| 1. |
- Arner, Peter, et al.
(författare)
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Variations in the size of the major omentum are primarily determined by fat cell number
- 2013
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 98:5, s. E897-E901
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Accumulation of visceral adipose tissue (VAT) is strongly linked to insulin resistance. Variations in the size of any adipose depot are determined by alterations in adipocyte volume and/or number. The individual contribution of each of the latter factors was determined in the major omentum, a fully resectable VAT depot.SUBJECTS: Total removal of the major omentum (omentectomy) was performed in conjunction with bariatric surgery in 55 obese patients. Tissue weight as well as mean adipocyte size and number in the omentum were determined. In subgroups, total VAT was estimated by computerized tomography (n = 17) or dual-energy x-ray absorptiometry (n = 34).RESULTS: The weight of the major omentum (on average 0.6 kg) correlated significantly with total VAT mass estimated by computerized tomography or dual-energy x-ray absorptiometry (r = 0.48-0.7; P < .01). Omental weight in relation to total body fat correlated with several features of the metabolic syndrome and inversely with serum-leptin (P < .001). Mean adipocyte size and total adipocyte number correlated strongly with omental weight (r = 0.6-0.8; P < .0001), irrespective of body mass index and total body fat mass, and accounted almost in total for interindividual variations in omental size. However, stepwise regression analysis demonstrated that adipocyte number was significantly (P < .0001) more important (62%) than adipocyte size (35%).CONCLUSION: The size of the major omentum is representative for VAT mass and correlates with a pernicious metabolic profile. Variations in omental weight are primarily determined by adipocyte number and to a lesser degree by adipocyte size, suggesting that increased VAT mass in obesity is predominantly dependent on adipocyte proliferation.
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| 2. |
- Abé, Christoph, et al.
(författare)
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Cortical brain structure and sexual orientation in adult females with bipolar disorder or attention deficit hyperactivity disorder
- 2018
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Ingår i: Brain and Behavior. - : Wiley. - 2162-3279 .- 2162-3279. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nonheterosexual individuals have higher risk of psychiatric morbidity. Together with growing evidence for sexual orientation‐related brain differences, this raises the concern that sexual orientation may be an important factor to control for in neuroimaging studies of neuropsychiatric disorders.Methods: We studied sexual orientation in adult psychiatric patients with bipolar disorder (BD) or ADHD in a large clinical cohort (N = 154). We compared cortical brain structure in exclusively heterosexual women (HEW, n = 29) with that of nonexclusively heterosexual women (nHEW, n = 37) using surface‐based reconstruction techniques provided by FreeSurfer.Results: The prevalence of nonheterosexual sexual orientation was tentatively higher than reported in general population samples. Consistent with previously reported cross‐sex shifted brain patterns among homosexual individuals, nHEW patients showed significantly larger cortical volumes than HEW in medial occipital brain regions.Conclusion: We found evidence for a sex‐reversed difference in cortical volume among nonheterosexual female patients, which provides insights into the neurobiology of sexual orientation, and may provide the first clues toward a better neurobiological understanding of the association between sexual orientation and mental health. We also suggest that sexual orientation is an important factor to consider in future neuroimaging studies of populations with certain mental health disorders.
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| 3. |
- Abrahamsson, Niclas, et al.
(författare)
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Fördomar skadar många med fetma
- 2018
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Ingår i: Svenska Dagbladet Debatt. - 1101-2412.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Abreu-Vieira, Gustavo, et al.
(författare)
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Cidea improves the metabolic profile through expansion of adipose tissue
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- In humans, Cidea (cell death-inducing DNA fragmentation factor alpha-like effector A) is highly but variably expressed in white fat, and expression correlates with metabolic health. Here we generate transgenic mice expressing human Cidea in adipose tissues (aP2-hCidea mice) and show that Cidea is mechanistically associated with a robust increase in adipose tissue expandability. Under humanized conditions (thermoneutrality, mature age and prolonged exposure to high-fat diet), aP2-hCidea mice develop a much more pronounced obesity than their wild-type littermates. Remarkably, the malfunctioning of visceral fat normally caused by massive obesity is fully overcome-perilipin 1 and Akt expression are preserved, tissue degradation is prevented, macrophage accumulation is decreased and adiponectin expression remains high. Importantly, the aP2-hCidea mice display enhanced insulin sensitivity. Our data establish a functional role for Cidea and suggest that, in humans, the association between Cidea levels in white fat and metabolic health is not only correlative but also causative.
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| 5. |
- Anand, Sonia S, et al.
(författare)
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Rivaroxaban with or without aspirin in patients with stable peripheral or carotid artery disease: an international, randomised, double-blind, placebo-controlled trial.
- 2018
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Ingår i: Lancet (London, England). - 1474-547X. ; 391:10117, s. 219-229
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Tidskriftsartikel (refereegranskat)abstract
- Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mortality. Antiplatelet agents are widely used to reduce these complications.This was a multicentre, double-blind, randomised placebo-controlled trial for which patients were recruited at 602 hospitals, clinics, or community practices from 33 countries across six continents. Eligible patients had a history of peripheral artery disease of the lower extremities (previous peripheral bypass surgery or angioplasty, limb or foot amputation, intermittent claudication with objective evidence of peripheral artery disease), of the carotid arteries (previous carotid artery revascularisation or asymptomatic carotid artery stenosis of at least 50%), or coronary artery disease with an ankle-brachial index of less than 0·90. After a 30-day run-in period, patients were randomly assigned (1:1:1) to receive oral rivaroxaban (2·5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban twice a day (5 mg with aspirin placebo once a day), or to aspirin once a day (100 mg and rivaroxaban placebo twice a day). Randomisation was computer generated. Each treatment group was double dummy, and the patient, investigators, and central study staff were masked to treatment allocation. The primary outcome was cardiovascular death, myocardial infarction or stroke; the primary peripheral artery disease outcome was major adverse limb events including major amputation. This trial is registered with ClinicalTrials.gov, number NCT01776424, and is closed to new participants.Between March 12, 2013, and May 10, 2016, we enrolled 7470 patients with peripheral artery disease from 558 centres. The combination of rivaroxaban plus aspirin compared with aspirin alone reduced the composite endpoint of cardiovascular death, myocardial infarction, or stroke (126 [5%] of 2492 vs 174 [7%] of 2504; hazard ratio [HR] 0·72, 95% CI 0·57-0·90, p=0·0047), and major adverse limb events including major amputation (32 [1%] vs 60 [2%]; HR 0·54 95% CI 0·35-0·82, p=0·0037). Rivaroxaban 5 mg twice a day compared with aspirin alone did not significantly reduce the composite endpoint (149 [6%] of 2474 vs 174 [7%] of 2504; HR 0·86, 95% CI 0·69-1·08, p=0·19), but reduced major adverse limb events including major amputation (40 [2%] vs 60 [2%]; HR 0·67, 95% CI 0·45-1·00, p=0·05). The median duration of treatment was 21 months. The use of the rivaroxaban plus aspirin combination increased major bleeding compared with the aspirin alone group (77 [3%] of 2492 vs 48 [2%] of 2504; HR 1·61, 95% CI 1·12-2·31, p=0·0089), which was mainly gastrointestinal. Similarly, major bleeding occurred in 79 (3%) of 2474 patients with rivaroxaban 5 mg, and in 48 (2%) of 2504 in the aspirin alone group (HR 1·68, 95% CI 1·17-2·40; p=0·0043).Low-dose rivaroxaban taken twice a day plus aspirin once a day reduced major adverse cardiovascular and limb events when compared with aspirin alone. Although major bleeding was increased, fatal or critical organ bleeding was not. This combination therapy represents an important advance in the management of patients with peripheral artery disease. Rivaroxaban alone did not significantly reduce major adverse cardiovascular events compared with asprin alone, but reduced major adverse limb events and increased major bleeding.Bayer AG.
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| 6. |
- Arner, Erik, et al.
