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Biomedical subjects

I G Sidorovich

Publications and source records attributed to I G Sidorovich.

At least 19 recordsLinked to original sources
PubMed2005

[Comparison CCR5de132 mutation in the CCR5 gene frequencies in Russians, Tuvinians, and in different groups of HIV-infected individuals].

The 32-bp deletion (CCR5del32 mutation) in the CCR5 (chemokine (C-C motif) receptor 5) gene, encoding CCR5 chemokine receptor, is one of the factors determining natural resistance to human immunodeficiency virus (HIV-1) infection. In the present study, the samples of Russians (n = 107), Tuvinians (n = 50), and HIV-infected individuals were examined for the presence of CCR5del32 mutation in the CCR5 gene. The CCR5del32 allele frequency in Russians and Tuvinians constituted 7.84 and 2%, respectively. Among HIV-1 infected individuals, two groups, of macrophage-tropic HIV-1 strain- and T-cell-tropic HIV-1 strain-infected were distinguished. The CCR5del32 allele frequency in the first group (6.45%) was lower than in the second one (8.73%). Statistical treatment of the HIV-1 infected individuals typing data showed that the difference in the CCR5del32 allele frequencies between the groups of sexually (macrophage-tropic) and parenterally (T-cell-tropic) infected individuals observed was within the limit of random deviation.

Alleles↗
PubMed2000

[Pyridoxyl amino acid esters in peptide synthesis].

Pyridoxyl residue was suggested to be used as a multifunctional protective and modifying group in peptide synthesis. The modification was carried out by introducing the pyridoxyl residue in free or partially protected peptides or by the addition of amino acid pyridoxyl esters by the methods of conventional peptide synthesis without the removal of the pyridoxyl group at the terminal stages of the synthesis (the second approach is more convenient). Pyridoxyl residue was also used as a spacer in solid phase peptide synthesis. It was attached to the polymer by the alkylation of the hydroxyl groups or of the pyridine ring of the pyridoxyl derivatives with the chloromethylated styrene-divinylbenzene copolymer (the standard Merrifield resin). Potentials for the use of pyridoxyl derivatives in the synthesis of linear, multiplet, and cyclic peptides are discussed.

Alkylation↗
PubMed1992

Antibodies to MHC class II peptides are present in HIV-1-positive sera.

Seventy-five per cent of sera from HIV-1-infected individuals bind to the human B-lymphoma cells bearing the major histocompatibility class II molecule in enzyme-linked immunosorbent assay (ELISA). The binding is caused by the antibodies against the class II molecule present in the serum samples which prevent the interaction of murine anti-HLA.DR monoclonal antibody with B lymphoma in FACS analysis. The three highly conserved amino acid sequences in alpha- and beta-chains of the class II molecule and three homologous fragments in HIV-1 gp120 and gp41 were identified by computer search and synthesized. Using these peptides it was demonstrated that 28-48% of HIV-positive sera contain antibodies that cross-react with the peptide of HIV-1 origin and with the peptide from the class II molecule as well.

Amino Acid Sequence↗
PubMed1992

[The protective activity of preparations made from the tick-borne encephalitis virus grown using different cell cultures].

The preparations of tick-borne encephalitis (TBE) virus grown in swine embryo kidney cell culture have been shown to possess pronounced protective activity per unit of virion protein E in comparison with TBE virus preparations derived from cell culture 4647 and chick embryo cell culture. The antigenic activity of all virus preparations under study has proved to be practically the same. The role of post-translation modifications of TBE virus protein E in the manifestation of some of its biological properties is discussed.

Animals↗
PubMed1990

The use of synthetic peptides in the diagnosis of HIV infections.

