@article{LohseKlotzSalzeretal.1988, author = {Lohse, Martin J. and Klotz, Karl-Norbert and Salzer, Manfred J. and Schwabe, Ulrich}, title = {Adenosine regulates the \(Ca^{2+} \) sensitivity of mast cell mediator release : (histamine secretion/inositol phosphates/calcium)}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {85}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127883}, pages = {8875-8879}, year = {1988}, abstract = {Mast cells release histamine and other mediators of allergy in response to stimulation of their IgE receptors. This release is generally thought to be mediated by an elevation of cytosolic \(Ca^{2+}\). Recent evidence suggests that there might be factors that modulate the coupling between \(Ca^{2+}\) levels and mediator release. The present report identifies adenosine as one such modulator. Adenosine and several of its metabolically stable analogues were shown to enhance histamine release from rat peritoneal mast cells in response to stimuli such as concanavalin A. Metabolizing endogenous adenosine with adenosine deaminase dampened the response to stimuli, whereas trapping endogenous adenosine inside mast cells with nucleoside-transport inhibitors markedly enhanced stimulated histamine release. The metabolically stable adenosine analogue 5' -(N-ethylcarboxamido)adenosine (NECA) did not affect the initial steps in the sequence from IgE-receptor activation to mediator release, which are generation of inositol trisphosphate and increase of cytosolic \(Ca^{2+}\). However, NECA did enhance the release induced in ATP-permeabilized cells by exogenous \(Ca^{2+}\), but it had no effect on the release induced by phorbol esters. These data suggest that adenosine sensitizes mediator release by a mechanism regulating stimulus-secretion coupling at a step distal to receptor activation and second-messenger generation.}, language = {en} } @inproceedings{KreuzerVejnarSchuessleretal.1988, author = {Kreuzer, Hans and Vejnar, Zdenek and Sch{\"u}ssler, Ulrich and Okrusch, Martin and Seidel, Eberhard}, title = {K-Ar dating of the last metamorphic events in different tectonic units of the western margin of the Bohemian Massif}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87527}, year = {1988}, abstract = {K-Ar dating on hornblendes and micas from the Tepl{\"a}Domazlice zone revealed a pattern of dates which significantly deviates from the mid-Carboniferous to early Permian one that is found in the adjacent low-pressure metamorphic Moldanubian and Saxothuringian. Especially for the Mari{\"a}nske L{\"a}zne metabasic complex, confirming early Czech determinations, the dates resemble the early Devonian pattern determined for the M{\"u}nchberg Gneiss Massif and the Erbendorf-Vohenstrauß zone of northeastern Bavaria. This supports the idea that all three units are remnants of a huge complex which suffered a metamorphic overprint under medium-pressure conditions, probably in the early Devonian. Streng rejuvenation is found in the southern part of the Tepl{\"a}-Domailice zone by which micas and even two hornblendes were reset to mid-Carboniferous ages. According to the geological setting, part of the apparently preDevonian dates may be explained by inherited argon from earlier metamorphic and magmatic events, e.g. the high-pressure metamorphism documented in eclogitic relics. However, excess argon, caused by the mid-Carboniferous overprint cannot be excluded.}, subject = {Geochemie}, language = {en} } @inproceedings{SchuesslerVejnarOkruschetal.1988, author = {Sch{\"u}ssler, Ulrich and Vejnar, Z. and Okrusch, M. and Rose, S. and Seidel, E.}, title = {Geochemistry of Metabasites and gabbroic rocks from the Tepla-Domazlice zone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87511}, year = {1988}, abstract = {Various amphibolites, metagabbros and eclogitic relics of the Mari{\"a}nske L{\"a}zne complex, and amphibolites from the Cern{\"a} Hora Massif exhibit an uniform geochemical character which compares weil with modern mid-ocean ridge basalts. Geochemically these metabasites are similar to the amphibolites of the Myto area and to schistose, partly striped amphibolites of the neighbouring Tirschenreuth-M{\"a}hring Zone and the Erbendorf-Vohenstrauss Zone (Bavaria). Greenschists and amphibolites from the Domazlice metamorphic complex show an alkaline-basaltic tendency conforming to modern within-plate basalts or basalts from anomalaus midocean ridge segments. In their chemical character, these metabasites compare weil with the flaseramphibolites of the Erbendorf-Vohenstrauss Zone. Fine-grained amphibolites in the Warzenrieth area and (gabbro-) amphibolites in the Bl{\"a}tterberg-Hoher Bogen area show normal MORB character. The metamorphosed gabbroic rocks in the southern part of the Neukirchen-Kdyne (meta-) igneous complex are subalkaline - tholeiitic and exhibit a magmatic differentiation trend. They differ from the neighbouring amphibolites by generally lower contents of incompatible elements.}, subject = {Geochemie}, language = {en} } @article{KurtzSchneider1988, author = {Kurtz, Beth E. and Schneider, Wolfgang}, title = {The effects of age, study time, and importance of text units on strategy use and memory for texts}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87408}, year = {1988}, abstract = {This study investigated study behavior and recall of a narrative text as a function of the reader's age, study time, and importance level of text units. Fifth graders, seventh graders, young- and older adults were asked to read a fairy tale, and do anything they liked to prepare for verbatim recall. Half of the subjects in each age group were assigned to an immediate recall condition; half were given additional study time. Examination of recall data showed that all subjects showed higher recall of important units in the text than unimportant units. This effect was independent of age and study time condition. Study behaviors varied significantly across age groups and study conditions: while adults underlined or took notes with equal frequency, children preferred note-taking as a study strategy. With additional study time, fifth graders, seventh graders, and older adults increased their strategic behavior; young adults did not.}, subject = {Studienzeit}, language = {en} } @inproceedings{MaurerBannertRethwilmetal.1988, author = {Maurer, B. and Bannert, H. and Rethwilm, Axel and Darai, B. and Fl{\"u}gel, R. M.}, title = {Characterization of the env gene and of two novel coding regions of the human spumaretrovirus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86334}, year = {1988}, abstract = {Recombinant clones harboring retroviral DNA were established. The nucleotide sequence of the central and 3' region of the genome of the human spumaretrovirus was determined. The 5' end of the deduced protein sequence was homologaus to the endonuclease domain of retroviral reverse transcriptases. A small intergenic region is followed by a lang open reading frame of 985 aminoacid residues that according to its genomic location and structural features is a typical retroviral env gene. Surprisingly, the postenv region contains two open reading frames that encodes two novel retroviral genes, termed bel-l and bel-2. The 3' LTR is 963 nucleotides lang and contains the signal sequences characteristic for transcriptional regulation of retrovirus genomes.}, subject = {Spumaviren}, language = {en} } @incollection{LohseKlotzSchwabeetal.1988, author = {Lohse, M. J. and Klotz, K.-N. and Schwabe, U. and Christalli, G. and Vittori, S. and Grifantini, M.}, title = {Pharmacology and Biochemistry of Adenosine Receptors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86251}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1988}, abstract = {Adenosine modulates a variety of physiological functions via membrane-bound receptors. These receptors couple via G proteins to adenylate cyclase and K+channels. The A1 subtype mediates an inhibition of adenylate cyclase and an opening of K+-channels, and the A2 subtype a Stimulation of adenylate cyclase. Both subtypes have been characterized by radioligand binding. This has facilitated the development of agonists and antagonists with more than 1000-fold A1 selectivity. A1-selective photoaffinity labels have been used for the biochemical characterization of A1 receptors and the study of their coupling to adenylate cyclase. Such selective ligands allow the analysis of the involvement of adenosine receptors in physiological functions. Selective interference with adenosine receptors provides new pharmacological tools and eventually new therapeutic approaches to a number of pathophysiological states.}, subject = {Adenosinrezeptor}, language = {en} } @article{MauelerBarnekowEigenbrodtetal.1988, author = {Maueler, W. and Barnekow, A. and Eigenbrodt, E. and Raulf, F. and Falk, H. F. and Telling, A. and Schartl, Manfred}, title = {Different regulation of oncogene expression in tumor and embryonal cells of Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86240}, year = {1988}, abstract = {Melanoma formation in the poeciliid fish Xiphophorus is mediated primarily by a cellular oncogene, designated Tu. Elimination of Tu-specific genes releases the transforming function of Tu and leads to melanoma formation. Southern blot analyses revealed a tight linkage of a v-erb B related gene to the Tu-locus and Northern blot analyses of RNA of solid melanomas indicated a coordinated deregulation and for mutational activation of several oncogenes. In order to get a better insight into the regulation of oncogene expression in normal and transformed cells of Xiphophorus, we studied the expression of Xsrc, Xras, Xmyc, Xerb A, Xsis, and the v-erb B related gene in a melanoma derived cell line (PSM) and an embryonic cell line (A2) under conditions of low growth factor supply. Both celllines express the Xsrc, Xmyc, and Xras genes, while PSM cells in addition express the v-erb B related gene and A2 cells the Xsis gene. In PSM cells serum deprivation leads to an accumulation of most of the oncogene mRNAs analysed. This is most apparent for a 5.0 kb transcript of the v-erb B related gene, probably due to an increase in transcript stability. The levels of these mRNAs returned to normal within 2h after stimulation with 10\% fetal calf serum. At the protein level we observed an initial decrease followed by an increase of the n-p60c-src kinase (the protein product of tbe Xsrc gene) activity in cells deprived of serum. Serum stimulation restored a normal pp60"-src kinase activity. In contrast serum deprivation of A2 cells reduced the transcript amounts of each of the oncogenes analysed. The same holds true for one beta-tubulin transcript, while the level of a second beta-tubulin transcript was unaffected. Serum stimulation led to a reactivation of Xras and Xsrc after a delay of approximately 48b. The pp60(c-src) kinase activity was found to be 6-10 times lower as compared to the PSM cells and did not differ between serum deprived and serum stimulated cells. Enzyme activities and isoenzyme patterns of several glycolytic enzymes were found to be not affected by serum deprivation and stimulation in both celllines.