TY - CHAP
A1 - Ulrichs, Karin
A1 - Euler, HH
A1 - Müller-Ruchholtz, W.
T1 - A Clinically Successful Protocol to Suppress Autoantibody Production in SLE Patients Is Analyzed For Its Efficacy To Inhibit Natural Xenophile Antibodies (NXA)
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45693
ER -
TY - JOUR
A1 - Adeyemo, O. M.
A1 - Shapira, S.
A1 - Tombaccini, D.
A1 - Pollard, H.
A1 - Feuerstein, G.
A1 - Sirén, Anna-Leena
T1 - A goldfish model for evaluation of the neurotoxicit of \(\omega\)-conotoxin GVIA and screening of monoclonal antibodies
N2 - A Goldfish Model for Evaluation of the Neurotaxicity of \(\omega\)-Conotoxin GVI A and Screening of Monoclonal Antibodies. ADEYEMO, 0. M .. SHAPIRA, S., TOMBACCINI, D., POLLARD, H. 8 .• FEUERSTEIN, G .. AND SIREN, A-L. ( 1991 ). Toxicol. App/. Pharmaco/. 108, 489-496. The neurotoxicity of \(\omega\)-conotoxin (\(\omega\)-CgTx), a potent neuronal voltage-sensitive calcium channel blocker, was measured using a new bioassay. \(\omega\)-CgTx was administered intraperitoneally (ip) to goldfish weighing approximately 1.6 g, and dose-related changes were observed over a 2-hr period. \(\omega\)CgTx induced time- and dose-dependent abnormal swimming behavior (ASB) and mortality. The antitoxin activity of the antiborlies was investigated in vivo by either ( l) preincubation of the antibody with w-CgTx at 4°C overnight, or (2) pretreatment with antibody, 30 min before \(\omega\)CgTx injection in a 10:1 antibody/\(\omega\)-CgTx molar ratio. The LD50 dose of \(\omega\)-CgTx in goldfish was 5 nmol/kg ip, and preincubation of monoclonal antibody (50 nmol/kg ip) with \(\omega\)-CgTx (5 nmol/kg ip) significantly (p < 0.05) reduced mortality. ASB, and toxicity time. The antitoxin activity of the monoclonal antiborlies evidenced in the goldfish bioassay was further tested in the conscious rat. In the rat, the increases in mean arterial pressure and heart rate induced by \(\omega\)-CgTx (0.03 nmol/rat icv) were significantly (p < 0.02 and p < 0.0 l, respectively) attenuated by preincubation of the toxin with the antibody (0.3 nmol/rat). We conclude that the goldfish bioassay provides a simple. accurate, and inexpensive in vivo model for the study of the toxicity of \(\omega\)CgTx
KW - Neurobiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63087
ER -
TY - JOUR
A1 - Wilhelm, Gernot
T1 - A Hurrian Letter from Tell Brak
N2 - No abstract available.
KW - Tell Brak
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85972
ER -
TY - JOUR
A1 - Schneider, Wolfgang
A1 - Sodian, Beate
T1 - A longitudinal study of young children's memory behavior and Performance in a sort-recall task
N2 - No abstract available
KW - Psychologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62169
ER -
TY - JOUR
A1 - Vortkamp, A.
A1 - Thias, U.
A1 - Gessler, Manfred
A1 - Rosenkranz, W.
A1 - Kroisel, P. M.
A1 - Tommerup, N.
A1 - Kruger, G.
A1 - Gotz, J.
A1 - Pelz, L.
A1 - Grzeschik, Karl-Heinz
T1 - A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p
N2 - No abstract available
KW - Biochemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59217
ER -
TY - JOUR
A1 - Peric, M.
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
T1 - Ab initio investigation of the vibronic structure of the C\(_2\)H spectrum Calculation of the hyperfine coupling constants for the three lowest lying electronic states
N2 - The hyperfine coupling constants (isotropic hfcc and four Cartesian components of the ani~ tropic tensor) are calculated for all three atoms of C\(_2\)H in its three lowest-lying electronic states at various molecu)ar geometries by means of the ab initio configuration interaction ( MRO.CI) method. The off-diagonal electronic matrix elements involving the two species ofthe A' symmetry are also computed. A diabatic transforrnation is perforrned Jeading to simple geometrical depen· dences of the hyperline coupling constants.
KW - Organische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58901
ER -
TY - JOUR
A1 - Peric, M.
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
T1 - Ab initio investigation of the vibronic structure of the C\(_2\)H spectrum Computation of the vibronically-averaged values for the Hyperfine Coupling Constants
N2 - The vibronically averaged values for tbe hyperfine coupling constants in the X\(^2 \sum\)-A\(^2 \Pi\) system of the ethynyl radical are computed by means of tbe ab initio metbod calculations. The results point at tbe importance of taking into account the coupling of a1l tbree electronic states in question ( I\(^2\)A', 2\(^2\)A', and 1\(^2\)A") for a reliable explanation of the available experimental findings. The mean values of the hfcc's for K = 0 and 1 levels in \(^{13}\)C\(_2\)H and \(^{13}\)C\(_2\)D in the energy range up to 6000 cm\(^{-1}\) are predicted.
KW - Organische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58915
ER -
TY - JOUR
A1 - Bringmann, Gerhard
A1 - Zagst, Rainer
A1 - Schöner, Bernd
A1 - Busse, Holger
A1 - Hemmerling, Martin
A1 - Burschka, Christian
T1 - Acetogenic Isoquinoline Alkaloids. XXIII. Structure of the Naphthyl Isoquinoline Alkaloid Dioncophylline A
N2 - No abstract available
KW - Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31331
ER -
TY - CHAP
A1 - Spielmann, W. S.
A1 - Arend, L. J.
A1 - Klotz, Karl-Norbert
A1 - Schwabe, U.
T1 - Adenosine control of the renal Collecting tubule: receptors and signaling
N2 - No abstract available.
KW - Adenosin
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86129
ER -
TY - CHAP
A1 - Shephard, S. E.
A1 - Meier, I.
A1 - Lutz, Werner K.
T1 - Alkylating potency of nitrosated amino acids and peptides
N2 - Tbe alkylating potency of unstable N-nitrosamino acids and N-nitrosopeptides was investigated in vitro using 4-(para-nitrobenzyl)pyridine (NBP) as nucleophile. Of the amino acids, Met and those with an aromatic side chain were the most potent. The relative overall alkylating potency was 23:10:5:4:2:1: for Trp, Met, His, 1)rr, Phe and Gly, respectively. The homo-dipeptides were much more potent than the amino acids, with relative potencies of 400:110:100:8:3:1, for Trp-Trp, l)T-'I)T, Met-Met, Asp-Asp, Phe-Phe and Gly, respectively. In the one-phase reaction system (in which NBP is already present durlog the nitrosation reaction at acidic pH), all amino acids tested showed a second-order reaction for nitrite. In the two-phase system (in which NBP is added only after bringing the nitrosation reaction mixture to neutrality), all amino acids tested except one again showed a second-order reaction for nitrite (Phe, His, Asp and the dipeptide artiticial sweetener aspartame); only Met under these conditions bad a reaction order of one for nitrite. This could mean that nitrosation of the side chain of Metproduces a second N-nitroso product which is relatively stable in acid but reacts with NBP under neutral conditions. In the human stomach, this side-chain nitrosation might become more important than the reactions at the primary amino group, firstly because of the greater stability of the product(s) in acid and secondly because of the tirst-order reaction rate for nitrite. A decrease in nitrite concentration from the millimolar concentrations ofthe in-vitro assay to the micromolar concentrations in the stomach reduces the reaction rate by a factor of 1000 for the side-chain nitrosation, whereas a million-fold reduction will be observed for nitrosation of the amino group.
KW - Aminosäuren
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86320
ER -
TY - JOUR
A1 - Bündgen, P.
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
T1 - An MRD-CI study of low-lying electronic states in CaF
N2 - Dipole moments and various spectroscopic constants of some low-lying electronic states of the CaF molecule have been calculated using the multireference single· and double-excitation configuration-interaction (MRD-CI) method. The electronic structure of the highly ionic molecule in various excited states can be explained in tenns of different polarisations of the mainly Cacentered valence electron in the field of the F\(^-\) anion. Plots of natural orbitals occupied by the valence electron in the different states give a qualitative picture of the charge distribution and provide a visualisation of the different polarisations of the valence electron in the various states. Comparisons with the electrostatic polarisation model ofTörring, Ernstand Kändler (TEK model) are made. The unknown A' \(^2 \Delta\) state is predicted to lie about 21200 cm\(^{-1}\) above the ground state.
KW - Organische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58880
ER -
TY - JOUR
A1 - Förnzler, Dorothee
A1 - Wittbrodt, Joachim
A1 - Schartl, M.anfred
T1 - Analysis of an esterase linked to a locus involved in the regulation of the melanoma oncogene and isolation of polymorphic marker sequences in Xiphophorus
N2 - Melanoma formation in Xiphophorus hybrids is mediated by a growth factor receptor tyrosine kinase oncogene encoded by the Tu locus. In the wild-type parental fish no tumors occur due to the activity of a locus that regulates the activity of the melanoma oncogene. Molecu/ar identification of this regulatory locus (R) requires a precise physical map of the chromosomal region. Therefore we studied esterase isozymes in Xiphophorus, two of which have been previously reported to be linked to locus R. We confinn that ES 1 is a distant marker for R ( approx. 30cM), and contrary to earlier studies, we show that this isozyme is present in all species of the genus and at similar activity Ievels in all organs tested. ES4, which has also been reported to be linked to R, was found to be a misclassification of liver ES1. In an attempt to identify markersthat bridge the large distance between ESl and R, we have generated DNA probes which are highly polymorphic. They will be useful in finding Iandmarks on a physical map of the R-containing chromosomal region.
KW - Physiologische Chemie
KW - Xiphophorus
KW - melanoma ; oncogene regulation ; esterase ; molecular marker sequences
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61726
ER -
TY - JOUR
A1 - Lück, P. Christian
A1 - Bender, Larisa
A1 - Ott, Manfred
A1 - Helbig, Jürgen H.
A1 - Hacker, Jörg
T1 - Analysis of Legionella pneumophila serogroup 6 strains isolated from a hospital warm water supply over a three-year period by using genomic long-range mapping techniques and monoclonal antibodies
N2 - Over a period of 3 years, Legionella pneumophila serogroup 6 strains were isolated from warm water outlets and dental units in the Dental Faculty and from the Surgery and Internal Medicine Clinics at the University of Dresden, Dresden, Germany. In the bacteriological unit of the above-mentioned facility, L. pneumophila serogroups 3 and 12 were grown frl,)m warm water specimens. The medical facilities are located in separate buildings connected with a ring pipe warm water system. All L. pneumophila serogroup 6 strains isolated from the warm water supply reacted with a serogroup-specific monoclonal antibody, but not with two other monoclonal antibodies which are subgroup specific, reacting with other serogroup 6 strains. The NolI genomic profiles obtained by pulsed-field gel electrophoresis of 25 serogroup 6 strains isolated from the Dental Faculty over a 3-year period, 1 isolate from the Internal Medicine Clinic, and 4 strains from the Surgery Clinic were identical. Furthermore, all these strains hybridized with a 3OO-kb NolI fragment when a legiolysin (lIy)-specific DNA probe was used. The NolI pattern, however, differed from those of six serogroup 6 strains of other origins, one serogroup 12 strain from the bacteriological unit, and another six unrelated strains of serogroups other than serogroup 6. L. pneumophila serogroup 6 strains which can be divided into only two subgroups by the use of monoclonal antibodies are differentiated in at least six Noli cleavage types obtained by pulsed-field electrophoresis.
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40392
ER -
TY - JOUR
A1 - Pfeffer, K.
A1 - Schoel, H.
A1 - Gulle, H.
A1 - Moll, Heidrun
A1 - Kromer, S.
A1 - Kaufmann, S. H. E.
A1 - Wagner, H.
T1 - Analysis of primary T cell responses to intact and fractionated microbial pathogens
N2 - Freshly isolated human T lymphocytes were tested for their response to mycobacteria, mycobacteriallysates, 2 dimensional (2D) PAGE separated mycobacteriallysates, leishmania and defined leishmanial antigen preparations. While,o T cells proliferated vigourously in the presence of mycobacteria and mycobacteria derived lysates, a significant stimulation from 2 D gel separated lysates was not detected. In addition '10 T cells failed to respond towards leishmania or leishmanial components. In the ab T cell compartment some donors, presumably according to their state of immunity against mycobacteria, responded to mycobacteria, mycobacterial lysates and 2 D gel separated mycobacterial lysates. Neither freshly isolated '10 T cells nor ab T cells from naive donors did mount a significant immune response against leishmania.
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46916
ER -
TY - JOUR
A1 - Ott, M.
A1 - Hacker, Jörg
T1 - Analysis of the variability of S fimbriae expression in an Escherichia coli pathogen.
N2 - The uropathogenic Escherichia coli wiJd..:type strain 536 produces S-fimbriae, P-related fimbriae and type I fimbriae. Using immuno-colony dot and ELISA techniques, variants were detected showing an increased degree of S-fimbrial production. It was demonstrated by itrtmunofluorescence microscopy that in noimal (wild-type) and hyperS- fimbriated E. coli populaiions non-fimbriated cells also · exist, and that the percentage of Sfinibrlated and non-fimbriated bacteria was roughly identica1 in either population. Hyper-Sfimbriated variants could be stably maintained. The transition from wild-type to hyper-S-fimbriation, which occurs spontaneously, is markedly higher than vice versa. Southern blot analysis of the S fimbrial adhesin (sfa) determinants of normal and hyper-fimbriated strains revealed no marked difference in the gene structure.
KW - Infektionsbiologie
KW - Escherichia coli
KW - S-fimbria
KW - Variability
KW - Expression
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59695
ER -
TY - JOUR
A1 - Dörje, F.
A1 - Wess, J.
A1 - Lambrecht, G.
A1 - Tacke, Reinhold
A1 - Mutschler, E.
A1 - Brann, M. R.
