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Results for “alpha-2-Antiplasmin”

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At least 19 recordsLinked to original sources

Proteomic Mediators of Chronic Obstructive Pulmonary Disease Phenotypes and Coronary Artery Calcification Burden in Ever Smokers.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) increases cardiovascular disease risk. Coronary artery calcification (CAC) predicts cardiovascular events and mortality in COPD. We hypothesized that plasma proteins linked to pulmonary phenotypes mediate CAC burden. METHODS: Pulmonary function, emphysema, airway wall thickening, Agatston CAC scores (inverse normal transformed), and relative abundance of 1305 plasma proteins (log-transformed) were assessed in 989 Phase 1 COPDGene (Genetic Epidemiology of COPD) participants. Proteins associated with both pulmonary phenotypes (FEV1[forced expiratory volume in 1 second]%predicted, FVC [forced vital capacity], FEV1/FVC, emphysema, airway wall thickness, wall area percentage) and CAC (false discovery rate P≤0.20) were evaluated using multivariable mediation. Model adjustments included sex, age, race, body mass index, smoking, comorbidities, and medications. Adjustment for pulmonary artery-to-aortic diameter ratio-a marker of pulmonary vascular pressure-was also explored. The95% bootstrap CIs that excluded zero were considered significant. RESULTS: FEV1%predicted (P=0.026) and FEV1/FVC (P=0.010) were associated with CAC. After adjusting for FEV1, visual emphysema, and visual airway wall thickening remained associated with CAC. Five proteins (TSP2 [thrombospondin-2], renin, MMP-7 [matrix metalloproteinase-7], ERBB1 [epidermal growth factor receptor], MIC-1 [macrophage inhibitory cytokine-1]) mediated the FEV1%predicted and CAC association. All except MIC-1 mediated FEV1/FVC and CAC. All except renin mediated quantitative airway wall thickness or wall area percentage and CAC. Additionally, α2-antiplasmin (alpha-2 antiplasmin) mediated airway wall thickness and CAC. ERBB1 mediated visual paraseptal emphysema and CAC. Pulmonary artery-to-aortic diameter ratio adjustment reduced or eliminated some mediation effects. ERBB1 remained an independent mediator across multiple phenotypes. CONCLUSIONS: Six plasma proteins mediated associations between COPD phenotypes and CAC burden. These effects were partially influenced by pulmonary artery-to-aortic diameter ratio A, suggesting shared molecular pathways linking lung dysfunction to cardiovascular risk in COPD.

Humans↗

Inhibitors of fibrinolysis in diabetic children, mothers, and their newborn.

Late diabetic complications are often related to vascular changes and formation of thrombi in the altered vasculature. Contributing factors to thrombosis susceptibility of diabetic patients include changes in clotting factors, platelets, and inhibition of fibrinolysis. We have measured various fibrinolytic inhibitors in the blood of diabetic children, diabetic pregnant women and their offspring, and healthy controls. Inhibitors studied included 1) fast (immediate) antiplasmin, 2) slow (progressive) antiplasmin, 3) alpha-2-macroglobulin, and 4) alpha-1-antitrypsin. It appears from our study that high fast-antiplasmin levels, and low or missing slow-antiplasmin levels are characteristic of diabetic patients and of newborn of diabetic mothers. The reason for high fast-antiplasmin levels is not clear: Levels are not connected with the age of the patient or duration of diabetes, and are not elevated in response to a fibrinolytic process (fibrin decomposition products could not be shown to be present in the serum of diabetic children). Alpha-2-macroglobulin was significantly higher and alpha-1-antitrypsin significantly lower in diabetic women than in controls. In the other groups of patients studied differences in these inhibitors from the appropriate control groups were not statistically significant.

Adolescent↗

The fibrinolysin system and its relationship to disease in the newborn.

The fibrinolysin system is incomplete in newborn infants. Lack of serum plasminogen in premature newborn has an important role in the pathophysiology of the respiratory distress syndrome since alveolar fibrin deposits cannot be eliminated. Urokinase activated human plasmin has increased the survival rate of infants with respiratory distress syndrome. Plasminogen given I.V. at birth has reduced the incidence and the severity of respiratory distress syndrome, in a randomized double-blind study of 500 premature infants. Death in the plasminogen recipient group occurred only among infants born to mothers with bleeding complications of pregnancy. Plasmin inhibitors measured with a functional assay were the highest in this group of infants, serum plasminogen was the lowest; when activator and purified human plasminogen were added to the serum, fibrinolytic activity was elicited in excess of the plasminogen added. It is suggested that plasminogen and/or plasmin inhibitors may be abnormal fetal variants in infants born to mothers with bleeding complications.

Clinical Trials as Topic↗

Kinetics of the reactions between streptokinase, plasmin and alpha 2-antiplasmin.

Streptokinase reacts very rapidly with human plasmin (rate constant 5.4 S 10(7) M-1 s-1) forming a 1:1 stoichiometric complex which has a dissociation constant of 5 X 10(-11) M. This plasmin-streptokinase complex is 10(5) times less reactive towards alpha 2-antiplasmin than plasmin, the inhibition rate constant being 1.4 X 10(2) M-1 s-1. The loss of reactivity of the streptokinase-plasmin complex towards alpha 2-antiplasmin is independent of the lysine binding sites in plasmin since low-Mr plasmin, which lacks these sites, and plasmin in which the sites have been blocked by 6-aminohexanoic acid, are both equally unreactive towards alpha 2-antiplasmin on reaction with streptokinase. The plasmin-streptokinase complex binds to Sepharose-lysine and Sepharose-fibrin monomer in the same fashion as free plasmin, showing that the lysine binding sites are fully exposed in the complex. Bovine plasmin is rapidly inhibited by human alpha 2-antiplasmin (k1 = 1.6 X 10(6) M-1 s-1) and similarly loses reactivity towards the inhibitor on complex formation with streptokinase (50% binding at 0.4 microM streptokinase).

