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Biomedical subjects

S M Troianovskiĭ

Publications and source records attributed to S M Troianovskiĭ.

At least 19 recordsLinked to original sources
PubMed1992

[Dependence of keratin No. 17 distribution on the degree of malignancy of bladder tumors].

Keratin No 17 expression (Mab E3) correlated with the stage and degree of malignancy of transitional-cell bladder carcinoma (TCC). Antibodies to keratin No 17 stained only the basal layer of the tumour growth in the TCC I while in TCC II-III positively stained cells were found everywhere in the tumour and staining was diffuse. Immunostaining for the simple keratins No 7, 8, 18, 19 in TCC I-III was diffuse. Distribution of keratin No 17 as well as that of the simple keratins was not regular in the metaplastic and anaplastic forms of TCC. Thus, the expression of keratin No 17 and simple keratins may serve an objective criterion of the tumour progression stage.

Carcinoma, Transitional Cell↗
PubMed1987

[Expression of vimentin and prekeratins in solid and ascites variants of Zajdela hepatoma].

Using indirect immunofluorescence with monoclonal antibodies against prekeratins and vimentin, the contents and intracellular distribution of these proteins have been investigated in Seidel hepatoma cells. In ascitic tumour, cells were organized in multicellular unilayer spheric or ellipsoid complexes with an inner cavity. Such complexes have been found to express intracellular vimentin and chaotically distributed prekeratin filaments. One of the constituents of the normal epithelial basal membrane--laminin was not found on the basal surface of cellular complexes but was localized in their inner lumens only. The expression of vimentin and prekeratin filaments was preserved in metastatic tumour cells found in paratracheal lymph nodes and in the majority of solid tumour cells induced by subcutaneous cell injections. In both cases tumour cells did not form regular morphological structures and laminin was visualized as extracellular granules and short fibrils. In several cases subcutaneous injections of Seidel hepatoma cells gave rise to adenocarcinomas. Prekeratin filaments in these tumours were localized predominantly under cellular membranes. Laminin "membranes" outlined the basal surface of adenomatous structures. Vimentin in these cellular structures was completely absent. It is suggested that vimentin expression in Seidel hepatoma cells was suppressed with morphological normalization of tumour structures manifested in the regular distribution of intercellular contacts and in basal membrane reconstitution.

Animals↗
PubMed1987

[Changes in the expression of prekeratins with molecular weight of 55 and 40 kD in monolayer epithelium during skin morphogenesis in rats].

It has been shown by indirect immunofluorescence using monoclonal antibodies against adult rat simple epithelial prekeratins with the molecular weight of 55 kD (PK55) and 40 kD (PK40) that PK55 was expressed in the covering ectoderm until the 11th day of the antenatal period. PK55 expression markedly increased in ectodermal cells lining the heart region, with PK40 appearing in the same cells on day 11. Beginning from the 16th day gradual loss of both prekeratins started with the parallel formation of squamous differentiated epidermis. These proteins were retained in the outer layers of peridermal cells and in some cells of the basal layer (probably Merkel cells). PK55 was re-expressed on the 18th day in cells migrating into dermal layer during hair folliculi formation. PK55 disappeared again in mature folliculi. Thus, a correlation between distinct morphogenetic events and PK55 and PK40 expression has been found.

Animals↗
PubMed1987

[Prekeratin expression of simple epithelia in the cells of long-term cultured epithelial lines of the rat liver].

Prekeratin of simple epithelia with m.m. 55 kD (PK55) was found in all the studied tumorigenic and non-tumorigenic liver epithelial cell lines of the IAR series by means of indirect immunofluorescent methods in combination with corresponding monoclonal antibodies. The most prominent expression was observed in some tumorigenic cell lines. Expression of PK55 was reversible--the cells lost prekeratin in low density cultures. It has been found that the synthesis of prekeratins with m.m. 49 kD (PK49) and 40 kD (PK40) began on reaching higher cell densities than those needed for PK55 synthesis in IAR6-7 line. The PK40 appeared in cells spread on the substratum, while the PK49 was observed in upper poorly spread cells of ridges in multilayered dense cultures. Thus, the synthesis of prekeratins is not constitutive at least for some types of epithelial cells. Specific cell-to-cell interactions are presumably needed for each particular prekeratin synthesis induction.

Animals↗
PubMed1987

[Detection of tissue-specific gene expression using an in situ hybridization method of histoblotting].

A version of in situ hybridization on the histological sections that is used for screening specific mRNA in tissues in proposed. Sections of the frozen tissue samples are prepared on the cryostatic microtome, placed on nitrocellulose filters and hybridized with labelled DNA-probes under the conditions of RNA blot hybridization. The proposed method ("histoblotting") was used to study the distribution of actin and alpha-phetoprotein mRNA genes in tissues of 15 and 21-day rat embryos. The possibility of studying mRNA (by hibridizations) and protein (by immunoenzyme staining) and making histological analysis simultaneously by histoblotting is demonstrated.