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{MaeuelerRaulfSchartl1988, author = {M{\"a}ueler, Winfried and Raulf, Friedrich and Schartl, Manfred}, title = {Expression of proto-oncogenes in embryonic, adult, and transformed tissue of Xiphophorus (Teleostei: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86233}, year = {1988}, abstract = {In Xiphophorus the causative, primary cellular oncogene for melanoma formation has been assigned by classical genetics to a sex-chromosomal locus, designated Tu. Activation of Tu was proposed to be the result of the elimination of Tu-specific regulatory genes which normally suppress the transforming function in the nontumorous state. In order to understand the role which known proto-oncogenes migbt play in this process, we have analysed the expression of src, erb A, erb B, ras, abl, sis and mil related genes from Xiphophorus during embryogenesis, in non-tumorous organs and in melanoma cells. For src, ras, erb B and sis a differential expression during embryogenesis and/or in normal organs was detected, with preferential expression of src in neural tissues, a high abundance of sis transcripts in an embryonal epitheloid cellline and of erbB transcripts in the head nephros. In melanoma cells ras, src and a v-erb B related gene were found to be expressed. The src gene most likely is more involved in secondary processes during tumor progression, while the expression of the v-erb B related gene might be transformation-specific because recently such a sequence was found to map to the close vicinity of the Tu-locus.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @incollection{WeinertSchneiderKnopf1988, author = {Weinert, Franz E. and Schneider, Wolfgang and Knopf, Monika}, title = {Individual differences in memory development across the life-span}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70666}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1988}, abstract = {Experimental research on memory development has typically focused on the description of universal development trends across the life span and the identification of major sources of development within this domain. However, there is a lack of studies investigating the preconditions and effects of interindividual variability within age groups across different memory tasks. Similarly, our knowledge about the stability of interindividual differences across the life span as well as the sources and the amount of intraindividual variability across memory tasks is scarce. In the present chapter, we concentrate on these neglected issues. First, theoretical assumptions concerning the interindividual and intraindividual variability of memory development are discussed. Next, empirical evidence is presented that seems suited to document the importance of these neglected issues. While we try to give a representative account of the literature, the emphasis is on more recent studies of memory development in children and elderly adults conducted in our laboratory. The results demonstrate that age-related changes and individual differences in the knowledge base are particularly important for describing and explaining individual differences in memory develoment. In comparison, the rote of stable individual differences in basic memory capacities in explaining variations in memory development is less clear given tbe conflicting empirical evidence. In the final section of the chapter consequences for future research are discussed.}, subject = {Ged{\"a}chtnisbildung}, language = {en} } @inproceedings{SchartlMaeuelerRaulfetal.1988, author = {Schartl, Manfred and M{\"a}ueler, Winfried and Raulf, Friedrich and Robertson, Scott M.}, title = {Molecular aspects of melanoma formation in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72689}, year = {1988}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{WinotoMorbachLeyhausenMuellerRuchholtzetal.1988, author = {Winoto-Morbach, S. and Leyhausen, G. and M{\"u}ller-Ruchholtz, W. and Ulrichs, Karin}, title = {The Electromagnetic Separation Principle: A Basis for Human Pancreatic Islet Transplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82520}, year = {1988}, abstract = {No abstract available}, subject = {Allergie}, language = {en} } @article{SchneiderSchauliesLiebertBaczkoetal.1988, author = {Schneider-Schaulies, Sibylle and Liebert, UG and Baczko, K, and ter Meulen, V.}, title = {Molecular Biological Analysis of Measles Virus Gene Expression in the CNS of Acutely and Persistently Infected Rat Brain Cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-81784}, year = {1988}, subject = {Virologie}, language = {en} } @article{SchneiderSchauliesLiebertBaczkoetal.1988, author = {Schneider-Schaulies, Sibylle and Liebert, UG and Baczko, K. and ter Meulen, V.}, title = {Molecular Biological Aspects of Virus-Induced Subacute Encephalomyelitis in Lewis Rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-81776}, year = {1988}, abstract = {no abstract available}, subject = {Biologie}, language = {en} } @article{SchmuckKobeltLinsenmair1988, author = {Schmuck, R. and Kobelt, F. and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperbolius viridiflavus (Anura, Hyperbolidae) to its arid environment: V. Iridophores and nitrogen metabolism}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78094}, year = {1988}, abstract = {Ofall amphibians living in arid habitats, reed frogs (belonging to the super species Hyperolius viridiflavus) are the most peculiar. Froglets are able to tolerate dry periods of up to 35 days or longer immediately after metamorphosis, in climatically exposed positions. They face similar problems to estivating juveniles, i.e. enduranee of long periods of high temperature and low RH with rather limited energy and water reserves. In addition, they must have had to develop meehanisms to prevent poisoning by nitrogenous wastes that rapidly accumulate during dry periods as a metabolie consequenee of maintaining a non-torpid state. During dry periods, plasma osmolarity of H. v. taeniatus froglets strongly increased, mainly through urea accumulation. Urea accumulation was also observed during metamorphic climax. During postmetamorphic growth, chromatophores develop with the density and morphology typical of the adult pigmentary pattern. The dermal iridophore layer, which is still incomplete at this time, is fully developed within 4-8 days after metamorphosis, irrespective of maintenance conditions. These iridophores mainly contain the purines guanine and hypoxanthine. The ability of these purines to reflect light provides an excellent basis for the role of iridophores in temperature regulation. In individuals experiencing dehydration stress, the initial rate of purine synthesis is doubled in eomparison to specimens continuously maintained under wet season conditions. This increase in synthesis rate leads to a rapid increase in the thiekness of the iridophore layer, thereby effectively reducing radiation absorption. Thus, the danger of overheating is diminished during periods of water shortage when evaporative cooling must be avoided. After the development of an iridophore layer of sufficient thickness for effective radiation reflectance, synthesis of iridophore pigments does not cease. Rather, this pathway is further used during the remaining dry season for solving osmotic problems eaused by accumulation of nitrogenous wastes. During prolonged water deprivation, in spite of reduced metabolic rates, purine pigments are produced at the same rate as in wet season conditions. This leads to a higher relative proportion of nitrogen end products being stored in skin pigments under dry season conditions. At the end of an experimental dry season lasting 35 days, up to 38\% of the accrued nitrogen is stored in the form of osmotically inactive purines in thc skin. Thus the osmotic problems caused by evaporative water loss and urea production are greatly reduced.}, subject = {Biologie}, language = {en} } @article{LinsenmairSchmuck1988, author = {Linsenmair, Karl Eduard and Schmuck, R.}, title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. III. Aspects of nitrogen metabolism and osmuregulation in the reed frog, H. viridiflavus taeniatus, with special reference to the role of iridophores}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78108}, year = {1988}, abstract = {Reed frogs of the superspecies Hyperolius viridiflavus occur throughout the seasonally very dry and hot African savannas. Despite their small size (300-700 mg), estivating reed frogs do not avoid stressful conditions above ground by burrowing into the soil, but endure the inhospitable climate relatively unprotected, clinging to mostly dry grass sterns. They must have emcient mechanisms to enable them to survive e.g. very high temperatures, low relative hurnidities, and high solar radiation loads. Mechanisms must also have developed to prevent poisoning by the nitrogenous wastes that inevitably result from protein and nucleotide turnover. In contrast to fossorial amphibians, estivating reed frogs do not become torpid. Reduction in metabolism is therefore rather Iimited so that nitrogenous wastes accumulate faster in these frogs than in fossorial amphibians. This severely aggravates the osmotic problems caused by dehydration. During dry periods total plasma osmolarity greatly increases, mainly due to urea accumulation. Of the total urea accumulated over 42 days of experimental water deprivation, 30\% was produced during the first 7 days. In the next 7 days rise in plasma urea content was negligible. This strong initial increase of urea is seen as a byproduct of elevated amino acid catabolism following the onset of dry conditions. Tbe rise in total plasma osmolarity due to urea accumulation, however, is not totally disadvantageous, but enables fast rehydration when water is available for very short periods only. Voiding of urine and feces eeases once evaporative water loss exceeds 10\% of body weight. Tberefore, during continuous water deprivation, nitrogenous end products are not excreted. After 42 days of water deprivation, bladder fluid was substantially depleted, and urea coneentration in the remaining urine (up to 447 mM) was never greater than in plasma fluid. Feces voided at the end of the dry period after water uptake contained only small amounts of nitrogenous end products. DSF (dry season frogs) seemed not to be uricotelic. Instead, up to 35\% of the total nitrogenous wastes produced over 42 days of water deprivation were deposited in an osmotically inert and nontoxic form in iridophore crystals. The increase in skin purine content averaged 150 µg/mg dry weight. If urea had been the only nitrogenous waste product during an estivation period of 42 days, lethal limits of total osmolarity (about 700 mOsm) would have been reached 10-14 days earlier. Thus iridophores are not only involved in colour change and in reducing heat load by radiation remission, but are also important in osmoregulation during dry periods. The seIective advantages of deposition of guanine rather than uric acid are discussed.