PubMed Health⌕ Search

Biomedical subjects

I S Freĭdlin

Publications and source records attributed to I S Freĭdlin.

At least 19 recordsLinked to original sources
PubMed2005

[Proliferative activity of human endothelial cell line EA.hy926 and its modulation].

Angiogenesis is a complicated process, which is regulated by numerous cytokines and growth factors. Besides, the interaction of endothelial cells with extracellular matrix components, with other cell types and with each other is essential for the formation on new blood vessels. The initiation, continuation and completion of angiogenesis depend on the balance of pro- and antiangiogenic factors in the endothelium microenvironment. Factors that influence endothelial cell proliferation are necessary for vascular development and their normal functioning. The influence of new pharmaceutical agents on angiogenesis is commonly evaluated by results of in vivo assays, i.e. chick chorioallantoic membrane and rabbit cornea assays. However, reported results are not always objective. So, the aim of our study was to elaborate methods of estimation of endothelial cell proliferation as one of important stages of angiogenesis.

Animals↗
PubMed2000

[Characteristics of the acute phase reaction in humans with various types of autonomic nervous system regulation during simulated hyperthermia].

Depending on the type of autonomous regulation, differences in basic levels of interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF alpha) were revealed under conditions of hyperthermia in healthy subjects aged 19-21. A parasympathetic type of autonomous regulation corresponded to higher initial levels of proinflammatory cytokinesis, whereas a dominating sympathetic type corresponded to lower levels of the IL-1 beta and TNF alpha. The subjects with the latter type of regulation revealed an increase in the IL-1 beta TNF alpha combined with a higher heat tolerance. The subjects with the former type of regulation revealed a lower heat tolerance. The increase in the alpha2-macroglobulin appeared to be a most typical acute phase response of the human body to hyperthermia.

Acute-Phase Proteins↗
PubMed1999

[The regulatory functions of pro-inflammatory cytokines and acute-phase proteins].

The paper provides a brief review of recent basic studies made by the Department of Immunology, Institute of Experimental Medicine, Saint Petersburg. They show that with a panel of macrophage-like cell lines of varying maturation (P388D, THP-1, U937, HL-60), the ability to produce TNF alpha spontaneously and to synthesize TNF alpha in response to atherogenic low-density lipoprotein stimulation correlates with the degree of cell differentiation that can be in turn induced by agents such as phorbol myristic acetate. The TNF alpha molecular site responsible for the macrophage-activating action of TNF alpha was identified as peptide 123-131. The latter was demonstrated to be uninvolved in the cytotoxic activity of TNF alpha. In addition to its activating and modulating effects against neutrophils, monocytes, and lymphocytes, the acute-phase reactant C-reactive protein was found to be able to bind the antiinflammatory cytokines IL-4 and TGF beta.

Acute-Phase Proteins↗
PubMed1997

[The potentials of immunological laboratory diagnosis].

Clinicians of different profiles often direct their patients to immunological tests because of a high incidence of various immunopathological syndromes, such as immunodeficiencies and allergic and autoimmune diseases. The efficacy of an immunological study depends on the task of the laboratory verification of the tentative clinical diagnosis, on the disease stage, and planned treatment. Biological material for investigation is collected depending on the task of the study and localization of the pathological process. It is not only the traditional material-blood, but other biological fluids of the organism as well. The choice of an adequate and informative complex of methods is also determined by the tasks of investigation. Special attention is paid now to methods for assessing the cytokine status of the organism. Interpretation of the results is the most intricate step of immunological tests because the notion of "immunological norm" is ambiguous and it is necessary to take account of the individual shifts of immunological parameters in the course of disease.

Humans↗
PubMed1996

[The effect of the secretory products of mononuclear phagocytes from patients in a control group and from patients suffering from acute nonlymphoblastic leukemias on the cells of the U-937 monoblastic line].

