bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood Fibrinolysis in Liver Disease
Authors: Brakman Pieter , Mohler Emile R. , Astrup Tage
Published: April 2009

Selected parameters of blood coagulation and fibrinolysis were determined in 25 men with severe alcoholic liver disease, in 10 men with mild disease, and in 10 patients with coincidental disease or liver disease not etiologically related to consumption of alcohol. Large variations in individual data, including unusually low and high values, were observed in several parameters. Usually, coagulation was prolonged in severe liver cirrhosis and frequently in mild cirrhosis. Plasminogen was decreased in severe, but not in mild disease. Euglobulin fibrinolytic activity, determined on bovine, plasminogen-rich fibrin plates, was decreased in severe as well as in mild disease. In 12 patients with severe disease, screened for inhibitors, slightly decreased inhibition of urokinase, tissue activator, and plasmin was observed. A carbontetrachloride poisoned patient showed defective coagulation and low plasminogen concentration, though fibrinogen was elevated; his euglobulin fibrinolytic activity was normal, but inhibition of tissue activator-induced fibrinolysis was markedly increased. Four hepatoma patients showed a marked increase in inhibition of tissue activator-induced fibrinolysis. The wide variety of changes indicates that the role of the liver in haemostatic homeostasis is a complex one. Our data suggest a correlation between inhibition of plasminogen activation and development of thromboembolic disease.
Artificial Thrombus Formation and Blood Viscosity in Haemophilia A and Christmas Disease
Authors: Dintenfass L. , Forbes C.D.
Published: April 2009

Dynamic coagulation-thrombus formation studies and evaluation of the aggregation of red cells, plasma viscosity and blood viscosity were carried out on 22 patients with haemophilia A and 6 patients with Christmas disease. Significant differences are found in the formation and viscosity of artificial red/white and white thrombi between patients with haemophilia A and with Christmas disease.A treatment by plasma infusion or by cryoprecipitate leads to an elevation of plasma viscosity and viscosity of artificial thrombi, and to a decrease of the thrombus formation time. Both types of treatment can be considered equivalent from the rheological point of view. Highly significant correlations are established between the fibrinogen levels and all blood viscosity factors. In particular, fibrinogen level and viscosity of artificial thrombi (p < 0.001), fibrinogen and plasma viscosity (p < 0.001), and fibrinogen and aggregation of red cells (p < 0.01).
Hepatic and Splenic Platelet Sequestration during Deep Hypothermia in the Dog
Authors: Pina-Cabral J.M. , Amaral Izolett , Pinto Macedo , Guerra E. Paz L.H.
Published: April 2009

After injection of 51Cr-labelled platelets, dogs were cooled down to 20 °C and rewarmed to 36 °C. Radioactivity increased over the hepatic area during cooling, to decrease again during rewarming. It increased continuously during the observation period over the splenic area. The inverse symmetry of the curves representing the radioactivity measured over the liver and in the peripheral blood together with the fact that splenectomy did not alter significantly the thrombocytopenia observed, strongly suggests that in the dog the liver is the main organ responsible for platelet sequestration during hypothermia.
Circulating Anticoagulant in Disseminated Lupus Erythematosus
Authors: Veltkamp J.J. , Kerkhoven P. , Loeliger E.A.
Published: April 2009

Seven patients, four of whom have proven DLE, are described with a circulating anticoagulant displaying antiphospholipid activity. The anticoagulant effect is decreased when the patient sample is added in a more diluted form and can be overwhelmed by a phospholipid preparation of high potency. This explains for the absence of hemorrhagic symptoms in these patients because a vast excess of platelet phospholipid is liberated during platelet plug formation. Furthermore the inhibitor does not protect against thrombosis.
Effects of Some Polysaccharide Sulfates and Some Phosphates on Neutral Proteases and Plasminogen Activators
Authors: Ray Gauranga , Astrup Tage
Published: April 2009

Several polysaccharide sulfates (heparin, dextran sulfate, chitin disulfate, cellulose sulfate) and some phosphates (α-tocopherol phosphate, polyphloretin phosphate, hexametaphosphate) were investigated for their direct effects on fibrinolytic agents (neutral proteases and plasminogen activators). α-Tocopherol phosphate and polyphloretin phosphate were strong inhibitors. The remainder of the compounds had mostly weak inhibitory or enhancing effects varying from compound to compound and with the type of fibrinolytic agent. Some (heparin, chitin disulfate, hexametaphosphate) had little or no influence at the concentrations used.
Evidence for C1 on Human Platelets
Authors: Wautier J.L. , Tobelem G.M. , Peltier A.P. , Caen J.P.
Published: April 2009

Evidence for the presence of the first component of complement (C1) on human gel-filtered and washed platelets is presented. The possible role of C1 in human platelet aggregation induced by aggregated immunoglobulins or immune complexes is discussed.
Discrepant Platelet Kinetic Data Obtained in Rats Using the Platelet Labels 51Cr and DFP 3H
Authors: Ginsburg A.D. , Aster R.H.
Published: April 2009

Platelet kinetics in a single species, the rat, have been studied utilizing two different labels – 51Cr, and DFP 3H. Disappearance of isotope was primarily linear with time with the 51Cr tag, but exponential with DFP 3H. This difference could not be ascribed to a toxic effect of the DFP or its carrier, propylene glycol, or to nonuniform uptake of the labels by platelets of differing mean age. It is suggested, therefore, that DFP is preferentially lost from the platelet either by elution or by release of a platelet component to which this isotope binds. The possibility is discussed that such loss is concerned with platelet function, perhaps in support of endothelial integrity.
Effect of Contact Factor (Factor XII + Factor XI) on Aggregation of Platelets
Authors: Aznar J. , Mayans J. , Aznar J.A.
Published: April 2009

