The effect of a mesenchymal stem cell conditioned medium fraction on morphological characteristics of hepatocytes in acetaminophen-induced acute liver failure: a preliminary study.

In our studies, it was shown that the effectiveness of the conditioned medium obtained by cultivating mesenchymal stem cells depends on the microenvironment conditions used to cultivate the cells. It was demonstrated that the conditioned medium obtained by culturing cells with low oxygen content (10%) has a much more pronounced protective effect. Protein compositions obtained from MSCs cultured under hypoxic (10% O hc-MSC) and normal (21% O nc-MSC) conditions were used to treat acute liver failure (ALF) induced in mice by acetaminophen injection.

Protective properties of the cultured stem cell proteome studied in an animal model of acetaminophen-induced acute liver failure.

Chronic overuse of common pharmaceuticals, e.g. acetaminophen (paracetamol), often leads to the development of acute liver failure (ALF).

Effect of Conditioned Medium and Bone Marrow Stem Cell Lysate on the Course of Acetaminophen-Induced Liver Failure.

A composition containing culture medium conditioned by mesenchymal stem cells and mesenchymal stem cell lysate improves biochemical parameters, reduces inflammation, and stimulates regenerative processes in the liver.

Paracrine mechanisms of proliferative, anti-apoptotic and anti-inflammatory effects of mesenchymal stromal cells in models of acute organ injury.

The purpose of this review is to systematize data from many studies and observations of proliferative, anti-apoptotic and anti-inflammatory effects of mesenchymal stromal cell (MSC) paracrine factors and their biologic effects in models of acute organ injury.

[Blood plasma protein adsorption capacity of perfluorocarbon emulsion stabilized by proxanol 268 (in vitro and in vivo studies)].

The adsorption abilities of the perfluorocarbon emulsion stabilized by Proxanol 268 were investigated in vitro and in vivo. In vitro, the saturation point for the blood plasma proteins was nearly reached after five minutes of incubation of the emulsion with human/rabbit blood plasma and was stable for all incubation periods studied. The decrease in volume ratio (emulsion/plasma) was accompanied by the increase in the adsorptive capacity of the emulsion with maximal values at 1/10 (3.

[Mechanisms of human plasma proteins adsorption on the surface of perfluorocarbon emulsion stabilized with proxanol 268].

It has been shown that sorption of most proteins with the molecular weight lower than 200 kDa from human blood plasma on the surface of perfluorocarbon emulsion, stabilized with proxanol 268, is mainly based on hydrophobic interaction, whereas sorption of immunoglobulin G is mainly the result of electrostatic interaction. The removal of lipidic components from plasma leads to the increase of a total amount of adsorbed proteins by 35%. Particularly, when lipidic components are removed, sorption of apolipoprotein AI and immunoglobulin G is considerably bettered as well as sorption of other proteins with the molecular weight of about 50 and 60 kDa occurs.

[Use of perfluorocarbon emulsions for administration of photosensitizing preparations into bone marrow stem cells].

It has been shown that, upon incubation of mouse bone marrow stem cells (BMSC) in vitro with the nanoparticles of perfluorocarbon (PFC) emulsion stabilized by proxanol 268, these nanoparticles penetrate into cells and stay there for a long time (up to 20 days of observation). It has been found that, under in vitro conditions, mouse BMSC loaded with the nanoparticles of both the original emulsion and the emulsion preliminarily incubated with radachlorine do not differ from control stem cells in the rate of division, stretching on a plastic support, and the formation of a monolayer. It has been shown that the exposure to laser radiation of BMSC incubated with the nanoparticles of a PFC emulsion preliminarily incubated with radachlorine under in vitro conditions leads to the death of these cells due to the destruction of the cell membrane.

[Dynamics of a vortex with the U-shaped filament in the heart of a ground squirrel].

