OLGA staging for gastritis: a tutorial

Atrophic gastritis (resulting mainly from long-standing Helicobacter pylori infection) is a major risk factor for (intestinal-type) gastric cancer development and the extent/topography of the atrophic changes significantly correlates with the degree of cancer risk. The current format for histology reporting in cases of gastritis fails to establish an immediate link between gastritis phenotype and risk of malignancy. The histology report consequently does not give clinical practitioners and gastroenterologists an explicit message of use in orienting an individual patient's clinical management. Building on current knowledge of the biology of gastritis and incorporating experience gained worldwide by applying the Sydney System for more than 15 years, an international group of pathologists (Operative Link for Gastritis Assessment) has proposed a system for reporting gastritis in terms of stage (the OLGA staging system). Gastritis staging arranges the histological phenotypes of gastritis along a scale of progressively increasing gastric cancer risk, from the lowest (stage 0) to the highest (stage IV). This tutorial aims to provide unequivocal information on how to consistently apply the OLGA staging system in routine diagnostic histology practice.

Beneficial effect of resin salve in treatment of severe pressure ulcers: a prospective, randomized and controlled multicentre trial

BACKGROUND

Resin salve of the Norway spruce (Picea abies) has been used in folk medicine to heal wounds and infections.

OBJECTIVES

To study its clinical effectiveness in the treatment of pressure ulcers of the skin.

METHODS

A prospective, randomized, controlled multicentre trial involving 37 patients with grade II-IV pressure ulcers in 11 primary care hospitals was carried out between 2005 and 2007. The ulcers were randomly allocated to receive either resin salve or sodium carboxymethylcellulose hydrocolloid polymer treatment. The inclusion criterion was grade II-IV pressure ulcer. Exclusion criteria were a life expectancy of less than 6 months or a malignant disease. The primary outcome measure was complete healing of the ulcer within 6 months. Secondary outcome measures were partial healing of the ulcer, and successful eradication of bacterial strains cultured from the ulcers at study entry.

RESULTS

Thirteen patients of the resin group and nine patients of the control group completed the 6-month trial. All ulcers healed in 12 of the 13 patients (92%) in the resin group and in four of the nine patients (44%) in the control group (P=0.003; power 73%). Complete healing of the ulcers over time was significantly more common in the resin group than in the control group (P=0.013). Bacterial cultures from the ulcer area more often became negative within 1 month in the resin group.

CONCLUSIONS

Traditional resin salve is significantly more effective in the treatment of infected and noninfected severe pressure ulcers than cellulose polymer gauzes.

Antibacterial effects of home-made resin salve from Norway spruce (Picea abies)

Resin salve made from Norway spruce (Picea abies) is traditionally used in folk medicine to heal skin ulcers and infected wounds. Its antimicrobial properties were studied against certain human bacteria important in infected skin wounds. The sensitivity of the resin against Gram-positive and Gram-negative bacteria was studied in vitro by methods that are routinely used in microbiology laboratories. The resin salve exhibited a bacteriostatic effect against all tested Gram-positive bacteria but only against Proteus vulgaris of the Gram-negative bacteria. Interestingly, the resin inhibited the growth of bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE), both on agar plates and in culture media. The study demonstrated antimicrobial activity of the resin salve and provided objective evidence of its antimicrobial properties. It gives some explanations why the traditional use of home-made resin salve from Norway spruce is experienced as being effective in the treatment of infected skin ulcers.

Probiotic intervention decreases serum gastrin-17 in Helicobacter pylori infection

BACKGROUND

Previously we showed that a probiotic combination with L. rhamnosus GG was beneficial as an adjuvant therapy during H. pylori eradication.

AIM

To evaluate whether probiotic combination with LGG adheres to the upper gastrointestinal mucosa and modifies H. pylori colonisation and H. pylori induced inflammation.

METHODS

Thirteen patients referred for gastroduodenoscopy received a drink consisting of equal doses (2.5x10(9)CFU) of LGG, L. rhamnosus LC705, Propionibacterium freudenreichii JS and Bifidobacterium lactis Bb12 daily. Recovery of probiotics in biopsies (antrum, corpus, duodenum) and faecal samples was evaluated by strain-specific quantitative polymerase chain reaction. H. pylori colonization and gastric inflammation was investigated by urease activity ((13)C-urea breath test), histology and serum pepsinogen I, II and gastrin-17 measurements.

RESULTS

Twelve patients were fully investigated; of these three of the patients had LGG adhering to the biopsies at end of the intervention. Other probiotic strains were not detected, even though the recovery of all individual probiotic strains from the faeces was significantly increased (p<0.01). After the treatment, the level of (13)C-urea breath test (p=0.063) and gastrin-17 (p=0.046) decreased.

CONCLUSIONS

The decreases in (13)C-urea breath test and gastrin-17 indicate that the probiotic combination exerts a beneficial effect on gastric mucosa in H. pylori infected patients. LGG showed marginal ability to adhere to the upper gastrointestinal tract mucosa.

A biopsy-based quick test in the diagnosis of duodenal hypolactasia in upper gastrointestinal endoscopy

BACKGROUND AND STUDY AIMS

The usefulness of a new quick test for endoscopic diagnosis of adult-type hypolactasia was tested in duodenal biopsies. In this test, an endoscopic biopsy from the postbulbar duodenum is incubated with lactose on a test plate, and a color reaction develops within 20 min as a result of hydrolyzed lactose (a positive result) in patients with normolactasia, whereas no reaction (a negative result) develops in patients with severe hypolactasia.

PATIENTS AND METHODS

Two postbulbar duodenal biopsies were taken from 80 prospectively enrolled adult outpatients with dyspepsia. The biopsies were used for the Quick Lactase Test (Biohit PLC, Helsinki, Finland) and in biochemical disaccharidase (lactase, sucrase, and maltase) assays. In addition, the C/T (-13,910) genotype was determined from DNA extracted from gastric antral biopsies using polymerase chain reaction sequencing in genomic analysis of adult-type hypolactasia.

RESULTS

Twenty-one of 22 patients (95 %; 95 % CI, 87 - 100 %) with biochemical lactase activity < 10 U/g protein, but none of the 58 patients with lactase activity of 10 U/g protein or more had a negative result in the Quick Lactase Test. Seven of the 80 patients (9 %; 95 % CI, 3 - 15 %) had a Quick Lactase Test result that indicated mild hypolactasia (a mild color reaction). All patients with celiac disease (n = 6) had a negative Quick Lactase Test result. Nine of 74 patients (six patients with celiac disease were excluded) had a CC (-13,910) genotype in genomic testing, indicating adult-type hypolactasia. All of them had negative test results with the Quick Lactase Test. Twenty-six patients had a TT genotype, indicating normolactasia, and none of these patients had a negative test result in the Quick Lactase Test. Six of 39 patients (15 %; 95 % CI, 4 - 27 %) with a CT genotype had a negative result in the Quick Lactase Test.

CONCLUSIONS

The Quick Lactase Test effectively identifies patients with severe duodenal hypolactasia. In comparison with CC (adult-type hypolactasia) and TT individuals (normolactasia), the sensitivity and specificity of the Quick Lactase Test result was 100 %. In comparison with biochemical lactase assays, the sensitivity and specificity of a negative Quick Lactase Test for indicating hypolactasia (lactase activity < 10 U/g protein) were 95 % (95 % CI, 87 - 100 %) and 100 %, respectively.

Correlation between the allelic distribution of STRs in a Finnish population and phenotypically different gastrointestinal tumours: a study using four X-chromosomal markers (DXS7423, DXS8377, ARA, DXS101)

Microsatellite instability in tumours has been suggested as a model to study the process of short tandem repeat (STR) mutations. In the present study we have determined the allelic variation of four X-STRs (DXS7423, DXS8377, DXS101 and ARA) in a Finnish population of 103 individuals, and assessed whether a comparable allelic distribution could be found in a series of gastrointestinal cancers differing by the level of microsatellite instability. Fifty-seven gastric and colorectal cancers were stratified by autosomal STRs, and the mononucleotide marker BAT-26 into stable, low-level unstable and high-level unstable microsatellite (MSI-H) cancers, of which the last produced the majority of X-STR alleles. For the four markers analysed, a significant correlation of allele distribution between our Finnish population sample and MSI-H tumours was noted. Together, the eight MSI-H tumours found represented 80%, 66-80% and 100% of the DXS101 alleles in the Finnish, and in previously described Caucasian and Korean population samples, respectively. Of the ARA, DXS7423 and DXS8377 alleles in the Finnish population, 42%, 75% and 79% were found in the MSI-H cancers, respectively. The results suggest that analysis of STR variation in a relatively small number of MSI-H cancers may aid in pre-evaluation of their allelic distribution in a population.

Inflammation and cytokeratin 7/20 staining of cardiac mucosa in young patients with and without Helicobacter pylori infection

BACKGROUND

Both Helicobacter pylori and gastro-oesophageal reflux disease (GORD) may cause inflammation in cardiac mucosa. Intestinal metaplasia (IM) is found more often in GORD associated inflammation than in inflammation caused by H pylori, especially in young individuals.

AIM

To examine morphological differences in chronic inflammation in these two conditions by immunohistochemistry.

