幽门螺杆菌感染与胃不同部位组织学病变的关系

目的 明确幽门螺杆菌(Helicobacter pylori,H,pylori)感染与胃不同部位粘膜组织学病变的关系。方法 在215例胃镜受检者胃窦、角、体三点取材进行组织学检查，Giemsa染色明确H.pylori感染情况，HE染色计量观察组织学病变情况，分析两者的相关关系。结果 从胃窦到胃角、胃体，炎症程度(单个核细胞浸润)、活动度(中性粒细胞浸润)、糜烂及淋巴滤泡形成均递减，H.pylori阳性者积分高于阴性者。在胃窦和胃角部，H.pylori感染更常引起近腔面上皮分泌下降，而在胃体部无此发现，H.pylori感染在三个部位均可引起腺体萎缩。结论 H.pylori感染是胃多部位组织学病变如淋巴细胞、中性粒细胞浸润、糜烂和淋巴滤泡形成与粘膜萎缩的病因，在胃窦和胃角引起的病变重于胃体。     

Enhanced somatostatin secretion into the gastric juice with recovery of basal acid output after Helicobacter pylori eradication in gastric ulcers

BACKGROUND AND AIM: Antral somatostatin interacts with gastric acid secretion. We aimed to investigate the effect of eradication on gastric acid, somatostatin secretion and mucosal histology in gastric ulcer patients with Helicobacter pylori (H. pylori) infection. METHODS: Twenty-eight patients (21 male, 7 female) with H. pylori-positive gastric ulcer were treated with dual therapy. Before and 4-8 weeks after the therapy, the histology of biopsy specimens, basal acid output (BAO) and maximal acid output (MAO) after stimulation with tetragastrin were assessed. Somatostatin concentration in the gastric juice was measured by radioimmunoassay, and somatostatin output during either the basal or gastrin-stimulated period was also examined. RESULTS: Eradication was successful in 22 patients. Before treatment, the acid and somatostatin output were inversely related to the severity of neutrophil infiltration in the corpus and antrum, respectively. After successful eradication, improvement of histological inflammation and an increase in BAO, basal and gastrin-stimulated somatostatin output were observed. Eradication had no effect on atrophy and MAO. There was a positive correlation between gastric acid and somatostatin output in the basal or stimulated condition, irrespective of H. pylori infection. CONCLUSIONS: The present results suggest that recovery of gastric BAO may be caused by an improvement in corpus neutrophil infiltration, but not by an increase in parietal cell volume or a change in atrophy. Also, there was an increase in basal and gastrin-stimulated somatostatin-containing cell activity accompanied by improved antral neutrophil infiltration in the early phase after H. pylori eradication in gastric ulcers.     

No relationship between IL-1B gene polymorphism and gastric acid secretion in younger healthy volunteers

AIM: To investigate the influence of IL-1B-511 gene polymorphism on IL-1B mRNA expression and gastric acid output in individual with or without Helicobacter pylori (H pylori) infection. METHODS: IL-1B mRNA expression and gastric acid secretion in 117 health volunteers were assayed using semi-quantitative RT-PCR and gastric juice assay, respectively. Pepsinogen (PG) Ⅰ and Ⅱ of 255 subjects (including 117 health volunteers) were also examined. RESULTS: T/T genotype individuals with H pylori infection had a more decreased PG Ⅰ/Ⅱ ratio. In gastric antrum mucosa, the individuals with H pylori infection had higher IL-1B expression than those without H pylori infection, but there was no obvious difference among each genotype. In gastric corpus, the individuals with H pylori infection had a significantly higher IL-1B expression than those without H pylori infection. IL-1B-511T/T genotype was markedly higher as compared with the other two genotypes. Both maximal acid output and basic acid output were similar among each genotype in IL-1B-511 gene locus, regardless of H pylori infection. CONCLUSION: IL-1B-511 T allele does not decrease gastric acid output, although it has a stimulated influence on IL-1B expression. Consequently, the pathway, through which IL-1B plays a central role in gastric cancer development, might not depend on low acid, but on the other regulation mechanisms.     