}, subject = {Biologie}, language = {en} } @article{SirenFeuerstein1988, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Cardiovascular effects of rat calcitonin gene-related peptide in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63236}, year = {1988}, subject = {Neurobiologie}, language = {en} } @article{FeuersteinSiren1988, author = {Feuerstein, G. and Sir{\´e}n, Anna-Leena}, title = {Hypothalamic µ-receptors in the cardiovascular control: a review}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63228}, year = {1988}, abstract = {The endogenous opioid system includes three major families of peptides [22): dynorphins (derived from pre-proenkephalin B); endorphins (derived from pre-proopiomelanocortin) and enkephalins (derived from pre-proenkephalin A). Multiple species of opioid peptides are derived from these major precursors and many of them possess potent cardiovascular properties. Multiple forms of opioid receptors have been defined in the central nervous system. Although the relationship of these receptors to the multiple actions of the opioid systems is not weil understood, some predications can be made: in vitro the dynorphin-related peptidesbind preferentially to kappa-opioid receptors; the enkephalins bind preferentially to delta and JL-opioid receptors and while beta-endorphin binds to mu- and delta-, but not to kappa-opioid receptors. While littleis known on the roJe ofthe opioid system in normal cardiovascular regulation, it has become clear that cardiovascular stress situations substantially modify the activity ofthe endogenous opioid system. This review focuses on the mu-opioid system in the hypothalamus with special emphasis on its potential roJe in cardiovascular control of both normal and pathophysiologic states.}, subject = {Neurobiologie}, language = {en} } @article{Siren1988, author = {Sir{\´e}n, Anna-Leena}, title = {Cardiovascular pharmacology of thyrotropin releasing hormone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63214}, year = {1988}, subject = {Neurobiologie}, language = {en} } @article{FeuersteinSiren1988, author = {Feuerstein, G. and Sir{\´e}n, Anna-Leena}, title = {Mesenteric vascular responses to i.v. administration of lipoxin A\(_4\) and lipoxin B\(_4\) in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63200}, year = {1988}, abstract = {Lipoxin A (LXA\(_4\)) and lipoxin B\(_4\)(LXB\(_4\)) are newly discovered lipoxygenase-interacting products of leukocytes which might have a role in cardiovascular events associated with anaphylaxis. We have tested this possibility by systemic administration of both LXA\(_4\) and LXB\(_4\) to the conscious rat while monitaring systemic and regional hemodynamic changes. LXA\(_4\) and' LXB\(_4\) (l-100 pg/kg) produced dose-dependent constriction of the mesenteric vessels, up to + 123±23\% and +50±9\% for LXA\(_4\)/B\(_4\) , respectively. Dose-related changes were not observed in arterial blood pressure, heart rate, renal (LXB\(_4\)) and hindquarter blood ftow. We suggest that LXA\(_4\) and LXB\(_4\) might affect selective vascular beds, such as the mesenteric vessels, and contribute to variations in blood flow in specific pathophysiological states.}, subject = {Neurobiologie}, language = {en} } @article{SirenLettsFeuerstein1988, author = {Sir{\´e}n, Anna-Leena and Letts, G. and Feuerstein, G.}, title = {N-Acetyl-leukotriene E\(_4\) is a potent constrictor of rat mesenteric vessels}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63196}, year = {1988}, abstract = {N-Acetyl-leukotriene E\(_4\) administered to conscious freely moving rats produced a dose-dependent vasoconstriction in the mesenteric vessels which led to profound reduction of blood flow to the gut. Renal and hindquarter blood flow and vascular resistance were not affected even by high doses of N-acetyl-leukotriene E\(_4\) . N-Acetyl-leukotriene E\(_4\) was 10-fold more potent than the thromboxane analog U-46619 and 1000-fold more potent than prostaglandin F\(_{2a}\) but 2-5-fold less potent than leukotriene D\(_4\)/E\(_4\) to induce mesenteric vasoconstriction. These data indicatc that N-acetylleukotriene E\(_4\) is a biologically active metabolite of peptide leukotrienes, and might play a role in cardiovascular derangements mediated by leukotrienes.}, subject = {Neurobiologie}, language = {en} } @article{SirenLakeFeuerstein1988, author = {Sir{\´e}n, Anna-Leena and Lake, C. R. and Feuerstein, G.}, title = {Hemodynamic and neural mechanisms of action of thyrotropin releasing hormone in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63183}, year = {1988}, abstract = {Tbe mechanisms mediating the etl'ects ofthyrotropin-releasing hormone (TRH) on the cardiovascular system were studied in the conscious rat. Intracerebroventricolar (i.c. v.) injection of TRH (8 pmol-80 nmollkg) induced dose-dependent lncreases in mean arterial pressure, heart rate, and cardiac index. Rindquarter blood Oow increased due to vasodilation, while an lncrease in renal and mesenteric vascular resistance caused a decrease in blood Oow in the respective organs. The plasma Ievels of norepinephrine a~d epinephrine were increased by TRH, while there was no change in plasma renin activity or vasopressin. Tbe cardiovascular actions of i.c. v. TRH were not in.fluenced by blockade of the renin-angiotensin system or vasopressin receptors. Tbe ganglion blocker chlorisondamine and the a 1- aod al-adrenoreceptor antagooist phentolamlne (2 mg/kg i.v.) abolished the increase in blood pressure and mesenteric vasoconstriction after i.c. v. TRH. Propranolol (2 mg/kg i. v.) blocked the TRH-ioduced increase in cardiac index, heart rate, and hindquarter blood flow. The hindquarter vasodllatlon lnduced by TRH was also blocked by the selective ß1-adrenocept9r antagonist ICI 188,551 (1 or 2 mg/kg i.v.), while tbe ,8,-adrenoceptor blocker practolol (10 mg/kg i.v.) had no eft'ect on the hindquarter vasodiJation produced by TRH but totally blocked the increase in cardiac Index. In adrenal demedullated rats, the systemic hemodynamic eft'ects ofi.c. v. TRH were dimlnished along with the decrease in renal blood flow and lncrease in renal vascular resistance; however, the iocrease in hfndquarter blood flow was attenuated only in adrenal demedullated rats pretreated with the sympathetlc blocker bretylium. The renal vasoconstriction induced by i.c. v. TRH was not abolished by renal denervation. In sinoaortic debufl'ered rats, the pressor, tachycardic, and mesenteric vasoconstrictor responses to centrally administered TRH were significantly potentiated. Taken together, these data soggest that the putative rieurotransmitter TRH may play a role in central regulation of cardiac functions and organ blood flow distribution through both tbe sympathetic nerves and the adrenal medulla. A pivotal roJe for ß1-adrenoceptors in mediation ofhindquarter vasodilation ls also demonstrated.}, subject = {Neurobiologie}, language = {en} } @article{FeuersteinLettsSiren1988, author = {Feuerstein, G. and Letts, G. and Sir{\´e}n, Anna-Leena}, title = {N-Ac-Leukotriene E\(_4\): Unique vascular activity in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63171}, year = {1988}, abstract = {No abstract available}, subject = {Neurobiologie}, language = {en} } @article{StopperZimmermannNeil1988, author = {Stopper, Helga and Zimmermann, U. and Neil, G. A.}, title = {Increased efficiency of transfection of murine hybridoma cells with DNA by electropermeabilization}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63488}, year = {1988}, abstract = {Dispase-treated murine hybridoma cells (SP2/0-Ag14) were transfected with the G418 resistance gene bearing plasmid pSV2-neo by electropermeabilization with a high degree of efficiency. The cells were subjected to intermittent multiple high-voltage short duration (5 p.s) DC pulses at intervals of 1 min in a weakly conducting medium followed by selection in G418-containing medium. The transfection medium, temperature, pulse duration, and voltage were empirically determined by preliminary electropermeabilization experiments. Increasing the number of pulses resulted in a higher percentage of transfected cells, but a decrease in the number of viable cells, with the optimal transfectant yield resulting when five pulses of 10 kV jcm were administered. This method allows the rapid and efficient injection of DNA into mammalian cells, and permits the rapid production of stable, drug resistant hybridoma celllines for use in subsequent fusion experiments.}, subject = {Toxikologie}, language = {en} } @article{Schartl1988, author = {Schartl, Manfred}, title = {A sex chromosomal restriction-fragment-length marker linked to melanoma-determining Tu loci in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61842}, year = {1988}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlPeter1988, author = {Schartl, Manfred and Peter, R. U.}, title = {Progressive growth of fish tumors after transplantation into thymus-aplastic (nu/nu) mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61833}, year = {1988}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{AdamWittbrodtTellingetal.1988, author = {Adam, D. and Wittbrodt, J. and Telling, A. and Schartl, Manfred}, title = {RFLP for an EGF-receptor related gene associated with the melanoma oncogene locus of Xiphophorus maculatus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61822}, year = {1988}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @misc{Schneider1988, author = {Schneider, Wolfgang}, title = {Book Reviews: Cognition, Metacognition, and Reading}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62079}, year = {1988}, abstract = {No abstract available}, subject = {Psychologie}, language = {en} } @article{SchneiderSodian1988, author = {Schneider, Wolfgang and Sodian, Beate}, title = {Metamemory-memory behavior relationships in young children: Evidence from a memory-for-location task}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62062}, year = {1988}, abstract = {No abstract available}, subject = {Psychologie}, language = {en} } @article{EltzeGmelinWessetal.1988, author = {Eltze, M. and Gmelin, G. and Wess, J. and Strohmann, C. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G.}, title = {Presynaptic muscarinic receptors mediating inhibition of neurogenic contractions in rabbit vas deferens are of the ganglionic M\(_1\)-type}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63912}, year = {1988}, abstract = {The present study was designed to further charaeterize the presynaptie musearlnie M\(_1\)-reeeptor responsible for the inhibition of neuragenie eontraetions in the isolated rabbit vas deferens. Eleetrically induced twiteh eontraetions of this preparation were inhibited by the M\(_1\)-agonist, MeN-A-343, and by some of its analogs: 4-ehloro-phenyl derivative> MeN-A-343 > trans-olefinie analog> cis-olefinie analog. The same rank order of potency was observed for these agonists to raise the blood pressure of pithed rats by stimulation of M\(_1\)-receptors in sympathetie ganglia. A highly signifieant eorrelation was found between the antimusearinie potencies of atropine, pirenzepine and a series of 9 antagonists strueturally related to the ganglionie M\(_{1\beta}\)-receptor selective compounds, hexocyclium and hexahydro-difenidol, to antagonize the MeN-A-343-indueed inhibition of twitch eontraetions in rabbit vas deferens or the musearine-indueed depolarization in rat isolated superior eerVieal ganglia. It is suggested that the presynaptie musearlnie receptor that mediates inhibition of neuragenie contraetions in rabbit vas deferens is of the ganglionic M\(_{1\beta}\)-type.