PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ANTITHROMBIN”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,027 records · Page 57Linked to original sources

[Antithrombin III activity in long-developing hypercoagulation in animals].

Old rats aged 12-18 months and rats kept on an atherogenic diet for 3.5 months demonstrate high blood antithrombin III content at the initial period of the development of anticoagulation function suppression and of hypercoagulation. During long-developing hypercoagulation, the high content of antithrombin III might be regarded as compensatory reaction interfering with formation in the blood of thrombin microamounts. With hypercoagulation becoming more pronounced and with a further increase of blood thrombin concentration the content of antithrombin III progressively descends, which is accompanied by steady development of anticoagulation function suppression.

Aging↗

[Changes in antithrombin III values during and after extracorporeal circulation in heart surgery, measured on the day of operation using a chromogenic substrate and a laser nephelometer].

The changes in antithrombin III in 31 patients who underwent open-heart surgery were measured during the period of extracorporeal circulation and afterwards over a total period of 24 hours by means of a chromogenic substrate, as well as by laser nephelometry. Both the actual changes in antithrombin III, as well as the theoretical changes calculated by eliminating the effect of haemodilution are discussed. The functional test indicates that the loss of antithrombin-III activity, in general, is due to the effect of haemodilution. However, marked individual differences were noted in the reaction pattern. The results of nephelometric measurements were inconsistent and seemed to indicate that routine procedures in laser nephelometry are hardly suitable for the purpose of comparison of samples with marked haematocrit differences.

Antithrombin III↗

The reversible antithrombin activity of incubated plasma.

The thrombin time of normal citrated plasma is progressively prolonged on incubation in open glass tubes at 37 degrees C. The phenomenon is dependent on the temperature and duration of incubation, on the pH, and on the concentration of calcium ions present. Platelet-rich citrated plasma fails to exhibit augmented antithrombin activity when similarly incubated, and the addition of washed platelets to platelet-poor plasma inhibits this activity. The clot retarding action of incubated plasma against thrombin is also manifested against Arvin (Ancrod), but not against Reptilase-R. This thrombin time lengthening may be inhibited by incubation with anti-antithrombin III antiserum thus indicating that the phenomenon of thrombin time lengthening is consistent with enhanced activity of antithrombin III. It is unlikely that alterations in the activity of alpha2-macroglobulin, is important in the reduced thrombin-coagulability of incubated plasma. Interference with the polymerisation of fibrin monomers by the physico-chemical changes may contribute to the observed phenomenon.

Ancrod↗

[Therapy of patients with severe liver insufficiency using antithrombin III and plasma derivatives].

The treatment of three patients suffering from carbon tetrachloride intoxication with antithrombin III and plasma derivatives is reported. In these patients an acute liver failure had been proven, characterized by a disturbed protein synthesis and a severe haemostasis defect. The latter manifested itself by a consumption of platelets, clotting enzymes and the inhibitors antithrombin III and alpha 2-antiplasmin. It was due to an intravascular coagulation leading to disturbances in the microcirculation. This often letal circulus vitiosus could be stopped in these patients by treatment with antithrombin III concentrate combined with low dose heparin and fresh frozen plasma. Clinical improvements are discussed on the basis of the pathophysiology of the liver.

Adult↗

The heparin-binding site of antithrombin III. Identification of a critical tryptophan in the amino acid sequence.

Chemical modification of a single tryptophan residue in antithrombin III with dimethyl(2-hydroxy-5-nitrobenzyl)sulfonium bromide blocks heparin binding and the heparin-enhanced inhibition of thrombin without altering the heparin-independent rate of thrombin inhibition (Blackburn, M. N., and Sibley, C. C. (1980) J. Biol. Chem. 255, 824-826). The labeled protein was reduced and carboxymethylated and then cleaved with cyanogen bromide. The peptide containing the hydroxynitrobenzyl-labeled tryptophan was isolated by gel filtration and ion exchange chromatography. Amino acid analysis of the labeled peptide indicates that it corresponds to residues 21 through 89 of human antithrombin III. The site of labeling corresponds to Trp 49, which is located within the disulfide-stabilized loops near the NH2-terminal end of the antithrombin III molecule.

Amino Acid Sequence↗

Inhibition of urokinase by complex formation with human antithrombin III in absence and presence of heparin.

Human antithrombin III was purified from fresh human plasma by affinity chromatography on heparin-Sepharose, affinity chromatography on concanavalin A Sepharose, gel filtration on Ultrogel AcA 34, ion exchange chromatography on DEAE A-50 Sephadex and preparative agarose gel electrophoresis. The hydrolytic activity of urokinase (plasminogen activator from urine) on acetyl-glycyl-L-lysine methylester acetate (Ac-gly-lys-OMeAc) was inhibited by antithrombin III in a slow time-dependent manner. Heparin accelerated the reaction between activator and inhibitor. Inhibition of catalytic activity was associated with the formation of an 1:1 molar complex between activator and inhibitor as revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The complex was also demonstrated by crossed immunoelectrophoresis against anti-antithrombin III.

