| 1. |
- Brunnström, Hans, et al.
(författare)
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Correlations of CSF tau and amyloid levels with Alzheimer pathology in neuropathologically verified dementia with Lewy bodies.
- 2013
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Ingår i: International Journal of Geriatric Psychiatry. - : Wiley. - 1099-1166 .- 0885-6230. ; 28:7, s. 738-744
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The presence of concomitant Alzheimer pathology has been linked to earlier death in cases with dementia with Lewy bodies (DLB). Recently, elevated cerebrospinal fluid (CSF) tau protein levels have been reported to be associated with shorter survival in clinically diagnosed DLB. Correlations between CSF biomarkers and neuropathological findings in DLB are missing. The aim of this study was to investigate correlations between CSF biomarker levels and histopathological findings, with a focus on concomitant Alzheimer pathology, in neuropathologically verified DLB cases. METHODS: The extent of neurofibrillary pathology (Braak stage), neuritic plaques (CERAD stage), Alzheimer pathology (PPAD9 stage) and cerebral amyloid angiopathy was assessed in 16 cases with DLB in whom total tau (T-tau), hyperphosphorylated tau and amyloid beta 1-42 (Aβ42) protein levels in CSF had been analyzed in vivo. Demographic and clinical data were collected. RESULTS: Both Braak and PPAD9 stages were inversely correlated with Aβ42 levels, whereas CERAD stage showed no significant correlations. Cerebral amyloid angiopathy correlated positively with T-tau and T-tau/Aβ42 ratio, and inversely with Aβ42 levels, but the group showed a very heterogeneous extent of cerebral amyloid angiopathy. CONCLUSIONS: The burden of concomitant Alzheimer pathology correlates with CSF Aβ42 but not with T-tau levels in cases with neuropathologically defined DLB. Copyright © 2012 John Wiley & Sons, Ltd.
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| 2. |
- Londos, Elisabet, et al.
(författare)
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Extreme sleep pattern in Lewy body dementia : A hypothalamic matter?
- 2019
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Ingår i: BMJ Case Reports. - : BMJ. - 1757-790X. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Excessive sleep during the night and for >2 hours during the day is part of the fluctuating wakefulness criterion of dementia with Lewy bodies (DLB). The phenomenon â € sleep days' is not uncommon in nursing homes. Here, we describe a woman who, for months, slept for 3 days and nights in a row and thereafter was awake for 3 days and nights. Electroencephalogram (EEG) showed slow background activity and increased delta activity. No epileptiform activity was detected. Polysomnography showed a severely disturbed, markedly fragmented sleep pattern. On her death, neuropathology revealed degeneration and loss of neurons along with α-synuclein-containing Lewy body inclusions and neurites in the substantia nigra, locus coeruleus, hypothalamus, and neocortex, thus fulfilling the criteria of DLB, cortical type. We propose that the hypothalamic degeneration contributed significantly to the clinical profile in this case. We suggest that patients with sleep days should be investigated for other DLB signs.
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| 3. |
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| 4. |
- Adler, Aleksandra, 1983-
(författare)
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Cognitive load in dialogue interpreting : Experience and directionality
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation investigates the effect of experience and language direction on cognitive load in dialogue interpreting. The general objective of the study is to contribute to a better understanding of cognitive processes involved in dialogue interpreting. The present inquiry employs a multi- and mixed- method design and seeks to investigate disfluency measures as indicators of cognitive load in dialogue interpreting. Furthermore, the study aims to explore whether blink-based measures are sensitive to changes in cognitive load of dialogue interpreters. The present study is positioned within cognitive translation and interpreting studies (CTIS) and employs cognitive translatology as a framework, encompassing both cognitive and psycholinguistic approaches to translation and interpreting. Chen’s multidimensional theoretical construct of cognitive load in interpreting is explored in the study and remodeled to fit the context of dialogue interpreting and the assumptions of cognitive translatology. The data were collected from 17 dialogue interpreters during simulated interpreted encounters that recreated a situation commonly arising in a public service context in Sweden. The 10 inexperienced and 7 experienced interpreters all had Swedish as their working language, and the other working languages were French, Polish, and Spanish. Following the revised cognitive load model, the analyses of cognitive load focus on interpreter characteristics (interpreting experience) and on task and environmental characteristics (directionality). The results of analyses show that, in line with previous research, both interpreting experience and directionality modulate cognitive load of dialogue interpreters. Specifically, interpreting experience is demonstrated to attenuate cognitive load. In terms of directionality, interpreting into L2 is shown to be more cognitively demanding than interpreting into L1. Moreover, blink rate and blink rate variability (BRV) are explored as possible indicators of cognitive load. The analyses of blink measures suggest that no meaningful relationship can be found between blink measures and cognitive load.Finally, the complementary analyses of disfluency types in the utterances of the Polish interpreters (n=4) point to multifunctionality of disfluency in dialogue interpreting and to the multiple origins of cognitive load in interpreting dialogues. The analysis is performed from the perspective of the functional-cognitive view of disfluency proposed in the dissertation, whereby three disfluency context categories are identified and applied (cognitive-monitoring, cognitive-pragmatic, and cognitive-processing). Lexical access and rendition planning are identified as recurrent causes of cognitive load in dialogue interpreting. The study also makes theoretical and methodological contributions, primarily by revising the theoretical model of cognitive load in interpreting, which allows for operationalization of cognitive load with additional measures, in both experimental and naturalistic settings. Practical implications are a contribution to the understanding of the challenges interpreting into L2, and the impact of interpreters’ experience on interpreting. Overall, the study contributes to the emerging cognitive profile of dialogue interpreters.
