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Biomedical subjects

Christophe Dupont

Publications and source records attributed to Christophe Dupont.

17 recordsLinked to original sources
PubMed2006

Effect of oligofructose supplementation on gut microflora and well-being in young children attending a day care centre.

The effect of daily administration of oligofructose (OF) on 7-19 months old healthy children intestinal microflora, intestinal tolerance and well-being was assessed in a double blind placebo controlled study. The study comprised 8 days of observation, 21 days of supplementation, and 15 days of post-supplementation. Exclusion criteria included antibiotic use and intake of other prebiotic and probiotic at any time following enrolment. Faecal flora was analysed by culture methods, and health information was recorded daily. Bifidobacteria, tended to slightly increase with OF supplementation, but not with placebo (p=0.095). Simultaneously, a decrease in potential pathogens, significant for clostridia (p=0.05) but not for staphylococci (p=0.09) was observed in the OF group. These modifications did not persist during the post-supplementation period. OF supplementation were accompanied by less flatulence, diarrhoea, vomiting (p<0.001), and fever (p<0.05) events.

Bifidobacterium↗
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

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↗
PubMed2006

Early nutrition and immunity - progress and perspectives.

The immune system exists to protect the host against pathogenic organisms and highly complex pathways of recognition, response, elimination and memory have evolved in order to fulfil this role. The immune system also acts to ensure tolerance to 'self', to food and other environmental components, and to commensal bacteria. A breakdown in the tolerogenic pathways can also lead to inflammatory diseases. The prevalence of inflammatory diseases, including atopic disorders, has increased over the last 60 years. The development of tolerance is the result of active immune mechanisms and both development and maintenance of tolerance are lifelong processes which start very early in life, even prenatally. Profound immunologic changes occur during pregnancy, involving a polarization of T helper (Th) cells towards a dominance of Th2 and regulatory T cell effector responses in both mother and fetus. This situation is important to maintain pregnancy through avoidance of the rejection of the immunologically incompatible fetus. During the third trimester of human pregnancy, fetal T cells are able to mount antigen-specific responses to environmental and food-derived antigens and antigen-specific T cells are detectable in cord blood in virtually all newborns indicating in utero sensitization. If the neonatal immune system is not able to down-regulate the pre-existing Th2 dominance effectively then an allergic phenotype may develop. Changes occur at, and soon after, birth in order that the immune system of the neonate becomes competent and functional and that the gut becomes colonized with bacteria. Exposure to bacteria during birth and from the mother's skin and the provision of immunologic factors in breast milk are amongst the key events that promote maturation of the infant's gut and gut-associated and systemic immune systems. The introduction of formula and of solid foods exposes the infant to novel food antigens and also affects the gut flora. Nutrition may be the source of antigens to which the immune system must become tolerant, provide factors, including nutrients, that themselves might modulate immune maturation and responses, and provide factors that influence intestinal flora, which in turn will affect antigen exposure, immune maturation and immune responses. Through these mechanisms it is possible that nutrition early in life might affect later immune competence, the ability to mount an appropriate immune response upon infection, the ability to develop a tolerogenic response to 'self' and to benign environmental antigens, and the development of immunologic disorders. A Workshop held in February 2006 considered recent findings in the areas of oral tolerance, routes of sensitization to allergens and factors affecting the development of atopic disease; factors influencing the maturation of dendritic cells and the development of regulatory T cells; the influence of gut microflora on immunity, allergic sensitization and infectious disease; the role of nutrition in preventing necrotizing enterocolitis in an animal model of preterm birth; and the role of PUFA of different classes in influencing immune responses and in shaping the development of atopic disease. This report summarizes the content of the lectures and the subsequent discussions.

Animals↗
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

Double-blind randomized evaluation of clinical and biological tolerance of polyethylene glycol 4000 versus lactulose in constipated children.

