The aims of the present position paper by the Committee on Nutrition of the French Society of Paediatrics were to summarize the recently published data on vitamin D in infants, children and ...adolescents, i.e., on metabolism, physiological effects, and requirements and to make recommendations on supplementation after careful review of the evidence. Scientific evidence indicates that calcium and vitamin D play key roles in bone health. The current evidence, limited to observational studies, however, does not support other benefits for vitamin D. More targeted research should continue, especially interventional studies. In the absence of any underlying risk of vitamin D deficiency, the recommendations are as follows: pregnant women: a single dose of 80,000 to 100,000IU at the beginning of the 7th month of pregnancy; breastfed infants: 1000 to 1200IU/day; children less than 18 months of age, receiving milk supplemented with vitamin D: an additional daily dose of 600 to 800IU; children less than 18 months of age receiving milk not supplemented with vitamin D: daily dose of 1000 to 1200IU; children from 18 months to 5 years of age: 2 doses of 80,000 to 100,000IU every winter (November and February). In the presence of an underlying risk of vitamin D deficiency (dark skin; lack of exposure of the skin to ultraviolet B UVB radiation from sunshine in summer; skin disease responsible for decreased exposure of the skin to UVB radiation from sunshine in summer; wearing skin-covering clothes in summer; intestinal malabsorption or maldigestion; cholestasis; renal insufficiency; nephrotic syndrome; drugs rifampicin; antiepileptic treatment: phenobarbital, phenytoin; obesity; vegan diet), it may be justified to start vitamin D supplementation in winter in children 5 to 10 years of age as well as to maintain supplementation of vitamin D every 3 months all year long in children 1 to 10 years of age and in adolescents. In some pathological conditions, doses of vitamin D can be increased. If necessary, the determination of 25(OH) vitamin D serum concentration will help determine the level of vitamin D supplementation.
L’objectif de cette mise au point du Comité de nutrition de la Société française de pédiatrie est de résumer les connaissances récemment acquises chez l’enfant et l’adolescent et de proposer des recommandations de prescription. En l’absence de risque particulier, les recommandations sont les suivantes : femme enceinte : dose de charge unique de 80 000 à 100 000UI au début du 7emois de grossesse ; nourrisson allaité : 1000 à 1200UI/j ; enfant moins de 18 mois, recevant un lait enrichi en vitamine D : complément de 600 à 800UI/j ; enfant moins de 18 mois recevant un lait de vache non enrichi en vitamine D : 1000 à 1200 UI/j ; enfant de 18 mois à 5 ans et adolescent de 10 à 18ans : 2 doses de charge trimestrielle de 80 000 à 100 000 UI en hiver (novembre et février). En présence d’un risque particulier (forte pigmentation cutanée ; absence d’exposition au soleil estival ; affection dermatologique empêchant cette exposition ; port de vêtements très couvrants en période estivale ; malabsorption digestive, cholestase, insuffisance rénale, syndrome néphrotique ; certains traitements rifampicine ; traitement antiépileptique: phénobarbital, phénytoine ; obésité ; régime aberrant végétalisme), il peut être justifié de poursuivre la supplémentation toute l’année chez l’enfant de 1 à 5ans et chez l’adolescent, et de la maintenir entre 5 et 10ans. Dans certaines situations pathologiques, les doses peuvent être augmentées. Si nécessaire, le dosage de la 25(OH) vitamine D guidera la prescription de vitamine D.
Carnitine palmitoyltransferase 2 (CPT2) deficiency is a rare mitochondrial fatty acid oxidation (FAO) disorder characterized by myalgia, exercise intolerance, and rhabdomyolysis. We evaluate the ...efficacy of bezafibrate (BZ), a hypolipidemic drug, as a treatment for this form of CPT2 deficiency. A pilot trial was conducted with BZ in six patients for 6 months. There was a follow‐up period of 3 years. The oxidation rates of the long‐chain fatty acid derivative palmitoyl‐CoA, measured in the mitochondria of the patients' muscles, were markedly lower than normal before treatment and increased significantly (+39 to +206% P = 0.028) in all patients after BZ treatment. The evaluation of the therapeutic effects by the patients themselves (using the Short Form Health Survey (SF‐36)), as well as by the physicians, indicated an improvement in the condition of the patients; there was an increase in physical activity and a decline in muscular pain. The results suggest that BZ has a therapeutic effect in the muscular form of CPT2 deficiency.
