Effects of gold nanoparticles on erythrocyte hemolysis.

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.

Effect of gold nanoparticles on production of reactive oxygen species by human peripheral blood leukocytes stimulated with opsonized zymosan.

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.

Effect of gold nanoparticles coated with plasma components on ADP-induced platelet aggregation.

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.

Relationship between parameters of lipid peroxidation during obstructive jaundice and after bile flow restoration.

Restoration of bile flow after 9-day cholestasis in rat liver normalized the content of lipid peroxidation products. The removal of the cholestatic factor after 12-day cholestasis was not followed by recovery of these parameters. We showed that measurement of serum concentration of lipid peroxidation products in patients with cholelithiasis during the preoperative period holds promise for selection of the optimum time for surgical treatment and prediction of the risk of postoperative complications.

Primary biliary cirrhosis and coronary atherosclerosis: protective antioxidant effect of bilirubin.

Increased concentration of lipid peroxidation products in patients with primary biliary cirrhosis is related to elevation of serum lipid content, but not to activation of lipid peroxidation. Hyperbilirubinemia in patients with primary biliary cirrhosis is accompanied by a decrease in the concentration of lipid peroxidation products and increase in antioxidant activity of blood serum. Antioxidants play a major role in the prevention of atherosclerosis.

[Relationship of tumor necrosis factor alpha expression with activation of sphingomyelinase and lipid peroxidation after removal of cholestatic factor].

The goal of this work was to study the expression of tumor necrosis factor alpha (TNFalpha), sphingomyelin cycle activation, and lipid peroxidation (LPO) processes after the removal of a cholestatic factor in the liver subjected to different durations of cholestasis. Restored bile flow after a 9-day hepatic cholestasis normalized sphingomyelinase (SMase) activity and levels of TNFalpha and LPO products. The removal of a cholestatic factor after a 12-day cholestasis did not normalize the studied parameters: SMase activity and the levels of TNFalpha and LPO products remained much higher compared to control.

[Changes in sphingomyelinase activity, tumor necrosis factor alpha level, and lipid peroxidation rate in the course of development of cholestatic liver injury].

Changes in sphingomyelinase activity, tumor necrosis factor alpha expression, and lipid peroxidation rate in the course of development of cholestatic liver injury have been studied. The same type phase shifts in the parameters analyzed were observed, which included a marked decrease at the early stages of cholestasis (days 3-6) and a pronounced increase at the later stages (days 12-16), i.e.

The relation between sphingomyelinase activity, lipid peroxide oxidation and NO-releasing in mice liver and brain.

We used animal models to study connection between oxidating system and sphingomyelin signaling cascade, because this models are more close related to people disease. Activation of n-sphingomyelinase (n-SMase) in mice liver and brain is coincided in time with increased level of peroxide products (conjugated dienes) after injection of tumor necrosis factor alpha (TNF-alpha). We found that ceramide can induce peroxide oxidation and lead to accumulation of TNF-alpha in animal organs.

[Kinetic characteristics of Cu2+-induced lipid peroxidation in blood plasma and serum].

The aim of this study was to determine the concentration parameters and time-course of copper-induced oxidation in serum and whole blood plasma. We investigated the oxidizability of undiluted and (2-60-fold) diluted whole plasma (prepared with citrate as an anticoagulant) and serum by monitoring the change in the level of conjugated dienes, ketodienes and malondialdehyde in the samples. The kinetic curves of the accumulation of different lipid peroxidation (LPO) products had similar S-shape, but they differed by a number of quantitative parameters--lag-time, time of improvement and the level of maximal rate of oxidation, as well as time of improvement of the maximal accumulation and maximal amount of LPO products.

[Plasma lipids oxidation in patients with occlusive atherosclerosis of lower extremities and ischemic heart disease].

Dynamics of lipoprotein oxidation in blood plasma was studied by Cu-induced plasma oxidation in 114 patients with atherosclerosis of lower extremities of various severity with and without ischemic heart disease. Preparedness of plasma lipoproteins to oxidation in patients was higher than in healthy subjects. Degree of oxidizeability increased with increase of severity and extent of atherosclerosis and was highest in patients with atherosclerosis of lower extremities and ischemic heart disease.

[The influence of tumor necrosis factor alpha on the processes of sphingomyelin cycle and lipid peroxidation in brain].

The influence of tumor necrosis factor alpha (TNF-alpha) on the processes of sphingomyelin cycle activation and intensity of peroxidation in animal brain in vivo has been studied. Alterations in activity of sphingomyelinase, a key sphingomyelin cycle enzyme and in sphingomyelin, ceramide content as well as accumulation of the products of lipid peroxidation (diene conjugates and diene ketons) were measured in the cortex, the cerebellum and the hippocampus of rats 5, 15, 30 min, 1, 2 and 5 hours after TNF-alpha intraperitoneal injection in dosage 100 mkg per animal. It is shown that 2 hours after the injection, TNF-alpha initiated an accumulation of the products of lipid peroxidation, which intensively developed in the cerebellum and the hippocampus.

Connection of lipid peroxide oxidation with the sphingomyelin pathway in the development of Alzheimer's disease.

Alzheimer's disease (AD) is characterized by progressive decline in cognition, memory and intellect. It has been hypothesized that amyloid-beta peptide (A-beta) may have a prominent role in neurodegeneration. Oxidative mechanisms have been implicated in this pathway.

Effects of fibrinogen on lipid peroxidation in patients with coronary heart disease and in vitro.

In patients with coronary heart disease oxidizability of lipids during Cu(2+)-induced oxidation of blood plasma inversely correlated with fibrinogen content. A positive correlation was found between the amount of lipid peroxidation products in the plasma from these patients and fibrinogen content. The increase in fibrinogen content was associated with high levels of total lipids and triglycerides and low concentration of high-density lipoprotein cholesterol.