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| 5. |
- Ahlenius, Henrik, et al.
(författare)
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Adaptor Protein LNK Is a Negative Regulator of Brain Neural Stem Cell Proliferation after Stroke.
- 2012
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Ingår i: The Journal of Neuroscience : the official journal of the Society for Neuroscience. - 1529-2401. ; 32:15, s. 5151-5164
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Tidskriftsartikel (refereegranskat)abstract
- Ischemic stroke causes transient increase of neural stem and progenitor cell (NSPC) proliferation in the subventricular zone (SVZ), and migration of newly formed neuroblasts toward the damaged area where they mature to striatal neurons. The molecular mechanisms regulating this plastic response, probably involved in structural reorganization and functional recovery, are poorly understood. The adaptor protein LNK suppresses hematopoietic stem cell self-renewal, but its presence and role in the brain are poorly understood. Here we demonstrate that LNK is expressed in NSPCs in the adult mouse and human SVZ. Lnk(-/-) mice exhibited increased NSPC proliferation after stroke, but not in intact brain or following status epilepticus. Deletion of Lnk caused increased NSPC proliferation while overexpression decreased mitotic activity of these cells in vitro. We found that Lnk expression after stroke increased in SVZ through the transcription factors STAT1/3. LNK attenuated insulin-like growth factor 1 signaling by inhibition of AKT phosphorylation, resulting in reduced NSPC proliferation. Our findings identify LNK as a stroke-specific, endogenous negative regulator of NSPC proliferation, and suggest that LNK signaling is a novel mechanism influencing plastic responses in postischemic brain.
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| 6. |
- Alafuzoff, Irina, et al.
(författare)
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The need to unify neuropathological assessments of vascular alterations in the ageing brain : Multicentre survey by the BrainNet Europe consortium
- 2012
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 47:11, s. 825-833
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Tidskriftsartikel (refereegranskat)abstract
- Here, we summarise the results after carrying out a large survey regarding the assessment of vascular alterations, both vessel changes and vascular lesions in an inter-laboratory setting. In total, 32 neuropathologists from 22 centres, most being members of BrainNet Europe (BNE), participated by filling out a questionnaire with emphasis on assessment of common vascular alterations seen in the brains of aged subjects. A certain level of harmonisation has been reached among BNE members regarding sectioning of the brain, harvesting of brain tissue for histology and staining used when compared to the survey carried out in 2006 by Pantoni and colleagues. The most significant variability was seen regarding the assessment of severity and of clinical significance of vascular alterations. Two strategies have recently been recommended regarding the assessment of vascular alterations in aged and demented subjects. The National Institute on Aging - Alzheimer's Association (NIA-AA) recommends the assessment of hippocampal sclerosis, vascular brain injury and microvascular lesions in 12 regions. Although this strategy will be easy to follow, the recommendations do not inform how the load of observed alterations should be assessed and when the observed lesions are of significance. Deramecourt and his colleagues recommend an assessment and semiquantitative grading of various pathologies in 4 brain regions. This strategy yielded a total score of 0 to 20 as an estimate of pathology load. It is, however, not clear which score is considered to be of clinical significance. Furthermore, in several BNE trials the semiquantitative assessment has yielded poor agreement rates; an observation that might negatively influence the strategy proposed by Deramecourt and his colleagues. In line with NIA-AA, a dichotomised approach of easily recognisable lesions in a standardised set of brain regions harvested for neuropathological assessment and applying reproducible sampling and staining strategies is recommended by BNE. However, a simple strategy regarding assessment of load of alteration is urgently needed to yield reproducible, and at the same time, comparable results between centres.
