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- Bjerrum, Ole Weis, et al.
(författare)
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Thromboembolism prophylaxis in patients with Philadelphia-negative myeloproliferative neoplasms-Clinical practice among Nordic specialists
- 2018
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Ingår i: European Journal of Haematology. - : WILEY. - 0902-4441 .- 1600-0609. ; 100:5, s. 475-478
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) have higher risks of developing thromboembolisms compared to the general population. International guidelines on the management of MPNs therefore include recommendations concerning thromboembolism prophylaxis. In clinical practice, strict adherence to guidelines may be challenging and dependent on factors such as physician experience, outpatient clinic setting, and access to therapy; however, no data exist on physician adherence or patient compliance to thromboembolism prophylaxis in MPNs. Objectives: The Nordic Myeloproliferative Neoplasm Study Group (NMPN) performed a survey among Nordic hematology specialists with the aim of documenting the implementation of international recommendations in a region of Northern Europe with similar healthcare systems. Results: The study showed that Nordic specialists managed their patients in accordance with international guidelines concerning medical intervention, but to a lesser degree regarding the management of additional cardiovascular risk factors. The survey also drew attention to the common clinical dilemma of combining antiaggregatory agents with vitamin K antagonists (VKA), or novel oral anticoagulants (NOAC), as well as phlebotomy limits in female polycythemia vera patients. Conclusions: The results of this study highlight the importance of considering all risk factors for thrombosis and an optimal collaboration with the primary healthcare sector.
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- Carlbom, Lina, et al.
(författare)
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Pre-transplantation ³¹P-magnetic resonance spectroscopy for quality assessment of human pancreatic grafts : A feasibility study
- 2017
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Ingår i: Magnetic Resonance Imaging. - : Elsevier BV. - 0730-725X .- 1873-5894. ; 39, s. 98-102
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the feasibility of using (31)P-MRS for objective non-invasive quality assessment of human pancreas grafts prior to transplantation or islet isolation.Materials and methods: Pancreata from 5 human donors, 3 males and 2 females, aged 49-78years, with body mass index (BMI) 22-31kg/m(2), were included. Pancreata were perfused with histidine-tryptophan-ketoglutarate solution during procurement and stored in hypothermic condition (4°C) for 21-44h. During the period of hypothermic storage repeated spectra were obtained for each graft by (31)P-MRS (1.5Tesla) to measure the cold ischemia time (CIT) dependent changes of the phosphorous metabolites adenosine triphosphate (ATP), phosphomonoesters (PME), phosphodiesters (PDE) and inorganic phosphate (Pi), in the grafts. Graft temperature was measured immediately before and after MR-examination. Reference spectrum for non-viable tissue was obtained after graft exposure to room temperature.Results: PME/Pi, PDE/Pi and ATP/Pi spectral intensities ratios decreased with increasing CIT, reflecting the decreased viability of the grafts. PME/Pi ratio was the most discriminatory variable at prolonged CIT. (31)P-MRS could be performed without significantly increasing graft temperature.Conclusions: (31)P-MRS may provide quantitative parameters for evaluating graft viability ex vivo, and is a promising tool for objective non-invasive assessment of the quality of human pancreas grafts prior to transplantation or islet isolation.
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- Eckerbom, Per, 1974-, et al.
(författare)
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Multiparametric assessment of renal physiology in healthy volunteers using noninvasive magnetic resonance imaging
- 2019
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Ingår i: American Journal of Physiology - Renal Physiology. - : American Physiological Society. - 1931-857X .- 1522-1466. ; 316:4, s. F693-F702
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Tidskriftsartikel (refereegranskat)abstract
- Non-invasive methods of magnetic resonance imaging (MRI) can quantify parameters of kidney function. The main purpose of this study was to determine baseline values of such parameters in healthy volunteers. In 28 healthy volunteers (15 females, 13 males), Arterial Spin Labeling (ASL) to estimate regional renal perfusion, Blood Oxygen Level Dependent (BOLD) transverse relaxation rate (R2*) to estimate oxygenation, and Apparent Diffusion Coefficient (ADC), true diffusion (D) and longitudinal relaxation time (T1) to estimate tissue properties were determined bilaterally in the cortex, outer and inner medulla. Additionally, phase contrast (PC) MRI was applied in the renal arteries to quantify total renal blood flow. The results demonstrated profound gradients of perfusion, ADC and D with highest values in the kidney cortex and a decrease towards the inner medulla. R2* and T1 were lowest in kidney cortex and increased towards the inner medulla. Total renal blood flow correlated with body surface area, body mass index and renal volume. Similar patterns in all investigated parameters were observed in females and males. In conclusion, non-invasive MRI provides useful tools to evaluate intra renal differences in blood flow, perfusion, diffusion, oxygenation and structural properties of the kidney tissue. As such, this experimental approach has the potential to advance our current understanding regarding normal physiology and the pathological processes associated with acute and chronic kidney disease.
