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See detailEffects of Polychlorinated Biphenyls on Liver Ultrastructure, Hepatic Monooxygenases, and Reproductive Success in the Barbel
Hugla, J. L.; Thomé, Jean-Pierre ULg

in Ecotoxicology & Environmental Safety (1999), 42(3), 265-73

Polychlorinated biphenyls (PCBs) are organochlorinated micropollutants ubiquitously distributed in the environment. They are known to be strong inducers of hepatic monooxygenases in fish. This can ... [more ▼]

Polychlorinated biphenyls (PCBs) are organochlorinated micropollutants ubiquitously distributed in the environment. They are known to be strong inducers of hepatic monooxygenases in fish. This can adversely affect reproduction by increasing steroid metabolism. In this work, adult barbels were contaminated with food containing Aroclor 1260, a commercial PCB mixture from Monsanto, at environmentally relevant concentrations. A significant increase in cytochrome P450 was observed, and two particularly sensitive enzymes, ethoxyresorufin o-deethylase (EROD) and ethoxycoumarin o-deethylase (ECOD), were strongly induced. Electron microscopy revealed alterations in liver ultrastructure in contaminated fish, principally an increase in the number of cisternae of the rough endoplasmic reticulum, drastic glycogen depletion, dissolution of mitochondrial contents, and appearance of myelin figures. Contamination was also studied in relation to reproductive success in a hatchery. Contaminated males displayed no alteration in milt quality, but PCBs did alter female reproductive parameters. Total mortality of eggs and larvae increased significantly with the level of PCBs in the eggs. The most highly contaminated fish did not even spawn. All the adverse effects recorded here tended to be reversible when the intoxication ended, sometimes after only a 1-year detoxication period. [less ▲]

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See detailEffects of Polychlorinated Biphenyls on Thyroid Hormone Physiology and Metabolism of European sea bass (Dicentrarchus labrax)
Schnitzler, Joseph ULg; Klaren, Peter; Celis, Niko et al

Conference (2010)

Studies in the laboratory have shown that a number of synthetic and natural chemicals can interfere with the endocrine system in fish. Among them, organic compounds such as pesticides and ... [more ▼]

Studies in the laboratory have shown that a number of synthetic and natural chemicals can interfere with the endocrine system in fish. Among them, organic compounds such as pesticides and polychlorobiphenyls (PCBs) are well described endocrine disrupters. Of particular interest are effects on thyroid function, but data on effects of PCB exposure on these hormones and related metabolism has been lacking. We propose here a thorough approach to assess effects of these compounds on the thyroid function of European sea bass (Dicentrarchus labrax). An experimental exposure of sea bass to commercial PCB mixtures has been designed to understand underlying toxicity mechanisms and effects on the thyroid system. After 120 days of exposure, muscular thyroid hormone concentrations and the main metabolic pathways for thyroid hormones (deiodination, glucuronidation and sulfatation) were assessed. Exposure to environmental relevant doses of PCB (from 0.3 to 0.9 ppm [7 ICES PCB]). alters hepatic T4 outer ring deiodinase and T4 sulfatation whereas T4 glucuronidation was not affected. Owing to the extensive autoregulatory feedback at both central and peripheral levels, the thyroid hormone concentrations were preserved despite the PCB induced changes in thyroid hormone dynamics. At 10 times higher concentrations (10 ppm [7 ICES PCB]). an important depression of muscular T3 and T4 levels could be observed which are apparently caused by other mechanisms than metabolic pathways. Further analysis is required to evaluate thyroid gland function and secretion. These results support the observations made in our field study in wild sea bass (Dicentrarchus labrax) from coastal regions near several important European rivers mouths. [less ▲]

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See detailEffects of polychlorobiphenyls, polybromodiphenylethers, organochlorine pesticides and their metabolites on vitamin A status in lactating grey seals
Vanden Berghe, M; Weijs, L; Habran, Sarah ULg et al

in Environmental Research (2013), 120(18-26),

Polychlorobiphenyls (PCBs), polybromodiphenylethers (PBDEs) and organochlorine pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB) are considered to be endocrine ... [more ▼]

