| 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. |
- 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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| 3. |
- 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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| 4. |
- Forsberg, Anton
(författare)
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Amyloid imaging in Alzheimer’s disease and mild cognitive impairment by positron emission tomography
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Effectiveness of future treatment strategies in Alzheimer s disease (AD) will rely on early detection of disease and the possibility to clearly evaluate their effects. The findings presented in this thesis concerns both early in vivo detection of amyloid deposition in the brains of patients at risk of developing AD and the longitudinal changes of pathological and functional parameters in patients with AD. A couple of years ago the first study with in vivo detection of amyloid using the radiotracer N-methyl [11C] 2-(4´-methylaminophenyl)-6-hydroxy-benzothiazole also known as 11C-Pittsburgh Compound B (11C-PIB) with positron emission tomography (PET) was performed in collaboration between researchers in Pittsburgh, USA, Uppsala and Stockholm, Sweden. This first study showed a significant difference between AD patients and healthy controls in regards to their 11C-PIB retention. The research presented in this thesis is both continuations and new investigations based on this initial research. Results obtained in the studies presented in this thesis showed that the amyloid deposition is an early event in the development of AD present already in patients with mild cognitive impairment (MCI) that later develop AD. We could also show that the amyloid deposition in brain was closely correlated to concentrations of pathological biomarkers in the cerebrospinal fluid (CSF) at an early stage. While functional decline with decreased cerebral metabolic rate of glucose (CMRglc) measured with 18F-FDG PET and episodic memory tests did not show a relationship in MCI patients but did at the clinical stage of AD. Our results also suggests that the early deposition of amyloid increase to a certain level and then reaches a plateau as shown by a quite stable 11C-PIB retention in AD patients followed for a mean period of 2.5 years. We could also show that the dynamic 11C-PIB PET scan do not only contain information on amyloid load but also information on brain function as the early frames contain a blood flow component that is related to CMRglc. The general conclusions to be drawn from these studies are that 11C-PIB PET shows promising results of both early detection of disease and the possibility to use it for evaluation of current and future anti-amyloid therapies. The possibility to extract functional information will further increase the usefulness of 11C-PIB PET in AD research and clinical assessment of dementia.
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| 5. |
- Forsberg, Anton, et al.
(författare)
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Low background and high contrast PET imaging of amyloid-β with [11C]AZD2995 and [11C]AZD2184 in Alzheimer's disease patients
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer-Verlag New York. - 1619-7070 .- 1619-7089. ; 40:4, s. 580-593
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to evaluate AZD2995 side by side with AZD2184 as novel PET radioligands for imaging of amyloid-β in Alzheimer's disease (AD).METHODS: In vitro binding of tritium-labelled AZD2995 and AZD2184 was studied and compared with that of the established amyloid-β PET radioligand PIB. Subsequently, a first-in-human in vivo PET study was performed using [(11)C]AZD2995 and [(11)C]AZD2184 in three healthy control subjects and seven AD patients.RESULTS: AZD2995, AZD2184 and PIB were found to share the same binding site to amyloid-β. [(3)H]AZD2995 had the highest signal-to-background ratio in brain tissue from patients with AD as well as in transgenic mice. However, [(11)C]AZD2184 had superior imaging properties in PET, as shown by larger effect sizes comparing binding potential values in cortical regions of AD patients and healthy controls. Nevertheless, probably due to a lower amount of nonspecific binding, the group separation of the distribution volume ratio values of [(11)C]AZD2995 was greater in areas with lower amyloid-β load, e.g. the hippocampus.CONCLUSION: Both AZD2995 and AZD2184 detect amyloid-β with high affinity and specificity and also display a lower degree of nonspecific binding than that reported for PIB. Overall [(11)C]AZD2184 seems to be an amyloid-β radioligand with higher uptake and better group separation when compared to [(11)C]AZD2995. However, the very low nonspecific binding of [(11)C]AZD2995 makes this radioligand potentially interesting as a tool to study minute levels of amyloid-β. This sensitivity may be important in investigating, for example, early prodromal stages of AD or in the longitudinal study of a disease modifying therapy.
