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Biomedical subjects

V V Nosikov

Publications and source records attributed to V V Nosikov.

At least 19 recordsLinked to original sources

[Distribution of alleles of microsatellite loci HUMCYAR04 and D19S253 in population samples of two Russian cities].

In population samples of Moscow and Tomsk, allelic polymorphism of microsatellite loci HUMCYAR04 and D19S253 was studied by polymerase chain reaction. Seven HUMCYAR04 alleles (181-205 bp) and nine alleles (208-240 bp) of the D19S253 locus were identified. In both population samples, the absence of statistically significant differences in the distribution of allele frequencies for these loci was demonstrated. The distribution of the observed genotype frequencies was shown to correspond to the Hardy-Weinberg equilibrium in both populations. Mendelian inheritance of these tandem repeats was demonstrated by an analysis of two large families. The parameters of polymorphism information content for the loci studied were determined; comparative analysis of allele frequencies with corresponding data for a number of populations was performed. These short tandem repeats were proposed for use in personal identification and paternity tests.

Alleles

Frequency analysis of HLA-DQA1 and HLA-DQB1 gene alleles and susceptibility to type 1 diabetes mellitus in Russian patients.

The HLA-DQA1 and DQB1 genes have recently been recognized to be strong genetic markers of susceptibility to type 1 (insulin-dependent) diabetes mellitus. The Arg52 DQA1 and non-Asp57 DQB1 alleles of these genes correlate with the disease predisposition and the Asp57 DQB1 and non-Arg52 DQA1 alleles with disease protection. We investigated 113 patients with type 1 diabetes and 121 healthy subjects from the Russian population of Moscow using DNA amplification and dot-blot hybridization with sequence-specific oligonucleotides (SSO). Using conventional statistical methods we confirmed previous observations indicating the important role of the above-mentioned amino acid residues in susceptibility and resistance to type 1 diabetes. Relative risk values for all alleles and absolute risk for carriers of most predisposing allele combinations were calculated. The absolute risk for carriers of DQA1 and DQB1 gene alleles allowing for the formation of four possible 'diabetogenic' heterodimers on the surface of immunocompetent cells, regardless of the type of coding (cis or trans), was 2.54%, which is 13 times greater than the background risk for the Russian population--0.2% up to 30 years of age.

Adolescent

Clinical significance of HIV DNA in polymorphonuclear neutrophils from patients with HIV infection.

HIV DNA was detected by the polymerase chain reaction technique in polymorphonuclear neutrophils (PMNs) in 11 of 37 (29.7%) HIV-infected patients. A detectable level of HIV DNA in PMNs was more common in symptomatic than asymptomatic HIV infected patients (46.7% and 18.2%, respectively; p < 0.05). HIV DNA in PMNs was detected most frequently in patients with recurrent bacterial pneumonia or Pneumocystis carininii pneumonia. An association between HIV DNA in PMNs and a low CD4/8 ratio as well as high levels of immunoglobulins in the sera was noted. Detectable HIV DNA was found more frequently in patients with neutropenia than in those with a normal level of neutrophils in peripheral blood (44.4% and 28.0%, respectively; p < 0.05). These data suggest that infection of PMNs by HIV may be associated with PMN impairment during HIV infection.

Adult

[Assessment of interleukin-1 beta mRNA expression in the norm and pathology].

We investigated cytoplasmic RNA from the peripheral blood cells of pollinosis patients. Increased levels of IL-I mRNA were registered in neutrophils of patients suffering from pollinosis for a long time. Neutrophils from patients at the time of exacerbation of pollinosis responded to stimuli less than the cells from healthy donors. During remission the activated neutrophils from pollinosis patients and those from healthy donors had same levels of IL-I mRNA.

Cytoplasm

[Evaluation of the activity of cytokine genes--a new diagnostic test in immunology].

The increased level of IL-1 mRNA was discovered in neutrophils of patients suffering from pollinosis for a long time and responding poorly to specific immunotherapy. Moreover, neutrophils from patients with exacerbation of pollinosis responded to stimuli less than cells from healthy donors. In remission, the activated neutrophils from pollinosis patients and healthy donors had the same levels of IL-1b mRNA. Tumor necrosis factor alpha expression was unchanged in neutrophils of pollinosis patients. Changes in the status of cells from patients were detected with a simple procedure of dot hybridization. Peripheral blood cells were used as available material. This allows one to hope that the approach can be used for analyzing the patients' immune status in choosing the treatment course as well as for controlling the treatment effect.

Cells, Cultured

Cell differentiation as assayed by the topography and number of ribosomal genes.

In situ hybridization, Ag-staining and electron microscopy were used to study the distribution of ribosomal genes in isolated nuclei of rat cerebellar cells and the correspondence of the ribosomal genome topography to the nucleolar structure. rDNA-DNA autoradiography revealed clusters of silver grains, as well as diffuse groups and rows. The cluster frequencies corresponded to the frequencies of nucleoli on Ag-stained slides. Competitive hybridization in situ using unlabelled rat rRNA and hybridization with a nonspacer rDNA fragment showed that the diffuse groups and rows of grains also correspond to the ribosomal genes. Spatial organization of the ribosomal genome in the Purkinje cells differs from that in the other cerebellar neurons and glial cells. A 1.5-fold redundancy of the ribosomal genes was found in some Purkinje cells, while most of these as well as microneurons contained the diploid value of the genes.

