bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation, Consistency and Degradation of Artificial Thrombi in Severe Renal Failure
Authors: Dintenfass L , Stewart J. H 
Published: June 2018

SummaryA novel study of dynamic blood coagulation in uraemic patients was based on the application of the variable-frequency thromboviscometer, VFTV, an advanced form of the thrombelastograph. Clotting times, rates of formation, consistencies, and rates of degradation of artificial thrombi cast at 60 and 180 cycles/min (equal to mean shear rates of 26.8 and 80 sec–1) were investigated in 35 patients and in normal controls.The study shows that there exists a profound difference in VFTV parameters between normals and patients with severe renal failure. The most significant are the rate of degradation of thrombi formed at 60 cycles/min (p < 0.001), the consistency of thrombi formed at 180 cycles/min (p < 0.005), and the total thrombus formation time at 180 cycles/min (p < 0.001). Thrombi formed at 60 cycles/min adhered to brass rather than Teflon in many patients with renal failure, in contrast to the findings in normals and in all types of patients previously tested.A division of patients into clinical subgroups (acute renal failure, non-oliguric or oliguric chronic renal failure, and long-term dialysis) shows that all these groups are quite homogeneous from the dynamic coagulation viewpoint, although the thrombus degradation rate (when coagulation proceeds at 60 cycles/min) differs significantly (p = 0.025) between the long-term dialysis group and the non-oliguric chronic renal failure group. These same groups also show a difference in their platelet count. The VFTV abnormalities of uraemia could not be correlated with either the severity of the measurable biochemical derangement or the qualitative platelet defect.An unexpected, but statistically significant, pattern appeared when patients were divided according to their ABO blood groups. The rate of degradation of the thrombus formed at 60 cycles/min differed significantly between 0 and A and between B and A blood groups (p < 0.01). The rate of formation of the white thrombus at 180 cycles/ min differed significantly (p < 0.05) between 0 and A blood groups. Simultaneously, the platelet count differed between blood groups 0 and B (p = 0.05) and between 0 and A (p < 0.005).Effect of blood groups on the VFTV parameters is evident even in the normal controls; here, the rate of degradation of the thrombus formed at 60 cycles/min showed significant difference between blood groups A and B (p < 0.005) and a smaller difference between 0 and B(0.05 < p <0.1).We consider that the demonstration that the consistency of white thrombi is twice as high in uraemic patients than in normals, and that the rate of degradation of the red-white thrombi is nearly ten-fold greater is of fundamental importance. Both these phenomena might be associated with the known platelet defects of uraemia, or with a possible further abnormalities of fibrinogen, caused by the presence of one or more of the chemical substances which accumulate in the uraemic state.
Chromatographic Isolation of the LDH-Isoenzymes of Human Blood Platelets and an Investigation of Their Enzyme Kinetics
Authors: Schneider W , Schumacher K , Thiede B , Gross R 
Published: June 2018

SummaryThe LDH-isoenzymes of human blood platelets show a distinct predominance of the isoenzymes 2 and 3 upon chromatography on DEAE-cellulose. Small amounts of LDH-1 are also present, while only traces of LDH-4 and -5 can be detected.Enzyme kinetic investigations of the principal isoenzymes LDH-1, -2 and -3 clearly show that the differences in inhibition constants with pyruvate as substrate which are demonstrable at 25° largely disappear at 37°. On the other hand, the differences among the isoenzymes in their affinity for pyruvate and lactate as substrate as well as in with respect to the optimal substrate concentrations of pyruvate are more marked at 37° than at 25°. Also, the type of inhibition found with lactate as substrate is increasingly the expression of a higher order reaction in going from LDH-1 to LDH-3. A dependence of the LDH distribution pattern upon the metabolism of the cell is discussed. A comparison of our results with thrombocytes with those of other workers with erythrocytes and leucocytes makes it unlikely that the LDH pattern is directly dependent upon the existence of an oxidative metabolism. Rather, the redox potential of the cell could be of importance for the nature of the pattern of isoenzymes and for their differing kinetic properties.
Investigation of the Apparent Thrombogenicity of Thrombin
Authors: Yin E. T , Wessler S 
Published: June 2018

