TY  - JOUR
A1  - Maueler, W.
A1  - Eigenbrodt, E.
A1  - Schartl, Manfred
T1  - Intermediary metabolism of normal and tumorous tissue of Xiphophorus (Teleostei: Poeciliidae)
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61855
ER  - 
TY  - JOUR
A1  - Barnekow, A.
A1  - Schartl, Manfred
T1  - Comparative studies on the src proto-oncogene and its gene product pp60\(^{c-src}\) in normal and neoplastic tissues of lower vertebrates
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61869
ER  - 
TY  - JOUR
A1  - Stopper, Helga
A1  - Jones, H.
A1  - Zimmermann, U.
T1  - Large scale transfection of mouse L-cells by electropermeabilization
N2  - Mouse L-cells were transfected by electropenneabilization using the selectable plasmid pSV2-neo which confers resistance to G-418 (Geneticin). 1be DNA concentration used was 1 l'gfml, the field strength was 10 kV fcm, the duration of the pulse was S ~s. Transfeetion yield was optimal at a temperature of 4°C when using a time in between consecutive pulses of 1 minute compared to shorter (of the order of seoonds) or Ionger (3 minutes) time intervals. A more detailed study of the relationship between the number of pulses applied (up to 10) and transfection yield showed it to be almost linear in this range at 4 o C. The yield of transfectants in response to 10 pulses was up to 1000 per 106 cells (using 3.3 pg DNA per cell). The inßuence of the growth phase of the cells on the transfection yield and I or the subpopulation of the mouse L--ceU line used was shown. Furthennore the clone yield depended on the DNA per ceU ratio within a very small range.
KW  - Toxikologie
KW  - Electrical breakdown
KW  - Electropermeabilization
KW  - Volume distribution
KW  - Gene transfer
KW  - Transfection
KW  - (Mouse L-cell)
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63497
ER  - 
TY  - JOUR
A1  - Holler, E.
A1  - Fischer, H.
A1  - Weber, C.
A1  - Stopper, Helga
A1  - Steger, H.
A1  - Simek, H.
T1  - A DNA polymerase with unusual properties from the slime mold Physarum polycephalum
N2  - Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase cx on phosphocellulose and from each other on heparin-Sepharose. Form HS1 enzymewas 30-40% pure and form HS2 enzyme 60% with regard toprotein contents of the preparations. Form HS2 enzymewas generated from form HS1 enzyme on prolonged standing of enzyme preparations. The DNA polymerases were obtained as complexes of a 60-kDa protein associated with either a 135-kDa (HS1) or a 110-kDa (HS2) DNA-polymerizing polypeptidein a 1:1 molar stoichiometry. The biochemical function of the 60-kDa protein remained unknown. The complexes tended to dissociate during gradient centrifugation and during partition chromatography as weil as during polyacrylamide gradient gel electrophoresis under nondenaturing conditions at high dilutions of samples. Both forms existed in plasmodia extracts, their proportions depending on several factors including those which promoted proteolysis. The DNA polymerases resembled eucaryotic DNA polymerase ß by several criteria and were functionally indistinguishable from each other. It is suggested that lower eucaryotes contain repair DNA polymerases, which are similar to those of eubacteria on a molecular mass basis.
KW  - Toxikologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63501
ER  - 
TY  - JOUR
A1  - Zimmermann, U.
A1  - Stopper, Helga
T1  - Elektrofusion und Elektropermeabilisierung von Zellen : Eine neuartige Methode der Biotechnologie zur gezieltenVeränderung der genetischen Eigenschaften von Zellen
N2  - No abstract available
KW  - Toxikologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63514
ER  - 
TY  - JOUR
A1  - Schneider-Schaulies, Jürgen
A1  - Schimpl, A.
A1  - Wecker, E.
T1  - Kinetics of cellular oncogene expression in mouse lymphocytes II. Regulation of c-fos and c-myc gene expression
N2  - Newly isolated lymphocytes from mousespleensexpress the c-fos oncogene even in the absence of mitogen with maximal mRNA levels 60 min post preparation of single cell suspension, whereas c-myc mRNA Ievels increase only after mitogenic Stimulation with maximal mRNA Ievels 6 h post Stimulation. The half-lives of c-fos mRNA are generally very short; they increase from 14 min (after 30 min of culture) to 70 min (after 2 h of culture). The half-lives of c-myc mRNA decrease from 50 min (at 2 and 6 h post stimulation with concanavalin A) to 12 min (at 48 h post stimulation). The c-fos gene transcription is already tumed on in time-0 lymphocytes 10 min after disruption of the organ structure of the spleens and is down-regulated after 2 h and later. In nuclear run-on experiments with nonstimulated lymphocytes there is already significant transcription of the first exon of c-myc, but almost no elongation of the transcript to exon 2 and 3. In concanavalin A-treated lymphocytes elongation is stimulated about 5-fold within 6 h and returns to background levels at 48 h post Stimulation. · The nuclear run-on analyses of nonactivated lymphocytes showed a signal for RNA complementary to c-myc mRNA detected with a probe specific for the exon 1/intron 1 boundary of c-myc, which disappeared with increasing time of concanavalin A Stimulation. This anti-sense transcription may play a role in regulating the elongation of cmyc transcripts.
KW  - Lymphozyt
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54823
ER  - 
TY  - JOUR
A1  - Engels, Bernd
A1  - Peyerimhoff, S.D.
A1  - Davidson, E.R.
T1  - Calculation of hyperfine coupling constants : An ab initio MRD-CI study for nitrogen to analyse the effects of the basis sets and CI parameter
N2  - The hyperfine coupling constant for the nitrogen atom is evaluated by large-scale MRD-CI calculations. A detailed analysis of the charge density at the nucleus and the spin polarization in the ls and 2s shell as a function of various technical parameters is undertaken. Various (s, p) AO basis sets and the inftuence of correlation orbitals is investigated as weil as selection threshold and other properlies in CI calculations. The best value, obtained for the isotropic hyperfine coupling constant in an s, p, d basis, based on theoretical judgment of' best' quantities, is 9·9 MHz compared to 10·4509 MHz.