Animals

The energetics of the B-Z transition in DNA.

The paper deals with the energetics of the transition to left-handed Z form in DNA with an arbitrary base sequence. There is a brief outline of the statistical-mechanical model of the B-Z transition allowing for three possible states of each base pair. The parameters of the model can be determined by comparing the theory with experimental data for the B-Z transition in inserts with given sequences in circular DNA. The model contains six energy parameters, most of which have been determined before. In order to find the remaining parameters of the model and test its adequacy, a number of oligonucleotide sequences were synthesized and inserted into the pUC 19 plasmid. Two-dimensional gel electrophoresis was used to determine the superhelical density at which the inserts adopt the Z form. A statistical-mechanical treatment of these data yielded a complete set of six energy parameters for the B-Z transition. The theoretical assumption that the free energy of Z-form pairs does not depend on the type of adjacent pairs proved to be in agreement with the experimental data.

Chemical Phenomena

Nucleotide sequence analysis of the spacer regions flanking the rat rRNA transcription unit and identification of repetitive elements.

We investigated the organization of the rat rDNA non-transcribed spacer (NTS) by determining the sequence of large NTS segments located upstream (2501 bp) and downstream (4025 bp) from the rRNA transcription unit. We identified four B2-like and two ID mobile elements. They may be grouped in three pairs with the members of each pair located in the upstream and downstream NTS. The ID sequences are identical to the consensus sequence, while the pairs of B2-like elements show 85% and 50/65% homology to the consensus B2 sequence. The proximal part of the downstream NTS contains a region of widely diverged SalI tandem repeats. A considerable part of the analyzed upstream and downstream NTS sequences is constituted by different types of simple sequences and long poly(purine) X poly(pyrimidine) tracts. These data show that the rat rDNA NTS regions flanking the rRNA transcription unit are characterized by a combination of short interspersed (B2-superfamily) and various simple sequences.

Animals

[Intra- and interpopulation heterogeneity of the cerebellar nerve cells in topography and ribosomal gene content].

Using the method of in situ hybridization of ribosomal DNA with DNA of isolated nuclei, a study was made of localization and relative content of ribosomal genes in the Purkinje cells and other cells of the rat cerebellum. It has been shown that various cells of cerebellum have, on the average, the same number of ribosomal genes. A subpopulation with amplified ribosomal genes have been found among the nuclei of Purkinje's cells.

Animals

Nucleotide sequences in human chromosomal DNA from nonhepatic tissues homologous to the hepatitis B virus genome.

DNA extracted from human nonhepatic tissues (placenta and kidney) have been digested with restriction endonucleases and examined by the Southern procedure with cloned 32P-labelled DNA of hepatitis B virus (HBV). In placental DNAs of women with the history of a hepatitis B infection and in one out of four cases of patients with no known HBV exposure or manifestation, HBV-related chromosomal nucleotide sequences were detected. The integration of HBV-related sequences was observed also in human kidney DNA. Moreover, in the placenta of women who had hepatitis B infection prior to delivery, unusual unintegrated forms of HBV have been found. We conclude that HBV sequences can be found not only in hepatic tissue but also in placental and kidney DNA, both of HBV-exposed and in one case even of a nonexposed patient.

Base Sequence

Structural organization of rat ribosomal RNA genes: interspersed sequences and their putative role in the alignment of nucleosomes.

We have observed four regions containing highly repetitive interspersed sequences in the nontranscribed spacer (NTS) of the rat rRNA genes. Two of them (A and B) are located at a distance of 3-5 kb upstream from the transcription start point and two others (C and D) at a distance of 2-5 kb downstream from the 3' end of the 28S rRNA gene. These repetitive sequences are widely dispersed in the genome and are included both in small-copy regions and in the families of extended reiterated sequences. The sequences of three fragments were determined: one from the C2 region, 1100 bp in length and two from A and C1 regions, 110-120 bp long. These regions are characterized by the presence of 'simple' sequences, such as (AC)n, (ACC)n, (GAG)n, (GGGA)n, (TAAG)n, and also of long blocks, (G)n and (A)n. In the C2 region two palindromes, 16 and 14 nt long, were found, one of them including a XhoI site. Mobile element B2 was observed in regions B and C. All four regions, A, B, C and D, contain sets of simple sequences, among which some common elements have been found. Theoretical prediction of the nucleosomal disposition in the C region indicates that the combination of simple sequences existing in the given area secures fixed positions of the nucleosomes, one of the nucleosomes being formed on the B2 element. Moreover, a striking periodicity, with the repeat length close to that of the rat nucleosomal DNA, has been observed. A hypothesis is put forward that the simple sequences can dictate the location of nucleosomes on the adjoining DNA sequences, thereby regulating the gene activity.

Animals