67 research outputs found
A novel, highly sensitive and specific biomarker for Niemann-Pick type C1 disease
Background Lysosomal storage disorders (LSDs), are a heterogeneous group of
rare disorders caused by defects in genes encoding for proteins involved in
the lysosomal degradation of macromolecules. They occur at a frequency of
about 1 in 5,000 live births, though recent neonatal screening suggests a
higher incidence. New treatment options for LSDs demand a rapid, early
diagnosis of LSDs if maximal clinical benefit is to be achieved. Methods Here,
we describe a novel, highly specific and sensitive biomarker for Niemann-Pick
Type C disease type 1 (NPC1), lyso-sphingomyelin-509. We cross-validate this
biomarker with cholestane-3β,5α,6β-triol and relative lysosomal volume. The
primary cohort for establishment of the biomarker contained 135 NPC1 patients,
66 NPC1 carriers, 241 patients with other LSDs and 46 healthy controls.
Results With a sensitivity of 100.0% and specificity of 91.0% a cut-off of 1.4
ng/ml was established. Comparison with cholestane-3β,5α,6β-triol and relative
acidic compartment volume measurements were carried out with a subset of 125
subjects. Both cholestane-3β,5α,6β-triol and lyso-Sphingomyelin-509 were
sufficient in establishing the diagnosis of NPC1 and correlated with disease
severity. Conclusion In summary, we have established a new biomarker for the
diagnosis of NPC1, and further studies will be conducted to assess correlation
to disease progress and monitoring treatment
Interaction of ARC and Daxx: a novel endogenous target to preserve motor function and cell loss after focal brain ischemia in mice
The aim of this study was to explore the signaling and neuroprotective effect of transactivator of transcription (TAT) protein transduction of the apoptosis repressor with CARD (ARC) in in vitro and in vivo models of cerebral ischemia in mice. In mice, transient focal cerebral ischemia reduced endogenousARCprotein in neurons in the ischemic striatum at early reperfusion time points, and in primary neuronal cultures, RNA interference resulted in greater neuronal susceptibility to oxygen glucose deprivation (OGD).TAT.ARC protein delivery led to a dose-dependent better survival after OGD. Infarct sizes 72 h after 60 min middle cerebral artery occlusion (MCAo) were on average 30±8% (mean±SD; p=0.005; T2-weighted MRI) smaller in TAT.ARC-treated mice (1ug intraventricularly during MCAo) compared with controls. TAT.ARC-treated mice showed better performance in the pole test compared with TAT.β-Gal-treated controls. Importantly, post-stroke treatment (3 h after MCAo) was still effective in affording reduced lesion volume by 20±7% (mean±SD; p˃0.05) and better functional outcome compared with controls. Delayed treatment in mice subjected to 30 min MCAo led to sustained neuroprotection and functional behavior benefits for at least 28 d. Functionally, TAT.ARC treatment inhibited DAXX–ASK1–JNK signaling in the ischemic brain. ARC interacts with DAXX in a CARD-dependent manner to block DAXX trafficking and ASK1–JNK activation. Our work identifies for the first time ARC–DAXX binding to block ASK1–JNK activation as an ARC-specific endogenous mechanism that interferes with neuronal cell death and ischemic brain injury. Delayed delivery of TAT.ARC may present a promising target for stroke therapy
Evaluation of C-terminal Agrin Fragment as a marker of muscle wasting in patients after acute stroke during early rehabilitation.
BACKGROUND
C-terminal Agrin Fragment (CAF) has been proposed as a novel biomarker for sarcopenia originating from the degeneration of the neuromuscular junctions. In patients with stroke muscle wasting is a common observation that predicts functional outcome. We aimed to evaluate agrin sub-fragment CAF22 as a marker of decreased muscle mass and physical performance in the early phase after acute stroke.
METHODS
Patients with acute ischaemic or haemorrhagic stroke (n = 123, mean age 70 ± 11 y, body mass index BMI 27.0 ± 4.9 kg/m(2)) admitted to inpatient rehabilitation were studied in comparison to 26 healthy controls of similar age and BMI. Functional assessments were performed at begin (23 ± 17 days post stroke) and at the end of the structured rehabilitation programme (49 ± 18 days post stroke) that included physical assessment, maximum hand grip strength, Rivermead motor assessment, and Barthel index. Body composition was assessed by bioelectrical impedance analysis (BIA). Serum levels of CAF22 were measured by ELISA.
RESULTS
CAF22 levels were elevated in stroke patients at admission (134.3 ± 52.3 pM) and showed incomplete recovery until discharge (118.2 ± 42.7 pM) compared to healthy controls (95.7 ± 31.8 pM, p < 0.001). Simple regression analyses revealed an association between CAF22 levels and parameters of physical performance, hand grip strength, and phase angle, a BIA derived measure of the muscle cellular integrity. Improvement of the handgrip strength of the paretic arm during rehabilitation was independently related to the recovery of CAF22 serum levels only in those patients who showed increased lean mass during the rehabilitation.