KW  - Organische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58784
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ulmer, E.
A1  - Fasske, E.
A1  - Schmidt, G.
T1  - Isolation and characterization of coliphage Omega18A specific for Escherichia coli O18ac strains
N2  - The bactedophage Q18A, specific for Escherichia coli 018ac srrains, was isolated frorn sewage. The results of host range and conjugation experiments showed that the sensitivity of bacteria to the phage is associated with rhe presence of 018ac antigens. With sorne of rhe 018 strains rhe phage Q18A produces clear Iysis on bacterial lawns only when applied at a high multiplicity and moreover the phage does not multiply. With rhe help of the phage Ql8A, E. coli 0 18ac strains could be divided inro rwo serologically clistinct subgroups called 018A and 018A1• E. coli strains belanging to the sugroup 0 ISAare sensitive to phage Q t8A wheteas bacteria of subgroup A1 are resistanr.
N2  - Der Bakteriophage Q18A, der spezifisch Escherichia coli 018ac Bakterien lysierr, wurde aus Abwasser isoliert. Die Untersuchungen des Wirtsbereichs und Konjugationsversuche zeigten, daß die Sensitivität der Bakterien gegenüber dem Phagen mit dem Vorhandensein des 0 '18ac Antigens assoziiert ist. Bei eir1igen 0 18 Stämmen wird nur bei Anwendung hoher Phagenkonzentrationen eine klare Lysis auf dem Bakterienrasen erzeugt. Darüber hinaus läßt sich der Phage auf diesen Stämmen nicht vermehren. Mit Hilfe des Phagen Q l8A konnten E, wli 0 18ac Stämme in zwei serologische Subgruppen unteneilt werden, die als 0 lHA und 0 l8A 1 bezeichnet werden. E. coli Bakterien der Subgruppe 0 ISA sind gegenüber dem Phagen Ql8A sensitiv und diejenigen der Subgruppe 0 18A 1 sind resistent.
KW  - Escherichia coli
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73001
ER  - 
TY  - JOUR
A1  - Feuerstein, G.
A1  - Leader, P.
A1  - Sirén, Anna-Leena
A1  - Braquet, P.
T1  - Protective effect of PAF-acether antagonist, BN 52021, in trichothecen toxicosis
N2  - Trichothecenes are mycotoxins which produce Iethai toxicosis in humans and animals, yet no adequate therapeutic regimen has been developed. This study provides evidence that the selective platelet activating factor (PAF) antagonist, BN 52021 (5-15 mg/kg i.v.) can prolong the survival of conscious rats exposed to a highly Iethai T -2 toxicosis. These data also suggest that P AF is an important mediator of this unique toxicosis.
KW  - Neurobiologie
KW  - T-2 toxin
KW  - mycotoxin
KW  - PAF-acether
KW  - BN 52021
KW  - rat
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63244
ER  - 
TY  - JOUR
A1  - Labroo, V. M.
A1  - Cohen, L. A.
A1  - Lozovsky, D.
A1  - Sirén, Anna-Leena
A1  - Feuerstein, G.
T1  - Dissociation of the cardiovascular and prolactin-releasing  activities of TRH by histidine replacement
N2  - No abstract available
KW  - Neurobiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63253
ER  - 
TY  - JOUR
A1  - Feuerstein, G.
A1  - Sirén, Anna-Leena
T1  - Opioid peptides: A role in hypertension? [Brief Review]
N2  - This review is an attempt to highlight evidence that may implicate the endogenaus opioid system in the pathogenesis of hypertension in humans. The evidence raised includes biochemical, physiological, pharmacological, and behavioral studies con~ucted in in vitro andin vivo systems, experimental models of hypertension, and hornans with essential hypertension. While the compelling biochemical and pharmacological evidence in experimental animals clearly shows the presence of opioid peptides and their receptors in strategic sites of cardiovascular control and potent cardiovascular response to opioid peptides, opioid antagonists show no consistent blockade or reversal of hypertension in experimental animals or humans. One possible explanation for this phenomenon could be the vast redundancy in systems regulating blood pressure (i.e., the blockade ofone system stillleaves many other systerils fully able to rapidly offset the eliminated system). Regarding the opioid system, the situation is much more complex, since some opioid receptors (\(\mu\)-type) niediate pressor responses, while other receptors (\(\kappa\)type) mediate depressor responses. Therefore, nonselective opioid receptor antagonists (e.g., naloxone), which block both types ofreceptors, can be devoid ofany cardiovascular activity, while a selective \(\mu\)-receptor antagonist or a selective arid potent \(\kappa\)-receptor agonist may produce the desired antihypertensive elfect. A combination of both actions (i.e., a drug that is both \(\mu\)antagonist and a \(\kappa\)antagonist) might be even more advantageous. Until such compounds are developed, this hypothesis will be hard to prove.
KW  - Neurobiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63262
ER  - 
TY  - JOUR
A1  - Kleene, R.
A1  - Pfanner, N.
A1  - Pfaller, R.
A1  - Link, T. A.
A1  - Sebald, Walter
A1  - Neupert, W.
A1  - Tropschug, M.
T1  - Mitochondrial porin of Neurospora crassa: cDNA cloning, in vitro expression and import into mitochondria
N2  - No abstract available
KW  - Biochemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62566
ER  - 
TY  - JOUR
A1  - Römisch, J.
A1  - Tropschug, M.
A1  - Sebald, Walter
A1  - Weiss, H.
T1  - The primary structure of cytochrome c\(_1\) from Neurospora crassa
N2  - No abstract available
KW  - Biochemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62578
ER  - 
TY  - JOUR
A1  - Barnekow, A.
A1  - Paul, E.
