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Biomedical subjects

L Pawlicki

Publications and source records attributed to L Pawlicki.

At least 19 recordsLinked to original sources

Activation of blood platelets after percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery.

We have evaluated the activation of platelets in blood samples taken from patients with stable angina undergoing balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) (n=11) or coronary artery bypass grafting (CABG) under hypothermic (n=11) or normothermic conditions (n=11). We have found that surface expression of P-selectin on platelets in whole blood from PTCA patients upon thrombin treatment was significantly reduced, as compared with control platelets from healthy subjects. This effect was partially reversed when platelets washed from the same blood sample were used, but even then P-selectin expression was significantly lower in PTCA patients than it was in control subjects. There was a significant increase in basal expression of P-selectin in blood platelets taken from patients who underwent CABG under normothermic conditions (warm blood cardioplegia) as opposed to hypothermic patients (cold crystalloid cardioplegia). These platelets retain the ability to respond to agonists, although to a much lower extent than do those from healthy control donors. The surface exposure of P-selectin on resting and thrombin-treated platelets isolated from CABG surgery patients was not different from that of the control platelets. The adhesion to fibrinogen of resting and thrombin-treated platelets from patients who underwent balloon angioplasty as well as CABG surgery under normothermic and hypothermic conditions was significantly reduced when compared with the fibrinogen of the control platelets. These results suggest that the function of platelet fibrinogen receptor is impaired in patients with stable angina pectoris and that PTCA and CABG surgery activates platelets.

Adult↗

[Effect of trimetazidine on biological activity of neutrophils in patients with transient myocardial ischemia induced by exercise testing].

We estimated the effect of trimetazidine on biological activity of neutrophils in patients with exercise test--induced transient myocardial ischaemia. The study group comprised 16 patients (10 men and 6 women) aged 40-56 years (mean 48.2 years) with stable angina. Exercise test was performed on cycloer-gometer (Medicor, Hungary). Trimetazidine in a dose 3 x 20 mg/day was applied 24 hours prior to the exercise test. The control group consisted of 14 patients (9 men and 5 women) aged 37-59 years (mean 47.9 years), with stable angina, in whom exercise test was performed but the drug was not administered. Blood samples for examination were taken from basilic vein before the exercise test and 10 min afterwards. To evaluate the ability of neutrophils to aggregate the leukergy test of Fleck modified by Berliner and Aronson was applied. Oxidative metabolism of nonstimulated and stimulated by fMLP and PMA was measured using chemiluminescence method. It was shown that in patients with stable angina trimetazidine caused decrease in neutrophil aggregation. The drug did not inhibit neutrophil biological activity af-ter exercise test--induced myocardial ischaemia.

Adult↗

[Stress echocardiography: methods, indications, clinical application].

Stress echocardiography is an accepted alternative method for non-invasive assessment of coronary artery disease--diagnosis, risk stratification and prognosis. Myocardial ischaemia triggers a cascade of events resulting first in regional relaxation abnormalities (or diastolic dysfunction) followed by regional motion abnormalities (or diastolic dysfunction). The basic principle in stress echocardiography is to provoke myocardial ischemia by exercise, pharmacologic interventions (like dobutamine, dipirydamole, enoximone, adenosine) or less often atrial pacing and subsequently to evaluate regional wall motion abnormalities in segments vascularized by coronaries with flow--limiting stenosis. Myocardial viability can be identified at the low dose dobutamine or dipirydamole stage as a functional improvement in regions with rest dyssynergy and myocardial ischaemia can be recognized at high doses as well motion dysfunction. The ideal test for evaluation of the patient with CAD remains exercise stress testing, pharmacologic stress should be reserved only for those patients in whom optimal workload of stress cannot be obtained. This article reviews the current status of stress echocardiography in clinical practice and assesses the possible indications for the tests in a modern cardiac department.

Cardiotonic Agents↗

Complement activates neutrophils during PTCA procedure in patients with unstable angina pectoris.

We estimated adherence, aggregation and chemiluminescence of neutrophils as well as concentrations of C3c, C4 and C5 complement components and complement haemolytic activity (CH50) in 27 patients with unstable angina pectoris subjected to percutaneous transluminal coronary angioplasty (PTCA). The control group consisted of 12 patients with unstable angina pectoris, in whom coronary angiography was performed but PTCA was decided against for various reasons. Blood samples for examination were taken from coronary sinus and peripheral vein just before, 1 min and 20 min after PTCA or coronary angiography. We observed enhancement of neutrophil adherence, aggregation and chemiluminescence, and decrease in concentrations of C3c, C5 and complement haemolytic activity (CH50) after PTCA procedure. In conclusion we think that ischemia resulting from PTCA causes complement activation in an alternative pathway which seems to be connected with neutrophil activation.