Polychlorobiphenyls (PCBs), polybromodiphenylethers (PBDEs) and organochlorine pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB) are considered to be endocrine disruptors in laboratory and wild animals. This study investigated whether these compounds and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) may affect the homeostasis of vitamin A, a dietary hormone, in the blubber and serum of twenty lactating grey seals sampled at early and late lactation on the Isle of May, Scotland. The effect of naturally produced compounds such as the methoxylated (MeO)-PBDEs was also examined. Vitamin A levels in inner blubber (37 ± 9 µg/g wet weight (ww) and 92 ± 32 µg/g ww at early and late lactation, respectively) and serum (408 ± 143 ng/ml and 390 ± 98 ng/ml at early and late lactation, respectively) appeared to be positively related to ΣPCBs, ΣPBDEs and several individual PCB and PBDE congeners in inner blubber and serum. These findings may suggest an enhanced mobilisation of hepatic retinoid stores and a redistribution in the blubber, a storage site for vitamin A in marine mammals, before the onset of lactation. We also reported that serum concentrations of ΣHO-PCBs and 4-OH-CB107 tended to increase circulating vitamin A levels. Although the direction of the relationships may sometimes differ from those reported in the literature, our results are in agreement with previous findings highlighting a disruption of vitamin A homeostasis in the blubber and bloodstream following exposure to environmental pollutants. Previous studies have shown an interesting parallelism between the mobilisation and transfer of vitamin A and those of PCBs in lactating grey seals, contrary to other lipophilic molecules such as vitamin E (Debier et al. 2004; Vanden Berghe et al. 2010). The fact that vitamin A and PCBs appeared to share common mechanisms during this particular physiological state in grey seals (lactation coupled to a total fasting) may also play a role in the different relationships observed between vitamin A and lipophilic pollutants. [less ▲]

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See detailEffects of polycyclic aromatic hydrocarbons on hepatic steroid metabolism
Brasseur, Catherine ULg; Muller, Marc ULg; Widart, Stéphane et al

in Journal of Biotechnology (2007), 131(2, Suppl. S), 73

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See detailEffects of porosity on emergent synthetic spectra of massive stars in the X-ray domain
Hervé, Anthony ULg; Rauw, Grégor ULg

in Bulletin de la Societe Royale des Sciences de Liege (2011), 80

Massive stars possess powerful stellar winds. Studies over the last decade, including the analyses of X-ray emission-line profiles, revealed the importance of wind fragmentation and clumping and led to a ... [more ▼]

Massive stars possess powerful stellar winds. Studies over the last decade, including the analyses of X-ray emission-line profiles, revealed the importance of wind fragmentation and clumping and led to a downwards revision of the mass-loss rates. We present the first results of our code that allows to compare two models of wind fragmentation, and their consequences on the emergent X-ray spectra of massive stars. [less ▲]

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See detailEffects of procaine and d-tubocurarine on the activity of membrane bound acetylcholinesterase
Foidart, Jean-Michel ULg; Gridelet, J.

in Biochemical Pharmacology (1974), 23

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See detailEffects of Processing on the Compositions and Physicochemical Properties of Fibre Concentrate from Cooked Fruit Pomaces
Rabetafika, Holy-Nadia ULg; Bchir, Brahim ULg; Aguedo, Mario ULg et al

in Food and Bioprocess Technology (2013)

This study examined the influence of applied tech- nologies namely desugaring, grinding, and bleaching on the compositions (cellulose, hemicelluloses, lignins, and pectins), physicochemical properties ... [more ▼]

This study examined the influence of applied tech- nologies namely desugaring, grinding, and bleaching on the compositions (cellulose, hemicelluloses, lignins, and pectins), physicochemical properties (water-holding capacity (WHC), swelling capacity (SWC), oil-holding capacity (OHC)) and the colour of dietary fibre (DF) during the production of fibre concentrates from unusual cooked apple and pear pomaces. Thermogravimetric analysis (TGA) and optical microscopy were also performed to monitor process-induced modifica- tion. All the processing conditions affected the compositions and physicochemical properties of DF. The bleaching treat- ment induced the greatest changes on DF producing yellow cellulose-rich fibre concentrates with improved WHC from 3.2 to 10.0 g/g and improved SWC from 4.0 to 8.8 ml/g. Otherwise, reduction of the particle size influenced hydration properties and colours of DF. WHC and SWC tended to increase with the particle size whereas smaller granulometric size increased the lightness of fibres. Desugaring increased the DF content in both pomaces by 1.2-fold with slight modifica- tion of apple insoluble dietary fibre ratio. Fibre concentrates had improved WHC and SWC up to 1.4-fold. All processes had no significant effect (p < 0.05) on OHC of DF except with ultrafine apple fibre concentrates. Results showed that pro- cessing had overall positive effects on DF contents and hy- dration properties of pomaces from cooked fruits. Bleached fibre concentrates from apple pomace had the highest WHC (10.0 g/g) whereas that of pear had the highest fibre content (89.9 %). Fibres from cooked fruit pomaces may therefore be used as textural ingredients or functional foods. [less ▲]

