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Biomedical subjects

J G Duncan

Publications and source records attributed to J G Duncan.

34 records · Page 2Linked to original sources

Liver volume determination by ultrasound: a feasibility study.

The feasibility and precision of an ultrasound method for determining the volume of the liver have been assessed using a Nuclear Enterprises B-scan machine. A relation between estimated liver volume and body weight has been established, showing that liver volume can be determined with a precision of +/- 195 cm3 (P less than or equal 0-05). With the standard non-grey-scale imaging technique employed there is a degree of uncertainty in deciding the liver boundaries, and this constitutes the major source of error.

Anthropometry↗

Ultrasound in the management of acute pancreatitis.

Thirty-eight patients have been examined by ultrasound when symptoms or sign suggested the development of a pseudocyst following an attack of proven acute pancreatitis. Pseudocyst was diagnosed in 23 of the 38 cases. Five patients had multilocular cysts, four of which were shown to be communicating. Laparotomy was carried out on 14 of the 23 patients and surgical drainage was performed in 12 cases. The remaining nine cases were monitored and showed steady regression. Small cysts arising in the head of pancreas may give rise to recurrent or persistent pancreatitis and may be demonstrated pre-operatively by ultrasound but not readily by other means. A further 12 patients showed an area of irregular absorption of ultrasound interpreted as an inflammatory mass. Monitoring of these cases showed progressive resolution without cyst formation. Three of these cases subsequently required laparotomy-one developed an abscess and one necrosis of the body and tail of pancreas while a third developed severe pancreatic fibrosis of the area identified by ultrasound. The ability to distinguish between pseudocysts and inflammatory masses and to demonstrate communication between multiple cysts is of considerable value in pre-operative diagnosis.

Acute Disease↗

Absorption of histamine from the gastrointestinal tract of dogs in vivo.

1. In anaesthetized dogs, various amounts of [(14)C]histamine were introduced into the lumen of a ligated intestinal loop or of the ligated stomach and the absorption of this histamine was studied by determining the radioactive histamine in the venous blood coming from the ligated part.2. After the introduction of 5-5000 mug [(14)C]histamine, into a loop of jejunum, or of 50 mug into a loop of duodenum, ileum or colon, radioactive histamine was detected in all eight successive 15 min samples of venous blood collected during 2 hr. The percentage recovery of the [(14)C]histamine in the blood during this period varied between 0.04 and 3.7.3. After the introduction of 10 mg [(14)C]histamine into the stomach, radioactive histamine was detected in all samples of gastric venous blood collected at various times during the following 4 hr.4. After the introduction of 50-5000 mug [(14)C]histamine into a loop of jejunum, radioactive histamine was also detected in the general arterial blood.5. When a jejunal loop was perfused through its artery with a dextransaline solution, the absorption of [(14)C]histamine from the lumen into the venous effluent was much greater than when the blood supply was kept intact.6. A large part of the [(14)C]histamine introduced into an intestinal loop was inactivated or destroyed either in the lumen or the wall since only a part was recovered in the venous blood, contents and wall of the loop at the end of 2 hr. When different amounts of [(14)C]histamine were introduced into a jejunal loop the recovery was shown to be dependent on the dose. With 5 mug it amounted to about 1% whereas with 5000 mug to 29-42%. The recovery of the [(14)C]histamine introduced into a perfused jejunal loop was greater.7. In dogs and cats large amounts of free histamine were found in the contents of the stomach 2 hr after a meat meal, and much smaller amounts in the contents of loops from the small intestine. The amounts found in the contents of loops from the colon varied greatly.8. In eighteen commercial dog and cat foods the free histamine contents were found to vary over fiftyfold, from 0.06 to 3.5 mg/100 g.9. The significance of the results is discussed in relation to the role of histamine as a humoral agent in the ;gastric' and ;intestinal phases' of gastric secretion.

Absorption↗