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  • Articles: DFG German National Licenses  (7)
  • 1995-1999  (7)
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  • Articles: DFG German National Licenses  (7)
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Year
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 66 (1996), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The binding of 2′,3′-cyclic nucleotide 3′-phosphodiesterase isoform 1 (CNP1) to myelin and its association with cytoskeletal elements of the sheath have been characterized with in vitro synthesized polypeptides and purified myelin. We have previously shown that the cysteine residue present in the carboxy-terminal CXXX box of CNP1 is isoprenylated, and that both C15 farnesyl and C20 geranylgeranyl isoprenoids can serve as substrates for the modification. Here, we have mutated the CXXX box to obtain selectively farnesylated CNP1 or geranyl-geranylated CNP1 and found that these two modified forms of CNP1 behave identically in all of the assays performed. Isoprenylation is essential but not sufficient for the binding of in vitro synthesized CNP1 to purified myelin, because a control nonmyelin protein is isoprenylated, yet unable to bind to myelin. In our assay, membrane-bound CNP1 partitions quantitatively into the non-ionic detergent-insoluble phase of myelin, suggesting that CNP1 binds to cytoskeletal elements within myelin. However, isoprenylated CNP1 fails to bind to the cytoskeletal matrix isolated from myelin by detergent treatment, implying that both detergent-soluble and insoluble myelin components are involved in the binding of CNP1. A model for the interactions between CNP1 and myelin is presented, consistent with models proposed for other isoprenylated proteins.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 67 (1996), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: 2′,3′-Cyclic nucleotide 3′-phosphodiesterase (CNP) is an isoprenylated protein enriched in myelin and oligodendrocytes but also present in several other tissues at low levels. CNP binds avidly to membranes and in addition possesses several characteristics of cytoskeletal proteins. The role of isoprenylation in the association of CNP with the cytoskeleton was analyzed by ectopic expression in L cells of epitope-tagged CNP1 and a non-isoprenylated mutant CNP1. Using nonionic detergent extraction, drug-mediated cytoskeletal disruption, and coimmunoprecipitation with an anti-actin antibody, we show that CNP1 is associated with actin-based cytoskeletal elements independently of its isoprenylation status. A control protein, p21c-H-ras, which is also modified by isoprenylation at its carboxyl-terminus, does not bind to cytoskeletal structures as judged by the same criteria. We present a model that accounts for the association of CNP1 with membranes and the cytoskeleton.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1540-8183
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Our knowledge of the identity and functional significance of the pathogenic mechanisms responsible for restenosis and arteriosclerosis in man is still limited. Among others, phenotypic conversion, migration, and proliferation of smooth muscle cells have been suggested to lead to hypercellular neointima. In the present study, we examined intimal cell numbers and cell types in tissue of 23 postangioplasty lesions biopsied by directional atherectomy. using histology and transmission electron microscopy. Comparative tissue analysis was performed for 53 primary lesions. Tissue specimens obtained from coronary (n = 32) and peripheral lesions (n = 44) of 69 symptomatic patients were analyzed. Histological assessment of cell density showed intra- and interlesional variability. A markedly (P 〈 0.001) higher cellularity was found in postangioplasty compared to primary lesions, irrespective of coronary or peripheral origin. Cell density in renarrowed tissue following angioplasty (2 to 30 months) did not significantly decrease regardless of previous balloon dilatation or atherectomy. When categorizing intimal cell density, postangioplasty lesion hypercellularity (75th percentile; 〉 514 cells/mm2) was observed in 12/23 lesions (52%), but hypocellularity (25th percentile; 〈 76 cells/mm2) in none. In contrast, primary lesions were more variable, with hypercellularity in 7/53 plaques (13%), and hypocellularity in 19/53 (36%). Transmission electron microscopic analysis of subcellular features revealed hypocellular plaques to have an extensive build-up of extracellular matrix, with only sparsely embedded smooth muscle cells (SMCs). These SMCs have a range of intermediate to microfilament-rich contractile phenotypes, thereby indicating only marginal metabolic activity. In contrast, hypercellular plaque regions contained predominantly organelle-filled SMCs, irrespective of postangioplasty or primary origin. In conclusion, increased SMC density was observed predominantly in most renarrowed lesions encompassing classical restenoses (2 to 6 months post angioplasty) as well as late recurrent lesions (7 to 30 months postangioplasty). Concordantly, primary lesion hypercellularity is suggested to be related to the formation and progression of native arteriosclerosis.