bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythromelalgia in Essential Thrombocythemia Is Characterized by Platelet Activation and Endothelial Cell Damage but not by Thrombin Generation
Authors: van Genderen Perry J J , Lucas Irene S , Strik Roel van , Vuzevski Vojislav D , Prins Fransisco J , van Vliet Huub H D M , Michiels Jan J 
Published: July 2018

SummaryErythromelalgia, a characteristic aspirin-responsive microvascular thrombotic complication in essential thrombocythemia (ET), may develop despite oral anticoagulant treatment or treatment with heparin, suggesting that the generation of thrombin is not a prerequisite for its development. To study this, a cross-sectional comparison of the plasma levels of thrombomodulin (TM), platelet factor 4 (PF4), β-thrombo-globulin (β-TG), prothrombin fragment 1+2 (F1+2) and total degradation products of fibrin(ogen) (TDP) was made between 5 ET patients suffering from erythromelalgia, 16 asymptomatic ET patients and 20 control subjects, and after treatment with aspirin, respectively. Furthermore, 2 ET patients with a history of erythromelalgia were studied at regular time intervals after discontinuation of aspirin until erythromelalgia recurred. As compared with asymptomatic ET patients and control subjects erythromelalgia was characterized by significantly higher β-TG and TM levels but no significant differences were detected in either F1+2 or TDP levels. Treatment of erythromelalgia with aspirin resulted in disappearance of erythromelalgic signs and symptoms, which was paralleled by a significant decrease of β-TG and TM levels. Histopathologic and immunohistochemical analysis of biopsies derived from erythromelalgic skin areas of 2ET patients showed that erythromelalgic thrombi stained positively for von Wille-brand factor opposed to only a weak fibrin staining. Our data suggest that erythromelalgia is caused by the intravascular activation and aggregation of platelets with subsequent sludging or occlusion of the acral arterial microvasculature. The generation of thrombin appears not to be essential for the formation of these platelet thrombi, thereby giving a plausible explanantion for the inefficacy of coumadin derivatives and heparin in the prevention and treatment of erythromelalgia in essential thrombocythemia.
Conjunctive Administration of Intravenous Heparin Attenuates Cross-linked Fibrin Degradation in Patients Treated with Streptokinase
Authors: Galvani Marcello , Abendschein Dana R , Ferrini Donatella , Ottani Filippo , Rusticali Franco , Eisenberg Paul R 
Published: July 2018

SummaryIncreases in thrombin activity occur in patients treated with streptokinase, but conjunctive therapy with intravenous heparin does not appear to improve either the rate of early infarct artery patency or survival in patients with acute myocardial infarction. In a recent study we found that concentrations of fibrinopeptide A, a marker of thrombin-mediated fibrin formation, were lower in the first 3 h in patients treated with intravenous heparin (5000 U bolus followed by a fixed-dose 1000 U/h infusion, n = 14) compared with subcutaneous (12,500 U every 12 h, started 4 h after streptokinase, n = 14) administration, but were increased in both groups of patients, consistent with persistent thrombin activity. To determine whether the differential effects of the intensity of heparinization on thrombin formation were reflected in differences in fibrin degradation, we measured cross-linked fibrin degradation products (XL-FDP) before and 1,2,3,8,12, and 24 h after streptokinase in the same cohort of patients, with a new ELISA with a D-dimer-specific capture antibody (MAb 3B6) and a fibrin-specific tag antibody (MAb 1D2, Agen, Brisbane, Australia). The incidence of early coronary recanalization assessed by creatine-kinase MM isoforms (increase in activity ≥0.18%/min), was similar in both groups (79 vs 86%). Concentrations of XL-FDP were similar in patients with and without recanalization, but were lower in patients treated with intravenous compared with subcutaneous heparin at 8 h, but the results did not reach statistical significance (627 ±151 ng/ml versus 1007 ± 157 ng/ ml, p = 0.06), and were significantly lower at 12 h (327 ± 72 versus 781 ± 162 ng/ml, p = 0.03 at 12 h) (mean ± SEM). Concentrations of cross-linked fibrin degradation products were also lower in patients in whom the activated partial thromboplastin time was greater than two times the control, compared with those with inadequate anticoagulation (498 ± 105 versus 1084 ± 179 ng/ml; p = 0.02) (mean ± SEM). Thus, more effective inhibition of thrombin with conjunctive intravenous heparin therapy results in less cross-linked fibrin turnover in the first 12 h after thrombolysis with streptokinase. This probably reflects decreased fibrin formation with therapeutic anticoagulation.
Cyclosporine Therapy for Acquired Factor VIII Inhibitor in a Patient with Systemic Lupus Erythematosus
Authors: Schulman S , Langevitz P , Livneh A , Martinowitz U , Seligsohn U , Varon D 
Published: July 2018

