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See detailIn vitro selection of Phytophthora citrophthora isolates resistant to phosphorous acid and fosetyl-Al.
Ali, M. K.; Lepoivre, Philippe ULg; Semal, J.

in Mededelingen van de Faculteit Landbouwwetenschappen (Rijksuniversiteit te Gent) (1988), 53(2b),

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See detailIn vitro simulation of oxic/suboxic diagenesis in an estuarine fluid mud subjected to redox oscillations
Abril, Gwenael; Commarieu, Marc-Vincent ULg; Etcheber, Henri et al

in Estuarine Coastal And Shelf Science (2010), 88(2), 279-291

Estuarine turbidity maxima (ETMs) are sites of intense mineralisation of land-derived particulate organic matter (OM), which occurs under oxic/suboxic oscillating conditions owing to repetitive ... [more ▼]

Estuarine turbidity maxima (ETMs) are sites of intense mineralisation of land-derived particulate organic matter (OM), which occurs under oxic/suboxic oscillating conditions owing to repetitive sedimentation and resuspension cycles at tidal and neap-spring time scales. To investigate the biogeochemical processes involved in OM mineralisation in ETMs, an experimental set up was developed to simulate in vitro oxic/anoxic oscillations in turbid waters and to follow the short timescale changes in oxygen, carbon, nitrogen, and manganese concentration and speciation. We present here the results of a 27-day experiment (three oxic periods and two anoxic periods) with an estuarine fluid mud from the Gironde estuary. Time courses of chemical species throughout the experiment evidenced the occurrence of four distinct characteristic periods with very different properties. Steady oxic conditions were characterised by oxygen consumption rates between 10 and 40 mu mol L-1 h(-1), dissolved inorganic carbon (DIC) production of 9-12 mu mol L-1 h(-1), very low NE4+ and Mn2+ concentrations, and constant NO3 production rates (0.4 - 0.7 mu mol L-1 h(-1)) due to coupled ammonification and nitrification. The beginning of anoxic periods (24 h following oxic to anoxic switches) showed DIC production rates of 2.5-8.6 mu mol L-1 h(-1) and very fast NO consumption (5.6-6.3 mu mol L-1 h(-1)) and NH4+ production (1.4-1.5 mu mol L-1 h(-1)). The latter rates were positively correlated to NO concentration and were apparently caused by the predominance of denitrification and dissimilatory nitrate reduction to ammonia. Steady anoxic periods were characterised by constant and low NO3- concentrations and DIG and NH4+ productions of less than 1.3 and 0.1 mu mol L-1 h(-1), respectively. Mn2+ and CH4 were produced at constant rates (respectively 0.3 and 0.015 mu mol L-1 h(-1)) throughout the whole anoxic periods and in the presence of nitrate. Finally, reoxidation periods (24-36 h following anoxic to oxic switches) showed rapid NH4+ and Mn2+ decreases to zero (1.6 and 0.8-2 mu mol L-1 h(-1), respectively) and very fast NO production (3 mu mol L-1 h(-1)). This NO3- production, together with marked transient peaks of dissolved organic carbon a few hours after anoxic to oxic switches, suggested that particulate OM mineralisation was enhanced during these transient reoxidation periods. An analysis based on C and N mass balance suggested that redox oscillation on short time scales (day to week) enhanced OM mineralisation relative to both steady oxic and steady anoxic conditions, making ETMs efficient biogeochemical reactors for the mineralisation of refractory terrestrial OM at the land-sea interface. (C) 2010 Elsevier Ltd. All rights reserved. [less ▲]

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See detailIn vitro stability and immunoreactivity of the native and recombinant plant food 2S albumins Ber e 1 and SFA-8
Murtagh, M.; Archer, D.; Dumoulin, Mireille ULg et al

in Clinical & Experimental Allergy : Journal of the British Society for Allergy & Clinical Immunology (2003), 8

Background The ability of an intact protein to reach the circulatory system may be a prerequisite to allergenicity and many allergens, particularly those from plant foods, have been found to be ... [more ▼]

