TY - BOOK
ED - Mälzer, Gottfried
ED - Baumann, Brigitte
T1 - Würzburger Hochschulschriften : 1804 - 1885 ; Bestandsverzeichnis
N2 - Die Universitätsbibliothek Würzburg hat für ihre umfangreiche Sammlung alter Würzburger Hochschulschriften einen Katalog erarbeitet, der hauptsächlich Dissertationen und Thesen verzeichnet, aber auch andere Prüfungsarbeiten, die für den Erwerb unterschiedlicher akademischer Grade und Titel ausgearbeitet und publiziert worden sind. Dies ist der 2. Band der Nachweise für die Jahre 1804 bis 1885 mit 2510 Titeln.
KW - Universität
KW - Universitätsbibliothek
KW - Hochschulschrift
KW - Würzburg
KW - Verzeichnis
KW - 19. Jahrhundert
KW - university
KW - University Library Wuerzburg
KW - theses
KW - catalog
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-69743
ER -
TY - JOUR
A1 - Segev, Y.
A1 - Rager-Zisman, B.
A1 - Isakov, N.
A1 - Schneider-Schaulies, Sibylle
A1 - ter Meulen, V.
A1 - Udem, S. A.
A1 - Segal, S.
A1 - Wolfson, M.
T1 - Reversal of measles virus mediated increase of phosphorylating activity in persistently infected mouse neuroblastoma cells by anti measles antibodies
N2 - No abstract available
KW - Virologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62362
ER -
TY - JOUR
A1 - Schneider-Schaulies, Sibylle
A1 - Schneider-Schaulies, Jürgen
A1 - Schuster, A.
A1 - Bayer, M.
A1 - Pavlovic, J.
A1 - ter Meulen, V.
T1 - Cell type specific MxA-mediated inhibition of measles virus transcription in human brain cells
N2 - No abstract available
KW - Virologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62255
ER -
TY - CHAP
A1 - Künzler, Jan
T1 - Partnerschaft und Elternschaft im Familiensystem
N2 - Partnerschaft und Elternschaft waren im Begriff der Familie bislang essentiell zusammengedacht: Partnerschaft und Elternschaft, Ehe und Filiation, beschreiben exklusiv und vollständig die Prinzipien, anhand derer sich das Familienpersonal rekrutiert (vgl. Tyrell 1983, S. 363). Beides muß nicht in Familien zusammenfallen. Immer mehr Ehen bleiben dauerhaft kinderlos -immer mehr Familien kommen als Ein-Elternfamilien ohne Partnerschaft aus. Das ist die sozialstrukturelle Version einer Entkoppelung von Partnerschaft und Elternschaft. Auf der anderen Seite sind Partnerschaft und Elternschaft in der überwiegenden Zahl der Fälle immer noch in Familien "fusioniert".
KW - Partnerschaft
KW - Elternschaft
KW - Familienkonflikt
KW - Systemische Therapie
KW - Kongress
KW - Bielefeld <1991>
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-50795
ER -
TY - JOUR
A1 - Heinsen, Helmut
A1 - Henn, R.
A1 - Eisenmenger, W.
A1 - Götz, M.
A1 - Bohl, J.
A1 - Bethke, B.
A1 - Lockermann, U.
A1 - Püschel, K.
T1 - Quantitative investigations on the human entorhinal area: left - right asymmetry and age-related changes
N2 - The total nerve cell numbers in the right and in the left human entorhinal areas have been calculated by volume estimations with the Cavalieri principle and by cell density determinations with the optical disector. Thick gallocyanin-stained serial frozen sections through the parahippocampal gyrus of 22 human subjects (10 female, 12 male) ranging from 18 to 86 years were analysed. The laminar composition of gallocyanin (Nissl)-stained sections could easily be compared with Braak's (1972, 1980) pigmentoarchitectonic study, and Braak's nomenclature of the entorhinal laminas was adopted. Cellsparse laminae dissecantes can more clearly be distinguished in Nissl than in aldehydefuchsin preparations. These cell-poor dissecantes, lamina dissecans extema (dis-ext), lamina dissecans 1 (dis-1) and lamina dissecans 2 (dis-2), were excluded from nerve cell nurober determinations. An exact delineation of the entorhinal area is indispensable for any kind of quantitative investigation. We have defined the entorhinal area by the presence of pre-alpha ceil clusters and the deeper layers of lamina principalis externa (pre-beta and gamma) separated from lamina principalis interna (pri) by lamina dissecans 1 (dis-1). The human entorhinal area is quantitatively characterized by a left-sided (asymmetric) higher pre-alpha cell number and an age-related nerve cell loss in pre as well as pri layers. At variance with other CNS cortical and subcortical structures, the neuronal number of the entorhinal area appears to decrease continuously from the earliest stages analysed, although a secular trend has to be considered. The asymmetry in pre-alpha cell number is discussed in the context of higher human mental capabilities, especially language.
KW - Medizin
KW - Human entorhinal area
KW - Ageing
KW - Lateralitity
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59946
ER -
TY - JOUR
A1 - Schwarz, Klaus
A1 - Hameister, Horst
A1 - Gessler, Manfred
A1 - Grzeschik, Karl-Heinz
A1 - Hansen-Hagge, Thomas E.
A1 - Bartram, Claus R.
T1 - Confirmation of the localization of the human recombination activating gene 1 (RAG1) to chromosome 11p13
N2 - The human recombination activating gene 1 (RAGl) has previously been mapped to chromosomes 14q and 11 p. Here we confirm the chromosome 11 assignment by two independent approaches: autoradiographic and fluorescence in situ hybridization to metaphase spreads and analysis of human-hamster somatic cell hybrid DNA by the polymerase chain reaction (PCR) and Southern blotting. Our results unequivocally localize RAG1 to llp13.
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59136
ER -
TY - JOUR
A1 - Fischer, W. H.
A1 - Lutz, Werner K.
T1 - Short communication : Mouse skin papilloma formation by chronic dermal application of 7,12-dimethylbenz[a]anthracene is not reduced by diet restriction
N2 - No abstract available
KW - Toxikologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60644
ER -
TY - JOUR
A1 - Grunicke, H.
A1 - Pyerin, W.
A1 - Eisenbrand, G.
A1 - Havemann, K.
A1 - Rabes, H. M.
A1 - Molling, K.
A1 - Schwab, M.
A1 - Lutz, Werner K.
A1 - Wahrendorf, J.
A1 - Schirrmacher, V.
T1 - 7th International Symposium of the Division of Experimental Cancer Research (AEK) of the German Cancer Society : [Meeting report]
N2 - No abstract available
KW - Toxikologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60651
ER -
TY - JOUR
A1 - Sendtner, Michael
A1 - Dittrich, F.
A1 - Hughes, R. A.
A1 - Thoenen, H.
T1 - Actions of CNTF and neurotrophins on degenerating motoneurons : preclinical studies and clinical implications
N2 - Spinal motoneurons innervating skeletal muscle were amongst the first neurons shown to require the presence of their target cells to develop appropriately. Isolated embryonie chick and rat motoneurons have been used to identify neurotrophic factors and cytokines capable of supporting the survival of developing motoneurons. Such factors include ciliary neurotrophic factor (CNTF), which is present physiologically in high amounts in myelinating Schwann cells of peripheral nerves, and brain-derived neurotrophic factor (BDNF) which is synthesized in skeletal muscle and, after peripheral nerve lesion. in Schwann cells. These factors have been further analyzed for their physiological significance in maintaining motoneuron function in vivo, and for their potential therapeutic usefulness in degenerative motoneuron disease. Both CNTF and BDNF are capable of rescuing injured facial motoneurons in newbom rats. Furthermore, CNTF prolongs survival and improves motor function of pmn mice, an animal model for degenerative motoneuron disease, by preventing degeneration of motoneuron axons and somata. Thus treatment of human motoneuron disease with neurotrophic factors should be possible, provided that rational means for application of these factors can be established considering also the appearance of potential side effects.
KW - Neurobiologie
KW - Motor neuron disease; Ciliary neurotrophic factor; Brain-derived neurotrophic factor; Animal models; Neurotrophic factors
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62939
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Türk, M.
A1 - Peters, K.
A1 - Peters, E.-M.
A1 - Schnering, H. G. von
T1 - Octahydro-1,2,3:4,5,6-dimethenopentalen-2-carbonitril, das erste Derivat eines noch unbekannten (CH)\(_{10}\)-Kohlenwasserstoffs
N2 - No abstract available
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58728
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Türk, M.
A1 - Peters, K.
A1 - Peters, E.-M.
A1 - Schnering, H. G. von
T1 - Octahydro-1,2,3:4,5,6-dimethenopentalene-2-carbonitrile, the First Derivative of a Yet-Unknown (CH)\(_{10}\)-Hydrocarbon
N2 - No abstract available
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58731
ER -
TY - JOUR
A1 - Bentley, T. W.
A1 - Christl, Manfred
A1 - Kemmer, R.
A1 - Llewellyn, G.
A1 - Oakley, J. E.
T1 - Kinetic and Spectroscopic Characterisation of Highly Reactive Methanesulfonates. Leaving Group Effects for Solvolyses and Comments on Geminal Electronic Effects Influencing S\(_N\)1 Reactivity
N2 - Highly reactive methanesulfonates (mesylates, ROMs) have been prepared from 1-phenylethanol. cyclohex-2-en-1-ol, diphenylmethanol and p-methoxybenzyl alcohol by treatment with methanesulfonyl chloride and triethylamine in dichloro- or trichloro-methane at - 20 to 0 °C. The mesylates. characterised in solution by \(^1\)H and \(^{13}\)C NMR at -20 °C, were obtained in satisfactory purity (ca. 95%) in cold solutions but they decomposed by reaction with chloride, triethylamine or the parent alcohol. Rate constants for solvolyses in aqueous acetone and aqueous ethanol have been determined by a fast response conductimetric method. Product selectivities for solvolyses of pmethoxybenzyl mesylate in aqueous ethanol and methanol at 0 °C have been determined by HPLC. From additional new or Iiterature kinetic data for solvolyses of corresponding bromides. chlorides and p-nitrobenzoates (OPNB). Br/CI. OMs/Br and OMs/OPNB rate ratios were calculated; the results are consistent with electronic effects stabilising the carbocationic transition states and increasing OMs/Br rate ratios for these SN 1 solvolyses; none of the evidence supports a geminal electronic effect on Br/CI rate ratios (e.g. caused by stabilisation of the initial state in pmethoxybenzyl chloride). Steric effects on ester /halide rate ratios for solvolyses of tertiary substrates are confirmed. Relative rates over a 10\(^{16}\) range for ester and halide leaving groups are evaluated for solvolyses of 1-phenylethyl substrates in 80% ethanol-water. updating previous work by Noyce et al. (1972).
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58748
ER -
TY - JOUR
A1 - Herbert, M. K.
A1 - Holzer, P.
T1 - Nitric oxide mediates the amplification by interleukin-1β of neurogenic vasodilatation in the rat skin
N2 - No abstract available.
KW - Medizin
KW - Afferent nerve stimulation
KW - Capsaicin
KW - Cutaneous hyperemia
KW - lnterleukin-lβ
KW - Neurogenie inflammation
KW - Nitric oxide (NO)
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59969
ER -
TY - JOUR
A1 - Schwartz, Faina
A1 - Neve, Rachel
A1 - Eisenman, Robert
A1 - Gessler, Manfred
A1 - Bruns, Gail
T1 - A WAGR region gene between PAX-6 and FSHB expressed in fetal brain
N2 - Developmental delay or mental retardation is a frequent component of multi-system anomaly syndromes associated with chromosomal deletions. Isolation of genes involved in the mental dysfunction in these disorders should define loci important in brain formation or function. We have identified a highly conserved locus in the distal part of 11 p 13 that is prominently expressed in fetal brain. Minimal expression is observed in a number of other fetal tissues. The gene maps distal to PAX-6 but proximal to the loci for brain-derived neurotrophic factor (BDNF) and the beta subunit of follicle stimulating hormone (FSHB), within a region previously implicated in the mental retardation component of some WAGR syndrome patients. Within fetal brain, the corresponding transcript is prominent in frontal, motor and primary visual cortex as weil as in the caudate-putamen. The characteristics of this gene, including the striking evolutionary conservation at the locus, suggest that the encoded protein may function in brain development.
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59125
ER -
TY - JOUR
A1 - Probstmeier, R.
A1 - Bilz, A.