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| 7. |
- Allard, Per, et al.
(författare)
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Caudate nucleus dopamine D-2 receptors in vascular dementia
- 2002
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 14:1, s. 22-25
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Tidskriftsartikel (refereegranskat)abstract
- Caudate nucleus dopamine (DA) D-2 receptors were studied in patients with vascular dementia (VaD) and in a control group using [H-3]raclopride as a radioligand. There was no significant difference in the number of DA D-2 receptors in the VaD group as compared with controls. The binding affinity was significantly lower in the VaD group. When the VaD group was subdivided into subjects with or without neuroleptic treatment, there were no differences in the numbers of receptors as compared with controls, and the significant differences in binding affinity remained for both VaD subgroups. The present results are. discussed with reference to the previous finding of a reduced density of caudate nucleus DA uptake sites in the same VaD group and to results from studies on DA D-2 receptors in Alzheimer's disease and Parkinson's disease. Copyright (C) 2002 S. Karger AG, Basel.
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| 8. |
- Andersson, Elin Möller, et al.
(författare)
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Clinicopathological concordance in cognitive disease diagnostics
- 2020
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Ingår i: Clinical Neuropathology. - 0722-5091. ; 39:3, s. 99-104
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Tidskriftsartikel (refereegranskat)abstract
- Neurocognitive disorder encompasses many separate diagnoses, such as frontotemporal dementia (FTD), Alzheimer's disease (AD), Lewy body dementia (LBD), vascular dementia (VaD), and mixed dementia (MD). Because of the many variations between and within each subtype, it may be a challenge to clinically diagnose each condition. In a previous study on 176 dementia patients in a university hospital cohort between the years 1996 and 2006, a full diagnostic concordance of 49% was demonstrated between clinical diagnoses and pathological morphology [1]. The aims of this study were to do a follow-up on diagnostic concordance from the subsequent 10 years (2007 - 2016) and to compare the results with the previous study from 2009. In all cases of neuropathologically diagnosed dementia disorders (n = 324), the clinical records were searched for information on the clinical diagnosis of dementia, including on subtype. All individuals who had been diagnosed by a specialist were selected (n = 210). In this study, a full concordance between clinical diagnoses and neuropathological morphology was found in 61% of individuals, with marked variations between subgroups, including the lowest (31%) in the group of VaD. Vigilance in clinicopathological concordance is important for quality maintenance as well as the improvement of skills in diagnostic work. In light of the previous study, VaD one decade later remains elusive. The unmasking of this complicated and multifaceted disorder may be beneficial to the overall diagnostic accuracy in cognitive disease investigations.
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| 9. |
- Andin, Ulla, et al.
(författare)
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Alzheimer's disease (AD) with and without white matter pathology-clinical identification of concurrent cardiovascular disorders.
- 2007
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Ingår i: Archives of Gerontology and Geriatrics. - : Elsevier BV. - 1872-6976 .- 0167-4943. ; 44, s. 277-286
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Tidskriftsartikel (refereegranskat)abstract
- Clinical vascular features, either as manifest vascular disease or as cardiovascular risk factors were compared in AD with and without neuropathological white matter disease (WMD). The aim of the study was to investigate whether the presence of WMD and the severity of either AD pathology or WMD were associated with different cardiovascular profiles. A total of 44 AD cases were retrospectively studied. All the cases were neuropathologically diagnosed as AD with WMD (n = 22) and as AD without WMD (n = 22), respectively. The patients' medical records were studied with regard to their medical history and to somatic and neurological findings including arrhythmia, congestive heart failure, angina, myocardial infarctions, signs of TIA/stroke, diabetes mellitus, and blood pressure abnormalities, such as hypertension and orthostatic hypotension. In AD-WMD, hypertension, orthostatic hypotension as well as dizziness/unsteadiness were significantly more common than in AD without WMD. Cardiovascular symptoms were more frequent in AD-WMD than in the other group, though the difference did not reach statistical significance. Hypothetically, abnormal and unstable blood pressure levels underlie recurrent cerebral hypoperfusion, which may in turn leave room for the development of WMD. Furthermore, dizziness/unsteadiness may be a symptom reflecting the presence of WMD. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
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| 10. |
- Arcini, Caroline, et al.
