Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Peer Reviewed
See detailModulation of Collagen and Fibronectin Synthesis in Fibroblasts by Normal and Malignant Cells
Noël, Agnès ULg; Munaut, Carine ULg; Boulvain, A. et al

in Journal of Cellular Biochemistry (1992), 48(2), 150-61

The influence of various normal and malignant human cells on the level of collagen synthesis by human fibroblasts was tested in coculture. As revealed by immunoperoxidase staining, in cocultures with ... [more ▼]

The influence of various normal and malignant human cells on the level of collagen synthesis by human fibroblasts was tested in coculture. As revealed by immunoperoxidase staining, in cocultures with breast adenocarcinoma cells (MCF7, SA52, T47D) fibroblasts synthesized collagen while tumor cells did not. Fibroblasts displayed increased collagen production without change in the overall protein synthesis. Several other types of cells derived from normal human tissues (keratinocytes, normal mammary cells) or from fibrosarcoma, melanoma, cervical carcinoma, choriocarcinoma, or other breast adenocarcinoma (SW613, MDA, BT20) did not affect collagen synthesis of fibroblasts. Although to a lesser extent, this stimulating effect was reproduced by using the conditioned medium (CM) of the active cells but not with CM of the other cell types. A slight stimulation was also obtained when tumoral MCF7 cells and fibroblasts shared the same medium but were physically separated, suggesting that close contact was required for optimal stimulation of collagen synthesis. The collagen synthesis stimulating activity was not related to a modification of fibroblast proliferation rate. The production of collagen types I, III, and VI and fibronectin were increased in cocultures of fibroblasts with MCF7 cells. The increased synthesis of collagen types I and III and fibronectin was paralleled by similar changes in the steady-state level of their mRNAs. On the contrary, the increased production of collagen type VI appeared regulated at a post-transcriptional level. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Full Text
Peer Reviewed
See detailModulation of CYP1A1 activity by a Ginkgo biloba extract in the human intestinal Caco-2 cells
Ribonnet, Laurence; Callebaut, Alfons; Nobels, Ingrid et al

in Toxicology Letters (2011), 202(3), 193-202

Detailed reference viewed: 13 (3 ULg)
Peer Reviewed
See detailModulation of cytochrome P450 1A1 expression and activity in intestinal Caco-2 cells by components of Ginkgo biloba-based dietary supplements
Ribonnet, Laurence; Callebaut, Alfons; Scippo, Marie-Louise ULg et al

in Toxicology Letters (2009), 189

Detailed reference viewed: 34 (12 ULg)
See detailModulation of Dayside Reconnection During Northward IMF
Provan, G.; Lester, M.; Cowley, S. W. et al

Poster (2005, December 01)

On 17 September 2000 the IMF was directed continuously northward for more than three hours. Density fluctuations in the solar wind resulted in quasi-periodic variations in the solar wind dynamic pressure ... [more ▼]

On 17 September 2000 the IMF was directed continuously northward for more than three hours. Density fluctuations in the solar wind resulted in quasi-periodic variations in the solar wind dynamic pressure, and correlated fluctuations also occurred in the IMF Bz component. The Northern hemisphere SuperDARN radars observed bursts of high-latitude high-velocity plasma flow during this northward IMF interval, both when ionospheric signatures consistent with low-latitude merging were observed, and when lobe merging was occurring. On average the recurrence period of these flow bursts was ~22 min. During this time the SI-12 spectrographic imager channel on the IMAGE spacecraft observed the dayside proton auroral spot continuously (Frey et al., 2003). The brightness of the auroral spot varied over time. Here we find a direct correlation between the occurrence of bursts of plasma flow and periodic fluctuations in the brightness of the proton auroral spot. Our results suggest that correlated fluctuations in the solar wind dynamic pressure and IMF Bz component modulated ionospheric precipitation and dayside reconnection, resulting in fluctuations in the brightness of the proton auroral spot and periodic variations in the dayside high-latitude plasma flow. [less ▲]

Detailed reference viewed: 9 (0 ULg)
Full Text
Peer Reviewed
See detailModulation of dayside reconnection during northward interplanetary magnetic field
Provan, G.; Lester, M.; Cowley, S. W. H. et al

in Journal of Geophysical Research. Space Physics (2005), 110(A10),

On 17 September 2000 the IMF was directed continuously northward for more than 3 hours. Density fluctuations in the solar wind resulted in quasiperiodic variations in the solar wind dynamic pressure, and ... [more ▼]

