Association between Dietary Salt Intake and Progression in the Gastric Precancerous Process

Development of a gastric cancer risk calculator for questionnaire-based surveillance of Iranian dyspeptic patients

BACKGROUND

Gastric cancer (GC) is considered a silent killer, taking more than three quarters of a million lives annually. Therefore, prior to further costly and invasive diagnostic approaches, an initial GC risk screening is desperately in demand.

METHODS

In order to develop a simple risk scoring system, the demographic and lifestyle indices from 858 GC and 1132 non-ulcer dyspeptic (NUD) patients were analysed. We applied a multivariate logistic regression approach to identify the association between our target predictors and GC versus NUD. The model performance in classification was assessed by receiver operating characteristic (ROC) analysis. Our questionnaire covering 64 predictors, included known risk factors, such as demographic features, dietary habits, self-reported medical status, narcotics use, and SES indicators.

RESULTS

Our model segregated GC from NUD patients with the sensitivity, specificity, and accuracy rates of 85.89, 63.9, and 73.03%, respectively, which was confirmed in the development dataset (AUC equal to 86.37%, P < 0.0001). Predictors which contributed most to our GC risk calculator, based on risk scores (RS) and shared percentages (SP), included: 1) older age group [> 70 (RS:+ 241, SP:7.23), 60-70 (RS:+ 221, SP:6.60), 50-60 (RS:+ 134, SP:4.02), 2) history of gastrointestinal cancers (RS:+ 173, SP:5.19), 3) male gender (RS:+ 119, SP:3.55), 4) non-Fars ethnicity (RS:+ 89, SP:2.66), 5) illiteracy of both parents (RS:+ 78, SP:2.38), 6) rural residence (RS:+ 77, SP:2.3), and modifiable dietary behaviors (RS:+ 32 to + 53, SP:0.96 to 1.58).

CONCLUSION

Our developed risk calculator provides a primary screening step, prior to the subsequent costly and invasive measures. Furthermore, public awareness regarding modifiable risk predictors may encourage and promote lifestyle adjustments and healthy behaviours.

Stomach cancer incidence trends in selected Latin America countries: Age, period, and birth-cohort effects

BACKGROUND

to explore the age, period, and birth-cohort effects on stomach cancer incidence trends during 3 decades in selected Latin American countries.

METHODS

a time-trend study was performed using Cancer Incidence in Five Continents data from high-quality population-based cancer registries(PBCRs) in Latin American countries. Crude and age-standardized incidence rates(ASRIs) were calculated. Time trends in ASRIs were assessed using the average annual percentage change(AAPC). Age-period-cohort effects were estimated by Poisson regression for individuals aged between 20 and 79 years with stomach cancer informed by PBCRs from 1983 to 2012 in Cali(Colombia); from 1982 to 2011 in Costa Rica; and from 1988 to 2012 for Goiania(Brazil) and Quito(Ecuador). The goodness-of-fit model was tested using the deviance of the models.

RESULTS

a decrease in age-standardized incidence rates was observed for both genders in all populations covered by PBCRs, except for young men from Cali(AAPC 3.89 95 %IC: 1.32-7.29). The age effect was statistically significant in all areas, and the curve slope reached peaks in the older age groups. The cohort effect was observed in all PBCRs. Regarding the period effect, an increased ratio rate was observed for both genders in Costa Rica(1997-2001 women RR 1.11 95 %CI: 1.05-1.17; men RR 1.12 95 %CI: 1.08-1.17) and Goiânia(2003-2007 women RR 1.21 95 %CI: 1.08-1.35; men RR 1.09 95 %CI: 1.01-1.20), while Quito(1998-2002 women RR 0.89 95 %CI: 0.81-0.98; men RR 0.86 95 %CI: 0.79-0.93) presented a decrease.

CONCLUSION

the present study showed a decreasing gastric cancer trend for over the past 30 years with gender and geographic variations. Such a decrease seems to be mainly a result of cohort effects, suggesting that the economic market opening process led to changes in the risk factor exposures over successive generations. These geographic and gender variations may reflect cultural/ethnic/gender differences and differences in dietary and smoking rate patterns. However, an increased incidence was observed for young men in Cali, and additional studies are needed to determine the cause of the increasing incidence in this group.