Inhibition of platelet aggregation by contact factor eluate (CFE) is demonstrated. A similar inhibition of platelet aggregation is found following incubation of ellagic acid with native platelet rich plasma. Inhibition of platelet aggregation by CFE or ellagic acid was not found when PRP from a patient with Hageman’ disease was used. The electrophoretic mobility of platelets was increased by the action of CFE. The possible role of the contact factor as a regulator of the platelet plug in the early stages of haemostasis is discussed.
Some Effects of a Microcrystalline Collagen Preparation on Blood
Authors: Mason R.G. , Read M.S.
Published: April 2009

Bovine microcrystalline collagen preparations are reported to be effective topical hemostatic agents. These collagen preparations shorten the clotting time of native blood. Platelets adhere to the microcrystalline collagen and appear to undergo the release reaction producing aggregation of nearby platelets. The hemostatic action of these collagen preparations appears to be exerted through their effects on platelets rather than through direct effects on soluble components of the intrinsic blood coagulation system.
Acquired Inhibitors in Nonhemophilic Patients
Authors: Lechner K.
Published: April 2009

The occurence, the biological, biochemical and immunological properties of spontaneous inactivating inhibitors (directed against factors VIII, V or XIII) and of interfering inhibitors (inhibiting prothrombin activation) are reviewed. The clinical implications and therapy of these inhibitors are discussed with special reference to the management of patients with spontaneous factor VIII inhibitors.
Inhibition of Fibrinolysis by the Human Vascular Wall Related to the Presence of Smooth Muscle Cells
Authors: Hegt Vincent Noordhoek , Brakman Pieter
Published: April 2009

The fibrin slide sandwich technique is a histochemical method for the detection and localization of inhibition of fibrinolysis in tissues. By this technique it was demonstrated that plasmin inhibition is present in the human vascular wall. The great diversity in the pattern and the capacity for inhibition among different parts of the vascular system appeared to be in close association with the localization and number of smooth muscle cells present in this system. The postulated relationship between fibrinolytic inhibition and smooth muscle cells was strongly supported by the demonstration of a similar inhibition of fibrinolysis in other human tissues containing a high number of smooth muscle cells.
Platelet Function Tests in Uraemia and Under Acetylsalicylic Acid Administration
Authors: Schöndorf T.H. , Hey D.
Published: April 2009

Procollagen-induced platelet aggregation, platelet retention (Hellem II), and platelet factor 3 availability (PF-3) were determinded in a group of healthy volunteers, acetylsalicylic acid (ASA) treated patients and in uraemic patients. ASA ingestion did not influence platelet retention and PF-3 availability. Uraemic patients had a pronounced decrease in platelet aggregation and retention and PF-3 availability revealed inconsistent alterations. The relevance of the tests and the benefit of an ASA treatment for prophylaxis of thrombosis in Cimino fistulae are discussed.
Different Properties of Factor VIII in Von Willebrand’s Disease with Respect to Recovery in Cryoprecipitate
Authors: Stibbe J. , van der Plas P.M. , Hemker H.C.
Published: April 2009

The recovery of factor VIII-activity in cryoprecipitate prepared from plasma from six patients with von Willebrand’s disease was low as compared to the recovery from normal and hemophilia-A plasma. The possible cause is briefly discussed.
Pre- and Post-Operative Studies of Fibrinolysis and Prothrombin in Cyanotic Congenital Heart Disease
Authors: Ekert H. , Sheers M.
Published: April 2009

Multiple components of the fibrinolytic mechanism (plasminogen, plasmin, antiplasmin, fibrinogen, fibrin degradation products) and factor II (prothrombin) levels were studied in 40 children with cyanotic congenital heart disease (CCHD) prior to corrective surgery. Seven of these were also studied post-operatívely. A further 17 children were studied after corrective surgery only. Pre-operatively, increased fibrinolysis could be demonstrated in only 7.5–12% of patients, and there was no correlation between the levels of fibrinolytic components and the severity of polycythemia or post-operative blood loss. There was no evidence of fibrinolysis post-operatively. Pre-operatively, low prothrombin levels were common (25 %), were correlated with the amount of post-operative blood loss and were restored to normal by corrective surgery. Hypoprothrombinaemia is one of the most significant haematological abnormalities in CCHD.
Acute Disseminated Intravascular Coagulation as the Presenting and Predominant Clinical Manifestation in a Patient with a Mucinous Adenocarcinoma
Authors: Levo Y. , Pick A.I. , Cohen I. , Atsmon A.
Published: April 2009

A patient with a fulminant clinical course of disseminated intravascular coagulation (DIC) is described. The DIC was first manifested by neurological symptoms and later dominated by hemorrhagic phenomena. Bleeding manifestations were not controlled by treatment with heparin, later supplemented with ε-amino-caproic acid and fresh blood. The patient’s condition precluded the performance of extensive diagnostic procedures. On the assumption that malignancy was the underlying disease, cyclophosphamide and hydrocortisone were administered. In spite of intensive treatment the patient died. Autopsy revealed mesenteric lymph node metastases of a mucinous adenocarcinoma, probably originating in the colon. It is emphasized that in some patients with malignant disease, acute DIC is the presenting and the predominant symptom. In such patients the hemorrhagic manifestations may not be controlled unless the underlying neoplastic disease is detected and treated.
Analysis of an Autoimmune Antibody (IgM Class) in a Case of Chronic Lymphocytic Leukaemia
Authors: Houbouyan L. , Soria J. , Soria C. , Goguel A.
Published: April 2009

