bluuebunny/crossref_metadata_2025 huggingface dataset:
Clotting Activity of Platelet Phospholipids in Rat and Man
Authors: Gautheron P , Dumont E , Renaud S
Published: June 2018

The clotting activity of man and rat platelet phospholipid fractions separated by bi-dimensional TLC, resuspended in Tyrode by sonication, was studied in the recalcification (manual) and in the Stypven (recalcification plus Russell’s viper venom) clotting time (determined in a coagulometer). Phosphatidyl serine was the most active fraction to shorten the two clotting tests utilized, in both rat and man, but it was much more effective in the Stypven time. The phosphatidyl ethanolamine was the second most active fraction, in the Stypven time; this fraction was almost as active as phosphatidyl serine in both animal species. The other fractions studied (phosphatidyl inositol, phosphatidyl choline and sphingomyelin) were sligthly active or not active, depending on the experimental conditions.

The clotting activity of platelet phosphatidyl serine from rat, at concentrations corresponding to platelet counts from 1 to 10 ( X105), was much smaller than this of the disrupted (sonicated) platelets from which it originated. However, the clotting activity of sonicated platelets could be completely reproduced, either at each concentration studied (Stypven time) or at a concentration corresponding to lOxlO5 platelets (recalcification time), by adding to phosphatidyl serine the other four phospholipid fractions (phosphatidyl inositol, phosphatidyl ethanolamine, phosphatidyl choline, sphingomyelin) dispersed in a homogeneous way by sonication.

The feeding of a butter-rich diet to rats considerably increased the activity of each of the platelet phospholipid fractions in the two clotting tests carried out.
Action of Trypsin on Amidinated Fibrinogen
Authors: Phillips H. M , York J Lyndal
Published: June 2018

A study of the action of trypsin on fibrinogen with lysine side chains chemically blocked by amidination was undertaken to determine whether trypsin attacks arginine or lysine linkages in fibrinogen in order to render it nonclottable. The data suggests that trypsin attacks arginine site(s).
A Haematocrit Corrected Micro Determination of the P&P-Test and Blood Clotting Factors in Capillary Blood
Authors: Petrich C , Pothmann R , Döhmen A , Voss H. v , Göbel U
Published: June 2018

A new micro test for the determination of the P &P-test, and the factors II, V, and VII is described. The advantage of the new test is the possibility to discontinue the separation of the erythrocytes and the plasma. It only presumes the determination of the patient’s haematocrit, which is considered in the dilution of the blood sample. The results are not influenced by different haematocrits. They give excellent information on normal and pathologic coagulation activities, what is shown in three different groups of patients varying with respect to their age and partially receiving phenprocoumarol.
Heparin in the Treatment of Pulmonary Thromboembolism
Authors: Kanis John A.
Published: June 2018

A retrospective survey of patients admitted to hospital with pulmonary thromboembolism during 1971 is reported, and the methods of treatment commonly used are compared. The outcome in these patients was also compared with those receiving supportive therapy.

The use of oral anticoagulants with or without the addition of heparin for the first 72 hours resulted in a significant reduction in mortality by decreasing the incidence of further fatal thromboembolism. These regimens did not significantly decrease the total number of further thromboembolic complications. Treatment with prolonged infusion of heparin without oral anticoagulants resulted in a significant reduction of both thromboembolic morbidity and mortality.

Despite the difficulties of valid comparisons between methods of treatment of pulmonary thromboembolism, it is concluded that the superiority of continuous heparin infusion justifies the need for a prospective assessment of the optimum length of treatment with heparin infusion.
The Effect of Factor XIII on Wound Granulation in the Rat
Authors: Marktl W , Rudas B
Published: June 2018

The effect of exogenously applied factor XIII on wound healing was studied, using a special wound granulation model. It has been found that great amounts of factor XIII are able to improve the wound granulation. The manner of application, i.e. local or intravenous, seems to be without influence. Possible connections between factor XIII and wound healing are discussed. The reason for the improved wound healing after application of great quantities of factor XIII remains unclarified.
The Resistance of Soluble Derivatives of Fibrinogen and the Sensitivity of Its Insoluble Forms to Fibrinolytic Degradation in Blood
Authors: Gurewich Victor , Nowak Andrzej , Lipinska Izabella , Lipinski Boguslaw
Published: June 2018

The effect of naturally induced fibrinolytic activity on fibrinogen and certain soluble and insoluble derivatives was studied. Experiments were performed on blood removed after venous occlusion of the arm and immediately after death. A previously described electrophoretic method was used by which the heterogeneity of fibrinogen can be demonstrated directly in intact plasma. It was shown that fibrinogen, soluble fibrin monomer (FM) complexes and fibrin degradation products are resistant to degradation by naturally-induced fibrinolytic activity. By contrast, rapid lysis of fibrin, protamine sulfate (PS) precipitated fibrinogen, and PS and ethanol induced gels of FM occurred. The observations are believed relevant to our understanding of the pathway of fibrinogen and FM catabolism and the interpretation of the origin of serum FDP.
Intrinsic Activation of Prothrombin Potentiated by Celite and Reduced by Kaolin
Authors: Kang E. P , Triantaphyllopoulos D. C
Published: June 2018

