Assay of the Antifibrinolytic Activity in Human Plasma by Means of the Lysis Time Method

1968 ◽  
Vol 20 (03/04) ◽  
pp. 561-573 ◽  
Author(s):  
J Ygge ◽  
W Berg ◽  
K Korsan-Bengtsen
Keyword(s):  
Human Plasma ◽  
Present Report ◽  
Test System ◽  
Time System ◽  
One Stage ◽  
Lysis Time ◽  
Straight Line ◽  
Main Action

SummaryA one-stage lysis time method to determine the total antifibrinolytic activity of human plasma is described. Purified fibrinogen, thrombin, plasminogen, and urokinase were used in the test system. The necessity of using a high plasminogen concentration compared with the urokinase concentration is pointed out. The concentration of the reagents has to be carefully standardized.A straight line will be obtained in a semi-logarithmic system when plasma dilutions are plotted against. The validity of this relation is investigated when the concentrations of plasminogen, fibrinogen, and urokinase are varied. It is also shown that this relation is valied when the antifibrinolytic activity is increased postoperatively and after delivery.The antifibrinolytic activity is expressed as a percentage of the activity of a standard plasma. The standard plasma does not change its antifibrinolytic activity during storage at —20° C for at least three months.The error of the method is about 2%.Finally, the present report includes an experiment, the result of which makes it probable that the main action of plasma tested in this one-stage lysis time system is an antiplasmin activity.

Determination of Plasminogen in Human Plasma by the Lysis Time Method

1966 ◽  
Vol 16 (01/02) ◽  
pp. 001-017 ◽  
Author(s):  
W Berg ◽  
K Korsan-Bengtsen ◽  
J Ygge
Keyword(s):  
Human Plasma ◽  
Present Method ◽  
Blood Donors ◽  
Fibrinogen Concentration ◽  
Plasmin Activity ◽  
Time System ◽  
Lysis Time ◽  
High Dilutions ◽  
Single Determination

SummaryA one-stage lysis time system containing fibrinogen, streptokinase, thrombin, and a known, small amount of plasminogen was used to determine plasminogen in plasma.The known amount of plasminogen was added to the system in order to keep the lysis times relatively short when a highly diluted plasma was tested. High dilutions of plasma were used to reduce the influence of the plasma inhibitors.The calculation of the plasminogen concentration was made on the basis of the correlation: “plasminogen = fibrinogen/lysis time” which was valid in the system. The method allowed determination of plasminogen in plasma with varying fibrinogen concentrations, as the fibrinogen concentration in plasma was considered in the calculation.The presence of “spontaneous” plasmin activity in the plasma did not influence the plasminogen determination. Estimated by this method, the plasminogen content in plasma from 32 blood donors aged 25-45 years was 13.1 ±2.4 casein u/ml. The error of a single determination was 0.3 casein u/ml. The plasminogen content in plasma, determined with the present method, is about 3-4 times higher than the content found when a caseinolytic method is used.

Performances of an Artificial Reagent for the One-stage Factor IX Assay

1975 ◽  
Vol 33 (03) ◽  
pp. 547-552 ◽  
Author(s):  
L Meunier ◽  
J. P Allain ◽  
D Frommel
Keyword(s):  
Human Plasma ◽  
Factor Ix ◽  
Severe Haemophilia ◽  
Normal Human Plasma ◽  
Haemophilia B ◽  
One Stage ◽  
Normal Human ◽  
The One

SummaryA mixture of adsorbed normal human plasma and chicken plasma was prepared as reagent for factor IX measurement using a one-stage method. The substrate was found to be specific for factor IX. Its performances tested on samples displaying factor IX activity ranging from <l%–2,500% compared favorably with those obtained when using the plasma of severe haemophilia B patients as substrate.

Distinction of Plasma Inhibitor of Activator-Induced Clot Lysis from Antiplasmins

1975 ◽  
Author(s):  
N. Aoki ◽  
M. Matsuda ◽  
M. Moroi ◽  
N. Yoshida
Keyword(s):  
Affinity Chromatography ◽  
Human Plasma ◽  
Gel Filtration ◽  
Plasminogen Activators ◽  
Inhibitory Effect ◽  
Clot Lysis ◽  
Plasminogen Activation ◽  
Lysis Time ◽  
Α2 Macroglobulin ◽  
Clot Lysis Time

A fraction of human plasma prolongs the activator-induced clot lysis time and inhibits plasminogen activation by the plasminogen activators derived from various sources (urine and tissues). This fraction, designated as antiactivator fraction, was separatid from antiplasmin fractions (α2-macroglobulin and α1-antitrypsin) by gel filtration and affinity chromatography on Sepharose coupled with IgG of antiserum to α1-antitrypsin. Anti-activator fraction thus obtained exerted little antiplasmin activity but inhibited strongly activator-induced clot lysis.Inhibitory effect of plasma on urokinase-induced clot lysis (antiactivator activity) was assayed in various diseases and compared with antiplasmin activity. No correlation was found between the two activities, and it was concluded that the two activities are independent and are ascribed to two different entities.

