1. |
- Adori, Csaba, et al.
(författare)
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Neuropeptide S- and Neuropeptide S receptor-expressing neuron populations in the human pons
- 2015
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Ingår i: Frontiers in Neuroanatomy. - : Frontiers Media SA. - 1662-5129. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Neuropeptide S (NPS) is a regulatory peptide with potent pharmacological effects. In rodents, NPS is expressed in a few pontine cell clusters. Its receptor (NPSR1) is, however, widely distributed in the brain. The anxiolytic and arousal promoting effects of NPS make the NPS NPSR1 system an interesting potential drug target in mood-related disorders. However, so far possible disease-related mechanisms involving NPS have only been studied in rodents. To validate the relevance of these animal studies for i.a. drug development, we have explored the distribution of NPS-expressing neurons in the human pons using in situ hybridization and stereological methods and we compared the distribution of NPS mRNA expressing neurons in the human and rat brain. The calculation revealed a total number of 22,317 +/- 2411 NPS mRNA-positive neurons in human, bilaterally. The majority of cells (84%) were located in the parabrachial area in human: in the extension of the medial and lateral parabrachial nuclei, in the Kolliker-Fuse nucleus and around the adjacent lateral lemniscus. In human, in sharp contrast to the rodents, only very few NPS-positive cells (5%) were found close to the locus coeruleus. In addition, we identified a smaller cell cluster (11% of all NPS cells) in the pontine central gray matter both in human and rat, which has not been described previously even in rodents. We also examined the distribution of NPSR1 mRNA-expressing neurons in the human pons. These cells were mainly located in the rostral laterodorsal tegmental nucleus, the cuneiform nucleus, the microcellular tegmental nucleus region and in the periaqueductal gray. Our results show that both NPS and NPSR1 in the human pons are preferentially localized in regions of importance for integration of visceral autonomic information and emotional behavior. The reported interspecies differences must, however, be considered when looking for targets for new pharmacotherapeutical interventions.
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2. |
- Alafuzoff, Irina, et al.
(författare)
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Assessment of alpha-synuclein pathology : a study of the BrainNet Europe Consortium.
- 2008
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Ingår i: Journal of Neuropathology and Experimental Neurology. - : Oxford University Press (OUP). - 0022-3069 .- 1554-6578. ; 67:2, s. 125-43
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Tidskriftsartikel (refereegranskat)abstract
- To determine the reliability of assessment of alpha-synuclein-immunoreactive (alphaS-IR) structures by neuropathologists, 28 evaluators from 17 centers of BrainNet Europe examined current methods and reproducibility of alphaS-IR evaluation using a tissue microarray (TMA) technique. Tissue microarray blocks were constructed of samples from the participating centers that contained alphaS-IR structures. Slides from these blocks were stained in each center and assessed for neuronal perikaryal inclusions, neurites, and glial cytoplasmic inclusions. The study was performed in 2 phases. First, the TMA slides were stained with the antibody of the center's choice. In this phase, 59% of the sections were of good or acceptable quality, and 4 of 9 antibodies used performed consistently. Differences in interpretation and categorization of alphaS-IR structures, however, led to differing results between the laboratories. Prior to the second phase, the neuropathologists participated in a training session on the evaluation of alphaS-IR structures. Based on the results of the first phase, selected antibodies using designated antigen retrieval methods were then applied to TMA slides in the second phase. When the designated methods of both staining and evaluation were applied, all 26 subsequently stained TMA sections evaluated were of good/acceptable quality, and a high level of concordance in the assessment of the presence or absence of specific alphaS-IR structures was achieved. A semiquantitative assessment of alphaS-IR neuronal perikaryal inclusions yielded agreements ranging from 49% to 82%, with best concordance in cortical core samples. These results suggest that rigorous methodology and dichotomized assessment (i.e. determining the presence or absence of alphaS-IR) should be applied, and that semiquantitative assessment can be recommended only for the cortical samples. Moreover, the study demonstrates that there are limitations in the scoring of alphaS-IR structures.
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3. |
- Alafuzoff, Irina, et al.
