bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring of Heparin and Low Molecular Weight Heparin with Capillary and Venous Whole Blood
Authors: Harenberg J , Giese Ch , Dempfle C E , Stehle G , Heene D L 
Published: June 2018

SummaryA method for determination of antifactor Xa-like activity in capillary whole blood obtained from the fingertip is described, which employs the Heptest coagulation assay. Values obtained with capillary whole blood are compared to values of corresponding plasma and venous whole blood samples. Normal values in plasma, venous whole blood, and capillary blood from the fingertip were 17.1 ± 2.1, 10.0 ± 1.3 and 10.4 ± 1.3 sec, respectively. The intraindividual coefficients of variations range from 0.4 to 1.8% in all assays. The day to day coefficient of variation of normal values ranged between 0.8 and 2.0% for all assays. The within assay coefficients of variation ranged from 3.0 to 7.7% for whole blood samples and from 1.5 to 2.2% for plasma samples after addition of no, 0.2 or 1.0 units of normal or LMW heparin to the samples. After administration of heparin or LMW heparin in healthy persons the coagulation values of the different coagulation assay systems displayed coefficients of correlation betweell r = 0.87 and r = 0.95. Correlation coefficients between the coagulation tests and the S 2222 chromogenic substrate method ranged from r = 0.77 to r = 0.92. In patients, who received LMW heparin for prophylaxis of thromboembolism the coagulation assay correlated between r = 0.78 and 0.92. The coagulation assays and the S 2222 method displayed coefficients of correlation between r = 0.74 and r = 0.83. The data indicate that Heptest sensitively measures antifactor Xa-like activity in capillary whole blood as well as venous whole blood samples containing low quantities of heparin or LMW heparin.
Growth and Stability of Thrombi in Flowing Citrated Blood: Assessment of Platelet-Surface Interactions with Computer-Assisted Morphometry
Authors: Sakariassen Kjell S , Kuhn Herbert , Muggli Reto , Baumgartner Hans R 
Published: June 2018

SummaryThe differential quantitation of platelet deposition in perfusion
studies is a major problem. We report on methods to prepare semithin sections of platelet deposits on collagen coated on glass and plastic cover slips, to study growth and stability of thrombi in three dimensions, and the development of a computer-assisted differential quantitation of platelet-collagen interactions. The interactions were quantified as percentage of the surface covered with platelets (platelet adhesion), thrombus height, thrombus density and thrombus area per unit sectional length, respectively.Cover slips coated with fibrillar equine collagen in parallelplate
perfusion chambers were exposed to flowing citrated blood at shear rates ranging from 200 to 2,600 s−1. Thrombi, partially
enmeshed in the collagen meshwork, prevailed on the surface at all shear rates. Maximal platelet adhesion and thrombus density were seen at >5 μg/cm2 collagen, while thrombus area and height were maximal at >10 μg/cm2. The volume of the thrombi appeared correlated to the number of deposited platelets (r = 0.92). En face preparations showed deposits of platelet islands
which grew in diameter with time, particularly in the direction of the blood flow, becoming progressively confluent. Sections cut parallel to the direction of the blood stream indicated that this growth pattern was at least partially caused by thrombi bent in the direction of the blood flow. This view is consistent with data from corresponding sections cut perpendicular to the direction of the blood flow showing that the initial thrombus growth at 2 min is isotropic, while anisotropic growth, characterized with decreased growth in height, is observed at 5 and 10 min.Our three-dimensional analysis suggests that the growth occurs mainly in height, and that blood shear forces may bend the thrombi toward the surface resulting in platelet thrombi preferentially elongated in the direction of the blood flow.
Modulation of Heparin Cofactor II Function by S Protein (Vitronectin) and Formation of a Ternary S Protein-Thrombin-Heparin Cofactor II Complex
Authors: Preissner Klaus T , Sié Pierre 
Published: June 2018

