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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Einfluss der Radikalität der Resektion eines Glioblastoma multiforme in Kombination mit einer adjuvanten Chemotherapie auf das Survival

Hubertus, Jochen 25 January 2005 (has links)
Ziel: Den Einfluss der Radikalität der Resektion eines Glioblastoma multiforme in Kombination mit einer adjuvanten Chemotherapie auf das Survival heraus zu arbeiten. Methoden: Zwischen 1997 und 2000 wurden 55 Patienten, die an einem primären Glioblastoma multiforme erkrankten, einer Tumorresektion unterzogen. Von den 55 Patienten waren 36 männlich und 19 weiblich. Im Mittel erkrankten die Patienten mit 56 Jahren. Tumorresektion und Radiatio wurden bei allen Patienten durchgeführt. 20 Patienten wurden darüber hinaus noch mit einer adjuvanten Chemotherapie behandelt. Ergebnisse: Die Patienten, die mit einer Chemotherapie behandelt wurden, zeigten ein signifikant längeres Überleben (85 versus 44 weeks). Und die Patienten mit einem postoperativen Resttumor profitierten am meisten von der adjuvanten Chemotherapie (75 versus 39 weeks). Zusammenfassung: Patienten, die mit einer adjuvanten Chemotherapie behandelt wurden zeigten ein signifikant längeres Überleben als die Patienten ohne diese Therapie. / Objective: To evaluate the influence of resection of a glioblastoma multiforme in combination with adjuvant chemotherapy regarding survival. Methods: From 1997 to 2000, 55 patients with primary glioblastoma multiforme underwent a tumor resection. Of the 55 patients 36 were male, 19 female, with an average age of 56 years. Tumor resection and radiatio were performed in all patients. 20 patients were treated additionally with chemotherapy. Results: Patients treated with chemotherapy displayed a significant longer survival (85 versus 44 weeks). And the patients with a residual postoperative tumor mass did benefit from adjuvant chemotherapy (75 versus 39 weeks). Conclusion: Patients treated with adjuvant chemotherapy had a significant longer survival then those without this therapy.
62

Klinischer Verlauf und Analyse des Rezidivmusters von 111 Patienten mit anaplastischem Astrozytom oder Glioblastoma multiforme nach Operation und lokaler Strahlentherapie

Graubner, Sebastian 25 May 2005 (has links)
Die vorliegende Arbeit ist eine retrospektive Kohortenstudie, welche alle Patienten einschloß, die im Zeitraum von 07/1988 bis 06/1997 aufgrund eines anaplastischen Astrozytoms oder eines Glioblastoma multiforme im damaligen Rudolf-Virchow-Klinikum in Berlin eine Strahlentherapie des Kopfes erhielten. Von den 111 Patienten erlitten im Beobachtungszeitraum 85 ein radiologisches Rezidiv. Die mediane Überlebenszeit betrug 9 Monate. 69 der Rezidive waren Zentralrezidive, 7 Randrezidive und 9 Fernrezidive. Auch die Rand- und Fernrezidive rezidivierten zusätzlich am Ort der Primärläsion. Es konnte gezeigt werden dass ein Sicherheitsabstand von 2-3 cm ausreicht um 90% der Rezidive vollständig zu erfassen und dass die lokale Kontrolle weiterhin das Hauptproblem bei der Behandlung dieser malignen Gliome ist. / This retrospective study reviews the data of 111 patients treated from 07/1988 to 06/1997 at the Rudolf-Virchow-Klinikum in Berlin. Both patients with anaplastic astrocytoma and glioblastoma multiforme were included. 85 patients showed radiological recurrence of tumour. Median survival was 9 months. 69 recurrences were central, 7 near and 9 distant recurrences. Near and distant recurrences were always multifocal, i. e. they recurred also at central locations. It was shown that a safety margin of 2-3 cm is sufficient to completely cover 90% of recurrent tumour. Local failure is still the primary difficulty in treating these malignant glioma.
63

Molecular Mechanisms Associated with Chromosomal and Microsatellite Instability in Sporadic Glioblastoma multiforme

