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ABSTRACT: Helicobacter pylori infection is often acquired in childhood and can persist for life. Previous studies in adult patients have shown that H. pylori isolates from North American and European hosts express predominantly type 2 Lewis x (Le(x)) and Le(y) epitopes, while Asian strains have the capacity to express type 1 Le(a) and Le(b) structures. In order to understand the influence of environmental and host factors on the expression of Le antigens, we analysed 50 Greek H. pylori isolates from symptomatic children. Both CagA-positive and -negative strains were evaluated. The expression of Le antigens was determined by whole-cell indirect ELISA (WCE), and LPS profiles were assessed by gel electrophoresis and immunoblotting. Occurrence of Le(x) and/or Le(y) antigens was confirmed in 35 of the isolates (70 %) while 15 of the isolates were non-typable. It was found that 11 of the paediatric isolates had the propensity to express type 1 Le(b) blood-group antigen (22 %), a feature relatively uncommon in H. pylori isolates from adults. One strain expressed both Le(b) and Le(a) antigens. The majority of the isolates (49/50, 98 %) expressed α1,6-glucan, an antigenic non-Le determinant present in the outer core region of H. pylori LPS. All Le(x)- and Le(y)-expressing strains also carried a functional cag pathogenicity island-encoding a type IV secretion system, capable of translocating CagA protein, as well as the vacAs1 allele, suggesting that Le(x) and Le(y) epitopes may aid the persistence of more aggressive strains. No association between bacterial virulence characteristics and the histopathological observations was evident.
Journal of Medical Microbiology 12/2011; 61(Pt 4):559-66. · 2.50 Impact Factor
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ABSTRACT: To examine the impact of oral glutamine (Gln) supplementation on gut integrity and on the incidence of necrotizing enterocolitis (NEC)/septicemia of premature neonates.
Preterm neonates (n = 101, gestational age <34 weeks, birth weight <2000 g) were randomly allocated to receive from day 3 to day 30 postpartum, either oral Gln (0.3 g/kg/day, n = 51-Gln group) or placebo (caloreen-isocaloric, n = 50-control group). Intestinal permeability was determined from the urinary lactulose/mannitol recovery (L/M ratio) following their oral administration and assessed at three time points: day 2 (before first administration), day 7 and day 30 of life. The incidence of NEC and septicemia over the study period was also recorded.
A decrease of lactulose recovery at days 7 (p = 0.001) and 30 (p < 0.001) and a decrease of L/M ratio at day 7 (p = 0.002) were observed only in the Gln group. Lactulose recovery and L/M ratio at day 7 (p = 0.022 and p = 0.004, respectively), as well as lactulose recovery (p = 0.001), mannitol recovery (p = 0.042), and L/M ratio (p = 0.001) at day 30, were decreased in the Gln group as compared to controls. NEC and septicemia were lower in the Gln group at the end of the first week (p = 0.009 and p = 0.041, respectively) and up to the end of the study (p < 0.001 and p = 0.048, respectively).
Oral Gln administration may have beneficial effects on intestinal integrity and the overall incidence of NEC/septicemia in preterm infants.
The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 04/2011; 24(10):1294-300. · 1.36 Impact Factor
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ABSTRACT: The aims of this study were to evaluate the implication of food allergy as a cause of paediatric constipation and to determine the diet period needed to tolerate the constipation-causing foods. Fifty-four children aged 6 months to 14 years (median, 42 months) suffering from chronic constipation (without anatomic abnormalities, cοeliac disease or hypothyroidism), unresponsive to a 3-month laxative therapy, were prospectively evaluated. All participants were evaluated for allergy to cow's milk, egg, wheat, rice, corn, potato, chicken, beef and soy, using skin tests (SPT), serum specific IgE and atopy patch test (APT). A withdrawal of the APT-positive foods was instructed. Thirty-two children had positive APT; 15 were positive to one; six, to two and 11, to three or more food allergens, wheat and egg being the commonest. After withdrawing the APT-positive foods for an 8-week period, constipation had improved in 28/32 children, but a relapse of constipation was noticed after an oral food challenge, so they continued the elimination diet. Tolerance to food allergens was achieved in only 6/28 after 6 months, compared to 25/28 after 12 months and to all after a 2-year-long elimination. Food allergy seems to be a significant etiologic factor for chronic constipation not responding to treatment, in infants and young children. APT was found to be useful in evaluating non-IgE allergy-mediated constipation, and there was no correlation of APT with IgE detection. Tolerance was adequately achieved after 12 months of strict food allergen elimination.
