| 1. |
- Alafuzoff, Irina, et al.
(författare)
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Ageing-Related Neurodegeneration and Cognitive Decline
- 2024
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 25:7
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Tidskriftsartikel (refereegranskat)abstract
- Neuropathological assessment was conducted on 1630 subjects, representing 5% of all the deceased that had been sent to the morgue of Uppsala University Hospital during a 15-year-long period. Among the 1630 subjects, 1610 were ≥ 41 years of age (range 41 to 102 years). Overall, hyperphosphorylated (HP) τ was observed in the brains of 98% of the 1610 subjects, and amyloid β-protein (Aβ) in the brains of 64%. The most common alteration observed was Alzheimer disease neuropathologic change (ADNC) (56%), followed by primary age-related tauopathy (PART) in 26% of the subjects. In 16% of the subjects, HPτ was limited to the locus coeruleus. In 14 subjects (<1%), no altered proteins were observed. In 3 subjects, only Aβ was observed, and in 17, HPτ was observed in a distribution other than that seen in ADNC/PART. The transactive DNA-binding protein 43 (TDP43) associated with limbic-predominant age-related TDP encephalopathy (LATE) was observed in 565 (35%) subjects and α-synuclein (αS) pathology, i.e., Lewy body disease (LBD) or multi system atrophy (MSA) was observed in the brains of 21% of the subjects. A total of 39% of subjects with ADNC, 59% of subjects with PART, and 81% of subjects with HPτ limited to the locus coeruleus lacked concomitant pathologies, i.e., LATE-NC or LBD-NC. Of the 293 (18% of the 1610 subjects) subjects with dementia, 81% exhibited a high or intermediate level of ADNC. In 84% of all individuals with dementia, various degrees of concomitant alterations were observed; i.e., MIXED-NC was a common cause of dementia. A high or intermediate level of PART was observed in 10 subjects with dementia (3%), i.e., tangle-predominant dementia. No subjects exhibited only vascular NC (VNC), but in 17 subjects, severe VNC might have contributed to cognitive decline. Age-related tau astrogliopathy (ARTAG) was observed in 37% of the 1610 subjects and in 53% of those with dementia.
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| 2. |
- Alafuzoff, Irina, et al.
(författare)
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Mixed Brain Pathology Is the Most Common Cause of Cognitive Impairment in the Elderly
- 2020
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Ingår i: Journal of Alzheimer's Disease. - : IOS PRESS. - 1387-2877 .- 1875-8908. ; 78:1, s. 453-465
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Tidskriftsartikel (refereegranskat)abstract
- Background: Systemic diseases, diabetes mellitus (DM), and cardiovascular disease (CaVD) have been suggested being risk factors for cognitive impairment (CI) and/or influence Alzheimer's disease neuropathologic change (ADNC).Objective: The purpose was to assess the type and the extent of neuropathological alterations in the brain and to assess whether brain pathology was associated with CaVD or DM related alterations in peripheral organs, i.e., vessels, heart, and kidney.Methods: 119 subjects, 15% with DM and 24% with CI, age range 80 to 89 years, were chosen and neuropathological alterations were assessed applying immunohistochemistry.Results: Hyperphosphorylated tau (HP tau) was seen in 99%, amyloid-beta (A beta) in 71%, transactive DNA binding protein 43 (TDP43) in 62%, and alpha-synuclein (alpha S) in 21% of the subjects. Primary age related tauopathy was diagnosed in 29% (more common in females), limbic predominant age-related TDP encephalopathy in 4% (14% of subjects with CI), and dementia with Lewy bodies in 3% (14% of subjects with CI) of the subjects. High/intermediate level of ADNC was seen in 47% and the extent of HPt increased with age. The extent of ADNC was not associated with the extent of pathology observed in peripheral organs, i.e., DM or CaVD. Contrary, brain alterations such as pTDP43 and cerebrovascular lesions (CeVL) were influenced by DM, and CeVL correlated significantly with the extent of vessel pathology.Conclusion: In most (66%) subjects with CI, the cause of impairment was "mixed pathology", i.e., ADNC combined with TDP43, alpha S, or vascular brain lesions. Furthermore, our results suggest that systemic diseases, DMand CaVD, are risk factors for CI but not related to ADNC.
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| 3. |
- Borota, Ljubisa, et al.
