COMPARISON OF HUMAN AND RABBIT BRAIN THROMBOPLASTIN IN THE EVALUATION OF LIVER DISEASE

1987 ◽  
Author(s):  
S Kitchen ◽  
R G Malia ◽  
D R Triger ◽  
M Greaves ◽  
F E Preston
Keyword(s):  
Liver Disease ◽  
Prothrombin Time ◽  
Oral Anticoagulants ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Reference Laboratory ◽  
Factor V ◽  
Factor X ◽  
Time Data ◽  
Suitable Alternative

In the UK, rabbit brain thromboplastin has recently replaced human thromboplastin. Since the sensitivity of thromboplastin varies according to species of origin, and the calibration of thromboplastins is based entirely on samples from normal subjects and patients on oral anticoagulants, a separate assessment is required in patients with liver disease. We have compared prothrombin times and specific one stage assays of factors V, VII and X in plasma from 19 patients with establishe < liver disease using rabbit thromboplastin (Manchester reagent, MR) and human thromboplastin (Manchester comparative reagent, MCR). Both materials were kindly provided by the National (UK) Reference Laboratory for Anticoagulant Control. Three separate analyses were performed on the prothrombin time data viz clotting time, prolongation of prothrombin time compared with control and prothrombin ratio. All were significantly longer with MR (p 0.001, paired ‘t’ test) although correlation was goo< (r=0.95 in all instances).In the assay of factors V, VII and X no significant differences were obtained with the two thromboplastins and correlation was good over a range of abnormality (Ranges for MCR and MR respectively were Factor V:0.31-1.23u/ml and 0.32-1.I6u/ml, r=0.96; Factor VII:0.07-1.22u/ml and 0.07-1.17u/ml, r=0.97; Factor X;0.18-1.Olu/ml and 0.17-1.03u/ml, r=0.96. We conclude that in the investigation of the haemostatic defect associated with liver disease rabbit brain thromboplastin is a suitable alternative to human material.

An Assessment Of An Amidolytic Assay For Factor VII In The Laboratory Control Of Oral Anticoagulants

1981 ◽  
Author(s):  
A Bodzenta ◽  
Jean M Thomson ◽  
Z S Latallo
Keyword(s):  
Prothrombin Time ◽  
Oral Anticoagulant ◽  
Oral Anticoagulants ◽  
Factor Vii ◽  
Limiting Factor ◽  
Factor X ◽  
Present Evidence ◽  
Chromogenic Assay ◽  
Better Than

An amidolytic assay for factor VII, modified from the method of Seligsohn et al (1978), has been compared with the results of the prothrombin time using British Comparative Thromboplastin, Thronbotest and a clotting assay for factor VII. In ‘long-term’ oral anticoagulant administration agreement with the conventional methods was good and better than in our previous study when amidolytic assays for factors II and X respectively were studied (Latallo et al 1981). The method appeared to be reasonably specific for factor VII.On the present evidence the chromogenic assay for factor VII offers a limited but apparently dependable guide to dosage but it is elaborate to perform and difficult to standardise. The main limiting factor for its routine application is the need to prepare a purified factor X extract.

Self-Damping Mechanism in Blood Coagulation

1974 ◽  
Vol 32 (01) ◽  
pp. 057-064 ◽  
Author(s):  
Y Nemerson ◽  
S.A Silverberg ◽  
J Jesty
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Calcium Ions ◽  
Control Mechanism ◽  
Factor Vii ◽  
Damping Factor ◽  
Factor V ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Two Systems

SummaryTwo reactions of the extrinsic pathway of coagulation, the activations of Factor X and prothrombin, have been studied in purified systems and shown to be self-damping. Factor X was activated by the tissue factor - Factor VII complex, and prothrombin by two systems: the coagulant protein of Taipan venom, and the physiological complex of activated Factor X, Factor V, lipid, and calcium ions. In each case the yield of enzyme, activated Factor X or thrombin, is a function of the concentration of activator. These and other observations are considered as a basis for a control mechanism in coagulation.

