bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antithrombin III: Critical Review of Assay Methods. Significance of Variations in Health and Disease
Authors: Ødegård O.R. , Abildgaard U. 
Published: May 2019

Thrombin and factor Xa which are added to plasma are inactivated by At-III. The reactions are accelerated by heparin, permitting assay systems which rapidly measure At-III content of diluted plasma. Without heparin, the (slow) inactivation rate may be measured. The review of existing activity assays(fibrinogen or chro-mogenic substrates), and semiquantitative assays, will focus upon their usefulness and limitations, and to the correlation to results of immunoassay.In health, a narrow range of At-III concentration (and activity) is found. The level is low in infancy. Fertile women have on the average lower levels than men. In old age the level tends to drop. In the normal material that will be reported, one man was the propositus of a “new” family with At-III deficiency and thrombophilia. In a clinical material (n=2000), studied with amidolytic assay, subnormal At-III levels were found in hereditary deficiency, liver cirrhosis, disseminated intravascular coagulation and in some cases with acute thrombosis. Piasma samples containing soluble fibrin (positive ethanol gelation test) were classified as to the degree of hypercoagulation according to the values of other coagulation tests (grade 1-4, grade 4=DIC). The mean At-III plasma level decreased with increasing degree of hypercoagulation. Due to its high accuracy and simplicity, we have chosen the amidolytic activity assay with heparin and thrombin (Thromb. Res. 6, 287, 1975) for routine work.
Collagen-Induced Platelet Aggregation: Involvement of Endogenous Phosphorylation
Authors: Chiang T.M. , King L.E. , Kang A.H. , Phillips D.R. 
Published: May 2019

It has previously been shown that the aggregating agents, collagen, the ccl chain and the al-CB5 glycopeptide cause a decrease in the activity of adenylate cyclase and of the cAMP content, and an increase in the activity of guanylate cyclase and of the cGMP content in platelets. The present study was performed to investigate the effect of exogenous cyclic nucleotides, DBcGMP and DBcAMP, and the above aggregating agents on protein kinase(s) and phosphorylation of platelets.Platelets were loaded with radio-labelled inorganic pyrophosphate, washed, resuspended in autologous platelet-poor plasma or 0.02M Tris/0.15M NaCl/0.001M EDTA, pH 7.4, and reacted with various test agents. The phosphorylated components were separated by SDS-slab gel electrophoresis and analyzed by radioautography and densitometry.The results showed that DBcGMP and the aggregating agents stimulated endogenous phosphorylation in platelets of two components separable by SDS-electrophoresis. The phosphorylated components were protein in nature with apparent molecular weights of 42,000 and 20,000. The activity of cGMP-dependent protein kinase(s) was substantially higher than that of cAMP-dependent enzyme. Analyses of the time-course following exposure to the aggregating agents revealed that the phosphorylation of the two protein components preceded visible aggregation detectable by aggregometry. These data suggest the possibility that the aggregating effects of collagen and the derived peptides may be mediated by protein kinase(s).
Two Human Immunochemically Distinct low Molecular Fibrinolytic Inhibitors
Authors: Hedner U. , Gallimore M. 
Published: May 2019

Recently a fast reacting α2-antiplasmin (Müllertz 1972, Collen et al 1975) not identical with the inhibitor of the plasminogen activation (Hedner and Collen 1976) was described. Using the antiserum of Dr Aoki his inhibitor (Moroi and Aoki 19 76) was found to be identical with the α2-antiplasmin but distinct from the inhibitor of the plasminogen activation. Furthermore the inter-α-anti-plasmin described by Gallimore (1975) was found to contain both material reacting with the antiserum of Collen and with the antiserum against the inhibitor of the plasminogen activation. By means of specific immunoadsorption of the fraction eluted close to the plasminogen activation inhibitor by the method described 1973 (Hedner 1973) these two inhibitors have been separated into two fractions, which do not cross react immunochemically. In a caseinolytic system plasma from which the α2-antiplasmin was removed still has got an inhibitory activity against plasminogen activation. Also the α2-antiplasmin, plasminogen, activation inhibitors as well as α2-macroglobulin did not show any covariation in patients with different diagnoses. The inhibitor of the plasminogen activation did not interact with purified urokinase or plasmin but the α2-antiplasmin forms complexes both with human and porcine plasmin.Thus there seem to exist at least two different low molecular fibrinolytic inhibitors migrating as α2-globulins in human blood.
Effects of Lectins on Blood Platelets from Various Species
Authors: Tangen O. , Karlstam B. , Bygdeman S. 
Published: May 2019