A1  - Schartl, Manfred
T1  - Expression of the c-src protooncogene in human skin tumors
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61870
ER  - 
TY  - CHAP
A1  - Ellgring, Johann Heinrich
T1  - Zur Entwicklung der Mimik als Verständigungsmittel
N2  - No abstract available
KW  - Mimik
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56811
ER  - 
TY  - JOUR
A1  - Künzler, Jan
T1  - Grundlagenprobleme der Theorie symbolisch generalisierter Kommunikationsmedien bei Niklas Luhmann
N2  - Niklas Luhmanns Version einer Theorie symbolisch generalisierter Medien soll mit der Version Talcott Parsons' konfrontiert werden, indem die grundbegrifflichen Differenzen aufgesucht werden, die Luhmanns Revisionen motivieren - Revisionen, die trotz ihrer Radikalität in der Diskussion bisher vernachlässigt wurden. Es wird versucht, eine Zwischen bilanz der theoretischen Weiterentwicklung von Luhmanns Version zu ziehen. Dabei treten Inkonsistenzen zutage, die sich dem prekären Verhältnis der Medien zur Sprache verdarrken: Der Code-Begriff ist nicht eindeutig bestimmt; die Engführung von Wahrheitsmedium, Logik und Wissenschaftssystem bedeutet eine Verkennung der Logizität von Sprache; es bestehen Widersprüche zwischen der kommunikativen und der evolutiven Rolle der Sprache. Luhmanns Versuch der Marginalisierung von Sprache bleibt mithin nicht ohne Auswirkungen auf die Schlüssigkeit der Medientheorie.
KW  - Soziologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-50773
ER  - 
TY  - JOUR
A1  - Feuerstein, Giora
A1  - Sirén, Anna-Leena
T1  - The Opioid System in cardiac and vascular regulation of normal and hypertensive states
N2  - The endogenous opioid system includes three major families of peptides: dynorphins (derived from pre-proenkephalin B), endorphins (derived from pre-proopiomelanocortin), and enkephalins (derived from pre-proenkephalin A). Multiple species of opioid peptides are derived from these major precursors and many of them possess potent cardiovascular properties. Opioid peptides and opioid receptors, of which multiple forms have been defined, are present in the central nervous system and peripheral neural elements. In the central nervous system, opioid peptides and receptors are found in forebrain and hindbrain nuclei involved in baroregulation, sympathoadrenal activation, and several other vital autonomic functions. In the periphery, opioid peptides are found in autonomic ganglia, adrenal gland, heart, and other organs; multiple opioid receptors are also found in vascular tissue, heart, and kidneys. Although little is known to date on the regulatory mechanisms of the opioid system in normal cardiovascular states, it became clear that cardiovascular stress situations substantially modify the activity of the endogenous opioid system. The purpose of this review is to clarify the sites of interaction of the opioid system with all major components of the cardiovascular system and indicate the potential role of this system in the ontogenesis of cardiac malfunction, vascular diseases, and hypertension.
KW  - Medizin
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47418
ER  - 
TY  - JOUR
A1  - Feuerstein, G.
A1  - Sirén, Anna-Leena
T1  - Cardiovascular effects of enkephalins
N2  - Enkephalins and their receptors are found in neurons and nerve terminals known to be involved in central cardiovascular control as well as the peripheral sympathetic and parasympathetic systems. Enkephalins and opioid receptors were also iden tified in the heart, kidneys, and blood vessels. The enkephalins interact with several specific receptors, of which p, 0, and K have been best characterized. Enkephalins administered to humans or animals produce cardiovascular effects which depend on the spedes, route of administration, anesthesia, and the selectivity for receptor subtype. While little information exists on the role of enkephalins in normal cardiovascular control, current data suggest that enkephalins might have a role in cardiovascular stress responses such os in shock and trauma.
KW  - Medizin
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-49048
ER  - 
TY  - JOUR
A1  - Wehgartner, Irma
T1  - Das Ideal maßvoller Liebe auf einem attischen Vasenbild
N2  - Neues zur Lekythos F 2705 im Berliner Antikenmuseum
KW  - Attika
KW  - Vasenmalerei
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53438
ER  - 
TY  - JOUR
A1  - Schreck, Michael
A1  - Christl, Manfred
T1  - Generation and Interception of 1-Oxa-3,4-cyclohexadiene
N2  - No abstract available
KW  - Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31601
ER  - 
TY  - JOUR
A1  - Schneider-Schaulies, Jürgen
A1  - Knauer, R.
A1  - Schimpl, A.
A1  - Wecker, E.
T1  - Cellular Oncogenes and lymphocyte activation
N2  - No abstract available
KW  - Lymphozyt
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54836
ER  - 
TY  - JOUR
A1  - Christl, Manfred
A1  - Schreck, Michael
T1  - 1,2,3,5,8,8a-Hexahydronaphthalin aus 1,2-Cyclohexadien
N2  - Reaktionen von 1,3-Butadien und einigen seiner Methylderivate mit 1a und 1- Methyl-1,2-cyclohexadien 1b sowie den Übergang der [2 + 2]-Cycloaddukte 2 und 3 in das bisher unbekannte 1,2,3,5,8,8a-HexahydronaphthaJin 4a und einige seiner Methylderivate
KW  - Chemie
KW  - Butadien
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31656
ER  - 
TY  - JOUR
A1  - Sirén, Anna-Leena
A1  - Feuerstein, Giera
T1  - Central autonomic pharmacology of thyrotropin releasing hormone
N2  - Thyrotropin releasing hormone (TRH, I-pyroglutamyl-l-histidyl-l-prolinamide) was the fIrst hypothalamic releasing SUbstance to be isolated, chemically characterized and synthetized /1/. The studies to date have revealed that the thyrotropin release from the pituitary gland is only one of the numerous actions of TRH. In addition to its endocrine actions (TSH and prolactin release) this tripeptide has central nervous system actions totally unrelated to its effects on the hypothalamo-pituitary axis. This review aims to summarize the studies on the central nervous system' actions of TRH with special emphasis on the autonomic pharmacology of this peptide.
