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Biomedical subjects

Nicolas Kalach

Publications and source records attributed to Nicolas Kalach.

At least 19 recordsLinked to original sources
PubMed2006

Intra-familial transmission of Helicobacter pylori infection in children of households with multiple generations in Vietnam.

This community-based cross-sectional study in 533 participants from 135 households with multiple generations living in the same household aimed at investigating the relationship between Helicobacter pylori infection in children and the other household members. H. pylori infection in children was found significantly associated with the infection in mothers [OR (95% CI): 2.50 (1.19-5.26)], even after being adjusted for sex, age group and sibling number [adjusted OR (95% CI): 2.47 (1.12-5.47)]. It was also significantly associated with the infection in both parents [adjusted OR (95% CI): 4.14 (1.29-13.23)]. No significant association between H. pylori infection in the father, grandparent(s), uncle or aunt with that in their children was found. Results from the present study showed intra-familial transmission in a multi-generation population and supported the hypothesis of person-to-person transmission of H. pylori infection.

Adolescent↗
PubMed2006

Assessment of a rapid urinary antigen detection by an immunochromatographic test for diagnosis of pneumococcal infection in children.

The aim of the study was to evaluate the Binax Now rapid immunochromatographic test (ICT) for the detection of Streptococcus pneumoniae urinary antigen in children suffering from potentially pneumococcal infections. A total of 287 patients, with a median age of 34.9 months and divided into 3 groups, were studied; the first group of patients with a suspected pneumococcal infection (n = 112), the second group with infectious symptoms nonsuggestive of a pneumococcal infection (n = 54), and the third group was composed of asymptomatic children (n = 121). In group 1, sensitivity of ICT was 100% and specificity was 55.9% (95% confidence interval, 44.1- 67.7). Forty-six (85.1%) patients from the second group were true negatives. Twenty-five (20.7%) patients from the third study group were nasopharyngeal pneumococcal carriers, and the ICT was positive in 13 carriers (10.7%). The high sensitivity level of ICT in our study indicates that a negative test could rule out a pneumococcal infection, contrasted with a poor specificity.

Antigens, Bacterial↗
PubMed2006

[Helicobacter pylori infection in children].

Helicobacter pylori infection is basically acquired during infancy. H. pylori is associated with a great number of pathologies including gastritis, gastroduodenal peptic ulcer, gastric adenocarcinoma and MALT lymphoma. Its association with abdominal pain in children remains controversial. An association with iron deficiency anemia was recently described. The reference method for diagnosis still remains culture and histology of gastric biopsies realized during endoscopy. A few years ago, a lot of studies have shown the reliability of non-invasive tests (urea breath test 13C and the H. pylori stool antigen) for the diagnosis of the H. pylori infection in children. The treatment associating a proton pump inhibitor with two antibiotics (depending on the antimicrobial susceptibility when it's available) is recommended every time infection is proved. In children, the reinfection rate after H. pylori eradication is often higher than in adults. The eradication of H. pylori infection does not seem to produce the advent or the aggravation of gastro-oesophageal reflux oesophagitis. The eradication of this pathogen, in children as well as in adults, should theoretically lead to the disappearance of gastric cancer.

Adenocarcinoma↗
PubMed2006

A dose determination study of polyethylene glycol 4000 in constipated children: factors influencing the maintenance dose.

OBJECTIVES: To determine the doses of polyethylene glycol (PEG) 4000 without additional salts allowing normal bowel habits in childhood functional constipation. METHODS: This multicenter noncomparative study allocated children to 4 groups: 6-12 months, 13 months-3 years, 4-7 years, and 8-15 years. Constipation was defined as <1 stool/d for more than 1 month in children aged 6-12 months and <3 stools/w for more than 3 months in older children. Children randomly received either a nominal or a double starting dose. Treatment scheduled for 3 months could be adapted. Data were collected daily by the parents and rated at each visit by the investigator. RESULTS: In the 96 children included, the median (interquartile) effective daily doses were by groups; 3.75 (2.50-5.00) g, 6.00 (4.00-7.43) g, 11.71 (7.00-16.00) g, and 16.00 (16.00-24.00) g, respectively, i.e., around 0.50 g/day/kg with a potential increment of the maintenance dose with higher initial dosages. More children had a final dosage identical to the initial one when started on the nominal dose (73%) than with the double one (42%, P < 0.003). More than 90% of children recovered normal bowel habits. Fecal soiling ceased in >60% of children with this symptom at enrolment. Fecal mass in the rectum and abdominal pain were markedly reduced and appetite improved. CONCLUSIONS: A daily dose of PEG 4000 around 0.50 g/day/kg in children aged 6 months to 15 years is effective in more than 90% of constipated children and 60% of those with fecal soiling.