A case of an acquired circulating anticoagulant occurring in a patient suffering from chronic lymphocytic leukaemia with haemolytic anaemia and autoimmune disorders has been reported. The anticoagulant was found to belong to the IgM class. Coagulation studies show that this anticoagulant inhibits the reaction between human prothrombinase and factor II.
Effect of Reserpine on 14C Serotonin Uptake by Thrombasthenic Platelets
Authors: Rendu F. , Caen J.P.
Published: April 2009

The incorporation of 14C-5HT by platelets was found to be abnormal in two groups of thrombasthenia. In the first group of patients, which have a low platelet fibrinogen content, incorporation was initially faster than in normal platelets. With the exception of one patient who was subsequently discovered to possess an antibody which inhibited ADP-induced aggregation of control platelets, the rate of incorporation of 14C-5HT in group I thrombasthenic platelets reached a maximum and then decreased. In the control platelets incorporation of 14C-5HT was continuous. In a patient of the second group of thrombasthenia, with a low ATP content, incorporation of 14C-5HT was also continuous but was at a much lower level than normal. Results obtained with reserpine suggest that this compound affects the active incorporation of 14C-5HT into platelet granules and, possibly, is associated with a prevention of 5-HT release.
Immunofluorescent Detection of Factor VIII-Related Antigen in Human Platelets and Megakaryocytes
Authors: Piovella F. , Ascari E. , Sitar G.M. , Malamani G.D. , Cattaneo G. , Magliulo E. , Storti E.
Published: April 2009

Platelets, lymphocytes, and megakaryocytes, specifically processed for the intracellular detection of antigens, were studied by indirect immunofluorescence techniques using monospecific antibodies directed against factor VIII-related antigen (F-VIII-RA). Specific staining was observed in platelets of the peripheral blood from normal individuals and from patients with haemophilia A, and in megakaryocytes and platelets of bone marrow from normal subjects. The same cells studied in patients with von Willebrand’s disease were negative. No bone marrow biopsies were performed on patients with haemophilia A. Our results indicate that F-VIII-RA is localized in megakaryocytes and platelets of normal subjects; the possible role of this F-VIII-RA in platelet function is discussed.
Sampling of Rat Blood for HemostasIs Studies
Authors: van Oosterom A.T. , Zuidervaart W. , Veltkamp J.J.
Published: April 2009

For coagulation studies on rat blood requiring consecutive samples it is best to obtain blood from the tail, under ether anesthesia, by amputation of one vertebra for each sample wanted. Higher activity levels of clotting factors in unanesthetized rats are not due to stress. The coagulation activation phenomenon is always present in capillary blood samples from unanesthetized rats and is enhanced in serial blood samples unless three vertebrae are amputated to obtain the sample. The procedure described here, applied to unanesthetized rats, could serve as a model for the testing of antithrombotic drugs.
Influence of Simultaneous Administration of Low-Dose Heparin and Acetylsalicylic Acid on Blood Coagulation and Platelet Functions
Authors: Loew D. , Vinazzer H.
Published: April 2009

In an attempt to examine the effect on hemostasis, 20 patients suffering from thrombophlebitis or from postthrombotic syndrome received 10,000 units of heparin and 1.5 g of acetylsalicylic acid (ASA) per day. The scheme of application permitted to distinguish three periods of treatment: heparin, heparin plus ASA and ASA alone. By frequent blood coagulation tests, the alterations of the clotting mechanism during each of these periods were examined. Influences on the plasmatic clotting mechanism were exclusively caused by heparin and were not altered by the addition of ASA. There was, however, a synergistic action of both drugs on the depression of platelet factor 3 availability. Platelet aggregation was enhanced by heparin but could be suppressed by the combined therapy as well as by ASA alone. The overall alterations of hemostasis and coagulation were mild. Even when both drugs were administered simultaneously, the changes were moderate and no clinical signs of hemorrhage could be detected. The purpose of this study was to examine whether a combination of both drugs can be safely applied in an attempt to increase the efficiency of preventive therapy of thromboembolism.
Derivatives of Fibrinogen and Fibrin during Defibrase Therapy
Authors: Asbeck F. , Lechler E. , Martin M. , van de Loo J.
Published: April 2009

The course of defibrination after administration of a thrombin-like snake venom protease, Defibrase®, has been studied in two patients with arterial occlusive disease. Agarose gel filtration of fresh plasma makes it possible to differentiate between high (HMWD) and low molecular weight fibrinogen and fibrin derivatives (LMWD) which arise during therapy. HMWD can be quickly and dependably detected in the column eluate by the staphylococcal clumping test. They probably consist mainly of fibrin monomer complexes during the coagulation phase, but during the fibrinolytic phase mainly of high molecular weight fibrinolytic degradation products. LMWD in the column eluates have been identified by radial immunodiffusion. By combining several different methods for the determination of fibrinogen-fibrin-related material the process of defibrination and reactive fibrinolysis may be studied in detail. The protracted activity of one injection of Defibrase can be clearly documented.
Blood Viscosity in Hyperthyroid and Hypothyroid Patients
Authors: Dintenfass L. , Forbes C.D. , McDougall I.R.
Published: April 2009