Animals↗
PubMed1987

[Intermediate filaments: structure, regulation of expression and possible function].

New data are reviewed on intermediate filaments, i.e. on one of the cytoskeleton components. Structural proteins of intermediate filaments, their enzymatic modification, filament-associated proteins and the peculiarities of filament assembly are dealt with. The regularities of expression of intermediate filament proteins in normal tissues are analysed, as well as during differentiation and cultured cell growth. In the final part of the paper possible functions of intermediate filaments are discussed.

Animals↗
PubMed1986

[Production and characteristics of monoclonal antibodies against individual prekeratins in simple types of rat epithelium].

BALB/c mice were immunized with intermediate filaments (IF) from the rat colon mucosa, and their splenocytes were fused with myeloma cells to obtain hybridomas. Specific antibody production was assessed by indirect immunofluorescence on cultured rat hepatoma 27 containing prekeratins. The clones that stained IF in hepatoma and not in fibroblasts were judged positive. Clones E3 and E6 were shown to produce monoclonal antibodies against prekeratin with molecular mass of 40 kD (PK40), while clones E2 and E7 produced antibodies against prekeratin with molecular mass of 55 kD (PK55). This was established by immunoblotting with 125I-protein A in cell lysates from the colon, bladder, and hepatoma 27. Only PK55 was revealed in liver and salivary gland lysates. The above proteins were not detected in esophagus, fibroblast and skeletal muscle cell lysates. The monoclonal antibodies make it possible to study individual prekeratin expression in embryogenesis, differentiation and neoplastic transformation of simple epithelium.

Animals↗
PubMed1985

[Role of microtubules and intermediate filaments in maintaining the shape of epithelial cells].

The role of microtubules and intermediate filaments in control of cell shape of cultured cells of hepatomas McA-RH-7777 and 27 was investigated. Indirect immunofluorescence with specific polyclonal antibodies against tubulin and monoclonal antibodies against prekeratin with molecular weight 49 kD and vimentin was used. Incubation of cells in colcemid, resulting in specific distribution of microtubules did not change either prekeratin or vimentin distribution in cells of both the hepatomas, but reversed polarization of elongated McA-RH-7777 cells. These data suggest that the effect of disruption of microtubular system on the cell shape is not mediated by alterations of intermediate filaments.

Animals↗
PubMed1985

[Immunomorphological study of the distribution of prekeratin with a molecular weight of 49 kilodaltons in various epithelial cells in rats].

Cryostat sections of various tissues of rat were stained using an indirect immunofluorescent method with monoclonal antibody against individual prekeratin with the molecular mass of 49 kilodalton (PK-49). Connective tissue endothelial cells, neurons, glia, haematopoetic tissue and smooth muscles were completely negative in this test. 46 morphological variants of epithelial structures were investigated. PK-49 was absent from all the stratified epithelia (epidermis, hair folliculi, oesophagus) but was expressed in virtually all simple epithelia of endodermal origin (exceptions: squamous lung alveolar epithelium and germinative epithelium of testis). There were negative (kidney tubules) as well as positive (bladder, mammary, glands) cell elements among mesodermal and ectodermal simple epithelia. High specificity of individual PK in respect to morphological variants of epithelia points out to the important role played by prekeratin-type intermediate filaments in morphogenesis.

Animals↗
PubMed1985

[Differences in the expression of prekeratin and vimentin in organ and monolayer cultures of rat hepatocytes].

Results obtained by the indirect immunofluorescence method employing specific monoclonal antibodies show that during the first 24 hours of cultivation in a monolayer there appears another protein of intermediate filaments--vimentin, which is a characteristic of most mesenchymal cells. At the same time, in the organ liver culture maintained in the same culture medium, no expression of vimentin was observed up to 5-7 days of cultivation. Vimentin was revealed only in cells that migrated from a tissuepiece to collagen. Besides the vimentin expression in these migrating cells and monolayer cultures of hepatocytes, a redistribution of prekeratin filaments took place: the cytoplasmic network appeared instead of thick fibers underlying membranes. The results of the present work suggest that the vimentin expression and the prekeratin filament redistribution in epithelial liver cells in vitro do not depend on the changes of natural humoral factors for the components of culture medium but are due to damages of the intact liver tissue structure.

Animals↗
PubMed1985

[Immunomorphological study of 1,2-dimethylhydrazine-induced carcinomas of the large intestine in rats using monoclonal antibodies to intermediate filament proteins].