(författare)
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Assessment of beta-amyloid deposits in human brain : a study of the BrainNet Europe Consortium
- 2009
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 117:3, s. 309-320
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Tidskriftsartikel (refereegranskat)abstract
- beta-Amyloid (A-beta) related pathology shows a range of lesions which differ both qualitatively and quantitatively. Pathologists, to date, mainly focused on the assessment of both of these aspects but attempts to correlate the findings with clinical phenotypes are not convincing. It has been recently proposed in the same way as iota and alpha synuclein related lesions, also A-beta related pathology may follow a temporal evolution, i.e. distinct phases, characterized by a step-wise involvement of different brain-regions. Twenty-six independent observers reached an 81% absolute agreement while assessing the phase of A-beta, i.e. phase 1 = deposition of A-beta exclusively in neocortex, phase 2 = additionally in allocortex, phase 3 = additionally in diencephalon, phase 4 = additionally in brainstem, and phase 5 = additionally in cerebellum. These high agreement rates were reached when at least six brain regions were evaluated. Likewise, a high agreement (93%) was reached while assessing the absence/presence of cerebral amyloid angiopathy (CAA) and the type of CAA (74%) while examining the six brain regions. Of note, most of observers failed to detect capillary CAA when it was only mild and focal and thus instead of type 1, type 2 CAA was diagnosed. In conclusion, a reliable assessment of A-beta phase and presence/absence of CAA was achieved by a total of 26 observers who examined a standardized set of blocks taken from only six anatomical regions, applying commercially available reagents and by assessing them as instructed. Thus, one may consider rating of A-beta-phases as a diagnostic tool while analyzing subjects with suspected Alzheimer's disease (AD). Because most of these blocks are currently routinely sampled by the majority of laboratories, assessment of the A-beta phase in AD is feasible even in large scale retrospective studies.
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4. |
- Alafuzoff, Irina, et al.
(författare)
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Neuropathological assessments of the pathology in frontotemporal lobar degeneration with TDP43-positive inclusions : an inter-laboratory study by the BrainNet Europe consortium
- 2015
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Ingår i: Journal of neural transmission. - : Springer Science and Business Media LLC. - 0300-9564 .- 1435-1463. ; 122:7, s. 957-972
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Tidskriftsartikel (refereegranskat)abstract
- The BrainNet Europe consortium assessed the reproducibility in the assignment of the type of frontotemporal lobar degeneration (FTLD) with TAR DNA-binding protein (TDP) 43 following current recommendations. The agreement rates were influenced by the immunohistochemical (IHC) method and by the classification strategy followed. p62-IHC staining yielded good uniform quality of stains, but the most reliable results were obtained implementing specific Abs directed against the hallmark protein TDP43. Both assessment of the type and the extent of lesions were influenced by the Abs and by the quality of stain. Assessment of the extent of the lesions yielded poor results repeatedly; thus, the extent of pathology should not be used in diagnostic consensus criteria. Whilst 31 neuropathologists typed 30 FTLD-TDP cases, inter-rater agreement ranged from 19 to 100 per cent, being highest when applying phosphorylated TDP43/IHC. The agreement was highest when designating Type C or Type A/B. In contrast, there was a poor agreement when attempting to separate Type A or Type B FTLD-TDP. In conclusion, we can expect that neuropathologist, independent of his/her familiarity with FTLD-TDP pathology, can identify a TDP43-positive FTLD case. The goal should be to state a Type (A, B, C, D) or a mixture of Types (A/B, A/C or B/C). Neuropathologists, other clinicians and researchers should be aware of the pitfalls whilst doing so. Agreement can be reached in an inter-laboratory setting regarding Type C cases with thick and long neurites, whereas the differentiation between Types A and B may be more troublesome.
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5. |
- Alafuzoff, Irina, et al.
(författare)
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Staging of neurofibrillary pathology in Alzheimer's disease : a study of the BrainNet Europe Consortium.
