Comparison of fat oxidation during exercise in lean and obese pubertal boys: clinical implications.

OBJECTIVE: To examine fat oxidation rates during exercise in lean and obese pubescent children. DESIGN: A graded leg cycle ergometry test was performed by two groups of pubescent boys (13 lean: mean (SD) age 12.0 (0.5) years, body mass index (BMI) 18.56 (1.12) kg/m(2); 17 obese: mean (SD) age 12.1 (0.1) years, BMI 26.68 (3.37) kg/m(2); p<0.001). The first step of the test was fixed at 30 W and power was gradually increased by 20 W every 3.5 min. The mean ventilatory gas measurement was obtained during the last 30 s of each step for calculation of fat oxidation rate vs exercise intensity. RESULTS: At low intensity (0-30% of peak oxygen consumption) when fat-free mass is considered, the fat oxidation rate was identical for the two groups. At higher intensities (40%, 50% and 60% of peak oxygen consumption) the fat oxidation rate was significantly higher in lean boys than in obese boys. CONCLUSION: These results confirm that obese pubertal boys have fat-free mass decreased capacities to use fat during moderate exercise. The findings suggest that obese boys need to practise physical activity at a lower intensity than healthy boys to enhance lipolysis and diminish adipose tissue and the consequences of obesity.

Tracing of Enterobacter sakazakii isolates in infant milk formula processing by BOX-PCR genotyping.

AIMS: Enterobacter sakazakii is an emerging food-borne pathogen that can cause rare but severe neonatal meningitis, bacteraemia and necrotizing enterocolitis. Contaminated powder infant formulae (PIF) have been identified as one of various infection routes. In this study, E. sakazakii was monitored in the processing environment of a PIF factory to identify possible dissemination routes. METHODS AND RESULTS: The BOX-polymerase chain reaction (PCR), a fingerprinting technique which targets the repetitive BOX sequences, was used in routine to identify points of contamination and investigate clonal persistence. Two hundred E. sakazakii isolates were collected and typed. Most (70%) showed the same fingerprint that revealed the persistence of resident E. sakazakii strains in the processing environment. This method allowed to detect contamination of some PIF by dry-blending ingredients. CONCLUSIONS: Environment was the major cause for contamination of PIF and facilities. Some raw materials delivered as powder were also implicated. SIGNIFICANCE AND IMPACT OF THE STUDY: Routine BOX-PCR genotyping was very useful to trace and investigate in real-time dissemination of micro-organisms in the PIF plant and to implement a series of additional control measures to reduce the risk of final product contamination by E. sakazakii.

Genotypic characterization of Enterobacter sakazakii isolates by PFGE, BOX-PCR and sequencing of the fliC gene.

AIMS: Enterobacter sakazakii is an emerging food-borne pathogen that can cause rare but severe forms of neonatal meningitis, bacteraemia and necrotizing enterocolitis. A rapid typing method at the strain level is needed to determine the monoclonality or polyclonality of the isolates during outbreaks. METHODS AND RESULTS: The BOX-PCR fingerprinting technique, which targets the repetitive BOX sequences, and sequencing of the flagellin gene, fliC, were evaluated against a panel of 27 Ent. sakazakii strains from clinical and environmental sources. The typeability and discriminatory power of the techniques were compared with those of pulsed-field gel electrophoresis (PFGE), the reference genotyping method. BOX-PCR results yielded 92% agreement with PFGE results, whereas fliC gene sequencing was poorly discriminative. CONCLUSIONS: In our study, BOX-PCR and PFGE were similarly discriminatory to type Ent. sakazakii strains. The weak variability of the Ent. sakazakii fliC gene was related to the absence of the variable central domain present in most fliC genes of Enterobacteriaceae. SIGNIFICANCE AND IMPACT OF THE STUDY: The BOX-PCR typing provides an accurate discrimination and a rapid answer to identify clonal isolates of Ent. sakazakii.

Interactions between ethylenediaminetetraacetic acid (EDTA) and iron absorption pathways, in the Caco-2 model.

