Helicobacter pylori and atrophic gastritis: importance of the cagA status.

BACKGROUND: Infection with Helicobacter pylori is a major risk factor for the development of atrophic gastritis and gastric cancer. H. pylori strains can differ with respect to the presence of cagA (cytotoxin-associated gene A), a gene encoding a high-molecular-weight immunodominant antigen. H. pylori strains possessing cagA have been associated with enhanced induction of acute gastric inflammation. PURPOSE: We investigated the relationship between cagA status and the development of atrophic gastritis in a cohort of subjects infected with H. pylori. METHODS: Gastrointestinal endoscopy with biopsy sampling was used to study the natural history of gastritis in 58 subjects infected with H. pylori. Biopsy specimens were obtained before and after a mean follow-up period of 11.5 years (range, 10-13 years). The cagA status of each individual was determined at the follow-up visit with the use of an enzyme-linked immunosorbent assay designed to detect the presence of serum immunoglobulin G directed against the CagA protein. Two-sided Fisher's exact tests, McNemar's tests, Student's t tests, and Wilcoxon sum rank tests were used to analyze the data. RESULTS: Twenty-four (41%) of the 58 evaluated subjects had serum antibodies against CagA (i.e., they were cagA positive), and 34 subjects were cagA negative. At the initial visit, moderate to severe atrophic gastritis was observed in eight (33%) of the cagA-positive subjects and in six (18%) of the cagA-negative subjects. At that time, positive cagA status and gastric atrophy were not significantly related (P = .22; Fisher's exact test; odds ratio [OR] 2.33; 95% confidence interval [CI] = 0.58-9.65). During follow-up, 16 (36%) of the 44 initially atrophy-negative subjects developed atrophic gastritis (eight [50%] of 16 cagA-positive subjects versus eight [29%] of 28 cagA-negative subjects; P = .20, Fisher's exact test; relative risk [RR] = 1.75; 95% CI = 0.82-3.76). In six of these 16 subjects (five cagA positive versus one cagA negative), atrophic gastritis was accompanied by the development of intestinal metaplasia (i.e., a change in the type of specialized cells present) (P = .02; Fisher's exact test; RR = 9.06; 95% CI = 1.16-71.0). One of the initially atrophy-negative, cagA-positive subjects developed early gastric cancer. Four (29%) of the 14 subjects initially diagnosed with atrophic gastritis showed regression of atrophy during follow-up (one cagA positive and three cagA negative). Therefore, at the end of follow-up, 15 (62%) of the 24 cagA-positive subjects had atrophic gastritis compared with 11 (32%) of the 34 cagA-negative subjects (P = .02; Fisher's exact test; OR = 3.48; 95% CI = 1.02-12.18). CONCLUSION: Infection with cagA-positive H. pylori strains is associated with an increased risk for the eventual development of atrophic gastritis and intestinal metaplasia.

Localization of pepsinogen (A and C) and cellular differentiation of pepsinogen-synthesizing cells in the human gastric mucosa.

The localization of pepsinogens (PG A and PG C) was studied intracellularly in human gastric biopsies embedded in Lowicryl K4M, using affinity-purified antibodies and protein A-gold. The homogeneous secretory granules of the chief cells contained both PG A and PG C, as was proved by serial sections. Identical reaction was also seen in the core of the biphasic mucous neck cell granules, whereas the mantle did not label. The rough endoplasmic reticulum (RER) and Golgi complex of the chief cells and mucous neck cells contained ample label. Transitional cells identified by the presence of granules of both chief cells and mucous neck cells were recognized. This type of mucous neck cell is thought to transform into a chief cell. However, an increase of RER that could explain an increase of the pepsinogen production was not observed. A mixture of these granules was also found in cells morphologically characterized as young parietal cells, suggesting a common precursor for these three cell types. These observations make the transformation from mucous neck to chief cells questionable. Antral gland cells contained only PG C, as was shown in serial section, too.

Identification of a Glu greater than Lys substitution in the activation segment of human pepsinogen A-3 and -5 isozymogens by peptide mapping using endoproteinase Lys-C.