Cryostatic sections of rat large bowel tumors induced by 1,2-dimethylhydrazine were stained with monoclonal antibodies against different proteins of intermediate filaments: (a) against prekeratin (mol. mass 49 000, PK49) found in many epithelial cells and (b) against vimentin, a constituent of intermediate filaments of mesenchymal cells. Immunofluorescence study showed that large bowel tumor cells as well as normal cells of this organ contain PK49 but not vimentin. High sensitivity of the method allowed one to clearly identify small invasive nodules and groups of tumor cells not visible in usual histologic preparations. Moreover, in some cases single atypical tumor cells were identified in tumor stroma and in the submucosal layer underlying the tumor, that were indistinguishable from normal mesenchymal cells at the light microscopy level.

1,2-Dimethylhydrazine↗
PubMed1984

[Hepatoma 27 cells and the epithelium of the large intestine in rats contain the identical set of prekeratin proteins].

It has been shown by means of the immunoblot technique in combination with monoclonal antibodies and peptide mapping that hepatocytes, hepatoma 27 cells, and rat colon enterocytes exhibit a common prekeratin protein with a molecular weight of 49 kD (PK49). This protein and vimentin, a protein contained by intermediate filaments of mesenchymal cells, share at least one antigenic determinant. The generally accepted procedure for prekeratin purification leads to a more or less pronounced degradation of PK49. The degree of degradation is dependent on the type of the tissue extracted. High heterogenicity of prekeratin polypeptides described elsewhere might be due partly to such a degradation process. In addition to PK49, hepatoma 27 cells, absorbing, goblet and proliferating cells of the colon demonstrated three more prekeratin proteins: two major (PK55 and PK40) and one minor (PK53). Monoclonal antibodies not reacting with PK49 do not recognize PK55, PK53 and PK40. PK55, PK49 and PK40 of hepatoma 27 are identical to the appropriate proteins of the colonic epithelium as judged by peptide mapping. Thus, the cells of the hepatocyte origin are able to synthesize the same prekeratins as the colonic epithelium.

Animals↗
PubMed1984

[Cytoskeletal reorganization in hepatocytes of the regenerating mouse liver].

The intracellular pattern of prekeratin and actin filaments has been studied on sections of mouse livers regenerating after CCl4 injury. Monoclonal antibodies against one of liver prekeratins and monospecific polyclonal actin antibodies were used in the indirect immunofluorescent test. The presence of alpha-fetoprotein and bile canaliculi antigen was also monitored during regeneration. In control livers, prekeratin and actin filaments formed thick bundles adjacent to plasma membranes. The cytoplasmic prekeratin network was unmarked. In contrast to the latter, the bright well developed intracytoplasmic prekeratin network and intracytoplasmic actin fibers were identified in the perinecrotic hepatocytes by the 3d-4th day of regeneration. This rearrangement of the cytoskeleton coincided in time with the appearance of alpha-fetoprotein and the loss of the bile canaliculi antigen in the perinecrotic hepatocytes.

Animals↗
PubMed1982

[Effect of fibronectin on morphology and cytoskeleton of cultured epithelial liver cells].

Unlike nontumorigenic IAR2 cells, no surface fibronectin was detected in tumorigenic epithelial liver cells, IAR2-31 and IAR6-IRT7A. The adsorption of exogenous fibronectin purified from rat plasma, onto the substratum before seeding cells led to varying results in different cell lines. IAR2 showed no morphological changes or changes in the actin cytoskeleton, but acquired a network of radially oriented fibronectin fibrils. Under the effect of fibronectin single IAR2-31 cells returned to normal in terms of both the morphology and actin cytoskeleton, as well as acquired radially oriented fibronectin fibrils. At the same time IAR2-31 cells in the sheet were characterized by a circular actin bundle which made them essentially differ from IAR2 cells. IAR6-IRT7A cells were found to lose the ability to return to normal on fibronectin-coated substrates.

Animals↗
PubMed1982

[Changes in the actin cytoskeleton during transformation and tumor progression in liver epithelium in culture].

Two patterns of actin distribution were revealed by indirect immunofluorescence in non-tumorigenic cell lines of cultured liver epithelium. The first one was represented by large marginal cable, lining the active edge of epithelial sheet. The second one was represented by numerous inner bundles randomly distributed in all cells. The following changes in actin pattern were detected in cultures of transformed epithelium: A) The reduction of inner bundles in all cells and the appearance of the marginal actin cable in central cells of the sheet, and B) The reduction of marginal cable and the presence of inner bundles, preferentially oriented along the longer axis of cells which became more polarized. In tumor cells, arising from transformed epithelium with A-type of actin pattern alteration, a secondary redistribution of actin bundles towards B-type occurred. Histochemical staining of such cells revealed a high activity of gamma-glutamyltranspeptidase, a marker enzyme for transformed cultures. The complete loss of actin bundles was observed in soft agar clone originated from cells with B-type alteration of actin pattern.

Actins↗