| 1. |
- Lindblom, Rickard, 1981-, et al.
(författare)
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Mechanical Reperfusion Following Prolonged Global Cerebral Ischemia Attenuates Brain Injury
- 2021
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Ingår i: Journal of Cardiovascular Translational Research. - : Springer Science and Business Media LLC. - 1937-5387 .- 1937-5395. ; 14:2, s. 338-347
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Tidskriftsartikel (refereegranskat)abstract
- Previous experiments demonstrated improved outcome following prolonged cerebral ischemia given controlled brain reperfusion using extracorporeal circulation. The current study further investigates this. Young adult pigs were exposed to 30 min of global normothermic cerebral ischemia, achieved through intrathoracic clamping of cerebral arteries, followed by 20 min of isolated mechanical brain reperfusion. Leukocyte-filtered blood was delivered by a roller-pump at fixed pressure and flow. One experimental group additionally had a custom-made buffer solution delivered at 1:8 ratio with the blood. Hemodynamics including intracranial pressure were monitored. Blood gases were from peripheral arteries and the sagittal sinus, and intraparenchymal brain microdialysis was performed. The brains were examined by a neuropathologist. The group with the added buffer showed lower intracranial pressure as well as decreased intraparenchymal glycerol and less signs of excitotoxicity and ischemia, although histology revealed similar degrees of injury. A customized mechanical reperfusion improves multiple parameters after prolonged normothermic global cerebral ischemia. [Figure not available: see fulltext.]
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Ekman, Linnéa, et al.
(författare)
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Evaluation of small nerve fiber dysfunction in type 2 diabetes
- 2020
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 141:1, s. 38-46
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To assess potential correlations between intraepidermal nerve fiber densities (IENFD), graded with light microscopy, and clinical measures of peripheral neuropathy in elderly male subjects with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and type 2 diabetes (T2DM), respectively. Materials and methods: IENFD was assessed in thin sections of skin biopsies from distal leg in 86 men (71-77 years); 24 NGT, 15 IGT, and 47 T2DM. Biopsies were immunohistochemically stained for protein gene product (PGP) 9.5, and intraepidermal nerve fibers (IENF) were quantified manually by light microscopy. IENFD was compared between groups with different glucose tolerance and related to neurophysiological tests, including nerve conduction study (NCS; sural and peroneal nerve), quantitative sensory testing (QST), and clinical examination (Total Neuropathy Score; Neuropathy Symptom Score and Neuropathy Disability Score). Results: Absent IENF was seen in subjects with T2DM (n = 10; 21%) and IGT (n = 1; 7%) but not in NGT. IENFD correlated weakly negatively with HbA1c (r = −.268, P =.013) and Total Neuropathy Score (r = −.219, P =.042). Positive correlations were found between IENFD and sural nerve amplitude (r =.371, P =.001) as well as conduction velocity of both the sural (r =.241, P =.029) and peroneal nerve (r =.258, P =.018). Proportions of abnormal sural nerve amplitude became significantly higher with decreasing IENFD. No correlation was found with QST. Inter-rater reliability of IENFD assessment was good (ICC = 0.887). Conclusions: Signs of neuropathy are becoming more prevalent with decreasing IENFD. IENFD can be meaningfully evaluated in thin histopathological sections using the presented technique to detect neuropathy.
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| 5. |
- Zampeli, Ariadne, et al.
(författare)
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Structural association between heterotopia and cortical lesions visualised with 7 T MRI in patients with focal epilepsy
- 2022
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Ingår i: Seizure-European Journal of Epilepsy. - : Elsevier BV. - 1059-1311 .- 1532-2688. ; 101, s. 177-183
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To analyze structural characteristics of malformations of cortical development (MCD) at 7T and 3T MRI. Methods: Twenty-five patients were examined with a 7T MRI-scanner in addition to 3T examinations performed for epilepsy evaluation. 7T sequences included a 3D-T1-weighted (T1w) MPRAGE, 3D-T2w FLAIR, and heavily T2w axial and coronal high-resolution (0.5 x 0.5 x 0.75-1.0 mm3) 2D-TSE sequences. Images were reviewed for 7T MRI imaging characteristics of MCD, visibility and frequency of identified lesions on 7T and on 3T (original reports and second reading). Results: In 25 patients 112 lesions were identified (57 gray matter (GM) heterotopia, 37 focal cortical dysplasia (FCD), and 18 other MCD). Imaging characteristics of the 37 FCD were cortical thickening (n = 11); GM-WM border blurring (n = 30); GM signal intensity changes (n = 18); juxtacortical WM signal intensity changes (n = 18); and transmantle WM signal intensity changes (n = 11). None of the 7T MRI sequences was sufficient to detect all types of lesions. Heterotopia were in general isointense to normal GM. Structural associations between 36 heterotopia and overlaying cortex were observed, composed either of a direct connection, vessel-like struc-tures, or GM-like bridges. FCD were mentioned in 30% (11 of 37) of the original reports at 3T, and in 57% (21 of 37) after second reading. FCD connections to subcortical heterotopia were clinically not reported at all. Conclusion: 7T MRI revealed subtle connections between heterotopia and previous unidentified pathology in overlaying cortex. These findings may be significant for the understanding of the anatomical seizure origin and propagation pathways.
