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  • 1
    ISSN: 1420-908X
    Keywords: Key words: Mast cells — Fc receptors — TNF-α— Gene regulation — RBL
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: In analysing coupled electromagnetic thermal behaviours in electrical devices one of the main difficulties is related to the uncertainties of thermal parameters. The authors present, in this work, a technique using the method of experimental designs for the identification of thermal parameters necessary for a coupled finite element model analysing the magneto-thermal behaviour of an electromagnetic device.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Bradford : Emerald
    Compel 17 (1998), S. 181-185 
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: Stochastic methods offer a certain robustness quality to optimization process. In this paper, the genetic algorithm, based on the computer simulation of the natural evolution, is used for the shape optimization of an electromagnetic actuator. The framework is modeled by a 2D finite element method allowing the computation of the magnetic force. The aim is to obtain a desired force profile considering the armature movement.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Epidemiologic and in vitro data have shown that the association of housedust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection on immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts: molecular weights of snail allergens ranged from 〈21 to 200 kDa. Marked individual differences were observed in the seven sera under study: most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin. Diseases, Environment.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0044-2313
    Keywords: Copper(I) complex ; homoleptical copper(I) chalcogenolates ; synthesis ; crystal structures ; NMR spectra ; cryoscopic measurements ; electrochemistry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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