Martinez, Ramon, Schackert, Hans-K., Plaschke, Jens, Baretton, Gustavo, Appelt, Hella, Schackert, Gabriele 12 February 2014 (has links) (PDF)
Objective: Two chromosomal instability (CIN) pathways are described in glioblastoma multiforme (GBM), type 1 and type 2, which can be observed in up to 70% of the cases. Microsatellite instability (MSI) plays a pathogenic role in sporadic cancers such as colon, gastric and endometrial carcinomas with deficient mismatch repair (MMR). We aimed to perform a comprehensive analysis of the relationship between CIN and MSI mechanisms in sporadic glioblastomas. Methods: 129 GBMs were examined (109 newly diagnosed and 20 relapses) investigating MSI, immunohistochemical expression of MMR proteins as well as sequencing and promoter methylation of hMLH1. We characterized the molecular changes frequently correlated with CIN in MSI+ GBMs and compared them with 26 microsatellite-stable tumors. Results: Low-level MSI was observed in 11 of 129 (8.5%) cases and was higher in relapses than in primary GBMs (25 vs. 5.5%, p = 0.027). High-level MSI was not found in any case. A deficient expression of MLH1 and PMS2 without hMLH1 inactivation was observed only in one giant cell GBM. 55% of the MSI+ GBMs showed a profile which did not correspond to one of the known CIN pathways. An inverse association was observed between MSI and mutations of both p53 and PTEN. Conclusions: Our data suggest that CIN and MSI contribute to the genomic instability in GBMs via independent pathways. Since MSI was significantly more frequent in relapses, it might play a role in the malignant progression of GBM. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
64

A systematic review on the characteristics, treatments and outcomes of the patients with primary spinal glioblastomas or gliosarcomas reported in literature until March 2015

Beyer, Stefanie, von Bueren, André O., Klautke, Gunther, Guckenberger, Matthias, Kortmann, Rolf-Dieter, Pietschmann, Sophie, Müller, Klaus January 2016 (has links)
Our aim was to determine the characteristics, treatments and outcomes of patients with primary spinal glioblastomas (GB) or gliosarcomas (GS) reported in literature until March 2015. PubMed and Web of Science were searched for peer-reviewed articles pertaining to cases of glioblastomas / gliosarcomas with primary spinal origin, using predefined search terms. Furthermore we performed hand searches tracking the references from the selected papers. Eighty-two articles published between 1938 and March 2015 were eligible. They reported on 157 patients. Median age at diagnosis was 22 years. The proportion of patients who received adjuvant chemo- or radiotherapy clearly increased from the time before 1980 until present. Median overall survival from diagnosis was 8.0 ± 0.9 months. On univariate analysis age influenced overall survival, whereas tumor location, gender and the extent of initial resection did not. Outcomes did not differ between children (< 18 years) and adults. However, the patients who were treated after 1980 achieved longer survival times than the patients treated before. On multivariable analysis only age (< 60 years) and the time period of treatment (>1980) were confirmed as positive independent prognostic factors. In conclusion, primary spinal GB / GS mainly affect younger patients and are associated with a dismal prognosis. However, most likely due to the increasing use of adjuvant treatment, modest therapeutic progress has been achieved over recent decades. The characteristics and treatments of primary spinal glioblastomas should be entered into a central registry in order to gain more information about the ideal treatment approach in the future.
65

Molecular Mechanisms Associated with Chromosomal and Microsatellite Instability in Sporadic Glioblastoma multiforme

Martinez, Ramon, Schackert, Hans-K., Plaschke, Jens, Baretton, Gustavo, Appelt, Hella, Schackert, Gabriele January 2004 (has links)
Objective: Two chromosomal instability (CIN) pathways are described in glioblastoma multiforme (GBM), type 1 and type 2, which can be observed in up to 70% of the cases. Microsatellite instability (MSI) plays a pathogenic role in sporadic cancers such as colon, gastric and endometrial carcinomas with deficient mismatch repair (MMR). We aimed to perform a comprehensive analysis of the relationship between CIN and MSI mechanisms in sporadic glioblastomas. Methods: 129 GBMs were examined (109 newly diagnosed and 20 relapses) investigating MSI, immunohistochemical expression of MMR proteins as well as sequencing and promoter methylation of hMLH1. We characterized the molecular changes frequently correlated with CIN in MSI+ GBMs and compared them with 26 microsatellite-stable tumors. Results: Low-level MSI was observed in 11 of 129 (8.5%) cases and was higher in relapses than in primary GBMs (25 vs. 5.5%, p = 0.027). High-level MSI was not found in any case. A deficient expression of MLH1 and PMS2 without hMLH1 inactivation was observed only in one giant cell GBM. 55% of the MSI+ GBMs showed a profile which did not correspond to one of the known CIN pathways. An inverse association was observed between MSI and mutations of both p53 and PTEN. Conclusions: Our data suggest that CIN and MSI contribute to the genomic instability in GBMs via independent pathways. Since MSI was significantly more frequent in relapses, it might play a role in the malignant progression of GBM. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
66