Acute-Phase Reaction↗

[Metabolic changes in blood oxygen in the human heart under ischemic and reperfusion conditions].

The number of granulocytes, their capability to generate O2-. and the activity of SOD-1, GSH-Px, Cat as well as MDA concentrations in erythrocytes in the blood extracted from the venous sinus and aorta under coronary artery bypass with use of St. Thomas cardioplegic solution were determined. The blood for examination was obtained before the institution of cardiopulmonary bypass, in the period of the deepest ischaemia (just after declamping of the aorta) and between the 1-3 minute and the 10-13 minute of reperfusion. A rise in the number of granulocytes both in the venous sinus and aortal blood at all examined intervals was noted. Capability to produce superoxide anion radicals decreased at the peak of ischemia and during reperfusion. The activity of SOD-1 was lower both after the period of ischemia and reperfusion. A rise in aortal blood activity during reperfusion was characteristic for GSH-Px; the activity was greater in the blood sampled from the coronary sinus during ischemia and initial reperfusion. With the exception of the initial reperfusion the activity of Cat diminished in all observed cases. We did not observe any significant changes in MDA concentration with the exception of the initial reperfusion in the aortal blood and later during reperfusion in the blood from the coronary sinus. The results demonstrate that the applied cardioplegic solution may protect myocardium from harmful effects of active oxygen froms produced as a results of ischemia and reperfusion.

Adult↗

[Adhesion and aggregation of neutrophils in patients with unstable angina].

The adherence and aggregation abilities of neutrophils (PMNs) were evaluated in thirty three patients with unstable angina, who were qualified for PTCA procedure. The control group consisted of forty one clinically healthy persons. The blood for investigations was obtained from coronary sinus and basilic vein just before the procedure, while in the control group from basilic vein only. The adherence of PMNs to plastic surface (rest and stimulated by PMA) was estimated in vitro according to Oez's et al. method by measuring optical density of generated formazan, whereas the aggregation of PMNs was evaluated using the leukergy test according to the method of Fleck in Berliner's and Aronson's modification. In patients with unstable angina statistically significant higher (p < 0.001) adherence of peripheral blood PMNs, compared with control groups was found (patients: rest-0.525 +/- 0.245, stimulated-0.839 +/- 0.419, control group: rest-0.260 +/- 0.129, stimulated-0.522 +/- 0.377). The aggregation of peripheral blood PMNs was significantly higher (p < 0.05) in the sick than in the control group (the sick-10.98 +/- 4.29%, controls-4.65 +/- 3.01%). No differences in investigated parameters of PMNs obtained from peripheral or coronary sinus blood were found.

Adult↗

[Generation of active oxygen species by neutrophils in patients with unstable angina pectoris].

The generation of O2-. and H2O2 by neutrophils (PMNs) obtained from peripheral and coronary sinus blood was investigated in twenty four patients with unstable angina, who were qualified for PTCA procedure. The control group consisted of twenty one clinically healthy persons. The blood for the investigations was obtained from coronary sinus and basilic vein just before the procedure, while in the control group from--basilic vein only. In patients with unstable angina statistically significant higher (p < 0.05) O2-. generation by peripheral blood PMNs (at rest and stimulated), compared with the control group, was found respectively (the sick: rest--11,09 +/- 1.92; stimulated--25.48 +/- 5.76 nmol/cell/min.; healthy: rest--7.98 +/- 1.06; stimulated--13.58 +/- 1.19 nmol/cell/min). No significant differences in O2-. generation between PMNs obtained from coronary sinus or peripheral blood were found. No differences in H2O2 generation by rest PMNs obtained from coronary sinus or peripheral blood were found in patients compared with the control group. The generation of H2O2 by PMA stimulated PMNs was higher in the sick without statistical significance.

Adult↗

The effect of short-term myocardial ischemia on the expression of adhesion molecules and the oxidative burst of coronary sinus blood neutrophils.

We examined the influence of transient myocardial ischemia on the number and function of neutrophils in patients with effort angina (EA). We tested fluorometrically the expression of neutrophil membrane molecules (CD11b, CD11c, CD18) and neutrophil oxidative burst using a chemiluminescence (CL) generation system. The estimations were conducted before, 1 min after and 20 min after percutaneous transluminal coronary angioplasty (PTCA) in 15 patients qualified for the treatment because of single-vessel disease. Eight EA patients subjected to coronary arteriography (CA) comprised a control group. We did not observe any marked changes in leucocytosis or lymphocyte number in peripheral blood (PB) or in coronary sinus blood (CSB) after the procedure. The percentage of granulocytes in coronary blood decreased significantly 20 min after reperfusion. No significant changes in white blood cell count were noted in peripheral blood of PTCA patients or in control CA subjects. Oxidative burst of nonstimulated and fMLP, PMA and zymosan stimulated sinus blood neutrophils was significantly depressed 1 min after inflation, and enhanced 20 min after reperfusion. We found a significant increase in the percentage of the CD11c+ neutrophils from 56.7 +/- 7.4% to 64 +/- 6.5% 20 min after inflation and postischemic decrease in the CD11c molecule expression on CSB neutrophils. Significant positive linear correlation (Rval = 0.71) between inflation time and the CD11c molecule expression on CSB immediately after reperfusion was also noted. The results may reflect local activation of neutrophils in ischemic myocardium as a response to ischemia induced increase of activating stimuli.

