Effects of retinoic acid on embryonic development of mice in culture

Summary The effects of all-trans-retinoic acid (RA) (tretinoin) on the craniofacial development of mouse embryos were examined using whole embryo culture. In day 8 embryos cultured for 48 h, embryonic growth was inhibited concentration-dependently by all-trans-RA treatment. Most of the treated embryos exhibited hypoplasia of the primary palatal processes and a reduction in the development of the first viscreral arches. In day 10 embryos cultured for 48 h, although embryonic growth was not inhibited at any concentrations of all-trans-RA, median cleft lip (93%), hypoplasia of the primary palatal processes (37%) and limb reduction deformities (48%) occurred commonly. Furthermore, RA treatment greatly reduced the size of the secondary palatal processes. The incorporation of³H-thymidine in the treated maxillary processes was decreased to 65% of the control value at 1.0×10^–7 M alltrans-RA. These findings indicate that all-trans-RA is teratogenic in mouse whole embryo culture.     

Effectiveness of phosphocitrate and N-sulpho-2-amino tricarballylate,a new analogue of phosphocitrate,in blocking hydroxyapatite induced crystal growth and calcium accumulation by matrix vesicles

Summary Phosphocitrate and its analogue N-sulpho-2-amino tricarballylate were compared with ethane-1-hydroxy-1, 1-diphosphonate for inhibition of calcium phosphate crystallization in hydroxyapatite induced crystal growth and⁴⁵Ca uptake by matrix vesicles. Phosphocitrate (1 M) was the most potent inhibitor followed by ethane-1-hydroxy-1, 1-diphosphonate and N-sulpho-2-amino tricarballylate, the latter requiring a high concentration (100 M) to be equally effective as an inhibitor.Acknowledgments. We wish to thank Mr J. Jordan and Miss L.C. Ward for the excellent technical assistance and Mr R.J. Tennant for the transmission electron microscopy. We also thank the Golden Poultry Farming Industries Ltd., Hobart, Tasmania for their generous supply of broiler strain chickens.     

Imprinting of the Peking duck (anas platyrhynchos) and dependence on exposure to light during ontogenesis

Summary Embryos of Peking ducks were either incubated in complete darkness up to hatching or were put into light one week before hatching. Control embryos were incubated under dim light conditions which corresponded broadly to the natural conditions. Under standardized imprinting conditions the controls and both groups of the light deprived ducklings showed the following response. Most of the dark-incubated embryos, however, did not distinguish between imprinting and test objects of different shapes. Since most of the embryos kept in darkness only for 21 days also failed to develop the capacity for shape discrimination, there is apparently a, critical period for light influences on the development of this capacity at some time during the early prenatal period.Acknowledgments. We are grateful to Dr E. Pröve for his advice on the carrying out of our imprinting tests, to K. Weigel for help with the drawings and to Dr. J. R. Wolff for helpful discussions.     

Inhibitory action of estradiol on testosterone production in rat embryo]

Embryos from Rats given an injection of 0,5-1 mg of oestradiol benzoate on days 17--19 of pregnancy show a 3--4-fold reduction in their testicular testosterone content with respect to the control embryos, 24--48 hrs later. OEstradiol most likely acts by inhibiting LH secretion, which in turn results in a lowered testosterone production.     

Palinurin,a new linear sesterterpene from a marine sponge

Summary The structure of a new linear sesterterpene, palinurin (1), obtained from the marine spongeIrcinia variabilis, was determined by spectral and chemical means.This work was carried out at the Progetto Finalizzato Oceanografia e Fondi Marini, C.N.R., Roma. We thank Professor M. Sarà (University of Genova) for the identification of the sponge, Mr C. Di Pinto for¹H-and¹³C-NMR, Mr G. Scognamiglio for technical assistance.     

Cytogenetic analysis of bone marrow cells and spermatogonia of male mice after in vivo treatment with arsenic

Summary Male Swiss Albino mice were injected i.p. with an As₂O₃ solution (0; 4; 8 and 12 mg As/kg) and sacrificed 12, 24, 36 and 48 h after injection. Neither chromatid nor chromosome aberrations were observed in bone marrow cells and spermatogonia.Acknowledgments. We thank Mr L. De Langhe for skillfull technical help. We acknowledge this work was supported by a grant of the Ministery of Public Health.     

The effect of 5-bromodeoxyuridine on mouse embryos during neurulation in vitro

Summary Mouse embryos explanted at various stages during neurulation were cultured for 20–28 h in the presence of 25–900 g/ml of 5-bromodeoxyuridine (BUdR). BUdR strongly inhibited closure of the cranial neural tube, which was found to be stage-dependent. When mouse embryos were exposed to BUdR after development of the concave curvature in the neuroepithelium of the midbrain to the upper hindbrain regions, they became insensitive to the drug-induced open cranial neural tube. Histological observations showed that BUdR interfered with interkinetic migration and cytokinesis of the neuroepithelial cells. These cellular abnormalities were not dependent on the morphological development of the cranial neural folds. The³H-BUdR experiment confirmed that the label was mostly incorporated into the DNA fraction.Acknowledgment. This work was supported by Grant-in-Aids for scientific research No. 557469 and 58480391 from the Ministry of Education, Japan.     