Der Metabolismus aromatischer Aminosäuren als potentieller Aktivator des Arylhydrocarbon Rezeptors und dessen Auswirkungen auf die Immunantwort

Loth, Stefanie 29 July 2020 (has links)
In dieser Arbeit wurde die Rolle der L-Aminosäureoxidase IL4I1 für die Progression von Glioblastomen analysiert. IL4I1 wird in diesem Hirntumor erhöht exprimiert und führt dadurch zu einem Abbau der drei aromatischen Aminosäuren Tryptophan (Trp), Phenylalanin und Tyrosin zu ihren entsprechenden α-Ketosäuren (Pyruvaten). In-vitro-Versuche mit IL4I1-überexprimierenden Glioblastomzelllinien zeigen, dass nur das aus Trp-gebildete Indol-3-pyruvat (I3P) bzw. dessen nachgeschaltete Abbauprodukte eine Aktivierung des Arylhydrocarbon Rezeptors (AHR) und seiner Signaltransduktion in Glioblastomen bewirkt. Des Weiteren wurde der Einfluss von IL4I1 in der Tumor-Mikroumgebung auf die Kompetenz von T-Zellen charakterisiert. Das von den Tumorzellen gebildete und sezernierte I3P vermittelt eine Aktivierung des AHR in beiden T-Zellsubpopulationen. Damit einhergehend werden zwei Mechanismen ausgelöst, die die Tumorprogression fördern: eine Proliferationsinhibierung CD8+ zytotoxischer T-Zellen und eine vermehrte Differenzierung immunsuppressiver Treg.
67

Radiomics analyses for outcome prediction in patients with locally advanced rectal cancer and glioblastoma multiforme using multimodal imaging data

Shahzadi, Iram 13 November 2023 (has links)
Personalized treatment strategies for oncological patient management can improve outcomes of patient populations with heterogeneous treatment response. The implementation of such a concept requires the identification of biomarkers that can precisely predict treatment outcome. In the context of this thesis, we develop and validate biomarkers from multimodal imaging data for the outcome prediction after treatment in patients with locally advanced rectal cancer (LARC) and in patients with newly diagnosed glioblastoma multiforme (GBM), using conventional feature-based radiomics and deep-learning (DL) based radiomics. For LARC patients, we identify promising radiomics signatures combining computed tomography (CT) and T2-weighted (T2-w) magnetic resonance imaging (MRI) with clinical parameters to predict tumour response to neoadjuvant chemoradiotherapy (nCRT). Further, the analyses of externally available radiomics models for LARC reveal a lack of reproducibility and the need for standardization of the radiomics process. For patients with GBM, we use postoperative [11C] methionine positron emission tomography (MET-PET) and gadolinium-enhanced T1-w MRI for the detection of the residual tumour status and to prognosticate time-to-recurrence (TTR) and overall survival (OS). We show that DL models built on MET-PET have an improved diagnostic and prognostic value as compared to MRI.
68

THE INFLUENCES OF MATRIX METALLOPROTEINASE-1 EXPRESSION ON GLIOBLASTOMA PATHOLOGY

Pullen, Nicholas 30 March 2010 (has links)
Glioblastoma multiforme (GBM) is an aggressive central nervous system (CNS) cancer characterized by enhanced tumor cell motility, pernicious invasion into the normal brain, extensive tumor-induced angiogenesis, and adaptive resistance to current therapeutic paradigms. One of the difficulties associated with GBM is the ability of the tumor cells to infiltrate normal CNS tissue. Neurosurgeons can remove the primary tumor mass, but peripheral cells that are inaccessible will ultimately result in a secondary lesion that can lead to death. The matrix metalloproteinases (MMP) are well known for their abilities to facilitate processes of cellular motility and invasion through their clearance of extracellular matrix (ECM). A specific member of this family, MMP-1, is not observed in normal brain, yet its expression is a common characteristic of GBM. The various causes of MMP-1 expression, and its consequences in GBM cells are unknown. As such, functional studies were conducted related to the induction of MMP-1 expression via another molecule intrinsic to GBM, nitric oxide (NO). The exposure of GBM cell lines to nanomolar concentrations of NO produced significant inductions of MMP-1 expression and GBM cell motility. The specific removal of MMP-1 with siRNA elicited an abrogation of NO-stimulated motility, suggesting a pathological contribution by this enzyme. Furthermore, recent accumulating evidence suggests that MMP-1 contributes to tumor cell survival and related angiogenesis in other cancer settings. To investigate these capabilities in GBM, cell lines were stably engineered to have either MMP-1 over-expression or knock-down. Both tumor formation and size were significantly reduced with MMP-1 knock-down and significantly increased with over-expression. In a model of GBM cell-induced angiogenesis, the presence of MMP-1 contributed to an angiogenic phenotype. Further angiogenesis studies revealed a significant recruitment of host endothelium to the tumor interstitium in vivo. Proteomic studies suggest that one mechanism by which MMP-1 could influence angiogenesis is through the easement of the anti-angiogenic tissue inhibitor of metalloproteinases-4 (TIMP-4), since the removal of MMP-1 elicits a significant increase in TIMP-4 detection. Altogether, these functional data present MMP-1 as a promising target for future therapeutic investigation, because it is unique to the GBM environment and contributes to key overlapping GBM pathologies.
69

