Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ANTITHROMBIN”

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 1,549 records · Page 86Linked to original sources
PubMed2001

Expression and characterization of recombinant human antithrombin III in Pichia pastoris.

Antithrombin III (ATIII) is a member of the serpin superfamily and a major regulator of the blood coagulation cascade. To express recombinant human ATIII (rATIII) in the methylotrophic yeast Pichia pastoris, we constructed an rATIII expression plasmid which contained the ATIII cDNA encoding mature protein region connected with the truncated mAOX2 promoter and the SUC2 secretion signal, introduced it into the P. pastoris genome, and screened for a single copy transformant. The secretion of rATIII from the transformant reached a level of 320 IU/L in the culture broth at 169 h. From the culture-supernatant, rATIII was purified to over 99% by heparin-affinity chromatography and other column chromatography methods. We characterized rATIII and compared it with human plasma-derived ATIII (pATIII). The purified rATIII possessed correct N-terminal amino acid sequence, and its molecular weight by SDS-PAGE of 56,000 Da was slightly different from the 58,000 Da of pATIII. Sequence and mass spectrometry analysis of BrCN fragments revealed that posttranslational modifications had occurred in rATIII. O-linked mannosylation was found at Ser 3 and Thr 9, and in some rATIII molecules, modification with O-linked mannosyl-mannose had probably occurred at Thr 386, close to the reactive center. Although the heparin-binding affinity of rATIII was 10-fold higher than that of pATIII, its inhibitory activity against thrombin was only half. As the conformation of rATIII and pATIII by circular dichroism spectroscopy was similar, O-glycosylation in the reactive center loop was assumed to be mainly responsible for the decreased inhibitory activity. pATIII can inactivate thrombin through formation of a stable thrombin-ATIII complex, but rATIII modified with O-glycosylation in the reactive center loop may act as a substrate rather than an inhibitor of thrombin.

Antithrombin III↗
PubMed1985

Influence of antithrombin III on carbon tetrachloride intoxication of rabbits.

Intraperitoneal application of carbon tetrachloride into rabbits caused high mortality due to liver damage with increase of serum transaminases, coagulation disorders, and decrease of antithrombin III (AT III) blood levels. Groups of animals were treated i.v. either with heparin (200 NIH-U/kg), AT III from human plasma (25 or 50 U/kg), heparin plus AT III (200 NIH-U +25 U/kg), or isotonic saline as control substance 6 hours after intoxication and 2 times daily during the following 5 days (10 applications). The therapy with saline or heparin was ineffective. AT III 25 U/kg and in combination with heparin showed marginal effects, 50 U/kg AT III resulted in increased survival rate and time, improvement of pathological changes of coagulation parameters and of blood urea nitrogen and serum creatinine levels. These experimental results confirmed clinical effects of AT III in acute hepatic intoxications with coagulopathy in humans.

Alanine Transaminase↗
PubMed1992

Genetic studies of antithrombin III with IEF and ASO hybridization.

Antithrombin III (AT III) was analyzed by two different methods. Isoelectric focusing was used to screen 3 different populations (southwest Germans, Portuguese, Xavante Indians). The same variant was detected both in the German and the Portuguese populations with frequencies of 0.007 and 0.00024, respectively. Further characterization of this variant was performed by allele specific oligonucleotides. By this means, it was possible to identify the variant as AT III Dublin, originally found in 4 Irish families.

Antithrombin III↗
PubMed1995

Cellular receptor structures for pseudorabies virus are blocked by antithrombin III.