T1 - Antagonist binding profiles of five cloned human muscarinic receptor subtypes
N2 - A variety of muscarinic antagonists are currently used as tools to pharmacologically subclassify muscarinic receptors into M\(_1\), M\(_2\) and M\(_3\) subtypes. ln the present study I we have determined the affinity proflies of several of these antagonists at five cloned human muscarinic receptors (m1-m5) stably expressed in Chinesehamster ovary cells (CHO-K1). At all five receptorsl the (R)-enantiomers of trihexyphenidyl and hexbutinol displayed considerably higher affinities (up to 525-fold) than their corresponding (S)-isomers. The stereoselectivity ratios [inhibition constant( S)/inhibition constant(R)] for both pairs of enantiomers were lowest at m2 receptors, suggesting that less stringent configurational demands are made by this receptor subtype. The "M\(_1\)-selective" antagonist (R)-trihexyphenidyl displayed high affinities for m1 and m4 receptors. The "M\(_2\)-selective" antagonists himbacinel (±}-5, 11-dihydro-11-1[(2-[(dipropylamino)methyl]-1- piperidinyllethyl)amino]carbonyii-6H-pyrido(213-b)(1 ~4)benzodiazepine- 6-one (AF-DX 384)1 11-(14-[4-(diethylamino)butyl)-1-piperidinyll acetyl)-5~ 11-dihydro-6H-pyrido(2~3-b) (1~4)benzodiazepine-6-one (AQ-RA 741) and (+K11-(12-[(diethylamino)methyl]-1-piperidinyll acetyl)-5~ 11-di-hydro-6H-pyrido(2~3-b)(1,4)benzodiazepine-6-one (AF-OX 250; the (+)-enantiomer of AF-DX 116] exhibited high affinities for m2 and m41 intermediate affinities for m1 and m3 and low affinities for m5 receptors. This selectivity profile was most prominent for AQ-RA 7 41 I which displayed 195- and 129-fold higher affinities for m2 and m4 receptors than for mS receptors. The "M\(_3\)-selective" antagonist (±)-p-fluoro-hexahydro-sila-difenidol hydrochloride (pFHHsiD) exhibited high affinity for m1 I m3 and m4 receptors. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) bound with up to 7 -fold higher affinities to m1 I m31 m4 and m5 receptors than to m2 receptors. Although none of the tested antagonists showed more than 2-fold selectivity for one subtype over all other subtypes, each receptor displayed a unique antagonist binding profile.
KW - Anorganische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64113
ER -
TY - JOUR
A1 - Pauli, Paul
A1 - Marquardt, Christian
A1 - Hartl, Lydia
A1 - Nutzinger, Detlef O.
A1 - Hölzl, Rupert
A1 - Strian, Friedrich
T1 - Anxiety induced by cardiac perceptions in patients with panic attack: a field study
N2 - In panic disorder bodily sensations appear to play an important role as a trigger for anxiety. In our psychophysiological model of panic attacks we postulate the following vicious circle: individuals with panic attacks perceive even quite small increases in heart rate and interpret these changes as being catastrophic. This elicits anxiety and a further increase in heart rate. To evaluate this model we conducted a field study of 28 subjects with panic attacks and 20 healthy controls. A 24 hr ambulatory ECG was recorded and the subjects were instructed to report any cardiac perceptions during this period and to rate the anxiety elicited by these perceptions. The incidence of cardiac perceptions was about the same in both groups, but only subjects with panic attacks reported anxiety associated with such perceptions. Analysis of the ECGs revealed that in both groups heart rate accelerations preceded cardiac perceptions. Following cardiac perceptions, the healthy controls showed a heart rate deceleration, whereas the subjects with panic attacks had a further acceleration. This heart rate increase after cardiac perceptions was positively related to the level of anxiety elicited by the perceptions. These results provide clear evidence in support of the vicious circle model of panic attacks.
KW - Psychologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61334
ER -
TY - JOUR
A1 - Dabauvalle, Marie-Christine
A1 - Scheer, Ulrich
T1 - Assembly of nuclear pore complexes in Xenopus egg extract
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41194
ER -
TY - JOUR
A1 - Fischer, Dagmar
A1 - Weißenberger, Dieter
A1 - Scheer, Ulrich
T1 - Assigning functions to nucleolar structures
N2 - Nucleoli provide the fascinating possibility of linking morphologically distinct structures such as those seen in the electron microscope with biochemical f eatures of the formation and step wise maturation of ribosomes. Localization of proteins by immunocytochemistry and of rRNA genes and their transcripts by in situ hybridization has greatly improved our understanding of the structural-functional relationships of the nucleolus. The present review describes some recent results obtained by electron microscopic in situ hybridization and argues that this approach has the potential to correlate each step of the complex pre-rRNA maturation pathway with nucleolar structures. Evidence is accumulating that the nucleolus-specific U3 snRNPs (small nuclear ribonucleoprotein particles) participate in rRNA processing events, similar to the role played by the nucleoplasmic snRNPs in mRNA maturation. The intranucleolar distribution of U3 snRNA is consistent with the view that it is involved in both early and late stages of pre-rRNA processing.
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34258
ER -
TY - JOUR
A1 - Kraus, E.
A1 - Schneider-Schaulies, Sibylle
A1 - Miyasaka, M.
A1 - Tamatani, T.
A1 - Sedgwick, J.
T1 - Augmentation of major histocompatibility complex class I and ICAM-1 expression on glial cells following measles virus infection: evidence for the role of type-1 interferon
N2 - No abstract available
KW - Virologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62301
ER -
TY - JOUR
A1 - Waelbroeck, M.
A1 - Camus, J.
A1 - Tastenoy, M.
A1 - Mutschler, E.
A1 - Strohmann, C.
A1 - Tacke, Reinhold
A1 - Lambrecht, G.
A1 - Christophe, J.
T1 - Binding affinities of hexahydro-difenidol and hexahydro-sila-difenidol analogues at four muscarinic receptor subtypes: constitutional and stereochemical aspects
N2 - Hexahydro-sila-difenidoJ and eight analogues behaved as simple cumpetitive inhibitors of eHJN·methyl·scopoJamine binding to homogenates frorn human neuroblastoma NB-OK 1 cells (M\(_1\) sites), rat heart (M\(_2\) sites), rat pancreas (M\(_3\) sites), and rat striatum 'B' sites (M\(_4\) sites). Pyrrolidino- and hexamethyleneimino analogues showed the same sekctivity profile as the parent compound. Hexahydro-sila-difenidol methiodide and the methiodide of p-fluoro-hexahydro·sila-difenidol had a fügher affinity but a lower selectivity than the tertiary amines. Compounds containing a p·methoxy, p-chJoro or p-fluoro substituent in the phenyl ring of hexahydro-sila-difenidol showed a qualitative)y similar selectivity profile as the parent compound (i.e., M\(_1\)= M\(_3\) = M\(_4\) >M\(_2\) ), but up to 16-fold lower affinities. o-Methoxy-hexahydro-sila-difenidol has a lower affinity than hexahydro-sila-difeni.:!o! at the four binding sites. lts selectivity profile (M\(_4\) > M\(_1\), M\(_3\) > M\(_2\) ) was different from hexahydro-sila-difenidol. Replacement of the centrat silicon atom of hexahydro-sila-difenidol, p-fluoro-hexahydro-sila-difenidol and thdr quatemary (N-methylated) analogues by a carbon atom did not change their binding affinities significantly. The iour muscarinic receptors showed a higher affinity for the (R)- than for the (S)-enantiomers of hexahydro-difenidol, p-fluorohexahydro-difenidol and their methiodides. The stereoselectivity varied depending on the receptor subtype and drug considered.
KW - Anorganische Chemie
KW - Muscarinic receptor antagonists (selective)
KW - Hexahydro-sila-difenidol analogues
KW - p-Fluoro-hexahydro-sila-difenidol
KW - Stereoselectivity
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64128
ER -
TY - JOUR
A1 - Schroten, Horst
A1 - Wolske, Anja
A1 - Plogmann, Ricarda
A1 - Hanisch, Franz-Georg
A1 - Hacker, Jörg
A1 - Uhlenbrück, Gerhard
A1 - Wahn, Volker
T1 - Binding of cloned S-fimbriated E. coli to human buccal epithelial cells-different inhibition of binding by neonatal saliva and adult saliva.
N2 - Investigations were carried out on the adhesion of cloned S-fimbriated E. coli, labelled with fluoresceinisothiocyanate (FITC) to human buccal epithelial cells. Fluorescence microscopic analysis revealed binding of bacteria to 75-95% of epithelial cells. Inhibition experiments with fetuin, a 1-acid glycoprotein and N-acetyl neuraminic acid confirmed the specificity of bacterial binding to sialoglycoproteins. Further studies using saliva as an inhibitor resulted in a 4-5 times stronger binding inhibition by newborn saliva in comparison to adult saliva coinciding with a 4-5 times higher content of total N-acetyl neuraminic acid in samples of newborn saliva. In Western blot analysis sialoglycoprotein bands with a molecular weight >200 kD reacting with wheat germ agglutinin (WGA), were only identified in samples of newborn saliva. These bands are classified as mucins on account of molecular weight and staining. These data suggest that saliva mucins could represent a major defense mechanism against bacterial infections at a stage of ontogeny where the secretory IgAsystem is not yet developed.
N2 - bestätigt werden. Wurde als Inhibitor Speichel eingesetzt, so ergab sich für den Speichel Neugeborener eine 4-Sfach stärkere Inhibition als für Erwachsenenspeichel Parallel dazu ergab die Untersuchung der Speichelproben für Neugeborene einen 4-Sfachen höheren. Die Adhäsion clonierter, Fluoresceinisothiocyanat (FITC)-markierter, S-Fimbrien tragender E. coli an menschliche Mundschleimhautzellen wurde untersucht. Die fluoreszenzmikroskopische Auswertung ergab, daß 75-95% der Schleimhautzellen Bakterien gebunden hatten. Die Spezifität der Bindung der Bakterien an Sialoglykoproteine konnte durch Inhibitionsexperimente mit Fetuin, saurem arGlykoprotein und N-acetyl-Neuraminsäure Gehalt an Gesamt-N-acetyl-Neuraminsäure. In Westerohlot Analysen konnten nur in Proben nativen Speichels Neugeborener mit Wheat Germ Agglutinin (WGA) reagierende Sialoglykoproteinbanden mit Molekülmassen > 200 kD identifiziert werden, die aufgrund ihres Molekulargewichtes und Färbeverhaltens der Klasse der Mucine zuzuordnen sind. Speichelmucine können einen wichtigen Abwehrmechanismus gegen Infektionen in einer Periode der kindlichen Entwicklung darstellen, in der das sekretorische IgA-System noch nicht voll entwickelt ist.
KW - Escherichia coli
KW - Speichel
KW - Neugeborenes
KW - Erwachsener
KW - Adhäsion
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86291
ER -
TY - JOUR
A1 - van Calker, D.
A1 - Steber, R.
A1 - Klotz, Karl-Norbert
A1 - Greil, W.
T1 - Carbamazepine distinguishes between adenosine receptors that mediate different second messenger responses
N2 - The mechanism of the therapeutic and prophylactic effects of carbamazepine (CBZ) in affective psychoses is unknown but may in part be related to the potent competitive interaction of CBZ with adenosine-binding sites in the brain. The antioonvulsant and sedative properties of CBZ are reminiscent of the effects evoked by adenosine-agonists and contrast sharply with the opposite aclions of adenosine-antagonists like caffeine. However. indirect evidence suggests an antagonist- rather than an agonist-like activity of CBZ at adenosi11e-receptors. We have used various model systems, in which adenosine receptor subtypes mediate different second messenger-responses, to investigate this apparent paradox. CBZ was found to antagonize the A\(_1\) receptor-mediated inhibition of cydic AMP accumulation in cultured astroblasts and in GH3-cells. Furthermore, CBZ also inhibits the adenosine-induced increase in the level of cyclic AMP in cultured astroblasts, which is mediated by low-affinity A\(_{2b}\)-receptors. ln contrast, CBZ does not block the inhibition elicited by adenosine-agonists of the agonist-induced increased formation of inositolphosphates in human neutrophils, which is mediated by high-affinity A\(_{2a}\)-receptors. The specific antagonism by CBZ of A\(_1\)- but not of high-affinity A\(_{2a}\)-receptors was further supported by binding experiments using rat brain membranes. These results suggest tbat the paradox of CBZ's antagonistic effects at adenosine-receptors might be at least partially reconciled by a selective antagonistic action of CBZ at A\(_1\)recertors but not at high-affinity A\(_{2a}\)-receptors.
KW - Toxikologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60392
ER -
TY - JOUR
A1 - Stopper, Helga
A1 - Metzler, M.
T1 - Carcinogenic oestrogens induce respiration deficiency mutation in yeast
N2 - In addition to hormonal activity, genetic darnage has been proposed as an important factor in oestrogen-mediated carcinogenesis. However, as short-term tests for oestrogens usually fail to show DNA mutations, lesions other than dassie nuclear DNA mutation have to be considered. Oestrogeninduced mitochondrial darnage was studied in the yeast Saccharomyces cerevisiae. Stilbene-type, but not steroidal, oestrogens were found to induce respiration-dcficient petite mutation. The effect was inversely correlated with cytotoxicity and required aromatic hydroxyl groups at the stilbene molecule. It only occurred under growth conditions and apparently was not due to the A TPase inhibitory qualities of stilbene oestrogens. Other studies have shown that petite mutation clones, which can be induced by a variety of substances, contain altered mitochondrial DNA. The mechanism of petite mutation induction might be important in tumorigenesis by also acting on nuclear DNA or facilitating carcinogenesis by disturbance of mitochondrial function.
KW - Toxikologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63466
ER -
TY - JOUR
A1 - Vonhof, S.
A1 - Sirén, Anna-Leena
A1 - Feuerstein, G.
T1 - Central ventilatory effects of thyrotropin-releasing hormone in the conscious rat
N2 - Thyrotropin-releasing hormonewas shown to exert potent ventilatory effects after centrat administration. These data, however, were derived from studies using anesthetized animal preparations. Since TRH elicits strong arousal reactions, the observed ventilatory effects of TRH under anesthesia may have been due to nonspecific reduction in the anesthetic state of the animals. In order to clarify the extent to which the reversal of anesthesia may change ventilatory parameters after TRH application, we investigated the effect of TRH on Ventilation rate, relative tidal volume, relative respiratory minute volume, CO\(_2\) production CO\(_2\) consumption, and locomotor activity in the conscious, unrestrained rat. Intracerebroventricular application of TRH induced a dose-dependent, sustained increase in ventilation rate, relative tidal volume, and relative respiratory minute volume of maximally 128%, 890%, and 235%, respectively. In addition, CO\(_2\) production and O\(_2\) consumption were elevated by 4.6 and 11.7 fold, whiJe no significant changes in locomotor activity were observed. The results suggest that TRH stimulates ventilation by a mechanism independent of its analeptic properties.
