Plasminogen Assay by Means of the Lysis Time Method

1965 ◽  
Vol 14 (01/02) ◽  
pp. 127-144 ◽  
Author(s):  
W Berg ◽  
K Korsan-Bengtsen ◽  
J Ygge
Keyword(s):  
Maximal Activity ◽  
Fibrin Clot ◽  
Order Reaction ◽  
Zero Order ◽  
Fibrinogen Concentration ◽  
Plasmin Activity ◽  
Consecutive Reactions ◽  
Lysis Time ◽  
Straight Line

SummaryThe lysis time method for the determination of plasminogen has been investigated using plasminogen-free thrombin and fibrinogen preparations.The experiments have shown that the lysis of a fibrin clot is the result of two consecutive reactions: the formation of fibrin which proceeds as a first order reaction and the degradation of fibrin which proceeds as a zero order reaction. Plasminogen is activated in a separate reaction. If the rate of the fibrin formation is much greater than the rate of degradation, the lysis of the fibrin clot is approximately of zero order in fibrin. The lysis time will then be inversely proportional to the plasmin concentration and proportional to the fibrinogen concentration. In a double logaritmic system the correlation between lysis time and plasmin activity is a straight line with a slope of 135°.Plasminogen is rapidly activated with streptokinase. Maximal activation is obtained only with a certain streptokinase concentration. Higher concentrations inactivate plasmin and with lower concentrations, the maximal activity is never reached. A spontaneous inactivation is seen after about 30 minutes. With urokinase, a higher maximal plasminogen activity is obtained than with streptokinase. Urokinase in higher concentrations does not inactivate plasmin.A standard assay for determination of plasminogen by the lysis time method has been worked out and is based on these results.

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.

A Method to Correct for the Continuing Activation during the Second Stage in a Two-Stage Assay

1968 ◽  
Vol 19 (01/02) ◽  
pp. 161-168
Author(s):  
W Berg
Keyword(s):  
Kinetic Data ◽  
Quantitative Methods ◽  
Order Reaction ◽  
Second Order Reaction ◽  
Plasmin Activity ◽  
Second Stage ◽  
Lysis Time ◽  
The Moment ◽  
Coagulation And Fibrinolysis

SummaryIn coagulation and fibrinolysis, kinetic data are difficult to obtain with ordinary quantitative methods because no simple means are available to stop the reaction before the determination of the activity formed.This work describes how to calculate, from the data recorded, the amount of activity at the moment the determination is started.A formula is given for a zero, a first and a second-order reaction.The method is exemplified by urokinase activation of plasminogen into plasmin. The determination of the plasmin activity is done by means of the lysis time method.

Determination of Plasma Urokinase Levels by Chromogenic Assay Levels: Comparison of Levels Attained During Infusion of Tissue Culture and Urinary Source Urokinase Preparations

1979 ◽  
Author(s):  
Grant H. Barlow ◽  
Victor J. Marder
Keyword(s):  
Tissue Culture ◽  
Critical Concentration ◽  
Source Material ◽  
Fibrinogen Concentration ◽  
Loading Dose ◽  
Chromogenic Assay ◽  
Culture Material ◽  
Lysis Time ◽  
Hourly Rate

Plasma urokinase levels were determined using the chromogenic substrate L-Pyroglutamyl-glycyl-L-arginine-p-nitroanalide (KABI S2444) on plasma samples collected before, during and after Infusions of tissue culture or urinary source urokinase (J, Lab. Clin. Med. 92:721, 1978). Each patient received a 2,000 IU/lb loading dose followed by an hourly rate of 2,000 IU/lb for 12 hours. There was no correlation between plasma urokinase level and critical concentration of drug or body weight and no difference in the effects of each preparation on laboratory reflections of a lytic state, such as the whole blood euglobulln lysis time, plasminogen or fibrinogen concentration. However, the chromogenic assay of urokinase activity showed that the urinary source material achieved a significantly higher plasma blood level at two hours and disappeared more rapidly after termination of the infusion than was observed with the tissue culture material. Although both urokinase infusions achieved plasma levels in excess of that required to produce a fibrinogenolytic state, it is likely that a significantly lower concentration is sufficient to produce a lytic state and that a larger dose of tissue culture material would be required to achieve this critical plasma urokinase level.

