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Biomedical subjects

C Sowter

Publications and source records attributed to C Sowter.

32 records · Page 2Linked to original sources

Sperm size in patients with inflammatory bowel disease on sulfasalazine therapy.

The size of the heads of spermatozoa from eight men with chronic inflammatory bowel disease (IBD) treated with sulfasalazine (SS) were measured by image analysis. These were compared with the size of sperm heads from noncolitic men with normal semen indices and with the sperm head size of noncolitic oligospermic men. The patients on SS therapy had a significantly larger sperm head size for the 99th percentile than the noncolitic oligospermic men. After withdrawal of the drug, sperm head size increased further before becoming smaller. The size did not return to that of the sperm of men with normal semen indices during the period studied. Possible mechanisms for the increase in sperm size are discussed and its association with the reversible infertility caused by SS medication.

Adult↗

Morphometric study of liver cell nuclei in hepatomas using an interactive computer technique: (i) nuclear size and shape.

Liver cells from 20 normal livers and 20 hepatomas have been studied in histological sections using an interactive computer method which measures nuclear size and shape. The variables which gave best discrimination between malignant and benign nuclei were the standard deviations of nuclear shape measurements. Though the liver is an ideal tissue for computer study it is considered that such measurements may act as a model for analysis of nuclei of other tissues.

Carcinoma, Hepatocellular↗

Fibre type changes in striated muscle of alcoholics.

Striated muscle from patients taking more than 80 g of alcohol each day shows selective atrophy of the type II fibres which are dependent on glycogenolytic pathways. This atrophy is associated with an excess of glycogen and lipid within the fibres and may represent a selective metabolic insult.

Adult↗

The relationship between hyperglycaemia and renal immune complex deposition in mice with inherited diabetes.

Kidney lesions were studied by light microscopy and immunofluorescence in diabetic (db/db) and obese (ob/ob) mutant mice. The db/db mutation was studied both on the C57Bl/KsJ genetic background (where it produces severe hyperglycaemia) and on the C57Bl/6J background (where hyperglycaemia is only mild). In all cases, more IgG, IgM and C3 were deposited in the renal glomeruli of mutant mice than in the glomeruli of normal (+/?) mice of equivalent age. First signs of immunoglobulin deposition occurred at a slightly younger age than first signs of C3 deposition or histological change (mainly mesangial thickening). Insulin deposits were occasionally seen in the glomeruli of older mutant mice and immunoglobulin eluted from diabetic mouse kidneys had anti-insulin activity. Increased anti-DNA activity was present in the serum of older mutants. In those mutants with severe hyperglycaemia, the macula densa and distal convoluted tubules also contained immunoglobulin deposits, probably derived from the glomerular mesangium. Urine from diabetic mice contained high molecular weight material reacting with antisera to Fab or kappa but not the Fc portion of immunoglobulin. We conclude that diabetic mice have immune complexes in the kidney containing antibodies against insulin and possibly other antigens. We find no evidence that hyperglycaemia itself is the direct cause of glomerular immune complex deposition, although there may be a link between hyperglycaemia and tubular dysfunction.

Animals↗

Measurement in jejunal biopsies by computer-aided microscopy.

A method of morphometric analysis of jejunal mucosa using computer-aided microscopy is described. It is based on the technique of interactive computer graphics with definition by the observer of areas and lengths for measurement, but it also includes automatic measurements based on grey-level segmentation. The analyses are performed rapidly and efficiently. The technique is applicable to the analysis of biopsy tissue from many sites.

Adult↗

Is genetically transmitted obesity due to an adipose tissue defect?

1. The aim of this investigation was to ascertain of a variety of obese rodents whether the primary cause of fat cell enlargement lay in the fat cell itself, or in its environment. Rodents studied were the mutant mice 'diabetic' (db/db), 'adipose' (dbad/dbad), and 'yellow obese' (Ay/+), New Zealand obese mice, CBA mice made obese with gold thioglucose, and obese BIO 4.24 hamsters. 2. Gonadal fat of obese or lean genotype was transplanted under the kidney capsule of an obese or lean host. Grafts were left in place for at least one month, then examined histologically to measure fat cell diameters, from which fat cell masses were calculated. 3. Immunological rejection of grafts was avoided either by using mice syngeneic except for the obesity producing mutation (db/db, dbad/dbad or Ay/+) or by transplanting into F1 hybrids (NZO X BALB/c) made by mating the strains acting as donors of obese or lean fat. Transplantation of fat between lean BIO 4.22 hamsters and obese BIO 4.24 hamsters was possible because these had common histocompatibility antigens. 4. In all the forms of murine obesity studied, 'lean' fat cells enlarged in an obese recipient to the size typical of cells in 'obese' fat whilst 'obese' fat cells shrunk in a lean recipient to, at least, the size typical of 'lean' fat. Lean hamster fat cells also enlarged in an 'obese' environment and 'obese' hamster cells shrunk in a 'lean' environment. 5. Environment therefore contributes to the determination of fat cell size in all the rodents studied, and in several rodents (db/db, dbad/dbad, Ay/+, and gold thioglucose obese mice) our results showed that environmental factors are of paramount importance in determining cell size, and factors associated with the fat cell itself make a negligible contribution.

Adipose Tissue↗

Evaluation of a new technique for the demonstration of gonococci and other micro-organisms in host cells.

A method (Gram-MGPLG) for demonstrating micro-organisms was compared with Gram and four other known methods. Each method was tested on tissue infected with Staphylococcus aureus, Pseudomonas aeruginosa or Neisseria gonorrhoeae, which were then fixed in Bouin's formol saline, formol sublimate, or Van de Grift solutions. Gram-positive organisms in tissues were easily seen even at low magnification when stained by several of the methods tested. Gram-negative organisms, however, are very difficult to locate when stained by Gram's method because tissue components and the organisms are all shades of red, whereas the Gram-MGPLG provided easier location of organisms because these are stained red while the nuclei are blue and connective tissue is green. All methods are markedly affected by fixation; better preservation of cytological detail and improved staining reactions were produced by fixative containing mercuric chloride.

Evaluation Studies as Topic↗

Human fat cell sizing--a quick, simple method.

Two methods were used to determine the mean cell diameters of 37 samples of human adipose tissue, obtained by open or needle biopsy. Method I was the sizing of cells in cell suspensions and Method II was a quick, simple method of sizing cells from fixed sections. The agreement between the two methods was good (r = 0.93, P = less than 0.001). The results using Method II were slightly lower than those using Method I, and a correction factor is suggested. Method II has several advantages over Method I and we propose that it is a suitable method for sizing cells when a quick method with a permanent record is required.

Adipose Tissue↗