bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural and microtextural characterization of oxide scale on steel using electron backscatter diffraction
Authors: Birosca S. , Dingley D. , Higginson R. L. 
Published: February 2004

SummaryHigh‐temperature oxidation of steel has been extensively studied. The microstructure of iron oxides is, however, not well understood because of the difficulty in imaging it using conventional methods, such as optical or electron microscopy. A knowledge of the oxide microstructure and texture is critical in understanding how the oxide film behaves during high‐temperature deformation of steels and more importantly how it can be removed following processing. Recently, electron back‐scatter diffraction (EBSD) has proved to be a powerful technique for distinguishing the different phases in scales. This technique gives valuable information both on the microstructure and on the orientation relationships between the steel and the scale layers. In the current study EBSD has been used to investigate the microstructure and microtexture of iron oxide layers grown on interstitial free steel at different times and temperatures. Heat treatments have been carried out under normal oxidation conditions in order to relate the results to real steel manufacturing in industry. The composition, morphologies, microstructure and microtexture of selected conditions have been studied using EBSD.
Progressive steps in the development of electron backscatter diffraction and orientation imaging microscopy
Authors: Dingley D. 
Published: February 2004

SummaryTen years ago electron backscatter diffraction (EBSD) became available to a wider group active in materials research. This paper highlights some of the more significant developments in camera technology and software developments that have arisen since then. The use of slow‐scan charge couple device cameras for phase identification and rapid determination of orientation image micrographs is reviewed. The current limiting spatial resolution of the technique is shown to be less than 10 nm. A procedure for improving lattice spacing measurement by utilizing the full resolution of the camera is described with experimental measurements on silicon and nickel showing relative errors of plus/minus 3%. An investigation of partially recrystallized aluminium shows how the recrystallized fraction can be extracted with confidence but that the mapping of substructure in the highly deformed regions is questionable. Phase identification is described for complex cases in which the phase data tabulated in standard databases do not correspond to what is observed in the EBSD patterns. Phase mapping in a complex mineral in which chemical data and EBSD data are collected simultaneously is shown to be improved by recording both the chemical and the EBSD data into computer memory and proceeding with the phase discrimination and orientation measurement in off‐line analysis.
False Negative Urea Breath Tests with H2‐Receptor Antagonists: Interactions Between Helicobacter pylori Density and pH
Authors: Graham David Y. , Opekun Antone R. , Jogi Medhavi , Yamaoka Yoshio , Lu Hong , Reddy Rita , El‐Zimaity Hala M.T. 
Published: February 2004

ABSTRACTBackground.  We studied the effects of famotidine, sodium bicarbonate, and citric acid on the 13C‐urea breath test (UBT).Methods.  Helicobacter pylori‐infected volunteers received a UBT, 40 mg of famotidine at bedtime, and a second UBT (pudding test meal, 648 mg NaHCO3 tablet then 125 mg of urea in 200 ml of water containing 650 mg of NaHCO3). Experiment 2 consisted of four UBTs. Two were standard citric acid UBTs with 75 mg of urea and 2 g citric acid and two were sequential bicarbonate‐citric acid UBTs. Sequential UBTs consisted of administration of a 648 mg bicarbonate tablet with 50 g of Polycose in 200 ml of water. Five minutes later, 125 mg of 13C‐urea was given in 75 ml of water containing 650 mg of NaHCO3. Breath samples were collected after 15 minutes. Then, to acutely acidify the stomach, 4 g of citric acid was given in 200 ml of water. A second breath sample was collected 15 minutes after the citric acid. The standard UBTs were done before and after 6 days of famotidine (40 mg b.i.d.). Sequential UBTs were done after 1 and 6 days of famotidine therapy. Gastric biopsies for histology, culture, and mucosal cytokines were assessed before and after 6 days of famotidine.Results. Eighteen subjects participated, 10 in each experiment; seven had endoscopy with biopsy. Famotidine/bicarbonate resulted an ∼50% fall in UBT values (p = .021) with 10% becoming negative. The gastric pH increased from 5.1 ± 0.5 to 6.7 ± 0.2 (p = .03) although no pH value predicted the occurrence of false negative results. Under famotidine acid suppression, NaHCO3 reduced the delta over baseline (DOB) by 63% (p = .021). This was reversed with citric acid. Histology showed a H2‐receptor antagonist‐associated increase in the depth of gastric corpus inflammation.Conclusions. H2‐receptor antagonists differ from proton pump inhibitors as high intragastric pH may cause a reduction in urease activity, unrelated to a reduced bacterial load and reversed by citric acid.
Evaluation of Stool Antigen Test, PCR on ORAL Samples and Serology for the Noninvasive Detection of Helicobacter pylori Infection in Children
Authors: Bonamico Margherita , Strappini Pier Michele , Bonci Enea , Ferri Mirella , Crisogianni Massimo , Guido Mirka , Thanasi Enina , Nenna Raffaella , Macchia Stefania , Luzzi Ida , Magliocca Fabio Massimo , Mastromarino Paola 
Published: February 2004