Evaluation of N8-GP Activity Using a One-Stage Clotting Assay: A Single-Center Experience

2019 ◽  
Vol 143 (5) ◽  
pp. 504-508 ◽  
Author(s):  
Inga Hegemann ◽  
Karin Koch ◽  
Wan Hui Ong Clausen ◽  
Mirella Ezban ◽  
Brigitte Brand-Staufer
Keyword(s):  
Human Plasma ◽  
One Stage ◽  
Single Center Experience ◽  
Fviii Activity ◽  
Previously Treated Patients ◽  
Normal Human ◽  
Previously Treated ◽  
Aptt Reagent ◽  
Few Data ◽  
Good Agreement

N8-GP (ESPEROCT®; turoctocog alfa pegol; Novo Nordisk A/S, Bagsvaerd, Denmark) is an extended half-life recombinant factor VIII (FVIII) molecule. FVIII-deficient plasma spiked with N8-GP can be accurately measured using many activated partial thromboplastin time (aPTT)-based one-stage clotting assay reagents with normal human plasma calibrators. To date, there are few data on the measurement accuracy of samples from patients treated with N8-GP. Here, we measure patient samples during routine treatment monitoring. Three previously treated patients with severe hemophilia A (HA) without inhibitors (baseline FVIII activity <0.01 IU/mL) received 50 IU/kg N8-GP every fourth day or twice weekly over 5 years as part of the pathfinder2 trial. Patient samples were monitored using the Pathromtin® SL aPTT reagent (Siemens Healthcare GmbH, Erlangen, Germany), a BCS® XP System analyzer (Siemens), and Standard Human Plasma (Siemens) or product-specific calibrators. Patient age ranged from 36 to 62 years. Overall, measurements performed using product-specific or Standard Human Plasma calibrators were in good agreement, with ratios randomly distributed around 1.0. Peak ratios tended to be closer to 1.0 than trough samples. Pathromtin® SL with Standard Human Plasma calibrator consistently and accurately measured FVIII activity in samples from severe HA patients receiving N8-GP prophylaxis.

The Compass Time System and its Interoperation

2012 ◽  
Vol 239-240 ◽  
pp. 548-551
Author(s):  
Shao Wu Dong
Keyword(s):  
Atomic Clock ◽  
Test System ◽  
Ground Control ◽  
Time System ◽  
Satellite Navigation System ◽  
System A ◽  
Timing System ◽  
Control Centre ◽  
Navigation Test ◽  
Atomic Time

We report on the time reference system of Compass global satellite navigation system and its interoperation with other GNSS’s. China has sent three satellites into geostationary orbit since 2000, and Compass Navigation Test System has been established. Compass time reference, named as BDT, is based on Atomic time, BDT is derived from the atomic clock ensemble in Compass ground control centre, and be traced to the international time, UTC. Interoperability is one of the most important aspect in the design of Compass timing system, a solution of time differences determination among BDT and other GNSS time scales are introduced in this paper.

AN INSULIN ASSAY BASED ON THE INCORPORATION OF LABELLED GLYCINE INTO PROTEIN OF ISOLATED RAT DIAPHRAGM

1959 ◽  
Vol 19 (3) ◽  
pp. 259-262 ◽  
Author(s):  
K. L. MANCHESTER ◽  
P. J. RANDLE ◽  
F. G. YOUNG
Keyword(s):  
Human Plasma ◽  
Plasma Samples ◽  
Rat Diaphragm ◽  
Normal Human Plasma ◽  
Advantages And Disadvantages ◽  
Straight Line ◽  
Normal Human ◽  
Isolated Rat

SUMMARY Insulin increases the incorporation of [14C]glycine into the protein of isolated rat diaphragm in vitro. This effect of the hormone can be used as the basis of a straight-line assay for insulin. The advantages and disadvantages of such a method of assay are discussed. Normal human plasma also stimulates incorporation of glycine into diaphragm protein, and the activities of two plasma samples were equivalent to 2 and 10 mu. insulin/ml. plasma, respectively.

