PubMed Health⌕ Search

Biomedical subjects

V I Kazakov

Publications and source records attributed to V I Kazakov.

At least 19 recordsLinked to original sources

[Variation of microsatellites BM224 and Bcal7 in populations of green toads (Bufo viridis complex) with various nuclear DNA content and ploidy].

We studied variation of microsatellites BM224 and Bcal7 in three species of the Bufo viridis diploid-polyploid complex. We found that locus Bcal7 in all examined samples was monomorphic. Three alleles of microsatellite BM224 were found. Among tetraploid toads, the western species B. oblongus had only one allele variant, whereas the eastern species B. pewzowi had two other alleles. Similar distribution of alleles was observed in triploid specimens, collected in the area borders of tetraploid and diploid species. Among samples of diploid toad B. viridis, we found all three allele variants of microsatellite BM224. Their distribution was geographically determined. A comparison of allele distribution with genome size variation in diploid toads showed very similar patterns.

Africa, Northern↗

[Distribution of satellite DNA TkS1 in genomes of salamanders (Salamandridae)].

Genomes of 22 species and subspecies of salamandrids (Triturus, Cynops, Neurergus, Notophthalmus, Pachytriton, and Pleurodeles ) were studied. Satellite TkS1 (32-33 bp) was found in all examined species, both in direct and reversed orientations. The use of single-primer PCR with oligonucleotides, which are homologous to the most conservative part of satellite TkS1, allowed us to reveal DNA fragments, flanked by single copies (or small tandem repeats) of satellites TkS1 having various (5' and 3') orientation. Such fragments were observed in Pleurodeles waltl, Triturus a. alpestris, T. vulgaris lantzi, T. v. vulgaris, Neurergus crocatus and T. vulgaris graecus. The length of amplified DNA fragments in three subspecies of T. vulgaris differed. This might be connected with unequal amounts and different distribution of 5' and 3' copies of satellite TkS1 in their genomes. Patterns of DNA amplification in Triturus a. alpestris and Neurergus crocatus were quite similar. Only two species (Triturus a. alpestris and T. v. vulgaris) had approximately equal amounts and similar distribution of 5' and 3' copies of satellite TkS1 in their genomes.

Animals↗

[Insertion-deletion polymorphism of the angiotensin converting enzyme gene and its relationship to serum levels of free amino acids in the patients with connective tissue dysplasias].

An association between insertion/deletion polymorphism (IDP) of the Alu repeat in intron 16 of the angiotensin I-converting enzyme (ACE) gene and the serum free amino acid levels in the patients with connective tissue dysplasias was examined. Genotyping of 102 patients (25 II, 51 ID, and 26 DD) was performed using PCR. Serum free amino acids levels in these patients were determined by use of HPLC technique. A statistically significant increase of the leucine-isoleucine (P < 0.05) and phenylalanine (P < 0.01) levels in deletion homozygous patients (DD) relative insertion homozygous (II) patients was observed. The differences in respect of other amino acids were not detected. These findings point to the importance of registration of IDP in the ACE gene at dietary therapy of such patients, as well as in the individual choice of medical preparations containing the amino acids mentioned.

Adolescent↗

The angiotensin converting enzyme I/D polymorphism in Russian athletes.

The deletion (D) allele of the human ACE gene is associated with higher ACE activity than the insertion (I) allele. There is controversy as to whether the ACE genotype may be associated with elite athletic status; recent studies have identified no significant associations amongst those drawn from mixed sporting disciplines. However, such lack of association may reflect the mixed nature of such cohorts, given that an excess frequency of the I allele has been reported amongst elite endurance athletes, and an excess of the D allele amongst those engaged in more power-orientated sports. We examined this hypothesis by determining ACE I/D allele frequency amongst 217 Russian athletes (swimmers, skiers, triathletes and track-and-field participants) prospectively stratified by performance ('outstanding' or 'average'), and the duration of their event (SDA (<1 min), MDA (1 to 20 min), and LDA (>20 min): short, middle and long distance athletes respectively). ACE genotype and allele frequencies were compared to 449 controls. ACE genotype frequency amongst the whole cohort, or the outstanding athletes alone, was no different to that amongst sedentary controls. However, there was an excess of the D allele (frequency 0.72, P=0.001) amongst the outstanding SDA group, and an excess of the I allele (frequency 0.63, P=0.032) amongst the outstanding MDA group. These findings were replicated in the outstanding swimmers, with track and field SDA similarly demonstrating an excess of the D allele (P=0.01). There was no association found between the outstanding LDA and ACE genotype (P=0.27). These data not only confirm an excess of the D allele in elite SDA, and I allele in elite MDA, but also offer an explanation as to why any such association may be hard to detect amongst a heterogeneous cohort of mixed athletic ability and discipline.

