bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the Effects of Estradiol, Progesterone, Cortisol, Thrombophlebitis, and Typhoid Vaccine on Synthesis and Catabolism of Antithrombin III in the Dog
Authors: Kobayashi N , Takeda Y 
Published: July 2018

SummaryEffects of estradiol, progesterone, Cortisol, thrombophlebitis and typhoid vaccine on the synthesis and catabolism of antithrombin III (AT) in dogs were studied, using I-125-labeled AT (I-125-AT) as a tracer. Five dogs were used for each study. A single intramuscular injection of 20 mg estradiol caused a 20% decrease of plasma AT concentration in 6 days without appreciable changes in the plasma half-lives of I-125-AT but with a significant decrease in the fractional catabolic rate of I-125-AT (j3u). A single intramuscular injection of 250 mg progesterone did not produce any appreciable changes of plasma AT concentration, the plasma half-lives of I-125-AT or j3u. On the other hand, intravenous and intramuscular injections of a total of 750 mg Cortisol caused a 17 % increase of plasma AT concentration in a day after the injections without alterations of the plasma half-lives of I-125-AT or j3u. Next, thrombophlebitis was produced in dogs by a single intravenous injection of 1 ml 90% phenol into a leg vein occluded for 1 min by a gauze tourniquet and the effects of thrombophlebitis were studied. The results indicated that it did not cause appreciable changes of plasma AT concentration, the plasma half-lives of I-125-AT or j3u. However, studies of the effects of a single intravenous injection of 3 ml typhoid vaccine showed a 25 % decrease of plasma AT concentration in a day after the injection with a moderate acceleration of the decline rate of plasma I-125-AT and a 14% increase in j3u values. Further studies in heparinized dogs showed similar effects with typhoid vaccine. These results indicate that estradiol causes a decreased rate of AT synthesis, that progesterone has no appreciable effects on AT metabolism, that Cortisol increases the rate of AT synthesis, that localized thrombophlebitis has no appreciable effects on AT metabolism and that typhoid vaccine causes an increased j3u by unknown mechanisms which is not an accelerated coagulation process.
A New Method for the Determination of Plasma Activators of Fibrinolysis
Authors: Margalit R , Gidron E , Shalitin Y 
Published: July 2018

SummaryThe term “effective activator” of plasminogen is proposed, to denote the resultant of activator-antiactivator interaction, and a method for the determination of the level of these activators is described. By adding axcess plasminogen to the euglobulin fraction of plasma the influence of the level of endogenous plasminogen and of the antiplasmin is eliminated. It is shown that the level of fibrinogen has very little bearing on the results. An effective activator unit is defined as equal to 1 CTA unit of urokinase activity on a fibrinogen-plasminogen substrate.
Binding of Collagen by Canine Blood Platelets
Authors: Kay W. W , Swanson R , Chong G , Kurylo E , Bharadwaj B. B 
Published: July 2018

SummaryThe binding of 125I-collagen (tropocollagen) by canine blood platelets occurred in a concentration-dependent manner but no saturation effect could be observed. The binding of collagen was not entirely specific for platelets since various eucaryotic and procaryotic cells quantitatively bound collagen as well or better.The temporal response to added collagen appeared to be binding, 3H-serotonin release, and finally platelet aggregation. Non-polymerizing salt-soluble tropocollagen was bound as well as acid-soluble tropocollagen, however neither 3H-serotonin release nor platelet aggregation occurred. Furthermore, the binding activity was not destroyed by treatment with collagenase, galactose oxidase and glucose oxidase, nor by periodate oxidation.Platelet aggregation closely paralleled acid soluble collagen polymerization and both events were equally inhibited by arginine; however, arginine did not interfere with collagen binding. Scanning electron microscopy revealed an unusual morphological platelet response to collagen and platelets appeared to be nucleation sites for collagen polymerization.
Binding of Anti-Actin Autoantibodies to Platelets
Authors: Bouvier Claude A , Gabbiani Giulio , Ryan Graeme B , Badonnel Marie-Claude , Majno Guido , Lüscher Ernst F 
Published: July 2018

