1. |
- Habel, Joachim, et al.
(författare)
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Selecting analytical tools for characterization of polymersomes in aqueous solution
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 5:97, s. 79924-79946
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Forskningsöversikt (refereegranskat)abstract
- Selecting the appropriate analytical methods for characterizing the assembly and morphology of polymer-based vesicles, or polymersomes are required to reach their full potential in biotechnology. This work presents and compares 17 different techniques for their ability to adequately report size, lamellarity, elastic properties, bilayer surface charge, thickness and polarity of polybutadiene-polyethylene oxide (PB-PEO) based polymersomes. The techniques used in this study are broadly divided into scattering techniques, visualization methods, physical and electromagnetical manipulation and sorting/purification. Of the analytical methods tested, Cryo-transmission electron microscopy and atomic force microscopy (AFM) turned out to be advantageous for polymersomes with smaller diameter than 200 nm, whereas confocal microscopy is ideal for diameters >400 nm. Polymersomes in the intermediate diameter range can be characterized using freeze fracture Cryo-scanning electron microscopy (FF-Cryo-SEM) and nanoparticle tracking analysis (NTA). Small angle X-ray scattering (SAXS) provides reliable data on bilayer thickness and internal structure, Cryo-TEM on multilamellarity. Taken together, these tools are valuable for characterizing polymersomes per se but the comparative overview is also intended to serve as a starting point for selecting methods for characterizing polymersomes with encapsulated compounds or polymersomes with incorporated biomolecules (e.g. membrane proteins).
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2. |
- Hedegaard, Jakob, et al.
(författare)
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Comprehensive Transcriptional Analysis of Early-Stage Urothelial Carcinoma
- 2016
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Ingår i: Cancer Cell. - : Elsevier BV. - 1535-6108 .- 1878-3686. ; 30:1, s. 27-42
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Tidskriftsartikel (refereegranskat)abstract
- Non-muscle-invasive bladder cancer (NMIBC) is a heterogeneous disease with widely different outcomes. We performed a comprehensive transcriptional analysis of 460 early-stage urothelial carcinomas and showed that NMIBC can be subgrouped into three major classes with basal-and luminal-like characteristics and different clinical outcomes. Large differences in biological processes such as the cell cycle, epithelial-mesenchymal transition, and differentiation were observed. Analysis of transcript variants revealed frequent mutations in genes encoding proteins involved in chromatin organization and cytoskeletal functions. Furthermore, mutations in well-known cancer driver genes (e.g., TP53 and ERBB2) were primarily found in high-risk tumors, together with APOBEC-related mutational signatures. The identification of subclasses in NMIBC may offer better prognostication and treatment selection based on subclass assignment.
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3. |
- de Jong, Jasper M. A., et al.
(författare)
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Human brown adipose tissue is phenocopied by classical brown adipose tissue in physiologically humanized mice
- 2019
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Ingår i: Nature Metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 1:8, s. 830-843
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Tidskriftsartikel (refereegranskat)abstract
- Human and rodent brown adipose tissues (BAT) appear morphologically and molecularly different. Here we compare human BAT with both classical brown and brite/beige adipose tissues of 'physiologically humanized' mice: middle-aged mice living under conditions approaching human thermal and nutritional conditions, that is, prolonged exposure to thermoneutral temperature (approximately 30 degrees C) and to an energy-rich (high-fat, high-sugar) diet. We find that the morphological, cellular and molecular characteristics (both marker and adipose-selective gene expression) of classical brown fat, but not of brite/beige fat, of these physiologically humanized mice are notably similar to human BAT. We also demonstrate, both in silico and experimentally, that in physiologically humanized mice only classical BAT possesses a high thermogenic potential. These observations suggest that classical rodent BAT is the tissue of choice for translational studies aimed at recruiting human BAT to counteract the development of obesity and its comorbidities.
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4. |
- Diederichsen, Soren Z., et al.