The isozymogens PGA-3 and PGA-5 of human pepsinogen A were digested with endoproteinase Lys-C. The peptides were separated by reverse-phase HPLC. PGA-5 showed a peak strongly absorbing at 254 nm absent in PGA-3. Analysis of amino acid composition using the Pico-Tag methodology combined with DABITC-sequencing reveals the sequence Tyr-Phe-Pro-Gln-Trp-Lys (peptide 37-43 of the activation segment). This confirms a study at the DNA level by our group [16] suggesting a Glu greater than Lys mutation at position 43 in the activation segment of PGA-5. Furthermore, it is proposed that the number of genetic variants of PGA is higher than is actually seen by electrophoresis.

Serum anti-Helicobacter pylori IgG antibodies and pepsinogens A and C as serological markers of chronic atrophic gastritis.

This study was designed to test the sensitivity and specificity of serum anti-Helicobacter pylori IgG antibodies and the ratio of serum pepsinogen A to pepsinogen C (PGA:PGC) in detecting chronic atrophic gastritis (CAG) and intestinal metaplasia. Parallel gastric biopsies and a serum sample were collected from a series of 87 patients aged 20-69 years attending a routine upper endoscopy clinic. The seroprevalence (> 10 micrograms IgG/ml) of anti-H. pylori antibodies was 42.7%, and of a low PGA:PGC ratio (< 1.5) was 17.7%. A positive H. pylori IgG antibody level was more sensitive than the level of PGA:PGC in diagnosing CAG (71.4% and 25.0%, respectively), moderate CAG (86.7% and 26.7%, respectively), and intestinal metaplasia (90.9% and 50.0%, respectively). Anti-H. pylori IgG antibody levels were less specific than PGA:PGC levels in diagnosing CAG (90.9% and 93.9%, respectively), moderate CAG (78.3% and 89.1%, respectively), and intestinal metaplasia (72.6% and 92.2%, respectively). A combination of anti-H. pylori antibodies and a low PGA:PGC ratio for the detection of CAG resulted in a specificity of 100%, but the sensitivity was 21.4%.

Selective gene delivery toward gastric and esophageal adenocarcinoma cells via EpCAM-targeted adenoviral vectors.

Application of recombinant adenoviral vectors for cancer gene therapy is currently limited due to lack of specificity for tumor cells. For gastric and esophageal adenocarcinoma, we present here that the relative abundant expression of the primary adenovirus receptor, coxsackie/adenovirus receptor (CAR), on normal epithelium compared to carcinoma favors the transduction of the epithelium. As such, to achieve specific transduction of cancer cells, targeting approaches are required that ablate the binding of the virus to CAR and redirect the virus to tumor-specific receptors. By immunohistochemistry and reverse transcriptase polymerase chain reaction assays, we demonstrate a marked difference in expression of the human epithelial cell adhesion molecule (EpCAM) between normal and (pre)malignant lesions of the stomach and esophagus. Based on this, we explored the feasibility of using EpCAM to achieve gastric and esophageal adenocarcinoma selective gene transfer. Adenoviral vectors redirected to EpCAM using bispecific antibodies against the adenovirus fiber-knob protein and EpCAM specifically infected gastric and esophageal cancer cell lines. Using primary human cells, an improved ratio of tumor transduction over normal epithelium transduction was accomplished by the EpCAM-targeted vectors. This study thus indicates that EpCAM-targeted adenoviral vectors may be useful for gastric and esophageal cancer-specific gene therapy in patients.