Preparations of human prothrombin complex were absorbed with celite or kaolin and the 10% sodium chloride eluate of both absorbents was tested for its effectiveness to correct the prolonged partial thromboplastin time of celite-exhausted plasma. Both types of eluate were effective, indicating the presence of contact factors in the prothrombin preparations. Activation of the absorbed prothrombin complexes via the intrinsic pathway showed that while the kaolin absorbed preparations generated less thrombin than the parent solutions, celite absorbed complexes generated more thrombin than before they were absorbed. Both types of absorbed preparations generated the same amount of thrombin as before absorption when they were activated via the extrinsic pathway. When the absorption of the contact factors was performed by the addition of celite in the plasma before the purification of the prothrombin complex, the prothrombin preparations obtained generated less thrombin via the intrinsic pathway than the preparations which were obtained from plasma which had not been treated with celite.
Indirect Measurement of Streptokinase Concentration in the Plasma of Patients Undergoing Fibrinolytic Treatment
Authors: Martin M
Published: June 2018

A new method of determining streptokinase concentrations on a quantitative basis in the plasma of patients undergoing streptokinase infusion is demonstrated. The principle of this method is based on the clot lysis time recorded by the thrombo-elastograph. The test clot constituents were bovine fibrin, bovine plasminogen, human euglobulin, EDTA, human plasma (with unknown streptokinase quantity) and thrombin. As plasminogen (euglobulin) and fibrinogen were present in the test coagulum in rather high concentrations (fixed excess) no interference with changing plasminogen and fibrinogen levels of the patient’s plasma was observed. Further, due to high EDTA concentrations, no interaction with platelet functions and coagulation factors took place. The standard error of measuring 5 u of streptokinase in one ml of human plasma was determined at s = ±0.47 u/ml.

Eleven patients undergoing fibrinolytic treatment with streptokinase were monitored by streptokinase determination in the plasma. In this group of patients, streptokinase concentration values varying between 15 and 0.5 units/ml plasma were measured. One striking feature was the continuous decrease in streptokinase concentration in the plasma, in spite of unchanged streptokinase infusion rates. This observation was consistent in regimens with both large (100,000 u/h) and small (30,000 u/h) streptokinase infusion rates. No explanation is available for this observation up to now. A rise in circulating anti-streptokinase contents was precluded. Possibly, an accelerated streptokinase metabolism rate in the course of long-term streptokinase administration may be involved.
Decreased ATP, ADP and Serotonin in Young Platelets of Fawn-Hooded Rats with Storage Pool Disease
Authors: Tschopp Th B. , Weiss H. J
Published: June 2018

The bleeding diathesis and abnormalities of platelet aggregation in the Fawn-Hooded (FH) rat, as in human patients with storage pool disease, have been attributed to decreased amounts of adenine nucleotides that are ordinarily stored with serotonin in the platelet dense granules. This study was undertaken in order to establish whether the platelet defect of the FH rat was present in young platelets, newly emerged from the bone marrow, or whether the platelets acquired this abnormality (possibly by a premature release reaction) during their circulation in the blood. FH and Wistar rats were made thrombocytopenic with one injection of anti-platelet serum (APS) and platelets were harvested during the recovery phase. The ATP content of “young” FH platelets harvested two days after injection of APS, was higher than that of platelets obtained from untreated FH rats, but was still only 50% of that found in “young” Wistar platelets. In addition, the adenine nucleotide content of FH platelets did not change during treatment with aspirin. “Young” FH platelets were also deficient in serotonin and, unlike Wistar platelets, their serotonin content did not increase appreciably with the increasing platelet age. The results of the study strongly suggest that the defect in FH platelets is present in platelets newly emerged from the bone marrow and is not due to premature release of the “storage” contents during their circulation in the blood.
Evidence for Ca2+ Regulated Magnesium ATPase of Thrombosthenin (Platelet Actomyosin)
Authors: Mahendran C
Published: June 2018

The isolation of an actomyosin-like protein from platelets with a Ca2+ sensitive component is described. The addition of 1 mM EGTA results in approximately 40% and 75% inhibition of the Mg-ATPase activity depending on the mode of isolation. The inhibition can be released by a free Ca2+ concentration of 3×l0-6 M. Superprecipitation is also inhibited by 1 mM EGTA and restored in the presence of 10-5 M free Ca2+.
Measurement of the Platelet Response to Laserinduced Microvascular Injury
Authors: Hovig T , McKenzie F. N , Arfors K.-E
Published: June 2018

Microvascular injury was produced in rabbit mesentery and ear chamber preparations using a biolaser. Ultrastructural studies of the injury sites revealed damage to the endothelium which showed cytoplasmic swelling and flocculation. Complete destruction of the endothelium was not observed, indicating that sub endothelial structures were not exposed to blood flow. Microvascular thrombi which occurred at the sites of injury were composed of platelets which in general were loosely packed and showed minor alterations in shape and internal structure. Erythrocytes appeared to be heavily damaged by the laser injury. Fibrin was not observed. It is concluded that ADP may be released from red blood cells, and possibly from other sources, as a result of the laser injury, and that the platelet thrombus formation is induced by ADP.
The Plasminogen-Plasmin System Part VIII On the Mechanism of Chemical Induction of Fibrinolysis Isolation of a Latent Plasminogen Activator from Human Plasma
Authors: Tomikawa Munehiro , Abiko Yasushi
Published: June 2018

