Helicobacter pylori prevalence in children influenced by non-specific antibiotic treatments.

OBJECTIVE: Helicobacter pylori (H.p.) infections play a very important role in the development of ulcerations and malignancies of the gastrointestinal tract. It is assumed that the primary infection occurs during childhood, depending on numerous environmental factors among them hygiene and social status. Our aim was to determine whether treatment with antibiotics affects the persistence of H.p. infection. METHODS: In 2006, we conducted an epidemiological study among all grade 8 students in the city of Leipzig (mean age 14.6 years). To determine the prevalence of H.p. infection, a voluntary H.p. test (13C-urea breath test) was performed in all participants. RESULTS: The H.p. prevalence was 6.3% (N = 1,598). A significant difference was found between those students who had been treated with an antibiotic at least once prior to the test and those who had never received any antibiotics (4.0% and 11.1%, respectively, p < 0.001). H.p. prevalence decreased with increasing numbers of antibiotic treatments. CONCLUSION: In adolescence, treatment with "non-H.p. specific" antibiotics appears to significantly affect H.p. prevalence. Moreover, the actual persistence of H.p. in "chronic persistent" H.p. infections appears to fluctuate at least in younger years. Thus, any "non-H.p. specific" antibiotic treatment should be considered in the diagnosis and treatment of H.p. infections and should be taken into account as an important confounder in future epidemiological studies.

Influence of sociodemographic factors on Helicobacter pylori prevalence variability among schoolchildren in Leipzig, Germany. A long-term follow-up study.

BACKGROUND: Until the beginning of this decade the assumption was that the Helicobacter pylori prevalence increases with the age of the population under consideration. More and more epidemiological studies have been suggestive of constancy in Helicobacter pylori prevalence, but to date there has been no long-term follow-up study in a large group of children confirming this hypothesis. METHODS: Following up our study of H. pylori among school starters and 2nd graders in 1998 and 2000, we conducted a third phase of this study in 2006 using the [13C]-Urea Breath Test and a detailed parent-completed epidemiological questionnaire to evaluate the development of prevalence among the overall population of 8th graders in the city of Leipzig (n = 1,905), and especially of the subgroup of participants who took part in all three study phases (n = 751). RESULTS: The overall H. pylori prevalence was 6.5% and had not significantly changed since 1998 and 2000 (6.1%, 5.7% respectively). However, we noticed a significant lower prevalence in the subgroup that participated in all study phases (2.7%). Moreover, we observed a dependence of prevalence on distribution of sociodemographic risk factors such as foreign nationality of at least one parent, birth outside of Germany, low parental education and unemployment, and > or = 2 older siblings. CONCLUSION: The variability in prevalence is most likely a result of unequal sociodemographic family backgrounds.

Helicobacter pylori colonisation and eczema.

The hygiene hypothesis postulates that the increase in atopic diseases may in part be due to diminished exposure to microorganisms. But it is unknown which type of infection does render protection. An epidemiological study was conducted in Leipzig, Germany, and its rural county, involving 3347 school starters. Two types of infection were considered: (1) gastrointestinal colonisation (Helicobacter pylori detection using in vivo [(13)C] urea breath test) and (2) respiratory infections (physician-diagnosed lower (bronchitis) and upper (common cold) respiratory infections). H pylori colonisation was selected because it is very common and plays an important role in gastrointestinal disorders. Atopic eczema was selected as the (allergic) target variable because of its high frequency in the age of the study participants. The results, adjusted for relevant confounders, showed a significant inverse association between H pylori infection and eczema (adjusted odds ratio (aOR) = 0.31, p = 0.006) in children not predisposed to atopy. In contrast, bronchitis increased the risk of eczema (aOR = 1.98, p<0.001). Bacterial digestive tract colonisation (infection) seems to protect against eczema in comparison with the effect of respiratory tract infections. The hygiene hypothesis may be better explained when gastrointestinal and respiratory infections are subtly differentiated.

Bio-effect monitoring using a [(15)N]methacetin test as diagnostic tool to monitor remediation effects in an industrially polluted region.

The classical way to demonstrate the efficiency of remediation is measuring the reduction of toxic compounds in the environment. Nevertheless, more important is the risk reduction in human health. To determine changing health effects, exposure and bio-effects have to be monitored at time of and during remediation. Kindergarten children from a heavily polluted industrial (n=23) and a control area (n=12) were investigated. The region-specific outdoor and indoor exposure [27 volatile organic compounds (VOC), emphasis on tri- and tetrachloroethylene (TRI, TETRA)], the internal load [(trichloroacetic acid-TCA-as urine metabolites of TRI and TETRA and S-phenyl- and S-benzylmercapturic acid (SPMA and SBMA) as metabolites of benzene and toluene], and biological effect assessment ([(15)N]methacetin test-a non-invasive stable isotope test to determine the unspecific liver detoxification capacity of an individual) were measured twice a year during 2 years of remediation (1997/1998). It could be shown that in- and outdoor levels of TRI and TETRA decreased by 47% in the heavily polluted village, Greppin, while the levels remained much the same in the control village, Roitzsch. This trend was reflected in the decreasing elimination of TCA in the urine (41%) by the Greppin children, with no differences in the TCA elimination in Roitzsch probands. As the remediation efforts decreased the burden of exposure, the children's liver detoxification capacity improved as well. Combining different methods, such as exposure-effect (external and internal loads) and bio-effect monitoring, proved to be useful to assess remediation successes including the improvement in human health.

