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| 2. |
- Degerman Gunnarsson, Malin, 1969-
(författare)
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Biomarkers as Monitors of Drug Effect, Diagnostic Tools and Predictors of Deterioration Rate in Alzheimer’s Disease
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Decreased amyloid-ß42 (Aß42), increased total tau (t-tau) and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) reflect histopathological core changes in the most common dementia disorder, Alzheimer’s disease (AD). They discriminate AD from healthy controls and predict conversion to AD with a relatively high accuracy. Memantine, an uncompetitive NMDA-receptor antagonist, is indicated for symptomatic treatment of AD. The first aim of this thesis was to investigate effects of memantine on CSF concentrations of Aβ42, tau and p-tau. Secondly, the aim was to explore the relation between these CSF biomarkers and retention of the amyloid biomarker Pittsburgh compound B using positron emission tomography (PIB PET), regional glucose metabolism measured with 18Fluoro-2-deoxy-d-glucose (FDG) PET and neuropsychological test performance. The third aim was to investigate their possible utility as predictors of future rate of AD dementia deterioration. All patients in the studies were recruited from the Memory Clinic, Uppsala University Hospital. In study I CSF p-tau concentrations in 11 AD patients were reduced after twelve months treatment with memantine, indicating that this compound may affect a key pathological process in AD. Results from study II showed that the concentrations of CSF Aß42 are lower in PIB+ patients than in PIB- patients, and that the PIB retention was stable during 12 months. In study III 10 patients with the diagnoses AD (6 PIB+/4 PIB-) and 8 subjects (1 PIB+/7 PIB-) with frontotemporal dementia were included. PIB+ patients had lower psychomotor speed measured by performance on the Trail Making Test A and impaired visual episodic memory compared to the PIB- patients. The initial clinical diagnoses were changed in 33% of the patients (6/18) during follow-up. Study IV is the first-ever report of an association between high CSF tau and dying in severe dementia. These 196 AD patients were followed up to nine years after baseline lumbar puncture. Moreover, CSF t-tau concentrations above median was associated with an increased risk of rapid cognitive decline (OR 3.31 (95% CI 1.53-7.16), independently of baseline functional stage. Thus, a clear association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease was shown.
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| 3. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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High Tau Levels in Cerebrospinal Fluid Predict Rapid Decline and Increased Dementia Mortality in Alzheimer's Disease
- 2014
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 37:3-4, s. 196-206
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cerebrospinal fluid (CSF) amyloid beta(42) (A beta(42)), total tau (t-tau) and phosphorylated tau (p-tau) are useful as predictors of conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia. However, results are contradictory as to whether these biomarkers reflect the future rate of clinical decline. Methods: This is a retrospective study on 196 patients with AD [mild/moderate AD (n = 72) or AD-MCI (n = 124) at baseline] with a follow-up period of 2-9 years' duration (median 6 years). Lumbar punctures were performed at baseline as a part of the diagnostic procedure. Results: We found an increased risk of rapid cognitive decline defined as a drop in the Mini-Mental State Examination score of = 4 points/year in patients with CSF t-tau concentrations above the median (OR 3.31, 95% CI 1.53-7.16) and CSF p-tau above the median (OR 2.53, 95% CI 1.21-5.26). Patients with CSF t-tau in the highest quartile had a higher risk of dying in severe dementia (HR 4.67, 95% CI 1.16-18.82). Conclusions: In this large AD cohort, we found an association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease, measured as a rapid cognitive decline and a higher risk of dying in severe dementia.
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| 4. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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Re-Evaluation of Clinical Dementia Diagnoses with Pittsburgh Compound B Positron Emission Tomography
- 2013
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Ingår i: Dementia and Geriatric Cognitive Disorders Extra. - Basel : S. Karger. - 1664-5464. ; 3:1, s. 472-481
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [18F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET). Methods: Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting. Results: The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up. Conclusions: The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.
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- Faxén-Irving, Gerd, et al.