Adolescent↗
PubMed2006

High rate of Helicobacter pylori reinfection in children and adolescents.

AIMS: Primary Helicobacter pylori infection occurs predominantly in childhood. The aims of this study were to establish the rate of H. pylori reinfection after successful eradication in children and adolescents and to determine the risk factors associated with reinfection. PATIENTS AND METHODS: This retrospective study involved 45 children (20 girls, 25 boys) who met the following criteria: eradication of H. pylori confirmed at least 4 weeks after the completion of therapy, and the search for reinfection at least one year after control of eradication of H. pylori. Demographic data, socioeconomic status and living conditions were recorded. RESULTS: Forty-five children aged 1.2-17.6 years (median, 10.9 years) at the time of H. pylori treatment were reviewed 1 to 9 years after H. pylori eradication. Eight children (18%) had been reinfected (5.4% to 6% per patient-year). Six of 25 (24%) children older than 10 years at the time of diagnosis became reinfected. None of the studied risk factors was associated with reinfection. However, having a sibling younger than 5 years was found in four of seven (57%) reinfected children versus five of 24 (21%) nonreinfected children (p = .08). CONCLUSION: Children become reinfected more frequently than adults. Adolescents become reinfected, whereas acquisition of primary H. pylori infection occurs predominantly in early childhood. Close contact with young children, especially siblings, younger than 5 years could be a more important risk factor than the age of the patient at the time of treatment for the high rate of reinfection in childhood.

Adolescent↗
PubMed2006

Prevalence of and factors associated with Helicobacter pylori infection in children in the north of Vietnam.

The study aimed at evaluating the seroprevalence of and sociodemographic, health, lifestyle, and environmental hygiene conditions associated with Helicobacter pylori infection in Vietnamese children. Data from 824 children, aged from 6 months to 15 years and gastrointestinal symptom free when consulted, admitted to a university hospital, were collected using a structured questionnaire and ELISA test for H. pylori infection. The data were examined using univariate and multivariate analyses. H. pylori seroprevalence was 34.0%. Age groups from 3 to 6 years and older than 6, and number of offspring were positively and independently associated with H. pylori seropositivity [adjusted OR (95% CI): 2.9 (1.5-5.5); 1.9 (1.1-3.1) and 1.8 (1.1-2.6), respectively]. Breastfeeding more than 6 months was negatively and independently associated with H. pylori seropositivity [adjusted OR (95% CI): 0.5 (0.3-0.9)]. Mother's age, history of allergy, gastro-duodenal disease history in the past, initiating collective life before 6 years, sharing bed with parents and time of bed sharing with parents > 24 months were positively but not independently associated with H. pylori seropositivity. None of the other environmental or lifestyle conditions examined was associated with H. pylori infection. Our results support person-to-person transmission and the role of sociodemographic factors in H. pylori infection.

Adolescent↗
PubMed2005

A pilot study of the usefulness and safety of a ready-to-use atopy patch test (Diallertest) versus a comparator (Finn Chamber) during cow's milk allergy in children.

