Pressure-Induced Alterations in the Protein Pattern of the Thermophilic Archaebacterium Methanococcus thermolithotrophicus

Elevated hydrostatic pressure has been shown to affect the growth rate of the thermophilic methanobacterium Methanococcus thermolithotrophicus without extending its temperature range of viability. Analysis of the cell inventory after approximately 10 h of incubation at 65 degrees C and 50 MPa (applying high-pressure liquid chromatography and two-dimensional gel electrophoresis) proved that pressure induces alterations in the protein pattern and the amino acid composition of the total cell hydrolysate. Gels showed that after pressurization a series of (basic) proteins with a molecular mass in the range of 38 and 70 kilodaltons occurs which is not detectable in cells grown at normal atmospheric pressure. The question of whether the observed alterations are caused by the perturbation of the balance of protein synthesis and turnover or by the pressure-induced synthesis of compounds analogous to heat shock proteins remains unanswered

Rezensionen

Rezensionen zu folgenden Titeln: 1) Eirmbter-Stolbrink, Eva; König-Fuchs, Claudia: Erziehungswissenschaftliche Methodenforschung: Vermittlung und Aneignung von Wissen. Reinbek: Lau 2012. ISBN 978-3941400405. 2) Fahrenwald, Claudia: Erzählen im Kontext neuer Lernkulturen. Eine bildungstheoretische Analyse im Spannungsverhältnis von Wissen, Lernen und Subjekt. Wiesbaden: VS Verl. f. Sozialwiss. 2001. ISBN 978-3-531-18385-5. 3) Kerres, Michael: Mediendidaktik. Konzeption und Entwicklung mediengestützter Lernangebote. München: Oldenbourg 2012 (3., vollst. überarb. Aufl.). ISBN 978-3-486-27207-9. 4) Schmidt-Lauff, Sabine (Hg.): Zeit und Bildung: Annäherung an eine zeittheoretische Grundlegung. Münster: Waxmann 2012. ISBN 978-3-8309-2660-3. 5) Uhmann, Christine: Aktuelle Herausforderungen im Management von Weiterbildungsorganisationen. Hannover: ArtSet/EXPRESSUM-Verl. 2011. ISBN 978-3-89069-026-1

SOX5 is involved in balanced MITF regulation in human melanoma cells

Background: Melanoma is a cancer with rising incidence and new therapeutics are needed. For this, it is necessary to understand the molecular mechanisms of melanoma development and progression. Melanoma differs from other cancers by its ability to produce the pigment melanin via melanogenesis; this biosynthesis is essentially regulated by microphthalmia-associated transcription factor (MITF). MITF regulates various processes such as cell cycling and differentiation. MITF shows an ambivalent role, since high levels inhibit cell proliferation and low levels promote invasion. Hence, well-balanced MITF homeostasis is important for the progression and spread of melanoma. Therefore, it is difficult to use MITF itself for targeted therapy, but elucidating its complex regulation may lead to a promising melanoma-cell specific therapy. Method: We systematically analyzed the regulation of MITF with a novel established transcription factor based gene regulatory network model. Starting from comparative transcriptomics analysis using data from cells originating from nine different tumors and a melanoma cell dataset, we predicted the transcriptional regulators of MITF employing ChIP binding information from a comprehensive set of databases. The most striking regulators were experimentally validated by functional assays and an MITF-promoter reporter assay. Finally, we analyzed the impact of the expression of the identified regulators on clinically relevant parameters of melanoma, i.e. the thickness of primary tumors and patient overall survival. Results: Our model predictions identified SOX10 and SOX5 as regulators of MITF. We experimentally confirmed the role of the already well-known regulator SOX10. Additionally, we found that SOX5 knockdown led to MITF up-regulation in melanoma cells, while double knockdown with SOX10 showed a rescue effect; both effects were validated by reporter assays. Regarding clinical samples, SOX5 expression was distinctively up-regulated in metastatic compared to primary melanoma. In contrast, survival analysis of melanoma patients with predominantly metastatic disease revealed that low SOX5 levels were associated with a poor prognosis. Conclusion: MITF regulation by SOX5 has been shown only in murine cells, but not yet in human melanoma cells. SOX5 has a strong inhibitory effect on MITF expression and seems to have a decisive clinical impact on melanoma during tumor progression

Confirmation of siderazot, Fe3N1.33, the only terrestrial nitride mineral

Siderazot, the only terrestrial nitride mineral, was reported only once in 1876 to occur as coating on volcanic rocks in a fumarolic environment from Mt. Etna and, to date, has been neither confirmed nor structurally characterized. We have studied the holotype sample from the Natural History Museum, London, UK, originally collected by O. Silvestri in 1874, and present siderazot with epsilon-Fe3N-type crystal structure and composition of Fe3N1.33(7) according to crystal structure Rietveld refinements, in good agreement with electron microprobe analyses. Crystal structure data, chemical composition, and Raman and reflectance measurements are reported. Possible formation conditions are derived from composition and phase stability data according to synthetic samples

Saranapal - Urbild des lasterhaften orientalischen Despoten: Entstehung, Bedeutung für die griechisch-römische Welt und Nachwirkung

Auf den ersten Blick mag es überraschend erscheinen, dass für die Griechen nicht Xerxes, der ihre Freiheit ernsthaft bedrohte, zum Prototyp des orientalischen Despoten wurde. Vielmehr wird er bei Aischylos fast als ein Opfer göttlicher Verblendung, sein Misserfolg allenfalls als Strafe für seinen hybriden Ehrgeiz hingestellt