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Biomedical subjects

P Jackson

Publications and source records attributed to P Jackson.

At least 217 records · Page 12Linked to original sources
PubMed1985

Practical applications of a monoclonal antibody (NDOG2) against placental alkaline phosphatase in ovarian cancer.

A monoclonal antibody (NDOG2) against placental alkaline phosphatase (PLAP) in ovarian cancer has been used in three ways by the Bristol University Department of Obstetrics & Gynaecology. First, in an indirect immunoperoxidase technique, NDOG2 demonstrated positive standing in 64% of 56 ovarian carcinomas as well as in 25% of 44 benign tumours. The majority of these positive tumours were serous cystadenocarcinomas or serous cystadenomas and there was considerable variation in the expression of this antigen from tumour to tumour. NDOG2 was also used as the basis of two serum assays and, when labelled with 123-iodine (123I), in radioimmunoscintigraphy (RIS) to monitor patients' response to therapy. The first serum assay measures the enzymic activity of PLAP and the second recognizes the antigenicity of the molecules. Assay 2 proved more useful in that it predicted the course of the disease in 45% of patients followed up, whereas Assay 1 was only of use in 25% of cases. RIS proved to be a useful imaging technique and was at least as sensitive as conventional imaging techniques. The common causes of false-positive and false-negative results are described.

Alkaline Phosphatase↗
PubMed1984

Metabolic study of variation in plasma cholesterol level in normal men.

Variation in plasma cholesterol in normal populations underlies a 2-5 fold range of risk of coronary heart disease. The metabolic basis of this variation was studied in a healthy population recruited from a general-practice list. Compared with men in the modal decile of plasma cholesterol, those in the top decile maintained their high levels by overproduction of low-density lipoprotein (LDL). Men in the bottom decile of plasma cholesterol had low levels of LDL, resulting chiefly from a greater rate of fractional catabolism of this lipoprotein; and blood mononuclear cells from men in the bottom decile catabolised LDL more rapidly in vitro than did cells from other men. Intake of dietary lipids by men in the top, modal, and bottom deciles did not differ significantly. Different mechanisms appear to underlie high and low levels of plasma cholesterol in a normal population.

Adult↗
PubMed1984

The existence and properties of two dimers of rat liver ecto-5'-nucleotidase.

Immunoaffinity-purified rat liver 5'-nucleotidase contained two subunits of Mr 70 000 (alpha) and 38 000 (beta). Charge-shift electrophoresis and chemical cross-linking revealed that approx. 80% of the solubilized enzyme activity occurred as an alpha alpha-dimer of Mr 140 000. The remaining 20% was an alpha beta-dimer of Mr 108 000. The beta-subunit did not possess enzymic activity. Peptide mapping and immunoblotting with antibodies against the alpha- and beta-subunits showed that the beta-subunit was homologous with a part of the alpha-subunit. Three monoclonal antibodies against rat liver 5'-nucleotidase were characterized as binding to the extracellular domain of the enzyme. All three monoclonal antibodies and concanavalin A bound to the alpha-subunit, but no binding could be detected to the beta-subunit. It was therefore concluded that the beta-subunit was a fragment of an alpha-subunit that had lost an extracellular domain. Both forms of the enzyme occurred in freshly solubilized membrane preparations as well.

5'-Nucleotidase↗
PubMed1984

An image processing system for digital chest X-ray images.

This paper investigates the requirements for image processing of digital chest X-ray images. These images are conventionally recorded on film and are characterised by large size, wide dynamic range and high resolution. X-ray detection systems are now becoming available for capturing these images directly in photoelectronic-digital form. In this report, the hardware and software facilities required for handling these images are described. These facilities include high resolution digital image displays, programmable video look up tables, image stores for image capture and processing and a full range of software tools for image manipulation. Examples are given of the application of digital image processing techniques to this class of image.

Computers↗
PubMed1984

A multifactorial diet in the management of hyperlipidaemia.

