A total of 360 patients with different stage of chronic cerebral ischemia (CCI) were studied. Of these, 180 patients, observed for 12 months from initial assessment, were divided into two groups depending on the course of illness – favorable (stable) and unfavorable (progressive or with acute episodes of impaired cerebral circulation). Markers of oxidative stress were assessed in terms of the level of lipid (malondialdehyde) and protein (carbonyl protein oxidation products, plasma SH groups levels, and accumulation of advanced oxidation protein products (AOPP) in plasma. Along with measures of oxidative stress, the binding capacity of albumin was also determined, using the fluorescent probe K-35. Initial values for these markers were measured, along with concentrations after copper ion-induced oxidation of plasma. The greatest increases in measures of oxidative stress were seen in patients with acute episodes of circulatory failure. Significant differences were found in measures of oxidative stress in groups of patients with different clinical variants of the course of CCI and qualitative and quantitative diagnostic criteria suggesting an unfavorable course of illness and the risk of developing stroke were established. The ability to diagnose a prognostically unfavorable course of illness allows appropriate treatment to be started in a timely fashion.

Цель — исследовать содержание конечных продуктов перекисного окисления липидов (малоновый диальдегид (МДА) в нативной плазме и после медь-индуцированного окисления плазмы) у пациентов с острым коронарным синдромом (ОКС), оценено влияние этих показателей на краткосрочный (30-дневный) прогноз. Материал и методы. В исследование включены 93 пациента с ОКС, которым при включении и на 7-й день заболевания определялся МДА в нативной плазме и после медь-индуцированного окисления плазмы. В зависимости от наступления первичной конечной точки (смерть от сердечно-сосудистых причин, рецидив инфаркта миокарда, развитие ранней постинфарктной стенокардии, потребность в экстренной реваскуляризации в течение первых 30 дней) пациенты были разделены на две группы: благоприятного и неблагоприятного течения заболевания. Результаты.У пациентов с ИМ с подъемом сегмента ST (STEMI) содержание МДА в нативной плазме было достоверно выше, чем у больных с другими формами ОКС (p=0,019). Содержание МДА в нативной плазме не различалось у пациентов с различным течением заболевания. При МДА после медь-индуцированного окисления плазмы на 7-й день выше 112 нмоль/мл относительный риск рецидива инфаркта миокарда возрастал в 2,4 раза (95% ДИ 1,04—4,78; р=0,046). Заключение. Результаты данного исследования позволяют говорить о том, что окисляемость липидов плазмы крови можно использовать для оценки риска неблагоприятного течения заболевания у пациентов с ОКС. Ключевые слова: малоновый диальдегид в нативной плазме, малоновый диальдегид после медь-индуцированного окисления плазмы, острый коронарный синдром, краткосрочный прогноз. Aim — we estimated malondialdehyde (MDA) and thiobarbituric acid-reactivity in patients with acute coronary syndrome (ACS). We also evaluated the prognostic value of these markers in short-term prognosis in patients with ACS. Material and methods. We enrolled 93 patients with ACS. The MDA and thiobarbituric acid-reactivity were measured at first 24 hours and 7 days after admission. We divided patients in two groups according to primary end point (death from cardiovascular causes, nonfatal myocardial infarction, refractory angina and emergency revascularization within 30 days after ACS). Results. In patients with ST-elevation myocardial infarction the MDA level was significantly higher than in those with other forms of ACS (p=0.019). MDA level did not differ between groups. In patients with thiobarbituric acid-reactivity level higher than 112 nmol/ml at the 7 day hazard ratio of nonfatal myocardial infarction was 2,4 (95% CI 1.04—4.78; р=0.046). Conclusion. Lipid peroxidation end products (MDA and thiobarbituric acid-reactivity) might be used for risk assessment in patients with ACS.

