References of "Dandrifosse, Guy"
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See detailPreliminary characterization of jejunocyte and colonocyte cell lines isolated by enzymatic digestion from adult and young cattle.
Loret, Suzanne; Rusu, Dorina; Moualij, Benaissa El et al

in Research in Veterinary Science (2009), 87(1), 123-32

In the present study we developed an enzymatic approach (through the use of collagenase and dispase) to isolate bovine intestinal epithelial cells. Using this method, freshly isolated jejunocytes could be ... [more ▼]

In the present study we developed an enzymatic approach (through the use of collagenase and dispase) to isolate bovine intestinal epithelial cells. Using this method, freshly isolated jejunocytes could be distinguished from simultaneously isolated colonocytes, as the jejunocytes specifically exhibited the small intestinal peptidase gene transcript, as well as an active alkaline phosphatase. The transformation of both types of cell suspension was performed by retroviral infection, using reproduction-defective viruses bearing the gene coding for the large T antigen of the leukaemia simian virus (SV40). The success of the transfection was demonstrated by (1) a significant increase in cell passage numbers (52-53 vs. 7 passages for non-transfected cells), (2) the detection of both the large T transcript and the large T antigen in transformed cells. Possible contamination and progressive substitution of bovine primocultures by non-bovine lineages available in the laboratory was excluded, as the transformed cells presented a bovine typical karyotype. Most transfected cells kept an epithelial morphology after transformation. They also maintained the expression of FABP and enterocyte specific enzymes (brush-border associated maltase and IAP). However, levels of specific activity of these enzymes were low, suggesting that cell differentiation is not completely achieved under the applied culture conditions. [less ▲]

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See detailStudy on the effects of laminarin, a polysaccharide from seaweed, on gut characteristics
Deville, Christelle ULg; Gharbi, Myriam ULg; Dandrifosse, Guy ULg et al

in Journal of the Science of Food and Agriculture (2007), 87(9), 1717-1725

This study investigates whether laminarin (beta 1-3,beta 1-6-glucan), a polysaccharide from seaweed, exhibits beneficial properties for human health by analysing its effects on intestinal parameters ... [more ▼]

This study investigates whether laminarin (beta 1-3,beta 1-6-glucan), a polysaccharide from seaweed, exhibits beneficial properties for human health by analysing its effects on intestinal parameters. Anaerobic batch culture fermenters were used for the screening of the in vitro utilization of laminarin by the human gut microflora through the monitoring of biochemical and microbiological parameters. Additionally, the influence of laminarin ingestion on the composition of intestinal mucus (neutral mucins, sialomucins and sulphomucins) was studied in rats. Laminarin was almost totally (more than 90% used) fermented after 24 h of incubation with human intestinal bacteria. It was not selectively used by bifidobacteria and lactobacilli, but increased the production of propionate and butyrate. Variations of mucus composition were observed in jejunum, ileum, caecum and colon, both in lumen content and in intestinal wall, of rats after ingestion of this polysaccharide. Due to its effects on mucus composition, laminarin could influence the adherence and the translocation of bacteria across the epithelial wall. In conclusion, laminarin seems to be a modulator of the intestinal metabolism by its effects on mucus composition, intestinal pH and short chain fatty acid (SCFA) production, especially butyrate. (c) 2007 Society of Chemical Industry. [less ▲]

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See detailDevelopment of a serum-free co-culture of human intestinal epithelium cell-lines (Caco-2/HT29-5M21)
Nollevaux, Géraldine; Deville, Christelle ULg; Elmoualij, Benaïssa ULg et al

in BMC Cell Biology (2006), 7

Background: The absorptive and goblet cells are the main cellular types encountered in the intestine epithelium. The cell lineage Caco-2 is a model commonly used to reproduce the features of the bowel ... [more ▼]

