bluuebunny/crossref_metadata_2025 huggingface dataset:
Possible Role of Fibrinogen in the Aggregation of White Blood Cells
Authors: Berliner S , Fuchs J , Seligsohn U , Kariv N , Hazaz B , Rotenberg Z , Weinberger I , Agmon J , Pinkhas J , Aronson M
Published: June 2018

In order to verify whether leukocyte aggregation correlated with aggregation of other cellular elements during inflammation, we examined the state of leukocyte adhesiveness/aggregation (LAA) in the peripheral blood and red cell aggregation. Correlation was found to be significant as was the correlation between LA A and fibrinogen, and with the fibrin/fibrinogen degradation products concentration during various inflammatory states. In vitro leukocyte aggregation was decreased when the cells were suspended in autologous heat defibrinogenated plasma as compared to cells suspended in autologous native plasma. Heat aggregated fibrinogen but not native fibrinogen caused leukocyte aggregation in vitro. Finally, Arvin defibrinogenation in rabbits reduced the state of LAA in endotoxinemic rabbits. Integrating all this information, we assume that fibrinogen participates not only in the aggregation phenomena of red cells and platelets, but also in those of leukocytes.
The Isolation and Characterization of a Ternary Human Plasmin B-Chain-Streptokinase-Plasminogen Complex
Authors: Summaria Louis , Boreisha Irena , Barlow Grant H , Robbins Kenneth C
Published: June 2018

A ternary equimolar human plasmin B-chain-streptokinase-plasminogen complex was isolated from a mixture of the plasmin B-chain-streptokinase complex and human plasminogen at 0° C and 37° C. A ternary complex which was shown to be species specific, was identified and characterized by ultracentrifugal, acrylamide gel electrophoretic, and agarose double diffusion analyses. When mixed at a 1:1 molar ratio at 0° C, 39.9% of the preparation existed as a plasmin B-chain-streptokinase-plasmino-gen complex; when mixed at 37° C, 86.d% existed as a complex, which was identified by electrophoretic analyses to be a plasmin B-chain-streptokinase-plasmin complex. Sedimentation velocity analyses gave s°2o,w values of 3.79 for the plasmin B-chain-streptokinase complex, 4.10 for Lys-plasmin, and 6.23 for the plasmin B-chain-streptokinase-plasmin complex. Sedimentation equilibrium analyses gave molecular weights of 73,900 for the plasmin B-chain-streptokinase complex, 82,900 for Lys-plasmin, and 153,100 for the plasmin B-chain-streptokinase-plasmin complex. The diisopropylphosphorofluoridatc (DFP)-inhibitcd and the p-nitrophenyl-p-guanidino-benzoate (NPGB)-inhibited plasmin B-chain-streptokinase complexes both retained their ability to form a ternary complex with human plasminogen, but this complex did not convert to a plasmin B-chain-streptokinase-plasmin complex. Thus, the active site serine residue is essential for the activator activity of the plasmin B-chain-streptokinase complex, but it is not necessary for the binding of the plasmin B-chain-streptokinase complex to plasminogen to form a ternary complex.
Effect of Dipyridamole on Spontaneous Platelet Aggregation in Whole Blood Decreases with the Time After Venepuncture: Evidence for the Role of ADP
Authors: Saniabadi A R , Lowe G D O , Barbenel J C , Forbes C D
Published: June 2018

Spontaneous platelet aggregation (SPA) was studied in human whole blood at 3, 5, 10, 20, 30, 40 and 60 minutes after venepuncture. Using a whole blood platelet counter, SPA was quantified by measuring the fall in single platelet count upon rollermixing aliquots of citrated blood at 37° C. The extent of SPA increased with the time after venepuncture, with a correlation coefficient of 0.819. The inhibitory effect of dipyridamole (Dipy) on SPA was studied: (a) 10 μM at each time interval; (b) 0.5-100 μM at 3 and 30 minutes and (c) 15 μM in combination with 100 μM adenosine, 8 μM 2-chloroadenosine (2ClAd, an ADP receptor blocker) and 50 μM aspirin. There was a rapid decrease in the inhibitory effect of Dipy with the time after venepuncture; the correlation coefficient was -0.533. At all the concentrations studied, Dipy was more effective at 3 minutes than at 30 minutes after venepuncture. A combination of Dipy with adenosine, 2ClAd or aspirin was a more effective inhibitor of SPA than either drug alone. However, when 15 μM Dipy and 10 μM Ad were added together, the inhibitory effect of Dipy was not increased significantly, suggesting that Dipy inhibits platelet aggregation independent of Ad. The increase in SPA with the time after venepuncture was abolished when blood was taken directly into the anticoagulant containing 5 μM 2ClAd. It is suggested that ADP released from the red blood cells is responsible for the increased platelet aggregability with the time after venepuncture and makes a serious contribution to the artifacts of in vitro platelet function studies.
Assessment of Factor VII and Factor X
Authors: Shaw S , Pegrum G. D , Farthing C. P , Wolff S
Published: June 2018

