| 1. |
- Björklund Svensson, Jonas, et al.
(författare)
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Low-divergence femtosecond X-ray pulses from a passive plasma lens
- 2021
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Ingår i: Nature Physics. - : Springer Science and Business Media LLC. - 1745-2481 .- 1745-2473. ; 17:5, s. 639-645
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Tidskriftsartikel (refereegranskat)abstract
- Electron and X-ray beams originating from compact laser-wakefield accelerators have very small source sizes that are typically on the micrometre scale. Therefore, the beam divergences are relatively high, which makes it difficult to preserve their high quality during transport to applications. To improve on this, tremendous efforts have been invested in controlling the divergence of the electron beams, but no mechanism for generating collimated X-ray beams has yet been demonstrated experimentally. Here we propose and realize a scheme where electron bunches undergoing focusing in a dense, passive plasma lens can emit X-ray pulses with divergences approaching the incoherent limit. Compared with conventional betatron emission, the divergence of this so-called plasma lens radiation is reduced by more than an order of magnitude in solid angle, while maintaining a similar number of emitted photons per electron. This X-ray source offers the possibility of producing brilliant and collimated few-femtosecond X-ray pulses for ultra-fast science, in particular for studies based on X-ray diffraction and absorption spectroscopy. X-ray pulses with low divergences are produced in a laser-wakefield accelerator by focusing electron bunches in a dense passive plasma lens.
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| 2. |
- Bohlooly-Yeganeh, Mohammad, 1966, et al.
(författare)
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Growth hormone overexpression in the central nervous system results in hyperphagia-induced obesity associated with insulin resistance and dyslipidemia.
- 2005
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Ingår i: Diabetes. - 0012-1797 .- 1939-327X. ; 54:1, s. 51-62
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that peripherally administered growth hormone (GH) results in decreased body fat mass. However, GH-deficient patients increase their food intake when substituted with GH, suggesting that GH also has an appetite stimulating effect. Transgenic mice with an overexpression of bovine GH in the central nervous system (CNS) were created to investigate the role of GH in CNS. This study shows that overexpression of GH in the CNS differentiates the effect of GH on body fat mass from that on appetite. The transgenic mice were not GH-deficient but were obese and showed increased food intake as well as increased hypothalamic expression of agouti-related protein and neuropeptide Y. GH also had an acute effect on food intake following intracerebroventricular injection of C57BL/6 mice. The transgenic mice were severely hyperinsulinemic and showed a marked hyperplasia of the islets of Langerhans. In addition, the transgenic mice displayed alterations in serum lipid and lipoprotein levels and hepatic gene expression. In conclusion, GH overexpression in the CNS results in hyperphagia-induced obesity indicating a dual effect of GH with a central stimulation of appetite and a peripheral lipolytic effect.
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| 3. |
- Chen, X., et al.
(författare)
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A genome-wide association study of IgM antibody against phosphorylcholine: shared genetics and phenotypic relationship to chronic lymphocytic leukemia
- 2018
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 27:10, s. 1809-1818
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorylcholine (PC) is an epitope on oxidized low-density lipoprotein (oxLDL), apoptotic cells and several pathogens like Streptococcus pneumoniae. Immunoglobulin M against PC (IgM anti-PC) has the ability to inhibit uptake of oxLDL by macrophages and increase clearance of apoptotic cells. From our genome-wide association studies (GWASs) in four European-ancestry cohorts, six single nucleotide polymorphisms (SNPs) in 11q24.1 were discovered (in 3002 individuals) and replicated (in 646 individuals) to be associated with serum level of IgM anti-PC (the leading SNP rs35923643-G, combined beta = 0.19, 95% confidence interval 0.13-0.24, P = 4.3 x 10-11). The haplotype tagged by rs35923643-G (or its proxy SNP rs735665-A) is also known as the top risk allele for chronic lymphocytic leukemia (CLL), and a main increasing allele for general IgM. By using summary GWAS results of IgM anti-PC and CLL in the polygenic risk score (PRS) analysis, PRS on the basis of IgM anti-PC risk alleles positively associated with CLL risk (explained 0.6% of CLL variance, P = 1.2 x 10-15). Functional prediction suggested that rs35923643-G might impede the binding of Runt-related transcription factor 3, a tumor suppressor playing a central role in the immune regulation of cancers. Contrary to the expectations from the shared genetics between IgM anti-PC and CLL, an inverse relationship at the phenotypic level was found in a nested case-control study (30 CLL cases with 90 age- and sex-matched controls), potentially reflecting reverse causation. The suggested function of the top variant as well as the phenotypic association between IgM anti-PC and CLL risk needs replication and motivates further studies.