SummaryThe case of a 27-year-old woman with systemic lupus erythematosus and development of an autoantibody against factor VIII during an exacerbation of her underlying disorder is described. Attempts to eliminate the antibody with high dose gammaglobulin and repeated courses of cyclophosphamide failed, whereafter she received cyclosporine in increasing doses. When therapeutic serum levels of cyclosporine were achieved (150-350 ng/ml) the inhibitor rapidly decreased and disappeared with a concomitant normalization of the factor VIII levels. Treatment with cyclosporine was subsequently reduced and discontinued after one year, and at present no inhibitor is detectable. In view of the successful results with cyclosporine treatment in 4 of 6 previous cases and in all 3 previous cases with autoimmune disorders, this regimen should be evaluated in a systematic manner as a potential first line drug in patients with acquired hemophilia and an underlying autoimmune disorder.
Phosphatidylethanolamine Induces Specific Conformational Changes in the Kininogens Recognizable by Antiphosphatidylethanolamine Antibodies
Authors: Sugi Toshitaka , McIntyre John A 
Published: July 2018

SummaryAutoantibodies to the zwitterionic phospholipid (PL), phosphatidylethanolamine (PE) have been described in patients with thrombotic diseases. Recently, we reported that many antiphosphatidylethanolamine antibodies (aPE) are not specific for PE per se, but are directed to plasma proteins which can bind PE, for example, high molecular weight kininogen (HK), low molecular weight kininogen (LK) and/or proteins in complex with HK, factor XI or prekallikrein. In the ELISA, we now show that intact HK binds to all PL tested. By using a monoclonal antibody (mAb) to the HK light chain, binding to cardiolipin (CL) was highest followed by phosphatidylserine (PS), PE and phosphatidylcholine (PC). By contrast, LK bound best to PE, with lesser amounts binding to PC and CL. Many aPE recognize only a kininogen-PE complex and neither PE nor kininogen when they are tested independently. We now report that these aPE are specific for the kininogen-PE complex as they do not recognize the kininogens when the latter are presented on other PL substrates. This indicates that PE induces unique antigenic conformational changes in the kininogens which are not induced when the kininogens bind to other PL. The kininogens bind to platelets and endothelial cells through an as yet undefined receptor. Since PE is a normal constituent of the outer layer of cell and platelet plasma membranes, it is available for the kininogens to bind. In vitro studies showed that purified IgG which bound kininogen-PE complexes in ELISA also caused platelets to undergo irreversible aggregation when stimulated by subthreshold concentrations of bovine thrombin.
Two New Frequent Dimorphisms in the Protein S (PROS1) Gene*
Authors: Mustafa Stefan , Pabinger Ingrid , Mannhalter Christine 
Published: July 2018

SummaryTwo new polymorphisms were identified in the proteinS gene (PR0S1): an intronic T/A-dimorphism (PIPS1) in intron K, and an exonic C/A-dimorphism (PEPS2), located in the 3'untranslated trailer of exon 15. Allelic frequencies of 24% (PIPS 1-A) and 17% (PEPS2-A) respectively, were determined in the normal population. The identification of an intronic and an exonic PR0S1 dimorphism, in addition to the known BstXI dimorphism, enlarges the molecular tool box for gene analysis and transcript quantification in hereditary protein S deficiency. Haplotype analysis showed that variability of both new polymorphisms occurred almost exclusively in the A-allele of the known intragenic BstXI dimorphism. Therefore, PEPS2 and PIPS1 are especially valuable in individuals homozygous for the BstXI A-variant.
Plasminogen Activator Inhibitor 1 Is Elevated in the Children of Men with Premature Myocardial Infarction
Authors: Rallidis Loukianos S , Megalou Ageliki A , Papageorgakis Nikos H , Trikas Athanasios G , Chatzidimitriou Grammatiki I , Tsitouris George K 
Published: July 2018

