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1.
Hoch Brigitte Lutsch Gudrun Schlegel Wolfgang-Peter Stahl Joachim Wallukat Gerd Bartel Sabine Krause Ernst-Georg Benndorf Rainer Karczewski Peter 《Molecular and cellular biochemistry》1996,160(1):231-239
Recent investigations concentrate on the correlation between the myocardial expression of the inducible 70-kDa heat shock protein (HSP70i) by different stress conditions and its possible protective effects. Only few studies have focused on the involvement of small heat shock proteins in this process. We analyzed the location of the small heat shock protein HSP25 in isolated cardiomyocytes as well as its location and induction in isolated perfused hearts of rats. By immunofluorescence microscopy HSP25 was found to colocalize with actin in the I-band of myofibrils in cardiomyocytes of isolated perfused hearts as well as in isolated neonatal and adult cardiomyocytes. Hyperthermic perfusion of isolated hearts for 45 min resulted in modulation of different parameters of heart function and in induction of HSP25 and HSP70i. Temperatures higher than 43°C (44–46°C) were lethal with respect to the contractile function of the hearts. Compared to control hearts perfused at 37°C, significant increases during hyperthermic perfusion at 42°C and 43°C were obtained for heart rate, contraction velocity and relaxation velocity. In response to hyperthermia at 43°C and after subsequent normothermic perfusion for 135 min at 37°C, left ventricular pressure, contraction velocity and relaxation velocity remained significantly elevated. However, heart rate returned to control values immediately after the period of heat treatment. HSP25 is constitutively expressed even in normothermic perfused hearts as shown by Western blotting. Hyperthermia increased the content of HSP25 only in the left ventricular tissue. In contrast, HSP70i was strongly induced in all analyzed parts of the myocardium (left ventricle, right ventricle, septum). Our findings suggest a differential regulation of HSP25 and HSP70i expression in response to hyperthermia in isolated perfused hearts. The constitutively expressed HSP25 seems to be located adjacent to the myofibrils which implies a specific role of this protein even under unstressed conditions for the contractile function of the myocardium. 相似文献
2.
Sabine Kölle Fred Sinowatz Gudrun Boie Ines Totzauer Werner Amselgruber Johnna Plendl 《The Histochemical journal》1996,28(6):441-447
Summary The mRNA of the zona pellucida glycoprotein ZP3 was localized in frozen sections of pig ovaries, isolated oocytes and early embryos byin situ hybridization using biotinylated oligonucleotide probes. In follicles, the distribution of mRNA for ZP3 was correlated with the developmental stage: in primordial and primary follicles, the mRNA was shown to be predominantly localized in the oocyte. In secondary follicles, mRNA was found in both the oocyte and follicle cells. In tertiary and preovulatory follicles, the follicle cells showed distinct staining, whereas the oocyte was labelled weakly. In the early embryo, i.e. 2 days after fertilization, mRNA for ZP3 could not be demonstrated. Our results suggest that, in the pig, the zona pellucida protein ZP3 is synthesized by the oocyte and the follicle cells in sequence. After fertilization, synthesis of ZP3 is terminated. 相似文献
3.
Mimicking a Honeybee Queen?Vespa affinis indosinensis Pérez 1910 Hunts Drones of Apis cerana F. 1793
Nikolaus Koeniger Gudrun Koeniger Makhdzir Mardan 《Ethology : formerly Zeitschrift fur Tierpsychologie》1994,98(2):149-153
Hornets (Vespa affinis) flying in a drone congregation area attracted drones of Apis cerana. The drones followed the hornet and were ‘manoeuvred’ towards a leaf or a tree. The hornet then rushed at one of the drones. Many attempts by the hornet to catch a drone were unsuccessful and all drones fled. After failing, the hornet returned to centre of the drone congregation area and repeated the behaviour. Only after successfully seizing of a drone did the hornet leave the drone congregation area carrying its prey. In a two-choice test in the centre of the drone congregation area, free-flying A. cerana drones preferred a hornet model to a live A. cerana queen. V. affinis apparently ‘exploits’ the intraspecific communication between queen and drones of A. cerana. Hunting of drones in the drone congregation area by V. affinis may be an example of predatory mimicry. 相似文献
4.
