... season – winter, spring, summer and autumn – the mean prothrombin time reported as an international normalised ratio (INR) and the percentages of INR below 2.0 and above 4.0 were calculated. Significant seasonal variations in mean INR measurements were found, with the lowest values in summer...

...Ingebrigt Talstad The calibration of prothrombin time (PT) assays was studied. A simple calibration between pooled normal plasma and pooled stable plasma was as satisfactory as more complex calibration methods based on linear or orthogonal regression between log clotting times of abnormal...

...Ingebrigt Talstad; Knut Korsbrekke An analysis of prothrombin time (PT) standardization methods is presented. The present recommended ratio method demonstrated complex calibration and wide therapeutic ranges. Standardization by coagulation activities resulted in different therapeutic ranges due...

...Ingebrigt Talstad Coagulation factors that interfere with the one-stage prothrombin time (PT) were investigated. PT responded with identical activities (adequately) against coagulation factors VII or X, only half as expected against factor IX, less than expected and nonlinearly against factor II...

...G. Baele; T. Fiers; G. Leroux-Roels Thrombotest® results expressed in international normalized ratio (INR) values, obtained in 108 patients on oral anticoagulant treatment, were compared with prothrombin time (PT) results with a recombinant thromboplastin. The former results were obtained...

...Ingebrigt Talstad The standardization of prothrombin time (PT) assays needs two steps: (1) calibration of PT assays towards a reference assay or reference thromboplastin, (2) correction of PT assays according to the calibration. The present recommended calibration by clotting times is favored...

... and antithrombin III, one-stage prothrombin time, factors VII and X and some biochemical tests reflecting liver cell damage were also stated. The obtained data indicate that plasma protein C level may constitute a useful marker of hepatocellular disease in alcoholics. © 1992 S. Karger AG, Basel 1992 Copyright...

...A.M.H.P. van.den.Besselaar Precision is defined as the agreement between replicate analyses of the same material. Within-laboratory precision of the prothrombin time (PT) and INR can be optimized by choosing an appropriate combination of thromboplastin and instrument. Accuracy (true value...

... vitamin K content is effective in increasing the percentage of tests within the therapeutic range in patients with poorly controlled anticoagulation. Vitamin K Diet Oral anticoagulants International normalized ratio Prothrombin time 19 10 1992 20 01 1993 28 4 2009 © 1993 S...

...Knut Korsbrekke; Ingebrigt Talstad The revised ratio method which is recommended for standardization of the one-stage prothrombin time, presumes that identical regression lines exist between clotting times of abnormal and normal plasma. A modification is proposed which corrects for possible...

..., instructions or products referred to in the content or advertisements. Blood coagulation tests Liver function tests Prothrombin time Warfarin Pivka inhibitor Haemostasis 15: 304-309 (1985) © 1985 S. Karger AG, Basel 0 3 0 1- 0 14 7 /8 5 /0 155-0304S2.75/0 How Does the Pivka Inhibitor Interfere...

...Ingebrigt Talstad An analysis of the one-stage prothrombin time using thromboplastins highly (Thrombotest®) and slightly (Normotest®) sensitive to the Pivka (protein induced by vitamin K absence) inhibitor is presented. A one-tenth dilution of blood with 0.1 mol/l Na 3 citrate was satisfactory even...

...H.J. Hassan; P. Casalbore; A. De Laurenzi; N. Petti; L. Sinibaldi°; M. Orlando A case of factor VII deficiency in a 52-year-old woman who developed central nervous system hemorrhage is here reported. Screening coagulation tests were all normal except for prothrombin time, normotest and thrombotest...

...M. Fujii; K. Yasunaga; H. Uchino Relationships between Normotest, prothrombin time, albumin, γ-globulin, GPT, and the hepatic fractional clearance of 198 Au-colloids as a measure of effective hepatic blood flow were studied by correlation analysis, in 50 patients with liver diseases, including...

...F. Panicucci; A. Sagripanti; B. Conte; E. Pinori; M. Vispi; L. Lecchini Factor IX activity (IX:C) and antigen (IX:Ag) as well as factor VII, prothrombin time, Normotest and Thrombotest were determined in 37 haemophiüacs B from 26 kindreds, in 30 carriers of haemophilia B and in 40 healthy subjects...

... the control group was given tap water, the animals in the cadmium group were treated with 15 ppm CdCl 2 for 4 weeks. Blood cadmium concentration, prothrombin time, activated partial thromboplastin time, plasma protein C and antithrombin activity, and platelet count were determined in the rats. Blood cadmium...

...M. Vacas; M.J. Aguirrebeitia; P.J. Lafuente; I. Unanue; J.A. Iriarte Prothrombin time (PT) is the control test for oral anticoagulant therapy as well as the screening test for defects of the extrinsic pathway of coagulation. Its responsiveness to decreased extrinsic clotting factors depends...

...M. Vacas; M.A. Fernández; F. Martínez-Brotons; P.J. Lafuente; F. Ripoll; C. Alvarez; J.A. Iriarte The aim of this study was to evaluate the accuracy of the portable coagulometer CoaguChek ® (Roche Diagnostics) as a prothrombin time (PT) monitor, and to correlate capillary blood results with those...

...Ingebrigt Talstad The standardization of prothrombin time (PT) has been a problem for more than 50 years; by applying the methods to the same clinical material the analysis may explain why. The initial standardization by 2–3 times normal clotting time by Quick’s PT assay did not standardize...

...M. Vacas; P.J. Lafuente; S. Cuesta; J.A. Iriarte Self-testing of oral anticoagulation is a new possibility related to the development of portable capillary whole blood prothrombin time monitors. The aim of this study was to evaluate one of this monitors, Coaguchek ® , with respect to its...