Intériorité et objectivation du subjectif en neurophysiologie

Résumé Le problème de l'intériorité, de la subjectivité, de la conscience n'est pas seulement un problème métaphysique ou un problème psychologique; il est susceptible d'une étude scientifique objective au plan de la neurophysiologie: celle-ci ne doit pas se contenter d' étudier analytiquement le fonctionnement cérébral, mais voir que la conscience résulte de la présence de l'individu à lui-mÊme dans certaines structurations de son cerveau et qu'un processus cérébral est ou non conscient suivant qu'il est ou non intégré à cette structure d'ensemble laquelle est bien plus développée chez l'homme en vertu de la complexification cérébrale qui rend possible la verbalisation du moi. Toujours le spirituel apparaÎt comme un aspect d'ensemble fonctionnel et non localisable de l'individu intégré.

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The problem of inferiority, of subjectivity, of conscience, is not only a metaphysical or psychological problem; it is susceptible to objective scientific study at the neurophysiological level. This study must not stop, however, at an analysis of cerebral function but must also recognize that conscience results from the self-being of the individual at himself in certain structures of his brain and that a cerebral process is or is not conscious according to whether or not it is integrated into the structure of the whole. This is best developed in man by virtue of the cerebral complexity which makes possible the verbalization of one self. The spiritual always appears as a functional, nonlocalizable aspect of the whole of the aggregate individual.

     

Etude cytochimique en ultrastructure de l'alvéole pulmonaire du rat

Résumé Les auteurs étudient par des techniques enzymatiques (phosphatases alcalines, phosphatases acides et adénosines triphosphatases) et des techniques autoradiographiques (par la glycine 3H), les cellules du revêtement de la paroi alvéolaire du rat Wistar. Après avoir rapporté les caractéristiques enzymatiques des différents types de cellules, les auteurs aboutissent à un certain nombre de conclusions concernant la cytophysiologie et le métabolisme des phospholipides au niveau du poumon.Cette étude qui fait suite à une étude histochimique et histo-enzymologique en microscopie optique, leur permet de penser que les pneumocytes granuleux ou cellules à inclusions lipidiques ou cellules alvéolaires de type II jouent un rôle particulier dans l'élaboration du surfactant. En effet, des inclusions lipidiques complexes ont été retrouvées dans les mitochondries; elles sont par ailleurs le siège d'une réaction positive par les déshydrogénases, elles incorporent précocement la glycine tritiée et possèdent une période constante de 55–56 Angströems. Les images de secrétion exocrine retrouvées permettent de penser que ces cellules synthétisent des phospholipides (au niveau des mitochondries) destinés à l'élaboration du surfactant. La positivité des A.T. Pases au niveau de leurs villosités traduit une activité de transfert énergétique au niveau des membranes.Il existerait donc deux types de figures lamellaires au niveau des cellules bordant l'alvéole: les unes sont situées dans les pneumocytes granuleux et ne sont pas positives aux phosphatases acides; elles sont surement à l'origine du surfactant. Les autres sans période caractéristique marquées par une réaction phosphatasique acide nette correspondent à du matériel phospholipidique phagocyté et sont situées dans les cellules alvéolaires ou endo-alvéolaires à activité macrophagique.

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Ultrastructural histochemical study of the rat pulmonary alveolus

Summary The alveolar cells of the rat have been studied autoradiographically (glycine 3 H) as well as with certain enzyme demonstrating methods (alkaline phosphatases, acid phosphatases and A.T. Pases). The enzymatic features of the different cell types are given and conclusions about the cytophysiology and the phospholipid metabolism in the lung are suggested.The authors think that the granular pneumocytes (or phospholipid inclusion cell or Type II alveolar cell) play a role in the surfactant elaboration. Complex lipid inclusion bodies are to be seen in the mitochondria, which are dehydrogenase positive, incorporate glycine 3H, and possess a constant structural period of 55–56 Å. The exocrine secretion figures suggest that these cells synthesize phospho-lipids in their mitochondria; these lipids are part of the surfactant. The positive A.T. Pases on the microvilli of type II alveolar cell are an indication for an active membrane transport.There are two types of lamellar bodies in the alveolar cells: the first occur in the granular pneumocyte; they are acid phosphatase negative and are certainly the source of the surfactant; the second occur in the alveolar macrophages; they do not exhibit a constant periodicity, they are acid phosphatase positive and are thought to represent engulfed phospholipids.