Background The ability of an intact protein to reach the circulatory system may be a prerequisite to allergenicity and many allergens, particularly those from plant foods, have been found to be consistently more resistant to digestion by pepsin than other proteins. Objective This study assessed the pepsinolytic stability of native 2S albumins from Brazil nut and sunflower seed and their recombinant versions produced in Pichia pastoris. The physicochemical stability of native and recombinant Brazil nut 2S albumins and recombinant sunflower seed 2S albumin was also assessed. The immunoreactivity of native Brazil nut 2S albumin and recombinant 2S albumins was compared using serum from patients allergic to Brazil nuts and animals immunized with native 2S albumins. Methods Digestibility was measured in simulated gastric fluid followed by SDS-PAGE. Circular dichroism spectra were used to analyse unfolding, as proteins were denatured by temperature, pH and guanidinium chloride. Immunoreactivity was assessed by immunoblot, RAST and ELISA. Results Brazil nut 2S albumin was significantly more resistant to proteolytic digestion than other Brazil nut proteins. It was also resistant to thermally and chemically induced denaturation. Equally high resistance to proteolytic digestion was observed with sunflower seed 2S albumin. The recombinant albumins mirrored their native counterparts in stability and immunoreactivity. Conclusion The important food allergen Brazil nut 2S albumin is as stable to digestion as is sunflower seed 2S albumin, whose allergenicity has yet to be determined. The 2S albumins and their recombinant counterparts could not be easily denatured by physicochemical treatments. The results suggest that 2S albumin is the only Brazil nut protein to reach the gut immune system intact. The production of properly folded recombinant proteins will facilitate mechanistic studies as well as diagnostic testing and antigen-based therapies. [less ▲]

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See detailIn vitro stimulation of human gingival epithelial cell attachment to dentin by surface conditioning.
Van Heusden, Alain ULg; Goffinet, Gerhard ULg; Zahedi, Sharham et al

in Journal of Periodontology (1999), 70(6), 594-603

BACKGROUND: Chemical root conditioning is widely used to improve the outcome of regenerative periodontal therapies by favoring the attachment of the regenerated periodontal structures. Although the effect ... [more ▼]

BACKGROUND: Chemical root conditioning is widely used to improve the outcome of regenerative periodontal therapies by favoring the attachment of the regenerated periodontal structures. Although the effect of root conditioning on periodontal mesenchymal cells is well documented, very little is known about its potential effect on the re-formation of the junctional epithelium, a crucial event for the protection of the wound. The goal of the present study was to test in vitro the consequences of dentin conditioning with citric acid or minocycline on the attachment kinetics and morphology of human gingival keratinocytes (HGK). METHODS: The attachment kinetics of HGK to samples of powdered human dentin (particle size 44 to 76 microm) were examined by use of 3H-labeled cells. The morphology of attached epithelial cells was then determined by scanning electron microscopy (SEM). RESULTS: When the initial adhesion kinetics of cells on untreated dentin were tested, the percentage of attached HGK proved to be dependent on the number of plated cells and the time of incubation (from 0 to 12 hours). Conditioning the dentin by 3% citric acid or by minocycline-HCl (at 0.01, 0.1, or 2.5%) significantly increased (P <0.005) keratinocyte attachment beyond 6 hours, without notable differences between the 2 substances at any concentration. The attachment kinetics of HGK preincubated for 24 hours by 10 microg/ml minocyline-HCl on untreated dentin was found to be similar to that observed for non-preincubated cells. These results are in agreement with the SEM observations: indeed, the surface conditioning of dentin significantly modified the morphology of attached HGK, whereas the preincubation of these cells with minocyline-HCl did not. CONCLUSIONS: These results suggest that minocycline-HCl does not exert a direct effect on human gingival epithelial cells. In contrast, conditioning the dentin by citric acid or by minocycline stimulates the attachment of HGK, which could lead to a rapid periodontal healing by favoring the re-formation of a junctional epithelium. [less ▲]

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See detailIn vitro studies on the Fc-receptor function of mononuclear phagocytes in rheumatoid arthritis: relation between the Fc-receptor blockade and the concanavalin A-binding capacity of autologous immunoglobulin G
Malaise, Michel ULg; Franchimont, P.; Houssier, C. et al

in Journal of Clinical Immunology (1986), 6(6), 442-456

The Fc-receptor (Fc-R) function of monocytes isolated from 19 control subjects and from 30 patients presenting with a rheumatoid arthritis (RA) was assessed in vitro by a classical rosette assay using IgG ... [more ▼]

