fibrin and Pulmonary-Embolism

Prothrombotic fibrin clot phenotype, involving faster formation of dense meshwork composed of thinner and highly branched fibers that are relatively resistant to plasmin-induced lysis, has been reported in patients with not only myocardial infarction or stroke, but also venous thromboembolism (VTE), encompassing deep vein thrombosis (DVT), and/or pulmonary embolism (PE). Prothrombotic fibrin clot phenotype, in particular prolonged clot lysis time, is considered a novel risk factor for VTE as well as venous thrombosis at unusual location, for example, cerebral sinus venous thrombosis, retinal vein obstruction, and Budd-Chiari syndrome. Growing evidence from observational studies indicates that abnormal fibrin clot properties can predict recurrent DVT and PE and they are involved in serious complications of VTE, for example, thromboembolic pulmonary hypertension and postthrombotic syndrome. The purpose of this article is to review our current understanding of the role of fibrin clot structure and function in venous thrombosis with emphasis on clinical issues ranging from prognosis to therapy.

Topics: Fibrin; Humans; Pulmonary Embolism; Recurrence; Risk Factors; Venous Thrombosis

Pulmonary embolism remains a common and potentially preventable cause of death.. This article reviews the epidemiology, clinical features, diagnostic process, and treatment of pulmonary embolism.. Well recognised risk factors include recent hospitalisation, other causes of immobilisation, cancer, and oestrogen exposure. Diagnostic algorithms for pulmonary embolism that incorporate assessment of pretest probability and D-dimer testing have been developed to limit the need for diagnostic imaging. Anticoagulation should be administered promptly to all patients with pulmonary embolism with low molecular weight heparin being the initial anticoagulant of choice, although thrombolysis is indicated for patients presenting with haemodynamic compromise. Following initial anticoagulation warfarin therapy should be continued for a minimum of 3 months. Long term anticoagulation with warfarin should be considered in patients with unprovoked pulmonary embolism, due to an increased risk of recurrence after ceasing anticoagulation. The availability of new anticoagulants is likely to significantly impact on the treatment of patients with pulmonary embolism, although the exact role of these drugs is still to be defined.

Topics: Algorithms; Anticoagulants; Antifibrinolytic Agents; Australia; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolytic Agents; Heparin, Low-Molecular-Weight; Humans; Pulmonary Embolism; Risk Assessment; Risk Factors; Venous Thromboembolism

The D-dimer antigen is a unique marker of fibrin degradation that is formed by the sequential action of 3 enzymes: thrombin, factor XIIIa, and plasmin. First, thrombin cleaves fibrinogen producing fibrin monomers, which polymerize and serve as a template for factor XIIIa and plasmin formation. Second, thrombin activates plasma factor XIII bound to fibrin polymers to produce the active transglutaminase, factor XIIIa. Factor XIIIa catalyzes the formation of covalent bonds between D-domains in the polymerized fibrin. Finally, plasmin degrades the crosslinked fibrin to release fibrin degradation products and expose the D-dimer antigen. D-dimer antigen can exist on fibrin degradation products derived from soluble fibrin before its incorporation into a fibrin gel, or after the fibrin clot has been degraded by plasmin. The clinical utility of D-dimer measurement has been established in some scenarios, most notably for the exclusion of VTE. This article consists of 2 sections: in the first, the dynamics of D-dimer antigen formation is discussed and an overview of commercially available D-dimer assays is provided. The second section reviews available evidence for the clinical utilization of D-dimer antigen measurement in VTE, as well as emerging areas of D-dimer utilization as a marker of coagulation activation in other clinical settings.

Topics: Algorithms; Antibodies, Monoclonal; Clinical Laboratory Techniques; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Immunoassay; Models, Biological; Protein Structure, Tertiary; Pulmonary Embolism; Venous Thromboembolism; Venous Thrombosis

The reliability of D-dimer (NycoCard D-dimer) and CRP (C-reactive protein) tests to exclude suspected deep venous thrombosis (DVT) and pulmonary embolism (PE) was investigated in 116 patients. Venography, ultrasonography or ventilation-perfusion lung scanning was used as the control method in 95, 5, and 14 patients, respectively, and pulmonary angiography in two patients, one of whom also underwent lung scanning, the other venography. Of the 116 patients, 52 had thromboembolism (46 DVT and 6 PE). The respective sensitivity, specificity, and negative and positive predictive values (NPV, PPV) were 94%, 27%, 85% and 51% for the D-dimer test, and 80%, 53% 76% and 60% for the CRP test. As venous thromboembolism is a life-threatening condition, the NPV of an exclusion test must lie very close to 100 per cent, and thus the study showed neither the D-dimer nor the CRP test to be a satisfactory exclusion test for use in cases of suspected DVT or PE.

Topics: C-Reactive Protein; Evaluation Studies as Topic; Fibrin; Humans; Predictive Value of Tests; Pulmonary Embolism; Radiography; Sensitivity and Specificity; Thrombophlebitis

Pulmonary vascular inflammatory disorders may involve all components of the pulmonary vasculature, including capillaries. The principal histopathologic features of pulmonary capillaritis include capillary wall necrosis with infiltration by neutrophils, interstitial erythrocytes, and/or hemosiderin, and interalveolar septal capillary occlusion by fibrin thrombi. Immune complex deposition is variably present. Patients often present clinically with diffuse alveolar hemorrhage, which is characterized by dyspnea and hemoptysis; diffuse, bilateral, alveolar infiltrates on chest radiograph; and anemia. Pulmonary capillaritis has been reported with variable frequency and severity as a manifestation of Wegener's granulomatosis, microscopic polyarteritis, systemic lupus erythematosus, Goodpasture's syndrome, idiopathic pulmonary renal syndrome, Behçet's syndrome, Henoch-Schönlein purpura, IgA nephropathy, antiphospholipid syndrome, progressive systemic sclerosis, and diphenylhydantoin use. In addition to history, physical examination, and routine laboratory studies, certain ancillary laboratory tests, such as antineutrophil cytoplasmic antibodies, antinuclear antibodies, and antiglomerular basement membrane antibodies, may help diagnose an underlying disease. Diagnosis of pulmonary capillaritis can be made by fiberoptic bronchoscopy with transbronchial biopsy, but thoracoscopic biopsy is often employed. Since many disorders can result in pulmonary capillaritis with diffuse alveolar hemorrhage, it is crucial for clinicians and pathologists to work together when attempting to identify an underlying disease. Therapy depends on the disorder that gave rise to the pulmonary capillaritis and usually includes corticosteroids and cyclophosphamide or azathioprine. Since most diseases that result in pulmonary capillaritis are treated with immunosuppression, infection must be excluded aggressively.

Topics: Anemia; Bronchoscopy; Capillaries; Diagnosis, Differential; Dyspnea; Erythrocytes; Fibrin; Hemoptysis; Hemorrhage; Hemosiderin; Humans; Immunosuppressive Agents; Lung; Lung Diseases; Necrosis; Neutrophils; Pulmonary Alveoli; Pulmonary Embolism; Thoracoscopy; Vasculitis

Pulmonary microembolism results in lung vascular injury characterized by an increase in the transport of the pulmonary micro- vascular barrier into proteins. The increase in lung vascular permeability is a primary factor responsible for the protein-rich oedema associated with pulmonary microembolism. The microembolism can result from a variety of causes, but an essential feature of it is the "plugging" of pulmonary microvessels with thrombi; that is, the entrapment of fibrin and blood-formed elements in pulmonary microvessels. Neutrophil-derived products released subsequent to neutrophil activation are primary mediators of lung vascular injury. The attachment of neutrophils to the endothelial cell is a requisite for the development of endothelial injury. Fibrin itself plays another important role in that fibrin promotes neutrophil adhesiveness and releases factors such as fibrin degradation products which may increase endothelial permeability. Therefore, pulmonary microembolism is a determinant of acute lung microvascular injury and is a factor in the pathogenesis of the adult respiratory distress syndrome. Neutrophils are important effector cells mediating lung microvascular injury, although the factors that are responsible for neutrophil sequestration and activation remain unclear.

Topics: Animals; Blood Platelets; Capillary Permeability; Fibrin; Free Radicals; Humans; Lung; Macrophages; Neutrophils; Pulmonary Circulation; Pulmonary Embolism; Respiratory Distress Syndrome

Topics: Animals; Clinical Enzyme Tests; Coronary Disease; Diagnosis, Differential; Dogs; Fibrin; Fibrin Fibrinogen Degradation Products; Heparin; Humans; Hypertension; Lung Diseases; Myocardial Infarction; Pulmonary Embolism; Solubility; Thrombophlebitis

The existence of a system in the human body capable of inducing the dissolution of endogenous pathologically formed thrombi was appreciated in ancient times. Considered in detail in this article are the data that have elucidated the physiologic regulation of which plasmin formation is dependent on, the plasma concentration of plasminogen, availability of activators of plasminogen in the plasma and surrounding tissue environment, the concentration of naturally present inhibitors, and the existence of fibrin in the circulation. Important in this rapidly progressive scientific discipline is consideration of the factors which control the synthesis of the components of this proteolytic enzyme system. Recently abundant information has indicated that this plasminogen-plasmin proteolytic enzyme system can be utilized therapeutically. Knowledge of the mechanisms of this system has permitted identification of agents that can be exogenously administered to releave thrombotic obstruction to blood flow in the venous (pulmonary emboli, deep vein thrombosis) and arterial (peripheral and central vessels) circulatory systems. Particularly important is the demonstration that thrombolytic agents can directly attack and alleviate the immediate cause of acute myocardial infarction. As a result of the innovations in the present decade, it is evident that the plasminogen system can be advantageously employed to reverse the pathologic effects of all thrombotic diseases.

Topics: alpha 1-Antitrypsin; alpha-2-Antiplasmin; alpha-Macroglobulins; Antifibrinolytic Agents; Antithrombin III; Arterial Occlusive Diseases; Arteriosclerosis; Complement C1 Inactivator Proteins; Disseminated Intravascular Coagulation; Fibrin; Fibrinogen; Fibrinolysin; Fibrinolysis; Fibrinolytic Agents; Humans; Kidney Diseases; Liver Diseases; Myocardial Infarction; Neoplasms; Plasminogen; Pulmonary Embolism; Thrombophlebitis

Clinical and autopsy studies have shown an association between clotting, microembolism, and inhibition of fibrinolysis and respiratory distress after trauma or sepsis. Prophylaxis and treatment with the aim of decreasing the deposition of fibrin in the lungs were associated with a large decrease in the incidence and death rate of this syndrome. Small fibrin degradation products (peptides) are accumulated in the lungs and are only slowly cleared from this organ, especially during states of inhibition of fibrinolysis. These peptides may contribute to the pulmonary damage in several ways. As well as having a direct effect on the endothelium, they act by interfering with other vasoactive substances as bradykinin, histamine, and products of the arachidonic acid cascade. Products of the cyclooxygenase pathway such as thromboxane A2 play a major role in early microembolism, whereas lipoxygenase products seem to be involved in later stages. Pulmonary microembolism thus seems to be one important, but certainly not the only, pathogenetic factor in acute "idiopathic" respiratory failure. Other factors, such as pulmonary contusion, aspiration of gastric contents or blood, or oxygen toxicity, might well be contributory in some cases. Pulmonary microemboli containing fibrin and leukocytes are probably also involved as contributory agents in some cases in the large group of acute respiratory failures due to "known factors."

Topics: Albumins; Animals; Clinical Trials as Topic; Dextrans; Dogs; Fibrin; Fibrinolysis; Hemostasis; Heparin; Humans; Lung; Pulmonary Embolism; Random Allocation; Rats; Respiratory Distress Syndrome; Syndrome; Thrombin; Time Factors

Topics: Animals; Blood Platelets; Blood Preservation; Blood Transfusion; Cell Aggregation; Disease Models, Animal; Dogs; Fibrin; Humans; Leukocytes; Micropore Filters; Papio; Platelet Aggregation; Postoperative Complications; Pulmonary Embolism; Respiratory Distress Syndrome; Transfusion Reaction

Topics: Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelets; Blood Vessels; Cardiopulmonary Bypass; Disseminated Intravascular Coagulation; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Humans; Infant, Newborn; Kidney Diseases; Myocardial Infarction; Neoplasms; Pregnancy; Pulmonary Embolism; Syndrome; Thrombin; Thrombophlebitis; Thrombosis

This report describes how a finding at the autopsy table led to the observation of a clinical syndrome. A synthesis of autopsy experience, clinical investigations, and experimental and biochemical studies were able to shed light on one factor in the pathogenesis of this syndrome, namely blood coagulation with pulmonary microemboli and release and delayed elimination of peptides from fibrin degradation extravascularly in the lungs. These peptides may both induce increased permeability in the microcirculation and stimulate fibroblast proliferation. Knowledge about the pathogenesis has led to improved prophylaxis and therapy and a reduction of the number of deaths.

Topics: Antifibrinolytic Agents; Autopsy; Blood Coagulation; Capillary Permeability; Cell Division; Embolism, Fat; Fibrin; Fibrin Fibrinogen Degradation Products; Fibroblasts; Humans; Microcirculation; Pulmonary Embolism; Shock; Syndrome

Fibrinogen plays a pivotal role in both the humoral and cellular mechanisms involved in hemostasis. In performing its hemostatic function, fibrinogen in turn is acted on by several independent enzyme systems that either modify its structure or cleave specific fragments of the molecule into the surrounding milieu. Measurements of enzymatically modified fibrinogen or its proteolysis products represent a means whereby the action of these specific enzymes can be quantitated both in vitro and in vivo. Advances in such techniques as protein purification, affinity chromatography, peptide synthesis, and radioimmunoassay technology permit the translation of recently acquired primary structural data on this important protein into sensitive and specific assays for its circulating derivatives. These assay systems are important tools for probing mechanisms of hemostasis and thrombosis.

Topics: Ancrod; Blood Coagulation Tests; Chemical Phenomena; Chemistry, Physical; Chromatography, Gel; Disseminated Intravascular Coagulation; Fibrin; Fibrinogen; Fibrinolysin; Fibrinopeptide A; Fibrinopeptide B; Humans; Kinetics; Leukocytes; Peptide Hydrolases; Pulmonary Embolism; Thrombin; Thrombophlebitis

Topics: Adenosine Diphosphate; Blood Platelets; Coronary Vessels; Dyspnea; Fibrin; Histamine; Humans; Hypertension; Hypoxia; Platelet Factor 4; Prostaglandins; Pulmonary Embolism; Serotonin

Topics: Adolescent; Adult; Antithrombin III; Blood Coagulation; Blood Coagulation Disorders; Child; Factor IX; Factor V; Factor VIII; Fibrin; Fibrinogen; Humans; Pulmonary Embolism; Thrombophlebitis

Topics: Animals; Antifibrinolytic Agents; Autopsy; Blood Coagulation Factors; Dogs; Fibrin; Fibrinolysis; Fibrinolytic Agents; Heart Failure; Humans; Hypoxia; Kidney; Lung; Lymph; Plasminogen Activators; Plasminogen Inactivators; Prostaglandins; Pulmonary Embolism; Pulmonary Veins; Respiration; Respiratory Insufficiency; Syndrome; Thrombin; Wounds and Injuries

Topics: Airway Obstruction; Angiography; Animals; Anticoagulants; Dyspnea; Electrocardiography; Fibrin; Fibrinogen; Fibrinolytic Agents; Heart Auscultation; Heparin; Humans; Ligation; Pulmonary Artery; Pulmonary Embolism; Radionuclide Imaging; Thrombophlebitis; Vena Cava, Inferior

Topics: Adenine Nucleotides; Animals; Anti-Inflammatory Agents; Anticholesteremic Agents; Anticoagulants; Aspirin; Blood Platelets; Butyrates; Dextrans; Dietary Fats; Dipyridamole; Ethylestrenol; Fibrin; Fibrinolytic Agents; Histamine H1 Antagonists; Humans; Phenformin; Phenylbutazone; Platelet Adhesiveness; Povidone; Prostaglandins; Pulmonary Embolism; Rabbits; Streptodornase and Streptokinase; Thrombophlebitis; Thrombosis; Vasodilator Agents; Venoms

Topics: Aminocaproates; Fibrin; Fibrinogen; Fibrinolysin; Fibrinolysis; Fibrinolytic Agents; Humans; In Vitro Techniques; Infusions, Parenteral; Injections, Intravenous; Nicotinic Acids; Peptide Hydrolases; Plasminogen; Pulmonary Embolism; Thromboembolism; Thrombophlebitis; Thrombosis; Trypsin

Topics: Abruptio Placentae; Amniotic Fluid; Embolism, Air; Embolism, Fat; Female; Fetal Death; Fibrin; Humans; Inhalation; Pregnancy; Pregnancy Complications, Cardiovascular; Pulmonary Circulation; Pulmonary Embolism; Pulmonary Heart Disease; Thrombophlebitis

Hyperhomocysteinemia (HHcy) affects haemostasis and shifts its balance in favour of thrombosis. In vitro and in vivo studies suggested that HHcy may impair fibrinolysis either by influencing the plasma levels of fibrinolytic factors or by altering the fibrinogen structure. We investigated the influence of mild HHcy levels on plasma fibrinolytic potential by using clot lysis time (CLT) and fibrin susceptibility to plasmin-induced lysis in 94 patients with previous pulmonary embolism and no pulmonary hypertension. CLT was measured as lysis time of tissue factor induced clots exposed to exogenous tissue plasminogen activator (t-PA). The rate of in vitro plasmin-mediated cleavage of fibrin β-chain was assessed over a 6-h period on fibrin clots, which were obtained by exposition to thrombin of purified fibrinogen. Homocysteine plasma levels were measured by Abbott Imx immunoassay and we considered as altered the values above 15 μmol/L according to the literature. In 68 patients homocysteine levels were below 15 μmol/L (NHcy) and in 26 they were above (HHcy). Significant differences were observed between the two groups regarding plasma fibrinolytic potential (p = 0.016), TAFIact (expressed as clot lysis ratio) (p = 0.02), t-PA (0.008) and PLG (0.037), but not for the other assessed components. The HHcy-patients had a threefold higher risk to have an impaired fibrinolysis. Instead, a multivariate logistic regression analysis adjusted for significances of univariate showed that HHcy (OR 5.2 95% CI 1.7-15.9; p = 0.003) and BMI (OR 5.0 95% CI 1.6-15.9; p = 0.006) resulted independently associated with impaired fibrinolytic activity. HHcy affects TAFI-mediated hypofibrinolysis but not fibrin(ogen) structure or function as documented by fibrin degradation analysis.

Topics: Adult; Aged; Aged, 80 and over; Female; Fibrin; Fibrinolysin; Fibrinolysis; Humans; Hyperhomocysteinemia; Male; Middle Aged; Proteolysis; Pulmonary Embolism; Risk Factors

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Predictive Value of Tests; Pulmonary Embolism; Sensitivity and Specificity; Upper Extremity; Venous Thrombosis

Little is known about the differences between unfractionated heparin (UFH) and low molecular weight heparin (LMWH) with regard to their effects on coagulation activity during treatment for pulmonary embolism. The objective of this study was to compare UFH and LMWH (dalteparin) in the early treatment of pulmonary embolism in terms of control of coagulation markers and perfusion abnormalities. Thirty-seven patients with acute pulmonary embolism were randomized to receive intravenous UFH or subcutaneous dalteparin, each accompanied by acenocoumarol. Daily blood samples were obtained for the measurement of thrombin generation (fragments 1 and 2 [F1+2], thrombin-antithrombin (TAT) complexes and fibrin monomers [FMs]) and fibrinolysis (d-dimer concentrations and clot-lysis times). Ventilation-perfusion scintigraphies were performed, and with the data they yielded, percentage of vascular obstruction scores (PVOs) were calculated on days 0 and 5. The international normalized ratio was within the therapeutic range in both groups on day 3. F1+2 and TAT complexes rapidly normalized, without differences between the groups (P =.5 and.4, respectively). FM levels did not decrease and, in fact, showed an increase in the UFH group from day 3 on (P <.05 between groups). d-Dimer levels decreased over time, with no differences between groups (P =.6). Clot-lysis times were shorter in the UFH group (P <.05). PVOs on days 0 and 5 were not different (P =.5 and.8, respectively), but the decrease in PVOs over time was greater in the dalteparin group (P =.04). These results show that dalteparin is at least as effective as UFH in reducing coagulation activity and perfusion abnormalities in the early treatment of pulmonary embolism.

Topics: Adult; Aged; Aged, 80 and over; Anticoagulants; Female; Fibrin; Fibrinolysis; Heparin; Heparin, Low-Molecular-Weight; Humans; Infusions, Intravenous; Male; Middle Aged; Partial Thromboplastin Time; Pulmonary Embolism; Thrombin; Time Factors

Clinical and autopsy studies have shown an association between clotting, microembolism, and inhibition of fibrinolysis and respiratory distress after trauma or sepsis. Prophylaxis and treatment with the aim of decreasing the deposition of fibrin in the lungs were associated with a large decrease in the incidence and death rate of this syndrome. Small fibrin degradation products (peptides) are accumulated in the lungs and are only slowly cleared from this organ, especially during states of inhibition of fibrinolysis. These peptides may contribute to the pulmonary damage in several ways. As well as having a direct effect on the endothelium, they act by interfering with other vasoactive substances as bradykinin, histamine, and products of the arachidonic acid cascade. Products of the cyclooxygenase pathway such as thromboxane A2 play a major role in early microembolism, whereas lipoxygenase products seem to be involved in later stages. Pulmonary microembolism thus seems to be one important, but certainly not the only, pathogenetic factor in acute "idiopathic" respiratory failure. Other factors, such as pulmonary contusion, aspiration of gastric contents or blood, or oxygen toxicity, might well be contributory in some cases. Pulmonary microemboli containing fibrin and leukocytes are probably also involved as contributory agents in some cases in the large group of acute respiratory failures due to "known factors."

Topics: Albumins; Animals; Clinical Trials as Topic; Dextrans; Dogs; Fibrin; Fibrinolysis; Hemostasis; Heparin; Humans; Lung; Pulmonary Embolism; Random Allocation; Rats; Respiratory Distress Syndrome; Syndrome; Thrombin; Time Factors

1. The purpose of fluid administration is not only the restoration of blood volume but also the normalization of impaired nutritive flow. 2. Plasma oncotic (colloid osmotic) pressure is the only force which can draw water into the circulation. In shock the infusion of colloid solutions is able to normalize nutritive flow and peripheral resistance almost at once. 3. Five per cent solutions of pasteurized plasma protein or albumin and 6 per cent dextran 70 yield a volume expansion corresponding to the amount infused. 4. The decrease in hematocrit produced by the infusion of these three colloidal solutions is accompanied by a decrease in whole blood viscosity resulting in a rise in cardiac output as well as in nutritional tissue flow. 5. Hemodilution improves oxygen supply as long as the hematocrit does not fall below 30 per cent, although normovolemia is the critical requirement. 6. Transmission of viral hepatitis is still the greatest danger of blood transfusion. 7. The use of large amounts of Ringer's lactate is not advised, as this solution does not reduce the total number of units of blood which need to be given. Pulmonary edema may become a problem. 8. Dextrans are best suited to initial volume replacement in shock. They increase plasma volume, improve blood flow, have antithrombotic properties, and are easily available and relatively cheap. Anaphylactoid reactions are rare. 9. Every third patient undergoing general surgery and every other patient having hip surgery develops a deep venous thrombosis. Widespread prophylaxis to prevent thromboembolic complications is mandatory. 10. The antithrombotic properties of dextran are due to a reduction in platelet adhesiveness, a change in fibrin clot structure, and the increased lysability of thrombi and the improvement of blood flow. 11. In a personal controlled, prospective, randomezed trial comparing subcutaneous heparin and intravenous dextran 40, 35.8 per cent of the controls (n=95), 13.2 per cent of the 83 patients in the heparin group, and 20.5 per cent in the dextran group (n=83) developed deep venous thrombosis. The difference between dextran and heparin is not significant; however, both treatment groups show a statistically significant effect compared to the controls.

Topics: Blood Coagulation Tests; Blood Transfusion; Bone and Bones; Coumarins; Dextrans; Female; Fibrin; Genital Diseases, Female; Heparin; Humans; Microscopy, Electron, Scanning; Molecular Weight; Phlebography; Postoperative Complications; Prospective Studies; Pulmonary Embolism; Thromboembolism

To identify pulmonary/uterine thrombus formation in amniotic fluid embolism (AFE).. Retrospective, observational.. Nationwide.. Eleven autopsy cases of AFE and control cases.. We assessed pulmonary and uterine thrombus formation and thrombus area in AFE and pulmonary thromboembolism (PTE) as a control. The area of platelet glycoprotein IIb/IIIa, fibrin, neutrophil elastase, citrullinated histone H3 (a neutrophil extracellular trap marker) and mast cell chymase immunopositivity was measured in 90 pulmonary emboli, 15 uterine thrombi and 14 PTE.. Pathological evidence of thrombus formation and its components in AFE.. Amniotic fluid may induce distinct thrombus formation in the uterus and lung. Pulmonary and uterine thrombi formation may contribute to cardiorespiratory collapse and/or consumptive coagulopathy in AFE.

