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Biomedical subjects

A N Suvorov

Publications and source records attributed to A N Suvorov.

At least 19 recordsLinked to original sources
PubMed2005

Analysis of recombinant group B streptococcal protein ScaAB and evaluation of its immunogenicity.

Group B streptococcal (GBS) gene encoding the putative lipoprotein and adherence factor ScaAB was cloned and expressed in E. coli. Recombinant ScaAB protein was isolated. Signal sequence of ScaAB was found to be cleaved in the E. coli host. ScaAB recombinant protein was immunogenic in mice and antibodies against this protein were discovered in mice sera after GBS infection. The perspectives of the use of ScaAB protein in GBS vaccine are discussed.

Amino Acid Sequence↗
PubMed2005

Effect of VEGF on mouse thymocyte proliferation and apoptosis in vitro.

Vascular endothelial growth factor is not only angiogenic, but also immunoregulatory factor. For evaluation of the possibility of its direct interaction with mouse thymocytes we studied the effect of vascular endothelial growth factor on proliferation and apoptosis of thymocytes and expression of genes for the corresponding receptor on these cells. Vascular endothelial growth factor modulated mitogen-induced proliferation of thymocytes and stimulated spontaneous apoptosis in intact thymus cells. Thymocytes express mRNA of type 2, but not type 1 vascular endothelial growth factor receptors.

Animals↗
PubMed2002

[Study of IS-elements aimed at establishing a degree of the relationship of multiple-serotype Streptococcal strains of group B].

The presence and restriction fragment length polymorphism of IS 861 and IS 1548 were analyzed among 113 streptococcal strains of group B. 13 strains were found to possess both IS 861 and IS 1548, 54 strains were found to possess only IS 861, and 46 strains had neither IS 861 nor IS 1548. 9 HindIII and 6 EcoRI restriction patterns, hybridizing correspondingly with IS 861 and IS 1548, were discovered. A certain correlation between IS 1548 and IS 861 hybridizing patterns, on the one hand, and restriction patterns, found by pulse-electrophoresis, on the other hand, was established. It was demonstrated that restriction fragment length polymorphism of IS 1548 and 861 can be used to evaluate the degree of relationship between the strains.

Animals↗
PubMed2001

Complete genome sequence of an M1 strain of Streptococcus pyogenes.

The 1,852,442-bp sequence of an M1 strain of Streptococcus pyogenes, a Gram-positive pathogen, has been determined and contains 1,752 predicted protein-encoding genes. Approximately one-third of these genes have no identifiable function, with the remainder falling into previously characterized categories of known microbial function. Consistent with the observation that S. pyogenes is responsible for a wider variety of human disease than any other bacterial species, more than 40 putative virulence-associated genes have been identified. Additional genes have been identified that encode proteins likely associated with microbial "molecular mimicry" of host characteristics and involved in rheumatic fever or acute glomerulonephritis. The complete or partial sequence of four different bacteriophage genomes is also present, with each containing genes for one or more previously undiscovered superantigen-like proteins. These prophage-associated genes encode at least six potential virulence factors, emphasizing the importance of bacteriophages in horizontal gene transfer and a possible mechanism for generating new strains with increased pathogenic potential.

Bacteriophages↗
PubMed2000

Replication origin of Streptococcus pyogenes, organization and cloning in heterologous systems.

The origin of DNA replication (oriC) of Streptococcus pyogenes, group A streptococci (GAS), has been cloned in Escherichia coli and reintroduced by transformation into other GAS strains. Transformation frequencies into GAS strains with oriC-carrying plasmids occurred with unusually high frequencies. However, the oriC-containing plasmids in the new recipients were found to be unstable and had a tendency to integrate into the chromosome, even when a recA GAS strain was used as a recipient. The GAS oriC was able to direct the replication of autonomous plasmids in group B streptococcal recipients. The chromosomal organization of the oriC region of GAS relative to other bacterial species appears to be similar to oriC of Bacillus subtilis and other Gram-positive microorganisms.

Amino Acid Sequence↗
PubMed2000

[The use of therapeutic/prophylactic dragee "honey laminolact" in radiotherapy of uterine tumors].