SummaryThis investigation demonstrates that most of the thrombogenic effect of small amounts of commercial thrombin is not dependent upon the calculated units of infused thrombin but rather upon its contamination with activated factor X. These data also reflect the need to re-evaluate the biologic effects attributed to thrombin itself in various studies in which thrombin preparations contaminated with activated factor X have been employed.
Treatment of Factor XIII Deficiency with Cryoprecipitate
Authors: Amris C. J , Hilden M 
Published: June 2018

SummaryIn in vitro and in vivo investigations of two patients with congenital factor XIII-deficiency it was demonstrated that cryoprecipitate contains a high factor XIII-activity. Cryoprecipitate in small amounts, given as intravenous injections every 3 or 4 weeks seems to be useful as a prophylactic treatment of patients with severe haemorrhagic due to factor XHI-deficiency.
A Double Blind Study of the Effect of Tranexamic Acid in Essential Menorrhagia
Authors: Vermylen J , Verhaegen-Declercq M. L , Verstraete M , Fierens F 
Published: June 2018

SummaryOral administration of tranexamic acid, in a dosage of 3 g daily from the first day of menstruation onwards, significantly decreases menstrual haemoglobin loss in women with so-called essential menorrhagia.The frequency of side-effects reported did not differ between “active” and “placebo” periods.
Simplification of the Concept of Coagulation by Revival of the Inhibitor Theory
Authors: Mann F. D 
Published: June 2018

SummaryIt is proposed that there are only two factors essential for the conversion of prothrombin to thrombin : vitamin K dependent factor (KDF) and antihemophilic factor (AHF). In order to form the reaction complex for the conversion of prothrombin to thrombin, a KDF – calcium molecule and an AHF molecule, each bearing an active site, become bound on the surface of a lipid thromboplastin particle and the inhibitor initially associated with the KDF and AHF shifts to KDF and AHF molecules which are directly adjacent on the thromboplastic surface and which have inhibitor receptor sites free. In different abnormalities of coagulation KDF and AHF exist in multiple molecular forms varying with respect to presence or absence and steric location of active sites, inhibitor receptor sites and inhibitor. Thus in different abnormahties of coagulation KDF or AHF may be inactive for different reasons and mixed populations of abnormal KDF and AHF can supplement each other to form the reaction complex which requires only two molecules. This is a simpler concept than one requiring a separate essential factor and a separate reaction step to explain each different abnormality. Evidence is presented for this point of view.
Recovery of Fibrinogen in Fibrinolytic Dogs
Authors: Young M. C , Kolmen S. N 
Published: June 2018

SummaryExperiments were performed to determine the relative roles of hypofibrinogenemia and split products in fibrinogen replenishment. After fibrinogen depletion, recovery was enhanced when split products were present. Additionally, the presence of split products alone effected a significant increase in fibrinogen concentration without prior depletion; hypofibrinogenemia alone was not as consistent in stimulating replenishment.Perhaps hypofibrinogenemia creates a concentration gradient to favor release of previously stored fibrinogen and reduce storage of newly synthesized fibrinogen. Split products, on the other hand, may increase circulating fibrinogen by competition for available storage sites, facilitation of release from synthesis, or reutilization in synthesis of new fibrinogen.
Isolation and Purification of Highly Enriched Tissue Plasminogen Activator from Pig Heart
Authors: Rickli E. E , Zaugg H 
Published: June 2018

SummaryA method for the isolation of highly purified plasminogen activator from porcine heart was developed. Fresh, frozen tissue was homogenized and extracted with 5 M urea. Upon dilution of the urea extract with 0.02 M acetate buffer, 0.05 M NaCl, pH 5.0, a large amount of inert protein precipitated. It was removed by low-speed centrifugation, leaving an active, cell-free supernatant. CM Sephadex C-50, added to this solution, adsorbed the active material quantitatively. Washing of the ion exchanger with 0.02 M acetate buffer, 0.26 M NaCl, pH 5.0, removed additional impurities. The activator was eluted by increasing the NaCl concentration of the acetate buffer to 0.6 M. Further purification was achieved by a fractionated precipitation with ammonium sulfate at 30% saturation, pH 7.5. The precipitated activator was solubilized in 0.02 M acetate buffer, 0.6 M NaCl, pH 5.0. The resulting active solution was subjected to gel filtration in a column of Sephadex G-200, in the same buffer medium. In this step, a substantial amount of inert, higher molecular weight material was eliminated. The active fractions were pooled and diluted with 0.02 M acetate buffer, pH 5.5, to reduce the NaCl concentration to 0.15 M. This solution was passed through a column of SE Sephadex C-50, in 0.02 M acetate buffer, 0.15 M NaCl, pH 5.5, which adsorbed the active material. The activator was eluted from the column with a salt gradient (0.15 M to 0.4 M NaCl) in 0.02M acetate buffer,pH 5.5. From 3kg of heart tissue, about 1.5 mg of highly purified activator were obtained, in a yield of 35% (with respect to the urea extract). The preparation had a specific activity of 38,900 CTA units per mg protein, determined with a fluorometric assay method, using fluorescence labeled fibrin substrate and a calibration curve with a urokinase standard for conversion of the activity to CTA units. The product was highly stable, and it was devoid of unspecific protease activity. Disc electrophoresis in Polyacrylamide gel at pH 9.5 showed a single sharp band.
Blutgerinnung und Fibrinolyse im Nabelschnurblut
Authors: Gmür J. P , Straub P. W 
Published: June 2018

