@misc{DandekarArgos1991, author = {Dandekar, Thomas and Argos, Patrick}, title = {Chaperonin-mediated protein folding at the surface of groEL through a "molten globule" intermediate}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29939}, year = {1991}, abstract = {No abstract available}, language = {en} } @article{StoeckliLililienNaeherNoeetal.1991, author = {St{\"o}ckli, K. A. and Lililien, L. E. and N{\"a}her- No{\´e}, M. and Breitfeld, G. and Hughes, Richard A. and Raff, M. C. and Thoenen, Hans and Sendtner, Michael}, title = {Regional distribution, developmental changes, and cellular localization of CNTF-mRNA and protein in the rat brain}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31172}, year = {1991}, abstract = {Ciliary neurotrophic factor (CNTF) is a potent survival molecule for a variety of embryonic neurons in culture. The developmental expression of CNTF occurs clearly after the time period of the physiological cell death of CNTF-responsive neurons. This, together with the sites of expression, excludes CNTF as a target-derived neuronal survival factor, at least in rodents. However, CNTF also participates in the induction of type 2 astrocyte differentiation in vitro. Here we demonstrate that the time course of the expression of CNTF-mRNA and protein in the rat optic nerve (as evaluated by quantitative Northern blot analysis and biological activity, respectively) is compatible with such a glial differentiation function of CNTF in vivo. We also show that the type 2 astrocyte-inducing- activity previously demonstrated in optic nerve extract can be precipitated by an antiserum against CNTF. Immunohistochemical analysis of astrocytes in vitro and in vivo demonstrates that the expression of CNTF is confined to a subpopulation of type 1 astrocytes. The olfactory bulb of adult rats has comparably high levels of CNTF to the optic nerve, and here again, CNTF-immunoreactivity is localized in a subpopulation of astrocytes. However, the postnatal expression of CNTF in the olfactory bulb occurs later than in the optic nerve. In other brain regions both CNTF-mRNA and protein levels are much lower.}, language = {en} } @article{MaschwitzFialaMoogetal.1991, author = {Maschwitz, Ulrich and Fiala, Brigitte and Moog, J. and Saw, L. G.}, title = {Two new myrmecophytic associations from the Malay Peninsula: ants of the genus Cladomyrma as partners of Saraca thaipingensis and Crypteronia griffithii}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32992}, year = {1991}, abstract = {In Peninsular Malaysia the trees Saraca thaipingensis (Caesalpiniaceae) and Crypteronia griffithii (Crypteroniaceae) are inhabited by ants. In the vicinity ofGombak, near Kuala Lumpur, the hollow internodes of young Saraca thaipingensis plants are colonized mainly by two Cladomyrma species. In larger trees a Crematogaster sp. is also found. Crypteronia griffithii is inhabited by a third species of Cladomyrma. None of these species is conspecific with any of the three Cladomyrma taxa so far described. The colonies are founded by single mated queens, which have a conspicuous, sphecid wasp-like behaviour when searching for host plants and nest sites. They chew holes into the plant intern odes and hollow them out to provide nest sites. Coccids and pseudococcids are cultivated within the internodes. The homopterans are not carried by queens on their nuptial flights. They apparently find their way by themselves into the cavities or are perhaps carried there by the worker ants. The Cladomyrma ants on Crypteronia are not aggressive, in contrast to those on Saraca thaipingensis. The relationship of Crypteronia with ants seems to be obligatory, whereas Saraca was only partly colonized by Cladomyrma. The interaction of Saraca with Crematogaster sp. is loose and facultative, since the Crematogaster sp. also lives on other tree species. Our studies have now revealed four Cladomyrma spp. which are regularly associated with plants. The genus therefore seems to have an entirely myrmecophytic way of life.}, language = {en} } @article{WuBeckerWaagetal.1991, author = {Wu, Y.S. and Becker, Charles R. and Waag, A. and Kraus, M. M. and Bicknell-Tassius, R. N. and Landwehr, G.}, title = {Correlation of the Cd-to-Te ratio on CdTe surfaces with the surface structure}, isbn = {0163-1829}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37789}, year = {1991}, abstract = {We report here that reconstruction on (100), (1lIlA, and (1l1lB CdTe surfaces is either C(2X2), (2X2), and (l X I) or (2X I), (l X I), and (l X I) when they are Cd or Te stabilized, respectively. There is a mixed region between Cd and Te stabilization in which the reflected high-energy electron-diffraction (RHEED) patterns contain characteristics of both Cd- and Te-stabilized surfaces. We have also found that the Cd-to-Te ratio of the x-ray photoelectron intensities of their 3d\(_{3/ 2}\) core levels is about 20\% larger for a Cd-stabilized (1lIlA, (1lIlB, or (100) CdTe surface than for a Te-stabilized one. According to a simple model calculation, which was normalized by means of the photoelectron intensity ratio of a Cd-stabilized (lll)A and aTe-stabilized (1l1lB CdTe surface, the experimental data for CdTe surfaces can be explained by a linear dependence of the photoelectron-intensity ratio on the fraction of Cd in the uppermost monatomic layer. This surface composition can be correlated with the surface structure, i.e., the corresponding RHEED patterns. This correlation can in turn be employed to determine Te and Cd evaporation rates. The Te reevaporation rate is increasingly slower for the Te-stabilized (Ill) A, (l1l)B, and (100) surfaces, while the opposite is true for Cd from Cd-stabilized (Ill) A and (Ill)B surfaces. In addition, Te is much more easily evaporated from all the investigated surfaces than is Cd, if the substrate is kept at normal molecular-beam-epitaxy growth temperatures ranging from 2oo·C to 300 ·C.