- 2008
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Ingår i: Brain Pathology. - : Wiley. - 1015-6305 .- 1750-3639. ; 18:4, s. 484-96
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Tidskriftsartikel (refereegranskat)abstract
- It has been recognized that molecular classifications will form the basis for neuropathological diagnostic work in the future. Consequently, in order to reach a diagnosis of Alzheimer's disease (AD), the presence of hyperphosphorylated tau (HP-tau) and beta-amyloid protein in brain tissue must be unequivocal. In addition, the stepwise progression of pathology needs to be assessed. This paper deals exclusively with the regional assessment of AD-related HP-tau pathology. The objective was to provide straightforward instructions to aid in the assessment of AD-related immunohistochemically (IHC) detected HP-tau pathology and to test the concordance of assessments made by 25 independent evaluators. The assessment of progression in 7-microm-thick sections was based on assessment of IHC labeled HP-tau immunoreactive neuropil threads (NTs). Our results indicate that good agreement can be reached when the lesions are substantial, i.e., the lesions have reached isocortical structures (stage V-VI absolute agreement 91%), whereas when only mild subtle lesions were present the agreement was poorer (I-II absolute agreement 50%). Thus, in a research setting when the extent of lesions is mild, it is strongly recommended that the assessment of lesions should be carried out by at least two independent observers.
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6. |
- Alafuzoff, Irina, et al.
(författare)
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Staging/typing of Lewy body related alpha-synuclein pathology : a study of the BrainNet Europe Consortium
- 2009
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 117:6, s. 635-652
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Tidskriftsartikel (refereegranskat)abstract
- When 22 members of the BrainNet Europe (BNE) consortium assessed 31 cases with alpha-synuclein (alphaS) immunoreactive (IR) pathology applying the consensus protocol described by McKeith and colleagues in 2005, the inter-observer agreement was 80%, being lowest in the limbic category (73%). When applying the staging protocol described by Braak and colleagues in 2003, agreement was only 65%, and in some cases as low as 36%. When modifications of these strategies, i.e., McKeith's protocol by Leverenz and colleagues from 2009, Braak's staging by Müller and colleagues from 2005 were applied then the agreement increased to 78 and 82%, respectively. In both of these modifications, a reduced number of anatomical regions/blocks are assessed and still in a substantial number of cases, the inter-observer agreement differed significantly. Over 80% agreement in both typing and staging of alphaS pathology could be achieved when applying a new protocol, jointly designed by the BNE consortium. The BNE-protocol assessing alphaS-IR lesions in nine blocks offered advantages over the previous modified protocols because the agreement between the 22 observers was over 80% in most cases. Furthermore, in the BNE-protocol, the alphaS pathology is assessed as being present or absent and thus the quality of staining and the assessment of the severity of alphaS-IR pathology do not alter the inter-observer agreement, contrary to other assessment strategies. To reach these high agreement rates an entity of amygdala-predominant category was incorporated. In conclusion, here we report a protocol for assessing alphaS pathology that can achieve a high inter-observer agreement for both the assignment to brainstem, limbic, neocortical and amygdala-predominant categories of synucleinopathy and the Braak stages.
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7. |
- Andersson, Malin E, 1978, et al.
(författare)
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Kinesin gene variability may affect tau phosphorylation in early Alzheimer's disease.
- 2007
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Ingår i: International journal of molecular medicine. - 1107-3756 .- 1791-244X. ; 20:2, s. 233-9
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Tidskriftsartikel (refereegranskat)abstract
- Kinesin is a microtubule-associated motor protein that transports Alzheimer-associated amyloid precursor protein (APP) in neurons. In animal models, impaired kinesin-mediated APP transport seems to enhance formation of the neurotoxic 42 amino acid fragment of beta-amyloid (A beta 42). In man, one study suggests that a polymorphism (rs8702, 56,836G>C) in the kinesin light chain 1 gene (KNS2) may affect the risk of Alzheimer's disease (AD). To further assess KNS2 as a susceptibility gene for AD we analyzed 802 patients with sporadic AD and 286 controls, 134 longitudinally followed patients with mild cognitive impairment (MCI) and 39 cognitively stable controls for the rs8702 polymorphism. The rs8702 polymorphism did not influence risk of AD (p=0.46). However, rs8702 interacted with APOE epsilon 4 carrier status in AD (p=0.006) and influenced cerebrospinal fluid levels of hyperphosphorylated tau in MCI patients who converted to AD during follow-up (p=0.018). These findings support earlier indications that genetic variability in the KNS2 gene may play a role during early stages of AD pathogenesis.
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8. |
- Ausén, Birgitta, et al.
(författare)
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Personality Features in Subjective Cognitive Impairment and Mild Cognitive Impairment - Early Indicators of Dementia?
