Gastroesophageal reflux and Helicobacter pylori: a review

A new method to estimate catheter length for esophageal multichannel intraluminal impedance monitoring in children

BACKGROUND

Multichannel intraluminal impedance combined with pH (MII-pH) is the gold standard test for diagnosing gastro-esophageal reflux disease (GERD). It provides an opportunity to study acid and non-acid GOR and temporal association between symptoms and reflux. Accurate catheter placement is essential to prevent erroneous recording of reflux events. The aims of our study were to assess the accuracy of our devised method in predicting the catheter length for MII-pH in children (Great Ormond Street Hospital (GOSH) Table) and to compare the results with Strobel and Monreau methods.

METHODS

Retrospective review of all records of infants and children who underwent MII-pH studies between January to October 2014. Desired catheter position was calculated using Strobel, Monreau and GOSH formulas and compared to X ray position.

KEY RESULTS

One hundred and forty-four children were included; mean age was 5.1 (±4.5) years, 73 males and 71 females. In the whole group, the correlation between desired catheter position and GOSH Table was 0.95, for Strobel was 0.84, and Monreau was 0.85. In the first group (age <3 years), the correlation was: GOSH Table 0.91, Strobel 0.56, and Monreau 0.6; in the second group (3-10 years): GOSH Table 0.78, Strobel 0.82, and Monreau 0.82; the third group (>10 years): GOSH 0.81, Strobel 0.43, and Monreau 0.43.

CONCLUSIONS & INFERENCES

GOSH Table is an accurate method to estimate the insertion length of MII-pH catheters from nares to a point of approximately two vertebral bodies above the diaphragm in children. Although radiography is required to confirm final catheter position, using GOSH Table will reduce the need for repeated catheter manipulation after initial insertion and will reduce the use of a mathematically complicated formulae.

Hygiene could affect GERD prevalence independently: a population-based study in Tehran

OBJECTIVE

Population-based data on gastroesophageal reflux disease (GERD) in Iran are limited. Current study is going to determine the prevalence of GERD in Tehran, Iran, and its association with potential risk factors.

METHODS

In this cross-sectional study, a random clustered sample of Tehran province permanent households was selected from the latest postcodes. Data were collected by direct interview for each person aged 18-65 yr. GERD was defined as the existence of at least weekly episodes of heartburn and/or acid regurgitation during the last 6 months. All participants were asked about past and recent sanitary conditions, oral hygiene, and smoking. Odds ratios and 95% confidence intervals (CI) were calculated using multivariable analysis.

RESULTS

Interview was performed with 2,561 eligible subjects (42.3% men). Response rate was 84.8%. The prevalence of GERD was 21.2% (95% CI 18.7-23.7). According to multivariable logistic regression analyses, individuals whose drinking water was obtained from well or tank during childhood were more prone to experience GERD symptoms (OR 1.54, 95% CI 1.03-1.77 and OR 2.46, 95% CI 1.53-3.96, respectively). We also detected significant associations with increasing number of missing teeth (P value for linear trend = 0.02) and history of unpurified water consumption during past 10 yr (P < 0.001). Current smokers had a higher prevalence of reflux (OR 1.82, 95% CI 1.32-2.51).

CONCLUSION

The prevalence of GERD in our Iranian population was considerably higher than that reported from other Asian studies approaching western figures. GERD prevalence was significantly associated with the history of unpurified water consumption, poor sanitary conditions of childhood, number of missing teeth, and smoking in this population.

Influence of H. pylori on cyclinD1 and PCNA mRNA expression in HepG2 cell line

AIM: To observe the effects of Helicobacter pylori (H. pylori) on cyclinD1 and PCNA mRNA expression in a human hepatoma cell line HepG2.

METHODS: H. pylori was co-cultured with HepG2 for 1, 3,6, 12 and 24 h. The cyclinD1 and PCNA mRNA expression was detected by semi-quantitative RT-PCR.

RESULTS: When HepG2 cells were cocultured with H. pylori CagA⁺ strain, the amount of cyclinD1 mRNA was increased 4.0-fold by 3 h and PCNA mRNA was increased 2.0-fold by 6 h, compared with that of uninfected control. Neither cyclinD1 mRNA nor PCNA mRNA of the HepG2 cells was increased after incubation with H. pylori CagA^- strain.

CONCLUSION: H. pylori can induce increasing expression of cyclinD1 and PCNA mRNA in HepG2, which may play some roles in the development of hepatocellular carcinoma.

Expression of Helicobacter pylori Hsp60 protein and its immunogenicity

AIM: To express Hsp60 protein of H pylori by a constructed vector and to evaluate its immunogenicity.

METHODS: Hsp60 DNA was amplified by PCR and inserted into the prokaryotie expression vector pET-22b (+), which was transformed into BL21 (DE3) E.coli strain to express recombinant protein. Immunogenicity of expressed Hsp60 protein was evaluated with animal experiments.

RESULTS: DNA sequence analysis showed Hsp60 DNA was the same as GenBank’s research. Hsp60 recombinant protein accounted for 27.2% of the total bacterial protein, and could be recognized by the serum from H pylori infected patients and Balb/c mice immunized with Hsp60 itself.

CONCLUSION: Hsp60 recombinant protein might become a potential vaccine for controlling and treating H pylori infection.

Polymorphism of flagellin A gene in Helicobacter pylori

AIM: To study the polymorphism of flagellin A genotype and its significance in Helicobacter pylori (H. pylori).

METHODS: As the template, genome DNA was purified from six clinical isolates of H. pylori from outpatients, and the corresponding flagellin A fragments were amplified by polymerase chain reaction. All these products were sequenced. These sequences were compared with each other, and analyzed by software of FASTA program.

RESULTS: Specific PCR products were amplified from all of these H. pylori isolates and no length divergence was found among them. Compared with each other, the highest ungapped identity is 99.10%, while the lowest is 94.65%. Using FASTA program, the alignments between query and library sequences derived from different H. pylori strains were higher than 90%.

CONCLUSION: The nucleotide sequence of flagellin A in H. pylori is highly conservative with incident divergence. This information may be useful for gene diagnosis and further study on flagellar antigen phenotype.