Neurosciences Commons^™

Plasma Aβ42/40 Predicts Progression From Aβ-Amyloid Negative To Positive Pet Scans, Azadeh Feizpour, Vincent Doré, Pierrick Bourgeat, James D. Doecke, Rodrigo Canovas, Simon M. Laws, Tenielle Porter, Kun Huang, Christopher Fowler, Ralph N. Martins, Paul Maruff, Hamid R. Sohrabi, Michael W. Weiner, John C. Morris, Tammie L.S. Benzinger, Suzanne E. Schindler, Randall J. Bateman, Yan Li, Ovod Vitaliy, Larry Ward, Jurgen Mejan-Fripp, Colin L. Masters, Victor L. Villemagne, Christopher C. Rowe

Research outputs 2022 to 2026

Background The agreement between plasma Aβ42/40 and Aβ positron emission tomography (PET) is approximately 75 %, with ∼85 % of discrepancies due to positive plasma but negative PET results. It is unclear whether this reflects Aβ changes in plasma before PET-detectable. Objectives To assess the influence of Aβ42/40 positivity on risk of progression to Aβ PET positivity, and feasibility of using plasma Aβ42/40 tests to enrich a primary prevention trial. Design A prospective longitudinal cohort study. Setting Participants of Australian Imaging, Biomarkers and Lifestyle study (AIBL), Alzheimer’s Disease Neuroimaging Initiative (ADNI), and Open Access Series of Imaging Studies 3 (OASIS3). …

Exploring The Mechanisms Of Tanshinone Iia In The Treatment Of Intracranial Aneurysm Based On Network Pharmacology And Machine Learning, Wanqi Wang, Lois Balmer, Shaotao Weng

Research outputs 2022 to 2026

Background Intracranial aneurysm (IA) is a cerebrovascular disease with high mortality and limited treatment options. Tanshinone IIA (Tan IIA), a bioactive compound from Salvia miltiorrhiza , has shown vascular protective effects, but its mechanism in the treatment of IA remains unclear. Methods The GSE75436 dataset was used to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) was performed to identify disease-related modules. IA targets were obtained from GeneCards and the Comparative Toxicogenomics Database (CTD). Potential targets of Tan IIA were predicted using TCMSP, SwissTargetPrediction, and SymMap. KEGG enrichment analysis was conducted for DEGs, WGCNA modules, disease-related genes, …

Prevalence Of Dementia In Selected Middle East And North Africa (Mena) Countries: A Systematic Review And Meta-Analysis, Mohsen Sedighi, Mohammad Hasan Shahabi, Alireza Amanollahi, Khurshid Alam, Soudabeh Shemehsavar, Zahra Shirzadi, Serena Sabatini, Ahmad R. Khatoonabadi, Matthew Prina, Akram A. Hosseini, Claire V. Burley, Jennifer Dunne, Simin Mahinrad, Iman Dajani, Ralph N. Martins, Blossom C.M. Stephan, Ali Chaari, Hamid R. Sohrabi

Research outputs 2022 to 2026

Data on dementia epidemiology in the Middle East and North Africa (MENA) region is limited. This systematic review and meta-analysis examined dementia prevalence across MENA. Databases were searched up to October 2024. Analyses were stratified by country and sex. Pooled prevalence was estimated using a random-effects model with a 95% confidence interval (CI). Fifty-two studies on the selected countries met inclusion criteria, covering 87,219 individuals with dementia from a total population of 1,045,908. The pooled prevalence was 12.16% (95% CI: 9.61–14.96) for the region and the Israel had the highest prevalence (17.00%), followed by Iran (13.20%), Turkey (11.40%), Saudi Arabia …

When Does Alzheimer's Disease Start? Plasma Aβ42/40 Assays Show Steep Changes At Aβ-Pet Centiloid 15, Mean Age Of 66 Years, Rodrigo Cánovas, Timothy Cox, Vincent Doré, Pierrick Bourgeat, Jurgen Fripp, Azadeh Feizpour, Rosita Shishegar, Christopher J. Fowler, Simon M. Laws, Tenielle Porter, Stephanie Rainey-Smith, Leslie M. Shaw, Randall J. Bateman, Yan Li, Ovod Vitaliy, Michael W. Weiner, John C. Morris, Tammie L.S. Benzinger, Suzanne E. Schindler, Akinori Nakamura, Takeshi Iwatsubo, Takeshi Ikeuchi, Takashi Kato, Paul Maruff, Hamid R. Sohrabi, Christopher C. Rowe, Ralph Martins, Colin L. Masters, James Doecke

