bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elektronenmikroskopische Untersuchungen an normalen und agglutinierten Thrombozyten
Authors: Nolte A , Breddin K 
Published: June 2018

Zusammenfassung1. Rattenthrombozyten, in den Gefäßen der dem Kreislauf noch angeschlossenen Niere fixiert, und menschliche Thrombozyten, die unmittelbar nach der Blutentnahme in Glutaraldehyd fixiert wurden, zeigen gegenüber in vitro fixierten Blutplättchen deutliche Abweichungen.2. Plättchenaggregate und -agglutinate sind zwei unterschiedliche Zustandsformen zusammengelagerter Thrombozyten. In Aggregaten zeigen die Plättchen intakte Zellmembranen und normalen Granulomergehalt ; sie haben ihre Individualität als Einzelzelle noch bewahrt. In Agglutinaten treten Membranfusionen, -lücken, Zellverschmelzungen und Degranulierungen auf. Die Agglutinate finden sich in zwei verschiedenen Formen. Einmal bestehen sie aus degranulierten Thrombozyten mit intakten Zellgrenzen, zum ändern aus granulahaltigen Plättchenformen mit zahlreichen Membranfusionen und Zellverschmelzungen.3. Plättchenagglutinate wurden regelmäßig gefunden in plättchenreichem Plasma von Patienten mit einem abnormen Agglutinationstest, nach Zusatz des Plasmas oder Serums eines Patienten mit aktivem plättchenagglutinierendem Faktor zu den Thrombozyten von Gesunden und nach der Einwirkung von Adenosindiphosphat und normalem Plasma auf gewaschene Blutplättchen. Die mögliche Bedeutung und Entstehung von Thrombozytenaggregaten und Agglutinaten wird diskutiert.
Agglutination und Adhäsivität der Thrombozyten nach körperlicher Belastung
Authors: Breddin K , Hach W 
Published: June 2018

ZusammenfassungKörperliche Belastung führte bei 7 gesunden Versuchspersonen zu einem Anstieg der Thrombozytenadhäsivität um 70,8% des Ausgangswertes (Mittelwert). Bei 10 Personen stieg nach der Belastung die Faktor-VIII-Aktivität im Mittel um 57% an. Es ist wahrscheinlich, daß es sich hierbei um die durch Adrenalin ausgelöste Aktivierung eines Plasmafaktors handelt, der mit dem von-Willebrand-Faktor identisch ist. Dieser »Adhäsivitätsfaktor« ist nicht identisch mit dem aktiven plättchenagglutinierenden Faktor, der sich im Plasma und im Serum von Patienten mit akuten Gefäßkrankheiten findet.Nach körperlicher Belastung fand sich bei 22 von 23 Versuchspersonen kein Anstieg der Thrombozytenagglutination.Die bisher verwendeten Methoden zur Messung der Plättchenadhäsivität zeigen sowohl Veränderungen der Haftneigung selbst als auch Änderungen der Aggregations- und Agglutinationstendenz an und sollten deshalb durch Verfahren ersetzt werden, die eine Unterscheidung zwischen diesen Mechanismen möglich machen.
Rapid Determination of Antifibrinolysin (Antiplasmin) in Plasma
Authors: Nanninga L. B , Guest M. M 
Published: June 2018

SummaryA nephelometric assay of antifibrinolysin in plasma is described. This assay is based on the inhibition of fibrinogenolysis. An equation is derived to calculate the antifibrinolysin content. Only the activity of the rapid acting antifibrinolysin is obtained. The values for antifibrinolysin are given in mol/L based on a molecular weight 57.000 (1). All values are based (standardized) on the inhibition of fibrinolysin by crystalline soybean trypsin inhibitor.
A Serial Micro-Fibrinolysis Test and Its Use in Rats with Liver-Bypass
Authors: Wasantapruek S , von Kaulla K. N 
Published: June 2018

SummaryA micro-euglobulin lysis test is described for serial testing in individual rats. With the method it was shown that the rat a) responds well with a fibrinolytic reaction to carbachol, b) that a liver-bypass in this animal produces a sustained fibrinolytic reaction which c) after subsiding can be re-established by carbachol and that d) the fibrinolytic phase in rats with liver-bypass lasts longer after preceding splenectomy and adrenalectomy.
Studies on the Mechanism of Interference by Fibrinogen Degradation Products (FDP) with the Platelet Function Role of Fibrinogen in the Platelet Atmosphere
Authors: Maria Kopeć , Budzyński A , Stachurska Jolanta , Węgrzynowicz Z , Kowalski E 
Published: June 2018