(författare)
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Complete functional recovery in a child after endovascular treatment of basilar artery occlusion caused by spontaneous dissection : a case report
- 2022
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Ingår i: Child's Nervous System. - : Springer Nature. - 0256-7040 .- 1433-0350. ; 38:8, s. 1605-1612
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Tidskriftsartikel (refereegranskat)abstract
- Stroke caused by dissection of arteries of the vertebrobasilar system in children is still poorly investigated in terms of etiology, means of treatment, course of disease, and prognosis. The aim of this report was to describe the unusual course of a spontaneous dissection of the basilar artery (BA) in a child treated with endovascular techniques and to point out that the plasticity of the brain stem can fully compensate for structural damage caused by stroke. We report the case of a 15-year-old boy who suffered a wake-up stroke with BA occlusion caused by spontaneous dissection. A blood clot was aspirated from the false lumen and the true lumen re-opened, but the patient deteriorated a few hours later, and repeated angiography revealed that the intimal flap was detached, occluding the BA again. The lumen of BA was then reconstructed by a stent. Despite a large pons infarction, the patient was completely recovered 11 months after the onset. The case was analyzed with angiograms and magnetic resonance imaging, macroscopic and microscopic pathological analysis, computed tomographic angiography, magnetic resonance-based angiography, and diffusion tensor imaging. This case illustrates that applied endovascular techniques and intensive care measures can alter the course of potentially fatal brain stem infarction. Our multimodal analysis gives new insight into the anatomical basis for the plasticity mechanism of the brain stem.
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| 4. |
- Ehrstedt, Christoffer, et al.
(författare)
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Clinical characteristics and late effects in CNS tumours of childhood : Do not forget long term follow-up of the low grade tumours
- 2016
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Ingår i: European journal of paediatric neurology. - : Elsevier BV. - 1090-3798 .- 1532-2130. ; 20:4, s. 580-587
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate clinical characteristics and late effects of CNS tumours in childhood with a special focus on low-grade tumours, especially low-grade astrocytoma and glib neuronal tumours. Methods: A retrospective population based study was performed at Uppsala University Children's Hospital, a tertiary referral centre for children with CNS tumours. Patients were identified from the National Brain Tumour Registry and the National Epilepsy Surgery Registry. Hospital medical records were analysed for patients with a follow up of >= 5 years after diagnosis. A re-evaluation of the neuro-pathological diagnosis was performed. Results: A total of 193 patients (age 0-17.99 years) during a twelve-year period (1995-2006) were included; 149 survived >= 5 years. Three larger subgroups could be identified: astrocytic, embryonal and glioneuronal tumours. A supratentorial location was found in 52%. Medical late effects were mainly neurological and endocrinological, affecting 81% and 26% of surviving patients. Cognitive late effects were a frequent finding in the whole group but also in low-grade astrocytoma and glioneuronal tumours (53% and 67%). Thirty per cent had some kind of pedagogic support in school. Conclusion: Late effects are common in long-term survivors of CNS tumours in childhood. Low-grade astrocytoma and glioneuronal tumours are no exception, and the findings support the need for long-term follow up.
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| 5. |
- Elobeid, Adila, et al.
(författare)
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Altered proteins in the aging brain
- 2016
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Ingår i: Journal of Neuropathology and Experimental Neurology. - : Oxford University Press. - 0022-3069 .- 1554-6578. ; 75:4, s. 316-325
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Tidskriftsartikel (refereegranskat)abstract
- We assessed the prevalence of common altered brain proteins in 296 cognitively unimpaired subjects ranging from age 50 to 102 years. The incidence and the stage of hyperphosphorylated-tau (HP tau), beta-amyloid, alpha-synuclein (alpha S), and transactive response DNA (TDP) binding protein 43 (TDP43)-immunoreactivity (-IR) increased with age. HP tau-IR was observed in 98% of the subjects; the locus coeruleus was solely affected in 46%, and 79% of the subjects were in Braak stages a to II. beta-Amyloid was seen in 47% of subjects and the Thal phase correlated with the HP tau Braak stage and age. Intermediate Alzheimer disease-related pathology (ADRP) was seen in 12%; 52% of the subjects with HP tau-IR fulfilled criteria for definite primary age-related tauopathy (PART). The incidence of concomitant pathology (alpha S, TDP43) did not differ between those with PART and those with ADRP but the former were younger. TDP43-IR was observed in 36%; the most frequently affected region was the medulla; alpha S-IR was observed in 19% of subjects. In 41% of the subjects from 80 to 89 years at death, 3 altered proteins were seen in the brain. Thus, altered proteins are common in the brains of cognitively unimpaired aged subjects; this should be considered while developing diagnostic biomarkers, particularly for identifying subjects at early stages of neurodegenerative diseases.
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| 6. |
- Eltom, Khalid, et al.
(författare)
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Astrocytic accumulation of tau fibrils isolated from Alzheimer’s disease brains induces inflammation, cell-to-cell propagation and neuronal impairment
- 2024
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Ingår i: Acta neuropathologica communications. - : BioMed Central (BMC). - 2051-5960. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating evidence highlights the involvement of astrocytes in Alzheimer’s disease (AD) progression. We have previously demonstrated that human iPSC-derived astrocytes ingest and modify synthetic tau fibrils in a way that enhances their seeding efficiency. However, synthetic tau fibrils differ significantly from in vivo formed fibrils. To mimic the situation in the brain, we here analyzed astrocytes’ processing of human brain-derived tau fibrils and its consequences for cellular physiology. Tau fibrils were extracted from both AD and control brains, aiming to examine any potential differences in astrocyte response depending on the origin of fibrils. Our results show that human astrocytes internalize, but fail to degrade, both AD and control tau fibrils. Instead, pathogenic, seeding capable tau proteoforms are spread to surrounding cells via tunneling nanotubes and exocytosis. Notably, accumulation of AD tau fibrils induces a stronger reactive state in astrocytes, compared to control fibrils, evident by the augmented expression of vimentin and GFAP, as well as by an increased secretion of the pro-inflammatory cytokines IL-8 and MCP-1. Moreover, conditioned media from astrocytes with AD tau fibril deposits induce synapse and metabolic impairment in human iPSC-derived neurons. Taken together, our data suggest that the accumulation of brain-derived AD tau fibrils induces a more robust inflammatory and neurotoxic phenotype in human astrocytes, accentuating the nature of tau fibrils as an important contributing factor to inflammation and neurodegeneration in AD.