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| 4. |
- Conaway, H Herschel, et al.
(författare)
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Retinoids inhibit differentiation of hematopoietic osteoclast progenitors.
- 2009
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Ingår i: The FASEB journal. - Bethesda, Md. : Wiley. - 1530-6860 .- 0892-6638. ; 23:10, s. 3526-38
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Tidskriftsartikel (refereegranskat)abstract
- Whether vitamin A promotes skeletal fragility, has no effect on fracture rate, or protects against bone loss is unclear. In the present study, effects of retinoids on osteoclast differentiation in cultured mouse bone marrow cells (BMCs), bone marrow macrophages (BMMs), spleen cells, and RAW264.7 cells were evaluated by analyzing osteoclast formation and expression of genes important in signal transduction and osteoclast function. All-trans-retinoic acid (ATRA) did not stimulate osteoclastogenesis in BMCs, but inhibited hormone and RANKL-induced gene expression and formation of osteoclasts. In BMMs, spleen cells, and RAW264.7 cells, osteoclast differentiation and formation stimulated by M-CSF/RANKL were inhibited (IC(50) = 0.3 nM) by ATRA. The effect was exerted at an early step of RANKL-induced differentiation. ATRA also abolished increases of the transcription factors c-Fos and NFAT2 stimulated by RANKL and suppressed down-regulation of the antiosteoclastogenic transcription factor MafB. By comparing effects of several compounds structurally related to ATRA, as well as by using receptor antagonists, evaluation pointed to inhibition being mediated by RARalpha, with no involvement of PPARbeta/delta. The results suggest that activation of RARalpha by retinoids in myeloid hematopoietic precursor cells decreases osteoclast formation by altering expression of the transcription factors c-Fos, NFAT2, and MafB.
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| 5. |
- Conaway, H Herschel, et al.
(författare)
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Retinoids stimulate periosteal bone resorption by enhancing the protein RANKL, a response inhibited by monomeric glucocorticoid receptor.
- 2011
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Ingår i: The Journal of biological chemistry. - 1083-351X .- 0021-9258. ; 286:36, s. 31425-36
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Tidskriftsartikel (refereegranskat)abstract
- Increased vitamin A (retinol) intake has been suggested to increase bone fragility. In the present study, we investigated effects of retinoids on bone resorption in cultured neonatal mouse calvarial bones and their interaction with glucocorticoids (GC). All-trans-retinoic acid (ATRA), retinol, retinalaldehyde, and 9-cis-retinoic acid stimulated release of (45)Ca from calvarial bones. The resorptive effect of ATRA was characterized by mRNA expression of genes associated with osteoclast differentiation, enhanced osteoclast number, and bone matrix degradation. In addition, the RANKL/OPG ratio was increased by ATRA, release of (45)Ca stimulated by ATRA was blocked by exogenous OPG, and mRNA expression of genes associated with bone formation was decreased by ATRA. All retinoid acid receptors (RARα/β/γ) were expressed in calvarial bones. Agonists with affinity to all receptor subtypes or specifically to RARα enhanced the release of (45)Ca and mRNA expression of Rankl, whereas agonists with affinity to RARβ/γ or RARγ had no effects. Stimulation of Rankl mRNA by ATRA was competitively inhibited by the RARα antagonist GR110. Exposure of calvarial bones to GC inhibited the stimulatory effects of ATRA on (45)Ca release and Rankl mRNA and protein expression. This inhibitory effect was reversed by the glucocorticoid receptor (GR) antagonist RU 486. Increased Rankl mRNA stimulated by ATRA was also blocked by GC in calvarial bones from mice with a GR mutation that blocks dimerization (GR(dim) mice). The data suggest that ATRA enhances periosteal bone resorption by increasing the RANKL/OPG ratio via RARα receptors, a response that can be inhibited by monomeric GR.
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| 6. |
- Crnalic, Sead, et al.
