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Biomedical subjects

G Neupert

Publications and source records attributed to G Neupert.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Intermediate filaments in cells of hyaline cartilage].

After different fixation procedures great numbers of bundles of intermediate cytofilaments, 10 nm in thickness, could be detected in electron micrographs of chondrocytes from Processus xiphoideus of the rat, from the articular cartilage of the rabbit and from chondrocyte cultures from the articular cartilage of the rabbit. By means of the indirect immunofluorescence technique with monoclonal antibodies they could be clearly defined as vimentin.

Animals↗
PubMed1985

Connective tissue reactions in early phases of spontaneous regression of experimental malignant histiocytomas. An electron microscopic study.

Interactions between cancer and host are said to comprehend immunologic processes and stromal reactions including an angiofibroblastic response. We studied the latter phenomenon in spontaneously regressing experimental malignant histiocytomas produced by inoculation of an established macrophage-like cell line (WEHI-3) into baby rats. Light and electron microscopic investigations of the tumor tissue showed that there was a clear proliferation of fibroblasts and capillary vessels beginning from the 8th-10th day of the experiment. The vascular structures seemed to be somewhat changed and fibroblasts often displayed close contacts to tumor cells. The significance of these connective tissue reactions is discussed and, finally, the observations led to the conclusion that the angiofibroblastic reaction in the malignant histiocytoma model presented here may actively contribute to tumor breakdown and should not be interpreted as being only a secondary phenomenon after irreversible damage of tumor cells.

Animals↗
PubMed1985

[Scanning electron microscopy study of cell growth on mechanically produced biovitroceramic and carbon glass in vitro and in vivo].

New machinable glass ceramics were tested for the application in middle ear surgery in vitro and in vivo. This ceramic consists of a glass phase and a glimmer phase. Fibroblasts and epitheloid cells seated on the test material attach to it, spread and form a confluent monolayer. From our findings on the behaviour of cell populations in vitro we can conclude that the implanted material is biocompatible. After implantation into the middle ear of rabbits, irritation-free settling was verified by the existence of a thin epithelium layer and a direct connection between bone and implant. Glass carbon did not yield equally satisfactory results.

Animals↗
PubMed1984

Adhesion, spreading and growth of animal cells on the surface of glass ceramic Ap40--a contribution to the cell compatibility of dental permanent hard tissue implants.

Cells of different cell lines on the surface of glass ceramic Ap40 responded in the manner of reversible vacuolization in the cytoplasm. Whereas the eluate of bulk glass ceramic did not produce toxic effect on cell populations in vitro, the eluate of pulverized glass ceramic Ap40 caused a toxic reaction, the effect being dependent on concentration and incubation time. Although cell attachment, spreading and proliferation of fibroblast-like and epithel-like cells on glass ceramic surfaces are delayed when compared to glass and polystyrene the cells are adhering to a confluent monolayer.

Animals↗
PubMed1984

Growth of fibroblasts and epithelioid cells on a new machinable bioactive glass ceramic in comparison with non-reactive materials.

In this study scanning electron microscopy (SEM) was used to investigate the substrate attachment, cell spreading and growth properties of fibroblasts and epithelioid cells on a newly developed machinable bioactive glass ceramic. The morphogenetic reactions of cell cultured on bioactive ceramic were compared with those of identical cells cultured on non-reactive glass and vitreous carbon. The adhesion, subsequent spreading and the growth appearance of fibroblasts and epithelioid cells on the surface of machinable glass ceramics are similar to those on nonreactive materials. Our findings concerning the behaviour of cell populations in vitro on the surface of a new machinable glass ceramic allow the conclusion that this implant material is adhesive for cells and biocompatible.

Animals↗
PubMed1984

[Behavior of cultured cells on the surface of A12O3 ceramics of different consistencies].

The in vitro reactions of mesenchymal cell populations on different powdery and cubical Al2O3 ceramic implants are described compared with those on glass. The ceramics differ because of different compounds and surface processing. The physiologic eluate of the contaminated ceramics induce no cytotoxic and no antiproliverative effect on the single layer population in vitro. The cells settle itself on the ceramic surface. They constidued a confluent cell layer about the whole surface by proliferation (morphogenetic reaction). No difference in the behaviour of the fibroblast-like cells was observed referable to the chemical compound or the surface of the Al2O3 ceramics. The aluminium oxide ceramic presents itself as an absolutely bioinert material despite of strong soiling.

