White leaf disease ofCynodon dactylon Pers., a mycoplasmal disease in India

Summary White leaf disease of Bermuda grass (Cynodon dactylon Pers.) has been reported from a few countries to be caused by a mycoplasma-like organism. We have tried to observe the causal agent in white leaf diseased plants ofC. dactylon collected near Varanasi. Both tetracycline treatment and electron microscopy have revealed the presence of mycoplasma-like bodies in phloem cells of the diseased plants.     

Tissue culture ofNigella sativa I. The behaviour of nucleus

Zusammenfassung In Kallusgewebekulturen vonNigella sativa nimmt mit der Zeit der Anteil der diploiden Zellen ab, während sich die Anteile von aneupliden, von 2n abweichenden Zellen vermehren.     

Gibberellin-sugar interaction regulating the growth habit of bermudagrass (Cynodon dactylon (L) Pers)

Zusammenfassung Saccharose und Glucose unterbinden die von schwachem Licht erzeugte negativ geotropische Kurvatur von Bermudagrasausläufern. Gibberellinsäure erzeugt eine Umkehrung dieses hemmenden Effekts.     

Tissue protection against oxidative stress

We used an enhanced luminescence technique to study the response of rat tissues, such as liver, heart, muscle and blood, to oxidative stress and to determine their antioxidant capacity. As previously found for liver homogenate, the intensity of light emission (E) of tissue homogenates and blood samples, stressed with sodium perborate, is dependent on concentration, and the dose-response curves can be described by the equation E=a·C/exp(b·C). Theb value depends on the antioxidant defence capability of the tissues. In fact, it increases when homogenates are supplemented with an antioxidant, and is correlated with tissue antioxidant capacity, evaluated by two previously set up methods both using the same luminescence technique. Our results indicate that the order of antioxidant capacity of the tissues is liver>blood>heart>muscle. Thea value depends on the systems catalysing the production of radical species. In fact, it is related to the tissue level of hemoproteins, which are known to act as catalysts in radical production from hydroperoxides. The equation proposed to describe the dose-response relation is simple to handle and permits an immediate connection with the two characteristics of the systems analysed which determine their response to the pro-oxidant treatment. However, the equation which best describes the above relation for all the tissues is the following: E=·C/exp(·C). The parameter assumes values smaller than 1, which seem to depend on relative amounts of tissue hemoproteins and antioxidants. The extension of the analysis to mitochondria shows that they respond to oxidative stress in a way analogous to the tissues, and that the adherence of the dose-response curve to the course predicted from the equation E=a·C/exp(b·C) is again dependent on hemoprotein content.     

A method of mass tissue culture in bacteriological culture dishes

Zusammenfassung Eine Methode der Massen-Gewebezüchtung in Petrischalen, geeignet für Viruszüchtung und für chemische Analysen, wird beschrieben, mit welcher, wenn ein gemeinsames, zusammenhängendes Plasmagerinnsel mit Zusatz von Embryonalextrakt und Amnionflüssigkeit als Züchtungsmedium benutzt wird. Ein besonders rasches, dichtes Kulturwachstum kann so leicht erzielt werden. Mikroskopische Beobachtung der Zellen ist bei 400facher Vergrösserung, im gewöhnlichen und im invertierten Mikroskop, leicht möglich.

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Aided by grants from the Masonic Foundation for Medical Research, Human Welfare and the U.S.P.H.S.     

Amphibian organ culture

Résumé Les auteurs passent en revue les problèmes étudiés et les méthodes utilisées jusqu'à ce jour pour la préparation des tissus des amphibiens en culture organotypiques. Ils envisagent en outre les possibilités qui s'offrent aux recherches futures.     

Suspension culture ofNigella sativa

Summary In suspension culture 91% free cells ofNigella sativa was obtained inWhite's medium supplemented with casein hydrolysate, inositol and adenine. Ploidy distribution pattern was similar in cell clumps of different sizes and free cells. Chromosomal irregularities were more in free cells. A number of globular embryoid were formed when casein hydrolysate, inositol and adenine were added in the medium after subsequent omission of auxin and coconut milk.     

Tissue lipolytic activity in calciferol intoxicated rats

Zusammenfassung Nach Calciferolzufuhr verkleinerte sich die lipolytische Aktivität der Rattenaorta, während die Aktivität des Herzgewebes unverändert blieb, wobei das Serumcholesterol anstieg. Diese Ergebnisse werden im Zusammenhang mit der Pathogenesis der Atherosklerosis diskutiert.     

Tissue survey of mammalian modulator-dependent protein kinases

Summary The levels of modulator-dependent protein kinases and protamine-dependent protein kinase(s) in various tissues of adult mice were compared. Cerebellum contained the highest levels of both modulator-dependent protein kinases and protamine-dependent protein kinase(s), whereas skeletal muscle contained no detectable enzymes. The lung and the ileum were also rich in modulator-dependent protein kinases, while other tissues were poor sources of these enzymes.Acknowledgments. This work was supported by grants (RR-08119-PK project from the National Institutes of Health, USA. and CDP-8004200 from the National Science Foundation, USA.     

Problems of insect tissue culture

Riassunto Non si è riusciti finora ad ottenere da un insetto un clone di cellule che si moltiplichi indefinitamentein vitro. D'altra parte, esistono numerosi cloni di cellule provenienti da vertebrati. Perchè questa discrepanza? Fra l'organismo degli insetti e quello dei vertebrati esistono differenze fondamentali. È chiaro, dagli studi finora pubblicati, che nel caso degli insetti non è possibile adottare direttamente i metodi di coltura da lungo tempo usati per cellule e tessuti di vertebrati. Per poter definire i fattori necessari alla nutrizione ed alla moltiplicazione cellulare è necessario, fra l'altro, che si approfondisca lo studio dell'emolinfa e che si analizzi in maggior dettaglio il metabolismo di cellule d'insettiin vitro.

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Based on a lecture presented at the course Methods and Principles of Tissue Culture, at the Medical Center of the University of Colorado in Denver, July 15, 1959. Some of the work mentioned in this paper was supported by Research Grant E 2307 from the National Institute of Allergy and Infectious Diseases, Public Health Service.     

Rhythmic neuronal activity in tissue culture

Résumé Les enregistrements électriques non-perturbants des neurones maintenus en culture, ont montré des décharges spontanées prototypes des aires du système nerveux central desquelles les groupes de cellules cultivées avaient été obtenues. Les groupes de neurones dont les enregistrements figurent ci-dessus, ont été extraits du télencéphale, mésencéphale, cervelet, et des tubercules quadrijumeaux de souris nouveau-nées. Seuls les neurones provenant du télencéphale n'ont pas produit de décharge électrique rhythmique.

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This work was supported in part by a Grant-in-Aid from Eli Lilly & Co.     

A new culture flask for cinemicrography

Resumen Se describe un frasco de cultivo especialmente adaptado para la cinemicrografia bajo microscopio de fase.

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This investigation was supported by the National Cancer Institute, USPHS Grant No. CA 06939-05.