(författare)
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Effects on transthyretin in plasma and cerebrospinal fluid by DHA-rich n - 3 fatty acid supplementation in patients with Alzheimer's disease : the OmegAD study
- 2013
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 36:1, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Transthyretin (TTR) binds amyloid-β (Aβ) and may reduce brain Aβ, a pathological feature in Alzheimer's disease (AD). N - 3 fatty acids (FA), docosahexaenoic (DHA), and eicosapentaenoic acid (EPA) may increase TTR transcription in rat hippocampus. We studied effects of n - 3 FA supplementation on TTR-levels in patients with AD. Outpatients were randomized to receive 1.7 g DHA and 0.6 g EPA (n - 3/n - 3 group) or placebo (placebo/n - 3 group) during 6 months. After 6 months, all patients received n - 3 FA for another 6 months. TTR and FA were measured in plasma in all subjects, whereas TTR in cerebrospinal fluid (CSF) was measured in a subgroup. The study was completed by 89 patients in the n - 3/n - 3 group (75 y, 57% w) and 85 in the placebo/n - 3 group (75 y, 46% w). Baseline plasma-TTR was within normal range in both groups. After 6 months, plasma-TTR decreased in the placebo/n - 3 group (p < 0.001 within and p < 0.015 between the groups). No changes were observed in CSF TTR. From 6 to 12 months when both groups were supplemented, plasma-TTR increased significantly in both groups. Repeated measures ANOVA indicated an increase in TTR over time (p = 0.04) in those receiving n - 3 FA for 12 months. By linear regression analyses, n - 3 FA treatment was independently associated with increased plasma-TTR at 6 months (β = -0.172, p = 0.028). Thus, n - 3 FA treatment appeared to increase plasma-TTR in patients with AD. Since TTR may influence Aβ deposition in the brain, the results warrant further exploration.
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- Freund-Levi, Yvonne, 1956-, et al.
(författare)
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Effects of supplementation with omega-3 fatty acids on oxidative stress and inflammation in patients with Alzheimer's disease : the OmegAD study
- 2014
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 42:3, s. 823-831
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oxidative stress and inflammation are two key mechanisms suggested to be involved in the pathogenesis of Alzheimer's disease (AD). Omega-3 fatty acids (ω-3 FAs) found in fish and fish oil have several biological properties that may be beneficial in AD. However, they may also auto-oxidize and induce in vivo lipid peroxidation.OBJECTIVE: The objective of this study was to evaluate systemic oxidative stress and inflammatory biomarkers following oral supplementation of dietary ω-3 FA.METHODS: Forty patients with moderate AD were randomized to receive 1.7 g DHA (22:6) and 0.6 g EPA (20:5) or placebo for 6 months. Urinary samples were collected before and after supplementation. The levels of the major F2-isoprostane, 8-iso-PGF2α, a consistent in vivo biomarker of oxidative stress, and 15-keto-dihydro-PGF2α, a major metabolite of PGF2α and biomarker of inflammatory response, were measured.RESULTS: F2-isoprostane in urine increased in the placebo group after 6 months, but there was no clear difference in treatment effect between supplemented and non-supplemented patients on the urinary levels of F2-isoprostanes and 15-keto-dihydro-PGF2α. At baseline, the levels of 15-keto-dihydro-PGF2α showed negative correlative relationships to ω-3 FAs, and a positive correlation to linoleic acid. 8-iso-PGF2α correlated negatively to the ω-6 FA arachidonic acid.CONCLUSION: The findings indicate that supplementation of ω-3 FAs to patients with AD for 6 months does not have a clear effect on free radical-mediated formation of F2-isoprostane or cyclooxygenase-mediated formation of prostaglandin F2α. The correlative relationships to FAs indicate a potential role of FAs in immunoregulation.
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| 7. |
- Freund-Levi, Yvonne, 1956-, et al.
(författare)
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Transfer of omega-3 fatty acids across the blood-brain barrier after dietary supplementation with a docosahexaenoic acid-rich omega-3 fatty acid preparation in patients with Alzheimer's disease : the OmegAD study
- 2014
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Ingår i: Journal of Internal Medicine. - : Blackwell Publishing. - 0954-6820 .- 1365-2796. ; 275:4, s. 428-436
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Little is known about the transfer of essential fatty acids (FAs) across the human blood-brain barrier (BBB) in adulthood. In this study, we investigated whether oral supplementation with omega-3 (n-3) FAs would change the FA profile of the cerebrospinal fluid (CSF).METHODS: A total of 33 patients (18 receiving the n-3 FA supplement and 15 receiving placebo) were included in the study. These patients were participants in the double-blind, placebo-controlled randomized OmegAD study in which 204 patients with mild Alzheimer's disease (AD) received 2.3 g n-3 FA [high in docosahexaenoic acid (DHA)] or placebo daily for 6 months. CSF FA levels were related to changes in plasma FA and to CSF biomarkers of AD and inflammation.RESULTS: At 6 months, the n-3 FA supplement group displayed significant increases in CSF (and plasma) eicosapentaenoic acid (EPA), DHA and total n-3 FA levels (P < 0.01), whereas no changes were observed in the placebo group. Changes in CSF and plasma levels of EPA and n-3 docosapentaenoic acid were strongly correlated, in contrast to those of DHA. Changes in DHA levels in CSF were inversely correlated with CSF levels of total and phosphorylated tau, and directly correlated with soluble interleukin-1 receptor type II. Thus, the more DHA increased in CSF, the greater the change in CSF AD/inflammatory biomarkers.CONCLUSIONS: Oral supplementation with n-3 FAs conferred changes in the n-3 FA profile in CSF, suggesting transfer of these FAs across the BBB in adults.
