| 41. |
- 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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| 42. |
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| 43. |
- Stockfelt, Leo, 1981, et al.
(författare)
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Long-Term Exposure to Particulate Air Pollution, Black Carbon, and Their Source Components in Relation to Ischemic Heart Disease and Stroke
- 2019
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Ingår i: Journal of Environmental Health Perspectives. - Durham : National Institute of Environmental Health Sciences. - 0091-6765 .- 1552-9924. ; 127:10
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Long-term exposure to particulate matter (PM) in ambient air has been associated with cardiovascular mortality, but few studies have considered incident disease in relation to PM from different sources.OBJECTIVES: We aimed to study associations between long-term exposure to different types of PM and sources, and incident ischemic heart disease (IHD) and stroke in three Swedish cities.METHODS: ), and black carbon (BC) from road wear, traffic exhaust, residential heating, and other sources in Gothenburg, Stockholm, and Umeå. Registry data for participants from four cohorts were used to obtain incidence of IHD and stroke for first hospitalization or death. We constructed time windows of exposure for same-year, 1- to 5-y, and 6- to 10-y averages preceding incidence from annual averages at residential addresses. Risk estimates were based on random effects meta-analyses of cohort-specific Cox proportional hazard models.RESULTS: exposure from residential heating.DISCUSSION: Few consistent associations were observed between different particulate components and IHD or stroke. However, long-term residential exposure to locally emitted BC from traffic exhaust was associated with stroke incidence. The comparatively low exposure levels may have contributed to the paucity of associations.
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| 44. |
- Stomrud, Erik, et al.
(författare)
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CSF biomarkers correlate with cerebral blood flow on SPECT in healthy elderly.
- 2012
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 33:2-3, s. 156-63
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Tidskriftsartikel (refereegranskat)abstract
- The preclinical patterns of biological markers for Alzheimer's disease (AD) in vivo need further exploration. The aim of this study was therefore to investigate CSF biomarkers, regional cerebral blood flow (rCBF) and cognitive performance in cognitively healthy older individuals.
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| 45. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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Risk factors for subarachnoid haemorrhage : a nationwide cohort of 950 000 adults
- 2019
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Ingår i: International Journal of Epidemiology. - : Oxford University Press. - 0300-5771 .- 1464-3685. ; 48:6, s. 2018-2025
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Subarachnoid haemorrhage (SAH) is a devastating disease, with high mortality rate and substantial disability among survivors. Its causes are poorly understood. We aimed to investigate risk factors for SAH using a novel nationwide cohort consortium.METHODS: We obtained individual participant data of 949 683 persons (330 334 women) between 25 and 90 years old, with no history of SAH at baseline, from 21 population-based cohorts. Outcomes were obtained from the Swedish Patient and Causes of Death Registries.RESULTS: During 13 704 959 person-years of follow-up, 2659 cases of first-ever fatal or non-fatal SAH occurred, with an age-standardized incidence rate of 9.0 [95% confidence interval (CI) (7.4-10.6)/100 000 person-years] in men and 13.8 [(11.4-16.2)/100 000 person-years] in women. The incidence rate increased exponentially with higher age. In multivariable-adjusted Poisson models, marked sex interactions for current smoking and body mass index (BMI) were observed. Current smoking conferred a rate ratio (RR) of 2.24 (95% CI 1.95-2.57) in women and 1.62 (1.47-1.79) in men. One standard deviation higher BMI was associated with an RR of 0.86 (0.81-0.92) in women and 1.02 (0.96-1.08) in men. Higher blood pressure and lower education level were also associated with higher risk of SAH.CONCLUSIONS: The risk of SAH is 45% higher in women than in men, with substantial sex differences in risk factor strengths. In particular, a markedly stronger adverse effect of smoking in women may motivate targeted public health initiatives.
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| 46. |
- Svensson, Anna C., et al.
(författare)
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Residential area and physical activity : A multi-level study of 68,000 adults in Stockholm County
- 2017
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 45:1, s. 25-32
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To determine whether there are systematic differences in physical activity between residential areas after extensive control for sociodemographic factors at the individual level. Methods: Multi-level regressions of walking/bicycling, sedentary activities, household work and exercise were carried out in a representative sample of 68,303 adults in 39 residential areas in Stockholm County, first adjusting at the individual level for country of birth, sex, age, education, occupational class and income. The type of housing was then considered at the individual level or, for walking/bicycling and exercise, at both the individual and area levels (as a measure of area density). Results: After adjustment for sociodemographic factors, differences between residential areas remained in walking/bicycling, corresponding to 0.27 SD, or 50 min/week between the most and least active areas. Forty per cent of this difference could be explained by the type of housing at the area level. For sedentary activities and household work, respectively, much of the variation that remained after adjustment for sociodemographic factors was, in turn, explained by the type of housing at the individual level, leaving a difference of 0.16 SD (80 min/week) and 0.13 SD (60 min/week), respectively. For exercise, the corresponding difference was 0.11 SD (11 min/week, not sensitive to housing). Conclusions: Area level factors may influence walking/bicycling. High area density was associated with more activity. However, high density also comes with a type of housing (apartments) that is associated with less household work and, surprisingly, more sedentary activities, introducing a challenging trade-off. The differences in exercise were smaller than for all other types of activities.
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| 47. |
- Såmark-Roth, Anton, et al.