Summary1. Blood platelets can be aggregated by solutions of fibrinogen preparations of different origins. Fibrinogen degradation products (FDP) obtained by plasmin digestion do not aggregate platelets.2. Preparations of FDP added to platelet suspension inhibit aggregation induced by fibrinogen,.3. FDP when added to platelet suspensions, inhibit the release of adenine nucleotides induced by thrombin, connective tissue extract, kaolin or the contact factor.4. Platelet suspensions pretreated with SKPL loose partly the ability to release adenine nucleotides after the action of inducing agents.5. Washed platelet suspensions possess the capacity to adsorb fibrinogen and FDP, the latter being adsorbed in greater amounts and bound stronger than fibrinogen.6. An attempt was undertaken to explain the observed phenomena on the basis of a general view on the molecular mechanism of platelet function.It is postulated that fibrinogen is an integral part of the platelet surface and that it is one of the determinants of the platelet surface properties. Fibrinogen is necessary for platelet aggregation by ADP and for the adequate action of the agents which initiate metabolic changes and induce the release reaction. FDP act antagonistically to fibrinogen. They inhibit ADP aggregation as well as the access to the susceptible sites on. the surface of the platelet of the agents inducing release.
In Vitro Clumping of Human Platelets by Dextran
Authors: Dhall D. P , Matheson N. A 
Published: June 2018

SummaryPlatelet aggregation in vitro by dextrans of various molecular weights has been examined in platelet rich plasma and in suspensions of human platelets with a turbidi-metric method and microscopy. Addition of dextran to platelet rich plasma and platelet suspensions causes a biphasic effect on the optical density, consisting of an immediate decrease which seems independent of the molecular weight of the dextran and a delayed, time-dependent decrease influenced by it. Microscopically, platelet aggregation by dextran corresponds more closely to the delayed decrease. Aggregation of human platelets by dextran, for which stirring is necessary, is related to the final dextran concentration, is affected by the platelet population and is not spontaneously reversible. Platelet clumping by dextran is of particular interest since dextran has been shown to possess antithrombotic properties.
Distribution of Fibrinolytic and Proteolytic Enzymes in Subcellular Fractions of Human Granulocytes
Authors: Prokopowicz J 
Published: June 2018

SummaryThe Cohn and Hirsch method was applied for preparation of human granulocyte subfractions. It was found that specific granules contained about 50-60% of the total activity of acid phosphatase, alkaline and acid protease. The activities of fibrinolytic enzymes (plasminogen, activator of plasminogen and spontaneous fibrinolytic activity) were rather equally distributed in all subfractions.A significant rise of a total fibrinolytic activity was found during fractionation. The results suggest the existence of a fibrinolytic inhibitor in the granulocytes. This suggestion was substantiated by analysing dilution curves of the plasminogen activity in the granulocyte subfractions.The inhibitor showed both “antiurokinase”, “antistreptokinase” and antiplasmin activity.On the basis of experimental data it has been suggested that plasma plasminogen may be derived from the granulocytes.
Coagulation Factors and Components of the Fibrinolytic System in Lymph and Blood in Dogs
Authors: Leandoer L , Bergentz S.-E , Nilsson Inga Marie 
Published: June 2018

SummaryThoracic duct lymph of the dog was compared with blood regarding the concentration of various coagulation factors, coagulation properties, and components of the fibrinolytic system.The recalcification time for lymph was almost twice as long as for blood. The quotients between the concentration of the coagulation factors in the lymph and blood varied considerably. For fibrinogen the lymph/blood concentration ratio was 1/3, for factor V 1/4, for factor VIII 1/4, for factor IX 2/3 and for P & P 1/2.The fibrinolytic activity in the lymph was lower than in the blood and no split products were found in the lymph. The lymph/blood concentration ratio was 1/2 for plasminogen and 2/3 for the urokinase inhibitor activity.
In Vitro Studies on a Proteolytic Enzyme from Aspergillus Oryzae (Protease I)
Authors: Ogston D , Ogston C. M 
Published: June 2018

Summary1. Protease I was found to have potent fibrinolytic activity in concentrations which exceeded the blood inhibitory capacity when tested on fibrin plates and artificial thrombi.2. Plasma inhibited the proteolytic activity of protease I to a greater extent than serum; serum had a greater inhibitory effect on protease I than on plasmin. Trasylol did not inhibit the proteolytic action of protease I.3. Protease I caused the slow formation of fibrin in plasma in concentrations which did not produce fibrinogenolysis; this effect was seen in Al(OH)3-adsorbed plasma, and was not inhibited by heparin. Protease I also shortened the recalcified plasma clotting time.4. The fibrinogenolytic action of protease I was more rapid than its fibrinolytic action both in the presence and absence of plasma inhibitors. No concentration of protease I lysed fibrin in plasma without prior destruction or conversion to fibrin of the surrounding plasma fibrinogen.5. It is concluded from these in vitro studies that protease I does not have the properties necessary for a satisfactory thrombolytic agent.
Inactivation of Tissue Thromboplastin by Ultraviolet Irradiation
Authors: Åtland S , Hvatum M , Prydz H 
Published: June 2018

