[Prevalence of vitamin D deficiency in children aged 5-10 years in western Brittany]. / Prévalence du déficit en vitamine D chez les enfants âgés de 5 à 10ans en Bretagne Occidentale.

UNLABELLED: French guidelines do not recommend systematic supplementation of vitamin D in children aged 5-10 years old owing to the lack of data on vitamin D status in this age group. Our objective was to assess the prevalence of vitamin D deficiency in these children. METHODOLOGY: Single-center, prospective, epidemiological study including 358 children aged 0-15 years. The endpoint was the concentration of vitamin D. RESULTS: In all, 316 children were divided into four groups according to age: 0-18 months (n=113); 18 months to 5 years (n=103); 5-10 years (n=62); and 10-15 years (n=38). The median concentration of vitamin D decreased with age (P<0.001): 90.2 nmol/L in the group aged 0-18 months; 56.7 nmol/L in the group aged 18 months to 5 years; 49.05 nmol/L in the group aged 5-10 years; and 42.45 nmol/L in the group aged 10-15 years. This corresponds to an increase in the prevalence of vitamin D deficiency in children aged 5-10 years (51.6% vs. 8.8% in the group aged 0-18 months, P<0.001). For children aged 5-10 years, the prevalence of deficiency was greater in the non-supplementation group (75%) compared with the supplementation group (13%; P<0.001). CONCLUSION: This study demonstrates the high prevalence of vitamin D deficiency in children aged 5-10 years and the relationship between supplementation and vitamin D status. It provides an argument in favor of supplementation in children aged 5-10 years in this region and a reconsideration of the French recommendations.

[Down syndrome maternal serum screening: results' comments recommended by accredited biologists]. / Dépistage de la trisomie 21 par les marqueurs sériques maternels : justification des commentaires appliqués par les biologistes.

Down syndrome maternal serum screening is largely used in France. The aim of this article is to specify and to explain the different comments applied on the reports in order to optimize the management of the patient. These comments represent the consensus of the study group of the biologist accredited for Down syndrome maternal serum screening.

Prevalence of CFTR mutations in hypertrypsinaemia detected through neonatal screening for cystic fibrosis.

Nowadays, most of the neonatal screening programs for cystic fibrosis (CF) combine the assay of immunoreactive trypsinogen (IRT) with the analysis of the most common mutations of the CFTR gene. The efficiency of this strategy is now well established, but the identification of heterozygotes among neonates with increased IRT is perceived as a drawback. We proposed to assess the heterozygosity frequency among the children with hypertrypsinaemia detected through the CF screening program implemented in Brittany (France) 10 years ago, to describe the CFTR mutations detected in them and to determine the frequency of the IVS8-5T variant. The molecular analysis relies, in our protocol, on the systematic analysis of three exons of the gene (7-10-11). A total of 160,019 babies were screened for CF in western Brittany between 1992 and 1998. Of the 1964 newborns with increased IRT (1.2%), 60 were CF and 213 were carriers. Heterozygosity frequency was 12.8%), i.e. 3 times greater than in the general population (3.9%; p < 10(-6)), Variability of mutations detected in carriers was greater than in CF children (21 mutations versus 10) and a high proportion of mild mutations or variants (A349V, R297Q, R347H, V317A, G544S, R553G, etc) was observed in carriers. The allelic frequency of the 5T (5.6%) was not significantly increased in this cohort. This study is consistent with previous ones in finding a significantly higher rate of heterozygotes than expected among neonates with hypertrypsinaemia. The strategy of screening used here allows to highlight the variability of mutations detected in heterozygotes and to show that severe mutations, as well as mild mutations, have been observed in neonates with hypertrypsinaemia. If there is no doubt that neonatal hypertrypsinaemia is associated with an elevated frequency of carriers, the underlying mechanisms remain obscure.

[Metallic trace elements--A1, Cd, Cu, Fe--in solutions of 111InCl3: determination by flameless atomic absorption and results in 111In-radiolabeling of monoclonal antibodies]. / Traces métalliques--A1, Cd, Cu, Fe--dans les solutions de 111InCl3: dosage par absorption atomique sans flamme et conséquences pour le radiomarquage par 111In des anticorps monoclonaux.

Determination of trace elements in 111InCl3 solution have been carried out by flameless atomic absorption spectrometry. Five successive batches from three European companies have been analysed. The means of measured values range from 4560 to 6930 micrograms L-1 for aluminium, 131 to 874 for cadmium, 49 to 300 for copper, 387 to 698 for iron. Using two molar ration indexes, trivalent metallic traces have been compared to theoretical 111In content. The trace elements largely exceed radioactive material. As Fe and In have similar chemical properties, it results in low specific activity of radioactive complex when labeling monoclonal antibodies by 111In. Using a mathematical model, a detrimental effect of Fe trace levels has been studied.

[Rapid analysis of transferrin-iron complexes by isoelectric focusing and radioactive densitometry on gel]. / Analyse rapide des complexes transferrine-fer par isoélectrofocalisation et densitométrie radioactive sur le gel.

The analysis of the molecular forms of transferrin-iron complexes with 59Fe, was carried out using an isoelectric focusing method on commercially available polyacrylamide plates (PAG plates pH = 4-6,5, LKB). Depending upon the saturation degree of proteins with iron, apotransferrin (pI = 6,1), transferrin-Fe3+ (pI = 5,8), transferrin-2 Fe3+ (a) (pI = 5,5) and transferrin-2 Fe3+ (b) (pI = 5,3) were put forward. When the protein was saturated with iron, a double band was observed which was assigned to the microheterogeneity of the protein and depends upon the sialic content. The quantitative analysis was carried out by studying 59Fe radioactivity distribution directly on the plate. As a control, a specific staining of proteins was achieved. The interpretation of the results is difficult if such a method is used, as some bands are not attributed. Through an unspecific staining, the UV-visible densitometry is not satisfactory enough. The proposed method allows a fast analysis of transferrin-metal complexes labeled with radioactive metals. Such a method would be adaptable to the study of other complexes as transferrin-67Ga, transferrin 111In in order to determine the binding site of metal on the protein and its metal content.

[Serological profile in so-called seronegative rheumatoid arthritis]. / Profil sérologique des polyarthrites rhumatoïdes dites séronégatives.

89 cases of sero-negative rheumatoid arthritis (RA) were compared to 127 cases of sero-positive RA. Anti-perinuclear and anti-keratin antibodies were detected less frequently in the first group (51 vs 67% and 28 vs 33%, respectively), while the inverse was found for anti-nuclear antibodies (28 vs 24%). "Light" rheumatoid factors (RF)--IgG, IgM, IgE, IgA and IgD--were detected in 23.6, 21.3, 17.5, 11.3 and 0 per cent of cases of sero-negative R.A. The evolutive state of these cases was less severe. RF agglutinins were detected in 5 out of 12 samples of synovial fluid tested in cases of sero-negative RA.

Clinical relevance of antikeratin antibodies in rheumatoid arthritis.

Antikeratin antibodies (AKA) were found in 38 out of 96 patients with rheumatoid arthritis (RA); they appeared to be quite characteristic to this disease. There was a very low incidence of AKA positivity in the control groups, i.e., 1 out of 62 healthy subjects and 4 out of 158 other patients. With regard to the sensitivity of the test as a diagnostic tool, AKA was found to be weaker than the rheumatoid factor (RF) and the antiperinuclear factor (APF), whereas the specificity was much better than APF and RF. A clear correlation was shown between the titres of AKA and APF (p less than 0.001) and also between AKA levels and inflammation (p less than 0.02).