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Biomedical subjects

M Kopeć

Publications and source records attributed to M Kopeć.

At least 19 recordsLinked to original sources
PubMed1996

[Isoptin SR-240 and SR-120 in ambulatory treatment of arterial hypertension].

Arterial hypertension, especially when co-exists with ischemic heart disease, makes an important clinical and social problem. Necessity to continue a treatment during the whole patients life produces many problems for a patient himself as well as for a physician. Thus, for many years, researches have been carried out to find a medicine that would allow to fully control blood pressure for all day, would have minimal side-effects and could be administered once a day. Beside convertase inhibitors such as Prestarium and Gopten, calcium channel blockers, especially retard verapamil forms like Isoptin SR-240 and SR-120 seem to be the most appropriate medicines, especially when hypertension is accompanied by ischemic heart disease and dysrrythmias. The study was performed in 150 hypertensive patients who were administered Isoptin SR-240 once a day and Isoptin SR-120 twice a day. That dose was sufficient to normalize benign and mild hypertension in most patients. Decreased frequency of dyshrrytmias and chest pain relief were also observed. Trials to increase daily dose up to 360 mg were accompanied by evident side effects such as dizziness and constipations. Much more profitable was to join lower Isoptin dose with convertase inhibitors and diuretics.

Adult↗
PubMed1995

Effects of human neutrophil elastase and cathepsin G on the reactivity of platelets with antiplatelet antibodies.

Two human neutrophil serine proteases, elastase (HNE) and cathepsin G (CathG), are known to change the structure and hemostatic function of platelet surface membrane. The platelet membrane contains glycoproteins (GPs) which function as alloantigens, autoantigens and targets of drug-induced antibodies. The aim of this study was to investigate whether proteolysis of platelet GPs by HNE and CathG is associated with changes in the reactivity of platelets to antiplatelet antibodies. The platelet immunoreactivity was examined using the MAIPA (monoclonal antibody-specific immobilization of platelet antigens) assay and PSIFT (platelet suspension immunofluorescence test). The treatment of platelets with HNE led to a moderate increase in their reactivity to quinidine-dependent (anti-GP Ib) antibody and to a slight decline in the expression of HPA-1a. In contrast, CathG did not provoke any significant changes in platelet reactions with quinidine dependent and anti-HPA-1a antibodies. Both enzymes had no significant effect on the expression of HLA-A2, HLA-A3, HLA-B7 and HLA-B8 on platelets.

Antibodies↗
PubMed1994

Secretory response of the vessel wall to DDAVP and venous occlusion in von Willebrand's disease.

The aim of this study was to compare the secretory response of the vascular wall in vivo to DDAVP (i.v. 0.3 microgram/kg, 30 min) and to venous occlusion (VO, 20 min) in control healthy subjects, patients with von Willebrand's disease type I (vWd I) and patients with von Willebrand's disease type III (vWd III). In controls (n = 10) and vWd I (n = 12), DDAVP induced a 2 to 3-fold rise in plasma von Willebrand factor antigen (vWf: Ag), factor VIII coagulant activity (VIII: C) and tissue--type plasminogen activator antigen (t-PA:Ag). VO was less effective in increasing vWf: Ag and VIII:C but produced a greater rise in t-PA:Ag. Large increments (over 10-fold) were observed in plasmin-alpha 2-antiplasmin complexes following both stimuli. In vWd III (n = 10), DDAVP and VO failed to increase vWf:Ag, VIII:C and t-PA:Ag. No significant changes in plasmin-alpha 2-antiplasmin complexes were observed in this group. Moreover, the baseline t-PA:Ag values were significantly lower in vWd III (2.17 +/- 1.13 ng/ml) than in controls (4.84 +/- 1.97 ng/ml, p < 0.001). A significant increase in urokinase--type plasminogen activator antigen (u-PA:Ag) was found only in controls after VO. Neither controls nor patients with vWd showed any changes in plasma fibronectin levels following DDAVP. The low t-PA:Ag results and the abnormal fibrinolytic response to DDAVP and VO in patients with severe (type III) vWd indicate that their endothelial cell abnormality is more extensive than the defect in the synthesis or release of vWf.