A component, responsible for the chemical induction of fibrinolysis by flufenamate, was isolated from human plasma. The isolation procedures included removal of euglobulin precipitate from plasma, Sephadex G-200 gel filtration of the euglobulin- supernatant fraction and isoelectric focusing. The partially purified component was immunologically distinct from ßioglobulin, plasmin and plasminogen. Plasminogen activator activity was liberated from the component by treatment with flufenamate. The mechanism of induction of fibrinolysis by flufenamate is discussed.
Factors Regulating Plasma Protein Synthesis
Authors: Bocci V , Pacini A
Published: June 2018

The intravenous injection of a large amount of homologous fibrinogen in the rabbit produces typical changes in the level of circulating fibrinogen. The first peak is due to the administered fibrinogen while the second, occurring after 16 hr, is interpreted as being due to the stimulation of hepatic synthesis and release of preformed fibrinogen. This typical profile was obtained with different fibrinogen preparations but not with heterologous fibrinogen. Neither was it obtained after administration of homologous γ-globulin, α-globulin or albumin. Assuming that enhancement of hepatic synthesis might be due to fibrinogenolytic products, the effect of the injection of fibrinogen digest products (FDP) was investigated. Administration of homologous FDP causes, within 24 hours, a significant increase of the plasma fibrinogen level. The critical requirement of injecting either the protein solution or saline intravenously rather than subcutaneously is emphasized. In conclusion, FDP appear to be endowed with the novel property of stimulating fibrinogen synthesis and possibly of causing the release of preformed fibrinogen.
Amount of Fibrin in Different Organs after Intravenous, Intraportal and Intraaortal Injection of Thrombin in the Rat
Authors: Busch Christer , Saldeen Tom
Published: June 2018

The effect of intravenous, intraaortal and intraportal injection of thrombin on the distribution of intra vascular fibrin in various organs was determined by a quantitative method in the rat. It was found that the major part of the fibrin was trapped in the lungs irrespective of the route of administration of the thrombin.

These results suggest that in thrombin induced intravascular coagulation most of the coagulation occurs on the venous side of the circulation.

This mechanism may be an explanation for the fact that certain organs more often contain intravascular fibrin than others at autopsy.
Ethanol Gelation and Protamine Sulfate Tests
Authors: Jacobsen Carl D. , Southers Nancy J.
Published: June 2018

Plasmas collected with Trasylol and EACA were studied for fibrin formation in the ethanol gelation and protamine sulfate tests. The latter test was difficult to read and a solid gel was rarely found, even when a definite solid gel was apparent in the ethanol gelation method. The protamine sulfate test is also said to record split products of fibrin. However, if hirudin was added to mixtures of plasma and fibrin digestion products, protamine sulfate did not cause gel formation, indicating that thrombin (or formation of thrombin) was necessary also for the gel formation induced by split products.

The protamine sulfate and ethanol gelation tests have several limitations. Care should be taken to avoid uncritical interpretations of results obtained with these tests.
Cold Promoted Activation of Factor VII
Authors: GJØNNÆSS H
Published: June 2018

Spontaneous cold promoted activation of factor VII was independent of the fibrinolytic activity of plasma and caused no activation of plasminogen.

After the spontaneous cold activation a highly significant increase in the proteolytic capacity was observed which was not seen after induced cold activation.

Cold activation induced with known prekallikrein activators (EACA, kaolin, Li- quoid) or with a semipurified plasma kallikrein preparation was independent of the fibrinolytic activity of plasma and caused no change in this.

Cold activation induced with urokinase and with streptokinase was probably mediated by plasmin. The urokinase induced activation of plasminogen was independent of factor XII, whereas this factor was a prerequisite for the cold activation of factor VII.

The urokinase induced cold activation of factor VII correlated with increased TAME - esterolytic activity and an 80 per cent decrease of the kininogen concentration, indicating activation of the plasma kallikrein system.
The Effect of Some Platelet Aggregating and Potential Thrombosis-Promoting Substances on the Development of Experimental Arterial Thrombosis
Authors: Hladovec J
Published: June 2018

A series of platelet aggregating or potentially thrombosis-promoting agents was administered intravenously 1 minute before the electric provocation of thrombosis in the carotid artery of the rat. Adenosine diphosphate, adrenaline, thrombin, ellagic acid, tannin, ε-aminocaproic acid and Trasylol were ineffective in shortening the time of thrombosis. On the contrary, most of these drugs showed some antithrombotic effect. Only 5-hydroxytryptamine definitely potentiated the process of thrombosis.
The Determination of Platelet Aggregation by Filtration Pressure in Circulating Dog Blood
Authors: Broersma R. J , Dickerson G. D , Sullivan M. S
Published: June 2018

A reproducible method is described for quantitating either spontaneous or ADP- induced platelet aggregation in circulating dog blood after heparinization. An extra- corporeal shunt containing screen material with openings 53 microns square was placed in the dog’s arterial circulation. The blood pressure was measured proximal to this filter. The blood pressure decreased upon opening the shunt to the circulation and increased when the filter became occluded. The degree and rate of aggregation was determined by means of measuring these blood pressure changes. Phase and electron microscopy demonstrated platelet aggregates occluding the filters. Platelet aggregation on the filter was experimentally accelerated by infusing ADP before the filter. The administration of ADP in concentrations between 0.625 and 10 μg/ml until occlusion, produced a dose response relationship between log of ADP concentration and rate of filter occlusion. Macrodex, a known inhibitor of platelet aggregation was given intravenously and was found to delay filter occlusion. Similar results were obtained with high intravenous doses of phenylbutazone. The method was used to compare the drug effects with their in vitro effects measured photometrically. It would appear that this technique can be used for demonstrating and quantitating the effects of drugs on the process of platelet adhesion and aggregation in vivo.
Amidase Activity of Urokinase I. Hydrolysis of a-N-Acetyl-L-Lysine p-Nitroanilide
Authors: Petkov D , Christova E , Karadjova M
Published: June 2018