PATIENTS/METHODS

Tissue blocks from cardiac mucosa of patients <45 years were available as follows: 10 patients with chronic inflammation of cardiac mucosa (carditis) and H pylori gastritis (group 1); 10 patients with (possibly GORD related) carditis, but normal antrum and corpus (group 2); and 10 patients with non-inflamed cardiac mucosa and normal antrum and corpus (group 3). Haematoxylin and eosin staining and immunohistochemical staining for various inflammatory cells were performed for patients in groups 1 and 2 as follows: CD20 (B cells), CD3 (T cells), CD4 (T helper cells), CD8 (T suppressor cells), CD163 (macrophages), CD138 (plasma cells), and CD117 (mast cells). For all patients, cytokeratin 7/20 (CK7/20) staining was performed.

RESULTS

No clear differences were seen in the morphology of chronic inflammation between groups 1 and 2. In both, plasma cells were most abundant. CK7/20 staining showed no differences between these groups.

CONCLUSION

Helicobacter pylori negative (possibly GORD associated) and H pylori related carditis cannot be distinguished on a morphological basis. The stronger tendency towards IM in the first entity cannot be explained by differences in the type of inflammation. Barrett-type CK7/20 staining seems typical for cardiac mucosa, irrespective of the type of inflammation or presence of IM.

Does the 'test-and-treat' strategy work in primary health care for management of uninvestigated dyspepsia? A prospective two-year follow-up study of 1552 patients

BACKGROUND

Although the 'test-and-treat' strategy is suggested as first-line therapy for uninvestigated dyspepsia, no large-scale studies in a real-life setting are available.

METHODS

1552 dyspeptic patients aged between 25 and 60 with no alarm symptoms were recruited to the study. After screening with a 13C-urea breath test, they were randomized into three treatment arms: Helicobacter pylori-positive either to eradication therapy with OAM (omeprazole, amoxycillin and metronidazole) (Hp+/erad) or omeprazole 20 mg daily (Hp+/ome) for 10 days, whereas H. pylori-negative patients (Hp-/ome) were treated with 20 mg omeprazole for 10 days. Gastrointestinal symptoms were registered at baseline at 1 and 2 years on the Gastrointestinal Symptom Rating Scale (GSRS) and quality of life with the Psychological General Well-Being index (PGWB). Additional visits, referrals for and number of endoscopies and their findings were registered during the 2 years' follow-up.

RESULTS

Of the 1552 patients, 583 were H. pylori-positive (37.6%), and 288 of these were randomized for omeprazole and 295 to OAM. The Hp-/ome group had fewer general practitioner (GP) contacts (P<0.0001) than the H. pylori-positive groups. Eradication therapy significantly improved general well-being and reduced upper gastrointestinal symptoms: abdominal pain (P=0.0001), heartburn (P=0.0061), acid regurgitation (P=0.003), hunger pain (P=0.009), especially in Hp+/erad. Peptic ulcer was found in 6.2%, 1.0%, 0.2% in Hp+/ome, Hp-+/erad and Hp-/ome, respectively (P=0.0007). Only 3 patients (1.0%) developed peptic ulcers in Hp-+/erad, all eradication failures.

CONCLUSIONS

In uninvestigated dyspepsia, a negative test result for H. pylori reduces the number of GP contacts and endoscopy referrals compared to H. pylori-positive regardless of eradication therapy. Applied in real life, the test-and-treat strategy failed to reduce the number of endoscopies, but significantly reduced peptic ulcer disease and improved dyspeptic symptoms and quality of life.

Evaluation of gastrointestinal cancer tissues as a source of genetic information for forensic investigations by using STRs

Malignant tissue samples may sometimes be the only source of biological material for forensic investigations, including identification of individuals or paternity testing. However, in use of such samples, uncertainties due to microsatellite instability (MSI) and loss of heterozygosity (LOH) often associated with neoplasias may be encountered. In this study, we have analysed the applicability of autosomal tetranucleotide short tandem repeat (STR) markers, which are routinely used in forensic analysis, to gain genetic information. MSI and LOH were analysed in 41 surgically removed gastrointestinal cancer specimens and the adjascent non-cancerous tissue marginals. The cancer specimens showed great variability in their genetic phenotypes due to MSI or LOH, with only 32% being microsatellite-stable. Of the 15 autosomal STR loci analysed, only TH01 had no MSI-type alteration in these samples. The loci most frequently affected by MSI were D8S1179, D21S11, D18S51 and D19S433 (MSI in 15-17% of cases). LOH-type alterations were observed at all of the loci, including the amelogenin locus used for sex determination. The highest LOH frequency was found at locus D18S51 (27%). The genetic alterations at the marker loci may indicate false homozygosity or heterozygosity, and false gender may result from erroneous deduction of DNA profiles. Therefore, typing of autosomal STRs from malignant tissues in forensic settings warrants careful interpretation of MSI and LOH results together with microscopic analysis of a tissue specimen. Results by two commercially available and widely used forensic DNA profiling kits used here were comparable.

Prevalence of low vitamin B12 and high homocysteine in serum in an elderly male population: association with atrophic gastritis and Helicobacter pylori infection

BACKGROUND

Deficiency of vitamin B12 raises the serum and tissue levels of homocysteine. Atrophic corpus gastritis results in impaired secretion of intrinsic factor and may lead to malabsorption of vitamin B12 in the intestine. We examined how common an undiagnosed vitamin B12 deficiency is among elderly men in the general population and, in particular, how often this deficiency is related to atrophic corpus gastritis.

METHODS

The serum level of pepsinogen I (S-PGI) was assayed in a population-based sample of 12,252 men (age 51-65 years) from two cities in Finland. In this sample, all 635 men with S-PGI < 25 microg/l formed Series A ('males with atrophic corpus gastritis'). Series C (controls--'males without atrophic corpus gastritis)' with a non-atrophic gastric corpus was formed as a random sample of men (n = 402) with S-PGI > or = 50 microg/l. Serum levels of vitamin B12 (S-B12), folate (S-Fol), total homocysteine (S-Hcy) and Helicobacter pylori antibodies (S-HpAb) were assayed in all, or in large subsamples, of the men in Series A and C. RESULTS The men in Series A had significantly lower S-B12 and S-Fol levels than those in Series C. In Series A, 172 of 613 men tested (28%) had S-B 12 < 170 pmol/ 1, and 133 men (22%) had S-B 12 in the range 170-219 pmol/l. The corresponding prevalences were 7% (P < 0.001) and 17% (P < 0.001) in Series C, respectively. The mean S-Hcy was significantly higher in Series A in men with low S-B12 than the mean S-Hcy in Series C in men with normal S-B12. The prevalence of S-Hcy > 15 ,micromol/l was 27% in Series A and 15% in Series C (P < 0.05; chi2 = 4.63). Among subjects with S-B 12 < 220 pmol/l, 46% (104 of 226 men tested) in Series A and 16% (16 of 99) in Series C had S-Hcy > or = 15 micromol/l (P < 0.001). The mean S-Hcy was significantly (P < 0.001) higher in men with S-B12 in the range 170-219 pmol/l in Series A (mean 14.6 +/- 5.0 micromol/l) than in Series C (11.3 +/- 3.0 micromol/l). It was extrapolated that 2.5% of men in the age group 51-65 years in the present study population had a low S-B12 (< 220 pmol/l) level that associated with atrophic corpus gastritis. Of these men, 72% (128 of 179 tested) had an elevated S-HpAb level.

CONCLUSIONS

Low S-B12 related to atrophic corpus gastritis is relatively common (prevalence 2.5%) among elderly males in the general population. An ongoing H. pylori infection occurs in three-fourths of these cases.

Inflammation in the cardia

The detection of chronic inflammation and intestinal metaplasia at the gastric side of a normal-appearing esophagogastric junction started active research on gastric cardia pathology. The main causes for this interest have been the increasing incidence of gastroesophageal reflux disease (GERD) and cardia adenocarcinoma. Many controversies still exist. It is even controversial whether noninflamed gastric cardia epithelium is a normal structure present at birth or an acquired lesion as a consequence of GERD. Similarly, the pathogenesis of chronic inflammation and intestinal metaplasia of gastric cardia are a matter of debate. Some researchers consider these lesions to be a consequence of Helicobacter pylori infection, whereas others think that chronic cardia inflammation and intestinal metaplasia are consequences of GERD. In this paper we review recent published studies in this field.

Non-endoscopic diagnosis of atrophic gastritis with a blood test. Correlation between gastric histology and serum levels of gastrin-17 and pepsinogen I: a multicentre study

BACKGROUND AND AIMS

Serum levels of gastrin-17 (S-G-17) and pepsinogen I (S-PGI) are biomarkers of gastric antral and corpus mucosa, respectively. In a prospective multicentre investigation, we determined whether these tests, together with the assay of Helicobacter pylori antibodies, are a non-endoscopic tool for the diagnosis of atrophic gastritis.

MATERIALS AND METHODS

The series comprised 404 consecutive adult outpatients undergoing diagnostic upper-gastrointestinal endoscopy for various dyspeptic symptoms in five outpatient clinics. Gastric biopsies from the antrum and corpus (at least two biopsies from both sites) were available from all patients, and they were evaluated according to the guidelines of the updated Sydney system. S-PGI and S-G-17 were assayed with ELISA methods using monoclonal antibodies to pepsinogen I and amidated gastrin-17. In addition to the fasting level (S-G-17(fast)), a postprandial S-G-17 (S-G-17(prand)) level was measured 20 min after ingestion of a protein-rich drink. H. pylori antibodies were determined using a polyclonal EIA method.