Pseudorabies virus (PrV), an alphaherpesvirus of swine, uses cellular heparan sulfate residues as a receptor for attachment. Interaction of the virus with its receptor is mediated by the envelope glycoprotein C (PrV-gC), a protein with heparin-binding properties. We have previously shown that a region of this protein shows structural similarities to the high-affinity heparin-binding site of the serum protease-inhibitor antithrombin III (ATII). In this publication, we describe the effect of ATIII on interaction of PrV with its cellular receptor. ATIII bound specifically to heparan sulfate residues on the surface of herpesvirus-permissive RK13 cells. Binding of ATIII to RK13 cells interfered with adsorption of radioactively labelled PrV to these cells. Enzymatic treatment using heparinase I (E.C. 4.2.2.7) removed the receptor for PrV as well as the receptor for ATIII. Since amino acids 130-137 of the high affinity heparin-binding site of ATIII show structural similarities to amino acids 134-141 of PrV-gC, both sequences were synthesized as synthetic peptides. Although interaction of the peptide derived from ATIII with heparin was significantly stronger, both peptides interacted specifically with heparin in assays in vitro. These results suggest that PrV and ATIII interact with the same structure on the cellular surface.

Amino Acid Sequence↗
PubMed1981

The effects of orchiectomy, oestrogens and cyproterone-acetate on the antithrombin-III concentration in carcinoma of the prostate.

The incidence of thromboembolic complications is increased in patients with oestrogen-treated prostatic carcinoma. Because reduced antithrombin-III (AT-III) levels are associated with increased risk of thromboembolism we have determined AT-III concentrations during oestrogen therapy and other treatments. Forty-six patients with carcinoma of the prostate were allocated to either treatment with subcapsular orchiectomy, oestrogen administration, or cyproterone acetate, AT-III was determined before treatment, at 2 weeks and 2 months later. During oestrogen therapy there was a significant reduction in AT-III to 77% of the base-line value. No significant changes were found after orchiectomy. During cyproterone-acetate treatment there was a slight but significant increase in AT-III at 2 months. The reduction in AT-III could indicate an increased risk of thromboembolism during oestrogen treatment of patients with carcinoma of the prostate. On the other hand, the unchanged AT-III levels after orchiectomy and the increased levels during cyproterone acetate therapy could mean that the risk of thromboembolism is less with these two forms of treatment.

Aged↗
PubMed1990

Relationship between angiotensinogen, alpha 1-protease inhibitor elastase complex, antithrombin III and C-reactive protein in septic ARDS.

The time-course of plasma angiotensinogen (Ao), elastase-alpha 1-protease inhibitor complex (EL alpha 1PI), antithrombin III (AT III) and C-reactive protein (CRP) have been investigated of six patients suffering from adult respiratory distress syndrome (ARDS). The total plasma Ao level (active and inactive Ao) varied in individuals but was increased up to five-fold. An increasing amount of inactive Ao is found. From the beginning of their stay in the intensive care unit up to five days half of the patients displayed a positive correlation between the plasma CRP and Ao level. The CRP and Ao values were either not or were negatively correlated with the AT III values. In contrast plasma Ao and AT III levels in all patients were positively correlated during a particular period in the subsequent phase of the disease, where there was no or a negative correlation with CRP. The two acute phase reactants CRP and EL alpha 1PI were only correlated in two patients at the beginning of the disease. The markedly increased plasma level at the beginning of the inflammatory disease indicates that Ao is an acute phase reactant, and this is supported by the parallel changes in plasma CRP and Ao levels during the early days of ARDS. The relationship between the plasma levels of Ao and AT III for more than fourteen days suggests similar regulation of these members of the serpin family after termination of the acute-phase.

Adult↗
PubMed1989

Antithrombin III activity (residual thrombin activity) in plasma from non-medicated or heparinized horses.

