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Biomedical subjects

R R Dozois

Publications and source records attributed to R R Dozois.

At least 163 records · Page 9Linked to original sources
PubMed1979

Effect of proximal gastric vagotomy and truncal vagotomy and pyloroplasty on gastric functions and growth in puppies after massive small bowel resection.

The effects of truncal vagotomy and pyloroplasty and proximal gastric vagotomy on gastric acid hypersecretion, hypergastrinemia, and growth after massive bowel resection were studied in beagle puppies. In puppies with 80% enterectomy, neither type of vagotomy alters significantly the postprandial hypersecretion of acid from the Heidenhain pouch or the concentration of serum gastrin. Proximal gastric vagotomy tended to decrease the hypersecretion more than did truncal vagotomy. In beagle puppies undergoing 70% small bowel resection, growth was significantly decreased but survival was not impaired. Neither proximal gastric vagotomy nor truncal vagotomy and pyloroplasty reversed completely the impaired growth produced by massive resection. Proximal gastric vagotomy caused a small improvements in growth, while truncal vagotomy and pyloroplasty resulted in a slight decrease in growth. It remains possible that proximal gastric vagotomy could be of value in the management of growing infants with hypersecretion of acid due to short bowel syndrome.

Animals↗
PubMed1979

The continent ileostomy: a viable alternative.

The continent ileostomy is one of the alternative techniques in managing patients who require a proctocolectomy. Although previously plagued with up to 30% revisions, the continent ileostomy appears to contribute significantly to the social and psychologic well-being of these patients. Our experience suggests that improved surgical techniques make this procedure a safe and favorable alternative to the traditional Brooke ileostomy.

Adolescent↗
PubMed1978

Leiomyosarcoma of the small and large bowel.

From 1950 through 1974, a total of 108 cases of primary intestinal leiomyosarcoma were seen at the Mayo Clinic. Most of these uncommon tumors occurred in the fifth and sixth decades of life, and more of them in men than in women (2.6:1). There were 73% in the small bowel, 25% in the large bowel, and 2% in the anus. Gastrointestinal bleeding and pain were the two most common signs at presentation, and they led to surgical exploration in all cases where they appeared. By the time surgery was performed, only 48% of the tumors could be resected with hope of cure. Within that group of cases, 50% of the patients survived 5 years, but only 35% survived 10 years, late recurrence being common. The histologic grade of the tumor affected survival to erroneous early optimism in prognosis.

Adult↗
PubMed1978

Stimulation of adenylate cyclase in homogenates of isolated intestinal epithelial cells from hamsters. Effects of gastrointestinal hormones, prostaglandins, and deoxycholic and ricinoleic acids.

The mechanism by which intestinal secretagogues evoke fluid secretion in the small bowel and colon has been suggested to involve mucosal adenylate cyclase. Adenylate cyclase activity was assayed by conversion of [32P]ATP to [32P]cyclic AMP in a system of pure epithelial cells isolated from the small intestine of the hamster by vibration in buffer. Several gastrointestinal hormones were tested for their capacity to stimulate adenylate cyclase; vasoactive intestinal peptide and impure cholecystokinin-pancreozymin (but not the 99% pure preparation or pure cholecystokinin octapeptide) were potent stimuli, but pentagastrin, glucagon, secretin, and gastric inhibitory peptide were impotent. Two prostaglandins, PGE1 and PGE2, were potent stimuli of adenylate cyclase. Two other compounds that provoke intestinal secretion of fluid, deoxycholic acid and ricinoleic acid (castor oil), were ineffective stimuli of adenylate cyclase. These experiments do not support a clear-cut relationship between a compound's ability to stimulate adenylate cylase and its activity as an intestinal secretagogue.

Adenylyl Cyclases↗
PubMed1977

Increased meal-stimulated gastric acid secretion and serum gastrin after extensive small bowel resection in puppies.

In six beagle puppies provided with vagally denervated pouches of the oxyntic gland area, the effects of massive resection of the small intestine on acid secretion and serum gastrin induced by feeding were studied. The enterectomies produced significant postprandial hypersecretion of acid and hypergastrinemia. A linear correlation existed between the increased acid output and serum gastrin level.

Adult↗
PubMed1977

Effect of histamine on canine gastric mucosal adenylate cyclase.

The effects of histamine, Nalpha-dimethylhistamine, 4,5-methylhistamine, Ntau-methylhistamine, pentagastrin, carbachol, and NaF on the adenylate cyclase activity from canine gastric mucosa were investigated in cell-free preparations. In gastric fundic mucosa, histamine (10(-4) M), Nalpha-dimethylhistamine (10(-4) M), 4,5-methylhistamine (10(-4 M), and NaF (10)-2) M) significantly (P less than 0.001) increased adenylate cyclase activity (means+/-SE) by 44.7+/-6.6, 49.4+/-6.7, 34.0+/-6.4, and 572.0+/-100%, respectively, above basal activity. The effect of histamine and Na-dimethyl histamine was dose-dependent. In contrast, other tested agents failed to stimulate the formation of cyclic AMP in gastric fundic mucosa. Metiamide (10(-4) M) blocked the stimulation of fundic mucosa adenylate cyclase by histamine and Nalpha-dimethylhistamine, without significantly altering basal and NaF-induced adenylate cyclase activity. Histamine, however, did not stimulate the adenylate cyclase activity from the gastric antral mucosa. The findings support the proposal that the canine gastric acid response to histamine may be mediated by cyclic AMP formed in response to stimulation of histamine H2-receptors.