Zusammenfassung1. Resultate von Gerinnungs- und Fibrinolyseuntersuchungen im Nabelschnurblut sind nur zuverlässig, wenn das Blut durch Punktion der Nabelschnurgefäße gewonnen wurde. Aus der durchtrennten Nabelschnur entnommene Blutproben zeigen oft eine Spontangerinnung, eine starke Streuung der Fibrinogen- und Thrombinzeitbestim-mungen, einen höheren Faktor V und eine nicht geklärte Verminderung der fibrino-lytischen Aktivität.2. Für die Beurteilung der Gerhmungsverhältnisse und der fibrinolytischen Aktivität in vivo aus Nabelschnurvenenblut erwies sich der Zusatz eines Fibrinolysehemm-körpers bei der Blutentnahme als unerläßlich.
Second Phase Platelet Aggregation Induced by Adenosine Diphosphate in Patients with Cerebral Vascular Disease and in Control Subjects
Authors: Danta G 
Published: June 2018

SummaryAdenosine diphosphate-induced second phase platelet aggregation was studied in 70 patients with established cerebral vascular disease, 27 patients with chronic cerebral vascular disease taking dipyridamole, and 53 control subjects. The appearances of aggregation graphs relating changes in optical density in platelet-rich plasma to time after addition of adenosine diphosphate are described. An intermediate rate change in optical density was observed between first and second phase aggregation.Induction of second phase aggregation depends on the concentration of adenosine diphosphate and the platelet count of the plasma. Individual rseponses vary greatly, and there is appreciable variability in repeated estimations, but in the same plasma responses to adenosine diphosphate are accurately reproducible.In both patients and controls the mean logarithm of the adenosine diphosphate concentration that just induces second phase aggregation is inversely proportional to the mean platelet count of platelet-rich plasma. At all platelet concentrations studied, the smallest concentration of adenosine diphosphate that brought about second phase aggregation was significantly less in the patients than in controls. There was no significant correlation between the means of the two variables in patients taking dipyridamole. The findings in this group of patients accord with the assumption that dipyridamole favourably affects the abnormal reaction of platelets to adenosine diphosphate in some of the patients with cerebral vascular disease.
The Preparation and Evaluation of a Standardized Fibrin Plate for the Assessment of Fibrinolytic Activity
Authors: Bishop R , Ekert H , Gilchrist G , Shanbrom E , Fekete L 
Published: June 2018

SummaryA new fibrin plate technic for evaluating components of the fibrinolytic system has been developed. It provides quick, accurate, and easily interpreted results for the fibrinolytic profile. The standardized human plasminogen-free fibrin plates can be produced in bulk and stored for prolonged periods of time. A test specimen placed in a well punched in the buffered agarose gel diffuses into the agar and lyses the fibrin clot, forming a clear reaction zone. The zone diameter is directly proportional to the log of the percent concentration of available fibrinolytic enzyme in the specimen. The plates may be used to quantitate total plasminogen, and estimate available plasmin and active plasmin. A good correlation between results obtained using these fibrin plates and caseinolytic methods was found. Performance and interpretation of tests of fibrinolysis done on these new fibrin plates indicate that it may be the most sensitive technic available for clinical laboratory work.
Platelets in Rheumatoid Arthritis
Authors: Pazdur J , Kopeć Maria 
Published: June 2018