(författare)
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Impact of fasting glucose on electrocardiographic left ventricular hypertrophy in an elderly general population
- 2015
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Ingår i: Blood Pressure. - : Informa UK Limited. - 0803-7051 .- 1651-1999. ; 24:3, s. 164-173
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To evaluate relationships between fasting plasma glucose (FPG), other cardiovascular risk markers and left ventricular hypertrophy (LVH) as detected by electrocardiography. Methods. Subjects were selected randomly from groups defi ned by FPG. Traditional risk markers were assessed. LVH was defi ned by either Cornell voltage -duration product (CP) or Sokolow -Lyon voltage combination (SL), and univariate and multivariable regressions were performed in search of explanatory factors for the presence of LVH and the values of CP and SL. Results. Of the 1759 subjects included, 1007 had a history of cardiovascular disease and/or medical treatment, while 752 subjects appeared to be healthy. We found an independent association between FPG and LVH (odds ratio 1.152, p = 0.042] as well as continuous CP (beta = 0.126, p = 0.007) in healthy men. As expected, we found an association between systolic blood pressure and LVH (odds ratio 1.020, p < 0.001) among healthy subjects, but only in subjects with FPG < 6 mmol/l (p = 0.04 for interaction). Conclusions. We found an independent association between FPG and LVH in healthy men, and no potentiating effect by FPG on the impact of hypertension.
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5. |
- Huber, Vincent J., et al.
(författare)
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Aquaporins : Chemical inhibition by small molecules
- 2016
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Ingår i: Aquaporins in Health and Disease : New Molecular Targets for Drug Discovery - New Molecular Targets for Drug Discovery. - 9781498707831 - 9781498707848 ; , s. 249-271
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Bokkapitel (refereegranskat)abstract
- The human genome encodes 13 aquaporin isoforms with characteristic substrate specificity that are expressed at specific locations throughout the body. Of these isoforms, AQPs 1-4 serve important functions in renal water reabsorption. Consequently, specific AQP inhibitors have been proposed as 'aquaretics', a new class of drugs suitable to induce diuresis without concomitant salt wasting. Furthermore, animal experiments suggested that AQP4 inhibitors could be useful to treat some forms of brain edema. Other proposed applications for AQP inhibitors involve amongst others treatment of diabetes, inflammatory skin diseases and cancer. However, few of these putative applications have been critically evaluated against current forms of therapy. Furthermore, development of AQP inhibitors remains difficult and despite numerous efforts during at least the last 15 years very few AQP inhibitors have been described. Moreover, none of the hitherto described substances have been developed to a level where meaningful verification of proposed AQP drug targets in preclinical or clinical settings was possible. Nonetheless, encouraging progress towards development of such substances has been made during recent years. Novel cell-based assays facilitate high throughput screening of chemical compound libraries for hit discovery. AQP 3D structures have been solved for 10 isoforms, which can support rapidly evolving computational hit discovery methods, as well as hit to lead programs. In this chapter, we will provide a critical review of current evidence supporting relevance of AQPs as drug targets, describe current methods for AQP inhibitor discovery and will try to highlight challenges that remain before successful AQP inhibitor development.
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6. |
- Lindskog, Cecilia, et al.
(författare)
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A Systematic Characterization of Aquaporin-9 Expression in Human Normal and Pathological Tissues
- 2016
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Ingår i: Journal of Histochemistry and Cytochemistry. - : SAGE Publications. - 0022-1554 .- 1551-5044. ; 64:5, s. 287-300
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Tidskriftsartikel (refereegranskat)abstract
- AQP9 is known to facilitate hepatocyte glycerol uptake. Murine AQP9 protein expression has been verified in liver, skin, epididymis, epidermis and neuronal cells using knockout mice. Further expression sites have been reported in humans. We aimed to verify AQP9 expression in a large set of human normal organs, different cancer types, rheumatoid arthritis synovial biopsies as well as in cell lines and primary cells. Combining standardized immunohistochemistry with high-throughput mRNA sequencing, we found that AQP9 expression in normal tissues was limited, with high membranous expression only in hepatocytes. In cancer tissues, AQP9 expression was mainly found in hepatocellular carcinomas, suggesting no general contribution of AQP9 to carcinogenesis. AQP9 expression in a subset of rheumatoid arthritis synovial tissue samples was affected by Humira, thereby supporting a suggested role of TNF alpha in AQP9 regulation in this disease. Among cell lines and primary cells, LP-1 myeloma cells expressed high levels of AQP9, whereas low expression was observed in a few other lymphoid cell lines. AQP9 mRNA and protein expression was absent in HepG2 hepatocellular carcinoma cells. Overall, AQP9 expression in human tissues appears to be more selective than in mice.