On 17 September 2000 the IMF was directed continuously northward for more than 3 hours. Density fluctuations in the solar wind resulted in quasiperiodic variations in the solar wind dynamic pressure, and correlated fluctuations also occurred in the IMF B-z component. The Northern Hemisphere SuperDARN radars observed bursts of high-latitude high-velocity plasma flow during this northward IMF interval, both when ionospheric signatures consistent with low-latitude merging were observed and when lobe merging was occurring. On average the recurrence period of these flow bursts was similar to 22 min. During this time the SI-12 spectrographic imager channel on the IMAGE spacecraft observed the dayside proton auroral spot continuously (Frey et al., 2003a). The brightness of the auroral spot varied over time. Here we find a direct correlation between the occurrence of bursts of plasma flow and periodic fluctuations in the brightness of the proton auroral spot. Our results suggest that correlated fluctuations in the solar wind dynamic pressure and IMF Bz component modulated ionospheric precipitation and dayside reconnection, resulting in fluctuations in the brightness of the proton auroral spot and periodic variations in the dayside high-latitude plasma flow. [less ▲]

Detailed reference viewed: 4 (1 ULg)
Peer Reviewed
See detailModulation of dendritic cell phenotype by PGD2 and PGJ2 : consequence on the orientation of T helper response
Gosset, P.; Bureau, Fabrice ULg; Angeli, V. et al

in Proceedings : International Conference of the American Thoracic Society (2002)

Detailed reference viewed: 10 (0 ULg)
Peer Reviewed
See detailModulation of expression and assembly of vinculin during in vitro fibrillar collagen-induced angiogenesis and its reversal.
Deroanne, Christophe ULg; Colige, Alain ULg; Nusgens, Betty ULg et al

in Experimental Cell Research (1996), 224(2), 215-23

A model of collagen-induced in vitro angiogenesis was used to investigate the modulation of expression and assembly of focal adhesion plaque-associated proteins during the process of differentiation ... [more ▼]

A model of collagen-induced in vitro angiogenesis was used to investigate the modulation of expression and assembly of focal adhesion plaque-associated proteins during the process of differentiation. Human umbilical vein endothelial cells (HUVEC), first attached on an adhesive substratum (gelatin-, fibronectin-, or laminin-coated dish) or adherent collagen gel and then covered by an overlaying collagen get, organized within 3-4 days in tube-like structures (TLS). Removing the overlaying collagen gel from fully differentiated HUVEC induced a reversion of the process and HUVEC returned to a monolayer pattern. Modulations of focal adhesion-associated proteins occurring in HUVEC during the in vitro differentiation process and its reversal were investigated by Western blot analysis. A significant decrease of expression of vinculin, the integrin alpha2 subunit, talin, alpha-actinin, and actin was observed in TLS whereas the amount of FVIII-related antigen did not vary as compared to control monolayer cultures. During reversal, all the reduced proteins were markedly reexpressed. Human skin fibroblasts (HSF), submitted to the same experimental conditions, did not form TLS. Most of the focal adhesion proteins in HSF were similarly modulated by an overlaying collagen gel with the exception of vinculin, which was not modified. This particular protein was therefore more thoroughly investigated. In a nondifferentiated monolayer of HUVEC, a significant proportion of vinculin was organized into a detergent-resistant juxtamembranous structure (focal adhesion plaque) which disassembled early in TLS formation and reassembled during the reversal of the process. The reduction of vinculin during TLS formation was preceded by a downregulation of its mRNA while this mRNA was upregulated during reversal of the morphotype. These results suggest that the modulations of the cytoskeletal and focal adhesion proteins and more specifically of vinculin coupled to its subcellular redistribution are critical and early events in the cascade of mechanochemical signaling during in vitro angiogenesis induced by fibrillar collagen. [less ▲]

Detailed reference viewed: 18 (4 ULg)
Full Text
Peer Reviewed
See detailModulation of fibrinolytic and gelatinolytic activity during adipose tissue development in a mouse model of nutritionally induced obesity
Lijnen, Roger; Maquoi, Erik ULg; Demeulemeester, Désiré et al

in Thrombosis and Haemostasis (2002), 88(2), 345-353

A nutritionally induced obesity model was used to investigate the modulation of fibrinolytic and gelatinolytic activity during the development of adipose tissue. Five week old male mice were fed a ... [more ▼]

