bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration of the Kinetics of Thrombin-catalyzed Hydrolysis of Amino Acid Ester Substrates by Sodium Cholate and Other Steroids
Authors: Cole Edmond R. 
Published: June 2018

SummaryThrombin-catalyzed hydrolysis of TAME proceeds by an initial zero-order phase which later falls off into an apparent first order reaction as substrate becomes limiting. Optimum amounts of sodium cholate not only accelerated TAME hydrolysis but also altered its kinetics to apparent zero-order to complete substrate hydrolysis. As this implies, the rate of hydrolysis in the presence of cholate was found to be independent of substrate concentration, provided concentrations of TAME and cholate were low enough to prevent precipitation of some TAME-cholate as an insoluble complex. The formation of a soluble complex composed of polymeric molecules of TAME and cholate may explain both the acceleration and the change in reaction order. Although the pH and temperature optima for TAME hydrolysis by thrombin were not altered by the presence of cholate, the degree of acceleration increased with rising pH and temperature on the ascending portion of the curves. This is believed to be due to the greater solubility of the TAME-cholate complex. The effects of cholate on thrombin-catalyzed hydrolysis of other arginine esters as well as esters of lysine, histidine and phenylalanine were also studied.Solutions of sodium desoxycholate and androsterone-3-sulfate accelerated TAME hydrolysis as did supensions of testosterone, etiocholanolone, androsterone, androsterone-3-hemisuccinate and pregnandiol-3-glucuronidate. However, isoandrosterone, progesterone, pregnandiol, estradiol, estrone, estriol, estrone-3-sulfate, cholesterol, corticosterone, hydrocortisone and hydrocortisone-3-phosphate had no significant effect on TAME hydrolysis by thrombin. The ability of the androgenic hormones to accelerate hydrolysis appeared to depend to some extent on the configuration of the substituent group at C3 and the hydrogen at C5. Androsterone-3-hemisuccinate was, like cholate, able to accelerate the hydrolysis of TAME at apparent zero-order kinetics to complete substrate hydrolysis.
Effect of Dextran on Experimental Venous Thrombosis in Rabbits
Authors: Ah-See A.-K , Arfors K.-E , Bergqvist D , Tangen O 
Published: June 2018

SummaryAn experimental model combining controlled stasis and endothelial destruction by sodium morrhuate has been used to investigate the effect of dextran on venous thrombus formation in rabbits. Dextran 70 (1 g/kg body weight in a 10% solution), given 3 hours before thrombosis induction, significantly reduced the incidence of venous thrombosis when compared to a saline control. Dextran 40 (1 g/kg body weight in a 10% solution) and dextran 70 (0.6 g/kg body weight in a 6% solution) had no significant effect under these conditions. When given 10 or 120 minutes before initiation of thrombosis none of the dosages of dextran had any preventive effect. The results indicate that the haemodynamic effects of dextran were not involved in its preventive effect in this study. The effect of dextran was probably due to a combination of an effect on platelet reactivity and a change of the structure of fibrin formed during growth of the thrombi.
Dose-response Curves in the Fibrin Plate Assay Fibrinolytic Activity of Proteases
Authors: Haverkate F , Traas D. W 
Published: June 2018

SummaryIn the fibrin plate assay different types of relationships between the dose of applied proteolytic enzyme and the response have been previously reported. This study was undertaken to determine whether a generally valid relationship might exist.Trypsin, chymotrypsin, papain, the plasminogen activator urokinase and all of the microbial proteases investigated, including brinase gave a linear relationship between the logarithm of the enzyme concentration and the diameter of the circular lysed zone. A similar linearity of dose-response curves has frequently been found by investigators who used enzyme plate assays with substrates different from fibrin incorporated in an agar gel. Consequently, it seems that this linearity of dose-response curves is generally valid for the fibrin plate assay as well as for other enzyme plate bioassays.Both human plasmin and porcine tissue activator of plasminogen showed deviations from linearity of semi-logarithmic dose-response curves in the fibrin plate assay.
Acute Deep Vein Thrombosis Treated with Porcine Plasmin
Authors: Storm O , Ollendorff P , Drewsen E , Tang P 
Published: June 2018