}, subject = {Anorganische Chemie}, language = {en} } @article{SyldatkStoffregenWuttkeetal.1988, author = {Syldatk, C. and Stoffregen, A. and Wuttke, F. and Tacke, Reinhold}, title = {Enantioselective reduction of acetyldimethylphenylsilane: a screening with thirty strains of microorganisms}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63906}, year = {1988}, abstract = {Thirty strains of microorganisms (bacteria, yeasts, fungi and green algae) were tested as resting free cells for their ability to transform acetyldimethylphenylsilane (1) enantioselectively into (R)-(1-hydroxyethyl) dimethylphenylsilane [(R)-2]. The biotransformations were monitared by GC (packed OV-17 column), and the enantiomeric purities of the products isolated were determined by HPLC (cellulose triacetate column, UV detection). All microorganisms tested were found to reduce 1 enantioselectively to give (R)-2. Under the test conditions used, the yeast Trigonapsis variabilis (DSM 70714) was found to 1 exhibif the highest specific activity (1.5 mg product x g cell wet mass\(^{-1}\) x min\(^{-1}\) ), whereas the highest enantioselectivities were observed for the bacteria Acinetobacter ca lcoaceticus (ATCC 31012) (>95\% ee), Brevfbacterium species (ATCC 21860) (90\% ee) and Corynebacterium dioxydans (ATCC 21766) (>95\% ee), the yeast Candida humico la (OSM 70067) (90\% ee), the fungus Cunninghame lla e legans (ATCC 26269) (94\% ee), as well as the cyanobacterium Synechococcus leopoliensis (94\% ee).· From the green algae tested, Chlamydomonas reinhardii showed the highest.enantioselectivity (85\% ee).}, subject = {Anorganische Chemie}, language = {en} } @article{LambrechtFeifelForthetal.1988, author = {Lambrecht, G. and Feifel, R. and Forth, B. and Strohmann, C. and Tacke, Reinhold and Mutschler, E.}, title = {p-Fluoro-hexahydro-sila-difenidol: the first M\(_{2\beta}\)-selective muscarinic antagonist}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63872}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{LambrechtGmelinRafeineretal.1988, author = {Lambrecht, G. and Gmelin, G. and Rafeiner, K. and Strohmann, C. and Tacke, Reinhold and Mutschler, E.}, title = {o-Methoxy-sila-hexocyclium: a new quaternary M\(_1\)-selective muscarinic antagonist}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63862}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{SargeCammengaBeckeretal.1988, author = {Sarge, S. and Cammenga, H. K. and Becker, B. and Rohr-Aehle, R. and Tacke, Reinhold}, title = {Energetic and kinetic investigation of thermally induced molecular rearrangements of esters of (hydroxymethyl)hydridosilanes by DSC}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63850}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{LutzDeuberCaviezeletal.1988, author = {Lutz, Werner K. and Deuber, R. and Caviezel, M. and Sagelsdorff, P. and Friederich, U. and Schlatter, C.}, title = {Trenbolone growth promotant: covalent DNA binding in rat liver and in Salmonella typhimurium, and mutagenicity in the Ames test}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60897}, year = {1988}, abstract = {DNA binding in vivo: (6,7-\(^3\)H]ß-trenbolone (ß-TBOH) was administered p.o. and i.p. to rats. After 8 or 16 h, DNA was isolated from the livers and purified to constant specific radioactivity. Enzymatic digestion to deoxyribonucleotides and separation by HPLC revealed about 90\% ofthe DNA radioactivity eluting in the form of possible TBOH-nucleotide adducts. The extent of this genotoxicity, expressed in units of the Covalent Binding Index, CBI = (~mol TBOH bound per mol nucleotide)/(mmol TBOH administered per kg body weight) spanned from 8 t~ 17, i. e. was in the range found with weak genotoxic carcmogens. Ames test: low doses of ß-TBOH increased the number of revertants in Salmonella strain TAl 00 reproducibly and m a dose-dependent manner. The mutagenic potency was 0.2 revertants per nmol after preincubation of the bacteria (20 min at 37° C) with doses between 30 and 60 \(\mu\)g per plate (47 and 94 \(\mu\)g/ml preincubation mixture). Above this dose, the number of revertants decreased to control values, accompanied by a reduction in survival. The addition of rat liver S9 inhibited the mutagenicity. DNA binding in vitro: calf thymus DNA was incubated with tritiated ß-TBOH with and without rat liver S9 Highest DNA radioactivities were determined in the absence of the "activation" system. Addition of inactive S9 (without cofactors) reduced the DNA binding by a factor of up to 20. Intermediate results were found with active S9. DNA binding in Salmonella: ß-TBOH was irreversibly bound to DNA isolated from S. typhimurium TA100 after incubation of bacteria with [\(^3\)H]ß-TBOH. Conclusions: Covalent DNA binding appears to be the mechanism of an activation-independent ("direct") mutagenicity of TBOH which is not easily detected because of the bactericidal activity. The genotoxicity risk arising from exposure of humans to trenbolone residues in meat was estimated using the in vivo data and compared to that from the exposure to unavoidable genotoxins aflatoxin B1 and dimethylnitrosamine. It ts concluded that trenbolone residues represent only a low genotoxic risk.}, subject = {Toxikologie}, language = {en} } @article{LutzMaier1988, author = {Lutz, Werner K. and Maier, P.}, title = {Genotoxic and epigenetic chemical carcinogenesis: one process, different mechanisms}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60884}, year = {1988}, abstract = {Chemieals that induce cancer in an intact organism are called carcinogens. This term does not differentiale between their various modes of action. In this review, Werner Lutz and Peter Maier make a mechanistic distinction between carcinogens that alter the genetic information and carcinogens that interfere with epigenetic processes. They considercardnogenesis tobe an ongoing, part1y unavoidable process which is based on a succession of mutations, most likely in stem cells, leading to autonomaus cellular growth regulation. Chemical carcinogens either induce such changes through mutations (genotoxic carcinogens) or they aceeierate the accumulation of critica1 spontaneaus mut11tions (epigenetic carcinogens). Examples are given for both classes of carcinogens, and for the processes that act at genoto:tic/nuclear 11nd epigenetic/mitotic Ievels.}, subject = {Toxikologie}, language = {en} } @article{SagelsdorffLutzSchlatter1988, author = {Sagelsdorff, P. and Lutz, Werner K. and Schlatter, C.}, title = {DNA methylation in rat liver by daminozide, 1,1-dimethylhydrazine, and dimethylnitrosamine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60875}, year = {1988}, abstract = {DNA Methylation in Rat Li ver by Daminozide, 1, 1-Dimethylhydrazine, and Dimethylnitrosamine. SAGELSDORFF, P., LUTZ, W. K., AND ScHLAITER C. (1988). Fundam. Appl. Toxico/. 11, 723-730. [methyP4C]Daminozide (succinic acid 2',2'-dimethylhydrazide; 37 mgjkg), l,l( 14C]dimethylhydrazine (UDMH; 19 mgtkg), and (14C]dimethylnitrosamine (DMNA; 0.1 mg/ kg) were administered by oral gavage to male Sprague-Dawley rats. After 24 hr, the animals were killed and DNA was purified from the livers to constant specific radioactivity. After enzymatic degradation of the DNA to the 3'-deoxynucleotides the Ievel of DNA methylation was determined by HPLC analysis. Radiolabeled 7-methylguanine (7mG) was identified by cochromatography with unlabeled 7mG added as standard after acidic depurination of DNA and HPLC analysis ofpurines and apurinic acid. All three compounds were found to methylate DNA. The relative potencies were 1:47:4900 for daminozide:UDMH:DMNA. With [methyPH]UDMH, the formation of7mG was investigated as a function of dose administered, at 20, 2, and 0.2 mgj kg. The methylation ofDNA was strictly proportional to the dose. The data were used to compare the Ievel of DNA alkylation derived from residues of daminozide and UDMH in treated apple with the genotoxicity of the intake of N-nitroso compounds in Germany and Japan. It is estimated that these residues could Iead to a DNA methylation in the Ii ver of about 6\% of an average exposure to DMNA}, subject = {Toxikologie}, language = {en} } @article{KlotzLohseSchwabe1988, author = {Klotz, Karl-Norbert and Lohse, M. J. and Schwabe, U.}, title = {Chemical modification of A\(_1\) adenosine receptors in rat brain membranes - evidence for histidine in different domains of the ligand binding site}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60295}, year = {1988}, abstract = {Chemical modification of amino acid residues was used to probe the ligand recognition site of A\(_1\) adenosine receptors from rat brain membranes. The effect of treatment with group·specific reagents on agonist and antagonist radioligand binding was investigated. The histidine-specific reagent diethylpyrocarbonate (DEP) induced a loss of binding of the agonist R-N\(^6\)-[\(^3\)H]phenylisopropyladenosine ([\(^3\)H]PIA), which could be prevented in part by agonists, but not by antagonists. DEP treatment induced also a loss of binding of the antagonist [\(^3\)H]8- cyclopentyl-1 ,3-dipropylxanthine ([\(^3\)H]DPCPX). Antagonists protected A\(_1\) receptors from this inactivation while agonists did not. This result provided evidence for the existence of at least 2 different histidine residues involved in ligand binding. Consistent with a modification of the binding site, DEP did not alter the affinity of [\(^3\)H]DPCPX, but reduced receptor number. From the selective protection of [\(^3\)H] PIA and [\(^3\)H]DPCPX binding from inactivation, it is concluded that agonists and antagonists oocupy different domains at the binding site. Sulfhydryl modifying reagents did not influence antagonist binding, but inhibited agonist binding. This effect is explained by modification of tbe inhibitory guanine nucleotide binding protein. Pyridoxal 5-phosphate inactivated both [\(^3\)H]PIA and [\(^3\)H]DPCPX binding, but the receptors could not be protected from inactivation by ligands. Therefore, no amino group seems to be located at the Iigand binding site. In addition, it was shown that no further amino acids witb polar side chains are present. The absence of bydrophilic amino acids frout the recognition site of the receptor apart from histidine suggests an explanation for the lack of hydrophilic ligands with high affinity for A\(_1\) receptors.}, subject = {Toxikologie}, language = {en} } @article{LohseKlotzDiekmannetal.1988, author = {Lohse, M. J. and Klotz, Karl-Norbert and Diekmann, E. and Friedrich, K. and Schwabe, U.}, title = {2',3'-Dideoxy-N\(^6\)-cyclohexyladenosine: an adenosine derivative with antagonist properties at adenosine receptors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60282}, year = {1988}, abstract = {Tbe 2',3'-dideoxy analogue of the potent A\(_1\) receptor agonist, N\(^6\)-cyclohexyladenosine (CHA), was synthesized as a potential antagonist for the A\(_1\) adenosine receptor. In sturlies on adenylate cyclase 2',3'-dideoxy-N\(^6\)-cyclohexyladenosine (ddCHA) did not show agonist properties at A\(_1\) or at A\(_2\) receptors. However, it antagonized the inhibition by R-PIA of adenylate cyclase activity of fat cell membranes via A\(_1\) receptors with a K\(_i\) value of 13 \(\mu\)M. ddCHA competed for the binding of the selective A1 receptor antagonist, [\(^3\) HJ8-cyclopentyl-1,3-dipropylxantbine ([\(^3\)H]DPCPX), to rat brain membranes with a K\(_i\) value of 4.8 \(\mu\)M; GTP did not affect the competition curve. In contrast to the marked stereoselectivity of the A\(_1\) receptor for the cx- and the natural ß-anomer of adenosine, the cx-anomer of ddCHA showed a comparable affinity for the A\(_1\) receptor (K\(_i\) value 13.9 \8\mu\)M). These data indicate that the 2'- and 3'-hydroxy groups of adenosine and its derivatives are required foragonist activity at and high affinity binding to A\(_1\) adenosine receptors and for the distinction between the cx- and ß-forms.