Lapatinib and Sorafenib Kill GBM Tumor Cells in a Greater than Additive Manner

Tavallai, Seyedmehrad 25 November 2013 (has links)
Glioblastoma multiforme (GBM) is the most common and malignant brain tumor in adults, affecting thousands of people worldwide every year, with a life expectancy, post diagnosis of 12 months. Surgery, radiotherapy and chemotherapy together, result in an overall mean survival not exceeding 15 months. Targeted therapeutic agents sorafenib, an oral multi kinase inhibitor, and lapatinib, an epidermal growth factor receptor (EGFR) inhibitor, used in combination have been shown to kill GBM cells be through inhibition of major growth mediating signaling pathways that are frequently over expressed in gliomas, including mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/ protein kinase B (PI3K/AKT). Sorafenib can restore lapatinib induced cytotoxicity by down regulation of myeloid cell leukaemia-1 (Mcl-1) expression. Prior studies have shown Mcl-1 to play an important role in resistance to lapatinib. Furthermore, data indicated that this drug combination is able to trigger activation of autophagic and apoptotic pathways and induce endoplasmic reticulum (ER) stress response in GBM cells, collectively resulting in cell death. In conclusion, data presented here demonstrates that the combination of sorafenib and lapatinib can kill GBM cells in a greater than additive fashion, through induction of autophagy, apoptotic events (extrinsic and intrinsic) and ER stress.
70

HORMONE EPIMERS REGULATE ER STRESS AND CORE REGULATORY GENES: NETWORK ANALYSIS WITH APPLICATIONS TO GLIOMA AND CHRONIC PRESSURE ULCERS

Shaak, Thomas L. 01 January 2013 (has links)
DHEA has been determined to have medically significant activity and is the parent compound to the more active metabolites; 17α-AED, 17β-AED and 17β-AET, which exhibit strong biological activity that has been attributed to androgenic, estrogenic or anti-glucocorticoid activity in vivo and in vitro. This study compared DHEA, 17α-AED, 17β-AED and 17β-AET for their ability to activate the human AR, ER and GR receptors and determine the relative androgenicity, estrogenicity and glucocorticoid activity. The results show that, at the receptor level, these androstene hormones are weak AR and even weaker ER activators. Direct androstene hormone activation of the human AR, ERα, and ERβ may not be essential for their biological function. Similarly, these hormones indirectly activated the human GR receptor; only in the presence of high dexamethasone concentrations. These results underscore the major difference between androstene hormone interactions with these nuclear receptors. 17β-AED and 17α-AED, androstene epimers that produce either survival or death, were utilized to treat T98G Glioblastoma cells. We identified 26 genes oppositely regulated by 17β-AED and 17α-AED to directly affect the cellular life or death decision. Network analysis demonstrated that these 26 genes are essential to regulating three critical Glioblastoma pathways. This report, for the first time, demonstrates that naturally occurring, chemically identical adrenal hormones (17β-AED or 17α-AED) direct a cellular life or death decision through contrasting modulation of identical signaling pathways and core regulators. Chronic pressure ulcers represent a significant health problem and are characterized by hypoxia, bacterial infection, repetitive ischemia/reperfusion and altered cellular and systemic stress responses. Whole genome microarray analysis was utilized in conjunction with IPA® premiere networking software to analyze chronic wound edge tissue. IPA® network analysis identified Ubiquitin C (UBC) as the most significant network. Sixteen (16) ubiquitin C associated genes were identified to be different in the chronic pressure ulcer and normal skin control. Targeted network analysis associated core regulators to 8 UBC associated genes that are unique to chronic pressure ulcers. The identification of these genes will allow the establishment of more effective treatments for Spinal Cord Injury (SCI) patients with chronic pressure ulcers.

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