| 1. |
- Kassemeyer, Stephan, et al.
(författare)
-
Femtosecond free-electron laser x-ray diffraction data sets for algorithm development
- 2012
-
Ingår i: Optics Express. - 1094-4087. ; 20:4, s. 4149-4158
-
Tidskriftsartikel (refereegranskat)abstract
- We describe femtosecond X-ray diffraction data sets of viruses and nanoparticles collected at the Linac Coherent Light Source. The data establish the first large benchmark data sets for coherent diffraction methods freely available to the public, to bolster the development of algorithms that are essential for developing this novel approach as a useful imaging technique. Applications are 2D reconstructions, orientation classification and finally 3D imaging by assembling 2D patterns into a 3D diffraction volume.
|
|
| 2. |
- Yoon, Chun Hong, et al.
(författare)
-
Unsupervised classification of single-particle X-ray diffraction snapshots by spectral clustering
- 2011
-
Ingår i: Optics Express. - 1094-4087. ; 19:17, s. 16542-16549
-
Tidskriftsartikel (refereegranskat)abstract
- Single-particle experiments using X-ray Free Electron Lasers produce more than 10(5) snapshots per hour, consisting of an admixture of blank shots (no particle intercepted), and exposures of one or more particles. Experimental data sets also often contain unintentional contamination with different species. We present an unsupervised method able to sort experimental snapshots without recourse to templates, specific noise models, or user-directed learning. The results show 90% agreement with manual classification.
|
|
| 3. |
|
|
| 4. |
- Barends, Thomas R. M., et al.
(författare)
-
Structure and mechanism of a bacterial light-regulated cyclic nucleotide phosphodiesterase
- 2009
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 459, s. 1015-1018
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to respond to light is crucial for most organisms. BLUF is a recently identified photoreceptor protein domain that senses blue light using a FAD chromophore. BLUF domains are present in various proteins from the Bacteria, Euglenozoa and Fungi. Although structures of single-domain BLUF proteins have been determined, none are available for a BLUF protein containing a functional output domain; the mechanism of light activation in this new class of photoreceptors has thus remained poorly understood. Here we report the biochemical, structural and mechanistic characterization of a full-length, active photoreceptor, BlrP1 (also known as KPN_01598), from Klebsiella pneumoniae. BlrP1 consists of a BLUF sensor domain and a phosphodiesterase EAL output domain which hydrolyses cyclic dimeric GMP (c-di-GMP). This ubiquitous second messenger controls motility, biofilm formation, virulence and antibiotic resistance in the Bacteria. Crystal structures of BlrP1 complexed with its substrate and metal ions involved in catalysis or in enzyme inhibition provide a detailed understanding of the mechanism of the EAL-domain c-di-GMP phosphodiesterases. These structures also sketch out a path of light activation of the phosphodiesterase output activity. Photon absorption by the BLUF domain of one subunit of the antiparallel BlrP1 homodimer activates the EAL domain of the second subunit through allosteric communication transmitted through conserved domain-domain interfaces.
|
|
| 5. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
-
Megraft: A software package to graft ribosomal small subunit (16S/18S) fragments onto full-length sequences for accurate species richness and sequencing depth analysis in pyrosequencing-length metagenomes
- 2012
-
Ingår i: Research in Microbiology. - : Elsevier BV. - 0923-2508. ; 163:6-7, s. 407-412
-
Tidskriftsartikel (refereegranskat)abstract
- Metagenomic libraries represent subsamples of the total DNA found at a study site and offer unprecedented opportunities to study ecological and functional aspects of microbial communities. To examine the depth of a community sequencing effort, rarefaction analysis of the ribosomal small subunit (SSU/16S/18S) gene in the metagenome is usually performed. The fragmentary, non-overlapping nature of SSU sequences in metagenomic libraries poses a problem for this analysis, however. We introduce a software package – Megraft – that grafts SSU fragments onto full-length SSU sequences, accounting for observed and unobserved variability, for accurate assessment of species richness and sequencing depth in metagenomics endeavors.
|
|
| 6. |
- Docherty, Anna R, et al.
