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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 128 (1972), S. 100-114 
    ISSN: 1432-0878
    Keywords: Connective tissue ; Gastropoda ; Globular cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Blasenzellen stellen ein typisches Zellelement im Bindegewebe der Gastropoden dar. Licht- und elektronenmikroskopische Untersuchungen an Cepaea nemoralis haben gezeigt, daß der größte Teil einer Blasenzelle mit einer veränderlichen Glykogenmenge angefüllt ist. Diese zentrale Glykogenansammlung verdrängt das Zytoplasma mit seinen Organellen auf den peripheren Bereich der Zelle einschließlich der Zellausläufer und einen schmalen Saum um den Zellkern. Das wichtigste Identifizierungs-merkmal der Blasenzelle ist eine sehr spezialisierte — hier als Spaltenapparat bezeichnete — Oberflächendifferenzierung. Die Auswertung von Serienschnitten hat gezeigt, daß diese Oberflächenstruktur durch eine zum Teil verzweigte Invagination des extrazellulären Raumes gebildet wird, die wiederum von der Blasenzelle durch eine mäanderförmig unterbrochene Platte abgedeckt ist. Zwischen dem Spaltenapparat der Blasenzellen und dem Reusenapparat der Podozyten der Niere scheint eine Ähnlichkeit zu bestehen.
    Notes: Summary The globular cells are typical elements of the connective tissue of Gastropods. Light- and electronmicroscopic investigations of Cepaea nemoralis have shown, that these cells are filled with variable contents of glycogen, accumulated in the centre of the cell. This crowds the cytoplasm and the cell organelles into the peripheral area, including the cell processes and a narrow band surrounding the nucleus. The typical element of the globular cell is a special differentiation of the cell surface, the so-called “Spaltenapparat”. The three-dimensional organisation of the “Spaltenapparat” has been analysed by serial ultrathin sections. The reconstruction shows, that the “Spaltenapparat” consists of numerous branched invaginations of the extracellular space covered by very small, winding cell processes; there are tiny clefts between them. There appears to be some similarity between the “Spaltenapparat” of the globular cells and the pedicels of the podocytes of the renal glomerulus.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 130 (1972), S. 262-278 
    ISSN: 1432-0878
    Keywords: Connective tissue ; Gastropoda ; Globular cells ; Uptake of ferritin ; Endocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Experimentelle Untersuchungen am Schlundringbindegewebe von Cepaea nemoralis haben ergeben, daß — abgesehen von einigen Blutzellen—allein die Blasenzellen befähigt sind, injiziertes Ferritin aufzunehmen. Diese Substanz gelangt aus der Hämolymphe der Körperhöhle über das Gefäßsystem durch das Endothel der Kapillaren in die interzellulären Räume des Bindegewebes und von dort ausschließlich zu den Blasenzellen. Elektronenmikroskopisch zeigt sich, daß die Blasenzellen das Ferritin wahrscheinlich nur durch Endozytose im Bereich des Spaltenapparates aufnehmen. Das Ferritin wird nicht von der Zelle abgebaut, sondern auf engstem Raum, zum Teil in parakristalliner Anordnung, in Endosomen gespeichert. Die Fähigkeit der Blasenzellen, Fremdstoffe selektiv aufzunehmen, läßt vermuten, daß sie eine analoge Bedeutung für die Gastropoden haben wie die Pericardialzellen für Insekten oder das Retikuloendotheliale System für die Vertebraten.
    Notes: Summary Experimental investigations of the ganglionic connective tissue sheath of Cepaea nemoralis have shown, that — except for some blood cells — only the globular cells are capable for the uptake of injected Ferritin. This substance gets out of the hemolymph of the body cavity through the blood-vessels and capillaries, across the collagenous connective tissue into the cytoplasm of the globular cells. The globular cells take up the Ferritin by endocytosis, exclusively by the invagination of the „Spaltenapparat“. The Ferritin remaines accumulated in endosomes sometimes having a paracrystalline pattern. Because of their capability to incorporate and accumulate injected substances, the globular cells have been compared with the pericardial cells of insects respectively with the reticuloendothelial system of vertebrates.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0878
    Keywords: Connective Tissue ; Gastropoda ; Uptake of Ferritin and Trypan Blue ; Light- and Electron-Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Untersuchungen des Bindegewebes der stylommatophoren Pulmonaten Helix pomatia and Cepaea nemoralis zeigen, daß die Blasenzellen des Bindegewebes befähigt sind, Substanzen aus der Hämolymphe aufzunehmen. Licht- und elektronenmikroskopische Untersuchungen ausgewählter Bindegewebsbereiche, die in bestimmten Zeitintervallen nach der Injektion von Trypanblau oder Ferritin in die Körperhöhle präpariert wurden (Stufenuntersuchungen), ergaben, daß — mit Ausnahme einiger Blutzellen — ausschließlich die Blasenzellen die injizierten Substanzen aufgenommen hatten. Weder andere Bindegewebszellen noch die Zellen von Organen (u.a. Gonaden, Schlundringganglien), die von Bindegewebe umgeben werden, enthielten diese Substanzen oder hatten sie akkumuliert. Die elektronenmikroskopischen Aufnahmen zeigen, daß die Aufnahme von Ferritin in die Blasenzellen wahrscheinlich durch Pinocytose erfolgt.
