Comparaison de deux méthodes de mesure des TLG en TEP au 18-FDG dans le mélanome métastatique

IntroductionThere are many automated segmentation softwares in PET-CT, but none of them is used as gold standard. The aim of this study is to compare two segmentation softwares, one based on maximum intensity projection (MIP-based) and the second: PETVCAR^®, to measure TLG in patients with metastatic melanoma treated by vemurafenib.Materials and methodsSixteen patients were assessed by PET using 18-fluorodesoxyglucose (18-FDG) before and during the treatment with vemurafenib. TLG were measured by MIP-based and PETVCAR^® and then analysed in initial PET, all PET, by organ and added for each PET.ResultsThere is a good correlation between TLG in each method (r = 0.96 with P = 0 on 439 lesions on all PET). The mean difference between TLG PETVCAR^® and TLG MIP-based is negative. Segmentations are larger with MIP-based than with PETVCAR^® with discrepancies observed for larger and heterogeneous lesions. SUV_max doesn’t seem to be the factor causing these discrepancies. Correlation between the difference of TLG and their mean is also strong especially in bones, nodes and subcutaneous lesions.ConclusionBoth methods have a good correlation in spite of discrepancies observed for large or heterogeneous lesions. These lesions segmentations are larger with the method based on MIP than with PETVCAR^®.     

Changements de l'epithélium médian des bourgeons palatins de souris au stade de préfusion

Résumé Avant d'entrer en contact, les surfaces de fusion des processus palatins subissent des modifications. Certaines cellules épithéliales superficielles deviennent turgescentes, alors que d'autres conservent un aspect dense et aplati, elles se lysent et éclatent. Des noyaux semblables à ceux des assises profondes se retrouvent en surface, paraissant migrer vers le bourgeon antagoniste. Des projections filamenteuses apparaissent, quelques unes établissant un contact avec l'épithélium opposé, d'autres restant seulement sous forme d'expansion. Ces observations sont concordantes en microscopie photonique et en microscopie électronique à balayage.

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Modification of the medial epithelium of the palatal shelves of mice at the prefusion stage. A light and scanning electron microscopy study

Summary The fusion surfaces of the palatal processes are modified before coming into contact. Several superficial epithelial cells become hypertrophied, undergo lysis and burst, whereas others remain flattened and densely stained. Nuclei, similar to those localized in deeper layers are found on the surface and seem to migrate towards the opposite process. Filamentous projections appear and some establish a linkage with the opposite epithelium, whereas others expand freely from the surface. Light microscope observations agree with scanning electron microscopy findings.

     

Une méthode simple de prévision des tendances appliquée aux séries temporelles de qualité des eaux courantes

Missing values, non-regular sampling, censored data and departure from normality are common problems in the analysis of ecological or environmental time series. For over 20 years, in the scope of the National Basin Network in France, numerous water quality time series have been collected. A method is proposed for the regularization of the series, the detection of trend changes and short-term forecasting, on the basis of the last detected trend, using a non-parametric regression. The method is applied to phosphates and nitrogen concentrations measured on the Sambre river (northern France).     

Etude de la migration des cellules somitiques dans le mésoderme somatopleural de l'ébauche de l'aile

Summary In chick embryos, observations were made on serial semithin transverse sections of the wing level. In addition homo- or heterotopic replacements of the wing or leg somitic mesoderm by labelled somitic or nonsomitic mesoderm were made in 2-to 2.5-day embryos. The nuclear label used was either natural (quail donor embryos in heterotopic transplantations) or isotopic (chick donors labelled with tritiated thymidine).Histological examination revealed that the first somitic cells to leave somite 15 apparently did so at the 20 to 22 somite stage, while the last ones to leave somite 20 apparently did so shortly before the 36 somite stage.Transplantation experiments with labelled donor cells revealed the routes of migratory somitic cells and the time-course of their invasion into the outgrowing limb bud (non-somitic graft cells did not noticeably invade the limb anlage). They showed furthermore that the somitic mesoderm is not regionalized with respect to its limb myogenic properties.These results are compared with those obtained in other classes of vertebrates.