α-N-acetyl-L-lysine p-nitroanilide (ALNA) was synthesized as a low-molecular weight model of the natural urokinase substrate plasminogen. Urokinase was found to catalyse anilide bond cleavage. The extent of hydrolysis can be followed spectro- photometrically by using the strong absorption band of one of the products p-nitro- aniline. An accurate, continuous and convenient assay for urokinase is proposed. As determined by the kinetic study, Vmax5 a measure for the sensitivity of an assay, is about 8 times higher than that obtained for the most sensitive urokinase ester substrates. This was demonstrated by its use for tracing the elution of urokinase during the purification of the enzyme by column chromatography.

The high apparant Km value obtained is discussed in terms of the mechanism of serine proteinase action on esters and amides.
Release of Fibrinopep tides from Fibrinolytic Fibrinogen Fragment E
Authors: Peyer A , Straub P. W
Published: June 2018

Purified “terminal” proteolytic E fragments of fibrinogen and fibrin as produced by plasmin digestion were treated with thrombin. Thrombin treatment of fragment E obtained from fibrinogen, liberated both fibrinopeptides A and B and sometimes AP. Thrombin treatment of fragment E obtained from Reptilase-clotted fibrin liberated only fibrinopeptide B. From fragments E derived from thrombin-clotted fibrin as well as from fragments D obtained from either fibrinogen, thrombin-fibrin or Reptilase - fibrin no fibrinopeptides could be recovered.
The Local Sanarelli-Shwartzman Phenomenon in Rats Induced by Human Leukaemic Cells
Authors: Lisiewicz J , Pituch A , Litwin J. A
Published: June 2018

The local Sanarelli-Shwartzman phenomenon (SSP-L) in the skin of 30 rats was induced by an intr a cutaneous sensitizing injection of leukaemic leucocytes isolated from the peripheral blood of patients with chronic lymphocytic leukaemia (CLL), acute myeloblastic leukaemia (AL) and chronic granulocytic leukaemia (CGL) and challenged by an intravenous injection of 100(μ of E. coli endotoxin. SSP-L was observed in 7 rats after injection of CLL lymphocytes and in 6 and 2 rats after AL myeloblasts and the CGL granulocytes, respectively. The lesions in the skin after AL myeloblasts appeared in a shorter time and were of longer duration compared with those observed after CLL lymphocytes and CGL granulocytes. Histologically, the lesions consisted of areas of destruction in the superficial layers of the skin ; the demarcation line showed the presence of neutrophils, macrophages and erythrocytes. Haemorrhages and fibrin deposits near the demarcation line were larger after injection of CLL lymphocytes and AL myeloblasts than after CGL granulocytes. The possible role of leucocyte procoagulative substances in the differences observed have been discussed.
Platelet Fc Receptor as a Mechanism for Ag-Ab Complex-induced Platelet Injury
Authors: Israels E.D , Nisli G , Paraskevas F , Israels L.G
Published: June 2018

Antigen-antibody complexes immunologically unrelated to platelet antigens may produce thrombocytopenia in vivo and platelet aggregation and release in vitro. An in vitro platelet system (rabbit and human) was used to study the platelet receptor that mediates the attachment of the immune complex. Platelet aggregation induced by 7 S immune complexes or aggregated gammaglobulin was blocked by prior exposure of the platelet to isolated antibody Fc. Fab from the same antibody was not inhibitory. 5S complexes lacking the Fc piece did not produce aggregation. Serum, as a source of complement was included in the rabbit platelet test system. However, the role of complement is thought to be secondary as it did not bind to platelets in the absence of 7 S complexes and was fixed only secondarily to 7 S binding. On the basis of these studies it is suggested that the platelet membrane contains an Fc receptor and that the primary fixing of immune complexes to the platelet is through the antibody Fc rather than by complement mediated non-specific immune adherence. Antibody Fc fixation to the Fc receptor site of the platelet is probably the common pathway for platelet injury induced by a number of antigen-antibody complexes immunologically unrelated to the platelet.
Influence of Pregnancy and Oral Contraceptives on Platelets in Relation to Coagulation ancl Aggregation
Authors: Lecompte F , Renaud S
Published: June 2018

Holtzman rats, 16 to 19 days pregnant, exhibited in vitro hypercoagulability with a 27 % reduction in the plasma clotting time (PCT) (siliconized and plastic) as compared to non-pregnant controls. This hypercoagulability was entirely due to an increased activity of platelet factor 3, since a comparable reduction in the clotting time was obtained when the washed platelets from these animals were resuspended in a standard platelet-poor plasma. In contrast to this, when the platelets in the original plasma were replaced by a phospholipid suspension, the clotting time in plastic but not in glass, was prolonged in pregnant rats, suggesting a decreased activity of the contact system. In addition, the pregnant rats exhibited a marked increased susceptibility of platelets to thrombin and to ADP-induced aggregation.