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| 6. |
- Forsberg, Anton, et al.
(författare)
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PET imaging of amyloid deposition in patients with mild cognitive impairment
- 2008
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 29:10, s. 1456-1465
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Tidskriftsartikel (refereegranskat)abstract
- It is of great clinical value to identify subjects at a high risk of developing AD. We previously found that the amyloid positron emission tomography (PET) tracer PIB showed a robust difference in retention in the brain between AD patients and healthy controls (HC). Twenty-one patients diagnosed with MCI (mean age 63.3 ± 7.8 (S.D.) years) underwent PET studies with 11C-PIB, and 18F-fluoro-deoxy-glucose (FDG) to measure cerebral glucose metabolism, as well as assessment of cognitive function and CSF sampling. Reference group data from 27 AD patients and 6 healthy controls, respectively, were used for comparison. The mean cortical PIB retention for the MCI patients was intermediate compared to HC and AD. Seven MCI patients that later at clinical follow-up converted to AD (8.1 ± 6.0 (S.D.) months) showed significant higher PIB retention compared to non-converting MCI patients and HC, respectively (ps < 0.01). The PIB retention in MCI converters was comparable to AD patients (p > 0.01). Correlations were observed in the MCI patients between PIB retention and CSF Aβ1-42, total Tau and episodic memory, respectively.
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| 7. |
- Forsberg, Anton, et al.
(författare)
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The use of PIB-PET as a dual pathological and functional biomarker in AD
- 2012
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Ingår i: Biochimica et Biophysica Acta - Molecular Basis of Disease. - : Elsevier BV. - 0925-4439 .- 1879-260X. ; 1822:3, s. 380-385
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid imaging with positron emission tomography (PET) is presently used in Alzheimer's disease (AD) research. In this study we investigated the possibility to use early frames (ePIB) of the PIB scans as a rough index of CBF by comparing normalised early PIB values with cerebral glucose metabolism (rCMRglc). PIB-PET and FDG-PET were performed in 37 AD patients, 21 subjects with mild cognitive impairment (MCI) and 6 healthy controls (HC). The patients were divided based on their PIB retention (amyloid load) as either PIB positive (PIB+) or PIB negative (PIB-). Data of the unidirectional influx K-1 from a subset of the subjects including 7 AD patients and 3 HC was used for correlative analysis. Data was analysed using regions of interest (ROI) analysis. A strong, positive correlation was observed across brain regions between K-1 and ePIB (r=0.70: p <= 0.001). The ePIB values were significantly lower in the posterior cingulate (p <= 0.001) and the parietal cortices (p = 0.002) in PIB+ subjects compared to PIB-, although the group difference were stronger for rCMRglc in cortical areas (p <= 0.001). Strong positive correlations between ePIB and rCMRglc were observed in all cortical regions analysed, especially in the posterior cingulate and parietal cortices (p <= 0.001). A single dynamic PIE-PET scan may provide information about pathological and functional changes (amyloidosis and impaired blood flow). This might be important for diagnosis of AD, enrichment of patients in clinical trials and evaluation of treatment effects.
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| 8. |
- Forsberg, Karl-Anton, et al.
(författare)
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Meanings of participating in a lifestyle programme for persons with psychiatric disabilities.
