| 1. |
- Sweeney, M. D., et al.
(författare)
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Vascular dysfunction-The disregarded partner of Alzheimer's disease
- 2019
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:1, s. 158-167
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Tidskriftsartikel (refereegranskat)abstract
- Increasing evidence recognizes Alzheimer's disease (AD) as a multifactorial and heterogeneous disease with multiple contributors to its pathophysiology, including vascular dysfunction. The recently updated AD Research Framework put forth by the National Institute on Aging-Alzheimer's Association describes a biomarker-based pathologic definition of AD focused on amyloid, tau, and neuronal injury. In response to this article, here we first discussed evidence that vascular dysfunction is an important early event in AD pathophysiology. Next, we examined various imaging sequences that could be easily implemented to evaluate different types of vascular dysfunction associated with, and/or contributing to, AD pathophysiology, including changes in blood-brain barrier integrity and cerebral blood flow. Vascular imaging biomarkers of small vessel disease of the brain, which is responsible for >50% of dementia worldwide, including AD, are already established, well characterized, and easy to recognize. We suggest that these vascular biomarkers should be incorporated into the AD Research Framework to gain a better understanding of AD pathophysiology and aid in treatment efforts. (C) 2018 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
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| 2. |
- Chelban, V., et al.
(författare)
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Neurofilament light levels predict clinical progression and death in multiple system atrophy
- 2022
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 145:12, s. 4398-4408
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Tidskriftsartikel (refereegranskat)abstract
- In this large multiple system atrophy cohort, Chelban et al. show that plasma NfL correlates with clinical disease severity, progression and prognosis, and could help inform patient stratification and monitor treatment responses in future trials of putative disease-modifying agents. Disease-modifying treatments are currently being trialled in multiple system atrophy. Approaches based solely on clinical measures are challenged by heterogeneity of phenotype and pathogenic complexity. Neurofilament light chain protein has been explored as a reliable biomarker in several neurodegenerative disorders but data on multiple system atrophy have been limited. Therefore, neurofilament light chain is not yet routinely used as an outcome measure in multiple system atrophy. We aimed to comprehensively investigate the role and dynamics of neurofilament light chain in multiple system atrophy combined with cross-sectional and longitudinal clinical and imaging scales and for subject trial selection. In this cohort study, we recruited cross-sectional and longitudinal cases in a multicentre European set-up. Plasma and CSF neurofilament light chain concentrations were measured at baseline from 212 multiple system atrophy cases, annually for a mean period of 2 years in 44 multiple system atrophy patients in conjunction with clinical, neuropsychological and MRI brain assessments. Baseline neurofilament light chain characteristics were compared between groups. Cox regression was used to assess survival; receiver operating characteristic analysis to assess the ability of neurofilament light chain to distinguish between multiple system atrophy patients and healthy controls. Multivariate linear mixed-effects models were used to analyse longitudinal neurofilament light chain changes and correlated with clinical and imaging parameters. Polynomial models were used to determine the differential trajectories of neurofilament light chain in multiple system atrophy. We estimated sample sizes for trials aiming to decrease neurofilament light chain levels. We show that in multiple system atrophy, baseline plasma neurofilament light chain levels were better predictors of clinical progression, survival and degree of brain atrophy than the neurofilament light chain rate of change. Comparative analysis of multiple system atrophy progression over the course of disease, using plasma neurofilament light chain and clinical rating scales, indicated that neurofilament light chain levels rise as the motor symptoms progress, followed by deceleration in advanced stages. Sample size prediction suggested that significantly lower trial participant numbers would be needed to demonstrate treatment effects when incorporating plasma neurofilament light chain values into multiple system atrophy clinical trials in comparison to clinical measures alone. In conclusion, neurofilament light chain correlates with clinical disease severity, progression and prognosis in multiple system atrophy. Combined with clinical and imaging analysis, neurofilament light chain can inform patient stratification and serve as a reliable biomarker of treatment response in future multiple system atrophy trials of putative disease-modifying agents.
