| 1. |
- Albrecht, Daniel S., et al.
(författare)
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Brain glial activation in fibromyalgia - A multi-site positron emission tomography investigation
- 2019
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 75, s. 72-83
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Tidskriftsartikel (refereegranskat)abstract
- Fibromyalgia (FM) is a poorly understood chronic condition characterized by widespread musculoskeletal pain, fatigue, and cognitive difficulties. While mounting evidence suggests a role for neuroinflammation, no study has directly provided evidence of brain glial activation in FM. In this study, we conducted a Positron Emission Tomography (PET) study using [C-11]PBR28, which binds to the translocator protein (TSPO), a protein upregulated in activated microglia and astrocytes. To enhance statistical power and generalizability, we combined datasets collected independently at two separate institutions (Massachusetts General Hospital [MGH] and Karolinska Institutet [KI]). In an attempt to disentangle the contributions of different glial cell types to FM, a smaller sample was scanned at KI with [C-11]-L-deprenyl-D2 PET, thought to primarily reflect astrocytic (but not microglial) signal. Thirty-one FM patients and 27 healthy controls (HC) were examined using [C-11]PBR28 PET. 11 FM patients and 11 HC were scanned using [C-11]-L-deprenyl-D2 PET. Standardized uptake values normalized by occipital cortex signal (SUVR) and distribution volume (V-T) were computed from the [C-11]PBR28 data. [C-11]-L-deprenyl-D2 was quantified using lambda k(3). PET imaging metrics were compared across groups, and when differing across groups, against clinical variables. Compared to HC, FM patients demonstrated widespread cortical elevations, and no decreases, in [C-11]PBR28 ITT and SUVR, most pronounced in the medial and lateral walls of the frontal and parietal lobes. No regions showed significant group differences in [C-11]-L-deprenyl-Ds signal, including those demonstrating elevated [C-11] PBR28 signal in patients (p's >= 0.53, uncorrected). The elevations in [C-11]PBR28 V-T and SUVR were correlated both spatially (i.e., were observed in overlapping regions) and, in several areas, also in terms of magnitude. In exploratory, uncorrected analyses, higher subjective ratings of fatigue in FM patients were associated with higher [C-11] PBR28 SUVR in the anterior and posterior middle cingulate cortices (p's < 0.03). SUVR was not significantly associated with any other clinical variable. Our work provides the first in vivo evidence supporting a role for glial activation in FM pathophysiology. Given that the elevations in [C-11]PBR28 signal were not also accompanied by increased [C-11]-deprenyl-D2 signal, our data suggests that microglia, but not astrocytes, may be driving the TSPO elevation in these regions. Although [C-11]-L-deprenyl-D2 signal was not found to be increased in FM patients, larger studies are needed to further assess the role of possible astrocytic contributions in FM. Overall, our data support glial modulation as a potential therapeutic strategy for FM.
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| 2. |
- Amer, Ayad, et al.
(författare)
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YopN and TyeA Hydrophobic Contacts Required for Regulating Ysc-Yop Type III Secretion Activity by Yersinia pseudotuberculosis
- 2016
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Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media SA. - 2235-2988. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Yersinia bacteria target Yop effector toxins to the interior of host immune cells by the Ysc-Yop type III secretion system. A YopN-TyeA heterodimer is central to controlling Ysc-Yop targeting activity. A + 1 frameshift event in the 3-prime end of yopN can also produce a singular secreted YopN-TyeA polypeptide that retains some regulatory function even though the C-terminal coding sequence of this YopN differs greatly from wild type. Thus, this YopN C-terminal segment was analyzed for its role in type III secretion control. Bacteria producing YopN truncated after residue 278, or with altered sequence between residues 279 and 287, had lost type III secretion control and function. In contrast, YopN variants with manipulated sequence beyond residue 287 maintained full control and function. Scrutiny of the YopN-TyeA complex structure revealed that residue W279 functioned as a likely hydrophobic contact site with TyeA. Indeed, a YopNW279G mutant lost all ability to bind TyeA. The TyeA residue F8 was also critical for reciprocal YopN binding. Thus, we conclude that specific hydrophobic contacts between opposing YopN and TyeA termini establishes a complex needed for regulating Ysc-Yop activity.
