X-irradiation of mice in early fetal period influences dose-dependently sex ratio of offspring until weaning

Summary Fractionated X-irradiation of mouse fetuses on gestation days 11–13 resulted in a significantly increased postnatal mortality of female litters. This occurred only at 3×110 rad, which was the threshold for the formation of typical neuroepithelial, rosette-like malformations.We are greatly indebted for the technical assistance of Miss C. Gutmann, Mrs I. Hempfling and Mrs K. Pfaff.     

Sexual dimorphism of mouse fetal brain lesions after X-irradiation prior to gonadal differentiation

Fractionated X-irradiation of gestational days 11-13 in the mouse, with doses between 3 x 1.05 and 3 x 1.33 Gy resulted in rosette-like clusters of primitive ependym-resembling cells dispersed within the cortex walls. Quantification of these abnormalities showed a general prevalence in the female fetuses, especially due to the larger number of rosettes in the females than in the males. It was concluded that X-irradiation acts on sex-specific differentiation steps, which are fully developed at the beginning of the fetal period. As it was recently speculated that these are linked to an early divergence of gene expression between the sexes, we suggest that X-chromosome damage may be involved in the pathogenesis of the dimorphic lesion pattern. While, in principle, this will valid for any fetal tissue, it only becames evident in the forebrain because of the outstanding relationship between cell necrosis and rosette development in this specific organ.     

Synthesis,crystallization and properties of acetyl phenylalanyl lysine chloromethyl ketone: A potential inhibitor of serine proteases

Summary A procedure for the synthesis of acetyl phenylalanyl lysine chloromethyl ketone is described. The chloromethyl ketone derivative is a noncompetitive inhibitor of trypsin (K₁=5.9×10^–3 M).Acknowledgments. The authors are grateful to Dr Arthur L. Bacon for his constant support and encouragement. Special thanks are due to Dr William Kray for initiating this research project. We thank Mrs Juliette Barclay, Ms Earlene Spratling and Ms Ollivette Hill for their technical assistance in conducting some of the experiments. This investigation was supported by MBS grant RR8105 from the General Research Support Branch, Division of Research Resources, National Institutes of Health.     

Liver enzyme induction by the anion exchanger resin,Dowex 1×2, in the rat

Summary Peroral treatment of rats with the anion exchanger resin, Dowex 1×2, for 8 days leads to liver enlargement and increase of alkaline and acid phosphatases, glucose-6-phosphate dehydrogenase, malic enzyme, catalase, and the enzymes of microsomal drug metabolism in the liver. The sequestration of bile acids by this treatment mimics the biochemical effects of clofibrate- and phenobarbital-like drugs in the liver.Acknowledgment. The authors want to thank Mrs Fey, Mrs Kremer and Mr Weinrauch for their skilful technical assistance.     

Effect of various solubilizers on angiotensinII receptors in bovine adrenocortical plasma membranes

Summary 3 monionic detergents, Triton X-100, Lubrol WX and NP-40, inhibited binding of [³H]-AT_II to bovine adrenocortical plasma membranes. This effect appeared to be direct and not due to solubilization of the AT_II receptor by these agents. Sodium deoxycholate and the chaotropic ions, ClO ₄ ^– and Br^–, produced effects similar to the nonionic detergents.Supported by grants from the Quebec Heart Foundation and the Medical Research Council of Canada. The authors acknowledge the technical assistance of Mrs D. Michaud and the secretarial aide of Mrs D. Huot-Blais, and Miss L. Leblanc.     

An extremely cadmium-sensitive strain ofChlorella

Summary Growth of 14 strains from fiveChlorella species is rather insensitive towards cadmium. One strain (211-1a) ofC. saccharophila, however, was found to have a sensitivity towards this toxic heavy metal about 100 times higher than that of the other strains ofC. saccharophila.Acknowledgment. For excellent technical assistance I am indebted to Mrs U. Knoch and Mrs E. Weitemeyer.     

Reversal of metamorphosis in mealy bugs treated with juvenile hormone-active insect growth regulator

Summary Anal pore-plates are a typical adult characteristic of male mealy bugs. Nymphs treated with a juvenile hormone-active insect growth regulator moult several times into intermediary forms between nymph and adult. The number of the anal pores is reduced during each of these supernumerary moults.Presented at the XVth International Congress of Entomology, Washington DC 1976.Acknowledgments. We wish to express our thanks to Sir Vincent B. Wigglesworth and Mr M. Gruber for revision of the text and to Mr M. Dickenmann and Mrs B. Mühlemann for technical assistance.     

