PubMed Health⌕ Search

Biomedical subjects

I V Smirnov

Publications and source records attributed to I V Smirnov.

At least 19 recordsLinked to original sources
PubMed2005

Antimicrobial resistance of nosocomial strains of Staphylococcus aureus in Russia: results of a prospective study.

A total of 879 Staphylococcus aureus clinical isolates from 17 medical institutions in different regions of Russia were tested. Susceptibility to 18 antimicrobials was determined by agar dilution in accordance with the NCCLS recommendations. The most potent antimicrobials were glycopeptides, linezolid, and fusidic acid, to which no resistance was found. Other antimicrobials with low frequency of non-susceptibility were mupirocin (0.3%), trimethoprim/sulfamethoxazole (0.8%), quinupristin/dalfopristin (1.8%) and rifampicin (7.0%). Fluoroquinolones displayed moderate activity (5.8% of non-susceptible strains to moxifloxacin, 9.1% to levofloxacin, 13.1% to ciprofloxacin). High rates of non-susceptibility were found to clindamycin (27.1%), gentamicin (30.7%), tetracycline (37.1%), erythromycin (39.6%) and chloramphenicol (43.1%). The prevalence of oxacillin-resistant S. aureus (ORSA) was 33.5% and varied from 0% to 89.5% in different hospitals. ORSA were isolated most frequently in the burn units (77.5%), intensive care units (54.8%), trauma and orthopedics units (42.1%). This is the first multicenter study published of antimicrobial resistance of S. aureus in Russia which meets international standards.

Anti-Bacterial Agents↗
PubMed2005

[In vitro study of antiviral activity of Myramistin against measles and mumps viruses].

The study was aimed at in vitro investigation of the Myramistin antiviral activity against the measles and mumps viruses in the Vero cell culture. The experiments with addition of myramistin simultaneously or at various periods after inoculation of the monolayer by the measles virus (Edmonson strain) or mumps virus (PetroNov/03 strain) revealed pronounced dose-dependent antiviral effect of the drug. It was shown that for prevention of replication of the measles and mumps viruses the optimal concentrations were 0.05 to 0.005%. The prospects of myramistin use as a prophylactic agent for infections caused by the measles and mumps viruses are discussed.

Animals↗
PubMed1997

Effects of spermine and its cytotoxic analogs on nucleosome formation on topologically stressed DNA in vitro.

We investigated the effects of the polyamine spermine and two of its cytotoxic analogs 1,11-bis(ethylamino)-4,8-diazaundecane (BE-3-3-3) and 1,19-bis(ethylamino)-5,10,15-tirazanonadecane (BE-4-4-4-4) on the formation of nucleosomes on negatively and positively supercoiled DNA in vitro. Histones H2A, H2B, H3 and H4 were reconstituted onto DNA to form nucleosomes and the polyamines were added either before or after histone addition. The structural state of the nucleosome was monitored by analyzing the DNA topoisomers that were present after topoisomerase I treatment. Although polyamines induced DNA aggregation to various degrees. high concentrations of topoisomerase I were able to relax the aggregated DNA and the helical pitch was found to be unaltered in the aggregates. When histones were associated with negatively coiled DNA, the polyamine-induced aggregation did not alter nucleosome structure. The induced aggregate did inhibit nucleosomal transitions when examined on positively coiled DNA. BE-4-4-4-4 was most effective and BE-3-3-3 least effective. These analogs were also extremely effective in inhibiting histone deposition onto DNA. A potential mechanism for the action of these analogs is both to inhibit histone deposition during DNA replication and also disrupt nucleosomal dynamics due to aberrant chromatin condensation. These results also suggest that BE-4-4-4-4 and BE-3-3-3 may produce their cytotoxic effect through slightly different mechanisms.

Animals↗
PubMed1997

[Effect of promethazine hydrochloride (pipolphen) on the stability of R plasmid resistance in Escherichia coli].

The influence of promethazin hydrochloride (pipolphen) on stability of R plasmid inheritance in Escherichia coli strains of various serogroups was studied. The strains were isolated from patients with acute intestinal infection and from healthy persons. It was shown that in subbacteriostatic concentrations (100 to 450 micrograms/ml) pipolphen promoted elimination of the R plasmids. Decreased stability of the R plasmid inheritance was not associated with the pipolphen concentration. No influence of the drug on the biochemical characteristics, antigenic properties and nutritional requirements of the plasmid-free derivatives was detected. The eliminating action of pipolphen and ethidium bromide in some strans of Escherichia coli was shown to be different.