Effects of AML and normal mononuclear phagocyte conditioned media (CM) on the proliferation and differentiation of monoblastic human cell line U-937 have been studied. The normal mononuclear phagocyte CM inhibited proliferation and weakly stimulated differentiation of U-937 cells, whereas AML CM exerted no effect. Activation of both normal and AML macrophages with phorbol ether (TPA) was followed by enhancement of CM effect. TPA treatment corrected defects of secretory activity of AML mononuclear phagocytes. A possible role of different monokines in the regulation of proliferation and differentiation of leukaemic cells is discussed.

Bone Marrow Cells↗
PubMed1994

[The comparative characteristics of the immunogenic and immunomodulating activity of different antigenic preparations of the causative agent of Q fever Coxiella burnetii].

The immunogenicity of the Coxiella burnetii corpuscle antigen and two its components, obtained after the treatment with chloroform-methanol or extraction by trichloroacetic acid, was investigated. All the studied antigens were highly immunogenic. A strong correlation was discovered between the immunogenic and immunomodulating properties of the C. burnetii antigens. Cells of the mononuclear phagocytic system are the targets for stimulating action of the studied antigens. A cyclic increase of antibacterial activity and oxygen-dependent metabolism of the peritoneal cells was noted, in addition to the increase of the natural splenocyte cytotoxicity caused by the action of these antigens. The role of cytokines in rising the activity of peritoneal cells and splenocytes, caused by immunization of mice with the above antigenic substances, is discussed.

Adjuvants, Immunologic↗
PubMed1991

[Use of tuftsin in experimental leprosy].

The effect of tuftsin was studied in vivo using CBA mice infected with M. leprae by Shepard's technique and in vitro using macrophage-like cell line P. 388 (Co-cultivated with M. leprae) and the cultivated leproma tissue. It was found out that tuftsin acted as a stimulator of M. leprae multiplication in foot-pads of mice and as a prolongator of M. leprae survival in the cells of macrophage-like cell line P .388. It is concluded that using tuftsin might be useful in view of studying different aspects of experimental leprosy.

Animals↗
PubMed1990

[Changes in the surface and activation of circulating leukocytes after autologous transfusion of UV-irradiated blood].

Under study was the dynamics of functional properties of leukocytes of healthy people and patients after UV-irradiation of their blood, mixing the UV-irradiated and non-irradiated blood. It was shown that UV-irradiation and mixing the irradiated and non-irradiated blood facilitated the liberation of bactericidal cation proteins of leukocytes, higher expression of membrane receptors, growth factors, activation of reparation of DNA after its injury by gamma-rays. It proves the role of immediate activation of leukocytes of the circulating blood in trigger mechanisms of effects of autotransfusion of UV-irradiated blood.

Blood↗
PubMed1990

[The modelling of chronic infection (experimental leprosy) against a background of macrophagal immunodeficiency].

The dynamics of mycobacterial multiplication was followed in mice with intraplantar leprosy infection and preinduced macrophage insufficiency. The characteristics of Shepard's model appeared to be similar to those of the method proposed by the authors including the susceptibility to the main antileprosy drugs. Peritoneal macrophages were cytochemically studied in the process of development of mononuclear phagocyte deficiency and experimental leprosy. It was concluded that the method proposed preserving all the merits of Shepard's model should allow one to shorten significantly the duration of testing potential drugs for their antileprosy activity.

Animals↗
PubMed1990

[Possibilities of more accurate evaluation of the degree of myocardial damage and the completeness of reparative processes in patients with acute myocardial infarction by studying the characteristics of monocytes].

Patients with acute myocardial infarction (MI) were found to have hyper- and dyslipidemias independent of the depth of myocardial lesions and, in addition, to have more severe granulo- and monocytosis, higher adhesive and phagocytic ability of blood mononuclears that are typical for penetrating MI. Examining biochemical and immunological indices in the time-course of acute MI enables one to assess the completeness of reparative process in the myocardium. A significant and long-term monocyte activation in patients with penetrating MI seems to be due to an extended necrotic area and further formation of a focus aseptic inflammation, from whose the product that stimulate the production and function of blood monocytes are absorbed.

Adult↗
PubMed1989

[The interaction of macrophages and hematopoietic stem cells of mice in vitro and in vivo].