A method is described to separate factor VII from factor X in normal serum using electrophoresis in a polyvinyl chloride block. A potent source of factor X is obtained. This may be used in correction studies and for assessment of deficiencies of factor VII in patients.
Effect of Alkaline and Acid Phosphatases on Clotting:
Authors: Iatridis P. G , Ferguson J. H
Published: June 2018

Alkaline phosphatase is found to enhance the activation of factor IX by SF. The correlation of the distribution of alkaline phosphatase in electrophoretic fractions with the clotting tests suggest that the “beta” fraction contains the responsible factor for the acceleratory effect of alkaline phosphatase on clotting.

Acid phosphatase, while not exerting a direct inhibitory effect on SF, does enhance the plasmatic anti-SF activity. The “beta” and “F-gamma” fractions seem to contain the responsible factor of acid phosphatase for the plasmatic anti-SF enhancement.

SF preparation has no acid or alkaline phosphatase activity.

A tentative schema is proposed to explain the effects of acid and alkaline phosphatase on clotting.
Some Complexities of Multiple Inhibitor Interactions in Fibrinolytic Systems
Authors: Maxwell R. E , Nawrocki J. W , Nickel Violet S.
Published: June 2018

Human or canine fibrin polymers which are structurally altered by the combined action of plasmin and EACA show an increased resistance to digestion by trypsin, but not to digestion by chymotrypsin. These observations support the concept that EACA inhibition of fibrinolysis is to a variable extent a function of structural changes in the substrate, and that the changes may be related to the susceptibility of lysyl- and arginyl-sites attacked by plasmin and trypsin, but not by chymotrypsin.

In plasma, the fibrin modification reactions mediated by plasmin + EACA are analogous to those in purified systems, with quantitative differences resulting from the presence of other inhibitors, and perhaps from earlier gelation of the developing polymers.

This complexity of the action of EACA must be taken into account in comparing its effects with those of other inhibitors, which also have variable and non-linear effects related to prevention of autodigestion of plasmin, antagonistic or potentiative combinations of inhibitors, and interference with substrate conversion.
Formation of Anticoagulants by Digesting Fibrin with Thrombin
Authors: Triantaphyllopoulos D. C , Muirhead C. R
Published: June 2018

Purified thrombin was able to digest fibrin clots in the combined presence of ε-ACA and Trasylol. The digestion products prolonged the thrombin clotting time of both fibrinogen and plasma and inhibited completely the coagulation of shed blood. The incidental observation was made that phosphate buffer elutes from Amberlite IRC-50 a nondialyzable anticoagulant which can easily be neutralized by calcium salts.
Untersuchungen über das Verteilungsmuster der Laktatdehydrogenase-Isoenzyme menschlicher Blutplättchen
Authors: Schumacher K , Schneider W , Gross R
Published: June 2018

Mit Hilfe der Polyacrylamid-Disc-Elektrophorese wurde das LDH-Isoenzymver-teilungsmuster normaler menschlicher Blutplättchen untersucht und eine Verteilung mit starkem Überwiegen der Banden 2 und 3 bei deutlich geringerem Anteil der LDH-1 gefunden. LDH-4 konnte nur in Spuren, LDH-5 in diesem System nicht nachgewiesen werden. Folgende Anteile wurden für die einzelnen Isoenzyme bestimmt (x ± s, n = 16): LDH-1 = 9,8 ± 7,3, LDH-2 =50,7 ± 7,7, LDH-3 = 38,3 ± 7,5, LDH-4 = 1,2 ± 1,2 rel. %.
Properties of Microsomal Activator of Profibrinolysin Found in Bovine and Porcine Heart Muscle
Authors: Nakahara M , Celander D. R
Published: June 2018