Stimulatory effect of methyl jasmonate on the ethylene production in tomato fruits

Summary Methyl jasmonate at a concentration of 0.5% in lanolin paste was applied to detached mature green and red ripe tomatoes cv. Tempo. One to 10 days after treatment, slices were cut at a depth of about 2 mm for ethylene determination. It was found that methyl jasmonate strongly stimulated ethylene production both in green and red fruits, production was about 1.6 to 7.9 times higher than in control tissue.Acknowledgments. We wish to thank Dr E. Demole, Firmenich SA, Geneva, Switzerland, for the gift of authentic (±)-methyl jasmonate and Mrs H. Sas for her excellent technical assistance.     

Night pineal N-acetyltransferase activity in rats exposed to white or red light pulses of various intensity and duration

Summary Night N-acetyltransferase activity is suppressed by red and white light; the red light intensity, however, must be 10 times higher. Short light pulses also suppress night N-acetyltransferase; the higher the light intensity, the shorter the pulse is effective.The authors are grateful to Mrs Marie Svobodová for her skillful technical assistance.     

Suramin stimulates renal growth in the rat

Summary Suramin given to rats in a single high dose (20 mg/100 g i.v.) stimulated renal growth. Maximum changes are taking place after 6–9 days of treatment.Suramin (Bayer 205) was generously provided by bayer (Leverkusen, Federal Republic of Germany).The authors thank Miss J. Telegdy and Mrs I. Harmos for technical assistance and Mrs M. Herczeg for the preparation of the sections.     

Influence of cyclic nucleotides on protein synthesis in vascular smooth muscle

Summary The incorporation of leucice-¹⁴C into protein in bovine mesenteric arteries was augmented by cyclic GMP (10^–3 M) and decreased by cyclic AMP (10^–3 M). There was no effect of 5 AMP (10^–3 M). The phosphodiesterase inhibiting drugs theophylline (10^–3 M) and papaverine (5×10^–5 g/ml) both decreased the leucine-¹⁴C incorporation.We are indebted to Mrs.Lena Burlin for hear assistance. Finacial support has been provided by the Swedish State Medical Research Council (No. 04X-101X-4498).     

The number of parallel fibre-Purkinje dendrite synapses. A morphometric evaluation

Summary Quantitative parameters concerning synapses were studied in the cerebellar molecular layer of 4 cats using ultrastructural morphometric methods. The number of parallel fibre-Purkinje dendrite synapses was estimated to be about 200,000.This study was granted by I.N.I.C. (Centro de Morfologia Experimental—MbP₁ e Centro de Anatomia Patológica e Oncologia-MbP₃).The authors thank Mrs M.L. Brito, Mrs M.A. Nascimento, Mrs M.G. Rodrigues and Mr L.B. Nunes for their technical assistance.     

Patterns of membrane organization in toad bladder epithelium: A freeze-fracture study

Summary Two cell-types of toad bladder epithelium show uncommon plasma membrane organization in freeze-fractured specimens. One type, the granular cell, contains a plasma membrane in which the A-face is poorly particulate luminally while the B-face discloses multiple large particles at this site. In contrast, the lateral and basal portions of the granular-cell membrane are typical in that more particles occupy the A-face than the B-face. In the other cell-type, which is mitochondriarich, the plasma membrane, luminally, laterally, and basally, contains rod-shaped and a few glubular particles in the A-face. We suggest that these two peculiar membrane organizations by considered in the localization of both vasopressin and aldosterone action in toad bladder.Some of these results were presented in abstract form at the 6th annual meeting of the Swiss Societies for Experimental Biology, Lausanne, 11–12, May 1974²¹ The authors are indebted to Mrs.Marthe Sidler-Ansermet, Mrs.Gorana Perrelet, MissMariella Ravazzola and Mr.Michel Bernard for valuable assistance.This work was supported in part by grants No. 3.0311.73, 3.8081.72, 3.553.75 and 3.1300.73 from Fonds National Suisse de la Recherche Scientifique, Bern, Switzerland, and by a grant-in-aid from Hoechst-Pharmaceuticals (Frankfurt-Hoechst, W. Germany).     