The Effect of Several Tissue Thromboplastins on the Activation of the Abnormal Factor X (Factor X Friuli)

1972 ◽  
Vol 27 (03) ◽  
pp. 535-542 ◽  
Author(s):  
A Girolami ◽  
M Lazzarin ◽  
G Molaro
Keyword(s):  
Prothrombin Time ◽  
Rabbit Brain ◽  
Factor X ◽  
Dilution Curve ◽  
Human Origin ◽  
Rabbit Lung ◽  
Normal Ratio

SummaryThe effect of several tissue thromboplastins on the abnormal factor X (factor X Friuli) has been investigated.The prothrombin time varied between 33.6 and 69 sec. The prothrombin time percentile values (saline dilution curve and Quick’s formula for citrated plasma) varied between 6.6 and 22% and between 10.9 and 32.8%, respectively. The prothrombin time patient/normal ratio varied between 2.24 and 4.43.The factor X level varied between 3.5 and 20% of normal.Significant correlations were found to exist between the percentile factor X level and the prothrombin time in seconds, the percentile prothrombin time values and the prothrombin time patient/normal ratio. Thromboplastins of human origin yielded the lowest factor X values namely 5% thereby appearing to be practically “inert” with regard to the abnormal factor X. Thromboplastins obtained from rabbit lung on the contrary yielded the highest values, namely 15.3%. Thromboplastins obtained from simian or rabbit brain gave values intermediate between these two extremes.

Spectrophotometric Assays of Prothrombin in Plasma of Patients Using Oral Anticoagulants

1979 ◽  
Vol 42 (04) ◽  
pp. 1296-1305 ◽  
Author(s):  
R M Bertina ◽  
W van der Marel-van Nieuwkoop ◽  
E A Loeliger
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
Factor V ◽  
Anticoagulant Treatment ◽  
Factor Ii ◽  
K Deficiency

SummaryTwo spectrophotometric assays for prothrombin have been developed and compared with a one stage coagulant and an immunological assay. One of these assays (called the XAPC assay) uses a combination of factor Xa, phospholipid, Ca2+ and factor V as activator of prothrombin, and measures only normal prothrombin. The second (the ECAR assay) uses Echis carinatus venom as activator. This assay measures both normal prothrombin and PIVKA II (protein induced by vitamin K antagonists/absence). Combination of the results obtained by the XAPC and ECAR assays provides rapid and reliable information on the degree of “subcarboxylation” of prothrombin (oral anticoagulation, vitamin K deficiency).For patients on long term anticoagulant treatment the prothrombin time (Thrombotest) shows better correlation with the ratio prothrombin/prothrombin plus PIVKA II (XAPC/ ECAR) than with the factor II concentration. For patients starting the anticoagulant treatment there is no correlation between the Thrombotest time and the XAPC/ECAR ratio.It seems doubtful that (a) spectrophotometric factor II assay(s) will be as useful as the prothrombin time in the control of oral anticoagulation.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Letters to the Editor

PEDIATRICS ◽  
1957 ◽  
Vol 19 (6) ◽  
pp. 1151-1151
Author(s):  
ARMAND J. QUICK
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Factor Vii ◽  
Factor V ◽  
Letters To The Editor ◽  
Time Determination

I wish to call your attention to a matter concerning the article of Fresh et al., "Blood Prothrombin, Proconvertin and Proaccelerin in Normal Infancy: Questionable Relationships of Vitamin K" which appeared in Pediatrics (19:241, 1957). On page 248 the following statement occurs: "Notwithstanding the insufficiently substantiated claims of Quick et al., that the simple `prothrombin time' determination is uninfluenced by an excess of factor V or factor VII,...." I consider such a statement inexcusable. While they could have said that "we regard the claims to be insufficiently substantiated, etc.," they made their statement to appear as a fact, which is not justified.

scholarly journals The Thrombogram in Rare Inherited Coagulation Disorders: Its Relation to Clinical Bleeding