Clinical Pharmacology & Therapeutics (2010) 88 1, 101–108. doi: 10.1038/clpt.2010.55
A novel experimental technique based on in situ AFM monitoring of the mechanisms of damage and the strain fields associated to the slow steady-state propagation of a fracture in glassy polymers is ...presented. This micron-scale investigation is complemented by optical measurements of the sample deformation up to the millimetric macroscopic scale of the sample in order to assess the proper crack driving conditions. These multi-scale observations provide important insights towards the modeling of the fracture toughness of glassy polymers and its relationship with the macromolecular structure and non-linear rheological properties. This novel technique is first tested on a standard PMMA thermoplastic in order to both evaluate its performance and the richness of this new kind of observations. Although the fracture propagation in PMMA is well known to proceed through crazing in the bulk of the samples, our observations provide a clear description and quantitative evaluation of a change of fracture mechanism towards shear yielding fracture accompanied by local necking close to the free surface of the sample, which can be explained by the local change of stress triaxiality. Moreover, this primary surface necking mechanism is shown to be accompanied by a network of secondary grooves that can be related to surface crazes propagating towards the interior of the sample. This overall scenario is validated by post-mortem fractographic investigations by scanning electron microscopy.
BACKGROUND: Sperm donors represent an appropriate population for evaluating the frequency of chromosomal abnormalities in phenotypically normal and fertile adult males. METHODS: A large multicentric ...retrospective study was made within the French CECOS (Centre d’Etude et de Conservation des ufs et du Sperme) for collecting cytogenetic, biological and familial data in sperm donors over a 25-year period. RESULTS: As a whole, 10 202 karyotypes have been recorded. Thirty-eight karyotype aberrations (0.37%) have been diagnosed including 21 balanced chromosomal rearrangements (0.2%). These results are in agreement with those obtained in most large-scale studies performed in unselected newborns. Semen parameters were known for all men carrying an abnormal karyotype and showed normal sperm counts, suggesting that these types of chromosomal aberrations have no or poor consequences on spermatogenesis. Available familial data did not reveal any particular history of malformations, mental retardation or fetal losses. CONCLUSION: This study is the first large-scale cytogenetic study made in normal and fertile males and shows that the frequency of chromosomal aberrations is not influenced by a previous normal fertility or by an uneventful familial history when compared to that found at birth.
The diagnosis of cows' milk protein allergy (CMPA) requires first the suspicion of diagnosis based on symptoms described in the medical history, and, second, the elimination of cows' milk proteins ...(CMP) from the infant's diet. Without such rigorous analysis, the elimination of CMP is unjustified, and sometimes harmful. The elimination diet should be strictly followed, at least until 9-12 months of age. If the child is not breast fed or the mother cannot or no longer wishes to breast feed, the first choice is an extensively hydrolysed formula (eHF) of CMP, the efficacy of which has been demonstrated by scientifically sound studies. If it is not tolerated, an amino acid-based formula is warranted. A rice protein-based eHF can be an alternative to a CMP-based eHF. Soya protein-based infant formulae are also a suitable alternative for infants >6 months, after establishing tolerance to soya protein by clinical challenge. CMPA usually resolves during the first 2-3 years. However, the age of recovery varies depending on the child and the type of CMPA, especially whether it is IgE-mediated or not, with the former being more persistent. Once the child reaches the age of 9-12 months, an oral food challenge is carried out in the hospital ward to assess the development of tolerance and, if possible, to allow for the continued reintroduction of CMP at home. Some children with CMPA will tolerate only a limited daily amount of CMP. The current therapeutic options are designed to accelerate the acquisition of tolerance thereof, which seems to be facilitated by repeated exposure to CMP.
Cobalt (Co) is an essential trace element well known as a constituent of vitamin B
12, but different compounds of Co are also described as highly toxic and/or radiotoxic for individuals or the ...environment. In nuclear power plants,
58Co and
60Co are radioactive isotopes of cobalt present as activation products of stable Co and Ni used in alloys. Skin exposure is a current occupational risk in the hard metal and nuclear industries. As biochemical and molecular cobalt-induced toxicological mechanisms are not fully identified, we investigated cobalt toxicity in a model human keratinocyte cell line, HaCaT. In this study, we propose a model to determine the
in vitro chemical impact on cell viability of a soluble form of cobalt (CoCl
2) with or without γ-ray doses to mimic contamination by
60Co, to elucidate the mechanisms of cobalt intracellular chemical and radiological toxicity.