Background: The absorptive and goblet cells are the main cellular types encountered in the intestine epithelium. The cell lineage Caco-2 is a model commonly used to reproduce the features of the bowel epithelium. However, there is a strong debate regarding the value of Caco-2 cell culture to mimick in vivo situation. Indeed, some authors report in Caco-2 a low paracellular permeability and an ease of access of highly diffusible small molecules to the microvilli, due to an almost complete lack of mucus. The HT29-5M21 intestinal cell lineage is a mucin-secreting cellular population. A co-culture system carried out in a serum-free medium and comprising both Caco-2 and HT29-5M21 cells was developed. The systematic use of a co-culture system requires the characterization of the monolayer under a given experimental procedure. Results: In this study, we investigated the activity and localization of the alkaline phosphatase and the expression of IAP and MUC5AC genes to determine a correlation between these markers and the cellular composition of a differentiated monolayer obtained from a mixture of Caco-2 and HT29-5M21 cells. We observed that the culture conditions used ( serum-free medium) did not change the phenotype of each cell type, and produced a reproducible model. The alkaline phosphatase expression characterizing Caco-2 cells was influenced by the presence of HT29-5M21 cells. Conclusion: The culture formed by 75% Caco-2 and 25% HT29-5M21 produce a monolayer containing the two main cell types of human intestinal epithelium and characterized by a reduced permeability to macromolecules. [less ▲]

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See detailIn vitro transport studies of nifedipine nanoparticles across Caco-2/HT29- 5M21 cultures and co-cultures
Hecq, Julien; Nollevaux, Géraldine; Deleers, M. et al

Poster (2006)

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See detailNifedipine nanocrystals: pharmacokinetic evaluation in the rat and permeability studies in Caco-2/HT29-5M21 (co)-cultures
Hecq, Julien; Nollevaux, Géraldine; Deleers, M. et al

in Journal of Drug Delivery Science and Technology (2006), 16(6, NOV-DEC), 437-442

Poorly water-soluble drugs such as nifedipine (NIF) (similar to 20 mu g/mL) offer challenging problems in drug formulation as poor solubility is generally associated with poor dissolution characteristics ... [more ▼]

Poorly water-soluble drugs such as nifedipine (NIF) (similar to 20 mu g/mL) offer challenging problems in drug formulation as poor solubility is generally associated with poor dissolution characteristics and thus with poor oral bioavailability (BCS class H drugs). In order to enhance these characteristics, formulation of NIF as nanocrystals was carried out. NIF nanoparticles (NP) were prepared using high-pressure homogenization (HPH). Solubility and dissolution characteristics have been reported in previous work to be significantly enhanced for NIF NP. Influence of NIF particle size on NIF permeation rate across intestinal cell models (Caco-2 and HT29-5M21 cultures and co-cultures) was investigated in order to complement these promising in vitro data. Apical to basolateral transfer studies were carried out across Caco-2 and HT29-5M21 cultures and co-cultures. Caco-2/HT29-5M21 co-cultures (seeding ratio 3: 1) were evaluated to better represent in vivo intestinal conditions. The influence of chitosan in the NIF NP formulation with regard to in vitro NIF permeation rate was also evaluated. These studies showed that NIF permeation rate across the different in vitro models evaluated can be significantly enhanced (approximate to 6-fold) by formulation of NIF as nanoparticles. No significant difference was observed either in the presence of chitosan in the formulation or between the three cell models evaluated. To complement these observations, preliminary in vivo pharmacokinetic evaluations in Sprague-Dawley rats, in the fed and fasted states, were also carried out for both un-milled NIF and NIF NP. [less ▲]

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See detailImmunochemical, biomolecular and biochemical characterization of bovine epithelial intestinal primocultures
Rusu, D.; Loret, S.; Peulen, Olivier ULg et al

in BMC Cell Biology (2005), 6

Background: Cultures of enterocytes and colonocytes represent valuable tools to study growth and differentiation of epithelial cells. In vitro models may be used to evaluate passage or toxicity of drugs ... [more ▼]