Helicobacter pylori infection upregulates endothelial nitric oxide synthase expression and induces angiogenesis in gastric mucosa of dyspeptic patients

BACKGROUND: Helicobacter pylori (H. pylori) infection induces nitric acid (NO) overproduction through inducible NO synthase (NOS) expression, subsequent DNA damage and enhanced antiapoptosis signal transduction sequence in the human gastric mucosa, whereas its possible effect on endothelial nitric oxide synthase (eNOS) expression has not as yet been investigated. The aim of this study was to evaluate the effect of H. pylori infection in the expression of eNOS in gastric mucosa. PATIENTS AND METHODS: We prospectively studied 30 nonsmoking dyspeptic patients (12 men, 18 women, mean age 54.26+/-12.89 years). The diagnosis of H. pylori infection was based mainly on histology. The histological grading of H. pylori infection was evaluated according to the modified Sydney classification. Histological grading of eNOS expression and microvessel density as estimated by CD34 expression were determined by immunohistochemistry (degree 0-3) and correlated with H. pylori infection and histological degree of gastritis. RESULTS: Twelve patients were H. pylori-positive and 18 patients were H. pylori-negative. The two groups were matched for age (P=0.139), sex (P=0.342) and similar degree of gastritis. Intensity of eNOS and CD34 expression in the corpus and antrum were significantly correlated (P<0.001). eNOS expression was correlated with H. pylori infection in the mucosa of the body and antrum (P=0.013 and 0.037, respectively) but not with gastric inflammation and activity (P=0.848 and 0.871, respectively, for the corpus and P=0.565 and 0.793, respectively, for the antrum). H. pylori-positive patients showed higher expression of CD34-positive blood vessels in the mucosa of the antrum (P=0.048). CD34 expression was correlated with gastric inflammation and activity (P=0.03 and 0.044, respectively) in the mucosa of the antrum of H. pylori-positive patients. CONCLUSION: H. pylori infection upregulates eNOS, and induces angiogenesis, contributing to H. pylori-associated pathophysiology in gastric mucosa.     

根除幽门螺杆菌对胃窦黏膜萎缩和肠上皮化生逆转影响的前瞻性研究

目的 探讨根除幽门螺杆菌(Hp)对逆转胃窦黏膜萎缩和肠上皮化生(肠化生)病理改变的作用.方法 对行胃镜检查的门诊患者,于胃窦处取黏膜活检行病理学检查,并确定Hp感染状态.将Hp感染的慢性胃炎伴胃窦黏膜萎缩或(和)肠化生患者作为入选对象并分为两组,一组行Hp根除治疗,为Hp根除组(48例);另一组未行抗Hp治疗,为对照组(38例).分别在1年和5年后对两组患者进行胃镜随访,并在同一部位取材,根据2次病理结果的不同分为逆转和未逆转两种情况.结果 胃窦黏膜萎缩逆转率在Hp根除组显著高于对照组(37.1%比12.0%).5年后Hp根除组的胃窦黏膜萎缩逆转率显著高于1年后,45岁以下者显著高于45岁以上者.而在对照组中,胃窦黏膜萎缩逆转和随访的时间及年龄无明显关系.在2次随访中,肠化生逆转率在Hp根除组和对照组间差异均无统计学意义(P>0.05).结论 根除Hp尚不能逆转胃窦黏膜肠化生,但对逆转胃窦黏膜萎缩有作用,这种作用与随访观察时间及患者的年龄有关.因此,对有Hp感染的胃窦黏膜萎缩者应及早行根除Hp治疗.     

Helicobacter pylori gastritis and gastric physiology

It is now recognized that Helicobacter pylori infection exerts profound and diverse effects on gastric acid secretory function and that the alterations in acid secretion depend on the pattern of gastritis caused by the infection. In patients with an antral predominant nonatrophic gastritis, there is acid hypersecretion leading to duodenal ulcer disease. In patients with an atrophic pangastritis, there is markedly reduced acid secretion and increased risk for gastric cancer. It is now recognized that acid secretion also modifies H. pylori gastritis and a person's premorbid acid secretory status may be an important factor in determining the pattern of gastritis that an individual develops. This two-way interaction between H. pylori gastritis and gastric acid secretion is important in understanding the role of H. pylori infection in the response to proton-pump inhibitor therapy: It explains the more profound control of gastric acid secretion in H. pylori-positive patients and why rebound acid hypersecretion is confined to H. pylori-negative subjects.     