Whole blood viscosity, plasma viscosity, aggregation of red cells and internal viscosity (deformability) of erythrocytes were investigated in twelve hyperthyroid patients and six hypothyroid patients. Significant differences were found in the calculated relative blood viscosity and also in the deformability of red cells in these two groups. It is suggested that the increase in relative blood viscosity and in the deformability of the red cell may, in part, account for the circulatory disturbance in hypothyroidism.
Adenine Nucleotide Metabolism during the Aggregation of Human Platelets by Bovine Factor VIII
Authors: Østvold Anne-Carine , Lindberg May Elisabeth , Solum Nils Olav , Holmsen Holm
Published: April 2009

Human platelets, prelabelled with [3H]-adenine in vitro, were aggregated biphasically by bovine fibrinogen/factor VIII, and the amounts and specific radioactivity of ADP and ATP as well as the radioactivity of ATP, ADP, AMP, IMP and hypoxanthine + inosine were determined intracellularly and extracellularly. During the second phase of aggregation, ATP and ADP were released (50 % of total) with a specific radioactivity 15–20 times lower than that of the ATP and ADP retained in the cells. The specific radioactivity of the ATP and ADP in the cells increased during release. Radioactive ATP was converted to radioactive hypoxanthine during release. These findings correlated well with those obtained with collagen, and indicate that bovine factor VIII induces the platelet release reaction whereby the storage (non-metabolic) pool of ATP and ADP is released while the metabolic pool is retained.
Influence of Intravenously Administered Acetylsalicylic Acid on Platelet Functions
Authors: Vinazzer H. , Pütter J. , Loew D.
Published: April 2009

The influence of intravenously administered acetylsalicylic acid (ASA) on the kinetics of platelet function was examined in 10 patients. Simultaneously, assays of salicylate in plasma were performed. A significant inhibition of platelet aggregation as well as PF 3 and PF 4 availabilities could be demonstrated 2 min after injection. A decrease of platelet adhesion was significant after 15 min. The inhibition of platelet functions was still present after 24 h and was partially demonstrable after 72 h. The concentration of salicylate in plasma 2 min after injection of ASA was only about two thirds of the level calculated from mere distribution in circulation. After 1 h, half of the initial salicylate had disappeared from plasma. No salicylate could be found after 24 hours. ASA also depressed platelet functions when added to platelet-rich plasma in vitro in a concentration of 100 μg/ml. Inhibition of platelet aggregation and of PF 4 availability were dependent on the time of incubation. Their onset was much slower in vitro than in vivo. No inhibition of the PF 3 availability could be found in vitro. The inhibition of platelet functions by ASA is demonstrable almost immediately after injection while the duration of this inhibition is considerably longer than the elimination time of salicylate from plasma. This allows the conclusion that a direct intravascular reaction between ASA and platelets occurs and that the inhibition of platelet functions is irreversible.
Electroencephalography in Haemophilia and Christmas Disease
Authors: Forbes C.D. , Renfrew S.
Published: April 2009

Electroencephalography has been performed in a series of patients with haemophilia and Christmas disease because of the suggestion by other authors of a high incidence of abnormality. In an adult population of haemophiliacs no difference was found in the incidence of abnormalities compared with the general hospital population.
Fibrinogenolytic Substance (Hementerin) of Brazilian Blood-Sucking Leeches (Haementeria lutzi Pinto 1920)
Authors: Kelen Eva M.A. , Rosenfeld G.
Published: April 2009

The fibrinogenolytic activity of the salivary gland extract from the Brazilian blood-sucking leech Haementeria lutzi Pinto 1920 is characterized. The substance, named here hementerin, is stable and active at very low protein concentration, does not exhibit direct proteolytic activity on casein, fibrinogen, or fibrin, and is able to activate the human plasma fibrinolytic system in the presence of a serum cofactor and/or calcium. This indirect activation mechanism distinguishes hementerin from hirudin and shows a similarity with streptokinase. The effect on blood coagulation tests is reported.
Changes in Coagulation Factors and Platelet Function in Response to Progestational Agents
Authors: McGrath K.M. , Castaldi P.A.
Published: April 2009

Levels of coagulation factors I, II, V, VII-X, VIII, IX, X, plasminogen and antithrombin III, were determined at midcycle in 17 test subjects using oral contraceptive agents, and in 10 control subjects. Immunoassay of factor II and antithrombin III was also carried out, and platelet aggregation quantitatively assessed. Significant increases were found in the activity of factors II, V, VII-X, X and plasminogen, but factor II antigen levels did not change. Platelet aggregation with collagen was significantly enhanced. No change occurred in antithrombin III activity or antigen levels.
Serotonin Uptake and Glycolytic Activity of Human Platelets after Prolonged Incubation with Glucose-Poor Plasma
Authors: Hardeman M.R. , Prins H.K.
Published: April 2009

It is confirmed that metabolic energy is a prerequisite for the uptake of serotonin by human blood platelets. Starvation (i.e. incubation at 25 °C of platelets resuspended in glucose-poor autologous plasma) generally stops glucose consumption, lactate formation as well as serotonin uptake within 2 h. The addition of glucose restores lactate formation immediately and, independent of total starvation time, to normal or even higher levels. The active uptake of serotonin, however, can be restored only partly after prolonged incubation with glucose, to an extent which seems to be dependent of the preceding starvation time. The results are compatible with the hypothesis that besides an active carbohydrate metabolism another factor, presumably the integrity of the platelet membrane, is obligatory for the active transport of serotonin.
Photometric Assay of Antithrombin III with a Chromogenic Substrate
Authors: Vinazzer H.
Published: April 2009