(författare)
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Intracranial Atherosclerosis in Medieval Scandinavia
- 2023
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Ingår i: The Bioarchaeology of Cardiovascular Disease. - : Cambridge University Press. - 9781108648561 - 9781108480345 ; , s. 164-173
-
Bokkapitel (refereegranskat)abstract
- In past human populations, atherosclerosis has been identified in mummies from different regions of the world, and from a range of chronological periods (for extensive reviews see Chapters 3 and 4). This current study from Sweden aims to contribute to the limited evidence for atherosclerosis associated with human skeletal remains by presenting examples of atherosclerosis in another part of the body. We describe two well-preserved cemeteries in Åhus and Skänninge (1237-1536 CE) in present-day Sweden where several individuals with atherosclerosis of the internal carotid artery were discovered.
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| 11. |
- Arvidsson, Ida, et al.
(författare)
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Early terminal complement blockade and C6 deficiency are protective in enterohemorrhagic Escherichia coli-infected mice
- 2016
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 197:4, s. 1276-1286
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Tidskriftsartikel (refereegranskat)abstract
- Complement activation occurs during enterohemorrhagic Escherichia coli (EHEC) infection and may exacerbate renal manifestations. In this study, we show glomerular C5b-9 deposits in the renal biopsy of a child with EHEC-associated hemolytic uremic syndrome. The role of the terminal complement complex, and its blockade as a therapeutic modality, was investigated in a mouse model of E. coli O157:H7 infection. BALB/c mice were treated with monoclonal anti-C5 i.p. on day 3 or 6 after intragastric inoculation and monitored for clinical signs of disease and weight loss for 14 d. All infected untreated mice (15 of 15) or those treated with an irrelevant Ab (8 of 8) developed severe illness. In contrast, only few infected mice treated with anti-C5 on day 3 developed symptoms (three of eight, p < 0.01 compared with mice treated with the irrelevant Ab on day 3) whereas most mice treated with anti-C5 on day 6 developed symptoms (six of eight). C6-deficient C57BL/6 mice were also inoculated with E. coli O157:H7 and only 1 of 14 developed disease, whereas 10 of 16 wild-type mice developed weight loss and severe disease (p < 0.01). Complement activation via the terminal pathway is thus involved in the development of disease in murine EHEC infection. Early blockade of the terminal complement pathway, before the development of symptoms, was largely protective, whereas late blockade was not. Likewise, lack of C6, and thereby deficient terminal complement complex, was protective in murine E. coli O157:H7 infection.
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| 12. |
- Badian, Reza A., et al.
(författare)
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Comparison of novel wide-field in vivo corneal confocal microscopy with skin biopsy for assessing peripheral neuropathy in type 2 diabetes
- 2023
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 72:7, s. 908-917
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Tidskriftsartikel (refereegranskat)abstract
- Diabetic peripheral neuropathy (DPN) is a serious complication of diabetes, where skin biopsy assessing intraepi-dermal nerve fiber density (IENFD) plays an important diagnostic role. In vivo confocal microscopy (IVCM) of the corneal subbasal nerve plexus has been proposed as a noninvasive diagnostic modality for DPN. Direct compari-sons of skin biopsy and IVCM in controlled cohorts are lacking, as IVCM relies on subjective selection of images depicting only 0.2% of the nerve plexus. We compared these diagnostic modalities in a fixed-age cohort of 41 participants with type 2 diabetes and 36 healthy participants using machine algorithms to create wide-field image mosaics and quantify nerves in an area 37 times the size of prior studies to avoid human bias. In the same partici-pants, and at the same time point, no correlation between IENFD and corneal nerve density was found. Corneal nerve density did not correlate with clinical measures of DPN, including neuropathy symptom and disability scores, nerve conduction studies, or quantitative sensory tests. Our findings indicate that corneal and intraepidermal nerves likely mirror different aspects of nerve degeneration, where only intraepidermal nerves appear to reflect the clinical status of DPN, suggesting that scrutiny is warranted concerning methodologies of studies using corneal nerves to assess DPN.
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| 13. |
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| 14. |
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| 15. |
- Björkman-Burtscher, Isabella, et al.
