| 1. |
- Vandenberghe, Rik, et al.
(författare)
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F-18-Flutemetamol Amyloid Imaging in Alzheimer Disease and Mild Cognitive Impairment A Phase 2 Trial
- 2010
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 68:3, s. 319-329
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The most widely studied positron emission tomography ligand for in vivo P-amyloid imaging is C-11-Pittsburgh compound B (C-11-PIB). Its availability, however, is limited by the need for an on-site cyclotron. Validation of the F-18-labeled PIB derivative F-18-flutemetamol could significantly enhance access to this novel technology. Methods: Twenty-seven patients with early-stage clinically probable Alzheimer disease (AD), 20 with amnestic mild cognitive impairment (MCI), and 15 cognitively intact healthy volunteers (HVs) above and 10 HVs below 55 years of age participated. The primary endpoint was the efficacy of blinded visual assessments of F-18-flutemetamol scans in assigning subjects to a raised versus normal uptake category, with clinical diagnosis as the standard of truth (SOT). As secondary objectives, we determined the correlation between the regional standardized uptake value ratios (SUVRs) for F-18-flutemetamol and its parent molecule C-11-PIB in 20 of the AD subjects and 20 of the MCI patients. We also determined test-retest variability of F-18-flutemetamol SUVRs in 5 of the AD subjects. Results: Blinded visual assessments of F-18-flutemetamol scans assigned 25 of 27 scans from AD subjects and 1 of 15 scans from the elderly HVs to the raised category, corresponding to a sensitivity of 93.1% and a specificity of 93.3% against the SOT. Correlation coefficients between cortical F-18-flutemetamol SUVRs and C-11-PIB SUVRs ranged from 0.89 to 0.92. Test-retest variabilities of regional SUVRs were 1 to 4%. Interpretation: F-18-Flutemetamol performs similarly to the C-11-PIB parent molecule within the same subjects and provides high test-retest replicability and potentially much wider accessibility for clinical and research use. ANN NEUROL 2010;68:319-329
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| 2. |
- Abramsson, Alexandra, 1973, et al.
(författare)
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No Association of LOXL1 Gene Polymorphisms with Alzheimer's Disease
- 2011
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Ingår i: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 13:2, s. 160-166
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Tidskriftsartikel (refereegranskat)abstract
- Aggregation of amyloid-beta is one of the major characteristics in brains of patients with Alzheimer's disease (AD). Although several mechanisms behind the formation of such aggregates have been suggested the regulatory factors are still unknown. The present study aimed at investigating the association of lysyl oxidase-like 1 (LOXL1) polymorphisms with AD diagnosis and cerebrospinal fluid biomarkers (CSF) for the disease. Proteins of the lysyl oxidase (LOX) family are involved in cross-linking extracellular matrix proteins to insoluble fibers and have been associated with neurodegenerative diseases including AD. Genetic polymorphisms in LOXL1 (rs1048661, rs3825942, and rs2165241) have been linked to exfoliation syndrome and exfoliation glaucoma, conditions that have shown association with AD. The polymorphisms were genotyped by Taqman allelic discrimination in a study sample including AD patients (n = 318) and controls (n = 575). In a subgroup of the population, the polymorphisms were analyzed in relation to APOE epsilon 4 genotype and to CSF (T-tau, P-tau, and A beta(1-42)). No evidence for associations of these polymorphisms with risk for AD or any of the studied CSF biomarkers measured was found. These results do not support LOXL1 as being a major risk gene for AD.
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| 3. |
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| 4. |
- Andersson, Maria A, et al.
(författare)
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The cognitive profile and CSF biomarkers in dementia with Lewy bodies and Parkinson's disease dementia.
- 2011
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Ingår i: International journal of geriatric psychiatry. - : Wiley. - 1099-1166 .- 0885-6230. ; 26:1, s. 100-5
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Tidskriftsartikel (refereegranskat)abstract
- Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) may be viewed as different points on a continuum reflecting the regional burden and distribution of pathology. An important clinical consideration is overlapping Alzheimer's disease (AD) pathology, since it has been reported that associated AD pathology in DLB shortens survival and leads to a more rapid cognitive decline. We aimed to investigate cerebrospinal fluid (CSF) biomarkers and the associated cognitive profile in DLB and PDD.
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| 5. |
- Ballard, Clive, et al.
