Leydig cell andΔ 5-3β-hydroxysteroid dehydrogenase activity in the testis of toad (Bufo melanostictus) following cold exposuredehydrogenase activity in the testis of toad (Bufo melanostictus) following cold exposure

Summary Leydig cell nuclear area and ⁵-3-hydroxysteroid dehydrogenase activity were increased in the testis ofBufo melanostictus 2 days after a single short-term cold exposure. Both parameters returned to normal values 4 days later.     

Identification of an acyclic diterpene alcohol in the defense secretion of soldiers ofReticulitermes lucifugus

Summary The defense secretion of soldiers ofReticulitermes lucifugus has been shown to contain, predominantly, (R)-(–)-(E,E)-geranyllinalool together with germacrene A and -farnesene.This report covers part of a collaborative study with J.-L. Clément, Lab. d'Evolution, Université P. et M. Curie, Paris, to whom we are grateful for supplies of material and discussions. We also thank Dr O.T. Jones for collections ofReticulitermes lucifugus.     

Genetic polymorphisms and intrauterine development. Evidence of decreased heterozygosity in light-for-dates human newborn babies

Summary In 2 independent samples of low-birth-weight infants the proportion of females and homozygotes for a series of polymorphic systems was higher in light-for-dates than in preterm babies. The observation seems to give support to the hypothesis that homozygosity for normal polymorphisms may decrease in general intrauterine growth rate. Since it is known that survival rate is strongly related to birth weight, a correlation between growth retardation and homozygosity may have a major role in the maintenance of such polimorphisms.We thank Prof. L. Ginzburg for helpful comments.     

Production and detection of antibody against estradiol receptor in the calf uterus. Interaction with the estrogen receptor from the hen oviduct]

The antibodies against estrogen receptor were obtained after injecting Rabbits with a cytoplasmic receptor fraction isolated from Calf uterus. The estrogen receptor was partially proteolysed by the action of trypsin and subsequently purified by affinity chromatography (purification 4,000 to 10,000 fold, to a purity of 5-20%). The affinity of the antibody for the proteolysed receptor is KD approximately 1 nM and serum titres have reached values of approximately 50 nM. The values remained constant after the third injection. Preliminary results indicate that the antibody has approximately the same affinity for "native" cytoplasmic estrogen receptor from Calf uterus, as well as for the "trypsinized" forms of estrogen receptor isolated from Calf uterine cytosol and Hen oviduct nuclei.     

Comparative study, in the Allium test, of the cytotoxicity of tubulosine and of 6 synthetized pseudo-tubulosines]

Comparing cytotoxicity of tubulosine and of six newly synthesized pseudo-tubulosines in the Allium test, we have characterized all the current features of protein inhibition. Nevertheless cytotoxicity of the six pseudotubulosines is much weaker. Furthermore, "floating poles anaphasis", a disturbance characteristic of the action of tubulosine, has been found with a lesser intensity with the other compounds.     

Mechanical responses of the isolated cervix of the day-22 pregnant rat to field stimulation.

Field stimulation of isolated, spirally-cut cervix from day-22 pregnant rats produced contractions which could be inhibited by tetrodotoxin or hyoscine and potentiated by propranolol. The rat cervix would appear to receive both cholinergic and noradrenergic innervations whose transmitters activate muscarinic cholinoceptors and beta-adrenoceptors respectively.     

PPD-induced blastogenesis is auto-regulated by suppressor cells generated in vitro.

Suppressor cell induction can be demonstrated during antigen specific blastogenesis by using the same methods which have shown induction of suppressor cells by Con A. Since suppressor cells are rapidly generated during antigen specific blastogenesis, they must regulate the final level of blastogenesis induced during the seven day in vitro incubation.     

The detection of superoxide anion from the reaction of oxyhemoglobin and phenylhydrazine using EPR spectroscopy

Summary The low temperature EPR spectrum of a quickly reacted mixture of oxyhemoglobin and phenylhydrazine was studied. With the use of a computer, the spectral contribution of methemoglobin in the region of g=2 was subtracted. The remaining spectrum was that of an axial free radical (g=2.00, g=2.06) having the magnetic parameters of superoxide anion. In the presence of superoxide dismutase, this axial radical was not seen, confirming that superoxide anion is indeed generated by the reaction.The portion of this investigation carried out at the Albert Einstein College of Medicine was supported in part by US Public Health Service Research Grant HL-93399 from the Heart and Lung Institute and by National Institute Contract Nol-CP-55606 to J.P. This is communication No. 378 from the Joan and Lester Avnet Institute of Molecular Biology.Predoctoral fellow in the Medical Scientist Training Program (United States Public Health Service Grant 5-TO-5-GM 01669-12) at the New York University School of Medicine.Recipient of a grant-in-aid from the New York Heart Association.     

Light transmission. I. An acoustic method able to monitor transmitted light

Summary A method able to monitor transmitted light acoustically is described. It makes use of an amplifier of light variations, provided with a photocell and a sound device, a photometer, an optic probe and a special support.Acknowledgments. The author would like to thank Dr Leonard Salzarulo, chairman of the Physics Department of the New Jersey Institute of Technology, for the critical reading of the paper. The author acknowledges the invaluable assistance of Prof. Araldo Ramundo of the Centro Regionale Professionale in Cosenza, Italy, for designing and assembling the electronic amplifier. Appreciation is also extended to Prof. Giuseppe Battendieri of the Liceo Scientifico Enrico Fermi in Cosenza, Italy, for the schematic reproduction of the apparatus.     

A simple theoretical criterion of chemical carcinogenicity?

Summary The simple theoretical criterion for chemical carcinogenicity based on the average quasi-valence number is discussed and shown to be inappropriate as a reliable indicator of carcinogenicity of any organic compound.I thank very much Dr R. Gordon for reading the English text and also for a stimulating discussion.