BACKGROUND: Patch testing is used in the diagnosis of food allergy, especially during delayed manifestations. OBJECTIVE: A ready-to-use atopy patch test (APT), the Diallertest, was compared with another APT device, the Finn Chamber, in pediatric cow's milk allergy. METHODS: This prospective study involved 49 children (34.3 +/- 17 [mean +/- SD] months of age), with cow's milk allergy manifested by atopic dermatitis (10.2%), digestive manifestations (40.8%), or both (49%). All children underwent both APT techniques, with a reading 72 hours after application, followed by a milk elimination diet for 4 to 6 weeks and open cow's milk challenge. RESULTS: A positive result was seen in 22 (44.8%) versus 13 (26.5%) patients with the ready-to-use and the comparator APTs, respectively. No side effects were recorded. Both techniques were concordant in 67.3% of patients. Of the total 41 open cow's milk challenges, 60.9% had positive results, with 8 patients lost to follow-up. The performances of the ready-to-use and comparator APTs were as follows: sensitivity, 76% (95% CI, 59.2% to 92.7%) versus 44% (95% CI, 24.5% to 63.4%; P = .02); specificity, 93.8% (95% CI, 81.9% to 100%) versus 93.8% (95% CI, 81.9% to 100%); positive predictive value, 95% (95% CI, 85.4% to 100%; 1 false-positive result) versus 91.7% (95% CI, 76% to 100%; 1 false-positive result); negative predictive value, 71.4% (95% CI, 52% to 90.7%; 6 false-negative results) versus 51.7% (95% CI, 33.5% to 69.8%; 14 false-negative results); and test accuracy, 82.9% (95% CI, 71.3% to 94.5%) versus 63.4% (95% CI, 48.6% to 78.1%; P = .05). CONCLUSION: The ready-to-use APT exhibited a good sensitivity and specificity, with no side effects.

Child↗
PubMed2005

Usefulness and influence of age of a novel rapid monoclonal enzyme immunoassay stool antigen for the diagnosis of Helicobacter pylori infection in children.

A novel rapid monoclonal enzyme immunoassay stool antigen for Helicobacter pylori detection (Immunocard STAT!HpSA, Meridian Diagnostic Inc , Cincinnati, OH) was evaluated in 29 infected and 99 noninfected children. The overall sensitivity, specificity, and positive and negative predictive values were 86.2%, 92.9%, 78.1%, and 95.8%, respectively, with an accuracy of 91.4%. The highest performance was observed in children older that 10 years, with a sensitivity level of 100%, contrasting with a lower level, 75%, in those younger than 5 years. A good negative predictive value was observed in all age groups, particularly in older children achieving 100%.

Adolescent↗
PubMed2005

Heterogeneous susceptibility to metronidazole and clarithromycin of Helicobacter pylori isolates from a single biopsy in adults is confirmed in children.

The aim of this study was to assess the resistance to metronidazole and clarithromycin of individual colonies of Helicobacter pylori from a single biopsy taken from 14 adults and 14 children. The Etest was used to determine the minimum inhibitory concentrations (MICs) of these two antimicrobial drugs for ten individual H. pylori colonies isolated from each initial gastric biopsy culture. We confirmed the heterogeneity in metronidazole and clarithromycin resistance in children as seen in adults before anti-H. pylori treatment. The number of resistant individual colonies ranged from two to nine depending on the subject. All individual colonies from the same biopsy that were resistant to clarithromycin were genetically identical according to randomly amplified polymorphic DNA testing and exhibited the same point mutation according to polymerase chain reaction-restriction fragment length polymorphism.

Adult↗
PubMed2005

Digestive endoscopy in neonates.

Since the introduction of flexible fiberoptic endoscopy in the early 1970s, esophagogastro-duodenoscopy and colonoscopy have become established procedures for the diagnosis, evaluation and treatment of gastrointestinal tract disease in the pediatric population. The development of safe fiberoptic endoscopes specially designed for neonates has allowed visualization of lesions occurring in the first days of life. Despite an increased understanding of neonatal digestive disorders deriving from this new diagnostic modality, there is little consensus on the appropriate use of endoscopic procedures in routine care of neonates. It is the feeling of the authors that widening the indications of endoscopy in the neonatal period might lead to diagnosis of discrete clinical abnormalities, which might improve the care of neonates. The techniques for performing neonatal endoscopies, the appropriate indications, the common normal and pathologic findings and the complications of these procedures are reviewed.

