20 research outputs found

    Discovery of novel CSF biomarkers to predict progression in dementia using machine learning

    Get PDF
    Providing an accurate prognosis for individual dementia patients remains a challenge since they greatly differ in rates of cognitive decline. In this study, we used machine learning techniques with the aim to identify cerebrospinal fluid (CSF) biomarkers that predict the rate of cognitive decline within dementia patients. First, longitudinal mini-mental state examination scores (MMSE) of 210 dementia patients were used to create fast and slow progression groups. Second, we trained random forest classifiers on CSF proteomic profiles and obtained a well-performing prediction model for the progression group (ROC-AUC = 0.82). As a third step, Shapley values and Gini feature importance measures were used to interpret the model performance and identify top biomarker candidates for predicting the rate of cognitive decline. Finally, we explored the potential for each of the 20 top candidates in internal sensitivity analyses. TNFRSF4 and TGF [Formula: see text]-1 emerged as the top markers, being lower in fast-progressing patients compared to slow-progressing patients. Proteins of which a low concentration was associated with fast progression were enriched for cell signalling and immune response pathways. None of our top markers stood out as strong individual predictors of subsequent cognitive decline. This could be explained by small effect sizes per protein and biological heterogeneity among dementia patients. Taken together, this study presents a novel progression biomarker identification framework and protein leads for personalised prediction of cognitive decline in dementia

    An Evaluation of the COVID-19 Pandemic and Perceived Social Distancing Policies in Relation to Planning, Selecting, and Preparing Healthy Meals: An Observational Study in 38 Countries Worldwide

    Get PDF
    Objectives: To examine changes in planning, selecting, and preparing healthy foods in relation to personal factors (time, money, stress) and social distancing policies during the COVID-19 crisis. Methods: Using cross-sectional online surveys collected in 38 countries worldwide in April-June 2020 (N = 37,207, Mage 36.7 SD 14.8, 77% women), we compared changes in food literacy behaviors to changes in personal factors and social distancing policies, using hierarchical multiple regression analyses controlling for sociodemographic variables. Results: Increases in planning (4.7 SD 1.3, 4.9 SD 1.3), selecting (3.6 SD 1.7, 3.7 SD 1.7), and preparing (4.6 SD 1.2, 4.7 SD 1.3) healthy foods were found for women and men, and positively related to perceived time availability and stay-at-home policies. Psychological distress was a barrier for women, and an enabler for men. Financial stress was a barrier and enabler depending on various sociodemographic variables (all p < 0.01). Conclusion: Stay-at-home policies and feelings of having more time during COVID-19 seem to have improved food literacy. Stress and other social distancing policies relate to food literacy in more complex ways, highlighting the necessity of a health equity lens. Copyright 2021 De Backer, Teunissen, Cuykx, Decorte, Pabian, Gerritsen, Matthys, Al Sabbah, Van Royen and the Corona Cooking Survey Study Group.This research was funded by the Research Foundation Flanders (G047518N) and Flanders Innovation and Entrepreneurship (HBC.2018.0397). These funding sources had no role in the design of the study, the analysis and interpretation of the data or the writing of, nor the decision to publish the manuscript.Scopu

    Barriers and facilitators to the timely diagnosis of endometriosis in primary care in the Netherlands

    No full text
    Contains fulltext : 220866.pdf (Publisher’s version ) (Open Access)BACKGROUND: Endometriosis is an invalidating gynaecological condition in women of reproductive age, and a frequent cause of infertility. Unfortunately, the condition is characterized by a long interval between onset of symptoms and diagnosis. GPs in the Netherlands are educated to provide basic gynaecological care and serve as gatekeepers for specialist medical care. Therefore, it is of great importance that they recognize signs and symptoms possibly caused by endometriosis to initiate adequate actions. OBJECTIVE: The main objective of this study was to identify barriers and facilitators to the timely diagnosis of endometriosis from the GPs' perspective. METHODS: Semi-structured focus group discussions with GPs were organized throughout the Netherlands. The participants were encouraged to brainstorm about their perspective on daily practice regarding endometriosis and suggestions for interventions to enable early diagnosis and treatment. Analysis was based on grounded theory methodology. RESULTS: Forty-three GPs participated in six focus groups. Analysis of the transcripts revealed relevant determinants of practice in four main themes: professionals' experience and competence, patient characteristics, guideline factors and professional collaboration. A lack of knowledge and awareness appeared to result in a low priority for establishing the diagnosis of endometriosis, especially in young women. Infertility, patient engagement and a recent serious case or training facilitated referral. CONCLUSION: Several factors in daily primary health care contribute to the diagnostic delay in endometriosis. Future interventions to reduce this delay may be aimed at increasing awareness by means of education, incorporating the subject into national clinical guidelines and improvements in interdisciplinary collaboration

    Supramolecular interactions between catalytic species allow rational control over reaction kinetics