Background: Cultures of enterocytes and colonocytes represent valuable tools to study growth and differentiation of epithelial cells. In vitro models may be used to evaluate passage or toxicity of drugs, interactions of enteropathogenes bacteria strains with intestinal epithelium and other physiologic or pathologic phenomenon involving the digestive tract. Results: Cultures of bovine colonocytes and jejunocytes were obtained from organoid-enriched preparations, using a combination of enzymatic and mechanical disruption of the intestine epithelium, followed by an isopicnic centrifugation discarding most single cells. Confluent cell monolayers arising from plated organoids exhibited epithelium typical features, such as the pavement-like structure, the presence of apical microvilli and tight junctions. Accordingly, cells expressed several markers of enterocyte brush border (i.e. maltase, alkaline phosphatase and fatty acid binding protein) as well as an epithelial cytoskeleton component (cytokeratin 18). However, enterocyte primocultures were also positive for the vimentin immunostaining (mesenchyme marker). Vimentin expression studies showed that this gene is constitutively expressed in bovine enterocytes. Comparison of the vimentin expression profile with the pattern of brush border enzymes activities, suggested that the decrease of cell differentiation level observed during the enterocyte isolation procedure and early passages of the primoculture could result from a post-transcriptional de-repression of vimentin synthesis. The low differentiation level of bovine enterocytes in vitro could partly be counteracted adding butyrate (1-2 mM) or using a glucose-deprived culture medium. Conclusion: The present study describes several complementary approaches to characterize bovine primary cultures of intestinal cells. Cultured cells kept their morphologic and functional characteristics during several generations. [less ▲]

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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 ▲]

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See detailIntestinal effects of long-lasting spermine ingestion by suckling rats
Deloyer, Patricia; Peulen, Olivier ULg; Dandrifosse, Guy ULg

in Experimental Physiology (2005), 90(6), 901-908

Spermine ingestion induces the precocious maturation of the small intestine in suckling rats. Previous observations suggest that spermine-induced intestinal maturation is a two-step phenomenon. The first ... [more ▼]

Spermine ingestion induces the precocious maturation of the small intestine in suckling rats. Previous observations suggest that spermine-induced intestinal maturation is a two-step phenomenon. The first step is the elimination of immature enterocytes (4-10 h post spermine ingestion) and the second step is the replacement of previous immature cells by adult-type enterocytes (2-3 days post initial spermine administration). The spermine-induced maturation is reversible when spermine administration is stopped. This work was undertaken in order to check whether the extension of polyamine administration (for 3-7 days) after the appearance of spermine-induced maturation can retain the mature state of the small intestine. Our results indicate that extension of spermine administration does not prevent some parameters (sucrase and maltase specific activities) reverting to a typical 'immature' value while others remain at a typical 'mature' level (mucosal weight and lactase specific activity). Our results show that there are at least two different mechanisms in required for the control of spermine-induced maturation of the small intestine. [less ▲]

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See detailPostnatal maturation of intestine and spleen, induced by polyamines in suckling rats
Peulen, Olivier ULg; Deloyer, Patricia; Dandrifosse, Guy ULg

in Morgan, D.; Bauer, F.; White, A. (Eds.) COST 917 Biologically active amines in food. Volume VII (2005)

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See detailMaturation of intestinal digestive and immune systems by food polyamines
Peulen, Olivier ULg; Deloyer, Patricia; Dandrifosse, Guy ULg

in Zabielski, R.; Gregory, P. C.; Weström, B. (Eds.) Biology of the Intestine in Growing Animals (2005)

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See detailEnhancement of transfection efficiency through rapid and noncovalent post-PEGylation of poly(dimethylaminoethyl methacrylate)/DNA complexes
Pirotton, S.; Muller, Caroline; Pantoustier, N. et al

in Pharmaceutical Research (2004), 21(8), 1471-1479

Purpose. The aim of this work was to develop a new strategy to introduce poly(ethylene glycol) (PEG) into methacrylate-based polymer/ DNA complexes in order to produce hemocompatible particles able to ... [more ▼]

Purpose. The aim of this work was to develop a new strategy to introduce poly(ethylene glycol) (PEG) into methacrylate-based polymer/ DNA complexes in order to produce hemocompatible particles able to transfect cells in the presence of serum. Methods. Atom transfer radical polymerization was used to synthesize a well-defined poly(2-(dimethylamino) ethyl methacrylate) homopolymer ( PDMAEMA) and a poly( 2-( dimethylamino) ethyl methacrylate-b-poly( ethylene glycol) alpha-methyl ether, omega-methacrylate) palm-tree-like copolymer (P(DMAEMA-b-MAPEG)). The complexes obtained by self assembly of the pCMVbeta plasmid and the polymers were used to transfect Cos-7 cells. Their physical properties - particle size and zeta potential - were characterized respectively by dynamic light scattering and electrophoretic mobility measurements. Ex vivo hemocompatibility was also determined. Results. The PDMAEMA/pCMVbeta complexes transfected Cos-7 cells exclusively in the absence of serum. Although the P(DMAEMA-b-MAPEG) copolymer had no transfection activity per se, the addition of the latter to pre-formed PDMAEMA/DNA complexes significantly enhanced the activity and allowed transfection even in the presence of serum. The presence of palm-tree - like copolymers also improved the hemocompatibility properties of the complexes. No effect on platelet counts was observed for P(DMAEMA-b-MAPEG)/ pCMVbeta complexes, whereas a decrease of platelets was clearly observed when blood cells were incubated with PDMAEMA/pCMVbeta complexes. Conclusions. Such a synergistic effect of noncovalent PEGylation of poly( amino methacrylate)/ DNA complexes allows a new and versatile approach to tune up transfection efficiency. [less ▲]

