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PubMed1987

Occurrence of blood coagulation factors in situ in small cell carcinoma of the lung.

Through immunohistochemical techniques, blood coagulation factors were identified in situ in fresh frozen sections of small cell carcinoma of the lung. Prothrombin/thrombin, factor VII, factor X, and antithrombin III were present in intercellular spaces and associated with tumor cells. Factor IX, factor XI, prekallikrein, and high molecular weight kininogen were identified as being associated with tumor cells but did not exist in intercellular spaces. Variable connective tissue staining but no tumor-related staining was observed for factor V, factor VIII-related antigen, factor XII, the B subunit of factor XIII, alpha 1-antitrypsin, alpha 2-macroglobulin, or alpha 2-antiplasmin. Neither consecutive tissue nor the tumor manifested platelet Ib and IIbIIIa surface glycoproteins. These divergent staining patterns suggested that the detected clotting factors had not merely diffused from permeabilized blood vessels, but were selectively localized in situ. While conditions may exist within tumor tissue that both retard and promote thrombin generation, we propose that interactions between the observed coagulation factors ultimately lead to local thrombin formation, which is responsible for the conspicuous fibrin deposits already described in small cell carcinoma of the lung. Thrombin formed locally might contribute to progression of this tumor. Inhibition of local thrombin formation by warfarin therapy could explain the beneficial effects of warfarin therapy in treating small cell carcinoma of the lung.

Antigens↗
PubMed2004

Prothrombotic markers in familial combined hyperlipidemia: evidence of endothelial cell activation and relation to metabolic syndrome.

BACKGROUND: Familial combined hyperlipidemia (FCHL) is characterized by a varied expression of hypertriglyceridemia and hypercholesterolemia within a family, and a high risk of premature coronary artery disease. The present study evaluated a number of potential prothrombotic markers in familial combined hyperlipidemia, and studied their relationship to the hypercholesterolemic (Fredrickson type IIa) and hypertriglyceridemic (IIb and IV) phenotypes. METHODS AND RESULTS: Selected prothrombotic markers were studied in 68 subjects: 34 hyperlipidemic subjects with familial combined hyperlipidemia and 34 controls. FCHL patients exhibited significantly higher Thrombin-Antithrombin complex (TAT), activated coagulation factor XII (F XIIa), von Willebrand Factor (vWF), Plasminogen Activator Inhibitor-1 (PAI-1) and tissue derived Plasminogen Activator (t-PA) values in comparison to controls. Within the subgroup of familial combined hyperlipidemia subjects, elevated PAI-1 activity and soluble Thrombomodulin levels were particularly associated with features of the metabolic syndrome, including hyperinsulinemia, hypertriglyceridemia and predominance of small dense low density lipoprotein (LDL). CONCLUSIONS: A general pattern of activated blood coagulation and endothelial activation is present in all hyperlipidemic subjects studied, independent of metabolic phenotype. In those familial combined hyperlipidemia subjects with features of the metabolic syndrome, impaired fibrinolysis can provide an additional cardiovascular risk factor.

Adult↗
PubMed2004

Beta2-glycoprotein I, anti-beta2-glycoprotein I, and fibrinolysis.

Beta2-glycoprotein-I (beta2GPI) is a phospholipid-binding plasma protein that consists of five homologous domains. Domain V is distinguished from others by bearing a positively charged lysine cluster and hydrophobic extra C-terminal loop. Beta2GPI has been known as a natural anticoagulant regulator. Beta2GPI exerts anticoagulant activity by inhibition of phospholipid-dependent coagulation reactions such as prothrombinase, tenase, and factor XII activation. It also binds factor XI and inhibits its activation. On the other hand, beta2GPI inhibits anticoagulant activity of activated protein C. According to the data from knockout mice, beta2GPI may contribute to thrombin generation in vivo. Phospholipid-bound beta2GPI is one of the major target antigens for antiphospholipid antibodies present in patients with antiphospholipid syndrome (APS). Binding of pathogenic anti-beta2GPI antibodies increases the affinity of beta2GPI to the cell surface and disrupts the coagulation/fibrinolysis balance on the cell surface. These pathogenic antibodies activate endothelial cells via signal transduction events in the presence of beta2GPI. Impaired fibrinolysis has been reported in patients with APS. Using a newly developed chromogenic assay, we demonstrated lower activity of intrinsic fibrinolysis in euglobulin fractions from APS patients. Addition of monoclonal anti-beta2GPI antibodies with beta2GPI also decreased fibrinolytic activity in this assay system. beta2GPI is proteolytically cleaved by plasmin in domain V (nicked beta2GPI) and becomes unable to bind to phospholipids, reducing antigenicity against antiphospholipid antibodies. This cleavage occurs in patients with increased fibrinolysis turnover. Nicked beta2GPI binds to plasminogen and suppresses plasmin generation in the presence of fibrin, plasminogen, and tissue plasminogen activator (tPA). Thus, nicked beta2GPI plays a role in the extrinsic fibrinolysis via a negative feedback pathway loop.