KW  - Medizin
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-49051
ER  - 
TY  - JOUR
A1  - Singer, Gabriele
A1  - Heusinger, Georg
A1  - Mosandl, Armin
A1  - Burschka, Christian
T1  - Stereoisomere Aromastoffe: XVI. Struktur und Eigenschaften optisch reiner 2-Methyl-4-propyl-1,3-oxathian-3-oxide
N2  - No abstract available
KW  - Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46684
ER  - 
TY  - JOUR
A1  - Schenk, Wolfdieter A.
A1  - Rueb, Doris
A1  - Burschka, Christian
T1  - Die Koordinationschemie C=S-Funktioneller Verbindungen: VI. Reaktionen an \(\eta^1-, \eta^2\)- und \(\eta^3\)-Dithioester-Komplexen
N2  - No abstract available
KW  - Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46699
ER  - 
TY  - JOUR
A1  - Hess, Günter
T1  - Die Arche Noah auf dem Hubland : Tagebuchnotizen zur zweiten Folge der Werkstattgespräche mit Autoren der deutschen Gegenwartsliteratur
N2  - Tagebuchnotizen über die Werkstattgespräche in der Universitätsbibliothek Würzburg. - Martin Walser 12. November 1986 - Günter Kunert 10. Dezember 1986 - Hermann Burger 14. Januar 1987 - Peter Rühmkopf 18. Februar 1987
KW  - Würzburg / Werkstattgespräche mit Autoren der Deutschen Gegenwartsliteratur
KW  - Autorenlesung
KW  - Wuerzburg
KW  - reading
KW  - author
KW  - contemporary literature
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-52233
ER  - 
TY  - JOUR
A1  - Schenk, Wolfdieter
A1  - Rueb, Doris
A1  - Burschka, Christian
T1  - Die Koordinationschemie C=S-funktioneller Verbindungen V: Dithioester als \(\eta^1-, \eta^2-\), und \(\eta^3\)-Liganden in Übergangsmetallkomplexen
N2  - No abstract available
KW  - Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46736
ER  - 
TY  - JOUR
A1  - Wieber, Markus
A1  - Fetzer-Kremling, Isa
A1  - Reith, Hildegard
A1  - Burschka, Christian
T1  - Synthese und Struktur von Phenyltetra(acetato)stiboran
T1  - Synthesis and structure of Phenyltetra(acetato)stiborane
N2  - No abstract available
KW  - Chemie
KW  - Phenyltetra(acetato)stiborane
KW  - Synthesis
KW  - X-Ray Crystal Structure
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47137
ER  - 
TY  - CHAP
A1  - Heusermann, U.
A1  - Nöthling, R.
A1  - Hansmann, M. L.
A1  - Ulrichs, Karin
T1  - Immunhistochemische und immunelektronenmikroskopischeUntersuchungen zum Vorkommen von dendritischen Zellen im Pankreas der Ratte
T1  - Immunohistochemical and immune electron microscopy studies of the occurrence of dendritic cells in the pancreas of the rat
N2  - Dendritic cells, first described by STEINMAN and COHN in the mouse spleen and now called lymphoid dendritic cells (LDC), were investigated in the rat pancreas with the monoclonal antibodies 29AI-L. T. and MRC-OX17, which both recognize the la-antigen immunohistochemically and immune electron microscopically. la-positive cells with a dendritic morphology were found in the connective tissue of the cxocrine and endocrine pancreas. Immune e1ectron microscopically, the Ia-antibodies were 10- calized on the cell surface and in sm all vesicles. A small portion of the la-positive cells showed additional acid phosphatase positivity, i. e. were la-positive macrophages. The other la-positive cells were probably LDC, which may be important in the elimination of foreign antigens, e. g. bacteria and vIruses.
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45689
ER  - 
TY  - JOUR
A1  - Ulrichs, Karin
A1  - Nöthling, R.
A1  - Keller, R.
A1  - Heusermann, U.
A1  - Müller-Buchholtz, W.
T1  - Genetically determined variation of constitutive major histocompatibility complex class II antigen expression in various rat strains and cell types
N2  - No abstract available
KW  - Chirurgie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44769
ER  - 
TY  - JOUR
A1  - Müller-Buchholtz, W.
A1  - Leyhausen, G.
A1  - Peterson, P.
A1  - Schubert, G.
A1  - Ulrichs, Karin
T1  - A simple methodological principle for large scale extraction and purification of collagenase-digested islets
N2  - No abstract available
KW  - Chirurgie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44770
ER  - 
TY  - JOUR
A1  - Schreck, Michael
A1  - Christl, Manfred
T1  - Freisetzung und Abfangreaktionen von 1-Oxa-3,4-cyclohexadien
N2  - No abstract available
KW  - Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31597
ER  - 
TY  - JOUR
A1  - Lohse, M. J.
A1  - Böser, S.
A1  - Klotz, Karl-Norbert
A1  - Schwabe, U.
T1  - Affinities of barbiturates for the GABA-receptor complex and A\(_1\) adenosine receptors: A possible explanation of their excitatory effects
N2  - The effects of barbiturates on the GABA·receptor complex and the A\(_1\) adenosine receptor were studied. At the GABA-receptor complex the barbiturates inhibited the binding of [\(^{35}\)S]t-butylbicyclophosphorothionate [\(^{35}\)S]TBPT) and enhanced the binding of [\(^3\)H]diazepam. Kinetic and saturation experiments showed that both effects were allosteric. Whereas all barbiturates caused complete inhibition of [\(^{35}\)S]TBPT binding, they showed varying degrees of maximal enhancement of [\(^3\)H]diazepam binding; (±)methohexital was idenafied as the most efficacious compound for this enhancement. At the A\(_1\) adenosine receptor all barbiturates inhibited the binding of [\(^3\)H]N\(^6\)-phenylisopropyladenosine (\(^3\)H]PIA) in a competitive manner. The comparison of the effects on [\(^3\)H]diazepam and [\(^3\)H]PIA binding showed that excitatory barbiturates interact preferentially with the A\(_1\) adenosine receptor, and sedative/anaesthetic barbiturates with the GABA-receptor complex. It is speculated that the interaction with these two receptors might be the basis of the excitatory versus sedative/ anaesthetic properties of barbiturates.
