Catalase and chondroitin sulfate derivatives against thrombotic effect induced by reactive oxygen species in a rat artery.

Antithrombotic activity of catalase (CAT) and chondroitin sulfate (CHS) preparations was studied in a rat model of arterial injury induced by ferrous chloride. Equal doses (according to catalytically active CAT) were used to examine the effect of native CAT, CAT-CHS covalent conjugate and mixture of native CAT and free CHS in a ratio corresponding to their contents in the conjugate. The antithrombotic activity of the derivatives was determined by the time during which arterial occlusion developed (occlusion time) and by the mass of the formed thrombus.

Role of the glycosaminoglycan microenvironment of hyaluronidase in regulation of its endoglycosidase activity.

The glycosaminoglycan microenvironment of testicular hyaluronidase was simulated by multipoint covalent attachment of the enzyme to glycans as a result of benzoquinone activation. The efficiency of their binding was assessed using gel chromatography, ultrafiltration, titration of surface amino groups of the enzyme, electrophoresis, as well as judging by the value of residual endoglycosidase activity and its inhibition with heparin. Copolymer glycosaminoglycans, such as dermatan sulfate and heparin, inactivated the endoglycosidase activity as a result the C-5 epimerization of hexuronic acid.

Role of glycoprotein IIb-IIIa (alpha IIb beta 3-integrin) in stimulation of secretion from platelet granules.

The involvement of glycoprotein (GP) IIb-IIIa (alphaIIbbeta3-integrin) in the stimulation of secretion from platelet dense and alpha-granules was investigated. Fibrinogen binding with GP IIb-IIIa and platelet aggregation were inhibited by fragments of anti-GP IIb-IIIa monoclonal antibodies (monAB)--Fab fragment of antibody c7E3 (preparation ReoPro) and F(abacute;)(2) fragment of antibody FraMon (preparation FRAMON). Suppression of GP IIb-IIIa receptor activity by both preparations led to 100% inhibition of [(14)C]serotonin secretion from dense granules upon platelet activation with ADP, to partial inhibition upon activation with thromboxane A(2) analog U46619 (by 60-70%) and thrombin at 0.

Activation of p38 MAP-kinase and caldesmon phosphorylation are essential for urokinase-induced human smooth muscle cell migration.

We have explored intracellular pathways involved in the urokinase type plasminogen activator (urokinase or uPA)-stimulated migration of human airway smooth muscle cells (hAWSMC). Using a set of uPA mutants we found that protease activity, growth factor-like and kringle domains of uPA differentially contribute to activation of p42/p44erk1,2 and p38 MAP-kinases. Consistent with our earlier data [Mukhina et al.

Plasminogen activators in vascular remodeling and angiogenesis.

This review considers cellular and molecular mechanisms of the involvement of plasminogen activators in extracellular proteolysis and cell migration and proliferation. The role of plasminogen activators in vascular remodeling in atherosclerosis, restenosis, and angiogenesis is discussed.

Urokinase as a multidomain protein and polyfunctional cell regulator.

The urokinase type plasminogen activator (urokinase) plays a pivotal role in the regulation of cell adhesion and migration during tissue remodeling. Urokinase not only specifically cleaves plasminogen and converts it into plasmin but also activates intracellular signaling upon binding to certain receptors on the cell surface. The polyfunctional properties of this protein are associated with its three-domain structure as follows: the C-terminal proteolytic domain containing the serine protease active center, the central kringle domain, and the N-terminal domain homologous to epidermal growth factor.

The fibrinolysis system: regulation of activity and physiologic functions of its main components.

This review summarizes basic properties and mechanisms of activation and inhibition of main components of the fibrinolytic system that, acting in accord with the system of blood coagulation, provides temporal formation of fibrin clots at sites of vascular injury for the time required for the regeneration of vascular wall. Impairments in the fibrinolytic system may cause bleedings or thrombotic complications in patients. The predictive value of some components of the fibrinolytic system with respect to the development of complications of atherothrombosis is considered.

Thrombolysis research--new objectives after a shift of accent.

The methods of increasing the efficacy of thrombolysis under clinical and experimental conditions are have been discussed in the light of analysis of current tendencies in the investigation and development of thrombolytic and adjunctive therapy. Analysis of the data obtained in the search for novel plasminogen activators for thrombolytic enzyme therapy has shown a decrease and depletion of this search. The reserves for further increase in thrombolysis efficiency have been notified.