Animals↗
PubMedDate not supplied

Diabetes mellitus: a hypercoagulable state.

Eighty percent of patients with diabetes mellitus die a thrombotic death. Seventy-five percent of these deaths is due to cardiovascular complications, and the remainder is due to cerebrovascular events and peripheral vascular complications. Vascular endothelium, the primary defense against thrombosis, is abnormal in diabetes. Endothelial abnormalities undoubtedly play a role in the enhanced activation of platelets and clotting factors seen in diabetes. Coagulation activation markers, such as prothrombin activation fragment 1+2 and thrombin-anti-thrombin complexes, are elevated in diabetes. The plasma levels of many clotting factors including fibrinogen, factor VII, factor VIII, factor XI, factor XII, kallikrein, and von Willebrand factor are elevated in diabetes. Conversely, the level of the anticoagulant protein C (PC) is decreased. The fibrinolytic system, the primary means of removing clots, is relatively inhibited in diabetes due to abnormal clot structures that are more resistant to degradation and an increase in plasminogen activator inhibitor type 1 (PAI-1). Increased circulating platelet aggregates, increased platelet aggregation in response to platelet agonists, increased platelet contractile force (PCF), and the presence of higher plasma levels of platelet release products, such as beta-thromboglobulin, platelet factor 4, and thromboxane B(2), demonstrate platelet hyperactivity in diabetes. This constellation of findings supports the clinical observation that diabetes is a hypercoagulable state. This article briefly reviews the published evidence for this conclusion and the putative roles played by hyperglycemia and hyperinsulinemia in its development.

Anticoagulants↗
PubMed2002

Recurrent reproductive wastage and immunologic factors.

PROBLEM: The causes of recurrent reproductive wastage are varied and complex. The present study was designed to focus on the role of immunologic factors in cases where other causes were not evident. METHOD OF STUDY: Over 20 years, more than 1500 couples were evaluated in our clinic because of recurrent spontaneous abortion. Women were tested for anti-phospholipid antibodies and plasma contact proteins of the intrinsic pathway of blood coagulation after endocrine, organic, infectious and genetic etiologies of miscarriages were excluded. RESULTS: Anti-phosphatidylethanolamine antibodies, anti-annexin antibodies, and factor XII deficiency were more common factors in recurrent spontaneous abortion patients than were anti-cardiolipin antibodies in terms of induction of recurrent pregnancy losses. Paternal leukocyte immunotherapy of patients without such abnormalities was associated with a significantly improved success rate. CONCLUSIONS: Recurrent reproductive wastage can be minimized by individualized therapy based on comprehensive evaluation of immunologic factors, including several anti-phospholipid antibodies.

Abortion, Habitual↗
PubMed1982

Blood coagulation tests of gorillas.

In coagulation tests on five lowland gorillas, values within or close to the normal human range were found with the following tests: partial thromboplastin time, prothrombin time, thrombin time, factor XIII screen, factor II assay, factor V assay, fibrinogen and antithrombin III. Factor XII levels were very high. Factor VIII coagulant activity was moderately elevated but factor VIII antigen was very high in all and ristocetin cofactor activity was low in four of five.

Animals↗
PubMed1982

Purified human plasma kallikrein aggregates human blood neutrophils.