Pharmacological management of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease (GORD) ranges from episodic symptomatic reflux without oesophagitis to severe oesophageal mucosal damage, such as Barrett's metaplasia or peptic stricture. The multifactorial pathogenesis of GORD prevents medical cure of the disease. GORD is a chronic disease with a high tendency to relapse, requiring a long term treatment strategy in practically all patients. Complete healing of all mucosal lesions is not necessarily the aim of treatment in all patients. In milder forms of reflux disease, symptom relief is the most important goal. Many patients with mild GORD do well on symptomatic self-care with antacids and/or alginate. In addition, lifestyle changes should be advised to all patients: these improve symptoms and enhance the efficacy of therapy. In the acute treatment of GORD the prokinetic drug cisapride has been shown to be effective in relieving symptoms and healing grade I to II oesophagitis. Cisapride decreases symptomatic and endoscopic relapse in patients with mild GORD. Histamine H2-receptor antagonists are effective in relieving reflux symptoms in about 50% of patients, but with regard to healing, H2-antagonists appear to be mainly effective in grades I and II and not in higher grades of oesophagitis. Maintenance treatment with H2-antagonists is mainly symptomatically effective in patients with mild GORD. Proton pump inhibitors (PPIs) provide significantly higher healing rates of reflux oesophagitis than H2-antagonists, even in the more severe cases of oesophagitis and Barrett's ulcers. PPIs are also effective in patients with oesophagitis refractory to treatment with H2-antagonists. PPIs have become the drugs of first choice in healing of all patients with more severe forms of reflux oesophagitis, and increasingly also for patients with milder forms of oesophagitis, certainly those who fail to respond to other drugs. In maintenance treatment of GORD, PPIs are the most effective drugs, offering the possibility of keeping nearly all patients in remission with adjusted doses. Current patient data of up to 5 years indicate the safety of this strategy for this period, but the exact consequences of strong acid inhibition over a longer period still have to be clarified. At present, all but a few patients with GORD can be managed adequately by medical therapy.

Spondyloarthropathy and idiopathic inflammatory bowel diseases.

: Spondyloarthropathy (SpA) as observed in patients with idiopathic inflammatory bowel diseases is categorized according to the recently developed criteria of the European Spondylarthropathy Group, and belongs to a large complex of rheumatic disorders, encompassing ankylosing spondylitis, Reiter's disease, psoriatic arthritis, and reactive arthritis. It has been recognized for many years that patients with ulcerative colitis or Crohn's disease frequently have arthritic complications. The gastroenterologist should therefore carefully evaluate any symptom of peripheral or axial arthritis, in an attempt to provide an accurate diagnosis, to define a realistic prognosis, and to establish adequate therapy at an early stage. In this review, clinical and etiopathogenic aspects are analyzed, not only of patients with inflammatory bowel diseases and SpA, but also of patients developing arthritic symptoms after gastrointestinal bacterial infections (reactive arthritis). The significance of ileal mucosal inflammation as observed frequently in patients with SpA is discussed; the contribution of immunogenetic factors in the development of SpA, such as HLA-B27, is briefly reviewed. Finally, analysis is made of the different therapeutic options that are available at present.

The influence of omeprazole on the synthesis and secretion of pepsinogen in isolated rabbit gastric glands.

Regulation mechanisms of pepsinogen (EC 3.4.23.) synthesis and secretion were studied by following newly synthesized [14C]-labeled pepsinogen during culture of isolated rabbit gastric glands. Omeprazole, a substituted benzimidazole, while almost completely abolishing acid production at 10(-4) M, strongly stimulated secretion of preformed and newly synthesized pepsinogen. Although the pepsinogen synthesis at this concentration of omeprazole was reduced to about 55% of the control rate, a two-fold absolute increase of total secreted pepsinogen was found. This increase was not due to a non specific leakage through disruption of chief cell membranes, as no increase of lactate dehydrogenase in the culture medium could be demonstrated. The stimulated secretion was influenced neither by 10(-3) M cimetidine, 10(-3) sodium thiocyanate nor 10(-4) M atropine. No additivity was found between the carbachol (10(-4) M) or dibutyryl cyclic AMP (10(-3) M) and the omeprazole induced pepsinogen secretion.

Combined gastric and oesophageal 24-hour pH monitoring and oesophageal manometry in patients with reflux disease, resistant to treatment with omeprazole.

