Cytochemical localization of the K+ regulation interface between blood and brain

Summary Phosphatase activity identified with Na⁺–K⁺-ATPase was localized at the basal surface of cerebral cortical capillary endothelium by perfusion with a p-nitrophenyl phosphate-strontium medium. The relationship of this to the blood-brain barrier to K⁺ is discussed.     

Cytochemical localization of the K+ regulation interface between blood and brain.

Phosphatase activity identified with Na+-K+-ATPase was localized at the basal surface of cerebral cortical capillary endothelium by perfusion with a p-nitrophenyl phosphate-strontium medium. The relationship of this to the blood-brain barrier to K+ is discussed.     

Cytochemical localization of monoamine stores in sheep thyroid gland at the electron microscope level

Resumen Se han estudiado los depósitos de catecol- e indolaminas en la tiroides de la oveja mediante una técnica citoquímica que permite la diferenciación entre ambos compuestos a nivel ultraestructural. Los abundantes mastocitos hallados en la glándula presentan granulaciones que contienen una catecolamina, que en base a estudios anteriores se identificó como dopamina. Las células parafoliculares en cambio, contienen serotonina en los gránulos citoplasmáticos. Dichos gránulos, cuya presencia ha sido vinculada con la de la tirocalcitonina, son por lo tanto capaces de almacenar la hormona y la 5-hidroxitriptamina. Los resultados citoquímicos se analizan conjuntamente con los obtenidos mediante la determinación química del contenido en aminas de la glándula.

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The kind cooperation of Dr.F. Iturriza and Dr.J. López Aranguren and the technical assistance of Mrs.Cristina Llorente andR. Castelli are gratefully acknowledged. Supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina and U.S. Air Force (AF-AFOSR 963-67).     

Cytochemical studies on histone moiety of an asynaptic mutant ofPhaseolus mungo

Zusammenfassung Die Wurzelspitzen und meiotischen Prophasezellen normaler und asynaptischer Pflanzen vonPhaseolus mungo wurden nach Azetylierung oder Desaminierung der Histone mit alkalischem Fastgreen, Bromphenolblau und Eosin Y gefärbt. Die asynaptischen Mutanten ergaben einen erhöhten Wert an labilen lysinreichen Kernhistonen.     

Effects of mycoplasma contamination on the radiosensitivity of rat glial cells

Résumé L'effet de la présence deM. laidlawii sur la sensibilité aux rayons-X des cellules provenant d'un glioblastome de rat a été étudié. Aucune différence significative n'a pu être mise en évidence entre la radiosensibilité des cellules infectées et celle des cellules saines. Ces résultats sont discutés en tenant compte des donnés bibliographiques.

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This research was supported by a grant No. CA-07368 from the National Institutes of Health. The culturing and identification ofM. laidlawii was made by Dr.L. Dienes.     

Blushing effect of some carbohydrates on the green algaDictyococcus cinnabarinus

Riassunto È studiato l'effetto di arrossamento provocato dall'aggiunta di alcuni zuccheri a colture sommerse dell'alga cloroficeaD. cinnabarinus. Questo effetto è dovuto alla formazione di cheto-carotenoidi, alla diminuzione delle clorofille ed alla degradazione dei cloroplasti. Le osservazioni al microscopio elettronico mettono in evidenza le variazioni della struttura dei cloroplasti.     

Studies on the interaction of the mistletoe lectin I with carbohydrates

Summary Carbohydrates and modified derivatives of D-galactose have been studied for their capacity to inhibit the hemagglutination of human erythrocytes by mistletoe lectin I. Inhibition data suggest that unmodified hydroxyl groups at the C-2, C-3, and C-4 position of the D-galactopyranosyl ring are essential for binding to the active sites of the lectin.     

Prey localization by surface wave ray-tracing: fish track bugs like oceanographers track storms

Surface-feeding fish accurately determine direction and distance to the center of a concentric wave stimulus, even if only a single, short lasting wave train is presented. It has been suggested that one cue used by these fish to localize the wave center is the distance dependent frequency modulation of the initial part of a wave stimulus. Here we show how the distance information contained in the fractional frequency change of a capillary wave group can be decoded. We suggest that wave source localization in surface-feeding fish in part is based on a principal similar to that used by oceanographers to track storms by the frequency change of forerunners of swell.     

Prey localization by surface wave ray-tracing: Fish track bugs like oceanographers track storms

Summary Surface-feeding fish accurately determine direction and distance to the center of a concentric wave stimulus, even if only a single, short lasting wave train is presented^1,2. It has been suggested that one cue used by these fish to localize the wave center is the distance dependent frequency modulation of the initial part of a wave stimulus^3,4. Here we show how the distance information contained in the fractional frequency change of a capillary wave group can be decoded. We suggest that wave source localization in surface-feeding fish in part is based on a principal similar to that used by oceanographers to track storms by the frequency change of forerunners of swell.     

Cytochemical changes of a glycocalyx of human placenta with maturation

Resumen En la superficie libre, en contacto con la sangre materna, del sinciciotrofoblasto de la placenta humana se observó un glicocáliz en el que se han caracterizado carbohidratos complejos, grupos sulfato y ácido siálico. En este glicocáliz se observaron cambios citoquímicos con la edad de la placenta. Con el microscopio electrónico, se describe la apariencia filamentosa del glicocáliz de placenta humana.