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
Full Text
Peer Reviewed
See detailIn vitro embryo production in goats: slaughterhouse and laparoscopic ovum pick up 2 (LOPU) derived oocytes have different kinetics and requirements regarding maturation 3 media
Souza-Fabjan, JM; Locatelli, Y; Duffard, N et al

in Theriogenology (2014), 81

A total of 3427 goat oocytes were used in this study in order to identify possible 24 differences during in vitro embryo production from slaughterhouse or laparoscopic ovum 25 pick up (LOPU) oocytes. In ... [more ▼]

A total of 3427 goat oocytes were used in this study in order to identify possible 24 differences during in vitro embryo production from slaughterhouse or laparoscopic ovum 25 pick up (LOPU) oocytes. In Experiment 1, one complex, one semi defined and one simplified 26 in vitro maturation (IVM) media were compared using slaughterhouse oocytes. In 27 Experiment 2, we checked the effect of oocyte origin (slaughterhouse or LOPU) on the 28 kinetics of maturation (18 vs. 22 vs. 26 h) when submitted to semi defined or simplified 29 media. In Experiment 3, we determined the differences in embryo development between 30 slaughterhouse and LOPU oocytes when submitted to both media and then to in vitro 31 fertilization (IVF) or parthenogenetic activation (PA). Embryos from all groups were vitrified 32 and their viability evaluated in vitro after thawing. In Experiment 1, no difference (P>0.05) 33 was detected among treatments for maturation rate (MII; 88% on average), cleavage (72%), 34 blastocyst from the initial number of cumulus oocyte complexes (COC; 46%) or from the 35 cleaved ones (63%), hatching rate (69%) and the total number of blastomeres (187). In 36 Experiment 2, there was no difference of MII rate between slaughterhouse oocytes cultured 37 for 18 or 22 h, whereas the MII rate increased significantly (P<0.05) between 18 and 22 h for 38 LOPU oocytes in the simplified medium. Moreover, slaughterhouse oocytes cultured in 39 simplified medium matured significantly faster than LOPU oocytes at 18 and 22 h (P<0.05). 40 In Experiment 3, cleavage rate was significantly greater (P<0.001) in all four groups of 41 embryos produced by PA than IVF. Interestingly, PA reached similar rates for slaughterhouse 42 oocytes cultured in both media, but improved (P<0.05) cleavage rate of LOPU oocytes. 43 Slaughterhouse oocytes had acceptable cleavage rate after IVF (~67%), whereas LOPU 44 oocytes displayed a lower one (~38%), in contrast to cleavage after PA. The percentage of 45 blastocysts in relation to cleaved embryos was not affected by the origin of the oocytes 46 (P>0.05). Therefore, slaughterhouse oocytes developed a greater proportion of blastocysts than LOPU ones, expressed as the percentage of total COC entering to IVM. Vitrified-thawed 48 blastocysts presented similar survival and hatching rates between the oocyte origin, media or 49 method of activation. In conclusion, slaughterhouse and LOPU derived oocytes may have 50 different IVM kinetics and require different IVM-IVF conditions. Although the IVM and IVF 51 systems still need improvements in order to enhance embryo yield, the in vitro development 52 (IVD) step is able to generate good quality embryos from LOPU derived oocytes. [less ▲]

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailIn vitro entomopathogenic activity of Beauveria bassiana against Psoroptes spp. (Acari : Psoroptidae)
Lekimme, Mireille ULg; Mignon, Bernard ULg; Tombeux, S. et al

in Veterinary Parasitology (2006), 139(1-3), 196-202

An indigenous strain (IHEM 18747) of Beauveria bassiana (Balsamo) Vuillemin (Deuteromycetes) was evaluated for its in vitro entomopathogenic activity against the parasitic mite Psoroptes ovis Hering ... [more ▼]