SummaryThe complement inhibitor S protein, which is identical to the adhesive protein vitronectin, functions as heparin-neutralizing factor by protecting thrombin as well as factor Xa against fast inactivation by antithrombin III. The interference of S protein with glycosaminoglycan-catalyzed inhibition of thrombin by heparin cofactor II was investigated in these studies. S protein significantly counteracted the anticoagulant activity of heparin and pentosan polysulfate but not of dermatan sulfate. In the presence of 0.3 μg/ml heparin, 0.5 μg/ml pentosan polysulfate, or 2 μg/ml dermatan sulfate, S protein induced a concentrationdependent
reduction of the inhibition rate of thrombin by heparin cofactor II. This resulted in a decrease of the apparent pseudo first-order rate constants by about 17-fold (heparin), or about 7-fold (pentosan polysulfate), whereas no neutralization of dermatan
sulfate was demonstrable at a physiological ratio of S protein to heparin cofactor II. Exposure of the glycosaminoglycan-binding region of S protein by reduction and carboxymethylation of the protein increased the neutralizing activity of S protein towards heparin and pentosan polysulfate. The results of these functional experiments correlated well with the demonstration of direct binding of S protein to both polysaccharides but not to
dermatan sulfate. While reduced/carboxymethylated S protein remained also ineffective in neutralizing other dermatan sulfate compounds with varying degree of sulfation, a synthetic highly basic tridecapeptide, representing a portion of the glycosaminoglycan-binding domain of S protein, counteracted their anticoagulant activity. Independent on the polysaccharide used, S protein was found incorporated within a ternary complex with thrombin and heparin cofactor II during the inhibition reaction as judged by crossed immunoelectrophoresis, ultracentrifugation as well as ELISA analysis, emphazising the function of S protein as scavenger protein for enzyme-inhibitor complexes of the coagulation system. These findings demonstrate the role of S protein as effective neutralising plasma protein of the anticoagulant activity of various glycosaminoglycans also with respect to heparin cofactor II. Although the glycosaminoglycan-binding domain of S protein readily neutralized different dermatan sulfate compounds, physiological modulation of heparin cofactor-II-dependent
inhibition of thrombin by native S protein appears to be restricted to the vascular compartments, where other glycosaminoglycans than dermatan sulfate appear to be operative.
Modified Crossed Immunoelectrophoresis to Study with Whole Plasma the Reversible Complex Formation of Histidine-Rich Glycoprotein with Plasminogen
Authors: Kluft C , Los P 
Published: June 2018

SummaryTo study the reversible complex formation between the plasma protein histidine-rich glycoprotein (HRG) and plasminogen, crossed immunoelectrophoresis of HRG was modified. In the modification, purified plasminogen was introduced into the gel of the first dimension electrophoresis.Two molecular forms of plasminogen, Glu- and Lys-plasmino-gen, induced a dose-dependent reduction of the electrophoretic mobility of HRG, with a half maximal retardation for both plasminogens at 0.50–0.55 μM of added plasminogen to the agarose gel. HRG in plasma behaved as a uniform fraction with respect to plasminogen binding. In contrast, with the same modified technique another plasma protein, β2-antiplasmin, separated into a retarded plasminogen-binding form and a nonretarded non-plasminogen-binding form.The method can be used to assess several aspects of reversible complex formation between plasma proteins, as demonstrated for plasminogen binding of HRG and α2-antiplasmin in whole plasma.
A Monoclonal Antibody-Based Qunatitative Enzyme Immunoassay for the Determination of Plasma Fibrinogen Concentartions
Authors: Hoegee-de Nobel E , Voskuilen M , Briët E , Brommer E J P , Nieuwenhuizen W 
Published: June 2018

SummaryThe most commonly used fibrinogen assays in the clinic are clotting rate assays, e.g. the Clauss method. Such functional assays may be disturbed by e.g. heparin, anticoagulant fibrinogen degradation products (FgDP) and in the case of a dysfi-brinogenemia. Immunological methods would not suffer from these interferences. However, immunological assays for fibrinogen, which do not measure FgDPs, do not exist.To set up such an enzyme immunoassay (EIA) we developed two monoclonal antibodies. The first monoclonal antibody (G8) has its epitope in the carboxyl-terminal 150 amino acid stretches of the fibrinogen Aa-chains. G8 is used to coat the wells of microtitration plates, and is the capture antibody in this EIA. The second antibody (Y18) has been described by us previously (Blood 1985; 66: 503). It is directed against fibrinopeptide A, covalently bound to the ±-chains i.e. against the amino-terminal stretches of the A±-chains. Y18 is conjugated with horse-radish peroxidase, and used as tagging antibody.The EIA does not react with, and is not interfered by FgDP such as purified fragments X and Y, up to a concentration of 800 μg/ml. An FgDP mixture such as generated by Streptokinase treatment of plasma does not respond. Fibrin degradation products (whole blood lysate) up to 800 μg/ml do not interfere nor do heparin, EDTA or oxalate. The time-to-result of the EIA is only 45 minutes. Some patient plasmas yielded dose-response curves which are not parallel with the calibration curve of the EIA. An explanation for this phenomenon could not be given. Our fibrinogen EIA may be especially suitable to monitor patients with conditions which favour proteolytic damage to fibrinogen such as thrombolytic therapies.
Characterization of the Binding of Bovine Thrombin to Isolated Rat Hepatocytes
Authors: Weyer Britta , Petersen Torben E , Sonne Ole 
Published: June 2018

