Persisting chronic gastritis and elevated Helicobacter pylori antibodies after successful eradication therapy

AIM: The persistence of chronic inflammation in gastric mucosa and elevated Helicobacter pylori antibodies after successful eradication therapy are common findings in clinical practice. We studied their possible association with each other and disappearance in long-term follow up, as well as their possible connection with gastric atrophy. PATIENTS AND METHODS: The study population consisted of 108 dyspeptic patients with successful eradication therapy median 6.4 years earlier. The patients underwent gastroscopy, and biopsies from antrum and corpus were evaluated by an experienced pathologist. Serum samples collected from 77 patients were studied for H. pylori antibodies, parietal cell antibodies, as well as for pepsinogen I, pepsinogen II, and gastrin-17 levels. RESULTS: The prevalence of chronic gastric inflammation and elevated H. pylori antibodies after successful eradication therapy decreased by time, but still after 5 years, 17 of 51 (33%) subjects had elevated H. pylori antibodies and 14 of 68 (21%) had a mild inactive chronic inflammation in gastric mucosa. In patients with and without chronic inflammation in gastric mucosa, elevated H. pylori antibodies were detected in three of 10 (30%) and 14 of 41 (34%), elevated parietal cell antibodies in one of 10 (10%) and six of 41 (15%), low pepsinogen I in one of 10 (10%) and none of 41, and elevated gastrin-17 in three of 10 (30%) and six of 41 (15%), respectively. CONCLUSION: More than 5 years after successful H. pylori eradication therapy, mild persistent chronic inflammation may occur in gastric mucosa in up to one-fifth and elevated H. pylori antibodies even in one-third of patients, although these two are independent phenomena.     

Predictive factors for improvement of atrophic gastritis and intestinal metaplasia after Helicobacter pylori eradication: a three-year follow-up study in Korea

Background and Aims: To date, data on the effects of anti‐Helicobacter therapy on the improvement of atrophic gastritis (AG) and intestinal metaplasia (IM) have been conflicting. This study was performed to investigate whether eradication of H. pylori could lead to the improvement of AG and IM, and the prognostic factors associated with the improvement of AG and IM. Methods: Four hundred patients consisting of H. pylori‐negative (n = 116) and H. pylori‐positive (n = 284) groups were followed up 1 and 3 years after initial H. pylori tests. Serum levels of pepsinogen (PG), bacteria, environmental factors, and genetic polymorphisms were determined. Results: The grade of corpus atrophy decreased at 1 and 3 years after successful eradication (p < .001 and p = .033, respectively). However, there was no significant change in the IM in the antrum and in the corpus. Prediction factors for the improvement of corpus AG by H. pylori eradication were baseline low PG I/II ratio (≤3), high salt intake, and corpus‐predominant gastritis. IM improvement was also associated with spicy food intake and high baseline grade of IM, in addition to these factors. In addition, IL‐1B‐511 C/T and IL‐6‐572 C/G alleles were found to inhibit IM improvement. However, H. pylori‐negative and noneradicated group did not show any significant change in AG or IM. Conclusion: Corpus AG was reversed by H. pylori eradication, and improvement of IM by H. pylori eradiation was more definite in patients with severe IM, low PG I/II ratio, and corpus‐predominant gastritis, suggesting that H. pylori eradication is valuable even in severe cases.     

