Direct Transmission of H. pylori from Challenged to Nonchallenged Mice in a Single Cage

To understand whether direct transmission of H. pylori occurs from infected mouse to noninfected mouse, the system using a mouse model we developed previously was tested. Six nude mice were challenged with H. pylori inocula; one group consisted of one challenged nude mouse 1 week after inoculation raised with four nonchallenged nude mice in a single cage. For the single cage, a polycarbonate cage or a mesh-floor cage was used. Then three groups were kept in a polycarbonate cage and the other three groups kept in a mesh-floor cage to avoid H. pylori transmission through stool. After coraising for 1, 2, or 3 weeks, all mice were sacrificed to determine the existence of H. pylori in the stomach, saliva, and stool by culture or PCR and H. pylori-associated gastritis. RAPD fingerprinting patterns using different primers of isolated strains from challenged and nonchallenged mice were compared to understand the origin of transmitted strains. During 3 weeks after coraising of H. pylori challenged and nonchallenged mice, H. pylori was detected in the stomachs in 3 of 12 nonchallenged mice in the polycarbonate cage and in 2 of 12 nonchallenged mice in the cage with a steel mesh floor. H. pylori was detected from saliva or stool in two nonchallenged, infected mice in the polycarbonate cage. Moreover, RAPD fingerprinting using different primers of the total five strains isolated from five nonchallenged, infected mice in both cages showed the same pattern and concordance with that of the challenged strain and the strains isolated from challenged mice. It is demonstrated that intimate interaction is the cause of H. pylori transmission via saliva and stool.     

A newly developed PCR assay ofH. pylori in gastric biopsy,saliva, and feces

We have recently developed a new PCR assay for the detection ofH. pylori. In this study, the polymerase chain reaction (PCR) assay was used to detectH. pylori in 88 gastric biopsy, 85 saliva, and 71 fecal specimens from 88 patients.H. pylori infection was confirmed in 71 of 88 patients by culture and/or histological stain of gastric biopsies. Serum IgG antibody toH. pylori was also measured and resulted in 97% sensitivity and 94% specificity.H. pylori DNA was detected by the PCR assay in gastric biopsy specimens from all 71 patients (100% sensitivity) with proven gastricH. pylori infection but not from 17 noninfected patients (100% specificity). In saliva specimens,H. pylori DNA was identified in 57 of the 68 patients (84%) with proven gastricH. pylori infection and in three of the 17 patients without gastricH. pylori infection. However, the PCR assay was only able to detectH. pylori DNA in the feces from 15 of 61 patients (25%) with proven gastricH. pylori infection and one of the 10 patients without gastricH. pylori infection. The results show that the PCR assay is reliable for detecting the presence ofH. pylori in gastric biopsy and saliva specimens. The data indicate thatH. pylori exists in a higher prevalence in saliva than feces and that the fecal-oral route may be an important means of transmission of this infection in developing countries but not as significant as previously suspected in the developed countries. It is likely that the oral-oral route is more prominent.     

Serologic Evidence for Fecal–Oral Transmission of Helicobacter pylori

Helicobacter pylori infection is among the most prevalent infections in the world and a key cause of gastric diseases; however, its route of transmission remains unclear. This study aimed to assess the potential for fecal–oral transmission of H. pylori by leveraging its association with a disease with known etiology. Utilizing serology data from the National Health and Nutrition Examination Survey (NHANES 1999; N = 6,347), the association between H. pylori and hepatitis A virus (HAV), a sensitive indicator for fecal–oral exposure, was assessed. Survey-weighted kappa and multiple logistic regression were used to quantify the association between H. pylori and HAV after controlling for age, sex, race, poverty, birthplace, crowding, smoking, and alcohol use. Concordant serological results were found among 69.8% of participants (survey-weighted κ = 0.30, 95% confidence interval [CI] = 0.26, 0.35). The adjusted odds of H. pylori seropositivity were over two times higher after adjusting for confounders (odds ratio = 2.27, 95% CI = 1.79, 2.87). Results from this study suggest H. pylori and HAV infections are strongly associated. Since HAV is primarily transmitted through the fecal–oral route, fecal–oral transmission may be an important pathway for H. pylori spread.     

