| 1. |
- Axelsson, Robert, et al.
(författare)
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Evaluation of Multi-level Social Learning for Sustainable Landscapes : Perspective of a Development Initiative in Bergslagen, Sweden
- 2013
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Ingår i: Ambio. - : Springer Netherlands. - 0044-7447 .- 1654-7209. ; 42:2, s. 241-253
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Tidskriftsartikel (refereegranskat)abstract
- To implement policies about sustainable landscapes and rural development necessitates social learning about states and trends of sustainability indicators, norms that define sustainability, and adaptive multi-level governance. We evaluate the extent to which social learning at multiple governance levels for sustainable landscapes occur in 18 local development initiatives in the network of Sustainable Bergslagen in Sweden. We mapped activities over time, and interviewed key actors in the network about social learning. While activities resulted in exchange of experiences and some local solutions, a major challenge was to secure systematic social learning and make new knowledge explicit at multiple levels. None of the development initiatives used a systematic approach to secure social learning, and sustainability assessments were not made systematically. We discuss how social learning can be improved, and how a learning network of development initiatives could be realized.
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| 2. |
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| 3. |
- Björkstrand, Johannes, et al.
(författare)
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Decrease in amygdala activity during repeated exposure to spider images predicts avoidance behavior in spider fearful individuals.
- 2020
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Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Spider phobia is characterized by exaggerated fear of situations where spiders could be present, resulting in avoidance of such situations and compromised quality of life. An important component in psychological treatment of spider phobia is exposure to phobic situations that reduces avoidance behaviors. At the neural level, amygdala responses to phobic material are elevated, but normalizes following exposure treatment. To what extent amygdala activity decreases during a session of repeated phobic stimulation, and whether activity decrease is related to subsequent avoidance is not well studied. We hypothesized reduced amygdala activity during the course of repeated exposure to spider pictures, and that the degree of reduction would predict subsequent avoidance of spider pictures. To test our hypothesis, functional magnetic resonance imaging was performed in 45 individuals with spider fear during repeated exposure to spider pictures. Results showed that repeated exposure to spider stimuli attenuated amygdala reactivity and individual differences in activity reductions predicted subsequent avoidance behavior to spider pictures in an incentive-conflict task, with larger attenuations predicting less avoidance. At 6-month follow up, initial reductions in amygdala activation still predicted avoidance. This result demonstrates that reduction in amygdala responses is related to clinically meaningful outcomes in human anxiety, and suggests that within-session reductions in amygdala responses could be an important mechanism explaining the clinical effects of exposure therapy.
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| 4. |
- Björkstrand, Johannes, et al.
(författare)
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Disrupting Reconsolidation Attenuates Long-Term Fear Memory in the Human Amygdala and Facilitates Approach Behavior
- 2016
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 26:19, s. 2690-95
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Tidskriftsartikel (refereegranskat)abstract
- Memories become labile and malleable to modification when recalled [1]. Fear-conditioning experiments in both rodents and humans indicate that amygdala-localized short-term fear memories can be attenuated by disruption of their reconsolidation with extinction training soon after memory activation [2-7]. However, this may not be true for natural long-term fears. Studies in rodents indicate that although it is possible to disrupt the reconsolidation of older memories [8-11], they appear to be more resistant [1, 3, 9, 12, 13]. In humans, 1-week-old conditioned fear memories have been attenuated by behaviorally induced disruption of reconsolidation [14], but it remains to be seen whether this is possible for naturally occurring long-term fears and whether the underlying neural mechanisms are similar to those found in experimental fear-conditioning paradigms. Using functional brain imaging in individuals with a lifelong fear of spiders, we show that fear memory activation followed by repeated exposure to feared cues after 10 min, which disrupts reconsolidation, attenuates activity in the basolateral amygdala at re-exposure 24 hr later. In contrast, repeated exposure 6 hr after fear memory activation, which allows for reconsolidation, did not attenuate amygdala activity. Disrupted, but not undisrupted, reconsolidation facilitated approach behavior to feared cues, and approach behavior was inversely related to amygdala activity during re-exposure. We conclude that memory activation immediately preceding exposure attenuates the neural and behavioral expression of decades-old fear memories and that, similar to experimentally induced fear memories, the basolateral amygdala is crucially involved in this process.
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| 5. |
- Björkstrand, Johannes, et al.
(författare)
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Think twice, it's all right : Long lasting effects of disrupted reconsolidation on brain and behavior in human long-term fear
- 2017
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328 .- 1872-7549. ; 324, s. 125-129
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Tidskriftsartikel (refereegranskat)abstract
- Memories can be modified when recalled. Experimental fear conditioning studies support that amygdala-localized fear memories are attenuated when reconsolidation is disrupted through extinction training immediately following memory activation. Recently, using functional brain imaging in individuals with lifelong spider fears, we demonstrated that fear memory activation followed by repeated exposure to feared cues after 10 min, thereby disrupting reconsolidation, attenuated activity in the amygdala during later re-exposure, and also facilitated approach behavior to feared cues. In contrast, repeated exposure 6 h after fear memory activation, allowing for reconsolidation, did not attenuate amygdala activity and resulted in less approach behavior as compared to the group that received disrupted reconsolidation. We here evaluated if these effects are stable after 6 months and found that amygdala activity was further reduced in both groups, with a tendency towards greater reductions in the 10 min than the 6 h group. Hence, disrupted reconsolidation results in long lasting attenuation of amygdala activity. The behavioral effect, with more approach towards previously feared cues, in the 10 min than the 6 h group also persisted. Thus, the brain effect of disrupted reconsolidation is stable over 6 months and the behavioral effect also remained. We therefore conclude that disrupted reconsolidation result in a long-lasting diminished fear memory representation in the amygdala which may have clinical importance.
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| 6. |
- Costache, Madalina Elena, et al.
