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Biomedical subjects

G Della Porta

Publications and source records attributed to G Della Porta.

At least 127 records · Page 7Linked to original sources
PubMed1971

Immunodepression during urethane and N-nitrosomethylurea leukaemogenesis in mice.

Five injections of urethane, 1 mg./g. body weight to suckling mice markedly reduced the primary immune response against sheep red blood cells assessed by splenic plaque forming cells (PFC) determination and haemagglutinin (HA) titration. The immunological impairment lasted for about 50 days after the end of the treatment. The secondary response tested by HA titration was not affected. A lower dose of urethane (0.5 mg./g.) produced only a delay of the primary HA response. A single neonatal dose of N-nitrosomethylurea (NMU) caused a profound immunodepression evaluated as HA titre and number of PFC. Both primary and secondary responses were still depressed when tested at 50 and 90 days of age respectively. No clear correlation between the degree of immunodepression and lymphoma development was found.

Animals↗
PubMedDate not supplied

Expression of differentiation and adhesion molecules in sporadic Burkitt's lymphoma.

The phenotypic features of 44 cases of sporadic Burkitt's lymphoma (BL) were investigated by monoclonal antibodies (MoAbs). The majority of cases were positive for HLA-DR (97 per cent), CD19 (100 per cent), CD20 (92 per cent) and CD37 (83 per cent) pan-B markers, in accordance with the B-cell derivation of the tumour; the B-cell restricted markers CD21, CD22 and FMC7 reacted with 28 per cent, 66 per cent and 75 per cent of cases, respectively. Of the mantle zone B-cell specific MoAbs, CD1c was always negative, whereas CD23 and 2.7 were positive with one and two cases, respectively. CD39 was weakly reactive on two specimens, one of which was CD23+. The germinal centre specific MoAbs CD10 and CD77 (Burkitt's lymphoma antigen) displayed a heterogeneous pattern of reactivity and allowed to identify 4 subgroups: CD10+/CD77+ (44 per cent), CD10+/CD77- (15 per cent), CD10-/CD77+ (36 per cent) and CD10-/CD77- (5 per cent). Of 15 cases tested for the expression of CD11a and CD18 lymphocyte-function-associated (LFA-1) antigens and their ligand ICAM-1 (CD54), seven were positive and six negative for the three markers, while the other two cases expressed alternatively the two molecules. Analysis of the putative normal BL cell counterpart, identified with the CD77 marker in normal lymphoid tissues, showed that all CD77+ B-cells were constitutively CD11a+/CD18+, suggesting that BLs are likely to arise from a LFA-1 positive B-cell and may down-regulate these molecules during neoplastic transformation.

Adolescent↗
PubMedDate not supplied

Cellular and molecular biology of melanoma.

Melanoma cells have surface markers that are expressed differently than in normal melanocytes and nevus cells. Monoclonal antibodies may define a phenotypic map of the various melanocytic lesions and can be used in immunohistopathology and immunoscintigraphy. Monoclonal antibodies directed against melanoma-associated glycoproteins and glycolipids are being tested for therapy. Rearrangements or deletions on chromosome 1, 6, and 7 are the most frequently observed cytogenetic abnormalities. Molecular studies have not given a clear picture. A subset of HRAS alleles has been reported to be associated with melanoma. NRAS activation by point mutation has been found in one fourth of the cases. Allele losses at different loci have been reported. Genetic linkage studies have given conflicting results on the presence of a gene for the melanoma-dysplastic nevus syndrome on the short arm of chromosome 1.

Antigens, Neoplasm↗
PubMedDate not supplied

The undefined relationship between tumor antigens and histocompatibility antigens on cancer cells.

The data pertaining to the possible relationship between histocompatibility antigens (HA) and tumor-specific transplantation or tumor surface antigen (TSTA or TSA) are reviewed. The HA profiles of certain experimental and human neoplasms have been found to be altered either from the quantitative (increased expression of some antigenic specificities and decreased expression or even lack of other HA) or qualitative point of view (appearance of alien, genetically inappropriate HA). The authors entertain the possibility that the persence of TSTA or TSA on cancer cells may be linked to alterations of the HA profile. Evidence in favour of the idea that tumor antigens may actually to alien MHC products, alien minor HA or modified HA, is reviewed. Findings on structural relationships between TSA and beta2-microglobulin are also summarized. In the authors' opinion, no definitive conclusions can be reached at the present time on the relationship between TSTA or TSA and HA of cancer cells.

Animals↗