Aluminum↗
PubMed1983

Experimental tumors with features of malignant histiocytomas. Morphological studies on neoplasms produced by inoculation of an established macrophage-like cell line (WEHI-3).

Soft tissue malignant histiocytomas are thought to be a histologic variant of malignant fibrous histiocytomas. By means of an established macrophage-like cell line (WEHI-3) we produced experimental tumors with light microscopic features of malignant histiocytomas. In spite of repeated subculturing of WEHI-3 cells and their derivatives the 6 tumor generations received by cell transplantations were remarkably constant in regard of their light and electron microscopic morphology. This was in contrast to preceding experiments with an established fibrosarcoma cell line. Electron microscopically they were never to be identified in the histiocytoma-like tumors so that these neoplasms could virtually not be considered as members of the malignant fibrous histiocytoma group. Our results support the idea that malignant fibrous histiocytomas and malignant histiocytomas of the soft tissues arise from undifferentiated mesenchymal cells and emphasize that monocyte-derived histiocytic tumors may appear as soft tissue histiocytomas although they are more related to malignant histiocytosis.

Animals↗
PubMed1983

Modification of fibroblastic glycosaminoglycan pattern by soluble factors obtained from sensitized lymphocytes.

Lymph node cells were obtained from BCG-sensitized guinea pigs and cultured without (C) and with (Ag) PPD challenge. The dialyzed lymphocyte (LC) supernatants were added to the medium of monolayer cultures of embryonic rat fibroblasts. They were assayed at different cell densities and in the presence and absence of serum. The following results were obtained: Glucose consumption was increased but the cell counts were reduced with both the types of LC supernatants, suggesting a cytotoxic effect. Small increases of cell counts were observed with Ag supernatant in high density fibroblasts in absence of serum. Glycosaminoglycan levels per cell in medium and monolayer were similarly enhanced by both the types of supernatants in presence of serum. As an exception, Ag supernatant reduced cell glycosaminoglycans (GAG) at low cell density. In the absence of serum at low cell density, the increase of medium and cell GAG was markedly higher with Ag supernatant. The GAG pattern of the fibroblast media was scarcely influenced by LC supernatants. In the cell monolayer, however, interesting changes have been observed. Increases of HS and DS were produced by C-supernatant in low density fibroblasts as well as by C- and Ag-supernatants in high density fibroblasts with serum. HS was also increased by C- and Ag-supernatants in serum-free low density fibroblasts. Increases of HA and CS were produced by Ag supernatant in low density fibroblasts with serum. The possible significance of these changes is discussed with regard to chronic inflammation.

Animals↗
PubMed1983

Persistence of Acholeplasma laidlawii in an established cell line RL 19. 1. Host-parasite morphology.

The cell-parasite relationship of epitheloid cells from the established liver cell line RL 19 persistently infected with Acholeplasma laidlawii was studied by transmission electron microscopy and scanning electron microscopy. The predominantly filamentous, branched A. laidlawii were arranged horizontally on the cell surface between microvilli at the cell margin. The cell adhesion, spreading, growth pattern and cell surface shape were not altered in relation to uninfected cultures of the same cell line.

Acholeplasma laidlawii↗
PubMed1983

Morphogenesis of cell-to-substratum adhesion and spreading on Ni-Cr-alloys. A scanning electron microscopic study.

A scanning electron microscopy (SEM) analysis has been performed on the adhesion, spreading and growth pattern of fibroblastoid and epitheloid cells on Ni-Cr-alloys as compared to glass substrates. The attachment is initiated by filipodial contact of monolayer cells with the glass as well as alloys, and subsequent radial spreading occurs by the gradual peripheral extension of the broad lamellipodium followed by a general cell flattening. When cultured under identical conditions monolayer cells reach confluence at the same time on glass and alloy surfaces, respectively. The results show that the fibroblastoid and epitheloid cells form stable contacts between the cell surface and the alloy in the same manner in which the cells adhere to the surface of glass. The cells migrated and proliferated on the surface of alloys and covered the surface of the substratum.

Animals↗