Background <5% of medulloblastoma patients survive following failure of contemporary radiation-based therapies. Understanding the molecular drivers of medulloblastoma relapse (rMB) will be essential to improve outcomes. Initial genome-wide investigations suggested significant genetic divergence of the relapsed disease. Methods We undertook large-scale integrated characterization of the molecular features of rMB - molecular subgroup, novel subtypes, copy number variation (CNV) and driver gene mutation. 119 rMBs were assessed in comparison with their paired diagnostic samples (n=107), alongside an independent reference cohort sampled at diagnosis (n=282). rMB events were investigated for association with outcome post-relapse in clinically-annotated patients (n=54). Results Significant genetic evolution occurred over disease-course; 40% of putative rMB drivers emerged at relapse and differed significantly between molecular subgroups. MBSHH Non-infant displayed significantly more chromosomal CNVs at relapse (TP53 mutation-associated). Relapsed MBGroup4 demonstrated the greatest genetic divergence, enriched for targetable (e.g. CDK amplifications) and novel (e.g. USH2A mutations) events. Importantly, many hallmark features of medulloblastoma were stable over time; novel subtypes (>90% of tumors) and established genetic drivers (e.g. SHH/WNT/P53 mutations; 60% of rMB events) were maintained from diagnosis. Critically, acquired and maintained rMB events converged on targetable pathways which were significantly enriched at relapse (e.g. DNA damage-signaling) and specific events (e.g. 3p loss) predicted survival post-relapse. Conclusions rMB is defined by the emergence of novel events and pathways, in concert with selective maintenance of established genetic drivers. Together, these define the actionable genetic landscape of rMB and provide a basis for improved clinical management and development of stratified therapeutics, across disease-course.
Recent expansions in the development and availability of three-dimensional printing (3Dp) have led to the uptake of this valuable and effective technology within the modern context of medical education. It is proposed that 3Dp is entirely appropriate for the creation of anatomical models for purposes of teaching and training due to the ability of this technology to produce accurate 3D physical representations based on a processed data set acquired from sources including magnetic resonance imaging (MRI) and computed tomography (CT). When investigating the currently available educational research with respect to 3Dp, it is important that the best evidence supporting the practical and theoretical benefits of this technology in teaching and training can be identified, while any obstacles to the effective implementation of 3Dp can also be determined. Here, literature describing recent primary research with respect to the capability and utility of 3Dp in anatomy and surgery have been explored in a narrative review. The impact on resources of implementing this technology within medical education have also been investigated. In order to emphasise wider applications in medicine, the role of 3Dp in medical practice and research have also been examined. To identify recent literature appropriate for this review published up to March 2017, suitable search terms were determined and applied using PubMed and results were judged against an established checklist. The research identified was then allocated with respect to the agreed topic areas of anatomy education, surgical training, medical usage and medical research. A student partnership approach was utilised for this review and the focus of the work was driven by undergraduate students in collaboration with anatomy and medical educators. Preliminary findings from this narrative review support the implementation of 3Dp in anatomy education and surgical training as a supplement to traditional learning approaches.
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Background: The 2019 novel coronavirus pandemic has generated concern from stroke specialist centres across the globe. Reductions in stroke admissions have been reported, despite many expecting an increase due to the pro-thrombotic nature of 2019 novel coronavirus. Aims: To assess the impact of the pandemic and subsequent lockdown on stroke admissions and transient ischaemic attack referrals at the Royal Victoria Infirmary, Newcastle-Upon-Tyne, and additionally on patient behaviours affecting modifiable risk factors or perspectives related to accessing healthcare. Methods: A single-centre retrospective data analysis was carried out on a “lockdown” cohort of suspected stroke patients admitted between 11 March to 26 May 2020 and a “pre-lockdown” cohort admitted in 2019. Differences in weekly admissions, weekly referrals, onset-to-presentation time and weekly thrombolysis cases were examined. Further analysis interrogated these cohorts separated by Bamford classification and stroke mimics (such as seizure/hemiplegic migraine/functional neurology). A binary-format questionnaire was separately administered to admitted patients from 15 April to 5 June 2020. Results: Significant reductions in weekly posterior circulation infarct (−43%, p = 0.017) and stroke-mimic (−47%, p < 0.001) admissions and weekly referrals diagnosed as non-transient ischaemic attack (−55%, p = 0.002) were observed in the lockdown cohort, with no differences in onset-to-presentation time. Over 25% of questionnaire respondents reported less physical activity, increased isolation and delaying their presentation due to the pandemic. Conclusions: This study provides evidence of reduced stroke-mimic and posterior circulation infarct admissions. Questionnaire findings suggest that patients need to be informed to ensure they appropriately seek medical advice. Significant communication at the stroke-primary care interface is needed to support referral pathways and management of modifiable risk factors.
