Na+/NH 4 + co-transport in isolated perfused gills of the Chinese crabEriocheir sinensis acclimated to fresh water

Summary In isolated perfused posterior gills ofE. sinensis acclimated to fresh water, NH ₄ ⁺ may be used as a counter-ion for Na⁺ active transport. This Na⁺/NH ₄ ⁺ coupled transport can, however, only account for a small part of the Na⁺ total active influx.Chargé de Recherches du FNRS-Acknowledgments. This work has been aided by a grant crédit aux chercheurs from the FNRS and by a grant No. 2.4511.76 from the FRFC.     

On the biosynthesis of neoflavanoids

Résumé Les hypotheses sur le mécanisme de la biosynthèse des néoflavanoïdes sont discutées sur la base de résultats de nos expériences d'incorporation dans leCalophyllum inophyllum.

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We thank the C.E.A. (Saclay) for a grant towards the purchase of labelled compounds, Mr.G. Henry for technical collaboration and the Comité de l'Accueil du Phytotron for culture facilities.     

An approach for the in vitro screening of drugs for activity against leprosy

Summary Slow growing strains of mycobacteria isolated from leprous tissues present a characteristic resistance pattern to antibacterial agents that is comparable to drug sensitivity ofM. leprae in man.The Hansen Chair of Research is a foundation of Le Secours aux Lépreux (Canada) Inc..     

Labelling of steroids in axillary sweat after administration of3H-Δ5-pregnenolone and14C-progesterone to a healthy man

Résumé L'administration intraveineuse du prégnène-3-ol-20-one[7-³H]- ⁵ avec le progestérone[4-¹⁴C] à un homme sain amena la sécrétion d'autant de radioactivité dans la sueur des aiselles que dans la plupart du reste du corps. Le prégnénolone- ⁵, l'androstène-3,17-dione- ⁴ et le déhydroépiandrostérone furent les principaux stéroïdes marqués identifiés comme partant des deux sources de sueur.

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Acknowledgments. The author expresses grateful thanks to the subject (A.C.) who subjected himself to this experiment, and to Mr. D. A. A.Wilson for his technical assistance.     

Properties of an auxin-oxidising system fromLactobacillus bulgaricus

Résumé Un traitement à l'acide-indolylacétique (IAA) a pour effet d'induire — chezLactobacillus bulgaricus — un système inactivant l'IAA. Le pH optimum de ce complexe enzymatique est de 6.0 et sa température optimale de réaction de 32 °C. Cette induction est inhibée par des analogues de l'IAA (acides-indolyl carboxylique et-indolyl propionique;dl-tryptophane). L'apparition de cette « IAA-oxydase » permet de rendre compte, dans une large mesure, des effets de l'IAA sur la croissance des microorganismes testés.     

Tartessol,a new diterpene fromSideritis grandiflora Salzm

Résumé Un nouveau diterpène tartessol (1) a été isolé de laSideritis grandiflora Salzm. (Labiées) est sa structure est proposée comme étantent-14-acétoxy-15-beyèren-18-ol.

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Part XVIII in the series Studies on diterpenes from genusSideritis. For Part XVII seeT. G. de Quesada, B. Rodríguez andS. Valverde,Phytochemistry, in press.

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The authors thank Dr.J. Borja, Botany Department, Faculty of Pharmacy, Madrid, for the collection and botanical classification of the plant material and Dr.Juana Bellanato, Institute of Optics, C.S.I.C., Madrid, for the high resolution IR spectra.     

Influence of adrenergic blocking agents upon morphine and catecholamine analgesic effect

Resumen Las catecolaminas adrenalina (0,25 y 0,5 mg/kg) noradrenalina (0,5 y 1 mg/kg) e isoproterenol (4 y 8 mg/kg) producen efecto analgésico significativo en lauchas. También aumentan (adrenalina 0,25 mg/kg, noradrenalina 0,5 mg/kg e isoproterenol 4 mg/kg) el efecto analgésico de pequeñas dosis de morfina (1 mg/kg). El bloqueador -adrenérgico dihidroergotamina (4 mg/kg) no influencia substancialmente estas acciones, pero el bloquente-adrenérgico propranolol (1 mg/kg) bloquea los efectos analgésicos de la morfina, adrenalina e isoproterenol, no siendo tan efectivo contra la noradrenalina. Se deduce que debe existir un compromiso de receptores-adrenérgicos en el mecanismo de los efectos analgésicos de las catecolaminas y también de la morfina.