We studied hemolytic activity of gold nanoparticles added to the whole blood (ex vivo) and of nanoparticles coated and not coated with plasma components on erythrocytes in hypotonic medium (osmotic hemolysis) in vitro. Gold nanoparticles did not stimulate erythrocyte hemolysis after 4-h incubation with the whole blood ex vivo. Hemolysis tended to increase in the presence of small gold nanoparticles (5, 10, 20 nm) at the maximum concentration of 20 μM (by gold content) used in our study in comparison with the control. This tendency was detected during the 1st hour of the nanoparticles incubation with blood. Gold nanoparticles in the used concentrations (up to 20 μM of gold) coated with plasma components after preincubation with autologous plasma and nanoparticles without coating caused no osmotic hemolysis of erythrocytes in vitro.

We studied the effect of gold nanospheres coated with components of autologous blood plasma on ADP-induced platelet aggregation. Gold nanoparticles in the chosen concentration range (5–40 μM) and particle size (5–30 nm) with or without coating produced no activating effect on platelet aggregation caused by aggregation inductor ADP in all applied doses (1.6, 2.0, and 5.0 μM). Nanoparticles with a diameter of >60 nm inhibited platelet aggregation. These findings and published data confirm the biological safety of gold nanoparticles for targeted delivery of drugs and phototherapy.

Authors studied 360 patients with different stages of chronic cerebral ischemia (CBI), including 180 patients followed-up for 12 months after the first examination, who were stratified into two groups with regard to disease course - favorable (stable) and unfavorable (progressive or with acute episodes of cerebral blood circulation disturbance). Oxidative stress markers were evaluated by the level of lipid- (malonic dialdehyde) and protein - (carbon products of protein oxidation, the level of plasma SH-groups, the accumulation of the products of deep oxidation of proteins) oxidation. Along with indicators of oxidative stress, we evaluated the binding capacity of albumin using fluorescent probe K-35. Initial level of these markers and their concentrations after the copper ion induced oxidation of the plasma were determined. The highest increase in oxidative stress indicators was seen in patients with acute episodes. Authors identified significant differences in these indicators in the groups of patients with different clinical variants of CBI course as well as qualitative and quantitative diagnostic criteria of unfavorable course and risk of stroke. Our findings suggest that the imbalance of oxidative-antioxidative system contributes to the course of CBI. Prediction of unfavorable course of CBI determines the timeliness of adequate treatment.

We studied the effect of gold nanoparticles on ROS production by leukocytes. ROS production was detected by luminol-dependent chemiluminescence (LDCL) of human peripheral blood leukocytes stimulated with opsonized zymosan. Nanoparticle size was 5, 10 and 30 nm. Simultaneous addition of nanoparticles and opsonized zymosan showed that 5-nm nanoparticles inhibited LDCL intensity in comparison with the control, when LDCL recording was conducted in the presence of opsonized zymosan. Increasing nanoparticle size from 5 up to 30 nm enhanced LDCL intensity. Preincubation of gold nanoparticles with autologous blood plasma increased LDCL intensity. In the control (without gold nanoparticles), blood plasma produced no activating effect on LDCL. We found that the effect of gold nanoparticles on leukocyte LDCL depended on nanoparticle size: 10- and 30-nm nanoparticles inhibited LDCL intensity in comparison with the control (incubation in the absence of nanoparticles) irrespective of the duration of incubation, while 5-nm gold nanoparticles had no effect on LDCL intensity. Incubation of gold nanoparticles with autologous plasma increased LDCL intensity if nanoparticle size was 30 and 10 nm.

The dynamics of albumin transport function was studied during metal-catalyzed oxidation of albumin in diluted blood plasma from healthy donors and in the solution of purified albumin using fluorescent probe K-35. The changes were compared with the dynamics of free radical oxidation markers. For oxidation, different concentrations of Cu2+, Fe2+, Fe3+ ions as well as EDTA and H2O2 were used. Oxidative modification of proteins was assessed by carbonyl and bityrosine fluorescent products. Oxidation of plasma lipids was assessed by the levels of TBA-reactive products. It was found that oxidation markedly decreased effective concentration of albumin characterizing albumin binding capacity, and leads to accumulation of carbonyl products of protein oxidation, bityrosine fluorescent products in proteins, and TBA-active products of lipid oxidation. It was hypothesized that reduced effective concentration of albumin is related to impairment of its binding sites and/or accumulation of free-radical oxidation products filling the binding sites of albumin.