(författare)
-
GWAS Meta-Analysis of Suicide Attempt: Identification of 12 Genome-Wide Significant Loci and Implication of Genetic Risks for Specific Health Factors.
- 2023
-
Ingår i: The American journal of psychiatry. - : American Psychiatric Association Publishing. - 1535-7228 .- 0002-953X. ; 180:10, s. 723-738
-
Tidskriftsartikel (refereegranskat)abstract
- Suicidal behavior is heritable and is a major cause of death worldwide. Two large-scale genome-wide association studies (GWASs) recently discovered and cross-validated genome-wide significant (GWS) loci for suicide attempt (SA). The present study leveraged the genetic cohorts from both studies to conduct the largest GWAS meta-analysis of SA to date. Multi-ancestry and admixture-specific meta-analyses were conducted within groups of significant African, East Asian, and European ancestry admixtures.This study comprised 22 cohorts, including 43,871 SA cases and 915,025 ancestry-matched controls. Analytical methods across multi-ancestry and individual ancestry admixtures included inverse variance-weighted fixed-effects meta-analyses, followed by gene, gene-set, tissue-set, and drug-target enrichment, as well as summary-data-based Mendelian randomization with brain expression quantitative trait loci data, phenome-wide genetic correlation, and genetic causal proportion analyses.Multi-ancestry and European ancestry admixture GWAS meta-analyses identified 12 risk loci at p values <5×10-8. These loci were mostly intergenic and implicated DRD2, SLC6A9, FURIN, NLGN1, SOX5, PDE4B, and CACNG2. The multi-ancestry SNP-based heritability estimate of SA was 5.7% on the liability scale (SE=0.003, p=5.7×10-80). Significant brain tissue gene expression and drug set enrichment were observed. There was shared genetic variation of SA with attention deficit hyperactivity disorder, smoking, and risk tolerance after conditioning SA on both major depressive disorder and posttraumatic stress disorder. Genetic causal proportion analyses implicated shared genetic risk for specific health factors.This multi-ancestry analysis of suicide attempt identified several loci contributing to risk and establishes significant shared genetic covariation with clinical phenotypes. These findings provide insight into genetic factors associated with suicide attempt across ancestry admixture populations, in veteran and civilian populations, and in attempt versus death.
|
|
| 7. |
- Fuchs, David, et al.
(författare)
-
Scoring the Risk of Having Systemic Mastocytosis in Adult Patients with Mastocytosis in the Skin
- 2021
-
Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier. - 2213-2198 .- 2213-2201. ; 9:4, s. 1705-1712.e4
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mastocytosis in adults often presents with skin lesions. A bone marrow biopsy is necessary to confirm or exclude the presence of systemic mastocytosis (SM) in these cases. When a bone marrow biopsy is not performed, the provisional diagnosis is mastocytosis in the skin (MIS). No generally accepted scoring system has been established to estimate the risk of SM in these patients. OBJECTIVE: To develop a risk score to predict SM in adults with MIS. METHODS: We examined 1145 patients with MIS from the European Competence Network on Mastocytosis Registry who underwent a bone marrow biopsy. A total of 944 patients had SM and 201 patients had cutaneous mastocytosis; 63.7% were female, and 36.3% were male. Median age was 44 +/- 13.3 years. The median serum tryptase level amounted to 29.3 +/- 81.9 ng/mL. We established a multivariate regression model using the whole population of patients as a training and validation set (bootstrapping). A risk score was developed and validated with receiver-operating curves. RESULTS: In the multivariate model, the tryptase level (P < .001), constitutional/cardiovascular symptoms (P = .014), and bone symptoms/osteoporosis (P < .001) were independent predictors of SM (P < .001; sensitivity, 90.7%; specificity, 69.1%). A 6-point risk score was established (risk, 10.7%-98.0%) and validated. CONCLUSIONS: Using a large data set of the European Competence Network on Mastocytosis Registry, we created a risk score to predict the presence of SM in patients with MIS. Although the score will need further validation in independent cohorts, our score seems to discriminate safely between patients with SM and with pure cutaneous mastocytosis. (C) 2020 American Academy of Allergy, Asthma & Immunology
|
|
| 8. |
- Kluin-Nelemans, Hanneke C., et al.