}, subject = {Festk{\"o}rperphysik}, language = {en} } @article{UlrichsMuellerRuchholtz1991, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, Wolfgang}, title = {Modulation of pancreatic islet allo immunogenicity and immunobiological in vitro and in vivo consequences}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78261}, year = {1991}, abstract = {No abstract available.}, subject = {Immunobiologie}, language = {en} } @article{KrzymanskiWaagaUlrichsetal.1991, author = {Krzymanski, M. and Waaga, A. M. and Ulrichs, Karin and M{\"u}ller-Ruchholtz, Wolfgang}, title = {Long-standing rat kidney graft survival by a combination of organ perfusion with MHC class II monoclonal antibody and immunosuppression with reduced doses of 15-deoxyspergualin.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64442}, year = {1991}, abstract = {No abstract available}, subject = {Niere}, language = {en} } @article{SchluppParzefallSchartl1991, author = {Schlupp, I. and Parzefall, J. and Schartl, Manfred}, title = {Male mate choice in mixed bisexual/-unisexual breeding complexes of Poecilia (Teleostei: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-80309}, year = {1991}, abstract = {The livebearing all-female fish Poecilia formosa reproduces by gynogenesis, a modified form of parthenogenesis. P. formosa forms at least two breeding complexes: in its northern range it exists sympatrically with Poecilia latipinna and in its southern range with Poecilia mexicana. Differences between these complexes and their possible origin are discussed. Embryogenesis is triggered by sperm of males of these closely related sympatric species. Because inheritance is stricdy maternal, from the male point of view energy and time invested are totally lost. In this study we wanted to elucidate whether males are able to distinguish between conspecific and parasitic females. It could be shown that males are able to distinguish females optically, but that this ability was obscured as soon as chemical and/or tactile contact was possible. Furthermore, we found that females in an attractive phase of their sexual cycle are always preferred, regardless of species. This is possibly the mechanism by which parasitic females obtain the matings they need to reproduce.}, subject = {Poecilia (Teleostei: Poeciliidae)}, language = {en} } @article{MalitschekSchartl1991, author = {Malitschek, B. and Schartl, Manfred}, title = {Rapid identification of recombinant baculoviruses using PCR}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-80328}, year = {1991}, abstract = {no abstract available}, subject = {PCR}, language = {en} } @article{LohseKlotzSchwabe1991, author = {Lohse, Martin J. and Klotz, Karl-Norbert and Schwabe, Ulrich}, title = {Mechanism of A2 adenosine receptor activation. I. Blockade of A2 adenosine receptors by photoaffinity labeling}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86073}, year = {1991}, abstract = {It has previously been shown that covalent incorporation of the photoreactive adenosine derivative (R)-2-azido-N6-p-hydroxyphenytisopropyladenosine [(R)-AHPIA] into the A, adenosine receptor of intact fat cells leads to a persistent activation of this receptor, resulting in a reduction of celular cAMP Ieveis [Mol. Pharmacol. 30:403-409 (1986)]. In contrast, covalent incorporation of (R)-AHPIA into human platelet membranes, which contain only stimulatory A2 adenosine receptors, reduces adenytate cyclase Stimulation via these receptors. This effect of (R)-AHPIA is specific for the A2 receptor and can be prevented by the adenosine receptor antagonist theophylline. Binding studies in-dicate that up to 90\% of A2 receptors can be blocked by photoincorporation of (R)-AHPIA. However, the remaining 10-20\% of A2 receptors are sufficient to mediate an adenylate cyclase Stimulation of up to SOOk of the control value. Similarly, the activation via these 10-20\% of receptors occurs with a halflife that is only 2 times Ionger than that in control membranes. This indicates the presence of a receptor reserve, with respect to both the extent and the rate of adenytate cyclase Stimulation. These observations require a modification of the models of receptor-adenytate cyclase coupling, which is described in the accompanying paper [Mol. Pharmacol. 39:524-530 (1991)].}, subject = {Adenosinrezeptor}, language = {en} } @incollection{SpielmannArendKlotzetal.1991, author = {Spielmann, W. S. and Arend, L. J. and Klotz, Karl-Norbert and Schwabe, U.