bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytofluorometric Identification of Plasmin-Sensitive Factor XIIIa Binding to Platelets
Authors: Kreager Julie A , Devine Dana V , Greenberg Charles S 
Published: June 2018

SummaryWe have investigated the binding of blood coagulation factor XIIIa to thrombin-stimulated platelets using cytofluorometric analysis. Washed thrombin-stimulated platelets bound exoge-nously added factor XIIIa in a calcium-dependent reaction. The expression of endogenous platelet factor XIII was also detected on the surface of thrombin-stimulated platelets. When fluorescence analysis was performed based on particle size, factor XIIIa bound to the surface of greater than 95% of particles which contained more than one platelet, but only 50% of single platelets. The binding of factor XIIIa to thrombin-stimulated platelets was inhibited by plasmin. Plasmin also inhibited thrombin-dependent expression of the factor XIIIa binding site on platelets. Experiments in which thrombin-stimulated platelets were incubated with factor XIIIa in the presence of 125I-dimethyl-casein or 3H-putrescine demonstrated that platelets bear both glutamyl and lysyl substrates for factor XIIIa. Thrombin increased the expression of factor XIIIa substrates by platelets. Plasmin inhibited both the expression of factor XIIIa substrates and degraded them. The binding of factor XIIIa to thrombin-stimulated platelets and the availability of factor XIIIa substrates on the platelet surface could provide a mechanism by which factor XIIIa stabilizes the hemostatic plug by promoting crosslinking reactions between platelet membrane proteins and adhesive glycoproteins. In contrast, plasmin inhibition of factor XIIIa binding and crosslinking could disrupt hemostasis.
Antithrombin III Avranches, a New Variant with Defective Serine-Protease Inhibition - Comparison with Antithrombin III Charleville
Authors: Aiach M , Roncato M , Chadeuf G , Dezellus P , Capron L , Fiessinger J N 
Published: June 2018

SummaryA decreased plasma antithrombin activity in presence or in absence of heparin was discovered in a 47-year-old patient presenting with recurrent venous thromboembolism. The immunoreactive material (AT ΠΙ-IR) was normal. The same biological abnormalities were found in two relatives of the patient, leading to the diagnosis of hereditary qualitative AT III deficiency.The propositus’ AT III was coeluted with normal AT III from an heparin-sepharose column. An additional step of ion-exchange chromatography on a Mono Q column using a FPLC system (Pharmacia, St-Quentin en Yvelines, France) allowed the purification of a protein which was homogenous in SDS-10% polyacrylamide electrophoresis gel (PAGE). AT III purified from propositus’ plasma, normal plasma and the plasma of the patient known to have an AT III variant with defective protease binding (AT III Charleville) were compared. The specific activities measured as heparin cofactor anti thrombin or factor Xa inhibition in absence of heparin were decreased to half the normal value.Kinetic studies confirmed a decreased rate of thrombin inhibi-tion for both abnormal AT III preparations. SDS-PAGE experi-ments performed in purified system and immunoblots obtained from plasma showed that the two variants have different behaviour: in the case of AT III Charleville thrombin induced an apparent 5 Δ increase in molecular mass, probably due to a conformational change. AT III Avranches did not form stoechiometric complexes with thrombin, but was unmodified by the protease.
Blood Flow and Thrombosis
Authors: Goldsmith Harry L. 
Published: June 2018

SummaryPlatelet thrombi have been observed at bifurcations, constrictions and stenoses in the arterial tree where flow separation with accompanying vortex formation can occur. Hence, studies of the flow behavior of human blood cells in models of à vessel obstruction and a sudden expansion of a vessel lumen were carried out. These showed that the particles were subjected to first high, and then much lower shear stresses as they entered the vortices where the environment appeared favorable for the formation of aggregates.The effects of high and variable shear stress on the release reaction and aggregation of platelets were therefore studied using cells labeled with C14-Serotonin suspended in Tyrodes-albumin undergoing oscillatory tube flow for 20 min at 37° C. There was no significant release of serotonin due to flow alone, but the thrombin-induced release of C14-activity was appreciably greater in suspensions subjected to shear rates > 2000 sec-1 than in control suspensions which had been incubated at rest. The synergistic effects of the shear flow were also noted in the presence of adrenaline, which increased the release reaction, and when [Ca++] was raised above the physiological level or acetyl salicylic acid added, which inhibited the release of serotonin.
The Hemostatic Effect of Bovine Peptide-B from Fibrinogen
Authors: OSBAHR A. J 
Published: June 2018

