Le bilan sénologique : indication et interprétation

Breast cancer is the most common cancer in women in France. The aim of this article is to describe modalities of detection and to explain how the images interpretation and the review are realized.     

Anticorps anti-spermatozoïdes: techniques de dépistage et interprétation des résultats

Since the first publication on the detection of sperm-agglutinating antibodies in infertile men, multiple assays have been described. The most useful tests are able to detect antibodies bound to the sperm membrane of motile spermatozoa. The immunobeads test (IBT) is considered to be the most advantageous in terms of its sensitivity, the low incidence of false-positive results, and its ability to localize antibodies of different immunoglobulin classes on the sperm surface. The IBT assay can be used in parallel with the mixed antiglobulin reaction (MAR), to detect sperm-associated antibodies in the ejaculates of infertile men, the most rational way to test for antisperm antibodies (ASA) in males. In view of the high level of agreement between the two assays, MAR, the easier of the two, may be used as a first step in the detection of these antibodies. A positive MAR must be confirmed by IBT, as this assay is more specific for the detection of IgA antibodies. The clinical significance of sperm-associated antibodies is usually established according to the proportion of motile spermatozoa coated with immunobeads, its class and its localization on the sperm surface. However, binding of immunobeads does not provide any information about the antigens against which the antibodies are directed. As the functional effects of sperm-associated antibodies may vary as a function of their antigenic specificities, other assays, using purified fertilization related antigens, are necessary to establish, for each individual, the specific impact of the antibodies on the fertilization process. The indirect IBT assay has recently become the most widely used test to detect the various classes of ASA in serum and cervical mucus of infertile women and in the serum and seminal fluid of infertile men, in combination with the direct assay described above. However, in most laboratories, it is performed with only one dilution of the biological fluid tested, usually a low dilution, so that antibody levels of no significance for fertility could be detected. This may explain a recente debate (Human Reprod, 1999) on the significance of ASA as a cause of infertility. At present, and in the absence of standardized assays able to identify the antigens involved in each individual immune reaction, antibody assays, as detected by the IBT assay, in the serum and/or genital secretions of infertile subjects might provide useful clinical guidance.     

Particularités méthodologiques et interprétation du dosage de thyroglobuline sérique

Thyroglobulin (Tg) is a large glycoprotein produced and excreted by thyrocytes exclusively. Thus, Tg is a central marker for the follow-up of differentiated thyroid cancer (DTC). This review presents recent analytical and related clinical advances in Tg assay. Indeed, recent advances in Tg assay challenge the previous use of the assay in the management of DCT. Indeed, a recent assay seems sensitive enough to be used to predict DTC differentiated recurrences without stimulation of thyrocytes by rhTSH. This improvement in analytical sensitivity is combined with international standardisation and reduced interferences by Tg autoantibodies. Such assays could reduce the cost of DCT follow-up by associating echography with a single assay, reducing the need of rhTSH stimulation to rare ambiguous cases.     

Faunes d'oiseaux du pléistocène de France: Systématique, évolution et adaptation,interprétation paléoclimatique

Statistical comparison between bird populations from Lower and Middle Pleistocene and present ones makes it possible to demonstrate evolutionnary shifts such as increase in size or, on the contrary, decrease in size in some lineages and to discover some species or subspecies already found in Central Europe, in layers of the same epoch. In some other lineages the observed variations seem to be regarded as possible adaptations to local geographical conditions.Moreover the study of the birds contributes richly to the reconstitution of climates and biotops. The percentage variations of «cold birds in a given site makes it possible to confirm climatic fluctuations already discovered by other methods of study.     

