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Biomedical subjects

A Arsenault

Publications and source records attributed to A Arsenault.

At least 19 recordsLinked to original sources
PubMed1992

Effect of coronary reperfusion on technetium-99m methoxyisobutylisonitrile uptake by viable and necrotic myocardium in the dog.

Technetium-99m hexakis-2-methoxyisobutyl isonitrile (99mTc-MIBI) distribution is flow-dependent, permitting the imaging of coronary perfusion defects. However, the behaviour of this tracer in viable and necrotic tissues within the ischaemic area at risk is still being debated. In a clinically relevant canine model, dogs were submitted either to a 24-h permanent occlusion (group 1) of the left descending coronary artery (LAD) or to a 90-min LAD occlusion followed by 22.5 h reperfusion (group 2). 99mTc-MIBI and radiolabelled microspheres were injected 3 h before sacrifice. After delimiting the area at risk and the infarct by Evans blue perfusion and triphenyltetrazolium chloride staining, heart slices were imaged by scintigraphy and tissue radioactivity measured in a gamma-counter. In the necrotic area of both groups, the 99mTc-MIBI distribution was proportional to the myocardial blood flow, approximating a 1:1 ratio (identity line slope 1, intercept 0) with highly significant correlation coefficients (group 1 r = 0.87, group 2 r = 0.86), whereas in the viable-ischaemic area of both groups, the data points are widespread above and below the identity line, indicating both over- and underestimations of blood flow in these tissue areas. These results were more pronounced following reperfusion as compared with permanent occlusion. Multiple linear regression analysis confirms differences (P less than 0.001) in 99mTc-MIBI distributions between the viable-ischaemic and the necrotic zones. Delineation of the ischaemic area at risk was possible only with permanent occlusion. A hypoperfused area was observed after reperfusion but differs from the anatomical infarcted area.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Lack of professional latitude and role problems as correlates of propensity to quit amongst nursing staff.

Which job stressors are the best predictors of propensity to quit among the nursing staff in emergency wards and intensive care units are explored in this paper. Employees of 30 Quebec hospitals (i.e. 60 wards in total) participated in the study (n = 1237). Stepwise multiple regression revealed that lack of professional latitude and role problems are the best predictors of the intention to quit the organization among all nursing staff. These two job stressors are briefly addressed in the context of intervention and possible remedies aiming at improving quality of life, mental health and decreasing the rate of turnover. It is argued that such intervention would benefit the nurses, the quality of patient care, as well as the respective hospitals.

Adult↗
PubMed1991

Technetium-99m sestamibi tomography in patients with spontaneous chest pain: correlations with clinical, electrocardiographic and angiographic findings.

The sensitivity and specificity of technetium-99m hexakis-2-methoxy-2-isobutyl-isonitrile (sestamibi) single-photon emission computed tomographic (SPECT) imaging for the diagnosis of coronary artery disease were studied in 45 patients admitted to the hospital for clinical suspicion of unstable angina. Only patients without prior myocardial infarction were included and all patients had technetium-99m sestamibi injection and a 12-lead electrocardiogram (ECG) during and less than or equal to 4 h after an episode of chest pain. Coronary angiography performed in all patients during hospitalization showed significant coronary artery disease (greater than or equal to 50% luminal diameter reduction) in 26 of the 45 patients. The SPECT studies obtained after injection of technetium-99m sestamibi during an episode of spontaneous chest pain showed a sensitivity of 96% for the detection of coronary artery disease; the 12-lead ECG obtained at the time of the injection had a sensitivity of 35%. With the patient in the pain-free state, respective sensitivity values were 65% and 38%. Specificity for the radionuclide study was 79% during pain and 84% in the pain-free state; for the ECG, it was 74% both during and between episodes of pain. The site of the perfusion defect corresponded to the most severe coronary artery lesion in 88% of patients. The severity of the perfusion defect correlated with the extent of coronary artery disease: the defect score was 5.3 +/- 3.3 with one-vessel disease, 4.9 +/- 2.8 with two-vessel disease and 10.5 +/- 5.0 with three-vessel disease (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

Gastrointestinal microbleeding after aspirin and naproxen.

Gastrointestinal bleeding is the most serious side effect encountered with the anti-inflammatory antirheumatic drugs. Using the 51Cr labeling technique, the comparative quantity of blood loss with aspirin or naproxen has been previously done on normal volunteers. With the present study, 12 rheumatoid arthritic patients were controlled in a double-blind crossover study with the same radioactive technique. There is a difference in favor of naproxen. The difference between the baseline period and naproxen administration was not statistically significant.

Adult↗
PubMed1978

[Communication].

Explore the source record for details and available documents.

Periodicals as Topic↗
PubMed1976

The influence of vesical distension on the urethral resistance to flow: a possible role for prostaglandins?

