High acid secretion may protect the gastric mucosa from injury caused by ammonia produced by Helicobacter pylori in duodenal ulcer patients

The aim of the present study was to investigate the mechanism by which gastric atrophy does not tend to occur in patients with duodenal ulcer despite frequent Helicobacter pylori infection. This investigation was performed in 60 patients with duodenal ulcer and 63 age-matched gastritis patients. Endoscopic findings in the antrum and corpus were classified as normal, atrophic and superficial changes. Biopsy specimens were taken from the antrum and corpus. Ninety per cent of patients with duodenal ulcer and 63.5% of patients with gastritis had H. pylori infection (P<0.01). The incidence of normal findings in duodenal patients was 30% in antral regions and 50% in the corpus (P<0.05). Atrophic change was observed in 21.7% of patients in the antrum and 3.3% of patients in the corpus (P<0.01). The grade of inflammation in duodenal ulcer specimens was significantly higher in the antrum than in the corpus (P<0.01). >H. pylori density was significantly higher in the antrum than in the corpus in ulcer patients (P<0.01). No significant difference in endoscopic findings, >H. pylori density or the grade of inflammation was found between the antrum and corpus in patients with gastritis. The mean intragastric ammonia concentration was 10.3 mg/dL in duodenal ulcer patients and 6.2 mg/dL in gastritis patients (P<0.01). The mean pH was 3.5 and 4.6 in ulcer and gastritis specimens, respectively (P<0.01). Our data suggest that gastric mucosa injury is less frequently associated with duodenal ulcers than with gastritis due to the low >H. pylori density in the corpus and to the higher acid output that neutralizes the ammonia produced by H. pylori.     

Helicobacter pylori-induced inflammation and epigenetic changes during gastric carcinogenesis

The sequence of events associated with the development of gastric cancer has been described as “the gastric precancerous cascade”. This cascade is a dynamic process that includes lesions, such as atrophic gastritis, intestinal metaplasia and dysplasia. According to this model, Helicobacter pylori (H. pylori) infection targets the normal gastric mucosa causing non-atrophic gastritis, an initiating lesion that can be cured by clearing H. pylori with antibiotics or that may then linger in the case of chronic infection and progress to atrophic gastritis. The presence of virulence factors in the infecting H. pylori drives the carcinogenesis process. Independent epidemiological and animal studies have confirmed the sequential progression of these precancerous lesions. Particularly long-term follow-up studies estimated a risk of 0.1% for atrophic gastritis/intestinal metaplasia and 6% in case of dysplasia for the long-term development of gastric cancer. With this in mind, a better understanding of the genetic and epigenetic changes associated with progression of the cascade is critical in determining the risk of gastric cancer associated with H. pylori infection. In this review, we will summarize some of the most relevant mechanisms and focus predominantly but not exclusively on the discussion of gene promoter methylation and miRNAs in this context.     

Link betweenHelicobacter pylori-associated gastritis and duodenal ulcer

We examined the interrelationships among the degree of fundic mucosal atrophy, the prevalence ofHelicobacter pylori in the gastric antrum, the gastric juice, and the duodenum with and without gastric metaplasia, in 20 duodenal ulcer patients and 20 non-duodenal ulcer patients. The detection rates ofH. pylori in the antrum, the gastric juice, and the duodenum were significantly higher in duodenal ulcer patients (80%, 65%, and 60%) than in non-duodenal ulcer subjects (50%, 20%, and 5%). The frequency ofH. pylori was significantly lower in the gastric juice (30%) and the duodenum (10%) in non-duodenal ulcer patients with antralH. pylori, compared with those in duodenal ulcer patients with antralH. pylori. All of seven patients with both gastric metaplasia andH. pylori infection in the duodenum had duodenal ulcer, whereas only 1 of 14 patients without either gastric metaplasia orH. pylori infection in the duodenum had duodenal ulcer. There was normal or mild atrophic mucosa in the fundus of duodenal ulcer patients withH. pylori in the antrum, whereas moderate or severe atrophic mucosa in non-duodenal ulcer patients withH. pylori gastritis. These results suggest that the preserved fundic mucosa, gastric metaplasia in the duodenum, and a greater load ofH. pylori to the duodenum through the gastric juice may be prerequisites for the formation of duodenal ulcers.     

