1,720,965 research outputs found
Alterations in cerebrospinal fluid levels of myelin- and oligodendrocyte-related proteins in sporadic Creutzfeldt–Jakob disease
No full textAbstract Recent evidence suggests glial dysfunction, particularly involving oligodendrocytes and myelin, as an important part of the primary disease mechanism of sporadic Creutzfeldt–Jakob disease. To the best of our knowledge, cerebrospinal fluid (CSF) biomarkers reflecting oligodendrocyte or myelin damage have not yet been systematically investigated in this context. CSF samples from patients with sporadic Creutzfeldt–Jakob disease (CJD), Alzheimer's disease (AD) and non-neurodegenerative controls (n = 18, respectively) were included in the study, and levels of myelin basic protein (MBP), neural/glial antigen 2 (NG2) and cyclic nucleotide 3′-phosphodiesterase (CNPase) were quantified. Additionally, p25-positive cells were quantified in autopsy tissue from the frontal and parietal cortical regions of five patients with CJD and four controls. In the primary cohort, MBP quantification revealed significantly higher CSF levels in CJD compared to AD (p = 0.004) and controls (p = 0.0001) and this difference remained significant after adjustment for age and neurofilament light chain (NfL), indicating that MBP elevations cannot be explained solely by neuroaxonal degeneration. Significant differences were also found for CNPase in CJD compared to AD (p = 0.0011) and controls (p = 0.0004). There were no differences in NG2 levels (p > 0.05) among the groups. However, no significant differences were observed in the total number of p25-positive mature oligodendrocytes between CJD and controls in cortical brain tissue (p > 0.05). Additionally, MBP and NfL were quantified in a second cohort of 28 CJD and 20 biomarker-defined AD patients. In this cohort, characterized by more advanced AD pathology, MBP strongly covaried with NfL and no longer differed between diagnostic groups, suggesting a greater influence of neuroaxonal injury on MBP levels in advanced disease stages. In conclusion, in CJD, MBP elevations appear to be only partly related to neuroaxonal degeneration and may reflect disease-related myelin involvement
Cerebrospinal Fluid Iron‐Ferritin Ratio as a Potential Progression Marker for Parkinson's Disease
No full textDetection of Cerebrospinal Fluid Neurofilament Light Chain as a Marker for Alpha-Synucleinopathies
Full text linkAlpha-synucleinopathies, such as Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), are a class of neurodegenerative diseases. A diagnosis may be challenging because clinical symptoms partially overlap, and there is currently no reliable diagnostic test available. Therefore, we aimed to identify a suitable marker protein in cerebrospinal fluid (CSF) to distinguish either between different types of alpha-synucleinopathies or between alpha-synucleinopathies and controls. In this study, the regulation of different marker protein candidates, such as alpha-synuclein (a-Syn), neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and total tau (tau) in different types of alpha-synucleinopathies, had been analyzed by using an ultrasensitive test system called single-molecule array (SIMOA). Interestingly, we observed that CSF-NfL was significantly elevated in patients with DLB and MSA compared to patients with PD or control donors. To differentiate between groups, receiver operating characteristic (ROC) curve analysis resulted in a very good diagnostic accuracy as indicated by the area under the curve (AUC) values of 0.87-0.92 for CSF-NfL. Furthermore, we observed that GFAP and tau were slightly increased either in DLB or MSA, while a-Syn levels remained unregulated. Our study suggests NfL as a promising marker to discriminate between different types of alpha-synucleinopathies or between DLB/MSA and controls
Myelin basic protein and TREM2 quantification in the CSF of patients with Multiple System Atrophy and other Parkinsonian conditions
No full textAbstract Background It is well known that myelin disruption and neuroinflammation are early and distinct pathological hallmarks in multiple system atrophy (MSA) as well as in idiopathic Parkinson’s disease and in other atypical Parkinsonian syndromes. The objective of this study was to assess the value of non-neuronal biomarker candidates that reflect myelin disruption and neuroinflammation. Methods Myelin basic protein (MBP) and the soluble form of TREM2 were quantified in a comprehensive movement disorder cohort from two different neurological centers, comprising a total of 171 CSF samples. Commercially available ELISA systems were employed for quantification. Results The results of the MBP analysis revealed a significant increase in cerebrospinal fluid (CSF) MBP levels in all atypical Parkinsonian conditions compared to PD. This differentiation was more pronounced in the MSA-c subtype compared to MSA-p. Receiver operating characteristic (ROC) analysis revealed a significant discrimination between PD and MSA ( p = 0.032, AUC = 0.70), PD and DLB ( p = 0.006, AUC = 0.79) and PD and tauopathies ( p = 0.006, AUC = 0.74). The results of the TREM2 analysis demonstrated no significant differences between the PD and atypical Parkinsonian groups if not adjusted for confounders. After adjusting for age, sex, and disease duration, the PD group exhibited significantly higher TREM2 levels compared to the DLB group ( p = 0.002). Conclusions In conclusion, MBP, but not TREM2, is elevated in the CSF of not only MSA but in all atypical Parkinsonian conditions compared to idiopathic Parkinson’s disease. This highlights the value of the evaluation of myelin/oligodendrocyte-associated markers in neurodegenerative movement disorders
α-Synuclein conformers reveal link to clinical heterogeneity of α-synucleinopathies
No full textAbstract
α-Synucleinopathies, such as Parkinson’s disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy, are a class of neurodegenerative diseases exhibiting intracellular inclusions of misfolded α-synuclein (αSyn), referred to as Lewy bodies or oligodendroglial cytoplasmic inclusions (Papp–Lantos bodies). Even though the specific cellular distribution of aggregated αSyn differs in PD and DLB patients, both groups show a significant pathological overlap, raising the discussion of whether PD and DLB are the same or different diseases. Besides clinical investigation, we will focus in addition on methodologies, such as protein seeding assays (real-time quaking-induced conversion), to discriminate between different types of α-synucleinopathies. This approach relies on the seeding conversion properties of misfolded αSyn, supporting the hypothesis that different conformers of misfolded αSyn may occur in different types of α-synucleinopathies. Understanding the pathological processes influencing the disease progression and phenotype, provoked by different αSyn conformers, will be important for a personalized medical treatment in future.Open-Access-Publikationsfonds 202
Detection of alpha-synuclein seeding activity in tear fluid in patients with Parkinson’s disease
No full textAbstract Detection of alpha-synuclein (α-Syn) seeding activity in tear fluid (TF) offers a promising non-invasive biomarker for Parkinson’s disease (PD). α-Syn seeding amplification assay (αSynSAA) detected seeding activity in 67% of PD-TF, while non-synucleinopathy samples remained negative. Electron microscopy of seeding-positive end products revealed fibrillar structures morphologically consistent with results of αSynSAA. αSynSAA effectively distinguished PD from controls and prion diseases based on seeding activity in TF
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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