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Biomedical subjects

S Bradbury

Publications and source records attributed to S Bradbury.

At least 19 recordsLinked to original sources
PubMed1984

Colloidal iron hydroxide staining of surface carbohydrates after glycerol treatment of uterine epithelial cells.

The structural relationships between intramembraneous particles (IMPs) and surface carbohydrates has been studied in uterine epithelial cells with a colloidal iron hydroxide (CIH) technique. To aggregate IMPs, glycerol treatment of unfixed cells was used and this treatment also caused some patching of CIH deposits on the cell surface. We conclude that some of the CIH receptors may be the surface expression of the IMPs.

Animals↗
PubMed1983

Commercial image analysers and the characterization of microscopical images.

This review surveys some of the current approaches to the characterization of microscopical images using commercially available image analysers. The role of image pre-processing and segmentation is considered, together with the characterization of images by optical density, as well as size and shape. The newer analysers are capable of investigating relationships between grey-levels in small areas of the image ('texture-analysis'); some of the descriptive approaches in this latter field are briefly outlined.

Animals↗
PubMed1981

Hepatocystis in Hypsignathus monstrosus (pteropinea) in Gaboon I. Hepatocystis malaria in a hammerhead bat population in Gaboon, West Africa.

Blood smears from 142 Hypsignathus monstrosus collected from one site in Gaboon were examined; 139 bats showed Hepatocystis infection; it seems that all animals have acquired Hepatocystis infection by the time they are 6 months of age. Intensity of parasitemias varies according to age, sex and for females to their reproductive status.

Age Factors↗
PubMed1980

Sleep apnoea in acromegaly.

Day time somnolence or excessive snoring, or both, occurred in five out of 11 patients with acromegaly. All five had episodes of sleep apnoea, and three had the sleep apnoea syndrome. Growth hormone concentrations were higher (p less than 0.025) in these patients than in the six patients without these symptoms. One patient with daytime somnolence and one asymptomatic patient had flow loop evidence of upper airways obstruction. Two of the patients with the sleep apnoea syndrome had cardiomegaly. Sleep apnoea appears to be common and clinically important in acromegaly, and it may be central, obstructive, or mixed. Polygraphic nocturnal monitoring is indicated to assess these patients properly.

Acromegaly↗
PubMed1980

Effect of lecithin on disability and plasma free-choline levels in Friedreich's ataxia.

Four patients with Friedreich's ataxia took part in an open trial, in which they consumed 50-100g/day lecithin granules (containing approximately 22% phosphatidycholine) for 16 weeks, but no improvement resulted. Several unwanted effects including diarrhoea, nausea, depression, "hot flushes" and weakness were experienced. Resting levels of free-choline in plasma were within the range found in 19 normal subjects. Sixteen other patients with Friedreich's ataxia also had normal free-choline levels. Treatment with lecithin significantly increased plasma free-choline levels, but there was a trend for these to fall towards baseline levels, despite continued ingestion of lecithin.

Adolescent↗
PubMed1980

Sleep apnoea in Scheie's syndrome.

An 18-year-old student presented with a two-year history of daytime sleepiness and noisy breathing during sleep. Both he and his brother, aged 25 years, had Scheie's syndrome, a mucopolysaccharidosis characterised by small stature, micrognathia, corneal clouding, hepatosplenomegaly, raised urinary mucopolysaccharides, and undetectable levels of alpha-L-iduronidase assayed in cultured fibroblasts. Both brothers had sleep apnoea (apnoea index, 59 and 35 respectively) during which there was a significant fall in heart rate and arterial oxygen saturation. One brother had EEG changes suggestive of cerebral hypoxia and the other had ventricular extrasystoles at the end of several episodes. Tracheostomy in the younger brother produced a dramatic symptomatic improvement and reduced the number and severity of apnoeic episodes (post-tracheostomy apnoea index 2.4).

Adolescent↗
PubMed1979

Comparative study of automatic blood-gas analysers and their use in analysing arterial and capillary samples.