ABSTRACTBackground.  Endoscopy represents the gold standard for the diagnosis of Helicobacter pylori infection. We evaluated three noninvasive tests in a group of children: the immunoassay for detection of H. pylori stool antigen, the polimerase chain reaction for identification of bacterial DNA on the oral cavity and the serum specific antibodies.Materials and Methods.  One hundred and ninety children underwent endoscopy for various gastrointestinal symptoms. H. pylori stool antigen and anti‐H. pylori antibodies were assayed by commercial kits. The bacterial DNA on saliva and oral plaque was detected by a seminested PCR.Results.  Based on the positivity of culture or urease rapid test and histology, infection was detected in 47 patients. The statistical analysis showed that, for the detection of the infection, stool antigen assay is more effective in sensitivity and negative predictive value (91.5% and 96.5%), whereas specificity and positive predictive values appear slightly better in serology (89.6% and 76.0%). Correlations between serum IgG both with patients’ age (r = 0.21, p < .05) and H. pylori stool antigen (r = 0.47, p < .01) were found. The search for bacterial DNA on oral samples proved to be very specific (99.1% on saliva and 98.2% on plaque), but insensitive (22.2% and 25.7%).Conclusions.  In children H. pylori stool antigen represents a sensitive test, suitable for detecting H. pylori infection. Serum IgG proved to be more specific; the PCR on the oral cavity resulted as being a very specific, but insensitive test.
Abnormal Gastroesophageal Flap Valve is Highly Associated with Endoscopic Reflux Esophagitis after Helicobacter pylori Eradication
Authors: Takeuchi Rie , Kato Kimitoshi , Mizuno Shigeaki , Kawamura Yo , Kawamura Fumio , Iwasaki Ariyoshi , Arakawa Yasuyuki 
Published: February 2004

ABSTRACTBackground.  Whether or not eradicating Helicobacter pylori worsens reflux esophagitis remains controversial. We investigated the relationship between gastroesophageal flap valve grading and endoscopic reflux esophagitis (in patients with peptic ulcer and gastritis) before and after H. pylori eradication in a case controlled study. Whether endoscopic assessment of the gastroesophageal flap valve allows prediction of endoscopic reflux esophagitis development or exacerbation was also assessed.Materials and Methods.  A total of 220 patients with peptic ulcer or chronic gastritis, who received H. pylori eradication therapy, were followed for at least 6 months (range, 6–34 months) for endoscopic changes. Another 88 age‐ and disease‐matched H. pylori‐positive controls, without eradication therapy, were also enrolled. Gastroesophageal flap valve grade (I–IV) was assessed using the Hill classification.Results.  Endoscopic reflux esophagitis incidence was significantly (p < .01) higher in abnormal gastroesophageal flap valve (grades III and IV) than in normal gastroesophageal flap valve (grades I and II) cases in both H. pylori eradication and control groups. The rate of new endoscopic reflux esophagitis after eradication was significantly (p < .01) higher in the abnormal than in the normal gastroesophageal flap valve group (54.5% vs. 9.1%). By contrast, the endoscopic reflux esophagitis exacerbation rate in patients with endoscopic reflux esophagitis before eradication was low (4.5%) and endoscopic reflux esophagitis improvement was observed in 40.9% of these patients.Conclusions.  These results suggest gastroesophageal flap valve grading by endoscopy to be useful for predicting the risk of newly developing endoscopic reflux esophagitis after H. pylori eradication, in addition to predicting the presence of endoscopic reflux esophagitis.
Recurrent Peptic Ulcers in Patients Following Successful Helicobacter pylori Eradication: A Multicenter Study of 4940 Patients
Authors: Miwa Hiroto , Sakaki Nobuhiro , Sugano Kentaro , Sekine Hitoshi , Higuchi Kazuhide , Uemura Naomi , Kato Mototsugu , Murakami Kazunari , Kato Chieko , Shiotani Akiko , Ohkusa Toshifumi , Takagi Atsushi , Aoyama Nobuo , Haruma Ken , Okazaki Kazuichi , Kusugami Kazuo , Suzuki Masayuki , Joh Takashi , Azuma Takeshi , Yanaka Akinori , Suzuki Hidekazu , Hashimoto Hiroshi , Kawai Takashi , Sugiyama Toshiro 
Published: February 2004

