Effets de la fluorescence résiduelle dans les tissus biologiques sur les signaux de fluorescence résolus temporellement par la méthode des éléments finis

A computational model based on finite element method is derived to examine how the simulated time-dependent signals are related to the presence of residual fluorescence in biological media surrounding a fluorescent object. We apply a subtraction technique on recorded data when imperfect uptake of fluorescing agent into the tumor is considered. We show the limits of the subtracting method for low target: background fluorescent absorption contrast by extracting the time to reach the half maximum and analyzing the maximum of the time-resolved signals versus target depth.     

Densités de primates en forêt guyanaise. Test d'une méthode d'estimation par transect

The results of a classical transect method designed to evaluate primate density are compared with estimates obtained from long-term studies on three species within a community inhabiting an undisturbed rain forest (French Guiana). Combining results of both methods, the total density of the primate community, which includes six species, is about 70 individuals per square kilometre. The concordance of data noted in Alouatta seniculus, Cebus apella and Saguinus midas, makes the transect method a reliable approach to low primate densities overall. However, it requires that long cumulative distances are walked and does not guarantee that rare species will not be missed. The predominance of Alouatta within the community, as observed in numerous Amazonian communities, is interpreted in relation to the nutritional quality of its environment and weak feeding competition between primate species.     

Évaluation d’une méthode de quantification de la masse métastatique osseuse par mesure automatisée du Bone Scan Index,dans le suivi thérapeutique des cancers du sein

IntroductionThe objective assessment of therapeutic response is a major diagnostic and therapeutic management in breast cancer with bone metastases. The objective of the study was to test performance of an automated method for quantifying the extent of skeletal tumour involvement in breast cancer, using the Bone Scan Index (BSI), and study if BSI could be considered as an imaging biomarker of metastatic bone disease.Materials and methodsOne hundred and two planar bone scans, corresponding to 34 treatment (three successive bone scans) of 31 patients were retrospectively analyzed. Each image was reviewed by two nuclear physicians, a senior and a junior. Exini Bone^® software calculated automatically the BSI for each scan.ResultsAt 3 times of the study, agreements between automatic and visual methods were intermediate: 55.88% (kappa = 0.3704), 52.94% (kappa = 0.3052) and 52.94% (kappa = 0.2173) with junior nuclear physician and 52.94% (kappa = 0.33), 55.88% (kappa = 0.3333) and 50% (kappa = 0.1939) with senior nuclear physician. Six initial bone scans (17%) were considered normal (BSI = 0) by the software; with bone lesions confirmed by morphological imaging and/or histology. Agreements between junior and senior were high, with kappa = 0.81, 0.91 and 0.94 at 3 times of the study. Confrontation with routine analysis showed significant variability with agreements from 47.06 to 76.47%. We did not find any significant relationship between evolution of BSI and tumor markers over time. Only a trend between evolution of CA15-3 and BSI was observed. We did not find any significant association between overall survival and value of BSI.ConclusionIn breast cancer, the fully automated platform of quantifying the BSI seems to have limitations, because of characteristics of bone metastases of breast cancer, and their scintigraphic translation. BSI seems to be an interesting tool, and it could be improved: development of diagnostic “assisted” by computer, combining power of medical knowledge and technical computing could help to score bone disease, and allow standardized monitoring.     

Influence de la méthode de fixation sur l'observation des divisions cellulaires dans l'adénohypophyse du rat mâle

Résumé Les mitoses de l'adénohypophyse du rat mâle ont été examinées comparativement après fixation par perfusion et après fixation par immersion.Après fixation par perfusion la répartition topographique des mitoses dans le parenchyme est homogène, et l'index mitotique est de 1,85 pour 1 000 cellules.Après fixation par immersion, la densité des mitoses décroit de la périphérie vers le centre, et l'index mitotique n'est que de 0,80 mitoses pour 1 000 cellules.La lenteur de pénétration du fixateur pendant l'immersion est tenue pour principal responsable des différences observées. Elle entraîne une modification de l'aspect des mitoses, telle que plus de la moitié d'entre elles ne sont pas identifiables et échappent aux comptages.