Gudrun Borchert Sabine Bartel Inge Beyerdörfer Irmgard Küttner Laszlo Szekeres Ernst-Georg Krause 《Molecular and cellular biochemistry》1994,132(1):57-67
Evidence is accumulating that 7-oxo-prostacyclin (7-oxo-PGI2) induces a delayed indirect anti-adrenergic and cytoprotective effect on the myocardium, the mechanism of which is still unclear. To demonstrate that a single application of 7-oxo-PGI2 (50 g/kg i.m.) 48 h prior to starting experiments attenuates the isoprenaline inducible inotropic response and accumulation of cAMP, isolated hearts of pretreated animals were perfused in the Langendorff mode with and without isoprenaline (1 to 100 nM). The late anti-adrenergic effect of the drug was manifested by a significant attenuation in the elevation of cAMP levels as well as in contractile force development. This effect was not due to changes in cAMP generation as there were identical 1-adrenoceptor densities and affinities (as calculated from [3H]-CGP binding studies), Gi and Gs protein patterns (as taken from Western blots) as well as adenylyl cyclase activity measurements in the hearts studied. The anti-adrenergic potency of 7-oxo-PGI2, however, was found to be related to a significant rise in cyclic nucleotide hydrolysis by phosphodiesterase (PDE). Using the fast-performance liquid chromatographic separation for PDE isoforms, a significant increase in the activity of PDE isoforms I and IV (260±28 vs 110±12 pmol cGMP/min x enzyme fraction and 77±11 vs 34±3 pmol cAMP/min x enzyme fraction, respectively) was found in the solubilized fraction of cardiac membranes in comparison to untreated controls; PDE IV activity was also increased in the cytosolic fraction (106±14 vs 65±6 pmol cAMP/min x enzyme fraction). The hypothesis that the delayed anti-adrenergic effect of 7-oxo-PGI2 is initiated by an induction and accelerated synthesis of PDE I and IV in the heart is underlined by the fact that cycloheximide suppresses completely both the rise in PDE activities and the anti-adrenergic effects studied. It is suggested that an inducible predominance of cAMP degradation over its generation may be of relevance in processes related to heart protection. 相似文献
5.
Hans-Peter Baum J?rg Reichrath Andrea Theobald Gudrun Schock 《The Histochemical journal》1994,26(12):929-933
Summary In contrast to that in paraffin-embedded tissue, the reactivity of monoclonal PCNA antibody PC10 on cryostat sections requires
a special fixation procedure as the target epitope is seemingly not accessible to its antibody. A panel of 18 fixation protocols
was investigated. Chilled methanol or acetone, or PLP (paraformaldehyde-lysine-periodate) was found to be unsuitable for skin
preparations. A two-step fixation protocol was developed for normal skin and basal cell carcinomas. They were fixed first
in 3.4% buffered formaldehyde, followed by fixation in 2:1 v/v ethanol-acetic acid. Following this fixation regime, cryostat
sections displayed the same PCNA/PC10 labelling pattern as paraffin sections of formalin-fixed tissue. 相似文献
6.
A male patient carrying an interstitial deletion in Xp22.3 and affected by Kallmann syndrome, X-linked ichthyosis and mental retardation, but without chondrodysplasia punctata or short stature, was investigated with molecular probes from the distal Xp22.3 region. By means of a novel probe, M115, from the relevant region, the distal deletion breakpoint was shown to be between 3.18 and 3.57 Mb from Xptel. As the patient is not affected by X-linked recessive chondrodysplasia punctata, the gene for this disease can therefore be located to within an interval of less than one megabase proximal to the pseudoautosomal boundary. If the chondrodysplasia punctata gene is associated with a CpG island, this leaves only two islands at 2760 and 3180 kb from the Xp telomere as the most promising candidate sites for this gene. 相似文献
7.