In 6 pregnant women and in 9 women taking contraceptives, a highly significant in vitro hypercoagulability was also present, since the PCT was decreased 26% and 22%, respectively, as compared to the 14 controls. This hypercoagulability appeared to be entirely due to the increased activity of platelet factor 3 as in rat. However, the clear-cut increased susceptibility of platelets to thrombin and ADP-induced aggregation noted in the pregnant rats was not obtained in either the pregnant women or in the women taking contraceptives.
The Effect of Fibrinogen Degradation Products on Plasmin Activity
Authors: Myśliwiec M , Arnesen H , Godal H. C
Published: June 2018

Purified fibrinogen degradation products Y, D or E were not found to exert antiplasmin activity as measured by the clot lysis time.

Spontaneous inactivation of plasmin was observed during incubation at 37° C. This inactivation was partly prevented by the presence of fibrinogen degradation products, as well as by other proteins.
Decreased Fibrinolysis in Behçet’s Disease
Authors: Chajek Tova , Aronowski Eta , Izak G
Published: June 2018

The coagulation and fibrinolytic systems have been investigated in nine patients suffering from Behçet’s disease. Six of these had thrombophlebitis.

The results of these studies revealed markedly elevated fibrinogen concentration and increased factor VIII activity as well as a pronounced decrease in the spontaneous fibrinolytic activity. This latter finding may have resulted from the presence of a potent antiplasmin activity and that of an inhibitor of the plasminogen activator detected in these patients’ sera.

It is suggested that decreased fibrinolysis aggravates the thrombotic episodes frequently encountered in Behçet’s disease; accordingly treatment with fibrinolytic agents was found to offer marked benefits.
The Specificity of Antibodies to Factor VIII Produced in the Rabbit after Immunization with Human Cryoprecipitate
Authors: Kernoff P. B. A , Rizza C. R
Published: June 2018

The relationship between the activity-neutralizing and precipitating activities of rabbit antibody to human factor VIII was studied by measuring the changes in levels of the two activities in two sensitized rabbits after stimulation with cryoprecipitates prepared from the plasmas of normal subjects, haemophiliacs and patients with von Wil- lebrand’s disease. Injection of cryoprecipitates prepared from plasmas with a detectable level of factor VIII clotting activity was followed by a marked rise in the level of activity-neutralizing antibody, whereas there was no rise or a continued fall in level after injection of cryoprecipitates prepared from haemophilic plasmas without detectable factor VIII activity. The level of precipitating antibody rose markedly after injection of normal and haemophilic cryoprecipitates, but little or not at all after cryoprecipitates prepared from the plasma of the patients with von Willebrand’s disease. It is suggested that the specific antigenic sites associated with factor VIII clotting activity were not present in cryoprecipitates prepared from haemophilic plasmas without detectable factor VIII activity, and also that antibodies of two different specificities could be detected.
Retention of Platelets by Glass Beads Variation with the Age of the Individual
Authors: Bucher U , Robert Y , Riedwyl H
Published: June 2018

Platelet function has been evaluated by Hellem’s original method in carefully screened normal persons of various ages. Factors which could possibly influence platelet behaviour, such as drugs, smoking, hypercholesteremia, prediabetes, hypertension or uremia were excluded in preliminary examinations. Only individuals in perfect health without a history of coronary heart disease, peripheral vascular disease or other thrombotic disorders were selected. Physical activity did correspond to the age. Variation in results possibly due to technical factors were eliminated by using strictly the same method and material throughout the study and by performing the tests within a relatively short period of time. From an original group of 109 normal persons, 70 individuals between the ages of 10 and 90, who corresponded to the described standards were chosen for further trials. They were divided into 7 age groups, each including 10 individuals within a decade (the last group ranging from 70 to 90 years). Retention of platelets in a column of glass beads was measured by Hellem5s method. The results, expressed as per cent retention and represented graphically, form a parabolic curve with its minimum at the age of 35 (mean ± 2 SD = 50 i 22%). The mathematical function of the curve can be expressed in a formula as second degree polynomial. It is shown by analysis of variance that age is the only factor on which the slope of the curve depends. Physiological or pathological implications of these findings are not known. The results, however, show that age must be taken into account when differences of platelet behaviour are discussed.
Abortion in Cases of Zika Virus Congenital Infection
Authors: Mota Vivian Maria Ribeiro , Cavalcanti Luciano Pamplona de Góes , Delfino Alanna dos Santos , Lopes Thayse Elaine Costa Figueiredo , Pessoa André Luiz Santos , Ribeiro Erlane Marques
Published: June 2018

The emergency in international public health caused by the Zika virus gave rise to the discussion about abortion in cases of congenital Zika virus syndrome (CZS). Therefore, we propose to carry out a bibliographic review on abortion in these cases. Five databases were searched using the following terms: abortion, miscarriage, and zika, with the interposition of the Boolean operator “AND.” In the selected literature, we found references to the lack of information concerning the risks and severity of CZS, to the great psychological distress suffered by pregnant women, and to the risk of unsafe abortions as a justification for abortion in cases of CZS. However, it is necessary to have available tests that could diagnose, in the first trimester of pregnancy, that the fetus has been affected by the virus, and that it may have important limitations, in order to subsidize the qualified discussion about abortion in these cases.
The Action of Vipera aspis Venom on Blood Clotting Factors and Platelets
Authors: Boffa M. C , Josso F , Boffa G. A
Published: June 2018

On human plasma, the venom of Vipera aspis has both an immediate procoagulant effect and a late fibrinogenolytic and fibrinolytic activity. This procoagulant effect is shown in presence of calcium ions and is observed even in the absence of phospholipids. Factors V and X are the main substrates necessary for this action.

