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Biomedical subjects

A Rydzewski

Publications and source records attributed to A Rydzewski.

At least 19 recordsLinked to original sources
PubMed1992

Tissue plasminogen activator, plasminogen activator inhibitor, and other parameters of fibrinolysis in the early stages of taurocholate acute pancreatitis in rats.

It is well known that fibrinolytic activity in the early stages of acute experimental pancreatitis (AEP) as assessed by euglobulin lysis time (ELT) is depressed. The aim of this study was to evaluate changes in the fibrinolytic system in the early stages of taurocholate AEP in rats. Tissue plasminogen activator (t-PA) activity, plasminogen activator inhibitor 1 (PAI-1) activity, plasminogen, alpha 1 proteinase inhibitor (alpha 1 PI), alpha 2 antiplasmin (alpha 2 AP), antithrombin III (AT III), fibrinogen, and ELT were measured 0.5, 1, 3, and 6 h after the induction of taurocholate AEP in rats, as well as in sham-operated animals and the control group, which was not submitted to any operation. T-PA activity decreased significantly after 3 and 6 h of AEP; PAI activity had a time course reverse to t-PA and was parallel to alpha 1 PI activity. ELT was slightly prolonged after 0.5, 1, and 3 h, whereas alpha 2 AP activity and plasminogen levels increased significantly; AT III activity was increased after 1 h in comparison to control group. Sham operation caused nonsignificant changes in fibrinolysis. Increase of PAI activity and decrease of t-PA could be a reasonable explanation for inhibited plasma euglobulin fibrinolytic activity noted in the early period of AEP.

Acute Disease↗
PubMed1991

Plasminogen activator inhibitor activity as a possible indicator of disease activity in rest angina with angiographically insignificant coronary artery stenosis.

To assess the role of fibrinolytic system, 19 patients with rest angina and insignificant coronary artery stenosis and 23 controls performed symptom-limited multistage exercise. Vasospasm was angiographically demonstrated in 12 patients. Pre- and peak exercise blood samples from each patient were assayed to determine the fibrinolytic components. The patients displayed significantly increased PAI activity both under the basal conditions (p less than 0.01) and at peak exercise (p less than 0.01) as compared with the controls. However, the values of other fibrinolytic components, such as t-PA antigen, t-PA/PAI-1 complex and free PAI-1 antigen, in the controls and patients were similar. Nineteen patients were divided into two groups according to PAI activity levels under basal conditions. Nine patients displayed high PAI activity (more than the mean + 1 SD of the control value) under the basal conditions. When compared to the remaining 10 patients, the high PAI activity group had both a significantly short time interval from the last attack to the time of getting the blood sample (p less than 0.05), and a worse short-term prognosis (p less than 0.05). Thus, the level of PAI activity under basal conditions reflected the extent of disease activity, suggesting that PAI activity may be a useful clinical indicator of the severity of rest angina in patients without significant coronary stenosis.

Adult↗
PubMed1990

Relationships between euglobulin clot lysis time and the plasma levels of tissue plasminogen activator and plasminogen activator inhibitor 1.

The relationships between tissue plasminogen activator (tPA), its fast acting inhibitor (PAI-1) and euglobulin clot lysis time (ELT) were investigated with healthy volunteers' plasma. Turbidimetric clot lysis assay by the microtiter plate reader was utilized for ELT with a slight modification. Both tPA and PAI-1 showed the significant correlation with ELT. tPA had a significantly positive, not negative, correlation with ELT (R = 0.387, p less than 0.001). Higher correlation coefficients (R = 0.580, p less than 0.001 and R = 0.599, p less than 0.001) were obtained between ELT and total PAI-1 or free PAI-1 than tPA or tPA-PAI-1 complex (R = 0.427, p less than 0.001). The positive correlation was also obtained between tPA and PAI-1. These data suggest that PAI-1 is a highly important factor for ELT, especially, the amounts of free PAI-1 being the key factor to determine the ELT, which can represent the potential activity of the fibrinolytic system.

Adult↗
PubMed1990

Fluctuations of euglobulin lysis time, tissue plasminogen activator, and free and total plasminogen activator inhibitor levels in plasma in daytime.

Blood was taken from healthy 15 males and 10 females at 9:30 h, 10:00 h and 12:30 h. The euglobulin fraction was prepared and clotted by the addition of human thrombin. The clot lysis time shortened significantly from 9:30 h to 10:00 h (p less than 0.01) and further to 12:30 h (p less than 0.01). Plasma levels of tissue plasminogen activator (t-PA) antigens did not change from 9:30 h to 10:00 h, but slightly and significantly to 12:30 h (p less than 0.01). Plasma levels of free plasminogen activator inhibitor-1 (PAI-1) and complex of t-PA-PAI-1 decreased from 9:30 h to 10:00 h (p less than 0.02) and to 12:30 h (p less than 0.01). Plasma levels of total PAI-1 (free plus complex) decreased from 9:30 h to 10:00 h (p less than 0.01) and to 12:30 h (p less than 0.01). These results suggest that a major factor contributing to the enhanced fibrinolytic activity of the euglobulin fraction may be a level of PAI-1 (free and total).