Two synthetic substrate assays (fluorometric and chromogenic) were used to measure antithrombin-III (AT-III) activity (residual thrombin activity) in non-medicated and heparin (sodium) treated horses. In 18 non-medicated horses the fluorometric substrate assay (FSA) values were similar to previous reports but they reflected inconsistent trends and larger deviations in the heparin-treated groups (Group 2: 40 and 100 U/kg IV, n = 6; Group 3: 240 U/kg IV, n = 5; Group 4: 80 U/kg IV followed by 160 U/kg SC, n = 8) when compared to the chromogenic substrate assay (CSA) values. The CSA values for the 18 non-medicated horses indicated a higher AT-III activity (lower residual thrombin activity) than the FSA. AT-III activity was quantified in 18 non-medicated horses (29 mg/dl) and compared well with values for humans (30 mg/dl) and dogs (40 mg/dl). Plasma heparin concentrations, determined by the FSA, correlated well with the 'therapeutic range' (1.5 fold to 2.5 fold prolongation of the activated partial thromboplastin time (APTT) normal value) and values reported for humans. The effect of heparin therapy on AT-III activity in four treatment regimens was evaluated. AT-III activity was not significantly affected (with one exception) by a single dose of intravenous (IV) heparin (40 and 100 U/kg) nor by repeated subcutaneous (SC) injections of heparin (240 U/kg). A transient increase in residual thrombin activity was measured 12 h after an intravenous (80 U/kg) injection of heparin. Large doses of heparin (80 U/kg IV followed by 160 U/kg SC) given every 12 h produced a progressive prolongation of the APTT. In this group the APTT remained prolonged 48 h after the last treatment.

Animals↗
PubMed1984

Deficiency of antithrombin III in children with hemolytic-uremic syndrome.

In nine patients with hemolytic-uremic syndrome, the plasma activity and plasma concentrations of antithrombin III were determined on admission to the hospital and during the clinical course of the disease. Hemodialysis was necessary in six of the patients. In seven children the plasma AT III activity was moderately to markedly below the lower limit of normal at 75%, and did not rise after plasmapheresis with fresh frozen plasma. Replacement therapy with AT III concentrate was started in these patients. During the first 2 days an average dose of AT III concentrate of 2.1 U/kg in 24 h was necessary to raise plasma AT III activity by 1%. No side effects were observed. An already pre-existing procoagulant status and the administration of heparin may lead to AT III deficiency in hemolytic-uremic syndrome.

Antithrombin III Deficiency↗
PubMed1984

Plasma elimination of antithrombin III (heparin cofactor activity) is accelerated in term newborn infants.

Antithrombin III (AT III) levels are markedly increased in newborn infants following exchange transfusion with adult blood, and subsequently return to pre-exchange values. This transient rise in AT III (heparin cofactor activity), was used to estimate its plasma elimination half-life. AT III activities were measured serially, before and after double-volume exchange transfusions with heparinised blood in newborn infants requiring therapy for severe hyperbilirubinaemia. The plasma elimination half-life of AT III activity was calculated to be 3.9 +/- 1.4 h (mean +/- SEM). Compared with published data on the kinetics of AT III infusions in adults, the neonate has a considerably accelerated turnover. This finding has important implications for the design of future therapeutic trials of AT III concentrates and provides further evidence that plasma proteins, including components of the coagulation system, appear to have different kinetics in the neonatal period.

Antithrombin III↗
PubMed1989

Low antithrombin III: accurate predictor of idiopathic respiratory distress syndrome in premature neonates.

A prospective study was performed in premature neonates to determine the predictive values of antithrombin III (AT III) deficiency immediately after birth, for the subsequent development of idiopathic respiratory distress syndrome (IRDS), intraventricular haemorrhage (IVH) and death. Of the 81 premature infants studied, 24 developed IRDS (30%). Of these 24 premature infants, 8 also developed IVH and 9 infants died within the follow-up period of 7 days. The mean plasma AT III level was significantly lower in the infants developing IRDS (0.23 U/ml vs 0.35 U/ml, P less than 0.0005). Within this study group 33 neonates of less than 30 weeks' gestation showed a prevalence for IRDS of 48%. In this group, AT III activity levels below 0.30 U/ml were 8.5 times as likely to result from infants with IRDS than from infants without IRDS. The diagnostic accuracy indices of criteria for the development of IRDS were: a sensitivity of 100%, a specificity of 88%, a positive predictive value of 89% and a negative predictive value of 100%. The predictive values for the development of IVH and occurrence of death were insignificant. Therefore, in premature neonates the combination of less than 30 weeks' gestation and an AT III below 0.30 U/ml is highly suggestive of IRDS and may facilitate the evaluation of early treatment.

Antithrombin III↗
PubMed1989

Antithrombin III in children with various renal diseases.