Earlier it has been shown that different lectins induce a variable degree of aggregation of platelets. The present study confirmed previous data and demonstrated that wheat germ agglutinin (WGA) was very active, 1eucoagglutinin had about a tenth of the activity of WGA on a concentration basis, and Con A had a weak aggregating effect on human gel filtered platelets (GFP). Soy bean lectin did not aggregate human GFP.The fact that adenosine inhibited WGA- and leucoagglutinin-induced aggregation that WGA and Con A caused serotonin release, and that the aggregation- curves indicated platelet shape change are indications that the lectins influenced glycosyl moieties involving one or more molecules relevant to release and aggregation reaction.GFP were markedly more responsive to the lectins than platelets in plasma, probably due to interfering glycosyl groups amongst the plasma constituents.Platelets from man, rabbit, rat, cow and pig reacted differently towards the lectins, human platelets being the most reactive and bovine and porcine platelets being almost unreactive. These results pose intriguing questions regarding the glycosyl content of platelet membranes in different species and their relation to platelet release and aggregation.
Effect of Warfarin, Warfarin Enantiomers and Defibrase on Lewis Lung Carcinoma Metastasis Growth in Mice
Authors: Donati M.B. , Poggi A. , Mussoni L. , Kornblihtt L. , Gaetano G.de , Garattini S. 
Published: May 2019

The Lewis Lung Carcinoma (3LL) is a spontaneously metastasizing tumor, the development of which is eccompanied by marked hemostatic changes. Acceleration of labelled fibrinogen turnover and fibrin accumulation at the tumor and metastasis sites have been observed in 3LL bearing mice. Both the number and the weight of lung metastases were significantly lower in mice anti-coagulated with racemic sodium warfarin during the whole tumor development period (prothrombin complex activity around 20%). This treatment had less effect on the primary tumor. The anti-metastatic effect was slightly greater with larger doses of warfarin, which lowered the prothrombin complex activity to less than 5%. Continuous anticoagulation also protected the animals from pulmonary growth of blood-borne tumor emboli following intravenous injection of 3LL cells. This effect appeared to be closely associated with the anticoagulant activity of warfarin; indeed experiments performed with the resolved warfarin enantiomers showed that R-warfarin had virtually no anticlotting activity in mice and did not modify the metastatic growth of 3LL cells; the opposite was true for S-warfarin.Lung metastasis growth was increased in mice kept defibrinogenated during the whole period of tumor development by treatment with batrcxobin; in contrast, in mice kept defibrinated only during the period of metastasis growth, with or without surgical removal of the primary tumor, metastasis formation was slightly decreased. This suggests that fibrin may play different roles in various phases of metastaticspreading of the same tumor.
Diagnosis of the Prethrombotic State. Introduction
Authors: Sixma Jan J. 
Published: May 2019

The purpose of this symposium is to highlight new developments in methods that may detect patients with increased risk for arterial or venous thrombosis. Some of the techniques presented rely on the presence of changed clotting factors, fibrinogen in particular, or of released peptides. A novel approach is the use of antibodies directed specifically against complexes of inhibitors with activated factors.Blood platelets play an important role particularly in arterial thrombosis.Radio-immuno-assays have been worked out for two secretion products from platelets: platelet factor 4 and beta-thromboglobulin. Theoretically the sensitivity of these tests will be limited by the short half life of the substances. A possible useful approach is therefore the study of the properties of released platelets since it has been demonstrated that these platelets may have a normal survival. The platelet coagulant activity as predictor of thrombosis may fit in here. Other properties of released platelets such as the exposure of actin or the decreased uptake of serotonin are currently under investigation. Spontaneous aggregation in vivo or in vitro as well as a short half life of labeled platelets has been found in various thromboembolic diseases.The predictive value of various tests should be evaluated in prospective studies. An example of such an approach is given in the paper that concludes the symposium.
Platelet Survival Measurement - Clinical Results.
Authors: Genton E. 
Published: May 2019