SummaryBovine peptide-B from fibrinogen was active in the hemostasis of rat tail arterioles. The time of bleeding exhibits an inverse log proportionality to the concentration of bovine peptide-B. The peptide produced a 10-fold decrease in the time of bleeding at the highest concentration tested. Prolonged incubation of the peptide with the system was unnecessary and it appeared to participate immediately as a hemostatic agent.These findings suggest that hemostasis was due to vasoconstriction since coagulation time remained constant as the bleeding time decreased with increasing concentration of peptide-B. Bovine peptide-B is interpreted as a physiological substance which probably acts on some smooth muscle receptor.
Effects of Alpha and Beta Receptor Stimulating and Blocking Agents on Experimental Disseminated Intravascular Coagulation
Authors: Moriau M , Noel H , Masure R 
Published: June 2018

SummaryIn this experimental study on rabbits, we compare the haemostatic and histological changes observed in animals with disseminated intravascular coagulation (DIC) induced by thrombin perfusion (100 u/kg/hr during 3 hours) with or without preventive administration of alpha and beta receptor stimulating or blocking agents.Both alpha and beta receptor stimulating agents enhance the disorders induced by thrombin alone, while alpha or beta blocking agents reduce them.This favourable action is still more pronounced with the combination of these two last types of drugs.The modifications observed appear to be related to changes in platelet function.
Effect of Induced Chronic Intravascular Coagulation on Plasminogen Activator in Dogs
Authors: Sun Nora C. J. , Bowie E. J Walter , Titus Jack L. , Owen Charles A. 
Published: June 2018

SummaryPlasminogen activator activity in blood vessels of various organs was determined in three untreated (control) male dogs and in two male dogs that received a continuous infusion of canine brain thromboplastic emulsion for 2 weeks. Activator was measured by the speed and degree of lysis of fibrin films that were overlaid with slices of tissue. Depletion of vascular plasminogen activator occurred in the vena cava of treated dogs at the site of the tip of the catheter, which was surrounded by a clot. A decrease of activator was found in most organs and particularly in certain endocrine organs (thyroid, pituitary, and testis). Of organs that normally contained the most activator, the greatest depletion was found in the skin, lung, and penis. The wide variation of plasminogen activator activity in organs of normal dogs is described.
Electronic Platelet Counting after Isopycnic Differential Centrifugation A Simple Rapid and Accurate Method
Authors: De Bruyere M , Bellenot CL , Sokal G 
Published: June 2018

SummaryA semi-automatized platelet counting procedure with the use of a Coulter Counter is described. Its originality consists in providing an electronic method of counting of the platelets after a differential centrifugation of the blood sample previously diluted with a hypertonic NaCl solution (density 1.053) which is isopycnic to platelet density. This procedure allows elimination of red and white cells without loss of platelets in the supernatant. The final platelet number can be calculated without further corrections.The method is quick and does not require specially skilled technicians. A single technician can perform 40 counts in one hour. The reproductibility of the method is excellent and the coefficient of variation 2,4 %.The accuracy and feasibility of the method is also sustained by two years’ experience in an haematological routine laboratory.
Erythrocytes and Blood Coagulation
Authors: Surgenor Douglas MacN. 
Published: June 2018

SummaryThe action of intact and hemolyzed red cells in in vitro clotting systems is analyzed against the background of the clinical manifestations of red cell procoagulants in incompatible transfusions and hemolytic anemias in man and in experimental animals. It is suggested that the nature of the lesion in the stroma may be of importance in determining the biological effects.
A Prospective Comparison of Four Methods for the Diagnosis of Deep Vein Thrombosis
Authors: Wu Kenneth K. , Hoak John C. , Barnes Robert W. 
Published: June 2018