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See detailLaminarin in the dietary fibre concept
Deville, Christelle ULg; Damas, Jacques ULg; Forget, Pierre et al

in Journal of the Science of Food and Agriculture (2004), 84(9), 1030-1038

Dietary fibres consist of edible plant polysaccharides that are resistant to digestion and absorption in the human small intestine but undergo complete or partial fermentation in the colon. Seaweeds ... [more ▼]

Dietary fibres consist of edible plant polysaccharides that are resistant to digestion and absorption in the human small intestine but undergo complete or partial fermentation in the colon. Seaweeds, notably Laminaria spp, are particularly rich in polysaccharides resistant to hydrolysis in the upper gastrointestinal tract and are, in consequence, considered as dietary fibres. Most of the carbohydrates from Laminaria spp are thought to be indigestible by humans. The main storage polysaccharide of these algae is laminarin, a beta-polymer of glucose. The aims of this work were, on the one hand, to compare various methods of extraction of laminarin by partial characterisation of the product obtained and, on the other hand, to study the fate of this polysaccharide and its effects in the gastrointestinal tract in order to determine its potential as a dietary fibre in human nutrition. Among four methods tested to extract laminarin, the best appeared to be a hot HCl-based method. Human digestive enzymes did not hydrolyse laminarin, so this polysaccharide can be considered as a dietary fibre. After ingestion by rats, this polysaccharide was not found in faeces of these animals. It did not increase the intestinal transit and stool output in vivo, but it increased the contractile response of the stomach to acetylcholine in vitro. (C) 2004 Society of Chemical Industry. [less ▲]

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See detailDifferential effect of dietary spermine on alkaline phosphatase activity in jejunum and ileum of unweaned rats
Peulen, Olivier ULg; Gharbi, Myriam ULg; Powroznik, Brigitte et al

in Biochimie (2004), 86(7), 487-493

Spermine is a low molecular weight polyamine involved in the postnatal maturation of the gut. When it is administered orally to suckling rats it induces the maturation of their spleen, liver, pancreas ... [more ▼]

Spermine is a low molecular weight polyamine involved in the postnatal maturation of the gut. When it is administered orally to suckling rats it induces the maturation of their spleen, liver, pancreas, and small intestine. We showed that this polyamine modulates differently the activity of alkaline phosphatase in jejunum and ileum in suckling rat. In 14-day-old rat which had received spermine orally for 3 days, once daily, an increase of alkaline phosphatase activity in the jejunum and a decrease of this activity in the ileum was observed. Alkaline phosphatase was located at the bottom of the villus in the control jejunum and in the whole length of the villus in spermine-treated rats. On the contrary, in ileum of controls, this enzyme was present in the whole length of the villus but disappeared in the spermine-treated animals. An enzyme mass shift was observed in the small intestine after spermine administration. Spermine administration did not change the expression of genes coding for alkaline phosphatase, suggesting a post-transcriptional modification. (C) 2004 Elsevier SAS. All rights reserved. [less ▲]

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See detailAnalysis of PEG 400 and 4000 in urine for gut permeability assessment using solid phase extraction and gel permeation chromatography with refractometric detection
Loret, S.; Nollevaux, G.; Remacle, R. et al

in Journal of Chromatography. B : Analytical Technologies in the Biomedical & Life Sciences (2004), 805(2), 195-202

We developed a treatment of urine samples allowing the analysis of two intestinal permeability markers: polyethylene glycol (PEG) 400 (highly diffusible; basal permeability indicator) and PEG 4000 (poorly ... [more ▼]