The prevalence of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> in Japanese children with gastritis or peptic ulcer disease

Background Although Helicobacter pylori infection is typically acquired in childhood, the role of H. pylori infection in gastroduodenal diseases in childhood remains to be defined. The purpose of this study was to evaluate the prevalence of H. pylori infection in children with gastritis, duodenal ulcer, and gastric ulcer.Methods This was a retrospective analysis of 283 Japanese children (mean age, 11.5 years) with non-nodular gastritis (n = 73), nodular gastritis (n = 67), duodenal ulcer (n = 100), and gastric ulcer (n = 43). H. pylori status was based on biopsy tests. Clinical symptoms at the time of endoscopy were analyzed with regard to a possible association with the infection.Results The prevalence of H. pylori in non-nodular gastritis, nodular gastritis, duodenal ulcer, and gastric ulcer was 28.8%, 98.5%, 83.0%, and 44.2%, respectively. H. pylori was significantly linked to duodenal ulcer and gastric ulcers in the age group of 10–16 years, but not in the age group of 9 years and under. In children with H. pylori infection, nodular gastritis was observed in 26.3% of gastric ulcer patients and in 74.7% of duodenal ulcer patients (P < 0.001). H. pylori infection was significantly associated with the prevalence of anemia (P < 0.05).Conclusions H. pylori is the most important causal factor for the development of duodenal ulcer in childhood. While H. pylori infection appears to be a risk factor in gastric ulcer, other causes are responsible for most cases. Nodular gastritis is the most common type of H. pylori gastritis in childhood. Chronic infection with H. pylori is associated with anemia.     

Helicobacter pylori associated chronic gastritis,clinical syndromes,precancerous lesions,and pathogenesis of gastric cancer development

Helicobacter pylori(H.pylori)infection is well known to be associated with the development of precancerous lesions such as chronic atrophic gastritis(AG),or gastric intestinal metaplasia(GIM),and cancer.Various molecular alterations are identified not only in gastric cancer(GC)but also in precancerous lesions.H.pylori treatment seems to improve AG and GIM,but still remains controversial.In contrast,many studies,including meta-analysis,show that H.pylori eradication reduces GC.Molecular markers detected by genetic and epigenetic alterations related to carcinogenesis reverse following H.pylori eradication.This indicates that these changes may be an important factor in the identification of high risk patients for cancer development.Patients who underwent endoscopic treatment of GC are at high risk for development of metachronous GC.A randomized controlled trial from Japan concluded that prophylactic eradication of H.pylori after endoscopic resection should be used to prevent the development of metachronous GC,but recent retrospective studies did not show the tendency.Patients with precancerous lesions(molecular alterations)that do not reverse after H.pylori treatment,represent the"point of no return"and may be at high risk for the development of GC.Therefore,earlier H.pylori eradication should be considered for preventing GC development prior to the appearance of precancerous lesions.     

Size of the peptic ulcer in Helicobacter pylori-positive patients: association with the clinical and histological characteristics

