| 1. |
- Alvarsson, Jonathan, et al.
(författare)
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Ligand-Based Target Prediction with Signature Fingerprints
- 2014
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Ingår i: Journal of Chemical Information and Modeling. - : American Chemical Society (ACS). - 1549-9596 .- 1549-960X. ; 54:10, s. 2647-2653
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Tidskriftsartikel (refereegranskat)abstract
- When evaluating a potential drug candidate it is desirable to predict target interactions in silico prior to synthesis in order to assess, e.g., secondary pharmacology. This can be done by looking at known target binding profiles of similar compounds using chemical similarity searching. The purpose of this study was to construct and evaluate the performance of chemical fingerprints based on the molecular signature descriptor for performing target binding predictions. For the comparison we used the area under the receiver operating characteristics curve (AUC) complemented with net reclassification improvement (NRI). We created two open source signature fingerprints, a bit and a count version, and evaluated their performance compared to a set of established fingerprints with regards to predictions of binding targets using Tanimoto-based similarity searching on publicly available data sets extracted from ChEMBL. The results showed that the count version of the signature fingerprint performed on par with well-established fingerprints such as ECFP. The count version outperformed the bit version slightly; however, the count version is more complex and takes more computing time and memory to run so its usage should probably be evaluated on a case-by-case basis. The NRI based tests complemented the AUC based ones and showed signs of higher power.
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| 2. |
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| 3. |
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| 4. |
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| 5. |
- Hjort, Rebecka, et al.
(författare)
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Family history of type 1 and type 2 diabetes and risk of latent autoimmune diabetes in adults (LADA)
- 2017
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Ingår i: Diabetes & Metabolism. - : Elsevier BV. - 1262-3636 .- 1878-1780. ; 43:6, s. 536-542
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Tidskriftsartikel (refereegranskat)abstract
- Background: A family history of diabetes (FHD) is a strong predictor of diabetes risk, yet has rarely been investigated in latent autoimmune diabetes in adults (LADA). This study therefore investigated the risk of LADA and type 2 diabetes (T2D) in relation to FHD, taking into account the type of diabetes in relatives. Methods: Data from a population-based study were used, including incident cases of LADA [glutamic acid decarboxylase antibody (GADA)-positive, n = 378] and T2D (GADA-negative, n = 1199), and their matched controls (n = 1484). First-degree relatives with disease onset at age. <. 40 years and taking insulin treatment were classified as type 1 diabetes (T1D) or, if otherwise, as T2D. Odds ratios (ORs) were adjusted for age, gender, BMI, education and smoking. Cases were genotyped for high- and low-risk HLA genotypes. Results: Both FHD-T1D (OR: 5.8; 95% CI: 3.2-10.3) and FHD-T2D (OR: 1.9; 95% CI: 1.5-2.5) were associated with an increased risk of LADA, whereas the risk of T2D was associated with FHD-T2D (OR: 2.7; 95% CI: 2.2-3.3), but not FHD-T1D. In LADA patients, FHD-T1D vs FHD-T2D was associated with higher GADA but lower C-peptide levels, lower prevalence of low-risk HLA genotypes (5.0% vs 28.6%, respectively; P = 0.038) and a tendency for higher prevalence of high-risk genotypes (90.0% vs 69.1%, respectively; P = 0.0576). Conclusion: The risk of LADA is substantially increased with FHD-T1D but also, albeit significantly less so, with FHD-T2D. This supports the idea of LADA as a mix of both T1D and T2D, but suggests that the genes related to T1D have greater impact. LADA patients with FHD-T1D had more T1D-like features, emphasizing the heterogeneity of LADA.
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| 6. |
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| 7. |
- Hjort, Rebecka, et al.
(författare)
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Low birthweight is associated with an increased risk of LADA and type 2 diabetes: results from a Swedish case-control study
- 2015
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 58:11, s. 2525-2532
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis Our aim was to investigate the association between birthweight and latent autoimmune diabetes in adults (LADA), a common diabetes form with features of both type 1 and type 2 diabetes. Methods We used data from the Epidemiological Study of Risk Factors for LADA and Type 2 Diabetes (ESTRID), a Swedish population-based study. Eligible for the analysis were 134 incident LADA cases (glutamic acid decarboxylase antibody [GADA] positive), 350 incident type 2 diabetes cases (GADA negative) and 603 randomly selected controls. We present ORs and 95% CIs for LADA and type 2 diabetes in relation to birthweight, adjusted for sex, age, BMI and family history of diabetes. Results Low birthweight increased the risk of LADA as well as the risk of type 2 diabetes; OR per kg reduction was estimated as 1.52 (95% CI 1.12, 2.08) and 1.58 (1.23, 2.04), respectively. The OR for participants weighing < 3 kg compared with >= 4 kg at birth was estimated as 2.38 (1.23, 4.60) for LADA and 2.37 (1.37, 4.10) for type 2 diabetes. A combination of low birthweight (< 3 kg) and current overweight (BMI >= 25) further augmented the risk: LADA, OR 3.26 (1.69, 6.29); and type 2 diabetes, OR 39.93 (19.27, 82.71). Family history of diabetes had little impact on these estimates. Conclusions/interpretation Our results suggest that low birthweight may be a risk factor for LADA of the same strength as for type 2 diabetes. These findings support LADA, despite its autoimmune component, having an aetiology that includes factors related to type 2 diabetes.
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| 8. |
- Hjort, Rebecka, et al.
(författare)
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Overweight, obesity and the risk of LADA : results from a Swedish case–control study and the Norwegian HUNT Study
- 2018
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 61:6, s. 1333-1343
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: Excessive weight is a risk factor for type 2 diabetes, but its role in the promotion of autoimmune diabetes is not clear. We investigated the risk of latent autoimmune diabetes in adults (LADA) in relation to overweight/obesity in two large population-based studies. Methods: Analyses were based on incident cases of LADA (n = 425) and type 2 diabetes (n = 1420), and 1704 randomly selected control participants from a Swedish case–control study and prospective data from the Norwegian HUNT Study including 147 people with LADA and 1,012,957 person-years of follow-up (1984–2008). We present adjusted ORs and HRs with 95% CI. Results: In the Swedish data, obesity was associated with an increased risk of LADA (OR 2.93, 95% CI 2.17, 3.97), which was even stronger for type 2 diabetes (OR 18.88, 95% CI 14.29, 24.94). The association was stronger in LADA with low GAD antibody (GADA;
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| 9. |
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| 10. |
- Hjort, Rebecka, et al.