A SPECTROPHOTOMETRIC METHOD FOR FIBRIN CLOT LYSIS ASSAY

1987 ◽  
Author(s):  
A Electricwala
Keyword(s):  
Biological Fluids ◽  
Fibrin Clot ◽  
Calibration Graph ◽  
Assay Method ◽  
Clot Lysis ◽  
End Point ◽  
Straight Line ◽  
Absorbance Peak ◽  
The Many

Clot lysis assay is one of the many methods being used to quantitate tissue plasminogen activator in biological fluids and other media. It has been suggested that this assay may be less reproducible and subject to error due to variation between laboratories in determining the end point of clot lysis, especially at lower concentrations of the activator. It has been found that this assay method can be semi-automated by monitoring the absorbance of the fibrin clot, and determining the end point, in a spectrophotometer. Standard clots containing varying concentrations of tPA are prepared in semi-micro cuvettes, held at 37° C and the absorbance monitored continuosly at 600nm. The turbidity of the sample is increased near its lytic time, which results in a sharp absorbance peak. The time elapsed from the start to the appearence of this peak is taken as the lytic time of the clot. Using standard prepration of tPA, a straight line calibration graph of log lytic time versus log concentration is obtained, with a standard deviation for each determination of ± 5%. This method has the advantage of being simple, reproducible and less prone to operator error.

The Contribution of Individual Protease Inhibitors to Plasma Antiplasmin Activity

1975 ◽  
Author(s):  
G. P. M. Crawford ◽  
D. Ogston ◽  
A. S. Douglas
Keyword(s):  
Protease Inhibitors ◽  
Trypsin Inhibitor ◽  
Antithrombin Iii ◽  
Correlation Coefficients ◽  
Zero Order ◽  
Plasmin Activity ◽  
Valid Assessment ◽  
Alpha 1 Antitrypsin ◽  
The Individual

The plasma proteins alpha-1-antitrypsin, alpha-2-macroglobulin, antithrombin III, Cl inhibitor and inter-alpha trypsin inhibitor have been shown to be capable of inhibiting plasmin activity. Whole plasma possesses both ‘rapid’ and ‘progressive’ plasminneutralising activity: the study was intended to assess the contribution of individual protease inhibitors to this plasminneutralising activity.The antiplasmin properties, assessed as ‘rapid’ and ‘progressive’ by the neutralisation of plasmin in a caseinolytic assay, and the levels of the individual protease inhibitors, assayed by single radial immunodiffusion, were measured in the plasma of 35 subjects. Statistical analysis using zero order correlation coefficients and zero order partial correlation coefficients indicated that ‘rapid’ and ‘progressive’ antiplasmin activity correlated with the plasma concentration of alpha-2-macroglobulin and alpha-1-antitrypsin respectively, but not with antithrombin III, Cl inhibitor and interalpha trypsin inhibitor.It is concluded that alpha-2-macroglobulin and alpha-1-antitrypsin are the major plasma inhibitors of plasmin and that immunological determination of these proteins provides a valid assessment of plasma antiplasmin activity.

Intensification of cooling in a batch reactor with an exothermic reaction by nonisothermal control in stable pseudostationary states

1984 ◽  
Vol 49 (11) ◽  
pp. 2566-2578 ◽  
Author(s):  
Josef Horák ◽  
Petr Beránek ◽  
Dagmar Maršálková
Keyword(s):  
Batch Reactor ◽  
Exothermic Reaction ◽  
Reaction Model ◽  
Order Reaction ◽  
Zero Order ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Adaptive Parameter ◽  
Zero Order Reaction ◽  
Set Up

An algorithm is set up and tested for the temperature control of a batch reactor consisting in jump changes in the inlet temperature of entering coolant. This temperature is so chosen that its difference from the temperature of the reaction mixture is near the highest difference at which the stable pseudostationary state of the system still exists. For the prediction of the new coolant inlet temperature, a zero-order reaction model is used with an adaptive parameter estimated from the experimentally established value of the maximum of the reaction mixture overheating at the previous coolant temperature.

Kinetics of the reaction between hexamethylenediisocyanate and 1-pentanol

1983 ◽  
Vol 48 (11) ◽  
pp. 3279-3286
Author(s):  
Slavko Hudeček ◽  
Miloslav Bohdanecký ◽  
Ivana Hudečková ◽  
Pavel Špaček ◽  
Pavel Čefelín
Keyword(s):  
Liquid Chromatography ◽  
Rate Constants ◽  
Reversed Phase ◽  
Order Reaction ◽  
Second Order ◽  
Second Order Reaction ◽  
Reversed Phase Liquid Chromatography ◽  
Consecutive Reactions ◽  
Phase Liquid ◽  
Kinetics Of