Kinetics of division in PHA-stimulated pig lymphocytes

Summary Our results indicate that pig lymphocytes in culture complete their 1st division at 24 h. At 36 h there are 9% of cells in 2nd division. 3rd mitosis appears at 48 h; and at 72 h there are cells engaged in the 4th division.This work was supported by grants from the International Atomic Energy Agency, the Organization of American States and the Consejo Nacional de Investigaciones Científicas y Técnicas.We wish to thank for the technical assistance of Mr J. Serraïno.     

Effects of puromycin on rat embryos in vitro

Summary Somite-staged rat embryos were exposed to varying concentrations of puromycin for 48 h in vitro. Medium concentrations below 0.92 M had no significant effects, while concentrations above 1.84 M were lethal. Between these extremes, there were concentration dependent increases in the incidence of malformations in a close relationship to growth retardation.     

The effect of hydrocortisone and thyroxine on development of calcium homeostasis in embryonic intestinal epithelium

Cytoplasmic Ca²⁺ concentration of epithelial cells from 14-day embryonic chick duodena decreased during 72 h of organ culture to a value 54% of that found at 17 days in vivo. The ability of cells to maintain a constant Ca²⁺ concentration when challenged with high extracellular calcium was also significantly reduced. Addition of 1 M hydrocortisone during culture restored both parameters of Ca²⁺ homeostasis to that of 16-day uncultured duodena, and rise in cytoplasmic Ca²⁺ was significant within 4 h of hormone treatment. Thyroxine influenced epithelial Ca²⁺ similarly, but to a lesser degree and only after 48–72 h of culture. These data indicate that glucocorticoids, and possibly thyroid hormones, influence the development of calcium homeostasis in intestinal epithelium.     

Inhibitory effect of fasting on the glucagon-induced increase of liver phosphorylase A activity in rats

Summary The increase of liver phosphorylase A activity observed 1, 2 and 3 min after i.v. administration of 0.1 g kg^–1 glucagon to fed rats was found to be completely absent in 24 h fasted animals, although there is even an exaggerated liver cAMP response to glucagon after fasting.Acknowledgments. We would like to thank Mrs M. Fritzová and Mr F. Kovai for expert technical assistance.     

In vitro inactivation of corpora allata of the bugOncopeltus fasciatus by precocene II

Summary Corpora allata fromOncopeltus fasciatus incubated in vitro in medium containing 10^–5.35 M (1 g/ml) of precocene II lose their ability to secrete juvenile hormone when reimplanted into last instar larvae.Acknowledgments. We thank Mr K. Dorn, Mrs L. Dolezal, Mrs V. Nötzli-Graf, Mr K.H. Trautmann and Mr A. Schuler for technical help, Dr W. Vogel and Dr A. Dübendorfer for valuable discussions.     

Blood pyruvate in cats after hydrocortisone hemi-succinate

Zusammenfassung Hydrocortison - Na - hemi - Succinat (100 mg des Steroids) lebenden, 4 1/2 h fastenden Katzen injiziert, ergab sofortigen Anstieg der Pyruvat-Konzentrationen im Blut mit nachfolgendem Blutzuckeranstieg.Injektionen von Kontrollösungen ergaben keine Reaktion. Nach Steroidgaben erfolgte sowohl bei normalen wie adrenolektomierten Tieren ebenfalls Anstieg.

---

---

I should like to thank Professors SirG. Pickering andI. E. Bush and Dr.R. V. Coxon for help and Mr.B. Abraham, MissS. Briers and Mr.W. Brown for technical assistance. Glaxo Laboratories Ltd. made a generous gift of the hydrocortisone-21-phosphate.     

The isolation and structure of 13,18-dehydroglaucarubinone,a new antineoplastic quassinoid fromSimarouba amara

Summary An investigation of the Guyana plantSimarouba amara Aubl. (Simaroubaceae) for antineoplastic quassinoids led to isolation and structural determination of the new quassinoids 2-acetylglaucarubine (1a) and 13,18-dehydroglaucarubinone (2). The previously known 2-acetylglaucarubinone (3a) and glaucarubinone (3b) were also obtained. The new quassinoid2 was found significantly to inhibit growth of the murine lymphocytic leukemia P388.Antineoplastic agents 59. For part 58 refer to M. T. Edgar, G.R. Pettit and T.H. Smith, J. org. Chem., in preparation.Acknowledgments. We wish to thank Mr B. Septe for providing the¹³C-NMR-data. Dr Jean H. Schmidt and Miss Linda M. Lange for assistance with biological studies.—G.R. Pettit is grateful to the National Cancer Institute (performed pursuant to contract No. N01-67048 with the Division of Cancer Treatment, NCI, National Institutes of Health, Dept. of Health, Education and Welfare), Public Health Services Research grant No. CA 16049-03 from the National Cancer Institute, the Fannie E. Rippel Foundation, Talley Industries, and the Phoenix Coca-Cola Bottling Co., for partial support of this investigation.     