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| 3. |
- Behzadi, Arvin, 1994-
(författare)
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Biomarkers for diagnosis and prognosis in amyotrophic lateral sclerosis
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by loss of upper and lower motor neurons, leading to paresis, muscle atrophy, and respiratory failure. ALS can be difficult to diagnose and prognosticate early.Aim: To investigate the diagnostic and prognostic characteristics of biomarkers in cerebrospinal fluid (CSF), plasma, and skeletal muscle tissue in patients with ALS.Paper I: Neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH) were analyzed in CSF using enzyme-linked immunosorbent assay (ELISA), and NFL in plasma was analyzed using single-molecule array (SIMOA). CSF NFL, CSF pNFH, and plasma NFL concentrations can differentiate ALS patients from ALS mimics, and were significantly negatively correlated with the disease duration in ALS patients.Paper II: Myosin heavy chain (MyHC) isoforms in extraocular muscles were investigated using immunofluorescence. Control donors had significantly higher proportion of myofibers containing MyHCIIa and significantly lower proportion of myofibers containing MyHCeom in the global layer compared to spinal-onset ALS and bulbar-onset ALS donors. Disease duration in the spinal-onset ALS donors was significantly correlated with the proportion of myofibers containing MyHCIIa in the global layer and MyHCeom in the orbital layer.Paper III: The study combined the neurofilament concentrations from Paper I, with cytokines previously analyzed in CSF and plasma using SIMOA, to investigate distinct molecular phenotypes in ALS. Patients with bulbar-onset ALS had significantly higher concentrations of CSF tumor necrosis factor α (TNF-α) compared to ALS mimics. TNF-α and NFL were significantly correlated with each other in both CSF and plasma in ALS patients. Combined analysis of NFL and IL-6 in plasma identified molecular prognostic subgroups in ALS patients.Paper IV: Creatine kinase (CK), high-sensitivity cardiac troponin T (hs-cTnT), hs-cTnI, and cystatin C (CysC) were analyzed in plasma in a fully accredited laboratory. CK and hs-cTnT concentrations were significantly elevated in limb-onset ALS compared to controls and bulbar-onset ALS. hs-cTnT concentrations were significantly elevated in truncal-onset ALS compared to controls and bulbar-onset ALS. Multivariable Cox proportional hazards models indicated elevated concentrations of CysC as a significant marker for worse prognosis in ALS.Conclusions: The papers report diagnostic and prognostic characteristics of biomarkers in CSF, plasma, and muscle tissue in ALS patients. The significant findings for biomarkers in plasma could be of value since plasma sampling does not involve a lumbar puncture.
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| 6. |
- Behzadi, Arvin, et al.
(författare)
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Neurofilaments can differentiate ALS subgroups and ALS from common diagnostic mimics.
- 2021
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Delayed diagnosis and misdiagnosis are frequent in people with amyotrophic lateral sclerosis (ALS), the most common form of motor neuron disease (MND). Neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH) are elevated in ALS patients. We retrospectively quantified cerebrospinal fluid (CSF) NFL, CSF pNFH and plasma NFL in stored samples that were collected at the diagnostic work-up of ALS patients (n = 234), ALS mimics (n = 44) and controls (n = 9). We assessed the diagnostic performance, prognostication value and relationship to the site of onset and genotype. CSF NFL, CSF pNFH and plasma NFL levels were significantly increased in ALS patients compared to patients with neuropathies & myelopathies, patients with myopathies and controls. Furthermore, CSF pNFH and plasma NFL levels were significantly higher in ALS patients than in patients with other MNDs. Bulbar onset ALS patients had significantly higher plasma NFL levels than spinal onset ALS patients. ALS patients with C9orf72HRE mutations had significantly higher plasma NFL levels than patients with SOD1 mutations. Survival was negatively correlated with all three biomarkers. Receiver operating characteristics showed the highest area under the curve for CSF pNFH for differentiating ALS from ALS mimics and for plasma NFL for estimating ALS short and long survival. All three biomarkers have diagnostic value in differentiating ALS from clinically relevant ALS mimics. Plasma NFL levels can be used to differentiate between clinical and genetic ALS subgroups.