A1 - Schneider-Schaulies, Jürger
T1 - Expression of the neural cell adhesion molecule and polysialic acid during early mouse embryogenesis
N2 - The expression of the neural cell adhesion molccule (N-CAM) and a 2-8 linked polysialic acid (PSA), whieh is believed to be predominantly expressed on N-CAM, was investigated during early embryonie development ofthe mouse (embryonic days 7.5 to 10.0). By immunoeytoehemistry, in tissue sections, N-CAM and PSA were not detectable at embryonie day 7.5 but were expressed in the prominent body regions such as somites, unsegmented mesoderm, developing heart, and neuroectoderm at embryonie day 8.0 N-CAM and PSA immunoreaetivities were always predominantly associated with tbe plasma membrane. No tissue could be detected which was positive for PSA but negative for N-CAM. In Western blot analysis of whole embryos, by contrast, only the lightly sialylated and PSA-negative 180 and 140 kD isoforms of N-CAM werc present at embryonie day 8.0 and strong expression of PSA-bearing, heavily sialylated N-CAM was not detectable before embryonie day 10.0. In Western blot analysis of N-CAM immunoaffinity purifled from whole embryos and digested with neuraminidase as weil as in Northern blot analysis, the 120 kD isoform of N-CAM or its eorresponding mRN A were not expressed in detectable amounts during the time period investigated.
KW - Immunologie
KW - embryo
KW - mouse
KW - N-CAM
KW - sialic acid
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54921
ER -
TY - JOUR
A1 - Dunster, L.M.
A1 - Schneider-Schaulies, Jürgen
A1 - Löffler, S.
A1 - Lankes, W.
A1 - Schwartz-Albiez, R.
A1 - Lottspeich, F.
A1 - ter Meulen, V.
T1 - Moesin: a cell membrane protein linked with susceptibility to measles virus infection
N2 - Measles virus is a highly contagious virus causing acute and persistent diseases in man, the receptor of which is still not weil characterized. We have isolated a monoclonal antibody (mAb), designated mAb 119, which specifically inhibits measles virus infection of susceptible celllines in a dosa-dependent manner. This antibody precipitates a protein with an apparent molecular mass of 75 kDa from 1251 surface-labeled cells and its epitope is present on human peripheral blood mononuclear cells, human celllines, and the African green monkey cellline Vero. Affinity chromatography of detergent-solubilized cell membrane proteins over a Sepharose column with covalently bound mAb 119 led to the partial purification of the 75-kOa protein. Preincubation of measles virus with this affinity-purified protein inhibited measles virus infection dose dependently. Aminoacid microseq,uencing of this protein revealed its identity with the human membrane-organizing extension spike protein moesin, a protein intra- and extracellularly associated with the plasma membrane of cells. Subsequently, an antibody raised against purified moesin (mAb 38/87) was also found to specifically inhibit measles virus infection of susceptible cells and confirmed our data obtained with mAb 119. Our data suggest that moesin is acting as a receptor for measles virus.
KW - Immunologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54931
ER -
TY - JOUR
A1 - Schneider-Schaulies, Sibylle
A1 - Schnorr, J.-J.
A1 - Dunster, L. M.
A1 - Schneider-Schaulies, Jürgen
A1 - ter Meulen, Volker
T1 - The role of host factors in measles virus persistence
N2 - As critical steps in the life cycle oJ measles virus (Mfl), the e.fficiency of uptake into and replication in susceptible host cells are governed by cellular determinants. Measles virus infections of cells of the human CNS are characterized by particular constraints imposed on v1:ral transcription and translation attenuating viral gene Junctions and thus contributing to the pathogenesis oJ MV persistence in these cells.
KW - Immunologie
KW - CNS infection
KW - MV receptor
KW - MV transcription
KW - unwindase
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54944
ER -
TY - JOUR
A1 - Maisner, A.
A1 - Schneider-Schaulies, Jürgen
A1 - Liszewski, M.K.
A1 - Atkinson, J.P.
A1 - Herrler, G.
T1 - Binding of measles virus to membrane cofactor protein (CD46): importance of disulfide bonds and N-glycans for the receptor function
N2 - Two cellular proteins, membrane cofactor protein (MCP) and moesin, were reported recently to be functionally associated with the initiation of a measles virus infection. We bave analyzed the interaction of measles virus with cell surface proteins, using an overlay binding assay with cellular proteins immobilized on nitrocellulose. Among surface-biotinylated proteins from a human rectal tumor cellline (HRT), measles virus, was able to bind only to a 67-kDa proteinthat was identified as MCP. The virus recognized dift'erent isoforms of MCP expressed from human (HRT and HeLa) and simian (Vero) celllines. The binding of measles virus to MCP was abolished after cleavage of the disulfide bonds by reducing agents as weil as after enzymatic release of N-linked oligosaccharides. By contrast, removal of sialic acid or 0-linked oligosaccharides did not aft'ect the recognition of MCP by measles virus. These data indicate that the receptor determinant of MCP is dependent on a conformation of the protein that is maintained by disulfide bonds and N-glycans present in tbe complement binding domains. Our results are consistent with a roJe of MCP as primary attacbment site for measles virus in the initial stage of an infection. The functional relationship between MCP and moesin in a measles virus infection is discussed.
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34324
ER -
TY - JOUR
A1 - Schneider-Schaulies, Jürgen
A1 - Schneider-Schaulies, S.
A1 - Schuster, A.
A1 - Bayer, M.
A1 - Pavlovic, J.
A1 - ter Meulen, V.
T1 - Cell type specific MxA-mediated inhibition of measles virus transcription in human brain cells
N2 - Measles virus (MV)-specific transcription in human brain cells is characterized by particularly low abundances of the distal mRNAs encoding the MV envelope proteins. Similar transcriptional restrictions of the closely related vesicular stomatitis virus have been observed in mouse fibroblasts constitutively expressing the interferon-inducible MxA protein (P. Staeheli and J. Pavlovic, J. Virol. 65:4498-4501, 1991). We found that MV infection of human brain cells is accompanied by rapid induction and high-level expression of endogenous MxA proteins. After stable transfection of MxA, human glioblastoma cells (U-87-MxA) released 50- to 100-fold less infectious virus and expression of viral proteinswas highly restricted. The overall MV-specific transcription Ievels were reduced by up to 90%, accompanied by low relative frequencies of the distal MV-specific mRNAs. These restrictions were linked to an inhibition of viral RNA synthesis and not to a decreased stability of the viral RNAs. Our results indicate that expression of MxA is associated with transcriptional attenuation of MV in brain cells, thus probably contributing to the establishment of persistent MV central nervous system infections. In addition, the mechanism of MxA-dependent resistance against MV infection, in contrast to that of vesicular Stomatitis virus, is cell type specific, because an inhibition of MV glycoprotein synthesis independent of transcriptional alterations was observed in MxA-transfected human monocytes
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34313
ER -
TY - JOUR
A1 - Rabinowitz, Mitchell
A1 - Ornstein, Peter A.
A1 - Folds-Bennett, Trisha H.
A1 - Schneider, Wolfgang
T1 - Age-related differences in speed of processing: Unconfounding age and experience
N2 - No abstract available
KW - Psychologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62223
ER -
TY - JOUR
A1 - Bjorklund, David F.
A1 - Schneider, Wolfgang
A1 - Cassel, William S.
A1 - Ashley, Elizabeth
T1 - Training and Extension of a Memory Strategy: Evidence for Utilization Deficiencies in the Acquisition of an Organizational Strategy in High- and Low-IQ Children
N2 - 143 9- and 10-year-oId children were classified into high- and Jow-IQ groups and given 4 different sort/recall lists (baseline, training, near [immediate] extension, far [l-week] extension) to assess training and extension of an organizational memory strategy. All children received categorized items of moderate typicality for Phases 1, 3, and 4. For Phase 2, children were assigned to either a training or control group, with half of the children in each group receiving category typical items and the others category atypical items. Levels of recall, sorting, and clustering were greater in Phase 2 for high-IQ children, for the typical lists, and for trained children. Both the high- and low-IQ children trained with typical items continued to show high levels of recall on the near extension phase. No group of subjects maintained high levels of recall after 1 week, although levels of sorting and/or clustering on the extension trials remained high for all groups of subjects except the low-IQ control children. This latter pattern (elevated sorting/clustering with low levels of recall) is an indication of a utilization deficiency, a phase in strategy development when children use a strategy but gain little or no benefit n performance. The results provide evidence for IQ, training, and material effects in the demonstration of a utilization deficiency.
KW - Psychologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62234
ER -
TY - JOUR
A1 - Kurtz-Costes, Beth E.
A1 - Schneider, Wolfgang
T1 - Self-concept, attributional beliefs, and school achievement: A longitudinal analysis
N2 - No abstract available
KW - Psychologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62245
ER -
TY - JOUR
A1 - Stopper, Helga
A1 - Kühnel, A.
A1 - Podschun, B.
T1 - Combination of the chemotherapeutic agent 5-fluorouracil with an inhibitor of its catabolism results in increased micronucleus induction
N2 - The rate limiting step in 5-fluorouracil catabolism is catalyzed by the enzyme dihydropyrimidine dehydrogenase. Since degradation of 5-fluorouracil decreases its efficacy in chemotherapy, the inhibition of its catabolism is a promising tool. We investigated the formation of micronuclei in vitro in mouse L5178Y cells. 5-fluorouracil induced an increase in micronucleus frequency, which could significantly be enhanced by the concurrent application of 2,6-dihydroxypyridine, an inhibitor of dihydropyrimidine dehydrogenase. The 5-fluorouracil concentration necessary to reach maximal genotoxic effects could be reduced to half in the presence of inhibitor. 2,6-Dihydroxypyridine alone and the naturally occuring enzyme substrate uracil did not induce micronucleus formation. Combined application of the chemotherapeutic agent 5-fluorouracil and an inhibitor of its could reduce side-effects by lowering the effective dose of the active drug. With this study we provide further support for the usefulness of this concept.
KW - Toxikologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63383
ER -
TY - JOUR
A1 - Stopper, Helga
A1 - Eckert, I.
A1 - Schiffmann, D.
A1 - Spencer, D. L.
A1 - Caspary, W. J.
T1 - Is micronucleus induction by aneugens an early event leading to mutagenesis?
N2 - This study was designed to investigate a previously unidentified potential mechanism for mutation induction as well as to clarify a biological comequence of micronucleus formation. We compared the induction of micronuclei with mutation inductioo as measured by trißuorothymidine (TFI') resistance in mouse L5178Y cells using four aneugens: colcemid, diethylstilbestrol, griseofulvin and vioblastine. AU four compounds induced micronuclei which appeared in the first cell cycle after treatment. More than 85% of the micronuclei induced by each compound stained positive for the presence of kinetochores implying that the micronuclei contained wbole cbromosomes. However, these same compounds were unable to induce TFf resistance under tbree different treatment regimes. We concluded that tbese compounds, under conditions where tbey induce primarily kinetochore positive micronuclel, were not able to induce mutations. Thus, the induction of micronuclei containing wbole chromosomes barborlog a select.able gene is not an early event leadlog to mutations in these cells.
KW - Toxikologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63390
ER -
TY - RPRT
A1 - McCarron, R. M.
A1 - Doron, D. A.
A1 - Sirén, Anna-Leena
A1 - Feuerstein, G. Z.
A1 - Heldman, E.
A1 - Pollard, H. B.
A1 - Spatz, M.
A1 - Hallenbeck, J. M.
T1 - Agonist-stimulated release of von Willebrand factor and procoagulant factor VIII in rats with and without risk factors for stroke [Research Report]
N2 - Lipopolysaccharidc (LPS)-induced (i.v. or i.c.v., 1.8 mg/kg) release of von Willebrand factor (vWF) ·was examined in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. SHR rats releascd significantly (P < 0.05) more vWF than WKY rats in response to LPS. LPS also inhibited factor VIII procoagulant activity (FVIII: c) which may indicate an increase in thrombin activity. Cultured cerebrovascular endothelial cells (EC) derived from both SHR and WKY rats, as weil as human umbilical vein EC (HUVEC) cultures constitutively released vWF. Treatment with agonists including LPS, thrombin and tumor necrosis factor-a (TNFa) did not affect the in vitro secretion of vWF by cerebrovascular EC cultures but significantly upregulated vWF release by HUVEC cultur~s. Preincubation of cerebrovascular EC cultures with interleukin-1 OL-l) ± TNFa or co-culturing in the presence of LPS-activated syngeneic monocytes had no effect on vWF secretion. The findings demoostrate that conditions of hypertension may affect endothelial cells and make them more responsive to agonist Stimulation and thereby increase secretion of vWF, an important factqr in hemostasis as weil as thrombosis. The capacity of LPS to significantly affect the in vivo secretion of vWF in SHR and WKY rats but not cultured cerebrovascular EC indicates that observed elevations in plasma vWF were not derived from cerebrovascular EC. lt is suggested that hypertension may function as a risk factor for thrombotic stroke by influencing factors involved in coagulation processes, such as vWF and factor VIII : c.