A nutritionally induced obesity model was used to investigate the modulation of fibrinolytic and gelatinolytic activity during the development of adipose tissue. Five week old male mice were fed a standard fat diet (SFD, 13% kcal as fat) or a high fat diet (HFD, 42% kcal as fat) for up to 15 weeks. The HFD resulted in body weights of 31 +/- 0.9 g, 38 +/- 2.0 g and 47 +/- 1.9 g at 5, 10 and 15 weeks, respectively; corresponding values for mice on the SFD were 26 +/- 0.6 g, 31 +/- 0.9 g and 31 +/- 1.2 g (all p < 0.001). The weight of the isolated subcutaneous (s.c.) or gonadal (GON) fat after 15 weeks of HFD was 1,870 +/- 180 mg or 1,470 +/- 160 mg, as compared to 250 +/- 58 mg or 350 +/- 71 mg for the SFD (p < 0.001). The HFD induced marked time-dependent hyperglycemia and elevated levels of triglycerides and total cholesterol. The HFD diet also induced a marked hypertrophy of the adipocytes as compared to the SFD, e.g. diameter of 83 +/- 3.0 microns versus 52 +/- 4.2 microns for GON adipocytes at 15 weeks (p < 0.005). Plasma plasminogen activator inhibitor-1 (PAI-1) levels were higher in mice on the HFD as compared to the SFD; they were comparable in extracts of s.c. or GON adipose tissue, whereas at different time points tissue-type (t-PA) and urokinase-type (u-PA) plasminogen activator activity was somewhat lower in the adipose tissues of mice on HFD. Gelatinolytic activity (mainly MMP-2) was detected in s.c. but not in GON adipose tissue of mice on SFD, and decreased on the HFD. In situ zymography on cryosections did not reveal different fibrinolytic activities in s.c. or GON adipose tissues of the HFD as compared to the SFD groups, whereas significantly lower gelatinolytic and higher caseinolytic activities were detected in s.c. and GON tissues of mice on the HFD (p < or = 0.05). The fibrillar collagen content was lower in adipose tissue of mice on HFD. Thus, in this model time-dependent development of adipose tissue appears to be associated with modulation of proteolytic activity. [less ▲]

Detailed reference viewed: 16 (2 ULg)
Full Text
Peer Reviewed
See detailModulation of fMRI assessed brain responses to blue and green light by sleep homeostasis, circadian phase and PER3 polymorphism
Vandewalle, Gilles ULg; Archer, Simon; Wuillaume, Catherine et al

in Sleep (2009), 32(Suppl. 1),

Detailed reference viewed: 16 (2 ULg)
Peer Reviewed
See detailModulation of growth hormone action by active immunization in dairy cows.
Vleurick, L.; Bertozzi, C.; Haezebroek, V. et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2000), 4(1),

Detailed reference viewed: 3 (1 ULg)
Peer Reviewed
See detailModulation of growth hormone action by active immunization in dairy cows.
Vleurick, Lieve; Deaver, D.; Bertozzi, Carlo et al

in 1st Belgian Workshop on Animal Endocrinology (1999, October 13)

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailModulation of homing properties of primitive progenitor cells generated by ex vivo expansion.
Foguenne, Jacques ULg; Huygen, Sandra; Greimers, Roland ULg et al

in Haematologica (2005), 90(4), 445-51

BACKGROUND AND OBJECTIVES: The maintenance of adequate interactions with the bone marrow (BM) microenvironment is critical to ensure efficient homing of ex vivo-expanded hematopoietic cells. This study ... [more ▼]

BACKGROUND AND OBJECTIVES: The maintenance of adequate interactions with the bone marrow (BM) microenvironment is critical to ensure efficient homing of ex vivo-expanded hematopoietic cells. This study was intended to assess adhesion and migration properties of long-term culture-initiating cells (LTC-IC) harvested after self-renewal division in ex vivo culture and to determine their susceptibility to growth-inhibitory signals mediated by adhesion to BM stromal ligands. DESIGN AND METHODS: We used cell tracking to isolate primitive LTC-IC that had accomplished 1 or 2 divisions ex vivo. Adhesion, migration and growth inhibition of divided LTC-IC were determined in the presence of purified BM ligands, and compared to the properties of uncultured LTC-IC. RESULTS: As compared to undivided LTC-IC, adhesion and migration mediated by very late antigen (VLA)-4 integrin across both vascular cell adhesion molecule-1 (VCAM-1) and fibronectin (Fn) were downregulated in post-mitotic LTC-IC. Conversely, binding and motility via VLA-5 across Fn were stimulated. No changes occurred in LTC-IC interactions with intercellular adhesion molecule-1 (ICAM-1) or with E- or P-selectin. Proliferation of uncultured LTC-IC was inhibited by VLA-4-mediated binding to VCAM-1 and the CS-1 domain of Fn, as well as binding to P-selectin. Growth of ex vivo-generated LTC-IC became unresponsive to these 3 ligands but was suppressed through VLA-5 engagement by the cell binding domain of Fn. INTERPRETATION AND CONCLUSIONS: The generation of LTC-IC in expansion culture is associated with functional alterations of adhesion receptors, modulating not only binding and migration in the BM but also responsiveness to adhesion-mediated growth inhibitory signals. Such changes may limit homing and engraftment of expanded primitive stem/progenitor cells. [less ▲]