Comparison of cytotoxin genotypes of Helicobacter pylori in stomach and saliva

We have previously reported a high prevalence of H. pylori DNA in saliva. In this study, the cytotoxin genotypes of H. pylori strains from both stomach and saliva were compared in 31 patients with gastritis and peptic ulcer. The cagA, vacA m1, vacA m2, and vacA s1 genotypes were analyzed by PCR. The 417 bp PCR products from three patients were also subjected to DNA sequencing analysis. There was 95% agreement between stomach H. pylori isolates and their corresponding saliva DNA in at least one cytotoxin genotype; 86% agreement with two cytotoxin genotypes; 59% agreement with three cytotoxin genotypes; and 27% agreement with all four cytotoxin genotypes studied. DNA sequencing from three patients showed 78.0%, 64.0%, and 66.9% homology of H. pylori from both sources, respectively. The data suggest that more than one H. pylori strain may exist in the stomach and saliva in the same patient.     

Helicobacter pylori in the Oral Cavity:

To test the hypothesis that Helicobacter pylori may be transmitted by the oral–oral route, we applied nested PCR and DNA sequencing to detect and analyze H. pylori DNA in the oral cavity of 20 adult patients undergoing endoscopy. Dental plaques of molars, premolars, and incisors and saliva were collected. Additional paraffin-embedded gastric biopsies were analyzed in four patients. Two sets of highly sensitive and specific primers, EHC-U/EHC-L and ET5-U/ET-5L directed to a 860-bp fragment of H. pylori DNA, were used in the nested PCR. Eight patients had an active infection in the stomach determined with the [¹³C]urea breath test and the other 12 were negative. Nested PCR showed that all 20 subjects (100%) were positive for H. pylori in the oral cavity. DNA sequencing demonstrated that all tested PCR products of the expected size from the oral samples have more than 97% identity with that from H. pylori type strain ATCC 43629. However, sequences differed in oral samples from different subjects as well as between different oral locations and gastric biopsies within the same individuals. In conclusion, the oral cavity may be a permanent reservoir for H. pylori and can harbor multiple H. pylori strains at the same time.     

Paradoxical Role of Helicobacter pylori Infection: Protective Effect Against Ethanol-Induced Gastric Mucosal Injury in Mongolian Gerbils

We investigated the effect of ethanol (a representative necrotizing agent) on gastritis induced by Helicobacter pylori infection in Mongolian gerbils. Seventy-eight gerbils were used. Four and 12 weeks after H. pylori inoculation, 30% ethanol was administered into the stomach. The stomachs were removed after 30 min, the intramucosal prostaglandin (PG) E₂ concentration was measured, and histopathology was recorded. H. pylori infection caused chronic active gastritis, gastric erosion, hypersecretion of mucin from gland mucus cells, and a rise in the activity of intramucosal PGE₂. After ethanol administration, gastric erosion was significantly less in animals infected with H. pylori than in uninfected animals. In conclusion, in the early stage of H. pylori infection, accentuation of intramucosal PGE₂ and hypersecretion of mucin from gland mucus cells have a protective effect against gastric mucosal injury induced by necrotizing agents.     