Angioplasty, Balloon, Coronary↗

[Some indices of peripheral blood oxidative metabolism during acetate and bicarbonate hemodialysis in patients with chronic uremia].

Whole blood superoxide anion generation, erythrocyte superoxide dismutase (SOD-1) and catalase activities and erythrocyte and plasma malonyldialdehyde concentrations were evaluated during cuprophane hemodialysis using bicarbonate and acetate dialysate. Superoxide anion generation by resting phagocytes was found to be significantly higher during bicarbonate hemodialysis, while its generation by opsonized zymosan--stimulated phagocytes did not differ between hemodialyses with both kinds of dialysates. Changes in the erythrocytes SOD-1 activities, found in the initial period of hemodialysis, were independent of the kind of dialysate, while erythrocyte catalase activity was higher during acetate hemodialysis in comparison with bicarbonate one. The kind of dialysate did not affect extent of erythrocyte membrane lipid peroxidation, while plasma lipid peroxidation was lower during acetate hemodialysis in comparison with bicarbonate one. In vitro studies with blood cells incubated with acetate or bicarbonate ions in concentrations, which are observed in vivo during hemodialysis, suggest that probably these ions do not directly affect superoxide anions generation, erythrocyte SOD-1 and catalase activities and erythrocyte membrane lipid peroxidation.

Acetates↗

[Influence of percutaneous transluminal coronary angioplasty (PTCA) on superoxide anion generation by whole blood granulocytes in patients with unstable angina pectoris (part I)].

In twenty patients with unstable angina, the effects of percutaneous transluminal coronary angioplasty (PTCA) on superoxide anion generation by neutrophils (PMNs) obtained from ulnar vein (UV) and coronary sinus (CS) were investigated. Blood samples for the investigations were taken from CS just before the procedure, within the first minute after the last balloon inflation and 20 minutes after PTCA; from BV--just before the procedure and 20 minutes following it. The results were compared with those obtained from 12 patients with unstable angina, (in whom coronary angiography was performed, but for various reasons angioplasty was desisted from) and with those obtained from 20 clinically healthy persons. In patients with unstable angina, the significantly increased O2.- generation by PMNs from CS and BV was found at rest as well as following opsonized-zymosan stimulation, compared with healthy persons. Within the first minute after PTCA, the significantly decreased O2.- generation by PMNs from CS was observed, compared with the results before the procedure (rest.--11.29 +/- 0.73 and 10.15 +/- 0.65 nmol/cell/min., p < 0.05; stimulation--27.62 +/- 6.25 and 18.54 +/- 3.37 nmol/cell/min., p < 0.05). Twenty minutes after PTCA O2.- generation by PMNs from CS still decreased (rest--9.23 +/- 1.08 nmol/cell/min., stimulation--15.71 +/- 5.98 nmol/cell/min.). In blood samples taken from BV before and after PTCA, no statistically significant differences in O2.- generation were observed (rest--11.32 +/- 0.79 nmol/cell/min. and 10.77 +/- 1.43 nmol/cell/min.; stimulation--25.96 +/- 6.12 nmol/cell/min. and 21.15 +/- 5.47 nmol/cell/min.).

Adult↗

[Influence of PTCA on neutrophil aggregation in patients with unstable angina pectoris (part II)].

In twenty patients with unstable angina, the effects of percutaneous transluminal coronary angioplasty (PTCA) on aggregation of neutrophils (PMNs) obtained from coronary sinus (CS) and basilic vein (BV) were investigated. Blood samples for the investigations were taken from CS just before the procedure, within the first minute after the last balloon inflation and 20 minutes after PTCA; from BV--just before and 20 minutes after the procedure. The results were compared with those obtained from 12 patients with unstable angina (in whom coronary angiography was performed, but for various reasons angioplasty was desisted from) and with those obtained from 20 clinically healthy persons. In patients with unstable angina the significantly higher percent of aggregated PMNs from CS as well as from BV was found, compared with healthy persons. Within the first minute after the procedure, the significantly increased percentage of aggregated PMNs from CS compared with the results before the procedure, was observed (10.50 +/- 4.06% and 18.36 +/- 7.69%, p < 0.05), but 20 minutes after, the value of the investigated parameter decreased to 5.88 +/- 2.86% and was similar to that in healthy persons. One minute after the procedure, in patients in whom PTCA was performed, the significantly decreased PMNs number in the blood obtained from CS was found, compared with the results before PTCA (4295 +/- 840 and 3850 +/- 825; p < 0.05). Twenty minutes after the procedure no further decrease of PMNs number was observed. In patients with or without PTCA no changes in the number and aggregation of PMNs obtained from BV were observed.

