TY - JOUR A1 - Maueler, W. A1 - Eigenbrodt, E. A1 - Schartl, Manfred T1 - Intermediary metabolism of normal and tumorous tissue of Xiphophorus (Teleostei: Poeciliidae) N2 - No abstract available KW - Physiologische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61855 ER - TY - JOUR A1 - Barnekow, A. A1 - Schartl, Manfred T1 - Comparative studies on the src proto-oncogene and its gene product pp60\(^{c-src}\) in normal and neoplastic tissues of lower vertebrates N2 - No abstract available KW - Physiologische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61869 ER - TY - JOUR A1 - Stopper, Helga A1 - Jones, H. A1 - Zimmermann, U. T1 - Large scale transfection of mouse L-cells by electropermeabilization N2 - Mouse L-cells were transfected by electropenneabilization using the selectable plasmid pSV2-neo which confers resistance to G-418 (Geneticin). 1be DNA concentration used was 1 l'gfml, the field strength was 10 kV fcm, the duration of the pulse was S ~s. Transfeetion yield was optimal at a temperature of 4°C when using a time in between consecutive pulses of 1 minute compared to shorter (of the order of seoonds) or Ionger (3 minutes) time intervals. A more detailed study of the relationship between the number of pulses applied (up to 10) and transfection yield showed it to be almost linear in this range at 4 o C. The yield of transfectants in response to 10 pulses was up to 1000 per 106 cells (using 3.3 pg DNA per cell). The inßuence of the growth phase of the cells on the transfection yield and I or the subpopulation of the mouse L--ceU line used was shown. Furthennore the clone yield depended on the DNA per ceU ratio within a very small range. KW - Toxikologie KW - Electrical breakdown KW - Electropermeabilization KW - Volume distribution KW - Gene transfer KW - Transfection KW - (Mouse L-cell) Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63497 ER - TY - JOUR A1 - Holler, E. A1 - Fischer, H. A1 - Weber, C. A1 - Stopper, Helga A1 - Steger, H. A1 - Simek, H. T1 - A DNA polymerase with unusual properties from the slime mold Physarum polycephalum N2 - Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase cx on phosphocellulose and from each other on heparin-Sepharose. Form HS1 enzymewas 30-40% pure and form HS2 enzyme 60% with regard toprotein contents of the preparations. Form HS2 enzymewas generated from form HS1 enzyme on prolonged standing of enzyme preparations. The DNA polymerases were obtained as complexes of a 60-kDa protein associated with either a 135-kDa (HS1) or a 110-kDa (HS2) DNA-polymerizing polypeptidein a 1:1 molar stoichiometry. The biochemical function of the 60-kDa protein remained unknown. The complexes tended to dissociate during gradient centrifugation and during partition chromatography as weil as during polyacrylamide gradient gel electrophoresis under nondenaturing conditions at high dilutions of samples. Both forms existed in plasmodia extracts, their proportions depending on several factors including those which promoted proteolysis. The DNA polymerases resembled eucaryotic DNA polymerase ß by several criteria and were functionally indistinguishable from each other. It is suggested that lower eucaryotes contain repair DNA polymerases, which are similar to those of eubacteria on a molecular mass basis. KW - Toxikologie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63501 ER - TY - JOUR A1 - Zimmermann, U. A1 - Stopper, Helga T1 - Elektrofusion und Elektropermeabilisierung von Zellen : Eine neuartige Methode der Biotechnologie zur gezieltenVeränderung der genetischen Eigenschaften von Zellen N2 - No abstract available KW - Toxikologie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63514 ER - TY - JOUR A1 - Schneider-Schaulies, Jürgen A1 - Schimpl, A. A1 - Wecker, E. T1 - Kinetics of cellular oncogene expression in mouse lymphocytes II. Regulation of c-fos and c-myc gene expression N2 - Newly isolated lymphocytes from mousespleensexpress the c-fos oncogene even in the absence of mitogen with maximal mRNA levels 60 min post preparation of single cell suspension, whereas c-myc mRNA Ievels increase only after mitogenic Stimulation with maximal mRNA Ievels 6 h post Stimulation. The half-lives of c-fos mRNA are generally very short; they increase from 14 min (after 30 min of culture) to 70 min (after 2 h of culture). The half-lives of c-myc mRNA decrease from 50 min (at 2 and 6 h post stimulation with concanavalin A) to 12 min (at 48 h post stimulation). The c-fos gene transcription is already tumed on in time-0 lymphocytes 10 min after disruption