Changes in gastric acid secretion assayed by endoscopic gastrin test before and after Helicobacter pylori eradication

BACKGROUND: It remains controversial whether or not Helicobacter pylori infection causes altered gastric acid secretion. A novel test for evaluating gastric acid secretion (endoscopic gastrin test; EGT) has recently been developed. AIM: To investigate by EGT the effects of H pylori eradication on the state of gastric acid secretion in patients with peptic ulcer. METHODS: Twenty six patients with duodenal ulcer and 33 with gastric ulcer, for all of whom H pylori infection had been documented, were studied by EGT, histological examination of gastric mucosa, and measurement of plasma gastrin levels before and one and seven months after H pylori eradication. RESULTS: In patients with duodenal ulcer, the mean EGT value before H pylori eradication was higher than that in H pylori negative controls, but it had decreased significantly seven months after the treatment. In contrast, the mean EGT value of patients with gastric ulcer before H pylori eradication was lower than that in H pylori negative controls, but it had increased one month after the treatment; this was followed by a slight decrease at seven months. In both groups, mean EGT values seven months after the treatment were not significantly different from the mean control value. CONCLUSIONS: The reduced acid secretion in gastric ulcer patients and gastric acid hypersecretion in duodenal ulcer patients were both normalised after the clearance of H pylori.     

Helicobacter pylori infection prevents erosive reflux oesophagitis by decreasing gastric acid secretion

BACKGROUND: Helicobacter pylori infection is less prevalent and atrophic gastritis is less extensive in patients with reflux oesophagitis than those without it, but few studies have examined this relationship directly. AIMS: We investigated the relationship between H pylori infection, acid secretion, and reflux oesophagitis in Japanese subjects. SUBJECTS: A total of 105 patients with erosive reflux oesophagitis were compared with 105 sex and age matched patients without reflux oesophagitis. METHODS: The diagnosis of H pylori infection was made by histological examination of gastric mucosal biopsy specimens, rapid urease test, and detection of serum IgG antibodies. Acid secretion was assessed by the endoscopic gastrin test. RESULTS: H pylori infection was present in 36 patients with erosive reflux oesophagitis (34.3%) and in 80 control subjects (76.2%) (odds ratio 0.163, 95% confidence interval 0.09-0.29). Overall acid secretion was significantly greater in patients with reflux oesophagitis. Among H pylori positive patients, acid secretion was greater in patients with reflux oesophagitis than those without oesophagitis. CONCLUSION: In Japan, erosive reflux oesophagitis occurs most often in the absence of H pylori infection and gastric hyposecretion. Even in the presence of H pylori infection, reflux oesophagitis is more likely to develop in patients without gastric hyposecretion. H pylori infection may inhibit reflux oesophagitis by inducing hypoacidity.     

Histological analysis of gastritis and Helicobacter pylori infection in patients with early gastric cancer: a case-control study

BACKGROUND AND AIMS: Infection with Helicobacter pylori is associated with an increased risk of gastric adenocarcinoma. However, most patients with H. pylori infection will not develop gastric cancer. The aims of the present study were to examine which histological features, including H. pylori infection, would increase the risk of gastric cancer using a case-control study. METHODS: Three gastric biopsy specimens were taken from 72 patients with early gastric cancer and 72 age- and sex-matched control subjects. The grade of gastritis was examined according to the updated Sydney System. The presence of H. pylori infection was determined by serology and histology. Odds ratio (OR) of developing gastric cancer was calculated for H. pylori positivity and histological features using conditional logistic regression. For patients with H. pylori infection, histological features in cancer patients and control subjects were compared. RESULTS: The OR of the presence of mononuclear cell infiltration in the corpus and intestinal metaplasia in the angulus were significantly elevated. The grade of mononuclear cell infiltration in the corpus and antrum was significantly higher in both types of cancer patients than controls. Glandular atrophy and intestinal metaplasia were increased in patients with intestinal-type cancer in the angulus and antrum. Bacterial density in the corpus and polymorphonuclear cell infiltration in the antrum were increased in patients with diffuse-type cancer. CONCLUSIONS: Severe chronic gastritis induced by H. pylori infection seems to be associated with diffuse-type gastric cancer. Glandular atrophy and intestinal metaplasia, which occur in gastric mucosa with chronic inflammation, are significantly associated with intestinal-type cancer.     