The possible role of prostaglandins in the mediation and/or modulation of the urethral response to vesical distension was investigated in female dogs. Three criteria for the possible involvement of these mediators have been investigated. Indomethacin could block the reduction of urethral resistance observed during vesical distension. Intra-arterial infusion of exogenous prostaglandin E2 resulted in a dose-dependent reduction in the urethral resistance to flow. Moreover, a significant release of prostaglandin E2 in the venous blood during the course of vesical distension could be demonstrated. The functional significance, mechanisms of release and mode of action of these highly active lipids are discussed.

Animals↗
PubMed1976

Gastro-intestinal microbleeding under acetylsalicylic acid, ketoprofen and placebo.

A quantitative comparison of gastro-intestinal microbleeding induced by acetylsalicylic acid (ASA), 3.6 g daily, ketoprofen (KETO), 200 mg daily and placebo (P) was undertaken in 12 normal volunteers using a double-blind factorial design with repeated measures. We conclude that KETO induces less gastro-intestinal bleeding than ASA but more than placebo and that there is a significant residual bleeding under placebo following ASA.

Anti-Inflammatory Agents↗
PubMed1976

Gastrointestinal microbleeding in normal subjects receiving acetylsalicylic acid, placebo, and R-803, a new antiinflammatory agent, in a design balanced for residual effects.

This study was undertaken to compare the relative gastrointestinal toxicity of equipotent doses of acetylsalicylic acid (ASA), 900 MG q.i.d., and a new anti-inflammatory agent, R-803, 300 mg q.i.d., against placebo. Gastrointestinal micro-bleeding was quantitated with the 61Cr-labeled erythrocyte assay. The experimental design was balanced for residual effects in the first week following any treatment. An interesting relationship between stool weight and blood loss was found to influence the microbleeding independently of the treatments themselves. All observed blood loss values were corrected by regression to a reference stool weight of 100 Gm. Final analysis of corrected values was done on arithmetic and logarithmic scales. On both scales, R-803 induced much less blood loss than ASA. A difference of 1.3 ml/day between R-803 and placebo was not statistically significant on the arithmetic scale. On the log scale, a statistically significant difference was found; but since it corresponds to 0.4 ml/day, it was not considered to be clinically significant at this dosage.

Anti-Inflammatory Agents↗
PubMed1976

[Effects of intrathoracic pressure on cerebral circulation in the monkey as a function of body posture, sitting or standing].

Sixty-four measurements of CBF were performed in 8 monkeys in supine and in sitting position under various conditions of ventilation. The position of the body does not normally influence the response of brain circulation to CO2. The response is not different from normal with high insufflation pressure in supine position and the capacities to autoregulation seem to be maintained. In vertical position however there are no longer any significant relations between CBF and PaCO2, and the loss of autoregulation seems to occur earlier and to be more marked. Correlation of these findings to neuroradiologic data indicates that the cerebral venous drainage through the meningospinal plexus is enhanced in vertical position and that during intrathoracic hyperpressure the cerebral venous blood is retained in the jugular vein and meningospinal plexus, thus decreasing the cerebral venous pressure increase and maintaining a perfusion of brain tissue compatible with the survival of the animal.

Animals↗
PubMed1976

Gastrointestinal blood loss induced by ketoprofen, aspirin and placebo (preliminary report).

In a 4-week double-blind multi-crossover trial 12 healthy volunteers received 1-week treatment with aspirin (3.6 g daily) and 1-week treatment with ketoprofen (200 mg daily). Before and after each active drug treatment the volunteers received 1-week of placebo treatment. The gastrointestinal blood loss was quantitatively determined by use of the radioactive chromiun (Cr51) technique. It is concluded that the gastrointestinal blood loss during the ketoprofen treatment was significantly less than during the aspirin period but significantly greater than during the placebo periods.

Adult↗
PubMed1975

Effect of naproxen on gastrointestinal microbleeding following acetylsalicylate medication.

This study was undertaken to determine if substitution of naproxen for ASA does influence salicylate-induced gastrointestinal bleeding. Twelve normal volunteers were selected and given increasing doses of salicylate until guaiac tests were consistently positive. Autologous labeling of their red blood cells with 51-Cr was used to quantitate the microbleeding. After two weeks on ASA, six subjects were double blindly switched to naproxen and six to placebo for another two weeks of observation. Two-way analysis of variance on the raw data shows a significant treatment effect associated with a significant interaction in both groups. Final analysis on a logarithmic scale permits orthogonal contrasts to be accurately made without any significant remaining interaction. It is concluded that substitution of naproxen for ASA at a dose of 500 mg daily is accompanied by a rapid reduction of microbleeding to "normal" levels.

Analysis of Variance↗