}, subject = {Toxikologie}, language = {en} } @article{LohseKlotzSchwabeetal.1988, author = {Lohse, M. J. and Klotz, Karl-Norbert and Schwabe, U. and Cristalli, G. and Vittori, S. and Grifantini, M.}, title = {2-Chloro-N\(^6\)-cyclopentyladenosine: a highly selective agonist at A\(_1\) adenosine receptors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60279}, year = {1988}, abstract = {2-Chloro-N\(^6\)-cyclopentyladenosine (CCPA) was synthesized as a potential high affinity ligand for At adenosine receptors. Binding of [\(^3\)H]PIA to A1 receptors of rat brain membranes was inhibited by CCP A with a Ki-value of 0.4 nM, compared to a Ki-value of 0.8 nM for the parent compound N\(^6\)-cyclopentyladenosine (CPA). Binding of [\(^3\)H]NECA to A\(_2\) receptors of rat striatal membranes was inhibited with a Ki-value of 3900 nM, demonstrating an almost 10,000-fold A\(_1\)-selectivity of CCPA. CCP A inhibited the activity of rat fat cell membrane adenylate cyclase, a model for the A\(_1\) receptor, with an IC\(_{50}\)-value of 33 nM, and it stimulated the adenylate cyclase activity of human platelet membranes with an EC\(_{50}\)-value of 3500 nM. The more than 100-fold A\(_1\)-selectivity compares favourably with a 38-fold selectivity of CPA. Thus, CCPA is an agonist at A\(_1\) adenosine receptors with a 4-fold higher selectivity and 2-fold higher affinity than CPA, and a considerably higher selectivity than the standard At receptor agonist R-N\(^6\) -phenylisopropyladenosine (R-PIA). CCP A represents the agonist with the highest selectivity for A\(_1\) receptors reported so far.}, subject = {Toxikologie}, language = {en} } @article{CristalliFranchettiGrifantinietal.1988, author = {Cristalli, G. and Franchetti, P. and Grifantini, M. and Vittori, S. and Klotz, Karl-Norbert and Lohse, M. J.}, title = {Adenosine receptor agonists: Synthesis and biological evaluation of 1-deaza analogues of adenosine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60262}, year = {1988}, abstract = {In a search for more selective A\(_1\) adenosine receptor agonists, N\(^6\)-[(R)-(-)-1-methyl-2-phenethyl]-1-deazaadenosine (1-deaza-R-PIA, 3a), N\(^6\)-cyclopentyl-1-deazaadenosine (1-deazaCPA, 3b), N\(^6\)-cyclohexyl-l-deazaadenosine (1-deazaCHA, Sc), and the corresponding 2-chloro derivatives 2a-c were synthesized from 5,7-dichloro-3-ß-D-ribofuranosyl-3Himidazo[ 4,5-b]pyridine (1). On the other band, N-ethyl-1'-deoxy-1'-(1-deaza-6-amino-9H-purin-9-yl)-ß-D-ribofuranuronamide (1-deazaNECA, 10) was prepared from 7-nitro-3-ß-D-ribofuranosyl-3H-imidazo[4,5-b]pyridine (4), in an attempt to find a more selective A\(_2\) agonist. The activity of all deaza analogues at adenosine receptors has been determined in adenylate cyclase andin radioligand binding studies. 1-DeazaNECA (10) proved tobe a nonselective agonist at both subtypes of the adenosine receptor. It is about 10-fold less active than NECA but clearly more active than the parent compound 1-deazaadenosine as an inhibitor of platelet aggregation and as a stimulator of cyclic AMP accumulation. The N\(^6\)-substituted 1-deazaadenosines largely retain the A\(_1\) agonist activity of their parent compounds, but lose some of their A\(_2\) agonist activity. This results in A\(_1\)-selective compounds, of which N\(^6\)cyclopentyl- 2-chloro-1-deazaadenosine (1-deaza-2-Cl-CPA, 2b) was identified as the most selective agonist at A\(_1\) adenosine receptors so far known. The activity of all 1-deaza analogues confirms that the presence of the nitrogen atom at position 1 of the purine ring is not critical for A\(_1\) receptor mediated adenosine actions.}, subject = {Toxikologie}, language = {en} } @article{LohseElgerLindenbornFotinosetal.1988, author = {Lohse, M. J. and Elger, B. and Lindenborn-Fotinos, J. and Klotz, Karl-Norbert and Schwabe, U.}, title = {Separation of solubilized A\(_2\) adenosine receptors of human platelets from non-receptor [\(^3\)H]NECA binding sites by gel filtration}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60309}, year = {1988}, abstract = {Human platelet membranes were solubilized with the zwitterionic detergent CHAPS (3-[3-(cholamidopropyl)dimethylammonio]- 1-propanesulfonate) and the solubilized extract subjected to gel ftltration. Binding of the adenosine receptor agonist [\(^3\)H]NECA (5'-N-ethylcarboxamidoadenosine) was measured to the eluted fractions. Two [\(^3\)H]NECA binding peaks were eluted, the first of them with the void volume. This first peak represented between 10\% and 25\% of the [\(^3\)H]NECA binding activity eluted from the column. It bound [\(^3\)H]NECA in a reversible, saturable and GTPdependent manner with an affinity of 46 nmol/1 and a binding capacity of 510 fmol/mg protein. Various adenosine receptor ligands competed for the binding of [\(^3\)H]NECA to the frrst peak with a pharmacological proftle characteristic for the A\(_2\) adenosine receptor as determined from adenylate cyclase experiments. In contrast, most adenosine receptor ligands did not compete for [\(^3\)H]NECA binding to the second, major peak. These results suggest that a solubilized A\(_2\) receptor-Gs protein complex of human platelets can be separated from other [\(^3\)H]NECA binding sites by gel filtration. This allows reliable radioligand binding studies of the A2 adenosine receptor of human plate1ets.}, subject = {Toxikologie}, language = {en} } @article{MunoaHackerJuarez1988, author = {Munoa, F. and Hacker, J{\"o}rg and Juarez, A.}, title = {Characterization of a chromosomal mutant that blocks hemolysin excretion in Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59534}, year = {1988}, abstract = {We analyzed an Escherichia coli strain which harbours a chromosomal mutation that blocks the hemolysin excretion. Compartmentation studies showed that hemolysin accumulates in the cytoplasm and not in the periplasm. The mutation did not affect the SDS-PAGE protein pattern of the outer membrane, although some alterations were apparent in the periplasmic protein pattern. The mutant strain, E. coli Hsb-1 also failed to export a cloned fimbrial adhesin. The mutation maps in the min. 3.5 of the E. coli genetic map.}, subject = {Infektionsbiologie}, language = {en} } @article{PawelzikHeesemannHackeretal.1988, author = {Pawelzik, M. and Heesemann, J. and Hacker, J{\"o}rg and Opferkuch, W.}, title = {Cloning and characterization of a new type of fimbria (S/F1C-related fimbria) expressed by an Escherichia coli O75:K1:H7 blood culture isolate}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59529}, year = {1988}, abstract = {The Escherichia coli blood culture isolate BK658 (07S:K1:H7) expresses F1A and F1B fimbriae as weil as a third fimbrial type which reacts with anti-S-fimbrial antiserum but fails to show S-specific binding properlies (i.e., agglutination of bovine erythrocytes). To characterize these fimbriae, we cloned the respective genetic determinant in E. coli K-12. The resulting recombinant clone HB101(pMMP658-6) expresses fimbriae of 1.2-p.m length and a diameter of approximately 7 nm. The determinant codes for the fimbrillin subunit, a protein of 17 kUodaltons in size, and for at least five other proteins of 87, 31, 23, 14.3, and 13.8 kUodaltons. By restriction analysis and by DNA-DNA hybridization, it could be shown that the cloned fimbrial determinant of strain BK658 exhibits a high degree of sequence homology to the gene clusters coding for S fimbrial adhesins (sfa) and F1C fimbriae (/oc). By using the Western blot (immunoblot) technique and a quantitative enzyme-linked immunosorbent assay, it could be further demonstrated that the cloned fimbriae of BK658, S fimbriae, and FlC fimbriae share cross-reactive epitopes as weil as antigenic determinants specific for each fimbrial type. No antigenic cross-reactivity with F1C fimbriae could be detected. The results indicate a genetical and serological relatedness of the cloned fimbriae toS fimbriae and F1C fimbriae. Therefore, this new type of fimbriae is preliminarily termed SIF1C-related fimbriae (Sfr).}, subject = {Infektionsbiologie}, language = {en} } @article{OttHoschuetzkyJannetal.1988, author = {Ott, M. and Hosch{\"u}tzky, H. and Jann, K. and Van Die, I. and Hacker, J{\"o}rg}, title = {Gene clusters for S fimbrial adhesin (sfa) and F1C Fimbriae (foc) of Escherichia coli: Comparative aspects of structure and function}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59519}, year = {1988}, abstract = {Fimbrial 8dhesins en8ble b8cteria to 8ttach t9 eucaryotic ceU~. The genetic determin8nts for S fimbrial 8dhesins (sja) an.d for FlC ("pseudotype I") fimbri8e ifoc) were compared. Sfa and FlC represent functionally distinct 8dbesins in tbeir receptor specificities. Nevertheless, 8 high degree of bomology between both determin8nts was found on the basis of DNA-DNA hybridizations. Characteristic difl'erences in the restriCtion maps of tbe corresponding gene clusters, bowever, were visible in regions coding for the fimbrial subunits and for the S-specific 8dhesin. While a plasmid carrying the geneiic deternlinant for FlC fimbri8e was 8ble to complement transposon-induced sfa mutants, 8 plasmid carrying tbe genetic determin8nt for 8 tbird 8dht\$in type, termed P fimbriae, was un8ble to do so. Proximal sfa-specific sequences carrying the S fimbrial st'"uctural gene were fused to sequences representing tbe di\$tal part of the foc gene cluster to form 8 hybrid cluster, and tbe foc proxim~ region coding for tbe structural protein was Iigated to sfa distal sequences to form 8 second hybrid. Botb hybrid clones produced intact fimbriae. Anti-FlC monoclonal8ntibodies (MAbs) only recognized clones which produced FlC fimbriae, and an ~ti-S 8dhesin MAb marked clones whicb expressed the S adhesin. Bowever, one of four other anti-S fimbri8e-specific MAbs reacted witb both fimbrial structures, S and FlC, indicating 8 common epitope on both antigens. The results presented bere ~upport tbe view th8t sfa and foc determinants code for fimbri8e tb8t 8re simil8r in several aspects, wbile the P fimbri8e are members of 8 more distantly rel8ted group.}, subject = {Infektionsbiologie}, language = {en} } @article{ParkkinenKorhonenPereetal.1988, author = {Parkkinen, J. and Korhonen, T. K. and Pere, A. and Hacker, J{\"o}rg and Soinila, S.}, title = {Binding sites in the rat brain for Escherichia coli S fimbriae associated with neontal meningitis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59500}, year = {1988}, abstract = {Escherichia coli strains that cause sepsis and meningitis in neonatal infants carry S fimbriae that bind to sialyl galactoside units of cell surface glycoproteins. To investigate the possible role of S fimbriae in determining the tissue tropism of neonatal menlngitis, we have studied the preselice of binding sites for S fimbriae in different tissues of the neonatal rat which is susceptible to meningitis caused by S-fimbriated E. coli. Purified S fimbriae were incubated on cryostat sections of different rat oipns and their bindina was assessed by indirect immunofluorescence. In the bnin of the neonatal rat, S fimbriae specifically bound to the luminal surfaces of the vascular endothelium and of the epithelium lining the choroid plexuses and bnin ventricles. The · bindlog W.s completely inhibited by the trisaccharide NeuAca2-3Ga)ßl-4Gic, a receptor analogue of S fimbriae, and by a preceding neuraminidase treatment of the sections. A recombinant E. coli strain expressina S fimbriae adhered in large numbers to the same tissue sites in the neonatal brain sections as did the purified fimbriae, · whereas the nonfimbriated host strahi and a recombiiuuit strain expresslog P fi.mbriae did not adhere to brain tissues. The results soggest that adhesion of S-fimbriated bacteria to the binding sites observed in the neonatai bnin has a pathogenetic roJe durlog bacterial Invasion from cii'culation into the cerebrospinal fluid.