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Biomedical subjects

E G Vairel

Publications and source records attributed to E G Vairel.

16 recordsLinked to original sources
PubMed1994

[Biological activities of heparins, other than their antithrombotic action].

High and low molecular weight heparins are well known as antithrombotics. However they have some other interesting biological properties possibly usefull in the medical field. 1) They capture calcium ions. 2) They are very effective against vipers venom. 3) They increase the lipasemia, phenomenon acting secondarily on the calcemia. 4) Finally they are not only antithrombotic but have an activity increasing the physiologic pathway of fibrinolysis.

Animals↗
PubMed1989

[Low molecular weight heparins].

The apparition in the 80's of low molecular weight heparins (LMWHs) obtained by chemical or enzymatical splitting, modified the fields of prophylactic treatment of thromboembolic diseases. These drugs present on heparin numerous advantages: equal antithrombotic activity with a smaller bleeding risk, higher bioavailability, longer pharmacokinetic, which simplify their use. The definite mode of action remains unknown, but LMWH act at different steps like coagulation (by AT III), fibrinolysis, blood cells, endothelial cells. Further, like heparin, they can be neutralized by protamine. However the right, simple, specific biological assay which presents a good correlation with the antithrombotic activity, remained to be established.

Heparin, Low-Molecular-Weight↗
PubMed1983

Heparin and a low molecular weight fraction enhances thrombolysis and by this pathway exercises a protective effect against thrombosis.

In human volunteers unfractionated heparin and a low molecular weight fraction of heparin (LMWH) caused an increase in plasma plasminogen activator (PA) which peaked at 3 hours after subcutaneous injection. Using a perfused isolated rabbit ear model the enhancement of PA activity was confirmed and was related to the anti-Xa activity of both products infused. Using a modified rabbit Wessler model for thrombus formation it was found that, when using doses of heparin and LMWH sufficient to give a 100% antithrombotic effect, antifibrinolytic drugs (eg. epsilon-ACA and aprotinin), negated this protective effect. It is concluded that the effect of heparin and LMWH on haemostasis is mediated in part through the enhancement which these drugs have on fibrinolysis, the latter being arguably a major defence against fibrin formation during thrombosis.

Animals↗