RESULTS

S-G-17(prand) (and S-G-17(fast)) and S-PGI levels decreased with increasing grade of atrophy of the antrum or corpus, respectively. S-G-17(prand) levels were significantly lower in patients with advanced (moderate or severe) atrophic antral H. pylori gastritis than in those with non-atrophic H. pylori gastritis. All patients with a resected antrum demonstrated S-G-17(prand) levels that were almost undetectable. Of the nine patients with an H. pylori-positive moderate or severe atrophic antral gastritis, six had S-G-17(prand) levels below 5 pmol/l. Similarly, S-PGI levels were significantly lower in patients with advanced corpus atrophy than in those without. Of the 45 patients with moderate or severe corpus atrophy in endoscopic biopsies, 35 patients had S-PGI levels < 25 microg/l. By using the cut-off levels for S-G-17(prand) and S-PGI with the best discrimination, the sensitivity and specificity of the blood test panel in delineation of patients with advanced atrophic gastritis (either in the antrum or the corpus, or both) were 83% and 95%, respectively. The predictive values of the positive and negative test results were 75% and 97%, respectively. In the diagnosis of atrophic gastritis, the application of S-G-17(fast) showed a slightly lower sensitivity and specificity than the application of S-G-17(prand) as a biomarker for antral atrophy.

CONCLUSIONS

The diagnosis of atrophic gastritis obtained with the blood test panel of S-G-17, S-PGI and H. pylori antibodies is in good agreement with the endoscopic and biopsy findings. The panel is a tool for non-endoscopic diagnosis and screening of atrophic gastritis.

Do Japanese and Swedish peptic ulcer patients respond differently to Helicobacter pylori eradication therapies and what are their histological features?

BACKGROUND

As a consequence of gastric histological differences, Japanese and Swedish peptic ulcer (PU) patients may respond differently to Helicobacter pylori eradication therapies.

METHODS

The study was single-blind and compared four eradication therapies in Japanese and Swedish patients with healed gastric (GU) or duodenal (DU) ulcer. Swedish patients received either (a) omeprazole+clarithromycin (OC, where O = 20 mg, C = 500 mg) for 2 weeks, or triple therapy with (b) omeprazole + amoxicillin + clarithromycin (OAC-L where O = 20mg, A = 1 g, C = 250 mg); (c) OAC-H (where O = 20 mg, A-1 g, C-500 mg); or (d) omeprazole + metronidazole + clarithromycin (OMC, where O = 20 mg, M = 400 mg, C = 250 mg) for 1 week. Antibiotic doses were weight-adjusted downwards in Japanese patients. H. pylori was assessed using the urea breath test (UBT), histology and culture pre-entry, with UBT being repeated 4 and 8 weeks after stopping treatment. Histology and culture were repeated if the UBT was positive post-therapy.

RESULTS

Recruitment included 120 patients from Japan (43 GU, 61 DU, 16 GU+DU) and 120 from Sweden (119 DU, 1 GU+DU). There were 26 exclusions from a FAS analysis due to H. pylori negativity (14), no drug administration (7) or no data after visit 1 (5). Eradication rates (FAS) from Japan were (a) 63%, (b) 93%, (c) 96% or (d) 96%, and for Sweden (a) 92%, (b) 86%, (c) 93% or (d) 96%. Dual therapy was less effective in patients with gastric atrophy associated with GU disease. Tolerability was good in all treatment groups, with no serious adverse events.

CONCLUSION

Triple therapies were safe and effective for H. pylori eradication in Japanese and Swedish peptic ulcer patients. Dual therapy was significantly less effective in the Japanese patients, half of whom had a history of GU and more abnormal histology than in the Swedish patients, all of whom had DU.

Comparison of gastric histology among Swedish and Japanese patients with peptic ulcer and Helicobacter pylori infection

BACKGROUND

The natural course of Helicobacter pylori gastritis may vary between different ethnic groups. Gastric histopathology and the occurrence of H. pylori organisms in the stomach were investigated in healed duodenal (DU) and gastric (GU) ulcer patients recruited in Sweden (S) and Japan (J) in an identical trial.

METHODS

In 203 patients (JGU = 39, JDU = 55, SDU = 109), various morphological gastritis variables and H. pylori were assessed from biopsy specimens obtained using a specific sampling protocol and interpreted according to guidelines of the updated Sydney grading system.

RESULTS

The ratio of GU:DU was observed to be very different between the recruited Japanese (39:55) and Swedish (0:109) patients. A comparison of data from SDU and JDU showed that the prevalence of H. pylori infection and the antral predominant gastritis demonstrated by both SDU and JDU were essentially identical. A comparison of data from JDU and JGU demonstrated a greater prevalence of H. pylori infection in the antrum, but not corpus, of JDU compared to JGU patients. The prevalence of atrophy and intestinal metaplasia was higher in both the antrum and corpus of JGU compared to JDU in all patients.

CONCLUSIONS

The site specified biopsy methodology and standardized interpretation criteria utilized in this study clearly show that the histotopographic profile of Swedish and Japanese DU patients is essentially the same.

Pepsinogen A, pepsinogen C, and gastrin as markers of atrophic chronic gastritis in European dyspeptics

Serum levels of pepsinogen and gastrin are parameters that can be used as biomarkers for gastric mucosa. The aim of this study was to validate these serum biomarkers, that is pepsinogen A (PGA), pepsinogen C (PGC), PGA/PGC ratio, and gastrin, as screening tests for precancerous lesions: atrophic chronic gastritis (ACG) or Helicobacter pylori-related corpus-predominant or multifocal atrophy. The study population was comprised of a subsample of 284 patients from the 451 included in the Eurohepygast cohort, between 1995 and 1997. The concentrations of PGA, PGC, and gastrin were measured by radioimmunoassays. Histological diagnosis was the gold standard. Cut-off points were calculated using receiving operator characteristics (ROC) curves. Factors linked to variation of biomarkers were identified using multivariate linear regression. The mean of each biomarker in the sample was: PGA, 77.4 microg x l(-1); PGC, 13.2 microg x l(-1); PGA/PGC, 6.7; and gastrin, 62.4 ng x l(-1). For ACG patients, the areas under the PGA, PGC, PGA/PGC, and gastrin ROC curves were 0.55, 0.62, 0.73, and 0.58, respectively. The best cut-off point for PGA/PGC was 5.6, with sensitivity 65% and specificity 77.9%. For H. pylori-related corpus-predominant or multifocal atrophy, the areas under the respective ROC curves were 0.57, 0.67, 0.84, and 0.69. The best cut-off point for PGA/PGC was 4.7, with sensitivity 77.1% and specificity 87.4%. The results suggested that only the PGA/PGC ratio can be considered as a biomarker for precancerous lesions of the stomach, and may be useful as a screening test.

Diagnosis of atrophic gastritis from a serum sample

On the basis of the levels of serum pepsinogen I (S-PGI) and gastrin-17 (S-G-17) as well as Helicobacter pylori antibodies it is possible to establish with high sensitivity and specificity whether the patient has gastritis, whether the gastritis is atrophic or not and in which part of the stomach the atrophic changes are located. The tests enable the identification of patients whose risk of gastric cancer, consequences of vitamin B12 deficiency or peptic ulcer is increased considerably and who should therefore undergo gastroscopy. They also facilitate diagnosis of non-atrophic Helicobacter gastritis enabling treatment before endoscopy.

Inflammation and intestinal metaplasia at the squamocolumnar junction in young patients with or without Helicobacter pylori infection

BACKGROUND

Intestinal metaplasia (IM) in the oesophagus is a known risk factor for adenocarcinoma of the oesophagus. The incidence of adenocarcinoma of the cardia and oesophagus has increased in Western countries simultaneously with a decrease in Helicobacter pylori prevalence.

AIMS

To determine the association of H pylori infection with inflammation and IM at the squamocolumnar junction (SCJ) in young individuals.

PATIENTS

A total of 168 (121 women; 72%) consecutive outpatients, </=45 years, undergoing gastroscopy, and with no prior H pylori eradication treatment.

METHODS

Biopsy specimens taken from the antrum, corpus, SCJ, and oesophagus were assessed according to the updated Sydney system, and type of IM (complete or incomplete) was determined. Serum samples from H pylori positive patients were studied for CagA antibodies.

RESULTS

In 86% of 37 patients with gastritis in the antrum and/or corpus (24 histologically H pylori positive) and in 23% of 125 patients with a healthy stomach, inflammation was present in the glandular mucosa at the SCJ. In the latter, cardiac mucosa more often than fundic mucosa at the SCJ was inflamed (p<0.001), the inflammation was usually milder in nature, and was associated with signs of reflux disease. IM (incomplete or complete) at the SCJ was evident in nine of those 24 with a healthy stomach and inflamed cardiac mucosa at the SCJ but in none of those with H pylori gastritis.

CONCLUSIONS

IM at the SCJ can also appear in young individuals in whom it seems to be associated with reflux related isolated inflammation in cardiac mucosa at the SCJ but not with H pylori gastritis.

Gastric metaplasia and chronic inflammation at the duodenal bulb mucosa

BACKGROUND

Chronic inflammation and gastric metaplasia are often observed in biopsy specimens from the duodenal bulb of Heliobacter pylori positive patients with duodenal ulcer disease (DU).

AIMS

We set out to investigate the prevalence of these lesions and their associations with other gastric and duodenal histopathological lesions.

PATIENTS

A total of 1255 consecutive patients who underwent upper gastrointestinal endoscopy were recruited into the present study.

METHODS

Two biopsy specimens were obtained from each of the following sites: duodenal bulb, gastric antrum, gastric body, and distal to the superior duodenal angle. These specimens were stained with hematoxylin-eosin, alcian blue periodic acid Schiff (pH 2.5) and modified Giemsa (Heliobacter pylori infection was determined only by histology).

