| 1. |
- Dennis, Martin, et al.
(författare)
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Effects of fluoxetine on functional outcomes after acute stroke (FOCUS) : a pragmatic, double-blind, randomised, controlled trial
- 2019
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 393:10168, s. 265-274
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Tidskriftsartikel (refereegranskat)abstract
- Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects.Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762.Findings Between Sept 10,2012, and March 31,2017,3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99.3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0.951 [95% CI 0.839-1.079]; p=0.439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13.43%] patients vs 269 [17.21%]; difference 3.78% [95% CI 1.26-6.30]; p=0.0033), but they had more bone fractures (45 [2.88%] vs 23 [1.47%]; difference 1.41% [95% CI 0.38-2.43]; p=0.0070). There were no significant differences in any other event at 6 or 12 months.Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function.
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| 2. |
- Errandonea, Daniel, et al.
(författare)
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Experimental and theoretical confirmation of an orthorhombic phase transition in niobium at high pressure and temperature
- 2020
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Ingår i: COMMUNICATIONS MATERIALS. - : Springer Nature. - 2662-4443. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- Compared to other body-centered cubic (bcc) transition metals, Nb has been the subject of fewer compression studies and there are still aspects of its phase diagram which are unclear. Here, we report a combined theoretical and experimental study of Nb under high pressure and temperature. We present the results of static laser-heated diamond anvil cell experiments up to 120 GPa using synchrotron-based fast x-ray diffraction combined with ab initio quantum molecular dynamics simulations. The melting curve of Nb is determined and evidence for a solid-solid phase transformation in Nb with increasing temperature is found. The high-temperature phase of Nb is orthorhombic Pnma. The bcc-Pnma transition is clearly seen in the experimental data on the Nb principal Hugoniot. The bcc-Pnma coexistence observed in our experiments is explained. Agreement between the measured and calculated melting curves is very good except at 40-60 GPa where three experimental points lie below the theoretical melting curve by 250 K (or 7%); a possible explanation is given. The study of materials under extreme conditions can reveal interesting physics in diverse areas such as condensed matter and geophysics. Here, the authors investigate experimentally and theoretically the high pressure-high temperature phase diagram of niobium revealing a previously unobserved phase transition from body-centered cubic to orthorhombic phase.
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| 3. |
- Forsberg, Kalle, et al.
(författare)
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A Systematic Review Of Erythropoietin In Experimental Stroke
- 2009
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Ingår i: Stroke. - 0039-2499. ; 40:4
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Konferensbidrag (refereegranskat)abstract
- Introduction: Erythropoietin (EPO), a hematopoietic growth factor, has promise as a neuroprotectant in animal models of ischemic stroke. EPO is thought not only to protect neurons from cell death, but also is hypothesized to promote regeneration post stroke. Here we report a systematic review and meta-analysis of the published animal data characterizing the efficacy of EPO. Methods We conducted a systematic review and random effects weighted mean difference meta-analysis only including studies describing the efficacy of EPO in models of focal cerebral ischemia. Primary outcomes were infarct size and neurobehavioral score. A stratified analysis to identify the impact of elements of study quality and design was also conducted. Results Only 11 of 943 studies met our inclusion criteria. Infarct size was reported in 15 experiments using 191 animals. Neurobehavioral score was reported in 16 experiments using 287 animals. EPO improved infarct size by 30.5% (95%Cl 19.3%-41.7%) and neurobehavioral score by 37.4% (31.2– 43.7%). For infarct size, EPO was least effective in thrombotic models of ischemia, (16% versus to 44.8% and 24% in permanent and transient models of ischemia respectively, X2 =1.47 x 10–04). Using a scoring system derived from the STAIR criteria,study quality was modest with a median score of 4 out of 11 for both outcomes. Studies that randomized to treatment group reported smaller infarct sizes compared to those that did not (18.0% versus 44.8%, n=113 versus 78 animals, X2 = 3.4 x 10–05). Studies that blinded assessment of outcome also showed a smaller improvement in neurobehavioral score (31.1% versus 41.6%, n=107 versus 167, X2 = 8.9 x 10–4). Only 11.7% of the animals in the total dataset had a co-morbidity common to human stroke (hypertension) and this co-morbidity was only reported for neurobehavioral comparisons, not for infarct size. Blinded induction of ischemia was reported in 2 experiments (21.5% of animals) measuring infarct volume. Conclusions: Aggregation of the animal data for EPO in ischemic stroke indicates mean effect sizes of 30.5% and 37.4% for infarct volume and neurobehavioral score respectively. However, when the impact of common sources of bias are considered these effect sizes fall suggesting we are overestimating its potential benefit. As common human co-morbidities may reduce therapeutic efficacy, broader testing to delineate the range of circumstances in which EPO works would be beneficial before clinical trialing.