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| 6. |
- Ek Olofsson, Henric, et al.
(författare)
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Are cortical microvascular raspberries caused by cerebral hypoperfusion? An exploratory pathological study
- 2021
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Ingår i: Cerebral Circulation - Cognition and Behavior. - : Elsevier BV. - 2666-2450. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: This retrospective study investigated a cortical microvascular formation, termed a ‘raspberry’ due to its appearance under a bright-field microscope. We examined whether there is support for the hypothesis that raspberry formation is an angiogenic process induced by cerebral hypoperfusion. Materials and Methods: Raspberries were manually quantified in haematoxylin and eosin-stained cortical sections from the anterior frontal lobe of deceased individuals who had undergone a diagnostic neuropathological examination at the Department of Pathology, Lund, Sweden, during April 2019–January 2021. Subjects represented consecutively received cases during this 22-month period. The raspberry density was compared between subjects according to variables collected from medical records and autopsy reports: age, sex, hypertension, diabetes mellitus, atrial fibrillation, orthostatic hypotension, chronic heart failure, acute circulatory failure, aortic atherosclerosis, atherosclerosis of the basal cerebral arteries (referred to as ‘cerebral atherosclerosis’), cerebral small vessel disease, cerebral amyloid angiopathy, cerebral infarction, and ischaemic white matter disease. Results: 62 subjects were included. The mean age was 71.9 years (range 46–97 years). 21 subjects (33.9%) were female. Independent-samples t-test showed a higher raspberry density in subjects with cerebral atherosclerosis (p = 0.029; 95% CI 0.7, 11.6 raspberries/cm²). The higher raspberry density in subjects with cerebral atherosclerosis remained in multiple linear regression (p = 0.003; 95% CI 2.3, 11.1 raspberries/cm²). Conclusion: This exploratory study indicates that cortical raspberries could be associated with cerebral atherosclerosis. The remaining results were inconclusive but motivate further examination of variables such as acute circulatory failure.
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| 7. |
- Ek Olofsson, Henric, et al.
(författare)
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Cortical microvascular raspberries and ageing : an independent but not exclusive relationship
- 2023
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Ingår i: Acta Neuropathologica Communications. - 2051-5960. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Raspberries are cerebral microvascular formations of unknown origin, defined as three or more transversally sectioned vascular lumina surrounded by a common perivascular space. We have previously demonstrated an increased raspberry density in the cortex of patients with vascular dementia and cerebral atherosclerosis, while studies by other authors on overlapping and synonymously defined vascular entities mainly associate them with advancing age. The aim of the present study was to examine the relationship between raspberries and age in a large study sample while including multiple potential confounding factors in the analysis.Materials and methods: Our study sample consisted of 263 individuals aged 20–97 years who had undergone a clinical autopsy including a neuropathological examination. The cortical raspberry density had either been quantified as part of a previous study or was examined de novo in a uniform manner on haematoxylin- and eosin-stained tissue sections from the frontal lobe. The medical records and autopsy reports were assessed regarding neurodegeneration, cerebral infarcts, cerebral atherosclerosis and small vessel disease, cardiac hypertrophy, nephrosclerosis, hypertension, and diabetes mellitus. With the patients grouped according to 10-year age interval, non-parametric tests (the Kruskal–Wallis test, followed by pairwise testing with Bonferroni-corrected P values) and multiple linear regression models (not corrected for multiple tests) were performed.Results: The average raspberry density increased with advancing age. The non-parametric tests demonstrated statistically significant differences in raspberry density when comparing the groups aged 60–99 years and 70–99 years to those aged 20–29 years (P < 0.012) and 30–59 years (P < 0.011), respectively. The multiple linear regression models demonstrated positive associations with age interval (P < 0.001), cerebral atherosclerosis (P = 0.024), cardiac hypertrophy (P = 0.021), hypertension subgrouped for organ damage (P = 0.006), and female sex (P = 0.004), and a tendency towards a negative association with Alzheimer’s disease neuropathologic change (P = 0.048).Conclusion: The raspberry density of the frontal cortex increases with advancing age, but our results also indicate associations with acquired pathologies. Awareness of the biological and pathological context where raspberries occur can guide further research on their origin.
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| 8. |
- Ek Olofsson, Henric, et al.