Exposure of human blood polymorphonuclear leukocytes (PMN) to purified active plasma kallikrein resulted in PMN aggregation when kallikrein was present at concentrations ranging from 0.4 to 0.6 U/ml (0.18-0.27 microM). Kallikrein-induced PMN aggregation was not mediated through C5-derived peptides, because identical responses were observed whether or not kallikrein had been preincubated with an antibody to C5. Moreover, kallikrein was specific for aggregating PMN, because no aggregation was observed with Factor XII active fragments (23 nM), Factor XIa (0.6 U/ml or 15nM), thrombin (1.6 microM), plasmin (2 microM), porcine pancreatic elastase (2 microM), bovine pancreatic chymotrypsin (2 microM), or bradykinin (1 microM). Bovine pancreatic trypsin (2 microM) aggregated PMN, but to a lesser extent than kallikrein (0.18 microM). Kallikrein was a potent aggregant agent for PMN because similar responses were observed with kallikrein (0.5 U/ml or 0.23 microM) and an optimal dose (0.2 microM) of N-formyl-methionyl-leucyl-phenylalanine. In addition, PMN incubation with kallikrein resulted in stimulation of their oxidative metabolism as assessed by an increased oxygen uptake. Neutropenia and leukostasis observed in diseases associated with activation of the contact phase system may be the result of PMN aggregation by plasma kallikrein.

Cell Aggregation↗
PubMed1976

So-called "vascular headache of the migraine type": one or more nosological entities?

The dispute about whether migraine and cluster headache are one disorder--the "unified theory"--or two facets of a spectrum of "vascular headache" has not yet been settled. The author discusses various clinical features that unite or divide migraine and cluster headache in this respect: so-called "mixed forms" of vascular headache, corneal indentation pulse amplitudes, partial Horner's syndrome and possible aberrations in histamine metabolism. Evidence is presented showing that there may exist subunits of cluster headache, such as chronic paroxysmal hemicrania (C.P.H.) and a hitherto unreported type that co-exists with recurring bouts of retrobulbar neuritis and a partial factor XII deficiency.

Adult↗
PubMed1979

Interactions among Hageman factor, plasma prekallikrein, high molecular weight kininogen, and plasma thromboplastin antecedent.

To investigate the earliest steps of the intrinsic clotting pathway, Hageman factor (Factor XII) was exposed to Sephadex gels to which ellagic acid had been adsorbed; Hageman factor was then separated from the gels and studied in the fluid phase. Sephadex-ellagic acid-exposed Hageman factor, whether purified or in plasma, activated plasma thromboplastin antecedent, but only when high molecular weight kininogen was presnet. In the absence of plasma prekallikrein, maximal activation of plasma thromboplastin antecedent was slightly delayed in plasma, a delay not observed with similarly treated purified Hageman factor. Thus, high molecular weight kininogen was needed for expression of Hageman factor's clot-promoting properties and plasma prekallikrein played a minor role in the interaction of ellagic acid-treated Hageman factor and plasma thromboplastin antecedent.

Blood Coagulation↗
PubMed1976

Comparison of the coagulant activities of platelets and phospholipids.

The coagulant activities of various phospholipid preparations were compared with those of platelets. Folch phospholipid with maximal platelet factor 3 (PF3) activity produced long recalcified clotting times of relatively undiluted plasma in plastic tubes whereas untreated or ADP-treated platelets with minimal PF3 activity produced short clotting times in the same test system which is sensitive to activators of the contact system of intrinsic coagulation. Bell and Alton phospholipids with maximal PF3 activity produced recalcified clotting times similar to those in the presence of platelets. Bell and Alton phospholipids had tissue factor activity, but Folch phospholipid and platelets did not. Bell and Alton phospholipids and gum acacia (used as a vehicle in one of the preparations) activated factor XII as did platelets, but Folch phospholipid did not. The multiple coagulant activities of Bell and Alton phospholipids (i.e. PF3, tissue factor and contact activating) may account for the absence of coagulant superiority of platelets in the undiluted system in plastic tubes. The coagulant activities of platelets are also complex but different from Bell and Alton phospholipids whereas Folch phospholipid would appear to possess only PF3 activity.

Blood Coagulation↗
PubMed1990

FXII.