Topics: Autopsy; Embolism, Amniotic Fluid; Female; Fibrin; Histones; Humans; Lung; Pregnancy; Pulmonary Embolism; Retrospective Studies; Thrombosis

Topics: Carboxypeptidase B2; Fibrin; Humans; Pulmonary Embolism; Thrombosis

Lipopolysaccharide (LPS) can traverse the intestinal barrier and enter bloodstream, causing endotoxemia and triggering inflammation. Increased circulating LPS was reported in arterial thromboembolism. We investigated whether increased LPS levels occur in acute pulmonary embolism (PE) and if it is associated with a prothrombotic state.. We studied 120 normotensive PE patients (aged 59 [48-68] years) on admission, after 5-7 days, and after a 3-month anticoagulation. Serum LPS levels, along with zonulin, a marker of gut permeability, endogenous thrombin potential (ETP), fibrin clot permeability (K. Median LPS concentration on admission was 70.5 (61.5-82) pg/mL (min-max, 34-134 pg/mL), in association with C-reactive protein (r = 0.22, p = 0.018), but not with fibrinogen, D-dimer or platelet markers. Patients with more severe PE had higher LPS levels compared with the remainder. Median zonulin level was 3.26 (2.74-4.08) ng/mL and correlated with LPS (r = 0.66, p < 0.0001). Patients with baseline LPS levels in the top quartile (≥82 pg/mL; n = 29) compared to lower quartiles had 18.6 % increased ETP, 14.5 % reduced K. Low-grade endotoxemia is detectable in patients with acute PE and may contribute to increased thrombin generation and PAI-1-mediated hypofibrinolysis.

Topics: Acute Disease; Anticoagulants; Endotoxemia; Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Humans; Lipopolysaccharides; Phenotype; Plasminogen Activator Inhibitor 1; Pulmonary Embolism; Thrombin; Thrombosis

Prothrombotic fibrin clot properties, including increased clot density, are in part genetically determined. We investigated whether fibrinogen alpha-chain gene (FGA) c.991A>G (rs6050), fibrinogen beta chain gene (FGB) -455G>A (rs1800790) and factor XIII gene (F13) c.103G>T (rs5985) polymorphisms affect plasma fibrin clot properties in patients with acute pulmonary embolism (PE).. As many as 126 normotensive patients with PE, free of cancer, were genotyped by TaqMan assay. Fibrin clot permeability (K. The minor allele frequencies were as follows: FGA rs6050 (n = 62, 0.31), FGB rs1800790 (n = 40, 0.17) and F13 rs5985 (n = 49, 0.23). There were no differences related to any of the polymorphisms with regard to demographic, clinical and laboratory data, except for fibrinogen concentration, which was higher in carriers of F13 rs5985 polymorphism (p = .024), and PE combined with deep-vein thrombosis, which was less prevalent in FGB rs1800790 polymorphism carriers (p = .004). Carriers of FGB rs1800790 A allele and F13 rs5985 T allele had lower K. Our study showed that FGB rs1800790 and F13 rs5985 polymorphisms contribute to the prothrombotic fibrin clot phenotype and these effects are strong enough to be observed in the acute phase of PE.

Topics: Acute Disease; Aged; Blood Coagulation; Factor XIII; Female; Fibrin; Fibrinogen; Humans; Male; Middle Aged; Polymorphism, Genetic; Pulmonary Embolism

Blood clots and thrombi undergo platelet-driven contraction/retraction followed by structural rearrangements. We have established quantitative relationships between the composition of blood clots and extent of contraction to determine intravital contraction of thrombi and emboli based on their content. The composition of human blood clots and thrombi was quantified using histology and scanning electron microscopy. Contracting blood clots were segregated into the gradually shrinking outer layer that contains a fibrin-platelet mesh and the expanding inner portion with compacted red blood cells (RBCs). At 10% contraction, biconcave RBCs were partially compressed into polyhedral RBCs, which became dominant at 20% contraction and higher. The polyhedral/biconcave RBC ratio and the extent of contraction displayed an exponential relationship, which was used to determine the extent of intravital contraction of ex vivo thrombi, ranging from 30% to 50%. In venous thrombi, the extent of contraction decreased gradually from the older (head) to the younger (body, tail) parts. In pulmonary emboli, the extent of contraction was significantly lower than in the venous head but was similar to the body and tail, suggesting that the emboli originate from the younger portion(s) of venous thrombi. The extent of contraction in arterial cerebral thrombi was significantly higher than in the younger parts of venous thrombi (body, tail) and pulmonary emboli but was indistinguishable from the older part (head). A novel tool, named the "contraction ruler," has been developed to use the composition of ex vivo thrombi to assess the extent of their intravital contraction, which contributes to the pathophysiology of thromboembolism.

Topics: Arteries; Blood Platelets; Fibrin; Humans; Pulmonary Embolism; Thrombosis

This is a case report about a 7-year-old male child with sickle cell anemia (S/β

Topics: Acute Chest Syndrome; Anemia, Sickle Cell; Autopsy; Child; Fibrin; Humans; Male; Pulmonary Embolism

 Prothrombotic fibrin clot properties are associated with higher early mortality risk in acute pulmonary embolism (PE) patients. It is unknown whether different types of PE are associated with particular clot characteristics..  We assessed 126 normotensive, noncancer acute PE patients (median age: 59 [48-70] years; 52.4% males), who were categorized into central versus peripheral PE with or without concomitant deep vein thrombosis (DVT). Plasma fibrin clot permeability (.  Patients with central PE (.  Our findings suggest that looser fibrin networks composed of thicker fibers with increased susceptibility to lysis characterize patients with central PE, suggesting that fibrin clot phenotype affects the size of thrombi occluding the pulmonary arteries, highlighting the role of fibrin structures in thrombus formation and stability.

Topics: Acute Disease; Aged; Female; Fibrin; Fibrinolysis; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Phenotype; Pulmonary Embolism

Current thrombolytic agents activate plasminogen to plasmin which triggers fibrinolysis to dissolve thrombi. Since plasmin is a nonspecific proteolytic enzyme, all of the current plasmin-dependent thrombolytics lead to serious hemorrhagic complications, demanding a new class of fibrinolytic enzymes independent from plasmin activation and undesirable side effects. We speculated that the mammalian version of bacterial heat-shock proteins could selectively degrade intravascular thrombi, a typical example of a highly aggregated protein mixture.. The objective of this study is to identify enzymes that can dissolve intravascular thrombi specifically without affecting fibrinogen and fibronectin so that the wound healing processes remain uninterrupted and tissues are not damaged. In this study, HtrA (high-temperature requirement A) proteins were tested for its specific proteolytic activity on intravascular thrombi independently from plasmin activation.. HtrA1 and HtrA2/Omi proteins, collectively called as HtrAs, lysed ex vivo blood thrombi by degrading fibrin polymers. The thrombolysis by HtrAs was plasmin-independent and specific to vascular thrombi without causing the systemic activation of plasminogen and preventing nonspecific proteolysis of other proteins including fibrinogen and fibronectin. As expected, HtrAs did not disturb clotting and wound healing of excised wounds from mouse skin. It was further confirmed in a tail bleeding and a rebleeding assay that HtrAs allowed normal clotting and maintenance of clot stability in wounds, unlike other thrombolytics. Most importantly, HtrAs completely dissolved blood thrombi in tail thrombosis mice, and the intravenous injection of HtrAs to mice with pulmonary embolism completely dissolved intravascular thrombi and thus rescued thromboembolism.. Here, we identified HtrA1 and HtrA2/Omi as plasmin-independent and highly specific thrombolytics that can dissolve intravascular thrombi specifically without bleeding risk. This work is the first report of a plasmin-independent thrombolytic pathway, providing HtrA1 and HtrA2/Omi as ideal therapeutic candidates for various thrombotic diseases without hemorrhagic complications.

Topics: Animals; Disease Models, Animal; Female; Fibrin; Fibrinolysis; Fibrinolytic Agents; Hemorrhage; High-Temperature Requirement A Serine Peptidase 1; High-Temperature Requirement A Serine Peptidase 2; Humans; Kinetics; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Pulmonary Embolism; Recombinant Proteins; Thrombosis; Wound Healing

Although arterial and venous thromboembolic disorders are among the most frequent causes of mortality and morbidity, there has been little description of how the composition of thrombi and emboli depends on their vascular origin and age. We quantified the structure and composition of arterial and venous thrombi and pulmonary emboli using high-resolution scanning electron microscopy. Arterial thrombi contained a surprisingly large amount of fibrin, in addition to platelets. The composition of pulmonary emboli mirrored the most distal part of venous thrombi from which they originated, which differed from the structure of the body and head of the same thrombi. All thrombi and emboli contained few biconcave red blood cells but many polyhedrocytes or related forms of compressed red blood cells, demonstrating that these structures are a signature of clot contraction in vivo. Polyhedrocytes and intermediate forms comprised the major constituents of venous thrombi and pulmonary emboli. The structures within all of the thrombi and emboli were very tightly packed, in contrast to clots formed in vitro. There are distinctive, reproducible differences among arterial and venous thrombi and emboli related to their origin, destination and duration, which may have clinical implications for the understanding and treatment of thrombotic disorders.

Topics: Arteries; Blood Coagulation; Blood Platelets; Erythrocytes; Fibrin; Humans; Microscopy, Electron, Scanning; Pulmonary Embolism; Thromboembolism; Veins; Venous Thrombosis

Pulmonary embolism occurs when blood flow to a part of the lungs is blocked by a venous thrombus that has traveled from the lower limbs. Little is known about the mechanical behavior of emboli under compressive forces from the surrounding musculature and blood pressure. We measured the stress-strain responses of human pulmonary emboli under cyclic compression, and showed that emboli exhibit a hysteretic stress-strain curve. The fibrin fibers and red blood cells (RBCs) are damaged during the compression process, causing irreversible changes in the structure of the emboli. We showed using electron and confocal microscopy that bundling of fibrin fibers occurs due to compression, and damage is accumulated as more cycles are applied. The stress-strain curves depend on embolus structure, such that variations in composition give quantitatively different responses. Emboli with a high fibrin component demonstrate higher normal stress compared to emboli that have a high RBC component. We compared the compression response of emboli to that of whole blood clots containing various volume fractions of RBCs, and found that RBCs rupture at a certain critical stress. We describe the hysteretic response characteristic of foams, using a model of phase transitions in which the compressed foam is segregated into coexisting rarefied and densified phases whose fractions change during compression. Our model takes account of the rupture of RBCs in the compressed emboli and stresses due to fluid flow through their small pores. Our results can help in classifying emboli as rich in fibrin or rich in red blood cells, and can help in understanding what responses to expect when stresses are applied to thrombi in vivo.

Topics: Erythrocytes; Fibrin; Humans; Pressure; Pulmonary Embolism; Veins

Venous thromboembolism is associated with formation of denser fibrin clots resistant to lysis. We investigated whether prothrombotic plasma clot properties are associated with the severity of acute pulmonary embolism (PE). We enrolled 126 normotensive acute PE patients (aged 58 ± 14 years) and 25 age- and sex-matched healthy controls. Plasma fibrin clot permeability (K

Topics: Adult; Aged; Biomarkers; Blood Coagulation Tests; Case-Control Studies; Extracellular Traps; Female; Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Follow-Up Studies; Histones; Humans; Male; Middle Aged; Plasminogen Activator Inhibitor 1; Prognosis; Pulmonary Embolism; Risk; Sensitivity and Specificity; Thrombin; Thrombosis; Venous Thromboembolism

It has been reported that 476 proteins can be detected in plasma fibrin clots from patients with venous thromboembolism. Plasma fibrin clots proteomic composition in relation to their properties has not been studied in acute pulmonary embolism (PE). Clots generated from plasma of 20 PE patients and 20 healthy controls were assessed using mass spectrometry, clot permeability (K

Topics: Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Humans; Proteomics; Pulmonary Embolism; Thrombosis

Topics: Aged; alpha-2-Antiplasmin; Blood Coagulation; Case-Control Studies; Factor Xa Inhibitors; Factor XIII; Female; Fibrin; Humans; Male; Middle Aged; Pulmonary Embolism; Rivaroxaban; Time Factors; Treatment Outcome

The cutoff values of D-dimer levels for diagnosing or predicting the occurrence of deep vein thrombosis (DVT) were evaluated in preoperative patients and compared to those in non-DVT patients. The levels of 8 different D-dimers were measured using the latex agglutination method or enzyme immunoassay before surgery in 262 orthopedic surgery patients to diagnose subclinical DVT or predict postoperative DVT. There were 15 patients with subclinical DVT and 47 with postoperative DVT, but 200 patients had no DVT at all. All 8 plasma D-dimer values were significantly higher in the patients with subclinical or postoperative DVT than in those without DVT or in healthy volunteers. There were differences in the cutoff values between the assays highly sensitive for low D-dimer levels and wild-range assays of D-dimers. Some D-dimer assays might therefore be more useful than others for diagnosing low levels of D-dimer. Although the measurement of D-dimer levels was useful for diagnosing subclinical DVT and predicting the risk of DVT, the cutoff values for the diagnosis or prediction of DVT varied. The cutoff values for the prediction of postoperative DVT were ≥1.7 µg/mL (D-dimer A-D) and ≥1.0 µg/mL (D-dimer E-H).

Topics: Aged; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Male; Middle Aged; Pulmonary Embolism; Venous Thrombosis

Pulmonary thromboembolic events cause significant morbidity and mortality after severe trauma. Clinically, these lesions are believed to be emboli arising secondary to deep venous thrombosis (DVT) in the lower extremities. Recently, this notion has been challenged by clinical studies, showing that pulmonary clots arise after trauma in the absence of DVT. This suggests that pulmonary blood clots arise in situ via de novo thrombosis. In the present study, we characterize a murine weight-drop model of lateral blunt thoracic trauma. Our model demonstrates severe unilateral lung contusion injury with low (10%) mortality in the absence of extrapulmonary injury, after impact with a 50-g weight dropped from 45 cm height (657 J/m). At 24 h after injury, immunofluorescence and histological evidence revealed early pulmonary arterial thrombosis in the form of eccentric accumulation of fibrin and CD41 positive eosinophilic proteinaceous material, on both coup and contrecoup lung lobes of injured mice, indicating early thrombotic events both within and outside of the area of primary lung injury. Our model is ideal in that lateral impact enables greater impact energy to be applied to achieve significant lung contusion without significant mortality or extrapulmonary injury, and the model has additional translational value in creating thrombosis analogous to pulmonary embolism observed clinically after blunt thoracic trauma. To our knowledge, this is the first demonstration of de novo pulmonary thrombosis in a clinically translational model of blunt thoracic trauma, and supports challenges to current assumptions about the origin of pulmonary blood clots in the wake of severe traumatic injury.

Topics: Animals; Bronchoalveolar Lavage; Disease Models, Animal; Fibrin; Fluorescent Antibody Technique; In Situ Nick-End Labeling; Male; Mice; Mice, Inbred C57BL; Platelet Membrane Glycoprotein IIb; Pulmonary Embolism; Thoracic Injuries; Venous Thrombosis

Objective- Terminal complications of bacterial sepsis include development of disseminated intravascular consumptive coagulopathy. Bacterial constituents, including long-chain polyphosphates (polyP), have been shown to activate the contact pathway of coagulation in plasma. Recent work shows that activation of the contact pathway in flowing whole blood promotes thrombin generation and platelet activation and consumption distal to thrombus formation ex vivo and in vivo. Here, we sought to determine whether presence of long-chain polyP or bacteria in the bloodstream promotes platelet activation and consumption in a coagulation factor (F)XII-dependent manner. Approach and Results- Long-chain polyP promoted platelet P-selectin expression, microaggregate formation, and platelet consumption in flowing whole blood in a contact activation pathway-dependent manner. Moreover, long-chain polyP promoted local fibrin formation on collagen under shear flow in a FXI-dependent manner. Distal to the site of thrombus formation, platelet consumption was dramatically enhanced in the presence of long-chain polyP in the blood flow in a FXI- and FXII-dependent manner. In a murine model, long-chain polyP promoted platelet deposition and fibrin generation in lungs in a FXII-dependent manner. In a nonhuman primate model of bacterial sepsis, pre-treatment of animals with an antibody blocking FXI activation by FXIIa reduced lethal dose

Topics: Animals; Blood Coagulation; Blood Platelets; Disease Models, Animal; Factor XII; Factor XIIa; Female; Fibrin; Humans; Male; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Papio ursinus; Platelet Activation; Polyphosphates; Prekallikrein; Pulmonary Embolism; Sepsis; Signal Transduction; Staphylococcal Infections; Thrombosis; Tissue Kallikreins

Plasminogen (Plg) is a precursor of plasmin that degrades fibrin. A race-specific A620T mutation in Plg, also known as Plg-Tochigi, originally identified in a patient with recurrent venous thromboembolism, causes dysplasminogenemia with reduced plasmin activity. The Plg-A620T mutation is present in 3-4% of individuals in East Asian populations, and as many as 50,000 Japanese are estimated to be homozygous for the mutant 620T allele. In the present study, to understand the changes of thrombotic phenotypes in individuals with the mutant 620T allele, we generated knock-in mice carrying the homozygous Plg-A622T mutation (PlgT/T), an equivalent to the A620T mutation in human Plg. PlgT/T mice grew normally but showed severely reduced plasmin activity activated by urokinase, equivalent to ~8% of that in wild-type mice. In vitro fibrin clot lysis in plasma was significantly slower in PlgT/T mice than in wild-type mice. However, all experimental models of electrolytic deep vein thrombosis, tissue factor-induced pulmonary embolism, transient focal brain ischaemic stroke, or skin-wound healing showed largely similar phenotypes between PlgT/T mice and wild-type mice. Protein S-K196E mutation (Pros1E/E) is a race-specific genetic risk factor for venous thromboembolism. Coexistence in mice of PlgT/T and Pros1E/E did not affect pulmonary embolism symptoms, compared with those in Pros1E/E mice. Hence, the present study showed that the Plg-A622T mutation, which confers ~8% plasmin activity, does not increase the risk of thrombotic diseases in mice under experimental thrombotic conditions and does not modify the thrombotic phenotype observed in Pros1E/E mice. PlgT/T mice can be used to investigate the potential pathophysiological impact of the Plg-A620T mutation.

Topics: Amino Acid Substitution; Animals; Brain Ischemia; Conjunctivitis; Disease Models, Animal; Female; Fibrin; Fibrinolysin; Gene Expression; Gene Knock-In Techniques; Humans; Male; Mice; Mice, Transgenic; Mutation; Phenotype; Plasminogen; Protein S; Pulmonary Embolism; Skin Diseases, Genetic; Stroke; Venous Thromboembolism; Venous Thrombosis; Wound Healing

The aim of this study was to discover small-molecule anticoagulants from Scolopendra subspinipes mutilans (SSM). A new acylated polyamine (1) and a new sulfated quinoline alkaloid (2) were isolated from SSM. Treatment with the new alkaloids 1, 2, and indole acetic acid 4 prolonged the activated partial thromboplastin time and prothrombin time and inhibited the activity and production of thrombin and activated factor X. Furthermore, compounds 1, 2, and 4 inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In accordance with these potential in vitro antiplatelet activities, compounds 1, 2, and 4 showed enhanced antithrombotic effects in an in vivo pulmonary embolism and arterial thrombosis model. Compounds 1, 2, and 4 also elicited anticoagulant effects in mice. Collectively, this study may serve as the groundwork for commercializing SSM or compounds 1, 2, and 4 as functional food components for the prevention and treatment of pathogenic conditions and serve as new scaffolds for the development of anticoagulants.

Topics: Acylation; Alkaloids; Animals; Anticoagulants; Disease Models, Animal; Diterpene Alkaloids; Drug Discovery; Drugs, Chinese Herbal; Factor Xa; Fibrin; Fibrinolytic Agents; Indoleacetic Acids; Male; Mice; Mice, Inbred C57BL; Partial Thromboplastin Time; Platelet Aggregation; Polyamines; Polymerization; Prothrombin Time; Pulmonary Embolism; Quinolines; Thrombin; Thrombosis

Tetanus is a disease characterized by spastic paralysis and spasms. It is a serious pathology that requires treatment in the ICU. Mortality rate is primarily due to neurodegenerative and infectious complications. Thromboembolic complications are rare. To the best of our knowledge, pulmonary embolism has never occorred and been confirmed in patients with generalized tetanus. Our study reports the case of a patient with generalized tetanus complicated by fibrin, cruoric pulmonary embolism.

Topics: Fibrin; Humans; Male; Middle Aged; Pulmonary Embolism; Tetanus

Type I antithrombin deficiency is an autosomal dominant disorder associated with thromboembolic complications mainly related to single-point mutations in SERPINC1, the gene encoding antithrombin. Chromosomal rearrangements have been found in up to 10% of cases with type I antithrombin deficiency. We report here the first heterozygous deletion of SERPINC1 exon 1 identified in a 44-year-old man with type I deficiency who developed deep vein thrombosis of the left leg complicated by pulmonary embolism. This study demonstrates that the search for large gene rearrangements in SERPINC1 can be a useful diagnostic approach, particularly in patients with type I antithrombin deficiency without mutations in SERPINC1.

Topics: Adult; Antithrombin III; Exons; Fibrin; Gene Deletion; Humans; Male; Mutation; Pulmonary Embolism

The diagnosis of deep venous thromboembolic disease is still challenging despite the progress of current thrombus imaging modalities and new diagnostic algorithms. We recently reported the high target uptake and thrombus imaging efficacy of the novel fibrin-specific PET probe (64)Cu-FBP8. Here, we tested the feasibility of (64)Cu-FBP8 PET to detect source thrombi and culprit emboli after deep vein thrombosis and pulmonary embolism (DVT-PE). To support clinical translation of (64)Cu-FBP8, we performed a human dosimetry estimation using time-dependent biodistribution in rats.. Sprague-Dawley rats (n = 7) underwent ferric chloride application on the femoral vein to trigger thrombosis. Pulmonary embolism was induced 30 min or 2 d after DVT by intrajugular injection of a preformed blood clot labeled with (125)I-fibrinogen. PET imaging was performed to detect the clots, and SPECT was used to confirm in vivo the location of the pulmonary emboli. Ex vivo γ counting and histopathology were used to validate the imaging findings. Detailed biodistribution was performed in healthy rats (n = 30) at different time points after (64)Cu-FBP8 administration to estimate human radiation dosimetry. Longitudinal whole-body PET/MR imaging (n = 2) was performed after (64)Cu-FBP8 administration to further assess radioactivity clearance.. (64)Cu-FBP8 PET imaging detected the location of lung emboli and venous thrombi after DVT-PE, revealing significant differences in uptake between target and background tissues (P < 0.001). In vivo SPECT imaging and ex vivo γ counting confirmed the location of the lung emboli. PET quantification of the venous thrombi revealed that probe uptake was greater in younger clots than in older ones, a result confirmed by ex vivo analyses (P < 0.001). Histopathology revealed an age-dependent reduction of thrombus fibrin content (P = 0.006), further supporting the imaging findings. Biodistribution and whole-body PET/MR imaging showed a rapid, primarily renal, body clearance of (64)Cu-FBP8. The effective dose was 0.021 mSv/MBq for males and 0.027 mSv/MBq for females, supporting the feasibility of using (64)Cu-FBP8 in human trials.. We showed that (64)Cu-FBP8 PET is a feasible approach to image DVT-PE and that radiogenic adverse health effects should not limit the clinical translation of (64)Cu-FBP8.

Topics: Algorithms; Animals; Copper Radioisotopes; Female; Fibrin; Male; Positron-Emission Tomography; Pulmonary Embolism; Radiometry; Rats; Rats, Sprague-Dawley; Thrombosis; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Venous Thrombosis; Whole Body Imaging

Cancer is a leading cause of thrombosis. We identify a new procoagulant mechanism that contributes to thromboembolism in prostate cancer and allows for safe anticoagulation therapy development. Prostate cancer-mediated procoagulant activity was reduced in plasma in the absence of factor XII or its substrate of the intrinsic coagulation pathway factor XI. Prostate cancer cells and secreted prostasomes expose long chain polyphosphate on their surface that colocalized with active factor XII and initiated coagulation in a factor XII-dependent manner. Polyphosphate content correlated with the procoagulant activity of prostasomes. Inherited deficiency in factor XI or XII or high-molecular-weight kininogen, but not plasma kallikrein, protected mice from prostasome-induced lethal pulmonary embolism. Targeting polyphosphate or factor XII conferred resistance to prostate cancer-driven thrombosis in mice, without increasing bleeding. Inhibition of factor XII with recombinant 3F7 antibody reduced the increased prostasome-mediated procoagulant activity in patient plasma. The data illustrate a critical role for polyphosphate/factor XII-triggered coagulation in prostate cancer-associated thrombosis with implications for anticoagulation without therapy-associated bleeding in malignancies.

