Ultrastructure du lobe postérieur de l'hypophyse du rat et ses modifications au cours de l'excrétion de vasopressine

Résumé Le lobe postérieur de l'hypophyse a été examiné sur coupes ultrafines chez 45 rats (24 normaux, 17 déshydratés respectivement 1, 2 et 4 jours, et 4 anesthésiés à l'éther), après fixation au glutaraldéhyde ou selon la méthode de Karnovsky, post-fixation osmiée et double contraste à l'acétate d'uranyle et au citrate de plomb. Des fibres neurosécrétoires sombres et claires sont reconnaissables, mais les données manquent encore pour interpréter cette différence. Des densifications juxta-membranaires sont observées dans les terminaisons neurosécrétoires là où se trouvent des amas de microvésicules. Des fibres neurosécrétoires traversent parfois des pituicytes; il est aussi souvent observé des fibres, chargées de granules, libres dans un espace péricapillaire. Les espaces péricapillaires, ramifiés en tous sens loin des vaisseaux, développent une large surface de contact avec les extrémités nerveuses et les prolongements de pituicytes.Dans des conditions techniques bien contrôlées, la déshydratation n'entraîne pas de modifications appréciables des granules de neurosécrétat après 24 h. Ensuite les granules sont diminués en nombre, de façon très considérable le 4e jour; mais les granules restants ont un contenu dense normal; jamais il n'a été observé d'aspects de granules vides . Après anesthésie prolongée à l'éther, il n'y a aucune modification visible ni du nombre, ni de la densité des granules. Ces observations sont discutées quant au mécanisme de l'excrétion de vasopressine; elles sont en faveur de l'existence de deux pools hormonaux, l'un libre et rapidement disponible, l'autre plus fortement lié et certainement contenu dans les granules jouant le rôle de réserve. Toutefois un mécanisme d'exocytose granulaire ne peut être formellement exclu.

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Ultrastructure of the rat's hypophysial neural lobe and it's changes during vasopressin release

Summary Hypophysial neural lobes of 45 rats (24 controls, 17 dehydrated resp. 1, 2 and 4 days, and 4 ether anesthetized) were fixed either with glutaraldehyde or according to Karnovsky and post-fixed in osmium tetroxyde; ultrathin sections were stained by uranyl acetate and lead citrate. Dark and clear neurosecretory fibres were observed, but sufficient data are still lacking for a valuable interpretation of these aspects. Juxta-membraneous densifications are visible in limited areas of neurosecretory terminals where clusters of microvesicles are present. Neurosecretory fibres happen to be completely encircled by pituioyte cytoplasm; fibres loaded with elementary granules are frequently encountered running free in a pericapillary space. Pericapillary spaces stretch out branching far away from vessels, resulting in a widespread contact with nerve terminals and pituicyte processes.In accurately controlled technical conditions, dehydratation does not result in any noticeable change of neurosecretory granules after 24 h. A decrease of the number of granules follows and is extremely conspicuous after 4 days; though, remaining granules keep a normal dense content, and aspects of empty granules have never been observed. After prolonged ether anesthesia, no visible change either in number or electron density of granules was observed. These findings are discussed in consideration of the mechanism of vasopressin release; they support the hypothesis of two hormonal pools, one of which would be free and rapidly available for release, the other being more tightly bound and certainly located in granules representing a storage site. Though granular exocytosis cannot be absolutely excluded.

Travail effectué avec l'aide, en matériel et en assistance technique, du Centre National de la Recherche Scientifique. — Nous remercions particulièrement Mme J. Bottini pour son aide précieuse dans la préparation du manuscrit et Mr. B. Dutillet pour sa participation aux contrôles en microscopie optique.     

