References of "Delaunois, Annie"
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See detailEffet de la paille de froment et de la sciure d’épicéa sur la dégradation de l’azote urinaire en présence d’uréase
Nimenya, H.; Delaunois, Annie; Bloden, Serge ULg et al

in Annales de Médecine Vétérinaire (1999), 143

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See detailShort-term toxicity of various pharmacological agents on the in vitro nitrification process in a simple closed aquatic system
Nimenya, H.; Delaunois, Annie; La Duong, Duc ULg et al

in Alternatives to Laboratory Animals [= ATLA] (1999), 27

During the treatment of fish diseases, drugs which inhibit the nitrification process can cause acute ammonia toxicity. The same phenomenon can occur when fish are put into a tank without active cultures ... [more ▼]

During the treatment of fish diseases, drugs which inhibit the nitrification process can cause acute ammonia toxicity. The same phenomenon can occur when fish are put into a tank without active cultures of nitrifying bacteria. The purpose of this study was to quantify the inhibitory effects of 15 pharmacological agents, which are often used as therapeutic agents in ichthyopathology, on ammonia removal and nitrate production in a simple closed aquatic system. The experiments were conducted in polyethylene bags containing activated biofilters and synthetic water solutions, held in a water bath. Ammonia was added to initiate the nitrification process, and graded concentrations of various pharmacological agents were added. The effects of the pharmacological agents on in vitro nitrification were assessed by monitoring ammonia and nitrate concentrations compared to controls with no added agents, for 24 hours. Graded concentrations of ampicillin (Albipen(R)), chloramine T, enrofloxacin (Baytril(R)), erythromycin, levamisole, methylene blue and polymyxin B induced dose-dependent inhibitions of ammonia removal and nitrate production. The corresponding linear regression curves showed high correlation coefficients and were highly significant (p < 0.05). The addition of chloramphenicol, copper (II) sulphate, kanamycin disulphate, malachite green, neomycin sulphate, potassium penicillin G, tetracycline and a mixture of trimethoprim and sulphadoxin (Duoprim(TM)) had no significant effects on the nitrification process. A significant dose-related inhibition of nitrate production, but not of ammonia oxidation, was observed with enrofloxacin. The significant correlation (r = 0.940; p < 0.001) between the degrees of inhibition of ammonia oxidation and nitrate production for the various inhibitory pharmacological agents has also been calculated, with a view to validating this method. The data presented suggest that separate tank facilities for hospitalisation or quarantine are necessary when treating diseased fish with ampicillin, enrofloxacin, chloramine T, erythromycin, levamisole, methylene blue or polymyxin B, in order to avoid ammonia poisoning. [less ▲]

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See detailBiomarqueurs et bioindicateurs chez les vertébrés : importance pour l’évaluation de la santé d’un écosystème
Lessire, Françoise ULg; Delaunois, Annie; Gustin, Pascal ULg et al

in Annales de Médecine Vétérinaire (1997), 141

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See detailIntoxications par le Temik® chez les animaux domestiques et sauvages : un problème alarmant en Wallonie
Delaunois, Annie; Lessire, Françoise ULg; Ansay, M. et al

in Annales de Médecine Vétérinaire (1997), 141

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See detailRelationship between Parathion and Paraoxon Toxicokinetics, Lung Metabolic Activity, and Cholinesterase Inhibition in Guinea Pig and Rabbit Lungs
Lessire, Françoise ULg; Gustin, Pascal ULg; Delaunois, Annie et al

in Toxicology and Applied Pharmacology (1996), 138(2), 201-210

Kinetic parameters of parathion and paraoxon uptake were determined in isolated and perfused rabbit and guinea pig lungs. They were related to organophosphate-induced lung cholinesterase inhibition. A ... [more ▼]

