Automated nephelometry of fibrinogen: analytical performance and observations during thrombolytic therapy.

1988 ◽  
Vol 34 (10) ◽  
pp. 2135-2140 ◽  
Author(s):  
J J Hoffmann ◽  
M A Verhappen
Keyword(s):  
Thrombolytic Therapy ◽  
Degradation Products ◽  
Oral Anticoagulants ◽  
Fibrinogen Concentration ◽  
Clotting Time ◽  
Protein Assay ◽  
Laboratory Results ◽  
High Concentrations ◽  
Coagulation Analyzer

Abstract We evaluated the performance of an automated nephelometric determination of fibrinogen, which is an integral part of the prothrombin time assay, in a new coagulation analyzer, the ACL-810 (Instrumentation Laboratory). Results were compared with those by a total clottable protein assay and with the thrombin clotting time assay for fibrinogen. In normal and slightly abnormal plasma, the performance of the ACL method was quite satisfactory (CV 3-10%). However, in abnormal plasma (prolonged prothrombin times because of heparin or oral anticoagulants) the accuracy of the ACL method was poor. Nor could the instrument determine fibrinogen in clearly lipemic plasma. In plasma containing high concentrations of fibrin(ogen) degradation products (FDP), collected during thrombolytic therapy with streptokinase-containing drugs, the ACL method gave spuriously high values for fibrinogen concentration. We determined that this was mainly because of interference by intermediate FDP (fragment Y). Finally, we demonstrated that early FDP (fragment X) increased the ACL results for fibrinogen to the same extent as in the total clottable protein method and that late FDP (fragments D and E) affected the thrombin clotting time method, but not the ACL fibrinogen determination.

A Rapid Method for the Semiquantitative Determination of Fibrinogen and Fibrinogen Degradation Products (FDP) in Defibrination Syndrome

1971 ◽  
Vol 25 (03) ◽  
pp. 555-565 ◽  
Author(s):  
G Sas ◽  
J Jákó ◽  
J Domán ◽  
C László ◽  
J Pádár
Keyword(s):  
Degradation Products ◽  
Substantial Reduction ◽  
Experimental System ◽  
Fibrinogen Concentration ◽  
Thrombin Time ◽  
Clotting Time ◽  
Fibrinogen Degradation Products ◽  
Linear Plot ◽  
Fibrinogen Content

Summary1. It was found that effects of deliberate changes in fibrinogen concentration and in the amount of FDP added to the experimental system (containing pure fibrinogen solution and saline- or serumdiluted plasma) could be approximated with satisfactory accuracy by a linear plot of the logarithm of clotting times versus the inverse of fibrinogen concentration.By increasing FDP activity the slope of the obtained lines becomes proportionately steeper. The constants, which interrelate clotting time, fibrinogen concentration and FDP activity, are to be derived experimentally. The obtained formula is expressed also nomographically.2. Apart from the presence of some very rare anticoagulants, an elongation of thrombin time observed under strictly specified conditions points to a substantial reduction of fibrinogen concentration and/or an interplay of fibrinogen degradation products.If a definite amount of fibrinogen (Fibrinogen sec. Warner Chilcott) is admixed to a pathological plasma, thrombin time in the latter will decrease in a specifiable manner. By entering the original and corrected thrombin time values in the reported nomogram the fibrinogen content and FDP activity of the pathological plasma can be calculated.3. The described procedure for fibrinogen and FDP assay is suitable first of all in acute defibrination syndrome and at the thrombolytic therapy. Its agreement with the results obtained by immunodiffusion was satisfactory as regards the fibrinogen in plasmas of different fibrinogen concentration.

Fibrinogen Bastia (γ 318 Asp → Tyr) a Novel Abnormal Fibrinogen Characterized by Defective Fibrin Polymerization

1999 ◽  
Vol 82 (12) ◽  
pp. 1639-1643 ◽  
Author(s):  
Karim Chabane Lounes ◽  
Claudine Soria ◽  
Antoine Valognes ◽  
Marie France Turchini ◽  
Jaap Koopman ◽  
...  
Keyword(s):  
Calcium Ions ◽  
Clinical Symptoms ◽  
Degradation Products ◽  
Base Substitution ◽  
Chain Gene ◽  
Fibrinogen Concentration ◽  
Clotting Time ◽  
Terminal Part ◽  
Fibrin Polymerization ◽  
Chain Sequence

