Silke Glage

Publications (22) View all

• Article: Treatment of male mice with gonadotropins to improve the fertilization rate and reproduction.

  S Glage, I Wittur, C Elfers, H J Hedrich, M Dorsch
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  ABSTRACT: The possibility of modifying the genome in mice has led to an exponential increase in the number of strains that have been developed for biomedical research. This will continue during the next few decades because international programmes plan to develop genetically-modified strains for every known mouse gene. Due to our own experiences and that of colleagues we know that the reproductive performance of many of these modified stains is impeded, despite that the modification is independent from genes that control reproduction. In some cases the spermatogenesis might be disturbed. The reason presumably lies in a defective endocrine function of the testes. This can cause reduced and/or abnormal sperm production. In livestock as well as in humans these disorders can be treated with gonadotropins. One treatment period lasts for the duration of spermatogenesis of the respective species. Up to now, nothing is known about such treatments in laboratory mice to restore or increase reproduction of genetically-modified strains. Spermatogenesis in the mouse lasts approximately 35 days. Therefore, we treated sexually mature male mice of C57BL/6 and BALB/c strains with gonadotropins for this period. The aim of this study was to test the principle suitability of such treatment for the improvement of sperm count, sperm motility, fertilization ability and reproduction.
  Laboratory Animals 12/2012; · 1.21 Impact Factor
• Article: A safety and toxicity assessment of the administration of multiple intracerebral injections of irinotecan or doxorubicin drug-eluting beads.

  N Held, A L Lewis, H J Hedrich, T Brinker, S Glage
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  ABSTRACT: OBJECTIVE Previous research in a rat glioma model has shown that the local intratumoral application of polymerbased drug-eluting beads (DEBs) loaded with doxorubicin or irinotecan suppress tumour growth and prolong survival. For translation into a clinical setting, the present experiment investigates in the healthy cat brain the local and systemic toxicity of a multiple injection shot technique. METHODS Three injection shots were placed, each at a 1 cm distance in the frontal lobe. The DEBs were suspended in an aqueous alginate excipient solution, which becomes subject to a sol-gel transition when injected into the Ca(2+)- rich brain tissue environment. Systemic and local side effects were monitored over a period of two weeks. Injection sites were histologically investigated. RESULTS Gelling of the alginate results in the permanent immobilisation of the microspheres at the implantation site. A distinct local cytotoxic effect of doxorubicin was found with intracerebral and intraventricular haemorrhages, and signs of brain tissue necrosis. In cats injected with irinotecan DEBs, such local adverse side effects did not occur. No signs of systemic toxicity were found with both chemotherapeutics. DISCUSSION We conclude that the multiple injection shot technique with irinotecan DEBs meets feasibility criteria and safety requirements for a clinical application.
  Clinical and Translational Oncology 10/2011; 13(10):742-6. · 1.33 Impact Factor
• Source

  Available from: Michael Rothe

  Article: Epidermal growth factor improves lentivirus vector gene transfer into primary mouse hepatocytes.

  M Rothe, I Rittelmeyer, M Iken, U Rüdrich, A Schambach, S Glage, M P Manns, C Baum, M Bock, M Ott, U Modlich
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  ABSTRACT: Partial resistance of primary mouse hepatocytes to lentiviral (LV) vector transduction poses a challenge for ex vivo gene therapy protocols in models of monogenetic liver disease. We thus sought to optimize ex vivo LV gene transfer while preserving the hepatocyte integrity for subsequent transplantation into recipient animals. We found that culture media supplemented with epidermal growth factor (EGF) and, to a lesser extent, hepatocyte growth factor (HGF) markedly improved transduction efficacy at various multiplicities of infection. Up to 87% of primary hepatocytes were transduced in the presence of 10 ng EGF, compared with ~30% in standard culture medium (SCMs). The increased number of transgene-expressing cells correlated with increased nuclear import and more integrated pro-viral copies per cell. Higher LV transduction efficacy was not associated with proliferation, as transduction capacity of gammaretroviral vectors remained low (<1%). Finally, we developed an LV transduction protocol for short-term (maximum 24 h) adherent hepatocyte cultures. LV-transduced hepatocytes showed liver repopulation capacities similar to freshly isolated hepatocytes in alb-uPA mouse recipients. Our findings highlight the importance of EGF for efficient LV transduction of primary hepatocytes in culture and should facilitate studies of LV gene transfer in mouse models of monogenetic liver disease.
  Gene therapy 08/2011; 19(4):425-34. · 4.75 Impact Factor
• Article: Evaluation of biocompatibility and anti-glioma efficacy of doxorubicin and irinotecan drug-eluting bead suspensions in alginate.

  Silke Glage, Andrew L Lewis, Patricia Mertens, Steffen Baltes, Peter Geigle, Thomas Brinker
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  ABSTRACT: Chemotherapeutic drug-eluting beads (DEBs) are microspheres that are in clinical use for intraarterial chemoembolisation of liver cancer. Here we report on the biocompatibility and anti-tumour efficacy of DEBs after intratumoral application in a rat BT4Ca glioma model. Doxorubicin and irinotecan-eluting DEBs were suspended in a Ca(2+)-free aqueous alginate solution that provides a sol-gel transition when injected into the Ca(2+) rich brain tissue. In this way the DEBs are immobilised at the implantation site. Forced elution studies in vitro using a USP-4 flow-through apparatus demonstrated that the alginate excipient helped to reduce the burst effect and rate the elution from the beads. From the in vivo evaluation, doxorubicin DEBs demonstrated a significant local toxicity, while irinotecan-loaded DEBs showed good local tissue compatibility. Doxorubicin at higher concentrations and irinotecan-loaded DEBs were found to decrease tumour volume, increase survival time and decrease the Ki67 proliferation index of the tumour. Doxorubicin was shown by fluorescent microscopy to diffuse into the peritumoral tissue, but also penetrates along white matter tracts, to more distant areas. We conclude that the alginate suspension of irinotecan DEBs can be considered safe and effective in a clinical setting.
  Clinical and Translational Oncology 01/2012; 14(1):50-9. · 1.33 Impact Factor
• Article: Loss of Dnd1 facilitates the cultivation of genital ridge-derived rat embryonic germ cells.

  Emily Northrup, Regina Eisenblätter, Silke Glage, Cornelia Rudolph, Martina Dorsch, Brigitte Schlegelberger, Hans-Jürgen Hedrich, Nils-Holger Zschemisch
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  ABSTRACT: Pluripotent cells referred to as embryonic germ cells (EGCs) can be derived from the embryonic precursors of the mature gametes: the primordial germ cells (PGCs). A homozygous mutation (ter) of the dead-end homolog 1 gene (Dnd1) in the rat causes gonadal teratocarcinogenesis and sterility due to neoplastic transformation and loss of germ cells. We mated heterozygous ter/+ WKY-Dnd1(ter)/Ztm rats and were able to cultivate the first genital ridge-derived EGCs of the rat embryo at day 14.5 post coitum (pc). Genotyping revealed that ten EGC lines were Dnd1 deficient, while only one wild type cell line had survived in culture. This suggests that the inactivation of the putative tumor suppressor gene Dnd1 facilitates the immortalization of late EGCs in vitro. Injection of the wild type EGCs into blastocysts resulted in the first germ-line competent chimeras. These new pluripotent rat EGCs offer an innovative approach for studies on germ cell tumor development as well as a new tool for genetic manipulations in rats.
  Experimental Cell Research 08/2011; 317(13):1885-94. · 3.58 Impact Factor