- 2009
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Ingår i: Dementia and Geriatric Cognitive Disorders. - Basel : Karger AG. - 1420-8008 .- 1421-9824. ; 28:6, s. 528-535
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The purpose of the present study was to investigate patterns of personality in patients with subjective cognitive impairment (SCI) and mild cognitive impairment (MCI), compared to healthy controls. Methods: We assessed24 patients with SCI, 35 patients with MCI and 26 healthy controls with the self-report questionnaire Swedish Universities Scales of Personality measuring aspects of neuroticism/anxiety proneness, extraversion, and aggression-hostility. Results: Patients with SCI and MCI showed significantly more Somatic Trait Anxiety, Psychic Trait Anxiety and Stress Susceptibility than healthy controls. Moreover, there was a significant increase in Detachment in patients with MCI and a significant decrease in Adventure Seeking in patients with SCI, relative to healthy controls. Conclusions: Patients with SCI and MCI presented specific patterns of personality alterations with higher scores in traits related to anxiety proneness and aggression-hostility and lower in traits of extraversion. In most subscales differences followed a sequential pattern with gradually increasing scores from healthy controls, to patients with SCI and further to MCI. The groups differed in amount and type of symptoms, suggesting that patterns of personality may be related to degree of cognitive impairment.
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9. |
- Ausen, Birgitta, et al.
(författare)
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Self- and Informant Ratings of Personality in Mild Cognitive Impairment, Reviewed
- 2011
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 32:6, s. 387-393
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To examine the degree of agreement between self-and informant ratings of personality in relation to cognitive function in patients with mild cognitive impairment (MCI), subjective cognitive impairment (SCI) and healthy controls (HC). Methods: Thirty-two patients and informants with MCI, 23 with SCI and 22 HC completed the Swedish universities Scales of Personality (SSP). Correlations and incongruence between self-and informant ratings were calculated. The Mini Mental State Examination (MMSE) was used to assess cognitive function. Results: The correlations between self-and and informant ratings were fair-to-moderate on a majority of SSP scales and significant in 44%. The incongruence between patients and informants was significantly larger in MCI than in HC across SSP scales. There was a significant negative correlation between the incongruence index and the MMSE for all subjects. Conclusions: Self-informant agreement on ratings of patients' personality was reasonable. Incongruence between patients and their informants was associated with MCI but not SCI or HC. Disagreement between patients and informants indicates cognitive impairment. Copyright (C) 2012 S. Karger AG, Basel
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10. |
- Bell, Jeanne E, et al.
(författare)
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Management of a twenty-first century brain bank : experience in the BrainNet Europe consortium.
- 2008
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 115:5, s. 497-507
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Tidskriftsartikel (refereegranskat)abstract
- Collections of human postmortem brains gathered in brain banks have underpinned many significant developments in the understanding of central nervous system (CNS) disorders and continue to support current research. Unfortunately, the worldwide decline in postmortem examinations has had an adverse effect on research tissue procurement, particularly from control cases (non-diseased brains). Recruitment to brain donor programmes partially addresses this problem and has been successful for dementing and neurodegenerative conditions. However, the collection of brains from control subjects, particularly from younger individuals, and from CNS disorders of sudden onset, remains a problem. Brain banks need to adopt additional strategies to circumvent such shortages. The establishment of brain bank networks allows data on, and access to, control cases and unusual CNS disorders to be shared, providing a larger resource for potential users. For the brain banks themselves, inclusion in a network fosters the sharing of protocols and development of best practice and quality control. One aspect of this collective experience concerns brain bank management, excellence in which is a prerequisite not only for gaining the trust of potential donors and of society in general, but also for ensuring equitable distribution to researchers of high quality tissue samples. This review addresses the legal, ethical and governance issues, tissue quality, and health and safety aspects of brain bank management and data management in a network, as well as the needs of users, brain bank staffing, donor programs, funding issues and public relations. Recent developments in research methodology present new opportunities for researchers who use brain tissue samples, but will require brain banks to adopt more complex protocols for tissue collection, preparation and storage, with inevitable cost implications for the future.
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11. |
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12. |
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13. |
- Blomqvist, Mia E-L, et al.
(författare)
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Towards compendia of negative genetic association studies: an example for Alzheimer disease.
