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D Buffe

Publications and source records attributed to D Buffe.

14 recordsLinked to original sources
PubMed1987

c-Ki-ras gene amplification and malignant behavior in murine embryonal carcinoma cell lines.

Embryonal carcinoma (EC) cells are malignant components of murine teratoma tumors. To extend our earlier findings concerning c-Ki-ras amplification in the embryonal carcinoma PCC4 cell line, we examined the c-Ki-ras protooncogene and its expression in other EC cell lines. We report here that c-Ki-ras amplification is not a general feature of EC cell lines since neither PCC3, PCC6, nor F9 cell lines have an amplified copy number of this protooncogene. Furthermore, molecular analysis of three independently passaged PCC4 cell lines showed marked heterogeneity for c-Ki-ras amplification. Two PCC4 cell lines showed amplified copy number and elevated expression of c-Ki-ras whereas the original one does not, suggesting that this gene amplification occurred through laboratory passage. Malignancy in syngeneic mice of PCC4 with or without an amplified c-Ki-ras gene was also examined. Our results indicate that c-Ki-ras amplification alone is not a determining factor in the malignant behavior of EC cells.

Animals↗
PubMed1975

[Molecular weight of human alpha2-H-ferroglobulin subunits. Comparison with molecular weight of ferritin subunits].

alpha2 H globulin, a glycoferroprotein, was first demonstrated in the sera of patients with malignant diseases. This protein was isolated from cancerous human liver, and compared with ferritin, a ferroprotein showing some identical properties (presence of iron, high molecular weight, common antigenic determinants). However, physicochemical differences were observed between these two proteins. The study of protein dissociation was performed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate after reduction by mercaptoethanol. A similar molecular weight of 19 000 is obtained for subunits of these two proteins. This value agrees well with the results obtained by other authors for ferritin.

Ferritins↗
PubMed1975

[Immunosuppressive effect of a human serum ferroprotein of hepatic origin, alpha 2 H globulin. Study on blastic transformation of normal lymphocytes in the presence of phytohemagglutinin].

The alpha2 H globulin, a glycoferroprotein, has been found in the serum of patients with malignant diseases. Its level varies according to the evolution of the disease. The activity of this protein has been studied on the normal lymphocytes cultivated in presence of phytohemagglutinin. This study has showed that 5 mug/ml of alpha2 H globulin can inhibit the blastic transformation. The inhibitory effect is proportional to the amount of alpha2 H globulin added as judged by the tritiated thymidin incorporation. The study of morphological aspects of the lymphocytes shows that alpha2 H globulin acts upon the synthesis of the cytoplasmic proteins.

Alpha-Globulins↗
PubMed1975

Immunosuppresive effect of a human hepatic glycoferroprotein, alpha2H globulin. A study on the transformation of normal human lymphocytes.

A macroglycoferroprotein of hepatic orgin, alpah2H globulin, the serum level of which increases a few weeks or months before local recurrence of metastases, has been essayed for its immunosuppressive activity. The study was carried out using the lymphoblastic transformation test and was judged by tritiated thymidine incorporation and microscopic examination. PHA-induced blast transformation of 97 per cent of normal donor lymphocytes is inhibited by 100 mug/ml of alpha2H globulin. This inhibitory effect is proportional to the quantity of added alpha2H globulin. In is obvious with a concentration of 2-5 mug/ml, a frequently observed level in the serum of patient with tumours. Preincubation of lymphocytes with alpha2H globulin renders more effective the inhibitory action on PHA-induced transformation. A mechanism of competition between PHA and alpha2H globulin is suggested by preincubation and the inhibitory effect related to the doses. However, microscopic observation shows that alpha2H globulin acts on the earliest events occurring to the stimulated lymphocytes, by inhibiting cytoplasmic RNA and protein synthesis. The alpha2H globulin effect may not only have an immunosuppresive activity but it may have a more general effect, for example blocking or modifying cellular respiration.

Alpha-Globulins↗
PubMedDate not supplied

[Immunological localization of alpha-fetoprotein in the proximal endoderm and its significance in extra-embryonic differentiation of teratocarcinomas in the mouse].

The ABC technique using a specific anti-mouse alpha-foetoprotein (AFP) serum permits identification of groups of extraembryonic proximal endoderm cells in certain teratocarcinomas. These AFP+ cells are always associated with trophoblastic and parietal endodermal patterns and structures. These observations strongly support the hypothesis of a common precursor to the extraembryonic tissues which appears during the first phases of egg development.

Animals↗
PubMedDate not supplied

[Immunohistochemical localization of chorionic gonadotropin and alpha fetoprotein in polyembryomas: description and interpretation].

As polyembryomas are special forms of human teratomas in which numerous structures mimicking the early stages of the human embryo are conspicuous, immunoperoxidase staining of these embryoid bodies (EB) has been used to reveal the initial appearance and localization of beta HCG and AFP, respectively, in amnion and in primary yolk-sac. EB are involved in the building of various questionable patterns of teratomatous germ-cell tumours. Special emphasis has been placed on tracking yolk-sac tumour patterns through dislocating EB, using a specific anti-human AFP serum.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Modification of the immune response by a hepatic ferroglobulin: L alpha2-HF].

Alpha2-HF, foetal and tumorous isoferritin, the level of which is high in cancerous patients and in amniotic fluid during pregnancy, has an immunosuppressif effect on normal lymphocytic response. Its activity has been tested on blastic transformation induced by PHA, tuberculin, candidin and allgenic lymphocytes. The inhibition effect is proportional to the added quantity of alpha2-HF globulin. The antibody synthesis is depressed by alpha2-HF as demonstrated in vivo and in vitro. Iron is no responsible for the suppressif effect: the efficiency is identical with the native protein or the apo-protein. Crystallised ferritin, without sugar in its molecule on the contrary of alpha2-HF which is a glycoferroprotein, has no suppressif effect.

Alpha-Globulins↗