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Biomedical subjects

A Pedersen

Publications and source records attributed to A Pedersen.

At least 109 records · Page 6Linked to original sources

Myocardial infarct size and cardiac performance at exercise soon after myocardial infarction.

Infarct size was estimated from serial serum CK MB measurements in a series of 101 patients admitted less than 15 hours after the first acute myocardial infarction. A maximal symptom limited exercise test comprising impedance measurements for the estimation of stroke volume at rest and at different levels of exercise was performed early after admission by 26 patients. There was a slight, though not significant, negative correlation between infarct size and physical capability as measured by the duration of work. The rise in systolic blood pressure during exercise showed a significantly negative and the increase in heart a significantly positive correlation to infarct size. This suggests that the rise in blood pressure, which is less in patients with the larger infarcts, is compensated by an increase in heart rate, so that the same maximum of cardiac performance and myocardial oxygen consumption is reached. The increase in cardiac stroke volume during exercise was negatively correlated with infarct size. Stroke volume only increased during lower levels of exercise; the increase in cardiac output at higher levels of exercise was achieved entirely by an increase in heart rate. The magnitude of ST segment elevation during exercise showed a significantly positive correlation with infarct size, whereas the occurrence of arrhythmias during exercise was independent of it.

Aged↗

Optimal diagnosis in acute myocardial infarction. A cost-effectiveness study.

The predictive value of a diagnostic test estimates the likelihood for presence or absence of disease in a patient with a positive or negative test result (PVpos or PVneg). We evaluated the predictive values of serum activities of the heart-specific creatine kinase isoenzyme MB (CK-MB), aspartate aminotransferase, lactate dehydrogenase, CK, and ECG in 401 consecutively admitted patients suspected of acute myocardial infarction (AMI). The study showed that CK-MB (PVpos = 0.98, PVneg = 1.00) was better than the other enzymes (single as well as serial) and ECG, evaluated both separately and in combinations. In all cases of AMI CK-MB was positive within 17 hours from admission. Replacement of the standard enzymes with CK-MB provides a faster and safer diagnosis of AMI and reduces hospitalization time considerably for patients without AMI.

Acute Disease↗

Plasma catecholamines, renin and aldosterone during combined alpha- and beta- adrenoceptor blockade in patients with severe arterial hypertension.

Arterial blood pressure and plasma catecholamines, renin activity and aldosterone concentration in 12 patients with severe essential hypertension were studied before and after combined alpha- and beta- adrenoceptor blockade induced by oral labetalol treatment for 2 months. Frusemide in a fixed dose was employed as a basic antihypertensive agent throughout the study. Blood pressure was adequately controlled in only 6 patients. Mean body weight increased by 1.8 kg and there was a rise in body weight which was inversely correlated with the fall in standing mean blood pressure. The mean plasma noradrenaline concentration decreased from 0.30 to 0.20 ng/ml, whereas plasma adrenaline did not change significantly. Plasma renin activity and aldosterone concentration varied greatly, but the mean values did not change significantly. Change in body weight was correlated inversely with changes in plasma noradrenaline and renin. The results suggest that labetalol, through its combined alpha- and beta- adrenoceptor blocking action, induces a rise in body weight, probably due to sodium and fluid retention, which partly counterbalances its anti-hypertensive effect and partly modifies both renin and sympathetic nervous activity.

Adult↗

Cardio-specific serum enzyme CK--MB following physical exercise in acute myocardial infarction.

The possible harmful effect of physical activity on the extent of myocardial damage in patients with fresh myocardial infarction (AMI) has been a matter of debate. In this paper, serial determinations of serum creatine kinase (CK) isoenzymes are presented from 20 unselected patients with AMI, in 14 of them complicated by congestive heart failure or/and significant rhythm disturbances. During the acute phase, the cardiospecific MB-isoenzyme of CK in all patients rose above the upper reference limit of 30 U/l, the peak values ranging from 39 to 741, and returned to normal range within a few days. During the third week a maximal, symptom-limited exercise test was performed, with renewed serial determinations of CK-isoenzymes. Following the exercise an ST-segment deviation in the ECG was noted in 14 patients, anginal pain in 4, and a significant rise in serum CK--MM activity in 9 patients, whereas the CK--MB isoenzyme remained at zero level in all 20 patients. Thus, no evidence was found that even a maximal physical effort during the third week after AMI did cause any myocardial damage.

Acute Disease↗

Experimental Ascaris suum infection in pigs. Serological response, eosinophilia in peripheral blood, occurrence of white spots in the liver and worm recovery from the intestine.