Adult↗

Increased platelet-fibrinogen interaction in patients with hypercholesterolemia and hypertriglyceridemia.

Binding of fibrinogen to platelets washed from the blood of patients with hypercholesterolemia and hypertriglyceridemia (n = 25) and control donors (n = 12) was compared. In addition, the content of platelet glycoprotein IIb was determined by radioimmunoassay. Fibrinogen was bound in significantly higher amounts (P < 0.02) to hyperlipidaemic platelets activated by ADP than to control ones (107,112 +/- 16,371 and 45,612 +/- 6495 molecules per platelet, respectively). The mean content of GPIIb was the same in hyperlipidaemic and in control platelets (2.06 +/- 0.16 and 1.94 +/- 0.21 micrograms/10(8) platelets, respectively). The amount of fibrinogen bound to the activated hyperlipidaemic platelets showed a positive correlation with total plasma cholesterol and LDL (r = 0.45 and 0.47, respectively) whereas a negative correlation with plasma HDL was found (r = -0.50). The increased expression of fibrinogen binding sites similar to that of hyperlipidaemic platelets could be produced by preincubation of normal platelets with palmitic acid. This was evidenced by a significant increase of fibrinogen binding sites in control platelets. This suggests that either palmitoylation of the receptor or microenvironment changes in the membrane lipid bilayer may be responsible for the enhanced platelet receptor capacity to bind fibrinogen.

Adenosine Diphosphate↗

Whole blood superoxide anion generation and efficiency of some erythrocyte antioxidant systems during recombinant human erythropoietin therapy of uremic anemia.

Six chronic uremic patients on regular hemodialysis treatment were given recombinant human erythropoietin (r-huEPO) in a dose of 50 U/kg of body weight intravenously thrice weekly for 14 weeks. Following r-huEPO therapy, unstimulated whole blood superoxide anion (O2) generation did not change significantly, while opsonized zymosan-stimulated whole blood O2 generation increased. At the same time, erythrocyte superoxide dismutase and, in particular, glutathione peroxidase activities were found to be reducing with concomitant lowering of erythrocyte malonyldialdehyde (MDA) concentrations and increase in plasma MDA concentrations.

Adolescent↗

[Generation of active oxygen compounds by whole blood granulocytes in patients with chronic renal failure].

In patients with chronic renal failure (crf) on conservative treatment whole blood granulocyte superoxide anion (O2-) generation was significantly decreased. Regular hemodialysis treatment did not induce its significant improvement. As granulocyte O2- generation determines production of other active oxygen compounds, this phenomenon may lead to the impairment of phagocyte bactericidal activity and increased susceptibility to infections in crf. Various methods of determination of active oxygen compounds give incomparable results.

Adolescent↗

Superoxide anion generation and lipid peroxidation processes during hemodialysis with reused cuprophan dialyzers.

In 11 chronic uremic patients superoxide anion (O2-.) generation and lipid peroxidation processes were determined during hemodialyses with cuprophan dialyzers used three times. Intradialytic changes observed during the first 20 min of hemodialysis, that is the period of the most marked alterations, with consecutive uses of the same dialyzer included: decreased whole blood O2-. generation at rest and following stimulation with opsonized zymosan, decreased reductions in the erythrocyte superoxide dismutase (SOD-1) activity, increased reductions in the plasma malonyldialdehyde (MDA) concentrations, and unchanged erythrocyte MDA concentrations. However, immediately before hemodialysis with third-used dialyzer whole blood O2-. generation at rest and following opsonized-zymosan stimulation, and erythrocyte SOD-1 activity were slightly, but statistically significantly, lower (p less than 0.05), while plasma MDA concentrations were higher (p less than 0.05) than those before hemodialysis with first-used dialyzer; erythrocyte MDA concentrations remained unchanged. The results seem to indicate that dialyzer reuse may exert beneficial effects on whole blood O2-. generation and protect erythrocyte membrane lipids from peroxidation, but, however, it leads to slightly increasing predialysis plasma lipid peroxidation.

Adult↗

[Spontaneous rupture of the spleen as a cause of death of a patient with uremia].

A case of spontaneous rupture of the spleen in young patient with uremia treated with hemodialyses is presented. A course of the disease was acute with severe shock leading to patient's death. Possible edema of the spleen and subcapsular hematomas related to the uremic coagulopathy and the use of heparin during hemodialyses may be the factors predisposing to the rupture of the spleen.

Adult↗