Biotechnologie in maatschappelijk perspectief

Political Scienc

Evaluation of a coagulation assay determining the activity state of factor VII in plasma

A coagulation assay is described that allows the measurement of the degree of activation of factor VII in circulating blood. The test is based on the use of both bovine and human brain thromboplastin, together with an artificial factor VII-deficient plasma. The latter can be prepared on a relatively large scale which makes it possible to measure factor VII activation in large series of patients. The determination of factor VII activation during incubation at 4 °C of plasma of women using oral contraceptives shows that the test described adequately measures factor VII activation. Differences in the time course of factor VII activation during this incubation in glass and plastic containers are found and implicate that rigorous standardization of blood sampling and test conditions is necessary. A possible mechanism that causes this critical dependence upon the test conditions is discussed

Onderwijs voor een kennissamenleving; de rol van ICT nader bekeken

Education; Information Technolog

Inhibition of activated factors II, VII, IX, and X by synthetic organic compounds directed against the active-site seryl residue

A series of 53 organic chemicals belonging to the groups of organic phosphates, sulfonyl derivatives and carbamates were screened for their activity against the coagulation factors IIa (thrombin), VIIa, IXa and Xa. Relatively specific inhibitors for the factors IIa, VIIa and Xa were found

The activity state of factor VII in plasma:Two pathways for the cold promoted activation of factor VII

The apparent amount of factor VII as determined in a one-stage test depends on the type of thromboplastin used: bovine thromboplastin only reacts with human factor VIIa whereas human thromboplastin interacts with unactivated human factor VII as well. Therefore the ratio factor VII activity as measured with bovine thromboplastin divided by the factor VII activity as assessed with human thromboplastin reflects the state of activation of factor VII in plasma. This approach was used to study the process of cold promoted factor VII activation and the involvement of different clotting factors therein. It could be shown that cold promoted activation does not occur in the absence of factors II and XII and is reduced for about 50% in factor IX deficient plasma. The other coagulation factors have a minor influence on the process. The results indicate that the cold promoted factor VII activation is the result of activation by both activated contact products and thrombin

In vitro cultivation of animal cells

ix+264hlm.;25c