Coagulation Studies of Cord Blood, with Special Reference to “Fetal Fibrinogen”

1969 ◽  
Vol 22 (02) ◽  
pp. 273-280 ◽  
Author(s):  
A von Felten ◽  
P. W Straub
Keyword(s):  
Molecular Weight ◽  
Cord Blood ◽  
Special Reference ◽  
High Molecular Weight ◽  
Degradation Products ◽  
Thrombin Time ◽  
Fibrinogen Degradation Products

SummaryThe last phase of the clotting mechanisms was investigated in cord blood of 118 mature newborns.The most prominent finding was a prolonged thrombin time, not due to heparin. It was accompanied in most cases by a low fibrinogen and in some by a gelatinous appearance of the clot and a paracoagulation of the serum. This association was found to be usually due to in vitro fibrinogenolysis with consequent appearance of fibrinogen split products.In 9 cases the prolonged thrombin time was not obviously due to fibrinogen degradation products. The possibilities of the presence of high molecular weight fibrinogen degradation products or of a special characteristic of cord blood fibrinogen leading to a delayed fibrinogen-fibrin conversion are considered.

The Fibrin Assay Comparison Trial (FACT)

2001 ◽  
Vol 85 (04) ◽  
pp. 671-678 ◽  
Author(s):  
Sybille Zips ◽  
Hanimsah Ergül ◽  
Dieter Heene ◽  
Carl-Erik Dempfle ◽  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Degradation Products ◽  
Plasma Samples ◽  
Fibrin Degradation Products ◽  
Comparison Trial ◽  
Clinical Conditions ◽  
D Dimer

SummaryAlthough D-dimer has gained widespread clinical use as a parameter for detection of in vivo fibrin formation, the issue of standardization of D-dimer assays remains to be resolved. The FACT study was performed to generate basic data for development of calibrators and standard preparations.A set of 86 samples, including plasma samples from patients with DIC, DVT, and other clinical conditions, serial dilutions of pooled plasma samples, and plasma samples containing fibrinogen- and fibrin derivatives, were distributed to 12 manufacturers of D-dimer assays.D-dimer assays differ concerning specificity for crosslinked fibrin, and preference for either high molecular weight fibrin complexes, or low molecular weight fibrin degradation products. Terminal plasmin digests of fibrin clots for calibration produce aberrant results in some assays, especially those with preference for high molecular weight crosslinked fibrin derivatives. The best conformity is achieved by the use of pooled plasma samples from patients with high levels of D-dimer antigen in plasma. In vitro preparations containing a comparable composition of fibrin derivatives to clinical plasma samples may also serve as reference material.

Studies on the Role of Fibrinolysis and Fibrinogen Degradation Products (FDP) in Analgesic Action of Morphine

1972 ◽  
Vol 28 (03) ◽  
pp. 359-366 ◽  
Author(s):  
Włodzimierz Buczko ◽  
Konstanty Wiśniewski
Keyword(s):  
Molecular Weight ◽  
Brain Tissue ◽  
Clinical Effect ◽  
Degradation Products ◽  
Analgesic Action ◽  
Fibrinogen Degradation Products ◽  
The Brain

SummaryThe role of fibrinolysis and FDP in the analgesic action of morphine in mice and rats was studied. It was shown that during activation of blood fibrinolysis, both the accumulation of morphine in the brain tissue of rats and the clinical effect of this drug were increased. Similar results were observed after morphine given simultaneously with FDP obtained in vitro. The data from the analysis of FDP carried out on Sephadex G-25 Fine columns suggest that only FDP of molecular weight of about 10,000 potentiate the action of morphine; smaller peptides decreased the action of this drug.

The Action of Brinase in Vitro and in Vivo

1975 ◽  
Author(s):  
P. J. Gaffney ◽  
K. Lord ◽  
R. D. Thornes
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Size Range ◽  
Degradation Products ◽  
Molecular Size ◽  
Human Fibrinogen ◽  
Rate Limiting Step ◽  
Rate Limiting

Brinase (an extract of Aspergillus Oryzae) was shown to rapidly digest human fibrinogen in vitro to aggregable degradation products with a molecular size range of 310,000 to 230,000 the latter fragments being more slowly digested to core fragments, Dbr and Ebr. The fibrinogen polypeptide chain susceptibility to Brinase attack was in the order Aα, γ, Bβ, Lysis of the Bβ chain seems to be the rate limiting step in the conversion of the high molecular weight fragments (MW 310,000–230,000) to the core fragments Dbr and Ebr. The conservation of NH2 terminal Tyrosine during fibrinogen digestion and the very transient existence of D dimer fragments during totally crosslinked fibrin lysis suggest that the carboxy end of the γ chain is prone to Brinase attack. The crosslinked α chains of fibrin, while resistant to plasmin, are vigorously digested by Brinase. The plasma of cancer patients being treated with Brinase contained degraded fibrinogen (lacking intact Aα chains) and their aggregates. These aggregates contained some crosslinked γ chains (γ-γ dimers) suggesting that Brinase in vivo exorcises both a lytic and coagulant effect. Thrombin mediated clots in all the plasmas examined contained no crosslinked α chains. Positive plasma ethanol gelation tests can be explained by the presence of the aggregable high molecular weight fragments observed during the in vitro lysis of fibrinogen by Brinase.

