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Gene polymorphisms of tissue plasminogen activator and plasminogen activator inhibitor-1 in patients with antiphospholipid antibodies.

OBJECTIVE: Impaired fibrinolytical outcomes may be one of the pathogenic factors for thrombotic events in patients with antiphospholipid antibodies (aPL). We investigated the consequences of the gene polymorphisms of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) in patients positive for aPL. METHODS: Seventy-seven Japanese and 82 British patients with aPL were examined for Alu-repeat insertion (I)/deletion (D) polymorphism of the tPA gene by polymerase chain reaction (PCR), and 4G/5G polymorphism in the PAI-1 promoter gene by site-directed mutagenesis-PCR and restriction fragment length polymorphism analysis. Correlations between these polymorphisms and clinical symptoms of antiphospholipid syndrome (APS) (arterial thrombosis, venous thrombosis, miscarriage) were analyzed. RESULTS: Significant differences in the allele frequencies of these genes did not exist between patients and controls. There was no significant correlation between these gene polymorphisms and clinical symptoms of APS in patients with aPL. CONCLUSION: Polymorphisms of the tPA or PAI-1 genes probably do not significantly influence the risk of anerial thrombosis, venous thrombosis, or pregnancy morbidity in patients with aPL.

Alleles↗

Relationship of tissue plasminogen activator, plasminogen activator inhibitor-1 and fibrinogen with coronary artery disease in South Indian male subjects.

AIM: Prevalence rates of coronary artery disease (CAD) are reported to be very high in Asian Indians. Conventional risk factors do not explain the high rates of CAD among Indians. Recently, several newer risk factors have been reported to be associated with CAD. We measured tissue plasminogen activator (tPA) antigen, plasminogen activator inhibitor-1 (PAI-1) and fibrinogen levels in South Indian diabetic and non-diabetic subjects with and without CAD. METHODS: Four groups of subjects were studied (all males); Group 1 comprised of non-diabetic subjects without CAD (n=50). Non-diabetic subjects with CAD formed group 2 (n=50); group 3 comprised of type 2 diabetic patients without CAD (n=50) and group 4 consisted of type 2 diabetic patients with CAD (n=50). CAD was diagnosed based on coronary angiographic evidence of severe double or triple vessel disease. RESULTS: Both diabetic and non-diabetic patients with CAD had significantly higher levels of tPA, PAI-1 and fibrinogen compared to non-diabetic without CAD (p < 0.05). Patients with CAD were distributed more in the upper tertiles of these risk factors compared to those without CAD. A strong association between tPA and PAI-1 was noted in the Pearson's correlation analysis (p < 0.001). Univariate regression analysis showed tPA (Odds ratio--1.12, p = 0.03), PAI-1 (Odds ratio--1.03, p = 0.008), fibrinogen (Odds ratio--1.01, p < 0.0001), serum cholesterol (Odds ratio--1.008, p = 0.04) and hypertension (Odds ratio--3.7, p = 0.0001) to be associated with CAD. Multiple logistic regression analysis revealed hypertension (Odds ratio--4.6, 95% confidence interval--2.113-9.950, p = 0.0001) and fibrinogen (Odds ratio--1.012, 95% confidence interval--1.007-1.018, p = 0.0001) as risk factors for CAD. CONCLUSION: Our study suggests that prothrombogenic risk factors particularly fibrinogen may be associated with CAD in South Indians.

Analysis of Variance↗

Enhanced benefit from adjuvant chemotherapy in breast cancer patients classified high-risk according to urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (n = 3424).