An indigenous strain (IHEM 18747) of Beauveria bassiana (Balsamo) Vuillemin (Deuteromycetes) was evaluated for its in vitro entomopathogenic activity against the parasitic mite Psoroptes ovis Hering (Acari: Psoroptidae) from rabbits. The following aspects were evaluated: (1) effects of conidial concentration on the viability of adult females; (2) influence of the infection on the fertility, and on the hatchability of eggs; (3) and transmission of infection between mites, and from contaminated surface. Adult females immersed into increasing concentrations of conidia (10(4)-10(9) conidia ml(-1)) showed a dose-related susceptibility. At the highest concentration of conidia, LT50 was 1.6 days while LT50 of the controls reached 5.8 days. The fungus was able to sporulate on the body surface and 100% of the mites were covered with mycelium after immersion in solutions containing 10(7)-10(9) conidia ml(-1). One hundred percent of healthy mites exposed to infected cadavers or surfaces acquired the infection (LT50 reached 1.9 and 1.73 days, respectively, versus 6.1 and 5.1 days in controls, respectively). Egg laying was not reduced by the fungal infection but both the hatchability of the eggs and the life span of the emerging larvae were significantly reduced. Eggs directly infected with the fungus did not show reduced hatchability but the life span of the larvae was shortened. It is concluded that B. bassiana has a high entomopathogenic activity against Psoroptes spp. The in vivo use of this biocontrol agent against Psoroptes spp. in rabbit, sheep and cattle deserves further attention. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 64 (12 ULg)
Full Text
See detailIn vitro ESR measurements: powerful tool to study toxic effects on cells
Grammenos, Angeliki ULg; Quoilin, Caroline ULg; Guelluy, Pierre-Henri ULg et al

Poster (2011, October)

Electron spin resonance spectroscopy (ESR) is a highly efficient technique able to access a wide range of information about the unfavourable effects caused by a chemical or a drug. ESR in spin labelling ... [more ▼]

Electron spin resonance spectroscopy (ESR) is a highly efficient technique able to access a wide range of information about the unfavourable effects caused by a chemical or a drug. ESR in spin labelling fits well in with the study of membranes and particularly with the changes in lipid bilayer organisation induced by drug. Our team previously developed a way to quantify the effective lipid bilayer microviscosity of cell membranes and consequently put in evidence the fluidity effect of the propofol. Recently, the importance of lipid raft domains has been shown due to their important role as a platform for signal transduction and protein sorting. We propose to highlight the effect of the Randomly methylated beta cyclodextrin (Rameb) on these domains on membrane model (liposomes) as well as on colon carcinoma cell line (HCT-116). Futhermore, ESR in spin trapping is used in order to identify and quantify the generation of Reactive Oxygen Species (ROS) in cells. An ESR study on human colon carcinoma cell line has highlighted the cytotoxicity of the photosensitizer pyrophephorbide-a methyl ester. Using an intracellular located spin trap (4-pyridyl 1-oxide-N-tert-butylnitrone, POBN), it has been shown that the photoexcitation of the dye is able to generate superoxide anions, hydroxyl radicals and singlet oxygen. Moreover, ESR is one of the most sensitive method for measuring cellular oxygen consumption. Our team has studied the alterations of oxygen respiratory in human tubular renal cells treated with an endotoxin (lipopolysaccharide, LPS). The incubation of HK-2 cells with LPS elicited a decreased in oxygen consumption suggesting a down-regulation of the cells metabolism. [less ▲]

Detailed reference viewed: 40 (12 ULg)
Full Text
Peer Reviewed
See detailIn vitro evaluation of antiplasmodial activity of plant samples used in traditional medicine in Benin
Ganfon, H.; Gbaguidi, F.; Frederich, Michel ULg et al

in Planta Medica (2008), 74(9), 1140-1140

Detailed reference viewed: 11 (1 ULg)
Full Text
Peer Reviewed
See detailIn vitro evaluation of glutathione peroxidase (GPx)-like activity and antioxidant properties of some Ebselen analogues
Mouithys-Mickalad, Ange ULg; Mareque-Faez, Juan; Chistiaens, U. et al

in Redox Report : Communications in Free Radical Research (2004), 9(2), 81-87

Four analogues of Ebselen were synthesized and their glutathione peroxidase activity and antioxidant property evaluated and compared to Ebselen. Among the studied compounds, only diselenide [3] exhibited ... [more ▼]