RESULTS

The mean age of the study population was 57 years, and male:female ratio 1:1.6. Overall, 235 (19%) had gastric metaplasia and/or chronic inflammation in the duodenal bulb mucosa, and H. pylori organisms could be found in 17 (1%). In univariate analyses, gastric metaplasia and/or chronic duodenal bulb inflammation positively associated with male sex (p = 0.046), Heliobacter pylori-positive chronic gastritis (p = 0.033), villous atrophy of distal duodenal mucosa, i.e., coeliac disease (p < 0.001), duodenal ulcer (p < 0.001), and duodenal bulb deformity and scarring in endoscopy (p < 0.001), but not with age (p = 0.7) nor use of nonsteroidal anti-inflammatory drugs (p = 0.055). Multivariate analysis revealed that independent risk factors for gastric metaplasia and chronic inflammation in duodenal bulb were duodenal Heliobacter pylori infection (odds ratio 1.6, 95% confidence interval CI 1.1-2.1), and villous atrophy of the distal duodenal mucosa (odds ratio 12.7, 95% CI 4.4-36.5), while chronic atrophic gastritis was protective against them (odds ratio 0.5, 95% CI 0.3-0.8).

CONCLUSIONS

In addition to Heliobacter pylori infection, duodenal bulb gastric metaplasia and chronic inflammation may result from predisposition to toxic dietary components in gluten-sensitive subjects.

Comparison of Gastric Histology Among Swedish and Japanese Patients with Peptic Ulcer and &lt;emph type="2"&gt;Helicobacter pylori&lt;/emph&gt; Infection

BACKGROUND

The natural course of Helicobacter pylori gastritis may vary between different ethnic groups. Gastric histopathology and the occurrence of H. pylori organisms in the stomach were investigated in healed duodenal (DU) and gastric (GU) ulcer patients recruited in Sweden (S) and Japan (J) in an identical trial.

METHODS

In 203 patients (JGU = 39, JDU = 55, SDU = 109), various morphological gastritis variables and H. pylori were assessed from biopsy specimens obtained using a specific sampling protocol and interpreted according to guidelines of the updated Sydney grading system.

RESULTS

The ratio of GU:DU was observed to be very different between the recruited Japanese (39:55) and Swedish (0:109) patients. A comparison of data from SDU and JDU showed that the prevalence of H. pylori infection and the antral predominant gastritis demonstrated by both SDU and JDU were essentially identical. A comparison of data from JDU and JGU demonstrated a greater prevalence of H. pylori infection in the antrum, but not corpus, of JDU compared to JGU patients. The prevalence of atrophy and intestinal metaplasia was higher in both the antrum and corpus of JGU compared to JDU in all patients.

CONCLUSIONS

The site specified biopsy methodology and standardized interpretation criteria utilized in this study clearly show that the histotopographic profile of Swedish and Japanese DU patients is essentially the same.

Immunohistochemical study of neuroendocrine cells at the gastric cardia mucosa

BACKGROUND/AIMS

The gastric cardia mucosa is a narrow band of tissue between the oesophagus and the stomach. The physiological role of this tissue is unknown. This study examined the presence and characteristics of neuroendocrine cells at this site.

METHODS

Biopsy samples were obtained from across normal appearing squamocolumnar junctions. The cardiac mucosa was defined as the presence of special type mucosa composed of mucous secreting glands in the immediate vicinity of oesophageal squamous epithelium. Biopsy specimens were stained with haematoxylin and eosin, alcian blue (pH 2.5) periodic acid Schiff, and modified Giemsa. The chromogranin A and Fontana-Masson stains were used to identify neuroendocrine cells, which were also stained immunohistochemically for gastrin, serotonin, glucagon, pancreatic polypeptide, somatostatin, and vasoactive intestinal peptide.

RESULTS

Chromogranin positive cells were seen in 18 cases with adequate biopsy specimens from the gastric cardia mucosa. These cells were all serotonin positive, but stains for other peptide hormones remained negative. Serotonin positive cells were detected only at the base of foveolae at the periphery of mucous secreting cardiac glands, giving a microscopic appearance resembling that of endocrine cells at the gastric antrum. The presence and numbers of serotonin positive cells did not correlate with chronic inflammation or intestinal metaplasia of the cardiac mucosa. These cells were seen both in Helicobacter pylori positive and negative patients.

CONCLUSIONS

Serotonin positive cells appear to be the sole neuroendocrine cell type at the gastric cardia mucosa. These cells may have a role in regulating the physiology of the gastric cardia mucosa and the lower oesophageal sphincter.

Impact of Helicobacter pylori eradication on heartburn in patients with gastric or duodenal ulcer disease -- results from a randomized trial programme

BACKGROUND

Helicobacter pylori infection has been proposed as a protective factor against the development of gastro-oesophageal reflux disease.

AIM

To study heartburn and endoscopic findings before and after H. pylori eradication therapy in patients with peptic ulcer disease.

METHODS

In a multicentre trial programme, patients (n = 1497) were randomized to the omeprazole triple therapy group or to the control group, and were followed for 1-6 months after treatment. Patients in whom the infection was eradicated were compared with those in whom infection persisted. The severity of heartburn was measured at baseline and at each return visit. Endoscopy was performed 6 months after therapy in two of the five studies.

RESULTS

In patients with duodenal ulcer, there was a significantly lower prevalence of heartburn after successful eradication of H. pylori relative to that after failed eradication (estimated odds ratio, 0.48). The reduction in the prevalence of heartburn in patients with gastric ulcer was independent of the post-treatment H. pylori status. In studies in which ulcer relapse was included in the model, this factor emerged as a significant factor for heartburn. The observed incidence of oesophagitis at the last visit was not influenced by H. pylori status.

CONCLUSIONS

Eradication of H. pylori in patients with peptic ulcer disease was associated with a reduced prevalence of heartburn. Prevention of ulcer relapse could be the true cause of this reduction.

Impact of Helicobacter pylori eradication on heartburn in patients with gastric or duodenal ulcer disease -- results from a randomized trial programme

BACKGROUND

Helicobacter pylori infection has been proposed as a protective factor against the development of gastro-oesophageal reflux disease.

AIM

To study heartburn and endoscopic findings before and after H. pylori eradication therapy in patients with peptic ulcer disease.

METHODS

In a multicentre trial programme, patients (n = 1497) were randomized to the omeprazole triple therapy group or to the control group, and were followed for 1-6 months after treatment. Patients in whom the infection was eradicated were compared with those in whom infection persisted. The severity of heartburn was measured at baseline and at each return visit. Endoscopy was performed 6 months after therapy in two of the five studies.

RESULTS

In patients with duodenal ulcer, there was a significantly lower prevalence of heartburn after successful eradication of H. pylori relative to that after failed eradication (estimated odds ratio, 0.48). The reduction in the prevalence of heartburn in patients with gastric ulcer was independent of the post-treatment H. pylori status. In studies in which ulcer relapse was included in the model, this factor emerged as a significant factor for heartburn. The observed incidence of oesophagitis at the last visit was not influenced by H. pylori status.

CONCLUSIONS

Eradication of H. pylori in patients with peptic ulcer disease was associated with a reduced prevalence of heartburn. Prevention of ulcer relapse could be the true cause of this reduction.

Helicobacter pylori and different topographic types of gastritis: treatment response after successful eradication therapy in functional dyspepsia

BACKGROUND

Helicobacter pylori gastritis is usually a lifelong disease which can cause different topographical inflammatory reactions and induce divergent effects on acid secretion in humans. High acid output and antrum-predominant gastritis are associated with duodenal ulcer disease, whereas corpus-predominat gastritis has been associated with low acid output and risk of gastric carcinoma. The objective of this study was to evaluate the role of different gastritis subtypes in the long-term treatment response of H. pylori-positive functional dyspepsia.

METHODS

The gastric biopsies from 143 H. pylori-positive patients with functional dyspepsia were classified in accordance with the Sydney System as antrum-predominant gastritis, pangastritis or corpus-predominant gastritis. The patients were randomized to receive either eradication therapy or placebo antibiotics. Moreover, to standardize acid suppression every patient received omeprazole therapy for the first 3 months. Dyspeptic symptoms were evaluated from a questionnaire and the follow-up time was 12 months. In addition, delta-over-baseline (DOB) values of the 13C-urea breath test (UBT) were analysed from a subgroup of 36 patients to measure urease activity of the stomach.

RESULTS

After 1 year, the dyspepsia symptom score was 7.4 +/- 3.0 (95% CI 6.6-8.2) in successfully H. pylori-eradicated patients and 7.6 +/- 3.1 (95% CI 6.9-8.4) in controls (P = ns). Among patients with antrum-predominant gastritis, dyspepsia score was reduced more in subjects whose H. pylori was eradicated than in controls with ongoing infection (-3.6 +/- 2.9 versus -1.7 +/- 2.9; P = 0.05). High urease activity of the stomach was associated with severe or moderate chronic antrum-predominant gastritis.

CONCLUSIONS

Patients with antrum-predominant H. pylori-positive chronic gastritis and functional dyspepsia get symptom improvement after successful eradication therapy. A high DOB value of UBT is associated with these patients.

Gastric mucosal atrophy: interobserver consistency using new criteria for classification and grading

BACKGROUND AND AIMS

Considerable difficulties persist amongst pathologists in agreeing on the presence and severity of gastric atrophy. An international group of pathologists pursued the following aims: (i) to generate an acceptable definition and a simple reproducible classification of gastric atrophy; and (ii) to develop guidelines for the recognition of atrophy useful for increasing agreement among observers.

