References of "Amory, Hélène"
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See detailPulmonary mechanics and inductance plethysmography as noninvasive tools to detect a bilateral diaphragmatic paralysis in a pony
Amory, Hélène ULg; Lomba, F; Lekeux, Pierre ULg et al

in Proceedings of the 3d Congress of the World Equine Veterinary Association (1993)

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See detailComparative study of the body surface electrocardiogram in double-muscled and conventional calves.
Amory, Hélène ULg; Rollin, Frédéric ULg; Genicot, Bruno et al

in Canadian Journal of Veterinary Research = Revue Canadienne de Recherche Vétérinaire (1993), 57(3), 139-45

The purpose of this work was to study electrocardiographic features of double-muscled beef cattle. Electrocardiograms were recorded on one to six occasions from each of a group of 18 conventional calves ... [more ▼]

The purpose of this work was to study electrocardiographic features of double-muscled beef cattle. Electrocardiograms were recorded on one to six occasions from each of a group of 18 conventional calves of the Friesian breed and 29 double-muscled calves of the Belgian White and Blue breed. Ages of the calves at the times of examination ranged from eight to 348 days. The Holmes semi-orthogonal lead system was used. The waves and interval durations and the tridimensional P, QRS, and T modal vector orientation and amplitude were calculated. The magnitude of the cardiac vectors was significantly lower and the ventricular waves and QT interval duration significantly shorter in the double-muscled than in the conventional calves. The P modal vector pointed significantly less downwards and the QRS modal vector pointed significantly more forwards and less up- and rightwards in the Belgian White and Blue, than in the Friesian group. Most of the observed differences might be a consequence of the bodily, and more specifically the thoracic, conformation of the former calves. However, the lower cardiac vector magnitude and shorter wave and interval durations might also reflect lower cardiac mass in the double-muscled subjects. [less ▲]

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See detailComparison of the cardiac pumping capability and cardiac pumping reserve in double muscled and conventional calves
Amory, Hélène ULg; Mc Entee, Kathleen ULg; Linden, Annick ULg et al

in Canadian Journal of Physiology & Pharmacology (1993), 71(12), 946-951

Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional ... [more ▼]

Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional commercial value but ones with a lower aerobic capacity than that of conventional cattle. The purpose of this work was to study the role of cardiac function as a potential limiting factor of aerobic capacity in double-muscled calves. Two groups of healthy calves were studied, one consisting of nine calves of conventional conformation and the other of nine double-muscled calves. Pulmonary arterial and capillary wedge, central venous, and systemic arterial pressures were measured by fluid-filled catheters and recorded together with the electrocardiogram. Cardiac output was measured by the thermodilution technique. From these measurements, the heart rate, the cardiac and the stroke indices, the pulmonary and the systemic vascular resistances, and the cardiac power output were calculated. The parameters were recorded under basal resting conditions and during incremental dobutamine challenge, which allowed determination of the resting cardiac power output, the cardiac pumping capability, and the cardiac reserve. Dobutamine challenge induced a significant rise in cardiac and stroke indices, heart rate, and cardiac power output, a significant decrease in pulmonary and systemic vascular resistances, and no change in systemic and pulmonary arterial pressures. The cardiac reserve obtained in the present study was low in comparison with those previously reported in humans, dogs, and horses. This may be related to the poor running capability of bovine species relative to that of the former species.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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See detailPhysiological response to the cross country phase in eventing horses
Amory, Hélène ULg; Art, Tatiana ULg; Linden, Annick ULg et al

in Journal of Equine Veterinary Science (1993), 13

Blood samples were collected for lactate concentration determination (Lacc) at the arrival of the cross-country phase from 40 horses of various class levels competing in 6 different three-day events ... [more ▼]

