References of "Linden, Annick"
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See detailHemodynamic Responses to Pasteurella Haemolytica Inoculation in Calves Given Type 2 Serotonergic Antagonist
Desmecht, Daniel ULg; Linden, Annick ULg; Amory, Hélène ULg et al

in Canadian Journal of Physiology & Pharmacology (1996), 74(5), 572-9

The effects of saline (control, group C) and metrenperone (treated, group M) on systemic and pulmonary hemodynamics were determined in conscious 7- to 15-day-old calves after they were intratracheally ... [more ▼]

The effects of saline (control, group C) and metrenperone (treated, group M) on systemic and pulmonary hemodynamics were determined in conscious 7- to 15-day-old calves after they were intratracheally inoculated with Pasteurella haemolytica. Metrenperone, a specific serotonin (5-hydroxytryptamine) receptor antagonist, was injected intramuscularly (100 micrograms.kg-1) 2 h after the calves were inoculated. Central venous, pulmonary arterial and capillary wedge, and systemic arterial pressures were measured, using fluid-filled catheters. Cardiac output was measured by the thermodilution technique. Heart rate, stroke volume, and pulmonary and systemic vascular resistances were calculated. The parameters were measured hourly from the 1st to the 10th h after inoculation. In group C, cardiovascular response to P. haemolytica inoculation was marked and typically consisted of two systemic hypotensive phases and two pulmonary hypertensive phases. The first phase occurred by the 2nd h post inoculation and was induced by a transient bradycardia and a systemic vasodilation, leading to profound hypotension and reduced venous return. Cardiac performance then transiently recovered, but systemic hypotension persisted. The second hypotensive hypodynamic phase occurred by the 7th h after inoculation, and was associated with a decline in stroke volume, an increase in heart rate, and pulmonary hypertension and vasoconstriction. In group M, the early response to P. haemolytica exposure was similar to that in controls, indicating that, as in sheep, 5-hydroxytryptamine does not contribute to the early hypodynamic response to endotoxemia. In contrast, metrenperone completely abolished late increases in pulmonary arterial pressure and pulmonary vascular resistance, suggesting that 5-hydroxytryptamine contributes to the late pulmonary vasoconstriction. Metrenperone treatment also allowed better restoration of heart rate, and hence, cardiac output was maintained. In conclusion, 5-hydroxytryptamine might have a role in mediating pasteurellic endotoxin induced changes in pulmonary hemodynamics through its type-2 receptors. [less ▲]

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See detailEffect of serotonergic blockade on calf pulmonary function after the intravenous administration of 3-methylindole
Linden, Annick ULg; Desmecht, Daniel ULg; Vandenput, Sandrina ULg et al

in Journal of Comparative Pathology (1996), 114(4), 361-371

This study was designed to investigate whether 3-methylindole (3-Mi), a tryptamine analogue, could cause pulmonary injury in calves other than by cytotoxicity. Injection of 3-Mi resulted in a marked ... [more ▼]

This study was designed to investigate whether 3-methylindole (3-Mi), a tryptamine analogue, could cause pulmonary injury in calves other than by cytotoxicity. Injection of 3-Mi resulted in a marked increase of respiratory rate, decrease of tidal volume and increase in minute ventilation. Pulmonary mechanics values were also profoundly affected, lung dynamic compliance being reduced to approximately one-third of its baseline value and total pulmonary resistance being increased two-fold. Arterial oxygen partial pressure was dramatically reduced. Successive challenges with 3-Mi after physiological saline pretreatment resulted in quantitatively identical alterations of pulmonary function values. Conversely, all these ventilatory, mechanical and gas exchange changes were abolished by pretreatment with serotonergic antagonists. It was concluded that intravenous administration of 3-Mi to healthy calves induced immediate and reversible bronchoconstriction which affected both central and peripheral airways. Because the effect was abolished by pretreatment with antiserotonin drugs, it is suggested that 3-Mi acts either directly by stimulating serotonergic receptors or indirectly through the release of serotonin from platelets. Current concepts of the physiopathological cascade underlying the toxicity of 3-Mi should, therefore, be re-evaluated in the light of this pharmacological mechanism. [less ▲]