Risk assessment and prediction of response to treatment are prerequisites for individualized adjuvant therapy decisions in breast cancer. The strong prognostic impact of the two invasion factors urokinase-type plasminogen activator (uPA) and its inhibitor, plasminogen activator inhibitor type 1 (PAI-1), in breast cancer has recently been validated at level-I evidence. This article considers the predictive impact of uPA/PAI-1 on response to adjuvant chemo- and endocrine therapy in 3424 primary breast cancer patients from two different data sets. uPA and PAI-1 antigen levels were measured by ELISA in primary tumor tissue extracts. After a median follow-up of 83 months, uPA/PAI-1 has a significant impact on disease-free survival in Cox multivariate analysis (P < 0.001; hazard ratio, 2.0; 95% confidence interval, 1.8-2.3). Patients with high uPA/PAI-1 levels benefit more strongly from adjuvant chemotherapy than those with low levels. This effect is seen as a significant interaction between chemotherapy and uPA/PAI-1 for the entire collective (P < 0.003; hazard ratio, 0.68; 95% confidence interval, 0.53-0.88) and separately within nodal subgroups. This enhanced benefit in the high uPA/PAI-1 patients occurs over and above the significant impact of both therapies in all patients. We find no corresponding significant interaction between endocrine therapy and uPA/PAI-1; i.e., no significant difference in benefit between patients with high and low uPA/PAI-1. In conclusion, uPA and PAI-1 levels in primary tumor tissue provide clinically relevant information on relapse risk and treatment response that will help to tailor adjuvant therapy concepts in breast cancer, accounting for individual biological tumor characteristics.

Adult↗

[Relationship between plasminogen activator, plasminogen activator inhibitor and Sertoli cells].

Plasminogen activator(PA) and plasminogen activator inhibitor(PAI) are involved in many physiological or pathological events. The Sertoli cells, the important elements within the seminiferous epithelium, are thought to play a key role in spermatogenesis. The Sertoli cells secrete PA and PAI. The levels of them are modulated by hormonal and cell-mediated influences. They play a fundamental role in the maintenance of spermatogenesis, sperm motility and fertilization.

Humans↗

Identification and partial characterization by chemical cross-linking of a binding protein for tissue-type plasminogen activator (t-PA) on rat hepatoma cells. A plasminogen activator inhibitor type 1-independent t-PA receptor.

Plasma tissue-type plasminogen activator (t-PA) is cleared rapidly in vivo by the liver. Previous studies with the human hepatoma cell line HepG2 have identified a clearance system for t-PA modulated by plasminogen activator inhibitor type 1 (PAI-1). In the present study, a rat hepatoma cell line MH1C1 is shown to contain a PAI-1-independent t-PA clearance system. At 4 degrees C, binding of 125I-t-PA to MH1C1 cells was rapid, specific, and saturable. Scatchard analysis of the binding data yielded a mean estimate of 105,000 high affinity binding sites per cell (Kd = 4.1 nM). When the bound ligand was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the majority (about 90%) of the specific binding was in the form of uncomplexed 125I-t-PA. This is in contrast to HepG2 cells in which specific binding was mainly in the form of a sodium dodecyl sulfate-stable 125I-t-PA.PAI-1 complex. When availability of matrix-associated PAI-1 was blocked by preincubation with anti-PAI-1 antibody or removed by elastase treatment, specific 125I-t-PA binding to MH1C1 cells was unaffected, whereas most of the specific 125I-t-PA binding to HepG2 cells was abolished. Furthermore, when the active site of t-PA was inactivated with diisopropyl fluorophosphate, the diisopropyl fluorophosphate-t-PA specifically competed for binding of 125I-t-PA to MH1C1 cells, but failed to block specific 125I-t-PA binding to HepG2 cells. At 37 degrees C, PAI-1-independent t-PA binding to MH1C1 cells was followed by ligand uptake and degradation with kinetics similar to that seen in HepG2 cells. Chemical cross-linking of t-PA to MH1C1 cells revealed a specific t-PA binding protein with a molecular mass of about 500,000 daltons. Ligand-receptor complexes generated by chemical cross-linking were immunoprecipitable by anti-t-PA antibody but not by anti-PAI-1 antibody, further supporting the finding that binding of t-PA to MH1C1 cells is PAI-1-independent.

Animals↗

Behaviour of tissue plasminogen activator, plasminogen activator inhibitor 1 and their complex in various disease states.

