Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Factor XII Deficiency”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1980

Interaction of high molecular weight kininogen, factor XII, and fibrinogen in plasma at interfaces.

Using ellipsometry, anodized tantalum interference color, and Coomassie blue staining in conjunction with immunologic identification of proteins adsorbed at interfaces, we have previously found that fibrinogen is the main constituent deposited by plasma onto many man-made surfaces. However, the fibrinogen deposited from normal plasma onto glass and similar wettable materials is rapidly modified during contact activation until it can no longer be identified antigenically. In earlier publications, we have called this modification of the fibrinogen layer "conversion," to indicate a process of unknown nature. Conversion of adsorbed fibrinogen by the plasma was not accompanied by marked change in film thickness, so that we presumed that this fibrinogen was not covered but replaced by other protein. Conversion is now showen to be markedly delayed in plasma lacking high molecular weight kininogen, slightly delayed in plasma lacking factor XII, and normal in plasma that lack factor XI or prekallikrein. We conclude that intact plasma will quickly replace the fibrinogen it has deposited on glass-like surfaces by high molecular weight kininogen and, to a smaller extent, by factor XII. Platelets adhere preferentially to fibrinogen-coated surfaces; human platelets adhere to hydrophobic nonactivating surfaces, since on these, adsorbed firbinogen is not exchanged by the plasma. The adsorbed fibrinogen will be replaced on glass-like surfaces during surface activation of clotting, and platelets failing to find fibrinogen will not adhere.

Adsorption↗
PubMed1998

[Hageman trait].

Explore the source record for details and available documents.

Factor XII↗
PubMed1992

Coagulation-factor deficiencies and abnormal bleeding in Noonan's syndrome.

Noonan's syndrome is characterised by a dysmorphic facies, congenital heart disease, and short stature, and is inherited as an autosomal dominant trait. Because abnormal bleeding has also been reported, we investigated a group of patients for coagulation-factor deficits. Of the 72 individuals studied (37 male, 35 female, mean age 11.4 years), 47 (65%) had a history of abnormal bruising or bleeding. 29 patients (40%) had a prolonged activated partial thromboplastin time. Specific abnormalities in the intrinsic pathway of coagulation (partial factor XI:C, XII:C, and VIII:C deficiencies) were found in 36 patients (50%). Multiple abnormalities among these 36 patients included combined factor XI:C and XII:C deficiencies (4 patients) and factor XI:C and VIII:C deficiencies (4), and 1 patient had combined factor VIII:C, XI:C, and XII:C deficiency. There was poor correlation between a history of abnormal bleeding and coagulation-factor deficit. In five families, similar coagulation-factor deficiencies were present in first-degree relatives with the syndrome. The pattern of inherited bleeding abnormalities seen in Noonan's syndrome suggests autosomal regulation of the intrinsic coagulation pathway.

Adolescent↗
PubMed1981

[Lupus anticoagulant screening: comparison of 5 tests (author's transl)].

Five tests were carried out on 15 lupus anticoagulant plasmas: activated partial thromboplastin time with a commercial reagent (APTT); kaolin partial thromboplastin time with a human brain extract (KPTT-H); tissue thromboplastin inhibition test (TTI); Russell's viper venom time without phospholipid (RVVT); assay of phospholipid-related procoagulant activity (PPA). One of our criteria for diagnosis of lupus anticoagulant was a prolonged APTT; hence this test was abnormal in all 15 plasmas. An abnormal TTI was observed for the 15 lupus anticoagulants while PTT-H was abnormal in only 13 cases, RVVT in 11 cases and PPA assay in 12 cases. In another study evaluating the specificity of TTI and PPA assay, the TTI appeared to be influenced by factor II, V, VII, and X deficiencies, but not by factor VIII: C, IX, XI, and XII deficiencies, or by anti-factor VIII: C anticoagulants. Furthermore, the TTI displayed a weak sensitivity to heparin. On the other hand, the PPA assay was influenced by anti-factor VIII: C anticoagulants of high potency and was found to be more sensitive to heparin than the TTI. Our overall results emphasize the value of TTI as a screening test for the lupus anticoagulant.