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See detailEffects of prodelphinidins isolated from Ribes nigrum leaves on chondrocyte metabolism and COX activity
Angenot, Luc ULg; Garbacki, Nancy ULg; Damas, Jacques et al

Poster (2002, October 29)

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See detailEffects of prodelphinidins isolated from Ribes nigrum on chondrocyte metabolism and COX activity
Garbacki, Nancy ULg; Angenot, Luc ULg; Bassleer, C. et al

in Naunyn-Schmiedeberg's Archives of Pharmacology (2002), 365(6), 434-441

Articular diseases. such as osteoarthritis, is the clinical expression of the loss of cartilage function. COX inhibitors are widely used in the treatment of such pathologies for their beneficial effects ... [more ▼]

Articular diseases. such as osteoarthritis, is the clinical expression of the loss of cartilage function. COX inhibitors are widely used in the treatment of such pathologies for their beneficial effects on inflammation but often produce a negative activity on cartilage synthesis. In this study, we determined the effect of different prodelphinidins, the major compounds isolated from Ribes nigrum leaves, on the proteoglycans (PGs), type II collagen (coll. II) and prostaglandin E-2 (PGE(2)) production by differentiated human chondrocytes cultivated in long term (12 days) and in clusters as well as their inhibition potential on COX-1 and COX-2 in vitro. Gallocatechin trimer (GC-GC-GC) showed the higher stimulation of PGs and coll. II production (1 mug ml(-1)) and the synthesis of PGE(2) was significantly reduced by gallocatechin dimer (GC-GC), gallocatechin-epigallocatechin (GC-EGC) and GC-GC-GC at 10 and 100 mug ml(-1). The inhibition of PGE(2) synthesis was confirmed by the in vitro test on purified COX enzymes, showing the selectivity of prodelphinidins on COX-2. However, the prodelphinidins had no effects on COX activity in the whole blood assay. Our studies suggest that the prodelphinidins fractions from R. nigrum may be useful as an additive agent in the prevention of osteoarthritis. [less ▲]

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See detailEffects of Proglumide and Enprostil on Omeprazole-Induced Fundic Endocrine Cell Hyperplasia in Rats
Delwaide, Jean ULg; Latour, Pascale ULg; Gast, Pierrette ULg et al

in Gastroentérologie Clinique et Biologique (1993), 17(11), 792-6

Long-term treatment with omeprazole induces hyperplasia of enterochromaffin-like cells, closely related to hypergastrinemia. We studied whether proglumide, an antagonist of gastrin/CCK receptor, and ... [more ▼]

Long-term treatment with omeprazole induces hyperplasia of enterochromaffin-like cells, closely related to hypergastrinemia. We studied whether proglumide, an antagonist of gastrin/CCK receptor, and enprostil, a synthetic prostaglandin E2 derivative, might inhibit this hyperplasia. Six groups of 8 rats were treated for 10 weeks: a) untreated controls; b) omeprazole 10 mumol/kg; c) proglumide 500 mg/kg; d) enprostil 30 micrograms/kg; e) association of omeprazole and proglumide; f) association of omeprazole and enprostil. Serum gastrin levels were measured at different times during treatment. After sacrifice, fundic argyrophil cells were assessed by Grimelius' staining. Serum gastrin levels and argyrophil cell density were not modified in proglumide- and enprostil-treated groups, as compared with controls. Omeprazole increased significantly these two parameters. When given with omeprazole, proglumide decreased significantly serum gastrin levels and argyrophil cell density, as compared to omeprazole alone, while enprostil did not modify significantly these two parameters. These results indicate that proglumide, but not enprostil, can counteract the omeprazole-induced argyrophil cell hyperplasia in rats. [less ▲]