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See detailRelationship of Plasma Lactate Production to Cortisol Release Following Completion of Different Types of Sporting Events in Horses
Desmecht, Daniel ULg; Linden, Annick ULg; Amory, Hélène ULg et al

in Veterinary Research Communications (1996), 20(4), 371-379

Fifty-eight healthy horses were studied during five sporting events of various intensities and durations, namely show-jumping (n = 6), cross-country in a three-day event (n = 30), trotting races (n = 7 ... [more ▼]

Fifty-eight healthy horses were studied during five sporting events of various intensities and durations, namely show-jumping (n = 6), cross-country in a three-day event (n = 30), trotting races (n = 7), galloping races (n = 7) and endurance rides (n = 8). Venous blood samples were collected at rest and immediately after exercise and analysed for plasma cortisol (CORT) and lactate (LA) levels. The experimental procedure was the same throughout the investigation so as to permit a reliable comparison between the five types of exercise. The type of event significantly affected both the resting (p < or = 0.05) and the post-exercise (p < or = 0.01) plasma CORT. The degree of exercise-induced hypercortisolaemia was related to both the intensity and the duration of exercise for all five sporting events, but the endurance ride induced the most and show-jumping the least serious post-exercise CORT changes. LA production was much more closely related to the intensity of the exercise than was CORT. It is concluded that simultaneous measurements of plasma CORT and LA levels may be useful to discriminate between different types of exercise, adjust training programmes, and improve our comprehension of the physiology of sport horses at exercise. [less ▲]

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See detailThe relation of ventilatory failure to pulmonary, respiratory muscle and central nervous system disturbances in calves with an experimentally produced pneumonia
Desmecht, Daniel ULg; Linden, Annick ULg; Lekeux, Pierre ULg

in Journal of Comparative Pathology (1996), 115(3), 203-219

To explore the pathophysiology of respiratory failure in an experimental pneumonia, a Pasteurella haemolytica broth culture was injected intratracheally into 12 calves, which were then studied over a ... [more ▼]

To explore the pathophysiology of respiratory failure in an experimental pneumonia, a Pasteurella haemolytica broth culture was injected intratracheally into 12 calves, which were then studied over a period of 10 h. Measurements were made of inspired minute ventilation VE), ventilatory pattern [inspiratory time (TI), expiratory time (TE), respiratory rate (RR) and tidal volume (VT)], transdiaphragmatic pressure (Pdi), occlusion pressure at the airway opening 100 milliseconds after onset of inspiration (Pawo100ms), arterial blood gas tensions and pH and recorded diaphragmatic electromyogram (EMGdi) and rectal temperature (Tr). On and after the third hour after inoculation, the animals varied in respect of clinical signs, Tr, RR, VE, Pawo100ms/EMGdi, and arterial gases and pH. In benign cases, diminished alertness, laboured respiration and fall of arterial oxygen pressure (PaO2) worsened up to 7 h after inoculation, but then progressively improved, VE being maintained at approximately 150% baseline throughout the study (10 h). Neither arterial carbon dioxide pressure (PaCO2) nor pH was altered. Moderate cases resembled benign cases in respect of laboured respiration, VE, PaO2 and PaCO2; however, pH was at first maintained at preinoculation levels, but declined thereafter. In severe cases, the animals were drowsy between hours 3 and 7, and became comatose between hours 8 and 10; in contrast to both benign and moderate cases: (1) RR was reduced by hour 5, (2) there was no trend towards recovery of PaO2 and pH, (3) VE, Pdi, Pawo100ms and Pawo100ms/EMGdi were severely decreased, and (4) PaCO2 increased. These results suggest that pneumonia does not alter ventilatory neuromuscular pump function in calves, unless concomitant cardiovascular collapse occurs. It is not clear whether fatal ventilatory failure is caused mainly by deterioration in ventilatory muscle fibre processes or structures, altered central nervous system adjustment of ventilatory timing, or cardiovascular dysfunction. However, inspiratory pressures fall when excitation to the diaphragm is still growing, which suggests peripheral respiratory muscle fatigue. [less ▲]