Platelet survival (PS) time has been studied in patients in a variety of clinical circumstances associated with abnormal numbers of platelets, suspected thrombotic process, or after platelet suppressing drug administration.In conditions with thrombocytopenia, PS may differentiate decreased platelet production (ineffective thrombopoiesis or megakaryocyte hypoplasia) where PS is normal from increased destruction of platelets where PS is shortened. Increased destruction may arise from: extrinsic mechanisms, e.g. immunologic (ITP-SLE-drug reactions) or abnormal surface (diseased endothelium or foreign surface) are associated with short PS, often to extreme degrees; intrinsic platelet defect (Wiskott-Aldrich Syndrome), where autologous PS is shortened and isologous PS is normal.In thrombotic disorders, PS is shortened during active thrombosis and may be chronically shortened in conditions with recurrent thrombosis (homocystinemia, atheroslcerosis, valvular heart disease). The test may prove useful in prognosis (e.g. valvular heart disease patients with shortened platelet survival may have higher risk of embolic events than with normal PS).Only a few platelet suppressing drugs (including sulfinpyrazone and dipyridamole) affect a shortened platelet survival time. These reduce thrombosis in patients with prosthetic heart valves and silastic AV shunts, suggesting PS may identify useful drugs.Thus, PS may differentiate disease conditions associated with abnormal platelets, predict the course of patients at high risk of thrombotic complications, and identify clinically useful platelet suppressing drugs, or serve as a monitor for measuring effects of drug treatment.
Endothelium and Intimal Thickening
Authors: Stemerman M.B. 
Published: May 2019

A major hypothesis of atherogenesis ascribes endothelial damage as a causation of intimai proliferation which may, in turn, be a progenitor of arteriosclerosis. This hypothesis appears substantiated by experimental evidence varying from immunologic to mechanical damage of endothelium as a means of inducing both diffuse and focal intimai proliferation. There appears, in addition, other influences exerted by endothelial cells on the pathophysiology of intimai thickening. During intimai healing after wide spread endothelial denudation by an intraarterial balloon catheter, endothelial regrowth seems to promote regression of intimai thickening. It is not clear if this diminution of thickness is due to reduction in cells, extracellular material, or both.However, diminution of intimai thickening is not a feature of the healing process in the presence of hyperlipidemia. With widespread de-endothelialization, as described above, areas beneath regenerating endothelium are much thicker, and show a marked predisposition for the accumulation of lipid into the underlying already thickened intima. What physiologic or metabolic influences are exerted by the endothelium under these circumstances are unclear, but, the presence of endothelium may be a highly significant factor in the natural history of intimai proliferation and atherogenesis.
Gel Filtration of Plasma from Rabbits Injected with Honomeric DES-AB 125I-Fibrin and 131I–Fibrinogen
Authors: Kröhnke I. , Hahn I. , Krell W. , Müller-Berghaus G. 
Published: May 2019

We intended to study the chromatographic behaviour of soluble des-AB fibrin prepared in vitro and injected into rabbits. To prepare des-AB 1251-fibrin, purified rabbit 125I-fibrinogen was clotted by thrombin and the formed clot dissolved in Tris-buffered 3 M urea. Gel filtration of des-AB fibrin in urea through sepharose-CL 6B columns equilibrated with buffered 3 M. urea revealed monomeric fibrin. Rabbits received 131I-fibrinogen and 5 min later monomeric des-AB 125I-fibrin in urea. 30 min after injection blood was drawn and the plasma obtained filtered through sepharose-CL 6B columns eguilibrated with buffered plasma. At 20°C as well as at 37°C des-AB 125I-fibrin was eluted in the void volume in front of the 131I-fibrinogen peak. The data demonstrate that monomeric des-AB 125I-fibrin in urea injected into rabbits remains soluble in plasma. Possibly, monomerJ fibrin is converted to circulating soluble high-molecular weight fibrin aggregates or fibrin monomer changes its molecular configuration, thus showing a different gel filtration behaviour.(Supported by the Deutsche Forschungsgemeinschaft).
Tissue Localization of Fibrin Degradation Products.
Authors: Emeis J.J. , Nieuwenhuizen W. , Lindeman J. 
Published: May 2019