In Vitro Formation of Fibrin-Monomer Complexes in the Presence of Isotope Labelled Fibrinogen-Fibrin Degradation Products. An Agarose Gel Filtration Study

1975 ◽  
Author(s):  
F. Asbeck ◽  
van de J. Loo
Keyword(s):  
Molecular Weight ◽  
Complex Formation ◽  
Degradation Products ◽  
Gel Filtration ◽  
Agarose Gel ◽  
Fibrinogen Degradation Products ◽  
Molecular Weights ◽  
Fibrin Degradation Products ◽  
Fibrin Monomer

Human citrated plasmas were mixed with purified 131I-fibrinogen and 131I-fibrinogen degradation products (FDP) or 125I-fibrin degradation products (fdp). After incubation with small amounts of thrombin (0.01–0.02 imits/ml Pl.), these mixtures were gel filtrated on Biogel A5m columns and the elution patterns of the 131I- and -labelled materials were determined.In control experiments without thrombin incubation, no complex formation between fibrinogen, FDP or fdp in citrated plasmas could be detected. This was even true for fdp with a higher molecular weight than fibrinogen.After thrombin incubation, up to 11% fibrin-monomer complexes were formed. Irrespective of their molecular weights, labelled fdp were not incorporated into these complexes.Only large FDP – presumably derivative X – did partially copolymerize with fibrin-monomer complexes in citrated plasmas.

Effect of fibrin-fibrinogen degradation products on human basilar artery preparations

1982 ◽  
Vol 56 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Richard H. Lye ◽  
Kamal S. Paul ◽  
Christine M. Forster ◽  
Eric T. Whalley ◽  
John Dutton
Keyword(s):  
Molecular Weight ◽  
Basilar Artery ◽  
Degradation Products ◽  
Contractile Activity ◽  
Threshold Concentration ◽  
Pathophysiological Mechanism ◽  
Content Type ◽  
Fibrinogen Degradation Products ◽  
Molecular Weight Fractions

✓ Experiments were performed to determine the effects of fibrin-fibrinogen degradation products on the human basilar artery in vitro. Citrated plasma and streptokinase were incubated at 37°C to produce a preparation of fibrinogen degradation products. Aliquots of the incubate were obtained at 90 minutes, 48 hours, and 1 and 2 weeks after preparation, and were separated into fractions of different molecular weight (MWt), using an ultrafiltration technique. Each fraction was tested at each of the above times for contractile activity and possible interaction with a threshold concentration of 5-hydroxytryptamine (5-HT) on the human basilar artery. Contractile activity was initially confined to the 90-minute aliquot fraction MWt > 100,000, but as the incubation proceeded, such activity was also seen in the lower MWt fraction < 100,000 > 10,000 at all time intervals. This activity was never seen in the fraction MWt < 10,000 at any time. Enhancement of the 5-HT response was initially confined to the higher molecular weight fractions, but after 48-hour incubation all fractions showed this activity. It is suggested that products of fibrin-fibrinogen degradation may be involved directly or indirectly in influencing the pathophysiological mechanism(s) responsible for cerebral arterial spasm following subarachnoid hemorrhage.

The Measurement of Heparin

1973 ◽  
Vol 30 (03) ◽  
pp. 471-479 ◽  
Author(s):  
K. W. E Denson ◽  
John Bonnar
Keyword(s):  
Degradation Products ◽  
Factor Xa ◽  
Assay Method ◽  
Thrombin Time ◽  
Fibrinogen Degradation Products ◽  
Low Levels

SummaryA method for the measurement of heparin utilising the potentiating effect of heparin on the action of anti-factor Xa is described. The effect on the assay of platelet contamination of plasma, the presence of fibrinogen degradation products and low levels of anti-factor Xa have been studied. The assay method has been compared with the calcium thrombin time method and a group of obstetrical patients have been studied using both methods.

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

1961 ◽  
Vol 06 (01) ◽  
pp. 015-024 ◽  
Author(s):  
Sven Erik Bergentz ◽  
Oddvar Eiken ◽  
Inga Marie Nilsson
Keyword(s):  
Molecular Weight ◽  
Body Weight ◽  
High Molecular Weight ◽  
Bleeding Time ◽  
Factor Vii ◽  
Low Molecular Weight ◽  
Factor V ◽  
Coagulation Mechanism ◽  
Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

scholarly journals Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 591
Author(s):  
Bożena Grimling ◽  
Bożena Karolewicz ◽  
Urszula Nawrot ◽  
Katarzyna Włodarczyk ◽  
Agata Górniak
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Ratio ◽  
Scanning Calorimetry ◽  
Minimal Inhibitory Concentrations ◽  
Dissolution Tests ◽  
Effective Combination ◽  
The Impact ◽  
High Molecular Weight Chitosan

Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole–chitosan solid mixtures (CL–CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole–chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.

scholarly journals Identity and Origin of the ATPase activity associated with neuronal microtubules. I. The ATPase activity is associated with membrane vesicles.

1983 ◽  
Vol 96 (5) ◽  
pp. 1298-1305 ◽  
Author(s):  
D B Murphy ◽  
R R Hiebsch ◽  
K T Wallis
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
High Molecular Weight ◽  
Brain Tissue ◽  
Membrane Vesicles ◽  
Microtubule Associated Proteins ◽  
In Vitro Assembly ◽  
Microtubule Protein ◽  
Associated Proteins

Microtubule protein purified from brain tissue by cycles of in vitro assembly-disassembly contains ATPase activity that has been postulated to be associated with microtubule-associated proteins (MAPs) and therefore significant for studies of microtubule-dependent motility. In this paper we demonstrate that greater than 90% of the ATPase activity is particulate in nature and may be derived from contaminating membrane vesicles. We also show that the MAPs (MAP-1, MAP-2, and tau factors) and other high molecular weight polypeptides do not contain significant amounts of ATPase activity. These findings do not support the concept of "brain dynein" or of MAPs with ATPase activity.

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