A novel PCR detection assay that amplifies the Helicobacter pylori-specific vacuolating cytotoxin gene (vacA) and thus enables rapid diagnosis of infection is described. Additionally, a real-time probe hybridization melting point analysis assay to detect all three mutations in the 23S rRNA gene associated with clarithromycin resistance was applied directly to antral gastric biopsy samples. Comparison with culture and an alternative PCR assay targeting the 16S rrn gene showed that the vacA assay was sensitive and specific when tested on biopsy samples from 121 patients. Clarithromycin susceptibilities could be determined in the majority (92.3%) of culture-positive gastric biopsy samples analyzed, four of which generated melting peaks indicative of clarithromycin resistance by either an A3G or A3C mutation. The presence of the mutations correlated with the clarithromycin disk diffusion sensitivities of matched cultures. This PCR-based system was simple to perform and could be completed in 3 to 4 h, thereby overcoming the delays associated with conventional culture methods for H. pylori identification and susceptibility testing.Helicobacter pylori, a major cause of chronic gastritis, is strongly associated with the development of gastric and duodenal ulcers and has been linked with gastric adenocarcinoma and B-cell mucosa-associated lymphoid tissue lymphoma (15,17,18). Infection can be eradicated in up to 90% of patients using current combination triple therapies, of which the macrolide antibiotic clarithromycin is a key component (5). Rates of resistance to clarithromycin of 1 to 9% have been reported in several European countries and the United States, with even higher rates in some countries, such as France and Belgium (24). The development of clarithromycin resistance in H. pylori is recognized as a significant contributing factor in treatment failure (8,14), and the mechanism is attributed to single point mutations in the peptidyltransferase region of the 23S rRNA gene (25). Adenine residues at either position 2143 or 2144 can mutate. Transition to guanine (A2143G and A2144G) is the most common mutation type, with the transversion mutation to cytosine (A2143C) less common (16,21,22,25). Although culture of gastric biopsy samples allows further H. pylori strain analysis, including determination of antibiotic susceptibility, tests can take up to 2 weeks to complete. The aim of the present study was to develop a PCR-based system using conventional and real-time techniques enabling same-day diagnosis of H. pylori infection and determination of clarithromycin resistance. MATERIALS AND METHODSGastric biopsy samples and strain isolation. Two sets of gastric biopsy samples were used in this study. First, we examined a series of preserved (Ϫ20°C) gastric biopsy samples from 39 dyspeptic patients attending an open-access endoscopy clinic in Chelmsford during 1995 and 1996. These biopsy samples were confirmed positive for H. pylori by both culture and histology, and the patients were also confirmed seropositive for H. py...

Stool antigen-testing allows non-invasive detection of Helicobacter pylori that is indicative of active infection. Three commercial kits are currently marketed in the UK for stool antigen-testing. The aim of this study was to conduct a comparative evaluation of the performances of each of these tests, compared with culture and histological examination of gastric biopsies, for pre-treatment diagnosis of infection in an adult dyspeptic population in south-east England. Examination of 112 stool samples by the Premier Platinum HpSA ELISA (Meridian Diagnostics) and by the Amplified IDEIA HpStAR ELISA (DakoCytomation) kits demonstrated that the latter was more sensitive (81 . 3 versus 93 . 8 %, respectively) and specific (91 . 7 versus 100 . 0 %, respectively). Additionally, the IDEIA HpStAR was easier to interpret, with OD readings of positive and negative results being far from the recommended cut-off, whereas equivocal results that were generated by the HpSA kit were difficult to interpret. Additional testing of 87 of the 112 stools by the ImmunoCard STAT! HpSA kit (Meridian Diagnostics) demonstrated that this test was easier to perform than ELISA and was more sensitive than the HpSA kit but, compared with the IDEIA HpStAR kit, the ImmunoCard test was less sensitive (87 . 8 versus 95 . 9 %, respectively) and specific (89 . 4 versus 100 . 0 %, respectively). Furthermore, the ImmunoCard test generated weakly positive results, correlating with lower OD readings for both ELISA kits, that were difficult to interpret. The Amplified IDEIA HpStAR kit is therefore the most sensitive and specific of the three tests that are available for pre-treatment, non-invasive detection of H. pylori in stool samples in an English adult dyspeptic population.

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Background: Pathophysiology of rumination syndrome (RS) is not well understood. Treatment with diaphragmatic breathing improves rumination syndrome. The aim of the study was to characterize vagal tone in patients with rumination syndrome during and after meals and during diaphragmatic breathing. Methods: We prospectively recruited 10 healthy volunteers (HV) and 10 patients with RS. Subjects underwent measurement of vagal tone using heart rate variability. Vagal tone was measured during baseline, test meal and intervention (diaphragmatic (DiaB), slow deep (SlowDB), and normal breathing). Vagal tone was assessed using mean values of root mean square of successive differences (RMSSD), and area under curves (AUC) were calculated for each period. We compared baseline RMSSD, the AUC and meal-induced discomfort scores between HV and RS. Furthermore, we assessed the effect of respiratory exercises on symptom scores, and number of rumination episodes. Key Results: There was no significant difference in baseline vagal tone between HV and RS. During the postprandial period, there was a trend to higher vagal tone in RS, but not significantly (P > .2 for all). RS had the higher total symptom scores than HV (P < .011). In RS, only DiaB decreased the number of rumination episodes during the intervention period (P = .028), while both DiaB and SlowDB increased vagal tone (P < .05 for both). The symptom scores with the 3 breathing exercises showed very similar trends. Conclusions and inferences: Patients with RS do not have decreased vagal tone related to meals. DiaB reduced number of rumination events by a mechanism not related to changes in vagal tone. K E Y W O R D S autonomic nervous system, breathing exercises, gastro-esophageal reflux disease, gastrointestinal diseases, rumination syndrome How to cite this article: Hoshikawa Y, Fitzke H, Sweis R, et al. Rumination syndrome: Assessment of vagal tone during and after meals and during diaphragmatic breathing.