KW - Neurobiologie
KW - von Willebrand factor
KW - Hypertension
KW - Lipopolysaccharide
KW - Endothelial cell
KW - Stroke
KW - Monocyte
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62945
ER -
TY - RPRT
A1 - Wang, X.
A1 - Sirén, Anna-Leena
A1 - Liu, Y.
A1 - Yue, T-L.
A1 - Barone, F. C.
A1 - Feuerstein, G. Z.
T1 - Upregulation of intercellular adhesion molecule-1 (ICAM-1) on brain microvascular endothelial cells in rat ischemic cortex [Research Report]
N2 - The expression of intercellular adhesion molecule 1 (ICAM-1) was studied in rat focal ischemic cortex. A significant increase in ICAM-1 mRNA expression in the ischemic cortex over Ievels in contralateral (nonischemic) site was observed by means of Northern blot analysis following either permanent or temporary occlusion with reperfusion of the middle cerebral artery (PMCAO or MCAO with reperfusion) in spontaneously hypertensive rats. In the ischemic cortex, Ievels of ICAM-1 mRNA increased significantly at 3 h (2.6-fold, n = 3, P < 0.05), peaked at 6 to 12 h (6.0-fold, P < 0.01) and remained elevated up to 5 days (2.5-fold, P < 0.05) after PMCAO. The profile of ICAM-1 mRNA expression in the ischemic cortex following MCAO with reperfusion was similar to that following PMCAO, except that ICAM-1 mRNA was significantly increased as early as 1 h (6.3-fold, n = 3, P < 0.05) and then gradually reached a peak at 12 h (12-fold, P < 0.01) after reperfusion. ICAM-1 mRNA expression in ischemic cortex following PMCAO was significantly greater in hypertensive rats than in two normotensive rat strains. Immunostaining using anti-ICAM-1 antiborlies indicated that upregulated ICAM-1 expressionwas localized to endotheIial cells of intraparenchymal blood vessels in the ischemic but not contralateral cortex. The data suggest that an upregulation of ICAM-1 mRNA and protein on brain capillary endothelium may play an important rote in leukocyte migration into ischemic brain tissue.
KW - Neurobiologie
KW - Intercellular adhesion molecule 1
KW - Focal brain ischemia
KW - Stroke
KW - Reperfusion
KW - lnflammation
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62952
ER -
TY - JOUR
A1 - McCarron, R. M.
A1 - Wang, L.
A1 - Sirén, Anna-Leena
A1 - Spatz, M.
A1 - Hallenbeck, J. M.
T1 - Monocyte adhesion to cerebromicrovascular endothelial cells derived from hypertensive and normotensive rats
N2 - No abstract available
KW - Neurobiologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62960
ER -
TY - JOUR
A1 - Schartl, A.
A1 - Dimitrijevic, N.
A1 - Schartl, Manfred
T1 - Evolutionary origin and molecular biology of the melanoma-inducing oncogene of Xiphophorus
N2 - No abstract available
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61954
ER -
TY - CHAP
A1 - Gotz, R.
A1 - Schartl, Manfred
T1 - The conservation of neurotrophic factors during vertebrate evolution
N2 - No abstract available
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61964
ER -
TY - JOUR
A1 - Lubjuhn, T.
A1 - Schartl, Manfred
A1 - Epplen, J. T.
T1 - Methodik und Anwendungsgebiete des genetischen Fingerabdruckverfahrens
N2 - No abstract available
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61978
ER -
TY - CHAP
A1 - Heiser, A.
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, W.
T1 - Enzyme Kinetics of Commercial Collagenases and their Influence on Porcine Islet Isolation
N2 - No abstract available
KW - Heterotransplantation
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45488
ER -
TY - BOOK
A1 - Künzler, Jan
T1 - Familiale Arbeitsteilung : Die Beteiligung von Männern an der Hausarbeit
N2 - No abstract available
KW - Mann
KW - Hausarbeit
KW - Statistik
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-50726
SN - 3-89370-194-X
ER -
TY - JOUR
A1 - Wieber, Markus
A1 - Lang, Stefan
A1 - Rohse, Stefan
A1 - Habersack, Ralph
A1 - Burschka, Christian
T1 - Synthese und Kristallstruktur von Triphenyltelluroniumsulfid
T1 - Synthesis and Crystal Structure of Triphenyltelluroniumsulfide
N2 - No abstract available
KW - Chemie
KW - Triphenyltelluroniumsulfide
KW - Synthesis
KW - NMR Data
KW - Crystal Structure
KW - Secondary Bonding
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47151
ER -
TY - JOUR
A1 - Wehgartner, Irma
T1 - Röntgenstrahlen und Archäologie
N2 - Naturwissenschaftliche Untersuchungsmethoden werden heute ganz selbstverständlich zur wissenschaftlichen Erforschung archäologischer Objekte herangezogen. Dies gilt für die Materialbestimmung und die Klärung von Herstellungstechniken ebenso wie für die Feststellung von Alter oder Zugehörigkeit zu einer bestimmten Kulturlandschaft. Zugleich spielen diese Methoden bei der Echtheitsprüfung von Stücken unklarer Provenienz eine nicht unerhebliche Rolle.
KW - Archäologie
KW - Röntgenstrahlung
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53827
ER -
TY - JOUR
A1 - Heinsen, Helmut
A1 - Strik, M.
A1 - Luther, K.
A1 - Ulmar, G.
A1 - Gangnus, D.
A1 - Jungkunz, G.
A1 - Eisenmenger, W.
A1 - Götz, M.
A1 - Bauer, M.
T1 - Cortical and striatal neurone number in Huntington's disease
N2 - The total cortical and striatal neurone and glial numbers were estimated in five cases of Huntington's disease (three males, two females) and five ageand sex-matched control cases. Serial 500-l-lm-thick gallocyanin-stained frontal sections through the left hemisphere were analysed using Cavalieri's principle for volume and the optical disector for cell density estimations. The average cortical neurone number of five controls (mean age 53±13 years, range 36-72 years) was 5.97x 109±320x 106 , the average number of small striatal neurones was 82 X 106± 15.8 X 106• The left striatum (caudatum, putamen, and accumbens) contained a mean of 273 X 106±53 X 106 glial cells (oligodendrocytes, astrocytes and unc1assifiable glial profiles). The mean cortical neurone number in Huntington's disease patients (mean age 49±14 years, range 36-75 years) was diminished by about 33 % to 3.99x109±218x106 nerve cells (P ::;:::: 0.012, MannWhitney V-test). The mean number of small striatal neurones decreased tremendously to 9.72 X 106 ± 3.64 X 106 (-88 % ). The decrease in total glial cells was less pronounced (193 X 106±26 X 106) but the mean glial index, the numerical ratio of glial cells per neurone, increased from 3.35 to 22.59 in Huntington's disease. Qualitatively, neuronal loss was most pronounced in supragranular layers of primary sensory areas (Brodmann's areae 3,1,2; area 17, area 41). Layer HIc pyramidal cells were preferentially lost in association areas of the temporal, frontal, and parietal lobes, whereas spared layer IV granule cells formed a conspicuous band between layer IH and V in these fields. Methodological issues are discussed in context with previous investigations and similarities and differences of laminar and lobar nerve cellloss in Huntington's disease are compared with nerve cell degent-ration in other neuropsychiatric diseases.
KW - Medizin
KW - Huntington's disease . Human cerebral cortex
KW - Striatum
KW - Neurone number
KW - Stereology
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-55217
ER -
TY - CHAP
A1 - Fiala, Brigitte
A1 - Federle, W.
A1 - Maschwitz, U.
A1 - Azarae, Idris
T1 - The first myrmecophytic 2-partner-system in the genus Macaranga: The association between Macaranga puncticulata and a Componotus (Colobopsis) in Malaysia
N2 - No abstract available
KW - Biologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-55144
ER -
TY - JOUR
A1 - Sponholz, Barbara
T1 - Silicate karst associated with lateritic formations (examples from eastern Niger)
N2 - Silicate and iron crust karst pits and sinkholes in eastern Niger are filled with reworked lateritic sediments or with unconsolidated palaeosoils and aeolian deposits. The fillings facies depend on the environmental conditions during deposition. Geomorphological and sedimentological studies on the karst fillings and the interpretation of various karst/filling associations allow an approach to the chronology of landscape development in eastern Niger plateaus.
KW - Geographie
KW - Silicate
KW - Niger
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53852
ER -
TY - JOUR
A1 - Blackenhorn, Wolf U.
A1 - Perner, Dirk
T1 - Heritability and repeatability of behavioural attributes affecting foraging success and fitness in water striders
N2 - Heritabilities and repeatabilities are presented for various behavioural attributes affecting foraging performance and fitness in Aquarius (Gerris) remigis (Heteroptera: Gerridae) females. These behavioural attributes were patch choice, foraging success, capture accuracy, and measures of mobility, activity, skittishness and aggressiveness. Most heritabilities were not significantly different from zero, which may be related to the low sampIe size. Conclusions as to the potential of direct selection on behaviour in this species were consequently limited. In contrast, with a few exceptions (capture accuracy, foraging success), most repeatabilities were significant and at times high (range=O'22-O'79), indicating consistent, stereotypical individual behaviour. Tbe Iife history or reproductive state of the daughter generation individuals signifieantly affected the magnitude of the repeatabilities as weil as the mean values of many of the variables (notably mobility and aggressiveness), the latter in a manner consistent with field observations. This indicates that the state of the organism affects the general environmental variance, thus contributing to the discrepancies between the repeatabilities and the heritabilities obtained. It is suggested that common physiological proeesses (e.g. hormones) may underlie several of the behavioural attributes examined, resulting in possible pleiotropie effects and eonstraints on selection in a heterogeneous environment. It is further suggested that field studies of selection on behavioural attributes may be a more fruitful approach in this species, whose suitability for genetic analysis is limited.
KW - Teichläufer
KW - Wasserläufer
KW - water strider
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-52496
ER -
TY - JOUR
A1 - Ulrichs, Karin
A1 - Bosse, M.
A1 - Wacker, HH
A1 - Heiser, A.
A1 - Müller-Ruchholtz, W.
T1 - Histologic analysis of the porcine pancreas to improve islet yield and integrity after collagenase digestion
N2 - No abstract available
KW - Chirurgie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45166
ER -
TY - JOUR
A1 - Ulrichs, Karin
A1 - Eckstein, V.
A1 - Müller-Buchholtz, W.
T1 - Xenogeneic T-cell-mediated immune reactivity in the model of pig-to-humans: first findings with native stimulator cells
N2 - No abstract available
KW - Chirurgie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44755
ER -
TY - JOUR
A1 - Eckstein, V.
A1 - Müller-Buchholtz, W.
A1 - Ulrichs, Karin
T1 - Reaction patterns of natural xenophile antibodies in human sera with pancreatic islet cells and porcine lymphocytes
N2 - No abstract available
KW - Chirurgie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44742
ER -
TY - JOUR
A1 - Heiser, Axel
A1 - Ulrichs, Karin
A1 - Müller-Buchholtz, Wolfgang
T1 - Isolation of porcine pancreatic islets: low trypsin activity during the isolation procedure guarantees reproducible high islet yields
N2 - During the past few years, interest in xenotransplantation of porcine islets of Langerhans for the future therapy of type I diabetes has Increased markedly. Therefore, we established a semiautomated digestion method for isolating islets from the porcine pancreas. However, although the isolation technique was standardized and collagenase of controlled quality was used, we were unable to attain high islet yields with a satisfactory degree of reproducibility. One hypothesis was that varying degrees of interference by donor pancreatic enzymes were responsible for this failure. The aim of this stUdy was to examine the kinetics of four types of enzymatic activity during the isolation procedure, as well as their effects on islet yield: collagenase, trypsin, neutral protease, and clostripaln. Our results indicate that while exogenous collagenase activity decreases slightly during the isolation procedure, the activity of the pancreas enzymes neutral protease and trypsin increases. In some cases, trypsin activity increases very strongly. A strong increase in trypsin activity correlates with poor islet yield, whereas low trypsin activity always correlates with high islet yield. Addition of the protease inhibitor Pefabloc to the isolation medium results in low trypsin activity and reproducible high islet yields.
KW - Langerhans-Inseln
KW - islets of Langerhans
KW - xenogeneic transplantation
KW - swine
KW - enzyme activation
KW - enzyme inhibitors
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44719
ER -
TY - JOUR
A1 - Heiser, A.
