| 1. |
- Lind, J., et al.
(author)
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Parietal cortex activation predicts longitudinal memory decline in APOE ε4 carriers.
- 2006
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In: NeuroReport. ; :17, s. 1683-1686
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Journal article (pop. science, debate, etc.)abstract
- Apolipoprotein E-epsilon 4 is the main known genetic risk factor for Alzheimer’s disease. Functional abnormalities in the parietal cortex have been reported for Alzheimer’s disease patients and also for those at risk. Hence, a critical question is whether measurements of parietal cortex integrity may predict negative outcome among at- risk persons. We studied nondemented apolipo-protein E-epsilon 4 carriers and found a significant relationship between parietal blood-oxygen-level-dependent functional magnetic resonance imaging response during a word categorization task and subsequent episodic memory performance. Thus, the results show that parietal cortex alterations predict memory decline in nondemented apolipoprotein E-epsilon 4 carriers, and hence likely progression to Alzheimer’s disease.
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| 2. |
- Persson, J, et al.
(author)
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Altered brain white-matter integrity in non-demented carriers of the APOE ε4 allele: A risk for Alzheimer’s disease.
- 2006
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In: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 66:7, s. 1029-1033
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Journal article (peer-reviewed)abstract
- Previous research has shown that polymorphisms of the apolipoprotein E (APOE) represent genetic risk factors for dementia and for cognitive impairment in the elderly. The neural mechanisms by which these genetic variations influence behavioral performance or clinical severity are not well understood. We used diffusion tensor imaging to investigate ultrastructural properties in brain white-matter to detect pathological processes that modify tissue integrity. Sixty participants were included in the study of which 30 were homozygous for the APOE ε3 allele, 10 were homozygous for the APOE ε4 allele, and 20 had the APOE ε34 allele combination. All individuals were non-demented, and the groups were matched on demographic variables and cognitive performance. The results showed a decline in fractional anisotropy, a marker for white-matter integrity, in the posterior corpus callosum of ε4 carriers compared to non-carriers. Additional sites of altered white-matter integrity included the medial temporal lobe. Conclusions: Although the mechanism underlying vulnerability of white matter tracts in APOE ε4 carriers is still unknown, our findings suggest that increased genetic risk for developing AD is associated with changes in microscopic white-matter integrity well before the onset of dementia.
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| 3. |
- Rademakers, R, et al.
(author)
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Association of cyclin-dependent kinase 5 and neuronal activators p35 and p39 complex in early-onset Alzheimer's disease.
- 2005
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In: Neurobiology of Aging. - New York : Elsevier BV. - 0197-4580 .- 1558-1497. ; 26:8, s. 1145-1151
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Journal article (peer-reviewed)abstract
- Malfunctioning of cyclin-dependent kinase 5 (CDK5) through aberrant proteolytic cleavage of its neuronal activators p35 and p39 is involved in neurodegeneration in Alzheimer's disease (AD) and other neurodegenerative brain diseases. By extensive genetic analysis of the genes encoding CDK5 (CDK5), p35 (CDK5R1) and p39 (CDK5R2), we excluded causal mutations in 70 familial early-onset AD patients. We performed an association study with five informative SNPs in CDK5 in two independent samples of early-onset AD patients and matched control individuals from The Netherlands and northern Sweden. Association was observed with g.149800G>C in intron 5 of CDK5, and a two times increased risk was observed in both patient samples for carriers of the C-allele. Our data are indicative for a role of the CDK5 molecular complex in the genetic etiology of early-onset AD, and suggest that a yet unknown functional variant in CDK5 or in a nearby gene might lead to increased susceptibility for early-onset AD.
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| 4. |
- Sundström, Anna, 1969-, et al.
(author)
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Increased risk of dementia following mild head injury for carriers but not for non-carriers of the APOE ε4 allele
- 2007
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In: International psychogeriatrics. - New York : Springer. - 1041-6102 .- 1741-203X. ; 19:1, s. 159-165
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Journal article (peer-reviewed)abstract
- Background: The ε4 allele of apolipoprotein E (APOE) and head injury are risk factors for dementia diseases, and may act synergistically to further increase the risk. The aim of this study was to examine the association between mild head injury, APOE and dementia.Methods: Data were obtained from the Betula prospective population-based study of aging, memory, and health. The study included 543 participants in the age range 40–85 years, free of dementia at baseline, who were followed up within a 5-year interval. Dementia was classified using DSM-IV criteria. Information on previous head injury was obtained through screening of the participants' answers to health questionnaires at baseline and at follow-up.Results: Subjects with head injury but without APOE ε4 had no increased risk of dementia. Subjects with APOE ε4 had an increased risk and those with both APOE ε4 and head injury had the highest risk of dementia (odds ratio = 5.2).Conclusions: APOE ε4 constitutes a risk factor for dementia, mild injury in isolation does not increase the risk, but head injury in combination with the APOE ε4 leads to increased risk of dementia.
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