Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FIBRINOLYSIS”

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 37 records · Page 2Linked to original sources
PubMed1989

[AL amyloidosis and primary fibrinolysis. Study of the mechanism of fibrinolysis].

A 45 years old woman with AL amyloidosis presented with a hypofibrinogenemia (fibrinogen 100 mg/dl) without severe bleeding. There was laboratory evidence of fibrinolysis with shortened euglobulin lysis time, decreased alpha-2 plasmin inhibitor and decreased plasminogen. The mechanism of this primary fibrinolysis remains unclear, since there is no enhancement of the tissue-type plasminogen activator. Analysis of the 8 cases related in the literature of excessive fibrinolysis associated with amyloidosis demonstrated improvement of bleeding manifestations and abnormal fibrinolysis following the administration of antifibrinolytic agents.

Amyloid↗
PubMed1996

Coagulation, fibrinolysis and fibrinolysis inhibitors in haemodialysis patients: contribution of arteriovenous fistula.

BACKGROUND: End-stage renal disease (ESRD) patients, not uncommonly, might exhibit thrombotic complications, as well as they may present with a bleeding diathesis. Changes in vessel wall and/or blood flow in native arteriovenous fistula (AVF) might also augment these disarrangements, as vascular endothelium is predominantly involved in the regulation of haemostatic pathways. OBJECTIVE: This study was designed to evaluate the state of coagulation and fibrinolysis and the role of AVF on haemostatic defects, in ESRD patients on maintenance haemodialysis. METHODS: Plasma samples for prothrombin fragment 1+2, thrombin-antithrombin III complex, plasmin-alpha2 antiplasmin complex, tissue type plasminogen activator antigen, urokinase type plasminogen activator antigen, u-PA activity, plasminogen activity, alpha2-antiplasmin and alpha2-macroglobulin assays were obtained from AVF and contralateral large veins of ESRD patients and from peripheral veins of the control group. RESULTS: Our results indicate a predominant thrombotic state as evidenced by activated coagulation markers and enhanced fibrinolysis in systemic circulation of ESRD patients. However the most novel finding is the probable contribution of AVF on haemostatic activation, as proven by the statistically different and positively correlated concentrations of both coagulation, fibrinolysis, and fibrinolysis inhibitors in AVF when compared to the levels in peripheral venous circulation. CONCLUSION: In addition to systemic derangements of haemostasis in ESRD patients, AVF individually might have a substantial role in the modulation of coagulation and fibrinolytic cascade.

Adult↗
PubMed2003

Deficiency of thrombin activatable fibrinolysis inhibitor in cirrhosis is associated with increased plasma fibrinolysis.

Hyperfibrinolysis is thought to contribute to bleeding associated with advanced cirrhosis. Thrombin activatable fibrinolysis inhibitor (TAFI) is a plasma precursor of a carboxypeptidase (TAFIa) with antifibrinolytic activity and was recently shown to be reduced in cirrhosis. In this study, we evaluated the influence of TAFI deficiency on in vitro fibrinolysis in cirrhotic patients. Fifty-three patients with cirrhosis and 43 healthy controls were studied. TAFI antigen was measured by enzyme-linked immunosorbent assay and TAFI activity by chromogenic assay. Fibrinolysis was evaluated as tissue plasminogen activator-induced plasma clot lysis time in the absence and in the presence of a specific inhibitor of TAFIa. TAFI antigen and activity levels were markedly reduced in cirrhotic patients (P <.0001). In these patients, the lysis time of plasma clots was shorter than in controls (median, interquartile range: 25 minutes, 21-36 minutes vs. 48 minutes, 40-60 minutes, respectively; P <.0001) and was poorly influenced by the TAFIa inhibitor. Accordingly, TAFIa and thrombin activity, generated in cirrhotic samples during clot lysis, were significantly lower than in control samples. Addition of purified TAFI to cirrhotic plasma prolonged the lysis time and enhanced the response to TAFIa inhibitor in a dose-dependent manner. In conclusion, our results indicate that in vitro plasma hyperfibrinolysis in cirrhosis is largely due to a defective TAFIa generation resulting from low TAFI levels and probably from impaired thrombin generation. Impairment of the antifibrinolytic TAFI pathway might contribute to bleeding associated with this disease.

Adult↗
PubMed2005

Demonstration of enhanced endogenous fibrinolysis in thrombin activatable fibrinolysis inhibitor-deficient mice.

