PubMed Health⌕ Search

Biomedical subjects

A I Nikolaev

Publications and source records attributed to A I Nikolaev.

At least 19 recordsLinked to original sources
PubMed2005

Differential gene expression in HIV/SIV-associated and spontaneous lymphomas.

Diffuse large B-cell lymphoma (DLBCL) is more prevalent and more often fatal in HIV-infected patients and SIV-infected monkeys compared to immune-competent individuals. Molecular, biological, and immunological data indicate that virus-associated lymphomagenesis is similar in both infected hosts. To find genes specifically overexpressed in HIV/SIV-associated and non-HIV/SIV-associated DLBCL we compared gene expression profiles of HIV/SIV-related and non-HIV-related lymphomas using subtractive hybridization and Northern blot analysis. Our experimental approach allowed us to detect two genes (a-myb and pub) upregulated solely in HIV/SIV-associated DLBCLs potentially involved in virus-specific lymphomagenesis in human and monkey. Downregulation of the pub gene was observed in all non-HIV-associated lymphomas investigated. In addition, we have found genes upregulated in both non-HIV- and HIV-associated lymphomas. Among those were genes both with known (set, ND4, SMG-1) and unknown functions. In summary, we have demonstrated that simultaneous transcriptional upregulation of at least two genes (a-myb and pub) was specific for AIDS-associated lymphomas.

Journal Article↗
PubMed2004

[Analysis of the formation and autonomous replication of an extrachromosomal mouse transgene].

A stable autonomously replicating shuttle transgene, pr8a was, previously isolated from Bombix mori and characterized. Autonomous replication of pr8a and its derivatives was observed in yeast cells, B. mori embryos, and transgenic mice. To continue the previous studies, transgenic mice of several generations were examined. DNA analysis revealed a course of pr8a rearrangements resulting in extrachromosomal transgene p8-2 of F2 transgenic mice. Consecutive directional elimination of vector DNA fragments was characteristic of rearrangements affecting autonomous transgenes in mouse cells. Analysis of the data obtained with transgenic mice and other organisms made it possible to identify the pr8a fragment that acts as minimal ARS in transformed yeast cells and transgenic mice. Another pr8a region was assumed to be a component of a pr8a ARS module involved in regulating autonomous replication. Inserted in two different integrative vectors, minimal ARS ensured their autonomous state in transformed yeast cells and transgenic mice. Transgenes pr8a and p8-2, along with some other well-known constructs, were considered as prototype autonomously replicating vectors suitable for studying the mechanism of autonomous replication and solving some problems of gene therapy.

Animals↗
PubMed2001

[ARS-activity of a DNA fragment from Bombyx mori in Saccharomyces cerevisiae cells].

A previously cloned autonomous transgene (pr8a) of silkworm Bombyx mori inherited without changes in the structure was used to clarify the activity of its ARS in yeast cells. ARS of pr8a was also shown to maintain autonomous replication of hybrid plasmids in yeast cells. The same was true for its central 2.4-kb fragment devoid of flanking sequences.

Animals↗
PubMed2001

[Comparative analysis of the level of gene transcription in two types of HIV-associated lymphoma].

In order to characterize the molecular mechanisms of lymphoma formation in HIV-infected humans, a method of two-staged substractive cloning was used, which adequately detects genes whose expression is increased in cells of one lymphoma in comparison with another. Using this method, we determined the spectrum of genes whose expression was increased in centroblastic non-Hodgkin's lymphoma in comparison with immunoblastic non-Hodgkin's lymphoma. Several gene groups were distinguished in this spectrum; their probable involvement in lymphogenesis is discussed.

DNA, Complementary↗
PubMed2000

Differential gene expression in B-cell non-Hodgkin's lymphoma of SIV-infected monkey.