(författare)
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Adipocyte Turnover : Relevance to Human Adipose Tissue Morphology
- 2010
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 59:1, s. 105-109
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-Adipose tissue may contain few large adipocytes (hypertrophy) or many small adipocytes (hyperplasia). We investigated factors of putative importance for adipose tissue morphology. RESEARCH DESIGN AND METHODS-Subcutaneous adipocyte size and total fat mass were compared in 764 subjects with BMI 18-60 kg/m(2). A morphology value was defined as tire difference between the measured adipocyte volume and the expected volume given by a curved-line fit for a given body fat mass and was related to insulin values. In 35 subjects, in vivo adipocyte turnover was measured by exploiting incorporation of atmospheric C-14 into DNA. RESULTS-Occurrence of hyperplasia (negative morphology value) or hypertrophy (positive morphology value) was independent of sex and body weight but con-elated with fasting plasma insulin levels and insulin sensitivity, independent of adipocyte volume (beta-coefficient = 0.3, P < 0.0001). Total adipocyte number and morphology were negatively related (r = -0.66); i.e., the total adipocyte number was greatest in pronounced hyperplasia and smallest in pronounced hypertrophy. The absolute number of new adipocytes generated each year was 70% lower (P < 0.001) in hypertrophy than in hyperplasia, and individual values for adipocyte generation and morphology were strongly related (r = 0.7, P < 0.001). The relative death rate (similar to 10% per year) or mean age of adipocytes (similar to 10 years) was not correlated with morphology. CONCLUSIONS-Adipose tissue morphology correlates with insulin measures and is linked to the total adipocyte number independently of sex and body fat level. Low generation rates of adipocytes associate with adipose tissue hypertrophy, whereas high generation rates associate with adipose hyperplasia. Diabetes 59:105-109, 2010
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| 7. |
- Arner, Peter, et al.
(författare)
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Dynamics of human adipose lipid turnover in health and metabolic disease
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 478:7367, s. 110-113
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Tidskriftsartikel (refereegranskat)abstract
- Adipose tissue mass is determined by the storage and removal of triglycerides in adipocytes(1). Little is known, however, about adipose lipid turnover in humans in health and pathology. To study this in vivo, here we determined lipid age by measuring (14)C derived from above ground nuclear bomb tests in adipocyte lipids. We report that during the average ten-year lifespan of human adipocytes, triglycerides are renewed six times. Lipid age is independent of adipocyte size, is very stable across a wide range of adult ages and does not differ between genders. Adipocyte lipid turnover, however, is strongly related to conditions with disturbed lipid metabolism. In obesity, triglyceride removal rate (lipolysis followed by oxidation) is decreased and the amount of triglycerides stored each year is increased. In contrast, both lipid removal and storage rates are decreased in non-obese patients diagnosed with the most common hereditary form of dyslipidaemia, familial combined hyperlipidaemia. Lipid removal rate is positively correlated with the capacity of adipocytes to break down triglycerides, as assessed through lipolysis, and is inversely related to insulin resistance. Our data support a mechanism in which adipocyte lipid storage and removal have different roles in health and pathology. High storage but low triglyceride removal promotes fat tissue accumulation and obesity. Reduction of both triglyceride storage and removal decreases lipid shunting through adipose tissue and thus promotes dyslipidaemia. We identify adipocyte lipid turnover as a novel target for prevention and treatment of metabolic disease.
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| 8. |
- Baeckdahl, Jesper, et al.
(författare)
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Spatial mapping reveals human adipocyte subpopulations with distinct sensitivities to insulin
- 2021
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Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 33:9, s. 1869-
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Tidskriftsartikel (refereegranskat)abstract
- The contribution of cellular heterogeneity and architecture to white adipose tissue (WAT) function is poorly understood. Herein, we combined spatially resolved transcriptional profiling with single-cell RNA sequencing and image analyses to map human WAT composition and structure. This identified 18 cell classes with unique propensities to form spatially organized homo-and heterotypic clusters. Of these, three constituted mature adipocytes that were similar in size, but distinct in their spatial arrangements and transcriptional profiles. Based on marker genes, we termed these Adipo(LEP), Adipo(PLIN), and Adipo(SAA). We confirmed, in independent datasets, that their respective gene profiles associated differently with both adipocyte and whole-body insulin sensitivity. Corroborating our observations, insulin stimulation in vivo by hyperinsulinemic-euglycemic clamp showed that only Adipo(PLIN) displayed a transcriptional response to insulin. Altogether, by mining this multimodal resource we identify that human WAT is composed of three classes of mature adipocytes, only one of which is insulin responsive.
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| 9. |
- Bergström, Maria, et al.
(författare)
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Lectin affinity capillary electrophoresis in glycoform analysis applying the partial filling technique
- 2004
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Ingår i: Journal of chromatography. B. - : Elsevier BV. - 1570-0232 .- 1873-376X. ; 809:2, s. 323-329
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Tidskriftsartikel (refereegranskat)abstract
- The study of protein glycosylation and its significance in biological interactions is a field of growing interest. This work demonstrates a lectin-based separation of protein glycoforms of α1-acid glycoprotein (AGP or orosomucoid) with capillary electrophoresis. Glycoform analysis was performed with a "partial filling technique" with the lectin Concanavalin A (Con A) as affinity ligand. Con A separated human AGP into two peaks, the first peak included AGP glycoforms without biantennary glycans, and the second peak represented the fraction that had one or more biantennary glycans. The applicability of the method was demonstrated with the analysis of AGP from clinical samples and AGP treated with N-glycosidase F. The AGP separation was also used as a reporter system to estimate the dissociation constant (KD) between Con A and a competing sugar. © 2004 Elsevier B.V. All rights reserved.
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| 10. |
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| 11. |
- Boekel, Jorrit, et al.
(författare)
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Comparative tissue transcriptomics reveal prompt inter-organ communication in response to local bacterial kidney infection
- 2011
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 12, s. 123-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mucosal infections elicit inflammatory responses via regulated signaling pathways. Infection outcome depends strongly on early events occurring immediately when bacteria start interacting with cells in the mucosal membrane. Hitherto reported transcription profiles on host-pathogen interactions are strongly biased towards in vitro studies. To detail the local in vivo genetic response to infection, we here profiled host gene expression in a recent experimental model that assures high spatial and temporal control of uropathogenic Escherichia coli (UPEC) infection within the kidney of a live rat. Results: Transcriptional profiling of tissue biopsies from UPEC-infected kidney tissue revealed 59 differentially expressed genes 8 h post-infection. Their relevance for the infection process was supported by a Gene Ontology (GO) analysis. Early differential expression at 3 h and 5 h post-infection was of low statistical significance, which correlated to the low degree of infection. Comparative transcriptomics analysis of the 8 h data set and online available studies of early local infection and inflammation defined a core of 80 genes constituting a "General tissue response to early local bacterial infections". Among these, 25% were annotated as interferon-gamma (IFN-gamma) regulated. Subsequent experimental analyses confirmed a systemic increase of IFN-gamma in rats with an ongoing local kidney infection, correlating to splenic, rather than renal Ifng induction and suggested this inter-organ communication to be mediated by interleukin (IL)-23. The use of comparative transcriptomics allowed expansion of the statistical data handling, whereby relevant data could also be extracted from the 5 h data set. Out of the 31 differentially expressed core genes, some represented specific 5 h responses, illustrating the value of comparative transcriptomics when studying the dynamic nature of gene regulation in response to infections. Conclusion: Our hypothesis-free approach identified components of infection-associated multi-cellular tissue responses and demonstrated how a comparative analysis allows retrieval of relevant information from lower-quality data sets. The data further define marked representation of IFN-gamma responsive genes and a prompt inter-organ communication as a hallmark of an early local tissue response to infection.
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| 12. |
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| 13. |
- Fabian, Botond, et al.
(författare)
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Diagnostic challenges in patients with reninomas and extrarenal renin-producing tumours
- 2024
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Ingår i: Clinical Endocrinology. - 0300-0664 .- 1365-2265.
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Forskningsöversikt (refereegranskat)abstract
- Renin-secreting tumours are rare causes of secondary hypertension and hypokalaemia. They are usually surgically curable, hence proper diagnostic work-up and tumour localisation is essential. In this paper, we present three Swedish patients recently diagnosed with renin secreting tumours, two with reninomas and one with an extrarenal renin-producing tumour, to illustrate diagnostic challenges. We also discuss the biochemical work-up, the pros and cons of different imaging techniques (computer tomography [CT], magnetic resonance imaging and [18F]fluorodeoxyglucose-positron emission tomography-CT), as well as how renal vein sampling (RVC) may contribute to localisation of the tumour.
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| 14. |
- Flanagan, John N., et al.