(författare)
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Physical Activity, Genetic Susceptibility, and the Risk of Latent Autoimmune Diabetes in Adults and Type 2 Diabetes
- 2020
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 105:11
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Physical activity (PA) has been linked to a reduced risk of type 2 diabetes by reducing weight and improving insulin sensitivity. We investigated whether PA is associated with a lower incidence of latent autoimmune diabetes in adults (LADA) and whether the association is modified by genotypes of human leukocyte antigen (HLA), transcription factor 7-like 2 (TCF7L2)-rs7903146, or the fat mass and obesity-associated gene, FTO-rs9939609. METHODS: We combined data from a Swedish case-control study and a Norwegian prospective study including 621 incident cases of LADA and 3596 cases of type 2 diabetes. We estimated adjusted pooled relative risks (RRs) and 95% CI of diabetes in relation to high (≥ 30 minutes of moderate activity 3 times/week) self-reported leisure time PA, compared to sedentariness. RESULTS: High PA was associated with a reduced risk of LADA (RR 0.61; CI, 0.43-0.86), which was attenuated after adjustment for body mass index (BMI) (RR 0.90; CI, 0.63-1.29). The reduced risk applied only to noncarriers of HLA-DQB1 and -DRB1 (RR 0.49; CI, 0.33-0.72), TCF7L2 (RR 0.62; CI, 0.45-0.87), and FTO (RR 0.51; CI, 0.32-0.79) risk genotypes. Adjustment for BMI attenuated but did not eliminate these associations. For type 2 diabetes, there was an inverse association with PA (RR 0.49; CI, 0.42-0.56), irrespective of genotype. MAIN CONCLUSIONS: Our findings indicate that high PA is associated with a reduced risk of LADA in individuals without genetic susceptibility.
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| 11. |
- Lau, Joey, 1979-
(författare)
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Implantation-Site Dependent Differences in Engraftment and Function of Transplanted Pancreatic Islets
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Transplanting pancreatic islets into the liver through the portal vein is currently the most common procedure in clinical islet transplantations for treating patients with brittle type 1 diabetes. However, most islet grafts fail within a 5-year period necessitating retransplantation. The vascular connections are disrupted at islet isolation and implanted islets depend on diffusion of oxygen and nutrients in the immediate posttransplantation period. Rapid and efficient revascularization is of utmost importance for the survival and long-term function of transplanted islets. In this thesis, the influence of the implantation microenvironment for islet engraftment and function was studied. Islets were transplanted into the liver, the renal subcapsular site or the pancreas. Islets implanted into the liver contained fewer glucagon-positive cells than islets implanted to the kidney and endogenous islets. Intraportally transplanted islets responded with insulin and glucagon release to secretagogues, but only when stimulated through the hepatic artery. Thus, the intrahepatic grafts were selectively revascularized from the hepatic artery. The vascular density in human islets transplanted into the liver of athymic mice was markedly lower when compared to human islets grafted to the kidney. Islets implanted into their physiological environment, the pancreas, were markedly better revascularized. Insulin content, glucose-stimulated insulin release, (pro)insulin biosynthesis and glucose oxidation rate were markedly decreased in transplanted islets retrieved from the liver, both when compared to endogenous and transplanted islets retrieved from the pancreas. Only minor changes in metabolic functions were observed in islets implanted into the pancreas when compared to endogenous islets. The present findings demonstrate that the microenvironment has a major impact on the engraftment of transplanted islets. Elucidating the beneficial factors that promote engraftment would improve the survival and long-term function of transplanted islets. Ultimately, islet transplantation may be provided to an increased number of patients with type 1 diabetes.
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| 12. |
- Lau, Joey, et al.
(författare)
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Implantation site-dependent dysfunction of transplanted pancreatic islets
- 2007
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 56:6, s. 1544-1550
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE—Clinical islet transplantations are performed through infusion of islets via the portal vein into the liver. This study aimed at characterizing the influence of the implantation microenvironment on islet graft metabolism and function. RESEARCH DESIGN AND METHODS—Islets were transplanted into their normal environment, i.e., the pancreas, or intraportally into the liver of mice. One month posttransplantation, the transplanted islets were retrieved and investigated for changes in function and gene expression. RESULTS—Insulin content, glucose-stimulated insulin release, (pro)insulin biosynthesis, and glucose oxidation rate were markedly decreased in islets retrieved from the liver, both when compared with islets transplanted into the pancreas and endogenous islets. Islets transplanted into the pancreas showed normal insulin content, (pro)insulin biosynthesis, and glucose oxidation rate but increased basal insulin secretion and impaired glucose stimulation index. Gene expression data for retrieved islets showed downregulation of pancreatic and duodenal homeobox gene-1, GLUT-2, glucokinase, mitochondrial glycerol-phosphate dehydrogenase, and pyruvate carboxylase, preferentially in intraportally transplanted islets. CONCLUSIONS—Islets transplanted into their normal microenvironment, i.e., the pancreas, display gene expression changes when compared with endogenous islets but only moderate changes in metabolic functions. In contrast, site-specific properties of the liver markedly impaired the metabolic functions of intraportally transplanted islets.
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| 13. |
- Lofvenborg, J. E., et al.
(författare)
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Coffee consumption and the risk of latent autoimmune diabetes in adults-results from a Swedish case-control study
- 2014
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Ingår i: Diabetic Medicine. - : Wiley. - 1464-5491 .- 0742-3071. ; 31:7, s. 799-805
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Tidskriftsartikel (refereegranskat)abstract
- Aims Coffee consumption is associated with a reduced risk of Type2 diabetes. Our aim was to investigate if coffee intake may also reduce the risk of latent autoimmune diabetes in adults, an autoimmune form of diabetes with features of Type2 diabetes. Methods We used data from a population-based case-control study with incident cases of adult onset (35years) diabetes, including 245 cases of latent autoimmune diabetes in adults (glutamic acid decarboxylase antibody positive), 759 cases of Type2 diabetes (glutamic acid decarboxylase antibody negative), together with 990 control subjects without diabetes, randomly selected from the population. Using questionnaire information on coffee consumption, we estimated the odds ratio of latent autoimmune diabetes in adults and Type2 diabetes adjusted for age, sex, BMI, smoking, physical activity, alcohol, education and family history of diabetes. Results Coffee intake was inversely associated with Type2 diabetes (odds ratio0.92, 95%CI 0.87-0.98 per cup/day). With regard to latent autoimmune diabetes in adults, the general trend was weak (odds ratio1.04, 95%CI 0.96-1.13), but stratification by degree of autoimmunity (median glutamic acid decarboxylase antibody levels) suggested that coffee intake may be associated with an increased risk of high glutamic acid decarboxylase antibody latent autoimmune diabetes in adults (odds ratio1.11, 95%CI 1.00-1.23 per cup/day). Furthermore, for every additional cup of coffee consumed per day, there was a 15.2% (P=0.0268) increase in glutamic acid decarboxylase antibody levels. Conclusions Our findings confirm that coffee consumption is associated with a reduced risk of Type2 diabetes. Interestingly, the findings suggest that coffee may be associated with development of autoimmunity and possibly an increased risk of more Type1-like latent autoimmune diabetes in adults.