The Influence of Thrombin on the Clotting Activity of Factor VIII. A Study with Insolubilized Thrombin

1978 ◽  
Vol 39 (03) ◽  
pp. 600-606 ◽  
Author(s):  
Th Vukovich ◽  
E Koller ◽  
W Doleschel
Keyword(s):  
Factor Viii ◽  
Test Sample ◽  
Test System ◽  
Factor Viii Activity ◽  
Two Stage ◽  
One Stage ◽  
Analytical Procedures ◽  
The One

SummaryAn investigation of the influence of thrombin on the clotting activity of factor VIII was made. Purified factor VIII and different amounts of thrombin complexed to Sepharose 4 B were mixed and incubated for various periods of time. The factor VIII activities of these incubation mixtures were determined by the one- and two-stage analytical procedures in the presence of the thrombin-sepharose and in its absence following the latter removal from the test sample by filtration. The results so obtained confirm the view that thrombin inactivates factor VIII. Evidences for a thrombin-induced potentiation of the factor VIII activity, seen only in the thrombin-sepharose containing test samples analyzed by the one-stage method, are here interpreted as thrombin-effects peculiar to this factor VIII test system and not as potentiation by thrombin of the factor itself.

Inhibition of Clotting as the Result of Plasminogen Activation by Streptokinase

1960 ◽  
Vol 04 (03) ◽  
pp. 507-519 ◽  
Author(s):  
P Glas ◽  
F. K Beller
Keyword(s):  
Human Plasma ◽  
Plasma Source ◽  
The Other ◽  
Plasminogen Activation ◽  
Human Fibrinogen ◽  
Lysis Time ◽  
The One

SummarySamples of an activation mixture, consisting of fibrinogen, streptokinase and plasma (source of pro-activator) were added to thrombin at intervals of 1 minute and subjected to lysis time determinations; the absence of clotting was noted after a certain period of incubation. At this point, the lysis time was no longer measurable.Inhibition of coagulation was not observed if either bovine fibrinogen or human plasma were incubated with streptokinase alone. If, however, human fibrinogen was used instead of bovine fibrinogen, this effect occurred even if only fibrinogen and streptokinase were incubated.The mechanism of the process described was investigated by varying the different streptokinase- and fibrinogen concentrations, using either undiluted or diluted plasma.It was evident that there is a relationship between the concentrations of fibrinogen and streptokinase on the one hand, and the degree of plasma dilution on the other.Fibrinogenolysis is caused by activation of the pro-enzyme contained in the fibrinogen preparations. During this process, fibrinogen is altered to a non-coagulable protein.

The in Vitro Anticoagulant Activity of Human Plasma Lipids

1965 ◽  
Vol 13 (02) ◽  
pp. 531-542
Author(s):  
J Cohen ◽  
C. F Reed ◽  
S. B Troup
Keyword(s):  
Human Plasma ◽  
Inhibitory Activity ◽  
Plasma Lipids ◽  
Present Report ◽  
Anticoagulant Activity ◽  
Lipid Fraction ◽  
Plasma Lipid ◽  
Lipid Mixture ◽  
Platelet Poor Plasma

SummaryThe present report describes the in vitro inhibition of prothrombin consumption by lipid extracted from normal human platelet-poor plasma. Pro-coagulant lipids and the test plasma lipids were dissolved in the same solvent and evaporated to dryness. The dried lipid mixture was emulsified in platelet-poor plasma, and the plasma clotted by recalcification. Inhibition of prothrombin consumption by plasma lipid was observed when the ratio of plasma lipid to procoagulant lipid equaled or exceeded 5:1. The inhibitory effect of plasma lipid on prothrombin consumption was not observed when procoagulant activity was provided by intact platelets or platelet granules.Human plasma lipids have been fractionated on silicic acid columns to permit identification of the plasma lipid component responsible for the inhibition of prothrombin consumption. The inhibitory activity is present in a lipid fraction which is 95% lecithin. Other plasma lipid components exhibit little or no inhibitory activity.

Effect of Lectins and Chemical Modification on the Hemagglutinin Activity of Human Plasma Fibronectin

1981 ◽  
Vol 36 (9-10) ◽  
pp. 863-868 ◽  
Author(s):  
Matti Vuento ◽  
Eija Salonen
Keyword(s):  
Chemical Modification ◽  
Human Plasma ◽  
Present Report ◽  
Red Cells ◽  
Carboxyl Groups ◽  
Plasma Fibronectin ◽  
Cell Surfaces ◽  
Serum Factors ◽  
Low Concentrations ◽  
Erythrocyte Surface

Abstract Purified hum an plasm a fibronectin has been shown to agglutinate protease-treated red cells [Vuento, Hoppe-Seyler's Z. Physiol. Chem. 360, 1327-1333, (1979)]. The present report shows that the activity is inhibited by low concentrations of lectins and by macrom olecular serum factors. Chemical m odification of carboxyl groups of fibronectin strongly inhibited the activity, but modification of am ino groups or guanidinium groups had little effect on the activity. The results suggest that fibronectin receptors on erythrocyte surface are carbohydrate-containing molecules. Humoral m acrom olecular factors may control the interaction of fibronectin with cell surfaces. Chemical m odification studies indicate that the parts of the fibronectin molecule responsible for the hem agglutinin activity are different from those mediating the binding of fibronectin to collagen.

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