(författare)
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Role of follistatin in promoting adipogenesis in women
- 2009
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 94:8, s. 3003-9
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Follistatin is a glycoprotein that binds and neutralizes biological activities of TGFbeta superfamily members including activin and myostatin. We previously identified by expression profiling that follistatin levels in white adipose tissue (WAT) were regulated by obesity. OBJECTIVE: The objective of the study was to elucidate the role of follistatin in human WAT and obesity. DESIGN: We measured secreted follistatin protein from WAT biopsies and fat cells in vitro. We also quantified follistatin mRNA expression in sc and visceral WAT and in WAT-fractionated cells and related it to obesity status, body region, and cellular origin. We investigated the effects of follistatin on adipocyte differentiation of progenitor cells in vitro. PARTICIPANTS: Women (n = 66) with a wide variation in body mass index were recruited by advertisement and from a clinic for weight-reduction therapy. RESULTS: WAT secreted follistatin in vitro. Follistatin mRNA levels in sc but not visceral WAT were decreased in obesity and restored to nonobese levels after weight reduction. Follistatin mRNA levels were high in the stroma-vascular fraction of WAT and low in adipocytes. Recombinant follistatin treatment promoted adipogenic differentiation of progenitor cells and neutralized the inhibitory action of myostatin on differentiation in vitro. Moreover, activin and myostatin signaling receptors were detected in WAT and adipocytes. CONCLUSION: Follistatin is a new adipokine important for adipogenesis. Down-regulated WAT expression of follistatin in obesity may counteract adiposity but could, by inhibiting adipogenesis, contribute to hypertrophic obesity (large fat cells) and insulin resistance.
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| 15. |
- Göransson, Olga, et al.
(författare)
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Dimethylaminopurine inhibits metabolic effects of insulin in primary adipocytes.
- 2004
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Ingår i: Journal of Nutritional Biochemistry. - : Elsevier BV. - 1873-4847 .- 0955-2863. ; 15:5, s. 303-312
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Tidskriftsartikel (refereegranskat)abstract
- Dimethylaminopurine (DMAP) has previously been used as an inhibitor of phosphorylation in studies of meiotic events, and more recently to investigate TNFα signaling, because of its potential to inhibit activation of c-jun N-terminal kinase (JNK). Here we have addressed the effects of DMAP on metabolic insulin responses in adipocytes and on intracellular insulin signaling molecules. At 100 μmol/L, DMAP completely inhibited the ability of insulin to counteract lipolysis in isolated adipocytes. Insulin-induced lipogenesis and glucose uptake was inhibited to a lesser degree in a concentration-dependent manner starting at 10 μmol/L DMAP. Insulin-induced tyrosine phosphorylation of the insulin receptor was not affected by DMAP. Insulin-induced activation of protein kinase B, a known mediator of insulin action, was not inhibited by 100 μmol/L, but to a low extent by 1 mmol/L DMAP in intact cells. This inhibition was not sufficient to affect activation of the downstream protein kinase B substrate phosphodiesterase 3B. The inhibition of activation of JNK as a possible mechanism whereby DMAP affects insulin-induced antilipolysis, lipogenesis, and glucose uptake, was investigated using the JNK inhibitor SP600125. At 100 μmol/L, SP600125 completely reversed the antilipolytic effect of insulin, as well as partially inhibited insulin-induced lipogenesis and glucose-uptake, indicating that JNK may be involved in mediating these actions of insulin. Inhibition of JNK by DMAP may therefore partly explain the negative impact of DMAP on insulin action in adipocytes.
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| 16. |
- Jensen, Christina, et al.
(författare)
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Permissive roles of hematopoietin and cytokine tyrosine kinase receptors in early T-cell development
- 2008
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 111:4, s. 2083-2090
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Tidskriftsartikel (refereegranskat)abstract
- Although several cytokines have been demonstrated to be critical regulators of development of multiple blood cell lineages, it remains disputed to what degree they act through instructive or permissive mechanisms. Signaling through the FMS-like tyrosine kinase 3 (FLT3) receptor and the hematopoietin IL-7 receptor alpha (IL-7Ralpha) has been demonstrated to be of critical importance for sustained thymopoiesis. Signaling triggered by IL-7 and thymic stromal lymphopoietin (TSLP) is dependent on IL-7Ralpha, and both ligands have been implicated in T-cell development. However, we demonstrate that, whereas thymopoiesis is abolished in adult mice doubly deficient in IL-7 and FLT3 ligand (FLT3L), TSLP does not play a key role in IL-7-independent or FLT3L-independent T lymphopoiesis. Furthermore, whereas previous studies implicated that the role of other cytokine tyrosine kinase receptors in T lymphopoiesis might not involve permissive actions, we demonstrate that ectopic expression of BCL2 is sufficient not only to partially correct the T-cell phenotype of Flt3l(-/-) mice but also to rescue the virtually complete loss of all discernable stages of early T lymphopoiesis in Flt3l(-/-)Il7r(-/-) mice. These findings implicate a permissive role of cytokine receptors of the hematopoietin and tyrosine kinase families in early T lymphopoiesis.
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| 17. |
- Jiao, Hong, et al.
(författare)
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Genetic Association and Gene Expression Analysis Identify FGFR1 as a New Susceptibility Gene for Human Obesity
- 2011
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 96:6, s. E962-E966
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Tidskriftsartikel (refereegranskat)abstract
- Context: Previous studies suggest a role for fibroblast growth factor receptor 1 (FGFR1) in the regulation of energy balance. Objective: Our objective was to investigate whether FGFR1 is an obesity gene by genetic association and functional studies. Design: The study was designed to genotype common FGFR1 single-nucleotide polymorphisms (SNP) in large cohorts, confirm significant results in additional cohorts, and measure FGFR1 expression in human adipose tissue and in rodent hypothalamus. Setting: General community and referral centers for specialized care was the setting for the study. Participants: We genotyped FGFR1 SNP in 2438 obese and 2115 lean adults and 985 obese and 532 population-based children. Results were confirmed in 928 obese and 2738 population-based adults and 487 obese and 441 lean children. Abdominal sc adipose tissue was investigated in 202 subjects. We also investigated diet-induced, obese fasting, and fed rats. Main Outcome Measures: We analyzed the association between FGFR1 SNP and obesity. In secondary analyses, we related adipose FGFR1 expression to genotype, obesity, and degree of fat cell differentiation and related hypothalamic FGFR1 to energy balance. Results: FGFR1 rs7012413*T was nominally associated with obesity in all four cohorts; metaanalysis odds ratio = 1.17 (95% confidence interval = 1.10-1.25), and P = 1.8 x 10(-6), which was P = 7.0 x 10(-8) in the recessive model. rs7012413*T was associated with FGFR1 expression in adipose tissue (P < 0.0001). In this organ, but not in skeletal muscle, FGFR1 mRNA (P < 0.0001) and protein (P < 0.05) were increased in obesity. In rats, hypothalamic expression of FGFR1 declined after fasting (P < ]0.001) and increased after diet-induced obesity (P < 0.05). Conclusions: FGFR1 is a novel obesity gene that may promote obesity by influencing adipose tissue and the hypothalamic control of appetite.
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| 18. |
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| 19. |
- Massier, Lucas, et al.
(författare)
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An integrated single cell and spatial transcriptomic map of human white adipose tissue
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Single-cell studies of human white adipose tissue (WAT) provide insights into the specialized cell types in the tissue. Here the authors combine publicly available and newly generated high-resolution and bulk transcriptomic results from multiple human datasets to provide a comprehensive cellular map of white adipose tissue. To date, single-cell studies of human white adipose tissue (WAT) have been based on small cohort sizes and no cellular consensus nomenclature exists. Herein, we performed a comprehensive meta-analysis of publicly available and newly generated single-cell, single-nucleus, and spatial transcriptomic results from human subcutaneous, omental, and perivascular WAT. Our high-resolution map is built on data from ten studies and allowed us to robustly identify >60 subpopulations of adipocytes, fibroblast and adipogenic progenitors, vascular, and immune cells. Using these results, we deconvolved spatial and bulk transcriptomic data from nine additional cohorts to provide spatial and clinical dimensions to the map. This identified cell-cell interactions as well as relationships between specific cell subtypes and insulin resistance, dyslipidemia, adipocyte volume, and lipolysis upon long-term weight changes. Altogether, our meta-map provides a rich resource defining the cellular and microarchitectural landscape of human WAT and describes the associations between specific cell types and metabolic states.
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| 20. |
- Nasr, Patrik, et al.