(författare)
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alpha-synuclein antibodies recognize a protein present at lower levels in the CSF of patients with dementia with Lewy bodies
- 2010
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Ingår i: International Psychogeriatrics. - 1741-203X. ; 22:2, s. 321-327
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dementia with Lewy bodies (DLB) accounts for 15-20%, of the millions of people worldwide with dementia. Accurate diagnosis is essential to avoid harm and optimize clinical management. There is therefore an urgent need to identify reliable biomarkers. Methods: Mass spectrometry was used to determine the specificity of antibody alpha-synuclein (211) for alpha-synuclein. Using gel electrophoresis we measured protein levels detected by alpha-synuclein specific antibodies in the cerebrospinal fluid (CSF) of DLB patients and compared them to age matched controls. Results: A 24 kDa band was detected using alpha-synuclein specific antibodies which was significantly reduced in the CSF of DLB patients compared to age matched controls (p < 0.05). Further analysis confirmed that even DLB patients with mild dementia showed significant reductions in this protein in comparison to controls. Conclusions: The current study emphasizes the necessity for further studies of CSF alpha-synuclein as a biomarker of DLB and extends our previous knowledge by establishing a potential relationship between alpha-synuclein and the severity of cognitive impairment. The identification of this 24 kDa protein is the next important step in these studies.
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| 6. |
- Bengtsson Lindberg, Marie, et al.
(författare)
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Evaluation of Systolic and Diastolic Hypotension in Dementia with Lewy Bodies and Alzheimer’s Disease.
- 2013
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Ingår i: Healthy Aging & Clinical Care in the Elderly. - 1179-0601. ; 5, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Orthostatic hypotension (OH) can be seen in as many as 30% to 50% of the elderly population as well as in dementia. OH is part of the autonomic dysfunction in dementia with Lewy bodies (DLB) and prevalent in the majority of these patients. It is also suggested to be a negative prognostic factor for survival in DLB. A detailed interpretation of the 10-minute orthostatic blood pressure measurement has shown prolonged orthostasis in DLB compared with other dementias. The type of OH (systolic and diastolic) has not been separately investigated in different dementias. OBJECTIVES: The aims of this study were to analyze the type of orthostatic hypotension, systolic and/or diastolic, in different dementia groups compared with normal controls. PATIENTS AND METHODS: One-hundred fifty-six individuals, 52 with DLB, 50 with Alzheimer’s disease (AD), 54 AD with vascular components (ADvasc), and 62 normal controls, were included. As part of each patient’s routine clinical dementia investigation, systolic and diastolic blood pressure measurements were examined in the supine position, immediately after standing up, and after 1, 3, 5, and 10 minutes of standing. OH was defined as a blood pressure drop of 20 mmHg systolic or 10 mmHg diastolic, and the type of OH—systolic, diastolic or both—was defined. RESULTS: Orthostatic hypotension was severely underdiagnosed before the dementia investigation with only 2% to 4% in the dementia groups, while we found that 69% of DLB, 50% of ADvasc, 38% of AD, and 13% of normal controls had OH. A combination of systolic and diastolic OH was the most common type of OH both in the DLB (67%) and ADvasc (48%) groups, while systolic OH was the most common type in AD (63 %) as well as in normal controls (63%). Mini Mental State Examination scores differed significantly (P < 0.001) between the group with no OH (25.2 ± 4.8) and the group with combined systolic and diastolic OH (22.0 ± 4.8). CONCLUSION: Patients with DLB showed a greater proportion of combined systolic and diastolic hypotension. This might suggest a more complex OH than in patients with AD or elderly controls, possibly exacerbating the clinical picture in DLB. Further investigations of the relevance of these findings and the relation to clinical symptoms are needed.
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| 7. |
- Bjerke, Maria, 1977, et al.
(författare)
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Confounding factors influencing amyloid Beta concentration in cerebrospinal fluid.
- 2010
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Ingår i: International journal of Alzheimer's disease. - : Hindawi Limited. - 2090-0252. ; 2010
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Tidskriftsartikel (refereegranskat)abstract
- Background. Patients afflicted with Alzheimer's disease (AD) exhibit a decrease in the cerebrospinal fluid (CSF) concentration of the 42 amino acid form of beta-amyloid (Abeta(42)). However, a high discrepancy between different centers in measured Abeta(42) levels reduces the utility of this biomarker as a diagnostic tool and in monitoring the effect of disease modifying drugs. Preanalytical and analytical confounding factors were examined with respect to their effect on the measured Abeta(42) level. Methods. Aliquots of CSF samples were either treated differently prior to Abeta(42) measurement or analyzed using different commercially available xMAP or ELISA assays. Results. Confounding factors affecting CSF Abeta(42) levels were storage in different types of test tubes, dilution with detergent-containing buffer, plasma contamination, heat treatment, and the origin of the immunoassays used for quantification. Conclusion. In order to conduct multicenter studies, a standardized protocol to minimize preanalytical and analytical confounding factors is warranted.