Role of tumor necrosis factor alpha and sphingomyelin cycle activation in the induction of apoptosis by ischemia/reperfusion of the liver.

The signal transduction pathways triggering apoptotic mechanisms after ischemia/reperfusion may involve TNF-alpha secretion, ceramide generation, and initiation of lipid peroxidation. In the present study involvement of the TNF-alpha, sphingomyelin cycle, and lipid peroxidation in the initiation of apoptosis induced in liver cells by ischemia and reperfusion was investigated. Wistar rats were subjected to total liver ischemia (for 15, 30 min, and 1 h) followed by subsequent reperfusion.

Effects of reduced and oxidized glutathione on sphingomyelinase activity and contents of sphingomyelin and lipid peroxidation products in murine liver.

Like the phosphatidyl inositol cycle, the sphingomyelin cycle produces a series of the secondary messengers transmitting extracellular signals from the cytoplasmic membrane into the nucleus. Sphingomyelin, ceramide, sphingosine, sphingomyelinase, and ceramidase are the main components of the sphingomyelin cycle. In spite of numerous data on the functional properties of sphingomyelin cycle products, the activation mechanism for the key enzyme of the sphingomyelin cycle, sphingomyelinase (SMase), is not well understood.

Effect of bilirubin on lipid peroxidation, sphingomyelinase activity, and apoptosis induced by sphingosine and UV irradiation.

The effect of bilirubin (BR) on sphingomyelin cycle activity, lipid peroxidation (LPO), and apoptosis induced by sphingosine and UV irradiation has been studied in vivo. Neutral Mg(2+)-dependent sphingomyelinase (SMase) activity and LPO level were monitored in heart, kidney, and liver of mice after administration of BR. BR inhibited both LPO and SMase activities in heart and kidney.

[Correlation between severity of angina, its stability, and oxidative modification of lipids in patients with ischemic heart disease].

Aim: To elucidate the relations between angina severity, stability, concomitant arterial hypertension, diabetes mellitus, plasma oxidation.

Material And Methods: The study included 152 patients with stable angina of effort (functional class II-III). Of them, 67 had concomitant arterial hypertension (AH), 20 AH and compensated diabetes mellitus type II, 14 patients with anginal functional class III were admitted to hospital for unstable angina, 11 patients with IHD with unstable angina and 28 healthy donors.

[Lipid peroxidation and its connection with the change in composition and antioxidant properties of lipids in comatogenic forms of acute viral hepatitis B].

81 patients of acute viral hepatitis B (AVHB) without symptoms of acute hepatic encephalopathy, 39 AVHB patients with such symptoms and 115 age and sex match healthy controls were biochemically and clinically investigated. Besides usual biochemical analyses, some special parameters such as interrelationship between the patterns of lipid peroxidation (LPO) (conjugated dienes and ketodienes and the lipid antioxidant activity) and alterations in lipid composition (content of total lipids, phospholipids and cholesterol) were studied in blood serum. Concentration of LPO products in patients with mild, moderate and severe AVHB without symptoms of encephalopathy was found to be significantly lower than in controls.

Sphingolipids of transplantable rat nephroma-RA.

Contents of sphingolipids (ceramide, sphingomyelin, gangliosides) and the composition of their sphingoid bases were studied in the transplantable rat nephroma-RA and in rat kidneys. The content of sphingomyelin was about 1.3-fold decreased and the content of ceramide was about 1.

[Changes in the activity of neutral and acidic isoforms of sphingomyelinase in hepatoma-22, regenerating and ischemic liver].

Activity of neutral and acidic sphingomyelinases (N- and A-SMases) were studied in regenerating liver after partial hepatectomy (during 48 hrs after operation), in ischemic liver during 15, 30 min and 1 and 2 hrs ischemia and during following reperfusion (from 5 min up to 2 hrs), in hepatoma- 22 after 15 days of transplantation and in liver of tumor bearing animals. It was shown that activity of N-SMase is increased in hepatoma-22 and in regenerating liver and it is decreased in ischemic liver. Following reperfusion of ischemic liver area activity of enzyme was found to have returned to baseline in dependence on time of ischemia and reperfusion.

[Intensification of serum lipid peroxidationas a biochemical marker of concomitant pancreatitis in complicated gallstone disease].

Serum concentration of two products lipid peroxidation (LPO) of--conjugated dienes and dienketones--was assessed in 71 patients with exacerbation and remission of chronic pancreatitis, uncomplicated gallstone disease and with combinated pathology of pancreas and biliary tracts and in 100 healthy persons. During exacerbation of pathologic process in pancreas with the different ethiology of disease strong intensification of LPO occurs, but in period of remission LPO markers were found to be close to those in control. Postoperative complications and severe outcome in patients with gallstone disease are associated with a significant increase in LPO level in serum before reoperation.

Content and structure of ceramide and sphingomyelin and sphingomyelinase activity in mouse hepatoma-22.

The relative content of phosphatidylcholine is lower and that of sphingomyelin is higher in transplantable fast growing mouse hepatoma-22, thus decreasing their ratio approximately 2.5-fold versus normal liver. The ceramide content and the neutral sphingomyelinase activity is markedly higher (3- and 6.

Characterization of bilirubin inhibitory properties in free radical oxidation reactions.

The rate constant of the reaction between bilirubin (BR), the end product of heme catabolism, and alkylperoxyl radical was estimated by the chemiluminescence method in the model reaction of ethyl benzene induced oxidation. The constant was determined to be 1.5.