[Use of metabolic drugs and psychotherapy in dental implantation in elderly patients].

The estimation of efficiency of metabolic drugs and psychotherapy in dental implantation in the elderly was carried out. On the basis of the study results an important pathogenetic significance of use of metabolic drug cytoflavin and cognitive therapy in the treatment of partially adentia at elderly patients was justified. It was proved that the optimization of the internal picture of health by means of the implementation of information and regulatory functions, and emotional reinforcement of the therapeutic process in patients receiving cytoflavin and cognitive therapy would improve the effectiveness of the treatment, to increase "survival" performance of implants and to approach to understanding the underlying mechanisms of forming health in elderly patients with partial adentia.

[Supernumerary chromosomes, segmental duplications, and evolution].

The present study depicts the phenomenon of supernumerary chromosomes as autonomous genome elements, similar in features with segmental duplications. Possible role of B chromosomes in evolution and the reasons of their nonrandom distribution in different mammalian taxa are discussed.

[Comparative cytogenetics of main Laurasiatheria taxa].

This short communication is a review of key trends in the karyotypic evolution of mammalian taxa Laurasiatheria, inferred from comparative chromosome painting.

[Modification of DNA with 4-aminooxybutylamine as a method for obtaining highly-sensitive hybridization probes. Mapping of the gene for human chorionic somatomammotropin hormone]. / Modifikatsiia DNK 4-aminooksibutilaminom kak sposob polucheniia vysokochuvstvitel'nykh gibridizatsionnykh zondov. Lokalizatsiia gena khorionicheskogo somatomammotropnogo gormona cheloveka.

A new method for preparation of highly sensitive nonradioactive probes for dot, dot-blot and in situ hybridization was developed. The method is based on chemical modification (transamination) of cytosine residues with 4-aminooxybutylamine following by coupling biotin or fluorescein to aliphatic aminogroups introduced into DNA. Such a probe have been used for detection of gene encoding chorionic somatomammotropin hormone (hCS) in genomic blot hybridization. The gene hCS was mapped using isotopic and nonisotopic in situ hybridization on human chromosome 17.

[Reverse transcription of heterologous RNA by RNA-dependent DNA polymerase from Escherichia coli]. / Obratnaia transkriptsiia geteropolimernoi RNK s pomoshch'iu RNK-zavisimoi DNK-polimerazy Escherichia coli.

The appropriate conditions for the reverse transcription of rabbit globin mRNA by E. coli RNA-dependent DNA polymerase has been studied. By reducing the ionic strength, increasing the incubation temperature from 37 to 43 degrees and predenaturing the template it was possible to increase the cDNA size. The molar ratio of Mn2+ and dNTP optimal for cDNA synthesis is approximately 1.5-1.7:1. The increase of dNTP concentration from 0.05 to 0.4 mM each, under conditions of Mn2+ deficiency, results in the decrease of the cDNA size to 4S, obviously, the inhibitory effect of dNTP is not complexed with Mn2+. The synthesis of cDNA is inhibited also by the excess of Mn2+. Hybridization of cDNA with globin mRNA protects the former from S1-nuclease. Optimization of the conditions for reverse transcription of heterologous RNa by E. coli RNA-dependent DNA polymerase led to the increase of the cDNA length up to approximately 550 nucleotides which is about 70% of the RNA template length.

[Location of RNA-dependent DNA polymerase within the endogenous template complex and discrimination of RNA- and DNA-dependent synthesis of DNA in Escherichia coli cells by alkylating dTTP gamma-amide]. / Lokalizatisiia kompleksa RNK-zavisimoi DNK-polimerazy s éndogennoi matritsei i diskriminatsiia alkiliruiushchim gamma-amidom dTTP RNK- i DNK-zavisimogo sinteza DNK v kletkakh Escherichia coli.

These data demonstrate that actinomycin D inhibits only 75-80% of DNA synthesis in cells of E. coli treated by lysozyme and ethyl enediaminetetraacetate. The residual synthesis is not the result of untemplated polymerization of dNTP. The DNA synthesis in spheroplasts does not correlate with replication of chromosomal DNA of E. coli catalyzed by DNA polymerase III sensitive to sulfhydryl blocking agents. N-ethylmaleimide does not inhibit this synthesis. No ATP stimulation of DNA synthesis is observed. The enzyme(s) responsible for DNA synthesis on endogenous template is (are) concentrated in interphase (D-fraction) as revealed by high speed centrifugation of spheroplasts lysate and they are absent in the chromosomal DNA fraction. dTTP 4-(N-2-chloroethyl-N-mehylamino) benzylamide suppresses completely the insensitive to actinomycin D action DNA synthesis and practically does not act on the sensitive one. It is suggested, that the DNA synthesis stable to the action of the antibiotic is catalyzed by RNA dependent DNA polymerase.

[Highly-sensitive nonradioactive detection of the tick-borne encephalitis virus]. / Vysokochuvstvitel'naia neradioaktivnaia detektsiia virusa kleshchevogo éntsefalita.

The non-radioactive reverse dot-blot method was used for the detection of tick-borne encephalitis virus (TBEV) in clinical specimens. The method involves reverse transcription (RT) and polymerase chain reaction (PCR) using a pair of biotin-labelled oligonucleotide primers. These primers flank a region in the gene of the envelope protein E, which is more conserved than other regions, and initiate the polymerisation with RNAs of all the investigated strains. The amplified cDNA was captured from solution on a solid support using complementary oligonucleotides covalently bound to a polyamide membrane. The biotin labels of the resulting hybrids were visualized by means of the streptavidin-horseradish peroxidase conjugate. The detection limit of the test was about 10(3)-10(4) molecules of target RNA. The sensitivity was comparable to that obtained by dot-hybridization of PCR-product with 32P-labelled DNA probe. The method was used for the detection of RNA in specimens of tick and blood.

