Evolution des flavonoides au cours de la croissance des bractees de Poinsettia

The changes in flavonoids were studies during the growth of Poinsettia bracts. Pelargonidin glycosides appeared after cyanidin glycosides; the 3-rutinoside after the 3-monoglucoside. The 3-mono-glucosides were predominant at all times. The bracts contained kaempferol and quercetin, both as aglycones and glycosides. There was no direct relationship between the pathways of flavonol and anthocyanin biosynthesis, but two separate pathways corresponding to the 4′-monohydroxylated- and 3′,4′-dihydroxylated-, flavonoids. Flavanonols and isoflavones were detected but not characterized.     

Evolution des activités enzymatiques dans le tractus digestif au cours de la vie larvaire de la sole. Variations des protéinogrammes et des zymogrammes

The activities of digestive enzymes were studied during the course of larval development (from hatching to 30 days) in the sole, Solea solea. No glycosidase activity was present, but alkaline proteolytic activity increased from hatching to day 5, then decreased until day 15. In the acid range, proteolytic activity was relatively stable from the 10th to the 30th day. There were also changes in the number of esterase-like isozymes which increased between day 20 and 30, with minimum activity observed during metamorphosis.     

Ultrastructure des capillaires dans le télencéphale du poulet au cours de l'embryogenèse et de la croissance postnatale

Resumé Une étude en microscopie électronique de la structure des capillaires et des formations cellulaires qui les entourent a été faite au niveau du télencéphale, chez le Poulet, au cours du développement embryonnaire et de la croissance postnatale.L'endothélium capillaire est présent au premier stade embryonnaire étudié (embryon agé de 8 jours). La membrane basale se différencie vers le dix-neuvième jour du développement embryonnaire, et elle est précédée de l'apparition des péricytes qui restent inclus définitivement dans sa structure.L'espace extracellulaire dans l'environnement des capillaires, constitué par de larges lacunes au cours du développement embryonnaire, se réduit dès l'éclosion à des intervalles de 150–200 Å de diamètre. Les astrocytes et leurs prolongements (pieds vasculaires) atteignent leur complet développement, et entourent totalement le capillaire, vers le vingtième jour de la croissance postnatale.Nos observations mettent en évidence la relation étroite existant entre le développement des structures gliales péricapillaires et l'apparition de certains mécanismes du système de la barrière hémo-encéphalique chez le Poulet.

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Ultrastructure of the capillaries in the developing telencephalon of the chicken

Summary An electron microscopical study was made of the structure of the capillaries and of the surrounding cell formations in the chick telencephalon, during embryonic development and postnatal growth.The capillary endothelium is present in the embryonic stage first studied (i. e. the 8-day old embryo). The basement membrane differentiates about the nineteenth day of embryonic development, and it is preceded by the appearance of the pericytes which are finally included in its structure.The extracellular space in the vicinity of the capillaries, made of large gaps during the embryonic development, is confined from hatching time to intervals 150–200 Å diameter. The astrocytes and their processes (vascular feet) reach their complete development, and entirely surround the capillaries, on about the twentieth day of the postnatal growth.Our observations reveal the close connection between the development of the pericapillary glial structures and the appearance of some mechanisms of the blood-brain barrier system in the chick.

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Les auteurs remercient Madame R. Hatier de son excellente collaboration technique.     

Place de la TEP au FDG dans le bilan des épilepsies pharmacorésistantes

The work-up of drug-resistant partial epilepsy is intended to localize epileptogenic foci in the purpose of a possible surgery. We aimed to assess the role of fluorodeoxyglucose Positron Emission Tomography (FDG PET) in this scope. This study involved 34 patients who underwent brain FDG PET, with a final diagnosis in 21. The value of FDG PET for lateralisation and localisation of the epileptogenic focus was evaluated by a blinded interpretation, and compared with the value of standard investigations. The impact of FDG PET was assessed by the means of a questionary intended for the neurologist in each case. All the epilepsy types together, FDG PET lateralised and localised the foci in 65 and 47% of the 34 subjects respectively. Among the 19 subjects with final diagnosis (patients with bilateral foci excluded), lateralisation was correct in 84% and localisation in 63% (and the values were greater for temporal epilepsy than for extratemporal foci). PET frequently provided additional information compared with MRI, but not with EEG. FDG PET was useful in 82.5% of cases (confirming management in 65% and changing it in 17.5% of the patients). Our experience corroborated the value of FDG PET for lateralisation and localisation of epileptogenic foci, and its role in case of normal MRI. However, FDG PET appears as a confirmation tool rather than an examination resulting in a change in management rate.     