ABSTRACTObjective.  Although curative treatment of Helicobacter pylori infection markedly reduces the relapse of peptic ulcers, the details of the ulcers that do recur is not well characterized. The aim of this study is to describe the recurrence rate and specific features of peptic ulcers after cure of H. pylori infection.Methods.  This was a multicenter study involving 4940 peptic ulcer patients who were H. pylori negative after successful eradication treatment and were followed for up to 48 months. The annual incidence of ulcer relapse in H. pylori‐cured patients, background of patients with relapsed ulcers, time to relapse, ulcer size, and site of relapsed ulcers were investigated.Results.  Crude peptic ulcer recurrence rate was 3.02% (149/4940). The annual recurrence rates of gastric, duodenal and gastroduodenal ulcer were 2.3%, 1.6%, and 1.6%, respectively. Exclusion of patients who took NSAIDs led annual recurrence rates to 1.9%, 1.5% and 1.3%, respectively. The recurrence rate was significantly higher in gastric ulcer. Recurrence rates of patients who smoked, consumed alcohol, and used NSAIDs were significantly higher in those with gastric ulcer recurrence compared to duodenal ulcer recurrence (e.g. 125 of 149 [83.9%] relapsed ulcers recurred at the same or adjacent sites as the previous ulcers).Conclusions.  Curative treatment of H. pylori infection is useful in preventing ulcer recurrence. Gastric ulcer is more likely to relapse than duodenal ulcer. Recurrent ulcer tended to recur at the site of the original ulcers.
The TETRA Study: A prospective evaluation of Helicobacter pylori‘Test‐and‐Treat’ Strategy on 736 Patients in Clinical Practice
Authors: Gisbert Javier P. , Badía Xavier , Roset Montserrat , Pajares José María 
Published: February 2004

ABSTRACTAims.  To prospectively evaluate the effectiveness of the test‐and‐treat strategy in a large group of dyspeptic patients in clinical practice.Methods.  Patients with ulcer‐like dyspepsia, < 45 years, without alarm symptoms, were prospectively studied. Helicobacter pylori infection was diagnosed with the 13C‐urea‐breath‐test, and eradication or symptomatic treatment was prescribed accordingly. ‘Symptomatic improvement’ was defined as the percentage of patients with a decrease of ≥ 2 levels in the dyspepsia‐severity‐score or with no symptoms after treatment. Health status and use of health resources were also assessed. Endoscopy was performed in therapeutic failures.Results.  Out of 736 patients initially included, 422 received eradication, and 314 symptomatic therapy; 87% returned at 6 weeks and 67% at 6 months. At 6 months, ‘symptomatic improvement’ was achieved in 73% and 54% of the patients, in eradication and symptomatic groups, respectively (p < .001), and overall in 66%. A reduction of 78% in mean self‐assessment visual analogical score was observed at 6 months. More than 50% of patients were ‘much better’ at control visits. Endoscopy (18%) and physician's visits (13%) were the main health resources used. No gastric or oesophageal cancer was diagnosed.Conclusion.  This large prospective study shows that the test‐and‐treat strategy is effective and safe for management of dyspeptic patients in clinical practice.
13C‐Urea Breath Test to Diagnose Helicobacter pylori Infection in Children Aged up to 6 Years
Authors: Machado Rodrigo Strehl , Da Silva Patrício Francy Reis , Kawakami Elisabete 
Published: February 2004

ABSTRACTBackground.  13C‐urea breath test (13C‐UBT) is an accurate noninvasive tool for diagnosis of Helicobacter pylori infection. It is considered the best method for epidemiological studies, but there are few studies to evaluate the 13C‐UBT in infants and toddlers.Aim.  To evaluate the 13C‐UBT performed with infrared spectroscopy in children aged up to 6 years.Patients.  Sixty‐eight patients (6 months. to 5 years 11 months.) were evaluated prospectively and consecutively.Methods.  Helicobacter pylori infection was detected by positive culture, or rapid urease test and histological examination, both positive. 13C‐UBT was performed with 50 mg of 13C‐urea diluted in 100 ml of commercial orange juice. Two expired air samples were collected: before and 30 minutes after tracer ingestion. Cutoff of delta over baseline (DOB) was 4.0‰ and urea hydrolysis rate 10 µg/minute.Results.  Fifteen of 68 (22.1%) patients were H. pylori infected. Sensitivity was 93.3% (95% CI; 86.8%–99.7%) and specificity was 96.2% (95% CI; 93.6%–98.8%), and these values were equal for DOB and urea hydrolysis rate. Negative DOB values in noninfected patients ranged from −1.5‰ to 2.6‰ and positive DOB values ranged from 10.8‰ to 105.5‰. There was no relationship between DOB values and age.Conclusion.  13C‐UBT performed with infrared spectroscopy proved to be a reliable and accurate noninvasive diagnostic tool for H. pylori infection detection in children aged up to 6 years. Results far from cutoff value can clearly distinguish positive from negative 13C‐UBT results in children up to 6 years old.
Helicobacter pylori Associated Antigastric Autoantibodies: Role in Sjögren's Syndrome Gastritis
Authors: Sorrentino Dario , Faller Gerhard , DeVita Salvatore , Avellini Claudio , Labombarda Antonella , Ferraccioli Gianfranco , Kahlow‐Toussaint S. 
Published: February 2004