- 2006
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Ingår i: Human genetics. - : Springer Science and Business Media LLC. - 0340-6717 .- 1432-1203. ; 119:1-2, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- Most genetic sequence variants that contribute to variability in complex human traits will have small effects that are not readily detectable with population samples typically used in genetic association studies. A potentially valuable tool in the gene discovery process is meta-analysis of the accumulated published data, but in order to be valid these require a sample of studies representative of the true genetic effect and thus hypothetically should include some positive and an abundance of negative reports. A survey of the literature on association studies for Alzheimer disease (AD) from January 2004-April 2005, identified 138 studies, 86 of which reported positive findings other than for apolipoprotein E (APOE), strongly indicative of publication bias. We report here an analysis of 62 genetic markers, tested for association with AD risk as well as for possible effects upon quantitative indices of AD severity (mini-mental state examination scores, age-at-onset, and cerebrospinal fluid (CSF) beta-amyloid (Abeta) and CSF tau proteins). Within this set, only modest signals were present that, with the exception of APOE are easily lost when corrections for multiple hypotheses are applied. In isolation, results are thus broadly negative. Genes studied encompass both novel candidates as well as several recently claimed to be associated with AD (e.g. urokinase plasminogen activator (PLAU) and acetyl-coenzyme A acetyltransferase 1 (ACAT1)). By reporting these data we hope to encourage the publication of gene compendia to guide further studies and aid future meta-analyses aimed at resolving the involvement of genes in complex human traits.
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14. |
- Bogdanovic, Nenad, et al.
(författare)
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[Alzheimer's disease - the most common cause of dementia]. : Alzheimers sjukdom – diagnostik och behandling i dag och i framtiden.
- 2020
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Ingår i: Lakartidningen. - 1652-7518. ; 117
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease is the most common cause of dementia. As many as 250,000 people in Sweden will have a dementia disease in 2050. The »amyloid cascade hypothesis« is a common model which explains how β-amyloid affects the function of the nerve cells. Alzheimer's disease has a long-lasting course and can present in typical and atypical forms. CSF analyses for »core AD CSF biomarkers« and synaptic proteins have been available for clinical diagnostics. PET scanning can detect either β-amyloid or tau aggregates in the brain of living humans. Current Alzheimer's disease therapy is based on two classes of cognition-enhancing drugs: acetylcholinesterase inhibitor and NMDA-receptor antagonist, which delays cognitive decline in most patients. The latest clinical development of potential therapy for Alzheimer's is active or passive immunotherapy against brain β-amyloid and tau, where several studies have shown varying but promising treatment effects. Non-pharmacological interventions in patients with AD aim to delay the loss of mental abilities, helping people to be independent in everyday life for as long as possible, and to increase their well-being and quality of life.
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15. |
- Bogdanovic, Nenad
(författare)
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Alzheimer's disease : towards a multifaceted approach in neuropathological diagnosis
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main aim of this study has been to investigate potential neuropathological features which may play an important role in understanding the cognitive dysfunction and in making the final diagnosis of Alzheimer's disease (AD). To establish a reliable diagnosis of AD, standardisation and uniformity of the diagnostic protocols must become mandatory. Among several currently used neuropathological criteria for AD, the Consortium to Establish a Registry of Alzheimer's Disease (CERAD) protocol has been shown to provide the best overall correlation between cognitive decline and neuritic plaques as one of the neuropathological hallmarks of disease. Post-mortem neuropathological analyses on brains of drivers who died in traffic accidents, showed AD related changes in more than 50% of the cases, suggesting that the CERAD approach is useful for studying neuropathological changes in such populations, and that AD-related cognitive impairment seems to be an important risk factor in elderly drivers. To study the neuronal degeneration in the hippocampal formation, we applied the stereological, optical dissector, technique. We found that ageing is characterised by neuronal degeneration in CAI and subicular regions, while in AD, the dentate granular cells and subiculum are mostly affected, suggesting that the type of neuronal degeneration in AD differs from that found in normal ageing. Using standardised brain sampling, dissection, and staining procedures, we found that neurofibrillary changes in cases with the early-onset AD "Swedish" double mutation on chromosome 21 follow the same pattern of neuropathological distribution as in late-onset AD. Possession of the apoE e4 allele modified the amount of pathology, and decreased the onset, but not the duration, of the disease. Further, the specific areal and laminar distribution of the neurofibrillary changes indicate degeneration of distinct neuronal populations and projection systems. In parallel with neuronal degeneration, synaptic degeneration and loss are associated with brain dysfunction. To study synaptic function in the normal human brain we performed both quantitative and immunohistochemical analyses of the regional and cellular distribution of synaptophysin, rab3a, synaptotagmin, growth associated protein GAP-43 and neurogranin. Synaptic protein density significantly varied between different cortical and