16 research outputs found

    Effects of Dual Targeting of Tumor Cells and Stroma in Human Glioblastoma Xenografts with a Tyrosine Kinase Inhibitor against c-MET and VEGFR2

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    Contains fulltext : 118357.pdf (publisher's version ) (Open Access)Anti-angiogenic treatment of glioblastoma with Vascular Endothelial Growth Factor (VEGF)- or VEGF Receptor 2 (VEGFR2) inhibitors normalizes tumor vessels, resulting in a profound radiologic response and improved quality of life. This approach however does not halt tumor progression by diffuse infiltration, as this phenotype is less angiogenesis dependent. Combined inhibition of angiogenesis and diffuse infiltrative growth would therefore be a more effective treatment approach in these tumors. The HGF/c-MET axis is important in both angiogenesis and cell migration in several tumor types including glioma. We therefore analyzed the effects of the c-MET- and VEGFR2 tyrosine kinase inhibitor cabozantinib (XL184, Exelixis) on c-MET positive orthotopic E98 glioblastoma xenografts, which routinely present with angiogenesis-dependent areas of tumor growth, as well as diffuse infiltrative growth. In cultures of E98 cells, cabozantinib effectively inhibited c-MET phosphorylation, concomitant with inhibitory effects on AKT and ERK1/2 phosphorylation, and cell proliferation and migration. VEGFR2 activation in endothelial cells was also effectively inhibited . Treatment of BALB/c nu/nu mice carrying orthotopic E98 xenografts resulted in a significant increase in overall survival. Cabozantinib effectively inhibited angiogenesis, resulting in increased hypoxia in angiogenesis-dependent tumor areas, and induced vessel normalization. Yet, tumors ultimately escaped cabozantinib therapy by diffuse infiltrative outgrowth via vessel co-option. Of importance, in contrast to the results from experiments, blockade of c-MET activation was incomplete, possibly due to multiple factors including restoration of the blood-brain barrier resulting from cabozantinib-induced VEGFR2 inhibition. In conclusion, cabozantinib is a promising therapy for c-MET positive glioma, but improving delivery of the drug to the tumor and/or the surrounding tissue may be needed for full activity

    Glioma: experimental models and reality

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    Effects of ileocolonic delivered vitamin B2, B3 and C (ColoVit) or the Groningen anti-inflammatory diet on disease course and microbiome of patients with Crohn’s disease (VITA-GrAID study): a protocol for a randomised and partially blinded trial

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    Background Diet plays a pivotal role in the onset and progression of Crohn’s disease (CD). Nutritional interventions revealed effects on intestinal inflammation and gut microbial composition. However, data from well-designed and controlled dietary trials are lacking. Therefore, evidence-based dietary recommendations are still unavailable to patients and physicians. Here, we aim to investigate the effects of an evidence-based anti-inflammatory diet, and an ileocolonic-targeted capsule containing vitamin B2, B3 and C (ColoVit) on patients with CD and their healthy household members.Methods and analysis In this multicentre, randomised, placebo-controlled, partially blinded nutritional intervention trial, we aim to recruit 255 CD patients with Harvey-Bradshaw Index <8 and a faecal calprotectin (FCal) cut-off of ≄100 ”g/g at baseline. Participants will be randomised into two experimental intervention groups and one placebo group. In the experimental groups, participants will either adhere to the Groningen anti-inflammatory diet (GrAID) or ingest an ileocolonic-delivered oral vitamin B2/B3/C capsule (ColoVit). The study consists of a 12-week controlled interventional phase, which proceeds to a 9-month observational follow-up phase in which patients allocated to the GrAID group will be requested to continue the intervention on their own accord. Household members of participating patients will be asked to participate in the trial as healthy subjects and are allocated to the same group as their peer. The primary study outcome for patients is the change in FCal level from baseline. The primary outcome for household members is the change in gut microbial composition, which is set as secondary outcome for patients.Ethics and dissemination The protocol has been approved by the Institutional Review Board of the Stichting Beoordeling Ethiek Biomedisch Onderzoek in Assen, the Netherlands. Written informed consent will be obtained from all participants. Results will be disseminated through peer-reviewed journals and conference presentations.Trial registration number NCT04913467

    Calmodulin/CaMKII inhibition improves intercellular communication and impulse propagation in the heart and is antiarrhythmic under conditions when fibrosis is absent

