Efficacy of enterocin S760 in treatment of mice with anthrax infection due to Bacillus anthracis M-71

The therapeutic efficacy of enterocin S760, a broad spectrum antimicrobial peptide produced by Enterococcus faecium LWP760 was tested on mice infected with Bacillus anthracis M-71 to induce anthrax (second Tsenkovsky's vaccine). Intraperitoneal four-, two- or one-fold administration of the peptide in a dose of 25 mg/kg for 10 days for prophylactic (1 hour after the contamination) and therapeutic (24 hours after the contamination) purposes prevented or cured the infection in 90-100% of the mice versus the 100-percent lethality in the control (untreated animals). The antimicrobial activity of enterocin S760 against B. anthracis M-71 in vivo correlated with activity in vitro. Enterocin S760 is considered a novel promising antimicrobial for the treatment of grampositive and gramnegative infections.     

Copper-catalyzed cleavage of DNA by arenes

DNA was found to be cleaved in neutral solutions containing arenes and copper (II) salts. The reaction is comparable in efficiency with the DNA cleavage by such systems as Cu(II)-phenanthroline and Cu(II)-ascorbic acid, but, in contrast to the latter, the system Cu(2+)-arene does not require the presence of an exogenous reducing agent or hydrogen peroxide. The system Cu(2+)-arene does not cleave DNA under anaerobic conditions. Catalase, sodium azide, and bathocuproine, which is a specific chelator of Cu(I), completely inhibit the reaction. The data obtained allow one to suppose that Cu(I) ions, superoxide radical, and singlet oxygen participate in the reaction. It has been shown by the EPR method using spin traps that the reaction proceeds with formation of alkoxyl radicals, which can insert breaks in the DNA molecule. For effective cleavage of DNA in the Cu(II)-o-bromobenzoic acid system, the radicals have to be generated by a specific copper-DNA-o-bromobenzoic acid complex, in which copper ions are most probably coordinated with oxygen atoms of the DNA phosphate groups. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2003, vol. 29, no. 6; see also http://www.maik.ru.     

The experience of FISH technique application for reconstruction of individual radiation doses in Chernobyl liquidators in the framework of Ukrainian-American project "Leukemia"

The results of proper investigations received under the cytogenetic examination of 225 persons (control groups, Chernobyl liquidators exposed to different radiation doses, oncogematology patients) had been summarized and analyzed. The conclusion concerning possibilities and limitations of FISH technique usage for retrospective biodosimetry of human radiation exposure has been presented.     

A new electrometric approach to studying specific biomolecular complexes

In the article the results of the influence of some types of biological molecules and their specific immune complexes on the volt-amperic characteristics of surface-barrier contact structures with the super thick metal film are presented. Moreover, the possibility to develop on this basis a simple instrumental method for separate registration of initial components and products of their interaction is discussed. It was shown that the volt-amperic characteristics of surface-barrier structures of Ni-Si changed at the deposition of myoglobin and its specific monoclonal antibodies. These structures more essentially reacted to the formed presence of specific immune complex and, in particular, to the direct formation of this complex on the surface at the subsequent use of the initial immune components in comparison with their separate presence. For all investigated types of biological molecules and their specific complexes we found optimal thickness of metal film when changes of volt-amperic characteristics of system achieved maximum level. It was concluded that this electrometrical method was suitable for the express and separation free registration of specific immune complex.     

Marine fungus Stilbella aciculosa as a potential producer of prostaglandins

The amount and composition of fatty acids in the fungus Stilbella aciculosa associated with the marine macroorganism Apostichopus japonica (trepang) were determined by gas-liquid chromatography and gas chromatography-mass spectrometry. In the culture liquid of S. aciculosa, prostaglandins (PG) of groups E and F were revealed by UV spectroscopy. This finding was confirmed by the presence of direct precursors of PG, polyunsaturated eicosapentaenoic and docosahexaenoic acids, in the culture liquid. The biomass of this fungus contained PG of group B.     