[Free radical centers in the dog myocardial tissue in regional ischemia].

The effect of regional ischemia on canine myocardial in situ free radical species was studied by the EPR method. Rapid fixation of heart muscle samples by freezeclamping was performed at the following physiological states: native myocardial blood circulation, regional ischemia with the presence of collateral circulation, total ischemia, and postischemic reperfusion. EPR spectra of the samples at -40 degrees C exhibited two free radical signals from the semireduced forms of ubiquinone and flavine coenzymes.

[Triple interpolyelectrolyte complexes DNA-polycation-polyanion: a new approach to optimization of mixtures for transfection in eukaryotic cells].

A new approach to optimization of mixtures for the condensation and introduction of plasmid DNA into eukaryotic cells is proposed, which is based on the formation of ternary interpolyelectrolyte complexes (IPEC) DNA/polycation/polyanion. Polyethyleneimine (PEI) with M 30-40 kDa as polycation and polyacrylic acid (PA) with M 20 kDa or its grafted copolymer with polyethyleneglycol (PEG) as polyanion were used, and ternary complexes with various ratios of the components were prepared. The PA-PEG incorporation into a ternary complex (by itself or as a 1:1 mixture with PA) was shown to confer the solubility onto complexes in a wide range of DNA/PEI ratios.

Isolated replacement of the mitral leaflets and "Mercedes"-plastics of the giant left atrium: surgery for patients with left ventricle dysfunction and left atrium enlargement.

Background: The main goal of the present surgery is to develop a new complex of surgical procedures for patients with long-standing mitral valve incompetence, severe left atrium (LA) and left ventricle (LV) enlargement (secondary cardiomyopathy).

Methods: Seven patients were operated on using a new technique. Normal LA shape and size were restored by symmetrical "Mercedes"-plastics of the posterior LA wall.

Resistance of dextran-modified hyaluronidase to inhibition by heparin.

Properties of native and aldehyde dextran-modified hyaluronidase (with surface amino group modification about 98%) were investigated. Optimal endoglycosidase activity of the native enzyme was observed at 0.15 M NaCl and pH 5.

Chemical modification of hyaluronidase regulates its inhibition by heparin.

Chemical modification of surface amino groups of bovine testicular hyaluronidase with aldehyde dextran was conducted. It was found that with the increase of modification degree of hyaluronidase amino groups the value of residual enzymatic catalytic activity is decreased rather monotonously. It turned out that the value of inhibition of enzyme activity by heparin considerably depends on modification degree of enzyme.

[Effect of ischemic preconditioning on free radical centers of the isolated rat heart during ischemia and early reperfusion].

The effect of ischemic preconditioning on the free-radical state of isolated rat myocardium fixed by rapid freezing at the 25th min of normothermic total ischemia and the 3rd min of reperfusion was studied by the EPR method. It was shown that EPR spectra registered at -40 degrees C consist of two free-radical signals: of the semireduced forms of ubiquinone and flavine coynzymes. It was found that during ischemia and at the beginning of reperfusion, the preconditioning results in a narrowing of the spectra (as compared with control) due to an increase in the narrow ubisemiquinone EPR signal portion, and a decrease in the total concentration of free-radical centers: by 16% in the case of ischemia, and 23% in the case of reperfusion.

Antithrombotic activity of the superoxide dismutase-chondroitin sulfate complexes in a rat model of arterial injury.

Individual antithrombotic activities of superoxide dismutase (SOD) and sodium chondroitin sulfate (CHS) as well as the activities of covalent and noncovalent complexes of SOD with CHS were compared in a rat model of arterial thrombosis induced by ferrous chloride. Covalent conjugate of SOD with CHS exerted the most potent antithrombotic effect, which was associated with adsorption of the conjugate on the glycocalyx of the vascular wall cells and stability of the covalent bond between CHS and SOD subunits. Theoretical and practical directions in the investigation of SOD and CHS preparations are outlined.

[Registration of residual oxygen in the area of regional myocardial ischemia by ESR].

An experimental approach for recording molecular oxygen in the area of regional myocardial ischemia by using the method of microdialysis and spin label CTPO is presented.