Influence of bile reflux and Helicobacter pylori infection on gastritis in the remnant gastric mucosa after distal gastrectomy

Background Two main pathogenic factors, bile reflux and Helicobacter pylori infection, have been identified in the remnant stomach, but it is still unclear which factor is important in the pathogenesis of gastritis in the remnant stomach after distal gastrectomy.Methods In 184 patients who had had distal gastrectomy performed using the Billroth-I procedure (B-I; n-106), Billroth-II procedure (B-II; n-36), and jejunal interposition (J-I; n-42) we examined the severity of remnant gastritis endoscopically and carried out examinations for H. pylori infection and histological examination.Results The endoscopic severity of remnant gastritis was grade 1 or more in 101 of the 106 B-I patients (95.3%) and in all 36 B-II patients (100%). But, of the 42 J-I patients, the grade was 0 in 33 (78.6%). The endoscopic severity of remnant gastritis was significantly milder for J-I than for B-I (P < 0.001) and B-II (P < 0.001). H. pylori infection was confirmed in 59 of the 106 B-I patients (55.6%), 21 of the 36 B-II patients (58.3%), and 32 of the 42 J-I patients (76.1%). The rate of H. pylori infection was higher for J-I patients than for B-I (P < 0.05), but not for B-II patients (P = 0.1495). The severity of chronic and active inflammatory cellular infiltration tended to be inverse proportional relation with the endoscopic severity of the remnant gastritis. Furthermore, the histological inflammation and activity scores of H. pylori-positive patients were higher than those of H. pylori-negative patients, without regard to the endoscopic grade of gastritis.Conclusions Reconstruction techniques play an important role in the prevention of bile reflux, and we found that endoscopically more severe remnant gastritis was associated with a lower rate of H. pylori infection and with a lower degree of inflammatory cellular infiltration.     

Atrophic Corpus Gastritis and Helicobacter pylori Infection in Primary Biliary Cirrhosis

Chronic atrophic corpus gastritis, termed as autoimmune corpus gastritis or type A gastritis, and primary biliary cirrhosis (PBC) are characterized by a common immunological process against the exocrine glandular structures of both the stomach and bile duct. However, there has been controversy over whether atrophic corpus gastritis is associated with PBC. Recently, it has been suggested that Helicobacter pylori plays an important role in the early stage of atrophic corpus gastritis due to the induction of autoantibodies that are reactive with a protein in the gastric parietal cells. One hypothesis is that molecular mimicry, possibly resulting from H. pylori infection, might be responsible for initiating an autoimmune response in a predisposed host due to cross-reactivity among gastric mucosal, bile ductular, and bacterial antigens. The aim of this study is to assess whether atrophic changes of the gastric corpus could affect patients with PBC, and to determine the correlation with H. pylori infection. Sixteen patients with PBC were enrolled in this study. All patients were examined by serological studies of anti-pyruvate dehydrogenase (PDH) antibody, anti-H. pylori antibody, gastrin and vitamin B₁₂. Gastroscopy was performed on all patients in order to verify the histological findings and to microscopically identify H. pylori. Atrophic corpus gastritis was found in 2 of 16 patients with PBC (12.5%), one of whom was confirmed to have pernicious anemia, a developed stage of atrophic corpus gastritis. H. pylori infection in the gastric corpus and the anti-H. pylori antibody were found in 7 (43.8%) and 11 (68.8%) of 16 patients, respectively. Anti-H. pylori antibody was confirmed to be positive in both of the patients with atrophic corpus gastritis, although H. pylori was absent in the gastric biopsy specimen. There was a positive correlation between anti-PDH antibodies and anti-H. pylori antibodies in sera from patients with PBC. Atrophic corpus gastritis is not frequently involved in PBC. However, H. pylori is a possible pathogenic factor in atrophic corpus gastritis in PBC patients because of the presence of anti-H. pylori antibody. A positive correlation between the titer of anti-PDH antibodies and the titer of anti-H. pylori antibodies was confirmed. Consequently, H. pylori infection could induce autoimmune responses in the development of both PBC and atrophic corpus gastritis. H. pylori infection associated with PBC requires further study.     

