| 51. |
- Keller, Lina, et al.
(författare)
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The PSEN1 I143T mutation in a Swedish family with Alzheimer's disease: clinical report and quantification of A beta in different brain regions
- 2010
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Ingår i: European Journal of Human Genetics. - London : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 18:11, s. 1202-1208
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Tidskriftsartikel (refereegranskat)abstract
- Early-onset dominantly inherited forms of Alzheimer's disease (AD) are rare, but studies of such cases have revealed important information about the disease mechanisms. Importantly, mutations in amyloid precursor protein (APP), presenilin 1 (PSEN1) and PSEN2, alter the APP processing and lead to an increased amyloid beta-peptide (A beta) 42/40 ratio. This, together with other studies on pathogenic mechanisms, show that A beta 42 is a major player in the etiology of AD. Here, we present a clinical and neuropathological description of a Swedish family with an I143T mutation in the PSEN1 gene, which gives rise to a severe form of AD. We also performed an extensive investigation on the concentration and distribution of A beta species of different lengths in six brain regions from two mutation carriers. Our study showed that A beta 42 and a longer peptide, A beta 43, were present both in plaque cores and in total amyloid preparations, and were each clearly more frequent than A beta 40 in all examined regions, as shown by both mass spectrometry and immunohistochemistry. European Journal of Human Genetics (2010) 18, 1202-1208; doi: 10.1038/ejhg.2010.107; published online 14 July 2010
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| 52. |
- Kurz, Alexander, et al.
(författare)
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RHAPSODY - Internet-based support for caregivers of people with young onset dementia : program design and methods of a pilot study
- 2016
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Ingår i: International Psychogeriatrics. - : Cambridge University Press. - 1041-6102 .- 1741-203X. ; 28:12, s. 2091-2099
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Tidskriftsartikel (refereegranskat)abstract
- Background: Young Onset Dementia (YOD), defined by first symptoms of cognitive or behavioral decline occurring before the age of 65 years, is relatively rare compared to dementia of later onset, but it is associated with diagnostic difficulty and heavy burden on affected individuals and their informal carers. Existing health and social care structures rarely meet the needs of YOD patients. Internet-based interventions are a novel format of delivering health-related education, counseling, and support to this vulnerable yet underserved group. Methods: The RHAPSODY (Research to Assess Policies and Strategies for Dementia in the Young) project is a European initiative to improve care for people with YOD by providing an internet-based information and skill-building program for family carers. The e-learning program focuses on managing problem behaviors, dealing with role change, obtaining support, and looking after oneself. It will be evaluated in a pilot study in three countries using a randomized unblinded designwith a wait-list control group. Participants will be informal carers of people with dementia in Alzheimer's disease or behavioral-variant Frontotemporal degeneration with an onset before the age of 65 years. The primary outcome will be caregiving self-efficacy after 6 weeks of program use. As secondary outcomes, caregivers' stress and burden, carer health-related quality of life, caring-related knowledge, patient problem behaviors, and user satisfaction will be assessed. Program utilization will be monitored and a health-economic evaluation will also be performed. Conclusions: The RHAPSODY project will add to the evidence on the potential and limitations of a conveniently accessible, user-friendly, and comprehensive internet-based intervention as an alternative for traditional forms of counseling and support in healthcare, aiming to optimize care and support for people with YOD and their informal caregivers.
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| 53. |
- Laukka, Erika J., et al.
(författare)
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Genetic Effects on Old-Age Cognitive Functioning : A Population-Based Study
- 2013
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Ingår i: Psychology and Aging. - : American Psychological Association (APA). - 0882-7974 .- 1939-1498. ; 28:1, s. 262-274
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Tidskriftsartikel (refereegranskat)abstract
- Associations between genotypes and cognitive outcomes may provide clues as to which mechanisms cause individual differences in old-age cognitive performance. We investigated the effects of five polymorphisms on cognitive functioning in a population-based sample of 2,694 persons without dementia (60-102 years). A structural equation model (SEM) was fit to the cognitive data, yielding five specific latent factors (perceptual speed, episodic memory, semantic memory, category fluency, and letter fluency), as well as a global cognitive factor. These factors showed the expected associations with chronological age. Genotyping was performed for five single-nucleotide polymorphisms that have been associated with cognitive performance: APOE (rs429358), COMT (rs4680), BDNF (rs6265), KIBRA (rs17070145), and CLSTN2 (rs6439886). After controlling for age, gender, and education, as well as correcting for multiple comparisons, we observed negative effects of being an APOE ε4 carrier on episodic memory and perceptual speed. Furthermore, being a CLSTN2 TT carrier was associated with poorer semantic memory. For the global factor, the same pattern of results was observed. In addition, being a BDNF any A carrier was associated with better cognitive performance. Also, older age was associated with stronger genetic effects of APOE on global cognition. However, this interaction effect was partly driven by the presence of preclinical dementia cases in our sample. Similarly, excluding future dementia cases attenuated the effects of APOE on episodic memory and global cognition, suggesting that part of the effects of APOE on old-age cognitive performance may be driven by dementia-related processes.
