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Biomedical subjects

K A Fleming

Publications and source records attributed to K A Fleming.

126 records · Page 7Linked to original sources
PubMed1985

Sensitive system for visualising biotinylated DNA probes hybridised in situ: rapid sex determination of intact cells.

A fast and sensitive method for detecting biotinylated deoxyribonucleic acid (DNA) probes was used for sex determination of cells and tissues by in situ hybridisation of a probe "specific" for the Y chromosome (pHY 2.1). Within 24 hours this procedure visualizes the Y chromosome in fetal and adult cells and tissue, without background noise. This procedure should facilitate antenatal determination of sex on small numbers of uncultured cells. The sensitivity of the procedure also permits the chromosomal assignment of genes present in low copy number.

Adult↗
PubMed1984

Langerhans' cells and T cells in human skin tumours: an immunohistological study.

In this study normal skin and a range of skin tumours, both benign and malignant, have been examined using monoclonal antibodies to identify the distribution and morphology of Langerhans' cells and T cells, the distribution of T lymphocytes and their subsets have been analysed using monoclonal anti-T cell antibodies. The results indicated that Langerhans' cells can be reliably identified in both normal and malignant skin biopsies using monoclonal antibodies. A striking finding to emerge was that in benign skin lesions Langerhans' cells were increased, whereas in malignant tumours they were not only markedly depleted or absent but also grossly stunted and deformed in outline. The majority of lymphocytes surrounding these skin tumours were shown to be T cells with helper cells outnumbering suppressor cells by a ratio from 2 to 5:1. This study shows the usefulness of immunohistological techniques using monoclonal antibodies for examining the morphology and distribution of Langerhans' cells in skin pathology. In addition they are particularly appropriate for identifying their topographical relationships with other immunologically important cells such as T cells.

Basal Cell Carcinoma↗
PubMed1984

Alcohol induced liver disease.

Alcohol induces a variety of changes in the liver: fatty change, hepatitis, fibrosis, and cirrhosis. The histopathological appearances of these conditions are discussed, with special attention to differential diagnosis. Many forms of alcoholic liver disease are associated with Mallory body formation and fibrosis. Mallory bodies are formed, at least in part, from intermediate filaments. Associated changes in intermediate filament organisation in alcoholic liver disease also occur. Their significance in the pathogenesis of hepatocyte death may be related to abnormalities in messenger RNA function. The mechanisms underlying hepatic fibrogenesis are also discussed.

Adult↗
PubMed1983

Cloning of total mRNA populations from adult and embryonic mice.

Total clone banks of cDNAs synthesized from poly(A)-RNA obtained from three stages of the developing mouse were constructed. The stages chosen were 13-day-old embryo, neonatal, and fully grown adult. To have as complete a bank as possible, large numbers of individual clones were generated approximately 400,000 for the 13th day embryo and neonatal mouse and approximately 610,000 for the adult bank. In each case the clone bank was constructed by inserting double stranded cDNA into the PstI site of pBR322 by the "G-C tailing" method. Sequences cloned in this way could be separated from the plasmid host DNA by treatment of the resultant total chimeric plasmid population with PstI. Aliquots of the cloned cDNA material were labeled with 32P by "nick translation" using Escherichia coli DNA polymerase I for the preparation of hybridization probes. Back-hybridization of these probes to the total clone banks allowed the determination of the sequence diversity among the above three very different developmental stages. The use of such clone banks should allow the identification of developmental stage specific mRNAs.

Age Factors↗
PubMed1983

An assay for C1q biosynthesis in cultured human fibroblasts.

With a standard C1 haemolytic assay, cultured human fibroblasts were shown to synthesize and secrete haemolytically active C1 and C1q. An assay for detection and quantitation of intra-cellular biosynthesis and secretion of C1q was then developed, using Sepharose beads covalently coated with goat monospecific anti-C1q IgG. The molecular structure of fibroblast C1q was found to be unusual in 2 ways: firstly, it probably represented an enlarged pro-C1q, and secondly, the secreted molecule had a different structure from the cell associated molecule.