Four analogues of Ebselen were synthesized and their glutathione peroxidase activity and antioxidant property evaluated and compared to Ebselen. Among the studied compounds, only diselenide [3] exhibited both glutathione peroxidase activity and radical-scavenging capability. Compounds [3] and [4] showed a strong inhibitory effect (53% and 43%, respectively) on the lipid peroxidation of linoleic acid compared to Ebselen and selenide derivatives ([1] and [2]) which were less active (28%, 26% and 18% inhibition, respectively). A concentration-dependent inhibitory effect was also found in the model of the formation of ABTS*+ radical cation: 65% and 89% inhibition for compound [3] at 10(-4) M and 5 x 10(-5) M, respectively, and 68% and 90% for compound [4], compared to 14% and 52% inhibition for Ebselen and the diselenides [1] and [2] (29%, 46% and 45%, 68%, respectively). By EPR spin trapping technique, the following inhibitory profile of the Ebselen analogues was observed towards the formation of thiyl radicals: Ebselen = [3]>[1]>[2]>[4]. Studies with compound [3] are in progress on oxidative stress cell models. [less ▲]

Detailed reference viewed: 20 (2 ULg)
Full Text
Peer Reviewed
See detailAn in vitro evaluation of leakage of two Etch and Rinse and two Self-Etch adhesives after thermocycling
Geerts, Sabine ULg; BOLETTE, Amandine ULg; SEIDEL, Laurence ULg et al

in International Journal of Dentistry [=IJD] (2012)

Our experiment evaluated the microleakage in resin composite restorations bonded to dental tissues with different adhesive systems. 40 class V cavities were prepared on the facial and lingual surfaces of ... [more ▼]

Our experiment evaluated the microleakage in resin composite restorations bonded to dental tissues with different adhesive systems. 40 class V cavities were prepared on the facial and lingual surfaces of each tooth with coronal margins in enamel and apical margins in cementum (root dentin). The teeth were restored with Z100 resin composite bonded with different adhesive systems: Scotchbond! Multipurpose (SBMP) a 3-step Etch and Rinse adhesive, Adper! Scotchbond! 1 XT (SB1) a 2-step Etch and Rinse adhesive, AdheSE® One (ADSE-1) a 1-step Self-Etch adhesive and AdheSE® (ADSE) a 2-step Self-Etch adhesive. Teeth were thermocycled and immersed in 50 % silver nitrate solution. When both interfaces were considered, SBMP has exhibited significantly less microleakage than other adhesive systems (respectively for SB1, ADSE-1 and ADSE, p = 0.0007, p < 0.0001 and p < 0.0001). When enamel and dentin interfaces were evaluated separately: 1) for the Self-Etch adhesives, microleakage was found greater at enamel than at dentin interfaces (for ADSE, p = 0.024 and for ADSE-1, p < 0.0001); 2) for the Etch and Rinse adhesive systems, there was no significant difference between enamel and dentin interfaces; 3) SBMP was found significantly better than other adhesives both at enamel and dentin interfaces. In our experiment Etch and Rinse adhesives remain better than Self-Etch adhesives at enamel interface. In addition, there was no statistical difference between 1-step (ADSE-1) and 2-step (ADSE) Self-Etch adhesives. [less ▲]

Detailed reference viewed: 25 (6 ULg)
Full Text
Peer Reviewed
See detailIn vitro evaluation of lipid matrices for the development of a sustained-release sulfamethazine bolus for lambs
Evrard, Brigitte ULg; Delattre, Luc ULg

in Drug Development & Industrial Pharmacy (1996), 22(2), 111-118

The aim of this study is the development of a high-density bolus to be given to lambs in order to release sulfamethazine during 4 days after a single oral administration. The suitability of 12 lipid ... [more ▼]

