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Biomedical subjects

Iu M Vasil'ev

Publications and source records attributed to Iu M Vasil'ev.

At least 19 recordsLinked to original sources
PubMed2002

[Effect of actomyosin contractility on focal contacts of myofibroblasts and structure of stress fibers].

Myofibroblasts from rat lung were cultivated. These cells in addition to beta- and gamma-cytoplasmic actins, expressed alpha-smooth muscle actin (alpha-SMA) and formed a system of "supermature" focal contacts, which were connected with thick stress-fibers expressing alpha-SMA and myosin II. Reduction of actin-myison contractility by inhibitors BDM and ML-7 lead to stress fiber reorganization, e.g., decrease in their thickness, a selective disappearance of alpha-SMA expression and myosin translocation from bundles to the cytoplasm. Using immunofluorescence, interference-reflection microscopy and morphometry, we have demonstrated that an inhibition of actin-myosin contractility also leads to dispersion of myofibroblastic focal contacts. Phase-contrast and DIC video-enhanced microscopy of live cells showed morphological reorganization at the leading edge after inhibitory treatment. Thus, actin-myosin contractility controls the structure of "supermature" focal contacts of myofibroblasts and alpha-SMA expression in stress fibers.

Actins↗
PubMed2002

[Mode of epithelium-fibroblast interaction in mixed heterotypic cell cultures].

The interaction between epithelium (dog kidney epithelium MDCJ/clone 20) and fibroblasts (diploid human fibroblasts M19 and AG-1523) was studied in mixed heterotypic cell cultures. The mode of cell interaction depends on the manner of their collision. At collision of the epithelium lamella and the lateral side of fibroblast, the lamella was seen to creep under the lateral side to force back the fibroblast. At the frontal collision of epithelium and fibroblast lamellae, the mode of interaction depends on the local situation. With the presence of a free substratum around, the fibroblast formed a new lamella and moved aside from the place of collision. In the case, when the neighboring cells prevented fibroblast from moving, it migrated under the epithelium. In this work, we have first demonstrated the formation of specialized intercellular adhesions between epithelium and fibroblasts. The cultures were studied by phase contrast, interference reflection or video tape recording, using an image processing system (Hamamatsu). For studying adhesion, immuno-fluorescent methods were performed.

Animals↗
PubMed2001

[Change in fibroblast polarization during change in contractility of the actin cytoskeleton].

The aim of this work was to study role of the contractility in the process of fibroblast spreading. We investigated the morphology and cytoskeleton of cells seeded in the medium containing 2,3 butanedione monoxime (BDM), an inhibitor of myosin II and myosin-ATPase. Time-lapse video observation and immunofluorescence microscopy were used. BDM caused delay in spreading and blocked cell polarization, that led eventually to the conservation of disk-like cell morphology. The actin-myosin cytoskeleton was also BDM-changed. The number and thickness of stress-fibers decreased. Myosin II orientation was dramatically disturbed to obtain a difuse pattern in the cytoplasm. Paxillin-containing focal adhesions decreased in length and their distribution was changed. The movement of concanavalin A receptors and concanavalin A-coated beads on the lamellar cell surface was also BDM inhibited. It indicates an obvious depression of the lamellar cytoplasm activity and points to the damage of the actin-myosin cytoskeleton. Thus, the change in contractility of the latter alters significantly the morphogenesis of fibroblast spreading.

Actins↗
PubMed2001

[Neoplastic morphologic transformations and their normal analogs].

The mechanisms of possible cytoskeletal reorganizations leading to morphological transformations of cells of two types, epitheliocytes and fibroblasts, are discussed. It is suggested that the non-transformed cells of these types can exist in two morphological forms, sedentary and migratory, and that genetic changes occurring with carcinogenesis block the ability of cells to undergo transitions from the sedentary form to the migratory one.

Cell Movement↗
PubMed1996

[The effect of microtubules on the morphology of a fibroblast monolayer and its extracellular matrix].

