bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural and Experimental Helicobacter mustelae Reinfection Following Successful Antimicrobial Eradication in Ferrets
Authors: Batchelder Margaret , Fox James G. , Hayward Alison , Yan Lili , Shames Ben , Murphy James C. , Palley Lori 
Published: February 2007

ABSTRACT Background.Recrudescence or reinfection may occur after eradication of Helicobacter pylori in humans. Materials and Methods.We used the ferret Helicobacter mustelae model to investigate the effect of prior infection and eradication on reinfection by experimental and natural routes. Two groups of ferrets with naturally acquired H. mustelae infection were treated with an eradication protocol using amoxicillin, metronidazole, and bismuth subsalicylate. The ferrets were monitored for recrudescence by repeated cultures of endoscopic gastric mucosal biopsies. The ferrets were challenged at 17 months (group I) and 6 months (group II) after eradication with a strain of H. mustelae having a distinctive restriction endonuclease analysis pattern. The eradication protocol was repeated to eliminate the infection produced by experimental challenge. The ferrets were then cohoused intermittently with naturally infected ferrets. Results.The original H. mustelae infection was successfully eliminated by the eradication protocol. No recrudescence was observed in group I for 12 months nor for 3 months in group II after eradication. All ferrets became persistently reinfected with the challenge strain. The infection from the challenge strain was eradicated successfully. No ferrets in group I and all ferrets in group II became infected through cohousing. Conclusions.These results suggest that though prior infection with H. mustelae may confer some protection against reinfection, such protection is not universal in all circumstances; that susceptibility to reinfection by contact with infected animals varies between individuals; and that age may be a factor in this individual variability. These results are applicable to studies of reinfection after eradication of H. pylori in humans.
Characterization and Therapy for Experimental Infection by Helicobacter mustelae in Ferrets
Authors: Czinn Steven J. , Bierman John C. , Diters Richard W. , Blanchard Thomas G. , Leunk Robert D. 
Published: February 2007

ABSTRACT Background.Numerous clinical trials evaluating the efficacy of various antimicrobial compounds against Helicobacter pylori infection have been performed in humans. A convenient animal model for Helicobacter infection would facilitate the evaluation of novel therapies. These experiments were performed to evaluate the use of ferrets as a model of Helicobacter infection. Materials and Methods.Ferrets were infected experimentally with Helicobacter mustelae and subsequently treated with bismuth subsalicylate (BSS) triple therapy (BSS, metronidazole, and amoxicillin), or left untreated. The status of infection and serology was assessed during treatment and for 8 weeks posttreatment. Seven ferrets successfully treated with triple therapy were challenged with H. mustelae and monitored for infection for an additional 5 weeks. Results.Infection of ferrets by H. mustelae was accompanied by gastritis and a specific antibody response. Treatment of H. mustelae‐infected ferrets with BSS suppressed bacterial growth in four of nine animals but did not eradicate infection. Triple therapy eradicated infection in all nine ferrets with a reduction in gastric inflammation. No relapse of infection occurred up to 8 weeks posttherapy. Challenge with H. mustelae of ferrets successfully treated with triple therapy resulted in a 100% rate of reinfection. Conclusions.
H. mustelae infection can be eliminated by triple therapy, but this does not result in protective immunity against reinfection by H. mustelae. This model, using a strain of Helicobacter indigenous to the host, may be useful for assessing therapeutic efficacy of novel therapies for the treatment of human infection by H. pylori.
Helicobacter pylori and Socioeconomic Factors in Russia
Authors: Malaty Hoda M. , Paykov Valeri , Bykova Olga , Ross Allan , Graham David P. , Anneger John F. , Graham David Y. 
Published: February 2007