KW - Neurobiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63075
ER -
TY - JOUR
A1 - Dandekar, Thomas
A1 - Argos, Patrick
T1 - Chaperonin-mediated protein folding at the surface of groEL through a "molten globule" intermediate
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29939
ER -
TY - JOUR
A1 - Gonzalez-Calero, G.
A1 - Cubero, A.
A1 - Klotz, Karl-Norbert
T1 - Characterization and photoaffinity labeling of A1 adenosine receptors in coated visicles form bovine brain
N2 - The antagonist (3 II ) DPCPX exhi bitcd a Kd of 0. 4 nM at coalcd vcsicles from bovine brain. Agonist compelition for ( 3 11) DPCPX bind in~ revcaled two affini ty slales for gonists. The pholoaffinity probe I25 I -AHPIA specifically labelled a band with a molecular weight of 35 Kd.
KW - Pharmakologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86004
ER -
TY - JOUR
A1 - Wintermeyer, E.
A1 - Rdest, U.
A1 - Ludwig, B.
A1 - Debes, A.
A1 - Hacker, Jörg
T1 - Characterization of legiolysin (lly); responsible for hemolytic activity, colour production and fluorescence of Legionella pneumophila
N2 - No abstract available
KW - Infektionsbiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59706
ER -
TY - JOUR
A1 - Rettinger, Klaus
A1 - Burschka, Christian
A1 - Scheeben, Peter
A1 - Fuchs, Heike
A1 - Mosandl, Armin
T1 - Chiral 2-alkylbranched acids, esters and alcohols. Preparation and stereospecific flavour evaluation
N2 - Racemic 2-alkylbranched acids are transformed to diastereomeric derivatives with (S)-2-hydroxy-3-phenylpropionic acid-N-methylamide or (S)-(-)-l-phenylethylamine and separated by liquid chromatography to pure diastereoisomers, which are subsequently hydrolyzed to yield optically pure acids. Enantiomeric alcohols are generated by LiAlH4-reduction of the corresponding acids, esters are synthesized by different methods. The odour impression of the enantiomeric compounds is investigated.
KW - Säure
KW - Ester
KW - Alkohol
KW - 2-alkylbranched acids
KW - esters and alcohols
KW - flavour substances
KW - chirality and odour
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31898
ER -
TY - JOUR
A1 - Haas, Albert
A1 - Brehm, Klaus
A1 - Kreft, Jürgen
A1 - Goebel, Werner
T1 - Cloning, characterization, and expression in Escherichia coli of a gene encoding Listeria seeligeri catalase, a bacterial enzyme highly homologous to mammalian catalases
N2 - A gene coding for catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) of the grain-positive bacterium Listeria seeligeri was cloned from a plasmid library of EcoRI-digested chromosomal DNA, with Escherichia coli DHSa as a host. The recombinant catalase was expressed in E. coli to an enzymatic activity approximately SO times that of the combined E. coli catalases. The nucleutide sequence was determined, and the deduced amino acid sequence revealed 43.2% amino acid sequence identity between bovine liver catalase and L. seeligeri catalase. Most of the amino acid residues which are involved in catalytic activity, the formation of the active center accession channel, and heme binding in bovine liver catalase were also present in L. seeligeri catalase at the corresponding positions. The recombinant protein contained 488 amino acid residues and had a calculated molecular weight of 55,869. The predicted isoelectric point was 5.0. Enzymatic and genetic analyses showed that there is most probably a single catalase of this type in L. seeligeri. A perfect 21-bp inverted repeat, which was highly homologous to previously reported binding sequences of the Fur (ferric uptake regulon) protein of E. coli, was detected next to the putative promoter region of tbe L. seeligeri catalase gene.
KW - Biologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60536
ER -
TY - JOUR
A1 - Ludwig, B.
A1 - Schmid, A.
A1 - Marre, R.
A1 - Hacker, Jörg
T1 - Cloning, genetic analysis and nucleotide sequence of a determinant coding for a 19 kd peptidoglycan-associated protein (Ppl) of Legionella pneumophila
N2 - A genomic library of Legionello pneumophihz, the causative agent of Legionnaires disease in humans, was constructed in Escherichill coli K-12, and the recombinant clones were screened by immuno-colony blots with im antiserum raised against heat-killed L. pneumophilo. Twenty-three clones coding for a LegioneUa-specific protein of 19 kDa were isolated. The 19-kDa protein, which represents an outer membrane protein, was found tobe associated with the peptidoglycan layer bothin L. pneumophilo andin the recombinant E. coli clones. This was shown by electrophoresis and Western immunoblot analysis of bacterial cell membrane fractions witb a monospecific polyclonal 19-kDa protein-specific antiserum. Tbe protein was termed peptidoglycan-associated protein of L. pneumophilo (Ppl). The corresponding genetic determinant, ppl, was subcloned on a 1.8-kb Clol fragment. DNA sequence studies revealed that two open reading frames, pplA and pplB, coding for putative proteins of 18~9 and 16.8 kDa, respectively, were located on the Clol fragment. Exonuclease 111 digestion studies confirmed tbat pplA is the gene coding for the peptidoglycan.;.associated 19-kDa protein of L. pneumophilo. The amino acid sequence of PpiA exhibits a high degree of homology to the sequences of the Pal Iipoproteins of E. coli K-12 and liaemophilus injluenvze.
KW - Infektionsbiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59721
ER -
TY - JOUR
A1 - Klotz, Karl-Norbert
A1 - Vogt, H.
A1 - Tawfik-Schlieper, H.
T1 - Comparison of A\(_1\) adenosine receptors in brain from different species by radioligand binding and photoaffinity labelling
N2 - Radioligand binding to A\(_1\) adenosine receptors at brain membranes from seven species was investigated. The antagonist 8-cyclopentyl-1 ,3-[\(^3\)H]dipropylxanthine ([\(^3\)H]DPCPX) bound with affinities between 0.17 nM in sheep brain and 2.1 nM in guinea pig brain. Competition of several antagonists for [\(^3\)H]DPCPX binding showed that the most potent compounds were DPCPX with K\(_i\) values of 0.05 nM in bovine brain and 1.1 nM in guinea pig brain and xanthine amine congener (XAC) with K\(_i\) values of 0.03 nM in bovine brain and 5.5 nM in guinea pig brain. The differences in affinity of the agonist radio Iigand 2-chloro-N\(^6\) -[\(^3\)H]cyclopen tyladenosine ([\(^3\)H]CCP A) were less pronounced, rauging from a K\(_D\) value of 0.12 nM (hamster brain) to 0.42 nM (guinea pig brain). Agonist competition for [\(^3\)H]DPCPX binding of photoaffinity labelling, however, exhibited marked species differences. N-Ethylcarboxamidoadenosine (NECA) and S-N\(^6\)-phenylisopropyladenosine (S-PIA) showed 20 to 25-fold different K\(_D\) values in different species. NECA had a particularly high affinity in guinea pig brain and was only two-fold less potent than R-PIA. Thus, the difference from the "classical" A\(_1\) receptor profile (R-PIA > -NECA > S-PIA) is not sufficient to speculate that A\(_1\) receptor subtypes may exist that are coupled to different effector systems. Our data show that these difference can easily be explained by species differences.
KW - Toxikologie
KW - A1 adenosine receptors
KW - Species differences
KW - Radioligand binding
KW - Photoaffinity labelling
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60388
ER -
TY - JOUR
A1 - Hannig, Gerhard
A1 - Ottilie, Sabine
A1 - Schartl, Manfred
T1 - Conservation of structure and expression of the c-yes and fyn genes in lower vertebrates
N2 - The src-gene family in mammals and birds consists of 9 closely related protein tyrosine kinases. We have cloned the c-yes and fyn bomologues of the src-family from the teleost fish Xiphophorus helleri. Both genes show a high degree of sequence conservation and exhibit all structural motifs diagnostic for functional src-like protein tyrosine kinases. Sequence comparisons revealed three domains (exon 2, exons 3--6, exons 7-12) which evolve at different rates. Both genes exhibit an identical expression pattern, with preferential expression in neural tissues. No transcripts of c-yes were found in liver wbich is contrary to the situation in higher vertebrales. In malignant melanoma, elevated Ieveis of c-yes andfyn were detected indicating a possible function during secondary steps of tumor progression for src-related tyrosine kinases.
KW - Konservierung
KW - Gen
KW - Niedere Wirbeltiere
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86723
ER -
TY - JOUR
A1 - Wu, Y.S.
A1 - Becker, Charles R.
A1 - Waag, A.
A1 - Kraus, M. M.
A1 - Bicknell-Tassius, R. N.
A1 - Landwehr, G.
T1 - Correlation of the Cd-to-Te ratio on CdTe surfaces with the surface structure
N2 - We report here that reconstruction on (100), (1lIlA, and (1l1lB CdTe surfaces is either C(2X2), (2X2), and (l X I) or (2X I), (l X I), and (l X I) when they are Cd or Te stabilized, respectively. There is a mixed region between Cd and Te stabilization in which the reflected high-energy electron-diffraction (RHEED) patterns contain characteristics of both Cd- and Te-stabilized surfaces. We have also found that the Cd-to-Te ratio of the x-ray photoelectron intensities of their 3d\(_{3/ 2}\) core levels is about 20% larger for a Cd-stabilized (1lIlA, (1lIlB, or (100) CdTe surface than for a Te-stabilized one. According to a simple model calculation, which was normalized by means of the photoelectron intensity ratio of a Cd-stabilized (lll)A and aTe-stabilized (1l1lB CdTe surface, the experimental data for CdTe surfaces can be explained by a linear dependence of the photoelectron-intensity ratio on the fraction of Cd in the uppermost monatomic layer. This surface composition can be correlated with the surface structure, i.e., the corresponding RHEED patterns. This correlation can in turn be employed to determine Te and Cd evaporation rates. The Te reevaporation rate is increasingly slower for the Te-stabilized (Ill) A, (l1l)B, and (100) surfaces, while the opposite is true for Cd from Cd-stabilized (Ill) A and (Ill)B surfaces. In addition, Te is much more easily evaporated from all the investigated surfaces than is Cd, if the substrate is kept at normal molecular-beam-epitaxy growth temperatures ranging from 2oo·C to 300 ·C.
KW - Festkörperphysik
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-37789
SN - 0163-1829
ER -
TY - JOUR
A1 - Berger, Susanne
A1 - Ellersiek, Ulrike
A1 - Steinmüller, Klaus
T1 - Cyanobacteria contain a mitochrondrial complex I-homologous NADH-dehydrogenase
N2 - Thylakoid and cytoplasmic membranes of the cyanobacterium Syncchocystis sp. PCC 6803 were purified by sucrose gradient centrifugation. Both membranes oxidize NADH in a rotenone-sensitive reaction. Antibodies prepared against psbG/ndhKand ndhJ fusion proteins detect the corresponding polypeptides in both membrane preparations. This demonstrates that a NADH-dehydrogenase, homologous to the mitochondrial NADHubiquinone-oxidoreductase (complex I of the respiratory chain) is present in cyanobacteria, The NADH-dehydrogenase can be solubilized with the detergent /-D-dodecylmaltoside. Sedimentation analysis of the solubilized enzyme on a sucrose gradient indicates that it is a multisubunit protein complex.
KW - Respiratory chain
KW - NADH-dehydrogenase
KW - Cyanobacteria
KW - Synechocystis 6803
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31223
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Mahner, K.
A1 - Strohmann, C.
A1 - Forth, B.
A1 - Mutschler, E.
A1 - Friebe, T.
A1 - Lambrecht, G.
T1 - Cyclohexyl(4-fluorophenyl)(3-piperidinopropyl)silanol (p-fluoro-hexahydro-sila-difenidol, p-F-HHSiD) and derivatives: synthesis and antimuscarinic properties
N2 - Four different syntheses of the potent and selective muscanruc antagonist cyclohexyl( 4- fluorophenyl)(3-piperidinopropyl)silanol ( p-fluoro-hexahydro-sila-difenidol, p-F-HHSiD (2b); isolated as hydrochloride 2b· HCl) are described (starting materials: (CH\(_3\)O)\(_2\)SiCH\(_2\)CH\(_2\)CH\(_2\)Cl and Si(OCH\(_3\))\(_4\) ). In addition, the synthesis of the corresponding carbon analogue p-fluoro-hexahydro-difenidol ( p-F-HHD (2a); isolated as 2a· HCI) and the syntheses of three p-F-HHSiD derivatives (3-5), with a modified cyclic amino group, are reported (3: piperidinojpyrrolidino exchange, isolated as 3· HCI; 4: piperidinoj hexamethylenimino exchange, isolated as 4 · HCl; 5: quaternization of 2b with methyl iodide). The chiral compounds 2a, 2b, 3, 4 and 5 were prepared as racemates. In functional pharmacological studies, 3-5 behaved as simple competitive antagonists at musearlnie Ml receptors in rabbit vas deferens, M2 receptors in guinea-pig atria, and M3 receptors in guinea-pig ileal smooth rnuscle. The pyrrolidino (3) and hexamethylenimino (4) analogues of the parent drug p-F-HHSiD (2b) displayed the highest affinity for Ml and M3 receptors (pA\(_2\) values: 7.0-7.4) but exhibited lower affinity for cardiac M2 receptors (pA\(_2\) : 5.9 and 6.0). Their affinity profile (Ml- M3 > M2) is different from that of p-F-HHSiD (2b) (M3 > Ml > M2), but qualitatively very similar tothat of p-F-HHD (2a). The methiodide 5 exhibited the highest affinity for Ml receptors (pA\(_2\) : 8.5) but lower affinity for M2 and M3 receptors by factors of 5.6 and 3.6, respectively.
KW - Anorganische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64162
ER -
TY - JOUR
A1 - Merz, H.
A1 - Fliedner, A.
A1 - Orscheschek, K.
A1 - Binder, T.
A1 - Sebald, Walter
A1 - Müller-Hermelink, H. K.
A1 - Feller, A. C.
T1 - Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth
N2 - No abstract available
KW - Biochemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62483
ER -
TY - JOUR
A1 - Bender, L.
A1 - Ott, M.
A1 - Debes, A.
A1 - Rdest, U.
