Samples Of Fasting Gastric Juice Research Articles

Bile acids in laryngopharyngeal refluxate: Will they enhance or attenuate the action of pepsin?

To assess if, as previously reported in the literature, bile acids inhibit pepsin activity, resulting in pepsin having a less important role in laryngopharyngeal damage in reflux disease. Prospective translational research study. A total of 78 patient's fasting gastric juice samples were obtained from routine endoscopy. The total bile acid (TBA) content and pepsin activity were measured using a 3α-hydroxysteroid dehydrogenase-based kit for bile acids; and pepsin activity was measured using succinyl albumin/dimethylhaemoglobin as a substrate and the development of new N-terminals. The ability of bile acids to effect pepsin activity was assessed with three primary bile acids, two unconjugated and one taurine conjugated, using the above N-terminal assay. Gastric juice contained median TBA of 40 (range 10-10010) μM and pepsin activity of 408 (range 27-3892)ug/ml. We used this data to inform the relative levels of pepsin and bile acids that might occur in a reflux event, and we used concentrations of bile acids between 10-100μM. Pepsin activity was pH dependent, but 28% of the activity was retained at pH 5.5. None of the bile acids showed any significant effect on pepsin activity across the pH range 2.0-6.0. At the levels and pH that pepsin and bile acids might occur in an LPR event, bile acids do not attenuate pepsin activity. Pepsin could be considered a damaging factor even at high pH, and it will aggravate further any damaging effects of bile acids in the refluxate. Laryngoscope, 2012.

Helicobacter pylori does not release cysteamine into gastric juice.

AIM: To determine whether Helicobacter pylori releases cysteamine into gastric juice as cysteamine is known to be ulcerogenic. METHODS: Samples of fasting gastric juice were collected from 22 individuals (four...

Increased expression of p62pan-myc in gastric pylori mucosa biopsies from subjects exposed to N-nitrosamides

To elucidate the possible role of myc oncogene in human gastric carcinogenesis byN-nitrosamides Methods: Expression of pan-myc in gastric biopsies of pylori and concentration of totalN-nitrosamides in fasting gastric juice samples were studied simultaneously with immunochemohistological method and liquid mobile-photohydrolysis-pyrolysis energy analyzer. Results: Ofgastric juice samples, 57. 1 % were N-nitrosamide-detectable. Evaluation of p62pan-myc in mucosal epithelial cells Was found in 6 gastric biopsies. All the 6 p62pan-myc-positive biopsies were from patients whosegastric juices were N-nitrosamide-detectable, whereas no p62 pan-myc-positive biopsy was found inthose from 15 cases whose gastric juices were N-nitrosamide-undetectab1e (P= 0. 0239). Such relationwas not observed for p21pan-ras, p185c-erbB-2, and p53mutant p53. Conclusion: These results indicate firstlythat expression of myc oncogene correlated with the exposure to N-nitrosamides in human stomach positively and myc oncogene may play a role in the early stage of human gastric carcinogenesis by N-nitrosamides.

N-nitroso compounds, nitrite and pH in human fasting gastric juice.

Total N-nitroso compounds, ethyl acetate-extractable N-nitroso compounds and nitrite were measured in 146 samples of fasting gastric juice to investigate their relationship with pH. A positive correlation was found between pH and extractable N-nitroso compounds (r = 0.206, P < 0.02), whereas total N-nitroso compounds were pH-independent. It was inferred that pre-cancerous conditions associated with high gastric pH may be produced by an increase in the extractable N-nitroso compounds, which constitute only a small fraction of the total gastric N-nitroso compounds.