(författare)
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Proton MR spectroscopy and preoperative diagnostic accuracy: an evaluation of intracranial mass lesions characterized by stereotactic biopsy findings
- 2000
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Ingår i: AJNR. - 1936-959X. ; 21:1, s. 84-93
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: MR imaging has made it easier to distinguish among the different types of intracranial mass lesions. Nevertheless, it is sometimes impossible to base a diagnosis solely on clinical and neuroradiologic findings, and, in these cases, biopsy must be performed. The purpose of this study was to evaluate the hypothesis that proton MR spectroscopy is able to improve preoperative diagnostic accuracy in cases of intracranial tumors and may therefore obviate stereotactic biopsy. METHODS: Twenty-six patients with intracranial tumors underwent MR imaging, proton MR spectroscopy, and stereotactic biopsy. MR spectroscopic findings were evaluated for the distribution pattern of pathologic spectra (NAA/Cho ratio < 1) across the lesion and neighboring tissue, for signal ratios in different tumor types, and for their potential to improve preoperative diagnostic accuracy. RESULTS: Gliomas and lymphomas showed pathologic spectra outside the area of contrast enhancement while four nonastrocytic circumscribed tumors (meningioma, pineocytoma, metastasis, and germinoma) showed no pathologic spectra outside the region of enhancement. No significant correlation was found between different tumor types and signal ratios. MR spectroscopy improved diagnostic accuracy by differentiating infiltrative from circumscribed tumors; however, diagnostic accuracy was not improved in terms of differentiating the types of infiltrative or circumscribed lesions. CONCLUSION: MR spectroscopy can improve diagnostic accuracy by differentiating circumscribed brain lesions from histologically infiltrating processes, which may be difficult or impossible solely on the basis of clinical or neuroradiologic findings.
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| 16. |
- Bocci, Matteo, et al.
(författare)
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Infection of Brain Pericytes Underlying Neuropathology of COVID-19 Patients.
- 2021
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Ingår i: International journal of molecular sciences. - : MDPI AG. - 1422-0067 .- 1661-6596. ; 22:21
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Tidskriftsartikel (refereegranskat)abstract
- A wide range of neurological manifestations have been associated with the development of COVID-19 following SARS-CoV-2 infection. However, the etiology of the neurological symptomatology is still largely unexplored. Here, we used state-of-the-art multiplexed immunostaining of human brains (n = 6 COVID-19, median age = 69.5 years; n = 7 control, median age = 68 years) and demonstrated that expression of the SARS-CoV-2 receptor ACE2 is restricted to a subset of neurovascular pericytes. Strikingly, neurological symptoms were exclusive to, and ubiquitous in, patients that exhibited moderate to high ACE2 expression in perivascular cells. Viral dsRNA was identified in the vascular wall and paralleled by perivascular inflammation, as signified by T cell and macrophage infiltration. Furthermore, fibrinogen leakage indicated compromised integrity of the blood-brain barrier. Notably, cerebrospinal fluid from additional 16 individuals (n = 8 COVID-19, median age = 67 years; n = 8 control, median age = 69.5 years) exhibited significantly lower levels of the pericyte marker PDGFRβ in SARS-CoV-2-infected cases, indicative of disrupted pericyte homeostasis. We conclude that pericyte infection by SARS-CoV-2 underlies virus entry into the privileged central nervous system space, as well as neurological symptomatology due to perivascular inflammation and a locally compromised blood-brain barrier.
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| 17. |
- Boza-Serrano, Antonio, et al.
(författare)
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Galectin-3, a novel endogenous TREM2 ligand, detrimentally regulates inflammatory response in Alzheimer’s disease
- 2019
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 138:2, s. 251-273
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer’s disease (AD) is a progressive neurodegenerative disease in which the formation of extracellular aggregates of amyloid beta (Aβ) peptide, fibrillary tangles of intraneuronal tau and microglial activation are major pathological hallmarks. One of the key molecules involved in microglial activation is galectin-3 (gal3), and we demonstrate here for the first time a key role of gal3 in AD pathology. Gal3 was highly upregulated in the brains of AD patients and 5xFAD (familial Alzheimer’s disease) mice and found specifically expressed in microglia associated with Aβ plaques. Single-nucleotide polymorphisms in the LGALS3 gene, which encodes gal3, were associated with an increased risk of AD. Gal3 deletion in 5xFAD mice attenuated microglia-associated immune responses, particularly those associated with TLR and TREM2/DAP12 signaling. In vitro data revealed that gal3 was required to fully activate microglia in response to fibrillar Aβ. Gal3 deletion decreased the Aβ burden in 5xFAD mice and improved cognitive behavior. Interestingly, a single intrahippocampal injection of gal3 along with Aβ monomers in WT mice was sufficient to induce the formation of long-lasting (2 months) insoluble Aβ aggregates, which were absent when gal3 was lacking. High-resolution microscopy (stochastic optical reconstruction microscopy) demonstrated close colocalization of gal3 and TREM2 in microglial processes, and a direct interaction was shown by a fluorescence anisotropy assay involving the gal3 carbohydrate recognition domain. Furthermore, gal3 was shown to stimulate TREM2–DAP12 signaling in a reporter cell line. Overall, our data support the view that gal3 inhibition may be a potential pharmacological approach to counteract AD.