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| 7. |
- Falk Delgado, Anna, et al.
(författare)
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Diffusion kurtosis imaging of gliomas grades II and III : a study of perilesional tumor infiltration, tumor grades and subtypes at clinical presentation
- 2017
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Ingår i: Radiology and Oncology. - : Walter de Gruyter GmbH. - 1318-2099 .- 1581-3207. ; 51:2, s. 121-129
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Tidskriftsartikel (refereegranskat)abstract
- Background. Diffusion kurtosis imaging (DKI) allows for assessment of diffusion influenced by microcellular structures. We analyzed DKI in suspected low-grade gliomas prior to histopathological diagnosis. The aim was to investigate if diffusion parameters in the perilesional normal-appearing white matter (NAWM) differed from contralesional white matter, and to investigate differences between glioma malignancy grades II and III and glioma subtypes (astrocytomas and oligodendrogliomas).Patients and methods. Forty-eight patients with suspected low-grade glioma were prospectively recruited to this institutional review board-approved study and investigated with preoperative DKI at 3T after written informed consent. Patients with histologically proven glioma grades II or III were further analyzed (n=35). Regions of interest (ROIs) were delineated on T2FLAIR images and co-registered to diffusion MRI parameter maps. Mean DKI data were compared between perilesional and contralesional NAWM (student's t-test for dependent samples, Wilcoxon matched pairs test). Histogram DKI data were compared between glioma types and glioma grades (multiple comparisons of mean ranks for all groups). The discriminating potential for DKI in assessing glioma type and grade was assessed with receiver operating characteristics (ROC) curves.Results. There were significant differences in all mean DKI variables between perilesional and contralesional NAWM (p=< 0.000), except for axial kurtosis (p=0.099). Forty-four histogram variables differed significantly between glioma grades II (n=23) and III (n=12) (p=0.003-0.048) and 10 variables differed significantly between ACs (n=18) and ODs (n=17) (p=0.011-0.050). ROC curves of the best discriminating variables had an area under the curve (AUC) of 0.657-0.815.Conclusions. Mean DKI variables in perilesional NAWM differ significantly from contralesional NAWM, suggesting altered microstructure by tumor infiltration not depicted on morphological MRI. Histogram analysis of DKI data identifies differences between glioma grades and subtypes.
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| 10. |
- Hellström, Jussi, et al.
(författare)
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Evaluation of the INTERPRET decision-support system : can it improve the diagnostic value of magnetic resonance spectroscopy of the brain?
- 2019
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 61:1, s. 43-53
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: We evaluated in a clinical setting the INTERPRET decision-support system (DSS), a software generated to aid in MRS analysis to achieve a specific diagnosis for brain lesions.Methods: The material consisted of 100 examinations of focal intracranial lesions with confirmed diagnoses. MRS was obtained at 1.5 T using TE 20–30 ms. Data were processed with the LCModel for conventional analysis. The INTERPRET DSS 3.1. was used to obtain specific diagnoses. MRI and MRS were reviewed by one interpreter. DSS analysis was made by another interpreter, in 80 cases by two interpreters. The diagnoses were compared with the definitive diagnoses. For comparisons between DSS, conventional MRS analysis, and MRI, the diagnoses were categorised: high-grade tumour, low-grade tumour, non-neoplastic lesion.Results: Interobserver agreement in choosing the diagnosis from the INTERPRET database was 75%. The diagnosis was correct in 38/100 cases, incorrect in 57 cases. No good match was found in 5/100 cases. The diagnostic category was correct with DSS/conventional MRS/MRI in 67/58/52 cases, indeterminate in 5/8/20 cases, incorrect in 28/34/28 cases. Results with DSS were not significantly better than with conventional MRS analysis. All definitive diagnoses did not exist in the INTERPRET database. In the 61 adult patients with the diagnosis included in the database, DSS/conventional MRS/MRI yielded a correct diagnosis category in 48/32/29 cases (DSS vs conventional MRS: p = 0.002, DSS vs MRI: p = 0.0004).Conclusion: Use of the INTERPRET DSS did not improve MRS categorisation of the lesions in the unselected clinical cases. In adult patients with lesions existing in the INTERPRET database, DSS improved the results, which indicates the potential of this software with an extended database.
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