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Biomedical subjects

I Aursnes

Publications and source records attributed to I Aursnes.

At least 55 records · Page 3Linked to original sources
PubMed1988

Factor analysis of plasma lipoprotein components.

Serum phospholipids were analyzed for their content of long-chained fatty acids together with other components of lipoproteins (total- and HDL-cholesterol, apolipoproteins A-I and B, triglycerides), in 60 coronary heart disease patients and 30 control individuals. Some of the individual variations in content of the various components showed co-variation with each other. This formed the basis for the extraction of 7 'factors' by the statistical procedure 'factor analysis'. Analysis of variance was performed with the 'factor scores' for subgroups of high and low age and high and low total serum cholesterol. The analysis revealed two unexpected factors which discriminated with statistical significance between young, hypercholesterolaemic patients and controls. One factor was a positive risk factor and the other a negative one. They could possibly be dependent on the existence of two at present uncharacterized subgroups of lipoproteins. These lipoproteins contained, according to the analysis, large amounts of certain fatty acids. It is suggested that fatty acid analysis might be useful in the characterization of lipoproteins that are involved in the development of atherosclerosis.

Aged↗
PubMed1988

Correlation between plasma levels of selenium and antithrombin-III.

Patients with previous myocardial infarction were tested for antithrombin-III (AT-III) activity and selenium levels in their plasma and compared with sex- and age-matched healthy control individuals. Patients and controls showed a positive correlation between AT-III and selenium levels (r = 0.27, p = 0.015). After calculatory adjustment for this correlation, selenium was found to be significantly negatively correlated with disease. Multivariate analysis of differences between patients and controls indicated that triglyceride levels in serum had the greatest discriminatory ability (r2 = 0.169), followed by AT-III (r2 = 0.072) and selenium (r2 = 0.056). The increased AT-III levels were correlated with the use of warfarin and beta blockers in the patients, but these drugs could not explain the comparatively low selenium levels in the patients. Serum total cholesterol and plasma fatty acid composition had no discriminatory power in multivariate testing. The various fatty acid did not show co-variation with the selenium levels. The clinical significance of these observations is not clear, but they are consistent with the hypothesis that selenium is an important determinant in cardiovascular disease. The relation between AT-III and selenium should be further evaluated.

Antithrombin III↗
PubMed1988

Bacteriological findings and clinical symptoms in relation to clinical outcome in puerperal mastitis.

Clinical symptoms, bacterial content in breast milk and treatment were recorded in 43 women in Oslo with puerperal mastitis. Patients with a favorable (n = 35) and unfavorable outcome (n = 8) (defined as abscess formation and/or symptom relief after more than 7 days) were compared. The group with unfavorable outcome was characterized by increased delay between symptoms and time for consultation, higher score of clinical symptoms and higher frequency of Staphylococcus aureus. A higher frequency of S. aureus was found in the affected breasts than in the unaffected breasts. There was no difference concerning the frequency of coagulase-negative staphylococci and overall bacterial counts, either between milk from affected and non-affected breasts, or between milk from non-affected breasts and milk from healthy donors. The present investigation indicates that penicillin treatment is questionable when considering that untreated cases healed almost as quickly as treated ones, and that 70% of the S. aureus strains were resistant to phenoxymethylpenicillin. It is concluded that present bacterial examinations in breast milk are of limited help in deciding who needs antibiotic treatment.

Adult↗
PubMed1987

Shear stress activation of platelets with subsequent refractoriness.

Platelet rich plasma was prepared with soybean trypsin inhibitor (SBTI) as anticoagulant, to preserve normal Ca++-concentration, and subsequently tested in an aggregometer. Shear stress alone, induced by stirring, resulted in platelet aggregation and disaggregation. Such platelets showed only minor aggregational response on the addition of ADP, indicating that the platelets had been partly desensitized towards ADP-stimulation. When the stirrer was started at the same time as the addition of 1.6 microM ADP, the aggregation velocity was related to the speed of the stirrer. Disaggregation always started 1.5 min after the stimulus. Platelet shape change was apparently not influenced by the stirring. Since platelets from SBTI-anticoagulated blood could be aggregated by stirring alone, we examined the effect of centrifugation of whole blood at 50 xg for 3 and 10 min. Signs of transient aggregation and release of alpha-granule content were respectively observed.