A1 - Heesemann, J.
A1 - Hacker, Jörg
T1 - Distribution, expression and long range mapping of legiolysin gene (lly) specific DNA sequences in Legionellae
N2 - The legiolysin gene (lly) cloned from Legionella pneumophila Philadelphia 1 confers the phenotypes of hemolysis and browning of the culture medium. An internal Uy-specific DNA probe was used in Southern hybridizations for the detection of Uy-specific DNA in the genomes of legioneUae and other gram-negative pathogenic bacteria. Under conditi9ns of high stringency, tlie Uy DNA probe specifically reacted with DNA fragments fr9m L. pneumophiüz isolates; by reducing stringency, hybridization was also observed for all other Legionella strains tested. No hybridization occurred with DNAs isolated from bact~ria of other genera. The Uy genewas mapped by pulsed-field gel electrophoresis to the respective genomic Notl fragments of Legionelltz isolates. By using antilegiolysin monospecific polyclonal antibodies in Western blots (immunoblots), Lly proteins could be detected only in L. pneumophila isolates.
KW - Infektionsbiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59744
ER -
TY - JOUR
A1 - Ohgaki, H.
A1 - Ludeke, B. I.
A1 - Meier, I.
A1 - Kleihues, P.
A1 - Lutz, Werner K.
A1 - Schlatter, C.
T1 - DNA methylation in the digestive tract of F344 rats during chronic exposure to N-methyl-N-nitrosourea
N2 - The formation of \(O^6\)-methyldeoxyguanosine (\(O^6\)-MedGuo) was determined by an immuno-slot-blot assay in DNA of various tissues of F344 rats exposed to N-methyl-N-nitrosourea (MNU) in the drinking waterat 400 ppm for 2 weeks. Although the pyloric region of the glandular stomach is a target organ under these experimental conditions, the extent of DNA methylation was highest in the forestomach (185 \(\mu\)mol \(O^6\)-MedGuojmol guanine). Fundus (91 J.!moljmol guanine) and pylorus (105 J.!moljmol guanine) of the glandular stomach, oesophagus (124 \(\mu\)mol/mol guanine) and duodenum (109 )lmoljmol guanine) showed lower Ievels of \(O^6\) - MedGuo but differed little between each other. Thus, no correlation was observed between target organ specificity and the extent of DNA methylation. This is in contrast to the gastric carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), which preferentially alkylates DNA of the pylorus, the main site of induction of gastric carcinomas by this chemical. In contrast to MNU, the nonenzymic decomposition of MNNG is accelerated by thiol compounds (reduced glutathione, L-cysteine), which are present at much higher concentrations in the glandular stomach than in the forestomach and oesophagus. During chronic exposure to MNNG (80 ppm), mucosal cells immunoreactive to 0 6-MedGuo are limited to the luminal surface [Kobori et al. (1988) Carcinogenesis 9:2271-2274]. Although MNU (400 ppm) produced similar Ievels of \(O^6\)-MedGuo in the pylorus, no cells containing methylpurines were detectable by immunohistochemistry, suggesting a more uniform methylation of mucosal cells by MNU than by MNNG. After a single oral dose of MNU (90 mg/kg) cells containing methylpurines were unequivocally identified using antibodies to \(O^6\)-MedGuo and the imidazole-ring-opened product of 7-methyldeoxyguanosine. In the gastric fundus, their distribution was similar to those methylated by exposure to MNNG, whereas the pyloric region contained immunoreactive cells also in the deeper mucosallayers. After a 2-week MNU treatment, the rate of cell proliferation, as determined by bromodeoxyuridine immunoreactivity, was only slightly enhanced in the oesophagus andin the fundus, but markedly in the forestomach and the pyloric region of the glandular stomach. lt is concluded that the overall extent of DNA methylation, the distribution of alkylated cells within the mucosa and the proliferative response all contribute to the organ-specific carcinogenicity of MNU.
KW - Toxikologie
KW - Gastric carcinogenesis
KW - N-methyl-N-nitrosourea
KW - DNA methylation
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60759
ER -
TY - JOUR
A1 - Schneider, Wolfgang
T1 - Domain-specific knowledge and memory Performance
N2 - No abstract available
KW - Psychologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-50494
ER -
TY - JOUR
A1 - Lutz, Werner K.
T1 - Dose-response relationship for chemical carcinogenesis by genotoxic agents
N2 - No abstract available
KW - Toxikologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60766
ER -
TY - CHAP
A1 - Lutz, Werner K.
T1 - Dose-response relationships in chemical carcinogenesis: from DNA adducts to tumor incidence
N2 - Mechanistic possibilitles responsible for nonlinear shapes of the dose-response relationship in chemical carcinogenesis are discussed. (i) Induction and saturation of enzymatic activation and detoxification processes and of DNA repair affect the relationship between dose and steady-state DNA adduct Ievel; (ii) The fixation of DNA adducts in the form of mutations is accelerated by stimulation of the cell division, for Jnstance due to regenerative hyperplasia at cytotoxic dose Ievels; (iii) The rate of tumor formation results from a superposition of the rates of the individual steps. It can become exponential with dose if more than one step is accelerated by the DNA damage exerted by the genotoxic carcinogen. The strongly sigmoidal shapes often observed for dose-tumor incidence relationships in animal bioassays supports this analysis. A power of four for the dose in the su~linear part of the curve is the maximum observed (formaldehyde). In contrast to animal experiments, epidemiological data ln humans rarely show a slgnificant deviation from linearity. The discrepancy might be explained by the fact that a I arge nu mber of genes contribute to the overall sensitivity of an individual and to the respective heterogeneity within the human population. Mechanistic nonlinearities are flattened out in the presence of genetic and life-style factors which affect the sensitivity for the development of cancer. For a risk assessment, linear extrapolation from the high-dose lncidence to the spontaneaus rate can therefore be approprlate in a heterogeneous population even if the mechanism of action would result in a nonlinear shape of the dose-response curve in a homogeneaus population.
KW - aflatoxin B1
KW - 2-acetylaminofluorene
KW - DNA
KW - adduct
KW - covalent
KW - binding
KW - carcinogen
KW - dose
KW - extrapolation
KW - individual
KW - susceptibility
KW - heterogeneous population
KW - risk
KW - tumour
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-71625
ER -
TY - JOUR
A1 - Schneider-Schaulies, Jürgen
A1 - Kirchhoff, F.
A1 - Archelos, J.
A1 - Schachner, M.
T1 - Downregulation of Myelin Associated Glycoprotein (MAG) on Schwann cells by interferon-gamma and tumor necrosis factor-alpha affects neurite outgrowth
N2 - To investigate the influence of inflammatory cytokines on the potential of peripheral nerves to regenerate, we analyzed the effect of interferon-y (lFN-y) and tumor necrosis factor-a (TNF-a) on the ability of immortalized Schwann cells to mediate outgrowth of neurites from primary DRG neurons. We found that IFN-y and TNF-a synergistically inhibited the neurite outgrowth-promoting properties of the Schwann cells by spedfically dowllregulating myelin-associated glycoprotein (MAG) at the levels of mRNA and cell surface protein by approximately 60%. Antibodies to MAG inhibited the outgrowth of neurites on Schwann cells to the same extent as treatment with the two cytokines. Since MAG appears to be involved in both neurite outgrowth and myelination, our findings may provide evidence for a mechanism, by wh ich inflammatory cytokines interfere with Schwann cell-neuron interactions.
KW - Immunologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54850
ER -
TY - JOUR
A1 - Sendtner, Michael
A1 - Arakawa, Yoshihiro
A1 - Stöckli, Kurt A.
A1 - Kreutzberg, Georg W.
A1 - Thoenen, Hans
T1 - Effect of ciliary neurotrophic factor (CNTF) on motoneuron survival
N2 - We have demonstrated that the extensive degeneration of motoneurons in the rat facial nucleus after transection of the facial nerve in newborn rats can be prevented by local ciliary neurotrophic factor (CNTF) administration. CNTF differs distinctly from known neurotrophic molecules such as NGF, BDNF and NT-3 in both its molecular characteristics (CNTF is a cytosolic rather than a secretory molecule) and its broad spectrum of biological activities. CNTF is expressed selectively by Schwann cells and astrocytes of the peripheral and central nervous system, respectively, but not by target tissues of the great variety of CNTF -responsive neurons. CNTF mRNA is not detectable by Northern blot or PCR analysis during embryonic development and immediately after birth. However, during the second post-natal week, a more than 30-fold increase in CNTF mRNA and pro tein occurs in the sciatic nerve. Since the period of low CNTF levels in peripheral nerves coincides with that of high vulnerability of motoneurons (i.e. axonallesion results in degeneration of motoneuron cell bodies), insufficient availability of CNTF may be the reason for the rate of lesioninduced cell death of early post-natal motoneurons. Highly enriched embryonic chick motoneurons in culture are supported at survival rates higher than 60% by CNTF, even in single cell cultures, indicating that CNTF acts directly on motoneurons. In contrast to CNTF, the members of the neurotrophin gene family (NGF, BDNF and NT-3) do not support the survival of motoneurons in culture. However, aFGF and bFGF show distinct survival activities which are additive to those of CNTF, resulting in the survival of virtually all motoneurons cultured in the presence of CNTF and bFGF.
KW - motoneurons
KW - ciliary neurotrophic factor
KW - CNTF
KW - nerve lesion
KW - rat
KW - chick
KW - neurotrophic factor
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33048
ER -
TY - JOUR
A1 - Baertsch, A.
A1 - Lutz, Werner K.
A1 - Schlatter, C.
T1 - Effect of inhalation exposure regimen on DNA binding potency of 1,2-dichloroethane in the rat
N2 - 1 ,2-Dichloroethane (DCE) was reported to be carcinogenic in rats in a long-tenn bioassay using gavage in com oil (24 and 48 mg/kg/day), but not by inhalation (up to 150-250 ppm, 7 h/day, 5 days/week). The daily dose metabolized was similar in the two experiments. In order to address this discrepancy, the genotoxicity of DCE was investigated in vivo under different exposure conditions. Fernale F-344 rats (183-188 g) were exposed to [1,2-14C]DCE in a closed inhalation chamber to either a low, constant concentration (0.3 mg/l = 80 ppm for 4 h) or to a peak concentration (up to 18 mg/1 = 4400 ppm) for a few minutes. After 12 h in the chamber, the dose metabolized under the two conditions was 34 mg/kg and 140 mg/k:g. DNA was isolated from liver and lung and was purified to constant specific radioactivity. DNA was enzymaticaBy hydrolyzed to the 3' -nucleotides which were separated by reverse phase HPLC. Most radioactivity eluted without detectable or with little optical density' indicating that the major part of the DNA radioactivity was due to covalent binding of the test compound. The Ievel of DNA adducts was expressed in the dose-nonnalized units ofthe Covalent Binding Index, CBI = f.Lmol adduct per mol DNA nucleotide/ mmol DCE per kg body wt. In liver DNA, the different exposure regimens resulted in markedly different CBI values of 1.8 and 69, for "constant-low" and ''peak" DCE exposure Ievels. In the Jung, the respective values were 0.9 and 31. It is concluded that the DNA darnage by DCE depends upon the concentration-time profile and that the carcinogenic potency determined in the gavage study should not be used for low-Ievel inhalation exposure.
KW - Toxikologie
KW - 1
KW - 2-Dichloroethane
KW - Carcinogens
KW - DNA
KW - binding
KW - Rat
KW - Inhalation
KW - Dose response
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60743
ER -
TY - JOUR
A1 - Strohmann, C.
A1 - Bauerecker, S.
A1 - Cammenga, H. K.
A1 - Jones, P. G.
A1 - Mutschler, E.
A1 - Lambrecht, G.
A1 - Tacke, Reinhold
T1 - Enantiomers of the muscarinic antagonist 1-cyclohexyl-1-(4-fluorophenyl)-4-piperidino-1-butanol (p-fluoro-hexahydro-difenidol): synthesis, absolute configuration, and enantiomeric purity
N2 - The enantiomers of the antimuscarinic agent 1-cyclohexyl-1- (4-fluorophenyl)-4-piperidino-1-butanol [(R)- and (S)-p-fluorohexahydro- difenidol] ((R)- and (S)-2a] and their methiodides (R)- 3 and (S)-3 were prepared with high enantiomeric purity. (R)- 2a and (S)-2a (isolated as hydrochlorides) were obtained by catalytic hydrogenation (Pd/C contact) of the corresponding enantiomers of 1-cyclohexyl-1-( 4-fl uorophen yl)-4-piperidino- 2-butyn-1-ol [(R)- and (S)-4]. Reaction of (R)-2a and (S)-2a with rnethyl iodide led to (R)-3 and (S)-3, respectively. The unsaturated precursors (R)- and (S}-4 (enantiorneric purity ~ 99.80 and ~99.94% e.e.; calorimetric analysis) were prepared by res-sepaolution of rac-4 [available from 4-FC\(_6\)H\(_4\)C(O)C\(_6\)H\(_{11}\) by reaction with LiC ~ CCH\(_2\)NC\(_5\)H\(_{10}\)] using (R)- and (S)-mandelic acid as resolving agents. The absolute configurations of the (R) and (S) enantiomers of 2a, 3, and 4 were determined by an X-ray crystal-structure analysis of (S)-5, the methiodide of (S)-4. (R)- 2a and (R)-3 exhibit a higher affinity for muscarinic M1, M2, M3, and M4 receptors (by up to two orders of magnitude) than their corresponding antipodes (S)-2a and (S)-3, the degree of stereoselectivity depending on the receptor subtype involved. (R)-2a represents a useful tool for rnuscarinic receptor research (affinity profile: M1 ~ M3 ~ M4 > M2).
KW - Anorganische Chemie
KW - Difenidol
KW - p-fluoro-hexahydro-
KW - enantiomers of / Muscarinic receptors
KW - subtypes of
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64144
ER -
TY - JOUR
A1 - Parkkinen, Jaakko
A1 - Hacker, Jörg
A1 - Korhonen, Timo K.
T1 - Enhancement of tissue plasminogen activator-catalyzed plasminogen activation by Escherichia coli S fimbriae associated with neonatal septicaemia and meningitis.