Topics: Animals; Antibodies, Monoclonal, Humanized; Cell Line, Tumor; Factor XII; Factor XIIa; Fibrin; Humans; Male; Mice; Polyphosphates; Prostatic Neoplasms; Pulmonary Embolism; Secretory Vesicles; Thrombin; Thrombosis

The factors that contribute to pulmonary embolism (PE), a potentially fatal complication of deep vein thrombosis (DVT), remain poorly understood. Whereas fibrin clot structure and functional properties have been implicated in the pathology of venous thromboembolism and the risk for cardiovascular complications, their significance in PE remains uncertain. Therefore, we systematically compared and quantified clot formation and lysis time, plasminogen levels, viscoelastic properties, activated factor XIII cross-linking, and fibrin clot structure in isolated DVT and PE subjects. Clots made from plasma of PE subjects showed faster clot lysis times with no differences in lag time, rate of clot formation, or maximum absorbance of turbidity compared with DVT. Differences in lysis times were not due to alterations in plasminogen levels. Compared with DVT, clots derived from PE subjects showed accelerated establishment of viscoelastic properties, documented by a decrease in lag time and an increase in the rate of viscoelastic property formation. The rate and extent of fibrin cross-linking by activated factor XIII were similar between clots from DVT and PE subjects. Electron microscopy revealed that plasma fibrin clots from PE subjects exhibited lower fiber density compared with those from DVT subjects. These data suggest that clot structure and functional properties differ between DVT and PE subjects and provide insights into mechanisms that may regulate embolization.

Topics: Adult; Aged; Blood Coagulation; Cross-Linking Reagents; Elasticity; Factor XIIIa; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Plasminogen; Prospective Studies; Pulmonary Embolism; Venous Thrombosis

A thrombolytic protease named kitamase possessing anticoagulant property was purified from edible and medicinal plant Aster yomena (Kitam.) Honda. Kitamase showed a molecular weight of 50 kDa by SDS-PAGE and displayed a strong fibrin zymogram lysis band corresponding to the similar molecular mass. The enzyme was active at high temperatures (50°C). The fibrinolytic activity of kitamase was strongly inhibited by EDTA, EGTA, TPCK and PMSF, inhibited by Zn(2+). The Km and Vmax values for substrate S-2251 were determined as 4.31 mM and 23.81 mM/mg respectively. It dissolved fibrin clot directly and specifically cleaved the α, Aα and γ-γ chains of fibrin and fibrinogen. In addition, kitamase delayed the coagulation time and increased activated partial thromboplastin time and prothrombin time. Kitamase exerted a significant protective effect against collagen and epinephrine induced pulmonary thromboembolism in mice. These results suggest that kitamase may have the property of metallo-protease like enzyme, novel fibrino(geno)lytic enzyme and a potential to be a therapeutic agent for thrombosis.

Topics: Animals; Aster Plant; Blood Coagulation Tests; Cations, Divalent; Collagen; Edetic Acid; Egtazic Acid; Endopeptidases; Fibrin; Fibrinogen; Fibrinolysis; Fibrinolytic Agents; Hot Temperature; Kinetics; Male; Mice; Mice, Inbred ICR; Molecular Weight; Plant Leaves; Plant Proteins; Plants, Medicinal; Pulmonary Embolism; Zinc

Chronic thromboembolic pulmonary hypertension (CTEPH) is a fatal disease that is distinct from pulmonary arterial hypertension (PAH). Although CTEPH is characterized by obstruction of major pulmonary artery because of chronic thrombus, it remains unclear whether CTEPH is associated with prothrombotic condition.. In addition to conventional markers, GTP-bound levels of Rap1, RhoA, RalA, Rac1, and Ras in platelets, which are implicated for platelet activation, were measured in patients without pulmonary hypertension (non-PH, n=15), patients with PAH (n=19), and patients with CTEPH (n=25). Furthermore, the responsiveness to ex vivo thrombin stimulation was also evaluated. The ratios of the P-selectin positive platelets in the non-PH patients, patients with PAH, and patients with CTEPH were 1.40% (median and interquartile range, 0.83-1.82), 2.40% (1.80-3.39), and 2.63% (1.90-8.22), respectively (non-PH versus CTEPH, P<0.01). The activated GPIIb/IIIa-positive platelets were 6.01% (1.34-7.87), 11.39% (5.69-20.86), and 9.74% (7.83-24.01), respectively (non-PH versus CTEPH, P=0.01). GTP-bound RhoA was 1.79% (0.94-2.83), 4.03% (2.01-5.14), and 2.01% (1.22-2.48), respectively (non-PH versus PAH, P=0.04), and GTP-bound RalA was 1.58% (1.08-2.11), 3.02% (2.03-3.54), and 2.64% (1.42-4.28), respectively (non-PH versus PAH, P=0.023; non-PH versus CTEPH, P=0.048). In contrast, Rac1, Rap1, or Ras was not activated in any groups. The platelets of patients with CTEPH exhibited hyperresponsiveness to ex vivo thrombin stimulation compared with those of non-PH patients when evaluated for the surface markers. Either D-dimer or fibrin degradation product level was not increased in patients with CTEPH.. These results provide the first direct evidence that platelets of patients with CTEPH are highly activated and exhibit hyperresponsiveness to thrombin stimulation.

Topics: Adult; Aged; Blood Platelets; Case-Control Studies; Chronic Disease; Female; Fibrin; Hemodynamics; Humans; Hypertension, Pulmonary; Male; Middle Aged; P-Selectin; Platelet Activation; Platelet Glycoprotein GPIIb-IIIa Complex; Pulmonary Embolism; ral GTP-Binding Proteins; Regression Analysis; rhoA GTP-Binding Protein; Thrombin

The α(1,3)-fucosyltransferases, types IV and VII (FUT4 and FUT7, respectively), are required for the synthesis of functional selectin-type leukocyte adhesion molecule ligands. The selectins and their ligands modulate leukocyte trafficking, and P-selectin and its ligand, P-selectin glycoprotein ligand-1, can modulate hemostasis and thrombosis. Regulation of thrombosis by FUT4 and/or FUT7 activity was examined in mouse models of carotid artery thrombosis and collagen/epinephrine-induced thromboembolism. Mice lacking both FUT4 and FUT7 (Fut(-/-) mice) had a shorter time to occlusive thrombus formation in the injured carotid artery and a higher mortality due to collagen/epinephrine-induced pulmonary thromboemboli. Mice lacking P-selectin or P-selectin glycoprotein ligand-1 did not have a prothrombotic phenotype. Whole blood platelet aggregation was enhanced, and plasma fibrinogen content, clot weight, and clot strength were increased in Fut(-/-) mice, and in vitro clot lysis was reduced compared with wild type. Fut4(-/-), but not Fut7(-/-), mice had increased pulmonary thromboembolism-induced mortality and decreased thromboemboli dissolution in vivo. These data show that FUT4 and FUT7 activity regulates thrombosis in a P-selectin- and P-selectin glycoprotein ligand-1-independent manner and suggest that FUT4 activity is important for thrombolysis.

Topics: Animals; Blood Coagulation; Carotid Artery Thrombosis; Disease Susceptibility; Fibrin; Fibrinogen; Fibrinolysis; Fucosyltransferases; Kaplan-Meier Estimate; Mice; Mice, Knockout; Partial Thromboplastin Time; Platelet Aggregation; Prothrombin Time; Pulmonary Embolism; Thrombin; Time Factors

Polymorphisms are associated with chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary thromboembolism (PTE), but no polymorphism specific to CTEPH but not PTE has yet been reported. Fibrin resistance is associated with CTEPH, but the mechanism has not been elucidated.. Polymorphisms were analyzed in 101 CTEPH subjects, 102 PTE subjects and 108 healthy controls by Massarray or restriction fragment length polymorphism (RFLP). Plasmin-mediated cleavage of fibrin was characterized in 69 subjects (29 with CTEPH, 21 with PTE and 19 controls).. Genotype frequencies and allele frequencies of fibrinogen Aα Thr312Ala were significantly higher in CTEPH subjects than in controls and PTE subjects, while there was no difference between PTE subjects and controls. The odd ratio (OR 2.037) and 95% confidence interval (95% CI, 1.262-3.289) showed that Thr312Ala polymorphism was a risk factor for CTEPH but not PTE. Fibrin from CTEPH subjects was more resistant to lysis than that from PTE subjects and controls. Fibrin resistance was significantly different between Aα Thr312Ala (A/G) genotypes within CTEPH subjects, and the fibrin with GG genotype was more resistant than that with AA and AG genotype.. Fibrinogen Aα Thr312Ala (A/G) polymorphism was associated with CTEPH, but not PTE, suggesting that the fibrinogen Aα Thr312Ala polymorphism may act as a potential biomarker in identifying CTEPH from PTE. GG genotype polymorphism contributes to CTEPH through increasing fibrin resistance, implying that PTE subjects with fibrinogen Aα GG genotype may need long-term anticoagulation therapy.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Chronic Disease; Female; Fibrin; Fibrinogen; Fibrinolysis; Gene Frequency; Genotype; Humans; Hypertension, Pulmonary; Male; Middle Aged; Polymorphism, Single Nucleotide; Pulmonary Embolism; Young Adult

Tissue-type plasminogen activator (tPA) remains the sole thrombolytic approved by the FDA for the treatment of pulmonary embolism (PE). tPA has not been replaced by third generation plasminogen activators, e.g. Reteplase (Ret) and Tenecteplase (TNK) that circulate with longer life-spans and in theory should have more extended potency in vivo. One reason for this paradox is the inability to assign units of activity to plasminogen activators based on specific biologically relevant standards, which impairs objective comparison. Here, we compare clot permeation, retention and fibrinolytic activities of tPA, TNK and Ret in vitro and clot composition over time with outcome in a mouse model of disseminated pulmonary microembolism (ME). When clots were incubated in the continuous presence of drug, tPA, TNK and Ret lysed fibrin clots identically in the absence of PA inhibitor-1 (e.g. PAI-1). Ret, which has lower fibrin affinity and greater susceptibility to inhibition by PAI-1 than tPA, was less effective in lysing plasma clots, while TNK was less effective when the fibrin content of the clots was enhanced. However, when clots were afforded only brief exposure to drug, as occurs in vivo, Ret showed more extensive clot permeation, greater retention and lysis than tPA or TNK. These results were reproduced in vivo in a mouse model of ME. These studies indicate the need for more relevant tests of plasminogen activator activity in vitro and in vivo and they show that clot permeation and retention are important potential predictors of clinical utility.

Topics: Animals; Cattle; Diffusion; Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Humans; Kinetics; Lung; Mice; Mice, Inbred C57BL; Plasminogen Activator Inhibitor 1; Plasminogen Activators; Pulmonary Embolism; Recombinant Proteins; Solubility; Tenecteplase; Tissue Plasminogen Activator

Topics: Aged; Anticoagulants; Antifibrinolytic Agents; Blood Coagulation Tests; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male; Middle Aged; Pulmonary Embolism; Risk Factors; Venous Thrombosis

Hereditary antithrombin (AT) deficiency is a rare autosomal disease. More than 200 mutations have been described in the AT gene leading to its deficiency. We describe here a case of type I AT deficiency in a 26-year-old Polish man who experienced proximal deep vein thrombosis and pulmonary embolism associated with a transient thrombotic risk factor, the right ankle trauma, despite the use of low-molecular-weight heparin prophylaxis. The family history was negative for venous thromboembolism. The AT activity was initially 47% and on repeated analysis 53%, and the antigen level, 0.15 g/l. The analysis of AT gene revealed the presence at the heterozygous state of a substitution G more than T located at the first nucleotide 3' of exon 3a (c.624 + 1 G > T, Human Genome Variation Society numbering system). The substitution might be detrimental taking account for its position in a donor splice site. To the best of our knowledge this mutation has not been previously described, so it was named antithrombin Krakow II.

Topics: Adult; Anticoagulants; Exons; Fibrin; Heparin, Low-Molecular-Weight; Heterozygote; Humans; Male; Mutation; Pulmonary Embolism; Venous Thrombosis; White People

Most patients with malignant diseases are frequently complicated with some type of thrombosis, such as disseminated intravascular coagulation (DIC) or deep vein thrombosis (DVT)/pulmonary embolism (PE).. The cohort and retrospective study was designed to examine the frequency of thrombosis in patients with malignant diseases and to evaluate the efficacy of D-dimer and soluble fibrin (SF) for the diagnosis of thrombosis.. The plasma concentrations of D-dimer and SF were measured in patients with malignant diseases suspected of having thrombosis. D-dimer and SF were measured using a latex aggregation assay.. Thrombosis was observed in 23.3% of the patients with malignant diseases. Disseminated intravascular coagulation was frequently observed in patients with hepatoma, and DVT/PE was frequently observed in patients with colon cancer, lung cancer, and uterine cancer. The plasma levels of D-dimer and SF were increased in malignant diseases, especially hepatoma. Plasma levels of D-dimer and SF were significantly higher in patients with thrombosis in comparison to patients without thrombosis. A receiver operating characteristic (ROC) analysis showed the D-dimer and SF levels to be useful in the diagnosis of thrombosis.. Elevated D-dimer and SF levels might indicate a high risk of thrombosis in patients with malignant disease; however, these assays still need to be standardized.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Cohort Studies; Disseminated Intravascular Coagulation; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Neoplasms; Predictive Value of Tests; Pulmonary Embolism; Retrospective Studies; ROC Curve; Thrombophilia; Venous Thrombosis; Young Adult

Reportedly, fibrin isolated from patients with chronic thromboembolic pulmonary hypertension (CTEPH) is resistant to lysis. Persistence of regions within the fibrin beta chain, which mediate cell signaling and migration, could trigger the organization of pulmonary thromboemboli into chronic intravascular scars.. Ascertain whether fibrin resistance to lysis occurs in patients with pulmonary hypertension (PAH) other than CTEPH, and in those with prior pulmonary embolism (PE) and no pulmonary hypertension.. Fibrinogen was purified from 96 subjects (17 with CTEPH, 14 with PAH, 39 with prior PE, and 26 healthy control subjects) and exposed to thrombin to obtain fibrin clots. Plasmin-mediated cleavage of fibrin beta chain was assessed hourly over a 6-hour period by polyacrylamide gel electrophoresis. Fibrin band intensity was measured by densitometry of stained gels. Data were normalized to the band intensity of the undigested protein.. By 1 hour of digestion, fibrin band intensity had decreased by a median of 25% (interquartile range [IQR], 20 to 27%) in control subjects, and by 15% (IQR, 11 to 18%) in patients with prior PE (P < 0.0001). The 1-hour median reduction in band intensity was 2% (IQR, 1 to 3%) in CTEPH, and 4% (IQR, 2 to 7%) in PAH (P < 0.0001 vs. control subjects and PE). The decline in fibrin band intensity remained significantly different among the four groups up to 6 hours (P < 0.0001).. Fibrin resistance to lysis occurs in pulmonary hypertension other than CTEPH and, to a smaller extent, in patients with prior PE and no pulmonary hypertension.

Topics: Adult; Blood Protein Electrophoresis; Echocardiography; Electrophoresis, Polyacrylamide Gel; Female; Fibrin; Fibrinolysis; Hemodynamics; Humans; Hypertension, Pulmonary; Male; Middle Aged; Pulmonary Embolism

To explore the effect(s) of growth hormone signaling on thrombosis, we studied signal transduction and transcription factor 5 (STAT5)-deficient mice and found markedly reduced survival in an in vivo thrombosis model. These findings were not explained by a compensatory increase in growth hormone secretion. There was a modest increase in the activity of several procoagulant factors, but there was no difference in the rate or magnitude of thrombin generation in STAT5-deficient mice relative to control. However, thrombin-triggered clot times were markedly shorter, and fibrin polymerization occurred more rapidly in plasma from STAT5-deficient mice. Fibrinogen depletion and mixing studies indicated that the effect on fibrin polymerization was not due to intrinsic changes in fibrinogen, but resulted from changes in the concentration of a circulating plasma inhibitor. While thrombin-triggered clot times were significantly shorter in STAT5-deficient animals, reptilase-triggered clot times were unchanged. Accordingly, while the rate of thrombin-catalyzed release of fibrinopeptide A was similar, the release of fibrinopeptide B was accelerated in STAT5-deficient plasma versus control. Taken together, these studies demonstrated that the loss of STAT5 resulted in a decrease in the concentration of a plasma inhibitor affecting thrombin-triggered cleavage of fibrinopeptide B. This ultimately resulted in accelerated fibrin polymerization and greater thrombosis susceptibility in STAT5-deficient animals.

Topics: Animals; Blood Coagulation; Disease Models, Animal; Factor XIII; Fibrin; Fibrinopeptide B; Immunoblotting; Mice; Mice, Inbred C57BL; Mice, Knockout; Pulmonary Embolism; Signal Transduction; STAT5 Transcription Factor; Thrombin Time; Thrombosis

Acute pulmonary embolism occurs in more than half a million people a year in the United States. Chronic thromboembolic pulmonary hypertension (CTEPH) develops in approximately 4% of these patients due to unresolved thromboemboli. CTEPH is thus a relatively common, progressive, and potentially fatal disease. One currently proposed theory for the poor resolution advocates that modification of fibrinogen in CTEPH patients causes resistance of emboli to fibrinolysis. The current study investigated the regulation of cytosolic Ca(2+) ([Ca(2+)](cyt)), central to the control of cell migration, proliferation, and contraction, by chronic exposure of pulmonary artery smooth muscle (PASMC) and endothelial (PAEC) cells to fibrinogen and fibrin. Basal [Ca(2+)](cyt) was substantially elevated in PAEC after culture on fibrinogen, fibrin, and thrombin and in PASMC on fibrinogen and fibrin. In PAEC, fibrinogen significantly decreased the peak [Ca(2+)](cyt) transient (P <0.001) without a change in the transient peak width (at 50% of the peak height). This response was independent of effects on the proteinase-activated receptor (PAR) 1. Furthermore, chronic exposure to thrombin, an activator of PAR, significantly reduced the peak agonist-induced Ca(2+) release in PAEC, but increased it in PASMC. The recovery rate of the agonist-induced [Ca(2+)](cyt) transients decelerated in PASMC chronically exposed to fibrin; a small increase of the peak Ca(2+) was also observed. Substantial augmentation of PASMC (but not PAEC) proliferation was observed in response to chronic fibrin exposure. In conclusion, chronic exposure to fibrinogen, fibrin, and thrombin caused differential changes in [Ca(2+)](cyt) in PAEC and PASMC. Such changes in [Ca(2+)](cyt) may contribute to vascular changes in patients who have CTEPH where the pulmonary vasculature is persistently exposed to thromboemboli.

Topics: Boron Compounds; Calcium; Calcium Signaling; Cell Division; Cells, Cultured; Endothelial Cells; Fibrin; Fibrinogen; Humans; Lanthanum; Muscle, Smooth, Vascular; Oligopeptides; Pulmonary Artery; Pulmonary Embolism; Receptor, PAR-1; Thrombin

The mechanism by which chronic thromboembolic pulmonary hypertension (CTEPH) develops after acute pulmonary thromboembolism is unknown. We previously reported that fibrin from CTEPH patients is relatively resistant to fibrinolysis in vitro. In the present study, we performed proteomic, genomic, and functional studies on fibrin(ogen) to investigate whether abnormal fibrin(ogen) might contribute to the pathogenesis of CTEPH. Reduced and denatured fibrinogen from 33 CTEPH patients was subjected to liquid chromatography-mass spectrometry analysis. Fibrinogen from 21 healthy controls was used to distinguish atypical from commonly occurring mass peaks. Atypical peaks were further investigated by targeted genomic DNA sequencing. Five fibrinogen variants with corresponding heterozygous gene mutations (dysfibrinogenemias) were observed in 5 of 33 CTEPH patients: Bbeta P235L/gamma R375W, Bbeta P235L/gamma Y114H, Bbeta P235L, Aalpha L69H, and Aalpha R554H (fibrinogens(San Diego I-V)). Bbeta P235L was found in 3 unrelated CTEPH patients. Functional analysis disclosed abnormalities in fibrin polymer structure and/or lysis with all CTEPH-associated mutations. These results suggest that, in some patients, differences in the molecular structure of fibrin may be implicated in the development of CTEPH after acute thromboembolism.

Topics: Adult; Aged; Blood Coagulation Disorders, Inherited; DNA Mutational Analysis; Female; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Humans; Hypertension, Pulmonary; Male; Middle Aged; Mutation; Polymorphism, Genetic; Prevalence; Pulmonary Embolism

We aimed to investigate whether early thrombus formation can be visualized with in vivo magnetic resonance imaging (MRI) by the use of a novel bimodal alpha(2)-antiplasmin-based contrast agent (CA).. Thrombus formation plays a central role in several vascular diseases. During the early phases of thrombus formation, activated factor XIII (FXIIIa) covalently cross-links alpha(2)-antiplasmin to fibrin, indicating the potential of alpha(2)-antiplasmin-based CAs in the detection of early thrombus formation.. A bimodal CA was synthesized by coupling gadolinium-diethylene triamine pentaacetic acid and rhodamine to an alpha(2)-antiplasmin-based peptide. For the control CA, a glutamine residue essential for cross-linking was replaced by alanine. In vitro-generated thrombi were exposed to both CAs and imaged by MRI and 2-photon laser-scanning microscopy. Immunohistochemistry was performed on human pulmonary thromboemboli sections to determine the presence of alpha(2)-antiplasmin and FXIII in different thrombus remodeling phases. In vivo feasibility of the CA in detecting early thrombus formation specifically was investigated with MRI.. In vitro-generated thrombi exposed to the alpha(2)-antiplasmin-based CA showed hyperintense magnetic resonance signal intensities at the thrombus edge. No hyperintense signal was observed when we used the alpha(2)-antiplasmin-based CA in the presence of FXIII inhibitor dansylcadaverine nor when we used the control CA. Two-photon laser-scanning microscopy demonstrated that the alpha(2)-antiplasmin-based CA bound to fibrin. Immunohistochemistry demonstrated substantial alpha(2)-antiplasmin staining in fresh compared with lytic and organized thrombi. The administration of CA in vivo within seconds after inducing thrombus formation increased contrast-to-noise ratios (CNRs 2.28 +/- 0.39, n=6) at the site of thrombus formation compared with the control CA (CNRs -0.14 +/- 0.55, p = 0.003, n = 6) and alpha(2)-antiplasmin-based CA administration 24 to 48 h after thrombus formation (CNRs 0.11 +/- 0.23, p = 0.006, n = 6).. A bimodal CA was developed, characterized, and validated. Our results showed that this bimodal CA enabled noninvasive in vivo magnetic resonance visualization of early thrombus formation.

Topics: alpha-2-Antiplasmin; Animals; Cadaverine; Contrast Media; Disease Models, Animal; Factor XIII; Factor XIIIa; Feasibility Studies; Fibrin; Gadolinium DTPA; Humans; Immunohistochemistry; Magnetic Resonance Imaging; Mice; Microscopy, Fluorescence, Multiphoton; Predictive Value of Tests; Pulmonary Embolism; Reproducibility of Results; Rhodamines; Thrombosis

We tested the hypothesis that fibrin structure/function is unfavorably altered in patients after idiopathic venous thromboembolism (VTE) and their relatives. Ex vivo plasma fibrin clot permeability, turbidimetry, and efficiency of fibrinolysis were investigated in 100 patients with first-ever VTE, including 34 with pulmonary embolism (PE), 100 first-degree relatives, and 100 asymptomatic controls with no history of thrombotic events. Known thrombophilia, cancer, trauma, and surgery were exclusion criteria. VTE patients and their relatives were characterized by lower clot permeability (P < .001), lower compaction (P < .001), higher maximum clot absorbancy (P < .001), and prolonged clot lysis time (P < .001) than controls, with more pronounced abnormalities, except maximum clot absorbance, in the patients versus relatives (all P < .01). Fibrin clots obtained for PE patients were more permeable, less compact, and were lysed more efficiently compared with deep-vein thrombosis patients (all P < .05) with no differences in their relatives. Being VTE relative, fibrinogen, and C-reactive protein were independent predictors of clot permeability and fibrinolysis time in combined analysis of controls and relatives. We conclude that altered fibrin clot features are associated with idiopathic VTE with a different profile of fibrin variables in PE. Similar features can be detected in VTE relatives. Fibrin properties might represent novel risk factors for thrombosis.

Topics: Adolescent; Adult; Aged; Blood Coagulation; Blood Coagulation Tests; Case-Control Studies; Factor XIII; Female; Fibrin; Fibrinogen; Fibrinolysis; Genotype; Humans; In Vitro Techniques; Male; Middle Aged; Nephelometry and Turbidimetry; Pulmonary Embolism; Risk Factors; Venous Thromboembolism; Young Adult

Congenital dysfibrinogenemia is a rare disease characterised by inherited abnormality in the fibrinogen molecule, resulting in functional defects. Two patients, a 26-year-old woman and a 61-year-old man, both with history of thrombotic events, had abnormal coagulation test results. DNA sequencing showed the heterozygous gamma Y363N mutation (Fibrinogen Praha III) and the heterozygous Aalpha N106D mutation (Fibrinogen Plzen), respectively. Fibrin polymerisation, after addition of either thrombin or reptilase, showed remarkably delayed polymerisation in both cases. Fibrinolysis experiments showed slower tPA initiated lysis of clots. SDS-PAGE did not show any difference between normal and Praha III and Plzen fibrinogens. Both mutations had a significant effect on platelet aggregation. In the presence of either ADP or TRAP, both mutations caused the decrease of platelet aggregation. SEM revealed abnormal clot morphology, with a large number of free ends and narrower fibres of both fibrin Praha III and Plzen. Praha III mutation was situated in the polymerisation pocket "a". The replacement of the bulky aromatic side chain of tyrosine by the polar uncharged small side chain of asparagine may lead to a conformational change, possibly altering the conformation of the polymerisation pocket. The Plzen mutation is situated in the coiled-coil connector and this replacement of polar uncharged asparagine residue by polar acidic aspartate changes the alpha-helical conformation of the coiled-coil connector; and may destabilise hydrogen bonds in its neighborhood. Although both mutations are situated in different regions of the molecule, both mutations have a very similar effect on fibrinogen functions and both are connected with thromboses.

