A Coagulation Disorder Due to a Factor Vii–like Defect

The Function of Factor VII

“…Thronibin formation was slower than norinal in the presence of tissue throniboplastin; but it was normal when the patient's blood was allowed to clot normally (i.e., without added thrombopiastinj. Similar findings have been reported by other authors (Frick and Hagen, 1953 ;Marciniakbwna, Krakowska, Bober and Safarzyliska, 1953;Hicks, 1955). The observation, therefore, that Factor VII accelerates prothrombin conversion in the presence of tissue extracts does not necessarily imply that it is conceriied with the normal conversion of prothrombin to thrombin.…”

The Behaviour of Coagulation Factors during Anticoagulant Therapy with Special Reference to the One‐Stage Test as an Index of Therapy

“…The first is called Factor VII in this paper because it has most of the properties originally ascribed to this factor by Koller, Loeliger and Duckcrt (1951) and the second is here called Prower-Stuart factor after the descriptions of Telfer, Demon and Wright (1956) and Hougie, Barrow and Graham (1957). Both of thcse factors are concerned in reactions with tissue throniboplastins but Factor VII plays no part in intrinsic blood coagulation (Hicks, 1955; Ackroyd, 1956;Bergsagel and Hougie, 1956; Pitney, 1958) whereas the Prower-Stuart factor is an essential component in the generation of blood throniboplastin (Telfer et al, 1956; Hougie et al, 1957) and has been shown not to be reduced early in anticoagulant therapy.Thc one-stage 'prothronibin' test of Quick (193 5 ) is relatively insensitive to changes in prothrombin (Biggs and Douglas, 1953a) and in patients receiving anticoagulant drugs, it gives a measure of the combined effects of Factor VII and Prower-Stuart factor. It does not measure the combined effects of the factors reduced which are concerned in thromboplastin generation, namely, Factor X, Christmas factor, Prower-Stuart factor and possibly others as yet undescribed, and it may well be that the therapeutic effects of these drugs depend upon the reduction of thromboplastic factors.…”

“…The first is called Factor VII in this paper because it has most of the properties originally ascribed to this factor by Koller, Loeliger and Duckcrt (1951) and the second is here called Prower-Stuart factor after the descriptions of Telfer, Demon and Wright (1956) and Hougie, Barrow and Graham (1957). Both of thcse factors are concerned in reactions with tissue throniboplastins but Factor VII plays no part in intrinsic blood coagulation (Hicks, 1955; Ackroyd, 1956;Bergsagel and Hougie, 1956; Pitney, 1958) whereas the Prower-Stuart factor is an essential component in the generation of blood throniboplastin (Telfer et al, 1956; Hougie et al, 1957) and has been shown not to be reduced early in anticoagulant therapy.…”

Electrophoretic Studies of the Prower Factor; a Blood Coagulation Factor which differs from Factor VII

“…It was concluded that the defect differed from any which had been previously described and the abnormality was referred to as the 'Prower defect', pending further investigation. The features by which the defect was dlfferentiated from Factor-VII deficiency were: (I) thromboplastin generation was abnormal using the patient's serum, whereas Factor VII is not required for thromboplastin generation (Hicks, 1955; Jurgens, 1955;Ackroyd, 1956), and ( 2 ) the patient's serum added to 'Dindevan plasma' shortened the one-stage prothrombin time of the Dindevan plasma, and, conversely, 'Dindevan serum' reduced the one-stage prothrombin time of the patient's plasma.Bergsagel (195 5 ) , using electrophoretically separated fractions, showed that the one-stage prothrombin time of the patient's (Prower) plasma was reduced by the addition to it of either the a-or the p-globulin fractions of normal serum. The thromboplastin defect, on the other hand, as shown by the abnormal thromboplastin-generation test, was partially corrected by the a-globulin fraction but not by the p-globulin fraction.…”

“…It was concluded that the defect differed from any which had been previously described and the abnormality was referred to as the 'Prower defect', pending further investigation. The features by which the defect was dlfferentiated from Factor-VII deficiency were: (I) thromboplastin generation was abnormal using the patient's serum, whereas Factor VII is not required for thromboplastin generation (Hicks, 1955; Jurgens, 1955;Ackroyd, 1956), and ( 2 ) the patient's serum added to 'Dindevan plasma' shortened the one-stage prothrombin time of the Dindevan plasma, and, conversely, 'Dindevan serum' reduced the one-stage prothrombin time of the patient's plasma.…”