Chromosome counts forErysimum durum,Erysimum hieraciifolium andChenopodium album

The following chromosome numbers are reported:Erysimum durum J. etC. Presl: 2n=48;Erysimum hieraciifolium L.: 2n=32;Chenopodium album L. from three localities in Brno: 2n=54.     

Ionic base radicals in gamma-irradiated oriented non-deuterated and fully deuterated DNA.

The free radicals induced by gamma-irradiation at 77 K in non-deuterated and fully deuterated oriented samples of moist algal DNA have been studied by electron paramagnetic resonance (e.p.r.). The e.p.r. spectra from the non-deuterated sample were found to be similar to those from calf-thymus DNA studied previously. Numerical spectra simulations were performed based on the previously proposed interpretation of the DNA spectra at 77 K in terms of a mixture of two spectral components arising from anionic and cationic base radicals (probably on thymine and guanine, respectively). The simulations were found to account satisfactorily for the main characteristics of the e.p.r. spectra from both the non-deuterated and the fully deuterated algal DNA sample.     

Action of plasmin on oxidized bovine growth hormone

Fragmentation of performic acid-oxidized bovine pituitary growth hormone with plasmin has been investigated. It was found that not all tryptic-sensitive bonds were cleaved by plasmin, and that most of the peptide fragments from plasmin digest were derived from the carboxyl terminal portion of the bovine growth hormone molecule.     

Mutagenitätsprüfung bestrahlter Lebensmittel mit dem “dominant lethal test”

Zusammenfassung An insgesamt 716 Ratten und 750 Mäusen wurde eine mögliche mutagene Wirkung einer bestrahlten Nahrung geprüft. Fertilität, Tragezeitdauer, Wurfgröße, Aufzuchtleistung und Geschlechtsverhältnis zeigten in 5 aufeinanderfolgenden Rattengenerationen keine Störungen in der Reproduktionsfähigkeit an. Es konnte kein Anstieg der Mißbildungsrate bei den Rattenfeten beobachtet werden. Auch die Fruchtbarkeit der männlichen und der weiblichen Tiere der Mäusegeneration war ungestört. Durch den dominant lethal test an Ratten und Mäusen konnte keine embryotoxische oder mutagene Wirkung der bestrahlten Nahrung festgestellt werden, die sich in mit den verwendeten statistischen Methoden erfaßbaren Unterschieden bei den fünf untersuchten Variablen ausdrückt. Der nachgewiesene hohe Gehalt an freien Radikalen in dem bestrahlten Futter stellte nach den vorliegenden Ergebnissen keinen Faktor dar, der schädliche Wirkungen in den untersuchten Parametern bei den Versuchstieren zur Folge hatte.

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Mutagenicity testing of irradiated foodstuffs using the dominant lethal test

Summary The possible mutagenic effect of an irradiated diet was studied using 716 rats (5 generations) and 750 mice (1 generation). The diet consisted of 35% whole milk powder, irradiated with a dose of 4.5 Mrad, and 65% of standard rat diet. In the experiment with mice, an additional group received the same diet, but all of it was irradiated. In the rat tests the consumption of the irradiated diet did not cause any differences in fertility, duration of pregnancy, litter size, weaning index, sex ratio or number of fetal malformations. The fertility of male and female mice was also found to be unaffected. Data from 5 variables of the dominant lethal test on rats and mice were subjected to statistical evaluation and no embryotoxic or mutagenic effects were found. The high content of free radicals in the irradiated food did not give rise to harmful effects in any of the parameters studied.

     

Plasma levels of the methyl ester of 15-methyl PGF2α in connection with intravenous and vaginal administration to the human

After intravenous injection of the methyl ester of 15-methyl-PGF_2α the drug initially disappeared faster than the corresponding free acid, but still after one hour, about 1% of the active drug is circulating in plasma. Vaginal administration of single suppositories containing 1 mg of 15-methyl-PGF_2α methyl ester and determination of plasma levels using gas chromatography - mass spectrometry demonstrated that the highest plasma levels were reached after 1.5 - 3 hours.Vaginal suppositories were administered according to different dose schedules for induction of abortion and plasma levels of 15-methyl-PGF_2α and it's ester were determined. There seemed to be a gross correlation between given doses and obtained plasma level. The data will serve as basis for further development of vaginal delivery devices.     

Field experiment on the ability of earthworms (Lumbricidae) to reduce the transmission of infective larvae of Cooperia oncophora (Trichostrongylidae) from cow pats to grass

In Denmark earthworms play an important role in the disappearance of cow pats on pastures. Field investigations were designed to study the influence of earthworms on the transmission of infective Cooperia oncophora larvae from experimental cow pats to grass. Results from the present experiment showed that cow pats, protected from attack by earthworms, disappeared at a much lower rate than unprotected cow pats. Development in faeces and transmission to grass of C. oncophora larvae were disturbed by the disintegration of cow pats. The rapid disintegration of unprotected cow pats resulted in an approximately 50% reduction of infective C. oncophora larvae on grass in the vicinity of these cow pats, as compared with larval contamination of grass around protected cow pats. How earthworms may cause a reduction in the transmission of infective C. oncophora larvae to grass by creating adverse conditions for the survival of parasite larvae in the cow pats, by eating and killing the parasite larvae, and by depositing parasite larvae in the soil is discussed.     

Field experiments on the ability of Arthrobotrys oligospora (Hyphomycetales) to reduce the number of larvae of Cooperia oncophora (Trichostrongylidae) in cow pats and surrounding grass

In field experiments, conducted on parasite-free grass plots in two consecutive summers, artificially prepared cow pats containing Cooperia oncophora eggs were inoculated with the nematode-trapping fungus Arthrobotrys oligospora. Numbers of infective C. oncophora larvae isolated from the pats as well as from the surrounding herbage were subject to an approximately ten-fold reduction as compared with numbers in fungus-free pats and herbage surrounding these. This reduction was undoubtedly a result of entrapment of the parasite larvae within the faecal pats.