Topics: Adult; Blood Coagulation; Coagulation Protein Disorders; Female; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Mutation; Platelet Aggregation; Pulmonary Embolism; Thrombosis

To enable outpatient treatment of a selected group of patients with pulmonary embolism (PE), insight in the determinants of adverse clinical outcome is warranted. We have identified risk factors for serious adverse events (SAE) within the first 10 days of acute PE. We have retrospectively analysed data of 440 consecutive patients with acute PE. Collected data included age, gender, medical history, blood pressure, pulse rate and D-dimer concentration. The variables associated with SAE in the first 10 days in univariate analysis (p<0.15) have been included in a multivariate logistic regression model (backward conditional, p out >0.10). In 440 patients with acute PE, 20 SAEs occurred in a 10-day follow-up period. Pulse rate > or = 100 beats per minute (bpm) (OR, 6.85; 95%CI 1.43-32.81) and D-dimer concentration > or = 3,000 microg/ml (OR, 5.51; 95%CI 0.68-44.64) were significantly related to the SAEs. All SAEs were predicted by a pulse rate > or = 100 bpm and/or a D-dimer concentration > or = 3,000 microg/ml. Older age, gender, history of venous thromboembolism (VTE), heart failure, chronic obstructive pulmonary disease, cancer or a systolic blood pressure < 90 mm Hg had no significant influence on short term SAEs. Pulse rate and D-dimer concentration can be used to identify patients with acute PE, who are at risk for adverse clinical outcome during the first 10 days of hospitalisation. Outpatient treatment of PE-patients with a pulse rate > or = 100 bpm and/or a D-dimer concentration > or = 3,000 microg/ml has to be discouraged.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Disease Progression; Female; Fibrin; Follow-Up Studies; Heart Rate; Humans; Male; Middle Aged; Netherlands; Predictive Value of Tests; Pulmonary Embolism; Retrospective Studies; Risk Factors; Sensitivity and Specificity

Molecular targeted MR imaging of human clots material in a model of pulmonary embolism using a fibrin-specific magnetic resonance imaging contrast agent (EP-2104R, EPIX Pharmaceuticals, Cambridge, MA).. Fresh ex vivo engineered thrombi (human blood) and human clots removed from patients were delivered in 11 swine. Molecular MR imaging with a 3D gradient-echo [3D fast field echo (3DFFE)] sequence and a navigator-gated and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence (IR) was performed before thrombus delivery, after thrombus delivery but before contrast media application, and 2 hours after i.v. administration of 4 micromol/kg EP-2104R. MR images were analyzed by 2 investigators and contrast-to-noise ratio (CNR) was assessed. Thrombi were removed for assessment of gadolinium (Gd) concentration.. Only after contrast media application were pulmonary emboli [freshly engineered thrombi (n = 23) and human clot material removed from patients (n = 25)] visualized as white foci on MR images. CNR was 13 +/- 3 (ex vivo engineered clot) and 22 +/- 9 (patient clot material) for the fast field echo (FFE)-sequence and 29 +/- 9 (ex vivo engineered clot) and 43 +/- 18 (patient clot material) for the IR-sequence, respectively. A high Gd concentration in the clots was found (82 +/- 43 microM for the freshly engineered and 247 +/- 44 microM for the clots removed from patients, respectively).. EP-2104R allows for molecular MR imaging of human clot material in the pulmonary vessels of a swine model.

Topics: Animals; Contrast Media; Disease Models, Animal; Fibrin; Gadolinium; Humans; Magnetic Resonance Imaging; Molecular Structure; Peptides; Protein Binding; Pulmonary Embolism; Swine

Plasminogen activators (PAs; e.g., tissue-type, tPA) coupled to red blood cells (RBCs) display in vivo features useful for thromboprophylaxis: prolonged circulation, minimal extravasation, and preferential lysis of nascent versus preexisting clots. Yet, factors controlling the activity of RBC-bound PAs in vivo are not defined and may not mirror the profile of soluble PAs. We tested the role of RBC/PA binding to fibrin in fibrinolysis. RBC/tPA and RBC/tPA variant with low fibrin affinity (rPA) bound to and lysed plasminogen-containing fibrin clots in vitro comparably. In contrast, when coinjected in mice with fibrin emboli lodging in pulmonary vasculature, only RBC/tPA accumulated in lungs, which resulted in a more extensive fibrinolysis versus RBC/rPA (p < 0.01). Reconciling this apparent divergence between in vitro and in vivo behaviors, RBC/tPA, but not RBC/rPA perfused over fibrin in vitro at physiological shear stress bound to fibrin clots and caused greater fibrinolysis versus RBC/rPA (p < 0.001). These results indicate that because of high fibrin affinity, RBC/tPA binding to clots endures hemodynamic stress, which enhances fibrinolysis. Behavior of RBC/PAs under hemodynamic pressure is an important predictor of their performance in vivo.

Topics: Animals; Erythrocytes; Fibrin; Fibrinolysis; Hemodynamics; Humans; Male; Mice; Mice, Inbred C57BL; Protein Binding; Pulmonary Embolism; Tissue Plasminogen Activator

A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for alpha-chain-fibrin was labeled with (99m)Tc ((99m)Tc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE).. Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. (99m)Tc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, (99m)Tc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue.. The affinity for human fibrin was 10(-9) mol/L and there were >10(15) receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9-22.6), DVT/muscle (31.1-89.4), PE/blood (1-155), and PE/lung (0.8-245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the gamma-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms.. (99m)Tc-TP850 with its modest affinity (10(-9) mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis.

Topics: Animals; Fibrin; Metabolic Clearance Rate; Oligopeptides; Organ Specificity; Organotechnetium Compounds; Pulmonary Embolism; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Swine; Tissue Distribution; Venous Thrombosis

Although acute pulmonary embolism is epidemiologically associated with chronic thromboembolic pulmonary hypertension, the factors responsible for resistance to thrombolysis and a shift toward vascular remodeling within the pulmonary arteries of patients with chronic thromboembolic pulmonary hypertension are unknown.. Determine whether fibrin from patients is more resistant to plasmin-mediated lysis than fibrin from healthy control subjects.. Fibrinogen purified from patients and control subjects was used to prepare fibrin clots, which were subsequently digested with plasmin for various periods of time. The degradation of the alpha-, beta-, and gamma-chains of fibrin and the appearance of peptide fragments over time were assessed by polyacrylamide gel electrophoresis and Western blotting.. Densitometry of Coomassie-stained gels revealed significantly slower cleavage of all three polypeptide chains of fibrin from patients compared with control subjects (p < 0.05). In particular, release of N-terminal fragments from the beta-chain of fibrin, which promote cell signaling, cell migration, and angiogenesis, was retarded in patients compared with control subjects (p < 0.01).. The relative resistance of patient fibrin to plasmin-mediated lysis may be due to alterations in fibrin(ogen) structure affecting accessibility to plasmin cleavage sites. The persistence of structural motifs of fibrin, such as the beta-chain N-terminus, within the pulmonary vasculature could promote the transition from acute thromboemboli into chronic obstructive vascular scars.

Topics: Adult; Aged; alpha-2-Antiplasmin; Case-Control Studies; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysin; Fibrinolysis; Fibrinolytic Agents; Humans; Hypertension, Pulmonary; Male; Middle Aged; Plasminogen; Pulmonary Embolism; Thrombolytic Therapy

Topics: Adult; Blood Coagulation; Contraceptives, Oral, Combined; Contraceptives, Oral, Synthetic; Desogestrel; Estrogens; Ethinyl Estradiol; Exercise; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Protein C; Pulmonary Embolism

Deep venous thrombosis and pulmonary thromboembolism are common within weeks of spinal cord injury (SCI) but clinically uncommon in the chronically paralyzed. Fibrinogen half-life (FHL) and fibrin uptake of the legs (FUT), as indicators of an active thrombotic process, have been used to test this clinical impression.. Data from the use of autologous preparations of radioiodinated fibrinogen to determine FHL and FUT in 17 men paralyzed at cervical (6), thoracic (10), and lumbar levels (1), at ASIA grades A (15) and C (2) in 1974 to 1976 were reviewed. Group A consisted of 12 subjects 29 +/- 8 years of age and paralyzed 1 week to 5 months (median, 1 month). Group B consisted of 5 subjects 46 +/- 17 years of age and paralyzed 24 to 96 months (median, 36 months). Group B subjects were older and paralyzed longer than Group A. Group C consisted of 4 able-bodied control subjects enrolled at the same time for FHL studies, and these subjects were 34 to 38 years of age.. FHL was 61 +/- 14 hours for all SCI subjects and 95 +/- 23 hours for Group C (P = 0.001). Group A FHL was 59 +/- 16 hours, and FUT was positive in 8 of 12 subjects. Group B FHL was 66 +/- 7 hours, and FUT was positive in 3 of 4 subjects (1 FUT not done; P = 0.30 and 1.0, respectively).. Fibrinogen metabolism was abnormal in patients with acute SCI at high risk for pulmonary thromboembolism (PE) but continued to be abnormal beyond the high risk period for PE, possibly because of the greater age of the patients in the long-term paralysis group.

Topics: Acute Disease; Adult; Case-Control Studies; Chronic Disease; Disease Progression; Fibrin; Fibrinogen; Half-Life; Humans; Iodine Radioisotopes; Male; Middle Aged; Paralysis; Pulmonary Embolism; Risk Factors; Spinal Cord Injuries; Time Factors; Venous Thrombosis

The differential diagnosis of acute chest pain is challenging, especially in patients with normal ECG findings, and may include coronary thrombosis or pulmonary emboli. The aim of this study was to investigate the novel fibrin-specific contrast agent EP-2104R for molecular targeted MR imaging of coronary thrombosis and pulmonary emboli.. Fresh clots were engineered ex vivo from human blood and delivered in the lungs and coronary arteries of 7 swine. Subsequent molecular MR imaging was performed with a navigator-gated free-breathing and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence before and after systemic administration of 7.5 micromol/kg EP-2104R. Two swine served as the control group. MR images were analyzed by 2 investigators, and contrast-to-noise ratio and gadolinium concentration in the clots were assessed. Before contrast media application, no thrombi were visible. After contrast administration, all 32 pulmonary emboli, 3 emboli in the right heart, and 5 coronary thrombi were selectively visualized as white spots with a mean contrast-to-noise ratio of 32+/-19. The average gadolinium concentration from all 3 types of thrombi was 144+/-79 micromol/L.. Molecular MR imaging with the fibrin-targeted contrast-agent EP-2104R allows selective visualization of acute coronary, cardiac, and pulmonary thrombi.

Topics: Angiography; Animals; Chest Pain; Contrast Media; Coronary Thrombosis; Diagnosis, Differential; Fibrin; Gadolinium; Humans; Magnetic Resonance Imaging; Peptides; Pulmonary Embolism; Sus scrofa; Tomography, Spiral Computed

The present study was designed to determine the cutoff values of D-dimer and soluble fibrin (SF) for the diagnosis of deep venous thrombosis (DVT) and pulmonary embolism (PE) in Japanese patients. Plasma levels of these molecules were measured in 243 patients suspected of having DVT and 100 healthy volunteers (controls). Out of 243 patients, 20 patients were diagnosed with DVT. In the control group, plasma levels of D-dimer and SF did not show normal distribution, and the 95% confidence intervals (CI) of D-dimer and SF were 2.45 microg/mL and 6.92 microg/mL, respectively. Plasma levels of D-dimer and SF of patients with DVT were significantly higher than of those without DVT. In patients with DVT, the minimum values of D-dimer and SF were 1.71 and 1.44 microg/mL, respectively. When the cutoff value was set at the average+1 SD of those of the control (D-dimer, about 1.8 microg/mL; SF, about 1.4 microg/mL), 1 and 0 patient with DVT was overlooked, respectively. The sensitivity and specificity of D-dimer and SF for DVT were 95% and 100%, and 61.9% and 53.8%, respectively. When the cutoff value was set at 95% CI of the control (D-dimer, 2.5 microg/mL; SF, 6.9 microg/mL), 2 and 9 patients with DVT were overlooked, respectively. The sensitivity and specificity of D-dimer and SF were 90% and 50%, and 77.6% and 88.3%, respectively. When the cutoff values set at 2.5 microg/mL of D-dimer or 6.9 microg/mL of SF, 1 DVT patient was overlooked, with sensitivity and specificity of 95% and 69.5%. Our data suggest that both D-dimer and SF are useful markers for the diagnosis of DVT and that measurement of both D-dimer and SF increases the sensitivity and specificity for the diagnosis of DVT/PE.

Topics: Angiography; Data Interpretation, Statistical; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Predictive Value of Tests; Pulmonary Embolism; Ultrasonography, Doppler; Venous Thrombosis

During thrombosis, P-selectin is expressed on the surface of activated endothelial cells and platelets. We hypothesized that targeting a plasminogen activator (PA) to P-selectin would enhance local thrombolysis and reduce bleeding risk. Previously, a urokinase (uPA)/anti-P-selectin antibody (HuSZ51) fusion protein was shown to increase fibrinolysis in a hamster pulmonary embolism model. To explore the therapeutic potential of this targeting strategy, we fused the fibrin-selective Desmodus rotundus salivary PA alpha1 (dsPA alpha 1) to HuSZ51 and compared the fibrinolytic activity of P-selectin-targeted dsPA alpha 1 (HuSZ51-dsPA alpha 1) to unmodified dsPA alpha 1 in vitro and in vivo. HuSZ51-dsPA alpha 1 and dsPA alpha 1 were expressed in CHO cells and purified to homogeneity by affinity chromatography. HuSZ51-dsPA alpha 1 bound to thrombin-activated human and dog platelets with comparable affinities to that of parental antibody SZ51. The fusion protein retained the catalytic activities of dsPA alpha 1 in chromogenic and clot lysis assays, indicating that dsPA alpha 1 is fully functional when fused to HuSZ51. Compared to dsPA alpha 1, HuSZ51-dsPA alpha 1 had similar thrombolytic efficacy in a rat pulmonary embolism model and anti-thrombotic potency in a dog model of femoral artery thrombosis. However, HuSZ51-dsPA alpha 1 was less effective in lysis of preexisting arterial thrombi in the dog model. The reduced arterial thrombolysis was not due to the pharmacokinetic properties of HuSZ51-dsPA alpha 1 because antigen level and amidolytic activity were higher in plasma from HuSZ51-dsPA alpha 1-treated groups than corresponding dsPA alpha 1-treated groups. These data indicate that the thrombolytic efficacy of HuSZ51-dsPA alpha 1 varied dependent on the physical composition of thrombi. The lack of stimulation by fibrin in arterial thrombi may contribute to the attenuated thrombolytic efficacy of HuSZ51-dsPA alpha 1 in the dog model.

Topics: Animals; Antibodies, Monoclonal; Blood Platelets; Disease Models, Animal; Dogs; Fibrin; Fibrinolytic Agents; Genetic Engineering; Humans; Immunoconjugates; P-Selectin; Plasminogen Activators; Platelet Aggregation; Pulmonary Embolism; Rats; Recombinant Fusion Proteins; Thrombin; Thrombolytic Therapy; Thrombosis; Treatment Outcome

Complications of central venous catheters occur in less than 1% of all insertions. Of these, pulmonary air embolism is a rare though often fatal complication. Possible mechanisms include opening of the line to the atmosphere during use and poor technique during insertion or removal. There has also been speculation that the presence of a fibrin sheath after removal might be a mechanism for air entry. We present a case of a near-fatal pulmonary air embolus with documentation of air in the pulmonary outflow trunk and a residual air-filled fibrin tract seen on computed tomography.

Topics: Adult; Catheterization, Central Venous; Device Removal; Embolism, Air; Fibrin; Humans; Male; Pulmonary Embolism; Tomography, X-Ray Computed

Venous thrombosis is a serious disorder that may be fatal if complicated by pulmonary embolism. Venous thrombosis is usually related to one of three factors: reduced blood flow, changes in vessel wall integrity, or changes in the blood composition. Factors leading to thrombosis are classified as either genetic or acquired. Puerperium and oral contraceptives are examples of the acquired factors. The risk of thrombosis during pregnancy is high compared to that in the overall population,. however, this increases by three to five times in puerperium. Deep vein thrombosis (DVT) complicated by pulmonary thromboembolism (PE) is considered the leading cause of maternal death in the United States and Europe [Am. J. Obstet. Gynecol. 164 (1991) 603; Obstet. Gynecol. 84 (1994) 240] and the third cause in Japan [M Ishikawa, Maternal mortality and pulmonary thromboembolism. Study on maternal mortality in Japan. Report from the Ministry of Health of Japan in Maternal and Child Health Research, 1996. p. 123-128]. Patients without history of familial thrombophilia have 14-fold higher risk of DVT during puerperium [Thromb. Haemost. 25 (1999) 610]. Little is known about the underlying mechanism of thrombotic disorders in puerperium. It is recognized that oral contraceptive estrogen enhances the risk of DVT [Am. J. Epidemiol. 133 (1991) 32]. However, there is little research regarding the relation between estrogen and blood coagulation, although it is known that plasma estrogen reaches extremely high levels near term. We assume that high-level plasma estrogen plays an important role in the blood coagulation activity that results in the occurrence of DVT. To assess this likely association, we studied the effects of high estrogen levels on coagulation in rat plasma.

Topics: Animals; Blood Coagulation; Blood Coagulation Tests; Disease Models, Animal; Estradiol; Estrogens; Female; Fibrin; Pulmonary Embolism; Rats; Rats, Sprague-Dawley; Thrombin; Time Factors

The reciprocal activation of plasminogen and prourokinase (pro-u-PA) is an important mechanism in the initiation and propagation of local fibrinolytic activity. We have found that a bacterial lipopeptide compound, surfactin C (3-20 microM), enhances the activation of pro-u-PA in the presence of plasminogen. This effect accompanied increased conversions of both pro-u-PA and plasminogen to their two-chain forms. Surfactin C also elevated the rate of plasminogen activation by two-chain urokinase (tcu-PA) while not affecting plasmin-catalyzed pro-u-PA activation and amidolytic activities of tcu-PA and plasmin. The intrinsic fluorescence of plasminogen was increased, and molecular elution time of plasminogen in size-exclusion chromatography was shortened in the presence of surfactin C. These results suggested that surfactin C induced a relaxation of plasminogen conformation, thus leading to enhancement of u-PA-catalyzed plasminogen activation, which in turn caused feedback pro-u-PA activation. Surfactin C was active in enhancing [125I]fibrin degradation both by pro-u-PA/plasminogen and tcu-PA/plasminogen systems. In a rat pulmonary embolism model, surfactin C (1 mg/kg, i.v.) elevated 125I plasma clot lysis when injected in combination with pro-u-PA. The present results provide first evidence that pharmacological relaxation of plasminogen conformation leads to enhanced fibrinolysis in vivo.

Topics: Animals; Bacillus; Fibrin; Fibrinolysis; Lipopeptides; Lipoproteins; Male; Molecular Structure; Peptides, Cyclic; Plasminogen; Protein Conformation; Pulmonary Embolism; Rats; Rats, Wistar; Recombinant Proteins; Urokinase-Type Plasminogen Activator

This study assessed the abundance and activity of thrombin in human thrombi. removed at autopsy or during surgery. Arterial and venous thrombus sections showed thrombin activity by in situ zymography, based on conversion of fibrinogen to fibrin. Hirudin or antibodies to thrombin abolished the activity. Thrombin activity in extracts of 40 thrombi was quantified by cleavage of fibrinogen or small peptide substrates: the results correlated well (r = 0.87, p<0.0001) with a median activity of about 4.5 IU/g of thrombus (wet weight). Activity correlated poorly with total prothrombin (median 27 microg/g) and was inversely related to antithrombin, but not to PAI-1. Zymography showed two major active bands, thrombin at 37 kDa, and a 50 kDa form that probably corresponds to meizothrombin desF1. The abundant local thrombin demonstrated here has implications for thrombus lysis and extension: incomplete lysis and exposure of active thrombin may lead to re-occlusion of vessels.

Topics: Antithrombin III; Blotting, Western; Chromogenic Compounds; Dipeptides; Enzyme-Linked Immunosorbent Assay; Fibrin; Fibrinogen; Humans; Plasminogen Activator Inhibitor 1; Prothrombin; Pulmonary Embolism; Thrombin; Venous Thrombosis

To increase thrombolytic specificity of urokinase (uPA), we engineered a recombinant chimeric plasminogen activator SZ51Hu-scuPA, which consists of a humanized monoclonal antibody (SZ-51Hu) specifically against P-selectin on activated human platelet and a single-chain urokinase (scuPA). The cDNA, encoding scuPA amino acids 1-411, was inserted in 5' end to 3' end orientation immediately after the CH3 of SZ-51Hu heavy-chain sequence in the expression vector alphaLys30. The resulting construct alphaLys30-SZ51VH/Hu-scuPA was used to transfect into SP2/0 murine myeloma cell line, which was pretransfected with SZ51Hu light chain. The fusion protein SZ51Hu-scuPA was expressed at 5 mg/L in the supernatant of cell culture. The fusion protein purified by affinity chromatography had a molecular weight of 160 kDa with fibrinolytic activity of 39,000 IU/mg and its affinity to activated human platelet was 67% of the parent murine mAb SZ-51. The thrombolytic property of the fusion protein was first characterized in an in vitro system, which consists of a 125I-fibrin-labeled human plasma clot containing different concentrations of human platelets suspended in citrated human plasma. Fifty percent lysis was reached with SZ51Hu-scuPA in 1 hour at a concentration of 20 IU/mL or in 2 hours at a concentration of 10 IU/ mL, which was much faster than uPA at the same concentration. The maximal lysis of the clots by SZ51Hu-scuPA was 4.1 to 8.4 times more potent than that by uPA. The fusion protein was further characterized in the hamster pulmonary embolism model with clots prepared from fresh platelet-rich human plasma containing 125I-labeled fibrinogen. The thrombolytic activity of SZ51-scuPA was 3.9 times more potent than that of uPA at 2,000 IU/kg in this model. Almost no significant fibrinogen breakdown was observed either in vitro and in vivo.

Topics: Animals; Antibodies, Monoclonal; Antibody Affinity; Blood Coagulation; Blood Platelets; Cricetinae; Disease Models, Animal; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Fibrin; Fibrinolytic Agents; Genetic Vectors; Humans; Iodine Radioisotopes; Mice; P-Selectin; Platelet Activation; Protein Engineering; Pulmonary Embolism; Recombinant Fusion Proteins; Thrombolytic Therapy; Tumor Cells, Cultured; Urokinase-Type Plasminogen Activator

The role of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in fibrinolysis remains unsettled. The contribution of uPA may depend on the vascular location, the physical properties of the clot, and its impact on tissue function. To study the contribution of urokinase within the pulmonary microvasculature, a model of pulmonary microembolism in the mouse was developed. Iodine 125 ((125)I)-labeled fibrin microparticles injected intravenously through the tail vein lodged preferentially in the lung, distributing homogeneously throughout the lobes. Clearance of (125)I-microemboli in wild type mice was rapid and essentially complete by 5 hours. In contrast, uPA(-/-) and tissue-type plasminogen activator tPA(-/-) mice, but not uPAR(-/-) mice, showed a marked impairment in pulmonary fibrinolysis throughout the experimental period. The phenotype in the uPA(-/-) mouse was rescued completely by infusion of single chain uPA (scuPA). The increment in clot lysis was 4-fold greater in uPA(-/-) mice infused with the same concentration of scuPA complexed with soluble recombinant uPAR. These data indicate that uPA contributes to endogenous fibrinolysis in the pulmonary vasculature to the same extent as tPA in this model system. Binding of scuPA to its receptor promotes fibrinolytic activity in vivo as well as in vitro. The physical properties of fibrin clots, including size, age, and cellular composition, as well as heterogeneity in endothelial cell function, may modify the participation of uPA in endogenous fibrinolysis. (Blood. 2000;96:1820-1826)

Topics: Animals; Disease Models, Animal; Fibrin; Fibrinogen; Fibrinolysis; Humans; Immunohistochemistry; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Mutant Strains; Microspheres; Particle Size; Pulmonary Circulation; Pulmonary Embolism; Receptors, Cell Surface; Receptors, Urokinase Plasminogen Activator; Recombinant Proteins; Tissue Distribution; Urokinase-Type Plasminogen Activator

Because the increased fibrinolytic resistance of older thrombi may be caused by the continuous cross-linking action of fibrin-bound activated factor XIII (FXIIIa), we examined the persistence of FXIIIa catalytic activity in clots of various ages.. The time-related changes in FXIIIa activity in clots was measured with (1) alpha(2)-antiplasmin (alpha(2)AP), a physiological glutamine substrate; (2) alpha(2)AP(13-24), a peptide; and (3) pentylamine, a nonspecific lysine substrate. The cross-linking of alpha(2)AP, alpha(2)AP(13-24), and pentylamine into fibrin by clot-bound FXIIIa declined rapidly with half-lives of 19, 21, and 26 minutes, respectively. Mutational studies showed that glutamine 14 (but not glutamine 3 or 16) and valine 17 of alpha(2)AP(13-24) were required for efficient cross-linking to fibrin. The loss of activity was not due primarily to FXIIIa proteolysis and was partially restored by reducing agents, suggesting that oxidation contributes to the loss of the enzyme's activity in clots. In vivo, the ability of thrombus-bound FXIIIa to cross-link an infused alpha(2)AP(13-24) peptide into existing pulmonary emboli also declined significantly over time.. FXIIIa cross-links alpha(2)AP and an alpha(2)AP peptide, in a sequence-specific manner, into formed clots with a catalytic half-life of approximately 20 minutes. This indicates that FXIIIa activity is a hallmark of new thrombi and that the antifibrinolytic cross-linking effects of FXIIIa are achieved more rapidly in thrombi than previously believed.