Detecting exposure-dependent changes of liver detoxification capacity of children in a formerly high-loaded industrial area with a 15N-labelled diagnostic tool.

The effect of remediation activities in formerly high-loaded industrial areas is measured conventionally in terms of decreased toxic loads. It is more difficult to investigate the effect on physiological parameters of the people living there. A non-invasive 15N-based organ function test, the [15N]methacetin urine test, was adapted to environmental-medical purposes for the detection of small deviations from the norm-range hepatic detoxification capacity. Parallel to the measurement of region-specific external exposure (especially by tri- and tetrachloro ethylene) and of the corresponding internal load (urinary trichloro acetic acid), the hepatic mono oxygenation capacity was determined. The study cohort consisted of 35 kindergarten children who were 3.3+/-0.5 years old at the beginning of the study. They lived in a high-polluted industrial village (n = 23) and in a non-polluted control village close by (n = 12), respectively. Children living in the polluted area were exposed a 2.3 times higher load and showed detoxification capacities 6% lower than the children in the control area. Improvement of the environmental situation led to exposure data decreasing by 70%, which is also reflected in smaller internal load and improved liver detoxification of the children in the polluted area. Then, between loaded and control area the mean hepatic detoxification was no longer significantly different (0.6%). The study shows that chronic low-dose exposure can disturb a hepatic function and that thereafter the capacity is recovered quickly in children. The stable isotope-based test is suited to characterize a health effect of multicomponent exposure by bioeffect monitoring within the framework of screening and testing the remediation efficiency.

Helicobacter pylori determination in non-municipal drinking water and epidemiological findings.

BACKGROUND: Studies conducted in Europe as well as in North and South America have tried to link Helicobacter pylori colonization with the drinking water supply, especially since H. pylori is known to survive quite well in water. METHODS: In 2000, a cohort of 1884 grade-two children from two rural counties surrounding the city of Leipzig, Germany (77.4% of the 1991/1992 birth cohort) were tested for H. pylori colonization using the [13C]urea breath test. A parent-completed questionnaire elicited details on living conditions and lifestyle habits including questions on the children's drinking water from sources other than public water supplies, swimming in natural waters, etc. In a second independent study, samples of well water, taken from 157 private wells still used in the two counties, were being tested for the presence of H. pylori, using polymerase chain reaction (PCR) method to determine relevant target DNA fragments of H. pylori. RESULTS: In county I, 5.7% of the children and in county II 6.6% tested H. pylori-positive. Cluster analyses of the questionnaire data in both counties pointed to 'drinking water from other than municipal sources', as the closest H. pylori-associated cluster variable. The cluster estimations were supported by odds ratio (OR) calculations with an OR=16.4 (95% confidence interval (CI) 3.1,...,88.5) for county I and OR=4.0 (95% CI 1.3,...,12.4) for county II. The PCR analyses showed H. pylori DNA fragments in 10.8% of the wells in county I and 9.2% in county II. The detection limit was set at 10 DNA copies corresponding to 125 bacteria/L, the average infestation of these wells was 931 bacteria/L. CONCLUSION: Despite the fact that the microbiological and epidemiological data do not correspond except that both studies were conducted in the same geographical areas, the independent findings of H. pylori in well water in the same general areas where children do seem to drink water other than from the public water supply suggests that water may be an important source of H. pylori infection.

Large deuterium isotope effects and their use: a historical review.

Isotope effects are differences in the properties of the isotopes of an element resulting in different reaction rates of a corresponding compound, in equilibrium constants and in the spectra. Shortly after the discovery of stable isotopes of hydrogen, oxygen, and carbon, Jacob Bigeleisen formulated a theory of isotope effects and calculated possible maximum values. Large isotope effects of (2)H (deuterium) against (1)H (protium) were seen to possibly influence interpretations of reaction mechanisms if corresponding labelling is used. Much work was invested to ensure the safety of deuterium use in men in spite of the large isotope effect. On the other hand, large deuterium isotope effects gave rise to several practical applications. Examples are the enhancement of the stability of some technical products against oxidative and against hydrolytic degradation (oils, pharmaceuticals) as well as alterations of the detoxification metabolism of pharmaceuticals in vivo.