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Biomedical subjects

G Della Porta

Publications and source records attributed to G Della Porta.

At least 109 records · Page 6Linked to original sources
PubMed1979

Antibody binding to membrane of cultured melanoma cells by sera of melanoma patients.

One hundred and nine sera from 75 patients with malignant melanoma and 69 sera from as many healthy donors were assayed by isotopic antiglobulin technique (IAT) on 2 melanoma cell lines. The same picture of reactivity was observed with patients' and healthy donors' sera, and in both groups 35% of the cases were high responders on 1 line and 21% on the other one. The specificity of the reactions was analyzed by absorption experiments using 12 melanoma sera selected for their high binding activity. Pools of human erythrocytes or leukocytes did not remove, except in 1 case respectively, the activity of the sera, suggesting that it was not directed against alloantigens. Quantitative absorption experiments were done with the 2 melanoma lines and with 1 colon carcinoma line. The results, evaluated on the basis of absorption capacity per cell, indicate that the 2 melanoma lines had a similar amount of shared antigens, whereas the colon line was also effective in absorbing out the serum activity, but less frequently and less efficiently. Further experiments performed to analyze the influence of culturing the target cells in presence of fetal bovine serum (FBS), showed that the activity of sera was removed, at various degrees for different sera, by absorption with free FBS, with FBS coupled to Sepharose 4B, and with normal leukocytes cultured overnight with 10% FBS. The same positive melanoma sera became negative when assayed on the same melanoma line cultured in gamma-globulin-depleted human AB serum. In conclusion, in our experimental conditions, the activity of melanoma sera seems mostly directed against components of FBS absorbed on cell membrane during culturing.

Adenocarcinoma↗
PubMed1976

Cellular immune reaction to human malignant melanoma and breast carcinoma cells.

An in vitro microassay was used to study cytotoxic reactivity of lymphocytes of 19 patients with malignant melanoma, 8 patients with breast carcinoma, and 18 normal subjects on cell cultures of malignant melanoma and breast carcinoma. In each of the twelve experiments, peripheral blood lymphocytes from individuals with and without cancer were tested simultaneously on two or three different target cells. Cytotoxic reactivity, evaluated by a comparison of the number of target cells remaining after incubation with lymphocytes with those incubated with medium only, was found in 20 cancer patients (74%) and 13 individuals without cancer (72%). The strength of lymphocyte reactivity of the cancer and of the non-cancer group did not differ significantly. Of the 27 cancer patients, 8 were positive only on the homologous target cells, 7 only on the opposite cells, and 5 on both types; 7 were negative. Short-term melanoma cell cultures were more lysable than were established cell lines; however, no direct correlation between the growth rate during the test period and susceptibility to lysis was seen. The blood group of the lymphocyte donors had no influence on cytotoxic reactivity.

ABO Blood-Group System↗
PubMed1975

Humoral cytotoxicity in melanoma patients and its correlation with the extent and course of the disease.

Complement-dependent cytotoxicity against melanoma cells was demonstrated with a microassay in sera from melanoma patients. The response was tumor-specific and histologic type-specific since 16 out of 52 (30%) melanoma patient sera taken before surgery reacted against melanoma cells, whereas 3 out of 43 (7%) control sera, collected from patients with unrelated tumors and from cancer-free individuals, were positive. The serum activity correlated with the clinical stage of the disease since it was detected in 15 out of 40 patients with stage I and II tumors and in 1 of the 12 patients in stage III. Twelve melanoma patients, clinically tumor-free for to 4 years after surgery, showed no humoral cytotoxicity. A follow-up study of 13 melanoma patients revealed that the cytotoxicity appeared 7-10 days after radical removal of the tumor and that it disappeared if there was no recurrence. The histologic type-specificity was further tested by assaying sera from 16 melanoma and 10 breast-cancer patients simultaneously on both melanoma and breast-cancer cells; a positive reaction was observed in 6 cases of melanoma and in 5 of breast cancer on homologous cells only, in 1 case on the opposite type of cells, and in 3 cases on both types of tumor cells.

Adolescent↗
PubMed1975

Genetic control of endogenous C-type virus production in pancreatic acinar cells of C57BL/He and C57BL/6J mice.

Electron microscopy revealed very active production of C-type virus particles in the pancreatic acinar cells of untreated normal adult mice of the C57BL/He strain. In C57BL/6J mice, a similar picture was observed after a single intraperitoneal injection of dexamethasone. No viruses were observed in the pancreas of untreated or dexamethasone-treated BALB/c and C3Hf mice. F1 hybrids of both C57BL strains with C3Hf mice produced viruses in the same manner and quantity as the C57BL parents, whereas hybrids with BALB/c mice were entirely negative. Approximately 50% of mice of the first backcross generation of (BALB/c times C57BL/He)F1 hybrids with C57BL/He mice were active producers of C-type particles, while the other 50% were negative. It is suggested that a regulator gene that controls C-type virus production does not function in the pancreatic cells of either C57BL strain, and that BALB/c mice can provide hybrids with an active regulator.

Animals↗
PubMed1974

Embryonic antigens and growth of murine fibrosarcomata.

The amount of embryonic antigens (EA) was estimated in 13 BALB/c fibrosarcomata by in vitro cell mediated cytotoxicity of anti-embryo spleen cells and by quantitative absorption of an anti-embryo antiserum. A direct relationship between amount of EA and tumour growing capacity was found. EA were detected also on fast dividing testicular cells. It is suggested that EA expression on tumour cells is related to a cell membrane function controlling mitosis rather than to a function specifically related to the neoplastic status. Tumour take of low doses of 2 EA-bearing sarcomata was found to be enhanced in anti-embryo immune BALB/c mice in comparison with that in normal and anti-fibroblast immune mice.

Animals↗