260 research outputs found
Stig Dagerman
No full textSpecial feature issue on the Swedish author Stig Dagerman (1923-1954) with editorial by Anders Hallengren and original contributions by Johan Cullberg, Lotta Lotass, Tom Karlsson, Urban Forsgren, Bengt Söderhäll (2), Björn Ranelid, Bert Ekengren and Jöran Mjöberg along with texts by the author.</p
Conodonts in the Ordovician biostratigraphy of the British Isles: an update
No full textAn update of the conodont biostratugraphy is provided for the Ordovician
Blood-brain barrier permeability measured using dynamic contrast-enhanced magnetic resonance imaging: a validation study
No full textBlood–brain barrier (BBB) leakage can be measured using dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) as the influx constant Ki. To validate this method we compared measured Ki with biological expectations, namely (1) higher Ki in healthy individual grey matter (GM) versus white matter (WM), (2) GM/WM cerebral blood volume (CBV) ratio close to the histologically established GM/WM vascular density ratio, (3) higher Ki in visibly enhancing multiple sclerosis (MS) lesions versus MS normal appearing white matter (NAWM), and (4) higher Ki in MS NAWM versus healthy individual NAWM. We recruited 13 healthy individuals and 12 patients with MS and performed whole‐brain 3D DCE‐MRI at 3 T. Ki and CBV were calculated using Patlak modelling for manual regions of interest (ROI) and segmented tissue masks. Ki was higher in control GM versus WM (P = 0.001). CBV was higher in GM versus WM (P = 0.005, mean ratio 1.9). Ki was higher in visibly enhancing MS lesions versus MS NAWM (P = 0.002), and in MS NAWM versus controls (P = 0.014). Bland–Altman analysis showed no significant difference between ROI and segmentation methods (P = 0.638) and an intra‐class correlation coefficient showed moderate single measure consistency (0.610). Ki behaves as expected for a compound marker of permeability and surface area. The GM/WM CBV ratio measured by this technique is in agreement with the literature. This adds evidence to the validity of Ki measured by DCE‐MRI as a marker of overall BBB leakage
Cerebrospinal fluid neurofilament light chain in acute optic neuritis and its predictive ability of multiple sclerosis
No full textBackground: Studies on the capability of cerebrospinal fluid neurofilament light chain (cNfL) to predict multiple sclerosis (MS) conversion in clinically isolated syndromes have yielded varying results. Objectives: To expand our understanding of cNfL in optic neuritis (ON) and investigate whether incorporating cNfL into the 2017 McDonald criteria could accelerate the diagnosis of MS in patients with ON. Methods: cNfL was measured in diagnostic samples from 74 patients with verified ON. MS was diagnosed using the 2017 McDonald criteria with a minimum observation time of two years from ON onset. Results: 20.5% of 44 MS-converters did not fulfil the 2017 McDonald criteria at ON onset. A doubling of cNfL was associated with 207% (74%–514%) higher odds of MS (p = 0.00042, adjusted for age). Fulfilment of ≥ 1 MRI criterion for dissemination in space (DIS) and presence of brain contrast-enhancing lesions were associated with higher cNfL. Furthermore, cNfL correlated with inter-eye differences in retinal nerve fiber layer (RNFL) thickness (Spearman’s ρ = 0.46, p = 8 × 10
–5). Incorporating cNfL ≥ 906 pg/mL as a substitute for either dissemination in time or one MRI criterion for DIS increased the sensitivity (90.9% vs. 79.6%) and accuracy (91.9% vs. 87.8%), but also reduced the specificity (93.3% vs. 100%) of the 2017 McDonald criteria. Conclusion: cNfL was related to MS diagnostic parameters and the degree of RNFL swelling. Clinical use of cNfL may aid in identification of ON patients with increased risk of MS until larger studies have elaborated on the potential loss of specificity if used diagnostically.</p
Measurement variability of blood-brain barrier permeability using dynamic contrast-enhanced magnetic resonance imaging
No full textDynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is used to quantify the blood-brain barrier (BBB) permeability-surface area product. Serial measurements can indicate changes in BBB health, of interest to the study of normal physiology, neurological disease, and the effect of therapeutics. We performed a scan-rescan study to inform both sample size calculation for future studies and an appropriate reference change value for patient care. The final dataset included 28 healthy individuals (mean age 53.0, 82% female) scanned twice with mean interval 9.9 weeks. DCE-MRI was performed at 3T using a 3D gradient echo sequence with whole brain coverage, T1 mapping using variable flip angles, and a 16-minute dynamic sequence with a 3.2 second time resolution. Segmentation of white and grey matter (WM/GM) was performed using a 3D magnetization-prepared gradient echo image. The influx constant Ki was calculated using the Patlak method. The primary outcome was the within-subject coefficient of variation (CV) of Ki in both WM and GM. Ki values followed biological expectations in relation to known GM/WM differences in cerebral blood volume (CBV) and consequently vascular surface area.Subject-derived arterial input functions showed marked within-subject variability which were significantly reduced by using a venous input function (CV of area-under-the-curve 46 vs 12%, p < 0.001). Use of the venous input function significantly improved the CV of Ki in both WM (30 vs 59%, p < 0.001) and GM (21 vs 53%, p < 0.001). Further improvement was obtained using motion correction, scaling the venous input function by the artery, and using the median rather than the mean of individual voxel data. The final method gave CV of 27% and 17% in WM and GM respectively. No further improvement was obtained by replacing the subject-derived input function by one standard population input function. CV of Ki was shown to be highly sensitive to dynamic sequence duration, with shorter measurement periods giving marked deterioration especially in WM. In conclusion, measurement variability of 3D brain DCE-MRI is sensitive to analysis method and a large precision improvement is obtained using a venous input function