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, W.
T1 - Prophylactic trypsin inhibition during the isolation procedure guarantees reproducible, high porcine islet yields
N2 - Abstract: For isolating islets from the porcine pancreas, we established a semiautomated digestion method. Although the isolation technique was standardized and collagenase of controlled quality was used, until now the reproducibility of high islet yields was unsatisfactory. Our hypothesis was that pancreatic trypsin was responsible for this failure. The aim of this study was to investigate the effect of endogenous trypsin on islet yield. Our results demonstrate that a high trypsin level correlates with poor islet yield, whereas low trypsin activity always correlates with high islet yield. Specific inhibition of trypsin results in low trypsin activity and reproducible, high islet yields.
KW - islets of Langerhans
KW - xenogenic transplantation
KW - swine
KW - enzyme activation
KW - enzyme inhibitors
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45531
ER -
TY - CHAP
A1 - Heiser, A.
A1 - Ulrichs, Karin
A1 - Müller-Ruchholtz, W.
T1 - Enzyme Activities in Commercial Collagenase Preparations and Their Kinetics During Islet Isolation Procedure
N2 - No abstract available
KW - Transplantation
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45633
ER -
TY - JOUR
A1 - Klotz, Karl-Norbert
A1 - Krotec, K. L.
A1 - Gripentrog, J.
A1 - Jesaitis, A. J.
T1 - Regulatory interaction of N-formyl peptide chemoattractant receptors with the membrane skeleton in human neutrophils
N2 - The cytoskeleton and/or membrane skeleton has been implicated in the regulation of N-formyl peptide receptors. The coupling of these chemotactic receptors to the membrane skeleton was investigated in plasma membranes from unstimulated and desensitized human neutrophils using the photoreactive agonist N-formyl-met-leu-phelys-N\(^6\)-[\(^{125}\)I]2(p-azidosalicylamido)ethyl-1,3'-dithiopropionate (fMLFK-[\(^{125}\)I]ASD). When membranes of unstimulated cells were solubilized in Triton-X 100, a detergent that does not disrupt actin filaments, only 50% of the photoaffinity-labeled receptors were solubilized sedimenting in sucrose density gradients at a rate consistent with previous reports. The remainder were found in the pellet fraction along with the membrane skeletal actin. Solubilization of the membranes in the presence of p-chloromercuriphenylsulfonic acid, elevated concentrations of KCI, or deoxyribonuclease I released receptors in parallel with actin. When membranes from neutrophils, desensitized by incubation with fMLFK-e 251]ASD at 15°C, were solubilized, nearly all receptors were recovered in the pellet fraction. lncubation of cells with the Iigand at 4°C inhibited desensitization partially and prevented the conversion of a significant fraction of receptors to the form associated with the membrane skeletal pellet. ln these separations the photoaffinity-labeled receptors not sedimenting to the pellet cosedimented with actin. Approximately 25% of these receptors could be immunosedimented with antiactin antibodies suggesting that N-formyl peptide receptors may interact directly with actin. These results are consistent with a regulatory role for the interaction of chemotactic N-formyl peptide receptors with actin of the membrane skeleton.
KW - Toxikologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60466
ER -
TY - JOUR
A1 - Klotz, Karl-Norbert
A1 - Jesaitis, A. J.
T1 - Neutrophil chemoattractant receptors and the membrane skeleton
N2 - Signal transduction via receptors for N-formylmethionyl peptide chemoattractants (FPR) on human neutrophils is a highly regulated process which involves participation of cytoskeletal elements. Evidence exists suggesting that the cytoskeleton and/or the membrane skeleton controls the distributJon of FPR in the plane of the plasma membrane, thus controlling the accessibility of FPR to different proteins in functionally distinct domains. In desensitized cells, FPR are restricted todomains which are depleted of G proteins but enriched in cytoskeletal proteins such as actin and fodrin. Thus, the G protein signal transduction partners of FPR become inaccessible to the agonist-occupied receptor, preventing cell activation. The mechanism of interaction of FPR with the membrane skeleton is poorly understood but evidence is accumulating that suggests a direct binding of FPR (and other receptors) to cytoskeletal proteins such as actin.
KW - Toxikologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60471
ER -
TY - JOUR
A1 - Klotz, Karl-Norbert
A1 - Jesaitis, A. J.
T1 - Physical coupling of N-formyl peptide chemoattractant receptors to G protein is not affected by desensitization
N2 - Desensitization of N-formyl peptide chemoattractant receptors (FPR) in human neutrophils results in association of these receptors to the membrane skeleton. This is thought to be the critical event in the lateral segregation of receptors and guanyl nucleotide-binding proteins (G proteins) within the plane of the plasma membrane resulting in an interruption of the signaling cascade. In this study we probed the interaction of FPR with G protein in human neutrophils that were desensitized to various degrees. Human neutrophils were desensitized using the photoreactive agonist N-formyl-met-leu-phelys- N\(^\epsilon\)-[\(^{125}\)I]2(p-azidosalicylamido )ethyl-1 ,3 '-dithiopropionate (/MLFK-[\(^{125}\)I]ASD). The interaction if FPR with G protein was studied via a reconstitution assay and subsequent analysis of FPR-G protein complexes in sucrose density gradients. FPR-G protein complexes were reconstituted with solubilized FPR from partially and fully desensitized neutrophils with increasing concentrations of Gi purified from bovine brain. The respective EC\(_{50}\) values for reconstitution were similar to that determined for FPR from unstimulated neutrophils (Bommakanti RK et al., J Bio[ Chem 267: 757~7581, 1992). We conclude, therefore, that the affinity of the interaction of FPR with G protein is not affected by desensitization, consistent with the model of lateral segregation of FPR and G protein as a mechanism of desensitization.
KW - Toxikologie
KW - chemotactic receptors
KW - G proteins
KW - N-formyl peptides
KW - signal transduction
KW - receptor-G protein coupling
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60483
ER -
TY - JOUR
A1 - Klotz, Karl-Norbert
A1 - Jesaitis, A. J.
T1 - The interaction of N-formyl peptide chemoattractant receptors with the membrane skeleton is energy-dependent
N2 - Desensitization of N-fonnyl peptide chemoattractant receptors (FPR) in human neutrophils is thought to be achieved by lateral segregation of receptors and G proteins within the plane of the plasma membrane resulting in an interruption of the signalling cascade. Direct coupling of FPR to membrane skeletal actin appears to be the basis of this process~ however, the molecular mechanism is unknown. In this study we investigated the effect of energy depletion on formation of FPR-membrane skeleton complexes. In addition the effect of the protein kinase C inhibitor stauroporine and the phosphatase inhibitor okadaic acid on coupling of FPR to the membrane skeletonwas studied. Human neutrophils were desensitized using the photoreactive agonist N-formy1-met-leu-phe-1ys-N'[\(^{125}\)I]2(p-azidosalicylamido)ethyl-1,3'-dithiopropionate (fMLFK-[\(^{125}\)I]ASD) after ATP depletion with NaF or after incubation with the respective inhibitors. The interaction of FPR with the membrane skeleton was studied by Sedimentation of the membrane skeleton-associated receptors in sucrose density gradients. Energy depletion of the cells markedly inhibited the formation of FPR-membrane skeleton complexes. This does not appear tobe related to inhibition of protein phosphorylation due to ATP depletion because inhibition of protein kinases and phosphatases bad no significant effect on coupling of FPR to the membrane skeleton. We conclude, therefore, that coupling of FPR to the membrane skeleton is an energy,dependent process which does not appear to require modification of the receptor protein by phosphorylation.
KW - Toxikologie
KW - Chemotactic receptors
KW - G proteins
KW - N-formyl peptides
KW - signal transduction
KW - desensitization
KW - membrane skeleton
KW - receptor-G protein coupling.
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60499
ER -
TY - JOUR
A1 - Kaupp, Martin
A1 - Schnering, Hans Georg von
T1 - Ab Initio Comparision of the (MX\(_2\))\(_2\) Dimers (m=Zn, Cd, Hg; X F, Cl, H), and Study of Relativistic Effects in Crystalline HgF\(_2\)
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59971
ER -
TY - JOUR
A1 - Kaupp, Martin
A1 - Schnering, Hans Georg von
T1 - Origin of the Unique Stability of Condensed-Phase Hg\(_2 ^{2+}\). An ab Initio Investigation of M\(^I\) and M\(^{II}\) Species (M= Zn, Cd, Hg)
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59981
ER -
TY - JOUR
A1 - Kaupp, Martin
A1 - Schnering, Hans Georg von
T1 - The Dominance of Linear 2-Coordination in Mercury Chemistry: Quasirelativistic and Nonrelativistic ab Initio Pseudopotential Study of (HgX\(_2\))\(_2\) (X=F, Cl, Br, I, H)
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59995
ER -
TY - JOUR
A1 - Wissing, Elmo
A1 - Kaupp, Martin
A1 - Boersma, Jaap
A1 - Spek, Anthony L.
A1 - Koten, Gerard van
T1 - Alkylation Reactions of Dialkylzinc Compounds with 1,4- Diaza- 1,3-butadienes: Cationic and radical Anionic Organozinc Intermediates. Molecular Structure of the Cationic Organozinc Species [MeZn(t-BuN=CHCH=N-t-Bu)]O\(_3\)SCF\(_3\) and Me\(_2\)Zn(bpy)(bpy = 2,2' -Bipyridine)
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60008
ER -
TY - JOUR
A1 - Kaupp, Martin
A1 - Dolg, Michael
A1 - Stoll, Hermann
A1 - Schnering, Hans Georg von
T1 - Oxidation State +IV in Group 12 Chemistry : Ab Initio Study of Zinc(IV), Cadmium(IV), and Mercury(IV) Fluorides
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60018
ER -
TY - JOUR
A1 - Müller, T.
A1 - Dieckmann, T.
A1 - Sebald, Walter
A1 - Oschkinat, H.
T1 - Aspects of receptor binding and signalling of interleukin-4 investigated by site-directed mutagenesis and NMR spectroscopy
N2 - Cytokines are hormones that carry information from ceJI to ceH. This information is read from their surface upon binding to transmembrane receptors and by the subsequent initiation of receptor oligomerization. An inftuence on this process through mutagenesis on the hormone surface is highly desirab)e for medical reasons. However, an understanding of hormone-receptor interactions requires insight into the structural changes introduced by the mutations. In this line structural studies on human TL-4 and the medically important IL-4 antagonists YI24D and Y124G are presented. The site a.round YI24 is an important epitope responsible for the a.bility of 11-4 t.o ca.use a signal in the target cells. It is shown that the local main-chain structure around residue 124 in the variants remains unchanged. A strategy is presented here which allows the study of these types of proteins and their variants by NMR which does not require carbon Iabeiied sa.mples.
KW - Biochemie
KW - Interleukin-4
KW - protein structure
KW - NMR
KW - signal transduction
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62444
ER -
TY - JOUR
A1 - Müller, T.
A1 - Sebald, Walter
A1 - Oschkinat, H.
T1 - Antagonist design through forced electrostatic mismatch
N2 - No abstract available
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62408
ER -
TY - JOUR
A1 - Reusch, P.
A1 - Arnold, S.
A1 - Heusser, C.
A1 - Wagner, K.
A1 - Weston, B.
A1 - Sebald, Walter
T1 - Neutralizing monoclonal antibodies define two different functional sites in human interleukin-4
N2 - Human interleukin-4 (IL-4) is a small four-helix-bundle protein which is essential for organizing defense reactions against macroparasites, in particular helminths. Human IL-4 also appears to exert a pathophysiological role during various IgE-mediated allergic diseases. Seven different monoclonal antibodies neutralizing the activity of human IL-4 were studied in order to identify functionally important epitopes. A collection of 41 purified IL-4 variants was used to analyse how defined amino acid replacements affect binding affinity for each individual mAb. Specific amino acid positions could be assigned to four different epitopes. mAbs recognizing epitopes on helix A and/or C interfered with IL-4 receptor binding and thus inhibited IL-4 function. However, other mAbs also inhibiting IL-4 function recognized an epitope on helix D of IL-4 and did not inhibit IL-4 binding to the receptor protein. One mAb, recognizing N-terminal and C-terminal residues, partially competed for binding to the receptor. The results of these mAb epitope analyses confirm and extend previous data on the functional consequences of the amino acid replacements which showed that amino acid residues in helices A and C of IL-4 provide a binding site for the cloned IL-4 receptor and that a signalling site in helix D interacts with a further receptor protein.
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62418
ER -
TY - JOUR
A1 - Demchuk, E.
A1 - Mueller, T.
A1 - Oschkinat, H.