In the previous in vivo experiments it was shown that macrophages could modify the direction of haematopoietic stem cell (CFU-S) differentiation from erythroid to myeloid one, when injected simultaneously to lethally irradiated mice. Stable absorption of 50% CFU-S on the macrophage monolayer was documented in in vitro experiments, when it was incubated for 1 hour together with bone marrow cells. After administration to syngeneic recipients the CFU-S adsorbed by macrophages formed myeloid spleen colonies mainly. The nonadsorbed part of CFU-S underwent similar changes in the direction of differentiation, but only after a longer (2.5 hour) coincubation. The involvement of monokines in the control of the early differentiation of haematopoietic stem cells is suggested.

Adsorption↗
PubMed1989

[Possibilities of the use of various biochemical and immunologic indicators in the differential diagnosis of unstable stenocardia and acute myocardial infarction].

Changes of systemic immune status, involved in the immunopathogenesis of atherosclerosis, have been identified in patients with unstable angina pectoris. The developing acute myocardial infarction is accompanied by the formation of a myocardial aseptic inflammatory focus, from which biologically active products are absorbed, resulting in additional immunologic shifts. A differential diagnosis algorithm has been evolved on the basis of the comparison of a series of biochemical and immunologic parameters in patients with unstable angina, investigated at the peak of its clinical manifestations, and those with acute myocardial infarction.

Adult↗
PubMed1988

[Screening of immunomodulators by using the system of mononuclear phagocytes].

Immunomodulating effects of various agents can be mediated by the system of mononuclear phagocytes (SMP). Immunomodulators are able to interfere with the initial events in activation of mononuclear phagocytes (MP) on their membranes which inevitably has its impact on molecular manifestations of the MP activation: the oxidative outburst events. At the initial (tentative) stage of the screening potential immunomodulators it is expedient to use tests providing estimation of the oxidative outburst intensity by the activity of glucoso-6-phosphate dehydrogenase, the key enzyme of the hexose monophosphate shunt and by the level of superoxydanions production judged by reduction of nitroblue tetrasolium (NBTT). The use of transplantable macrophage-like lines J.744 and P 338D as the targets instead of murine peritoneal MP made it possible to increase reproducibility of the results in screening of immunomodulators. An experimental model of the mouse abdominal cavity clearance within the first hours after intraperitoneal administration of the test bacteria was used for estimating the effect of the potential immunomodulators on the barrier function of the SMP in the host. Experimentally modeled quantitative and functional defects in the SMP served as and adequate test system for study of immunostimulating agents.

Adjuvants, Immunologic↗
PubMed1988

[Content of lysosomes and lipids in the cytoplasm of the blood monocytes in patients with ischemic heart disease].

Coronary patients with unstable angina in the presence of considerably changed serum lipid spectrum showed marked changes in peripheral monocyte metabolism (accumulation of lipids and declining cytoplasmic lysosome levels). These changes were partly induced by pathologic components of blood sera, such as atherogenic lipoproteins and circulating immune complexes, as evidenced by the demonstrated capacity of coronary patients' serum to cause lipid accumulation and a drop of monocyte lysosome level in normal controls. Changes in blood monocyte metabolism of coronary patients may reflect the severity of atherosclerotic developments.

Antigen-Antibody Complex↗
PubMed1988

[Macrophage activation induced by a synthetic antioxidant].

The effect of a synthetic antioxidant 2-tretbutyl-3-hydroxypyridine (TBHP) on the function of murine peritoneal macrophages (MP) has been studied. A direct contact of TBHP with MP in vitro increased the activity of a key enzyme of glucose monophosphate graft--glucose-6-phosphate dehydrogenase and the proportion of flattened MP. as compared to the control. Upon intraperitoneal MP injection the number of MP's in the abdominal cavity of mice increased. They differed from control MP's in enhanced flattening and phagocytosis. In mice with preinduced defect of abdominal clearance TBHP contributed to the recovery of the normal level of antibacterial protection. In all the in vitro and in vivo tests studying its activating effect on MP, the synthetic antioxidant was not inferior to the standard MP activator--bacterial lipopolysaccharide.

Animals↗