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| 2. |
- Haglund, Mattias, et al.
(författare)
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Cerebral amyloid angiopathy and cortical microinfarcts as putative substrates of vascular dementia.
- 2006
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Ingår i: International Journal of Geriatric Psychiatry. - : Wiley. - 1099-1166 .- 0885-6230. ; 21:7, s. 681-687
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose Vascular dementia (VaD) has occasionally been associated with cerebral amyloid angiopathy (CAA), but the prevalence and significance of this counterintuitive relationship are poorly known. Therefore, we investigated the presence and characteristics of CAA in brains of VaD cases. Methods We examined temporal and parietal regions of the cerebral cortex of 26 consecutive VaD cases from the Lund Longitudinal Dementia Study. We carried out immunohistochemistry and routine stainings, determined Apolipoprotein E (ApoE) genotypes, and obtained clinical characteristics on the studied group for retrospective analysis. Results CAA was marked in eight out of 26 cases, and correlated strongly with the presence of cortical microinfarcts, both in the temporal lobe and in the parietal lobe. Based on comparisons with eight age-matched VaD cases without CAA, the clinical records suggested that VaD cases with CAA as a group exhibited less pronounced neurological symptoms. A clear contribution of the ApoE genotype could not be identified. Conclusions Based on a combination of the clinical and pathological data, we suggest that microinfarcts in the cerebral cortex associated with severe CAA may be the primary pathological substrate in a significant proportion of VaD cases. Future studies should be undertaken to confirm or dismiss the hypothesis that these cases exhibit a different symptom profile than VaD cases without CAA. Copyright (c) 2006 John Wiley & Sons, Ltd.
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| 3. |
- Haglund, Mattias, et al.
(författare)
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Differential deposition of amyloid beta peptides in cerebral amyloid angiopathy associated with Alzheimer's disease and vascular dementia.
- 2006
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 1432-0533 .- 0001-6322. ; 111:5, s. 430-435
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid angiopathy (CAA) caused by deposition of amyloid beta (A beta) peptides in the cerebrovasculature, involves degeneration of normal vascular components and increases the risk of infarction and cerebral hemorrhage. Accumulating evidence suggests that sporadic CAA is also a significant contributor to cognitive decline and dementia in the elderly. However, the mechanisms by which CAA arises are poorly understood. While neuronal sources of A beta peptides are sufficient to cause CAA in transgenic mice overexpressing the amyloid precursor protein, there is reason to believe that in aging man, vascular disease modulates the disease process. To better understand CAA mechanisms in dementia, we assessed the frontal cortex of 62 consecutive cases of Alzheimer's disease (AD), vascular dementia (VaD), and mixed dementia (MD) using immunohistochemistry with antibodies to A beta, smooth muscle actin and the carboxyl-terminal peptides to detect A beta(40) and A beta(42). While vascular A beta deposition was invariably associated with smooth muscle degeneration as indicated by absence of smooth muscle cell actin reactivity, VaD/MD cases exhibited markedly more vascular A beta(42) deposits and smooth muscle actin loss compared to AD cases with similar degrees of CAA and A beta(40) deposition. This suggests that distinct mechanisms are responsible for the differential deposition of A beta in CAA associated with AD and that associated with ischemic/cerebrovascular disease. It is plausible that experimental studies on the effects of cerebrovascular disease on A beta production and elimination will yield important clues on the pathogenesis of CAA.
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| 4. |
- Haglund, Mattias, et al.
(författare)
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Locus ceruleus degeneration is ubiquitous in Alzheimer's disease: possible implications for diagnosis and treatment.
- 2006
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Ingår i: Neuropathology. - : Wiley. - 0919-6544 .- 1440-1789. ; 26:6, s. 528-532
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Tidskriftsartikel (refereegranskat)abstract
- Degeneration of the locus ceruleus (LC) and decreased cortical levels of norepinephrine are common findings in Alzheimer's disease (AD), but their significance is unknown. Because the noradrenergic system is accessible to pharmacological intervention, the role of LC degeneration and noradrenergic dysfunction in the pathogenesis and clinical manifestations of AD needs clarification. Hypothetically, loss of noradrenergic innervation could cause microvascular dysfunction and manifest as ischemia. The objectives of this study were to develop a scale for assessment of LC degeneration and to determine whether degeneration of the LC correlates quantitatively with either duration of clinical dementia, overall severity of AD pathology or with measures of ischemic non-focal white matter disease (WMD) in AD. This report is a pathological follow-up of a clinical longitudinal dementia study of 66 consecutive cases of AD without admixture of vascular dementia (VaD) from the Lund Longitudinal Dementia Study, neuropathologically diagnosed between 1990 and 1999. Ten cases of VaD were included for comparative purposes. No correlation between degree of LC degeneration and duration of dementia, AD or WMD severity was found. LC degeneration was significantly more severe in the AD group than in the VaD group. Even though LC degeneration was not associated with WMD or the severity of AD pathology in this AD material, we suggest that clinical studies on the consequences of noradrenergic dysfunction are warranted. Treatment augmenting noradrenergic signaling is available and safe. The marked difference in the level of LC degeneration between AD and VaD cases suggests that LC degeneration could be used as a diagnostic marker of AD.
