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Biomedical subjects

G Ivaldi

Publications and source records attributed to G Ivaldi.

At least 37 records · Page 2Linked to original sources

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↗

The characterization of hemoglobin Manitoba or alpha (2)102(G9)Ser----Arg beta 2 and hemoglobin Contaldo or alpha (2)103(G10)His----Arg beta 2 by high performance liquid chromatography.

Hb Contaldo with a His----Arg substitution at position 103(G10) of the alpha chain is a newly discovered unstable Hb variant observed in an Italian child. Its instability is probably due to the disruption of the hydrogen bond between alpha 103(G10)His and beta 108(G10)Asn. The structural variation in the core segment was determined through analysis of tryptic peptides from digests of the alpha X and oxidized alpha X (with performic acid) chains, which were separated by HPLC. Similar analyses were made for the alpha X chain of the rare Hb Manitoba in which alpha 102(G9) Ser is replaced by Arg. This variant was observed for the first time in an Italian patient, and was also studied in a member of a previously described Canadian family.

Amino Acids↗

Alternate organization of alpha G-Philadelphia globin genes among U.S. black and Italian Caucasian heterozygotes.

Seven Hb G-Philadelphia (Hb G) heterozygotes from three Caucasian families from Northern Italy and Sardegna were found to have proportions of Hb G averaging 23%. This value is considerably lower than the 34% or 48% found in Blacks from the Southeastern U.S.A. in whom the alpha G gene is in linkage with alpha-thalassemia-2, i.e. the alpha o alpha G/alpha alpha or alpha o alpha G/alpha o alpha genotypes. Gene mapping identified tandem organization of the alpha G gene in cis with a normal alpha A gene, i.e. the alpha alpha G/alpha alpha genotype, among the Hb G heterozygotes from Italy. The data on the Italian heterozygotes are similar to those obtained by Bruzdzinski et al (14) on a Black family. These results indicate alternate organization of the alpha G genes probably across racial or ethnic boundaries. Comparison of the mean cellular globin amount of alpha G/alpha G gene/cell among Hb G heterozygotes with 4, 3, 2 or 1 alpha globin genes (i.e. alpha A + alpha G) revealed considerable reactivation of individual alpha genes in conditions of mild to severe alpha globin deficiencies.

Adolescent↗

[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↗

Hb Belfast (beta 15 Trp replaced by Arg) in an Italian family.

An uncommon abnormal hemoglobin, Hb Belfast (beta 15 Trp replaced by Arg) was discovered in a patient of Italian origin. The patient was a 42-year-old man who developed two episodes of jaundice after a prolonged administration of an antituberculous drugs. Family studies revealed that several members were asymptomatic carriers of Hb Belfast.

Adult↗

[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↗

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↗

[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↗