Levels of antithrombin III (AT-III) activity and antigen in plasma and urine in children with renal diseases, and their correlation with the light microscopic findings of kidney tissue and the fluorescence of glomeruli, were investigated. AT-III activity in plasma was reduced slightly during the acute stage of acute glomerulonephritis and moderately in the relapse stage of nephrotic syndrome, whereas a small increase of AT-III antigen level in urine was noted in the acute stage of glomerulonephritis and considerably more was observed during the relapse stage of nephrotic syndrome. During the acute stage of glomerulonephritis or in some primary persistent glomerulonephritis (IgA nephritis, non-IgA nephritis), Henoch-Schönlein purpura nephritis and nephrotic syndrome, localization of small amounts of AT-III was noted on the capillary walls of glomeruli. These findings were in parallel with the proliferative changes of glomeruli. However, the AT-III localization did not change in parallel with the light microscopic findings or degree of the fluorescence of the fibrinogen/fibrin-related antigen. It was thought that the existence of AT-III antigen on the capillary walls of the glomeruli might be associated with the inhibition of excessive fibrin formation by AT-III.

Acute Disease↗
PubMed1992

Recurrent renal vein thrombosis and renal failure associated with antithrombin-III deficiency.

This paper describes a healthy 13-year-old girl presenting with acute flank pain and anuria due to renal vein thrombosis. A similar spontaneous and unexplained thrombosis resulted in the loss of the contralateral kidney 1 year earlier. Urgent surgical thrombectomy and anticoagulation resulted in moderate recovery of renal function. Predisposition to venous thrombosis in this child was secondary to a marked familial deficiency of circulating antithrombin-III. An early diagnosis of this condition is essential for the formulation of preventive measures and may lead to specific therapeutic intervention at the onset of acute thrombotic complications.

Acute Kidney Injury↗
PubMed1991

The complete amino acid sequence of bovine antithrombin (ATIII).

Bovine antithrombin (ATIII) is a glycoprotein of Mr 56,600. Its primary structure was established using peptide sequences from five different digests. Bovine ATIII exhibits four glcosylation sites as well as human ATIII. The primary structures of bovine and human ATIII were compared: all the residues required for the integrity of the heparin-binding domain are strictly conserved. However, there are differences in the secondary structures of both proteins, bovine and human ATIII.

Alkylation↗
PubMed1993

Interaction of thrombin with antithrombin, heparin cofactor II, and protein C inhibitor.

alpha-Thrombin is a trypsin-like serine proteinase involved in blood coagulation and wound repair processes. Thrombin interacts with many macromolecular substrates, cofactors, cell-surface receptors, and blood plasma inhibitors. The three-dimensional structure of human alpha-thrombin shows multiple surface "exosites" for interactions with these macromolecules. We used these coordinates to probe the interaction of thrombin's active site and two exosites, anion-binding exosite-I and -II, with the blood plasma serine proteinase inhibitors (serpins) antithrombin (AT), heparin cofactor II (HC), and protein C inhibitor (PCI). Heparin, a widely used anticoagulant drug, accelerates the rate of thrombin inhibition by AT, PCI, and HC. Thrombin Quick II is a dysfunctional thrombin mutant with a Gly 226-->Val substitution in the substrate specificity pocket. We found that thrombin Quick II was inhibited by HC, but not by AT or PCI. Molecular modeling studies suggest that the larger Val side chain protrudes into the specificity pocket, allowing room for the smaller P1 side chain of HC (Leu) but not the larger P1 side chain of AT and PCI (both with Arg). gamma T-Thrombin and thrombin Quick I (Arg 67-->Cys) are both altered in anion-binding exosite-I, yet bind to heparin-Sepharose and can be inhibited by AT, HC, and PCI in an essentially normal manner in the absence of heparin. In the presence of heparin, inhibition of these altered thrombins by HC is greatly reduced compared to both AT and PCI. alpha-Thrombin with chemically modified lysines in both anion-binding exosite-I and -II has no heparin accelerated thrombin inhibition by either AT or HC. Thrombin lysine-modified in the presence of heparin has protected residues in anion-binding exosite-II and the loss of heparin-accelerated inhibition by HC is greater than that by AT. Collectively, these results suggest differences in serpin reactive site recognition by thrombin and a more complicated mechanism for heparin-accelerated inhibition by HC compared to either AT or PCI.