     

Le système neuro-sécrétoire caudal du téléostéen Jenynsia lineata

Résumé On décrit le système neurosécrétoire caudal de Jenynsia lineata. L'urophyse de cette espèce est un organe bien différencié, séparé de la moelle par une membrane méningée discontinue, et formé de fibres qui y arrivent après avoir constitué un pédoncule principal. Les fibres ne pénètrent pas par celui-ci, le font par les orifices de la membrane méningée.Dans l'urophyse comme dans les cellules neurosécrétoires du système, la neurosécrétion se colore à l'aldéhyde fuchsine après oxydation par le KMnO₄/ H₂SO₄; à l'hématoxyline chromique de Gomori elle se colore aussi, mais faiblement, et toujours après mordançage par de l'alun chromique dans le Bouin. On en discute les causes, par rapport aux données obtenues par d'autres auteurs.Il n'y a pas de cellules géantes, si caractéristiques du systéme neurosécréteur caudal d'autres Téléostéens. Les cellules neurosécrétoires du système sont petites et peu remarquables.Nous tenons à remercier le Dr. Juan H. Tramezzani de la lecture du manuscrit de ce travail, et des précieuses suggestions qu'il a bien voulu nous faire parvenir.     

Apport du TDM en imagerie multimodalité : le point de vue du physicien médical

The recent introduction of hybrid systems SPECT/CT and PET/CT in nuclear medicine, greatly improved the diagnostic accuracy for particular clinical indications, due to the possible attenuation correction of functional images and the availability of helpful anatomic information. The introduction of CT in the nuclear diagnostic process results in a significant increase of the patient dose. This increase should be justified and optimized considering both the clinical question and the CT settings available on these systems. The choice of CT settings directly affects the effective dose. It varies basically as the square of the tube voltage, linearly with the length of the scan and the product of the current by the rotation time of the tube. It is also inversely proportional to the pitch. For attenuation correction, the literature shows that it is possible to use a low CT tube current without significant effect on tumor FDG uptake or lesion size. Conversely low CT voltage must be used with caution, depending on the algorithm implemented in the CT hybrid device to transform CT Hounsfield units to the attenuation map at the appropriate energy. The radiation dose for anatomic correlation can be substantially lower than for diagnostic-quality CT. It is possible to reduce the patient's radiation dose by a factor of 2 or 3 by acquiring a low-dose PET/CT scan for anatomic correlation of adequate image quality if compared with diagnostic ¹⁸FDG PET/CT. Using specific CT settings, the effective dose can range 7.3–11.3 mSv depending on the patient weight and age.     

Cellules riches en glycogène dans l'épendyme du ventricule latéral du cerveau de rat

Summary The ependyma of the lateral ventricle of the rat brain was investigated at different ages from 20 days to adulthood.A particular cell type occurs in the external wall of the ventricle, where the proliferative subependymal layer is present. These cells found at all ages studied, are characterized by a high content of glycogen, and a structure different of typical ependymal cells.A large number of nerve endings is situated in close vicinity of these cells, either free in the ventricle lumen, or sometimes ensheathed in the cells. No synapse was found between these endings an the glycogen-rich cells.These glycogen-rich cells undergo several modifications with age: their glycogen content is reduced in the adult, and they acquire a few cilia and gliofilaments. It is suggested that they represent a transitory differentiation of the ependyma, functionally linked with the proliferative subependymal layer.

     

Le Jas d’en Biel 2, nouveau site gravettien du piémont est-méditerranéen des Pyrénées

The Corbières massif forms the lowest part of the Eastern Pyrenees, and as such is the easiest natural passage to connect the coastal plains of Languedoc and Roussillon in Southern France with those of Gironès and Barcelona in Northern Spanish Catalonia. This geographical situation confers on each of the sites discovered in this passage a role of milestone that can allow us to apprehend the dynamics of anthropic movements and relationships across these spaces. In 2007, the presence of a first Gravettian site in this Northern Pyrenean foothill was published: Jas d’en Biel 1. This discovery filled an “archaeological void” between the Gravettian sites of Languedoc and those of Spanish Catalonia. The discovery of a new site: Jas d’en Biel 2, 300 m from the first, reinforces the Gravettian presence in this region. The fact that the two sites present similar characteristics in terms of anthropic choices (solar orientation, proximity to a watercourse, lightness of the soil, protection from the wind, etc.) are all parameters that demonstrate the choices made by Gravettian men. The respective compositions of the lithic industries of the series do not show significant differences, allowing us to imagine a certain synchronism between the two sites. Burins are the most numerous tools, but at Jas d’en Biel 2 we find specimens close to the Raysse type that were absent from Jas d’en Biel 1. Jas d’en Biel 2, as well as its neighbor Jas d’en Biel 1, shows similarities with certain sites in Languedoc, such as Bois-des-Brousses, La Treille, La Verrière, the caves of Bize or La Crouzade. These are usually small deposits that belong to terminal moments of the Gravettian period. All these parameters point to similarities between the Languedoc sites and Jas d’en Biel 1 and 2. The geographical position of the Corbières massif allows us to consider the Jas d’en Biel sites as the last milestones of the Gravettian period upstream from the crossing of the Pyrenean passes, before the sites of the Serinyà region, such as l’Arbreda. Recent surveys carried out in the same valley of the Ravin d’en Saman have made it possible to locate and identify several other open-air settlements related to the Gravettian lato sensu. An analysis of intra- and extra-site characteristics will aim to understand the parameters that led men to settle in this micro-zone, as well as the reasons for this “concentration”.     

