TY - JOUR
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
A1 - Skell, P.S.
T1 - Theoretical study of the potential energy surface governing the stereochemistry in ClC\(_2\)H\(_4\) reactions
N2 - Large-scale multireference configuration interaction calculations in a double·t·type AO basis including polarization functions are carried out for the potential surface of the ClC\(_2\)H\(_4\9 system. The charge distribution for various extreme points of the surface is discussed. The absolute minimum is found for an asymmetric ClC2H4 structure. The symmetrical bridged nuclear conformation is also found to be stable with respect to dissociation into Cl + C\(_2\)H\(_4\)• The activation energy for rotation about the C-C axis is calculated tobe around 18 kJ/mol, which is comparable tothat for the 1,2 migration {around 26 kJ/mol). The stereochemistry is governed by the fact that addition of CI to C\(_2\)H\(_4\) (or dissociation) is a two-step reaction proceeding through a symmetrica1 intermediate. The direct addition pathway possesses a small barrier of about 8 kJ jmol.
KW - Organische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58851
ER -
TY - JOUR
A1 - Kim, E.
A1 - Christl, Manfred
A1 - Kochl, J. K.
T1 - Charge-Transfer Cycloaddition of Homobenzvalene with Tetracyanoethylene
N2 - The transient yellow color observed in the cycloaddition of homobenzvalene (HB) with tetracyanoethylene (TCNE) is associated with the charge-transfer complex [HB, TCNE). The deliberate photoexcitation of [HB,TCNE) affords a mixture of charge-transfer cycloadducts (1, 2, and 3) that differs from that obtained in thermal cycloaddition. The relationship of {HB t TCNE•) radical-ion pair (as the critical reactive intermediate in charge-transfer cycloaddition) to the activation process for thermal cycloaddition is discussed.
KW - Organische Chemie
KW - Electron transfer
KW - photochemical
KW - Radical-ion pair
KW - Photochemistry
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58537
ER -
TY - JOUR
A1 - Kurtz, Beth E.
A1 - Schneider, Wolfgang
A1 - Carr, Martha
A1 - Borkowski, John G.
A1 - Rellinger, Elizabeth
T1 - Strategy instruction and attributional beliefs in West Germany and the United States: Do teachers foster metacognitive development?
N2 - Previous research has shown German children to be more strategic on sort-recall memory tasks than their American age-mates, and to show fewer effort-related attributions. We conducted this study to determine if those differences are due to systematic differences in the strategy instruction and attributional beliefs of German and U.S. teachers, and to explore metacognitive instructional practices in the two countries. Teachers responded to a questionnaire that inquired about their use of strategy instructions, fostering of reflective thinking in pupils, sources of children’s learning problems, and modeling of metacognitive skills such as monitoring. The second part of the questionnaire asked about the reasons underlying children’s academic successes and failures. German teachers reported more instruction of task-specific strategies, while American teachers showed more effort-related attributions. The types of strategies instructed and types of learning problems most frequently described varied across the two countries, and also according to how many years the teachers had taught. Results were discussed regarding their implications for metacognitive developmental theory, particularly regarding culture and other environmental influences on the development of controlled processing.
KW - Psychologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62145
ER -
TY - JOUR
A1 - Krämer-Neubert, Sabine
T1 - Mundart und Geschichte des Miltenberger Raumes
N2 - No abstract available
KW - Mundart
KW - Miltenberg
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73135
ER -
TY - JOUR
A1 - Epe, B.
A1 - Harttig, U.
A1 - Stopper, Helga
A1 - Metzler, M.
T1 - Covalent binding of reactive estrogen metabolites to microtubular protein as a possible mechanism of aneuploidy induction and neoplastic cell transformation
N2 - Neoplastic cell transfonnation induced by estrogens and some other carcinogen& such as benzene appears to involve the induction of mitotic aneuploidy rather than DNA damage and point mutations. As metabolic activation may also play an important roJe in the mechanism of carcinogenesis of these nongenotoxic compounds, we have studied the Interaction of reactive quinone metabolites of various estrogens and of benzene with the major microtubular protein, tubulin, in a cell-free system. Covalent binding of the radioactively labeled metabolites to the a- and 13-subunit of tubulin was found to depend on the structure of the metabolite. When the adducted tubulins were tested in vitro for their ability to polymerize to microtubules, Inhibition of microtubule assembly was obsened in every case, although to varying extents. It is proposed that the fonnation of covalent tubulin adducts may impair the formation of mitotic spindies and thus contribute to chromosomal nondisjunction and aneuploidy induction.
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63478
ER -
TY - JOUR
A1 - Pressley, Michael
A1 - Borkowski, John G.
A1 - Schneider, Wolfgang
T1 - Good information processing: What it is and how education can promote it
N2 - The nature of good information processing is outlined as determined by intact neurology, information stored in long-term memory, and general cognitive tendencies, attitudes, and styles. Educators can promote the development of good information processing by promoting what is in long-term memory. This can be accomplished by teaching important literary, scientific, and cultural knowledge; teaching strategies; motivating the acquisition and use of important conceptual knowledge and strategies; and encouraging the general tendencies supporting good information processing. Good information processing can be produced by years of appropriate educational input. Good information processors cannot be produced by short-term interventions.
KW - Psychologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62127
ER -
TY - JOUR
A1 - Merz, H.
A1 - Fliedner, A.
A1 - Lehrnbecher, T.
A1 - Sebald, Walter
A1 - Müller-Hermelink, H. K.
A1 - Feller, A. C.
T1 - Cytokine expression in B-cell non-Hodgkin lymphomas
N2 - No abstract available
KW - Biochemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62539
ER -
TY - JOUR
A1 - Liebert, U. G.
A1 - Schneider-Schaulies, Sibylle
A1 - Baczko, K.
A1 - ter Meulen, V.
T1 - Antibody-induced restriction of viral gene expression in measles encephalitis in rats
N2 - No abstract available
KW - Virologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62271
ER -
TY - JOUR
A1 - Schneider-Schaulies, Sibylle
A1 - Liebert, U. G.
A1 - Baczko, K.
A1 - ter Meulen, V.
T1 - Restricted expression of measles virus in primary rat astroglial cells
N2 - No abstract available
KW - Virologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62283
ER -
TY - JOUR
A1 - Schneider-Schaulies, Jürgen
A1 - von Brunn, A.
A1 - Schachner, M.
T1 - Recombinant peripheral myelin protein P\(_o\) confers both adhesion and neurite outgrowth promoting properties
N2 - To probe into the functional properties of the major peripheral myelin cell surface glycoprotein P 0 , its ability to confer adhesion and neurite outgrowth-promoting properfies was studied in cell culture. Tothis aim, Po was expressed as integral membrane glycoprotein at the surface of CV -1 cells with the help of a recombinant vaccinia virus expression system. Furthermore, the immunoglobulin-like extracellular domain of P0 (P0 -ED) was expressed as soluble profein in a bacterial expression system and used as substrafe coated to plastic dishes or as competitor in cell adhesion and neurite outgrowth-promoting assays. The adhesion of P0 -expressing CV-1 cells to P0 -ED substrafe was specifically inhibitable by polyclonal Po antibodies (54% :t 6% ). In addition, the specific interaction between Po molecules could be reduced ( 49% ± 8%) by adding soluble P0 -ED to the culture medium, demonstrating that the homophilic inter~ction between recombinant Po molecules can be mediated, at least on one partner of interacting molecules, by the unglycosylated Ig-like domain. Substrate-coated p -ED also conferred adhesion and neurite outgrowth ability to dorsal root ganglion neurons with neurites of a mean length of about 150 ,_..m. This neurite outgrowth was specifically inhibitable by soluble P" (74% ± 14%) and P 0 antibodies (65% ± 9% ). These observations indicate that Po is capable of displaying two different types of functional roles in the myelination process of . peripheral nerves: The heterophilic interaction with neurons may be responsible for the recognition between axon and myelinating Schwann cell at the onset of myelination, whereas the homophilic interacton may indicate its roJe in the selfrecognition of the apposing loops of Schwann cell surface membranes during the myelination process and in the mature compact myelin sheath.
KW - Immunologie
KW - immunoglobulin superfamily
KW - peripheral nervous system
KW - vaccinia virus
KW - Po
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54841
ER -
TY - JOUR
A1 - Sirén, Anna-Leena
A1 - Feuerstein, G.
T1 - Cardiovascular effects of anatoxin-a in the conscious rat
N2 - Cardiovascular Effects of Anatoxin-A in the Conscious Rat. SJREN, A.-L., AND FEUERSTEIN, G. (1990). Toxicol. Appl. Pharmacol. 102,91-100. The effects ofanatoxin-A on mean arterial pressure (MAP), heart rate, cardiac index (CI), and blood flow (BF) in hindquarter (HQ), renal (R). and mesenteric (M) vascular beds were studied after intravenous (iv) and intracerebroventricular (icv) administration in the conscious rat. The pharmacological profile of anatoxin-A was further compared to nicotine administered iv and icv. MAP and heart rate were measured from femoral artery, CI by thermodilution method, and blood flow by Doppler velocimetry. Anatoxin-A and nicotine (30, 100 and 300 1-!g/kg iv) produced an increase in MAP with concomitant bradycardia. The highest doses increased Cl. MBF and RBF decreased due to a vasoconstriction in M and R vasculature. These effects were attenuated by the ganglion blocker chlorisondamine (5 mg/kg, iv). Anatoxin-A ( 100 1-!g/k~ iv) increased plasma epinephrine Ievels by 2- fold with virtually no effect on norepinephrine whereas nicotine ( 100 ~oLg/kg, iv) increased plasma epinephrine and norepinephrine by 20- to 30-fold. Central administration of anatoxin-A and nicotine (30-100 ,ug/kg icv) increased MAP with no effect on heart rate and produced M and R vasoconstriction. In summary, the present study demonstrates that anatoxin-A acts as a nicotinic cholinergic agonist in the c.onscious rat after both systemic and centrat administration. Anatoxin-A and nicotine produced pressor and reno-splanchnic vasoconstrictor responses and at high doses increased cardiac output. These effects were mediated by activation ofthe nicotinic receptors in the adrenal medulla and sympathetic ganglia. However, marked differences were found in the potency ofanatoxin-A versus nicotine to stimulate the sympathoadrenomedullary axis.
KW - Neurobiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63103
ER -
TY - JOUR
A1 - Paakkari, P.
A1 - Paakkari, I.
A1 - Sirén, Anna-Leena
A1 - Feuerstein, G.
T1 - Respiratory and locomotor stimulation by low doses of dermorphin - a Mu\(_1\)-receptor mediated effect
N2 - The selective opioid mu receptor agonist dermorphin increased the locomotor activity of rats dose dependently at 1 0 to 1 00 pmol/kg i.c.v. Respiratory rate, relative tidal volume and respiratory minute volume also increased unrelated to changes in locomotor activity. Higher doses, on the other hand, produced catalepsy and respiratory depression. Pretreatment of the rats with the mu,-selective antagonist naloxonazine (10 mg/kg i.v.) blocked the stimulant locomotor and respiratory effects of low doses of dermorphin (1 0--1 00 pmol/kg), but potentiated the respiratory depressant effect of a high dose (1 0 nmol/kg) of dermorphin. The selective benzodiazepine antagonist flumazenil (5 mg/kg), which has been shown previously to antagonize catalepsy and respiratory depression produced by relatively high doses of dermorphin, did not antagonize the respiratory or locomotor stimulant effect of dermorphin. The data suggest that mu\(_1\)-opioid receptors are responsible for the low dose stimulant effects of dermorphin on locomotor activity and respiration whereas mu\(_2\) receptors mediate the respiratory depressant effect of dermorphin.
KW - Neurobiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63110
ER -
TY - JOUR
A1 - Sodian, Beate
A1 - Schneider, Wolfgang
T1 - Children's understanding of cognitive cueing: How to manipulate cues to fool a competitor
N2 - 4-6-year-old children's understanding of cognitive cuing was studied in 2 experiments using a strategic interaction paradigm. Ghildren could fool a competitor by hiding targets in locations that were labeled with semantically weakly associated cues and help a cooperative partner by hiding them in semantically highly associated locations. Very few 4-year-olds, half the 5-year-olds, and almost all 6-year-olds appropriately chose semantically highly vs. weakly associated hiding places to make the targets easy vs. difficult to find. The second experiment showed that 4-year-olds did not strategically manipulate cues as sources of information, although they themselves proficiently used them as such in a search task. These findings are discussed with regard to research on children's developing understanding of origins of knowledge and belief and with regard to recent claims that young preschoolers possess a metacognitive understanding of cognitive cuing.
KW - Psychologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62132
ER -
TY - JOUR
A1 - Oeschger, Bernhard
A1 - Fackler, Guido
A1 - Hamer, Jens
A1 - Burkhard, Antje
T1 - Die Landesstelle für Volkskunde Freiburg 1960-1990
N2 - No abstract available
KW - Volkskunde
KW - Freiburg
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41796
ER -
TY - JOUR
A1 - Fiala, Brigitte
T1 - Extrafloral nectaries versus ant-Homoptera mutualisms : a comment on Becerra and Venable
N2 - No abstract available
KW - Nektarium
KW - Ameise
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32948
ER -
TY - JOUR
A1 - Künzler, Jan
T1 - Familiale Arbeitsteilung bei Studierenden mit Kleinkindern : Erste Ergebnisse einer Zeitbudgetstudie
N2 - Gerade bei jungen Frauen und Männern mit hohem Bildungsniveau haben sich in den letzten Jahren die Einstellungen zur familialen Arbeitsteilung stark gewandelt. Mittlerweile wird eine partnerschaftlieh- egalitäre Verteilung der Pflichten im Haushalt mehrheitlich begrüßt. Um festzustellen, ob veränderte Einstellun· gen auch verhaltenswirksam geworden sind, wurden 66 Studentinnen und Studenten mit Kleinkindern mit Methoden der Zeitbudgetforschung zu Tagesablauf und Zeitverwendung befragt. Bei insgesamt im Vergleich zur Erwerbsbevöl· kerung hoher Gesamtbelastung waren auch hier Hausarbeit und Kinderbetreuung ungleich, und zwar zu Lasten der Frauen, verteilt. Studentinnen können daher wesentlich weniger Zeit in ihr Studium investieren als Studenten. Immerhin hatte eine relativ große Minderheit partnerschaftliehe Formen der Arbeitsteilung verwirklicht.