N2 - The effect of Escherichia coli strains isolated from blood and cerebrospinal fluid of septic infants on plasminogen activation was studied. These strains typically carry a filamentous surface protein, S fimbria, that has formerly been shown to bind to endothelial cells and interact with plasminogen. The bacteria effectively promoted plasminogen activation by tissue plasminogen activator (t-PA) which was inhibited by e-aminocaproic acid. A recombinant strain expressing S fimbriae accelerated t-PAcatalyzed plasminogen activation to a similar extent as did the wild-type strains whereas the nonfimbriate recipient strain had no effect. After incubation with t-PA and plasminogen, the S-fimbriate strain displayed bacterium-bound plasmin activity whereas the nonfimbriate strain did not. Bacterium-associated plasmin generation was also observed with a strain expressing mutagenized S fimbriae that Iack the cell-binding subunit SfaS but not with a strain lacking the major subunit SfaA. Both t-PA and plasminogen bound to purified S fimbriae in a lysine-dependent manner and purified S fimbriae accelerated t-PA-catalyzed plasminogen activation. The results indicate that E. coli S fimbriae form a complex with t-PA and plasminogen which enhances the rate of plasminogen activation and generates bacterium-bound plasmin. This may promote bacterial invasion and persistence in tissues and contribute to the systemic activation of fibrinolysis in septicaemia.
KW - Escherichia coli
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-71566
ER -
TY - JOUR
A1 - Engels, Bernd
T1 - Estimation of the influence of the configurations neglected within truncated MR-CI wavefunctions on molecular properties
N2 - Reliable prediction of the isotropic hyperfine coupling constant, a\(_{iso}\), is still a difficult task for ab initio calculations. Strong dependence on the method used for its calculation is found. Within a truncated multi-referencc ansatz a\(_{iso}\) is strongly affected by the size ofthe reference space and the nurober of terms in the truncated Cl expansion. In the present paperdifferent effects of the neglected Cl space are discussed. Modified B\(_K\) and A\(_K\) methods are used to estimate the contributions ofthe neglected configurations. lt can be shown that a combination of both methods is able to recover about 90-9 S% of the total error in a\(_{iso}\)· Furthermore, it was found that to obtain about 90% of the B\(_K\) correction only about I 0-20% ofthe configurations within H0 have to be corrected.
KW - Organische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58890
ER -
TY - JOUR
A1 - Wilhelm, Gernot
A1 - Zaccagnini, Carlo
T1 - Excavations at Tell Karrana 3 (1985 and 1986)
N2 - no Abstract available
KW - Tell Karrana
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85963
ER -
TY - JOUR
A1 - Schneider-Schaulies, Sibylle
A1 - Kreth, H. W.
A1 - Hofmann, G.
A1 - Billeter, M. A.
A1 - ter Meulen, V.
T1 - Expression of measles virus RNA in peripheral blood mononuclear cells of patients with measles, SSPE, and autoimmune diseases
N2 - No abstract available
KW - Virologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62297
ER -
TY - JOUR
A1 - Moll, Heidrun
A1 - Müller, Christoph
A1 - Gillitzer, Reinhard
A1 - Fuchs, Harald
A1 - Röllinghoff, Martin
A1 - Simon, Markus M.
A1 - Kramer, Michael D.
T1 - Expression of T-cell-associated serine proteinase-1 during murine Leishmania major infection correlates with susceptibility to disease
N2 - The expression of T-cell-associated serine proteinase 1 (MTSP-1) in vivo during Leishmania major infection was analyzed in genetically resistant C57BL/6 mice and in genetically susceptible BALB/c mice. Using a monoclonal antibody as well as an RNA probe specific for MTSP-1 to stain tissue sections, we found T cells expressing MTSP-1 in skin lesions and spleens of mice of both strains. In skin lesions, MTSP-1-positive T cells could be detected as early as 3 days after infection. Most importantly, the frequency of T cells expressing MTSP-1 was significantly higher in susceptible BALB/c mice than in resistant C57BL/6 mice. These findings suggest that MTSP-1 is associated with disease-promoting T cells and that it may be an effector molecule involved in the pathogenesis of cutaneous leishmaniasis.
KW - Biologie
KW - Immunologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61311
ER -
TY - JOUR
A1 - Fiala, Brigitte
A1 - Maschwitz, Ulrich
T1 - Extrafloral nectaries in the genus Macaranga (Euphorbiaceae) in Malaysia: comparative studies of their possible significance as predispositions for myrmecophytism.
N2 - So me species of the paleotropical tree genus Macaranga (Euphorbiaceae) live in elose association with ants. Thc genus comprises the full range of species from those not regularly inhabited by ants to obligate myrmecophytes. In Malaysia (peninsular and Borneo) 23 ofthe 52 species areknown to be ant-associated (44%). The simplest structural adaptation of plants to attract ants are extrafloral nectaries. We studied the distribution of extraflural nectaries in the genus Macaranga to assess the significance of this character as a possible predisposition for the evolution of obligate myrmecophytism. All species have marginal glands on the leaves. However, only the glands of nonmyrmecophytic species function as nectaries, whereas liquids secreted by these glands in myrmecophytic species did not contain sugar. Some non-myrmecophytic Macaranga and transitional Macaranga species in addition have extrafloral nectaries on the leaf blade near the petiole insertion. All obligatorily myrmecophytic Macaranga species, however, lack additional glands on the lamina. The non-myrmecophytic species are visited by a variety of different ant species, whereas myrmecophytic Macaranga are associated only with one specific ant-partner. Since these ants keep scale insects in the hollow sterns, reduction of nectary production in ant-inhabited Macaranga seems to be biologically significant. We interpret this as a means of (a) saving the assimilates and (b) stabilization of maintenance of the association's specificity. Competition with other ant species for food rewards is avoided and thereby danger ofweakening the protective function ofthe obligate antpartner for the plant is reduced. A comparison with other euphorb species living in the same habitats as Macaranga showed that in genera in which extrafloral nectaries are widespread, no myrmecophytes have evolved. Possession of extrafloral nectaries does not appear to be essential for the development of symbiotic ant-plant interactions. Other predispositions such as nesting space might have played a more important role.
KW - Macaranga
KW - extrafloral nectaries
KW - ant-plant interactions
KW - evolution of myrmecophytism
KW - Malaysia
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42863
ER -
TY - CHAP
A1 - Adam, D.
A1 - Schartl, A.
A1 - Andexinger, S.
A1 - Hölter, S.
A1 - Wilde, B.
A1 - Schartl, Manfred
T1 - Genetic factors in tumour formation: The melanoma-inducing gene of Xiphophorus
N2 - No abstract available.
KW - Humangenetik
KW - Tumor
KW - Entstehung
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86388
ER -
TY - JOUR
A1 - Schüssler, Ulrich
A1 - Talarico, F.
T1 - Granulite facies rocks from the Ross orogenic belt, Northern-Victoria-Land, Antarctica
N2 - no abstract available
KW - Geographie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-81889
ER -
TY - JOUR
A1 - Pauli, Paul
A1 - Hartl, Lydia
A1 - Marquardt, Christian
A1 - Stalmann, Henrica
A1 - Strian, Friedrich
T1 - Heartbeat and arrhythmia perception in diabetic autonomic neuropathy
N2 - A comparative study of diabetics with autonomic neuropathy (N = 13) as against nonneuropathic diabetics (N = 16) and healthy control persons (N = 20) was carried out with respect 10 heart rate both at rest and under stress, frequency of cardiac arrhythmias in a 24-h ECG and accuracy of heartbeat and arrhythmia perception. In the subjects with diabetic autonomic neuropathy, the spontaneaus variability and stress-induced reactivity of the heart rate as weil as the number of tachycardic episodes were reduced, whereas the frequency of ventricular extrasystoles was somewhat increased. Impaired heartbeat perception and a complete Ioss of perception of arrhythmias as a consequence of neuropathic deafferentation could be demonstrated. Cardiac perception disordersalso playavital roJe in other clinical problems, e.g. silent myocardial infarction and Iack of awareness of hypoglycaemia in diabetes mellitus.
KW - Psychologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73599
ER -
TY - JOUR
A1 - Sirén, Anna-Leena
A1 - Vonhof, S.
A1 - Feuerstein, G.
T1 - Hemodynamic defense response to thyrotropin-releasing
hormone injected into medial preoptic nucleus in rats
N2 - No abstract available
KW - Neurobiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63099
ER -
TY - JOUR
A1 - Sirén, Anna-Leena
A1 - Feuerstein, G.
T1 - Hypothalamic opioid µ-receptors regulate discrete hemodynamic functions in the conscious rat
N2 - The effect of the selective \(\mu\)-opioid agonist o-Ala\(^2\)-Me-Phe\(^4\)-Gly-ol'-enkephalin (DAGO), injected into the medial preoptic nucleus of hypothalamus, on cardiac output and regional blood flow was studied in the conscious rat and the effect of DAGO on renal sympathetic nerve activity and renal blood flow was studied in anesthetized rats. In conscious rats, injections of DAGO (1 or 10 nmol) into the preoptic nucleus increased the blood pressure in a dose-related manner. The maximum rises of mean arterial pressure and pulse pressure after the larger dose were +23 ± 5 mmHg (mean ±SEM, P < 0.01) and + 17 ± 3 mmHg(P < 0.01), respectively. A small dose (0.1 nmol) increased heart rate ( +47 ± 13 bpm, P < 0.05); thc 1 nmol dosc produced bradycardia (- 39 ± 11 bpm, P < 0.05), while the 10 nmol dose initially decreased heart rate ( -68 ± 15 bpm (P < 0.01) and then gradually increased heart rate to a maximum of + 74 ± 13 bpm, (P < 0.0 1). A long-lasting increase in cardiac output was also elicited by DAGO, with maximum changes after 1 and 10 nmol of + 14 ± 6% and +22 ± 7% (P < 0.01), respectively. B1ood flow in the hindquarters increascd after DAGO but the mesenteric and renal blood ftow decreased in a dose-related manner. Significant responscs in hindquarter and mesenteric blood fl.ow after DAGO were independent of systemic hemodynamic responses at the dose ofO.l nmol. The vascular resistance in the hindquarters significantly decreased after a small dose of DAGO while the larger doses dose-dependently increased mesenteric and renal vascular resistance. A crucial role of the sympathetic nervous system in the hemodynamic effects of DAGO was demonstrated: (1) by the profound activation of renal sympathetic nerve activity after injections of DAGO (I nmol/100 nl) into the preoptic nucleus, (2) by blockade of the pressor, tachycardic and regional hemodynamic effects of DAGO (I nmol) by the ganglion blocker ch1orisondamine (5 mg/kg i.v.). The results suggest that the pressor effect of DAGO in preoptic nucleus is due primarily to an increase in cardiac output. The differential changes in blood ftow in organs further suggest that the opioid \(\mu\)-receptors in the preoptic nucleus might be involved in the integration of peripheral blood ftow in the hypothalamus during affective behavior.
KW - Neurobiologie
KW - chlorisondamine
KW - blood pressure
KW - heart rate
KW - cardiac output
KW - regional blood ftow
KW - sympathetic nerve activity.
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63069
ER -
TY - JOUR
A1 - Dandekar, Thomas
A1 - Stripecke, Renata
A1 - Gray, Nicola K.
A1 - Goossen, Britta
A1 - Constable, Anne
A1 - Johansson, Hans E.
A1 - Hentze, Matthias W.
T1 - Identification of a novel iron-responsive element in murine and human erythroid \(\delta\)-aminolevulinic acid synthase mRNA
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29929
ER -
TY - JOUR
A1 - Tas, P.
A1 - Stopper, Helga
A1 - Koschel, K.
A1 - Schiffmann, D.
T1 - Influence of the carcinogenic oestrogen diethylstilboestrol on the intracellular calcium level in C6 rat glioma cells
N2 - The ~fthetic oes~rog~n diethylsti~boestrol (DES) causes a dose-dependent elevation of the cytoplasuuc Ca concentratton m C6 rat ghoma cells. This Ca2+ rise is caused neither by Ca2+ influx nor ~-r release from the ~a2 + stores of the endoplasmic reticulum. Therefore it seems likely that DES mob!hzes Ca2+ from a nutochondrial source. The DES-induced Ca2+ signal is remarkably similar to the one mduced by the. tumou~ promotor ~hapsigargin. As this compound causes leakage of calcium from the endoplasmt~ rettculum tt ~ms posstble that DES induces a similar leakage from mitochondrial Ca2+ stores. It remaans to be estabhshed whether the DES-mediated rise in intracellular calcium is causally related to the tumour-promoting properties of this compound
KW - Toxikologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63459
ER -
TY - JOUR
A1 - Lehrnbecher, T.
A1 - Merz, H.
A1 - Sebald, Walter
A1 - Poot, M.
T1 - Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4
N2 - Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells.
KW - Biochemie
KW - BrdU-Hoechst
KW - cell cycle
KW - flow cytometry
KW - interleukin 2
KW - interleukin 4
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62491
ER -
TY - JOUR
A1 - Preiser, J. C.
A1 - Schmartz, D.
A1 - Van der Linden, P.
A1 - Content, J.
A1 - Vanden Bussche, P.
A1 - Buurman, W.
A1 - Sebald, Werner
A1 - Dupont, E.
A1 - Pinsky, M. R.
A1 - Vincent, J. L.
T1 - Interleukin-6 administration has no acute hemodynamic or hematologic effect in the dog
N2 - To investigate the possible hemodynamic efl'ects of interleukin-6 (IL-6), a single dose of 15 mcg/kg of recombinant IL-6 isolated from Escherichia coli was injected intravenously in six pentobarbital-anesthetized dogs. After 30 min, saline infusion was performed to maintain the - pulmonary artery balloon-occluded pressure at baseline Ievel. The animals were observed for up to 5 hours. No other hemodynamic alteration was observed than a gradual decline in cardiac output attributed to anesthesia. Hematologic variables, blood glucose, and total serum proteins were also constant. IL-6 levels were markedly elevated in the blood, bot no tumor necrosis factor activity was detected. Thus a primary role for IL-6 in the early cardiovascular alterations associated with septic shock seems unlikely.
KW - Biochemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62511
ER -
TY - JOUR
A1 - Hacker, Jörg
A1 - Ott, M.
A1 - Ludwig, B.
A1 - Rdest, U.
