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451 result(s) for "Wick, W."
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Improvement of functional outcome for patients with newly diagnosed grade 2 or 3 gliomas with co-deletion of 1p/19q – IMPROVE CODEL: the NOA-18 trial
Background Given the young age of patients with CNS WHO grade 2 and 3 oligodendrogliomas and the relevant risk of neurocognitive, functional, and quality-of-life impairment with the current aggressive standard of care treatment, chemoradiation with PCV, of the tumour located in the brain optimizing care is the major challenge. Methods NOA-18 aims at improving qualified overall survival (qOS) for adult patients with CNS WHO grade 2 and 3 oligodendrogliomas by randomizing between standard chemoradiation with up to six six-weekly cycles with PCV and six six-weekly cycles with lomustine and temozolomide (CETEG) ( n  = 182 patients per group accrued over 4 years) thereby delaying radiotherapy and adding the chemoradiotherapy concept at progression after initial radiation-free chemotherapy, allowing for effective salvage treatment and delaying potentially deleterious side effects. QOS represents a new concept and is defined as OS without functional and/or cognitive and/or quality of life deterioration regardless of whether tumour progression or toxicity is the main cause. The primary objective is to show superiority of an initial CETEG treatment followed by partial brain radiotherapy (RT) plus PCV (RT-PCV) at progression over partial brain radiotherapy (RT) followed by procarbazine, lomustine, and vincristine (PCV) chemotherapy (RT-PCV) and best investigators choice (BIC) at progression for sustained qOS. An event concerning a sustained qOS is then defined as a functional and/or cognitive and/or quality of life deterioration after completion of primary therapy on two consecutive study visits with an interval of 3 months, tolerating a deviation of at most 1 month. Assessments are done with a 3-monthly MRI, assessment of the NANO scale, HRQoL, and KPS, and annual cognitive testing. Secondary objectives are evaluation and comparison of the two groups regarding secondary endpoints (short-term qOS, PFS, OS, complete and partial response rate). The trial is planned to be conducted at a minimum of 18 NOA study sites in Germany. Discussion qOS represents a new concept. The present NOA trial aims at showing the superiority of CETEG plus RT-PCV over RT-PCV plus BIC as determined at the level of OS without sustained functional deterioration for all patients with oligodendroglioma diagnosed according to the most recent WHO classification. Trial registration Clinicaltrials.gov NCT05331521 . EudraCT 2018–005027-16.
Patient, Relative and Staff Experiences of Clinical Trial Participation in Neurooncology: “Maybe You Can Also Show the Positive, No Matter How It Ends”
There is a lack of evidence regarding how patients with malignant brain tumor and their relatives experience participation in neurooncological clinical trials. Similarly, insights from the perspective of trial staff caring for this group of patients are missing. This study aims to investigate patient, relative and trial staff experiences regarding participation in clinical neurooncological trials. Within a qualitative exploratory study, 29 semi-structured interviews with brain tumor patients, relatives and trial staff were conducted and analyzed using reflexive thematic analysis (RTA) by Braun and Clarke. A patient researcher and patient council were involved in data analysis and interpretation. Four themes were developed reflecting significant aspects of the trial experience: 1. \"It all revolves around hope\"; 2. \"Trial participation: experiencing unique medical care\"; 3. \"Everyone's roles are changing\"; 4. \"Communication as a possible area of conflict\". Experiencing trial participation and general medical treatment were found to be interconnected to such a degree that they were often not meaningfully distinguished by patients and relatives. In addition to assessing traditional endpoints for patient outcomes, we recommend increased emphasis on investigating the impact of the \"soft\" components constituting trial participation. Due to the interconnectedness of medical treatment and trial participation, we recommend further investigation in comparison to experiences in regular care. A deeper understanding of trial participation is needed to inform improvements for patient experiences and staff satisfaction alongside medical and scientific progress.