SummaryTo assess whether plasminogen activator inhibitor 1 (PAI-1) activity is elevated in the progeny of young coronary men, 193 young subjects were recruited and divided into two groups. Group A consisted of 104 children whose fathers had suffered a myocardial infarction before the age of 55 (“cases”). Eighty-nine young subjects matched for age, sex, body mass index (BMI) and smoking habits without familial history of coronary artery disease (CAD) served as controls (group B). Children with a family history of diabetes mellitus or hypertension were excluded from both groups. We measured PAI-1 activity, tissue-type plasminogen activator (t-PA) antigen, a2-antiplasmin, fibrinogen, lipids and apolipoproteins in both groups. PAI-1 activity levels were also determined in the men who suffered a premature myocardial infarction 4 months after their discharge. PAI-1 activity levels were higher in cases compared to controls (3.13 ± 1.9 vs 2.17 ± 1.9 U/ml, p = 0.0014). t-PA antigen and a2-antiplasmin did not differ significantly between the two groups, while fibrinogen, total cholesterol, low-den-sity lipoprotein cholesterol, apolipoprotein B and lipoprotein(a) were significantly higher in group A. PAI-1 was positively correlated with triglycerides (r = 0.22, p = 0.024), apolipoprotein B (r = 0.21, p = 0.039) and fibrinogen (r = 0.22, p = 0.029 ) in cases and with BMI in both cases (r = 0.37, p = 0.0003) and controls (r = 0.23, p = 0.044). In stepwise multiple regression analysis, only apolipoprotein B (p = 0.008) and BMI (p = 0.0014) were significant determinants of PAI-1 activity in cases. There was also a positive correlation between PAI-1 activity levels of the affected fathers and their children (r = 0.30, p = 0.01). The present data support the hypothesis that elevated PAI-1 levels in the offspring of men with premature myocardial infarction impair their fibrinolytic capacity contributing to their familial predisposition to CAD.
Characterization of Recombinant von Willebrand Factors Mutated on Cysteine 509 or 695
Authors: Siguret Virginie , Ribba Anne-Sophie , Christophe Olivier , Chérel Ghislaine , Obert Bernadette , Rouault Christine , Nishikubo Toshiya , Meyer Dominique , Girma Jean-Pierre , Piétu Geneviève 
Published: July 2018

SummaryThe interacting domain of vWF with platelet GPIb has been shown to overlap the large A1 loop formed by the intra-chain disulfide bond linking Cys 509 to Cys 695. In order to further investigate the role of the conformation of this region, we have expressed in COS-7 cells three mutated full-length recombinant vWFs (rvWFs) in which the substitutions Cys509Gly, Cys509Arg or Cys695Gly have been introduced by site-directed mutagenesis. SDS-agarose gel electrophoresis demonstrated an impaired multimerization of the mutants with undetectable high molecular weight multimers and a decrease of the relative amounts of the intermediate sized multimers. Binding analysis showed that rvWFC509G and rvWFC509R did not interact with botrocetin but spontaneously interacted with GPIb; the latter binding remained unchanged in the presence of ristocetin. This indicates that the substitution of Cys509 by Gly or Arg creates a conformation of vWF that increases its binding to GPIb. In contrast, rvWFC695G which did not react with botrocetin was also unable to interact with GPIb even in the presence of ristocetin, indicating that sequences interacting with GPIb are masked and/or disrupted. In conclusion, the substitution of each of the Cys509 and 695 results in mutant proteins which may be “locked” into active or inactive conformations in regard to the binding to platelet GPIb receptor.
Evaluation of the Abnormal Platelet Function in von Willebrand Disease by the Blood Filtration Test
Authors: Pareti Francesco I , Cattaneo Marco , Carpinelli Luca , Zighetti Maddalena L , Bressi Caterina , Mannuccio Mannucci Pier , Ruggeri Zaverio M 
Published: July 2018

SummaryWe have evaluated platelet function in different subtypes of von Willebrand disease (vWD) by pushing blood through the capillarysized channels of a glass filter. Patients, including those with type IIB vWD, showed lower than normal platelet retention and increased cumulative number of blood drops passing through the filter as a function of time. In contrast, shear-induced platelet aggregation, measured in the cone-and-plate viscometer, was paradoxically increased in type IIB patients. Treatment with l-desamino-8-D-arginine vasopressin (DDAVP) tended to normalize the filter test in patients with type I-platelet normal and type I-platelet low vWD, but infusion of a factor VUI/von Willebrand factor (vWF) concentrate lacking the largest vWF multimers was without effect in type 3 patients. Experiments with specific monoclonal antibodies demonstrated that the A1 and A3 domains of vWF, as well as the glycoproteins Ibα and Ilb-IIIa on platelets, are required for platelet retention in the filter. Thus, the test may reflect vWF function with regard to both platelet adhesion and aggregation under high shear stress, and provide relevant information on mechanisms involved in primary hemostasis.
Haemostatic Studies in Carbohydrate-deficient Glycoprotein Syndrome Type I
Authors: Fiumara A , Barone R , Buttitta P , Musso R , Pavone L , Nigro F , Jaeken J 
Published: July 2018