Adenylyl Cyclases↗
PubMed1977

Interrelationships between histamine, prostaglandins, and cyclic AMP in gastric secretion: a hypothesis.

Based on the current experimental evidence, a model is proposed for mutual interactions of histamine, prostaglandins, and cyclic AMP in regulation of gastric secretion and pathogenesis of peptic ulcer. Histamine acting on H2-receptor-associated adenylate cyclase stimulates cyclic AMP formation and consequently secretion of hydrochloric acid in oxyntic cells. Prostaglandins (mainly E type) in another cell population stimulate cyclic AMP formation which may lead to formation of glycosaminoglycans and glycoproteins. Glycosaminoglycans and glycoproteins may have antisecretory and cytoprotective properties. In addition to this effect, prostaglandin endoperoxides may inhibit histamine-stimulated cyclic AMP formation in oxyntic cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1977

Menetrier's disease. Effect of medical and surgical vagotomy.

A 62-year-old woman with incapacitating atherosclerotic vascular occlusive disease was found to have severe hypoproteinemia as a result of Menetrier's disease. That diagnosis was suspected on roentgenographic and gastroscopic examinations and confirmed by examination of full-thickness surgical gastric biopsy specimens. The protein loss from the stomach was significantly decreased by treatment with trimethaphan and atropine and led us to perform proximal gastric vagotomy at the time of endarterectomy. Subsequent protein turnover studies suggest that there has been a significant decrease in protein loss by the stomach. Further evaluation of the possible role of medical and surgical vagotomy in this disease seems warranted.

Atropine↗
PubMed1977

Effect of proximal gastric vagotomy on gastric acid hypersecretion and hypergastrinemia after massive small bowel resection in dogs.

Fasting and postprandial gastric acid secretion and gastrin were determined in Heidenhain pouch dogs before (C) and after (R) massive enterectomy (five dogs) and after additional proximal gastric vagotomy (PGV) in three dogs. Basal acid output was unchanged (C = 7 +/- 2 microneq/hour; R = 11 +/- 4 microneq/hour), but postprandially the hourly (third through eighth hour) and cumulative acid outputs (C = 3.6 +/- 0.3 mEq/8 hour; R = 7.2 +/- 0.4 MEq/8 hour) were significantly increased by resection (P less than 0.001). Similarly, fasting gastrin was unaltered by resection (C = 41 +/- 2 pg/ml; R = 46 +/- 8 pg/ml), whereas hourly gastrin concentrations significantly (P less than 0.05) exceeded control values. Increased gastrin correlated linearly (P less than 0.02) with increased acid output. After PGV, basal acid levels remained unchanged (R = 4 +/- 2 micronEq/hour; PGV = 9 +/- 4 micronEq/hour), but postprandial acid output significantly exceeded prevagotomy values at all time periods (P less than 0.05). Cumulative acid output also was increased (R = 6.8 +/- 0.6 MEq/8 hour; PGV = 11.2 +/- 0.6 mEq/8 hour; P less than 0.001). Serum gastrin, however, remained unchanged. Hypersecretion of acid from Heidenhain pouches after massive enterectomy is increased further by PGV without a concomitant increase in serum gastrin.

Animals↗
PubMed1977

Relationships between fasting and postprandial pancreaticoduodenal pressures, pancreatic secretion, and duodenal volume flow in the dog.

We have developed a canine model which allows simultaneous quantification of pancreatic enzyme outputs, duodenal volume flow, and pancreatic and duodenal pressures under physiological circumstances. Twelve studies on 4 conscious healthy dogs demonstrated that mean fasting pancreatic pressure was 5 to 10 cm H2O higher than mean fasting duodenal pressure. Furthermore, 8 min after ingestion of a meal, both the pancreatic and the duodenal pressure increased. Surprisingly, the mean duodenal pressure was higher than the mean pancreatic pressure 20 min after feeding. This relationship lasted for 30 min. Lastly, elevation of postprandial pancreatic pressure occurred concomitantly with increased pancreatic enzyme output, and duodenal pressure increased with increased duodenal volume flow. The observed large postprandial duodenal volume flows associated with duodenal pressures greater than pancreatic duct pressures may favor reflux of duodenal contents into the pancreatic duct. These relationships may be important in the pathogenesis of postprandial pancreatitis and in the induction of pancreatic cancer.

Animals↗
PubMed1976

Gastric secretion and motility in duodenal ulcer: effect of current vagotomies.

Proximal gastric vagotomy, total gastric vagotomy, and truncal vagotomy all decrease gastric secretion of acid and pepsinogen, increase the concentration of gastrin in the serum, impair gastric receptive relaxation and accommodation, and speed gastric emptying of liquids. Only proximal gastric vagotomy preserves antral motility, gastric emptying of solids, and the pyloric barrier to duodenal-gastric reflux.

Duodenal Ulcer↗
PubMed1976

Closure of abdominal incisions with subcutaneous catheters.

Five hundred patients who underwent a variety of major abdominal operations had primary closure of their abdominal incisions. The technique of closure included the use of catheters in the subcutaneous space with suction, except when an antibiotic solution was being instilled every 8 hours of the first 9 days after operation. The rate of postoperative wound infection in these 500 patients, a group which included 140 patients who had contaminated or dirty wounds, was 0.8 percent. Infection developed in only one (0.47 percent) of the 211 patients who underwent major colon procedures. No significant side-effects of treatment were observed.

Abdomen↗