- 2011
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Ingår i: Scandinavian Journal of Caring Sciences. - : Wiley. - 0283-9318 .- 1471-6712. ; 25:2, s. 357-364
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Tidskriftsartikel (refereegranskat)abstract
- Lifestyle changes that affect physical and psychological health are described in research literature; however, the meaning of participating in a lifestyle intervention programme together with the staff has not been described. This study illuminates meanings of participating in a lifestyle programme as experienced by persons with psychiatric disabilities. The first author interviewed five women and six men with schizophrenia and depressive syndrome, aged 26-53, participating in a lifestyle programme. The transcribed interviews were analysed using a phenomenological hermeneutic approach inspired by the philosophy of Ricoeur. Meanings of participating in a lifestyle programme include my health can be improved as both the physical effects and the obstacles are considered and the daily life is partially given a changed content in new experiences and by participating in something to take pride in. The meanings of participating together with the staff mean an increased sense of closeness and equality with the staff expressed in changes in relationships and the difference between the two groups being revealed and also in becoming aware of the life situation, an insight into the loss of a healthy life but also hope for the future is expressed. The conclusions that could be drawn from this study are that a lifestyle intervention affects health and other important life areas such as the content of daily life and the relationship with the carers, which appears to affect the sense of hope and the ability to see new possibilities. Carers should find situations and activities where the residents and carers participate under equal conditions giving the residents the opportunity to leave the sick roll, experience equality and develop good relationships.
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| 9. |
- Kadir, Ahmadul, et al.
(författare)
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Dynamic changes in PET amyloid and FDG imaging at different stages of Alzheimer's disease
- 2012
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 33:1, s. 198.e1-198.e14
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Tidskriftsartikel (refereegranskat)abstract
- In this study 5 patients with mild cognitive impairment (MCI) and 9 Alzheimer’s disease (AD) patients underwent respectively 3- and 5-year follow-up positron emission tomography (PET) studies with N-methyl [11C] 2-(4-methylaminophenyl)-6-hydroxy-benzothiazole (11C-PIB) and 18F-fluorodeoxyglucose (18F-FDG) to understand the time courses in AD disease processes. Significant increase in PIB retention as well as decrease in regional cerebral metabolic rate of glucose (rCMRglc) was observed at group level in the MCI patients while no significant change was observed in cognitive function. At group level the AD patients showed unchanged high PIB retention at 5-year follow-up compared with baseline. At the individual level, increased, stable, and decreased PIB retention were observed while disease progression was reflected in significant decrease in rCMRglc and cognition. In conclusion, after a long-term follow-up with PET, we observed an increase in fibrillar amyloid load in MCI patients followed by more stable level in clinical AD patients. The rCMRglc starts to decline in MCI patients and became more pronounced in clinical stage which related to continuous decline in cognition.
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| 10. |
- Kadir, Ahmadul, et al.
(författare)
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Effect of phenserine treatment on brain functional activity and amyloid in Alzheimer's disease.
- 2008
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Ingår i: Annals of neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 63:5, s. 621-31
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The effects of (-)-phenserine (phenserine) and placebo/donepezil treatment on regional cerebral metabolic rate for glucose (rCMRglc) and brain amyloid load were investigated by positron emission tomography in 20 patients with mild Alzheimer's disease in relation to cerebrospinal fluid (CSF) and plasma biomarkers, and cognitive function. METHODS: The first 3 months of the study was a randomized, double-blind, placebo-controlled phase, during which 10 patients received phenserine (30 mg/day) and 10 patients the placebo. Three to 6 months was an open-label extension phase, during which the placebo group received donepezil (5 mg/day) and the phenserine group remained on phenserine. After 6 months, all patients received phenserine treatment up to 12 months. The patients underwent positron emission tomography examinations to measure rCMRglc (8F-FDG) and amyloid load (11C-PIB) at baseline and after 3 and 6 months of the treatment. Neuropsychological and biomarker data were collected at the three times of positron emission tomography imaging. RESULTS: Statistically significant effects on a composite neuropsychological test score were observed in the phenserine-treated group compared with the placebo and donepezil group at 3 and 6 months, respectively. Values of rCMRglc were significantly increased in several cortical regions after 3 months of phenserine treatment, compared with baseline, and correlated positively with cognitive function and CSF beta-amyloid 40 (Abeta40). Cortical Pittsburgh Compound B retention correlated negatively with CSF Abeta40 levels and the ratio Abeta/beta-secretase-cleaved amyloid precursor protein. In CSF, Abeta40 correlated positively with the attention domain of cognition. INTERPRETATION: Phenserine treatment was associated with an improvement in cognition and an increase in rCMRglc.
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