Elke Leipnitz
Dresden University of Technology
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Featured researches published by Elke Leipnitz.
PLOS ONE | 2014
Ortrud Uckermann; Roberta Galli; Sandra Tamosaityte; Elke Leipnitz; Kathrin Geiger; Gabriele Schackert; Edmund Koch; Gerald Steiner
Background Coherent anti-Stokes Raman scattering (CARS) microscopy provides fine resolution imaging and displays morphochemical properties of unstained tissue. Here, we evaluated this technique to delineate and identify brain tumors. Methods Different human tumors (glioblastoma, brain metastases of melanoma and breast cancer) were induced in an orthotopic mouse model. Cryosections were investigated by CARS imaging tuned to probe C-H molecular vibrations, thereby addressing the lipid content of the sample. Raman microspectroscopy was used as reference. Histopathology provided information about the tumors localization, cell proliferation and vascularization. Results The morphochemical contrast of CARS images enabled identifying brain tumors irrespective of the tumor type and properties: All tumors were characterized by a lower CARS signal intensity than the normal parenchyma. On this basis, tumor borders and infiltrations could be identified with cellular resolution. Quantitative analysis revealed that the tumor-related reduction of CARS signal intensity was more pronounced in glioblastoma than in metastases. Raman spectroscopy enabled relating the CARS intensity variation to the decline of total lipid content in the tumors. The analysis of the immunohistochemical stainings revealed no correlation between tumor-induced cytological changes and the extent of CARS signal intensity reductions. The results were confirmed on samples of human glioblastoma. Conclusions CARS imaging enables label-free, rapid and objective identification of primary and secondary brain tumors. Therefore, it is a potential tool for diagnostic neuropathology as well as for intraoperative tumor delineation.
PLOS ONE | 2013
Allison L. Stelling; Deirdre Toher; Ortrud Uckermann; Jelena Tavkin; Elke Leipnitz; Julia Schweizer; Holger Cramm; Gerald Steiner; Kathrin Geiger
In this work, the infrared (IR) spectra of living neural cells in suspension, native brain tissue, and native brain tumor tissue were investigated. Methods were developed to overcome the strong IR signal of liquid water so that the signal from the cellular biochemicals could be seen. Measurements could be performed during surgeries, within minutes after resection. Comparison between normal tissue, different cell lineages in suspension, and tumors allowed preliminary assignments of IR bands to be made. The most dramatic difference between tissues and cells was found to be in weaker IR absorbances usually assigned to the triple helix of collagens. Triple helix domains are common in larger structural proteins, and are typically found in the extracellular matrix (ECM) of tissues. An algorithm to correct offsets and calculate the band heights and positions of these bands was developed, so the variance between identical measurements could be assessed. The initial results indicate the triple helix signal is surprisingly consistent between different individuals, and is altered in tumor tissues. Taken together, these preliminary investigations indicate this triple helix signal may be a reliable biomarker for a tumor-like microenvironment. Thus, this signal has potential to aid in the intra-operational delineation of brain tumor borders.
PLOS ONE | 2015
Sandra Tamosaityte; Roberta Galli; Ortrud Uckermann; Kerim H. Sitoci-Ficici; Robert Later; Rudolf Beiermeister; Falko Doberenz; Michael Gelinsky; Elke Leipnitz; Gabriele Schackert; Edmund Koch; Valdas Sablinskas; Gerald Steiner
Spinal cord injury (SCI) induces complex biochemical changes, which result in inhibition of nervous tissue regeneration abilities. In this study, Fourier-transform infrared (FT-IR) spectroscopy was applied to assess the outcomes of implants made of a novel type of non-functionalized soft calcium alginate hydrogel in a rat model of spinal cord hemisection (n = 28). Using FT-IR spectroscopic imaging, we evaluated the stability of the implants and the effects on morphology and biochemistry of the injured tissue one and six months after injury. A semi-quantitative evaluation of the distribution of lipids and collagen showed that alginate significantly reduced injury-induced demyelination of the contralateral white matter and fibrotic scarring in the chronic state after SCI. The spectral information enabled to detect and localize the alginate hydrogel at the lesion site and proved its long-term persistence in vivo. These findings demonstrate a positive impact of alginate hydrogel on recovery after SCI and prove FT-IR spectroscopic imaging as alternative method to evaluate and optimize future SCI repair strategies.
BioMed Research International | 2015
Ortrud Uckermann; Roberta Galli; Rudolf Beiermeister; Kerim-Hakan Sitoci-Ficici; Robert Later; Elke Leipnitz; Ales Neuwirth; Triantafyllos Chavakis; Edmund Koch; Gabriele Schackert; Gerald Steiner
Activation of CNS resident microglia and invasion of external macrophages plays a central role in spinal cord injuries and diseases. Multiphoton microscopy based on intrinsic tissue properties offers the possibility of label-free imaging and has the potential to be applied in vivo. In this work, we analyzed cellular structures displaying endogenous two-photon excited fluorescence (TPEF) in the pathologic spinal cord. It was compared qualitatively and quantitatively to Iba1 and CD68 immunohistochemical staining in two models: rat spinal cord injury and mouse encephalomyelitis. The extent of tissue damage was retrieved by coherent anti-Stokes Raman scattering (CARS) and second harmonic generation imaging. The pattern of CD68-positive cells representing postinjury activated microglia/macrophages was colocalized to the TPEF signal. Iba1-positive microglia were found in areas lacking any TPEF signal. In peripheral areas of inflammation, we found similar numbers of CD68-positive microglia/macrophages and TPEF-positive structures while the number of Iba1-positive cells was significantly higher. Therefore, we conclude that multiphoton imaging of unstained spinal cord tissue enables retrieving the extent of microglia activation by acquisition of endogenous TPEF. Future application of this technique in vivo will enable monitoring inflammatory responses of the nervous system allowing new insights into degenerative and regenerative processes.
