| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
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| 5. |
- Forsberg, Karl Anton, 1955-, et al.
(författare)
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Influence of a life style intervention among persons with a psychiatric disability : a cluster randomised controlled trial on symptoms, quality of life and sense of coherence
- 2010
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Ingår i: Journal of Clinical Nursing. - Malden : Wiley-Blackwell. - 0962-1067 .- 1365-2702. ; 19:11-12, s. 1519-1528
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Tidskriftsartikel (refereegranskat)abstract
- Aims and objectives: The aim of this study was to investigate how a life style intervention programme influences psychiatric and psychosocial factors among persons with psychiatric disabilities. Background: Persons with psychiatric disabilities often suffer from a simultaneous physical health problem, where circulatory disorder, hyperlipideamia, digestive disease, diabetes mellitus and obesity are prevalent. Studies have also shown a relationship between physical activity and mental health. But few randomised controlled trails have been aimed specifically at life style interventions and their effect on psychiatric health and quality of life among persons with psychiatric disabilities.Design: a cluster randomised controlled trail.Methods: Forty one persons with a DSM- ІV diagnosis in eight supported housing facilities and two housing support programmes and their carers were on cluster level randomly assigned to a 12 month health intervention programme in the form of study circles with diet sessions and physical activities or a control programme. The changes in the mean of quality of life, level of functioning, psychiatric symptoms and sense of coherence was investigated and its relationship to physical health and attendance.Results: A significant increase in the sense of coherence was seen in both programmes but also significant improvements in the intervention group compared to controls at the follow-up.Conclusions: Structured activities in the form of life style intervention programmes with a sufficient level of challenge that encourage persons with psychiatric disabilities to participate in activities in a social context may contribute to a significant increase in the sense of coherence.Relevance to clinical practice: Improving physical health with life style programmes in the form of study circles and when involving their cares will in addition to increased physical health end in improved sense of coherence.
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| 6. |
- 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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| 7. |
- 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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| 8. |
- Lundman, Berit, et al.
(författare)
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Sense of coherence (SOC) related to health and mortality among the very old : The Umeå 85+ study
- 2010
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Ingår i: Archives of gerontology and geriatrics (Print). - : Elsevier BV. - 0167-4943 .- 1872-6976. ; 51, s. 329-332
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Tidskriftsartikel (refereegranskat)abstract
- We describe associations between sense of coherence (SOC) and sense of well-being, diseases, physical function and the predictive value of SOC on depression and mortality. The study included 190 participants, aged 85-103 years. Linear correlation analysis was used for relationships between SOC scores and continuous variables. The effects of SOC score on 1- and 4-year mortality, as well as on depression at the 5-year follow-up, were investigated using Cox regression models. The mean SOC score was 71.8+/-10.2 (+/-S.D.). SOC score was positively related to well-being (p
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| 9. |
- Nordberg, Agneta, et al.
(författare)
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A European multicentre PET study of fibrillar amyloid in Alzheimer's disease
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 40:1, s. 104-114
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid PET tracers have been developed for in vivo detection of brain fibrillar amyloid deposition in Alzheimer's disease (AD). To serve as an early biomarker in AD the amyloid PET tracers need to be analysed in multicentre clinical studies. In this study 238 [C-11]Pittsburgh compound-B (PIB) datasets from five different European centres were pooled. Of these 238 datasets, 18 were excluded, leaving [C-11]PIB datasets from 97 patients with clinically diagnosed AD (mean age 69 +/- 8 years), 72 patients with mild cognitive impairment (MCI; mean age 67.5 +/- 8 years) and 51 healthy controls (mean age 67.4 +/- 6 years) available for analysis. Of the MCI patients, 64 were longitudinally followed for 28 +/- 15 months. Most participants (175 out of 220) were also tested for apolipoprotein E (ApoE) genotype. [C-11]PIB retention in the neocortical and subcortical brain regions was significantly higher in AD patients than in age-matched controls. Intermediate [C-11]PIB retention was observed in MCI patients, with a bimodal distribution (64 % MCI PIB-positive and 36 % MCI PIB-negative), which was significantly different the pattern in both the AD patients and controls. Higher [C-11]PIB retention was observed in MCI ApoE epsilon 4 carriers compared to non-ApoE epsilon 4 carriers (p < 0.005). Of the MCI PIB-positive patients, 67 % had converted to AD at follow-up while none of the MCI PIB-negative patients converted. This study demonstrated the robustness of [C-11]PIB PET as a marker of neocortical fibrillar amyloid deposition in brain when assessed in a multicentre setting. MCI PIB-positive patients showed more severe memory impairment than MCI PIB-negative patients and progressed to AD at an estimated rate of 25 % per year. None of the MCI PIB-negative patients converted to AD, and thus PIB negativity had a 100 % negative predictive value for progression to AD. This supports the notion that PIB-positive scans in MCI patients are an indicator of prodromal AD.
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| 10. |
- Schain, Martin, et al.
(författare)
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Arterial input function derived from pairwise correlations between PET-image voxels
- 2013
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : Nature Publishing Group. - 0271-678X .- 1559-7016. ; 33:7, s. 1058-1065
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Tidskriftsartikel (refereegranskat)abstract
- A metabolite corrected arterial input function is a prerequisite for quantification of positron emission tomography (PET) data by compartmental analysis. This quantitative approach is also necessary for radioligands without suitable reference regions in brain. The measurement is laborious and requires cannulation of a peripheral artery, a procedure that can be associated with patient discomfort and potential adverse events. A non invasive procedure for obtaining the arterial input function is thus preferable. In this study, we present a novel method to obtain image-derived input functions (IDIFs). The method is based on calculation of the Pearson correlation coefficient between the time-activity curves of voxel pairs in the PET image to localize voxels displaying blood-like behavior. The method was evaluated using data obtained in human studies with the radioligands [11C]flumazenil and [11C]AZ10419369, and its performance was compared with three previously published methods. The distribution volumes (VT) obtained using IDIFs were compared with those obtained using traditional arterial measurements. Overall, the agreement in VT was good (~3% difference) for input functions obtained using the pairwise correlation approach. This approach performed similarly or even better than the other methods, and could be considered in applied clinical studies. Applications to other radioligands are needed for further verification.
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