ABSTRACTBackground.The factors influencing the acquisition and prevalence of Helicobacter pylori infection remain incompletely understood. In Russia, the demographic and socioeconomic factors are relatively similar, allowing investigation of risk factors that might not be identifiable in a more diverse population. Materials and Methods.Sero‐prevalence of H. pylori infection was studied in 520 asymptomatic individuals between the ages of 1 and 75 years, residing in St. Petersburg, Russia. Forty‐four children lived in orphanages or communal apartments. Demographic information and socioeconomic factors were evaluated, including educational level, income, and living conditions. Helicobacter pylori status was evaluated by using an enzyme‐linked immunosorbent assay for anti‐H. pylori IgG. Results.The prevalence of H. pylori infection was 44% in children and 88% in adults (P < .001). In adults, H. pylori prevalence was independent of socioeconomic factors. The crude and the age‐adjusted odds ratios (ORs) in children showed an inverse correlation between the mother's educational level and H. pylori seropositivity [e.g., OR, 1.8; (95% confidence interval (CI) = 1–3.2] for children whose mothers completed only 8 to 10 years of school compared to children whose mothers completed university. Overcrowding in childhood also was associated with increased H. pylori prevalence. Children from orphanages and communal apartments had the highest crowding index and also were at the greatest risk for H. pylori acquisition (age‐adjusted OR, 2.1; 95% CI = 1.2–2.5). Conclusions.The prevalence of H. pylori infection in Russia correlated with socioeconomic factors, suggesting there are differences sufficient to affect H. pylori transmission. The prevalence of H. pylori infection during childhood forms the basis for the variances in prevalence among populations.
Mixed Infection with cagA‐Positive and cagA‐Negative Strains of Helicobacter pylori
Authors: Fantry George T. , Zheng Qiao‐Xi , Darwin Peter E. , Rosenstein Andrew H. , James Stephen P. 
Published: February 2007

ABSTRACT Background
Helicobacter pylori infection has been implicated strongly in the pathogenesis of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric lymphoma, but the reasons for these widely different clinical outcomes are unknown. The aim of this study was to determine whether these differences could be due in part to mixed infection in the same individual, with bacteria having differences in pathogenic factors associated with ulcers. Materials and Methods.The cagA gene of H. pylori was used to test for mixed infection because it is present in only some strains, and its presence has been associated with ulcers. Polymerase chain reaction (PCR) assays for the cagA gene were applied to H. pylori culture isolates and endoscopic gastric aspirates. Individual bacterial clones were tested for genetic similarity by random primer amplification and restriction endonuclease digestion of urease gene PCR products. Results.The majority of H. pylori‐positive patients had strongly cagA‐positive culture isolates and endoscopic samples (62.5% and 69.6%, respectively). However, many of these patients had evidence of mixed infection with cagA negative and cagA positive strais in cultures isolates and endoscopic samples (25% and 17.4%, respectively). Mixed infection was found to be due to genetically unrelated strains in two patients in whom genetic analysis was performed. Conclusion. Mixed infection with differences in substrain pathogenic factors might occur in H. pylori infection and might contribute to differences in clinical outcome.
Double‐blind, Multicenter, Placebo‐Controlled Evaluation Of Clarithromycin And Omeprazole For Helicobacter Pylori‐Associated Duodenal Ulcer
Authors: O'Morain C. , Dettmer A. , Rambow A. , von Fritsch E. , Fraser A. G. 
Published: February 2007

ABSTRACT Background.Eradication of Helicobacter pylori leads to faster ulcer healing and a significant decrease in ulcer recurrence. Clarithromycin is the most effective monotherapy for eradicating H. pylori from the gastric mucosa, and omeprazole frequently is used for the treatment of duodenal ulcer disease, prompting the interest to investigate rigorously the combination of clarithromycin and omeprazole for eradicating H. pylori. Materials and Methods.The aim of this double‐blind, randomized, multicenter (n=30), multinational (n=10) study was to compare clarithromycin and omeprazole with omeprazole monotherapy for the eradication of H. pylori from the gastric mucosa, endoscopic healing, and reduction of symptoms and ulcer recurrence in patients with active duodenal ulcer. Patients with active duodenal ulcer associated with H. pylori infection were randomized to receive omeprazole, 40 mg every morning for 14 days, with either clarithromycin, 500 mg, or placebo three times daily, which was followed by omeprazole, 20 mg every morning for 14 days. Patients underwent endoscopy before enrolling in the study, immediately after finishing treatment, and at 4‐ to 6‐week and 6‐month follow‐up evaluations or at the recurrence of symptoms. Results.Two hundred and eight patients with active duodenal ulcer associated with confirmed H. pylori infection were randomized to treatment with either clarithromycin and omeprazole (n=102) or omeprazole and placebo (n=106). Four to six weeks after treatment was completed, H. pylori was eradicated in 74% (95% confidence interval, 63.0%–82.4%) of patients receiving clarithromycin and omeprazole, compared with 1% (0.0%–6.2%) of patients receiving omeprazole monotherapy (p < .001). Clarithromycin resistance developed in eight patients treated with clarithromycin and omeprazole and in none given omeprazole and placebo. Ulcers, which were healed following treatment in more than 95% of study patients, recurred by the 6‐month follow‐up visit in 10% (5%–19%) of dual therapy recipients, compared with 50% (39%–61%) of those who took omeprazole alone (p <.001). Conclusion. Clarithromycin and omeprazole dual therapy is simple and well‐tolerated and leads to consistently high eradication rates for patients with duodenal ulcer associated with H. pylori infection.
Helicobacter pylori–Positive Duodenal Ulcer: A Long‐Term Double‐Blind Randomized Study in Patients Healed with H2‐Receptor Antagonists
Authors: Suriani R. , Ravizza M. , Pallante C. , Mazzucco D. , Cardesi E. , Colozza M. , Malandrino M. , Oneglio R. , Giacone G. Orso , Dusio P. , Vajo M. 
Published: February 2007

