| 11. |
- Ludvigsson, Johnny, et al.
(författare)
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GAD65 antigen therapy in recently diagnosed type 1 diabetes mellitus
- 2012
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Ingår i: New England Journal of Medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 366:5, s. 433-442
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The 65-kD isoform of glutamic acid decarboxylase (GAD65) is a major autoantigen in type 1 diabetes. We hypothesized that alum-formulated GAD65 (GAD-alum) can preserve beta-cell function in patients with recent-onset type 1 diabetes.METHODS: We studied 334 patients, 10 to 20 years of age, with type 1 diabetes, fasting C-peptide levels of more than 0.3 ng per milliliter (0.1 nmol per liter), and detectable serum GAD65 autoantibodies. Within 3 months after diagnosis, patients were randomly assigned to receive one of three study treatments: four doses of GAD-alum, two doses of GAD-alum followed by two doses of placebo, or four doses of placebo. The primary outcome was the change in the stimulated serum C-peptide level (after a mixed-meal tolerance test) between the baseline visit and the 15-month visit. Secondary outcomes included the glycated hemoglobin level, mean daily insulin dose, rate of hypoglycemia, and fasting and maximum stimulated C-peptide levels.RESULTS: The stimulated C-peptide level declined to a similar degree in all study groups, and the primary outcome at 15 months did not differ significantly between the combined active-drug groups and the placebo group (P=0.10). The use of GAD-alum as compared with placebo did not affect the insulin dose, glycated hemoglobin level, or hypoglycemia rate. Adverse events were infrequent and mild in the three groups, with no significant differences.CONCLUSIONS: Treatment with GAD-alum did not significantly reduce the loss of stimulated C peptide or improve clinical outcomes over a 15-month period.
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| 12. |
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| 13. |
- Lundström, Linda, et al.
(författare)
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Symmetries in peripheral ocular aberrations
- 2011
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Ingår i: Journal of Modern Optics. - : Informa UK Limited. - 0950-0340 .- 1362-3044. ; 58:19-20, s. 1690-1695
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Tidskriftsartikel (refereegranskat)abstract
- A mirror symmetry in the aberrations between the left and right eyes has previously been found foveally, but while a similar symmetry for the peripheral visual field is likely, it has not been investigated. Nevertheless, the peripheral optical quality is often evaluated in only one eye, because it is more time efficient than analyzing the whole visual field of both eyes. This study investigates the correctness of such an approach by measuring the peripheral wavefront aberrations in both eyes of 22 subjects out to +/- 40 degrees horizontally. The largest aberrations (defocus, astigmatism, and coma) were found to be significantly correlated between the left and right eyes when comparing the same temporal or nasal angle. The slope of the regression line was close to +/- 1 (within 0.05) for these aberrations, with a negative slope for the horizontally odd aberrations, i.e. the left and right eyes are mirror symmetric. These findings justify that the average result, sampled in one of the two eyes of many subjects, can be generalized to the other eye as well.
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| 14. |
- Lundström, Robert, 1973-
(författare)
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Comparing Procurement Methods in Road Construction Projects : Influence on Uncertainty, Interaction and Knowledge
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The construction sector is often considered to show a number of limitations regarding efficiency and effectiveness, conclusions normally drawn irrespective of project procurement method used, and despite the common assumption that differences among approaches exist regarding these aspects. The study investigates differences and similarities among procurement methods using a longitudinal multi-case study based on two comparatively large infrastructure projects: a traditional so-called design-bid-build project and an unconventional so-called design-build-maintain project. The empirical part of the investigation, which in addition to the two focal projects mentioned also includes a number of prior and subsequent projects, was conducted based on literature studies, interviews and observations. The complex organizational phenomenon associated with each case was studied partly by interpreting each focal project as a small temporary network comprising a client, a contractor and a consultant, and partly any connections from the focal project to other projects of the organizational context. The influence of the procurement method was investigated using a model comprising the three concepts of uncertainty, interaction and knowledge. The empirical findings suggest that significant differences exist between the two approaches investigated regarding all three concepts. In principle, the traditional procurement approach resulted in low degrees of uncertainty, interaction and knowledge, while the unconventional project resulted in higher degrees. Although differences regarding the procurement methods can be observed by directly comparing the two focal projects, the influence of procurement method on uncertainty, interaction and knowledge gained becomes even more interesting if the time-frame is extended beyond the immediate projects studied. In particular, the comparison of the two cases presented indicates differences regarding the establishment of inter-project connections. The theoretical framework utilized in the study contributes to previous research by providing a way to characterize procurement methods, differences among them, and how knowledge is gained in relation to interaction and uncertainty.