Combined oesophageal and gastric 24-hour pH monitoring and oesophageal manometry were performed in 19 patients with resistant reflux oesophagitis after short-term therapy with omeprazole (40 to 60 mg daily) or during maintenance treatment with omeprazole (20 to 80 mg daily). Omeprazole's effects on acidity were analysed as well as any possible influence on oesophageal motility. A pH in the stomach of below 4 was present during considerable periods of time (in 27 of 29 measurements), particularly during the night. As a consequence, pathological gastro-oesophageal reflux occurred, particularly in the supine period. Insufficiency of the lower oesophageal sphincter was present in all but one patient; decreased or virtually absent motility of the oesophagus was found in 63% of the patients. Combined intragastric and intra-oesophageal pH monitoring, with oesophageal manometry, may contribute to the management of patients with reflux disease resistant to treatment with omeprazole. The present study emphasizes the need to individualize therapy in patients with refractory gastrooesophageal reflux disease.

The effects of omeprazole and ranitidine on 24-hour pH in the distal oesophagus of patients with reflux oesophagitis.

Ambulatory 24-h pH monitoring in the distal oesophagus was performed in seven patients with erosive or ulcerative reflux oesophagitis to compare the effects of omeprazole and ranitidine in the management of gastro-oesophageal reflux disease. In a double-blind, crossover study patients were treated with either 60 mg o.m. omeprazole or 150 mg b.d. ranitidine. The pH measurements were performed before treatment and on the fourteenth day of treatment with either regimen. The total acid exposure time (percentage total time pH less than 4) was abnormal in six out of seven patients before treatment. During treatment with omeprazole the acid exposure time of five patients was normal in comparison with only two patients during ranitidine therapy. However, even with a rather high dose of omeprazole, pathological gastro-oesophageal reflux may still occur.

Review article: the development of atrophic gastritis--Helicobacter pylori and the effects of acid suppressive therapy.

Helicobacter pylori is uniquely adapted to survival in the strongly acidic gastric lumen. In vitro, both acid and certain acid suppressors affect bacterial growth. In vivo, there is little evidence that acid suppressors have any effect on bacterial survival. In contrast, decrease of acid secretion quickly leads to a spreading of the bacterial infection throughout the body and fundus of the stomach, which is accompanied by an increase of the associated gastritis. Helicobacter pylori gastritis may, in a substantial number of infected subjects, ultimately lead to atrophy and intestinal metaplasia, conditions with an increased risk for gastric cancer. This review summarizes the data on the interrelation between Helicobacter pylori, gastric acid secretion and development of atrophic gastritis.

Effect of prucalopride, a new enterokinetic agent, on gastrointestinal transit and anorectal function in healthy volunteers.

BACKGROUND: Prucalopride (PR) is a novel 5-HT4 agonist enterokinetic compound. AIM: To evaluate its effect on bowel function, gut transit and anorectal function in healthy volunteers using a double-blind, placebo-controlled crossover study. METHODS: Twenty-four healthy volunteers (12 men, 12 women, mean age 25 years, range 20-53 years) were randomly assigned to 1 mg/placebo or 2 mg/placebo (PL). The trial consisted of five consecutive 1 week periods: no drug treatment, PR treatment or PL, washout, PL or PR, no treatment. Subjects maintained a diary of bowel function during the entire study period. Total intestinal transit time (TITT), mean colonic transit time (MCTT) and anorectal function (anal manometry, rectal sensitivity and rectal compliance) were assessed at the end of both treatment periods. Electrocardiography and blood sampling were performed for safety analysis; blood sampling was also used to check compliance. RESULTS: No subjects withdrew from the study. Treatment with PR 2 mg showed a statistically significant increase in mean number of weekly stools (11.5 vs. 7.1 compared to PL, P = 0.04) and in the percentage of loose/watery stools (48 vs. 12% compared to PL, P = 0.005). Within 1 week, stool frequency and consistency returned to baseline values when treatment was stopped. MCTT was shortened significantly with both doses, i.e. from 35 h on PL to 25 h on PR 1 mg (P = 0.01) and from 43 h on PL to 22 h on PR 2 mg (P = 0.02). Anorectal function was unaffected by PR. Transient and moderate headache occurred in nine subjects during PR treatment and in six subjects during PL treatment. CONCLUSION: Prucalopride is well tolerated by healthy subjects and has a marked and consistent effect on stool frequency and consistency, and on colonic transit. In the present study prucalopride did not affect visceral sensitivity or sphincter function. It holds promise for patients with slow transit constipation.

