Modélisation de l'impact des mollusques cultivés sur la biomasse phytoplanctonique de l'étang de Thau (France)

A model coupling a 2D transport equation and a simple model of the nitrogen cycling was developed for the Thau lagoon (France). The model took into account the wind forcing on the hydrodynamism, the effect of the temperature on the biological processes, the input of the watershed area, the light dependence of the pelagic primary production and the prédation of the phytoplankton by the cultivated filter feeders. The model ran under two steady-state situations of wind with constant temperature and light values corresponding to spring weather conditions. Simulations showed that the biological flows were very sensitive to the wind. The budget of the nitrogen flows were computed for the three areas devoted to the filter feeder cultivation and the results highlighted the impact of cultivated oysters as a source of nutrients and an important nitrogen flow through the predation of phytoplankton.     

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.     

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.     

Nouvelles recherches sur la systématique et l'éthologie des Termites champignonnistes du genreBellicositermes Emerson

Sans résumé     

Interêts du dosage des adénosines 5′-phosphate pour l'étude de la dynamique des populations phytoplanctoniques lacustres (le Pavin - France)

A study on A.T.P., A.D.P. and A.M.P. in the phytoplankton of Lake Pavin was carried out from November 1976 to December 1977. Samples were collected at nine depths, between the surface and 50 m.A.T.P., A.D.P. and ( = A.T.P.+ A.D.P. + A.M.P.) show a similar behaviour in space and time but A.M.P. behaves independently. The A.M.P. concentration is high only when primary production of phytoplankton is high.The energy charge [CE = (ATP + % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSGaaeaaca% aIXaaabaGaaGOmaaaaaaa!3776!\[{\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-\nulldelimiterspace}\!\lower0.7ex\hbox{$2$}}\]ADP)/(ATP + ADP + AMP)] could be used as measure of adaptation in algal populations. Indeed, the energy charge increases as algal cells experience difficulty in maintaining themselves in the biotope.

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Interêts du dosage des adénosines 5-phosphate pour l'étude de la dynamique des populations phytoplanctoniques lacustres (le Pavin - France)

     

Impact diagnostique de l’imagerie hybride TEMP/TDM dans la prise en charge des neuroblastomes. Expérience du service de médecine nucléaire du CHU Mohammed VI de Marrakech