}, subject = {Infektionsbiologie}, language = {en} } @article{EngelsPeyerimhoffKarnaetal.1988, author = {Engels, Bernd and Peyerimhoff, S.D. and Karna, S.P. and Grein, F.}, title = {The hyperfine coupling constants of the five lowest states of CH : An ab initio MRD-CI study}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58807}, year = {1988}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{EngelsPeyerimhoff1988, author = {Engels, Bernd and Peyerimhoff, S.D.}, title = {Study of the 1s and 2s shell contributions to the isotropic hyperfine coupling constant in nitrogen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58793}, year = {1988}, abstract = {The istropic part of the hyperfine coupling constant is investigated by means of multireference configuration interaction calculations employing Gaussian basis sets. A detailed study of the 1s and 2s spin polarisation in the nitrogen atom and the NH molecule shows that the structure of the lower-energy space of the unoccupied orbitals is essential for the results. A contraction of the Gaussian basis is possible without loss of accuracy if enough flexibility is retained to describe the main features of the original space of unoccupied functions. Higher than double excitations are found to be non-negligible for the description of α\(_{iso}\).}, subject = {Organische Chemie}, language = {en} } @article{MollScollayMitchell1988, author = {Moll, Heidrun and Scollay, R. and Mitchell, G. F.}, title = {Resistance to cutaneous leishmaniasis in nude mice injected with L3T4+ T cells but not with Ly-2+ T cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61269}, year = {1988}, abstract = {No abstract available}, subject = {Biologie}, language = {en} } @article{ChristlKraft1988, author = {Christl, Manfred and Kraft, A.}, title = {Tricyclo[3.1.1.0\(^{2,6}\)]hexandion (the Valen of o-Benzochinons), Bicyclo[2.1.1]hexan-2,3-dion and Valene of a Chinoxalins, of Phenazins and of a Benzophenazine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58462}, year = {1988}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{GoebelKathariouKuhnetal.1988, author = {Goebel, Werner and Kathariou, S. and Kuhn, M. and Sokolovic, Z. and Kreft, J{\"u}rgen and K{\"o}hler, S. and Funke, D. and Chakraborty, T. and Leimeister-W{\"a}chter, M.}, title = {Hemolysin from Listeria-biochemistry, genetics and function in pathogenesis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60563}, year = {1988}, abstract = {No abstract available}, subject = {Biologie}, language = {en} } @article{GoebelChakrabortyKreft1988, author = {Goebel, Werner and Chakraborty, T. and Kreft, J{\"u}rgen}, title = {Bacterial hemolysins as virulence factors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60553}, year = {1988}, abstract = {No abstract available}, subject = {Biologie}, language = {en} } @article{ChristlFreundHennebergeretal.1988, author = {Christl, Manfred and Freund, S. and Henneberger, H. and Kraft, A. and Hauck, J. and Irngartinger, H.}, title = {Several Polycyclic Valence Isomers of Dimethyl [14]Annulene-1,8-dicarboxylate. Reactivity of a "Nonconjugated" Bis(bicyclo[1.1.0]butane)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58413}, year = {1988}, abstract = {Diels-Alder reaction of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (5) with benzvalene (4), norbornene, and norbornadiene afforded the azo compounds 7 and 8. Theseare derivatives of 2,3-diazabicyclo[2.2.2]oct-2-ene as is azo compound 3, which had been obtained previously from 5 and 2 equiv of benzvalene (4). The photochemical extrusion of nitrogen from 3, 7, and 8 has been studied. Whereas 7 and 8 on direct irradiation in benzene gave rise exclusively to the bicyclo[2.2.0]hexane derivatives 9 and 10, respectively, from 3 in addition to the bicyclo[2.2.0]hexane 11, the diolefin 1l was formed. Diolefin 12 has cisdouble bonds in the nine-membered ring and is fixed in a boat conformation in a manner so that the two bicyclobutane systems approach each other very closely. This geometry suggests the unusual ring opening of the intermediate 1,4-cyclohexanediyl diradical from a boat conformation, which arises by inversion of the primarily generated boat conformation. Sensitized photolysis of 3 as weilasthat of ll produced the saturated isomer 13 of 11 and 12. The proximity of the bicyclobutane systems in 1l causes unprecedented reactions leading to cage compounds. When ll was heated at 90 °C, a rearrangement to the pentacyclic product 10 took place. Utilization of tetradeuteriated substrate ll-d4 supported a pathway with two diradical intermediates. Behaving in a convcntional manncr, bicyclobutane 9 and bis(bicyclobutane) 11 took up 1 and 2 equiv of thiophenol most probably in a radical-chain addition to give the thioethers 28 and 19, respectively. In contrast, bis(bicyclobutane) ll was converted by 1 equiv of thiophenol into cagc compound 30 in a process involving both the strained a systems. Heating at 80 °C subjected 30 to a reversible Copc rearrangement, resulting in a 6:1 mixture of 31 and 30. When it was treated with bromine, 11 was transformed to cage compound 38. This addition is believed to proceed via a cationic intermediate. The structure of cage compound 10 was established by a singlc-crystal X-ray analysis of dialcohol 11 prepared from 20 and methyllithium.}, subject = {Organische Chemie}, language = {en} } @article{GesslerBruns1988, author = {Gessler, Manfred and Bruns, Gail A. P.}, title = {Molecular mapping and cloning of the breakpoints of a chromosome 11p14.1-p13 deletion associated with the AGR syndrome}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59264}, year = {1988}, abstract = {Chromosome 11p13 is frequently rearranged in individuals with the WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) or parts of this syndrome. To map the cytogenetic aberrations molecularly, we screened DNA from cell Unes with known WAGR-related chromosome abnormalities for rearrangements with pulsed fleld gel (PFG) analysis using probes deleted from one chromosome 11 homolog of a WAGR patient. The first alteration was detected in a cell line from an individual with aniridia, genitourinary anomalies, mental retardation, and a deletion described as 11p14.1-p13. We have located one breakpoint close to probe HU11-164B and we have cloned both breakpoint sites as well as the junctional fragment. The breakpoints subdivide current intervals on the genetic map, and the probes for both sides will serve as important additional markers for a long-range restriction map of this region. Further characterization and sequencing of the breakpoints may yield insight into the mechanisms by which these deletions occur.}, subject = {Biochemie}, language = {en} } @article{HallenbeckDutkaKochaneketal.1988, author = {Hallenbeck, JM and Dutka, AJ and Kochanek, PM and Sir{\´e}n, Anna-Leena and Pezeskpour, GH and Feuerstein, G.}, title = {Stroke risk factors prepare rat brainstem tissues for a modified localized Shwartzman reaction}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47971}, year = {1988}, abstract = {Stroke risk factors such as hypertension, diabetes, advanced age, and genetic predisposition to stroke were demonstrated to prepare rat brainstem tissues for a modified local Shwartzman reaction. A single intracisternal injection of endotoxin provoked the reaction, and affected rats manifested neurologie deficits accompanied by pathologie lesions. Brainstem infarcts developed in only a small proportion of rats without recognized risk factors after intracisternal injection of endotoxin. Thus, stroke risk factors, whieh are ordinarily regarded as operating through acceleration of atherosclerosis, may predispose to brain ischemia by local effects on brain mierocirculation such as those thought to underlie preparation of a tissue for the local Shwartzman reaction.}, subject = {Gehirn}, language = {en} } @inproceedings{KurtzSchneiderBorkowskietal.1988, author = {Kurtz, Beth and Schneider, Wolfgang and Borkowski, John G. and Carr, Martha and Turner, Lisa A.}, title = {Sources of memory and metamemory development: Societal, parental, and educational influences}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-50524}, year = {1988}, abstract = {This project had two goals: (1) to examine the impact of strategy training on memory performance in German and American children, and (2) to search for environmental correlates of individual differences in cognitive processes. Following pretesting, 437 children were divided into training and control groups, with the former receiving training in clustering strategies. Trained children showed sizable strategy maintenance and transfer effects two weeks and six months later. Parents and teachers completed questionnaires about the teaching of strategies and their attributional beliefs about children's academic successes and failures. The differences in strategie behavior and attributions of German and American children were due, in part, to differences in strategy-enriched environments.}, subject = {Psychologie}, language = {en} } @article{UlrichsMuellerRuchholtz1988, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Expression of MHC Structures on Immunologically Reactive and Non Reactive Cells in Islets of Langerhans and Other Tissues}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45557}, year = {1988}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{LiebertSchneiderSchauliesterMeulen1988, author = {Liebert, U. G. and Schneider-Schaulies, Sibylle and ter Meulen, V.}, title = {Measles Virus infections of the central nervous system (CNS) of rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34087}, year = {1988}, abstract = {No abstract available}, subject = {Masernvirus}, language = {en} } @article{SchneiderSchauliesLiebertBaczkoetal.1988, author = {Schneider-Schaulies, Sibylle and Liebert, U. G. and Baczko, K. and ter Meulen, Volker}, title = {Molecular Biological Analyses of Measles Virus Gene Expression in the CNS of Acutely and Persistently Infected Rat Brain Cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34104}, year = {1988}, abstract = {No abstract available}, subject = {Masernvirus}, language = {en} } @article{Hommers1988, author = {Hommers, Wilfried}, title = {Implicit psychological theories in legal thought on sentencing and liability}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47093}, year = {1988}, abstract = {No abstract available}, subject = {Haftung}, language = {en} } @article{KekowUlrichsMuellerRuchholtzetal.1988, author = {Kekow, J{\"o}rn and Ulrichs, Karin and M{\"u}ller-Ruchholtz, Wolfgang and Gross, Wolfgang L.