Gastric acidity in patients with follicular gastritis is significantly reduced, but can be normalized after eradication for Helicobacter pylori

BACKGROUND: Follicular gastritis is thought to be caused by Helicobacter pylori infection. However, the pathophysiology of it remains unclear. MATERIALS AND METHODS: We assessed gastric acidity in 15 patients with follicular gastritis, aged 20-37 years, using a 24-hour intragastric pH-metry, as well as by histologic and serologic evaluations; and compared it with that in other age-matched groups: 18 cases of H. pylori-positive antrum-predominant gastritis, 12 of pangastritis, and 24 H. pylori-negative normals. In eight cases with follicular gastritis, it was re-assessed 6 months after the eradication therapy for H. pylori. RESULTS: During nighttime, the percentage of time with intragastric pH above 3.0 in follicular gastritis was significantly higher than that in normals (p<.0001), and in antrum-predominant gastritis (p<.001), but was comparable with that in pangastritis. In the daytime period, this parameter in follicular gastritis was significantly higher than that in normal (p<.001), in antrum-predominant gastritis (p<.001), and in pangastritis (p<.05). Marked mononuclear cell and neutrophil infiltration but no apparent glandular atrophy were observed in both the antrum and corpus. Serum pepsinogen I/II ratio was significantly lower in follicular gastritis than that in normals (p<.0001) and in antrum-predominant gastritis (p<.001), whereas serum gastrin was significantly higher than that in normals (p<.0001), in antrum-predominant gastritis (p<.01) and in pangastritis (p<.05). After eradication for H. pylori, all of the parameters in follicular gastritis were altered to the same ranges as those in normals. CONCLUSIONS: In follicular gastritis, gastric acidity is significantly reduced, but can be normalized by eradication of H. pylori. It can thus be speculated that inflammatory cytokines or H. pylori-infection-induced prostaglandins might strongly inhibit gastric acid secretion in follicular gastritis.     

Oxidative damage of the gastric mucosa in Helicobacter pylori positive chronic atrophic and nonatrophic gastritis, before and after eradication

Background. Helicobacter pylori is the main cause of gastritis and a primary carcinogen. The aim of this study was to assess oxidative damage in mucosal compartments of gastric mucosa in H. pylori positive and negative atrophic and nonatrophic gastritis. Materials and methods. Five groups of 10 patients each were identified according to H. pylori positive or negative chronic atrophic (Hp‐CAG and CAG, respectively) and nonatrophic gastritis (Hp‐CG and CG, respectively), and H. pylori negative normal mucosa (controls). Oxidative damage was evaluated by nitrotyrosine immunohistochemistry in the whole mucosa and in each compartment at baseline and at 2 and 12 months after eradication. Types of intestinal metaplasia were classified by histochemistry. Results. Total nitrotyrosine levels appeared significantly higher in H. pylori positive than in negative patients, and in Hp‐CAG than in Hp‐CG (p < .001); no differences were found between H. pylori negative gastritis and normal mucosa. Nitrotyrosine were found in foveolae and intestinal metaplasia only in Hp‐CAG. At 12 months after H. pylori eradication, total nitrotyrosine levels showed a trend toward a decrease in Hp‐CG and decreased significantly in Hp‐CAG (p = .002), disappearing from the foveolae (p = .002), but remaining unchanged in intestinal metaplasia. Type I and II of intestinal metaplasia were present with the same prevalence in Hp‐CAG and CAG, and did not change after H. pylori eradication. Conclusions. Oxidative damage of the gastric mucosa increases from Hp‐CG to Hp‐CAG, involving the foveolae and intestinal metaplasia. H. pylori eradication induces a complete healing of foveolae but not of intestinal metaplasia, reducing the overall oxidative damage in the mucosa.     