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See detailControl of breathing in healthy and pasteurella-exposed calves after 5-HT receptor blockade
Rollin, Frédéric ULg; Close, R; Linden, Annick ULg et al

in Proceedings of the XIXth World Association for Buiatrics Congress (1996)

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See detailProphylactic activity of metrenperone-MDL 72222 association in calves given intravenous 3-methyl-indole
Desmecht, Daniel ULg; Linden, Annick ULg; Lekeux, Pierre ULg

in Pflügers Archiv : European Journal of Physiology (1996), 431

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See detailHaemodynamic dysfunctions involved in experimental bovine pneumonic pasteurellosis
Desmecht, Daniel ULg; Amory, Hélène ULg; Linden, Annick ULg et al

in Journal of Experimental Animal Science (1996), 37

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See detailRuminal, cardiorespiratory and adrenocortical sequelae of Na2EDTA-induced hypocalcemia in calves
Desmecht, Daniel ULg; Linden, Annick ULg; Lekeux, Pierre ULg

in Veterinary Research Communications (1996), 20

A study was undertaken to provide further information on the ruminal, cardiorespiratory and hypothalamo-pituitary-adrenocortical (HPAC) physiological sequelae of hypocalcaemia in dairy calves. The ... [more ▼]

A study was undertaken to provide further information on the ruminal, cardiorespiratory and hypothalamo-pituitary-adrenocortical (HPAC) physiological sequelae of hypocalcaemia in dairy calves. The functional picture observed in standing calves experiencing Na2EDTA-induced progressive hypocalcaemia showed a biphasic pattern. During the first phase (Ca2+ varying between 1.20 +/- 0.09 and 0.64 +/- 0.15 mmol/L, mean +/- SD), the animals became dull and lethargic, shifting their weight from one hind limb to the other, with cool extremities and hypersalivation. Their ventilation was slightly increased but their heart rate, thoracoabdominal pressure, pulmonary mechanics, haemoglobin and temperature remained constant. Conversely, their systemic arterial pressure (SAP) and the amplitude of their ruminal contractions (RCA) were severely decreased. During the second phase (Ca2+ < 0.64 +/- 0.15 mmol/L), there was restlessness, tachycardia, hypertension, polycythaemia and, finally, inability to stay upright. It is suggested that the diminished Ca2+ availability caused smooth-muscle and myocardial dysfunctions which could explain the RCA and SAP changes recorded during the first phase, whereas neural and/or humoral sympathetic discharge probably accounted for the reversal in SAP and heart rate when Ca2+ was decreased further. Serum cortisol increased regularly and remained significantly correlated with Ca2+ in each animal. Moreover, regression of delta cortisol/delta Ca2+ on delta Ca2+/delta Na2EDTA was significant (p < or = 0.001). It was concluded that mild asymptomatic hypocalcaemia severely impairs ruminal function, which will progressively worsen the Ca2+ deficit; that the inability to maintain posture in hypocalcaemia is not due to hypotension; and that the higher the HPAC response to hypocalcaemia, the higher the resistance to its effects. An asymptomatic periparturient cow with barely detectable ruminal activity may merit preventive calcium borogluconate therapy. Also, the physiological role of hypotension in explaining the clinical picture may be less important than other processes, such as neuromuscular failure. Finally, the present results imply a possible HPAC exhaustion in cows with periparturient paretic hypocalcaemia [less ▲]

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See detailDe l'effet du transport sur la cortisolémie du cheval de sport (première thèse annexe)
Linden, Annick ULg

Thèse d’agrégation de l’enseignement supérieur (1996)

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See detailMécanismes moléculaires et cellulaires de la pathogénie bactérienne (leçon publique)
Linden, Annick ULg

Thèse d’agrégation de l’enseignement supérieur (1996)

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See detailEffet de la compétition sur la formule leucocytaire et la cortisolémie du cheval de concours complet (troisième thèse annexe)
Linden, Annick ULg

Thèse d’agrégation de l’enseignement supérieur (1996)