Objective. Based on a large trial of Helicobacter pylori-positive peptic ulcer patients, we studied whether the size of the ulcer, along with other clinical and histological characteristics, has any effect on healing. We also studied the clinical and endoscopic characteristics associated with size of the peptic ulcer. Material and methods. A total of 333 consecutive patients with H. pylori infection and peptic ulcer were enrolled (mean age 54.8±12.7 years). Location of the ulcer was recorded by gastroscopy and the presence of H. pylori was assured by rapid urease test, histology and by serum H. pylori IgG and IgA antibody measurement. The diameter of the ulcer was measured by placing the opened biopsy forceps (7 mm) beside it. Biopsy specimens were examined in accordance with the Sydney system. Results. Mean size of the peptic ulcer was 13.2±8.3 in corpus, 11.3±5.3 in antrum, 13.8±7.8 in angulus, 9.5±5.3 in prepylorus and 9.2±4.7 mm in duodenum (duodenal versus gastric type; p<0.05). Average size of the ulcers was 9.4±5.3 mm in patients with Forrest III type and 11.5±6.8 in other types (p<0.05). Patients who were ≥50 years of age, currently smoking, or who had corpus-predominant chronic gastritis or atrophic gastritis, had larger ulcers than others. Size of index ulcers, successful eradication of H. pylori and the presence of atrophic gastritis were independent factors for healing. The odds ratio was 11.5 (95% CI 3.3–40.5; p<0.01) for eradication of H. pylori, 3.5 (95% CI 1.1–11.2; p<0.05) for size of the index ulcer (≤10 mm versus >10 mm) and 3.4 (95% CI 1.2–9.8; p<0.05) for atrophic gastritis versus no atrophy. Conclusions. Size of the peptic ulcer, successful H. pylori eradication and atrophic gastritis were independent factors for the healing of peptic ulcers. A number of clinical and endoscopic variables (age, current smoking, corpus-predominant gastritis, Forrest classification) were associated with size of the peptic ulcer in H. pylori-positive patients.     

DNA-DNA hybridization demonstrates apparent genetic differences betweenHelicobacter pylori from patients with duodenal ulcer and asymptomatic gastritis

We asked whether different clinical outcomes ofHelicobacter pylori infection might be a reflection of genetic differences in infecting organisms. Using DNA-DNA hybridization we examined whether hybridization levels groupedH. pylori isolates corresponding to the type of disease (gastric ulcer, duodenal ulcer, asymptomatic gastritis) from which they were recovered. Target DNAs were prepared fromH. pylori strains cultured from gastric biopsy specimens of 25 patients; 5 with gastric ulcers, 9 with duodenal ulcers, and 11 from asymptomatic volunteers endoscopically proven not to have peptic ulcer disease. DNA-DNA hybridization was performed with whole genomic probes made from an isolate from each of the three disease categories. Using a DNA probe from an isolate from a duodenal ulcer patient, we found that isolates from patients with duodenal ulcer and nonulcer gastritis yielded significant differences in levels of hybridization. The levels of hybridization of DNA fromH. pylori isolates from duodenal ulcer patients, gastric ulcer patients and nonulcer gastritis controls were 85.5%±7%, 83%±3%, and 78.3%±5%, respectively (mean±sd), and the difference between the hybridization levels obtained with duodenal ulcer and nonulcer control target DNAs was statistically significant (P=0.025). These data suggest that the outcome of infection (eg, ulcer or no ulcer) may be due to virulence factors encoded by genomic DNA. If such differences exist, it should be possible to produce probes that would identify the ulcer virulence gene(s) and clearly distinguish between ulcerogenic and nonulcerogenic strains ofH. pylori.This work was supported by Veterans Affairs; by grant DK 39919 from the National Institute of Diabetes and Digestive and Kidney Diseases and by the generous support of Hilda Schwartz.     

Gastric emptying andHelicobacter pylori infection in duodenal ulcer disease

The pathogenetic link betweenHelicobacter pylori gastritis and duodenal ulcer is still unknown. Fast gastric emptying of liquids might be important in the pathogenesis of gastric metaplasia of the duodenum and duodenal ulcer through an increased exposure of the duodenum to gastric acid. InH. pylori-infected subjects, an abnormal gastric emptying could affect urea breath test results and correlate with the histological gastritis. This study was performed to evaluate the gastric emptying of liquids in duodenal ulcer patients withH. pylori infection and the possible relation between the bacterial load, gastric emptying, and urea breath test results. Seventeen duodenal ulcer patients withH. pylori gastritis and 15 healthy volunteers were studied by a combined [¹⁴C]octanoic acid and [¹³C]urea breath test to evaluate gastric emptying rate andH. pylori status simultaneously. Endoscopy with antral biopsies was performed in all duodenal ulcer patients. Duodenal ulcer patients withH. pylori infection have a normal liquid gastric emptying that is unrelated with the histological severity of gastritis. The urea breath test results and the gastric emptying parameters do not correlate with histology. A significant correlation between the gastric emptying and the urea hydrolysis rate is found. It is concluded thatH. pylori infection in duodenal ulcer patients is not associated with abnormally fast liquid gastric emptying, and this finding should be taken into account when a causal link betweenH. pylori infection and duodenal ulcer disease is searched for. The correlation between gastric emptying and urea hydrolysis rate explains why no conclusions on intragastric bacterial load can be drawn from the urea breath test results.This study was presented in part as an oral communication at the Annual Meeting of the American Gastroenterological Association, May 1994, New Orleans, and published in abstract form inGastroenterology 106:A160, 1994.     