Geographic pathology of Helicobacter pylori gastritis

BACKGROUND AND AIM: Helicobacter pylori is etiologically associated with gastritis and gastric cancer. There are significant geographical differences between the clinical manifestation of H. pylori infections. The aim of this study was to compare gastric mucosal histology in relation to age among H. pylori-infected patients from different geographical areas using the same grading system. The prevalence of atrophy and intestinal metaplasia were also compared with the respective gastric cancer incidence in the different countries. METHODS: A total of 1906 patients infected with H. pylori from seven countries were evaluated. Entry criteria included H. pylori positive cases with antral and corpus biopsies between the ages of 18 and 75 years. The minimum number of cases required from a country was 100. Hematoxylin-eosin stained biopsies from antrum and corpus were scored semiquantitatively using the parameters suggested by the Sydney Classification System. Statistical evaluation was performed using Kruskal-Wallis test and Spearman's rank correlation test. RESULTS: The severity of gastric atrophy varied among the different groups with the highest scores being present in Japan. The lowest scores were found in four European countries and in Thailand. The scores for intestinal metaplasia were low in general except for Xi-an, Japan, and Shanghai. For all the countries, the presence of atrophy in the antrum correlated well (r = 0.891) with the incidence of gastric cancer. CONCLUSION: Using a standardized grading system in a large study of H. pylori-related geographic pathology, we found major differences in the overall prevalence and severity of H. pylori gastritis in relation to age. These differences mirrored the respective incidences of gastric cancer in those geographical areas.     

牙斑幽门螺杆菌与慢性胃炎之间的关系

目的研究牙斑幽门螺杆菌与慢性胃炎之间的关系。方法对胃炎组、胃炎治疗组分别进行牙斑和胃黏膜幽门螺杆菌培养和比较。结果牙斑细菌培养：胃炎组阳性14例,阳性率为12．8％;治疗组阳性11例,阳性率为10．1％。胃黏膜细菌培养：胃炎组阳性47例,阳性率为43．1％;治疗组阳性19例,阳性率为17．4％。治疗前后比较牙斑标本差异无显著性（P〉0．05）,胃黏膜标本差异有非常显著性（P〈0．001）。结论牙斑中确实存在着幽门螺杆菌,而且是胃内反复感染的源泉,以致慢性胃病反复发作,难以治愈。     

Immune response to CagA protein is associated with improved platelet count after Helicobacter pylori eradication in patients with idiopathic thrombocytopenic purpura

BACKGROUND: Improvement in platelet counts has been reported after eradication of Helicobacter pylori in patients with idiopathic thrombocytopenic purpura (ITP). We examined the levels of serum markers of gastritis and anti-CagA (cytotoxin-associated gene A) IgG antibody in patients with ITP to investigate whether these factors are associated with the platelet response after H. pylori eradication therapy. MATERIALS AND METHODS: One hundred and sixteen consecutive patients with ITP were assessed for H. pylori infection by (13)C-urea breath test and serum H. pylori antibody test. Patients with H. pylori infection received eradication therapy. Before and after eradication therapy, we evaluated serum levels of gastrin, pepsinogen (PG)-I, and PG-II and the anti-CagA IgG antibody titer. RESULTS: H. pylori infection was found in 67 (58%) of the 116 patients with ITP. Fifty-two infected patients received eradication therapy, which was successful in 44 patients (85%). Twenty-seven patients (62%) showed an increased platelet count and were identified as responders. The duration of ITP was shorter in responders than in nonresponders (p = .017). There was no difference of the levels of gastrin and PGs between responders and nonresponders. Before eradication therapy, the serum anti-CagA antibody titer did not differ significantly between responders and nonresponders. However, reduction in the anti-CagA antibody titer after eradication therapy was significantly greater in responders than in nonresponders (p = .013). CONCLUSIONS: H. pylori eradication therapy improves the platelet count in H. pylori-positive patients with ITP of short duration. Immune response of hosts to CagA protein of H. pylori may play a role in the pathogenesis of ITP.     

Previous Helicobacter pylori infection–induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false‐negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection–induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton‐pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%‐0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%‐0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection–induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high‐risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high‐risk subgroup of this understudied population is especially important.     