To investigate the importance of thrombin activatable fibrinolysis inhibitor (TAFI) in the stabilization of plasma clots, we have compared fibrinolysis in TAFI-deficient (KO) and wild-type (WT) littermate mice. TAFI-deficient mice were previously generated by targeted gene disruption. The level of TAFI activity generated in plasma from WT mice in the presence of added thrombin and thrombomodulin (activatable TAFI) is twice that of plasma from TAFI heterozygous mice (HET); no activatable TAFI is detected in TAFI KO plasma. In vitro, TAFI KO plasma clots lysed faster than WT plasma clots, and HET plasma clots lysed at an intermediate rate. The rate of clot lysis for KO mice is not changed in the presence of potato carboxypeptidase inhibitor, a specific inhibitor of TAFIa, whereas the WT and HET clot lysis rates are increased in the presence of potato carboxypeptidase inhibitor. C-terminal lysine residues are preserved on partially degraded clots from KO mice, but are absent from partially degraded WT clots. In vivo, in a batroxobin-induced pulmonary embolism model, KO mice displayed a lower retention of fibrin in the lungs than did WT mice. These results are the first demonstration of enhanced endogenous fibrinolysis in an in vivo model without the addition of exogenous thrombolytic.

Animals↗
PubMed2003

Activated thrombin-activatable fibrinolysis inhibitor attenuates spontaneous fibrinolysis of batroxobin-induced fibrin deposition in rat lungs.

Studies have shown that inhibition of TAFI by small peptides enhances pharmacological effects of tPA in animal models of thrombosis, suggesting that TAFI modulates the fibrinolytic system. In this study, we investigated the effect of activated human TAFI (TAFIa) on endogenous fibrinolysis in a rat model of intravascular fibrin deposition. (125)I-labeled fibrinogen was injected intravenously followed by a bolus injection of batroxobin, a thrombin-like enzyme. Batroxobin cleaved fibrinogen to form insoluble fibrin that was deposited in tissues, including the lungs. This was shown by a decrease of radioactivity in the blood as a result of consumption of (125)I-labeled fibrinogen and an elevation of radioactivity in the lungs 5 min following batrox-obin administration. Endogenous fibrinolysis was detected by a gradual increase in radioactivity in the blood and a decrease in radioactivity in the lungs at 30 min, an indication of radiolabeled fibrin degradation products (FDPs) being released into the circulation from the tissues. Intravenous administration of human TAFIa dose-dependently attenuated the later phase reduction of radioactivity in the lungs. When the dose of TAFIa was 218 micro g/kg, giving a peak plasma level of TAFIa 0.9 +/- 0.05 micro g/ml, the spontaneous fibrinolysis was completely prevented. These results provide direct evidence that an increase in circulating TAFIa impairs endogenous clot lysis in a rat model of fibrin deposition.

Animals↗
PubMed2007

A novel inhibitor of activated thrombin activatable fibrinolysis inhibitor (TAFIa) - part II: enhancement of both exogenous and endogenous fibrinolysis in animal models of thrombosis.

We have discovered a novel small-molecule TAFIa inhibitor, BX 528, which is potent, highly selective against other carboxypeptidases and safe. The present study was to determine if BX 528 can enhance exogenous and endogenous thrombolysis in four different animal models. In the first three models, a thrombus was induced by FeCl (2) (dogs) or laser (rats) injury of the femoral artery, or formed ex vivo and implanted in the jugular vein in rabbits. A low dose of exogenous t-PA was given to induce a low-level thrombolysis on an established thrombus. Co-treatment with BX 528 further enhanced the thrombolytic effects induced by the exogenous t-PA and, thus, reduced thrombosis in all three animal models. In a second rat model, fibrin deposition in the lungs was induced by batroxobin, which was spontaneously resolved in 30 minutes due to the activation of endogenous fibrinolysis. Pre-treatment with lipopolysaccharide (LPS) attenuated this spontaneous fibrinolysis. Co-treatment with 10 mg/kg BX 528 prevented the LPS-induced attenuation of endogenous fibrinolysis. Thus, these studies demonstrated that inhibition of TAFIa by BX 528, our newly discovered small-molecule TAFIa inhibitor, enhanced both the exogenous (induced by a low dose of t-PA) and endogenous (LPS-induced resistance) thrombolysis without increasing the bleeding risk in four different animal models of thrombosis in different species (rat, dog and rabbit) employing different thrombogenic stimuli (FeCl (2) , laser, ex vivo and batroxobin) to induce thrombus formation in different tissues (artery, vein and lung microcirculation).

Animals↗
PubMed1993

[Conventional local intra-arterial fibrinolysis, spray lysis and mechanically accelerated fibrinolysis. An assessment of their position in the spectrum of angioplasty technics].