of the organ structure of the spleens and is down-regulated after 2 h and later. In nuclear run-on experiments with nonstimulated lymphocytes there is already significant transcription of the first exon of c-myc, but almost no elongation of the transcript to exon 2 and 3. In concanavalin A-treated lymphocytes elongation is stimulated about 5-fold within 6 h and returns to background levels at 48 h post Stimulation. · The nuclear run-on analyses of nonactivated lymphocytes showed a signal for RNA complementary to c-myc mRNA detected with a probe specific for the exon 1/intron 1 boundary of c-myc, which disappeared with increasing time of concanavalin A Stimulation. This anti-sense transcription may play a role in regulating the elongation of cmyc transcripts. KW - Lymphozyt Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54823 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. A1 - Davidson, E.R. T1 - Calculation of hyperfine coupling constants : An ab initio MRD-CI study for nitrogen to analyse the effects of the basis sets and CI parameter N2 - The hyperfine coupling constant for the nitrogen atom is evaluated by large-scale MRD-CI calculations. A detailed analysis of the charge density at the nucleus and the spin polarization in the ls and 2s shell as a function of various technical parameters is undertaken. Various (s, p) AO basis sets and the inftuence of correlation orbitals is investigated as weil as selection threshold and other properlies in CI calculations. The best value, obtained for the isotropic hyperfine coupling constant in an s, p, d basis, based on theoretical judgment of' best' quantities, is 9·9 MHz compared to 10·4509 MHz. KW - Organische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58784 ER - TY - JOUR A1 - Hacker, Jörg A1 - Ulmer, E. A1 - Fasske, E. A1 - Schmidt, G. T1 - Isolation and characterization of coliphage Omega18A specific for Escherichia coli O18ac strains N2 - The bactedophage Q18A, specific for Escherichia coli 018ac srrains, was isolated frorn sewage. The results of host range and conjugation experiments showed that the sensitivity of bacteria to the phage is associated with rhe presence of 018ac antigens. With sorne of rhe 018 strains rhe phage Q18A produces clear Iysis on bacterial lawns only when applied at a high multiplicity and moreover the phage does not multiply. With rhe help of the phage Ql8A, E. coli 0 18ac strains could be divided inro rwo serologically clistinct subgroups called 018A and 018A1• E. coli strains belanging to the sugroup 0 ISAare sensitive to phage Q t8A wheteas bacteria of subgroup A1 are resistanr. N2 - Der Bakteriophage Q18A, der spezifisch Escherichia coli 018ac Bakterien lysierr, wurde aus Abwasser isoliert. Die Untersuchungen des Wirtsbereichs und Konjugationsversuche zeigten, daß die Sensitivität der Bakterien gegenüber dem Phagen mit dem Vorhandensein des 0 '18ac Antigens assoziiert ist. Bei eir1igen 0 18 Stämmen wird nur bei Anwendung hoher Phagenkonzentrationen eine klare Lysis auf dem Bakterienrasen erzeugt. Darüber hinaus läßt sich der Phage auf diesen Stämmen nicht vermehren. Mit Hilfe des Phagen Q l8A konnten E, wli 0 18ac Stämme in zwei serologische Subgruppen unteneilt werden, die als 0 lHA und 0 l8A 1 bezeichnet werden. E. coli Bakterien der Subgruppe 0 ISA sind gegenüber dem Phagen Ql8A sensitiv und diejenigen der Subgruppe 0 18A 1 sind resistent. KW - Escherichia coli Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73001 ER - TY - JOUR A1 - Feuerstein, G. A1 - Leader, P. A1 - Sirén, Anna-Leena A1 - Braquet, P. T1 - Protective effect of PAF-acether antagonist, BN 52021, in trichothecen toxicosis N2 - Trichothecenes are mycotoxins which produce Iethai toxicosis in humans and animals, yet no adequate therapeutic regimen has been developed. This study provides evidence that the selective platelet activating factor (PAF) antagonist, BN 52021 (5-15 mg/kg i.v.) can prolong the survival of conscious rats exposed to a highly Iethai T -2 toxicosis. These data also suggest that P AF is an important mediator of this unique toxicosis. KW - Neurobiologie KW - T-2 toxin KW - mycotoxin KW - PAF-acether KW - BN 52021 KW - rat Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63244 ER - TY - JOUR A1 - Labroo, V. M. A1 - Cohen, L. A. A1 - Lozovsky, D. A1 - Sirén, Anna-Leena A1 - Feuerstein, G. T1 - Dissociation of the cardiovascular and prolactin-releasing activities of TRH by histidine replacement N2 - No abstract available KW - Neurobiologie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63253 ER -