Ultramikromethoden. Darstellung von Diazomethan; Methylierung von Fettsäuren mittlerer Kettenlänge

Summary A device for the small-scale generation of diazomethane is described, as well as the methylation by this reagent of nanogram amounts of the following fatty acids: butyric, caproic, caprylic, capric, lauric.

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3. Mitteilung:S. Huwyler, Experientia28, 1393 (1972).

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Herrn Prof. Dr.M. Viscontini danke ich für wertvolle Diskussionen und dem Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung für die finanzielle Unterstützung.     

Amino acid requirements of the bugDysdercus similis freeman (hemiptera: Heteroptera)

Summary The amino acid requirements for moulting, growth and development ofDysdercus similis have been investigated. The insects could not moult and reach maturity when given 10 essential amino acids only. However, if these were supplemented either with glutamic acid, glycine or aspartic acid growth and moulting was found to be normal.Dysdercus has an unusual synthetic mechanism for converting tyrosine into phenylalanine.The author is grateful to Prof.R. S. Saini for his guidance, critical discussions and encouragement.     

Sulfamidés et acides nucléiques

Summary The ribonucleic and thymonucleic acids are antisulphamide forEremothecium Ashbyii and for aSaccharomyces. This effect is due partly to purines, first of all to adenine, but not to any pyrimidines. ForSaccharomyces, the action of adenine is 1/10 of that of PAB acid. The suggestion is made that the bacteriostatic effect of the sulphamide is connected with the nucleic acids of the cytoplasma and the nucleus. Those are studied cytologically with help of the ribonuclease-method ofBrachet. Strong differences appear between the normal cells and the intoxicated ones.     

Über die Fettsäuren aus Spinatchloroplasten

Summary The fatty acids of two samples of chloroplasts fromSpinacia oleracea have been investigated quantitatively. They contain many polyenoic fatty acids (more than 70% of the total fatty acids); amongst these, a relatively high content of C¹⁶-trienoic acid is remarkable. Moreover, the presence of the ³-trans-hexadecenoic acid, recently detected in plants, is noteworthy.     

La libération des deux acides nucléiques au cours de l'autolyse des bactéries et sa signification

Summary The existence of a process of directed mutation for aBacterium coli through the action of the desoxyribonucleic acid released by anotherBacterium coli during its autolysis raises the question of the behavior of the two sorts of nucleic acids during the autolytic desintegration of the bacterial cell. Working with several germs, we have seen that autolysis releases a nucleoproteidic fraction containing from 20 to 30 per cent of nucleic acid. The desoxyribonucleic acid represents 50 to 70 per cent of the total nucleic acid; this value is very much higher than that of the initial germs, which contain but 20 to 30 per cent. The signification of the easy mobilization of the desoxyribonucleic acid by autolysis is discussed, according to the observations made in usingRobinow's method of nuclear staining.     

Arginine-vasopressin,lysine-vasopressin,and oxytocin,C14-labeled in the glycine residue

Zusammenfassung Die Synthese von Arginin-Vasopressin, Lysin-Vasopressin und Oxytocin, deren Glycinrest eine¹⁴C-Markierung trägt, wird mit Hilfe der Festkörpermethode nachMerrifield beschrieben.

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Supported by National Institutes of Health grants No. AM-13567 and No. AM-10080 and the Atomic Energy Commission.

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Abbreviations follow the rules of the IUPAC-IUB Commission on Biochemical Nomenclature in Biochemistry5, 2485 (1966). All optically-active amino acids are ofl-configuration. The following additional abbreviations were used: N-hydroxysuccinimide ester (OSu), ethanol (EtOH), methanol (MeOH), acetic acid (AcOH),n-butanol (n-BuOH), pyridine (Pyr) and N,N-dicyclohexylcarbodiimide (DCCI). Protected peptides and hormones were visualized on thinlayer plates according to the procedure byH. Zahn andE. Rexroth, Z. analyt. Chem.148, 181 (1955). The biological activities of the hormones were measured against the U.S.P. Posterior Pituitary Reference Standard; the four-point design was used for these bioassays and standard errors were calculated according to the method ofC. I. Bliss,The Statistics of Bioassay (Academic Press, New York, N.Y. 1952).