OBJECTIVES: To assess the safety of a polyethylene glycol (PEG) 4000 laxative without additional salts in pediatric patients. STUDY DESIGN: This was a 3-month multicenter, randomized, double-blind, double-dummy, lactulose-controlled, parallel study enrolling 96 ambulatory constipated children aged 6 months to 3 years, treated daily with 4-8 g PEG or 3.33 g-6.66 g lactulose. Total protein, albumin, iron, electrolytes, and vitamins B9 (folates), A and D (25OHD3) were measured in blood before and after treatment (day 84) in a central laboratory. RESULTS: The percentage of children with at least one value out of normal range at day 84 with respect to baseline status (with or without at least one value out of normal range), i.e. the primary endpoint, was 87% and 90% in the PEG and lactulose groups, respectively, without any difference between groups. The whole blood parameters showed no qualitative or quantitative treatment-related changes. Vitamin A values were above normal range in 56% and 41% of children at baseline versus 33% and 36% at day 84 in the PEG and lactulose groups, respectively. Iron values were similarly under normal range in 47% and 51% at baseline versus 42% and 51% at day 84. Clinical tolerance was similar for both treatments except for vomiting and flatulence, which were significantly higher with lactulose. Significantly higher improvements were evidenced with PEG regarding stool consistency, appetite, fecaloma and use of additional laxatives. CONCLUSION: This 3-month study in 96 constipated children aged 6 months to 3 years confirms the long-term tolerance of PEG 4000 in pediatrics and indicates a PEG efficacy similar to or greater than that of lactulose.

Cathartics↗
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

Developmental pharmacokinetics and pharmacodynamics of nizatidine.

OBJECTIVES: To characterize the impact of development on the pharmacokinetics and pharmacodynamics of nizatidine. METHODS: Children (age range, 5 days-18 years) and adults (age range, 18-50 years) were enrolled in four open-label trials. Nizatidine formulation and dose were determined by age: infants received 2 or 4 mg/kg i.v., children 2.5 or 5 mg/kg in one of three oral liquid formulations, and adolescents and adults received a fixed 150-mg capsule. Nizatidine and N-desmethylnizatidine concentrations were measured in serial post-dose plasma samples by a high-performance liquid chromatographic assay with mass spectrometric detection. Intragastric pH was recorded during a 24-hour post-dose interval. RESULTS: Data on 93 subjects were combined with previous values from 36 individuals to cover an age group not adequately captured and to control for formulation effects. Dose-normalized exposure estimates revealed no apparent age dependence; however, maximum plasma concentration (298.5 +/- 100.7 v 552.8 +/- 152.4 ng/mL per mg/kg dose) and AUC0-infinity (954.4 +/- 379.8 v 1,573.0 +/- 347.4 ng*hour/mL per mg/kg dose) were reduced in extemporaneous formulations in apple juice. The apparent modest age dependence observed for total body clearance (Cl/F) (r = 0.365) and Vss/F (r = 0.221) reflected a formulation-dependent decrease in bioavailability rather than a true age effect. The age-associated changes in lambda z observed for nizatidine and its metabolite were predictable and consistent with developmental acquisition of renal function. Mean and median pH, as well as fraction of time that the dosing interval remained above target pH values, were significantly greater with administration of the drug than without. CONCLUSIONS: The biodisposition of nizatidine in children and adults is similar; however, response after a comparable weight-based dose is equal and potentially greater in children.

Administration, Oral↗
PubMed2003

Protein requirements during the first year of life.

The composition of human milk provides the model for estimated total protein and essential amino acid requirements during infancy. However, both the total protein content and the concentrations of individual proteins in human milk change throughout the first year of lactation. Recent reassessments of estimated requirements have resulted in lower total protein recommendations and have emphasized the provision of alpha-amino nitrogen because most nonprotein nitrogen is not used for maintenance or tissue deposition. In clinical studies, formulas containing various whey-to-casein ratios and having total protein concentrations in the range of 13-15 g/L were shown to promote adequate growth and to result in biochemical measures of protein nutritional status similar to those in breastfed infants. In the second half of infancy, human milk can provide most of the protein needed, provided a modest protein supply is obtained from weaning foods. In special situations in which greater protein intakes are desired, special preparations of protein might be needed.

Dietary Proteins↗
PubMed2002

Pharmacokinetic-pharmacodynamic study of oral lansoprazole in children.