Binding, Competitive↗
PubMed1982

The relationship between collagen and C1q biosynthesis in cultured human fibroblasts.

The relationship between collagen and C1q biosynthesis has been investigated in cultured human fibroblasts. This was done by measuring the effects of variation in cell density, inhibition of prolyl hydroxylase and complexing of C1q on synthesis and/or secretion of both proteins. It was found that synthesis and secretion of both proteins were not co-ordinate, and that therefore regulation of expression of both proteins is probably not linked. However complexing of C1q did result in marked stimulation in collagen synthesis, suggesting that the fibrosis which follows inflammation may result from binding of C1q to the immune complexes formed in the inflammatory process.

2,2'-Dipyridyl↗
PubMed1981

Mallory bodies in alcoholic liver disease: identification of cytoplasmic filament/cell membrane and unique antigenic determinants by monoclonal antibodies.

Polyclonal and monoclonal antibodies have been produced to Mallory body protein (MBP) extracted from isolated Mallory bodies (MBs). The polyclonal antibodies reveal a unique determinant in MBs. The first monoclonal antibody (anti-JMB1) detects a second unique determinant (JMB1) in MBs which is not detectable in normal hepatocytes. The second monoclonal antibody (anti-JMB2) shows that MBs contain another determinant which is associated with the cell and nuclear membranes and a cytoplasmic filament system of normal hepatocytes and bile duct epithelium; this antigen is not detectable in the cell membranes or cytoplasmic filament systems of hepatocytes which contain MBs. The third monoclonal antibody (anti-JMB3) reacts only with an antigen (JMB3) in mesenchymal cells of alcoholic cirrhotic liver and its significance, at this time, is unclear. It is suggested that the metabolism of JMB1, JMB2, and JMB3 antigens is deranged in hepatocytes damaged by alcohol. It is concluded that the antigenic structure of MBs is more complex than hitherto realised and that all of these antigens are distinct from prekeratin (a component of epidermal cell intermediate filaments).

Cell Membrane↗
PubMed1981

Immunohistochemical analysis of HLA (A, B, C) antigens in liver disease using a monoclonal antibody.

The distribution of HLA class I antigens was studied in 42 liver biopsies and eight necropsies by an immunoperoxidase technique employing a monoclonal antibody which reacts with the heavy chains of class I (A, B, C) HLA antigens. In normal liver HLA class I antigens could not be detected on hepatocyte cell membranes or cytoplasm; these antigens were present on the cell membrane of bile duct epithelium, on sinusoidal lining cells, fibroblasts, and blood vessel endothelium. However, in all patients with acute alcoholic hepatitis, most cases of primary biliary cirrhosis and some cases of chronic active hepatitis HLA class I antigens were detectable focally or diffusely on the cell membrane of hepatocytes; in two cases of acute viral hepatitis (non-A, non-B) HLA class I antigens were present in granular form in the cytoplasm of all hepatocytes. These findings may be relevant to the prolonged survival of liver allografts in man and other species and in the pathogenesis of some liver diseases.

Antibodies, Monoclonal↗
PubMed1981

Mallory bodies in alcoholic and non-alcoholic liver disease contain a common antigenic determinant.

An immunohistochemical technique is described for the detection of Mallory bodies (MBs) in paraffin sections of liver tissue. This is based on proteolytic digestion of sections before exposure to an antiserum which recognises a unique antigenic determinant in MBs. With the use of this procedure it has been shown in alcoholic liver disease, primary biliary cirrhosis. Indian childhood cirrhosis, Wilson's disease, diabetes mellitus, and hepatocellular cancer that the MBs found in these disorders contain this unique antigenic determinant. It is postulated, therefore, that the mechanism of formation of MBs is similar in liver diseases of diverse aetiology. In addition, it has been demonstrated that the immunohistochemical procedure is more sensitive than routine staining; MBs were detected in five out of 12 fatty livers by immunohistochemical and only in one by H and E staining. As MBs in fatty livers were not associated with polymorph filtration or fibrogenesis it is argued that MB formation is not an absolute prerequisite for the progression of acute to chronic liver disease.