    Notes: Summary Investigations of the connective tissue of the stylommatophoran pulmonates Helix pomatia and Cepaea nemoralis have demonstrated, that so-called “globular cells” have the capability for the uptake of substances out of the hemolymph. Light- and electron-microscopic investigations of pieces of connective tissues fixed at different intervals after the injection of Trypane Blue or Ferritin into the cavity of the body give striking evidence for the uptake of these substances exclusively into the globular cells (with the exception of some blood cells). Neither other connective tissue cells nor cells of the organs (e.g. gonads, central nervous ganglions) surrounded by connective tissue incorporate or accumulate the injected substances. The uptake of Ferritin into the cytoplasm of the “globular cells”, normally filled with a high amount of glycogen, takes place by pinocytosis.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 137 (1973), S. 281-292 
    ISSN: 1432-0878
    Keywords: Amoebocytes, globular cells ; Connective tissue ; Gastropoda ; Endocytosis ; Selective uptake of foreign particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Amoebozyten und Blasenzellen im Bindegewebe von Cepaea nemoralis zeigen deutliche Unterschiede in ihrer Endozytosefähigkeit. Grobe Partikeln wie Latexkugeln und Erythrozyten werden von den Amoebozyten endozytiert. Kleine Moleküle wie Ferritin und Hämoglobin werden hauptsächlich in den Blasenzellen akkumuliert, können aber auch von Amoebozyten aufgenommen werden. Dasselbe Endozytoseverhalten ist bei beiden Zellen zu beobachten, wenn Latex und Ferritin nacheinander in bestimmtem Zeitabstand angeboten werden. Die unterschiedliche Affinität der Amoebozyten und Blasenzellen zu den injizierten Fremdstoffen kann einmal durch ihre morphologische Oberflächendifferenzierung bedingt sein, zum anderen könnte ein funktionelles Zusammenwirken der Zellen im Sinne einer Arbeitsteilung vorliegen.
    Notes: Summary Amoebocytes and globular cells in the connective tissue of Cepaea nemoralis vary in the endocytotic incorporation of foreign materials of different size. Only the amoebocytes take up the latex beads and the red blood cells. However most of the injected ferritin and hemoglobin is ingested by the globular cells; a limited endocytotic capacity has been observed for these molecules by the amoebocytes. The results are the same, even though latex beads and ferritin are injected successively in definite intervals. Therefore the different affinity of amoebocytes and globular cells to foreign particles can not depend only on the morphological differentiation of their cell surfaces.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 74 (1991), S. 1213-1220 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of methyl 2-(1-hydroxyalkyl)prop-2-enoates 1 with conc. HBr solution afforded methyl (Z)-2-(bromomethyl)alk-2-enoates 2, which were transformed regioselectively into N-substituted methyl (E)-2- (aminomethyl)alk-2-enoates 3 (SN2 reaction) and into N-substituted methyl 2-(1-aminoalkyl)prop-2-enoates 4(SN2′ reaction). Regiocontrol of nucleophilic attack by amine was accomplished simply by choice of solvent, the SN2 reaction occurring in MeCN and the SN2′ reaction in petroleum ether. Hydrolysis and lactamization afforded β-lactams 7 and 8, containing an exocyciic alkylidene and methylidene group at C(3), respectively.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 327 (1985), S. 51-62 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Aminoketones. VIII. Diastereoselective Synthesis of 3-Hydroxy-prolinesGlycine esters react in two steps (aminoalkylation and N-acylation) to N-acyl-N-(β-benzoylethyl)-glycine ester 3. In less polar solvents these ketonic compounds are n,π*-excited by 300 nm irradiation. In ether 3* yield mixtures of aminocyclopropanoles 4, hydroxyprolines 5 and products of additions and cleavages. In benzene and cyclohexane/benzene, respectively, the regioselective photocyclization to 5 is favoured. Furthermore this hydroxyproline synthesis has the advantages of high diastereoselectivity yielding the (2,3) E-5 and of high overall-yields in connection with the one pot method. The influence of solvents and substituents on the regio- and diastereoselectivity are explained using a model with stabilization of special conformations of intermediates by dipol-dipol interactions.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0947-3440
    Keywords: Cyclopropyl homoconjugation ; Molecular structures ; Electron density determinations ; Ab initio calculations ; Spiro compounds ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low-temperature crystal structural studies of a series of saturated and unsaturated bicyclo[2.2.1]heptadiene, heptene and heptane compounds with 7-spirocyclopropyl substitution reveal significant differences in the bond lengths of the three-membered rings and in the C—C single bonds of the bicyclic fragment. A complex interplay of strain and different types of conjugation influence the molecular structure of the bicycloheptadiene derivative 1, where the difference in the length of the three-membered ring bonds is 0.040 Å and all C—C single bonds in the bicyclic fragment are lengthened significantly. Ab initio calculations at the HF/6-31G(d) (to a minor extent) and MP2/6-31G(d) levels are in good agreement with the experimental data. Calculated charge distributions and dipole moments further support the relevance of cyclopropyl homoconjugation in the investigated prototype of Walsh and through-space π-orbital interaction. Static difference electron density maps have been derived from the experimental data by multipole refinements which showed exocyclic shifts of electron density in the planes of the three-membered rings and significant bond ellipticities at the C—C single bonds in the unsaturated bicyclic units.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 124 (1930), S. 133-143 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 129 (1931), S. 163-177 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 314 (1901), S. 200-230 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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