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| 2. |
- Miltiadous, O., et al.
(författare)
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Early intestinal microbial features are associated with CD4 T-cell recovery after allogeneic hematopoietic transplant
- 2022
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 139:18, s. 2758-2769
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Tidskriftsartikel (refereegranskat)abstract
- Low intestinal microbial diversity is associated with poor outcomes after allogeneic hematopoietic cell transplantation (HCT). Using 16S rRNA sequencing of 2067 stool samples and flow cytometry data from 2370 peripheral blood samples drawn from 894 patients who underwent allogeneic HCT, we have linked features of the early post-HCT microbiome with subsequent immune cell recovery. We examined lymphocyte recovery and microbiota features in recipients of both unmodified and CD34-selected allografts. We observed that fecal microbial diversity was an independent predictor of CD4 T-cell count 3 months after HCT in recipients of a CD34-selected allograft, who are dependent on de novo lymphopoiesis for their immune recovery. In multivariate models using clinical factors and microbiota features, we consistently observed that increased fecal relative abundance of genus Staphylococcus during the early posttransplant period was associated with worse CD4 T-cell recovery. Our observations suggest that the intestinal bacteria, or the factors they produce, can affect early lymphopoiesis and the homeostasis of allograft-derived T cells after transplantation.
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| 3. |
- Carrington, G., et al.
(författare)
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Human skeletal myopathy myosin mutations disrupt myosin head sequestration
- 2023
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Ingår i: JCI Insight. - 2379-3708. ; 8:21
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Tidskriftsartikel (refereegranskat)abstract
- Myosin heavy chains encoded by MYH7 and MYH2 are abundant in human skeletal muscle and important for muscle contraction. However, it is unclear how mutations in these genes disrupt myosin structure and function leading to skeletal muscle myopathies termed myosinopathies. Here, we used multiple approaches to analyze the effects of common MYH7 and MYH2 mutations in the light meromyosin (LMM) region of myosin. Analyses of expressed and purified MYH7 and MYH2 LMM mutant proteins combined with in silico modeling showed that myosin coiled coil structure and packing of filaments in vitro are commonly disrupted. Using muscle biopsies from patients and fluorescent ATP analog chase protocols to estimate the proportion of myosin heads that were super-relaxed, together with x-ray diffraction measurements to estimate myosin head order, we found that basal myosin ATP consumption was increased and the myosin super-relaxed state was decreased in vivo. In addition, myofiber mechanics experiments to investigate contractile function showed that myofiber contractility was not affected. These findings indicate that the structural remodeling associated with LMM mutations induces a pathogenic state in which formation of shutdown heads is impaired, thus increasing myosin head ATP demand in the filaments, rather than affecting contractility. These key findings will help design future therapies for myosinopathies.
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| 4. |
- Drake, Mattias, et al.
(författare)
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Diffusion-Weighted Imaging, MR Angiography, and Baseline Data in a Systematic Multicenter Analysis of 3,301 MRI Scans of Ischemic Stroke Patients-Neuroradiological Review Within the MRI-GENIE Study
- 2020
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Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background:Magnetic resonance imaging (MRI) serves as a cornerstone in defining stroke phenotype and etiological subtype through examination of ischemic stroke lesion appearance and is therefore an essential tool in linking genetic traits and stroke. Building on baseline MRI examinations from the centralized and structured radiological assessments of ischemic stroke patients in the Stroke Genetics Network, the results of the MRI-Genetics Interface Exploration (MRI-GENIE) study are described in this work. Methods:The MRI-GENIE study included patients with symptoms caused by ischemic stroke (N= 3,301) from 12 international centers. We established and used a structured reporting protocol for all assessments. Two neuroradiologists, using a blinded evaluation protocol, independently reviewed the baseline diffusion-weighted images (DWIs) and magnetic resonance angiography images to determine acute lesion and vascular occlusion characteristics. Results:In this systematic multicenter radiological analysis of clinical MRI from 3,301 acute ischemic stroke patients according to a structured prespecified protocol, we identified that anterior circulation infarcts were most prevalent (67.4%), that infarcts in the middle cerebral artery (MCA) territory were the most common, and that the majority of large artery occlusions 0 to 48 h from ictus were in the MCA territory. Multiple acute lesions in one or several vascular territories were common (11%). Of 2,238 patients with unilateral DWI lesions, 52.6% had left-sided infarct lateralization (P= 0.013 for chi(2)test). Conclusions:This large-scale analysis of a multicenter MRI-based cohort of AIS patients presents a unique imaging framework facilitating the relationship between imaging and genetics for advancing the knowledge of genetic traits linked to ischemic stroke.
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| 5. |
- Frid, Petrea, et al.