Adult↗
PubMed1990

Clinical significance of plasminogen activator inhibitor activity in patients with exercise-induced ischemia.

To assess the fibrinolytic system in patients with exercise-induced ischemia and its relation to ischemia and severity of coronary artery disease (CAD), 47 patients with CAD confirmed by results of coronary angiography underwent symptom-limited multistage exercise thallium-201 emission computed tomography. All patients with CAD had exercise-induced ischemia as assessed from thallium-201 images. Pre- and peak exercise blood samples from each patient and preexercise blood samples from control subjects were assayed for several fibrinolytic components and were also assayed for plasma adrenaline. The extent of ischemia was defined as delta visual uptake score (total visual uptake score in delayed images minus total visual uptake score in initial images) and the severity of CAD as the number of diseased vessels. In the basal condition, plasminogen activator inhibitor (PAI) activity was significantly higher in patients with exercise-induced ischemia as compared to control subjects (p less than 0.01), although there were no significant differences in other fibrinolytic variables between the two groups. Moreover, PAI activity in the basal condition displayed a significantly positive correlation with the extent of ischemia (r = 0.47, p less than 0.01). Patients with exercise-induced ischemia were divided into two groups (24 with single-vessel disease and 23 with multivessel disease). There were no significant differences in coronary risk factors, hemodynamics, or plasma adrenaline levels during exercise between single-vessel and multivessel disease except that delta visual uptake score was significantly higher in multivessel disease (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Changes in plasminogen activator inhibitor 1 and tissue-type plasminogen activator during exercise in patients with coronary artery disease.

As depressed fibrinolysis is implicated in the pathogenesis of coronary artery disease, we have studied the activation of fibrinolysis during maximal, symptom-limited exercise in a group of 68 men. After exercise they were divided, according to their coronary angiography and exercise 201Tl emission computed tomography results, into three groups. Group 1: persons with normal exercise 201Tl emission computed tomography results and no underlying diseases who served as controls; group 2: patients with coronary artery disease without exercise-induced myocardial ischemia, and group 3: patients with coronary artery disease with transient, exercise-induced myocardial ischemia. Before and at peak exercise we measured the plasminogen activator activity (PAA) in the euglobulin fraction of plasma by an amidolytic method and the concentrations of tissue plasminogen activator (t-PA), activator-inhibitor complex - plasminogen activator inhibitor 1 (PAI-1) complexed with t-PA - and total PAI-1 by enzyme immunoassay. The concentration of free PAI-1 in plasma was calculated by subtraction of the concentration of activator-inhibitor complex from that of total PAI-1. Under basal conditions, group 3 had significantly higher free and total PAI-1 levels than group 1. There were no statistically significant differences between the three groups in PAA, t-PA, and activator-inhibitor complex levels. At peak exercise, group 1 showed the highest release of t-PA accompanied with highest increases in PAA as well as in activator-inhibitor complex, the proportion of released t-PA antigen not bound to PAI-1 being highest in group 1. Free PAI-1 decreased significantly, but there were no differences between individual groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Stimulation of plasmin catalyzed conversion of single-chain to two-chain urokinase-type plasminogen activator by sulfated polysaccharides.

Influence of heparin, chondroitin sulfate C and dextran sulfate (MW 3,500 and 7,000) on plasmin catalyzed conversion of single-chain (scu-PA) to two-chain (u-PA) urokinase-type plasminogen activator and generation of plasmin in mixtures of scu-PA and Glu-plasminogen (Glu-plg) was investigated. Conversion of scu-PA to u-PA catalyzed by plasmin was enhanced by chondroitin sulfate C and heparin, maximally by 10-fold and 3-fold, respectively. Sulfated polysaccharides potentiated generation of plasmin in mixtures of Glu-plg and scu-PA, as well as enhanced plasminogenolytic activity of u-PA. The possible role of these interactions is discussed.

Catalysis↗
PubMed1989

Absence of synergism between tissue-type plasminogen activator and urokinase on plasminogen activation rate in plasma.

Effects of tissue-type plasminogen activator (t-PA), urokinase (u-PA) and their combinations on plasminogen activation rate (PAR) in plasma, in vitro were investigated. T-PA and u-PA over concentrations range of 10 U/ml to 50 U/ml induced a linear, concentration dependent increase in PAR. Combinations of t-PA and u-PA in ratios of 3/1, 1/1 and 1/3 induced additive but not synergistic effect in the activation of plasminogen. We conclude, therefore, that t-PA and u-PA do not act synergistically in the activation of plasminogen in plasma in vitro.

