61 research outputs found

    Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

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    The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Overview of physics results from NSTX

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    Uncovering the heterogeneity and temporal complexity of neurodegenerative diseases with Subtype and Stage Inference

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    The heterogeneity of neurodegenerative diseases is a key confound to disease understanding and treatment development, as study cohorts typically include multiple phenotypes on distinct disease trajectories. Here we introduce a machine-learning technique\u2014Subtype and Stage Inference (SuStaIn)\u2014able to uncover data-driven disease phenotypes with distinct temporal progression patterns, from widely available cross-sectional patient studies. Results from imaging studies in two neurodegenerative diseases reveal subgroups and their distinct trajectories of regional neurodegeneration. In genetic frontotemporal dementia, SuStaIn identifies genotypes from imaging alone, validating its ability to identify subtypes; further the technique reveals within-genotype heterogeneity. In Alzheimer\u2019s disease, SuStaIn uncovers three subtypes, uniquely characterising their temporal complexity. SuStaIn provides fine-grained patient stratification, which substantially enhances the ability to predict conversion between diagnostic categories over standard models that ignore subtype (p = 7.18 7 10 124 ) or temporal stage (p = 3.96 7 10 125 ). SuStaIn offers new promise for enabling disease subtype discovery and precision medicine

    Real-World Outcomes in Patients with Alk-Positive Non-Small Cell Lung Cancer Treated with Crizotinib

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    Background: Crizotinib has shown greater efficacy in clinical trials than chemotherapy in patients with anaplastic lymphoma kinase-positive (ALK+) non-small cell lung cancer (NSCLC), but little information is available on its use and outcomes in real-world settings. We therefore assessed treatment patterns and outcomes in ALK+ NSCLC patients treated with crizotinib in regular clinical practice. Methods: A retrospective medical record review was conducted in North America for adults with ALK+ NSCLC treated with crizotinib as first- or later-line therapy for metastatic disease between 1 August 2011 and 31 March 2013 (for the United States) or 1 May 2012 and 31 March 2013 (for Canada). Crizotinib-related trial enrollees were excluded. Descriptive analyses were conducted to assess treatment patterns and objective response rate (ORR). Progression-free survival (PFS) and overall survival (OS) were descriptively analyzed using Kaplan-Meier methods. Results: Data were extracted for 212 patients in the United States (n = 147) and Canada (n = 65). Mean (standard deviation [SD]) age was 58.9 (9.5) years, and 69% were male. Seventy-nine patients (37%) were deceased at record abstraction. Sixty-five percent (n = 137) initiated crizotinib as first-line therapy. Mean (SD) duration of crizotinib treatment was 8.7 (4.9) months. Objective response rate was 66% (69% for first-line recipients, 60% for second-/later-line). Median (95% CI) PFS and OS from crizotinib initiation were 9.5 (8.7, 10.1) and 23.4 (19.5, −) months, respectively. One- and two-year survival probabilities were 82% and 49%, respectively. One- and two-year survival probabilities were 82% and 49%, respectively. Conclusions: Outcomes for crizotinib recipients in this study align with previous trials, with ORR appearing more favourable in first-line recipients. Our findings indicate that crizotinib outcomes in clinical studies may translate to regular clinical practice
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