SummaryThe thrombolytic effect of pig plasmin was tested in a double blind trial on patients with deep venous thrombosis in the lower limb. Only patients with not more than three days old thrombi were selected for this study. The diagnosis of deep vein thrombosis was made clinically and confirmed by phlebography. Lysofibrin Novo (porcine plasmin) or placebo (porcine plasminogen) was administered intravenously to the patients. The enzyme and the placebo were delivered as lyophilized powder in labelled bottles - the contents of the bottles were unknown to the doctor in charge of the clinical administration of the trial. An initial dose of plasmin/plasminogen of 30 unit per kg body weight given slowly intravenously (1-1% hours infusion) was followed by a maintenance dosis of 15 per cent the initial dose per hour for the following 5-7 hours. In most cases a similar maintenance dosis was given the next day. In all patients heparin was administered after ending the plasmin/plasminogen infusion. The results of the treatment was evaluated clinically as well as by control phlebo- grams the following days.A statistically significant improvement was found in the plasmin treated group compared with the placebo (plasminogen) treated group. Thrombolysis was obtained clinically and phlebographically in 65 per cent of the plasmin treated group, but only in 15 per cent of the control patients were improvements found.This study has thus demonstrated that plasmin treatment according to a standard scheme was able to induce thrombolysis. There were only a few and insignificant side effects. Allergic reactions have not been seen and only very simple tests are required.
Efleet of Endotoxin on the Activity of Coagulation Factors VII, VIII and IX Produced during Organ Perfusion
Authors: Dodds W Jean , Evensen Stein A. 
Published: June 2018

SummaryThe effect of bacterial endotoxin on the production of factor VII, VIII and IX activities in isolated rabbit livers, spleens and kidneys was investigated. The organs were perfused for 4 hours with fluid devoid of coagulation activity and containing either endotoxin or glucose-saline diluent. A series of parallel experiments included an initial hour of perfusion to ensure removal of tissue-stored coagulation activity, and perfusion with platelet-rich plasma and protein synthesis inhibitors. Endotoxin increased factor VII production in all organs but especially in livers not subjected to the initial perfusion; this effect was abolished by actinomycin D and puromycin. Endotoxin had little effect on hepatic factor VIII and IX activities but it inhibited production of both factors in the kidney and of factor VIII in the spleen. Initial perfusion prevented this inhibition of splenic factor VIII activity. These data suggest that endotoxin increases factor VII synthesis and causes consumption of factors VIII and IX in perfused kidneys and, to a lesser extent, spleens. Also, initial perfusion appears to prevent the subsequent consumption of splenic factor VIII by endotoxin. This response may involve activation of some tissue-bound or stored factor(s) or may be due to removal of an inhibitor substance.
Severe Factor V Deficiency with Prolonged Bleeding Time
Authors: Bkeederveld Kees , van Royen Eric A. , ten Cate Jan W. 
Published: June 2018

SummaryA patient with two congenital defects, i.e. a severe factor V deficiency and an aortic coarctation is described. Arguments for a dominant mode of inheritance of the factor V deficiency are presented. A coinciding haemostatic defect consisting of a prolonged bleeding time, which could be corrected by fresh plasma and cryoprecipitate, and a decreased platelet retention in the glass bead test disappeared after surgical correction of the coarctation.Extensive platelet studies failed to show any further defect.
Lysosomal Enzyme Activities in Platelets of Normal Individuals and of Patients with Gaucher’s Disease
Authors: Yatziv S , White M , Eldor A 
Published: June 2018

SummaryFive platelet lysosomal enzyme activities were estimated in 22 normal individuals and in 5 patients with Gaucher’s disease: ß-D-galactosidase, N-Acetyl-ß-D-glucosa-minidase, N-Acetyl-ß-D-galactosaminidase acid-phosphatase, and ß-D-glucuronidase.In the 5 patients with Gaucher’s disease the specific activities for the first four of these enzymes were significantly higher than in normal individuals. The activity of acid-phosphatase, on the other hand, was lower in G. d. than in normals. The release of the 5 lysosomal enzymes from platelets upon incubation with thrombin was also examined in the same two groups. The only lysosomal enzyme that was not released from normal platelets was acid-phosphatase. In Gaucher’s patients, on the other hand, acid-phosphatase was invariably released from platelets when incubated with thrombin. The release of the other four enzymes from platelets of Gaucher patients was similar to that of normal controls.
Frog Thrombocytes Aggregation and the Release Reaction
Authors: Stiller Ronald A. , Belamarich Frank A. , Shepro David 
Published: June 2018