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| 54. |
- Laukka, Erika J., et al.
(författare)
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Microstructural White Matter Properties Mediate the Association between APOE and Perceptual Speed in Very Old Persons without Dementia
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- Background Reduced white matter integrity, as indicated by lower fractional anisotropy (FA) and higher mean diffusivity (MD), has been related to poorer perceptual speed (PS) performance. As the epsilon 4 allele has been associated with lower white matter integrity in old age, this represents a potential mechanism through which APOE may affect PS. Objective To examine whether the association between APOE and PS is mediated by white matter microstructure in very old persons without dementia. Method Participants were selected from the population-based SNAC-K study. After excluding persons with dementia, preclinical dementia, and other neurological disorders, 652 persons (age range 78-90) were included in the study, of which 89 had data on diffusion tensor imaging (DTI). We used structural equation modeling to form seven latent white matter factors (FA and MD) and one latent PS factor. Separate analyses were performed for FA and MD and mediational analyses were carried out for tracts where significant associations were observed to both APOE and PS. Results APOE was associated with white matter microstructure in 2 out of 14 tracts; e4 carriers had significantly lower FA in forceps major and higher MD in the cortico-spinal tract. Allowing the white matter microstructure indicators in these tracts to mediate the association between APOE and PS resulted in a markedly attenuated association between these variables. Bootstrapping statistics in the subsample with DTI data (n = 89) indicated that FA in forceps major significantly mediated the association between APOE and PS (indirect effect: -0.070, 95% bias corrected CIs -0.197 to -0.004). Conclusion Lower white matter integrity may represent one of several mechanisms through which APOE affects PS performance in elderly persons free of dementia and preclinical dementia.
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| 55. |
- Le Guen, Yann, et al.
(författare)
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Multiancestry analysis of the HLA locus in Alzheimer's and Parkinson's diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes.
- 2023
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 1091-6490 .- 0027-8424. ; 120:36
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Tidskriftsartikel (refereegranskat)abstract
- Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson's disease (PD) and Alzheimer's disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues.
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| 56. |
- Lemoine, Laetitia, et al.
(författare)
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Amyloid, tau, and astrocyte pathology in autosomal-dominant Alzheimer's disease variants : A beta PParc and PSEN1DE9
- 2021
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Ingår i: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 26:10, s. 5609-5619
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Tidskriftsartikel (refereegranskat)abstract
- Autosomal-dominant Alzheimer's disease (ADAD) may be associated with atypical amyloid beta deposits in the brain. In vivo amyloid imaging using(11)C-Pittsburgh compound B (PiB) tracer has shown differences in binding between brains from ADAD and sporadic Alzheimer's disease (sAD) patients. To gain further insight into the various pathological characteristics of these genetic variants, we performed large frozen hemisphere autoradiography and brain homogenate binding assays with(3)H-PiB,H-3-MK6240-H-3-THK5117, and(3)H-deprenyl for detection of amyloid fibrils, tau depositions, and activated astrocytes, respectively, in twoA beta PParcmutation carriers, onePSEN1 Delta E9mutation carrier, and three sAD cases. The results were compared with Abeta 40, Abeta 42, AT8, and GFAP immunostaining, respectively, as well as with Congo red and Bielschowsky. PiB showed a very low binding inA beta PParc. A high binding was observed inPSEN1 Delta E9and in sAD tissues but with different binding patterns. Comparable(3)H-THK5117 and(3)H-deprenyl brain homogenate binding was observed forA beta PParc,PSEN1 Delta E9, and sAD, respectively. Some differences were observed between(3)H-MK6240 and(3)H-THK5117 in ADAD. A positive correlation between(3)H-deprenyl and(3)H-THK5117 binding was observed inA beta PParc, while no such correlation was found inPSEN1 Delta E9and sAD. Our study demonstrates differences in the properties of the amyloid plaques between two genetic variants of AD and sAD. Despite the lack of measurable amyloid fibrils by PiB in theA beta PParccases, high regional tau and astrocyte binding was observed. The lack of correlation between(3)H-deprenyl and(3)H-THK5117 binding inPSEN1 Delta E9and sAD in contrast of the positive correlation observed in theA beta PParccases suggest differences in the pathological cascade between variants of AD that warrant further exploration in vivo.