Gudrun Hilgerloh 《Journal of Ornithology》1993,134(4):447-452
Zusammenfassung Die Hypothese, daß der Atlantik zwischen NW-Afrika und der Südküste der Iberischen Halbinsel auf dem Frühjahrszug von Transsaharaziehern nur bei E-Winden infolge von Drift oder Pseudodrift überquert wird, wurde geprüft. An der Fangstation von Sanlucar de Barrameda an der spanischen Südküste wurden 1983 und 1986 maximale Fangzahlen von Transsaharaziehern in Zeiten erreicht, in denen mehrere Tage hintereinander östliche Winde am Boden und in der Höhe herrschten.
Is the Atlantic between NW Africa and Spain crossed by passerine trans-Saharan migrants in spring?
Summary The hypothesis is tested whether the Atlantic between NW Africa and the south coast of the Iberian Peninsula is crossed in spring by passerine trans-Saharan migrants only in easterly winds because of drift or pseudodrift. The analysis is based on the number of daily captured birds during spring migration 1983 and 1986 at a ringing station in Sanlucar de Barrameda, situated at the Spanish south coast. Maximum numbers of captured birds occured only during periods of several days with easterly winds at the bottom and high.相似文献
8.
Brian A. Hollander Champakali Ayyub Gerry Shaw Gudrun S. Bennett 《Journal of neurochemistry》1993,61(6):2115-2123
Although neurofilaments are among the most highly phosphorylated proteins extant, relatively little is known about the kinases involved in their phosphorylation. The majority of the phosphates present on the two higher-molecular-mass neurofilament subunits are added to multiply repeated sequence motifs in the tail. We have examined the specificity of a neurofilament-associated kinase (NFAK) partially purified from chicken spinal cord that selectively phosphorylates the middle-molecular-mass neurofilament subunit, NF-M. Two-dimensional phosphopeptide mapping of 32P-labeled NF-M shows that, in vitro, NFAK phosphorylates a subset of peptides phosphorylated in vivo in cultured neurons. The absence of a complete complement of labeled phosphopeptides following in vitro phosphorylation, compared with phosphorylation in vivo, is not due to a lack of availability of phosphorylation sites because the same maps are obtained when enzymatically dephosphorylated NF-M is used as an in vitro substrate. Phosphopeptide maps from in vitro-phosphorylated NF-M and those from a recombinant fusion protein containing only a segment of the tail piece of chicken NF-M reveal identical labeled peptides. The fusion protein lacks a segment containing 17 KXX(S/T)P putative phosphorylation sites contained in the tail of chicken NF-M but contains a segment that includes four KSPs and a KSD site also present in the intact tail. These results suggest (a) that NFAK mediates the phosphorylation of some, but not all, potential phosphorylation sites within the tail of NF-M and (b) that multiple kinases are necessary for complete phosphorylation of the NF-M tail. 相似文献
9.
10.
Gudrun Ljunger Patrick Adlercreutz Bo Mattiasson 《Biocatalysis and Biotransformation》1993,7(4):279-288
-Chymotrypsin was modified with cyanuric chloride activated monomethoxypolyethylene glycol (MPEG) with molecular weights 1900 and 5000. Using the higher molecular weight MPEG a product that was soluble in benzene at moderate levels of modification was obtained, whereas with MPEG 1900 almost all the enzyme's amino groups had to be modified for dissolving the conjugate. The catalytic activity decreased with increasing degree of substitution. Apparent Vmax was considerably higher for the less modified enzyme preparation than for the more modified one, while Km,app stayed almost constant. The modified enzyme was used for peptide synthesis. The reaction was dependent on the content of dissolved water. Both Vmax,app and Km,app increased with increasing water content. It was possible to achieve a process with complete conversion of substrate to dipeptide. 相似文献