Incidence of duodenal ulcers and gastric ulcers in a Western population: Back to where it started

BACKGROUND/OBJECTIVES:

As recently as 40 years ago, a decline in the incidence of peptic ulcers was observed. The discovery of Helicobacter pylori had a further major impact on the incidence of ulcer disease. Our aim was to evaluate the trends in the incidence and bleeding complications of ulcer disease in the Netherlands.

METHODS:

From a computerized endoscopy database of a district hospital, the data of all patients who underwent upper gastrointestinal endoscopy from 1996 to 2005 were analyzed. The incidence of duodenal and gastric ulcers, with and without complications, were compared over time.

RESULTS:

Overall, 20,006 upper gastrointestinal endoscopies were performed. Duodenal ulcers were diagnosed in 696 (3.5%) cases, with signs of bleeding in 158 (22.7%). Forty-five (6.5%) of these ulcers were classified as Forrest I and 113 (16.2%) as Forrest II. Gastric ulcers were diagnosed in 487 cases (2.4%), with signs of bleeding in 60 (12.3%). A Forrest 1 designation was diagnosed in 19 patients (3.9%) and Forrest 2 in 41 patients (8.4%). The incidence of gastric ulcers was stable over time, while the incidence of duodenal ulcers declined.

CONCLUSIONS:

The incidence of duodenal ulcer disease in the Dutch population is steadily decreasing over time. Test and treatment regimens for H pylori have possibly contributed to this decline. With a further decline in the prevalence of H pylori, the incidence of gastric ulcers is likely to exceed the incidence of duodenal ulcers in the very near future, revisiting a similar situation that was present at the beginning of the previous century.     

Endoscopic characteristics and Helicobacter pylori infection in NSAID-associated gastric ulcer

Background and Aim: Helicobacter pylori infection and non‐steroidal anti‐inflammatory drugs (NSAIDs) are deeply involved in the etiology of gastric ulcers. The aim of our study was to clarify the endoscopic characteristics and H. pylori infection status of NSAID‐associated gastric ulcers. Methods: The study group comprised 50 patients (23 men, 27 women; mean age 66.5 years) with NSAID‐associated gastric ulcers and 100 sex‐ and age‐matched patients with gastric ulcer associated with other factors (control group). Ulcer morphology, size and number of lesions, onset site and incidence of hemorrhagic ulcers were investigated endoscopically in both groups. H. pylori infection was diagnosed by serology, histology and ¹³C‐urea breath test. Results: Multiple lesions (68% vs 20%, P < 0.001), occurrence in the antrum (56% vs 6%, P < 0.001), and hemorrhagic ulcer (34% vs 4%, P < 0.001) were significantly more prevalent in patients with NSAID‐associated gastric ulcers than in patients with non‐NSAID‐associated gastric ulcer. The H. pylori infection rate was significantly lower in NSAID‐associated gastric ulcer patients than in non‐NSAID‐associated gastric ulcer patients (48% vs 96%, P < 0.001). In the NSAID‐associated gastric ulcer group, the prevalence of H. pylori infection was significantly lower in patients with ulcers in the antrum than in those with ulcers in the angulus or corpus (25% vs 77.3%, P < 0.001). Conclusions: In contrast to non‐NSAID‐associated gastric ulcers, NSAID‐associated gastric ulcers frequently occur in the antrum with bleeding. The rate of H. pylori infection in NSAID‐associated gastric ulcers is significantly lower than that in non‐NSAID‐associated gastric ulcers.     

