The effects of time of equilibration with cryoprotectants at 0°C prior to freezing on the survival of mouse embryos frozen by the two-step method

Summary Mouse embryos were frozen by the two-step method after equilibration for 0.1–60 min with cryoprotectants at 0°C. No survival or a very low survival was obtained after equilibration for only 0.1 min. The morulae showed the highest survival rates when equilibration time was 5–30 min with 2 M DMSO, 20–30 min with 2 M glycerol, 5–10 min with 2 M ethylene glycol and 20–30 min with 2 M propylene glycol, respectively.     

The effects of actinomycin D and chloramphenicol on the rat preimplantation embryos

Summary Actinomycin D and chloramphenicol, injected in the rat on day 3 or 4 of gestation, induce embryolethality and embryotoxicity. These effects are revealed on day 5 of pregnancy by reduced number of blastocysts and by decrease of mean blastomeres number.     

The effects of actinomycin D and chloramphenicol on the rat preimplantation embryos

Actinomycin D and chloramphenicol, injected in the rat on day 3 or 4 of gestation, induce embryolethality and embryotoxicity. These effects are revealed on day 5 of pregnancy by reduced number of blastocysts and by decrease of mean blastomeres number.     

Morphogenetic effects of follicle stimulating hormone: Effects on the synthesis of nuclear RNA's by chick embryos

Résumé L'hormone de maturation folliculaire (FSH), qui possède des propriétés morphogénétiques nettes, produit des effets différentiels sur la synthèse des ARN nucléaires chez des embryons de poule dans les différentes étapes de leur développement. Les expériences indiquent que lors du traitement par l'hormone, celle-ci peut stimuler la synthèse de différentes classes d'ARN, selon l'étape du développement.     

Increase in the survival time of mice exposed to ionizing radiation by a new class of free radical scavengers

Summary N-acyl dehydroalanines react with and scavenge mainly superoxide radical and hydroxyl radical (HO^.). The ortho-methoxyphenylacetyl dehydroalanine derivative, indexed as AD-20, protects mice against damage resulting from total body X-irradiation, as measured by the increase in their survival time. AD-20 increases the LD₅₀ at 30 days from 6.1 to 7.3 Gy in animals exposed to a wide range of X-rays (6 to 10 Gy). The dose reduction factor (D R F) of AD-20 is 1.20. We postulate that such radioprotective effect may result from its free radical scavenging activity.     

Increase in the survival time of mice exposed to ionizing radiation by a new class of free radical scavengers

N-acyl dehydroalanines react with and scavenge mainly superoxide radical (O-2.) and hydroxyl radical (HO.). The ortho-methoxyphenylacetyl dehydroalanine derivative, indexed as AD-20, protects mice against damage resulting from total body X-irradiation, as measured by the increase in their survival time. AD-20 increases the LD50 at 30 days from 6.1 to 7.3 Gy in animals exposed to a wide range of X-rays (6 to 10 Gy). The dose reduction factor (D R F) of AD-20 is 1.20. We postulate that such radioprotective effect may result from its free radical scavenging activity.     

Depressant effects of major tranquillizers on contact hypersensitivity to picryl chloride in the mouse

Summary Chlorpromazine, levomepromazine, thioproperazine, promethazine and haloperidol were found to significantly depress contact hypersensitivity to picryl chloride in the mouse, a model of cell-mediated immune response.The skilled technical assistance of R. Tedone is warmly acknowledged.     

The effect of insulin on the formation of glycogen by the mouse diaphragm in vitro

Zusammenfassung Insulinzugabe in ein Milieu mit (U¹⁴C) Glukose stimuliert gleichfalls die Bildung des radio-wie des nicht-radioaktiven Glykogens in vitro. Insulin vermehrt ebenso die Bildung von Glykogen durch das Mäusezwerchfell bei Abwesenheit von Glukose im Inkubationsmilieu. Es wird eine doppelte Glykogen-bildung angenommen: 1. Inkorporation von exogener Glukose in Glykogen; 2. Inkorporation eines endogenen Vorläufers im Glykogen, der mit Glukose nicht identisch ist.

---

---

This research was supported by the Swiss National Fund for Scientific Research (Grant No. 3279).     

The effects in vivo of some sex hormones on the growth of tibias of normal and chondrodystrophic (Creeper) chick embryos]

Various sex hormones (testosterone, oestradiol, dehydroepiandrosterone), in the form of suspensions in oil, are injected into the allantois of normal and chondrodystrophic (Creeper) chick embryos of 6 days 1/2 incubation. Observations made on each of the phenotypes on the 12th day of incubation show that oil injected alone causes a significant decrease in the dry weight of the tibiae. This inhibitory effect is partially abolished when the oil is injected together with the sex hormones, testosterone being the most effective.     

The effect of thyroid function on the prothrombin time response to warfarin in rats

Zusammenfassung Die Wirkung von Warfarin, einem Anticoagulans der Dicumarolgruppe, ist erhöht bei hyperthyroiden und vermindert bei hypothyroiden Ratten.

---

---

This work was supported by a grant from the National Research Council of Canada.     

The effects of intraperitoneal adaptation to histamine on the anaphylactic shock in the guinea-pig

Résumé Les cobayes adaptés à l'histamine par voie intrapéritonéale sont protégés contre le choc anaphylactique. Les mécanismes périphériques de la résistance sont discutés.     

The effects of follicle-stimulating hormone on the uptake of labelled glycine by the chick embryo

Résumé On a étudié par autoradiographie l'incorporation de la glycine-1-C¹⁴ par l'embryon du poussin. L'incorporation était la plus élevée dans le tissu neural et puis dans le notochorde et les somites. Après traitement avec le FSH, une incorporation plus grande s'est produite dans les mésodermes chordal et somitique. On propose qu'il peut s'agir d'un effet morphogénétique. Il est particulièrement significatif que le mésoderme axial, qui joue un rôle si important dans l'induction du système nerveux, paraît être également le point d'action de l'hormone.

---

---

Supported by Grant No. DRG-913 from the Damon Runyon Memorial Fund for Cancer Research and also by grants from the Medical Research Council, British Empire Cancer Campaign for Research and the U.S. Public Health Service to the Chester Beatty Research Institute (Institute of Cancer Research: Royal Cancer Hospital). The authors also wish to thank the National Institutes of Health, USA for the FSH preparations.