SummaryA new congenital dysfibrinogen, Fibrinogen Bastia, was discovered in a 20-year-old woman with no clinical symptoms. The plasma thrombin-clotting time was severely prolonged. The functional plasma fibrinogen concentration was low (0.2 mg/ml), whereas the immunological concentration was normal (2.9 mg/ml). Purified fibrinogen Bastia displayed a markedly prolonged thrombin-clotting time related to a delayed thrombin-induced fibrin polymerization. Both the thrombin-clotting time and the fibrin polymerization were partially corrected by the addition of calcium ions. The anomaly of fibrinogen Bastia was found to be located in the γ-chain since by SDS-PAGE performed according to the method of Laemmli two γ-chains were detected, one normal and one with an apparently lower molecular weight. Furthermore, analysis of plasmin degradation products demonstrated that calcium ions only partially protect fibrinogen Bastia γ-chain against plasmin digestion, suggesting that the anomaly is located in the C-terminal part of the γ-chain. Sequence analysis of PCR-amplified genomic DNA fragments of the propositus demonstrated a single base substitution (G → T) in the exon VIII of the γ chain gene, resulting in the amino acid substitution 318 Asp (GAC) → Tyr (TAC). The PCR clones were recloned and 50% of them contained the mutation, indicating that the patient was heterozygous. These data indicate that residue Asp 318 is important for normal fibrin polymerization and the protective effect of calcium ions against plasmin degradation of the C-terminal part of the γ-chain.

scholarly journals Viscoelastometry for detecting oral anticoagulants

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Philipp Groene ◽  
Daniela Wagner ◽  
Tobias Kammerer ◽  
Lars Kellert ◽  
Andreas Giebl ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Prospective Observational Study ◽  
Oral Anticoagulants ◽  
Plasma Concentrations ◽  
Factor Xa ◽  
Clotting Time ◽  
Emergency Situations ◽  
Tissue Plasminogen ◽  
The Impact

Abstract Background Determination of anticoagulant therapy is of pronounced interest in emergency situations. However, routine tests do not provide sufficient insight. This study was performed to investigate the impact of anticoagulants on the results of viscoelastometric assays using the ClotPro device. Methods This prospective, observational study was conducted in patients receiving dabigatran, factor Xa (FXa)-inhibitors, phenprocoumon, low molecular weight heparin (LMWH) or unfractionated heparin (UFH) (local ethics committee approval number: 17–525-4). Healthy volunteers served as controls. Viscoelastometric assays were performed, including the extrinsic test (EX-test), intrinsic test (IN-test) Russel’s viper venom test (RVV-test), ecarin test (ECA-test), and the tissue plasminogen activator test (TPA-test). Results 70 patients and 10 healthy volunteers were recruited. Clotting time in the EX-test (CTEX-test) was significantly prolonged versus controls by dabigatran, FXa inhibitors and phenprocoumon. CTIN-test was prolonged by dabigatran, FXa inhibitors and UFH. Dabigatran, FXa inhibitors and UFH significantly prolonged CTRVV-test in comparison with controls (median 200, 207 and 289 vs 63 s, respectively; all p < 0.0005). Only dabigatran elicited a significant increase in CTECA-test compared to controls (median 307 vs 73 s; p < 0.0001). CTECA-test correlated strongly with dabigatran plasma concentration (measured by anti-IIa activity; r = 0.9970; p < 0.0001) and provided 100% sensitivity and 100% specificity for detecting dabigatran. Plasma concentrations (anti-XA activity) of FXa inhibitors correlated with CTRVV-test (r = 0.7998; p < 0.0001), and CTRVV-test provided 83% sensitivity and 64% specificity for detecting FXa inhibitors. Conclusions In emergency situations, ClotPro viscoelastometric assessment of whole-blood samples may help towards determining the presence and type of anticoagulant class that a patient is taking. Trial registration German clinical trials database ID: DRKS00015302.

Analysis of fibrin formation and proteolysis during intravenous administration of ancrod

Blood ◽  
2000 ◽  
Vol 96 (8) ◽  
pp. 2793-2802
Author(s):  
Carl-Erik Dempfle ◽  
Sotiria Argiriou ◽  
Klaus Kucher ◽  
H. Müller-Peltzer ◽  
Klaus Rübsamen ◽  
...  
Keyword(s):  
Degradation Products ◽  
Monomer Unit ◽  
Threshold Concentration ◽  
Tissue Type ◽  
Considerable Proportion ◽  
Fibrinogen Concentration ◽  
Stroke Treatment ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
High Concentrations