European Journal of Pediatrics 02/2011; 170(9):1173-8. · 1.88 Impact Factor
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ABSTRACT: Rapid urease test (CLO-test) is an inexpensive and quick method for diagnosis of Helicobacter pylori infection with controversial results in children. We evaluated the performance of CLO-test in relation to endoscopic and histological findings in children with H. pylori infection.
We studied the medical records of children with H. pylori infection who were diagnosed between 1989 and 2009. Noninfected children were used as controls. H. pylori infection was defined by positive culture or by two other positive tests (histology and CLO-test, or urea breath test when a single test was positive). All children had histology together with CLO-test. Tissue culture was performed whenever possible.
Five hundred thirty infected children (10.4 +/- 3.0 years) and 1060 controls (7.3 +/- 4.4 years) were studied. Sensitivity of CLO-test was 83.4% (95% CI, 79.9-86.3%), of culture 84.6% (95% CI, 78.7-89.1%), of histology 93.2% (95% CI, 90.7-95.1%), and specificity 99% (95% CI, 98.2-99.4%), 100%, and 100% respectively. CLO-test positivity was correlated with higher bacterial density (p < .001), activity (p < .001) and severity of gastritis (p < .01), older age (p < .01), and the presence of antral nodularity (p < .001). When CLO-test was positive, the concordance with histology and culture was high (95.5 and 89.2% respectively), whereas low concordance was observed when CLO-test was negative (17.05 and 45.83% respectively).
CLO-test had lower sensitivity and comparable specificity with histology. Both tests should be performed concurrently to accurately diagnose H. pylori infection in children.
Helicobacter 06/2010; 15(3):227-32. · 3.15 Impact Factor
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ABSTRACT: To assess whether the polymorphisms of NOD2/CARD15, autophagy-related 16-like 1 (ATG16L1), and interleukin-23 receptor (IL23R) genes play a more critical role in the susceptibility of childhood-onset than in adult-onset Crohn's disease (CD).
Polymorphisms R702W, G908R, and 3020insC of NOD2/CARD15; rs2241880 A/G of ATG16L1, and rs11209026 (R381Q) of IL23R gene were assessed in 110 childhood-onset CD, 364 adult-onset CD, and 539 healthy individuals. Analysis of polymorphisms R702W, G908R, and 3020insC of NOD2/CARD15 genotyping was performed by allele specific polymerase chain reaction (PCR) or by PCR-restriction fragment length polymorphism analysis. The polymorphisms rs2241880 A/G of the ATG16L1, and rs11209026 (R381Q) of the IL23R gene in the children's cohort were genotyped by PCR and melting curve analysis whereas adult group genotyping was performed using the Affymetrix Genome-Wide Human SNP Array 5.0 (500K).
The 3020insC allele in NOD2/CARD15 was significantly higher in childhood than in adult-onset CD (P = 0.0067). Association with at least 1 NOD2/CARD15 variant was specific for ileal disease (with or without colonic involvement). Even if the frequency of G allele of the rs2241880 ATG16L1 polymorphism was increased in both paediatric and adult CD patients compared to controls (P = 0.017 and P = 0.001, respectively), no difference was observed between the childhood and the adult cohort. The rare Q allele of IL23R rs11209026 polymorphism was underrepresented in both paediatric and adult CD cases (P = 0.0018 and P = 0.04, respectively) and no difference was observed between the childhood and the adult cohort. The presence of the rs2241880 ATG16L1 and rs11209026 IL23R polymorphisms did not influence disease phenotype.