Blood Coagulation↗
PubMed1977

Thromboembolism in Hageman trait.

The case of a patient with severe deficiency of Hageman factor (factor XII) in whom a thrombus embolized to arteries in a lower extremity is described. In addition to its action in intiating blood clotting through the intrinsic pathway, Hageman factor can influence kinin generation, fibrinolysis, and activation of complement. While individuals with Hageman factor deficiency have no hemorrhagic disorder, this case emphasizes the role factor XII may normally assume in clot dissolution.

Blood Coagulation Disorders↗
PubMed1987

Biological and clinical heterogeneity of lupus and lupus-like anticoagulant in fifty-seven patients.

A lupus or lupus-like inhibitor was detected in 57 patients: 24 systemic lupus erythematosus, 9 autoimmune diseases, 10 lymphoproliferative disease, 11 miscellaneous diseases and 3 asymptomatic patients. No hemorrhagic diathesis was observed in spite of major surgery. Thromboembolism occurred in 19 patients. Among them, 5 patients had recurrent abortions. An extensive study of coagulation profile compared different assays to investigate lupus-like inhibitor: the most sensitive assay was the partial thromboplastin time performed without activator. When performed with kaolin, it was the only assay detecting the lupus cofactor. Prothrombin time was prolonged in only 53% of the patients. Factors VIII, IX, XI and XII were in the normal range in 40% of the patients. When decreased, apparent deficiencies were usually not detectable on further dilutions of the test samples. In 7 patients factor XII antigen and activity were both decreased, suggesting an apparent factor XII deficiency. No relationship was observed between thromboembolic events, underlying disease or biological pattern.

Adolescent↗
PubMed1984

Cleavage of human high molecular weight kininogen markedly enhances its coagulant activity. Evidence that this molecule exists as a procofactor.

High molecular weight kininogen (HMW)-kininogen, the cofactor of contact-activated blood coagulation, accelerates the activation of Factor XII, prekallikrein, and Factor XI on a negatively charged surface. Although prekallikrein and Factor XI circulate as a complex with HMW-kininogen, no physical association has been demonstrated between Factor XII and HMW-kininogen, nor has the order of adsorption to surfaces of these proteins been fully clarified. In this report we explore the requirements for adsorption of HMW-kininogen to a clot-promoting surface (kaolin), in purified systems, as well as in normal plasma and plasma genetically deficient in each of the proteins of the contact system. The fraction of each coagulant protein associated with the kaolin pellet was determined by measuring the difference in coagulant activity between the initial sample and supernatants after incubation with kaolin, or by directly quantifying the amount of 125I-HMW-kininogen that was associated with the kaolin pellet. In normal plasma, the adsorption of HMW-kininogen to kaolin increased as the quantity of kaolin was increased in the incubation mixture. However, the HMW-kininogen in Factor XII-deficient plasma did not absorb appreciably to kaolin. Furthermore, the quantity of HMW-kininogen from prekallikrein-deficient plasma that adsorbed to kaolin was decreased as compared with normal plasma. These observations suggested that HMW-kininogen in plasma must be altered by a reaction involving both Factor XII and prekallikrein in order for HMW-kininogen to adsorb to kaolin, and to express its coagulant activity. Subsequently, the consequence of the inability of HMW-kininogen to associate with a negatively charged surface results in decreased surface activation. This assessment was derived from the further observation of the lack of prekallikrein adsorption and the diminished Factor XI adsorption in both Factor XII-deficient and HMW-kininogen-deficient plasmas, since these two zymogens (prekallikrein and Factor XI) are transported to a negatively charged surface in complex with HMW-kininogen. The percentage of HMW-kininogen coagulant activity that adsorbed to kaolin closely correlated (r = 0.98, slope = 0.97) with the amount of 125I-HMW-kininogen adsorbed, suggesting that adsorption of HMW-kininogen results in the expression of its coagulant activity. Since kallikrein, which is known to cleave HMW-kininogen, is generated when kaolin is added to plasma, we tested the hypothesis that proteolysis by kallikrein was responsible for the enhanced adsorption of HMW-kininogen to kaolin. When purified HMW-kininogen was incubated with purified kallikrein, its ability to absorb to kaolin increased with time of digestion until a maximum was reached. Moreover, (125)I-HMW-kininogen, after cleavage by kallikrein, had markedly increased affinity for kaolin than the uncleaved starting material. Furthermore, fibrinogen, at plasma concentration (3 mg/ml), markedly curtailed the adsorption of a mixture of cleaved and uncleaved HMW-kininogen to kaolin, but was unable to prevent fully cleaved HMW-kininogen from adsorbing to the kaolin. Addition of purified kallikrein to Factor XII-deficient plasma, which bypasses Factor XII-dependent contact-activation amplified the ability of its HMW-kininogen to adsorb to kaolin. These observations indicate that HMW-kininogen is a procofactor that is activated by kallikrein, a product of a reaction which it accelerates. This cleavage, which enhances its association with a clot-promoting surface in a plasma environment, is an event that is necessary for expression of its cofactor activity. These interactions would allow coordination of HMW-kininogen adsorption with the adsorption of Factor XII, which adsorbs independently of cleavage, to the same negatively charged surface.