subcortical regions, and specific patterns of laminar staining in the cortex and hippocampus was found for the different proteins, supporting the hypothesis that different molecular mechanisms for both synaptic plasticity and neurotransmitter release might operate in distinct neuronal circuits. In AD, synaptic loss and regenerative processes were studied using the synaptic proteins rab3a and GAP-43 as markers. Synaptic density was decreased in the frontal cortex and the hippocampus in AD, and correlated with the clinical status, but not with neurofibrillary tangles or senile plaques, supporting that synaptic pathology is an important event in AD, which might be independent of other types of pathology. Although a general decrease was found also for GAP-43, specific subfields of the hippocampus showed an increased GAP-43 staining, suggesting that aberrant sprouting and regenerative phenomena in AD brain shows a regional and cellular specificity, and do not always occur in parallel to synaptic degeneration. In conclusion, the selection of appropriate markers, brain tissue sampling and methodology could increase the diagnostic accuracy. To define the morphological substrate of cognitive impairment in AD we consider that it is imperative to establish a multifaceted approach for analysis of neuronal and synaptic degeneration, and neurofibrillary changes.
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16. |
- Bogdanovic, Nenad, et al.
(författare)
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Alzheimers sjukdom – diagnostik och behandling i dag och i framtiden
- 2020
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Ingår i: Läkartidningen. - 0023-7205. ; 117
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease is the most common cause of dementia. As many as 250,000 people in Sweden will have a dementia disease in 2050. The »amyloid cascade hypothesis« is a common model which explains how β-amyloid affects the function of the nerve cells. Alzheimer's disease has a long-lasting course and can present in typical and atypical forms. CSF analyses for »core AD CSF biomarkers« and synaptic proteins have been available for clinical diagnostics. PET scanning can detect either β-amyloid or tau aggregates in the brain of living humans. Current Alzheimer's disease therapy is based on two classes of cognition-enhancing drugs: acetylcholinesterase inhibitor and NMDA-receptor antagonist, which delays cognitive decline in most patients. The latest clinical development of potential therapy for Alzheimer's is active or passive immunotherapy against brain β-amyloid and tau, where several studies have shown varying but promising treatment effects. Non-pharmacological interventions in patients with AD aim to delay the loss of mental abilities, helping people to be independent in everyday life for as long as possible, and to increase their well-being and quality of life.
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17. |
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18. |
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19. |
- Daniilidou, Makrina, et al.
(författare)
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Alzheimer's disease biomarker profiling in a memory clinic cohort without common comorbidities.
- 2023
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Ingår i: Brain communications. - 2632-1297. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease is a multifactorial disorder with large heterogeneity. Comorbidities such as hypertension, hypercholesterolaemia and diabetes are known contributors to disease progression. However, less is known about their mechanistic contribution to Alzheimer's pathology and neurodegeneration. The aim of this study was to investigate the relationship of several biomarkers related to risk mechanisms in Alzheimer's disease with the well-established Alzheimer's disease markers in a memory clinic population without common comorbidities. We investigated 13 molecular markers representing key mechanisms underlying Alzheimer's disease pathogenesis in CSF from memory clinic patients without diagnosed hypertension, hypercholesterolaemia or diabetes nor other neurodegenerative disorders. An analysis of covariance was used to compare biomarker levels between clinical groups. Associations were analysed by linear regression. Two-step cluster analysis was used to determine patient clusters. Two key markers were analysed by immunofluorescence staining in the hippocampus of non-demented control and Alzheimer's disease individuals. CSF samples from a total of 90 participants were included in this study: 30 from patients with subjective cognitive decline (age 62.4 ± 4.38, female 60%), 30 with mild cognitive impairment (age 65.6 ± 7.48, female 50%) and 30 with Alzheimer's disease (age 68.2 ± 7.86, female 50%). Angiotensinogen, thioredoxin-1 and interleukin-15 had the most prominent associations with Alzheimer's disease pathology, synaptic and axonal damage markers. Synaptosomal-associated protein 25kDa and neurofilament light chain were increased in mild cognitive impairment and Alzheimer's disease patients. Grouping biomarkers by biological function showed that inflammatory and survival components were associated with Alzheimer's disease pathology, synaptic dysfunction and axonal damage. Moreover, a vascular/metabolic component was associated with synaptic dysfunction. In the data-driven analysis, two patient clusters were identified: Cluster 1 had increased CSF markers of oxidative stress, vascular pathology and neuroinflammation and was characterized by elevated synaptic and axonal damage, compared with Cluster 2. Clinical groups were evenly distributed between the clusters. An analysis of post-mortem hippocampal tissue showed that compared with non-demented controls, angiotensinogen staining was higher in Alzheimer's disease and co-localized with phosphorylated-tau. The identification of biomarker-driven endophenotypes in cognitive disorder patients further highlights the biological heterogeneity of Alzheimer's disease and the importance of tailored prevention and treatment strategies.