T1 - Intracellular survival and expression of virulence determinants of Legionella pneumophila
N2 - Legionella pneumophila, the causative agent of Legionnaires' disease is able to live and multiply within macrophages as weil as within protozoan organisms. Legionella strains inhibit phagosome-lysosome fusion and phagosome acidification. By using two different cell culture systems, one derived from human macrophages and the other from human.embryo lung fibro:blastic cells, it is demonstrated that Legionella strains lose their virulence following cultivation in the laboratory. In order to study the mechanisms involved in intracellular survival of Legionella a genomic library of strain Legionella pneumophila Philadelphia I was established in Escherichia coli K-12. By cosmid cloning technique we were able to clone five putative virulence factors, two of which exhibit hemolytic activities and three of which represent membrane-associated proteins of 19, 26 and 60 kilodalton. One of the hemolytic proteins, termed legiolysin, represents a new toxin which specifically lyses human erythrocytes. The other hemolysin exhibits proteolytic properties in addition and is cytolytic for Vero and CHO cells. Further sturlies will be necessary to determine the exact role of the cloned proteins in the pathogenesis of Legionella. Zusammenfassung: Intrazelluläres Überleben
N2 - Intrazelluläres Überleben und Expression der Virulenzdeterminanten vonLegionella pneumophila. L. pneumophila, der Erreger der Legionärskrankheit, hat die Fähigkeit, sowohl in Makrophagen als auch in Protozoen zu leben und sich dort zu vermehret;t. Legionellen inhibieren die Fusion von Phagosom und Lysosom und hemmen die Ansäuerung des Phagosoms. Mit Hilfe von zwei unterschiedlichen Zellkultur-Systemen konnte gezeigt werden, daß Legionella-Stämme ihre Virulenz nach Laborpassage verlieren. Um die Mechanismen zu studieren, die für das intrazelluläre Überleben von Legionellen verantwortlich sind, haben wir eine Genbank des Legionella pneumophila-Stammes Philadelphia I in Escherichia coli K-12angelegt. Mit Hilfe der Cosmid-Klonierungstechnik war es möglich, fünf putative Virulenzfaktoren zu klonieren. Zwei von diesen Faktoren haben hämolytische Eigenschaften und drei sind Membran-assoziierte Proteine mit Molekulargewichten von 19, 26 und 60 kilodalton. Eines der hämolytischen Proteine, das Legiolysin, lysiert spezifisch humane Erythrozyten. Das zweite Hämolysin zeigt zusätzlich proteolytische Eigenschaften und schädigt sowohl Vero- als auch CHO-Zellen. Weitere Studien sind notwendig, um die Rolle der klonierten Proteine in der Pathogenese von Legionella exakt zu bestimmen.
KW - Infektionsbiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59681
ER -
TY - CHAP
A1 - Ellgring, Johann Heinrich
T1 - Introduction. The use of Video for behavior description and intervention
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42019
ER -
TY - JOUR
A1 - Hacker, Jörg
A1 - Rdest, Ursula
A1 - Wintermeyer, E.
A1 - Ludwig, B.
T1 - Legiolysin, a New Hemolysin from L. pneumophila
N2 - Legionella pneumophila generares exotoxins, cytolysins, proteases oc hemolysins that darnage host cells llke erythrocytes or rissue cu lrure cells. The gene for a new L. pneumophila hemolysin withour a proteolytic activiry was idemified, cloned in E. coli and sequenced. The gene producr was analysed by SDS-Polyacrylamide-gel-electrophoresis.
N2 - Legionella pneum.ophila bildet Exoroxine, Zytolysine, Proteasen oder Hämolysine, die Wirtszellen wie Erythrozyten oder Animalzellen schädigen. Das Gen für ein neues L. pneumophila Hämolysin ohne proteolytische Aktivität wurde identifiziert, in E. coli kloniert und sequenziert. Das Genprodukt wurde durch SDS-Gelelcktropborese analysiert.
KW - Hämolysin
KW - Legionella pneumophila
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73070
ER -
TY - JOUR
A1 - Thiry, Marc
A1 - Scheer, Ulrich
A1 - Goessens, Guy
T1 - Localization of nucleolar chromatin by immunocytochemistry and in situ hybridization at the electron microscopic level
N2 - Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well as the definition of nucleolar structures in which enzymes of the rDNA transcription machinery reside have been investigated in mammalian cells by various immunogold labelling approaches at the ultrastructural level. The precise intranucleolar location of rRNA genes has been further specified by electron microscopic in situ hybridization with a non-autoradiographic procedure. Our results indicate that the fibrillar centers are the sole nucleolar structures where rDNA, core histones, RNA polymerase I and DNA to po isomerase I are located together. Taking into account the potential value and limitations of immunoelectron microscopic techniques, we propose that transcription of the rRNA genes takes place within the confines of the fibrillar centers, probably close to the boundary regions to the surrounding dense fibrillar component.
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39289
ER -
TY - JOUR
A1 - Krzymanski, M.
A1 - Waaga, A. M.
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, Wolfgang
T1 - Long-standing rat kidney graft survival by a combination of organ perfusion with MHC class II monoclonal antibody and immunosuppression with reduced doses of 15-deoxyspergualin.
N2 - No abstract available
KW - Niere
KW - Ratte
KW - MHC Klasse II
KW - kidney
KW - rat
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64442
ER -
TY - JOUR
A1 - Carr, Martha
A1 - Schneider, Wolfgang
T1 - Long-term maintenance of organizational strategies in kindergarten children
N2 - The goal of the present study was to determine whether 4- and 5-year-old kindergarten children could be trained to maintain an organizational strategy over 2- and 8 week periods through an elaborate training program. A second goal was to assess the effects of the training program on strategy awareness. Twenty-eight kindergarten children were pretested on two sort-recall tasks and their awareness of the use of the clustering strategy was assessed through a protocol type procedure. Half the children received seven half-hour sessions of individual training in the clustering strategy and half the children participated in a control group. Both groups were post-tested on two sort-recall tasks 2 weeks following training and again 8 weeks following training. Strategy awareness, as measured by verbal protocol, was assessed at both post-test points. The elaborate strategy training program was successful in inducing short- and long-term strategy maintenance of the clustering strategy. Trained children’s clustering during sorting and clustering during recall was consistently related to the amount of items correctly recalled. No differences in strategy awareness were found. These findings demonstrate that the elaborate training procedure used in this study can be a very effective memory technique for young kindergarten children.
KW - Psychologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62157
ER -
TY - JOUR
A1 - Näslund, Jan Carol
A1 - Schneider, Wolfgang
T1 - Longitudinal effects of verbal ability, memory capacity, and phonological awareness on reading performance
N2 - This study addresses the longitudinal relationship among verbal ability, memory capacity, phonological awareness, and reading performance. Data from 92 German children were used to explore the exact relation among these variables. Indicators of verbal ability, memory capacity, and phonological awareness were assessed in kindergarten and again after the first grade. The interrelationships among these factors, and the subsequent influence they have on decoding speed and reading comprehension during the second grade were examined via structural equation modefing procedures. Overall, the results of the longitudinal analyses show that the relationship of memory capacity and phonological awareness remains stable over time, and that memory capacity predicts performance on phonological awareness tasks in both kindergarten and second grade. Phonological awareness proved to be a significant predictor of decoding speed, which in turn considerably influenced reading comprehension.
KW - Lesefähigkeit
KW - Sprachfertigkeit
KW - Gedächtnisleistung
KW - Phonologische Bewusstheit
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86606
ER -
TY - JOUR
A1 - Solbach, Werner
A1 - Moll, Heidrun
A1 - Röllinghoff, Martin
T1 - Lymphocytes play the music but the macrophage calls the tune
N2 - No abstract available
KW - Immunologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45889
ER -
TY - JOUR
A1 - Schlupp, I.
A1 - Parzefall, J.
A1 - Schartl, Manfred
T1 - Male mate choice in mixed bisexual/-unisexual breeding complexes of Poecilia (Teleostei: Poeciliidae)
N2 - The livebearing all-female fish Poecilia formosa reproduces by gynogenesis, a modified form of parthenogenesis. P. formosa forms at least two breeding complexes: in its northern range it exists sympatrically with Poecilia latipinna and in its southern range with Poecilia mexicana. Differences between these complexes and their possible origin are discussed. Embryogenesis is triggered by sperm of males of these closely related sympatric species. Because inheritance is stricdy maternal, from the male point of view energy and time invested are totally lost. In this study we wanted to elucidate whether males are able to distinguish between conspecific and parasitic females. It could be shown that males are able to distinguish females optically, but that this ability was obscured as soon as chemical and/or tactile contact was possible. Furthermore, we found that females in an attractive phase of their sexual cycle are always preferred, regardless of species. This is possibly the mechanism by which parasitic females obtain the matings they need to reproduce.
KW - Poecilia (Teleostei: Poeciliidae)
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80309
ER -
TY - JOUR
A1 - Schartl, Manfred
A1 - Erbelding-Denk, Claudia
A1 - Nanda, Indrajit
A1 - Schmid, Michael
A1 - Schröder, Johannes Horst
A1 - Epplen, Jörg T.
T1 - Mating success of subordinate males in a poeciliid fish species, Limia perugiae
N2 - No abstract available.
KW - Lebendgebärende Zahnkarpfen
KW - Perugia-Kärpfling
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86349
ER -
TY - JOUR
A1 - Lohse, Martin J.
A1 - Klotz, Karl-Norbert
A1 - Schwabe, Ulrich
T1 - Mechanism of A2 adenosine receptor activation. I. Blockade of A2 adenosine receptors by photoaffinity labeling
N2 - It has previously been shown that covalent incorporation of the photoreactive adenosine derivative (R)-2-azido-N6-p-hydroxyphenytisopropyladenosine [(R)-AHPIA] into the A, adenosine receptor of intact fat cells leads to a persistent activation of this receptor, resulting in a reduction of celular cAMP Ieveis [Mol. Pharmacol. 30:403-409 (1986)]. In contrast, covalent incorporation of (R)-AHPIA into human platelet membranes, which contain only stimulatory A2 adenosine receptors, reduces adenytate cyclase Stimulation via these receptors. This effect of (R)-AHPIA is specific for the A2 receptor and can be prevented by the adenosine receptor antagonist theophylline. Binding studies in-dicate that up to 90% of A2 receptors can be blocked by photoincorporation of (R)-AHPIA. However, the remaining 10-20% of A2 receptors are sufficient to mediate an adenylate cyclase Stimulation of up to SOOk of the control value. Similarly, the activation via these 10-20% of receptors occurs with a halflife that is only 2 times Ionger than that in control membranes. This indicates the presence of a receptor reserve, with respect to both the extent and the rate of adenytate cyclase Stimulation. These observations require a modification of the models of receptor-adenytate cyclase coupling, which is described in the accompanying paper [Mol. Pharmacol. 39:524-530 (1991)].
KW - Adenosinrezeptor
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86073
ER -
TY - JOUR
A1 - Bentley, T. W.
A1 - Christl, Manfred
A1 - Norman, S. J.
T1 - Methanesulfonate/p-Nitrobenzoate and p-Toluenesulfonate/p-Nitrobenzoate Rate Ratios. Solvolyses of 1-Adamantyl and Benzhydryl Substrates
N2 - No abstract available
KW - Organische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58599
ER -
TY - JOUR
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, Wolfgang
T1 - Modulation of pancreatic islet allo immunogenicity and immunobiological in vitro and in vivo consequences
N2 - No abstract available.
KW - Immunobiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78261
ER -
TY - CHAP
A1 - Hommers, Wilfried
A1 - Anderson, Norman H.
T1 - Moral algebra of harm and recompense
N2 - No abstract available
KW - Informationsverarbeitung / Kognition
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44046
ER -
TY - CHAP
A1 - Winoto-Morbach, S.
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, W.
T1 - New Developments in Biodegradable Microspheres For Magnetic Separation Techniques
N2 - No abstract available
KW - Immunbiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45712
ER -
TY - JOUR
A1 - Van Die, I.
A1 - Kramer, C.
A1 - Hacker, Jörg
A1 - Bergmans, H.
A1 - Jongen, W.
A1 - Hoekstra, W.
T1 - Nucleotide sequence of the genes coding for minor fimbrial subunits of the F1C fimbriae of Escherichia coli
N2 - F 1 C fimbriae allow uropathogenic Escherichia coli to adhere to specific epithelial surfaces. This adhesive property is probably due to the presence of minor fimbrial components in F1C fimbriae. The foe gene cluster encoding F1C fimbriae has been cloned, as described previously. Here we present the nucleotide sequence (2081 bp) coding for the F 1 C minor fimbria I subunits. The structural genes code for polypeptides of 175 (FocF), 166 (FocG), and 300 (FocH) amino acids. The deduced amino acids of the F 1 C minor subunits were compared with the reported sequences of the minor subunits of other types of fimbriae. The data show that the Foc minor subunits are highly homologous to the corresponding Sfa proteins, whereas homology to the minor subunits of type 1 and P fimbriae is much lower.
KW - Pilus
KW - Escherichia coli
KW - Adherence
KW - Urinary tract
KW - Foc protein
KW - Minor subunits
KW - Sequencing
KW - Homology
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40353
ER -
TY - JOUR
A1 - Dandekar, Thomas
T1 - Olbers' Paradox (peer-reviewed scientific correspondence)
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31672
ER -
TY - CHAP
A1 - Epplen, J. T.
A1 - Ammer, H.
A1 - Epplen, C.
A1 - Kammerbauer, C.
A1 - Mitreiter, R.
A1 - Roewer, L.
A1 - Schwaiger, W.
A1 - Steimle, V.
A1 - Zischler, H.
A1 - Albert, E.
A1 - Andreas, A.
A1 - Beyermann, B.
A1 - Meyer, W.
A1 - Buitkamp, J.
A1 - Nanda, I.
A1 - Nürnberg, P.
A1 - Pena, S. D. J.
A1 - Pöche, H.
A1 - Sprecher, W.
A1 - Schartl, Manfred
A1 - Weising, K.
A1 - Yassouridis, A.