Synthèse des RNA au cours de la germination du radis

RNA synthesis in radish is studied during the first stages of germination. The radish seeds allowed to germinate in the dark, on distilled water, synthesize ribosomal RNA and accumulate a particular RNA, not incorporated in ribosomes. The results of ³²P incorporation in RNA of radish seedlings indicate a progressive formation of ribosomal RNA. Two species of rapidly labelled RNA are synthesized. With labelling time, their chromatographic behaviour on MAK columus evolves, while their electrophoretic characteristics remain stable. It is assumed that these two species are involved in ribosome formation. In vivo experiments with chloramphenicol support this conclusion. RNA which accumulates during germination, could be a particular type of ribosomal RNA which could be enable, under the definite culture conditions, to enter into ribosomal structures.     

Remarques sur le métabolisme de l'acide acétique chez la levure au cours de la sporulation

We have noticed important metabolic modifications during the first 15 hours of the sporulation process of yeast in contact with acetic acid. Carbohydrate reserves, dry weight and proteins increase. On the other hand, the activity of fumarase and isocitritase in cell homogenates are hardly altered. The results prove true the hypothesis according to which the metabolism of acetic acid is altered during sporulation.

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Zusammenfassung Beträchtliche metabolische Veränderungen wurden bei Hefe, während der fünfzehn ersten Stunden der Sporenbildung unter Zugabe von Essigsäure, beobachtet. Der Kohlenhydratenvorrat, die Trockensubstanz und der Proteingehalt nehmen zu. Die Aktivität der Fumarase und Isocitritase wird kaum verändert. Dadurch wird die Annahme bestätigt, daß eine Abweichung des Metabolismus der Essigsäure während der Sporenbildung stattfindet.

     

Evolution des glucides intratissulaires au cours de la néoformation des bourgeons par des explantats racinaires de Cichorium intybus cultivés in vitro

Variation of intratissular carbohydrates during bud formation in root explants of Cichorium intybus cultivated in vitro .
During the cellular activation that begins with excision of root explants from Cichorium intybus L. var. Witloof cv. Zoom cultured in vitro, hydrolysis of fructose polymers, in particular of the polyfructosans (inulin) takes place. The products of degradation are used to cover the energetic needs connected with the increase of the mitotic activity. After day 2 the intracellular carbohydrates (sucrose and reducing sugars) develop differently according to further development of the explants. When growth of unorganized callus is favoured and organ formation inhibited by medium supplemented with auxin, fructose is accumulated; but under bud-forming conditions it is the amount of sucrose that increases. These differences were most notable between days 3 and 10 in culture, the period during which primordia occurred in the shoot-forming callus     

Apports de la biologie dans le diagnostic des démences

Since 2007, the combined dosage of three biomarkers in the cerebrospinal fluid has been considered an essential component of procedures to help establish a diagnosis of Alzheimer’s disease (AD). These biomarkers include total-Tau proteins, phosphorylated variants of Tau and amyloid-beta peptides. Their levels are altered early during the course of AD but they are not useful for a differential diagnosis of other dementing disorders. Perspectives therefore focus on finding plasmatic biomarkers and developing new biomarkers that would aid discrimination between dementing disorders.     

Etude du phytochrome detectable,in vivo dans les graines de Cucurbita pepo L. au cours des differentes phases de la germination

Summary In dry gourd seeds all the phytochrome is in the P_fr form. The increase of phytochrome content from the beginning of hydration involves two phases, A and B, in the embryonic axis as well as in the cotyledons. Cycloheximide does not prevent the appearance of P_r during phase A. We assume that P_r is gradually released from an inactive complex. On the other hand phase B is inhibited by cycloheximide; this could mean that a de novo synthesis of P_r occurs.Some experiments indicate that the phytochrome which is localized in the embryonic axis may be involved only in the germinating process.The phytochrome which is synthesized during phase B disappears when the seeds are irradiated with red light, while the original phytochrome does not.According to our data it seems necessary to lay down a new and precise definition of the germination process.     