Phenotypic and genotypic identification of bacteria from the Burkholderia cepacia complex

AIM: Evaluation of the diagnostic value of pheno- and genotypic characteristics of B. cepacia strains collection. MATERIALS AND METHODS: Phenotypic and genetic methods of identification and differentiation of 25 strains of the B. cepacia complex. RESULTS: Polyphasic taxonomic approach utilizing multiple diagnostic tests was used for accurate identification of Burkholderia species. Algorithm for identification of microorganisms from the B. cepacia complex was developed. CONCLUSION: Combined use of phenotypic and molecular genetic tests, such as recA gene PCR, is recommended for differentiation of the B. cepacia complex genomovars.     

Tobacco transformants expressing antisense sequence of proline dehydrogenase gene possess tolerance to heavy metals

Analysis of resistance of genetically modified tobacco plants bearing antisense suppressor of proline dehydrogenase gene and characterized with higher content of proline to elevated concentrations of heavy metals was performed. It was demonstrated that progeny of transgenic plants have high resistance to lead, nickel and cadmium ions.     

Phylogeny of the order Rodentia inferred from structural analysis of short retrotransposon B1

A large-scale study of short retroposon (SINE) B1 has been conducted in the genome of rodents from most of the known families of this mammalian order. The B1 nucleotide sequences of rodents from different families exhibited a number of characteristic features including substitutions, deletions, and tandem duplications. Comparing the distribution of these features among the rodent families, the currently discussed phylogenetic relationships were tested. The results of analysis indicated (1) an early divergence of Sciuridae and related families (Aplodontidae and Gliridae) from the other rodents; (2) a possible subsequent divergence of beavers (Castoridae); (3) a monophyletic origin of the group Hystricognathi, which includes several families, such as porcupines (Hystricidae) and guinea pigs (Caviidae); (4) a possible monophyletic origin of the group formed by the remaining families, including six families of mouselike rodents (Myodonta). Various approaches to the use of short retroposons for phylogenetic studies are discussed.     

Ribosomal genes in inbred mouse strains: interstrain and intrastrain variations of copy number and extent of methylation

Quantitative dot hybridization was used to estimate the rDNA copy number in brain tissues of five inbred mouse strains (AKR/JY, NZB/B1OrlY, CBA/CaLacY, 101/HY, and 129/JY), which were obtained from the collection of the Research Center of Biomedical Technologies (Y). In each strain, 9-12 mice aged 1-2 months were examined. The rDNA copy number per diploid genome in strains AKR (range 105-181, mean +/- SD 136 +/- 27) and NZB (129-169, 148 +/- 12) was significantly lower than in strains CBA (172-267, 209 +/- 31), 101 (179-270, 217 +/- 30), and 129 (215-310, 264 +/- 33). Mice of strain NZB were relatively homogeneous in this trait (CV = 8.1%). Strains AKR, CBA, 101, and 129 displayed significant between-group differences, CV varying from 12.5 to 19.9%. The same DNA specimens were digested with MspI or HpaII and used to estimate the extent of methylation of the 28S rDNA region. Regardless of the strain, all mice could be classed into two groups. One group (20 mice) had a methylated fraction accounting for less than 8% of rDNA and included all nine mice of strain NZB, seven out of nine mice of strain 101, and three out of ten mice of strain 129. In the other group (29 mice), the methylated fraction varied from 18 to 38%. A possible role of methylation and the genome dosage of ribosomal genes in phenotypic variation (quantitative trait variation) of inbred mouse strains is discussed.     

Effect of oxidative stress inductors on the photosynthetic apparatus in cyanobacterium Synechocystis sp. PCC 6803 Prq20 mutant resistant to methyl viologen

The damaging effect of oxidative stress inductors: methyl viologen, benzyl viologen, cumene hydroperoxide, H2O2, menadion, and high irradiance on the photosynthetic apparatus of cyanobacterium Synechocystis sp. PCC 6803 in cells of the wild type strain and the methyl viologen-resistant Prq20 mutant with the disrupted function of the regulatory gene prqR has been investigated by measuring the delayed fluorescence of chlorophyll a and the rate of CO2dependent -O2 gas exchange. It has been shown that the damage to the photosynthetic apparatus in the Prq20 mutant as compared with the wild type was less in the presence of methyl viologen and benzyl viologen. Reasons for the enhanced resistance of the photosynthetic apparatus in the mutant Prq20 to methyl viologen and benzyl viologen are discussed.