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See detailInteractions Between Heavy Metals and Nitrogen and Their Ecological Effects.
Zu, Yanqun; Li, Yuan; Bock, Laurent ULg et al

in Journal of Agro-Environment Science (2008), 27(1), 7-17

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See detailInteractions between IL-1bêta, IL-6, IL-8 and LIF produced by human chondrocytes
Henrotin; Franchimont, P; Reginster, Jean-Yves ULg

in The Official EULAR Journal for Education and Information (1995), 24

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See detailInteractions between IL-Ibêta, IL-6, IL-8, and LIF produced by human articular chondrocytes
Henrotin; Reginster, Jean-Yves ULg; Franchimont, P

in Osteoarthritis and Cartilage (1994), 2(S1), 52

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See detailInteractions between kinases and phosphatases in the rapid control of brain aromatase
Balthazart, Jacques ULg; Baillien, M.; Ball, G. F.

in Journal of Neuroendocrinology (2005), 17(9), 553-559

Aromatization of testosterone into oestradiol plays a key role in the activation of male sexual behaviour in many vertebrate species. Rapid changes in brain aromatase activity have recently been ... [more ▼]

Aromatization of testosterone into oestradiol plays a key role in the activation of male sexual behaviour in many vertebrate species. Rapid changes in brain aromatase activity have recently been identified and the resulting changes in local oestrogen bioavailability could modulate fast behavioural responses to oestrogens. In quail hypothalamic homogenates, aromatase activity is down-regulated within minutes by calcium-dependent phosphorylations in the presence of ATP, MgCl2 and CaCl2 (ATP/Mg/Ca). Three kinases (protein kinases A and C and calmodulin kinase; PKA, PKC and CAMK) are potentially implicated in this process. If kinases decrease aromatase activity in a reversible manner, then it would be expected that the enzymatic activity would increase and/or return to baseline levels in the presence of phosphatases. We showed previously that 0.1 mM vanadate (a general inhibitor of protein phosphatases) significantly decreases aromatase activity but specific protein phosphatases that could up-regulate aromatase activity have not been identified to date. The reversibility of aromatase activity inhibition by phosphorylations was investigated in the present study using alkaline and acid phosphatase (Alk and Ac PPase). Unexpectedly, Alk PPase inhibited aromatase activity in a dose-dependent manner in the presence, as well as in the absence, of ATP/Mg/Ca. By contrast, Ac PPase completely blocked the inhibitory effects of ATP/Mg/Ca on aromatase activity, even if it moderately inhibited aromatase activity in the absence of ATP/Mg/Ca. However, the addition of Ac PPase was unable to restore aromatase activity after it had been inhibited by exposure to ATP/Mg/Ca. Taken together, these data suggest that, amongst the 15 potential consensus phosphorylation sites identified on the quail aromatase sequence, some must be constitutively phosphorylated for the enzyme to be active whereas phosphorylation of the others is involved in the rapid inhibition of aromatase activity by the competitive effects of protein kinases and phosphatases. Two out of these 15 putative phosphorylation sites occur in an environment corresponding to the consensus sites for PKC, PKA (and possibly a CAMK) and, in all probability, represent the sites whose phosphorylation rapidly blocks enzyme activity. [less ▲]

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See detailInteractions between Lipopolysaccharides and Blood Factors on the Stimulation of Equine Polymorphonuclear Neutrophils
Benbarek, H.; Deby-Dupont, G.; Caudron, I. et al

in Veterinary Immunology & Immunopathology (1998), 64(4), 313-22

In horses, the mechanisms of lipopolysaccharide (LPS) stimulation of isolated neutrophils to produce reactive oxygen species remain unknown. We re-investigated this problem by monitoring the luminol ... [more ▼]