”Ja, denna stig är stigarnas stig” : Taoistiska influenser i Vilhelm Ekelunds verk
No full textMattias Aronsson, ”Ja, denna stig är stigarnas stig”. Taoistiska influenser i Vilhelm Ekelunds verk (“Yes, this path is the path of paths”. Taoist influence in the works of Vilhelm Ekelund) In this article I show how Taoist philosophy has influenced the Swedish poet, essayist and aphorist Vilhelm Ekelund. I note that the author mentions the Taoist philosophers Lao Tzu and Chuang Tzu and discusses their ideas on a couple of occasions in his later works (Atticism – Humanism, 1943; Plus salis–, 1945). Examples of such explicit influence can also be found in Ekelund’s private notebooks, posthumously published in two volumes: Hemkomst och flykt (1972) and Ur en scholaris’ verkstad (1974). I argue that Taoist philosophy implicitly influenced the Swedish author as early as the second part of the 1910’s – when he started to emphasize such principles as moderation, composure, dispassion and non-desire in his writing. I also discuss other important ideals which Ekelund shared with the Taoist philosophers, such as poverty, humility, simplicity and dishonour. Finally, I see a parallel in the anti-intellectual aspects of Taoist thinking and Ekelund’s use of the term misologi (misology), a word which often has positive connotations in his works. In Ekelund’s prose, as well as in the famous Taoist text Tao Te Ching, excessive intellectualism is frequently criticized
”Ja, denna stig är stigarnas stig” [Elektronisk resurs] : Taoistiska influenser i Vilhelm Ekelunds verk
No full textMattias Aronsson, ”Ja, denna stig är stigarnas stig”. Taoistiska influenser i Vilhelm Ekelunds verk (“Yes, this path is the path of paths”. Taoist influence in the works of Vilhelm Ekelund) In this article I show how Taoist philosophy has influenced the Swedish poet, essayist and aphorist Vilhelm Ekelund. I note that the author mentions the Taoist philosophers Lao Tzu and Chuang Tzu and discusses their ideas on a couple of occasions in his later works (Atticism – Humanism, 1943; Plus salis–, 1945). Examples of such explicit influence can also be found in Ekelund’s private notebooks, posthumously published in two volumes: Hemkomst och flykt (1972) and Ur en scholaris’ verkstad (1974). I argue that Taoist philosophy implicitly influenced the Swedish author as early as the second part of the 1910’s – when he started to emphasize such principles as moderation, composure, dispassion and non-desire in his writing. I also discuss other important ideals which Ekelund shared with the Taoist philosophers, such as poverty, humility, simplicity and dishonour. Finally, I see a parallel in the anti-intellectual aspects of Taoist thinking and Ekelund’s use of the term misologi (misology), a word which often has positive connotations in his works. In Ekelund’s prose, as well as in the famous Taoist text Tao Te Ching, excessive intellectualism is frequently criticized.</p
Permeability of the blood-brain barrier predicts no evidence of disease activity at two years after natalizumab or fingolimod treatment in relapsing-remitting multiple sclerosis
No full textOBJECTIVE: To investigate if blood-brain barrier (BBB) permeability, as measured by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), can provide early detection of sub-optimal treatment response in relapsing-remitting multiple sclerosis (RRMS).METHODS: 35 RRMS patients starting on fingolimod or natalizumab, drugs with a common effect of decreasing lymphocyte influx into the CNS, were scanned with DCE-MRI at 3T prior to treatment and at three and six-months post-treatment. We calculated the influx constant Ki , a measure of BBB permeability, using the Patlak model. Sub-optimal treatment response was defined as loss of no evidence of disease activity (NEDA-3) status after two years of treatment.RESULTS: Subjects with loss of NEDA status at 2 years had a 51% higher mean Ki in normal-appearing white matter (NAWM) measured after six months of treatment, compared to subjects with maintained NEDA status (mean difference 0.06 (CI 0.02-0.09) ml/100g/min; p=0.002). Ki in NAWM at 6 months was a good predictor of loss of NEDA status at two years (AUC 0.84, CI 0.70-0.99; p=0.003) and a value above 0.136 ml/100/g/min yielded an odds ratio of 12.4 for sub-optimal treatment response at 2 years, with a sensitivity of 73% and a specificity of 82%.INTERPRETATION: Our results suggest that BBB permeability as measured by DCE-MRI reliably predicts sub-optimal treatment response and is a surrogate marker of the state of health of the BBB. We find a predictive threshold for disease activity, which is remarkably identical in clinically isolated syndrome as previously reported and established RRMS as investigated here
Att framställa det oframställbara. Stig Larssons poesi och det postmoderna
No full textThe paper constitutes an analysis of the poetry of Stig
Larsson in the context of the postmodern break-up of traditional
definitions of literary genres. The characteristic features of the
Swedish poet's work are ambiguity, fragmentation, rich intertextual
references, and, most importantly, a radically undefined, diffuse
persona of the speaker, no longer able to organize the presented
world. Larsson's poetry is rich in lexical, semantic and syntactic
experimentation. The poet suggests a change in the relation
between the author and the reader
Att framställa det oframställbara. Stig Larssons poesi och det postmoderna
No full textThe paper constitutes an analysis of the poetry of Stig Larsson in the context of the postmodern break-up of traditional definitions of literary genres. The characteristic features of the Swedish poet\u27s work are ambiguity, fragmentation, rich intertextual references, and, most importantly, a radically undefined, diffuse persona of the speaker, no longer able to organize the presented world. Larsson\u27s poetry is rich in lexical, semantic and syntactic experimentation. The poet suggests a change in the relation between the author and the reader
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