Plasma levels of tissue plasminogen activator (t-PA) antigen, plasminogen activator inhibitor 1 (PAI-1) antigen and t-PA/PAI-1 complex were measured in plasmas from 18 healthy subjects and 75 patients with various diseases (28 patients with haematological malignancies, 20 with thrombotic diseases, five with infectious diseases, four with liver diseases, ten with bleeding disorders and eight miscellaneous conditions). In addition, we studied ten patients with bleeding disorders after DDAVP infusion and 18 healthy subjects after venous occlusion. Plasma levels of t-PA antigen, PAI-1 antigen and t-PA/PAI-1 complex were increased in the patients compared with the healthy subjects. t-PA/PAI-1 complex levels correlated well with t-PA antigen levels and molar concentrations of t-PA antigen were similar to those of the t-PA/PAI-1 complex. Venous occlusion induced an increase in both t-PA antigen and PAI-1 antigen and the molar concentration of the t-PA/PAI-1 complex was equivalent to that of t-PA antigen. Following DDAVP infusion, the levels of t-PA antigen and t-PA/PAI-1 complex increased but PAI-1 antigen levels decreased, and the increase of t-PA antigen was greater than that of t-PA/PAI-1 complex. These findings indicate that PAI-1 antigen exceeds t-PA antigen in healthy subjects and in patients with various diseases. We conclude that part of the t-PA/PAI-1 complex is rapidly cleared from the circulation and that free t-PA increases after DDAVP infusion.

Adult↗

The effect of insulin treatment on the balance between tissue plasminogen activator and plasminogen activator inhibitor-1 in type 2 diabetic patients.

Beside hypercoagulation and hyperactivated platelets disturbances of the fibrinolytic system towards hypofibrinolysis have been reported to be associated with both glycemic and lipidemic derangement in diabetic patients. In the present prospective follow-up study the effect of 16 weeks insulin treatment and glycemic regulation on plasma levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1), the main regulators of fibrinolysis, was investigated in 19 type-2 diabetic patients with secondary failure to sulphonylureas. A similar glycemic regulation was obtained in a control group of 10 type 2 diabetic patients with sufficient metabolic response to strict dietary treatment and continuation of sulphonylurea treatment. Compared to 27 healthy subjects levels of tPA and PAI-1 were not significantly increased in type 2 diabetic patients before metabolic intervention. Although a hypofibrinolytic state due to an increase of PAI-1 levels was previously reported in obese hyperinsulinemic patients, no effect of insulin treatment on both tPA- and PAI-1 levels was observed in the present study including patients with only slightly increased body mass index (median 26.0 kg/m2). By correlation analysis PAI-1 levels were significantly related to serum cholesterol (R = 0.52) and glycemic control (glucose R = 0.41) in the whole group of diabetic patients at entry and in both subgroups after 16 weeks of treatment (insulin group: cholesterol R = 0.46, HbA1c R = 0.51; sulphonylurea group: cholesterol R = 0.59, HbA1c R = 0.58). In healthy subjects tPA and PAI-1 was correlated to serum insulin (R = 0.54, R = 0.56) and triglycerides (R = 0.46, R = 0.40).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Tissue plasminogen activator and plasminogen activator inhibitor gene polymorphisms: possible relation to atherosclerosis and its complications].

In the present review the dates about association of genetic variants of a plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) with ischemic heart disease and atherosclerosis of other localization are toted. The singularities of synthesis of PAI-1 and tPA, possible paths of regulation of their activity briefly surveyed. Known polymorphisms of PAI-1 gene and tPA gene, their localization, frequencies in different ethnic groups are circumscribed. In operation the genetic influence of polymorphisms of PAI-1 gene and tPA gene on synthesis and plasma concentration of PAI-1 and tPA, including under an operation of risk factors of atherosclerosis, and as possible clinical consequences of sectional violations is featured. In the review the possible role of polymorphisms of PAI-1 gene and tPA gene in a pathogenesis of atherosclerosis, association with hazard thrombotic complications for different diseases is considered. Many clinical examinations are circumscribed which have confirmed or not confirmed a possible connection of genetic markers with development and current of ischemic heart disease and other vascular diseases. We considered that there are no enough dates to one valued estimation of possible role of polymorphisms of PAI-1 and tPA genes in pathogenesis of atherosclerosis. It is necessary to get new genetic studies in groups of patient with high risk of ischemic heart disease and atherosclerosis.

