Le contrôle de qualité externe en Biologie de la Reproduction de 1992 à 1996

Clinical efficiency of laboratory results in spermiology needs to have reliable data, and a quality assurance in their determinations. This could be done by creating an External Quality Control, each laboratory analyzing the same specimens. We transferred in spermiology methodologies currently used in Quality Control in Biochemistry and results presented here referred to the 1992–1996 period. Volountary participation of 37 laboratories who recieved two slides issuing from the same ejaculate. Coloration was made with that used in their own laboratory. Two parameters were specially studied: the total normal sperm count and the degree of teratospermia by evaluation of the Multiple Abnormalities Index (MAI). An area around the target value of 15% is actually retained and results in terms of precision and accuracy are interpreted with the Youden’s diagram. For the total normal sperm count, the disperson remains important during the 4 years (about 30 and 40%) with a poor percentage of laboratories in the area of accuracy. For the MAI, results are better as soon as the dispersion falls from 25 to 15% during the same time and the percentage of laboratories in the accuracy area rises from 10% to 68%. After four years of external quality control, such a protocol is very useful. But the quality results of some parameters must be more extensively explored to reduce interlaboratory dispersion and to improve the clinical efficiency of laboratory data in the spermiology approach.     

Mise en œuvre du contrôle de qualité en médecine nucléaire

Like in many nuclear medicine centers, the AFSSAPS decision of November 25, 2008, has slightly changed our habits. The centers with medical physicist already made most of these controls, and this concept was not new for them. But what about the other centers? Sometimes, measures were made as expected, other times the manufacturers were expected to do them during the maintenance time, often nothing was formalized, and even in some cases nothing was done. Our experience in quality control in nuclear medicine is relatively recent, but we find interesting to raise some issues, including the duration for all these controls, the possible delegations, the means necessary to build them and difficulties in applying these controls.     

Répartiteur de dose des médicaments radiopharmaceutiques : contrôle qualité sur deux sites hospitaliers et comparaison avec la législation en vigueur en France

An increasing number of nuclear medicine departments are equipped with automated measurement systems for the preparation of radiopharmaceuticals, with the main aim of minimising technician's irradiation. However, the automatic measurement of the patient activity differs from the manual measurement in material and method. In this context, the objective of the present study was to test the performances of one of these systems, the Unidose by TRASIS^®, in two newly equipped hospitals. The particularity of these systems is they are made up of two dose calibrators: the entrance calibrator (well chamber) and the exit calibrator (probe). Controls were performed on both of these dose calibrators. The results obtained, as well as the methodology employed, were then compared with the regulatory requirements in France. The results found are coherent between the two sites and have highlighted several non-conformities compared to the current regulations, part of which concerning the carpule dose calibrator, which is actually a probe. These results raise the question of a suitable regulation for the new automated measurement systems in nuclear medicine.     

Homogénéité ou hétérogénéité dans le métal des dépôts de l’Âge du Bronze : estimations sur leur formation à partir des isotopes du plomb

Lead isotope analysis was applied to three representative Late Bronze Age hoards from the Iberian Peninsula, for all of which compositional analyses are available. Unpublished isotopic evidence from the cave of Muricecs (Lleida) and the settlement of Las Lunas (Toledo) are compared to the published results for weapons from the Ría de Huelva, one of the most important Late Bronze Age hoards from Western Europe. Lead isotope analysis can tell us the sources of the metal used to make the artifacts in each hoard. The limited number of geologic reference points makes it difficult to determine all of the ore sources, but the analyses do give us evidence about the degree of homogeneity of the metal in the artifacts. As a result, one can separate metallic composition from artifact typology and thereby evaluate how the hoards were formed and what their functions were. Elemental analysis is unsuitable for this purpose because Late Bronze Age metals from Iberia are very homogenous and have few impurities.     

L'excursion dans le Nord et l'Ouest de la France de la société internationale de phytosociologie

Sans résumé     

Les mécanismes de contrôle de la méiose dans la lignée germinale mâle

In 1883, it was discovered that whereas the fertilized egg of a particular worm (Parascaris Equorum) contains four chromosomes, the nucleus at the egg and that of the sperm each contains only two chromosomes. This finding implied that germ cells must be formed by a special kind of nuclear division in which the chromosome complement is precisely halved. This type of division is called meiosis. Meiosis and mitosis share many regulatory elements. Among them, are the cyclindependent kinases (CDK) and the cyclins which control all transitions of the cell cycle. The activity of the CDKs is regulated by their association to specific cyclines and by phosphorylation/dephosphorylation reactions. Moreover, recent reports reveal the existence of a variety of small proteins which bind to and modulate G1/S CDK-cyclin complexes: the CKI. Two more proteins appear of great importance in regulating the cell cycle: Rb and p53. The central role of MPF (maturation producing factor=M-phase promoting factor) has been established, mostly by studies conducted on either invertebrates oocytes and eggs that resume the meiotic division. MPF is the cyclin B-p34cdc2 kinase. As for the cytostatic factor (CSF), it is reasonably certain that it is, in part or entirely, MOS. The cell cycle signalling mechanisms in oocytes include cAMP, Ca⁺⁺ and the agonists of PKC. Much less informations on the control of meiosis in spermatogenesis are available. Indeed, it is difficult to get rather high number of germ cells at some precise steps of their maturation and there is a lack of culture system allowingin vitro germ cell differentiation. However, most of the genes involved in the regulation of the cell cycle are expressed in the testis (c-mos, cyclins, CDK, cdc 25…). Their expression has striking cellular, lineage and developmental specificity. It has also been shown that FSH, interleukin-1a, and MIP-1a enhance stagespecific DNA synthesis in rat seminiferous tubule segments, while interleukin-6 decreases it. In our laboratory, we have settled recently two cell culture systems allowing the expression of germ cell specific genes for 2 to 3 weeks. This should help to study more easily the genetic control of meiosis during spermatogenesis and to understand better which growth factors and/or cytokines are really important for the regulation of this process.