The venom progressively hydrolyses fibrinogen impairing clot formation. It has a fibrinolytic action in the absence of plasminogen.

On platelets, the venom of Vipera aspis inhibits the aggregation induced by ADP, collagen or small amounts of adrenalin. Platelet phospholipids are hydrolysed by the venom and the hydrolysis products are hemolytic. With venom, platelets lose part of their procoagulant properties. The clot formation of PRP is impaired in the presence of the venom as seen on thromboelastogram.
Studies on the Role of Fibrinolysis and Fibrinogen Degradation Products (FDP) in Analgesic Action of Morphine
Authors: Buczko Włodzimierz , Wiśniewski Konstanty
Published: June 2018

The role of fibrinolysis and FDP in the analgesic action of morphine in mice and rats was studied. It was shown that during activation of blood fibrinolysis, both the accumulation of morphine in the brain tissue of rats and the clinical effect of this drug were increased. Similar results were observed after morphine given simultaneously with FDP obtained in vitro. The data from the analysis of FDP carried out on Sephadex G-25 Fine columns suggest that only FDP of molecular weight of about 10,000 potentiate the action of morphine; smaller peptides decreased the action of this drug.
The Effect of Venous Occlusion on the Sequestration of Blood Platelets
Authors: Hladovec J , Koleilat Z , Přerovský I
Published: June 2018

The venous occlusion of all four legs in rats caused a highly significant decrease of platelet counts in venous blood especially after the correction for an opposite change in haematocrit. A very pronounced decrease in platelets was observed in human volunteers after a venostasis in one arm in the blood drawn from the occluded limb just before the release of occlusion. Similar decreases were found after a venostasis of both legs in postocclusion blood samples. The decrease in blood platelets results from temporary sequestration in the occluded limbs. The decreases of platelets after a 10 min occlusion of both legs are more pronounced in patients with post thrombotic states.
Effect of Detergents on Platelet Electrophoresis and Aggregation, and the Possible Relation of Plasma Surface Activity to Thrombosis
Authors: Hampton J. P , Nicholls D. G
Published: June 2018

A variety of anionic, cationic, and non-ionic detergent compounds has been shown to increase the sensitivity of the electrophoretic response of human platelets to adenosine diphosphate. The effect of such compounds on normal platelets is very similar to that of plasma from patients with arterial disease, and it is suggested that there may be an abnormality in the surface-active properties of the plasma from such patients. One detergent, cetyl pyridinium chloride, was found not to induce any change in platelet electrophoretic behaviour, but to protect platelets from other detergents. It was also shown to be a powerful inhibitor of platelet aggregation.
Evidence for Two Separate Effects of Adenosine Diphosphate on Human Platelets
Authors: Hampton J. R , Nicholls D. G , Mitchell J. R. A
Published: June 2018

Further studies are reported on the mechanism by which platelets from patients with arterial disease develop abnormal electrophoretic sensitivity to adenosine diphosphate (ADP). Plasma from such patients can only induce abnormal platelet sensitivity to ADP if ADP is itself present. There are two separate effects of ADP on human platelets, one which allows platelets to interact with abnormal plasma, and another which is reflected by changes in platelet electrophoretic mobility ; the former is inhibited by cyanide, and the latter is not.

The effects of lecithin on normal platelets are similar to those of abnormal plasma, but if lecithin is incubated with plasma before addition to platelets its effect is lost.
Carbohydrate Structure in Factor VIII
Authors: Austen D. E. G , Bidwell Ethel
Published: June 2018

The work described in this paper provides new evidence that factor VIII is a glycoprotein, based upon a study of inactivation of the factor using extracts of Trichomonas foetus. Such extracts contain powerful enzymes which, it is shown, will destroy factor VIII activity. Furthermore, this destruction can be inhibited by glycoproteins or by certain sugars and when these reactions are examined it is possible to show that the action of T. foetus extracts upon factor VIII is one of glycolysis and hence that factor VIII is a glycoprotein. No similarity is found between the carbohydrate structure in factor VIII and that in blood group substances. In addition, no parallel has yet been found between the reaction of factor VIII with T. foetus extracts and the reaction of factor VIII with its antibody.
Requirements for Aggregation of Washed Human Platelets Suspended in Buffered Salt Solutions
Authors: Harbury Christina B , Hershgold J. Edward , Schrier Stanley L
Published: June 2018

With the use of washed human platelets suspended in a buffered salt solution, we have studied the factors capable of acting directly at the platelet plasma membrane to produce aggregation as opposed to those which produce the platelet release reaction and secondary aggregation. Platelet aggregation was measured in an aggregometer and the release reaction followed by assays of the release products.