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| 3. |
- Scahill, R. I., et al.
(författare)
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Biological and clinical characteristics of gene carriers far from predicted onset in the Huntington?s disease Young Adult Study (HD-YAS): a cross-sectional analysis
- 2020
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Ingår i: Lancet Neurology. - : Elsevier BV. - 1474-4422. ; 19:6, s. 502-512
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Tidskriftsartikel (refereegranskat)abstract
- Background Disease-modifying treatments are in development for Huntington's disease; crucial to their success is to identify a timepoint in a patient's life when there is a measurable biomarker of early neurodegeneration while clinical function is still intact. We aimed to identify this timepoint in a novel cohort of young adult premanifest Huntington's disease gene carriers (preHD) far from predicted clinical symptom onset. Methods We did the Huntington's disease Young Adult Study (HD-YAS) in the UK. We recruited young adults with preHD and controls matched for age, education, and sex to ensure each group had at least 60 participants with imaging data, accounting for scan fails. Controls either had a family history of Huntington's disease but a negative genetic test, or no known family history of Huntington's disease. All participants underwent detailed neuropsychiatric and cognitive assessments, including tests from the Cambridge Neuropsychological Test Automated Battery and a battery assessing emotion, motivation, impulsivity and social cognition (EMOTICOM). Imaging (done for all participants without contraindications) included volumetric MRI, diffusion imaging, and multiparametric mapping. Biofluid markers of neuronal health were examined using blood and CSF collection. We did a cross-sectional analysis using general least-squares linear models to assess group differences and associations with age and CAG length, relating to predicted years to clinical onset. Results were corrected for multiple comparisons using the false discovery rate (FDR), with FDR <0.05 deemed a significant result. Findings Data were obtained between Aug 2, 2017, and April 25, 2019. We recruited 64 young adults with preHD and 67 controls. Mean ages of participants were 29.0 years (SD 5.6) and 29.1 years (5.7) in the preHD and control groups, respectively. We noted no significant evidence of cognitive or psychiatric impairment in preHD participants 23.6 years (SD 5.8) from predicted onset (FDR 0.22-0.87 for cognitive measures, 0.31-0.91 for neuropsychiatric measures). The preHD cohort had slightly smaller putamen volumes (FDR=0.03), but this did not appear to be closely related to predicted years to onset (FDR=0.54). There were no group differences in other brain imaging measures (FDR >0.16). CSF neurofilament light protein (NfL), plasma NfL, and CSF YKL-40 were elevated in this far-from-onset preHD cohort compared with controls (FDR<0.0001, =0.01, and =0.03, respectively). CSF NfL elevations were more likely in individuals closer to expected clinical onset (FDR <0.0001). Interpretation We report normal brain function yet a rise in sensitive measures of neurodegeneration in a preHD cohort approximately 24 years from predicted clinical onset. CSF NfL appears to be a more sensitive measure than plasma NfL to monitor disease progression. This preHD cohort is one of the earliest yet studied, and our findings could be used to inform decisions about when to initiate a potential future intervention to delay or prevent further neurodegeneration while function is intact.
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| 4. |
- Keshavan, A., et al.