METHODS

After redefining atrophy as the 'loss of appropriate glands' and examining histological samples from different gastric compartments, three categories were identified: (i) negative; (ii) indefinite; (iii) atrophy, with and without intestinalization. Atrophy was graded on a three-level scale. Interobserver reproducibility of the classification was tested by kappa statistics (general and weighted) in a series of 48 cases.

RESULTS

The medians of the general agreement and weighted kappa values were 0.78 and 0.73, respectively. The weighted kappa coefficients, obtained by cross-tabulating the evaluation of each pathologist against all others, were, with only one exception, > 0.4 (moderate to excellent agreement).

CONCLUSIONS

By using the definition of atrophy as the loss of appropriate glands and distinguishing the two main morphological entities of metaplastic and non-metaplastic types, a high level of agreement was achieved by a group of gastrointestinal pathologists trained in different cultural contexts.

Serum levels of amidated gastrin-17 and pepsinogen I in atrophic gastritis: an observational case-control study

BACKGROUND

Helicobacter pylori infection is often diagnosed with non-endoscopic methods, such as serology or breath or antigen stool tests. These tests provide information on the presence or absence of the H. pylori gastritis only. We investigated whether atrophic gastritis can be diagnosed and typed non-endoscopically if the serum levels of pepsinogen I (S-PGI) and gastrin-17 (S-G-17) are assayed in connection with H. pylori testing.

METHODS

The present investigation is an observational case-control study comprising 100 selected dyspeptic outpatients with (cases) or without (controls) advanced (moderate or severe) atrophic gastritis. Before the blood tests, all patients underwent a diagnostic gastroscopy with multiple biopsies. The series of cases includes 56 patients. Eight had an advanced antrum limited atrophic gastritis, 13 had resected antrum (in two of whom the corpus mucosa in the stump was atrophic), and 30 had corpus-limited atrophic gastritis. Four patients had an advanced atrophic gastritis in both the antrum and corpus (multifocal atrophic gastritis), and the whole stomach was removed in one patient. Twenty of the 44 controls had a non-atrophic H. pylori gastritis. Both the antrum and corpus were normal and healthy in 24 patients. The S-PGI and S-G-17 were determined with EIA methods using monoclonal antibodies to PGI and amidated G-17. Postprandial S-G-17 (S-G-17prand) was measured 20 min after a protein-rich drink. The H. pylori antibodies were assayed with a polyclonal EIA method.

RESULTS

A low S-PGI (<25 microg/l; an empirical cut-off with best discrimination) was found in 31 of 37 patients (84%) with and in 3 of 63 patients (5%) without corpus atrophy in the biopsy specimens. A low S-G-17prand (<5 pmol/l) was found in all 8 patients with H. pylori-associated antral atrophy and in 11 of 14 patients (79%) with resected antrum but in 3 of 20 control patients (15%) with H. pylori-related non-atrophic gastritis. Median and mean values of both S-G-17prand and S-PGI decreased with increasing grade of antral and corpus atrophy, respectively. Among all patients with atrophic gastritis (multifocal atrophic gastritis, or atrophic gastritis limited to antrum or corpus) or resected stomach, 50 of 56 patients (89%; Cl 95%: 81%-97%) had a low S-PGI and/or a low S-G-17prand with positive H. pylori serology. Such low values werc found in 3 of the 44 control patients (7%; CI 95%: 0%-14%).

CONCLUSIONS

Low serum levels of G-17prand and PGI are conceivable biomarkers of atrophic antral and corpus gastritis, respectively. A low S-G-17prand is a sign of the multifocal or antrum-limited atrophic gastritis in patients infected with H. pylori.

Serum levels of amidated gastrin-17 and pepsinogen I in atrophic gastritis: an observational case-control study

BACKGROUND

Helicobacter pylori infection is often diagnosed with non-endoscopic methods, such as serology or breath or antigen stool tests. These tests provide information on the presence or absence of the H. pylori gastritis only. We investigated whether atrophic gastritis can be diagnosed and typed non-endoscopically if the serum levels of pepsinogen I (S-PGI) and gastrin-17 (S-G-17) are assayed in connection with H. pylori testing.

METHODS

The present investigation is an observational case-control study comprising 100 selected dyspeptic outpatients with (cases) or without (controls) advanced (moderate or severe) atrophic gastritis. Before the blood tests, all patients underwent a diagnostic gastroscopy with multiple biopsies. The series of cases includes 56 patients. Eight had an advanced antrum limited atrophic gastritis, 13 had resected antrum (in two of whom the corpus mucosa in the stump was atrophic), and 30 had corpus-limited atrophic gastritis. Four patients had an advanced atrophic gastritis in both the antrum and corpus (multifocal atrophic gastritis), and the whole stomach was removed in one patient. Twenty of the 44 controls had a non-atrophic H. pylori gastritis. Both the antrum and corpus were normal and healthy in 24 patients. The S-PGI and S-G-17 were determined with EIA methods using monoclonal antibodies to PGI and amidated G-17. Postprandial S-G-17 (S-G-17prand) was measured 20 min after a protein-rich drink. The H. pylori antibodies were assayed with a polyclonal EIA method.

RESULTS

A low S-PGI (<25 microg/l; an empirical cut-off with best discrimination) was found in 31 of 37 patients (84%) with and in 3 of 63 patients (5%) without corpus atrophy in the biopsy specimens. A low S-G-17prand (<5 pmol/l) was found in all 8 patients with H. pylori-associated antral atrophy and in 11 of 14 patients (79%) with resected antrum but in 3 of 20 control patients (15%) with H. pylori-related non-atrophic gastritis. Median and mean values of both S-G-17prand and S-PGI decreased with increasing grade of antral and corpus atrophy, respectively. Among all patients with atrophic gastritis (multifocal atrophic gastritis, or atrophic gastritis limited to antrum or corpus) or resected stomach, 50 of 56 patients (89%; Cl 95%: 81%-97%) had a low S-PGI and/or a low S-G-17prand with positive H. pylori serology. Such low values werc found in 3 of the 44 control patients (7%; CI 95%: 0%-14%).

CONCLUSIONS

Low serum levels of G-17prand and PGI are conceivable biomarkers of atrophic antral and corpus gastritis, respectively. A low S-G-17prand is a sign of the multifocal or antrum-limited atrophic gastritis in patients infected with H. pylori.

No support for endoscopic surveillance for gastric cancer in hereditary non-polyposis colorectal cancer

BACKGROUND

The DNA mismatch repair gene mutations underlying hereditary non-polyposis colorectal cancer syndrome (HNPCC) also predispose, besides colorectal and endometrial cancer, to gastric cancer. usually of the intestinal type. The carcinogenetic pathway behind the elevated gastric cancer risk is largely unknown.

METHODS

The aim of this study was to determine whether there are any premalignant lesions to search for in gastric surveillance in HNPCC by comparing gastric histopathology between mutation-positive and mutation-negative family members. We searched for differences in occurrence of Helicobacter pylori, inflammation, atrophy, intestinal metaplasia and dysplastic changes. Upper gastrointestinal endoscopy was performed for 73 mutation-positive and 32 mutation-negative family members.

RESULTS

One case of duodenal cancer was detected in the mutation-positive group, but no gastric neoplastic lesions were seen in either group. There were no differences in the occurrence of polyps, H. pylori, inflammation, activity, atrophy nor intestinal metaplasia tested with binaric, logistic, regression analysis.

CONCLUSIONS

We conclude that surveillance gastroscopy may not be beneficial in HNPCC, since neither cases of early cancer nor premalignant lesions could be detected in our series of 73 mutation-positive subjects.

Foveolar hyperplasia at the gastric cardia: prevalence and associations

AIMS

In the gastric antrum and body, foveolar hyperplasia is a feature of reactive gastritis resulting from--for example, duodenogastric bile reflux and the use of non-steroidal anti-inflammatory drugs (NSAIDs). The aim of this study was to examine the occurrence and clinical relevance of gastric cardiac foveolar hyperplasia.

METHODS

The study population was drawn from a consecutive series of 1698 patients sent for upper gastrointestinal endoscopy. Only cases without chronic gastritis or Barrett's oesophagus were included. The final study population consisted of 307 patients.

RESULTS

Foveolar hyperplasia was seen in the gastric cardiac mucosa in 31 (10%) patients with histologically normal stomach mucosa, but none had endoscopically noticeable hyperplastic polyps. Compared with patients without gastric cardiac hyperplasia, those with hyperplasia more often had chronic inflammation and complete intestinal metaplasia in the junctional biopsies (48% v 77% and 9% v 26%, respectively). Logistic regression analysis revealed that chronic cardiac inflammation (odds ratio (OR), 3.2; 95% confidence interval (CI), 1.3 to 7.8) and intestinal metaplasia of the complete type (OR, 2.8; 95% CI, 1.1 to 7.1) were independent risk factors for cardiac foveolar hyperplasia. In univariate analysis, endoscopic erosive oesophagitis (endoscopy positive gastro-oesophageal reflux disease) and the use of NSAIDs were not related to the presence of foveolar hyperplasia.

CONCLUSIONS

Foveolar hyperplasia in the gastric cardiac mucosa occurs in patients with histologically normal non-gastritic stomachs and may develop as a consequence of chronic inflammation limited to the gastro-oesophageal junction ("junctitis"). It is not associated directly with endoscopy positive gastro-oesophageal reflux disease or the use of NSAIDs.