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Influence of fixation on the observation of mitoses in the male rat adenohypophysis

Summary The mitoses of the adenohypophysis in male rats have been observed comparatively after fixation by perfusion and fixation by immersion.After fixation by perfusion, the topographic distribution of mitoses throughout the parenchyma is homogenous and the mitotic index is 1.85 for 1 000 cells.After fixation by immersion, the density of the mitoses is decreasing from the periphery towards the center and the mitotic index is only 0.80 for 1 000 cells.The slow penetration of the fixative during fixation by immersion is considered to be the main cause in the differences observed. This slow action causes a modification in the aspect of the mitoses, and more than fifty percent of them cannot be identified and escape to the counts.

Avec la collaboration technique de Mademoiselle J. Rameau.     

Valeur trophique des acides aminés dans les graines de légumineuses et développement larvaire de Callosobruchus maculatus

Interspecific variation of protein amino acids between peanut, horse bean, french bean, lentil, cowpea and chick-pea was undertaken in relation to larval development of C. maculatus. Twenty-one groups of amino acids were identified and quantified. In all seeds, free amino acids exist in low quantities; but they are more numerous than bound amino acids. Essential amino acids for man are sufficient in the six species, except for the sulphur amino acids in all seeds, and for lysine in peanut. Utilization of those pulses, after cooking, in human food complements cereals. Larval development possibilities of C. maculatus upon the used seeds shows up that: (a) with chick-pea and cowpea, the bruchid thrives normally. However, although amino acids are higher in cowpea than in chick-pea, the better performances were observed on the latter; (b) peanut, french bean, horse bean and lentil are unsuitable for larval development of the insect. Although they are rich in amino acids, all larvae die at first in star within these pulses. We conclude that larval development of C. maculatus does not depend only on the amounts of amino acids in the seeds but also on other trophic factors. These could consist of the balance between different nutritive compounds and the presence of allelochemical substances in the tested seeds which bruchid larvae are unable to utilize.     

Émission de rayonnement par les œufs de Discoglosse en cours de développement

Sans résumé     

Comparaison de différents indices métaboliques et de la méthode SULTAN dans l’évaluation de la réponse thérapeutique par TEP au 18FDG dans le cancer du sein métastatique

Objective18F-FDG PET is a valuable tool in the evaluation of therapeutic response in breast cancer. This retrospective study was designed to compare the performance of six metabolic indices and to define their optimal thresholds, in patients treated with chemotherapy or hormone therapy for metastatic breast cancer. The performances of a parametric analysis by SULTAN method were also evaluated.MethodsTwenty patients, who underwent from 2 to 7 PET during the follow-up were analyzed. For each target, six indices were measured: SUVmax (maximum Standardized Uptake Value), SUVpeak, SAM (Standardized Added Metabolic activity), metabolic volume (MV), SUVmean using an adaptive threshold, and TLG (total lesion glycolysis). The percentage change of each target between each PET was calculated. A method based on parametric imaging (SULTAN) was also applied to each patient. The results were compared to the gold standard, defined by clinical evaluation, biological and morphological imaging RECIST 1.1 criteria. A per-lesion and per-patient analysis were performed and the optimal thresholds for each indices were calculated.ResultsFor the per-lesion analysis, 61 targets and 111 evolutions with 67 responders (R) and 44 non-responders (NR) were studied. Using ROC curve analysis and intercomparison, SUVmax, SUVpeak and SUVmean were significantly better than SAM, TLG and VM (P < 0.05). Using the optimal thresholds of −21%, –21%, –34%, –48% and –23% for SUVmax, SUVpeak, SUVmean, SAM and TLG respectively, these five indices were significantly correlated with the gold standard. SUVmax, SUVpeak and SUVmean showed the best performances of sensitivity (88%, 87% and 78% respectively), specificity (93%, 93% and 98% respectively) and negative predictive value (NPV) (84%, 69% and 74% respectively). For the per-patient analysis, 42 pairs of PET with 22 R and 20 NR were studied. Only SUVmax and SUVpeak were correlated to gold standard with the 30%-PERCIST-threshold and with optimal thresholds with performances of sensitivity of 73% and 77%, specificity of 95% and NPV of 76% and 79%. Parametric analysis with SULTAN showed excellent performances in the per-lesion and per-patient analysis (sensitivity 84% and 82%, specificity 98% and 90%, NPV 80% and 82%, respectively).ConclusionSUVmax and SUVpeak appeared the best indices to evaluate metabolic response in metastatic breast cancer. The SULTAN method was a reliable method to assist interpretation.     

