The inositol trisphosphate receptor regulates a 50-second behavioral rhythm in C. elegans.

The C. elegans defecation cycle is characterized by the contraction of three distinct sets of muscles every 50 s. Our data indicate that this cycle is regulated by periodic calcium release mediated by the inositol trisphosphate receptor (IP3 receptor). Mutations in the IP3 receptor slow down or eliminate the cycle, while overexpression speeds up the cycle. The IP3 receptor controls these periodic muscle contractions nonautonomously from the intestine. In the intestinal cells, calcium levels oscillate with the same period as the defecation cycle and peak calcium levels immediately precede the first muscle contraction. Mutations in the IP3 receptor slow or eliminate these calcium oscillations. Thus, the IP3 receptor is an essential component of the timekeeper for this cycle and represents a novel mechanism for the control of behavioral rhythms.

Pepsin concentration in gastroduodenal biopsy homogenates in chronic ulcer disease.

A modification of Berstad's spectrophotometric method was tested and proved capable of detecting pepsin concentrations in mucosal perendoscopic biopsy homogenates. The relationship between this parameter and pepsin in gastric juice and pepsinogen group I in serum and in biopsy homogenates was analyzed. From the biochemical point of view, the assay was found sufficiently accurate. Mucosal pepsinogen group I, but not mucosal pepsin, concentration was found higher in gastric and duodenal ulcer patients than in controls. Patients with corpus-fundic gastric ulcer showed significantly lower mucosal pepsin and mucosal pepsinogen group (PG) I. Aging and smoking did not influence either parameter but male duodenal ulcer subjects presented higher mucosal pepsinogen group I concentration. The lack of any relationship between serum and mucosal PG I and between pepsin in gastric juice and in mucosa raises a question, at least in methodological terms, about the validity of using serum pepsinogen group I and pepsin as indicators of peptic output.

Peptic ulcer in the elderly--a double-blind, short-term study comparing nizatidine 300 mg with ranitidine 300 mg. GISU (Interdisciplinary Ulcer Study Group).

UNLABELLED: This was a randomized, double-blind, multicentre, short-term study comparing ranitidine and nizatidine at the standard dosages of 300 mg at bedtime. In 49 centres in Italy, all peptic ulcer patients aged over 65 years and with endoscopically documented acute disease were considered eligible for the study. Clinical check-ups were repeated every 3 weeks, while the endoscopic and biochemical assessments were scheduled at 6 and (in unhealed patients) 12 weeks. STATISTICS: chi-squared test, Fisher's exact test, Student t-test for unpaired data. The study included 170 duodenal ulcer and 75 gastric ulcer patients. Of these, 83/170 duodenal ulcer and 38/75 gastric ulcer patients were treated with nizatidine 300 mg and the remainder with ranitidine 300 mg. The groups were well-matched for common clinical data. Eight patients dropped out. Healing rates at 6 and 12 weeks were 81.9% and 91.5% for nizatidine-treated duodenal ulcer patients versus 78.1% and 94.2% for ranitidine-treated duodenal ulcer cases (P: N.S.); 6 and 12-week healing rates were 76.3% and 89.5% for nizatidine-treated gastric ulcer patients versus 67.6% and 83.8% for ranitidine-treated gastric ulcer patients (P: N.S.). No slow healing risk factors were found. Only minor adverse events were registered. IN CONCLUSION: ranitidine 300 mg and nizatidine 300 mg both proved effective and safe in the treatment of acute peptic ulceration in the elderly.

Gastric bicarbonate secretion in high-relapsing, smoking duodenal ulcer patients.

Gastric bicarbonate secretion has been evaluated by Feldman's method in 48 duodenal-ulcer patients. The relationship between smoking, clinical ulcer outcome (healing and recurrence) and bicarbonate secretion has been analysed. Heavy smokers secreted higher bicarbonate ions than did non-smokers. High-relapsing patients produced lower bicarbonate output. These preliminary data suggest that an impaired gastric bicarbonate secretion is associated with smoking, a well-known ulcer-associated factor; further-more, it may single out high-relapsing duodenal ulcer patients.