A1 - Sebald, Walter
A1 - Wade, R. C.
T1 - Receptor binding properties of four-helix-bundle growth factors deduced from electrostatic analysis
N2 - Hormones of the hematopoietin class mediate signal transduction by binding to specific transmembrane receptors. Structural data show that the human growth hormone (hGH) forms a complex with a homodimeric receptor and that hGH is a member of a class of hematopoietins possessing an antiparallel 4-a-helix bundle fold. Mutagenesis experiments suggest that electrostatic interactions may have an important influence on hormonereceptor recognition. In order to examine the specificity of hormone-receptor complexation, an analysis was made of the electrostatic potentials of hGH, interleukin-2 (IL-2), interleukin-4 (IL-4), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and the hGH and IL-4 receptors. The binding surfaces of hGH and its receptor, and of IL-4 and its receptor, show complementary electrostatic potentials. The potentials of the hGH and its receptor display approximately 2-fold rotational symmetry because the receptor subunits are identical. In contrast, the potentials of GM-CSF and IL-2 Iack such symmetry, consistent with their known high affinity for hetero-oligomeric receptors. Analysis of the electrostatic potentials supports a recently proposed hetero-oligomeric model for a high-affinity IL-4 receptor and suggests a possible new receptor binding mode for G-CSF; it also provides valuable information for guiding structural and mutagenesis studies of signal-transducing proteins and their receptors.
KW - Biochemie
KW - cytokines
KW - electrostatic potential
KW - hematopoietic receptors
KW - human growth factor
KW - interleukins
KW - molecular recognition
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62424
ER -
TY - JOUR
A1 - Lehrnbecher, T.
A1 - Poot, M.
A1 - Orscheschek, K.
A1 - Sebald, Walter
A1 - Feller, A. C.
A1 - Merz, H.
T1 - Interleukin 7 as interleukin 9 drives phytohemagglutinin-activated T cells through several cell cycles; no synergism between interleukin 7, interleukin 9 and interleukin 4
N2 - The effects of the interlenkins IL-7 and IL-9 on cell cycle progression were investigated by conventional [3H]thymidine incorporation and by the bivariate BrdU/Hoechst technique. 8oth IL· 7 and IL-9 drive phytohemagglutinin-activated T cells through more than one cell cycle, but IL-7 wasmorepotent on cell cycle progression than IL-9. Neither synergistic nor inhibitory effects were seen between various combinations of the lymphokines IL-7, IL-9 and IL-4 compared to each lymphokine alone. When T cells are activated with phytohemagglutinin for 3 days, all or most IL-4 responsive cells respond to IL-7 as weil, whereas only a part of IL-7 responders are IL-4 responders. In contrast, when T cells are activated with phytohemagglutinin for 7 days, the quantitative data of the cell cycle distribution soggest that the population of IL-7 responders is at least an overlapping, if not a real subset of the population of the IL-4 responders.
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62438
ER -
TY - JOUR
A1 - Mühleisen, M.
A1 - Tacke, Reinhold
T1 - Twofold deprotonated citric acid as a bidentate ligand of pentacoordinate silicon: synthesis and structural characterization of the zwitterionic \(\lambda_5\)Si-spirosilicate bis[citrato(2-)-O\(^3\),O\(^4\)][(dimethylammonio)methyl]silicate hydrate
N2 - The zwitterionic \(\lambda_5\) Si-spirosilicate bis[ citrato(2-)-0\(^3\) ,0\(^4\) )[ ( dimethylammonio) methyl]silicate (4) was synthesized by reaction of (MeO)\(_3\)SiCH\(_2\)NMe\(_2\) (3) with citric acid (molar ratio 1 :2) in acetonitrile at room temperature and isolated, after crystallization from water, as the hydrate 4 · H\(_2\)O (yield 81 %). The crystal structure of 4 · H\(_2\)O was studied by single-crystal X-ray diffraction. The alcoxide oxygen atoms and central carboxylate oxygen atoms of two citrato(2-) ligands and one carbon atom coordinate to the silicon atom of 4 · H\(_2\)O. The coordination polyhedron around the pentacoordinate silicon atom (SiO\(_4\)C framework) can be described as a distorted trigonal bipyramid, the two carboxylate oxygen atoms occupying the axial sites. The \(\lambda_5\) Si~silicon(IV) complex 4 also exists in solution (DMSO, H\(_2\)O).
KW - Anorganische Chemie
KW - Silicon
KW - pentacoordinate
KW - Lambda5Si-Spirosilicate
KW - zwitterionic
KW - Citrato(2-)-03
KW - 04ligand
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64388
ER -
TY - JOUR
A1 - Mühleisen, M.
A1 - Tacke, Reinhold
T1 - meso-[1,4-Piperaziniumdiylbis(methylene)]bis{bis[2-methyllactato(2-)-O1,O2]silicate} octahydrate: synthesis and crystal structure analysis of a zwitterionic dispirocyclic \(\lambda^5\)Si,\(\lambda^5\)Si'-disilicate
N2 - The zwitterionic dispirocyclic \(\lambda^5\)Si,\(\lambda^5\)Si'-disilicate meso-[1 ,4-piperaziniumdiylbis( methylene)]bis{ bis[ 2-methyllactato(2-)-O\(^1\),O\(^2\)]silicate} octahydrate (6-8H\(_2\)O) was synthesized by reaction of 1,4-bis[(trimethoxysilyl}methyl] piperazine (8) with 2-methyllactic acid (molar ratio 1:4) in water/acetone (yield 82%). The molecular dinuclear silicon(IV) complex 6 contains two pentacoordinate (formally negatively charged) silicon atoms and two tetracoordinate (formally positively charged) nitrogen atoms. The crystal structure of 6•8H20 was studied by X-ray diffraction.
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64396
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Mühleisen, M.
T1 - Bis[benzilato(2-)-O\(^1\),O\(^2\)][2-(dimethylammonio)ethoxy]silicate: synthesis and structural characterization of a zwitterionic \(\lambda^5\)Si-silicate with a SiO\(_5\) framework
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64400
ER -
TY - JOUR
A1 - Kübler, N.
A1 - Reuther, J.
A1 - Kirchner, T.
A1 - Pfaff, M.
A1 - Müller-Hermelink, H. K.
A1 - Albert, R.
A1 - Sebald, Walter
T1 - IgG monoclonal antibodies that inhibit osteoinductivity of human bone matrix-derived proteins (hBMP/NCP)
N2 - Monoclonal hBMP/NCP (human bone morphogenetic protein anrl associaterl noncollagenous proteins) antiborlies of the lgG class were prorlucerl. In vitro, 12 of 19 hBMP/NCP antiborlies showerl functional inhibition of hBMP/ NCP-induced chondroneogenesis in a neonatal muscle tissue assay. Inducing factors were characterized by their inhibiting antibodies with immunoblotting. Several peptide factors seem to be involved in the cascade of inducerl chondro- and osteogenesis.
KW - Biochemie
KW - bone morphogenetic proteins
KW - neutralizing antibodies
KW - cartilage induction
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62388
ER -
TY - JOUR
A1 - Tony, H. P.
A1 - Shen, B. J.
A1 - Reusch, P.
A1 - Sebald, Walter
T1 - Design of human interleukin-4 antagonists inhibiting interleukin-4-dependent and interleukin-13-dependent responses in T-cells and B-cells with high efficiency
N2 - Human interleukin-4 possesses two distinct sites for receptor activation. A signaHing site, comprising residues near the C-terminus on helix D, determines the efficacy of interleukin-4 signal transduction without affecting the binding to the interleukin-4 receptor a subunit. A complete antagonist and a series of low-efficacy agonist variants of human interleukin-4 could be generated by introducing combinations of two or three negatively charged aspartic acid residues in this site at positions 121, 124, and 125. One of the double variants, designated [R121D,Y124D]interleukin-4, with replacements of böth Arg121 and Tyr124 by aspartic acid residues was completely inactive in all analysed cellular responses. The loss of efficacy in [R121D,Y124D]interleukin-4 is estimated to be larger than 2000-fold. Variant [R121D,Y124D]interleukin-4 was also a perfect antagonist for inhibition of interleukin-13-dependent responses in B-cells and the TF-1 cellline with a K\(_i\) value of approximately 100 pM. In addition, inhibition of both interleukin-4-induced and interleuk.in-13- induced responses could be obtained by monoclonal antibody X2/45 raised against interleukin-4Rm the extracellular domain of the interleuk.in-4 receptor a subunit. These results indicate that efficient interleukin-4 antagonists can be designed on the basis of a sequential two-step activation model. In addition, the experiments indicate the functional participation of the interleukin-4 receptor a subunit in the interleukin-13 receptor system.
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62394
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Pikies, J.
A1 - Wiesenberger, F.
A1 - Ernst, L.
A1 - Schomburg, D.
A1 - Waelbroeck, M.
A1 - Christophe, J.
A1 - Lambrecht, G.
A1 - Gross, J.
A1 - Mutschler, E.
T1 - Sila-biperiden und endo-Sila-biperiden: Synthesen, Kristallstrukturen und antimuscarinische Eigenschaften
N2 - Starting from trichloro(vinyl)silane (Cl\(_3\)SiCH=CH\(_2\)), the musearinic antagonists sila-biperiden [rac-(SiRS,C2SR>-ao-2] and endosila- biperiden [rac-(SiRS,C2SR)-endo-2] were prepared by a seven-step synthesis. Both silanols are configurationally stableininert organic solvents but undergo slow epimerization in aqueous solution (pH 7.4, 32°C) by inversion of the configuration at the silicon atom. The relative configurations of sila-biperiden and endo-sila-biperiden were detennined by single-crystal X-ray diffraction. Both compounds form intennolecular 0-H · · · N hydrogen bonds in the crystal leading to the fonnation of centrosymmetric dimers (sila-biperiden) and infinite chains (endo-sila-biperiden), respectively. Sila-biperiden is a silicon analogue (C/Si exchange) of the antiparkinsonian drug biperiden [rac-(CRS/C2SR}-exo-1]. In functional phannacological experiments, as well as in radioligand competition studies, biperiden, sila-biperiden and endo-sila-biperiden behaved as simple competitive antagonists at muscarinic Ml-, M2-, M3- and M4-receptors. The three compounds displayed the highest affinity for Ml-receptors (pA\(_2\) values: 8.72-8.80; pK\(_i\) values: 8.8-9.1), intermediate affinity for M4- and M3-receptors, and lowest affinity for M2-receptors (pA\(_2\) values: 7.57-7.79; pK\(_i\) values: 7.7-7.8). The affinity profile (Ml >. M4 > M3 > M2) of biperiden, sila-biperiden and endo-sila-biperiden is qualitatively similar to that of the M1-selective muscarinic antagonist pirenzepine. The antimuscarinic properlies of the C/Si analogues biperiden and sila-biperiden are almost identical.
N2 - Die Antimuscarinica Sila-biperiden [rac-(SiRS,C2SR)-exo-2] und endo-Sila-biperiden [rac-(SiRS,C2SR)-endo-2] wurden ausgehend von Trichlor(vinyl)silan (Cl\(_3\)SiCH=CH\(_2\)) durch eine siebenstufige Synthese dargestellt. Die beiden Silanoie sind in inerten organischen Solvenzien konfigurationsstabil, unterliegen aber in wässeriger Lösung (pH 7.4, 3ZOC) einer Epimerisierung durch Inversion der Konfiguration am Silicium-Atom. Die relativen Konfigurationen von Sila-biperiden und endo-Sila-biperiden wurden durch Einkristall-Röntgenstrukturanalysen bestimmt. Beide Verbindungen bilden im Kristall intermolekulare 0-H · · · N-Wasserstoff- Brückenbindungen aus, die zum Aufbau von zentrosymmetrischen Dimeren (Sila-biperiden) bzw. unendlichen Ketten (endo-Sila-biperiden) führen. Sila-biperiden ist ein Silicium-Analogon (C/Si-Austausch) des Antiparkinsonmittels Biperiden [rac-(CRS,C2SR>-ao-1). Sowohl in funktionellen pharmakologischen Untersuchungen als auch in Radioligand-Kompetitionsexperimenten erwiesen sich Biperiden, Sila-biperiden und endo-Sila-biperiden als rein kompetitive Antagonisten an muscarinischen M1-, M2-, M3- und M4-Rezeptoren. Alle drei Verbindungen zeigten die höchste Affinität zu den Mt-Rezeptoren (pA\(_2\)-Werte: 8.72-8.80; pKrWerte: 8.8-9.1), eine deutlich geringere Affinität zu den M4- und M3-Rezeptoren und die niedrigste Affinität zu den kardialen M2-Rezeptoren (pA\(_2\)-Werte: 7.57-7.79; pKi-Werte: 7.7-7.8). Das Affinitätsprofil (Ml > M4 > M3 > M2) von Biperiden, Sila-biperiden und endo-Sila-biperiden ist dem des Mt-selektiven Antimuscarinicums Pirenzepin qualitativ sehr ähnlich. Die antimuscarinischen Eigenschaften der C/Si-Analoga Biperiden und Sila-biperiden sind nahezu identisch.