UNLABELLED: EDTA is a well known enhancer of iron absorption; however, the precise way of absorption of iron ingested in presence of EDTA is not known; some data suggest it could use a passive, non regulated paracellular way. Iron (sulphate or gluconate) absorption by Caco-2 cells was assessed in presence of EDTA. EDTA did not change the apical uptake of iron; transport in the basal chamber increased by 98% for FeSO4 and 95% for Fe gluconate. By contrast, intracellular storage decreased by 31% for FeSO4 and 64% for Fe gluconate. In addition EDTA induced a significant increase of permeability of the cell monolayer assessed by a decrease of transepithelial electrical resistance: 314+/-34 Omegacm(-2) to 235+/-57 Omegacm(-2) for sulphate, 414+/-33 Omegacm(-2) to 223+/-36 Omegacm(-2) for gluconate; iron free control: 410+/-10 Omegacm(-2). CONCLUSIONS: These results suggest that in presence of EDTA iron absorption occurs mainly by the paracellular instead of the regulated cellular way, that could potentially enhance its toxicity.

[Treatment of pediatric obesity: effects on body composition and physical fitness]. / Prise en charge ambulatoire de l'obésité: effets sur la composition corporelle et la capacité aérobie.

AIMS: To assess the efficiency of an ambulatory weight management programme of pediatric obesity, including 1 gymnastic session per week, on body composition and physical fitness (max). SUBJECTS: Fifteen adolescents participated in the 9-month intervention. BMI and fitness and physical activity assessed by a questionnaire were evaluated at baseline, and after intervention. RESULTS: Prepubescent subjects (N=6): no significant change of BMI, body composition, nor max. Pubescent subjects: significant decrease of BMI, and z score BMI, and % fat mass, increase of fat free mass. Activity questionnaire: non-significant trend to decreased TV watching, significant increase in practice of physical activity during weekend. CONCLUSION: A modest increase in physical practice, included in the dietary-behavioural management of adolescent obesity, is able to improve overweight and physical fitness.

[High cord blood TSH in Morocco: iatrogenic hypothyroidism?]. / TSH au cordon élevées au Maroc: hypothyroïdie iatrogène?

A short prospective study was conducted to assess thyroid status in healthy full term newborns (n=90) of a large maternity of Marrakech (Morocco), as part of the validation of a national salt iodisation program. High TSH (>5mU/l) was detected in 89% of infants tested; urinary iodine excretion was measured in 35 of the mothers, and was found to be normal (100-200microg/l) or high (>200microg/l)(n=27) in all of them. Milk iodine concentration was measured in 315 lactating women from the same area. Low values (<41microg/l) were found in 60% of them. The common use of iodinated disinfectants during delivery could be responsible for the high urine iodine values of mothers; however iodine deficiency seems to remain a widespread problem in this population and justifies a large scale survey of iodine status.

Molybdenum content of term and preterm human milk during the first 2 months of lactation.

To assess the molybdenum supply and requirements of preterm infants, Mo concentration was determined in milk from mothers of 6 term and 11 preterm newborns; no difference was found between fore- and hindmilk and no diurnal variations were found during 24-h collections. Respective values (means +/- SD) of term and preterm milks were 10.2 +/- 3.7 and 4.0 +/- 3.7 micrograms/L (106.2 +/- 38.5 and 41.7 +/- 38.5 nmol/L) at 3-5 d of lactation, 4.8 +/- 3.9 and 3.7 +/- 3.8 micrograms/L (50.0 +/- 4.6 and 38.5 +/- 39.6 nmol/L) at 7-10 d, 1.5 +/- 1.4 and 1.4 +/- 0.9 micrograms/L (15.6 +/- 14.6 and 14.6 +/- 9.6 nmol/L) at 14 d, 2.6 +/- 2.2 and 1.9 +/- 1.4 micrograms/L (27.1 +/- 22.9 and 19.8 +/- 14.6 nmol/L) at 1 mo, and 0.2 and 1.2 +/- 0.5 micrograms/L (2.1 and 12.5 +/- 5.2 nmol/L) at 2 mo. A statistical difference was found between term and preterm milk at 3-5 d of lactation. During lactation significant changes were found between the periods 3-5 d and 7-10 d, 14 d, 1 mo (p less than 0.01) and 2 mo (p less than 0.05) of lactation and between 7-10 d and 14 d (p less than 0.05). According to the requirements of the preterm infant, a supplementation of 2-3 micrograms.kg-1.d-1 by enteral route is suggested.