Adult↗

[Stress-induced DNA fragmentation in cardiomyocytes of MDX and C57Bl mice].

The study deals with apoptosis of cardiomyocytes of adult mdx mice. Our previous investigation of the total DNA from mdx mice myocardium in 0.5% agarose and 5% PAAG revealed middle sized DNA fragments about 64 kb only. The DNA electrophoresis in 5% PAAG after alpha-32P-dATP incorporation into DNA, fragments mediated by terminal transferase, showed no presence of smaller DNA fragments. The low size DNA fragments (0.2, 0.4 and 11.0 kb) were observed only following stress (a 5 min swimming in water bath) by means of alpha-32P-dATP incorporation mediated by TdT reaction. DNA fragmentation lasted for 48 h after the stress. A study of the total DNA extracts of C57B1 mice also demonstrated middle and low molecular sized DNA fragmentation 2 h after the stress under the same condition of the experiment. But during the next 48 h the signs of DNA fragmentation of the total DNA disappeared. The authors conclude that the first stage of apoptosis is a permanent property of cardiomyocytes of mdx mice.

Animals↗

[Parameters of lipid metabolism and polymorphism of apolipoprotein aI and angiotensin-converting enzyme genes in patients with endometrial carcinoma].

Data on lipid metabolism in 109 cases of endometrial carcinoma and 33 patients in control are presented. Relevant disorders were detected in 72.5% of the study group [stage I obesity--23 (21.1%); II--29 (26.6%); III--25 (22.9%); IV--2 (1.9%)] which was 1.5 times the mean level in controls (51.5%). The abdominal pattern of obesity was predominant (77.7%). Symptoms of cardiosclerosis were identified in 93 patients with endometrial tumors (85.3%), 93.5% of the latter group presenting with concomitant hyperglyceridemia. In 68.8% of endometrial carcinoma patients, incidence of arterial hypertension was higher than in controls (54.5%). Lipoproteins played a major role in dyslipoproteid pathogenesis involved in obesity and high blood pressure. A study of the insertion-deletion (I/D) polymorphism of apolipoprotein AI genes showed two deletion alleles (DD--6%) and one heterozygote (ID--3%) in control group; no deletion alleles were identified in endometrial tumor patients (0.1 (p(0.05). An investigation of the I/D polymorphism of angiotensin-converting enzyme genes identified deletion homozygotes in 30, insertion homozygotes (II)--27, and heterozygotes--41% (control). In endometrial cancer group, the deletion allele distribution was: DD--29; II--28 and ID--45%. Deletion allele frequency in control was 0.485 while in endometrial carcinoma--0.484 (p(0.05), i.e. with out significant difference.

Apolipoprotein A-I↗

[Intracellular localization of cycloferon, its binding with DNA and stimulation of cytokines expression after exposure to cycloferon].

Despite the wide usage of immunomodulating preparates including interferon inducers in medical practice little is known about their mechanism of action. We investigated some theoretical aspects of action of potent interferon inducer--cycloferon (10-carboxymethyl-9-acridanone), such as intracellular localization, ability to DNA binding and cytokine expression stimulation. This preparate has been found to be localized in nuclei of monocytic cells U-937, T- and B-lymphocytes and HeLa cells. In Hep-2 line cycloferon was bound to cells from non-adhesive subpopulation and was not detected in cells of monolayer. Human fibroblasts did not bind the substance. Interaction with double-stranded but not with single-stranded DNA occurred at pH lower than 4.7 regardless of the GC-contain. As shown by dot-hybridization cycloferon stimulated the transcription of interferon-alpha gene in U-937 cells 29-44-fold compared to the control but did not affect the transcription of tumor necrosis factor and interleukin-2 genes. Our data allow to propose that some specific receptor exists in cell with affinity to cycloferon.

Acridines↗

[Apoptosis and DNA degradation of cardiomyocytes of mdc and C57Bl mice].

