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1.
Summary The defensive secretion of the opilionidPhalangium opilio contains 1,4-naphthoquinone and 6-methyl-1,4-naphthoquinone. Naphthoquinones are of rate occurrence in arthropods, having previously been reported only from certain tenebrionid beetles.Paper No. 60 of the series: Defense Mechanisms of Arthropods.Acknowledgments. Partial support by the National Institutes of Health (grant Nos. AI-12020 and AI-02908, and fellowship award CA 05646 to D.F.W.) and the National Science Foundation (grant No. BMS 74-15084) is gratefully acknowledged. We thank Dr W.A. Shear for identifying the opilionid, and S. Daniels, K. Dodge, M. Guzewich and C. Smith for helping collect the specimens..  相似文献   

2.
Summary The defensive secretions of 4 species of opilionids were analyzed.Leiobunum ventricosum andHadrobunus maculosus produce 4-methylheptan-3-one, whileL. calcar produces E-4,6-dimethyl-6-octen-3-one.L. longipes produces E-4,6-dimethyl-6-nonen-3-one, a new natural product.Paper No. 51 of the seriesDefensive Mechanisms of Arthropods.Acknowledgments. Partial support by the National Institutes of Health (Grant Nos. AI-12020 and AI-02908 and Fellowship No. 1-F32-CA05139 to T.H.J.) and the National Science Foundation (Grant No. BMS 75-15084) is gratefully acknowledged. We thank Dr.W. A. Shear for identifying the opilionids.  相似文献   

3.
Summary Temperature treatment of sera of erythrocyte immunized adults of 3 amphibian species has shown that cooling enhances antigen-antibody complexing and does not alter complement function in vitro. These findings bear on understanding in vivo temperature immunosuppression in poikilotherms.This research was partially supported by a grant No. AI-12846 from the National Institutes of Health, Bethesda, Md, USA. The authors are grateful for the technical assistance of Ms J. S. Ruben.  相似文献   

4.
Zusammenfassung Es wurde die Wirkung von künstlichen, bilateralen, elektrolytisch gesetzten Läsionen in verschiedenen Bezirken des Hypothalamus auf die Bildung von Erythropoietin untersucht: Jugendliche (entwöhnte) Ratten reagieren nicht gleich wie erwachsene Ratten, und die verschiedenen Kerne des Hypothalamus beeinflussen die Erythropoietin-Bildung verschieden.

This investigation was supported in part by research grants No. AI-04506, CA-02728 and CA-07745 from the U.S. Public Health Service, National Institutes of Health, the John A. Hartford Foundation, Inc. and U.S. Public Health Service Grant No. HE-06975 from the National Heart Institute.  相似文献   

5.
Summary 4-Isothiocyanato-4-nitrodiphenylamine possessed anthelmintic activity againstNippostrongylus dubius andHymenolepis nana in mice andH. diminuta in rats as determined by both egg counts and recovery of parasites at autopsy. No activity was detected against the cestode,Spirometra mansonoides, in cats.This investigation was supported in part by grants AI-10512 and AI-09483 from the National Institutes of Health. The authors are indebted to Dr P.P. Weinstein for providing animals infected withSpirometra mansonoides.  相似文献   

6.
Summary Pyrrolizidine alkaloid sequestered by adult maleDanaus gilippus from plants is transferred in large measure to the female at mating, and by the female to the eggs. The eggs, presumably, are protected as a result. The male's courtship pheromone, danaidone, derived from the sequestered alkaloid, may function to advertise the male's alkaloid-donating capacity.Acknowledgments. Paper Nr. 89 of the series Defense Mechanisms of Arthropods. Study supported by NIH (Grants AI-02908 and AI-12020; Predoctoral Traineeship to DED), Hatch funds (191-7416), the Bache Fund (National Academy of Sciences, to DED), and the Theodore Roosevelt Memorial Fund (American Museum of Natural History, to DED). We thank M. Weingarner and J. Miller forD. gilippus collection, J. Boggan for technical assistance, and the staff of the Archbold Biological Station, Lake Placid, Florida, for assistance and hospitality. One of us (DED) is indebted to M. D. Achey, who by demonstrating nuptial cardenolide transfer in the monarch butterfly [Honors Thesis, Amherst College, Amherst, Massachusetts (1979)] raised the possibility that other plant metabolites might be similarly transferred in danaines.Deceased July, 1985. This paper is affectionately dedicated to his memory.  相似文献   

7.
Summary A computer search, made for distant relationships between lysozyme Ch, hen egg white lysozyme, and bacteriophage T4 lysozyme, revealed no unusual similarities in their amino acid sequences. Also, antibodies generated against lysozyme Ch failed to cross react with hen egg white lysozyme and vice versa. These lysozymes most likely represent examples of convergent evolution.Acknowledgments. This research was supported by Public Health Service Grant AI-15531 and the Biomedical Research Support Grant RR-05424.To whom all communication should be addressed.  相似文献   