(författare)
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Concordance of csf measures of alzheimer’s pathology with amyloid pet status in a preclinical cohort: A comparison of lumipulse and established immunoassays
- 2021
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Ingår i: Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring. - : Wiley. - 2352-8729. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: We assessed the concordance of cerebrospinal fluid (CSF) amyloid beta (Aβ) and tau measured on the fully automated Lumipulse platform with presymptomatic Alzheimer’s disease (AD) pathology on amyloid positron emission tomography (PET). METHODS: In 72 individuals from the Insight 46 study, CSF Aβ40, Aβ42, total tau (t-tau), and phosphorylated tau at site 181 (p-tau181) were measured using Lumipulse, INNOTEST, and Meso Scale Discovery (MSD) assays and inter-platform Pearson correlations derived. Lumipulse Aβ42 measures were adjusted to incorporate standardization to certified reference materials. Logistic regressions and receiver operating characteristics analysis generated CSF cut-points optimizing concordance with18F florbetapir amyloid PET status (n = 63). RESULTS: Measurements of CSF Aβ, p-tau181, and their ratios correlated well across platforms (r 0.84 to 0.94, P < .0001); those of t-tau and t-tau/Aβ42 correlated moderately (r 0.57 to 0.79, P < .0001). The best concordance with amyloid PET (100% sensitivity and 94% specificity) was afforded by cut-points of 0.075 for Lumipulse Aβ42/Aβ40, 0.087 for MSD Aβ42/Aβ40 and 17.3 for Lumipulse Aβ42/p-tau181. DISCUSSION: The Lumipulse platform provides comparable sensitivity and specificity to established CSF immunoassays in identifying pre-symptomatic AD pathology. © 2020 The Authors.
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| 5. |
- Wagen, Aaron Z, et al.
(författare)
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Life course, genetic, and neuropathological associations with brain age in the 1946 British Birth Cohort: a population-based study.
- 2022
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Ingår i: The Lancet. Healthy longevity. - 2666-7568. ; 3:9
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Tidskriftsartikel (refereegranskat)abstract
- A neuroimaging-based biomarker termed the brain age is thought to reflect variability in the brain's ageing process and predict longevity. Using Insight 46, a unique narrow-age birth cohort, we aimed to examine potential drivers and correlates of brain age.Participants, born in a single week in 1946 in mainland Britain, have had 24 prospective waves of data collection to date, including MRI and amyloid PET imaging at approximately 70 years old. Using MRI data from a previously defined selection of this cohort, we derived brain-predicted age from an established machine-learning model (trained on 2001 healthy adults aged 18-90 years); subtracting this from chronological age (at time of assessment) gave the brain-predicted age difference (brain-PAD). We tested associations with data from early life, midlife, and late life, as well as rates of MRI-derived brain atrophy.Between May 28, 2015, and Jan 10, 2018, 502 individuals were assessed as part of Insight 46. We included 456 participants (225 female), with a mean chronological age of 70·7 years (SD 0·7; range 69·2 to 71·9). The mean brain-predicted age was 67·9 years (8·2, 46·3 to 94·3). Female sex was associated with a 5·4-year (95% CI 4·1 to 6·8) younger brain-PAD than male sex. An increase in brain-PAD was associated with increased cardiovascular risk at age 36 years (β=2·3 [95% CI 1·5 to 3·0]) and 69 years (β=2·6 [1·9 to 3·3]); increased cerebrovascular disease burden (1·9 [1·3 to 2·6]); lower cognitive performance (-1·3 [-2·4 to -0·2]); and increased serum neurofilament light concentration (1·2 [0·6 to 1·9]). Higher brain-PAD was associated with future hippocampal atrophy over the subsequent 2 years (0·003 mL/year [0·000 to 0·006] per 5-year increment in brain-PAD). Early-life factors did not relate to brain-PAD. Combining 12 metrics in a hierarchical partitioning model explained 33% of the variance in brain-PAD.Brain-PAD was associated with cardiovascular risk, and imaging and biochemical markers of neurodegeneration. These findings support brain-PAD as an integrative summary metric of brain health, reflecting multiple contributions to pathological brain ageing, and which might have prognostic utility.Alzheimer's Research UK, Medical Research Council Dementia Platforms UK, Selfridges Group Foundation, Wolfson Foundation, Wellcome Trust, Brain Research UK, Alzheimer's Association.
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| 6. |
- Bergström, Petra, et al.