Experimental oral inoculation of pigs with infective A. suum eggs resulted in eosinophilia in the peripheral blood and a serum antibody response. When pigs were inoculated at 3 days of age the antibody response was depressed which is suggested to be due either to a protective effect of colostral antibodies or to an immunologic incompetence of the young pigs. Despite the use of isolated pens and strict hygienic measures it was difficult to obtain an Ascaris free environment for the experimental animals. The pathogenesis of white spots in the liver is assumed to represent an immune reaction by the host. Multiple white spots were demonstrated when pigs were inoculated with several egg doses provided the livers were examined 1--3 weeks after last inoculation. The rapid healing of white spots implies that the finding of many white spots in the liver at slaughter indicate a recent uptake of infective A. suum eggs. The finding of low intestinal worm burdens in the experimental pigs after repeated oral inoculations indicates a specific, acquired resistance. Resistance to A. suum in pigs is suggested to involve co-operation of the humoral and the cell mediated immune system and the parasite is eliminated both during migration by white spot formation in the liver and during the early prepatent period by expulsion from the gut.

Animals↗

Effect of oral labetalol on plasma catecholamines, renin and aldosterone in patients with severe arterial hypertension.

Arterial blood pressure and plasma catecholamines, renin activity and aldosterone concentration in 12 patients with severe essential hypertension were studied before and after combined alpha- and beta-adrenergic receptor blockage induced by oral labetalol treatment for 2 months. Furosemide in a fixed dose was employed as a basic antihypertensive agent throughout the study. Blood pressure was adequately controlled in only 6 patients. Mean body weight increased by 1.8 kg and there was a rise in body weight which was inversely correlated with the fall in standing mean blood pressure. The mean plasma noradrenaline concentration decreased from 0.30 to 0.20 ng/ml, whereas plasma adrenaline did not change significantly. Plasma renin activity and aldosterone concentration varied greatly, but the mean values did not change significantly. Change in body weight was correlated inversely with changes in plasma noradrenaline and renin. The results suggest that labetalol, through its combined alpha- and beta-adrenergic receptor blocking action, induces a rise in body weight, probably due to sodium and fluid retention, which partly counterbalances the antihypertensive effect of labetalol, and partly modifies both renin and sympathetic nervous activity.

Adult↗

Effect of propranolol on total exchangeable body potassium and total exchangeable body sodium in essential hypertension.

Total exchangeable body potassium (KE) was determined in fifteen patients with essential hypertension, and total exchangeable body sodium (NaE) in ten, before and after propranolol administration for 2-3 months. Blood pressure was reduced; serum potassium increased, but KE was unchanged. Serum sodium and NaE were unaffected during therapy. It is concluded that the increase in serum potassium during propranolol treatment could not be attributed to potassium retention, but is possibly due to a displacement from the intra- to the extracellular fluid compartment. The antihypertensive effect of propranolol could not be related to changes in NaE.

Adult↗

Clostridium botulinum in fish.

1407 fish caught in Scandinavian waters, the North Sea and the North Atlantic have been examined for the presence of Cl. botulinum. The incidence in gut samples expressed as percentage of fish tested was generally highest in fish from Scandinavian coastal waters and the Baltic Sea (4--43%), decreasing in fish from the North Sea (0--8%), and the organism was practically absent in fish from the North Atlantic. When gut samples were examined, the incidence was highest in demersal fish (cod and flatfish) as compared with pelagic fish (herring). The latter fish species were mainly contaminated on outer surfaces and gills. Only type E was detected in this survey, and Cl. botulinum was not detected in any wild fresh water fish. It is suggested that type E spores may originate in the sea bed and that they be spread by fish and water currents.

Animals↗

Cathepsin B activity in stimulated mouse peritoneal macrophages.

The activity of cathepsin B was assayed in murine resident peritoneal macrophages, and after stimulation of the cells in vivo and in vitro. The resident cells showed a very low activity of the enzyme, compared to the activities of three other lysosomal enzymes: cathepsin D, acid phosphatase, and beta-glucuronidase which were tested simultaneously. Endocytosis of carrageenan, latex, or carbon particles in vitro induced a prominent rise in intracellular cathepsin B activity. Addition of endotoxin from Escherichia coli in vivo or in vitro, or cell wall products from streptococci in vitro caused no change in cathepsin B activity. There was a release of enzyme activity to the medium after a 72-hour culture of macrophages. However, the release, calculated as a percentage of total activity, was not influenced by any treatments mentioned. All significant rises in enzyme activity could be inhibited by the addition of cycloheximide, and it was concluded that increased enzyme activity was dependent on new protein synthesis.

Acid Phosphatase↗