Etude des fluctuations annuelles des copépodes et du phytoplancton dans la manche et le golfe de gascogne par la méthode d'analyse de la variance et du coefficient de correlation

2275 samples have been collected with the Continuous Plankton Recorder of Hardy at a standard depth of 10 meteres in the English Channel and the Bay of Biscay between 1958–1965. Biological as well as statistical analyses have been carried out to provide data on annual fluctuations of 34 species of copepods and phytoplankton. Methods of analysis of variance and the correlation coefficient analysis were used for this purpose. The results are presented in the form of triangular matrices showing the annual fluctuations of species in the different areas considered and the relationship between different species in each area. These methods allowed us to define separate groups of species that could be called annual communities.

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Extrait d'une thèse de Doctorat en Oceanographie biologique, soutenue à la faculté des Sciences de Paris le 19 décembre 1967. Ce travail a été subventionné par the Office of Naval Research, Department of the United States Navy en vertu du contrat No 62558-3612.

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Extrait d'une thèse de Doctorat en Oceanographie biologique, soutenue à la faculté des Sciences de Paris le 19 décembre 1967. Ce travail a été subventionné par the Office of Naval Research, Department of the United States Navy en vertu du contrat No 62558-3612.     

Influence d'une lame métallique sur la distribution de la dose dans le plexiglas irradié par des électrons de haute énergie

Résumé Une lame hétérogène deZ plus élevé que celui de l'eau, provoque dans un faisceau d'électrons de haute énergie une modification de la distribution de la dose en profondeur.La dose est augmentée au contact et au voisinage immédiat de la lame hétérogène, tandis qu'elle est diminuée à plus grande distance.Dans le cas habituel de la radiothérapie, où la lame hétérogène est constituée par une épaisseur limitée d'os, et de l'expérimentation radiobiologique, où l'hétérogénéité est constituée par les parois de verre, le surdosage reste inférieur à 5% pour les électrons d'énergie comprise entre 10 et 20 MeV.La distribution de la dose en profondeur est approximativement représentée par la courbe standard, si les profondeurs sont exprimées en masse surfacique (g/cm²).On peut donc admettre une épaisseur d'absorption équivalente (A E T) égale à l'épaisseur réelle multipliée par la densité de la lame hétérogène.Cependant dans les expérimentations rigoureuses qui exigent une précision élevée, le calcul de la dose en profondeur par l'A E T, peut ne pas être satisfaisante, et la mesure directe est indispensable.     

Hyperparasitisme facultatif de parasitoïdes en cours de développement par les femelles des ectoparasitoïdes Eupelmus vuilleti et Eupelmus orientalis Craw

In a community of three ectoparasitoids, Dinarmus basalis, Eupelmus vuilleti and E. orientalis, the host Callosobruchus maculatus parasitised 48 h before by D. basalis, is accepted by E. vuilleti females after they have eliminated the eggs and neonatal larvae of D. basalis. This ovicidal and larvicidal behaviour enables E. vuilleti to develop on C. maculatus instead of D. basalis. E. vuilleti females are able to parasitise the L5 larval stage and the pupa of D. basalis: their larvae therefore feed at the expense of the developing parasitoid. This trophic level is that of hyperparasitism. However, E. vuilleti females rarely practise hyperparasitism on their own L5 larvae and on those of E. orientalis. This behaviour reveals a high behavioural plasticity enabled by intra- and interspecific recognition of parasitoids used as hosts. Hyperparasitism activity in E. orientalis females is higher than that in E. vuilleti females since they hyperparasitise host parasitoids more frequently without preferential species choice. However, E. vuilleti seems to be free from competitive pressure with E. orientalis, as the former penetrates deeply into a grain store contaminated with C. maculatus in contrast to E. orientalis females, which remain on the surface from where they escaped.     

Apoptose et ségrégation méiotique dans les spermatozoïdes d'hommes porteurs de translocations

Men with a chromosomal translocation produce a significant percentage of unbalanced spermatozoa. In order to determine a correlation between chromosomal anomalies and apoptosis in human sperm, we analysed DNA fragmentation and meiotic segregation in sperm from men with a (13;14) Robertsonian translocation. We studied sperm from 12 (13;14) translocation carriers and 9 proven fertile men with a normal karyotype. Meiotic segregation of chromosomes 13 and 14 was analysed using dual-colour fluorescencein situ hybridization with locus-specific probes for chromosomes 13 and 14. Apoptosis in spermatozoa was measured byin situ TUNEL assay. The meiotic segregation study showed a significantly increased frequency of unbalanced spermatozoa for chromosomes 13 and 14 in (13;14) carriers (15.9%) compared to the control population (1.3%) (p=0.00016). The study of apoptosis showed an increase of DNA fragmentation in (13;14) carriers (34.9%) compared to the control population (13.8%) (p=0.0036). This increased apoptosis was observed in spermatozoa presenting an increase of unbalanced chromosomal anomalies concerning chromosomes 13 and 14, but with a predominance of balanced spermatozoa compared to the theoretical risk of meiotic segregation. These results suggest that apoptosis could be involved as a regulatory mechanism to eliminate unbalanced chromosomal spermatozoa in men with a (13;14) Robertsonian translocation.     

