[Invasion of Escherichia coli A2 induces reorganization of actin microfilaments in Hep-2 cells].

Bacteria of spontaneously isolated non-pathogenic strain E. coli A2 have been previously shown to produce a new proteinase, referred to as protease ECP 32, which specifically cleaves actin (Khaitlina et al., 1988; Matveyev et al.

[Analysis of rat enterocyte ultrastructure during glucose absorption].

Electronmicroscopic study of rat enterocytes under glucose load (10-40 mM) has shown some changes of their structure: aggregations of intramembrane particles of the apical membrane in the microvilli region, the dilitation of lateral intercellular spaces below tight junction, the condensation of actin near tight and intermediate junctions. The presence of these changes and almost absolute absence of destructions in tight junctions organization indicate that the main pathway of the isotonic fluid containing glucose across leaky epithelium of rat small intestine is a transcellular one.

[An ultrastructural study of the apical cytoskeleton of the epithelial cells in the frog bladder with an ADH-dependent and an ADH-independent increase in osmotic permeability].

Immunocytochemical methods of electron and confocal microscopy were applied for studying the primembrane actin cytoskeleton in the frog urinary bladder granular cells, following the two actions: under the increased vasopressin-induced water permeability, and following autacoid removal by multiple changes of the Ringer solution around the serosa. In both cases similar changes have been revealed in the structure of the apical cytoskeleton and, in addition, a decrease in the density of its actin filament distribution was noticed.

[The ultrastructural characteristics of the epithelial cells in the frog bladder under the action of vasopressin and in a vasopressin-independent increase in permeability for water].

In experiments on isolated frog urinary bladders it has been found that the low basal level of water permeability in the absence of arginine-vasopressin (AVP) could be significantly increased when the serosal solution was changed several times every 15 min for a fresh Ringer solution. The electron microscopic study of these cells by the freeze-fracture technique showed that the enhancement of water permeability by AVP-independent manner was related to the appearance of intramembranous particle aggregates in luminal membrane of granular cell, that are usually observed only under the action of AVP. The immunocytochemical experiments with monoclonal antibodies against actin revealed the similarity in intracellular actin distribution under the action of AVP and AVP-independent increase of water permeability.

[An analysis of the structural characteristics of the tight junction of the enterocytes of the rat small intestine during nutrient absorption (immunoelectron microscopic research)].

To analyze structural changes of intercellular relationships of the enterocytes during glycine, glucose, and triolein absorption the structural and immunocytochemical methods of electron microscopy were used. The study was carried out on the proximal part of the rat small intestine in acute and chronic experiments. In the acute ones glucose or glycine solutions (both of 10 and 40 mM) or triolein emulsion (0.

[Tubular structures in Mycoplasma gallisepticum and the localization of a tubulin-like protein].

In all the strains of M. gallisepticum investigated, a protein with apparent molecular weight 40 kDa was revealed by immunoblotting with polyclonal anti-calf brain tubulin antibodies and monoclonal anti-chicken alpha-tubulin antibodies. In other 8 investigated Mycoplasma species no positive reactions with the same antibodies were found.

[Action of UV radiation on the surface of mammalian immunocompetent cells. III. Ultrastructural changes in the glycocalyx of mouse lymphocytes].

The outer perimembrane layer of murine spleen lymphocytes were studied with electron microscopy. Mice were treated with short-wave (254 nm) and long-wave (365 nm) ultraviolet radiation in isoeffective lethal doses. The other perimembrane layers were stained with Alcian blue and Ruthenium red.

[Changes in the form and ultrastructure of white erythrocyte ghosts during sealing and phthalocyanine dye sorption].

A study was made of the shape and ultrastructure of human erythrocytes unsealed and resealed for sucrose. The unsealed white ghosts assume unregular ameboid-like shapes. After resealing they acquire more regular spherical forms; the sub-membrane layer is dissociated, the plasma membrane undergoes numerous deformations.

[Electron microscopic study of the surface of nonirradiated and UV-irradiated human blood lymphocytes].

The action of the short-wave ultraviolet radiation (UV, 254 nm) upon the outer perimembrane layers (OPML) of the human blood lymphocytes was studied with the aid of electron microscopy. The alcian blue and ruthenium red dye was used for the contrasting of the OPML. The UV-exposure of cells in shown to lead to the diminution of the dye-adsorbing cell surface as well as to the change of the nature of the observed OPML structures.

[Form of red and white human erythrocyte ghosts and the ultrastructure of the internal perimembrane layer].

The shape of red and white ghosts and the ultrastructure of the inner perimembrane layers have been studied. The cytoplasmic perimembrane layer is proved to have a fibrous lattice-like structure. The ghosts with a great amount of hemoglobin have ellipsoid or deformed circular shapes.