Arteriosclerosis↗

[Tissue-type plasminogen activator (T-PA) and plasminogen activator inhibitor (PAI-1) in human follicular fluid during gonadotropin-induced ovulation].

OBJECTIVES: Plasminogen activators and their inhibitors have been implicated in the process of fibrinolysis, tissue remodeling, and ovulation. To evaluate the role of t-PA and PAI-1 in human ovulation, we obtained follicular fluid (FF) from preovulatory follicles of patients undergoing IVF-ET. Concentrations tPA and PAI-1 were analyzed in relation to oocyte maturation. Levels of tPA and PAI-1 obtained after COH were compared to the tPA and PAI-1 concentrations in the follicular fluid of healthy, fertile women. MATERIALS AND METHODS: FF was collected from 66 infertile patients undergoing ovulation induction using either short or long protocol. FF was obtained 36 hours after hCG (Pregnyl) administration. The control group consisted of 16 fertile women with unstimulated cycles. Concentrations of t-PA Ag and PAI-1 Ag were measured using Elisa kits (Bioopol). RESULTS: The average follicular fluid tPA concentration of patients undergoing IVF-ET treatment was significantly lower (0.039 vs 0.117 ng/mg protein; p < 0.0005), whereas PAI-1 significantly higher (3.261 vs 0.135 ng/mg; p < 0.0001) compared to the control group. Concentrations of tissue-type plasminogen activator in FF of patients with 5 or more mature oocyte were significantly lower (0.017 vs 0.056 ng/mg) and levels of PAI-1 higher (3.49 vs 2.9 ng/mg) in comparison to cases involving < 5 oocytes. CONCLUSIONS: 1. Concentration of tPA in the follicular fluid is significantly lower whereas PAI-1 level significantly higher in patients undergoing COH. 2. Follicular fluid tPA and PAI-1 concentrations may be a crucial factors reflecting oocyte maturity.

Adult↗

Plasminogen activator inhibitor-1 binds to fibrin and inhibits tissue-type plasminogen activator-mediated fibrin dissolution.

Plasminogen activator inhibitor-1 (PAI-1) accumulates within thrombi and forming whole blood clots. To explore this phenomenon at the molecular level, PAI-1 binding to fibrin was examined. The experiments were performed by adding 125I-PAI-1, which retains its complete tissue-type plasminogen (t-PA) inhibitory activity, to fibrin matrices formed in 2-cm2 tissue culture wells. Guanidine HCl-activated PAI-1 binding was reversible and was inhibited in the presence of excess, unlabeled PAI-1. Activated 125I-PAI-1 recognized 2 sites on fibrin: a very small number of high affinity sites (Kd less than 1 nM) and principally a large number of low affinity sites with an approximate Kd of 3.8 microM. Latent PAI-1 bound to fibrin at a site indistinguishable from the lower affinity site recognized by activated PAI-1. Fibrin, pretreated with activated PAI-1, was protected from t-PA-mediated plasmin degradation in a PAI-1 dose-responsive manner (IC50 = 12.3 nM). Clot protection correlated with partial occupancy of the low affinity PAI-1 binding site on fibrin and was due to the formation of sodium dodecyl sulfate-stable, PAI-1.t-PA complexes. Latent PAI-1 (27 nM) did not protect the fibrin from dissolution. The localization of PAI-1 to a thrombus by virtue of its fibrin binding potential could result in significant protection of the thrombus from the degradative effects of the fibrinolytic system.

Binding, Competitive↗

[The plasma levels of transforming growth factor beta1 and the protein expressions of alpha-SMA, urokinase plasminogen activator and plasminogen activator inhibitor-1 in liver of patients with different grades of hepatic fibrosis].