The plasma protein FXII (Hageman factor) has been shown to be linked with the plasma defence systems of coagulation, fibrinolysis, kallikrein-kinin and complement. It can be activated by surface contact activation and in solution. Surface contact activation is a complex phenomenon involving negatively charged surfaces, FXII, high molecular weight kininogen and plasma kallikrein. Fluid-phase activation can be effected by a variety of serine proteases. In both types of activation the FXII zymogen is converted to active enzymes. FXII levels in plasma are low or undetectable in both inherited deficiencies and in a variety of clinical conditions. FXII levels can also be elevated in some clinical conditions. Although discovered as a clotting protein FXII appears to play an important role in the kallikrein-kinin and fibrinolytic systems and also has effects on cells. Recent studies suggest that therapeutic blockade of activation of FXII can be of benefit in certain clinical conditions.

Animals↗
PubMed1995

Amidolytic assay of factor XI in human plasma--significance of kallikrein for the activity measured.

Factor XI (FXI) deficiency is associated with an abnormal bleeding state. The extent of bleeding does not correlate well with the plasma concentration of FXI, and it has been suggested that also unknown factors interfere with the bleeding tendency. In a recent paper (Thromb. Res. 74, 477-485, 1994) we found that FXIa activated in human plasma was present in association with part of factor XIIa (FXIIa) and part of kallikrein, influencing their functional activities. Should the activity level of FXIa also be altered by the other contact factors this might provide one approach to the problem of the failure of assays of FXIa to correlate with bleeding tendency. In the present study we have developed an assay procedure for FXIa based on its amidolytic (S-2366) activity, and allowing at the same time a quantification of the amount of FXIa associated to kallikrein. The total amidase activity obtained was separated into two main fractions by use of soybean trypsin inhibitor (STI), corn inhibitor (CI) and lima bean trypsin inhibitor (LTI). One fraction contained free FXIa which could be specifically blocked by LTI. An inhibitor resistant fraction was found to contain FXIa inactive in association with kallikrein. The content of FXIa could be assessed in experiments with mixtures of normal plasma and plasma deficient in prekallikrein, and was taken into account in the calculations. This fraction increased during storage of plasma at -70 degrees C. To obtain stable and comparable assay conditions the method was based on plasma stored for at least four weeks. The specificity of the method was verified by parallel radial immunodiffusion tests. The results imply that the activity level of FXIa is dependent on kallikrein present. If the experimental results has relevance to the situation under physiological conditions, they indicate one possible cause of the failure of assays of FXI to correlate with bleeding tendency.

Adult↗
PubMed1989

Procainamide-induced circulating anticoagulants in a congenitally-deficient factor XI patient.

A 70 year old male patient admitted for coronary bypass surgery presented with a procainamide-induced lupus syndrome. This syndrome included a LLAC with a positive IgM ACA titer as well as a factor XII inhibitor. These drug-induced inhibitors were superimposed upon the patient's congenital deficiency of factor XI. The methods used to identify these abnormalities are described together with the replacement therapy employed to cover the surgical procedure. The long-term withdrawal of procainamide was associated with correction of all coagulation abnormalities except the factor XI deficiency.

Aged↗
PubMed1990

Morphologic characteristics of adsorbed human plasma proteins on vascular grafts and biomaterials.

Protein adsorption on the surfaces of clinically significant prosthetic vascular graft materials from human whole blood was independent of plasma concentration as determined morphologically by use of immunogold labels. Some proteins, such as fibrinogen, adsorbed in a multilayer pattern on expanded polytetrafluoroethylene and had a preference for particular surface features of the polymer. Other proteins, such as Hageman factor (factor XII), showed diffuse adsorption patterns. Physiologically significant proteins that have not been well studied, such as immunoglobulin G and factor VIII, adsorbed readily to the surface of expanded polytetrafluoroethylene. This finding may be significant since adsorbed proteins may activate coagulation mechanisms and immunologic responses, including platelet and monocyte adhesion and activation. Any human blood protein for which an antibody has been developed can be studied by use of this technique.

Adsorption↗
PubMed1970

Effect of cellulose sulphate on serum complement.

Cellulose sulphate 50-600 mug/ml reduces complement titres in human serum. This effect is, in contrast to the clot-promoting and plasma kinin forming action of cellulose sulphate, not mediated by clotting factor XII.

Blood Coagulation↗