Mitochondrial, lysosomal, and microsomal fractions of pig and cow myocardial cells were screened for their ability to effect lysis of bovine fibrin plates prepared with Profibrinolysin-containing and profibrinolysin-free reagents. Little if any activity was observed on profibrinolysin-free fibrin plates. Maximum activity on Profibrinolysin-containing plates was found in association with the microsomes. Extraction of the microsome preparations with 0.15 M KCl and 2.0 M KCl dissolved activator molecules with different pH solubility and stability characteristics. The activator activity of the 2.0 M KCl extract was in general more stable to acid pH than that of the 0.15 M KCl extract.

The activator characteristic of the microsomal suspensions and of both types of microsome extracts was stable to acetone precipitation. However, the 2.0 M KCl extract lost its relatively greater stability to acid pH when precipitated with acetone. The significance of the chemical environment as a determining factor in final properties of purified enzyme molecules is discussed. The importance of using a relatively homogeneous cell population as starting material is also emphasized.
Coagulation Studies on Separated Fibrinogen Break-down Products
Authors: Gormsen J , Laursen B
Published: June 2018

Fibrinogen break-down products obtained by plasmindigestion in vitro (human material) are separated by column chromatography on DEAE-Sephadex. The various fractions are defined immunologically and by means of disc acrylamide electrophoresis. A plasminsensitive and a plasminresistant fraction exhibiting E- and D-antigenic properties respectively significantly inhibit some early stages of bloodcoagulation, when present in the final concentration of 5–25 mg%. Some other labile intermediates were less active. No significant prolongation of plasma thrombin time is obtained using separated D- or E-fractions even in final concentration of 100 mg%.
Modification of the Fibrin Agar Plate for Measurements of the Components of the Fibrinolytic System
Authors: Wolf P
Published: June 2018

The optimal conditions for plasminogen activation by intrinsic activator (IA) were found on Type II human fibrin agar plates made with .04 M pH 8.5 NH4 acetate buffer.

Intrinsic activation inhibitor (IAI) produced central areas of lysis inhibition.

Methods of quantitating IA and IAI were developed. Activator measurements showed :

1. Undiminished IA concentrations in plasma and serum stored for 3 weeks at + 4° C.

2. 60–80% loss of IA during euglobulin precipitation at pH 5.2 and at pH 6.

3. Presence of a plasminogen activator in commercial thrombin preparation. Inhibitor measurements showed:

1. Decrease of IAI in plasma and serum after 4 days storage at +4° C.

2. A physiological decrease of IAI in late pregnancy.

3. That IAI was composed of either larger or more asymmetrical molecules than either plasminogen or IA.
The Effects of Infusing Thrombin and Its Acetylated Derivative
Authors: Pechet L , Engel A. M , Goldstein C , Glaser B
Published: June 2018

Summary and Conclusions

Dogs and rabbits were infused with acetylated thrombin (thrombin E) and clotting thrombin (thrombin C). Similar effects were noted in both animal series. Very large amounts of thrombin E could be tolerated, but resulted in defibrination. Following a transient hypercoagulable state, the blood became unclottable. The platelets and factors I, V, and VIII were markedly decreased. Factor II was moderately affected and factor VII-X showed no significant changes in most experiments. The presence of fibrinogen degradation products was indicated by a delay in the polymerization of fibrin monomers.

Based on the shortening of the euglobulin lysis time, a decrease in the proactivator, and the appearance of inhibitors of fibrin monomer polymerization, it is concluded that transient fibrinolysis is induced by the infusion of thrombin. Its immediate mechanism could not be determined.
Formation, Consistency and Degradation of Artificial Thrombi in Severe Renal Failure
Authors: Dintenfass L , Stewart J. H
Published: June 2018

A 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

The 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

This 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

In 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

Oral 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

It 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

Experiments 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

A 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

1. 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

Adenosine 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

A 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

Platelet 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

In 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

A 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

Natural 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

In 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

Das 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

Antibodies 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.
Molekulare Diagnostik des von-Willebrand-Syndroms
Authors: Budde U. , Schneppenheim R. , Bergmann Frauke
Published: June 2018