In horses, the mechanisms of lipopolysaccharide (LPS) stimulation of isolated neutrophils to produce reactive oxygen species remain unknown. We re-investigated this problem by monitoring the luminol-enhanced chemiluminescence (CL) produced by LPS-stimulated equine neutrophils. The neutrophils were isolated from horse blood by discontinuous density gradient centrifugation (> or = 99% neutrophils; viability > or = 98%). Increasing concentrations of Escherichia coli (E. coli) LPS (from 0.01-10 microg ml(-1)) were used to activate the neutrophils. When LPS was used directly, without another stimulator, the respiratory burst of neutrophils was not activated (N=12 horses; n=5 assays per horse). On the contrary, when LPS was added to whole blood, the neutrophils isolated from this blood were stimulated in a LPS dose-dependent manner, but polymyxin B added to whole blood suppressed this stimulation (N=2; n=6). LPS dissolved in autologous equine plasma stimulated the isolated neutrophils in a dose-dependent manner from 0.1-10 microg ml(-1) (N=5; n=12). Heat inactivation of the plasma abolished this CL increase (N=2; n=5). LPS added to equine albumin did not stimulate the isolated neutrophils (N=2; n=5). On the contrary, the addition of gamma-globulins (1 mg ml(-1)) to LPS (10 microg ml(-1)) led to the stimulation of neutrophils (N=2; n=5). We concluded that LPS did not directly stimulate the isolated equine neutrophils, but that plasmatic factors are needed for the stimulation of these cells by LPS. [less ▲]

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See detailInteractions between new phenolic glycolipids and model membrane
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg et al

Poster (2014, February 07)

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are ... [more ▼]

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are crucial to determine their potential as drug candidates and their cytotoxicity . [less ▲]

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See detailInteractions between non-classical β-lactam compounds and the β-lactamases of Actinomadura R39 and Streptomyces albus G
Kelly, Judith; Frère, Jean-Marie ULg; Duez, Colette ULg et al

in Biochemical Journal (1981), 199

Streptomyces albus G secretes a Zn2+-containing D-alanyl-D-alanine peptidase. Streptomyces R61 and Actinomadura R39 secrete D-alanyl-D-alanine-cleaving serine peptidases. The effect of non-classical beta ... [more ▼]

Streptomyces albus G secretes a Zn2+-containing D-alanyl-D-alanine peptidase. Streptomyces R61 and Actinomadura R39 secrete D-alanyl-D-alanine-cleaving serine peptidases. The effect of non-classical beta-lactam antibiotics on these three model enzymes has been studied. Mecillinam, cefoxitin, quinacillin, quinacillin sulphone, clavulanate and N-formimidoylthienamycin have no effect on the Zn2+-containing enzyme. 6-Amino-penicillanic acid slowly inactivates this enzyme and 7-aminocephalosporanic acid behaves as a reversible inhibitor. Cefoxitin and N-formimidoylthienamycin are potent anti-bacterial agents; they effectively inactivate the serine R39 enzyme and, to a lesser extent, the serine R61 enzyme. All the other beta-lactam compounds tested, including mecillinam, are slow inactivators of these serine enzymes. The intermediates formed between 6-aminopenicillanic acid and the R61 and R39 enzymes are long- and short-lived respectively, whereas those formed between 7-aminocephalosporanic acid and the same R61 and R39 enzymes are short- and long-lived respectively. Breakdown of the short-lived intermediates thus obtained gives rise to several ninhydrin-positive degradation products. The intermediates formed between clavulanate and the serine enzymes are long-lived. With the R39 enzyme, the inactivated complex formed in a first step undergoes subsequent monomolecular rearrangement to give rise to a second species exhibiting a high absorbance at 273 nm. [less ▲]

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See detailInteractions between numerical and physical modelling for the design and optimization of hydraulic structures - Example of a large hydroelectric complex
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of the International Symposium on Hydraulic Structures, XXII Congreso Latinoamericano de Hidráhulica (2006)

This paper describes the successful combination of both physical and numerical modelling techniques applied to the scale model study of a large hydroelectric complex in India. Thanks to accurate numerical ... [more ▼]

