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Biomedical subjects

N N Voĭtenok

Publications and source records attributed to N N Voĭtenok.

At least 19 recordsLinked to original sources
PubMed1995

[Effect of internal sequences in the Moloney murine leukemia virus genome on replication].

Construction and using of retrovirus vectors derived from the Moloney murine leukemia virus (MoMuLV) are described. These vectors, designated minimal vectors, contain the left and right long terminal repeats (LTRs), a binding site for proline tRNA, a polypurine tract (PPT), and a dominant marker for selective introduction of vectors into a packaging cell line, but lack the internal sequences of the virus genome. The experiments showed that the minimal vectors can be replicated and that their titer was approximately 1500-fold lower than that of wild-type vectors. The minimal vectors were shown to contain all the cis-acting sequences necessary for correct reverse transcription. One infectious virion. like wild-type viruses, produced only one provirus. Unlike the avian reticuloendotheliosis virus (REV), psi+ and psi(-)-genomes of MoMuLV did not compete for virion proteins in the psi2 packaging cell line. When an insert was introduced into a central part of the lTR U5 region, the titer of the minimal vector remained the same, while the titer of the wild-type vector decreased approximately 40-fold.

3T3 Cells↗
PubMed1992

[Effects of human defensin HNP-1 on the production of tumor necrosis factor-alpha by human blood monocytes in vitro].

The influence of human defensin HNP-1 on the synthesis of tumor necrosis factor-alpha (TNF-alpha) by human blood monocytes was studied. It was shown that TNF-alpha production by human monocytes activated by SAC or PMA was augmented in the presence of HNP-1 concentrations of 10(-8)-10(-9) M. HNP-1 alone induced no synthesis of TNF-alpha. High concentration of HNP-1 (10(-4) M) was cytotoxic for human monocytes.

Blood Bactericidal Activity↗
PubMed1992

[Differences in anti-oncogene p53 expression in human monocytes and lymphocytes in vitro].

The p53 gene has been associated with malignant transformation as well as "anti-oncogene" activity. In the present report expression of p53 in resting and activated human blood monocytes and lymphocytes is analyzed. It is found that human monocytes freshly isolated by continuous percoll gradient centrifugation contained detectable level of p53 mRNA. Stimulation of monocytes by potent activation inducer Staphylococcus Aureus Cowan I for 3-5 hr caused disappearance of r53 mRNA. In contrast, induction of high level of TNF-alpha mRNA was detected. Addition of cycloheximide had no effect on p53 mRNA content in stimulated monocytes, and caused disappearance of mRNA in resting cells. In lymphocytes cultures p53 mRNA was absent in freshly isolated cells and in resting lymphocytes cultured for 20 hr. Activation of lymphocytes by lectin caused accumulation of p53 mRNA. We suggest that r53 gene regulation and functions might be different in human monocytes and lymphocytes.

Blotting, Northern↗
PubMed1991

[Localization of an antigenic determinant of recombinant interleukin-2, recognized by monoclonal antibody 13B1].

We suggest a simple approach to localization of antigenic determinants for the monoclonal antibody 13B1 raised against recombinant human interleukin-2. The approach is based on the limited trypsin proteolysis, peptide separation by the O'Farrell method and identification of the peptides, interacting with monoclonal antibodies, and comparison of the charge and length of these peptides with the corresponding values of theoretically possible peptides.

Amino Acid Sequence↗
PubMed1991

[Synthesis of tumor necrosis factor-alpha (TNF-alpha) by human monocytes in vitro].

The presence of TNF-alpha mRNA and protein in circulating human blood monocytes isolated by continuous Percoll gradient fractionation was studied. The technique of RNA isolation from the blood samples was used to study TNF-alpha mRNA expression. It was shown that human blood monocytes of healthy donors contained no presynthesized pool of TNF-alpha mRNA as well as no TNF-alpha protein.

Blotting, Northern↗
PubMed1989

[Monoclonal antibodies to an artificial immunogen, specifically demonstrating phosphotyrosine-containing proteins].