Estimation of Wear and Lifetime for an Improved Turbine Operation
Design, construction and certification of wind turbines (WT) generally target a lifetime of at least twenty years. Depending on the specified design criteria in comparison with the’real’ conditions on site lifetime may fall below or pass over the design lifetime targets. After installation and during operation WT continuously suffer from incremental damage due to loads, fatigue and the continuous exposure to the physical environment and operating conditions. The initially inherent wear reserve of the WT or its components permanently decreases until it finally reaches predefined safety margins or the occurrence of premature component failure. The objective of the work is to identify quantifiable wear-out metrics and to deduce information on lifetime issues in order to optimise WT operation. The method divides into a simplified approach explaining the general concept and its implementation and adaption from design to in-situ conditions. Furthermore, the methodology is transferred to a component-specific level, namely generator windings, in order to evaluate the general suitability for non-mechanical load exposures. Finally, economic issues including an economic optimisation strategy considering previously calculated wear-out figures complete the work.
DNA methylation, transcriptome and genetic copy number signatures of diffuse cerebral WHO grade II/III gliomas resolve cancer heterogeneity and development
Background Diffuse lower WHO grade II and III gliomas (LGG) are slowly progressing brain tumors, many of which eventually transform into a more aggressive type. LGG is characterized by widespread genetic and transcriptional heterogeneity, yet little is known about the heterogeneity of the DNA methylome, its function in tumor biology, coupling with the transcriptome and tumor microenvironment and its possible impact for tumor development. Methods We here present novel DNA methylation data of an LGG-cohort collected in the German Glioma Network containing about 85% isocitrate dehydrogenase (IDH) mutated tumors and performed a combined bioinformatics analysis using patient-matched genome and transcriptome data. Results Stratification of LGG based on gene expression and DNA-methylation provided four consensus subtypes. We characterized them in terms of genetic alterations, functional context, cellular composition, tumor microenvironment and their possible impact for treatment resistance and prognosis. Glioma with astrocytoma-resembling phenotypes constitute the largest fraction of nearly 60%. They revealed largest diversity and were divided into four expression and three methylation groups which only partly match each other thus reflecting largely decoupled expression and methylation patterns. We identified a novel G-protein coupled receptor and a cancer-related ‘keratinization’ methylation signature in in addition to the glioma-CpG island methylator phenotype (G-CIMP) signature. These different signatures overlap and combine in various ways giving rise to diverse methylation and expression patterns that shape the glioma phenotypes. The decrease of global methylation in astrocytoma-like LGG associates with higher WHO grade, age at diagnosis and inferior prognosis. We found analogies between astrocytoma-like LGG with grade IV IDH -wild type tumors regarding possible worsening of treatment resistance along a proneural-to-mesenchymal axis. Using gene signature-based inference we elucidated the impact of cellular composition of the tumors including immune cell bystanders such as macrophages. Conclusions Genomic, epigenomic and transcriptomic factors act in concert but partly also in a decoupled fashion what underpins the need for integrative, multidimensional stratification of LGG by combining these data on gene and cellular levels to delineate mechanisms of gene (de-)regulation and to enable better patient stratification and individualization of treatment.
Biologically-Directed Modeling Reflects Cytolytic Clearance of SIV-Infected Cells In Vivo in Macaques
The disappointing outcomes of cellular immune-based vaccines against HIV-1 despite strong evidence for the protective role of CD8⁺ T lymphocytes (CTLs) has prompted revisiting the mechanisms of cellular immunity. Prior data from experiments examining the kinetics of Simian Immunodeficiency Virus (SIV) clearance in infected macaques with or without in vivo CD8 depletion were interpreted as refuting the concept that CTLs suppress SIV/HIV by direct killing of infected cells. Here we briefly review the biological evidence for CTL cytolytic activity in viral infections, and utilize biologically-directed modeling to assess the possibility of a killing mechanism for the antiviral effect of CTLs, taking into account the generation, proliferation, and survival of activated CD4⁺ and CD8⁺ T lymphocytes, as well as the life cycle of the virus. Our analyses of the published macaque data using these models support a killing mechanism, when one considers T lymphocyte and HIV-1 lifecycles, and factors such as the eclipse period before release of virions by infected cells, an exponential pattern of virion production by infected cells, and a variable lifespan for acutely infected cells. We conclude that for SIV/HIV pathogenesis, CTLs deserve their reputation as being cytolytic.