Topics: Aging; Animals; Cross-Linking Reagents; Drug Resistance; Ferrets; Fibrin; Fibrinolysis; Fibrinolytic Agents; Half-Life; Humans; Iodine Radioisotopes; Mice; Mice, Inbred C57BL; Pulmonary Embolism; Thrombosis; Transglutaminases

We prospectively evaluated the diagnostic performance of a new soluble fibrin assay in 303 consecutive patients with suspected pulmonary embolism and examined potentially useful cut-off levels at which this disease can be safely excluded. In addition, the diagnostic accuracy was calculated in the subgroups of in- and outpatients. The ROC curve of the assay in the total study cohort had an area under the curve of 0.69. The cut-off level associated with a sensitivity and negative predictive value of 100% was 20 ng/ml, but the specificity was only 4%. The cut-off level with a sensitivity of 90% was 30 ng/ml, which corresponded with a specificity and negative predictive value of 27% and 86%. respectively. The diagnostic performance was comparable in the subgroups of in- and outpatients. We conclude that the soluble fibrin assay has a low diagnostic accuracy and seems unsuitable as a screening test for the exclusion of pulmonary embolism.

Topics: Adult; Aged; Antibodies, Monoclonal; Cohort Studies; Diagnostic Errors; Female; Fibrin; Humans; Immunoenzyme Techniques; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Pulmonary Embolism; ROC Curve; Sensitivity and Specificity; Solubility

Topics: Adult; Anticoagulants; Drug Interactions; Emergencies; Female; Fibrin; Humans; Levonorgestrel; Pulmonary Embolism; Venous Thrombosis; Warfarin

Molecular basis of antithrombin deficiency has not yet been studied in Czech Republic. We looked for the causal mutations throughout the antithrombin gene in 26 patients from 10 unrelated families with antithrombin defect.. We screened the gene by conformation sensitive gel electrophoresis and sequenced the mismatched regions using fluorescence technology to characterise mutations and polymorphisms. Mutations were detected in all ten families. Four novel mutations were identified in four families with type I antithrombin defect: Trp-6Arg, 5386-5387delCT, Glu163Stop, and 13246-13248del TGA causing deletion of Glu377 with change of Asn376 to Lys. In other three type I families we found following mutations: splicing site mutation G2777C, Arg197Stop and entire gene deletion. In the family carrying Trp-6Arg mutation antithrombin Vienna (Gln118Pro) was also detected. Leu99Phe recurrent in south-eastern Europe was identified in three families with type II defect. Only the homozygous carries of the mutation were symptomatic, although the heterozygous carries had decreased functional levels.. Four novel mutations in families with type I antithrombin deficiency were characterised. In one family two different genetic defects were identified to be responsible for type I and II phenotypes. Altogether our data agree with the expected heterogeneity of the AT genetic defect.

Topics: Adolescent; Adult; Child; Fibrin; Humans; Mutation; Polymerase Chain Reaction; Polymorphism, Genetic; Pulmonary Embolism; Thrombosis

The resistance of thrombi to fibrinolysis induced by plasminogen activators remains a major impediment to the successful treatment of thrombotic diseases. This study examines the contribution of activated factor XIII (factor XIIIa) to fibrinolytic resistance in experimental pulmonary embolism.. The fibrinolytic effects of specific inhibitors of factor XIIIa-mediated fibrin-fibrin cross-linking and alpha2-antiplasmin-fibrin cross-linking were measured in anesthetized ferrets with pulmonary emboli. Five experimental groups were treated with heparin (100 U/kg) and/or tissue plasminogen activator (TPA, 1 mg/kg) and the percent (mean+/-SD) lysis of emboli was determined: (1) control, normal factor XIIIa activity (14.1+/-4. 8% lysis); (2) inhibited factor XIIIa activity (42.7+/-7.4%); (3) normal factor XIIIa activity+TPA (32.3+/-7.7%); (4) inhibited factor XIIIa activity+TPA (76.0+/-11.9%); and (5) inhibited alpha2-antiplasmin-fibrin cross-linking+TPA (54.7+/-3.9%). Inhibition of factor XIIIa activity increased endogenous lysis markedly (group 1 versus 2; P<0.0001), to a level comparable to that achieved with TPA (group 2 versus 3; P<0.05). Among groups receiving TPA, selective inhibition of factor XIII-mediated alpha2-antiplasmin-fibrin cross-linking enhanced lysis (group 3 versus 5; P<0.0005). Complete inhibition of factor XIIIa also amplified lysis (group 3 versus 4; P<0.0001) and had greater effects than inhibition of alpha2-antiplasmin cross-linking alone (group 4 versus 5; P<0.0005). No significant fibrinogen degradation occurred in any group.. Factor XIIIa-mediated fibrin-fibrin and alpha2-antiplasmin-fibrin cross-linking both caused experimental pulmonary emboli to resist endogenous and TPA-induced fibrinolysis. This suggests that factor XIIIa may play a critical role in regulating fibrinolysis in human thrombosis.

Topics: alpha-2-Antiplasmin; Animals; Factor XIII; Ferrets; Fibrin; Fibrinogen; Fibrinolysis; Heparin; Male; Pulmonary Embolism; Tissue Plasminogen Activator

Many studies have shown that D-dimer determinations can be used for the exclusion of venous thromboembolism in symptomatic outpatients, depending however on the method of D-dimer measurement. Another related assay, the Fibrin Monomer test which measures soluble fibrin levels in plasma by ELISA, is now available. We have evaluated the performances of this assay for the exclusion of pulmonary embolism (PE) in 426 consecutive outpatients presenting at the emergency ward of our institution. Diagnosis of PE was made by D-dimer measurement, compression ultrasonography, lung scintigraphy, venography and pulmonary angiography. With a cut-off of 3 microg/ml. the sensitivity and the negative predictive value were both 100% (95% CI: 97.1-100 and 96.3-100 respectively) and the specificity 33% (95 % CI: 25.7-38.1). With 4 microg/ml, the corresponding figures were 98.4 (95% CI: 94.4-99.8), 98.3 (95% CI: 94.1-99.8) and 39% (95% CI: 33.6-44.7) respectively. The prevalence of PE was 30%, the exclusion rates were 23 and 27% for either cut-off. When compared with a reference D-dimer assay (Asserachrom D-Di), a good correlation was observed. In conclusion, this is the first study suggesting the interest of this Fibrin Monomer test to rule out PE; these results, however, need to be confirmed by other studies.

Topics: Emergencies; Enzyme-Linked Immunosorbent Assay; Evaluation Studies as Topic; Fibrin; Fibrin Fibrinogen Degradation Products; Follow-Up Studies; Humans; Predictive Value of Tests; Prevalence; Pulmonary Embolism; Radiography; Radionuclide Imaging; ROC Curve; Sensitivity and Specificity; Single-Blind Method; Ultrasonography

Heparin cofactor II (HCII) is a specific inhibitor of thrombin in the presence of heparin or dermatan sulphate. Although there have been reports on families in which a heterozygous HCII deficiency is associated with thromboembolic events, several epidemiological studies revealed that heterozygous HCII deficiency is as prevalent among healthy subjects as it is among patients with deep venous thrombosis (DVT). It is therefore not yet clear whether HCII is or is not a thrombotic risk factor. We analyze and describe in an extended family the biochemical and genetic thrombophilic risk factors and evaluate the potential thrombotic risk involved in homozygous and heterozygous HCII deficiency, either alone or associated with other thrombotic or circumstantial risk factors. The propositus has had three episodes of DVT and a pulmonary embolism. During the first episode of DVT the patient was diagnosed as having AT deficiency. Later, a functional and antigenic HCII deficiency, compatible with the homozygous form, was detected. The family study shows that both the propositus and her sister have homozygous HCII deficiency and that 12 of the 27 family members have heterozygous HCII deficiency. This is possibly the first case report on a homozygous phenotype for the HCII deficiency with. in addition, partial AT deficiency. The propositus has suffered several thrombotic events, unlike the other 12 family members with heterozygous HCII deficiency and her sister, who is also homozygous for this disorder. We suggest that HCII deficiency may play a limited in vivo role as a thrombotic risk factor unless associated with AT deficiency or another congenital thrombotic risk factor.

Topics: Adolescent; Adult; Anticoagulants; Child; Child, Preschool; Female; Fibrin; Heparin Cofactor II; Heterozygote; Homozygote; Humans; Infant; Male; Middle Aged; Pedigree; Phenotype; Pregnancy; Pregnancy Complications, Hematologic; Pulmonary Embolism; Risk Factors; Venous Thrombosis

Activated protein C (APC) is a potent physiologic anticoagulant with profibrinolytic properties, and has been shown to prevent thrombosis in different experimental models. We investigated the effect of human APC on thrombin-induced thromboembolism in mice, a model of acute intravascular fibrin deposition leading to death within minutes. APC given intravenously (i.v.) as a bolus 2 min before thrombin challenge (1,250 U/kg) reduced mortality in a dose-dependent manner despite the lack of thrombin inhibitor activity. Significant inhibition of thrombin-induced death was observed at the dose of 0.05 mg/kg, and maximal protection was obtained with 2 mg/kg (> 85% reduction in mortality rate). Histology of lung tissue revealed that APC treatment (2 mg/kg) reduced significantly vascular occlusion rate (from 89.2 to 46.6%, P < 0.01). The protective effect of APC was due to the inhibition of endogenous thrombin formation as indicated by the fact that (a) the injection of human thrombin caused a marked decrease in the coagulation factors of the intrinsic and common pathways (but not of Factor VII), suggesting the activation of blood clotting via the contact system; (b) APC pretreatment reduced markedly prothrombin consumption; (c) the lethal effect of thrombin was almost abolished when the animals were made deficient in vitamin K-dependent factors by warfarin treatment, and could be restored only by doubling the dose of thrombin, indicating that the generation of endogenous thrombin contributes significantly to death; and (d) APC failed to protect warfarin-treated animals, in which mortality is entirely due to injected thrombin, even after protein S supplementation. Other results suggest that APC protects from thrombin-induced thromboembolism by rendering the formed fibrin more susceptible to plasmin degradation rather than by reducing fibrin formation: in thrombin-treated mice, fibrinogen consumption was not inhibited by APC; and inhibition of endogenous fibrinolysis by epsilon-aminocaproic or tranexamic acid resulted in a significant reduction of the protective effect of APC. Since APC did not enhance plasma fibrinolytic activity, as assessed by the measurement of plasminogen activator (PA) or PA inhibitor (PAI) activities, PAI-1 antigen, or 125I-fibrin degrading activity, we speculate that the inhibition of additional (endogenous) thrombin formation by APC interrupts thrombin-dependent mechanisms that make fibrin clots more resistant to lysis, so that the intravas

Topics: Animals; Anticoagulants; Coagulants; Disease Models, Animal; Enzyme Activation; Fibrin; Fibrinolytic Agents; Humans; Lung; Male; Mice; Protein C; Pulmonary Embolism; Thrombin

We present a patient with a large tumor embolus attached to a pacemaker electrode leading to multiple pulmonary emboli. At postmortem examination, this thrombus was composed of clusters of well-differentiated squamous cell carcinoma intermingled with fibrin. Tumor involvement was not evident in the myocardium, endocardium, or epicardium. The primary tumor was discovered in the lower intrathoracic esophagus. Tumor microemboli from the esophageal primary lesions may have accumulated around the pacemaker electrode due to turbulent flow in this region, producing a large and friable tumor embolus.

Topics: Aged; Aged, 80 and over; Carcinoma, Squamous Cell; Electrodes, Implanted; Esophageal Neoplasms; Fatal Outcome; Fibrin; Hemorheology; Humans; Male; Neoplastic Cells, Circulating; Pacemaker, Artificial; Pulmonary Embolism

Accurate non-invasive diagnosis of deep venous thrombosis and pulmonary embolism remains an elusive goal. Radiolabeled antibodies specific for the epitope exposed on the beta-chain of fibrin after fibrino-peptide B release (anti-beta) enabled in situ imaging of thrombi in experimental subjects with nuclear medicine techniques. When used in patients anticoagulated for thrombo-embolic disease, however, the antibody was unable to reliably image the thrombi. We postulated that the neoepitope on the beta-chain of fibrin is covered up as fibrin organizes into a polymer network and is therefore exposed to the antibody only during active incorporation of fibrin subunits. We determined the equilibrium binding kinetics of an anti-beta monoclonal antibody to fibrin in various stages of organization. The concentration of exposed epitopes on immobilized fibrin monomers was equal to the molar concentration of fibrin beta-chains. The percentage of beta-chains exposed to the antibodies markedly decreased as the fibrin network was allowed to organize, a process catalyzed by calcium.. The beta-chain amino terminus of fibrin is exposed transiently as subunits are added to the enlarging fibrin network. Anti-beta antibodies bind preferentially to actively enlarging fibrin polymers.

Topics: Antibodies, Monoclonal; Antigen-Antibody Reactions; Biopolymers; Fibrin; Fibrinolytic Agents; Heparin; Humans; Peptide Fragments; Pulmonary Embolism; Thrombophlebitis

Topics: Bacteremia; Catheterization, Central Venous; Citrobacter freundii; Contrast Media; Enterobacteriaceae Infections; Fibrin; Humans; Jugular Veins; Male; Middle Aged; Pulmonary Embolism; Radiography; Radionuclide Imaging; Renal Dialysis

Diagnostic and therapeutic procedures utilizing the high affinity streptavidin (SA)/biotin system are being investigated for in vivo use. We are developing a rapid two-step imaging technique for the diagnosis of deep venous thrombosis and pulmonary embolism. The optimal SA-bound targeting moiety would circulate adequately for sufficient lesion accumulation, but nonbound reagent would clear in a reasonably short time before the injection of radiolabeled biotin. The objective of this study was to cross-link SA and galactose-modified SA to GC4 antifibrin monoclonal antibody and to study the pharmacokinetics and biodistribution of the radiolabeled GC4-SA conjugates after injection into rabbits. A cross-linking method was developed for the synthesis of the GC4-SA conjugates via the addition reaction of sulfhydryl containing SA derivatives with maleimide-GC4. In vivo, radiolabeled trigalactose modified SA-GC4 exhibited a much faster blood clearance compared to mono-galactose modified GC4-SA or GC4-SA containing no galactose.

Topics: Animals; Antibodies, Monoclonal; Bacterial Proteins; Fibrin; Galactose; Iodine Radioisotopes; Pulmonary Embolism; Rabbits; Radioimmunodetection; Streptavidin; Thrombophlebitis

In order to determine the clinical utility of an enzyme immunoassay (EIA) for soluble fibrin in patients with suspected pulmonary embolism (PE), 195 unselected patients with suspected PE underwent blood sampling for measurement of plasma levels of soluble fibrin, and objective testing for PE. A soluble fibrin result of < or = 0.75 micrograms/ml showed a sensitivity of 100% for PE and a specificity of 12.8%, whereas a soluble fibrin result of < or = 1.35 micrograms/ml showed a sensitivity of 90.3% and a specificity of 49.4% for PE. The soluble fibrin assay has potential clinical utility in excluding PE.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Evaluation Studies as Topic; Female; Fibrin; Humans; Immunoenzyme Techniques; Likelihood Functions; Male; Middle Aged; Predictive Value of Tests; Pulmonary Embolism; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Solubility

To determine the volume and composition of clot within thrombosed hemodialysis access grafts.. Clots were collected in 22 patients at surgical thrombectomy of polytetrafluoroethylene grafts. Histologic analysis was performed in 10 of these clots plus 21 randomly selected clots from the pathology archives.. A small, firm piece of whitish thrombus ("arterial plug") was almost always recovered from the arterial limb of the graft. This plug had a concave surface and ranged from 5 mm to 3 cm in length. The remaining clot was soft, red thrombus. The mean weight of all clots was 3.4 g, and mean volume was 3.2 cm3. Average graft length was 42 cm. Histologically, the arterial plug had a characteristic appearance of densely compacted alternating layers of erythrocytes and fibrin.. Clot volume in thrombosed dialysis grafts is much less (approximately equal to 25%) than would be expected if the graft were completely filled with thrombus, a finding of significance to mechanical thrombolytic techniques. Resistance of the arterial plug to pulse-spray thrombolysis is likely due to compaction.

Topics: Arm; Arteriovenous Shunt, Surgical; Biocompatible Materials; Blood Platelets; Brachial Artery; Catheters, Indwelling; Color; Erythrocytes; Fibrin; Humans; Leukocytes; Polytetrafluoroethylene; Pulmonary Embolism; Renal Dialysis; Thrombectomy; Thrombolytic Therapy; Thrombosis; Urokinase-Type Plasminogen Activator; Veins

Pulmonary emboli are detectable by filling defects in the pulmonary vasculature upon pulmonary angiography. Emboli derived from venous thrombi are rich in fibrin to which thrombin remains bound. Hirudin, a specific thrombin inhibitor, binds to thrombin to yield a 1:1 stoichiometric complex. We examined whether 131I-recombinant hirudin (r-hirudin) could be used to detect pulmonary emboli in rabbits. Clots were formed by re-calcifying rabbit plasma in vitro, and then injected (0.034 ml) into a femoral vein to lodge in the lungs. 131I-r-hirudin (29 +/- 4 microCi/kg) was injected intravenously but emboli could not be detected by gamma camera in real time. Post-mortem analysis of lung tissue showed that 131I-r-hirudin did not associate with emboli prepared with 125I-fibrin. Because of these findings, we used different techniques to look at the binding of hirudin to plasma clots. Clots formed in vitro were incubated with 131I-r-hirudin in the presence of equimolar amounts of 125I-albumin; specific binding of 131I-r-hirudin was not observed. Experiments with immobilized fibrin(ogen) showed that 125I-r-hirudin did not bind to and remain with fibrin-bound 131I-thrombin but did lead to the inactivation and displacement of up to 70% of bound thrombin as r-hirudin-thrombin complex; residual thrombin bound to fibrin remained active. Thus, released r-hirudin-thrombin complex is probably cleared rapidly from the region of the embolus in vivo; radioiodinated r-hirudin may not, therefore, be useful as a marker for detecting emboli.

Topics: Animals; Chromatography, Affinity; Femoral Vein; Fibrin; Hirudins; Iodine Radioisotopes; Lung; Male; Protein Binding; Pulmonary Embolism; Rabbits; Radionuclide Imaging; Recombinant Proteins; Thrombin

The effects of plasminogen activator inhibitor-1 (PAI-1) gene inactivation on hemostasis, thrombosis and thrombolysis were studied in homozygous PAI-1-deficient (PAI-1-/-) mice, generated by homologous recombination in D3 embryonic stem cells. Diluted (10-fold) whole blood clots from PAI-1-/- and from PAI-1 wild type (PAI-1+/+) mice underwent limited but significantly different (P < 0.001) spontaneous lysis within 3 h (6 +/- 1 vs 3 +/- 1%, respectively). A 25-microliters 125I-fibrin-labeled normal murine plasma clot, injected into a jugular vein, was lysed for 47 +/- 5, 66 +/- 3, and 87 +/- 7% within 8 h in PAI-1+/+, heterozygous PAI-1-deficient (PAI-1+/-), and PAI-1-/- mice, respectively (P = 0.002 for PAI-1+/+ vs PAI-1-/- mice). Corresponding values after pretreatment with 0.5 mg/kg endotoxin in PAI-1+/+ and PAI-1-/- mice, were 35 +/- 5 and 91 +/- 3% within 4 h, respectively (P < 0.001). 11 out of 26 PAI-1+/+ but only 1 out of 25 PAI-1-/- mice developed venous thrombosis (P = 0.004) within 6 d after injection of 10 or 50 micrograms endotoxin in the footpad. Spontaneous bleeding or delayed rebleeding could not be documented in PAI-1-/- mice after partial amputation of the tail or of the caecum. Thus, disruption of the PAI-1 gene in mice appears to induce a mild hyperfibrinolytic state and a greater resistance to venous thrombosis but not to impair hemostasis.

Topics: Analysis of Variance; Animals; Cecum; Endotoxins; Erythrocyte Count; Fibrin; Fibrinolysis; Hematocrit; Hemoglobins; Hemorrhage; Hemostasis; Mice; Mice, Inbred Strains; Plasminogen Activator Inhibitor 1; Platelet Count; Pulmonary Embolism; Thrombosis

The aim of this study was to investigate the interactions of t-PA and plasminogen with fibrin derived from an abnormal fibrinogen detected in a 40-year-old male patient who had had an episode of thrombophlebitis with pulmonary embolism. An abnormal fibrinogen was diagnosed on the basis of prolonged thrombin and reptilase times also detected in two other family members. Fibrinogen purified from plasma, in the presence of protease inhibitors, by glycine precipitations, gel filtration and affinity chromatography, was devoid of plasminogen, fibronectin, and vWf. SDS-PAGE analysis according to Laemmli under reducing conditions, showed an abnormal gamma chain (approximately 50% of the total) migrating in a more anodic position (M(r) 48 kDa). By PCR amplification and DNA sequencing, the abnormality was identified as an Asn308-->Lys mutation of the gamma chain. Since such a mutation constitutes a new plasmin cleavage site as first reported for fibrinogen Kyoto I, it may modify interactions of plasminogen and t-PA with carboxy-terminal lysine residues. Ligand-binding studies were therefore performed using intact and plasmin-degraded fibrin surfaces obtained from the abnormal fibrinogen. The plasminogen and t-PA binding isotherms obtained with the abnormal fibrinogen were similar to the control. Moreover, the stimulation by fibrin of plasminogen activation by t-PA was not different from the control. These results suggest (i) that the lysine 308 residue may not be exposed to plasmin cleavage in fibrin, and (ii) that the thrombotic accident of the propositus cannot be explained by an abnormality of the plasminogen/t-PA binding to fibrin.

Topics: Adult; Base Sequence; Electrophoresis, Polyacrylamide Gel; Fibrin; Fibrinogens, Abnormal; Hemostasis; Humans; Male; Molecular Sequence Data; Mutation; Pedigree; Plasminogen; Polymerase Chain Reaction; Pulmonary Embolism; Sequence Analysis, DNA; Thrombin Time; Thrombophlebitis; Tissue Plasminogen Activator

The pharmacokinetic and thrombolytic properties were determined of two recombinant single-chain chimeric plasminogen activators (PA) consisting of u-PA-33k, a low-molecular weight derivative of single-chain urokinase-type PA (scu-PA) comprising amino acids Ala132 through Leu411, and of either a single-chain variable region fragment (Fv) derived from the fibrin fragment D-dimer-specific monoclonal antibody MA-15C5 (K12G0S32) or of the deglycosylated single-chain Fv fragment obtained by substitution of Asn88 with Glu (K12G2S32). Following bolus injection in hamsters, clearances of recombinant scu-PA (rscu-PA) and of K12G0S32 were similar. In contrast, clearance of K12G2S32 was fourfold slower than that of rscu-PA. The thrombolytic potency (percent lysis per u-PA administered in milligrams per kilogram body weight) and specific thrombolytic activity (percent lysis per microgram per milliliter steady-state plasma u-PA antigen level) of these compounds were studied in hamsters with an experimental pulmonary embolus consisting of a human plasma clot injected via the jugular vein. The doses of K12G0S32 and K12G2S32 required to obtain maximal rate of clot lysis were sixfold and 11-fold lower than that of rscu-PA. The steady-state u-PA-related plasma antigen levels of K12G0S32 and K12G2S32 required to obtain maximal rate of clot lysis were 10-fold and fourfold lower than that of rscu-PA. Thus, targeting of K12G0S32 to the clot surface by means of its glycosylated Fv fragment results in a 10-fold increase of its specific thrombolytic activity and sixfold increase of its thrombolytic potency as compared with those of rscu-PA. Targeting of K12G2S32 to the clot surface by means of its deglycosylated Fv fragment results in only a twofold increase of its thrombolytic activity. However, its fourfold slower clearance, combined with its twofold higher specific thrombolytic activity, results in an 11-fold increase of its thrombolytic potency over that of rscu-PA. These findings indicate that the thrombolytic potency of chimeric antibody-targeted PA may be increased by increasing the specific thrombolytic activity, reducing the clearance, or both.

Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Base Sequence; Cell Line; Cricetinae; DNA; Fibrin; Fibrinolytic Agents; Humans; Insecta; Macromolecular Substances; Molecular Sequence Data; Molecular Weight; Mutagenesis, Site-Directed; Oligodeoxyribonucleotides; Pulmonary Embolism; Rabbits; Recombinant Fusion Proteins; Recombinant Proteins; Urokinase-Type Plasminogen Activator

Targeting of plasminogen activators to the thrombus by means of fibrin-specific monoclonal antibodies may enhance their thrombolytic potency. The kinetics of clot binding of two human fibrin-specific monoclonal antibodies (MA-12B3 and MA-15C5) and of clot lysis with their chemical 1:1 stoichiometric complexes with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) (rscu-PA/MA-12B3 and rscu-PA/MA-15C5) were determined in hamsters and rabbits. Thrombolytic potencies, maximal rates of clot lysis, and the duration of the lag phases before clot lysis of the antibody/rscu-PA conjugates were compared with those of rscu-PA and tissue-type plasminogen activator (rt-PA).. Bolus injection of 7.5 micrograms of 125I-labeled antibody in rabbits with an extracorporeal arteriovenous loop containing a 0.3-mL human plasma clot produced clot-to-blood ratios of 6.6 +/- 1.0 (mean +/- SEM) for MA-12B3 and 1.1 +/- 0.15 for MA-15C5 (p < 0.001 versus MA-12B3) within 6 hours. Progressive digestion of the clot did not alter the binding of MA-12B3 but resulted in as much as a 10-fold increase of the binding of MA-15C5. The conjugates infused intravenously over 90 minutes in hamsters with a human plasma clot in the pulmonary artery produced dose-related in vivo clot lysis. Thrombolytic potencies (maximal slope of the percent lysis versus dose in milligrams of u-PA equivalent per kilogram body weight) were 2,500 +/- 440 for rscu-PA/MA-12B3, 3,600 +/- 640 for rscu-PA/MA-15C5 (p = NS vs. rscu-PA/MA-12B3), 60 +/- 8 for rscu-PA (p < 0.001 versus both conjugates), and 380 +/- 66 for rt-PA (p < 0.001 versus both conjugates). The plasma clearances of the conjugates were fourfold to sixfold slower than those of rscu-PA and rt-PA. Maximal rates of clot lysis, determined by continuous external radioisotope scanning over the thorax, were 0.90 +/- 0.13%, 0.91 +/- 0.17%, 0.84 +/- 0.12%, and 1.1 +/- 0.16% lysis per minute for rscu-PA/MA-12B3, rscu-PA/MA-15C5, rscu-PA, and rt-PA, respectively; these maximal rates were obtained with 0.016, 0.016, 1.0, and 0.25 mg/kg, respectively, and were associated with minimal lag phases of 18 +/- 3.2, 28 +/- 4.9, 34 +/- 3.7, and 25 +/- 3.9 minutes, respectively.. The thrombolytic potency of the rscu-PA/antifibrin conjugates is determined by their clearance, as well as by rate and extent of initial binding to clots and by changes in binding during clot lysis. Clot targeting of rscu-PA with fibrin-specific antibodies increases its thrombolytic potency but does not alter the maximal rate or the minimal lag phase of clot lysis. These parameters appear to be independent of the nature of the plasminogen activator and of targeting.

Topics: Animals; Antibodies, Monoclonal; Blood Coagulation; Cricetinae; Fibrin; Fibrinolytic Agents; Humans; Plasminogen Activators; Pulmonary Embolism; Rabbits; Recombinant Proteins; Thrombosis

Recombinant tissue-type plasminogen activator (rt-PA), produced by expression of the genomic t-PA DNA from the JMI-229 cell line, which is of rat origin, in the host cell line, was purified to homogeneity. JMI-229 rt-PA was obtained essentially as a single chain molecule which was quantitatively converted to a two-chain moiety by treatment with plasmin. The plasminogen activating potential of single chain JMI-229 rt-PA was 5-fold lower than that of commercially available human rt-PA (Actilyse) in the absence of fibrin, but comparable in the presence of fibrin; it showed a concentration-dependent binding to fibrin, with a significantly more pronounced binding than Actilyse at low fibrin concentration (85 +/- 8% versus 20 +/- 7% at 0.025 mg/ml fibrin; p = 0.004). In human plasma in the absence of fibrin, the concentrations of both single chain and two-chain JMI-229 rt-PA required to induce 50% fibrinogen degradation in 2 h, were about 15-fold higher than those of Actilyse. Both single chain and two-chain forms of JMI-229 rt-PA and of Actilyse induced a similar time- and concentration-dependent lysis of a 125I-fibrin-labeled plasma clot immersed in human plasma, in the absence of significant systemic fibrinolytic activation. Equally effective concentrations (causing 50% clot lysis in 2 h) were 0.11 or 0.10 micrograms/ml for single chain or two-chain JMI-229 rt-PA, as compared to 0.11 or 0.15 micrograms/ml for single chain or two-chain Actilyse.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amides; Animals; Cell Line; Cricetinae; Fibrin; Fibrinolysis; Humans; In Vitro Techniques; Kinetics; Plasminogen; Plasminogen Inactivators; Protein Binding; Pulmonary Embolism; Rats; Recombinant Proteins; Tissue Plasminogen Activator

A mutant of recombinant tissue-type plasminogen activator (rt-PA), obtained by deletion of residues Lys296 to Gly302 [rt-PA del(K296-G302)], was previously shown to be resistant to inhibition by plasminogen activator inhibitor-1 (PAI-1) (Madison et al, Nature 339:721, 1989). This mutant was obtained by expression of its cDNA in Chinese hamster ovary cells and purification to homogeneity from conditioned cell culture medium. It was obtained as a single chain molecule with amidolytic activity, specific fibrinolytic activity, and binding to fibrin and lysine, which were comparable or somewhat lower than those of wild-type rt-PA obtained in the same expression system. The plasminogen-activating potential of rt-PA del(K296-G302) in the presence of CNBr-digested fibrinogen was about twofold lower than that of wild-type rt-PA. The inhibition rate of rt-PA del(K296-G302) by recombinant PAI-1 (rPAI-1) was more than 500-fold lower than that of wild-type rt-PA. In a human plasma milieu in vitro, rt-PA del(K296-G302) induced dose-dependent lysis of a 125I-fibrin-labeled plasma clot; equi-effective concentrations (causing 50% clot lysis in 2 hours) were 0.28 micrograms/mL and 0.36 micrograms/mL for mutant and wild-type rt-PA, respectively. In this system, addition of rPAI-1 to the plasma resulted in a concentration-dependent reduction of the fibrinolytic potency of rt-PA del(K296-G302) and of rt-PA; a 50% reduction required 2.4 micrograms/mL and 0.15 micrograms/mL rPAI-1, respectively. Continuous infusion of mutant or wild-type rt-PA over 60 minutes in hamsters with a 125I-labeled plasma clot in the pulmonary artery resulted in dose-dependent clot lysis, with a thrombolytic potency (percent clot lysis per milligram of compound administered per kilogram of body weight) and a specific thrombolytic activity (percent clot lysis per microgram per milliliter steady state rt-PA-related antigen level in plasma) that were not significantly different. Bolus injection in hamsters of 1 mg/kg rPAI-1 followed by bolus injection of 1 mg/kg rt-PA del(K296-G302) or wild-type rt-PA resulted in neutralization of the thrombolytic potency of wild-type rt-PA, while the mutant retained approximately half of its thrombolytic potency. These results indicate that rt-PA del(K296-G302), with a known resistance to inhibition by rPAI-1 in purified systems, maintains this property both in a plasma milieu in vitro and in an experimental animal model of thrombolysis in vivo.(ABSTRACT TRUNCATED AT 400

Topics: Amino Acid Sequence; Animals; Chemical Phenomena; Chemistry, Physical; Chromogenic Compounds; Cricetinae; DNA; Fibrin; Fibrinogen; Fibrinolysis; Gene Expression; Humans; Hydrolysis; Kinetics; Molecular Sequence Data; Mutagenesis, Site-Directed; Oligopeptides; Plasminogen; Plasminogen Inactivators; Pulmonary Embolism; Recombinant Proteins; Tissue Plasminogen Activator

A hybrid hybridoma (FU1-74), secreting a bispecific monoclonal antibody (bs mAb), was obtained by fusion of a murine hybridoma secreting a monoclonal antibody (mAb) specific for human fibrin with a murine hybridoma secreting a mAb against urokinase-type plasminogen activator (u-PA). The bs mAb (MA-FU1-74), purified to homogeneity from mouse ascitic fluid, migrated as a single band with apparent Mr 150,000 on nonreduced SDS-PAGE and had an affinity for both human fibrin (Ka = 2 x 10(7) M-1) and for u-PA (Ka = 10(8) M-1) comparable to that of the mAbs obtained from the respective parental hybridomas. MA-FU1-74 did not influence the enzymatic activity of two-chain u-PA (tcu-PA) towards plasminogen or towards a chromogenic substrate. The complex of MA-FU1-74 with recombinant single chain u-PA (rscu-PA) or with tcu-PA (urokinase) enhanced the fibrinolytic potency of the plasminogen activator towards clotted human plasma 20-fold and 5-fold, respectively. In a hamster pulmonary embolism model, the rscu-PA/MA-FU1-74 complex had a 13- to 17-fold increased thrombolytic potency (percent lysis per mg/kg u-PA administered) relative to that of rscu-PA. The specific thrombolytic activity (percent lysis per microgram/ml steady state plasma level of u-PA antigen) of the complex was, however, not significantly different from that of rscu-PA. The complex of rscu-PA with the parental anti-u-PA mAb (MA-UK1-3) had only a 2-fold enhanced thrombolytic potency relative to that of rscu-PA and had a 5-fold decreased specific thrombolytic activity. The plasma clearance rates of the complexes of rscu-PA with both MA-FU1-74 and MA-UK1-3 were about 10-fold lower than that of rscu-PA. In a rabbit jugular vein thrombosis model, the rscu-PA/MA-FU1-74 complex had a 4-fold enhanced thrombolytic potency, an unchanged specific thrombolytic activity and 20-fold reduced plasma clearance. In both animal models, the rscu-PA/MA-FU1-74 complex did not cause more extensive systemic activation of the fibrinolytic system than rscu-PA. It is concluded that the bispecific anti-fibrin/anti-u-PA mAb MA-FU1-74 targets u-PA to the fibrin clot, resulting in a significantly enhanced thrombolytic potency of the plasminogen activator.

Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Antibody Specificity; Cell Fusion; Cricetinae; Fibrin; Fibrinolytic Agents; Humans; Hybridomas; Jugular Veins; Mice; Molecular Sequence Data; Pulmonary Embolism; Rabbits; Thrombosis; Urokinase-Type Plasminogen Activator

The murine monoclonal antiplatelet antibodies MA-TSPI-1 (directed against human thrombospondin) and MA-PMI-2, MA-PMI-1, and MA-LIBS-1 (directed against ligand-induced binding sites [LIBS] on human platelet glycoprotein IIb/IIIa) were conjugated with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) using the cross-linking reagent N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The conjugates (rscu-PA/MA-TSPI-1, rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, and rscu-PA/MA-LIBS-1), purified by immunoadsorption and gel filtration, were obtained with recoveries of 34% to 45%, with an average stoichiometry of 1.6 to 1.8 IgG molecules per rscu-PA molecule, and with unaltered specific activities and affinities. Preincubation of human platelet-rich plasma with rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, or unconjugated rscu-PA resulted in partial inhibition of ADP-induced aggregation; 25% inhibition was obtained with 63 micrograms/mL rscu-PA and with 6 micrograms u-PA/mL rscu-PA/MA-PMI-2 or 1.2 micrograms u-PA/mL rscu-PA/MA-PMI-1. In an in vitro system composed of a 125I-fibrin-labeled platelet-rich human plasma clot immersed in normal human plasma, the conjugates had threefold to greater than 15-fold less fibrinolytic potency than unconjugated rscu-PA. The thrombolytic potency of rscu-PA/MA-PMI-1 and rscu-PA/MA-LIBS-1 was compared with that of rscu-PA and that of a control conjugate rscu-PA/MA-1C8 in a pulmonary embolism model in the hamster, using clots prepared from platelet-poor or platelet-rich human plasma. Lysis was measured 30 minutes after the end of a 60-minute intravenous infusion of the thrombolytic agents. rscu-PA, rscu-PA/MA-PMI-1, rscu-PA/MA-LIBS-1, as well as rscu-PA/MA-1C8 had comparable thrombolytic potencies (percent lysis per dose administered) towards platelet-poor human plasma clots. In contrast, the thrombolytic potency of rscu-PA/MA-PMI-1 and of rscu-PA/MA-LIBS-1 towards platelet-rich clots was 2.3- to 3-fold higher than that of rscu-PA (P less than .005) and fivefold to sevenfold higher than that of the control conjugate (P less than .01).

Topics: Adenosine Diphosphate; Animals; Antibodies, Monoclonal; Blood Platelets; Chemical Phenomena; Chemistry; Cricetinae; Cross-Linking Reagents; Fibrin; Fibrinolysin; Fibrinolysis; Fibrinolytic Agents; Humans; Kinetics; Plasminogen; Plasminogen Activators; Platelet Aggregation; Platelet Membrane Glycoproteins; Pulmonary Embolism; Recombinant Proteins; Thrombospondins; Urokinase-Type Plasminogen Activator

Topics: Adult; Aged; Aged, 80 and over; Erythrocyte Aggregation; Fibrin; Fibrinogen; Fibrinopeptide A; Humans; Methods; Middle Aged; Pulmonary Embolism; Thromboembolism

Indium-111-labeled monoclonal antibody 64C5 specific for the beta-chain of fibrin monomer was used to image canine (n = 6) experimental pulmonary emboli (at least one barium-thrombin and one copper-coil induced clot per dog). Uptake of 111In-64C5 and 125I-control-DIG26-11 were compared in 10 clots (7 barium-thrombin and 3 copper-coil) identified in the lungs. There was no difference in the blood clearance of 111In-64C5 and 125I-DIG26-11. Uptake of 111In-64C5 (0.183 +/- 0.105, mean %ID/g) was greater than 125I-DIG26-11 (0.024 +/- 0.025) in pulmonary clots (p less than 0.001). Mean thrombus to blood ratios at 24 hr were 6.78:1 for 64C5 and 0.57:1 for DIG26-11. The clots visualized in vivo were larger (0.315 +/- 0.381 g) than clots not visualized (0.089 +/- 0.098). Negative images were recorded in three dogs with pulmonary emboli, injected with 111In-labeled control monoclonal antibody 3H3. These data suggest that 111In-labeled antifibrin can detect large pulmonary emboli in vivo.

Topics: Animals; Antibodies, Monoclonal; Dogs; Fibrin; Indium Radioisotopes; Pulmonary Embolism; Radionuclide Imaging; Tissue Distribution

Cooperative effects of the prostacyclin analogue taprostene and the thrombolytic agent saruplase (r-scu-PA) were studied in anesthetized rabbits with pulmonary thromboembolism. Thrombolysis was evaluated as decrease of the total weight and of the incorporated 125J-fibrin-radioactivity of the embolized thrombi. Saruplase (10.0-46.4 micrograms/kg.min, i.v.) produced dose-dependent lytic effects. Taprostene, infused in a dose (0.1 microgram/kg.min, i.v.) that inhibited ADP-induced decrease of circulating platelets by 56%, reduced the total thrombus weight (p less than 0.05 vs control) and in combination it further augmented the saruplase (21.5 micrograms/kg.min)-induced thrombolysis (p less than 0.05 vs saruplase alone). Taprostene did not increase the spontaneous lysis rate of the incorporated 125J-fibrin (7.3 +/- 1.4% vs 8.1 +/- 1.4%), but further enhanced the fibrinolytic effect of saruplase (37.2 +/- 5.6% saruplase vs 53.6 +/- 2.3% saruplase + taprostene; p less than 0.05). This overadditive synergism is tentatively ascribed to the platelet inhibition by the prostacyclin analogue that may facilitate the action of the thrombolytic agent. Taprostene lowered mean arterial blood pressure by 22% in anesthetized rabbits; it did not significantly modify the slight decrease of the plasma fibrinogen level (20-30%) by 21.5 micrograms/kg.min saruplase. The results show that the prostacyclin analogue taprostene reduces the total thrombus weight and enhances the efficacy of the thrombolytic agent saruplase in pulmonary thromboembolism in rabbits.

Topics: Animals; Blood Pressure; Dose-Response Relationship, Drug; Drug Synergism; Epoprostenol; Fibrin; Fibrinogen; Infusions, Intravenous; Plasminogen Activators; Platelet Count; Pulmonary Embolism; Rabbits; Recombinant Proteins; Thrombolytic Therapy; Urokinase-Type Plasminogen Activator

We performed bronchoalveolar lavage (BAL) 0.5 to 24 h after thrombin-induced pulmonary microembolization in spontaneously breathing sheep to examine the inflammatory events that occur after pulmonary intravascular coagulation. Neutrophil alveolitis was evident as early as 0.5 h after microembolization and was maximal at 4 h (4.9 +/- 1.5% neutrophils of total BAL cells at baseline versus 26.2 +/- 2.8% at 4 h post-thrombin). Neutrophils obtained both at baseline (isolated from peripheral blood) and at 0.5 to 24 h after thrombin (isolated from BAL) did not demonstrate significant basal production of superoxide anion (O2-) and produced similar amounts of O2- upon challenge with phorbol myristate acetate (PMA) 200 micrograms/ml. The basal O2- production by alveolar macrophages was also not increased. However, alveolar macrophages recovered after fibrin microembolization produced greater amounts of O2- (29.1 +/- 6.3 nm O2-/10(6) cells at 0.5 h) after challenge with PMA compared with alveolar macrophages recovered prior to embolization (10.6 +/- 1.6 nm O2-/10(6) cells baseline), suggesting that thrombin-induced microembolization primes alveolar macrophages and enhances their O2- generation. Neutrophil chemotactic activity was detected in BAL fluid at 0.5 h post-microembolization and reached a peak level at 2 h. Alveolar macrophages were a source of the chemotactic activity since conditioned medium obtained from 2-h post-thrombin macrophages induced neutrophil chemotaxis, whereas baseline cells did not. The addition of the thrombin to macrophages did not result in the generation of chemotactic activity from baseline macrophages, indicating that macrophages were activated during the process of intravascular coagulation rather than by thrombin per se. Post-thrombin BAL fluid also stimulated O2- generation from sheep neutrophils.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Albumins; Animals; Bronchoalveolar Lavage Fluid; Cell Count; Fibrin; Macrophages; Neutrophils; Pneumonia; Pulmonary Embolism; Sheep; Superoxides

We assessed the efficacy and safety of peripheral intravenous recombinant human tissue-type plasminogen activator (rt-PA) in 47 patients with angiographically documented pulmonary embolism (PE). We administered 50 mg/2 h and, if necessary, an additional 40 mg/4 h. By 6 hours, 94% of the patients had angiographic evidence of clot lysis that was slight in 5, moderate in 12, and marked in 27 patients. Among the 34 patients with pulmonary hypertension prior to treatment, average pulmonary artery pressure decreased from 43/17 (27) to 31/13 (19) mm Hg (P less than 0.0001). The average lung scan perfusion defect decreased from 37% before therapy to 16% (P less than 0.01) after therapy among the 19 patients who had pre- and post-treatment lung scans. Of 7 patients with pre- and post-treatment imaging and Doppler echocardiograms, hypokinetic right ventricular wall movement (mild in 1, moderate in 2, and severe in 4) normalized in 5 and improved to mild hypokinesis in 2. Right ventricular diameter decreased from 3.9 +/- 1.0 to 2.0 +/- 0.5 cm (P less than 0.005). Fibrinogen decreased 33% from baseline at 2 h and 42% from baseline at 6 h. However, patients with the greatest degree of angiographic clot lysis at 2 h had a preponderance of fibrinogenolysis over fibrinolysis, demonstrated by a lower ratio of cross-linked fibrin degradation products to fibrin(ogen) degradation products (0.14 +/- 0.09 vs. 0.54 +/- 0.82) (P less than 0.04). Among selected patients, peripheral intravenous rt-PA is associated with rapid lysis of PE, improved pulmonary perfusion, and improved right ventricular function.

Topics: Biomarkers; Fibrin; Fibrinogen; Humans; Pulmonary Artery; Pulmonary Circulation; Pulmonary Embolism; Radiography; Recombinant Proteins; Tissue Plasminogen Activator

Indices of fibrinogen cleavage by thrombin (fibrinopeptide A, FPA); by plasmin (BB1-42 and serum FDP); of the platelet release reaction (beta thromboglobulin and platelet factor 4); and antithrombin III (AT III) levels were measured serially in 46 patients with pulmonary emboli in whom either substantial (SR) or impaired (IR) resolution was documented. The mean FPA level in the 25 patients with IR was significantly higher than the level in the 21 patients with SR (p less than 0.01). The increased thrombin activity in the IR group was not due to AT III deficiency or increased platelet reactivity but the elevated FPA levels in the presence of therapeutic levels of anticoagulation indicated that the dose of heparin was inadequate. The higher BB1-42 and FDP levels in this group reflected the increased plasmin activity that follows increased thrombin activity. In a multivariate discriminant analysis, only the FPA data could be used to predict the degree of resolution. Increased thrombin action impairs resolution presumably by producing greater amounts of accreted fibrin on the impacted embolus.

Topics: Antithrombin III; beta-Thromboglobulin; Fibrin; Fibrinogen; Fibrinolysin; Fibrinopeptide A; Heparin; Humans; Platelet Aggregation; Platelet Factor 4; Pulmonary Embolism; Thrombin

The effects of fibrin microembolism were examined using an infusion of a prothrombin activator (Echis carinatus venom, ECV; 30 min, 0.5 NIH thrombin equivalent units/kg) in acute mongrel dogs prepared with a pulmonary lymph cannula (n = 6, 12.3-21.5 kg). Lymph flow increased approximately 2.5-fold after 1-1.5 hr of elevated left atrial pressure (Pla = 20 cm H2O; 26 +/- 7 to 63 +/- 16 microliter/min, P less than 0.01) and the plasma to lymph protein concentration ratio (CP/CL) declined from 0.66 +/- .04 to 0.54 +/- .16 (P less than 0.01, x +/- SE). After Pla was reduced to control levels, the initiation of fibrin microembolism was associated with an approximate 2.7-fold elevation of lymph flow (62 +/- 8 microliters/min, P less than 0.01) and the CP/CL was not changed (0.56 +/- 0.04, P = ns). When Pla was increased following microembolism, lymph flow more than doubled to 117 +/- 24 microliter/min (P less than 0.01) and the CP/CL remained unaltered (0.56 +/- 0.03, P = ns). These changes were associated with afibrinogenemia and the appearance of fibrin degradation products (FDP) in plasma (150 +/- 50 micrograms/ml) and lymph (80 micrograms/ml) in three of the animals tested. No consistent pattern was seen in the CL/CP of separate endogenous plasma proteins after each intervention. These data support the view that pulmonary fibrin microembolism without inhibition of the fibrinolytic system was associated with an early increased pulmonary microvascular permeability to protein. In a separate group of similarly prepared animals (n = 8, 13-21.5 kg) without a lymph catheter, scanning electron microscopic observations showed branching fibrin microemboli to partially occlude some pulmonary arterioles. Mixed thrombus formations in larger precapillary blood vessels were also seen. Ultrastructural observations revealed the deposition of fibrin strands (periodicity = 220-230 A) within the pulmonary capillaries. Some of these deposits were overlaid by lamellar pseudopodia from endothelial cells and the fibrin appeared to be within these cells. Although plasmalemmal vesicles seemed to be more numerous in the endothelial cells with adjacent fibrin deposits, no gaps or breaks were seen in the densely stained interendothelial cell junctions and/or the endothelial cell membrane of the affected lung capillaries. Activated neutrophils and platelets were more numerous in the pulmonary capillaries following EVC. These data suggest that the presence of FDP and/or fibrin deposits wi

Topics: Animals; Blood Pressure; Capillaries; Capillary Permeability; Dogs; Electrophoresis, Polyacrylamide Gel; Endopeptidases; Endothelium; Fibrin; Hemodynamics; Lung; Lymphatic System; Microcirculation; Microscopy, Electron, Scanning; Plasma; Pulmonary Artery; Pulmonary Embolism; Structure-Activity Relationship

We studied the effects of crystalloid (75 ml/kg of Ringer's lactate) or colloid (6% dextran-70, 6% hydroxyethyl starch, or 25 ml/kg of 5% human serum albumin) fluid infusions or no treatment (control) on the calculated lung capillary (Pc)-plasma oncotic pressure (pi c) gradient and pulmonary edema. Two sets of mongrel dogs were studied: uninjured (n = 25; 14 to 22 kg) and pulmonary fibrin-microembolized (n = 25; 15 to 23 kg). In both sets of experiments, left atrial pressure was controlled (15 mm Hg) throughout the 4-h plus experimental period. In the uninjured set, the Pc-pi c gradient averaged +1.0 and -0.2 mm Hg in the hydroxyethyl starch and dextran groups, +0.7 and +2.3 mm Hg in the human serum albumin and control groups, and +6.2 mm Hg in the Ringer's lactate group. In the fibrin-microembolized group, this gradient averaged 2.6, 2.4, 3.0, 5.3, and 9.5, respectively. The extravascular lung water to bloodless dry lung wet weight ratios in the no-fluid treatment group of the uninjured and microembolism groups with increased pressure (3.8 +/- 0.3 to 4.1 +/- 0.4 [SEM]; NS) are consistent with interstitial or perivascular edema. There were, however, no significant differences noted between the respective control groups or any fluid treatment group in either set of experiments. These data support the view that infusion of either colloid or crystalloid solutions in normal or pulmonary fibrin-microembolized lungs does not produce sufficient change in the Pc-pi c gradient to elevate edemagenesis when pulmonary capillary pressure is limited to 22 mm Hg in dogs.