}, title = {Adenosine control of the renal Collecting tubule: receptors and signaling}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86129}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1991}, abstract = {No abstract available.}, subject = {Adenosin}, language = {en} } @article{WilhelmZaccagnini1991, author = {Wilhelm, Gernot and Zaccagnini, Carlo}, title = {Excavations at Tell Karrana 3 (1985 and 1986)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85963}, year = {1991}, abstract = {no Abstract available}, subject = {Tell Karrana}, language = {en} } @article{BergerEllersiekSteinmueller1991, author = {Berger, Susanne and Ellersiek, Ulrike and Steinm{\"u}ller, Klaus}, title = {Cyanobacteria contain a mitochrondrial complex I-homologous NADH-dehydrogenase}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31223}, year = {1991}, abstract = {Thylakoid and cytoplasmic membranes of the cyanobacterium Syncchocystis sp. PCC 6803 were purified by sucrose gradient centrifugation. Both membranes oxidize NADH in a rotenone-sensitive reaction. Antibodies prepared against psbG/ndhKand ndhJ fusion proteins detect the corresponding polypeptides in both membrane preparations. This demonstrates that a NADH-dehydrogenase, homologous to the mitochondrial NADHubiquinone-oxidoreductase (complex I of the respiratory chain) is present in cyanobacteria, The NADH-dehydrogenase can be solubilized with the detergent /-D-dodecylmaltoside. Sedimentation analysis of the solubilized enzyme on a sucrose gradient indicates that it is a multisubunit protein complex.}, language = {en} } @article{HeinsenHeinsen1991, author = {Heinsen, Helmut and Heinsen, Y. L.}, title = {Serial thick, frozen, gallocyanin stained sections of human central nervous system}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45741}, year = {1991}, abstract = {A rapid method for macroscopic and microscopic investigation of human CNS is proposed. After fonnalin fixation, gelatin or agarose embedding, and cryoprotective treatment, frozen human spinal cords, brainstems, or hemispheres can be serially cut into 0.7 mm thick slices. Stained with gallocyanin-chromalum, these slices facilitate cytoarchitectonic, neuropathologic, and quantitative examination. Regions of interest from parallel fonnalin-stored unstained slices can be embedded into paraffin and stained by any irnrnunocytologic and histologic stain compatible with fonnalin fixation and paraffin embedding.}, language = {en} } @incollection{Ellgring1991, author = {Ellgring, Johann Heinrich}, title = {Introduction. The use of Video for behavior description and intervention}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42019}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1991}, abstract = {No abstract available}, language = {en} } @misc{SendtnerArakawaStoecklietal.1991, author = {Sendtner, Michael and Arakawa, Yoshihiro and St{\"o}ckli, Kurt A. and Kreutzberg, Georg W. and Thoenen, Hans}, title = {Effect of ciliary neurotrophic factor (CNTF) on motoneuron survival}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33048}, year = {1991}, abstract = {We have demonstrated that the extensive degeneration of motoneurons in the rat facial nucleus after transection of the facial nerve in newborn rats can be prevented by local ciliary neurotrophic factor (CNTF) administration. CNTF differs distinctly from known neurotrophic molecules such as NGF, BDNF and NT-3 in both its molecular characteristics (CNTF is a cytosolic rather than a secretory molecule) and its broad spectrum of biological activities. CNTF is expressed selectively by Schwann cells and astrocytes of the peripheral and central nervous system, respectively, but not by target tissues of the great variety of CNTF -responsive neurons. CNTF mRNA is not detectable by Northern blot or PCR analysis during embryonic development and immediately after birth. However, during the second post-natal week, a more than 30-fold increase in CNTF mRNA and pro tein occurs in the sciatic nerve. Since the period of low CNTF levels in peripheral nerves coincides with that of high vulnerability of motoneurons (i.e. axonallesion results in degeneration of motoneuron cell bodies), insufficient availability of CNTF may be the reason for the rate of lesioninduced cell death of early post-natal motoneurons. Highly enriched embryonic chick motoneurons in culture are supported at survival rates higher than 60\% by CNTF, even in single cell cultures, indicating that CNTF acts directly on motoneurons. In contrast to CNTF, the members of the neurotrophin gene family (NGF, BDNF and NT-3) do not support the survival of motoneurons in culture. However, aFGF and bFGF show distinct survival activities which are additive to those of CNTF, resulting in the survival of virtually all motoneurons cultured in the presence of CNTF and bFGF.}, language = {en} } @article{FialaMaschwitz1991, author = {Fiala, Brigitte and Maschwitz, Ulrich}, title = {Extrafloral nectaries in the genus Macaranga (Euphorbiaceae) in Malaysia: comparative studies of their possible significance as predispositions for myrmecophytism.