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Biomedical subjects

P Devitt

Publications and source records attributed to P Devitt.

32 records · Page 2Linked to original sources

Release of antral gastrin in response to an intestinal meal in dogs.

This study was designed to determine whether gastrin is released by the antrum in response to an intestinal meal in dogs. Two groups of anesthetized dogs were prepared with innervated antral pouches. The antrum and duodenum were separated by complete division at the pylorus to prevent duodenoantral reflux. The duodenum and proximal jejunum were perfused with 10% liver extract at 200 ml/hr. In one group of six dogs a significant elevation of antral vein gastrin levels was observed after 45 minutes. Gastrin levels in portal and peripheral blood were not significantly elevated. In another group of eight dogs, in which antral veins were not cannulated, a significant rise in peripheral gastrin concentration was noted after 60 minutes. We conclude that gastrin is released by the antrum during the intestinal phase of gastric acid secretion; significantly increased levels of gastrin are detected in both antral and peripheral venous blood. Duodenoantral reflux, as a possible cause of this release, is ruled out by complete surgical separation between duodenum and antrum.

Animals

Pancreatic polypeptide. A review.

Pancreatic polypeptide (PP), 36-amino acid peptide, may function as an important feedback inhibitor of pancreatic secretion after a meal. It arises from both islet and acinar cells of the pancreas. Release of PP by a meal, primarily protein, occurs in a biphasic manner. The first rapid release occurs as a result of vagal stimulation; the second, more prolonged rise (the so-called intestinal phase) occurs in response to hormonal stimulation, predominantly cholecystokinin. Plasma PP levels increase with age; PP levels are elevated above those of age-controlled normal subjects in diabetic patients and in some patients with pancreatic amine precursor uptake decarboxylase tumors. The value of plasma PP as a possible marker for pancreatic tumors is as yet unsettled but may be a valuable tool.

Animals

Does luminal gastrin stimulate gastric acid secretion?

The effects of pentagastrin on acid secretion, short circuit current, electrical conductance and potential difference were determined in isolated bullfrog fundic mucosa. Biologically active luminal pentagastrin had no effect on gastric mucosa, even at a concentration 100 times higher than that necessary for stimulation of the mucosa from the serosal side. It is concluded that luminal gastrin does not appear to have a physiologic role in gastric secretory processes.

Animals

Release of pancreatic polypeptide in humans by infusion of cholecystokinin.

Plasma levels of pancreatic polypeptide were measured after a test meal and after infusion of graded doses of 99% pure cholecystokinin in 6 healthy volunteers. Initial attempts at sterilization of 99% pure cholecystokinin resulted in complete inactivation. Successful sterilization was accomplished by filtration by using specially treated silver-coated filters. Biologic activity of sterilized material was confirmed with cholecystokinin bioassay, and plasma levels of sterilized cholecystokinin achieved by exogenous infusions were measured with a specific cholecystokinin radioimmunoassay. Significant increases in plasma levels of pancreatic polypeptide were found with a test meal and with infusions of 0.25 and 0.5 micrograms/kg-hr of 99% pure cholecystokinin. Integrated values of pancreatic polypeptide released by the low-dose and the high-dose infusions of 99% pure cholecystokinin were 59% and 50% of that obtained by food, respectively. Integrated levels of cholecystokinin after 45 min of infusion of 0.25 micrograms/kg-hr were equal to those after a standard meal. Cholecystokinin, therefore, is an effective humoral releaser of pancreatic polypeptide in humans and may play an important role in the intestinal phase of release of pancreatic polypeptide.

Adult

Short term metronidazole therapy contrasted with povidone-iodine spray in the prevention of wound infection after appendicectomy.

In a prospective, randomized trial metronidazole was found to be significantly better than povidone-iodine in reducing the incidence of wound infection after appendicectomy (P less than 0.005). The metronidazole was given as a established 7-day course. Over 65 per cent of the wound infections presented after the patients had been discharged from hospital.

Aerosols

Emergency geriatric surgical admissions.

The emergency surgical work load created by patients aged 80 and over in a district hospital was assessed and the results of treatment examined. Over one year 248 patients aged 80 or over were admitted as emergencies, and the overall mortality rate was 21.8%. When terminal disease was excluded mortality rate was 12.5%. These elderly patients had an average length of stay in the acute surgical ward of 14.7 days compared with a mean of 8.4 days for all patients, and all but seven patients were discharged to their original place of referral.Elderly patients do exacerbate the bed shortage in acute surgical wards because they tend to stay longer than younger patients, but these elderly surgical patients imposed only a small load on the inpatient geriatric services, as 78% were discharged straight to their own homes and a further 17% went home after a period on the surgical convalescent wards.

Aged

Granular cell myoblastoma of the biliary tree.

A granular cell myoblastoma of the common bile duct is described which caused episodes of jaundice in a young woman. Histological examination demonstrated a close association of the tumour with nerve fibres, tending to support the theory of origin from Schwann cells. The lesion is benign and after excision carries an excellent prognosis.

Adolescent

The effect of vasopressin on hepatic artery flow in the rat.

The effects of vasopressin infusion on hepatic artery flow was studied in rats. Hepatic artery ligation followed by the infusion of vasopressin (0.08 microU/g body weight per min) decreases portal venous flow and liver blood flow. Vasopressin infusion results in an increase in hepatic artery flow and liver blood flow both of which are abolished by subsequent hepatic artery ligation. The increase in hepatic artery flow and the decrease in portal venous flow following the infusion of vasopressin is discussed in relation to the management of patients presenting with bleeding oesophageal varices.

Animals

Circulating levels of arginine vasopressin before and during the infusion of the hormone in patients presenting with bleeding oesophageal varices.

Circulating levels of antidiuretic hormone (ADH) were measured in patients presenting with bleeding oesophageal varices before and during treatment with arginine vasopressin. There was no significant difference in the circulating levels of ADH before and during treatment with arginine vasopressin in patients in which the hormone successfully controlled haemorrhage and those in which it did not. It is concluded that the failure of vasopressin to control variceal haemorrhage in approximately 40% of patients presenting for treatment cannot be attributed to higher circulating levels of the hormone in these subjects.

Arginine Vasopressin

Oncology/quality assurance: a quality system for oncology nursing.

The benefits of three quality monitoring systems, Monitor, Qualpacs and the Dynamic Standards Setting System are explored in relation to oncology nursing. The author concludes that the flexibility provided by the 'bottom-up' design of the Dynamic Standards Setting System is admirably suited to the needs of nurses working with cancer patients.

Humans