Effect of short- and long-term treatment with omeprazole on the absorption and serum levels of cobalamin.

AIMS: To evaluate absorption of protein-bound and unbound cyanocobalamin before and during treatment with omeprazole, and cobalamin levels in patients on long-term treatment with omeprazole. METHODS: In eight former duodenal ulcer patients absorption of unbound and protein-bound cobalamin was determined by measuring 24-h urinary excretion of unbound 58Co-cyancobalamin or protein-bound 57Co-cyanocobalamin during a modified Schilling test. Tests were performed before and during treatment with 20 mg and 40 mg omeprazole daily for 9 days. Serum cobalamin levels were assessed in 25 patients with gastro-oesophageal reflux disease (GERD) before and during long-term maintenance therapy with omeprazole. Mean treatment duration was 56 months (range 36-81 months). RESULTS: Urinary excretion of unbound cobalamin was unchanged with both dosages of omeprazole. Excretion of 57Co-cyanocobalamin, however, decreased significantly during treatment with both 20 mg omeprazole (mean +/- S.E.M.: 1.31 +/- 0.20 vs. 0.54 +/- 0.17%; P < 0.02) and 40 mg omeprazole (1.25 +/- 0.26 vs. 0.29 +/- 0.06%; P < 0.02). Mean serum cobalamin levels (+/- S.E.M.) before and during therapy with omeprazole in GERD patients were 298 +/- 27 and 261 +/- 16 pg/mL (normal range 180-900 pg/mL), respectively (P = N.S.). CONCLUSIONS: Absorption of protein-bound, but not unbound, cyanocobalamin is decreased when measured by a modified Schilling test during treatment with omeprazole. However, no change in serum cobalamin levels was observed in patients with GERD after treatment with omeprazole for up to 7 years.

Repeated high oral doses of omeprazole do not affect intrinsic factor secretion: proof of a selective mode of action.

The effect of 60 mg oral omeprazole daily for 9 days on intrinsic factor and gastric acid secretion was studied in eight healthy volunteers. Gastric secretion studies were performed during saline and 0.1 M HCl perfusion before and after omeprazole administration. During dosing with omeprazole, basal gastric acid output diminished by 94%, and pentagastrin-stimulated acid output by 97%. Basal, peak and steady-state stimulated intrinsic factor output were unaffected by omeprazole. It is concluded that high oral doses of omeprazole suppress gastric acid secretion to very low levels but they do not affect intrinsic factor secretion. Intrinsic factor secretion was also unaffected by profound hypochlorhydria.

Effects of prucalopride on colonic transit, anorectal function and bowel habits in patients with chronic constipation.

BACKGROUND: There is a need for better tolerated drugs to normalize bowel function in chronic constipation. Prucalopride is a highly selective, specific, serotonin4 receptor agonist with enterokinetic properties. AIM: To evaluate the effects of prucalopride on bowel function, colonic transit and anorectal function in patients with chronic constipation. METHODS: Twenty-eight patients were enrolled in this double-blind, placebo-controlled, crossover study (prucalopride: 1 mg, n=12; 2 mg, n=16). Patients kept a bowel function diary. Colonic transit times and anorectal function (anal manometry, rectal sensitivity and rectal compliance) were assessed. RESULTS: Prucalopride (1 mg) compared to placebo significantly increased the mean number of spontaneous complete, spontaneous and all bowel movements per week. Prucalopride (1 mg) significantly decreased the percentage of bowel movements with hard/lumpy stools and straining and increased the urge to defecate. Prucalopride (1 and 2 mg) decreased the mean total colonic transit time by 12.0 h (prucalopride 42.8 h vs. placebo 54.8 h; P=0.074). No statistically significant effects were found in any of the anorectal function parameters. Prucalopride was well tolerated. There were no clinically relevant changes in standard safety parameters. CONCLUSIONS: Prucalopride significantly improves stool frequency and consistency, and the urge to defecate, and may decrease colonic transit times in patients with chronic constipation.