SummaryPlatelet counts and adhesiveness in vivo were examined in 140 patients with rheumatoid arthritis and in 30 healthy subjects. Increased platelet counts were found in 50% of cases and impaired adhesiveness in vivo in 40%. Thrombocyte counts showed high positive correlation with leukocytosis but none with adhesiveness in vivo and degree of anemia. Ivy bleeding time was prolonged in 15 among 30 examined r.a. cases. Adhesion of normal platelets to purified collagen prepared from tendons of r.a. patients was found to be unimpaired. Aggregation of platelets with connective tissue extracts was delayed in r.a. PRP as compared with normal PRP. Extracts of r.a. synovia was less effective as aggregating agent than extracts of control synovia. It was found that a single dose of aspirin (2 g) does not influence platelet adhesiveness in vivo in healthy persons. On the basis of the presented results and literature data it is suggested that overproduction of platelets is a probable cause of thrombocytosis in r. a. while impairment of in vivo adhesiveness may be due to intrinsic defect of platelet and/or to presence of some inhibitory substances in blood and tissues.
Two Types of Prothrombin in Vitamin K Deficiency
Authors: Hemker H. C , Muller Annemarie D. , Loeliger E. A 
Published: June 2018

SummaryIn vitamin K deficiency (either absolute or induced by oral anticoagulants) two types of prothrombin occur. One is not distinguishable from normal prothrombin. It generates thrombin quickly in a medium in which the factors V, VII and X, thromboplastin and Ca++ are present in sufficient amounts. The other is converted into thrombin much more slowly under the same conditions. In the onestage prothrombin assay only the first form is measured, in a two-stage prothrombin assay both forms are estimated. This accounts for the well-known discrepancy between these two tests in vitamin K deficiency. The abnormal prothrombin can be considered one of the Proteins Induced by Vitamin K Absence. The occurrence of this kind of proteins fits in the concept of the action of vitamin K as a co-factor in a system that converts polypeptide-precursors into coagulation factors.
A Study of Antihaemophilic Globulin (Factor VIII) Consumption
Authors: Sen N. N , Denson K. W. E , Biggs Rosemary 
Published: June 2018

SummaryA study has been made of the rate of disappearance of factor VIII during the clotting of n Dr mal plasma samples and of samples deficient in factors V, VII, IX, X, XI and XII. The rate of disappearance (or consumption) of factor VIII was the same in the normal and factor VII deficient samples. Delayed disappearance of factor VIII was observed in samples deficient in factors V, IX, X, XI and XII. The significance of the findings to the theory of blood coagulation is discussed.
On the Natural Blood Coagulation Inhibitor System Investigations of Inhibitor Factors Based on Antithrombin Deficient Blood
Authors: Egeberg O 
Published: June 2018

SummaryNatural coagulation inhibitor factors were studied in sera, or in fractions of sera, from patients with congenital partial deficiency of antithrombin and from normal persons. In the patients’ sera the progressive antithrombin (antithrombin III) and heparin cofactor (antithrombin II) had both been measured around 50 per cent of normal level.No decreased activity could be demonstrated in the patients’ sera as to antiprothrombinase, the inhibitor against blood intrinsic prothrombinase activity.For anticonvertin, the inhibitor against the tissue convertin complex, the activity was found decreased to about the same level as that demonstrated for antithrombin III and II. The results lend strong support to the hypothesis that the activities measured as anticonvertin, antithrombin III and antithrombin II represent functions of the same blood protein, which on the other side appears to be distinct from antiprothrombinase. In accordance with this explanation, an antithrombin III concentrate had also antithrombin II and anticonvertin activity, and further, adsorption of a normal human serum with convertin appeared to specifically reduce its antithrombin III activity.The inhibitor against activated antihemophilic C factor (AHC’ = activated f. XI) was studied in sera adsorbed with BaS04 and celite. The inhibitor activity was found at normal level in the patients’ sera, consistent with the view that anti-AHC’ is distinct from antithrombin III, II and from anticonvertin. No acceleration of the anti-AHC’ activity could be demonstrated after addition to the inhibition mixture of weak solutions of heparin.The results are discussed.
The Hemostatic Paradox and its Present Problems
Authors: Roskam Jacques 
Published: June 2018

