METHODS:Twenty healthy volunteers (10 female, 10 male) underwent the 13 C-MBT after intake of 75 mg 13 C-methacetin p.o. on three occasions. Short-and medium-term reproducibility was assessed with paired examinations taken at an interval of 2 and 18 d (medians), respectively. RESULTS:The reproducibility of the 1-h cumulative 13 C recovery (AUC0-60), characterized by a coefficient of variation of 10%, appeared to be considerably better than the reproducibility of the maximum momentary 13 C recovery or the time of reaching it. Remarkably, as opposed to the short gap between consecutive examinations, the capacity of the liver to handle 13 C-methacetin increased slightly but statistically significantly when a repeat dose was administered after two to three weeks.Regarding the AUC0-60, the magnitude of this fixed bias amounted to 7.5%. Neither the time gap between the repeat examinations nor the gender of the subjects affected the 13 C-MBT reproducibility. CONCLUSION:13 C-MBT is most reproducibly quantified by the cumulative 13 C recovery, but the exactitude thereof may be modestly affected by persistent stimulation of CYP1A2 on repeat examinations.

The feasibility of some electrogastrographic parameters to convey clinically useful information may be hampered by their fair reproducibility. Recoding of parameters of the cutaneous electrogastrogram from primary continuous to secondary categorical may help achieve a better agreement between repeat examinations.

StreszczenieWstęp: Ostatnie duże badania dotyczące częstości zakażeń Helicobacter pylori (H. pylori) u dzieci w Polsce były prowadzone prawie 10 lat temu. Poprawa średnich przychodów i warunków życia w ciągu ostatnich lat pozwala przypuszczać, że odsetek za każeń H. pylori u dzieci powinien wykazywać stały trend spadkowy. Cel: Ocena aktualnej częstości występowania zakażenia H. pylori w populacji ogólnej dzieci szkolnych niemających objawów, zamieszkałych na terenach miejskich Górnego Śląska. Ocena wpływu wybranych czynników środowisko-wych na częstość zakażeń H. pylori oraz wpływ samego zakażenia na parametry antropometryczne badanych dzieci. Materiał i metody: Zbadano 415 dzieci w wieku 7-15 lat (śred-nia 10,8 roku). Wykonano u nich badanie w kierunku zakaże-nia H. pylori metodą mocznikowego testu oddechowego. Wyliczono parametry antropometryczne badanych dzieci oraz przeanalizowano ich warunki mieszkaniowe i środowiskowe. Wyniki: Zakażenie H. pylori wykazano u 15,7% badanej grupy. Nie stwierdzono różnic w średnim wieku dzieci zakażonych i niezakażonych (10,88 ±2,33 vs 10,74 ±2,34, p > 0,05). Status zakażenia H. pylori nie miał żadnego wpływu na wzrost, masę ciała, BMI oraz wskaźnik Cole'a badanych dzieci. Dzieci zakażone H. pylori miały znacznie gorsze warunki mieszkaniowe. Średnia liczba izb w miejscach zamieszkania dzieci zakażonych H. pylori była dużo mniejsza niż w miejscach zamieszkania dzieci niezakażonych (2,78 ±1,21 vs 3,41 ±1,26; p = 0,00038). Zagęszcze-nie, definiowane jako liczba domowników na izbę mieszkalną, było znacznie wyższe w grupie dzieci zakażonych H. pylori (1,92 ±1,18 vs 1,37 ±0,54, p = 0,00079). Wnioski: Obecnie częstość zakażeń H. pylori u dzieci bez objawów w populacji ogólnej w Polsce jest prawdopodobnie znacząco niższa niż podawana w dotychczasowych publikacjach. Złe warunki mieszkaniowe są ważnym czynnikiem ryzyka zakażenia H. pylori u dzieci. AbstractIntroduction: Previous large studies on the prevalence of Helicobacter pylori (H. pylori) infection in children in Poland were carried out about ten years ago. Since then an improvement in mean incomes and living conditions allows one to anticipate that the percentage of H. pylori infected children should be decreasing. Aim: To assess the current prevalence of H. pylori infection among asymptomatic school children from the general population living in the urban area of Upper Silesia (Poland); to assess the impact of environmental factors on the prevalence of H. pylori infection, as well as of the influence of the infection on the anthropometric parameters of children. Material and methods: 415 children aged 7-15 years (mean: 10.8 years) were examined. Their H. pylori status was diagnosed with the 13 C urea breath test. Anthropometric parameters of the children were recorded, and their living conditions and environmental factors were analysed. Results: Helicobacter pylori infection was diagnosed in 15.7% of children. There was no difference in the mean age of the infected and the non-infected children (10.88 ±2.33 vs. 10.74 ±2.34, p >...