The role of gastrin in ulcer pathogenesis.

Duodenal ulcer patients are characterized by an antrum-predominant, body-sparing, nonatrophic Helicobacter pylori (H. pylori) gastritis, which results in increased gastrin release and increased acid secretion. The increased gastrin release is caused by the infection impairing the acid-mediated inhibitory control of gastrin release. The elevated levels of the gastrin stimulate the healthy uninflamed, non-atrophic acid-secreting region of the stomach to secrete excess amounts of acid. The increased gastrin also exerts trophic effects on the oxyntic mucosa, causing hyperplasia of both the enterochromaffin-like cells and the parietal cells. These trophic changes in the mucosa further enhance its ability to secrete acid. The increased acid secretion results in an increased duodenal acid load, causing gastric metaplasia of the duodenal bulb and eventually the development of ulceration. In H. pylori-infected subjects without duodenal ulceration, a different pattern of gastritis is seen. This includes atrophy of the antrum, which reduces the number of G-cells and thus the degree of hypergastrinaemia induced by the antral infection. There are usually also varying degrees of inflammation and atrophy of the acid-secreting mucosa, which impair its ability to secrete acid in response to gastrin stimulation. The combined effects of the atrophy of the antrum and the inflammation of the antrum of the body mucosa therefore prevent H. pylori-induced acid hypersecretion and may result in varying degrees of hypochlorhydria. The particular pattern of gastritis that a subject develops in response to H. pylori infection and their likelihood of developing a duodenal ulcer is likely to be determinded by host genetic factors plus dietary factors.     

H pylori infection causes chronic pancreatitis in Mongolian gerbils

AIM： To investigate whether chronic H pylori infection has the potential to induce pancreatitis in the Mongolian gerbil model, and whether it is dependent on an intact type Ⅳ secretion system. METHODS： Mongolian gerbils were infected with wild type （WT） H pylori type Ⅰ strain B128 or its isogenic mutant B128 △cag γ （defective type Ⅳ secretion）. After seven months of infection, H pylori was reisolated from antrum and corpus and Hpylori DNA was analyzed by seminested polymerase chain reaction （PCR）. Inflammation and histological changes were documented in the gastric antrum, corpus, and pancreas by immunohistochemistry. Cytokine mRNA, gastric pH, plasma gastrin, amylase, lipase, and glucose levels were determined.
RESULTS： The H pylori infection rate was 95%. Eight infected animals, but none of the uninfected group, developed transmural inflammation and chronic pancreatitis. Extensive interstitial fibrosis and inflammation of the pancreatic lobe adjacent to the antrum was confirmed by trichrome stain, and immuno-histochemically. Pro-inflammatory cytokine mRNA was significantly increased in the antral mucosa of all infected gerbils. In the corpus, only cytokine levels of WT-infected animals andthose developing transmural inflammation and pancreatitis were significantly increased. Levels of lipase, but not glucose or amylase levels, were significantly reduced in the pancreatitis group. H pylori DNA was detected in infected antral and corpus tissue,but not in the pancreas
CONCLUSION： H pylori infection is able to induce chronic pancreatitis in Mongolian gerbils independently of the type Ⅳ secretion system, probably by an indirect mechanism associated with a penetrating ulcer.     

Effect of Helicobacter pylori and its eradication on gastric juice ascorbic acid.