Effects of hypo and hyperosmotic media on rabbit renal cortical slices

Summary Rabbit kidney cortex slices behave as osmometers when withstanding either hyperosmotic shocks or hypoosmotic shocks of amplitude up to P₁/P₂=1.25. For hypo-osmotic shocks of amplitude larger or equal to P₁/P₂=1.5 a volume regulation process occurs. Na⁺ is the main osmotic effector implicated in volume control.This work has been aided by a grant 1.5.422.82F from the FNRS to R.G. We wish to thank Mr J.M. Theate for his skilful assistance.     

Identification of (3R,4R)-gD 1(6) as an isolation artefact of cannabinoid acids formed by callus cultures ofCannabis sativa L

Summary For the first time we have isolated a major psychoactive cannabinoid, (3R, 4R)- ¹⁽⁶⁾-tetrahydrocannabinol3 from callus cultures ofCannabis sativa L.3 was obtained as an artefact of the actually formed (3R, 4R)- ¹-tetrahydrocannabinol-3- and/or 5-carboxylic acids1 and2 by subjecting the culture material to a decarboxylation step prior to extraction. No attempt was made to isolated acids1 and2. The identity of3 was confirmed by comparison with an authentic sample of (3R, 4R)- ¹-tetrahydrocannabinol. Culture conditions, isolation procedure and identification of the cannabinoid are described.Acknowledgment. The authors are greatly indebted to Dr W. Heller and Dr G. Schroeder-Frey for deriving the callus cultures from seedlings ofC. sativa and to Prof. N. Amrhein for valuable gifts of culture media and growth regulators.     

Etude comparative sur l'action de différents liquides (eau distillée,solution physiologique de chlorure de sodium,liquide de Tyrode) sur le développement de l'embryon de poulet

Summary The injection of small doses of distilled water, physiological solution of natrium chloride and liquid of Tyrode, is well tolerated by the embryos; large doses have a stronger lethal action. The three liquids have no specific teratogenic action. The injection of 1/10 cm³ of Tyrode at the 24th h of incubation seems to be the quantity of solvent and the period for the injection which are ideal for testing the effects of an hydrosoluble substance in the chick embryo.

---

---

Ces recherches ont été faites grâce à un subside du Fonds national suisse de la recherche scientifique et de la Fondation E. Barell.     

The induction of chromosome aberrations in human lymphocytes by negative π-mesons under conditions of anoxia and oxygenation

Summary After a dose of 3.0 Gy in the peak position of the pion depth-dose curve, the ratios between observed chromosome aberration yields under conditions of oxygenation and of anoxia were obtained for lymphocytes exposed at 3 depths in a plastic phantom. These ratios were 3.7, 1.9 and 1.3 in the plateau, peak and post-peak positions, respectively, suggesting a corresponding decrease in the oxygen enhancement ratio.Acknowledgments. We wish to thank Dr D.H. Reading, Mr M.A. Hynes and Mr W. Spinks for their assistance at the Rutherford Laboratory's -II beam line. This work was partly supported by Euratom Contract 171-76-1 BIO-UK.     

Ca-antagonistic substance from soft coral of the genusSarcophyton

Summary A 14-membered ring diterpenoid named cembrane, possessing Ca-antagonistic action on the isolated rabbit aorta, has been isolated from a soft coral of the genusSarcophyton, and its structure established by X-ray and spectroscopic data.The authors thank Mr. Z. Nagahama (Okinawa) for collection of soft corals, Miss R. Abe (the present institute) for her skillful assistance, and Dr. T. Higashijima, Prof. T. Miyazawa (Tokyo University), Mr. T. Hayase and Dr. H. Ohtani (Mitsubishi Chemical Industries Ltd) for¹H and¹³C NMR-measurements.     

Testicular Δ5-3β dehydrogenase,ascorbic acid and dehydroascorbic acid in actinomycin D-treated toads

Summary Unilaterally intratesticular injection of actionomycin D in toad inhibited ⁵-3 dehydrogenase activity with significant increase of dehydroascorbic acid and decrease of ascorbic acid level in the testis.Acknowledgments. Thanks are due to Prof. C. Deb, Department of Physiology, Calcutta University, for his suggestions and constant encouragment. Thanks are also extended to Mr R.K. Bhattacharya Microphotographer Department of Physiology, for his kind cooperation.