SummaryFrog thrombocytes were shown to aggregate in response to thrombin, collagen, and adenosine triphosphate (ATP). Microscopic observations indicated that collagen and thrombin induced aggregates were cell-to-cell in nature and not due solely to passive adherence to collagen or fibrin strands.The ability of ATP to promote aggregation suggested that the release of this nucleotide might be the mechanism by which frog thrombocytes aggregate ; however, there was no evidence to support this hypothesis. Enzymatic hydrolysis of ATP by hexokinase had no effect on thrombin-induced aggregation, and ATP could not be identified in the supernatants of aggregated thrombocytes. Nevertheless, the ability of these cells to aggregate in response to these aggregating agents indicates that significant parallels may exist between platelet aggregation and the aggregation of non-mammalian thrombocytes.
Structure-Activity Relationships for the Inhibition of Plasmin and Plasminogen Activation by Aromatic Diamidines and a Study of the Effect of Plasma Proteins on the Inhibition Process
Authors: Geratz J. D 
Published: June 2018

Summary1.	Structure-activity relationships for the inhibition of human plasmin were established for a large series of aromatic diamidines. The compounds are reversible competitive inhibitors and block the amidase and fibrinolytic activities of the enzym. The results confirm pentamidine (4,4’-diamidino α ω-diphenoxy-pentane) as the leading inhibitor (Ki = 3.3 (μM) and show distinct differences in the inhibitory spectrum of diamidines against plasmin as compared with trypsin, pancreatic kallikrein and thrombin.2.	Diamidines are potent inhibitors of the SK-dependent activation of human plasminogen and of the activation of bovine plasminogen by the SK-human plasmin activator complex. Pentamidine is again the most powerful inhibitor of these systems.3.	In fibrinolytic assays of plasmin and in plasminogen activation tests the relative strength of diamidines as compared with E-ACA is greatly influenced by the test conditions. The decisive factor is the presence in the incubation mixtures of lesser or greater amounts of plasma or serum proteins which bring about a fall in the absolute strength of diamidines and an increase in the absolute strength of E-ACA. In the fibrinolytic assay of plasmin, this modifying effect of added serum is based on a time- dependent interaction with the enzyme, thereby presumably altering its susceptibility to inhibition.
Calibration of Five Different Thromboplastins, Using Fresh and Freeze-dried Plasma
Authors: Bangham D. R , Biggs R , Brozović M , Denson K. W. E 
Published: June 2018

SummaryThe results of this trial confirmed that the five different thromboplastin preparations could be calibrated in terms of thromboplastin 67/40 (2) in respect to their sensitivity to coumarin induced defect.Using thromboplastin 2 (67/40) as reference and assigning to it, by definition, a TSR of 2.0, the other four thromboplastins can be assigned the following TSRs: thromboplastin 1 (69/223) 1.9: thromboplastin 3 (68/434) 2.0; thromboplastin 4 (70/115)2.0; and thromboplastin 5 (70/178) 1.5.In view of the great amount of collaborative work which has been invested in the study of these preparations, they should be kept primarily for the purposes of calibrating other reference preparations rather than be consumed as working standards. Thromboplastin 67/40 should be preserved for calibrating future batches of an international reference material or of national reference preparations of a similar type. The other four preparations could be used to calibrate similar types of thromboplastin: human brain without added bovine factors (69/223) for calibration of similar human thromboplastins; the bovine thromboplastin (68/434) for bovine preparations, and the two different rabbit brain preparations (70/115) and (70/178) for calibration of the rabbit brain reagents. In this manner each of the preparations would be compared to a material of the same species and similar type, and the stocks of these materials conserved to last over a longer period of time.Carefully prepared freeze-dried pooled plasma from patients on oral anticoagulants can be used instead of a large number of individual fresh plasmas to simplify the calibration procedure of selected thromboplastins.In the present state of knowledge about the coumarin induced coagulation defect, artificially prepared abnormal plasmas appear to have little use in the calibration of thromboplastin preparations for control of anticoagulant therapy.
Neuraminidase Injections in Rabbits
Authors: Grøttum A. K , Jeremic M 
Published: June 2018