SummaryNormal platelets incubated with anti-actin autoantibodies (AAA) (from the serum of patients with chronic aggressive hepatitis) do not show binding of these antibodies as seen by indirect immunofluorescence. AAA serum does not inhibit thrombin-induced clot retraction, despite the binding of the antibodies to platelets in the clot. Similarly, AAA serum does not affect “reversible” or “irreversible” aggregation (induced by ADP, collagen or epinephrine), despite the binding of the antibodies to platelet actin under such circumstances. AAA also bind to platelets when aggregation is inhibited by EDTA. The incubation of “reversibly” aggregated platelet with AAA results in a small but definite binding of AAA to platelets. These findings suggest that during “irreversible” and/or “reversible” aggregation, changes take place at the surface of platelets which expose the antigen at the surface of the cell.
Cyanide Insensitive Oxidase in Platelets of Newborn Infant
Authors: Del Principe D , Menichelli A , Damiano A. M , Coppola L , Sabetta G 
Published: July 2018

SummaryThe authors studied the behaviour of neonate platelet O2 consumption after the addition of pyridine nucleotide compared to adult controls.O2 consumption of neonate platelets after NADH addition was 103,2 mμmol O2/109/hr (SE = 24,74) and in adult controls 188,8 mμmol O2/109/hr (SE = 36,46).After the addition of NADPH O2 consumption was, respectively, 233,5 mμmol (SE = 46,29) and 218,3 mμmol (SE = 30,01).
Calcium Electrode – a Method for the Continuous Monitoring of the Platelet Release Reaction
Authors: Robblee Lois S , Kornstein Laura B , Shepro David 
Published: July 2018

SummaryThe calcium electrode is a convenient, inexpensive, and non-traumatic method for measuring changes in the extracellular calcium which accompanies a platelet release reaction. With this instrument, the temporal pattern of release by platelets in a buffered-saline medium following thrombin stimulation was observed as follows: an initial time lag phase, followed by a maximum release phase, and finally a slow release phase.
ADPase Activity of Normal and Atherosclerotic Human Aorta intima
Authors: Heyns A. du P , Badenhorst C. J , Retief F. P 
Published: July 2018

SummaryADP plays a key role in platelet aggregation and the enzymatic removal of this nucleotide may be important in the pathogenesis of intravascular thrombosis and atherosclerosis. Aortic intima extracts have ADPase activity and is able to remove small quantities of ADP efficiently. ADPase activity was assayed by measuring the catabolism of 2 μM 14C-ADP (final concentration) by the tissue extracts. Extracts prepared from normal, moderately and severely atherosclerotic human aorta intimas showed a significant progressive decrease in ADPase activity with increasing atherosclerosis. ADPase activity of the arch, thoracic and abdominal regions of normal aortas did not vary significantly, and thus did not correlate with the anatomical distribution of atherosclerosis. Vascular ADPase activity seems relevant in thrombogenesis since it may be a link between blood platelets and blood vessel wall interaction.
Marathon Run I: Effects on Blood Coagulation and Fibrinolysis
Authors: Mandalaki T , Dessypris A , Louizou C , Bossinakou I , Panayotopoulou C , Antonopoulou A 
Published: July 2018

SummaryBlood coagulation and fibrinolysis were assessed in 13 Finnish amateur runners aged 31 to 48, and one 65-year old taking part in a non-competitive marathon (42.2 km). After the run the mean values of partial thromboplastin time showed a very significant shortening, whereas the mean values of the prothrombin time and of plasma fibrinogen were not significantly altered. The mean values of euglobulin lysis time were significantly shorter and the mean values of fibrin degradation products increased highly significantly. After the run, protamine sulphate was positive or strongly positive in all subjects, whereas the ethanol gelation test was negative in all runners; no cryofibrinogen was detected in any participant. Thus, running a marathon race affects the haemostatic balance and activates the fibrinolytic mechanism. The effects of training and physical fitness on the above parameters are discussed.
A Method for the Measurement of Fibrinolytic Activity Based on One Dimensional Diffusion Using Small Glass Tubes
Authors: Yasukouchi Taro , Fujine Masaru , Kohn Sukehiro , Sakurama Shoki , Morioka Tokiyo , Mikami Akio , Iju Morimasa , Nakagawa Shoichi 
Published: July 2018