The composition of preterm milk in relation to the degree of prematurity.

Fifty-one samples of 24-h milk collections obtained during the 1st month of lactation from mothers who delivered after gestations of 26 to 31 wk (VPT) contained higher concentrations of nitrogen (297 +/- 11 mg/dl), total fatty acids (4.46 +/- 0.17 g/dl), percentage medium chain fatty acids (10.8 +/- 0.7), and energy (78.3 +/- 2.0 kcal/dl) than either or both those from 32 to 36 wk (PT) and term (T) gestations. PT collections did not differ from T milk with regard to nitrogen (250 +/- 13 versus 259 +/- 13), total fatty acids (3.94 +/- 0.20 versus 3.20 +/- 0.30), percentage medium chain fatty acids (9.1 +/- 0.5 versus 8.1 +/- 0.7) and energy (69.0 +/- 2.7 versus 66.6 +/- 2.4). Although postpartum age (5 to 10 versus 11 to 30 days) did not change the nutrient and energy content of VPT, PT, and T collections, it is only in 11 to 30 day VPT milk that nitrogen and energy content became higher (p less than 0.05) than either or both PT and T milk. We conclude that the differences in macronutrient composition of PT milk are limited to VPT milk and the data from repeated milk collections in the same mother (28 wk) suggest that there is considerable variability in its composition.

Early neurological and neuropsychological development of the preterm infant and polyunsaturated fatty acids supply.

OBJECTIVES: To compare the early neurological maturation of premature newborns (PT) fed breast milk (BM) or a formula containing only 18-carbon polyunsaturated fatty acids (PUFA) (A) or enriched with long chain (LC) PUFA (B). METHODS: PT enrolled the 2nd day of enteral feeding (D0) were fed BM (n = 15; 4 dropped out) or randomly assigned to A (n = 11; 2) or B (n = 14; 1) for at least 30 days (D30). Auditory and visual evoked potentials (EPs) and nerve conduction velocity (NCV) and plasma and red blood cell (RBC) phospholipid composition were determined at D0 and D30. No difference was found between groups for the D0-D30 changes in EP parameters. The maturation of motor NCV was slower in the B group than in the two other groups. In plasma, the changes were higher in B than in the BM and A groups for linoleic acid (P < 0.05), in BM versus B group for arachidonic acid (P < 0.02). In RBC, formula groups displayed higher linoleic acid level than the BM group (P < 0.05). No difference was found between groups for the changes in arachidonic and docosahexaenoic acids. CONCLUSIONS: A balanced supply of n-6 and n-3 PUFA without addition of LC-PUFA allowed an adequate early maturation of the central nerve system. The effects of LC-PUFA on the maturation of NCV remain to be confirmed.

Sensitivity of beta-casein phosphopeptide-iron complex to digestive enzymes in ligated segment of rat duodenum.

Binding iron to the phosphorylated beta(1-25) peptide derived from beta-casein improves iron bioavailability in the rat. The aim of the present work was to learn how injected beta(1-25) and iron-beta(1-25) complex behave in the duodenum of rats using the technique of intestinal ligation in situ and reversed-phase (RP)-high performance liquid chromatography-electrospray mass spectrometry analysis of the lumen contents. The results demonstrate that beta(1-25) is sensitive to digestive enzymes including proteases/peptidases and phosphatases during duodenal transit. The lumen contents of rats perfused with iron free beta(1-25) contained all peptidic sequences derived from beta(1-25). In contrast, the phosphorylated part of beta(1-25) [i.e., beta(15-24)] was not detected in lumen of rats perfused with iron-beta(1-25) complex.

Mechanisms of absorption of caseinophosphopeptide bound iron.