Intracellular cobalt concentration was determined after HaCaT cell contamination and chemical toxicity was evaluated in terms of cellular viability and clonogenic survival. We investigated damage to DNA in HaCaT cells by combined treatment with chemical cobalt and a moderate γ-ray dose. Additive effects of cobalt and irradiation were demonstrated. The underlying mechanism of cobalt toxicity is not clearly established, but our results seem to indicate that the toxicity of Co(II) and of irradiation arises from production of reactive oxygen species.
To date, there is significant controversy as to the survival of yogurt bacteria (namely,
Streptococcus thermophilus and
Lactobacillus delbrueckii subsp.
bulgaricus) after passage through the human ...gastrointestinal tract. Survival of both bacterial species in human feces was investigated by culture on selective media. Out of 39 samples recovered from 13 healthy subjects over a 12-day period of fresh yogurt intake, 32 and 37 samples contained viable
S. thermophilus (median value of 6.3
×
10
4
CFU
g
−1 of feces) and
L. delbrueckii (median value of 7.2
×
10
4
CFU
g
−1 of feces), respectively. The results of the present study indicate that substantial numbers of yogurt bacteria can survive human gastrointestinal transit.
Context.Optical long-baseline interferometry is moving a crucial step forward with the advent of general-user scientific instruments that equip large aperture and hectometric baseline facilities, ...such as the Very Large Telescope Interferometer (VLTI). Aims.AMBER is one of the VLTI instruments that combines up to three beams with low, moderate and high spectral resolutions in order to provide milli-arcsecond spatial resolution for compact astrophysical sources in the near-infrared wavelength domain. Its main specifications are based on three key programs on young stellar objects, active galactic nuclei central regions, masses, and spectra of hot extra-solar planets. Methods.These key science goals led to scientific specifications, which were used to propose and then validate the instrument concept. AMBER uses single-mode fibers to filter the entrance signal and to reach highly accurate, multiaxial three-beam combination, yielding three baselines and a closure phase, three spectral dispersive elements, and specific self-calibration procedures. Results.The AMBER measurements yield spectrally dispersed calibrated visibilities, color-differential complex visibilities, and a closure phase allows astronomers to contemplate rudimentary imaging and highly accurate visibility and phase differential measurements. AMBER was installed in 2004 at the Paranal Observatory. We describe here the present implementation of the instrument in the configuration with which the astronomical community can access it. Conclusions.After two years of commissioning tests and preliminary observations, AMBER has produced its first refereed publications, allowing assessment of its scientific potential.
Pericentric inversions are structural chromosomal abnormalities resulting from two breaks, one on either side of the centromere, within the same chromosome, followed by 180° rotation and reunion of ...the inverted segment. They can perturb spermatogenesis and lead to the production of unbalanced gametes through the formation of an inversion loop. METHODS: We report here the analysis of the meiotic segregation in spermatozoa from six pericentric inversion carriers by multicolour fluorescence in-situ hybridization (FISH) and review the literature. RESULTS: The frequencies of the non-recombinant products (inversion or normal chromosomes) were 80% for the inv(20), 91.41% for the inv(12), 99.43% for the inv(2), 68.12% for the inv(1), 97% for the inv(8)(p12q21) and 60.94% for the inv(8)(p12q24.1). The meiotic segregation of 20 pericentric inversions (including ours) is now available. The frequency of unbalanced spermatozoa varies from 0 to 37.85%. The probability of a crossover within the inverted segment is affected by the chromosome and region involved, the length of the inverted segment and the location of the breakpoints. CONCLUSIONS: No recombinant chromosomes were produced when the inverted segment involved <30% of the chromosome length (independent of the size of the inverted segment). Between 30 and 50%, few recombinant chromosomes were produced, inducing a slightly increased risk of aneusomy of recombination in the offspring. The risk of aneusomy became very important when the inverted segment was >50% of the chromosome length. Studies on spermatozoa from inversion carriers help in the comprehension of the mechanisms of meiotic segregation. They should be integrated in the genetic exploration of the infertile men to give them a personalized risk assessment of unbalanced spermatozoa.
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