Effect of some chemicals on the hemagglutination activities and infectivity to chick embryos of different strains of Newcastle disease and fowl-plague viruses

Summary Ascorbic acid reduced the agglutination activities of the various strains of Newcastle disease and fowl-plague viruses used but was in-effective with respects to their infectivity powers.     

pH-stability patterns of some strains of Newcastle disease and fowl-plague viruses

Summary The strains of fowl-plague virus being tested completely lost their infectivity to chick embryos when stored at p_H 4 for one hour or more while those of the virus of Newcastle disease were all infective to chick embryos when stored at this p_H-value for periods up to 7 days.     

Response of some strains of Newcastle disease and fowl-plague viruses to two quinones

Summary Comparative studies of the response of some Egyptian strains of Newcastle disease and fowl-plague viruses to tolu- and thymoquinones revealed that the two quinones appreciably reduced the infectivity, but not the hemagglutinative powers of the virus strains, toluquinone being more effective in this respect than thymoquinone. The different viruses or virus strains responded differently to the two quinones.     

Effect of different strains of newcastle disease and fowl-plague viruses on a group of sulphonphthalein dyes

Summary Strains of fowl-plague or Newcastle disease viruses may be easily separated by examining the rate of discharge of certain dyes of the sulphonphthalein group when inoculated with each virus strain into the allantoic fluid of chick embryos.     

Effect of anionic surfactants on some dehydrogenases and phosphofructokinase activities in loach embryos

Glucose-6-phosphatedehydrogenase (EC 1.1.1.49), lactatedehydrogenase (EC 1.1.1.27), malate dehydrogenase (EC 1.1.1.38) and phosphofructokinase (EC 2.7.1.11) activities in loach (Misgurnus fossilis L.) embryos were determined after incubation of the latter in the media containing surfactants--alkyl benzol sulphonates NP-1, NP-3, RAS and secondary alkyl sulphate "Progress". The determined activities changed under the influence of the used surfactants. Minimal changes of the activities were observed in the media with sulphonol np-1, and maximal ones--with the "Progress" preparation. The dependence is revealed of the enzyme activities changes upon the surfactant concentration and the stage of the embryo development.     

The effect of inhibition of protein synthesis on some biochemical and functional activities of the brain in chick embryos]

By means of radioautographic and biochemical methods, it has been shown that cycloheximide administration to the brain in a dose of 76 mug significantly decreases protein synthesis within 30 min, the decrease being maximal after 2 hours. RNA synthesis in neuronal cytoplasm is blocked within 4 hours. Changes in biopotentials of the forebrain and midbrain structures were observed already 15-20 minutes after cycloheximide treatment. Application of cycloheximide (12.5-25 mug) to the area of vascular brannching of the foetal membranes of a 17-day embryo inhibits motor activity within 20 min.; in 28-day embryos, this effect is observed at a dose of 75 mug. Therefore, inhibition of protein synthesis in the brain results in sharp changes of the electrical activity of the brain and inhibits motor activity of the chick embryo.     

Mutagenicity of 30 chemicals in Salmonella typhimurium strains possessing different nitroreductase or O-acetyltransferase activities

Salmonella typhimurium YG1021, YG1024, YG1026 and YG1029 are new derivatives of the Ames tester strains TA98 and TA100, with elevated 'classical' nitroreductase or acetyl-CoA:N-hydroxyarylamine O-acetyltransferase level. Thirty mutagens with different structures were tested using these strains and the sensitivities were compared with those of the conventional strains and of the enzyme-deficient strains. Elevated O-acetyltransferase activity of the indicator strains specifically increased their ability to detect the mutagenicity of aromatic nitro, amino and hydroxylamino compounds, whereas the strains with high nitroreductase activity were very sensitive to some nitroaromatics. The combined use of the isogenic tester strains with different metabolic capacities was quite useful to assess the intracellular metabolic activation and detoxification mechanisms of chemical mutagens.     

Application and effects of some fat-soluble hormones on the development of chick embryos

Summary An attempt has been made to employ fat-soluble anabolic steroids (testosterone propionate and ethylestrenol) in the manner of water soluble compounds. The substances are injected into the egg proper (i.e., the yolk ball) as close to the embryo as possible. The effects are assessed from the points of view of mortality, malformation and increase in dry and fresh weights. The mortality pattern varies with the substance injected. No malformations were detected. Both testosterone propionate and ethylestrenol cause increase in dry weights at particular doses. Sesame oil which is used as carrier of these substances is itself responsible for some mortality. The experiments also suggest that in lower dosages ethylestrenol somehow counteracts the lethal effect of sesame oil.