Le spermatozoide de Ophidion sp. (Poisson,téléostéen): Particularités ultrastructurales du flagelle

The spermatozoon of Ophidion sp. possesses an elongated nucleus 8 μm long, a short midpiece (0,6 μm), and a long flagellum (100 μm). The flagellar membrane extends in the form of two diametrically opposed sidefins. Evolving spermatids and spermatozoa are found in the lumen of the seminiferous tubes. The sections of flagella show filamentary and tubular elements disposed parallel to the axoneme microtubules. We have divided the flagella into three types. In type 1 the tip of the sidefins contains 20 to 30 filaments 5 run in diameter and between these and the axoneme 20 to 30 tubular elements 15 to 20 nm in diameter. Type 2 possesses a dense cytoplasm and a few tubular elements 10 nm in diameter disposed at the tip of the sidefins. Type 3 contains a cytoplasm which is not dense and in which we found polysaccharides and 1 to 8 tubular elements forming a palisade which lines the plasma membrane at the tip of the sidefins. We interpret these three types as three successive stages in the organization of the flagellum during spermiogenesis. Type 3 corresponds to the spermatic flagellum. These 10-nm-diameter tubules do not have the same chemical composition as the microtubules. Elements of the cytoskeleton serve as a support for the sidefins.     

Variations du taux d'adsorption du bactériophageϕ80 en rapport avec la résistance à la colicine B

Various mutants ofEscherichia coli selected by colicine B show a wide range of resistance spectra towards colicines B, I and V, phages T₁ andq 80, by mutation in locusbt ₁. Such relations of specificity of resistance seem to result from quantitative variations in the adsorption rate. Indeed, the ability to fix the phage 80, or its derivative the plaque-forming transducing phage 80pt ₁, decreases in correlation with the extent of the spectrum of cross-resistance in the mutants studied. It is never completely abolished even in mutants apparently resistant to this phage, as shown either directly by titration of infective centers or indirectly by the rate of transduction.     

Isorthid AE (Brachiopoda) du dévonien inférieur du massif armoricain

Three species of Isorthidae are described in the Lower Devonian of the Armorican Massif. Two of them were hitherto badly known, being never adequately described nor figured: Isorthis (Protocortezorthis) miloni from the Gahard Formation (Gedinnian) and Isorthis (Protocortezorthis) trigeri from the Saint-Céneré Formation (Gedinnian-Siegenian). Isorthis oehlertiSolle, 1976 is considered as a synonym of Isorthis (Protocortezorthis) trigeri. The geographic distribution of these species allows to corroborate that until the top of the Lower Devonian (top of Le Faou Formation), two provinces with different faunal associations exist in the Armorican Massif.     

Réflexions sur l'état actuel de nos connaissances phytosociologiques en Afrique du Nord

Sans résuméReçu par la rédaction le 1.XI.1953.     

Variation de l'angle sphénoïdal du crâne humain en fonction du vieillissement

The degree of the cranial base flexion is a major parameter in the study of the evolution of verbal communication in mankind. The variability of this area among modern humans has received little attention. In the present study, a sample of 330 modern human skulls have been used to characterize the changes in the angle of the cranial base flexion with age, and its possible relationships with gender and ethnic origin. Statistical analysis of the results show significant changes with age. Two conclusions emerged: i) the debate regarding Neandertal speech should also consider the effect of age on the cranial base; and ii) the sphenoidal angle can be used as an ageing criterion in forensic and anthropological studies.