To augment the effectiveness of conventional lipid-lowering treatment, a diet has been evolved combining modified fat content with an increase in vegetable-derived fibre and protein. This was evaluated in 37 hyperlipidaemic and normal ambulant subjects in whom plasma lipid and lipoprotein responses were measured for 4.7-11 months. Mean reductions in plasma cholesterol, triglyceride and low density lipoprotein cholesterol levels were 22, 24 and 25% respectively; there was no significant change in the cholesterol concentrations in high density lipoprotein or in its HDL2 subclass. The effectiveness of the diet in reducing hyperlipidaemia, its influence in optimizing the distribution of cholesterol between plasma lipoprotein classes, and its nutrient composition suggest that it is an advance on existing lipid-lowering dietary patterns.

Adult↗
PubMed1984

Radionuclide evaluation of acute scrotal disease.

Technetium-99m sodium pertechnetate scintigraphy is an established method for evaluating organ perfusion and can be applied to the investigation of suspected testicular ischaemia due to acute torsion. One hundred and six consecutive scrotal investigations have been analysed qualitatively and quantitatively using a computer-based comparison of the perfusion slopes over each testis. Decreased vascularity on the symptomatic side only occurs in torsion and quantitative analysis is needed to detect it reliably. Increased vascularity on the symptomatic side can usually be detected qualitatively and occurs in orchitis, tumours, trauma and resolved torsion. Distinction between the causes of increased vascularity is aided by the clinical data. A halo of increased activity surrounding a relatively cold centre was seen in chronic torsion, some tumours and hydrocoeles. The test is both sensitive and specific for acute torsion but its usefulness is limited if it is not available at all hours. The test is useful, also, in confirming a diagnosis that does not require emergency operation and in identifying chronic torsion which is an indication for contralateral orchidopexy.

Acute Disease↗
PubMed1984

Fragments of myelin basic protein derived from human brain are not mitogenic in cultures of human amniotic fluid cells and other cells.

The possible mitogenic effects of a number of preparations of the myelin basic protein (MBP) of human brain have been investigated in various cell types in culture, including human amniotic fluid cells. Intact human MBP, as well as fragments derived by BNPS-skatole and cathepsin D treatment, and isoelectric focusing fractions of human MBP, showed no mitogenic activity. These results are consistent with recent findings that the fibroblast growth factor (FGF) activity of bovine brain does not originate from MBP.

Amniotic Fluid↗
PubMed1984

A study by high-resolution two-dimensional polyacrylamide gel electrophoresis of relationships between Neisseria gonorrhoeae and other bacteria.

High-resolution two-dimensional polyacrylamide gel electrophoresis was used to analyse the soluble proteins from seven strains of Neisseria gonorrhoeae, six strains of Neisseria meningitidis and one or two strains of twelve other species. Approximately 200 individual polypeptides could be visualized as Coomassie Blue stained spots on an electrophoretogram of N. gonorrhoeae and similar numbers were found for the other bacteria. Each species of bacterium had a distinctly different pattern of spots which could be recognized. Quantitative comparisons of 48 selected spots derived from one strain of N. gonorrhoeae with those of five other strains of gonococcus, three strains of N. meningitidis and one of Branhamella catarrhalis, showed relationships in agreement with their current taxonomic classification but with a higher level of discrimination than that of previously used methods. It was also possible to distinguish the individual gonococcal strains. It is suggested that the method could be useful for bacterial classification and identification.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Localisation of factor XIII in human tissues using an immunoperoxidase technique.

An immunoperoxidase technique has been used to localise clotting factor XIII subunits A and S in human tissues. The presence of factor XIII in placenta and megakaryocytes was confirmed. Factor XIII was also found in fibroblasts, a hitherto unreported finding. Factor XIII subunits were not detected in hepatocytes, although factor XIII was found in fibroblasts in portal tracts. These findings suggest that factor XIII is not synthesised in the liver as previously thought.

Animals↗
PubMed1983

PGP 9.5--a new marker for vertebrate neurons and neuroendocrine cells.

PGP 9.5 is a new cytoplasmic neuron-specific protein structurally and immunologically distinct from neuron-specific enolase. A specific antiserum has now shown that this protein is widely distributed in vertebrate brains and is also present in cells of the human diffuse neuroendocrine system. PGP 9.5 appears to be older than neuron-specific enolase in evolutionary terms, as an immunologically-related protein can be found in species as remote as the trout.

Animals↗