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Biomedical subjects

N Arena

Publications and source records attributed to N Arena.

At least 37 records · Page 2Linked to original sources
PubMed1992

Effects of spermidine synthase inhibition in cultured chick embryo fibroblasts.

The administration of bis-cyclohexylammonium sulfate (BCHS), a spermidine synthase inhibitor, to in vitro cultures of chick embryo fibroblasts caused a decrease in cellular spermidine levels and an increase in putrescine and spermine. Cell proliferation rate and DNA synthesis were also inhibited. As protein synthesis did not change, it would seem that low levels of cellular spermidine inhibit cell growth depressing DNA synthesis.

Animals↗
PubMed1992

Modulation of phenotype and cytoskeleton architecture by interleukin-1 alpha in human osteoblast-like cells in vitro.

Interleukin-1 alpha, a growth factor produced by macrophages as well as many other types of cells, is able to modulate biosynthetic activities in bone cells. In this work, the authors show that the administration of interleukin-1 alpha to osteoblast-like cells in vitro induces a marked change in cell morphology, which becomes dendritic, with a smaller cellular body and numerous prolongations. The morphological changes are also accompanied by an altered expression in the pattern of cytoskeleton proteins.

Cells, Cultured↗
PubMed1991

Characterization of the cytoskeleton in human normal and otosclerotic osteoblast-like cells.

The localization and distribution of some cytoskeletal protein components were studied by immunostaining methods in normal and ostosclerotic osteoblast-like cells. The protein components investigated were microtubules (beta-tubulin), intermediate filaments (vimentin), microfilaments (actin and myosin) and structural proteins (alpha-actinin and fibronectin). Although the mechanism is not yet clear, the alterations observed in the pathological cells could well play a role in the expression of otosclerosis.

Actinin↗
PubMed1990

Cytoskeletal and DNA synthesis modification by concanavalin A in embryonic fibroblasts maintained in serum-free and serum-added medium.

The administration of lectin concanavalin A (Con A) to in vitro cultures of chick embryo fibroblasts caused dose-dependent changes in cell shape, cytoskeleton network and DNA synthesis. After 6 hrs. even a low doses of Con A produced evident effects in serum-free cultures, whereas higher doses were required to cause alterations in cells cultured in serum-added medium. As the sugar competitor mannoside abolishes the effects, it would seem that the lectin acts by binding to transmembrane receptors and that the fibronectin present in the serum engages the receptors so that they are not available to Con A.

Animals↗
PubMed1990

Restoration of a normal phenotype, microtubular pattern and DNA synthesis in embryonic fibroblasts concanavalin A pretreated.

The present research investigated the time required for reconstructing normal microtubular pattern and the phenotype of cells after short-term (30 min.) and long-term (24 hrs.) pretreatment with the lectin concanavalin A (Con A). Short-term pretreatment led to the formation of incomplete tubules within 2 and 24 hrs. in cells cultured in 199 medium alone. The addition of serum to the medium reversed the globular phenotype and allowed the formation of normal microtubules, even after prolonged pretreatment with Con A. Whereas long-term Con A treatment provoked a reduction in DNA synthesis in 199 alone, in serum-added 199 the percentage of 3H-thymidine incorporation of treated cells tended to reach that of controls over time.

Animals↗
PubMed1990

Effects of lectins on cytoskeleton and morphology or cultured chick embryo fibroblasts.

The microfilaments and microtubules of cultured chick embryo skin fibroblasts were studied in the presence of exogenous lectins by an indirect immunofluorescence technique. Lectin treatment induced modifications in the arrangement of myosin, actin and tubulin, determined depolymerization of the proteins and caused changes in cell shape and size. The results suggest that the interaction between lectins and their specific membrane receptors triggers a series of changes in the cytoskeletal pattern via transmembrana as yet unknown mechanisms and that these are responsible for the alterations in cell shape and size.

Actin Cytoskeleton↗
PubMed1987

[Angiosarcoma of the breast].

Two cases of angiosarcoma of the breast observed in 1981 and 1982 are reported; one of these is still living, but with local recurrence. The pathogenesis, classification, prognosis and therapy of this malignant tumor are analysed. The review of the literature and personal experience seem to suggest that the treatment of choice should be surgical with complementary radiotherapy.

Adult↗
PubMed1987

Cybrids and heterokaryons PEG-induced between D. discoideum amoebae and mouse fibroblasts.

Optimal conditions for fusion of Dictyostelium discoideum amoebae with mouse fibroblasts using polyethylene glycol (PEG) are described. Three different kinds of experiments were done to look for the ways to obtain new cell lines heterokaryons or cybrids. In all cases, the final products of the fusion were cells showing new features, still viable for at least one week. To detect the cell membrane fusion, samples were observed by scanning electron microscope (SEM).

Animals↗