The presence of ascorbic acid in gastric juice may protect against gastric carcinoma and peptic ulceration. This study examined the effect of Helicobacter pylori (H pylori) on the secretion of ascorbic acid into gastric juice by measuring fasting plasma and gastric juice ascorbic acid concentrations in patients with and without the infection and also before and after its eradication. Gastric juice ascorbic acid concentrations in 19 H pylori positive patients were significantly lower (median 2.8, range 0-28.8 micrograms/ml) than those in 10 H pylori negative controls (median 17.8, range 5.6-155.4 micrograms/ml) (p < 0.0005) despite similar plasma ascorbic acid concentrations in both groups. The median gastric juice:plasma ascorbic acid ratio in the H pylori positive patients was only 1.16 (range 0.02-6.67), compared with a median ratio of 4.87 (range 0.76-21.33) in H pylori negative controls (p < 0.01). In the patients with H pylori infection there was a significant negative correlation between the severity of the antral polymorphonuclear infiltrate and gastric juice ascorbic acid concentrations (correlation coefficient -0.52, p = 0.02). After eradication of H pylori in 11 patients, gastric juice ascorbic acid concentrations rose from 2.4 (0-12.8 micrograms/ml) to 11.2 (0-50 micrograms/ml) (p = 0.01). The median gastric juice: plasma ascorbic acid ratio also increased from 1.33 (0.05-6.67) to 2.89 (0.01-166) (p = 0.01). In conclusion, the high gastric juice:plasma ascorbic acid ratio in H pylori negative subjects shows active secretion of ascorbic acid into gastric juice. Secondly, H pylori infection causes a reversible lowering of gastric juice ascorbic acid concentrations, which may predispose to gastric carcinoma and peptic ulceration.     

Higher gastric mucin secretion and lower gastric acid output in first-degree relatives of gastric cancer patients

BACKGROUND: Patients infected by Helicobacter pylori who have first-degree relatives with gastric cancer have an 8-fold increased risk of developing gastric cancer themselves. Mucins are high-molecular-weight glycoproteins that play a cardinal role in the protective mechanism of the gastric epithelium. AIM: To study gastric acid and mucin secretion in dyspeptic patients with and without a family history of gastric cancer and H. pylori infection. MATERIALS AND METHODS: Twenty-six dyspeptic patients underwent esophago-gastro-duodenoscopy, gastric biopsies, and acid and mucin secretory tests. The sample was divided by family history of gastric cancer and H. pylori status. RESULTS: Patients who were infected by H. pylori had a significantly higher degree of inflammation than those who were not. H. pylori-positive patients with a positive family history had a lower basal and maximal gastric acid output than infected patients with no family history and noninfected controls, and a higher basal and maximal mucin output than infected patients with no family history. MUC5AC was the major mucin species expressed in gastric juice. CONCLUSIONS: In patients with relatives with gastric cancer, H. pylori infection is associated with a more severe inflammatory reaction consisting of decreased gastric acid secretion and increased mucin secretion.     

广州胃病患者幽门螺杆菌多株感染的研究

目的了解我国Ｈｐ感染人群中的多株感染状况．方法取因上腹不适行内镜检查的２０例Ｈｐ阳性患者（胃溃疡６例,十二指肠溃疡８例,慢性胃炎６例）的胃窦和胃体粘膜组织,进行Ｈｐ培养．初代培养后,分别取胃窦和胃体各１０个菌落进行传代,抽提各菌落ＤＮＡ,应用聚合酶链反应随机引物扩增的ＤＮＡ多态指模技术［ＲＡＰＤＰＣＲ］进行菌株鉴定．结果ＰＣＲ扩增产物电泳分析显示有１８例患者胃窦和胃体的ＨｐＤＮＡ指模一致,提示这１８例患者均是单株感染;另有２例胃体菌株表现为两种指模形态,提示为２株Ｈｐ感染．结论广州地区存在Ｈｐ多株感染,但不普遍．     

Pre and post eradication gastric inflammation in Helicobacter pylori-associated duodenal ulcer.