SummaryIsolated rat hepatocytes possess per cell 4,500 high-affinity binding sites for thrombin with a Kd of 30-40 pM, and 2.8 × 105 low-affinity sites with a Kd of 30 nM. These binding sites are highly specific for thrombin. Half-maximal binding of 125I-labelled thrombin is achieved after 3 min at 37¸ C and 7 min at 4¸ C. The reversibly bound fraction of the ligand dissociates according to a biexponential time course with the rate constants 1—2 × 10−2 s−1 and 3—4 × 10−4 s−1. Part of the tracer remains cell-associated even after prolonged incubation, but all cell-associated radioactivity migrates as intact thrombin upon sodium dodecyl sulphate polyacrylamide gel electrophoresis. The bound thrombin is minimally endocytosed as judged by the resistance to pH 3-treatment. Cell-associated radioactivity dissociated from the cells binds just aswell in a receptor assay as tracer incubated in a conditioned medium under the same conditions, indicating the absence of a quantitatively important receptor-mediated degradation ofthe ligand.
Fibrin Metabolism in Patients with Acute Myocardial Infarction During and After Treatment with Tissue-Type Plasminogen Activator
Authors: Ring Michael E , Butman Samuel M , Bruck Denise C , Feinberg William M , Corrigan James J 
Published: June 2018

SummaryIn order to define some of the determinants of successful thrombolysis and reocclusion during fibrinolytic therapy for acute myocardial infarction (AMI), specific molecular markers of fibrin metabolism were serially measured in 15 patients with AMI treated with tissue-type plasminogen activator (t-PA). Fibrin formation was assessed by measurement of fibrinopeptide A (FpA) and fibrinolysis by assay of B-P peptides 1—42 and 15—42 and crosslinked fibrin degradation products (XDP). At baseline, FpA levels were high while markers of fibrinolysis were near normal. Following a 90-minute infusion of t-PA (0.5—1.1 mg kg−1 hr−1), all markers of fibrinolysis increased. Levels of FpA remained elevated despite heparin at the initiation of cardiac catheterization. None of these markers discriminated between patients with successful reperfusion from those without. At 4 hours, B-β 15—42 peptide and XDP levels remained elevated suggesting persistence of fibrinolysis beyond the short circulatory half-life of t-PA. FpA levels at 4 hours were lower in patients who underwent acute coronary angioplasty compared to those who received additional low dose t-PA (12.3 ± 4.5 vs. 30.4 ± 5.5 ng/ ml, p <0.05). By 48 hours, markers of fibrinolysis had returned toward normal except in 2 patients with persistently elevated B-P 15—42 peptide levels who suffered reocclusion on days 5 and 6 (75 and 44 vs. 29 ± 3 nM, p <0.005). In conclusion, molecular markers of fibrin metabolism during fibrinolytic therapy may provide clinically relevant data.
Commercial Immunodepleted Deficient Plasmas Contain Cleaved High Molecular Weight Kininogen (HK)
Authors: Mannhalter C , Lang H 
Published: June 2018

SummaryComparative analysis of high molecular weight kininogen (HK) in various commercial congenital and immunodepleted deficiency plasmas was performed by immunoblotting of HK. It was found, that some artificially depleted deficiency plasmas contained proteolytically cleaved, kinin-free kininogen. In contrast, in all congenitally deficient plasmas, HK was present in the intact, single chain form. Thus, cleavage of kininogen could have been triggered by or during the immunodepletion procedure. It was seen, that the degree of proteolytic cleavage and degradation of HK in depleted plasmas differed among various manufacturers. E.g. depleted products of one company contained only trace amounts of cleaved HK, in contrast to products of another one, in which HK was completely degraded. The immunoblot analysis of HK reflects the occurrence of proteolytic events during the production of artificially deficient plasmas and can therefore serve as a quality control method.
Clot Lysis Mediated by Cultured Human Microvascular Endothelial Cells
Authors: Speiser Wolfgang , Anders Elisabeth , Binder Bernd R , Müller-Berghaus Gert 
Published: June 2018