Digestive System↗
PubMed2005

Helicobacter pylori infection is not associated with specific symptoms in nonulcer-dyspeptic children.

OBJECTIVES: To assess symptoms associated with Helicobacter pylori infection in children presenting with nonulcer dyspepsia (NUD). STUDY DESIGN: A prospective double-blind study was conducted between March 2001 and April 2002 in children at least 6 years old with NUD who had been referred for upper gastrointestinal endoscopy for epigastric pain. A standardized questionnaire was administered blindly by a pediatric gastroenterologist. This questionnaire characterized epigastric pain and associated factors. Infection was confirmed by positive culture and histologic examination of the gastric mucosa. RESULTS: From 100 children enrolled, 26 proved infected (12 female, 14 male; mean age: 11.4 +/- 2.6 years), and 74 were noninfected (44 female, 30 male; mean age: 10.4 +/- 3.1 years). There were no differences in age or symptom characteristics between groups except for epigastric pain during meals that was more frequent in noninfected than in infected children (25.6% vs 3.8%). CONCLUSION: There were no specific characteristics of symptoms in nonulcer-dyspeptic H pylori-infected children as compared with noninfected children.

Adolescent↗
PubMed2005

Time course of total and food specific IgE antibodies (Rast Fx5) in the developing allergic child.

AIM: To analyze the evolution of total and food specific IgE (Rast Fx5) titers in the course of food allergy in children. PATIENTS & METHODS: 925 children, mean age 8.9 + 9.1 years (15 days-18 years), 455 girls and 470 boys, investigated for food allergy in year 1997, underwent serum samples assay for total IgE and of Rast Fx5, Cap System, Pharmacia & Upjohn Diagnostics AB, Uppsala, Sweden, a mix test detecting specific IgE to 6 major food allergens in children, cow's milk proteins (CMP), egg white, peanut, soy, wheat and fish and analyzed as a function of reference values by age. RESULTS: Total IgE titers increased significantly with age, r0.22, p0.0001. The percentage of children with a total IgE level above normal range first increased with age, from 10.3 % at 0-6 months, reaching 38.2 % at 1-2 years and peaking at 56.9% at 4-6 years, then leveled off, 48.1% at 8-12 years (ns vs 4-6 years) and 41.3% above 12 years (ns). Detectable Rast Fx5 increased in a parallel manner until age 4-6 years and then exhibited a progressive decrease from age 6-8 years, differing significantly from total IgE: 31.9% vs 52.9%, p0.01 (6-8 years), 32.2% vs 48.1%, p0.03 (8-12 years), 21.8% vs 41.3%, p0.05 (> 12 years). CONCLUSION: In these outpatient children investigated for food allergy, the increase with age of the percentage of high total IgE contrasted with the progressive decrease of Rast Fx5 from age 4-6 yr. This biological finding correlates timely with the clinical spontaneous decrease of food allergy in the developing child.

Adolescent↗
PubMed2004

Increased poliovirus-specific intestinal antibody response coincides with promotion of Bifidobacterium longum-infantis and Bifidobacterium breve in infants: a randomized, double-blind, placebo-controlled trial.

To determine whether the size of the intestinal bifidobacterial population can influence the immune response to poliovirus vaccination in infants, we set up a randomized, placebo-controlled trial. From birth to 4 mo, infants were given a fermented infant formula (FIF) or a standard formula (placebo). Bifidobacteria were quantified monthly in infant stools. Antipoliovirus IgA response to Pentacoq was assessed before and 1 mo after the second vaccine injection. Thirty infants were randomized, and 20 completed the study (nine in the placebo group and 11 in the FIF group). Fecal bifidobacterial level was significantly higher with the FIF group at 4 mo of age (p=0.0498). Furthermore, B. longum/B. infantis carriage was higher at 4 mo in the FIF group (p=0.0399). Antipoliovirus IgA titers increased after Pentacoq challenge (p <0.001), and the rise was significantly higher in the FIF group (p <0.02). Antibody titers correlated with bifidobacteria, especially with B. longum/B. infantis and B. breve levels (p <0.002). Infants who harbored B. longum/B. infantis also exhibited higher levels of antipoliovirus IgAs (p <0.002). In conclusion, the present results indicate that antipoliovirus response can be triggered with a fermented formula that is able to favor intestinal bifidobacteria. Whether this effect on the immune system is achieved through the bifidogenic effect of the formula (mainly through B. longum/B. infantis and B. breve stimulation) or directly linked to compounds (i.e. peptides) produced by milk fermentation remains to be investigated.

