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L Bobrow

Publications and source records attributed to L Bobrow.

23 records · Page 2Linked to original sources
PubMed1991

Morphology and immunohistochemistry of carcinoma in situ adjacent to testicular germ cell tumours in adults and children: implications for histogenesis.

Observations differ on the pre-invasive malignant lesions associated with the various categories of testicular germ cell tumours. Such lesions have been found to be similar in appearance and are assumed to be composed of multipotent cells, or conversely a distinctive pre-invasive stage has been reported in association with each form of germ cell neoplasm. This study was undertaken to see whether distinctive morphological and immunohistochemical features of carcinoma in situ adjacent to various categories of germ cell tumours could be established. Carcinoma in situ adjacent to seminomas, teratomas and mixed germ cell tumours in 18 adults was indistinguishable morphologically. Placental alkaline phosphatase was demonstrated immunohistochemically but vimentin and low molecular weight cytokeratins were uniformly absent in these abnormal germ cells from all three groups. These findings support the concept of a multipotent pre-invasive malignant cell for both seminoma and teratoma in the adult. Carcinoma in situ was not seen adjacent to 15 spermatocytic seminomas, nor was placental alkaline phosphatase demonstrated in tubules adjacent to these tumours. These negative findings are additional evidence that spermatocytic seminoma differs from classical seminoma in its histogenesis. Carcinoma in situ, as defined morphologically and immunohistochemically in adults, was not identified adjacent to yolk sac tumours and differentiated teratomas in 20 prepubertal testes. The possibility that pre-invasive malignancy in children may not resemble that in adults must be considered when assessing the malignant potential of cryptorchid testes on biopsies taken during orchidopexy.

Adult↗
PubMed1991

Differential expression of antigens by human small cell lung carcinoma in sections of tumour and in serous effusions.

Antigen expression by human small cell lung carcinoma cells in serous effusions was determined by staining smears of cells with a panel of four monoclonal antibodies including UJ13A (cluster 1 antigen) and CAM 5.2 (anti-cytokeratin) using an immunoalkaline phosphatase technique. This was quantified by counting the proportion of stained and unstained tumour cells and was compared with that of small cell lung carcinoma in sections of solid tumour. Differential expression of antigen expression was noted with significantly fewer small cell carcinoma cells in serous effusions staining with UJ13A or CAM 5.2. The reasons for this differential expression are unknown, but may reflect adaptation to a different environment or be a prerequisite for spread to serous space.

Antigens, Neoplasm↗
PubMed1986

Characterization and chromosomal assignment of a human cell surface antigen defined by the monoclonal antibody AUAI.

We describe the chromosomal assignment and biochemical characterization of the genetic locus controlled by a human cell surface antigen which is defined by the monoclonal antibody (MAb) AUAI. This gene product is only expressed on epithelial cells. Therefore, human-mouse somatic cell hybrids of epithelial origin were used to assign this gene to chromosome 2. Cell surface iodination of the hybrids and parental cells followed by immunoprecipitation and polyacrylamide gel electrophoresis showed that AUAI detected a single 35-kDa protein. The MAb AUAI reacted on tissue sections with a subset of normal epithelial cells, but in tumours it showed a much wider distribution, though still only on epithelium-derived tumours.

Antibodies, Monoclonal↗
PubMed1986

Expression of epidermal growth factor receptors on human cervical, ovarian, and vulval carcinomas.

We describe the properties of two monoclonal antibodies produced to a synthetic peptide consisting of residues 985 to 996 from the cytoplasmic domain of the epidermal growth factor (EGF) receptor. We have examined a group of ten human tumors including cervical, ovarian, and vulval carcinomas for expression of EGF receptors by immunohistological staining using one of these antibodies and another monoclonal antibody to the extracellular domain of the molecule. The tumors were examined using a sensitive amplified enzyme system and a less sensitive indirect staining method. There was generally a good correlation in staining intensity with the two monoclonal antibody reagents. Both antibodies showed strong staining of squamous cell carcinomas and usually weak or heterogeneous patterns with the adenocarcinomas. Samples of each tumor were solubilized in detergent and analyzed for the presence of functional EGF receptors by immunoprecipitation and autophosphorylation. Three of the squamous cell tumors gave labeled bands, Mr 170,000, on sodium dodecyl sulfate:polyacrylamide gels. DNA was extracted from seven of the tumors and digested with two restriction endonucleases, and the fragments were analyzed on Southern blots using probes representing the extracellular and cytoplasmic domains of the molecule. The tumor DNA showed no apparent rearrangements or amplifications when compared to the EGF receptor gene in human placental DNA. These results suggest that there is a high level of EGF receptors on some squamous cell tumors.

Antibodies, Monoclonal↗