SummarySolutions of partially purified tissue thromboplastin have been irradiated with UV light of different wavelengths, and the resulting reduction in the procoagulant activity has been measured. The activity decreased as an exponential function of the dose. The action spectrum obtained was closely similar to the UV absorption spectrum of the thromboplastic preparations and had a maximum between 270-290 nm. The data suggested that the reduction in the procoagulant activity was caused by absorption of radiation energy in the protein part of the thromboplastic structure.
The Influence of Fats on Blood Coagulation and Fibrinolysis
Authors: Meuwissen O. J. A Th. , Hart H Ch. , Hemel-Rupert M. S. E van 
Published: June 2018

SummaryA review of experiments described in the literature discloses a lack of agreement about the influence of nutritional fats on blood coagulation and fibrinolysis. The numerous pertinent studies yielded contradictory results even if identical techniques were used.In our investigation, 17 normal subjects were given a breakfast containing 57 g saturated fats and one containing 54 g unsaturated fats. Before and 3 hrs after ingestion of the high-fat meal, blood was collected for determination of blood coagulation and fibrinolysis. There was no demonstrable difference between the two blood samples in terms of recalcification time of platelet-rich plasma in siliconized glass, euglobulin activity, fibrinolytic activity measured by lysis of plasminogen-poor and plasminogen-rich standard clots labelled with I131-fibrinogen, “activated fibrinolysis” (measuring the antiplasmin concentration) and the susceptibility to fibrinolysis of fibrin clots prepared in a standardized manner from fasting and hyperlipaemic plasma samples.In 6 normal subjects the experiments were expanded to encompass breakfasts with 118 saturated and 117 g unsaturated fats. After these high-fat meals, too, there was no demonstrable difference in recalcification time and in the various parameters of fibrinolysis.In order to establish whether atherosclerotic patients would show a different reaction to high-fat meals, the experiments were carried out also in 17 patients suffering from severe generalized atherosclerosis. These patients were given a low-fat breakfast, one with 57 g saturated fats and one with 54 g unsaturated fats. In this group, too, there were no demonstrable differences between the preprandial and postprandial data on blood coagulation and various parameters of fibrinolysis.
Hydrolysis of L-Histidine Methyl Ester
Authors: Cole E. R 
Published: June 2018

SummaryThe hydrolysis of L-histidine methyl ester (HME) by bovine thrombin preparations has been investigated. Activation of purified bovine prothrombin in 25% sodium citrate solution resulted in the simultaneous development of fibrinogen clotting activity and of TAME and HME esterase activities. Most of the HME esterase activity was identified with fibrinogen clotting activity on sequential chromatography of activated prothrombin on DEAE-cellulose and Amberlite CG-50 resin columns, although some HME esterase activity could be demonstrated in concentrates of the autoprothrombin C fraction. The optimum pH for HME hydrolysis by thrombin was found at 7.6 in phosphate and Tris buffered reactions. Tris buffer and other amines depress HME esterase activity of thrombin, while sodium cholate accelerates the reaction. The Michaelis constant, Km, was estimated to be 0.134 M at pH 7.6 in phosphate buffer and at 37° C.
Kinetic Aspects of the Interaction of Blood Clotting Enzymes
Authors: Hemker H. C , Veltkamp J. J , Loeliger E. A 
Published: June 2018

SummaryApplication of enzyme kinetics to the results of thrombotest estimations in correlation with specific clotting factor estimations has led to the recognition of a protein moiety that occurs in plasma in vitamin K deficiency and acts as a competitive inhibitor of thrombin formation. A hypothesis is given by which the occurrence of this inhibitor is explained in terms of a biphasic synthesis of the vitamin K-dependent clotting factors.
Preparation and Standardization of a Stable AHF Plasma
Authors: Thelin G. M ,   Los Angeles, California
Published: June 2018

SummaryA stable, lyophilized AHF reference plasma has been prepared from pooled plasma from at least 50 normal healthy donors and standardized against a primary standard of fresh plasma from 20 healthy male donors aged 20 to 40. Average AHF potency of a typical lot is 98.8%, and moisture content is less than 0.5%. Under storage at -25° C, this AHF reference plasma is stable for at least 18 months. It has been used in several major coagulation laboratories, and has given consistently satisfactory and reproducible results in AHF assays.
Zum Mechanismus der Thrombozytenaggregation
Authors: Pfleiderer Th , Brossmer R 
Published: June 2018

