Effect of enkephalins in the presence of the antibiotic bacitracin in the longitudinal muscle strip preparation from guinea-pig ileum

Summary The antibiotic bacitracin (5×10^–5–4×10^–4 M) increases the inhibition of the contractile response caused by both enkephalin release and direct application of Met-enkephalin 5×10^–7 M in the longitudinal muscle strip preparation from guinea-pig ileum. This effect is attributed to an inhibition of enkephalin degrading peptidases by bacitracin.     

Investigations on the effects of chronically administered small amounts of DDT in mice

Zusammenfassung BALB-c Mäusen wurde während 5 Generationen DDT (0,3–0,6 mg/kg Körpergewicht) verabreicht. Bei 61 Tieren (8,92%) traten maligne Veränderungen ein (Leukemien, Tumoren), während in der Kontrollgruppe nur 5 Tiere (1,22%) erkrankten.     

Thermoregulatory heat production by periaortic brown adipose tissue in the non-cold-acclima. tized rat

Zusammenfassung Mit Thermoelementen im Aortenbogen und 35 mm distal davon gemessener Temperatur zeigt sich in thermoneutraler Umgebung entweder keine oder nur eine geringere Temperaturerhöhung des distalen Punktes. In kalter Umgebung hingegen ist die Differenz signifikant vergrössert.     

Lag period of action of 25-hydroxycholecalciferol on bone collagen metabolism in vitamin D deficient rats

Zusammenfassung Nachweis, dass die Freisetzung von Hydroxyprolin bei Knochenfragmenten bereits 6 h nach i.v. Verabreichung von 2,5 g 25-Hydroxycalciferol signifikant erhöht war, während eine entsprechend zugeführte Dosis von Vitamin D₃ erst 13 h später deutlich wirkte.

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We thank Dr.E. Kodicek and Dr.E. M. Cruickshank of Dunn Nutritional Laboratory for help and criticism, and Mrs.J. Jobbágy for technical assistance.     

Brain stem projections to the cerebral cortex in the rat.

By means of the HRP method it was shown that the entire cerebral cortex, but in greater proportion the frontal and posterior temporo-parietal regions, receive fibres from the dorsal and medial raphe nuclei and from the locus coeruleus. In contrast, the pars compacta substantiae nigrae and the tegmental area send projections to the motor and cingular areas respectively.     

Stimulation of the growth of murine bone marrow colonies in vitro by an acute inflammatory exudate. Comparison with colony stimulating factor CSF)]

Formation of colonies from mice bone marrow progenitors of macrophages and granulocytes in methylcellulose culture was induced by an inflammatory pleural exudate obtained from mice injected with dextran. Mitogenic activity of this acute inflammatory exudate was compared with that of colony stimulating factor (CSF). It was found that colony and cluster counts, during 10 days of culture, were similar with the two types of stimulating factors. When used at the same dose, exudate was less active than CSF. It was concluded that inflammatory exudate showed an activity similar to that of CSF but contained a smaller amount of stimulating factor. Further cytochemical studies are necessary to specify whether or not the two factors induced the same type of colonies (monocytic or granulocytic).     

Oncostatic activity of extracts from Alangium vitiense on murine lymphoid neoplasms]

A total alkaloid and two purified alkaloid extracts of Alangium Vitiense were revealed by our experimental screening to be oncostatic on L1210 leukemia and two other lymphoid neoplasias in Mice. They are not active on myelomonocytoid leukemia WEHI3 nor on B16 melanoma.     

Effects of bilateral lesions of the nuclei habenulae on plasma thyroxine levels in Japanese quail

Summary Electrolytic bilateral lesions of the nuclei habenulae were made in male, adult photostimulated quail. Habenular destruction led to a marked decrease in the plasma thyroxine level (40%), whereas sham operated birds did not differ from controls. This result appears to be somewhat different from those obtained in mammals and the mechanisms of habenular-thyroid interrelationships are unknown.     

Light and electron microscopic evidence of hypothalamic afferences originating from the hippocampus in the pigeon

Summary Degenerating nervous fibres and synaptic boutons were demonstrated in the nuclei posterior medialis hypothalami after hippocampal lesions in the pigeon (light and electron microscopy).Acknowledgments. The authors are indebted to Mr.Louis Dongan for histological assistance. Parts of this experiment were supported by a grant from the C. N. R. S. (ERA No. 85).