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Biomedical subjects

H Sinzinger

Publications and source records attributed to H Sinzinger.

At least 541 records · Page 30Linked to original sources
PubMed1981

Decreased prostacyclin sensitivity of human platelets after jogging and squash.

8 healthy male volunteers performed jogging (as an example of an aerobic metabolic condition) and squash (as an example of an intermittently anaerobic metabolic condition). The platelets sensitivity to prostacyclin (PGI2) decreased after jogging. After squash, a statistically significant (p 0,001) decrease in the sensitivity of the platelets could be seen. Our findings suggest that an early alteration of platelet sensitivity might play a key role in maintaining the hemostatic balance and could be of greater importance than the vascular wall PGI2-synthesis, as the sensitivity changes immediately, whereas the PGI2-formation change is a long-term process.

Adult↗
PubMed1981

Plasma concentrations of plbatelet-specific proteins in coronary artery disease.

The plasma concentrations of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) were measured in 100 patients with documented coronary artery disease (CAD) and in 40 controls. 18 patients had had coronary artery bypass surgery (CABS), 25 patients were on therapy with beta-blocking agents and 19 were treated with oral anticoagulants. 38 patients with CAD received neither CABS nor beta-blocking or anticoagulating drugs. The highest plasma concentrations of beta-TG and PF4 were found in the patient group without medical or surgical treatment (patients versus controls: p less 0.01). Patients with CABS showed beta-TG and PF4 levels within the normal range. Patients with beta-blocking agents also had lower beta-TG and PF4 values than the patient group without therapy (p less than 0.05). By contrast, patients on oral anticoagulation therapy presented with similar plasma concentrations of beta-TG and PF4 as untreated patients. Our data indicate that surgical or medical treatment with beta-blocking agents, but not with oral anticoagulants, may have some influence on platelet function in patients with CAD. beta-TG and PF4 radioimmunoassay may be a simple method to study platelet involvement in various diseases and to evaluate possible influences of medical of surgical treatment on in vivo platelet function.

Adrenergic beta-Antagonists↗
PubMed1981

Platelet microaggregates and release of endogenous prostacyclin during the initial phase of haemodialysis.

In six patients arterial blood samples were withdrawn during haemodialysis (HD) for the measurement of platelet microaggregates, platelet and leucocyte counts, pO2 and 6-oxo-PGF1 alpha (the stable metabolite of prostacyclin). During the initial phase of HD the plasma concentrations of 6-oxo-PGF1 alpha increased, indicating an increased release of endogenous prostacyclin. Coincidentally to this phenomenon, hypoxaemia, reduction in platelet and leucocyte counts, and an increase in number of platelet microaggregates could be observed. Since prostacyclin is able to resolve platelet aggregates, we interpret the increased prostacyclin release to be in part a self protection mechanism against embolisation of microaggregates released from the dialyser into lung and peripheral vascular systems.

6-Ketoprostaglandin F1 alpha↗
PubMed1981

[Effect of body weight reduction on platelet function and serum lipoproteins in obese children (author's transl)].

In 11 obese children aged 11,9 +/- 1,3 years total cholesterol (C), triglycerides (TG), HDL-C, LDL-C and apolipoprotein B (Apo B) were estimated in serum after 3 weeks of hypocaloric diet (800 kcal, kJ). In vitro platelet function was evaluated using the tests of ADP-induced aggregation and platelet sensitivity to prostacyclin. The in vivo platelet activity was judged by estimating plasma levels of beta-thromboglobuline (beta-TG) and platelet factor 4 (PF4). A mean weight loss of 5,7 +/- 1,8 kg was observed. Before diet, serum-C, TG and lipoprotein-C concentrations were found to be within the so called "normal range". After three weeks of diet we observed a significant decrease of total-C, which could be accounted for by a decline in the atherogenic LDL-C; furthermore Apo B levels significantly decreased. Concerning the tests of platelet function only for beta-TG and PF 4 a marked decline (to about 50% of the initial values) could be seen. These preliminary results and changes in the lipoprotein are discussed in connection with a possible reduction of the risk for the development of atherosclerotic lesions.

Adolescent↗
PubMed1980

[Prostacyclin as a protective factor for blood vessels].

Prostacyclin is a very unstable prostaglandin, which is continuously synthetized and released by blood vessels. It fulfills 2 main functions, namely strong inhibition of platelet aggregation and vasodilation. Thus it acts as an important defense mechanism of the vascular wall, which is directed against overwhelming platelet aggregation and against the development of atherosclerosis. Besides endogenous prostacyclin is an important antihypertensive factor. In several diseases, as diabetes mellitus, obliterative arteriopathy and haemolytic-uraemic syndrome, the reduced prostacyclin-synthesis is thought to be a key mechanism for the development of vascular lesions. On the other hand the haemorrhagic diathesis of uraemics is seen in connection with an increased vascular prostacyclin release. Synthetic prostacyclin is now under trial for therapy in peripheral obliterative arteriopathy and extracorporeal circulation, as haemodialysis and cardiopulmonary bypass.

Arteriosclerosis↗
PubMed1980

[Quantitative studies on reversible thrombocyte aggregation during exertion].

In 8 oarsmen aged 19 to 31 years a symptom-limited rectangular-progressive bicycle stress test has been conducted. Venous blood was taken before and at the end of the test, and 30 and 60 minutes afterwards. pH, base excess, pCO2, platelet count and platelet count ratio (WU and HOAK) were measured or calculated, the last in order to quantify the tendency of the platelets to form reversible aggregates. At the point of exhaustion there is a highly significant (p < 0.001) decrease in the platelet cunt ratio (= increase in reversible platelet aggregates). A highly significant correlation exists between base excess and the platelet count ratio. The regression line does not fall below the normal value of the platelet count ratio until the delta-base excess is -4 mval/l. This means that an increase in the tendency to form reversible platelet aggregates is not typical of the range of aerobic metabolism but of muscular work in the anaerobic range with high exercise-induced metabolic acidosis. The basis for sudden death in sport due to internal reasons is not uncommonly an unknown and asymptomatic coronary disease and platelet aggregates. Persons aged over 30 years and sports in which competition is also inherent (soccer, tennis) are often involved. Acute cardiac death in sport is not very frequent. Nevertheless, the following recomendation seems to be warranted: persons aged over 30 years in bad condition should not start competitive sports or other intensive muscular exercise. Before they do so, low-intensive, controlled, aerobic endurance training is necessary.

Acidosis↗
PubMed1980

[Prostacyclin (PGI2) activity in the rectal mucosa of patients with ulcerative colitis (author's transl)].

PGI2 synthesis was investigated in rectal mucosa of 8 patients with active ulcerative colitis, 4 in remission and 16 controls. Determinations were carried out using Moncada's bioassay. The results demonstrated enhanced PGI2 synthesis in rectal mucosa in active ulcerative colitis. Further clinical studies should clarify whether or not selective inhibiton of PGI2 synthetase might be a useful therapeutic approach in ulcerative colitis.

Adolescent↗
PubMed1980

Is the variation in the susceptibility of various species to atherosclerosis due to inborn differences in prostacyclin (PGI2) formation.

Species exhibiting a higher susceptibility to the development of atherosclerosis have a reduced prostacyclin (PGI2)-generation in the arterial wall, which differs in various parts of the vascular system. As the difference in PGI2-formation in various diseases is a generalized vascular effect, the changes can be detected in all vessels. This is a very important point for diagnostic purposes in humans.

Age Factors↗