The Fc-receptor (Fc-R) function of monocytes isolated from 19 control subjects and from 30 patients presenting with a rheumatoid arthritis (RA) was assessed in vitro by a classical rosette assay using IgG-coated sheep red blood cells. In RA patients, the percentage of monocytes forming rosettes was significantly lower than in controls (34.4 +/- 20.4 versus 67.4 +/- 4.5%; P less than 0.001). The blockade observed was reversed by a prior trypsin treatment of RA monocytes, the percentage of recovery being correlated with the IgG plasma levels. Besides, IgG purified from the serum of four RA patients bound a mean of 7.3, 5.2, 1.6, and 1.6 times more than normal IgG did onto concanavalin A (Con A), peanut agglutinin (PNA), phytohemagglutinin (PHA), and pokeweed mitogen (PWM), respectively. Although similar amounts of 125I-labeled normal and RA IgG were bound to normal monocytes, RA IgG inhibited more efficiently than normal IgG the Fc-R function of normal monocytes, for all concentrations tested (10 to 100 micrograms/100 microliters). A prior treatment of RA IgG by alpha-mannosidase, but not by beta-galactosidase, significantly reduced their inhibitory properties. The incubation of monocytes with D-mannose or mannan reduced their capacity to form rosettes. The percentage of monocytes forming rosettes in the presence of both mannan and normal IgG was significantly lower than that measured in the presence of normal IgG only. On the contrary, the rosetting capacity of monocytes in the presence of both RA IgG and mannan was the same as that calculated in the presence of RA IgG only. The inhibitory effect of RA IgG was not related to their abnormal circular dichroism. Our data suggest that the greater ability of RA IgG to block the Fc-R function of monocytes probably depends on the presence of a greater number of accessible mannosyl residues on the glycosidic side chains located in the Fc domain of the molecules. [less ▲]

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See detailIN VITRO STUDY OF A FIBER NETWORK TAILORED AS 3D-CELL MODEL
Sevrin, Chantal ULg; Lombart, François ULg; Godino, Miguel et al

Poster (2014, June 17)

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See detailIn vitro study of fibroblasts (L929) and osteoblasts (MG-63) within networks differing in fiber density.
Lombart, François ULg; Alexandre, Diane ULg; de Bien, Charlotte ULg et al

Poster (2013, June 18)

Animal cells are typically cultivated in vitro on 2D surfaces therefore in conditions totally differing from their 3D in vivo environments. It is therefore really attractive to generate better in vitro ... [more ▼]

Animal cells are typically cultivated in vitro on 2D surfaces therefore in conditions totally differing from their 3D in vivo environments. It is therefore really attractive to generate better in vitro animal cell models where animal cells can adhere and proliferate within a 3D networks. When facing to a third dimension, the design of the scaffolds tailored to support the organization and communication of cells should favor at least cell adhesion, proliferation and differentiation, while promoting nutrient, gas (O2 / CO2) and waste product diffusion. In order to construct this in vitro model, we have compared the cell reactivity of two model cell lines fibroblaste L 929 and osteoblaste MG-63 within three 3D networks differing in fiber density. This parameter has been altered in order to increase progressively the total surface exposed to the cells, whilst increasing correspondingly the mean pore size and total porosity of the network, whilst keeping the same architecture and surface chemistry of the fibers within the scaffold. [less ▲]

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See detailIn Vitro Study of the Antioxidant Properties of Nimesulide and 4-Oh Nimesulide: Effects on Hrp- and Luminol-Dependent Chemiluminescence Produced by Human Chondrocytes
Zheng, S. X.; Mouithys-Mickalad, Ange ULg; Deby-Dupont, G. P. et al

in Osteoarthritis and Cartilage (2000), 8(6), 419-25

OBJECTIVES: Reactive oxygen species (ROS) are now recognized to play an important role in the pathogenesis of rheumatic diseases and constitute an interesting therapeutic target for drugs. This in vitro ... [more ▼]

OBJECTIVES: Reactive oxygen species (ROS) are now recognized to play an important role in the pathogenesis of rheumatic diseases and constitute an interesting therapeutic target for drugs. This in vitro study was designed to evaluate the antioxidant properties of nimesulide (NIM), a nonsteroidal antiinflammatory drug of the sulfonanilide class, and its main metabolite 4-OH nimesulide (4-OHNIM). METHODS: The scavenging effects of NIM and 4-OH NIM on hydroxyl radical ((.)OH) and superoxide anions (O(minusd)(2)) were investigated by electron spin resonance (ESR), using 5, 5-dimethylpyrroline-N-oxide (DMPO) as the spin trap agent. The quenching properties of these drugs on hypochlorite anion was studied by luminol enhanced chemiluminescence. Finally, the effects of NIM and 4-OHNIM on the reactive oxygen species production by human articular chondrocytes were recorded by HRP and luminol-enhanced chemiluminescence. RESULTS: By this method it has been demonstrated that NIM and 4-OHNIM, at concentrations ranging from 10 to 100 microM, are potent scavengers of(.)OH whereas only 4-OHNIM was capable to scavenge O(minusd)(2). Chemiluminescence generated by HOCl was also significantly and dose-dependently inhibited by both NIM and 4-OHNIM. Nevertheless, at each concentration tested, the inhibitory effect of 4-OHNIM was significantly more marked, even at the highest concentration (100 microM). Furthermore, when chondrocytes were pre-incubated for 48-96 h with NIM or 4-OHNIM, the luminol- and HRP-dependent CL produced by the cells was significantly inhibited in a dose-dependent manner. CONCLUSIONS: NIM and 4-OHNIM may protect cartilage against oxidative stress, not only by scavenging ROS but also by inhibiting their production by chondrocytes. [less ▲]