Gastric precancerous lesions are associated with gene variants in Helicobacter pylori -susceptible ethnic Malays

AIM: To identify genes associated with gastric pre-cancerous lesions in Helicobacter pylori (H. pylori )susceptible ethnic Malays. METHODS: Twenty-three Malay subjects with H. pylori infection and gastric precancerous lesions identified during endoscopy were included as "cases". Thirtyseven Malay subjects who were H. pylori negative and had no precancerous lesions were included as "controls". Venous blood was collected for genotyping with Affymetrix 50K Xba1 kit. Genotypes with call rates < 90% for autosomal single nucleotide polymorphisms (SNPs) were excluded. For each precancerous lesion, associated SNPs were identified from Manhattan plots, and only SNPs with a χ2 P value < 0.05 and Hardy Weinberg Equilibrium P value > 0.5 was considered as significant markers. RESULTS: Of the 23 H. pylori -positive subjects recruited, one sample was excluded from further analysis due to a low genotyping call rate. Of the 22 H. pylori positive samples, atrophic gastritis only was present in 50.0%, complete intestinal metaplasia was present in 18.25%, both incomplete intestinal metaplasia and dysplasia was present in 22.7%, and dysplasia only was present in 9.1%. SNPs rs9315542 (UFM1 gene), rs6878265 (THBS4 gene), rs1042194 (CYP2C19 gene) and rs10505799 (MGST1 gene) were significantly associated with atrophic gastritis, complete intestinal metaplasia, incomplete metaplasia with foci of dysplasia and dysplasia, respectively. Allele frequencies in "cases" vs "controls" for rs9315542, rs6878265, rs1042194 and rs10505799 were 0.4 vs 0.06, 0.6 vs 0.01, 0.6 vs 0.01 and 0.5 vs 0.02, respectively. CONCLUSION: Genetic variants possibly related to gastric precancerous lesions in ethnic Malays susceptible to H. pylori infection were identified for testing in subsequent trials.     

Non-microbial approach for Helicobacter pylori as faster track to prevent gastric cancer than simple eradication

Although the International Agency for Research on Cancer declared Helicobacter pylori(H.pylori)as a definite human carcinogen in 1994,the Japanese Society for Helicobacter Research only recently(February 2013)adopted the position that H.pylori infection should be considered as an indication for either amelioration of chronic gastritis or for decreasing gastric cancer mortality.Japanese researchers have found that H.pylori eradication halts progressive mucosal damage and that successful eradication in patients with non-atrophic gastritis most likely prevents subsequent development of gastric cancer.However,those who have already developed atrophic gastritis/gastric atrophy retain potential risk factors for gastric cancer.Because chronic perpetuated progression of H.pylori-associated gastric inflammation is associated with increased morbidity culminating in gastric carcinogenesis,a non-microbial approach to treatment that provides long-term control of gastric inflammation through nutrients and other interventions may be an effective way to decrease this morbidity.This non-microbial approach might represent a new form of prerequisite"rescue"therapy that provides a quicker path to the prevention of gastric cancer as compared to simple eradication.     

Helicobacter pylori eradication and reflux disease onset:Did gastric acid get "crazy"?

Gastroesophageal reflux disease (GORD) is highly prevalent in the general population.In the last decade,a potential relationship between Helicobacter pylori (H.pylori) eradication and GORD onset has been claimed.The main putative mechanism is the gastric acid hypersecretion that develops after bacterial cure in those patients with corpus-predominant gastritis.We performed a critical reappraisal of the intricate pathogenesis and clinical data available in this field.Oesophagitis onset after H.pylori eradication in duodenal ulcer patients has been ascribed to a gastric acid hypersecretion,which could develop following body gastritis healing.However,the absence of an acid hypersecretive status in these patients is documented by both pathophysiology and clinical studies.Indeed,duodenal ulcer recurrence is virtually abolished followingH.pylori eradication.In addition,intra-oesophageal pH recording studies failed to demonstrated increased acid reflux following bacterial eradication.Moreover,oesophageal manometric studies suggest that H.pylori eradication would reduce-rather than favor-acid reflux into the oesophagus.Finally,data of clinical studies would suggest that H.pylori eradication is not significantly associated with eitherreflux symptoms or erosive oesophagitis onset,some data suggesting also an advantage in curing the infection when oesophagitis is already present.Therefore,the legend of "crazy acid" remains-as all the others a fascinating,but imaginary tale.     