A simple assay procedure for antithrombin III is described. The synthetic product benzoyl-Phe-Val-Arg-p-nitroanilide (S-2160) is used as substrate. By thrombin p-nitroaniline is split from the tripeptide molecule. The yellowish color of this split product can be measured in a photometer. Inactivation of thrombin by antithrombin III results in inhibition of this reaction. The percentage of thrombin inhibited is in direct relation to the activity of antithrombin III. Various modifications were tested to optimate the method. Comparable results were obtained between the coagulation method of HEnsen and LOeliger and the photometric method.
Fibrin Plate Method with Reagents Purified by Affinity Chromatography and its Use for Determination of Fibrinolytic and Other Proteolytic Activity in Saliva, Bile and Plasma
Authors: Norén I. , Ramström G. , Wallén P.
Published: April 2009

A modification of the fibrin plate method is presented. Plasminogen-free human fibrinogen and plasminogen purified by affinity chromatography have been used. Fibrin plates without and with a constant amount of plasminogen and with agarose as stabilizing medium were used for the estimation of plasmin and plasminogen activator activity. Activator activity could be demonstrated in sterile bile and saliva. When plasmin activity was present, estimations of plasminogen activator were approximate. The method is sensitive, small volumes of reagents and samples are needed. The error of the method is comparatively low and the reproducibility is good.
Physical, Chemical and Immunological Studies on Bovine Factor VIII
Authors: Casillas G. , Simonetti C. , Vasquez C. , Pavlovsky A.
Published: April 2009

Highly purified bovine factor VIII prepared according to our technique and having a specific activity of 500 U/mg protein has been studied. The chemical analysis of the preparation revealed it to be composed of amino acids, lipids (8–10%) and carbohydrates (7 %). The lipid moiety can be removed by chromatography. Different mechanisms of inactivation of bovine factor VIII and the possible molecular changes induced by the inactivating agents were studied. EDTA and EGTA provoke a weakening of the bonds linking the structural elements of the molecule, which allows for the separation of two different components of the molecule by gel filtration. Upon treatment with thrombin, the carbohydrate content of bovine factor VIII decreases without any apparent degradation of the protein moiety of the molecule. The fact that precipitating and neutralizing antisera against factor VIII were obtained, shows that the molecules modified by EDTA and thrombin still have the antigenic properties of factor VIII. The inhibitor developed by hemophiliacs transfused with human factor VIII is bound to bovine factor VIII, forming a complex which is stable upon agarose gel filtration. Immunological studies of the purified complex reveal that it is composed of bovine factor VIII and human γ-globulin. Bovine factor VIII in the complex retains some antigenic determinants which bind rabbit anti-serum against bovine factor VIII, as shown by neutralization of the antiserum and by precipitation studies.
A Comparative Study of the Effect of Oral Contraceptives and Cigarette Smoking on Platelet Adhesiveness
Authors: Strolin-Benedetti M. , Gutty D. , Strolin P.
Published: April 2009

The aim of this work was to discover to what extent cigarette smoking and oral contraceptives, either separately or in association, are responsible for platelet adhesiveness changes in humans. Platelet adhesiveness has been measured in 77 subjects, smokers and nonsmokers. 47 of these subjects were women both using and not using oral contraceptives. Cigarette smoking significantly increases platelet adhesiveness both in men and women. On the contrary, if no distinction is made in the smoking habits of female volunteers and they are only divided into two groups according to the use or nonuse of oral contraceptives, no significant change in platelet adhesiveness occurs following intake of oral contraceptives.
Platelet Function after the Administration of Chlorpromazine to Human Subjects
Authors: Warlow Charles , Ogston D. , Douglas A.S.
Published: April 2009

Chlorpromazine is known to inhibit platelet function in vitro. The intramuscular injection of 50 mg to human volunteers caused only minor changes in platelet function. There was a small, but significant, reduction in the platelet count, the second phase of the double-wave of adenosine diphosphate-induced aggregation and the rate of 5-hydroxytryptamine-induced aggregation. Patients on high doses of chlorpromazine had no demonstrable abnormality of platelet function. This suggests that chlorpromazine, despite its inhibitory effect on platelet function in vitro, is unlikely to interfere with either haemostasis or thrombogenesis after its administration to man.
Reduced Aggregability of Platelets in Rat Anaphylaxis
Authors: Fésüs L. , Muszbek L.
Published: April 2009

In the PRP of anaphylactic rats, ADP, collagen and thrombin induced platelet aggregation was considerably reduced. Reduced aggregability could be transferred to normal platelets by suspending them in the PPP of anaphylactic animals and the impaired aggregation of platelets from animals undergoing anaphylaxis could be restored by exchanging their plasma for that of normal controls. Ellagíc acid, a known activator of factor XII, produced similar alterations as obtained in anaphylactic shock. It is suggested that the inhibition of platelet aggregation is due to the anaphylactic activation of factor XII and this mechanism may be of importance in rat anaphylaxis.
Further Studies of the Interaction between Ristocetin and Fibrinogen
Authors: Goh A.T.W. , Firkin B.G.
Published: April 2009

Fibrinogen (FG) precipitation by ristocetin is enhanced by lowering the temperature to 4 °C. The precipitate has similar properties to an acquired cryofibrinogen being resolubilised on rewarming to 37 °C, and the process of precipitation and resolubilisation can be repeated indefinitely by lowering and raising the temperature. Other plasma proteins are also precipitated by ristocetin, but to a lesser degree than FG. This property appears to have no relation to ristocetin’s ability to aggregate platelets in the presence of von Willebrand’s factor, since platelet aggregation by ristocetin is inhibited by lowering the temperature.
Haemostasis in the Microvasculature of the Rabbit Mesentery, Effects of some Pharmacological Agents of Current Interest in Haemostasis and Thrombosis
Authors: Bergqvist D. , Arfors Karl-E.
Published: April 2009