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- Eriksson, Jonas, et al.
(författare)
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Synthesis and preclinical evaluation of the CRTH2 antagonist [11C]MK-7246 as a novel PET tracer and potential surrogate marker for pancreatic beta-cell mass
- 2019
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 71, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: MK-7246 is a potent and selective antagonist for chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). Within the pancreas CRTH2 is selectively expressed in pancreatic β-cells where it is believed to play a role in insulin release. Reduction in β-cell mass and insufficient insulin secretion in response to elevated blood glucose levels is a hallmark for type 1 and type 2 diabetes. Reported here is the synthesis of [11C]MK-7246 and initial preclinical evaluation towards CRTH2 imaging. The aim is to develop a method to quantify β-cell mass with PET and facilitate non-invasive studies of disease progression in individuals with type 2 diabetes.Methods: The precursor N-desmethyl-O-methyl MK-7246 was synthesized in seven steps and subjected to methylation with [11C]methyl iodide followed by hydrolysis to obtain [11C]MK-7246 labelled in the N-methyl position. Preclinical evaluation included in vitro radiography and immune-staining performed in human pancreatic biopsies. Biodistribution studies were performed in rat by PET-MRI and in pig by PET-CT imaging. The specific tracer uptake was examined in pig by scanning before and after administration of MK-7246 (1 mg/kg). Predicted dosimetry of [11C]MK-7246 in human males was estimated based on the biodistribution in rat.Results: [11C]MK-7246 was obtained with activities sufficient for the current investigations (270±120 MBq) and a radiochemical purity of 93±2%. The tracer displayed focal binding in areas with insulin positive islet of Langerhans in human pancreas sections. Baseline uptake in pig was significantly reduced in CRTH2-rich areas after administration of MK-7246; pancreas (66% reduction) and spleen (88% reduction). [11C]MK-7246 exhibited a safe human predicted dosimetry profile as extrapolated from the rat biodistribution data.Conclusions: Initial preclinical in vitro and in vivo evaluation of [11C]MK-7246 show binding and biodistribution properties suitable for PET imaging of CRTH2. Further studies are warranted to assess its potential in β-cell mass imaging and CRTH2 drug development.
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| 8. |
- Espes, Daniel, 1985-, et al.
(författare)
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Pancreatic perfusion and its response to glucose as measured by simultaneous PET/MRI
- 2019
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Ingår i: Acta Diabetologica. - : Springer. - 0940-5429 .- 1432-5233. ; 56:10, s. 1113-1120
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Perfusion of the pancreas and the islets of Langerhans is sensitive to physiological stimuli and is dysregulated in metabolic disease. Pancreatic perfusion can be assessed by both positron emission tomography (PET) and magnetic resonance imaging (MRI), but the methods have not been directly compared or benchmarked against the gold-standard microsphere technique.METHODS: Pigs (n = 4) were examined by [15O]H2O PET and intravoxel incoherent motion (IVIM) MRI technique simultaneously using a hybrid PET/MRI scanner. The pancreatic perfusion was measured both at basal conditions and after intravenous (IV) administration of up to 0.5 g/kg glucose.RESULTS: Pancreatic perfusion increased by 35%, 157%, and 29% after IV 0.5 g/kg glucose compared to during basal conditions, as assessed by [15O]H2O PET, IVIM MRI, and microspheres, respectively. There was a correlation between pancreatic perfusion as assessed by [15O]H2O PET and IVIM MRI (r = 0.81, R2 = 0.65, p < 0.01). The absolute quantification of pancreatic perfusion (ml/min/g) by [15O]H2O PET was within a 15% error of margin of the microsphere technique.CONCLUSION: Pancreatic perfusion by [15O]H2O PET was in agreement with the microsphere technique assessment. The IVIM MRI method has the potential to replace [15O]H2O PET if the pancreatic perfusion is sufficiently large, but not when absolute quantitation is required.