The aim of this study is the development of a high-density bolus to be given to lambs in order to release sulfamethazine during 4 days after a single oral administration. The suitability of 12 lipid matrix formulations was assessed in order to maintain the integrity of the tablet even after complete dissolution of the active substance. The influence of both nature and concentration of the lipid excipient on the in vitro release of sulfamethazine was investigated. The influences of the granulation method and of the compression force were assessed on a formulation containing Cutina® HR as a binding and sustained-release agent. Finally, stability tests showed that the in vitro release characteristics remain unchanged during storage. [less ▲]

Detailed reference viewed: 18 (0 ULg)
Full Text
Peer Reviewed
See detailIn vitro evaluation of the fermentation characteristics in the pig intestines of hulless barleys differing in β-glucan content
Jha, Rajesh; Bindelle, Jérôme ULg; Rossnagel, Brian et al

in Journal of Animal Science (2009), 87(E-Suppl. 3), 103

Non-starch polysaccharides (NSP) in isolated form, especially β-glucans, are reported to have prebiotic effects in pigs. However, little information is available on the possible functional properties of ... [more ▼]

Non-starch polysaccharides (NSP) in isolated form, especially β-glucans, are reported to have prebiotic effects in pigs. However, little information is available on the possible functional properties of these NSP when the latter are still present in the fibrous matrix of whole cereals. Hulless barleys (HB) are good sources of β-glucans and the content is quite variable among varieties. In order to evaluate the potential of HB as functional feeds, an in vitro experiment was carried out to study the fermentation characteristics of 6 HB varieties varying in their β-glucan contents (36-99 g/kg DM) in comparison to 3 hulled barleys and 5 oats. After a pepsin-pancreatin hydrolysis, the ingredients were incubated in a buffer solution containing minerals and pig feces as inoculum. The accumulated gas production, proportional to the amount of fiber fermented, was measured for 48 h and modeled. Short-chain fatty acid (SCFA) and ammonia concentration were measured in the fermented solutions. A cereal type effect (P < 0.05) was observed on the fermentation kinetics parameters. Rates of degradation and total gas productions were higher in HB than in oats (P < 0.05) but no difference was observed between HB varieties. On the contrary, differences were found between HB for lag time and rate of degradation. The production of SCFA was also higher with HB (6.1 mMol/g DM incubated; P < 0.05) than with hulled barleys and oats (4.9 and 2.9 mMol/g DM incubated respectively). In contrast, oats generated higher ammonia (P <0.05) production (1.4 mMol/g DM incubated, on average) than barley (1.0 mMol/g). In conclusion, HB are better fermented in vitro, produce more beneficial (SCFA) and less harmful (ammonia) metabolites and have a better potential than other cereal species to modulate gut microbiota and improve gut health. [less ▲]

Detailed reference viewed: 19 (4 ULg)
Full Text
Peer Reviewed
See detailIn vitro evaluation of the fermentation characteristics of the carbohydrate fractions of hulless barley and other cereals in the gastrointestinal tract of pigs
Jha, Rajesh; Bindelle, Jérôme ULg; Rossnagel, Brian et al

in Animal Feed Science & Technology (2011), 163

An in vitro model was used to study the fermentation characteristics of carbohydrate fractions of hulless barley (hB), in comparison to hulled barley (HB), hulled oat and oat groats (OG) in the pig ... [more ▼]

