[Some molecular and genetic properties of progenitor cells in sarcomas induced with foreign body].

One of the important questions in understanding the mechanisms of carcinogenesis induced with foreign body (or plastic carcinogenesis), is a question about normal progenitor cells in sarcomas (FB sarcomas) appearing in close proximity to the plastic plate implanted under the skin of an experimental animal. There is an assumption in literature that progenitor cells in FB sarcomas originate from vascular endothelium cells feeding a connective tissue capsule that forms around foreign body. In our research, we studied mRNA expression of one of the endothelial cell markers--receptor VEGFR2/FIk1--and growth factor VEGF-A, which interacts with it, in precancerous cells of FB sarcomas in mice.

[Cells of endothelial lineage (or endothelial-like cells) as possible progenitor cells of sarcomas induced by implanted foreign body].

This study is dedicated to the problem of the origin of progenitor cells of sarcomas induced by implantation of a foreign body (polyvinilchloride plates) to mice. It is known that such cells are found among the cells of the monolayer covering the surface of implanted plate without any signs of tumor growth in 6 and more months after implantation. We studied the existence of endothelial features of mesenchymal type cells that had been grown by culturing the cells from the implanted plate surface in 9 and 14 months after implantation.

Carcinogenesis induced by foreign bodies.

This review deals with the contemporary investigations of carcinogenesis induced by foreign bodies. The main attention is given to the interactions of macrophages with an implanted foreign body and their possible role in tumorigenesis.

Multifunctional Ti-(Ca,Zr)-(C,N,O,P) films for load-bearing implants.

Films of Ti-Ca-P-C-O-(N), Ti-Ca-C-O-(N) and Ti-Zr-C-O-(N) were deposited by DC magnetron sputtering or ion implantation-assisted magnetron sputtering of composite targets TiC0.5 + 10%Ca10(PO4)6(OH)2, TiC0.5 + 20%(CaO + TiO2) and TiC0.

Design, characterization and testing of Ti-based multicomponent coatings for load-bearing medical applications.

A comparative investigation of multicomponent thin films based on the systems Ti-Ca-C-O-(N), Ti-Zr-C-O-(N), Ti-Si-Zr-O-(N) and Ti-Nb-C-(N) is presented. TiC(0.5) + 10%CaO, TiC0.

Substrate-induced polarisation of cultured epitheliocytes and fibroblasts: non-reactivity of Ras-transformed cells.

Non-transformed epitheliocytes and fibroblasts undergo modulations between the less polarised and more polarised phenotypes depending on the nature of the substrate. In contrast, transformed cells express polarised phenotype regardless of the substrate.

[Expression of intermediate filament proteins in MDCK cells cultured in the three-dimensional gel in the presence of cytokine HGF/SF].

An immunomorphologic study was made of expression of intermediate filament proteins--keratin and vimentin--in the structures formed in branching tubulogenesis of Madin-Darby Canine Kidney epithelial cells (MDCK, clone 20), cultured in three-dimensional collagen gel in the presence of the "scatter factor" (HGF/SF). An improved method of parallel immunostaining of the whole branching structures and of their cryostat cross-sections was used. It was shown that both the discoid epithelial cells, forming walls of tubules with inner clear spaces, and the fibroblast-like cells invading the collagenic gel coexpressed keratin and vimentin.

Early and late stages of foreign-body carcinogenesis can be induced by implants of different shapes.

Implanted foreign bodies of certain shapes, especially large non-perforated polymer films, induce subcutaneous sarcomas in a high percentage of mice and rats; in contrast, implants of other shapes, e.g., perforated or minced films or Millipore filters with 0.

[Two-stage carcinogenesis induced by foreign bodies].

Replacement of non-perforated polyvinylchloride films 3.5 months after implantation to CBA mice by perforated polyvinylchloride films or by millipore filters with 0.45 micron pores led to the development of sarcoma at the site of implantation in 37.

[Stimulation of grafting of a minimal number of tumor cells after their transplantation into the subcutaneous "air pouch"].

Transplantation of the minimal number of cultivated cells of sarcoma line 84 into CBA mice gave higher percentage of tumours when these cells were inoculated into the subcutaneous "air pouch" in comparison with the standard subcutaneous unoculation.

[Fibronectin in cultured mouse sarcoma cells induced by foreign bodies].

Indirect fluorescence was used to study distribution of fibronectin in cultured cells of 5 mouse foreign body-induced sarcomas (PS-4, PS-84, PS-100, PS-103, PS-130) and cells of early (2-3 months postimplantation) capsules surrounding implanted plastic films. Accumulation of pericellular or matrix fibronectin in dense cultures compared to sparse ones was noted in all the lines except PS-84. In confluent cultures of these lines, a three-dimensional fibrillar network of fibronectin typical for fibroblast-like cells was observed.

Tumorigenicity of sarcoma cells is enhanced by the local environment of implanted foreign body.

The local effect of an implanted foreign body (polyvinyl chloride film) on the growth of transplanted syngeneic sarcoma cells was studied. Two cell lines derived from CBA mouse sarcomas induced by subcutaneously implanted polymer films were used. Small numbers of tumour cells were subcutaneously transplanted to CBA mice in several ways (1) as a suspension into normal tissue (control group); (2) as a suspension into the capsules around previously implanted polymer films; (3) attached to the surface of polymer films, and implanted with these films.

[Histogenesis of sarcomas, induced by plastic films, in murine radiation chimeras].

Sarcomas were induced in radiation chimeras CBA/CBAT6T6 by subcutaneous implantation of plastic films 13 months after the irradiation and donor bone marrow transplantation. Of the 12 tumours examined, 11 possessed host kariotype and one--donor karyotype. Development of connective tissue cells from the bone marrow precursors presumably played no significant role in the histogenesis of plastic sarcomas.