(författare)
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Amyloid precursor protein expression and processing are differentially regulated during cortical neuron differentiation
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) and its cleavage product amyloid beta (A beta) have been thoroughly studied in Alzheimer's disease. However, APP also appears to be important for neuronal development. Differentiation of induced pluripotent stem cells (iPSCs) towards cortical neurons enables in vitro mechanistic studies on human neuronal development. Here, we investigated expression and proteolytic processing of APP during differentiation of human iPSCs towards cortical neurons over a 100-day period. APP expression remained stable during neuronal differentiation, whereas APP processing changed. alpha-Cleaved soluble APP (sAPP alpha) was secreted early during differentiation, from neuronal progenitors, while beta-cleaved soluble APP (sAPP beta) was first secreted after deep-layer neurons had formed. Short A beta peptides, including A beta 1-15/16, peaked during the progenitor stage, while processing shifted towards longer peptides, such as A beta 1-40/42, when post-mitotic neurons appeared. This indicates that APP processing is regulated throughout differentiation of cortical neurons and that amyloidogenic APP processing, as reflected by A beta 1-40/42, is associated with mature neuronal phenotypes.
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| 7. |
- Engel, Katja, et al.
(författare)
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Meeting Report : 1st International Functional Metagenomics Workshop May 7-8, 2012, St. Jacobs, Ontario, Canada
- 2013
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Ingår i: Standards in Genomic Sciences. - : Springer Science and Business Media LLC. - 1944-3277. ; 8:1, s. 106-111
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This report summarizes the events of the 1st International Functional Metagenomics Workshop. The workshop was held on May 7 and 8, 2012, in St. Jacobs, Ontario, Canada and was focused on building an international functional metagenomics community, exploring strategic research areas, and identifying opportunities for future collaboration and funding. The workshop was initiated by researchers at the University of Waterloo with support from the Ontario Genomics Institute (OGI), Natural Sciences and Engineering Research Council of Canada (NSERC) and the University of Waterloo.
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| 8. |
- Gaze, William H, et al.
(författare)
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Influence of humans on evolution and mobilization of environmental antibiotic resistome.
- 2013
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Ingår i: Emerging infectious diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6059 .- 1080-6040. ; 19:7
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Forskningsöversikt (refereegranskat)abstract
- The clinical failure of antimicrobial drugs that were previously effective in controlling infectious disease is a tragedy of increasing magnitude that gravely affects human health. This resistance by pathogens is often the endpoint of an evolutionary process that began billions of years ago in non-disease-causing microorganisms. This environmental resistome, its mobilization, and the conditions that facilitate its entry into human pathogens are at the heart of the current public health crisis in antibiotic resistance. Understanding the origins, evolution, and mechanisms of transfer of resistance elements is vital to our ability to adequately address this public health issue.
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| 9. |
- Larsson, D. G. Joakim, 1969, et al.
(författare)
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Critical knowledge gaps and research needs related to the environmental dimensions of antibiotic resistance
- 2018
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 117, s. 132-138
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Forskningsöversikt (refereegranskat)abstract
- There is growing understanding that the environment plays an important role both in the transmission of antibiotic resistant pathogens and in their evolution. Accordingly, researchers and stakeholders world-wide seek to further explore the mechanisms and drivers involved, quantify risks and identify suitable interventions. There is a clear value in establishing research needs and coordinating efforts within and across nations in order to best tackle this global challenge. At an international workshop in late September 2017, scientists from 14 countries with expertise on the environmental dimensions of antibiotic resistance gathered to define critical knowledge gaps. Four key areas were identified where research is urgently needed: 1) the relative contributions of different sources of antibiotics and antibiotic resistant bacteria into the environment; 2) the role of the environment, and particularly anthropogenic inputs, in the evolution of resistance; 3) the overall human and animal health impacts caused by exposure to environmental resistant bacteria; and 4) the efficacy and feasibility of different technological, social, economic and behavioral interventions to mitigate environmental antibiotic resistance.(1)
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| 10. |
- Lashley, T., et al.