Endoplasmic Reticulum↗
PubMed1981

Distribution of HLA class 1 antigens in normal human tissue and in mammary cancer.

With a monoclonal antibody which reacts with all HLA class 1 antigens it was found that these antigens are not uniformly distributed in all nucleated cells. Rather HLA class 1 antigens are restricted in their distribution to lymphoid cells, endothelial cells of small vessels, and certain epithelia including mammary duct cells. These antigens were not detected on hepatocytes, specialised cells of the central nervous system, or on the tumour cells of 8 out of 17 human mammary cancers. Given the hypothesis that T cells only respond to foreign antigens on cells which share a common major histocompatibility antigen, these results imply that the T cell responses to viral infections of hepatocytes--for example, hepatitis B virus and the CNS--for example, subacute sclerosing encephalitis, are mediated through an antigen system other than HLA class 1. The absence of HLA class 1 antigen on many mammary cancer cells may be of prognostic significance if T cell modulation of tumour growth is mediated through this class of antigens.

Adolescent↗
PubMed1980

Mallory bodies--immunohistochemical detection by antisera to unique non-prekeratin components.

Mallory bodies (MBs) were prepared in 95% pure form from a case of human chronic alcoholic liver disease. A protein referred to as Mallory body protein (MBP), was isolated from MB by reduction and alkylation which gave one band an SDS-polyacrylamide electrophoresis. Antisera were raised to both purified MBs and MBP in rabbits and a goat. Both antisera, after absorption with spleen cells, specifically reacted immunohistochemically with MBs in frozen sections from patients with alcoholic liver disease. They also reacted with small granular structures in hepatocytes which are interpreted as a precursor or degradation product of MBs. The anti-MB serum also stained MBs in trypsinised paraffin sections in the immunoperoxidase procedure. Neither antisera reacted with normal liver or skin, and the reactivity of anti-MB and MBP sera for MBs was not abolished by absorption with prekeratin; these results indicate that MBs contain unique antigenic determinants not present in prekeratin. It is concluded that MBs are not simply composed of intermediate filament proteins.

Cytoskeleton↗
PubMed1975

A case of 'Crohn's carcinoma'.

A case of adenocarcinoma of the ileum, occurring in an area concomitantly the site of Crohn's disease, is described. Examination of the literature suggests that there are certain characteristics of the small bowel carcinoma which arises in Crohn's disease. These include invisibility of the tumour on macroscopic inspection, dysplasia in the surrounding mucosa, and a peculiar endometriosis-like pattern of invasion. The finding that these tumours have certain characteristics is taken as evidence that carcinoma is a complication of Crohn's disease of the small bowel.

Adenocarcinoma↗
PubMed1975

Circadian rhythmicity of human plasma cortisol and PHA-induced lymphocyte transformation.

In two experiments, lymphocytes from six healthy subjects were sampled every 4 hr, counted, and cultured with PHA. Plasma cortisol in the same blood samples was measured and showed an expected circadian variation in level. A circadian rhythm in lymphocyte transformability to PHA was found to coincide directly with the cortisol level but varied inversely with lymphocyte numbers. The relationship between cortisol and lymphocyte transformability could be fortuitous or might indicate a role for cortisol in controlling lymphocyte function in vivo.

Adult↗
PubMedDate not supplied

Central presbyacusis: a longitudinal case study.

An elderly patient with presbyacusis was tested on four occasions over a 9-year interval. Although there was little change in peripheral hearing sensitivity, central auditory function declined substantially. Diminished success as a hearing aid user seemed to parallel the change in central function. Results suggest that the central changes were auditory-specific rather than generalized cognitive in origin.

Aged↗