Infection with SIVmac251 in some rhesus monkeys (Macaca mulatta) leads to B-cell non-Hodgkin's lymphomas (B-NHL) clinically similar to that of HIV-infected AIDS patients. To further characterize the SIV-associated B-NHL we have generated genetic profiles of malignant cells by subtractive hybridization and Northern blot analysis. We have analyzed 21 clones of a subtracted cDNA library corresponding to overexpressed genes in diffuse large B-cell (DLBCL) SIV-associated monkey lymphoma. Eight of these clones represent a sequence homologous to an abundant transcript from KG-1 cells originally established from a human myelogenous leukemia. The protein encoded has a 60% similarity to a hypothetical glycine-rich transmembrane signal protein of Caenorhabditis elegans and 25% similarity to the ret finger protein. The other cDNA clones contained sequences of the serum amyloid A gene (SAA), the alpha1-acid glycoprotein gene (AGP), the ribosomal protein S3a (RPS3a) and L8 (RPL8) genes, the interferon-inducible gene (INF-ind), the metastasin gene (mts1), and the NADH dehydrogenase I gene (ND-I). The remaining cDNA clones consisted of yet unknown sequences. In addition, we detected an up-regulation of the cytochrome c oxidase II gene (COX-II), the ND-IV gene, and the SET oncogene by Northern blot hybridization in three SIV-associated NHLs of different histomorphological classification. All these genes have not previously been found to be overexpressed in B-NHL.

Animals↗
PubMed1999

[The cytological indices and electrokinetic mobility of the cell nuclei of the buccal epithelium in assessing periodontal status].

Study of electrokinetic mobility of buccal epitheliocyte nuclei, nonspecific resistance of buccal mucosa cells, and cytograms of patients with periodontitis of different severity revealed a clear-cut correlation between these parameters and severity of clinical picture of periodontal inflammation. Morphological and cytological studies of buccal epithelial cells are proposed to be used for assessing the severity of periodontal inflammation and the efficacy of therapy.

Cell Nucleus↗
PubMed1993

Preferential extrachromosomal localization of exogenous DNA in transgenic silkworm Bombyx mori L.

Transgenic silkworms (Bombyx mori L.) were obtained by microinjection of plasmid pPrC-LTR1.5, which carris 1.5 DNA copies of Rous sarcoma virus (RSV) long terminal repeats (LTRs) inserted in the vector pBR322. The transgene was transmitted over the three generations obtained up to now. Most of the exogenous DNA failed to integrate into the genome and persisted as an extrachromosomal element that is subject to rearrangements. Plasmids carrying only part of the input DNA together with fragments of silkworm DNA were rescued from the transgenic animals. One of the rescued plasmids contained a sequence which belongs to a family of evolutionarily conserved repeated sequences.

Animals↗
PubMed1977

[Effect of coamide on immunogenesis during antibiotic therapy].

The dynamics of the antibody-producing cells in the spleen and the titer of hemagglutinines in the blood of albino mice immunized with sheep erythrocytes and treated with various doses (250, 500, 1000 gamma) of oxytetracycline and monomycin and their combinations with coamide, a complex of cobalt with nicotinic acid amide at different periods after the immunization. It was found that oxytetracycline in doses of 500 and 1000 gamma and monomycin in doses of 250, 500 and 1000 gamma administered intramuscularly for 4 days had an inhibitory effect on both the antibody-producing cells and the titer of hemagglutinines in the immunized animals at various periods after the immunization. Consequently, oxytetracycline and monomycin had the immunosuppressive effect. Exposure of the animals treated with oxytetracycline and monomycin to coamide for 5 days provided an increase in the number of the antibody-producing cells and the titer of the hemagglutinines. The results of the study showed the perspectivity of coamide use in complex therapy of infectious diseases.

Animals↗
PubMed1976

[Congenital disorders of the thyroid gland in experimental litters obtained from mothers subjected to immunization and the action of I-131].

I131 injected to rabbits immunized with homologous thyroid gland on the 19th-20th day of pregnancy led to congenital disturbances of the thyroid gland in the experimental litters in the I and II generations. The functional activity and the activity of proteolytic enzymes of the thyroid gland decreased by the 30th day of the postnatal development. There was revealed a distinct correlation between the content in the thyroid gland of the experimental litters of DIT + MIT and of organic forms--T3 + T4. During the first days after birth DIT + MIT content showed a sharp fall and increased by the 30th day; on the contrary, iodine binding into organic forms decreased with the progress of age. Histological examination of the thyroid glands in the experimental litters demonstrated lymphoid-plasmocytic infiltration, along with connective tissue proliferation, which led to a marked sclerosis and fibrosis of tissues, hypofunction. Beginning from the age of one month there was seen an extensive nodular proliferation, which possibly served as the beginning of parenchymatous goiter formation. The appearance of lymphoid-plasmocytic infiltration in the thyroid gland of the II generation is considered to be the result of congenital predisposition to the autoimmune thyroiditis inlaid in the memory cells and intensified during birth.

Amino Acids↗