Clinical significance of white gastric crypt openings observed via magnifying endoscopy

AIM:To evaluate the relationship between Helicobacter pylori(H.pylori)-induced gastritis and white gastric mucosal crypt openings(COs)in the gastric corpus.METHODS:A total of 175 consecutive patients(including 69 patients with gastric cancer)were enrolled in this study.We used magnifying endoscopy(ME)to observe the mucosa microsurface of the lesser and greater curvature of the gastric corpus(350 areas in all).We focused on areas with a round pit microstructure(primarily observed in non-atrophied areas)and evaluated the white openings of these gastric pits.We classified the whiteness of the COs as the"white-edged dark spot"type(consisting of a dark spot bordered by white);the"white"type(pure white with no dark spot);and the"dense white pit(DWP)"type(dense white,resembling a snowball).Gastritis was also histologically evaluated according to the updated Sydney System.RESULTS:We detected round COs using ME in 246 of the 350 areas examined.The histological examination showed significantly more mononuclear cells and neutrophil infiltration in the"white"and"DWP"types than the"white-edged dark spot"type(P<0.001).Furthermore,significantly high-grade inflammation and evidence of active H.pylori-induced gastritis was observed in the"DWP"type(P<0.001).Significant differences were observed in the whiteness of COs between H.pylori-positive(n=139)and negative(n=36)patients(P<0.001).The sensitivity and specificity of the"white"and"DWP"types for predicting H.pylori infection were78.5%and 81.7%,respectively.Of the patients with gastric cancer,22.5%(18/80)had"white-edged dark spots",51.3%(41/80)had"white"COs,and 26.3%(21/80)had"DWP"-type COs."DWPs"were frequently observed among patients with undifferentiated gastric cancer[45.7%(16/35)].CONCLUSION:CO whiteness detected via ME was associated with histological evidence of gastritis and helps to predict the severity of inflammation and H.pyloriinduced activity.     

Helicobacter pylori in duodenal ulcer patients with idiopathic gastric acid hypersecretion

Thirty-three consecutive patients with idiopathic gastric acid hypersecretion (defined as a basal acid output >10.0 meq/hr with a normal fasting serum gastrin level and negative secretin stimulation test) who were being treated for duodenal ulcer disease and other acid-peptic disorders were evaluated for the presence ofHelicobacter pylori by means of a rapid urease test. Fourteen patients had duodenal ulcer and 19 had other acid-peptic disorders (gastroesophageal reflux in 14, including six with Barrett's esophagus; four with nonulcer dyspepsia; and one with erosive gastritis).Helicobacter pylori was present in 12 of the 14 ulcer patients (86%) compared to only two of the 19 nonulcer patients (11%) (P<0.0001). The distribution of basal acid output for patients with duodenal ulcer was similar to that for nonulcer patients, and no significant difference in the mean basal acid output was found amongHelicobacter pylori-positive compared toHelicobacter pylori-negative patients. Seven of the duodenal ulcer patients with a basal acid output greater than 15.0 meq/hr wereHelicobacter pylori-positive, suggesting that the organism can withstand even extreme levels of gastric acidity. In conclusion, this study demonstrates that the prevalence ofHelicobacter pylori infection in patients with duodenal ulcer disease associated with idiopathic gastric acid hypersecretion is not different from a majority of ulcer patients with normal acid secretory profiles and offers additional evidence that extreme levels of gastric acid are not bactericidal for the organism.     