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7. |
- Nielsen-Kudsk, Jens Erik, et al.
(författare)
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Left atrial appendage occlusion versus standard medical care in patients with atrial fibrillation and intracerebral haemorrhage : a propensity score-matched follow-up study
- 2017
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Ingår i: EuroIntervention. - : EUROPA EDITION. - 1774-024X .- 1969-6213. ; 13:3, s. 371-378
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The aim of this study was to investigate the prognosis in patients with atrial fibrillation (AF) and intracerebral haemorrhage (ICH) having a left atrial appendage occlusion (LAAO) versus patients receiving standard medical therapy. Methods and results: A total of 151 patients from the Nordic countries with AF and previous ICH who underwent LAAO using the AMPLATZER Cardiac Plug or the AMPLATZER AMULET were compared to a propensity score-matched group of 151 patients receiving standard medical therapy. The two groups were matched so that their risks for stroke and bleeding were similar (CHA2DS2-VASc and HAS-BLED scores). The standard care patients were identified from the Danish Stroke Registry among 787 patients with AF and ICH. The primary endpoint was a composite of all-cause mortality, ischaemic stroke and major bleeding. Patients with AF and a prior ICH treated with LAAO had a lower risk of the composite outcome as compared to patients treated with standard medical care (events/1,000 years [95% confidence interval]: 53.3 [44.3-64.1] vs. 366.7 [298.2-450.9]; hazard ratio 0.16 [0.07-0.37]). Conclusions: LAAO is suggested to be of major clinical benefit in AF patients having sustained an ICH. These results have to be confirmed in a randomised clinical trial.
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8. |
- Nielsen, Roni, et al.
(författare)
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Cardiovascular Effects of Treatment With the Ketone Body 3-Hydroxybutyrate in Chronic Heart Failure Patients
- 2019
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Ingår i: Circulation. - : LIPPINCOTT WILLIAMS & WILKINS. - 0009-7322 .- 1524-4539. ; 139:18, s. 2129-2141
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myocardial utilization of 3-hydroxybutyrate (3-OHB) is increased in patients with heart failure and reduced ejection fraction (HFrEF). However, the cardiovascular effects of increased circulating plasma-3-OHB levels in these patients are unknown. Consequently, the authors' aim was to modulate circulating 3-OHB levels in HFrEF patients and evaluate: (1) changes in cardiac output (CO); (2) a potential doseresponse relationship between 3-OHB levels and CO; (3) the impact on myocardial external energy efficiency (MEE) and oxygen consumption (MVO 2); and (4) whether the cardiovascular response differed between HFrEF patients and age-matched volunteers.METHODS: Study 1: 16 chronic HFrEF patients (left ventricular ejection fraction: 37 +/- 3%) were randomized in a crossover design to 3-hour of 3-OHB or placebo infusion. Patients were monitored invasively with a Swan-Ganz catheter and with echocardiography. Study 2: In a doseresponse study, 8 HFrEF patients were examined at increasing 3-OHB infusion rates. Study 3 to 4: 10 HFrEF patients and 10 age-matched volunteers were randomized in a crossover design to 3-hour 3-OHB or placebo infusion. MEE and MVO 2 were evaluated using 11C-acetate positron emission tomography.RESULTS: 3-OHB infusion increased circulating levels of plasma 3-OHB from 0.4 +/- 0.3 to 3.3 +/- 0.4 mM (P< 0.001). CO rose by 2.0 +/- 0.2 L/min (P< 0.001) because of an increase in stroke volume of 20 +/- 2 mL (P< 0.001) and heart rate of 7 +/- 2 beats per minute (bpm) (P< 0.001). Left ventricular ejection fraction increased 8 +/- 1% (P< 0.001) numerically. There was a dose-response relationship with a significant CO increase of 0.3 L/min already at plasma-3-OHB levels of 0.7 mM (P< 0.001). 3-OHB increased MVO 2 without altering MEE. The response to 3-OHB infusion in terms of MEE and CO did not differ between HFrEF patents and age-matched volunteers.CONCLUSIONS: 3-OHB has beneficial hemodynamic effects in HFrEF patients without impairing MEE. These beneficial effects are detectable in the physiological concentration range of circulating 3-OHB levels. The hemodynamic effects of 3-OHB were observed in both HFrEF patients and age-matched volunteers. 3-OHB may potentially constitute a novel treatment principle in HFrEF patients.