Gastric Emptying is Altered with the Presence of Gastritis

Helicobacter pylori infection and gastritis can cause symptoms suggestive of altered gastrointestinal function; however, it is unclear if H. pylori influences gastric motility. This study assessed gastric emptying rates in mouse models of gastritis. Gastritis was induced in C57BL/6 mice via ethanol treatment or via challenge with H. pylori or H. felis. Gastric emptying rates of nutrient and non-nutrient liquids were assessed with the non-invasive ¹³C-breath test, and the results were compared to healthy mice. Gastric emptying of the non-nutrient liquid was unaltered with the presence of gastritis; however, gastric emptying of the nutrient liquid was accelerated after a 4-week infection with H. pylori. H. felis infection and ethanol treatment caused a more severe gastritis and disruptions to the normal gastric emptying. Changes to gastric emptying in mouse models of gastritis are associated with the presence of nutrients. Altered gastric emptying may contribute to symptoms commonly reported in humans with gastritis.     

Association Between Helicobacter pylori Infection in Mothers and Birth Weight

Helicobacter pylori infection may cause intrauterine growth restriction (IUGR). However, it is unknown whether the growth of children from H. pylori-infected mothers is also affected or whether transmission of infection from mother to child occurs. This study aimed to determine if maternal H. pylori infection was associated with IUGR and low birth weight in a mouse model, and whether transmission of infection from mother to infant occurs. Female C57BL/6 mice were inoculated with H. pylori (n = 18) or water (control; n = 18) via gavage. Mice were mated at 6 weeks postinfection, with half of the mice sacrificed after 2 weeks of gestation. The remaining mice gave birth and a third of the litter was weighed and sacrificed at birth, during milk feeding (1.5 weeks), and during solid feeding (4 weeks). Stomachs of all mice and whole foetuses were cultured for the presence of H. pylori. There were no differences in litter size or foetus weight between control and H. pylori-infected mice. Pups from infected mothers had a lower weight during milk feeding (control, 5.91 ± 0.23 g; H. pylori, 4.59 ± 0.16 g; p < 0.05) and solid feeding (control, 12.73 ± 0.58 g; H. pylori, 10.01 ± 1.02 g; p < 0.05). H. pylori was not detected by culture in the pups at any age. H. pylori infection in mothers was associated with a decrease in infant weight during milk feeding and after weaning. Transmission of infection from mother to infant was not detected by culture, suggesting that decreased baby weight may be due to decreased milk supply or altered nutrition from the mother.     

Frequency of Helicobacter pylori and Gastritis in Healthy Subjects without Gastrointestinal Symptoms

To investigate the frequency of Helicobacter pylori and gastritis in asymptomatic adults, 30 healthy volunteers underwent upper endoscopy. Biopsy specimens were obtained from the corporeal and antral mucosa of the stomach. The specimens were examined by light microscopy for gastritis and the occurrence of H. pylori. In 12 subjects signs of gastritis were noted at endoscopy, but only in 7 of them was this diagnosis confirmed histologically. No other abnormalities were observed by the endoscopist. Histologic examination was normal in 17 subjects, but in 13 subjects (43%) inflammation was found in the gastric specimens. Ten had inflammation both in the corpus and in the prepyloric specimens, and in six of these subjects H. pylori was discovered. H. pylori was only found in subjects with inflammation in both the corpus and the antrum. Subjects with gastritis were slightly older than subjects with normal gastric mucosa (median age, 47 versus 37 years; not significant). In the group of subjects with gastritis, persons with H. pylori were older than those without (median age, 53.5 versus 36 years; p = 0.05). The results of our study indicate that gastritis is present before colonization with H. pylori occurs. This could imply that H. pylori is not the cause of gastritis but that the presence of gastritis is a prerequisite for colonization of the bacterium in the stomach.     