A study has been performed to evaluate the effect on haemostatic plug formation in the rabbit mesenteric microcirculation of some principally different pharmacological substances of current interest in thrombosis research. It seems as if agents which have a potential value in the prophylaxis of venous thrombosis also modify haemostasis in our experimental model.
Adhesion of Human Blood Platelets to Glass and Polymer Surfaces
Authors: Mohammad Fazal , Hardison M.D. , Chuang H.Y.K. , Mason R.G.
Published: April 2009

Adhesiveness of washed platelets resuspended in citrated plasma, serum, or several different media has been investigated. A method specific for quantitation of adhesion was used. Platelets suspended in saline or Tyrode’s solution were found to be highly adhesive to glass, polyethylene, polyvinyl chloride, or Cuprophane. This adhesiveness of platelets to test surfaces decreased by nearly 50% when plasma was the suspension medium. When the suspension medium was serum, the decrease in adhesion was nearly 75 %. Cohn fraction V also decreased the adhesiveness of platelets significantly, but highly purified albumin had only a small effect. Several pharmacologic agents decreased platelet adhesiveness when added to platelets suspended in plasma or serum, but had negligible effect on the adhesiveness of platelets suspended in artificial media devoid of proteins. Normal washed platelets, when suspended in citrated plasma obtained from an afibrino-genemic donor or in normal serum, showed a significant decrease in adhesion compared to the same platelets suspended in normal citrated plasma. Addition of fibrinogen to afibrinogenemic plasma or normal serum restored the adhesiveness of platelets to normal levels. Normal platelets resuspended in plasma obtained from a thrombasthenic donor exhibited normal adhesiveness. These observations suggested that while fibrinogen promotes platelet adhesion, plasma or serum possess also an adhesion-inhibiting activity.
Sonography: A Method for Localization of Hematomas in Hemophiliacs
Authors: Nowotny C. , Niessner H. , Thaler E. , Lechner K.
Published: April 2009

Sonography was used to visualize hematomas in hemophilic patients. The method is especially helpful for the diagnosis of psoas hematoma and retroperitoneal hematoma and allows the follow-up of hematomas of the cervical region and muscle hematomas. The method is simple, rapid, painless and has no known adverse effects.
Stimulation of Human Platelet Aggregation by Phospholipase-A and a Saline ‘Extract’ of a Polyurethane
Authors: Iatridis Sotirios G. , Iatridis Panayotis G. , Tsiala-Paraschou Elly , Markidou Sofia G. , Ragatz Barth H.
Published: April 2009

A saline extract of polyurethane (SPU) induces enzymatic conversion of arachidonic acid (either exogenous or released through the action of exogenous phospholipase-A) by activating a hitherto undiscovered labile enzyme, synthetase-α which is not blocked by aspirin. Addition of SPU plus arachidonic acid or SPU plus phospholipase-A to platelet-rich plasma (PRP) triggers a biphasic platelet aggregation. Incubation of SPU with PRP results in activation and exhaustion of synthetase-α; this renders platelets refractory to the various aggregating agents.
Factor-VIII-Related Antigen and Cold-Insoluble Globulin in Leukemias and Carcinomas
Authors: Bruhn H.D. , Heimburger N.
Published: April 2009

An elevated plasma level of the factor-VIII-related antigen is not specific for leukemias and malignancies but is also observed in inflammations and in rheumatic diseases. As a reason for this nonspecific change an increased tissue breakdown has to be considered as well as an impaired elimination of the protein, possibly in some cases in the course of a consumption coagulopathy. The plasma levels of the cold-insoluble globulin were reduced in chronic lymphatic leukemias and in acute inflammations, but elevated in rheumatic diseases. Production and liberation of the cold-insoluble globulin may not only be changed by malignant transformation of cells but also by inflammatory and infectious processes.
Rat Liver Macrophages will not Phagocytose Fibrin during Disseminated Intravascular Coagulation
Authors: Emeis J.J. , Lindeman J.
Published: April 2009

Disseminated intravascular coagulation was induced in rats by injection of a silver colloid suspension or thrombin. Ten min after the injection of colloid, fibrin deposits were observed light microscopically in all major organs. At 30 min, fibrin was no longer present. In rats treated with antifibrinolytics (e-aminocaproic acid or Trasylol®) fibrin was still present at 30 and 60 min. Interaction of fibrin with Kupffer cells was studied by electron microscopy. At 3, 10, and 20 min after the colloid injection, all fibrin occurred extracellularly, close to the surface of Kupffer cells. At 30 min, all fibrin had disappeared. In rats pretreated with antifibrinolytics, too, all fibrin was found extracellularly at 10, 30, and 60 min. Comparable results were obtained when thrombin was used to induce coagulation. It is concluded that removal of native fibrin from the circulation by Kupffer-cell phagocytosis is unlikely.
Purification of a Plasminogen Activator Inhibitor Indistinguishable from α1-Antitrypsin and an Urokinase Inhibitor in Pregnancy Plasma
Authors: Clemmensen Inge , Thorsen Sixtus , Müllertz Sten
Published: April 2009

An inhibitor of urokinase present in increased concentrations in plasma during pregnancy was purified. The inhibitor was identified by its pronounced effect on urokinase-induced fibrinolysis as opposed to the absence of effect on fibrinolysis induced by a tissue plasminogen activator. The inhibitor progressively inactivated urokinase upon incubation and was found to be indistinguishable from α1-antitrypsin.
Combined Administration of Low Dose Heparin and Aspirin as Prophylaxis of Deep Vein Thrombosis after Hip Joint Surgery
Authors: Schöndorf Theodor H. , Hey Dieter
Published: April 2009