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| 7. |
- Bendtsen Kronkvist, Maria, et al.
(författare)
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Service user participation in decision-making : a qualitative study from a services user’s perspective
- 2023
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Ingår i: Journal of Public Mental Health. - : Emerald Group Publishing Limited. - 1746-5729 .- 2042-8731. ; 22:4, s. 157-169
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this study is to describe participation in decision-making among service users with severe mental illness.Design/methodology/approach: Service users want to participate in decision-making and in the planning of their care. There are widely known methods, such as shared decision-making, that could be used to facilitate service user participation. Three focus group interviews were conducted with the participation of 14 persons with mental illness and/or substance abuse who were service users at two Swedish Homes for Care and Residence (HVB). Data were analyzed by qualitative content analysis.Findings: Two themes emerged: service users’ involvement in decisions is hampered by the professionals’ approach and adequate information and experience of participation means greater empowerment.Research limitations/implications: Although it is known that service users would like to have more influence, and that methods like shared decision-making are recommended to empower service users and improve the decision process, research on these matters is limited.Practical implications: This study reveals that there is a need of more systematic decisional support, such as shared decision-making, so that service users can be seen as important persons not only in guidelines and policy documents but also in clinical practice.Social implications: The findings indicate that service users do not participate in decisions systematically, although policies, guidelines and laws providing that service users should be offered an active part in decision-making with regard to their care and treatment.Originality/value: Although it is known that service users would like to have more influence, and that methods like shared decision-making are recommended to empower service users and improve their decision process, research on these matters is limited. The findings indicate that service users do not participate in decisions systematically, even though policies, guidelines and laws are in place stipulating that service users should be offered an active part in decision-making with regard to their own care and treatment. The results of this project bring improvement opportunities to light.
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| 8. |
- Bendtsen Kronkvist, Maria, et al.
(författare)
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User participation in decision-making : a qualitative intervention study on mental health professionals’ experiences
- 2022
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Ingår i: Journal of Public Mental Health. - : Emerald Group Publishing Limited. - 1746-5729 .- 2042-8731. ; 21:3, s. 250-261
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this study was to describe mental health professionals’ experiences of changes in attitudes towards, and knowledge about, users of mental health-care recovery and decisional participation in clinical practice after an educational intervention.Design/methodology/approach: Users of mental health care want to participate in decisions regarding their own mental health care. Shared decision-making as a method is coherent with recovery orientation in mental health services and results in better-informed patients and fewer conflicts regarding decisions. A qualitative intervention study was designed to evaluate changes in attitudes and knowledge about mental health recovery in Sweden. Nine participants were interviewed, and the data were analysed by content analysis.Findings: Three categories were generated from the analysis: Increased theoretical knowledge, changing attitudes about practical approaches and the significance of social factors in recovery.Originality/value: When shared decision-making is to be implemented in mental health, professionals need to gain knowledge about recovery and need to adopt changed roles as health professionals. Educational interventions therefore seem necessary if such changes are to happen.
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| 9. |
- Darreh-Shori, Taher, et al.