(författare)
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Higher- and lower-order personality traits and cluster subtypes in social anxiety disorder
- 2020
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 15:4
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Tidskriftsartikel (refereegranskat)abstract
- Social anxiety disorder (SAD) can come in different forms, presenting problems for diagnostic classification. Here, we examined personality traits in a large sample of patients (N = 265) diagnosed with SAD in comparison to healthy controls (N = 164) by use of the Revised NEO Personality Inventory (NEO-PI-R) and Karolinska Scales of Personality (KSP). In addition, we identified subtypes of SAD based on cluster analysis of the NEO-PI-R Big Five personality dimensions. Significant group differences in personality traits between patients and controls were noted on all Big Five dimensions except agreeableness. Group differences were further noted on most lower-order facets of NEO-PI-R, and nearly all KSP variables. A logistic regression analysis showed, however, that only neuroticism and extraversion remained significant independent predictors of patient/control group when controlling for the effects of the other Big Five dimensions. Also, only neuroticism and extraversion yielded large effect sizes when SAD patients were compared to Swedish normative data for the NEO-PI-R. A two-step cluster analysis resulted in three separate clusters labelled Prototypical (33%), Introvert-Conscientious (29%), and Instable-Open (38%) SAD. Individuals in the Prototypical cluster deviated most on the Big Five dimensions and they were at the most severe end in profile analyses of social anxiety, self-rated fear during public speaking, trait anxiety, and anxiety-related KSP variables. While additional studies are needed to determine if personality subtypes in SAD differ in etiological and treatment-related factors, the present results demonstrate considerable personality heterogeneity in socially anxious individuals, further underscoring that SAD is a multidimensional disorder.
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| 7. |
- Eriksdotter, Maria, et al.
(författare)
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Plasma Fatty Acid Profiles in Relation to Cognition and Gender in Alzheimer's Disease Patients During Oral Omega-3 Fatty Acid Supplementation : The OmegAD Study
- 2015
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 48:3, s. 805-812
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: ω3 fatty acids (ω3 FAs) may slow the rate of decline in cognitive performance in mild forms of cognitive impairment and Alzheimer's disease (AD). However, the relationship between changes of plasma ω3 FA levels and cognitive performance, as well as effects of gender, are poorly known.OBJECTIVE: To study the effect of 6-month administration of DHA-rich ω3 FA supplementation on plasma FA profiles in patients with mild to moderate AD in relation to cognitive performance and gender. This investigation is part of the OmegAD Study.METHODS: 174 AD patients (74 ± 9 years) were randomized to a daily intake of 2.3 g ω3 FA or placebo for 6 months; subsequently all received the ω3 FA preparation for the next 6 months. Baseline as well as changes in plasma levels of the main ω3 FAs in 165 patients, while receiving ω3 FA supplementation for 6 months, were analyzed for association to cognitive performance (assessed by ADAS-cog and MMSE scores) as well as to gender.RESULTS: Preservation of cognitive functioning, assessed by ADAS-cog or its sub-items (but not MMSE) scores, was significantly associated to increasing plasma ω3 FA levels over time. Thus, the higher ω3 FA plasma levels rose, the lower was the rate of cognitive deterioration. This effect was not related to gender; since although females displayed higher ω3 FA plasma levels than did males after 6 months of supplementation, this difference disappeared when adjusted for body weight.CONCLUSIONS: Since our study suggests dose-response relationships between plasma levels of ω3 FA and preservation of cognition, future ω3 FA trials in patients with mild AD should consider exploring graded (and body weight adjusted) doses of ω3 FA.
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| 8. |
- Faria, Vanda, et al.
(författare)
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Do You Believe It? Verbal Suggestions Influence the Clinical and Neural Effects of Escitalopram in Social Anxiety Disorder : A Randomized Trial
- 2017
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 24, s. 179-188
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Tidskriftsartikel (refereegranskat)abstract
- Background: Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for depression and anxiety, but their efficacy relative to placebo has been questioned. We aimed to test how manipulation of verbally induced expectancies, central for placebo, influences SSRI treatment outcome and brain activity in patients with social anxiety disorder (SAD).Methods: We did a randomized clinical trial, within an academic medical center (Uppsala, Sweden), of individuals fulfilling the DSM-IV criteria for SAD, recruited through media advertising. Participants were 18 years or older and randomized in blocks, through a computer-generated sequence by an independent party, to nine weeks of overt or covert treatment with escitalopram(20 mg daily). The overt group received correct treatment information whereas the covert group was treated deceptively with the SSRI described, by the psychiatrist, as active placebo. The treating psychiatrist was necessarily unmasked while the research staff was masked from intervention assignment. Treatment efficacy was assessed primarily with the self-rated Liebowitz Social Anxiety Scale (LSAS-SR), administered at week 0, 1, 3, 6 and 9, also yielding a dichotomous estimate of responder status (clinically significant improvement). Before and at the last week of treatment, brain activity during an emotional face-matching task was assessed with functional magnetic resonance imaging (fMRI) and during fMRI sessions, anticipatory speech anxiety was also assessed with the Spielberger State-Trait Anxiety Inventory - State version (STAI-S). Analyses included all randomized patients with outcome data at posttreatment. This study is registered at ISRCTN, number 98890605.Findings: Between March 17th 2014 and May 22nd 2015, 47 patients were recruited. One patient in the covert group dropped out after a few days of treatment and did not provide fMRI data, leaving 46 patients with complete outcome data. After nine weeks of treatment, overt (n = 24) as compared to covert (n = 22) SSRI administration yielded significantly better outcome on the LSAS-SR (adjusted difference 21.17, 95% CI 10.69–31.65, p < 0.0001) with more than three times higher response rate (50% vs. 14%; χ2(1) = 6.91, p = 0.009) and twice the effect size (d = 2.24 vs. d = 1.13) from pre-to posttreatment. There was no significant between-group difference on anticipatory speech anxiety (STAI-S), both groups improving with treatment. No serious adverse reactions were recorded. On fMRI outcomes, there was suggestive evidence for a differential neural response to treatment between groups in the posterior cingulate, superior temporal and inferior frontal gyri (all z thresholds exceeding 3.68, p ≤ 0.001). Reduced social anxiety with treatment correlated significantly with enhanced posterior cingulate (z threshold 3.24, p = 0.0006) and attenuated amygdala (z threshold 2.70, p = 0.003) activity.Interpretation: The clinical and neural effects of escitalopram were markedly influenced by verbal suggestions. This points to a pronounced placebo component in SSRI-treatment of SAD and favors a biopsychosocial over a biomedical explanatory model for SSRI efficacy.