The study was carried out on 75 patients undergoing hip joint surgery. The efficacy of a prophylaxis of deep vein thrombosis (DVT) by acetylsalicylic lysine (ASL) and by a low dose heparin (LDH) combined with the ASL treatment was investigated using the 125I-fibrinogen test. DVT was not significantly decreased by the ASL application (53%) compared to the controls (60%). DVT occurred significantly less under the combined administration (27 %) than in the other two groups.
Changes in Coagulation Factors Following Acute Myocardial Infarction in Man
Authors: Rennie J.A.N. , Ogston D.
Published: April 2009

The whole blood clotting time, plasma fibrinogen and individual coagulation factors II, V, VII, VIII, IX, X, XI and XII were serially measured in 14 patients over a 10-day period following acute myocardial infarction. A further six patients with similar symptoms but without evidence of myocardial infarction were also studied. The whole blood clotting time was significantly shorter within the first 24 h after infarction than on subsequent days. There were significant increases in the levels of fibrinogen and of factors VIII, IX and XI and a significant decrease in factor XII in the patients who had sustained a myocardial infarction. The patients without myocardial infarction had no significant change in any of the coagulation factors measured.
Antifactor Xa Activity Measured with Amidolytic Methods
Authors: Ødegård O.R. , Lie M. , Abildgaard U.
Published: April 2009

Methods for the assay of antifactor Xa activity in the presence and absence of heparin are described. Diluted plasma is incubated with bovine, activated factor X (Xa) in stage I and remaining Xa is measured with the chromogenic substrate Bz-Ile-Glu-Gly-Arg-pNA in stage II. In the presence of heparin, the inactivation is completed in 30 sec, and this method measures total Xa-inactivating capacity in diluted plasma (Method I). In a clinical material, this capacity showed a strong positive correlation (r = 0.85) to the thrombin-inacti-vating capacity of diluted heparinized plasma (heparin cofactor activity) and apparently reflects antithrombin III (At-III) concentration. In the absence of heparin, the inactivation of factor Xa occurs slowly. With an incubation of 5 min, about 25 % of Xa is inactivated, and this assay reflects initial inactivation of Xa (Method II). With this method, a positive, but less strong correlation to the throm-bin-inactivating capacity was found (r = 0.58), indicating that inhibitors different from At-III accounts for a minor part of the initial inactivation. Determinations in plasma, in which At-III was removed by immunoadsorption, indicated that At-III accounts for about 80% of the initial inactivation. The results of the assays are not significantly influenced by varying concentrations of fibrinogen, fibrinogen degradation products or heparin in the test plasma.
Von Willebrand’s Syndrome Studies on a Variant Factor VIII
Authors: Hill F.G.H. , Chan M.C.K. , Hardisty R.M.
Published: April 2009

A girl with symptoms of von Willebrand’s disease was found to have a slightly reduced or normal FVIII procoagulant activity, normal FVIII-related antigen (VIIIR :AG) and virtually absent von Willebrand’s factor. The electrophoretic mobility of the VIIIR :AG in this patient’s plasma and plasma fractions was increased and has been compared with that of two reported patients with FVIII variants. Her lysed platelets contained increased amounts of VIIIR:AG, which had an increased anodal migration identical to her plasma VIIIR: AG. Experiments involving the selective absorption of a rabbit antiserum with the patient’s plasma provide evidence that VIIIR :AG and von Willebrand’s factor are immunologically distinct.
Evaluation of Hypercoagulability in Septic Abortion
Authors: Graeff H. , Ernst E. , Bocaz J.A. , von Hugo R. , Hafter R.
Published: April 2009

Soluble fibrin monomer complexes (SFMC) were determined in patients with septic abortion (body temperatures of more than 39 °C and/or chills without apparent signs of endotoxic shock), with infected abortion, with non-infected abortion and with normal pregnancies. Quantitative gel filtration (4% agarose) of β-alanine precipitated plasma samples yielded the relative (percent of total fibrinogen content) and absolute (mg/l00 ml plasma) amount of SFMC. The relative (5.5 ± 1.4%, mean ± SD) and absolute (21.5 ± 8.6 mg/l00 ml) amount of SFMC was significantly increased in patients with septic abortion compared to patients with normal pregnancies or non-infected abortion (p < 0.001). Patients with infected abortion already revealed increased levels of SFMC (4.3 ± 1.2%, 14.2 ± 6.8 mg/l00 ml) though their platelet count was still unaltered (infected abortion: 221 ± 47 × 103 platelets/mm3; septic abortion: 99 ± 36 × 103 platelets/mm3). The use of heparin in patients with septic abortion resulted in a decrease in SFMC. Chain characterization of SFMC frequently revealed a slight degradation of the α-chains probably due to fibrinolytic activity in vivo; γ-γ dimers representing inter-molecular covalent bindings were not observed. The findings are in agreement with our former assumption that patients with septic abortion have a pronounced state of hypercoagulability.
Inhibition of Human Platelet Aggregation by the Proteolytic Effect of Streptokinase Role of the Human Factor-VIII-Related Protein
Authors: Castillo Ricardo , Maragall Santiago , Guisasola Javier Alvarez , Casals Francisco , Profitós Juan , Ordinas Antonio
Published: April 2009