IntroductionThe neuroblastoma is a malignant pediatric tumor of the peripheral sympathetic nervous system. This is the pediatric solid extracranial tumor most common and accounts for approximately 8 to 10% of childhood cancers. The diagnosis is based on imaging showing a tumor developed at the expense of the sympathetic nervous system, increased urinary catecholamines, increased uptake of meta-iodo-benzylguanidine (MIBG) and histology who finds a malignant proliferation of small round cells. An assessment of the tumor mass and its extension are required to assess the prognosis and adapt the treatment. The MIBG scintigraphy is a non-invasive imaging technique that can evaluate with a single review the totality of the tumor extension. The single-photon emission computed tomography/computed tomography (SPECT/CT) improves the sensitivity of the examination, it allows an anatomical and functional study and improves the anatomical localization of scintigraphic uptake observed. The purpose of our work is to illustrate the contribution of the SPECT/CT in addition to the planar MIBG scintigraphy in the diagnosis and staging of neuroblastoma about four cases.Case reportClinical case 1: a 4-year old child, presented for 2 months abdominal pain. In the clinical examination, he presented a hard abdominal mass, painless and right paramedian. Abdominal ultrasound showed a right retroperitoneal mass with lymph nodes. The dosage of urinary catecholamines was increased. The ¹³¹I-MIBG scintigraphy showed an image for a right adrenal neuroblastoma measuring 8.6 × 4.5 cm. Surgical excision of the adrenal mass revealed in the anatomopathologic study a malignant tumoral proliferation with round cells compatible with a neuroblastoma. Clinical case 2: a 10-month old infant, presented since 15 days an exophtalmia with poor general status. The clinical examination showed a right abdominal mass and a bilateral periorbital ecchymosis. The radiography of the thorax showed a widening mediastinal. Abdominal echography showed a tissular mass of the right adrenal gland with retroperitoneal lymph nodes and an ascites. The dosage of urinary catecholamines was increased. The ¹³¹I-MIBG scintigraphy showed a right adrenal neuroblastoma measuring 6.4 × 2.7 cm with orbital bone metastases in favor of a Hutchinson syndrome. Clinical case 3: a 2-month old infant, followed since 1 month for bilateral adrenal neuroblastoma. The clinical examination showed an important abdominal distension with bluish nodules under skin. The abdominal echography and the abdomino-pelvic TDM showed two adrenal masses corresponding to a bilateral neuroblastoma with liver metastases. The ¹³¹I-MIBG scintigraphy showed two adrenal masses measuring respectively 6.5 × 3.4 cm and 8 × 6 cm, with liver and skin metastases in favor of 4S neuroblastoma with bilateral adrenal tumors. Clinical case 4: a 3-year old child, followed for left adrenal neuroblastoma with multiple bone metastases. The clinical examination showed a left abdominal mass with exophtalmia and right palpebral ecchymosis. The radiography of the thorax showed a widening of the mediastin with repression of the paravertebral right line. Abdominal echography showed a left retroperitoneal tissular mass measuring 9.2 × 5.2 cm. The abdomino-pelvic TDM showed a left adrenal tumor with lumbar vertebral bone metastases. A first ¹³¹I-MIBG scan showed a left neuroblastoma with multiple bone metastases in the right orbit, the right humerus, the occipital bone, the right scapula and spine (D10, D11, L1, L3, S1). The child was treated by 5 courses of chemotherapy (protocol HRNLB/10). The ¹³¹I-MIBG scan control showed a regression of neuroblastoma size (1.4 × 1.2 cm) with loss of bone metastases of the occipital bone, the right scapula and spine.DiscussionThe MIBG scintigraphy is a simple, non-invasive examination that has excellent sensitivity and specificity in detection of neuroblastoma and especially in invasion bone marrow and in evaluation of the therapeutic response. The hybrid SPECT/CT imaging improve the performance of the scintigraphy as well in sensibility, toward the deep localization, as in specificity for images poorly defined in planar imaging.     

Notes sur l'écologie et l'éthologie des espèces du genreLasius (Hymenoptera Formicid≸)

Summary Among species of the Ant genusLasius, nests sites and nesting habits differ according to the ecological requirements of every species. A classification of these habits has been outlined taking into consideration the complexity of the building techniques and the nature of the building materials. Whithin one single species there are populations differeing under these respects. This suggests the occurence of biological races.

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Zusammenfassung Beobachtungen über die Lage und die Struktur des Nestbaues bei dem GeschlechtLasius in natürlichem Milieu, erlaubte es genau definierte oekologische Ansprüche festzustellen. Eine Einteilkung der artspeziefischen Sitten des GeschlechtesLasius konnte an Hand der angwendten komplessen Bauart kund des gebrauchten Materials aufgestellt werden. In einer gegebenen Art können jedoch mehrere Völker miteinbegriffen sein die sich durch einen verschiedenartigen nestbau unterscheiden; dies lässt uns annehmen, dass wir vor verschiedenen biologischen Rassen stehen.

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Notes sur l'écologie et l'éthologie des espèces du genreLasius (Hymenoptera Formicid)

Résumé L'observation de l'emplacement et du mode de nidification des espèces du genreLasius dans leur milieu naturel a permis de mettre en évidence des exigences écologiques bien définies. De même, la complexité des techniques mises en uvre et le type de matérian employé lors de la construction des nids permettent de présenter un classement des murs des espèces du genreLasius. Une même espèce comporte des populations caractérisées par un mode de nidification différent, ce qui incite à penser que nous sommes en présence de races biologiques différentes.

     

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.     