KW  - Toxikologie
KW  - GABA-receptor complex
KW  - Adenosine receptors
KW  - Barbiturates
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60250
ER  - 
TY  - JOUR
A1  - Büsser, M. T.
A1  - Lutz, Werner K.
T1  - Stimulation of DNA synthesis in rat and mouse liver by various tumor promoters
N2  - In order to investigate whether the Stimulation of liver DNA synthesis might be used to detect one class of hepatic tumor promoters, the incorporation of orally administered radiolabelled thymidine into liver DNA was detennined in rats and mice 24 h after a single oral gavage of test compounds at various dose Ievels. Three DNA-binding hepatocarcinogens, aflatoxin B1; benzidine and carbon tetrachloride, did not stimulate but rather inhibited DNA synthesis (not for CCla). Four hepatic tumor promoters, clofibrate, DDT, phenobarbital and thioacetamide, gave rise to a Stimulation in a dosedependent manner. Single oral doses between 0.02 and 0.3 mmol/kg were required to double the level of thymidine incorporation into liver DNA (= doubling dose, DD). Differentes between species or sex as obsprved in long-term carcinogenicity studies were reflected by a different stimulation of liver DNA synthesis. In agreement with the bioassay data, aldrin was positive only in male mice (DD = 0.007 mmol/kg) but not in male rats or female mice. 2,3, 7,8-TCDD was positive in male mice (DD = 10\(^{-6}\) mmol/kg) andin female rats (DD = 2 x 10\(^{-6}\) mmol/kg) but not in male rats. The assay was also able to distinguish between structural isomers with different carcinogenicities. [alpha]Hexachlorocyclohexane stimulated Iiver DNA synthesis with a doubling dose of about 0.2 mmol/kg in male rats whereas the [gamma]isomer was ineffective even at l mmol/kg. So far, only one result was inconsistent with carcinogenicity bioassay data. The different carcinogenicity of di(2-ethylhexyl)adipate (negative in rats) and di(2-ethylhe.xyl)phthalate (positive) was not detectable. 8oth plasticizers were positive in.this short-term system with DD's of 0. 7 mmol/kg for DEHA and 0.5 mmol/kg for DEHP. The proposed assay is discussed as an attempt to devise short-term assays for carcinogens not detected by the routine genotoxicity test systems.
KW  - Toxikologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60908
ER  - 
TY  - JOUR
A1  - Bösch, R.
A1  - Friederich, U.
A1  - Lutz, Werner K.
A1  - Brocker, E.
A1  - Bachmann, M.
A1  - Schlatter, C.
T1  - Investigations on DNA binding in rat liver and in Salmonella and on mutagenicity in the Ames test by emodin, a natural anthraquinone
N2  - Emodin (1,6,8-trihydroxy-3-methylanthraquinone), an important aglycone found in natural anthraquinone glycosides frequently used in Iaxative drugs, was mutagenic in the Salmonellajmammalian microsome assay (Ames test) with a specificity for strain TA1537. The mutagenic activity was activationdependent with an optimal amount of S9 from Aroclor 1254-treated male Sprague-Dawley rats of 20% in the S9 mix (v jv) for 10 p.g emodin per plate. Heat inactivation of the S9 for 30 min at 60 ° C prevented mutagenicity. The addition of the cytochrome P-448 inhibitor 7,8-benzoflavone (18.5 nmoles per plate) reduced the mutagenic activity of 5.0 p.g emodin per plate to about one third, whereas the P-450 inhibitor metyrapone (up to 1850 nmoles per plate) was without effect. To test whether a metabolite" binds covalently to Salmonella DNA, [10-\(^{14}\)C]emodin was radiosynthesized, large batches of bacteria were incubated with [10-\(^{14}\)C]emodin and DNA was isolated. [G- \(^{3}\)H]Aflatoxin B1 (AFB1) was used as a positive control mutagen known to act via DNA binding. DNA obtained after aflatoxin treatment could be purified to constant specific activity. With emodin, the specific activity of DNA did not remain constant after repeated precipitations so that it is unlikely that the mutagenicity of emodin is due to covalent interaction of a metabolite with DNA. The antioxidants vitamin C and E or glutathione did not reduce the mutagenicity. Emodin was also negative with strain TA102. Thus, oxygen radicals are probably not involved. When emodin was incubated with S9 alone for up to 50 h before heat-inactivation of the enzymes and addition of bacteria, the mutagenic activity did not decrease. It is concluded that the mutagenicity of emodin is due to a chemically stable, oxidized metabolite forming physico-chemical associations with DNA, possibly of the intercalative type. In order to check whether an intact mammalian organism might be able to activate emodin to a DNA-binding metabolite, radiolabelled emodin was administered by oral gavage to male SD rats and liver DNA was isolated after 72 h. Very little radioactivity was associated with the DNA. Considering that DNA radioactivity could also be due to sources other than covalent interactions, an upper limit for the · covalent binding index, CBI = (p.moles chemical bound per moles DNA nucleotides)/(mmoles chemical administered per kg body weight) of 0.5 is deduced. This is 104 times below the CBI of AFB1. The demonstration of a lack of covalent interaction with DNA bothin Salmonellaandin rat liver is discussed in terms of a reduced hazard posed by emodin as a mutagenic drug in use in humans.
KW  - Toxikologie
KW  - DNA binding
KW  - (Rat liver)
KW  - (Salmonella)
KW  - Ames test
KW  - Emodin
KW  - Anthraquinone glycosides
KW  - natural
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60913
ER  - 
TY  - JOUR
A1  - Shephard, S. E.
A1  - Schlatter, C.
A1  - Lutz, Werner K.
