Search PubMed⌕ Search

Biomedical subjects

A Dallaire

Publications and source records attributed to A Dallaire.

14 recordsLinked to original sources
PubMed1996

Urinary protein excretion of semidomesticated mink in a chronic methylmercury study.

A model using semidomesticated mink was set up to study the effects of chronic oral methylmercury exposure in piscivorous mammals. Three groups of mink were fed daily with diets containing approximately 0.1, 0.5, and 0.9 micrograms/g of total mercury. Piscivorous and non-piscivorous fish, naturally contaminated with methylmercury, were used to prepare diets. Renal injury was evaluated using total urine protein/creatinine ratio and differentiation of urinary low-molecular-weight and high-molecular-weight proteins on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The significance of the total urine protein/creatinine ratio data was assessed by comparing the results to a 95% group-based reference interval. The values for total urine protein/creatinine ratio did not reveal any significant increased excretion, and no dose-related trends were observed within the reference interval. Overall the total urine protein data did not suggest renal damage. Analysis of the SDS-PAGE electrophoretograms did not suggest the presence of any persistent glomerular damage in any group. High-molecular-weight proteins were not detected more frequently for any of the dose groups. During the adaptation phase, the B2M-like protein band was not remarked during the visual analysis of the gels. The B2M-like protein band was remarked during the gel analysis only several weeks into the exposure phase. This B2M-like protein band was more prevalent in urine samples taken from minks in the 0.5 and 0.9 micrograms/g groups than in the 0.1 microgram/group. These latter data, however, did not allow an evaluation of a quantitative dose-response excretion with time. The B2M-like data are suggestive of very minor renal injury.

Albuminuria↗
PubMed1993

Genetic epidemiology of sensorimotor polyneuropathy with or without agenesis of the corpus callosum in northeastern Quebec.

Sensorimotor polyneuropathy with or without agenesis of the corpus callosum (McKusick number 218000) is a disorder that has a high frequency in Saguenay-Lac-St-Jean (SLSJ), a geographically isolated region of north-eastern Quebec. The incidence at birth and the carrier rate were estimated, respectively, at 1/2117 liveborns and 1/23 inhabitants. Remote consanguinity was found in several polyneuropathic families while the mean kinship coefficient was 2.7 times higher in the polyneuropathic group than in control groups. The birth places of the individuals with sensorimotor polyneuropathy and their parents did not show a clustered nonuniform distribution. The genealogical reconstruction suggests that the high incidence of polyneuropathy in SLSJ is likely to be the result of a founder effect. It also suggests that a unique mutation accounts for most, if not all, of the cases of sensorimotor polyneuropathy known in this region.

Agenesis of Corpus Callosum↗
PubMed1986

Polygraphic analysis of the sleep-wake states and the REM sleep periodicity in domesticated pigs (Sus scrofa).

Electrocorticography and concurrent electromyography were used during a total of nineteen 24 hr periods in three juvenile pigs in order to establish the quantitative duration of the sleep-wake states and the REM sleep cycles. Wakefulness (W), drowsiness (DR), slow-wave sleep (SWS) and paradoxical sleep (REM) occupied respectively 46.5%, 15.9%, 26.7% and 10.9% of the 24 hr period. Mean duration of episodes was 4.1 min for DR, 6.2 min for SWS and 3.3 min for REM. Sleep cycles (SC) duration was 13.1 min. Near 80% of the SC were nocturnal. Analysis of variance showed a significant difference between diurnal and nocturnal duration of SC (day less than night), as well as between day-time and night-time duration of DR (day greater than night), SWS (day less than night) and REM (day less than night). A strong negative correlation was also found between the mean duration of SC and the number of SC per day.

Animals↗
PubMed1986

Rest behavior.

Behavioral and physiologic characteristics of sleep are described, with special attention paid to equids. Temporal organization of sleep and environmental influences upon this behavior in horses are reviewed. Anatomic and biochemical bases and function of sleep are discussed briefly.

Animals↗
PubMed1985

Premedication of dogs with acepromazine or pentazocine before euthanasia with carbon monoxide.

Euthanasia of unwanted or sick animals should always be done in a humane manner. This study involving two groups of 12 dogs evaluated a two step method of euthanasia using first acepromazine or pentazocine then inhalation of carbon monoxide. During the experiment, behavioral reactions (anxiety, agitation, vocalization and sphincter relaxation) and physiological parameters (electro-encephalogram, electrocardiogram, arterial blood pressure, respiratory and heart rates and serum cortisol) were monitored. The results showed that both drugs modified many behavioral reactions and physiological changes associated with administration of carbon monoxide. Acepromazine and pentazocine reduced by 25% and 20% respectively the number of dogs that showed vocalization and agitation. In acepromazine premedicated dogs, the duration of these signs was significantly diminished and sphincter relaxation did not occur in more than 50% of cases. Furthermore, with the use of acepromazine, no significant peaks or drastic drops were noticed in the heart and respiratory rates and in the arterial blood pressure. These manifestations are usually related to stress. In light of these results, it is recommended to premedicate dogs with acepromazine before submitting them to euthanasia by carbon monoxide inhalation.

Acepromazine↗
PubMed1985

Evaluation of the arterial blood pressure of dogs by two noninvasive methods.