SummaryTwo types of neuraminidase from CL perfringens were injected intravenously in rabbits. Blood platelet electrophoretic mobility was markedly reduced 4 hours after the injection of the enzyme. A marked thrombocytopenia developed gradually with a mean lower level of 55 and 27% of the preinjection number 48 hours after the injec- - tion. White blood cell count and factors V and VIII were reduced.The results indicate that rabbit platelets with a reduced surface charge5 due to cleavage of sialic acid from the platelet membrane, are not immediately aggregated, trapped or destroyed in vivo. We suggest that the enzyme-induced platelet membrane changes rendered the platelets more susceptible to destruction in the reticuloendothelial system with appearance of thrombocytopenia after some hours.
Intravascular Coagulation in Experimental Acute
Authors: Wardle E. N 
Published: June 2018

SummaryThe occurrence of intravascular coagulation and fibrin deposition in the kidneys in situations known to produce acute renal failure has been assessed quantitatively by radio-fibrinogen studies. Apart from the Shwartzman reaction a primary process of fibrin deposition in the kidneys due to intravascular coagulation has been found in glycerol haemoglobinuric nephrosis, BSA glomerulonephritis and some cases of placental abruption and tourniquet shock, and as a secondary process in mercuric chloride intoxication. Fibrin in glomeruli may explain in part the oliguria of acute renal failure and fibrin deposition in the peritubular circulation be the cause of tubular necrosis. Inhibition of fibrinolysis in the course of the defibrination of glycerol nephrosis and placental abruption actually caused renal cortical necrosis.
Molecular Variant of Factor VII
Authors: Briët Ernest , Loeliger Emil A. , van Tilburg Nico H. , Veltkamp Jan J. 
Published: July 2018

SummaryTwo patients with severe factor VII deficiency appeared to be different with respect to the presence of inactive factor VH-like material in their plasma.The inactive material, demonstrated in one patient’s plasma and adsorbable onto BaSO4, inhibits the thrombotest-system and is capable of neutralizing a heterologous antibody against factor VII in a fluid phase system.
The Clotting of a Snake (Crotalus Viridis Helleri) Plasma and its Interaction with Various Snake Venoms
Authors: Denson K.W.E 
Published: July 2018

SummaryThe clotting of C. V. Helleri plasma is not accelerated by the factor X activator or throm-bin-like enzymes from its own venom. Clotting of the plasma is accelerated by the factor X activator from Russell’s viper venom, but not by the thrombin-like enzyme from Agkistrodon Rhodostoma venom (“Arvin”).The prothrombin activator from the Taipan venom clots C. V. Helleri plasma equally well as human plasma, but the thrombin which is produced has a marked specificity for its own fibrinogen, and clots bovine fibrinogen more slowly.C. V. Helleri plasma contains an inhibitor which progressively inactivates bovine factor Xa and thrombin, but the inhibitor is not potentiated by heparin. The slow, protracted clotting of the snake plasma either alone or when mixed with human plasma or bovine fibrinogen suggests that this inhibitor may interfere with the polymerisation of fibrin monomer.
Increased Protein Synthesis by Human Platelets during Phagocytosis of Latex Particles in Vitro
Authors: Bessler Hana , Agam Galila , Djaldetti Meir 
Published: July 2018

SummaryA three-fold increase of protein synthesis by human platelets during in vitro phagocytosis of polystyrene latex particles was detected. During the first two hours of incubation, the percentage of phagocytizing platelets and the number of latex particles per platelet increased; by the end of the third hour, the first parameter remained stable, while the number of latex particles per cell had decreased.Vincristine (20 μg/ml of cell suspension) inhibited platelet protein synthesis. This effect was both time- and dose-dependent. The drug also caused a decrease in the number of phagocytizing cells, as well as in their phagocytotic activity.
Treatment of Amyloidosis Associated Factor X Deficiency
Authors: Spero Joel A. , Lewis Jessica H. , Hasiba Ute , Ellis Lawrence D. 
Published: July 2018

SummaryThis is the tenth patient in thirteen years to be reported with the findings of an isolated factor X deficiency associated with primary amyloidosis. A favorable response to factor IX concentrate was manifested by temporary clinical and laboratory correction of her diathesis. This mode of treatment, therefore, provides an approach to therapy for bleeding complications in this group of patients who have previously failed to respond to fresh frozen plasma.
The Dissociation of Factor VIII by Reducing Agents, High Salt Concentration and Affinity Chromatography
Authors: Peake I. R , Bloom A. L 
Published: July 2018

