| 1. |
- Leonov, A. A., et al.
(författare)
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Separation of electrons and protons in the GAMMA-400 gamma-ray telescope
- 2015
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Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 56:7, s. 1538-1545
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Tidskriftsartikel (refereegranskat)abstract
- The GAMMA-400 telescope will measure the fluxes of gamma rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. These measurements will allow it to achieve the following scientific objectives: search for signatures of dark matter, investigation of gamma-ray point-like and extended sources, study of the energy spectrum of the Galactic and extragalactic diffuse emission, study of gamma-ray bursts and gamma-ray emission from the active Sun, together with high-precision measurements of the high-energy electrons and positrons spectra, protons and nuclei up to the knee. The bulk of cosmic rays are protons and helium nuclei, whereas the lepton component in the total flux is similar to 10(-3) at high energy. In the present paper, the simulated capability of the GAMMA-400 telescope to distinguish electrons and positrons from protons in cosmic rays is addressed. The individual contribution to the proton rejection from each detector system of GAMMA-400 is studied separately. The use of the combined information from all detectors allows us to reach a proton rejection of the order of similar to 4 x 10(5) for vertical incident particles and similar to 3 x 10(5) for particles with initial inclination of 30 degrees in the electron energy range from 50 GeV to 1 TeV. (C) 2015 COSPAR.
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| 2. |
- van der Valk, Ralf J P, et al.
(författare)
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A novel common variant in DCST2 is associated with length in early life and height in adulthood.
- 2015
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 24:4, s. 1155-68
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Tidskriftsartikel (refereegranskat)abstract
- Common genetic variants have been identified for adult height, but not much is known about the genetics of skeletal growth in early life. To identify common genetic variants that influence fetal skeletal growth, we meta-analyzed 22 genome-wide association studies (Stage 1; N = 28 459). We identified seven independent top single nucleotide polymorphisms (SNPs) (P < 1 × 10(-6)) for birth length, of which three were novel and four were in or near loci known to be associated with adult height (LCORL, PTCH1, GPR126 and HMGA2). The three novel SNPs were followed-up in nine replication studies (Stage 2; N = 11 995), with rs905938 in DC-STAMP domain containing 2 (DCST2) genome-wide significantly associated with birth length in a joint analysis (Stages 1 + 2; β = 0.046, SE = 0.008, P = 2.46 × 10(-8), explained variance = 0.05%). Rs905938 was also associated with infant length (N = 28 228; P = 5.54 × 10(-4)) and adult height (N = 127 513; P = 1.45 × 10(-5)). DCST2 is a DC-STAMP-like protein family member and DC-STAMP is an osteoclast cell-fusion regulator. Polygenic scores based on 180 SNPs previously associated with human adult stature explained 0.13% of variance in birth length. The same SNPs explained 2.95% of the variance of infant length. Of the 180 known adult height loci, 11 were genome-wide significantly associated with infant length (SF3B4, LCORL, SPAG17, C6orf173, PTCH1, GDF5, ZNFX1, HHIP, ACAN, HLA locus and HMGA2). This study highlights that common variation in DCST2 influences variation in early growth and adult height.
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| 3. |
- Romania, P., et al.
(författare)
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Identification of a Genetic Variation in ERAP1 Aminopeptidase that Prevents Human Cytomegalovirus miR-UL112-5p-Mediated Immunoevasion
- 2017
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 20:4, s. 846-853
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we demonstrate that HCMV miR-UL112-5p targets ERAP1, thereby inhibiting the processing and presentation of the HCMV pp65495-503 peptide to specific CTLs. In addition, we show that the rs17481334 G variant, naturally occurring in the ERAP1 30 UTR, preserves ERAP1 from miR-UL1125p-mediated degradation. Specifically, HCMV miRUL112-5p binds the 30 UTR of ERAP1 A variant, but not the 30 UTR of ERAP1 G variant, and, accordingly, ERAP1 expression is reduced both at RNA and protein levels only in human fibroblasts homozygous for the A variant. Consistently, HCMV-infected GG fibroblasts were more efficient in trimming viral antigens and being lysed by HCMV-peptide-specific CTLs. Notably, a significantly decreased HCMV seropositivity was detected among GG individuals suffering from multiple sclerosis, a disease model in which HCMV is negatively associated with adultonset disorder. Overall, our results identify a resistance mechanism to HCMV miR-UL112-5p-based immune evasion strategy with potential implications for individual susceptibility to infection and other diseases.
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| 4. |
- Uphoff, EP, et al.