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| 18. |
- Brabec, Jan, et al.
(författare)
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Coregistered histology sections with diffusion tensor imaging data at 200 µm resolution in meningioma tumors
- 2023
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Ingår i: Data in Brief. - 2352-3409. ; 48
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Tidskriftsartikel (refereegranskat)abstract
- A significant problem in diffusion MRI (dMRI) is the lack of understanding regarding which microstructural features account for the variability in the diffusion tensor imaging (DTI) parameters observed in meningioma tumors. A common assumption is that mean diffusivity (MD) and fractional anisotropy (FA) from DTI are inversely proportional to cell density and proportional to tissue anisotropy, respectively. Although these associations have been established across a wide range of tumors, they have been challenged for interpreting within-tumor variations where several additional microstructural features have been suggested as contributing to MD and FA.To facilitate the investigation of the biological underpinnings of DTI parameters, we performed ex-vivo DTI at 200 µm isotropic resolution on 16 excised meningioma tumor samples. The samples exhibit a variety of microstructural features because the dataset includes meningiomas of six different meningioma types and two different grades. Diffusion-weighted signal (DWI) maps, DWI maps averaged over all directions for given b-value, signal intensities without diffusion encoding (S0) as well as DTI parameters: MD, FA, in-plane FA (FAIP), axial diffusivity (AD) and radial diffusivity (RD), were coregistered to Hematoxylin & Eosin- (H&E) and Elastica van Gieson-stained (EVG) histological sections by a non-linear landmark-based approach.Here, we provide DWI signal and DTI maps coregistered to histology sections and describe the pipeline for processing the raw DTI data and the coregistration. The raw, processed, and coregistered data are hosted by Analytic Imaging Diagnostics Arena (AIDA) data hub registry, and software tools for processing are provided via GitHub. We hope that data can be used in research and education concerning the link between the meningioma microstructure and parameters obtained by DTI.
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| 19. |
- Brabec, Jan, et al.
(författare)
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Histogram analysis of tensor-valued diffusion MRI in meningiomas : Relation to consistency, histological grade and type
- 2022
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Ingår i: NeuroImage: Clinical. - : Elsevier BV. - 2213-1582. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Preoperative radiological assessment of meningioma characteristics is of value for pre- and post-operative patient management, counselling, and surgical approach.PURPOSE: To investigate whether tensor-valued diffusion MRI can add to the preoperative prediction of meningioma consistency, grade and type.MATERIALS AND METHODS: 30 patients with intracranial meningiomas (22 WHO grade I, 8 WHO grade II) underwent MRI prior to surgery. Diffusion MRI was performed with linear and spherical b-tensors with b-values up to 2000 s/mm2. The data were used to estimate mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis (MK) and its components-the anisotropic and isotropic kurtoses (MKA and MKI). Meningioma consistency was estimated for 16 patients during resection based on ultrasonic aspiration intensity, ease of resection with instrumentation or suction. Grade and type were determined by histopathological analysis. The relation between consistency, grade and type and dMRI parameters was analyzed inside the tumor ("whole-tumor") and within brain tissue in the immediate periphery outside the tumor ("rim") by histogram analysis.RESULTS: Lower 10th percentiles of MK and MKA in the whole-tumor were associated with firm consistency compared with pooled soft and variable consistency (n = 7 vs 9; U test, p = 0.02 for MKA 10 and p = 0.04 for MK10) and lower 10th percentile of MD with variable against soft and firm (n = 5 vs 11; U test, p = 0.02). Higher standard deviation of MKI in the rim was associated with lower grade (n = 22 vs 8; U test, p = 0.04) and in the MKI maps we observed elevated rim-like structure that could be associated with grade. Higher median MKA and lower median MKI distinguished psammomatous type from other pooled meningioma types (n = 5 vs 25; U test; p = 0.03 for MKA 50 and p = 0.03 and p = 0.04 for MKI 50).CONCLUSION: Parameters from tensor-valued dMRI can facilitate prediction of consistency, grade and type.