Detailed reference viewed: 26 (5 ULg)
Full Text
Peer Reviewed
See detailModulation of hormonal signaling in the brain by steroid receptor coactivators.
Charlier, Thierry ULg; Balthazart, Jacques ULg

in Reviews in the Neurosciences (2005), 16(4), 339-57

Nuclear receptors, such as estrogen, glucocorticoid or thyroid hormone receptors, have been shown to play a critical role in brain development and physiology. The activity of these receptors is modulated ... [more ▼]

Nuclear receptors, such as estrogen, glucocorticoid or thyroid hormone receptors, have been shown to play a critical role in brain development and physiology. The activity of these receptors is modulated by the interaction with several proteins and, in particular, coactivators are required to enhance their transcriptional activity. The steroid receptor coactivators (SRC-1, -2 and -3) are currently the best characterized coactivators and we review here the current knowledge on the distribution and function of these proteins in the brain. Knock-out models and antisense techniques have demonstrated the requirement for SRC-1 and -2 in the brain, focusing mainly on steroid and thyroid hormone-dependent development and behavior. The precise function of SRC-3 in the brain is currently unknown but its presence throughout the brain suggests an important function. Although the molecular biology of SRCs is relatively well known, the in vivo control of their expression, post-translational modifications and time- and cell-specific interactions with the different nuclear receptors remain elusive. A complete understanding of hormone action on brain and behavior will not be attained until a better knowledge of coactivator physiology is achieved. [less ▲]

Detailed reference viewed: 23 (3 ULg)
Full Text
Peer Reviewed
See detailModulation of human chondrocyte metabolism by recombinant human interferon.
Henrotin, Yves ULg; Zheng, S X; Labasse, A H et al

in Osteoarthritis and Cartilage (2000), 8(6), 474-82

OBJECTIVES: Interferon gamma (IFN gamma) is found to be elevated in the synovial fluid of patients with rheumatoid arthritis and osteoarthritis, suggesting its implication in joint disease pathogenesis ... [more ▼]

OBJECTIVES: Interferon gamma (IFN gamma) is found to be elevated in the synovial fluid of patients with rheumatoid arthritis and osteoarthritis, suggesting its implication in joint disease pathogenesis. In this study, we investigated the effects of IFN gamma on the production of cytokines (IL-6, IL-8, IL-10), prostaglandin E(2)(PGE(2)), proteoglycans (PG), nitric oxide (NO), interleukin-1 receptor antagonist (IL-1ra) and stromelysin by non-stimulated and IL-1 beta-treated human chondrocytes. The role played by NO in the responses of chondrocytes to IFN gamma was also examined by incubation of chondrocytes with N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of NO synthase. METHODS: Enzymatically isolated human chondrocytes were cultured for 48 h in the absence or presence of IL-1 beta, IFN gamma or N(G)-monomethyl-L-arginine (L-NMMA) added solely or in combination. The productions of IL-6, IL-8, IL-10, IL-1ra and stromelysin were measured by enzyme amplified sensitivity immunoassays (EASIA). PG and PGE(2)were quantified by specific radioimmunoassays (RIA). Nitrite concentrations in the culture supernatants were determined by a spectrophotometric method based upon the Griess reaction. RESULTS: As expected, IL-1 beta highly stimulated NO, IL-6, IL-8, IL-10, IL-1ra, PGE(2)and stromelysin synthesis, but dramatically decreased PG production. NO, IL-6, IL-1ra and PGE(2)production by non-stimulated chondrocytes was dose-dependently increased by IFN gamma while PG production was inhibited. In the absence of IL-1 beta, IL-10 was undetectable in the culture supernatants. At the doses of 10 and 100 U/ml, IFN gamma markedly inhibited the constitutive and IL-1 beta-stimulated IL-8, IL-10 and stromelysin productions. Interestingly, IFN gamma synergized with IL-1 beta to increase NO, IL-6, IL-1ra and to depress PG production. As previously reported, the inhibition of NO synthesis by the competitive inhibitor L-NMMA led to enhancement of IL-6, IL-8 and PGE(2)production by IL-1 beta treated chondrocytes, but did not significantly modify IL-10, PG and MMP-3 productions. Inhibition of NO synthase significantly inhibited the stimulating effect of IFN gamma on IL-6 and IL-1ra but did not affect the inhibitory effect of IFN gamma on IL-8, PG or stromelysin production. CONCLUSIONS: These findings suggest that IFN gamma and IL-1 synergistically stimulate the production of IL-6, IL-1ra, NO and PGE(2)and inhibit PG synthesis. By contrast, IL-1 beta and IFN gamma have opposite effects on IL-8, IL-10 and stromelysin productions. These effects are not reversed by L-NMMA, suggesting that NO is not the principal mediator involved in responses of chondrocytes to IFN gamma. [less ▲]

