[The state of the regenerative activity of the tympanic membrane tissues and the results of myringoplasty at different time points of remission of experimental otitis media].

The objective of the present study was to estimate the regenerative potential of the tympanic membrane tissues in the early period of remission after experimental otitis media and evaluate the results of myringoplasty. The experiments were carried out using 23 outbred dogs exhibiting no signs of "spontaneous otitis". Experimental otitis media was induced in 20 animals using a Staphylococcus aureus strain as the pathogenic organism. The treatment of the experimental animals was started two weeks after the development of otitis and continued up to obtaining the "dry ear" condition. The animals were allocated to 4 groups depending on the time of myringoplasty. In the animals of group 1 myringoplasty was performed one week after remission, those of groups 2, 3, and 4 underwent myringoplasty two, three, and four weeks after the onset of remission respectively. The results of the study indicate that the first two weeks after the inflammatory process in the middle ear subsided are the optimal time for myringoplasty because the proliferative activity during this period amounts to its maximum which promotes the survival of the transplant and the closure of tympanic defects.

[Dynamic changes in the microbial contamination of the exudate and the mucous membrane from the tympanic cavity in the course of experimental staphylococcal otitis media].

The objective of the present study was to determine the relationships between characteristics of the microbial contamination of the pyogenic exudate and the mucous membrane from the tympanic cavity in the course of experimental suppurative otitis media caused by staphylococcal infection. The experiments were carried out on 29 rabbits showing no signs of "spontaneous" otitis. Experimental staphylococcal suppurative otitis was induced in 26 of these animals. The degree of microbial contamination of the mucous membrane from the tympanic cavity was expressed either in colony-forming units per swab (CFU/swab) or as the number of microbial cells per 1 mg of the tissue. It was shown that microbial contamination of the exudate and the mucous membrane from the tympanic cavity depended on the extent of the inflammatory process in the middle ear in the course of experimental staphylococcal otitis. The highest degree of contamination fell on the acute phase of middle ear inflammation. Staphylococci disappeared from the mucous membrane sooner than from the exudate. This difference can be attributed to the different activity of the tssue immunity factors.

[The comparative characteristic of the microflora species composition in the tympanic cavity, nasal mucous membrane and external ear mucosa in the course of experimental suppurative staphylococcal otitis].

The objective of the present work was to study the species composition of microflora in the suppurative exudate from the tympanic cavity in the course of development of experimental suppurative staphylococcal otitis and to identify the initial sites of migration of secondary pathogens. The experiments were carried out on 20 adult rabbits showing no signs of "spontaneous" otitis. Experimental staphylococcal suppurative otitis was induced in 17 of these animals. The microbiological study included isolation and identification of pure bacterial cultures with the use of the classical method. The initial sites of migration of secondary pathogens were detected from the results of comparison of the species composition of microflora in tympanic exudate and the mucous membrane of the nearest anatomical regions, such as the nasal cavity an external auditory canal. The data obtained indicate that suppurative exudate from the tympanic cavity is populated by polyflora containing secondary pathogens, besides the principal ones (Staphylococci). The large amounts of secondary pathogens penetrate into the tympanic cavity from the mucous membranes of the nasal cavity and nasopharynx. It is concluded that the rhinotubal system is the major pathway through which pathogenic microflora migrates into the middle ear.

[Characteristics of microbiocenosis of gingival pocket in patients with chronic generalized periodontitis].

As a result of examination of 56 patients with chronic generalized periodontitis (CGP) of a moderate severity and a severe form of the disease, microflora from gingival pocket in patients which severe form of CGP was established to have higher specific weight in index of dissemination of strains such as Staphylococcus aureus, Streptococcus pyogencs, Enterococcus, Corynebacterium spp., anaerobic bacteria. Strains from patients with a severe form of CGP were characterized by a higher level of expression of the factors of pathogenicity and persistence. Associations of streptococci and staphylococci which the representatives of anaerobic flora such as Bacteroides, Fusobacterium, Prevotella, Clostridium, Peptostreptococcus were more often revealed in patients with a severe form of CGP. Fact of microbial translocation from the gingival pocket was established: from the blood of the patients with CGP of a severe form, strains-translocants were cultivated by 4 times more frequently than from the patients with CGP of a moderate severity.

[Biological characteristics of translocating bacteria during experimental otitis media].

AIM: To study dynamics of species composition, factors of pathogenicity and persistence, index of microbial load by bacteria translocating to tympanic cavity from nasal cavity. MATERIALS AND METHODS: Translocation of bacteria was reproduced on the model of experimental staphylococcal purulent otitis media in 22 adult rabbits from "chinchilla" breed. Identification of translocating strains was performed by radioisotope label. Microflora of nasopharynx and middle ear was studied on day 4, 6, 10, 20, 30, and 180 after inoculation. RESULTS: Translocating strains differed from nontranslocating by higher level of antilysozyme activity (> or =3 mcg/ml) and higher proportion of their microbial load in total index of microbial load of source biotope (> or =5%). During unfavorable course of otitis, increase of pathogenicity of strains-translocants in circumstances of microbial interaction was observed. CONCLUSION: One of the mechanisms for the development of otitis media is translocation of indigenous bacteria and their associates to the inflammation site in middle ear where microbial interactions determine the outcome of infection. Results of experimental studies allowed to develop the method for prediction of otitis media course.

