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Background: The role of small intestinal bacterial overgrowth (SIBO) in functional digestive disorders in the pediatric population is a matter of controversy, since methods currently used to establish this diagnosis are difficult to interpret. The aim of this work was to analyze the characteristics of the lactulose H(2) breath test (LHBT) in children with functional gastrointestinal symptoms according to more recent criteria., Methods: Seventy-two patients and 17 controls were enrolled. A questionnaire was administered regarding digestive symptoms (abdominal pain, bloating, vomiting, and bowel-movement disorders). A lactose hydrogen breath test was performed to rule out lactose malabsorption and a LHBT was used to measure the time elapsed between lactulose oral ingestion and an increment of H(2) concentration of 20 ppm over basal., Results: There were no differences of age and gender between patients and controls. Mean time to 20-ppm change was shorter in patients (56.3 ± 3 min) compared to healthy children (74.7 ± 5 min), p\0.05. In 39% of patients, rise of H(2) occurred during the first 40 min after lactulose ingestion, and in almost all controls, an increment was observed between 50 and 90 min (p\0.05). Symptoms were unrelated to time to 20-ppm change., Conclusions: An abnormal LHBT was found in children with functional symptoms of the digestive tract, but the exact mechanism involved, accelerated intestinal transit or SIBO, needs to be confirmed by an additional method.

Helicobacter pylori infection is highly prevalent in Chile (73%). Usually a minority of infected patients develops complications such as ulcers and gastric cancer that have been associated with the presence of virulence factors (cagA, vacA) and host T helper response (Th1/Th2). Our aim was to evaluate the relationship between strain virulence and host immune response, using a multiple regression approach for the development of a model based on data collected from H. pylori infected patients in Chile. We analyzed levels of selected cytokines determined by ELISA (interleukin (IL)-12, IL-10, interferon (IFN)-gamma and IL-4) and the presence of cagA and vacA alleles polymorphisms determined by PCR in antral biopsies of 41 patients referred to endoscopy. By multiple regression analysis we established a correlation between bacterial and host factors using clinical outcome (gastritis and duodenal ulcer) as dependent variables. The selected model was described by: clinical outcome=0.867491 (cagA)+0.0131847 (IL-12/IL-10)+0.0103503 (IFN-gamma/IL-4) and it was able to explain over 90% of clinical outcomes observations (R(2)=96.4). This model considers that clinical outcomes are better explained by the interaction of host immune factors and strain virulence as a complex and interdependent mechanism.

Aim: To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers., Methods: Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing., Results: The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India., Conclusion: Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b m1 and s2 m2 recedes H Pylori strain distribution in Spain and Portugal.

Background: Iodine deficiency (even moderate) plays a major role in pregnancy associated goiter development, which is only party reversible after pregnancy. The prevalence of post partum thyroiditis is reported to be slightly lower in areas of iodine deficiency. Thus iodine supplementation may be effective in decreasing pregnancy associated increase in thyroid volume, but enhances the risk of increasing the prevalence of thyroid dysfunction in the post partum period. Therefore, we evaluated the effect of iodine supplementation (with two different doses: 50 microg and 250 microg) on the prevalence of post partum thyroiditis and the decrease in thyroid volume up to 8 months post partum in an area of mild iodine deficiency., Patients and Methods: Thyroid volume of 56 women was evaluated 5 days and 3 months after delivery (study I). In an intervention study (Study II) 70 women were randomized to receive 50 or 250 microg of potassium iodide for a period of 8 months post partum beginning five days after delivery. Thyroid volume, the echogenecity of the thyroid gland, thyroid hormone parameters (T4, T3, fT4, TSH) and thyroid antibodies (TPO and Tg-Ab) were measured 5 days, 3 and 8 months after delivery., Results: A total number of 11 women developed postpartum thyroid dysfunction: 4 women developed manifest thyroid dysfunction (3 hyperthyroidism and 1 hypothyroidism) 3 months post partum. The remaining seven had subclinical hypo- or hyperthyroidism. All changes were clinically mild and transient as evidenced by normalization of thyroid hormone parameters on reexamination at 8 months. Among the eleven, 6 women in the 50 microg iodine group and 5 women of the 250 microg iodine group developed thyroid dysfunction, suggesting that the iodine dose did not affect post partum thyroiditis. The administration of only 50 microg iodine was associated with a significant fall of thyroid size already 3 months after delivery (25.4 +/- 1.5 ml (mean +/- sem) to 18.2 +/- 1.25 p <0.001). The application of 250 microg iodine was equally effective. 8 months post partum a slight but further decrease could be demonstrated. On the other hand, in study I no significant reduction in thyroid volume was observed in women receiving no supplementary iodine (thyroid volume at delivery 29 +/- 2.2 ml; at 3 months 27.5 +/- 3.0 ml., Conclusion: The administration of supplementary iodine (up to 250 microg) to an unselected population, residing in an area of mild iodine deficiency, in the post partum period is save as indicated by a prevalence of 5.7% manifest thyroid dysfunction. These changes are clinically mild and transient. Even the amount of 50 microg of iodine supplementation seems to by very efficient in reducing pregnancy associated increments in thyroid volume.