KW - Soziologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-50752
ER -
TY - JOUR
A1 - Wieber, M.
A1 - Walz, J.
A1 - Burschka, Christian
T1 - Organostibonsäureester. II [1]: Darstellung und Eigenschaften von Methanstibonsäureestern. Struktur von Di-μ-methoxy-bis[dibromo-methoxy-methyl-antimon(V)]
N2 - Dimere alkoxyverbrückte Verbindungen des Typs [CH\(_3\)SbX\(_2\)(OR)(μ-OR)]\(_2\) (X = Cl, Br; R = CH\(_3\), C\(_2\)H\(_5\)) können durch Oxidation von CH\(_3\)Sb(OR)\(_2\) mit Br\(_2\) oder S0\(_2\)Cl\(_2\) in CH\(_2\)Cl\(_2\) unterhalb -60°C als lichtempfindliche kristalline Feststoffe erhalten werden. Die Struktur der Verbindung [CH\(_3\)SbBr\(_2\)(OCH\(_3\))(μ-OCH\(_3\))]\(_2\) konnte mittels Röntgenstrukturanalyse bestimmt werden. Umsetzungen mit Natriumalkoholaten in den entsprechenden Alkoholen bei 0°C führen zu dimeren Tetraalkoxymethylstiboranen. Austauschreaktionen von Tetramethoxymethylstiboran mit Ethanol ergeben das Ethoxyderivat und mit Diolen symmetrische spirocyclische Methanstibonsäureester.
N2 - Dimeric alkoxy-bridged compounds of the type [CH\(_3\)SbX\(_2\)(OR)(μ-OR)]\(_2\) (X = Cl, Br; R = CH\(_3\), C\(_2\)H\(_5\)) are prepared by oxidation of CH\(_3\)Sb(OR)\(_2\) with Br\(_2\) or S0\(_2\)Cl\(_2\) in CH\(_2\)Cl\(_2\) below -60°C as light sensitive erystals. The structure of [CH\(_3\)SbBr\(_2\)(OCH\(_3\))(μ-OCH\(_3\))]\(_2\) was determined by X-Ray analysis. By reaction with sodium alkoxides in the corresponding alcohol at 0°C dimeric tetraalkoxymethylstiboranes are obtained. Exchange reactions of tetramethoxymethylstiborane with ethanol give the ethoxy derivative and with diols symmetrie spirocyclic esters of methanestibonic acid.
KW - Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31909
ER -
TY - JOUR
A1 - Wieber, M.
A1 - Hoehl, H.
A1 - Burschka, Christian
T1 - Diphenylantimonalkoxide und -thiolate als Liganden in Metallcarbonylkomplexen des Chroms und Molybdäns; Kristallstruktur von Tris[diphenyl(phenylthiolato)stiban]molybdäntricarbonyl
T1 - Diphenylantimony Alkoxides and Thiolates as Ligands in Carbonyl Complexes of Chromium and Molybdenum; Crystal Structure of Tris [diphenyl(phenylthiolato)stibane] Molybdenum Tricarbonyl
N2 - Diorganoantimonverbindungen R\(_2\)SbX (R = C\(_6\)H\(_5\) X = S-Organyl, O-Organyl) reagieren mit Cycloheptatrienylmolybdäntricarbonyl zu Produkten des Typs [R\(_2\)SbX]\(_3\)Mo(CO)\(_3\). Die analogen Komplexe des Chroms können durch Reaktion von Tris(acetonitril) chromtricarbonyl mit den Antimon-Liganden dargestellt werden. (1,5-Cyclooctadien)molybdäntetracarbonyl reagiert unter Substitution mit Diorganoantimonderivaten R\(_2\)SbX (R = C\(_6\)R\(_5\), X = S-Organyl) zu den Verbindungen [R\(_2\)SbX]\(_2\)Mo(CO)\(_4\) Synthese und Eigenschaften der StibanKomplexe sowie die Kristallstruktur der Verbindung [(C\(_6\)H\(_5\))\(_2\)SbSC\(_6\)H\(_5\)]\(_3\)Mo(CO)\(_3\) werden beschrieben.
N2 - Diorganoantimony compounds R\(_2\)SbX (R = C\(_6\)H\(_5\), X = S-organyl, O-organyl) react with cycloheptatrienemolybdenum tricarbonyl to yield products of the type [R\(_2\)SbX]\(_3\)Mo(CO)\(_3\). Analogous complexes of chromium are prepared by reaction oftris(acetonitrile)chromium tricarbonyl with the stibane Ugands. Tetracarbonyl-l,5-cyclooctadienemolybdenum undergoes substitution reaction with diorganoantimony compounds R\(_2\)SbX (R = C\(_6\)R\(_5\), X = S-organyl) to give [R\(_2\)SbX]\(_2\)Mo(CO)\(_4\) Synthesis and properties of the stibane complexes as weil as an X-ray determination of [(C\(_6\)H\(_5\))\(_2\)SbSC\(_6\)H\(_5\)]\(_3\)Mo(CO)\(_3\) are described.
KW - Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31919
ER -
TY - CHAP
A1 - Wehgartner, Irma
T1 - Bemerkungen zum Bild der Frau in der etruskischen Kunst
N2 - No abstract available
KW - Etrusker
KW - Kunst
KW - Frau
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53444
ER -
TY - JOUR
A1 - Sponholz, Barbara
T1 - Sedimentologische Untersuchungen an Verfüllungen von Silikatkarstformen im Djado und an der Stufe von Bilma (NE-Niger)
N2 - Vorstellung eines durch die Jubiläumsstiftung der Universität Würzburg geförderten Forschungsvorhabens
KW - Geographie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56650
ER -
TY - JOUR
A1 - Bogdan, Christian
A1 - Moll, Heidrun
A1 - Solbach, Werner
A1 - Röllinghoff, Martin
T1 - Tumor necrosis factor-\(\alpha\) in combination with interferon-\(\gamma\), but not with interleukin 4 activates murine macrophages for elimination of Leishmania major amastigotes
N2 - We have previously shown that during an infection with Leishmania major, susceptible BALB/c mice, as opposed to mice of a resistant strain (C57BLl6), are primed by lipopolysaccharide for the production of high levels of tumor necrosis factor-\(\alpha\) (TNF-\(\alpha\)) which is known to be a potent maerophage M\(\Phi\) stimulator in other parasitic diseases. In the present study we investigated whether TNF-\(\alpha\) activates M\(\Phi\) for killing of L. major parasites. In the absence of interferon-y (IFN-\(\gamma\)) or lipopolysaccharide, TNF-\(\alpha\) (0.025-25000 U/ml) failed to activate peritoneal exudate M\(\Phi\) from BALB/c mice for killling of L. major amastigotes. In the presence of suboptimal doses of IFN-\(\gamma\) (5 or 10 Vlml), however, TNF-\(\alpha\) mediated a rapid elimination of intracellular parasites, which was highly significant compared to IFN-\(\gamma\) alone. Tbe combination of TNF with interleukin 4, in contrast, was inactive in this respect and allowed survival of intracellular parasites. From these data we conelude that the presence of IFN-\(\gamma\) is crucial for TNF-\(\alpha\)-mediated killing of L. major parasites by M\(\Phi\). Disease progression in susceptible mice therefore seems to be a consequence of a deficiency of IFN-\(\gamma\) and a predominance of interleukin 4 rather than the result of an excess amount of TNF-\(\alpha\).
KW - Infektionsbiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31614
VL - 20
SP - 1131
EP - 1135
ER -
TY - CHAP
A1 - Hagedorn, Horst
A1 - Sponholz, Barbara
T1 - Silikatkarst in Nord- und Ostniger - Einbindung der Verkarstung in die tertiäre und quartäre Landschaftsgeschichte
N2 - Im Nordosten der Republik Niger sind Karstformen in Sandsteinen, Silcretes, Eisenkrusten und im Kristallin weit verbreitet. Aufgrund geomorphologischer Untersuchungen und mikromorphologischer Analysen läßt sich eine echte Verkarstung im Sinne lösungsbedingter Reliefformung nachweisen. Untersuchungen an Dünnschliffen und rasterelektronenmikroskopische Analysen von Quarzkomoberflächen zeigen extrem starke Kornkorrosion in den äußeren Probenbereichen (Wandungen von Karstformen) und allgemein starke Spuren von Kieselsäuremobilisierung. Die Ausfällung von Kieselsäure auf den Quarzkörnern kann bis zur Neukristallisation von Quarz reichen (Djado, Stufe von Bilma) oder nur als amorpher Überzug ausgebildet sein (Massive von Tennit und Koutous). Die Gesamtheit der Befunde deutet auf eine Hauptphase der Verkarstung im frühen Tertiär hin, die von weiteren Lösungsphasen im jüngeren Tertiär und wahrscheinlich auch im Quartär gefolgt wird. Die jeweils über weite Räume ähnlichen Befunde lassen eine Abhängigkeit des Verkarstungsgeschehens von den paläoklimatischen Bedingungen vermuten; vor allem durch die Ausbildung eines unterirdischen Entwässernngs- und Hohlraumsystems sind enge Wechselbeziehungen zwischen Karstformenschatz und der Entwicklung der übrigen Reliefelemente gegeben.
N2 - In the northeastem part of the Republic of Niger karstic features in sandstones, silcretes, ironcrusts and cristalline rocks occur very commonly. On the base of geomorphological field studies and micromorphological analyses real karst forming caused by rock dissolution is verified. Analyses of thin sections and scanning electron microscopy of quartz grain surfaces show extreme corrosion in the exterior parts of the samples and an important mobilisation of silica. Precipitation of silica on quartz grains may reach the state of recristallisation of quartz (Djado, cuesta of Bilma) or of only amorpheous silica coatings (massifs of Tennit and Koutous). The results indicate a main period of karst formation du ring early Tertiary, followed by others du ring late Tertiary and Quaternary. The widespread distribution of similar results indicates the dependence of karstification on palaeoclimatic conditions; the subterranean drainage and cave systems cause a significant dependence between karst and the development of other landforms.
KW - Geographie
KW - Niger
KW - Karst
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56597
ER -
TY - JOUR
A1 - Kleinhans, Martha
T1 - L'enfant sage à trois ans - Vom mittelalterlichen Dialog zum Volksbuch
N2 - No abstract available
KW - Romanistik
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54201
ER -
TY - JOUR
A1 - Fiala, Brigitte
T1 - Bäume & Ameisen : Partnerschaften im südostasiatischen Regenwald
N2 - No abstract available
KW - Baum
KW - Ameisen
KW - Regenwald
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54741
ER -
TY - JOUR
A1 - Vonhof, S.
A1 - Sirén, Anna-Leena
A1 - Feuerstein, Giora
T1 - Volume-dependent spatial distribution of microinjected thyrotropin-releasing hormone (TRH) into the medial preoptic nucleus of the rat
N2 - The present study was performed to qua ntify the distribution of a peptide neurotransmitter after microinjection into the medial preoptic area (POM), using a technique suitable for conscious animal preparations. The results indicate that only 50-ni volumes of injected tracer were sufficiently localized with 77 ± 9% recovery in the POM. Injections of higher volumes resulted in an increasing spread of tracer into distant anatomical regions and structures, including the needle tract and cerebral ventricles. The amount of tracer localized in the POM decreased to 38±4% (200 nl) (P < 0.05) and 41 ±8% (500 nl) (P <0.05), respectively. The data suggest that the volume of injection is critical for intraparenchymal injections into structures of a diameter of I mm or less, such as the POM and should not exceed 50 nl in conscious animal preparations.
KW - Neurophysiologie
KW - Neurobiologie
KW - Autoradiography
KW - Microinjection
KW - Hypothalamus
KW - TRH
KW - Neuropeptides
KW - [3H][3Me-His2]-TRH
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47421
ER -
TY - JOUR
A1 - Shuaib, A.
A1 - Xu, K.
A1 - Crain, B.
A1 - Sirén, Anna-Leena
A1 - Feuerstein, Giora
A1 - Hallenbeck, J.
A1 - Davis, JN
T1 - Assessment of damage from implantation of microdialysis probes in the rat hippocampus with silver degeneration staining
N2 - We used a sensitive silver degeneration staining method to study the effects of insertion of microdialysis probes in rat dorsal hippocampus and neocortex. Nine animals were sacrificed 24 h, 3 days or 7 days after implantation of dialysis tubing. Although mild neuronal cell death and small petechial hemorrhages were seen in elose proximity to the implantation site, the striking finding was the presence of degenerating axons both adjacent to the implantation site and in remote sites such as the corpus callosum and contralateral hippocampus. The observed changes could alter brain function near or remote from the implantation site and should be considered in analysis of dialysis experiments.
KW - Neurophysiologie
KW - Neurobiologie
KW - In-vivo dia lysis
KW - Silver degeneration staining
KW - Axonal degeneration
KW - Rat hippocampus
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47433
ER -
TY - JOUR
A1 - Künzler, Jan
T1 - Interpenetration bei Parsons und Luhmann : Von der Integration zur Produktion von Unordnung
T1 - Parsons and Luhmann on interpenetration : From integration to the production of disorder
N2 - Talcott Parsons hatte den Interpenetrationsbegriff eingeführt, um strukturelle Beziehungen zwischen verschiedenen System arten erfassen zu können. Niklas Luhmann übernimmt den Begriff von Parsons und benutzt ihn nach weitreichenden Revisionen v. a. dazu, das Verhältnis von psychischen und sozialen Systemen auf den Begriff zu bringen. In dieser Intersystembeziehung spielt Sprache eine entscheidende Rolle. Ein systemtheoretisches Sprachkonzept, das dieser Vermittlungsleistung Rechnung trägt, steht jedoch noch aus; ein zentrales Desiderat dabei ist, den Widerspruch zwischen Sprache als systemübergreifender Vermittlungsinstanz und der autopoietischen Geschlossenheit von Systemen aufzulösen.
N2 - Talcott Parsons introduced the concept of interpenetration in order to explain the structural relations between different types of systems. Niklas Luhmann adopts a revised version of Parsons' concept in order to conceptualize especially the relations between personal and social systems. Language plays an important part in this relation. The sociological systems theory has not as yet worked out a theory of language which takes this mediatory function into account. There seems to be a contradiction between language mediating the relations of systems and the closed autopoietic reproduction of those systems.