Medulloblastoma relapse (rMB) occurs in 30–40% of patients and is almost universally fatal. Understanding the genomic landscape of rMB, and its relationship to disease characteristics at diagnosis, will be essential to underpin the development of improved therapeutic strategies, delivered at both diagnosis and relapse. Utilising NGS and Illumina DNA methylation arrays, we interrogated the molecular landscape of >100 rMBs, alongside matched diagnostic samples (n>80), encompassing molecular subgroup, novel subtypes, copy number (CNV) and mutational variants. Molecular subgroup and novel subtypes were stable over disease-course. The majority of genomic aberrations were also maintained (total arm-level CNVs at relapse, 60% maintained/40% acquired; deleterious/driver mutations, 75% maintained/25% acquired). Importantly, however, the landscape of alterations differed markedly at relapse, through both selective maintenance and acquisition of specific gene and pathway aberrations. For instance, we observed significant enrichment of subgroup-specific events at relapse, including focal CDK6/CDK14 amplifications (4/26 (15%) of MBGroup4) and CDKN2A/CDKN2B deletions (3/48 (6%) of MBSHH). In contrast, mutations in DNA damage response pathways were commonly enriched across all molecular subgroups, most significantly in MBSHH (~40% of rMBSHH; TP53, 9/36 (25%); ATM, 5/36 (14%)). Driver events in rMB are characterised by both selective maintenance and acquisition across disease-course, and together combine to define its actionable genetic landscape. Evaluation of their clinical and biological significance will be essential to establish their potential (i) as biomarkers to direct disease management and (ii) as a basis for therapeutic strategies targeted against medulloblastoma relapse.
Relapsed medulloblastoma (rMB) is treatment-resistant and fatal in ~95% of cases. The epigenetic features of rMB, and any role as drivers of disease relapse/treatment-resistance have yet to be investigated. We therefore developed a pipeline to identify differentially methylated CpGs (DM-CpGs) and regions (DMRs) in a paired-rMB cohort. Our paired-rMB cohort (n=61, relapsed tumours matched with diagnosis counterparts) with available Illumina Methylation 450K/850K microarray data was processed in R-Studio. The packages Limma and DMRcate were used to perform a paired differential methylation analysis on a filtered selection of array probes (n=335,767), identifying DM-CpGs and DMRs with a 5% FDR. DMRs were further retained if they had a maximum-Δβ of >0.2 and correlated with locus-specific gene expression in a separate paired DNA-methylation array/RNA-seq cohort from medulloblastoma diagnosis samples (n=202). Finally, we created univariable Cox models to assess the prognostic potential of DM-CpGs/DMRs in an independent survival cohort of medulloblastoma diagnosis samples (n=498). Across the paired-rMB cohort, there were few significant differential methylation events initially identified at relapse (n=258 DM-CpGs, n=32 DMRs). Upon sub-analysis by molecular group, MBGroup4 (n=18 pairs) alone yielded significant findings (n=189 DM-CpGs, n=26 DMRs). Most changes involved hypermethylation events detected at relapse. Multiple DM-CpGs identified at relapse were prognostic for both overall and event-free survival when assessed in our independent cohort (n=22 whole cohort, n=13 Group 4, BH-adjusted p<0.05). When applying the DMR filters, only the MBGroup4 DMRs passed the Δβ filter (n=18/26), with few correlating with gene expression (n=2, p<0.001), and none demonstrating prognostic significance. This pipeline facilitates exploration of the clinical relevance of epigenome-wide changes in a paired-rMB cohort. We highlight the potential prognostic significance of DM-CpGs, and future work will explore the potential functional role of candidate-genes associated with our DMRs, as novel drivers of rMB.
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