Search PubMed⌕ Search

Biomedical subjects

J Southgate

Publications and source records attributed to J Southgate.

At least 91 records · Page 5Linked to original sources
PubMed1986

A protein of squamous keratinising epithelium from odontogenic keratocyst fluid.

Fluid from odontogenic keratocysts was analysed. The major protein fraction with a mobility anodal to albumin on electrophoresis was shown not to be albumin or pre-albumin but a non-serum protein. Using an antiserum to keratocyst fluid absorbed with human serum, non-serum components of the odontogenic keratocyst fluid were localised in squamous keratinising epithelia, principally in the upper layers. The same antiserum showed immuno-localisation in squamous cell carcinoma of skin and cervix. No localisation was seen in normal non-squamous epithelia, in liver, stomach and colon or in non-keratinising squamous epithelial cysts of the jaw.

Body Fluids↗
PubMed1986

Phenotypic analysis of cultured melanoma cells. Expression of cytokeratin-type intermediate filaments by the M5 human melanoma cell line.

Expression of intermediate filament (IF) isotypes was studied in six human and two murine melanoma cell lines. With one exception, these lines expressed IFs only of the vimentin type; neurofilament peptides, desmin and GFAP were not detected. However, the M5 human melanoma line also expressed extensive cytokeratin tonofilament arrays, as visualized by immunofluorescence with a panel of eleven monoclonal antibodies and hetero-antisera to cytokeratins; only the keratin 19-specific antibody BA16 did not react. By 2 D gel electrophoresis, five major keratin peptides were detected (keratins 7, 8, 13, 17 and 18), and an additional 57 kD peptide was detected on immunoblots with several antikeratin antibodies. Also observed in M5 cells was focal collapse of tonofilament arrays in mitotic cells. All the melanoma lines tested were positive for S100; M5 and two other cell lines were also positive for the 220-240 kD neuroectoderm-associated cell-surface differentiation antigen defined by monoclonal antibody UJ 127:11. In all the melanoma cell lines, secretion of extracellular matrix proteins (fibronectin, laminin and collagen type IV) was sparse or absent, and all were negative for the epithelial cell markers HMG-1 and HMG-2. Co-expression of keratin and vimentin by a melanoma cell line is discussed in the light of recent controversy concerning expression of cytokeratins by other neoplasms of putative neuroectodermal origins.

Antibodies, Monoclonal↗
PubMed1985

Growth factor production during multistage transformation of epithelium in vitro. I. Partial purification and characterisation of the factor(s) from a fully transformed epithelial cell line.

Transforming growth factor (TGF)-like activity is characterised from one of a series of salivary epithelial cell lines, CSG 211, chemically transformed in vitro. In this transformation system, we can demonstrate multiple stages in the acquisition of a malignant phenotype by normal diploid ductal epithelial cells from male mouse submandibular gland. The fully transformed, tumorigenic cell TGF-like activity in serum-free supernatants resembles no other well-characterised growth factor and has an apparent molecular weight (Mr) of 14 kd. There is also evidence of a higher Mr activity, which is separable by anion exchange chromatography. We show that the premalignant, nontumorigenic progenitor cells of this line do not produce demonstrable TGF-like activity and that this property is therefore acquired as CSG 211 cells become carcinoma producing.

Animals↗
PubMed1985

Antibodies to normal human colon membranes: preparation, characterization and tissue distribution.

Rabbit antisera were raised to a membrane fraction of normal human colonic epithelium. After absorption, two antisera appeared to show restricted epithelial specificity when tested on routine paraffin wax-embedded histological sections by the indirect immunoperoxidase technique. The reaction was intense on epithelial cells of large and small intestine, and positive on stomach and duodenum, bile ducts in liver, gall bladder, pancreas and salivary gland. A very weak reaction was also seen in the bronchus and lung. There was no reaction with stromal, vascular or muscle components. All other tissues tested were negative, including hepatocytes, ectodermally-derived glandular epithelia, urogenital tissues and lymphoid organs. The antigen was also detected in 21 primary and metastatic large bowel carcinomata. By immunofluorescence, the antisera reacted with the colon adenocarcinoma-derived HT29 cell line and with primary colon epithelium explant cultures, but not with cultured fibroblasts. By immunoblotting of HT29 whole cell lysates, a triplet of polypeptides of approximate molecular weight range 55 000 to 60 000 were detected. This specificity appeared to be unrelated to previously described normal or tumour-associated antigens by criteria of tissue distribution, immunolocalization, molecular weight, and either absorption or radiobinding assays, or both.