(författare)
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A rapid, non-invasive, clinical surveillance for CachExia, sarcopenia, portal hypertension, and hepatocellular carcinoma in end-stage liver disease : the ACCESS-ESLD study protocol
- 2023
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Ingår i: BMC Gastroenterology. - : BioMed Central (BMC). - 1471-230X. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Liver cirrhosis, the advanced stage of many chronic liver diseases, is associated with escalated risks of liver-related complications like decompensation and hepatocellular carcinoma (HCC). Morbidity and mortality in cirrhosis patients are linked to portal hypertension, sarcopenia, and hepatocellular carcinoma. Although conventional cirrhosis management centered on treating complications, contemporary approaches prioritize preemptive measures. This study aims to formulate novel blood- and imaging-centric methodologies for monitoring liver cirrhosis patients.METHODS: In this prospective study, 150 liver cirrhosis patients will be enrolled from three Swedish liver clinics. Their conditions will be assessed through extensive blood-based markers and magnetic resonance imaging (MRI). The MRI protocol encompasses body composition profile with Muscle Assement Score, portal flow assessment, magnet resonance elastography, and a abbreviated MRI for HCC screening. Evaluation of lifestyle, muscular strength, physical performance, body composition, and quality of life will be conducted. Additionally, DNA, serum, and plasma biobanking will facilitate future investigations.DISCUSSION: The anticipated outcomes involve the identification and validation of non-invasive blood- and imaging-oriented biomarkers, enhancing the care paradigm for liver cirrhosis patients. Notably, the temporal evolution of these biomarkers will be crucial for understanding dynamic changes.TRIAL REGISTRATION: Clinicaltrials.gov, registration identifier NCT05502198. Registered on 16 August 2022. Link: https://classic. CLINICALTRIALS: gov/ct2/show/NCT05502198 .
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| 21. |
- Nylander, Elin, et al.
(författare)
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Five-year outcomes of ADHD diagnosed in adulthood.
- 2021
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Ingår i: Scandinavian journal of psychology. - : Wiley. - 1467-9450 .- 0036-5564. ; 62:1, s. 13-24
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Tidskriftsartikel (refereegranskat)abstract
- There is a dearth of long-term follow-up studies of adults diagnosed with ADHD. Here, the aim was to evaluate long-term outcomes in a group of ADHD patients diagnosed in adulthood and receiving routine psychiatric health care. Adults diagnosed with any type of ADHD (n=52) and healthy controls (n=73) were assessed at baseline and at a 5-year follow-up, using Global Assessment of Functioning (GAF), Clinical Global Impression (CGI), Brown ADD Scale (BADDS) and Adult ADHD Self-Report Scale (ASRS). A multivariate regression method was used to identify factors predicting 5-year outcomes, including baseline ratings, medication intensity, comorbidity, intelligence quotient (IQ), age, and sex. After 5years, ADHD patients reported fewer and/or less severe symptoms compared to baseline, but remained at clinically significant symptom levels and with functional deficits. Baseline self-reports of ADHD symptoms predicted their own 5-year outcome and low baseline functioning level predicted improved global functioning at follow-up. Factors previously reported to predict short-term outcomes (i.e., medication, comorbidity, IQ, age, and sex) did not anticipate long-term outcomes in present study.
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| 22. |
- Nylander, Elin, et al.
(författare)
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The Quantified Behavioural Test Plus (QbTest plus ) in adult ADHD
- 2023
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Ingår i: Nordic Psychology. - : Informa UK Limited. - 1901-2276 .- 1904-0016. ; 75:1, s. 20-34
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Tidskriftsartikel (refereegranskat)abstract
- The Quantified Behavioural Test Plus (QbTest+) is widely used in clinical practice to assess patients with attention-deficit hyperactivity disorder (ADHD). This study mapped its behaviour in a group of adults with ADHD. Does it signal problems with impulsivity, attention and/or activity? To what extent are patients' self-reported problems reflected in QbTest performance? Does Qb testing foretell the future, as reflected in the patients' and clinicians' judgements 4 years later? We here recorded the three QbTest+ cardinals-QbActivity, QbImpulsivity and QbInattention - in 67 consecutive ADHD patients diagnosed in adulthood. Among the 54 patients who medicated as usual on the day of testing, 35 (65%) scored above the clinical cut-off (Q-score >= 1.25) on at least one of the QbTest+ cardinals. Out of the 13 patients who suspended medication prior to the test, 11 (85%) scored above the clinical cut-off on at least one of the Qb-variables. There were modest associations between QbTest+ cardinals and symptom self-ratings [Brown ADD scale (BADDS); Adult Self-Report Scale (ASRS)]. Forty-one patients completed a second QbTest+ approximately 4 years after the first. Performance was improved on the follow-up test and fewer patients scored in the clinical range (34%). The scores on the QbInattention cardinal at baseline correlated positively with BADDS and ASRS self-ratings at the 4-year follow-up.
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| 23. |
- Olauson, Jon, 1980-, et al.
(författare)
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Simulating intra-hourly wind power fluctuations on a power system level
- 2017
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Ingår i: Wind Energy. - : Wiley. - 1095-4244 .- 1099-1824. ; 20:6, s. 973-985
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Tidskriftsartikel (refereegranskat)abstract
- In wind integration studies, sub-hourly, load synchronous wind data are often preferable. These datasets can be generatedby a hybrid approach, combining hourly measurements or output from meteorological models with a stochastic simulationof the high-frequency fluctuations. This paper presents a method for simulating aggregated intra-hourly wind power fluc-tuations for a power system, taking into account the time-varying volatility seen in measurements. Some key elements inthe modelling were transformations to stationarity, the use of frequency domain techniques including a search for appropri-ate phase angles and an adjustment of the resulting time series in order to get correct hourly means. Generation data fromDenmark and Germany with 5 and 15 min temporal resolution were used for training models. It is shown that the distribu-tion and non-stationarity of simulated deviations from hourly means closely follow those of measurements. Power spectraldensities and step change distributions agree well. Of particular importance is that the results are good also when the train-ing and objective power systems are not the same. The computational cost is low in comparison with other approaches forgenerating high-frequency data.
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| 24. |
- Petrus, Paul, et al.
(författare)
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Saturated fatty acids in human visceral adipose tissue are associated with increased 11-beta-hydroxysteroid-dehydrogenase type 1 expression
- 2015
-
Ingår i: Lipids in Health and Disease. - : Springer Science and Business Media LLC. - 1476-511X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Visceral fat accumulation is associated with metabolic disease. It is therefore relevant to study factors that regulate adipose tissue distribution. Recent data shows that overeating saturated fatty acids promotes greater visceral fat storage than overeating unsaturated fatty acids. Visceral adiposity is observed in states of hypercortisolism, and the enzyme 11-beta-hydroxysteroid-dehydrogenase type 1 (11 beta-hsd1) is a major regulator of cortisol activity by converting inactive cortisone to cortisol in adipose tissue. We hypothesized that tissue fatty acid composition regulates body fat distribution through local effects on the expression of 11 beta-hsd1 and its corresponding gene (HSD11B1) resulting in altered cortisol activity. Findings: Visceral- and subcutaneous adipose tissue biopsies were collected during Roux-en-Y gastric bypass surgery from 45 obese women (BMI; 41 +/- 4 kg/m(2)). The fatty acid composition of each biopsy was measured and correlated to the mRNA levels of HSD11B1. 11 beta-hsd1 protein levels were determined in a subgroup (n = 12) by western blot analysis. Our main finding was that tissue saturated fatty acids (e.g. palmitate) were associated with increased 11 beta-hsd1 gene- and protein-expression in visceral but not subcutaneous adipose tissue. Conclusions: The present study proposes a link between HSD11B1 and saturated fatty acids in visceral, but not subcutaneous adipose tissue. Nutritional regulation of visceral fat mass through HSD11B1 is of interest for the modulation of metabolic risk and warrants further investigation.
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| 25. |
- Pettersson, Amanda T, et al.
(författare)
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Twist1 in human white adipose tissue and obesity.
- 2011
-
Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 96:1, s. 133-41
-
Tidskriftsartikel (refereegranskat)abstract
- Twist1 is a transcription factor implicated in the regulation of TNFα signaling and was recently shown to be highly expressed in both human and murine adipose tissue, but its role in obesity is unknown.