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See detailElectrophysiologic evaluation of the phrenic nerve-diaphragm pathway in an intact conscious calf model
Desmecht, Daniel ULg; Linden, Annick ULg; Lekeux, Pierre ULg

in American Journal of Veterinary Research (1995), 56(5), 545-554

Owing to technical and ethical limitations, a substantial part of the knowledge about the pathophysiologic mechanism of the human diaphragm has been obtained from studies in which phrenic nerve activation ... [more ▼]

Owing to technical and ethical limitations, a substantial part of the knowledge about the pathophysiologic mechanism of the human diaphragm has been obtained from studies in which phrenic nerve activation was usually carried out by direct surgical exposure of the nerves in the neck of deeply anesthetized, mechanically ventilated animals. Novel information has been gleaned from such studies, but the restrictive conditions under which it was collected preclude reliable extrapolation. We, therefore, addressed the question of whether accurate electrophysiologic evaluation of the phrenic nerve-diaphragm pathway can be performed in intact, nonanesthetized calves. Transjugular phrenic activation was well tolerated, safe, specific, and able to achieve constant symmetric and supramaximal phrenic stimulations during prolonged periods. Eighteen noninvasive cutaneous and esophageal reception circuits were tested for their ability to record the diaphragmatic evoked potential. In addition, they were compared for specificity and reproducibility of the recorded potentials during prolonged periods of tidal or stimulated respiration. The best diaphragmatic potential was recorded from surface electrodes attached to the skin of the ninth and tenth intercostal spaces, using a xyphoidian reference. We describe a method that allows easy, longterm, and reliable electrophysiologic evaluation of the phrenic nerve-diaphragm pathway in intact, conscious calves. It is hoped that such a model will produce relevant novel information regarding pathophysiology of the diaphragm. [less ▲]

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See detailValidation of Creatine, Glycogen and L-(+)-Lactate Determination in Biopsy Samples of Bovine Musculus Diaphragma
Desmecht, Daniel ULg; Linden, Annick ULg; Cuvelier-Klimek, M. et al

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (1995), 42(1), 13-26

Whereas reliable measurements of diaphragmatic force and electrical activity are now available in calves, evidence that substrate contents in the bovine diaphragm can be accurately measured is still ... [more ▼]

Whereas reliable measurements of diaphragmatic force and electrical activity are now available in calves, evidence that substrate contents in the bovine diaphragm can be accurately measured is still lacking. The purposes of the present study were therefore a) to describe and test the reliability of methods and procedures used for sampling, lyophilisation, extraction and dosage of muscular lactate, glycogen and creatine contents and b) to report the variation in their levels found along the bovine diaphragm and among individuals. The repeatability of the results yielded by a) assaying the extracts, b) processing and assaying the extracts and c) taking samples at different sites in the muscle was assessed. Neither assay, nor processing effects were significant (P < or = 0.05). Substrates were found to be homogeneously distributed within the two muscles studied. Substrate contents expressed per unit of muscle weight or total creatine were neither more or less variable than when expressed per unit of dry matter. [less ▲]

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See detailMaximal cardiac pumping capacity in double-muscled cattle as determined by a pharmacological test
Amory, Hélène ULg; Mc Entee, Kathleen ULg; Linden, Annick ULg et al

in Pflügers Archiv : European Journal of Physiology (1995), 430

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See detailEffect of adenosine IV administration on gas exchanges and hemodynamics in unsedated calves with hypoxic vasoconstruction
Van de Weerdt, Marie-Lys; Desmecht, Daniel ULg; Vandenput, Sandrina ULg et al

in Pflügers Archiv : European Journal of Physiology (1995), 430(5), 186

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See detailInvolvement of 5-hydroxytryptamine in hyperdynamic pulmonary hemodynamics in endotoxemic calves
Desmecht, Daniel ULg; Linden, Annick ULg; Amory, Hélène ULg et al

in Pflügers Archiv : European Journal of Physiology (1995), 429

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See detailHemodynamic effects of intratracheal administration of Pasteurella haemolytica in calves
Amory, Hélène ULg; Linden, Annick ULg; Desmecht, Daniel ULg et al

in Pflügers Archiv : European Journal of Physiology (1995), 430

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