(författare)
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Nuclear androgen receptor staining in bone metastases is related to a poor outcome in prostate cancer patients
- 2010
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Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 17:4, s. 885-895
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Tidskriftsartikel (refereegranskat)abstract
- Androgen receptors (ARs) are probably of importance during all phases of prostate cancer (PC) growth, but their role in bone metastases is largely unexplored. Bone metastases were therefore collected from hormone-naive (n=11), short-term castrated (n=7) and castration-resistant PC (CRPC, n=44) patients by biopsy (n=4) or at surgery to alleviate symptoms from metastases complications (metastasis surgery, n=58), and immunostained for nuclear ARs, Ki67, active caspase-3, prostate-specific antigen (PSA) and chromogranin A, and results were related to serum PSA, treatments and outcome. Nuclear AR immunostaining was decreased and apoptosis was increased, but cell proliferation remained largely unaffected in metastases within a few days after surgical castration. In CRPC patients, nuclear AR staining of metastases was increased when compared to short-term castrated patients. The nuclear AR staining score was related to tumour cell proliferation, but it was not associated with other downstream effects of AR activation such as apoptosis and PSA staining, and it was only marginally related to the presence of neuroendocrine tumour cells. Serum PSA at metastasis surgery, although related to outcome, was not associated with AR staining, markers of metastasis growth or PSA staining in metastases. High nuclear AR immunostaining was associated with a particularly poor prognosis after metastasis surgery in CRPC patients, suggesting that such men may benefit from the potent AR blockers now tested in clinical trials.
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| 7. |
- Estrada, Karol, et al.
(författare)
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Genome-wide meta-analysis identifies 56 bone mineral density loci and reveals 14 loci associated with risk of fracture.
- 2012
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 44:5, s. 491-501
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Tidskriftsartikel (refereegranskat)abstract
- Bone mineral density (BMD) is the most widely used predictor of fracture risk. We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 17 genome-wide association studies and 32,961 individuals of European and east Asian ancestry. We tested the top BMD-associated markers for replication in 50,933 independent subjects and for association with risk of low-trauma fracture in 31,016 individuals with a history of fracture (cases) and 102,444 controls. We identified 56 loci (32 new) associated with BMD at genome-wide significance (P < 5 × 10(-8)). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal stem cell differentiation, endochondral ossification and Wnt signaling pathways. However, we also discovered loci that were localized to genes not known to have a role in bone biology. Fourteen BMD-associated loci were also associated with fracture risk (P < 5 × 10(-4), Bonferroni corrected), of which six reached P < 5 × 10(-8), including at 18p11.21 (FAM210A), 7q21.3 (SLC25A13), 11q13.2 (LRP5), 4q22.1 (MEPE), 2p16.2 (SPTBN1) and 10q21.1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility.
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| 8. |
- Glad, Camilla A M, 1981, et al.
(författare)
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The GH receptor exon 3 deleted/full-length polymorphism is associated with central adiposity in the general population.
- 2015
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Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - 1479-683X .- 0804-4643. ; 172:2, s. 123-128
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To test the hypothesis that the growth hormone (GH) receptor (GHR) d3/fl polymorphism influences anthropometry and body composition in the general population. Design and Setting: The Swedish Obese Subjects (SOS) reference study is a cross-sectional population-based study, randomly selected from a population registry. A sub-group of the population-based Malmö Diet and Cancer Study (MDC-CC) was used as a replication cohort. Methods: The SOS reference study comprises 1135 subjects (46.2% men), with an average age of 49.5 yrs. The MDC-CC includes 5451 successfully genotyped subjects (41.5% men), with an average age of 57.5 yrs. GHR d3/fl genotypes were determined using tagSNP rs6873545. Linear regression analyses were used to test for genotype - phenotype associations. Results: In the SOS reference study, subjects homozygous for the d3-GHR weighed approximately four kilos more (p=0.011), had larger waist-to-hip ratio (WHR, p=0.036), waist circumference (p=0.016) and more fat free mass estimated from total body potassium (TBK, p=0.026) than grouped fl/d3 and fl/fl subjects (d3-recessive genetic model). The association with WHR was replicated in the MDC-CC (p=0.002), but not those with other anthropometric traits. Conclusions: In this population-based study the GHR d3/fl polymorphism was found to be of functional relevance and associated with central adiposity, such that subjects homozygous for the d3-GHR showed an increased abdominal obesity.