This paper describes the successful combination of both physical and numerical modelling techniques applied to the scale model study of a large hydroelectric complex in India. Thanks to accurate numerical simulations, the physical model layout and the time to studies have been drastically reduced. First, prior to the design of the scale model, a global numerical simulation of the dam reservoir has been carried out, on the basis of the entire set of available topographic data. The simulation results supply the flow conditions in the upstream reservoir, particularly in the vicinity of the dam and the spillway crest. Subsequently, a second numerical computation has been performed to simulate the flow in a scale model representing only a small part of the reservoir upstream of the dam. The suitable correspondence between flow conditions in both cases has been demonstrated. This two-steps approach has enabled a significant reduction in the size of the scale model, and hence, a lower cost as well as a shorter delay for building the model. Simultaneously, it has been possible to decrease the scale factor at constant cost. In conclusion, the present paper provides convincing evidence that the increase in computers performance and the efficiency of contemporary free-surface flow solvers lead to useful numerical information for the optimal design and exploitation of scale models. [less ▲]

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See detailInteractions between particles in a magnetocapillary self-assembly
Lagubeau, Guillaume ULg; Darras, Alexis; Grosjean, Galien ULg et al

Conference (2014, November 24)

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See detailInteractions between penicillin-binding proteins (PBPs) and two novel classes of PBP inhibitors, arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-ones
Zervosen, Astrid ULg; Lu, Wei-Ping; Chen, Zhouliang et al

in Antimicrobial Agents and Chemotherapy (2004), 48(3), 961-969

Several non-beta-lactam compounds were active against various gram-positive and gram-negative bacterial strains. The MICs of arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-ones were lower ... [more ▼]

Several non-beta-lactam compounds were active against various gram-positive and gram-negative bacterial strains. The MICs of arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-ones were lower than those of ampicillin and cefotaxime for methicillin-resistant Staphylococcus aureus M1339 and vancomycin-resistant Enterococcus faecium EF12. Several compounds were found to inhibit the cell wall synthesis of S. aureus and the last two steps of peptidoglycan biosynthesis catalyzed by ether-treated cells of Escherichia coli or cell wall membrane preparations of Bacillus megaterium. The effects of the arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-one derivatives on E. coli PBP 3 and PBP 5, Streptococcus pneumoniae PBP 2xS (PBP 2x from a penicillin-sensitive strain) and PBP 2xR (PBP 2x from a penicillin-resistant strain), low-affinity PBP 2a of S. aureus, and the Actinomadura sp. strain R39 and Streptomyces sp. strain R61 DD-peptidases were studied. Some of the compounds exhibited inhibitory activities in the 10 to 100 muM concentration range. The inhibition of PBP 2xS by several of them appeared to be noncompetitive. The dissociation constant for the best inhibitor (K-i = 10 muM) was not influenced by the presence of the substrate. [less ▲]

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See detailInteractions between polyamine and ethylene metabolisms in a hormone autonomous sugarbeet callus
Bisbis, Badia; Kevers, Claire ULg; Dommes, Jacques ULg et al

in Journal of Plant Physiology (2000), 157(1), 24-30

In a fully habituated non-organogenic sugarbeet callus (HNO) overproducing polyamines and underproducing ethylene (in comparison with its normal hormone-dependent counterpart), the question raised about a ... [more ▼]

In a fully habituated non-organogenic sugarbeet callus (HNO) overproducing polyamines and underproducing ethylene (in comparison with its normal hormone-dependent counterpart), the question raised about a possible competition between these two metabolites for their common precursor, S-adenosyl-methionine (SAM). The experimental strategy consisted in determining the effects of exogenous polyamines and inhibitors of polyamine biosynthetic pathway on growth, polyamine accumulation and ethylene production. Exogenous putrescine or spermidine decreased polyamine contents and ethylene production. Inhibitors of the diamine putrescine biosynthesis, DFMO and DFMA, induced a reduction of both polyamine content and ethylene production with an increase of HNO callus growth. However, when a mixture of the two inhibitors was used, an increase of ethylene production was observed without any effect on growth. The inhibitors of spermidine synthase (CHA) and of SAM decarboxylase (MGBG) also decreased polyamine content and ethylene production with different effects on growth according to the concentrations used. The combination of the two inhibitors (CHA + MGBG) increased ethylene production of the HNO callus. The effect of growth regulators (auxin and cytokinin) on growth and ethylene production of HNO callus is also discussed. These results suggest that polyamines affect directly the ethylene biosynthesis. In the absence of an exogenous hormonal control, the lower ethylene metabolism of HNO callus could not be explained by a competition with polyamines for their common precursor. [less ▲]