T1  - Assessment of the risk of formation of carcinogenic N-nitroso compounds from dietary precursors in the stomach
N2  - A literature review has shown that the daily intakes of various N -nitroso-precursor classes in a typical European diet span five orders of magnitude. Amides in the form of protein, and guanidines in the form of creatine and creatinine, are the nitrosatable groups found most abundantly in the diet, approaching Ievels of 100 g/day and 1 gjday, respectively. Approximately 100 mg of primary amines and amino acids are consumed daily, whereas aryl amines, secondary amines and ureas appear to lie in the 1-10 mg range. The ease of nitrosation of each precursor was estimated, the reactivities being found to span seven orders of magnitude, with ureas at the top and amines at the bottom of the scale. From this infonnation and an assessment of the carcinogenicity of the resulting N-nitroso derivatives, the potential health risk due to gastric in vivo nitrosation was calculated. The combined effects of these risk variables were analysed using a simple mathematical model: Risk = [daily intake of precursor] x [gastric concentration of nitrite]\(^n\) x [nitrosatability rate constant} x [carcinogenicity of derivative]. The risk estimates for the various dietary components spanned nine orders of magnitude. Dietary ureas and aromatic amines combined with a high nitrite burden could pose as great a risk as the intake of preformed dimethylnitrosamine in the diet. In contrast, the risk posed by the in vivo nitrosation of primary and secondary amines is probably negligib1y small. The risk contribution by amides (including protein), guanidines and primary amino acids is intermediate between these two extremes. Thus three priorities for future work are a comprehensive study of the sources and Ievels of arylamines and ureas in the diet, determination of the carcinogenic potencies of key nitrosated products to replace the necessarily vague categories used so far, and the development of short-term in situ tests for studying the alkylating power or genotoxicity of N-nitroso compounds too unstable for inclusion in long-term studies.
KW  - Toxikologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60925
ER  - 
TY  - JOUR
A1  - Grilli, S.
A1  - Lutz, Werner K.
A1  - Parodi, S.
T1  - Possible implications from results of animal studies in human risk estimations for benzene: nonlinear dose-response relationship due to saturation of metabolism
N2  - To date, all risk assessment studies on benzene have been based almost exclusively on epiderniological data. Wehave attempted a more integrated and quantitative evaluation of carcinogenic risk for hurnans, trying to utilize, in addition to the epidemiological data, all data available, specifically data on metabolism, genotoxicity, and carcinogenicity in small rodents. An integrated evaluation of the globality of the available data seems to suggest a progressive saturation of metabolic capacity both for man and rodents between 10 and 100 ppm. The most susceptible target cells seem tobe different in humans (predominant induction of myelogenous leukemia) and small rodents (induction of a wide variety of tumors). Nevertheless, both epidemiological and experimental carcinogenicity data tend to indicate a flattening ofthe response for the highest dosages, again suggesting a general Saturation of mechanisms of metabolic activation, extended to different target tissues. From a quantitative point of view, the data suggest a carcinogenic potency at 10 ppm two to three times higher than that computable by a linear extrapolation from data in the 100 ppm range. These observations are in accord with the recent proposal of the European Economic Community of reducing benzene time-weighted average occupationallevels from 10 to 5 ppm.
KW  - Toxikologie
KW  - Benzene
KW  - Risk estimation
KW  - Carcinogenicity
KW  - Genotoxicity
KW  - Metabolism saturation
KW  - Dose-response relationship
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60936
ER  - 
TY  - JOUR
A1  - Lohse, M. J.
A1  - Klotz, Karl-Norbert
A1  - Lindenborn Fotinos, J.
A1  - Reddington, M.
A1  - Schwabe, U.
A1  - Olsson, R. A.
T1  - 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX) - a selective high affinity antagonist radioligand for A\(_1\) adenosine receptors
N2  - The properties of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) as an antagonist ligand for A\(_1\) adenosirre receptors were examined and conipared with other radioligands for this receptor. DPCPX competitively antagonized both the inhibition of adenylate cyclase activity via A\(_1\) adenosirre receptors and the stimulationvia A\(_2\) adenosirre receptors. The K\(_i\)-values of this antagonism were 0.45 nM at the A\(_1\) receptor of rat fat cells, and 330 nM at the A\(_2\) receptor of human platelets, giving a more than 700-fold A\(_1\)-selectivity. A similar A\(_1\)-selectivity was determined in radioligand binding studies. Even at high concentrations, DPCPX did not significantly inhibit the soluble cAMPphosphodiesterase activity of human platelets. [\(^3\)H]DPCPX (105 Ci/mmol) bound in a saturable manner with high affinity to A\(_1\) receptors in membranes of bovine brain and heart, and rat brain and fat cells (K\(_D\) -values 50-190 pM). Its nonspecific binding was about 1% of total at K\(_D\) , except in bovine myocardial membranes (about 10%). Binding studies with bovine myocardial membranes allowed the analysis of both the high and low agonist affinity states of this receptor in a tissue with low receptor density. The binding properties of [\(^3\)H]DPCPX appear superior to those of other agonist and antagonist radioligands for the A\(_1\) receptor.
KW  - Toxikologie
KW  - Adenosine receptors
KW  - Adenylate cyclase
KW  - Phosphodiesterase
KW  - Xanthines
KW  - Radioligands
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60246
ER  - 
TY  - JOUR
A1  - Pressley, Michael
A1  - Cariglia-Bull, Teresa
A1  - Deane, Shelley
A1  - Schneider, Wolfgang
T1  - Short-term memory, verbal competence, and age as predictors of imagery instructional effectiveness
N2  - No abstract available
KW  - Psychologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62046
ER  - 
TY  - JOUR
A1  - Schneider, Wolfgang
A1  - Körkel, Joachim
A1  - Weinert, Franz E.
T1  - The effects of intelligence, self-concept, and attributional style on metamemory and memory behaviour
N2  - No abstract available
KW  - Psychologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62050
ER  - 
TY  - JOUR
A1  - Hughes, C.
A1  - Hacker, Jörg
A1  - Düvel, H.
A1  - Goebel, W
T1  - Chromosomal deletions and rearrangements cause coordinate loss of hemolysis, fimbriation and serum resistance in an uropathogenic strain of Escherichia coli
N2  - No abstract available
KW  - Infektionsbiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59470
ER  - 
TY  - JOUR
A1  - Marre, R.