OBJECTIVE: We investigated the pharmacokinetics, pharmacodynamics, and tolerability of lansoprazole in children after single and multiple administrations. METHODS: Forty children (age range, 18 days-14 years) with gastric acid-related disorders entered an open study and received lansoprazole in a single dose of 17 mg. m(-2) (group A) or in multiple doses (17 mg. m(-2) per day) for 7 to 14 days (group B). Lansoprazole plasma concentrations were measured by HPLC. A 24-hour intragastric pH monitoring assessed the antisecretory effect. RESULTS: In group A, maximal concentration (C(max)) was 1023 +/- 775 (mg. L(-1))/(17 mg. m(-2)), time to reach C(max) was 1.8 +/- 0.8 hours, elimination half-life was 1.5 +/- 2.0 hours, area under the concentration-time curve from time zero to infinity [AUC(0-infinity)] was 3503 +/- 6025 (mg. L(-1). h)/(17 mg. m(-2)), apparent plasma clearance was 0.57 +/- 0.47 L. h(-1). kg(-1), and apparent volume of distribution was 0.61 +/- 0.36 L. kg(-1). In group B, C(max) was 750 +/- 511 (mg. L(-1))/(17 mg. m(-2)), time to reach C(max) was 1.8 +/- 1.1 hours, elimination half-life was 1.2 +/- 1.1 hours, AUC(0-infinity) was 2351 +/- 3691 (mg. L(-1). h)/(17 mg. m(-2)), apparent plasma clearance was 0.71 +/- 0.50 L. h(-1). kg(-1), and apparent volume of distribution was 0.9 +/- 0.7 L. kg(-1). No influence of age was shown on pharmacokinetic parameters in both groups. However, data suggested that elimination was reduced in neonates and higher in infants than in adults. The values for 24-hour percentage of time at gastric pH <4 and pH <3 were 61% +/- 21% and 51% +/- 21% (group A) and 47% +/- 24% and 37% +/- 21% (group B), respectively. In both groups the antisecretory effect decreased with age, and in group A it was positively correlated to C(max) and AUC(0-infinity). The mean gastrin serum concentration significantly increased (+31%) after 12.6 +/- 1.5 days of treatment. CONCLUSIONS: Lansoprazole was well tolerated in children. After a single oral dose of 30 mg per 1.73 m(2), there was a trend for the elimination to be higher in infants than in adults and the antisecretory effect appeared to be higher in infants younger than 6 months than in older children and adults.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2002

Allergy to extensively hydrolyzed cow's milk proteins in infants: safety and duration of amino acid-based formula.

Infants (n = 52) allergic to cow's milk protein and extensively hydrolyzed formulas received an amino acid-based formula. The amino acid-based formula proved to be safe, with infants exhibiting an overall gain in length and weight. Children with allergy restricted to extensively hydrolyzed formulas were diagnosed earlier and tolerated cow's milk protein earlier than children with multiple food allergy.

Amino Acids↗
PubMedDate not supplied

Correlation between gastric acid secretion and severity of acid reflux in children.

The purpose of our study was to systematically evaluate gastric acid output in children with long-lasting gastro-esophageal reflux (GER) in order to assess its mechanism and the need for anti-acid treatment. The investigation was carried out in 20 males and 10 females, aged 7.5 +/- 3.8 years, with prolonged (>15 months) clinical manifestations of GER. All underwent routine ambulatory 24-h esophageal pH-monitoring and measurement of gastric acid secretion including gastric basal (BAO) (micromol/kg/h), maximal (MAO) and peak acid outputs (PAO) after pentagastrin (6 microg/kg sec) stimulation. Children with heartburn or abdominal pain underwent upper fiber-endoscopy. In group A (moderate GER, n=12), patients had a normal reflux index (pH<4 below 5.2% of total recording time) despite abnormal Euler and Byrne scoring (median 57, 95% confidence interval 53.5-73.4). In group B (severe GER, n=18, among whom 5 were with grade III esophagitis), reflux index was >5.2%. When considering all children, esophageal pH (%) was significantly correlated with MAO and PAO, r=0.33, p=0.05 and r=0.37, p=0.04, respectively. Children of group B exhibited significantly higher BAO (75, 53.96-137.81), MAO (468, 394.1-671.3) and PAO (617, 518.8-782.3) than those of group A, BAO (27, 10.8-38.5), MAO (266, 243.2-348.2) and PAO (387, 322.5-452.7), p<0.05). The five children of group B with severe esophagitis exhibited significantly higher BAO, MAO and PAO than the other 13 children from the same group and those of group A, p<0.05. Children with long-lasting and severe GER hyper-secrete gastric acid. Individual variations in gastric acid secretion probably account for variations in gastric acid inhibitor requirements. Anti-secretory treatment is justified in children with long-lasting GER and high pH-metric reflux index.

Adolescent↗