(författare)
-
Prognostic impact of eosinophils in mastocytosis : analysis of 2350 patients collected in the ECNM Registry
- 2020
-
Ingår i: Leukemia. - : Nature Publishing Group. - 0887-6924 .- 1476-5551. ; 34:4, s. 1090-1101
-
Tidskriftsartikel (refereegranskat)abstract
- Systemic mastocytosis (SM) is frequently associated with eosinophilia. To examine its prevalence and clinical impact in all WHO classification-based subcategories, we analyzed eosinophil counts in 2350 mastocytosis patients using the dataset of the European Competence Network on Mastocytosis. Ninety percent of patients had normal eosinophil counts, 6.8% mild eosinophilia (0.5-1.5x10(9)/l), and 3.1% hypereosinophilia (HE; >1.5x10(9)/l). Eosinophilia/HE were mainly present in patients with advanced SM (17%/19%), and only rarely recorded in patients with indolent and smoldering SM (5%/1%), and some patients with cutaneous mastocytosis. The eosinophil count correlated with organomegaly, dysmyelopoiesis, and the WHO classification, but not with mediator-related symptoms or allergy. Eosinophilia at diagnosis had a strong prognostic impact (p<0.0001) on overall survival (OS) and progression-free survival (PFS), with a 10-year OS of 19% for patients with HE, 70% for those with mild eosinophilia, and 88% for patients with normal eosinophil counts. In 89% of patients with follow-up data (n=1430, censored at start of cytoreductive therapy), eosinophils remained stable. In those with changing eosinophil counts (increase/decrease or mixed pattern), OS and PFS were inferior compared with patients with stable eosinophil counts. In conclusion, eosinophilia and HE are more prevalent in advanced SM and are predictors of a worse outcome.
|
|
| 9. |
- Mullins, Niamh, et al.
(författare)
-
Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors
- 2022
-
Ingår i: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 91:3, s. 313-327
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders.METHODS: We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors.RESULTS: Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged.CONCLUSIONS: Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.
|
|
| 10. |
- Nass, Karol, et al.
(författare)
-
Indications of radiation damage in ferredoxin microcrystals using high-intensity X-FEL beams
- 2015
-
Ingår i: Journal of Synchrotron Radiation. - 0909-0495 .- 1600-5775. ; 22:2, s. 225-238
-
Tidskriftsartikel (refereegranskat)abstract
- Proteins that contain metal cofactors are expected to be highly radiation sensitive since the degree of X-ray absorption correlates with the presence of high-atomic-number elements and X-ray energy. To explore the effects of local damage in serial femtosecond crystallography (SFX), Clostridium ferredoxin was used as a model system. The protein contains two [4Fe–4S] clusters that serve as sensitive probes for radiation-induced electronic and structural changes. High-dose room-temperature SFX datasets were collected at the Linac Coherent Light Source of ferredoxin microcrystals. Difference electron density maps calculated from high-dose SFX and synchrotron data show peaks at the iron positions of the clusters, indicative of decrease of atomic scattering factors due to ionization. The electron density of the two [4Fe–4S] clusters differs in the FEL data, but not in the synchrotron data. Since the clusters differ in their detailed architecture, this observation is suggestive of an influence of the molecular bonding and geometry on the atomic displacement dynamics following initial photoionization. The experiments are complemented by plasma code calculations.
|
|