Blood samples were collected for lactate concentration determination (Lacc) at the arrival of the cross-country phase from 40 horses of various class levels competing in 6 different three-day events. Moreover, in 8 horses, heart rate (HR) was recorded every 5 seconds during the cross-country. Among them, 5 horses were submitted, at the beginning of the competition's season to a standardized exercise test (SET) on a track which allowed us to study the relationship between HR, blood lactate concentration and running speed on flat ground in these horses. The relationship between mean HR and mean speed, between Lacc and mean speed and between Lacc and HR during the cross-country were studied using regression analysis. Mean HR during the cross-country was linearly related to mean speed during this phase (r=0.87, p ≤ 0.01), but this relationship was shifted upwards in comparison with the corresponding curve obtained during the SET (r=0.97, p ≤ 0.001). In the same way, the relationship between Lacc and mean speed during the cross-country was exponential (r=0.93, p ≤ 0.001), but blood lactate accumulation occurred at a lower speed than during the SET (r=0.94, p ≤ 0.001). The correlation between Lacc and HR was stronger when Lacc was related to HR during the 15 last minutes of the cross (r = 0.84) than to mean HR during the whole cross (r = 0.75) or to HR during the 2 last (r = 0.74) or the last (r = 0.80) minute of the course, which indicated that continuous recording of HR allowed a more accurate estimation of the severity of exercise performed during the cross-country than Lacc. Heart rate ranged from 170 to 190 beats/min during the first part of the cross-country and reached or exceeded values of 190 to 200 beats/min at the end of the course. Therefore, the anaerobic threshold is reached during cross-country. Recruitment of anaerobic me tabolism at the end of the course was otherwise demonstrated by the high values of Lacc. These aerobic-anaerobic meta bolic requirements should be taken into account to design the training program of an eventing horse. [less ▲]

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See detailComparison of three metrenperone dosage regimens inhibiting the 5-hydroxytryptamine-induced pulmonary dysfunction in cattle
Linden, Annick ULg; Desmecht, Daniel ULg; Amory, Hélène ULg et al

in Research in Veterinary Science (1993), 55

The effects of a 5-hydroxytryptamine (5-HT) challenge infusion on pulmonary function values were studied in healthy calves, pretreated with varying doses of metrenperone, a selective type 2 serotonergic ... [more ▼]

The effects of a 5-hydroxytryptamine (5-HT) challenge infusion on pulmonary function values were studied in healthy calves, pretreated with varying doses of metrenperone, a selective type 2 serotonergic (5-HT2) antagonist. In the first part of the experiment, the 5-HT challenge was performed 30 minutes after administration of metrenperone at a dose of 0.025 mg kg-1 (group 1, n = 8), 0.050 mg kg-1 (group 2, n = 8) and 0.100 mg kg-1 (group 3, n = 7). In the second part, the 5-HT challenge was performed 12 hours after administration of metrenperone at a dose of 0.050 mg kg-1 (group 4, n = 5) and 0.100 mg kg-1 (group 5, n = 5). None of the three doses of metrenperone influenced the 5-HT-induced ventilatory changes. For the challenge performed 30 minutes after blockade, all three doses inhibited the bronchoconstrictive process triggered by the 5-HT challenge. There was no dose-related inhibition. On the other hand, when the challenge was performed 12 hours after metrenperone, there was a dose-related inhibition with only the higher dose (0.100 mg kg-1) showing a significant efficacy in inhibiting 5-HT-induced bronchoconstriction. It is concluded that, if 5-HT is involved in the pathophysiological processes of respiratory diseases in cattle, a 5-HT2 blockade with metrenperone at a dose rate of 0.100 mg kg-1 and with a dosage interval of 12 hours should improve pulmonary function. [less ▲]

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See detailAn experimental trial of intramuscular metrenperone to induce respiratory improvement during pneumonia in neonatal calves
Linden, Annick ULg; Desmecht, Daniel ULg; Amory, Hélène ULg et al

in Archives Internationales de Physiologie et de Biochimie (1993)

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See detailCardiovascular Response to Acute Hypoxia in Double-Muscled Calves
Amory, Hélène ULg; Rollin, Frédéric ULg; Desmecht, Daniel ULg et al

in Research in Veterinary Science (1992), 52(3), 316-24

Hypoxic-induced pulmonary hypertension is known to be intensive in the bovine species and sometimes leads to pathological cardiac repercussions. On the other hand, doubled-muscled cattle are predisposed ... [more ▼]

Hypoxic-induced pulmonary hypertension is known to be intensive in the bovine species and sometimes leads to pathological cardiac repercussions. On the other hand, doubled-muscled cattle are predisposed to develop hypoxaemia during exercise and with respiratory diseases. Therefore the purpose of this study was to investigate the cardiovascular response to acute hypoxia in double-muscled calves compared with calves of standard conformation. Pulmonary arterial pressure, electrocardiogram and blood temperature were simultaneously recorded, arterial blood was sampled for blood gas analysis and cardiac output was determined in six Friesian calves and six double-muscled calves of the Belgian White and Blue breed(BWB) when breathing air (fractional inspiratory oxygen concentration [FIO2]: 21 per cent) and when breathing a hypoxic gas mixture (FIO2: 10 per cent). All the absolute values of the measured parameters were significantly (P less than or equal to 0.001) different between the two breeds, except heart rate and arterial blood gas values. The pattern of hypoxic-induced decrease in arterial PO2 was similar in the two breeds of calves, suggesting that the pulmonary exchange capacities during hypoxia are no less efficient in double-muscled calves than in calves of standard conformation. Similarly, the percentage of variation of the mean pulmonary arterial pressure from its normoxic to its hypoxic value was the same in the two breeds of calves, suggesting that double-muscled calves are not predisposed to develop a more precocious or more intense pulmonary hypertension for a given level of hypoxaemia. The significantly smaller normoxic and hypoxic cardiac index and stroke index found in BWB compared with Friesian calves was interpreted as a less efficient cardiac function in double-muscled subjects. [less ▲]