229例慢性胃炎患者幽门螺杆菌培养及耐药情况

目的了解慢性胃炎患者H.pylori感染及其耐药情况,为临床治疗提供参考。方法慢性胃炎患者胃镜活检标本培养分离H.pylori,对分离的H.pylori采用纸片扩散法进行耐药性检测。结果229例患者分离出97株H.pylori;H.pylori分离阳性率为42．36％（97／229）,其中男性分离率为43．79％（67／153）,女性分离率为39．47（30／76）;92株H.pylori对抗生素的耐药性分别为：甲硝唑8．7％,克拉霉素7．6％,阿莫西林1．1％、呋喃唑酮1．1％,阿奇霉素4．4％,左氧氟沙星0％。结论慢性胃炎患者H.pylori感染率较高,但与性别、年龄无关;慢性胃炎H.pylori对常用抗生素敏感,建议采用左氧氟沙星、阿莫西林、呋喃唑酮进行治疗。     

Monoclonal gammopathy of undetermined significance and Russell body formation in Helicobacter pylori gastritis

BACKGROUND: Infection by Helicobacter pylori has been linked to monoclonal gammopathy of undetermined significance (MGUS). MGUS is thought to develop due to chronic antigenic stimulation in people with a specific genetic predisposition. METHODS AND RESULTS: We describe a patient presenting with dyspepsia associated with H. pylori-related erosive gastritis. Histopathologic findings revealed infiltration with plasma cells containing accumulated condensed intercisternal immunoglobulins, the so-called 'Russell bodies'. In addition, MGUS was present with total immunoglobulins within the normal range but a significantly decreased serum concentration of IgG subtype 3. Molecular analyses demonstrated IgH formation, T-cell receptor gamma rearrangement, and alterations within the IgHG3 gene sequence. Following H. pylori eradication, gastritis and dyspepsia gradually resolved but MGUS persisted for at least 22 months. CONCLUSIONS: This is the first report to demonstrate that upon infection with H. pylori, an impaired secretory capacity of plasma cells due to specific molecular changes can present as Russell body gastritis. The molecular findings question a pathogenetic link between Russell bodies and H. pylori, but suggest genetic alterations in the immunoglobulin locus as the possible cause for both MGUS and Russell body gastritis.     

Inducible nitric oxide synthase expression before and after eradication of Helicobacter pylori in different forms of gastritis

An increased expression of inducible nitric oxide synthase (iNOS) has been observed in the inflamed human gastric mucosa as well as in some tumors. This observation suggests a pathobiological role of elevated NO production. The purpose of this study was to compare the immunohistochemical iNOS expression in the different kinds of gastritis before and after the eradication of Helicobacter pylori. We performed iNOS and H. pylori immunohistochemical staining and counted iNOS positive cells. We detected elevated expression of iNOS around sites infected with H. pylori. iNOS expression in chemical gastritis was strongly elevated in mucosal glands. After treatment, we found a significant difference in iNOS expression in patients with classical H. pylori-induced antrum predominant gastritis and in patients with active autoimmune gastritis. In the special case of progressed gastritis with intestinal metaplasia we found persistence of intestinal metaplasia, and we could not find a significant difference in the number of positive iNOS cells before and after treatment. The persistence of IM as a possibly precancerous lesion is probably at least in the antrum a source of continuous iNOS induction even after H. pylori eradication.     

Atrophic gastritis, Helicobacter pylori, and colorectal cancer risk: a case-control study

BACKGROUND: Helicobacter pylori is a major risk factor for atrophic gastritis and gastric cancer. Various extragastric manifestations of H. pylori infection have also recently been suggested. However, the correlation between H. pylori and colorectal cancer (CRC) is controversial. The aim of this study was to examine the correlation between H. pylori, serum gastrin level, and atrophic gastritis with CRC. MATERIALS AND METHODS: Subjects were patients with CRC; controls were participants of a health check-up program that was conducted between October 1998 and March 2002 at four hospitals in Nagano Prefecture. For 121 newly diagnosed CRC cases, two controls matched by age (within 3 years), gender, and residence were randomly selected from the program participants. We conducted questionnaires and obtained blood samples from the cases and their controls. Consequently, the CRC cancer pairs consisted of 113 cases and 226 controls. RESULTS: Neither H. pylori infection nor gastrin level nor atrophic gastritis showed any association with a risk for CRC. However, serologically determined atrophic gastritis demonstrated significant elevation in odds ratios (ORs) for rectal cancer (OR = 3.15, 95% confidence interval; 1.19-8.35). CONCLUSIONS: Gastric conditions such as chronic H. pylori infection and atrophic gastritis are unlikely to increase the risk for CRC, although atrophic gastritis may increase the risk of rectal cancer.     