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42863}, year = {1991}, abstract = {So me species of the paleotropical tree genus Macaranga (Euphorbiaceae) live in elose association with ants. Thc genus comprises the full range of species from those not regularly inhabited by ants to obligate myrmecophytes. In Malaysia (peninsular and Borneo) 23 ofthe 52 species areknown to be ant-associated (44\%). The simplest structural adaptation of plants to attract ants are extrafloral nectaries. We studied the distribution of extraflural nectaries in the genus Macaranga to assess the significance of this character as a possible predisposition for the evolution of obligate myrmecophytism. All species have marginal glands on the leaves. However, only the glands of nonmyrmecophytic species function as nectaries, whereas liquids secreted by these glands in myrmecophytic species did not contain sugar. Some non-myrmecophytic Macaranga and transitional Macaranga species in addition have extrafloral nectaries on the leaf blade near the petiole insertion. All obligatorily myrmecophytic Macaranga species, however, lack additional glands on the lamina. The non-myrmecophytic species are visited by a variety of different ant species, whereas myrmecophytic Macaranga are associated only with one specific ant-partner. Since these ants keep scale insects in the hollow sterns, reduction of nectary production in ant-inhabited Macaranga seems to be biologically significant. We interpret this as a means of (a) saving the assimilates and (b) stabilization of maintenance of the association's specificity. Competition with other ant species for food rewards is avoided and thereby danger ofweakening the protective function ofthe obligate antpartner for the plant is reduced. A comparison with other euphorb species living in the same habitats as Macaranga showed that in genera in which extrafloral nectaries are widespread, no myrmecophytes have evolved. Possession of extrafloral nectaries does not appear to be essential for the development of symbiotic ant-plant interactions. Other predispositions such as nesting space might have played a more important role.}, subject = {Macaranga}, language = {en} } @article{KaupmannSendtnerStoecklietal.1991, author = {Kaupmann, Klemens and Sendtner, Michael and St{\"o}ckli, Kurt A. and Jockusch, Harald}, title = {The gene of ciliary neurotrophic factor (cntf) maps to murine chromosome 19 and its expression is not affected in the hereditary motoneuron disease 'wobbler' of the mouse}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42626}, year = {1991}, abstract = {The cDNA for ciliary neurotrophic factor (CNTF), a polypeptide involved in the survival of motoneurons in mammals, has recently been cloned (St{\"o}ckli et al., Nature, 342, 920 - 923, 1989; Lin et al. Science, 246, 1023 - 1025, 1989). We have now localized the corresponding gene Cntf to chromosome 19 in the mouse, using an interspecific cross between Mus spretus and Mus musculus domesticus. The latter was carrying the gene wobbler (wr) for spinal muscular atrophy. DNA was prepared from backcross individuals and typed for the segregation of species-specific Cntf restriction fragments in relation to DNA markers of known chromosomal location. The M.spretus allele of Cntf cosegregated with chromosome 19 markers and mapped closely to Ly-1, to a region of mouse chromosome 19 with conserved synteny to human chromosome 11q. Cntf is not linked to wr, and the expression of CNTF mRNA and protein appears close to normal in facial and sciatic nerves, of affected (wr/wr) mice, suggesting that motoneuron degeneration of wobbler mice has its origin in defects other than reduced CNTF expression.}, language = {en} } @misc{DabauvalleScheer1991, author = {Dabauvalle, Marie-Christine and Scheer, Ulrich}, title = {Assembly of nuclear pore complexes in Xenopus egg extract}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-41194}, year = {1991}, abstract = {No abstract available}, language = {en} } @misc{Dandekar1991, author = {Dandekar, Thomas}, title = {Olbers' Paradox (peer-reviewed scientific correspondence)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31672}, year = {1991}, abstract = {No abstract available}, language = {en} } @article{WuBeckerWaagetal.1991, author = {Wu, Y. S. and Becker, Charles R. and Waag, A. and Bicknell-Tassius, R. N. and Landwehr, G.}, title = {The effects of laser illumination and high energy electrons on molecular-beam epitaxial growth of CdTe}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30795}, year = {1991}, abstract = {We report the results of a detailed investigation on the Te-stabilized (2 x 1) and the Cdstabilized c( 2 X 2) surfaces of ( 100) CdTe substrates. The investigation demonstrates for the first time that both laser illumination and, to a greater extent, high-energy electron irradiation increase the Te desorption and reduce the Cd desorption from ( 100) CdTe surfaces. Thus it is possible by choosing the proper growth temperature and photon or electron fluxes to change the surface reconstruction from the normally Te-stabilized to a Cd-stabilized phase.}, language = {en} }