Transcriptome of Lung Cancer Cells Resistant to the Cytotoxic Activity of Macrophages.

The role of the immune system in tumor progression has been the subject of research for more than 100 years since Paul Ehrlich hypothesized that the presence of the immune system limits the occurrence of cancer. One of the mechanisms hindering the initiation and progression of the tumor is the cytotoxic activity of macrophages; however, in some cases, it is not sufficient to control tumorigenesis. This may be due to both the development of resistance of tumor cells to the antitumor activity of macrophages and the development of a tolerant phenotype of macrophages that do not have sufficient antitumor activity. In this work, the lung cancer cells resistant to the cytotoxic action of macrophages were obtained and characterized for the first time, and the genes associated with the observed changes were identified. Understanding the mechanisms of resistance of tumor cells to the cytotoxic activity of macrophages and the peculiarities of its manifestation in a tumor environment is critically important for improving the effectiveness of the existing methods of cancer treatment and developing novel methods for tumor immunotherapy.

[The likely role of protozoa in the maintenance of the environmental circulation of enteroviruses].

The purpose of the study was to define the likely role of protozoa as a possible natural reservoir for enteroviruses and their involvement in enterovirus-induced serous meningitis morbidity. Samples were taken from the running and standing water reservoirs of the Orenburg Region in the summer-autumn period and those of wastewaters were collected at all purification stages. Enteroviral RNA in the protozoan cultured was detected by the reverse-transcription polymerase chain reaction (PCR). The Ural River was found to contain 72 protozoan species; there were 15 and 38 protozoan species in the lakes and wastewaters, respectively. With PCR, enteroviruses were detected in 61.8% of the cultures of protozoa which belonged to 23 species of flagellates, amoebas, and infusoria isolated from the natural water reservoirs exposed to an anthropogenic load, as well as from the wastewaters at all purification stages. The predominant localization of enteroviruses was observed in the dominant taxons of the protozoa Paraphysomonas sp., Spumella sp., Petalomonas poosilla, Amoeba sp.

[Regulation of symbiotic interactions in algobacterial associations].

AIM: To study mechanisms of survival and regulation of natural algobacterial associations. MATERIALS AND METHODS: Lysozyme, antilysozyme, catalase and antagonistic activity as well as hydrogen peroxide production were determined in algobacterial associations formed by green algae or cyanobacteria and satellite bacteria. For assessment of reactions of microbial interactions, derivates of Escherichia coli, which differ on the presence of antilysozyme and catalase signs, were used. RESULTS: Multidirectional effects of symbionts in biocenosis were revealed. Involvement of functional systems lysozyme-antilysozyme and hydrogen peroxide-catalase in regulation of associative interactions in algae-bacterial biocenosis was established. In conditions of antibacterial action of algae's hydrogen peroxide, catalase activity of associate bacteria provides survival of microorganisms in association with algae, whereas high level of catalase activity promotes domination of associate bacteria in algobacterial communities. Antagonistic activity allows the microalgae to suppress growth of undesirable microorganisms and regulate their number in algobacterial cenosis. CONCLUSION: Functional systems lysozyme-antilysozyme, hydrogen peroxide-catalase as well as antagonistic activity of symbionts form the basis for regulation of symbiotic interactions in associations of water microorganisms, which has ecological and sanitary-hygienic implications.

[Contamination of protozoa by enteroviruses in fresh water and sewages].

AIM: To determine rate of infection of protozoa by enteroviruses to assess the potential role of protozoa as a natural reservoir of enteroviruses. MATERIALS AND METHODS: The samples were collected from flowing and stagnant water reservoirs in Orenburg region in summer and autumn. The samples of sewages were taken in all stages of their treatment. Cultures of protozoa were isolated with micromanipulator equipped with micropipette, incubated on Pratt's medium at 25 degrees C and fed with Pseudomonas fluorescens culture. RNA of enteroviruses was detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Seventy-two protozoan species were found in Ural river, whereas 15 and 38 species were found in lakes and sewages respectively. Enteroviruses were detected by RT-PCR in 61.8% cultures of protozoa belonging to 23 species of flagellates, amoebae and ciliates isolated from natural water bodies undergoing anthropogenic impact as well as from sewages in all stages of their treatment. Predominant localization of enteroviruses in dominant taxons of protozoa (Paraphysomonas sp., Spumella sp., Petalomonas poosilla, Amoeba sp.) was noted. CONCLUSION: Obtained data confirm presence of enteroviruses in protozoa living both in flowing and stagnant recreation natural water bodies as well as in sewages and confirm the hypothesis of persistence of enteroviruses in protozoa and the reservoir role of the latter. Contingency of life cycles of viruses and protozoa allows to explain the seasonality of aseptic meningitis incidence caused by enteroviruses, which peaks in summer and autumn when protozoa massively multiply in water bodies.