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| 15. |
- Lundström, Sebastian, et al.
(författare)
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Trajectories leading to autism spectrum disorders are affected by paternal age: findings from two nationally representative twin studies.
- 2010
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Ingår i: Journal of Child Psychology and Psychiatry, and Allied Disciplines. - : Wiley. - 0021-9630 .- 1469-7610. ; 51:7, s. 850-856
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite extensive efforts, the causes of autism remain unknown. Advancing paternal age has been associated with various neurodevelopmental disorders. We aim to investigate three unresolved questions: (a) What is the association between paternal age and autism spectrum disorders (ASD)?; (b) Does paternal age moderate the genetic and environmental etiological factors for ASD? (c) Does paternal age affect normal variation in autistic-like traits? Methods: Two nationally representative twin studies from Sweden (n = 11, 122, assessed at age 9 or 12) and the UK (n = 13, 524, assessed at age 9) were used. Categorical and continuous measures of ASD, autistic-like traits and autistic similarity were calculated and compared over paternal age categories. Results: Both cohorts showed a strong association between paternal age and the risk for ASD. A U-shaped risk association could be discerned since the offspring of both the youngest and oldest fathers showed an elevation in the risk for ASD. Autistic similarity increased with advancing paternal age in both monozygotic and dizygotic twins. Both cohorts showed significantly higher autistic-like traits in the offspring of the youngest and oldest fathers. Conclusions: Phenomena associated with paternal age are clearly involved in the trajectories leading to autistic-like traits and ASD. Mechanisms influencing the trajectories might differ between older and younger fathers. Molecular genetic studies are now needed in order to further understand the association between paternal age and ASD, as well as normal variation in social, language, and repetitive behaviors in the general population.
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| 16. |
- Pesudovs, Konrad, et al.
(författare)
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Measuring the Patient's Perspective.
- 2013
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Ingår i: Optometry and Vision Science. - : Ovid Technologies (Wolters Kluwer Health). - 1538-9235 .- 1040-5488. ; 90:8, s. 717-719
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Tidskriftsartikel (refereegranskat)
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| 17. |
- Pettersson, Anna Lindskoog, et al.
(författare)
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Accommodation in young adults wearing aspheric multifocal soft contact lenses
- 2011
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Ingår i: Journal of Modern Optics. - : Informa UK Limited. - 0950-0340 .- 1362-3044. ; 58:19-20, s. 1804-1808
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present project was to investigate accommodative behavior in young adults and adolescents fitted with an aspheric multifocal (center distance) contact lens with focus on evaluating whether these lenses can be an alternative treatment for subjects in which a reduced level of blur and thereby accommodation in near vision is aimed at. Twenty normal subjects aged between 21 and 35 years participated in the study. Aberrometry was perfomed using a Zywave (TM) aberrometer, first on the uncorrected eyes of all subjects, and again while the subjects wore a multifocal contact lens with a +1.00 add. A Shin-Nippon N Vision-K 5001 Autoref-Keratometer was used to measure accommodative response with two different refractive corrections: (1) habitual spectacle correction only, and (2) habitual correction and a aspheric multifocal (center distance) contact lens. Four hours of adaptation to the lens was allowed. The lag when wearing only the habitual spectacles was compared with the lag while wearing both the habitual spectacles and the aspheric multifocal contact lens. The mean lag of accommodation for the subject group was 0.85 D (+/-0.57 SD) and 0.75 D (+/-0.52 SD) without and with the multifocal lens, respectively. Statistical analyses showed no difference in lag (t = 0.8479, p = 0.407) with and without the lens. In conclusion, young normal subjects do not relax accommodation when fitted with aspheric multifocal center distance lenses when the addition is +1.00. It is therefore unlikely that subjects with accommodative ability, in whom the treatment purpose is to reduce blur and thereby accommodation, can be effectively treated with such lenses.
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| 18. |
- Rosén, Robert, et al.