KW - Familientherapie
KW - Systemische Therapie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-51112
ER -
TY - JOUR
A1 - Waaga, AM
A1 - Ulrichs, Karin
A1 - Krzymanski, M.
A1 - Treumer, J.
A1 - Hansmann, ML
A1 - Rommel, T.
A1 - Müller-Ruchholz, W.
T1 - The immunosuppressive agent 15-deoxyspergualin induces tolerance and modulates MHC-antigen expression and interleukin-1 production in the early phase of rat allograft responses
N2 - No abstract available
KW - Chirurgie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45253
ER -
TY - JOUR
A1 - Ulrichs, Karin
A1 - Winoto-Morbach, S.
A1 - Hering, B.
A1 - Müller-Ruchholtz, W.
T1 - A Useful Biotechnological Approach to Solve the Problem of Graft Purity in Human Pancreatic Islet Transplantation
N2 - No abstract available
KW - Chirurgie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45619
ER -
TY - JOUR
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, W.
T1 - Mixed lymphocyte islet culture (MLIC) and its use in manipulation of human islet alloimmunogenicity
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45515
ER -
TY - JOUR
A1 - Engemann, R.
A1 - Ulrichs, Karin
A1 - Thiede, A.
A1 - Müller-Ruchholtz, W.
A1 - Hamelmann, H.
T1 - Value of a physiological liver transplant model in rats. Induction of specific graft tolerance in a fully allogeneic strain combination
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45622
ER -
TY - JOUR
A1 - Schenk, Wolfdieter A.
A1 - Khadra, Almuetassem
A1 - Burschka, Christian
T1 - Schwefel(IV)-Verbindungen als Liganden: XII. Ringöffnung von Thiiran-1-oxid, Struktur des intermediären Lewis-Säure-Addukts
N2 - No abstract available
KW - Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46641
ER -
TY - JOUR
A1 - Schlatter, J.
A1 - Lutz, Werner K.
T1 - The carcinogenic potential of ethyl carbamate (urethane): risk assessment at human dietary exposure levels
N2 - Ethyl carbamate is found in fermented foods: bread contains 3-15 ng/g, stone-fruit brandies 200-20,000 ngfg, and about one-third of table-wine samples analysed contained more than 10 ng/g. In animals, ethyl carbamate is degraded to C02, H20 and NH3, with intermediate formation ofethanol. This degradation has been shown tobe inhibited (postponed) in the mouse by ethanol concentrations in the blood of about 0.15% and higher. A quantitatively minor pathway involves a two-step oxidation of the ethyl group to vinyl carbamate and epoxyethyl carbamate, the postulated electrophilic moiety that reacts with DNA. This reaction is probably the mode of the mutagenic action observed in many cellular and animal systems. The fact that only vinyl carbamate, but not ethyl carbamate, is mutagenic in a standard Ames test is probably because there is insufficient production of the intermediate oxidation product in the standard test. Consistent with this metabolism is the carcinogenic activity of ethyl carbamate in various animal species and in different organs; this activity can be seen even after a single high dose in early life. Quantitative analysis of the total tumour incidences after chronic exposure of rats and mice to 0.1-12.5 mg ethyl carbamate/kg body weightjday in the drinking-water showed a dose-related increase. The main target organs were the mammary gland (female rats and mice having similar susceptibilities) and the Jung (mice only). On the basis of sex- and organ-specific tumour data and with a linear extrapolation to a negligible increase of the lifetime tumour incidence by 0.0001% ( one additional tumour in one milüon individuals exposed for life), a "virtually safe dose .. of 20 to 80 ng/kg body weight/day was estimated. The daily burden reached under normal dietary habits without alcoholic beverages is in the range of about 20 ng/kg body weightfday. Regular table-wine consumption would increase the risk by a factor of up to five. Regular drinking of 20 to 40 ml stone-fruit brandy per day could raise the calculated lifetime tumour risk to near 0.01%.
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60826
ER -
TY - JOUR
A1 - Buss, P.
A1 - Caviezel, M.
A1 - Lutz, Werner K.
T1 - Linear dose-response relationship for DNA adducts in rat liver from chronic exposure to aflatoxin B1
N2 - Male F-344 rats were given eH]aßatoxin B1 (AFB1) in the drinking water at three exposure Ievels (0.02, 0.6, 20 J,Lgll, resulting in average dose Ievels of 2.2, 73, 2110 nglkg per day). After 4, 6 and 8 weeks, DNA was ~ted frorn the livers and analyzed for aßatoxin-DNA adducts. Tbe Ievel of DNA adducts did not increase significantly after 4 weeks, indicating that a steady-state for adduct formation and removal had nearly been reached. At 8 weeks, the adduct Ievels were 0.91, 32 and 850 nucleotide-aßatoxin adducts per to' nucleotides, i.e. clearly proportional to the dose. At the high dose Ievel, a near SO% tumor incidence would be expected in a 2-year bioassay with F -344 rats while the low dose used is within the range of estlmated human dietary exposures to aßatoxin in W estem countries. The proportionality seen between exposure and steady-state DNA adduct Ievel is discussed with respect to a linear extrapolation of the tumor risk to low dose.
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60779
ER -
TY - JOUR
A1 - Lutz, Werner K.
T1 - Dose-response relationship and low dose extrapolation in chemical carcinogenesis [commentary]
N2 - Data supporting various dose-respome relationships in chemical carcinogenesis are summarized. General principles are derived to explain the relationships between exposure dose, JI>NA adduct Ievel, induction of genetic changes, and tumor incidence. Some mechanistic aspects of epigenetic carcinogens (stimulation of ceU division and maldlfl'erentlation) are analyzed in a similar way. In a bomogeneous pnpulation, non-linearities are frequent. They are due to pbenomena of induction or saturation of enzymatic activities and to the multi-step nature of carcinog~: if a carcinogen acce1erates more than one step, the SUperposition of the dose- response curves for the indJvidual steps can result in an exponential relationship. A fourth power of the dose was the maximum seen in animals (fonnaldehyde). At the lowest dose Ievels, a proportionality between dose and tumor induction is postulated independent of the mechanism of action if the carcinogen aceeierotes the endogenous proass responsible for spootaneous tumor formation. Low-dose thresholds are expected only for situations where the carcinogen acts in a way that has no endogenous counterpart. Epidemiologfcal studies in humans show linear dose- response curves in all but two investigations. The difference from the strongly nonlinear slopes ·seen in animal studies could be due to the heterogeneity of the human population: if the individual sensitivity to a carcinogen is governed by a large number of genetic and Iife-style factors, the non-linea.rities will tend to cancel each other out and the dose- response curve becomes 'quasi-linear'.
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60789
ER -
TY - JOUR
A1 - Hegi, M. E.
A1 - Ulrich, D.
A1 - Sagelsdorff, P.
A1 - Richter, C.
A1 - Lutz, Werner K.
T1 - No measurable increase in thymidine glycol or 8-hydroxydeoxyguanosine in liver DNA of rats treated with nafenopin or choline-devoid low-methionine diet
N2 - Male rats were treated for 2 months with 1000 ppm nafenopin in the diet or for 4 or 7 days with a choline-devoid low-methionine diet. DNA was isolated from the livers and analyzed for the presence of cis-thymidine glycol-3'-phosphate (cis-dTGp) by 32P-postlabeling and for the Ievel of 8-hydroxy-deoxyguanosine (8-0H-dG) by electrochemical detection (ECD). In no DNA sample was the Ievel of cis-dTGp above the Iimit of detection of 1 modified thymidine per 106 nucleotides. With 8-0H-dG, a background Ievel of this modification of 20 8-0H-dG per 106 nucleosides was found in liver DNA of control rats, which was not affected by either treatment. It is postulated for thymidine glycol that a potential increase was below the Iimit of detection or was rapidly repaired in vivo and that the steady-state Ievel of endogenous 8-hydroxydeoxyguanosine appears not tobe influenced by the treatments chosen.
KW - Toxikologie
KW - Oxygen radical
KW - DNA
KW - Genotoxicity
KW - Rat liver peroxisome
KW - Choline deficiency
KW - Thymidine glycol
KW - 8-Hydroxy-deoxyguanosine
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60790
ER -
TY - JOUR
A1 - Meier, I.
A1 - Shephard, S. E.
A1 - Lutz, Werner K.
T1 - Nitrosation of aspartic acid, aspartame, and glycine ethylester. Alkylation of 4-(p-nitrobenzyl)pyridine (NBP) in vitro and binding to DNA in the rat
N2 - In a colorimetric assay using 4-( p-nitrobenzyl)pyridine (NBP) as a nucleophilic scavenger of alkylating agents, the nitrosation and alkylation reactions were investigated for a number of amino acids and derivatives. The alkylating activity increased with the square of the nitrite concentration. The nitrosation rate constants for aspartic acid, aspartame, and glycine ethylester ( = precursors C) were 0.08, 1.4 and ~ 0.2, respectively, expressed in terms of the pH-dependent \(k_2\) rate constant of the equation dNOCjdt = \(k_2\) • (C]· [nitrite]\(^2\) • The rates correlated inversely with the basicity of the amino group. The stability of the alkylating activity was astonishingly high, both in acid and at neutral pH. Half-lives of 500, 200, and 30 min were determined for aspartic acid (pH 3.5), aspartame (pH 2.5), and glycine ethylester (pH 2.5). Values of 60, 15, and 2 min; respectively, were found at pH 7. It is concluded that rearrangement of the primary N-nitroso product to the ultimate alkylating agent could be rate-limiting. The potential of nitrosated a-amino acids to bind to DN A in vivo was investigated by oral gavage of radiolabelled glycine ethylester to rats, followed irnmediately by sodium nitrite. DNA was isolated from stomach and liver and analysed for radioactivity and modified nucleotides. No indication of DNA adduct formation was obtained. Based on an estimation of the dose fraction converted from glycine ethylester to the nitroso product under the given experimental conditions, the maximum possible DNA-binding potency of nitroso glycine ethylester is about one order of magnitude below the methylating potency of N-nitrosomethylurea in rat stomach. The apparent discrepancy to the in vitro data could be due to efficient detoxification processes in mammalian cells.
KW - Toxikologie
KW - Nitrosation
KW - Alkylation
KW - Amino acids
KW - DNA binding
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60804
ER -
TY - JOUR
A1 - Lutz, Werner K.
T1 - Endogenous genotoxic agents and processes as a basis of spontaneous carcinogenesis
N2 - A list ofendogenaus DNA·damaging agents and processes is given. Endogenaus e/ectrophiles are found with the cosubstrates of physiological transfer reactions (S-adenosylrnethionine for methylation, A TP for phosphorylation, NAD\(^+\) for ADP-ribosylation, acetyl CoA for acetylation). Aldehyde groups (glyceraldehyde- 3-phosphate, formaldehyde, open forms of reducing sugars, degradation products of peroxidation) or alkylating degradation products derived from endogenaus nitrose compounds represent additional possibilities. Radical-forming reactions include leakage of the superoxide anion radical from terminal cytochromes and redox cycles, hydroxyl radical formation by the Fenton reaction from endogenaus hydrogen peroxide, and the formation of lipid peroxides. Genetic instability by spontaneaus deaminations and depurinations as well as replicative instability by tautomer errors andin the presence of mutagenic metal ions represent a third important dass of endogenaus genotoxic processes. The postulated endogenaus genotoxicity could form the mechanistic basis for what is called 'spontaneous' tumor incidence and explain the possibility of an increased tumor incidence after treatment of animals with non-genotoxic compounds exhibiting tumor-promoting activity only. Individual differences are expected to be seen also with endogenaus DNA damage. The presence of endogenaus DNA darnage implies that exogenaus DNAcarcinogen adducts give rise to an incremental darnage which is expected to be proportional to the carcinogen dose at lowest Ievels. An increased tumor risk due to exposure to exogenaus genotoxic carcinogens could therefore be assessed in terms of the background DNA damage~ for instance in multiples of the mean Ievel or of the interindividual variability in a population.
KW - Toxikologie
KW - Endogenous genotoxicity
KW - Electrophiles
KW - Radicals
KW - Genetic instability
KW - DNA damage
KW - Spontaneous tumours
KW - Carcinogen risk Individual susceptibili
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60816
ER -
TY - JOUR
A1 - Moll, Heidrun
A1 - Binöder, Kerstin
A1 - Bogdan, Christian
A1 - Solbach, Werner
A1 - Röllinghoff, Martin
T1 - Production of tumour necrosis factor during murine cutaneous leishmaniasis
N2 - We have assessed the role of tumour necrosis factor-a (TNF) during cutaneous leishmaniasis and demonstrated that significant levels of TNF were released by spleen cells from infected mice after in cirro restimulation with Leishmania major promastigotes. Spleen cells from both genetically resistant and genetically susceptible mice were equally capable of producing TNF. After challenge with bacterial endotoxin, TNF activity could also be demonstrated in the serum of L. mujor-infected mice and the titres correlated with the course of cutaneous disease in susceptible and resistant mice. TNF did not exert a direct leishmanicidal effect in uitro. Furthermore, our study indicated that macrophages are the source of L. major-induced TNF activity and that its elicitation is dependent on the presence of T cells. These findings suggest that TNF acts in concert with other cytokines produced during L. major infection and that its role depends on the composition of T cell subsets and cytokines present.
KW - Immunologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61291
ER -
TY - JOUR
A1 - Moll, Heidrun
A1 - Röllinghoff, Martin
T1 - Resistance to murine cutaneous leishmaniasis is mediated by T\(_H\)1 cells, but disease-promoting CD4\(^+\) cells are different from T\(_H\)2 cells
N2 - No abstract available
KW - Biologie
KW - Immunologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61305
ER -
TY - JOUR
A1 - Schartl, Manfred
T1 - Homology of melanoma-inducing loci in the genus Xiphophorus
N2 - Several species of the genus Xiphophorus are polymorphic for specific pigment patterns. Same of these give rise to malignant melanoma following the appropriate crossings. For one of these pattern Iod from the platyfish Xiphophorus maculatus the melanoma-inducing gene has been doned and found to encode a novel receptor tyrosine kinase, designated Xmrk. Using molecular probes from this gene in Southern blot analyses on single fish DNA preparations from 600 specimens of different populations of various species of the genus Xiphophorus and their hybrids, either with or without melanomapredisposing pattern, it was shown that all individuals contain the Xmrk gene as a proto-oncogene. It is located on the sex chromosome. All fish that carry a melanoma-predisposing locus which has been identified by Mendelian genetics contain an additional copy of Xmrk, closely linked to a specific melanophore pattern locus on the sex chromosome. The melanoma-inducing loci of the different species and populations are homologous. The additional copy of Xmrk obviously arose by a geneduplication event, thereby acquiring the oncogenic potential. The homology of the melanomainducing Iod points to a similar mechanism of tumor suppression in all feral fish populations of the different species of the genus Xiphophorus.