[Histone-antihistone interactions in the Escherichia coli-Tetrahymena pyriformis association].

Using the Escherichia coli-Tetrahymena pyriformis system, we revealed the involvement of bacterial antihistone activity and protozoan histones in interactions between pro- and eukaryotic microorganisms. Antihistone activity enhanced the viability of E. coli in association with T. pyriformis, according to our data on the dynamics of E. coli cell numbers. The strain with antihistone activity induced incomplete phagocytosis in the infusorians, resulting in cytological changes and ultrastructural alterations that indicated the retention of bacterial cells in phagosomes. Bacteria with antihistone activity located in the T. pyriformis cytoplasm influenced the eukaryotic nucleus. This manifested itself in macronucleus decompactization and a decrease in the average histone content in the population of infusorians. The data obtained suggest that protozoan histone inactivation by bacteria is one of the mechanisms involved in prokaryote persistence in associations with eukaryotic microorganisms.

[Effect of bacterial satellites on Chlamydomonas reinhardtii growth in an algo-bacterial community].

The growth characteristics of an algo-bacterial community (Chlamydomonas reinhardtii and bacterial satellites) were studied, as well as the mechanism and patterns of bacterial effect on algae. Four strains of predominant bacteria were isolated and partially characterized. They were assigned to the following taxa: Rhodococcus terrea, Micrococcus roseus, and Bacillus spp. A pure culture of the alga under study was obtained by plating serial dilutions on agarized media with ampicillin. Within the algo-bacterial association, the alga had a higher growth rate (0.76 day(-1)) and yield (60 microg chlorophyll/ml culture) than in pure cultures (0.4 day(-1) and 10 microg chlorophyll/ml culture, respectively). The viability of the algal cells within the association was retained longer than in pure culture. Among the isolated bacterial satellites, strains B1 and Y1, assigned to the species Rhodococcus terrae, had the highest stimulatory effect on algal growth. The culture liquid of bacteria incubated under the conditions not permitting growth stimulated algal growth; the culture liquid of actively growing bacteria had an opposite effect.

[Taxonomic characteristics and physiological properties of microorganisms from the gut of pike (Esox lucius)].

The taxonomic composition and distribution of microorganisms differing in the degree of association with the intestinal mucosa of the pike (Lucius lucius) has been studied. Microorgansism of the families Enterobacteriaceae, Aeromonadaceae, and Vibrionaceae dominate in the gut microflora. Numerically prevailing bacterial species are characterized by high proteolytic and amylolytic enzyme activities as well as by high persistence accounted for by antilysozyme and antihistone activities. The results of this study show that Hafnia alvei, Yersinia ruckeri, Vibrio vulnificus, V. furnissii, Aeromonas salmonicida, and Shewanella putrefaciens may be regarded as normal components of the pike gut microflora.

[Opisthorchiasis in the Ob-Irtysh river basin: etiology and pathogenesis].

Opisthorchiasis in the hyperendemic focus (Ob-Irtysh river basin) is considered to be a co-member of parasitocenosis: opisthorchiasis + methorchiasis and to have a superinvasive form. The symbiotic flora and O. felines metabolites are an etiopathogenetic flora. Scientific evidence is provided for the recurrent forms ofopisthorchiasis; the authors consider it to be the type of superinvasive opisthorchiasis, in which some portion of parasites in microballs unexposed to antheminthics further mature to maritae.

[Symbiotic microflora in fishes of different ecological groups].

Published data on the taxonomic composition of the intestinal bacterial flora in fishes living under different conditions (marine and freshwater fishes) and differing in the type of feeding are reviewed. The results confirm the conclusion that the composition of intestinal microflora differs depending on fish ecology. A limited number of bacterial taxa found in the intestines of some fish species may be evidence not only for a low diversity of these bacteria but also for insufficient knowledge about them. Considerable differences in the composition of intestinal microflora in marine and freshwater fishes are described.

[The symbiotic microflora associated with the tegument of proteocephalidean cestodes and the intestines of their fish hosts].