Helicobacter pylori infection accelerates human gastric mucosal cell proliferation

Helicobacter pylori causes chronic atrophic gastritis and intestinal type gastric cancer arises against a background of atrophic gastritis. Increased proliferation of epithelial cells is an important indicator of increased risk for gastric adenocarcinoma. We investigated gastric mucosal cell proliferation inH. pylori-associated gastritis and the effect of eradication therapy on this proliferation in 45 patients endoscopically diagnosed (31 with persistent eradication and 14 in whomH. pylori) recurred.H. pylori status was determined by culture and histology in biopsied specimens from the gastric antrum and corpus. Eradication of the infection was defined as reversal to negative on both tests. In vitro Ki-67 immunostaining of endoscopic biopsy specimens was used to measure mucosal cell proliferation inH. pylori-associated gastritis before and after therapy. The proliferative zone was defined as the distance of Ki-67-positive gastric epithelial cells between the highest and the lowest cells. In patients in whomH. pylori was eradicated, cell proliferation in both the antral and corpus mucosa had decreased 4 weeks after completion of the eradication therapy (P<0.01,P<0.001), and 6 months later, it had markedly decreased (P<0.05,P<0.05) and returned to normal. In patients in whomH. pylori recurred, only antral epithelial cell proliferation was reduced 4 weeks after eradication therapy, but whenH. pylori recurred, determined by culture and histology, cell proliferation level was the same as that before eradication. These results suggest thatH. pylori infection accelerates cell proliferation in gastric mucosa and may play a causal role in the chain of events leading to gastric carcinoma.     

Diagnosis of Helicobacter pylori Infection from Antral Biopsies in Pediatric Patients: Is Urease Test that Reliable?

Our objectives were to determine if the urease (CLO) test alone is a reliable diagnostic test for H. pylori gastritis in children and if the density of H. pylori influences the CLO test result. We performed a combined retrospective and prospective study reviewing the results of CLO-test and histology of gastric mucosal biopsy from 67 patients (35 females) with H. pylori gastritis. Two antral biopsies were inoculated on the CLO-test and two processed for histology to grade the severity of gastritis and H. pylori density. The mean age of patients was 11 years (sd ± 4.53). Only 50 patients tested positive for H. pylori on CLO-test, whereas all patients were positive on histology. %The sensitivity of the CLO-test was 75%. There was a significant association between CLO-test positivity and the density of H. pylori organisms on histology (P < 0.01), and with the severity of gastritis (P < 0.001) by the Pearson chi-square test. However, there was no association between the density of H. pylori and severity of gastritis. In conclusion, the CLO-test is not reliable as a sole diagnostic test for H. pylori gastritis in children because of a significant number of false negatives. Histologic examination of gastric mucosal biopsy is superior to the CLO-test in diagnosing H. pylori infection.     

Effect of eradicating Helicobacter pylori on the development and reversion of atrophic gastritis in an animal study

OBJECTIVE : To investigate the effect of eradicating Helicobacter pylori on the development and reversion of atrophic gastritis in an animal study. METHODS : One hundred and ten grade II C57BL/6 female mice were randomly divided into experimental (60 mice) and control (50 mice) groups. The mice in the experimental group were infected with the SS1 H. pylori strain, then randomly subdivided into group A and group B (30 mice in each group). Group A and group B received a dose of standard bismuth triple therapy 6 and 12 months after infection, respectively. Ten mice in each group were killed before the therapy, then at 3 and 6 months after completion of the therapy (a total of 30 mice). The histopathological features of the glandular stomach were graded using a method analogous to the Sydney system and kinetic changes in the mucosal epithelial cells of the glandular stomach were examined using anti‐BrdU immunohistochemical staining and flow cytometry. RESULTS : All mice that received eradication therapy tested negative for Helicobacter pylori. Significant improvement in chronic active gastritis was observed after the eradication of H. pylori in both groups A and B. Atrophic changes were not seen at any time interval in group A, whereas in group B, atrophic changes were seen 12 months after H. pylori infection and no significant changes in the degree of atrophy were observed 3 and 6 months after the eradication of H. pylori. The cell kinetic indices (S‐phase cell percentage, proliferation index and labeling index) in the experimental group before the eradication of H. pylori were significantly higher than those in the control group at any time (P < 0.01), and significantly decreased 3 months after the eradication of H. pylori compared with those before therapy (P < 0.01). The cell kinetic indices showed no significant difference 6 months after the eradication of H. pylori compared with those in the control group at the same time intervals (P > 0.05). CONCLUSIONS : The present study suggests that the eradication of H. pylori can reduce gastric mucosal inflammation and change the epithelial cell kinetics of the stomach. It was found that early treatment can prevent the formation of mucosal atrophy. When atrophy has established, eradication of H. pylori can no longer reverse the change but may prevent its progress.     