Effets de la marée noire de l' ”Amoco Cadiz ” sur le benthos sublittoral du nord de la Bretagne

Effects of the “Amoco Cadiz ” oil spill on the sublittoral benthos, north of Brittany. Effects of hydrocarbons on the sublittoral macrobenthic communities have been observed through (1) studies of population dynamics of selected communities, conducted prior to the spill by the tanker “Amoco Cadiz ” in spring 1978 and (2) comparisons between the situation in summer 1978 with that in earlier years, with continuation of the observations in some selected sites. The effect of the spill has been selective, involving a limited number of species, mainly crustaceans, molluscs and the sand-urchinEchinocardium cordatum. The spill mainly affected communities on fine sediments and, to a lesser degree, those on mixed sediments. Notably, the destruction of the dominant populations ofAmpelisca, in areas of fine sands in the Bay of Morlaix, has led to a marked decrease of biomass and production. Moreover, repopulation will be difficult because of the isolation of such communities on the southern side of the English Channel. The effects evolved with time; after a phase of sharp and selective mortality, which did not last more than a few weeks, secondary effects on the recruitment of the remaining species do not seem to have occurred on a large scale. Nevertheless, a proliferation of polychaetes has been noticed.      

Influence comparée de l'(±)-acide abscissique,de la coumarine,de l'acide p-coumarique et de certains de leurs dérivés sur la croissance de la première feuille de blé

Summary The activities of (±)-abscisic acid and a number of compounds derived from p-coumaric acid and coumarin and their interaction with gibberellic acid in the control of the elongation of the first wheat leaf are examined. (±)-Abscisic acid strongly inhibits leaf growth in the presence as well as in the absence of gibberellic acid, but the inhibition is greater in the presence of gibberellic acid (3 g/l already have an observable effect). Among other compounds, only ferulic acid and coumarin significantly reduce leaf elongation, and they are effective only at high concentrations (1.44 · 10^-4 M/l).     

Contribution a l'étude de la construction du dome chezFormica rufa (II)

Résumé L'étude plus poussée des cloisons radiaires au sommet du dôme montre que l'hétérogénéité d'amassage dans un ou deux quadrants se produit même avec un croisillon très étroit permettant la libre circulation des Fourmis sur la majeure partie du sommet.Le phénomène de l'amassage hétérogène ne se produit plus si les cloisons radiaires ne vont pas jusqu'au sommet.Si on enlève les croisillons pour les replacer peu après dans la même position, l'amassage maximum se fait soit dans les mêmes quadrants, soit dans d'autres.Des cloisons circulaires concentriques sont rapidement comblées jusqu'au bord.Des cloisons rectangulaires verticales implantées à la périphérie du dôme, tangentiellement aux contours, donnent lieu à un amassage important de brindilles en amont, jamais en aval. L'auteur propose, pour expliquer ces faits, diverses hypothèses.On a étudié aussi les parcours individuels des Fourmis transporteuses de brindilles, au cours de leur ascension du dôme. La moitié portent les brindilles près du sommet, les autres les laissent à la périphérie.

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Summary A further study of the wooden cross-pieces put on ants dome shows the heterogenity of building material gathering in one or two quadrants, even in the case of a very narrow cross piece allowing the ants to go freely around.The gathering heterogeneity is suppressed if the boards of the cross piece let the hill's top free.If the cross piece is put away, to be replaced again a few minutes later the gathering heterogeneity is seen either in the same quadrants as before, or in others.Cincular concentrical boards are quickly filled of building material till to the edge.Rectangular vertical boards put at the dome periphery, tangentially to the circonference, elicit an important gathering above the board, never below.The individual courses of the ants on the dome have been studied also: 50% place their little twigs at the top, 50% at the periphery of the dome.

     

Evaluation comparée des effets subjectifs de la dextroamphétamine,du méthylphénidate et du placebo

The subjective effects of dextroamphetamine, methylphenidate and placebo were evaluated in 16 medical students during the period just prior to their final oral examinations. The subjects served as their own controls. The order of administration of the three medications for each student was randomized, and a double-blind technique was used throughout. A questionnaire method was employed for the collection of results, which proved to be a useful and effective means. It demonstrated that dextroamphetamine, methylphenidate and placebo were statistically different from one another with regard to their effect on efficiency of studying, fatigue, duration of sleep and appetite. There were also significant differences in the number of side effects caused by the three medications. The stimulants, however, did not increase the number of study hours, nor was their use recommended by the students when preparing for important examinations.     

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).