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| 9. |
- Faxen-Irving, Gerd, et al.
(författare)
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Does Fatty Acid Composition in Subcutaneous Adipose Tissue Differ between Patients with Alzheimer's Disease and Cohabiting Proxies?
- 2018
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 61:2, s. 515-519
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Tidskriftsartikel (refereegranskat)abstract
- Low tissue levels of the major marine ω3 fatty acids (FAs) DHA and EPA are found in Alzheimer's disease (AD). We investigated if healthy proxies to AD patients have higher levels of these ω3 FAs. We observed lower levels of EPA and DHA in subcutaneous adipose tissue biopsies from 64 AD patients compared with 16 cognitively healthy proxies. No significant difference was observed when pairwise comparisons were made between a subset of 16 AD patients and their co-habiting proxies. Larger studies are needed to replicate these findings and to determine if they could depend on FA intake or differences in metabolism.
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| 10. |
- Faxén-Irving, Gerd, et al.
(författare)
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Effects on transthyretin in plasma and cerebrospinal fluid by DHA-rich n - 3 fatty acid supplementation in patients with Alzheimer's disease : the OmegAD study
- 2013
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 36:1, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Transthyretin (TTR) binds amyloid-β (Aβ) and may reduce brain Aβ, a pathological feature in Alzheimer's disease (AD). N - 3 fatty acids (FA), docosahexaenoic (DHA), and eicosapentaenoic acid (EPA) may increase TTR transcription in rat hippocampus. We studied effects of n - 3 FA supplementation on TTR-levels in patients with AD. Outpatients were randomized to receive 1.7 g DHA and 0.6 g EPA (n - 3/n - 3 group) or placebo (placebo/n - 3 group) during 6 months. After 6 months, all patients received n - 3 FA for another 6 months. TTR and FA were measured in plasma in all subjects, whereas TTR in cerebrospinal fluid (CSF) was measured in a subgroup. The study was completed by 89 patients in the n - 3/n - 3 group (75 y, 57% w) and 85 in the placebo/n - 3 group (75 y, 46% w). Baseline plasma-TTR was within normal range in both groups. After 6 months, plasma-TTR decreased in the placebo/n - 3 group (p < 0.001 within and p < 0.015 between the groups). No changes were observed in CSF TTR. From 6 to 12 months when both groups were supplemented, plasma-TTR increased significantly in both groups. Repeated measures ANOVA indicated an increase in TTR over time (p = 0.04) in those receiving n - 3 FA for 12 months. By linear regression analyses, n - 3 FA treatment was independently associated with increased plasma-TTR at 6 months (β = -0.172, p = 0.028). Thus, n - 3 FA treatment appeared to increase plasma-TTR in patients with AD. Since TTR may influence Aβ deposition in the brain, the results warrant further exploration.
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| 11. |
- Freund-Levi, Yvonne, 1956-, et al.
(författare)
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Effects of omega-3 fatty acids on inflammatory markers in cerebrospinal fluid and plasma in Alzheimer's disease : the OmegAD study
- 2009
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger. - 1420-8008 .- 1421-9824. ; 27:5, s. 481-490
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: omega-3 fatty acids (omega-3 FAs) found in dietary fish or fish oils are anti-inflammatory agents that may influence Alzheimer's disease (AD).OBJECTIVE: To study the effects of dietary omega-3 FA supplementation on inflammatory markers in cerebrospinal fluid (CSF) and plasma from patients with mild to moderate AD.METHODS: Thirty-five patients (70.3 +/- 8.2 years) were randomized to a daily intake of 2.3 g omega-3 FAs or placebo for 6 months. The inflammatory markers interleukin (IL)-6, tumour necrosis factor-alpha and soluble interleukin-1 receptor type II (sIL-1RII) were analysed in CSF and plasma at baseline and at 6 months. The AD markers tau-protein, hyperphosphorylated tau-protein and beta-amyloid (Abeta(1-42)) were assessed in CSF. High-sensitivity C-reactive protein was assessed in plasma. A possible relation to the APOE genotype was investigated.RESULTS: There was no significant treatment effect of omega-3 FAs on inflammatory and AD biomarkers in CSF or on inflammatory markers in plasma, nor was there any relation with APOE. A significant correlation was observed at baseline between sIL-1RII and Abeta(1-42) levels in CSF.CONCLUSIONS: Treatment of AD patients with omega-3 FAs for 6 months did not influence inflammatory or biomarkers in CSF or plasma. The correlation between sIL-1RII and Abeta(1-42) may reflect the reciprocal interactions between IL-1 and Abeta peptides.
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| 12. |
- Freund-Levi, Yvonne, 1956-, et al.