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| 20. |
- Brabec, Jan, et al.
(författare)
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Meningioma microstructure assessed by diffusion MRI : An investigation of the source of mean diffusivity and fractional anisotropy by quantitative histology
- 2023
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Ingår i: NeuroImage: Clinical. - : Elsevier BV. - 2213-1582. ; 37
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mean diffusivity (MD) and fractional anisotropy (FA) from diffusion MRI (dMRI) have been associated with cell density and tissue anisotropy across tumors, but it is unknown whether these associations persist at the microscopic level.PURPOSE: To quantify the degree to which cell density and anisotropy, as determined from histology, account for the intra-tumor variability of MD and FA in meningioma tumors. Furthermore, to clarify whether other histological features account for additional intra-tumor variability of dMRI parameters.MATERIALS AND METHODS: We performed ex-vivo dMRI at 200 μm isotropic resolution and histological imaging of 16 excised meningioma tumor samples. Diffusion tensor imaging (DTI) was used to map MD and FA, as well as the in-plane FA (FA IP). Histology images were analyzed in terms of cell nuclei density (CD) and structure anisotropy (SA; obtained from structure tensor analysis) and were used separately in a regression analysis to predict MD and FA IP, respectively. A convolutional neural network (CNN) was also trained to predict the dMRI parameters from histology patches. The association between MRI and histology was analyzed in terms of out-of-sample (R 2 OS) on the intra-tumor level and within-sample R 2 across tumors. Regions where the dMRI parameters were poorly predicted from histology were analyzed to identify features apart from CD and SA that could influence MD and FA IP, respectively. RESULTS: Cell density assessed by histology poorly explained intra-tumor variability of MD at the mesoscopic level (200 μm), as median R 2 OS = 0.04 (interquartile range 0.01-0.26). Structure anisotropy explained more of the variation in FA IP (median R 2 OS = 0.31, 0.20-0.42). Samples with low R 2 OS for FA IP exhibited low variations throughout the samples and thus low explainable variability, however, this was not the case for MD. Across tumors, CD and SA were clearly associated with MD (R 2 = 0.60) and FA IP (R 2 = 0.81), respectively. In 37% of the samples (6 out of 16), cell density did not explain intra-tumor variability of MD when compared to the degree explained by the CNN. Tumor vascularization, psammoma bodies, microcysts, and tissue cohesivity were associated with bias in MD prediction based solely on CD. Our results support that FA IP is high in the presence of elongated and aligned cell structures, but low otherwise. CONCLUSION: Cell density and structure anisotropy account for variability in MD and FA IP across tumors but cell density does not explain MD variations within the tumor, which means that low or high values of MD locally may not always reflect high or low tumor cell density. Features beyond cell density need to be considered when interpreting MD.
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| 21. |
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| 22. |
- Brunnström, Hans, et al.
(författare)
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A 76-year-old man with cognitive and neurological symptoms
- 2009
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Ingår i: Brain Pathology. - : Wiley. - 1750-3639 .- 1015-6305. ; 19:4, s. 4-731
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A 76-year-old man presented with cognitive symptoms, followed by headache and weakness of the lower limbs and left arm. The clinical course was progressive but fluctuating. On magnetic resonance imaging (MRI), a contrast-enhancing lesion 1 cm in diameter was seen in the left temporal lobe. This lesion became attenuated and a new contrast-enhancing lesion 1 x 2 cm was seen in the left frontal lobe on a subsequent MRI. Following additional tests, treatment with corticosteroids for presumptive neurosarcoidosis was started, however, he soon expired. At autopsy, there was a tumor-like mass in the left frontal lobe. Pathologic evaluation revealed a primary T-cell lymphoma of the central nervous system (CNS). CNS T-cell lymphomas may be difficult to diagnose, even histologically, due to their frequent small cell morphology and lack of significant atypia.
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| 23. |
- Brunnström, Hans, et al.
(författare)
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Cause of death in patients with dementia disorders.