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Fellow of the Consejo de Investigaciones Cientificas y Técnicas.     

Side-chain hydroxylation in the biosynthesis of β-ecdysone (20-hydroxyecdysone) in the blowflyCalliphora stygia

Résumé Dans la mouche a viandeCalliphora stygia le 25-hydroxycholesterol et le (22R)-22-hydroxycholesterol sont incorporés a la -ecdysone (20-hydroxy-ecdysone) beaucoup moins qu'au cholesterol et ne sont donc probablement pas des précurseurs de cette hormone.     

Chromosomal translocations in 2 Italian populations ofReticulitermes lucifugus (Rossi) (Insecta,Isoptera: Rhinotermitidae)

Summary The chromosomes of 2 Italian populations ofReticulitermes lucifugus (Rossi) were studied in both spermatogonial and oogonial divisions. The diploid chromosome complement is 2=42. All the first meiotic metaphases in Sardinian males show a complex translocation arranged in chains of 4 bivalents. The Apulian males show either 21 bivalents or 19 bivalents and a chain of 2.The authors express their thanks to Prof. A. Springhetti for his kind help in supplying the materials and for criticism in preparation of this paper, and to Prof. G. Colombo for valuable advice and criticism.     

Use of the exo-β-(1→3) glucanase from basidiomycete QM 806 in studies on yeast

Résumé L'exo--(13) glucanasem isolée duBasidiomycete QM 806 a été utilisée avec succès pour l'analyse des polysaccharides de la paroi cellulaire de la levureSaccharomyces cerevisiae et pour la formation de protoplastes à partir deSaccharomyces cerevisiae etWickerhamia fluorescens.

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Acknowledgments. We are indepted to MissE. Sigarlakie and MissE. Wespi for technical assistance during the course of this investigation.     

MultipleW chromosome in a sea snake,Enhydrina schistosa daudin

Résumé Un serpent marin (Enhydrina chistosa Daudin, Hydrophiidae) a 32 chromosomes chez le , 33 chez la , cette dernière ayant unW-chromosome supplémentaire. La digamétie serait: -ZZ; Z W ₁W₂.

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The author is indebted to Prof. S.P. RayChaudhuri for guidance and the University Grants Commission, India, for financial assistance.     

New phytotoxic butenolides produced bySeiridium cardinale,the pathogen of cypress canker disease

Summary Two new butenolides, seiridin andiso-seiridin, were isolated from culture filtrates ofSeiridium cardinale, the pathogen of cypress canker, a destructive disease ofCupressus and relatedConiferae These metabolites were characterized as 3-methyl-4-(2-hydroxyheptyl)-2(5H)-furanone and its 4-(3-hydroxyheptyl) isomer, respectively. Chlorotic, and necrotic symptoms were produced on leaves of either host or non-host test plants by absorption of 0.3 mg/ml solutions of either compound. These also showed antibacterial activity.This study was supported in part by the National Research Council, Rome (special ad hoc project Chimica fine e secondaria) and in part by the Ministry of Education, Rome.     

A new indolic antiauxin, α-(5,7-dichloroindole-3-)isobutyric acid: its chemical synthesis and biological activity

Summary A new potent antiauxin, -(5,7-dichloroindole-3-)isobutyric acid has been synthesized and shown to inhibit auxin-mediated elongation ofAvena coleoptiles and to stimulate root growth of rice seedlings. Its activity is stronger than -(p-chlorophenoxy)isobutyric acid and is comparable to that of 2,3,5-triiodobenzoic acid, which are typical antiauxins.     