Chinese integrated guideline on the management of gastric precancerous conditions and lesions

The standardized diagnosis and management of gastric precancerous conditions and lesions are important to prevent gastric cancer. This guideline, created by 5 traditional Chinese medicine and Western medicine associations, based on the current morbidity and diagnosis and treatment of gastric precancerous conditions and lesions, provides specific key points and strategies for diagnosis and treatment in the following five aspects: definition and epidemiology, diagnosis and stage, surveillance, treatment and efficacy evaluation. It is hoped that these aspects, assessed by integrating Western medicine and traditional Chinese medicine and involving multidisciplinary participation, will play a guiding role in clinical diagnosis and treatment and achieve effective secondary prevention of gastric cancer.

Isoquinoline Alkaloids from Coptis chinensis Franch: Focus on Coptisine as a Potential Therapeutic Candidate against Gastric Cancer Cells

Gastric cancer (GC) has high incidence rates and constitutes a common cause of cancer mortality. Despite advances in treatment, GC remains a challenge in cancer therapy which is why novel treatment strategies are needed. The interest in natural compounds has increased significantly in recent years because of their numerous biological activities, including anti-cancer action. The isolation of the bioactive compounds from Coptis chinensis Franch was carried out with the Centrifugal Partition Chromatography (CPC) technique, using a biphasic solvent system composed of chloroform (CHCl₃)—methanol (MeOH)—water (H₂O) (4:3:3, v/v) with an addition of hydrochloric acid and trietylamine. The identity of the isolated alkaloids was confirmed using a high resolution HPLC-MS chromatograph. The phytochemical constituents of Coptis chinensis such as berberine, jatrorrhizine, palmatine and coptisine significantly inhibited the viability and growth of gastric cancer cell lines ACC-201 and NCI-N87 in a dose-dependent manner, with coptisine showing the highest efficacy as revealed using MTT and BrdU assays, respectively. Flow cytometry analysis confirmed the coptisine-induced population of gastric cancer cells in sub-G1 phase and apoptosis. The combination of coptisine with cisplatin at the fixed-ratio of 1:1 exerted synergistic and additive interactions in ACC-201 and NCI-N87, respectively, as determined by means of isobolographic analysis. In in vivo assay, coptisine was safe for developing zebrafish at the dose equivalent to the highest dose active in vitro, but higher doses (greater than 10 times) caused morphological abnormalities in larvae. Our findings provide a theoretical foundation to further studies on more detailed mechanisms of the bioactive compounds from Coptis chinensis Franch anti-cancer action that inhibit GC cell survival in in vitro settings.

Dietary Salt Intake and Gastric Cancer Risk: A Systematic Review and Meta-Analysis

The results of prospective cohort studies regarding the role of salt intake and subsequent gastric cancer risk are inconsistent. Thus, we performed a systematic review and meta-analysis to summarize the strength of the association of salt intake with gastric cancer morbidity and mortality. PubMed, EmBase, and Cochrane Library were systematically searched to identify eligible studies published throughout September 2021. The effect estimates with 95% confidence intervals (CIs) for gastric cancer morbidity or mortality in each study were applied to calculate the pooled results; these analyses were performed using the random-effects model. Twenty-six prospective cohort studies involving 4,956,350 individuals were selected; these studies reported 19,301 cases of gastric cancer and 2,871 cases of gastric cancer-associated mortality. High (RR: 1.25; 95%CI: 1.10–1.41; P = 0.001) or moderate (RR: 1.20; 95%CI: 1.04–1.38; P = 0.012) salt intake was associated with a greater risk of gastric cancer. High pickled food intake was associated with an increased gastric cancer risk (RR: 1.28; 95%CI: 1.05–1.57; P = 0.017), while moderate pickled foods intake had no significant effect on gastric cancer risk (RR: 1.10; 95%CI: 0.88–1.37; P = 0.390). Neither high (RR: 1.14; 95%CI: 0.95–1.36; P = 0.161) nor moderate (RR: 1.10; 95%CI: 0.87–1.40; P = 0.436) salted fish intake were associated with gastric cancer risk. A high intake of processed meat was significantly associated with a higher risk of gastric cancer (RR: 1.24; 95%CI: 1.03–1.49; P = 0.023), while moderate processed meat intake had no significant effect on the gastric cancer risk (RR: 1.01; 95%CI: 0.92–1.11; P = 0.844). High (RR: 1.04; 95%CI: 0.90–1.19; P = 0.626) and moderate (RR: 1.02; 95%CI: 0.94–1.11; P = 0.594) miso-soup intake had no effects on the gastric cancer risk. High intakes of salt, pickled food, and processed meat are associated with significantly increased risks of gastric cancer; these increased risks are also seen when participants consumed moderate amounts of salt.