SummaryIncubation of a factor Vlll-rich fraction of plasma with a high concentration of salt confirmed the production of both high (HMW) and low (LMW) molecular weight factor VIII clotting activity (FVIIIC) as determined by agarose gel filtration but with considerable overlap. The electrophoretic mobility of factor VIII related protein (FVIIIRP) detected by precipitating rabbit antiserum was not affected by this treatment and LMW FVIIIC devoid of FVIIIRP was apparently produced. At low concentration the reducing agent dithiothreitol (DTT) altered the electrophoretic mobility of FVIIIRP. At higher concentrations it altered both its mobility and antigenicity and an LMW FVIIIRP was produced. Contrary to the findings of other workers no LMW FVIIIC devoid of FVIIIRP was produced. In further studies factor Vlll-rich plasma fraction was treated with sepharose beads to which had been coupled a non-coagulation inhibitory precipitating rabbit antibody to FVIIIRP. Both FVIIIRP and FVIIIC were taken up by the beads but after elution with 1.5 M NaCl, FVIIIC of LMW and devoid of FVIIIRP was selectively removed. Antisera raised to LMW FVIIIC produced with 1.5 M NaCl either by the gel filtration or affinity chromatography methods inhibited FVIIIC and precipitated with HMW factor Vlll-rich fractions. The results were consistent with the possibility that factor VIII clotting activity and FVIIIRP exist in plasma as a non-covalently bound complex.
Reactivity of Fibrinogen Crosslinking Sites in the Absence of Thrombin
Authors: Seelich Thomas , Furlan Miha , Beck Eugen A. 
Published: July 2018

SummaryThe reactivity of fibrinogen crosslinking sites with thrombin-free, preactivated factor XIII (F. Xllla) was investigated under different conditions such as increased ionic strength, presence of urea, protamine sulfate (PS) or of varying concentrations of monodansylcadaverine (MDC). Crosslinking and incorporation of MDC into fibrinogen or fibrin γ- and α-chains were evaluated by SDS-Polyacrylamide gel electrophoresis.According to our results, rates of crosslinking of, and of MDC incorporation into, both γ-and α-chains of fibrinogen were low under physiological conditions; they were not significantly influenced by the presence of either 1.0 M NaCl or 1.0 M urea. In contrast, 0.01 % PS precipitated fibrinogen, and, simultaneously, significantly increased the rates of crosslinking and of MDC incorporation into both γ- and α-chains. MDC, at concentrations above approximately 6 mM, also precipitated fibrinogen, and, up to a concentration of about 9 mM, markedly enhanced the reactivity of acceptor crosslinking sites.Our results suggest that solubility of fibrinogen and the conformational arrangement of its subunit chains are closely interdependent; the reactivity of crosslinking sites with F. Xllla seems to be a function of this conformational state.
Action of Coagulation Factors on Experimental Thrombogenesis and Their Changes after Thrombosis
Authors: Marbet G. A , Duckert F 
Published: June 2018

SummaryThe action of ellagic acid, serum and acetylsalicylic acid on the frequency of thrombosis has been studied in a modification of the thrombosis model of Blake et al. (1959). Thrombi were formed in the external jugular veins of the rats by irritation with a formalin-methanol solution. The rate of thrombosis is highest with ellagic acid and lowest with acetylsalicylic acid. None of the groups of treated rats differed significantly from the control group. A short activation of coagulation with either ellagic acid or serum does not greatly enhance the thrombosis rate. The action of acetylsalicylic acid in the prophylaxis of thrombosis is not very convincing. Species differences may play a role.Exhaustive coagulation studies before and after operation showed in each group a specific behaviour of the coagulation factors. There were significant differences between thrombosis positive and thrombosis negative animals. With ellagic acid, however, there was no difference between animals with and without thrombosis.
A Simple Indirect Method to Evaluate Platelet
Authors: de Gaetano G , Vermylen J , Verstraete M 
Published: June 2018

SummaryA simple indirect method to evaluate platelet aggregation is described: the Clot Retraction Inhibition (CRI)-test, based on the observation that clot retraction is inhibited by previous in vitro platelet aggregation ; a highly significant correlation exists between the inhibition of clot retraction and each of the three parameters of aggregation curves which have been evaluated by turbidometry.The CRI-test is more sensitive in certain circumstances (thrombocytopenia, hyperlipaemia, contamination with red or white cells), than turbidometry.The CRI-test can also be satisfactorily performed on citrated total blood.