KW - Physiologische Chemie
KW - Xiphophorus
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61757
ER -
TY - JOUR
A1 - Dracopoli, Nicholas C.
A1 - Feltquate, David M.
A1 - Sam, Brigitta
A1 - Schartl, Manfred
T1 - Taql and Mspl RFLPs are detected by the human 2,3-biphosphoglycerate mutase (BPGM) cDNA
N2 - No abstract available
KW - Physiologische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61763
ER -
TY - JOUR
A1 - Friedenreich, Hildegard
A1 - Schartl, Manfred
T1 - Transient expression directed by homologous and heterologous promoter and enhancer sequences in fish cells
N2 - ln order to construct fish specific expression vectors for studies on gene regulation in vitro and in vivo a variety of heterologous enhancers and promoters from mammals and from viruses of higher vertebrate cells were tested for expression of the bacterial chloramphenicol acetyl transferase reporter gene in three teleost fish cell lines. Several viral enhancers were found to be constitutively active at high Ieveis. The human metallothionein promoter showed inducible expression in the presence of heavy metal Ions. A fish sequence was isolated that can be used as a homologous constitutively active promoter for expression of foreign genes. Using the human growth hormone gene with an active promoter in fish cells for transient expression insufficient splicing and Iack of translation were observed, pointing to limitations in the use of heterologous genes in gene transfer experiments. On the contrary, some heterologous promoters and enhancers functioned in fish c as weil as in their cell type of origin, indicating t at corresponding transcription factors are sufficient conserved between fish and human over a period of 900 million years of Independent evolution.
KW - Physiologische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61774
ER -
TY - JOUR
A1 - Clauss, Gerd
A1 - Winkler, Christoph
A1 - Lohmeyer, Jürgen
A1 - Anders, Fritz
A1 - Schartl, Manfred
T1 - Oncofetal antigen in Xiphophorus detected by monoclonal antibodies directed against melanoma-associated antigens
N2 - Monoclonal antlbodies (MAbs) directed against Xiphophorus melanoma cells were deve(oped and tested by lndirect immunofluorescence and Immunoperoxidase staining for reactivity with a panel of I 5 allogeneic tissues and 12 allogeneic cell llnes. The reactivity of such MAbs was restricted to melanoma cells from tumor biopsies and melanoma-derived cell lines. ln addition, all embryonie cells of all histiotypes from developmental stages later than mld·organogenesis and from corresponding short term in vitro cultures reacted with these MAbs. ln contrast, normal tissues and organs from adult fish dlsplayed no reactivity, thus implying that the melanoma-associated antigens detected by the MAbs described are oncofetal antigens.
KW - Physiologische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61784
ER -
TY - JOUR
A1 - Gross, E.
A1 - Ruzicka, T.
A1 - Restorff, B. von
A1 - Stolz, W.
A1 - Klotz, Karl-Norbert
T1 - High-affinity binding and lack of growth-promoting activity of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) in a human epidermal cell line
N2 - No abstract available
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60358
ER -
TY - JOUR
A1 - Klotz, Karl-Norbert
A1 - Keil, R.
A1 - Zimmer, F. J.
A1 - Schwabe, U.
T1 - Guanine nucleotide effects on 8-cyclopentyl-1,3-[\(^3\)H]dipropylxanthine binding to membrane-bound and solubilized A\(_1\) adenosine receptors of rat brain
N2 - The effects of guanine nucleotides on binding of 8-cyclopentyl-1,3-[\(^3\)H]dipropylxanthine [\(^3\)H]DPCPX), a highly selective A\(_1\) adenosine receptor antagonist, have been investigated in rat brain membranes and solubilized A\(_1\) receptors. GTP, which induces uncoupling of receptors from guanine nucleotide binding proteins, increased binding of [\(^3\)H]DPCPX in a concentration-dependent manner. The rank order of potency for different guanine nucleotides for increasing [\(^3\)H]DPCPX bindingwas the same as for guanine nuc1eotide-induced inhibition of agonist binding. Therefore, a role for a guanine nucleotide binding protein, e.g., G\(_i\), in the regulation of antagonist binding is suggested. This was confirmed by inactivation ofGi by N-ethylmaleimide (NEM) treatment of membranes, which resulted in an increase in [\(^3\)H]DPCPX binding similar to that seen with addition of GTP. Kinetic and equilibrium binding studies showed that the GTP- or NEM-induced increase in antagonist binding was not caused by an affinity change of A\(-1\) receptors for [\(^3\)H]DPCPX but by an increased Bmu value. Guanine nucleotides had similar effects on membrane-bound and solubilized receptors, with the effects in the solubilized system being more pronounced. In the absence of GTP, when rnost receptors are in a high-affinity state for agonists, only a few receptors are labeled by [\(^3\)H]DPCPX. It is suggested that [\(^3\)H]DPCPX binding is inhibited when receptors are coupled to G\(_i\). Therefore, uncoupling of A\(_1\) receptors from G\(_i\) by guanine nucleotides or by inactivation of G\(_i\) with NEM results in an increased antagonist binding.
Key Words: Adenosine receptors-8 -Cyclopentyl-1,3-eH]dipropylxanthine-Antagenist binding-Guanine nucleotide effects. Klotz K.-N. et al. Guanine nucleotide etfects on 8-cyclopentyl-1 ,3-eH]dipropylxanthine binding to membrane-bound and solubilized A1 adenosine receptors of rat brain. J. Neurochem. 54, 1988-1994 (1990).
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60369
ER -
TY - JOUR
A1 - Gimpl, G.
A1 - Gerstberger, R.
A1 - Mauss, U.
A1 - Klotz, Karl-Norbert
A1 - Lang, R. E.
T1 - Solubilization and characterization of active neuropeptide-Y receptors from rabbit kidney
N2 - Active neuropeptide Y receptors were solubilized from rabbit kidney membranes using the zwitterionic detergent 3-[ (3-cholamidopropy l)dimethylammonio ]- 1-propanesulfonic acid (CHAPS). In membrane fragmentsandsoluble extracts neuropeptide Y bindingwas time dependent, saturable, reversible, and of high affinity. Scatchard analysis of equilibrium binding data indicated a single class of binding sites with respective Kn and Bmax values of 0.09 nM and 530 fmol/mg of protein for the membrane-bound receptors and 0.10 nM and 1585 fmol/mg of protein for the soluble receptors. Neuropeptide Y bindingwas specifically inhibited by the nonhydrolyzable GTP analog guanosine 5' -0- (3-thiotripbosphate) in a concentration-dependent manner, with IC\(_{50}\) values of 28 and 0.14 \(\mu\)M for membrane- bound and soluble receptors, respectively, suggesting that neuropeptide Y receptors are functionally coupled to GTP-binding regulatory proteins. CrossHoking studies were performed with the heterobifunctional N-hydroxysuccinimidyl-4-azidobenzoate and the monofunctional neuropeptide Y derivative, azidobenzoyl and led to the identification of a 100 kDa peptide that should represent the covalently labeled neuropeptide Y receptor.
KW - Toxikologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60375
ER -
TY - JOUR
A1 - Schmoll, T.
A1 - Ott, M.
A1 - Ougeda, B.
A1 - Hacker, Jörg
T1 - Use of a wild-type gene fusion to determine the influence of environmental conditions on expression of the S fimbrial adhesin in an Escherichia coli pathogen
N2 - S fimbrial adhesins (Sfa) enable pathogenic Escherichia coli strains to bind to sialic acid-containing eucaryotic receptor molecules. In order to determine the inftuence of culture conditions on the expression of the sfa determinant in a wild-type strain, we fused the gene lacZ, coding for the enzyme ß-galactosidase, to the sfaA gene, responsible for the major protein subunit of S fimbriae. By using a plasmid which carries an R6K origin, the sfaA-Iac hybrid construct was site-specifically integrated into the chromosome of the uropathogenic E. coli strain S36WT. The expression of lacZ, which was under the control of the sfa wild-type promoters, was now equivalent to the sfa expression of strain S36WT. With the help of this particular wild-type construct, it was demonstrated that the sfa determinant is better expressed on solid media than in liquid broth. The growth rate bad a strong inftuence on Sfa expression under aerobic but not under anaerobic conditions. Production of Sfa was further regulated by catabolite repression, osmolarity, and temperature.
KW - Infektionsbiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59625
ER -
TY - JOUR
A1 - Ventur, Y.
A1 - Scheffer, J.
A1 - Hacker, Jörg
A1 - König, W.
T1 - Effects of adhesins from mannose-resistant Escherichia coli on mediator release from human lymphocytes, monocytes and basophils and from polymorphonuclear granulo-cytes
N2 - We investigated the roJe of Escherichia coU expressing mannose-resistant hemagglutination and adhesins with regard to the induction of leukotrienes from a suspension of human lymphocytes, monocytes, and basophils (LMBs) compared with human polymorphonuclear granulocytes (PMNs). Genetically cloned E. coli strains expressing various types of mannose-resistant hemagglutination (MRH+) were phagocytosed to a higher degree by monocytes than the nonadherent E. coli strain. The various strains dUfered in their capacity to induce a chemiluminescence response, which showed the same pattern for LMBs and PMNs. Stimulation of LMBs with bacteria alone, unlike granulocytes, did not activate the cells for the release of leukotrienes. However, preincubation of LMBs with bacteria decreased subsequent leukotriene formation when the cells were stimulated with calcium ionophore. The inhibitory eft'ect was dependent on the concentration of bacteria used for preincubation as weil as on the preincubation temperature. The various bacterial strains dift'ered in inhibitory potency for mediator release. Preincubation of LMBs with zymosan, opsonized zymosan, the bacterfal peptide FMLP, and peptidoglycan bad no inhibitory eft'ect or even increased subsequent IeukotrieDe formation. Opsonized bacteria were far less inhibitory than nonopsonized bacteria. In contrast to human LMBs, preincubation of human PMNs with mannose-resistant bacteria led to increased leukotriene 84 generation and reduced w-oxidation of leukotriene 84 • Our data soggest that phagocytes (neutrophils, monocytes) respond in a different way for leukotriene formation after Interaction with mannose-resistant E. coli.
KW - Infektionsbiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59636
ER -
TY - JOUR
A1 - Marre, R.
A1 - Kreft, B.
A1 - Hacker, Jörg
T1 - Genetically engineered S and F1C fimbriae differ in their contribution to adherence of Escherichia coli to cultured renal tubular cells
N2 - Escherichia coU K-12 strains producing S-fimbrial adhesins, FlC fimbriae, and mutagenized fimbriae were tested in a binding assay with a renal tubular cell line. S-fimbrial adhesins and FlC fimbriae mediated bindlog to tubular cells. The SfaA, SfaG, and SfaS subunits of S fimbriae contributed to attachment. Site-specific mutations in the sfaS gene reduced binding. The Inhibitionprofile of FlC fimbriae resembled that of S fimbriae.
KW - Infektionsbiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59644
ER -
TY - JOUR
A1 - Bender, L.
A1 - Ott, M.
A1 - Marre, R.
A1 - Hacker, Jörg
T1 - Genome analysis of Legionella spp. by orthogonal field alternation gel electrophoresis (OFAGE)
N2 - Various Legionella isolates from different sources and origins were analysed by orthogonal field alternation gel electrophoresis of Not I cleaved genomic DNA. The genome of L pneumophila Philadelphia I, the original isolate of the epidemics in 1976, exhibits only five Not I fragments. Two virulent derivatives. derived from L pneumophila Philadelphia I. which were obtained by prolonged passage on artificial cuhure media, did not differ from their isogenic virulent strain according the Not I fragment pattern. By summing the lengths of the Notl fragments, the genome size of L. pneumophila Philadelphia I was calculated as approximately 3.9 Mb. Environmental L pneumophila strains exhibited different Not I pattems, as did Legionella strains not belongi'ng to the species pneumophila. The usefulness of DNA long range mapping of Legionella ssp. with Notl for epidemiology and evaluation of their evolutionary rela· tionships is discussed.
KW - Infektionsbiologie
KW - Legionella ssp.
KW - Genome analysis
KW - Orthogonal field attenuation gel electrophoresis
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59657
ER -
TY - JOUR
A1 - Schmoll, T.
A1 - Morschhäuser, J.
A1 - Ott, M.
A1 - Ludwig, B.
A1 - Van Die, I.
A1 - Hacker, Jörg
T1 - Complete genetic organization and functional aspects of the Escherichia coli S fimbrial adhesin determinant: nucleotide sequence of the genes sfaB, C, D, E, F.
N2 - The S fimbrial adhesin (sfa) determinant of E. co/i comprises nine genes situated on a stretch of 7.9 kilobases (kb) DNA. Here the nucleotide sequence of the genes sfa B and sfaC situated proximal to the main structural gene sfaA is described. Sfa-LacZ fusions show that the two genes are transcribed in opposite directions. The isolation of mutants in the proximal region of the sfa gene cluster, the construction of sfa-phoA gene fusions and subsequent transcomplementation sturlies indicated that the genes sfaB and sfaC play a role in regulation of the sfa determinant. ln addition the nucleotide sequence of the genes sfa D, sfa E and sfa F situated between the genes sfaA and sfaG responsible for S subunit proteins, were determined. lt is suggested that these genes are involved in transport and assembly of fimbrial subunits. Thus the entire genetic organization of the sfa determinant is presented and compared with the gene clusters coding for P fimbriae (pap), F1 C fimbriae (foc) and type I fimbriae ( fim). The evolutionary relationship of fimbrial adhesin determinants is discussed.