Ancrod is a purified fraction of venom from the Malayan pit viper, Calloselasma rhodostoma, currently under investigation for treatment of acute ischemic stroke. Treatment with ancrod leads to fibrinogen depletion. The present study investigated the mechanisms leading to the reduction of plasma fibrinogen concentration. Twelve healthy volunteers received an intravenous infusion of 0.17 U/kg body weight of ancrod for 6 hours. Blood samples were drawn and analyzed before and at various time points until 72 hours after start of infusion. Ancrod releases fibrinopeptide A from fibrinogen, leading to the formation of desAA-fibrin monomer. In addition, a considerable proportion of desA-profibrin is formed. Production of desA-profibrin is highest at low concentrations of ancrod, whereas desA-profibrin is rapidly converted to desAA-fibrin at higher concentrations of ancrod. Both desA-profibrin and desAA-fibrin monomers form fibrin complexes. A certain proportion of complexes carries exposed fibrin polymerization sites EA, indicating that the terminal component of the protofibril is a desAA-fibrin monomer unit. Soluble fibrin complexes potentiate tissue-type plasminogen activator-induced plasminogen activation. Significant amounts of plasmin are formed when soluble fibrin in plasma reaches a threshold concentration, leading to the proteolytic degradation of fibrinogen and fibrin. In the present setting, high concentrations of soluble fibrin are detected after 1 hour of ancrod infusion, whereas a rise in fibrinogen and fibrin degradation products, and plasmin-α2–plasmin inhibitor complex levels is first detected after 2 hours of ancrod infusion. Ancrod treatment also results in the appearance of cross-inked fibrin degradation productd-dimer in plasma.

Determination of Fibrinogen and Fibrinogenolytic Activity

1962 ◽  
Vol 08 (02) ◽  
pp. 297-310 ◽  
Author(s):  
Inga Marie Nilsson ◽  
Bertil Olow
Keyword(s):  
Thrombolytic Therapy ◽  
Fibrinolytic Activity ◽  
Fibrinogen Level ◽  
Plasma Fibrinogen ◽  
Fibrinogen Concentration ◽  
Plasma Fibrinogen Level ◽  
Fibrinogenolytic Activity ◽  
The Difference ◽  
The Moment

SummaryA method for determining plasma fibrinogen and fibrinogenolytic activity, with epsilonaminocaproic acid (ε-ACA) as an inhibitor of fibrinolysis, in patients with high fibrinolytic activity, is described in detail.The fibrinogen was determined by a modification of Morrison’s syneresis method in parallel in 1. citrated plasma that was incubated for 2 hours at 37° C, after which further digestion was prevented by addition of ε-ACA and is referred to as fibrinogen A, and 2. in citrated plasma prepared from blood collected in tubes containing ε-ACA to prevent activation of plasminogen and is referred to as fibrinogen B. The difference between fibrinogen B and fibrinogen A gives the amount of lysed fibrinogen in 2 hours at 37° C. Fibrinogen B gives the fibrinogen concentration at the moment of sampling.The method is recommended to be used for evaluation of the true plasma fibrinogen level and the degree of fibrinogenolytic activity. This is particularly important during thrombolytic therapy.

New method for determining thrombin-clottable fibrinogen.

1977 ◽  
Vol 23 (11) ◽  
pp. 2103-2106 ◽  
Author(s):  
A Frigola ◽  
S Angeloni ◽  
A R Cerqueti
Keyword(s):  
Serum Proteins ◽  
Degradation Products ◽  
Fibrin Clot ◽  
New Method ◽  
Good Precision ◽  
Fibrin Degradation Product ◽  
Fibrin Degradation Products ◽  
High Concentrations ◽  
Method R

Abstract We describe a new method for determination of thrombin-clottable fibrinogen, which eliminates the systematic error caused by occlusion of other serum proteins in the fibrin clot and reduces the sensitivity to high concentrations of fibrin degradation products. Essentially, the method consists of densitometric quantitation of the fibrin band after a standard electrophoresis run of plasma, thrombin fixation of the fibrinogen, and removal of the non-clotted proteins by washing in saline. The procedure shows good precision and gives results that are accurate, significantly correlate with results for the classical thrombin clotting method (r = 0.92, P less than .001), and are not affected by fibrin degradation product concentrations up to 900 mg/liter. These characteristics make the method especially valuable in establishing fibrogen concentration in patients who are undergoing thrombolytic therapy.

Bestimmung partieller photochemisdier Quantenausbeuten iiber kombinierte Absorptions- und Fluoreszenzmessung / On the Determination of Partial Photochemical Quantum Yields by Combined Absorbance and Fluorescence Measurement

1981 ◽  
Vol 36 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Frank ◽  
G. Gauglitz
Keyword(s):  
Fluorescent Dyes ◽  
Degradation Products ◽  
Quantum Yields ◽  
Fluorescence Measurement ◽  
Laser Dyes ◽  
Fluorescence Reaction ◽  
High Concentrations ◽  
Set Up ◽  
Reaction Spectrum