Is cranberry juice effective in the treatment and prevention of Helicobacter pylori infection of mice?

OBJECTIVE: It is well known that eradication of Helicobacter pylori infection results in healing of peptic ulcer and regression of gastric mucosal inflammation. Cranberry juice beverages have been shown to achieve good results in the prevention of recurrent urinary tract infection. The present study aimed to investigate whether a cranberry juice cocktail could eradicate or prevent H. pylori infection in mice. METHODS: In the therapeutic trial, C57BL/6 mice were infected with H. pylori and 2 weeks later, 80 mice were randomly allocated into four groups: Group A, cranberry juice (0.5 mL/mouse, p.o. daily for 30 days); Group B, triple therapy (amoxycillin 50 mg/kg, bismuth subcitrate 6.15 mg/kg, and metronidazole 22.5 mg/kg, daily for 14 days); Group C, a combination of cranberry juice and triple therapy; Control Group, the mice were infected with H. pylori and left untreated. The mice were killed after 24 h and 4 weeks and H. pylori infection status was assessed by rapid urease test and by culture and histology, respectively. In the prevention trial, 40 mice had oral cranberry juice for 30 days. In the last 5 days (days 26?30), the mice were divided into four groups: Group A, challenged orally with H. pylori three times on days 26, 28 and 30 when the mice were not given cranberry juice; Group B, challenged with H. pylori suspended in cranberry juice; Group C, challenged with H. pylori 6 h after receiving juice; Control group, no cranberry juice, but challenged with H. pylori. Two weeks later, the mice were killed to assess the status of H. pylori infection. RESULTS: The clearance rates at 24 h after treatment in groups A, B and C were 80%, 100%, and 90%, respectively (P < 0.01 as compared with Control group, two tailed Fisher's Exact Probability Test). Four weeks after cessation of treatment the eradication rates in groups A, B and C were 20% (P = 0.474, two tailed Fisher's Exact Probability Test), 80% and 80%, respectively (P < 0.01). None of the mice were clear of H. pylori infection. CONCLUSIONS: Cranberry juice can clear H. pylori infection in mice with a clearance rate of 80%, but the eradication rate was low (20%). Cranberry juice was not effective in preventing H. pylori infection in the mice used in this study.     

Apoptotic Depletion of Infiltrating Mucosal Lymphocytes Associated with Fas Ligand Expression by Helicobactor pylori-Infected Gastric Mucosal Epithelium: Human Glandular Stomach as a Site of Immune Privilege

H. pylori infection almost invariably results in chronic gastritis, but only a proportion of patients develops severe destruction of epithelial glandular structure or peptic ulcer. To confirm the recent data obtained in testis and eye, showing that Fas ligand is involved in the phenomenon of immune privilege, expression of Fas receptor and its ligand of the stomach was investigated in a panel of gastric biopsies obtained from patients H. pylori-positive (N = 42) and with H. pylori-negative (N = 18) by two-color flow cytometry. The results show that membrane-bound Fas ligand protein is constitutively expressed on freshly isolated human gastric mucosal epithelium coupled with infiltrating lymphocytes. There was significant overexpression of Fas receptor and its ligand, and a higher frequency of apoptotic cell death detected by TUNEL in epithelium and infiltrating lymphocytes in H. pylori-infected patients. These findings suggest that involvement of Fas receptor and its ligand system contributes to some extent to mucosal damage in H. pylori-associated gastritis. However, the more specific findings are apoptotic depletion of invading mucosal lymphocytes associated with Fas ligand expression by gastric epithelium. These provide the first direct quantitative evidence to support Fas receptor counterattack and/or paracrine fratricide as a mechanism of immune privilege in vivo in the H. pylori-infected glandular stomach.     