Antigen-Antibody Complex↗

[Antithrombin III in infantile nephrotic syndrome].

In the Nephrotic Syndrome an hypercoagulable state can cause an increased incidence of thromboembolic phenomena and the course of the syndrome. The deficiency of Antithrombin III has been suggested to explain the hypercoagulability. We measured plasma antithrombin concentration (as percentage) in 24 children suffering from N.S. and the values were correlated with serum albumin, proteinuria and Partial Thromboplastin Time (PTT). The results of this study show that plasma Antithrombin III (AT-III) is significantly correlated with serum albumin, with proteinuria and PTT. Moreover plasma AT-III concentration was found to be low particularly when patients relapsed and in 2 children who developed thombophlebitis of the safena vein.

Adolescent↗

Surgical implications of antithrombin III deficiency.

Antithrombin III is a potent coagulant inhibitor in plasma. Congenital deficiency of antithrombin III may predispose to thrombotic events and may complicate surgical management. We describe a patient with congenital antithrombin III deficiency who developed superior mesenteric vein thrombosis after the cessation of warfarin therapy which resulted in venous gangrene of the small intestine. Initial treatment of this deficiency with fresh frozen plasma and subsequent long-term management with warfarin therapy has been effective in avoiding further thrombotic events.

Adult↗

Thermal denaturation of antithrombin III. Stabilization by heparin and lyotropic anions.

Antithrombin III is of potential value for replacement therapy in patients with acquired or congenital deficiencies. Pasteurization of the purified inhibitor for 10 h at 60 degrees C can reduce the risk of transfusion hepatitis. Addition of appropriate stabilizers can largely prevent the loss of antithrombin activity which otherwise occurs during pasteurization. Studies of the mechanism of denaturation and stabilization have been facilitated by the use of 8-anilino-1-naphthalene sulfonate which binds weakly to the inhibitor and whose fluorescence undergoes a sigmoidal response to increasing temperature. The extent of the increase in 8-anilino-1-naphthalene sulfonate fluorescence correlates roughly with the loss of antithrombin activity and with the extent of protein aggregation as determined by high pressure liquid chromatography. The midpoint, Td, of the thermal denaturation curve increases by 13 degrees C and 19 degrees C in the presence of 0.5 M and 1.0 M sodium citrate, respectively. Phosphate, sulfate, and EDTA are also strong stabilizers while the chaotropic anions, iodide and thiocyanate are potent destabilizers. Heparin at 10 mg/ml increases Td by 7 degrees C, presumably through a direct binding mechanism; chondroitin sulfate and hyaluronic acid have no effect. Samples pasteurized for 10 h at 60 degrees C in the presence of 0.5 M and 1.0 M citrate retain essentially full activity but exhibit evidence of minor alterations in their interaction with heparin.

Anilino Naphthalenesulfonates↗

Antithrombin III deficiency appearing as mesenteric vein thrombosis.

Mesenteric vein thrombosis is a relatively uncommon but devastating problem. Absence of any of the generally accepted etiologic factors of mesenteric vein thrombosis has lead to the diagnosis of "primary" mesenteric vein thrombosis in 25-55% of all cases. In this report we identify a young man with antithrombin III deficiency presenting as "primary" mesenteric vein thrombosis with massive bowel infarction. It again raises the possibility that other cases of "primary" mesenteric vein thrombosis may have been associated with this coagulopathy. Factors influencing antithrombin III levels are discussed in relation to diagnosis of the familial deficiency state in a patient with mesenteric vein thrombosis. The association of intra-abdominal venous occlusion and antithrombin III deficiency is emphasized.

Adult↗

[Epidemiological evaluation of thromboembolic risk. Critical review of the prospects offered by determination of antithrombin III].

Authors review the epidemiology of deep venous thrombosis and the prothrombotic state in high risk patients; particularly antithrombin III role in blood clotting is considered. A fall in antithrombin III concentration and/or activity can induce hypercoagulability and thrombosis. Moreover authors stress the need to evaluate antithrombin III as anti-Xa activity, to detect high risk patients for deep venous thrombosis.

Antithrombin III↗

[Antithrombin III level on the intravenous injection of tissue thromboplastin and heparin to rats with depressed blood anticoagulating system function due to an atherogenic diet].

Rats with depressed function of the blood anticoagulation system due to an atherogenic diet had a slightly reduced level of antithrombin III by the sixth month of the diet as compared to the indices of control animals. Intravenous injection of tissue thromboplastin revealed delayed and incomplete binding of thrombin by antithrombin III in the experimental animals, which was characterized by only an insignificant decrease in the level of the inhibitor as compared to its change in control animals kept under similar experimental conditions. Preliminary intravenous injection of small doses of heparin into animals with depressed function of the anticoagulation system and low level of heparin in blood stimulates and promotes the binding of thrombin by antithrombin III under conditions of increased thrombinogenesis following intravenous injection of tissue thromboplastin.