BACKGROUND: Distribution and nature of gastritis are major determinants of clinical outcome of H. pylori infection. The gastric inflammatory changes associated with this infection in developing countries have not been systematically studied. AIMS: To evaluate the inflammatory changes in gastric antrum and corpus in patients with duodenal ulcer and H. pylori infection, before and after H. pylori eradication therapy. METHODS: Histology and H. pylori density were studied in gastric biopsies obtained from 53 consecutive patients with active duodenal ulcer and H. pylori infection. Biopsies were obtained before and 4 weeks after H. pylori eradication therapy, from the anterior and posterior walls of the antrum and corpus, and were evaluated according to the Sydney system. RESULTS: In the pre-H. py/ori eradication antral biopsies, chronic gastritis, active gastritis, atrophy, intestinal metaplasia (IM) and lymphoid follicles / aggregates were seen in 53 (100%), 49 (92%), 11 (21%), 7 (13%) and 28 (53%) patients, respectively. In the corresponding biopsies from gastric corpus, these changes were seen in 49 (92%), 23 (43%), 2 (4%), 2 (4%) and 8 (15%), respectively. All changes except IM were significantly more frequent and of higher grade in the antrum. The grade of chronic gastritis was significantly higher in antrum than corpus; the frequency of gastritis in the antrum and corpus was similar (100% vs. 92%). H. pylori density was also higher in the antrum and correlated well with the grades of chronic gastritis and activity at both sites. Eradication of H. pylori was achieved in 39 patients (74%), and led to significant decrease in gastritis; no change was seen in patients who did not eradicate the organism. CONCLUSIONS: Antral-predominant chronic gastritis and activity are present in more than 90% of patients with H. pylori infection associated with duodenal ulcer, and the grade of gastritis correlates with the density of the organism. Eradication therapy results in improvement of both chronic gastritis and activity.     

Gastric acid secretion of normal Japanese subjects in relation to Helicobacter pylori infection, aging, and gender

BACKGROUND: In Japan, where the incidence of gastric cancer is high, Helicobacter pylori infection could affect gastric acid secretion differently from that in Western countries. The aim of this study was to investigate the relationship between H. pylori infection, acid secretion, aging, and gender in normal Japanese subjects. METHODS: The study comprised 193 Japanese subjects who had undergone routine endoscopy. Gastrin-stimulated acid output was performed during the routine endoscopic examination using the endoscopic method of gastric acid secretory testing (EGT: endoscopic gastrin test), which has been reported previously. H. pylori status was determined by histology, rapid urease test, and serology. RESULTS: Mean EGT values were 3.9 +/- 1.5 mEq/10 min in H. pylori-negative men, 1.6 +/- 2.5 in H. pylori-positive men, 2.2 +/- 0.9 in H. pylori-negative women, and 1.5 +/- 1.2 in H. pylori-positive women. Although acid secretion was lower in H. pylori-positive subjects compared with H. pylori-negative subjects in both men and women, the decrease was more marked in men with H. pylori infection. Multiple linear regression analysis showed that aging is positively associated with gastric acid secretion in the H. pylori-negative subjects, whereas a negative association was found between them in the H. pylori-positive subjects. CONCLUSIONS: In Japanese subjects, aging affects gastric acid secretion differently depending on the status of H. pylori infection. H. pylori infection showed a stronger inhibitory effect on the acid secretion in men than in women. This gender-related difference in the susceptibility of acid secretion to H. pylori infection may explain the higher rates of gastric cancer in men in Japan.     

Characteristics of gastritis in patients with Helicobacter pylori-positive reflux esophagitis