(författare)
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Effects of supplementation with omega-3 fatty acids on oxidative stress and inflammation in patients with Alzheimer's disease : the OmegAD study
- 2014
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 42:3, s. 823-831
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oxidative stress and inflammation are two key mechanisms suggested to be involved in the pathogenesis of Alzheimer's disease (AD). Omega-3 fatty acids (ω-3 FAs) found in fish and fish oil have several biological properties that may be beneficial in AD. However, they may also auto-oxidize and induce in vivo lipid peroxidation.OBJECTIVE: The objective of this study was to evaluate systemic oxidative stress and inflammatory biomarkers following oral supplementation of dietary ω-3 FA.METHODS: Forty patients with moderate AD were randomized to receive 1.7 g DHA (22:6) and 0.6 g EPA (20:5) or placebo for 6 months. Urinary samples were collected before and after supplementation. The levels of the major F2-isoprostane, 8-iso-PGF2α, a consistent in vivo biomarker of oxidative stress, and 15-keto-dihydro-PGF2α, a major metabolite of PGF2α and biomarker of inflammatory response, were measured.RESULTS: F2-isoprostane in urine increased in the placebo group after 6 months, but there was no clear difference in treatment effect between supplemented and non-supplemented patients on the urinary levels of F2-isoprostanes and 15-keto-dihydro-PGF2α. At baseline, the levels of 15-keto-dihydro-PGF2α showed negative correlative relationships to ω-3 FAs, and a positive correlation to linoleic acid. 8-iso-PGF2α correlated negatively to the ω-6 FA arachidonic acid.CONCLUSION: The findings indicate that supplementation of ω-3 FAs to patients with AD for 6 months does not have a clear effect on free radical-mediated formation of F2-isoprostane or cyclooxygenase-mediated formation of prostaglandin F2α. The correlative relationships to FAs indicate a potential role of FAs in immunoregulation.
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| 13. |
- Hjorth, Erik, et al.
(författare)
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Omega-3 fatty acids enhance phagocytosis of Alzheimer's disease-related amyloid-β42 by human microglia and decrease inflammatory markers
- 2013
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 35:4, s. 697-713
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Tidskriftsartikel (refereegranskat)abstract
- The use of supplements with omega-3 (ω3) fatty acids (FAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) is widespread due to proposed beneficial effects on the nervous and cardiovascular systems. Many effects of ω3 FAs are believed to be caused by down-regulation and resolution of inflammation. Alzheimer's disease (AD) is associated with inflammation mediated by microglia and astrocytes, and ω3 FAs have been proposed as potential treatments for AD. The focus of the present study is on the effects of DHA and EPA on microglial phagocytosis of the AD pathogen amyloid-β (Aβ), on secreted and cellular markers of immune activity, and on production of brain-derived neurotrophic factor (BDNF). Human CHME3 microglial cells were exposed to DHA or EPA, with or without the presence of Aβ42. Phagocytosis of Aβ42 was analyzed by flow cytometry in conjunction with immunocytochemistry using antibodies to cellular proteins. Secreted proteins were analyzed by ELISA. Both DHA and EPA were found to stimulate microglial phagocytosis of Aβ42. Phagocytosis of Aβ42 was performed by microglia with a predominance of M2 markers. EPA increased the levels of BDNF in the culture medium. The levels of TNF-α were decreased by DHA. Both DHA and EPA decreased the pro-inflammatory M1 markers CD40 and CD86, and DHA had a stimulatory effect on the anti-inflammatory M2 marker CD206. DHA and EPA can be beneficial in AD by enhancing removal of Aβ42, increasing neurotrophin production, decreasing pro-inflammatory cytokine production, and by inducing a shift in phenotype away from pro-inflammatory M1 activation.
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| 14. |
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| 15. |
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| 16. |
- Hjorth, Olof, et al.
(författare)
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Expectancy effects on serotonin and dopamine transporters during SSRI treatment of social anxiety disorder : a randomized clinical trial
- 2021
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Ingår i: Translational Psychiatry. - : Springer Nature. - 2158-3188. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- It has been extensively debated whether selective serotonin reuptake inhibitors (SSRIs) are more efficacious than placebo in affective disorders, and it is not fully understood how SSRIs exert their beneficial effects. Along with serotonin transporter blockade, altered dopamine signaling and psychological factors may contribute. In this randomized clinical trial of participants with social anxiety disorder (SAD) we investigated how manipulation of verbally-induced expectancies, vital for placebo response, affect brain monoamine transporters and symptom improvement during SSRI treatment. Twenty-seven participants with SAD (17 men, 10 women), were randomized, to 9 weeks of overt or covert treatment with escitalopram 20 mg. The overt group received correct treatment information whereas the covert group was treated deceptively with escitalopram, described as an active placebo in a cover story. Before and after treatment, patients underwent positron emission tomography (PET) assessments with the [C-11]DASB and [C-11]PE2I radiotracers, probing brain serotonin (SERT) and dopamine (DAT) transporters. SAD symptoms were measured by the Liebowitz Social Anxiety Scale. Overt was superior to covert SSRI treatment, resulting in almost a fourfold higher rate of responders. PET results showed that SERT occupancy after treatment was unrelated to anxiety reduction and equally high in both groups. In contrast, DAT binding decreased in the right putamen, pallidum, and the left thalamus with overt SSRI treatment, and increased with covert treatment, resulting in significant group differences. DAT binding potential changes in these regions correlated negatively with symptom improvement. Findings support that the anxiolytic effects of SSRIs involve psychological factors contingent on dopaminergic neurotransmission while serotonin transporter blockade alone is insufficient for clinical response.
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| 17. |
- Hjorth, Olof, et al.
