiments were undertaken in order to analyse the cytotoxicty of trachylobane diterpene and to determine if this compound is able to induce apoptosis. Results: ent-trachyloban-3‚-ol exerts a dose-dependent cytotoxic effect and which varies between cell lines. Induction of apoptosis in HL-60 cells could be detected at a concentration of 50 ÌM after 24-h treatment. Conclusion: We show here, for the first time, that a trachylobane diterpene is able to induce apoptosis in human promyelocytic leukemia cells via caspase-3 activation in a concentration-dependent manner. [less ▲]

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See detailIdentification of Potential Biomarkers of Human Peripheral Blood Mononuclear Cell intoxication by dioxins
Brenez, Cécile; Cellier, Nicolas; Gerkens, Pascal et al

in Organohalogen Compounds (2005), 67

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See detailDetection of biomarkers of pathogenic bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
Ruelle, Virginie; El Moualij, B.; Zorzi, Willy ULg et al

in Lichtfouse, Eric; Schwarzbauer, Jan; Robert, Didier (Eds.) Environmental Chemistry : Green Chemistry and Pollutants in Ecosystems (2005)

In recent years, various mass spectrometry procedures has been developed for identifying bacteria. The accuracy and speed with which data can be obtained by Matrix-assisted laser Desorption/Ionization ... [more ▼]

In recent years, various mass spectrometry procedures has been developed for identifying bacteria. The accuracy and speed with which data can be obtained by Matrix-assisted laser Desorption/Ionization Time-of-flight Mass Spectrometry (MALDI-TOF-MS) make this an advantageous technique for environmental monitoring. However, minor variations in the sample preparation can influence the mass spectra significantly. In the present study, we have introduced a procedure to prepare bacteria by microextraction and we have optimized experimental parameters for rapid identification by MALDI-TOF-MS of whole bacterial cells isolated from environmental samples such as wastewater and soil. [less ▲]

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See detailA strategy to identify specific biomarkers related to the effects of a PCDD/F mixture on the immune system of marine mammals
Brenez, C.; Gerkens, P.; Mazzucchelli, Gabriel ULg et al

in Talanta (2004), 63(5), 1225-1230

The cell lines chosen have demonstrated a positive response in terms of cell proliferation and associated modifications in proteins content, evaluated through DNA and proteins synthesis, at ... [more ▼]

The cell lines chosen have demonstrated a positive response in terms of cell proliferation and associated modifications in proteins content, evaluated through DNA and proteins synthesis, at environmentally relevant dose of dioxins, brought by a typical environmental PCDD/F mixture. The response is time and species dependent. After completion of the identification of proteins affected by the intoxication, we will identify a set of specific proteins whose expression is correlated to the dioxin dose and submit the cell culture to the treatment with a single chemical as well as with mixtures. We hope that this will allow us to construct and validate a set of protein biomarkers of exposure to pollutants that will show a predictive aspect for unknown chemicals. The quantitative analysis of the set of biomarkers can then be a more specific bioassay and an alternative to physico-chemical or other already established bioanalytical methods for screening purposes. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailDiterpenes from the leaves of Croton Zambesicus
Block, Sébastien; Baccelli, Chiara; Tinant, Bernard et al

in Phytochemistry (2004), 65

Two new trachylobane- and one isopimarane-type diterpenoids: ent-18-hydroxy-trachyloban-3-one; ent-trachyloban-3-one; isopimara-7,15-dien-3b-ol, were isolated from the leaves of Croton zambesicus ... [more ▼]

Two new trachylobane- and one isopimarane-type diterpenoids: ent-18-hydroxy-trachyloban-3-one; ent-trachyloban-3-one; isopimara-7,15-dien-3b-ol, were isolated from the leaves of Croton zambesicus, together with trans-phytol, b-sitosterol, a-amyrin and stigmasterol. The structures were determined by extensive NMR techniques and X-ray analysis. The cytotoxicity of these compounds has been evaluated on cancer and non-cancer cell-lines. [less ▲]

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See detailIdentification of specific biomarkers related to the effects of pollutants on the immune system of marine mammals
Brenez, Cécile; Gerkens, Pascal; Jauniaux, Thierry ULg et al

Poster (2004)

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See detailIdentification of specific biomarkers related to the effects of pollutants on the immune system of marine mammals
Brenez, Cécile; Gerkens, Pascal; Jauniaux, Thierry ULg et al

Poster (2003, December)

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See detailApoptosis induction in human cancer cells by sungucine from Strychnos icaja root
Frederich, Michel ULg; Bentires-Ali, M.; Tits, Monique ULg et al

in Naunyn-Schmiedeberg's Archives of Pharmacology (2003), 367(3), 260-265

Sungucine (SG) and isosungucine (ISG) are bisindole alkaloids characterized by a 5'-23 link between the two parts of the compounds, which are till now specific to Strychnos icaja. In this work, SG and ISG ... [more ▼]

Sungucine (SG) and isosungucine (ISG) are bisindole alkaloids characterized by a 5'-23 link between the two parts of the compounds, which are till now specific to Strychnos icaja. In this work, SG and ISG were submitted to the NCI's in vitro 60 human tumor cell line screen, where SG showed interesting selectivity (6X) against the tested leukemia cell lines. In HL60-treated cells, apoptosis was demonstrated by observation of apoptotic bodies formation, and phosphatidylserine exposition at cell surface. In HeLa-treated cells, the analysis of cellular cycle by flow cytometry showed G1 accumulation and a small sub-G1 peak that could be related to DNA fragmentation characteristic of apoptosis. The eventual role of p53 was analyzed using wild-type HCT-116 colon cancer cells. Nevertheless, p53 and Bax expression were not modified in SG-treated cells. The cleavage of PARP by caspase-3 protease proved that apoptosis was also induced in this line. These results demonstrate that SG induces apoptosis, but also necrosis, in human cancer cell lines. [less ▲]

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See detailActivités cytotoxiques et apoptotiques de gigantéosides D et E isolés de Cephalaria gigantea
Gerkens, Pascal; Frederich, Michel ULg; Mshvildadze, Vakhtang et al

Poster (2002, September)

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See detailInduction of apoptosis in HL-60 by a trachylobane diterpene from Croton Zambesicus
Block, Sébastien; Gillet, Marie-Claire ULg; Gerkens, Pascal et al

Poster (2002, September)

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