Allosteric Site↗
PubMed1992

Protective effect of antithrombin III in acute experimental pancreatitis in rats.

In the present study we investigated the therapeutic action of antithrombin III (AT III) in taurocholate-induced experimental pancreatitis with high lethality in rats. High-dose AT III treatment greatly improved the survival rate not only when given as pretreatment but also when given 2 hr after induction. No favorable effect on survival rate was observed on administration after 5 hr. Both intravascular and intraperitoneal AT III administration locally restored decreased AT III levels in the peritoneal cavity and increased plasma AT III to supranormal levels. The primary pancreatic insult seemed to be unaffected by the treatment, because neither the rise in plasma lipase nor the development of ascites or the extension of the pancreatic necrosis were diminished. Because heparin pretreatment of the rats was also effective, the mechanism of the beneficial action was probably mediated by inhibition of the proteases of the coagulation cascade, thereby preventing intravascular coagulation in the pancreas and distant organs and subsequent systemic complications. The high efficacy of AT III treatment in this experimental model may stimulate clinical studies evaluating the efficacy of AT III treatment in an early stage of acute pancreatitis.

Acute Disease↗
PubMed1993

Influence of blood sampling from venipunctures and catheter systems on serial determinations of prothrombin activation fragment 1 + 2 and thrombin-antithrombin III complex.

To evaluate the influence of different blood sampling techniques on test results of thrombin-antithrombin III complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2) serial determinations were performed. In six groups of nonrandomized patients (ten patients each) the concentrations of the coagulation markers of blood samples from central catheters (internal jugular, caval, Shaldon, pulmonary artery) and peripheral cannulas (17G and 18G) were compared with those of blood samples obtained simultaneously from direct venipunctures of the contralateral arm. Medians and 25th-75th percentiles of TAT and F1 + 2 concentrations of plasmas obtained from central catheters were not different from those taken from venipunctures. When delta mean values (catheter - venipuncture) were calculated negative results were obtained, indicating lower concentrations measured from blood sampled through central catheters with the exception of blood that taken from Shaldon catheters. Only for TAT concentrations significantly were lower values measured in blood samples taken from internal jugular catheters when compared with blood samples obtained from direct venipunctures. Significantly higher TAT concentrations were determined in blood samples obtained from Shaldon catheters. For both coagulation markers correlations were found between concentrations in blood samples from central catheters and venipunctures. In blood samples taken from peripheral venous cannulas only F1 + 2 concentrations correlated with the concentrations found in samples from direct venipuncture. In contrast to F1 + 2, TAT concentrations measured from blood samples via peripheral cannulas were determined significantly higher than those taken from direct venipunctures.(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗
PubMed1984

[Antithrombin III changes following myocardial infarct].

The antithrombin III (AT III) activity and the AT III concentration were investigated in 62 consecutive patients with acute myocardial infarction (AMI). To identify the reactant pattern of AT III in postaggressive situations, we also determined labile and acute phase proteins. Firstly, 29 patients were nourished orally and then 33 patients were fed by i.v. hyperalimentation (additional caloric intake of approximately 1,000 cal). AT III activities and concentrations as well as prealbumin and retinol-binding protein decreased concomittantly and significantly whereas haptoglobin, C-reactive protein and fibrinogen increased significantly after AMI. The changes cannot be interpreted as being alterations of the haematocrit. The alterations of AT III correlated significantly with the changes of labile proteins but not with the acute phase reactant proteins. The AT III decrease in the postinfarctional phase may promote a prethrombotic state. In addition it can be concluded from our results that AT III reacts as (nutritive-dependent) labile protein, which is lowered in postaggressive situation and does not increase as an acute phase reactant. This is in accordance with results from recent animal experiments.

Antithrombin III↗