Histochemical study of isolated neurons in culture from chick embryo spinal ganglia

Summary Dissociated chick embryo spinal ganglia neurons, cultivated without direct contact with glial cells maintain some enzymatic activities, for example: carboxylic esterases, succinic-dehydrogenase (SDH), glutamic-dehydrogenase (GDH), monoamine oxidase (MAO), lactico-dehydrogenase (LDH) and alcoholic-dehydrogenase (ADH) for several days periods.Nerve growth factor (NGF) prolongs the maintenance of the mitochondrial enzymes, carboxylic esterases, LDH and ADH in cultures of isolated neurons. Extract of embryonic spinal cord gives almost similar results as NGF.With the technical assistance of Miss E. Darcel.This work is part of the Doctorat ès-Sciences thesis.     

The classification of free-living spirochetes

Summary The natural relationships among free-living and host-associated spirochetes were studied by investigating aspects of their morphology, physiology and DNA base composition. These studies indicated that the strictly and facultatively anaerobic, free-living spirochetes share characteristics which distinguish them from their host-associated counterparts and from the free-living leptospires.It is suggested that the strictly and facultatively anaerobic, free-living spirochetes be grouped in the genus Spirochaeta and that this genus include the following four species: S. plicatilis (type species), S. stenostrepta, S. zwelzerae (Treponema zuelzerae), and S. aurantia. The characteristics of these species are described.     

DNA base composition of Microcyclus species and organisms of similar morphology

Summary From studies of the DNA base composition of Microcyclus species, it is concluded that the genus is to be regarded as a taxonomically heterogeneous group. This agrees with morphological observations of the different species.     

DISTRIBUTION QUANTITATIVE DES DIVERS PHOSPHO-LIPIDES DANS LES NEURONES ET LES CELLULES GLIALES ISOLES DU CORTEX CEREBRAL DE RAT ADULTE

Resumé–— On décrit une méhode de préparation de neurones et de cellules gliales à partir du cortex cérébral, basée sur la dissociation du tissu à travers un tamis en nylon suivie ď une ultracentrifugation différentielle sur gradients de sucrose et de Ficoll.
On a dosé le DNA, ľazote protéque et les divers phospholipides. II ressort que le taux ď DNA par cellule est identique dans les neurones et les cellules gliales. Par contre, la quantité absolue ďazote protéique est 2.8 fois plus élevée dans les cellules gliales, celle des lipides totaux et des divers phospholipides 5-6 fois plus élevée.
La proportion de chacun des phospholipides dérminée par rapport aux phospholipides totaux est similaire dans les deux types cellulaires.     

The DNA base composition of a flagellar mutant ofComamonas terrigena ATCC 8461

The lophotrichous flagellatedComamonas terrigena, ATCC 8461, spontaneously produces a peritrichous flagellate mutant which is physiologically like the parent. The DNA base composition of the parent and mutant were the same with 64% GC.