Trends and age-period-cohort analysis of upper aerodigestive tract and stomach cancer mortality in Lithuania, 1987-2016

OBJECTIVES

Lithuania has among the highest mortality rates for upper aerodigestive tract (UADT) and stomach cancer in Europe. The aim of this study was to analyze trends during the period 1987-2016 in Lithuania, evaluating the effect of birth-cohort, period, and age.

STUDY DESIGN

Observational time trends study.

METHODS

Data on numbers of deaths and population size by each calendar year in 5-year age groups in 1987-2016 were obtained from the WHO mortality database. Joinpoint regression analysis was used to evaluate changes in time trends. Age-period-cohort analysis was performed to assess age, calendar period of death, and birth-cohort effects.

RESULTS

UADT cancer mortality in men increased between 1987 and 1993, annual percentage change (APC) = 6.6% (95% confidence interval [CI]: 3.8, 9.4), and was stable thereafter, APC = 0.3% (95% CI: 0.0, 0.6). The age-standardized mortality rate (ASMR) was 23.6/100,000 in 2016. In women, rates increased steadily by 1.6% (95% CI: 0.9%, 2.3%) per year from 1987 to 2016, ASMR = 2.3/100,000 in 2016. Age-period-cohort analysis showed statistically significant cohort effects in both sexes. In men, rates peaked in birth-cohorts born around 1952, declined in 1957-1962 birth-cohorts, and fluctuated in later birth-cohorts. In women, rates started rising in 1947 birth cohort and peaked in the 1967 birth cohort. Stomach cancer mortality declined throughout the study period in men by -2.4%, (95% CI: -2.6%, -2.1%) annually, and women by -2.8% (95% CI: -3.1%, -2.4%), ASMR = 16.1/100,000 and 6.0/100,000 in 2016, respectively. Birth-cohort effects were significant in both sexes. Rates decreased in cohorts born around 1920 onwards, but declines in the youngest generations have slowed in men and reversed in women.

CONCLUSIONS

The birth-cohort effects in UADT and stomach cancer mortality trends imply that the elevated burden in Lithuania could be reduced by effective strategies targeting known risk factors. Further research in causes of unfavorable trends in younger cohorts is warranted.

Dietary Factors and Gastric Intestinal Metaplasia Risk Among US Veterans

BACKGROUND

Studies on diet and gastric intestinal metaplasia (GIM) risk are lacking in US populations.

AIM

To determine the associations of dietary factors and risk of GIM among a US population with typical American diet.

METHODS

We analyzed data from a cross-sectional study of veterans attending primary care and endoscopy clinics at the Houston VA Medical Center. Patients completed a 110-item Block Food Frequency Questionnaire then underwent upper endoscopy with gastric mapping biopsies. We compared cases defined by GIM on ≥ 1 non-cardia gastric biopsy to controls without GIM. Associations of dietary factors and GIM were estimated using logistic regression models as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Among 423 GIM cases and 1796 controls, cases were older (62.1 vs. 59.9 years) and more likely to be male (97.2% vs. 90.8%) and non-White (58.6% vs. 39.0%). GIM cases had lower fat intake (percent kcal from fat tertile 1: 43.6% vs. 33.4%) and higher carbohydrate intake (percent kcal from carbohydrate T3: 41.8% vs. 33.3%) than controls. Adjusting for age, gender, race, smoking, and Helicobacter pylori, percent kcal from carbohydrates (T3 vs. T1: OR 1.35, 95% CI 1.08-1.67), fruit intake (T3 vs. T1: OR 1.28, 95% CI 1.02-1.61), and fiber intake (T3 vs. T1: OR 1.37, 95% CI 1.04-1.80) were associated with GIM. In subgroup analyses, these associations were primarily seen in non-White patients.

CONCLUSIONS

Few dietary factors, including high carbohydrate intake, are associated with increased risk of GIM in US populations, independent of H. pylori or smoking.