}, title = {Measurement of rat insulin. Enzyme-linked immunosorbent assay with increased sensitivity, high accuracy, and greater practicability than established radioimmunoassay}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45543}, year = {1988}, abstract = {Total immunoreactive insulin (IRI) is conventionally determined by radioimmunoassays. IR! measurement in rats can be made more sensitive, accurate, and practical, as demonstrated by a new modified enzyme-linked immunosorbent assay (ELlSA). It is characterized by indirect binding of an anti-insulin antibody by an antiglobulin antibody and uses the principle of competitive saturation. In this ELlSA, IRI can be determined in a wide range of concentrations, corresponding to the standards. The standard curve ranges from 100 to 0.049 ng/mllRI (1 ng/ml - 23.4 JLU/ml - 172 pM rat insulin). The statistical analysis shows between- and within-assay coefficients of variation of :515\%. Diabetes 37:321-26,1988}, subject = {Chirurgie}, language = {en} } @techreport{Hommers1988, author = {Hommers, Wilfried}, title = {Recompense as Stimulus and Response: Toward an Exchange of Law and Psychology}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-43743}, year = {1988}, abstract = {Recompense denotes a more or less complete undoing of a harm which may combine the tWO aspects: compensation for the victim and the apology of the harmdoer. The present empirical research on recompense started with an analysis of the judgmental structures of recompense in legal thought and law, as such analysis has been neglected in prior research. The obtained results on recompense as stimulus and response reinforce the general idea of the present approach of using the framework of law and legal history in the empirical research of cognitive science. Since the traditionahelationship of jurisprudence and psychology is reversed by that research strategy, law and psychology appear to interact mutually, and a more comprehensive concept of legal psychology is implemented.}, language = {en} } @misc{Hommers1988, author = {Hommers, Wilfried}, title = {Review of "Roskam, E.E., \& Suck, R. (Eds.): Progress in mathematical psychology. Amsterdam: North-Holland, 1987, pp. 538."}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-43525}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{RubtsovOganessyanGorboulevetal.1988, author = {Rubtsov, P. M. and Oganessyan, R. G. and Gorboulev, Valentin G. and Skryabin, K. G. and Bayev, A. A.}, title = {Genetic engineering of peptide hormones : II. Possible polymorphism of preprolactin in cattle. Data of molecular cloning}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-46975}, year = {1988}, abstract = {Primary structure is determined of an insertion of a clone isolated from the library of hypophyseal cDNA of cattle by hybridization with a probe specific for prolactin. Analysis of nucleotide sequences showed that in the process of cloning, reorganization occurred in structure of preprolactin cDNA, including an inversion of the 5'-terminal and deletion of the central section of cDNA. Nevertheless, from structure of cDNA, nucleotide sequences can be deduced of extended 5'- and 3'-terminal sections of preprolactin mRNA in cattle with lengths of 257 and 551 nucleotide residues, respectively. When these sequences are compared to those established previously, some differences were found in primary structure. The most important of them is the presence of an additional codon which codes alanine at the position (-22) of the signal peptide. It is suggested that heterogeneity of preprolactin mRNA of cattle in the section coding the signal peptide is the result of alternative splicing, as was shown for preprolactin mRNA in rats.}, language = {en} } @article{ZvirblisGorboulevRubtsovetal.1988, author = {Zvirblis, G. S. and Gorboulev, Valentin G. and Rubtsov, P. M. and Chernov, B. K. and Golova, Yu. B. and Pozmogova, G. E. and Skryabin, K. G. and Bayev, A. A.}, title = {Genetic engineering of peptide hormones : III. Cloning of cDNA of porcine growth hormone and construction of gene for expression of hormone in bacteria}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-46958}, year = {1988}, abstract = {Results are presented of cloning cDNA of procine growth hormone, analysis of its primary structure, and creation of a construction capable of expression of this cDNA in Esqheriahia coti cells. It is shown that in the population of mRNA coding porcine growth hormone, heterogeneity is noted which is manifested not only at the level of the nucleotide sequence, but also is reflected in the amino acid sequence of the mature hormone.}, language = {en} } @article{KruegerStuckenbergVollrath1988, author = {Kr{\"u}ger, Hans-Peter and Stuckenberg, Annette and Vollrath, Mark}, title = {Stability and Variability in Interactive Behavior as Measured by Methods of "Speech Chronemics"}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40908}, year = {1988}, abstract = {Dyadic interaction is modelled os an adaptive process between personality of the partners involved and the characteristics of the theme. The theme structure and the principles which control the adaptation process are referred to as "syntality". The material of the studies reported are the speech signals of the verbal interaction reduced to an on-off pattern. In a first study individual speech behavior was found to remain stable in dyads even if partners changed. The second study showed the stability of the speech patterns for different interaction themes even if dyads changed. These apparently contradictory results are reconciled by introducing the concept of "adaptive stability". Individual speech behavior does not happen at a stable activity level, but is characterized by a constant relationship (" less" or "more") to the respective activity of the other partner.}, language = {en} } @article{ThiryScheerGoessens1988, author = {Thiry, Marc and Scheer, Ulrich and Goessens, Guy}, title = {Immunoelectron microscopic study of nucleolar DNA during mitosis in Ehrlich tumour cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40745}, year = {1988}, abstract = {In order to investigate the DNA localization within Ehrlich tumor cell nucleoli during mitosis, two recent immunocytochemical methods using either an anti-DNA or an anti-bromodeoxyuridine (BrdU) monoclonal antibody have been applied. In both cases, the immunogold labeling has been performed on ultrathin sections of cells embedded either in Lowicryl K4M or in Epon, respectively. Identical results are observed with both immunocytochemical approaches. In the interphase nucleolus, besides the labeling of the perinucleolar chromatin shell and of its intranucleolar invaginations which penetrate into the nucleolar body and often terminate at the fibrillar centers, a few gold particles are also preferentially found towards the peripheral region of the fibrillar centers. In contrast, the dense fibrillar component and the granular component are never labeled. During mitosis, the fibrillar centers persist at the chromosomal nucleolus organizing regions (NOR's) and can be selectively stained by the silver method. However, these metaphase fibrillar centers are no longer decorated by the DNA- or BrdU antibodies. These results indicate that until the end of prophase, rRNA genes are present inside the fibrillar center material, disappear during metaphase and reappear in reconstituting nucleoli during telophase. Thus, fibrillar centers appear to represent structures sui generis, which are populated by rRNA genes only when the nucleolus is functionally active. In segregated nucleoli after actinomycin D treatment, the DNA labeling is exclusively restricted to the perinucleolar chromatin blocks. These findings also suggest that the DNA content of the fibrillar center material varies according to the rRNA transcription level of the cells. The results are discussed in the light of the present knowledge of the functional organization of the nucleolus.}, subject = {Cytologie}, language = {en} } @article{HughesLillienRaffetal.1988, author = {Hughes, Simon M. and Lillien, Laura E. and Raff, Martin C. and Rohrer, Hermann and Sendtner, Michael}, title = {Ciliary neurotrophic factor induces type-2 astrocyte differentiation in culture}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42660}, year = {1988}, abstract = {We have been studying a population of bipotential glial progenitor cells in the perinatal rat optic nerve and brain in an attempt to understand how cells choose between alternative fates in the developing mammalian central nervous system (CNS). This cell population gives rise initially to oligodendrocytes and then to type-2 astrocytes1 both of which apparently collaborate in sheathing axons in the CNS2,3. In vitro studies suggest that oligodendrocyte differentiation is the constitutive pathway of development for the oligodendrocyte-type-2-astrocyte (O-2A) progenitor cell4,5, whereas type-2 astrocyte differentiation depends on a specific inducing protein6. This protein is present in the developing optic nerve when type-2 astrocytes are differentiating and can induce 0-2A progenitor cells in vitro to express glial fibrillary acidic protein (GFAP)6, a marker of astrocyte differentiation7. Here we show that the type-2-astrocyte-inducing protein is similar or identical to ciliary neutrotrophic factor (CNTF)8,9, which promotes the survival of some types of peripheral neurons in vitro8, including ciliary ganglion neurons8,10. This suggests that CNTF, in addition to its effect on neurons, may be responsible for triggering type-2 astrocyte differentiation in the developing CNS.}, language = {en} } @article{BenaventeReimerRoseetal.1988, author = {Benavente, Ricardo and Reimer, Georg and Rose, Kathleen M. and H{\"u}gle-D{\"o}rr, Barbara and Scheer, Ulrich}, title = {Nucleolar changes after microinjection of antibodies to RNA polymerase I into the nucleus of mammalian cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40666}, year = {1988}, abstract = {After microinjection of antibodies against RNA polymerase I into the nuclei of cultured rat kangaroo (PtKz) and rat (RVF-SMC) cells alterations in nucleolar structure and composition were observed. These were detected by electron microscopy and double-label immunofluorescence microscopy using antibodies to proteins representative of the three major components of the nucleolus. The microinjected antibodies produced a progressive loss of the material of the dense fibrillar component (DFC) from the nucleoli which, at 4 h after injection, were transformed into bodies with purely granular component (GC) structure with attached fibrillar centers (FCs). Concomitantly, numerous extranucleolar aggregates appeared in the nucleoplasm which morphologically resembled fragments of the DFC and contained a protein (fibrillarin) diagnostic for this nucleolar structure. These observations indicate that the topological distribution of the material constituting the DFC can be experimentally influenced in interphase cells, apparently by modulating the transcriptional activity of the rRNA genes. These effects are different from nucleolar lesions induced by inhibitory drugs such as actinomycin D-dependent "nucleolar segregation". The structural alterations induced by antibodies to RNA polymerase I resemble, however, the initial events of nucleolar disintegration during mitotic prophase.}, language = {en} } @article{SendtnerGnahnWakadeetal.1988, author = {Sendtner, Michael and Gnahn, H. and Wakade, A. and Thoenen, Hans}, title = {Is activation of the Na\(^+\)K\(^+\) pump necessary for NGF-mediated neuronal survival?