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See detailEffects of propofol on endothelial cells subjected to a peroxynitrite donor (SIN-1).
Mathy, Marianne ULg; Mouithys-Mickalad, Ange ULg; Kohnen, S. et al

in Anaesthesia (2000), 55(11), 1066-71

We investigated the effect of propofol on endothelial cells subjected to the peroxynitrite (ONOO-) donor 3-morpholino sydnonimine (SIN-1). Cells were incubated overnight with 0.5, 1.0 or 2.0 mM SIN-1 ... [more ▼]

We investigated the effect of propofol on endothelial cells subjected to the peroxynitrite (ONOO-) donor 3-morpholino sydnonimine (SIN-1). Cells were incubated overnight with 0.5, 1.0 or 2.0 mM SIN-1, with or without 10-3 M propofol (Diprivan). Cytotoxicity, assessed by measuring the release of pre-incorporated 51Cr, increased when the concentration of SIN-1 increased, and was significantly decreased by 10-3 M propofol (90%, 78% and 28% of protection against 0.5, 1.0 and 2.0 mM SIN-1, respectively). Cell protection against 1 mM SIN-1 was tested with 0.03-1.0 mM propofol and this was compared to tyrosine, a target molecule for peroxynitrite. Propofol protected cells in a dose-dependent manner (r = 0.98; p < 0.001) and was as effective as tyrosine. Finally, using high-performance liquid chromatography, we demonstrated that propofol reacted with ONOO- more rapidly than did tyrosine, inhibiting nitrotyrosine formation. In the absence of propofol, 3.5 mM ONOO- with 1 mM tyrosine yielded 39.6% nitrotyrosine, but nitrotyrosine was not produced when 5 mM propofol was added. We conclude that propofol protects endothelial cells against the toxicity of ONOO-. The anti-oxidant properties of propofol can be partially attributed to its scavenging effect on peroxynitrite, a property that might be relevant in pathological situations involving a significant contribution of peroxynitrite to tissue damage. [less ▲]

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See detailEffects of pulsatile delivery of insulin and glucagon in humans.
Paolisso, G.; Scheen, André ULg; Albert, Adelin ULg et al

in American Journal of Physiology (1989), 257(5 Pt 1), 686-96

The purpose of the present study was to investigate the respective effects of continuous intravenous delivery of both insulin and glucagon compared with those of pulsatile insulin (and continuous glucagon ... [more ▼]

The purpose of the present study was to investigate the respective effects of continuous intravenous delivery of both insulin and glucagon compared with those of pulsatile insulin (and continuous glucagon), pulsatile glucagon (and continuous insulin) and both hormones administered in a pulsatile manner (but out of phase) on various parameters of glucose turnover. The study was performed on six healthy male volunteers submitted to a 325-min glucose-controlled glucose intravenous infusion using the Biostator. The endogenous secretion of pancreatic hormones was inhibited by somatostatin (2 micrograms/min). Four combinations of continuous and pulsatile infusions of insulin and glucagon were performed on different days and in random order. The amounts of hormone infused were identical in all instances and were 0.2 mU.kg-1.min-1 (continuous insulin), 67 ng/min (continuous glucagon), 1.3 mU.kg-1.min-1 and 435 ng/min with a switching on-off length of 2-11 min (for intermittent insulin and glucagon delivery, respectively). In the case of pulsatile administration of both hormones, the pulses of insulin and glucagon were given out of phase with a 6-min interval. Blood glucose levels and glucose infusion rate were monitored continuously by the Biostator, and classic methodology using a D-[3-3H]glucose infusion allowed to study glucose turnover. When compared with pulsatile insulin and continuous glucagon, pulsatile glucagon and continuous insulin were characterized by a significantly higher endogenous (hepatic) glucose production. When both insulin and glucagon were delivered in a pulsatile manner, the effect of pulsatile glucagon was predominant, maintaining a high endogenous glucose production. Under no circumstance was an effect on glucose utilization or clearance detected. This study demonstrates that pulsatile delivery of insulin or glucagon in humans has greater effects in modulating endogenous glucose production than continuous infusion. Furthermore, when both insulin and glucagon are delivered intermittently and out of phase, the stimulatory effect of glucagon on endogenous glucose production prevails over the inhibitory effect of insulin. [less ▲]

