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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., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

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.

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.

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.