Spontaneous Bile Reflux in the Elderly

Duodenogastric bile reflux is common in postoperative stomach but has been reported in intact stomachs. Spontaneous bile reflux in the elderly has not been studied before. This has been assessed in dyspeptic elderly and young patients. Total bile acid (TBA) levels and pH were measured in the samples of fasting gastric juice. Antral biopsies were taken for histological examination including Helicobacter pylori identification. TBA levels were significantly higher in elderly patients with gastritis in comparison to elderly and young normal groups. Only 10% of elderly patients with gastritis and 7% with gastric ulcer has abnormal TBA (> 1 mmol/l). There was some correlation between the pH and TBA but a significant proportion of elderly patients has pH > 4 with a normal TBA. TBA levels were not significantly different in H. pylori +ve and H. pylori -ve patients. Nineteen elderly patients had evidence of reactive gastritis. Five of these patients had raised TBA levels with severe H. pylori infection. The remaining 15 patients had normal TBA. These patients were on NSAIDs and 4 of them had H. pylori infection. We conclude that spontaneous bile reflux in the elderly is uncommon. Hypochlorhydria which is observed in the elderly is not caused by alkaline bile reflux. The main cause of reactive gastritis in the elderly is NSAIDs ingestion.

N-nitroso compounds in fresh gastric juice and their relation to intragastric pH and nitrite employing an improved analytical method.

In order to examine further the relationship between intragastric N-nitrosation, gastric pH and nitrite, 457 fresh, fasting gastric juice samples were analysed for total N-nitroso compounds (NOC) and nitrite concentrations using a recently described improved assay method. Nitrite in log values was linearly related to intragastric pH (r = 0.887, P < 0.01) with a regression equation log[nitrite] (mumol/l) = 0.489 x pH - 2.209. Significantly higher NOC concentrations were found at intragastric pH ranges of 1.13-2.99 (mean +/- SE: 1.45 +/- 0.17 mumol/l, P < 0.05) and 6.00-8.42 (3.57 +/- 0.33 mumol/l, P < 0.01) compared with that at pH 3.00-5.99 (1.02 +/- 0.12 mumol/l). NOC concentration was significantly related to log nitrite concentration at both the low pH range 1.13-4.99 (r = 0.169, P < 0.01) and the high pH range 5.00-8.42 (r = 0.450, P < 0.01). The results in the present study confirm that both acid-catalysed N-nitrosation and biologically-catalysed N-nitrosation occur in the human stomach. However, great variations in nitrite and NOC concentrations were observed in both low and high pH samples, indicating that, as expected, both the acid-catalysed N-nitrosation and biologically-catalysed N-nitrosation processes are markedly affected by factors other than intragastric pH and nitrite.

Reflux gastritis in the intact stomach.

Gastric biopsy specimens from patients who have undergone gastric surgery frequently exhibit foveolar hyperplasia, oedema, vasodilatation and congestion, and a paucity of inflammatory cells as consequences of entero-gastric reflux. Similar, albeit generally milder, changes were found in 47 of 316 (15%) non-surgical patients undergoing endoscopy for dyspeptic symptoms. To relate these changes to bile reflux or other potential gastric irritants the total bile acid concentration was measured in samples of fasting gastric juice, and the use of a symptom questionnaire ascertained the patients' cigarette consumption, use of non-steroidal anti-inflammatory drugs (NSAIDs), and alcohol intake. When patients with reflux gastritis were compared with normal controls (n = 91), significant increases in associated peptic ulceration and NSAID use were found in the group with reflux, but no increases in bile acid concentrations. Indeed, only one patient had evidence of duodenogastric reflux. It is concluded that most cases of "reflux gastritis" in the intact stomach are not due to reflux of bile. Our findings indicate an important pathogenic role for long term NSAID use, in what might be usefully termed type C or "chemical" gastritis.

Gastritis and Campylobacter pylori

(Continued from p 1901.) To the Editor .—I read with interest the report by Barthel et al 1 in the May 1988 issue of theArchivesconcerning the finding of histologic gastritis associated with Campylobacter pylori in 4 of 20 healthy asymptomatic volunteers. Although they reported the age range and median age, the ages of the 4 subjects positive for gastritis and C pylori infection were not mentioned. Other studies have shown an association with increasing age and prevalence of gastritis and C pylori . The authors also report finding fasting gastric hypochlorhydria in the four C pylori -positive subjects compared with the normal volunteers without gastritis. I do not believe such a state-ment is justified in the context of the methodology employed. Samples of fasting gastric juice were endoscopically obtained and the pH was determined, but we are not told if an appropriate glass hydrogen ion electrode was used or

Studies in gastric carcinogenesis. II. Absence of elevated concentrations of N-nitroso compounds in the gastric juice of Greek hypochlorhydric individuals.