T1 - Oligonucleotide fingerprinting using simple repeat motifs: a convenient, ubiquitously applicable method to detect hypervariability for multiple purposes
N2 - A panel of simple repetitive oligonucleotide probes has been designed and tested for multilocus DNA fingerprinting in some 200 fungal, plant and animal species as well as man. To date at least one of the probes has been found to be informative in each species. The human genome, however, has been the major target of many fingerprintins studies. Using the probe (CAC)5 or (GTG)5, individualization of all humans is possible except for monozygotic twins. Paternity analyses are now perfonned on a routine basis by the use of multilocus fingerprints, inctuding also cases of deficiency, i.e. where one of the parents is not available for analysis. In forensie science stain analysis is feasible in all tissue remains containing nuc)eated cells. Depending on the degree of DNA degradation a variety of oligonucleotides are informative, and they have been proven useful in actual case work. Advantages in comparison to other methods including enzymatic DNA amplification techniques (PCR) are evident. Fingerprint patterns of tumors may be changed due to the gain or loss of chromosomes and/or intrachromosomal deletion and amplification events. Locus-specific probes were isolated from the human (CAC)5/( GTG)5 fingerprint with a varying degree of informativeness (monomorphic versus truly hypervariable markers). The feasibility of three different approaches. for the isolation of hypervariable mono-locus probes was evaluated. Finally, one particular mixed simple (gt)n(ga)m repeat locus in the second intron of the HLA-DRB genes has been scrutinized to allow comparison of the extent of exon-encoded (protein-) polymorphisms versus intronie bypervariability of simple repeats: adjacent to a single gene sequence (e.g. HLA-DRB1*0401) many different length alleles were found. Group-specific structures of basic repeats were identified within the evolutionarily related DRB alleles. As a further application it is suggested here that due to the ubiquitous interspersion of their targets, short probes for simple repeat sequences are especially useful tools for ordering genomic cosmid, yeast artificial chromosome and phage banks.
KW - DNS
KW - Fingerprint-Verfahren
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86371
ER -
TY - JOUR
A1 - Schartl, Manfred
A1 - Schlupp, Ingo
A1 - Schartl, Angelika
A1 - Meyer, Manfred K.
A1 - Nanda, Indrajit
A1 - Schmid, Michael
A1 - Epplen, Jörg T.
A1 - Parzefall, Jakob
T1 - On the stability of dispensable constituents of the eukaryotic genome: Stability of coding sequences versus truly hypervariable sequences in a clonal vertebrate, the amazon molly, Poecilia formosa
N2 - In dooal unisexual vertebrales, the genes specifying the males become dispensable. To study tbe rate of such geoes the gynogeoetic all-female fisb Poecilillfonnolll was treated with androgens. Phenotypic males were obtained that exbibited the complete set of male cbaracteristics of dosely related gooocboristic species, induding body proportions, pigmentation, the extremely complex insemination apparatus of poecilüd fish, sexual bebavior, and spermatogeoesls. Tbe apparent stabllity of such genic structures, induding those involved in androgen regulation, is contrasted by high instability of noncoding sequeaces. Frequent mutations, thelr donal transmission, and at least two truly hypervariable Iod leading to individual difl'ereaces between these othenrise donal organisms were detected by DNA fingerprinting. These observations substantiate the concept that also in "ameiotic" vertebrates certain compartments of the genome are more prooe to mutatiooal alterations than others.
KW - Physiologische Chemie
KW - DNA fingerprinting
KW - androgen-induced masculinization
KW - gynogeaesls
KW - simple repeat sequences
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61731
ER -
TY - JOUR
A1 - Jaiswal, Neelam
A1 - Lambrecht, Günter
A1 - Mutschler, Ernst
A1 - Tacke, Reinhold
A1 - Malik, Kafait U.
T1 - Pharmacological characterization of the vascular muscarinic receptors mediating relaxation and contraction in rabbit aorta
JF - Journal of Pharmacology and Experimental Therapeutics
N2 - Studies were performed in the rabbit aortic rings, precontracted with norepinephrine, to determine the subtype(s) of muscarinic receptors involved in endothelium-dependent relaxation and contraction in the absence of endothelium elicited by cholinergic stimuli. Acetylcholine (ACh) and arecaidine propargyl ester (APE), a M2 and M3 agonist, produced a dose-dependent relaxation and contraction in endothelium-intact and endothelium-denuded rabbit aortic rings, respectively. Both of these responses were blocked by the muscarinic receptor antagonist atropine. M1 selective agonist McN-A-343 [4-[N-(3-chlorophenyl)carbamoyloxy]-2-butinyltrimethylammonium+ ++ chloride] did not produce any effect on the tone of precontracted aortic rings. ACh- and APE-induced relaxation in aortic rings with intact endothelium was selectively blocked by M3 receptor antagonists hexahydrosila-difenidol and p-fluoro-hexahydro-sila-difenidol (pA2 of 7.84 and 7.18) but not by M1 antagonist pirenzepine or M2 receptor antagonists AF-DX 116 [11-(2-[(diethylamino)methyl]- 1-piperidinyl]acetyl)-5, 11-dihydro-6H-pyrido-[2,3-b][1,4]-benzo-diazepin-6-one] and methoctramine. ACh- and APE-induced contraction was inhibited by M2 receptor antagonists AF-DX 116 and methoctramine (pA2 of 7.11 and 6.71) but not by pirenzepine, hexahydro-sila-difenidol or p-fluoro-hexahydro-sila-difenidol. ACh- and APE-induced relaxation or contraction were not altered by nicotinic receptor antagonist hexamethonium or cyclooxygenase inhibitor indomethacin. These data suggest that relaxation elicited by cholinergic stimulin in endothelium-intact aortic rings is mediated via release of endothelium-derived relaxing factor consequent to activation of M3 receptors located on endothelial cells, whereas the contraction in aortic rings denuded of their endothelium is mediated via stimulation of M2 receptors located on smooth muscle cells.
KW - (4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethylammonium chloride/pharmacology
KW - acetylcholine
KW - animals
KW - antihypertensive agents / pharmacology
KW - aorta, abdominal / drug effects
KW - aorta, abdominal / physiology
KW - aorta, abdominal / ultrastructure
KW - arecoline/analogs & derivatives
KW - arecoline
KW - atropine
KW - diamines
KW - endothelium, vascular / drug effects
KW - endothelium, vascular / physiology
KW - hexamethonium
KW - hexamethonium compounds
KW - indomethacin
KW - male
KW - muscarinic antagonists
KW - muscle contraction
KW - muscle relaxation
KW - norepinephrine
KW - parasympatholytics
KW - piperidines
KW - pirenzepine
KW - rabbits
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128358
VL - 258
IS - 3
ER -
TY - JOUR
A1 - Ott, M.
A1 - Bender, L.
A1 - Chirinos, E.
A1 - Ehret, W.
A1 - Hacker, Jörg
T1 - Phenotype versus genotype of the 19 kd peptido-glycan associated protein of Legionella (PplA) among Legionellae and other gram-negative bacteria
N2 - The protein PpiA (19 kD) cloned from a genomic library of Legionella pneumophila, Philadelphia 1, represents a peptido-glycan associated outer membrane protein in recombinant E. coli K-12 and L. pneumophila. lt exhibits distinct sequence homology to Iipoproteins of Haemophilus influenzae and E. coli. A ppiA specific DNA probe generated by PCR was used in Southern hybridizations of chromosomal DNA of Legionella strains and other Gram-negative pathogens. Under conditions of high stringency, hybridization could only be observed in L. pneumophila isolates, but alt other Legionella strains tested displayed hybridization under lower stringency. No signals appeared after hybridization of chromosomal DNA from a variety of other bacteria. Using anti-PpiA monospecific polyclonal antibodies in Western blots, it was demonstrated that PpiA related proteins of nearly the same size are found in all L. pneumophila isolates and in a variety of, but not alt, the Legionella species analysed here.
KW - Infektionsbiologie
KW - Legionellae
KW - peptido-glycan associated protein
KW - ppl
KW - Southern hybridization
KW - stringency
KW - polymerase chain reaction (PCR)
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59768
ER -
TY - JOUR
A1 - Schülein, Ralf
A1 - Kreft, Jürgen
A1 - Gonski, Sigrid
A1 - Goebel, Werner
T1 - Preprosubtilisin Carlsberg processing and secretion is blocked after deletion of amino acids 97-101 in the mature part of the enzyme
N2 - During an investigation into the substrate specificity and processing of subtilisin Carlsberg from Bacillus licheniformis, two major independent findings were made: (i) as has been shown previously, a stretch of five amino acids (residues 97-101 of the mature enzyme) that loops out into the binding cleft is involved in substrate binding by subtilisin Carlsberg. In order to see whether this loop element also determines substrate specificity, the coding region for these five amino acids was deleted from the cloned gene for subtilisin Carlsberg by site-directed mutagenesis. Unexpectedly the resulting mutant preproenzyme (P42c, Mr=42 kDa) was not processed to the mature form (Mr = 30 kDa) and was not released into the medium by a proteasedeficient B. subtilis host strain; rather, it accumulated in the cell membrane. This result demonstrates that the integrity of this loop element, which is very distant from the processing cleavage sites in the preproenzyme, is required for secretion of subtilisin Carlsberg. (ii) In culture supernatants from B. subtilis harbouring the cloned wild-type subtilisin Carlsberg gene the transient appearance (at 0-3 h after onset of stationary phase) of a processing intermediate (P38c, Mr = 38 kDa) oftbis protease could be demonstrated. P38c very probably represents a genuine proform of subtilisin Carlsberg.
KW - Biologie
KW - Bacillus
KW - Proenzyme
KW - Subtilisin maturation
KW - Site-directed mutagenesis
KW - Subtilisin Carlsberg
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60577
ER -
TY - JOUR
A1 - Bothe, Katrin
A1 - Aguzzi, Adriano
A1 - Lassmann, Hans
A1 - Rethwilm, Axel
A1 - Horak, Ivan
T1 - Progressive encephalopathy and myopathy in transgenic mice expressing human foamy virus genes
N2 - Transgenie mice carrying the bel region of human foamy retrovirus (HFV) under transcriptional control of its own long terminal repeat expressed tbe transgene in their centrat nervous systems and in smootb and striated muscle tissues. The animals developed a progressive degenerative disease of tbe centrat nervous system and of the striated muscle. Because expression of tbe transgene was dosely correlated witb the appearance of structural damage and inflammatory reactions were scanty, the disease is likely to be caused directly by tbe HFV proteins. These unexpected findings call for a reevaluation of tbe patbogenic potential of HFV in humans.
KW - Virologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61453
ER -
TY - JOUR
A1 - Kaupp, Martin
A1 - Schleyer, P. v. R.
A1 - Stoll, H.
A1 - Preuss, H.
T1 - Pseudopotential Approaches to Ca, Sr and Ba Hybrides. Why are some Alkaline Earth MX\(_2\) Compounds Bent?
N2 - Quasirelativistic and nonrelativistic lo-valence-electronp seudopotentialsf or Ca, Sr, and Ba are presented. Results of calculations with 6s6p5d basis sets for MH, MH\(^+\) , and MH\(_2\), are compared with all-electron and 2-valence-electron pseudopotential calculations with and , without core-polarization potentials. The lo-valence-electron pseudopotential approach agrees well with all-electron calculations. It circumvents problems for the 2-valence-electron pseudopotentials arising from an incomplete separation of valence and subvalence shells in polar molecular systems due to strongly contracted occupied (n - 1 )-d orbitals. All higherlevel calculations show SrH\(_2\) and BaII\(_2\), to be bent with angles of - 140° and 120°, respectively, while CaH\(_2\) is linear with a flat potential-energy surface for the bending motion. The use of a core-polarization potential together with the 2-valence-electronp seudopotentiala pproach allows an investigation of the relative importance of core-polarization vs direct d-orbital bonding participation as reasons for the bent structures. The calculations strongly suggest that both contribute to the bending in SrH\(_2\) and BaII\(_2\). Even at the Hartree-Fock level of theory lovalence- electronp seudopotentialc alculations given reasonablea nglesw hen the potentialenergy surface is not exceedingly flat, and only moderately contracted basis sets including both compact d functions and diffuse p functions are used. The effect of core-valence correlation and the importance off functions also are discussed.
KW - Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31646
ER -
TY - JOUR
A1 - Ott, M.
A1 - Bender, L.
A1 - Marre, R.
A1 - Hacker, Jörg
T1 - Pulsed field electrophoresis of genomic restriction fragments for the detection of nosocomial Legionella pneumophila in hospital water supplies
N2 - Ten Legionella pneumophUa strains isolated from dift'erent sources were analyzed according to their restriction fragment patterils obtained by cle~vage of gen.omic DNA With Notl and Sftl and separation by pulsed field electrophoresis. Three L. pneumophila isolate~ from a nosocomial outbreak in Lü~k (Germany) and three other L. prreumophilll stralns independently isolated from a water tap located in the care unit where tbe patients were bospitalized 'xhibited identical restricti9n fragment profiles. Therefore, we concluded that these environment81 spee~ens were the source of the Legionnatres dlsease. Anotber two isolates from patients and two strains from the environment, all unrelated to the outJlreak described, sbowed different cleavage patterns.
KW - Infektionsbiologie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59672
ER -
TY - JOUR
A1 - Malitschek, B.
A1 - Schartl, Manfred
T1 - Rapid identification of recombinant baculoviruses using PCR
N2 - no abstract available
KW - PCR
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80328
ER -
TY - JOUR
A1 - Stöckli, K. A.
A1 - Lililien, L. E.
A1 - Näher- Noé, M.
A1 - Breitfeld, G.
A1 - Hughes, Richard A.
A1 - Raff, M. C.
A1 - Thoenen, Hans
A1 - Sendtner, Michael
T1 - Regional distribution, developmental changes, and cellular localization of CNTF-mRNA and protein in the rat brain
N2 - Ciliary neurotrophic factor (CNTF) is a potent survival molecule for a variety of embryonic neurons in culture. The developmental expression of CNTF occurs clearly after the time period of the physiological cell death of CNTF-responsive neurons. This, together with the sites of expression, excludes CNTF as a target-derived neuronal survival factor, at least in rodents. However, CNTF also participates in the induction of type 2 astrocyte differentiation in vitro. Here we demonstrate that the time course of the expression of CNTF-mRNA and protein in the rat optic nerve (as evaluated by quantitative Northern blot analysis and biological activity, respectively) is compatible with such a glial differentiation function of CNTF in vivo. We also show that the type 2 astrocyte-inducing- activity previously demonstrated in optic nerve extract can be precipitated by an antiserum against CNTF. Immunohistochemical analysis of astrocytes in vitro and in vivo demonstrates that the expression of CNTF is confined to a subpopulation of type 1 astrocytes. The olfactory bulb of adult rats has comparably high levels of CNTF to the optic nerve, and here again, CNTF-immunoreactivity is localized in a subpopulation of astrocytes. However, the postnatal expression of CNTF in the olfactory bulb occurs later than in the optic nerve. In other brain regions both CNTF-mRNA and protein levels are much lower.