The dynamics of an electrical scroll wave with the U-shaped filament with both ends of the filament being "anchored" on the endocardial surface and the dependence of the structure of pseudoECG on the dynamics of the vortex during the development of polymorphic tachysystolia have been studied by applying premature stimuli to the "target phase" with subsequent registration of the spatial and temporal distribution of electrical potential throughout the surface (endocardial and epicardial) of a thin (approximately 1 mm) preparation. It was found that (1) the psedoECG of the polymorphic form during the tachysystolia attack can be observed in the case that the position of the filament ends on the surfaces of the preparation does not practically change from turn to turn (filament ends are "anchored"); (2) the thread of a scroll wave during this attack can twist and untwin (twisted filament), just as it was the case for scroll waves with a straight filament; (3) in the case of pseudoECG of polymorphic form, the twisting and untwining of the filament were stronger (the angle of maximal twisting was 120 degrees and more), and the angle of twisting changed by a substantially greater value from turn to turn as compared with the pseudoECG of monomorphic form; (4) in the case of pseudoECG of polymorphic form, the time interval between the appearance of waves on the surfaces of the preparation (Tepi-endo) was substantially greater and changed to a greater extent from turn to turn of the vortex; and (5) simultaneously with the appearance of pseudoECG of polymorphic form and the onset of changes in the twisting of the scroll and the Tepi-endo interval indicated in (2-4), significant changes in the patterns of coverage of the surface by excitation occurred. Based on the results obtained, an explanation of the reasons for the appearance of excitation breakdown patterns on the surface of the myocardium was proposed, which differs from the traditional viewpoint.

[Sorption of plasma proteins by fluorocarbon emulsions stabilized by various surfactants].

It has been found in in vivo and in vitro experiments that, as a perfluorocarbon emulsion stabilized by Proxanol 268 comes in contact with blood plasma proteins, plasma proteins with molecular masses from 25 to 170 kDa and above are adsorbed on the surface of emulsion particles. Among the adsorbed proteins, fibronectin and fibrinogen were identified by immunoblotting. In in vivo experiments, during circulation in the blood flow, considerable amounts of plasma proteins are adsorbed on Proxanol-stabilized emulsion particles; the amount of adsorbed proteins increases with the time the particles are in the blood flow.

[An emulsion based on 1-bromoperfluorooctane: X-ray contrast properties and mechanisms of X-ray contrasting].

It has been shown that the emulsion of a mixture of the perfluorocarbons 1-bromoperfluorooctane and perfluoro[1-(4-methylcyclohexyl)piperidine], stabilized by egg yolk phospholipids, makes it possible to contrast rapidly (beginning with the 10th minute) and for a long time (up to 5 days) the tissues of various organs, such as liver, spleen, adrenal glands, heart, and the peritoneal part of the aorta. The roentgenograms of rat organs in in vivo experiments were evaluated by computer-assisted morphodensitometry. The contrasting of organs at early terms of the circulation of emulsion in the body is related to a high concentration of 1-bromoperfluorooctane in the blood flow, and the contrasting at later terms is related to the accumulation of emulsion particles by cells of the reticuloendothelial system.

[Effect of perfluorocarbon emulsions on function of enzyme systems responsible for generating active forms of oxygen in neutrophils].

The ability of the emulsion of perfluoroorganic compounds stabilized with proxanol 268 to affect the functions of peritoneal neutrophils was evaluated. The functional activity of neutrophils was estimated from the intensity of generation of reactive oxygen species using the method of chemiluminescent analysis. The emulsion was shown to suppress the neutrophil responses to phorbol-12-myristate-13-acetate in a dose-dependent manner.

[Radiocontrast properties of the emulsion of the perfluoroorganic compound lipobrom].

X-ray contrast properties of the new perfluoroorganic emulsion lipobrom were studied in comparison to those of a traditional clinical Roentgen diagnostic agents omnnipaque and ultravist and the well-known blood substitute perftoran. The x-ray patterns were evaluated by a computer morphodensitometry technique.

[Sorption of plasma components on the surface of particles of fluorocarbon emulsions stabilized by proxanol 268].

It was found in the experiments in vivo and in vitro that the contact of perfluorocarbon emulsion stabilized with proxanol 268 with blood plasma leads to the sorption of various plasma proteins on the surface of emulsion particles. The profile of the proteins sorbed is complex and includes proteins with molecular weights ranging from 14 to 94 kDa. Among proteins sorbed on the emulsion particles circulating in blood, IgG was identified.

[Mechanisms of distribution and elimination of perfluorocarbons upon multiple exposures].

In clinical practice much more often one meets a necessity of repeated administration of fluorocarbon blood substitutes. The 19F(-)-NMR-spectroscopy has been used to study the kinetics of the blood and tissue fluorocarbon concentration after repeated administration of PFC emulsion. Analysis of the data suggests that redistribution of PFCs between organs and blood after their repeated administration is under control of Ostwald ripening depending on PFC physicochemical properties (water and lipid solubility), emulsion particle diameter etc and does not connect with activity of reticuloendothelial system.

[Perfluorocarbon emulsions and other corpuscular systems influence on neutrophil activity].