ABSTRACT Background.The NIH Consensus Conference in 1994 (1) concluded that all patients with peptic ulcr disease should be tested and treated for Helicobacter pylori and that further evaluation was needed for patients in remission. Materials and Methods.We evaluated in a double blind randomization 30 patients whose duodenal ulcers had been healed with H2‐receptor antagonists and who remained in remission on maintenance therapy. After ulcer healing and the presence of H. pylori had been confirmed, these patients were randomized to receive eradication therapy or placebo and were followed for a mean period of 23 months. Results.Almost all patients receiving placebo had ulcer recurrence, whereas the patients treated with antibiotics demonstrate a low recurrence rate. Conclusion. These data suggest, for the first time to our knowledge, the importance of treating with antibiotics duodenal ulcer patients whose disease is in remission.
Effect of Omeprazole Therapy on the Survival of Helicobacter pylori, Urease Activity, and Antral Gastric Histology in Patients with Duodenal Ulcer
Authors: Nakshabendi Imad M. , Zhang Quibo B. , Mokhashi Mahesh , Gemmell Curtis G. , Lee Frederick D. , Russell Robin I. 
Published: February 2007

ABSTRACT Background.
Helicobacter pylori is associated with chronic active gastritis and peptic ulceration (PU). Omeprazole is a proton pump inhibitor that is effective in healing PU and reducing gastritis. Previously it has been found that omeprazole has some bacteriostatic activity against H. pylori both in vitro and in vivo and in inhibiting urease activity in vitro. Our aim was to evaluate the effect of omeprazole on H. pylori colonization of the gastric mucosa, urease activity in vivo, and the presence of associated gastritis in patients with duodenal ulcer (DU). Materials and Methods.We studied 12 patients (7 men and 5 women, ages 22–68 yr) with Du larger than 5 mm in diameter with a positive CLOtest (Delta West Ltd., Australia). Omeprazole, 20 mg bid, was given for 8 weeks to each patient, patients were endoscoped at the end of this period to check for healing of DU, and repeat biopsies were obtained from the gastric antrum for histologyical analysis, CLOtest, and culture. Results.DU healed completely in all patients. Likewise in all patients there was significant reduction in the urease activity, from 22.1=4.17 to 1.58 ± 0.92 units/ml (p <.001; 95% confidence interval of the difference between means, 32.7–14.1), and reduced H. pylori density, from 1,403.46 ± 128.23 to 422.5 ± 172.39 colony‐forming units (CFU) per milligram of tissue biopsy (p < .001; 95% confidence interval of the difference between means, 1,486.1–590.5). The numbers of H. pylori were reduced on the gastric mucosa after omeprazole therapy and disappeared in six patients, a result that correlated with a negative CLOtest reading after 24 hours. Conclusion. Omeprazole, 20 mg bid, is capable of reducing H. pylori numbers and urease activity in vivo. There was no significant reduction in the severity of antral gastritis in DU patients studied.
Egg Passage of Rodshaped and Coccoid Forms of Helicobacter pylori: Preliminary Studies
Authors: Enroth Helena , Engstrand Lars 
Published: February 2007