SummaryA simultaneous prospective study was undertaken to compare the accuracy, usefulness and limitations of four methods (125I-fibrinogen test, Doppler ultrasound technique, impedance phlebography and venography) for the diagnosis of acute and recurrent thrombophlebitis. We found that impedance phlebography was unreliable with an accuracy of 50% for the diagnosis of acute thrombophlebitis. The other three methods were reliable and had good correlation. Discrepancies among these methods were noted in recurrent thrombophlebitis. To determine whether the recurrence of symptomatology in these patients was due to an active process, the 125I-fibrinogen test was extremely useful since it detected acute thrombotic activity. As expected, both the Doppler technique and venography were insensitive for this purpose. We conclude that in evaluating patients with recurrent thrombophlebitis, it is important to perform an 125I-fibrinogen test which helps to avoid unnecessary anticoagulation.
Reversible and Irreversible Alterations of Human Plasminogen Indicated by Changes in Susceptibility to Plasminogen Activators and in Response to ∈-Aminocaproic Acid
Authors: Thorsen Sixtus , Kok Preben , Astrup Tage 
Published: June 2018

SummaryIncreasing concentrations of EACA produce a biphasic pattern of inhibition and enhancement of urokinase-induced lysis of bovine fibrin containing bovine plasminogen, while the inhibition of fibrinolysis induced by a porcine tissue plasminogen activator increases uniformly. The biphasic EACA pattern is also observed with human plasminogen in fibrinolytic and caseinolytic assays of urokinase. The biphasic EACA pattern produced with urokinase is related to the presence of a genuine form of plasminogen. The enhancement phase is caused by an increased rate of plasminogen activation in the presence of EACA. A brief treatment of genuine plasminogen with acid at ionic strength 0.15 results in an enhanced susceptibility to plasminogen activators and in a partial abolishment of the biphasic response. These acid-induced alterations of plasminogen seem to be reversed by acid dialysis at low ionic strength. Other preparations of plasminogen with enhanced susceptibility to activators have lost the ability to produce a biphasic pattern of inhibition and enhancement of urokinase-induced plasminogen activation in the presence of EACA and this ability does not return after acid dialysis at low ionic strength. EACA inhibits all plasmin preparations, whether prepared from genuine or altered forms of plasminogen, in the same uniform manner.Our results show that different forms of plasminogen can be identified by differences in the susceptibilities to activators, by their response to EACA, and by the reversibility or irreversibility of the alterations.
Kinin-like Activities of the Synthetic Low Molecular Weight Fragment of Fibrinogen Degradation Products
Authors: Takaki Akira , Yamaguchi Tsuyoshi , Ohsato Keiichi 
Published: June 2018

SummarySome biological properties of a synthetic peptide based on an anticoagulant peptide obtained from fibrinogen degradation products by the action of plasmin are reported. This peptide produced smooth muscle contraction without the presence of bradykinin. The contraction caused by this peptide was not modified by atropin (10-6 g/ml), hyoscine (10-6 g/ml) and tetrodotoxin (2xl0-7 g/ml). A hypotensive effect was observed following the intravenous injection of the peptide into an anesthetized rat indicating that this peptide has an action similar to that of bradykinin though less potent.
Clotting Activity of Platelet Phospholipids in Rat and Man
Authors: Gautheron P , Dumont E , Renaud S 
Published: June 2018

SummaryThe clotting activity of man and rat platelet phospholipid fractions separated by bi-dimensional TLC, resuspended in Tyrode by sonication, was studied in the recalcification (manual) and in the Stypven (recalcification plus Russell’s viper venom) clotting time (determined in a coagulometer). Phosphatidyl serine was the most active fraction to shorten the two clotting tests utilized, in both rat and man, but it was much more effective in the Stypven time. The phosphatidyl ethanolamine was the second most active fraction, in the Stypven time; this fraction was almost as active as phosphatidyl serine in both animal species. The other fractions studied (phosphatidyl inositol, phosphatidyl choline and sphingomyelin) were sligthly active or not active, depending on the experimental conditions.The clotting activity of platelet phosphatidyl serine from rat, at concentrations corresponding to platelet counts from 1 to 10 ( X105), was much smaller than this of the disrupted (sonicated) platelets from which it originated. However, the clotting activity of sonicated platelets could be completely reproduced, either at each concentration studied (Stypven time) or at a concentration corresponding to lOxlO5 platelets (recalcification time), by adding to phosphatidyl serine the other four phospholipid fractions (phosphatidyl inositol, phosphatidyl ethanolamine, phosphatidyl choline, sphingomyelin) dispersed in a homogeneous way by sonication.The feeding of a butter-rich diet to rats considerably increased the activity of each of the platelet phospholipid fractions in the two clotting tests carried out.
Action of Trypsin on Amidinated Fibrinogen
Authors: Phillips H. M , York J Lyndal 
Published: June 2018