8.
Summary A hexadecapeptide corresponding to positions 59–74 of ubiquitin was synthesized and purified. The peptide was characterized by its mobility in TLC and electrophoresis, amino acid sequence and composition, and molar rotation. The peptide possessed approximately 40% activity compared with native ubiquitin in each of 3 biological assays in vitro: a) thymocyte induction, b) B cell induction and c) elevation of intracellular cyclic AMP levels in sarcoma 180 cells.Acknowledgments. We thank Dr Geoffrey Tregear for helpful suggestions for the synthesis strategy, Dr Jim Burton for guidance with the methods for establishing peptide purity, and Ronald King, Miriam Miller, Jeanette Dilley and Linda Townley for excellent technical assistance. This work was supported by U.S. Public Health Service Grants CA-08748, CA-16889, CA-08415, CA-17085 and AI-12487, and by NCI Contract CB-53868.  相似文献   

9.
Summary The blood of the Mexican bean beetle (Epilachna varivestis) contains a homotropane alkaloid, euphococcinine (1). The beetles reflex bleed when disturbed, thereby deploying the alkaloid, which is provenly deterrent to spiders and ants. Newly emerged adults lack the alkaloid, but the compound builds up to deterrent levels in their blood within days. Eggs and larvae ofEpilachna are devoid of the compound.Paper No 79 of the series: Defense Mechanisms of Arthropods. Study supported by NIH (Grants AI-02908 and AI-12020) and Hatch Funds (NYC-191409). We thank G. Eidens, K. Hicks, and M. Eisner for excellent technical help, and an anonymous reviewer for calling two critical references to our attention. The ant tests were done at the Archbold Biological Station, Lake Placid, Florida. The hospitality of the Fogarty Scholar-in-Residence Program (to J.M.) is acknowledged with pleasure.  相似文献   

10.
Summary A procedure to enhance the schistosomicidal effectiveness in vivo of an isothiocyanate derivative and some of its antischistosomal properties are reported. Determinations of the effects of this compound on tissue thiol levels and on highly sensitive bacterial tester strains have indicated that its mutagenic potential is of a low order and that the latter is decreased further after reduction of the host's intestinal bacterial flora.Acknowledgments. Supported, in part, by grants No. AI-08022 and No. GM-16492 from the National Institutes of Health, and No. 274-0063 (JHU No. 1) from The Edna McConnell Clark Foundation. We wish to express our sincere appreciation to Dr.H. Striebel and Dr.F. Kradolfer of Ciba-Geigy for providing us with the isothiocyanate derivative and with information about its biological activities, and to Dr.H. van der Schalie and to Dr.H. Blankespoor of the Museum of Zoology, University of Michigan, for supplying us with mice infected with 3 strains ofS. japonicum (under contract No. N01-AI-42504, NIH).  相似文献   

11.
Crude acetic acid extract of Rat ovaries pretreated with pregnant mare serum (PMSG) contains native peptides with two types of separable biological activities: one, molecular weight greater than 10,000 dalton inhibits the secretion of both LH and FSH as stimulated by luteinizing hormone releasing factor (LRF) in a pituitary monolayer culture system and is referred to as gonadostatin; the other, less than 3,500 dalton, stimulates the secretion of gonadotropins and is designated as gonadocrinin. The biological activities of ovarian gonadocrinin can be competitively inhibited by an LRF-analog-antagonist, D-Phe2, D-Trp6-LRF. These ovarian peptides may participate in physiological control of pituitary LH/FSH secretion.  相似文献   

12.
Summary In the first part of this review the biogenesis of methyl-branched bacterial lipids through incorporation of the methyl group of methionin or of propionic acid is studied; it is shown that in the biogenesis of tuberculostearic acid, only two hydrogen atoms are transferred with the carbon of methionin. The same observation is made in the second part, concerning the origin of the 24-methyl group of ergosterol. Different mechanisms of C-methylation by methionin are discussed. It is also shown that the ethylidene group of fucosterol is formed by a double transfer of the methyl carbon of methionin.In the third part the possible biological function of the 2-methyl group of vitamin K and the ubiquinones is studied; the acid catalysed isomerisation of these compounds to very reactive methylene-quinone-chromanes is discussed in detail.