Topics: Animals; Blood Gas Analysis; Body Water; Colloids; Crystallization; Dogs; Fibrin; Fluid Therapy; Hemodynamics; Isotonic Solutions; Lung; Pulmonary Artery; Pulmonary Edema; Pulmonary Embolism; Ringer's Lactate; Solutions

Fibrin is often seen occluding the lung vessels of patients dying from ARDS and is surrounded by regions of lung necrosis. To learn if we could observe increased or focal fibrin deposition and assess the kinetics of plasma fibrinogen turnover during severe acute respiratory failure, we injected technetium 99m-labeled human purified fibrinogen (Tc-HF) and used gamma camera scanning for as long as 12 h in 13 sequential patients as soon as possible after ICU admission. The fibrinogen uptake rates were determined by calculating the lung:heart radioactivity ratios at each time point. Slopes of the lung:heart ratio versus time were compared between ARDS and mild acute respiratory failure (ARF). The slope of the lung:heart Tc-HF ratio of the 9 patients with ARDS (2.9 +/- 0.4 units) was markedly higher (p less than 0.02) than the slope of the 4 patients with mild ARF (1.1 +/- 0.4) and the 3 patients studied 5 to 9 months after recovery from respiratory failure (0.7 +/- 0.07). In the 1 patient with ARDS and the 2 patients with mild ARF studied both during acute lung injury and after recovery, the lung:heart Tc-HF ratio had decreased at recovery. To compare the pulmonary uptake of Tc-HF to 99mTc-labeled human serum albumin (Tc-HSA), 5 patients were injected with 10 mCi of Tc-HSA, and scanning of the thorax was performed with a similar sequential imaging protocol 24 h after conclusion of the Tc-HF study.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Aged; Female; Fibrin; Fibrinogen; Hemodynamics; Humans; Lung; Male; Middle Aged; Organotechnetium Compounds; Pulmonary Artery; Pulmonary Embolism; Radiography; Radionuclide Imaging; Respiratory Distress Syndrome; Technetium; Technetium Tc 99m Aggregated Albumin; Time Factors

The article reports on measurements of D dimer, a terminal plasmic lysis product of crosslinked fibrin, with an enzyme immunoassay (ELISA) employing recently developed specific monoclonal antibodies. Due to its sensitivity the test can be used on plasma samples. The D dimer concentrations in patients with deep vein thrombosis diagnosed by laboratory apparatus were significantly increased compared to a control group; in one patient with additional pulmonary embolism, the level was even higher. Moderately elevated concentrations of D dimer were observed in the hypercoagulable state of pregnancy, puerperium and during the postoperative course. This reduces the specificity of the test with regard to the recognition of thromboembolic episodes under these conditions. Obstetric patients with disseminated intravascular coagulation (DIC) showed excessively increased levels of D dimer. Hence, a marker function with regard to the recognition of thromboembolic disease can be attributed to the D dimer; the diagnosis of DIC can be confirmed if very high concentrations are detected.

Topics: Adult; Antibodies, Monoclonal; Antibody Specificity; Disseminated Intravascular Coagulation; Enzyme-Linked Immunosorbent Assay; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Ovarian Neoplasms; Pregnancy; Pregnancy Complications; Pregnancy Complications, Cardiovascular; Pregnancy Complications, Hematologic; Pregnancy Complications, Neoplastic; Pulmonary Embolism; Thrombophlebitis

Seventy-five intimal arterial thickenings (from 58 subjects) related to pulmonary emboli were examined. Many showed residua derived from the emboli (fibrin, platelets, haemosiderin) and proliferation of elastica and smooth muscle cells. Features resembling those of atherosclerosis were the frequent presence of extracellular lipid and apolipoprotein-B containing lipoproteins (LpB) which corresponded closely in distribution; and (in about 40% of the thickenings) collections of fat-filled (foam) cells. Platelet antigens were often detected within foam cells in some cases, in company with LpB. The results indicate that at least some intimal thickenings originating from pulmonary emboli undergo transformation to atherosclerotic plaques. The role of pulmonary hypertension in the process was investigated. Mechanisms relevant to this transformation and to theories of atherogenesis are discussed.

Topics: Adolescent; Adult; Aged; Apolipoproteins B; Arteriosclerosis; Blood Platelets; Female; Fibrin; Fibrinogen; Foam Cells; Humans; Hypertension, Pulmonary; Lipid Metabolism; Lung Diseases; Male; Middle Aged; Pulmonary Embolism; Time Factors

Many authors have advocated glucocorticoids for prophylaxis against or treatment of Adult Respiratory Distress Syndrome (ARDS) or post-traumatic pulmonary microembolism. One of the theories underlying this advocacy is that the activation of the complement system possibly is preventable by pharmacologic doses of corticosteroids. Studies on traumatized patients are difficult to standardize, and clinical observations are correspondingly difficult to evaluate. Animal models for study of the microembolism syndrome have often comprised too short a time and most have greatly differed from the clinical situation. We have earlier evolved an experimental model by means of which changes identical to the microembolism syndrome can be induced from a reproducible musculo-skeletal trauma in pigs observed under long-term anesthesia under standardized conditions. In this study, early and long-term effects of corticosteroids on the course of post-traumatic microembolism was evaluated by following the pulmonary function and X-ray appearance, pulmonary trapping of platelets and fibrin and histologic changes in pigs, using this standardized trauma model. Methylprednisolone sodium succinate (30 mg/kg bw) was given to 9 pigs one hour after trauma and thereafter every 8th hour during a 72 hour observation period. Two other groups of animals were used for comparison, 13 traumatized, non-treated and 15 non-traumatized, non-treated pigs. Intrapulmonary microembolism was measured quantitatively by repeated external detection of labelled platelets (51Cr) and fibrinogen (125I), sequential chest X-rays and morphologic examination of the lungs post mortem.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Drug Administration Schedule; Female; Fibrin; Fibrinogen; Hemodynamics; Lung; Male; Methylprednisolone; Methylprednisolone Hemisuccinate; Oxygen; Oxygen Consumption; Platelet Count; Pulmonary Embolism; Respiratory Distress Syndrome; Shock, Traumatic; Swine

A new method is described for identifying low concentrations of circulating derivatives of fibrinogen and fibrin, even when present in heterogeneous mixtures. This technique is applicable to plasma and serum and uses electrophoresis in 2% agarose in the presence of sodium dodecyl sulfate (SDS) followed by immunological identification of separated derivatives, using radiolabeled antifibrinogen antiserum and autoradiography. Unique electrophoretic patterns distinguish plasmic derivatives of crosslinked fibrin from those of fibrinogen and also identify crosslinked fibrin polymers produced by the combined action of thrombin and factor XIII on fibrinogen. The assay is sensitive to a concentration of 0.1 micrograms/mL of fibrinogen in serum or plasma. Fibrin polymers, plasmic degradation products of fibrinogen, and plasmic degradation products of crosslinked fibrin were detected in the plasma or serum of a patient with disseminated intravascular coagulation. Plasmic derivatives of both fibrinogen and crosslinked fibrin appeared in serum in the course of fibrinolytic therapy for pulmonary embolism, whereas during acute myocardial infarction a marked increase in the proportion of fibrin polymers in plasma was found in comparison with normal controls. Thus, the procedure can distinguish between the simultaneous processes of fibrin polymer formation, fibrinogenolysis, and fibrinolysis, and is sufficiently sensitive to detect relevant quantities of derivatives in pathologic conditions.

Topics: Autoradiography; Electrophoresis, Agar Gel; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysis; Humans; Molecular Weight; Pulmonary Embolism; Urokinase-Type Plasminogen Activator

Fibrinogen degradation, fibrin polymerisation, and the insertion of cross links into fibrin by fibrin stabilising factor lead to the appearance of new antigenic determinants. Antibodies against these antigenic sites may react specifically with the derivatives but not with the parent molecules. We have utilised a monoclonal antibody, which interacts with the cross linked fragment D dimer and related high molecular weight fibrin derivatives, to develop an enzyme immunoassay which measures cross linked fibrin derivatives in plasma and serum using D dimer as standard. Mean concentration in plasma from normal subjects was 75 ng/ml with an upper limit of about 144 ng/ml. Concentrations in patients with pulmonary embolism, deep venous thrombosis, arterial thromboembolism, and disseminated intravascular coagulation were raised in all cases. Confirmation of the specific increase of cross linked fibrin derivatives in patients with disseminated intravascular coagulation was obtained by parallel monitoring of their fibrin degradation products in serum using affinity chromatography and sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. In many patients the plasma concentrations greatly exceeded the serum values of cross linked fibrin degradation products, suggesting that the procedure can measure fibrin derivatives in plasma which are absent from serum.

Topics: Antibodies, Monoclonal; Chromatography, Affinity; Cross-Linking Reagents; Disseminated Intravascular Coagulation; Electrophoresis, Polyacrylamide Gel; Epitopes; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Pulmonary Embolism; Thrombosis

Topics: Disseminated Intravascular Coagulation; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysin; Fibrinolysis; Glomerulonephritis; Hemostasis; Humans; Liver Cirrhosis; Postoperative Complications; Pulmonary Embolism; Thrombin; Thromboembolism; Thrombophlebitis

We produced pulmonary fibrin microembolism using an infusion of a prothrombin activator (Echis carinatus venom, 30 min, 0.5 NIH thrombin equivalent units/kg) in open-chest mongrel dogs. To determine the nonclotting effects of this venom on edemagenesis we infused an irreversible thrombin inhibitor, D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (PPACK, 57 nmol X kg-1 X min-1 for 120 min), alone (n = 5) or with venom (Echis + PPACK, n = 5). The control group (n = 5) was given 1 ml of 0.9% NaCl. A decline in left atrial pressure (means +/- SE, 5.3 +/- 0.4 to 4.0 +/- 0.5 mmHg, P less than 0.05) and cardiac index (149 +/- 10 to 82 +/- 13 ml X min-1 X kg-1, P less than 0.01) in association with a marked increase in pulmonary arterial pressure (14.5 +/- 0.6 to 26.6 +/- 2.5 mmHg, P less than 0.001) and pulmonary vascular resistance (64 +/- 5 to 304 +/- 42 mmHg X ml-1 X min-1 X kg-1, P less than 0.001) was observed after 20 min of venom infusion. During this interval, pulmonary artery wedge pressure increased (4 +/- 1 to 12 +/- 4 mmHg, P less than 0.01) in four of eight animals. Fibrinogen declined below measurable levels and fibrin microemboli were seen in many pulmonary arterioles. These changes were not observed in the Echis + PPACK, PPACK, or control groups. Leukopenia and thrombocytopenia were observed in the Echis and Echis + PPACK groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amino Acid Chloromethyl Ketones; Animals; Body Water; Disease Models, Animal; Dogs; Fibrin; Fibrinogen; Hemodynamics; Leukocyte Count; Lung; Platelet Count; Pulmonary Embolism; Respiration; Thrombin; Viper Venoms

Pulmonary megakaryocytes and fibrin microthrombi were counted in lung sections from 22 patients dying from extensive burns. There was a significant correlation between numbers of megakaryocytes and fibrin microthrombi, supporting a relationship between disseminated intravascular coagulation (DIC) and numbers of pulmonary megakaryocytes. No correlation was found between antemortem platelet counts and either fibrin microthrombi or megakaryocytes. Possible explanations for this are forwarded and the nature of pulmonary megakaryocytes discussed.

Topics: Adult; Aged; Burns; Cell Count; Disseminated Intravascular Coagulation; Fibrin; Humans; Lung; Megakaryocytes; Middle Aged; Pulmonary Embolism; Respiratory Distress Syndrome

A total of 250 subjects were investigated using a diagnostic search flow-chart. Pulmonary artery thromboembolism (PATE) was diagnosed in 102 patients. The results have demonstrated the value of laboratory tests employed--markers of thrombin- and plasminemia and platelet activation--for PATE diagnosis. To diagnose PATE, levels of fibrinogen-fibrin and beta-thromboglobulin degradation products should be measured in myocardial infarction patients, and plasma soluble fibrin measurement should be added to those in patients with circulatory insufficiency. In recurrent PATE, continuous increase of plasma beta-thromboglobulin and soluble fibrin levels, antithrombin III exhaustion and reduced levels of fibrinogen-fibrin degradation products are of diagnostic value.

Topics: Antithrombins; beta-Thromboglobulin; Disseminated Intravascular Coagulation; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Pulmonary Embolism

Topics: Animals; Blood Pressure; Dogs; Fibrin; Humans; Models, Biological; Molecular Weight; Peptides; Pulmonary Edema; Pulmonary Embolism; Rats; Respiratory Insufficiency

Clinical and autopsy studies have shown an association between pulmonary microembolism and acute respiratory failure after trauma or sepsis. Prophylaxis and treatment with the aim of decreasing the fibrin deposition in the lungs were associated with a decrease in the incidence and death rate of this syndrome. Small fibrin degradation products (peptides) are accumulated in the lungs and are only slowly cleared from this organ, especially during states of fibrinolysis inhibition. These peptides may contribute to the pulmonary damage in several ways. They act by interfering with other vasoactive substances as bradykinin, histamine and products of the arachidonic acid cascade. Products of the cyclooxygenase pathways as thromboxane A2 play a major role in early microembolism whereas lipoxygenase products seem to be involved in delayed microembolism. Pulmonary microembolism thus seems to be one important, but certainly not the only pathogenetic factor in acute "idiopathic" respiratory failure. Other factors such as pulmonary contusion, aspiration of gastric contents or blood, or oxygen toxicity, might well be contributory in some cases. Pulmonary microemboli containing fibrin and leukocytes are probably also involved as contributory agents in some cases in the large group of acute respiratory failure due to "known factors".

Topics: Acute Disease; Animals; Disseminated Intravascular Coagulation; Dogs; Fibrin; Fibrinolysis; Humans; Lung; Pulmonary Embolism; Rats; Respiratory Insufficiency

We examined the relationship between the activation of fibrinolysis and the increase in lung vascular permeability after pulmonary microembolization (PM). Sheep were prepared with lung lymph fistulas to assess pulmonary transvascular fluid and protein dynamics. Studies were made in three groups: group I (n = 8) in which PM was induced by an iv infusion of thrombin (60 +/- 13 NIH U/kg); group II (n = 7) in which PM was induced by an iv infusion of 50-micrometers-diameter fibrin microaggregates (0.32 +/- 0.009 g/kg); and group III in which the left atrial pressure was increased by 10-15 Torr by inflation of a balloon catheter. Thrombin caused an increase in pulmonary lymph flow (Qlym) without a change in the lymph-to-plasma protein concentration ratio (L/P ratio) indicating an increase in the lung vascular permeability to proteins. Fibrin microaggregates also increased Qlym, but the increase was associated with a decrease in the L/P ratio. The results in the latter group were similar to those obtained after left atrial hypertension in normal sheep. The increase in permeability after PM induced with thrombin was associated with large increases in the plasma concentration of fibrin degradation products, as compared with PM induced by fibrin microaggregates. The process of intravascular coagulation with the resultant generation of fibrinolysis and fibrin degradation products may be required for the increase in lung vascular permeability to proteins after pulmonary microembolization.

Topics: Animals; Blood Pressure; Blood Proteins; Fibrin; Hemodynamics; Homeostasis; Lung; Lymph; Proteins; Pulmonary Embolism; Sheep; Thrombin; Water-Electrolyte Balance

Topics: Animals; Capillary Permeability; Dogs; Fibrin; Humans; Peptides; Pulmonary Embolism; Respiratory Distress Syndrome

Based on literature reports suggesting the possible incorporation of Tc-99m sulfur colloid (Tc-SC) into fibrin deposits, this study was undertaken to evaluate the potential of this radiopharmaceutical as an imaging agent in thromboembolic disease. Animal models of deep-vein thrombosis and pulmonary embolism were used. The mean thrombus-to-blood (T/B) uptake ratios were comparable for fresh and older thrombi (up to 72 hr). Thrombus uptake was significantly lower in a group of five control dogs that received pertechnetate instead of Tc-SC. Intravenous heparin administration (5,000 IU) 2 hr before injection of Tc-SC caused a depression in T/B ratios but did not totally block Tc-SC uptake. Gamma imaging with Tc-SC allowed demonstration of deep-vein thrombi, but imaging of pulmonary emboli as areas of increased activity was not satisfactory. This study supports the concept of thrombus detection with radiolabeled particles but not the extension of this principle to the imaging of pulmonary emboli.

Topics: Animals; Colloids; Dogs; Evaluation Studies as Topic; Fibrin; Heparin; Lung; Pulmonary Embolism; Radionuclide Imaging; Sulfur; Technetium; Thromboembolism; Thrombosis; Time Factors

A method for continuous monitoring of microthrombosis in the lungs is described. After injection of labelled fibrinogen and platelets the accumulation of these blood constituents was estimated during experimental disseminated intravascular coagulation (DIC) by radioactivity measurement on the body surface. By optimizing the measuring geometry of a single hole collimator for scintillation probes a high relative efficiency was attained and a defined area of the lung was viewed. This method allows recording of the trapping of fibrin and platelets in the lungs in experimental DIC and investigations on the pharmacological control of this condition.

Topics: Animals; Blood Coagulation; Blood Platelets; Chromium Radioisotopes; Disease Models, Animal; Female; Fibrin; Iodine Radioisotopes; Monitoring, Physiologic; Platelet Count; Pulmonary Circulation; Pulmonary Embolism; Rats; Scintillation Counting

We determined the effects of chronic fibrinogen depletion on the development of pulmonary edema after pulmonary microembolization. Dogs were defibrinogenated with a purified fraction of Malayan pitviper venom (ancrod). Studies were made in four groups: control untreated (group I); emboli untreated (group II); control defibrinogenated (group III); and emboli defibrinogenated (group IV). Fibrinogen decreased (P < 0.05) from 570.6 +/- 100.9 to 5.3 +/- 3.1 mg/100 ml in the ancrod-treated groups. Pulmonary arterial pressure was increased to similar levels in both embolized groups after infusion of 100-mug-diam nonsiliconized glass beads into the right atrium. Pulmonary vascular resistance and pulmonary perfusion pressure were initially increased to similar levels in both embolized groups, but by 75 min postembolization (PE) both parameters were higher (P < 0.05) in the defibrinogenated group. The extravascular lung water-to-bloodless dry lung ratio at 75 min PE of 4.53 +/- 0.24 in group II was greater than the control value of 2.84 +/- 0.22 in group I (P < 0.05). In contrast, the extravascular lung water-to-bloodless dry lung ratio of 3.64 +/- 0.09 in group IV was not different from the control value of 3.38 +/- 0.04 in group III, but was less than 4.53 +/- 0.24 in group II (P < 0.05). Therefore, chronic defibrinogenation in dogs prevented the development of pulmonary edema after pulmonary microembolization. The protective effect may be due to inhibition of the increase in lung vascular permeability and to a time-dependent reduction in pulmonary microvascular pressure.

Topics: Animals; Blood Cell Count; Blood Platelets; Body Water; Dogs; Fibrin; Fibrinogen; Leukocyte Count; Lung; Pulmonary Embolism; Time Factors

Blood tests for fibrinogen/fibrin degradation products (FDP/fdp) and soluble fibrin complexes (SFC) were performed in 100 patients at high risk for thromboembolism in order to assess the diagnostic value of these determinations in patients suspected to have pulmonary embolism. Tests were positive significantly less often in high-risk patients, and mean values were significantly lower, when compared with patients with established pulmonary embolism (P less than .001). However, no significant differences existed between high-risk patients and patients with deep venous thrombosis of the legs. Positivity rates and mean values were significantly higher in the presence of pulmonary embolism than in patients with deep venous thrombosis alone (P less than .05). Elevated FDP/fdp and SFC values are useful in the diagnosis of pulmonary embolism in high-risk patients; moreover, positive results in a patient with deep venous thrombosis suggests that pulmonary embolism has occurred.

Topics: Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Pulmonary Embolism; Risk; Thrombophlebitis

Topics: Animals; Body Weight; Dogs; Fibrin; Hemodynamics; Iodine Radioisotopes; Lung; Organ Size; Pulmonary Edema; Pulmonary Embolism; Time Factors; Tranexamic Acid

The surface of the leaflets of orthotopic transplanted glutaraldehyd-conditioned conus-pulmonalis xenografts show when analysed by a scanning microscope the following constant changes. Within seconds the surface of the leaflets is covered by a grainy layer of proteins followed by fibrin threads. Cellular elements of the blood--like platelets, white blood cells, macrophages and microthrombi--are incorporated in the fibrin network. This leads, after several weeks to a fibrous layer especially over the stiff parts of the valve. No endothelium was seen even after 6 months.

Topics: Animals; Bioprosthesis; Blood Cells; Blood Proteins; Dogs; Fibrin; Heart Valve Prosthesis; Microscopy, Electron, Scanning; Pulmonary Embolism; Pulmonary Valve; Swine; Time Factors; Transplantation, Heterologous

The effect of acute haemorrhage on the deposition and clearance of fibrin in the rat lung after thrombin-induced intravascular coagulation was investigated. Haemorrhage was followed by less embolization of fibrin to the lungs and delayed elimination from the lungs. As lung tissue fibrinolysis was not diminished, the peripheral and pulmonary circulatory disturbance was probably in itself responsible for the observed effects.

Topics: Acute Disease; Animals; Female; Fibrin; Fibrinogen; Fibrinolysis; Lung; Pulmonary Circulation; Pulmonary Embolism; Rats; Shock, Hemorrhagic; Thrombin

Fibrinogen-fibrin-related antigen (FR antigen) was isolated from as little as 1 ml of human plasma by immuno-affinity chromatography with agarose-bound antibody to human fibrinogen. N-terminal analysis was performed to determine the nature and extent of proteolytic degradation of the FR antigen in patients with disseminated intravascular coagulation and in normal subjects. Thrombin cleavage of the A- and B-peptides from fibrinogen in vitro was monitored by the appearance of N-terminal glycine, and an increase in glycine was shown in the FR antigen of patients with disseminated intravascular coagulation. As plasmin progressively degraded fibrinogen, increases in N-terminal alanine, aspartic acid and lysine were observed, corresponding to the known plasmin-cleavage points of fibrinogen; increases in these N-terminal amino acids were also found in the patients' FR antigen. Thrombin treatment in vitro was used to remove fibrinopeptide A (N-terminal alanine) from the samples and to reflect specifically the N-terminal alanine at the plasmin-cleavage point (Arg-42-Ala-43) of the B beta-chain on assay; this alanine was increased progressively in the FR antigen of a patient during urokinase therapy, and was high in other patients when the FR antigen was examined by this procedure.

Topics: Alanine; Amino Acid Sequence; Antigens; Disseminated Intravascular Coagulation; Electrophoresis, Polyacrylamide Gel; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Pulmonary Embolism; Thrombin; Urokinase-Type Plasminogen Activator

Topics: Adult; Aged; Endopeptidases; Female; Fibrin; Fibrinolysis; Humans; Male; Middle Aged; Plasminogen; Pulmonary Embolism; Thrombin; Urokinase-Type Plasminogen Activator

Investigations were carried out to determine the lung lesions responsible for the development of pulmonary heart disease, cor pulmonale, in rats treated with monocrotaline pyrrole or monocrotaline. Animals with right ventricular hypertrophy showed microscopic lung alterations consisting of alveolar edema; fibrin thrombi with partial to complete occlusion of arteries, arterioles, capillaries, and veins; connective tissue proliferation of alveolar septae; cellular hyperplasia of septae; and medial hypertrophy of arterioles. Due to the high incidence of fibrin thrombi in animals with right ventricular hypertrophy, we believe that formation of fibrin thrombi plays a decisive role in the development of chemically induced cor pulmonale.

Topics: Animals; Cardiomegaly; Endothelium; Fibrin; Hypertension, Pulmonary; Lung; Male; Monocrotaline; Pulmonary Embolism; Pulmonary Heart Disease; Pyrroles; Pyrrolizidine Alkaloids; Rats

Fibrinogen/fibrin degradation products (FDP/fdp) and soluble fibrin complexes (SFC) were measured serially in 60 patients heparinized for pulmonary embolism or deep venous thrombosis. Eight patients had recurrent thromboembolism. In patients without recurrence, FDP/fdp and SFC tended to normalize within three to five days. In patients with recurrence, results of both tests were significantly higher on admission, and FDP/fdp values were significantly higher throughout ten days of therapy, than in patients without recurrence. The SFC values were not different between the two groups during the first six days of treatment, but again became significantly higher on the seventh day in patients with recurrence. There were no differences in clotting times, heparin dosage, or any other clinical features between patients with and without recurrence. Measurement of FDP/fdp and SFC can help identify patients at risk of recurrent thromboembolism if performed serially during treatment.