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| 26. |
- Pettersson, Ulrika, 1981-
(författare)
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Blood Flow Regulation and Inflammatory Response in Experimental Models of Diabetes
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 2 diabetes is caused by defect pancreatic islet β-cells together with peripheral insulin resistance. The disease is often accompanied by obesity with associated low-grade visceral adipose tissue inflammation, which contributes to insulin resistance. As a consequence of, and a possible compensation for the increased insulin demand, blood flow to the pancreatic islets is increased in animal models of diabetes. This increased blood perfusion might with time affect the vascular network as well as β-cells within the islets. This thesis investigates the role of changes of blood perfusion in pancreatic islets and adipose tissues, as well as the recruitment to and composition of leukocyte subpopulations in insulin-sensitive tissues in experimental models of diabetes. Blood flow measurements in islets and adipose tissues of rats and mice were performed using the microsphere technique, while leukocyte recruitment was studied in the mouse cremaster muscle using intravital microscopy. Increased islet blood flow was observed in the GK rat model of type 2 diabetes, which was decreased by acute as well as continuous 2-week inhibition of β3-adrenoceptors without affecting plasma insulin concentrations. Increased inflammatory leukocyte recruitment was observed in both alloxan-induced and high-fat diet-induced diabetes. However, an impaired bacterial clearance was observed in diabetic mice, which was due to impaired phagocytosis. A gender difference was detected in mice fed a high-fat diet, since obese female mice did not show increased levels of pro-inflammatory circulatory markers or inflammatory leukocytes in the adipose tissue. The main effector cell in the adipose tissue inflammation in high-fat-fed male mice seemed to be the pro-inflammatory macrophage. The Treg population in adipose tissue was increased in female mice, but remained unchanged in male mice on high-fat diet. In conclusion, increased islet blood flow in type 2 diabetes could be reversed by β3-adrenoceptor inhibition, which may maintain islet function. The diabetes-associated hyperglycemia activated leukocytes but impaired their phagocytic ability. High-fat-fed female mice showed less peripheral inflammation due to a smaller number of recruited inflammatory macrophages and a high-fat diet-induced Treg population in intra-abdominal adipose tissues.
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| 27. |
- Pålsson, Erik, 1975, et al.
(författare)
-
Cerebrospinal fluid monoamine metabolite profiles in bipolar disorder, ADHD, and controls.
- 2017
-
Ingår i: Journal of neural transmission (Vienna, Austria : 1996). - : Springer Science and Business Media LLC. - 1435-1463 .- 0300-9564. ; 124:9
-
Tidskriftsartikel (refereegranskat)abstract
- Alterations in monoaminergic signaling are suggested as key aspects of the pathophysiology in bipolar disorder and ADHD, but it is not known if the monoamine metabolic profile differs between these disorders. One method to study monoaminergic systems in humans is to measure monoamine end-point metabolite concentrations in cerebrospinal fluid (CSF). Here, we analyzed CSF monoamine metabolite concentrations in 103 adults with bipolar disorder, 72 adults with ADHD, and 113 controls. Individuals with bipolar disorder had significantly higher homovanillic acid (HVA, 264±112nmol/L, p<0.001) and 5-hydroxyindoleacetic acid (5-HIAA, 116±42nmol/L, p=0.001) concentration, but lower 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG, 38±8nmol/L, p<0.001) concentrations than controls (HVA, 206±70nmol/L; 5-HIAA, 98±31nmol/L; and MHPG, 42±7nmol/L). Higher HVA concentrations were associated with a history of psychosis in the bipolar disorder sample. Subjects with ADHD had higher HVA (240±94nmol/L, p<0.001) concentrations compared with controls. In addition, SSRI treatment was associated with lower 5-HIAA concentrations in both patient groups. A power analysis indicated that for within-group comparisons, only large effects would be reliably detectable. Thus, there may be moderate-to-small effects caused by medication that were not detected due to the limited size of the sub-groups in these analyses. In conclusion, the present study suggests disorder-specific alterations of CSF monoamine metabolite concentrations in patients with bipolar disorder and ADHD compared with controls; these differences were independent of acute symptoms and medication effects.
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| 28. |
- Rohm, Maria, et al.
(författare)
-
An AMP-activated protein kinase-stabilizing peptide ameliorates adipose tissue wasting in cancer cachexia in mice
- 2016
-
Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 22:10, s. 1120-1130
-
Tidskriftsartikel (refereegranskat)abstract
- Cachexia represents a fatal energy-wasting syndrome in a large number of patients with cancer that mostly results in a pathological loss of skeletal muscle and adipose tissue. Here we show that tumor cell exposure and tumor growth in mice triggered a futile energy-wasting cycle in cultured white adipocytes and white adipose tissue (WAT), respectively. Although uncoupling protein 1 (Ucp1)-dependent thermogenesis was dispensable for tumor-induced body wasting, WAT from cachectic mice and tumor-cell-supernatant-treated adipocytes were consistently characterized by the simultaneous induction of both lipolytic and lipogenic pathways. Paradoxically, this was accompanied by an inactivated AMP-activated protein kinase (Ampk), which is normally activated in peripheral tissues during states of low cellular energy. Ampk inactivation correlated with its degradation and with upregulation of the Ampk-interacting protein Cidea. Therefore, we developed an Ampk-stabilizing peptide, ACIP, which was able to ameliorate WAT wasting in vitro and in vivo by shielding the Cidea-targeted interaction surface on Ampk. Thus, our data establish the Ucp1-independent remodeling of adipocyte lipid homeostasis as a key event in tumor-induced WAT wasting, and we propose the ACIP-dependent preservation of Ampk integrity in the WAT as a concept in future therapies for cachexia.
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| 29. |
- Rydén, E., et al.
(författare)
-
A history of childhood attention-deficit hyperactivity disorder (ADHD) impacts clinical outcome in adult bipolar patients regardless of current ADHD
- 2009
-
Ingår i: Acta Psychiatrica Scandinavica. - Malden, USA : Wiley-Blackwell. - 0001-690X .- 1600-0447. ; 120:3, s. 239-246
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The occurrence of comorbid attention-deficit hyperactivity disorder (ADHD) might have an impact of the course of the bipolar disorder.Method: Patients with bipolar disorder (n = 159) underwent a comprehensive evaluation with respect to affective symptoms. Independent psychiatrists assessed childhood and current ADHD, and an interview with a parent was undertaken.Results: The prevalence of adult ADHD was 16%. An additional 12% met the criteria for childhood ADHD without meeting criteria for adult ADHD. Both these groups had significantly earlier onset of their first affective episode, more frequent affective episodes (except manic episodes), and more interpersonal violence than the bipolar patients without a history of ADHD.Conclusion: The fact that bipolar patients with a history of childhood ADHD have a different clinical outcome than the pure bipolar group, regardless of whether the ADHD symptoms remained in adulthood or not, suggests that it represent a distinct early-onset phenotype of bipolar disorder.
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| 30. |
- Rydén, Eleonore, et al.
(författare)
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Lower CSF HVA and 5-HIAA in bipolar disorder type 1 with a history of childhood ADHD.
- 2009
-
Ingår i: Journal of neural transmission (Vienna, Austria : 1996). - : Springer Science and Business Media LLC. - 1435-1463 .- 0300-9564.
-
Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder with childhood attention-deficit hyperactivity disorder (ADHD) is a subphenotype characterized by earlier age of onset, more frequent mood episodes, more suicide attempts, and more interpersonal violence than pure bipolar patients. The aim of this study was to test the biological validity of using childhood ADHD to subgroup bipolar disorder. The monoamine metabolites, homovanillinic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were determined in the cerebrospinal fluid (CSF) of 53 euthymic patients with bipolar disorder type 1, with (N = 17) and without (N = 36) a history of childhood ADHD. In addition to structured clinical interviews, childhood ADHD was assessed by a next of kin using the Autism-Tics, ADHD and other comorbidities questionnaire (A-TAC), and by patients themselves using the Wender Utah rating scale (WURS-25). Current ADHD symptoms were assessed by the Brown attention-deficit disorder scale (Brown ADD). Bipolar patients with childhood ADHD had significantly lower CSF concentration (mean +/- SD nmol/l) of HVA (89.0 +/- 32.5 vs. 115.8 +/- 47.1, P = 0.039) and 5-HIAA (88.7 +/- 38.5 vs. 116 +/- 47.9, P = 0.021) than pure bipolar patients. CSF MHPG did not differ between the groups. The WURS-25 score correlated negatively with both HVA (r = -0.27, P = 0.048) and 5-HIAA (r = -0.30, P = 0.027). Likewise, the Brown ADD total score correlated negatively with both HVA (r = -0.34, P = 0.013) and 5-HIAA (r = -0.35, P = 0.011). These findings indicate different monoaminergic function in patients with and without childhood ADHD in bipolar disorder type 1. This lends biological support to the notion that those with childhood ADHD represent a valid subphenotype of bipolar disorder.