CONCLUSIONS
CAF22 serum profiles showed a dynamic elevation and recovery in the subacute phase after acute stroke. Further studies are needed to explore the potential of CAF22 as a serum marker to monitor the muscle status in patients after stroke
Transcranial direct current stimulation over multiple days improves learning and maintenance of a novel vocabulary
Introduction: Recently, growing interest emerged in the enhancement of human potential by means of non-invasive brain stimulation. In particular, anodal transcranial direct current stimulation (atDCS) has been shown to exert beneficial effects on motor and higher cognitive functions. However, the majority of transcranial direct current stimulation (tDCS) studies have assessed effects of single stimulation sessions that are mediated by transient neural modulation. Studies assessing the impact of multiple stimulation sessions on learning that may induce long-lasting behavioural and neural changes are scarce and have not yet been accomplished in the language domain in healthy individuals
Serum GFAP and NfL as disease severity and prognostic biomarkers in patients with aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder
BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is a frequently disabling neuroinflammatory syndrome with a relapsing course. Blood-based disease severity and prognostic biomarkers for NMOSD are a yet unmet clinical need. Here, we evaluated serum glial fibrillary acidic protein (sGFAP) and neurofilament light (sNfL) as disease severity and prognostic biomarkers in patients with aquaporin-4 immunoglobulin (Ig)G positive (AQP4-IgG(+)) NMOSD. METHODS: sGFAP and sNfL were determined by single-molecule array technology in a prospective cohort of 33 AQP4-IgG(+) patients with NMOSD, 32 of which were in clinical remission at study baseline. Sixteen myelin oligodendrocyte glycoprotein IgG-positive (MOG-IgG(+)) patients and 38 healthy persons were included as controls. Attacks were recorded in all AQP4-IgG(+) patients over a median observation period of 4.25 years. RESULTS: In patients with AQP4-IgG(+) NMOSD, median sGFAP (109.2 pg/ml) was non-significantly higher than in MOG-IgG(+) patients (81.1 pg/ml; p = 0.83) and healthy controls (67.7 pg/ml; p = 0.07); sNfL did not substantially differ between groups. Yet, in AQP4-IgG(+), but not MOG-IgG(+) patients, higher sGFAP was associated with worse clinical disability scores, including the Expanded Disability Status Scale (EDSS, standardized effect size = 1.30, p = 0.007) and Multiple Sclerosis Functional Composite (MSFC, standardized effect size = - 1.28, p = 0.01). While in AQP4-IgG(+), but not MOG-IgG(+) patients, baseline sGFAP and sNfL were positively associated (standardized effect size = 2.24, p = 0.001), higher sNfL was only non-significantly associated with worse EDSS (standardized effect size = 1.09, p = 0.15) and MSFC (standardized effect size = - 1.75, p = 0.06) in patients with AQP4-IgG(+) NMOSD. Patients with AQP4-IgG(+) NMOSD with sGFAP > 90 pg/ml at baseline had a shorter time to a future attack than those with sGFAP ≤ 90 pg/ml (adjusted hazard ratio [95% confidence interval] = 11.6 [1.3-105.6], p = 0.03). In contrast, baseline sNfL levels above the 75th age adjusted percentile were not associated with a shorter time to a future attack in patients with AQP4-IgG(+) NMOSD. CONCLUSION: These findings suggest a potential role for sGFAP as biomarker for disease severity and future disease activity in patients with AQP4-IgG(+) NMOSD in phases of clinical remission
FAIR-compliant clinical, radiomics and DICOM metadata of RIDER, interobserver, Lung1 and head-Neck1 TCIA collections
Purpose: One of the most frequently cited radiomics investigations showed that features automatically extracted from routine clinical images could be used in prognostic modeling. These images have
been made publicly accessible via The Cancer Imaging Archive (TCIA). There have been numerous
requests for additional explanatory metadata on the following datasets — RIDER, Interobserver,
Lung1, and Head–Neck1. To support repeatability, reproducibility, generalizability, and transparency
in radiomics research, we publish the subjects’ clinical data, extracted radiomics features, and digital
imaging and communications in medicine (DICOM) headers of these four datasets with descriptive
metadata, in order to be more compliant with findable, accessible, interoperable, and reusable (FAIR)
data management principles.
