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  • Copper(I) complex  (1)
  • Immunofluorescence  (1)
  • Key words: Mast cells — Fc receptors — TNF-α— Gene regulation — RBL  (1)
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  • 1
    ISSN: 1420-908X
    Schlagwort(e): Key words: Mast cells — Fc receptors — TNF-α— Gene regulation — RBL
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Objective: In the present study, we investigated signal transduction pathways involved in TNF-α gene expression and TNF-α secretion by mast cells stimulated through the high affinity IgE receptor (FcɛRI).¶Materials and Methods: TNF-α mRNA steady state levels and TNF-α secretion in the presence of specific pharmacological agents were monitored using rat basophilic leukemia cells (RBL-2H3) stimulated through FcɛRI. Relative amounts of TNF-α mRNA versus β-actin levels were quantified by RNase protection and RT-PCR assays. TNF-α secretion was measured by a current ELISA test.¶Results: We show that EGTA (5 mM) prevented TNF-α mRNA expression and TNF-α secretion in antigen-stimulated cells. The protein kinase C (PKC) inhibitor bisindolylmaleimide I substantially blocked TNF-α secretion at 2 μM but had only a marginal effect on TNF-α mRNA expression. The results were similar when PKC isoforms were depleted by long-term exposure to 100 nM phorbol ester (PMA). The PI 3-kinase inhibitor wortmannin blocked TNF-α secretion at low doses (EC50 = 13 nM), but only partially affected mRNA expression.¶Conclusions: Our results show that in FcɛRI-stimulated RBL-2H3 cells calcium mobilization, activation of PKC and PI 3-kinase are necessary for TNF-α secretion while for the increased TNF-α mRNA expression PKC activity is dispensable and PI 3-kinase activity only partially required.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-0878
    Schlagwort(e): Adenohypophysis, duck ; Gonadotrophes ; Immunofluorescence ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An indirect immunofluorescence technique and an anti-chicken LH serum were used to localize cells in the adenohypophyses of drakes at different stages of their breeding cycle, after castration, and after castration combined with thyroxine treatment. Immunofluorescent cells were distributed throughout both lobes of the adenohypophyses from control and experimental birds and were shown to be alcian blue positive, PAS negative, basophiles. Immunofluorescent cells were as numerous in castrated birds as in castrated birds treated with thyroxine. Adjacent thin and semi-thin sections were used to study the cells binding anti-LH serum at light microscope and ultrastructural levels. The cells contained spherical granules with variable densities and diameters ranging between 40 and 280 nm in the rostral (= cephalic) lobe, and between 60 and 260 nm in the caudal lobe. The light microscope and ultrastructural observations showed that the anti-LH serum binds to cells which have been classified by other authors in the Pekin duck, quail and pigeon as TSH producing delta cells. The experimental technique used did not permit a distinction to be made between cells producing FSH and LH.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 0044-2313
    Schlagwort(e): Copper(I) complex ; homoleptical copper(I) chalcogenolates ; synthesis ; crystal structures ; NMR spectra ; cryoscopic measurements ; electrochemistry ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Synthesis and Structure of Copper(I)Chalcogenolate-2,2′-Bipyridine Complexes [CuS(2,4,6-iPr3C6H2)]4(Bipy)2 and [CuSe(2,4,6-iPr3C6H2)]2(Bipy)2The oligomeric homoleptical copper(I) chalcogenolate compounds [CuS(2,4,6-iPr3C6H2)]x=4,8 and [CuSe(2,4,6-iPr3C6H2)]6 react with 2,2′-bipyridine (Bipy) to yield the tetranuclear complex [CuS(2,4,6-iPr3C6H2)]4(Bipy)2 (4) and the dinuclear complex [CuSe(2,4,6-iPr3C6H2)]2(Bipy)2 (5). The structures of 4 and 5 were determined by X-ray analysis. In the eight-membered Cu4S4 core of 4 with chair conformation the copper atoms are linked by μ2-bridging selenolate ligands. Only two copper atoms are coordinated by 2,2′bipyridine. The corresponding copper(I) selenolate complex (5) forms a folded four-membered Cu2Se2 ring with μ2-bridging selenolate ligands. The Cu—Cu distance of 2.52 Å is relatively short. In contrast to the reaction performed with 2,2′-bipyridine, addition of phenantroline to 1 respectively 2 yields a dinuclear complex [CuS(2,4,6-iPr3C6H2)]2(Phen)2 (10). NMR spectroskopic and cryoscopic measurement of 4 show that this complex dissociates into smaller fragments in solution which undergo rapid exchange reactions. However, corresponding investigations performed on 5 indicate that the solid state structure is maintained in solution. The electrochemical behaviour of 4, 5 and 10 was studied in CH2Cl2 and in any case no reversible redox processes could be observed.
    Notizen: Die oligomeren homoleptischen Kupfer(I)-chalkogenolat-Verbindungen [CuS(2,4,6-iPr3C6H2)]x=4,8 (1, 2) und [CuSe(2,4,6-iPr3C6H2)]6 (3) wurden mit 2,2′-Bipyridin (Bipy) zu dem tetranuklearen Kupferkomplex [CuS(2,4,6-iPr3C6H2)]4(Bipy)2 (4) und dem dinuklearen Komplex [CuSe(2,4,6-iPr3C6H2)]2(Bipy)2 (5) umgesetzt, deren Strukturen durch Einkristall-Röntgenstrukturanalysen bestimmt wurden. In dem achtgliedrigen Cu4S4-Ring von 4 mit Sesselkonformation sind die Kupferatome über μ2-verbrückende Thiolat-Liganden verknüpft, wobei nur 2 Kupferatome von 2,2′-Bipyridin koordiniert werden. Der entsprechende Kupfer(I)-selenolat-Komplex (5) bildet einen gefalteten viergliedrigen Cu2Se2-Ring mit μ2-verbrückenden Selenolat-Liganden. Der Cu—Cu-Abstand ist mit 2.52 Å relativ kurz. Im Gegensatz zu der Umsetzung mit 2,2′-Bipyridin entsteht aus 1 bzw. 2 und Phenantrolin (Phen) ein dinuklearer Komplex [CuS(2,4,6-iPr3C6H2)] 2(Phen)2 (10). Während 5 sich offensichtlich ohne Zerfall löst, wie NMR-spektroskopische und kryoskopische Untersuchungen zeigen, dissoziiert 4 in Lösung in kleinere Aggregate, die miteinander im Gleichgewicht stehen. Das elektrochemische Verhalten von 4, 5 und 10 wurde in CH2Cl2 studiert. In allen Fällen wurden keine reversiblen Redoxprozesse beobachtet.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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