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| 31. |
- Rydén, Henric, et al.
(författare)
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Chemical shift encoding using asymmetric readout waveforms.
- 2021
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Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 0740-3194 .- 1522-2594. ; 85:3, s. 1468-1480
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe a new method for encoding chemical shift using asymmetric readout waveforms that enables more SNR-efficient fat/water imaging.METHODS: Chemical shift was encoded using asymmetric readout waveforms, rather than conventional shifted trapezoid readouts. Two asymmetric waveforms are described: a triangle and a spline. The concept was applied to a fat/water separated RARE sequence to increase sampling efficiency. The benefits were investigated through comparisons to shifted trapezoid readouts. Using asymmetric readout waveforms, the scan time was either shortened or maintained to increase SNR. A matched in-phase waveform is also described that aims to improve the SNR transfer function of the fat and water estimates. The sequence was demonstrated for cervical spine, musculoskeletal (MSK), and optic nerve applications at 3T and compared with conventional shifted readouts.RESULTS: blurring. Maintaining the scan times and using asymmetric readout waveforms achieved an SNR improvement in agreement with the prolonged sampling duration.CONCLUSIONS: Asymmetric readout waveforms offer an additional degree of freedom in pulse sequence designs where chemical shift encoding is desired. This can be used to significantly shorten scan times or to increase SNR with maintained scan time.
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| 32. |
- Rydén, Mikael, et al.
(författare)
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Adipose zinc-α2-glycoprotein is a catabolic marker in cancer and noncancerous states
- 2012
-
Ingår i: Journal of Internal Medicine. - : Wiley-Blackwell. - 0954-6820 .- 1365-2796. ; 271:4, s. 414-420
-
Tidskriftsartikel (refereegranskat)abstract
- Objective Zinc-α2-glycoprotein (ZAG) has been proposed as a tumour-derived cancer cachexia factor. However, ZAG is produced by some normal tissues, including white adipose tissue (WAT), and high serum ZAG levels are present in nonmalignant conditions. We determined whether human WAT contributes to serum ZAG levels and how serum and WAT-secreted ZAG levels correlate with catabolism in patients with cancer and in obese subjects undergoing a very low-calorie diet (VLCD) for 11 days.Design/subjects ZAG levels in serum and in conditioned medium from WAT/adipocytes were determined by enzyme-linked immunosorbent assay. ZAG release from WAT in vivo was determined in 10 healthy subjects. The correlation between ZAG and cachexia was studied in 34 patients with newly diagnosed gastrointestinal cancer. The impact of a VLCD on ZAG release and serum levels was assessed in 10 obese women.Results ZAG was released from abdominal WAT and adipocytes in vitro. However, the arteriovenous differences in vivo showed that there was no significant contribution of WAT to the circulating levels. WAT-secreted but not serum ZAG correlated positively with poor nutritional status but not with fat mass (or body mass index) in patients with gastrointestinal cancer. In obese subjects on a VLCD, ZAG secretion from WAT increased significantly whereas serum levels remained unaltered.Conclusions ZAG is released from human WAT, but this tissue does not contribute significantly to the circulating levels. WAT-secreted ZAG correlates with nutritional status but not with fat mass in both cancer and nonmalignant conditions. Adipose ZAG is therefore a local factor activated primarily by the catabolic state per se.
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| 33. |
- Rydén, Mikael, et al.
(författare)
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Lipolysis defect in people with obesity who undergo metabolic surgery
- 2022
-
Ingår i: Journal of Internal Medicine. - : Wiley-Blackwell Publishing Inc.. - 0954-6820 .- 1365-2796. ; 292:4, s. 667-678
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Cross-sectional studies demonstrate that catecholamine stimulation of fat cell lipolysis is blunted in obesity. We investigated whether this defect persists after substantial weight loss has been induced by metabolic surgery, and whether it is related to the outcome.DESIGN/METHODS: Patients with obesity not able to successfully reduce body weight by conventional means (n = 126) were investigated before and 5 years after Roux-en-Y gastric bypass surgery (RYGB). They were compared with propensity-score matched subjects selected from a control group (n = 1017), and with the entire group after adjustment for age, sex, body mass index (BMI), fat cell volume and other clinical parameters. Catecholamine-stimulated lipolysis (glycerol release) was investigated in isolated fat cells using noradrenaline (natural hormone) or isoprenaline (synthetic beta-adrenoceptor agonist).RESULTS: Following RYGB, BMI was reduced from 39.9 (37.5-43.5) (median and interquartile range) to 29.5 (26.7-31.9) kg/m2 (p < 0.0001). The post-RYGB patients had about 50% lower lipolysis rates compared with the matched and total series of controls (p < 0.0005). Nordrenaline activation of lipolysis at baseline was associated with the RYGB effect; those with high lipolysis activation (upper tertile) lost 30%-45% more in body weight, BMI or fat mass than those with low (bottom tertile) initial lipolysis activation (p < 0.0007).CONCLUSION: Patients with obesity requiring metabolic surgery have impaired ability of catecholamines to stimulate lipolysis, which remains despite long-term normalization of body weight by RYGB. Furthermore, preoperative variations in the ability of catecholamines to activate lipolysis may predict the long-term reduction in body weight and fat mass.
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| 34. |
- Ryden, Mikael
(författare)
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Neurotrophic factors and their receptors structure-function relationships and signalling mechanisms
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The development, survival and maintenance of the vertebrate nervous system requires the continuous supply of a set of polypeptides termed neurotrophic factors. Among these, the neurotrophins (NTs) and members of the transforming growth factor-B (TGF-B) superfamily have raised substantial hopes for future clinical applications. Mammalian NTs comprise four members to date, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4). NTs interact with two distinct classes of cell-surface receptors: members of the receptor tyrosine kinase family Trk, and p75NTR a smaller receptor that lacks intrinsic catalytic activity. While p75NTR binds all neurotrophins with equal affinity, activation of Trks is specific in that NGF activates TrkA, BDNF and NT-4 interact with TrkB and NT-3 activates TrkC. In addition, NT-3 can signal, albeit to a lesser extent, through TrkA and TrkB. While the function of Trks as signalling receptors is well established, the role of p75NTR is less clear. In contrast to the restricted number of neurotrophins, members of the TGF-B superfamily comprise a heterogenous collection of pleiotropic proteins grouped into several subfamilies. These include the prototypic TGF-Bs, activins and bone morphogenetic proteins (BMP). Most members have been shown to signal through a unique heteromeric complex comprised of two classes of serine threonine kinase receptors termed type I and II. Type II receptors are constitutively active kinases with the ability to bind ligand on their own, while type I receptors require type II receptors in order to interact with ligand efficiently. Aims: In the first part of the present thesis we focused our attention on the enigmatic p75NTR. We set out to determine residues in neurotrophins responsible for interaction with p75NTR and to define functional roles for p75NTR in vertebrate neurons. In the second part, we studied receptors expressed in different neuronal tissues. We sought to investigate the expression levels of neurotrophin receptors in neuronal tumours and embarked on a project aimed at isolating and characterizing novel receptors for the TGF-B superfamily expressed in the nervous system. Results: By site-directed mutagenesis we generated recombinant neurotrophin molecules where specific residues were replaced by alanine. Using a range of in vitro assays we compared the activity of mutant molecules with native protein. This allowed us to assess the importance of each individual residue in receptor binding and activation. In the first study we mapped a major functional epitope in BDNF, NT-3 and NT-4 involved in binding to p75NTR, This is located in two spatially close loop regions in one end of the molecules and is formed by only 2-3 positively charged residues. Albeit similar, this epitope is clearly different in its precise conformation between the different neurotrophins. Furthermore it appears to be dispensable for binding and activation of Trks. Interestingly, on cells co-expressing p75NTR and cognate Trks, NT-4, but not BDNF or NT-3 seems to require p75NTR binding in order to activate TrkB efficiently, indicating that p75NTR may modulate neuronal responsiveness to NT-4. In the second study we were able to determine that the major determinant in NT-3 responsible for its interaction with the non-cognate receptors TrkA and TrkB proved to be the same epitope used for p75NTR binding, demonstrating that the interaction between NT-3 and non-cognate Trks is very localized. In the third report we assessed the functional role of p75NTR in NGF responsive vertebrate neurons with the use of a mutant NGF selectively deficient in p75NTR binding. We conclude that binding to p75NTR modulates TrkA function, by enhancing TrkA mediated neuronal survival in response to NGF when the factor is present in limiting amounts or when cell-surface receptor expression is altered. In the last mutagenesis study we assessed the role of a conserved loop region situated in one end of the NGF-molecule. Positively charged residues were shown to be important for p75NTR binding, in line with the previously shown involvement of basic residues in binding to p75NTR, In the last two reports we focused our attention on receptors for neurotrophic factors. Neurotrophins and their receptors are believed to play a role in childhood neuroblastoma tumours (NB). We analyzed the expression pattern of mRNA coding for TrkC and found that high levels of expression correlated with favourable tumour stage and clinical outcome. This indicates that determination of TrkC mRNA may be of clinical significance in the evaluation of patients with NB. In our final work, we isolated a novel type I receptor (ALK-7) for the TGF-B superfamily expressed in the nervous system. ALK-7 is predominantly expressed in adult neurons of the central nervous system and can interact with type ll receptors for activin and TGF-B in a ligand dependent manner, although we were unable to demonstrate physical interactions between ALK-7 and the ligands. These results suggest that ALK 7 may be the receptor for a novel member of the TGF-B superfamily with neurotrophic activities.