Adult↗
PubMed1993

Degradation of human erythrocyte surface components by human neutrophil elastase and cathepsin G: preferential digestion of glycophorins.

Human erythrocytes treated with purified human neutrophil elastase (HNE) or cathepsin G (CathG) were analysed by serological methods and by SDS-polyacrylamide gel electrophoresis followed by staining or immunoblotting with monoclonal antibodies. Both enzymes digested exhaustively glycophorins A, B and C, and HNE caused a partial digestion of band 3 protein. The degradation of other membrane proteins was not detectable by the methods used. Immunoblotting with the use of monoclonal antibodies against the defined epitopes of glycophorin A showed that HNE and CathG hydrolysed distinct peptide bonds in this antigen. The antibody PEP80, specific for the epitope in the cytoplasmic fragment of glycophorin A, gave patterns of bands which were characteristic for each of the two proteases. These bands could be distinctly identified in erythrocyte membrane samples containing only few percent of digested glycophorins. Therefore, the immunoblotting with this antibody may be useful as a sensitive assay for detecting the action of neutrophil proteases on red blood cells.

Cathepsin G↗
PubMed1991

Fibrinogen does not protect von Willebrand factor against proteolysis by human cathepsin G.

The susceptibility of von Willebrand factor /vWF/ to digestion by human neutrophil cathepsin G in highly purified FVIII/vWF concentrate /BHS/ and in cryoprecipitate has been studied. In contrast to human neutrophil elastase, cathepsin G inactivates and degrades vWF not only in BHS but also in cryoprecipitate. Fibrinogen added in excess to purified FVIII/vWF concentrate does not protect vWF against cathepsin G proteolysis. Biological significance of this phenomena are discussed.

Cathepsin G↗
PubMed1990

Venostasis but not DDAVP infusion provokes the plasma fibronectin increase.

Plasma fibronectin (pFN), von Willebrand factor antigen (vWf:Ag), factor VIII procoagulant activity, fibrinogen, euglobulin lysis time (ELT) and hematocrit were determined in healthy blood donors before and after venostasis as well as after intravenous infusion of 1-deamino-8-D-arginine vasopressin (DDAVP). Both venostasis and DDAVP provoked an increase in vWf:Ag and shortening in the ELT. In contrast, venostasis only but not DDAVP induced an increase in pFN levels which was statistically significant with and without correction for a concomitant hematocrit increment. The results indicate that there is a distinct difference in the patterns of venostasis and DDAVP mediated release of proteins from the vessel wall.

Adult↗
PubMed1990

Different effects of human neutrophil elastase on platelet glycoproteins IIb and IIIa of resting and stimulated platelets.

The effect of human neutrophil elastase (HNE) on the structure and receptor activity of platelet glycoprotein IIb/IIIa complex was studied. Resting platelets, which bound only traces of 125I-fibrinogen in the absence of ADP, were found to be barely susceptible to HNE. As shown by immunoblotting experiments, treatment of such platelets with HNE (14 micrograms/ml) did not provoke a detectable cleavage of GPIIb but resulted in a partial digestion of GPIIIa and appearance of 110 kDa fragment. Such proteolytic modification of the GPIIb/IIIa complex was accompanied by a slight increase in the binding of fibrinogen to blood platelets in the absence of ADP. Treatment of partially activated platelets (spontaneous activation during washing procedure) with HNE caused a progressive loss of GPIIb and degradation of GPIIIa to 110 kDa and 60 kDa fragments. These spontaneously stimulated platelets had initially a high number of fibrinogen binding sites exposed, corresponding to approximately 50% of receptor capacity observed in platelets activated by the optimal concentration of ADP. Digestion of GPIIb/IIIa by HNE of such platelets markedly increased the exposure of fibrinogen receptors. Thus, the stimulation of platelets increases significantly the susceptibility of the GPIIb/IIIa complex to proteolysis by HNE. However, such modification of the GPIIb/IIIa does not destroy its function as a receptor for fibrinogen either on the resting or activated platelets.

