| 61. |
- Karshikoff, B., et al.
(författare)
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LPS increases pain sensitivity by decreased pain inhibition and increased insular activation
- 2015
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 49, s. e1-e1
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Tidskriftsartikel (refereegranskat)abstract
- We have shown that women are more prone to developing LPS-induced pain sensitivity than men, and that the descending endogenous pain inhibition is disrupted in women during experimental systemic inflammation. The aim of the present study was to investigate some of the central neural mechanisms underlying our previous findings. 51 participants (29 women) were injected with 0.6 ng/kg LPS or saline and went through a thumb-pressure pain fMRI paradigm 2 h after injection. As hypothesized, the subjects injected with LPS had decreased activity in the ventromedial prefrontal cortex and rostral anterior cingulate cortex (rACC), areas involved in descending pain inhibition. In addition, the LPS group had higher activity in the anterior insula, an area involved in medial/affective pain processing and interoception. These effects were not sex dependent. However, the male participants had overall stronger descending pain inhibition, reflected as a stronger rACC activity compared to women. It is possible that the more robust activation of descending pain inhibition rendered the men more resistant to the immune provocation, which may explain previously seen sex differences in LPS-induced pain sensitivity. Our findings give an indication to how the pain matrix is affected during a sickness response. The results strengthen the proposed link between systemic inflammation and weakened pain regulation in chronic pain disorders, and offers a possible mechanism underlying the female predominance in chronic pain disorders.
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| 62. |
- Karshikoff, B., et al.
(författare)
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Modality and sex differences in pain sensitivity during human endotoxemia
- 2014
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 46, s. 35-43
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Tidskriftsartikel (refereegranskat)abstract
- Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, and has been proposed to be central in clinical pain conditions. Women are overrepresented in many chronic pain conditions, but experimental studies on sex differences in pain regulation during systemic inflammation are still scarce. In two randomized and double blind placebo controlled experiments, we used low doses of lipopolysaccharide (LPS) as an experimental model of systemic inflammation. The first study employed 0.8ng/kg LPS in a within-subject design of 8 individuals (1 woman), and the second study 0.6ng/kg LPS in a between-subject design of 52 participants (29 women). We investigated the effect on (a) pressure, heat, and cold pain thresholds, (b) suprathreshold noxious heat and cold sensitivity, and (c) conditioned pain modulation (CPM), and differences between men and women. LPS induced significantly lower pressure pain thresholds as compared to placebo (mean change with the 0.8ng/kg dose being -64±30kPa P=.04; with the 0.6ng/kg dose -58±55kPa, P<.01, compared to before injection), whereas heat and cold pain thresholds remained unaffected (P's>.70). Suprathreshold noxious pain was not affected by LPS in men (P's⩾.15). However, LPS made women rated suprathreshold noxious heat stimuli as more painful (P=.01), and showed a tendency to rate noxious cold pain as more painful (P=.06) as compared to placebo. Furthermore, LPS impaired conditioned pain modulation, a measure of endogenous pain inhibition, but this effect was also restricted to women (P<.01, for men P=.27). Pain sensitivity correlated positively with plasma IL-6 and IL-8 levels. The results show that inflammation more strongly affects deep pain, rather than cutaneous pain, and suggest that women's pain perception and modulation is more sensitive to immune activation than men's.
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| 63. |
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| 64. |
- Karshikoff, Bianka, et al.
(författare)
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Why sickness hurts : A central mechanism for pain induced by peripheral inflammation
- 2016
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 57, s. 38-46
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Tidskriftsartikel (refereegranskat)abstract
- Low-grade systemic inflammation has been implicated in chronic pain, as well as in comorbid diseases like depression and fatigue. We have previously shown that women's pain perception and regulation is more affected by systemic inflammation than that of men. Here we investigated the neural substrates underlying these effects using an fMRI paradigm previously employed in a clinical population. Fifty-one participants (29 women) were injected with 0.6ng/kg lipopolysaccharide (LPS) or saline to induce a peripheral inflammatory response. The subjects were then tested with a pressure pain fMRI paradigm designed to capture descending pain inhibitory activity 2h after injection, and blood was sampled for cytokine analysis. The subjects injected with LPS became more pain sensitive compared to the placebo group, and the heightened pain sensitivity was paralleled by decreased activity in the ventrolateral prefrontal cortex and the rostral anterior cingulate cortex (rACC) compared to placebo; areas involved in descending pain regulation. The LPS group also had higher activity in the anterior insular cortex, an area underpinning affective and interoceptive pain processing. Women displayed overall less pain-evoked rACC activity compared to men, which may have rendered women less resilient to immune provocation, possibly explaining sex differences in LPS-induced pain sensitivity. Our findings elucidate the pain-related brain circuits affected by experimental peripheral inflammation, strengthening the theoretical link between systemic inflammation and weakened pain regulation in chronic pain disorders. The results further suggest a possible mechanism underlying the female predominance in many chronic pain disorders.
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| 65. |
- Kemani, M. K., et al.