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20. |
- Darmopil, Sanja, et al.
(författare)
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Environmental enrichment alters dentate granule cell morphology in oldest-old rat
- 2009
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Ingår i: Journal of Cellular and Molecular Medicine (Print). - : Blackwell Publishing. - 1582-1838 .- 1582-4934. ; 13:8b, s. 1845-1856
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampus of aged rats shows marked age-related morphological changes that could cause memory deficits. Experimental evidence has established that environmental enrichment attenuates memory deficits in aged rats. We therefore studied whether environmental enrichment produces morphological changes on the dentate granule cells of aged rats. Fifteen male Sprague-Dawley rats, 24 months of age, were randomly distributed in two groups that were housed under standard (n= 7) or enriched (n= 8) environmental conditions for 26 days. Quantitative data of dendritic morphology from dentate gyrus granule cells were obtained on Golgi–Cox stained sections. Environmental enrichment significantly increased the complexity and size of dendritic tree (total number of segments increased by 61% and length by 116%), and spine density (88% increase). There were large interindividual differences within the enriched group, indicating differential individual responses to environmental stimulation. Previous studies in young animals have shown changes produced by environmental enrichment in the morphology of dentate gyrus granule cells. The results of the present study show that environmental enrichment can also produce changes in dentate granule cell morphology in the senescent brain. In conclusion, the hippocampus retains its neuroplastic capacity during aging, and enriched environmental housing conditions can attenuate age-related dendritic regression and synaptic loss, thus preserving memory functions.
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21. |
- Eriksdotter-Jönhagen, Maria, et al.
(författare)
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Encapsulated cell biodelivery of nerve growth factor to the Basal forebrain in patients with Alzheimer's disease.
- 2012
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 33:1, s. 18-28
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Tidskriftsartikel (refereegranskat)abstract
- Degeneration of cholinergic neurons in the basal forebrain correlates with cognitive decline in patients with Alzheimer's disease (AD). Targeted delivery of exogenous nerve growth factor (NGF) has emerged as a potential AD therapy due to its regenerative effects on the basal forebrain cholinergic neurons in AD animal models. Here we report the results of a first-in-man study of encapsulated cell (EC) biodelivery of NGF to the basal forebrain of AD patients with the primary objective to explore safety and tolerability.
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22. |
- Gallagher, Michael D., et al.
(författare)
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TMEM106B is a genetic modifier of frontotemporal lobar degeneration with C9orf72 hexanucleotide repeat expansions
- 2014
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 127:3, s. 407-418
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Tidskriftsartikel (refereegranskat)abstract
- Hexanucleotide repeat expansions in chromosome 9 open reading frame 72 (C9orf72) have recently been linked to frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis, and may be the most common genetic cause of both neurodegenerative diseases. Genetic variants at TMEM106B influence risk for the most common neuropathological subtype of FTLD, characterized by inclusions of TAR DNA-binding protein of 43 kDa (FTLD-TDP). Previous reports have shown that TMEM106B is a genetic modifier of FTLD-TDP caused by progranulin (GRN) mutations, with the major (risk) allele of rs1990622 associating with earlier age at onset of disease. Here, we report that rs1990622 genotype affects age at death in a single-site discovery cohort of FTLD patients with C9orf72 expansions (n = 14), with the major allele correlated with later age at death (p = 0.024). We replicate this modifier effect in a 30-site international neuropathological cohort of FTLD-TDP patients with C9orf72 expansions (n = 75), again finding that the major allele associates with later age at death (p = 0.016), as well as later age at onset (p = 0.019). In contrast, TMEM106B genotype does not affect age at onset or death in 241 FTLD-TDP cases negative for GRN mutations or C9orf72 expansions. Thus, TMEM106B is a genetic modifier of FTLD with C9orf72 expansions. Intriguingly, the genotype that confers increased risk for developing FTLD-TDP (major, or T, allele of rs1990622) is associated with later age at onset and death in C9orf72 expansion carriers, providing an example of sign epistasis in human neurodegenerative disease.