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See detailThe effects of purified Z- and E-guggulsterones from guggul-gum extract on human preadipocytes proliferation and differentiation through the study of gene expression of adipose markers.
Hanon, Emilien ULg; Keophiphath, Mayoura; Jacquemond-Collet, Ingrid et al

Poster (2009)

The rising prevalence of obesity within both industrialized and emerging societies is a major public health problem. Indeed obesity is a usual risk factor in the development of metabolic and ... [more ▼]

The rising prevalence of obesity within both industrialized and emerging societies is a major public health problem. Indeed obesity is a usual risk factor in the development of metabolic and cardiovascular diseases which nowadays rank among the highest causes of premature death. Therefore, modulating fat mass expansion represents a worldwide challenge. In this context, adipocyte differentiation, which corresponds to the cellular transition of a fibroblastic cell (the preadipocyte) to a highly specialized cell accumulating triglycerides (the adipocyte), is a decisive process in the expansion of adipose tissue during life span and consequently, in the development of obesity. Adipogenesis markers such as PPARg2, C/EBPa, lipoprotein lipase (LPL), perilipin (PLIN) and the adipokines (leptin and adinopectin) are known to be expressed throughout the different stages of adipocyte differentiation. Guggulsterones are the principal bioactive steroidal components found in the oleoresin (guggul gum) collected from the indian guggul tree, Commiphora mukul (Hook, ex Stocks) Engl. The objective of this study was to investigate the effects of the two purified diastereoisomeric forms of guggulsterones (Z- and E-) on the human preadipocytes proliferation and differentiation. [less ▲]

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See detailEffects of raloxifene on bone mineral density and biochemical markers of bone turnover in postmenopausal women with osteoporosis : 4-year results from the MORE trial
Delmas, PD; Ensrud, KE; Harper, K et al

in Journal of Bone and Mineral Research (2000), 15(S1), 556

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See detailThe effects of raloxifene on incident vertebral fractures in postmenopausal women with osteoporosis : 4-year results from the MORE trial
Eastell, R; Adachi, J; Harper, K et al

in Journal of Bone and Mineral Research (2000), 15(S1), 229

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See detailThe effects of raw and processed Mucuna priurens seed based diets on the growth parameters and meat characteristics of Benin local Guinea fowl (Meleagris numida, L)
Dahouda, M.; Toleba, S. S.; Youssao, A. K. I. et al

in International Journal of Poultry Sciences (2009), 8(9), 882-889

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See detailEffects of reducing sugar concentration on in vitro tuber formation and sprouting in yam (Dioscorea cayenensis-D. rotundata complex).
Ondo Ovono, Paul ULg; Kevers, Claire ULg; Dommes, Jacques ULg

in Plant Cell, Tissue & Organ Culture (2009), 99(1), 55-59

The effects of reducing sucrose level on tuber formation (% of cultures with microtubers), development (length and fresh weight of microtubers) and sprouting in yam Dioscorea cayenensis-D. rotundata ... [more ▼]

The effects of reducing sucrose level on tuber formation (% of cultures with microtubers), development (length and fresh weight of microtubers) and sprouting in yam Dioscorea cayenensis-D. rotundata complex in vitro were investigated. Only 29% of the explants showed tuber formation after 3 weeks in the presence of 1% sucrose in contrast to 100% with 3%. After 120 days of culture, the length and the weight of the tubers obtained in the presence of 1% sucrose were less than with 3% sucrose. Addition of sorbitol to keep osmolarity at the same level did not restore normal rate of tuber formation. Similar results were obtained with the use of reduced fructose or glucose level. Microtuber sprouting was also affected by sucrose level incorporated into the tuberisation medium. Tubers obtained on reduced sucrose level sprouted later and the increase of osmolarity with sorbitol did not restore normal sprouting. The bigger tubers obtained on high sucrose media could contain more carbohydrate reserves that could partially explain a higher sprouting rate. These results can be used for optimising in vitro conditions for mass production of microtubers in yam and especially in Dioscorea cayenensis-D. rotundata complex, a very important species in West Africa. They specially showed the importance of tuberisation conditions on precocity of tuberisation, on tuber length and weight and on their further sprouting. [less ▲]

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