The aim of this investigation was to study the effect of microtubule-specific drugs, taxol and colcemid, on the morphology of cytoskeletal systems and distribution of cell-associated extracellular matrix in dense cultures of fibroblasts. Immunomorphological examination of human 6-8 days old cultures revealed that microtubules, actin and vimentin filaments and filaments of extracellular matrix: fibronectin and tenascin-preferentially oriented in parallel with long axes of cell bodies. Depolymerization of microtubular system by colcemid and its disorganization by taxol lead to rapid and drastic changes in morphology of all cytoskeletal systems and in the organization of matrix network: fibronectin and tenascin filaments became disordered and, in particular, lost any orientation. These data show that microtubular system controls the morphological organization, and not only of two intracellular cytoskeletal systems, but also of extracellular matrix structures.

Actin Cytoskeleton↗
PubMed1995

[The hemodynamic, humoral and cellular effects of plasmapheresis in a refractory form of hypertension].

Plasmapheresis effects on hemodynamics, neurohumoral, immunological and cell parameters were examined in 48 patients with refractory hypertension. Hypotensive effect of plasmapheresis was found to combine with positive hemodynamics and microcirculatory shifts, pressor factor activity inhibition, slowing of immunocomplex condition progress, reduced red cell deformability in refractory hypertension.

Adult↗
PubMed1993

[The hemodynamic and neurohumoral correlates of the changes in the status of hypertension patients under the influence of acupuncture].

Course acupuncture with silver needles in auricular and corporal zones with additional effects of acupuncture zones in microneedle pressing produced a hypotensive action in 360 patients with initial essential hypertension. This effect registered in 82.1% of the patients exposed was not the only positive response as there was also a decline in hyperkinetic syndrome with a significant fall in energy consumption, reduction in circadian excretion of adrenaline, inhibition in the activity of plasma renin, normalization of lipid metabolism. The hypotensive effect in the majority of the patients persisted for 12 months. Hyperactivity of plasma renin, hypokinetic and extremely hyperkinetic hemodynamic types set limitations for the method efficacy.

Acupuncture Points↗
PubMed1993

[The molecular cellular aspects in predicting the course of an acute myocardial infarct].

Ultra-high-frequency dielectrometry was used to determine the dielectric permeability of erythrocyte suspension cell membranes in 48 patients with acute myocardial infarction who were given agonists, antagonists, and modulators of the adenylate cyclase system. The study showed that the functional status of erythrocyte membranes changed correlating with the clinical course of the disease. Changes in this status were followed by complications of improvement. It was evidenced that the trend of a pathological process in coronary stress was associated with the functional status of erythrocyte membranes. Ultra-high-frequency dielectrometry is a sensitive method for evaluating the status of patients with myocardial infarction, controls the natural history of the diseases at the molecular level and to predict the development of complications.

Adenylyl Cyclases↗
PubMed1992

[The role of intermediate filaments in forming cellular processes induced in fibroblasts by the tumor promoter TPA].

A tumor promoter phorbol 12-myristate 13-acetate (PMA) induces characteristic reversible changes in the cell shape in certain fibroblastic lines. This reaction to PMA may be regarded as a prototype of reorganizations involving formation of stable cytoplasmic processes. Two specific drugs, Taxol and Colcemid, were used to study the role of microtubules and vimentin-containing intermediate filaments (IF) in the development of PMA-induced reorganizations. A short (I h) exposure to PMA induced formation of processes in the control cells rather than in the Colcemid treated cells having depolymerized microtubules and the IF that collapsed around the nucleus. A longer (3-4 h) exposure to PMA of the colcemid-treated cells induced a partial reversal of the IF collapse; those parts of peripheral lamellae that contained IF were transformed into narrow noncontractile processes. It is suggested that the local interaction of the IF with the actin system is an essential step in the formation of processes from lamellae.

Actins↗