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| 8. |
- Björkqvist, Maria, et al.
(författare)
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Evaluation of a previously suggested plasma biomarker panel to identify Alzheimer's disease.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need for biomarkers in plasma to identify Alzheimer's disease (AD). It has previously been shown that a signature of 18 plasma proteins can identify AD during pre-dementia and dementia stages (Ray et al, Nature Medicine, 2007). We quantified the same 18 proteins in plasma from 174 controls, 142 patients with AD, and 88 patients with other dementias. Only three of these proteins (EGF, PDG-BB and MIP-1δ) differed significantly in plasma between controls and AD. The 18 proteins could classify patients with AD from controls with low diagnostic precision (area under the ROC curve was 63%). Moreover, they could not distinguish AD from other dementias. In conclusion, independent validation of results is important in explorative biomarker studies.
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| 9. |
- Brinkmalm, Gunnar, et al.
(författare)
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Soluble amyloid precursor protein alpha and beta in CSF in Alzheimer's disease
- 2013
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Ingår i: Brain Research. - : Elsevier BV. - 1872-6240 .- 0006-8993. ; 1513, s. 117-126
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cerebral accumulation of amyloid beta (A beta) is a pathological hallmark of Alzheimer's disease (AD). Proteolytic processing of amyloid precursor protein (APP) by alpha- or beta-secretase results in two soluble metabolites, sAPP alpha and sAPP beta, respectively. However, previous data have shown that both alpha- and beta-secretase have multiple cleavage sites. The aim of this study was to characterize the C-termini of sAPP alpha and sAPP beta in cerebrospinal fluid (CSF) by mass spectrometry (MS) and to evaluate whether different combinations of these fragments better separate between AD patients and controls by comparing two different sAPP immunoassays. Methods: Using immunoprecipitation and high resolution MS, the APP species present in CSF were investigated. CSF levels of sAPP alpha and sAPP beta from patients with AD (n=43) and from non-demented controls (n=44) were measured using AlphaLISA and MSD immunoassays that employ different antibodies for C-terminal recognition of sAPP alpha. Results: Four different C-terminal forms of sAPP were identified, sAPP beta-M671, sAPP beta-Y681, sAPP alpha-Q686, and 5APP alpha-K687 (APP770 numbering). Neither immunoassay for the sAPP species could separate the two patient groups. The correlation (R-2) between the two immunoassays was 0.41 for sAPP alpha and 0.45 for sAPP beta. Conclusion: Using high resolution MS, we show here for the first time that sAPP alpha in CSF ends at Q686 and K687. The findings also support the conclusion from several previous studies that sAPP alpha and sAPP beta levels are unaltered in AD. (C) 2013 Elsevier B.V. All rights reserved.
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| 10. |
- Brinkmalm, Gunnar, et al.
(författare)
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Soluble amyloid precursor protein α and β in CSF in Alzheimer's disease.
- 2013
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Ingår i: Brain research. - : Elsevier BV. - 1872-6240 .- 0006-8993. ; 1513, s. 117-26
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral accumulation of amyloid β (Aβ) is a pathological hallmark of Alzheimer's disease (AD). Proteolytic processing of amyloid precursor protein (APP) by α- or β-secretase results in two soluble metabolites, sAPPα and sAPPβ, respectively. However, previous data have shown that both α- and β-secretase have multiple cleavage sites. The aim of this study was to characterize the C-termini of sAPPα and sAPPβ in cerebrospinal fluid (CSF) by mass spectrometry (MS) and to evaluate whether different combinations of these fragments better separate between AD patients and controls by comparing two different sAPP immunoassays. Methods: Using immunoprecipitation and high resolution MS, the APP species present in CSF were investigated. CSF levels of sAPPα and sAPPβ from patients with AD (n=43) and from non-demented controls (n=44) were measured using AlphaLISA and MSD immunoassays that employ different antibodies for C-terminal recognition of sAPPα. Results: Four different C-terminal forms of sAPP were identified, sAPPβ-M671, sAPPβ-Y681, sAPPα-Q686, and sAPPα-K687 (APP770 numbering). Neither immunoassay for the sAPP species could separate the two patient groups. The correlation (R(2)) between the two immunoassays was 0.41 for sAPPα and 0.45 for sAPPβ. Conclusion: Using high resolution MS, we show here for the first time that sAPPα in CSF ends at Q686 and K687. The findings also support the conclusion from several previous studies that sAPPα and sAPPβ levels are unaltered in AD.
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