Comparison of Caseinolytic and Fibrinolytic Assays for Plasmin (Fibrinolysin) in “Fibrinolytic Agents”

1966 ◽  
Vol 15 (01/02) ◽  
pp. 252-272
Author(s):  
K. M Moser ◽  
Mary Belle Frey
Keyword(s):  
Linear Relationship ◽  
Potential Application ◽  
Fibrinolytic Agents ◽  
Linear Portion

Summary1. Caseinolytic and fibrinolytic systems for assay of plasmin in fibrinolytic agents are described which are based upon the determinations of AE/min during the linear portion of the casein-plasmin and fibrin-plasmin reaction curves respectively. A " caseinolytic-rate " unit and “fibrinolytic-rate " unit of ÄE/min × 103 during the linear portion of the respective curves are proposed.2. Data are presented indicating that a reliably linear relationship exists between plasmin concentration and these caseinolytic - and fibrinolytic-rate units.3. Data comparing results obtained with the proposed assay techniques and previously-used casein and fibrinolytic techniques are presented.4. Formulae by which caseinolytic-rate and fibrinolytic-rate units can be roughly converted into Remmert-Cohen type plasmin units are offered.5. The theoretical and practical problems which have influenced development of assays for fibrinolytic components are discussed.6. The advantages of the plasmin “rate unit” techniques vis a vis existing assays are delineated.7. The potential application of the techniques to measurements other than the plasmin content of fibrinolytic agents is discussed.

Post-mortem Peyer’s patches: Their potential application in forensic medicine

2009 ◽  
Vol 00 (00) ◽  
pp. 090513010017019-7
Author(s):  
Biagio Solarino ◽  
Giancarlo Di Vella ◽  
Thea Magrone ◽  
Felicita Jirillo ◽  
Angela Tafaro ◽  
...  
Keyword(s):  
Forensic Medicine ◽  
Potential Application ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Post Mortem

The Human Prothrombin-Activating Enzyme

1969 ◽  
Vol 22 (01) ◽  
pp. 045-067 ◽  
Author(s):  
K Deggeller ◽  
J Vreeken
Keyword(s):  
Linear Relationship ◽  
Factor Xa ◽  
Enzyme Concentration ◽  
Factor V ◽  
Factor X ◽  
Active Centers ◽  
Factor Va

SummaryThe formation and action of human prothrombin-activating enzyme is described. The study of the formation of the enzyme leads to the following conclusions :1. The enzyme is formed from factor V, factor X and phospholipid in the presence of calcium. If one of the reagents is omitted no activity develops.2. Factor V and factor X need activation by thrombin and for instance Russell Viper Venom, respectively.3. A linear relationship exists between the inverse of factor Va concentration and the inverse of enzyme concentration.4. A linear relationship exists between the inverse of factor Xa concentration and the inverse of enzyme concentration.5. A linear relationship exists between the inverse of phospholipid concentration and the inverse of enzyme concentration at small phospholipid concentration.6. A linear relationship exists between the phospholipid concentration and the inverse of enzyme concentration at high phospholipid concentration.The study of the action of the enzyme leads to the conclusion that human prothrombin is substrate and an inhibitor if present in excess.The observed phenomena are best explained by the hypothesis that factor Va and factor Xa adsorb onto the phospholipid surface. When both factors are adsorbed close together they are active as an enzyme. This activity depends on two active centers, probably one derived from factor Va and one from factor Xa.

The Effects of Sodium Citrate and an Excess of Plasminogen on Fibrinolytic Agents

1960 ◽  
Vol 04 (03) ◽  
pp. 462-472 ◽  
Author(s):  
Tage Astrup ◽  
Ida Sterndorff
Keyword(s):  
Fumaric Acid ◽  
Maleic Acid ◽  
Fibrinolytic Activity ◽  
Sodium Citrate ◽  
Plasminogen Activators ◽  
Fibrinolytic Agents ◽  
Enhancing Effect ◽  
Polycarboxylic Acids

Summary1. The presence of citrate in the normal fibrin enhanced the fibrinolytic activity of plasminogen activators, including trypsin. The effect of proteases (on normal or on heated fibrin, containing citrate) was not significantly influenced.2. The effect of plasminogen activators was also increased when excess of plasminogen was present in the normal fibrin plates.3. Fumaric acid and maleic acid belong to the polycarboxylic acids producing an enhancing effect.

Effect of Bentonite on Fibrinolytic System in Serum

1963 ◽  
Vol 10 (01) ◽  
pp. 120-132 ◽  
Author(s):  
E. S Olesen
Keyword(s):  
Guinea Pig ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
High Potential ◽  
Fibrinolytic System ◽  
Fibrinolytic Agents ◽  
Isoelectric Precipitation ◽  
Active Protease ◽  
Pig Serum

SummaryTreatment of serum with bentonite led to a reduced content of inhibitors of trypsin and urokinase in the isoelectrically precipitated euglobulin, and removed fibrinolytic agents and precursors from serum. Bentonite-treated serum added to untreated serum reduced precipitation of the above inhibitors, and presumably also precipitation of inhibitors against a plasminogen activator of serum.Bentonite-treated serum (whether from pig, ox, guinea-pig, or man), added to untreated guinea-pig serum, produced fibrinolytic activity on isoelectric precipitation of the mixture; the activity of the euglobulin was due to an activator of plasminogen as well as an active protease, probably plasmin. The described effects of bentonite-treated serum are similar to those previously reported for anionic polyelectrolytes. Possible mechanisms are discussed.The “non-specific” activation of fibrinolytic activity by means of bentonite emphasizes that guinea-pig serum [which is characterized by a high potential for “nonspecific” activation of its fibrinolytic system Olesen (1962)] contains all the elements required for the formation of an activator of plasminogen, and thus the activation of its plasminogen to plasmin.

