High detection rate of adenomas in familial colorectal cancer.

BACKGROUND AND AIMS: Subjects with one first-degree relative (FDR) with colorectal cancer (CRC) <50 years old or two FDRs with CRC have an increased risk for CRC (RR 4-6). Current guidelines recommend colonoscopic surveillance of such families. However, information about the yield of surveillance is limited. The aim of the present study was to evaluate the outcome of surveillance and to identify risk factors for the development of adenomas. PATIENTS AND METHODS: Subjects were included if they fulfilled the following criteria: asymptomatic subjects aged between 45 and 65 years, with one FDR with CRC <50 years old (group A) or two FDRs with CRC diagnosed at any age (group B). Subjects with a personal history of inflammatory bowel disease or colorectal surgery were excluded. RESULTS: A total of 551 subjects (242 male) met the selection criteria. Ninety-five subjects with a previous colonoscopy were excluded. Two of 456 remaining subjects (0.4%) were found to have a colorectal tumour (one CRC and one carcinoid). Adenomas were detected in 85 (18.6%) and adenomas with advanced pathology in 37 subjects (8.1%). 30 subjects (6.6%) had multiple (>1) adenomas. Men were more often found to have an adenoma than women (24% vs 14.3%; p=0.01). Adenomas were more frequent in group B compared with group A (22.0% vs 15.6%; p=0.09). CONCLUSION: The yield of colonoscopic surveillance in familial CRC is substantially higher than the yield of screening reported for the general population.

Basal serum gastrin concentrations before and after eradication of Helicobacter pylori infection measured by sequence specific radioimmunoassays.

BACKGROUND: Helicobacter pylori infection of the antral mucosa is responsible for an increase in basal and stimulated serum gastrin. In the present study we have investigated whether gastritis induced by H. pylori is responsible for abnormalities in the processing of gastrin in dyspeptic patients. METHODS: Basal serum gastrin was measured by radioimmunoassay before, 5 weeks, and 1 year after anti-H. pylori therapy in 73 H. pylori positive functional dyspeptic patients. Three region-specific antisera were used, specific for the biologically active carboxy-terminal part, the biologically inactive amino-terminal part of gastrin 1-17, and for the non-sulphated tyrosyl residue in gastrin 1-17. RESULTS: Basal serum gastrin levels were markedly (P < 0.01) decreased 5 weeks and 1 year after successful eradication of H. pylori (n = 39) but not in the patients in whom treatment failed (n = 34). A decline of gastrin was observed for each of the three radioimmunoassays. CONCLUSION: The decrease of serum gastrin levels in all three radioimmunoassays after a successful eradication of H. pylori does not point to major changes in the processing of gastrin. These results suggest that G-cells in the antral mucosa are not functionally affected by the inflammation.

Loxiglumide inhibits cholecystokinin stimulated somatostatin secretion and simultaneously enhances gastric acid secretion in humans.

In vitro studies have demonstrated that cholecystokinin releases somatostatin from the gastric mucosa. To date, there is no information about the in vivo significance of this finding in man. Therefore, we have studied the effect of infusion of cholecystokinin resulting in plasma concentrations within the range found after meal-stimulation, on somatostatin release and on gastric acid secretion. In addition we have studied these functions during infusion of the type A cholecystokinin receptor antagonist loxiglumide. In eight healthy subjects, basal gastric acid secretion was distinctly stimulated by cholecystokinin. The effect of cholecystokinin on gastric acid secretion was markedly enhanced by loxiglumide. Cholecystokinin also significantly stimulated somatostatin output into the gastric lumen, but not into the systemic circulation. Somatostatin output into the gastric lumen during infusion of cholecystokinin was abolished by loxiglumide. The data indicate that on the one hand circulating cholecystokinin, like gastrin, stimulates gastric acid secretion probably by binding to less specific type B receptors on parietal cells that are not blocked by loxiglumide, but on the other hand that cholecystokinin, in contrast to gastrin, also inhibits gastric acid secretion probably by binding to specific type A receptors present on somatostatin producing D-cells in the gastric mucosa, that are blocked by loxiglumide.

Two sisters with coeliac disease and jejunal cancer: just a coincidence?

Two sisters with asymptomatic coeliac disease are described; they both developed a primary jejunal cancer at the same age. While screening the family, a third sister was found to have coeliac disease, but without detectable cancer in the small intestine or stomach. These findings suggest an increased susceptibility in this family for carcinoma developing secondary to asymptomatic coeliac disease. We conclude that the finding in a patient of the combination of coeliac disease and malignancy in the digestive tract is sufficient reason to investigate the first-degree relatives with regard to the presence of coeliac disease and a secondary carcinoma.

Effects of Helicobacter pylori infection on endocrine and exocrine mucosal functions in the upper gastrointestinal tract.

BACKGROUND: Helicobacter pylori infection affects the concentration of regulatory peptides such as gastrin, somatostatin and cholecystokinin and the concentration and activity of glutathione and glutathione S-transferases in the gastric mucosa. METHODS: Literature review. RESULTS: Although some of these peptides have been known since the beginning of this century, their action has changed since the discovery of H. pylori infection in 1983. Chronic infection with H. pylori might lead to an increased risk in developing gastric cancer. Glutathione S-transferases are involved in the cellular detoxification of xenobiotics and other toxic compounds. Since there is a close inverse relationship between the activity of glutathione S-transferase and incidence of malignancies in the gastrointestinal tract, the possible relation between H. pylori infection and activity of glutathione S-transferases in the gastric mucosa is discussed. CONCLUSION: The effect of H. pylori infection on regulatory peptides and glutathione/glutathione S-transferases might play a role in the development of neoplastic changes of the H. pylori-infected gastric mucosa.