SummaryA study of the action of trypsin on fibrinogen with lysine side chains chemically blocked by amidination was undertaken to determine whether trypsin attacks arginine or lysine linkages in fibrinogen in order to render it nonclottable. The data suggests that trypsin attacks arginine site(s).
A Haematocrit Corrected Micro Determination of the P&P-Test and Blood Clotting Factors in Capillary Blood
Authors: Petrich C , Pothmann R , Döhmen A , Voss H. v , Göbel U 
Published: June 2018

SummaryA new micro test for the determination of the P &P-test, and the factors II, V, and VII is described. The advantage of the new test is the possibility to discontinue the separation of the erythrocytes and the plasma. It only presumes the determination of the patient’s haematocrit, which is considered in the dilution of the blood sample. The results are not influenced by different haematocrits. They give excellent information on normal and pathologic coagulation activities, what is shown in three different groups of patients varying with respect to their age and partially receiving phenprocoumarol.
Heparin in the Treatment of Pulmonary Thromboembolism
Authors: Kanis John A. 
Published: June 2018

SummaryA retrospective survey of patients admitted to hospital with pulmonary thromboembolism during 1971 is reported, and the methods of treatment commonly used are compared. The outcome in these patients was also compared with those receiving supportive therapy.The use of oral anticoagulants with or without the addition of heparin for the first 72 hours resulted in a significant reduction in mortality by decreasing the incidence of further fatal thromboembolism. These regimens did not significantly decrease the total number of further thromboembolic complications. Treatment with prolonged infusion of heparin without oral anticoagulants resulted in a significant reduction of both thromboembolic morbidity and mortality.Despite the difficulties of valid comparisons between methods of treatment of pulmonary thromboembolism, it is concluded that the superiority of continuous heparin infusion justifies the need for a prospective assessment of the optimum length of treatment with heparin infusion.
The Effect of Factor XIII on Wound Granulation in the Rat
Authors: Marktl W , Rudas B 
Published: June 2018

SummaryThe effect of exogenously applied factor XIII on wound healing was studied, using a special wound granulation model. It has been found that great amounts of factor XIII are able to improve the wound granulation. The manner of application, i.e. local or intravenous, seems to be without influence. Possible connections between factor XIII and wound healing are discussed. The reason for the improved wound healing after application of great quantities of factor XIII remains unclarified.
The Resistance of Soluble Derivatives of Fibrinogen and the Sensitivity of Its Insoluble Forms to Fibrinolytic Degradation in Blood
Authors: Gurewich Victor , Nowak Andrzej , Lipinska Izabella , Lipinski Boguslaw 
Published: June 2018

SummaryThe effect of naturally induced fibrinolytic activity on fibrinogen and certain soluble and insoluble derivatives was studied. Experiments were performed on blood removed after venous occlusion of the arm and immediately after death. A previously described electrophoretic method was used by which the heterogeneity of fibrinogen can be demonstrated directly in intact plasma. It was shown that fibrinogen, soluble fibrin monomer (FM) complexes and fibrin degradation products are resistant to degradation by naturally-induced fibrinolytic activity. By contrast, rapid lysis of fibrin, protamine sulfate (PS) precipitated fibrinogen, and PS and ethanol induced gels of FM occurred. The observations are believed relevant to our understanding of the pathway of fibrinogen and FM catabolism and the interpretation of the origin of serum FDP.
Intrinsic Activation of Prothrombin Potentiated by Celite and Reduced by Kaolin
Authors: Kang E. P , Triantaphyllopoulos D. C 
Published: June 2018