Binding iron (Fe) to the 1-25 caseinophosphopeptide obtained from enzyme hydrolysis of beta casein (beta CPP) improves Fe bioavailability in the rat. To assess the mechanisms involved in its absorption, a perfused, vascularized duodenal rat loop model was used in controls and in Fe-deficient (bleeding of 25% blood volume) rats. Inhibitors of oxidative phosphorylation [2-4 dinitrophenol (DNP)] and/or of endocytosis [phenylarsine oxide (PAO)] were added to the perfusion solution containing 50 microM Fe as beta CPP bound Fe (Fe-beta CPP) or gluconate (Fe Gluc). Fe-beta CPP enhanced Fe uptake, reduced mucosal storage, and improved net absorption both in controls and in deficient animals. DNP reduced uptake, mucosal storage, and net absorption by the same percentage in Fe-beta CPP and Fe Gluc perfused rats in both control and Fe-deficient animals. PAO decreased uptake, mucosal storage, and net absorption of Fe-beta CPP but not of Fe Gluc. At the end of the experiment Fe serum levels were increased only in Fe Gluc animals. These results confirm the improved bioavailability of beta CPP bound Fe. They suggest that at least part of its absorption can occur by a different pathway than usual Fe salts. Fe-beta CPP can be taken up by endocytosis and absorbed bound to amino acids or peptides.

Dose-response study of metoclopramide in gastroesophageal reflux in infancy.

Twenty-four infants, 1 to 18 months-old, who were referred to four centers for suspected gastroesophageal reflux and whose esophageal pH after a standard formula meal given at 9 to 10 am (Ho-day 1) fulfilled the criterion of being < 4 for more than 5% of the time between H1 and H6, entered a double-blind placebo-controlled dose-response trial of metoclopramide (M). Twenty-four hours later (day 2), patients were randomly assigned to receive either placebo or a single 0.1, 0.2, or 0.4 mg/kg dose of metoclopramide, 30 min before the formula meal (n = 6/group) and the procedure was repeated. Metoclopramide plasma concentration was measured 1 h after dosing (C1h). On day 1, the time during which the esophageal pH was < 4 (time pH < 4), and five other parameters, were not significantly different in the treatment groups. On day 2, time pH < 4 (m(SD)) decreased from 33(13) to 30(33), 39(27), to 36(47), 42(15) to 18(13) and 48(25) to 31(46) min in the placebo, 0.1, 0.2, and 0.4 mg/kg metoclopramide groups, respectively. Possibly due to the large interindividual variability, no significant differences in parameters were observed between the different groups. None of the parameters correlated with the metoclopramide dose. Time pH < 4 expressed as the difference between day 1 and day 2, relative to day 1, decreased significantly as a function of C1h. No side effects were observed. A similar study should be performed after repeated dosing regimen.

Zinc and iron status and growth in healthy infants.

OBJECTIVE: To elucidate the relationships between growth and zinc and iron status in normal infants. STUDY DESIGN: Growth of normal infants (less than 3 y old: n = 66) was prospectively assessed with a mean delay of 24+/-6 weeks between measurements; subjects were free from illness and presented with a normal growth. Growth was compared to serum zinc (s-zinc), IGF-1 and iron status. SETTING: Teaching hospital of Caen. RESULTS: No relation was found between linear or weight growth and s-zinc; when taking into account the effect of age, linear growth was significantly associated with ferritin (P<0.001); weight gain was significantly correlated with IGF-1 (P = 0.034) and ferritin (P = 0.008). No relationship was found between s-zinc and iron status. CONCLUSIONS: In normal infants iron status, more than serum zinc, seems to be correlated with growth.

Relationship between bone mineralization and aluminium in the healthy infant.

OBJECTIVE: This prospective study was designed to assess the relationship between variations of serum Aluminium levels and bone mineralization, which is one of its target tissues, in healthy premature (PT) and fullterm (FT) infants. STUDY DESIGN: Lumbar spine bone mineral density (BMD) and content (BMC) studied by dual energy X-ray absorptiometry were compared to serum aluminium (S-Al), Ca (S-Ca), P (S-P), osteocalcin, alkaline phosphatase activity (S-AP), and 25 OH Vitamin D (25 OH D) by simple and multiple regressions in healthy PT (n = 44) following their hospital discharge and FT (n = 82). PT (gestational age at birth (mean +/- 1 s.d.) 32 +/- 2 weeks) and FT were 43 +/- 39 and 36 +/- 32 weeks old respectively. RESULTS: In PT multiple stepwise regression analysis including gestational age at birth, postconceptional age and postnatal age displayed only a significant correlation between BMD or BMC and postnatal age and a negative one with S-Al. In FT correlations were found between BMD or BMC and age and S-Ca. CONCLUSIONS: In PT, variations in blood Al are associated with developmental delays. Care should be taken to lessen Al levels, even in healthy PT babies.

