[A new class of phenomena identified during the analysis of neural network of multidimensional data from patients with inflammatory lung diseases].

Aim: To apply the neural network analysis method of multi-data of patients with community-acquired pneumonia (CAP) to recognize the variability of their diagnoses and discovery of new analytical capabilities of NSA based on new methodological approaches of the meeting.

Materials And Methods: In this paper, we applied a new approach of neural network analysis of multivariate data, obtained based on clinical, laboratory and instrumental tests in 60 patients older than 65 years at various stages of the treatment of community-acquired pneumonia. Anthropometric data were used together with the results of immunological and immunochemical studies of blood serum of patients with community-acquired pneumonia who were in the acute phase of the disease.

[Detection of nitrite and nitrosocompounds in chemical systems and biological liquids by the calorimetric method].

The capacity of nitrite, S-nitrosothiols (RS-NO), dinitrosyl iron complexes (DNICs) with thiol-containing ligands, and nitrosoamines to inhibit catalase has been used for the selective determination of these compounds in purely chemical systems and biological liquids: cow milk and colostram. The limiting sensitivity of the method is 50 nM. A comparison of the results of the determinations of RS-NO, DNIC, and nitrite by the catalase method and the Greese method conventionally used for nitrite detection showed that, firstly, Greese reagents decompose DNIC and RS-NO to form nitrite.

[An enzymatic sensor for estimation of the content of nitro and nitroso compounds in biological objects].

Nitric oxide (NO) generation in the biological cells and tissues is a cause of the production of some nitro and nitroso compounds that differ in their physiological significance and toxicity. The resultant problem in the estimation of the content of all nitro and nitroso compounds totally and singly in complex systems, such as biological objects, remains to be very urgent since simple, highly sensitive and highly selective methods have not been proposed so far to determine all these NO derivatives. The method based on some specific biochemical property of NO metabolites, which manifests itself under physiological conditions and permits the fixation of all nitro and nitroso compounds without their prior modification fraught with unpredictable artifacts, seems to be optimal.

[The role of the nervous factor in regulation of oxygen supply to the small intestine].

The experimental model of rat bilateral subdiaphragmatic stem vagotomy was used to study the role of parasympathetic nervous system in regulation of circulation and oxygen supply to the small intestine. Cut of the vagus nerves is shown to cause redistribution of the blood flow between gastroduodenal organs, to slow down local circulation, to reduce oxygen tension in the muscular lining of the jejunum, to raise water content in the wall and change magnetorelaxational characteristics. Morphologically this manifested in altered arteriolar and capillary configuration, dilation of the capacity microvessels, dystrophia of microvessel wall, red cell aggregation in capillaries and venules, defective permeability of the vascular wall.

[Inhibitory effects of serotonin and sodium ascorbate on the oxidative aggregation of lipoproteins].

Milk lipoproteins (MLPs) are structurally and biochemically similar to blood lipoproteins, which allow the former to be used as model objects for studying the properties of the latter. The results of turbidimetric measurements showed a change in the light scattering from MLP suspensions upon contact with Fe3+ ions in the free from or in chelate complexes with o-phenanthroline and EDTA. No such effect was observed for Fe2+ ions.

[Oxidative destruction of estradiol after treatment with hydrogen peroxide catalyzed by horseradish peroxidase and methemoglobin].

It is shown that estradiol in the presence of horse radish peroxidase interacts with hydrogen peroxide, which is evidenced by an increase in its optical density at 280 nm. The photometering of samples containing estradiol and horse radish peroxidase upon their titration with hydrogen peroxide indicated that the increase in optical density stops after introducing hydrogen peroxide equimolar in concentration to estradiol. The stoichiometric ratio of estradiol consumed during oxidative destruction to hydrogen peroxide was 1:1.

[A new property of aspirin and other salicylates. Their capacity for radical generation at the expense of chelating-oxidizing action on iron cations].

It was demonstrated that salicylic acid, by binding ions of ferrous iron, induces its oxidation to the oxide form by molecular oxygen with generation of active forms of oxygen. Salicylic acid may therefore form stable ferrosalicylic complexes only with iron oxide, in which case the affinity of salicylic acid for iron oxide is higher than that of o-phenanthroline and lower than that of EDTA. In the presence of ascorbate in the system with salicylic acid and iron ions continuous radical formation may take place due to alternating cycles of oxidation-reduction iron ions through the combined effect of salicylic acid and ascorbate on them.

[Chelating and oxidizing properties of tetracycline metabolites forming during its peroxidase or photoinduced oxidation].

Tetracycline metabolites forming on the antibiotic exposure to visible light or peroxidase as well as tetracycline as such showed the ability to bind iron cations. When the metabolites bound the cations of iron protoxide, they catalyzed its oxidation. Chelating agents such as o-phenanthroline and EDTA arrested the ions of iron protoxide and iron oxide in the respective iron/tetracycline complexes at a much lower rate than that with the use of the native tetracycline.

[Metabolites of tetracycline obtained during its irradiation with visible light or peroxidase oxidation. Their toxic properties in relation to hemoglobin].