OBJECTIVE: To measure the plasma levels of transforming growth factor beta1 (TGFbeta1), the protein expression of alpha-SMA in hepatic stellate cells and urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1), and study on the relationships between the plasma levels of TGFbeta1, the protein expression and the serum hyaluronic acid (HA) in patients with different grades of hepatic fibrosis. METHODS: Thirty seven cases with hepatic fibrosis of different grades were classified according to HE and VG staining categories from 0 to 4, in which there were 8 cases in grade 1, 9 cases in grade 2, 7 cases in grade 3, 13 cases in grade 4. The plasma levels of TGFbeta1 and the serum levels of HA were detected by ELISA. The protein expressions of a-SMA, uPA and PAI-1 in fibrotic liver tissue were observed by immunohistochemistry. RESULTS: With the progression of hepatic fibrosis, the plasma levels of TGFbeta1 and the protein expression of a-SMA, uPA and PAI-1 in fibrotic liver tissue were increased. In grade 3 and 4, the plasma levels of TGFbeta and the protein expression of a-SMA and PAI-1 in fibrotic liver tissue were significantly increased, but the protein expression of uPA in cirrhosis liver tissue did not increased. CONCLUSION: TGFbeta1, a-SMA, uPA and PAI-1 play an important role in the progression of hepatic fibrosis. Inhibiting the early activation of latent TGFbeta1 or increasing uPA and inhibiting PAI-1 over express may contribute to matrix degradation and retard the progression of hepatic fibrosis.

Actins↗

[Changes in tissue plasminogen activator and plasminogen activator inhibitor during administration of nitroglycerine into internal thoracic artery in dogs with acute myocardial ischemia].

OBJECTIVE: To study the changes in tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in a model of acute myocardial infarction reproduced in the dog with administration of nitroglycerin into internal thoracic artery under pressure. METHODS: Sixty healthy cross-breed dogs were randomly divided into experimental and control group with 30 dogs in each group. The animal model of acute myocardial ischemia was reproduced by ligating the left anterior descending coronary artery. Internal thoracic artery in the experimental group was ligated, and a tube was introduced into the proximal end. Nitroglycerine was infused under pressure into the internal thoracic artery in experimental group. The drug was given intravenously in control group. t-PA and PAI were measured before anterior coronary artery ligation and at 0.5, 2 and 6 hours after coronary artery ligation. RESULTS: The t-PA levels in two groups were increased at 0.5 hour after coronary artery ligation, and gradually declined in control group, while no obvious change was found in experimental group. There was significant difference between experimental group and control group at 6 hours after coronary artery ligation(P<0.05). PAI levels were increased after coronary artery ligation, peaking at 6 and 2 hours after coronary artery ligation in both groups. Significant difference in PAI level was observed between two groups at 6 hours after coronary artery ligation(P<0.05). CONCLUSION: Introduction of nitroglycerine through internal thoracic artery under pressure is effective to accelerate release of t-PA from the endothelium while inhibit secretion of PAI, therefore it is useful to modulate the balance of fibrinolysis.

Animals↗

[Changes of platelet endothelial cell adhesion molecule-1, tissue type plasminogen activator and plasminogen activator inhibitor-1 expression in the lung tissue of neonatal rats after intraperitoneal injection with lipopolysaccharide].

OBJECTIVE: To further explore the pathogenesis of neonatal acute lung injury and neonatal pulmonary hemorrhage by establishing the animal model of neonatal acute lung injury (ALI) and by investigating the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1), tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) in ALI. METHODS: Totally 88 neonatal rats which were divided into 8 groups randomly including one normal saline control group and 30 min, 1 h, 2 h, 4 h, 8 h, 16 h and 24 h post injection groups. The changes of lung pathology in newborn rats were observed at different time after LPS was injected intraperitoneally. The changes of PECAM-1 protein, t-PA and PAI-1 mRNA expression were measured by immunohistochemistry and RT-PCR. RESULTS: The expression of PECAM-1 protein and mRNA was decreased and the lowest level was reached at 8 h and 16 h post injection, respectively. The average values were 95.1 +/- 9.76 and 0.861 +/- 0.016, respectively, which were significantly lower than those in the control group (129.5 +/- 6.15, 1.192 +/- 0.035, P < 0.01). The expression of t-PA and PAI-1 mRNA was increased after LPS was injected. The highest level of t-PA mRNA expression was observed at 2 h after injection. The average value was 1.195 +/- 0.036, which was significantly higher than that in the control group (0.781 +/- 0.017, P < 0.01). The highest level of PAI-1 mRNA expression was observed at 2 h, 4 h and 8 h post injection. The average values were 1.178 +/- 0.069, 1.153 +/- 0.036 and 1.176 +/- 0.044, respectively, which was significantly higher than those of the control group (0.681 +/- 0.019, P < 0.01). CONCLUSIONS: The expression of PECAM-1 protein and mRNA was decreased after LPS injection, suggesting the disruption of the tissue protective mechanism; the expression of t-PA and PAI-1 mRNA was increased, indicating the presence of a hypercoagulability state. At the same time, the expression of t-PA mRNA was increased which caused the extra-cellular matrix degradation at the early phase after LPS injection. These three phenomena might be the contributory factors to pulmonary hemorrhage.