ABSTRACT Background.We used egg passage of bacteria stored in water to evaluate the culturability of the coccoid form of Helicobacter pylori, as a complement to the results obtained from various animal models. Egg passage was performed, as it is a simple, rapid, and well‐characterized old method by which to culture and evaluate culturability of bacteria compared to experiments in animal models. Egg passage has been used in such experiments since 1938 for isolation and growth of, for example, Rickettsiae sp. and Chlamydia sp. Materials and Methods.The rod‐shaped form of H. pylori was produced by plate cultures for 4 and 7 days. The coccoid form of H. pylori was produced by culture on agar plates for 10 days, followed by storage in water. These preparations then were inoculated into the yolk sac of differently aged fertilized eggs. Results.Positive culture was obtained from 14 of 17 eggs (82%) inoculated with rod‐shaped H. pylori compared to 0 of 22 eggs (0%) inoculated with the coccoid form. Conclusion. Culturability of H. pylori is reduced when it converts into the coccoid form produced by starvation and age followed by storage in water for several weeks at room temperature. Egg passage did not raise the culturability of the coccoid form of H. pylori. Our study demonstrates some clear differences between fresh rods and stored cocci forms of H. pylori in terms of culturability when passed through eggs.
Immunohistochemical Detection of Helicobacter pylori in the Surface Mucous Gel Layer and Its Clinicopathological Significance
Authors: Shimizu Toshiki , Akamatsu Taiji , Ota Hiroyoshi , Katsuyama Tsutomu 
Published: February 2007

ABSTRACT BackgroundAttempts have been made to develop an accurate method for detecting Helicobacter pylori in histological sections. Materials and Methods.Biopsy specimens were obtained from the stomachs of 167 patients with gastric ulcer (33), duodenal ulcer (52), gastroduodenal ulcer (15), chronic gastritis (45), and normal mucosa (22) before antimicrobial treatment and from 108 of these patients after treatment. Biopsy specimens were (1) cultured, (2) fixed in 10% buffered formalin, or (3) fixed in Carnoy's solution. The latter method was employed to preserve the surface mucous gel layer (SMGL) covering gastric surface mucous cells. Histological sections were stained with hematoxylin and eosin (H&E), with immunostaining using a commercially available polyclonal anti‐H. pylori antibody. Results.Cultures were positive for H. pylori in 61% of the cases before treatment and in 16% after treatment; by H&E staining using formalin‐fixed materials: 70% and 9%; by immunostaining using formalin‐fixed materials: 78% and 21%; and by immunostaining using Carnoy‐fixed materials: 85% and 41% of biopsy speciemens, respectively. The difference in detection rates between materials fixed in formalin and those in Carnoy's solution was due to the detection of H. pylori in the SMGL by the latter, especially after antimicrobial treatment. Conclusions.Immunostaining for H. pylori using materials fixed in Carnoy's solution revealed H. pylori in the SMGL as well as on the surface mucous cells and in the gastric pits and permitted the optimal detection of H. pylori in tissue sections.
Serum and Gastric Luminal Epidermal Growth Factor in Helicobacter Pylori—Associated Gastritis and Peptic Ulcer Disease
Authors: Lynch Damien A. F. , Mapstone Nicholas P. , Lewis Fraser , Pentith Judith , Axon Anthony T. R. , Dixon Michael F. , Quirke Phillip 
Published: February 2007

ABSTRACT Background
Helicobacter pylori is the cause of chronic (type B) gastritis, duodenal ulceration (DU), and gastric ulceration (GU). Smoking is associated with delayed ulcer healing. Epidermal growth factor (EGF) is produced in the salivary and Brunner's glands of the upper gastrointestinal tract, inhibits gastri acid secretion, and is a powerful mitogen. Materials and Methods.We sought to determine gastric luminal EGF (GL‐EGF) in smokers and patients with Hp‐associated DU and the effect of Hp eradication. Our aim was to determine GL‐EGF in patients with GU and the effect of ulcer healing and to measure serum EGF in patients with Hp gastritis with or without DU disease. Results.GL‐EGF was reduced in smokers compared to control (p= .008). Subjects with HP gastritis had reduced GL‐EGF compared to controls (p= .0002). There was no difference in GL‐EGF between Hp‐positive subjects who had DU and those with chronic gastritis alone. Eradication of Hp from those patients with DU had no effect on the low levels of GL‐EGF. There was no difference between GL‐EGF in Hp gastritis alone and in Hp‐associated active GU. GL‐EGF fell after ulcer healing (p= .04), a difference confirmed by analysis of paired samples from patients before and after ulcer healing (p= .03). There was no difference in serum EGF between controls and subjects with Hp infection. There was no difference in serum EGF in subjects with DU‐associated and non‐ulcer‐associated gastritis. Conclusions.Subjects with Hp gastritis, or those who smoke, had low concentrations of GL‐EGF regardless of whether DU was present. Eradication of Hp did not return the concentrations of GL‐EGF to normal in DU subjects. Individuals with Hp gastritis and inactive GU had low levels of GL‐EGF compared to non‐ulcer Hp infection. The relative increase in GL‐EGF that occurred with ulceration of the gastric mucosa may have resulted from the development of an ulcer‐associated cell lineage. Serum EGF did not play a role in the pathogenesis of Hp gastritis or of associated DU ulcer disease.
Development of a Murine Model of Helicobacter pylori Infection
Authors: Lachman Lawrence B. , Ozpolat Bulent , Rao Xiao‐Mei , Graham David Y. , Osato Michael 
Published: February 2007