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| 9. |
- Forsberg, Karin, et al.
(författare)
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Endothelial damage, vascular bagging and remodeling of the microvascular bed in human microangiopathy with deep white matter lesions
- 2018
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Ingår i: Acta neuropathologica communications. - : BioMed Central. - 2051-5960. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- White matter lesions (WMLs) are a common manifestation of small vessel disease (SVD) in the elderly population. They are associated with an enhanced risk of developing gait abnormalities, poor executive function, dementia, and stroke with high mortality. Hypoperfusion and the resulting endothelial damage are thought to contribute to the development of WMLs. The focus of the present study was the analysis of the microvascular bed in SVD patients with deep WMLs (DWMLs) by using double- and triple-label immunohistochemistry and immunofluorescence. Simultaneous visualization of collagen IV (COLL4)-positive membranes and the endothelial glycocalyx in thick sections allowed us to identify endothelial recession in different types of string vessels, and two new forms of small vessel/capillary pathology, which we called vascular bagging and ghost string vessels. Vascular bags were pouches and tubes that were attached to vessel walls and were formed by multiple layers of COLL4-positive membranes. Vascular bagging was most severe in the DWMLs of cases with pure SVD (no additional vascular brain injury, VBI). Quantification of vascular bagging, string vessels, and the density/size of CD68-positive cells further showed widespread pathological changes in the frontoparietal and/or temporal white matter in SVD, including pure SVD and SVD with VBI, as well as a significant effect of the covariate age. Plasma protein leakage into vascular bags and the white matter parenchyma pointed to endothelial damage and basement membrane permeability. Hypertrophic IBA1-positive microglial cells and CD68-positive macrophages were found in white matter areas covered with networks of ghost vessels in SVD, suggesting phagocytosis of remnants of string vessels. However, the overall vessel density was not altered in our SVD cohort, which might result from continuous replacement of vessels. Our findings support the view that SVD is a progressive and generalized disease process, in which endothelial damage and vascular bagging drive remodeling of the microvasculature.
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| 10. |
- Haas, Jan, et al.
(författare)
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Atlas of the clinical genetics of human dilated cardiomyopathy
- 2015
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Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 36:18, s. 1123-U43
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Tidskriftsartikel (refereegranskat)abstract
- Aim: We were able to show that targeted Next-Generation Sequencing is well suited to be applied in clinical routine diagnostics, substantiating the ongoing paradigm shift from low- to high-throughput genomics in medicine. By means of our atlas of the genetics of human DCM, we aspire to soon be able to apply our findings to the individual patient with cardiomyopathy in daily clinical practice. Numerous genes are known to cause dilated cardiomyopathy (DCM). However, until now technological limitations have hindered elucidation of the contribution of all clinically relevant disease genes to DCM phenotypes in larger cohorts. We now utilized next-generation sequencing to overcome these limitations and screened all DCM disease genes in a large cohort. Methods and results: In this multi-centre, multi-national study, we have enrolled 639 patients with sporadic or familial DCM. To all samples, we applied a standardized protocol for ultra-high coverage next-generation sequencing of 84 genes, leading to 99.1% coverage of the target region with at least 50-fold and a mean read depth of 2415. In this well characterized cohort, we find the highest number of known cardiomyopathy mutations in plakophilin-2, myosin-binding protein C-3, and desmoplakin. When we include yet unknown but predicted disease variants, we find titin, plakophilin-2, myosin-binding protein-C 3, desmoplakin, ryanodine receptor 2, desmocollin-2, desmoglein-2, and SCN5A variants among the most commonly mutated genes. The overlap between DCM, hypertrophic cardiomyopathy (HCM), and channelopathy causing mutations is considerably high. Of note, we find that >38% of patients have compound or combined mutations and 12.8% have three or even more mutations. When comparing patients recruited in the eight participating European countries we find remarkably little differences in mutation frequencies and affected genes. Conclusion: This is to our knowledge, the first study that comprehensively investigated the genetics of DCM in a large-scale cohort and across a broad gene panel of the known DCM genes. Our results underline the high analytical quality and feasibility of Next-Generation Sequencing in clinical genetic diagnostics and provide a sound database of the genetic causes of DCM.
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