The effect of Helicobacter pylori eradication on the natural course of atrophic gastritis with dysplasia

BACKGROUND

There are few data on the natural course of Helicobacter pylori-related atrophic gastritis.

AIM

To investigate the effect of H. pylori eradication on advanced atrophic gastritis in the corpus.

METHODS

Twenty-two elderly men with H. pylori infection and moderate or severe atrophic corpus gastritis formed the study population. These men were under endoscopic surveillance because of the presence of indefinite or definite dysplastic gastric lesions in addition to atrophic corpus gastritis. The men were gastroscopically and bioptically examined four times before they received H. pylori eradication therapy (mean follow-up time, 7.5 years), and once again 2.5 years after eradication therapy. Serum levels of pepsinogen I and H. pylori antibodies were analysed at baseline, immediately before and 2.5 years after eradication therapy.

RESULTS

During the 7.5-year period prior to eradication therapy, no significant changes were observed in the mean atrophy and intestinal metaplasia scores or in the mean serum level of pepsinogen I. However, a significant improvement occurred in the mean histological scores of inflammation (from 2.2 to 0.5), atrophy (from 2.2 to 1.2) and intestinal metaplasia (from 1.6 to 1.1) in the corpus mucosa after H. pylori eradication. In addition, the mean serum level of pepsinogen I increased from 16.3 to 25.7 microg/L (P=0.0071, Wilcoxon signed rank test) after eradication therapy.

CONCLUSIONS

The results suggest that advanced atrophic corpus gastritis (and intestinal metaplasia) improves and may even heal after the eradication of H. pylori.

Helicobacter pylori, N-methyl-N'-nitro-N'-nitrosoguanidine, and bile modulate gastric cell kinetics in experimental cancer

Helicobacter pylori infection is a risk factor for gastric cancer. How the bacterium contributes to this process is still unclear. We present a new Wistar rat model that was used to evaluate the effect of H. pylori on early preneoplastic events as judged from epithelial cell turnover and histopathological changes. One hundred and four rats were colonized with H. pylori and exposed MNNG (N-methyl-N'-nitro-N'-nitrosoguanidine) and/or taurocholic acid. Inflammation, goblet cell-like metaplasia, atrophy, dysplasia, and adenocarcinoma were scored in a blinded manner. Apoptotic cells were counted after staining with terminal uridine deoxynucleotidyl nick end labeling, and epithelial cell proliferation was determined by means of the Ki-67 labeling index. No early tumor enhancement with H. pylori could be found in ordinary histology. However, H. pylori significantly enhanced the epithelial cell proliferation compared with the control group, and the combination with taurocholic acid appeared to have a synergistic effect. MNNG significantly increased the normal gastric epithelial apoptosis. This increase was reduced in antral mucosa with H. pylori infection. The findings suggest that H. pylori, especially when combined with bile. has an influence on cell kinetics, contributing to the development of gastric cancer. The reduced apoptosis of MNNG also observed in infected animals indicates a dual function of H. pylori.

Effects of Helicobacter pylori and bile on N-methyl-N'-nitro-N'-nitrosoguanidine exposed antral mucosa of C57BU6 mice

The aim of this study was to evaluate the early influence of Helicobacter pylori infection on cell kinetics in the antral mucosa of mice exposed to N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG) and bile alone or in combinations. Four hundred and one C57BL/6 male and female mice were assigned into seven treatment groups and one non-treated control group. The gastric antrums were assessed by histology and immunohistochemistry for studies of cell proliferation and apoptosis at 32 and 44 weeks. One female and one male mouse had developed dysplastic adenomas in the pylorus mucosa and one male animal had dysplastic proliferation in the antrum. Only one of these lesions occurred in a H. pylori colonized animal. H. pylori infection significantly increased the cell proliferation at 32 weeks and promoted the cell proliferation in the MNNG and bile group at 44 weeks. Female mice showed less increase in cell proliferation than did the males. No change in apoptosis was seen in any of the groups. Bile had no promotional effect on cell proliferation. These results indicate that H. pylori infection has the potential to alter epithelial cell kinetics as well as antrum mucosa of an animal species that is regarded as resistant to MNNG. However, this change is not sufficient to promote the early development of neoplastic lesions.

Gastric carcinoma in young adults

Approximately 10% of gastric cancer cases are found in patients younger than 41 years old. Symptoms of gastric carcinoma are not different from those in the elderly, but because of its relatively uncommon presentation in the young age group, the diagnosis may be delayed. Most of the gastric cancer cases are of diffuse type, and are associated with superficial gastritis. No association is found with intestinal metaplasia. Some gastric cancer cases may, however, develop into histologically normal stomachs. Approximately 10% of young gastric cancer patients have positive family history. In practice, the treatment of gastric cancer is not different between age groups. The same kind of survival is also seen between the age groups after operation if the same tumor stages are compared.

Helicobacter pylori eradication and standardized 3-month omeprazole therapy in functional dyspepsia

OBJECTIVES

The role of Helicobacter pylori in functional dyspepsia remains unclear. This study evaluated the long term consequences for symptoms and quality of life in patients with H. pylori-positive functional dyspepsia after H. pylori eradication therapy with a standardized 3-month omeprazole treatment.

METHODS

A total of 151 H. pylori-positive patients with functional dyspepsia were randomized to receive either eradication therapy or placebo-antibiotics. The initial medication was administered in a double-blinded fashion. In addition, to standardize acid suppression, every patient received omeprazole therapy for the first 3-month period. Dyspeptic symptoms were evaluated by a questionnaire every 3 months, and quality of life was measured by a validated RAND 36-item health survey 1.0 questionnaire at the beginning of the study and after 12 months of follow-up. As the main outcome measure, the scores of patients who had received H. pylori eradication therapy and omeprazole were compared with those who received placebo and omeprazole during the 12 months of follow-up.

RESULTS

A total of 136 patients completed the 1-yr follow-up. In all, 77 patients received eradication therapy and 74 patients remained as controls. After 12 months, the mean reduction in the dyspepsia score was 28.8% in patients with H. pylori eradication therapy and 21.7% in the control group. The reduction of dyspepsia was significant (p < 0.0001) in both groups compared to baseline value, but no statistically significant differences in changes of dyspeptic symptoms or in quality of life were demonstrated between the H. pylori eradication therapy group and controls after 1 yr. In both patient groups, regurgitation (p < 0.001) and heartburn (p < 0.01) revealed relapse after cessation of 3-month omeprazole treatment.

CONCLUSIONS

No clear differences in symptoms or in quality of life were found between patients treated with H. pylori eradication therapy and omeprazole compared with patients receiving placebo and omeprazole after 1 yr. Regardless of H. pylori status, omeprazole treatment reduced heartburn and regurgitation. The placebo effect on the symptoms of functional dyspepsia and on quality of life was marked.

Increased risk of developing atrophic gastritis in patients infected with CagA+ Helicobacter pylori

BACKGROUND

To clarify the possible role of CagA positive (CagA+) Helicobacter pylori strains in the development of atrophic gastritis, the prevalence of antibodies to H. pylori and CagA (120 kD protein) was studied among subjects with atrophic and non-atrophic gastritis.

METHODS

The study population was randomly selected among 12,252 Finnish men who were screened for atrophic corpus gastritis with serum pepsinogen I-assay (S-PGI). S-PGI level was used as a selection criterion. Group A consisted of 295 subjects with S-PGI <25 microg/l (low), group B of 320 subjects with S-PGI 25-100 microg/l (normal) and group C of 338 subjects with S-PGI >100 microg/l (high). Antibodies to H. pylori were measured with EIA and immunoblot analysis and antibodies to CagA with immunoblot analysis. Endoscopical and histological examinations were performed for 203 patients from group A.

RESULTS

The prevalence of antibodies to H. pylori was significantly lower in group B than in groups A or C (P < 0.0001, chi-squared test). There was a significant association between the prevalence of antibodies to CagA and the lowered level of S-PGI (P < 0.0001, Jonckheere-Terpstra trend test). There was also a linear decrease in the prevalence of antibodies to CagA as the atrophic corpus gastritis became more severe (P < 0.0001, linear-by-linear trend test).

CONCLUSION

The presence of antibodies to CagA seems to be associated with development of atrophic corpus gastritis.

Morphometric assessment of gastric antral atrophy: comparison with visual evaluation

AIMS

As part of a multinational effort to reach a consensus in the definition and evaluation of atrophic gastritis, we applied morphometric techniques to 22 antral biopsy specimens examined visually by 12 experienced gastrointestinal pathologists.

METHODS AND RESULTS

Atrophy was defined as loss of glands. Each pathologist graded atrophy with both non-standardized and standardized approaches. Discriminant function analyses of morphometric measurements were conducted to validate and grade atrophy. Kappa statistics were used to compare the performance of each pathologist against the group mode and against the discriminant functions' grading of atrophy. Three morphometric indexes showed significant differences among categories of atrophy utilizing non-standardized as well as standardized visual atrophy grades: (i) the ratio of glandular length to total mucosal thickness; (ii) the proportion of the secretory compartment area occupied by glands; and (iii) the number of glandular cross sections per 40x microscopic field. The discriminant function analyses verified all cases classified visually as either non-atrophic, or moderately/severely atrophic; it verified as mildly atrophic 40% of the cases classified visually as mildly atrophic; and classified the remaining 60% as moderately or severely atrophic. The kappa statistics were good or excellent for the majority of pathologists.

