Biomedical subjects

A Smythe

Publications and source records attributed to A Smythe.

8 recordsLinked to original sources

PubMed1992

Continuous monitoring of sodium ion concentration in the human stomach--a new technique for the detection of duodenogastric reflux.

Measurement of sodium ion concentration in gastric juice offers a simple means of detecting duodenogastric reflux (DGR). Using aspirated gastric juice, we measured sodium ion concentration, bile acid levels and phospholipase A2 activity and found that sodium ion levels increase along with these other standard markers during DGR. Following this, using a sodium ion selective electrode and a portable data logger, continuous recordings of sodium ion concentration were made in the human stomach. These studies demonstrated the ability of sodium ion monitoring to detect major DGR episodes in the body of the stomach.

Adult↗

PubMed1979

Does obstructive jaundice adversely affect wound healing?

The effect of obstructive jaundice on wound healing has been investigated in an experimental study of abdominal wounds in rats following ligation and division of the common bile duct. Animals were jaundiced for 2 weeks before a second operation at which the abdominal wounds were made. The wounds in jaundiced and control animals showed no significant differences in mechanical strength during a 21-day period of study but there was a significant delay in the accumulation of collagen in the wounds of jaundiced animals. The findings suggest that the biochemical changes in the wounds of jaundiced animals did not interfere with wound repair and cast doubt on the thesis that jaundice has an adverse effect on wound healing.

Abdomen↗

PubMed1978

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↗

PubMed1978

Ascorbic acid requirements in postoperative patients.

The postoperative ascorbic acid requirements of 63 surgical patients were assessed by measurements of buffy layer leukocyte ascorbic acid and the ascorbic acid content of leukocytes. There was a significant reduction in ascorbic acid levels following operation. The postoperative changes were unrelated to the extent of surgical trauma or the volume of blood transfused during operation, but there was a significant correlation between postoperative ascorbic acid measurements and white blood counts. It appears that postoperative leukocytosis and release by the bone marrow of leukocytes with a low ascorbic acid content may partly account for the postoperative changes in buffy layer and leukocyte ascorbic acid measurements. However, surgical operations were followed by an authentic increase in ascorbic acid requirements, and there was a 42 per cent reduction in circulating leukocyte ascorbic acid levels on the third postoperative day. The findings of this study create an argument for the use of ascorbic acid supplements in surgical patients, although it is unlikely that postoperative changes in leukocyte ascorbic acid have pathologic significance in wound repair.

Aged↗

PubMed1977

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↗

PubMed1976

The rejection of islets of Langerhans following intrahepatic transplantation in the rat.

Pancreatic acinar tissue and islets of Langerhans have been isolated using a collagenase technique from Agus rats and transplanted separately into the liver of diabetic and nondiabetic isogeneic Agus and allogenic PVG/C rats. Livers were removed on days 1, 2, 4, 7 and 14 and examined histologically. Transplanted isogeneic islets showed no evidence of cellular infiltration and the beta cells appeared fully granulated. Transplanted allogeneic islets in non-diabetic recipients were surrounded by a mononuclear cellular infiltrate on day 2 and this became maximal by day 4. Although initially fully granulated, beta cells became degranulated on day 7 and by day 14 only small fragments of islet tissue remained. In allogeneic diabetic recipients the cellular infiltrate appeared less dense; beta cells appeared incompletely granulated from days 1 to 4 and a transient fatty degeneration occurred in the hepatic parenchuma around islets.

Animals↗

PubMed1975

The influence of exogenous PMS and HCG on the arachidonic acid content of the immature rat ovary.

The influence of exogenous PMS and/or HCG, on the arachidonic acid (C 20:4omega6) content of the immature rat ovary was examined. Changes in ovarian arachidonate content associated with hormone administration were assessed in total lipid extracts, and in several neutral and phospholipid fractions. Both relative percentage and absolute amounts of arachidonic acid in several lipids were measured as well as uptake of radioactivity into total lipid resulting from the administration of 3H-labeled arachidonic acid in vivo. On the basis of these studies, we conclude (1) PMS, with or without HCG promotes increased uptake of exogenous arachidonic acid into ovarian total lipids; (2) Arachidonic acid is a mojor fatty acid constituent from noncholine containing phosphatides at the onset of normal estrous (ca. 38 days) even in the animals which received no PMS or HCG; (3) Changes in ovarian arachidonic acid levels following gonadotropin administration are more striking in the two phospholipid fractions than in the two neutral lips examined; (4) PMS is associated with a rapid outpouring of ovarian lipid, accompanied by a high turnover of arachidonic acid which is enhanced or modified temporally by added HCG in vivo. These results provide the first quantitative evidence that gonadotropins may regulate prostaglandin biosynthesis in the ovary by their effects on the uptake, storage, or release of arachidonic acid, a major PG precursor, from specific ovarian lipids. While the data strongly suggest that the regulation of one or more ovarian esterases (cholesterol esterase, lipase, phospholipase) is the mechanism by which gonadotropins regulate PG biosynthesis, a direct action on PG synthetase is not ruled out.

Animals↗

PubMed1975

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↗