Impact de la méthode de segmentation dans la caractérisation des adénocarcinomes pulmonaires en TEP-TDM au 18FDG

ObjectiveThe treatment of lung adenocarcinomas is conditioned by the presence of certain genetic abnormalities. Certain quantitative parameters obtained from FDG PET-CT, at the voxel scale, provide tumour shape and texture characteristics and might predict their mutational status. Our objective was to determine the impact of the segmentation method in the characterization of lung adenocarcinomas in FDG PET-CT.MethodsForty-nine patients with pulmonary adenocarcinomas were retrospectively included, with their initial FDG PET-CT image. The studied tumours were big, heterogeneous and difficult to segment automatically. The automatic FLAB algorithm was used with and without manual adjustment. The parameters were extracted and compared to the ALK, PDL1, and KRAS status, in order to compare the performances of the two segmentation methods. Their performance was determined by the ROC curve method.ResultsSeveral parameters were significant to predict genetic status (AUC > 0.65). The best performing parameters were different according to the genes studied and according to the resampling methods used. The results were less dependent on resampling in automatic segmentation without manual adjustment. The best performing parameters were volume dependent parameters for segmentation with manual adjustment, and texture parameters for automatic segmentation without adjustment.ConclusionThe study of texture parameters is more efficient in automatic segmentation that is not manually adjusted, and it is advantageous to use a manual adjustment when studying volume-dependent parameters in the case of very heterogeneous tumors.     

Etude preliminaire de stades de la méiose humaine dans les spermatocytes et les ovocytes

Summary Human meiotic chromosomes, from spermatocytes and ovocytes, are described after observations of whole mount preparations under E.M. Small testicular and ovarian fragments are put in distillated water, then macerated; the cell suspension is spread on the surface of sheet copper grids covered with formvar plus collodion films. After dehydratation interesting stages are selected under L.M. before observations under E.M.Zygotene and pachytene are the most common stages. During pachytene the chromomeres are well individualized; the synaptonemal complex may be observed; chromatin fibers connect the chromosomes to nuclear pores, interchromosomal fibers joint the bivalents. Zygotene and pachytene bivalents are very similar in the male and the feminine germ cells.     

Dépistage de la trisomie 21 par les marqueurs sériques

Jusqu’ au milieu des années 80, la seule stratégie de dépistage consistait à proposer une amniocentèse aux femmes agées de 38 ans et plus. Puis, les progrès liés au développement de l’échographie ont permis de révéler des malformations fœtales, ce qui a ouvert la voie au dépistage des anomalies chromosomiques chez les femmes plus jeunes. Enfin, la mise en évidence de marqueurs biochimiques dans le sérum maternel au 2^ème trimestre de la grossesse a conduit à une extension du dépistage de la trisomie 21 à toutes les femees enceintes quel que soit leur age, que le fœtus présente ou non des malformations visibles à l’échographie.     

Principes de préparation et de congélation des spermatozoïdes testiculaires humains

The advantages and feasibility of human testicular spermatozoa cryoconservation for intracytoplasmic sperm injection (ICSI) have now been clearly demonstrated. However, the freezing protocol is based on empirical knowledge obtained from freezing of ejaculated spermatozoa. Testicular spermatozoa may not be fully mature gametes and may also be retrieved in only limited quantities. Little research has been conducted to determine whether they have the same cryobiological requirements as ejaculated spermatozoa. A better understanding of their cryobiological features and assessment of possible subcellular changes after thawing would help to optimize testicular preparations for cryopreservation (whole biopsies, seminiferous tubules, shredded suspension, single spermatozoa, etc.), freezing-thawing procedure, freezing media, and storage. Finally, there is a growing need for welldefined criteria (nuclear quality, etc.) to evaluate the tolerance of testicular spermatozoa to freezing-thawing procedure for ICSI