Research outputs 2022 to 2026

Objective: Sporadic late-onset Alzheimer's disease (AD) is characterized by a long pre-clinical phase where amyloid-beta (Aβ) and tau begin to accumulate in the brain. The primary objective was to determine the age at which AD starts by finding the average population age when both positron emission tomography (PET) Aβ (Aβ-PET) and plasma Aβ42/40 become abnormal. Methods: Two high performance immunoprecipitation-mass spectrometry (IP-MS) assays (WashU/C2N and Shimadzu) were tested on samples from 1,450 participants who were diagnosed as cognitively unimpaired (CU), mild cognitive impairment (MCI), or AD-dementia across 4 international cohorts. Natural history modeling and trajectory analyses of the combined Aβ-PET …

Unraveling The Significance Of Fecal Microrna Profile In Alzheimer’S Disease, Kavisha Katuwawala, Prashant Bharadwaj, Ian Martins, B. G.D.N.K. De Silva, Vincent Ho, Asiri Dissanayake, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Alzheimer’s disease (AD), a complex neurodegenerative disorder characterised by progressive cognitive decline, affects millions globally. With no current cure, treatment focuses on symptom management and slowing disease progression. Early identification is therefore crucial. Fecal microRNA (miRNA) analysis is emerging as a promising non-invasive diagnostic tool. Evidence suggests that miRNAs present in fecal samples may regulate gene expression linked to AD pathology, impacting cellular functions and disease progression. Dietary factors critically influence gut microbiota composition and diversity, affecting brain health via the gut brain axis. Macronutrients such as carbohydrates, proteins, and fats modulate miRNA expression and gut microbiota, influencing AD risk. …

Gut Microbial Composition And Short-Chain Fatty Acid Metabolism In Cognitively Unimpaired Adults Stratified By Amyloid-Β Status, D. M.Sithara Dissanayaka, Thilini N. Jayasinghe, Hamid R. Sohrabi, Stephanie R. Rainey-Smith, Kevin Taddei, Colin L. Masters, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Short-chain fatty acids (SCFAs) produced by gut microbial fermentation influence host metabolism and neuroinflammatory processes implicated in Alzheimer’s disease (AD). However, the relationship between fecal SCFAs, microbial taxa, and cerebral amyloid-β (Aβ) burden in cognitively unimpaired individuals remains unclear. Fecal SCFAs were quantified using GC-MS, and microbial species were profiled by shotgun metagenomics in 87 participants. Associations between SCFAs, demographics, APOE ε4 status, and Aβ burden were tested using nonparametric statistics and multivariable regression. Microbial–SCFA links were evaluated using Spearman correlations and multivariate ordinations, with mediation analysis exploring potential indirect pathways. Acetate was the predominant SCFA and demonstrated the most …

Pain In People With Dementia Is A Significant Contributor To Increased Professional Caregiver Burden: Results Of An Observation Study, Kreshnik Hoti, Ipsit Vahia, Paola Chivers, Jeffery Hughes

Research outputs 2022 to 2026

Aim: To investigate the association between the presence of neuropsychological symptoms, professional caregiver burden and pain intensity.

Methods: Eleven neuropsychiatric symptoms reportedly associated with caregiver burden which are included within the PainChek® pain assessment tool were identified: aggressiveness, inappropriate behavior, distressed, verbally offensive, confusion, restlessness, pacing and wandering, crying, screaming, altered sleep and resisting care. A caregiver burden score based on binary scoring of the presence of these indicators was calculated (summative score range from 0 to 11). Generalized estimating equations were used to evaluate the relationships between (1) pain score and sum of caregiver indicators present and (2) pain …

The Associations Between Sleep Environment Factors And Sleep Health In Individuals Living With Neurological Conditions, Mitchell Turner, Laws, Madeline Griffiths, Travis Cruickshank

Research outputs 2022 to 2026

Objectives: To explore associations between air temperature and light in the sleeping environment and sleep health in individuals with neurological conditions. Methods: The sleep health of 46 individuals with neurological conditions (mean age 51.37 ± 14.24 years; 20 males, 26 females) was measured using the Sleep Health Index (SHI). Air temperature and light data were captured across seven days using a light/temperature data logger positioned next to the participant’s bed. Data recorded during the participants’ sleeping periods (determined using a sleep diary) were analyzed. Linear regression models were used to assess the associations between air temperature and light and sleep …