SummaryThe lysis of fibrin clots on the surface of cultured human omental tissue microvascular endothelial cells (HOTMEC) and cultured human umbilical vein endothelial cells (HUVEC) was studied. Fibrin clots were made by mixing fibrinogen, plasminogen and thrombin on the surface of both cell types. Clot lysis was seen only on the surface of HOTMEC, which were found to synthesize about 100-fold more tissue plasminogen activator (tPA) antigen than HUVEC. Clot lysis of HOTMEC could be blocked by anti-tPA IgG but was not affected by the incorporation of exogenous plasminogen activator (PAI) into the clot in concentrations (75 arbitrary units) exceeding the tPA activity (21 ± 2.5 IU) of the cells. Thus, it is likely that tPA secreted by HOTMEC is protected from inhibition by PAI in the presence of fibrin and endothelial cells. The stimulation of EC to release an excess of tPA over PAI, in contrast to the secretion of an excess of PAI over tPA found in unstimulated cells in the absence of fibrin, is obviously no prerequisite for the initiation of fibrinolysis on the surface of HOTMEC. As thrombin was used for clot formation, its influence on tPA and PAI synthesis of both cell types was investigated. In contrast to HOTMEC, which were not affected by Α-thrombin, HUVEC revealed a dose-dependent increase in tPA and PAI synthesis upon incubation with the enzyme. This increase in tPA production by HUVEC was not sufficient to lyse the clots within 48 hours. Furthermore, HUVEC. behaved differently towards thrombin as these cells in contrast to HOTMEC revealed the typical shape change reaction upon incubation with the enzyme
Tissue-Type Plasminogen Activator in Patients with Intracranial Meningiomas
Authors: Tsuda Hiroko , Oka Kazunari , Noutsuka Youko , Sueishi Katsuo 
Published: June 2018

SummaryThree of 13 patients with intracranial meningiomas showed the pre- and postoperative elevation of tissue-type plasminogen activator (t-PA) related fibrinolytic activity in euglobulin fractions (EFA). During operation, two of these three patients showed a significant elevation of the level of fibrin(ogen) degradation products and oozing in the operating field. However, oozing was not observed in the third patient who had been given tranexamic acid preoperatively. Fibrin autography revealed that a broad lytic band of mol wt 50–60 kDa, probably free t-PA, appeared in the plasma obtained from two of the three patients after operation when EFA elevated significantly. In all patients studied, the t-PA antigen levels were normal preoperatively but increased both during and after operation, and correlated mainly with the intensities of a lytic band of mol wt 110 kDa, probably t-PA complexed with its major inhibitor (PAI–1). These results suggest that the excessive fibrinolysis can induce the local hemorrhagic diathesis during operation and may be related to t-PA function in plasma
Antithrombin III Molecular Variants with Defective Binding to Heparin or to Serine Proteases: Evidence of Two Different Abnormal Patterns Identified by Crossed Immunoelectrofocusing
Authors: Leone G , Stefano V De , Ferrelli R , Teofili L , Tengborn L , Vahtera E , Bizzi B 
Published: June 2018