Berberine Attenuates Chronic Atrophic Gastritis Induced by MNNG and Its Potential Mechanism

The purpose of this study was to investigate the therapeutic effect of berberine (BBR) on MNNG-induced chronic atrophic gastritis (CAG) and the possible mechanism of BBR through TGF-β1/PI3K signal pathway. GES-1 were pretreated with MNNG for 2 h before BBR treatment in all procedures. Cell viability was quantified by cell counting kit-8, and GES-1 morphology and proliferation were detected by high content screening (HCS) assay. The rat model of CAG was established by MNNG, and the therapeutic effect of BBR on stomach histopathology and serum supernatant were analyzed in vivo. In addition, the possible mechanism of BBR was further discussed, and the expression of related genes and proteins in TGF-β1/PI3K signal pathway was detected. The results showed that BBR could significantly improve the survival rate and morphological changes of GES-1, improve the gastric tissue injury of CAG rats, and reduce the expression of G-17 and inflammatory factors IL-8, TNF-α, IL-6 and IL-1β. In addition, BBR down-regulated the expression of TGF-β1 axis-related signals such as TGF-β1, PI3K, p-Akt/Akt, p-mTOR/mTOR and P70S6K, and promoted the expression of PTEN, LC3-II and Beclin-1. In Conclusion, BBR can improve CAG which may be closely related to TGF-β1/PI3K signal pathway.

Changes of Body Mass Index and Body Shape in relation to risk of Gastric Cancer: A population-based case-control study

Background: The results of previous studies are heterogeneous about the effect of body fatness on risk of gastric cancer (GC). Herein we investigated the effect of changes of BMI and body shape on risk of GC.

Methods: A population-based case-control study enrolled 1989 controls and 937 GC cases. Logistic regression models were used to calculate odd ratios (ORs) and 95% confidence intervals (CIs) for BMI and body shape in association with GC risk, according to anatomical subsite, Laurén's classification, sex and Helicobacter pylori (Hp) infection.

Results: Subjects with higher BMI or body shape 10 years before interview had a lower risk of GC regardless of anatomical subsite, Laurén's classification, and sex (all P for trend <0.05). But the relative risk patterns were different by Hp status. When checking the effect of changes of body fatness, in Hp+ stratum, the ORs (95% CI) were 0.40 (0.17-0.93) for subjects who were underweight at age 20 but had increased BMI afterwards, and 0.48 (0.32-0.73) for those of body shape 1/2 at age 20 but increased body shape subsequently, compared to subjects with stable BMI or body shape. When subjects had a normal BMI or 3/4 body shape at age 20, weight loss nearly doubled the risk of GC, and weight gain would decrease the risk.

Conclusion: The association between body fatness and GC risk might differ by time point of measurement and Hp-infection status. Further, the influence of changes of body fatness might be different by baseline body fatness and Hp-infection status.

Further evidence that methods based on spot urine samples should not be used to examine sodium-disease relationships from the Science of Salt: A regularly updated systematic review of salt and health outcomes (November 2018 to August 2019)

The aim of this eighth Science of Salt outcomes review is to identify, summarize, and critically appraise studies on dietary sodium and health outcomes published between November 1, 2018, and August 31, 2019, to extend this series published in the Journal since 2016. The standardized Science of Salt search strategy was conducted. Studies were screened based on a priori defined criteria to identify publications eligible for detailed critical appraisal. The search strategy resulted in 2621 citations with 27 studies on dietary sodium and health outcomes identified. Two studies met the criteria for detailed critical appraisal and commentary. We report more evidence that high sodium intake has detrimental health effects. A post hoc analysis of the Dietary Approaches to Stop Hypertension (DASH) sodium trial showed that lightheadedness occurred at a greater frequency with a high sodium DASH diet compared to a low sodium DASH diet. In addition, evidence from a post-trial analysis of the Trials of Hypertension (TOHP) I and II cohorts showed that estimates of sodium intake from methods based on spot urine samples are inaccurate and this method alters the linearity of the sodium-mortality association. Compared to measurement of 24-hour sodium excretion using three to seven 24-hour urine collections, estimation of average 24-hour sodium excretion with the Kawasaki equation appeared to change the mortality association from linear to J-shaped. Only two high-quality studies were identified during the review period, both were secondary analyses of previously conducted trials, highlighting the lack of new methodologically sound studies examining sodium and health outcomes.