Management of Helicobacter pylori infection after gastric surgery

The Maastricht IV/Florence Consensus Report and the Second Asia-Pacific Consensus Guidelines strongly recommend eradication of Helicobacter pylori(H.pylori)in patients with previous gastric neoplasia who have undergone gastric surgery.However,the guidelines do not mention optimal timing,eradication regimens,diagnostic tools,and follow-up strategies for patients undergoing gastrectomy and do not indicate if eradication of H.pylori reduces the risk of marginal ulcer or stump cancer in the residual stomach after gastrectomy.The purpose of this review is to provide an update which may help physicians to properly manage H.pylori infection in patients who have undergone gastric surgery.This review focuses on(1)the microenvironment change in the stomach after gastrectomy;(2)the phenomenon of spontaneous clearance of H.pylori after gastrectomy;(3)the effects of H.pylori on gastric atrophy and intestinal metaplasia after gastrectomy;(4)incidence and clinical features of ulcers developing after gastrectomy;(5)does eradication of H.pylori reduce the risk of gastric stump cancer in the residual stomach?(6)does eradication of H.pylori reduce the risk of secondary metachronous gastric cancer in the residual stomach?and(7)optimal timing and regimens for H.pylori eradication,diagnostic tools and follow-up strategies for patients undergoing gastrectomy.     

Comparison of sequential and 7-, 10-, 14-d triple therapy for Helicobacter pylori infection

AIM: To compare the effectiveness of sequential therapy for Helicobacter pylori (H. pylori) infection with that of triple therapy of varying durations.METHODS: The 460 patients enrolled in this study had H. pylori-associated gastritis or a gastric or duodenal ulcer. After screening, H. pylori-infected patients were randomly assigned to receive either conventional triple therapy for 7, 10 or 14 d, or a new 10-d sequential therapy. Each of the 4 treatment groups included 115 patients. The outcomes of eradication therapy were assessed 4 wk after treatment by the urea breath test and histology.RESULTS: The overall eradication rate was 81.0%, and eradication rates were 75.7% for 7-d conventional triple therapy, 81.9% for 10-d conventional triple therapy, 84.4% for 14-d conventional triple therapy, and 82.0% for 10-d sequential therapy. Neither intention-to-treat analysis nor per protocol analysis showed significant differences in eradication rates using sequential therapy or the standard triple therapy (P = 0.416 and P = 0.405, respectively).CONCLUSION: There are no significant differences between 10-d sequential eradication therapy for H. pylori and any duration of standard triple treatment in Korean patients.     

vacA genotypes of Helicobacter pylori in the oral cavity and stomach of patients with chronic gastritis and gastric ulcer

Introduction

Helicobacter pylori adheres to various components of the human saliva. Therefore, the objective of this research was to simultaneously detect H. pylori in saliva and in gastric biopsy, and to determine the agreement between the vacA genotypes in both saliva and gastric biopsy.

Materials and methods

A total of 162 patients with chronic gastritis and 34 with gastric ulcer were studied, and saliva and biopsy samples were collected from each patient. H. pylori DNA was detected by conventional PCR and nested PCR was used for vacA genotyping.

Results

In 24% of the patients (47/196) H. pylori DNA was found in saliva and in biopsy; 52.5% (103/196) were saliva^negative/biopsy^positive and 6.6% (13/196) were saliva^positive/biopsy^negative. In either or both H. pylori vacAs1m1 or s1m2 genotypes were detected in saliva in 41.5% of the patients with chronic gastritis. Forty-seven percent had >1 genotype, and the s1m1/s1m2 combination was found in 36% of them. H. pylori vacAs1m1 and s1m2 were also found in the saliva and biopsy of patients with gastric ulcer. The genotypes found in saliva and biopsy of the same patient had 51.1% agreement. In 27.6% of the 47 patients saliva^positive/biopsy^positive two genotypes were found in saliva, and one or both in the stomach.

Conclusions

The s1m1/s1m2 genotypes, alone or together, are found simultaneously in saliva and gastric biopsy of the same patient. These results suggest that H. pylori reaches the oral cavity by various ways, and that saliva can be the transmitting and re-infecting vector.     