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| 14. |
- Lyckesvärd, Madeleine Nordén, et al.
(författare)
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Linking loss of sodium-iodide symporter expression to DNA damage
- 2016
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 344:1, s. 120-131
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Tidskriftsartikel (refereegranskat)abstract
- Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (< 1 nM) calicheamicin blocked NIS mRNA expression and transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. (C) 2016 Elsevier Inc. All rights reserved.
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| 15. |
- Löfvenborg, J E, et al.
(författare)
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Fatty fish consumption and risk of latent autoimmune diabetes in adults
- 2014
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Ingår i: Nutrition & Diabetes. - : Springer Science and Business Media LLC. - 2044-4052. ; 4, s. e139-
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: It has been suggested that intake of fatty fish may protect against both type 1 and type 2 diabetes. Hypotheses rest on the high marine omega-3 fatty acid eicosapentaenoic acid+docosahexaenoic acid (EPA+DHA) and vitamin D contents, with possible beneficial effects on immune function and glucose metabolism. Our aim was to investigate, for the first time, fatty fish consumption in relation to the risk of latent autoimmune diabetes in adults (LADA).METHODS: Analyses were based on data from a Swedish case-control study with incident cases of LADA (n=89) and type 2 diabetes (n=462) and randomly selected diabetes-free controls (n=1007). Diabetes classification was based on the onset of age (⩾35), glutamic acid decarboxylase autoantibodies, and C-peptide. A validated food frequency questionnaire was used to derive information on previous intake of fish, polyunsaturated long-chain omega-3 fatty acids (n-3 PUFA) and supplementation of fish oil and vitamin D. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression, adjusted for age, gender, body mass index (BMI), family history of diabetes, physical activity, smoking, education, and consumption of alcohol, fruit, vegetables and red meat.RESULTS: Weekly fatty fish consumption (⩾1 vs <1 serving per week), was associated with a reduced risk of LADA but not type 2 diabetes (OR 0.51, 95% CI 0.30-0.87, and 1.01, 95% CI 0.74-1.39, respectively). Similar associations were seen for estimated intake of n-3 PUFA (⩾0.3 g per day; LADA: OR 0.60, 95% CI 0.35-1.03, type 2 diabetes: OR 1.14, 95% CI 0.79-1.58) and fish oil supplementation (LADA: OR 0.47, 95% CI 0.19-1.12, type 2 diabetes: OR 1.58, 95% CI 1.08-2.31).CONCLUSIONS: Our findings suggest that fatty fish consumption may reduce the risk of LADA, possibly through effects of marine-originated omega-3 fatty acids.
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| 16. |
- Löfvenborg, Josefin E., et al.
(författare)
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Sweetened beverage intake and risk of latent autoimmune diabetes in adults (LADA) and type 2 diabetes
- 2016
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Ingår i: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 175:6, s. 605-614
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Sweetened beverage intake is associated with increased risk of type 2 diabetes, but its association with autoimmune diabetes is unclear. We aimed to investigate sweetened beverage intake and risk of latent autoimmune diabetes in adults (LADA); autoimmune diabetes with features of type 2 diabetes. Design/methods: Data from a Swedish population-based study was used, including incident cases of LADA (n = 357) and type 2 diabetes (n = 1136) and randomly selected controls (n = 1371). Diabetes classification was based on onset age (≥35), glutamic acid decarboxylase autoantibodies (GADA) and C-peptide. Sweetened beverage intake information was derived from a validated food frequency questionnaire. ORs adjusted for age, sex, family history of diabetes, education, lifestyle, diet, energy intake and BMI were estimated using logistic regression. Results: Daily intake of >2 servings of sweetened beverages (consumed by 6% of participants) was associated with increased risk of LADA (OR: 1.99, 95% CI: 1.11-3.56), and for each 200 mL daily serving, OR was 1.15 (95% CI: 1.02-1.29). Findings were similar for sugar-sweetened (OR: 1.18, 95% CI: 1.00-1.39) and artificially sweetened beverages (OR: 1.12, 95% CI: 0.95-1.32). Similarly, each daily serving increment in total sweetened beverage conferred 20% higher type 2 diabetes risk (95% CI: 1.07-1.34). In type 2 diabetes patients, high consumers displayed higher HOMA-IR levels (4.5 vs 3.5, P = 0.0002), but lower HOMA-B levels (55 vs 70, P = 0.0378) than non-consumers. Similar tendencies were seen in LADA. Conclusions: High intake of sweetened beverages was associated with increased risk of LADA. The observed relationship resembled that with type 2 diabetes, suggesting common pathways possibly involving insulin resistance.
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| 17. |
- Magnusson, Louise, 1992-
(författare)
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Peripheral immunity in patients with autoimmune endocrine diseases and the influence of physiological adaptions during pregnancy
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes (T1D), Hashimoto’s thyroiditis (HT), Graves’ disease (GD), and autoimmune Addison’s disease (AD) appear to share immunogenetic mechanisms. This idea is not novel, as “autoimmune tautology” is an established concept. An issue with previous studies is that no or few simultaneous comparisons between these autoimmune endocrine diseases have been made. Due to methodological limitations, immune deviations associated with these diseases have also been examined for a limited number of immune cell lineages and analytes. High-dimensional single-cell mass cytometry was thus employed to phenotypically characterise all peripheral CD45+ cell lineages, whilst immune-related proteins in plasma and cell supernatants were analysed by proximity extension assay. Patients with new-onset T1D, HT, and AD had altered frequencies of distinct clusters within antigen-presenting and cytotoxic cell lineages. Importantly, previously unreported alterations of rare cell subsets from patients with HT and AD were identified. The systemic immunoprofile of patients with autoimmune endocrine diseases was in general similar. However, an increased abundance of CDCP1 and SLAMF1 in plasma from patients with T1D, HT, and GD might reflect a higher degree of inflammation and lymphocyte activation.Pregnancy in healthy women entails two important features: 1) an increase in fractional β-cell area and 2) peripheral immunomodulation. The effects of pregnancy on T1D remain nevertheless equivocal, as there are conflicting results on β-cell function and longitudinal analyses on peripheral immunity are lacking. β-cell function and the plasma proteome in pregnant women with long-standing T1D (L-T1D) were therefore examined during three occasions: 1) first trimester, 2) third trimester, and 3) two months postpartum. An oral glucose tolerance test was performed to measure both fasting and stimulated C-peptide concentrations in plasma. Plasma proteins related to cell regulatory and immunological processes were analysed by proximity extension assay. Glucose-induced insulin secretion was regained in pregnant women with L-T1D, which decreased slowly after parturition. The plasma proteome was dynamic during gestation, although few analytes were functionally linked. A recovered β-cell function might be related to elevated plasma levels of prolactin, prokineticin-1, or glucagon. Moreover, reduced plasma levels of proteins related to leukocyte migration, T cell activation, and antigen-presentation might have further protected an improved β-cell function.