Tissue distribution of fibrin degradation products (FOP’s) during disseminated intravascular coagulation (DIC) is still largely unknown, since present immunohistochemical methods cannot discriminate between FDP’s and other fibrin-related material. Using tissue from rats with thrombin-induced DIC, we developed an immunoenzymehistochernical method for specific FDP-localization. This method is based on the following observations:1. FDP’s are - in contrast to fibrin - retained in ethanol-fixed tissue only; however, not in formaldehyde-fixed tissue;2, FDP’s in tissue will react with some of the antisera employed only (antisera against rat fibrinogen, FDP-D and E, and the constituent chains of fibrinogen were tested), whereas fibrinogen and fibrin will react with all said antisera.At 20-30 min after thrombin injection, FDP’s were found in the epithelial cells of kidney proximal tubules. These FDP’s were demonstrated with anti-chain antisera, though not with antisera against 0 or E, and are presumably early FDP’s derived from the α-and β-chain. Later (at 40-120 min), FDP’s were found in liver macrophages. These FDP’s proved unreactive to anti-chain antisera, but were demonstrated by anti-D or E antisera, A similar localization of FDP’s was found in human autopsy material in cases of DIC.
Binding of Platelet Factor 4 to Cultured Human Endothelial Cells
Authors: Busch C. , Dawes J. , Pepper D.S. , Wasteson Å 
Published: May 2019

Platelet factor 4(PF-4) is a product of the platelet release reaction. A well known property of PF-4 is to interact with sulphated glycosaminoglycans (CAGs), including heparin; binding to heparin leads to neutralization of the anticoagulant activity.This study was undertaken to examine the possible binding of PF-4 to monolayers of cultured human endothelial cells(EC). The EC surface has been shown to expose GAG in particular heparan sulphate. Cultures incubated at 37°C with various amounts of 125I-PF-4 bound 125I-radioactivity in a dose-dependent manner. Maximum binding was about 500 ng per 0-7 cm2 dish (0.4x106 cells). About 50% of this was associated with the cells. In the presence of 200 ug/ml of unlabelled PF-4 or 6 ug/ml of heparin the binding was less than 5%. Chondroitin-4-sulphate (30 ug/ml) had little influence on the binding.The observed EC-PF-4-binding in vitro may reflect a similar interaction in vivo. Such a phenomenon may influence the non-thrombogenic properties of the vascular lining. Furthermore it could affect the reliability of the PF-4 measurements as indicators of intravascular platelet release.
Large Scale Plasma Thawing for Factor VIII Recovery
Authors: Foster P. R. , Hunter J. , Dickson A. J. , White B. J. 
Published: May 2019

Freeze dried factor VIII concentrate of intermediate purity is widely accepted as the product of choice in the treatment of haemophilia A, yet supply of this material from National resources is inadequate. Substantial loss of factor VIII can occur during the production process and a point of major loss exists when plasma is thawed for removal of cryoprecipitate. The scale of operation is important since little or no loss occurs on small-volume thawing (i.e. 1-2ml) due to the shorter time of exposure to damaging conditions such as extremes of pH and ionic strength or enzyme attack. To overcome this the rate of thaw must be maximised within the constraint provided by factor VIII solubility, which is temperature dependent.To design a satisfactory process we have used pilot-scale equipment to study continuous thawing, utilising fluid removal for temperature control. For batch thawing of crushed plasma, at a rate of 20 1/hr, plasma temperatures ranged up to 7°C but for continuou thawing remained below 1.2°C. A thawing rate of 80 1/hr has been achieved with the temperature held below 2°C throughout. Plasma pools of up to 150 litres in volume have been handled in this way with a mean residence time of 12 minutes and this has encouraged us to design prototype equipment for use with fresh frozen plasma.
Comparative in Vitro and in Vivo Study of Various Factor VIII Preparations
Authors: Allain J.P. , Verroust F. , Soulier J.P. 
Published: May 2019

A comparison of nine commercial and non-commercial Factor VIII preparations was made. They consisted of llyophilized cryoprecipitate, 4 intermediate and 4 high purity concentrates. Protein, Fibrinogen, Factor VIII complex, IgG, anti-A and anti-B antibody levels were measured. Factor VIII:C content varied from 4-7 u/ml in cryoprecipitate, 12-31 u/ml in intermediate and 21-40 u/ml in high purity concentrates. These three categories of Factor VIII preparations can be better defined by 2 ratios: u FVIII/mg proteins and u F VIII/mg fibrinogen. They were respectively < 0.5 and < 1 in cryo, 0.5-1 and 1-3 in intermediate purity concentrates, > 1 and > 3 in high purity concentrates. The F VIII :C/F VIII : AG ratio ranged from 0.3 to 0.6 in any preparation. The F VIII:C/F VIII :VWF ratio was always lower than 1.Each preparation was injected to several classic hemophilia A patients for treatment of minor hemorrhages. The peak of activity was always found 1 hour post-injection and the recovery ranged from 80 to 105%. The Factor VIII half-life ranged from 10 to 12.5 hours. No significant differences in half-life or recovery was found, and the clinical efficacy was similar. With the exception of fibrinogen load, all products carry similar risk for hepatitis, anti-IgG immunization and hemolysis. The differences lie in the ease of injection, the price and the yield of Factor VIII from starting plasma. Nevertheless, high purity concentrates should be used when high doses are reauired for surgery or treatment of patients with inhibitor.
DDAVP Factor VIII Concentrate and its Properties in VIVO and in VITRO
Authors: Nilsson I-M. , Mikaelsson M. , Vilhardt H. , Wiechel B. 
Published: May 2019

