Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Analytical Chemistry and Spectroscopy  (12)
  • Life and Medical Sciences  (12)
  • Homoptera  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 16 (1990), S. 1899-1909 
    ISSN: 1573-1561
    Keywords: Castanospermum australe ; Moreton Bay chestnut ; Senecio vulgaris ; groundsel ; Pseudococcus longispinus ; mealybug ; aphid ; Schizaphis graminum ; greenbug ; Myzus persicae ; green peach aphid ; Aphis nerii ; oleander aphid ; Homoptera ; Aphididae ; Coccidae ; phloem transport ; honeydew ; indolizidine ; pyrrolizidine alkaloid ; gramine ; DIMBOA ; cardenolide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Analysis of honeydew excreted by various sap-sucking insects indicated the presence of certain plant secondary constituents in the phloem of their host plants. Honeydew excreted by mealybugs (Pseudococcus longispinus), living onCastanospermum australe, contained the indolizidine alkaloid castanospermine, a potent β-glucosidase inhibitor. Similarly, honeydew from green peach aphids (Myzus persicae), feeding onSenecio vulgaris flower buds, contained the pyrrolizidine alkaloid senecionine, itsN-oxide, and hydrolytic products including retronecine. Cardenolides were detected in the honeydew of oleander aphids (Aphis nerii) feeding on oleander (Nerium oleander), indicating that these compounds are translocated in the phloem. On the other hand, honeydew from greenbugs (Schizaphis graminum), feeding on barley, lacked gramine or related indole metabolites. Similarly MBOA, the breakdown product of DIMBOA, was not detected in the honeydew of greenbugs living on DIMBOA-containing wheat.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-1561
    Keywords: Feeding deterrents ; Acyrthosiphon pisum ; Homoptera ; Aphi-didae ; host-plant resistance ; pyrrolizidine ; indolizidine ; quinolizidine ; alkaloids ; locoweed ; honeydew ; Astragalus lentiginosus ; phloem transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The feeding deterrency of a series of pyrrolizidine, indolizidine, and quinolizidine alkaloids and selected derivatives was measured against the pea aphid (Acyrthosiphon pisum Harris). The indolizidine alkaloid, castanospermine, was intensely active (ED50, 20 ppm) as were the quinolizidine alkaloids, but only modest feeding deterrency was observed with most of the pyrrolizidine alkaloids tested. The insect survival rate of aphids on a castanospermine-supplemented diet over 24 hr was also very low relative to the controls. Castanospermine does not inhibit aphid trehalase. The indolizidine alkaloid swainsonine occurred in the honeydew of pea aphid feeding on the locoweed,Astragalus lentiginosus. Since the pea aphid is a phloem feeder, swainsonine must be transported in the phloem.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cytodifferentiation during spermiogenesis in Hydra littoralis was studied at the fine structural level. Concentration of nuclear material as well as specific orientation of granular and filamentous nuclear elements are apparent in two regions of the early spermatid: where the nuclear envelope is in contact with mitochondrial membranes at one pole of the cell and at an opposite region where the nucleus is closely apposed to the plasma membrane. Ultimately the mass of condensed nuclear material becomes concentrated at the mitochondrial pole of the cell. Additional electron-dense material is extruded from the nucleus into a large vacuole which is in continuity with the nuclear membrane as well as associated with Golgi lamellae and vesicles. Eventually all residual cytoplasm is sloughed, leaving the nucleus, mitochondria, and flagellum. These observations are suggestive of nucleocytoplasmic interactions during development, especially influences of mitochondria and plasma membranes on chromatin condensation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 13 (1987), S. 1759-1770 
    ISSN: 1573-1561
    Keywords: Castanospermine ; 6-epicastanospermine ; deoxynojirimycin ; cellobiase ; lactase ; maltase ; sucrase ; trehalase ; endosymbiote ; insect-plant interactions ; allelochemicals ; Homoptera ; Coleoptera ; Lepidoptera ; Diptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The indolizidine alkaloid, castanospermine (1,6,7,8-tetrahydroxy-octahydroindolizidine—a stereochemical mimic of glucose found in the Australian legumeCastanospermum australe), differentially inhibited cellobiose, lactose, maltose, sucrose, and trehalose hydrolyzing enzymes from a broad taxonomic spectrum of insects (19 species from 12 different families). It was a potent inhibitor of cellobiase activity of all insects tested (50% inhibition at 〈3.2 × 10−5 M castanospermine). With one exception, it also inhibited lactase activity of all insects examined. Only in the sap-feeding Homoptera did castanospermine inhibit all disaccharidase activities assayed. Trehalase activity of the Lepidoptera and Diptera was generally inhibited by castanospermine, whereas inhibition of trehalase activity of the Coleoptera by castanospermine was exiguous or not detectable. Castanospermine was a significant feeding deterrent towards pea aphids,Acyrthosiphon pisum, with an ED50 of 1 × 10−4 M in artificial diets. Two compounds stereochemically related to castanospermine, deoxynojirimycin and 6-epicastanospermine, were each slightly active at deterring the feeding of green peach aphids,Myzus persicae, (ED50=2.5 × 10−3 M) and greenbugs,Schizaphis graminum (ED50=5 × 10−3 M), respectively. Among the insects studied there was no distinct relationship between enzyme inhibition and adaptation to host plants containing castanospermine or other toxic alkaloids.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 24 (1984), S. 297-306 
    ISSN: 0730-2312
