| 1. |
- Brinkmalm, Gunnar, et al.
(författare)
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An online nano-LC-ESI-FTICR-MS method for comprehensive characterization of endogenous fragments from amyloid β and amyloid precursor protein in human and cat cerebrospinal fluid.
- 2012
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Ingår i: Journal of mass spectrometry : JMS. - : Wiley. - 1096-9888 .- 1076-5174. ; 47:5, s. 591-603
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) is the precursor protein to amyloid β (Aβ), the main constituent of senile plaques in Alzheimer's disease (AD). Endogenous Aβ peptides reflect the APP processing, and greater knowledge of different APP degradation pathways is important to understand the mechanism underlying AD pathology. When one analyzes longer Aβ peptides by low-energy collision-induced dissociation tandem mass spectrometry (MS/MS), mainly long b-fragments are observed, limiting the possibility to determine variations such as amino acid variants or post-translational modifications (PTMs) within the N-terminal half of the peptide. However, by using electron capture dissociation (ECD), we obtained a more comprehensive sequence coverage for several APP/Aβ peptide species, thus enabling a deeper characterization of possible variants and PTMs. Abnormal APP/Aβ processing has also been described in the lysosomal storage disease Niemann-Pick type C and the major large animal used for studying this disease is cat. By ECD MS/MS, a substitution of Asp7 → Glu in cat Aβ was identified. Further, sialylated core 1 like O-glycans at Tyr10, recently discovered in human Aβ (a previously unknown glycosylation type), were identified also in cat cerebrospinal fluid (CSF). It is therefore likely that this unusual type of glycosylation is common for (at least) species belonging to the magnorder Boreoeutheria. We here describe a detailed characterization of endogenous APP/Aβ peptide species in CSF by using an online top-down MS-based method.
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| 2. |
- Constantinescu, Radu, 1966, et al.
(författare)
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Proteomic profiling of cerebrospinal fluid in parkinsonian disorders.
- 2010
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Ingår i: Parkinsonism & related disorders. - : Elsevier BV. - 1873-5126 .- 1353-8020. ; :16, s. 545-49
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) and atypical parkinsonian disorders (APD), including multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD), are a group of neurodegenerative diseases sharing many similar signs and symptoms but distinguished by their particular clinical features, treatment response, prognosis and mortality. The differential diagnosis may be challenging, especially in early disease stages. Considering the importance of an accurate diagnosis both for clinical management and for research, new diagnostic tools are needed. In this study, we investigated 56 PD, 42 MSA, 39 PSP, 9 CBD patients, and 24 healthy controls. After screening the cerebrospinal fluid (CSF) proteome using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS), we identified 4 proteins (ubiquitin [mass-to-charge ratio (m/z) 8590], beta2-microglobulin [m/z 11730], and 2 secretogranin 1 [chromogranin B] fragments [m/z 7260 and m/z 6250]) that differentiated healthy controls and PD patients from patients with APD. However, they could not differentiate PD patients from controls. As none of these changes were APD subgroup-specific, they most likely reflect the intensity and/or extent of the neurodegenerative process in general.
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| 3. |
- Hesse, Camilla, et al.
(författare)
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The N-terminal domain of α-dystroglycan is released as a 38kDa protein and is increased in cerebrospinal fluid in patients with Lyme neuroborreliosis.
- 2011
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Ingår i: Biochemical and biophysical research communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 412:3
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Tidskriftsartikel (refereegranskat)abstract
- α-Dystroglycan is an extracellular adhesion protein that is known to interact with different ligands. The interaction is thought to stabilize the integrity of the plasma membrane. The N-terminal part of α-dystroglycan may be proteolytically processed to generate a small 38kDa protein (α-DG-N). The physiological significance of α-DG-N is unclear but has been suggested to be involved in nerve regeneration and myelination and to function as a potential biomarker for neurodegenerative and neuromuscular diseases. In this report we show that α-DG-N is released into different body fluids, such as lachrimal fluid, cerebrospinal fluid (CSF), urine and plasma. To investigate the significance of α-DG-N in CSF we examined the levels of α-DG-N and known neurodegenerative markers in CSF from patients diagnosed with Lyme neuroborreliosis (LNB) and healthy controls. In untreated acute phase LNB patients, 67% showed a significant increase of CSF α-DG-N compared to healthy controls. After treatment with antibiotics the CSF α-DG-N levels were normalized in the LNB patients.
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| 4. |
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| 5. |
- Mattsson, Niklas, 1979, et al.
(författare)
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Neuroinflammation in Lyme neuroborreliosis affects amyloid metabolism.