Effets de la mise en eau du réservoir Desaulniers (Territoire de la Baie de James) sur le zooplancton d'une rivière et d'une tourbière reticulée

This paper presents the results of an investigation which lasted three years, on the effects of impounding a river on its zooplankton community. Forty zooplankton samples were collected from the Desaulniers River and from a string bog (53°35N, 77°35W) in 1976 before impoundment. Sampling was also conducted in 1977 (331 samples) and 1978 (153 samples) during and after impoundment. The population dynamics of zooplankton show different patterns in 1977 and 1978. The main impacts of impoundment on the river and the bog communities are the increase of the population density, particulary of Rotifera and Copepoda, the increase of the number of species of Rotifera and the increase of the diversity indices based on numbers and biomass. These changes are observed at each sampling station. The total biomass increases in lotic stations but decreases in the string bog because the density and the biomass of Cladocera increases in the river but drops in the bog. Results are compared to those obtained in natural lakes and bog of the same area and to those published in other studies.

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Effets de la mise en eau du réservoir Desaulniers (Territoire de la Baie de James) sur le zooplancton d'une rivière et d'une tourbière reticulée

     

L'effet de β-mercaptoéthanol et de l'urée sur la structure du phragmoplaste

Résumé Les fibrilles constitutives du phragmoplaste sont de nature protéique. L'action du-mercaptoéthanol permet de conclure que ces protéines sont liées par des ponts S-S. En présence d'urée, la structure du phragmoplaste est détruite, ce qui indique l'existence de liaisons hydrogènes.

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Zusammenfassung Unsere Arbeit führt zu folgenden Resultaten: 1. Die im Phragmoplast befindliche Faserstruktur besitzt einen Eiweißstoffcharakter. 2. Der Effekt des-Merkaptoäthanols gestattet die Annahme, daß die Proteine mit S-S-Brücken verbunden sind. 3. Bei Anwesenheit von Harnstoff wird die Phragmoplaststruktur zerstört, was für das Vorhandensein von H-Brücken spricht.

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Boursière de la Fondation Rockefeller     

Cytologie comparée deMus (Leggada) Minutoides minutoides Smith D'afrique du Sud et d'une forme voisine de l'Angola

In the pigmy-mouse,Mus (Leggada) minutoides minutoides A. Smith, 1834 from South-Africa, the author (1964) has described a chromosome complement of 18. The 16 autosomes are metacentric. TheX is big and metacentric, theY short and acrocentric. Owing to the fact that, at the first metaphase, both sex-chromosomes are united through a true chiasma, it was supposed that theY was primitively of the translocated type (TR), like theX, and that an intercalary deletion had destroyed the main part of the autosomic segment of theY, leaving only a small telomeric piece necessary for the formation of a chiasma. This hypothesis is confirmed by the analysis of pigmy-mice from Angola which morphologically are very like but not identical to the South-African form. The single chromosomic difference is the shape of theY which is big and submetacentric, also of theTR type.     

Fonctions histoenzymatiques lors de l'évolution et de la lutéolyse du corps jaune de la lapine

Résumé Trente cinq enzymes sont recherchées lors de l'étude comparative de la lutéinisation et la lutéolyse. Vingt six sont histochimiquement décelables dans les corps jaunes gestatifs leur permettant de stocker et métaboliser glucides, corps gras, nucléotides, amines, phosphates, sulfates et d'autres métabolites. Les activités importantes des enzymes de la voie des pentoses, des diaphorases et de la stéroïde 3 ol DH témoigneraient d'une stéroïdogenèse active. Les cellules lutéiniques thécales semblent histoenzymatiquement mieux pourvues au début de la luteinisation; les cellules lutéiniques granuleuses le sont pendant les stades ultérieurs.La lutéolyse est marquée par une diminution de la plupart des activités enzymatiques. Les activités tant qu'elles existent, sont topographiquement limitées (ilôts actifs extra lutéaux) et surtout métaboliquement restreintes. L'équipement enzymatique des structures lutéales très involuées suggère plutôt qu'une stéroïdogenèse même résiduelle des processus typiques et une activité des éléments conjonctifs (fibrillogenèse).