The study deals with the effect of a newly-developed food product--Honey Laminolact, containing live lactic acid bacteria, amino acids, trace elements, fruit pectine and immunomodulators-on the degree of response to radiation in 44 patients who received radiotherapy for uterine tumors. It was shown to lower response of the intestinal tract to radiation when the small pelvis was exposed.

Adjuvants, Immunologic↗
PubMed1998

[Genetic analysis of pathogenic streptococci groups A and B].

The study deals with the genetic mapping of chromosomal DNA of groups A (AS) and B (BS) pathogenetic Streptococci. Its stages are presented and considered. The maps of these microorganisms are compared. A collection of epidemic AS and BS was analyzed by employing pulsed field gel electrophoresis. AS and BS were found to show heterogeneity of DNA sequences and the common pattern of gene location on the chromosomes.

Child↗
PubMed1997

Cloning of the glutamine synthetase gene from group B streptococci.

The glnA gene from the human pathogen Streptococcus agalactiae was cloned from a genomic library prepared with the lambda phage vector lambdaDASHII. A 4.6-kb DNA fragment of one of the recombinant phages was subcloned in pUC18. This Escherichia coli clone expressed a 52-kDa protein encoded by a 1,341-bp open reading frame. The nucleotide sequence of the open reading frame and the deduced amino acid sequence shared a significant degree of homology with the sequences of other glutamine synthetases (GS). The highest homology was between our deduced protein and GS of gram-positive bacteria such as Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus. Plasmids with the cloned streptococcal glnA were able to complement E. coli glnA mutants grown on minimal media. Rabbit antisera to streptococcal GS recombinant protein recognized not only the recombinant protein but also a similar-sized band in mutanolysin extracts of all group B streptococcal strains tested, regardless of polysaccharide type or surface protein profile. The amino acid sequence of the deduced protein had similarities to other streptococcal cell-surface-bound proteins. The possible functional role of the immunological features of streptococcal GS is discussed.

Amino Acid Sequence↗
PubMed1996

Physical and genetic chromosomal map of an M type 1 strain of Streptococcus pyogenes.

A physical map of the chromosome of an M type 1 strain of Streptococcus pyogenes was constructed following digestion with three different restriction enzymes, SmaI, SfiI, and SgrAI, and separation and analysis of fragments by pulsed-field gel electrophoresis. The genome size of this strain was estimated to be 1,920 kb. By employing Southern hybridization and PCR analysis, 36 genes were located on the map.

Electrophoresis, Gel, Pulsed-Field↗
PubMed1996

[Obtaining and properties of recombinant protein G].

A gene for G protein from Streptococcus strain G148 was cloned in Escherichia coli, which gave rise to several plasmids. One plasmid containing a 1.5 kb insert coding for entire G protein with 63 kD. This protein had both an IgG binding capacity and albumin-binding activity. The second plasmid containing a 0.7 kD insert coded for protein with MM of 38 kD and had only an IgG-binding activity. The third coding for protein with 25 kD has only albumin-binding activity. After subcloning the 1.5-kb insert into the other vector pSP65 and analysing the nucleotide sequence of this insert both in pSP65 vector, the authors came to the conclusion that the proteins obtained are fusion protein of G protein and beta-galactosidase. All the proteins were prepared by affinity chromatography on IgG sepharose or on HSA sepharose. The interaction between G protein and polyclonal and monoclonal IgG of the reactions between G protein and human IgG have determined.

Blotting, Western↗
PubMed1995

Construction of a Streptococcus pyogenes recA mutant via insertional inactivation, and cloning and sequencing of the complete recA gene.

To facilitate future genetic studies with Streptococcus pyogenes (Sp), a recA mutant (Rec11) was constructed using a streptococcal integration vector carrying a PCR-derived internal recA fragment. The insertion of the plasmid in the mutant chromosome was identified by Southern hybridization. Resistance to UV and the ability to accept linear DNA transformation by Rec11 were greatly decreased, confirming its RecA phenotype. Using the PCR-derived fragment as a probe, we cloned and sequenced the complete Sp recA gene, which is highly homologous to the recA of S. pneumoniae and Lactococcus lactis.

Amino Acid Sequence↗