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9. |
- Nyblom, Maria, et al.
(författare)
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Regulation of eukaryotic aquaporins
- 2016
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Ingår i: Aquaporins in Health and Disease : New Molecular Targets for Drug Discovery - New Molecular Targets for Drug Discovery. - 9781498707831 - 9781498707848 ; , s. 53-76
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Bokkapitel (refereegranskat)abstract
- Membrane-bound water channels known as aquaporins (AQPs) facilitate water transport across biological membranes along osmotic gradients. Since all living cells depend on their ability to maintain water homeostasis, this must be tightly regulated. In eukaryotes, this is achieved by gating, which involves a conformational change of the protein, thereby physically blocking water transport, or by trafficking in which AQPs are shuttled between intracellular storage sites and the plasma membrane. Gating is common amongst plant AQPs in response to environmental stress and has been shown to be triggered by phosphorylation, pH and binding of divalent cations. Gating has been demonstrated for yeast AQPs for which it is believed to confer protection against osmotic shock and rapid freezing. In mammals, AQP regulation is mainly achieved through trafficking. Thirteen AQPs have been identified in humans, the majority of which are regulated by trafficking in response to a wide range of stimuli. The far best characterized trafficking mechanism is that of AQP2 in the kidney collecting duct where it plays a key role in urine concentration. AQP2 trafficking is controlled by the pituitary hormone vasopressin that stimulates phosphorylation of the AQP2 C-terminus, triggering translocation of AQP2 from intracellular storage vesicles to the apical membrane. Defective trafficking of human AQPs can lead to several disease states, for example nephrogenic diabetes insipidus (AQP2) and Sjögren's syndrome (AQP5). In this chapter, we give an overview of what is known about the regulation of eukaryotic AQPs, focusing particularly on structure-function relationships. We discuss the physiological role of AQP regulation, specific regulatory mechanisms and reoccurring themes in both gating and trafficking.
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10. |
- Tolbod, Lars P., et al.
(författare)
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Non-invasive quantification of tumor blood flow in prostate cancer using O-15-H2O PET/CT
- 2018
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Ingår i: American Journal of Nuclear Medicine and Molecular Imaging. - : E-CENTURY PUBLISHING CORP. - 2160-8407. ; 8:5, s. 292-302
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Tidskriftsartikel (refereegranskat)abstract
- Tumor blood flow (TBF) measurements in prostate cancer (PCa) provide an integrative index of tumor growth, which could be important for primary diagnosis and therapy response evaluation. O-15-water PET is the noninvasive gold standard but is technically demanding. The aim of this study was to compare the accuracy of three different non-invasive strategies with an invasively measured arterial input function (BSIF): Using image-derived input functions (IDIF) from either 1) a separate heart scan or 2) the pelvic scan or 3) a populations-based input function (PBIF). Nine patients with biopsy-verified PCa scheduled for prostatectomy were included. All patients were characterized with serum levels of PSA (s-PSA), multiparametric magnetic resonance imaging (mpMRl) and post-surgical histopathology Gleason Grade. Dynamic O-15-water was performed of the heart and the pelvic area 15 minutes apart. TBF estimated from both wash-in (K-1) and wash-out (k(2)) constants was calculated using a one-compartmental model. Results: Mean (range) s PSA was 12 (3-27) ng/mL, Gleason Grade Group was 2.9 (1-5), k(2) was 0.44 (0.007-1.2), and K-1 was 0.24 (0.07-0.55) mL,/mL/min. k(2) (BSIF)correlated with s-PSA (r=0.86, P<0.01) and Gleason Grade Group (rho=0.78, P=0.01). BSIF, heart-IDIF and PBIF provided near-identical k(2) and K-1 (r>0.95, P<0.001) with slopes near unity. The correlations of BSIF and pelvic-IDIF rate constants were good (r>0.95, P<0.001), but individual errors high. In conclusion, non-invasive protocols for O-15-water PET with IDIF or PBIF accurately measures perfusion in prostate cancer and might be useful for evaluation of tumor aggressiveness and treatment response.
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