[The role of persistence and virulence factors in microecological changes in a humans].

The patterns of persistence and virulence factors expression in the representatives of human microbial biocenosis depends on a complex of the environmental conditions: influence of microbes-symbionts, biotope peculiarities, properties of microorganisms located within eukaryotes. Interactions of symbionts in pairs "indigen-indigen" isolated from mucous membrane of tonsils in healthy persons, did not lead to changes in expression of pathogenic properties. Interinfluence in pairs "pathogen-indigen" and "indigen-indigen", isolated from patients with chronic tonsilitis were accompanied by an increase of anti-lysozyme, hemolytic and lecithovitellase activities. Migration of strains of non-enzymatized gram-negative bacteria (NEYNB) from nasal into tympanic cavity in experimental acute purulent otitis is connected with an earlier increase of their number in the nasal cavity and the expression of anti-lysozyme activity. In acute and chronic pyoderma, expression of ALA is more marked in bacteria from a perifocal damage in contrast to focal damage of normal skin. In conditions of interaction between erythrocytes and staphylococcal clones with different levels of expression of pathogenic factors, differences were observed in dynamics of hemolytic and anti-hemoglobin activities.

[Microbial biocenosis in the mucous membranes of the nose and the middle ear in patients with purulent otitis]. / Mikrobnyi biotsenoz slizistykh obolochek nosa i srednego ukha u bol'nykh gnoinym otitom.

25 biocenoses of the microflora of the mucous membranes of the nose and the middle ear in patients having acute and chronic purulent otitis media (epi- and mesotympanitis) were studied. The dynamic study was carried out at the peak of the manifestations of clinical symptoms and on convalescence or improvement of the state of patients. In the process of convalescence the normalization of the composition of the microflora of the nose and the middle ear was found to occur in patients having acute otitis as compared with those having chronic otitis. In chronic otitis dysbiosis was observed in the microflora of the nose and the middle ear (the preservation of Staphylococcus aureus and enterobacterial strains with increased capacity for persistence). Correlation between the taxonomic composition and the biological properties of the microflora of the nose and the middle ear was established. Changes in the properties of individual strains of the microflora in the bacterial interaction of symbionts were more pronounced in the acute form of otitis than in the chronic one.

[Comparison of repeat DNA sequences in the Erinaceidae mammal family by restriction analysis]. / Sravnenie povtoriaiushchikhsia posledovatel'nostei DNK mlekopitaiushchikh semeistva Erinaceidae metodom restriktaznogo analiza.

Hedgehog (Erinaceidae) DNA was digested with teh Sau 96 I, Bsp 143 I, Csp 6 I, Taq I, Hinf I, Msp I, Eco 130I, Bcn I, BsuR I restriction endonucleases. The obtained products were end-labeled and electrophoretically separated in polyacrylamide gel. DNA fragments consisting of highly repetitive genomic sequences were detected as a set of bands corresponding to fragments between 30 and 500 bp in length. Comparison of DNA restriction patterns of the species analyzed revealed the presence of species-specific bands as well as common bands. Phylogenetic trees were constructed by means of the maximum parsimony method and the bootstrap procedure. Our data suggest that hedgehog species from arid areas are clearly distinguished from forest species.

[The reproductive potential of the bank vole (Clethrionomys glareolus Schreb) and of the tundra vole (Microtus oeconomus Pall.) under the conditions of the elevated radiation background of Bryansk Province]. / Potentsial razmnozheniia ryzhei polevki (Clethrionomys glareolus Schreb) i polevki-ékonomki (Microtus oeconomus Pall.) v usloviiakh povyshennogo radiatsionnogo fonda Brianskoi oblasti.

The continuous irradiation (connected with the accident on the Chernobyl atomic power plant) by cesium-137 of the dominant species of rodents (Clethrionomys glareolus, Microtus oeconomus) in the forests of Bryansk Province had a deteriorating effect on the state of reproductive organs and on the course of embryogenesis, stimulated the reproduction cycle but inhibited the rate of sexual maturation and increased the death-rate of young animals. These effects resulted in significant ageing of the population. But all these phenomena provoked by radiation are within the limits of rodents adaptive capacities.

[The biological indication of the radiation load in forest communities of small mammals]. / Bioindikatsiia radiatsionnoi nagruzki v lesnykh soobshchestvakh melkikh mleokipitaiushchikh.

The content of cesium-137 in the organisms of different species of small mammals in forests of Bryansk Province five years later the Chernobyl accident varies to a great extent within some modal value n.10(-6)-n.10(-7) Cu/kg. Gamma-radiation is about 200 mcR/h. The revealed radiation level results in increased mortality during embryonal and postnatal periods, as during these periods a very intensive process of radiocesium accumulation in the animal organism takes place. Statistically valid differences of young and old animals ratio with the asymmetrical deviation towards old age groups have been found on the polluted territory at the end of summer season.