    No full text
    The adaptivity of biological reaction networks largely arises through non-covalent regulation of catalysts' activity. Such type of catalyst control is still nascent in synthetic chemical networks and thereby hampers their ability to display life-like behavior. Here, we report a bio-inspired system in which non-covalent interactions between two complementary phase-transfer catalysts are used to regulate reaction kinetics. While one catalyst gives bimolecular kinetics, the second displays autoinductive feedback, resulting in sigmoidal kinetics. When both catalysts are combined, the interactions between them allow rational control over the shape of the kinetic curves. Computational models are used to gain insight into the structure, interplay, and activity of each catalytic species, and the scope of the system is examined by optimizing the linearity of the kinetic curves. Combined, our findings highlight the effectiveness of regulating reaction kinetics using non-covalent catalyst interactions, but also emphasize the risk for unforeseen catalytic contributions in complex systems and the necessity to combine detailed experiments with kinetic modelling

    Optimizing Patient Care and Research: The Amsterdam Dementia Cohort

    No full text
    Since its opening in 2000, patient care and research go hand in hand at the Alzheimer center of the VU University Medical Center, both organized in such a way that they mutually strengthen each other. Our mission is to give patients a voice by lifting the stigma on dementia, to find new diagnostic and treatment strategies, and, ultimately, to cure diseases that cause dementia. Our healthcare pathway is uniquely designed to accommodate all necessary investigations for the diagnostic work-up of dementia in one day (one-stop shop). A second unique feature is that research has been fully integrated in the healthcare pathway. The resulting Amsterdam Dementia Cohort now includes over 4000 patients, and for the majority of these, we have MRI, EEG, blood (serum, plasma), DNA, and CSF available. The Amsterdam Dementia Cohort forms the basis of much of our research, which focuses on four major research lines: 1) variability in manifestation, 2) early diagnosis, 3) vascular factors, and 4) interventions. By answering research questions closely related to clinical practice, the results of our research can be looped back to improve clinical work-up for our patients

    Age- and disease-specific reference values for neurofilament light presented in an online interactive support interface

    No full text
    Interpretation of axonal damage biomarker Neurofilament Light chain (NfL) concentrations is difficult due to the lack of age-specific and disease-specific reference values. We here developed an interactive interface to support interpretation of NfL results in human body fluids. We used NfL values of 1698 individuals without a neurological disorder, aged 19-85 years, and patients with MS and dementias. Percentile regression estimates per diagnosis populate interactive graphs, alongside NfL background information (available on: https:// mybiomarkers.shinyapps.io/Neurofilament). This accessible interface provides reference for interpretation of the individual patient results for clinicians. It showcases an adaptable method to support interpretation of age-dependent biomarkers in neurology.Genetics of disease, diagnosis and treatmen

    Protein disulfide isomerases as CSF biomarkers for the neuronal response to tau pathology

    No full text
    IntroductionCerebrospinal fluid (CSF) biomarkers for specific cellular disease processes are lacking for tauopathies. In this translational study we aimed to identify CSF biomarkers reflecting early tau pathology-associated unfolded protein response (UPR) activation. MethodsWe employed mass spectrometry proteomics and targeted immunoanalysis in a combination of biomarker discovery in primary mouse neurons in vitro and validation in patient CSF from two independent large multicentre cohorts (EMIF-AD MBD, n = 310; PRIDE, n = 771). ResultsFirst, we identify members of the protein disulfide isomerase (PDI) family in the neuronal UPR-activated secretome and validate secretion upon tau aggregation in vitro. Next, we demonstrate that PDIA1 and PDIA3 levels correlate with total- and phosphorylated-tau levels in CSF. PDIA1 levels are increased in CSF from AD patients compared to controls and patients with tau-unrelated frontotemporal and Lewy body dementia (LBD). HighlightsNeuronal unfolded protein response (UPR) activation induces the secretion of protein disulfide isomerases (PDIs) in vitro.PDIA1 is secreted upon tau aggregation in neurons in vitro.PDIA1 and PDIA3 levels correlate with total and phosphorylated tau levels in CSF.PDIA1 levels are increased in CSF from Alzheimer's disease (AD) patients compared to controls.PDIA1 levels are not increased in CSF from tau-unrelated frontotemporal dementia (FTD) and Lewy body dementia (LBD) patients

    CSF proteome profiling across the Alzheimer's disease spectrum reflects the multifactorial nature of the disease and identifies specific biomarker panels

    No full text
    Development of disease-modifying therapies against Alzheimer's disease (AD) requires biomarkers reflecting the diverse pathological pathways specific for AD. We measured 665 proteins in 797 cerebrospinal fluid (CSF) samples from patients with mild cognitive impairment with abnormal amyloid (MCI(A beta+): n = 50), AD-dementia (n = 230), non-AD dementias (n = 322) and cognitively unimpaired controls (n = 195) using proximity ligation-based immunoassays. Here we identified >100 CSF proteins dysregulated in MCI(A beta+) or AD compared to controls or non-AD dementias. Proteins dysregulated in MCI(A beta+) were primarily related to protein catabolism, energy metabolism and oxidative stress, whereas those specifically dysregulated in AD dementia were related to cell remodeling, vascular function and immune system. Classification modeling unveiled biomarker panels discriminating clinical groups with high accuracies (area under the curve (AUC): 0.85-0.99), which were translated into custom multiplex assays and validated in external and independent cohorts (AUC: 0.8-0.99). Overall, this study provides novel pathophysiological leads delineating the multifactorial nature of AD and potential biomarker tools for diagnostic settings or clinical trials.This study identifies CSF proteins specifically dysregulated along the AD continuum that reflect the multifactorial nature of disease progression. Some of these CSF proteins were used to build biomarker panels with high diagnostic accuracies
    corecore