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| 18. |
- Olsson, Bob, 1969, et al.
(författare)
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T-cell-mediated cytotoxicity toward platelets in chronic idiopathic thrombocytopenic purpura.
- 2003
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Ingår i: Nature medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 9:9, s. 1123-4
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Tidskriftsartikel (refereegranskat)abstract
- Chronic idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder that is characterized by increased platelet destruction and is believed to be autoantibody mediated. In this study, CD3+ T cells from ITP patients had increased expression of genes involved in cell-mediated cytotoxicity. In addition, cytotoxic cell-mediated lysis of autologous platelets was shown in active ITP. Our data suggest that T-cell-mediated cytotoxicity is an alternative mechanism for platelet destruction in ITP.
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| 19. |
- Osterlund, Maria, et al.
(författare)
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Probing inhibitor-induced conformational changes along the interface between tissue factor and factor VIIa
- 2001
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Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 40:31, s. 9324-9328
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Tidskriftsartikel (refereegranskat)abstract
- Upon injury of a blood vessel, activated factor VII (FVIIa) forms a high-affinity complex with its allosteric regulator, tissue factor (TF), and initiates blood clotting. Active site-inhibited factor VIIa (FVIIai) binds to TF with even higher affinity. We compared the interactions of FVIIai and FVIIa with soluble TF (sTF). Six residues in sTF were individually selected for mutagenesis and site-directed labeling. The residues are distributed along the extensive binding interface, and were chosen because they are known to interact with the different domains of FVIIa. Fluorescent and spin probes were attached to engineered Cys residues to monitor local changes in hydrophobicity, accessibility, and rigidity in the sTF-FVIIa complex upon occupation of the active site of FVIIa. The results show that inhibition of FVIIa caused the structures around the positions in sTF that interact with the protease domain of FVIIa to become more rigid and less accessible to solvent. Thus, the presence of an active site inhibitor renders the interface in this region less flexible and more compact, whereas the interface between sTF and the light chain of FVIIa is unaffected by active site occupancy.
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| 20. |
- Rasouli, Bahareh, et al.
(författare)
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Alcohol and the risk for LADA: results based on the Swedish ESTRID study.
- 2014
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Ingår i: European Journal of Endocrinology. - 1479-683X. ; 171:5, s. 535-543
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Tidskriftsartikel (refereegranskat)abstract
- Objective Moderate alcohol consumption is associated with a reduced risk of type 2 diabetes. Our aim was to investigate whether alcohol consumption is associated with risk of latent autoimmune diabetes in adults (LADA), an autoimmune form of diabetes with features of type 2 diabetes. Design Population-based case-control study Methods We used data from ESTRID case-control study carried out between 2010 and 2013, including 250 incident cases of LADA (glutamic acid decarboxylase antibodies [GADA] positive) and 764 cases of type 2 diabetes (GADA negative), and 1012 randomly selected controls aged ≥35. Logistic regression was used to estimate the odds ratios (OR) of diabetes in relation to alcohol intake, adjusted for age, sex, BMI, family history of diabetes, smoking, and education. Results Alcohol consumption was inversely associated with the risk of type 2 diabetes (OR 0.95, 95% confidence interval (CI); 0.92-0.99 for every 5-g increment in daily intake). Similar results were seen for LADA, but stratification by median GADA levels revealed that the results only pertained to LADA with low GADA (OR 0.85; 95% 0.76-0.94 per 5g alcohol/day), whereas no association was seen with LADA high GADA (OR 1.00, 95% CI; 0.94-1.06 per 5g/day). Every 5-g increment of daily alcohol intake was associated with a 10% increase in GADA levels (p=0.0312), and a10% reduction in HOMA-IR (p=0.0418). Conclusions Our findings indicate that alcohol intake may reduce risk of type 2 diabetes and type 2-like LADA, but has no beneficial effects on diabetes-related autoimmunity.
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| 21. |
- Rasouli, Bahareh, et al.
(författare)
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Alcohol and the risk for latent autoimmune diabetes in adults : results based on Swedish ESTRID study
- 2014
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Ingår i: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 171:5, s. 535-543
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Moderate alcohol consumption is associated with a reduced risk of type 2 diabetes. Our aim was to investigate whether alcohol consumption is associated with the risk of latent autoimmune diabetes in adults (LADA), an autoimmune form of diabetes with features of type 2 diabetes. Design: A population-based case-control study was carried out to investigate the association of alcohol consumption and the risk of LADA. Methods: We used data from the ESTRID case-control study carried out between 2010 and 2013, including 250 incident cases of LADA (glutamic acid decarboxylase antibodies (GADAs) positive) and 764 cases of type 2 diabetes (GADA negative), and 1012 randomly selected controls aged >= 35. Logistic regression was used to estimate the odds ratios (ORs) of diabetes in relation to alcohol intake, adjusted for age, sex, BMI, family history of diabetes, smoking, and education. Results: Alcohol consumption was inversely associated with the risk of type 2 diabetes (OR 0.95, 95% CI 0.92-0.99 for every 5-g increment in daily intake). Similar results were observed for LADA, but stratification by median GADA levels revealed that the results only pertained to LADA with low GADA levels (OR 0.85, 95% CI 0.76-0.94/5 g alcohol per day), whereas no association was observed with LADA having high GADA levels (OR 1.00, 95% CI 0.94-1.06/5 g per day). Every 5-g increment of daily alcohol intake was associated with a 10% increase in GADA levels (P=0.0312), and a 10% reduction in homeostasis model assessment of insulin resistance (P=0.0418). Conclusions: Our findings indicate that alcohol intake may reduce the risk of type 2 diabetes and type 2-like LADA, but has no beneficial effects on diabetes-related autoimmunity.
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| 22. |
- Rasouli, B., et al.
(författare)
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Coffee consumption, genetic susceptibility and risk of latent autoimmune diabetes in adults : A population-based case-control study
- 2018
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Ingår i: Diabetes & Metabolism. - : Elsevier BV. - 1262-3636 .- 1878-1780. ; 44:4, s. 354-360
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Coffee consumption is inversely related to risk of type 2 diabetes (T2D). In contrast, an increased risk of latent autoimmune diabetes in adults (LADA) has been reported in heavy coffee consumers, primarily in a subgroup with stronger autoimmune characteristics. Our study aimed to investigate whether coffee consumption interacts with HLA genotypes in relation to risk of LADA. Methods: This population-based study comprised incident cases of LADA (n = 484) and T2D (n = 1609), and also 885 healthy controls. Information on coffee consumption was collected by food frequency questionnaire. Odds ratios (ORs) with 95% CIs of diabetes were calculated and adjusted for age, gender, BMI, education level, smoking and alcohol intake. Potential interactions between coffee consumption and high-risk HLA genotypes were calculated by attributable proportion (AP) due to interaction. Results: Coffee intake was positively associated with LADA in carriers of high-risk HLA genotypes (OR: 1.14 per cup/day, 95% CI: 1.02–1.28), whereas no association was observed in non-carriers (OR: 1.04, 95% CI: 0.93–1.17). Subjects with both heavy coffee consumption (≥ 4 cups/day) and high-risk HLA genotypes had an OR of 5.74 (95% CI: 3.34–9.88) with an estimated AP of 0.36 (95% CI: 0.01–0.71; P = 0.04370). Conclusion: Our findings suggest that coffee consumption interacts with HLA to promote LADA.