[rRNA synthesis im Drosophila melanogaster lines with different nucleolus organizer contents]. / Sintez rRNK v liniiakh Drosophila melanogaster s raznym soderzhaniem iadryshkovykh organizatorov.

Regulation of the rate of RNA synthesis in Drosophila melanogaster diploid cells with 1, 2, 3 and 4 nucleolar organizers is studied. The data indicate that in flies with the redundant nucleolar organizer (NO) content extra NOs are eliminated by the 18th generation and the level of rRNA synthesis is typical for control wild stock flies. In flies bearing single NO on the Y chromosome, extra rDNA replication does not occur and rRNA genes deficiency by the increased rRNA synthesis is compensated. It is suggested that in genotypes studied the rate of rRNA synthesis depended on sex chromosome quantity per genome.

[Electron microscopic research on the extrachromosomal genetic elements of Escherichia coli]. / Elektronno-mikroskopicheskoe issledovanie vnekhromosomnykh geneticheskikh élementov Escherichia coli.

The structural organization of extrachromosomal genetic elements were studied in a subfraction obtained after centrifugation of the lysate of E. coli spheroplasts. With this method of isolation, the tertiary structure of the extrachromosomal genetic elements was preserved. The majority of DNA macromolecules were released in the form of single and connected rosettes. Typical rosettes composed of radial loops of DNA clustered around the central dense core (the diameter is about 60 nm). The mean length of the rosette loops was 1.06 +/- 0.4 micron. Both relaxed folded and supercoiled folded forms of DNA were observed on the preparation. Sometimes the rosettes were connected with large aggregates of DNA (possibly the material of bacterial chromosomes) and had the appearance of thick fibers with numerous lateral loops. Linear, cyclic and various replicative forms of DNA have also been observed. It is assumed that rosettes of the extrachromosomal elements of E. coli reflect one of the levels of organization of prokaryotic genetic material.

[Feasibility of analysis of macroevolutionary rearrangements of mammalian chromosomes]. / Vozmozhnosti analiza makroévoliutsionnykh preobrazovanii khromosom mlekopitaiushchikh.

In the Institute of Cytology and Genetics, Siberian Division, Russian Academy of Sciences, detailed studies on chromosome sets of humans and domestic animals were initiated and supported by D.I. Belyaev and started by S.I. Radzhabli. They believed that analysis of differentially stained chromosomes and mapping of the genomes of main commercial species provide for a better understanding of the processes that occurred during their evolution and domestication. Several new approaches to studying macroevolutionary karyotypic rearrangements associated with divergence of remote taxa, such as primates and paridigitate ungulates, are discussed.

[Prospects for obtaining a mapping panel for somatic cell marsupial-rodent hybrids for the short-tailed opossum Monodelphis domestica]. / Perspektivy polucheniia kartiruiushchei paneli gibridov somaticheskikh kletok sumchatoe-gryzun dlia korotkokhvostogo opossuma Monodelphis domestica.

A possibility of obtaining a panel of marsupial-rodent somatic cell hybrid clones has been explored, with a view to mapping the genome of the opossum (Monodelphis domestica). Fusion of opossum cells (splenocytes, bone marrow cells, and fibroblasts) with fibroblasts of Chinese hamster or vole (HGPRT- and TK- mutants, respectively) produced 146 hybrid clones. The majority of marsupial-mammalian somatic cell hybrids were characterized by pronounced fragmentation and segregation of marsupial chromosomes. To overcome this difficulty, a method for rapid screening was developed, which allowed the early selection of clones rich in chromosomal material of opossum. Based on the screening results, 25 clones of independent origin were selected. A detailed genetic analysis, which included chromosome G-banding and in situ hybridization of biotin-labeled opossum DNA on metaphase chromosomes, allowed further selection of seven hybrid clones containing one to six intact chromosomes of M. domestica. Opossum chromosomes were present in various combinations against the background of Chinese hamster or vole chromosomes. The clones will be included in the panel of opossum-rodent somatic cell hybrids, which is currently being created.

[Participation of the chemotactic system in regulating cell division in Escherichia coli]. / Uchastie sistemy khemotaksisa v reguliatsii kletochnogo deleniia u Escherichia coli.

The possible role of the chemotaxis system in regulating cell division of Escherichia coli was studied. Attractants increased the rate of division whereas repellents reduced it. Non-metabolisable attractants analogues were also effective in stimulating cell division. Fucose, a non-metabolisable analogue of galactose, increased the rate of division by 20-25%. Co2+ at concentrations which had no effect on the tar-mutant division suppressed the division of the wild type. Likewise, indole at concentrations which did not influence the division of the tsr-mutant, suppressed the division of the wild type.

[Antimutagenicity of propionic acid bacteria]. / Antimutagennost' propionovo-kislykh bakterii.

The antimutagenicity of the cell extracts of Propionibacterium shermanii VKM-103, P. pentosaceum CCM 1859 and P. acnes CCM 3322 against mutagenicity of sodium azide and N-methyl-N'-nitro-N-nitrosoguanidine was demonstrated for the first time. The extracts of propionic acid cocci didn't show such effect. The antimutagenic factor acts as a desmutagen, has polypeptide nature and evidently is an enzyme (enzymes). The inhibitory effect of the extract is due to the presence of more than one protein factor in it.