BACKGROUND AND AIM: The influence of Helicobacter pylori on gastric acid secretion differs with the status of gastritis. The histological characteristics of gastritis in H. pylori-positive patients with reflux esophagitis have not been fully investigated. We therefore studied the pattern of endoscopic gastric mucosal atrophy and degree of histological gastritis in such patients. METHODS: Subjects comprised 41 H. pylori-positive patients with reflux esophagitis, 41 age- and sex-matched patients with duodenal ulcer, and 41 patients with early gastric cancer. The endoscopic pattern of gastric mucosal atrophy was reviewed, and the degree of histological gastritis in biopsy specimens from the antrum and corpus was assessed in accordance with the updated Sydney system. RESULTS: The grade of endoscopic and histological gastric mucosal atrophy in patients with reflux esophagitis was significantly lower than that in patients with gastric cancer, and the histological scores for antral atrophy and metaplasia in patients with reflux esophagitis tended to be lower than those in patients with duodenal ulcer. In patients with reflux esophagitis and duodenal ulcer, the scores for antral inflammation and activity tended to be higher than those for the corpus. Conversely, the inflammation and activity score in patients with early gastric cancer showed a corpus-predominant gastritis pattern. CONCLUSION: In H. pylori-positive patients with reflux esophagitis, the degree of endoscopic gastric mucosal atrophy is low and histologically there is an antral-predominant gastritis pattern. Therefore, gastric acid secretion in H. pylori-positive patients with reflux esophagitis may be augmented by H. pylori infection.     

Detection of the intragastric sites at which Helicobacter pylori evades treatment with amoxycillin and cimetidine.

Treatment of Helicobacter pylori infection with amoxycillin is known to reduce the bacterial load to undetectable levels, while not eradicating the infection. It seems, therefore, that bacteria escape treatment at a 'sanctuary site'. This study examined whether such a site existed in the gastric antrum, body, or fundus. Twenty two patients with H pylori infection and duodenal ulcer disease were treated for one week with amoxycillin (500 mg three times a day) and cimetidine (800 mg at night). Before treatment, H pylori was detected throughout all stomachs, and 13C-urea breath testing at least 28 days after treatment confirmed that eradication of H pylori had occurred in no patients. While under treatment, H pylori was sought by conventional methods and by polymerase chain reaction assay and was found in the gastric fundus in 13 of 22 subjects, in the body in 10 of 22, and the antrum in three of 22: the difference between fundus and antrum was significant (p < 0.01). The continued antral infection in three subjects may have resulted from generalised treatment failure as two of three had H pylori detected throughout the stomach, and these two had compiled relatively poorly with treatment. This study suggests that amoxycillin and cimetidine are relatively effective at clearing H pylori from the gastric antrum, but that escape from treatment may occur in the gastric body, and especially the fundus.     

Helicobacter pylori stimulates pepsinogen secretion from isolated human peptic cells

BACKGROUND: Different acid and peptic related gastroduodenal diseases are associated with both increased gastric secretion and Helicobacter pylori infection. Patients with H pylori associated gastritis or duodenal ulcer have increased serum pepsinogen levels which decrease after eradication. The mechanisms of H pylori induced gastric mucosal damage are not completely understood. AIM: To determine the effects of H pylori on pepsinogen secretion from isolated human peptic cells. METHODS: Dispersed human peptic cells were prepared from endoscopically obtained biopsy specimens after collagenase digestion, mechanical disruption, and density gradient centrifugation. H pylori was obtained from gastric biopsies (antrum and body), and cultured in non-selective and selective media. Isolates of H pylori were used at different concentrations (1 - 20 x 10(6) colony forming units (cfu)). RESULTS: H pylori (10(6) - 2 x 10(7) cfu) increased basal pepsinogen secretion in a concentration dependent manner. This stimulus was not observed with Escherichia coli. The increased secretion was in addition to that observed with 0.1 mM histamine and 0.1 mM dibutyryl-cyclic adenosine monophosphate. However, H pylori did not affect either carbamylcholine (0.1-10 microM) or cholecystokinin (1 microM) stimulated pepsinogen secretion. Addition of the nitric oxide synthase inhibitor N(w)-monomethyl-L-arginine (1 mM) inhibited H pylori induced cGMP generation and pepsinogen secretion, which were also reduced in the absence of extracellular calcium. H pylori induced pepsinogen secretion was not affected by the absence/presence of the cagA gene. CONCLUSIONS: H pylori increases pepsinogen secretion from human peptic cells through a calcium and nitric oxide mediated intracellular pathway. This effect is independent of the H pylori virulent cagA gene, and may be a mechanism of H pylori induced gastric mucosal damage.