The role of the gastrointestinal microbiome in Helicobacter pylori pathogenesis

The discovery of Helicobacter pylori overturned the conventional dogma that the stomach was a sterile organ and that pH values < 4 were capable of sterilizing the stomach. H. pylori are an etiological agent associated with gastritis, hypochlorhydria, duodenal ulcers, and gastric cancer. It is now appreciated that the human stomach supports a bacterial community with possibly 100s of bacterial species that influence stomach homeostasis. Other bacteria colonizing the stomach may also influence H. pylori-associated gastric pathogenesis by creating reactive oxygen and nitrogen species and modulating inflammatory responses. In this review, we summarize the available literature concerning the gastric microbiota in humans, mice, and Mongolian gerbils. We also discuss the gastric perturbations, many involving H. pylori, that facilitate the colonization by bacteria from other compartments of the gastrointestinal tract, and identify risk factors known to affect gastric homeostasis that contribute to changes in the microbiota.     

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.     

Critical role of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> in the pattern of gastritis and carditis in residents of an area with high prevalence of gastric cardia cancer

We have investigated the role of Helicobacter pylori infection and of other risk factors of gastritis and carditis in residents of a high-risk area for gastric cardia cancer. During a national population-based endoscopic survey, 508 randomly-selected participants aged ≥40 were enrolled. Mucosal biopsies were obtained from six standard sites. Polymorphonuclear (PMN) and mononuclear (MN) infiltration and combined inflammatory scores (CIS) for chronic gastritis and H.pylori were assessed. Relationships of H.pylori and reflux esophagitis with these variables were calculated for cardia and non-cardia subsites. Both PMN and MN infiltrations correlated strongly with H.pylori infection. For PMN the relationship was maximum for the antrum (odds ratio (OR) = 9.4 (5.2–17.1)) and minimum for the gastric body (OR = 1.7 (1.0–2.9)). There was a significant relationship between carditis and H.pylori (OR = 2.8 (1.7–4.9)). A similar relationship was obtained for MN infiltration. In 56% of subjects the mean MN score for the corpus was equal to or greater than that for the antrum. For 59% of subjects the MN score for the cardia was greater than or equal to the antral score. Use of logistic regression revealed that was the main risk factor for gastritis and carditis in all sites. There was an inverse relationship between reflux esophagitis and carditis. H.pylori is the main risk factor for gastritis for all sites of the stomach including the cardia; but this relationship is stronger for the antrum and cardia than for the body. Continuous cardia inflammation may contribute to the high incidence of gastric cardia cancer in this region.     

Anti-Inflammatory Effects of Pravastatin on Helicobacter Pylori-Induced Gastritis in Mice

Pravastatin, an HMG-CoA reductase inhibitor, exerts anti-inflammatory effects via several mechanisms including induction of endothelial nitric oxide synthase (eNOS). We investigated the effect of pravastatin on Helicobacter pylori-induced gastritis in mice. Mice with or without H. pylori infection received intraperitoneal pravastatin daily for 1 week. Expression of eNOS mRNA and tumor necrosis factor-α mRNA and myeloperoxidase activity in gastric tissue was determined. Myeloperoxidase activity was reduced in a dose-dependent manner by pravastatin, with activity inhibited by 53.5 and 73.7% at doses of 0.3 and 1 mg/kg, respectively. At a dose of 1 mg/kg, pravastatin reduced the level of tumor necrosis factor-α mRNA by 52.7%, while it did not affect eNOS expression. Pravastatin had no effects on these inflammatory parameters in uninfected mice. Pravastatin did not affect the viability of H. pylori. In conclusion, pravastatin exerts an anti-inflammatory effect on H. pylori-induced gastritis in mice without affecting eNOS expression.