Search PubMed⌕ Search

Biomedical subjects

A Roseto

Publications and source records attributed to A Roseto.

61 records · Page 4Linked to original sources
PubMedDate not supplied

Characterization of normal breast epithelial cells in primary cultures: differentiation and growth factor receptors studies.

The growth and differentiation of normal human mammary epithelial cells (HMEC) were studied after propagation of serial cultures from breast tissue biopsies from 42 mammoplasty patients. Cells were grown for up to 7 mo. in low calcium medium. HMEC cultures displayed heterogeneous growth patterns, according to the average doubling time of 44 +/- 6 h for 32 generations. Proliferation peaked at Day 30. HMEC maintained a normal karyotype and were organized in ductlike structures when cultured in collagen gel matrix. The cultures retained several phenotype traits of the epithelial lineage, including the expression of cytokeratins 18 and 19, specific mammary gland antigens, as shown by indirect HMEC immunostaining by the monoclonal antibodies DF3, EMA, 7B10, and 1BE12. Estrogen receptors were undetectable, whereas progesterone receptors were present at very low density. High-affinity cell surface receptors for epidermal growth factor (EGF) (Kd = 1.1 x 10(-10) M) were observed at a density of 50,000 to 100,000 sites per cell. Accordingly, [3H]thymidine incorporation in HMEC was optimally stimulated by EGF at concentrations of 10(-11) to 10(-10) M. HMEC were also seen to possess functional VIP receptors linked to the adenylate cyclase system, as we previously observed in seven human breast cancer cell lines. These results show that long-term cultures of HMEC provide useful models for studying the growth and differentiation of the normal human mammary gland, and the role of growth factors and hormones in these functions.

Adolescent↗
PubMedDate not supplied

Abzyme generation using an anti-idiotypic antibody as the "internal image" of an enzyme active site.

Since the two reports published in 1986 by the laboratories of R. Lerner and P. G. Schultz, it has been clearly established that antibodies may be induced to act as catalysts in numerous chemical reactions. In all cases, catalytic antibodies were elicited using a substrate-based approach. In the present article, we propose an alternative and complementary enzyme-based approach to generate catalytic antibodies. This approach uses the properties of anti-idiotypic antibodies to generate internal images of enzyme active sites. Experimental results are discussed for polyclonal and monoclonal anti-idiotypic antibodies.

Acetylcholinesterase↗
PubMedDate not supplied

Monoclonal antibody 83D4 immunoreactivity in human tissues: cellular distribution and microcytophotometric analysis of immunoprecipitates on tissue sections.

Immunocytochemical assays were performed on cell cultures as well as on a wide range of human tissues using a monoclonal antibody, MAb 83D4, produced by a murine hybridoma generated by immunization with a cell suspension from a paraffin block of human breast carcinoma tissue. Frozen breast tissue samples (n = 49) were compared to fixed and paraffin-embedded samples (n = 62). Paraffin sections (n = 194) from a variety of human tissues were compared to breast immunoreactivity. Immunoprecipitates, resulting from positive reactions between 83D4 and Avidin Biotin Peroxidase, were evaluated by computer-assisted microcytophotometry (SAMBA). In some frozen breast samples (n = 27), 83D4 antigen distribution was correlated with tumor cell DNA index, ploidy balance, growth fraction (Ki67), hormone receptor (ER, PR) antigenic sites, NORsAg and oncoprotein pHER-2/neu cell content. MAb 83D4 reacted with 3 breast cancer cells lines (MCF7, T47D and H466B) but not with normal epithelial breast cells in culture. The immunostaining in frozen paraffin sections from breast were similar. Like most normal tissues, normal breast did not react with 83D4. Cellular MAb 83D4 antigen concentration increases with the degree of malignancy but is independent of DNA nuclear content, ER, PR, growth fraction and pHER-2neu in cancers. These results suggested that routine immunohistochemical procedures using MAb 83D4 could facilitate the grading of breast cancer, in particular by allowing detection of microvascular invasions in the breast as well as at a distance and of blood-born micrometastases, especially in bone marrow.

Antibodies, Monoclonal↗
PubMedDate not supplied

Detection of rare human breast cancer cells. Comparison of an immunomagnetic separation method with immunocytochemistry and RT-PCR.

BACKGROUND: The detection of occult carcinoma cells in patients with breast cancer may aid determination of prognosis and the development of new therapeutic approaches. In this study, we report a new method to detect rare human breast cancer cells, which combines an immunomagnetic separation (IMS) procedure with cytokeratin 19 (CK 19) immunostaining. MATERIALS AND METHODS: Four monoclonal antibodies (MAb) previously characterized against cell surface antigens (1BE12, ED8, 7B10 and 83D4), were evaluated for IMS optimization. Immunoseparated epithelial cells were identified using a MAb against CK 19. We compared the IMS procedure with the immunocytochemistry (ICC) and the RT-PCR for CK 19 on an "in vitro" experimental model. RESULTS: The best results in IMS procedures were obtained using MAbs 1BE12 (directed against Lewis y antigen) and ED8 (directed against MUC 1). In reconstitution experiments, using several ratios of T47D cells mixed with peripheral-blood mononuclear (PBMN) cells, the IMS procedure reliably detects one mammary carcinoma cell in 5 x 10(5) PBMN cells, whereas the ICC detects up to one T47D cell per 10(5) PBMN cells. The best sensitivity was observed with the RT-PCR (up to one T47D cell per 10(6) PBMN cells). We found the same high specificity with the three methods evaluated. CONCLUSIONS: The IMS procedure using MAbs 1BE12 or ED8 associated with CK 19 immunostaining is a specific, sensitive, and feasible method for the detection of rare human breast cancer cells. This method proved to be better than the ICC staining but its sensitivity was lower than that of RT-PCR for CK 19.

Antibodies, Monoclonal↗