Esaprazole effect on acid, peptic and alkaline secretion in duodenal ulcer patients.

To study the effect of Esaprazole, a new antiulcer drug, on acid, peptic and alkaline secretion a modified gastric acid test was performed in 18 duodenal ulcer patients. Pentagastrin was administered as bolus 30' and 75' after the beginning of the test, followed by Esaprazole 300 mg i.v. at 90'. Gastric juice was collected every 15' for determination of: total volume, volume of non parietal secretion, acid, bicarbonate and pepsin output. Serum pepsinogen group I was determined by radioimmunoassay. Esaprazole had a significant inhibitory effect on the total volume of gastric secretion and on volume of non parietal secretion. Pepsin output and serum pepsinogen group I were not affected by Esaprazole, while bicarbonate secretion was reduced. Antiulcer activity of Esaprazole seems to be due to the reduction of total volume of gastric secretion.

Oesophagitis and pH of refluxate: an experimental and clinical study.

This experimental and clinical study examined the relationship between oesophageal damage and optimal pH of refluxate, and whether 24-h pH monitoring at optimal pH could discriminate the severity of oesophagitis. The rabbit oesophagus was perfused in vivo with pepsin and hydrochloric acid solutions of differing pH for 60 min. Maximal oesophageal damage coincided with peptic solutions at pH 1.5-2.5. Fifty-nine patients with proven gastro-oesophageal reflux disorders were tested for manometric features of the lower oesophageal sphincter (pressure, overall length and abdominal length) and oesophageal exposure to different pH levels. They were classified into four groups according to the endoscopically demonstrated severity of oesophagitis. Supine exposure at the optimal pH level for pepsin activity (pH 1.5-2.5) and overall sphincter length were found to discriminate the severity of oesophagitis reliably in 75 per cent of cases.

[Is there a role for double-contrast radiology in the characterization of patients with non-ulcer dyspepsia?]. / Esiste un ruolo per l'esame radiologico a doppio contrasto nella caratterizzazione di pazienti con dispepsia non ulcerosa?

Nun-ulcer dyspepsia (NUD) is a very common disorder: about 30% of subjects may suffer from this syndrome, with a subsequent increase in sanitary cost. NUD is diagnosed by means of both an accurate anamnesis and instrumental investigations like double-contrast upper gastrointestinal X-rays, endoscopy, and US of the biliary tract. Our study was aimed at evaluating the actual capabilities of double-contrast radiology in the characterization of NUD patients. One-hundred consecutive outpatients (53 males and 47 females, age range 15-84 years) with clinical symptoms of NUD were submitted to double-contrast gastric radiological examination. X-rays were performed without pharmacological hypotonicity to better depict functional disorders (i.e., impaired esophageal motility, gastroesophageal and duodenogastric reflux, gastric hypotonicity, and delayed gastric emptying) even though this prevented the though evaluation of morphological features, which are better identified by gastrointestinal endoscopy. 42% of patients, especially middle-aged ones, exhibited only functional disorders. Double-contrast X-rays might therefore be suggested as a useful investigation technique in young patients with clinical symptoms of NUD: it is capable of showing functional disorders and therefore can support upper gastrointestinal tract endoscopy in the pathophysiological characterization of NUD patients.

[Gastrin tissue levels in patients with peptic ulcer: a different methodological approach]. / Livelli tessutali di gastrina in pazienti con malattia ulcerosa: un diverso approccio metodologico.

The function of G cells has been mainly evaluated by serum gastrin. A different analytical approach considers the direct determination of gastrin levels (ng/g of wet tissue) in perendoscopic biopsies, but, up to now, the results are contradictory. In the present study we evaluated, by means of a RIA method, the concentration of gastrin (ng/g of protein nitrogen) in homogenized gastroduodenal biopsies in 127 patients with peptic ulcer and in 12 dyspeptic patients. The results demonstrated: 1) a significant gradient of gastrin concentrations among the different anatomical sites, according to the distribution of the G cells; 2) a correlation with serum gastrin levels; 3) a good equivalence of gastrin content in adjacent biopsy specimens. This preliminary report indicates that it is possible directly quantitate tissue levels of gastrin by means of an accurate and simple method.