A1  - Hacker, Jörg
T1  - Role of S and common type I-fimbriae of Escherichia coli in experimental upper and lower urinary tract infection
N2  - No abstract available
KW  - Infektionsbiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59468
ER  - 
TY  - JOUR
A1  - Schmoll, T.
A1  - Hacker, Jörg
A1  - Goebel, W.
T1  - Nucleotide sequence of the sfaA gene coding for the S fimbrial protein subunit of Escherichia coli
N2  - The sfaA gene of the uropathogenic Escherichia coli 06 strain 536, which is responsible for the determination of the S fimbrial protein subunit, was sequenced. The structural gene codes for a polypeptide of 180 amino acids including a 24-residue N-terminal signal sequence. A size of 15.95 kDa was calculated for the processed SfaA protein. The nucleotide and deduced amino acid sequences show significant homology to those of the F1C fimbria and, to a lesser extent, of the mannose- sensitive hemagglutinating fimbria (FimA, PilA). Only week homology toP fimbriae subunits (F72 , Pap) was found.
KW  - Infektionsbiologie
KW  - Escherichia coli
KW  - Fimbria
KW  - (Nucleotide sequence
KW  - sfaA gene)
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59480
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Schmoll, T.
A1  - Goebel, W.
A1  - Van Die, I.
A1  - Hacker, Jörg
T1  - Comparison of the genetic determinant coding for the S-fimbrial adhesin (sfa) of Escherichia coli to other chromosomally encoded fimbrial determinants
N2  - DNA probes specific for different regions of the S-fimbrial adhesin (sja) determinant were constructed and hybridized with DNA sequences coding for P (F8 and F13), mannose-sensitive hemagglutinating type 1 (FlA), and FlC fimbriae. While the sfa and F1C DNA determinants exhibited homology along their entire lengths, the P-fimbrial and type 1-fimbrial determinants exhibited homology to regions of the sfa duster responsible for the control of transcription and, to a minor extent, to regions coding for proteins involved in biogenesis and/or adhesion of the fimbriae and for the N-terminal part of the fimbrillin subunit.
KW  - Infektionsbiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59499
ER  - 
TY  - JOUR
A1  - Flügel, Rolf M.
A1  - Rethwilm, Axel
A1  - Maurer, Bernd
A1  - Darai, Gholamreza
T1  - Nucleotide sequence analysis of the env gene and its flanking regions of the human spumaretrovirus reveals two novel genes
N2  - Recombinant clonesthat represent the 3' part ofthe genome of the human spumaretrovirus (foamy virus) were established from viral DNA and from DNA complementary to viral RNA. The recombinant clones were characterized by blot hybridizations and nucleotide sequence analysis. The deduced protein sequence of the clones at their 5' ends was found to be homologous to the 3' domain of retroviral reverse transcriptases. Downstream of a small intergerne pol-env region a long open reading frame of 985 amino acid residues was identified that according to its genomic location, size, glycosylation signals, and hydrophobicity protile closely resembles the lentiviral env genes. The spumaretroviral env gene is followed by two open reading frames, termed bel-l and bel-2 which are located between env and the long terminal repeat region. The long terminal repeat of 1259 nucleotides is preceded by a polypurine tract and contains the canonical signal sequences characteristic for transcriptional regulation of retroviruses. The provisional classitication of the spumaretrovirus subfamily is discussed.
KW  - Virologie
KW  - foamy retrovirus
KW  - DNA sequence
KW  - reverse transcriptase
KW  - transmembrane protein
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61509
ER  - 
TY  - JOUR
A1  - Rethwilm, Axel
A1  - Darai, G.
A1  - Rösen, A.
A1  - Maurer, Bernd
A1  - Flügel, Rolf M.
T1  - Molecular cloning of the genome of human spumaretrovirus
N2  - DNA ofhuman spumaretrovirus (HSRV) was cloned from both cDNA and from viral DNA into phage A and bacterial plasmid vectors. The recombinant plasm.ids harboring viral DNA were characterized by Southern blot hybridization and restriction mapping. Physical maps were constructed from cDNA and found to be colinear with the restriction maps obtained from viral DNA. The recombinant clones isolated contained viral DNA inserts which rangein size from 2.2 kb to 15.4 kb. The recombinant clones allowed to construct a physical map of the complete HSRV provirus of 12.2 kb.
KW  - Virologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61518
ER  - 
TY  - JOUR
A1  - Flügel, Rolf M.
A1  - Maurer, Bernd
A1  - Bannert, Helmut
A1  - Rethwilm, Axel
A1  - Schnitzler, Paul
A1  - Darai, Gholamreza
T1  - Nucleotide sequence analysis of a cloned DNA fragment from human cells reveals homology to retrotransposons
N2  - During molecular cloning of proviral DNA of human. spumaretroVirus, various recombinant clones were estabUshed and analyzed. Blot hybridization revealed that one of the recoinbinant plasmids bad the characteristic features of a member of the long interspersed repetitive sequences famlly. The DNA element was analyzed by restrictioil mapping and nuelootide sequencing. It showed a high degree of amino acid sequence homology of 54.3% when conipared with the 5'-terminal part of the pol gelie product of the murine retrotransposon LIMd. The 3' region of the cloned DNA element encodes proteins witb an even higher degree of homology of 67.4% in comparison to the corresponding parts of a member of the primate Kpnl sequence family.
KW  - Virologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61525
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Pikies, J.
A1  - Linoh, H.
A1  - Rohr-Aehle, R.
A1  - Gönne, S.
T1  - Sila-Procyclidin: Eine neue Synthese sowie Untersuchungen zur peripheren und zentralen anticholinergen Wirkung
N2  - Sila-Procyclidin (1 b) sowie dessen Derivate 2b (Sila-Tribexyphenidyl), 3b und 4b (Sila-Cycrimin) wurden - ausgehend von Cl\(_3\)SiCH\(_2\)Cl - durch eine neue, sechsstufige Synthese mit einer Gesamtausbeute von 16 (lb), t9 (2b), 8 (3b) bzw. 7% (4b) dar· gestellt. - Vergleichende in-vivo-Untcrsuchungen (Maus, per-osApplikation) hinsichtlich der peripheren und zentralen auticholincrgen Wirkung haben gezeigt, daß die Silicium-Verbindung 1 b dem Kohlenstoff-Analogon Ia (Procyclidin) überlegen ist.