Priorités dans le domaine de la santé au Québec

The reform of health services in Quebec, of which the most important stage was the creation of the Department of Social Affairs and the Quebec Health Insurance Board, has solved certain problems such as the inaccessibility to care because of the cost, the paucity of medical personnel and the excessive increase in the cost of the services offered to hospital patients. A critical analysis of both the reform and its practical consequences points to certain conclusions which, far from rejecting the principle of the reform, indicate none the less various possibilities for reorienting its priorities. Observing the rate of recourse to health services as well as the attitudes and conduct of health professionals have helped us to identify the causes of certain tendencies inspired by the incentives inherent in the reform. The organization of health services in Quebec must be oriented toward new priorities: the prevention and treatment both of environmental diseases and diseases associated with ageing plus the definition of a global approach to public health.     

Le rôle des exploitations minières de la région d’Autun dans la constitution des collections paléontologiques

The birth of the oil shale industry, in the Autun basin (Saône-et-Loire, department in Burgundy), at the beginning of the 1830s, corresponded to a time during which the scientific progress in geology and paleontology was quite fast-paced. The development of the schist industry happened at a time when landmark works were published such as those by Louis Agassiz or Adolphe Brongniart. These scientists relied upon the on-going findings in the Autunois area. An outstanding dynamics was on its way. It brought about the updating of many samples sparking off important paleontological studies. A remarkable coordination set up between the industrial workers of the schist industry, the local scholars on the one hand and the National Museum of Natural History in Paris on the other hand. There resulted from it a frequent if not constant interest in the discovery of the fossils that the layers of schists – exploited with the aim of obtaining oil used as a quaffing product – can contain. This dynamics kept going on till the beginning of the 19th century. It was carried out by outstanding personalities such as Bernard Renault or Auguste Roche who were at the origin of the first collections gathered by the Society of Natural History in Autun, founded in 1886. But then, the findings were made rare. The mechanization of the chopping down and crushing of the schist did not any more offer the suitable conditions to discover new specimens. Anyway, the accumulated collections are already considerable and make of the Autunois one of the major places of great French paleontological progress in the years 1870 and 1880.     

La place des protheses de verge dans le traitement de la maladie de La Peyronie

In Peyronie’s disease, a penile curvature makes sexual intercouse painful or impossible. Surgery is a treatment option after medical treatment failure. The aim of surgery is to restore an erection allowing sexual intercourse. Beside corpus cavernosus modeling procedures, penile prosthesis implantation (i.e.,semi-rigid, inflatable, orimplants) is rarely indicated. Such procedures should be based on erectile response to intracavernous injection and penile and corpus cavernosus anatomy.     

Modalités d'infection des larves deLeptinotarsa decemlineata parBeauveria bassiana au cours de la mue

Résumé L'étude histopathologique des modalités d'infection des larves deL. decemlineata parBeauveria bassiana au cours de la mue a été réalisée pour mettre en évidence les phénomènes pathologiques particuliers se manifestant au cours du renouvellement du tégument en présence d'une infection cryptogamique. Les techniques histologiques et la microscopie électronique à balayage permettent de suivre la pénétration du champignon chez les larves en prémue, montrant les modalités d'invasion du liquide exuvial et de contamination secondaire du tégument en formation. L'étude des perturbations de la mue chez les larves contaminées souligne l'importance des zones de déchirure du nouveau tégument, non seulement comme voies préferentielles de pénétration des éléments mycéliens multipliés dans le liquide exuvial, mais aussi comme portes d'entrée pour les bactéries. Ces observations apportent une contribution originale à l'étude des mécanismes pathologique provoquant une mortalité différée des insectes.

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Summary The histopathological study of the infectious procces of larvae ofL. decemlineata byB. bassiana was carried out on moulting larvae infected experimentaly. The experiments showed that the differed mortality among this type of insect with a short larval cycle, interrupted by close successive moults, depends on the interaction between the penetration of the fungus and the throwing out of the infected integument. The penetration ofB. bassiana into the larvae at the ecdysial stage was caracterized by invasion of the moulting fluid: infection of the integument in formation and hypodermical histolysis. The disturbance of the tissues was followed by integumental ruptures of the young larva during the emergence from the ecdysis. A double infectious process, of larvae in the moulting stage was shown. On one hand, an infection of the intermoult-integument occurred. On the other hand, the injured regions were routes for massive penetration of hyphal bodies in the hemolymph. Such injuries, also allowed the entrance of bacteria from the moulting fluid to the hemolymph and then caused a septicemia. Larvae after ecdysis, with blackened integumentary patches or with cicatrices, showed hyphal bodies in the hemolymph, which may explain the differed mortality caused by the fungus.