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Background: Helicobacter pylori infection is generally acquired in childhood. Algeria is a country with a high prevalence of H. pylori infection. The aim of this work was to take stock of H. pylori infection in Algerian children.
Materials and Methods: About 31antral biopsies were cultured, and then antibiotic susceptibility testing was performed. The statuses of cagPAI and vacA s, m, I, and d regions were determined as well as geographical typing was done by MultiLocus Sequence Typing (MLST) method.
Results: Culture was H. pylori positive in 12 children. Only one resistance to clarithromycin and one to metronidazole were detected. Four out of six strains possessed cagPAI, and five out of six strains were identified as vacA s2m2i2d2. The five strains tested by MLST were of the hpEurope type.
Conclusion: This study revealed high prevalence of H. pylori infection and low resistance to antibiotics and reported for the first time in Algeria a genetic typing of H. pylori strains isolated from Pediatrics.

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Backgrounds: Helicobacter pylori infections vary in severity and virulence in different populations for various reasons. There are different H. pylori strains with varying degrees of virulence. The genetic diversity of H. pylori strains in gastritis patients in different areas has not been well understood. This study aimed to evaluate the prevalence rate and different genotypes of H. pylori strains in clinical specimens of patients with gastritis in Ilam, Iran.
Materials & Methods: Saliva and gastric biopsy samples were collected from 81 patients (55 males and 26 females in the age range of 20 to 90 years) referring to Ilam medical centers. After DNA extraction, the prevalence of H. pylori as well as vacA, cagA, and ureC genes was evaluated using PCR, and then each vacA-positive sample was further evaluated for m1m2 and s1s2 variants.
Findings: The cagA and vacA genes were found in 27 (71%) and 36 (94.7%) H. pylori-positive samples, respectively. The cagA gene was detected in patients with gastric pain (44.4%) and anorexia (18.51%). Also, the results showed that the vacA s2m2 genotype and m2 allele were present in 32.9% of H. pylori isolates. Moreover, s2m2 and s1m2 genotypes were detected in 42.1 and 26.3% of vacA-positive samples, respectively. The lowest frequency was related to the m1 allele (17.18%).
Conclusion: This study results indicate a plausible relationship between the presence of some genotypes of H. pylori and the progression of gastritis, suggesting these markers as promising biomarkers to predict the disease severity.

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Objective: Helicobacter pylori is a major etiological agent in gastro-duodenal disorders, and has spread in the world. The prevalence of infection with H. pylori is more than 80% in some populations, but only 10% to 20% of them are infected with this organism. Also infection with this pathogen is associated with peptic ulcer disease (PUD), Gastritis (G), Duodenitis (Du), and non-ulcer dyspepsia (NUD). The development of diseases depends on the virulence of the infecting H. pylori strain and the susceptibility of the host. The vacuolating cytotoxin and the cytotoxin associated protein, encoded by vacA and cagA genes are important virulence determinants of H. pylori which are divided into different pathogenic types, to cause varities of infections. This may be used as a marker of infection and could be used to distinguish between pathogenic and nonpathogenic strains of H. pylori in Iran. The aim of this study was to assess the prevalence of vacA genotype of H. pylori and its development of PUD, G, Du, and NUD from Iranian patients who were admitted to Hazrat Rasoul Akram (peace upon him) as an educational and research society, affiliated to Iran University of Medical Sciences and Health Services (IUMS) in Tehran, Iran. Materials and Methods: During this study specimen biopsies were collected from 180 patients who underwent routine gastrointestinal endoscopies to the internal medicine ward, Hazrat Rasoul Akram Hospital, IUMS, Tehran, Iran. Positive H. pylori strains were identified by cultured isolates, standard biochemical methods, and molecular typing was performed by PCR technique to detect vacA gene and its alleles. Result: In this study out of 180 samples of 92 H. pylori strains were isolated and identified by

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High temperature creep in nickel-based superalloys is investigated by discrete dislocation plasticity (DDP). A two-dimensional unite cell model representing micro-structure of superalloy and comprising γ^' particles in γ matrix phase is considered under uniaxial constant stress loading. While plastic deformation of γ phase occurs by a combination of dislocation glide and dislocation climb coupled to the diffusion of vacancies, elastic γ^' particles undergo deformation due to the stress-driven interfacial diffusion at the γ/γ^' interfaces in addition to bulk elastic deformation. It is noted that diffusion of vacancies is explicitly considered where local concentration of vacancies determines climb of dislocations. This model predicts the onset of tertiary creep in superalloys as extensively observed in experiments for commercially important nickel-based superalloys at moderate stress and temperature levels. Possible associated mechanisms are accordingly discussed. Moreover, effects of parameters such as volume fraction of γ^' particles are studied and discussed. Superalloys with three values for volume fraction of γ^' particles are investigated and obtained results indicate that the volume fraction of γ^' particles plays an important role in the creep behaviour of superalloys. Results of this study can be used in a continuum constitutive rule to investigate structural components under operational conditions.