ZusammenfassungAn normalen Thrombozyten im Plasmamilieu ist die aggregierende Wirkung von Dextransulfat und Lipidemulsionen an das Vorhandensein freier Kalziumionen gebunden. An mehrfach gewaschenen Plättchen im Puffermilieu sind jedoch beide Substanzen auch ohne Kalzium, d. h. bei Anwesenheit von 0,2% EDTA wirksam. Während EPL jegliche Wechselbeziehungen zwischen einer Lipidemulsion und Thrombozyten in Plasma verhindert, ist an mehrfach gewaschenen Plättchen eine solche Hemmung nicht mehr nachweisbar. Die Aggregation mehrfach gewaschener Plättchen in Puffermilieu läuft also bei Anwesenheit von negativen, zur Brückenbildung befähigten Makromolekülen oder von Lipiden weit unspezifischer ab als im Plasma. Bei positiv geladenen Makromolekülen zeigt sich kein Unterschied in der Aggregation gewaschener und nicht gewaschener Thrombozyten. Die an gewaschenen Plättchen erhobenen Befunde dürfen nicht ohne weiteres auf Thrombozyten im Plasmamilieu übertragen werden. Die »plasmatische Atmosphäre« könnte für die Regulation der Plättchen-klebrigkeit in vivo von Bedeutung sein.
Activity-pH Relationship and Michaelis Constants during Activation of Profibrinolysin and during Fibrinogenolysis
Authors: Nanninga L. B , Guest M. M 
Published: June 2018

SummaryThe pH dependence was investigated separately for the activation of Profibrinolysin by urokinase and for the breakdown of fibrinogen by fibrinolysin. The effects of concentration of the substrates, Profibrinolysin and fibrinogen, respectively, were investigated and Michaelis constants were estimated for both enzymatic reactions. The average concentration of Profibrinolysin in normal human plasma was found to be 1.4 × 10–6 M based on experiments with relatively pure Profibrinolysin.
Degradation of Fibrinogen by Proteolytic Enzymes
Authors: Sanchez-Avalos J , Miller S. P 
Published: June 2018

SummaryFibrinogen was subjected to enzymatic degradation by streptokinase-activated plasminogen (plasmin). There was a rapid split of the molecule into large polypeptide components. Four components were seen by electrophoresis in acrylamide gel. Two major components (D and E) were identified by Immunoelectrophoresis and immune diffusion. In addition, a minor component which arose from the slow component and is called D’ was seen.Fibrin degradation yielded a slow component that was identical with the slow component of fibrinogen, but the fast component (E) of fibrin was different from that of fibrinogen.Degradation of fibrinogen by trypsin, chymotrypsin and papain was not mediated through the plasminogen-plasmin system. The initial action of these enzymes yielded fragments which were immunologically identical and electrophoretically similar to those of plasmin, but subsequent action of chymotrypsin led to further degradation of the slow component, while the fast component was subsequently destroyed by papain.The two main components (D and E) could be identified in the plasma and serum of patients suffering from fibrinolytic disorders. The components were immunologically identical with the components produced in vitro by proteolytic enzymes.
Studies on the Hypercoagulable State
Authors: Kropatkin M. L , Izak G 
Published: June 2018

SummaryThe intravenous injection of fibrinogen was associated with a prolonged hyperfibrinogenemia in the rabbit, out of proportion to the amount of fibrinogen administered. Factors V, II, VII and X activities were found to be elevated in the plasma simultaneously.A similar pattern of changes was observed in the rabbit after the recovery period from thrombin-induced defibrination.Based on the observations reported here, it was suggested that some fibrinogen or fibrin break-down products deliver the stimulatory message to the liver for increased fibrinogen production.The possible relationship between these observations and hypercoagulable state has been discussed.
Radioimmunoassay of Fibrinogen and Its Proteolysis Products
Authors: Catt K. J , Hirsh J , Castelan D. J , Niall H. D , Tregear G. W 
Published: June 2018

SummaryThe solid-phase radioimmunoassay method has been applied to the measurement of fibrinogen. The method is extremely sensitive, being able to detect fibrinogen concentrations as low as 10 ng/ml. The immunoreactivity of fibrinogen proteolysis products differs from that of native fibrinogen, early proteolysis products showing enhanced immunoreactivity which decreases progressively with further digestion.
Kinetic Aspects of the Interaction of Blood-Clotting Enzymes
Authors: Hemker H. C , Muller A. D 
Published: June 2018