2002 ◽  
Vol 88 (10) ◽  
pp. 576-582 ◽  
Author(s):  
Raed Al Dieri ◽  
Flora Peyvandi ◽  
Elena Santagostino ◽  
Muriel Giansily ◽  
Pier Mannuccio Mannucci ◽  
...  
Keyword(s):  
Lag Time ◽  
Peak Height ◽  
Factor Vii ◽  
Clotting Factor ◽  
Severe Bleeding ◽  
Factor V ◽  
Bleeding Tendency ◽  
Factor X ◽  
Factor Xi ◽  
Factor Concentration

SummaryWe investigated the relation between clotting factor concentration, the parameters of the thrombin generation curve (the thrombogram) and the severity of clinically observed bleeding in patients with congenital deficiency of prothrombin (n = 21), factor V (n = 22), factor VII (n = 22), factor X (n = 10), factor XI (n = 7) and factor XII (n = 6). The parameters used were: area under the curve (endogenous thrombin potential, ETP), peak concentration of thrombin attained and lag time before manifest formation.Peak height and ETP varied linearly with the concentration of prothrombin. For the other factors these parameters hyperbolically approached to the 100% limit with increasing clotting factor concentration. Half normal ETP was seen at about the following concentrations: prothrombin (50%), factor V (1%), factor VII (2%), factor X (5%) and factor XI (1%). As a rule, the peak height was somewhat more sensitive to clotting factor decrease than the ETP was.In all the patients with severe bleeding symptoms the ETP was less than 20% of normal. Bleeding tendency was absent or mild in patients with an ETP of 30% or higher. This value (except for prothrombin) is already obtained at concentrations of clotting factor of 1%-2%, which corroborates the clinical observation that a severe bleeding tendency is only seen in severe clotting factor deficiencies (less than 1%). The one exception was a patient with factor VII deficiency and severe bleeding, who showed a normal ETP value, albeit with a decreased peak height and a prolonged lag-time.

Prothrombin Activation Is Increased among Asymptomatic Carriers of the Prothrombin G20210A and Factor V Arg506Gln Mutations

2000 ◽  
Vol 84 (09) ◽  
pp. 396-400 ◽  
Author(s):  
Steve Humphries ◽  
Belinda Smillie ◽  
Lily Li ◽  
Jacqueline Cooper ◽  
Samad Barzegar ◽  
...  
Keyword(s):  
Factor Viia ◽  
Conclusive Evidence ◽  
Factor Ix ◽  
Factor Vii ◽  
Prothrombin G20210a ◽  
Factor V ◽  
Factor X ◽  
Coagulation Proteins ◽  
Prothrombin Activation

SummaryThe risk of venous thrombosis is increased in individuals who carry specific genetic abnormalities in blood coagulation proteins. Among Caucasians, the prothrombin G20210A and factor V Arg506Gln (FV R506Q) mutations are the most prevalent defects identified to date. We evaluated their influence on markers of coagulation activation among participants in the Second Northwick Park Heart Study, which recruited healthy men (aged 50–61 years) from nine general medical practices in England and Wales. They were free of clinical vascular disease and malignancy at the time of recruitment. Genotypes for the two mutations were analyzed using microplate array diagonal gel electrophoresis, and coagulation markers (factor XIIa; activation peptides of factor IX, factor X, and prothrombin; fibrinopeptide A) were measured by immunoassay. Factor VII coagulant activity and factor VIIa levels were determined by a functional clotting assay. Among 1548 men genotyped for both mutations, 28 (1.8%) and 52 (3.4%) were heterozygous for prothrombin G20210A and FV R506Q, respectively. The only coagulation marker that was significantly associated with the two mutations was prothrombin activation fragment F1+2 [mean ± SD, 0.88 ± 0.32 nmol/L in men with prothrombin G20210A (p = 0.002) and 0.89 ± 0.30 in men with FV R506Q (p = 0.0001) versus 0.72 ± 0.24 among non-carriers for either mutation]. This data provides conclusive evidence that heterozygosity for the prothrombin G20210A as well as the FV R506Q mutations in the general population leads to an increased rate of prothrombin activation in vivo.