Intra-arterial local fibrinolysis was performed in 72 patients (51 men, 21 women, mean age 66.8 years) during the course of 78 angioplasties. 11.1% were stage IIa (Fontaine), 38.9% were stage II b, 27.8% were stage III and 22.2% were stage IV. The methods used were conventional fibrinolysis (15.4%), spray lysis (47.4%) and mechanically accelerated fibrinolysis (37.2%). In 66.7% the urokinase dose was < 600,000 I.U., in 17.9% it was > 1,000,000 I.U. Additional balloon dilatation was performed in 72 cases, percutaneous aspiration of thrombo-embolic material in 41 cases and stent implantation in 7 cases. Angiographically the procedure was successful in 90.7%; the Doppler index rose from 0.47 +/- 0.27 to 0.85 +/- 0.3 (p < 0.001). At discharge, staging was: I = 38.9%, IIa = 38.9%, IIb = 5.6%, III = 1.4%, IV = 15.3%. There were no systemic bleeding complications. In 5.1%, complications had to be treated surgically.

Adult↗
PubMed2005

Metabolic syndrome accompanied by hypercholesterolemia is strongly associated with proinflammatory state and impairment of fibrinolysis in patients with type 2 diabetes: synergistic effects of plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor.

OBJECTIVE: To determine whether plasma concentrations of thrombin-activatable fibrinolysis inhibitor (TAFI) in patients with type 2 diabetes were associated with components of metabolic syndrome (MS), including high-sensitivity C-reactive protein (hs-CRP), plasminogen activator inhibitor (PAI)-1, and LDL cholesterol. RESEARCH DESIGN AND METHODS: We studied 136 consecutive patients with type 2 diabetes. Diagnosis of MS was diagnosed by current criteria. Hypercholesterolemia (HC) was defined as serum LDL cholesterol >140 mg/dl (3.6 mmol/l) or treatment with a statin. For comparisons, diabetic patients were divided into four groups: those with no MS and no HC (n = 38), with MS but not HC (n = 39), with no MS but with HC (n = 26), and with both MS and HC (n = 33). RESULTS: Considering all patients with type 2 diabetes, plasma PAI-1 was strongly associated with MS components such as BMI, triglyceride, alanine aminotransferase, a homeostasis model assessment of insulin resistance, and hs-CRP. Plasma TAFI only correlated positively and independently with LDL cholesterol. Plasma concentrations of plasmin-alpha2-antiplasmin complex (PAP), a measure of fibrinolytic activity in blood, showed a significant negative correlation with plasma PAI-1 but not TAFI. Diabetic patients with both MS and HC had the highest serum hs-CRP concentrations and the lowest plasma PAP concentrations. CONCLUSIONS: LDL cholesterol is a main determinant of plasma TAFI in patients with type 2 diabetes. Coexistence of MS and HC synergistically accelerates inflammation and impairment of fibrinolysis via elevated concentrations of both TAFI and PAI-1, which inhibit fibrinolysis.

Adult↗
PubMed2002

Overall haemostatic potential can be used for estimation of thrombin-activatable fibrinolysis inhibitor-dependent fibrinolysis in vivo and for possible follow-up of recombinant factor VIIa treatment in patients with inhibitors to factor VIII.

Thrombin generation induced by recombinant factor VIIa (rFVIIa) in patients with haemophilia and/or inhibitors to factor VIII/IX could enhance generation of thrombin-activatable fibrinolysis inhibitor (TAFI), a recently described link between coagulation and fibrinolysis. TAFI is unstable and it is not easy to measure its active form in vivo. Overall haemostatic potential (OHP) is a novel method for haemostasis estimation, based on determination of the fibrin aggregation curve in which tiny amounts of thrombin are used for activation of clotting. We measured OHP in six patients with inhibitors to factor VIII before injection of rFVIIa and 10 and 120 min thereafter. Overall fibrinolytic potential (OFP) and clot lysis time (CLT) analysed by this method could be used for indirect estimation of TAFI generation. We found no change in pro-TAFI and total TAFI antigen before and after treatment with rFVIIa. OHP was almost undetectable before treatment but increased into the range of normal pooled plasma 10 and 120 min after rFVIIa treatment, as did CLT. However, after addition of potato tuber carboxypeptidase inhibitor, a specific inhibitor of TAFI, the shortening of CLT was lower than that in NPP. OFP was increased in patient plasma both 10 and 120 min after treatment compared with NPP. There was a strong positive correlation between pro-TAFI concentration and shortening of CLT after PTCI addition and a negative correlation between pro-TAFI concentration and OFP 10 min after rFVIIa injection. Thus, rFVIIa normalizes OHP and CLT 10 min after injection. While this improvement slightly decreases, but still exists after 2 hours, it suggests efficacy in bleeding prevention using a protocol based on rFVIIa administration every 2 hours.