UNLABELLED Consistent neurohormonal activation of sympatho-adrenal system in patients with chronic heart failure (CHF) and hyperglycemia contributes to development of oxidative stress--one of the most important pathogenetic mechanisms of endothelial dysfunction. PURPOSE To study the impact of nebivolol concerning modification of clinical and hemodynamic indicators and parameters of oxidative stress in patients with CHF and with or without concomitant diabetes mellitus type 2 (DM2). MATERIAL Nebivolol was used in complex therapy of CHF in 82 patients, suffering from NYHA class I - III CHF (EF < 50%) of ischemic genesis with or without comorbid DM2, average age 63.2 +/- 8.2 years. RESULTS After 8 months of therapy significant improvement of clinical status was observed in both groups, tolerance to physical activity increased (significant reduction of average class of CHF in the group with DM2 from 2.5 +/- 0.58 to 2.125 +/- 0.71, p = 0.001, and in the second group from 2.3 +/- 0.5 to 1.9 +/- 0.4, p = 0.01). We also noted in both groups increase of plasma oxidative resistance (reduction of intensity of fast flash in lipid peroxidation h from 7 to 6 mm, p = 0.016, and from 8 to 6 mm, p = 0.03, respectively) and increase of antioxidant plasma protection (increase of SH-groups from 154.19 to 182.4 mmol/1, p = 0.00035, and from 176 to 205, p = 0.004, respectively). CONCLUSION Nebivolol is a modern neurohormonal modulator, which contributes to reverse evolution of oxidative changes in patients with CHF and hyperglycemia.

Oxidative stress plays an important role in cardiovascular diseases and atherosclerosis. Fibrinogen (FB), a central protein of the plasma coagulation cascade, is an independent risk factor of atherosclerosis. Importantly, it can be readily oxidized during oxidative stress and in various pathological conditions. Since endothelial dysfunction plays a key role in atherosclerosis it is interesting to investigate the effect of oxidized fibrinogen (ox-FB) on human umbilical vein endothelial cells (HEC). Here, we have investigated the effect of ox-FB on the development of programmed death of HEC incubated in vitro for 24 h under two different conditions: (1) at low serum level (0.1%) and in the absence of growth factors (“starvation”); (2) in full medium (5% human fetal serum) with growth factor supplement. Apoptosis was evaluated using analysis of nuclear morphology, phosphatidylserine externalization on the HEC surface and caspase-3 activation. Under starvation conditions characterized by significant cell death and activation of apoptosis addition of unoxidized FB significantly improved cell survival and prevented caspase-3/7 activation. In the presence of ox-FB caspase activity was 1.5 times higher than in the presence of FB, nevertheless, ox-FB demonstrated significant protection of HEC. Under optimal cultivation conditions FB caused a 3-fold decrease in the rate of apoptosis, while ox-FB improved cell survival but it was less active than FB. Thus, FB promoted HEC survival under stress conditions (in starvation), however, oxidative modification of this protein decreased its antiapoptotic activity.

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Recent studies showed that activation of free oxygen radicals and the resulting stress play a key role in the development of brain vascular lesions related to hypertensive disease and atherosclerosis leading to chronic cerebral ischemia. To recall, activation of oxidative stress precedes chronic cerebral ischemia and stroke. Therefore, detection of stress markers may be a step toward the development of a new method for the identification of groups at high risk of stroke among patients with the unfavourable course of cerebral ischemia. This study was focused on the relationship between lipid and protein peroxidation products and clinical manifestations of the disease.

Regularities of changes in resonance light scattering spectra of silver nanoparticles due to their interactions with protein molecules are studied. This effect can be used to identify biological molecules and elucidate their modification, in particular those due to oxidative processes, using optical techniques.