SummaryIn recent years great progress has been made concerning the reasons of many paradoxical data recorded in disordered arrest of bleeding. They are emphasized in the present paper where some of the still unsolved problems are merely mentioned.From the data recently disclosed, the role of platelets in hemostasis appears even more prominent than before : they are not only the building stones of the dam which stops the blood flowing from small arteries and veins, but they also bring with them in their “plasmatic atmosphere” the cement, i.e. the adsorbed blood clotting factors, which causes them to be firmly united into a sort of concrete.Then this biological concrete is transformed into a sort of armoured-concrete by means of fibrin strands originated in the free circulating plasma. These strands strengthen the hemostatic plug and fasten it more firmly to the lips of the wound.Analysis of hemorrhagic diseases discloses that besides platelet and/or blood clotting deficiencies, a peripheral factor not infrequently contributes, sometimes for a great part, to prolonged arrest of bleeding.Such analysis also confirms usual “multicausation” in disordered hemostasis.
Genetische Veränderungen des Protein-C-Systems
Authors: Pabinger Ingrid , Mannhalter Christine , Mustafa S. 
Published: June 2018

ZusammenfassungDas Protein-C-System umfaßt neben dem Protein C (PC) das Protein S (PS) sowie Thrombomodulin (TM). Obwohl das PC bereits im Jahr 1976 isoliert und charakterisiert wurde, wurde familiärer PC-Mangel erst im Jahr 1981 mit familiärer Thrombophilie in Zusammenhang gebracht. Heute wissen wir, daß PC einen der wichtigsten Inhibitoren der Gerinnung repräsentiert. Zur Umwandlung des Zymogens PC durch Thrombin in aktiviertes PC (APC) ist das TM von essentieller Bedeutung. Dieses Protein wurde 1981 entdeckt und danach intensiv in seiner biochemischen Funktion studiert. Die klinische Relevanz von TM-Defekten ist allerdings bis heute unklar. APC inaktiviert proteolytisch die aktivierten Gerinnungsfaktoren Faktor V (FVa) und Faktor VIII (FVIIIa). Zur Entfaltung der vollen Aktivität benötigt PC einen Kofaktor, das PS. Ein Mangel von PS führt zu erhöhter Thromboseneigung. Eine häufig vorkommende Mutante des Faktor V (FV), der FV-Leiden, kann durch APC nur unzureichend inaktiviert werden und ist ebenfalls mit erhöhter Thromboseneigung assoziiert. Der genaue Mechanismus über den FV-Leiden zu einem erhöhten Thromboserisiko beiträgt wird derzeit noch kontrovers diskutiert. Heute sind die biochemischen Interaktionen der Komponenten des PC-Systems recht genau untersucht und viele zugrundeliegende Mutationen aufgeklärt. Darüber hinaus gibt es recht umfangreiche Studien an großen Patientenkollektiven, in denen die Auswirkungen der Mutationen in den einzelnen Komponenten des PC-Systems auf das Thromboserisiko analysiert wurden. Die Ergebnisse mehrerer Evaluierungen werden in diesem Artikel zusammengefaßt.
Epitope Specificity of Factor VIII Inhibitor Antibodies
Authors: Scandella Dorothea 
Published: June 2018

SummaryAntibodies that inactivate factor VIII develop most frequently in patients with severe hemophilia A, and they present a serious complication in the therapy of such individuals. Most patients with inhibitors have two or more different antibodies capable of factor VIII inactivation in their plasma, as shown by assays in which several factor VIII domain fragments are tested for neutralization of the inhibitor activity. Such neutralization assays of 23 patient plasmas suggest that there are three common epitopes. These epitopes have been localized by several methods to the A2, A3, and C2 factor VIII domains. Less common inhibitor epitopes lie within the heavy chain acidic region residues 336-372 and in a second region of the C2 domain. The light chain acidic region, residues 1649-1689, may also contain an inhibitor epitope, but this remains to be confirmed. The inhibitor epitopes of autoantibody patients are more restricted as half of them have anti-C2 domain antibodies that make up 95% of the inhibitor activity. The remainder have several inhibitors similar to those of the hemophiliacs. The predominant C2 domain epitope specificity was also seen in rare cases of inhibitor development due to two heat pasteurized factor VIII concentrates in previously treated patients without inhibitors. Inhibitors in mild hemophiliacs are rare as these individuals are usually tolerant to factor VIII. When tolerance is overcome in such patients, the immune responses characterized were diverse. In some patients there was a complete loss of tolerance.