Effects of preterm infant formula supplementation with alpha-linolenic acid with a linoleate/alpha-linolenate ratio of 6: a multicentric study.

OBJECTIVE: To investigate the effects of a milk formula supplemented with a alpha-linolenic acid (ALA) (18:2 n-6/18:3 n-3 ratio near 6/1) on plasma and red blood cell (RBC) fatty acids (FAs) in premature infants and compare with a non supplemented formula (18:2 n-6/18:3 n-3 = 22/1). DESIGN AND SUBJECTS: Infants of mothers who elected not to breast-feed were randomly assigned to either a high alpha linolenic formula (HLF: n = 31) group or a low alpha-linolenic formula (LLF: n = 32) control group. Infants fed human milk (HM: n = 25) were enrolled concurrently as a reference group. Anthropometric and biological measurements were made after two days (D2) and 15 d (D15) of enteral feeding and at the 37th week (W37) of postconceptual age. In HLF, the 18:3 n-3 content was 1.95% of total FAs (0.77% of total energy) and the 18:2 n-6/18:3 n-3 ratio was near 6/1. In LLF, the 18:3 n-3 content was 0.55% of total FAs (0.22% of total energy) and the 18:2 n-6/18:3 n-3 ratio was 22/1. RESULTS: ALA supplementation had minimal effect on the n-6 series, did not alter the anthropometric data and confirmed the conversion of ALA into docosahexaenoic acid (DHA). Throughout the study, it maintained, the RBC membrane DHA values within the confidence interval of those obtained in the HM group. Such was not the case with LLF CONCLUSION: alpha-linolenic acid supplementation (from Rapeseed oil and in a 18:2 n-6/18:3 n-3 ratio = 6) in premature infant formula can contribute efficiently to the maintenance of the n-3 status in the premature newborns.

A cross-sectional study of plasma and urinary aluminum levels in term and preterm infants.

High aluminum levels have been reported in sick and intravenously fed premature infants; however, aluminum is a ubiquitous pollutant of food. This study compares the usual aluminum levels of healthy newborns from birth to the third month of life with those of enterally fed premature infants free of renal failure. Plasma and urine concentrations were determined 66 times in full-term newborns (n = 58), 56 times in a group of preterm infants whose gestational age at birth was 28 to 32 weeks (n = 36) and 54 times in another group of preterm infants whose gestational age at birth was 33 to 36 weeks (n = 50). Daily aluminum intakes (+/- SE) of the full-term infants and the two groups of preterm infants were 0.42 +/- 0.05, 0.64 +/- 0.03, and 0.52 +/- 0.03 mumol/kg per day, respectively (p = .05). Plasma aluminum levels were 0.29 +/- 0.05, 0.49 +/- 0.06, and 0.39 +/- 0.05 mumol/L (p = .007); urine excretion levels were 0.80 +/- 0.12, 0.77 +/- 0.21, and 0.78 +/- 0.2 mumol of aluminum/mmol of creatinine (p value not significant). Although the metabolic consequences of the high aluminum intakes and blood levels we have observed in very low birth weight infants remain to be assessed, these results suggest that more attention should be paid to the aluminum status and intake of healthy premature babies.

Plasma and erythrocyte essential fatty acids during total parenteral nutrition in infants: effects of a cutaneous supply.