A comprehensive analysis of vascular complications in 3,889 glioma patients from the German Glioma Network
Ischemic strokes, intracranial hemorrhages (ICH) and deep venous thromboembolism (DVT) are clinically important events in patients with gliomas. In this multicentre, noninterventional observational study, current data pertaining to frequency, contributing factors and outcomes of vascular events during times of anti-angiogenic therapy with the antibody against vascular endothelial growth factor, bevacizumab (BEV) was collected from the German Glioma Network. Among 3,889 glioma patients, 70 ischemic strokes (1.8 %) and 123 ICH (3.2 %) were recorded. 143 DVT (5.0 %) were recorded in 2,855 patients. Rates of DVT and ICH, but not of ischemic strokes, increased with the World Health Organization (WHO) grade of glioma. In 81 BEV-treated patients, five ischemic strokes (6.2 %), one ICH (1.2 %) and six DVT (7.4 %) were documented. Compared to patients that were not treated with BEV, ischemic stroke rate was significantly higher during treatment with BEV ( p  < 0.001). The rates of DVT ( p  = 0.123) or ICH ( p  = 0.571) in BEV-treated patients did not differ. On cerebral magnetic resonance imaging (MRI), BEV-related ischemic strokes appeared as diffusion-restricted sites next to contrast-enhancing tumor. 67 % of ICH, 61 % of ischemic strokes and 18 % of DVT occurred postoperatively (within 30 days after tumor resection). Outcome after postoperative ICH was significantly worse than after spontaneous ICH ( p  = 0.008). Ischemic stroke outcomes did not differ between postoperative and spontaneous occurrence ( p  = 0.401). Rate of pulmonary embolism did not differ significantly between postoperative and spontaneous DVT ( p  = 0.133). Relatively low rates of ICH and DVT might be partially due to a high proportion of low-grade gliomas in this patient cohort. The finding of a relevant number of symptomatic, therapy-associated intracerebral diffusion restrictions should be controlled in ongoing phase III studies.
Aryl hydrocarbon receptor inhibition downregulates the TGF-β/Smad pathway in human glioblastoma cells
The dioxin/aryl hydrocarbon receptor (AhR) is a transcription factor, which has been attributed a role in human cancerogenesis, cell cycle progression and transforming growth factor-β (TGF-β) signaling. As TGF-β is an important mediator of the malignant phenotype of human gliomas, we studied AhR expression and function in glioma cells. AhR was not only expressed in glioma cells in vitro , but was also detected in human gliomas in vivo by immunohistochemistry, with a predominantly nuclear staining in glioblastomas. The AhR agonist, 3-methylcholanthrene, induced AhR nuclear translocation and upregulated mRNA levels of the AhR target gene, cytochrome P450 1A1 (CYP1A1). Conversely, pharmacological inhibition of AhR using the novel AhR antagonist, CH-223191, or AhR gene silencing using small interfering RNA showed that constitutive AhR activity positively controls TGF-β1, TGF-β2 and latent TGF-β-binding protein-1 protein levels in malignant glioma cells. Moreover, antagonism of AhR reduced clonogenic survival and invasiveness of glioma cells. In contrast, AhR regulates TGF-β signaling negatively in non-neoplastic astrocytes. Thus, the pathogenesis of glioma formation may involve altered AhR regulation of the TGF-β/Smad pathway, and AhR may represent a promising target for the treatment of human malignant gliomas and other diseases associated with pathological TGF-β activity.