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| 23. |
- Rasouli, Bahareh, et al.
(författare)
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Smoking and the risk of LADA : Results from a Swedish population-based case-control study
- 2016
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 39:5, s. 794-800
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Smoking is an established risk factor for type 2 diabetes. In contrast, it has been proposed that smoking may reduce the risk of latent autoimmune diabetes in adults (LADA), but studies are scarce. We aimed to study the impact of smoking on LADA and type 2 diabetes risks. RESEARCH DESIGN AND METHODS: We used data from a Swedish case-control study including incident case patients with LADA (GAD antibody [GADA] positive, n = 377) and type 2 diabetes (GADA negative, n = 1,188) and control subjects randomly selected from the population (n = 1,472). We calculated odds ratios (ORs) with 95% CIs by logistic regression, adjusted for age, sex, BMI, family history of diabetes, and alcohol consumption. RESULTS: There was no indication of reduced risk of LADA in smokers; instead, heavy smoking was associated with an increased risk of LADA (OR 1.37, 95% CI 1.02-1.84). Heavy smokers had higher levels of HOMA of insulin resistance (9.89 vs. 4.38, P = 0.0479) and HOMA of β-cell function (55.7 vs. 42.5, P = 0.0204), but lower levels of GADA (75 vs. 250, P = 0.0445), compared with never smokers. Smokers also displayedanincreased risk oftype2 diabetes (OR in eversmokers 1.53, 95% CI 1.25-1.88). CONCLUSIONS: In this large population of LADA patients, we did not observe a protective effect of smoking on autoimmunity and the risk of LADA. A protective effect could possibly be masked by a smoking-induced aggravation of insulin resistance, akin to the diabetogenic effect seen in individuals with type 2 diabetes.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Ahlberg, Ernst, et al.
(författare)
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Interpretation of Conformal Prediction Classification Models
- 2015
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Ingår i: STATISTICAL LEARNING AND DATA SCIENCES. - Cham : Springer International Publishing. - 9783319170916 - 9783319170909 ; , s. 323-334
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Konferensbidrag (refereegranskat)abstract
- We present a method for interpretation of conformal prediction models. The discrete gradient of the largest p-value is calculated with respect to object space. A criterion is applied to identify the most important component of the gradient and the corresponding part of the object is visualized. The method is exemplified with data from drug discovery relating chemical compounds to mutagenicity. Furthermore, a comparison is made to already established important subgraphs with respect to mutagenicity and this initial assessment shows very useful results with respect to interpretation of a conformal predictor.
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| 29. |
- Ahlberg, Ernst, et al.
(författare)
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Using conformal prediction to prioritize compound synthesis in drug discovery
- 2017
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Ingår i: Proceedings of Machine Learning Research. - Stockholm : Machine Learning Research. ; , s. 174-184
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Konferensbidrag (refereegranskat)abstract
- The choice of how much money and resources to spend to understand certain problems is of high interest in many areas. This work illustrates how computational models can be more tightly coupled with experiments to generate decision data at lower cost without reducing the quality of the decision. Several different strategies are explored to illustrate the trade off between lowering costs and quality in decisions.AUC is used as a performance metric and the number of objects that can be learnt from is constrained. Some of the strategies described reach AUC values over 0.9 and outperforms strategies that are more random. The strategies that use conformal predictor p-values show varying results, although some are top performing.The application studied is taken from the drug discovery process. In the early stages of this process compounds, that potentially could become marketed drugs, are being routinely tested in experimental assays to understand the distribution and interactions in humans.
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| 30. |
- Ahlqvist, Emma, et al.
(författare)
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Novel subgroups of adult-onset diabetes and their association with outcomes : a data-driven cluster analysis of six variables
- 2018
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Ingår i: The Lancet Diabetes and Endocrinology. - 2213-8587 .- 2213-8595. ; 6:5, s. 361-369
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundDiabetes is presently classified into two main forms, type 1 and type 2 diabetes, but type 2 diabetes in particular is highly heterogeneous. A refined classification could provide a powerful tool to individualise treatment regimens and identify individuals with increased risk of complications at diagnosis.MethodsWe did data-driven cluster analysis (k-means and hierarchical clustering) in patients with newly diagnosed diabetes (n=8980) from the Swedish All New Diabetics in Scania cohort. Clusters were based on six variables (glutamate decarboxylase antibodies, age at diagnosis, BMI, HbA1c, and homoeostatic model assessment 2 estimates of β-cell function and insulin resistance), and were related to prospective data from patient records on development of complications and prescription of medication. Replication was done in three independent cohorts: the Scania Diabetes Registry (n=1466), All New Diabetics in Uppsala (n=844), and Diabetes Registry Vaasa (n=3485). Cox regression and logistic regression were used to compare time to medication, time to reaching the treatment goal, and risk of diabetic complications and genetic associations.FindingsWe identified five replicable clusters of patients with diabetes, which had significantly different patient characteristics and risk of diabetic complications. In particular, individuals in cluster 3 (most resistant to insulin) had significantly higher risk of diabetic kidney disease than individuals in clusters 4 and 5, but had been prescribed similar diabetes treatment. Cluster 2 (insulin deficient) had the highest risk of retinopathy. In support of the clustering, genetic associations in the clusters differed from those seen in traditional type 2 diabetes.InterpretationWe stratified patients into five subgroups with differing disease progression and risk of diabetic complications. This new substratification might eventually help to tailor and target early treatment to patients who would benefit most, thereby representing a first step towards precision medicine in diabetes.
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| 31. |
- Aleman, Soo, et al.