Background.A murine model for Helicobacter pylori infection could facilitate vaccine development. This study was designed to determine the effect of various conditions of dose, frequency of administration, and fasting on H. pylori infection of mice.Materials and Methods.Balb/c and C3H/HeN mice were inoculated orogastrically with clinical isolates of H. pylori grown in liquid culture. At 2‐week intervals, the stomachs were removed for secondary culture on horse blood agar and for histological analysis. H. pylori from secondary cultures or homogenized stomach tissue from infected mice was inoculated a second time in naïve animals.Results. H. pylori was cultured with high frequency only from the stomachs of C3H/HeN mice. Fasting the mice and increasing the number of organisms inoculated did not increase the rate of infection. Histological analysis detected no inflammation, but mucus depletion and erosion were present in the stomachs of C3H/HeN mice. H. pylori organisms were not observed. Secondary cultures of H. pylori or homogenized infected stomach tissue did not cause infection when inoculated in naïve mice.Conclusions.Clinical isolates of H. pylori transiently infect C3H/HeN mice. This murine model is suitable for testing oral vaccines. Effective vaccination against H. pylori could prevent transient infection and reduce subsequent gastritis.
Clarithromycin Dual Therapy Regimens for Eradication ofHelicobacter pylori: A Review
Authors: Pipkin Graham A. , Dixon Jonathan S. , Williamson Russell , Wood John R. 
Published: February 2007

Background.Peptic ulcer disease can be cured by eradication ofHelicobacter pyloriduring treatment to heal the ulcer. Dual therapy regimens were among the first to be granted approval for use. Reports of dual therapies including clarithromycin as the sole antibiotic are reviewed.Methods.Reports were identified from literature up to May 1997. Information reviewed included patient population, medical diagnosis, trial design, eradication regimens, andH. pylorieradication rates. The great diversity between studies limits formal meta‐analysis but a measure of relative efficacy has been obtained by comparsion of eradication rates derived by clearly defined methods and by pooling data.Results.Seventy‐five reports of trials with 104 dual therapy treatment arms were reviewed.H. pylorieradication rates reported with ranitidine bismuth citrate plus clarithromycin range from 70–96% with a pooled observed rate of 85%. With omeprazole plus clarithromycin, reported eradication rates range from 27–90% with the pooled reported rate being 66%. Few data are available with either lansoprazole or ranitidine hydrochloride plus clarithromycin.Conclusion.HighH. pylorieradication rates derived by consistent and clearly defined methods have been seen with ranitidine bismuth citrate plus clarithromycin. Lower and more variable rates are reported with clarithromycin and either a proton pump inhibitor or a histamine H2‐receptor antagonist.
Comparison Between a Rapid Off ice‐Based and ELISA Serologic Test in Screening for Helicobacter pylori in Children
Authors: Elitsur Y. , Neace C. , Triest W.E. 
Published: February 2007

Background.The rapid diagnostic serological test for detection of Helicobacter pylori (H. pylori) infection in children has a significant advantage over the standard enzyme immunoassay (EIA) method, for its simplicity and rapid availability of results in a physician’s office setting. We compared the immunochromatographic test with a standard enzyme immunoassay test in the pediatric population.Materials and Methods.A retrospective analysis of 1147 serum samples from asymptomatic children and prospective analysis of 62 serum samples from symptomatic children undergoing diagnostic upper endoscopy were evaluated for the detection of H. pylori antibody by two commercially available serology tests. Each serum sample was tested by a rapid test (FlexSure® HP, SmithKline Diagnostics, Inc.) and compared to the standard EIA method (HM‐CAP, Enteric Products, Inc.).Results.The rapid test, FlexSure® HP, was comparable to the rapid EIA test in screening for H. pylori infection in symptomatic and asymptomatic children with sensitivity and specificity of 83–90% and 90–100%, respectively. Both methods had a comparable sensitivity and specificity for the detection of H. pylori‐associated gastritis (60–70% and 94%, respectively).Conclusion.The rapid test is comparable to the standard EIA test and may be used by physicians in symptomatic children. The use of FlexSure® HP as a screening tool for the prevalence of H. pylori infection in asymptomatic children may be limited by its low positive predictive value compared to the EIA method.