Detailed reference viewed: 30 (4 ULg)
Peer Reviewed
See detailModulation of Immunological Histamine Release from Human Lung Fragments by Stem Cell Factor, Il-3, Il-5 and Gm-Csf: Comparison with Human Leukocytes
Louis, Renaud ULg; Dowlati, A.; Weber, T. et al

in International Archives of Allergy & Immunology (1994), 105(1), 18-25

Because of the importance of cytokines in the regulation of allergic inflammation, we investigated the effects of SCF, IL-3, IL-5 and GM-CSF on immunological histamine release from sensitized human lung ... [more ▼]

Because of the importance of cytokines in the regulation of allergic inflammation, we investigated the effects of SCF, IL-3, IL-5 and GM-CSF on immunological histamine release from sensitized human lung fragments as well as human leukocytes. SCF (0.2-20 ng/ml) caused a concentration-related enhancement of anti-IgE (1/100) induced histamine release from lung fragments reaching maximally 64% at 20 ng/ml. In contrast, enhancement produced by IL-5, IL-3 and GM-CSF (0.2-20 ng/ml) was quite marginal and reached at best around 20% at the higher concentration, IL-5 being slightly more effective than IL-3 and GM-CSF. Further, SCF potentiated histamine release whatever the level of immunological control whereas potentiation by IL-5 primarily occurred when the amount of histamine release induced by the immunological control ranged between 5 and 10%. SCF acted synergistically with IL-5, producing a greater enhancement of histamine release than the sum of each cytokine used alone. Both SCF and, to a lesser extent, IL-5 potentiated anti-IgE-mediated histamine release regardless of passive sensitization of lung fragments. Unlike what was observed with lung fragments, IL-3, GM-CSF and to a lesser extent IL-5, were potent enhancing agents of anti-IgE (1/2,000)-induced histamine release from leukocytes. Maximal enhancement produced by IL-3 (20 ng/ml), GM-CSF (2 ng/ml) and IL-5 (20 ng/ml) reached 92%, 78% and 61%, respectively. By contrast, SCF (0.2-20 ng/ml) was ineffective on human leukocytes.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailModulation of intestinal urea cycle by dietary spermine in suckling rat
Gharbi, Myriam ULg; Powroznik, Brigitte; Mazzucchelli, Gabriel ULg et al

in Biochemical and Biophysical Research Communications (2005), 336(4), 1119-1124

Argininosuccinate synthetase, an ubiquitous enzyme in mammals, catalyses the formation of argininosuccinate, the precursor of arginine. Arginine is recognised as an essential amino acid in foetuses and ... [more ▼]

Argininosuccinate synthetase, an ubiquitous enzyme in mammals, catalyses the formation of argininosuccinate, the precursor of arginine. Arginine is recognised as an essential amino acid in foetuses and neonates, but also as a conditionally essential amino acid in adults. Argininosuccinate synthetase is initially expressed in enterocytes during the developmental period, it disappeared from this organ then appeared in the kidneys. Although the importance of both intestinal and renal argininosuccinate synthetases has been recognised for a long time, nutrients have not yet been identified as inducers of the gene expression. In the context of a proteomic screening of intestinal modifications induced by dietary spermine in suckling rats, we showed that argininosuccinate synthetase and carbamoyl phosphate synthase disappeared from enterocytes after this treatment. The disappearance of argininosuccinate synthetase in small intestine was confirmed by immunodetection. Expression of carbamoyl phosphate synthase and argininosuccinate synthetase coding genes decreased also after spermine administration. Expression of other urea cycle enzyme coding genes was modulated by spermine administration: argininosuccinate lyase decreased and arginase increased. Our results fit with the developmental variation of argininosuccinate synthetase and carbamoyl phosphate synthase. Modulation of the gene expression for several urea cycle enzymes suggests a coordination between all the pathway steps and switch toward polyamine (or proline and glutamate) biosynthesis from ornithine. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 62 (10 ULg)