The determination of antithrombin III. Comparison of six methods. Effect of oral contraceptive therapy

At III levels measured with six methods in 36 people: 10 healthy controls, 10 women taking a progestagen Lynestrenol and 16 women taking a combined oestrogen-progestagen contraceptive pill. The reproducibility and the sensitivity of these methods as well as the correlation between methods were studied. The Hensen and Loeliger technique had a poor reproducibility and the results obtained with the Howie technique were not in good correlation with those obtained with other methods, especially in the group taking oral contraceptives. The two amidolytic methods using chromogenic substrates were found to be very accurate for antithrombin III activity determination. The rocket immunoelectrophoresis was more accurate and more practical than the radial immunodiffusion. With all methods--except the one of Howie--the 10 women taking progestagen Lynestrenol and the 16 taking combined oestrogen-progestagen had a low AT III and differed significantly from the 10 normals tested. No difference was observed between women taking progestagen only or an oestrogen-progestagen combination.

The activation of plasma factor XIII with the snake venom enzymes ancrod and batroxobin marajoensis

The snake venom enzymes Ancrod and Batroxobin marajoensis are able to activate human plasma factor XIII as shown by the formation of the gamma-dimers. The concentration of gamma-dimers increases with the concentration of the activating enzymes. Factor XIII activated by Ancrod or Batroxobin marajoensis is, however, unable to catalyse the incorporation of the amine dansyl-cadaverine into casein. The partially activated factor XIII is therefore not demonstrable by means of the artificial test system. This factor XIII loses little activity and remains activable by thrombin.

Interaction study between phenprocoumon and flurbiprofen

The effects of flurbiprofen on various coagulation and haemostasis parameters were studied in 19 patients adequately anticoagulated on a fixed dose of phenprocoumon. Laboratory controls were performed 5 times at weekly intervals. Flurbiprofen 50 mg 3-times daily was given for 2 weeks after an initial control period of 2 weeks. The last control followed 1 week after cessation of flurbiprofen. All changes observed during the administration of flurbiprofen were quantitatively moderate; some reached statistical significance. The prothrombin time (%) Factor II and Factor X values fell; Factor II values remained unchanged. Factor IX values fell only in the first week on flurbiprofen and reached control values thereafter. Phenprocoumon concentration remained constant throughout. There was no change in spontaneous platelet aggregation. Although there was a slight, statistically significant increase in the Ivy bleeding time, it remained within the normal range. These findings suggest that the interference of flurbiprofen with oral anticoagulation is minimal and probably of no clinical relevance.

Implementation of a British computer system for laboratory data handling

This paper describes the development and implementation of a small real-time British computer system for the handling of patient and test result data in the chemical pathology laboratories of the King's Health District (Teaching). Work destined for subsequent reporting by the computer system is entered by continuous on-line teletype. Test result data from multichannel analyzers are input using an on-line trace reader. Cumulative reports are printed both by line printer at the central laboratory and by on-line teletypes at two peripheral hospital laboratories. In a working day over 4000 new items of data are generated and 300-500 reports printed. The use of a trace reader as an inputing device and the method of employing a high capacity disk to give both speed of operation and limited archive facility are discussed.