KW - Anorganische Chemie
KW - Silicon
KW - Silanol
KW - Sila-biperiden
KW - Bioorganosilicon chemistry
KW - Muscarinic antagonist
KW - Muscarinic receptor subtype
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64303
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Wagner, S. A.
A1 - Sperlich, J.
T1 - Synthese von (-)-(Acetoxymethyl)(hydroxy-methyl)methyl(phenyl)german [(-)-MePhGe(CH\(_2\)OAc)(CH\(_2\)OH)] durch eine Esterase-katalysierte Umesterung: Die erste enzymatische Synthese eines optisch aktiven Germans
N2 - No abstract available.
KW - Anorganische Chemie
KW - Germane
KW - optically active
KW - Biotransformation
KW - stereoselective Transesterification
KW - enzymatic
KW - Porcine liver esterase
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64310
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Sperlich, J.
A1 - Becker, B.
T1 - Bis[2,3-naphthalenediolato(2-)](pyrrolidinio-methyl)germanate-tetartoacetonitrile, the first zwitterionic \(\lambda_5\)-germanate: synthesis and crystal structure analysis
N2 - The zwitterionic spirocyclic \(\lambda_5\)-germanate bis(2,3-naphthalenediolato( 2-)](pyrrolidiniomethyl)germanate (8) was synthesized and the crystal structure of its tetartoacetonitrile solvate 8 · 1/4 CH\(_3\)CN studied by single-crystal X-ray diffraction. Compound 8 was prepared by reaction of (MeO)\(_3\)GeCH\(_2\)NC\(_4\)H\(_8\) (11; NC\(_4\)H\(_8\) = pyrrolidino) with two equivalents of 2,3-naphthalenediol (isolated as 8 · 1/4 CH\(_3\)CN; yield 92%). The coordination polyhedron around the pentacoordi- naphthalenediolatonate germanium atom of 8 · 1/4 CH\(_3\)CN can be described as a strongly distorted trigonal bipyramid (the structure is displaced by 38.9% from the ideal trigonal bipyrarnid towards the ideal square pyramid), the carbon atom occupying an equatorial position. In the crystal lattice of 8 · 1/4 CH\(_3\)CN, the zwitterions form intermolecular N-H ... o hydrogen bonds leading to the formation of dimers. 1H- and \(^{13}\C-NMR studies revealed that 8 also exists in solution ([D\(_6\)]DMSO).
KW - Anorganische Chemie
KW - Lambda5-Germanate
KW - zwitterionic
KW - Germanium
KW - pentacoordinate
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64329
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Lopez-Mras, A.
A1 - Jones, P. G.
T1 - Syntheses, crystal structure analyses, and NMR studies of [2-(dimethylammonio)phenyl]bis[glycolato(2-)-O1,O2]silicate and related zwitterionic spirocyclic \(\lambda_5\)Si-silicates
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64339
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Mühleisen, M.
A1 - Jones, P. G.
T1 - Das erste zwitterionische, optisch aktive Disilicat mit pentakoordiniertem Silicium
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64343
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Mühleisen, M.
A1 - Jones, P. G.
T1 - The first zwitterionic, optically active disilicate with pentacoordinate silicon
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64358
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Mühleisen, M.
T1 - Hexakoordiniertes Silicium in einer molekularen Verbindung mit einer F\(_5\)SiC-Einheit
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64365
ER -
TY - JOUR
A1 - Tacke, Reinhold
A1 - Mühleisen, M.
T1 - Hexacoordinate silicon in a compound with an F\(_5\)SiC unit
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64378
ER -
TY - JOUR
A1 - Suter, H. U.
A1 - Pleß, V.
A1 - Ernzerhof, M.
A1 - Engels, Bernd
T1 - Difficulties in the Calculation of Electron Spin Resonance Parameters using Density Functional Methods
N2 - Density functional theory is applied to the calculation ofthe isotropic byperfine coupJing constants in some small molecules. Various functionals are tested. The agreement of the calculated values to experimental data and values obtained from sophisticated ab initio methods depends on the functionals used and the system under consideration. With respect to spin density calculations the functional of Lee, Yang and Parr with Becke's excbange functional (BLYP) is found to give good results for tbe heavier center of the CH and the NH molecule, while the spin densities of other molecules such as OH, H\(_2\)CN, H\(_2\)CO\(^+\), NO and O\(_2\) deviate considerably from experimental and/or other theoretical results (30%-60%). In cases where the singly occupied orbital can contribute to the isotropic hyperfine coupling constants, accurate results are obtained. The reason fortbis is analyzed.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59113
ER -
TY - JOUR
A1 - Erbelding-Denk, Claudia
A1 - Schroder, Johannes H.
A1 - Schartl, Manfred
A1 - Nanda, Indrajit
A1 - Schmid, Michael
A1 - Epplen, Jörg T.
T1 - Male polymorphism in Limia perugiae (Pisces: Poeciliidae)
N2 - The male-polymorphic poeciliid fish, Limia perugiae, a small teleostean endemic to the southeast of the Caribbean island Hispafiola, consists of three male size morphs with uniform females. Large males differentiate at a size va:rying between 25 and 38 mm; intermediate males, between 21 and 25 mm. Under competition, !arge males exhibit an elaborate courtship display, whereas small males show only a sneak-chase behavior. Intermediate males adapt their tactics to the respective competitors. However, all malemorphs can switch from courtship display to sneak-chase behavior. In large mating groups with four males of different size and five or six virgin females, large dominant a-males as weil as small subordinate \(\delta\)-males did not produce any offspring. Unexpectedly, all progeny were sired exclusively by the intemediate subordinate ß- and \(\gamma\)-males. Breeding experiments with the three male morphs can best be explained by a model of Y -linked genes for small and !arge size which are both suspended by the activity of an autosomal recessive repressor responsible for the development of intermediate males. The dominant allele of the recessive repressor, in either its homoorits heterozygous state, activates the Y-chromosomal genes for !arge or small size, respectively. Accordingly, intermediate males may produce male offspring of all size classes, depending on the presence of either the Y-linked gene or the autosomal repressor.
KW - Physiologische Chemie
KW - Poeciliid fish
KW - male size polymorphism
KW - reproductive success
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61573
ER -
TY - JOUR
A1 - Nakayama, Ichiro
A1 - Foresti, Fausto
A1 - Tewari, Rita
A1 - Schartl, Manfred
A1 - Chourrout, Daniel
T1 - Sex chromosome polymorphism and heterogametic males revealed by two cloned DNA probes in the ZW/ZZ fish Leporinus elongatus
N2 - In order to study the divergence of teleost sex chromosomes, subtractive cloning was carried out between genomic DNA ofmales and females ofthe rainbow trout (XX/XY) and of Leporinus elongatus (ZW /ZZ). Inserts cloned in a plasmid vector were individually tested on Southern blots of DNA of males and females for sex specificity. No sex-specific insert was obtained from trout, but two out of ten inserts cloned from L. elongatus showed sex-specific patterns in this species: one corresponds to a sequence present on both Z and W chromosomes, while the other is W specific. Sequences of these two inserts show neither clear homology with other known sequences, nor an open reading frame. They cross-hybridize with the genomic DNA of Leporinusfriderici, but without sex-specific patterns. Twenty-four L. elongatus adults were sexed by gonadal observation, chromosomed examination and Southern hybridization with one or the other insert. Ten males and 11 females had chromosomes and hybridization patterns typical of their sex. One ZW female was recognized as a male with the W-specific probe. This was also the case for two unusual ZW males, one having a male hybridization pattern with the other probe. These three atypical individuals may result from single genetic exchanges between four regions of the Z and the W, giving rise to three atypical W chromosomes. Finding males with such atypical heterochromosomes in a female heterogametic species may indicate that a gradual transition occurs between the heterogametic systems.
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61583
ER -
TY - JOUR
A1 - Shephard, S. E.
A1 - Lutz, Werner K.
A1 - Schlatter, C.
T1 - The lacI transgenic mouse mutagenicity assay: quantitative evaluation in comparison to tests for carcinogenicity and cytogenetic damage in vivo
N2 - The detection Iimit of the lacl transgenic mouse mutagenicity assay lies, in practice, at approximately a 50-100% increase in mutant frequency in treated animals over controls. The sensitivity of this assay in detecting genotoxins can be markedly improved by subchronic rather than acute application of the test compound. The lac/ transgenic mouse mutagenicity assay was compared quantitatively to rodent carcinogenicity tests and to presently used in vivo mutagenicity assays. With the genotoxic carcinogens tested thus far, a rough correlation between mutagenic potency and carcinogenic potency was observed: on average, to obtain a doubling in lacl mutant frequency the mice bad to be treated with a total dose equal to 50 times the TD50 daily dose Ievel. This total dose could be administered eilher at a high dose rate within a few days or, preferably, at a low dose rate over several weeks. This analysis also indicated that a lacl experiment using a 250-day exposure period would give a detection Iimit approximately equal to that of a long-term carcinogenicity study. In comparison to the micronucleus test or the chromosome aberration assay, acute sturlies with the presently available lacl system offered no increase in sensitivity. However, subchronic lacl sturlies (3-4-month exposure) resulted in an increase in sensitivity over the established tests by 1-2 orders of magnitude (shown with 2-acetylaminofluorene, N-nitrosomethylamine, N-nitrosomethylurea and urethane). 1t is concluded that a positive result in the lacl test can be highly predictive of carcinogenicity butthat a negative result does not provide a large margin of safety.
KW - Toxikologie
KW - Transgenie mice
KW - Mutagenicity assay
KW - Sensitivity
KW - Chromosome aberration
KW - Micronucleus test
KW - Carcinogenic potency
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60638
ER -
TY - JOUR
A1 - Mühlhäuser, M.
A1 - Froudakis, G.
A1 - Zdetsis, A.
A1 - Engels, Bernd
A1 - Flytzanis, N.
A1 - Peyerimhoff, S. D.
T1 - Ab initio investigation of the stability of Si\(_3\)C<\(_3\) clusters and their structural and bonding features
N2 - Various structural possibilities for Si\(_3\)C\(_3\) clusters are investigated by ab initio calculations employing basis sets of double- and triple-zeta quality augmented by d polarization functions. Correlation effects are included by a second-order Moeller Piesset perturbation treatment. For the two lowest-lying structures higher-order correlation corrections and multi-reference effects are also included. Bonding features are investigated by two different types of population analyses to obtain insight into the nature of chemical bonding. A total of 17 stationary points were investigated, 14 of which correspond to local minima and three being transition states. The energetically lowest-lying structures are: A "pyramidlike" structure with various multicenter bonds, followed by a es symmetric isomer closely related to the ground state Si6 structure. Planar structures, favoured in small carbon clusters, lie higher in energy and are transition states. The lowest-lying triplet system is found to be the linear nonsymmetric Si - C-C-C-Si -Si structure, which is calculated to lie about 38 kcalfmole above the singlet ground state. A building-up principle based on bonding criteria is suggested for the occurence of the various structural possibilities.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59060
ER -
TY - JOUR
A1 - Wortmann-Saleh, D.
A1 - Engels, Bernd
A1 - Peyerimhoff, S. D.
T1 - Theoretical Study of the Reaction O(\(^3\)P) + C\(_2\)H\(_4\) and comparison with the \(^3\)CH\(_3\) + C\(_2\)H\(_4\) Reaction
N2 - The minimum energy path for the reaction O(\(^3\)P\(_g\)) + C\(_2\)H\(_4\)(\(^1\)A\(_g\)) has been calculated by optimizing all relevant geometrical parameters along the approach of oxygen to ethene. A barrier of 4.7 kcal/mol in the \(^3\)A"( ... 9a'\(^2\)- 10a'3a") potential energy surface and an energy difference of 14.4 kcal/mol between the product and the fragments is found at the multireference-configuration interaction level. The corresponding values at the lower-level treatment CASSCF are 9 kcal/mol for the barrier and 9 kcal/mol for the depth of the potential; this shows the importance of inclusion of electron correlation. The barrier for CH\(_2\) rotation for the lowestenergy structure (asymmetric OC\(_2\)H\(_4\)) is around 5 kcal/mol. The energy gap to the first excited state \(^3\)A'( ... 9a'l0a'3a'12) is found tobe 3.6 kcal/mol in MRD-CI calculations at the ground-state minimum. Comparison with \(^3\)CH\(_2\) + C\(_2\)H\(_4\) shows that in this system the lowest-energy surface is \(^3\)A', i.e., the state which is the excited state in 0 + C\(_2\)H\(_4\). This difference in energy ordering of \(^3\)A' and \(^3\)A" states results from the fact that the p\(_x\), p\(_y\), p\(_z\) degeneracy of oxygen orbitals is lifted in \(^3\)CH\(_2\)leading to b\(_1\), b\(_2\). and a\(_1\) MOs whereby the lowest b\(_2\) (a") remains doubly occupied; as a consequence, the reaction pattem between the oxygen and \(^3\)CH\(_2\) approach is different, which is also quite apparent in the calculated charge transfer.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59076
ER -
TY - JOUR
A1 - Staikova, M.