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Histoenzymatic functions of the evolution and the luteolysis of the corpus luteum of the rabbit

Summary 35 enzymes were investigated in the course of a comparative study on the luteinisation and luteolysis. 26 of them were found in the corpora lutea during gestation. They were able as a consequence to stock and the metabolize glucides, lipides, nucleotides, amines, phosphates, sulphates as well as other metabolites. The strong activities of the pentose shunt's enzymes, of the tetrazolium reductases and ⁵ 3 OH-steroide DH indicated most probably an active steroidogenesis. The theca-luteinic cells appeared having a stronger histoenzymatic activity in the beginning of the luteinisation; the granuloso-luteinic cells showed a stronger activity in the later stades.The luteolysis is characterized by a decrease of the activity of the preponderant number of the enzymes mainly in the degenerated luteal cells. The enzymes activities as far as such existed were topographically limited (active extraluteal islands) and restricted mainly in their metabolizing possibilities. The author's results suggested as more probable the existence of a process of lysis and an activity of the connective tissue elements (fibrillogenesis) than a steroidogenesis, even though in a residual or terminal form.

     

Analyses de sols et matériaux de termitières du Congo Belge

Summary This work deals with analysis of soils from mounds belonging to the following Termites:Bellicositermes bellicosus Smeathman,Bellicositermes natalensis Haviland,Amitermes unidentatus (evuncifer) Silvestri,Nasutitermes ueleensi Sjöstedt andCubitermes fungifaber Sjöstedt. The following data were collected: texture, organic carbon and nitrogen rates, loss by calcination,pH and colour of dry soil.In order to compare the different materials, samples were always taken in the mounds and on the adjacent land. The native building materials differ with the Termite species.As for theMacrotermitinae which take soils from the depth, the texture is finer in the soils coming from the mounds than in the adjacent soils; there is no difference forAmitermes mounds; but for the mounds ofCubitermes andNasutietermes, the rate of fine elements is greater than in the surrounding soils which contain an important amount of iron oxyde concretions.The buildings ofMacrotermitinae are poorer in organic matter than the adjacent land, but the contrary occurs with the mounds ofCutitermes, Nasutitermes andAmitermes.

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Zusammenfassung Diese Arbeit handelt über die Analyse von Termitennesterböden welche folgenden Arten angehören:Bellicositermes bellicosus Smeathman,Bellicositermes natalensis Haviland,Amitermes unidentatus (evuncifer) Silvestri,Nasutitermes ueleensis Sjöstedt undCubitermes fungifaber Sjöstedt.Es wurden analysiert: Textur, organischer Stickstoff und Kohlenstoffgehalt, Aschgehalt,pH und Farbe des trockenen Bodens. Um einen Vergleich zu ermöglichen wurden jedesmal Proben entnommen einerseits in den Termitennestern und andererseits in den angrenzenden Böden. Der Ursprung des Baumaterials ändert mit der Termitenart. Bei denMacrotermitinae welche die Materialien aus der Tiefe entnehmen, stellt man fest daß die Textur der Termitennester feiner ist als in den angrenzenden Böden; im Falle derAmitermes bestehen keine Texturunterschieden. Die Nester derCubitermes undNasutitermes sind reicher an feineren Elementen als die benachbarten Böden welche stark mit Lateritkonkretionen angereichert sind. Die großen Gebäude derMacrotermitinae sind viel ärmer an organischem Material als die Außenböden; das Gegenteil wird beobachtet bei den Nestern derCubitermes, Nasutitermes undAmitermes.

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Ingénieur agronome Lv. Licencié en Sciences zoologiques Lv. Assistant à la Division d'Agrologie de l'INÉAC.     

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.     

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.     

Le Paléolithique supérieur du plateau de Musashino et les hauteurs de Tama aux alentours de Tokyo