Ce travail a été subventionné en partie par la D.G.R.S.T. et le C.N.R.S.     

Identification par immunofluorescence des cellules corticotropes et mélanotropes de l'hypophyse des Amphibiens

Résumé Les antisérums préparés à l'égard de trois hormones de synthèse [β(1–24) corticotropine, α et β MSH] nous ont servi pour localiser par immunofluorescence dans l'adénohypophyse des Amphibiens les sites d'élaboration de l'ACTH, de l'α et de la β MSH. Les anticorps anti-α et anti-β MSH se fixent exclusivement sur les cellules de lapars intermedia tandis que l'anti β-(1–24) corticotropine révèle simultanément une catégorie de cellules de lapars distalis et des cellules de lapars intermedia. D'après le contr?le cytologique effectué par la technique au bleu Alcian PAS, l'ensemble de ces cellules sont PAS positives et bleu alcian négatives. Elles réagissent également à la paraldéhyde fuchsine en l'absence d'oxydation permanganique. La signification de ces résultats est discutée.

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Identification by immunofluorescence of the corticotropin and melanotropin cells in Amphibian pituitary

Summary Antisera prepared against synthetic β(1–24)corticotropin (synacthen) α and β MSH were used to localize, by immunofluorescent procedure in the adenohypophysis of Amphibians, the site of production of ACTH, α and β MSH. Anti-α and anti-β MSH antibodies appeared to be bound only to thepars intermedia cells whereas anti-β(1–24) corticotropin reacted simultaneously with specific cells of thepars distalis and cells of thepars intermedia. Cytological control by alcian blue (pH 3) PAS technique proved that all these cells are PAS positive and alcian blue negative. They react also with paraldehyde fuchsine without oxidation. The possible significance of these results is discussed.

     

L'enseignement des sciences morphologiques dans 13 facultés de médecine canadiennes

A survey of teaching of morphologic sciences in Canadian medical schools has shown that few radical changes have taken place in most schools. The survey has also shown the following: (a) department chairmen have a major influence on teaching of morphologic sciences; (b) they are worried about the diminishing time alloted to them; (c) students, by their choice of electives, do not seem to share that worry; (d) lectures remain popular, as does disection in most schools; and (e) audiovisual methods, especially rediology, are becoming more popular but are not yet used on a very large scale.     

Sera-T-Il possible de mécaniser la préparation des tableux phytosociologiques?

Sans résuméReçu par la rédaction le 30.X.1953.     

Nouveaux traceurs TEMP : exemple des traceurs des protéoglycanes et de la mélanine

The majority of research program on new radiopharmaceutics turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The ^99mTc-NTP 15-5 which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodobenzamides, specific to the melanin, are nowadays compared to ¹⁸F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on BZA heteroaromatic analogues usable for melanoma treatment.     

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.     

Comparaison de différentes méthodes de segmentation en TEP/TDM pour le ciblage en radiothérapie des carcinomes épidermoïdes des VADS

IntroductionTo assess interobserver variability for biological target volume (BTV) delineation and to compare the reproductibility of different semiautomatic segmentation methods in pretreatment 18-fluorodeoxyglucose positron emission tomography (PET/CT) of head and neck squamous cell carcinoma (HNSCC).Patients and methodsPatients with histologically proved HNSCC referred to the nuclear medicine service in Brest for pretreatment PET/CT were prospectively included from February 2009 to June 2010. Three nuclear medicine physicians (two specialized in oncology) delineated manually and independently BTV on each primary tumor. Four semiautomatic segmentation methods have been studied; three using a fixed threshold and one applying an adaptive threshold based on the signal-to-background ratio (Daisne). The variability between κ observers and/or methods has been assessed. The concordance between the various BTV intersections and unions has been also assessed.ResultsThirty patients (29M; 1F) were included. The primary site location was oropharynx in six patients, oral cavity in 10 patients, hypopharynx in five patients and larynx in nine patients. A statistically significant global interobserver variability (P = 0.01) was showed, but without statistically difference between the two experienced oncologists (P = 0.15). The maximal concordance of the two experienced observers with the semiautomatic methods was found for the Daisne method (CI = 61.5%; κ = 0.68), expressing a good agreement according to the Landis and Koch criteria, better than with the segmentation method using a fixed threshold with 40% of maximal signal intensity (CI = 52.1%; κ = 0.53).ConclusionOur results suggest the feasibility of achieving HNSCC BTV delineation by PET/CT using semiautomatic methods, in particular those which apply an adaptative threshold but under the supervision of an experienced operator.     