SummaryCDG syndrome (CDGS) type I is the most frequent form of a group of metabolic disorders characterised by a defect of the carbohydrate moiety of glycoproteins. A large number of plasma glycoproteins, including clotting factors and inhibitors, are decreased and stroke-like episodes have been described in about half of the reported patients. We studied blood coagulation factors, inhibitors and D-dimer plasma levels in four subjects, aged 12-23 years, with CDGS type I. Factors VIII, XI, antithrombin III activity, antigen plasma levels of antithrombin III, free protein S and protein C were decreased whereas protein C as activity was normal. In addition two patients had reduction of factors II, V, VII, IX, X reflecting the phenotypic heterogeneity associated with CDGS type I. D-dimer plasma concentrations were elevated in all subjects. The hypercoagulable state as consequence of the combined deficiencies of coagulation inhibitors could contribute to the stroke-like phenomena in CDGS type I.
Characterization of Cellular Binding Sites and Interactive Regions within Reactants Required for Enhancement of Plasminogen Activation by tPA on the Surface of Leukocytic Cells
Authors: Félez Jordi , Miles Lindsey A , Fabregas Pere , Jardi Merce , Plow Edward F , Lijnen Roger H 
Published: July 2018

SummaryPlasminogen and tPA bind to a common set of binding sites on nucleated cells. To assess the functional consequences of cellular binding, we have measured the kinetic changes induced by plasminogen activation by tPA on cell surfaces. These studies were carried out with U937 and THP-1 monocytoid cells, with Raji, Nalm6 and Molt4 lymphoid cells and with peripheral blood monocytes and neutrophils. The interactions of plasminogen and tPA with cells induced an increase in the rate of plasmin generation which depended upon the cell concentration. With saturating amounts of U937 monocytoid cells (1.25 × 105/ml) the rate of plasmin generation was 0.39 nM.s-1 versus 0.07 and 0.09 nM.s-1 without cells or without tPA, respectively. The catalytic efficiency of Glu- or Lys-plasminogen activation by tPA increased by 7.2- and 24.2-fold, respectively. These changes were induced by a 72-242-fold reduction in the Km of these interactions which was in the range of 0.3-0.9 µM. These values are below the plasminogen concentration in plasma (1-2 µM). Moreover, we provide new data indicating that 1) only a specific subset of plasminogen binding sites, i.e. molecules exposing carboxyl terminal lysines on the cell surface, promotes plasminogen activation on cells; 2) the first four kringles of plasminogen and the finger of tPA are critical for enhanced plasmin generation on cell surfaces; 3) the simultaneous co-localization of tPA with plasminogen on cell surfaces is required for enhanced plasminogen activation; 4) modulation of plasminogen/tPA receptor expression induces concomitant modulation of the stimulatory effects of cells on plasminogen activation and 5) in a direct comparison, the mechanism by which cells and fibrin fragments accelerate plasminogen activation are similar but not identical. These data suggest that modulation of plasminogen/tPA binding sites permits local and efficient generation of plasmin on cell surfaces.
Recombinant Full-length Tissue Factor Pathway Inhibitor (TFPI) Prevents Thrombus Formation and Rethrombosis after Lysis in a Rabbit Model of Jugular Vein Thrombosis
Authors: Kaiser Brigitte , Fareed Jawed 
Published: July 2018