Polymorphism 3020insC in NOD2/CARD15 occurs statistically significantly more often in patients with childhood-onset CD than in patients with adult-onset CD. The ATG16L1 and IL23R variants are associated with susceptibility to CD, but not early-onset disease.
World Journal of Gastroenterology 04/2010; 16(14):1753-8. · 2.47 Impact Factor
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Pediatric Nephrology 02/2010; 25(8):1573-4. · 2.52 Impact Factor
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ABSTRACT: The presence of various numbers of EPIYA tyrosine phosphorylation motifs in the CagA protein of Helicobacter pylori has been suggested to contribute to pathogenesis in adults. In this prospective study, we characterized H. pylori isolates from symptomatic children, with reference to the diversity of functional EPIYA motifs in the CagA protein and vacA isotypes, and assessed the potential correlation with the histopathological manifestations of the infection. We analyzed 105 H. pylori isolates from 98 children and determined the diversity of EPIYA motifs in CagA by amplification and sequencing of the 3' variable region of the cagA gene as well as vacA isotypes for the signal, middle, and intermediate regions. CagA phosphorylation and levels of secreted IL-8 were determined following in vitro infection of AGS gastric epithelial cells. Histopathological evaluation of H. pylori colonization, activity, and severity of the associated gastritis was performed according to the updated Sydney criteria. EPIYA A (GLKN[ST]EPIYAKVNKKK), EPIYA B (Q[V/A]ASPEPIY[A/T]QVAKKVNAKI), and EPIYA C (RS[V/A]SPEPIYATIDDLG) motifs were detected in the ABC (46.6%) and ABCC (17.1%) combinations. No isolates harboring more than two EPIYA C motifs in CagA were found. The presence of isogenic strains with variable numbers of CagA EPIYA C motifs within the same patient was detected in seven cases. Occurrence of increasing numbers of EPIYA C motifs correlated strongly with presence of a high-vacuolation (s1 or s2/i1/m1) phenotype and age. A weak positive correlation was observed between vacuolating vacA genotypes and presence of nodular gastritis. However, CagA- and VacA-dependent pathogenicities were not found to contribute to severity of histopathology manifestations in H. pylori-infected children.
Journal of clinical microbiology 07/2009; 47(8):2426-34. · 4.16 Impact Factor
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Journal of pediatric gastroenterology and nutrition 02/2009; 48(1):1. · 2.18 Impact Factor
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ABSTRACT: A high incidence of Helicobacter pylori among family members of children with H. pylori gastritis has previously been documented on biopsy material. The main objective of this study was the genetic clarification of H. pylori strains involved in intrafamilial dispersion.
Formalin-fixed, paraffin-embedded material of antral mucosa from 32 members of 11 families was studied for the presence of genetic homogeneity. To achieve this goal, the entire genome of H. pylori was studied by the polymerase chain reaction (PCR)-based random amplified polymorphic DNA (RAPD) fingerprinting method. Furthermore, the Urease A gene was analyzed using a multiplex PCR-assay and an alternative mutation detection method based on the Hydrolink trade mark analysis.
RAPD fingerprinting confirmed that closely related H. pylori strains were involved in the intrafamilial dispersion. Mutations and small deletions in Urease A gene were found in 22 out of 32 individuals.
The homology of the H. pylori genome in members of the same family strongly supports the hypothesis of transmission of H. pylori from person-to-person or from a common source.
Helicobacter 03/2003; 8(1):15-20. · 3.15 Impact Factor
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ABSTRACT: In the past year the main interest was focused on the role of family for transmission of Helicobacter pylori to children; the evaluation of noninvasive diagnostic tests, especially in young children; extra-intestinal clinical manifestations; the lack of consensus on treatment; and the problem of high resistance of the microorganism to antibiotics.
Helicobacter 02/2002; 7 Suppl 1:50-5. · 3.15 Impact Factor