(författare)
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Variations in the prevalence of childhood asthma and wheeze in MeDALL cohorts in Europe
- 2017
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Ingår i: ERJ open research. - : European Respiratory Society (ERS). - 2312-0541. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- While there is evidence for variations in prevalence rates of childhood wheeze and asthma between countries, longitudinal, individual-level data are needed to understand these differences. The aim of this study was to examine variations in prevalence rates of childhood asthma, wheeze and wheeze with asthma in Europe.We analysed datasets from 10 MeDALL (Mechanisms of the Development of ALLergy) cohorts in eight countries, representing 26 663 children, to calculate prevalence rates of wheeze and asthma by child age and wheeze with asthma at age 4 years. Harmonised variables included outcomes parent-reported wheeze and parent-reported doctor-diagnosed asthma, and covariates maternal education, parental smoking, pets, parental asthma, doctor-diagnosed allergic rhinitis, doctor-diagnosed eczema and wheeze severity.At age 4 years, asthma prevalence varied from 1.72% in Germany to 13.48% in England and the prevalence of wheeze varied from 9.82% in Greece to 55.37% in Spain. Adjusted estimates of the proportion of 4-year-old children with wheeze diagnosed with asthma remained highest in England (38.14%, 95% CI 31.38–44.90%) and lowest in Spain (15.94%, 95% CI 6.16–25.71%).The large differences in prevalence rates of asthma, wheeze and wheeze with asthma at age 4 years between European cohorts may indicate that childhood asthma is more readily diagnosed in some countries while going unrecognised elsewhere.
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| 5. |
- Abdelmagid, N., et al.
(författare)
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Von Willebrand Factor Gene Variants Associate with Herpes simplex Encephalitis
- 2016
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex encephalitis (HSE) is a rare complication of Herpes simplex virus type-1 infection. It results in severe parenchymal damage in the brain. Although viral latency in neurons is very common in the population, it remains unclear why certain individuals develop HSE. Here we explore potential host genetic variants predisposing to HSE. In order to investigate this we used a rat HSE model comparing the HSE susceptible SHR (Spontaneously Hypertensive Rats) with the asymptomatic infection of BN (Brown Norway). Notably, both strains have HSV-1 spread to the CNS at four days after infection. A genome wide linkage analysis of 29 infected HXB/BXH RILs (recombinant inbred lines-generated from the prior two strains), displayed variable susceptibility to HSE enabling the definition of a significant QTL (quantitative trait locus) named Hse6 towards the end of chromosome 4 (160.89-174Mb) containing the Vwf (von Willebrand factor) gene. This was the only gene in the QTL with both cis-regulation in the brain and included several non-synonymous SNPs (single nucleotide polymorphism). Intriguingly, in human chromosome 12 several SNPs within the intronic region between exon 43 and 44 of the VWF gene were associated with human HSE pathogenesis. In particular, rs917859 is nominally associated with an odds ratio of 1.5 (95% CI 1.11-2.02; p-value = 0.008) after genotyping in 115 HSE cases and 428 controls. Although there are possibly several genetic and environmental factors involved in development of HSE, our study identifies variants of the VWF gene as candidates for susceptibility in experimental and human HSE.
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| 6. |
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| 7. |
- Andersson, Maria, et al.
(författare)
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Coinfection with Enteric Pathogens in East African Children with Acute Gastroenteritis-Associations and Interpretations
- 2018
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Ingår i: American Journal of Tropical Medicine and Hygiene. - : American Society of Tropical Medicine and Hygiene. - 0002-9637 .- 1476-1645. ; 98:6, s. 1566-1570
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Tidskriftsartikel (refereegranskat)abstract
- Enteric coinfections among children in low-income countries are very common, but it is not well known if specific pathogen combinations are associated or have clinical importance. In this analysis, feces samples from children in Rwanda and Zanzibar less than 5 years of age, with (N = 994) or without (N = 324) acute diarrhea, were analyzed by realtime polymerase chain reaction targeting a wide range of pathogens. Associations were investigated by comparing codetection and mono-detection frequencies for all pairwise pathogen combinations. More than one pathogen was detected in 840 samples (65%). A negative association (coinfections being less common than expected from probability) was observed for rotavirus in combination with Shigella, Campylobacter, or norovirus genogroup II, but only in patients, which is statistically expected for agents that independently cause diarrhea. A positive correlation was observed, in both patients and controls, between Ct (threshold cycle) values for certain virulence factor genes in enteropathogenic Escherichia coli (EPEC) (eae and bfpA) and toxin genes in enterotoxigenic E. coli (eltB and estA), allowing estimation of how often these genes were present in the same bacteria. A significant positive association in patients only was observed for Shigella andEPEC-eae, suggesting that this coinfection might interact in a manner that enhances symptoms. Although interaction between pathogens that affect symptoms is rare, this work emphasizes the importance and difference in interpretation of coinfections depending on whether they are positively or negatively associated.
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| 8. |
- Bergström, Gunnar, et al.