Blood Platelets↗
PubMed1990

Effects of human elastase on von Willebrand factor in highly purified factor VIII concentrate and in cryoprecipitate.

The susceptibility of v. Willebrand factor (vWF) and F.VIII in virus-inactivated factor VIII/vWF concentrate (Behring-Haemate-HS (BHS] and in cryoprecipitate (Behring-Ristofact) to digestion by highly purified, cathepsin G free human neutrophil elastase (HNE) was compared. In Haemate-HS HNE induced a degradation of the vWF subunit. This reaction was dependent on time and enzyme concentration. It resulted in disappearance of large size vWF multimers, an anodal shift of vWF peak in crossed immunoelectrophoresis and a decrease of F.VIII:C and Ristocetin cofactor activities. In contrast in cryoprecipitate even high HNE concentration did not provoke changes of these parameters. Both Haemate-HS and Ristofact were free of alpha 1-proteinase inhibitor (alpha 1 PI) and alpha 2-macroglobulin (alpha 2 M) but they differed in the content of other contaminating proteins. In particular Haemate-HS was fibrinogen-free but Ristofact contained 6.6 mg/ml. Purified fibrinogen added to Haemate-HS was found highly effective in protecting vWF in Haemate-HS against the proteolytic degradation and loss of activity under the influence of HNE.

Factor VIII↗
PubMed1988

Anti-inflammatory drugs modulate histamine release from mast cells induced by fibrinogen degradation products.

The products resulting from proteolytic degradation of human fibrinogen (FDP) were found to induce the release of histamine from rat peritoneal mast cells. Low molecular weight, dialysable peptides (FDP) showed the highest dose dependent, histamine releasing activity. Histamine release induced by FDP was effectively inhibited by the gold compound auranofin at a concentration of 10(-5)-10(-7) mol/l and also by the non-steroidal anti-inflammatory drugs BW 755c, timegadine, medosan, naproxen, and aspirin at the higher concentration range of 10(-4)-10(-6) mol/l. It is concluded that the release of histamine from mast cells may be modulated to some extent by anti-inflammatory drugs, especially auranofin, BW 755c and timegadine, a functional property which may be beneficial in the management of joint disease.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1985

Anticoagulant properties of extracellular slime substance produced by Staphylococcus epidermidis.

Slime produced by S. epidermidis strain KH 11 was extracted with phenol-saline. The saline phase was fractionated on a DEAE-Sepharose CL-6B column. The crude slime solution and its phenol-saline fraction were found to possess anticoagulant properties. They inhibited the coagulation of human plasma by thrombin, prolonged the activated partial thromboplastin time, but did not change the rate of plasma coagulation by reptilase. The anticoagulant effect of slime could be neutralized by rather high concentrations of protamine sulphate. In the presence of plasma, the staphylococcal slime also inhibited in a concentration dependent fashion the amidolytic activity of thrombin and factor Xa against synthetic chromogenic substrates. Both antithrombin III (AT III) and other plasma component(s), presumably heparin cofactor II, were required for the full expression of the slime effect. The anticoagulant action of slime was markedly less AT III dependent than that of heparin. The activity was resistant to heating (100 degrees C, 30 min). Slime and its fractions were stronger inhibitors of thrombin than of factor Xa. Fraction IV separated by DEAE-Sepharose chromatography and particularly rich in galactose and glucuronic acid had the highest inhibitory potency. It is conceivable that slime component(s) similar to glycosaminoglycans from other sources can carry the anticoagulant activity.

Anticoagulants↗