| 1. |
- Bloniecki, Victor, et al.
(författare)
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Effects of Risperidone and Galantamine Treatment on Alzheimer's Disease Biomarker Levels in Cerebrospinal Fluid
- 2017
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 57:2, s. 387-393
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Treatment for neuropsychiatric symptoms (NPS) in dementia is insufficient. Antipsychotics and acetylcholinesterase inhibitors are used generating symptomatic improvements in behavior and cognition, but few studies have investigated their effect on Alzheimer's disease (AD) biomarkers in cerebrospinal fluid (CSF).OBJECTIVE: This is a secondary analysis based on an earlier clinical trial comparing the treatment effects on NPS. The aim of this study was to examine whether treatment with risperidone and galantamine affect levels of the biomarkers T-Tau, P-Tau, Aβ1-42, and Aβ42/40-ratio in CSF. The secondary aim was to test if baseline levels of these biomarkers are associated with the clinical course of NPS.METHODS: 83 patients (mean + SD 77.9.6±7.7 years) with dementia and NPS were randomized to galantamine (n = 44) or risperidone (n = 39) treatment. CSF samples were collected at baseline and after 12 weeks.RESULTS: Changes in levels of biomarkers between the two treatment groups did not differ significantly. Low baseline levels of Aβ1 - 42 was significantly associated with reduction of irritability at follow up. Low baseline levels of Aβ1-42, Aβ42/40, and P-Tau were significant correlates of reduction in appetite and eating disorders. CSF Aβ1-42 levels in patients treated with risperidone were significantly decreased at follow up, showing an 8% (40 pg/mL) reduction as compared with baseline (p = 0.03).CONCLUSIONS: Our results suggest that risperidone may affect the CSF profile of AD biomarkers indicating more amyloid pathology. Treatment with galantamine did not affect the CSF biomarkers in any direction. The AD CSF biomarkers displayed correlations with specific NPS suggesting potential research questions to be pursued.
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| 2. |
- Eriksdotter, Maria, et al.
(författare)
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Plasma Fatty Acid Profiles in Relation to Cognition and Gender in Alzheimer's Disease Patients During Oral Omega-3 Fatty Acid Supplementation : The OmegAD Study
- 2015
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 48:3, s. 805-812
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: ω3 fatty acids (ω3 FAs) may slow the rate of decline in cognitive performance in mild forms of cognitive impairment and Alzheimer's disease (AD). However, the relationship between changes of plasma ω3 FA levels and cognitive performance, as well as effects of gender, are poorly known.OBJECTIVE: To study the effect of 6-month administration of DHA-rich ω3 FA supplementation on plasma FA profiles in patients with mild to moderate AD in relation to cognitive performance and gender. This investigation is part of the OmegAD Study.METHODS: 174 AD patients (74 ± 9 years) were randomized to a daily intake of 2.3 g ω3 FA or placebo for 6 months; subsequently all received the ω3 FA preparation for the next 6 months. Baseline as well as changes in plasma levels of the main ω3 FAs in 165 patients, while receiving ω3 FA supplementation for 6 months, were analyzed for association to cognitive performance (assessed by ADAS-cog and MMSE scores) as well as to gender.RESULTS: Preservation of cognitive functioning, assessed by ADAS-cog or its sub-items (but not MMSE) scores, was significantly associated to increasing plasma ω3 FA levels over time. Thus, the higher ω3 FA plasma levels rose, the lower was the rate of cognitive deterioration. This effect was not related to gender; since although females displayed higher ω3 FA plasma levels than did males after 6 months of supplementation, this difference disappeared when adjusted for body weight.CONCLUSIONS: Since our study suggests dose-response relationships between plasma levels of ω3 FA and preservation of cognition, future ω3 FA trials in patients with mild AD should consider exploring graded (and body weight adjusted) doses of ω3 FA.
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| 3. |
- Falahati Asrami, Farshad
(författare)
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Neuroimaging biomarkers in Alzheimer’s disease
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Alzheimer’s disease (AD) is characterized by an accumulation of abnormal plaques and tangles in the brain, a process that is estimated to begin years before the appearance of clinical symptoms. Individuals with subjective memory decline (SMD) or mild cognitive impairment (MCI) run a higher risk of developing AD than cognitively normal (CN) people. The main aim of this thesis was to investigate the potential use of structural neuroimaging biomarkers in AD. A disease severity index (SI) based on multivariate data analysis of MRI-derived structural measures was generated. The SI was evaluated to discriminate AD patients from CN individuals as well as to monitor disease progression and predicting conversion to AD in SMD/MCI. In study I, the use of structural imaging and cerebrospinal fluid measures and factors that may affect the use of these methods in dementia work-up were investigated. The results showed that 94% of the patients had a brain scan performed. The results highlighted the role of MRI as an extended dementia investigation tool in younger patients with less severe cognitive impairment and a clinical presentation of less clear dementia symptoms. In study II, the performance of the SI in discriminating AD patients from CN subjects and in predicting conversion from MCI to AD was investigated. The role of age correction was also investigated and how it affected classification/prediction. Age correction did not only effectively eliminate the effect of age, it also highlighted age associations in other factors such as APOE genotype, global cognitive impairment and gender. In study III, the SI was longitudinally evaluated for monitoring disease progression in subjects with MCI. The results showed the potential of the SI to identify MCI subjects at risk of converting to AD and that disease progression could be monitored in an accurate way. Further, using the SI it could be observed that APOE genotype and amyloid pathology may independently modulate disease-related brain structural changes. In study IV, the SI was validated in a group of healthy individuals with SMD from a different cohort. Using the SI, a subgroup of SMD subjects who manifested structural brain patterns similar to AD was identified. These subjects had lower cognitive performance, higher amyloid burden and worse clinical progression compared to SMD individuals with structural brain patterns similar to CN. The SI as a neuroimaging biomarker was studied in the whole disease continuum from CN and SMD to MCI and AD. The SI showed strong potential to be used as a sensitive tool for predicting and monitoring disease progression in clinical trials or clinical practice. Nevertheless, in future the SI should be validated in clinical cohorts and the relationship between the SI and factors such as genotype and other AD biomarkers should be further investigated.