Adsorption↗
PubMed1983

Plasma prekallikrein: quantitative determination by direct activation with Hageman factor fragment (beta-XIIa).

This report describes a plasma prekallikrein assay which, unlike methods that employ contact activation, is not affected by the factor XII or HMW kininogen content of the plasma analyzed. In this assay beta-XIIa, a potent fluid-phase activator of prekallikrein, is added to diluted plasma in the presence of 20% acetone (to inactivate kallikrein inhibitors) at 30 degrees C and the kallikrein generated is measured with the chromogenic substrate S-2302. Prekallikrein is fully activated under these conditions and the activity remains stable for at least 30 hr. The mean prekallikrein concentration in plasma samples from 24 healthy individuals was 1.50 +/- 0.35 (S.D.) S-2302 U/ml, corresponding to 20.3 +/- 4.7 micrograms/ml prekallikrein (the specific activity of highly purified human prekallikrein was determined to be 74 S-2302 U/mg). In contrast, the mean concentration in five plasma samples from patients deficient in HMW kininogen was 0.38 +/- 0.02 S-2302 U/ml. No activity was generated in prekallikrein-deficient plasma, and essentially normal levels (1.35 +/- 0.18 S-2302 U/ml) were measured in plasmas from three patients with factor XII deficiency. Plasma prekallikrein was also quantitated by radial immunodiffusion, which gave results similar to those obtained by functional assay with beta-XIIa. The determination of plasma prekallikrein by direct activation with beta-XIIa in the presence of acetone offers several advantages over the use of contact activators such as dextran sulfate. These advantages include complete inactivation of kallikrein inhibitors and total activation of prekallikrein (even in plasmas deficient in other contact factors) without simultaneous generation of plasmin.

Activation Analysis↗
PubMed1978

Human platelet chemotaxis: requirement for plasma factor(s) and the role of collagen.

Platelets are actively mobile in plasma in vitro and, in addition, they migrate specifically and directionally toward added intact collagen (chemotaxis). Native human, bovine, and equine collagen, suspended in plasma, induce a chemotactic response in human platelets. However, heat-denatured and dinitrofluorobenzene-treated collagen fail to attract platelets. Platelets migrate directionally and specifically to intact native collagen incubated in plasma over a large distance (6 mm) in a very short time (total 15 min), as observed in a newly designed micromaze apparatus. Platelets obtained from donors deficient in plasma factors XII, IX, and VIII showed normal migration and chemotaxis in normal plasma and in their respective factor-deficient plasmas. Although nondirectional movement (mobility) was normal, platelets from a donor deficient in factor XI did not exhibit chemotaxis toward collagen in either factor XI-deficient plasma or in normal plasma. The results indicate that 1) collagen is a physiological substrate for the chemotactic phenomenon, 2) intact chemical and/or structural integrity of collagen is required for the induction of platelet chemotaxis, 3) at least one plasma constituent, factor XI, plays an essential role in the chemotactic phenomenon, and 4) contact between collagen and a plasma factor is essential for normal chemotaxis.

Blood Platelets↗
PubMed1994

Dextran sulphate inhibits phospholipid and sulphatide mediated autoactivation of factor XII.