Actualités sur les dosages de parathormone : des difficultés analytiques à l’interprétation des résultats en clinique

Parathyroid hormone (PTH) is an 84-amino acid peptide hormone that is measured with difficulties. Firstly, the blood sample is currently performed on serum or EDTA plasma. The interassay variability according to the method requires the use of serum. Secondly, specificity depends on the method. The PTH intact assays were thought to bind only 1–84 PTH. At the present time, it is well-known that these assays cross-react with PTH fragments including 7–84 PTH. Third-generation assays without cross-reaction have been recently developed. At the present time, these assays have not shown any superior value than the second-generation assays in the treatment of renal osteodystrophy for which cut-off values of 150 and 300 ng/L have been reported by the K/DOKI. These values can be maintained if the method gives results similar to those obtained with the Allegro assay that was the reference method for K/DOKI recommendations. By contrast, we propose to use assay-specific decision limits for patients or to apply a correcting factor to the PTH values for the methods giving different results with the Allegro assay. Further recommendations from expert groups working for harmonization of different PTH tests should be considered.     

La radiation des Mammifères : phylogénie et innovations évolutives,progrès récents

The radiation of Mammals: recent advances concerning their phylogeny and evolutionary innovations. In the 3,5 billion years of the History of the Life, that of Mammals seems to us all the more brief that their future seems to have deceived in some million years, at the very beginning of the Cenozoic times. For their understanding, palaeontologists as well as molecularists try to build up the phylogenetic tree of the mammals. Here some of the reasons for the conflicts and controversies between both communities are analysed. Also the main evolutionary novelties as observed in Early Tertiary mammals are described. This catalogue shed light on this extraordinary event. To cite this article: J.-L. Hartenberger, C.R. Palevol 2 (2003).     

Distribution et activités des alcaloïdes défensifs des Coccinellidae

From a survey of 30 species and varieties of ladybugs the presence of alkaloids appears to be correlated with the existence of aposematic colour and not with being carnivorous or phytophagous. The alkaloids described until now all belong to the Coccinellini and are closely related, but other types of bases have been detected in some genera. The observed distributions are in agreement with the modern taxonomy of the family.Ladybug alkaloids constitute an effective defence against ants, Myrmica rubra, and quails, Coturnix coturnix, but all the beetles containing alkaloids do not possess the same degree of protection. Individual quail react differently towards moderately protected species.The bioassay used for the first isolation of coccinelin is described. The repulsive activities of aqueous solutions of coccinellin and convergin towards ants have been compared.     

Le modèle triadique des aspects neurobiologiques des comportements motivés à l’adolescence

Background

Risk-taking behavior is a major cause of morbidity and mortality in adolescence. In the context of decision theory and motivated (goal-directed) behavior, risk-taking reflects a pattern of decision-making that favors the selection of courses of action with uncertain and possibly harmful consequences. We present a triadic, neuroscience systems based model of adolescent decision-making.

Method

We review the functional role and neurodevelopmental findings of three key structures in the control of motivated behavior, i.e., amygdala, nucleus accumbens and medial/ventral prefrontal cortex. We adopt a cognitive neuroscience approach to motivated behavior that uses a temporal fragmentation of a generic motivated action. Predictions about the relative contributions of the triadic nodes to the three stages of a motivated action during adolescence are proposed.

Results

The propensity during adolescence for reward-novelty seeking in the face of uncertainty or potential harm might be explained by a strong reward system (nucleus accumbens), a weak harm avoidant system (amygdala) and/or an inefficient supervisory system (medial/ventral prefrontal cortex). Perturbations in these systems may contribute to the expression of psychopathology, illustrated here with depression and anxiety.

Conclusions

A triadic model, integrated in a temporally organized map of motivated behavior, can provide a helpful framework that suggests specific hypotheses of neural bases of typical and atypical adolescent behavior.     

Le modèle du réplicon est-il applicable aux eucaryotes supérieurs?