SummaryPIVKA, the circulating anticoagulant protein found in vitamin K deficiency can, on kinetical grounds, be recognized as an analogue of factor X. The existence of analogues of other vitamin K-dependent clotting factors cannot be ruled out, but need not be assumed to explain the experimental results.
Immune Reactions of Human Blood Platelets
Authors: Mueller-Eckhardt Ch , Lüscher E. F 
Published: June 2018

Summary1. Provided they are coated with gammaglobulin, polystyrene latex particles induce in washed human blood platelets the release of adenine nucleotides, aggregation and the contraction of the formed aggregates. Albumin and fibrinogen are unable to replace gammaglobulin in this reaction. Particles with a diameter of about 0.8 μ proved most effective; larger ones were inactive.2. The release of nucleotides is a fast process; it is impaired but not completely inhibited by the removal of Ca++-ions. Aggregation and contraction of the aggregates are absent without Ca++-ions.3. Normal gammaglobulin by itself has scarcely an effect upon platelets and it fixes added hemolytic complement (C’) only to a negligible extent. After the adsorption to latex it acquires strong C’-fixing properties, and becomes more reactive towards platelets. Repeated adsorption of the same gammaglobulin preparation with latex did not change this behaviour, which therefore is due to a property of the gammaglobulin itself, and not of a preferentially adsorbed, C’-activating contaminant. Treatment at pH 4 of gammaglobulin before its adsorption onto latex simultaneously abolished its effects on platelets, and on C.4. It must be concluded that the effect of opsonized latex particles upon blood platelets is unseparable from their C’activating capacity. On the other hand, the addition of C’ not only proved unnecessary; the presence of serum rather impaired the release of nucleotides by latex particles.
Evidence that Platelets May Continue to Circulate after Phagocytosis of Particles
Authors: Vegge T , Monn E , Hjort P. F 
Published: June 2018

SummaryA suspension of thorium dioxide particles was injected intravenously into rabbits, and platelets were subsequently isolated from the peripheral blood for electron microscopical studies at intervals up to 48 hrs.The injection provoked severe thrombocytopenia. Large numbers of particles adhered to the surface of circulating platelets, and many particles were phagocytosed, probably by invagination of the membrane. Gradually, the load of particles per platelet decreased, and the particles moved into the dense granules of the platelets.We conclude that phagocytosis is not necessarily a lethal event, and platelets may continue to circulate with a heavy load of particles.
Nuclear Magnetic Resonance Studies of Fibrin Polymerization
Authors: Jędrychowski A 
Published: June 2018

SummaryFibrinogen clotting has been studied by means of the spin echo technique. Magnetic transversal T2 and longitudinal T1 relaxation times were measured during fibrin formation.Human fibrinogen was clotted by means of thrombin, papain and reptilase, which were used in three different concentrations.The time relations of T2 in the studied system reflect, among others, limitation of freedom of movement of molecules of fibrinogen in the process of formation of the fibrin clot. Distinct differences were found related to the concentration and type of enzyme used to clot fibrinogen.Comparison of the results obtained by the spin echo technique with results of measurements of optical density and thromboelastographic measurements led to the conclusion that the study of relaxation times T1 and T2 provides new information relative to fibrin formation, mainly with reference to increasing rigidity of the fibrin network and binding of water in it. This information is significant in that it determines quantitatively the degree of limitation of movement of molecules in the fibrin clot and characterizes its functional value. This conclusion was confirmed by the thromboelastographic studies, which allowed correlation of the changes in T2 time with mechanical properties of the clot.
Fibrinolysis, Fibrinogen and Factor XIII in New Born Infants
Authors: Fisher Sh , Schwartz M , Gottlieb A , Yoseph N Ben , Shapiro S 
Published: June 2018

SummaryFibrinolysis and the last stage of clotting were examined in 20 healthy infants on days 1-4 after birth. Plasminogen was constantly at half its normal level: 1.2-1.4 u/ml. The euglobulin lysis was increased only on day 1 in 50% of the cases. The mean values on days 1 and 4 showed a statistically significant difference: 0.45 ± 0.20 and 0.14 ± 0.05 (t = 2.1 p < 0.05). Fibrinogen was low or low normal at birth (mean values: 230 ± 57 mg%) but increased significantly in the next days reaching a mean of 293 ± 41 mg% on day 4 (t = 3.6 ρ < 0.001). Factor XIII was normal in all cases. Increased fibrinolysis in day 1 is probably due to a high level of activator at birth and the low plasminogen and fibrinogen are probably a consequence of the physiological „immaturity” of the liver.