Seit der Erstbeschreibung des von-Willebrand-Syndroms (vWS) im Jahre 1926 durch Erik Adolf von Willebrand als »Hereditär Pseudohemofili« schaffte erst die Verfügbarkeit moderner hämostaseologischer und molekularer Methoden die Voraussetzung für die heutigen Kenntisse über Pathophysiologie und Genetik der zugrundeliegenden quantitativen, qualitativen und molekularen Defekte. Die ausgeprägte Heterogenität der klinischen Symptome und Laborparameter korrespondiert mit der Natur und der Lokalisation molekularer Defekte in definierten Regionen des multifunktionellen von-Willebrand-Faktors (vWF). Die exakte Charakterisierung der betroffenen Patienten mittels konventioneller und spezieller hämostaseologischer Methoden ist die essentielle Voraussetzung für die Auswahl der adäquaten Strategie zur weiteren molekularen Analyse. Das diagnostische Procedere zur Klassifikation und die insbesondere in Deutschland häufigsten Mutationen des von-Willebrand-Faktors werden dargestellt.
Thienopyridine (Ticlopidin, Clopidogrel)
Authors: Weber A.-A. , Schrör K.
Published: June 2018

Thienopyridine (Ticlopidin und Clopidogrel) hemmen spezifisch die ADP-medi- ierten Mechanismen der Thrombozytenaktivierung. Der genaue molekulare Wirkmechanismus der Thrombozytenfunktionshemmung durch Thienopyridine ist nicht bekannt. Nach bisherigen Daten beruht das wirksame Prinzip auf einer nichtkompetitiven und möglicherweise irreversiblen Reduktion der ADP-Rezep- tordichte auf Thrombozytenmembranen. Im Gegensatz zu früheren Annahmen, nach denen Thienopyridine »Prodrugs« sind und für ihre Wirksamkeit einer hepatischen Bioaktivierung bedürfen, konnte in neueren Arbeiten eine ln-vitro- Wirksamkeit dieser Substanzen nachgewiesen werden. Klinisch weisen die Thienopyridine eine gut gesicherte Wirksamkeit auf. So zeigte Clopidogrel in der kürzlich publizierten CAPRIE-Studie bei Patienten mit symptomatischer Atherosklerose eine geringe aber statistisch signifikante Überlegenheit gegenüber Acetylsalicylsäure hinsichtlich der Prävention von Schlaganfall, Myokardinfarkt und vaskulärem Tod. Neutropenien, wie sie unter Ticlopidin bei etwa einem Prozent der Patienten beobachtet werden, traten unter Clopidogrel nicht auf. Dennoch muß das Nebenwirkungsprofil dieser im Vergleich zur Acetylsalicylsäure noch jungen Substanz sorgfältig beobachtet werden.
Canine Hemophilia
Authors: Didisheim Paul , Bunting Dorothy L.
Published: June 2018

A new canine hemophilia kindred is reported.
On the Combined Administration of Streptokinase and Pancreatic Trypsin Inhibitor
Authors: Verstraete M , Vermylen J , Vermylen C , De Vreker R. A
Published: June 2018

Preliminary results on the modification of blood fibrinogen level and plasma plasminogen value and fibrinolytic activity during combined administration of streptokinase and pancreatic trypsin inhibitor are presented. Not only fibrinogen fall but also plasminogen depletion is inhibited.
A Standard Preparation of Bovine Fibrinogen
Authors: Landaburu Ricardo H. , Curtino Juan
Published: June 2018

The correlation of values given by different research laboratories that work on blood coagulation is difficult on account of the difference of reagents used. Fibrinogen is the most important source of variations in results when research is done using purified substances. A reproducible procedure that gives a stable and sensitive bovine fibrinogen is given. The material obtained has been studied on its properties.
Fibrinolysis and Fibrinogen Breakdown Products (Antithrombin VI) in Renal Venous Blood (RVB) in Dog
Authors: Worowski K , Niewiarowski S , Prokopowicz J
Published: June 2018

The authors investigated fibrinolytic system of renal venous blood (RVB) peripheral venous blood (PVB) in normal dogs and in those with kidney injury produced by mercury chloride. An increase of fibrinolytic activity as well as a decrease of the level of plasminogen and fibrinogen were found in RVB plasma of normal dogs. An inhibition of the fibrinolytic activity was found in intoxicated dogs in both RVB and PVB plasmas, followed by an increase of plasminogen and fibrinogen levels. The occurence of fibrinogen breakdown products, antithrombin VI, was demonstrated in RVB plasma of normal dogs. It does not appear in RVB plasma of intoxicated dogs.

