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J Aziza

Publications and source records attributed to J Aziza.

3 recordsLinked to original sources

Cell therapy of pain: Characterization of human fetal chromaffin cells at early adrenal medulla development.

Adult adrenal chromaffin cells are being utilized for therapeutic transplantation. With the prospect of using fetal chromaffin cells in pain therapy, we studied their phenotype, proliferative power, function, and growth in vitro and in situ in order to determine the optimal time for implantation. Between 7 and 10 gestational weeks (GW), we isolated, in vitro, two types of chromaffin cells with a noradrenergic phenotype akin to that observed, in situ. Among the adherent chromaffin cells first observed in vitro, only a few samples expressed met-enkephalin, whereas almost all the neurosphere-like colonies, which appeared later, expressed it. However, neither of the two types of populations expressed an adrenergic phenotype in line with that observed in situ. At the upper limits of the voluntary abortion period authorized in France, this phenotype (12 GW) and met-enkephalin expression (13 GW) were evidenced in situ. For the first time in man, we demonstrate the secretion of noradrenaline in vitro by the two populations of cells. Consistent with this result, we also noted dopamine beta hydroxylase (DbetaH) mRNA expression in vitro and in situ within this period. These observations on the expression of these biological factors indicate that 9-10 GW would be the best stage for sampling these cells for preclinical transplantation experiments.

Adrenal Medulla↗

Production and characterisation of an antimelanoma monoclonal antibody KBA.62 using a new melanoma cell line reactive on paraffin wax embedded sections.

AIMS--To generate new monoclonal antibodies directed against melanoma associated antigens using a new melanoma cell line, KAL. METHODS--The melanoma cell line was established in culture from a lymph node metastasis of malignant melanoma. Normal Balb/c mice were immunised with KAL cells. Splenocytes were used for fusion experiments using standard techniques. Hybridoma supernatants were tested for antibody binding activity using an indirect immunoperoxidase method on frozen sections from KAL tumour cells xenografted onto nude mice and human tonsils. KBA.62 was selected because of its reactivity with melanocytic proliferations on both frozen and paraffin wax sections. RESULTS--On immunoblotting, KBA.62 reacted with three bands of 140, 135 and 128 kD and two weak bands of 88 and 73 kD. In normal human tissues basal melanocytes in the epidermis did not react with this antibody and only occasional labelling of endothelial cells was noted. Of the human tumours, KBA.62 reacted strongly and uniformly with the majority of benign (21/21) and malignant (75/86) melanocytic proliferations. Staining was localised predominantly to the cell membrane with little or no cytoplasmic reactivity. Negative staining was observed in the majority of human non-melanocytic neoplasms, the exceptions being some carcinomas (11/89), particularly the well differentiated squamous cell type. This, however, was not thought to present a diagnostic problem. CONCLUSIONS--KBA.62 appears to be potentially useful in ascertaining the immunomorphological diagnosis of malignant melanoma in routinely processed paraffin wax sections.

Animals↗