Defective ADP-induced aggregation was observed in in vitro streptokinase (SK)-treated normal platelet-rich plasma. Classic haemophilia and normal platelet-poor plasmas (PPP) treated with SK inhibit the aggregation of washed platelets; plasmin-treated normal human serum also shows an inhibitory effect on platelet aggregation. However, SK-treated von Willebrand plasmas do not inhibit the aggregation of washed platelets. This confirms the fact that the anti-aggregating effect is mainly linked to the digested factor VIII but not to the digested fibrinogen. Defective ristocetin-induced platelet aggregation has also been observed in SK-treated plasmas. The presence of normal PPP does not modify the inhibition of the ADP-induced aggregation of washed platelets in SK-treated PPP. However, it does correct the ristocetin-induced aggregation. These results suggest that the inhibition of the ADP-induced aggregation is caused by the factor VIII degradation products, while the inhibition of the ristocetin-induced aggregation appears because of a defective von Willebrand activity of the factor VIII molecule.
Purification and Immunochemical Characterization of Human Plasma Factor XIII
Authors: Kazama M. , McDonagh Jan , Wagner R.H. , Langdell R.D. , McDonagh R.P.
Published: April 2009

A detailed study of the conditions for purification of plasma factor XIII was undertaken and an optimal procedure developed. This procedure involves adsorption with aluminum hydroxide, repeated fractionation with ammonium sulfate, heat denatura-tion of fibrinogen, precipitation with polyethylene glycol, cryoprecipitation, and chroma-tography on DEAE-cellulose with gradient elution. The specific activity of the final product, as measured by the fluorescent amine incorporation assay for factor XIII, averages about 3,000–4,000 μmol dansylcadaverine incorporation/mg protein. The yield is about 20%. In SDS electrophoresis the final product has two bands under nonreducing conditions, characteristic of the a and b subunits.
Treatment of Thrombosis by Sequential Therapy with Ancrod Followed by Streptokinase Clinical Pharmacology and Rheology
Authors: Forbes C.D. , Barbenell J. , Prentice C.R.M.
Published: April 2009

The effects of sequential therapy with ancrod followed by streptokinase are reported in a series of patients with thrombotic disease. Measurements have been made in blood coagulation, fibrinolysis and whole blood and plasma viscosity. Intravenous infusion of ancrod resulted in a significant reduction in plasma fibrinogen which was associated with highly significant reduction in both plasma and whole blood viscosity. Sequential therapy with streptokinase resulted in a gradual rise in fibrinogen and a slight but significant rise in whole blood and plasma viscosity. All patients showed clinical improvement and no haemorrhagic complications resulted.
Distribution and Variation of Fibrinolytic Activity in the Walls of Human Arteries and Veins
Authors: Noordhoek Hegt V.
Published: April 2009

A systematic study on the location and intensity of the fibrinolytic activity in more than 500 samples of human arteries and veins from 50 routine necropsies and 35 blood vessel biopsies was performed. Data were obtained for an overall comparison of the fibrinolytic activity along and across the walls of human blood vessels by the use of a standardized fibrin slide technique. Arteries generally showed little or no fibrinolytic activity in the intima and media but strong activity in the adventitia. Veins showed a comparable strong fibrinolytic activity in the external layer of loose connective tissue. Fibrinolytic activity in the venous intima, media and adventitia was generally weaker but varied greatly according to position in the body. Veins situated in the lower parts of the body had less fibrinolytic activity than the veins at the upper levels. Fibrinolytic activity was found to be related to the endothelium of the vasa vasorum and/or of the main lumen of the vascular wall. Increased fibrinolytic activity was observed in arteries and veins in cases of sudden death, vasogenic shock, cerebral hemorrhage and cirrhosis. Decreased fibrinolytic activity was encountered in blood vessels in cases of endotoxin shock, hyaline membrane disease and a case of Waterhouse-Friderichsen syndrome.
Fibrin(-ogen) Interactions with Plasmin
Authors: Gaffney Patrick J.
Published: April 2009

This is a brief review of the major events which take place when plasmin reacts with fibrinogen (fibrinogenolysis) and fibrin (fibrinolysis). An effort is made to interrelate the locations of the major products of fibrinogenolysis (X, Y, D and E) in the originating fibrinogen molecule. The complexity of the lysates of fibrins, cross-linked by factor XIII to varying extents, is discussed. Clinical and structural implications of two fragments (D dimer and the D dimer-E complex) unique to cross-linked fibrin digests, are highlighted.
Use of Rabbit Antisera in the Preparation of Factor-XII-Free Platelet-Rich and Platelet-Poor Plasma
Authors: Muntz R.H. , Castaldi P.A.
Published: April 2009

Antibodies were raised in rabbits against purified human factor XII and insolubilized on Sepharose. This preparation of insolubilized anti-factor XII antibody was used to prepare factor-XII-free human platelet-rich and platelet-poor plasma for use in the study of platelet coagulant activities.
Platelet Activation in Haemostasis
Authors: Huzoor-Akbar H. , Ardlie Neville G.
Published: April 2009

The mechanism of activation of platelets by collagen was examined. Hirudin interfered with the initial collagen-platelet interaction and both hirudin and heparin inhibited collagen-induced release of platelet granular contents. Hirudin completely inhibited the release of both [3H]5HT and β-glucuronidase whereas heparin completely inhibited release of β-glucuronidase but only partly inhibited release of [3H] 5HT. β-glucuronidase and maximal [3H]5HT were only released when plasma was present. The results are compatible with an essential intermediary role for thrombin in collagen activation of platelets. Evidence was also obtained that von Willebrand factor may participate in this reaction.