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| 4. |
- Faxen-Irving, Gerd, et al.
(författare)
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Does Fatty Acid Composition in Subcutaneous Adipose Tissue Differ between Patients with Alzheimer's Disease and Cohabiting Proxies?
- 2018
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 61:2, s. 515-519
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Tidskriftsartikel (refereegranskat)abstract
- Low tissue levels of the major marine ω3 fatty acids (FAs) DHA and EPA are found in Alzheimer's disease (AD). We investigated if healthy proxies to AD patients have higher levels of these ω3 FAs. We observed lower levels of EPA and DHA in subcutaneous adipose tissue biopsies from 64 AD patients compared with 16 cognitively healthy proxies. No significant difference was observed when pairwise comparisons were made between a subset of 16 AD patients and their co-habiting proxies. Larger studies are needed to replicate these findings and to determine if they could depend on FA intake or differences in metabolism.
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| 5. |
- Gustavsson, Jonatan, et al.
(författare)
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Contributions of the Catechol-O-Methyltransferase Val158Met Polymorphism to Changes in Brain Iron Across Adulthood and Their Relationships to Working Memory
- 2022
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Ageing is associated with excessive free brain iron, which may induce oxidative stress and neuroinflammation, likely causing cognitive deficits. Lack of dopamine may be a factor behind the increase of iron with advancing age, as it has an important role in cellular iron homoeostasis. We investigated the effect of COMT Val 158 Met (rs4680), a polymorphism crucial for dopamine degradation and proxy for endogenous dopamine, on iron accumulation and working memory in a longitudinal lifespan sample (n = 208, age 20-79 at baseline, mean follow-up time = 2.75 years) using structural equation modelling. Approximation of iron content was assessed using quantitative susceptibility mapping in striatum and dorsolateral prefrontal cortex (DLPFC). Iron accumulated in both striatum and DLPFC during the follow-up period. Greater iron accumulation in DLPFC was associated with more deleterious change in working memory. Older (age 50-79) Val homozygotes (with presumably lower endogenous dopamine) accumulated more iron than older Met carriers in both striatum and DLPFC, no such differences were observed among younger adults (age 20-49). In conclusion, individual differences in genetic predisposition related to low dopamine levels increase iron accumulation, which in turn may trigger deleterious change in working memory. Future studies are needed to better understand how dopamine may modulate iron accumulation across the human lifespan.
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| 6. |
- Gustavsson, Jonatan, et al.
(författare)
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The iron-dopamine D1 coupling modulates neural signatures of working memory across adult lifespan
- 2023
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Ingår i: NeuroImage. - : Elsevier. - 1053-8119 .- 1095-9572. ; 279
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Tidskriftsartikel (refereegranskat)abstract
- Brain iron overload and decreased integrity of the dopaminergic system have been independently reported as brain substrates of cognitive decline in aging. Dopamine (DA), and iron are co-localized in high concentrations in the striatum and prefrontal cortex (PFC), but follow opposing age-related trajectories across the lifespan. DA contributes to cellular iron homeostasis and the activation of D1-like DA receptors (D1DR) alleviates oxidative stress-induced inflammatory responses, suggesting a mutual interaction between these two fundamental components. Still, a direct in-vivo study testing the iron-D1DR relationship and their interactions on brain function and cognition across the lifespan is rare. Using PET and MRI data from the DyNAMiC study (n=180, age=20-79, %50 female), we showed that elevated iron content was related to lower D1DRs in DLPFC, but not in striatum, suggesting that dopamine-rich regions are less susceptible to elevated iron. Critically, older individuals with elevated iron and lower D1DR exhibited less frontoparietal activations during the most demanding task, which in turn was related to poorer working-memory performance. Together, our findings suggest that the combination of elevated iron load and reduced D1DR contribute to disturbed PFC-related circuits in older age, and thus may be targeted as two modifiable factors for future intervention.
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