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Acknowledgments. The authors wish to thank Mr.D. Schlesinger for some of the amino acid derivatives used, and MissM. Wahrenburg and Mrs.A. Silverman for bioassays.     

Long-chain fatty acid uptake by skeletal myocytes: a confocal laser scanning microscopy study

Studies of regulation of free fatty acid (FFA) utilization by skeletal muscles have focused on plasma FFA delivery and on intracellular factors affecting FFA metabolism. The present study was conducted to directly analyse the uptake process of fatty acids into single myocytes. Cells were isolated from the rat flexor digitorum brevis muscle. Confocal laser scanning microscopy was utilized to analyse the uptake of the fluorescent fatty acid derivative 12-NBD-stearate, which is not metabolized by muscle tissue. Uptake represented a saturable function of the unbound fatty acid concentration in the medium (K _m 366 ± 118 nM, V _max 2.1 ± 0.3 AU/s) and depended on the medium sodium concentration. Reduced buffer pH increased initial uptake rates, whereas lactate (10 mM) had no effect. Membrane hyper- and depolarization decreased uptake rates. This study demonstrates for the first time kinetic data from isolated myocytes with evidence for a carrier-mediated transport mechanism for long-chain fatty acids. Received 31 March 1998; accepted 8 May 1998     

Incorporation of photolabile azido fatty acid probes inNeurospora crassa andSaccharomyces cerevisiae

Summary Photolabile azido fatty acids supported the growth of fatty acid auxotrophs, thecel mutant ofNeurospora crassa and the KD115 mutant ofSaccharomyces cerevisiae. These fatty acids were incorporated into the membrane lipids of thecel and KD115 mutants, but were not used by the wild type strain.This work was presented at the 26th International Congress of Pure and Applied Chemistry, Session 1, Tokyo, September 4–10, 1977, abstracts p. 241.Support was provided by the Govt. of India to B.C. and by NCERT, New Delhi India to D.N.C.To whom requests for reprints should be sent.     

Diterpene acids as larval growth inhibitors

Summary Kaurenoic and trachylobanoic acids from sunflower inhibited larval development in several Lepidoptera species. The tricyclic resin acids were also effective in curtailing growth ofPectinophora gossypiella and either reduction to carbinol or esterification of the carboxyl group lowered activity. Partial reversal of growth inhibition in the presence of relatively large amounts of cholesterol suggests an interaction with the insects' hormonal system.Acknowledgment. We wish to thankM. Rose andJ. Baker for insect bioassays.     

The effect of endotoxin on membrane fatty acid composition in BCG-sensitized mice

Summary The effects of endotoxin on mouse liver phospholipid fatty acid composition have been investigated. Administration of endotoxin fromSalmonella abortus equi led to a decrease in the polyunsaturated fatty acid content of livers from mice sensitized with Bacille Calmette Guérin (GCG). The content of arachidonic acid fell significantly in both the phosphatidylcholine and phosphatidylinositol fractions whereas in the phosphatidylethanolamine fraction the linoleic acid content was significantly reduced. The polyunsaturated fatty acids were replaced by increased amounts of oleic acid and palmitic acid, leading to a reduction in the polyunsaturated to saturated fatty acid ratio.     

Über den Einbau von Dipeptiden in Ergotoxin-Alkaloide

Summary l-Valyl-l-leucine-U-¹⁴C,l-valyl-l-proline-U-¹⁴C-lactam andl-leucyl-l-proline-U-¹⁴C-lactam were administered to submerged cultures of an ergotoxine-mixture-producing strain ofClaviceps purpurea. The added dipeptides were split by the fungus into the corresponding amino acids prior to incorporation. Apparently dipeptides are no immediate precursors for the peptide side-chain of ergotoxinealkaloids.     