Gastric cancer prevention strategies: A global perspective

Gastric cancer (GC) is the fifth most common cancer worldwide, and mortality rates are still high. Primary preventive strategies, aimed to reduce risk factors and promote protective ones, will lead to a decrease in GC incidence. Helicobacter pylori infection is a well-established carcinogen for GC, and its eradication is recommended as the best strategy for the primary prevention. However, the role of other factors such as lifestyle, diet, and drug use is still under debate in GC carcinogenesis. Unfortunately, most patients with GC are diagnosed at late stages when treatment is often ineffective. Neoplastic transformation of the gastric mucosa is a multistep process, and appropriate diagnosis and management of preneoplastic conditions can reduce GC-related mortality. Several screening strategies in relation to GC incidence have been proposed in order to detect neoplastic lesions at early stages. The efficacy of screening strategies in reducing GC mortality needs to be confirmed. This review provides an overview of current international guidelines and recent literature on primary and secondary prevention strategies for GC.

Association between interleukin-21 gene rs907715 polymorphism and gastric precancerous lesions in a Chinese population

BACKGROUND

The single nucleotide polymorphisms of interleukin-21 (IL-21) gene were confirmed to be related to various diseases, but no studies have examined the possible role of IL-21 single nucleotide polymorphisms (SNPs) (rs907715, rs2221903, and rs12508721) in gastric precancerous lesions.

AIM

To explore the associations between SNPs of IL-21 gene (rs907715, rs2221903, and rs12508721) and gastric precancerous lesions in a Chinese population.

METHODS

Three SNPs of IL-21 were genotyped using polymerase chain reaction–ligase detection reaction in 588 cases and 290 healthy controls from May 2013 to December 2016 in northwestern China. Gastric precancerous lesions were confirmed by endoscopic examination and categorized as non-atrophic gastritis, atrophic gastritis, and intestinal metaplasia. Descriptive statistic and logistic regression were used for data analyses.

RESULTS

IL-21 rs907715 genotype CC and C frequencies were higher in in patients with gastric precancerous lesions than in the controls (OR = 1.59, 95%CI: 1.06-2.38, P = 0.013; OR = 1.28, 95%CI: 1.01-2.22, P = 0.044, respectively) after adjusting for confounding factors. For SNP rs907715 in intestinal metaplasia patients, significant differences between cases and controls were observed in the frequencies of genotype CC and C (OR = 1.92, 95%CI: 1.24-2.98, P = 0.004; OR = 1.53, 95%CI: 1.04-2.24, P = 0.028, respectively); for non-atrophic gastritis and atrophic gastritis patients, the CC and C genotypes showed no significant association with risk in all models. No association between either rs2221903 or rs12508721 and gastric precancerous lesions was found in the present study. In the haplotype analysis, the TC haplotype (rs907715 and rs12508721) and TT haplotype (rs2221903 and rs907715) were more frequent in the case group than control group (P < 0.05).

CONCLUSION

Our findings indicate that SNP rs907715 of IL-21 gene is associated with gastric precancerous lesions. The TC haplotype (rs907715 and rs12508721) and TT haplotype (rs2221903 and rs907715) increased the risk of gastric precancerous lesions. If confirmed, these findings will shed light on the etiology of precancerous lesions.

Linking gut microbiota with the human diseases

The human gut is rich in microbes. Therefore, it is of interest to document data to link known human diseases with the gut microbiota. Various factors like hormones, metabolites and dietary habitats are responsible for shaping the microbiota of the gut. Imbalance in the gut microbiota is responsible for the pathogenesis of various disease types including rheumatoid arthritis, different types of cancer, diabetes mellitus, obesity, and cardiovascular disease. We report a review of known data for the correction of dysbiosis (imbalance in microbe population) towards improved human health.

A current clinical overview of atrophic gastritis

Introduction: Atrophic gastritis (AG) is a complex syndrome which arises as a consequence of H. pylori infection or in the context of gastric autoimmunity. It often deserves a benign course but may lead to potentially life-threatening complications: cancer and anemia. This review aims to address traditional and innovative knowledge on this often under-diagnosed disorder.Areas covered: This review covers clinical presentation, risk factors, diagnosis, and management of AG and provides an updated resource for clinicians to get insight into this challenging disorder. Updated literature was searched in PubMed. Manual search from reference lists of publications was performed.Expert opinion: A case-finding strategy may be beneficial in individuals with anemia, dyspepsia, autoimmune thyropaties and type 1 diabetes, and family history of gastric cancer. AG is linked to gastric cancer risk and endoscopic surveillance is indicated according to topography of gastric atrophy and risk factors. The direction for future research in AG is summarized.