(författare)
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Differential levels of apolipoprotein E and butyrylcholinesterase show strong association with pathological signs of Alzheimer's disease in the brain in vivo
- 2011
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 32:12, s. 2320.e15-2320.e32
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Tidskriftsartikel (refereegranskat)abstract
- Recently, we reported that 3 of the known risk factors of Alzheimer's disease (AD), i.e., advanced age, apolipoprotein E (ApoE) ε4, and female gender, are associated with differential levels of ApoE proteins and butyrylcholinesterase (BuChE) in the cerebrospinal fluid (CSF) of AD patients. The ApoE ε4 allele and certain BuChE polymorphisms synergistically affect the conversion rate of mild cognitive impairment (MCI) to AD. Here, we investigated interrelationships between ApoE and BuChE levels, and pathological markers of AD in vivo. CSF from patients with probable AD, assessed for cerebral glucose metabolism (CMRglc; n = 50) and Pittsburgh compound B (PIB) retention (β-amyloid [Aβ] load, n = 29) by positron emission tomography (PET), was used for measurement of BuChE, ApoE, Aβ, tau, phosphorylated tau (P-tau) and interleukin-1β (IL-1β) levels. Levels of ApoE and BuChE strongly correlated with CMRglc (fluorodeoxyglucose [FDG]-PET, r = 0.54, p < 0.0001, n = 50), cerebral Aβ load (PIB retention, r = 0.73, p < 0.0001, n = 29), and CSF P-tau (r = 0.73, p < 0.0001, n = 33). High ApoE protein was tied to low CMRglc and high PIB retention and P-tau. BuChE levels had opposite relationships. Other CSF covariates were levels of interleukin-1β and Aβ42peptide. The pattern of the patients' cognitive Z-scores strongly supported these observations. High ApoE protein was also linked to changes in 3 of the biodynamic properties of BuChE. In vitro analysis indicated that high ApoE protein levels were related to an increased pool of dormant BuChE molecules with an abnormally high intrinsic catalytic rate in CSF, which was “turned on” by excess Aβ peptides. The findings suggest that abnormally high levels of ApoE may play a causative role in the pathological events of AD, particularly those involving the early cholinergic deficit in the AD brain, through modulation of cholinesterases activities, hence disturbing the acetylcholine-dependent activity of neurons and nonexcitable cells such as glial cells.
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| 10. |
- Engler, Henry, et al.
(författare)
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Two-year follow-up of amyloid deposition in patients with Alzheimer's disease
- 2006
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 129:Pt 11, s. 2856-2866
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Tidskriftsartikel (refereegranskat)abstract
- Beta amyloid is one of the major histopathological hallmarks of Alzheimer's disease. We recently reported in vivo imaging of amyloid in 16 Alzheimer patients, using the PET ligand N-methyl[11C]2-(4'-methylaminophenyl)-6-hydroxy-benzothiazole (PIB). In the present study we rescanned these 16 Alzheimer patients after 2.0 +/- 0.5 years and have described the interval change in amyloid deposition and regional cerebral metabolic rate for glucose (rCMRGlc) at follow-up. Sixteen patients with Alzheimer's disease were re-examined by means of PET, using PIB and 2-[18F]fluoro-2-deoxy-d-glucose (FDG) after 2.0 +/- 0.5 years. The patients were all on cholinesterase inhibitor treatment and five also on treatment with the N-methyl-d-aspartate (NMDA) antagonist memantine. In order to estimate the accuracy of the PET PIB measurements, four additional Alzheimer patients underwent repeated examinations with PIB within 20 days (test-retest). Relative PIB retention in cortical regions differed by 3-7% in the test-retest study. No significant difference in PIB retention was observed between baseline and follow-up while a significant (P < 0.01) 20% decrease in rCMRGlc was observed in cortical brain regions. A significant negative correlation between rCMRGlc and PIB retention was observed in the parietal cortex in the Alzheimer patients at follow-up (r = 0.67, P = 0.009). A non-significant decline in Mini-Mental State Examination (MMSE) score from 24.3 +/- 3.7 (mean +/- standard deviation) to 22.7 +/- 6.1 was measured at follow-up. Five of the Alzheimer patients showed a significant decline in MMSE score of >3 (21.4 +/- 3.5 to 15.6 +/- 3.9, P < 0.01) (AD-progressive) while the rest of the patients were cognitively more stable (MMSE score = 25.6 +/- 3.1 to 25.9 +/- 3.7) (AD-stable) compared with baseline. A positive correlation (P = 0.001) was observed in the parietal cortex between Rey Auditory Verbal Learning (RAVL) test score and rCMRGlc at follow-up while a negative correlation (P = 0.018) was observed between RAVL test and PIB retention in the parietal at follow-up. Relatively stable PIB retention after 2 years of follow-up in patients with mild Alzheimer's disease suggests that amyloid deposition in the brain reaches a plateau by the early clinical stages of Alzheimer's disease and therefore may precede a decline in rCMRGlc and cognition. It appears that anti-amyloid therapies will need to induce a significant decrease in amyloid load in order for PIB PET images to detect a drug effect in Alzheimer patients. FDG imaging may be able to detect a stabilization of cerebral metabolism caused by therapy administered to patients with a clinical diagnosis of Alzheimer's disease.
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