Acute Lung Injury↗

[Expression of plasminogen activator inhibitor-1 and tissue plasminogen activator in the kidney of KKAy mice with type 2 diabetes].

OBJECTIVE: To study the role of plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) in the accumulation of extracellular matrix (ECM) in the kidney of KKAy mice with type 2 diabetes. METHODS: KKAy mice, a type 2 diabetic animal model, and C57BL-J mice were sacrificed at 16, 20, and 24 weeks of age, respectively. The local expression of renal laminin was analyzed with immunohistochemistry. Chromogenic substance was used to show the activity of PAI-1. The mRNA expression of tPA was determined by RT-PCR. The mRNA expression of PAI-1 was measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Laminnin expression was significantly increased in all age groups of KKAy mice. The tPA mRNA was significantly lower than that in C57BL mice, especially at the age of 16w (only 47%). Otherwise the PAI-1 mRNA expression was remarkably up-regulated than that in C57BL mice. CONCLUSION: In type 2 diabetes KKAy mice, the accumulation of ECM may be associated with the abnormal expression of PAI-1/tPA mRNA.

Animals↗

Effect of plasminogen activator inhibitor-1 on tissue-type plasminogen activator-induced fibrinolysis.

The effect of fibrin on the interaction of human recombinant single-chain tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) was studied in normal rabbit plasma and in plasma with high levels of native PAI-1. t-PA was added to diluted plasma containing calcium (10 mM) and 125I-fibrinogen at 37 degrees C. Clotting was initiated with human thrombin, and lysis was monitored both turbidimetrically and by release of 125I-fibrin degradation products (fdp). The activity of t-PA (50 IU/ml) was rapidly reduced to 15% of the initial value in plasma containing PAI-1 (23 AU/ml). When thrombin and t-PA were added simultaneously to the plasma, more than 70% of the activity was retained through incorporation of t-PA into the fibrin clot. t-PA-induced fibrinolysis in PAI-1 enriched plasma was further delayed when the temperature was reduced from 37 to 25 degrees C. Turbidimetric and 125I-fdp release data provided complementary information. The former technique traced fiber dissolution, while the latter reflected network integrity. These results indicate that t-PA-induced fibrinolysis in PAI-1 enriched plasma is modulated by the presence of fibrin and by temperature.

Animals↗

[Effect of vacuum-assisted closure on the expression of urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor in acute and chronic wounds healing].

OBJECTIVE: To study the effect of vacuum-assisted closure (V.A.C) on the expression of Urokinase-type plasminogen activator (uPA) and Urokinase-type plasminogen activator receptor(uPAR) protein in margin tissue of pigs with acute wounds and patients with chronic wounds. METHODS: Acute wounds were created on the two side of five male pigs' back, the experiment wounds on one side received V. A. C treatment and the control side received traditional treatment. Punch biopsies were taken from margin tissue of the wounds in 0, 1, 3, 6, 9, 12, 18, 25 days after the V.A.C treatment. The uPA and uPAR positive cells were stained with immunohistochemical technique . Six human chronic wounds were also treated with the V. A. C treatment, and the samples of extravasate from those wounds were collected in 0, 1, 3, 5, 7 days after the treatment, and the levels of uPA and uPAR expression were examined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The expression of uPA and uPAR protein in margin tissues of pigs with acute wounds increased and peaked in 3 days after the treatment with V. A. C, then it presented rapidly downtrend, but the expression and staining in the experiment group were obviously higher than that of the control group. In the six chronic wounds, the high level expression of uPA and uPAR protein was decreased after the treatment with V. A. C. CONCLUSION: The V. A. C may increase the expression of uPA and uPAR protein in acute wound keratinocytes and decrease the high expression of uPA and uPAR in chronic wounds.