A1 - Peric, M.
A1 - Engels, Bernd
A1 - Peyerimhoff, S. D.
T1 - Ab initio Investigation of the Structure of the X\(^2\)A', A\(^2\)A'' (1\(^2\)Π) Spectral System of HCO: Investigation of the Magnetic Hyperfine Effects
N2 - Results ofan ab initio study ofthe hyperfine structure of the X\(^2\)A', A\(^2\) A" ( 1\(^2 \Pi\)) system ofthe formyl radical are presented. Special attention is paid to the analysis of the interplay between the vibronic and magnetic hyperfine etfects. The results of computations are in very good agreement with the available experimental findings. The values for the hyperfine coupling constants in lower bending Ievels of both electronic species are predicted.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59089
ER -
TY - JOUR
A1 - Froudakis, G.
A1 - Zdetsis, A.
A1 - Mühlhäuser, M.
A1 - Engels, Bernd
A1 - Peyerimhoff, S. D.
T1 - A comparative ab initio study of the Si\(_2\)C\(_4\), Si\(_3\)C\(_3\), Si\(_4\)C\(_2\) clusters
N2 - Various structural possibilities for the Si\(_2\)C\(_4\) and Si\(_4\)C\(_2\) clusters are investigated by employing a basis set of triple-zeta plus polarization quality; electron correlation is generally accounted for by second-order M0ller-Plesset and, in certain instances, by higher-order perturbation (CASPT2) approaches. The building-up principle recently suggested from an analysis of Si\(_3\)C\(_3\) clusters is found to be fully operative for Si\(_2\)C\(_4\) and Si\(_4\)C\(_2\) clusters. A comparison of the structure and stability of various geometrical arrangements in the series C\(_6\) , Si\(_2\)C\(_4\) , Si\(_3\)C\(_3\) , Si\(_4\)C\(_2\), and Si\(_6\) shows that linear and planar structures become rapidly less stable if carbons are replaced by silicons and that the three-dimensional bipyramidal forms become less favorable as soon as silicons are exchanged by carbons in the parent Si\(_6\) structure. The effects can be rationalized in qualitative terms based on differences in silicon and carbon bonding.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59097
ER -
TY - JOUR
A1 - Suter, H. U.
A1 - Huang, M.-B.
A1 - Engels, Bernd
T1 - A Multireference Configuration Interaction Study of the Hyperfine Structure of the Molecules CCO, CNN and NCN in their triplet ground states
N2 - The hyperfine structures of the isoelectronic molecules CCO. CNN, and NCN in their triplet ground states (X\(^3 \sum ^-\)) are investigated by means of ab initio methods. The infrared frequencies and geometries are detennined and compared with experiment. Configuration selected multireference configuration interaction calculations in combination with perturbation theory to correct the wave function (MRD-CI/B\(_K\)) employing extended atomic orbital (AO) basis sets yielded very accurate hyperfine properties. The theoretical values for CCO are in excellent agreement with the experimental values determined by Smith and Weltner [J. Chem. Phys. 62,4592 (1975)]. For CNN, the first assignment of Smith and Weltner for the two nitrogen atoms has to be changed. A qualitative discussion of the electronic structure discloses no simple relation between the structure of the singly occupied orbitals and the measured hyperfine coupling constants. Vibrational effects were found to be of little importance.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59108
ER -
TY - JOUR
A1 - Staikova, M.
A1 - Engels, Bernd
A1 - Peric, M.
T1 - Ab initio investigation of the hyperfine structure in the 1\(^2\)Π\(_u\)(X\(^2\)A\(_1\), A\(^2\)B\(_1\) system of BH\(_2\))
N2 - No abstract available
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59000
ER -
TY - JOUR
A1 - Engels, Bernd
T1 - Detailed study of the configuration selected multi-reference configuration interaction method combined with perturbation theory to correct the wave function
N2 - A reliable prediction of the isotropic hyperfine coupling constant A\(_{iso}\) is still a difficult task for ab initio calculations. In previous studies, the configuration selected multireference configuration interaction method in combination with perturbation theory to correct the wave function (MRCI/ B\(_K\)) yielded accurate isotropic hyperfine coupling constants very economically. The present study gives a detailed analysis of the MRCI/ B\(_K\) method based on the X\(^2 \pi\) state of CH as a test case. Furthermore, a comparison to various other methods such as Maller-Ptesset perturbation theory and the coupled cluster approach is made. The success of the MRCI/ B\(_K\) method in predicting isotropic hyperfine coupling constants is explained in terms of the inßuence of higher than double excitations.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59019
ER -
TY - JOUR
A1 - Suter, H. U.
A1 - Engels, Bernd
T1 - Theoretical investigation of ESR parameters: H\(_2\)CN and H\(_2\)CO\(^+\)
N2 - The hyperfine structure of the two isoelectronic molecules H\(_2\)CN and H\(_2\)CO\(^+\) in their electronic ground state (X\(^2\)B\(_2\)) is studied. The influence of the atomic orbital (AO), basis sets, of the correlation treatment, and of the. equilibrium geometry on the obtained hyperfine propertles 1s - investigated. It is found that the multireference double excitation-configuration interaction (MRD-CI)/ BK treatment in which an MRD-CI wave function is corrected by a modified B\(_K\) method yields equivalent results to quadratic CI [QCISD(T)], coupled cluster single doubles [CCSD(T)), or Brueckner doubled [BD(T)]. Uncertainties in the equilibrium geometries are found to be the major source for discrepancies between theoretically and experimentally determined isotropic hyperfine coupling constants (hfccs). For the heavier centers, the calculated values of the isotropic hfccs agrees nearly perfectly with experimental values (\(\approx\) 1%-2%). The calculated values for the hydrogens are too low, but using the equilibrium structure suggested by Yamamoto and Sato [J. Chem. Phys. 96, 4157 ( 1992)], the best estimate deviates by less than 3%.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59029
ER -
TY - JOUR
A1 - Mühlhäuser, M.
A1 - Engels, Bernd
A1 - Marian, C. M.
A1 - Peyerimhoff, S. D.
A1 - Bruna, P. J.
A1 - Jansen, M.
T1 - Einfluß der Ladungsverteilung auf die Bindungslängen im P\(_4\)O\(_6\) Gerüst bei Verbindungen des Typs P\(_4\)O\(_6\)X
N2 - No abstract available
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59034
ER -
TY - JOUR
A1 - Huang, M.-B.
A1 - Suter, H. U.
A1 - Engels, Bernd
T1 - Theoretical Study of the Dimethylamino Radical (CH\(_3\))\(_2\)N and its protonated cation (CH\(_3\))\(_2\)NH\(^+\)
N2 - In the present work the dimethylamino radical ( ( CH\(_3\)) \(_2\)N) and its protonated cation ( ( CH\(_3\))\(_2\)NH\(^+\)) are investigated by means of ab initio methods. The geometries of various conformations of both compounds are obtained with UMP2/6·31 G** calculations, while the hyperfine structure and its dependence on the geometry is studied using the MRD-Cl/B\(_K\) method. The two molecules are compared to study the inftuence of the protonation on geometry and hyperfine structure. The effects of the rotational barriers on the hyperfine structures of (CH\(_3\))\(_2\)N, (CH\(_3\)CH\(_2\))\(_2\)N and ( (CH\(_3\))\(_2\)CH)\(_2\)N will be discussed.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59047
ER -
TY - JOUR
A1 - Pleß, V.
A1 - Suter, H. U.
A1 - Engels, Bernd
T1 - Ab initio study of the energy difference between the benzene and the cumulene form of the C\(_6\) molecule
N2 - The energy difference between the three lowest-lying isomers of C\(_6\) the linear \(^3 \sum ^-\) state and the two ring forms,the benzene structure (\(^1\)A\(_{18}\)) possessing D\(_{6h}\) symmetry and a distorted cyclic form ( \(^1\)A'\(_1\), D\(_{3h}\) symmetry) have been calculated using various ab initio methods. Variational methods such as multireference configuration interaction (MR-CI) and complete active space second order perturbatiOn treatment (CASPT2) have been applied, as weil as perturbational treatments and coupled cluster calculations (CCD). The correlation of all valence shell electrons is found to be important for a balanced description of the isomers of C\(_6\) . Methods which do not account for higher-order effects appropriately proved to be unsuitable for calculating the energy difference correctly. The results from multireference configuration interaction methods show that the isomers are close in energy with the cyclic forms somewhat lower than the linear form. The ring form possessing D\(_{3h}\) symmetry (\(^1\)A'\(_1\)} is found tobe the lowest-lying structure.
KW - Organische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59059
ER -
TY - JOUR
A1 - Götz, Rudolf
A1 - Köster, Reinhard
A1 - Winkler, Christoph
A1 - Raulf, Friedrich
A1 - Lottspeich, Friedrich
A1 - Schartl, Manfred
A1 - Thoenen, Hans
T1 - Neurotrophin-6 is a new member of the nerve growth factor family
N2 - DURING vertebrale development, many neurons depend for survival and differentiation on their target cells\(^{1-3}\). The best documented mediator of such a retrograde trophic action is the neurotrophin nerve growth factor (NGF)\(^1\). NGF and the other known members of tbe neurotrophin family, brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT -3) and neurotrophin-4/5 (NT -4/5) are conserved as distinct genes over large evolutionary distances\(^{4 -6}\). Here we report the cloning of neurotrophin-6 (NT -6), a new member of this family from the teleost fish Xiphophorus. NT -6 distinguishes itself from the other known neurotrophins in that it is not found as a soluble protein in the medium of producing cells. The addition of heparin (but not chondroitin) effects the release of NT -6 from cell surface and extracellular matrix molecules. Recombinant purified NT -6 has a spectrum of actions similar to NGF on chick sympathetic and sensory neurons, albeit with a lower potency. NT -6 is expressed in tbe embryonie valvulla cerebelli; expression persists in some adult tissues. The interaction of NT-6 with heparin-binding molecuJes may modulate its action in the nervous system .
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61544
ER -
TY - JOUR
A1 - Malitschek, Barbara
A1 - Wittbrodt, Joachim
A1 - Fischer, Petra
A1 - Lammers, Reiner
A1 - Ullrich, Axel
A1 - Schartl, Manfred
T1 - Autocrine stimulation of the Xmrk receptor tyrosine kinase in Xiphophorus melanoma cells and identification of a source for the physiological ligand
N2 - The melanoma·inducing gene of Xiphophorus fish encodes the Xmrk receptor tyrosine kinase. U sing a highly specific antiserum p~oduced against the recombinant receptor expressed with a baculovirus, it is shown that Xmrk is the most abundant phosphotyrosine protein in fish melanoma and thus highly activated in the tumors. Studies on a melanoma cellline revealed that these cells produce an activity that considerably stimulates receptor autophosphorylation. The stimulating activity induces receptor down-regulation and can be depleted from the melanoma cellsupernatant by the immobilized recombinant receptor protein. The fish melanoma cells can thus be considered autocrine tumor cells providing a source for future purification and characterization of the Xmrk ligand.
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61551
ER -
TY - JOUR
A1 - Meyer, Axel
A1 - Morrissey, Jean M.
A1 - Schartl, Manfred
T1 - Recurrent origin of a sexually selected trait in Xiphophorus fishes inferred from a molecular phylogeny
N2 - DARWIN\(^1\) believed that sexual selection accounts for the evolution of exaggerated male ornaments, such as the sword-like caudal fin extensions of male fishes of the genus Xiphophorus, that appear detrimental to survival. Swordtails continue to feature prominently in empirical work and theories of sexual selection; the pre-existing bias hypothesis has been offered as an explanation for the evolution of swords in these fishes\(^{2,3}\). Based upon a largely morphological phylogeny, this hypothesis suggests that female preference to mate with sworded males arose in ancestrally swordless species, thus pre-dating the origin of the sword itself and directly driving its evolution. Here we present a molecular phylogeny (based on mitochondrial and nuclear DNA sequences) of Xiphophorus which differs from the traditional one: it indicates that the sword originated and was lost repeatedly. Our phylogeny suggests that the ancestor of the genus is more likely to have possessed a sword than not, thus questioning the applicability of the pre-existing bias hypothesis as an explanation for the cvolution of this sexually selected trait.