Unique sequence of a high molecular weight myosin light chain kinase is involved in interaction with actin cytoskeleton.

Myosin light chain kinase (MLCK) is the key regulator of cell motility and smooth muscle contraction in higher vertebrates. We searched for the features of the high molecular weight MLCK (MLCK-210) associated with its unique N-terminal sequence not found in a more ubiquitous lower molecular weight MLCK (MLCK-108). MLCK-210 demonstrates stronger association with the Triton-insoluble cytoskeletons than MLCK-108, suggesting the role for this sequence in subcellular targeting.

[Features of atherosclerosis in the ascending human aorta and the link between its development and the main risk factors of ischemic heart disease in patients after aortocoronary shunting].

Atherosclerosis was found in all ascending aorta biopsies of 125 patients aged 42 to 65 years who underwent aortocoronary bypass surgery. Lipid spots only were found in 91.2% of cases, in 11 patients (8.

[Hyperplastic changes and aldosterone content in the adrenal cortex in essential hypertension and primary aldosteronism].

Autopsy and operative material (adrenalectomy for hyperaldosteronism) was studied to elucidate morphology, incidence of nodules, aldosterone content in the adrenal of patients with essential hypertension (EH). It was established than nodular masses in the adrenals in the form of micro and macronodules are present in 80% of EH patients. Aldosterone content in the adrenals in both nodules and in the adjacent cortex is significantly higher than in the adrenals of patients without EH.

[Changes in suprachiasmatic and paraventricular hypothalamic nuclei in essential hypertension].

Suprachiasmatic and paraventricular hypothalamic nuclei (SCN and PVN, respectively) were studied in humans with essential hypertension (EH) and in healthy individuals who had normal blood pressure and died by accident (control group). Immunohistochemistry, hybridization in situ using computer image analysis have shown that EH patients have decreased number of vasopressin (VP) positive cells in SCN, high number of corticotropin-releasing hormone (CRH) producing neurones in PVN and increased amount of mRNA for CRH in them. A negative linear correlation was found between the number of CRH-producing cells in PVN, amount of mRNA for CRH in them and the number of VP-synthesizing cells in SCN.

New thrombolytic strategy: bolus administration of tPA and urokinase-fibrinogen conjugate.

Increased efficacy of thrombolytic therapy requires a comprehensive search for new and novel therapeutic strategies. Many new modified forms of plasminogen activators have been obtained by means of chemical and biological synthesis. However, clinical findings demonstrate that the reperfusion level achieved during thrombolysis remains the same for various thrombolytic agents, irrespective of an extensive search for an "ideal" thrombolytic.

Mechanisms of vascular wall calcium relaxation.

Using the method of isometric tension measurement in isolated blood vessels, we investigated some mechanisms of action of high calcium concentrations (>3 mM) on the mechanical activity of small branches of the rat mesenteric artery. Calcium in concentrations up to 30 mM caused relaxation of the arteries (calcium relaxation). The amplitude of the effect decreased in the presence of ouabain (10(-4) M), tetraethylammonium (10(-3) M), charibdotoxin (10(-7) M) and in the potassium-free external solution in intact and denuded rings.

New strategy of thrombolysis. Conjunctive effect of plasminogen activators with different pharmacokinetic profile.

Combined actions of native and prolonged thrombolytics allow the use of lower doses and simplified schemes of administration, thus yielding significant results in experimental therapy regarding the efficacy and safety of thrombolysis. Development of prolonged forms of plasminogen activators and testing their effect in combination with the thrombolysis trigger are well founded and of current interest. Thrombolytic compositions on the basis of short- and long-term-acting plasminogen activators appear to be promising and potentially eligible for bolus administration.

[Antithrombotic effect of catalase and chondroitin sulfate derivatives in arterial damage in rats].

The antithrombotic action of catalase and chondroitin sulfate derivatives was studied on the rat arterial thrombosis induced by treatment of vessel with ferrous chloride solution. The effect of native or chondroitin sulfate modified catalase, as well as the mixture of native catalase and free chondroitin sulfate in ratio which is equal to their content in conjugate was compared in respect to corresponding doses according to active catalase content. The antithrombotic action of conjugate and its component mixture is rather similar with each other and significantly exceeds the effect of native enzyme.