Phylogénie de champignons responsables des charbons des végétaux à partir de l'analyse des séquences ITS

Phylogenetic relationships among fungi belonging to the family of Ustilaginaceae (genera Microbotryum, Sphacelotheca, Ustilago, Sporisorium) are inferred from a parsimony analysis using the ITS sequences of nuclear ribosomal genes. The introduction in the phylogeny of sequences from species of Suillus, Puccinia and Taphrina as outgroup shows the polyphyletism of this family. These results support the division of this taxon into two groups: Ustilaginaceae s. str. formed only by the pathogens of Poaceae, and Microbotryaceae constituted by the pathogens of Dicotyledons. Furthermore, we proposed to extend the host plant spectrum of Ustilaginaceae s. str. to all the Monocotyledons. Several discriminating characteristics are listed to support this distinction.     

Assurance qualité du circuit des médicaments radiopharmaceutiques du service de médecine nucléaire de l’hôpital Ibn Sina de Rabat

Since Law n^o 17-04 of the national code of medicine and pharmacy, published in the official newspaper of November 22, 2006, radiotracers used in nuclear medicine in Morocco have become drugs or diagnostic radiopharmaceuticals. As such, radiopharamaceuticals must meet the requirements of pharmaceutical quality and control that apply to any drug (Payoux and Prigent, 2009 [5]). This task must be undertaken under the pharmacist's responsibility with a specific skill known as “radiopharmacist” (Morera et al., 1993 [6]). In the situation of Moroccan hospital, like Ibn Sina hospital for which the only law of the national code is partially applied, nevertheless the pharmacy department cannot ignore this issue. As part of this work, we present the proposed new quality installation service for 24 months. It aims to improve the proper use of radiopharmaceuticals, to contribute to the quality of diagnostic and therapeutic procedures and especially to ensure the optimal conditions of safety for staff and patients. This activity closely affects the pharmaceutical supply, preparation, dispensing and management of radioactive waste resulting from handling radiopharmaceutical drugs. Radiopharmaceutical quality control of was also integrated into the global quality control program, despite the technical constraints encountered during their day-to-day practice. Our basic documentation referred to European directives (Pharmacopée européenne, 2010 [8]), French Pharmacopoeia (Bonnot-Lours, 2000 [2]) and good preparation practise rules (Afssaps, 2006 [3]). The reflection was undertaken within a multidisciplinary framework: nuclear physician, physicists, a pharmacist working in hospitalpharmacy, chemists of the drug control department, computer and paramedical staff (technicians, nurses, and cleaners).     

Classification des stades de sommeil par des réseaux de neurones artificiels hiérarchiques

The goal of our work is to provide an automatic analysis and decision tool for sleep stages classification based on an artificial neural networks (ANN). The first difficulty lies in choosing the physiological signals representation and in particular the electroencephalogram (EEG). Once the representation adopted, the next step is to design the optimal neural network determined by a learning and validation process of data from a set of sleep records. We studied several configurations of conventional ANN giving results varying from 62 to 71 %, then we proposed a new hierarchical configuration, which gives a rate of 74 % correct classification for six stages. These results lead us to further explore this issue at the representation and design of ANNs to improve the performance of our tool.