抗坏血酸对幽门螺杆菌相关萎缩性胃炎小鼠的干预

目的研究不同浓度抗坏血酸(ascorbic acid)溶液对幽门螺杆菌(Helicobacter pylori,H.pylori)相关萎缩性胃炎小鼠模型的作用。方法将C57BL/6小鼠随机分为5组,每组10只。组1为空白对照组,余4组小鼠用幽门螺杆菌悉尼菌株(Helicobacter pylori-Sydney strain 1,H.pylori-SS1)感染2周,快速尿素酶法和免疫组织化学法检测H.pylori-SS1的定植;组3、组4和组5小鼠分别给予抗坏血酸低倍剂量(0.1 g/L)、中倍剂量(0.5 g/L)和高倍剂量(1.0 g/L)灌胃22周。灌胃结束后,处死所有小鼠取胃组织和血清,H&E染色观察组织学变化,ELISA检测血清胃泌素(gastrin)和白介素8(IL-8)水平。结果与H.pylori组相比,抗坏血酸干预组胃组织萎缩程度减轻、血清胃泌素水平升高、炎症因子水平降低(组2 vs组3:F=21.730,P=0.029;组2 vs组3:F=42.781,P=0.015;组2 vs组3:F=35.720,P=0.021),中倍剂量组较低倍剂量组有更显著的作用(组3 vs组4:F=21.730,P=0.041;组3 vs组4:F=42.781,P=0.034;组3 vs组4:F=35.720,P=0.043),但高倍剂量组与中倍剂量组差异无统计学意义(组4 vs组5:F=21.730,P=0.125;组4 vs组5:F=42.781,P=0.391;组4 vs组5:F=35.720,P=0.450)。结论抗坏血酸干预可减轻小鼠H.pylori相关萎缩性胃炎症状,高剂量抗坏血酸与中低剂量比无显著差异。     

Apoptosis in Helicobacter pylori gastritis is related to cagA status

BACKGROUND: Helicobacter pylori infection increases gastric epithelial cell apoptosis; however, the influence of cagA status is still controversial. We aimed to investigate if cagA status is related to apoptosis in H. pylori gastritis at different anatomic sites of the gastric mucosa. MATERIALS AND METHODS: We studied by immunohistochemistry (streptavidin-biotin method) pro-apoptotic (Bax and Bak) and antiapoptotic (Bcl-2 and Bcl-x) proteins expression, scored from 0 to 4, in gastric biopsies, at the antrum (lesser and greater curvatures), incisura, and corpus (greater curvature) from 50 patients with H. pylori gastritis (22 males, 28 females, median age 40 years) and eight non-infected patients (6 males, median age 39.6 years). H. pylori and cagA status were determined by polymerase chain reaction. RESULTS: Apoptotic proteins were expressed in a granular pattern, in the cytoplasm of foveolar cells; Bax and Bak expression was higher than Bcl-2 and Bcl-x in most cases and was significantly higher in patients infected by cagA-positive strains than in those infected by cagA-negative strains (p = .001). Bak expression was higher at the lesser curvature (antrum and incisura) than in the other regions (p = .002) and was correlated with atrophy. Anti-apoptotic proteins were significantly more expressed at the antral lesser curvature than in the other regions of the stomach (Bcl-2: p = .02; Bcl-x: p < .001). CONCLUSIONS: Infection with cagA-positive strains is significantly associated with overexpression of pro-apoptotic proteins in the gastric mucosa, mainly at the antral lesser curvature, which may have a role on atrophy development. Anti-apoptotic proteins were also overexpressed at the lesser curvature, which may occur to keep epithelial cell turnover or might be related to malignant transformation.     