The reaction between hexamethylenediisocyanate and 1-pentanol in toluene was studied by means of reversed-phase liquid chromatography. By employing this method, it was possible to determine all components of the reaction mixture including both products, i.e. N-(6-isocyanate hexyl)pentylcarbamate and N,N'-bis(pentyloxycarbonyl)hexamethylenediamine. Relations for the calculation of kinetic constants were derived assuming a competitive consecutive second-order reaction. It was demonstrated that the reaction involved in this case is indeed a second-order reaction, and the rate constants of the first and second consecutive reactions were determined.

scholarly journals Validated spectral manipulations for determination of an anti-neoplastic drug and its related impurities including its hazardous degradation product

RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21332-21342
Author(s):  
Ibrahim A. Naguib ◽  
Eglal A. Abdelaleem ◽  
Eman S. Hassan ◽  
Aml A. Emam
Keyword(s):  
Absorption Spectra ◽  
Degradation Product ◽  
Zero Order ◽  
Sterile Water ◽  
Related Impurities ◽  
Amino Imidazole

Zero order absorption spectra of 12 μg mL−1 of Dacarbazine (), 5-amino-imidazole-4 carboxamide (), and 2-azahypoxanthine (…) using sterile water as a blank.

Duplex Spread Blade Method for Cutting Hypoid Gears with Modified Tooth Surface

1998 ◽  
Vol 120 (3) ◽  
pp. 441-447 ◽  
Author(s):  
K. Kawasaki ◽  
H. Tamura
Keyword(s):  
Cutting Edge ◽  
Tooth Surface ◽  
Radius Of Curvature ◽  
Large Radius ◽  
Ring Gear ◽  
Circular Arc ◽  
Hypoid Gears ◽  
Manufacturing Method ◽  
Straight Line

In this paper, a duplex spread blade method for cutting hypoid gears with modified tooth surface is proposed. The duplex spread blade method provides a rapid and economical manufacturing method because both the ring gear and pinion are cut by a spread blade method. In the proposed method, the nongenerated ring gear is manufactured with cutting edge that is altered from the usual straight line to a circular arc with a large radius of curvature and the circular arc cutting edge produces a modified tooth surface. The pinion is generated by a cutter with straight cutting edges as usual. The main procedure of this method is the determination of the cutter specifications and machine settings. The proposed method was validated by gear manufacture.

Altered fibrin clot structure/function in patients with antiphospholipid syndrome: association with thrombotic manifestation

2014 ◽  
Vol 112 (08) ◽  
pp. 287-296 ◽  
Author(s):  
Magdalena Celińska-Löwenhoff ◽  
Teresa Iwaniec ◽  
Agnieszka Padjas ◽  
Jacek Musiał ◽  
Anetta Undas
Keyword(s):  
Structure Function ◽  
Antiphospholipid Syndrome ◽  
Thrombotic Event ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Lag Phase ◽  
Lysis Time ◽  
Clot Structure ◽  
Clot Lysis Time ◽  
D Dimer

SummaryWe tested the hypothesis that plasma fibrin clot structure/function is unfavourably altered in patients with antiphospholipid syndrome (APS). Ex vivo plasma clot permeability, turbidity and susceptibility to lysis were determined in 126 consecutive patients with APS enrolled five months or more since thrombotic event vs 105 controls. Patients with both primary and secondary APS were characterised by 11% lower clot permeability (p<0.001), 4.8% shorter lag phase (p<0.001), 10% longer clot lysis time (p<0.001), and 4.7% higher maximum level of D-dimer released from clots (p=0.02) as compared to the controls. Scanning electron microscopy images confirmed denser fibrin networks composed of thinner fibres in APS. Clots from patients with “triple-antibody positivity” were formed after shorter lag phase (p=0.019) and were lysed at a slower rate (p=0.004) than in the remainder. Clots from APS patients who experienced stroke and/or myocardial infarction were 8% less permeable (p=0.01) and susceptible to lysis (10.4% longer clot lysis time [p=0.006] and 4.5% slower release of D-dimer from clots [p=0.01]) compared with those following venous thromboembolism alone. Multivariate analysis adjusted for potential confounders showed that in APS patients, lupus anticoagulant and “triple-positivity” were the independent predictors of clot permeability, while “triple-positivity” predicted lysis time. We conclude that APS is associated with prothrombotic plasma fibrin clot phenotype, with more pronounced abnormalities in arterial thrombosis. Molecular background for this novel prothrombotic mechanism in APS remains to be established.

Sign in / Sign up

Export Citation Format

Share Document