We developed a treatment of urine samples allowing the analysis of two intestinal permeability markers: polyethylene glycol (PEG) 400 (highly diffusible; basal permeability indicator) and PEG 4000 (poorly diffusible; indicator of an abnormal increase of permeability) by a unique gel permeation chromatography (GPC) with refractometric detection. Urinary PEG were extracted using a mixed-bed resin composed of C2 and C 18 layers. Permeability mean values determined in 11 human healthy subjects were 24.20 +/- 9.30% and 0.12 +/- 0.08% for, respectively, PEG 400 and 4000. The percentage of the PEG 4000 permeability value to the one of PEG 400 corresponded to an intestinal permeability index (IPI) of 0.52 +/- 0.35 expressing a low diffusion of this poorly permeability marker. (C) 2004 Published by Elsevier B.V. [less ▲]

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See detailSpermine-induced maturation in Wistar rat intestine: A cytokine-dependent mechanism
Peulen, Olivier ULg; Dandrifosse, Guy ULg

in Journal of Pediatric Gastroenterology and Nutrition (2004), 38(5), 524-532

Objectives: Polyamines are of great importance in biologic processes such as cell proliferation and differentiation. The ingestion of spermidine or spermine by suckling rats induces the precocious ... [more ▼]

Objectives: Polyamines are of great importance in biologic processes such as cell proliferation and differentiation. The ingestion of spermidine or spermine by suckling rats induces the precocious maturation of the small intestine. In a previous article, the authors hypothesized that this phenomenon could be mediated by interleukins. This work was performed to examine the role of IL-1, IL-2, and tumor necrosis factor (TNF)-alpha in the spermine-induced maturation of the small intestine. Methods: Wistar suckling rats were treated with spermine, FR167653 (inhibitor of IL-1beta/TNF-alpha production), IL-1beta/TNF-alpha neutralizing antibodies, lipopolysaccharide, or IL-2. Intestinal disaccharidase-specific activities, polyamine content, and IL-2 plasma concentration were analyzed. Comparisons were made with untreated control animals. Results: Spermine-induced maturation of the small intestine was decreased by FR167653 but not by the neutralizing antibodies. Lipopolysaccharide injection induced an increase in disaccharidase-specific activity. IL-2 induced a decrease of the intestinal lactase-specific activity. Spermine administration led to a similar decrease of lactase activity and to an increase of IL-2 plasma concentration. Conclusions: The authors conclude that IL-1beta and TNF-alpha are involved in the spermine effects on maltase- and sucrase- specific activities and suggest that IL-2 is involved in the spermine-induced decrease of lactase activity. (C) 2004 Lippincott Williams Wilkins. [less ▲]

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See detailPolyamines in gut inflammation and allergy
Peulen, Olivier ULg; Deloyer, Patricia; Deville, Christelle ULg et al

in Current Medicinal Chemistry - Anti-Inflammatory & Anti-Allergy Agents (2004), 3

The natural polyamines, named 1,4-diaminobutane, N-aminopropyl-1,4-diaminobutane and N,N'-bisaminopropyl- 1,4-diaminobutane, are also designated respectively as putrescine, spermidine and spermine. They ... [more ▼]

The natural polyamines, named 1,4-diaminobutane, N-aminopropyl-1,4-diaminobutane and N,N'-bisaminopropyl- 1,4-diaminobutane, are also designated respectively as putrescine, spermidine and spermine. They are polycationic compounds found in all eukaryotic cells. As they are deeply involved in cell functions, e.g. cellular growth, their concentration and their equilibrium in the intracellular pool are maintained in very narrow limits by regulatory mechanisms acting in a very fast, sensitive and precise way. These compounds are involved in gut inflammatory processes and in allergy. Indeed, they control the production of inflammatory mediators in several cell lines or tissues. Polyamine metabolism could be considered as a putative target for inflammation, allergy prevention or therapy. [less ▲]

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See detailPotentialisation de l'immunité naturelle du rat nouveau-né par les polyamines exogènes
Powroznik, Brigitte; Gharbi, Myriam ULg; Dandrifosse, Guy ULg et al

Conference (2004)

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See detailPolyamine as innate immunity modulator
Peulen, Olivier ULg; Powroznik, Brigitte; Gharbi, Myriam ULg et al

in Pflügers Archiv : European Journal of Physiology (2004), 449

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