    Keywords: Plasmodium knowlesi ; variant antigen ; schizont-infected erythrocyte ; detergents ; radioiodination ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Four detergents have been compared for identification of the Plasmodium knowlesi variant antigen on infected erythrocytes by immunoprecipitation analysis. Erythrocytes infected with late trophozoite and schizont forms of cloned asexual parasites were labeled by lactoperoxidase-catalyzed radioiodination and extracted either with the anionic detergents sodium dodecyl sulfate (SDS) or cholate, the neutral detergent Triton X-100, or the zwitterion 3-[(3-cholamidopropyl)di-methylammonio]-1-propane sulfonate (CHAPS). After addition of Triton X-100 to SDS and cholate extracts, parallel immunoprecipitations of the four extracts were performed using rhesus monkey antisera of defined agglutinability. Identical results were obtained with clone Pkl(A+ ), which has 125I-variant antigens of Mr 210,000 and 190,000, and with clone Pkl(B+)l+, which hasvariant antigens of Mr 200,000-205,000. SDS yielded maximal levels of immunoprecipitated 125I-variant antigens. Variant-specific immunoprecipitation was detected in some experiments with Triton X-100 and cholic acid but with significantly lower recovery than with SDS. CHAPS extraction did not yield the variant antigens on immunoprecipitation. The variant antigens could also be identified in Triton X-100-insoluble material by subsequent extraction with SDS, indicating that failure to recover these proteins in the Triton X-100-soluble fraction is due to failure of this detergent to extract the variant antigens rather than to degradation during extraction. We suggest that the 125I-variant antigens either have a structure that renders them intrinsically insoluble in Triton X-100, cholate, or CHAPS, or that they are associated in some way with host cell membrane components that also resist solubilization by these detergents.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Fine structural localization of enzymes hydrolyzing nucleoside phosphates in the rat adrenal cortex has been determined, and the selective inhibition of those enzymes exhibiting intracellular localization has been effected. Glutaraldehyde-fixed adrenocortical tissue was incubated in a medium which contained a nucleoside mono-, di- or triphosphate of adenosine, inosine, guanosine, or cytidine as substrate. Intracellular enzymatic activity was exhibited when one of three nucleoside phosphate substrates was employed. When IDP was used, final product of enzymatic activity was found on membranes of the endoplasmic reticulum, Golgi cisternae and intramitochondrial microvesicles. Final product was localized on the membranes of the endoplasmic reticulum and certain mitochondria when ITP was used. With GTP as substrate, activity was primarily localized on mitochondrial microvesicles and agranular endoplasmic reticulum, with no Golgi involvement noted.The phosphatases for which intracellular localization was determined exhibited four different sites of activity: (a) agranular endoplasmic reticulum, (b) microvesicles within mitochondria, (c) nuclear membrane, and (d) subendothelial and/or intercellular spaces with occasional involvement of the plasma membrane. When nicotinamide was added to the incubation media, intracellular phosphatase activity was inhibited. Extracellular enzymatic activity was unaffected by nicotinamide. The possible mode of action of nicotinamide in enhancing steroidogenesis and inhibiting intracellular phosphatase activity is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Chick embryos were inoculated with influenza-A virus over the blastoderm at 42-50 hours incubation (37°C). Surviving embryos were harvested 24 hours later, Grossly and microscopically, the developing brain exhibits a type of abnormality in which the neural wall is highly convoluted with folds projecting into the ventricular cavities, suggesting “overgrowth” of the neural tissue.A comparison of measurements on projection drawings of serial sections of virus inoculated and control embryos at comparable developmental stages indicates that the ventricular surface area, volume of brain tissue and volume of the ventricular cavity are markedly less in the experimental embryos, but average thickness of the brain wall is greater. There are fewer nuclei and mitotic figures in experimental embryos, although average nuclear and mitotic densities and mitotic index are approximately the same as control values.It is evident that the characteristic neural defect is not due to excessive growth, since the volume of brain tissue and number of cells are consistently less in experimental embryos. It is concluded that the virus infection results in an inhibition of growth of the brain wall, and that the increased thickness and foldings must result from collapse of the brain which in turn may be due to a decrease in the amount of ventricular fluid.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Twelve weeks after bilateral superior cervical ganglionectomy, the number of pineal concretions in adult male gerbils was drastically decreased irrespective of photoperiodic treatment. These findings present further evidence that pineal concretions may be related to the metabolic activity of the gland. It is suggested that the pineal concretions of the gerbil are associated, in a yet unknown way, to the metabolism of the gland and that an active pineal is essential to maintain the large number of concretions seen in the normal state.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Globules or particles of material, 50 Å to 1000 Å in diameter, stained with Pb++ to become dense, occurred between, on, or within the microvilli of the absorptive cells of the proximal jejunum of rats which had been fasted for 48 hours and fed corn oil one hour before sacrifice. This material was demonstrable in tissues fixed in glutaraldehyde, osmium tetroxide, or both fixatives providing Pb++ staining occurred. No or very little stainable material was present in fasted rats. These findings were correlated with in vitro studies on negatively stained or Pb++ stained solutions of micelles. The absorption of particulate lipid by the microvilli of the epithelial cells of the small intestine is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...