Interaction of Heparin with Fibrinolysis

1963 ◽  
Vol 09 (02) ◽  
pp. 446-458 ◽  
Author(s):  
Rudolf Holemans ◽  
Dionysios Adamis ◽  
James F Horace
Keyword(s):  
Human Plasma ◽  
Fibrinolytic Activity ◽  
Plasminogen Activation ◽  
Fibrinolytic Agents ◽  
High Concentration ◽  
Enhancing Effect

SummaryHeparin in high concentration inhibits the fibrinolysis of human plasma clots or bovine fibrin by fibrinolytic agents which produce plasminogen activation. Heparin has no effect on the fibrinolytic activity of plasmin or Aspergillus protease.In order to produce inhibition of plasminogen activation heparin requires the presence of a co-factor which is present in citrated human plasma but absent from its euglobulin fraction.In none of the concentrations tested has heparin an enhancing effect on fibrinolysis.

Pretreatment of Human Platelets with Plasmin Inhibits Responses toThrombin, but Potentiates Responses to Low Concentrations of Aggregating Agents, Including the Thrombin Receptor Activating Peptide, SFLLRN

1997 ◽  
Vol 77 (04) ◽  
pp. 741-747 ◽  
Author(s):  
R L Kinlough-Rathbone ◽  
D W Perry ◽  
M L Rand ◽  
M A Packham
Keyword(s):  
Arachidonic Acid ◽  
Platelet Activating Factor ◽  
Human Platelets ◽  
Thrombin Receptor ◽  
Fibrinolytic Agents ◽  
Albumin Solution ◽  
Fibrinogen Receptor ◽  
Low Concentrations ◽  
Induced Aggregation

SummaryEffects of plasmin on platelets, that influence subsequent responses to aggregating agents, are relevant to attempts to prevent rethrombosis following administration of fibrinolytic agents. We describe plasmin-induced inhibition of platelet responses to thrombin, but potentiation of responses to other aggregating agents. Washed human platelets were labeled with 14C-serotonin, treated for 30 min at 37° C with 0, 0.1 or 0.2 CU/ml of plasmin, followed by aprotinin, washed and resuspended in a Tyrode-albumin solution with apyrase. Incubation with 0.2 CU/ml of plasmin almost completely inhibited thrombin-induced (0.1 U/ml) aggregation, release of 14C-serotonin, and increase in cytosolic [Ca2+]. In contrast, with plasmin-pretreated platelets, aggregation and release of 14C-serotonin were strongly potentiated in response to low concentrations of the thrombin receptor-activating peptide SFLLRN, ADP, platelet-activating factor, collagen, arachidonic acid, the thromboxane mimetic U46619, and the calcium ionophores A23187 and ionomycin. Aspirin or RGDS partially inhibited potentiation. Plasmin-pretreated platelets resuspended in plasma anticoagulated with FPRCH2C1 (PPACK) also showed enhanced responses to aggregating agents other than thrombin. The contrasting effects on responses to thrombin and SFLLRN are noteworthy. Plasmin cleaves GPIIb/IIIa so that it becomes a competent fibrinogen receptor, and binding of 125I-fibrinogen during ADP-induced aggregation was greatly potentiated within 10 s. Potentiation of aggregation by other agonists may be due to increased binding of released fibrinogen. Thus, platelets freed from a thrombus may have increased responsiveness to low concentrations of aggregating agents other than thrombin. These results provide further support for the use of inhibitors of platelet reactions in conjunction with administration of fibrinolytic agents.

Determination of the International Sensitivity Index of a New Near-Patient Testing Device to Monitor Oral Anticoagulant Therapy

1997 ◽  
Vol 78 (02) ◽  
pp. 855-858 ◽  
Author(s):  
Armando Tripodi ◽  
Veena Chantarangkul ◽  
Marigrazia Clerici ◽  
Barbara Negri ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Linear Relationship ◽  
Whole Blood ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Calibration Model ◽  
Testing Device ◽  
Data Points ◽  
Near Patient Testing

SummaryA key issue for the reliable use of new devices for the laboratory control of oral anticoagulant therapy with the INR is their conformity to the calibration model. In the past, their adequacy has mostly been assessed empirically without reference to the calibration model and the use of International Reference Preparations (IRP) for thromboplastin. In this study we reviewed the requirements to be fulfilled and applied them to the calibration of a new near-patient testing device (TAS, Cardiovascular Diagnostics) which uses thromboplastin-containing test cards for determination of the INR. On each of 10 working days citrat- ed whole blood and plasma samples were obtained from 2 healthy subjects and 6 patients on oral anticoagulants. PT testing on whole blood and plasma was done with the TAS and parallel testing for plasma by the manual technique with the IRP CRM 149S. Conformity to the calibration model was judged satisfactory if the following requirements were met: (i) there was a linear relationship between paired log-PTs (TAS vs CRM 149S); (ii) the regression line drawn through patients data points, passed through those of normals; (iii) the precision of the calibration expressed as the CV of the slope was <3%. A good linear relationship was observed for calibration plots for plasma and whole blood (r = 0.98). Regression lines drawn through patients data points, passed through those of normals. The CVs of the slope were in both cases 2.2% and the ISIs were 0.965 and 1.000 for whole blood and plasma. In conclusion, our study shows that near-patient testing devices can be considered reliable tools to measure INR in patients on oral anticoagulants and provides guidelines for their evaluation.

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