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See detailEffect of intravenous and aerosol administration of 5-hydroxytryptamine on pulmonary function values in healthy calves
Desmecht, Daniel ULg; Linden, Annick ULg; Rollin, Frédéric ULg et al

in American Journal of Veterinary Research (1992), 53(3), 315-320

Effects of IV and aerosol administration of 5-hydroxytryptamine (5-HT) on ventilation, pulmonary mechanics values, pulmonary arterial pressure, and heart rate were investigated in healthy unsedated ... [more ▼]

Effects of IV and aerosol administration of 5-hydroxytryptamine (5-HT) on ventilation, pulmonary mechanics values, pulmonary arterial pressure, and heart rate were investigated in healthy unsedated Friesian calves. Minute volume increased significantly, mainly because of an increase in respiratory rate. Except for total pulmonary resistance after bolus injection, continuous administration of 5-HT given by either route caused significant alterations of lung dynamic compliance and total pulmonary resistance, the former decreasing to one-fifth of its baseline value and the latter increasing twofold. Pulmonary arterial pressure increased significantly, whatever the speed or route of administration. Administration of a bolus did not affect heart rate, whereas continuous IV administration of 5-HT as well by perfusion or by aerosol resulted in sustained tachycardia. It was concluded that 5-HT induces reversible bronchoconstriction and pulmonary vasoconstriction in healthy unsedated calves, 5-HT-induced functional alterations depend on the speed of administration, and excess of 5-HT production or depression in uptake by the lungs during bovine respiratory tract diseases could contribute to pulmonary dysfunction. [less ▲]

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See detailInfluence of training on ventilatory and cardio-respiratory parameters measured during a standardised exercise in thoroughbred horses
Art, Tatiana ULg; Votion, Dominique ULg; Mc Entee, K et al

in Proceedings of the 11th Comparative Respiratory Society Meeting (1992)

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See detailTraining-induced changes in cardio-respiratory parameters during a standardised exercise in thoroughbred horses
Art, Tatiana ULg; Votion, Dominique ULg; Mc Entee, K et al

in Archives Internationales de Physiologie et de Biochimie (1992)

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See detailMeasurement of leg blood flow in calves by the thermodilution method : a technical study
Mc Entee, K; Amory, Hélène ULg; Genicot, B et al

in Archives Internationales de Physiologie et de Biochimie (1992)

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See detailEffets du blocage des recepteurs serotonergiques de type 2 sur les modifications fonctionnelles respiratoires induites par un challenge à la sérotonine chez le bovin
Linden, Annick ULg; Desmecht, Daniel ULg; Amory, Hélène ULg et al

in In Proceedings of the XVIIth World Buiatrics Congress, St Paul, USA, August 1992, 3, 405-410 (1992)

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See detailLa fatigue du diaphragme: un risque vital au cours des pneumonies ?
Desmecht, Daniel ULg; Linden, Annick ULg; Amory, Hélène ULg et al

in Proceedings of the XVIIth World Buiatrics Congress (1992)

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See detailVentilatory effects of rebreathing CO2 in two breeds of calves
Rollin, Frédéric ULg; Desmecht, Daniel ULg; Linden, Annick ULg et al

in Archives Internationales de Physiologie et de Biochimie (1992)

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See detailEffect of experimentally induced acute pneumonia on diaphragmatic strength generation in neonatal calves
Desmecht, Daniel ULg; Linden, Annick ULg; Amory, Hélène ULg et al

in Archives Internationales de Physiologie et de Biochimie (1992)

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See detailApplication of vectocardiography in cattle
Amory, Hélène ULg; Genicot, B; Rollin, Frédéric ULg et al

in Proceedings of the XVIth World Buiatrics Congress (1992)

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See detailEffect of the double-muscled conformation selection on the cardiovascular function in cattle
Amory, Hélène ULg; Desmecht, Daniel ULg; Linden, Annick ULg et al

in Archives Internationales de Physiologie et de Biochimie (1992)

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