A combined automatic set up for the measurement of fluorescence and absorbance is described. The absorbance at irradiation wavelength E' and a fluorescence reaction spectrum are measured continously and simultaneously. Even for solutions with high concentrations up to E'>1, the fluorescence intensity can be corrected for. By this method the photodegradation of fluorescent dyes was examined. Because only a few of the degradation products fluoresce, the determination of kinetic parameters is easier than from absorbance measurements. The method gave good results for laser dyes using even high concentrations (E'> 1), with less calculatory expenditure and smaller standard deviation in comparison to the evaluation of absorbance measurements only

Modification of Lowry's protein assay for the determination of protein in high concentrations of sodium hydroxide

The Analyst ◽  
1982 ◽  
Vol 107 (1277) ◽  
pp. 960
Author(s):  
H. P. S. Makkar ◽  
O. P. Sharma ◽  
R. K. Dawra ◽  
S. S. Negi
Keyword(s):  
Sodium Hydroxide ◽  
Protein Assay ◽  
High Concentrations

Effect of low fibrinogen concentrations on the rheology of human blood in vitro

1979 ◽  
Vol 236 (3) ◽  
pp. H447-H450
Author(s):  
W. Blattler ◽  
P. W. Straub ◽  
C. Jeanneret ◽  
G. S. Horak
Keyword(s):  
Human Blood ◽  
Cell Aggregation ◽  
Fibrinogen Concentration ◽  
Shear Rates ◽  
Red Blood Cell Aggregation ◽  
Low Concentrations ◽  
Normal Human ◽  
High Concentrations

The influence of low concentrations of fibrinogen on the rheology of normal human blood was investigated with an instrument that permitted simultaneous determination of viscosity and the state of red blood cell aggregation and deformation. Fibrinogen, in concentrations of 9-82 mg/100 ml, decreased blood viscosity at all shear rates below the value obtained with red blood cells suspended in serum. At concentrations above 116 mg/100 ml viscosity was increased. Aggregate formation increased progressively as the fibrinogen concentration increased, necessitating higher dispersing shear rates. The deformation and alignment of the red cells, occurring at a shear rate of 230 s-1, was facilitated by low concentrations. The effect of fibrinogen on low-shear viscosity is explained by the formation of different kinds of aggregates. At low concentrations, the aggregates consist of only few cells forming spherelike particles displaying hemodynamic properties better than those of the single discoid cells. At normal or high concentrations big rodlike aggregates occur and increase resistance to flow.

Analysis of fibrin formation and proteolysis during intravenous administration of ancrod

Blood ◽  
2000 ◽  
Vol 96 (8) ◽  
pp. 2793-2802 ◽  
Author(s):  
Carl-Erik Dempfle ◽  
Sotiria Argiriou ◽  
Klaus Kucher ◽  
H. Müller-Peltzer ◽  
Klaus Rübsamen ◽  
...  
Keyword(s):  
Degradation Products ◽  
Monomer Unit ◽  
Threshold Concentration ◽  
Tissue Type ◽  
Considerable Proportion ◽  
Fibrinogen Concentration ◽  
Stroke Treatment ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
High Concentrations

Abstract Ancrod is a purified fraction of venom from the Malayan pit viper, Calloselasma rhodostoma, currently under investigation for treatment of acute ischemic stroke. Treatment with ancrod leads to fibrinogen depletion. The present study investigated the mechanisms leading to the reduction of plasma fibrinogen concentration. Twelve healthy volunteers received an intravenous infusion of 0.17 U/kg body weight of ancrod for 6 hours. Blood samples were drawn and analyzed before and at various time points until 72 hours after start of infusion. Ancrod releases fibrinopeptide A from fibrinogen, leading to the formation of desAA-fibrin monomer. In addition, a considerable proportion of desA-profibrin is formed. Production of desA-profibrin is highest at low concentrations of ancrod, whereas desA-profibrin is rapidly converted to desAA-fibrin at higher concentrations of ancrod. Both desA-profibrin and desAA-fibrin monomers form fibrin complexes. A certain proportion of complexes carries exposed fibrin polymerization sites EA, indicating that the terminal component of the protofibril is a desAA-fibrin monomer unit. Soluble fibrin complexes potentiate tissue-type plasminogen activator-induced plasminogen activation. Significant amounts of plasmin are formed when soluble fibrin in plasma reaches a threshold concentration, leading to the proteolytic degradation of fibrinogen and fibrin. In the present setting, high concentrations of soluble fibrin are detected after 1 hour of ancrod infusion, whereas a rise in fibrinogen and fibrin degradation products, and plasmin-α2–plasmin inhibitor complex levels is first detected after 2 hours of ancrod infusion. Ancrod treatment also results in the appearance of cross-inked fibrin degradation productd-dimer in plasma.

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