The indigenous symbiotic microflora associated with the tegument of proteocephalidean cestodes and the intestines of their fish hosts has been investigated in morphological and ecological aspects. The indigenous microflora associated with the cestode tegument consists of the nannobacteria population, which was present obligatorily on the surface of tegument, and the "deep microflora". The deep microflora associates with some few species of parasites only. Each individual host-parasite micro-biocenosis includes specific indigenous symbiotic microorganisms, with the differing microfloras of host intestine and parasite. Physiology, biochemistry and/or diet of hosts apparently influence on the symbiotic microflora's structure of parasites. The least bacteria abundance and diversity of their morphotypes were observed in the parasites from baby fishes. The diversity and abundance of bacteria were increased with the fish host ageing and the formation of the definitive structure of its intestine. It is an evidence of the gradual invading of the intestinal parasites (cestodes) tegument by bacterial cells. The invading is realized on the base of the microflora that was present in the food of fish host. The symbiotic microflora has specific morphological features, can regulate the homeostasis of the cestodes and fish hosts and also can maintain equilibrium of alimentary and immune interrelations in the host-parasite system.

[Symbiosis in survival of microorganisms in hyperhaline water reservours].

Differently directed effects from autochthonous algae and bacteria on allochthonous microflora in hyperosmotic conditions were revealed and analyzed. Living halophilic microorganisms increase survival time of enterobacteria. Cellular extracts from halophils decrease storage time of allochthonous bacteria in a highly mineralized medium. Allochthonous bacteria in hyperosmotic conditions are able to suppress viability of autochthonous halophilic microflora. Symbiotic interactions between autochthonous and allochthonous microorganisms, defined by correlation of protective and antagonistic effects, regulate survival of microorganisms in hyperhaline water reservours and can be used for the assessment of their ecological and sanitary-and-hygienic states.

[Indigenous microflora associated with the tegument of Triaenophorus nodulosus (Cestoda) and the intestine of its pike host].

Investigations of the indigenous microflora associated with the mucous intestines of fish and its cestode parasites have been for the first time carried out using the methods of transmission and scanning electron microscopy. New data on the bacterial biodiversity in the cestode and its fish host are obtained. Nanobacteria and spirochaetes are for the first time revealed in a fish host together with the previously known bacteria forming the intestinal microflora of fish. Spirochaetes were shown to be associated with the intestines of a pike host only, while nanobacteria cover abundantly the surface of the apical parts of the intestinal microvilli and the apical parts of the microtriches in the cestode tegument. The similarity of the bacterial floras associated with the apical surface of the parasite tegument and the intestine of the host should be noted. At the same time, deeper bacterial communities represented by obligate symbionts are specific. Thus, there is a normal indigenous microflora in cestodes, associated with the tegumental surface. This symbiotic microflora has specific morphological features and provides the balance of relations in the parasite-host system.

[Properties of Staphylococcus aureus in case of the unfavorable course of burn infection]. / Svoistva Staphylococcus aureus pri neblagopriiatnom techenii ozhogovoi infektsii.

Clinical and microbiological study of wound discharge from 35 patients demonstrated a relationship between biological properties of S. aureus, the causative agent of burn infection, and the course of the infected burn trauma. The prognostic importance of the antioxidant properties of these staphylococci was established: in cases of the unfavorable course of the burn process they showed essentially greater resistance to peroxinitrite and higher superoxide dismutase activity in comparison with the cultures isolated from patients with uncomplicated wound infection.

[Persistent properties of protozoa-associated bacteria]. / Persistentnye svoistva bakterii-assotsiantov prosteishikh.

The species structure and persistent properties (antilysozyme and antihistone activity) of bacteria forming associations with protozoa is revealed. Among them, 68.9% of the isolates were enterobacteria, the remaining organisms belonged to the families Aeromonas, Alcaligenes, Pseudomonas, Vibrio, etc. Within the family Enterobacteriaceae bacteria of the Escherichia group prevailed. 50.4% of the isolates were found to have antilysozyme activity and 97%--antihistone activity. The level of persistent properties in the representatives of allochthonous microflora was higher than that in the representatives of autochthonous microflora. In addition to antilysozyme activity antihistone activity was noted in protozoa-associated bacteria, which could be of importance for the formation of symbiotic links in natural associations. These data may be used in sanitary and hygienic practice for microecological monitoring of the environment.