Hypergastrinaemia during long-term omeprazole therapy: influences of vagal nerve function, gastric emptying and Helicobacter pylori infection.

AIM: elucidate the mechanisms that lead to severe hypergastrinaemia during long-term omeprazole therapy for gastro-oesophageal reflux disease (GERD). PATIENTS AND METHODS: A total of 26 GERD patients were studied during omeprazole maintenance therapy. Twelve patients with severe hypergastrinaemia (gastrin > 400 ng/L) were compared with 14 control patients (gastrin < 300 ng/L). Helicobacter pylori serology and a laboratory screen were obtained in all patients. Gastric emptying was scored by the evidence of food remnants upon endoscopy 12 h after a standardized meal. Gastric antrum and corpus biopsies were analysed for histological parameters, as well as somatostatin and gastrin concentrations. All patients underwent a meal-stimulated gastrin test and the hypergastrinaemia patients also underwent a vagal nerve integrity assessment by pancreatic polypeptide testing (PPT). RESULTS: Severe hypergastrinaemia patients had a longer duration of treatment (80 vs. 55 months; P = 0.047) and were characterized by a higher prevalence of H. pylori infection (9/12 vs. 2/14, P = 0.004), corpus mucosal inflammation and atrophic gastritis (P < 0.04). This was reflected in lower serum pepsinogen A concentrations (mean +/- S.E.M. 53.6 +/- 17.9 vs. 137 +/- 16.0 mg/L, P = 0.03), pepsinogen A/C ratio (1.8 +/- 0.3 vs. 4.1 +/- 0.6, P = 0.005) and mucosal somatostatin concentrations (2.75 +/- 0.60 vs. 4.48 +/- 1.08 mg/g protein, P = 0.038). Two patients in the hypergastrinaemia group had signs of delayed gastric emptying, but none in the normogastrinaemia group did (P = N.S.). In addition, both groups had a normal meal-stimulated gastrin response. CONCLUSION: Severe hypergastrinaemia during omeprazole maintenance therapy for GERD is associated with the duration of therapy and H. pylori infection, but not with abnormalities of gastric emptying or vagal nerve integrity.

Atrophic gastritis during long-term omeprazole therapy affects serum vitamin B12 levels.

BACKGROUND: Omeprazole maintenance therapy for gastro-oesophageal reflux disease (GERD) has been associated with an increased incidence of atrophic gastritis in H. pylori-infected patients and with a decreased absorption of protein-bound, but not of unbound cobalamin. AIM: : To test the hypothesis that the combination of decreased cobalamin absorption and atrophic gastritis decreases serum cobalamin levels during omeprazole therapy. METHODS: Forty-nine H. pylori-positive GERD patients were treated with omeprazole for a mean (+/- s.d.) period of 61 (25) months. At the start of omeprazole treatment (T0) and at the latest follow-up visit (T1), serum was obtained for measurement of cobalamin. Corpus biopsy specimens were obtained at entry and follow-up for histopathological scoring according to the updated Sydney classification. RESULTS: At inclusion, none of the 49 patients had signs of atrophic gastritis. During follow-up, 15 patients (33%) developed atrophic gastritis, nine of whom had moderate to severe atrophy. These 15 patients did not differ from the other 34 patients with respect to age, serum cobalamin at T0 or the duration of follow-up. During follow-up, no change was observed in the median serum cobalamin level in the 34 patients without atrophy; (T0) 312 (136-716) vs. (T1) 341 (136-839) pmol/L (P=0.1). In the 15 patients who developed atrophy, a decrease in cobalamin was seen from 340 (171 to 787) at baseline to 285 (156-716) at latest follow-up (P < 0.01). CONCLUSIONS: The development of atrophic gastritis during omeprazole treatment in H. pylori-positive GERD patients is associated with a decrease of serum vitamin B12 levels.

Parietal cell protrusions and fundic gland cysts during omeprazole maintenance treatment.

