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Biomedical subjects

D N Slater

Publications and source records attributed to D N Slater.

At least 163 records · Page 9Linked to original sources

Forty years of diarrhoea in a patient with urticaria pigmentosa.

A patient with urticaria pigmentosa who gave a 40-year history of diarrhoea was found to have systemic mastocytosis with gut involvement. The radiological appearance of the gut in this disease, although not widely recognized, are specific and should be looked for carefully in patients with urticaria pigmentosa who complain of gastro-intestinal symptoms. Gastro-intestinal symptoms, due mainly to alterations in bowel motility or peptic ulceration, are said to occur in some 25-50% of cases of systemic mastocytosis (3, 6). These symptoms have usually been ascribed to generalized histamine release acting on the gut, although cases where mast cell infiltration of the bowel has occurred have also been reported (4, 5). In a review of the radiological features (2), increased gastric rugosity with or without evidence of peptic ulceration and nodular space-filling defects of the bowel mucosa were the most commonly found. Occasionally, diffuse thickening of the bowel wall was seen. It was concluded that these appearance were probably due to local release of vasoactive substances causing submucosal oedema following mast cell accumulation in the gut. Another result of such infiltration may be malabsorption (1).

Biopsy↗

Occupational argyria; light and electron microscopic studies and X-ray microanalysis.

Microscopic studies have been performed on skin biopsies from five patients with occupational argyria. Small brown-black granules were present in the dermis on light microscopy and were intensely refractile with dark-field illumination. Electron microscopy showed that the granules were electron-dense, round or oval in shape and varied in size from 30 nm to 100 nm. They were most numerous in relation to the basal lamina of the eccrine sweat glands, but were also present in relation to the basal lamina of the epidermis and dermal elastic fibres. X-ray microanalysis confirmed that many of the granules contained silver and sulphur. However, selenium, mercury, titanium and iron were also identified and it is probable that these elements were deposited in the skin also as a result of occupational exposure.

Adult↗

The effects of steroids and glucagon on the morphological changes in the duct-ligated pancreas of the rat.

Ligation of the rat pancreatic duct produced degeneration of the exocrine acinar tissue, inflammatory cell infiltration and fibrosis. The injection of methyl prednisolone for 5 days following duct ligation produced a marked reduction in the inflammatory-cell infiltrate whereas the administration of glucagon or a combination of glucagon and methyl prednisolone produced only a mild reduction in acinar degeneration. Administration of the drugs for 5 days after duct ligation and examination of the pancreas after 3 months showed no differences in the degree of cellular infiltration and acinar degeneration between controls and those that had received glucagon or glucagon and methyl prednisolone. However, those rats that had received only methyl prednisolone showed fibrosis, a minimal inflammatory-cell infiltrate and a considerable reduction in exocrine tissue. Mild degranulation of the islets of Langerhans was observed in those rats that received methyl prednisolone, alone or in combination with glucagon, and at 3 months the islets appeared normal. The implications for pancreatic transplantation are discussed.

Animals↗

Neonatal islet cell transplantation in the diabetic rat: effect on the renal complications.

PVG/C rats were made diabetic with streptozotocin and after 1 mth received a single intraperitoneal transplant of isogeneic collagenase digested pancreatic tissue. Renal changes have been studied in transplanted and control diabetic rats using light and electron microscopy and immunological techniques. Following transplantation, renal lesions did not increase in severity and progressive basement membrane thickening was prevented. Ultrastructurally many glomeruli showed a significant reduction in the mesangial matrix and the tubular and mesangial cell changes reverted to normal. Immunofluorescent studies demonstrated a similar reduction in the glomerular deposits of IgG. Possibilities for the treatment of diabetes mellitus in human patients are discussed.

Animals↗

Neonatal islet cell transplantation in the diabetic rat: effect on hepatic enzyme activity and glucose homeostasis.

Intraperitoneal transplantation of collagenase-digested, isogeneic, neonatal rat pancreatic tissue successfully reversed streptozotocin-induced diabetes in 77% of recipients. The low serum immunoreactive insulin, hyperglycaemia, glycosuria and weight loss, characteristic of the diabetic animal, were corrected and the reduced activities of hepatic glucokinase and pyruvate kinase, and the low glycogen concentration of the liver of diabetic rats were restored to normal. Forty-three per cent of the successfully transplanted rats became normoglycaemic within 1 month of transplantation whereas 57% took from 1 to 6 months to achieve normoglycaemia and displayed a mild glucose intolerance when subjected to a glucose load. The rats which had not become normoglycaemic 6 months after transplantation showed some amelioration of the diabetic state, as shown by increased serum immunoreactive insulin and hepatic glycogen concentration and a slow weight gain compared with diabetic controls.

Animals↗

Pancreatic ischaemia; sensitivity and reversibility of the changes.

In the rat, pancreatic clamping producing warm ischaemic times ranging from 5 to 90 min gives rise to changes similar to those of an haemorrhagic pancreatitis. The severity of the changes is proportional to the time of ischaemia. After 1 to 1 1/2 h clamping 95 per cent of the glandular changes are reversible, and at 2 months the pancreas appears normal apart from localized areas of fibrosis. The islets of Langerhans remain morphologically normal even after 90 min ischaemia. The implications for islet cell transplantation are discussed.

Adipose Tissue↗

The porcine endothelial cell in tissue culture.

Endothelial cells from porcine aorta and inferior vena cava have been harvested, using trypsin, EDTA or collagenase, and grown in tissue culture. Growth-behaviour, cytology, scanning and electronmicroscopy findings are reported. It is hoped that this technique will prove useful in the investigation of atherosclerosis.

Animals↗

The synthesis of lipids from [1-14C]acetate by human venous endothelium in tissue culture.

Endothelial cells from human umbilical cords were harvested, using a trypsin technique, grown in tissue culture and lipid synthesis studied using [1-14C]acetate as a precursor. Radiosubstrate was incorporated into fatty acids, mono-, di- and triglycerides, cholesterol esters and phospholipids. Radioactivity was also present in the culture medium in the mono-and diglyceride fractions and in the phospholipids running with the solvent front.

Acetates↗