}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42610}, year = {1988}, abstract = {The ability of nerve growth factor to cause rapid activation of the Na+K+ pump of its responsive cells was examined by measuring the uptake of 86Rb+. A significant increase in 86Rb+ uptake in Ea chick dorsal root ganglion sensory neurons after NGF treatment was seen only if the cells had been damaged during the preparation procedure. Such damaged cells could not survive in culture in the presence of NGF, and undamaged cells that did survive in response to NGF exhibited no increased 86Rb+ uptake rate. Furthermore, cultured calf adrenal medullary cells did not show an increase in 86Rb+ uptake after treatment with NGF, although these cells respond to NGF with an increased synthesis of catecholaminergic enzymes. These results are incompatible with the hypothesis that the mechanism of action of NGF that promotes neuronal survival and enzyme induction results from an initial stimulation of the Na+K+ pump.}, language = {en} } @article{ThiryScheerGoessens1988, author = {Thiry, Marc and Scheer, Ulrich and Goessens, Guy}, title = {Localization of DNA within Ehrlich tumour cells nucleoli by immunoelectron microscopy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39327}, year = {1988}, abstract = {The distribution of DNA in Ehrlich tumour cell nucleoli was investigated by means of an immunocytochemical approach , involving a monoclonal antibody directed against double- and single-stranded DNA. Immunolabelling was performed . either before or after the embedding process. The postembedding labelling method allows better ultrastructural preservation than the preembedding labelling method. In particular, the various nucleolar components are well preserved and identifiable. In the nucleolus, labelling is particularly concentrated over the perinucleolar chromatin and over its intranucleolar invaginations, which penetrate the nucleolar body and often terminate at the fibrillar centres. In addition, aggregates of gold particles are found in the fibrillar centres, preferentially towards the peripheral regions. By contrast, the dense fibrillar component is completely devoid of labelling. The results seem to indicate that DNA containing the rDNA genes is located in the fibrillar centres, with a preference for the peripheral regions. This finding suggests that transcription of the rDNA genes should occur within the confines of the fibrillar centre, probably close to the boundary region of the surrounding dense fibrillar component. The results are discussed in the light of present knowledge of the functional organization of the nucleolus.}, language = {en} } @article{BenaventeSchmidtZachmannHuegleDoerretal.1988, author = {Benavente, Ricardo and Schmidt-Zachmann, Marion S. and H{\"u}gle-D{\"o}rr, B. and Reimer, G. and Rose, K. M. and Scheer, Ulrich}, title = {Identification and definition of nucleolus-related fibrillar bodies in micronucleated cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39423}, year = {1988}, abstract = {Small nucleolus-related bodies which occur in the nUcleoplasm of " micronuclei" lacking nucleolar organizers have been studied by immunofluorescence microscopy. These bodies stained specifically with three different antibodies directed against proteins that are normally associated with the dense fibrillar component of functional nucleoli, but not with antibodies specific for certain proteins of the granular component or the fibrillar centers. Our data show that, in the absence of rRNA genes, the various constituent proteins characteristic of the dense fibrillar component spontaneously assemble into spherical entities but that the subsequent fusion of these bodies into larger structures is prevented in these micronuclei. The similarity between these nucleolus-related bodies of micronuclei and the prenucleolar bodies characteristic of early stages of nucleologenesis during mitotic telophase is discussed.}, language = {en} } @inproceedings{SchuesslerOkruschRichteretal.1988, author = {Sch{\"u}ssler, Ulrich and Okrusch, M. and Richter, P. and Seidel, E.}, title = {Geochemistry of metabasites and element mobility}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-38880}, year = {1988}, abstract = {No abstract available}, language = {en} } @inproceedings{SeidelKreuzerSchuessleretal.1988, author = {Seidel, E. and Kreuzer, H. and Sch{\"u}ssler, Ulrich and Okrusch, M. and Lenz, K.-L. and Raschka, H.}, title = {K-Ar geochronology of the East-Bavarian basement}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-38874}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{ReimerRaskaScheeretal.1988, author = {Reimer, Georg and Raska, Ivan and Scheer, Ulrich and Tan, Eng M.}, title = {Immunolocalization of 7-2-ribonucleoprotein in the granular component of the nucleolus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33890}, year = {1988}, abstract = {Certain autoimmune sera contain antibodies against a nucleolar ribonucleoprotein particle associated with 7-2-RNA (R. Reddy et al. (1983) J. Bioi. Chem . 258, 1383; C. Hashimoto and J. A. Steitz (1983) J. Bioi. Chem. 258, 1379). In this study, we showed by immunofluorescence microscopy that antibodies reactive with 7-2-ribonucleoprotein immunolocalized in the granular regions of actinomycin D and 5,6-dichloro-I-j3-D-ribofuranosylbenzimidazole (DRB)-segregated nucleoli from Vero cells. By electron microscopic immunocytochemistry, antigen-antibody complexes were located in the granular component of transcriptionally active nucleoli from rat liver hepatocytes and HeLa cells. Anti-7- 2-RNP antibodies from two autoimmune sera immunoprecipitated a major protein of Mr 40,000 from e5S] methionine-Iabeled HeLa cell extract. The immunolocalization data suggest that 7-2-ribonucleoprotein may be involved in stages of ribosome biogenesis which take place in the granular component of the nucleolus, i.e., assembly, maturation, and/or transport of preribosomes}, language = {en} } @article{RoseSzopaHanetal.1988, author = {Rose, Kathleen M. and Szopa, Jan and Han, Fu-Sheng and Cheng, Yung-Chi and Richter, Arndt and Scheer, Ulrich}, title = {Association of DNA topoisomerase I and RNA polymerase I: A possible role for topoisomerase I in ribosomal gene transcription}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33901}, year = {1988}, abstract = {RNA polymerase I preparations purified from a rat hepatoma contained DNA topoisomerase activity. The DNA topoisomerase associated with the polymerase had an Mr of 110000, required Mg2+ but not ATP, and was recognized by anti-topoisomerase I antibodies. When added to RNA polymerase I preparations containing topoisomerase activity, anti-topoisomerase I antibodies were able to inhibit the DNA relaxing activity of the preparation as well as RNA synthesis in vitro. RNA polymerase II prepared by analogous procedures did not contain topoisomerase activity and was not recognized by the antibodies. The topoisomerase I: polymerase I complex was reversibly dissociated by column chromatography on Sephacryl S200 in the presence of 0.25 M (NH4hS04. Topoisomerase I was immunolocalized in the transcriptionally active ribosomal gene complex containing RNA polymerase I in situ. These data indicate that topoisomerase I and RNA polymerase I are tightly complexed both in vivo and in vitro, and suggest a role for DNA topoisomerase I in the transcription of ribosomal genes.}, language = {en} } @article{ScheerDabauvalleMerkertetal.1988, author = {Scheer, Ulrich and Dabauvalle, Marie-Christine and Merkert, Hilde and Benavente, Ricardo}, title = {The nuclear envelope and the organization of the pore complexes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34275}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{DabauvalleSchulzScheeretal.1988, author = {Dabauvalle, Marie-Christine and Schulz, Barbara and Scheer, Ulrich and Peters, Reiner}, title = {Inhibition of nuclear accumulation of karyophilic proteins in living cells by microinjection of the lectin wheat germ agglutinin}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34288}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{LillienSendtnerRohreretal.1988, author = {Lillien, Laura E. and Sendtner, Michael and Rohrer, Hermann and Hughes, Simon M. and Raff, Martin C.}, title = {Type-2 Astrocyte Development in Rat Brain Cultures is initiated by a CNTF-like protein produced by type-1 astrocytes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31708}, year = {1988}, abstract = {No abstract available}, language = {en} } @inproceedings{KreuzerVejnarSchuessleretal.1988, author = {Kreuzer, Hans and Vejnar, Zdenek and Sch{\"u}ssler, Ulrich and Okrusch, Martin and Seidel, Eberhard}, title = {K-Ar dating in the Tepl{\´a}-Domazlice zone at the western margin of the Bohemian Massif}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31106}, year = {1988}, abstract = {K-Ar dating on hornblendes and micas from the Tepla Domazlice zone revealed a pattern of dates which significantly deviates from the mid-Carboniferous to early Permian one that is found in the adjacent low-pressure metamorphic Moldanubian and Saxothuringian. Especially for the Marianske Lazne metabasic complex, confirming early Czech determinations, the dates resemble the early Devonian pattern determined for the Munchberg Gneiss Massif and the Erbendorf-Vohenstrau zone of northeastern Bavaria. This supports the idea that all three units are remnants of a huge' complex which suffered a metamorphic overprint under medium-pressure conditions, probably in the early Devonian. Strong rejuvenation is found in the southern part of the Tepla-Domazlice zone by which micas and even two hornblendes were reset to mid-Carboniferous ages. According to the geological setting, part of the apparently preDevonian dates may be explained by inherited argon from earlier metamorphic and magmatic events, e.g. the high-pressure metamorphism documented in eciogitic relics. However, excess argon, caused by the mid-Carboniferous overprint cannot be excluded.}, language = {en} } @incollection{Ruhe1988, author = {Ruhe, Ernstpeter}, title = {Comment dater la naissance du roman par lettres en France?}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34147}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{MollMitchell1988, author = {Moll, Heidrun and Mitchell, Graham F.}, title = {Analysis of variables associated with the promotion of resistance, and its abrogation, in T cell-reconstituted nude mice infected with Leishmania major}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30949}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{GeiseLinsenmair1988, author = {Geise, W. and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. IV. Ecological significance of water economy with comments on thermoregulation and energy allocation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30570}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{HegmannChristlPetersetal.1988, author = {Hegmann, Joachim and Christl, Manfred and Peters, Karl and Peters, Eva-Maria and Schnering, Hans Georg}, title = {Conjugated and Nonconjugated Cyclopentenones by a Reaction Cascade from Methyl 6-0xo-5-phenyl-1,3,4-oxadiazine-2-carboxylate and 1,3-Butadienes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30207}, year = {1988}, abstract = {No abstract available}, language = {en} }