(författare)
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Expression and co-expression of serotonin and dopamine transporters in social anxiety disorder : a multitracer positron emission tomography study
- 2021
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Ingår i: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 26:8, s. 3970-3979
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Tidskriftsartikel (refereegranskat)abstract
- Serotonin and dopamine are putatively involved in the etiology and treatment of anxiety disorders, but positron emission tomography (PET) studies probing the two neurotransmitters in the same individuals are lacking. The aim of this multitracer PET study was to evaluate the regional expression and co-expression of the transporter proteins for serotonin (SERT) and dopamine (DAT) in patients with social anxiety disorder (SAD). Voxel-wise binding potentials (BPND) for SERT and DAT were determined in 27 patients with SAD and 43 age- and sex-matched healthy controls, using the radioligands [11C]DASB (3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile) and [11C]PE2I (N-(3-iodopro-2E-enyl)-2beta-carbomethoxy-3beta-(4'-methylphenyl)nortropane). Results showed that, within transmitter systems, SAD patients exhibited higher SERT binding in the nucleus accumbens while DAT availability in the amygdala, hippocampus, and putamen correlated positively with symptom severity. At a more lenient statistical threshold, SERT and DAT BPND were also higher in other striatal and limbic regions in patients, and correlated with symptom severity, whereas no brain region showed higher binding in healthy controls. Moreover, SERT/DAT co-expression was significantly higher in SAD patients in the amygdala, nucleus accumbens, caudate, putamen, and posterior ventral thalamus, while lower co-expression was noted in the dorsomedial thalamus. Follow-up logistic regression analysis confirmed that SAD diagnosis was significantly predicted by the statistical interaction between SERT and DAT availability, in the amygdala, putamen, and dorsomedial thalamus. Thus, SAD was associated with mainly increased expression and co-expression of the transporters for serotonin and dopamine in fear and reward-related brain regions. Resultant monoamine dysregulation may underlie SAD symptomatology and constitute a target for treatment.
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| 18. |
- Hjorth, Olof
(författare)
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Imaging serotonin and dopamine transporters in social anxiety disorder : Characterization, treatment and expectancy effects
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The monoamines serotonin and dopamine are likely to be involved in the pathophysiology of social anxiety and other affective disorders, but their respective contributions and putative interactions in the causes and cures of these disorders are still not well understood. It is also largely unknown if and how expectations of treatment success affect brain neurochemistry and neural activations, and if expectations interact with antidepressants like selective serotonin reuptake inhibitors (SSRIs). In this thesis some of these issues were addressed by use of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Using the highly selective radiotracers [11C]DASB and [11C]PE2I to characterize the availability of serotonin (SERT) and dopamine (DAT) transporter proteins, study I compared non-displaceable binding potentials (BPND), probing the transporters, between patients with social anxiety disorder and healthy controls. Increased SERT binding was observed in the reward related region nucleus accumbens (NAcc), in the social anxiety group. Moreover, increased DAT binding was associated with severity of the disorder and social anxiety was also associated with higher SERT-DAT co-expression in fear- and reward-related areas, including the amygdala and NAcc. Study II showed that verbal instructions regarding expected treatment efficacy strongly affected the clinical outcome of SSRI-treatment. Overt treatment, when patients with social anxiety disorder were correctly informed, was vastly superior to covert SSRI treatment, when patients expected an ineffective placebo. Groups were also differentiated on objective brain activity measures. Study III further demonstrated different SERT and DAT binding changes in limbic and striatal areas with overt as compared to covert SSRI-treatment. Decreased DAT BPND in the striatum, as assessed with PET, correlated with improvement in the overt group, suggesting increased dopaminergic signalling. Study IV compared treatment-induced changes in SERT and DAT binding after cognitive-behavior therapy (CBT) combined with an SSRI or placebo in patients with social anxiety disorder. Both groups showed initial co-expression similar to study I. The SSRI+CBT and placebo+CBT combinations yielded dissimilar transporter change patterns. Higher SERT occupancy in the NAcc correlated with reduced symptoms and this relationship was moderated by the change in DAT BPND. The results of this thesis support that functional interactions between serotonin and dopamine modulate social anxiety symptomatology and are important brain targets for successful treatment. Further it demonstrates that the treatment success of SSRIs in social anxiety disorder depends on how the treatment is presented. These results can be informative for the practice of clinicians, but also highlights an ethical dilemma because a large portion of the total treatment effects is elicited by processes within the patient itself.
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| 19. |
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| 20. |
- Hjorth, Olof, et al.
(författare)
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Serotonin and dopamine transporter availability in social anxiety disorder after combined treatment with escitalopram and cognitive-behavioral therapy
- 2022
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Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Selective serotonin reuptake inhibitors (SSRIs) and internet-based cognitive behavioral therapy (ICBT) are recommended treatments of social anxiety disorder (SAD), and often combined, but their effects on monoaminergic signaling are not well understood. In this multi-tracer positron emission tomography (PET) study, 24 patients with SAD were randomized to treatment with escitalopram+ICBT or placebo+ICBT under double-blind conditions. Before and after 9 weeks of treatment, patients were examined with positron emission tomography and the radioligands [11C]DASB and [11C]PE2I, probing the serotonin (SERT) and dopamine (DAT) transporter proteins respectively. Both treatment combinations resulted in significant improvement as measured by the Liebowitz Social Anxiety Scale (LSAS). At baseline, SERT-DAT co-expression was high and, in the putamen and thalamus, co-expression showed positive associations with symptom severity. SERT-DAT co-expression was also predictive of treatment success, but predictor-outcome associations differed in direction between the treatments. After treatment, average SERT occupancy in the SSRI + ICBT group was >80%, with positive associations between symptom improvement and occupancy in the nucleus accumbens, putamen and anterior cingulate cortex. Following placebo+ICBT, SERT binding increased in the raphe nuclei. DAT binding increased in both groups in limbic and striatal areas, but relations with symptom improvement differed, being negative for SSRI + ICBT and positive for placebo + ICBT. Thus, serotonin-dopamine transporter co-expression exerts influence on symptom severity and remission rate in the treatment of social anxiety disorder. However, the monoamine transporters are modulated in dissimilar ways when cognitive-behavioral treatment is given concomitantly with either SSRI-medication or pill placebo.
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| 21. |
- Hogenkamp, Pleunie, et al.