Eradication of Helicobacter pylori infection in patients with non-ulcer dyspepsia. Effects on basal and bombesin-stimulated serum gastrin and gastric acid secretion.

BACKGROUND: This study evaluates the effect of eradicating Helicobacter pylori on basal and bombesin-stimulated gastric acid secretion and serum gastrin in non-ulcer dyspepsia. METHODS: Before and 1 month after an attempt to eradicate H. pylori basal and bombesin-stimulated gastric acid outputs were measured in 23 patients. H. pylori was eradicated in 15 patients (group A) but not in the other 8 (group B). Incremental gastric acid output was calculated by subtracting basal from bombesin-stimulated values. RESULTS: Basal acid output increased significantly (p = 0.01) after therapy in group A (delta 1.6 +/- 0.6 mmol/h) but not in group B (delta 0.2 +/- 0.5 mmol/h). Incremental gastric acid output decreased distinctly (delta-3.9 +/- 1.4 mmol/h) after therapy in group A (p = 0.02) but not in group B (delta-2.2 +/- 1.7 mmol/h). Basal serum gastrin decreased significantly (p < 0.005) after therapy in group A (delta-9 +/- 4 pM) but not in group B (delta-1 +/- 2 pM). Integrated serum gastrin responses to bombesin decreased markedly (p < 0.001) after therapy in group A (delta-5.0 +/- 1.6 nM*60 min) but slightly in group B (delta-0.9 +/- 1.3 nM*60 min) (p < 0.05). CONCLUSIONS: In patients with non-ulcer dyspepsia basal serum gastrin concentrations decrease but basal gastric acid outputs increase after eradication of H. pylori. Bombesin-induced increments in gastric acid output, however, decrease in parallel with gastrin release.

Antral glutathione concentration and glutathione S-transferase activity in patients with and without Helicobacter pylori.

Previously we demonstrated an inverse relation between cancer of the gastrointestinal tract and glutathione S-transferase activity of the gastrointestinal mucosa. Chronic infection with H. pylori has been associated with an increased risk of gastric cancer. The aim of this study was to investigate the levels of glutathione and glutathione S-transferase activity in H. pylori-infected and noninfected antral mucosa. Glutathione and glutathione S-transferases were measured in antral biopsies of patients with nonulcer dyspepsia without H. pylori infection (A), with prior H. pylori infection who became H. pylori negative after eradication therapy (B) and with proven H. pylori infection (C). Glutathione concentration and glutathione S-transferase activity in group A were 31.0 (range 6.0-59.6) nmol/mg protein and 810 (range 165-1312) nmol/min/mg protein, in group B 27.0 (range 5.0-53.8) nmol/mg protein and 745 (range 403-1199) nmol/min/mg protein, and in group C 18.5 (range 1.6-55.8) nmol/mg protein and 572 (range 144-1047) nmol/min/mg protein, respectively. The glutathione and glutathione S-transferase values were significantly lower in patients infected with H. pylori than in patients who were H. pylori negative.

Eradication of Helicobacter pylori restores glutathione S-transferase activity and glutathione levels in antral mucosa.

Glutathione S-transferases (GST) and glutathione peroxidases (GPO) are important in detoxification. GST activity in the mucosa of the gastrointestinal tract is inversely correlated with the development of gastrointestinal cancer. Helicobacter pylori (H. pylori) infection has been associated with gastric cancer. We studied GST activity and the substrate glutathione (GSH) in patients with H. pylori-associated gastritis. GST activity and isoenzyme levels, GPO activity and GSH levels were studied in antral biopsies of 38 H. pylori-positive patients, before and after eradication treatment. In 31 patients in whom H. pylori was successfully eradicated, antral GST enzyme activity before therapy was 532 (465 - 598) nmol / mg protein. min (mean and 95% confidence interval) and that after therapy was 759 (682 - 836) nmol / mg protein. min (P < 0.0001). Correspondingly, levels of GST alpha and GST-P1 were higher after eradication (P < 0.001). GSH concentration significantly increased: 21.2 (16.2 - 26.2) nmol / mg protein before and 27.1 (23.6 - 30.6) nmol / mg protein after therapy (P < 0.05). In 7 patients in whom H. pylori was not eradicated, GST activity was 671 (520 - 823) nmol / mg protein. min and 599 (348 - 850) nmol / mg protein before and after treatment respectively (P = 0.32). GSH levels were 17.4 (9.0 - 25.7) nmol / mg protein and 18.2 (9.1 - 27.3) nmol / mg protein, respectively (P = 0.84). No differences in antral GPO enzyme activity, both of selenium (Se)-dependent and total GPO, before and after successful treatment were found. Eradication of H. pylori infection increases GST activity and GSH levels in antral mucosa. Low GST activity and GSH concentration due to H. pylori infection might play a role in gastric carcinogenesis.