An in vitro model was used to study the fermentation characteristics of carbohydrate fractions of hulless barley (hB), in comparison to hulled barley (HB), hulled oat and oat groats (OG) in the pig intestine. For this purpose, 6 hulless barley cultivars (hB), varying in β-glucan content (36-99 g/kg DM), were compared to 3 HB cultivars, 2 oat groat samples (OG), 3 oat varieties and a reference sample of wheat. The residue of a pepsin-pancreatin hydrolysis was incubated in a buffered mineral solution inoculated with pig faeces. Gas production, proportional to the amount of fermented carbohydrates, was measured for 48 h and kinetics modelled. The fermented solution was subsequently analyzed for microbial production of short-chain fatty acids (SCFA) and ammonia. In vitro dry matter degradability varied according to ingredient (P<0.001). Higher values were observed for OG, ranging from 0.88 to 0.99 as compared to oat, hB and HB, for which degradability ranged from 0.63 to 0.73, 0.68 to 0.80 and 0.69 to 0.71, respectively. A “cereal type” effect (P<0.05) was observed on fermentation kinetics parameters. Total gas production was higher (P<0.05) with hB (224 ml/g DM incubated) than with HB and oat (188 and 55 ml/g DM incubated, respectively). No difference was observed between hB cultivars (P>0.05) for total gas production but differences (P<0.001) were found for lag time and the fractional rate of degradation. Hulless barley cultivar CDC Fibar (waxy starch) and CDC McGwire (normal starch) started to ferment sooner (lag time of 0.7 and 0.9 h, respectively) than SH99250 (high amylose starch; 1.7 h). The fractional rate of degradation was similar in both hB and OG (0.15/h on average), which was higher than that of HB (0.12/h). The production of SCFA was also higher (P<0.05) with hB (6.1 mmol/g DM incubated, on average) than with HB and oat (4.9 and 2.9 mmol/g DM incubated, respectively). Similar trends were found for SCFA production expressed per g fermented carbohydrates, with higher butyrate and lower acetate ratio. In contrast, oat fermentation generated higher (P<0.05) ammonia concentration (1.4 mmol/g DM incubated, on average) than hB (1.0 mmol/g DM incubated). In summary, hulless barleys, irrespective of cultivar type had higher in vitro fermentability and produced more SCFA and less ammonia than hulled barley and oat. Thus, hulless barleys have a better potential to be used in pig nutrition to manipulate the fermentation activity in the intestine of pigs. [less ▲]

Detailed reference viewed: 39 (9 ULg)
See detailIn vitro expression of RC2-labeled antigens as radial glial cells markers in cultures derived from mouse embryonic brain
Leprince, P; Chanas-Sacré, G; Lewin, M et al

Poster (1996)

Detailed reference viewed: 7 (0 ULg)
See detailIn vitro fibre fermentation characteristics of specialty ingredients with varying NSP levels
Jha, Rajesh; Bindelle, Jérôme ULg; Rossnagel, Brian et al

Poster (2009)

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailIn vitro fibre fermentation of feed ingredients with varying fermentable carbohydrate and protein levels and protein synthesis by colonic bacteria isolated from pigs
Jha, Rajesh; Bindelle, Jérôme ULg; Van Kessel, Andrew et al

in Animal Feed Science & Technology (2011), 165

An in vitro experiment was carried out using the gas technique to study the fermentation characteristics of different feed ingredients differing in their fermentable carbohydrate and protein composition ... [more ▼]

An in vitro experiment was carried out using the gas technique to study the fermentation characteristics of different feed ingredients differing in their fermentable carbohydrate and protein composition by colonic bacteria isolated from pigs. The effect on in vitro bacterial protein synthesis was also evaluated. The ingredients used were wheat bran (WB), wood cellulose (Solka-floc®, SF), peas, pea hulls (PH), pea inner fibre (PIF), sugar beet pulp (SBP), flax seed meal (FSM) and corn distillers dried grains with solubles (DDGS). The samples were pre-treated with pepsin and pancreatin and the hydrolyzed substrates were then incubated with pig faeces in a buffered mineral solution. The nitrogen source in the buffer solution (NH4HCO3) was replaced by an equimolar quantity of 15N-labeled NH4Cl, used for the determination of the rate of bacterial protein synthesis. Gas production, proportional to the amount of fermented carbohydrate, was recorded for 48 h and modelled. The fermented product was subjected to short-chain fatty acids (SCFA) analysis. The source of fibre affected the in vitro dry matter degradability (IVDMD), the fermentation kinetics and the gas production profile (P<0.05). The highest (P<0.001) IVDMD values were observed for peas (0.80) and FSM (0.70), whereas SF was essentially undegraded (0.06). The fractional rate of degradation appeared to be lower (P<0.001) for WB and DDGS (0.07 and 0.05 h, respectively) and highest for SBP (0.20 h). Peas started to ferment rapidly (lag time 1.3 h). Half gas production (T/2) was achieved sooner for PIF (8.4 h) and was the longest for DDGS (19.8 h). The total gas production was the highest for PH, followed by SF, PIF and peas (276, 266, 264 and 253 ml/g DM incubated, respectively) and the lowest for FSM and WB (130 and 124 ml/g DM incubated, respectively). There was no difference (P>0.05) in SCFA production after the fermentation of SF, P, PH, PIF and SBP (ranging from 3.8 to 4.5 mmol/g DM incubated) while WB and FSM yielded lowest (P<0.05) SCFA. The bacterial nitrogen incorporation (BNI), both at T/2 and after 48 h of fermentation was the highest (P<0.001) for PIF (18.5 and 15.6 mg/g DM incubated, respectively) and the lowest for DDGS and WB. In conclusion, peas and pea fibres had higher rates of fermentability, produced more SCFA and had high bacterial protein synthesis capacity. They thus have the potential to be included in pig diets as a source of fermentable fibre to modulate the gut environment and reduce nitrogen excretion. [less ▲]