Kinetic parameters of parathion and paraoxon uptake were determined in isolated and perfused rabbit and guinea pig lungs. They were related to organophosphate-induced lung cholinesterase inhibition. A single pass procedure was used to perfuse the lungs with an artificial medium perfusate containing paraoxon or parathion. The paraoxon and parathion concentrations were determined in the effluents collected at chosen intervals over an 18-min period beginning at the start of perfusion. Three inflowing concentrations (1 nmol/ml, 10 nmol/ml, and 20 nmol/ml) were tested in guinea pig lungs and one (10 nmol/ml) in rabbit lungs. Cholinesterase activity was determined at time 0 and at the end of the experiment. The lungs abundantly extracted paraoxon and parathion over the perfusion period. The extraction ratio was consistently greater in guinea pig than in rabbit lungs. The uptake velocity varied biexponentially in time, suggesting the existence of two compartments. Initial uptake velocities (A, B) and slopes (alpha and beta) were calculated for both compartments. In guinea pigs, A, B and A + B increased proportionally to the supply rate of paraoxon and parathion while a and b remained constant. No significant difference was observed between parathion and paraoxon uptake kinetics. Parameter B was the only one to differ significantly between the two species (rabbits: 8.19 +/- 1.53 for parathion and 6.85 +/- 1.26 for paraoxon; guinea pigs: 12.75 +/- 0.88 for parathion and 15.02 +/- 3.84 for paraoxon). In the lungs of both species, there was a linear relation between y, the percentage of cholinesterase inhibition induced by either organophosphate, and X, the total amount of drug taken up by the lung tissue (in nmol/g/18 min). The following equations were obtained: y = 0.128 x + 0.979 (R2 = 0.89, p < 0.001 for paraoxon); y = 0.120 x - 6.57 (R2 = 0.82, p < 0.005 for parathion). No difference was observed between the two organophosphates. After treatment with the cytochrome P450 inhibitor piperonyl butoxide, the above relations ceased to apply, but this treatment did not influence the kinetics of paraoxon and parathion uptake. The IC50 value calculated for paraoxon, i.e., the paraoxon concentration required to produce 50% inhibition of lung cholinesterase activity, was similar for guinea pigs (2.22 10(-7) +/- 0.22 M) and rabbits (2.36 10(-7) +/- 0.24 M). In conclusion, the biexponential evolution of the velocity of paraoxon and parathion uptake by the lungs thus demonstrates the presence of two pools. The lower extraction ratios calculated for rabbit lungs reflect the lower initial uptake velocity of the second compartment. In the range of concentrations investigated in guinea pigs, no saturable mechanism could be demonstrated for paraoxon and parathion. Cytochrome P450-related lung metabolic activity, through which parathion is converted to paraoxon, appears as a major step in parathion-induced lung cholinesterase inhibition, although it does not appear to affect parathion toxicokinetics [less ▲]

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See detailPermeability of the Endothelium and Partitioning of the Pulmonary Blood Flow Resistance in Isolated Perfused Pig Lungs: Effects of Breed and Age
Gustin, Pascal ULg; Urbain, B.; Delaunois, Annie et al

in Veterinary Research Communications (1992), 16(1), 69-82

The right and left lungs of 5 healthy Minipigs and of 13 healthy Landrace piglets were isolated, perfused at constant pressure and maintained in an isogravimetric state under zone III conditions ... [more ▼]