ABSTRACTBackground.  Previous studies have shown that Helicobacter pylori seroprevalence in Sjögren's syndrome is comparable with that of the general population. However, the origin of the chronic gastropathy associated with this syndrome and the role of local autoimmunity – possibly triggered by bacterial infection – in its pathogenesis remain unclear.Materials and Methods.  We initially determined the prevalence of IgG anti H. pylori in dyspeptic subjects with and without Sjögren's syndrome. In subsets of both groups we then determined anti CagA and human tissue‐tested anticanalicular/antifoveolar autoantibodies. We also compared activity, atrophy and Mucosa Associated Lymphoid Tissue (MALT) scores, as well as symptoms, before and after bacterial eradication.Results.  Prevalence of H. pylori in Sjögren's syndrome patients was similar to controls: 31/54 (57%) vs. 93/150 (62%). Anti CagA prevalence was also similar in the two groups. Twenty weeks after H. pylori eradication, histological activity decreased in both groups, however, atrophy and MALT decreased significantly only in controls. Sixteen months after H. pylori eradication, 75% of Sjögren's syndrome patients still complained of dyspepsia compared with 13% of controls. Finally, antigastric autoantibodies were present in 29% of tested Sjögren's syndrome patients vs. 28% of controls.Conclusions.  H. pylori infection was equally prevalent among dyspeptic Sjögren's syndrome patients and dyspeptic controls. Likewise, there were no differences regarding anti CagA prevalence or antigastric autoantibodies among the two groups. The persistence of symptoms as well as of the lymphocytic infiltration and atrophy after H. pylori eradication in Sjögren's syndrome may underlie the ‘endogenous’ and still unknown nature of the gastropathy in this condition.
Genotypes of the Helicobacter pylori vacA Signal Sequence Differ with Age in Korea
Authors: Lee Jun Haeng , Choe Yon Ho , Jeon Byung Ha , Oh Yoo Joung , Kim Jae J. , Rhee Jong Chul , Kim Pum Soo , Choi Mi Sook 
Published: February 2004

ABSTRACTBackground.  Studies on Helicobacter pylori genotypes have focused on adults in developed countries, and data on the genotypes of Helicobacter pylori recovered from the children are rare.Materials and methods.  One hundred and twenty‐eight biopsy samples from patients with H. pylori infection were studied. The patients’ ages ranged from 9 to 83 years. PCR analysis for vacA genotypes was performed using DNA extracted from biopsy specimens.Results.  Genotyping of the s‐region showed s1a in 33 (25.8%) samples and s1c in 82 (64.1%) samples. When the specimens were grouped by age, the distribution of s‐region genotype was found to be significantly different between groups (p = .002). The prevalence of s1a was 45.2% in patients < 20 years old, but 14.9% in patients ≥ 50 years old. On the other hand, the prevalence of s1c or recombinant s1a‐s1c was higher in those ≥ 50 years old. The distribution of the m‐region did not differ significantly with age (p = .110).Conclusions.  Strain populations infecting Korean adults and children differ.
The Incidence ofHelicobacter pyloriAcquisition in Children of a Canadian First Nations Community and the Potential for Parent‐to‐Child Transmission
Authors: Sinha Samir K. , Martin Bruce , Gold Benjamin D. , Song Qunsheng , Sargent Michael , Bernstein Charles N. 
Published: February 2004