Effect of genome size andrrn gene copy numbers of PCR amplification products of 16S rRNA genes from mixed bacterial species

Results and conclusion As determined by image analysis of SYBR green-stained amplification products the experimentally determined ratio corresponded well with the expected ratio calculated from the number ofrrn genes per equimolar amount of DNA in mixtures containing DNA ofEscherichia coli and Thermus thermophilus and DNA ofPseudomonas aeruginosa and T. thermophilus. The values for the pairBacillus subtilis and T. thermophilus showed higher deviation from the predicted value. The dependence of the amount of 16S rDNA amplification products on these two parameters makes it impossible to quantify the number of species present in 16S rDNA clone library of an environmental sample, as long as these two parameters are unknown for these species.     

Synthesis and preliminary biological investigation of several N-alkyl aspartic acid derivatives

Résumé L'acide N-furfuryl aspartique et l'acid N-(méthyl-6-heptyl)-2 aspartique permettent la croissance deL. mesenteroides P-60 en absence de l'acide aspartique et de l'asparagine. Ces 2 composés et leurs esters-méthyliques s'avèrent toxiques pourE. coli 9723.     

fferences in the number of molecules produced by two allelic electrophoretic enzyme variantsD. melanogaster

Résumé Les techniques immunologiques ont démontré que chezDrosophila melanogaster une forme électrophorétique «Fast» d'alcool déshydrogénase produit plus de molécules d'enzyme qu'une forme électrophorétique Slow. On expose les résultats en les comparant à d'autres suggérant des mécanismes autorégulatoire.

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Acknowledgement. I am grateful to Dr.D. Roberts for helpful discussions.     

Running activity of ovarian tumorigenic mice

Résumé Les ovaires de souris C3B6F1, génotypeW ^xW^v développent des adénomes tubulaires à l'âge de 7 mois. Dans l'essai du tread wheel l'activité spontanée de ces animaux était plus petite que celle des contrôles.     

Antimicrobial metabolites of the marine spongeAxinella polycapella

Summary Extracts of the marine spongeAxinella polycapella contain 1,2,4-trihydroxybenzene (1) and 2,2,4,4,5,5-hexahydroxybiphenyl (3) as antimicrobial constituents. Methods of synthesizing3 by, oxidative dimerization of1 were examined.Acknowledgment. We are grateful to Dr Klaus Reutzler for identifying the sponge and one of us (SW) is pleased to acknowledge fellowship support (1-F32-AI_05883-02) from the Public Health Service.     

A simple synthesis of (E)-3-formylbut-2-enenitrile,and its use as a precursor of isotope-labelled zeatin and (±) dihydrozeatin

Summary (E)-3-Formylbut-2-enenitrile (4) is synthesized in 2 steps by reacting pyruvaldehyde dimethylacetal and acetonitrile in the presence of sodium methoxide, followed by acid hydrolysis to give 58% overall yield on distillation. The aldehyde4 can be stepwise and selectively reduced to (E)-3-hydroxymethylbut-2-enylamine (7a) in 37% total yield or exhaustivelyb reduced in 1 step to (±)-4-hydroxy-3-methylbutylamine (6) in 46% total yield. Compound7a and6 can be condensed with 6-chloropurine to give zeatin and (±)dihydrozeatin respectively. This provides a readily accessible method for isotope-labelled zeatin and its derivatives at side chain.Contribution No. 1064, Alberta Research CouncilProcess for the Preparation oftrans-3-formylbut-2-enenitrile S. Chen and J. MacTaggart, patent applicatioin registered in Canada and the United States of America.Acknowledgment. The author thanks Mr J. M. MacTaggart and Mrs C. M. Goulet for valuable experimental assistance and Dr R. M. Elofson for helpful discussions.     

(Z,E)-α-farnesene,main constitutent of the hypertrophied Dufour's gland of the major workers ofPheidole pallidula (Formicidae)

Summary In the European dimorphic ant,Pheidole pallidula, the Dufour's gland of the major workers is hypertrophied and secretes nearly pure (Z, E)--farnesene. This compound is also present in the Dufour's gland of the minor workers but constitutes only around 10% of the volatiles. Chemical polymorphism inP. pallidula is different from that already reported for species ofPheidole from the New World.Aspirante au Fonds National de la Recherche Scientifique.Maître de recherches du Fonds National de la Recherche Scientifique.