Features of sleep in the water by the northern fur seal Callorhinus ursinus

The peculiarities of sleep in water and on land were investigated in four adult Northern fur seals (Callorhinus ursinus) of both sexes. The electrocorticogram of both hemispheres, the neck electromyogram, the electrooculogram and electrocardiogram were recorded with implanted electrodes. The interhemispheric asymmetry of EEG during slow wave sleep was observed in all the animals sleeping in water and on land. The relative amount of interhemispheric slow wave asymmetry was higher during the sleep in water comparing to that on land. The fur seals maintain their special sleep posture on the water surface by moving only one of their front flippers. The asymmetric EEG in fur seals sleeping in the water may be attributed to the asymmetric motor activity of their flippers.     

The demonstration of recurrent motor axon collaterals in the chick embryo by using horseradish peroxidase axonal transport]

Motoneurons were labelled by retrograde axonal transport of HRP applied to transected spinal nerves in 9-11-day chick embryos in the in vitro spinal cord preparation. Recurrent motor axon collaterals were revealed in 17 of 48 motor axons which could be followed in the edge regions of labelled motoneuronal pools. The results, coupled with author's earlier electrophysiological data, provide further evidence for the presence of the Renshaw inhibition in the avian spinal cord.     

Acid phosphatase activity and the state of lysosomal membranes in a primary culture of cardiomyocytes of newborn rats during hypoxia

Acid phosphatase activity, ATP and cyclic nucleotide levels were studied in primary cardiomyocyte cultures of newborn rats under hypoxic conditions. It was shown that incubation of cardiac cells in Eagle's medium supplemented with 10% calf serum during hypoxia (5% O2, 5% CO2, 90% N2) caused an hour later a decrease in lysosomal acid phosphatase activity, whereas free enzyme activity increased. The exposure of cells in Hanks salt solution to one hour hypoxia resulted in a 3-fold decrease of ATP level and further increase in free acid phosphatase activity. It was found that cAMP and cGMP levels do not depend on the presence of hypoxia. The mechanisms involved in the regulation of lysosomal membrane state are discussed.     

The effect of cytostatics and corticosteroids on the phagocytic and fungicidal activity of the neutrophilic granulocytes

In vitro tests have revealed that cytostatic agents and corticosteroids, introduced in vivo, produce an inhibitory effect on the phagocytic activity of mouse neutrophil granulocytes and on their capacity for the destruction of Candida albicans blastospores. The action of the above-mentioned preparations may be an important pathogenetic factor which when introduced into the animals, contributes to the development of candidiasis.     

NAG infection in Rana temporaria with suppressed normal intestinal microflora]

Frogs of the Rana temporaria species with disturbed biocenosis induced by combined effects of hypothermia (+4 degrees C) and tetracycline were used as an experimental model. The animals were inoculated orally with cultured NAD-vibrios and subjected to clinical, bacteriological, immunomorphological and electron microscopical examinations. The lymph-blood system was shown to be a possible pathway for generalization of the infection. Several causes of long-term persistence of the vibrios in Rana temporaria are discussed.     

Features of ultrastructural changes of tumor cells in tissue culture under the effect of energy metabolism inhibitors

It is shown that 2,4-dinitrophenol and dicyclohexylcarbodiimide, energy metabolism inhibitors, induce regular specific changes of the HeLa culture cells ultrastructure. Peculiarities of metabolism of the tumor cells as against the normal culture cells cause weaker and slower response.     

Identification of various hydrophobic zones in microsomal membranes containing cytochrome P-450 binding sites for type I and II substrates

Two different phospholipid hydrophobic zones in the membrane associated with cytochrome P-450 were identified. One of them exhibits selective sensitivity towards the protonated influence of carbonylcyanide-m-chlorophenyl hydrazone and possesses binding sites for type I substrates. The second one includes the heme group of cytochrome P-450 and herein the binding sites for type II substrates. Sodium deoxycholate (0.75-2.0 mM) disrupts both zones. Subsequent incorporation of fluorine atoms into a type II substrate (aniline) results in the increase in the hydrophobicity of aniline halogenated derivatives and in changes in the substrate-binding sites for tetra- and pentafluoroanilines from the heme-iron sphere to the apoenzyme of cytochrome P-450.