Parietal cell protrusion (PCP), swelling and bulging of parietal cells, has been observed in the oxyntic mucosa of patients receiving omeprazole. The frequency of this event and the underlying mechanisms remain to be clarified. As such, it is unknown whether there is a relation with either serum gastrin or Helicobacter pylori infection, and whether PCP predisposes to the development of fundic gland cysts (FGC). We therefore investigated the development of PCP and FGC in gastroesophageal reflux disease (GERD) patients treated with omeprazole and correlated findings to duration of therapy, gastrin, and H pylori infection. In a randomized, double-blinded study, GERD patients were evaluated by endoscopy with biopsy sampling for histology and culture at baseline, and after 3 and 12 months' therapy with omeprazole 40 mg daily. H pylori-positive patients were randomized to additional eradication therapy or placebo antibiotics at baseline. All histological slides were scored blinded for time and outcome of culture for the presence of PCP and FGC. Fasting serum samples from all visits were used for gastrin measurements. The prevalence of PCP increased during omeprazole therapy from 18% at baseline to 79% and 86% at 3 and 12 months (P < .001, baseline v both 3 and 12 months). The prevalence of FGC increased from 8% to 17% and 35% (P < .05, baseline v 12 months). The prevalence of PCP and FGC did not differ among the H pylori-positive and H pylori-negative patients at baseline (PCP 16% v 20% and FGC 7% v 8%, respectively). Whereas H pylori eradication did not significantly affect development of PCP (P = .7), FGC developed significantly more often in the H pylori-eradicated patients when compared with persistent H pylori-positive patients (P < .05). PCP development was related to serum gastrin rise during therapy. In conclusion, PCP occurs in most patients within the first months of omeprazole treatment and is related to increased gastrin levels. FGC develops more gradually and is enhanced by H pylori eradication.

Molecular alterations in early gastric carcinomas. No apparent correlation with Helicobacter pylori status.

Data on the differences in molecular profile between H pylori-positive and H pylori-negative early gastric carcinomas, if any, are almost nonexistent. We therefore investigated whether molecular differences can be observed between H pylori-positive and H pylori-negative early gastric carcinomas. Forty-five early gastric carcinomas were analyzed for alterations in certain oncogenes (ras, MDM2, c-erbB-2, cyclin D1), the p53 tumor suppressor gene, and the e-cadherin gene. Of these 28 carcinomas were H pylori-positive, and 17 were H pylori-negative. No significant differences were found in the groups irrespective of Lauren type; ras (0% vs 0%), MDM2 (0% vs 0%), c-erbB-2 (0% vs 0%), cyclin D1 (18% vs 29%), p53 (68% vs 47%), and e-cadherin (46% vs 41%). Helicobacter pylori-positive and H pylori-negative early gastric carcinomas do not differ in molecular profile. Although they may prove different when tested for other abnormalities, our findings suggest that the acquisition of molecular alterations occurs via an H pylori independent pathway.

Gastric mucosal morphological consequences of acid suppression: a balanced view.

In the chapter, an analysis of the literature on the relationship between Helicobacter pylori, the use of proton pump inhibitors and the development of atrophic gastritis is presented, and the difficulties of classifying gastritis and the new possibilities of quantifying chronic inflammation by morphometric analysis are discussed. The issue surrounding the necessity of eradicating H. pylori in H. pylori-positive patients has still not been solved. Most studies have now accepted that proton pump inhibitors indeed accelerate the onset of atrophic gastritis in H. pylori-positive patients, but evidence against such an association was published in one recent (Scandinavian) study; conclusions from this study have, however, been challenged by several groups. Some data are available on the efficacy of H. pylori eradication with regard to the prevention of atrophy. The limited significance of the development of parietal cell protrusions and fundic gland cysts is better understood, but much less is known of the development and long-term consequence of H. pylori-induced autoimmune gastritis. Finally, recent studies in H. pylori-positive patients indicate that treatment with proton pump inhibitors may promote bacterial N-nitrosation formation. These data taken together suggest that the eradication of H. pylori may be based not only on morphological arguments, but also on bacterial alterations in the gastric milieu.