Antibodies↗
PubMed1985

Micro-heterogenous expression of peanut agglutinin-binding sites in the extracellular matrix of cultured cells.

Using double-label techniques with fluorochrome-conjugated peanut agglutinin (PNA) and indirect immunofluorescence with rabbit species-specific anti-fibronectin antibodies and a mouse monoclonal anti-fibronectin, the extracellular matrix (ECM) of cultured human and mouse fibroblasts (Hell7 and 3T3K) and human bladder epithelial cells (T24) was studied. The antibodies and PNA co-localized extensively. However, a small but consistent degree of micro-heterogeneity was revealed insofar as both PNA-positive fibronectin-negative fibrils as well as PNA-negative fibronectin-positive fibrils were observed. Fibronectin production by T24 cells (but not fibroblasts) was influenced by the growth medium, but this did not affect the heterogeneity. Trypsin removed most cell-surface fibronectin and all PNA-binding sites, but did not account for the observed phenomenon. Intracellular fibronectin, whether present naturally or induced to accumulate by culture in presence of Monensin, was PNA-negative. These data suggest that PNA-binding sites appear on fibronectin as a consequence of incorporation into the extracellular matrix, and that the resultant heterogeneity of spatial expression of beta-galactose-like residues may offer a mechanism whereby mesenchymal cells could modulate the behaviour of overlying cell-types.

Animals↗
PubMed1985

Monoclonal antibodies to human urothelial cell lines and hybrids: production and characterization.

Eleven independent monoclonal antibodies, the LBS series, were isolated after immunization of mice with RT112 cells, a continuous cell line derived from a transitional cell carcinoma of the human bladder. These antibodies were tested by indirect immunofluorescence on a panel of 28 human cell lines, of which 17 were urothelial carcinoma-derived, 4 of non-urothelial carcinoma origin, 3 fibroblast cell lines, 4 lymphoblastoid lines and 7 murine cell lines. Also tested were 7 somatic cell hybrid clones derived by fusion of human RT112 cells with murine bladder carcinoma MB63T/H cells. None of the LBS antibodies reacted with mesenchyme-derived cells, although all reacted with RT112 cells. On the basis of reactivity with the cell line panel, the antibodies were divided into 3 groups. Group I (LBS-1 and 19) reacted with all human epithelium-derived cell lines. Group II (LBS-2, 8, 15 and 17) reacted only with human urothelium-derived cells, tending to recognise the least anaplastic types. Group III antibodies (LBS-10, 20A, 20B, 21 and 34) were urothelium-specific on the human continuous cell line panel, but additionally reacted with murine urothelial and epithelial cell lines. The 6 human-specific antibodies (Group I and II) were used for preliminary analysis of human gene expression in a series of 7 mouse X human urothelial somatic cell hybrids. Each hybrid reacted with at least 1 LBS antibody, although there were changes in gene expression with time in culture, indicating both loss and unmasking of human genes. These data suggest the LBS-series antibodies recognise different determinants associated with epithelial and urothelial cell differentiation, and thus may be valuable probes in the study of normal differentiation and malignant transformation in human urothelial cells.

Animals↗
PubMed1985

Changes in surface structure and concanavalin A-binding capacity of urothelium in the mouse bladder after whole-body neutron irradiation.

A broad overview has been compiled of the literature on the effects of radiation on urinary bladder and on selected cell surface markers that may give information on the pathobiological status of the urinary bladder urothelium. Scanning electron microscopy and immunogold labelling have been used in this study which examines the early (6h to 12 day) radiation response of the mouse urinary bladder following whole-body neutron irradiation. Experimentally, after 5 Gy neutron irradiation, changes in the urothelium include surface morphological abnormalities and enhanced concanavalin A surface binding. These changes were most obvious 1 to 5 days post-irradiation, but lessened in their extent from 5 to 12 days after treatment.

Animals↗
PubMed1976

Platelet mono-amine oxidase activity in the human fetus.

Measurement of the platelet mono-amine oxidase (MAO) activity in the human fetus of 40 weeks gestation showed it to be equivalent to that found in the adult. The level represents a fully-developed mitochondrial MAO system in platelets and may reflect enzyme maturity in other tissues of the newborn.

Blood Platelets↗