Ca and fibrinogen will not independently induce aggregation in washed human platelets suspended in a buffered salt solution. However, in their absence ADP-, 5HT-and epinephrine-mediated aggregation will not proceed. Of particular interest was the finding that in the presence of Ca, threshold doses of thrombin will produce aggregation earlier if μg amounts of fibrinogen are added. Ca and fibrinogen therefore appear to be absolutely required for aggregation, whether the aggregation is produced by the addition or by the release of required components.

If either ADP, 5HT or epinephrine is added singly to buffer-suspended platelets in the presence of Ca and fibrinogen, 10–20% aggregation is observed. The combination of either ADP-5HT, ADP-epinephrine or 5HT-epinephrine produces 60–70% aggregation. The addition of ADP, 5HT and epinephrine together produces 80–90% aggregation.

No release reaction is produced by the addition of ADP or 5HT alone or in combination. A new finding in this study therefore is that 5HT and ADP can act directly at the platelet plasma membrane to produce extensive aggregation in the absence of any release reaction.

Epinephrine does produce a small release reaction, and may therefore produce its enhancement of aggregation either by acting directly at the platelet plasma membrane or by the release of something other than Ca, fibrinogen, ADP, 5HT, or epinephrine.

In this study using washed human platelets suspended in a buffered salt solution, no evidence was found for the requirement of a plasma protein other than fibrinogen in platelet aggregation.
Aggregation in Vitro of Immature Thrombocytes from Early Chick Embryos
Authors: Greenberg Judith H
Published: June 2018

Mammalian platelets and nonmammalian thrombocytes, although they perform a similar function, differ in morphology and in their response to thrombogenic agents. The present experiments extend the comparison between the two cell types to include the immature form of thrombocytes found in early chick embryos. Agents known to induce, or to inhibit, aggregation of platelets were tested for their effect on thrombocytes which were isolated from chick embryos of five days incubation age and which had been suspended in a tris-buffered saline solution containing EDTA. The degree of aggregation of thrombocytes was determined by phase microscopy after treatment with thrombin, trypsin, adenosine 5′-diphosphate (ADP), calcium chloride, or the sulfhydryl inhibitor N-ethylmaleimide. Approximately 450 trials were performed using 102 samples of blood, each sample being obtained by the pooling of the blood of five to six dozen embryos. The results demonstrate that thrombin and trypsin, in the presence of calcium ions, induce significant aggregation compared to that of untreated controls. Thrombin, in the absence of calcium ions, is ineffective in inducing aggregation, as is calcium chloride alone, or ADP in the presence or absence of calcium ions. Pretreatment of the thrombocytes with N-ethylmaleimide inhibited aggregation by thrombin in the presence of calcium chloride. It may be concluded that embryonic thrombocytes resemble platelets in their response to all the aggregating agents tested, with the exception of ADP, but resemble the thrombocytes of adult chickens in their failure to respond to ADP.
Progress in the Control of Oral Anticoagulation
Authors: Loeliger E. A
Published: June 2018

It should be realized that the quality of oral anticoagulation depends on thorough pharmacological knowledge of coumarin congeners, skilled clinical supervision of the patient and well-standardized laboratory control of patients’ blood. Results of the laboratory control should no longer be expressed in terms of conventional prolongation ratios or percentages only. Exact data as to laboratory standardization with reference plasmas and the results of translation into terms of reference thromboplastins have to be given.
The Shape of Blood Platelets
Authors: Murphy Martin J.
Published: June 2018

The three dimensional structure of human blood platelets has been investigated using two different methods of tissue preparation. It has been demonstrated that freeze-drying preserves platelet structure to a greater degree than other methods which employ air drying.

When platelets are prepared by conventional techniques their dendritic projections are uniformly found to be flattened and in contact with the substrate when viewed by scanning electron microscopy. When lyophilisation is used some of these fine cytoplasmic protuberances are found to be freely directed away from the substrate and may in fact elevate the entire platelet body or chromomere. The possible implications of this new observation are discussed in terms of platelet ultrastructure and their role in hemostasis.
Preparation of Modified Bovine Factor VIII with Enhanced Biological Activity Using Insoluble-trypsin Columns
Authors: Vogel Christine N. , Parfitt Henry E. , Kingdon Henry S. , Lundblad Roger L.
Published: June 2018

Crude bovine Factor VIII preparations have been modified by passage over a column of trypsin-agarose. Factor VIII prepared without an early adsorption step utilizing either barium sulfate or aluminum hydroxide gel generated significant Factor Xa activity by passage over such a column and was unsuitable for further characterization. Factor VIII prepared using adsorption with barium sulfate contained no Factor Xa activity after passage over trypsin-agarose. This trypsin-modified material showed a decreased molecular size as judged by behavior on gel filtration and an increased rate of reaction with bovine Factor IXa.
Potentiation of the Anti-factor VIII Effect of Thrombin in Plasma by the Plasminolytic Derivatives of Fibrinogen and Fibrin
Authors: Chandra S , Triantaphyllopoulos D. C
Published: June 2018