SummaryMolecular heterogeneity of antithrombin III (AT III) was investigated by a technique of crossed immunoelectrofocusing (CIEF) in plasma samples of patients from 16 families with AT III congenital defect, including 8 AT III molecular variants. The AT III CIEF pattern was normal in all the patients with AT III quantitative deficiency, showing a balanced decrease of all the peaks. Out of the 8 AT III variants investigated, 6 had an abnormal pattern: the three variants with defective binding to heparin (AT III Roma, AT III Barcelona, AT III Malmö) shared a similar abnormal pattern; three variants with defective binding to serine proteases (AT III Pescara, AT III Milano, AT III Tampere) had a common abnormal pattern clearly different from the first one, whereas the other two variants deficient in the inactivation of the serine proteases (AT III Chicago, AT III Milano 2) showed a normal pattern. The first type of pathological pattern (type Roma) was characterized by the presence of an abnormal peak overlapping the normal isoforms present at pH 4.8-4.6 and by an additional peak at pH 4.5. The second type of pattern (type Pescara) showed an additional peak at pH 4.5 and an abnormal quantitative distribution of the isoantithrombins all throughout the pH range (5.2-4.6). In order to separate the abnormal AT III fraction from the normal one, plasma of a patient with Roma defect and serum of a patient with Pescara defect were passed throughout an heparin-ultrogel column. The CIEF of the different AT III Roma and AT III Pescara fractions obtained by affinity chromatography confirmed that the abnormalities found in the corresponding patterns of the native samples were related to the pathological isoantithrombins only. It was concluded that the CIEF can be an useful tool to characterize abnormal antithrombins and can reveal close affinities among AT III molecular variants belonging to different subgroups according to the conventional tests.
Further Evidence of von Willebrand Factor Involvement in Thrombotic Thrombocytopenia Purpura
Authors: Chediak J , Eldridge J , Bergmann F , Sobel D , Baron J , Maxey B , Telfer M C 
Published: June 2018

SummaryFourteen patients diagnosed as having thrombotic thrombocytopenia purpura (TTP) were studied. Those who survived have been followed during a 1 to 7 year period. The clinical diagnosis was based on changing neurological findings, thrombocytopenia and evidence of microangiopathic hemolytic anemia. Laboratory tests included the determination of von Willebrand factor antigen (VWF:Ag), ristocetin cofactor (RiCof) and the electrophoretic mobility of von Willebrand factor (CIE VWF:Ag). The ratio of RiCof to VWF:Ag was then calculated. Control individuals included healthy subjects and patients with thrombocytopenia of several etiologies. Statistical differences between the values of RiCof, the ratio of RiCof : VWF: Ag and the CIE of VWF: Ag were found for samples comparing active disease and remission phase. The recovery from thrombocytopenia paralleled the correction of abnormal parameters. Similarly, significant differences were found when above parameters were compared between thrombocytopenia of TTP with other thrombocytopenic states. We suggest that these abnormal tests could be useful in distinguishing TTP from other disorders, and may have prognostic significance in patients already diagnosed as having TTP.
A Simple Nomogram for the Derivation of International Normalised Ratios for the Standardisation of Prothrombin Times
Authors: Poller L 
Published: June 2018

SummaryThe WHO international scale of reporting prothrombin time results is based on the calibration of local and commercial thromboplastin reagents used in the test against an international reference preparation to derive an International Sensitivity Index (ISI) for each batch of local reagent. This quantifies an individual reagent’s responsiveness to the coumarin induced defect.Once the ISI has been assigned, the derivation of International Normalised Ratios (INR) for reporting results depends on the use of a scientific calculator by which the local ratio is raised to the power of the ISI of the local reagent or use of an alternative formula and logarithms.A system for interpretation of INR, without the need for calculations, is presented for the known range of thromboplastins between 1.0 and 3.0 ISI in nomogram form. This chart may facilitate the general application of the INR system.
Platelet Function and Plasma Fibrinogen and their Relations to Gender, Smoking Habits, Obesity and Beta-Blocker Treatment in Young Survivors of Myocardial Infarction
Authors: Berglund Ulf , Wallentin Lars , Schenck Henning von 
Published: June 2018

SummarySeventy-three (58 men and 15 women) survivors of myocardial infarction below 45 years of age and 73 healthy matched controls were investigated regarding in vitro platelet aggregability to ADP and collagen, platelet sensitivity to prostacyclin and plasma levels of beta-thromboglobulin, platelet factor 4 and fibrinogen. The patients, studied 3-6 months after the acute event, had a reduced platelet sensitivity to prostacyclin. They did not differ from the controls regarding the other platelet function tests. Females had higher platelet reactivity than men. Smoking, obesity or beta- blocker treatment did not influence platelet function. The patients had higher fibrinogen levels than the controls. Gender did not influence, while smoking and obesity increased plasma fibrinogen. Patients on beta-blockade had lower fibrinogen levels than patients without this therapy. The high fibrinogen level and the low platelet sensitivity to prostacyclin might indicate an increased thrombotic liability in young myocardial infarction patients.