(författare)
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Molecular biomarkers of Alzheimer's disease: progress and prospects
- 2018
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Ingår i: Disease Models & Mechanisms. - : The Company of Biologists. - 1754-8403 .- 1754-8411. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- The neurodegenerative disorder Alzheimer's disease is characterised by the formation of beta-amyloid plaques and neurofibrillary tangles in the brain parenchyma, which cause synapse and neuronal loss. This leads to clinical symptoms, such as progressive memory deficits. Clinically, these pathological changes can be detected in the cerebrospinal fluid and with brain imaging, although reliable blood tests for plaque and tangle pathologies remain to be developed. Plaques and tangles often co-exist with other brain pathologies, including aggregates of transactive response DNA-binding protein 43 and Lewy bodies, but the extent to which these contribute to the severity of Alzheimer's disease is currently unknown. In this 'At a glance' article and poster, we summarise the molecular biornarkers that are being developed to detect Alzheimer's disease and its related pathologies. We also highlight the biornarkers that are currently in clinical use and include a critical appraisal of the challenges associated with applying these biornarkers for diagnostic and prognostic purposes of Alzheimer's disease and related neurodegenerative disorders, also in their prodromal clinical phases.
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| 11. |
- Stevenson, Sean R., et al.
(författare)
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Genetic Analysis of Physcomitrella patens Identifies ABSCISIC ACID NON-RESPONSIVE, a Regulator of ABA Responses Unique to Basal Land Plants and Required for Desiccation Tolerance
- 2016
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 28:6, s. 1310-1327
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Tidskriftsartikel (refereegranskat)abstract
- The anatomically simple plants that first colonized land must have acquired molecular and biochemical adaptations to drought stress. Abscisic acid (ABA) coordinates responses leading to desiccation tolerance in all land plants. We identified ABA nonresponsive mutants in the model bryophyte Physcomitrella patens and genotyped a segregating population to map and identify the ABA NON-RESPONSIVE (ANR) gene encoding a modular protein kinase comprising an N-terminal PAS domain, a central EDR domain, and a C-terminal MAPKKK-like domain. anr mutants fail to accumulate dehydration tolerance-associated gene products in response to drought, ABA, or osmotic stress and do not acquire ABA-dependent desiccation tolerance. The crystal structure of the PAS domain, determined to 1.7-angstrom resolution, shows a conserved PAS-fold that dimerizes through a weak dimerization interface. Targeted mutagenesis of a conserved tryptophan residue within the PAS domain generates plants with ABA nonresponsive growth and strongly attenuated ABA-responsive gene expression, whereas deleting this domain retains a fully ABA-responsive phenotype. ANR orthologs are found in early-diverging land plant lineages and aquatic algae but are absent from more recently diverged vascular plants. We propose that ANR genes represent an ancestral adaptation that enabled drought stress survival of the first terrestrial colonizers but were lost during land plant evolution.
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| 12. |
- Toombs, J., et al.
(författare)
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Amyloid β peptides are differentially vulnerable to preanalytical surface exposure, an effect incompletely mitigated by the use of ratios
- 2018
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Ingår i: Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring. - : Wiley. - 2352-8729. ; 10, s. 311-321
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: We tested the hypothesis that the amyloid β (Aβ) peptide ratios are more stable than Aβ42 alone when biofluids are exposed to two preanalytical conditions known to modify measurable Aβ concentration. Methods: Human cerebrospinal fluid (CSF) and culture media (CM) from human cortical neurons were exposed to a series of volumes and polypropylene surfaces. Aβ42, Aβ40, and Aβ38 peptide concentrations were measured using a multiplexed electrochemiluminescence immunoassay. Data were analyzed using mixed models in R. Results: Decrease of measurable Aβ peptide concentrations was exaggerated in longer peptides, affecting the Aβ42:Aβ40 and Aβ42:Aβ38 ratios. However, the effect size of surface treatment was reduced in Aβ peptide ratios versus Aβ42 alone. For Aβ42:Aβ40, the effect was reduced by approximately 50% (volume) and 75% (transfer) as compared to Aβ42 alone. Discussion: Use of Aβ ratios, in conjunction with concentrations, may mitigate confounding factors and assist the clinical diagnostic process for Alzheimer's disease.