It was indicated in the literature that when exposed to visible light tetracycline induced phototoxic effects with respect to heme-containing proteins. The present study showed that when tetracycline was exposed to visible light it formed metabolites due to the photochemical transformations, the metabolites formation being slightly affected by the anti-radical drugs such as L-histidine, mannitol, ethanol and catalase. The investigation of the conditions of the metabolites formation as a result of the photochemical transformations revealed a specific role of ascorbate in the process.

[The property of tetracyclines to induce methemoglobin formation in erythrocytes and to inactivate catalase when exposed to radiation in the visible range].

When tetracycline and chlortetracycline were incubated an a dark room in the presence of erythrocytes with erythrocytic catalase completely inactivated by sodium azide, the antibiotics induced methemoglobin formation in them. If the catalase was not inactivated, no such phenomenon was observed. This meant that after the penetration into the erythrocytes the tetracyclines induced in them the generation of hydrogen peroxide which was the immediate cause of the methemoglobin formation.

[Metabolic transformation of antibiotics of the tetracycline series in peroxidase reactions].

In was shown calorimetrically that in the presence of horse radish peroxidase tetracyclines induced degradation of hydrogen peroxide. Under such conditions changes in the tetracycline optical properties were detected photometrically. It was concluded that tetracyclines were metabolized in the peroxidase reactions catalyzed by horse radish peroxidase as their substrates.

[A new view of estradiol biotransformation in the body. Estradiol metabolism in the erythrocytes via the peroxidase reaction].

The study has established that in the presence of horseradish peroxidase, estradiol was subject to oxidative destruction under the action of hydrogen peroxide via the peroxidase reaction. The stoichiometric ratio of the hydrogen peroxide consumption to estradiol oxidation is 1:1 in this peroxidase reaction. Estradiol peroxidation was found to be catalyzed by methemoglobin by the same order as in case of horseradish peroxidase.

[A new look at the mechanism of action of antibiotics of the tetracycline series. Tetracyclines as components of radical-generating systems].

Tetracyclines were shown to be able to form radical-generating systems and to affect biological structures at the account of the radical form generation. The radical-generating systems were found to be based on the phenomenon revealed in this study that the tetracyclines catalyzed oxidation of ferrous oxide by oxygen after its binding by these compounds. In the presence of ascorbate the radical formation with the involvement of oxygen could be continuous and accompanied by reduction of ferrous oxide by ascorbate in complex with tetracyclines and its subsequent oxidation as well induced by them.

[Change in various properties of catalase in the small intestine of rats after vagotomy].

To evaluate the antioxidative system of the small intestine in disturbed parasympathetic innervation, the authors studied the activity of catalase, its resistance to substrate inactivation (catalytic capacity) and reduction potential (reduction of Fe3+ to Fe2+) in the enteric homogenate in different periods (on day 14 and 30) after bilateral subdiaphragmatic truncal vagotomy. Vagotomy did not change catalase activity but was attended by an increase of catalase catalytic capacity and reduction potential. It is suggested that the discovered changes of the studied parameters are manifestations of responses of the antioxidative protective system of the small intestine to the activation of lipid peroxidation.

[Mechanism of oxyhemoglobin oxidation induced by hydrogen peroxide].

The process of oxyhemoglobin oxidation initiated by hydrogen peroxide in low (10(-7) M) concentrations was investigated. It was found, that H2O2 in this concentration is able to induce the process of chain oxidation of oxyhemoglobin to methemoglobin. The following observations indicate that the process is essentially the chain reaction: 1) The amount of the methemoglobin in haem groups, produced in the reaction, exceed by 20 times the quantity of hydrogen, added initially, to induce the oxidation.

[Mechanical properties of the small intestine of rats in the normal state and after disturbed parasympathetic innervation].

In intact and vagotomized (in 14 and 30 days after the operation) rats by means of the dynamometric method values of maximal load and relative maximum elongation of the proximal and middle areas of the small intestine (SI) have been determined in vitro. Dependence of relative elongation of the SI fragments on the load applied has been investigated. The proximal part of the SI is the most firm to tearing in comparison to the middle one.

[Changes in erythrocyte size during swelling in hypo-osmotic media].

Swelling of erythrocytes in hypotonic media was considered. Taking into account the presence of surface rigidity in erythrocyte membranes an equation is proposed which describes a relationship between erythrocyte sizes and osmolarity of the suspension medium. Calculations carried out on the basis of this equation show that in the experiments when osmotic resistance of erythrocytes is estimated the mechanical properties of erythrocyte membranes are largely manifested.

[Effect of antioxidants on the HeLa cell infection process in culture].

A certain role in the outcome of virus infection of cells was assumed to belong to cell membrane lipids peroxidation. The influence of known inhibitors of lipid peroxidation, beta-naphthol and ionol, on HeLa cells infection with human adenovirus type 2 was studied. These antioxidants in certain concentrations were found to be capable of effectively inhibiting virus infection of HeLa cell cultures.

[Shifts in the antioxidant activity in the membrane structures of virus-infected cells].

It is assumed that the process of virus infection of cells causes significant changes in the conditions of lipid peroxidation in membrane structures of such cells. Experiments with virus-infected HeLa cells demonstrated noticeable decrease in the capacity of membrane lipids for peroxidation induced by ultraviolet irradiation and iron monoxide ions. Similar changes were also observed in membranes of chick embryo liver cells infected with viruses.