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| 35. |
- Ryden, Mikael, et al.
(författare)
-
Transplanted Bone Marrow-Derived Cells Contribute to Human Adipogenesis
- 2015
-
Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 22:3, s. 408-417
-
Tidskriftsartikel (refereegranskat)abstract
- Because human white adipocytes display a high turnover throughout adulthood, a continuous supply of precursor cells is required to maintain adipogenesis. Bone marrow (BM)-derived progenitor cells may contribute to mammalian adipogenesis; however, results in animal models are conflicting. Here we demonstrate in 65 subjects who underwent allogeneic BM or peripheral blood stem cell (PBSC) transplantation that, over the entire lifespan, BM/PBSC-derived progenitor cells contribute similar to 10% to the subcutaneous adipocyte population. While this is independent of gender, age, and different transplantation-related parameters, body fat mass exerts a strong influence, with up to 2.5-fold increased donor cell contribution in obese individuals. Exome and whole-genome sequencing of single adipocytes suggests that BM/PBSC-derived progenitors contribute to adipose tissue via both differentiation and cell fusion. Thus, at least in the setting of transplantation, BM serves as a reservoir for adipocyte progenitors, particularly in obese subjects.
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| 36. |
- Salarvan, Sara, et al.
(författare)
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Neuropsychological profiles of adult bipolar disorder patients with and without comorbid attention-deficit hyperactivity disorder.
- 2019
-
Ingår i: International journal of bipolar disorders. - : Springer Science and Business Media LLC. - 2194-7511. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Comorbid attention-deficit/hyperactivity disorder (ADHD) is common in bipolar disorder and associated with worse outcomes. Cognitive testing might be a tool to identify this group. Here we compare the neuropsychological profiles of bipolar disorder patients with (BD+cADHD) and without (BD-cADHD) childhood attention-deficit hyperactivity disorder.Adult patients with BD-cADHD (n=66), BD+cADHD (n=32), and healthy controls (n=112) were tested using a comprehensive battery of neuropsychological tests. Patients underwent rigorous diagnostic assessments for bipolar disorder and ADHD, as well as a parental interview to establish childhood ADHD.The neuropsychological profiles of the groups were similar, except that the BD+cADHD group performed significantly worse on working memory. Working memory did not differ between those in the BD+cADHD group who only had a history of childhood ADHD and those that still met criteria for ADHD in adulthood.Cognitive testing had limited power to differentiate between bipolar disorder adults with and without childhood ADHD. The BD+cADHD subgroup cannot explain the significant cognitive heterogeneity seen in bipolar disorder patients.
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| 37. |
- Sandberg, Maria E. C., et al.
(författare)
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Influence of radiotherapy for the first tumor on aggressiveness of contralateral breast cancer
- 2013
-
Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 132:10, s. 2388-2394
-
Tidskriftsartikel (refereegranskat)abstract
- We aimed to investigate if characteristics of contralateral breast cancer (CBC) are influenced by adjuvant radiotherapy for the first breast cancer. Using information from population-based registers and medical records, we analyzed two cohorts comprising all women with CBC diagnosed >3 months after their first cancer (809 patients in Stockholm 19762005 and 750 patients in South Sweden 19772005). We used Poisson regression to calculate risk of distant metastasis after CBC, comparing patients treated and not treated with radiotherapy for the first cancer. Logistic regression was used to estimate odds ratio (OR) of more aggressive tumor characteristics in the second cancer, compared to the first. For patients with CBC in Stockholm with <5 years between the cancers radiotherapy for the first cancer conferred a nearly doubled risk of distant metastasis [incidence rate ratio (IRR) = 1.91; 95% confidence interval (CI): 1.272.88], compared to those not treated with radiotherapy. This was replicated in the South Swedish cohort [IRR = 2.12 (95% CI: 1.403.23)]. In Stockholm, we found an increased odds that, following radiotherapy, a second cancer was of more advanced TNM-stage [OR 2.16 (95% CI 1.134.11)] and higher histological grade [OR = 2.00 (95% CI 1.083.72)] compared to the first, for patients with CBC with <5 years between the cancers. No effect on any of the investigated outcomes was seen for patients diagnosed with CBC >5 years from the first cancer. In conclusion, patients diagnosed with CBC within 5 years had worse prognosis and more aggressive tumor characteristics of the second cancer, if they had received radiotherapy for their first cancer, compared to no radiotherapy.
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| 38. |
- Sarsenbayeva, Assel
(författare)
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Adverse drug effects on glucose and lipid metabolism: is human adipose tissue of importance?
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many pharmacological agents that are widely prescribed in clinical practice have adverse metabolic effects, such as hyperglycaemia, insulin resistance, and diabetes. Among such drugs are antipsychotics, prescribed for treatment of schizophrenia; statins, which inhibit cholesterol synthesis and prevent cardiovascular events; finally, potent anti-inflammatory agents, glucocorticoids. This thesis is focused on investigating the direct effects of second-generation antipsychotics (SGAs), statins, and glucocorticoids on human adipose tissue metabolism and inflammation, particularly in the light of macrophage-adipocyte cross talk.In Paper I, the direct effects of SGAs on adipose tissue glucose and lipid metabolism were studied. SGAs had a mild effect on adipocyte glucose uptake and lipolysis at therapeutic concentrations. At supra-therapeutic concentrations, the drugs demonstrated anti-inflammatory potential, reducing the expression of pro-inflammatory genes in the adipose tissue.In Paper II, the anti-inflammatory potential of SGAs and dexamethasone was further explored. The effects of the drugs on macrophage phenotype and communication with adipocytes were addressed. SGAs at supra-therapeutic concentrations exerted mild anti-inflammatory effects on macrophages, while dexamethasone acted as a potent anti-inflammatory agent and promoted alternatively activated M2 macrophage phenotype. Macrophages, in turn, induced marked upregulation of pro-inflammatory genes in adipocytes, which was partially reversed by dexamethasone, while SGAs had no effects on macrophage-adipocyte communication.In Paper III, we examined the association of statin therapy on systemic insulin resistance and direct effects statins on human adipose tissue and pancreatic islets functions. We also studied association of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the enzyme involved in cholesterol synthesis, and genetic inhibition of HMGCR seen with certain polymorphisms with adipose tissue and plasma metabolome. Our study demonstrated minor direct effects of statins on human adipose tissue metabolism and insulin secretion in pancreatic islets. We observed that HMGCR expression was associated with a number of metabolic and mitochondrial pathways in the adipose tissue, while LDL-lowering HMGCR polymorphism was negatively associated with plasma phosphatidylcholines and sphingomyelins. In Paper IV we studied the effects of glucocorticoids on adipose tissue fibrosis, particularly in terms of macrophage-preadipocyte communication. Together with inflammation, adipose tissue fibrosis impairs adipocyte metabolism and functions. We observed that glucocorticoids at high concentrations have pro-fibrotic effects in adipose tissue. Macrophage-preadipocyte co-culture data showed that macrophages stimulate phenotypic switch of preadipocytes to pro-fibrotic myofibroblasts, and this effect was exacerbated by dexamethasone. Our findings suggest that pro-fibrotic effects of excess glucocorticoids on adipose tissue are at least partially mediated via their effects on macrophage-preadipocyte communication.We conclude that SGAs and statins have a mild direct effect on adipose tissue metabolism and their diabetogenic effects could to be induced via other organs, such as brain, liver or muscle. By contrast, glucocorticoids, directly impair adipose tissue metabolism and exacerbates adipose tissue fibrosis, which could be one of the contributing factors to their metabolic adverse effects.