Binding, Competitive↗

Changes in antiplasmin and plasmin activities during extreme hemodilution and open heart surgery in dogs.

The effects of extreme hemodilution and open heart surgery on antiplasmin and plasmin activities were investigated in dogs. Assays for plasmin and antiplasmin activities were performed with a chromogenic peptide substrate for plasmin. After hemodilution and during cardiopulmonary bypass (CPB), plasmin activity on the substrate was observed and levels of both "fast-reacting" and "total" antiplasmins fell. The plasmin activity was shown to be due to the formation of alpha2-macroglobulin-plasmin complex which exhibited amidolytic activity on the chromogenic substrate. The falls in antiplasmin activity together with the appearance of the alpha2-macroglobulin-plasmin complex revealed that activation of the fibrinolytic system had occurred. After the operation and following reinfusion of autologous blood, decreased plasmin and increased antiplasmin activities were observed. On the first and sixth days following the operation plasmin activities were still slightly higher than pre-operation values, whilst antiplasmin activities were normal.

Animals↗

Peripheral and gastric fibrinolysis in patients with gastric carcinoma.

The fibrinolytic system was studied in blood-samples from gastric and peripheral veins of patients with gastric carcinoma. There was a slight decrease in plasma-euglobulin fibrinolytic activity, a rise of plasma-fibrinogen level and antithrombin VI activity, and a decrease in antiplasmin activity. The changes observed are more marked in blood-samples from gastric veins. Some therapeutical implications and the role of fibrinolytic agents in malignant diseases are briefly discussed.

Fibrin Fibrinogen Degradation Products↗

Studies of fibrinolytic activity of uremic and longterm hemodialytic patients with special reference to fibrinolytic inhibitor.

Fibrinolytic activities on cases with chronic renal failure, 13 cases at pre and post introduction of hemodialysis and 40 cases at pre and post hemodialysis of maintenance hemodialysis with 38 normal controls were investigated. The plasminogen activator of untreated chronic renal failure was lower than controls, yet increased with the introduction of hemodialysis. On the other hand the antiplasmin was lowered with the introduction. In cases with maintenance hemodialysis, the plasminogen activator was lower than controls, but was elevated with hemodialysis. The level of antiactivator was higher in uremia of either pre or post hemodialysis than controls. The levels of alpha 2-macroglobulin and alpha 1-antitrypsin were reduced at prehemodialysis state comparing to controls, and yet, increased with hemodialysis, respectively. The low molecular weight antiplasmin and antiactivator, molecular weight below 30,000 were separated with Sephadex G-50 gel filtration of plasma. The low molecular weight fibrinolysis inhibitors of plasma with untreated uremia were elevated comparing to controls, but decreased with the hemodialysis. The removable fibrinolytic inhibitors were indicated, however, the ratio of the low molecular weight fibrinolytic inhibitors to the total fibrinolytic inhibitors were little.

Adolescent↗

Activation of coagulation and fibrinolysis following OKT3 administration to renal transplant recipients: association with distinct mediators.

Treatment with OKT3 induces cytokine release and activates the complement system. Since both phenomena may affect coagulation and fibrinolysis we studied these systems in 8 renal transplant recipients during OKT3 treatment. In 8 of 9 patients a similar pattern was observed: plasma thrombin-antithrombin-III-complex, tissue-type plasminogen-activator and plasmin-alpha 2-antiplasmin-complex levels were increased as compared to pretreatment levels (p less than 0.05) at 15 min after the first OKT3 dose and reached peak values at 1 h. No significant changes were observed upon subsequent OKT3 administrations or in a control group of 8 patients. In one patient upon the first OKT3 administration only complement activation, and no cytokine release was observed, whereas plasma thrombin-antithrombin-III-complex, tissue-type plasminogen-activator and plasmin-alpha 2-antiplasmin-complex levels increased only at 15 min. In conclusion, we demonstrate a biphasic activation of coagulation and fibrinolysis upon the first OKT3 dose; the initial phase seems to be associated with complement activation, the later phase with cytokine release.

Adult↗

Platelet factor XIII increases the fibrinolytic resistance of platelet-rich clots by accelerating the crosslinking of alpha 2-antiplasmin to fibrin.

Platelet clots resist fibrinolysis by plasminogen activators. We hypothesized that platelet factor XIII may enhance the fibrinolytic resistance of platelet-rich clots by catalyzing the crosslinking of alpha 2-antiplasmin (alpha 2AP) to fibrin. Analysis of plasma clot structure by polyacrylamide gel electrophoresis and immunoblotting revealed accelerated alpha 2AP-fibrin crosslinking in platelet-rich compared with platelet-depleted plasma clots. A similar study of clots formed with purified fibrinogen (depleted of factor XIII activity), isolated platelets, and specific factor XIII inhibitors indicated that this accelerated crosslinking was due to the catalytic activity of platelet factor XIII. Moreover, when washed platelets were aggregated by thrombin, there was evidence of platelet factor XIII-mediated crosslinking between platelet alpha 2AP and platelet fibrin(ogen). Specific inhibition (by a monoclonal antibody) of the alpha 2AP associated with washed platelet aggregates accelerated the fibrinolysis of the platelet aggregate. Thus in platelet-rich plasma clots, and in thrombin-induced platelet aggregates, platelet factor XIII actively formed alpha 2AP-fibrin crosslinks, which appeared to enhance the resistance of platelet-rich clots to fibrinolysis.

Blood Coagulation Factors↗