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31172
ER -
TY - JOUR
A1 - Tony, H. P.
A1 - Lehrnbecher, T.
A1 - Merz, H.
A1 - Sebald, Werner
A1 - Wilhelm, M.
T1 - Regulation of IL-4 responsiveness in lymphoma B cells
N2 - The responsiveness to IL-4 with and without costimulation with anti-IgM antibodies or phorbolester was studied in 35 cases of low grade non-Hodgkin Iymphoma by analyzing enhancement of CD23 and HLA dass li expression. The predominant phenotype responds directly to IL-4. Separate differentiation states can be distinguished according to coordinate or differential upregulation of CD23 and HLA dass II molecules by IL-4 alone, and differences in responsiveness to anti-IgM antibodies. A particular subgroup of B-lymphoma cells defines a separate stage of B-eeil differentiation. They fail to express high affinity binding sites for IL-4 and accordingly do not respond to IL-4- mediated signals. Cross-linking membrane lgM receptors or direct activation of protein kinase C via phorbolester induces IL-4 receptor expression and subsequent IL-4 reactivity.
KW - Biochemie
KW - B lymphocytes
KW - CD23
KW - CLL
KW - HLA class ll
KW - IL-4
KW - IL-4-receptor
KW - membrane immunoglobulin
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62520
ER -
TY - JOUR
A1 - Vonhof, S.
A1 - Sirén, Anna-Leena
T1 - Reversal of µ-opioid-mediated respiratory depression by α2-adrenoceptor antagonism
N2 - The present study was performed in order to evaluate the effects of the selective 02- adrenoceptor antagonist 6-chloro-2,3,4,5-tetrahydro-3-methyl-1H-3-benzazepine (SK&F 86466) on dermorphin-induced analgesia, respiratory depression and inhibition of locomotor activity in the conscious rat. Intracerebroventricular (icv) administration of dermorphin (3 nmol/rat) decreased respiration rate and relative ventilatory minute volume maximally by 38 % and 50 % of baseline respectively. SK&F 86466 dose-dependently reversed the dermorphin-induced depression of ventilatory parameters, while SK&F 86466 exerted no effect on dermorphin-induced analgesia or depression of locomotor activity due to catalepsia. It appears, therefore, that a 2-adrenoceptors selectively interact with Jl2-opioid-receptor mediated effects, such as respiratory depression, but are not involved in the modulation of Jl,-opioid-related effects, such as supraspinal analgesia and depression of locomotor activity.
KW - Biowissenschaften
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47454
ER -
TY - JOUR
A1 - Feifel, R.
A1 - Rodrigues de Miranda, J. F.
A1 - Strohmann, C.
A1 - Tacke, Reinhold
A1 - Aasen, A. J.
A1 - Mutschler, E.
A1 - Lambrecht, G.
T1 - Selective labelling of muscarinic M\(_1\) receptors in calf superior cervical ganglia by [\(^3\)H](\(\pm\))-telenzepine
N2 - A method was developed to detennine the affinities of antimuscarinic drugs at M\(_1\) receptors. [\(^3\)H](±)-Telenzepine served as radioligand in crude preparations of calf superior cervical ganglia and showed high affinity for a single receptor population. consisting of M1 receptors (K\(_D\) = 1.12 nM). Kinetic experiments showed monophasic association (k\(_1\) =0.017 min\(^{-1}\) nM\(^{-1}\) ) and dissociation (k\(_1\) = 0.017 min\(^{-1}\) ) kinetics, the half-life of dissociation being 41 min at 37°C. The kinetie K\(_D\) value amounted to 1.00 nM. M\(_1\) affinities for pirenzepine, methoctramine. hexahydro-sila-difenidol and p-fluoro-hexahydro-sila-difenidol detennined in competition experiments were similar to those found in functional studies with MI receptors in rabbit isolated vas deferens. The binding assay was used to deterriline the affinities of the (R) and (S) enantiomers of tertiary (trihexyphenidyl, hexahydro-difenidol. hexbutinol, p-fluoro-hexbutinol) and quatemary musearlnie antagonists (trihexyphenidyl methiodide. hexbutinol methiodide). Comparison of results obtained with the rabbit vas deferens suggested that the ionic environment may influence the affinities.
KW - Anorganische Chemie
KW - Muscarinic M1 receptors
KW - Superior cervical ganglia (calf)
KW - Hexahydro-difenidol analogues
KW - Trihexyphenidyl
KW - Hexbutinol
KW - Stereoselectivity
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64082
ER -
TY - JOUR
A1 - Heinsen, Helmut
A1 - Heinsen, Y. L.
T1 - Serial thick, frozen, gallocyanin stained sections of human central nervous system
N2 - A rapid method for macroscopic and microscopic investigation of human CNS is proposed. After fonnalin fixation, gelatin or agarose embedding, and cryoprotective treatment, frozen human spinal cords, brainstems, or hemispheres can be serially cut into 0.7 mm thick slices. Stained with gallocyanin-chromalum, these slices facilitate cytoarchitectonic, neuropathologic, and quantitative examination. Regions of interest from parallel fonnalin-stored unstained slices can be embedded into paraffin and stained by any irnrnunocytologic and histologic stain compatible with fonnalin fixation and paraffin embedding.
KW - CNS
KW - comparative anatomy
KW - cytoarchitectonics
KW - neuroimaging
KW - neuropathology
KW - Nissl stain
KW - quantitative anatomy
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45741
ER -
TY - JOUR
A1 - Kruse, N.
A1 - Lehrnbecher, T.
A1 - Sebald, Walter
T1 - Site-directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human interleukin-4
N2 - Mutant proteins (muteins) of human lnterleukin-4 (llA) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. co/1, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted. in a nearly co•mplete loss · of biological actiyity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of · the single tryptophane had smaller etTects.
KW - Biochemie
KW - Interleukin 4 (human)
KW - Recombinant
KW - ln vitro mutagenesis
KW - Structure-function
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62505
ER -
TY - JOUR
A1 - Dabauvalle, Marie-Christine
A1 - Loos, Karin
A1 - Merkert, Hilde
A1 - Scheer, Ulrich
T1 - Spontaneous assembly of pore complex-containing membranes ("Annulate lamellae") in Xenopus egg extract in the absence of chromatin
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32797
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Brakmann, S.
A1 - Wuttke, F.
A1 - Fooladi, J.
A1 - Syldatk, C.
A1 - Schomburg, D.
T1 - Stereoselective microbial reduction of racemic acetyl(t-butyl)methylphenylsilane by Trigonopsis variabilis (DSM 70714) and Corynebacterium dioxydans (ATCC 21766)
N2 - (SiR,CR)- and (SiS,CR)-t-butyl(l-hydroxyethyl)methylphenylsilane [(SiR,CR)-2 and (SiS,CR)-3] have been prepared by (R)-selective microbial rcduction of racemic acetyl(t-butyl)methylphenylsilane (rac-1) using resting free cells of the yeast Trigonopsis variabilis (DSM 70714) or the bacterium Corynebacterium dioxydans (ATCC 21766). The biotransfonnations were carried out on a 10 g scale. Afterseparation by column chromatography on silica gel, the optically active diastereomers (SiR,CR)-2 and (SiS,CR)-3 produccd by T. variabilis were obtained in good yields [74% ((SiR,CR)-2). 78% ((SiS,CR)-3)]. The products obtained from the reduction with C. dioxydans were isolated in significantly lower yields [20% ((SiR,CR)-2), 20% ((SiS,CR)-3)]; reaction conditions not optimized). Both bioconversions gave products with high enantiomeric purities (T. variabilis: 91% ee ((SiR,CR)-2), 96% ee ((SiS,CR)-3); C. dioxydons: ~ 991 ee ((SiR,CR)-l), ~ 99% ee ((SiS,CR)-3)). To throw light on the stereochemical aspects of these biotransfonnations, an X-ray diffraction study was carried out on the 3,5-dinitrobenzoate of rac-(SiR,CS/SiS,CR)-3. In addition, 1H NMR spectroscopic stereochemical correlation studies were performed with the (S)-MTPA esters derived from (SiR,CR)-l, (SiS,CR)-3, rac-(SiR,CRjSiS,CS)-2 and rac-(SiR,CSjSiS,CR)-3 [rac-(SiR,CR/ SiS,CS)-2 and rac-(SiR,CS/SiS,CR)-3 were obtained by reduction of rac-1 with LiAIH\(_4\) in diethylether, followed by chromatographic separation of the diastereomers on silica gel]. These stereochemical studies allowed assignment of the absolute configurations and enantiomeric purities of the biotransformation products.
KW - Anorganische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64109
ER -
TY - JOUR
A1 - Waelbroeck, M.
A1 - Camus, J.
A1 - Tastenoy, M.
A1 - Mutschler, E.
A1 - Strohmann, C.
A1 - Tacke, Reinhold
A1 - Lambrecht, G.
A1 - Christophe, J.
T1 - Stereoselectivity of (R)- and (S)-hexahydro-difenidol binding to neuroblastoma M\(_1\), cardiac M\(_2\), pancreatic M\(_3\), and striatum M\(_4\) muscarinic receptors
N2 - (R)-Hexahydro-difenidol has a higher affinity for M\(_1\) receptors in NB-OK 1 cells, pancreas M\(_3\) and striatum M\(_4\) receptors (pKi 7.9 to 8.3) than for cardiac M2 receptors (pKi 7 .0). (8)-Hexahydro-difenidol, by contrast, is nonselective (pKi 5.8 to 6.1). Our goal in the present study was to evaluate the importance ofthe hydrophobic phenyl, and cyclohexyl rings of hexahydro-difenidol for the stereoselectivity and reeeptor selectivity of hexahydro-difenidol binding to the four muscarinic receptors. Our results indieated that replacement of the phenyl ring of hexahydro-difenidol by a cyclohexyl group <~ dicyclidol) and ofthe cyclohexyl ring by a phenyl moiety <~ difenidol) indueed a !arge (4- to 80-fold) decrease in binding affinity for all musearlnie receptors. Difenidol had a signifieant preference for M\(_1\) , M\(_3\) , and M\(_4\) over M\(_2\) receptors; dicyclidol, by eontrast, had a greater affinity for M\(_1\) and M\(_4\) than for M\(_2\) and M\(_3\) receptors. The binding free energy deerease due to replacement ofthe phenyl and the cyelohexyl groups of(R)-hexahydro-difenidol by, respectively, a eyclohexyl and a phenyl moiety was almostadditive in the ease of M\(_4\) (striatum) binding sites. In the ease ofthe cardiac M\(_2\), pancreatic M\(_3\) , or NB-OK 1 M\(_1\) receptors the respective binding free energies were not eompletely additive. These results suggest that the four (R)-hexahydro-difenidol ''binding moieties" (phenyl, cyclohexyl, hydroxy, and protonated amino group) cannot simultaneously form optimal interaetions with the M\(_1\), M\(_2\), and M\(_3\) muscarinic receptors. When eaeh of the hydrophobic groups is modified, the position of the whole molecule, relative to the four subsites, was changed to allow an optimal overall interaction with the musearlnie receptor.
KW - Anorganische Chemie
KW - hexahydro-difenidol enantiomers
KW - muscarinic receptor subtypes
KW - stereoselective interaction
KW - difenidol
KW - dicyclidol
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64135
ER -
TY - JOUR
A1 - Gigstad, Kenneth M.
A1 - Ricci JR., John S.
A1 - Markgraf, J. Hodge
A1 - Christl, Manfred
A1 - Kraft, Arno
T1 - Strained Heterocyclic Systems : 18. Structure of 1,2,3-Methylidyne-2,3-dihydro-1H-cyclopenta[b]quinoxaline
N2 - No abstract available
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41645
SN - 0108-2701
ER -
TY - JOUR
A1 - Markgraf, J. H.
A1 - Cort, J. R.
A1 - Davis, H. A.
A1 - Lindeman, N. I.
A1 - Myers, C. R.
A1 - Kraft, A.
A1 - Christl, Manfred
T1 - Strained Heterocyclic Systems. 20. Basicities of Bicyclic Quinoxalines
N2 - No abstract available
KW - Organische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58584
ER -
TY - JOUR
A1 - Feuerstein, G.
A1 - Zerbe, R. L.
A1 - Sirén, Anna-Leena
T1 - Supraoptic nuclei in vasopressin and hemodynamic responses to hemorrhage in rats
N2 - CARDIOVASCULAR and vasopressin (A VP) responses to hcmorrhagc wcrc studicd in rats with lesions of the hypothalamic supraoptic nuclei (SONL). Bleeding caused hypotension and increase in heart rate (HR) and A VP. SONL rats failed to fully recover from bleeding as compared to normal rats. Plasma A VP in SONL rats was in the normal in basal conditions, but failed to increase to levels attained in normal rats throughout the post-hemorrhage period. These data suggcst that the supraoptic nuclei are the primary regulatory sitcs for A VP release in rcsponse to hemorrhage and that lack of adequate A VP release significantly retards blood pressure recovery after bleeding.
KW - Neurobiologie
KW - Hypothalamus
KW - Supraoptic nucleus
KW - Hemorrhage
KW - Vasopressin
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63057
ER -
TY - JOUR
A1 - Hengelsberg, H.
A1 - Tacke, Reinhold
A1 - Fritsche, K.
A1 - Syldatk, C.
A1 - Wagner, F.
T1 - Synthesis and enantioselective enzymatic hydrolysis of rac-dimethylphenyl[1-(phenylacetamido)- ethyl]silane
N2 - Racemic dimethylphenyl(l-(phenylacetamido)ethyl)silane [rac-5) has been made by a four-step synthesis starting from (chloromethyl)dimethylphenylsilane [PhMe\(_2\)SiCH2Cl (1) ~ PhMe\(_2\)SiCH(Cl)Me (rac-2) - PhMe\(_2\)SiCH(l)Me (rac-3) - PhMe2SiCH(NH2)Me (rac-4) ~ PhMe\(_2\)SiCH[N(H)C(O)CH\(_2\)Ph]Me ( rac-5); total yield 41% ). Enantioselective enzymatic hydrolysis of rac-5, catalyzed by immobilized penicillin G acylase (E.C. 3.5.1.11) from Escherichia coli 5K (pHM 12), gave (R)-(1- aminoethyl)dimethylphenylsilane [( R )-4] in 40% yield with an enantiomeric purity of 92% ee.
KW - Anorganische Chemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64153
ER -