The determination of the arterial blood pressure was done on 12 healthy mixed breed dogs in both the anesthetized and the conscious state, to evaluate two instruments (Doppler flow detector and infrasonde D4000), in their ability to indirectly determine arterial blood pressure. The coefficients of variation were higher with indirect methods when compared with the results obtained by cannulation. These coefficients were lower with the Doppler flow detector. The correlation study showed that both apparatuses were reliable in most situations. The infrasonde D4000 was more accurate than the Doppler in the conscious animals. However the results showed a lack of precision in hypertensive conscious dogs. The diastolic arterial blood pressure was particularly precise in the case of the anesthetized hypotensive dogs. Its sensitivity allowed it to register muscle movement artifacts. The Doppler flow detector showed less variation and was particularly accurate in both anesthetized and conscious hypertensive dogs. Its sensitivity allowed artifact movement sounds to be detected. The Doppler should be used in quiet surroundings or earphones should be worn by the evaluator. Some form of restraint is needed with the use of both instruments. Even if the correlations with the direct arterial blood pressure values were better with the infrasonde D4000, greater variations were found in the individual readings. The Doppler instrument represents in the hands of the investigators a better instrument for routine monitoring of blood pressure in the dog.

Animals↗
PubMed1983

Physiologic and behavioral evaluation of CO euthanasia of adult dogs.

Pure CO was used to euthanatize 18 dogs. During the procedure, physiologic parameters: EEG, ECG, arterial blood pressure, heart rate, respiratory rate, and cortisol values were monitored. Behavioral manifestations were also noted. The EEG modifications indicated a cortical voltage increase followed by rapid cerebral death. Higher heart and respiratory rates during EEG modifications indicated stress, and arterial blood pressure decreased significantly (P = less than 0.05) at the same time. Serum cortisol values were already high before the euthanasia process. Based on these observations, a precise time could not be set for unconsciousness. A gray zone, during which vocalization and agitation occurred for approximately 20 to 25 s, was 3 to 8 s in 10 dogs. These behavioral manifestations could still occur in the conscious phase.

Animals↗
PubMed1981

[Cerebrospinal fluid composition in newborn piglets].

Cerebrospinal fluid composition has been studied in low and normal birthweight piglets. Values for urea, Ca, K, Cl and P did not differ between the two groups. However, glucose concentration was lower in low birthweight subjects and Mg and Na values were higher. Total leukocytes were also higher in low birthweight piglets. These differences may suggest that blood-brain-barrier is not at the same stage of maturation in low birthweight as in normal birthweight subjects.

Animals↗
PubMed1979

The effect of atropine on acetylcholine-induced depressor responses in adult domestic fowl.

In pentobarbital-anaesthetized, spontaneously breathing adult chickens, intravenous administration of acetylcholine, histamine and 5-HT produced a dose-related fall in carotid arterial pressure, rise in central venous pressure and highly variable effects on heart rate. Atropine at low doses (0.1 to 0.2 mg/kg) selectively antagnoized depressor-responses to acetylchline. The blockade persisted for 20 to 30 min. At medium doses (0.5 to 2 mg/kg) atropine strongly antagonized acetylcholine for 50 to 110 min, and also partially antagonized responses to 5-HT and histamine. At higher doses (6 mg/kg), atropine-induced cholinergic blockade persisted for 280 min. It also nonselectively and significantly blocked responses to histamine and 5-HT. Therefore, it is concluded that the effectiveness and persistence of cholinergic blockade in chickens depends upon the dose of atropine used. It seems to rule out the opinion that high doses of atropine are required for cholinergic blockade in chickens.

Acetylcholine↗
PubMed1974

Sleep and wakefulness in the housed pony under different dietary conditions.

For several weeks, three ponies kept in an environment with controlled light and temperature, were studied for behaviour (time spent in recumbency and time required to consume hay or oats) and for electrical activity of the brain (cortical and sub-cortical) during the night phase of the circadian rhythm. Recumbency was adopted by all the ponies for six or seven periods during the night. With a regimen of hay ad libitum, about four hours were cumulated in sternal recumbency and only one hour in complete lateral recumbency. Various degree of sleep, as identified by cortical and hippocampal electrical activities, accounted for 30% of the circadian cycle. Paradoxical sleep was calculated to occur during 7% of the 24 hours. When oats were substituted for hay or during fasting for two to five days, the total recumbency time and the total sleep time (slow wave sleep and paradoxical sleep) increased. The time in lateral recumbency did not change.

Animal Feed↗
PubMedDate not supplied

Peripheral nerve sheath tumor of the diaphragm with osseous differentiation in a one-year-old dog.

A 12-month-old, spayed female German shepherd dog was referred to the Veterinary Teaching Hospital for repair of a diaphragmatic hernia. Abdominal exploration revealed an intact diaphragm, but thoracic exploration revealed a large mass originating from the diaphragm. Resection of the mass was incomplete and required reconstruction of the diaphragm. On histopathology, the mass was composed mainly of spindle-shaped cells with occasional areas of osseous and chondroid tissue. The tumor was diagnosed as a peripheral nerve sheath tumor (PNST) with chondro-osseous differentiation. The dog was released four days after surgery; however, she began having difficulty breathing seven days after discharge, and the owners elected euthanasia. A necropsy was not performed. This is the first known report of a PNST originating in the diaphragm of a dog.

Animals↗