- 2009
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Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 16, s. 488-492
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Tidskriftsartikel (refereegranskat)abstract
- Background: Investigations on cause of death may provide valuable information about life expectancy and on conditions of terminal dementia care, which perhaps can be ameliorated. Methods: The autopsy reports were studied on all patients (n = 524; 55.3% females; median age 80 years) with a clinically and neuropathologically diagnosed dementia disorder who underwent a complete autopsy at the University Hospital in Lund, Sweden, during 1974-2004. Results: The two most common causes of death were bronchopneumonia (38.4%) and ischaemic heart disease (23.1%), whilst neoplastic diseases were uncommon (3.8%). In a general population of elderly studied for comparison, bronchopneumonia accounted for 2.8%, ischaemic heart disease for 22.0%, and neoplasm for 21.3% of the deaths. Amongst the demented patients, circulatory and respiratory system diseases were the causes of death in 23.2% and 55.5% of the Alzheimer patients, respectively, whilst the corresponding figures were 54.8% and 33.1% for the patients with vascular dementia. Conclusions: In patients with dementia, pneumonia as the immediate cause of death may reflect a terminal stage in which patient care and feeding is difficult to manage well. Knowledge about what actually causes death is of value in the terminal care of patients with dementia disorders.
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| 24. |
- Brunnström, Hans, et al.
(författare)
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Cerebrospinal fluid biomarker results in relation to neuropathological dementia diagnoses.
- 2010
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Ingår i: Alzheimer's & dementia. - : Wiley. - 1552-5279 .- 1552-5260. ; 6:2, s. 104-109
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Clinical dementia diagnoses are not always consistent with neuropathological findings. As correct diagnosis is important for treatment and care, new diagnostic possibilities for dementia are in demand. Cerebrospinal fluid biomarkers should ideally be able to identify ongoing processes in the brain, but need to be further compared with neuropathological findings for evaluation of their diagnostic validity. METHODS: This study included 43 patients with a clinical dementia disorder. All patients were neuropathologically examined at the University Hospital in Lund, Sweden, during the years 2001-2008, and all had a lumbar puncture carried out as part of the clinical investigation during the time of cognitive impairment. RESULTS: Of eight patients, five with Alzheimer's disease had elevated total tau protein (T-tau) and decreased amyloid beta 1-42 protein (Abeta42), while both values for the other three patients were normal. Slightly elevated T-tau and/or decreased Abeta42 were also seen in several patients with other dementia diagnoses such as Lewy body disease, frontotemporal lobar degeneration and vascular dementia. Furthermore, T-tau levels did not differ markedly between patients with morphologically tau-positive and tau-negative frontotemporal lobar degeneration. Also, seven of nine patients with Creutzfeldt-Jacob disease exhibited pronounced elevation in T-tau concentration. CONCLUSION: From this rather limited study, being the first of its kind in Sweden, we may conclude that there is no perfect concordance between cerebrospinal fluid biomarker levels and pathological findings, which should be taken into account in the clinical diagnostic setting.
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| 25. |
- Brunnström, Hans, et al.
(författare)
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Clinicopathological concordance in dementia diagnostics.
- 2009
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Ingår i: The American Journal of Geriatric Psychiatry. - 1545-7214. ; 17:8, s. 664-670
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Accurate distinction between dementia subtypes is important for patient care and pharmacological treatment. Continuing systematic comparisons of clinical and neuropathological dementia diagnoses may provide a basis for further improvement of the diagnostic procedure. The purpose of this study was to investigate concordance between clinical dementia diagnosis and neuropathological findings in the specialized dementia care. METHODS: Inclusion required 1) a clinical dementia disorder diagnosed at a hospital-based memory clinic and 2) a neuropathological examination within the Department of Pathology at the University Hospital in Lund, Sweden, during the years 1996-2006. A total of 176 consecutive patients fulfilled the criteria and were thus included. Clinical dementia diagnoses were obtained from the medical records and compared with the neuropathological findings. RESULTS: The clinical and pathological dementia diagnoses were in full accordance in 86 (49%) of the patients (kappa 0.37). In an additional 24 (14%) cases, the clinical diagnosis corresponded with some but not all pathological components judged to contribute to the dementia disorder. Of the patients with clinical Alzheimer disease, 84% (46/55) had a significant Alzheimer component with or without other significant pathology at neuropathological examination. The corresponding figure for vascular dementia (VaD) was 59% (24/41), for frontotemporal dementia 74% (20/27), for combined Alzheimer and VaD 25% (4/16), and for dementia with Lewy bodies 67% (6/9). CONCLUSIONS: This study shows that clinical dementia diagnoses do not always correspond with neuropathological changes. It stresses the importance of neuropathological examination in research and in daily clinical practice.
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