Detailed reference viewed: 69 (18 ULg)
Full Text
Peer Reviewed
See detailIn vitro hemocompatibility of nanocarriers tailored for biopharmaceutical drugs.
Sevrin, Chantal ULg; Cerda Cristerna, Bernardino Isaac ULg; Lombart, François ULg et al

Poster (2012, May 06)

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed ... [more ▼]

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed the large surface they are able to expose to the biological environment promotes their interaction with various biochemicals, in particular proteins which can after adsorption elicit the activation of biological cascades either responsible from NP clearance or/and harmful body reaction (inflammatory / coagulation). In the frame of the European Integrated Project : “Nanobiopharmaceutics”, we have the opportunity to compare the hemoreactivity of about 145 different NP samples differing in core and surface chemistry and classified according to their expected difference in hydrophobicity based on the nature of their core materials. According to this classification, PLGA nanoparticles, polyglycidol-polyethyethylene oxide nanoparticles, polyglycidol thyolated or polyacrylamide nanogels, and polyelectrolyte complexes either based on polyamidoamine or poly(N,N-dimethylamino- 2-ethylmethacrylate) have been evaluated within a concentration ranging from 0.3 to 1000 μg/mL. These in vitro tests have been realized for screening purpose adopting normal human bloods and according to Iso 10993. As a summary of this extensive study, our results clearly highlight that most of the polymeric nanoparticles evaluated give rise to some alterations of the blood components. In particular the platelets, intrinsic pathway of coagulation and complement activation are the most reactive biological parameters in the presence of these nanostuctures. Although not strictly related to the surface chemistry our classification has also allowed us to derive some clear correlations between nanomaterial properties and their hemoreactivity. Within the class of polyelectrolyte electrolyte complexes, the modifications brought in the surface chemistry has drastically improved their hemoreactivity [less ▲]

Detailed reference viewed: 30 (2 ULg)
Full Text
Peer Reviewed
See detailIn vitro identification of targeting ligands of human M cells by phage display
Fievez, V.; Plapied, L.; Plaideau, C. et al

in International Journal of Pharmaceutics (2010), 394(1-2), 35-42

To improve transport of vaccine-loaded nanoparticles, the phage display technology was used to identify novel lead peptides targeting human M cells. Using an in vitro model of the human follicle ... [more ▼]

To improve transport of vaccine-loaded nanoparticles, the phage display technology was used to identify novel lead peptides targeting human M cells. Using an in vitro model of the human follicle-associated epithelium (FAE) which contains both Caco-2 and M cells, a T7 phage display library was screened for its ability either to bind the apical cell surface of or to undergo transcytosis across Caco-2 cells or FAE. The selection for transcytosis across both enterocytes and FAE identified three different peptide sequences (CTGKSC, PAVLG and LRVG) with high frequency. CTGKSC and LRVG sequences enhanced phage transport across M-like cells. When polymeric nanoparticles were grafted with the sequences CTGKSC and LRVG, their transport by FAE was significantly enhanced. These peptides could therefore be used to enhance the transport of vaccine-loaded nanoparticles across the intestinal mucosal barrier. [less ▲]