The activity of factor VIII in mixtures of native plasma or blood with fibrinogen derivatives at concentrations high enough to inhibit prothrombin consumption, is greatly reduced. On the other hand the activity of factor VIII was found normal in similar mixtures of adsorbed native plasma with fibrinogen derivatives, where no generation of thrombin could have taken place. The fibrinogen derivatives increased significantly the inactivating effect of low concentrations of thrombin on the activity of factor VIII of mixtures of adsorbed oxalated plasma with the derivatives. The same inactivating effect was exerted by fibrinogen derivatives heated at 60° C for 15 minutes and by plasmin lysed fibrin. In contradistinction addition of intact fibrinogen or fibrinogen derivatives to heat-defibrinated plasma protected factor VIII from inactivation by thrombin. When both, intact fibrinogen and its derivatives, were added simultaneously at the same concentrations at which they were added singly, the protective effect was intermediate between that exerted by intact fibrinogen and fibrinogen derivatives alone. Under these conditions the fibrinogen derivatives appeared as if they potentiated the inactivating effect of thrombin. Probably by inhibiting the formation of structural fibrin they increased the amount of thrombin, which remained unadsorbed and free to inactivate factor VIII.
Detection of Carriers of Haemophilia
Authors: Ekert Henry , Helliger Holger , Muntz Robert H.
Published: June 2018

Protein with antihaemophilic factor antigenicity (AHF-like protein) and the biological activity of antihaemophilic factor (AHF activity) was measured in 13 obligatory and 21 suspected carriers of haemophilia and 20 normals. The mean level of AHF-like protein was significantly higher in the obligatory and suspected carriers but there was a wide range of values. The ratio of AHF activity to AHF-like protein was significantly lowered. In 31 of 34 cases a diagnosis of the carrier status could be made by the use of this ratio. In 18 the AHF activity was within the normal range and in 15 of these the ratio could be used to diagnose the carrier status. The ratio was not diagnostic in 3 obligatory carriers. Estimation of the ratio of AHF activity to AHF-like protein is a valuable adjunct to genetic counselling in haemophilia.
Characterization of Clotting Factors Associated with Blood Platelets after Gel Filtration
Authors: Tangen Oddvar , Lestrup Eva B. , Berman Herbert J.
Published: June 2018

Aggregation of human and rabbit gel filtered platelets (GFP) has been studied in presence of Ca2+, activated factor X (Xa) and different plasma preparations. It was found that factor Xa by itself is not a platelet aggregating agent. However, the platelets aggregated immediately when platelet poor plasma (PPP) was added to a mixture of GFP, Ca2+ and factor Xa. Aggregation also occurred immediately when factor V-deficient plasma was substituted for PPP, but not when factor II-deficient plasma was used. In the absence of factor Xa, aggregation occurred on addition of factor V- or VIII-deficient plasma, but only after some delay. The platelet aggregation experiments and experiments with centrifugations and resuspensions of the platelets, clotting experiments, and gel filtration of platelet free plasma (PEP) led to the following conclusions : Factors II and X are totally removed from the platelets by gel filtration, factor V is closely associated with the platelet surface, and part of the factor VIII-activity in the plasma is eluted together with the GFP without being associated with the platelets. This factor VIII-activity belonged to an extremely large molecule or molecular complex with a Mw in the order of 2 - 5 · 107.
The Effect of Barbituric Acid Derivatives on Platelet Function in Vitro and in Vivo
Authors: Joist J. Heinz , Cazenave Jean-Pierre , Mustard J. Fraser
Published: June 2018

Sodium pentobarbital (SPB) and three other barbituric acid derivatives were found to inhibit platelet function in vitro. SPB had no effect on the primary response to ADP of platelets in platelet-rich plasma (PRP) or washed platelets but inhibited secondary aggregation induced by ADP in human PRP. The drug inhibited both phases of aggregation induced by epinephrine. SPB suppressed aggregation and the release reaction induced by collagen or low concentrations of thrombin, and platelet adherence to collagen-coated glass tubes. The inhibition by SPB of platelet aggregation was readily reversible and isotopically labeled SPB did not become firmly bound to platelets. No inhibitory effect on platelet aggregation induced by ADP, collagen, or thrombin could be detected in PRP obtained from rabbits after induction of SPB-anesthesia.
Formation and Embolization of Thrombi after Electrical Stimulation
Authors: Spilker B. A , van Balken H
Published: June 2018

Characteristics of thrombi produced upon electrical stimulation of mesentery and brain vessels were studied in five species. Parameters for measuring drug effects were also evaluated to determine which were sensitive to platelet aggregation inhibitors. The current required to cause vasoconstriction in 50% of the rat mesentery arteries stimulated was increased by vasodilators, but not by inhibitors of platelet aggregation. The threshold of current necessary to cause thrombus formation was increased by Imipramine in both acute and chronic experiments and by aspirin and papaverine in chronic experiments. Since these were the only agents tested which inhibit platelet aggregation there appears to be a relationship between this property and the threshold of current necessary to cause thrombus formation. This parameter may possibly be used to differentiate between platelet aggregation inhibitors and streptokinase-like or heparin-like agents. Changes in mean embolization time under present conditions were not related to activity in inhibiting platelet aggregation.
A 3.5-Second Phenomenon in Haemostasis
Authors: Thilo D , Böhm E
Published: June 2018

Experiments with injury of the abdominal rat skin were carried out to examine the haemostatic system mechanism in vivo after zero to 30 seconds bleeding time. In the bleeding area only a few platelet aggregates could be found with no primary platelet thrombus. After 3.5 second bleeding time the first fibrin strands have been observed at the site of injury. The hypothesis is put forward that there is a very fast reacting haemostatic mechanism which results in the fibrin formation already at 3.5 seconds.