The aim of the work was to evaluate the diagnostic and prognostic value of the characteristics of processes involving free radicals and of high-performance ECG (hpECG) in patients with coronary heart disease (CHD). A new method for early assessment of the severity of myocardial ischemia and its electric remodelling was developed. Malonic dialdehyde levels (MDA) following Cu-induced oxidation during 24 hr were shown to correlate with clinical features of CHD (functional class of angina, hpECG patterns). hpECG characteristics changed parallel to MDA levels, their frequency was related to the severity of CHD. Long-term prognosis of unstable angina (12 month follow-up) was aggravated in patients with MDA level of 100 nmol/ml. MDA concentration and its dynamics correlated with CHD severity and outcome of acute coronary syndrome (ACS): non-Q wave myocardial infarction and angina. All patients with ACS underwent its exacerbation within 5-7 days and had depleted plasma antioxidative system. MDA and hpECG dynamics can be used to evaluate ACS severity and prognosis as a new diagnostic approach to identifying CHD patients with the expected unfavourable outcome of the disease.

Changes in the capacity of fibrinogen subjected to oxidative modification to transform into fibrin under the effect of thrombin and to form a fibrin clot were studied. The effects of oxidized fibrinogen preparations on the clot formation by citrate-treated donor plasma were evaluated by the thrombin time test. Oxidation impaired the capacity of isolated fibrinogen to form a fibrin clot under the effect of thrombin. Addition of oxidized fibrinogen solutions to donor plasma led to prolongation of the plasma clotting time. Maximum addition (33% volume) of oxidized fibrinogen led to a 10-26% prolongation of clotting time in comparison with addition of the same volume of the same solution without fibrinogen.

Turbidimetry studies showed that after addition of thrombin to fresh donor plasma light scatter in the sample increases and slowly attains a plateau. The process of fibrin formation was less intensive in the presence of oxidized fibrinogen. The formation of fibrin clot in lyophilized plasma was characterized by a biphasic kinetic of light scatter, oxidized fibrinogen inhibited both phases of the process. In the presence of streptokinase, oxidized fibrinogen did not modify the kinetics of fibrin clot lysis. Addition of oxidized fibrinogen to plasma reduced optical density of fibrin clot the more intensely the higher was the degree of oxidative modification of fibrinogen.

The kinetics of thrombin inhibition by irons ions was studied in the thrombin time test with normal plasma. The kinetic and concentration characteristics for recovery of thrombin activity by desferal were evaluated at various periods of thrombin incubation with iron ions. The thrombin time test showed that incubation of thrombin with iron sulfate in a final concentration of 200 μM for 25–35 min is followed by the loss of thrombin activity. Pretreatment of iron-containing incubation system with desferal was shown to decelerate the process of thrombin inactivation. The kinetic characteristics for recovery of thrombin activity by 2 mM desferal were estimated at various periods after addition of iron sulfate in the inhibitory dose. The effect of reversibility was shown to depend on the time of thrombin preincubation with iron. Incomplete recovery of thrombin activity after increasing the time of incubation with iron (more than 30 min) was probably related to oxidative modifi cation of thrombin.

The effect of oxidized fibrinogen on platelet-neutrophil complex formation was evaluated by studying the platelet aggregation (changes in light transmission and turbidimetric assay). Activation of cells by thrombin (0.015 U/ml) in the presence of oxidized fibrinogen was accompanied by the formation of larger intermolecular aggregates of platelets and leukocytes as compared to those detected in experiments with non-oxidized fibrinogen. Addition of thrombin (0.2 U/ml) in the presence of oxidized fibrinogen was followed by the formation of more stable complexes of platelets and leukocytes as compared to those revealed in experiments with non-oxidized fibrinogen. An increase in the width of aggregation curves was most pronounced in the system of 10−4 M Fe2+ and 10−4 M H2O2 with oxidized fibrinogen. Our results indicate that oxidized fibrinogen contributes to the “floating” or suspension of platelet-leukocyte complexes.