Detailed reference viewed: 17 (3 ULg)
Peer Reviewed
See detailIn vitro induced imbalance between stromelysin and TIMP-1 production by human chondrocytes
Henrotin, Yves ULg; Labasse, A; Crielaard, Jean-Michel ULg et al

in Osteoarthritis and Cartilage (1999), 7(SA), 33

Detailed reference viewed: 3 (1 ULg)
Full Text
Peer Reviewed
See detailThe in vitro influences of neurotensin on the motility characteristics of human U373 glioblastoma cells
Servotte, S.; Camby, I.; Debeir, O. et al

in Neuropathology & Applied Neurobiology (2006), 32(6), 575-584

Astrocytic tumours are associated with dismal prognoses due to their pronounced ability to diffusely invade the brain parenchyma. Various neuropeptides, including gastrin, are able to modulate tumour ... [more ▼]

Astrocytic tumours are associated with dismal prognoses due to their pronounced ability to diffusely invade the brain parenchyma. Various neuropeptides, including gastrin, are able to modulate tumour astrocyte migration. While neurotensin has been shown to influence the proliferation of glioma cells and the migratory ability of a large set of other cell types, its role in glioma cell migration has never been investigated. Neurotensin-induced modifications to the motility features of human U373 glioblastoma cells therefore constitute the topic of the present study. We evidenced that three subtypes of neurotensin receptors (NTR1, NTR2 and NTR3) are expressed in U373 glioblastoma cells, at least as far as their mRNAs are concerned. Treating U373 tumour cells with 10 nM neurotensin markedly modified the morphological patterns of these cells and also profoundly altered the organization of their actin cytoskeletons. Pull-down assays revealed that neurotensin induced the activation in U373 cells of both Rac1 and Cdc42 but not RhoA. Scratch wound assays evidenced that neurotensin (0.1 and 10 nM) very significantly inhibited wound colonization by U373 cells cultured in the absence of serum. In addition, quantitative phase-contrast videomicroscopy analyses showed that neurotensin decreases the motility levels of U373 glioblastoma cells when these cells are cultured on plastic. In sharp contrast, neurotensin stimulates the motility of U373 cells when they are cultured on laminin, which is a pro-adhesive extracellular matrix component ubiquitously secreted by glioma cells. Our data thus strongly suggest that, in addition to gastrin, neurotensin is a neuropeptide capable of modulating tumour astrocyte migration into the brain parenchyma. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailIn Vitro Inhibitory Effect of SR 27417, a Potent Platelet-Activating Factor (PAF) Receptor Antagonist, on the PAF-Induced Bovine Platelet Aggregation
Bastos da Silva, Miriam; Delaunois, Annie ULg; Gustin, Pascal ULg et al

in Veterinary Research (2000), 31(2, Mar-Apr), 267-672

The in vitro inhibitory effect of SR 27417, an antagonist of the platelet-activating factor (PAF) receptor, on PAF-induced platelet aggregation was studied in blood collected from seven healthy Friesien ... [more ▼]

The in vitro inhibitory effect of SR 27417, an antagonist of the platelet-activating factor (PAF) receptor, on PAF-induced platelet aggregation was studied in blood collected from seven healthy Friesien calves. Inhibitory effects of SR 27417 were determined at thirteen different concentrations (0.1-400 nM) by using the dose-response curves of PAF on calf platelet aggregation. In the presence of SR 27417, the maximal slopes of aggregation (%/min) induced by low and high concentrations of PAF were significantly different from the control values obtained without an antagonist at p < or = 0.05 and p < or = 0.01 respectively. In vitro PAF-induced calf platelet aggregation was dose-dependently inhibited by SR 27417. The drug inhibited PAF-induced platelet aggregation in a competitive reversible manner (pA2 = 10.46 +/- 2.36 mol x L(-1)). In conclusion, the results of our study showed that addition of SR 27417 to bovine platelet in vitro inhibits PAF-induced platelet aggregation. [less ▲]

Detailed reference viewed: 74 (3 ULg)