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| 39. |
- Skorpil, Mikael, et al.
(författare)
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The effect of radiotherapy on fat content and fatty acids in myxoid liposarcomas quantified by MRI
- 2017
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Ingår i: Magnetic Resonance Imaging. - : Elsevier. - 0730-725X .- 1873-5894. ; 43, s. 37-41
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Tidskriftsartikel (refereegranskat)abstract
- Background: Myxoid liposarcomas are highly radiosensitive. Consequently radiotherapy is often used pre-operatively to reduce tumor volume and lessen the post-operative deficit. In soft-tissue sarcomas therapy response is mainly evaluated using magnetic resonance imaging (MRI) and the fundamental criterion for a positive response is decreased tumor size. In myxoid liposarcomas an increased fat content is also known to occur as a response to radiotherapy. Objective: To highlight the difficulties of MRI for therapy response evaluation in irradiated myxoid liposarcomas, by using MRI Dixon techniques enabling objective quantification of proton density fat fraction (%) and the number of double bonds (ndb; unsaturation degree) of fatty acids. Secondly, to compare quantitative fat fraction measurements versus visual grading of fat content on T1-weighted images. Case descriptions: Prior to surgery, two patients with myxoid liposarcoma were treated with 50 Gy. Following radiotherapy, both tumors on MRI showed reduced size, elevated fat fraction and transformed fat fraction histograms with diverse changes of ndb, while histopathological specimens showed discordant treatment effects; one case having good response and the other having poor response. Conclusions: A decrease in tumor size and increase in fat content on MRI cannot be interpreted as positive therapy response in radiotherapy of myxoid liposarcomas. Our data also give further supporting evidence that differentiation and maturation of tumor cells is the cause for the lipoma-like areas seen after radiotherapy. Finally, quantitative MRI Dixon techniques are preferable to visual grading for estimating the fat content in lipomatous tumors.
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| 40. |
- van Harmelen, Vanessa, et al.
(författare)
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The vascular peptide endothelin-1 links fat accumulation with alterations of visceral adipocyte lipolysis
- 2008
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 57:2, s. 378-386
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTAT-Visceral obesity increases risk of insulin resistance and type 2 diabetes. This may partly be due to a region-specific resistance to insulin's antilipolytic effect in visceral adipocytes. We investigated whether adipose tissue releases the vascular peptide endothelin-1 (ET-1) and whether ET-1 could account for regional differences in lipolysis. RESEARCH DESIGN AND METHODS-One group consisted of eleven obese and eleven nonobese subjects in whom ET-1 levels were compared between abdominal subcutaneous and arterialized blood samples. A second group included subjects undergoing anti-obesity surgery. Abdominal subcutaneous and visceral adipose tissues were obtained to study the effect of ET-1 on differentiated adipocytes regarding lipolysis and gene and protein expression. RESULTS-Adipose tissue had a marked net release of ET-1 in vivo, which was 2.5-fold increased in obesity. In adipocytes treated with ET-1, the antilipolytic effect of insulin was attenuated in Visceral but not in subcutaneous adipocytes, which could not be explained by effects of ET-1 on adipocyte differentiation. ET-1 decreased the expression of insulin receptor, insulin receptor substrate-1 and phosphodiesterase-3B and increased the expression of endothelin receptor-B (ETBR) in visceral but not in subcutaneous adipocytes. These effects were mediated via ETBR with signals through protein kinase C and calmodulin pathways. The effect of ET-1 could be mimicked by knockdown of IRS-1. CONCLUSIONS-ET-1 is released front human adipose tissue and links fat accumulation to insulin resistance. It selectively counteracts insulin inhibition of visceral adipocyte lipolysis via ETBR signaling pathways, which affect multiple steps in insulin signaling.
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| 41. |
- Viktorin, Alexander, et al.
(författare)
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The Risk of Treatment-Emergent Mania With Methylphenidate in Bipolar Disorder
- 2017
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Ingår i: American Journal of Psychiatry. - Arlington, USA : American Psychiatric Association Publishing. - 0002-953X .- 1535-7228. ; 174:4, s. 341-348
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The authors sought to determine the risk of treatment-emergent mania associated with methylphenidate, used in monotherapy or with a concomitant mood-stabilizing medication, in patients with bipolar disorder.Method: Using linked Swedish national registries, the authors identified 2,307 adults with bipolar disorder who initiated therapy with methylphenidate between 2006 and 2014. The cohort was divided into two groups: those with and those without concomitant mood-stabilizing treatment. To adjust for individual-specific confounders, including disorder severity, genetic makeup, and early environmental factors, Cox regression analyses were used, conditioning on individual to compare the rate of mania (defined as hospitalization for mania or a new dispensation of stabilizing medication) 0-3 months and 3-6 months after medication start following nontreated periods.Results: Patients on methylphenidate monotherapy displayed an increased rate of manic episodes within 3 months of medication initiation (hazard ratio=6.7, 95% CI=2.0-22.4), with similar results for the subsequent 3 months. By contrast, for patients taking mood stabilizers, the risk of mania was lower after starting methylphenidate (hazard ratio=0.6, 95% CI=0.4-0.9). Comparable results were observed when only hospitalizations for mania were counted.Conclusions: No evidence was found for a positive association between methylphenidate and treatment-emergent mania among patients with bipolar disorder who were concomitantly receiving a mood-stabilizing medication. This is clinically important given that up to 20% of people with bipolar disorder suffer from comorbid ADHD. Given the markedly increased hazard ratio of mania following methylphenidate initiation in bipolar patients not taking mood stabilizers, careful assessment to rule out bipolar disorder is indicated before initiating monotherapy with psychostimulants.
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| 42. |
- von Zur-Mühlen, Bengt, Docent, 1966-, et al.
(författare)
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Open Randomized Multicenter Study to Evaluate Safety and Efficacy of Low Molecular Weight Sulfated Dextran in Islet Transplantation
- 2019
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Ingår i: Transplantation. - : LIPPINCOTT WILLIAMS & WILKINS. - 0041-1337 .- 1534-6080. ; 103:3, s. 630-637
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Tidskriftsartikel (refereegranskat)abstract
- Background. When transplanted human pancreatic islets are exposed to blood during intraportal infusion, an innate immune response is triggered. This instant blood-mediated inflammatory reaction (IBMIR) activates the coagulation and complement cascades and leads to the destruction of 25% of all transplanted islets within minutes, contributing to the need, in most patients, for islets from more than 1 donor. Low molecular dextran sulfate (LMW-DS) has been shown in experimental settings to inhibit IBMIR. Methods. The Clinical Islet Transplantation consortium 01 study was a phase II, multicenter, open label, active control, randomized study. Twenty-four subjects were randomized to peritransplant intraportal and systemic treatment with either LMW-DS or heparin, targeting an activated partial thromboplastin time of 150 +/- 10 seconds and 50 +/- 5 seconds, respectively. C-peptide response was measured with a mixed meal tolerance test at 75 and 365 days after transplant. Results. Low molecular dextran sulfate was safe and well tolerated with similar observed adverse events (mostly attributed to immunosuppression) as in the heparin arm. There was no difference in the primary endpoint (stimulated C-peptide 75 +/- 5 days after the first transplant) between the 2 arms (1.33 +/- 1.10 versus 1.56 +/- 1.36 ng/mL, P = 0.66). Insulin requirement, metabolic parameters, Clarke and HYPO score, quality of life, and safety were similar between the 2 treatments groups. Conclusions. Even with low dosing, LMW-DS showed similar efficacy in preventing IBMIR to promote islet engraftment when compared to "state-of-the art" treatment with heparin. Furthermore, no substantial differences in the efficacy and safety endpoints were detected, providing important information for future studies with more optimal dosing of LMW-DS for the prevention of IBMIR in islet transplantation.
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