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| 13. |
- Wellington, H., et al.
(författare)
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CSF neurogranin or tau distinguish typical and atypical Alzheimer disease
- 2018
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Ingår i: Annals of Clinical and Translational Neurology. - : Wiley. - 2328-9503. ; 5:2, s. 162-171
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess whether high levels of cerebrospinal fluid neurogranin are found in atypical as well as typical Alzheimer's disease. Methods: Immunoassays were used to measure cerebrospinal fluid neurogranin in 114 participants including healthy controls (n=27), biomarker-proven amnestic Alzheimer's disease (n=68), and the atypical visual variant of Alzheimer's (n=19) according to international criteria. CSF total-tau, A beta 42, and neurofilament light concentrations were investigated using commercially available assays. All affected individuals had T1-weighted volumetric MR images available for analysis of whole and regional brain volumes. Associations between neurogranin, brain volumes, total-tau, A beta 42, and neurofilament light were assessed. Results: Median cerebrospinal fluid neurogranin concentrations were higher in typical and atypical Alzheimer's compared to controls (P<0.001 and P=0.005). Both neurogranin and total-tau concentrations, but not neurofilament light and A beta 42, were higher in typical Alzheimer's compared to atypical patients (P=0.004 and P=0.03). There were significant differences in the left hippocampus and right and left superior parietal lobules in atypical patients, which were larger (P=0.03) and smaller (P=0.001 and P<0.001), respectively, compared to typical patients. We found no evidence of associations between neurogranin and brain volumes but a strong association with total-tau (P<0.001) and a weaker association with neurofilament light (P=0.005). Interpretation: These results show significant differences in neurogranin and total-tau between typical and atypical patients, which may relate to factors other than disease topography. The differential relationships between neurogranin, total-tau and neurofilament light in the Alzheimer's variants, provide evidence for mechanistically distinct and coupled markers of neurodegeneration.
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| 14. |
- Williams, T., et al.
(författare)
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Serum neurofilament light and MRI predictors of cognitive decline in patients with secondary progressive multiple sclerosis: Analysis from the MS-STAT randomised controlled trial
- 2022
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Ingår i: Multiple Sclerosis Journal. - : SAGE Publications. - 1352-4585 .- 1477-0970. ; 28:12, s. 1913-1926
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cognitive impairment affects 50%-75% of people with secondary progressive multiple sclerosis (PwSPMS). Improving our ability to predict cognitive decline may facilitate earlier intervention. Objective: The main aim of this study was to assess the relationship between longitudinal changes in cognition and baseline serum neurofilament light chain (sNfL) in PwSPMS. In a multi-modal analysis, MRI variables were additionally included to determine if sNfL has predictive utility beyond that already established through MRI. Methods: Participants from the MS-STAT trial underwent a detailed neuropsychological test battery at baseline, 12 and 24 months. Linear mixed models were used to assess the relationships between cognition, sNfL, T2 lesion volume (T2LV) and normalised regional brain volumes. Results: Median age and Expanded Disability Status Score (EDSS) were 51 and 6.0. Each doubling of baseline sNfL was associated with a 0.010 [0.003-0.017] point per month faster decline in WASI Full Scale IQ Z-score (p = 0.008), independent of T2LV and normalised regional volumes. In contrast, lower baseline volume of the transverse temporal gyrus was associated with poorer current cognitive performance (0.362 [0.026-0.698] point reduction per mL, p = 0.035), but not change in cognition. The results were supported by secondary analyses on individual cognitive components. Conclusion: Elevated sNfL is associated with faster cognitive decline, independent of T2LV and regional normalised volumes.
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