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P Pippia

Publications and source records attributed to P Pippia.

At least 55 records · Page 3Linked to original sources
PubMed1985

Characterization of tumor cell lines from a spontaneous rat sarcoma expressing an endogenous retrovirus.

We have characterized various biologic, immunologic and growth properties of several cell lines established from a spontaneous rat sarcoma that was discovered more than 60 yr ago. The tumors consisted of mixed cell types with no detectable host cellular immune response. Cultures derived from single-cell clones of the parental cell line were non-invasive but highly tumorigenic even in adult rats. The cultured cells spontaneously released replication-competent endogenous rat type C virus which did not carry a transforming gene in its genome. Since normal cells from the same rat strain did not produce a retrovirus, it is possible that production of the endogenous retrovirus may have triggered specific cellular changes necessary for the oncogene expression and development of this tumor.

Animals↗
PubMed1983

[Electron microscopic features of neoplastic cells (SGS-3A) cultivated in agar].

The agar suspension culture method was applied to enrich for neoplastic cells in cultures of a cellular strain (SGS-3) derived from Sarcoma Galliera. This method suppresses the growth of normal cells without impairing colony formation by neoplastic cells. The analysis by electron microscopy of colonies of SGS-3A cells cultured in agar medium shows that cytoplasmatic bridges are present in the regions of cell-cell contact.

Agar↗
PubMed1981

[Preliminary reports on homologous and heterologous intercellular adhesion in normal and neoplastic cells cultured in vitro].

In our researches on the molecular meccanisms of cellular adhesion and density dependence inhibition we observed the SGS-3A neoplastic cells show a cell-cell adhesion higher than the homogenetic fibroblasts. This adhesion increases in single cells prepared with EDTA rather than Trypsin. Specific and non specific intercellular adhesion assays demonstrate that ligand molecules of coat of neoplastic cells are strongly trypsin-sensitive; on the contrary ligand molecules of coat of fibroblasts are more trypsin-resistent.

Animals↗
PubMed1981

Determination of adhesive rate constant in normal and neoplastic homogeneic cells.

The adhesive rate constant (ARC) of neoplastic SGS-2 cells which have a low contact inhibition, is remarkably higher than that of normal homogeneic fibroblasts. This is in contrast with the mutual adhesion theory which states that the loss of contact inhibition is strictly related to the loss of cell recognition and consequently to the loss of cell adhesion capacity.

Animals↗
PubMed1981

[Effect of iodoacetamide on cell-cell adhesion of fibroblasts in the rat].

The -SH groups of rat fibroblasts of cell-coat were blocked with Iodacetamide. This substance interferes negatively on the homologous intercellular adhesion of the tested cells, with a proportional effect related to the concentration used. The meaning of -SH groups on the cell-cell interactions is discussed.

Animals↗
PubMed1980

[Distribution of the O-groups of E. coli strains isolated from urinary infections in Sardinia].

We refer to the results of the serological identification of E.Coli strains from urinary tract infections and from faeces of healthy subjects in Sardinia. The serological groups more frequently found in urinary tract infections (06, 018, 075) of our geographical region one similar to those of other authors. The fact that some of the 0-groups (02, 018, 075, 04) which occurred more frequently in urinary tract infections are also the most prevalent among faecal strains, supports the theory of prevalence; the presence of 0-groups (06, 01, 011, 09) in urinary infections alone does not leave out a specific disposition towards growth in the urinary tract of the same strains.

Escherichia coli↗
PubMedDate not supplied

[Antiproliferative activity of cimetidine and a copper-cimetidine complex on rat fibroblasts cultured in vitro].

Cimetidine is an active H2-receptor antagonist which, combined with other drugs, has antitumor effect. It has been recently shown that some drugs complexed with copper increase their inhibitory effect on tumor growth and promote cell differentiation. In the present investigation we analysed the modifications of some cell proliferation parameters (mitotic, labelling and apoptotic indices and DNA synthesis) by microfluorometry and autoradiography in 2-day low and high cell density fibroblast cultures in presence of 20 microM cimetidine or copper-cimetidine complex. In low density cultures, a more intense proliferation activity was found while in the high density ones there was accumulation of 4c and 8c polyploid cells. The highest antiproliferative effect was found in low density cultures in presence of copper cimetidine complex, which caused mitotic anomalies and increased chromocenters. Simultaneous evaluation of nuclear DNA content and 3H-T labelling indicated the extension of G1 and G2 phases, followed by a lower cell proliferation and degeneration.

Animals↗
PubMedDate not supplied

The action of cisplatinum (cis-DDP) on the postnatal growth of the rat liver. Cytokinetics and ultrastructural studies.

The early and late effects of cis-DDP treatment on liver cell kinetics were analyzed after its intraperitoneal injection into 17-day old rats. Frequency of binucleate hepatocytes, cellular DNA content distribution, 3H-thymidine labelling and ultrastructure of the nuclei were analyzed. Two days after treatment, a block of mononucleate hepatocytes in the S phase and in the G2 phase was demonstrated by the increase of intermediate 2c-4c and 4c DNA values in the absence of changes in 3H-thymidine labelling; 8c binucleate cells, which are essential for the formation of tetraploid mononucleate cells, were not found. In cell nuclei, large areas of more condensed chromatin appeared, perhaps providing further evidence for a G2 block. Seven days after treatment, there was a tendency to catch up with the normal situation, as shown by the unblocking of the S phase in mononucleate cells indicated by both cytophotometry and autoradiography. The presence of 8c binucleate cells and 4c-8c mononucleate cells indicates that 4c mononucleate hepatocytes are either diploid cells in the G2 phase or true tetraploid G1 cells. The decrease in the heterochromatin areas and the appearance of hypertrophic nucleoli demonstrate an increase in the metabolic activity of the nuclei. Thirty six days after treatment, the incidence of different DNA hepatocyte classes and the 3H-thymidine labelling were already similar in control and in treated rats.

Aging↗