Mouse model of gastric infection with cytotoxin-expressing strain of Helicobacter pylori in studying of pathogenesis of chronic gastric ulcer

Abstract Helicobacter pylori is a major risk factor for peptic ulcer, but studies on the role of H. pylori infection in gastric pathology are limited due to lack of convenient models resembling H. pylori infection in humans. We studied the effects of inoculation of conventional BALB/c mice with a toxigenic (cytotoxin associated gene A (cagA)+ and vacuolating cytotoxin gene A (vacA+) H. pylori strain on the course of healing of gastric ulcers. Following inoculation of toxigenic H. pylori or vehicle, gastric ulcers were produced in mice, which were then killed either at day 0 or after 2, 4, 7, 14 or 28 days and ulcer area and gastric blood flow (GBF) were determined. Gastric secretions from mice with chronic gastric fistulae were studied before and after inoculation with toxigenic H. pylori or vehicle (saline). The area (7 mm²) of ulcers in control mice decreased gradually and disappeared almost completely after 14 or 28 days. The ulcers in H. pylori-infected mice were present at all test days, showing a larger area than in vehicle control animals. The GBF in control mice rose gradually with decreasing ulcer size, being significantly higher at the ulcer margin than the ulcer crater. In contrast, the GBF in H. pylori-infected mice was significantly lower at the ulcer area than that in the vehicle controls but, again, the GBF at the ulcer margin was always higher than at the ulcer crater. Gastric acid output was reduced by more than 50% immediately after H. pylori inoculation and was accompanied by a significant increase in plasma gastrin release and a fall in gastric luminal somatostatin content. These secretory changes persisted at all test days. Oedema/congestion of surface epithelium appeared after 7 days and mucosal inflammatory infiltration appeared after 14 days, to further increase after 28 days, upon the induction of ulcer. Plasma interleukin (IL)-Iß and IL-12 were significantly elevated above the initial values compared with controls. Conventional mice with gastric ulcers can be successfully infected with an H. pylori strain expressing cagA and vacA cytotoxin and this infection markedly delays healing of the ulcers, probably due to the fall in GBF in the ulcer area, mucosal inflammation, cytokine release and impairment of the gastrin-somatostatin link.     

Different risk factors influence peptic ulcer disease development in a Brazilian population

AIM: To investigate age, sex, histopathology and Helicobacter pylori (H. pylori) status, as risk factors for gastroduodenal disease outcome in Brazilian dyspeptic patients.tients submitted to upper gastroscopy at Hospital das Clinicas of Marilia, antral biopsy specimens were obtained and subjected to histopathology and H. pylori diagnosis. All patients presenting chronic gastritis (CG) and peptic ulcer (PU) disease localized in the stomach, gastric ulcer (GU) and/or duodenal ulcer (DU) were included in the study. Gastric biopsies (n = 668) positive for H. pylori by rapid urease test were investigated for vacuolating cytotoxin A (vacA ) medium (m) region mosaicism by polymerase chain reaction. Logistic regression analysis was performed to verify the association of age, sex, histopathologic alterations, H. pylori diagnosis and vacA m region mosaicism with the incidence of DU, GU and CG in patients. RESULTS: Of 1466 patients submitted to endoscopy, 1060 (72.3%) presented CG [male/female = 506/554; mean age (year) ± SD = 51.2 ± 17.81], 88 (6.0%) presented DU [male/female = 54/34; mean age (year) ± SD = 51.4 ± 17.14], and 75 (5.1%) presented GU [male/female = 54/21; mean age (year) ± SD = 51.3 ± 17.12] and were included in the comparative analysis. Sex and age showed no detectable effect on CG incidence (overall c 2 = 2.1, P = 0.3423). Sex [Odds ratios (OR) = 1.8631, P = 0.0058] but not age (OR = 0.9929, P = 0.2699) was associated with DU and both parameters had a highly significant effect on GU (overall c 2 = 30.5, P 0.0001). The histopathological results showed a significant contribution of ageing for both atrophy (OR = 1.0297, P 0.0001) and intestinal metaplasia (OR = 1.0520, P 0.0001). Presence of H. pylori was significantly associated with decreasing age (OR = 0.9827, P 0.0001) and with the incidence of DU (OR = 3.6077, P 0.0001). The prevalence of m1 in DU was statistically significant (OR = 2.3563, P = 0.0018) but not in CG (OR = 2.678, P = 0.0863) and GU (OR = 1.520, P = 0.2863). CONCLUSION: In our population, male gender was a risk factor for PU; ageing for GU, atrophy and metapla-sia; and H. pylori of vacA m1 genotype for DU.