Effect of air ionization on blood serotonin in vitro

Summary The effect of negative and positive air ionisation on siliconized blood serotonin was studied in vitro. The experiments showed that within 10 min positive ionisation increased serotonin levels in total blood (+40%), plasma (+90%), erythrocytes (+50%) and thrombocytes (+200%). On the other hand, negative ionization (10 min) lowered the serotonin content of total blood (–30%), plasma (–42.5%), erythrocytes (–41.7%) and thrombocytes (–72.3%), thus confirming the Krueger Effect in vitro.This research was generously supported by a grant from the Joint Research Fund of the Hebrew University and Hadassah, and Dr. and Mrs.Leonard Appleby of Palmbeach, Florida.Acknowledgment: Our thanks are due to Mr.B. Shalita, Mrs.Zippora Adar and Mrs.Olga Fradkin for devoted technical assistance.     

Arylsulphatase in growing bones of rat

Summary Soluble arylsulphatase purified from growing bones of rats was fractionated into 3 components with mol. wt of 32,000–36,000, and characteristics similar to arylsulphatase B of other tissues. Serum strongly inhibited the 2nd component, slightly activated the 3rd and had no effect on the 1st.Grants of the National Research Council for Medical Sciences and Sigrid Jusélius Foundation, Finland.Acknowledgement. The authors are grateful to Mrs P. Peronius for her skillful technical assistance.     

External strontium and contractility in single giant muscle fibers of the barnacle

Summary Isometric tension and membrane potential in response to electrical stimulation have been studied on single giant muscle fibers of the barnacle upon replacement of external calcium with strontium. Under these conditions, the membrane response showed after the normal peak depolarization, a plateau phase lasting 3–7 sec before repolarization took place, while the force of contraction showed a linear relation with external strontium concentration. A direct action of strontium ions on contractile proteins (namely troponin) can be ruled out in favor of a triggering action on the sarcoplasmic reticulum, which, in turn, leads to calcium release and development of tension.Acknowledgment. I wish to thank Dr C. C. ashley in whose laboratory the research reported in this paper was performed, and Mrs L. M. Castell for invaluable technical assistance. This work was supported by grant No. 106140/048104235 from Consiglio Nazionale delle Ricerche, Italy.     

Cold stress induced changes in the uptake and distribution of radiolabelled magnesium in the brain and pituitary of the rat

Résumé L'imposition de conditions hypothermiques augmente l'incorporation de²⁸Mg dans le cerveau et la glande pituitaire du rat.

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Research for this paper was supported by NSF No. GB 27740 X. The authors are grateful for the technical assistance of Mrs.M. Turner, Mrs.E. Rovner and Mrs. L. Macko.     

Impaired proximal tubular transport functions in anaesthetized splanchnicotomized dogs

Summary The maximal tubular transport of inorganic phosphate,d-glucose and para-aminohippuric acid, respectively, was depressed on the denervated side in unilaterally splanchnicotomized, anaesthetized dogs. It is concluded that renal sympathetic activity might in general regulate proximal tubular transport functions.The authors are indebted to Mrs V. Vajda, Mr A. Karai, Mrs K. Kéry, Mrs B. Asztalos, Mr S. Szécsi and Mr J. Vártok for their valuable technical assistance.     

Effects of various media on tissular and cellular structures of the superior cervical ganglion of the rat

Summary The superior cervical ganglia of the rat have been incubated in vitro for 1 h in basal medium Eagle (BME) with Hanks' salts, BME with Earle's salts, Krebs' solution and NCTC 109 medium. Comparison of the cell areas, established by a semi-automatic quantitative method, shows that the three former induce a 30–35% neuronal retraction, whereas NCTC 109 has no effect. Thus this latter medium seems the best one for studies using incubation of these cells.We are indebted to Miss M. Vio, Mrs J. Bottini, Mr C. Cataldo and Mr P. Cau for their helpful assistance.     

Abnormal organization of ovarian follicles in the mutantl(1)su(f) mad-ts ofDrosophila melanogaster

Summary The morphology of ovarian follicles in the temperature-sensitive female-sterile mutantl(1)su(f) ^mad-ts has been studied by means of light and electron microscopy. As the follicle cells gradually degenerate at the restrictive temperature (29°C) the follicles become increasingly disorganized with respect to shape and polarity.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 46). We wish to thank Mrs R. Koppa for excellent technical assistance and Mrs G. Mahlke for photographic work. We are also indebted to Dr D. Zissler, Dr E. Gateff and Prof. K. Sander for many helpful suggestions.