N2  - Starting with Cl\(_3\)SiCH\(_2\)Cl. sila-procycUdine (I b) as well as its derivatives 2b (sila-trihexyphenidyl), 3b, and 4b (sila-cycrimine) were prepared by a new six-step synthesis witb a total yield of 16 (lb), 19 (2b), 8 (31) aud 7% (4b), respectively. - Comparative in vivo investigations (mice per os administration) with respect to the peripheral and centrat anticholinergic activity bavc shown that the silicon compound 1 b is advantageous over the c:arbon aualogue t a (procyclidine).
KW  - Anorganische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63815
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Linoh, H.
A1  - Ernst, L.
A1  - Moser, U.
A1  - Mutschler, E.
A1  - Sarge, S.
A1  - Cammenga, H. K.
A1  - Lambrecht, G.
T1  - Darstellung und Eigenschaften der Enantiomere der Antimuskarinika Sila-Procyclidin und Sila-Tricyclamol-iodid: Optisch aktive Silanole mit Silicium als Chiralitätszentrum
N2  - Durch Racematspaltung mit L-( + )- bzw. o-(-}-Weinsäure wurden die Enantiomere des Sila-Procyclidins (R}-1 b und (S}-1 b erhalten (>97% ce (NMR), 99.7% ee {DSC)]. Daraus wurden die Hydrochloride (R}-2b und (S)-lb und durch Umsetzung mit CH31 die Enantiomerc des Sila-Tricyclamol-iodids (R)-3b und (S}-3b [>96% ee (NMR)] hergestelll Die optisch aktiven Silanoie sind in k:ristalliner Form und in inerten Lösungsmitteln konfigurationsstabil. während sie in wässeriger Lösung raoemisieren (3 b schneller als 111). In. Analogie zur Stereoselektivität der antimuskarin. iscben Wirkung der Enantiomere der Kohlenstoff-Analoga Procyclidin (la) und Tricyclamol-iodid (3a) besitzen die (R)Enantiomere von 1 b und 311 eine größere Affinität zu den ilealen M2&- und atrialen M2ar-Muskarinrezeptorcn des Meerschwein,;, cbens als die (S)-Antipoden. Alle Silicium-Verbindungen sind stärker antiinuskarinisch wirksam als ihre Kohlenstoff-Analoga, deren Stereoselektivität jedoch stärker ausgeprägt ist. Die Unterschiede in der A1Tmität von (R}-1 b und (S)-1 b zu den ilealen und atrialen Muskarinrezeptoren bestätigen das Konzept der Heterogenität musk:arinis.cher M 2-Rezeptoren (M 2\(_\alpha\): atrialer Typ; M2\(_\beta\): ilealer Typ).
N2  - The enantiomers of sila-procyclidine (R}-1 band (S)-1 b [ > 97% ee (NMR~ 99.7% ee (DSC}] were obtained by resolution with L( + )· and o-(-)-tartaric acid. rcspectively. Starting from (R}-1 b and (S)-1 b. the hydrochlorides (R)-lla and (S)-lb wcre ptepared and thc enantiomcrs of sila-tricyclamol iodide {R)-311 and (S}-3b [>96% ee (NMR)] were syothesized by reaction witb CH31. Tbe optically active silanols show configurational stabiUty in the crystalline state and in inert solvents. whereas they racemizc in aqucous solution (3b faster tban 1 b). By analogy with the stereoselectivity of antimuscarinic action of the enantiomers of tbe carbon analogues procyclidine (la) and tricyclamol iodide (Ja), tbe t.R) enantiomers of 1b and 3b show a greater aftinity for the ileal M211 and atrial M2a _muscarinic reoeptors of the guinea pig than the corresponding (S) antipodes. AU silicon compounds e:xhibit a greater antimuscarinic potency than their carbon analogues, whercas the stereoselectivity of action is more pronounced for the carbon compounds. The difTerences in affmity for (R}-1 b and (S}l b for ileal and atrial muscarinic receptors confirm the present concept of heterogencity in muscarinic M2 rccepton (M 2\(_\alpha\): atrial type; M 2\(_beta\): ileal type).
KW  - Anorganische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63822
ER  - 
TY  - JOUR
A1  - Syldatk, C.
A1  - Andree, H.
A1  - Stoffregen, A.
A1  - Wagner, F.
A1  - Stumpf, B.
A1  - Ernst, L.
A1  - Zilch, H.
A1  - Tacke, Reinhold
T1  - Enantioselective reduction of acetyldimethylphenylsilane by Trigonopsis variabilis (DSM 70714)
N2  - Growing and resting cells of the yeast Trigonapsis variabilis (DSM 70714) can be used for the enantioselective reduction of the organosilicon compound acetyldimethylphenylsilane (J) to give optically active (R)-(1-hydroxyethyl)dimethylphenylsilane [(R)-2] in good yields. The enantiomeric purity of the isolated product was determined tobe 62-86% ee depending on the substrate concentration used. Both substrate and product caused an inhibition of the reaction at concentrations higher than 0.35 and 0.5 g/1, respectively. Besides, higher substrate and product concentrations led to increased formation of the by-product 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane. Considering the limiting substrate and product concentrations, it was possible to use the same biomass at least 5 times without significant loss of enzyme activity. 3-Methyl-3-phenyl-2-butanone (5) and acetyldimethylphenylgermane (7), which represent carbon and germanium analogues of 1, were also found to be accepted as substrates by Trigonapsis variabilis (DSM 70714). The reduction rates of the silicon {1) and germanium compound {7) were much higher than the transformation rate of the corresponding carbon analogue 5.
KW  - Anorganische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63836
ER  -