CONCLUSIONS

The evaluation of antral atrophy, simply defined as loss of glands, can be reliable and reproducible. The visual grading of atrophy as absent, moderate and severe is entirely consistent with objective morphometric observations.

Serologic diagnosis of Helicobacter pylori infection in outpatients aged 45 years or less

The diagnostic accuracy of serological tests for Helicobacter pylori was studied in 145 consecutive outpatients aged 45 years or less referred for gastroscopy. Helicobacter pylori infection can be detected by serological tests, including rapid whole-blood tests. The low prevalence of the disease in young people may have a negative effect on the positive predictive value of a test. In this study, the presence of Helicobacter pylori was assessed by a biopsy urease test and histological examination, and by several serological tests: a rapid whole-blood test on fingerstick blood, a latex agglutination serum test, a commercial enzyme immunoassay (EIA) test, and an in-house EIA for detection of antibodies of both the IgG and IgA classes. Helicobacter pylori infection was diagnosed with invasive tests in 21 (14.5%) patients. The sensitivity, specificity, and positive and negative predictive values of the EIA-based tests, compared to histological examination, were 100%, 96-97%, 81-84%, and 100%, respectively. The positive predictive value of the latex agglutination test was 78%, whereas it was only 47% for the whole-blood rapid test used. Although the results of the whole-blood rapid test were unsatisfactory, the quantitative EIA-based tests could reliably detect Helicobacter pylori among young patients, in whom the prevalence of the infection is low.

Impact of non-steroidal anti-inflammatory drug and aspirin use on the prevalence of dyspepsia and uncomplicated peptic ulcer disease

BACKGROUND

Non-steroidal anti-inflammatory drug and aspirin (here collectively called NSAIDs) use is the second most common aetiologic factor for peptic ulcer disease and a major factor for peptic ulcer complications. The role of NSAIDs in the pathogenesis of uncomplicated peptic ulcer is less well understood and the interaction between NSAIDs and Helicobacter pylori infection on ulcer development is controversial. The aim of the present study was to examine the role of NSAIDs in the occurrence and clinical features of uncomplicated peptic ulcer disease.

METHODS

A total of 1091 consecutive patients referred for open-access upper gastrointestinal endoscopy by general practitioners (GPs) were enrolled. The use of NSAIDs was gathered from a structured questionnaire completed by the patients and from patient files by GPs. The exclusion criteria were previous H. pylori eradication and gastric surgery, as well as symptoms and/or signs suggestive of acute gastrointestinal bleeding.

RESULTS

Of the whole study group (n = 1091), 76 (7%) patients had a peptic ulcer. Thirty patients had an NSAID-use-associated peptic ulcer and 46 patients a non-NSAID-use peptic ulcer. Of patients with chronic gastritis (n = 599), 71% were H. pylori-positive and 108 used NSAIDs. Of those with chronic gastritis, 23 had an NSAID-use-associated peptic ulcer and 38 a non-NSAID ulcer. Of patients with normal gastric histology (n = 492), 75 patients used NSAIDs, 7 had an NSAID ulcer and 8 a non-NSAID ulcer. The only independent risk factor for peptic ulcer in patients using NSAIDs was H. pylori infection (odds ratio (OR) 3.1, 95% confidence interval (CI) 1.3-7.3), whereas dyspepsia (OR 1.0, 95% CI 0.4-2.4), male sex (OR 1.4, 95% CI 0.6-3.4), age (OR 1.0 per decade, 95% CI 0.8-1.3) and anaemia (OR 2.9, 95% CI 0.9-8.7) were not risk factors. In patients not using NSAIDs, independent risk factors for peptic ulcer were dyspepsia (OR 4.3, 95% CI 2.1-8.8), male sex (OR 2.0, 95% CI 1.1-2.8), age (OR 1.2 per decade, 95% CI 1.0-1.5), anaemia (OR 6.2, 95% CI 2.6-14.9) and H. pylori infection (OR 7.5, 95% CI 3.4-16.6). When comparing patients using NSAIDs or not, the OR of patients on NSAIDs for peptic ulcer was 2.7 (95% CI 1.5-5.0) among patients with chronic H. pylori gastritis (n = 424) and 5.3 (95% CI 1.8-15.0) among patients with normal gastric mucosa (n = 492).

CONCLUSIONS

The use of NSAIDs increases the risk of peptic ulcer 3- and 5-fold in H. pylori-positive and H. pylori-negative patients, respectively. Dyspepsia is a poor predictor of peptic ulcer among patients using NSAIDs, and serologic H. pylori testing and treatment for chronic NSAID users is recommended.

Expression of cyclooxygenase-2 in dysplasia of the stomach and in intestinal-type gastric adenocarcinoma

PURPOSE

Cyclooxygenase (Cox) is the key enzyme in conversion of arachidonic acid to prostanoids. Two Cox genes have been cloned, and expression of Cox-2 mRNA and protein has been shown to be elevated in several human malignancies and in animal models of carcinogenesis. The purpose of this study was to investigate Cox-2 protein expression in human gastric dysplasias and adenocarcinomas.

EXPERIMENTAL DESIGN

Performance of several Cox-2 antibodies was evaluated, after which Cox-2 protein expression was studied in 67 gastric cancer specimens and in eight definitive dysplasias by using immunohistochemistry.

RESULTS

Cox-2 positivity was detected in 58% (25/43) of the intestinal-type (well-differentiated) tumors and 6% (1/18) of diffuse-type (poorly differentiated) tumors. Consistent with these data, we detected higher expression of Cox-2 mRNA, protein, and enzymatic activity in well-differentiated gastric cancer cell lines (MKN-28 and MKN-74) when compared with poorly differentiated cell lines (HSC-39 and KATO III). Cox-2 immunoreactivity was localized to the carcinoma cells, but the stroma of the tumors was negative. However, strong Cox-2 positivity was consistently detected in stromal cells at sites of erosions and ulcerations. Furthermore, four of nine (44%) definitive dysplasias of the stomach that showed no evidence of invasion were positive for Cox-2.

CONCLUSIONS

Cox-2 is expressed by the neoplastic cells in the intestinal-type gastric adenocarcinoma and by precarcinogenic (dysplastic) lesions leading to this disease.

Update on the pathologic approach to the diagnosis of gastritis, gastric atrophy, and Helicobacter pylori and its sequelae

Biopsy sampling of the gastric mucosa at diagnostic endoscopy provides information that cannot be obtained otherwise. The most common indication for gastric biopsy is the need to know whether the patient is infected with Helicobacter pylori or not and whether the stomach is gastritic or not. Microscopic examination of gastric biopsy specimens gives, in addition to H. pylori status, information about the grade, extent, and topography of gastritis- and atrophy-related alterations in the gastric mucosa. This information provides further possibilities for the assessment of risk and likelihood of various gastric disorders. The presence of atrophy (loss of mucosal glands) results in failures in secretory functions of the corresponding mucosa and leads to errors in the homeostasis of normal gastric physiology. The grade of atrophy of the corpus mucosa linearly correlates with peak and maximal output of acid. The presence of advanced (moderate or severe) corpus atrophy indicates an extremely hypochlorhydric or achlorhydric stomach in which, for example, ordinary peptic ulcer is unlikely or impossible in spite of a possible H. pylori infection. Some well characterized and common topographic phenotypes of H. pylori gastritis and atrophic gastritis can be delineated as follows: Predominance or restriction of the H. pylori-related inflammation in antrum, in association with a nonatrophic corpus mucosa--of which phenotype is the most common--and with an increased risk of peptic ulcer disease, duodenal ulcer in particular ("duodenal ulcer phenotype" of gastritis); the presence of atrophic gastritis in corpus of the stomach ("corpus predominant gastritis"), which indicates a low risk of peptic ulcer and a reduction in the capacity of the patient to secrete acid; the occurrence of advanced atrophic gastritis and intestinal metaplasia multifocally in the stomach (advanced "multifocal atrophic gastritis"), which are features of a gastritis type and which also indicate a low acid secretion capacity and an increased risk of gastric neoplasias ("gastric cancer phenotype of gastritis"), suggesting a need for a careful exclusion of concomitant presence of small focal neoplastic or dysplastic lesions; and the presence of normal and healthy gastric mucosa, which indicates an extremely low risk of both peptic ulcer disease or gastric cancer and, therefore, is a finding of high clinical relevance. The presence of duodenal or gastric ulcer in conjunction with normal, healthy gastric mucosa suggests either aspirin or nonsteroidal antiinflammatory drugs to be the most likely cause of the ulcer.

Seropositivity to Helicobacter pylori heat shock protein 60 is strongly associated with intensity of chronic inflammation, particularly in antrum mucosa: an extension of an 18-year follow-up study of chronic gastritis in Saaremaa, Estonia

Helicobacter pylori is a cause of chronic gastritis and leads to development of atrophy in some cases. There is evidence that the heat shock protein 60 (HSP60) of H. pylori is involved in induction of chronic inflammation. Seroprevalence of IgG antibodies to H. pylori HSP60 in an adult cohort from Saaremaa, Estonia (68 persons, median age 57 years), with a high prevalence of antibodies to cell surface proteins of H. pylori (92%) and a well characterized dynamics of chronic gastritis in an 18-year follow-up study, was tested using purified H. pylori HSP60 at a concentration of 1 microg ml(-1) with ELISA. The state of the gastric mucosa and the presence of H. pylori in histological sections in the samples of 1979 and 1997 were assessed in accordance with the Sydney system. Seropositivity for H. pylori HSP60 was 65%. Immunological response to H. pylori HSP60 is associated with the morphological presence of H. pylori in the antrum and corpus (P=0.01) and is strongly correlated with the grade of chronic inflammation, particularly in the antrum mucosa (r=0.34; P=0.003; OR=5.97 (95% CI 1.21-29.3)), but is not associated with development of atrophy during 18 years of follow-up, or with the activity of gastritis. This finding supports the evidence that immunological response to H. pylori HSP60 may play a role in triggering of the inflammatory process in the gastric mucosa.