Teratologische Prüfung der Hydrolysenprodukte des Thalidomids

Summary N-(o-Carboxybenzoyl)-dl-glutamic acid imide anddl-glutamic acid imide · HCl did not lead to fetal malformations after i.p. administration to pregnant mice; the injected solutions contained 25% Tween 20. Thus, of the 12 hydrolysis products of thalidomide only those 3 which contain the phthalimide moiety show teratogenic activity, i.e. 2-phthalimido-dl-glutaramic acid, 4-phthalimido-dl-glutaramic acid and 2-phthalimido-dl-glutaric acid.     

Stéréochimie d'acides grasα-hydroxylés isolés d'une souche deStreptomyces

Summary A strain ofStreptomyces contains a mixture (ca. 3:1) of 2d-hydroxy-12l-methyltetradecanoic and 2d-hydroxy-13-methyltetradecanoic acids; it has the same properties as a similar mixture prepared by synthesis.

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11e Communication sur la chimie des micro-organismes; 10e communication:C. Lacave, J. Asselineau etR. Toubiana, Europ. J. Biochem.2, 37 (1967).     

Uptake ofl-glutamate andl-aspartate in neurones and glial cells of cultured human and rat spinal cord

Summary Autoradiographic investigations on the uptake ofl-glutamate andl-aspartate have shown that the amino acids were taken up by neurones as well as by glial cells of cultured human and rat spinal cord. The activity of glutamate and aspartate varied considerably between individual neurones, whereas glial cells showed a more even distribution of the labelled amino acids. Our results suggest that both neurones and glial cells are involved in the uptake of amino acid transmitters.     

Furan fatty acid steryl esters from the marine spongeDictyonella incisa which show inflammatory activity

Summary Three new furan fatty acids, (9Z, 19Z)-3, 6-epoxyhexacosa-3,5,19-tetraenoic acid (1a), (8Z, 11Z, 14Z, 17Z)-3, 6-epoxyeicosa-3,5,8,11,14,17-hexaenoic acid (2a), and (8Z, 11Z, 14Z, 17E)-3, 6-epoxyeicosa-3,5,8,11,14,17-hexaenoic acid (3a), and a new polyunsaturated fatty acid (5Z, 8Z, 11Z, 14Z, 17E)-eicosa-5,8,11,14,17-pentaenoic acid (6a), present in the spongeDictyonella incisa as the respective steryl esters, have been isolated as methyl esters and their structures have been determined by spectral and chemical analysis. The furan fatty acid esters have shown a high inflammatory activity, which suggests their potential role as feeding deterrents.     

Über die metabolischen wirkungen einiger neuerβ-adrenergischer Stimulatoren

Summary Actions of various adrenergic drugs (adrenaline, noradrenaline, isoprenaline, metaproterenol, terbutaline, salbutamol, soterenol, quinterenol, chlorprenaline) on the glycemia and on free fatty acids of the rat have been described.

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Der Autor dankt fÜr die technische Mitarbeit den Herren B.Ungaro, L.Giordano und C.Vacca sowie fÜr die freundliche Überlassung von Noradrenalin, Adrenalin, Isoprenalin, Metaproterenol und Kö 592 der C. H. Boehringer Sohn A.G., von Terbutalin der AB Draco-Astra, von Salbutamol der Allen and Hanburys Ltd., von Soterenol dem Mead Johnson Res. Center, von Chlorprenalin den Lilly Res. Lab. und von Quinterenol der Chas. Pfizer Co.     

Genetische und biochemische Untersuchungen über die Bedeutung der Amino- und Nucleinsäuren im Ursachengefüge von Neoplasmen (Tumoren und Gallen). Ein Dauermodifikationsbzw. Prädeterminationsphänomen