Posterior Circulation Acute Stroke Prognosis Early Computed Tomography Score Using Hypointense Vessels on Susceptibility Weighted Imaging Independently Predicts Outcome in Patients with Basilar Artery Occlusion
Appearance of hypointense vessels on susceptibility weighted imaging (SWI) has been reported to correlate with outcome in patients with ischemia of the anterior circulation. This study investigates the correlation between the appearance of hypointense vessels on SWI after recanalization therapy and outcome in patients with basilar artery occlusion. Patients with basilar artery occlusion who were treated with endovascular recanalization or intravenous alteplase and received an MRI including SWI after therapy were retrieved from the hospital database for retrospective analysis. Posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pcASPECTS) was calculated based on regions displaying hypointense vessels on SWI and compared to lesions on diffusion weighted imaging (DWI). Subsequently, SWI based pcASPECTS was correlated with outcome determined with modified Rankin Scale (mRS), categorized as favorable outcome (mRS 0-2) or unfavorable outcome (3-6). Twenty-two MRI of patients with basilar artery occlusion were analyzed. In seven out of eight areas of the pcASPECTS hypointense vessels on SWI were significantly correlated to areas of restricted diffusion on DWI. In univariate analysis median pcASPECTS on SWI was significantly higher in patients with favorable outcome (7.5 vs. 5, p=0.02). In a multivariate analysis pcASPECTS on SWI was an independent predictor of favorable outcome (OR 2.02; CI [1.02;3,99]; p=0.04). pcASPECTS based on hypointense vessels on SWI after therapy predicts outcome in patients with basilar artery occlusion and might potentially be used as an additional imaging biomarker in the management of patients with stroke in the posterior circulation. This needs to be confirmed in larger prospective clinical trials.
Tryptophan degradation in autoimmune diseases
Recent evidence points to tryptophan (Trp) degradation as a potent immunosuppressive mechanism involved in the maintenance of immunological tolerance. Both Trp depletion and downstream Trp catabolites (TCs) appear to synergistically confer protection against excessive inflammation. In this review, we give an overview of the immunosuppressive properties of Trp degradation with special focus on TCs. Constitutive and inducible Trp degradation in different cell types and tissues of human and murine origin is summarized. We address the influence of Trp degradation on different aspects of autoimmune disorders such as multiple sclerosis. Possible therapeutic approaches for autoimmune disorders targeting Trp degradation are presented, and key issues relevant for the development of such therapeutic strategies are discussed.
Glioma Cell Invasion: Regulation of Metalloproteinase Activity by TGF-β
Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that selectively degrade components of the extracellular matrix. MMPs are implicated in tumor cell invasion because they mediate the breakdown of the basal membrane. In addition, they seem to be important for the creation and maintenance of a microenvironment that facilitates tumor cell survival. Among the essential characteristics of human malignant gliomas are infiltrative growth, angiogenesis and suppression of antitumor immune surveillance. Transforming growth factor-beta (TGF-beta) is intimately involved in the regulation of these processes. We have previously demonstrated that TGF-beta promotes the migration of LN- 18 and LN-229 glioma cells via a process that may involve the upregulation of alphaVbeta3 integrin expression. Furthermore, we have defined a novel pathway for hepatocyte growth factor (HGF)-induced glioma cell migration and invasion which requires the induction of TGF-beta2 expression. Here, we demonstrate that TGF-beta2 induces MMP-2 expression and suppresses tissue inhibitor of metalloproteinases (TIMP)-2 expression and that concentration-dependently promotes the invasion of U87MG and LN-229 glioma cells in a matrigel invasion assay. Similarly, ectopic expression of the anti-apoptotic BCL-x, protein leads to enhanced matrigel invasion by LN-18 and LN-229 glioma cells. We outline the possible interrelations of TGF-beta, proteins of the BCL-2 family, integrins and metalloprotease activity. By virtue of its promotion of glioma invasion and its growth regulatory and immunomodulatory properties. TGF-beta continues to be one of the most promising targets for the experimental therapy of human malignant glioma.