On the basis of experimental results an important role of urokinase, secreted by the kidney into the general circulation is suggested as regards the maintenance of the coagulation and fibrinolysis balance in the organism as well as in the fibrinogen and plasminogen catabolism.

It has been also concluded that the antithrombin VI, formed in the kidney circulation is a natural inhibitor of blood coagulation appearing in physiological conditions.
Experimental Venous Thrombosis in Alloxan Diabetic Rats
Authors: Nordöy Arne
Published: June 2018

Summary and Conclusions

1. The effect of alloxan diabetes on thrombus formation has been examined in rats using a standardized damage of the jugular vein. No significant increase in the incidence of thrombosis as compared with the control group was observed.

2. An accelerated recalcification time, cephalin time and thromboplastin time was observed, as well as an increase in the levels of fibrinogen, factor VII and factor VIII.

3. The ADP-induced platelet adhesiveness in platelet rich plasma was decreased, possibly indicating a decrease in anti-Willebrand factor.

4. A slight increase in total cholesterol, free fatty acids and triglycerides in plasma was observed.

5. It is concluded from the present study that a thrombotic condition is not present in alloxan diabetic rats, although the activity of some coagulation factors is increased. The reason for this may be the decreased ADP-induced platelet adhesiveness in plasma.
Rôle of Thrombin in Prothrombin Activation
Authors: Seegers W. H , Schröer H , Heene D
Published: June 2018

The partial thromboplastin time and purified thrombin were used to demonstrate the procoagulant power of thrombin. Only 0.007 μg of thrombin could be detected in prothrombin activation. Traces of thrombin and autoprothrombin C can fully account for the generation of procoagulant activity in the thromboplastin generation test. Inactivation of these two activities by antithrombin explains the disappearance of the procoagulant power in that test, so that there now remains no valid demonstration of the existence of plasma thromboplastin or of anti-plasma thromboplastin.
Zur Messung der Thrombozytenadhäsivität
Authors: Breddin K
Published: June 2018

Es wird eine neue Methode zur Bestimmung der Thrombozytenadhäsivität beschrieben, bei der die Thrombozyten im unverdünnten Nativplasma gezählt werden. Die an der Wand einer Bürkerkammer nach einer Kontaktzeit von 10 Minuten mit unverdünntem Plasma anhaftenden Thrombozyten werden ebenfalls gezählt. Aus beiden Zahlen wird ein Adhäsivitätsindex ermittelt. Mit der Methode ist neben der Ermittlung der Plättchenadhäsivität eine Beurteilung der spontan auftretenden Plättchenaggregation und -agglutination möglich. Bei 30 Normalpersonen fand sich ein arithmetrischer Mittelwert von 1,24 bei einer Schwankungsbreite von 0,57-2,7. Bei 30 Patienten mit einer gesteigerten Thrombozytenagglutination (ermittelt durch den Agglutinations-test η. Breddin u. Bauke) fand sich ein Mittelwert von 1,93 bei einer Schwankungsbreite von 0,69-4,60. Die verminderte Thrombozytenadhäsivität bei der von Willebrandschen Erkrankung konnte bei 2 Patienten durch Inkubation des thrombozytenhaltigen Patientenplasmas mit plattchenfreiem Normalplasma normalisiert werden. Bei einem dieser Patienten war nach Übertragung von Cohnscher Fraktion I die Plättchenadhäsivität vorübergehend gesteigert. Die Beziehungen zwischen Thrombozytenadhäsivität und Thrombozytenstoff-wechsel sowie den Eigenschaften der verwendeten Kontaktflächen werden diskutiert. Insbesondere wird auf die durch Aggregation und Agglutination bedingte gesteigerte Thrombozytenadhäsivität und ihre Bedeutung für die Entstehung und Erkennung von Gefäßkrankheiten hingewiesen.
Thrombolyse: Direktbestimmung fibrinolytischer Substanzen durch die statische Retraktrometrie
Authors: Schulte W
Published: June 2018