A coordinated cytotoxic effect of IFN-gamma and cross-reactive antibodies in the pathogenesis of Helicobacter pylori gastritis

Background. Helicobacter pylori (H. pylori) infection is associated with chronic infiltration into the stomach by T cells and plasma cells producing IFN‐γ and antibodies of various specificities, respectively. It is unknown whether these lymphocyte‐products may play coordinated roles in the gastric pathology of this infection. Aims. To know how IFN‐γ may relate to anti‐H. pylori antibodies in their roles in pathogenesis, we determined the isotype subclass of those antibodies as well as their cross‐reactivity and cytotoxicity to gastric epithelium. Methods and Results. We infected BALB/c mice with H. pylori (SS1, Sydney Strain 1) and generated monoclonal antibodies, which were comprised of 240 independent clones secreting immunoglobulin and included 80 clones reactive to SS1. Ninety percent of the SS1‐reactive clones had IgG2a isotype. Two clones, 2B10 and 1A9, were cross reactive to cell surface antigens in H. pylori and to antigens of 28 KDa and 42 KDa, respectively, which were present on the cell surface of and shared by both mouse and human gastric epithelial cells. The antigens recognized by these monoclonal antibodies localized a distinctive area in the gastric glands. In the presence of complement, 2B10 showed cytotoxicity to gastric epithelial cells. The effect was dose dependant and augmented by IFN‐γ. Finally, administration of 2B10 to mice with SS1 infection aggravated gastritis by increasing cellular infiltration. Conclusion. IFN‐γ by gastric T cells may participate in pathogenesis of the H. pylori infected stomach by directing an isotype‐switch of anti‐H. pylori antibodies to complement‐binding subclass and by augmenting cytotoxic activity of a certain autoantibody. This may explain a host‐dependent diversity in gastric pathology of the patients with H. pylori infection.     

CagA and VacA are immunoblot markers of past Helicobacter pylori infection in atrophic body gastritis

BACKGROUND AND AIM: Atrophic body gastritis (ABG) may be induced by H. pylori infection. It is difficult to diagnose H. pylori infection in this condition, since during progression of body atrophy the bacterium disappears. In 30% of patients with ABG no sign of H. pylori infection is detectable. We aimed to investigate whether patients with ABG, classified as H. pylori-negative by conventional methods (ELISA serology and Giemsa stain histology), have been previously exposed to the infection. METHODS: Case series consisted of 138 outpatients with ABG, of whom 31 are H. pylori negative (histology and ELISA serology), and 107 are H. pylori related (histology and ELISA serology positive: active infection, n = 29; only serology positive: past infection, n = 78). Thirty control subjects who were H. pylori negative at histology and ELISA serology were investigated. Immunoblotting of sera against H. pylori whole-cell protein lysate was performed. RESULTS: None of the control sera recognized CagA, VacA, heat-shock protein B, and urease B, yielding a specificity of 100%. All H. pylori-negative patients with ABG showed immunoblotting seroreactivity, including in each case either CagA or VacA. The concomitant seroreactivity against CagA and VacA was highly prevalent in the H. pylori-negative patients with ABG, comparable to those with active infection (77.4% vs. 86.2%) and with past infection (vs. 61.5%). CONCLUSIONS: Immunoblotting against CagA and VacA is able to prove past exposure to H. pylori infection in all patients with ABG defined as H. pylori-negative by conventional methods, suggesting a hidden role of H. pylori infection in gastric atrophy also in these patients.     