(författare)
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A Risk for Hepatocellular Carcinoma Persists Long-term After Sustained Virologic Response in Patients With Hepatitis C-Associated Liver Cirrhosis
- 2013
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1537-6591 .- 1058-4838. ; 57:2, s. 230-236
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Tidskriftsartikel (refereegranskat)abstract
- Background. The long-term effect of sustained virologic response (SVR) to antiviral therapy on the risk of developing hepatocellular carcinoma (HCC), liver complications, liver-related death, and overall death in hepatitis C virus (HCV)-infected patients with liver cirrhosis is not fully known. Methods. These risks were evaluated during long-term follow-up in 351 patients with HCV-related cirrhosis. One hundred ten patients with SVR, 193 with non-SVR, and 48 who were untreated were included in a multicenter cohort that was initiated in 2001 and prospectively followed up for a mean of 5.3 (SD, 2.8) years. Complementary follow-up data from national registries were used to minimize the loss of patients during follow-up. Results. Six patients with SVR developed HCC at 0.04, 0.64, 2.4, 7.4, 7.4, and 7.6 years, respectively, after achieving SVR. The incidences of HCC, any liver complication, liver-related death, and overall death per 100 person-years were significantly lower in SVR time with 1.0, 0.9, 0.7, and 1.9, compared to 2.3, 3.2, 3.0, and 4.1 in non-SVR and 4.0, 4.9, 4.5, and 5.1 in untreated time. The long-term consequences did not decline significantly after >3 years versus during the first 3 years of follow-up. Conclusions. The risk for HCC, liver decompensation, and death in patients with liver cirrhosis related to HCV was markedly reduced after SVR, but a long-term risk of developing HCC remains for up to 8 years. Cirrhotic patients with HCV who achieve SVR should therefore maintain long-term surveillance for HCC. Future studies aimed to better identify those with remaining long-term risk for HCC are needed.
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| 32. |
- Alvarsson, Jonathan, et al.
(författare)
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Benchmarking Study of Parameter Variation When Using Signature Fingerprints Together with Support Vector Machines
- 2014
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Ingår i: Journal of Chemical Information and Modeling. - : American Chemical Society (ACS). - 1549-9596 .- 1549-960X. ; 54:11, s. 3211-3217
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Tidskriftsartikel (refereegranskat)abstract
- QSAR modeling using molecular signatures and support vector machines with a radial basis function is increasingly used for virtual screening in the drug discovery field. This method has three free parameters: C, ?, and signature height. C is a penalty parameter that limits overfitting, ? controls the width of the radial basis function kernel, and the signature height determines how much of the molecule is described by each atom signature. Determination of optimal values for these parameters is time-consuming. Good default values could therefore save considerable computational cost. The goal of this project was to investigate whether such default values could be found by using seven public QSAR data sets spanning a wide range of end points and using both a bit version and a count version of the molecular signatures. On the basis of the experiments performed, we recommend a parameter set of heights 0 to 2 for the count version of the signature fingerprints and heights 0 to 3 for the bit version. These are in combination with a support vector machine using C in the range of 1 to 100 and gamma in the range of 0.001 to 0.1. When data sets are small or longer run times are not a problem, then there is reason to consider the addition of height 3 to the count fingerprint and a wider grid search. However, marked improvements should not be expected.
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| 33. |
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| 34. |
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| 35. |
- Andersson, Dick, et al.
(författare)
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Contribution of tryptophan residues to the CD spectrum of the extracellular domain of human tissue factor : Application in folding studies and prediction of secondary structure
- 2001
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 268:4, s. 1118-1128
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Tidskriftsartikel (refereegranskat)abstract
- The contribution to the circular dichroism (CD) spectrum made by each of the four Trp residues in the extracellular domain of human tissue factor, sTF (s designates soluble), was determined from difference CD spectra. The individual Trp CD spectra showed that all four residues contributed to the CD spectrum in almost the entire wavelength region investigated (180-305 nm). The sum of the individual spectra of each Trp residue in the near-UV region was qualitatively identical to the wild-type spectrum, clearly demonstrating that the Trp residues are the major contributors to the spectrum in this wavelength region. Trp CD bands interfere with the peptide bands in the far-UV region, leading to uncertainty in the predictions of the amounts of various types of secondary structure. Accordingly, the best prediction of secondary sTF structure content was achieved using a hypothetical Trp-free CD spectrum obtained after subtraction of all individual Trp spectra from the wild-type spectrum. The mutated Trp residues were also exploited as intrinsic probes to monitor the formation of local native-like tertiary structure by kinetic near-UV CD measurements. The global folding reaction was followed in parallel with a novel functional assay that registered the recovery of cofactor activity, i.e. stimulation of the amidolytic activity of Factor VIIa. From these measurements, it was found that sTF appears to regain FVIIa cofactor activity before the final side-chain packing of the Trp residues. The combined kinetic refolding results suggest that the compact asymmetric environments of the individual Trp residues in sTF are formed simultaneously, leading to the conclusion that the native tertiary structure of the whole protein is formed in a cooperative manner.
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| 36. |
- Andersson, Niklas, et al.
(författare)
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Parameter Selection in the Parameter Estimation of Grade Transitions in a Polyethylene Plant
- 2015
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Ingår i: Studies in Engineering and Technology. - : Redfame Publishing. - 2330-2038 .- 2330-2046. ; 3:1, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- A polyethylene plant at Borealis AB is modelled in the Modelica language and considered for parameter estimations at grade transitions. Parameters have been estimated for both the steady-state and the dynamic case using the JModelica.org platform, which offers tools for steady-state parameter estimation and supports simulation with parameter sensitivies. The model contains 31 candidate parameters, giving a huge amount of possible parameter combinations. The best parameter sets have been chosen using a parameter-selection algorithm that identified parameter sets with poor numerical properties. The parameter-selection algorithm reduces the number of parameter sets that is necessary to explore. The steady-state differs from the dynamic case with respect to parameter selection. Validations of the parameter estimations in the dynamic case show a significant reduction in an objective value used to evaluate the quality of the solution from that of the nominal reference, where the nominal parameter values are used.
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| 37. |
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| 38. |
- Andersson, Ola, et al.
(författare)
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Endogenous Communication and Tacit Coordination in Market Entry Games - An explorative experimental study
- 2006
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper explores experimentally the effects of costly communication possibilities in market entry games. It is shown that these effects depend on whether entry costs are symmetric or asymmetric. In the former, but not the latter case, communication possibilities increase coordination success substantially and are likely to generate inferior outcomes for consumers. Furthermore, cost asymmetries provide a tacit coordination cue that is robust to changes in the game and is used by experienced players as a substitute to communication. It is also shown that although communication opens up for aggressive market domination strategies, such strategies are not used often successful.
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| 39. |
- Andersson, Ola, et al.
(författare)
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The impact of stay-at-home policies on individual welfare
- 2022
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Ingår i: Scandinavian Journal of Economics. - : Wiley. - 0347-0520 .- 1467-9442. ; 124:2, s. 340-362
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we perform a choice experiment assessing the impact of stay-at-home policies on individual welfare. We estimate the willingness to accept compensation (WTA) for restricting non-working hours in Sweden during the COVID-19 pandemic. The WTA for a one-month stay-at-home policy is about US$480 per person, or 9.1 percent of Sweden's monthly per capita GDP. Stricter lockdowns require disproportionately higher compensation than more lenient ones, indicating that strict policies are cost-effective only if they are much more successful in slowing the spread of the disease. Moreover, older people have a higher WTA of staying home than the rest of the population.