The goal of the study was to establish if the conductive area size of recording electrodes affects the quality of a multichannel electrogastrogram. In twelve volunteers (9F, 3M, median age 24 years, range 22-28) on three separate days fasted and postprandial four-channel electrogastrograms were registered in randomized order with Red Dot class Ag/AgCl electrodes of a type: '2222' (conductive area/total area: 2.00/ 10.24 cm 2 , '2271' 2.54/29.64 cm 2 , or '2660' 11.64/11.64 cm 2 (total surface conductive!), and subsequently analyzed with a dedicated software. In the case of type 2271 and 2660 the between-electrode electrical conductivity improved at the end of the recording relative to the basal measurement, whereas type 2222 yielded a stable between-electrode electrical conductivity throughout the examination. Despite the differences in either the conductive area size or its construction, the analysis of variance on parameters describing quantitatively the multichannel electrogastrogram did not reveal a superiority of any from among the electrodes tested. Type 2271 was, however, rated the less handy among the three electrodes. Multichannel surface electrogastrography seems to be technically feasible with any type of high quality electrodes, therefore small dimensions and easy handling may favor the choice of a particular type for this examination.

The low-cost modification of the breath test involving a lower dose of 13C-octanoic acid and NDIRS, renders good short- and medium-term reproducibility, as well as sensitivity of the measurement of gastric emptying of solids.

Recent investigations in humans point out to a disturbing effect of auditory stimuli on the functional integrity of the brain-gut axis. The study was devoted to a systematic comparative evaluation of the effect of noises of different frequency spectra on the postprandial electrical and transport functions of the digestive tract in humans. Twenty six healthy subjects attended a cross-over study, which aimed at comparison of the effect of pink contrasted to blue noise within a given category (band or tonal) and a meal stimulus type (semi-liquid or solid test meal). A panel of noninvasive measurement methods was applied: heart rate variability (HRV) analysis, surface electrogastrography, 13 CO2 breath tests for gastric emptying (GE), lactulose hydrogen breath test for orocecal transit time (OCTT). The blue tonal noise was rated the most annoying one, whereas solely the pink noises exerted discernible cardiovascular effects. No one of the four noises was capable of overriding the meal-induced preponderance of the sympathetic tone. The postprandial gastric myoelectrical activity and the GE of either the semiliquid or the solid test meal appeared to be 'resistant' to the noise exposure, irrespective of the noise type. Similar was the finding in the case of the OCTT, with the exception of a statistically significant retardation of the OCTT with the blue band noise. Ingestion of mixed caloric meals seems to elicit a protective influence against noise-elicited derangements of the functional integrity of the digestive tract proven formerly to occur during the fasting period.

The obtained proof of technical feasibility of a breath test with the use of naturally (13)C-enriched starch and NDIRS provides background for future research on the clinical usefulness of this method for a non-invasive assessment of the pancreatic exocrine function.

In a study aimed to test the effect of body position on the parameters derived from surface electrogastrograms, 17 healthy volunteers (2M, 15F; median age 22.5 years) attended in random order two examination sessions held on separate days. A 30-min recording of the interdigestive gastric myoelectrical activity (GMA) was followed by a 90-min postprandial recording after intake of a 394 kcal mixed solid-liquid test meal. For the first examination the subject was examined in a recumbent position, whereas for the second examination a sitting position was maintained. The dominant frequency and relative time occupied by normogastria was negligibly affected by the posture of the subject during GMA recording. However, a decrease in the dominant power (DP) of the gastric slow waves was observed during both the interdigestive and the postprandial recording period in a sitting position compared to a recumbent position. Consequently, the fed to fasted state DP ratio remained unaffected by body posture during GMA recording. The results indicate that by carefully observing procedural guidelines, good quality electrogastrograms can be obtained with a sitting subject, enabling the provision of comparable parameters to those achieved from standard examination in a recumbent position.