Carboxypeptidase B2↗
PubMed2002

Blood coagulation and fibrinolysis in acute ischaemic and haemorrhagic (intracerebral and subarachnoid haemorrhage) stroke: does decreased plasmin inhibitor indicate increased fibrinolysis in subarachnoid haemorrhage compared to other types of stroke?

Ischaemic and haemorrhagic stroke may cause haemostatic abnormalities, apart from concomitant brain damage. In this study, some blood coagulation and fibrinolysis parameters were investigated in 30 patients with ischaemic stroke (atherothrombotic) and 30 with haemorrhagic (20 with intracerebral and 10 with subarachnoid haemorrhage) stroke. The following parameters were determined within the first 24h after stroke: prothrombin time (PT%). activated partial thromboplastin time (aPTT). fibrinogen, activity of FVII, antithrombin. plasmin inhibitor (PI) and fibrin D-dimer. Significant decreases in PT%, FVII activity and antithrombin as well as an increase in fibrinogen and D-dimer were noticed in ischaemic stroke and in both groups of patients with haemorrhagic stroke. PI levels were significantly lower in subarachnoid haemorrhage patients compared with those in controls and those in both the intracerebral haemorrhage and the ischaemic stroke patients. With the exception of this difference, there were no other differences between ischaemic stroke and the two types of haemorrhagic stroke. This could indicate that haemostatic abnormalities are a consequence of brain damage rather than primary haemostatic activation during thrombosis and/or bleeding in the acute phase of stroke. A decrease in the plasmin inhibitor could suggest excessive fibrinolysis in subarachnoid haemorrhage.

Acute Disease↗
PubMedDate not supplied

Thrombin activatable fibrinolysis inhibitor (TAFI) at the interface between coagulation and fibrinolysis.

The thrombin-catalysed conversion of plasma fibrinogen into fibrin and the development of an insoluble fibrin clot are the final steps of the coagulation cascade during haemostasis. A delicate balance between coagulation and fibrinolysis determines the stability of the fibrin clot. Thrombin Activatable Fibrinolysis Inhibitor (TAFI) plays an important role in this process. TAFI is activated by thrombin and protects the fibrin clot against lysis. The role of TAFI in bleeding and thrombotic disorders is discussed as well as its novel emerging role in wound healing and inflammation.

Blood Coagulation↗
PubMed1997

Coagulation and fibrinolysis changes in normal pregnancy. Increased levels of procoagulants and reduced levels of inhibitors during pregnancy induce a hypercoagulable state, combined with a reactive fibrinolysis.

OBJECTIVE: To establish the physiologic changes in the coagulation and fibrinolytic systems during normal pregnancy and puerperium. STUDY DESIGN: One hundred and seventeen normal pregnant women were investigated in a longitudinal study involving five measurements: blood samples were collected at 10, 20, 30, 36 weeks and on the second day puerperium and were assayed for prothrombin time (PT expressed in INR), activated partial thromboplastin time (PTT), fibrinogen (FBG), antithrombin III activity (AT III), protein C activity (PC), protein S activity (PS), prothrombin fragments 1+2 (F1+2), type 1 plasminogen activator inhibitor activity (PAI) and tissue-plasminogen activator antigen (t-PA). Student t-test, One Way Analysis of Variance (ANOVA) and Bonferroni test were used for statistical analysis. P<0.05 (two tails) was assumed to indicate a significant difference. RESULTS: Fibrinogen concentrations were always increased with respect to controls (P<0.001), while protein S was always decreased, with values averaging 60% of those of controls from the 10th week of pregnancy onwards (P<0.001). Variance analysis showed a statistically significant increase with gestational age for procoagulant factors (INR: P<0.001; FBG: P<0.001), a reduction for anticoagulants (PC: P<0.0001; PS: P<0.0001), and a rise for F1+2 (P<0.0001). With regard to fibrinolysis, there was an increase both for t-PA (P<0.0001) and PAI-1 (P<0.0001) during pregnancy. The t-PA values were always comprised in the normal range. PAI-1 were increased with respect to control values starting from 31st week. The most significant variations in the procoagulants (expressed by PT and FBG) were recorded up to the 20th week (P<0.001); from the 30th week onwards, they remained stable until after the delivery. The same was true for protein S levels (P<0.001), except that the difference between the 10th and the 20th weeks was not statistically significant. The level of F1+2 gradually increased throughout pregnancy (P<0.001), and then fell in the puerperium (P<0.001). CONCLUSIONS: The parameters showing the greatest variation during pregnancy were PT, FBG, PS, F1+2 and PAI-1. The existence of a hypercoagulable state in pregnancy was suggested by the increased levels of F1+2.

