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Biomedical subjects

T G Parks

Publications and source records attributed to T G Parks.

At least 73 records · Page 4Linked to original sources

Solitary rectal ulcer syndrome in Northern Ireland. 1971-1980.

Fifty-one cases of solitary rectal ulcer syndrome diagnosed over the past 10 years have been studied. The syndrome, of which solitary ulceration was a feature in only 35 per cent of cases, included patients with multiple 'solitary' ulcers (22 per cent), broad-based polypoid lesions (25 per cent) and patchy granular hyperaemic rectal mucosa (18 per cent). The syndrome was found to be strongly associated with abnormal rectal descent. Full-thickness prolapse to or beyond the anal verge was present in 59 per cent of patients while a further 32 per cent had lesser degrees of rectal descent. In only 9 per cent was no such abnormality demonstrated. Treatment with high roughage diet supplemented with bulking agents benefited two-thirds of 27 patients so treated. Ivalon sponge rectopexy has been performed in 6 patients with associated complete rectal prolapse, and in the first 3 of these (followed for a sufficient period) the results have been satisfactory.

Adolescent↗

The assessment of mucus substances in gastric juice from duodenal ulcer patients and normal subjects.

The carbohydrate and nitrogen content of the gastric juice was assessed in 18 persons whose diagnosis were unknown to the investigators and the data compared by discriminant function analysis with similar measurements from 42 patients with proven duodenal ulceration and 22 normal controls. It was possible to assess correctly 14 of the 18 patients (77.8%) of the unknown group as having a duodenal ulcer. The results of three patients (16.7%) were equivocal, and one person (5.5%) was wrongly classified. The investigation confirms that the carbohydrate and nitrogen content of gastric secretion in duodenal ulcer patients is abnormal.

Adolescent↗

The release of vasoactive intestinal peptide during altered mid-gut blood flow.

In a series of 17 dogs of which 6 were controls experiments were undertaken to measure arterial and portal vasoactive intestinal peptide (VIP) levels during reduced cephalic mesenteric artery flow states and following reperfusion of the ischaemic mid gut. The flow states examined were basal flow, 50 per cent of basal flow and 25 per cent of basal flow. Zero flow was examined for 20 min and reperfusion of the ischaemic mid gut for 20 min. Peripheral and portal VIP levels were found to be massively elevated during all the flow states studied but particularly during reperfusion of the ischaemic mid gut.

Anesthesia↗

Proximal gastric vagotomy, fundoplication, and lesser-curve necrosis.

Out of 400 patients who underwent proximal gastric vagotomy (PGV), three developed lesser-curve necrosis (LCN) leading to perforation within the first seven days. In each case diagnosis was delayed but the patient survived after a second operation. In each an associated Nissen fundoplication had been carried out; we used the combined operation in only 33 patients. Delayed LCN occurred in a patient who had undergone splenectomy at the time of the PGV and in a fifth patient treated elsewhere who had also undergone fundoplication. These findings indicate that early postoperative gastric distension with gas, not readily voided after fundoplication, may aggravate local vascular factors and predispose to LCN. We suggest that PGV combined with fundoplication may be dangerous.

Adult↗

The problems of massive small bowel resection and difficulties encountered in management.

Massive small bowel resection is imperative in the management of several pathological conditions and is accompanied by high operative mortality. In those that survive, serious nutritional disturbances are inevitable. Intestinal adaptation is said to occur but cannot be relied upon. Long-term parenteral nutrition is problematical and often unsuccessful. Many surgical procedures have been adopted in an effort to improve prognosis and have been found wanting. Controlled experimental studies in the use of reversed segments and a limited number of reported clinical cases using the method after massive resection suggest that this technique may improve the function of the residual intestine to such an extent that other supportive measures are unnecessary.

Adaptation, Physiological↗

Ischaemic colitis in the experimental animal. I. Comparison of the effects of acute and subacute vascular occlusion.

Acute ligation of the common colic and caudal mesenteric artery in the dog led to ischaemic colitis, whereas the acute ligation of the common colic artery and gradual occlusion of the caudal mesenteric artery by an ameroid plastic device did not lead to ischaemic disease. These findings suggest that the collateral blood vessels do not open up rapidly enough to prevent ischaemic change when the two major arteries are acutely ligated.

Animals↗

Ischaemic colitis in the experimental animal. II. Role of hypovolaemia in the production of the disease.

Hypovolaemia alone did not lead to ischaemic colitis but when venesection was induced immediately after the acute ligation of the common colic artery large bowel ischaemia ensued. Similarly, hypovolaemia induced one month after two major blood vessels had been occluded led to ischaemic colitis. These findings suggest that states of low blood flow in the presence of previous arterial constriction or blockage may lead to enough reduction in mesenteric perfusion for intestinal ischaemia to develop. Using an electromagnetic flowmeter placed in the cranial mesenteric artery of the dog, it was shown that hypovolaemia may lead to 50-75% reduction in mesenteric blood flow without producing any significant change in the systemic blood pressure.

Animals↗

The vagus, the duodenal brake, and gastric emptying.

It has been suggested that an intact vagal supply is essential for the normal function of the recptors in the duodenum and proximal small bowel, which influence the rate of gastric emptying. This paper reports the effect of vagal denervation on gastric emptying and also examines the site and mode of action of receptors in the proximal small bowel. It has been demonstrated in the dog that most, if not all, the receptors controlling gastric emptying lie in the proximal 50 cm of the small bowel. Following truncal vagotomy the emptying time of each instillation increased significantly and the differential rate of emptying of different instillations remained unchanged. The proximal 50 cm of small bowel was capable to differentiating between different instillates even after selective extragastric vagotomy, in which the duodenum was vagally denervated and, therefore, duodenal braking receptors function independently of vagal innervation.

Animals↗