(författare)
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Calorie anticipation alters food intake after low-caloric but not high-caloric preloads
- 2013
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Ingår i: Obesity. - : Wiley. - 1930-7381 .- 1930-739X. ; 21:8, s. 1548-1553
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cognitive factors and anticipation are known to influence food intake. The current study examined the effect of anticipation and actual consumption of food on hormone (ghrelin, cortisol, insulin) and glucose levels, appetite and ad libitum intake, to assess whether changes in hormone levels might explain the predicted differences in subsequent food intake. Design and Methods: During four breakfast sessions, participants consumed a yogurt preload that was either low-caloric (LC; 180 kcal/300 g) or high-caloric (HC; 530 kcal/300 g), and were provided with either consistent or inconsistent calorie information (i.e. stating the caloric content of the preload was low or high). Appetite ratings and hormone and glucose levels were measured at baseline (t=0), after providing the calorie information about the preload (t=20), after consumption of the preload (t=40) and just before ad libitum intake (t=60). Results: Ad libitum intake was lower after HC preloads (as compared to LC preloads; p<0.01). Intake after LC preloads was higher when provided with (consistent) LC-information (467±254 kcal) as compared to (inconsistent) HC-information (346±210 kcal), but intake after the HC preloads did not depend on the information provided (LC-info: 290±178 kcal, HC-info: 333±179 kcal; caloric load*information p=0.03). Hormone levels did not respond in an anticipatory manner, and the post-prandial responses depended on actual calories consumed. Conclusions: These results suggest that both cognitive and physiological information determine food intake. When actual caloric intake was sufficient to produce physiological satiety, cognitive factors played no role; however, when physiological satiety was limited, cognitively-induced satiety reduced intake to comparable levels.
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| 22. |
- Irving, Gerd Faxén, et al.
(författare)
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Omega-3 fatty acid supplementation effects on weight and appetite in patients with Alzheimer's disease : the omega-3 Alzheimer's disease study
- 2009
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Ingår i: Journal of The American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 57:1, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To study the effects of omega (Omega)-3 fatty acid (FA) supplements on weight and appetite in patients with mild to moderate Alzheimer's disease (AD) in relation to inflammatory biomarkers and apolipoprotein E epsilon4 (APOEepsilon4). DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Specialist memory clinics in the Stockholm catchment area. PARTICIPANTS: Two hundred four patients (aged 73+/-9, 52% women) with mild to moderate AD. INTERVENTION: Patients with AD received 1.7 g of docosahexaenoic acid (DHA) and 0.6 g of eicosapentaenoic acid (EPA) (Omega-3/Omega-3 group; n=89, aged 73+/-9, 57% women) or placebo 0.6 g of linoleic acid per day (placebo/Omega-3 group; n=85, aged 73+/-9, 46% women) for 6 months. After 6 months, all patients received DHA and EPA for another 6 months. MEASUREMENTS: Anthropometry, biochemical nutritional and inflammatory markers, and appetite assessed by caregiver. RESULTS: Mean weight and body mass index (kg/m(2)) at baseline were 70.0+/-11.8 kg and 24.3+/-3.0 kg/m(2), respectively. At 6- and 12-month follow-up, weight had increased 0.7+/-2.5 kg (P=.02) and 1.4+/-2.9 kg (P<.001) in the Omega-3/Omega-3 group. In the placebo group, weight was unchanged at 6 months but had increased (P=.01) at 12 months follow-up after Omega-3 supplementation was initiated. Appetite improved in the Omega-3/Omega-3 group over the treatment period (P=.01). In logistic regression analyses, not carrying the APOEepsilon4 allele and high plasma DHA concentrations were independently related to weight gain in the combined group of patients at 6 months follow-up. CONCLUSION: A DHA-enriched Omega-3 FA supplement may positively affect weight and appetite in patients with mild to moderate AD. Not carrying the APOEepsilon4 allele and high DHA were independently associated with weight gain.
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| 23. |
- Jernerén, Fredrik, et al.
(författare)
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Homocysteine Status Modifies the Treatment Effect of Omega-3 Fatty Acids on Cognition in a Randomized Clinical Trial in Mild to Moderate Alzheimer's Disease : The OmegAD Study
- 2019
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 69:1, s. 189-197
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Tidskriftsartikel (refereegranskat)abstract
- Background: Trials of supplementation with omega-3 fatty acids (omega 3-FAs) in patients with mild cognitive impairment or Alzheimer's disease (AD) have produced inconsistent effects on cognitive decline. There is evidence of an interaction between B vitamin status and omega 3-FAs in relation to brain atrophy and cognitive decline.Objective: We investigated whether baseline levels of plasma total homocysteine (tHcy), a marker of B vitamin status, modify the effects of omega 3-FAs supplementation on cognitive performance in moderate AD.Methods: This post hoc analysis of the OmegAD trial included 171 community-based patients with AD (MMSE >= 15): 88 patients received daily doses of 1.7 g docosahexaenoic acid and 0.6 g eicosapentaenoic acid for 6 months. Treatment outcome on cognition was analyzed according to baseline levels of tHcy using a general linear model and ANCOVA.Results: We found significant interactions between omega 3-FA supplementation and tHcy on cognition and clinical stage assessed by MMSE (p = 0.040), global CDR (p = 0.059), and CDRsob (p = 0.023), but not on ADAS-cog (p = 0.649). In patients with tHcy levels <11.7 mu mol/L, omega 3-FA supplementation improved cognitive performance as measured by MMSE (+7.1%, 95% CI: 0.59 to 13.7%, p = 0.033) and clinical status as measured by CDRsob (-22.3%, 95% CI: -5.8 to -38.7%, p = 0.009) compared with placebo.Conclusion: The effect of omega 3-FA supplementation on MMSE and CDR appears to be influenced by baseline tHcy, suggesting that adequate B vitamin status is required to obtain beneficial effects of omega 3-FA on cognition.
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| 24. |
- Jonasson, My, et al.