Apoptosis in different compartments of antrum and corpus mucosa in chronic Helicobacter pylori gastritis. An 18-year follow-up study

BACKGROUND

The association of apoptosis was analysed in three different compartments (foveolar cells--FC, proliferating zone--PZ and glandular part--GP) of antrum and corpus mucosa specimens with development of atrophy and the extent of apoptosis as depending on grade of chronic inflammation, activity of gastritis and Helicobacter pylori colonization at two time points of an 18-year follow-up in an adult population from Saaremaa, Estonia, with a high prevalence of H. pylori infection were compared.

METHODS

A total of 68 persons (31 men, 37 women; median age, 39 years in 1979) from a primary sample of 304 subjects, endoscoped in 1979 and reinvestigated by endoscopy and biopsy in 1997, were included in the study. The state of the gastric mucosa and the presence of H. pylori in the antrum and corpus mucosa were assessed in accordance with the Sydney system. The dynamics of apoptotic index (AI) between two time points in 1979 and 1997 was evaluated in antrum biopsies of 49 persons and in corpus biopsies of 64 persons. Apoptosis was measured using terminal deoxyuridine nucleotide nick end labelling (TUNEL) histochemistry.

RESULTS

The antrum as well as the corpus of 2/68 persons were H. pylori negative at both time points. Atrophy developed in 9/68 persons in the antrum and in 23/68 in the corpus. In PZ and GP of the corpus mucosa as well as in GP of the antrum mucosa, AI decreased significantly during 18 years compared with initial values (P < 0.05), which was not associated with development of atrophy. In all compartments of the antrum and corpus mucosa, studied at the initial and end points of observation, AI did not reveal a difference in persons with and without development of atrophy (P > 0.05). In the samples of 1979 the highest independent effect on the value of AI in the FC compartment for the antrum was exerted by grade of activity of gastritis (P = 0.01) and in GP by degree of chronic inflammation (P = 0.03), while in the samples of 1997 the highest effect was exerted by grade of H. pylori colonization (P = 0.02 and 0.03 in FC and GP, respectively). For the corpus mucosa AI was most strongly affected also by grade of activity of gastritis in FC compartment (P = 0.02) and by degree of chronic inflammation in PZ (P = 0.04), but not by grade of H. pylori colonization.

CONCLUSION

AI was not associated with development of atrophy, but was largely dependent on grade of activity of gastritis and degree of chronic inflammation; in the antrum mucosa AI depended also on grade of H. pylori colonization.

Favourable effect of an acidified milk (LC-1) on Helicobacter pylori gastritis in man

OBJECTIVE

The supernatant of Lactobacillus johnsonii La1 culture was shown to be bactericidal and to have a partial, acid-independent suppressive effect on Helicobacter pylori in humans. The aim of the present study was to investigate the effect of L. johnsonii La1-acidified milk (LC-1) on H. pylori infection.

DESIGN AND METHODS

Fifty-three volunteers infected with H. pylori as determined by positive 13C-urea breath test and positive serology were randomized to receive either LC-1 or a placebo 180 ml twice a day for 3 weeks. All subjects also received clarithromycin 500 mg bid during the last two weeks of acidified milk therapy. Oesophagogastroduodenoscopy and biopsies were performed at inclusion and repeated 4-8 weeks after the end of the treatment. H. pylori infection was confirmed by urease test and histology. H. pylori density and inflammation were scored using a modified Sydney classification.

RESULTS

LC-1 ingestion induced a decrease in H. pylori density in the antrum (P= 0.02) and the corpus (P= 0.04). LC-1 also reduced inflammation and gastritis activity in the antrum (P= 0.02 and P= 0.01, respectively) and of activity in the corpus (P= 0.02). Clarithromycin eradicated H. pylori in 26% of the subjects; LC-1 did not improve the antibiotic effect.

CONCLUSION

These results suggest that H. pylori infection and gastritis can be down-regulated by LC-1.

Implications of serum pepsinogen I in early endoscopic diagnosis of gastric cancer and dysplasia. Helsinki Gastritis Study Group

BACKGROUND AND AIMS

The risk of gastric cancer (GCA) is increased in atrophic gastritis. A low serum pepsinogen group I (SPGI) level is a good serologic indicator of atrophic gastritis of the gastric corpus and fundus, and can be used for diagnosis of subjects with atrophic gastritis and of increased risk for GCA. The present study was undertaken to investigate whether SPGI assay and a diagnostic gastroscopy could enable the diagnosis of GCA at an early stage.

MATERIAL AND METHODS

The study was carried out as part of the Alpha-Tocopherol, Beta-Carotene Cancer prevention study (ATBC study) in Finland, in which 22,436 male smokers aged 50-69 years were screened by SPGI. Low SPGI levels (< 25 microg/l) were found in 2196 (9.8%) men. Upper GI endoscopy (gastroscopy) was performed in 1344 men (61%) and 78% of these had moderate or severe atrophic corpus gastritis in endoscopic biopsies. A control series of 136 men from the ATBC study cohort with abdominal symptoms, but with SPGI > or = 50 microg/l were similarly endoscopied, and 2.2% of these had corpus atrophy.

RESULTS

Neoplastic alterations were found in 63 (4.7%; 95% CI: 3.6%-5.8%) of the 1344 endoscopied men with low SPGI levels. Of these, 42 were definite dysplasias of low grade, 7 dysplasias of high grade, 11 invasive carcinomas, of which 7 were 'early' cancers, and 3 carcinoid tumors. In the control series, 1 man (0.7%) of the 136 men had a definite low-grade dysplasia. Thus, 18 (1.3%; 95% CI 0.7%-2.0%) cases with 'severe' neoplastic lesions (4 advanced cancers, 7 early cancers and 7 dysplasias of high grade) were found in the low SPGI group, but there were none in the control group. All four patients with advanced cancer died from the malignancy within 5 years (mean survival time 2.5 years), whereas surgical treatment in all those with early cancer or high-grade dysplasia was curative. One of the seven patients with early cancer and two of the seven with high-grade dysplasia died within 5 years, but none died from the gastric cancer. Thus, curative treatment was given to 14 of 18 men in whom a malignant lesion was found in gastroscopy. This is about 15% of all gastric cancer cases (92 cases) which were diagnosed within 5 years after SPGI screening in the 22,436 men. Among the gastric cancer cases of the main ATBC study, the 5-year survival rate was 33% (85% of the non-survivors died from gastric cancer).

CONCLUSIONS

We conclude that assay of SPGI followed by endoscopy is an approach which can enable the early diagnosis of gastric cancer at a curable stage.

Gastritis and gastric cancer. Western countries

Helicobacter pylori infection is the cause of chronic gastritis that progresses to atrophic gastritis over years and decades in more than half of affected individuals. H. pylori gastritis and, particularly, subsequent atrophic gastritis increase the risk for gastric cancer on multifactorial basis. Largely unknown cascades of manifold reactions result in gene errors of epithelial cells in gastric and atrophic stomach, which raise the likelihood of gastric neoplasias and cancer among people infected by H. pylori. The prevalences and incidences of gastric cancer and H. pylori are similarly decreased during the past decades in western countries, supporting the view that H. pylori infection is a key event and a trigger of the phenomena that result in cancer in some of the infected subjects.

Cure of Helicobacter pylori infection after failed primary treatment: one-center results from 120 patients

BACKGROUND

Treatment with a proton pump inhibitor (PPI) and antimicrobials cures Helicobacter pylori infection in about 90% of patients. This is a retrospective overview of our studies aiming to cure the infection in all compliant patients with failed initial therapy.

METHODS

We retreated 120 (19% of 644) H. pylori-infected patients whose initial therapy had failed. The retreatments included (i) triple therapy (TT): colloidal bismuth subcitrate, metronidazole, amoxicillin (or tetracycline); (ii) quadruple therapy (QT): TT and a PPI; or (iii) high doses of both a PPI and clarithromycin combined with a further 1-3 individually selected antimicrobials. The eradication results were determined after 6-12 months.

RESULTS

The 1st retreatment was successful in 70 of 120 patients. The 2nd retreatment cured 25 of the remaining 42 patients, the 3rd 13 of 17, and the 4th the last 4 patients. The cumulative eradication rate (ITT) was 93% (95% CI: 88.9%-97.9%; 8 patients withdrew after a failed 1st retreatment) and the rate was 100% in the remaining 112 patients who accepted several retreatments. The 1st retreatment with TT cured 23% (95% CI: 12%-34%) of 57 patients and QT 85% (95% CI: 74%-96%) of 41 patients who had initially undergone a failed metronidazole-based treatment. All retreatments were well tolerated.

CONCLUSIONS

In this study, high doses of a PPI and clarithromycin combined with 1-3 antimicrobials according to susceptibility data proved to be the best drug combination in the cure of H. pylori infection after failed primary treatment. Giving imidazole- and bismuth-based QT (without clarithromycin) as the first-line treatment of H. pylori infection ensures that the number of failures remains low.