Adult↗
PubMed2005

Evolution of thrombin formation and fibrinolysis markers, including thrombin-activatable fibrinolysis inhibitor, during severe meningococcemia.

A 17-year-old girl presented with Neisseria meningitidis sepsis, with evidence of disseminated intravascular coagulation. Substitution therapy with both antithrombin and protein C concentrates was initiated, leading to clinical and biological improvement. Sequential dosages were performed for biological markers including thrombin-activatable fibrinolysis inhibitor (TAFI). Substitution therapy with both antithrombin and protein C concentrates led to a clinical and biological improvement. Biological markers showed a decrease in thrombin generation and in plasminogen activator inhibitor 1 (PAI-1) and a return of TAFI to a normal value. Discontinuation of substitutive treatment was marked by a clinical relapse at 24 h, with thrombin generation and increase in PAI-1, while TAFI remained unchanged. This report shows the evolution of hemostasis markers during septic shock and provides new data concerning the effects of a substitutive therapy.

Adolescent↗
PubMed2004

Thrombin activatable fibrinolysis inhibitor (TAFI) affects fibrinolysis in a plasminogen activator concentration-dependent manner. Study of seven plasminogen activators in an internal clot lysis model.

TAFIa was shown to attenuate fibrinolysis. In our in vitro study, we investigated how the inhibitory effect of TAFIa depended on the type and concentration of the plasminogen activator (PA). We measured PA-mediated lysis times of plasma clots under conditions of maximal TAFI activation by thrombin-thrombo-modulin in the absence and presence of potato carboxypeptidase inhibitor. Seven different PAs were compared comprising both tPA-related (tPA, TNK-tPA, DSPA), bacterial PA-related (staphylokinase and APSAC) and urokinase-related (tcu-PA and k2tu-PA) PAs. The lysis times and the retardation factor were plotted against the PA concentration. The retardation factor plots were bell-shaped. At low PA concentrations, the retardation factor was low, probably due to the limited stability of TAFIa. At intermediate PA concentrations the retardation factor was maximal (3-6 depending on the PA), with TNK-tPA, APSAC and DSPA exhibiting the strongest effect. At high PA concentrations, the retardation factor was again low, possibly due to inactivation of TAFIa by plasmin or to a complete conversion of glu-plasminogen into lys-plasminogen. Using individual plasmas with a reduced plasmin inhibitor activity (plasmin inhibitor Enschede) the bell-shaped curve of the retardation factor shifted towards lower tPA and DSPA concentrations, but the height did not decrease. In conclusion, TAFIa delays the lysis of plasma clots mediated by all the plasminogen activators tested. This delay is dependent on the type and concentration of the plasminogen activator, but not on the fibrin specificity of the plasminogen activator. Furthermore, plasmin inhibitor does not play a significant role in the inhibition of plasma clot lysis by TAFI.

Antifibrinolytic Agents↗
PubMed1986

[Studies on fibrinolysis and ascites accumulation associated with peritonitis carcinomatosa--effects of protease inhibitors (PI) on MM2 ascites tumor growth, ascites accumulation and fibrinolysis].

The effects of protease inhibitors(PI), t-AMCHA, gabexate, aprotinin and heparin on the growth of mouse MM2 ascites tumor (MAT) and on several components of fibrinolysis were studied. The drugs were administered intraperitoneally one time daily for 12 days, one day after the tumor transplant. The volumes of ascites, total packed cell volume (TPCV) and fibrinolytic parameters (FDP, whole plasmin, plasminogen activator (PA)) were measured on the 8, 10 and 12th days of therapy. Fibrinolytic activity was assayed by the lysin sepharose affinity chromatography-radio caseinolytic method. Fibrinolytic activity in the ascites increased during the tumor growth. The ascites accumulation as well as levels of FDP, whole plasmin and PA in the drug treated group were significantly decreased when compared to the control group. In these drug-treated groups, MAT cells agglutinated in the abdominal cavity, but in contrast to this, no agglutination was observed in the control group. It was uncertain whether PI directly inhibited tumor growth. The fact that PI inhibited the ascites accumulation and also decreased fibrinolytic activity suggest the involvement of protease in the neoplastic process and indicates another therapeutic approach to malignant ascites tumors.

Animals↗