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| 40. |
- Andersson, Ola, et al.
(författare)
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THE INDIVIDUAL WELFARE COSTS OF STAY-AT-HOME POLICIES
- 2020
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper reports the results of a choice experiment designed to estimate the private welfare costs of stay-at-home policies during the COVID-19 pandemic. The study is conducted on a large and representative sample of the Swedish population. The results suggest that the welfare cost of a one-month stay-at-home policy, restricting non-working hours away from home, amounts to 9.1 percent of qSweden's monthly GDP. The cost can be interpreted as 29,600 quality-adjusted life years (QALYs), which roughly corresponds to between 3,700 and 8,000 COVID-19 fatalities. Moreover, we find that stricter and longer lockdowns are disproportionately more costly than more lenient ones. This result indicates that strict stay-at-home policies are likely to be cost-effective only if they slow the spread of the disease much more than more lenient ones.
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| 41. |
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| 42. |
- Arvidsson McShane, Staffan, 1990-
(författare)
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Confidence Predictions in Pharmaceutical Sciences
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main focus of this thesis has been on Quantitative Structure Activity Relationship (QSAR) modeling using methods producing valid measures of uncertainty. The goal of QSAR is to prospectively predict the outcome from assays, such as ADMET (Absorption, Distribution, Metabolism, Excretion), toxicity and on- and off-target interactions, for novel compounds. QSAR modeling offers an appealing alternative to laboratory work, which is both costly and time-consuming, and can be applied earlier in the development process as candidate drugs can be tested in silico without requiring to synthesize them first. A common theme across the presented papers is the application of conformal and probabilistic prediction models, which are used in order to associate predictions with a level of their reliability – a desirable property that is essential in the stage of decision making. In Paper I we studied approaches on how to utilize biological assay data from legacy systems, in order to improve predictive models. This is otherwise problematic since mixing data from separate systems will cause issues for most machine learning algorithms. We demonstrated that old data could be used to augment the proper training set of a conformal predictor to yield more efficient predictions while preserving model calibration. In Paper II we studied a new approach of predicting metabolic transformations of small molecules based on transformations encoded in SMIRKS format. In this work use used the probabilistic Cross-Venn-ABERS predictor which overall worked well, but had difficulty in modeling the minority class of imbalanced datasets. In Paper III we studied metabolomics data from patients diagnosed with Multiple Sclerosis and found a set of 15 discriminatory metabolites that could be used to classify patients from a validation cohort into one of two sub types of the disease with high accuracy. We further demonstrated that conformal prediction could be useful for tracking the progression of the disease for individual patients, which we exemplified using data from a clinical trial. In Paper IV we introduced CPSign – a software for cheminformatics modeling using conformal and probabilistic methods. CPSign was compared against other regularly used methods for this task, using 32 benchmark datasets, demonstrating that CPSign produces predictive accuracy on par with the best performing methods.
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| 43. |
- Arvidsson McShane, Staffan, et al.
(författare)
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CPSign : conformal prediction for cheminformatics modeling
- 2024
-
Ingår i: Journal of Cheminformatics. - : Springer Nature. - 1758-2946. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- Conformal prediction has seen many applications in pharmaceutical science, being able to calibrate outputs of machine learning models and producing valid prediction intervals. We here present the open source software CPSign that is a complete implementation of conformal prediction for cheminformatics modeling. CPSign implements inductive and transductive conformal prediction for classification and regression, and probabilistic prediction with the Venn-ABERS methodology. The main chemical representation is signatures but other types of descriptors are also supported. The main modeling methodology is support vector machines (SVMs), but additional modeling methods are supported via an extension mechanism, e.g. DeepLearning4J models. We also describe features for visualizing results from conformal models including calibration and efficiency plots, as well as features to publish predictive models as REST services. We compare CPSign against other common cheminformatics modeling approaches including random forest, and a directed message-passing neural network. The results show that CPSign produces robust predictive performance with comparative predictive efficiency, with superior runtime and lower hardware requirements compared to neural network based models. CPSign has been used in several studies and is in production-use in multiple organizations. The ability to work directly with chemical input files, perform descriptor calculation and modeling with SVM in the conformal prediction framework, with a single software package having a low footprint and fast execution time makes CPSign a convenient and yet flexible package for training, deploying, and predicting on chemical data. CPSign can be downloaded from GitHub at https://github.com/arosbio/cpsign .Scientific contribution CPSign provides a single software that allows users to perform data preprocessing, modeling and make predictions directly on chemical structures, using conformal and probabilistic prediction. Building and evaluating new models can be achieved at a high abstraction level, without sacrificing flexibility and predictive performance-showcased with a method evaluation against contemporary modeling approaches, where CPSign performs on par with a state-of-the-art deep learning based model.
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| 44. |
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| 45. |
- Arvidsson, Per-Ola, et al.
(författare)
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Purification and identification of the violaxanthin de-epoxidase as a 43 kDa protein
- 1996
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Ingår i: Photosynthesis Research. - 0166-8595. ; 49:2, s. 119-129
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Tidskriftsartikel (refereegranskat)abstract
- Violaxanthin deepoxidase (VDE) has been purified from spinach (Spinacia oleracea) leaves. The purification included differential sonication of thylakoid membranes, differential (NH4)2SO4 fractionation, gel filtration chromatography and finally either hydrophobic interaction chromatography or anion exchange chromatography. A total purification of more than 5000-fold compared to the original thylakoids enabled the identification of a 43 kDa protein as the VDE, in contrast to earlier reported molecular weight of 54–60 kDa. A detailed comparison was made for the VDE activity and polypeptide pattern for the different fractions throughout the purification and the best correlation was always found for the 43 kDa protein. The highest specific activity obtained was 256 mol g–1 s–1 protein, which is at least 10-fold higher than reported earlier. We estimate that there is 1 VDE molecule per 20–100 electron transport chains. The 43 kDa protein was N-terminally sequenced, after protection of cysteine residues with -mercaptoethanol and iodoacetamid, and a unique sequence of 20 amino acids was obtained. The amino acid composition of the protein revealed a high abundance of charged and polar amino acids and remarkably, 11 cysteine residues. Two other proteins (39.5 kDa and 40 kDa) copurifying with VDE were also N-terminally sequenced. The N-terminal part of the 39.5 kDa protein showed complete sequence identity both with the N-terminal part of cyt b 6 and an internal sequence of polyphenol oxidase.
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| 46. |
- Arvidsson, Per-Ola, et al.