The concentrations of nitrate, nitrite, N-nitroso compounds and bacteria were measured in 96 samples of fasting gastric juice, pH 0.90-8.50, obtained from 56 individuals just before or at various times (8 days - 1 year) after gastric operation. The mean pH of the post-operative samples [4.66 +/- 0.39 (SEM)] was significantly higher than that of the pre-operative ones [3.29 +/- 0.33 (SEM)]. A positive correlation with pH was observed for the concentrations of total and nitrate-reducing bacteria (median values 5.0 X 10(5) organisms/ml and 9.2 X 10(4) organisms/ml, respectively, for samples with pH greater than or equal to 1.2 X 10(3) organisms/ml and 0 organisms/ml, respectively, for samples with pH less than or equal to 2.5) and nitrite [mean values 22.5 +/- 3.1 (SEM) microM and 3.20 +/- 0.5 (SEM) microM for samples with pH greater than or equal to 6.5 and pH less than or equal to 2.5, respectively]. No correlation with pH was seen for the concentrations of nitrate [mean value 0.48 +/- 0.06 (SEM) mM] or N-nitroso compounds [mean value 0.30 +/- 0.06 (SEM) microM]. The concentrations of bacteria and nitrite, although increased in hypochlorhydric individuals, were lower than those reported for corresponding individuals in other, primarily British, studies. It is suggested that the relatively low concentrations of nitrite observed in our hypochlorhydric population may account for the absence of elevated concentrations of N-nitroso compounds and that the latter phenomenon may be related to the relatively low frequency of gastric cancer in Greece.

Nitrite and thiocyanate in the fasting and secreting stomach and in saliva.

The concentrations of nitrite and thiocyanate in fasting and pentagastrin stimulated gastric juice and in saliva have been examined. Nitrite was found in all of 17 samples of fasting gastric juice, mean 4-9 +/- 1-1 muM. Stimulation of gastric secretion with pentagastrin caused no significant change in nitrite concentration. Thiocyanate was detected in all of 21 samples of fasting gastric juice and the difference in concentration between smokers and non-smokers probably reflects similar differences in saliva. In contrast to the nitrite data there was a significant drop in thiocyanate concentration of gastric juice after pentagastrin from 0-9 +/- 0-1 mM to 0-3 +/- 0-04 mM, suggesting a salivary origin for the thiocyanate in gastric juice. Thiocyanate is a powerful catalyst of nitrosation, which, together with small amounts of nitrite and naturally occurring amines could lead to the intragastric formation of carcinogenic nitrosamines and in certain circumstances be a factor in the aetiology of gastric cancer.

Duodenogastric reflux: a cause of gastric mucosal hyperaemia and symptoms after operations for peptic ulceration.

This study has investigated the possible association between duodenogastric reflux, gastritis, and symptoms in 35 patients with or without dyspepsia one to 15 years after gastric surgery. Five patients were excluded because of biliary disease, hiatus hernia, or recurrent ulceration. The remaining 30 were assessed by a symptomatic score, measurement, of bilirubin and sodium concentrations in samples of fasting gastric juice, endoscopy, gastric biopsy, and the presence of radiological reflux. In 15 patients with a symptom score of less than the median, gastric bilirubin levels were less than 1 mg/100 ml in 80%; severe endoscopic changes were seen in only one patient and reflux was not observed. In contrast, in patients with a symptom score in excess of the median fluoroscopic and biochemical reflux was seen in 69 and 80% respectively and severe mucosal hyperaemia in half. There was a significant correlation between symptoms, gastric hyperaemia, and duodenal reflus ( P smaller than 0-02).