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V I Agafonov

Publications and source records attributed to V I Agafonov.

At least 19 recordsLinked to original sources
PubMed2006

Effects of natural suppressor cells on production of Th1 and Th2 cytokines and proliferation of polarized T cells.

Natural suppressor cells from the bone marrow of intact animals and mice with Th1- and Th2-dependent immune response largely suppressed the production of Th1 (IFN-gamma, IL-2) and Th2 cytokines (IL-4). Antiproliferative activity of natural suppressor cells from intact and immunized animals was mediated by NO. Proliferation of Th1 cells was suppressed greater than that of Th2 cells. This selective effect of natural suppressor cells on the proliferation of target lymphocytes was due to higher stimulatory potential of Th1 cells (in comparison with Th2) towards natural suppressor cells.

Animals↗
PubMed2005

Mechanism of antitumor activity of bone marrow natural suppressor cells.

Co-culturing of P-815 tumor cell strain and intact mouse bone marrow cells nonadherent to plastic resulted in the appearance of soluble mediators with antitumor activity. Bone marrow cells start releasing these antiproliferative factors only after signal exchange with the target tumor cells. The cell-cell contact is an important factor for the induction of antitumor activity. Antitumor activity of bone marrow cells (similarly as immunosuppressive activity) is realized through suppressor factors; the appearance of these factors is induced by target tumor cells.

Animals↗
PubMed2004

[Ehrlich tumor cells stimulate T-cell production of interferon-gamma and are resistant to autocrine nitric oxide].

Ehrlich tumor cells released factors which activated T-cell production of interferon-gamma and triggered a mechanism of nitric oxide (NO) production instead of interferon-gamma. When cultured in vitro, they produced NO without stimulation and responded to interferon-gamma by an output rate of NO significantly greater than that in bone marrow cells. Unlike P-815 cells, those of Ehrlich tumor proved resistant to autocrine NO.

Animals↗
PubMed2003

Effect of antibodies to histamine in ultralow doses on production of allergen-specific antibodies.

We studied the effects of potentiated antibodies to histamine on production of IgE and IgG1 in response to 3-fold immunization of mice with ovalbumin in doses of 0.5, 10, and 100 microg. The course of treatment with antibodies to histamine suppressed production of allergen-specific IgE and IgG1 in mice 2-fold immunized with ovalbumin in doses of 100 and 0.5 microg, respectively. In mice immunized 3 times with ovalbumin in various doses the preparation suppressed production of IgE and IgG1.

Allergens↗
PubMed2003

Effect of individual and combination treatment with cytokines on expression of sialoadhesin by bone marrow macrophages.

We studied the effects of lipopolysaccharide, interferon-gamma, interleukin-1, or tumor necrosis factor-alpha and combination treatment with tumor necrosis factor-alpha and interleukin-1 or interferon-gamma on the expression of sialoadhesin receptors on the membrane of bone marrow macrophages, macrophage adherent ability, and production of nitric oxide by these cells. Sialoadhesin expression was evaluated by binding of macrophages to sheep erythrocytes labeled with radioactive (51)Cr. Treatment of bone marrow cells with interferon-gamma improved adhesive properties of macrophages, but did not modulate expression of sialoadhesin. Interleukin-1 and tumor necrosis factor-alpha had no effect on the test parameters. Combination treatment with these cytokines enhanced binding of sheep erythrocytes to macrophages. Administration of lipopolysaccharide or combination treatment with interferon-gamma and tumor necrosis factor-alpha increased the count of macrophages adhering to plastic and stimulated expression of sialoadhesin. Combination treatment with interferon-gamma and tumor necrosis factor-alpha stimulated production of nitric oxide by bone marrow macrophages. Blockade of nitric oxide synthesis had no effect on adhesive properties of macrophages and expression of sialoadhesin.

Animals↗
PubMed2000

Opposite effects of dexamethasone on antitumor and natural suppressor activities of bone marrow cells.

Effects of dexamethasone on the ability of nonadherent bone marrow cells to inhibit proliferation of mastocytoma P815 cells and concanavalin A-stimulated proliferation of syngeneic splenocytes were studied. Antitumor activity of cells increased, but their natural suppressor activity decreased in the presence of dexamethasone. Pretreatment with dexamethasone (for 3 h) did not affect the sensitivity of mastocytoma cells to antitumor factors and the antitumor activity of bone marrow effectors. Pretreatment of bone marrow cells with dexamethasone for 24 h potentiated antitumor activity of their nonadherent fractions.

