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Biomedical subjects

A Fich

Publications and source records attributed to A Fich.

At least 55 records · Page 3Linked to original sources
PubMed1991

Canine ileocolonic sphincter: flow, transit, and motility before and after sphincterotomy.

Our hypothesis was that the canine ileocolonic sphincter (ICS), per se, would have little regulatory effect on the transit of chyme from ileum to colon. We argued, from earlier observations, that the ileocolonic junction was influenced more by functional motor integration of the ileum, ICS, and proximal colon. In five dogs, the ileocolonic sphincter was ablated by extramucosal sphincterotomy; the operation significantly lowered tonic pressures at the ICS. Animals were then studied in the fasting state and postprandially. Ileal flow was estimated by marker dilution, and ileocolonic flow was estimated by total recovery of chyme from a colonic cannula. Transit times were measured after the bolus infusion of nonabsorbable markers. Ileocolonic sphincterotomy did not significantly alter flow rates or transit times of chyme across the ICS, although ileal motor patterns were changed after sphincterotomy. We concluded that the ICS probably has only a small effect on transit and flow at the ileocolonic junction. These findings argue for the importance of integrated motility of the ileum, ICS, and proximal colon in controlling the flow of chyme in this region.

Animals↗
PubMed1991

Measurement of tone in canine colon.

We sought to determine whether the proximal colon modifies its capacity to accommodate contents by altering the tone within its wall. In dogs equipped with manometric recorders in the terminal ileum and proximal colon, a highly compliant bag was introduced into the proximal colon. With the use of an electromechanical barostat, the capacity of the colonic segment was monitored at a constant low-distending pressure; the volume of air required to maintain a preset pressure in the bag was recorded by the barostat. During fasting, rhythmic cycles of volume were recorded, with a cycle frequency of approximately 1/min. Importantly, this phenomenon was not related to the simultaneous recording of manometric pressures in the adjacent bowel or to the interdigestive cycle (phase III) in the ileum. Peristaltic-like pressure complexes (recorded manometrically) in the ileocolonic region were associated with receptive relaxation of the proximal colon. Feeding, bethanechol, and morphine reduced volumes accommodated in the bag, presumably by increasing tone in the wall of the colon. Atropine had the opposite effect. These results support the concept that tonic changes in the wall of the proximal colon, which could influence accommodation and storage in the large bowel, are not always recorded by conventional techniques.

Animals↗
PubMed1990

Does Helicobacter pylori colonize the gastric mucosa of Meckel's diverticulum?

Helicobacter pylori (formerly, Campylobacter pylori) is a highly adapted organism that seems to infect only gastric-type mucosa. In this study, we attempted to determine whether gastric epithelium at a site distant from the stomach, the heterotopic gastric mucosa of Meckel's diverticulum, was susceptible to colonization by H. pylori. Retrospectively, we examined biopsy specimens from 23 patients who had undergone resection of Meckel's diverticulum that contained heterotopic gastric mucosa. As a methodologic control, we also reviewed antral biopsy specimens from 18 patients with chronic duodenal ulcer who had undergone antrectomy. Heterotopic gastric mucosa in Meckel's diverticulum was of antral type in 13 patients and fundic type in 10 patients. Six patients had an ulcer in the diverticulum. No evidence of chronic or active chronic gastritis was detected in the heterotopic gastric mucosa. H. pylori was not found in any Meckel's diverticula but was present in the antrum of 89% of patients with duodenal ulcer. These results suggest that H. pylori may not colonize the heterotopic gastric mucosa of Meckel's diverticulum and has no role in the development of ulceration at this site.

Adolescent↗
PubMed1990

Regulation of postprandial motility in the canine ileum.

We describe here further observations on a novel motor phenomenon that can be recorded regularly from the canine ileum in the late postprandial period, i.e., when residue of a meal reaches the distal small bowel. We reported before that this unique pattern of motility consisted of intraluminal pressure waves at a frequency (20-24/min) much greater than that of the ileal slow wave. In the current experiments, we document that these intraluminal pressure waves coincide with contraction of the circular muscle layer, as recorded from serosal strain gauges. However, the cellular origin and propagation of these contractile events are still unclear. By studying dogs with ileal loops and those with an intact bowel, we conclude that this is a local response of the ileum to the arrival of nutrients in its lumen and that it is under cholinergic control. This report supports the concept that the ileum may be particularly sensitive to its local intraluminal environment.

Animals↗
PubMed1990

Stasis syndromes following gastric surgery: clinical and motility features of 60 symptomatic patients.