(författare)
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Violaxanthin accessibility and temperature dependency for de-epoxidation in spinach thylakoid membranes
- 1997
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Ingår i: Photosynthesis Research. - 0166-8595. ; 52:1, s. 39-48
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Tidskriftsartikel (refereegranskat)abstract
- Using DTT and iodoacetamide as a novel irreversible method to inhibit endogenous violaxanthin de-epoxidase, we found that violaxanthin could be converted into zeaxanthin from both sides of the thylakoid membrane provided that purified violaxanthin de-epoxidase was added. The maximum conversion was the same from both sides of the membrane. Temperature was found to have a strong influence both on the rate and degree of maximal violaxanthin to zeaxanthin conversion. Thus only 50% conversion of violaxanthin was detected at 4 degreesC, whereas at 25 degreesC and 37 degreesC the degree of conversion was 70% and 80%, respectively. These results were obtained with isolated thylakoids from non-cold acclimated leafs. Pigment analysis of sub-thylakoid membrane domains showed that violaxanthin was evenly distributed between stroma lamellae and grana partitions. This was in contrast to chlorophyll a and beta-carotene which were enriched in stroma lamellae fractions while chlorophyll b, lutein and neoxanthin were enriched in the grana membranes. In combination with added violaxanthin de-epoxidase we found almost the same degree of conversion of violaxanthin to zeaxanthin (73-78%) for different domains of the thylakoid membrane. We conclude that violaxanthin de-epoxidase converts violaxanthin in the lipid matrix and not at the proteins, that violaxanthin does not prefer one particular membrane region or one particular chlorophyll protein complex, and that the xanthophyll cycle pigments are oriented in a vertical manner in order to be accessible from both sides of the membrane when located in the lipid matrix.
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| 47. |
- Arvidsson, Staffan, et al.
(författare)
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Prediction of Metabolic Transformations using Cross Venn-ABERS Predictors
- 2017
-
Ingår i: Conformal and Probabilistic Prediction with Applications (COPA) 2017. ; , s. 118-131
-
Konferensbidrag (refereegranskat)abstract
- Prediction of drug metabolism is an important topic in the drug discovery process, and we here present a study using probabilistic predictions applying Cross Venn-ABERS Predictors (CVAPs) on data for site-of-metabolism. We used a dataset of 73599 biotransformations, applied SMIRKS to define biotransformations of interest and constructed five datasets where chemical structures were represented using signatures descriptors. The results show that CVAP produces well-calibrated predictions for all datasets with good predictive capability, making CVAP an interesting method for further exploration in drug discovery applications.
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| 48. |
- Asad, Samina, et al.
(författare)
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HTR1A a Novel Type 1 Diabetes Susceptibility Gene on Chromosome 5p13-q13
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 7:5
-
Tidskriftsartikel (refereegranskat)abstract
- Background: We have previously performed a genome-wide linkage study in Scandinavian Type 1 diabetes (T1D) families. In the Swedish families, we detected suggestive linkage (LOD less than= 2.2) to the chromosome 5p13-q13 region. The aim of our study was to investigate the linked region in search for possible T1D susceptibility genes. Methodology/Principal Findings: Microsatellites were genotyped in the Scandinavian families to fine-map the previously linked region. Further, SNPs were genotyped in Swedish and Danish families as well as Swedish sporadic cases. In the Swedish families we detected genome-wide significant linkage to the 5-hydroxytryptamine receptor 1A (HTR1A) gene (LOD 3.98, pless than9.8x10(-6)). Markers tagging two separate genes; the ring finger protein 180 (RNF180) and HTR1A showed association to T1D in the Swedish and Danish families (pless than0.002, pless than0.001 respectively). The association was not confirmed in sporadic cases. Conditional analysis indicates that the primary association was to HTR1A. Quantitative PCR show that transcripts of both HTR1A and RNF180 are present in human islets of Langerhans. Moreover, immunohistochemical analysis confirmed the presence of the 5-HTR1A protein in isolated human islets of Langerhans as well as in sections of human pancreas. Conclusions: We have identified and confirmed the association of both HTR1A and RFN180, two genes in high linkage disequilibrium (LD) to T1D in two separate family materials. As both HTR1A and RFN180 were expressed at the mRNA level and HTR1A as protein in human islets of Langerhans, we suggest that HTR1A may affect T1D susceptibility by modulating the initial autoimmune attack or either islet regeneration, insulin release, or both.
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| 49. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Intra-body microwave communication through adipose tissue
- 2017
-
Ingår i: Healthcare technology letters. - : The Institution of Engineering and Technology. - 2053-3713. ; 4:4, s. 115-121
-
Tidskriftsartikel (refereegranskat)abstract
- The human body can act as a medium for the transmission of electromagnetic waves in the wireless body sensor networks context. However, there are transmission losses in biological tissues due to the presence of water and salts. This Letter focuses on lateral intra-body microwave communication through different biological tissue layers and demonstrates the effect of the tissue thicknesses by comparing signal coupling in the channel. For this work, the authors utilise the R-band frequencies since it overlaps the industrial, scientific and medical radio (ISM) band. The channel model in human tissues is proposed based on electromagnetic simulations, validated using equivalent phantom and ex-vivo measurements. The phantom and ex-vivo measurements are compared with simulation modelling. The results show that electromagnetic communication is feasible in the adipose tissue layer with a low attenuation of approximate to 2 dB per 20 mm for phantom measurements and 4 dB per 20 mm for ex-vivo measurements at 2 GHz. Since the dielectric losses of human adipose tissues are almost half of ex-vivo tissue, an attenuation of around 3 dB per 20 mm is expected. The results show that human adipose tissue can be used as an intra-body communication channel.
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| 50. |
- Balboa, Diego, et al.
(författare)
-
Functional, metabolic and transcriptional maturation of human pancreatic islets derived from stem cells.
- 2022
-
Ingår i: Nature Biotechnology. - : Springer Nature. - 1087-0156 .- 1546-1696. ; 40:7, s. 1042-1055
-
Tidskriftsartikel (refereegranskat)abstract
- Transplantation of pancreatic islet cells derived from human pluripotent stem cells is a promising treatment for diabetes. Despite progress in the generation of stem-cell-derived islets (SC-islets), no detailed characterization of their functional properties has been conducted. Here, we generated functionally mature SC-islets using an optimized protocol and benchmarked them comprehensively against primary adult islets. Biphasic glucose-stimulated insulin secretion developed during in vitro maturation, associated with cytoarchitectural reorganization and the increasing presence of alpha cells. Electrophysiology, signaling and exocytosis of SC-islets were similar to those of adult islets. Glucose-responsive insulin secretion was achieved despite differences in glycolytic and mitochondrial glucose metabolism. Single-cell transcriptomics of SC-islets in vitro and throughout 6 months of engraftment in mice revealed a continuous maturation trajectory culminating in a transcriptional landscape closely resembling that of primary islets. Our thorough evaluation of SC-islet maturation highlights their advanced degree of functionality and supports their use in further efforts to understand and combat diabetes.
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