(författare)
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On the regional distribution of cerebral microvascular ‘raspberries’ and their association with cerebral atherosclerosis and acute circulatory failure
- 2023
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Ingår i: Cerebral Circulation - Cognition and Behavior. - : Elsevier BV. - 2666-2450. ; 4, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionIn this follow-up study, cerebral microvascular formations termed ‘raspberries’ were quantified according to cerebral atherosclerosis (C-ASCL) and acute circulatory failure (ACF). We also examined the regional distribution of raspberries throughout the brain.Materials and methodsThe study population consisted of adult individuals who had undergone a diagnostic neuropathological autopsy. Groups were formed to examine the association between raspberries, C-ASCL and ACF (control group, C-ASCL group, C-ASCL+ACF group [n = 47 per group] and a combined C-ASCL-tot group [n = 94]). To examine the regional distribution, additional groups were formed based on previously known raspberry densities of the frontal cortex (high-, medium- and low-density group [n = 6 per group]). Raspberries were quantified on scanned haematoxylin-eosin-stained sections.ResultsCortical raspberry density did not differ at a statistically significant level between the control group, the C-ASCL group and the C-ASCL+ACF group (P = 0.10) but did so between the control group and the C-ASCL-tot group (P = 0.033). The total raspberry density of the high-, medium- and low-density groups differed at a statistically significant level (P = 0.005), which remained in group-to-group comparisons of the high- and medium-density groups (P = 0.015) and the high- and low-density groups (P = 0.002). Raspberries were rare in cerebral white matter and in the cerebellum.ConclusionAn association between raspberry density and C-ASCL is supported but is weaker than previously indicated. An association with ACF is not indicated. The raspberry density of the frontal cortex provides an approximation of the brain's total raspberry density.
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| 9. |
- Endisch, Christian, et al.
(författare)
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Hypoxic-Ischemic Encephalopathy Evaluated by Brain Autopsy and Neuroprognostication after Cardiac Arrest
- 2020
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Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149. ; 77:11, s. 1430-1439
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Neuroprognostication studies are potentially susceptible to a self-fulfilling prophecy as investigated prognostic parameters may affect withdrawal of life-sustaining therapy. Objective: To compare the results of prognostic parameters after cardiac arrest (CA) with the histopathologically determined severity of hypoxic-ischemic encephalopathy (HIE) obtained from autopsy results. Design, Setting, and Participants: In a retrospective, 3-center cohort study of all patients who died following cardiac arrest during their intensive care unit stay and underwent autopsy between 2003 and 2015, postmortem brain histopathologic findings were compared with post-CA brain computed tomographic imaging, electroencephalographic (EEG) findings, somatosensory-evoked potentials, and serum neuron-specific enolase levels obtained during the intensive care unit stay. Data analysis was conducted from 2015 to 2020. Main Outcomes and Measures: The severity of HIE was evaluated according to the selective eosinophilic neuronal death (SEND) classification and patients were dichotomized into categories of histopathologically severe and no/mild HIE. Results: Of 187 included patients, 117 were men (63%) and median age was 65 (interquartile range, 58-74) years. Severe HIE was found in 114 patients (61%) and no/mild HIE was identified in 73 patients (39%). Severe HIE was found in all 21 patients with bilaterally absent somatosensory-evoked potentials, all 15 patients with gray-white matter ratio less than 1.10 on brain computed tomographic imaging, all 9 patients with suppressed EEG, 15 of 16 patients with burst-suppression EEG, and all 29 patients with neuron-specific enolase levels greater than 67 μg/L more than 48 hours after CA without confounders. Three of 7 patients with generalized periodic discharges on suppressed background and 1 patient with burst-suppression EEG had a SEND 1 score (<30% dead neurons) in the cerebral cortex, but higher SEND scores (>30% dead neurons) in other oxygen-sensitive brain regions. Conclusions and Relevance: In this study, histopathologic findings suggested severe HIE after cardiac arrest in patients with bilaterally absent cortical somatosensory-evoked potentials, gray-white matter ratio less than 1.10, highly malignant EEG, and serum neuron-specific enolase concentration greater than 67 μg/L.
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| 10. |
- Garza, Raquel, et al.
(författare)
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Single-cell transcriptomics of human traumatic brain injury reveals activation of endogenous retroviruses in oligodendroglia
- 2023
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Ingår i: Cell Reports. - : Elsevier. - 2211-1247. ; 42:11, s. 113395-
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) is a leading cause of chronic brain impairment and results in a robust, but poorly understood, neuroinflammatory response that contributes to the long-term pathology. We used single-nuclei RNA sequencing (snRNA-seq) to study transcriptomic changes in different cell populations in human brain tissue obtained acutely after severe, life-threatening TBI. This revealed a unique transcriptional response in oligodendrocyte precursors and mature oligodendrocytes, including the activation of a robust innate immune response, indicating an important role for oligodendroglia in the initiation of neuroinflammation. The activation of an innate immune response correlated with transcriptional upregulation of endogenous retroviruses in oligodendroglia. This observation was causally linked in vitro using human glial progenitors, implicating these ancient viral sequences in human neuroinflammation. In summary, this work provides insight into the initiating events of the neuroinflammatory response in TBI, which has therapeutic implications.
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