Animals↗
PubMed1993

[Mechanisms of the stimulating effect of d-glucuronic acid on the processes of bone marrow granulomonocytopoiesis in cytostatic myelodepression].

The mechanisms of regulating influence of D-glucuronic acid on granulomonocytopoiesis++ have been studied by using the model of cyclophosphamide-induced myelodepression. Increase of colony-stimulating and interleukin-1 activities production by hemopoiesis inducing microenvironment cells, the stimulation of hemopoietic islets and the different granulomonocytopoiesis precursor cells forming have been shown to be the base of activating action of D-glucuronic acid on bone marrow granulomonocytopoiesis recovery.

Animals↗
PubMed1993

[The production by bone marrow cells of humoral factors in extreme exposures of different origins].

The intensification of cytokine-producing activity by mouse bone marrow cells forming the hemopoiesis-inducing microenvironment (HIM) was demonstrated to be an obligatory component of adaptation processes developing in the body under the influence of different extreme factors (immobilization, inflammation, cytostatics, irradiation). As a rule, the first stress reaction of adhesive and nonadhesive cells consists in interleukin-1 and interleukin-3 secretion with following erythropoietic and colony-stimulating activity induction. For all this, the levels and periods of production of hemopoiesis humoral regulators are comparable under hemopoiesis-stimulating or -suppressing influences. Finally Activation of HIM functional properties expresses the interaction of central and local regulating systems, which favours the formation of an optimal response of the blood system to stress.

Animals↗
PubMed1993

[The adrenergic mechanisms controlling the proliferation and differentiation of hematopoietic precursor cells under immobilization stress].

The role of adrenergic structures in mechanisms of erythro- and granulomonocytopoiesis precursor cell proliferation and differentiation under immobilization stress was antagonist administration inhibited stress-induced rise of erythroid, erythrogranulocyte and granulocyte hemopoietic islets erythrogranulocyte and granulocyte hemopoietic islets forming in the bone marrow. In vitro the alpha-adrenergic agonist had a direct activating effect on CFU-GM but on CFU-E growth in normal state (10(-5) M) and after immobilization (10(-9), 10(-7) M). At the same time beta-adrenergic agonist (10(-5) M) increased exclusively CFU-E growth after extreme influence. Thus, adrenergic mechanisms are of great importance in direct (receptor) and microenvironmental hemopoiesis-induced stimulation of the processes of proliferation and differentiation of hemopoietic precursors during stress.

Animals↗
PubMed1991

[The efficacy of exogenous and endogenous interferonization in preventing influenza].

In this work the results of using interferon (IFN), Dibasol and the combination of these preparations for the urgent prophylaxis of influenza and acute respiratory diseases (ARD) among the employees of the Gamaleia Research Institute of Epidemiology and Microbiology (USSR Acad. Med. Sci.) are summarized. Reaferon and Dibasol decrease ARD morbidity 2 times and leukocytic IFN decreases it 1.4 times, while the combined administration of Dibasol and IFN has proved to be ineffective. Reaferon is mainly a prophylactic remedy; it has been found to bring about almost no decrease in the number of patients at the peak of morbidity, while pronouncedly decreasing it in two weeks after the administration of the preparation. Dibasol has a curative effect, sharply interrupting the beginning rise of morbidity. Reaferon normalizes the characteristics of the IFN status, decreasing the amount of circulating IFN and enhancing the capacity of leukocytes for producing alpha-IFN and gamma-IFN. For the prophylaxis of respiratory infections the use of Reaferon is advisable 3-4 weeks prior to the beginning of the epidemic and then, when the first cases of infection are registered, the course of prophylaxis with Dibasol should be carried out.

Absenteeism↗
PubMed1987

[Modulating effect of enkephalins on hemopoieis under stress].

The influence of enkephalins on the medullary hemopoiesis has been studied during stress reaction in noninbred mice. It was shown that leu-enkephalin administration suppressed, while met-enkephalin injection stimulated granulocyto- and erythropoiesis during immobilization stress.

Animals↗
PubMed1984

[Mechanisms of T-lymphocyte stimulation of erythropoiesis under local body irradiation].

Thymocytes transplanted into thymectomized mice with a locally irradiated lower limb in a dose of 7 Gy were accumulated in the depleted bone marrow to stimulate the processes of postradiation erythron regeneration. Cytosar treatment did not affect the regulatory function of thymocytes. At the same time thymocytes treated with actinomycin D possessed less powerful stimulating effect than intact ones.

Animals↗