In order to prevent essential fatty acid (EFA) deficiency induced by fat-free total parenteral nutrition (TPN), 10 infants on TPN were rubbed three times daily for 20 days using oenethera oil (80% EFA). Total EFA amount provided cutaneously was 1900 mg/kg/d. Plasma and red blood cells phospholipids were determined on days 1 and 20 in these 10 treated and six untreated infants on TPN and compared with those of normal control infants. On day 1, plasma nonessential FA including 20:3 n-9(p less than 0.01) were increased in both TPN groups while 18:2 n-6 and 18:3 n-3 (p less than 0.001 and p less than 0.01) were decreased. On the 20th day, EFA deficiency had worsened with a decrease in plasma level of 20:4 n-6 (p less than 0.02) and a higher than normal triene/tetraene ratio : 3.4 +/- 1.1 and 2.3 +/- 0.6 vs 0.1 +/- 0.1 (p less than 0.02). As for red blood cells phospholipids, 16:0 was increased and 18:2 n-6 and 20:3 n-6 were decreased (p less than 0.05) on day 1. On day 20, these FA were more abnormal while 20:3 n-9 became significantly increased (p less than 0.05). No difference was observed between the TPN groups at any time. These results show that cutaneous application of large amounts of EFA-rich oil is unable to prevent or cure TPN induced EFA deficiency.

Hematologic disorders following prolonged use of intravenous fat emulsions in children.

Abnormalities in hematologic parameters, associated with prolonged utilization of intravenous fat emulsion (IVFE), were observed in seven children on long-term cyclic total parenteral nutrition (TPN). All patients were receiving IVFE (Intralipid 20%) 1 to 2 g/kg/24 hr as part of TPN, during 3 to 18 months. Recurrent thrombocytopenia occurred in all seven patients. Platelet lifespan, as measured with 111 Indium was reduced. Sea-blue histiocytes containing granulations and hemophagocytosis were seen on bone marrow smears. Scans taken after injection of autologous erythrocytes labeled with technetium-99 showed bone marrow sequestration of these cells. Taken together, this constellation of hematologic abnormalities suggests that long-term IVFE administration induces hyperactivation of the monocyte-macrophage system.

Maturation of peripheral nerves in preterm infants: proprioceptive and motor nerve conductions of tibial nerve.

Premature birth induces a profound change in the environmental factors affecting nerve maturation. The proprioceptive sensory and motor nerve conduction velocities (NCV) of the posterior tibial nerve, which reflect peripheral nerve maturation, have been measured in 3 groups of newborns. Two groups of premature (PT) babies, studied when they reached the expected date of birth (group I, gestational age (GA) at birth, 28-31 weeks, n = 8; group II, GA at birth, 32-35 weeks, n = 6) were compared to 9 normal full-term (FT) newborns. As previously shown, the motor NCV of PT babies at a post-conceptional age close to term is similar to that of FT newborns: group I, 22.70 +/- 2.95 m/s (mean +/- SD); group II, 25.90 +/- 4.61 m/s; FT, 25.48 +/- 4.09 m/s. The proprioceptive sensory NCV was significantly lower in group I (21.59 +/- 4.39 m/s) than in group II (31.89 +/- 4.15 m/s) and FT newborns (32.22 +/- 6.56 m/s) (p less than 0.01). Such a delay in maturation could be responsible for the subtle clinical dysfunctions often observed in PT babies.

Iron tissue storage and hemoglobin levels of deficient rats repleted with iron bound to the caseinophosphopeptide 1-25 of beta-casein.

Caseinophosphopeptides (CPP) issued from enzyme digestion of caseins bind cations and keep them soluble in the digestive tract. They could be used as ligands to improve iron (Fe) bioavailability. Fe-deficient young rats were repleted with Fe (40 or 200 mg/kg of diet) bound either to the beta-CN (1-25) of beta-casein or to whole beta-casein or as FeSO(4). A control pair-fed group was given 200 mg of Fe (FeSO(4))/kg of diet for 6 weeks. After repletion, hemoglobin concentration of the control group was reached only by the ) animals fed 200 mg of Fe/kg; beta-CN (1-25) bound Fe (40 and 200 mg) produced higher Fe liver and spleen stores than FeSO(4). Binding Fe to the whole, nonhydrolyzed beta-casein gave results intermediate between the other experimental groups. Binding Fe to phosphoserine residues of low molecular weight CPP improved its ability to cure anemia and to restore iron tissue stores, as compared to Fe bound to the whole casein and to inorganic salts.