Inter- and intra-rater reproducibility of automated and integrated pressure-flow analysis of esophageal pressure-impedance recordings.

BACKGROUND: Automated impedance manometry pressure-flow analysis (AIM analysis) determines pressure measurements relative to bolus flow and has to date shown subtle variations in esophageal motility in relation to dysphagia. In this study, we assessed intra- and inter-rater reproducibility of AIM metrics derived using purpose designed software. METHODS: Fifty patients referred for evaluation of gastro-esophageal reflux symptoms (33 men, age 52 ± 1.9 years) underwent combined high-resolution impedance manometry and completed a dysphagia questionnaire. From 10 liquid and 10 viscous swallows, a subset of four swallows (two saline and two viscous) was systematically selected from each patient for manual and AIMplot analysis, which was performed twice by five observers (two experts, three non-experts). Intra- and inter-rater agreement were determined using intraclass correlation coefficients. KEY RESULTS: AIMplot-based analysis showed high intra-rater and inter-rater reproducibility for all metrics (mean ICCs of 0.95 and 0.94, respectively). Reproducibility of metrics derived for liquid and viscous did not differ (ICCs of 0.96 and 0.91 for liquid and viscous, respectively). In addition, metrics derived by experts had an equivalent level of reproducibility compared to non-experts (ICCs of 0.96 and 0.94, respectively). Variables that could be derived with commercial software (ManoView™) correlated highly with variables from AIMplot-based analysis, such as 4-s integrated relaxation pressure (r = 0.85) and the 20-mmHg isobaric contour defect (r = 0.92). CONCLUSIONS & INFERENCES: Esophageal AIM analysis is highly reproducible, independent of an observer's level of experience in esophageal motility. Therefore, AIM analysis produces data that are reliable for clinical and research purposes.

Seroprevalence of IgG antibodies against 13 vaccine Streptococcus pneumoniae serotypes in the Netherlands.

In this study the seroprevalence of IgG antibodies against 13 vaccine serotypes of the pneumococcus was assessed in the Netherlands. Sera from 7904 persons obtained in a cross-sectional population-based study were analysed. The 13 serotype specific IgG concentrations were assessed simultaneously using a fluorescent bead-based multiplex immuno assay (MIA). Overall, the geometric mean IgG concentrations (GMCs) against the 13 serotypes in unvaccinated individuals increased with age up to 5 years and remained at a plateau thereafter. The data also show that individuals develop antibodies against an increasing number of different serotypes with increasing age. The highest GMCs were found for antibodies directed against serotype 14 and 19F, whereas antibodies against serotypes 4 and 5 had the lowest GMCs. There was no uniform relationship between the occurrence of serotypes causing invasive pneumococcal disease (IPD) and the GMCs against these serotypes. Increased IPD incidence in the elderly did not seem to be the result of a decline in the concentration of IgG antibodies.

Identification of Borrelia burgdorferi sensu lato, Anaplasma and Ehrlichia species, and spotted fever group Rickettsiae in ticks from Southeastern Europe.

Prevalence data for tick-borne pathogens are used to assess the risk for human health. In this study the presence and identity of Borrelia burgdorferi sensu lato, Ehrlichia, Anaplasma, and Rickettsia species in Bulgarian Ixodes ricinus ticks and in non- Ixodes ticks from Turkey and Albania was determined by polymerase chain reaction (PCR) and reverse line blot hybridization. In the adult Bulgarian ticks, the prevalence of Borrelia burgdorferi sensu lato infection was approximately 40%, while Borrelia afzelii was the predominant species, representing more than half of all Borrelia-positive ticks. Ehrlichia and Anaplasma species were detected in 35% of the adult Ixodes ricinus ticks and in 10% of the nymphs. Sequence analysis of PCR products reacting with the Anaplasma phagocytophila probe revealed a 16S rRNA gene identical to that of the Anaplasma phagocytophila prototype strain. Ehrlichia and Anaplasma species were found in approximately 7% of the non- Ixodes ticks. Sequence analysis of some of these samples revealed the presence of Anaplasma ovis, Ehrlichia canis, and a species closely resembling Ehrlichia chaffeensis. About half of all adult ticks examined and approximately 20% of all nymphs were infected with Rickettsia species. In Ixodes ricinus ticks, Rickettsia helvetica and a Rickettsia species designated as IRS3 were found in high prevalence. Rickettsia conorii was found in virtually all non- Ixodes tick species from Albania and Turkey. The results of this study show that many tick-borne diseases are most probably endemic in the Balkan area. Furthermore, the results suggest that there is a considerable chance for simultaneous transmission of tick-borne pathogens to human beings.

The nuclease specificity of the bacteriophage phi X174 A* protein.

The A* protein of bacteriophage phi X174 is a single-stranded DNA specific nuclease. It can cleave phi X viral ss DNA in many different places. The position of these sites have been determined within the known phi X174 nucleotide sequence (1). From the sequences at these sites it is clear that the A* protein recognizes and cleaves at sites that show only partial homology with the origin of RF DNA replication in the phi X DNA. Different parts of the origin sequence can be deduced that function as a signal for recognition and cleavage by the A* protein. We conclude that different parts within the DNA recognition domain of the A* protein are functional in the recognition of the origin sequence in single-stranded DNA. The existence of different DNA recognition domains in the A* protein, and therefore also in the A protein, leads to a model that can explain how the A protein performs its multiple function in the phi X174 DNA replication process (2).