SummaryPreparations of human prothrombin complex were absorbed with celite or kaolin and the 10% sodium chloride eluate of both absorbents was tested for its effectiveness to correct the prolonged partial thromboplastin time of celite-exhausted plasma. Both types of eluate were effective, indicating the presence of contact factors in the prothrombin preparations. Activation of the absorbed prothrombin complexes via the intrinsic pathway showed that while the kaolin absorbed preparations generated less thrombin than the parent solutions, celite absorbed complexes generated more thrombin than before they were absorbed. Both types of absorbed preparations generated the same amount of thrombin as before absorption when they were activated via the extrinsic pathway. When the absorption of the contact factors was performed by the addition of celite in the plasma before the purification of the prothrombin complex, the prothrombin preparations obtained generated less thrombin via the intrinsic pathway than the preparations which were obtained from plasma which had not been treated with celite.
Indirect Measurement of Streptokinase Concentration in the Plasma of Patients Undergoing Fibrinolytic Treatment
Authors: Martin M 
Published: June 2018

SummaryA new method of determining streptokinase concentrations on a quantitative basis in the plasma of patients undergoing streptokinase infusion is demonstrated. The principle of this method is based on the clot lysis time recorded by the thrombo-elastograph. The test clot constituents were bovine fibrin, bovine plasminogen, human euglobulin, EDTA, human plasma (with unknown streptokinase quantity) and thrombin. As plasminogen (euglobulin) and fibrinogen were present in the test coagulum in rather high concentrations (fixed excess) no interference with changing plasminogen and fibrinogen levels of the patient’s plasma was observed. Further, due to high EDTA concentrations, no interaction with platelet functions and coagulation factors took place. The standard error of measuring 5 u of streptokinase in one ml of human plasma was determined at s = ±0.47 u/ml.Eleven patients undergoing fibrinolytic treatment with streptokinase were monitored by streptokinase determination in the plasma. In this group of patients, streptokinase concentration values varying between 15 and 0.5 units/ml plasma were measured. One striking feature was the continuous decrease in streptokinase concentration in the plasma, in spite of unchanged streptokinase infusion rates. This observation was consistent in regimens with both large (100,000 u/h) and small (30,000 u/h) streptokinase infusion rates. No explanation is available for this observation up to now. A rise in circulating anti-streptokinase contents was precluded. Possibly, an accelerated streptokinase metabolism rate in the course of long-term streptokinase administration may be involved.
Decreased ATP, ADP and Serotonin in Young Platelets of Fawn-Hooded Rats with Storage Pool Disease
Authors: Tschopp Th B. , Weiss H. J 
Published: June 2018

SummaryThe bleeding diathesis and abnormalities of platelet aggregation in the Fawn-Hooded (FH) rat, as in human patients with storage pool disease, have been attributed to decreased amounts of adenine nucleotides that are ordinarily stored with serotonin in the platelet dense granules. This study was undertaken in order to establish whether the platelet defect of the FH rat was present in young platelets, newly emerged from the bone marrow, or whether the platelets acquired this abnormality (possibly by a premature release reaction) during their circulation in the blood. FH and Wistar rats were made thrombocytopenic with one injection of anti-platelet serum (APS) and platelets were harvested during the recovery phase. The ATP content of “young” FH platelets harvested two days after injection of APS, was higher than that of platelets obtained from untreated FH rats, but was still only 50% of that found in “young” Wistar platelets. In addition, the adenine nucleotide content of FH platelets did not change during treatment with aspirin. “Young” FH platelets were also deficient in serotonin and, unlike Wistar platelets, their serotonin content did not increase appreciably with the increasing platelet age. The results of the study strongly suggest that the defect in FH platelets is present in platelets newly emerged from the bone marrow and is not due to premature release of the “storage” contents during their circulation in the blood.
Evidence for Ca2+ Regulated Magnesium ATPase of Thrombosthenin (Platelet Actomyosin)
Authors: Mahendran C 
Published: June 2018

SummaryThe isolation of an actomyosin-like protein from platelets with a Ca2+ sensitive component is described. The addition of 1 mM EGTA results in approximately 40% and 75% inhibition of the Mg-ATPase activity depending on the mode of isolation. The inhibition can be released by a free Ca2+ concentration of 3×l0-6 M. Superprecipitation is also inhibited by 1 mM EGTA and restored in the presence of 10-5 M free Ca2+.