In normal plasma, high molecular mass dextran sulphate (DS500) induces formation of amidolytic activity towards the chromogenic substrate H-D-Pro-Phe-Arg-p-nitroanilide (S-2302) specific to factor XII and kallikrein. No amidolytic activity was formed when plasma deficient in prekallikrein was exposed to DS500. In contrast, factor XII amidolytic activity was formed upon exposure to sulphatide or acidic phospholipids. To assess whether DS500 interferes with the sulphatide and the acidic phospholipid in activating factor XII, plasma deficient in prekallikrein was incubated with phosphatidylinositol phosphate (PtdInsP) and sulphatide at the conditions necessary for activation with these surfaces and various concentrations of DS500. DS500 inhibited both the PtdInsP and the sulphatide-mediated autoactivation in an antithrombin III independent manner. Heparin also inhibited the PtdInsP mediated autoactivation but not that mediated by sulphatide. The heparin inhibition was due to enhancement of the antithrombin III activity, which could be partly blocked by preincubation of plasma with rabbit anti-human antithrombin III IgG.

Amino Acid Sequence↗
PubMed1983

Dextran sulfate-dependent fibrinolysis in whole human plasma.

This study shows that Flu-beta-Ala can reduce the ability of human plasma to inhibit plasmin. This observation was utilized to develop a method for generating detectable fibrinolytic activity in whole human plasma as assessed on a radiolabeled fibrin plate. Plasma was pretreated with Flu-beta-Ala to remove inhibitors of fibrinolysis: then dextran sulfate was added and the mixture was further incubated at 4 degrees C. When normal plasma was treated in this manner, the rate of generation of fibrinolytic activity after 0.75 hr incubation with radiolabeled fibrin was equivalent to that of 35 ng/ml plasmin. The plasminogen dependence of this activity was tested by pretreating plasma with antibodies against plasminogen. The generation of fibrinolytic activity was totally blocked by this treatment, indicating that the observed fibrinolytic activity was plasminogen-dependent. When plasmas deficient in prekallikrein, factor XII, or high-molecular-weight kininogen were treated with Flu-beta-Ala and dextran sulfate, the initial rate of fibrinolytic activity was less than normal. But after 3 hr incubation with radiolabeled fibrin, the rate of fibrinolytic activity in these deficient plasmas approached that of normal plasma. Thus this dextran sulfate-dependent fibrinolytic activity is dependent on factor XII, prekallikrein, and high-molecular-weight kininogen, but the requirement is not absolute.

Dextran Sulfate↗
PubMed2001

Hemostasis in children with dysbacteriosis in chronic constipation.

The purpose of the study was to investigate hemostasis in children with dysbacteriosis disturbance in chronic constipation. The disturbance of factors in the inner mechanism of blood coagulation (VII, IX, XI, XII) in compensated chronic constipation was defined based on the reduction in colon bacillus levels. We observed hypocoagulation caused by the reduced activity of the prothrombin complex factors, disaggregate thrombocytopathy, and endotheliosis with fibrinolysis inhibition in subcompensated chronic colostasis with continuous reduction of colon bacillus levels and pathogenic microflora appearance. In decompensated colostasis there was an increase in pathogenic microorganisms and a continuous reduction of colon bacillus levels. In hemostasis there was a factor deficiency in inner (XII, XI, IX, VIII) and outer (II, V, VII, X) blood coagulation mechanisms. Fibrinolysis inhibition, endotheliosis development with thrombocyte aggregation, and microthrombosis formation were determined. Thus, in children with chronic constipation, there was a marked reduction in the amount of colon bacillus, which led to the reproduction of pathogenic bacteria. We also observed chronometric hypocoagulation with the inner (XII, XI, IX, VIII) and outer (II, V, VII, X) mechanisms of blood coagulation, at the base of which there is the deficiency of vitamin K-dependent factors (II, VII, IX, X) and a slightly marked disturbance in the final stage of coagulation. In thrombocyte vascular hemostasis, thrombocytopathy was observed with increased adenosine-5-diphosphate aggregation and the inhibition of the inner mechanism with fibrinolysis and endotheliosis.

Adolescent↗