[The characteristics of probiotic properties of strains of genus of bifidobacterium separated from gastrointestinal tract of residents of the central region of Russia].

The 156 samples of feces separated from healthy residents of the Central region of Russia were used to compose collection of 87 strains of Bifidobacterium out of which 5 strains with wide antagonistic activity related to pathogenic and opportunistic microorganisms were selected. The selected strains are characterized by high probiotic potentials. They have adhesive properties and sensitivity to antibiotics and preparations corresponding to main requirements of common pharmacopoeia articles to strains of microorganisms used in production of probiotics for medicinal application. The given strains of Bifidobacterium can be recommended for development of effective probiotic pharmaceuticals directed to residents of the Central region of Russia.

[Antagonism of lactobacilli, oral streptococci and staphylococci].

From the oral cavity of healthy young people aged 18-22 years there were isolated 26 strains of lactobacilli, 28 streptococci, including the pathogenic and opportunistic strains, and 32 strains of staphylococci, 10 of which were methicillin-resistant S.aureus. Oral lactobacilli possessed by a high probiotic potential, showing high antagonism to methicillin-resistant staphylococci, pathogenic and opportunistic streptococci and enterococci. Oral lactobacilli showed medium and high adhesive activity that determines their high adaptive capacity. Staphylococci and streptococci in 90.3% of cases have not an antagonistic effect on lactobacilli. Isolated lactobacilli can be used as probiotic strains for oral administration.

[The microbiocenosis of intestine and immune status of children of primary school age].

The article deals with the study of species and quantitative structure of microbiocenosis of intestine and characteristics of immune status in children aged 8-10 years. In children with chronic tonsillitis pharyngitis and bronchitis and with diseases of gastro-intestinal tract (biliary dysfunction, chronic gastroduodenitis and gastritis) the microbe imbalance of various degree of manifestation was established which was prevailing in cases of children with pathology of gastrointestinal tract. The increase of quantity of opportunistic microflora induces the production of both immunoglobulins and cytotoxic lymphocytes and cells-natural killers.

[The disbiotic changes of intestines microflora in healthy people].

The article presents the results of study of species and quantitative composition of intestinal flora in volunteer students aged 18-21 years. The disbiotic abnormality of different degrees was diagnosed in 75% of students. The associations of microorganisms, in case of normobiosis and disbacteriosis degree I included predominantly representatives of normoflora, in case of disbiotic abnormality II and III degrees included both representatives of normoflora and opportunistic pathogenic microorganisms.

[Spring water quality assessment regarding the problem of endemic fluorosis].

A possible variant for reducing the consumption of fluoride by population of Tver region is the use of water with low fluoride content, such as spring water. Assessment of drinking suitability of spring water (the content of physiologically important mineral elements and microbial purity) is relevant to our region. Water samples from 6 spring-water source of Tver region were studied during the year. The content of fluoride and calcium were measured by using an ion-selective electrodes. Microbiological purity tested by the presence of total coliform bacteria, thermotolerant coliform bacteria, coliphages and total microbial numbers. The analysis of some mineral components in spring water of Tver region showed that calcium content was in range 33-88 mg/l, that satisfied the recommended value; fluoride concentration is less then 0.5 mg/l. In all spring water samples total coliforms, thermotolerant coliforms and coliphages were absent. The total microbial number was in standard range, except of two spring-water source in the autumn and summer. The data suppose that spring water of Tver region can be used as a component of diet normalizing the fluoride consumption at risk of dental fluorosis in children.

[Effect of diazoxide on the AS-30D rat ascites hepatoma cells treated by Cd2+].

For the last years, in several investigations, including ours, it was shown that oxidative stress and mitochondrial dysfunction mediated by disturbance of the mitochondrial respiratory chain and by induction of Ca2+ -dependent nonselective high-conductance pore of the inner mitochondrial membrane are involved in mechanism(s) of cytotoxic action of heavy metals. At the same time, possible interaction of heavy metals with other channels, in particular, with selective potassium channels, such as ATP-dependent potassium channels, which are generally considered to be protective for the cells, have not been studied. The aim of the present work was to examine the effect of diazoxide, an activator of mitochondrial ATP-dependent potassium channels, on mitochondrial physiology and cell survival in the presence of Cd2+. As a model system, we used AS-30D rat ascites hepatoma cells and isolated rat liver mitochondria. We found that diazoxide enhanced intracellular production of reactive oxygen species and induced significant stimulation of the resting respiration rate of the cells. Besides, diazoxide had a protective effect on AS-30D cells by increasing their survival that was substantially decreased in the presence of the tested concentrations of Cd2+ (50 and 100 microM). The protective effect of diazoxide was completely suppressed by increasing duration of incubation of the cells with Cd2+, and partially by addition to the assay medium of 5-hydroxyde- canoic acid (100 or 300 microM), a blocker of mitochondrial ATP-dependent potassium channels. In isolated rat liver mitochondria we found that diazoxide did not prevent the toxic action of Cd2+, since it produced no significant effects on the mitochondrial swelling and the respiration changes evoked by the heavy metal in the KCl assay media. Possible molecular mechanisms of the cytoprotective action of diazoxide are discussed.

[Peculiarities of functioning of liver mitochondria of river lamprey Lampetra fluviatilis and common frog Rana temporaria at periods of suppression and activation of energy metabolism].

The work dealt with study of mitochondria in reversible metabolic suppression of hepatocytes of the river lamprey Lampetra fluviatilis in the course of prespawning starvation and of liver mitochondria of the common frog Rana temporaria during hibernation and activity. In winter the metabolic depression of lamprey hepatocytes, unlike that of frog hepatocytes, has been found to be due to deactivation of complex I of the electron transport mitochondrial chain, a low rate of NAD-dependent substrate oxidation, a low content of adenine nucleotide content, and a high degree of mitochondrial membrane permeability to H+ and other monovalent ions (KCl-, K+). The mitochondrial membrane permeability decreases in the presence of ethyleneglycoldiamineethyltetraacetic acid (EGTA), cyclosporine A (CsA), adenosine-5'-diphosphate (ADP), and Mg+. These facts indicate the presence in these mitochondria of the Ca2+ -dependent unspecific pore in the low-conductance state. Histological studies showed the lamprey and the frog to have principal differences in use of energy substrates at the period of metabolic depression. Lampreys utilize predominantly lipids, whereas frogs--glycogen. The clearly pronounces activation of lipid consumption is observed at the spring period before spawning and death of lamprey. Possible causes of metabolic depression are discussed as well as similarity and difference in behavior of mitochondria of cyclostomes and amphibians throughout metabolic depression and activity.