KW - Physiologische Chemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61569
ER -
TY - JOUR
A1 - Lampidis, Robert
A1 - Gross, Roy
A1 - Sokolovic, Zeljka
A1 - Goebel, Werner
A1 - Kreft, Jürgen
T1 - The virulence regulator protein of Listeria ivanovii is highly homologous to PrfA from Listeria monocytogenes and both belong to the Crp-Fnr family of transcription regulators
N2 - No abstract available
KW - Biologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60503
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Gerstner, E.
A1 - Kemmer, R.
A1 - Llewellyn, G.
A1 - Bentley, T. W.
T1 - Elektrophile Additionen an das Bicyclo[1.1.0]butan-System von 1-Phenyl- und 1-(4-Anisyl)tricyclo[4.1.0.0\(^{2,7}\)]heptan: Säure-katalysierte Reaktionen mit Wasser und Methanol, Anlagerung von Essigsäure und Oxymercurierung
N2 - No abstract available
KW - Organische Chemie
KW - 6-Norpinanols
KW - 6-aryl-
KW - preparation
KW - 6-Norpinyl 3
KW - 5-dinitrobenzoates
KW - hydrolysis
KW - Carbocations
KW - generation and rearrangement
KW - 2-Norcaranols
KW - 1-aryl-
KW - Cyclohept-3-en-1-ols
KW - 3-aryl-
KW - conformation
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58696
ER -
TY - JOUR
A1 - Gerstner, E.
A1 - Kemmer, R.
A1 - Christl, Manfred
T1 - Elektrophile Additionen an das Bicyclo[1.1.0]butan-System von Tricyclo[4.1.0.0\(^{2,7}\)]-heptan-Derivaten: Halogen-Elektrophile
T1 - Electrophilic Additions to the Bicyclo[l.l.O)butane System of Tricyclo[4.1.0.0\(^{2,7}\)]heptane Derivatives: Halogen Electrophiles
N2 - No abstract available
KW - Organische Chemie
KW - Norpinanes
KW - preparation
KW - Carbocations
KW - classical and nonclassical
KW - Neighbouring group participation
KW - Halonium ions
KW - Migratory aptitudes in carbocations
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58700
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Braun, Martin
A1 - Wolz, E.
A1 - Wagner, W.
T1 - Cycloallene, 9 - 1-Phenyl-1-aza-3,4-cyclohexadien, das erste Isodihydropyridin: Erzeugung und Abfangreaktionen
T1 - Cycloallenes, 9 - 1-Phenyl-1-aza-3,4-cyclohexadiene, the First Isodihydropyridine: Generation and Interception
N2 - No abstract available
KW - Organische Chemie
KW - Isoquinolines
KW - hexahydro-
KW - Cyclobuta[c}pyridines
KW - hexahydro-
KW - Cycloadditions
KW - [2 + 2]- and [4 + 2]-
KW - 3-Azabicyclo{3
KW - 1
KW - 0]hexane
KW - 6
KW - 6-dibromo-3-phenyl-
KW - 2
KW - 4-Pentadienylamine
KW - 3-n-butyl-N-phenyl-
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58714
ER -
TY - JOUR
A1 - Strik, Werner K.
A1 - Dierks, Thomas
A1 - Franzek, Ernst
A1 - Stöber, Gerald
A1 - Maurer, Konrad
T1 - P300 in Schizophrenia: Interactions between Amplitudes and Topography
N2 - Low P300 amplitudes and topographical asymmetries have been reponed in schizophrenic patients, but reference-independent amplitude assessment failed to replicate reduced amplitudes. P300 amplitude is conventially assessed at midline electrodes (PZ), anti asymmetric topography as reported in schizophrenics, may conj'ound this measurement. We lnvestigated the possible Interaction between P300 ropography and assessments of amplitudes. ln 41 clinically stable schizophrenics and 31 normal controls, the generalfinding ofreduced amplitudes at the P'l electrode and topographical asymmetrles in the patient group were replicated. ln both groups, a.symmetries of the P300 field (lateralized peaks) reduced the standard amplitude assessment at the midline parletal electrode, but did not Qjfoct the reference-independent, global amplitude assessment. This shows thal asymmetry per se does not imply reduced field strength. in addition, in schizophreraics. but not in controls, there was a significcmt effect oftlae direction of asymmetry on both amplltude measures, amplitudes belng lower with increasing shift ofthe P300 peak to the right side. Considering also the slightly left-lateralized peaks in the normal controls. this suggests rhat only right lateralized P300 peaks upressfunctional deficits in schizophrenics, whereas left lateralized pealcs fall wlthin the physiological variability of the P3OO field. Tht refonnce-independent amplitude assessment is proposed for unambiguous amplitude assessment in order to better define the clinical, psychological and physiopathological mtaning of the P3OO alterations in schizophrenics.
KW - Schizophrenie
KW - Event-related potentials
KW - P300
KW - P300 topography
KW - Brain mappins
KW - Schizophrenia
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63351
ER -
TY - JOUR
A1 - Lesch, K. P.
A1 - Stöber, Gerald
A1 - Balling, U.
A1 - Franzek, Ernst
A1 - Li, S. H.
A1 - Ross, C. A.
A1 - Newman, M.
A1 - Beckmann, H.
A1 - Riederer, P.
T1 - Triplet repeats in clinical subtypes of schizophrenia: variation at the DRPLA (B37 CAG repeat) locus is not associated with periodic catatonia
N2 - Clinical evidence for a dominant mode of inheritance and anticipation in periodic catatonia, a distinct subtype of schizophrenia, indicates that genes with triplet repeat expansions or other unstable repetitive elements affecting gene expression may be involved in the etiology of this disorder. Because patients affected with dentatorubral-pallidoluysian atrophy (DRPLA) may present with "schizophrenic" symptoms, we have investigated the DRPLA (B 37 CAG repeat) locus on chromosome 12 in 41 patients with periodic catatonia. The B 37 CAG repeat locus was highly polymorphic but all alleles in both the patient and control group had repeat sizes within the normal range. We conclude that variation at the DRPLA locus is unlikely to be associated with periodic catatonia. The evidence for dominant inheritance and anticipation as well as the high prevalence of human brain genes containing trinucleotide repeats justifies further screening for triplet repeat expansions in periodic catatonia.
KW - Schizophrenie
KW - Association study
KW - B 37 CAG repeat locus
KW - chromosome 12
KW - schizophrenia
KW - periodic catatonia
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63369
ER -
TY - JOUR
A1 - Strik, Werner K.
A1 - Dierks, Thomas
A1 - Franzek, Ernst
A1 - Stöber, Gerald
A1 - Maurer, Konrad
T1 - P 300 asymmetries in schizophrenia revisited with reference-independent methods
N2 - Evidence of hemispheric asymmetries in schizophrenia has been reported from different research areas. Asymmetries in evoked potential P300 topography are still controversial because of inconsistent findings. In the present study. previous results of abnormal lateralization of P300 were replicated in stabilized residual Schizophrenie patients. Auditory P300 was recorded during an odd ball task in which subjeets detected rare target stimuli. Schizophrenie patients had the P300 peak shifted to the right hemisphere and differed signifieantly from age- and sex-matched normal control subjects who had left-lateralized P300 peaks. A comparison of different methods of assessment and analysis of the topographical features of the P300 electric fields showed that the extraction of reference-independent descriptors of P300 topography is a reliable and sensitive method for statistical handling of the maps. The results suggest left hemispheric dysfunction during cognitive tasks in a subgroup of Schizophrenie patients. Inconsistencies between previous sturlies are likely to be due to heterogeneous patient groups, which may have included patients in an acute Schizophrenie episode or patients in clinical remission. lnvestigation of the clinical meaning of P300 alterations requires careful psychopathological definition of the patient groups.
KW - Schizophrenie
KW - Laterality
KW - evoked potentials
KW - electroeneephalography
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63372
ER -
TY - JOUR
A1 - Siwka, Wieslaw
A1 - Schwinn, Andreas
A1 - Baczko, Knut
A1 - Pardowitz, Iancu
A1 - Mhalu, Fred
A1 - Shao, John
A1 - Rethwilm, Axel
A1 - ter Meulen, Volker
T1 - vpu and env sequence variability of HIV-1 isolates from Tanzania
N2 - No abstract available
KW - Virologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61355
ER -
TY - JOUR
A1 - Hahn, Heidi
A1 - Baunach, Gerald
A1 - Bräutigam, Sandra
A1 - Mergia, Ayalew
A1 - Neumann-Haefelin, Dieter
A1 - Daniel, Muthiah D.
A1 - McClure, Myra O.
A1 - Rethwilm, Axel
T1 - Reactivity of primate sera to foamy virus Gag and Bet proteins
N2 - In order to establish criteria for the Serodiagnosis of foamy virus infections we investigated the extent to which sera from iofected individuals of human and primate origin react with structural and non-structural virus proteins in immunoblot assays. Using lysates from infected cells as the source of virus antigen, antibodies were preferentially detected against the Gag proteins and the non-structural Bet protein. Both the Gag precursor molecules of 70 and 74K apparent M\(_r\) and the cytoplasmic 60K M\(_r\) Bet protein were found to be phosphorylated, the latter being synthesized in large amounts in infected cells. Rahbit antiserum raised against recombinant human foamy virus (HFV) Gag major capsid protein cross-reacted with foamy viruses of chimpanzee, gorilla, orang-utan, rhesus monkey and Mrican green monkey origin. This was reßected by a broad cross-reactivity of the respective monkey sera to the Gag proteins of the various foamy virus isolates. Cross-reactivity of antisera against the Bet protein was restricted to viruses from man and the great apes. Recombinant Gag and Bet proteins expressed in prokaryotes or in insect cells were readily recognized by foamy virus-positive primate sera. Screening serum samples from chimpanzees with HFV Gag and Bet proteins expressed by recombinant baculoviruses revealed that 18 out of 35 (52%) were positive for Gag antibodies. Of these, 13 (72 o/o) showed antiborlies against the Bet protein, indicating that Bet antigen is of value in sero1ogical screening for foamy virus infections.
KW - Virologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61366
ER -
TY - JOUR
A1 - Schliephake, Andreas W.
A1 - Rethwilm, Axel
T1 - Nuclear Localization of Foamy Virus Gag Precursor Protein
N2 - All foamy viruses give rise to a strong nuclear staining when infected cells are reacted with sera from infected hosts. This nuclear ftuorescence distinguishes foamy viruses from all other retroviruses. The experiments reported here indicate that the foamy virus Gag precursor protein is transiently located in the nuclei of infected cells and this is the likely reason for the typical foamy virus nuclear fluorescence. By using the vaccinia virus expression system, a conserved basic sequence motif in the nucleocapsid domain of foamy virus Cag proteins was identified to be responsible for the nuclear transport of the gag precursor molecule. Tbis motif was also found to be able to direct a heterologous protein, the Gag protein of human immunodeficiency virus, into the nucleus.
KW - Virologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61371
ER -
TY - JOUR
A1 - Gründemann, Dirk
A1 - Gorboulev, Valentin
A1 - Gambaryan, Stepan
A1 - Veyhl, Maike
A1 - Koepsell, Hermann
T1 - Drug excretion mediated by a new prototype of polyspecific transporter
N2 - CATIO~IC drugs of different types and structures (antihistaminics, antiarrhythmics, sedatives, opiates, cytostatics and antibiotics, for example) are excreted in mammals by epithelial cells of the renal proximal tubules and by hepatocytes in the liver1-4. In the proximal tubules, two functionally disparate transport systems are involved which are localized in the basolateral and luminal plasma membrane and are different from the previously identified neuronal monoamine transporters and A TP-dependent multidrug exporting proteins1-3,5-12. Here we report the isolation of a complementary DNA from rat kidney that encodes a 556-amino-acid membrane protein, OCT1, which has the functional characteristics of organic cation uptake over the basolateral membrane of renal proximal tubules and of organic cation uptake into hepatocytes. OCTl is not homologous to any other known protein and is found in kidney, liver and intestine. As OCTl translocates hydrophobic and hydrophilic organic cations of different structures, it is considered to be a new prolotype of polyspecific transporters that are important for drug elimination.
KW - Biologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59327
ER -