Adult↗

Synthesis and secretion of plasminogen activator inhibitor 1 by human endothelial cells in vitro. Effect of active site mutagenized tissue-type plasminogen activator.

The effects of recombinant tissue-type plasminogen activator (rt-PA) and of an inactive mutant of rt-PA, obtained by mutagenesis of the active site Ser478 to Ala (rt-PA-Ala478), on the synthesis and secretion of plasminogen activator inhibitor-1 (PAI-1) by human umbilical vein endothelial cells (HUVEC) in culture were studied. Under base-line conditions, PAI-1 antigen secretion was 4.3 +/- 1.0 micrograms (mean +/- S.D., n = 8) per 10(6) cells in 24 h. This PAI-1 had a low specific activity (6,000 +/- 1,600 units/mg) and Mr of 50,000, which was not altered by addition of rt-PA. In HUVEC cultured with 2 micrograms/ml rt-PA-Ala478, PAI-1 antigen secretion was 2.1 +/- 0.8 micrograms (n = 5) per 10(6) cells in 24 h with a specific activity of 120,000 +/- 42,000 units/mg and Mr of 50,000. Addition of rt-PA to this conditioned medium resulted in generation of three main components: 16% migrated as an Mr 106,000 rt-PA.PAI-1 complex, 16% as an Mr 81,000 degraded rt-PA.PAI-1 complex and the remainder as an Mr 45,000 degradation product of PAI-1. HUVEC cultured with 2 micrograms/ml rt-PA secreted 3.9 +/- 0.6 micrograms (n = 8) PAI-1 antigen per 10(6) cells within 24 h, of which 20-50% occurred as intact or degraded complexes with t-PA (Mr 106,000 and 81,000) and the rest as an inactive Mr 45,000 degradation product of PAI-1. PAI-1 mRNA levels, determined by Northern blot analysis and expressed relative to beta-actin mRNA levels, were very similar for HUVEC cultured in the absence or the presence of rt-PA or rt-PA-Ala478. It is concluded that PAI-1 is secreted by HUVEC in culture in fully active form which spontaneously inactivates. PAI-1 can be stabilized by addition of rt-PA-Ala478 to the culture medium, resulting in a 20-fold increase in specific activity. Interaction of rt-PA with active PAI-1 produces both t-PA.PAI-1 complex and an inactive degradation product of PAI-1.

Antigens↗

Correlation between baseline plasminogen activator inhibitor levels and clinical outcome during therapy with tissue plasminogen activator for acute myocardial infarction.

Baseline plasminogen activator inhibitor (PAI) levels were examined for their influence on the responses to thrombolysis with recombinant tissue plasminogen activator (rt-PA) administered for acute myocardial infarction during the Thrombolysis and Myocardial Infarction (TAMI)-I study. Baseline PAI activity was 19 +/- 21 IU/ml (normal less than 5 IU/ml) and baseline PAI-1 antigen 54 +/- 53 ng/ml (normal 27 +/- 16 ng/ml), confirming previous findings of elevated PAI levels during acute myocardial infarction. Among clinical outcomes, lower PAI-1 antigen levels correlated weakly with greater patency at the 90 min angiogram. Thus, high baseline plasma PAI-1 levels may be detrimental to reperfusion with t-PA. There was no correlation with other major in-hospital clinical outcomes including reocclusion at the 7-10 day angiogram, survival to discharge, or bleeding. During the follow up period of 2.0 +/- 0.4 years, no relationship between baseline PAI levels and post-discharge reinfarction was observed.

Angioplasty, Balloon, Coronary↗