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Bacillus subtilis contains three chromosomally encoded type I signal peptidases (SipS, SipT and SipU), which remove signal peptides from secretory precursor proteins. In the present study the biological function of SipS and the regulation of its synthesis were analysed. Unlike the type I signal peptidase of Escherichia coli, SipS was essential neither for protein secretion nor viability of the cell. However, in the absence of SipS the rate of processing of several preproteins was reduced, and four of the seven major secreted proteins of B. subtilis were hardly detectable in the growth medium. Surprisingly, the processing of Bacillus amyloliquefaciensα-amylase and the secretion of at least two endogenous B. subtilis proteins was improved in the absence of SipS. These findings indicate that the substrate preference of SipS differs from that of SipT and SipU, and that SipS is an important factor determining the efficiency of protein secretion in B. subtilis. SipS is transcribed in a growth phase- and medium-dependent manner. In minimal medium, the growth phase-dependent transcription of sipS is controlled by the DegS–DegU two-component regulatory system, indicating that the expression of sipS is regulated by the same factors that control the expression of most genes for secreted degradative enzymes. Our observations suggest that B. subtilis can modulate its capacity and specificity for protein secretion through the controlled expression of sipS.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford BSL : Blackwell Science Ltd
    Molecular microbiology 19 (1996), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Elastase of Pseudomonas aeruginosa is synthesized as a pre-proprotein. The propeptide has been shown to inhibit the enzymatic activity of elastase. In this study, we investigated a possible additional role of the propeptide in the folding and secretion of the enzyme. When elastase was expressed in Escherichia coli without its propeptide, no active elastase was produced. The enzyme was poorly released from the cytoplasmic membrane and, depending on the expression level, it was either degraded or it accumulated in an inactive form in the cell envelopes, probably as aggregates. Since proper folding is required for the release of translocated proteins from the cytoplasmic membrane and for the acquirement of a stable and active conformation, these results suggest that the propeptide is involved in the proper folding of the elastase and that it functions as an intramolecular chaperone. When mature elastase was expressed without its propeptide in P. aeruginosa, the enzyme was not secreted, and it was degraded. Therefore, proper folding of mature elastase appears to be required for secretion of the enzyme. Expression of the propeptide, as a separate polypeptide, in trans with mature elastase resulted in the formation of active elastase. This active enzyme was secreted in P. aeruginosa. Apparently, the propeptide can also function as an intermolecular chaperone.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1420-911X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung SAPALDIA, die Schweizer Studie Luftschadstoffe und Lungenkrankheiten bei Erwachsenen, konzentriert sich auf die langfristigen gesundheitlichen Auswirkungen von tiefen bis mässig erhöhten Konzentrationen von Luftschadstoffen, wie sie typischerweise in verschiedenen Gebieten der Schweiz vorkommen. Ziel der 1991 durchgeführten Querschnittstudie SAPALDIA war die Bestimmung der Prävalenz von Asthma bronchiale, chronischer Bronchitis und allergischen Beschwerden in der erwachsenen Bevölkerung der Schweiz sowie die identifizierung und Quantifizierung möglicher Einflussfaktoren. Dazu gehören sowohl individuelle (Rauchverhalten, Allergiestautus, familiäre Anamnese, Belastung am Arbeitsplatz) als auch umweltbedingte Faktoren (Raumluftbelastung, Aussenluftverschmutzung, inhalative Allergene, Klima). Ein weiteres Ziel der Studie war die identifizierung von Personen, bei denen das Auftreten von Symptomen während einer zweijährigen Beobachtungsperiode zu erwarten war und die deshalb in die SAPALDIA-Längsschnittstudie aufgenommen werden konnten. Der vorliegende Artikel stellt die methodische Basisdokumentation für die SAPALDIA-Querschnittstudie dar. Die Untersuchungsinstrumente und die verwendeten Standardisierungsmethoden werden vorgestellt und diskutiert. Eine volle Untersuchung umfasste folgende Bestandteile: ein Computer-gestütztes Interview mit einem standardisierten Fragebogen, eine Blutentnahme für serologische Untersuchungen, Allergie-Haut-Tests, eine Bestimmung des endexpiratorischen CO in der Ausatmungsluft, eine Messung der Körpergrösse, eine Lungenfunktionsprüfung und anschliessend je nach deren Resultat entweder einen inhalativen Provokationstest mit Methacolin oder einen Bronchodilatationstest. Mit 9651 Teilnehmerinnen und Teilnehmern wurde eine Beteiligung von 59,3% erzielt. Die Beteiligung bel den verschiedenen Tests, die Merkmale der Teilnehmer sowie diejenigen der Nicht-Teilnehmerinnen und Nicht-Teilnehmer, ermittelt anhand von Informationen aus Telephonbefragungen und kurzen schriftlichen Fragebogen, werden beschrieben und diskutiert.