(författare)
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Preventing sickness absenteeism among employees with common mental disorders or stress-related symptoms at work : Design of a cluster randomized controlled trial of a problem-solving based intervention versus care-as-usual conducted at the Occupational Health Services
- 2017
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Ingår i: BMC Public Health. - : BioMed Central. - 1471-2458. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Common mental disorders (CMDs) are among the leading causes of sick leave in Sweden and other OECD countries. They result in suffering for the individual and considerable financial costs for the employer and for society at large. The occupational health service (OHS) can offer interventions in which both the individual and the work situation are taken into account. The aim of this paper is to describe the design of a study evaluating the effectiveness of an intervention given at the OHS to employees with CMDs or stress-related symptoms at work. In addition, intervention fidelity and its relation to the outcome will be assessed in a process analysis.Methods: The study is designed as a cluster randomized trial in which the participating OHS consultants are randomized into either delivering the intervention or performing care as usual. Employees with CMDs or stress-related symptoms at work are recruited consecutively by the OHS consultants. The intervention aims to improve the match between the employee and the job situation. Interviews are held individually with the employee and the nearest supervisor, after which a joint meeting with both the employee and the supervisor takes place. A participatory approach is applied by which the supervisor and the employee are guided by the OHS consultant and encouraged to actively take part in problem solving concerning the work situation. Outcomes will be assessed at baseline and at six and 12 months. A long-term follow-up at 3 years will also be performed. The primary outcome is registered sickness absence during a 1-year period after study inclusion. Secondary outcomes are mental health and work ability. The intervention's cost effectiveness, compared to treatment as usual, both for society and for the employer will be evaluated. A process evaluation by both the OHS consultants and the employee will be carried out.Discussion: The study includes analyses of the effectiveness of the intervention (clinical and economic) as well as an analysis of its implementation at the participating OHSs. Possible methodological challenges such as selection bias and risk of contamination between OHS consultants delivering the experimental condition and consultants giving usual care are discussed.
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| 9. |
- Bergström, I., et al.
(författare)
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Compressive loading of the murine tibia reveals site-specific micro-scale differences in adaptation and maturation rates of bone
- 2017
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 28:3, s. 1121-1131
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Tidskriftsartikel (refereegranskat)abstract
- Summary: Loading increases bone mass and strength in a site-specific manner; however, possible effects of loading on bone matrix composition have not been evaluated. Site-specific structural and material properties of mouse bone were analyzed on the macro- and micro/molecular scale in the presence and absence of axial loading. The response of bone to load is heterogeneous, adapting at molecular, micro-, and macro-levels. Introduction: Osteoporosis is a degenerative disease resulting in reduced bone mineral density, structure, and strength. The overall aim was to explore the hypothesis that changes in loading environment result in site-specific adaptations at molecular/micro- and macro-scale in mouse bone. Methods: Right tibiae of adult mice were subjected to well-defined cyclic axial loading for 2 weeks; left tibiae were used as physiologically loaded controls. The bones were analyzed with μCT (structure), reference point indentation (material properties), Raman spectroscopy (chemical), and small-angle X-ray scattering (mineral crystallization and structure). Results: The cranial and caudal sites of tibiae are structurally and biochemically different within control bones. In response to loading, cranial and caudal sites increase in cortical thickness with reduced mineralization (−14 and −3%, p < 0.01, respectively) and crystallinity (−1.4 and −0.3%, p < 0.05, respectively). Along the length of the loaded bones, collagen content becomes more heterogeneous on the caudal site and the mineral/collagen increases distally at both sites. Conclusion: Bone structure and composition are heterogeneous, finely tuned, adaptive, and site-specifically responsive at the micro-scale to maintain optimal function. Manipulation of this heterogeneity may affect bone strength, relative to specific applied loads.
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| 10. |
- Bergström, I., et al.
(författare)
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Prednisolone treatment reduces the osteogenic effects of loading in mice
- 2018
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Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 112, s. 10-18
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Tidskriftsartikel (refereegranskat)abstract
- Glucocorticoid treatment, a major cause of drug-induced osteoporosis and fractures, is widely used to treat inflammatory conditions and diseases. By contrast, mechanical loading increases bone mass and decreases fracture risk. With these relationships in mind, we investigated whether mechanical loading interacts with GC treatment in bone. Three-month-old female C57BL/6 mice were treated with high-dose prednisolone (15 mg/60 day pellets/mouse) or vehicle for two weeks. During the treatment, right tibiae were subjected to short periods of cyclic compressive loading three times weekly, while left tibiae were used as physiologically loaded controls. The bones were analyzed using peripheral quantitative computed tomography, histomorphometry, real-time PCR, three-point bending and Fourier transform infrared micro-spectroscopy. Loading alone increased trabecular volumetric bone mineral density (vBMD), cortical thickness, cortical area, osteoblast-associated gene expression, osteocyte- and osteoclast number, and bone strength. Prednisolone alone decreased cortical area and thickness and osteoblast-associated gene expression. Importantly, prednisolone treatment decreased the load-induced increase in trabecular vBMD by 57% (p < 0.001) and expression of osteoblast-associated genes, while completely abolishing the load-induced increase in cortical area, cortical thickness, number of osteocytes and osteoclasts, and bone strength. When combined, loading and prednisolone decreased the collagen content. In conclusion, high-dose prednisolone treatment strongly inhibits the loading-induced increase in trabecular BMD, and abolishes the loading-induced increase in cortical bone mass. This phenomenon could be due to prednisolone inhibition of osteoblast differentiation and function.
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