SummaryThe optimal conditions for the measurement of the fibrinolytic factors of plasma were examined using human and bovine plasminogen-rich fibrinogen or plasminogen-free fibrinogen as the substrates using the one dimensional diffusion method.The results were as follows:1. There was no essential difference found between using human or bovine fibrinogen.2. The levels of proactivator-plasminogen and plasminogen could be measured while using either plasminogen-rich or plasminogen-free fibrinogen. But, in using the latter, the proactivator-plasminogen level could not be measured, if a final concentration of more than 2,000 Christensen units of streptokinase were employed.3. When using plasminogen-rich fibrinogen, anti-plasmin(s) and anti-activator(s) could be measured while using urokinase and plasmin, but not while using streptokinase. However, further study should be given to the measurement of the inhibitors, when using plasminogen-free fibrinogen.
The Effect of Antithrombin III-Independent Thrombin Inhibitors and Heparin on Fibrin Accretion onto Fibrin-Coated Polyethylene
Authors: Rubens F D , Weitz J I , Brash J L , Kinlough-Rathbone R L 
Published: July 2018

SummaryProsthetic vascular grafts become coated with a layer of fibrin that contributes to graft thrombosis and occlusion. We compared the effect of antithrombin III-independent inhibitors of thrombin with heparin for their ability to prevent fibrin accretion onto a model of a vascular graft formed in vitro by coating polyethylene tubing with thrombin bound to a layer of polymerized fibrin. Equivalent antithrombin concentrations of heparin, D-Phe-Pro-Arg CH2Cl (PPACK), recombinant hirudin (r-hirudin), and Hirulog-1 were added to barium chloride-adsorbed plasma containing radiolabelled fibrinogen. Whereas, PPACK and r-hirudin persistently inhibited fibrin accretion, the inhibition by heparin was transient. Hirulog-1 had no effect on early fibrin accretion and was actually associated with enhanced accretion at 30 min (control 11.7 ± 2.0 μg fibrin/cm2; Hirulog-1, 18.4 ± 3.5 μg fibrin/cm2, p <0.001). Both Hirulog-1 and r-hirudin displaced radiolabelled thrombin from the fibrin surface. Whereas hirudin-thrombin complexes are stable, Hirulog-1 produces only transient inhibition of the displaced thrombin thereby accounting for the enhanced fibrin accretion with this anticoagulant. These studies show that the antithrombin III-independent inhibitors, r-hirudin and PPACK, are more effective inhibitors of fibrin accretion onto fibrin-coated polyethylene than heparin or Hirulog-1. In addition, they emphasize the importance of determining the ability of anticoagulants to displace thrombin from fibrin and to form stable thrombin-inhibitor complexes; lack of stability of thrombin-inhibitor complexes must be countered by levels of anticoagulant that are adequate to maintain its effectiveness.
Assessment of the Relative Contribution of Different Protease Inhibitors to the Inhibition of Plasmin In Vivo
Authors: Levi Marcel , Roem Dorina , Kamp Angela M , de Boer Jan Paul , Hack C Erik , ten Cate Jan Wouter 
Published: July 2018

SummaryIt has been shown that the most important inhibitor of plasmin is α2-antiplasmin, however, other protease inhibitors are able to inhibit this proteolytic enzyme as well. The contribution of the various protease inhibitors to the inhibition of plasmin in vivo has never been quantitatively assessed.To assess the relative contribution of the different protease inhibitors on the inhibition of plasmin we developed a series of sensitive immunoassays for the detection of complexes between plasmin and the protease inhibitors α2-antiplasmin, α2-macroglobulin, antithrombin III, α1antitrypsin and C1-inhibitor, utilizing monoclonal antibodies that are specifically directed against complexed protease inhibitors and a monoclonal antibody against plasmin.It was confirmed that α2-antiplasmin is the most important inhibitor of plasmin in vivo, however, complexes of plasmin with α2-macroglobulin, antithrombin III, α1antitrypsin- and C1-inhibitor were also detected. Particularly during activation of fibrinolysis complexes between plasmin and inhibitors other than α2-antiplasmin were detected. It was observed that during different situations the inhibition profile of plasmin was not constant e.g. in patients with diffuse intravascular coagulation plasma levels of plasmin-α1-antitrypsin and plasmin-C1-inhibitor were increased whereas in plasma from patients who were treated with thrombolytic agents complexes of plasmin with α2-macroglobulin and with antithrombin III were significantly elevated.In conclusion, we confirmed the important role of α2-antiplasmin in the inhibition of plasmin, however, in situations in which fibrinolysis is activated other protease inhibitors also account for the inhibition of plasmin in vivo. Further investigations to assess the role of the various protease inhibitors in the fibrinolytic system can be assisted by the assays described in this study.
Von Willebrand Disease: A Database of Point Mutations, Insertions, and Deletions
Authors: Ginsburg David , Sadler Evan J 
Published: July 2018