(författare)
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Striatal dopamine transporter and receptor availability correlate with relative cerebral blood flow measured with [11C]PE2I, [18F]FE-PE2I and [11C]raclopride PET in healthy individuals
- 2023
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : Sage Publications. - 0271-678X .- 1559-7016. ; 43:7, s. 1206-1215
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this retrospective study was to investigate relationships between relative cerebral blood flow and striatal dopamine transporter and dopamine D2/3 availability in healthy subjects. The data comprised dynamic PET scans with two dopamine transporter tracers [11C]PE2I (n = 20) and [18F]FE-PE2I (n = 20) and the D2/3 tracer [11C]raclopride (n = 18). Subjects with a [11C]PE2I scan also underwent a dynamic scan with the serotonin transporter tracer [11C]DASB. Binding potential (BPND) and relative tracer delivery (R1) values were calculated on regional and voxel-level. Striatal R1 and BPND values were correlated, using either an MRI-based volume of interest (VOI) or an isocontour VOI based on the parametric BPND image. An inter-tracer comparison between [11C]PE2I BPND and [11C]DASB R1 was done on a VOI-level and simulations were performed to investigate whether the constraints of the modeling could cause correlation of the parameters. A positive association was found between BPND and R1 for all three dopamine tracers. A similar correlation was found for the inter-tracer correlation between [11C]PE2I BPND and [11C]DASB R1. Simulations showed that this relationship was not caused by cross-correlation between parameters in the kinetic model. In conclusion, these results suggest an association between resting-state striatal dopamine function and relative blood flow in healthy subjects.
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| 25. |
- Karimi, Mohsen, et al.
(författare)
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DHA-rich n-3 fatty acid supplementation decreases DNA methylation in blood leukocytes : the OmegAD study
- 2017
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Ingår i: American Journal of Clinical Nutrition. - : HighWire Press. - 0002-9165 .- 1938-3207. ; 106:4, s. 1157-1165
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dietary fish oils, rich in long-chain n-3 (ω-3) fatty acids (FAs) [e.g., docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3)], modulate inflammatory reactions through various mechanisms, including gene expression, which is measured as messenger RNA concentration. However, the effects of long-term treatment of humans with DHA and EPA on various epigenetic factors-such as DNA methylation, which controls messenger RNA generation-are poorly described.Objective: We wanted to determine the effects of 6 mo of dietary supplementation with an n-3 FA preparation rich in DHA on global DNA methylation of peripheral blood leukocytes (PBLs) and the relation to plasma EPA and DHA concentrations in Alzheimer disease (AD) patients.Design: In the present study, DNA methylation in four 5'-cytosine-phosphate-guanine-3' (CpG) sites of long interspersed nuclear element-1 repetitive sequences was assessed in a group of 63 patients (30 given the n-3 FA preparation and 33 given placebo) as an estimation of the global DNA methylation in blood cells. Patients originated from the randomized, double-blind, placebo-controlled OmegAD study, in which 174 AD patients received either 1.7 g DHA and 0.6 g EPA (the n-3 FA group) or placebo daily for 6 mo.Results: At 6 mo, the n-3 FA group displayed marked increases in DHA and EPA plasma concentrations (2.6- and 3.5-fold), as well as decreased methylation in 2 out of 4 CpG sites (P < 0.05 for all), respectively. This hypomethylation in CpG2 and CpG4 sites showed a reverse correlation to changes in plasma EPA concentration (r = -0.25, P = 0.045; and r = -0.26, P = 0.041, respectively), but not to changes in plasma DHA concentration, and were not related to apolipoprotein E-4 allele frequency.Conclusion: Supplementation with n-3 FA for 6 mo was associated with global DNA hypomethylation in PBLs. Our data may be of importance in measuring various effects of marine oils, including gene expression, in patients with AD and in other patients taking n-3 FA supplements. This trial was registered at clinicaltrials.gov as NCT00211159.
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| 26. |
- Titova, Olga E, et al.
(författare)
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Anorexia nervosa is linked to reduced brain structure in reward and somatosensory regions : a meta-analysis of VBM studies
- 2013
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Ingår i: BMC Psychiatry. - 1471-244X. ; 13:1, s. 110-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDStructural imaging studies demonstrate brain tissue abnormalities in eating disorders, yet a quantitative analysis has not been done.METHODSIn global and regional meta-analyses of 9 voxel-based morphometry (VBM) studies, with a total of 228 eating disorder participants (currently ill with anorexia nervosa), and 240 age-matched healthy controls, we compare brain volumes using global and regional analyses.RESULTSAnorexia nervosa (AN) patients have global reductions in gray (effect size = -0.66) and white matter (effect size = -0.74) and increased cerebrospinal fluid (effect size = 0.98) and have regional decreases in left hypothalamus, left inferior parietal lobe, right lentiform nucleus and right caudate, and no significant increases. No significant difference in hemispheric lateralization was found.CONCLUSIONSGlobal and regional meta-analyses suggest that excessive restrained eating as found in those with anorexia nervosa coincides with structural brain changes analogous to clinical symptoms.
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| 27. |
- Tofiq, avin, 1996-, et al.