(författare)
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Adaptive optics for peripheral vision
- 2012
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Ingår i: Journal of Modern Optics. - : Informa UK Limited. - 0950-0340 .- 1362-3044. ; 59:12, s. 1064-1070
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Tidskriftsartikel (refereegranskat)abstract
- Understanding peripheral optical errors and their impact on vision is important for various applications, e.g. research on myopia development and optical correction of patients with central visual field loss. In this study, we investigated whether correction of higher order aberrations with adaptive optics (AO) improve resolution beyond what is achieved with best peripheral refractive correction. A laboratory AO system was constructed for correcting peripheral aberrations. The peripheral low contrast grating resolution acuity in the 20 nasal visual field of the right eye was evaluated for 12 subjects using three types of correction: refractive correction of sphere and cylinder, static closed loop AO correction and continuous closed loop AO correction. Running AO in continuous closed loop improved acuity compared to refractive correction for most subjects (maximum benefit 0.15logMAR). The visual improvement from aberration correction was highly correlated with the subject's initial amount of higher order aberrations (p=0.001, R 2=0.72). There was, however, no acuity improvement from static AO correction. In conclusion, correction of peripheral higher order aberrations can improve low contrast resolution, provided refractive errors are corrected and the system runs in continuous closed loop.
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| 19. |
- Rosén, Robert, et al.
(författare)
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Evaluating the peripheral optical effect of multifocal contact lenses
- 2012
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Ingår i: Ophthalmic & physiological optics. - : Wiley. - 0275-5408 .- 1475-1313. ; 32:6, s. 527-534
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Multifocal soft contact lenses have been used to decrease the progression of myopia, presumably by inducing relative peripheral myopia at the same time as the central image is focused on the fovea. The aim of this study was to investigate how the peripheral optical effect of commercially available multifocal soft contact lenses can be evaluated from objective wavefront measurements. Methods: Two multifocal lenses with high and low add and one monofocal design were measured over the ±40° horizontal field, using a scanning Hartmann-Shack wavefront sensor on four subjects. The effect on the refractive shift, the peripheral image quality, and the depth of field of the lenses was evaluated using the area under the modulation transfer function as the image quality metric. Results: The multifocal lenses with a centre distance design and 2 dioptres of add induced about 0.50 dioptre of relative peripheral myopia at 30° in the nasal visual field. For larger off-axis angles the border of the optical zone of the lenses severely degraded image quality. Moreover, these multifocal lenses also significantly reduced the image quality and increased the depth of field for angles as small as 10°-15° Conclusions: The proposed methodology showed that the tested multifocal soft contact lenses gave a very small peripheral myopic shift in these four subjects and that they would need a larger optical zone and a more controlled depth of field to explain a possible treatment effect on myopia progression.
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| 20. |
- Rosén, Robert, et al.
(författare)
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Have we misinterpreted the study of Hoogerheide et al. (1971)?
- 2012
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Ingår i: Optometry and Vision Science. - 1040-5488 .- 1538-9235. ; 89:8, s. 1235-1237
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Tidskriftsartikel (refereegranskat)abstract
- In 1971, Rempt et al. reported peripheral refraction patterns (skiagrams) along the horizontal visual field in 442 people. Later in the same year, Hoogerheide et al. used skiagrams in combination with medical records to relate skiagrams in emmetropes and hyperopes to progression of myopia in young adults. The two articles have spurred interest in peripheral refraction in the past decade. We challenge the understanding that their articles provide evidence that the peripheral refraction pattern along the horizontal visual field is predictive of whether or not a person develops myopia. First, although it has been generally assumed that the skiagrams were measured before the changes in refraction were monitored, Hoogerheide et al. did not state that this was the case. Second, if the skiagrams were obtained at an initial examination and given the likely rates of recruitment and successful completion of training, the study must have taken place during a period of 10 to 15 years; it is much more likely that Hoogerheide et al. measured the skiagrams in a shorter period. Third, despite there being many more emmetropes and hyperopes in the Rempt et al. article than there are in the Hoogerheide et al. article, the number of people in two types of "at risk" skiagrams is greater in the latter; this is consistent with the central refraction status being reported from an earlier time by Hoogerheide et al. than by Rempt et al. In summary, we believe that the skiagrams reported by Hoogerheide et al. were taken at a later examination, after myopia did or did not occur, and that the refraction data from the initial examination were retrieved from the medical archives. Thus, this work does not provide evidence that peripheral refraction pattern is indicative of the likely development of myopia.
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