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| 9. |
- Hedberg, Maria E, et al.
(författare)
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Lachnoanaerobaculum gen. nov., a new genus in the Lachnospiraceae: characterization of Lachnoanaerobaculum umeaense gen. nov., sp. nov., isolated from the human small intestine, and Lachnoanaerobaculum orale sp. nov., isolated from saliva, and reclassification of Eubacterium saburreum (Prevot 1966) Holdeman and Moore 1970 as Lachnoanaerobaculum saburreum comb. nov.
- 2012
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Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 62:Pt 11, s. 2685-90
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Tidskriftsartikel (refereegranskat)abstract
- Two novel obligately anaerobic, Gram-stain-positive, saccharolytic and non-proteolytic spore-forming bacilli (strains CD3 : 22(T) and N1(T)) are described. Strain CD3 : 22(T) was isolated from a biopsy of the small intestine of a child with coeliac disease, and strain N1(T) from the saliva of a healthy young man. The cells of both strains were observed to be filamentous, approximately 5 to >20 µm long, some of them curving and with swellings. The novel organisms produced H(2)S, NH(3), butyric acid and acetic acid as major metabolic end products. Phylogenetic analyses, based on comparative 16S rRNA gene sequencing, revealed close relationships (98 % sequence similarity) between the two isolates, as well as the type strain of Eubacterium saburreum and four other Lachnospiraceae bacterium-/E. saburreum-like organisms. This group of bacteria were clearly different from any of the 19 known genera in the family Lachnospiraceae. While Eubacterium species are reported to be non-spore-forming, reanalysis of E. saburreum CCUG 28089(T) confirmed that the bacterium is indeed able to form spores. Based on 16S rRNA gene sequencing, phenotypic and biochemical properties, strains CD3 : 22(T) and N1(T) represent novel species of a new and distinct genus, named Lachnoanaerobaculum gen. nov., in the family Lachnospiraceae [within the order Clostridiales, class Clostridia, phylum Firmicutes]. Strain CD3 : 22(T) ( = CCUG 58757(T) = DSM 23576(T)) is the type strain of the type species, Lachnoanaerobaculum umeaense gen. nov., sp. nov., of the proposed new genus. Strain N1(T) ( = CCUG 60305(T) = DSM 24553(T)) is the type strain of Lachnoanaerobaculum orale sp. nov. Moreover, Eubacterium saburreum is reclassified as Lachnoanaerobaculum saburreum comb. nov. (type strain CCUG 28089(T) = ATCC 33271(T) = CIP 105341(T) = DSM 3986(T) = JCM 11021(T) = VPI 11763(T)).
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| 10. |
- Hedberg, Maria E., et al.
(författare)
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Prevotella jejuni sp. nov., isolated from the small intestine of a child with celiac disease.
- 2013
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Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 63:11, s. 4218-4223
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Tidskriftsartikel (refereegranskat)abstract
- Five obligately anaerobic, Gram-negative, saccharolytic and proteolytic, non-spore-forming bacilli (CD3:27, CD3:28T, CD3:33, CD3:32 and CD3:34) are described. All five strains were isolated from the small intestine of a female child with celiac disease. The cells of the five strains were observed to be short rods or coccoid cells with longer filamentous forms seen sporadically. The organisms produced acetic acid and succinic acid as major metabolic end products. Phylogenetic analysis, based on comparative 16S rRNA gene sequence analysis revealed close relationships between CD3:27, CD3:28T and CD3:33 on one hand, between CD3:32 and P. histicola CCUG 55407T and between CD3:34 and P. melaninogenica CCUG 4944BT on the other. The strains CD3:27, CD3:28T and CD3:33 were clearly different from any other species within the genus Prevotella and most closely related to but distinct from P. melaninogenica. Based on 16S rRNA gene, RNA polymerase β-subunit gene and 60-kDa chaperonin protein subunit gene sequencing, phenotypic, chemical and biochemical properties strains CD3:27, CD3:28T and CD3:33 have been determined to represent a novel species within the genus Prevotella, named Prevotella jejuni sp. nov. Strain CD3:28T (CCUG 60371T = DSM 26989T) is the type strain of the proposed new species. All five strains were able to form homologous aggregates, in which tube-like structures were connecting individual bacteria cells. The five strains were able to bind to human intestinal carcinoma cell lines at 37 °C.
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