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| 57. |
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| 58. |
- Li, Xiaozhen, et al.
(författare)
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The Effects of Gene Mutations on Default Mode Network in Familial Alzheimer’s Disease
- 2017
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 56:1, s. 327-334
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Tidskriftsartikel (refereegranskat)abstract
- Familial Alzheimer’s disease (FAD) mutations have very high penetrance but age at onset and rate of disease progression differ. Neuroimaging and cerebrospinal fluid (CSF) examinations in mutation carriers (MCs) may provide an opportunity to identify early biomarkers that can be used to track disease progression from presymptomatic to the dementia stages of disease. The default mode network (DMN) is a resting state neuronal network composed of regions known to associate with amyloid deposition in AD. We hypothesized that functional connectivity in the DMN might change at pre-clinical stages in FAD MCs and correlate with changes in CSF biomarkers as a consequence of AD brain pathology. To test the hypothesis, we compared the functional connectivity in DMN between pre-MCs/MCs and non-carriers (NCs). No significant differences between pre-MCs and NCs were observed. When comparing all MCs with NCs, significant decreased functional connectivity in the right inferior parietal lobule, right precuneus, and left posterior cingulate cortex were found. We also found statistically significant correlations between CSF amyloid-β 42 and tau protein levels and average Z-score, a resting-state functional MRI measurement reflecting the degree of the correlation between a given voxel’s time courses and the time courses corresponding to DMN, from the region with statistical difference. The observed disruption of DMN and pathological levels of AD CSF-biomarkers in FAD MCs are similar to the changes described in sporadic AD, which give further support that amyloid and tau pathology impairs neuronal and synaptic function.
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| 59. |
- Lilja Andersson, Petra, et al.
(författare)
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Ethical aspects of a predictive test for Huntington’s Disease : a long term perspective
- 2016
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Ingår i: Nursing Ethics. - 0969-7330 .- 1477-0989. ; 23:5, s. 565-575
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Tidskriftsartikel (refereegranskat)abstract
- Background: A predictive genetic test for Huntington’s disease can be used before any symptoms are apparent, but there is only sparse knowledge about the long-term consequences of a positive test result. Such knowledge is important in order to gain a deeper understanding of families’ experiences.Objectives: The aim of the study was to describe a young couple’s long-term experiences and the consequences of a predictive test for Huntington’s disease.Research design: A descriptive case study design was used with a longitudinal narrative life history approach.Participants and research context: The study was based on 18 interviews with a young couple, covering a period of 2.5 years; starting 6 months after the disclosure of the test results showing the woman to be a carrier of the gene causing Huntington’s disease.Ethical considerations: Even though the study was extremely sensitive, where potential harm constantly had to be balanced against the benefits, the couple had a strong wish to contribute to increased knowledge about people in their situation. The study was approved by the ethics committee.Findings: The results show that the long-term consequences were devastating for the family. This 3-year period was characterized by anxiety, repeated suicide attempts, financial difficulties and eventually divorce.Discussion: By offering a predictive test, the healthcare system has an ethical and moral responsibility. Once the test result is disclosed, the individual and the family cannot live without the knowledge it brings. Support is needed in a long-term perspective and should involve counselling concerning the families’ everyday life involving important decision-making, reorientation towards a new outlook of the future and the meaning of life.Conclusion: As health professionals, our ethical and moral responsibility thus embraces not only the phase in direct connection to the actual genetic test but also a commitment to provide support to help the family deal with the long-term consequences of the test.
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| 60. |
- Lilja Andersson, Petra, et al.
(författare)
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Ethical aspects of a predictive test for Huntington's Disease: A long term perspective.
- 2016
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Ingår i: Nursing Ethics. - : SAGE Publications. - 1477-0989 .- 0969-7330. ; , s. 565-575
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Tidskriftsartikel (refereegranskat)abstract
- A predictive genetic test for Huntington's disease can be used before any symptoms are apparent, but there is only sparse knowledge about the long-term consequences of a positive test result. Such knowledge is important in order to gain a deeper understanding of families' experiences.
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