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N A Tregubova

Publications and source records attributed to N A Tregubova.

8 recordsLinked to original sources
PubMed1990

[A method for the chemical treatment of cells for the purpose of the subsequent study of the same cell culture preparation by light, scanning and transmission electron microscopy].

Cells cultured on transparent conductive substrates (glass coated with indium oxide) were fixed with aldehyde and osmium tetroxide and then treated with tannic acid, uranyl acetate and lead citrate. The same cell culture preparation could be sequentially studied by light microscopy (in water immersed condition), SEM (after dehydration and critical point drying) and TEM (after embedding in an epoxy resin). This method ensures the preservation of intact cell morphology, cell surface topography and intracellular structures. The treatments used render the cells conductivity and permit to carry out successfully SEM of uncoated cells cultured on conductive substrates. This method also provides a higher contrast of TEM images.

Animals↗
PubMed1986

[Ultrastructural anomalies of the desmosomal contacts in monolayer transformed cultures].

The ultrastructure of cell-cell desmosomal contacts and their cytoskeletal components in the cellular monolayer of transformed epithelial cultures is studied. It is suggested that asymmetry of the desmosomal contact formation, the formation of hemidesmosome-like structures on the lateral surface of one of the contacted cells and defects of cytoskeletal desmosomal components are related to transformational changes in the functionally different contacted cells.

Animals↗
PubMed1983

[Ultrastructure of L-line lipoblast-like cells during cloning in a medium with a high serum concentration].

The ultrastructure of lipoblast-like cells produced by clones of transformed culture of strain in the medium with an increased (60%) concentration of bovine serum was studied. The aim of using the stimulator rich in adipogenous factors was the elucidation of the origin of lipid accumulation in some of cell types during heterogeneous differentiation of clones. In these conditions non-differentiated lipoblasts assumed the fine structure of mature lipid cells. The statement of the marker significance of lipid accumulation in non-differentiated cells of the clones and the conversion of these cells under the influence of non-specific stimulator to the mature lipocytes confirms the data on conservation of over-all cytogenetic potentials and the capacity of their realization in the cells of transformed cultures. It is suggested that the increased concentration of bovine serum in the cultural medium not only stimulates differentiation (by any way determined cells), but is also capable of acting on the stem elements produced by the clone. In that case the influence of the stimulator on the trends of heterogeneous differentiation is not unlikely.

Adipose Tissue↗
PubMed1982

[Cellular ultrastructure of a cloned L-line culture].

A study of the fine structure of cells obtained from the transformed cloned culture of strain L, that have developed from a single cell, demonstrated several different cell types. The clones contained both non-differentiated and poorly-differentiated cells. The presence of morphotypical signs in the poorly-differentiated cells allowed to reveal some cell clone types and the direction of their specialization process. The study confirms the idea on the presence of the stem cell elements in the transformed cell culture of strain L causing the heterogenous way of cytodifferentiation and determining the long-term stability of cell polymorphism in this cell strain.

Animals↗
PubMed1980

[L line cell differentiation. Histochemical and electron microscopic studies].

In a medium supplemented with 60 per cent large cattle serum, part of the cell population of L-transformed culture was seen to be differentiated into mature lipocytes. The formation of structures similar to normal fat tissue took place in the same conditions, provided a reduced quantity of the seeded cells was used. The cell differentiation was accompanied with a decrease in acid phosphatase and non-specific esterase activities. The ultrastructural study has demonstrated a suitable preservation of cytoplasmic structures and a domination of the rough cytoplasmic reticulum compared to the control cell cultures where free ribosomes and polysomes predominated.

Acid Phosphatase↗
PubMed1979

[Effect of chemical carcinogens on the ultrastructure of cultured differentiating myogenic cells].

The electron microscope studies have been carried out on primary monolayer tissue culture obtained from body tissues of rat and C3H mouse embryos. The cells of tissue culture were mainly myoblasts and fibroblast-like cells. The cultures were treated with two different carcinogenic substances--benz(a)-pyrene (BP) and methylnitrosonitroguanidine (MNNG). The changes were uniform and showed some alterations in formation of cell complexes, the inhibition of development and maturing of muscle elements, and distrophy of cytoplasmic organelles. The revealed distinction in morphological reaction of myogenic cells to the effect of BP and MNNG were wave-like myofibrillar structures in MNNG-treated cultures.

Animals↗
PubMedDate not supplied

[Ultrastructural organization of carcinoma Lewis (3LL) cells during cisplatin resistance formation].

The electron-microscopic analysis of the morphological status of 3LL (Lewis) carcinoma tumour cells in the process of cisplatin resistant phenotype formation has been performed. It was shown that selection of tumour cells forming cell clones characterized by more complicated nuclear and cytoplasm organization took place. The tumour cells had the diffused nuclear chromatin; nuclear envelope had the numerous pores with expanded diaphragms. The prominent nucleoli consisted of the active centres surrounded by considerable areas of the condensed nucleolar chromatin. Cell cytoplasm contained the well-developed Goldgi complex and the numerous well-structured myelinoid formations in the form of dense-wrapped concentric membrane structures. The obtained data can morphologically confirm the hypothesis of Gately D.P. and Howel S.B., 1993, thain the process of resistant phenotype formation the tumour cells can create the cellular mechanisms to remove the drug from the cell and to correct the damages of the cellular nucleus and cytoplasm.

Animals↗