FACTOR II ACTIVATING ACTIVITY IN EXTRACTS OF TUMORAL NECROSIS FROM TWO MURINE BREAST ADENOCARCINOMAS

1987 ◽  
Author(s):  
A Blanco ◽  
R Bonfil ◽  
O Bustoabad ◽  
M Lazzari
Keyword(s):  
Coagulation Factors ◽  
Factor Vii ◽  
Factor V ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Factor Ii ◽  
Metastatic Capacity ◽  
Plasma Recalcification Time ◽  
Recalcification Time ◽  
Breast Adenocarcinomas

Increased deposition and lysis of fibrin, associated with malignant tissue, has led to look for activators of both the coagulation and fibrinolytic systems produced by tumor cells. We report the evidences of a procoagblant activity (PA) in the extracts of intratumoral necrosis from two experimental breast adenocarcinomas in murine model (BALB/c). The tumors have different metastatic capacity (MC). M3 without MC and MM3 with high MC.The addition of the extracts to: 1- Normal Plasma, 2- Deficient substrates in coagulation factors, 3- Purified, fibrinogen (I), showed: 1- Shortening of the plasma recalcification time (PRT) and APTT, without ;modification on prothrombin time (PT), 2- Reduction of the PRT on deficient substrates in factors: VIII; VII; VII and X; V; V, VII and X; without modification on II deficient substrate, 3- No PA on I. Table:C: Control, s: seconds, m: minutes. The PA was not affected by heparin. The results suggest that the PA is independent of the presence of either factor VIII or factor VII (intrinsic or extrinsic pathway respectively), as well as presence of either factor V or factor X. Any effect was observed either on factor II deficient substrate or on I, so, there was no evidence of thrombin activity The PA could be act directly on factor II, suggesting that fibrin formation could be induced by a “non-classical” activation pathway. No significant differences (p>0.5) in PA were observed between both tumoral necrosis extracts. The necrotic area in M3 (37%) is bigger than in MM3 (18%). So, much more PA could be present in MM3 and this could play a role in the MC of this tumor.

scholarly journals Coinheritance of Factor V (FV) Leiden enhances thrombin formation and is associated with a mild bleeding phenotype in patients homozygous for the FVII 9726+5G>A (FVII Lazio) mutation

Blood ◽  
2003 ◽  
Vol 102 (12) ◽  
pp. 4014-4020 ◽  
Author(s):  
Elisabetta Castoldi ◽  
José W. P. Govers-Riemslag ◽  
Mirko Pinotti ◽  
Debora Bindini ◽  
Guido Tans ◽  
...  
Keyword(s):  
Thrombin Generation ◽  
Clinical Phenotype ◽  
Activated Protein C ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Factor V ◽  
Factor X ◽  
Fv Leiden ◽  
Fvii Deficiency ◽  
Thrombin Formation

Abstract We investigated the role of thrombophilic mutations as possible modifiers of the clinical phenotype in severe factor VII (FVII) deficiency. Among 7 patients homozygous for a cross-reacting material-negative (CRM-) FVII defect (9726+5G&gt;A, FVII Lazio), the only asymptomatic individual carried FV Leiden. Differential modulation of FVII levels by intragenic polymorphisms was excluded by a FVII to factor X (FX) gene haplotype analysis. The coagulation efficiency in the FV Leiden carrier and a noncarrier was evaluated by measuring FXa, FVa, and thrombin generation after extrinsic activation of plasma in the absence and presence of activated protein C (APC). In both patients coagulation factor activation was much slower and resulted in significantly lower amounts of FXa and thrombin than in a normal control. However, more FXa and thrombin were formed in the plasma of the patient carrying FV Leiden than in the noncarrier, especially in the presence of APC. These results were confirmed in FV-FVII doubly deficient plasma reconstituted with purified normal FV or FV Leiden. The difference in thrombin generation between plasmas reconstituted with normal FV or FV Leiden gradually decreased at increasing FVII concentration. We conclude that coinheritance of FV Leiden increases thrombin formation and can improve the clinical phenotype in patients with severe FVII deficiency. (Blood. 2003;102:4014-4020)

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