- 2010
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Ingår i: BMC Neurology. - : Springer Science and Business Media LLC. - 1471-2377. ; 10:51
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The metabolism of amyloid precursor protein (APP) and beta-amyloid (Abeta) is widely studied in Alzheimer's disease, where Abeta deposition and plaque development are essential components of the pathogenesis. However, the physiological role of amyloid in the adult nervous system remains largely unknown. We have previously found altered cerebral amyloid metabolism in other neuroinflammatory conditions. To further elucidate this, we investigated amyloid metabolism in patients with Lyme neuroborreliosis (LNB). METHODS: The first part of the study was a cross-sectional cohort study in 61 patients with acute facial palsy (19 with LNB and 42 with idiopathic facial paresis, Bell's palsy) and 22 healthy controls. CSF was analysed for the beta-amyloid peptides Abeta38, Abeta40 and Abeta42, and the amyloid precursor protein (APP) isoforms alpha-sAPP and beta-sAPP. CSF total-tau (T-tau), phosphorylated tau (P-tau) and neurofilament protein (NFL) were measured to monitor neural cell damage. The second part of the study was a prospective cohort-study in 26 LNB patients undergoing consecutive lumbar punctures before and after antibiotic treatment to study time-dependent dynamics of the biomarkers. RESULTS: In the cross-sectional study, LNB patients had lower levels of CSF alpha-sAPP, beta-sAPP and P-tau, and higher levels of CSF NFL than healthy controls and patients with Bell's palsy. In the prospective study, LNB patients had low levels of CSF alpha-sAPP, beta-sAPP and P-tau at baseline, which all increased towards normal at follow-up. CONCLUSIONS: Amyloid metabolism is altered in LNB. CSF levels of alpha-sAPP, beta-sAPP and P-tau are decreased in acute infection and increase after treatment. In combination with earlier findings in multiple sclerosis, cerebral SLE and HIV with cerebral engagement, this points to an influence of neuroinflammation on amyloid metabolism.
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| 6. |
- Mattsson, Niklas, 1979, et al.
(författare)
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Reduced cerebrospinal fluid BACE1 activity in multiple sclerosis.
- 2009
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Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1352-4585 .- 1477-0970. ; 15:4, s. 448-54
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cell and animal experiments have shown that beta-site APP-cleaving enzyme 1 (BACE1) may be involved in myelination. OBJECTIVE: Here, we assess the association of cerebrospinal fluid (CSF) BACE1 activity with multiple sclerosis (MS). METHODS: BACE1 activity and levels of secreted amyloid precursor protein (APP) and amyloid-beta (Abeta) isoforms were analyzed in CSF from 100 patients with MS and 114 neurologically healthy controls. Patients with systemic lupus erythematosus (SLE), 26 with and 41 without cerebral engagement, were also included to enable comparisons with regards to another autoimmune disease. A subset of patients with MS and controls underwent a second lumbar puncture after 10 years. RESULTS: MS patients had lower CSF BACE1 activity than controls (P = 0.03) and patients with cerebral SLE (P < 0.001). Patients with cerebral SLE had higher BACE1 activity than any other group (P < 0.05 for all comparisons). BACE1 activity correlated with the different amyloid markers in all study groups. BACE1 activity decreased over 10 years in the MS group (P = 0.039) and correlated weakly with clinical disease severity scores in an inverse manner. CONCLUSIONS: These results suggest an involvement of BACE1 in the MS disease process.
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| 7. |
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| 8. |
- Augutis, Kristin, et al.
(författare)
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Cerebrospinal fluid biomarkers of β-amyloid metabolism in multiple sclerosis.
- 2013
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Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 19:5, s. 543-52
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) and amyloid β (Aβ) peptides are intensely studied in neuroscience and their cerebrospinal fluid (CSF) measurements may be used to track the metabolic pathways of APP in vivo. Reduced CSF levels of Aβ and soluble APP (sAPP) fragments are reported in inflammatory diseases, including multiple sclerosis (MS); but in MS, the precise pathway of APP metabolism and whether it can be affected by disease-modifying treatments remains unclear.
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| 9. |
- Axelsson, Markus, 1975, et al.
(författare)
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The influence of disease duration, clinical course, and immunosuppressive therapy on the synthesis of intrathecal oligoclonal IgG bands in multiple sclerosis.
- 2013
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Ingår i: Journal of Neuroimmunology. - : Elsevier BV. - 0165-5728. ; 264:1-2, s. 100-5
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the impact of disease duration, clinical course and immunosuppressive therapy on intrathecal IgG synthesis in multiple sclerosis (MS). Cerebrospinal fluid (CSF) was obtained twice, 8-10years apart, from 20 MS patients and 26 healthy controls, and from 22 MS patients before and after two years of mitoxantrone treatment. The oligoclonal IgG band patterns changed in 15 patients at long-term follow-up, but were only influenced in 4 patients by mitoxantrone therapy. The CSF B-cell-regulating chemokine CXCL13 correlated with intrathecal IgG production suggesting a B-cell-dependence of intrathecal IgG synthesis in MS.
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| 10. |
- Bartlett, Jonathan W, et al.
(författare)
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Determining cut-points for Alzheimer's disease biomarkers: statistical issues, methods and challenges.
- 2012
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Ingår i: Biomarkers in medicine. - : Future Medicine Ltd. - 1752-0371 .- 1752-0363. ; 6:4, s. 391-400
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Tidskriftsartikel (refereegranskat)abstract
- New proposed criteria for the clinical diagnosis of Alzheimer's disease increasingly incorporate biomarkers, most of which are normally measured on a continuous scale. Operationalizing such criteria thus requires continuous biomarkers to be dichotomized, which in turns requires the selection of a cut-point at which to dichotomize. In this article, we review the statistical principles underlying the choice of cut-points, describe some of the most commonly adopted statistical approaches used to estimate cut-points, highlight potential pitfalls in some of the approaches and characterize in what sense the estimated cut-point from each approach is optimal. We also emphasize that how a cut-point is selected must be made in reference to how the resulting dichotomized biomarker is to be used, and in particular what actions will follow from a positive or negative test result.
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