Estimation of salt intake from spot urine may assist the risk assessment of gastric cancer

Daily salt intake can be estimated by measuring sodium and creatinine concentrations in spot urine. Excessive salt intake is risk factor for gastric cancer. We examined the correlation between estimated salt intake from spot urine and risk of gastric cancer. This study included gastric cancer patients who underwent treatment at our hospital and patients in whom esophagogastroduodenoscopy was performed but gastric cancer was not observed. The history of H. pylori infection was known in these patients. Spot urine was collected, and daily salt intake was estimated from urine sodium and urine creatinine. Mean estimated salt intake was significantly higher in 120 gastric cancer patients (9.18 g/day) than in 80 non-gastric cancer patients (8.22 g/day). Multivariate analysis revealed estimated salt intake and H. pylori infection to be independent risk factors for gastric cancer. Among H. pylori-infected patients, salt intake was significantly higher in gastric cancer patients (9.25 g/day) than in non-gastric cancer patients (8.01 g/day). In conclusion, salt intake estimated from spot urine was high in patients with gastric cancer, especially in H. pylori infected patients. Spot urine is a simple examination and it may be applied as a new risk assessment of gastric cancer.

Association of dietary patterns and endoscopic gastric mucosal atrophy in an adult Chinese population

Atrophy gastritis harbor a high risk for the development of dysplasia and gastric cancer. The study investigated the relationships of specific dietary patterns and endoscopic gastric mucosal atrophy. In this cross-sectional study, we enrolled 574 consecutive outpatients who were diagnosed as chronic gastritis according to endoscopic examination. Dietary intakes of study individuals was assessed using the semi-quantitative food group frequency questionnaire. Logistic regression analyses were used to evaluate the relationship between dietary patterns and endoscopic gastric mucosal atrophy adjusted for potential confounders. A total of 574 participants were included, 286 with endoscopic gastric mucosal atrophy. Three dietary patterns were identified by factor analysis. “Alcohol and fish” (tertile 1 vs. tertile 3: adjusted odds ratio = 1.85, 95% confidence interval: 1.06–3.22) and “coarse cereals” (tertile 1 vs. tertile 3: adjusted odds ratio = 2.05, 95% confidence interval: 1.24–3.39) were associated with an increased risk for endoscopic gastric mucosal atrophy but a “traditional” pattern was not. Dietary pattern was not associated with gastric mucosal atrophy in women or in participants with H. pylori infection. A high adherence to both “Alcohol and Fish” and “Coarse cereals” dietary patterns seem to be associated with higher odds of endoscopic gastric mucosal atrophy in men and in patients without H. pylori infection. Further prospective cohort studies needed to confirm these findings.

The Association between Salt and Potential Mediators of the Gastric Precancerous Process

Background: The process by which salt affects the gastric precancerous process has not been adequately studied in humans. Methods: We investigated the effects of salt on gastric inflammation, epithelial damage, the density of Helicobacter pylori infection, and gastric epithelial cell proliferation, all of which may be mediators between salt and gastric precancerous/cancerous lesions. These potential mediators were measured using gastric biopsies as: (a) the density of polymorphonuclear and mononuclear cells (gastric inflammation), (b) mucus depletion (gastric epithelial damage), and (c) the severity of H. pylori infection. Salt intake was measured with spot urine samples (using urinary sodium/creatinine ratios), self-reported frequency of adding salt to food, and as total added salt. Results: The average sodium/creatinine ratio (at baseline and post-treatment at five months) was associated with increased epithelial damage over the 12-year follow-up period among those with a greater severity of chronic inflammation and among those with continued H. pylori infection after treatment at five months. This association was stronger when both severe gastric inflammation and H. pylori infection were present at five months (ß: 1.112, 95% CI: 0.377, 1.848). Conclusion: In humans, salt was associated with an increase in epithelial damage in stomachs with more severe previous H. pylori-induced chronic inflammation.