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    Aim In healthy hearts, ventricular gap junctions are mainly composed by connexin43 (Cx43) and localize in the intercalated disc, enabling appropriate electrical coupling. In diseased hearts, Cx43 is heterogeneously down-regulated, whereas activity of calmodulin/calcium-calmodulin protein kinase II (CaM/CaMKII) signalling increases. It is unclear if CaM/CaMKII affects Cx43 expression/localization or impulse propagation. We analysed different models to assess this. Methods and results AC3-I mice with CaMKII genetically inhibited were subjected to pressure overload (16 weeks, TAC vs. sham). Optical and epicardial mapping was performed on Langendorff-perfused rabbit and AC3-I hearts, respectively. Cx43 subcellular distribution from rabbit/mouse ventricles was evaluated by immunoblot after Triton X-100-based fractionation. In mice with constitutively reduced CaMKII activity (AC3-I), conduction velocity (CV) was augmented (n = 11, P <0.01 vs. WT); in AC3-I, CV was preserved after TAC, in contrast to a reduction seen in TAC-WT mice (-20%). Cx43 expression was preserved after TAC in AC3-I mice, though arrhythmias and fibrosis were still present. In rabbits, W7 (CaM inhibitor, 10 ÎŒM) increased CV (6-13%, n= 6, P<0.05), while susceptibility to arrhythmias decreased. Immunoconfocal microscopy revealed enlarged Cx43 cluster sizes at intercalated discs of those hearts. Total Cx43 did not change by W7 (n= 4), whereas Triton X-100 insoluble Cx43 increased (+21%, n= 4, P<0.01). Similar findings were obtained in AC3-I mouse hearts when compared with control, and in cultured dog cardiomyocytes. Functional implication was shown through increased intercellular coupling in cultured neonatal rat cardiomyocytes. Conclusion Both acute and chronic CaM/CaMKII inhibition improves conduction characteristics and enhances localization of Cx43 in the intercalated disc. In the absence of fibrosis, this reduced the susceptibility for arrhythmias

    QURATOR: Innovative technologies for content and data curation

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    In all domains and sectors, the demand for intelligent systems to support the processing and generation of digital content is rapidly increasing. The availability of vast amounts of content and the pressure to publish new content quickly and in rapid succession requires faster, more efficient and smarter processing and generation methods. With a consortium of ten partners from research and industry and a broad range of expertise in AI, Machine Learning and Language Technologies, the QURATOR project, funded by the German Federal Ministry of Education and Research, develops a sustainable and innovative technology platform that provides services to support knowledge workers in various industries to address the challenges they face when curating digital content. The project’s vision and ambition is to establish an ecosystem for content curation technologies that significantly pushes the current state of the art and transforms its region, the metropolitan area Berlin-Brandenburg, into a global centre of excellence for curation technologies

    Increased fecal calprotectin levels in Crohn's disease correlate with elevated serum Th1- and Th17-associated cytokines

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    BACKGROUND: Patient-reported symptoms and endoscopic disease activity do not correlate well in Crohn's disease (CD). This warrants the need for reliable biomarkers to early detect active intestinal inflammation. Currently, the fecal calprotectin level is the most commonly used biomarker for inflammatory activity in CD. However, the diagnostic accuracy of the fecal calprotectin level is not fully efficacious and diagnosis may be further improved by the identification of other biomarkers for active CD. Here, we studied the association of a variety of serum disease markers with fecal calprotectin levels in CD patients. METHODS: 39 CD patients were included and subdivided into 'normal' (defined as 200 mg/kg feces) fecal calprotectin level groups. Serum levels of 37 different cytokines, chemokines and markers for angiogenesis and vascular injury were quantified by an electrochemiluminescence multiplex assay (V-PLEX Human Biomarker 40-Plex Kit of Meso Scale Discovery Âź). Correlations between individual biomarkers and the fecal calprotectin level were assessed using Spearman's correlation coefficient (ρ). RESULTS: A highly significant positive correlation was observed between the pro-inflammatory serum cytokines IFN-Îł and CRP and fecal calprotectin levels (P < 0.01). Moreover, fecal calprotectin levels showed a significant positive correlation with IL-6, TNF-ÎČ, SAA and IL-17A (P < 0.05). CONCLUSION: We show that a positive correlation exists between multiple serum Th1- and Th17-associated cytokines and the fecal calprotectin level. These cytokines and CRP may serve as additional biomarkers for determining disease activity and evaluating treatment response in CD. Ultimately, this may result in more efficient treatment of active disease in CD patients and prevention of complications

    Women receiving massive transfusion due to postpartum hemorrhage: A comparison over time between two nationwide cohort studies

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    Introduction Incidence of massive transfusion after birth was high in the Netherlands between 2004 and 2006 compared with other high-income countries. This study investigated incidence, causes, management and outcome of women receiving massive transfusion due to postpartum hemorrhage in the Netherlands in more recent years. Material and methods Data for all pregnant women who received eight or more units of packed red blood cells from a gestational age of 20 weeks and within the first 24 hours after childbirth, during 2011 and 2012, were obtained from a nationwide retrospective cohort study, including 61 hospitals with a maternity unit in the Netherlands. Results Incidence of massive transfusion due to postpartum hemorrhage decreased to 65 per 100 000 births (95% CI 56-75) between 2011 and 2012, from 91 per 100 000 births (95% CI 81-101) between 2004 and 2006, while median blood loss increased from 4500 mL (interquartile range 3250-6000) to 6000 mL (interquartile range 4500-8000). Uterine atony remained the leading cause of hemorrhage. Thirty percent (53/176) underwent peripartum hysterectomy between 2011 and 2012, compared with 25% (83/327) between 2004 and 2006. Case fatality rate for women who received massive transfusion due to postpartum hemorrhage was 2.3% (4/176) between 2011 and 2012, compared with 0.9% (3/327) between 2004 and 2006. Conclusions The incidence of postpartum hemorrhage with massive transfusion decreased in the Netherlands between both time frames, but remained an important cause of maternal mortality and morbidity, including peripartum hysterectomy. National surveillance of maternal morbidity and mortality due to postpartum hemorrhage through an improved and continuous registration with confidential enquiries may lead to the identification of clear improvements of maternal care
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