(författare)
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Spectroscopy along flerovium decay chains: Discovery of 280Ds and an excited state in 282Cn
- 2021
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Ingår i: Physical Review Letters. - 1079-7114. ; 126:3
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Tidskriftsartikel (refereegranskat)abstract
- A nuclear spectroscopy experiment was conducted to study α-decay chains stemming from isotopes of flerovium (element Z=114). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions 48Ca+242Pu and 48Ca+244Pu provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to 286Fl and 288Fl, respectively. A prompt coincidence between a 9.60(1)-MeV α-particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely 282Cn. Spectroscopy of 288Fl decay chains fixed Qα=10.06(1) MeV. In one case, a Qα=9.46(1)-MeV decay from 284Cn into 280Ds was observed, with 280Ds fissioning after only 518 μs. The impact of these findings, aggregated with existing data on decay chains of 286,288Fl, on the size of an anticipated shell gap at proton number Z=114 is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.
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| 48. |
- Tamm, Sandra, et al.
(författare)
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Evidence of fatigue, disordered sleep and peripheral inflammation, but not increased brain TSPO expression, in seasonal allergy : A [11C]PBR28 PET study
- 2018
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 68, s. 146-157
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Tidskriftsartikel (refereegranskat)abstract
- Allergy is associated with non-specific symptoms such as fatigue, sleep problems and impaired cognition. One explanation could be that the allergic inflammatory state includes activation of immune cells in the brain, but this hypothesis has not been tested in humans. The aim of the present study was therefore to investigate seasonal changes in the glial cell marker translocator protein (TSPO), and to relate this to peripheral inflammation, fatigue and sleep, in allergy. We examined 18 patients with severe seasonal allergy, and 13 healthy subjects in and out-of pollen season using positron emission tomography (n = 15/13) and the TSPO radioligand [11C]PBR28. In addition, TNF-α, IL-5, IL-6, IL-8 and IFN-γ were measured in peripheral blood, and subjective ratings of fatigue and sleepiness as well as objective and subjective sleep were investigated. No difference in levels of TSPO was seen between patients and healthy subjects, nor in relation to pollen season. However, allergic subjects displayed both increased fatigue, sleepiness and increased percentage of deep sleep, as well as increased levels of IL-5 and TNF-α during pollen season, compared to healthy subjects. Allergic subjects also had shorter total sleep time, regardless of season. In conclusion, allergic subjects are indicated to respond to allergen exposure during pollen season with a clear pattern of behavioral disruption and peripheral inflammatory activation, but not with changes in brain TSPO levels. This underscores a need for development and use of more specific markers to understand brain consequences of peripheral inflammation that will be applicable in human subjects.
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| 49. |
- Tamm, Sandra, et al.
(författare)
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Objective and Subjective Sleep in Rheumatoid Arthritis and Severe Seasonal Allergy : Preliminary Assessments of the Role of Sickness, Central and Peripheral Inflammation
- 2021
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Ingår i: Nature and Science of Sleep. - : Dove Medical Press. - 1179-1608. ; 13, s. 775-789
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Disturbed sleep in inflammatory disorders such as allergy and rheumatoid arthritis (RA) is common and may be directly or indirectly related to disease processes, but has not been well characterized in these patient groups, especially not with objective methods.Aim: The present study aimed to characterize objective and subjective sleep in patients with allergy or RA using sleep diaries, one-channel EEG and actigraphy. It also aimed to investigate if sleep measures were associated with central immune activation, assessed using translocator protein (TSPO) positron emission tomography, as well as cytokine markers of peripheral inflammation and disease-specific symptoms or general symptoms of sickness.Methods: In total, 18 patients with seasonal pollen allergy, 18 patients with RA and 26 healthy controls were included in the study. Allergy patients and matched controls were assessed twice, in and out of pollen season, and RA patients and controls were assessed once. Sleep was recorded for approximately 1 week at each occasion.Results: Patients with allergy had increased levels of slow-wave sleep during pollen season. In contrast, patients with RA had less SWS compared to healthy controls, while no differences were observed in sleep duration or subjective sleep quality. Across groups, neither proinflammatory cytokines, grey matter TSPO levels nor general sickness symptoms were associated with objective or subjective measures of sleep. Rhinitis, but not conjunctivitis, was correlated to worse subjective sleep and more slow wave sleep in allergy. Functional status, but not disease activity, predicted lower subjective sleep in RA.Conclusion: This study tentatively indicates that both patients with allergy and RA display sleep alterations but does not support inflammation as an independent predictor of the sleep disturbance across these patient groups.
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| 50. |
- Timm, Linda, et al.
(författare)
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"I Did Not Believe You Could Get Better" : Reversal of Diabetes Risk Through Dietary Changes in Older Persons with Prediabetes in Region Stockholm
- 2019
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Diabetes risk can be controlled and even reversed by making dietary changes. The aim of this study was to improve the understanding of how older persons with a high risk of developing Type 2 diabetes manage and relate to information about diabetes risk over a ten-year period. Fifteen qualitative interviews were conducted among participants from the Stockholm Diabetes Prevention Program (SDPP). The participants were asked to recall the health examinations conducted by the SDPP related to their prediabetes and to describe their experiences and potential changes related to diet and physical activity. Data were analyzed using qualitative content analysis. The main theme found was that T2D (type 2 diabetes) risk is not perceived as concrete enough to motivate lifestyle modifications, such as changing dietary patterns, without other external triggers. Diagnosis was recognized as a reason to modify diet, and social interactions were found to be important for managing behavior change. Diagnosis was also a contributing factor to lifestyle modification, while prognosis of risk was not associated with efforts to change habits. The results from this study suggest that the potential of reversing prediabetes needs to be highlighted and more clearly defined for older persons to serve as motivators for lifestyle modification.
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