KW - Infektionsbiologie
KW - Escherichia coli
KW - S fimbrial adhesin (Sfa)
KW - genetic organization
KW - gene regulation
KW - nucleotide sequence
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59661
ER -
TY - JOUR
A1 - Riegmann, N.
A1 - Kusters, R.
A1 - Van Veggel, H.
A1 - Bergmans, H.
A1 - Van Bergen en Henegouwen, P.
A1 - Hacker, Jörg
A1 - Van Die, I.
T1 - F1C fimbriae of an uropathogenic Escherichia coli: Genetic and functional organization of the foc gene cluster and identification of minor subunits
N2 - Tbe genetic organization of tbe foc gene duster bas been studied; six genes involved in tbe biogenesis of Fl C fimbriae were identifi.ed.focA encodes tbe major fimbrial subunit, focC encodes a product tbat is indispensable for fimbria formation,focG andjocH encode minor ftmbrial subunits, andfocl encodes a protein wbicb sbows similarities to the subunit protein FocA. Apart from tbe FocA major subunits, purified FlC fimbriae contain at least two minor subunits, FocG and FocH. Minor proteins of similar size were observed in purified S fimbriae. Remarkably, some mutations in tbe foc gene duster result in an altered 6mbrial morpbology, i.e., rigid stubs or long, curly ftmbriae.
KW - Infektionsbiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59597
ER -
TY - JOUR
A1 - Hacker, Jörg
A1 - Bender, L.
A1 - Ott, M.
A1 - Wingeder, J.
A1 - Lund, B.
A1 - Marre, R.
A1 - Goebel, W.
T1 - Deletions of chromosomal regions coding for fimbriae and hemolysins occur in vivo and in vitro in various extraintestinal Escherichia coli isolates
N2 - No abstract available
KW - Infektionsbiologie
KW - P-fimbriae
KW - hemolysin
KW - genomic deletions
KW - extraintestinal E. coli
KW - virulence modulation
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59608
ER -
TY - JOUR
A1 - Morschhäuser, J.
A1 - Hoschützky, H.
A1 - Jann, K.
A1 - Hacker, Jörg
T1 - Functional analysis of the Sialic acid-binding adhesin SfaS of pathogenic Escherichia coli by site-specific mutagenesis
N2 - The gene coding for the sialic acid-specific adhesin SfaS produced by the S fimbrial adhesin (sfa) determinant of Escherichia coli has been modified by oligonucleotide-directed, site-specific mutagenesis. Lysine 116, arginine 118, and Iysine 122 were replaced by threonine, serine, and threonine, respectively. The mutagenized gene dusters were able to produce S fimbrial adhesin complexes consisting of the S-specific subunit proteins including the adhesin SfaS. The mutant clones were further characterized by hemagglutination and by enzyme-linked immunoassay tests with antifimbria- and anti-adhesin-specific monoclonal antibodies, one of which is able to block S-specific binding (Moch et al., Proc. Natl. Acad. Sei. USA 84:3462-3466, 1987). The lysine-122 mutantclone was indistinguishable from the wild-type clone in these assays. Replacement of Iysine 116 and ai'ginine 118, however, abolished hemagglutination and resulted in clones which showed a weak (Iysine 116) or a negative (arginine 118) reaction with the antiadhesin-specific antibody Al. We therefore suggest that Iysine 116 and arginine 118 have an inßuence on binding of SfaS to the sialic acid residue of the receptor molecule. Substitution of arginine 118 by serine also had a negative efl"ect on the amount of SfaS adhesin proteins isolated from the S fimbrial adhesin complex.
KW - Infektionsbiologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59613
ER -
TY - JOUR
A1 - Karna, S.P.
A1 - Grein, F.
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
T1 - Ab initio configuration-interaction studies of the ground state potential energy and hyperfine coupling constants of \(^{35}\)Cl\(_2^-\)
N2 - Potential energy and spectroscopic constants for the X\(^2 \sum^+ _\mu\) ground state of a;, were calculated by configuration-interaction (Cl) methods, using large basis sets with polarization and diffuse functions. From these CI wavefunctions, the isotropic (a\(_{iso}\)) and dipolar (A\(_{dip}\)) components of the hyperfine coupling constant were obtained. The effects of various s, p basis sets, polarization and diffuse functions, as well as the influence of reference configurations and configuration selection thresholds were investigated. The best values obtained are 35·31 G for a\(_{iso}\) and 29·440 for A\(_{dip}\)• tobe compared with experimental values of 37 ± 1 G and 32 ± 1 G, respectively. It is shown that the contributions to a1so of the K and L shells are opposite in sign, differing by about 4 G. Upon vibrational averaging, both a\(_{iso}\) and A\(_{dip}\) move towards smaller values as v increases. An adiabatic electron affinity of 2·46eV was obtained for CL\(_2\) , and a vertical electron detachment energy of 3·71 eV for Cl;.
KW - Organische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58869
ER -
TY - JOUR
A1 - Funken, K.
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
A1 - Grein, F.
T1 - Study of the hyperfine coupling constants of the moleculs NH2, NHD and ND2
N2 - In the present paper we c:alculate tbe magnetic hyperfine couplina constants (hfcc) ai.ID and A11 of the ground states of the isotopes NH2, NHD and ND2 using truncated MR..CI methods. Differences from other theoretical methocls and shortoominp of the truncated Cl approach in calculating tlj10 are studied. Polarization effects wbich detennirae ailo. as weU as a simple model to describe the dipolar hfcc's, are discussed. All results are in. excellent aareement with experimental data. lt is shown that ab initio methods are able to obtain reliable values for otf-diaaonal values of A41 which are difficult to measure experimentaDy.
KW - Organische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58875
ER -
TY - JOUR
A1 - Jocher, R.
A1 - Rethwilm, Axel
A1 - Kappos, L.
A1 - ter Meulen, Volker
T1 - Search for retroviral sequences in peripheral blood mononuclear cells and brain tissue of multiple sclerosis patients
N2 - DNAs from peripheral blood mononuclear cells (PBMCs) of 21 patients with multiple sclerosis (MS), 1 patient with tropical spastic paraparesis (TSP) as well as DNAs from brain and spinal cord of 5 MS cases and 3 controls were examined for human T-cell lymphotropic virus (HTLV)-related sequences by polymerase chain reaction. The primers used were derived from the HTLV-1 gag, env and tax genes. Amplified products were separated on agarase gels, blotted onto nylon membranes and hybridized to specific radiolabelled oligonucleotides. The sensitivity of amplification and hybridization was one copy of target DNA in 10\8^5\) cellular genomes. None of the specimens was positive for HTLV-1 sequences except the TSP probe. These negative data are all the more significant because brain -material from MS patients was used in these studies. Our studies thus fail to support speculations that HTLV-I is involved in the aetiology of multiple sclerosis.
KW - Virologie
KW - Multiple sclerosis
KW - HTLV-I
KW - Polymerase chain reaction
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61462
ER -
TY - JOUR
A1 - Netzer, Kai O.
A1 - Rethwilm, Axel
A1 - Maurer, Bernd
A1 - ter Meulen, Volker
T1 - Identification of the major immunogenic structural proteins of human foamy virus
N2 - We have identified the major immunogenic structural proteins of the human foamy virus (HFV), a distinct member of the foamy virus subfamily of Retroviridae. Radiolabelied viral proteins were immunoprecipitated from HFV -infected cells by foamy virus antisera of human and non-human primate origin. Precipitated viral proteins were in the range of 31 K to 170K. Labelling of proteins with [\(^{14}\)C]glucosamine or with [\(^{35}\)S]methionine in the presence oftunicamycin, as well as endo-ß-N-acetylglycosaminidase Hand F treatment of [\(^{35}\)S]methionine-labelled proteins, revealed three viral glycoproteins of approximately 170K, 130K and 47K, most likely representing the env gene-encoded precursor, the surface glycoprotein and the transmembrane protein of HFV, respectively.
KW - Virologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61477
ER -
TY - JOUR
A1 - Rethwilm, Axel
A1 - Mori, Kazuyasu
A1 - Maurer, Bernd
A1 - ter Meulen, Volker
T1 - Transacting transcriptional activation of human spumaretrovirus LTR in infected cells
N2 - The long terminal repeat (LTR) of the human spumaretrovirus (HSRV) was examined with respect to its ability to function as transcriptional promotor in virus-infected and uninfected cells. Transient transfections using a plasmid in which the 3' L TR of HSRV was coupled to the bacterial chloramphenicol cetyltransferase (cat) gene revealed that the Ievei of HSRV LTR-directed cat gene expression was markedly increased in HSRV-infected cells compared to uninfected cells. Northern blot analysis of cat mRNA from transfected cultures suggests that transactivation of HSRVdirected gene expression occurs at the transcriptionallevel.
KW - Virologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61488
ER -
TY - JOUR
A1 - Rethwilm, Axel
A1 - Baunach, Gerald
A1 - Netzer, Kai O.
A1 - Maurer, Bernd
A1 - Borisch, Bettina
A1 - ter Meulen, V.olker
T1 - Infectious DNA of the human spumaretrovirus
N2 - An infectious molecular clone (pHSRV) of the human Spumaretrovirus (HSRV) was constructed using viral DNA and cDNA clones. The infectivity of pHSRV was proven by transfection of cell cultures and subsequent infection of susceptible cultures with cell free transfection derlved virus. pHSRV derived virus produced foamy virus typical cytopathic effects in susceptible cultures. lnfected cells could be stained specifically with foamy virus antisera by means of indirect immunofluorescence. Radiolmmunoprecipltatlon revealed the presence of characteristic HSRV structural proteins in pHSRV infected cultures. By cotransfection of pHSRV and an indicator plasmid it was found that pHSRV is able to transactivate the viral L TR. Viral transcripts were found to be approximately 200 bases Ionger in pHSRV infected cultures compared to wildtype infected cultures. This difference is most likely due to an Insertion of DNA of non-viral origin ln the U3 region of the 3'L TR of the infectious clone.
KW - Virologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61495
ER -
TY - JOUR
A1 - Waelbroeck, M.
A1 - Camus, J.
A1 - Tastenoy, M.
A1 - Lambrecht, G.
A1 - Mutschler, E.
A1 - Tacke, Reinhold
A1 - Christophe, J.
T1 - Stereoselectivity of procyclidine binding to muscarinic receptor subtypes M\(_1\), M\(_2\) and M\(_4\)
N2 - The goals of the present study were: (1) to investigate thc binding properlies oi (R)- and (S)-procyclidine and two aehiral derivatives of muscarinic M\(_1\)• M\(_2\) and M\(_4\) receptor subtypes and (2) to identify the interaetions which allow these receptors to diseriminate between the two stereoisomers. (R)-Procyclidine showed a higher affinity for human neuroblastoma NB-OK 1 muscarinie M\(_1\) and rat striatum musearinie M\(_4\) receptors. a~ compared to rat cardiac M\(_2\) receptors. (S)-Procyclidine had a 130-iold lower affinity than (R)-procyclidine for M\(_1\) and M\(_4\) receptors. and a 40-fold lower affinity for M\(_2\) receptors. Pyrrinol. the aehiral diphenyl derivative with the eyclohexyl g.roup of (S}-procyclidine replaeed by a phenyl group, has an eight-fold lower affinity for M\(_1\) and M\(_4\) receptors. as eompared to (R)-procyclidine, and a three-fold lower affinity for M\(_2\) receptors. Hexahydro-procyclidine. the eorresponding achiral dicyclohexyl compound, had a 10- to 20-fold lower affinity than (R)-procyclidine for the three reeeptors. The inerease in binding free energy, which is observed when the phenyl and eyclohexyl groups of procyelidine are separately replaeed by cyclohexyJ and phenyl groups, respectively. was additive in the ease of M\(_1\)• M\(_2\) and M\(_4\) receptcrs. This indicates that the musearinic reeeptor s!ereoseleetivity was based on the eoexistence of two binding sites, one preferring a phenylrather than eyclohexyl group and the seeond preferring a cyclohexyl rather than a phenyl group. In addition. there were aiso binding sites for the hydroxy moiety and the protonated amino group of the ligands. The greater affinity and stereoselectivity of M\(_1\) and M\(_4\) muscarinic receptors for (R)-procyelidine reflected the better fit of the eyclohexyl group of (R)-procyclidine to the subsite of M\(_1\) and M\(_4\) as compared to M\(_2\) receptors.
KW - Anorganische Chemie
KW - Musearlnie M1
KW - receptors
KW - Muscarinie M2 receptors
KW - Musearinic M4 receptors
KW - Pyrrinol
KW - Hexahydro-procyclidine
KW - Muscarinic receptors
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64034
ER -
TY - JOUR
A1 - Polidori, C.
A1 - Massi, M.
A1 - Lambrecht, G.
A1 - Mutschler, E.
A1 - Tacke, Reinhold
A1 - Melchiorre, C.
T1 - Selective antagonists provide evidence that M\(_1\) muscarinic receptors may mediate carbachol-induced drinking in the rat
N2 - The present study served to investigate the ability of seven selective muscarinic antagonists to inhibit carbachol-induced drinking in the rat. The muscarinic antagonists were given by intracerebroventricular (i.c.v.) injection 1 min before the i.c.v. injection of carbachol (1 \(\mu\)g/rat). The M\(_2\) antagonist, methoctramine, was inactive up to 80.3 nmol/rat. The M\(_3\) antagonist, p-fluoro-hexahydro-sila-difenidol, elicited a modest (42%) but statistically significant inhibition of drinking only at 80 nmol/rat. On the other band, the selective M\(_1\) antagonists, (R)-trihexyphenidyl, o-methoxy-sila-hexocyclium and pirenzepine, produced a marked and dose-dependent inhibition of carbachol-induced drinking, their 1050 values being 0.51. 7.36 and 9.31 nmoljrat. Also the M\(_1\)/M\(_3\) antagonists, 4-diphenylacetoxy-Nmethylpiperidine methiodide and hexahydro-sila-difen.idol, were potent inhibitors of carbachol-induced drinking, their ID\(_50\) values (0.28 and 11.09 nmoljrat) being related to their pA\(_2\) values for M1 receptors in rabbi t vas deferens. These data suggest that carbachol-induced drinking may be mediated by activation of muscarinic M\(_1\) receptors.