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See detailInteractions between Prolactin/Growth Hormone-Derived Peptides and PAI-1
D'Amico, Salvino ULg

Scientific conference (2010)

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See detailInteractions between systemic analgesics.
Joris, Jean ULg; Kaba, Abdourahmane ULg

in Acta Anaesthesiologica Belgica (2001), 52(4), 395-401

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See detailInteractions between the biofilm growth and the hydrodynamics in an aerobic trickling filter
Lekhlif, B.; Toye, Dominique ULg; Marchot, Pierre ULg et al

in Water Science & Technology (1994), 29

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See detailInteractions between the cytochrome pathway and the alternative oxidase in isolated Acanthamoeba castellanii mitochondria.
Jarmuszkiewicz, W.; Sluse, Francis ULg; Hryniewiecka, L. et al

in Journal of Bioenergetics & Biomembranes (2002), 34(1), 31-40

The steady-state activity of the two quinol-oxidizing pathways of Acanthamoeba castellanii mitochondria, the phosphorylating cytochrome pathway (i.e. the benzohydroxamate(BHAM)-resistant respiration in ... [more ▼]

The steady-state activity of the two quinol-oxidizing pathways of Acanthamoeba castellanii mitochondria, the phosphorylating cytochrome pathway (i.e. the benzohydroxamate(BHAM)-resistant respiration in state 3) and the alternative oxidase (i.e. the KCN-resistant respiration), is shown to be fixed by ubiquinone (Q) pool redox state independently of the reducing substrate (succinate or exogenous reduced nicotinamide adenine dinucleotide (NADH)), indicating that the active Q pool is homogenous. For both pathways, activity increases with the Q reduction level (up to 80%). However, the cytochrome pathway respiration partially inhibited (about 50%) by myxothiazol decreases when the Q reduction level increases above 80%. The decrease can be explained by the Q cycle mechanism of complex III. It is also shown that BHAM has an influence on the relationship between the rate of ADP phosphorylation and the Q reduction level when alternative oxidase is active, and that KCN has an influence on the relationship between the alternative oxidase activity and the Q reduction level. These unexpected effects of BHAM and KCN observed at a given Q reduction level are likely due to functional connections between the two pathways activities or to protein-protein interaction. [less ▲]

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See detailInteractions between the immune, endocrine and nervous systems
Geenen, Vincent ULg

Conference (1995, November)

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See detailInteractions between Tumoral Mcf7 Cells and Fibroblasts on Matrigel and Purified Laminin
Noël, Agnès ULg; Nusgens, Betty ULg; Lapiere, C. H. et al

in Matrix (Stuttgart, Germany) (1993), 13(4), 267-73

A reconstituted basement membrane (matrigel) and/or fibroblasts promote the growth of human breast tumors in athymic nude mice. We have investigated in vitro the effect of matrigel or purified ... [more ▼]

A reconstituted basement membrane (matrigel) and/or fibroblasts promote the growth of human breast tumors in athymic nude mice. We have investigated in vitro the effect of matrigel or purified glycoproteins (laminin and fibronectin) on tumoral MCF7 cells-fibroblasts interactions. In coculture on matrigel, MCF7 cells organized into clusters attached on top of fibroblasts aggregates. During the process resulting in tumor cells-fibroblasts aggregation, fibroblasts actively migrated while MCF7 cells were passively transported. Using purified proteins, specific antibodies and synthetic peptides, we show that cell aggregation induced by immobilized and soluble laminin is antagonized by exogenous fibronectin or fibronectin synthesized by fibroblasts. [less ▲]

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