Bifidobacterium↗
PubMed2004

Gastroesophageal reflux disease and Helicobacter pylori infection in neurologically impaired children: inter-relations and therapeutic implications.

BACKGROUND: The aim of this retrospective study was to assess the relationship between Helicobacter pylori infection and gastroesophageal reflux disease in a high-risk population of children. METHODS: Forty-three neurologically impaired pediatric patients with H. pylori had upper gastrointestinal endoscopy between 1990 and 2000. Infection was confirmed by positive H. pylori culture or by identification of organisms in gastric biopsy specimens (fundus, n = 2; antrum, n = 3). Reflux esophagitis was diagnosed by ulceration of the esophageal mucosa at endoscopy. Four to 6 weeks after the completion of antibiotic treatment of H. pylori, a second endoscopy was performed and the gross appearance of the esophagus was recorded. RESULTS: At the first endoscopy, esophagitis was noted in 14 of 43 patients. After treatment, H. pylori infection was eradicated in all 14 patients with esophagitis but in only 19 of 29 (66%) of those with normal esophagus (P = 0.01). Esophagitis was still present in 4 of 14 (29%) patients who had esophagitis at the first endoscopy. Persistent esophagitis was only related to the presence of esophagitis before treatment (P = 0.02). In 29 patients with a normal esophagus at the first endoscopy, only one case of esophagitis was observed after H. pylori eradication. CONCLUSION: The data suggest that treatment of H. pylori infection should be considered in children with concomitant GERD, and such treatment is unlikely to either induce or exacerbate peptic esophagitis.

Adolescent↗
PubMed2004

Genetic and transmission analysis of Helicobacter pylori strains within a family.

To look for evidence of intrafamilial infection, we isolated 107 Helicobacter pylori clones from biopsied specimens taken from both parents and four children. We compared the sequences of two housekeeping genes (hspA and glmM) from these clones with those of 131 unrelated strains from patients living in different geographic regions. Strain relationships within the family were determined by analyzing allelic variation at both loci and building phylogenetic trees and by using multilocus sequence typing. Both hspA- and glmM-based phylogenetic trees showed East Asian and African branches. All samples from family members showed natural mixed infection. Identical alleles found in some strains isolated from the children and parents, but not in the strains isolated from unrelated patients, demonstrated that strains have circulated within the family. Several mechanisms, such as point mutations, intragenic recombination, and introduction of foreign (African) alleles, were shown to enhance strain diversity within the family.

Adolescent↗
PubMed2003

Helicobacter pylori infection in pediatrics.

A high prevalence and early colonization of Helicobacter pylori infection in childhood was described again this year in developing countries in contrast to developed ones. Upper gastrointestinal endoscopy including gastric biopsies remains the diagnostic gold standard method for this infection. Also noninvasive tests have been studied in children, including serology, 13C-urea breath test and stool antigen test, showing good results in the different age groups as compared to the gold standard. However, the infection often remains asymptomatic in children and the role of this bacterium in gastric manifestations is the subject of conflicting reports. Extra-digestive manifestations are also reported in the course of this infection. The treatment of H. pylori infection is influenced by resistance of the bacteria to the antibiotics used. We suggest that eradication of H. pylori should take place only after susceptibility testing. The association of a proton pump inhibitor and two antibiotics for 1 or 2 weeks gives the best eradication rates. The crucial question to elucidate is whether asymptomatic children should be treated to prevent cancer in the future.

Anti-Bacterial Agents↗