Adenosine Diphosphate↗
PubMed1986

Low and high risk coronary patients discriminated by blood platelet fatty acid composition.

The distribution of 11 long-chain fatty acids in platelet phospholipids were subjected to multivariate statistical analysis with groups of high and low risk coronary patients and controls. The alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) had significant explanatory power between the groups. As has been anticipated from studies in Eskimos, the EPA fraction was low in coronary patients. It was lower in high risk patients than in low risk patients, and lower in patients below rather than above, 60 years of age. Young high risk patients had 1.2 +/- 0.2% (Mean, SE) EPA against 1.8 +/- 0.2% in young controls, (p = 0.035). Old low risk patients had the highest EPA and also the highest DHA, 2.9 +/- 0.3% against 2.3 +/- 0.2% in controls. The ALA was low in low risk patients. Patients with low platelet EPA and high serum cholesterol should be included in trials with EPA rich diets.

Aged↗
PubMed1984

On a possible interaction between ADP and mechanical stimulation in platelet activation.

Freshly drawn blood with inhibited plasma coagulation, but normal Ca++-concentration, was lightly centrifuged to produce platelet rich plasma (PRP). In order to minimize mixing of the various parts of the blood during the centrifugation, the red cells were centrifuged into a "cushion" of albumin in the bottom of the tube. Platelets harvested from the different parts of the centrifuge tube exhibited different degrees of activation, i.e. they possessed different abilities to aggregate when tested afterwards in an aggregometer. Complete ADP scavenging during the centrifugation inhibited the platelet activation, and it was therefore assumed that ADP released from red cells during the centrifugation was partly responsible for this. But as the ADP concentration at hand could be significantly reduced enzymatically without reducing the activation of the platelets by the centrifuge, mechanical stimulation during the centrifugation was postulated as a contributing factor. Prostaglandin synthesis inhibition during the centrifugation retarded the activation of the platelets in the tube.

Adenosine Diphosphate↗
PubMed1982

Preactivation and deactivation of blood platelets.

Human blood anticoagulated with a serine protease inhibitor was centrifuged with an erythrocyte agglutinating agent in the bottom of the tube. Platelet rich plasma (PRP) obtained in this manner contained platelets with different ability to aggregate with ADP located in the various layers of the tube. Platelets in the midportion of the tube were most extensively aggregated by a standard dose of ADP (1.6 micro M) and mechanical stirring. Platelets in the lowest portion aggregated least, but still showed normal "shape change" when they were stimulated. The uppermost platelets in the tube also showed somewhat reduced aggregation compared with the midportion. These observations could not be explained by differences in platelet concentrations. On a descriptive basis the platelets in the midportion of the tube are designated preactivated and the lowermost platelets deactivated.

Adenosine Diphosphate↗
PubMed1977

The haemostatic effect of 51CR-labelled blood platelets. An experimental study in the rabbit.

The haemostatic effect of 51Cr-labelled platelets was studied in 5 rabbits made thrombocytopenic (35,000/micronl blood) by whole body ionizing irradiation. Bleeding times were recorded after standardized cuts on the inner side of the rabbit's ear, a method with an acceptable reproducibility. The animals were then each transfused with concentrates of labelled platelets from 2 healthy donor rabbits. This increased the platelet counts to about 2 x 10(5)/micronl blood. Bleeding time values were markably prolonged before transfusion and became normalized when tested 1 and 4 h after transfusion. In 3 control experiments, where unlabelled platelet rich plasma was transfused to thrombocytopenic recipients, a similar shortening of the bleeding time was observed. It is concluded that 51Cr-labelled platelets retain haemostatic ability comparable to non-labelled platelets, when circulating in a recipient animal.

Animals↗