KW - Anorganische Chemie
KW - Carbachol-induced drinking
KW - Muscarinic receptor antagonists
KW - Muscarinic receptor subtypes
KW - Muscarinic M1 receptors; Muscarinic M2 receptors
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64044
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Fritsche, K.
A1 - Tafel, A.
A1 - Wuttke, F.
T1 - Synthese von racemischem Acetyl(t-butyl)methylphenylsilan und Acetylmethylphenyl[(trimethylsilyl)methyl]silan: Substrate für stereoselektive mikrobielle Reduktionen
KW - Anorganische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64055
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Becker, B.
A1 - Lange, H.
T1 - (Thioacetoxy-S-methyl)diorganylsilane und (Mercaptomethyl)diorganylsilane: Synthese und Eigenschaften
N2 - Die erstmalige Synthese der (Thioacetoxy-S-methyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (9) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (10) und der (Mercaptomethyl) diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SH (11) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SH (12) wird beschrieben. Während sich die Silane 9 und 10 leicht handhaben lassen, neigen die strukturanalogen (Hydroxymethyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OH (2) zu einer basenkatalysierten Zersetzung (Bildung oligomerer (polymerer) Alkoxysilane und Wasserstoff). Im Gegensatz zu den thermisch labilen (Acetoxymethyl)diorganylsilanen (CH\(_3\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (3) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (4) (--+ Umlagerung zu den entsprechenden Acetoxy(methyl) diorganylsilanen (CH\(_3\)) \(_3\)SiOC(O)CH\(_3\) (5) und CH\(_3\)(C\(_6\)H\(_5\))\(_2\)SiOC(O)CH\(_3\) {6)) sind die Thio-Analoga 9 und 10 thermisch stabil (I-molare Lösungen in C\(_6\)D\(_6\), 30 h bei 180 o C).
N2 - The novel synthesis of the (thioacetoxy-S-methyl)diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (9) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (10) and the (mercaptomethyl) diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)SH (11) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SH (12) is described. The silanes 11 and 12 areeasy to handle, whereas the structurally analogous (hydroxymethyl)diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OH (2) tend to undergo a base-catalyzed decomposition (formation of oligomeric (polymeric) alkoxysilanes and hydrogen). In cantrast to the thermally unstable (acetoxymethyl)diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (3) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (4) (--+ rearrangement to the corresponding acetoxy(methyl)diorganylsilanes (CH\(_3\)) \(_3\)SiOC(O)CH\(_3\) (5) and CH\(_3\)(C\(_6\)H\(_5\))\(_2\)SiOC(O)CH\(_3\) (6)), the thio-analogues 9 and 10 are thermally stable (1 molar solutions in C\(_6\)D\(_6\) , 30 h at 180°C).
KW - Anorganische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64065
ER -
TY - JOUR
A1 - Dörje, F.
A1 - Friebe, T.
A1 - Tacke, Reinhold
A1 - Mutschler, E.
A1 - Lambrecht, G.
T1 - Novel pharmacological profile of muscarinic receptors mediating contraction of the guinea-pig uterus
N2 - The present study was designed to further characterize the muscarinic receptors mediating contraction of the guinea-pig uterus. The affinities of various selective muscarinic antagonists were determined and compared with those obtained at M\(_1\) (rabbit vas deferens), M\(_2\) (guinea-pig atria) and M\(_3\) receptors (guinea-pig ileum). The contractile responses of uterine smooth muscle from immature guinea-pigs to carbachol (pD\(_2\) = 5.73) were competitively antagonized by pirenzepine (pA\(_2\) = 7.04), AF-DX 116 (11-[[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]- 5,11-dihydro-6H -pyrido[2,3-b][1 ,4]benzo. diazepin-6-one) (pA\(_2\) = 6.96), himbacine (pA\(_2\) = 7.92), methoctramine (pA\(_2\) = 7.52), 4-DAMP (4-diphenylacetoxy- N-methylpiperidine methiodide) (pA\(_2\) = 8.87) and sila-hexocyclium (pA\(_2\) = 8.81). A comparison of affinity values indicates that the muscarinic receptors present in guinea-pig uterus display a novel pharmacological profile which is not consistent with the presence of either an M\(_1\), M\(_2\) or M\(_3\) receptor. The affinities determined for the different antagonists rather showed a close similarity to those obtained at muscarinic receptors present in rat striatum and NG108-15 cells which are considered pharmacological equivalents (M\(_4\) receptors) of the m4 gene product. We thus hypothesize that the guinea-pig isolated uterus preparation may serve as a simple functional assay system to study the pharmacology of M\(_4\) receptors.
KW - Anorganische Chemie
KW - Muscarinic receptors
KW - M4 receptors
KW - Guinea-pig uterus
KW - Pirenzepine
KW - Methoctramine
KW - Sila-hexocyclium
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64071
ER -
TY - JOUR
A1 - Verspohl, E. J.
A1 - Tacke, Reinhold
A1 - Mutschler, E.
A1 - Lambrecht, G.
T1 - Muscarinic receptor subtypes in rat pancreatic islets: binding and functional studies
N2 - Cholinergie agents arepotent modulators of insulin release that aet via musearinie reeeptors. We now investigated the muscarinic receptor subtype present in rat panereatic islets in binding and funetional studies. Binding of 5 nM [ \(^3\)H]N-methylscopolamine ([\(^3\)H]NMS) was half maximal at 30 min. At 60 min, the maximal total bindingwas 1.29% and the non-specifie binding (presence of 100 ,uM atropine) was 0.18% of the total radioaetivity per 10 f.'g islet protein. Unlabelled atropine inhibited [\(^3\)H]NMS binding with an IC50 of ca. 30 nM. The rank order of antagonist high-affinity binding was atropine > sila-hexocyelium methyl sulfate (SiHC; M\(_1\) > M\(_3\) > M\(_2\) ) > pirenzepine (M\(_1\)> M\(_2\) = M\(_3\) ) = methoctramine (M\(_2\) > M\(_1\) > M\(_3\) ). The high-affinity K\(_d\)s were 8.5, 56, 1300 and 1300 nM, respectively. The high affinity Kd of the muscarinie receptor agonist, arecaidine propargyl ester (APE), was 8.1 nM. The EC\(_{50}\) for the biologieal effects of APE on insulin and glucagon secretion was 3.2 and 2.3 nM. The rank order for the high-affinity biological effects of antagonists (inhibition of APE-mediated insulin/ glucagon release) was almost the same as for binding. The data indicate that rat pancreatie islets contain neither an M\(_1\) subtype (high-affinity for pirenzepine) nor an M\(_2\) subtype (high-affinity for methoctramine) receptor. However, the data evidence an M\(_3\) receptor subtype, since SiHC in the absence of the M\(_1\) receptor subtype shows a relatively high affinity to the receptors in rat panereatic islets.
KW - Anorganische Chemie
KW - Muscarinic receptor subtypes
KW - Islets of Langerhans (rat)
KW - Insulin
KW - Glucagon
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63993
ER -
TY - JOUR
A1 - Feifel, R.
A1 - Wagner-Röder, M.
A1 - Strohmann, C.
A1 - Tacke, Reinhold
A1 - Waelbroeck, M.
A1 - Christophe, J.
A1 - Mutschler, E.
A1 - Lambrecht, G.
T1 - Stereoselective inhibition of muscarinic receptor subtypes by the enantiomers of hexahydro-difenidol and acetylenic analogues
N2 - 1 Tbc affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenie analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemieal purity > 99.8%) for musearlnie receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2 The (R)-enantiomers consistently showed higher aßinities than the (S)-isomers. The stereosclectivity ratios [(R)/(S)] wcrc greatest with thc enantiomers of 1 (vas deferens: 550; ilcum: 191; atria: 17) and least with thosc ofthc p-Fluoro-analogue 4 (vas defercns: 34; ileum: 8.5; atria: 1.7). 3 The enantiomerie potency ratios for compounds 1-4 were highest in rabbit vas deferens, intermediate in guinea-pig ileum and much less in guinea-pig atria. Thus, these ratios may serve as a predietor of muscarinic receptor subtype identity. 4 (S)-p-Fluoro-hexbutinol [(S)-4] showed a novel receptor selectivity profile with preference for M\(_3\) receptors: M\(_3\) > M\(_2\) \(\geq\) M\(_1\)• 5 These results do not conform to Pfeiffer's rule that aetivity differences between enantiomers are greater with more potent compounds.
KW - Anorganische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64002
ER -
TY - JOUR
A1 - Rettenmayr, N. M.
A1 - Rodrigues de Miranda, J. F.
A1 - Rijntjes, N. V. M.
A1 - Russel, F. G. M.
A1 - van Ginneken, C. A. M.
A1 - Strohmann, C.
A1 - Tacke, Reinhold
A1 - Lambrecht, G.
A1 - Mutschler, E.
T1 - Pharmacokinetic properties of the antimuscarinic drug [\(^3\)H]-hexahydro-sila-difenidol in the rat
N2 - The pharmacokinetics of tritiated hexahydrosila- difenidol ([\(^3\)H]-HHSiD) were examined in rats. Furthermore, the distribution of radioactivity was studied by means of whole body autoradiography. After i. v. administration of 2.9 mg/kg HHSiD plus [\(^3\)H]-HHSiD to anaesthetized rats bearing a catheter implanted in the ductus choledochus and receiving a mannitol infusion, HHSiD was rapidly distributed and metabolized. Only 5% ofthe radioactivity was recovered in blood after 23 s and 0.4% after 2.5 h. 64% of the plasma radioactivity could be extracted with hexane from the samples taken 23 s after administration. 52% of the radioactivity was eliminated within 2.5 h, 13% by urinary and 39% by biliary excretion. Following oral administration of 8.6 mg/kg HHSiD plus [\(^3\)H]-HHSiD there was an absorption of approximately one fourth of the administered radioactivity within 4 h. By means of whole body autoradiography (i. v. injection) as well as by tissue distribution measurement the highest Ievels of radioactivity were found in bile, urine, lung, kidney, adrenals, liver and .pancreas. Thus, after i. v. administration to rats HHSiD is rather quickly distributed, metabolized and excreted. This explains its low antimuscarinic potency in vivo.
KW - Anorganische Chemie
KW - Pharmacokinetics
KW - [3H]-Hexahydro-siladifenidol
KW - Sila-drug
KW - Rat
KW - Autoradiography
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64022
ER -
TY - JOUR
A1 - Lang, R.
A1 - Herzog, C.
A1 - Stangl, R.
A1 - Brunn, E.
A1 - Braun, M.
A1 - Christl, Manfred
A1 - Peters, K.
A1 - Peters, E.-M.
A1 - Schnering, H. G. von
T1 - Reaktionen von Homobenzvalenen mit 4-Phenyl-3H-1,2,4-triazol-3,5(4H)-dion, Tetracyanethylen, Chlorsulfonylisocyanat und Schwefeldioxid. Einige konzertierte 1,4-Additionen an eine Vinylcyclopropan-Einheit
T1 - Reactions of Homobenzvalenes wlth 4-Phenyl-3H-1,2,4-trlazole-3,5(4H)-dione, Tetracyanoethylene, Chlorosulfonyl Isocyanate, and Sulfur Dioxide. Several Concerted 1,4-Additions to a Vinylcyclopropane Subunit
N2 - No abstract available
KW - Organische Chemie
KW - 6-Thiatricyclo[3.2.1.o 2.7 ]oct-3-ene 6
KW - 6-dioxide
KW - Homo Diels-Alder reactions
KW - Cyclopropanetetracarbonitrile derivatives
KW - Barbaralane derivatives
KW - Urazoles
KW - polycyclic
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58527
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Reuchlein, H.
T1 - Synthesis and NMR Spectra of 2,3-Dihydro-1,3-methanoindene Derivatives and 1,2,3,5-Tetrahydro-1,3-methanopentalene
N2 - No abstract available
KW - Organische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58557
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Lanzendörfer, U.
A1 - Grötsch, M. M.
A1 - Ditterich, E.
A1 - Hegmann, J.
T1 - Cycloadditionen von 1,3,4-0xadiazin-6-onen (4,5-Diaza-alpha-pyronen), 9 - 6-Oxo-5-phenyl-1,3,4-oxadiazin-2-carbonsäure-methylester - Synthese und Reaktionen mit Norbornen, Norbornadien, Cyclopropenen, Cyclobuten und Benzvalen
N2 - No abstract available
KW - Organische Chemie
KW - 1
KW - 3
KW - 4-0xadiazin-6-ones
KW - Diels-Alder reactions
KW - y-Oxoketenes
KW - ß-Lactones
KW - bicyclic
KW - Enol Iactones
KW - alpha
KW - ß-unsaturated
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58569
ER -
TY - JOUR
A1 - Gessler, Manfred
A1 - Hameister, H.
A1 - Henry, I.
A1 - Junien, C.
A1 - Braun, T.
A1 - Arnold, H. H.
T1 - The human MyoD1 (MYF3) gene maps on the short arm of chromosome 11 but is not associated with the WAGR locus or the region for the Beckwith-Wiedemann syndrome
N2 - The human gene encoding the myogenic determination factor myf3 (mouse MyoD1) has been mapped to the short arm of chromosome 11. Analysis of several somatic cell hybrids containing various derivatives with deletions or translocations revealed that the human MyoD (MYF3) gene is not associated with the WAGR locus at chromosomal band 11pl3 nor with the loss of the heterozygosity region at 11p15.5 related to the Beckwith-Wiedemann syndrome. Subregional mapping by in situ hybridization with an myf3 specific probe shows that the gene resides at the chromosomal band llp14, possibly at llp14.3.
KW - Biochemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59221
ER -
TY - JOUR
A1 - van Heyningen, V.
A1 - Bickmore, W. A.
A1 - Seawright, A.
A1 - Fletcher, J. M.
A1 - Maule, J.
A1 - Fekete, G.
A1 - Gessler, Manfred
A1 - Bruns, G. A.
A1 - Huerre-Jeanpierre, C.
A1 - Junien, C.
T1 - Role for the Wilms tumor gene in genital development?
N2 - No abstract available
KW - Biochemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59238
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Reuchlein, H.