SummaryThe current system for the diagnosis and classification of von Willebrand disease (vWD) is quite complex, with more than 20 distinct variants described. Over the past few years considerable progress has been made toward an understanding of vWD at the molecular level. A small cluster of mutations within the vWF A1 homologous repeat appears responsible for over 90% of type IIB vWD. A similar cluster of mutations in the vWF A2 homologous repeat accounts for the majority of type II A vWD. By RFLP analysis, several type II vWD mutations have been shown to be recurrent on distinct haplotype backgrounds, suggesting independent genetic origins (see accompanying manuscript for a complete list of known polymorphisms). Several mutations at the N-terminus of the mature vWF subunit have been identified in association with abnormal factor VIII binding. Homozygotes for this abnormal vWF present with a hemophilia-like phenotype that is autosomal recessive in inheritance. In a small subset of patients with type III vWD large gene deletions have been identified on one or both vWF alleles. Carriers heterozygous for a deleted locus and one normal vWF gene are generally asymptomatic. Nonsense mutations and other defects resulting in loss of vWF mRNA expression from one allele have also been associated with a recessive type III vWD phenotype. No distinct molecular defect responsible for classic type I vWD has yet been defined.
A Role for von Willebrand Factor Proline Residues 702-704 in Ristocetin-Mediated Binding to Platelet Glycoprotein Ib
Authors: Azuma Hiroyuki , Sugimoto Mitsuhiko , Ruggeri Zaverio M , Ware Jerry 
Published: July 2018

SummaryMutant domains of von Willebrand factor (vWF) were constructed to determine the effects of altering net charge, and presumably conformation, within a peptide sequence (residues 694-708) previously shown to be involved in the platelet receptor glycoprotein (GP) Ib binding function of vWF. Non-conservative substitutions replaced a triplet of proline residues (proline702–704) with either a triplet of arginine (positively-charged) or aspartic acid (negatively-charged) residues. After establishing stable CHO cell transformants, we observed the secretion of covalently-linked dimeric molecules analogous to a domain with native sequence. Functional assays using immunopurified molecules revealed that the ristocetin-dependent binding to GP Ib was abolished with both charge mutants. However, in the absence of disulfide-bond dependent conformation both mutant molecules and the molecule with native sequence interacted with GP Ib. The results demonstrate that vWF proline702–704 are important for the ristocetin-mediated interaction between vWF and GP Ib, but are not essential residues of the GP Ib binding site within vWF.
Reactivated Recombinant Plasminogen Activator Inhibitor-1 (rPAI-1) Effectively Prevents Thrombolysis In Vivo
Authors: Vaughan Douglas E , Declerck Paul J , Van Houtte Elizabeth , De Mol Maria , Collen Désiré 
Published: July 2018

SummaryThe effects of human recombinant plasminogen activator inhibitor (rPAI-1) on thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) were studied in a rabbit model of jugular vein thrombosis. Two functionally distinct rPAI-1 preparations were used in these experiments, including latent rPAI-1 (~2 units of t-PA neutralizing activity per µg protein) and reactivated rPAI-1 (~150 units/µg).Simultaneous intravenous infusion over 4 h of 1.7 mg/kg of reactivated rPAI-1 (inhibitory capacity ~0.5 mg/kg rt-PA) with 0.5 mg/kg of rt-PA completely prevented lysis of a jugular venous thrombus, whereas an equivalent amount of latent PAI-1 did not significantly influence clot lysis. These findings demonstrate that reactivated human rPAI-1 efficiently neutralizes thrombolysis with rt-PA in vivo. Since previous studies have suggested that elevated endogenous levels of PAI-1 do not attenuate the thrombolytic potency of rt-PA in the endotoxin-treated model, we compared the stability of complexes formed by 125I-rt-PA with reactivated human rPAI-1 and with rabbit PAI-1 in vitro. Our findings indicate that both forms of PAI-1 form SDS-stable complexes following incubation with 125I-rt-PA. Thus, it seems likely that elevated levels of active PAI-1 can negate the thrombolytic effects of rt-PA in vivo and argues against the possibility that t-PA can dissociate from PAI-1 and have its activity restored in the presence of a thrombus. We propose that the present model may be a valuable tool in monitoring and evaluating the in vivo thrombolytic efficacy of various t-PA mutants designed to be less sensitive to the inhibitory effects of PAI-1.
Monocyte Tissue Factor Expression Induced by Plasmodium falciparum-Infected Erythrocytes
Authors: Pernod Gilles , Polack Benoît , Peyron François , Luisy Annick , Kolodié Lucien , Ambroise-Thomas Pierre , Santoro Ferrucio 
Published: July 2018

