Degradation of 14C, 3H, and 36Cl-labelled gamma-hexachlorocyclohexane by anaerobic soil microorganisms (author's transl)]

Up to 90% of the gamma-Hexachlorocyclohexane (gamma-HCH) applied to an anaerobic mixed bacterial flora enriched from an arable soil were degraded within 4-5 days. Degradation resulted in a rapid release of chloride and in formation of chlorine-free volatile metabolites. CO2 formation from the molecule was not detected. Investigations with 14C/3H- and 36Cl/3H double-labelled gamma-HCH indicated that the release of Cl and H did not occur in the ratio of 1:1. More Cl than H was split off. The volatile compounds contained more 14C than 3H. Gas chromatographic studies also showed the rapid decrease of gamma-HCH and the formation of several metabolities. gamma-Pentachlorocyclohexene was nto detected. Increasing O2-contents in the gas phase of cultures resulted in decreases of the compound's degradation. Release of chloride and of volatile metabolites were observed with O2 contents in the gas phase up to 5%. alpha-HCH was also, but more slowly as with gamma-HCH, degraded by the anaerobic mixed flora. Chloride was released and volatile, chlorine-free metabolites were found.     

Distribution of Pseudomonas aeruginosa in experimentally infected mice (author's transl)]

The distribution of experimentally administered Pseudomonas aeruginosa was studied in germfree CF no. 1 mice, barrier-sustained DDD mice with or without oral treatment of aminobenzyl-penicillin and conventional DDD mice. On day 1 after oral administration of 8 X 10(7) organisms, more than 10(8) of organisms/g were recovered from the feces of ex-germfree mice and the number was maintained during the experiment. On the other hand, from barrier-sustained mice with antibiotic treatment and those without the treatment, 10(4-7) and 10(3) organisms were recovered, respectively. In all of monoassociated mice and some antibiotic-treated barrier-sustained ones the organisms were recovered also from the lungs, liver, spleen and kidneys. In conventional mice, however, no organisms were recovered from the internal organs throughout the experiment, while some were detectable from the intestinal tracts. The distribution of the organisms in naturally infected mice appears to be similar to that of experimentally infected animals with antibiotics.     

Reproductive cycle of trout and tench: effect of experimental variations of the temperature (author's transl)]

10 In the rainbow trout and the tench, at the time of spermatogonia divisions a rise in the plasma gonadotropin levels was observed. Just before or during the spawning period, E217 beta and plasma gonadotropin reach their maximum levels. 20 When the effects of raising the natural cycle temperature of the tench were studied (deltat + 3 degrees C and + 6 degrees C), in conditions where nycthemeral and seasonal rythmicity were maintained, a significant increase in fertility was observed with the increase in temperature (the first spawning period was earlier and there was a rise in the number of spawnings). This effect of temperature seems to act at the level of the hypothalamo-pituitary system.     

Effect of methionine sulfone on the growth of Citrobacter intermedius C3 (author's transl)]

Specific activity of glutamate dehydrogenase (GD) and glutamate synthase (GtS) has been determined in the wild strain C3 and on a non excreting pro- mutant strain. Methionine sulfone shows inhibitory effects on their growth. The addition of alpha-ketoglutarate to the medium prevents the inhibitory effect and increases the GtS specific activity in both strains. The physiological effect of methionine sulfone and its suppression by alpha-ketoglutarate is discussed.     

Conditions for greater survival of neonatally thymectomized Swiss mice (author's transl)]

A total of 385 albino Swiss mice, of both sexes, between 24 and 30 hours of age are neonatally thymectomized, by means of a suction pump method. One batch is operated under ether anesthesia, another with sodium pentobarbital, and a third one with Cryoanesthesia. The last batch is subdivided into 2. In one of these the mother is anesthetized with sodium pentobarbital intraperitoneally, during the postoperative recovery of the litter, and in the other the mother is left without treatment. The mothers of the first two batches of thymectomized animals are anesthetized with the same products as their offspring. The percentage of survival of thymectomized breeding mice in greatest in the batch operated under Cryoanesthesia and whose mothers received the above mentioned treatment. Statistically the differences are very significant and they might be accounted to the fact that the mothers are anesthetized while their offspring normalize their physiological constants with better recovery in feeding, hydration, shelter and rest.     

Investigation of the fibroblast chalone (author's transl)]

By ultrafiltration of a cytoplasm preparation from diploid human fibroblasts (Flow 2000) we obtained a fraction which inhibited the proliferation of the same cells. We succeeded in demonstrating fibroblast chalone, because the activity was endogenous, reversible and affected murine fibroblasts, but not human cervical carcinoma cells (HeLa S3) or neuronal tumor cells of rats (B104). The chalone activity was found in the range of molecular weights between 10 000 and 100 000. The active part was of peptide nature, for proteolytic treatment destroyed the chalone activity.     

Electroencephalographic study of the eel (author's transl)]

1 This paper describes a method for electroencephalographic recording from unanesthetized and unraistrained european eels (Anguilla anguilla L.). 2 EEG's records from the cerebellum, tectum opticum, telencephalon and olfactory bulb of the eel are compared with other fish previously studied by other authors. 3 Averaged evoked visual potentials from the telencephalon, tectum opticum and cerebellum are presented. 4 This study provides a reference point for future research on fish vigilance depth and EEG changes associated with modified environmental factors.