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| 4. |
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| 5. |
- Gustafsson, Oscar, 1973-, et al.
(författare)
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Simplified Design of Constant Coefficient Multipliers
- 2006
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Ingår i: Circuits, systems, and signal processing. - : Springer Science and Business Media LLC. - 0278-081X .- 1531-5878. ; 25:2, s. 225-251
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Tidskriftsartikel (refereegranskat)abstract
- In many digital signal processing algorithms, e.g., linear transforms and digital filters, the multiplier coefficients are constant. Hence, it is possible to implement the multiplier using shifts, adders, and subtracters. In this work two approaches to realize constant coefficient multiplication with few adders and subtracters are presented. The first yields optimal results, i.e., a minimum number of adders and subtracters, but requires an exhaustive search. Compared with previous optimal approaches, redundancies in the exhaustive search cause the search time to be drastically decreased. The second is a heuristic approach based on signed-digit representation and subexpression sharing. The results for the heuristic are worse in only approximately 1% of all coefficients up to 19 bits. However, the optimal approach results in several different optimal realizations, from which it is possible to pick the best one based on other criteria. Relations between the number of adders, possible coefficients, and number of cascaded adders are presented, as well as exact equations for the number of required full and half adder cells. The results show that the number of adders and subtracters decreases on average 25% for 19-bit coefficients compared with the canonic signed-digit representation.
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| 6. |
- Jerndal, Mikael, et al.
(författare)
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A systematic review and meta-analysis of erythropoietin in experimental stroke.
- 2010
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Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016. ; 30:5, s. 961-8
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Forskningsöversikt (refereegranskat)abstract
- Erythropoietin (EPO) has shown promise as a neuroprotectant in animal models of ischemic stroke. EPO is thought not only to protect neurons from cell death, but also to promote regeneration after stroke. Here, we report a systematic review and meta-analysis of the efficacy of EPO in animal models of focal cerebral ischemia. Primary outcomes were infarct size and neurobehavioral outcome. Nineteen studies involving 346 animals for infarct size and 425 animals for neurobehavioral outcome met our inclusion criteria. Erythropoietin improved infarct size by 30.0% (95% CI: 21.3 to 38.8) and neurobehavioral outcome by 39.8% (33.7 to 45.9). Studies that randomized to treatment group or that blinded assessment of outcome showed lower efficacy. Erythropoietin was tested in animals with hypertension in no studies reporting infarct size and in 7.5% of the animals reporting neurobehavioral outcome. These findings show efficacy for EPO in experimental stroke, but when the impact of common sources of bias are considered, this efficacy falls, suggesting we may be overestimating its potential benefit. As common human co-morbidities may reduce therapeutic efficacy, broader testing to delineate the range of circumstances in which EPO works best would be beneficial.
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| 7. |
- Macleod, Malcolm R., et al.
(författare)
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Hypothermia for Stroke: call to action 2010
- 2010
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Ingår i: International Journal of Stroke. - : SAGE Publications. - 1747-4949 .- 1747-4930. ; 5:6, s. 489-492
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Tidskriftsartikel (refereegranskat)abstract
- The European Hypothermia Stroke Research Workshop was held in January 2010, in response to the alarming prospects of a significant increase of stroke expected in the coming years globally. Considering that a minority of patients (around 10%) are currently eligible for thrombolytic treatment, there is a need for an efficacious, cost-effective novel therapy that can be implemented broadly within European health care systems. Accordingly, the primary objective of the workshop was the definition of a research agenda aiming to assess the therapeutic benefits of hypothermia in patients with acute ischaemic stroke. The meeting was organised by the European Stroke Research Network for Hypothermia(EuroHyp) and attended by the representatives of World Stroke Organisation, European Stroke Organisation, Stroke Alliance for Europe, Society for Cryobiology and other organisations - specifically the European Space Agency, and small-and medium-sized enterprises based in EU member states. The participants adopted the 'Hypothermia for Stroke - Call to Action 2010', a declaration specifying the priorities for hypothermia research in acute ischaemic stroke. The research programme outlined - a clinical study programme designed to identify and validate therapeutic cooling as a novel treatment providing benefit to a large number of stroke patients-contains a well-integrated series of Phase II studies aiming to refine the intervention (depth, duration, and mode of cooling; antishivering strategy; patient selection) and a pivotal Phase III clinical trial. The proposed integrated Phase II and III clinical study programme would test the effectiveness of this optimised intervention, and would allow the development of evidence-based Clinical Practice Guidelines describing the optimal use of therapeutic hypothermia as a treatment strategy for stroke.
