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Biomedical subjects

V P Shakhov

Publications and source records attributed to V P Shakhov.

At least 19 recordsLinked to original sources
PubMed2005

Inotropic response of the myocardium in rats with postinfarction cardiosclerosis exposed to extrasystolic treatment.

The inotropic response of the myocardium to extrasystolic treatment was studied on isolated perfused papillary muscles from rats with postinfarction cardiosclerosis. The development of postinfarction cardiosclerosis was accompanied by a decrease in myocardial excitability. The amplitude of extrasystolic contractions in the remodeled myocardium far surpassed the control. However, the amplitude of postextrasystolic contraction did not surpass that in normal contraction-relaxation cycle. Our results suggest that the ability of the sarcoplasmic reticulum in cardiomyocytes to accumulate Ca2+ is impaired during postinfarction remodeling.

Animals↗
PubMed2005

[Potential of bone marrow mesenchymal stem cells for the treatment of diseases associated with damage of cardiac tissue].

Ability of mononuclear and adhesive cells to form differentiated elements of various tissues and organs in tissue culture in vitro has been studied in experiments on CBA mice. It has been established that adhesion mesenchymal stem cells are present in bone marrow. These cells are able to generate muscular, nervous, endothelioid, epithelioid, reticular, fibroblastoid, chondrogenic, osteogenic, and other types of cells. Mesenchymal islets have been frequently found both as parts of colonies and as independent units. Potential developmental flexibility of mesenchymal cells allows to suppose their high efficacy in pathogenetic cell therapy of heart diseases when besides damaged muscular elements vascular and nervous elements should be also restored. Mononuclear cells have not demonstrated this ability. They formed mainly monocyte-macrophagal and lymphoid cells.

Animals↗
PubMed2004

In vitro formation of mesenchymal bone marrow islets.

We studied the formation of mesenchymal islets in the culture of bone marrow cells in vitro. Islet-like structures detected on day 6 of culturing contained a central epithelioid cell (differing from macrophages and fibroblasts) surrounded with round mesenchymal cells. The number of mesenchymal islets increased on days 12-14 of culturing, but decreased to zero by the 24th day. They appeared not only as individual structures, but also entered the composition of colonies and formed assemblies with surrounding cells of different maturity. Our results show that mesenchymal islets serve as structural and functional units of mesenchymopoiesis.

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↗
PubMed1992

[Influence of mast cells on the regulatory mechanisms of hemopoietic bone marrow in inflammation].

Acute infectious peritonitis simulated in mice was used to show that previous osmotic deterioration of the abdominal mast cell population significantly influenced the function of hemopoiesis-inducing microenvironment (HIM). The earlier production of the colony-stimulating and erythropoietic activities by the non-adhesive myelokaryocytes and the decreased production of these activities by the adhesive cells have been established. The results obtained evidence that mast cells modulate HIM mediating their influence on hemopoiesis under natural conditions of inflammation.

Animals↗
PubMed1992

[Compensation-adaptation reactions of hemopoiesis-inducing microenvironment of bone marrow in stress].

The time course of compensation-adaptation reactions of bone marrow hemopoiesis-inducing microenvironment (HIM) was studied in F1 (CBA x C57BL/6) mice subjected to 10-hour immobilization. The number of macrophage and fibroblastoid colony-forming units, committed and stem precursor stroma cells responsible for HIM transport was shown to increase in the hemopoietic tissue during adaptation syndrome. HIM activation in stress was found to be macrophage- and lymphocyte-dependent process.

Adaptation, Physiological↗
PubMed1991

Role of glucocorticoids in the regulation of bone marrow hemopoiesis in stress reaction.

We have studied the role played by glucocorticoids in the regulation of bone marrow hemopoiesis in stress reaction. The effector influence of the adrenal cortex hormones on the committed precursor cells of erythro-granulo-monocytopoiesis mediated through the T-cell system has been confirmed. Glucocorticosteroids initiate homing of the T-cell regulators of myelopoiesis of the Lyt-1+ phenotype from the lymphoid organs into the bone marrow.

Animals↗
PubMed1991

[Role of humoral factors in the regulation of hemopoiesis in stress].

The change of 11-1, IL-3, CSA concentrations in adherent and nonadherent bone marrow cells condition medium at stress were investigated. The activation of bone marrow hemopoiesis was registered at mice after immobilization stress. The number of CFU-GM increased on 1, 4 and 5 day after stress. Maximum of CSA in adherent and nonadherent cells conditioned medium was observed on day 4, 6 or 2, 5 respectively. The increasing of 11-3 activity in culture of nonadherent bone marrow cells was registered from day 1 and mount to maximum at 4-5 days. The increasing of 11-1 level in culture of adherent bone marrow cells was found at 1 and 4 days.

Animals↗
PubMed1991

The role of humoral factors of regenerating liver in the development of experimental tumors and the effect of Rhodiola rosea extract on this process.