Drug Resistance, Microbial↗
PubMed1995

Cleavage of supercoiled plasmid DNA by autoantibody Fab fragment: application of the flow linear dichroism technique.

A highly effective method consisting of two affinity chromatography steps and ion-exchange and gel-filtration chromatography steps was developed for purification of autoantibodies from human sera with DNA-hydrolyzing activity. Antibody Fab fragment, which had been purified 130-fold, was shown to catalyze plasmid DNA cleavage. The flow linear dichroism technique was used for quantitative and qualitative studying of supercoiled plasmid DNA cleavage by these autoantibodies in comparison with DNase I and EcoRI restriction endonuclease. The DNA autoantibody Fab fragment was shown to hydrolyze plasmid DNA by Mg(2+)-dependent single-strand multiple nicking of the substrate. Kinetic properties of the DNA autoantibody Fab fragment were evaluated from the flow linear dichroism and agarose gel electrophoresis data and revealed a high affinity (Kobsm = 43 nM) and considerable catalytic efficiency (kappcat/Kobsm = 0.32 min-1.nM-1) of the reaction.

Autoantibodies↗
PubMed1995

[Antibiotic resistance of Escherichia of varying origin].

Antibiotic resistance of enteroinvasive E. coli strains (O151:K-), i.e. the levels, associations and localizations of the genetic determinants was studied. The strains were isolated in an Infants' Home. The study was performed with the comparisons to the pathogenic and ordinary E. coli strains of another origin. It was shown that the pathogenic strains were mainly resistant to streptomycin, kanamycin and chloramphenicol. The resistance was due to the R plasmids. No correlation between the pathogenic serogroup and any combination of the markers was observed. The enteroinvasive E. coli strains isolated in the Infants' Home were characterized by a one-type combination of the markers, a one-type resistance level and a one-type plasmid pattern, as well as by increased levels of the chromosomal resistance to kanamycin and streptomycin.

Child↗
PubMed1995

[Prevalence of allergic diseases in workers of industrial swine breeding].

The article presents methodic approaches to thorough occupational hygienic analysis of allergic diseases. Analyzing allergic morbidity in major swine breeding enterprise, the authors give an example of conclusion necessitating summary of clinical and immunologic results, analysis of morbidity with transitory disablement, hygienic studies orientated to forecast.

Agricultural Workers' Diseases↗
PubMed1995

[Survival of Escherichia coli in human blood serum as a function of R-plasmid content].

Thirty four strains of Escherichia coli of the pathogenic and nonpathogenic serogroups were tested for their survival in normal human blood serum as dependent on the content of the R plasmids. It was shown that the capacity for the survival of the E. coli strains of different origin was widely distributed. The value of the survival associated with the content of the R plasmids was higher in the E. coli strains of the pathogenic serogroup by comparison to that in the ordinary cultures. The capacity for the survival of the E. coli strains in the serum was more frequently accompanied by the tetracycline resistance.

Drug Resistance, Microbial↗
PubMed1994

Pretreatment with the polyamine analog 1,19-bis-(ethylamino)-5,10,15-triazanonadecane (BE-4-4-4-4) inhibits etoposide cytotoxicity in U-251 MG (NCI) human brain tumor cells.

We studied whether pretreatment of U-251 MG human brain tumor cells with the polyamine analog 1,19-bis-(ethylamino)-5,10,15-triazanonadecane (BE-4-4-4-4) affected the cytotoxicity of the topoisomerase II inhibitor etoposide. We found that BE-4-4-4-4 protected cells from the cytotoxic effects of etoposide. Possible mechanisms for this protection may be related to enhanced DNA-nuclear matrix association in analog-treated cells.

Brain Neoplasms↗
PubMed1992

DNA hydrolyzing autoantibodies.

A DNA-nicking activity was detected in the sera of patients with various autoimmune pathologies and was shown to be a property of autoantibodies. The DNA hydrolyzing activity, which was purified by affinity and high-performance liquid chromatography, corresponded in size to immunoglobulin M (IgM) and IgG and had a positive response to antibodies to human IgG. The DNA hydrolyzing autoantibodies were stable to acid shock and yielded a DNA degradation pattern that was different from that of deoxyribonuclease (DNase) I and blood DNase.

Acetates↗