Durch die statische Messung der Retraktionskraft in Abhängigkeit von der Zeit können Veränderungen der Fibrinbildung und die Fibrinolyse bestimmt werden. In einem hinsichtlich Konstruktion und Gebrauch genau beschriebenen Versuchsgefäß kann man die Gerinnseloberfläche zu einem gewünschten Zeitpunkt während oder nach Abschluß der Retraktion fìbrinolytischen Substanzen aussetzen. Unter gleichzeitiger und fortlaufender Messung läßt sich die Konzentration dieser Substanzen verändern. Erste - statistisch noch ungesicherte - Ergebnisse deuten auf eine unterschiedliche Lysegeschwindigkeit und Intensität in Abhängigkeit von der primären Streptokinasekonzentration hin. Bei gleicher Endkonzentration in zwei Gefäßen ist der lytische Effekt geringer, wenn die Endkonzentration durch zweimalige Streptokinasezugabe in zeitlichen Abstand eingestellt wird. - Neben einer genauen Beschreibung der Versuchstechnik wird auf weitere Möglichkeiten der Methode hingewiesen.
Standardisierung von Tests – Erfassung von Störungen im »intrinsic System« der Blutgerinnung unter den Bedingungen der maximalen Kontaktaktivierung mit Celit
Authors: Voss D
Published: June 2018

Es werden die Variablen bei einigen Bestimmungsmethoden des »inneren Systems« der Blutgerinnung aufgezeichnet und ihre weitgehende Standardisierung angestrebt. Unter diesem Gesichtspunkt führten wir die maximale Kontaktaktivierung mit Celit-Puder für die Globaltests, Rekalzifizierungszeit und Kephalinzeit und die spezifischen Bestimmungsmethoden für Faktor VIII und Faktor IX ein. Aufgrund dieser Standardisierung der Kontaktaktivierung ist eine gute Reproduzierbarkeit der Werte zu erzielen. Es läßt sich auch durch diese Technik eine gute Korrelation zwischen Rekalzifizierungszeit bzw. Kephalinzeit und dem Gehalt an Anti-Hämophilie A- oder B-Faktor ablesen.
Abnormal Plasma Clots in Hemophilia
Authors: Bettigole Richard E. , Hampton James W. , Bird Robert M.
Published: June 2018

Summary and Conclusions

A technique is described for the examination of thin plasma clots with the electron microscope, by which the clots of nine patients with classical hemophilia and five normal controls were studied. The hemophiliacs’ plasma clots were strikingly different from normal, with relatively straight, wide fibrin strands. This difference appeared to be due to their long clotting times. It is proposed that this abnormal end-product of fibrin polymerization in hemophilia, perhaps together with the decreased platelet clumping which also was observed, may be a cause of the functional inadequacy of blood clots in hemophilia.

Presented in part in abstract, Clinical Research 11: 190, 1963 and clinical Research 11: 293, 1963.
Method for Determining Antiheparin Activity of Platelets and Erythrocytes
Authors: Poplawski A , Niewiarowski S
Published: June 2018

A method for determining antiheparin activity of platelets and erythrocytes is described. The neutralization of various concentrations of heparin by various amounts of protamine sulphate or tested material is measured simultaneously. Results are expressed in mean equivalent of protamine sulphate (PS) standard solution. The normal values of antiheparin activity of platelets and erythrocytes in human and in various animals are given.
Kinetic Aspects of the Interaction of Blood Clotting Enzymes
Authors: Hemker H. C , Hemker P.W , Loeliger E. A
Published: June 2018

Application of the methods of enzyme-kinetic analysis to the results of clotting tests is feasible and can yield useful results. However, the standard methods of enzyme kinetics are not applicable without modifications imposed by the peculiarities of the blood-clotting enzyme system. The influence of the following complicating circumstances is calculated :

1. Substrate is not present in excess.

2. Only relative measures exist for concentrations of substrate or enzymes.

3. Enzymes and substrates are often added together.

4. Reagents are not pure.

5. Clotting-time is our only measure for clotting-velocity.

Formulas are deduced, which makes it possible to recognize the effect of these complications.