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23. |
- Idland, Ane Victoria, et al.
(författare)
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Preclinical amyloid-β and axonal degeneration pathology in delirium
- 2016
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 55:1, s. 371-379
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Tidskriftsartikel (refereegranskat)abstract
- Background: The clinical relevance of brain β-amyloidosis in older adults without dementia is not established. As delirium and dementia are strongly related, studies on patients with delirium may give pathophysiological clues. Objective: To determine whether the Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers amyloid-β 1-42 (Aβ42), total tau (T-tau), and phosphorylated tau (P-tau) are associated with delirium in hip fracture patients with and without dementia. Methods: CSF was collected in conjunction to spinal anesthesia in 129 patients. Delirium was assessed using the Confusion Assessment Method once daily in all patients, both pre- and postoperatively. The diagnosis of dementia at admission was based upon clinical consensus. CSF levels of Aβ42, T-tau, and P-tau were analyzed. Results: In patients without dementia, we found lower CSF Aβ42 levels (median, 310ng/L versus 489ng/L, p=0.006), higher T-tau levels (median, 505ng/L versus 351ng/L, p=0.02), but no change in P-tau in patients who developed delirium (n=16) compared to those who remained lucid (n=49). Delirious patients also had lower ratios of Aβ42 to T-tau (p<0.001) and P-tau (p=0.001) relative to those without delirium. CSF Aβ42 and T-tau remained significantly associated with delirium status in adjusted analyses. In patients with dementia, CSF biomarker levels did not differ between those with (n=54) and without delirium (n=10). Conclusion: The reduction in CSF Aβ42, indicating β-amyloidosis, and increase in T-tau, indicating neurodegeneration, in hip fracture patients without dementia developing delirium indicates that preclinical AD brain pathology is clinically relevant and possibly plays a role in delirium pathophysiology.
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24. |
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25. |
- Johansson, Annica, 1969, et al.
(författare)
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CYP46A1 Variants Interact with Age and APOE to Influence CSF Aβ42 and Phospho-Tau Levels in Alzheimer's Disease
- 2004
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Ingår i: The 9th International Conference on Alzheimer's Disease (ICAD), Philadelphia, Pennsylvania, USA, 20-25 July 2004.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Recent studies have suggested that variants of CYP46A1, encoding cholesterol 24-hydroxylase (CYP46), confer risk to Alzheimer's disease (AD), a prospect substantiated by evidence of genetic association with several quantitative traits related to AD pathology, including cerebrospinal fluid (CSF) levels of the 42 amino-acid cleavage product of β-amyloid (Aβ42) and the tau protein. In the present study, these claims have been explored by the genotyping of previously associated markers in CYP46A1 in three independent Northern European case-control series encompassing 1323 individuals, which include approximately 400 patients with measures of CSF Aβ42 and phospho-tau protein levels. Tests of association in case-control models revealed limited evidence that CYP46A1 variants contribute to AD risk across these samples. However, models testing for potential effects upon CSF measures suggested possible interaction of an intronic marker (rs754203) with age and APOE genotype. In stratified analyses, significant effects were evident that were restricted to elderly APOE ε4 carriers for both CSF Aβ42 (P = 0.0009) and phospho-tau (P = 0.046). Computational analyses indicate that the rs754203 marker probably does not impact the binding of regulatory factors, suggesting that other polymorphic sites underlie observed associations. Results provide an important independent replication of previous findings, supporting the existence of CYP46A1 sequence variants that contribute to variability in β-amyloid metabolism.
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