DDAVP fraction I-0 was prepared from a plasma pool derived from 80 blood donors who had received DDAVP and tranexamic acid. A control fraction I-0 was prepared from a plasma pool from the same group of blood donors under identical conditions except for the drug treatment.The DDAVP plasma pool as well as the DDAVP fraction I-0 contained 2-3 times as much VIII:C as the controls. VIIIR:Ag increased to a lesser extent. No difference in stability of VIII:C was seen.
In vivo studies showed that infusion of the DDAVP fraction I-0 to 3 patients with severe haemophilia A caused a 2-3 times higher increase in VIII:C than after infusion of the same volume of the control fraction I-0. No difference in disappearance rate of VIII:C was seen.Both factor VIII concentrates normalised the defect in VWD.It is concluded that administration of DDAVP to blood donors prior to collection of blood increases the content of VIII:C in the ensuing factor VIII concentrate and secondly that such stimulation has no demonstrable qualitative effect on the factor VIII obtained.
ß Thromboglobulin (βTG), Platelet Factor 4 (PF4), and Fibrinopeptide A (FPA) in Patients with Porcine (PO) and Prosthetic (PR) Heart Valves
Authors: Dudczak R. , Niessner H. , Thaler E. , Lechner K. , Kletter K. , Frischauf H. , Damanig E. , Aicher H. 
Published: May 2019

βTG, PF4, FPA (all measured by RIA), platelet counts and LDH were determined in 17 patients with PO bioprostheses and 23 patients with PR heart valves. All patients with PR valves and 4 with PO were under oral anticoagulant treatment. ßTG and PF4 were significantly (p<0.001) elevated in both patient groups (Table).A strong positive correlation of βTG and PF4 (R=0.8660) was found in the patient group well as in controls. βTG and PF4 were higher in patients with PR valves than with PO valves, the difference however was not significant. NO higher levels were found in patients with a history of thramboembolism. FPA was normal in PO and PR patients. LDH levels were significantly (p<0.001) higher and platelet count lower in patients with PR valves. The data indicate that bioprostheses do not cause hemolysis or activation of the coagulation system. Elevation of platelet specific proteins support the assumption that both types of valves cause platelet damage.
Automated Microdensitometry and Protein Assays as Measures for Platelet Adhesion and Aggregation on Collagen Coated Slides Under Controlled flow Conditions
Authors: Muggli R. , Baumgartner H.R. , Tschopp B. 
Published: May 2019

Microscope slides were homogeneously coated over a length of 2 cm with a mixture of soluble and fibrillar collagen and exposed at 37°c and under laminar flow to citrated whole rabbit blood at a flow-rate of 100 ml/min. Surface coverage with platelets (adhesion) and platelet accumulations higher than about 5 μm in height (aggregation) were determined by automated microdensitometry of fuchsine stained ‘en face’ preparations. The platelet mass per unit surface was measured witha modified Lowry technique whose sensitivity was equivalent to 5×105 platelets. Platelet number, amount of protein and surface coverage with platelet accumulations correlated. After a per fusion time of 10 min thrombi up to 30 μm in height and oriented in the direction of flow had developed on the collagen coated area. Surface coverage with platelets was 75% and the amount of deposited protein 1.4 μg/mm2 (2x106 platelets/mm2). On the uncoated surface single platelets predominated; the surface coverage was 20% and the density of platelets 8x104/mm2. Acetylsalicylic acid at 100 μM decreased platelet aggregation by about 80% without affecting adhesion.The new parallel plate per fusion system offers rapid quantitation of platelet-surface and platelet-platelet interaction after exposure to flowing blood and may also be diagnostically useful.