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See detailIn vitro study of the antioxidant properties of non steroidal anti-inflammatory drugs by chemiluminescence and electron spin resonance (ESR).
Mouithys-Mickalad, Ange ULg; Zheng, S. X.; Deby-Dupont, G. P. et al

in Free Radical Research (2000), 33(5), 607-21

OBJECTIVES: To determine the antioxidant activities of nonsteroidal anti-inflammatory drugs (NSAIDS), we examined by chemiluminescence (CL) and electron spin resonance (ESR) their scavenging properties ... [more ▼]

OBJECTIVES: To determine the antioxidant activities of nonsteroidal anti-inflammatory drugs (NSAIDS), we examined by chemiluminescence (CL) and electron spin resonance (ESR) their scavenging properties towards lipid peroxides, hypochlorous acid and peroxynitrite. METHODS: The antioxidant properties of nimesulide (NIM), 4-hydroxynimesulide (4-HONIM), aceclofenac (ACLO), 4-hydroxyaceclofenac (4-HOA-CLO), diclofenac (DICLO) and indomethacin (INDO) were tested on four different reactive oxygen species (ROS) generating systems: (I) phorbol-myristate acetate (PMA)-activated neutrophils, (II) Fe2+/ascorbate-induced lipid peroxidation, (III) HOCl-induced light emission, (IV) the kinetics of ONOO- decomposition followed by spectrophotometry. ROS production was monitored by luminol-enhanced CL or by ESR using two different spin traps. RESULTS: At 10 microM, ACLO, NIM, 4-HONIM, 4-HOA-CLO, and DICLO decreased luminol-enhanced CL generated by PMA-activated neutrophils. Inversely, INDO increased the luminol enhanced CL. Interestingly, hydroxylated metabolites were more potent antioxidants than the parent drugs. Furthermore, all drugs tested, excepted ACLO, lowered lipid peroxidation induced by Fe2+/ascorbate system. ACLO and DICLO, even at the highest concentration tested (100 microM), did not significantly lower HOCl induced CL, whereas the other drugs were potent scavengers. Finally, all the NSAIDS accelerated decomposition of ONOO-, suggesting a potential capacity of the molecules to scavenge peroxynitrite. CONCLUSION: The NSAIDs possess variable degrees of antioxidant activities, linked to their ability to react with HOCl, lipid peroxides or ONOO-. These antioxidant activities could offer interesting targeted side-effects in the treatment of joint inflammatory diseases. [less ▲]

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See detailIn vitro study of the influence of temperature, pH and Aw on the growth rate of trichoderma aspergillum
Begoude, B. A. D.; Lahlali, R.; Friel, D. et al

in Bulletin OILB/SROP = IOBC/WPRS Bulletin (2007), 30

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See detailIn vitro study of the interactions between bovine herpesvirus 4 and the bovine host cells
Vanderplasschen, Alain ULg

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (1999), 154

This work was devoted to the study of the interactions between bovine herpesvirus 4 (BHV-4) and bovine cells in vitro. It led to the discovery of two interesting properties of BVH-4 replication cycle ... [more ▼]

This work was devoted to the study of the interactions between bovine herpesvirus 4 (BHV-4) and bovine cells in vitro. It led to the discovery of two interesting properties of BVH-4 replication cycle: first, the cellular receptor heparan sulfate was proven to mediate BVH-4 binding to target cells. This is the first description of the implication of heparan sulfate in the binding process of a gammaherpesvirus. Second, using synchronised cells, the replication of BVH-4 DNA was proven to be dependent on the S phase of the cell cycle. This dependence could explain some properties of BVH-4 infection in vitro and could play an important role in the biology of the infection in vivo. Finally, in order to produce monoclonal antibodies against BVH-4 IE1 and IE2 proteins, the genes coding for these proteins were cloned and expressed in prokaryotic cells. [less ▲]

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See detailIn vitro study on the effects of aceclofenac on proteoglycan and type II collagen production by human chondrocytes
Henrotin, Yves ULg; Labasse, A; Degroote, D et al

in Osteoarthritis and Cartilage (1997), 5

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See detailIn vitro survival of vitrified goat embryos: comparison of two vitrification methods
Guignot, F.; Baril, G.; Pougnard, J. L. et al

in Proceedings: 17e Réunion A.E.T.E. (2001)

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See detailIn vitro susceptibility of Clostridium perfringens isolated from farm animals to growth-enhancing antibiotics.
Devriese, L. A.; Daube, Georges ULg; Hommez, J. et al

in Journal of Applied Bacteriology (1993), 75

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