We retrospectively reviewed the records of 60 patients who had been referred for gastrointestinal manometry because of stasis after gastric surgery. Nausea, vomiting, bloating, abdominal pain, and weight loss were the most common symptoms. Two thirds of these patients had a well-documented history of peptic ulcer before their initial operations; in others, surgery was performed for other reasons, such as obesity (5%) or reflux esophagitis (8%). Twelve patients had undergone truncal vagotomy and a "drainage operation" and 48 had received a partial gastrectomy with a gastroenterostomy: Billroth I (n = 8), Billroth II (n = 11), Roux-en-Y (n = 29). All patients had recordings of gastrointestinal manometry; 16 also had a scintigraphic measurement of gastric emptying. Measurements were compared with data from healthy controls. Gastric manometry, which could be assessed only in the group with an intact antrum, was characterized by antral hypomotility (p less than 0.05). Gastric emptying studies showed rapid early emptying of liquids and delayed emptying of solids (both p less than 0.05). In the whole group, fasting jejunal motility was characterized by absence of phase II in 13, presence of bursts of phasic activity in 18, and abnormal propagation of phase III in 8. A significantly increased frequency of phase III of MMC was noted in the patients after Billroth II and Roux-en-Y operations. Postprandially, 19 patients failed to develop a "fed pattern."(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Stimulation of ileal emptying by short-chain fatty acids.

We have shown previously that short-chain fatty acids (mixtures of acetic, propionic, and butyric acids; SCFAs) in the proportions found usually in stool water stimulate fasting ileal motility. Based on indirect evidence, we proposed that these motor patterns (bursts of phasic pressure waves that were propagated) would be propulsive, but the capacity of these stimulated patterns of motility to propel contents has not been established directly. Healthy, surviving dogs were provided with motility sensors and a cannula through which SCFAs could be instilled into the ileum. Boluses of SCFAs were much more likely to stimulate phasic bursts of motility than was saline. Scintigraphic studies using a gamma camera showed that the motility stimulated by SCFAs was propulsive and that the ileum was thereby emptied. We also tested whether SCFAs were equally effective stimuli during fasting and after food. SCFAs were equally effective during fasting and soon after food, but in the late postprandial period, when the meal reached the ileum, SCFAs were much less likely to stimulate motility. These observations shed further light on the capacity of the ileum to sense and react to the nature of the contents.

Animals↗
PubMed1989

Indomethacin-induced gastroduodenal damage is not affected by cotreatment with ranitidine.

A randomized, double-blind, placebo-controlled study was conducted to determine whether concomitant administration of ranitidine reduces gastroduodenal mucosal damage associated with 1 week of indomethacin treatment. One hundred ten subjects with acute musculoskeletal conditions and who received indomethacin 150 mg/day completed the trial: 55 were treated with ranitidine 150 mg b.i.d. and 51 subjects received placebo b.i.d. Endoscopic gastric and duodenal injury were assessed before and after one week of treatment. There was no statistically significant difference in the percentage of patients with gastroduodenal damage or in the severity of the lesions in both treatment groups. Ranitidine did not ameliorate indomethacin-induced gastrointestinal symptoms and there was no correlation between upper gastrointestinal symptoms and endoscopic findings.

Adolescent↗
PubMed1989

Effect of age on human gastric and small bowel motility.

To test the hypothesis that age alters fasting and postprandial antral and intestinal motility in humans, we studied 23 patients, aged 18-39 years (median 28), and 13 patients, aged 40-69 years (median 49). All were having gastrointestinal symptoms, but in none was there objective clinical, radiologic, or endoscopic features of bowel disease, and manometry of the stomach and proximal small bowel was normal. We quantitated certain parameters of fasting intestinal motility and postprandial antral and jejunal motility. There were no significant differences in the interval between interdigestive motor complexes (IMC), duration, propagation velocity, or maximum number of contractions during phase III of the IMC, or postprandial antral and jejunal motility indices. The postprandial indices show a very similar distribution in each decade. Thus, in selected patients with unexplained gastrointestinal symptoms but no objective features of gut disease, quantifiable gastric and small bowel motility parameters do not differ in the age groups 18-39 and 40-69 years.

Adult↗
PubMed1989

Rapid frequency rhythmic postprandial motility in the canine ileum.

We report here a novel motor phenomenon that we recorded from the canine terminal ileum in the postprandial period. In chronic models that allowed us to monitor myoelectrical activity and intraluminal pressure from the jejunum and distal ileum, we regularly saw in the ileum, but not in the jejunum, a rhythmic sequence of intraluminal pressure waves at a frequency of 19-24 cycles/min. This unusual motor pattern was rarely seen in the first 2 h after food and was essentially absent during fasting; it appeared reproducibly 1-4 h after food, at the time when chyme reached the ileum. The phenomenon was accompanied by spike bursts that were usually at the same rapid, rhythmic frequency, but the rate of the ileal slow wave persisted at the preprandial level (13-15/min). These findings further exemplify differences in the regulation of the motility between jejunum and ileum; moreover, the phenomenon highlights the capacity of the distal small intestine to response specifically to the nature of its luminal contents. This reaction of the ileum to the arrival of dietary residues is deserving of further study in the evaluation of the small bowel's response to a meal.

Animals↗
PubMed1988

Effect of chronic misoprostol ingestion on rat gastric morphology and cell turnover.