The importance of protein phosphorylation at tyrosyl hydroxy groups in the control of cell proliferation has recently been established. For identification of tyrosine-phosphorylated proteins, monoclonal antibodies (Mabs) against artificial immunogens containing O-phosphotyrosine (pTyr) or tripeptide pTyr-Gly-Gly as haptens were generated; the haptens were coupled to carrier proteins (bovine serum albumin, human immunoglobulin, keyhole limpet hemocyanin). After immunization of mice with pTyr coupled to keyhole limpet hemocyanin, Mabs were generated which were highly specific for pTyr and did not cross-react with O-phosphoserine, O-phosphothreonine, tyrosine or nucleoside-5'-monophosphates. The Mabs specifically react with tyrosinephosphorylated proteins in the Rous sarcoma virus-transformed rat XC-cell.

Animals↗
PubMed1989

[Autospecific antileukemia cytotoxic lymphocytes induced by interleukin-2 and their use for elimination of leukemic cells from human bone marrow in vitro].

The possibility of production of cytotoxic antileukemic lymphocytes (CTL) was studied in a mixed culture of lymphocytes and autologous leukemic cells of patients with varying types of acute leukemia. It has been shown that CTL can be induced only in the presence of exogenous preparations of lymphocytic interleukin-2. CTL can be reproduced in vitro in amounts sufficient for the conduction of immunotherapy. Four-hour incubation in vitro of the bone marrow containing leukemic cells with antileukemic CTL permits the bone marrow to be completely free of leukemic cells, and to preserve hemopoietic precursor cells (CFE-GM).

Bone Marrow↗
PubMed1988

[Interleukin 2].

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Animals↗
PubMed1985

[Effect of cytotoxic lymphocytes obtained by in vitro immunization with syngeneic lymphoma cells on pluripotent hemopoietic cells].

The possibility of the presence of leukemia-associated antigens on pluripotent hemopoietic cells was studied with the aid of immune lymphocytes, cytotoxic against mouse syngeneic lymphoma cells. Cytotoxic lymphocytes were obtained during immunization in vitro of C57BL/6 mouse splenocytes by syngeneic T lymphoma EL-4 cells in the presence of interleukin-2. Specific cytotoxic activity of immune lymphocytes as regards EL-4 cells was not blocked by addition of normal bone marrow cells. Incubation of the bone marrow with immune killers did not lead to a decrease in the number of colony-forming units in the spleen. It was shown that using cytotoxic lymphocytes the total killing of lymphoma cells might be achieved in a mixture of bone marrow and lymphoma cells, whereas pluripotent precursor cells might be retained.

Animals↗
PubMed1985

[Elimination of syngeneic lymphoma cells from a mouse bone marrow suspension using immune cytotoxic lymphocytes sensitized in vitro].

Murine splenocytes were cultivated with syngenic EL-4 lymphoma cells in the presence of interleukin-2 to obtain cytotoxic antileukemic lymphocytes. It was shown that the use of cytotoxic lymphocytes helped killing completely syngenic lymphoma cells in the mixture of bone marrow and EL-4 cells, spleen colony-forming hemopoietic predecessor cells being retained.

Animals↗
PubMed1976

[Physicochemical properties of the human lymphocyte mitogenic factor induced by phytohemagglutinin].

Some physical and chemical properties of the mitogenic factor (MF) produced in vitro by PHA-stimulated human lymphocytes were investigated. Treatment of the culture medium with proteases proved to decrease the MF activity sharply. The MF was found to have an elution pattern in Sephadex and Bio-gel gels similar to proteins with the molecular weight of 20 000--30 000 daltons (peak--25 000). In experiments with the MF fractionation by disc-electrophoresis on 5% polyacylamide gel the MF formed a few discrete peaks in the fractions corresponding to the mobility of alpha1- and alpha2-globulins and transferrin. In isoelectric focusing the MF formed 3 fractions in the pH range of 4.5--8.3. Functional heterogeneity of the MF is suggested.

Cells, Cultured↗