(författare)
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Effects of Peroral Omega-3 Fatty Acid Supplementation on Cerebrospinal Fluid Biomarkers in Patients with Alzheimer's Disease : A Randomized Controlled Trial-The OmegAD Study
- 2021
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 83:3, s. 1291-1301
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Studies have suggested a connection between a decrease in the levels of polyunsaturated fatty acids (PUFAs) and Alzheimer's disease (AD). We aimed to assess the effect of supplementation with omega-3 fatty acids (n-3 FAs) on biomarkers analyzed in the cerebrospinal fluid (CSF) of patients diagnosed with AD.OBJECTIVE: To investigate the effects of daily supplementation with 2.3 g of PUFAs in AD patients on the biomarkers in CSF described below. We also explored the possible correlation between these biomarkers and the performance in the cognitive test Mini-Mental State Examination (MMSE).METHODS: Thirty-three patients diagnosed with AD were randomized to either treatment with a daily intake of 2.3 g of n-3 FAs (n = 18) or placebo (n = 15). CSF samples were collected at baseline and after six months of treatment, and the following biomarkers were analyzed: Aβ 38, Aβ 40, Aβ 42, t-tau, p-tau, neurofilament light (NfL), chitinase-3-like protein 1 (YKL-40), acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), soluble IL-1 receptor type II (sIL-1RII), and IL-6.RESULTS: There were no significant differences between the groups concerning the level of the different biomarkers in the CSF at baseline. Within the treatment group, there was a small but significant increase in both YKL-40 (p = 0.04) and NfL (p = 0.03), while the other CSF biomarkers remained stable.CONCLUSION: Supplementation with n-3 FAs had a statistically significant effect on NfL and YKL-40, resulting in an increase of both biomarkers, indicating a possible increase of inflammatory response and axonal damage. This increase in biomarkers did not correlate with MMSE score.
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| 28. |
- Vedin, Inger, et al.
(författare)
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Reduced prostaglandin F-2 alpha release from blood mononuclear leukocytes after oral supplementation of omega 3 fatty acids : the OmegAD study
- 2010
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Ingår i: Journal of Lipid Research. - : American Society for Biochemistry and Molecular Biology. - 0022-2275 .- 1539-7262. ; 51:5, s. 1179-1185
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Tidskriftsartikel (refereegranskat)abstract
- Omega-3 fatty acids, e. g., dokosahexaenoic acid (DHA) and eikosapentaenoic acid (EPA), ameliorate inflammatory reactions by various mechanisms, but the role of prostaglandins remains unclear. Our aim was to determine if dietary supplementation with a DHA-rich fish oil influenced the release of PGF(2 alpha) from peripheral blood mononuclear cells (PBMC). In the OmegAD study, 174 Alzheimer disease patients received either 1.7 g DHA plus 0.6 g EPA or a placebo daily for six months. PBMCs from the 21 ( 9 on fish oil and 12 on placebo) first-randomized patients were stimulated with either lipopolysaccharide (LPS) or phytohemagglutinin (PHA) before and after 6 months. Our results showed that plasma concentrations of DHA and EPA increased significantly at 6 months in the omega-3 group. PGF(2 alpha) release from LPS- ( but not from PHA-) stimulated PBMC was significantly diminished in this group; no change was noted in the placebo group. PGF(2 alpha) changes correlated inversely with changes in plasma DHA and EPA. Decreased IL-6 and IL-1(beta) levels correlated with decreased PGF(2 alpha) levels. The stimulus-specific PGF(2 alpha) release from PBMC after 6 months of oral supplementation with the DHA-rich fish oil might be one event related to reduced inflammatory reactions associated with omega-3 fatty acid intake.
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| 29. |
- Wang, Xiuzhe, et al.
(författare)
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Effects of n-3 FA supplementation on the release of proresolving lipid mediators by blood mononuclear cells : the OmegAD study
- 2015
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Ingår i: Journal of Lipid Research. - : American Society for Biochemistry and Molecular Biology. - 0022-2275 .- 1539-7262. ; 56:3, s. 674-681
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Tidskriftsartikel (refereegranskat)abstract
- Specialized proresolving mediators (SPMs) induce resolution of inflammation. SPMs are derivatives of n-3 and n-6 PUFAs and may mediate their beneficial effects. It is unknown whether supplementation with PUFAs influences the production of SPMs. Alzheimer's disease (AD) is associated with brain inflammation and reduced levels of SPMs. The OmegAD study is a randomized, double-blind, and placebo-controlled clinical trial on AD patients, in which placebo or a supplement of 1.7 g DHA and 0.6 g EPA was taken daily for 6 months. Plasma levels of arachidonic acid decreased, and DHA and EPA levels increased after 6 months of n-3 FA treatment. Peripheral blood mononuclear cells (PBMCs) were obtained before and after the trial. Analysis of the culture medium of PBMCs incubated with amyloid-β 1-40 showed unchanged levels of the SPMs lipoxin A4 and resolvin D1 in the group supplemented with n-3 FAs, whereas a decrease was seen in the placebo group. The changes in SPMs showed correspondence to cognitive changes. Changes in the levels of SPMs were positively correlated to changes in transthyretin. We conclude that supplementation with n-3 PUFAs for 6 months prevented a reduction in SPMs released from PBMCs of AD patients, which was associated with changes in cognitive function.
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| 30. |
- Wlad, Magdalena, et al.
(författare)
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Dorsal anterior cingulate cortex activity during cognitive challenge in social anxiety disorder
- 2023
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Ingår i: Behavioural Brain Research. - : Elsevier. - 0166-4328 .- 1872-7549. ; 442
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Tidskriftsartikel (refereegranskat)abstract
- Background: Social anxiety disorder (SAD) is associated with aberrant emotional information processing while little is known about non-emotional cognitive processing biases. The dorsal anterior cingulate cortex (dACC) has been implicated in SAD neuropathology and is activated both by emotional and non-affective cognitive challenges like the Multisource Interference Task (MSIT).Methods: Here, we used fMRI to compare dACC activity and test performance during MSIT in 69 SAD patients and 38 healthy controls. In addition to patient-control comparisons, we examined whether neural activity in the dACC correlated with social anxiety, trait anxiety or depression levels.Results: The MSIT activated the dACC as expected but with no differences in task performance or neural reactivity between SAD patients and controls. There were no significant correlations between dACC activity and social or trait anxiety symptom severity. In patients, there was a significant negative correlation between dACC activity and depressive symptoms.Conclusions: In absence of affective challenge, we found no disorder-related cognitive profile in SAD patients since neither MSIT task performance nor dACC neural activity deviated in patients relative to controls.
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