Summary If certain hybrids ofPlatypoecilus maculatus andXiphophorus helleri (viviparous platyfish and swordtails) are cultivated in diluted sea-water (0.25 or 0.5% salt concentration), the amount of free amino acids increases and the growth of macromelanophores, which normally only form certain black spots at the dorsal fin, is accelerated. Therefore melanomas arise. After changing salt water for fresh water, growth of macromelanophores remains accelerated. The same effect is seen in progenies which have been in an oocytic or embryonic state, when their mother was cultivated for some weeks in diluted sea-water (Figures 1 and 2). A similar effect has been observed in plant galls produced byPhylloxera (Viteus vitifolii) in the genusVitis. When the parasite, which injects amino acids into the tissue of the host in order to produce galls, is removed, gall formation goes on slowly for some days. It is shown that a few hours after injection of amino acids—before formation of neoplasms begins—the concentration of ribonucleic acids is increased. RNS-(and therefore protein-)biosynthesis in neoplasms may be dependent on concentration of free amino acids. A simple concept for the formation of neoplasms in hybrids of platyfish and galls ofPhylloxera is discussed.

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Den Herren Prof. Dr.G. de Lattin (Zoologisches Institut der Universität des Saarlandes) und Prof. Dr.B. Husfeld (Forschungsinstitut für Rebenzüchtung Geilweilerhof/Pfalz) sind wir für die Förderung dieser Arbeit zu grösstem Dank verpflichtet. Herrn Prof. Dr.C. Kosswig (Zoologisches Institut der Universität Hamburg) verdanken wir viele Anregungen und die freundliche Überlassung von ingezüchteten Stämmen für unsere Fischkreuzungen. — Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Ultrastructural changes of the luminal plasma membrane of the transitional epithelium of the rat urinary tract in essential fatty acid deficiency

Summary Rats fed an essential fatty acid deficient diet (EFAD) showed a statistically significant decrease in the thickness and ultrastructural asymmetry of the luminal membrane and cytoplasmic vesicles of transitional epithelium of the urinary tract, due to a marked thinning of the peculiar thick luminal leaflet. These changes were reversed by adding EFA to the diet. This indicates that the unusual EM appearance of urothelial membrane depends on its content in EFA.Acknowledgment is due to Mrs.M. G. Iwakawa andN. T. Benítez for technical help and Mr.J. Hiza for animal care.D. Lis andA. Eynard are research fellows of Consejo Nacional de Investigaciones Científicas y Técnicas. Work supported in part by CONICET, Argentina.     

Metabolism of the neuromodulator d-serine

Over the past years, accumulating evidence has indicated that d-serine is the endogenous ligand for the glycine-modulatory binding site on the NR1 subunit of N-methyl-d-aspartate receptors in various brain areas. d-Serine is synthesized in glial cells and neurons by the pyridoxal-5′ phosphate-dependent enzyme serine racemase, and it is released upon activation of glutamate receptors. The cellular concentration of this novel messenger is regulated by both serine racemase isomerization and elimination reactions, as well as by its selective degradation catalyzed by the flavin adenine dinucleotide-containing flavoenzyme d-amino acid oxidase. Here, we present an overview of the current knowledge of the metabolism of d-serine in human brain at the molecular and cellular levels, with a specific emphasis on the brain localization and regulatory pathways of d-serine, serine racemase, and d-amino acid oxidase. Furthermore, we discuss how d-serine is involved with specific pathological conditions related to N-methyl-d-aspartate receptors over- or down-regulation.     

Emerging knowledge of regulatory roles of <Emphasis Type="SmallCaps">d-</Emphasis>amino acids in bacteria

The d-enantiomers of amino acids have been thought to have relatively minor functions in biological processes. While l-amino acids clearly predominate in nature, d-amino acids are sometimes found in proteins that are not synthesized by ribosomes, and d-Ala and d-Glu are routinely found in the peptidoglycan cell wall of bacteria. Here, we review recent findings showing that d-amino acids have previously unappreciated regulatory roles in the bacterial kingdom. Many diverse bacterial phyla synthesize and release d-amino acids, including d-Met and d-Leu, which were not previously known to be made. These noncanonical d-amino acids regulate cell wall remodeling in stationary phase and cause biofilm dispersal in aging bacterial communities. Elucidating the mechanisms by which d-amino acids govern cell wall remodeling and biofilm disassembly will undoubtedly reveal new paradigms for understanding how extracytoplasmic processes are regulated as well as lead to development of novel therapeutics.