Polaprezinc attenuates Helicobacter pylori-associated gastritis in Mongolian gerbils

Background. The ammonia‐monochloramine system plays an important role in Helicobacter pylori‐associated gastric mucosal injury. Polaprezinc, a new antiulcer agent, has a scavenging action against monochloramine. The aim of the experiment was to investigate the inhibitory effects of polaprezinc on the H. pylori‐induced gastritis in Mongolian gerbils. Materials and Methods. Mongolian gerbils fasting for 24 hours were orally given culture broth containing 2–4 × 10⁸ colony‐forming units of H. pylori ATCC 43054 per milliliter. From 4 hours after inoculation until the end of the experiment, gerbils were given chow pellets with or without 0.02% polaprezinc. All gerbils were killed 12 weeks later. The grades of H. pylori density and histologic features of gastritis were evaluated in accordance with the Updated Sydney System. The scavenging effect of polaprezinc on monochloramine was investigated spectrophotometrically. Results. Polaprezinc had little or no influence on the H. pylori density in both pyloric and fundic mucosae. However, it significantly attenuated the development of polymorphonuclear neutrophil activity, mononuclear infiltration, and surface epithelial erosion in both pyloric and fundic mucosae compared with those of the control group. H. pylori inoculation significantly increased the heights of both pyloric and fundic mucosae (mainly due to the increased height of foveolar hyperplasia), but polaprezinc inhibited the increase of mucosal thickness in both pyloric and fundic mucasae. No intestinal metaplasia was detected in this study. Spectrophotometric examination revealed that polaprezinc scavenged monochloramine. Conclusions. Polaprezinc inhibited the development of H. pylori‐induced gastritis through its scavenging action against monochloramine.     

益生菌在幽门螺杆菌根除治疗中的应用

幽门螺杆菌(Helicobacter pylori,H.pylori)是导致活动性胃炎、消化性溃疡、胃癌、胃黏膜相关淋巴组织淋巴瘤等消化系统疾病的重要病因之一,已被世界卫生组织确认为Ⅰ类致癌因子,根除H.pylori对防治上述疾病有重要意义。目前临床上主要采用含抗生素的三联或四联药物进行H.pylori的根除,虽然取得一定的疗效,但随着抗生素耐药率逐年增加,根除率持续下降,限制了其广泛应用。此外,初次或多次治疗失败后再治疗可选择的药物很少。近年来人们开始尝试将益生菌应用在H.pylori根除治疗中,并取得一定疗效。本文就益生菌在辅助根除幽门螺杆菌方面的研究进展作一简单综述。     

Diversity of Helicobacter pylori cagA and vacA genes in Costa Rica: its relationship with atrophic gastritis and gastric cancer

BACKGROUND: Associations between Helicobacter pylori gene diversity and gastric cancer have not been reported on in Costa Rica, despite its being one of the countries with the highest gastric cancer incidence and mortality rates in the world. The aim of this study was to determine the prevalence of H. pylori cagA and vacA genes and investigate whether it could be correlated with atrophic gastritis (AG) and gastric cancer (GC) in Costa Rica. MATERIALS AND METHODS: Genomic DNAs from isolates of 104 patients classified into two groups: non-atrophic gastritis group (n = 68) and atrophic gastritis group (n = 36), were subjected to PCR-based genotyping of cagA and vacA genes and their correlation with clinical outcome was investigated. Total DNA extractions from gastric tissues of 25 H. pylori-infected gastric cancer patients were utilized for comparative purposes. RESULTS: The presence of cagA (75.3%), vacA s1b (75.3%), and vacA m1 (74.2%) was detected, and colonization by strains with different vacA genotypes in the same stomach was found in 9.7% of the patients. Age- and sex-adjusted vacA s1b and vacA m1 were associated with GC while only vacA m1 was significantly associated with AG. A tendency for association between cagA and vacA s1b, and AG was reported. CONCLUSIONS: The prevalence status of the cagA and vacA (s1/m1) genes in Costa Rica seems to fall between that found in European/North American and East Asian countries, and both cagA and vacA seem to have clinical relevance in this country.