ABSTRACTBackground and Aims. We have previously reported that Wasagamack, a Canadian First Nations community has a seroprevalence rate ofHelicobacter pyloriof 95% and a prevalence rate among children aged 0–12 years as measured by stool antigen testing of 56%. We aimed to determine the rate of infection acquisition and possible modes of transmission of childhoodHelicobacter pyloriinfection in this Canadian First Nations community.Methods. Children who were previously negative forH. pyloriby stool antigen testing in August 1999 were eligible for enrollment in August 2000; 50 (77%) eligible children underwent stool collection.H. pyloristool antigen status was tested using the Premier Platinum HpSA test. Drinking water samples, maternal saliva, breast milk, local berries and flies were tested by three complementaryH. pylori‐specific PCR assays. Soothers or bottle nipples, collected from 16 children whoseH. pyloristool antigen status was determined, were bathed in sterile water and this water was tested by PCR.Results. Stool was positive forH. pyloriin 16% (8/50) of children retested. Five had no other siblings infected and three had infected siblings. The mothers of all children infected were positive forH. pylori. The median age of newly infected children was 6 years (range 1–13 years). By PCR, 78% (18/23) mothers’ saliva samples, 69% (11/16) soother water samples and 9% (1/11) water samples from infected homes tested positive. All of 24 sequenced PCR‐produced DNA fragments from samples showed 99% homology with that from ATCC type strainH. pylori.Conclusions. The rate of childhoodH. pyloriacquisition was 16% over 1 year, and was not dependent on number of siblings infected. The finding of homologousH. pyloriDNA in saliva and in soother water suggests the possibility of human to human transmission, particularly via an oral–oral route. Thus, there is the potential for further investigations in this population and other endemic communities that are directed at prevention of infection transmission via this modality.
The Prevalence and Incidence of Helicobacter pylori Infections Among Young Recruits During Service in the Hungarian Army
Authors: Fürész József , Lakatos Susan , Németh Krisztina , Fritz Péter , Simon László , Kacserka Katalin 
Published: February 2004

ABSTRACTBackground.  A vast number of data indicate that the prevalence of Helicobacter pylori infections is positively correlated with age and is different in various countries. Although our knowledge of transmission of H. pylori is very limited, it is reasonable to assume that it could be much more contagious in closed communities, for example in garrisons, than in normal populations.Methods.  Young male recruits (aged 19–23 years) in the Hungarian Army were tested for seropositivity at the beginning and at the end of their military service.Results.  The prevalence of H. pylori seropositivity was found to be 23% (♦CI95%: 21–24%) among the young male recruits. Seroconversion among the formerly seronegative persons after completing either their 9‐month or 6‐month military service was 30% (CI95%: 25–35%) and 23% (CI95%: 8–45%), respectively. In those groups, where either the H. pylori infection was eradicated by antibiotics or hygienic countermeasures were introduced, the infection rate was reduced from 23% to 11% (CI95%: 3–25%) and to 0% (CI95%: 0–6%); p > .2 and p < .002, respectively.Conclusion.  Our data suggest that, although H. pylori has a very high contagiosity in closed communities, its spread can be reduced or even prevented by medication of the infected persons and/or by improving the hygienic conditions and introducing anti‐infective sanitary regulations.
Serological Responses of FldA and Small‐Molecular‐Weight Proteins of Helicobacter pylori: Correlation with the Presence of the Gastric MALT Tissue
Authors: Yang Hsiao‐Bai , Sheu Bor‐Shyang , Wang Jin‐Town , Lin Shih‐Ting , Wu Jiunn‐Jong 
Published: February 2004

ABSTRACTPurpose.  We tested whether the serological response to Flavodoxin‐A (FldA) protein and anti‐Helicobacter pylori immunoblots correlated to the degree of mucosa‐associated lymphoid tissue (MALT) in the stomach.Methods.  Eighty H. pylori‐infected patients with different degrees of MALT in the stomach were investigated with serum sampling and endoscopy on enrolment, the 2nd and the 12th months after anti‐H. pylori therapy. All sera were tested for the anti‐FldA protein and anti‐H. pylori immunoblots, including 19.5, 26.5, 30, 35, 89, and 116 KDa (CagA). Regression of follicular gastritis was assessed by histology.Results.  Patients with dense lymphoid follicles had higher prevalence rates of anti‐FldA protein, 19.5, 26.5, and 30 KDa antibodies of H. pylori (p < .05). Histologic downgrade of MALT was observed in 25% (10/40) of patients in the 2nd month and in 60% (23/38) in the 12th month after H. pylori therapy. After H. pylori eradication, the patients with MALT and dense lymphoid follicles had significantly negative seroconversions of 19.5, 26.5, 30, and 35 KDa antibodies (p < .05), but not of CagA and FldA.Conclusion.  Patients with gastric MALT and dense lymphoid follicles had different anti‐H. pylori serological responses to those with scanty or an absence of lymphoid follicles. The negative seroconversion of the smaller‐molecular‐weight proteins, but not CagA and FldA, may correlate with the regression of MALT by H. pylori eradication.