Chromogenic Compounds↗
PubMed1989

The role of the fibrinolytic system in acute myocardial infarction after a normal exercise test.

A 67-year-old man had an acute myocardial infarction with thrombosis in the left anterior descending artery shortly after normal exercise. We were able to measure the fibrinolytic components in this patient just prior to his developing acute myocardial infarction as well as during convalescence. In this case, marked increase in total plasminogen activator inhibitor-1 (PAI-1) antigen, mainly due to free PAI-1 antigen, was observed in basal conditions before the onset of acute myocardial infarction. On the appearance of ischaemia, plasminogen activator activity was suppressed, probably due to decreased tissue plasminogen activator antigen release and increased PAI activity, compared with that during convalescence. This suggests that some patients with coronary artery disease who have a high level of free PAI-1 antigen in basal conditions may have a strong tendency to develop acute myocardial infarction, due to further impaired fibrinolysis on the induction of ischaemia.

Acute Disease↗
PubMed1986

Concentration of three thrombin inhibitors in the nephrotic syndrome in adults.

Plasma antithrombin III (AT III), alpha 1-antitrypsin (alpha 1-AT) and alpha 1-macroglobulin (alpha 1-M) concentrations were measured in 17 cases of the nephrotic syndrome (NS) in adults. The mean plasma level of AT III was normal. The AT III concentration was correlated with albuminaemia (r = +0.718, p less than 0.005), cholesterolaemia (r = -0.651, p less than 0.005) as well as with urinary protein (r = -0.531, p less than 0.05). The alpha 1-AT concentration was decreased (p less than 0.01) and correlated with serum albumin level (r = +0.643, p less than 0.01). The alpha 1-M concentration significantly increased (p less than 0.001). A negative correlation of the alpha 1-M level with serum albumin concentration (r = -0.561, p less than 0.025) and a positive correlation with the cholesterol concentration (r = +0.819, p less than 0.001) was found. AT III and alpha 1-M were inversely correlated (r = -0.706, p less than 0.005). It is considered that in NS in adults, the increase of alpha 1-M is not compensatory for AT III, and there is no objection to the use of heparin in thrombosis prophylaxis with the exception of a few cases with very low AT III levels.

Adult↗
PubMed1986

Plasma fibronectin levels in patients with glomerular proteinuria.

Plasma fibronectin concentration was measured by means of rocket immunoelectrophoresis in 20 cases of glomerular proteinuria of various origins, and correlated with urinary protein loss, serum albumin, cholesterol and plasma alpha 1 antitrypsin and alpha 2 macroglobulin. Plasma fibronectin was significantly increased in the patient's group as compared to the controls (1.91 +/- 0.659 U/ml, 1.01 +/- 0.193 U/ml respectively, p less than 0.001) and correlated with cholesterolaemia (r = 0.662, p less than 0.001). Increased plasma fibronectin may be an additional risk factor for thrombotic tendency in NS.

Adult↗
PubMed1986

Shortening of bleeding time after intranasal administration of 1-deamino-8-D-arginine vasopressin to patients with chronic uremia.

1-deamino-8-D-arginine vasopressin (DDAVP) was administered intranasally in a dose of 2 micrograms/kg BW to 17 uremic patients (16 maintained on chronic hemodialysis and 1 treated conservatively). The bleeding time was significantly shortened 120 minutes after DDAVP administration (from 18.1 +/- 7.5 minutes to 12.3 +/- 6.4 minutes p less than 0.001). Factor VIII related antigen (VIII: Ag) did not change. Factor VIII ristocetin cofactor activity (VIII: RCof) significantly increased (from 251.2 +/- 162.0 to 336.5 +/- 167.2 p less than 0.025). Platelet count decreased significantly after DDAVP (from 174.9 +/- 43.8 X 10(9)/l to 155.6 +/- 45.9 X 10(9)/l 30 minutes p less than 0.01 and 129.8 +/- 45.2 X 10(9)/l p less than 0.005 120 minutes after DDAVP). Antithrombin III concentration, and hematocrit did not change. Our data indicate that further clinical studies of intranasal DDAVP in uremic patients during episodes of bleeding are warranted.

Administration, Intranasal↗
PubMed1985

Plasma thromboxane B2 in haemodialysed patients.

Plasma thromboxane B2 (TXB2) concentration was measured in 7 cases of terminal renal failure before and after haemodialysis. The TXB2 levels were higher in the investigated group than in the control group (p less than 0.05). Haemodialysis induced a further increase in the TXB2 concentration. Increased thromboxane production may play a part in the pathogenesis of accelerated atherosclerosis in uraemic patients treated with chronic haemodialysis.

Adult↗