The right and left lungs of 5 healthy Minipigs and of 13 healthy Landrace piglets were isolated, perfused at constant pressure and maintained in an isogravimetric state under zone III conditions (pulmonary venous pressure greater than alveolar pressure). By applying the double, arterial and venous, occlusion technique, the total blood flow resistance (R) was partitioned into four components: arterial (Ra), pre- (Ra') and post-capillary (Rv') and venous (Rv). The capillary filtration coefficient (Kf,c) was evaluated by measuring the weight gained by the lungs when the arterial and venous pressures were suddenly increased. In the youngest Landrace piglets (5 weeks old), there was an uncontrolled vasoconstriction which sometimes prevented perfusion of the lungs and induced a large increase in Rt. These high values of Rt were decreased by tolazoline administration. The values of Rt recorded in older pigs (12-13 weeks old) were lower in Minipigs (33.66 +/- 3.77 cmH2O min L-1 per 100 g of lungs; n = 5) than in Landrace piglets (55.20 +/- 6.18 cmH2O min L-1 per 100 g; n = 5). This breed difference was due to the differences in Ra' and Rv'. The mean values of Kf,c were 0.193 +/- 0.015 and 0.202 +/- 0.029 ml min (cmH2O)-1 per 100 g of the lungs in Minipigs and Landrace piglets respectively. All these parameters were stable for the 3 hours following the equilibrium period. It was concluded that: (1) There is an age-related maturation of the control of the vasomotor tone in porcine lungs. (2) Pulmonary microvascular haemodynamics are influenced by the breed of the pigs. (3) There was no difference in the Kf,c values between both the breeds. (4) A comparison of the values reported for dogs and rabbits with our data shows that the pre- and post-capillary resistances and, to a lesser extent, the arterial and venous resistances are relatively high in pigs [less ▲]

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See detailAltered Capillary Filtration Coefficient in Parathion- and Paraoxon-Induced Edema in Isolated and Perfused Rabbit Lungs
Delaunois, Annie; Gustin, Pascal ULg; Ansay, Michel

in Toxicology and Applied Pharmacology (1992), 116(2), 161-169

Changes in pulmonary endothelium permeability and in microvascular hemodynamics induced by parathion (Pth) and paraoxon (Pox), its active metabolite, were investigated in isolated, perfused rabbit lungs ... [more ▼]

Changes in pulmonary endothelium permeability and in microvascular hemodynamics induced by parathion (Pth) and paraoxon (Pox), its active metabolite, were investigated in isolated, perfused rabbit lungs. Blood-free perfusate was recirculated through isolated and ventilated lungs in an isogravimetric state and in zone III conditions. The arterial/venous/double occlusion technique was used to divide the total vascular resistance (Rt) into four components: arterial, precapillary, postcapillary, and venous. The capillary filtration coefficient (Kfc) was evaluated by measuring the amount of fluid filtering through the endothelium when the arterial and venous pressures were suddenly increased. Pth and Pox induced pulmonary edema by increasing endothelium permeability without changing the hemodynamic parameters at any level of the vascular bed. The Kfc value increased progressively, reaching a maximum (Emax) 60 min after administration of organophosphate (558 ± 65% (n = 5) and 707 ± 109% (n = 5) of baseline values, for Pth and Pox, respectively). During the next 60 min, it decreased. The time course of Pox-induced changes in Kfc was similar to that obtained with Pth. The concentration-response curve (Emax) expressed as a percentage of the baseline value versus the logarithm of the malor Pth concentration, ranging from 2 × 10−5 to 4 × 10−4 image) was linear (y = 1661.1 + 327.3x, R = 0.89, p < 0.001, N = 14). Piperonyl butoxide (4 × 10−4 image), an inhibitor of cytochrome P450, had a strong protective effect against Pth (4 × 10−4 image)-induced alterations of endothelium permeability (n = 5, p < 0.001). The effects of Pox (4 × 10−4 image) on Kfc were completely abolished by pretreatment with 10−5 image atropine, as shown by the significantly lower Emax value recorded in atropine-pretreated lungs (129 ± 33%, n = 4) than in Pox-treated lungs (707 ± 109%, n = 5, p < 0.001). The effects of Pth, on the other hand, were only partially inhibited, since the Emax value recorded in atropine-pretreated lungs (196 ± 20%, n = 4) remained significantly higher than that recorded for control lungs (129 ± 15%; n = 5; p < 0.05). These results show that isolated and perfused rabbit lungs constitute and appropriate model for studying the direct pulmonary effects of organophosphates. The edema-inducing action of Pth depends on its activation by conversion to Pox in the lung tissue. It can be explained by an increase in endothelium permeability. This effect is mediated principally by muscarinic receptors [less ▲]

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