In experiment on rats with Pliss lymphosarcoma (PLS) it was shown that partial hepatectomy (PHE), a course application of Rhodiola rosea extract (RRE) or combined effects inhibit the growth of tumors by 37, 39 and 59%, respectively, and that of metastases by 42, 50 and 75%. In combined treatment the process of hepatic regeneration was completed in earlier terms versus the animals which underwent PHE, and proliferative activity of the tumor and metastases decreased by 15 and 59%, respectively, judging by the degree of 3H-thymidine incorporation into DNA of these tissues. The assessment of clonogenic activity of PLS cells taken in the animals of this group, using the method of diffusion chambers, revealed a significant decrease in this index versus the rats which underwent PHE or which were given RRE (number of colonies per chamber being 4.8 +/- 0.5; 8.6 +/- 0.9; 5.7 +/- 0.6, respectively; in control 13.8 +/- 1.5). The assumption that these effects are determined by factors originating from the regenerating liver was confirmed in experiments with double-layer agar systems. Inhibition of colony-forming activity of PLS cells was the maximum in application of the hepatocytes of the rats which underwent a complex of effects, as a feeder, versus the hepatocytes taken in intact or hepatectomized animals, or the rats which were given RRE (number of colonies per plate well being 4.6 +/- 0.3; 15.7 +/- 1.6; 7.4 +/- 0.8; 8.7 +/- 0.9, respectively; in the control 25.6 +/- 6.5). In experiments on mice with Ehrlich adenocarcinoma, the factors isolated from the liver of animals subjected to PHE against a background of RRE administration and from the liver of mice which were given RRE only, as well as operated or intact ones, inhibited the tumor growth to 63, 38, 35 and 21%, respectively.

Adenocarcinoma↗
PubMed1991

[The role of separate subpopulations of bone marrow elements in regulating the proliferation processes of hemopoietic and tumor cells].

The role of intercellular interactions in regulation of proliferation process in normal and tumor cells has been studied in experiments with mouse hybrids F1 (CBA X C57BL/6). The cytostatic activity to tumor cells has been shown to possess both adherent and nonadherent cells of bone marrow. The adherent cell-effectors inhibit, nonadherent ones stimulate the DNA synthesis in myelokaryocytes of normal bone marrow. During the activation of bone-marrow proliferation (under 10-hour immobilized stress) the cytostatic effect of nonadherent cells to tumor ones grows; the myelokaryocyte proliferation is stimulated on the 4th day after immobilized stress. The cytostatic activity of adherent cell-effectors remains to be low up to 7th day after immobilization. The maximum of depression in cytostatic function of the adherent elements coincides with the peak of bone marrow proliferation activity (6th day). The character of changes in cytostatic activity of adherent cells to tumor and nontumor ones is of the same type. The data obtained testify to the generality of regulation mechanisms in proliferation of tumor and normal cells.

Animals↗
PubMed1990

[Methods of isolating hematopoiesis islets from the bone marrow].

The effectiveness of the enzymatic and mechanical methods for isolation of hemopoietic islets (HI) from rat bone marrow was comparatively studied. It has been shown that the use of collagenase brings higher yields of HI than the mechanical treatment of bone marrow, mainly at the expense of associations containing no central phagocytizing macrophages. When the mechanical method of HI isolation was used, erythroid islets associated with mononuclear phagocytes prevailed, while with the enzymatic method mainly erythro-granulocytic islets associated with macrophages or reticular cells were isolated. It has been suggested that granulocytic and erythro-granulocytic associations are less resistant to the mechanical treatment.

Animals↗
PubMed1990

[T-lymphocyte control over the proliferative activity of committed precursor cells of erythro- and granulomonocytopoesis in stress].

The role of T-lymphocytes in regulation of proliferation and differentiation processes of committed myelopoiesis cell precursors in F1 (CBA-C57Bl/6) mice, treated by 10-hour immobilization was studied. One of the first reactions of hemopoietic precursors at stress was estimated to be the increase of active proliferating cells-precursors, accompanied by the quantitative changes of their content. The creation of T-cell deficit by means of anti-thymic serum resulted in abolition of the above mentioned changes of erythroid and granulo-macrophage precursors marked in the processes of adaptation syndrome development.

Animals↗
PubMed1990

[The role of glucocorticoids in the development of the phenomenon of bone marrow hematopoiesis stimulation in stress].

In experiments in mice in the model of immobilizing stress the role of glucocorticoids in development of blood marrow stimulation phenomenon has been studied. The glucocorticoids have been found to play a leading role in adaptive reaction of blood system formation in response action of extreme factors, not exerting the myelosuppressing effect. This reaction is characterized by blood marrow hyperplasia development. The glucocorticoids influence the haemopoiesis through the T-lymphocyte system: the homing takes place on the 2-3 day after the beginning of effect of T-cells myelopoiesis regulator, expressing on the surface Lyt-1+, Lyt-2+ antigens.

Adrenalectomy↗
PubMed1990

Lymphocytic mechanisms of myelopoiesis regulation under stress.

The role of T-lymphocytes in the regulation of bone marrow haemopoiesis was investigated under conditions of immobilization stress in mice. Development of the general adaptation reaction was accompanied by hyperplasia of the bone tissue at the level both of the committed precursor cells and of the morphologically differentiated haemopoietic cells. The existence of a subpopulation of T-cells expressing the Lyt-1+,Lyt-2+,L3T4-antigens on their surface is demonstrated. T-lymphocytes with this phenotype migrated into the bone marrow of stressed mice and stimulated the proliferation and differentiation of erythroid and granulocyto-macrophagal precursors.

Animals↗
PubMed1990

[Changes in clonogenic properties of bone marrow and transplantable mice tumor cells during combined use of cyclophosphane and biological response modifiers of adaptogenic origin].

The clonogenic activity of tumors and blood marrow cells has been studied in experiments on CBA, BALB/C and C57B1/6 mice with the Ehrlich adenocarcinoma and Lewis lung carcinosarcoma treated with adaptogenic drugs of Rhodiola Rosea extract, a synthetic analog of Rhodiola phenol derivative, methyluracil and their combinations with cyclophosphamide. The extract and derivative are shown to protect the myelopoietic tissue from the toxic action of cyclophosphamide, retaining or increasing the suppressive effect of the latter towards clonogenic tumors cells. These data can be the reason for using the extract and derivative during the antitumor chemotherapy as biological response modifiers.

Animals↗