SummaryIn the jugular vein of rabbits thrombus formation was induced by vessel wall damage using a balloon catheter and following reduction of blood flow by 80-90% for 60 min (partial stasis). The blood flow in the vein was measured continuously and the incidence of primary thrombus formation, the time until lysis with recombinant tissue-type plasminogen activator (rt-PA) as well as the incidence of rethrombosis after lysis were determined. At the end of the experiment the wet weight of the thrombus formed inside the vessel was measured. For the determination of haemostaseological parameters blood was drawn from the cannulated femoral artery.Recombinant full-length tissue factor pathway inhibitor (TFPI) was studied with regard to its effect both on primary thrombus formation and on rethrombosis after lysis. In control animals damage of the vessel wall combined with partial stasis led to the formation of occlusive venous thrombi. In vitro bolus injection of TFPI (5,10,20 Μg/kg) at the time of thrombus induction prevented the formation of venous thrombi during the 1 h period of partial stasis. In the subsequent observation period a dose-dependent inhibition of later occurring partial or complete thrombotic occlusion was found. At the dose of 20 Μg/kg i.v. in all animals TFPI prevented a complete thrombotic occlusion of the vein up to 3 h after stasis. To study the effectiveness of TFPI on rethrombosis after lysis TFPI was injected i.v. after lysis of the thrombus with rt-PA (600 Μg/kg i.v. bolus + 600 Μg/kg i.v. infusion over 60 min). In saline treated control rabbits a reocclusion of the vessel was seen in 8 of 10 animals. TFPI (10, 20, 40 Μg/kg i.v.) injected at the end of rt-PA administration caused a dose-dependent inhibition of thrombotic reocclusion after lysis. At 40 Μg/kg i.v. the formation of occlusive thrombi was prevented up to 3 h after lysis. TFPI at the doses used caused modest anticoagulant effects in global clotting assays; activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) were only slightly prolonged. A clear and dose-dependent prolongation of clotting times was only seen in the Heptest® assay.The results show that the physiologic coagulation inhibitor TFPI acts as a strong antithrombotic agent in an experimental model of venous thrombus formation and thrombotic reocclusion after lysis in rabbits.
An Evaluation and Improvement Program for Inpatient Anticoagulant Control
Authors: Phillips W S , Smith J , Greaves M , Preston F E , Channer K S 
Published: July 2018

SummaryTo improve the management and therapeutic control of inpatients on anticoagulant drugs, combined prescription and monitoring charts have been developed for both heparin and warfarin which incorporate clinical guidelines. These have been introduced throughout a 700-bedded acute teaching hospital via a structured program of change management.We have demonstrated improvements in the quality of anticoagulant control (assessed with a custom-written computer program), adherence to clinical guidelines and quality of monitoring and prescribing of anticoagulants in inpatients.The percentage time spent under-anticoagulated with heparin (activated partial thromboplastin time ratio <1.5) fell from 32.7% to 18.5% (p<0.0001), whereas there was no change in percentage time over-anticoagulated (5.1% vs. 5.8%; p = ns). The percentage time spent under-anticoagulated with warfarin was unaltered (26.3% vs. 29.8%; p = ns) but the percentage time spent over-anticoagulated (International Normalised Ratio >4.5) was halved from 5.4% to 2.7% (p<0.001).We conclude that the introduction of the charts led to significant improvements in anticoagulant control.
Plasma Macrophage Colony-Stimulating Factor and P-Selectin Levels in Malaria-Associated Thrombocytopenia
Authors: Lee S H , Looareesuwan S , Chan J , Wilairatana P , Vanijanonta S , Chong S M , Chong B H 
Published: July 2018

SummaryThrombocytopenia is a common finding in malaria. In clinical trials, recombinant macrophage colony-stimulating factor (M-CSF) causes a reversible, dose-dependent thrombocytopenia, and high M-CSF has been reported in autoimmune thrombocytopenias. P-selectin, which is secreted into the plasma following platelet/endothelial activation or damage, is elevated in certain consumptive thrombocytopenic disorders. The relationships between thrombocytopenia, M-CSF and P-selectin were analysed in 63 patients with severe (n = 13) or uncomplicated (n = 26) P. falciparum (PF) or P. vivax (PV) malaria (n = 24). On admission, 69% of PF patients and 75% of PV patients were thrombocytopenic (platelets < 150 X 109/1). M-CSF was elevated in PF (3021 ± 1844 pg/ml) and PV (2602 ± 1668 pg/ml) patients, compared to controls (589 ± 200 pg/ml). The platelet count was inversely correlated with M-CSF in PF (r = -0.681), and in PV malaria (r = -0.548). Elevated P-selectin was found in severe PF malaria, but not in PV malaria. Severe PF malaria was associated with marked thrombocytopenia, very high M-CSF, elevated P-selectin and compelling evidence of disseminated intravascular coagulopathy (DIC). Platelet counts, M-CSF and P-selectin returned to control values in 7-14 days. These data suggest that elevated M-CSF in malaria, by enhancing macrophage activity, may result in increased macrophage-mediated platelet destruction. Further, platelet/endothelial activation or damage, as measured by P-selectin, or DIC could intensify thrombocytopenia in severe PF malaria, but does not appear to contribute to thrombocytopenia in uncomplicated PF or PV malaria.