The effect of long-term misoprostol - a synthetic prostaglandin E1 analogue - ingestion on rat gastric morphology and cell turnover was studied. Misoprostol in a daily dose of 90 micrograms/kg or 9,000 micrograms/kg was intragastrically administered to rats. Control rats were treated with the vehicle only. Following 90 days of treatment, 3H thymidine was injected i.v. and rats were sacrificed 1 h later. Tissue sections were prepared from the stomach body and subjected to autoradiography. Misoprostol treatment significantly reduced body weight gain. High dose misoprostol treatment induced significant increases in gastric wall thickness and in gastric gland length. On the other hand, the labelling index was significantly reduced by treatment with high dose misoprostol. These results indicate that chronic administration of misoprostol in high doses increases gastric wall thickness and decreases gastric cell turnover, suggesting that administration of prostanoids causes an increase in cell survival and a decrease in cell shedding.

Alprostadil↗
PubMed1988

Seasonal variations in the frequency of endoscopically diagnosed duodenal ulcer in Israel.

The seasonal pattern of endoscopically diagnosed duodenal ulcer disease in a representative Israeli medical center was evaluated retrospectively for the period 1980-1986. We reviewed all 9861 endoscopy records and found 1692 duodenal ulcers. We calculated the percentage of duodenal ulcers of the total examinations performed each month. In Israel, the frequency of duodenal ulcers was significantly increased during January and February and was significantly lower during the months May-June and July-August when compared to the rest of the year.

Duodenal Ulcer↗
PubMed1988

No correlation between indomethacin-induced gastroduodenal damage and inhibition of gastric prostanoid synthesis.

The effect of 1 week of treatment with indomethacin 150 mg/day on human gastric prostanoid synthesis was correlated with its effect on gastric and duodenal mucosa. Before and following 1 week of treatment, endoscopic appearance of the mucosa was evaluated and scored. Following 1 week of treatment with indomethacin, antral PGE2 and 6-keto-PGF1 alpha were significantly lower than in normal subjects, but similar in patients with significant or with no mucosal damage. Co-treatment with ranitidine 150 mg b.d. or with cimetidine 400 mg b.d. reduced the mean mucosal damage score but did not affect gastric prostanoid synthesis, which was similar irrespective of the presence or absence of mucosal damage. It is therefore suggested that there is no correlation between indomethacin-induced inhibition of gastric prostanoid synthesis and its induction of mucosal damage.

Adolescent↗
PubMed1988

Cimetidine decreases indomethacin induced duodenal mucosal damage in patients with acute musculoskeletal disorders.

The effect of two doses of cimetidine, 400 mg at night and 400 mg bd, on the protection of indomethacin (50 mg tid) induced mucosal damage was evaluated in a double blind study in patients with acute musculoskeletal disorders. Endoscopic mucosal lesions were scored before and after five to seven days of treatment. One hundred and ninety one patients were endoscoped before the trial, 34 (17.8%) had greater than one erosion and were not recruited. Forty patients were excluded for non-compliance, or lost to follow up. At the second endoscopy, oesophageal, and fundic damage was negligible. Gastric and duodenal lesion score in patients treated with cimetidine 400 mg bd: 2.7 (0.5) (SE); n = 42) was significantly lower (p less than 0.0122) than in placebo treated patients: 6.1 (0.9) (n = 50) or in patients treated with cimetidine 400 mg at night 7.1 (0.8) (n = 21). Cimetidine 400 mg bd provided significant protection for the duodenum, but its protection of antral mucosa did not reach statistical significance. There was no correlation between upper gastrointestinal symptoms and endoscopic findings.

Adolescent↗
PubMed1988

Comparison of misoprostol and ranitidine in the treatment of duodenal ulcer.

The efficacy of misoprostol (a synthetic analogue of prostaglandin E1) and ranitidine in the treatment of duodenal ulcer was evaluated. Seventy-one patients with endoscopically proven duodenal ulcer were randomized in a double-blind manner in one of two groups that received two daily doses of 400 micrograms misoprostol or 150 mg ranitidine. Ulcer healing was assessed endoscopically after 4 weeks of treatment; in subjects who had not healed treatment was continued and endoscopy was repeated after another 4 weeks. The mean age, sex distribution and tobacco, alcohol and caffein consumption were similar in both groups. In the misoprostol-treated group, healing of the ulcer was observed in 74.8% of patients at 4 weeks and in 86.5% at 8 weeks; in the ranitidine group (n = 34), the healing rate was 91.2 and 100%, respectively. The differences between healing rates in the two groups were not statistically significant. In the misoprostol group (n = 37), 27% of patients experienced diarrhea; of these, two were withdrawn from the trial due to this side effect. These results, which are part of a multicenter international study, suggest that misoprostol at a daily dose of 800 micrograms is as effective as 300 mg/day ranitidine in the treatment of duodenal ulcer.

Adult↗