T1 - Synthesen und NMR-Spektren von 2,3-Dihydro-1,3-methanoindenderivaten und 1,2,3,5-Tetrahydro-1,3-methanopentalen
N2 - No abstract available
KW - Organische Chemie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58549
ER -
TY - JOUR
A1 - Pfeiffer, A.
A1 - Hanack, C.
A1 - Kopp, R.
A1 - Tacke, R.
A1 - Moser, U.
A1 - Mutschler, E.
A1 - Lambrecht, G.
A1 - Herawi, M.
T1 - Human Gastric Mucosa Expresses Glandular M3 Subtype of Muscarinic Receptors
JF - Digestive Diseases and Sciences
N2 - Five subtypes of muscarinic receptors have been distinguished by pharmacological and molecular biological methods. This report characterizes the muscarinic subtype present in human gastric mucosa by radioligand binding studies. The receptor density was 27 ± 6 fmol/mg protein and the tritiated ligand N-methylscopolamine had an affinity of (Kn) 0.39 ± 0.08 nM (n = 11). The M1 receptor selective antagonist pirenzepine and the M2 receptor selective ligand AF-DX 116 had low affinities of 148 ± 32 nM (n = 13) and 4043 ± 1011 nM (n = 3) K n , respectively. The glandular M3 antagonists hexahydrosiladifenidol and silahexocyclium had high affinities ofKn 78 ± 23 nM (n = 5) and 5.6 ± 1.8 nM (n = 3). The agonist carbachol interacted with a single low-affinity site and binding was insensitive to modulation by guanine nucleotides. Antagonist and agonist binding studies thus showed an affinity profile typical of M3 receptors of the glandular type.
KW - glandular M3 receptor
KW - acid secretion
KW - muscarinic receptor subtype
KW - human gastric mucosa
KW - stomach
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128286
VL - 35
IS - 12
ER -
TY - JOUR
A1 - Pfeiffer, A.
A1 - Rochlitz, H.
A1 - Noelke, B.
A1 - Tacke, R.
A1 - Moser, U.
A1 - Mutschler, E.
A1 - Lambrecht, G.
T1 - Muscarinic receptors mediating acid secretion in isolated rat gastric parietal cells are of M3 type
JF - Gastroenterology
N2 - Five subtypes of muscarinic receptors have been identified by pharmacological and molecular biological methods. The muscarinic receptor subtype mediating acid secretion at the level of the parietal cell was unknown. Therefore, this study was performed to characterize muscarinic receptors on rat gastric parietal cells using the 3 subtype-selective antagonists hexahydrosiladifenidol and silahexocyclium, which have high affinity for glandular M3 subtypes, and AF-DX 116, which has high affinity to cardiac M2 receptors. The affinity of these antagonists was determined by radioligand binding experiments. In addition, their inhibitory potency on carbachol-stimulated inositol phosphate production was investigated. Inhibition of carbachol-stimulated aminopyrine uptake was used as an indirect measure of proton production. Both M3 antagonists, hexahydrosiladifenidol and silahexocyclium, had nanomolar affinities for parietal cell muscarinic receptors and potently antagonized inositol phosphate production with nanomolar Ki values. Silahexocyclium similarly antagonized aminopyrine accumulation while hexahydrosiladifenidol behaved as a noncompetitive antagonist. AF-DX 116 was a low-affinity ligand and a weak competitive antagonist at parietal-cell muscarinic receptors. It was concluded that muscarinic M3 receptors mediate acid secretion probably by activation of the phosphoinositide second messenger system in rat gastric parietal cells.
KW - hexahydrosiladifenidol
KW - muscarinic receptors
KW - parasympatholytics
KW - radioligand assay
KW - parasympatholytics/pharmacology
KW - gastric acid/secretion
KW - animals
KW - piperidines/pharmacology
KW - piperazines/pharmacology
KW - gastric/secretion parietal cells
KW - muscarinic/physiology receptors
KW - muscarinic/drug effects receptors
KW - rats
KW - piperidines
KW - piperazines
KW - silahexocyclium
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128337
VL - 98
IS - 1
ER -
TY - JOUR
A1 - Fiala, Brigitte
A1 - Maschwitz, Ulrich
T1 - Studies on the south east asian ant-plant association Crematogaster borneensis / Macaranga: adaptations of the ant partner.
N2 - C. borneensis (Myrmicinae) lives in dose association with several myrmecophytic species of the South East Asian pioneer tree genus Macaranga (Euphorbiaceae). The ants are adapted to the plants so dosely that they do not survive away from it. The only food they utilize is provided as food bodies by the plant and honeydew from specific scale insects kept inside the hollow internodes. The anatomy of the digestive tract is also adapted to life on the host plant: the crop is very sm all and can store only minute food quantities. C. borneensis exdusively colonizes certain Macaranga species. Queens as weIl as workers are able to recognize their host plant species, probably by chemical cues. Colony founding queens swarm throughout the year, mostly during darkness. There is strong competition among queens for host plants. Queens do not carry scale insects on their nuptial flight. Worker ants are active day and night. Most of them patrol and collect food bodies on the younger parts of the host plant. An important characteristic is their deaning behaviour, which results in removal of aIl foreign objects. Even though they are rather smalI, workers respond very aggressively to certain kinds of disturbance of the host plant. The ants attack most phytophagous insects and are especially effective in killing and removing smalI, softbodied herbivores (e.g. caterpillars). They do not possess a functional sting, but apply defensive secretion and-once biting an intruder-will not let go. Their effective alarm system results in a mass attack, which provides adequate defence for the colony and the host plant. A comparison with another Crematogaster species further illustrated the special adaptations of C. borneensis to its host plant.
N2 - Untersuchungen über die südostasiatische Ameisen·Pflanzen-Vergesellschaftung Cremattogaster borneensis Maoaranga : Anpassungen des Ameisenpartners 213 C. borneensis (Myrmicinae) lebt in enger Gemeinschaft mit myrmekophytischen Arten der südostasiatischen Pionierbaumgattung Macaranga (Euphorbiaceae) . Die Ameise ist so eng an die Pflanze adaptiert, daß sie getrennt von ihr nicht lebensfähig ist. Die Nahrung bezieht C. borneensis in Form von Nährkörperchen ausschließlich von der Pflanze. Im Sproßachseninnern gehaltene spezifische Schildläuse bieten eine weitere Nahrungsquelle. Die Adaptationen erstrecken sich bis auf die Anatomie des Verdauungstraktes : Der Kropf ist sehr klein und kann nur geringe Nahrungsmengen speichern. C. borneensis besiedelt spezifisch nur Macaranga-Pflanzen. Sowohl Königinnen als auch Arbeiterinnen sind in der Lage, die Wirtspflanze zu erkennen, wobei offenbar chemische Reize eine Rolle spielen. Die koloniegründenden Königinnen schwärmen das gesamte Jahr über, das Schwärmen erfolgt überwiegend während der Dunkelheit. Um die besiedlungsfähigen Macaranga-Pflanzen herrscht ein starker Konkurrenzdruck. Die beteiligten Schildlausarten sind spezifisch für die Assoziation. Sie werden nicht von der Königin beim Hochzeitsflug mitgenommen. Die Arbeiterinnen sind tag- und nachtaktiv. Die meisten Tiere halten sich im jüngsten Drittel der Pflanze auf, wo sie patrouillieren und Nährkörperchen sammeln. Mittels eines spezifischen Säuberungsverhaltens entfernen die Arbeiterinnen alle Fremdobjekte von der Pflanze. Trotz ihrer geringen Größe attackieren die Ameisen eine Vielzahl phytophager Insekten und sind dabei besonders effektiv in der Abwehr kleiner, wenig sklerotisierter Tiere wie z.B. Raupen. Sie verfügen zwar nicht ' über einen funktionsfähigen Stachel, setzen aber Wehrsekrete ein und beißen sich hartnäckig fest . Mit Hilfe eines effektiven Alarmierungssystems, das einen Massenangriff ermöglicht, gewährleisten sie eine Verteidigung ihrer Kolonien und damit gleichzeitig ihrer Wirtspflanze. Eine Vergleich mit einer anderen Crematogaster-Art demonstriert die besonderen Adaptationen von C. borneensis an ihre Wirtspflanze.
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32689
ER -
TY - JOUR
A1 - Schüssler, Ulrich
T1 - Petrographie, Geochemie und Metamorphosealter von Metabasiten im KTB-Zielgebiet Oberpfalz
N2 - An Metabasiten der Zone Erbendorf-Vohenstrauß, der Erbendorfer Grünschieferzone und der Zone Tirschenreuth-Mähring wurden petrographische, geochemische und phasenpetrologische Untersuchungen sowie K-Ar-Mineraldatierungen durchgeführt. In der Zone Erbendorf-Vohenstrauß treten in regionaler Abhängigkeit drei Haupttypen von Metabasiten auf: 1. Flaseramphibolite mit der Paragenese Hornblende + Oligoklas/ Andesin + Granat ± Salit und mit Plagioklas- und / oder Kalksilikat-reichen Flasern findet man hauptsächlich im nördlichen und zentralen Teil der Zone Erbendorf-Vohenstrauß. Geochemisch zeigen sie eine deutliche Anreicherung der inkompatiblen Elemente und der leichten Seltenerdelemente und sind vergleichbar mit modernen Tholeiiten von ozeanischen Inseln oder anomalen Abschnitten mittelozeanischer Rükken. Ein kontinentaler Intraplatten-Charakter scheint nicht gegeben. In der Kontaktaureole von Windisch-Eschenbach wurde ein Teil der Flaseramphibolite kontaktmetamorph überprägt. 2. Schiefrige, teils streifige Amphibolite mit der Paragenese Hornblende + Andesin / Labrador ± Salit dominieren im Süd teil der Zone Erbendorf-Vohenstrauß, erscheinen aber in einzelnen Ausstrichen auch im Norden. Die Streifung entsteht durch Plagioklas- und / oder Kalksilikat-reiche Zwischenlagen. Geochemisch sind diese Amphibolite bei flachen Spurenelement- und Seltenerdelement- Mustern vergleichbar mit modernen Tholeiiten von normalen Abschnitten mittelozeanischer Rücken. Sowohl Flaseramphibolite als auch schiefrige, teils streifige Amphibolite zeigen Übergänge zu massigen, homogenen Amphiboliten. 3. Metagabbros mit der Paragenese Hornblende + Plagioklas ± Biotit und einer grobkörnigen, gabbro iden Textur treten hauptsächlich im Bereich der Schuppenzone Michldorf-Kaimling (VOLL 1960) auf. Geochemisch nehmen sie bei einer schwachen Anreicherung der inkompatiblen Elemente eine Zwischenstellung zwischen Flaseramphiboliten und schiefrigen, teils streifigen Amphiboliten ein. In der Erbendorfer Grünschieferzone treten Metagabbros und schiefrige, teils gestreifte Amphibolite mit der Paragenese Hornblende + Oligoklas ± Epidot ± Chlorit auf. Die Amphibolite wurden z. T. stark retrograd überprägt und dabei auch deformiert. Dies wird auf größere, post-regionalmetamorphe, tektonische Bewegungen, möglicherweise Deckenüberschiebungen zurückgeführt. Geochemisch sind die Metabasite der Erbendorfer Grünschieferzone mit modernen tholeiitischen bis kalkalkalischen, subduktionsgebundenen Basalten vergleichbar. Sie unterscheiden sich damit völlig von den südlich angrenzenden Flaseramphiboliten der Zone Erbendorf-Vohenstrauß und den nördlich benachbarten Amphiboliten des Fichtelgebirges. Dies unterstreicht die Stellung der Erbendorfer Grünschieferzone als eigenständige tektonische Einheit. Im Vergleich mit dem Münchberger Komplex zeigt die Erbendorfer Grünschieferzone große Ähnlichkeit mit der Prasinit-Phyllit-Serie hinsichtlich der tektonischen Stellung, der Lithologie und insbesondere des geochemischen Charakters der Metabasite. Zwischen der Zone Erbendorf-Vohen-strauß und den Münchberger Serien konnten bezüglich der Metabasite dagegen keine Parallelen festgestellt werden. Schiefrige, teils streifige Amphibolite der Zone Tirschenreuth-Mähring mit der Paragenese Hornblende + Andesin ± Salit (± Granat) und hellen Plagioklas- oder Kalksilikat-reichen Lagen sind geochemisch mit modernen Basalten normaler mittel ozeanischer Rücken vergleichbar. Die untersuchten Metabasite dürften die Zusammensetzung des basaltischen Ausgangsmaterials zumindest annähernd wiedergeben. In einigen Fällen wurde jedoch eine sekundäre Mobilisation von Elementen festgestellt: Die kontaktmetamorphe Überprägung eines Teils der Flaseramphibolite in der Kontaktaureole von Windisch-Eschenbach führte zu einer deutlichen Anreicherung von Rb, Li und K und zu einer Abreicherung von Ca, Sr und V, insbesondere aber von Cr und Ni. Die sog. immobilen Elemente Nb, Ce, (P), Zr, Ti, Y, Sc streuen in einem deutlich breiteren Bereich als bei den nicht kontaktmetamorphen Flaseramphiboliten. In einer Probe sind die Seltenerdelemente insgesamt angereichert. Eine Mobilisation von P20 S und den leichten Seltenerdelementen in einigen schiefrigen, teils streifigen Amphiboliten der Zone Erbendorf-Vohenstrauß und in einigen kontaktmetamorphen Flaseramphiboliten wird auf einen Abbau von Apatit im Zuge einer post-regionalmetamorphen, möglicherweise postgranitischen, hydrothermalen Überprägung zurückgeführt. Mineralchemische Untersuchungen ergaben für die Zusammensetzung der Hornblenden aus Amphiboliten der Zone Erbendorf-Vohenstrauß deutliche regionale Unterschiede, die weitgehend unabhängig von der regionalen Verteilung der einzelnen Metabasit-Haupttypen sind. Vergleichende Untersuchungen an Granat untermauern eine vermutete, frühere, eklogitfazielle Überprägung eines Granatamphibolits vom Nordrand der Zone Erbendorf-Vohenstrauß bei Hauxdorf. K-Ar-Altersdatierungen an Hornblende- und Glimmerkonzentraten belegen, daß das letzte, (Mitteldruck-) metamorphe Ereignis im Westteil der Zone Erbendorf-Vohenstrauß vor etwa 380 Ma beendet war. Dieses Alter wird korreliert mit einer letzten Metamorphose der höhermetamorphen Serien des Münchberger Komplexes zur gleichen Zeit. Im Ostteil der Zone Erbendorf-Vohenstrauß treten jüngere Altersdaten mit einem Schwerpunkt bei 324 Ma auf, die entweder auf einen Einfluß der etwa gleichalten Niederdruck-Metamorphose im unmittelbar benachbarten Moldanubikum i. e. S. oder auf die Intrusion des 324 Ma alten (KÖHLER et al. 1974) Leuchtenberger Granits zurückzuführen sind. Im Übergangsbereich vom Saxothuringikum zum Moldanubikum bei Mähring zeigen Altersdaten um 320Ma das Ende der letzten (Niederdruck-)Metamorphose an.