(författare)
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Processes of change in Acceptance and Commitment Therapy and Applied Relaxation for long-standing pain
- 2016
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Ingår i: European Journal of Pain. - : Wiley. - 1090-3801 .- 1532-2149. ; 20:4, s. 521-531
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The utility of cognitive behavioural (CB) interventions for chronic pain has been supported in numerous studies. This includes Acceptance and Commitment Therapy (ACT), which has gained increased empirical support. Previous research suggests that improvements in pain catastrophizing and psychological inflexibility are related to improvements in treatment outcome in this type of treatment. Although a few studies have evaluated processes of change in CB-interventions, there is a particular need for mediation analyses that use multiple assessments to model change in mediators and outcome over time, and that incorporate the specified timeline between mediator and outcome in the data analytic model.METHODS: This study used session-to-session assessments to evaluate if psychological inflexibility, catastrophizing, and pain intensity mediated the effects of treatment on pain interference. Analyses were based on data from a previously conducted randomized controlled trial (n = 60) evaluating the efficacy of ACT and Applied Relaxation (AR). A moderated mediation model based on linear mixed models was used to analyse the data.RESULTS: Neither catastrophizing nor pain intensity mediated changes in pain interference for any of the treatments. In contrast, psychological inflexibility mediated effects on outcome in ACT but not in AR.CONCLUSIONS: Results add to previous findings illustrating the role of psychological inflexibility as a mediator in ACT.
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| 66. |
- Koskuvi, Marja, et al.
(författare)
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Lower complement C1q levels in first-episode psychosis and in schizophrenia
- 2024
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Ingår i: Brain, Behavior, and Immunity. - : Elsevier. - 0889-1591 .- 1090-2139. ; 117, s. 313-319
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Tidskriftsartikel (refereegranskat)abstract
- Recent evidence has implicated complement component (C) 4A in excessive elimination of synapses in schizophrenia. C4A is believed to contribute to physiological synapse removal through signaling within the C1q initiated classical activation axis of the complement system. So far, a potential involvement of C1q in the pathophysiology of schizophrenia remains unclear. In this study, we first utilized large-scale gene expression datasets (n = 586 patients with schizophrenia and n = 986 controls) to observe lower C1QA mRNA expression in prefrontal cortex tissue of individuals with schizophrenia (P = 4.8x10-05), while C1QA seeded co-expression networks displayed no enrichment for schizophrenia risk variants beyond C4A. We then used targeted liquid chromatography-mass spectrometry (LS-MS) to measure cerebrospinal fluid (CSF) levels of C1qA in 113 individuals with first-episode psychosis (FEP), among which 66 individuals was later diagnosed with schizophrenia, and 87 healthy controls. CSF concentrations of C1qA were lower in individuals diagnosed with FEP (P = 0.0001), also after removing subjects with a short-term prescription of an antipsychotic agent (P = 0.0005). We conclude that C1q mRNA and protein levels are lower in schizophrenia and that further experimental studies are needed to understand the functional implications.
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| 67. |
- Lasselin, Julie, 1986-, et al.
(författare)
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Advantages and methodological considerations of experimental endotoxemia in humans : Towards a standardized procedure for its application in PNI
- 2021
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 98, s. 28-29
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Tidskriftsartikel (refereegranskat)abstract
- Experimental endotoxemia is now recognized as a highly useful tool to better understand inflammation-induced behavioral changes and their underlying mechanisms. Advantages of this model include the ability to assess the causal effects of inflammatory mediators in a safe and highly controlled context, to assess the homeostatic (regulatory) response to inflammatory mediators within a relatively short time frame, as well as to translate findings between animals and humans. Various groups have used this model in humans, leading to variations in experimental procedures that likely affect the studied outcomes. As the use of experimental endotoxemia develops, there is a need of a standardization of the procedure to make the best use of this model in PNI. The participants in this discussion group are all leaders in the use of the model of experimental endotoxemia in humans in PNI, and will discuss the advantages, limitations, clinical relevance, and methodological considerations of this model. This discussion is intended as a first step towards developing common and optimized procedures for the use of this model across PNI groups.
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| 68. |
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| 69. |
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| 70. |
- Lekander, Jon R. G. M.
(författare)
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How do institutional pension managers consider real estate : A perspective from Sweden and Finland
- 2017
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Ingår i: Journal of Property Investment & Finance. - : Emerald Group Publishing Limited. - 1463-578X .- 1470-2002. ; 35:1, s. 26-43
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The asset allocation decision for a pension portfolio needs to consider several, sometimes conflicting, aspects. Most pension managers use models and processes that are developed for the traditional asset classes for analyzing this problem. The purpose of this paper is to investigate how real estate is included in this process, for what purpose and how the real estate portfolio is constructed. Design/methodology/approach: Seven individuals responsible for the asset allocation process were interviewed, and their responses were analyzed with regards to organizational options and their real estate strategy. Findings: It was found that real estate is held for three different purposes, risk diversification, inflation hedging/liability matching and return enhancement and that the allocation has increased over time. The allocation strategy has evolved at least in part in conjuncture with the organizational structure set in place to overcome real estate market frictions. Research limitations/implications: The interviews were geographically limited to pension funds domiciled in Sweden and Finland. Practical implications: It is concluded that the organizational capabilities of the pension fund of handling real estate is an important consideration for the ensuing real estate portfolio. Originality/value: The originality of this paper lies in that it is based on interviews with individuals who are responsible for the asset allocation decision at large pension funds. The findings of the paper identify areas of interest for future research.
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