Thirty-five years ago, the Replicon model was proposed by Jacob, Brenner and Cuzin to explain the regulation of the Escherichia coli DNA replication. In this model, a genetic element, the replicator, would function as a target for a positive-acting initiator protein to drive the initiation of replication. This simple idea has been extremely useful in providing a framework to explain how the initiation of DNA replication occurs in all organisms. The identification of autonomously replicating sequences (ARSs) in budding yeast was the first extension of the Replicon model to eukaryotic chromosomes. In the higher eukaryotes, many biochemically defined replication start sites have been identified; nevertheless there is little genetic data indicating that these sites contain DNA sequences that are essential for replication. Moreover, in early Xenopus or Drosophila embryos, specific DNA sequences are not required either for initiating DNA replication or for preventing rereplication within a single cell cycle. This apparently fundamental difference between replicators in yeast and metazoan embryos may be more superficial than initially thought. In fact, during the past several years, an eukaryotic initiator conserved from yeast to man and also present in embryonic cells, the origin recognition complex (ORC), has been characterized, suggesting that the initiation mechanism should be essentially the same in prokaryotes and eukaryotes. In addition, the efficient once-per-cell-cycle replication of DNA is ensured in eukaryotes by a simple two-step mechanism in which the assembly of stable prereplicative complexes (PreRCs) at origins precedes and is temporally separated from the firing of these origins. Regulation of this process by cyclin-dependent kinases ensures that when origins fire, the cell is no longer competent to form new PreRCs. Now, it is important to understand how these complexes are remodeled or disassembled during replication initiation to trigger the transition from a stable origin-bound complex to a mobile replication machine.     

Guide à la lecture et interprétation de l’imagerie PET des plaques amyloïdes

The extracellular deposits of beta-amyloid are one of the histological lesions required for the neuropathological diagnosis of Alzheimer's disease. During the last decade, various PET tracers have been validated and have market authorization for the visualisation in vivo of amyloid plaques, with excellent sensitivity and specificity. The aim of this paper is to provide a practical guide for the visual read and interpretation of this image modality and to discuss its most recent developments for the integration in the diagnostic process and in patient management.     

Polymorphisme électrophorétique des protéines et enzymes sériques et érythrocytaires chez le chimpanzé (Pan troglodytes)

Summary The electrophoretic mobilities of serum enzymes and other proteins were investigated at 35 loci in 25 unrelated individuals of the chimpanzee Pan troglodytes. In this population the mean average of individual polymorphism is =0181, and the average level of heterozygoty =0.022. The same pattern of individual variability is found in Pan troglodytes and Homo sapiens.     

Enquête nationale en médecine nucléaire : radiopharmaceutiques et activités utilisés en 2007 dans le secteur public

The Institute for radiation protection and nuclear safety (IRSN) and the National institute for health surveillance (InVS) have been collaborating since 2003 to provide updated data on medical exposure of the French population related to medical diagnosis. In this framework, a survey was carried out by IRSN in 2009 within all the 127 departments of nuclear medicine belonging to public hospitals. The rate of participation was high (72% of the departments). The first objective of this survey was to estimate the activity of these nuclear medicine departments (numbers and types of examination, according to their code in the French common classification for medical care). The second objective was to collect data related to the dose delivered to the patient for each type of examination. This article details this second part of the survey and presents, for the 32 most frequent types of examination, the radionuclide used and its chemical form, the average administered activity per examination and the activity range for the responding departments. When a French dose reference level exists, this survey showed that the average administered activity is in agreement with it, excepted for the ^99mTc thyroid scintigraphy with an administered activity close to twice the dose reference level (DRL). The dispersion of administered activity between the departments for a same type of examination depends on the type of examination, and is comprised between 2 and 10 for a 70 kg patient.     

Hypothèse : le modèle du lieu de rencontre pour la maladie des prions

Prions are responsible for spongiform diseases such as scrapie and bovine spongiform encephalopathy. It is now generally accepted that the disease mechanism involves the conversion from the normal form, PrP^C, to the pathogenic form, PrP^Sc, and that this isoform is infectious. In the case of scrapie, 15 different forms of the disease have been described and some of these different phenotypes can be conferred by infectious prions that are themselves encoded by normal genes. We propose here that a prion with an altered structure has a correspondingly altered preference for lipids; this altered preference creates a proteolipid domain containing different lipids and other factors such as chaperonins and enzymes responsible for post-translational modifications. Normal prions associated with this abnormal domain adopt the conformation dictated by its lipidic composition (and by the other factors present) and so acquire the lipidic preference of the original pathogenic prions. These transformed prions could then create new proteolipid domains. This process may be considered as semi-conservative replication in which prion and lipids are analogous to the Watson and Crick strands and the proteolipid domain to the double helix itself.