N2 - Petrographical, petrological and geochemical investigations as well as K-Ar mineral-dating were carried out on metabasites of the Zone Erbendorf-Vohenstrauß, the Erbendorf Greenschist Zone and the Zone Tirschenreuth-Mähring. Within the Zone Erbendorf-Vohenstrauß, three main types ofmetabasites occur in a clear regional distribution: 1. Flaseramphibolites with hornblende + oligoclase I andesine + gamet ± salite and with ill-defined plagioclase- and I or calc-silicate-rich flaser texture are dominating in the northern and central part ofthe Zone Erbendorf-Vohenstrauß. Geochemically, they are clearly enriched in incompatible elements and light rare earth elements and compare well with modern tholeiites of ocean islands or anomalous mid-ocean ridge segments. There are no indications for a continental within-plate character. 2. Schistose, partly striped amphibolites with hornblende + andesine I labradore ± salite prevail in the southern part of the Zone Erbendorf-Vohenstrauß, but also occur in some outcrops of the northern part. Stripes are formed by plagioclase- and I or calc-silicat-rich intercalations. Geochemically, these amphibolites with flat trace element- and rare earth element patterns are similar to modern tholeiites from normal mid-ocean ridges. Flaseramphibolites as well as schistose, partly striped amphibolites sometimes form transitions to massive, homogeneous amphibolites. 3. Metagabbros with hornblende + plagioclase ± biotite in a coarse, gabbroic structure mainly occur within the "Schuppenzone Michldorf-Kaimling" (VOLL 1960). Geochemically, they are transitional between flaseramphibolites and schistose, partly striped amphibolites. Within the Erbendorf Greenschist Zone, metagabbros and schistose, sometimes striped amphibolites with hornblende + oligocJase ± epidote ± chlorite occur. Part of them underwent astrang retrograde overprint, accompanied by deformation. This may be a consequence oflarge, post-regionalmetamorphic tectonic movements, possibly nappe-thrusting. Geochemically, the metabasites of the Erbendorf Greenschist Zone can be compared with modem tholeiitic to calc-alkaline, subduction-bound basalts. Thus, they differ c1early from flaseramphibolites ofthe Zone Erbendorf-Vohenstrauß in the south and amphibolites ofthe Fichtelgebirge in the north. This underscores the position of the Erbendorf Greenschist Zone as aseparate tectonic unit. Compared with units ofthe Münchberg complex, a elose correlation exists between the Erbendorf Greenschist Zone and the Prasinit-Phyllit-Serie relative to the tectonic position, the lithology and especially the geochemistry of metabasites. In contrast, a correlation between the Zone Erbendorf-Vohenstrauß and the crystalline units ofthe Münchberg complex is not encouraged by the composition of the metabasites. Schistose, partly striped amphibolites ofthe Zone Tirschenreuth-Mähring with hornblende + andesine ± salite (± gamet) and sometimes plagioelase- or ca1c-silicate-rich intercalations are geochemically similar to modem basalts of normal mid-ocean ridges. In most ofthe investigated metabasites the geochemical composition ofthe basaltic protoliths may be approximately conserved. In some cases, however, secondary element mobilization was recognized: The contact-metamorphic overprint of some flaseramphibolites led to an enrichment of Rb, Li and K and a simultaneous dep1etion ofCa, Sr and V, especially ofCr and Ni. The elements Nb, Ce, (P), Zr, Ti, Y, Sc, commonly regarded as immobile, scatter in a much wider range than in the unaffected flaseramphibolites. In one sampIe the rare earth elements are enriched. A mobilization of P2Üs and the light rare earth elements in some schistose, partly striped amphibolites ofthe Zone Erbendorf-Vohenstrauß as weil as some contact-metamorphosed flaseramphibolites is presumably a result of apatite decomposition during a post-regionalmetamorphic, possibly postgranitic hydrothermal overprint. Homblendes with different chemical compositions from amphibolites ofthe Zone ErbendorfVohenstrauß show a elear regional distribution which is almost entirely independent from the distribution of the main metabasite types. A comparison of gamet compositions underscores the eelogitic precursor rock of the gamet-amphibolite from Hauxdorf near Erbendorf. K-Ar dating on homblendes and micas verify that the last (medium-pressure) metamorphic event in the western part ofthe Zone Erbendorf-Vohenstrauß ended 380 Ma ago. This correlates with the last metamorphic overprint of the Münchberg crystalline units at the same time. In the eastern part of the Zone Erbendorf-Vohenstrauß younger ages around 324 Ma occur. This either refers to an influence from the last (low-pressure) metamorphism ofthe neighbouring Moldanubian s.str. with nearly the same age, or to an influence by the intrusion ofthe 324 Ma old (KÖHLER et al. 1974) Leuchtenberg granite. K-Ar ages of about 320 Ma from the transition between the Saxothuringian and the Moldanubian near Mähring testjfy to the end of the last (low-pressure) metamorphic overprint in this area.
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31694
N1 - Zugl. Diss. Univ. Würzburg, 1990
ER -
TY - GEN
T1 - Jahresbericht 1989
T1 - Annual Report 1989
N2 - Die Entwicklung der Universitätsbibliothek Würzburg im Jahr 1989.
N2 - Annual Report of the University Library of Würzburg, 1989.
T3 - Jahresbericht der Universitätsbibliothek Würzburg - 1989
KW - Würzburg
KW - Universitätsbibliothek
KW - Bericht
KW - Jahresbericht
KW - Würzburg
KW - University Library
KW - Report
KW - Annual Report
KW - Wuerzburg
KW - Wurzburg
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42333
ER -
TY - CHAP
A1 - Ellgring, Johann Heinrich
T1 - Sozialpsychologie: Ätiologie/Bedingungsanalyse
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41991
ER -
TY - CHAP
A1 - Klawitter, Jörg
A1 - Kümmel, Reiner
A1 - Maier-Rigaud, Gerhard
T1 - Verantworteter Umgang mit der Natur? - Philosophische Hintergründe und gesellschaftliche Komplexität -
N2 - No abstract available
KW - Natur
KW - Industriegesellschaft
KW - Aufsatzsammlung
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44400
ER -
TY - CHAP
A1 - Irrgang, Bernhard
A1 - Klawitter, Jörg
T1 - Künstliche Intelligenz: technologischer Traum oder gesellschaftliches Trauma?
N2 - No abstract available
KW - Künstliche Intelligenz
KW - Aufsatzsammlung
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44419
ER -
TY - CHAP
A1 - Klawitter, Jörg
T1 - Umwelt, Umweltschutz, Umweltpolitik
N2 - No abstract available
KW - Umwelterziehung
KW - Sozialkundeunterricht
KW - Aufsatzsammlung
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44329
ER -
TY - JOUR
A1 - Irngartinger, H.
A1 - Reimann, W.
A1 - Lang, R.
A1 - Christl, Manfred
T1 - Electron Density Distribution in a Bicyclo[l.l.0]butane
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31576
ER -
TY - BOOK
A1 - Marohn, Frank
T1 - On statistical information of extreme order statistics
N2 - No abstract available
KW - Rangstatistik
KW - Extremwert
KW - Statistik
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47866
N1 - Zugl.: Siegen, Univ.-Gesamthochschule, Diss., 1990
ER -
TY - JOUR
A1 - Weising, K.
A1 - Fiala, Brigitte
A1 - Ramloch, K.
A1 - Kahl, K.
A1 - Epplen, J. T.
T1 - Olingonucleotide fingerprinting in angiosperms
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42884
ER -
TY - JOUR
A1 - Hommers, Wilfried
T1 - Entschuldigung, Drittentschädigung und Schadenshöhe als Einflußgrößen des Urteils von Kindern und Erwachsenen
N2 - Kinder aus 3 Altersgruppen und Erwachsene beurteilten die verdiente Strafe für in Geschichten dargestellte Sachschäden, die aus Versehen oder aus Wut erfolgten. In den Geschichten wurde die Schadenshöhe variiert und außerdem, ob sich der Täter entschuldigte oder nicht bzw. ob der Geschädigte von einem Dritten eine Entschädigung erhielt oder nicht. Entschuldigung und Schadenshöhe hatten altersstabile Wirkungen, Entschuldigung etwa zweimal so stark wie die Schadenshöhe. Entschuldigung und Drittentschädigung hatten etwa gleichgroße Wirkungen, außer bei den Erwachsenen, bei denen die Wirkung der Drittentschädigung etwa auf die Stärke der Schadenswirkung abnahm. Der ursprüngliche Schaden war auch bei erfolgter Entschädigung, wenngleich schwächer, wirksam. Die Wirkungen der Ersatzleistung durch den Täter auf Strafurteile waren jedoch nicht völlig durch die Wirkungen von Entschuldigung und Entschädigung, erklärbar.
N2 - Children of three age groups and adults rated the deserved punishment for vignettes describing property damages done inadvertantly or in anger. The amount of damage varied in the stories as weIl as whether the harmdoer apologized or whether someone else compensated the harm. The effect of apology and amount of damage were unrelated to age. Apology reduced the punishment twice as much as amount of damage. The effect of third-party compensation was the same as that of apology, but was reduced in adults to around the amount of damage. Even after compensation of the damage, the prior amount of damage was still - though to a lesser degree - relevant for the punishment judgments. However, the total explanation of the effects of the harmdoer's restitution by apology and third-party compensation was not possible.
KW - Angewandte Psychologie / Zeitschrift / Experimentelle Psychologie
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44095
ER -
TY - JOUR
A1 - Sendtner, Michael
A1 - Kreutzberg, Georg W.
A1 - Thoenen, Hans
T1 - Ciliary neurotrophic factor (CNTF) prevents the degeneration of motor neurons after axotomy
N2 - The period of natural cell death in the development of rodent motor neurons is followed by a period of sensitivity to axonal injury1-3. In the rat this early postnatal period of vulnerability coincides with that of very low ciliary neurotrophic factor (CNTF) levels in the sciatic nerve before CNTF increases to the high, adult levels4. The developmental time course of CNTF expression, its regional tissue distribution and its cytosolic localization (as suggested by its primary structure)4*5 favour a role for CNTF as a lesion factor rather than a target-derived neurotrophic molecule like nerve growth factor. Nevertheless CNTF exhibits neurotrophic activity in vitro on different populations of embryonic neurons6. To determine whether the vulnerability of motor neurons to axotomy in the early postnatal phase is due to insufficient availability of CNTF, we transected the axons of newborn rat motor neurons and demonstrated that iocal application of CNTF prevents the degeneration of the corresponding cell bodies.
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32637
ER -
TY - JOUR
A1 - Dabauvalle, Marie-Christine
A1 - Loos, Karin
A1 - Scheer, Ulrich
T1 - Identification of a soluble precursor complex essential for nuclear pore assembly in vitro
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32801
ER -
TY - CHAP
A1 - Held, Winfried
T1 - Künstliche Beleuchtung und Architektur
N2 - No abstract available
KW - Griechenland / Beleuchtung / Architektur
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39125
ER -
TY - CHAP
A1 - Schüssler, Ulrich
A1 - Okrusch, Martin
A1 - Seidel, Eberhard
A1 - Kreuzer, Hans
A1 - Raschka, Helmut
T1 - Pre- to early Variscan magmatism in the Bohemian Massif
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39171
ER -
TY - JOUR
A1 - Scheer, Ulrich
A1 - Benavente, Ricardo
T1 - Functional and dynamic aspects of the mammalian nucleolus
N2 - Nucleoli are the sites of ribosome biogenesis. Transcription of the ribosomal RNA genes as well as processing and initial packaging of their transcripts with ribosomal and non-ribosomal proteins all occur within the nucleolus in an ordered manner and under defined topological conditions. Components of the nucleolus have been localized by immunocytochemistry and their functional aspects investigated by microinjection of antibodies directed against the enzyme responsible for rDNA transcription, RNA polymerase I. The role of nascent transcripts in postmitotic formation of nucleoli will be discussed.
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34269
ER -
TY - JOUR
A1 - Dandekar, Thomas
T1 - Hefezellen - ein gutes Modell für höhere Zellen
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29726
ER -
TY - JOUR
A1 - Dandekar, Thomas
A1 - Sibbald, Peter R.
T1 - Trans-splicing of pre-mRNA is predicted to occur in a wide range of organisms including vertebrates
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29798
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Krimm, Stefan
A1 - Kraft, Arno
T1 - Some Valenes of Benzannelated Five-Membered Heteroarenes - Synthesis and NMR Spectra
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30026
ER -
TY - JOUR
A1 - Hovestadt, Thomas
T1 - Möglichkeiten und Kriterien für die Bestimmung von Minimalarealen von Tierpopulationen und Ökosystembeständen
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30150
ER -
TY - JOUR
A1 - Gessler, Manfred
A1 - Poustka, Annemarie
A1 - Cavenee, Webster
A1 - Neve, Rachael L.
A1 - Orkin, Stuart H.
A1 - Bruns, Gail A.
T1 - Homozygous deletion in Wilms tumours of a zinc-finger gene identified by chromosome jumping
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30122
ER -
TY - JOUR
A1 - Hovestadt, Thomas
T1 - Die Bedeutung zufälligen Aussterbens für die Naturschutzplanung
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30136
ER -
TY - JOUR
A1 - Arakawa, Yoshihiro
A1 - Sendtner, Michael
A1 - Thoenen, Hans
T1 - Survival effect of ciliary neurotrophic factor (CNTF) on chick embryonic motoneurons in culture: comparison with other neurotrophic factors and cytokines
N2 - No abstract available
Y1 - 1990
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31718
ER -