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| 5. |
- Malmborg, Carin, et al.
(författare)
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Mapping the intracellular fraction of water by varying the gradient pulse length in q-space diffusion MRI
- 2006
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Ingår i: Journal of Magnetic Resonance. - : Elsevier BV. - 1096-0856 .- 1090-7807. ; 180:2, s. 280-285
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Tidskriftsartikel (refereegranskat)abstract
- Finite gradient pulse lengths are traditionally considered a nuisance in q-space diffusion NMR and MRI, since the simple Fourier relation between the acquired signal and the displacement probability is invalidated. Increasing the value of the pulse length leads to an apparently smaller value of the estimated compartment size. We propose that q-space data at different gradient pulse lengths, but with the same effective diffusion time, can be used to identify and quantify components with free or restricted diffusion from multi-exponential echo decay curves obtained on cellular systems. The method is demonstrated with experiments on excised human brain white matter and a series of model systems with well-defined free, restricted, and combined free and restricted diffusion behavior. Time-resolved diffusion MRI experiments are used to map the spatial distribution of the intracellular fraction in a yeast cell suspension during sedimentation, and observe the disappearance of this fraction after a heat treatment. (c) 2006 Elsevier Inc. All rights reserved.
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| 6. |
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| 7. |
- Persson, Annette, et al.
(författare)
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Cell type- and region- dependent coxsackie adenovirus receptor expression in the central nervous system.
- 2006
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Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 1573-7373 .- 0167-594X. ; 78:1, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Model systems have shown that adenoviral vector mediated transient gene expression can potentially be applied for the treatment of brain tumours, neurodegenerative diseases and brain injuries. Most studies utilized adenovirus serotype 5 (Ad5) based vectors, which as adhesion molecules require the coxsackie adenovirus receptor (CAR) as a critical determinant for cellular infection. In this report, we have systematically characterized CAR expression in the adult human central nervous system (CNS) by using immunohistochemistry. A total of 85 specimens from various CNS regions were investigated for CAR expression in a cell type-dependent context. The most marked staining positivity was found in the choroid plexus and the pituitary gland. The neocortex had scattered positive neurons, while the white matter was mainly negative. We need to consider the possible adverse effects and the possible damage caused by adenoviral gene therapy if the virus-vector also binds to normal brain cells.
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| 9. |
- Sjöbeck, Martin, et al.
(författare)
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White matter mapping in Alzheimer's disease: A neuropathological study.
- 2006
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 27:5, s. 673-680
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Tidskriftsartikel (refereegranskat)abstract
- White matter disease (WMD) with pervasive non-focal subtotal tissue loss is frequently seen in Alzheimer's disease (AD) upon neuropatholooical examination. Although WMD has varying effects on AD symptoms, accurate clinical detection is difficult due partly to scarcity of correlative structural imaging and histopathological studies. Neuropathological Studies of WMD severity and distribution have been conducted earlier using semi-quantitative methods. A technique for quantifying WMD objectively in large white matter areas, based on optical density (OD) measurements oil images of scanned whole-brain sections, was developed and was validated using conventional microscopic assessment. Altogether, 16 AD cases with concomitant WMD (AD-WMD) and 9 cases of AD without WMD (AD-only) were analysed. The OD values correlated significantly with the neuropathological severity of WMD and were significantly lower in AD-WMD than ill AD-only in frontal, frontoparietal, temporal and parietal white matter but not ill the occipital white matter, the frontal OD difference being greatest. Useful baseline information oil WMD distribution in AD to relate to in vivo imaging results was obtained. (c) 2005 Published by Elsevier Inc.
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| 10. |
- Smith, Ruben, et al.
(författare)
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Cholinergic neuronal defect without cell loss in Huntington's disease.
- 2006
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 15:21, s. 3119-3131
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Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG-repeat expansion in the huntingtin (IT15) gene. The striatum is one of the regions most affected by neurodegeneration, resulting in the loss of the medium-sized spiny neurons. Traditionally, the large cholinergic striatal interneurons are believed to be spared. Recent studies demonstrate that neuronal dysfunction without cell death also plays an important role in early and mid-stages of the disease. Here, we report that cholinergic transmission is affected in a HD transgenic mouse model (R6/1) and in tissues from HD patients. Stereological analysis shows no loss of cholinergic neurons in the striatum or septum in R6/1 mice. In contrast, the levels of mRNA and protein for vesicular acetylcholine transporter (VAChT) and choline acetyltransferase (ChAT) are decreased in the striatum and cortex, and acetylcholine esterase activity is lowered in the striatum of R6/1 mice already at young ages. Accordingly, VAChT is also reduced in striatal tissue from patients with HD. The decrease of VAChT in the patient samples studied is restricted to the striatum and does not occur in the hippocampus or the spinal cord. The expression and localization of REST/NRSF, a transcriptional regulator for the VAChT and ChAT genes, are not altered in cholinergic neurons. We show that the R6/1 mice exhibit severe deficits in learning and reference memory. Taken together, our data show that the cholinergic system is dysfunctional in R6/1 and HD patients. Consequently, they provide a rationale for testing of pro-cholinergic drugs in this disease.
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