Animals↗

Plasma antithrombin III activity in normal pregnancy.

The incidence of thromboembolic phenomena increases in pregnancy. Antithrombin III has been implicated as a possible etiologic factor for the increase of thromboembolic phenomena in women receiving exogenous estrogens. In a study of normal obstetric, postpartum, and oral contraceptive patients, no significant change in antithrombin III activity could be detected in a plasma-based assay within and among these groups. It is hypothesized that a decrease in antithrombin III activity is not a cause of increased thromboembolic phenomena during normal pregnancy and oral contraceptive use.

Antithrombin III↗

[Familial thromboembolic disease associated with antithrombin III deficiency (author's transl)].

The authors report the observation of a new kindred with hereditary antithrombin III deficiency. In the last three generations, the family comprised 10 subjects, 7 of whom were affected: the grandmother had recurrent thrombophlebitis; her three sons died from pulmonary embolism at 22, 26 and 28 respectively and her daughter had repeated bouts of thrombophlebitis. In patients with hereditary antithrombin III deficiency, venous thrombosis occurs under similar conditions as, and is clinically similar to, thrombosis in patients without this defect. Usual tests of hemostasis are normal. The diagnosis is however suspected through an history of recurrent episodes and of similar cases in relatives. The diagnosis is confirmed by demonstration of low levels of antithrombin III in suspected patient and family. The disease is transmitted as autosomic dominant trait. Heparin is ineffective but oral anticoagulants may prevent occurence or recurrence of thrombosis in patients with this genetic defect.

Adult↗

Fibrinogen inhibits the heparin cofactor II-mediated antithrombin activity of dermatan sulfate.

Dermatan sulfate is a naturally occurring antithrombotic glycosaminoglycan. The antithrombin activity of several dermatan sulfate preparations has been measured in whole human plasma and found to be -55% of that in purified systems. Kinetic studies under pseudo-first-order conditions indicated that the reduction in antithrombin activity of dermatan sulfate in plasma compared with that in buffer was due to noncompetitive inhibition with respect to dermatan sulfate. Analysis of the protein profile bound to immobilized dermatan sulphate showed that on a molar basis, histidine-rich glycoprotein and apolipoprotein E were the most abundant proteins specifically bound, together with significant amounts of fibrinogen and vitronectin. Addition of these proteins to the purified system showed that only fibrinogen inhibited the antithrombin activity of dermatan sulfate and that it did so in a concentration-dependent manner over the physiologic range of plasma fibrinogen levels. These results indicate that the anticoagulant activity of dermatan sulfate may be modulated in human plasma by fibrinogen.

Animals↗

[Renal pathology in the Ivory Coast: exploration and functional activity of antithrombin iii].

Antithrombin III activity was determined in 96 ivorian adults clinically divided into 3 groups: I) nephrotic syndrome, II) chronic renal failure, and III) terminal uremia requiring maintenance dialysis. In the nephrotic syndrome, a significative decrease of antithrombin III is found, which can explain the existence of thrombotic complications. In chronic renal failure and terminal uremia, antithrombin III activity is normal, and thromboembolic events may be related to a deficiency of other inhibitors of the coagulation.

Adolescent↗

Antithrombin III enhances the motility and chemotaxis of boar sperm.

Purified porcine antithrombin III stimulates motility and acts as a chemoattractant of washed boar sperm. Porcine follicular fluid and blood plasma both possess chemotactic activity. Porcine antithrombin III-immunoreactive molecules are distributed on the zona pellucida of ovulated eggs flushed from the swine oviducts. We propose that antithrombin III plays important roles in the mammalian fertilization process in vivo.

Animals↗

Autoantibodies to heparin from patients with antiphospholipid antibody syndrome inhibit formation of antithrombin III-thrombin complexes.

The antiphospholipid antibody syndrome (APS) is characteristically associated with thrombosis. Heparan sulfate (HS) is a physiologic endothelial cell surface modulator of normal anticoagulation, containing a specific oligosaccharide sequence that binds antithrombin III with high affinity and also is present in heparin, a related glycosaminoglycan. We hypothesized that a subset of antiphospholipid antibodies with high affinity for heparan sulfate/heparin epitopes may inhibit the function of HS, promoting a procoagulant state. Purified IgG from all seven patients with APS studied were reactive with heparin by enzyme-linked immunosorbent assay, whereas none of five controls had antiheparin reactivity. IgG antiheparin antibodies were purified from two APS patients by affinity chromatography on heparin-Sepharose. Specificity studies showed that low-affinity electrostatic interactions clearly did not account for the observed reactivity with heparin, and that APS IgG antiheparin antibodies were specifically reactive with a disaccharide present in the heparin pentasaccharide that binds antithrombin III. Furthermore, APS IgG antiheparin antibodies inhibited heparin-accelerated formation of antithrombin III-thrombin complexes. We conclude that antiheparan sulfate/heparin antibodies may be a cause of autoimmune vascular thrombosis in the antiphospholipid antibody syndrome.

Adult↗