Measurement of pepsinogen group I in endoscopic gastroduodenal biopsies.

A technique for determining pepsinogen group I (PGI) concentrations in endoscopic gastroduodenal biopsies is described and validated. This method has a good precision (intra-assay CVs 4.1% to 8.4%; between-assay CVs 4.6% to 9.3%), and analytical recovery is satisfactory (94% to 102%). Results were uninfluenced by the storage interval of the samples. At PGI-producing sites (i.e., fundus, corpus) peptic activity was greater than in the antrum and duodenum. PGI concentrations in serum and in gastroduodenal biopsies were not correlated. This simple, reliable method can quantify better than other assays peptic activity in humans, without being influenced by gastric secretory volumes. It will also facilitate prospective studies on the effect of various secretagogues in vivo and evaluations of the influence of anti-ulcer drugs on peptic secretion.

[Does Helicobacter pylori have a direct proteolytic effect in ulcerative disease?]. / L'Helicobacter pylori esercita un'azione proteolitica diretta in corso di malattia ulcerosa?

Helicobacter pylori (H.p.), has been shown, experimentally, to exert a proteolytic activity against mucous fractions. Aim of this study was to assess the prevalence of H.p. in peptic ulcer and to analyze its possible influence on gastric mucus components, on peptic activity in gastric juice and the possible action on peptic secretion. 223 patients undergoing upper gastrointestinal endoscopy were analyzed for the presence of H.p. in the mucosa: 99 duodenal ulcer patients (D.U.), 58 gastric ulcer patients (D.U.) and 66 dyspeptic subjects. In each patients, three contiguous gastric biopsies were taken at the antrum: the first was evaluated for gastritis (Whitehead Criteria), the two other analyzed for H.p. with a rapid urease test. In a subgroup of 25 D.U. and 18 G.U. patients, two other biopsies were taken at the fundus corpus of the stomach, to evaluate peptic secretion. To determinate mucous components (acid and neutral glycoproteins, galactose and N-acetylneuraminic acid), gastric juice samples were collected during endoscopy. H.p. was present in 89% of antral biopsies in D.U., in 56% of G.U. and in 51% of D., and was associated to antral gastritis. As regard gastric juice components, we observed an increase and a decrease of acid glycoproteins, respectively, in D.U. and G.U. patients with H.p. infection. An increase of peptic activity has been found in the gastric juice of both gastric and duodenal ulcer patients H.p. positive (G.U. p less than 0.05). On the contrary, no significant differences were observed on peptic activity in the fundus-corpus biopsies between H.p. positive and H.p. negative patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effects of nizatidine and misoprostol on peptic activity and gastric mucus]. / Effetto della nizatidina e del misoprostol sull'attività peptica e sul muco gastrico soluto.

The effects of Nizatidine, an H2-receptor antagonist, and Misoprostol, a PGE1 analogue, on gastric pH, pepsin, pepsinogen group I and N-acetylneuraminic acid concentration were evaluated in a group of 20 patients with duodenal ulcer. Nizatidine decreased pepsin concentration while it increased gastric pH, although not to a significant degree and left pepsinogen group I and N-acetylneuraminic acid concentration unchanged. Misoprostol did not modify gastric pH, pepsin and N-acetylneuraminic acid values but it increased pepsinogen group I levels. These data support the view that H2-receptor antagonists, especially Nizatidine, and Misoprostol do not directly affect pepsin and/or N-acetylneuraminic acid concentration.

[Methodological aspects of gastric acid examination]. / Aspetti metodologici del sondaggio gastrico.

The aim of the present work was to study gastric acid secretion in control subjects and in gastric and duodenal ulcer patients and to evaluate sex, age, body weight, blood group, cigarette smoking and the intake of H2-blockers in the 24 hours preceding gastric acid analysis. The results obtained seem to indicate that 6 micrograms/kg b.w./i.m. Pentagastrin is the best stimulus and that basal secretion may be assessed in thirty minutes, without altering the BAO value. Factors such as cigarette-smoking and H2-blockers intake on the one hand and body weight and male sex on the other influence gastric juice output and should therefore be considered in interpreting the results.