(författare)
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Detailed phenotyping of posterior vs. anterior circulation ischemic stroke: a multi-center MRI study
- 2020
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Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 267, s. 649-658
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Tidskriftsartikel (refereegranskat)abstract
- Objective Posterior circulation ischemic stroke (PCiS) constitutes 20-30% of ischemic stroke cases. Detailed information about differences between PCiS and anterior circulation ischemic stroke (ACiS) remains scarce. Such information might guide clinical decision making and prevention strategies. We studied risk factors and ischemic stroke subtypes in PCiS vs. ACiS and lesion location on magnetic resonance imaging (MRI) in PCiS. Methods Out of 3,301 MRIs from 12 sites in the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Genetics Network (SiGN), we included 2,381 cases with acute DWI lesions. The definition of ACiS or PCiS was based on lesion location. We compared the groups using Chi-squared and logistic regression. Results PCiS occurred in 718 (30%) patients and ACiS in 1663 (70%). Diabetes and male sex were more common in PCiS vs. ACiS (diabetes 27% vs. 23%, p < 0.05; male sex 68% vs. 58%, p < 0.001). Both were independently associated with PCiS (diabetes, OR = 1.29; 95% CI 1.04-1.61; male sex, OR = 1.46; 95% CI 1.21-1.78). ACiS more commonly had large artery atherosclerosis (25% vs. 20%, p < 0.01) and cardioembolic mechanisms (17% vs. 11%, p < 0.001) compared to PCiS. Small artery occlusion was more common in PCiS vs. ACiS (20% vs. 14%, p < 0.001). Small artery occlusion accounted for 47% of solitary brainstem infarctions. Conclusion Ischemic stroke subtypes differ between the two phenotypes. Diabetes and male sex have a stronger association with PCiS than ACiS. Definitive MRI-based PCiS diagnosis aids etiological investigation and contributes additional insights into specific risk factors and mechanisms of injury in PCiS.
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| 6. |
- Frid, P., et al.
(författare)
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Migraine-associated common genetic variants confer greater risk of posterior vs. anterior circulation ischemic stroke☆
- 2022
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Ingår i: Journal of Stroke and Cerebrovascular Diseases. - : Elsevier BV. - 1052-3057. ; 31:8
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine potential genetic relationships between migraine and the two distinct phenotypes posterior circulation ischemic stroke (PCiS) and anterior circulation ischemic stroke (ACiS), we generated migraine polygenic risk scores (PRSs) and compared these between PCiS and ACiS, and separately vs. non-stroke control subjects. Methods: Acute ischemic stroke cases were classified as PCiS or ACiS based on lesion location on diffusion-weighted MRI. Exclusion criteria were lesions in both vascular territories or uncertain territory; supratentorial PCiS with ipsilateral fetal posterior cerebral artery; and cases with atrial fibrillation. We generated migraine PRS for three migraine phenotypes (any migraine; migraine without aura; migraine with aura) using publicly available GWAS data and compared mean PRSs separately for PCiS and ACiS vs. non-stroke control subjects, and between each stroke phenotype. Results: Our primary analyses included 464 PCiS and 1079 ACiS patients with genetic European ancestry. Compared to non-stroke control subjects (n=15396), PRSs of any migraine were associated with increased risk of PCiS (p=0.01–0.03) and decreased risk of ACiS (p=0.010–0.039). Migraine without aura PRSs were significantly associated with PCiS (p=0.008–0.028), but not with ACiS. When comparing PCiS vs. ACiS directly, migraine PRSs were higher in PCiS vs. ACiS for any migraine (p=0.001–0.010) and migraine without aura (p=0.032–0.048). Migraine with aura PRS did not show a differential association in our analyses. Conclusions: Our results suggest a stronger genetic overlap between unspecified migraine and migraine without aura with PCiS compared to ACiS. Possible shared mechanisms include dysregulation of cerebral vessel endothelial function.
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| 7. |
- Giese, A. K., et al.
(författare)
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White matter hyperintensity burden in acute stroke patients differs by ischemic stroke subtype
- 2020
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Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 95:1
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo examine etiologic stroke subtypes and vascular risk factor profiles and their association with white matter hyperintensity (WMH) burden in patients hospitalized for acute ischemic stroke (AIS).MethodsFor the MRI Genetics Interface Exploration (MRI-GENIE) study, we systematically assembled brain imaging and phenotypic data for 3,301 patients with AIS. All cases underwent standardized web tool-based stroke subtyping with the Causative Classification of Ischemic Stroke (CCS). WMH volume (WMHv) was measured on T2 brain MRI scans of 2,529 patients with a fully automated deep-learning trained algorithm. Univariable and multivariable linear mixed-effects modeling was carried out to investigate the relationship of vascular risk factors with WMHv and CCS subtypes.ResultsPatients with AIS with large artery atherosclerosis, major cardioembolic stroke, small artery occlusion (SAO), other, and undetermined causes of AIS differed significantly in their vascular risk factor profile (all p < 0.001). Median WMHv in all patients with AIS was 5.86 cm(3) (interquartile range 2.18-14.61 cm(3)) and differed significantly across CCS subtypes (p < 0.0001). In multivariable analysis, age, hypertension, prior stroke, smoking (all p < 0.001), and diabetes mellitus (p = 0.041) were independent predictors of WMHv. When adjusted for confounders, patients with SAO had significantly higher WMHv compared to those with all other stroke subtypes (p < 0.001).ConclusionIn this international multicenter, hospital-based cohort of patients with AIS, we demonstrate that vascular risk factor profiles and extent of WMH burden differ by CCS subtype, with the highest lesion burden detected in patients with SAO. These findings further support the small vessel hypothesis of WMH lesions detected on brain MRI of patients with ischemic stroke.