The antigenic structure of HIV proteins was analyzed semiempirically. Peptides mimicking fragments of the main structural HIV-1 proteins (p17, p24, gp41, and gp120) were selected and synthesized, with account taken of the level of conservation of various HIV genome fragments. The synthesized peptides were then subjected to immunological study with human sera in an enzyme-linked immunosorbent assay (ELISA). Peptides from two regions were found to be particularly immunoreactive with sera from HIV-1 infected persons: the C-terminal end of gp120 and a sequence approximately sixty to eighty amino acids in from the N-terminus of gp41. In fact, more than 96% of HIV-1 positive sera reacted with peptide 495-516 of gp120 (SP-III), peptide 584-602 of gp41 (LS-19), and peptide 601-616 of gp41 (SP-15). Additionally, twelve out of twelve serum samples from Ugandans infected with HIV-1 reacted with both SP-III (from HTLV-III) and SP-29 (gp41, 598-609; from the LAV-ELI isolate), suggesting that these immunodominant sites are useful diagnostically irrespective of the infecting isolates. HIV-2 peptides were also synthesized, and immunoreactivity and cross-reactivity examined. Only two peptides (581-603 of gp32 and 592-605 of gp32) reacted with all of the six HIV-2 positive sera tested. These peptides did not react with HIV-1 positive sera or control sera from healthy blood donors.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1980

[Nature of the target cells in bone marrow B-suppressor action studied on a simplified model of suppression activity registration].

The addition of bone marrow cells to spleen cells and lymph node cells stimulates by mitogents, but not to fibroblast-like cells, leads to a significant reduction of DNA synthesis in mixed cultures in vitro. The suppression effects appears only in two days and the suppressor cell activity is the stronger, the intensive is the target cell proliferation. It is shown that intact bone marrow cells can suppress the lipopolysaccharide-activated bone marrow cell proliferation in vitro. A conclusion may be draw that cells of the lymphoid system serve as target cells for the bone marrow suppressor cells, and the role of these lymphoid system cells is to control immunogenesis processes by suppressing the target cell proliferation activity in the bone marrow.

Animals↗
PubMed1980

[Suppressive effect of bone marrow cells from normal and leukemic mice on antibody production in culture of spleen cells in vitro].

The suppressive effect of bone marrow cells from AKR and (CBA X C57BL)F1 mice aged 2--10 months on the immune response of syngeneic spleen cells to sheep red blood cells in vitro was investigated. It was shown that the suppressive action of leukemic mice bone marrow cells greatly increases by the age of 9--10 months as compared to 2-month age. In (CBA X C57BL)F1 mice the suppressive acitivty of bone marrow remains unchanged over the same time period.

Aging↗
PubMed1980

[Suppressive effect of xenogenic bone marrow cells on antibody formation in a spleen cell culture in vitro].

Bone marrow cells from syngenetic and xenogeneic donors of different species were added to splenocyte culture to induce the primary immune response to sheep red blood cells. It has been shown that both xenogeneic and syngeneic bone marrow cells suppress the primary immune response in vitro. A conclusion is made that the suppressant effect exerted by bone marrow cells on the immune response of splenocytes is not liable to xenogenic restriction.

Animals↗
PubMed1978

Bone marrow suppressor B cells in vitro.

Marrow cells from intact CBA and (CBA x C57B1)F1 mice added to a culture of syngeneic splenocytes at its initiation suppressed the generation of anti-SRBC antibody-forming cells. Removal of cells bearing surface immunoglobulins and/or MBLA led to a substantial reduction in the marrow suppressive activity. Marrow cells from mice pretreated with five doses of hydroxyurea did not suppress the immune response of syngeneic splenocytes to SRBC. While the total number of cells in the marrow of such animals declined 5-fold, the relative content of Ig-positive cells was somewhat increased. The proportion of blast cells dropped from 10.3 to 2.4%. No blast cells bearing surface immunoglobulins were observed. The proportion of cells incorporating [3H]-thymidine fell 40-fold. We conclude that suppression of the immune response to SRBC in vitro is mediated by immature precursors of the B lymphocyte series which are present in the bone marrow of intact mice.

Animals↗
PubMed1978

[Regulatory role of bone marrow in immunogenesis. III. Humoral factors stimulating and suppressing antibody formation produced by bone marrow cells in in vitro cultures].

As revealed by the method of cultivation of bone marrow and spleen cells, separated by nucleopore membrane, in two-chamber bottles, the bone marrow cells were capable of producing humoral factor stimulating antibody genesis by the spleen cells. A direct contact of the bone marrow cells with the actively proliferating antigen-stimulated cells of the spleen led to production of a spleen humoral factor suppressing the antibody genesis by the spleen cells. The suppressive action of the bone marrow cells on the antibody genesis in the culture of the spleen cells was mediated through the suppression of the spleen cells proliferation; proliferation of the bone marrow cells is enhanced.

Adjuvants, Immunologic↗