Acquisition and validation methods: Overall survival time intervals were updated using a national
citizens registry after internal ethics board approval. Spatial offsets of the primary gross tumor volume (GTV) regions of interest (ROIs) associated with the Lung1 CT series were improved on the
TCIA. GTV radiomics features were extracted using the open-source Ontology-Guided Radiomics
Analysis Workflow (O-RAW). We reshaped the output of O-RAW to map features and extraction settings to the latest version of Radiomics Ontology, so as to be consistent with the Image Biomarker
Standardization Initiative (IBSI). Digital imaging and communications in medicine metadata was
extracted using a research version of Semantic DICOM (SOHARD, GmbH, Fuerth; Germany). Subjects’ clinical data were described with metadata using the Radiation Oncology Ontology. All of the
above were published in Resource Descriptor Format (RDF), that is, triples. Example SPARQL
queries are shared with the reader to use on the online triples archive, which are intended to illustrate
how to exploit this data submission. Data format: The accumulated RDF data are publicly accessible through a SPARQL endpoint
where the triples are archived. The endpoint is remotely queried through a graph database web application at http://sparql.cancerdata.org. SPARQL queries are intrinsically federated, such that we can
efficiently cross-reference clinical, DICOM, and radiomics data within a single query, while being
agnostic to the original data format and coding system. The feder
Life course trajectories of alcohol consumption in the United Kingdom using longitudinal data from nine cohort studies.
Background Alcohol consumption patterns change across life and this is not fully captured in cross-sectional series data. Analysis of longitudinal data, with repeat alcohol measures, is necessary to reveal changes within the same individuals as they age. Such data are scarce and few studies are able to capture multiple decades of the life course. Therefore, we examined alcohol consumption trajectories, reporting both average weekly volume and frequency, using data from cohorts with repeated measures that cover different and overlapping periods of life.
Methods Data were from nine UK-based prospective cohorts with at least three repeated alcohol consumption measures on individuals (combined sample size of 59,397 with 174,666 alcohol observations), with data spanning from adolescence to very old age (90 years plus). Information on volume and frequency of drinking were harmonised across the cohorts. Predicted volume of alcohol by age was estimated using random effect multilevel models fitted to each cohort. Quadratic and cubic polynomial terms were used to describe non-linear age trajectories. Changes in drinking frequency by age were calculated from observed data within each cohort and then smoothed using locally weighted scatterplot smoothing. Models were fitted for men and women separately.
Results We found that, for men, mean consumption rose sharply during adolescence, peaked at around 25 years at 20 units per week, and then declined and plateaued during mid-life, before declining from around 60 years. A similar trajectory was seen for women, but with lower overall consumption (peak of around 7 to 8 units per week). Frequent drinking (daily or most days of the week) became more common during mid to older age, most notably among men, reaching above 50% of men.
Conclusions This is the first attempt to synthesise longitudinal data on alcohol consumption from several overlapping cohorts to represent the entire life course and illustrates the importance of recognising that this behaviour is dynamic. The aetiological findings from epidemiological studies using just one exposure measure of alcohol, as is typically done, should be treated with caution. Having a better understanding of how drinking changes with age may help design intervention strategies
Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke
Background and Objectives Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke. Methods We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18-59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS. Results We observed genome-wide significant associations of EOS with 2 variants in ABO, a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85-0.91) in EOS vs 0.96 (95% CI: 0.92-1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11-1.21) for EOS vs 1.05 (0.99-1.11) in LOS; p-values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS (p = 0.008). Discussion The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.Peer reviewe
Linking Results-Based Aid and Capacity Development Support: Conceptual and Practical Challenges
Causal mechanisms proposed for the Alcohol Harm Paradox - a systematic review
Background and Aims
The Alcohol Harm Paradox (AHP) posits that disadvantaged groups suffer from higher rates of alcohol-related harm compared with advantaged groups, despite reporting similar or lower levels of consumption on average. The causes of this relationship remain unclear. This study aimed to identify explanations proposed for the AHP. Secondary aims were to review the existing evidence for those explanations and investigate whether authors linked explanations to one another.
Methods
Systematic review. We searched MEDLINE (1946-January 2021), EMBASE (1974 – January 2021) and PsycINFO (1967 – January 2021), supplemented via manual searching of grey literature. Included papers either explored the causes of the AHP or investigated the relationship between alcohol consumption, alcohol-related harm, and socioeconomic position. Papers were set in Organisation for Economic Co-operation and Development high income countries. Explanations extracted for analysis could be evidenced in the empirical results or suggested by researchers in their narrative. Inductive thematic analysis was applied to group explanations.
Results
Seventy-nine papers met the inclusion criteria and initial coding revealed these papers contained 41 distinct explanations for the AHP. Following inductive thematic analysis, these explanations were grouped into 16 themes within six broad domains: Individual, Lifestyle, Contextual, Disadvantage, Upstream and Artefactual. Explanations related to risk behaviours, which fit within the Lifestyle domain, were the most frequently proposed (n=51) and analysed (n=21).
Conclusions
While there are many potential explanations for the Alcohol Harm Paradox, most research focuses on risk behaviours while other explanations lack empirical testing
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