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| 8. |
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| 9. |
- Afifi, K., et al.
(författare)
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Features of intracranial hemorrhage in cerebral venous thrombosis
- 2020
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Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 267, s. 3292-3298
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Tidskriftsartikel (refereegranskat)abstract
- Background Cerebral venous thrombosis (CVT) is associated with intracranial hemorrhage. Aim To identify clinical and imaging features of CVT-associated intracranial hemorrhage. We hypothesized that higher clot burden would be associated with a higher risk of intracranial hemorrhage. Methods We performed a retrospective analysis of an international, multicenter cohort of patients with confirmed cerebral venous thrombosis who underwent computed tomography within 2 weeks of symptom onset. Clinical and imaging features were compared between patients with and without intracranial hemorrhage. Clot burden was assessed by counting the number of thrombosed venous sinuses and veins on confirmatory imaging. Results We enrolled 260 patients from 10 institutions in Europe and Mexico. The mean age was 42 years and 74% were female. Intracranial hemorrhage was found in 102 (39%). Among them parenchymal hemorrhage occurred in 64 (63%), in addition, small juxta-cortical hemorrhage was found in 30 (29%), subarachnoid hemorrhage in 24 (24%) and subdural hemorrhage in 11 (11%). Multiple concomitant types of hemorrhage occurred in 23 (23%). Older age and superior sagittal thrombosis involvement were associated with presence of hemorrhage. The number of thrombosed venous sinuses was not associated with intracranial hemorrhage (median number IQRInterquartile ratio] of sinuses/veins involved with hemorrhage 2 (1-3) vs. 2 (1-3) without hemorrhage,p = 0.4). Conclusion The high rate of intracranial hemorrhage in cerebral venous thrombosis is not explained by widespread involvement of the venous sinuses. Superior sagittal sinus involvement is associated with higher bleeding risk.
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| 10. |
- Bejanyan, Nelli, et al.
(författare)
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Myeloablative Conditioning for Allogeneic Transplantation Results in Superior Disease-Free Survival for Acute Myelogenous Leukemia and Myelodysplastic Syndromes with Low/Intermediate but not High Disease Risk Index : A Center for International Blood and Marrow Transplant Research Study
- 2021
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Ingår i: Transplantation and Cellular Therapy. - : Elsevier. - 2666-6375 .- 2666-6367. ; 27:1, s. 68.e1-68.e9
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Tidskriftsartikel (refereegranskat)abstract
- Compared with reduced-intensity conditioning (RIC), myeloablative conditioning (MAC) is generally associated with lower relapse risk after allogeneic hematopoietic cell transplantation (HCT) for acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS). However, disease-specific risk factors in AML/MDS can further inform when MAC and RIC may yield differential outcomes. We analyzed HCT outcomes stratified by the Disease Risk Index (DRI) in 4387 adults (age 40 to 65 years) to identify the impact of conditioning intensity. In the low/ intermediate-risk DRI cohort, RIC was associated with lower nonrelapse mortality (NRM) (hazard ratio [HR],.74; 95% confidence interval [CI],.62 to.88; P <.001) but significantly greater relapse risk (HR, 1.54; 95% CI, 1.35 to 1.76; P <.001) and thus inferior disease-free survival (DFS) (HR, 1.19; 95% CI, 1.07 to 1.33; P =.001). In the high/ very high-risk DRI cohort, RIC was associated with marginally lower NRM (HR,.83; 95% CI,.68 to 1.00; P =.051) and significantly higher relapse risk (HR, 1.23; 95% CI, 1.08 to 1.41; P =.002), leading to similar DFS using either RIC or MAC. These data support MAC over RIC as the preferred conditioning intensity for patients with AML/MDS with low/intermediate-risk DRI, but with a similar benefit as RIC in high/very high-risk DRI. Novel MAC regimens with less toxicity could benefit all patients, but more potent antineoplastic approaches are needed for the high/ very-high risk DRI group.
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