    Abstract: Résumé Le projet suisse SAPALDIA sur la pollution atmosphérìque et les maladies respiratoires chez l'adulte étudie les effets sur la santé des polluants de l'air à des concentrations moyennement élevées telles qu'on les mesure typiquement dans les différentes régions de Suisse. L'étude transversale réalisée en 1991 visait à déterminer la prévalence de l'asthme bronchique, de la bronchite chronique et des allergies respiratoires dans la population adulte en Suisse ainsi qu'à identifier et à quantifier les facteurs d'influence, soit de nature individuelle (tabagisme, status allergique, anamnèse familiale, occupation) soit environnementale (pollution de l'atmosphère intérieure ou extérieure, allergènes inhalés, climat). Un autre but de l'étude transversale était d'identifier des personnes présentant un risque significatif de développer des symptômes au cours d'une étude de surveillance longitudinale (réalisée en 1992 et 1993). Cet article représente la documentation méthodologique de l'étude transversale SAPALDIA. Les instruments de l'étude et les méthodes de standardisation sont présentés et discutés L'examen médical consistait en un interview assisté par ordinateur en utilisant un questionnaire standardisé, en un prélèvement de sang pour des tests sérologiques, en tests cutanés d'allergie, en mesure du CO en fin d'expiration et en un examen de fonctions pulmonaires suivi d'un test de provocation à la methacholine ou d'un test de bronchodilatation selon le résultat de la spirometrie. La participation et les caractéristiques des 9651 participants-représentant 59.3% de l'échantillon-sont présentées et discutées. Au moyen d'interviews téléphoniques et de courts questionnaires écrits, les caractéristiques des non-participants ont pu être comparées à celles des participants
    Notes: Summary SAPALDIA-the Swiss Study on Air Pollution and Lung Diseases in Adults-focuses on the long term health effects of low to moderate levels of air pollutants as typically seen in different parts of Switzerland. The aim of the SAPALDIA cross-sectional study carried out in 1991 was to determine the prevalence of bronchial asthma, chronic bronchitis and allergic conditions in the adult population of Switzerland and to identify and to determine the respective importance of potentially influencing factors. These could be both personal (smoking habits, allergy status, family history, occupation) and environmental (outdoor and indoor pollution, aeroallergens, climate). A further aim of the cross-sectional study consisted in the identification of individuals susceptible to present symptoms during a two year observation period and to be included in the SAPALDIA follow-up study. This technical report represents the methodological documentation for the cross-sectional study of SAPALDIA. The instruments and the methods of standardisation are presented and discussed. The medical examination consisted of a computerised interview using a standardised questionnaire, the taking of a blood sample for serological tests, allergy skin testing, the measurement of endexpiratory CO and body height, and pulmonary function testing followed by methacholine challenge testing or bronchodilatation testing. The pattern of participation and the 9651 participants of the study, representing 59.3% of the sample, are described. Based on information on non-participants gained by telephone interviews and mailed short questionnaires, possible selection biases are quantified and discussed.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 238 (1996), S. 73-86 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Considering the fundamentals of the capillary rheometry with the known correction method according to Rabinowitsch and Bagley, the traditional method to determine the die inlet pressure and the wall shear stress value is described.For some materials this method can lead to an incorrect assessment of the flow properties since a linear pessure drop in the dies is assumed. Therefore, a new method for direct shear stress determination as well as the necessary measuring device are described. This is a die which can be integrated in-line and determines the reac-tion force of the flowing melt onto the die wall on the basis of a die section resting on piezo-force transducers.The measuring results show that when determining the flow properties of materials with a potential to form structures during the flow process, e. g. LCP, the in-line die determines the correct wall shear stresses. With the classical method of capillary rheometry, however, comparable results for such materials can only be obtained if additional assumptions concerning the pressure profile are made.
    Notes: Ausgehend von den Grundlagen zur Kapillarrheometrie mit den bekannten Korrekturverfahren nach Rabinowitsch und Bagley wird das traditionelle Verfahren zur Ermittlung des Düseneinlaufdrucks sowie des Wandschubspannungswerts dargestellt. Dieses Verfahren kann bei manchen Materialien zur fehlerhaften Bewertung des Fließverhaltens führen, da ein linearer Druckabfall in den Meßdüsen unterstellt wird. Daher wird eine neue Methode zur direkten Schubspannungsermittlung vorgestellt sowie die dazu notwendige Meßeinrichtung beschrieben. Es handelt sich dabei um eine in-line integrierbare Düse, die auf der Basis eines auf Piezokraftaufnehmern gelagerten Düsenabschnitts die Reaktionskraft der strömenden Schmelze auf die Düsenwandung ermittelt.Die Meßergebnisse zeigen, daß bei der Ermittlung der Fließeigenschaften von Materialien, die ein Potential zur Strukturbildung während des Fließvorganges aufweisen, wie z. B. flüssigkristalline Polyester (LCP), mit der In-line-Düse korrekte Wandschubspannungen erhalten werden. Mit der klassischen Methode der Kapillarrheometrie hingegen können bei solchen Materialien nur dann vergleichbare Ergebnisse gewonnen werden, wenn zusätzliche Annahmen über den Druckverlauf in der Meßdüse gemacht werden.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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