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| 8. |
- Hjorth, Erik, et al.
(författare)
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Omega-3 fatty acids enhance phagocytosis of Alzheimer's disease-related amyloid-β42 by human microglia and decrease inflammatory markers
- 2013
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 35:4, s. 697-713
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Tidskriftsartikel (refereegranskat)abstract
- The use of supplements with omega-3 (ω3) fatty acids (FAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) is widespread due to proposed beneficial effects on the nervous and cardiovascular systems. Many effects of ω3 FAs are believed to be caused by down-regulation and resolution of inflammation. Alzheimer's disease (AD) is associated with inflammation mediated by microglia and astrocytes, and ω3 FAs have been proposed as potential treatments for AD. The focus of the present study is on the effects of DHA and EPA on microglial phagocytosis of the AD pathogen amyloid-β (Aβ), on secreted and cellular markers of immune activity, and on production of brain-derived neurotrophic factor (BDNF). Human CHME3 microglial cells were exposed to DHA or EPA, with or without the presence of Aβ42. Phagocytosis of Aβ42 was analyzed by flow cytometry in conjunction with immunocytochemistry using antibodies to cellular proteins. Secreted proteins were analyzed by ELISA. Both DHA and EPA were found to stimulate microglial phagocytosis of Aβ42. Phagocytosis of Aβ42 was performed by microglia with a predominance of M2 markers. EPA increased the levels of BDNF in the culture medium. The levels of TNF-α were decreased by DHA. Both DHA and EPA decreased the pro-inflammatory M1 markers CD40 and CD86, and DHA had a stimulatory effect on the anti-inflammatory M2 marker CD206. DHA and EPA can be beneficial in AD by enhancing removal of Aβ42, increasing neurotrophin production, decreasing pro-inflammatory cytokine production, and by inducing a shift in phenotype away from pro-inflammatory M1 activation.
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| 9. |
- Höglund, Kina, 1976, et al.
(författare)
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Longitudinal Stability Evaluation of Biomarkers and Their Correlation in Cerebrospinal Fluid and Plasma from Patients with Alzheimer's Disease
- 2012
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 32:4, s. 939-947
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Tidskriftsartikel (refereegranskat)abstract
- There is an increasing demand for biomarkers in clinical treatment trials to demonstrate target engagement and to support disease modification claims. To be able to detect treatment related effects, a prerequisite is that the levels of the biomarker are stable over time or that the change over time is known. In the present study, the stability of alpha- and beta-cleaved soluble amyloid-beta protein precursor (sA beta PP alpha and sA beta PP beta), A beta(1-40) together with the phosphorylated form of neurofilament heavy/medium (pNfH/M) in cerebrospinal fluid (CSF) was analyzed in a cohort of 51 patients with Alzheimer's disease. In addition, the stability of A beta(1-40), beta(1-42), and sA beta PP beta in plasma was explored. Plasma and CSF was sampled at baseline and after 6-months follow up, and all patients were on stable treatment with acetylcholinesterase inhibitors. During this 6-month longitudinal follow-up, we saw a small, but consistent and statistically significant increase in CSF levels of sA beta PP beta (103% of baseline levels) and a statistically significant decrease in the CSF levels of pNfH/M (91% of baseline levels). The mean level of the CSF biomarkers were very stable between baseline and endpoint, with within-patients coefficients of variation (CVs) of 5.84-17.3%, while the variability was larger for the plasma biomarkers, with CVs of 14.1-42.3%. This stability suggests that these biomarkers may have the potential to detect and monitor biochemical changes induced by disease-modifying drugs.
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| 10. |
- Kalimo, H., et al.
(författare)
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Details of neuropathology in Arctic Alzheimer's disease
- 2010
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Ingår i: Abstracts of the XVIIth International Congress of Neuropathology (ICN 2010), Salzburg, Austria, 11-15 September 2010. - : Wiley. ; , s. 22-23
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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