Journal of Biophotonics | 2017
Roberta Galli; Ortrud Uckermann; Achim Temme; Elke Leipnitz; Matthias Meinhardt; Edmund Koch; Gabriele Schackert; Gerald Steiner
Coherent anti-Stokes Raman scattering (CARS) microscopy is an emerging technique for identification of brain tumors. However, tumor identification by CARS microscopy on bulk samples and in vivo has been so far verified retrospectively on histological sections, which only provide a gross reference for the interpretation of CARS images without matching at cellular level. Therefore, fluorescent labels were exploited for direct assessment of the interpretation of CARS images of solid and infiltrative tumors. Glioblastoma cells expressing green fluorescent protein (GFP) were used for induction of tumors in mice (n = 7). The neoplastic nature of cells imaged by CARS microscopy was unequivocally verified by addressing two-photon fluorescence of GFP on fresh brain slices and in vivo. In fresh unfixed biopsies of human glioblastoma (n = 10), the fluorescence of 5-aminolevulinic acid-induced protoporphyrin IX was used for identification of tumorous tissue. Distinctive morphological features of glioblastoma cells, i.e. larger nuclei, evident nuclear membrane and nucleolus, were identified in the CARS images of both mouse and human brain tumors. This approach demonstrates that the chemical contrast provided by CARS allows the localization of infiltrating tumor cells in fresh tissue and that the cell morphology in CARS images is useful for tumor recognition. Experimental glioblastoma expressing green fluorescent protein.
Scientific Reports | 2018
Roberta Galli; Kerim H. Sitoci-Ficici; Ortrud Uckermann; Robert Later; Magda Marečková; Maria Koch; Elke Leipnitz; Gabriele Schackert; Edmund Koch; Michael Gelinsky; Gerald Steiner
The development of therapies promoting recovery after spinal cord injury is a challenge. Alginate hydrogels offer the possibility to develop biocompatible implants with mechanical properties tailored to the nervous tissue, which could provide a permissive environment for tissue repair. Here, the effects of non-functionalized soft calcium alginate hydrogel were investigated in a rat model of thoracic spinal cord hemisection and compared to lesioned untreated controls. Open field locomotion tests were employed to evaluate functional recovery. Tissue analysis was performed with label-free multiphoton microscopy using a multimodal approach that combines coherent anti-Stokes Raman scattering to visualize axonal structures, two-photon fluorescence to visualize inflammation, second harmonic generation to visualize collagenous scarring. Treated animals recovered hindlimb function significantly better than controls. Multiphoton microscopy revealed that the implant influenced the injury-induced tissue response, leading to decreased inflammation, reduced scarring with different morphology and increased presence of axons. Demyelination of contralateral white matter near the lesion was prevented. Reduced chronic inflammation and increased amount of axons in the lesion correlated with improved hindlimb functions, being thus relevant for locomotion recovery. In conclusion, non-functionalized hydrogel improved functional outcome after spinal cord injury in rats. Furthermore, label-free multiphoton microscopy qualified as suitable technique for regeneration studies.
Scientific Reports | 2018
Grace Collord; Patrick Tarpey; Natalja Kurbatova; Inigo Martincorena; Sebastian Moran; Manuel Castro; Tibor Nagy; Graham R. Bignell; Francesco Maura; Matthew Young; Jorge Berna; Jose M. C. Tubio; Chris Mcmurran; Adam M. H. Young; Mathijs A. Sanders; Imran Noorani; Stephen J. Price; Colin Watts; Elke Leipnitz; Gabriele Schackert; Danita M. Pearson; Abel Devadass; Zvi Ram; V. Peter Collins; Kieren Allinson; Michael D. Jenkinson; Rasheed Zakaria; Khaja Syed; C. Oliver Hanemann; Jemma Dunn
Anaplastic meningioma is a rare and aggressive brain tumor characterised by intractable recurrences and dismal outcomes. Here, we present an integrated analysis of the whole genome, transcriptome and methylation profiles of primary and recurrent anaplastic meningioma. A key finding was the delineation of distinct molecular subgroups that were associated with diametrically opposed survival outcomes. Relative to lower grade meningiomas, anaplastic tumors harbored frequent driver mutations in SWI/SNF complex genes, which were confined to the poor prognosis subgroup. Aggressive disease was further characterised by transcriptional evidence of increased PRC2 activity, stemness and epithelial-to-mesenchymal transition. Our analyses discern biologically distinct variants of anaplastic meningioma with prognostic and therapeutic significance.
Journal of Neuro-oncology | 2012
Tareq A. Juratli; Kathrin Geiger; B. Klink; Elke Leipnitz; Thomas Pinzer; Silke Soucek; E. Schrok; Gabriele Schackert; Dietmar Krex
Acta Neurochirurgica | 2018
Kerim H. Sitoci-Ficici; Marina Matyash; Ortrud Uckermann; Roberta Galli; Elke Leipnitz; Robert Later; Chrysanthy Ikonomidou; Michael Gelinsky; Gabriele Schackert
Acta Neurochirurgica | 2016
Volker M. Betz; K. Hakan Sitoci-Ficici; Ortrud Uckermann; Elke Leipnitz; Anne Iltzsche; Christian Thirion; Michael Salomon; Hans Zwipp; Gabriele Schackert; Oliver B. Betz