The Upper Paleolithic at the region of Tokyo that itself called also the Japanese Preceramic age that possesses a large number of excavations and those studies during the dawn of Paleolithic study in this country. The Preceramic age or the Upper Paleolithic has been raised the curtain by the discovery of a piece in obsidian, in 1949, in the loam of Kantô, at Iwajyuku site. We explain above, on the stratigraphy, the chronology and the situation and the evolution of site around Tokyo. It is a region to the highest density of the Upper Paleolithic sites in the archipelago of Japan and the systematic excavation according to the stratigraphy of loam formation has been done for the first time in the country. The authentic chronology has been proposed to the years 60s that based on the discovered lithic industries on the plateau of Sagamino and Musashino. This chronology was used for a long time that it made a role like a norm for the whole country. Not only, after again an accumulation of the research until the present, we understand the different periodic activities between the Tama hills, the plateau of Musashino, the plateau of Sagamino, the North of Kantô district and the plateau of Simôssa. Of course, there is a complex circumstance that the apparition and the disappearance of various types of lithic instruments are different, and every type tools are not universal around Tokyo area, in the district of Kantô. The final of Upper Paleolithic on the archipelago of Japan divides extensively in two parts East-west that the East of Japan is characterized by the well-organized aspect microlithic tendency and the west is characterized by the trend of microlite, trapeze and tool on transverse blade. In such general tendency, the region of Kantô is located therefore in the center on the archipelago of Japan that it showed sets of every different time.     

Les crocodiliens fossiles du Jurassique moyen et supérieur de Bourgogne

The middle and upper Jurassic limestones of Côte-d'Or (France) contain some crocodilian remains referred to the genera Teleidosaurus, Steneosaurus, and Metriorhynchus. Their preservation allows a determination at a specific level only for Teleidosaurus gaudryi (Lower Bathonian), Steneosaurus larteti (Upper Bathonian), S. heberti and S. cf. intermedius (Middle Oxfordian). Sedimentological evidence shows that Steneosaurus and Teleidosaurus are found either in very pure limestones sedimented on an epicontinental platform, in a very calm and sheltered environment, in the intertidal or supratidal zone, often associated with subrecifal facies; or in the infratidal zone, more distinctly subjected to open-sea influences (deposits, currents, reworkings). Specialised Metriorhynchidae such as Metriorhynchus are completely absent in the former type of sediment but are present in the later. One may infer, considering anatomical evidence (no dermal armour, caudal fin…) that Metriorhynchus was better adapted to swimming and rather lived in the open sea. The Teleosauridae preferred very shallow or temporarily emerged places, where they could move around thanks to their limbs which were still capable of walking on land; however, this did not prevent them from going out to sea, where the habitats of both families probably largely overlapped.     

Epidémiologie,diagnostic et pronostic du cancer de la prostate

Prostate cancer is the most frequent of cancers and represents the third leading cause of death by cancer, for men over 50 years, in France and Europe. The incidence decreases since about ten years. Mass screening is not recommended. Individual early diagnosis is based on a yearly exam including Prostate Specific Antigene (PSA) blood test and a digital rectal exam. The target for this diagnostic approach are men from 50 to 75 years with more than 10 years of life expectancy. A series of prostatic biopsy are carried out in case of clinical and/or biological prostate cancer suspicion. The additional examinations recommended in the assessment of extension of prostate cancer with intermediate and high risk are: MRI, bones scintigraphy, scan CAP (metastatic stage), and sometimes Choline PET-CT. Curative treatments are proposed to men with a probability of survival over 10 years, suffering from localized or locally advanced cancer. Gold standard treatments are: active surveillance, radical prostatectomy, brachytherapy, radiotherapy alone or with surgery and/or hormone therapy. Experimental treatments of localized tumors are: focal treatments (phototherapy dynamic, high intensity focused ultrasound). For the more advanced forms, the interest of early chemotherapy is extensively studied.     

Le cancer du testicule : facteurs de risque génétiques et environnementaux

The incidence of testicular cancer (TC) has a distinct geographic distribution but is increasing in most countries, including France. The most likely origin of TC is a lack of normal germ cell differentiation in the foetal testis. The maintained immature germ cells could proliferate after puberty to induce testicular tumor. Because of its frequent association with cryptorchidism and infertility, TC could be part of the testicular dysgenesis syndrome. The role of genetic factors is suggested by the frequency of familial TC cases, but no responsible gene has been clearly identified until now. Among the various studied genes, those regulating the KITLG/KIT pathway involved in primordial germ cell proliferation seem to play an important role. Studies made in immigrants and twins suggest the influence of environmental factors on the origin of TC. Hormonal deregulation occurring during prenatal life or puberty could facilitate the development of TC. However, the role of exogenous substances acting as endocrine disruptors has not been demonstrated yet.