Topics: Fibrin; Fibrin Fibrinogen Degradation Products; Heparin; Humans; Pulmonary Embolism; Recurrence; Risk; Thromboembolism; Thrombophlebitis

The subunit fibrin composition of thrombi of both venous and arterial origin was examined by sodium dodecyl sulphate gel electrophoresis. The thrombi were recovered by surgical intervention and all had the same fibrin subunit composition. The alpha chains were cross-linked as alpha-chain polymers alpha (p), the gamma chains as gamma-chain dimers (gamma-gamma) while the beta chains were not crosslinked; a further subunit of molecular weight 33 000 was shown to be present in all the fibrins examined and was a degradation fragment of the beta or gamma chains. This data suggests that the crosslinked alpha chains are rate limiting to the lysis of thrombi in vivo. The digestion of pulmonary emboli by plasmin yielded soluble degradation products which were identified as D dimer and E, the latter fragments being the major products obtained by the lysis of in-vitro made plasma clots. The similarity of the composition and lysis of thrombus fibrin to that formed in vitro augurs well for the justification of in-vitro research on mechanisms in thrombolysis.

Topics: Electrophoresis, Polyacrylamide Gel; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysin; Humans; Immunoelectrophoresis, Two-Dimensional; Molecular Weight; Peptides; Pulmonary Embolism; Thromboembolism; Thrombophlebitis

Forty-two patients underwent open-lung biopsy during the early phase of acute respiratory insufficiency. Correlation between the gross appearance of the lung at operation and the microscopic findings was good. Although only fair correlation was found between lung and tracheal cultures, the findings of two positive cultures in the lung only was of utmost importance. Biopsying multiple areas from the same operation showed identical pathology in 86 per cent of cases. The mortality rate of open-lung biopsy was zero; the morbidity rate was 4 per cent. The over-all survival rate of acute respiratory insufficiency (ARI) due to trauma was 39 per cent; that of pneumonia, 11 per cent. In 17 (33 percent) patients specific diagnoses and/or specific therapies were employed as a direct result of the biopsy or the thoracotomy. The incidence and prognostic implications of fibrosis and microthromboembolism are presented and discussed. Open-lung biopsy has been extremely safe and valuable in characterizing and managing ARI.

Topics: Acute Disease; Biopsy; Fibrin; Fibrinogen; Fluorescent Antibody Technique; Humans; Lung; Pulmonary Embolism; Pulmonary Fibrosis; Respiratory Insufficiency

To help differentiate pulmonary embolism from other lung diseases, we measured the degradation products of fibrinogen and fibrin and soluble fibrin complexes in normal control subjects and patients with pulmonary embolism, lung cancer, pneumonia, chronic obstructive pulmonary disease, tuberculosis, asthma, and several miscellaneous disorders. A separate group of patients, who were suspected of having pulmonary embolism but had negative pulmonary angiography, were also tested. Many nonthromboembolic lung diseases frequently were associated with positive fibrinogen/fibrin degradation products or soluble fibrin complexes, but those with high positivity rates for one test tended to have low rates for the other test. Both fibrinogen/fibrin degradation products and soluble fibrin complexes were positive in 55 per cent of patients with pulmonary embolism but only in 4 per cent with nonthromboembolic conditions (P less than 0.001), in 7 per cent of patients with negative pulmonary angiography (P less than 0.001), and in none of the normal subjects (P less than 0.001). Both tests were negative in only 3 per cent of patients with pulmonary embolism but in 35 per cent of nonthromboembolic diseases (P less than 0.005), 54 per cent of those with negative pulmonary angiography (P less than 0.001), and 79 per cent of normal control subjects (P less than 0.001). The combination of fibrinogen/fibrin degradation products and soluble fibrin complexes is more valuable than either test alone in the diagnostic separation of thromboembolic from nonthromboembolic pulmonary diseases.

Topics: Diagnosis, Differential; False Positive Reactions; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Humans; Lung Diseases; Pulmonary Artery; Pulmonary Embolism; Radiography

Levels of fibrin(ogen) degradation products (F.D.P.) have been measured by radioimmunoassay for degradation product E (FgE) and by tanned-red-cell haemagglutination-inhibition immunoassay (T.R.C.H.I.I.) in the serum of thirty-three patients undergoing total hip replacement. Levels of F.D.P. did not correlate with thermographic evidence of deep-venous thrombosis. However, in 34 patients with pulmonary embolism, levels of F.D.P. measured by the T.R.C.H.I.I. were transiently raised at the time of embolus, and FgE concentrations were increased for up to 5 days preceding the embolus. Since the measurments of FgE is simple, convenient, and cheap, this estimation might constitute a valuable screening test for major thromboembolic episodes in the postoperative period.

Topics: Aged; Fibrin; Fibrinogen; Fibrinolysis; Hemagglutination Inhibition Tests; Hip; Humans; Middle Aged; Phlebography; Postoperative Complications; Pulmonary Embolism; Radioimmunoassay; Thermography; Thrombophlebitis

The microembolism syndrome occurred in four patients out of a series of 15 patients with multiple injuries who were considered to run a risk of developing this syndrome. These four patients showed signs of fibrin trapping in the lungs, as demonstrated by the use of 125I-labelled fibrinogen and external detection over the lungs. It is, therefore, considered that this method can be used for diagnosing the microembolism syndrome. The fibrin trapping occurred at the onset of the progressive respiratory insufficiency. The time relation between the uptake of fibrin and the onset of the progressive respiratory insufficiency supports the theory of a causal connection between fibrin and pulmonary damage. Measurements of different coagulation and fibrinolysis factors in the blood were not able to discriminate between patients who developed the microembolism syndrome and those who did not.

Topics: Adolescent; Adult; Aged; Blood Cell Count; Blood Platelets; Female; Fibrin; Fibrinogen; Humans; Iodine Radioisotopes; Lung; Male; Middle Aged; Oxygen; Partial Pressure; Pulmonary Embolism; Time Factors

The mechanism and significance of elevated levels of serum fibrin degradation products (FDP) in pulmonary embolism were investigated experimentally. Dogs were embolized with autologous blood clot-incorporating canine 125I-fibrin and were infused with either saline, heparin, or streptokinase. Serial measurements were made of total FDP by hemagglutination inhibition assay and of radioactive FDP. After saline, the peak level of total FDP was 323 mug/ml, but radioactive FDP was only 8 mug/ml. After heparin, these values were 44 and 11 mug/ml, respectively, and after streptokinase, 415 and 20 mug/ml. The results suggest that under these experimental conditions the elevated levels of FDP in pulmonary embolism are derived mainly from lysis of fibrin deposited after embolization rather than from lysis of the original embolus. Heparin inhibits both fibrin deposition and elevation of FDP levels after embolism.

Topics: Animals; Dogs; Female; Fibrin; Fibrinogen; Hemagglutination Inhibition Tests; Heparin; Immune Sera; Iodine Radioisotopes; Male; Pulmonary Embolism; Rabbits; Streptokinase

A study of serum levels of fibrinogen-fibrin-related antigen (F.R.-antigen) in outpatients presenting with clinical features suggesting deep vein thrombosis was undertaken. A raised serum level of this antigen (greater than 12 mg/1) is strong evidence in favour of the diagnosis of deep vein thrombosis. It is virtually conclusive evidence if other known causes of a raised level of the antigen are absent. On the other hand, a normal serum level of F.R.-antigen does not exclude even extensive thrombosis, and other objective techniques are required to substantiate the diagnosis.

Topics: Adult; Antigens; Female; Fibrin; Fibrinogen; Humans; Latex Fixation Tests; Leg; Male; Middle Aged; Outpatient Clinics, Hospital; Pulmonary Embolism; Thrombophlebitis

Topics: Animals; Blood Vessels; Embolism, Fat; Fibrin; Lung; Microscopy, Electron; Platelet Aggregation; Pulmonary Embolism; Rats; Triolein

The intravenous injection of mice with toxic doses of vaccinia virus, prepared in the Ehrlich ascites carcinoma, usually produces fatal intravascular coagulation, within 24 hours. Light and electron microscope studies demonstrate occlusion of the microcirculation of lungs and livers by fibrin. Fibrin deposition appears to be prevented in mice injected with heparinized virus preparations. However, in lieu of fibrin deposition, within the microcirculation widespread intravascular platelet aggregation occurs. Platelets within these aggregates are in various stages of degranulation, and some platelets have phagocytosed vaccinia virus. Platelet aggregation was not observed in mice receiving injections of heparinized material prepared from uninfected tumors. In mice surviving longer than 12 hours, hepatocytes and endothelial cells of pulmonary capillaries are the sites of viral replication. Although many hepatocytes are infected in mice surviving longer than 12 hours, it is postulated that hepatocyte necrosis is in part due to the congestive effects resulting from obstruction of liver and pulmonary capillaries. These studies suggest that vaccinia virus may trigger in vivo platelet aggregation, and that obstruction of the lung and liver microcirculation by these aggregates is the initial lesion of vaccinia virus toxicity.

Topics: Animals; Blood Platelets; Capillaries; Erythrocyte Aggregation; Fibrin; Heparin; Kupffer Cells; Liver; Liver Diseases; Lung; Mice; Microcirculation; Phagocytosis; Platelet Aggregation; Pulmonary Embolism; Thrombosis; Vaccinia virus; Virus Replication

Topics: Aged; Arthritis, Rheumatoid; Blood Cell Count; Blood Platelets; Carbon Radioisotopes; Collagen Diseases; Factor XIII; Female; Fibrin; Fibrinolysis; Heart Failure; Humans; Hypertension, Malignant; Infections; Leukemia; Liver Diseases; Neoplasms; Pulmonary Embolism; Sepsis; Streptokinase

Topics: Animals; Blood Coagulation; Disease Models, Animal; Dogs; Electric Injuries; Electrodes; Electrophoresis, Polyacrylamide Gel; Femoral Vein; Fibrin; Ligation; Platelet Aggregation; Pulmonary Embolism; Thrombophlebitis

Topics: Animals; Biological Products; Catheterization; Dogs; Fasting; Fibrin; Fibrinogen; Hemagglutination Inhibition Tests; Hematocrit; Immune Sera; Jugular Veins; Pentobarbital; Pulmonary Embolism; Time Factors

Topics: Amino Alcohols; Animals; Fibrin; Nicotinic Acids; Pulmonary Embolism; Rabbits; Theophylline

Topics: Adult; Aged; Autopsy; Bronchi; Chronic Disease; Epithelium; Female; Fibrin; Humans; Influenza, Human; Lung; Male; Middle Aged; Orthomyxoviridae; Pneumonia, Viral; Pulmonary Alveoli; Pulmonary Embolism

Topics: Animals; Burns; Fibrin; Fractures, Bone; Humans; Hypoxia; Lung; Microcirculation; Pulmonary Edema; Pulmonary Embolism; Wounds and Injuries

Topics: Agglutination Tests; Fibrin; Humans; Pulmonary Embolism; Staphylococcus

Topics: Animals; Antigens; Blood Cell Count; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Cineangiography; Dogs; Factor V; Factor VIII; Female; Fibrin; Fibrinogen; Fibrinolysis; Iodine Radioisotopes; Leukocyte Count; Male; Plasminogen; Pulmonary Embolism; Thrombin

Topics: Apnea; Catheterization; Female; Fibrin; Humans; Infant Nutritional Physiological Phenomena; Infant, Newborn; Infant, Newborn, Diseases; Parenteral Nutrition; Pulmonary Embolism; Thrombosis

Topics: Blood Coagulation Factors; Carbon Dioxide; Disseminated Intravascular Coagulation; Fibrin; Fibrinolysis; Humans; Immunodiffusion; Lung Diseases, Obstructive; Oxygen; Pulmonary Embolism; Respiratory Insufficiency; Time Factors

Topics: Animals; Blood Coagulation Tests; Chemical Precipitation; Chromatography, Gel; Cold Temperature; Fibrin; Fibrinogen; Heparin; Humans; Immunoassay; Immunodiffusion; Iodine Radioisotopes; Macromolecular Substances; Molecular Weight; Polymers; Pulmonary Embolism; Rabbits; Serum Globulins; Solubility; Thrombin; Thrombosis

Topics: Adult; Antibodies; Antibodies, Anti-Idiotypic; Blood Cell Count; Blood Coagulation; Blood Coagulation Disorders; Blood Platelet Disorders; Clot Retraction; Erythrocytes; Factor X; Female; Fibrin; Fibrinogen; Fibrinolysin; Fibrinolysis; Humans; Male; Plasminogen; Platelet Adhesiveness; Pulmonary Embolism; Stimulation, Chemical; Thrombin; Thrombophlebitis; Thrombosis

Topics: Adolescent; Adult; Buffers; Female; Fibrin; Fibrinogen; Heparin; Humans; Male; Middle Aged; Protamines; Pulmonary Embolism; Sulfates; Thromboembolism; Thrombophlebitis; Thrombosis; Tromethamine

Topics: Fibrin; Fibrinogen; Hemagglutination Tests; Humans; Latex Fixation Tests; Pulmonary Embolism

Topics: Adult; Brain; Craniocerebral Trauma; Fibrin; Humans; Lung; Male; Pulmonary Artery; Pulmonary Embolism; Wounds, Gunshot

Topics: Acute Disease; Adult; Aged; Angiography; Drug Resistance; Female; Fibrin; Fibrinogen; Heparin; Humans; Infusions, Parenteral; Iodine Radioisotopes; Male; Middle Aged; Plasminogen; Prothrombin Time; Pulmonary Embolism; Radioisotopes; Radionuclide Imaging; Streptokinase; Time Factors

Topics: Adult; Aged; Aspartate Aminotransferases; Bilirubin; Carbon Dioxide; Clinical Enzyme Tests; Electrocardiography; Female; Fibrin; Humans; L-Lactate Dehydrogenase; Male; Middle Aged; Oxygen; Partial Pressure; Protamines; Pulmonary Embolism; Radiography; Radionuclide Imaging

Topics: Animals; Biopsy; Blood Coagulation Tests; Bone and Bones; Collagen; Disease Models, Animal; Disseminated Intravascular Coagulation; Dogs; Embolism, Fat; Exudates and Transudates; Fibrin; Fractures, Bone; Hindlimb; Hypoxia; Leukocytes; Lung; Microscopy; Microscopy, Electron; Muscles; Musculoskeletal System; Pulmonary Edema; Pulmonary Embolism; Triolein

Topics: Acute Disease; Adolescent; Adult; Aged; Blood Coagulation Tests; Diagnosis, Differential; Fibrin; Fibrinogen; Humans; Iodine Radioisotopes; Methods; Middle Aged; Phlebography; Protamines; Pulmonary Embolism; Radionuclide Imaging; Staphylococcus; Thrombophlebitis

Topics: Acute Disease; Adult; Aged; Angiography; Cardiac Catheterization; False Negative Reactions; False Positive Reactions; Fibrin; Humans; Lung; Methods; Middle Aged; Pulmonary Embolism

Topics: Aged; Angiography; Antigens; Female; Femoral Neck Fractures; Fibrin; Fibrinogen; Fibrinolysis; Heart Failure; Humans; Iodine Radioisotopes; Male; Neoplasm Metastasis; Postoperative Complications; Pulmonary Embolism; Radionuclide Imaging; Sepsis; Thrombophlebitis

Topics: Fibrin; Fibrinogen; Humans; Pulmonary Embolism; Thrombophlebitis

Topics: Antigens; Fibrin; Fibrinogen; Humans; Postoperative Complications; Pulmonary Embolism; Thrombophlebitis

Topics: Adult; Anticoagulants; Blood Cell Count; Blood Platelets; Ethyl Biscoumacetate; Ethylestrenol; Female; Fibrin; Fibrinogen; Fibrinolysis; Fluorescent Antibody Technique; Heparin; Humans; Male; Middle Aged; Myocardial Infarction; Neutrophils; Phagocytosis; Phenformin; Phlebography; Platelet Adhesiveness; Pulmonary Embolism; Pyrazoles; Thrombophlebitis; Time Factors

Topics: Blood Platelets; Blood Preservation; Fibrin; Filtration; Humans; Leukocytes; Methods; Pulmonary Embolism; Time Factors

Topics: Angiography; Animals; Aspergillus; Blood Coagulation Factors; Blood Transfusion, Autologous; Cineangiography; Dogs; Female; Fibrin; Fibrinogen; Injections, Intra-Arterial; Injections, Intravenous; Male; Peptide Hydrolases; Pulmonary Embolism

Topics: Aminocaproates; Animals; Antifibrinolytic Agents; Caseins; Disseminated Intravascular Coagulation; Fibrin; Fibrinolysis; Fibrinolytic Agents; Iodine Radioisotopes; Lung; Monitoring, Physiologic; Pulmonary Embolism; Radiometry; Rats; Thrombin

A rapid slide test for the detection of degradation products of fibrinogen/fibrin (FDP) using a new antibody-coated latex particle is described. The latex particle has been specifically coated with antibody to fragments D and E. The latex agglutination test (Thrombo-Wellcotest) has been compared with the tanned red cell haemagglutination inhibition immunoassay (TRCHII) in 143 patients with a variety of clinical conditions. There is a high degree of agreement between the methods with a coefficient of correlation of 0.83. The method provides a rapid, simple screening test for fibrin degradation products.

Topics: Antibodies; Fibrin; Fibrinogen; Hemagglutination Inhibition Tests; Humans; Hyperthyroidism; Kidney Diseases; Latex; Liver Diseases; Methods; Microspheres; Neoplasms; Pulmonary Embolism

Topics: Anemia, Sickle Cell; Animals; Anticoagulants; Coumarins; Fibrin; Heparin; Humans; Male; Priapism; Pulmonary Embolism; Retinal Diseases; Retinal Vessels; Snakes; Thrombosis; Venoms

Topics: Animals; Antigens; Blood Coagulation; Disseminated Intravascular Coagulation; Erythrocytes; Fibrin; Fibrinogen; Fibrinolysis; Hemagglutination Inhibition Tests; Immune Sera; Immunodiffusion; Immunoelectrophoresis; Injections, Intravenous; Peptides; Pulmonary Embolism; Rats; Thrombin; Thrombosis; Venae Cavae

Topics: Acute Disease; Acute Kidney Injury; Adult; Aged; Agglutination Tests; Arteries; Arteriosclerosis Obliterans; Blood Coagulation Tests; Contraceptives, Oral; Disseminated Intravascular Coagulation; Female; Fibrin; Fibrinolysis; Humans; Liver Cirrhosis; Male; Methods; Middle Aged; Neoplasm Metastasis; Protamines; Pulmonary Embolism; Staphylococcus; Sulfates; Thrombosis; Veins

Topics: Aged; Antigens; Fibrin; Fibrinogen; Humans; Iodine Isotopes; Middle Aged; Postoperative Complications; Pulmonary Embolism; Thrombophlebitis; Time Factors

Topics: Adult; Embolism, Amniotic Fluid; Female; Fibrin; Fibrinogen; Heparin; Humans; Maternal Mortality; Pregnancy; Pulmonary Embolism

Topics: Animals; Cattle; Fibrin; Fibrinolysis; Heparin; Plasminogen; Pulmonary Embolism; Thrombin; Thromboembolism

Topics: Accidents, Traffic; Aged; Autopsy; Blood Coagulation Disorders; Embolism, Fat; Female; Femoral Fractures; Fibrin; Fracture Fixation, Intramedullary; Fractures, Bone; Humans; Intracranial Embolism and Thrombosis; Lipids; Lung; Male; Middle Aged; Pelvic Bones; Pulmonary Artery; Pulmonary Embolism; Pulmonary Veins; Tibial Fractures; Time Factors; Wounds and Injuries

A total of 76 "high-risk" surgical patients were studied for evidence of venous thromboembolic disease. Episodes of deep vein thrombosis and of pulmonary embolism were related to changes in blood levels of fibrin degradation products (F.D.P.). When diagnosed either by ordinary clinical means or by venography and isotope scanning significantly raised F.D.P. levels were found in all cases. Serum F.D.P. estimations are unlikely to help in detecting deep vein thrombosis, but may prove valuable in diagnosing pulmonary embolism.

Topics: Adult; Aged; Female; Fibrin; Fibrinogen; Humans; Iodine Radioisotopes; Male; Middle Aged; Phlebography; Postoperative Complications; Pulmonary Embolism; Radionuclide Imaging; Thrombophlebitis

Topics: Fibrin; Fibrinogen; Humans; Immunoassay; Pulmonary Embolism; Thrombophlebitis

Topics: Adipose Tissue; Animals; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelets; Embolism, Fat; Factor V; Female; Fibrin; Fibrinogen; Fractures, Bone; Heparin; Hindlimb; Injections, Intravenous; Iodine Isotopes; Lipids; Lung; Pulmonary Embolism; Rabbits; Rats; Thrombosis

Topics: Age Factors; Aged; Anticoagulants; Blood Circulation; Blood Coagulation; Blood Platelets; Female; Fibrin; Fibrinogen; Germany, West; Humans; Male; Microscopy, Electron; Middle Aged; Pulmonary Embolism; Sex Factors

Topics: Adipose Tissue; Aminocaproates; Animals; Blood Coagulation; Blood Coagulation Factors; Blood Coagulation Tests; Embolism, Fat; Female; Femoral Fractures; Fibrin; Fibrinolysis; Hemoglobinometry; Hemolysis; Phagocytosis; Plasminogen; Premedication; Pulmonary Embolism; Rats; Serum Albumin, Radio-Iodinated; Trypan Blue

Topics: Animals; Benzopyrans; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelet Disorders; Budd-Chiari Syndrome; Coronary Disease; Female; Fibrin; Fibrinogen; Fibrinolysis; Heparin; Mice; Microscopy; Microscopy, Electron; Placenta; Placenta Diseases; Pregnancy; Pregnancy Complications; Pulmonary Embolism; Renal Veins; Thrombosis; Veins

Topics: Animals; Budd-Chiari Syndrome; Dogs; Femoral Artery; Fibrin; Humans; Portal Vein; Pulmonary Embolism; Rabbits; Thrombin; Thromboembolism; Thrombosis; Veins

Topics: Adult; Female; Fibrin; Fibrinogen; Humans; Immunoassay; Myocardial Infarction; Pulmonary Embolism

Topics: Diagnosis, Differential; Embolism, Fat; Fibrin; Heparin; Humans; Hypertension, Pulmonary; Injections, Intravenous; Pulmonary Embolism; Time Factors

Topics: Adolescent; Adult; Aged; Blood Platelet Disorders; Child; Female; Fibrin; Hospitals, General; Humans; Male; Methods; Middle Aged; Postoperative Complications; Pulmonary Embolism; Thrombosis

Topics: Abruptio Placentae; Animals; Blood Coagulation Disorders; Dogs; Embolism, Amniotic Fluid; Female; Fibrin; Humans; Meconium; Mice; Motion Pictures; Photomicrography; Pregnancy; Pulmonary Embolism; Rabbits; Staining and Labeling

Topics: Autopsy; Bronchitis; Burns; Embolism, Fat; Fibrin; Humans; Lung; Pneumonia; Pulmonary Alveoli; Pulmonary Artery; Pulmonary Embolism; Pulmonary Veins; Thoracic Injuries

Topics: Animals; Blood Coagulation Disorders; Capillaries; Dogs; Fibrin; Gastric Mucosa; Heparin; Humans; Kidney Glomerulus; Lung; Male; Middle Aged; Popliteal Vein; Pulmonary Embolism; Rabbits; Rats; Thrombophlebitis; Thrombosis

Topics: Animals; Blood Coagulation; Blood Platelets; Chlorides; Cytoplasmic Granules; Ear; Female; Fibrin; In Vitro Techniques; Iron; Male; Microscopy; Microscopy, Electron; Pulmonary Embolism; Rabbits; Thrombin; Thrombosis; Veins

Topics: Animals; Arteriosclerosis; Cattle; Fibrin; Histocytochemistry; Jugular Veins; Male; Pulmonary Artery; Pulmonary Embolism; Rabbits; Thrombin

Topics: Blood Platelets; Fibrin; Hemostasis; Humans; Pathology; Pulmonary Embolism; Thrombosis

Topics: Aminocaproates; Aminocaproic Acid; Animals; Arteriosclerosis; Fibrin; Fibrinolysis; Glycosuria; Hematuria; Kidney Diseases; Kidney Glomerulus; Pharmacology; Pulmonary Embolism; Rabbits; Rats; Research; Thrombin

Topics: Animals; Arteriosclerosis; Epinephrine; Fibrin; Fibrinolysis; Humans; Pathology; Pharmacology; Pulmonary Artery; Pulmonary Embolism; Rabbits; Research; Serotonin; Vascular Diseases; Vasoconstriction

Topics: Brain Diseases; Brain Edema; Fibrin; Kidney Cortex Necrosis; Kidney Diseases; Kidney Glomerulus; Myocardial Infarction; Necrosis; Pathology; Pulmonary Embolism; Shwartzman Phenomenon; Thrombosis

Topics: Blood Platelets; Capillaries; Cardiovascular System; Dogs; Fibrin; Heart, Artificial; Hemorrhage; Lung Injury; Pathology; Pulmonary Atelectasis; Pulmonary Embolism; Research

Topics: Embolism; Fibrin; Forensic Medicine; Fractures, Bone; Humans; Pulmonary Embolism; Wounds and Injuries

Topics: Embolism; Embolism, Fat; Female; Fibrin; Hemorrhage; Hemorrhagic Disorders; Humans; Postpartum Hemorrhage; Postpartum Period; Pulmonary Embolism

Topics: Amnion; Amniotic Fluid; Capillaries; Embolism; Fibrin; Humans; Pulmonary Embolism; Thrombosis

Topics: Embolism; Fibrin; Humans; Lung; Pulmonary Embolism; Thrombosis