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| 8. |
- Macleod, Malcolm R, et al.
(författare)
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Mineralocorticoid receptor expression and increased survival following neuronal injury
- 2003
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Ingår i: European Journal of Neuroscience. - : Wiley. - 0953-816X .- 1460-9568. ; 17:8, s. 1549-1555
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Tidskriftsartikel (refereegranskat)abstract
- Glucocorticoids, acting via the mineralocorticoid receptor, are required for granule neuronal survival in the rat dentate gyrus. Whether this mineralocorticoid receptor-mediated neuroprotective effect has more general applicability is unknown. Here we report increased mineralocorticoid receptor expression in rat hippocampal and cortical neurons exposed in vitro to low levels of staurosporine and in rat hippocampal pyramidal neurons exposed in vivo to hypothermic transient global ischaemia. In both the cell culture system and the in vivo system increased mineralocorticoid receptor expression is associated with increased neuronal survival, and this increase is reversed by mineralocorticoid receptor antagonism. Modulation of mineralocorticoid receptor gene expression may therefore be an important target for reduction of brain injury in conditions caused by cerebral ischaemia including brain damage following cardiac arrest and stroke.
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| 9. |
- Munro, Keith, et al.
(författare)
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The high-pressure, high-temperature phase diagram of cerium
- 2020
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Ingår i: Journal of Physics. - : Institute of Physics (IOP). - 0953-8984 .- 1361-648X. ; 32:33
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Tidskriftsartikel (refereegranskat)abstract
- We present an experimental study of the high-pressure, high-temperature behaviour of cerium up to ~22 GPa and 820 K using angle-dispersive x-ray diffraction and external resistive heating. Studies above 820 K were prevented by chemical reactions between the samples and the diamond anvils of the pressure cells. We unambiguously measure the stability region of the orthorhombic oC4 phase and find it reaches its apex at 7.1 GPa and 650 K. We locate the α-cF4–oC4–tI2 triple point at 6.1 GPa and 640 K, 1 GPa below the location of the apex of the oC4 phase, and 1–2 GPa lower than previously reported. We find the α-cF4 → tI2 phase boundary to have a positive gradient of 280 K (GPa)−1, less steep than the 670 K (GPa)−1 reported previously, and find the oC4 → tI2 phase boundary to lie at higher temperatures than previously found. We also find variations as large as 2–3 GPa in the transition pressures at which the oC4 → tI2 transition takes place at a given temperature, the reasons for which remain unclear. Finally, we find no evidence that the α-cF4 → tI2 is not second order at all temperatures up to 820 K.
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| 10. |
- Olai, H, et al.
(författare)
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Protocol for meta-analysis of temperature reduction in animal models of cardiac arrest
- 2016
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Ingår i: Evidence-based preclinical medicine. - : Wiley. - 2054-703X. ; 3:1, s. 4-11
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Tidskriftsartikel (refereegranskat)abstract
- Targeted temperature management (TTM) of 32-34 °C has been the standard treatment for out-of-hospital cardiac arrest since clinical trials in 2002 showed benefits to survival and neurological outcome. Recently, this treatment has been challenged by another clinical trial showing no difference in outcome between TTM of 33 °C and 36 °C. This protocol describes the methodology for a meta-analysis detailing temperature-reducing interventions to treat global ischaemia in animal models. By combining relevant data sets in the literature, we will explore the experimental evidence for TTM. Our aims are to explain possible translational gaps and provide methodological considerations for future experimental research and clinical trials.
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