Three automatic blood-gas analysers were compared for ease of use; calibration; reproducibility and accuracy of results; maintenance; fault-finding; and use of expert technician time. Results obtained from arterial and capillary blood were compared with duplicate values obtained with a semi-automatic analyser controlled and calibrated with tonometered blood. No analyser was fully automatic, and all three needed maintenance by expert technicians. Difficulties were encountered when inexperienced operators used the machines. One automatic blood-gas analyser gave aberrant values for oxygen pressure (PO2) due to electrode dysfunction that was not indicated by the fault-finding system. A second analyser gave significantly lower values for blood pH than the standard machine. A comparison of pH, carbon dioxide pressure (PCO2), and PO2 measured in 40 simultaneous paired samples of arterial and arterialised capillary blood showed no significant difference for pH or PCO2, but the PO2 values were significantly lower in the capillary samples over the range studied. We conclude that all machines perform satisfactorily in terms of blood-gas analysis, but none may be regarded as fully automatic. Some degree of technical supervision is essential, as is proper training for all potential users.

Arteries↗
PubMed1979

Microscopical image analysis: problems and approaches.

This article reviews some of the problems which have been encountered in the application of automatic image analysis to problems in biology. Some of the questions involved in the actual formulation of such a problem for this approach are considered as well as the difficulties in the analysis due to lack of specific constrast in the image and to its complexity. Various practical methods which have been successful in overcoming these problems are outlined, and the question of the desirability of an opto-manual or semi-automatic system as opposed to a fully automatic version is considered.

Computers↗
PubMed1978

A quantitative study of peripheral nerve fibres in the mouse following the administration of drugs. 1. Age changes in untreated CBA mice from 3 to 21 months of age.

This study is concerned with the quantification of changes which occur in peripheral nerves of normal mice from the onset of maturity to old age. The parameters chosen were total fibre area and axon area. Size distributions of these were expressed in the form of histograms. From the area data notional fibre and axon diameters were calculated, together with the thickness of the myelin sheath. The notional diameters were contrasted with the comparable myelin sheath thickness in the form of scatter diagrams. These results are intended to provide a reference scale for subsequent assessment of changes induced by drugs administered throughout life. The are in general accord with previous observations, but were obtained quickly, and with less margins of error, by using a Quantimet 720.

Aging↗
PubMed1973

A quantitative comparison between normal and carcinomatous squamous epithelia of the uterine cervix.

The object of this study was to measure some of the differences between normal squamous epithelial cells and cells from invasive squamous carcinoma of the uterine cervix. A total of 107 patients were studied; only those specimens which when assessed by a histopathologist were thought to show classic normal features or undoubted invasive carcinoma were included in the quantitative analysis. In addition, any specimens which at the electron microscope level, showed faulty sampling or preparation were discarded, leaving us with 16 carcinoma and 15 normal specimens for detailed study.The nuclei of tumour cells had a greater area than those of normal cells; histograms of the size distribution of nuclei showed a distinctly different pattern in the 2 groups. Tumour cells had fewer ribosomes in each cubic micron of cytoplasm than had the normal cells and showed a reduction in the amount of intercellular space; in addition, the malignant cells had a smaller surface density and fewer tonofibrils in their cytoplasm. Some tumour cells had a smaller percentage of cell membrane specialized as desmosomes than the corresponding normal cells but all tumour cells had desmosomes of shorter length than normal.Discriminatory analysis, carried out with the help of a computer, allowed all of these variables to be assessed with respect to each other in order to arrive at a numerical score for each specimen. When expressed graphically, these scores showed that the populations of normal and carcinomatous cells fell into 2 separate groups. The significance of these results is discussed.

Carcinoma, Squamous Cell↗
PubMed1970

Preliminary observations on the histochemistry of the cell surface of carcinoma of the cervix.

Histochemical studies on the cell surface and intercellular matrix of normal cervical epithelium, and squamous cell carcinomata have shown the mucosubstances present may be symbolized by the descriptive formula:C(G) mucosubstance; B 3.5; A 2.5 (0.6m MgCl(2)); T; S.This indicates that sulphate groups are absent and that the intercellular matrix and cell coat are rich in hyaluronic and sialic acids or closely related compounds. These may be important in masking the antigenic expression of the tumour cells.We have not been able to detect any alteration in the mucosubstances at 7 days following radium treatment.

Antigens↗