Influence of perfluorodecalin, perfluoromethilcyclohexylpiperidine, perfluorotributylamine emulsions on active oxygen form (AOF) generation by neutrophils has been studied. All investigated emulsions stabilized both proxanol 268 and egg yolk phospholipids inhibited PMA-stimulated neutrophil activity. Castor oil emulsion also inhibited the neutrophil activity.

[Uncoupling of the liver monooxygenase system by perfluorocarbons in vivo].

Administration of a perfluorodecalin (PFD) emulsion, the liver cytochrome P-450 II B1/B2 inducer, to experimental animals is followed by a two-fold increase of the NADPH oxidation rate in liver microsomes. This phenomenon is caused by the presence in the cytochrome P-450 active center of PFD which uncouples microsomal hydroxylation. The high rate of NADPH oxidation in liver microsomes after administration of the fluorocarbon does not decrease the level of reduced pyridine nucleotides in the liver and does not change the glucose concentration in the plasma.

[Biophysical mechanisms of toxicity of fluorocarbon emulsions].

Intravenous administration of emulsions of some perfluorochemicals (PFCs) are followed by lung gas-exchange alterations, lung inflation and animal death. The emulsion toxicity can be caused by both low aggregation stability of the emulsion in the blood stream and appearance of the additional gas pressure in alveoli as a result of difference in the rates of alveolar gas and PFC vapor diffusion. Theoretical and experimental analysis shows that (1) absence of emulsion particle aggregation into blood stream, (2) low pressure of saturated vapors of PFC phase and (3) relatively low rate of PFC expiration from the organism are essential conditions for the creation of a safe fluorocarbon blood substitutes.

[Interaction of perfluoroctylbromide with liver microsomal monooxygenase].

Perfluorooctylbromide (PFOB), a constituent component of gas-transporting fluorocarbon emulsions, liberates bromide ions when PFOB undergoes NADPH-dependent metabolism by liver microsomal monooxygenase. The PFOB emulsion injected to rats decreases the liver microsomal cytochrome P-450 level down to 80% of control. Induction of the "phenobarbital" isoforms of cytochrome P-450 (cytochrome P-450 II B1/B2) after administration of PFOB is much weaker than that after administration of the perfluorodecalin emulsion.

[A new model describing the isolation of fluorocarbons from an organism: dissolution of fluorocarbons in the lipid components of blood].

Perfluorodecalin (PFD), intravenously administrated to rabbits in the form of submicron emulsion, quickly disappears from the blood stream and accumulates in the liver, spleen and bone marrow. The expiration rate of PFD from the body can be significantly enhanced by intravenous administration of sunflower oil emulsion. It is supposed that the limit stage of PFD excretion is a fluorocarbon transport from accumulatory organs to the lungs by lipid carriers (lipoproteins, chylomicrons and cell membranes) in which fluorocarbons are physically dissolved.

[Characteristics of enzyme induction in the liver monooxygenase system of rabbits intravenously administered a fluorocarbon emulsion].

Intravenous injections to rabbits of perfluorocarbon emulsion containing perfluorodecaline (10 ml/kg, equivalent to 1.3 g of perfluorodecaline per 1 kg of body weight) produced a 2-4-fold increase of cytochrome P-450 content in the liver microsomes within 3-4 weeks. Cytochrome P-450 induction was followed by activation of the liver monoxygenase system evaluated by the rate of antipyrine excretion from the blood.

[Analysis of the physico-chemical properties of fluorocarbon inducers of cytochrome P-450 in membranes of liver endoplasmic reticulum].

Cytochrome P-450 induction in rat liver microsomes after intravenous injections of submicrone emulsions of nine perfluorochemicals (2 g of PFC per kg of body weight) was investigated. A comparison of physico-chemical properties of the fluorocarbons revealed that their activity as cytochrome P-450 inducers is determined by their solubility in H2O and lipids as well as by the pressure of their saturated vapours at 37 degrees C. The fluorocarbons capable of inducing cytochrome P-450 have a molecular mass of 400-550 Da.

Use of tetramethylammonium hydroxide to determine the total fatty acid composition of microorganisms.

A destructive chromatographic method of identifying microorganisms is described. The method is based on hydrolysis of the biomass of the microorganisms in the presence of tetramethylammonium hydroxide, followed by introduction of the hydrolyzate into the heated injector of a gas chromatograph. The main products in this case are methyl esters of fatty acids, the composition of which is used as a diagnostic criterion.