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Biomedical subjects

H Aström

Publications and source records attributed to H Aström.

At least 73 records · Page 4Linked to original sources
PubMed1977

Haemodynamic effects of different beta blockers in angina pectoris.

Beta-blocking agents with partial agonist activity seem to reduce heart rate at rest slightly less than those without this property. Cardio-selective drugs have no effect on stroke volume at rest contrary to the non-selective ones which will reduce it somewhat. This difference is abolished during exercise. The only difference seen during work between different beta-blockers is the effect on the peripheral vascular resistance. The selective drugs lower the arterial pressure with unchanged resistance.

Adrenergic beta-Antagonists↗
PubMed1977

The effect of beta-receptor-stimulating agents on the utero-placental blood flow.

The influence of salbutamol, a beta-2-receptor-stimulating agent, on the blood flow through the utero-placental unit was evaluated in the human. Serial placenta scintigrams were analysed quantitatively, after injection of 0.5 mCi Indium-113m, by means of a gamma-camera connected on line to a computer. The examinations were performed in the third trimester of pregnancy. No sedation was used. Uterine contractions were not present. Salbutamol caused an increase in activity over the placental region, corresponding to a 15% increase in blood volume. The rise time of the initial phase of isotope accumulation (calculated from 5 to 95% of final activity) was prolonged by 100% during salbutamol infusion. As the rise time is proportional to the volume/flow ratio of blood in the uteroplacental region, our data indicate that salbutamol infusion causes a decrease in blood flow in the absence of uterine contractions.

Albuterol↗
PubMed1976

Effect of long-term anti-hypertensive beta-receptor-blocking treatment on haemodynamic and metabolic responses to prolonged exercise in man.

1. Central and regional haemodynamics and leg metabolism at rest, during and after a prolonged exercise were studied in seven untreated hypertensive males before and after a long-term treatment (6 weeks) with an unselective beta-receptor-blocking drug (alprenolol). 2. Alprenolol treatment (200-400 mg, twice daily) decreased arterial blood pressure at rest and during exercise; it reduced heart rate in relation to drug plasma concentrations during and after exercise; it left cardiac output unchanged; it reduced leg blood flow at rest, but had no effect on leg blood flow during exercise. 3. Alprenolol treatment also decreased lipolysis and lactate release in relation to drug plasma concentrations during exercise.

Adult↗
PubMed1976

Design of exercise test, with special reference to heart patients.

Estimation of exercise tolerance in patients with heart disease and significant symptoms can usually not be expressed in terms of maximal oxygen uptake or power at a fixed heart rate calculated from a 'steady state' exercise test. The exercise tolerance can be expressed only by the maximal power developed, when limited by symptoms. For this purpose the level of tolerance is better assessed by a test with small increments and short duration of each work load. In clinical practice this type of almost continuous increase in load was found to be particularly useful in patients with ischaemic heart disease. Comparative studies showed that the work per heart beat at equal loads is significantly higher in the test with continuous increase in load than in the test with steps of 6 minutes duration, both in normal subjects and in heart patients. The difference, however, is small (7%) and for practical purposes these tests have equal validity as a measure of the circulatory capacity.

Adult↗
PubMed1975

Comparison of the effects on airway conductance of a new selective beta-adrenergic blocking drug, atenolol, and propranolol in asthmatic subjects.

Five patients with mild to moderate asthma were studied after an intravenous saline control followed by atenolol (i.v. 7-9mg) and propranolol (i.v. 0.2-1.0 mg) in a body plethysmograph. Following propranolol, heart rate did not change but specific airway conductance dropped with 65% and airway resistance increased with 130%. Following atenolol, there was a dose-related decrease in heart rate (25% after 9 mg i.v.) and a slight but not significant tendency to a decrease in airway conductance on the highest doses. None of the patients experienced any change in symptoms after administration of atenolol but after propranolol two patients had worsened symptoms. It is concluded that, in contrast to propranolol, atenolol blocks the beta-receptors in the heart preferentially to those in the lungs, and thus could be given to patients with obstructive lung disease.

Aged↗
PubMedDate not supplied

A method for synthesis of an artificial ribonuclease.

5-Amino-2,9-dimethyl-1,10-phenanthroline-oligonucleotide conjugates have been synthesized. A 2'-O-methyl octaribonucleotide carrying a 2'-aminoethoxymethyl linker in a central position was produced. Reaction of the aminoneocuproine phenyl carbamate with the fully deprotected oligonucleotide in aqueous solution gave virtually quantitative conversion into the conjugate. Preliminary cleavage studies in presence of zinc ions show nuclease activity towards RNA targets.

Oligonucleotides↗