SechstePaul-Karrer-Vorlesung, gehalten am I. Juli 1964 an der Universität Zürich; ein ähnlicher, englischer Text wird als «Second Jubilee Lecture» der Biochemical Society im Biochemical Journal, im Druck (1964), erscheinen. — Unsere Arbeiten wurden durch Grant AI-02838 vom National Institute of Health (U.S. Public Health Service) und durch Unterstützungen des Commissariat à l'Energie Atomique, Saclay, gefördert.  相似文献   

13.
Summary Xanthobilirubic acid (XBR) undergoes enzymatic oxidation in the presence of horseradish peroxidase and tertbutyl hydroperoxide to give cleanly methylethylmaleimide (1) and 5-formyl-2,4-dimethyl-1H-pyrrole-3-propanoic acid (2).The authors wish to thank the National Science Foundation (NSF CHE 79-10133) and the National Institute of Child Health (HD 09026) for generous support of this work.  相似文献   

14.
Summary Corticosteroid induction of mouse hepatic phosphoenolpyruvate carboxykinase was inhibited by prior injection of poly IC. Mice challenged with a lethal dose of endotoxin 4 h after administration of poly IC could not be protected by a concurrent injection of hydrocortisone.This investigation was supported by U. S. Public Health Service research grant No. AI-10087 from the National Institute of Allergy and Infectious Diseases.  相似文献   

15.
Résumé Les phospholipides en état de lipoprotéine sont hydrolysés à un rythme plus accéléré par la phospholipase D des chloroplastes que ne le sont les phospholipides purifiécs. La remarquable affinité de l'enzyme pour les soustrats en forme lipoprotéique se manifeste en l'absence de l'éthère éthylique qui est l'activateur indispensable à l'hydrolyse des phospholipides purifiées.

This work was supported by a research grant (AI-03171) from the U.S. National Institutes of Health.  相似文献   

16.
Summary Vinblastine did not affect the basal secretion of enzymes from the rat pancreas, but it potentiates the secretory response to dibutyryl cyclic AMP. This potentiation is confirmed by the observation of numerous pictures of exocytosis at the apical part of the acinar cell. Dibutyryl cyclic GMP by itself, or associated with vinblastine, failed to modify the spontaneous release of enzymes or the secretion induced by dibutyryl cyclic AMP.This work was supported by the Institut National de la Santé et de la Recherche Médicale (France).  相似文献   

17.
Summary Volatile mutagens derived from sodium nitrite buffered at various pH values or in the presence of human feces were detected using AmesSalmonella tester strain TA 1535 on petrie plates inverted over samples. Volatile mutagenicity increased as the pH decreased and was primarily a function of the nitrous acid produced from sodium nitrite and hydrogen ions. Sodium nitrite administered intracecally to 3 Wistar rats through surgically implanted cannula caused tumors (fibrosarcoma: 1/3 and squamous cell, 2/3). The possible role of nitrite-derived mutagens in GI cancer is discussed.The authors are grateful to Dr A. Carl MacDonald of the Dept. of Surgery, Dalhousie University for his advice and encouragement in this project.This work was supported by the National Cancer Institute of Canada.  相似文献   

18.
Summary Fluid-phase pinocytosis kinetics and lysosomal enzyme secretion parameters were measured inDictyostelium discoideum amoebae constructed from strain AX3 by transformation with a multicopy plasmid carrying either a normalras gene (ras-Gly12), a mutatedras gene (ras-Thr12) or by the vector carrying the geneticin resistance gene only (pDNEO2). It was found that the pinocytosis rate and extent as well as the lysosomal enzyme secretion were slightly different in the three strains. These changes, however, were related to minor modifications of the cellular volumes. The overall concentration of inositol hexakisphosphate was similar in the three strains.This work was supported in part by a grant from the Ligue Nationale Française contre le Cancer (no 880258) to MS, and by a grant from the Fonds National Suisse de la Recherche Scientifique (No. 3.623-087) to CR.  相似文献   

19.
Summary Retinoic acid caused a decrease in adhesiveness but no growth change in the allotransplantable TA3-Ha cell and no change in adhesiveness or growth in the strain specific TA3-St cell. The retinoic acid binding protein was detected in the TA3-Ha, but not the TA3-St, cell.This study was supported in pat by Public Health Service Grants CA-08418 and CA-18600 from the National Cancer Institute, National Institutes of Health. This is publication 955 of the Robert W. Lovett Group for the Study of Diseases Causing Deformities. We gratefully acknowledge the contributions of Drs Luigi M. De Luca and Anton M. Jetten of the Laboratory of Cellular Carcinogenesis and Tumor Promotion, National Cancer Institute, National Institutes of Health, Bethesda, MD, without whose help this study would not have been possible.  相似文献   

20.
Summary The addition of dopamine to anterior pituitary incubations resulted in a marked decrease (88% for3H prolactin and 69% for RIA prolactin) in prolactin release. Incubation with the cholinergic agonists carbacol, arecoline and nicotine resulted in no significant change in prolactin secretion.Supported in part by NSF Research grant No. BMS 74-17332.The authors appreciate receiving as a gift from the National Institute of Arthritis, Metabolic and Digestive Diseases, the rat prolactin used for iodination (RP-I2) and standards (RP-1).  相似文献   

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