SummaryMonocytes are active elements of the host response against Plasmodium falciparum. They are able to express tissue factor and trigger the extrinsic pathway of blood coagulation the activation of which remained unclear in malaria. Our aim was to assess the tissue factor expression of purified blood monocytes stimulated by cultured Plasmodium falciparum-infected erythrocytes. Malaria parasite induced an early generation of tissue factor with a peak between 8 and 12 h of stimulation. Maximum expression was observed for parasitemia ranging from 1 to 2%. Plasmodium falciparum culture supernatants had the same effect showing the existence of a soluble factor able to induce the tissue factor expression. These data, demonstrating an activation of the tissue factor pathway by the malaria parasite, emphasize thrombin generation. Therefore, thrombin could participate in malaria pathology either in the microcirculatory blockade via platelet and fibrinogen activation or as a mitotic.
Multicenter Evaluation of Three Commercial Methods for Measuring Protein S Antigen
Authors: Tripodi Armando , Bertina Rogier M , Conard Jacqueline , Pabinger Ingrid , Sala Nuria , Mannucci Pier Mannuccio 
Published: July 2018

SummaryThis collaborative study was designed to assess the performance of commercial methods for protein S (PS) antigen measurement. Twenty-five different samples were distributed deep-frozen (24 plasmas) or lyophilized (one plasma) to five laboratories. They were analyzed blind in each laboratory by the method used locally and by three commercial methods which included two electroimmunoassays (EIA), Asseraplate-PS (Diagnostica Stago), Rellplate-S (American Diagnostica) and an ELISA system, Asserachrom-PS (Diagnostica Stago). 1. Reproducibility. Average between-laboratory coefficients of variation were 15.4%, 17.6% and 25.3% for Asserachrom-PS, Asseraplate-PS and Rellplate-S. 2. Specificity. Results of all methods showed that PS is underestimated when C4b binding protein is high. This influence was particularly evident for the ELISA Asserachrom-PS and disappeared when the antibody-antigen incubation period was prolonged to overnight. 3. Sensitivity. In all laboratories ELISA detected even the lowest PS concentration (4 U/dl), whereas the two EIAs were less sensitive (lower detection limit 14 U/dl). All methods and laboratories correctly diagnosed a plasma sample from a PS congenitally deficient patient. Conclusions. This study shows that better standardization of PS immunoassays is necessary to improve accuracy and reduce interlaboratory variability before a candidate plasma standard can be successfully calibrated in an international collaborative study.
Relationship Between Total Prothrombin, Native Prothrombin and the International Normalized Ratio (INR)
Authors: Braun P J , Szewczyk K M 
Published: July 2018

SummaryPlasma levels of total prothrombin and fully-carboxylated (native) prothrombin were compared with results of prothrombin time (PT) assays for patients undergoing oral anticoagulant therapy. Mean concentrations of total and native prothrombin in non-anticoagulated patients were 119 ± 13 µg/ml and 118 ± 22 µg/ml, respectively. In anticoagulated patients, INR values ranged as high as 9, and levels of total prothrombin and native prothrombin decreased with increasing INR to minimum values of 40 µg/ml and 5 µg/ml, respectively. Des-carboxy-prothrombin increased with INR, to a maximum of 60 µg/ml. The strongest correlation was observed between native prothrombin and the reciprocal of the INR (1/INR) (r = 0.89, slope = 122 µg/ml, n = 200). These results indicated that native prothrombin varied over a wider range and was more closely related to INR values than either total or des-carboxy-prothrombin. Levels of native prothrombin were decreased 2-fold from normal levels at INR = 2, indicating that the native prothrombin antigen assay may be a sensitive method for monitoring low-dose oral anticoagulant therapy. The inverse relationship between concentration of native prothrombin and INR may help in identification of appropriate therapeutic ranges for oral anticoagulant therapy.