DNA destruction and apoptosis of ventricular cardiomyocytes were studied using DMX and C57Bl10/J mice. According to our electron microscope observations the cardiomyocyte nuclei undergo chromatin condensation with the nuclear membrane folding. In cardiomyocytes with significant nuclear destruction, structural disturbances in the cytoplasm are also seen. The 0.5% agarose gel electrophoresis reveals DNA fragments, sized 64 kb and more, inside the total DNA of MDX mice myocardium. No kinds of DNA fragments are available inside samples of the total DNA of C57Bl mice myocardium. Swimming during 5 min induces formation of the same type of DNA fragments inside the total of DNA of C57Bl mice myocardium, which was registered after 2 and 22 hours of the experiment. The DNA fragments disappear from the total C57Bl mice myocardium DNA within 48 h after the stress. Trypan blue evokes formation of the same 64 kb fragments inside DNA of myocardium within 24 h after injection to C57Bl mice. Electrophoresis of the total DNA with 2% agarose gel or 5% PAAG revealed no DNA samples analysed during this study. The authors conclude that DNA destruction and apoptosis characteristic features of MDX mice cardiomyocytes of mice, have a common mechanism of DNA degradation that works both after the stress of trypan blue action in case of C57Bl mice, and as a consequence of dystrophin absence in cardiomyocytes in the case of MDX mice.

Animals↗

Increased concentration of some transcription factor binding sites in human retroposons of the Alu family.

Eukaryotic gene expression is dependent on short protein-binding DNA sequence motifs promoting the assembly of multiprotein transcription complexes. Human retroposons of the Alu family are known to contain some high-affinity binding sites for transcription factors, which may serve as signals in regulation of expression of RNA-polymerase II-transcribed genes. In this computer study we have compared the density of ten consensus transcription factor binding sites in a set of human mature mRNA, human promotors and Alu repeats. Our results indicate that Alu retroposons and promotor sequences have significantly higher mean density of these sites compared to RNAs. It is suggested that the majority of Alu repeats do have the potential for regulating gene expression via modulation of RNA polymerase II-dependent transcription.

Base Composition↗

[The physical mapping of human chromosomes. II. The production of unique chromosome-specific DNA fragments using the polymerase chain reaction with oligonucleotide primers to conservative regions of Alu repeats].

Unique DNA fragments localised between Alu-repeats have been produced by PCR. The reaction was carried out with oligonucleotide primers to conservative regions of Alu-repeats. The DNA fragments from different pulls, individual clones, chromosome-specific clonotecs derived from phage lambda, cosmids and individual human chromosomes served as matrixes. The possibilities are discussed of Alu-primer applying in production of exceptional physical features of DNA molecules, suitable for constructing clone couple groups and for direct physical mapping on the DNA of isolated chromosomes, missing the stage of cloning.

Base Sequence↗

[The structure of Alu-like DNA nucleotide sequences in cyclostomes and fishes].

By methods of DOT hybridization and polymerase chain reaction (PCR) structures similar to Alu repeats were shown in the genome of fish and lamprey. The fact of the presence of such sections in representatives of many orders of fishes, and also our experimental data allow to suppose that Alu-like structures, similar to 3' region of Alu repeats on mammals, have been already formed in these. The evolutionary significance of described structures has been supposed.

Animals↗

[Extracellular DNA in the blood of pregnant women].

The level of extracellular DNA increases in the blood of women during pregnancy. By means of PCR, the full-size Alu repeats were observed among extracellular blood DNA repeats of pregnant women. Furthermore, with Tc65 type primer the PCR method allowed to observe in the blood DNA fragments flanked by inverted Alu repeats (inter Alu repeats). The presence of such a type of inter Alu repeats was estimated in the blood of women being in the first trimester of pregnancy only, but was not estimated among blood DNA fragments of women of the last trimester of pregnancy. It is discussed which types of cells may serve as a source of extracellular blood DNA (either trophoblast cells, lymphocytes, or decidual cells), the significance of such DNA for pregnancy being appreciated.

Base Sequence↗

[The physical mapping of human chromosomes. The use of the polymerase chain reaction on unique DNA sequences with a known location on chromosome 3].

16 pairs of oligonucleotide primers, complementary to unique DNA sequences of human chromosome 3, were synthesized. For 10 of these, fragments of expected length were generated in polymerase chain reaction (PCR). These fragments may be used as markers for detailed physical mapping of this chromosome. The above primers were used in PCR in order to analyse a hybrid mice-human cell line which contained presumably a fragment of human chromosome 3. The presence of human DNA in the hybrid line has been shown, but no ultimate evidence was received to confirm its location in human chromosome 3. By means of primers, complementary to the butyrylcholinesterase gene (BCHE), pools of clones from the yeast total library of human DNA were analysed, and then the pool and later the individual [correction of undividual] clone, containing a fragment of BCHE gene, were identified.

Base Sequence↗