| 1. |
- Morfeldt, E, et al.
(författare)
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Isolated hypervariable regions derived from streptococcal M proteins specifically bind human C4b-binding protein : implications for antigenic variation.
- 2001
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 167:7, s. 3870-7
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Tidskriftsartikel (refereegranskat)abstract
- Antigenic variation in microbial surface proteins represents an apparent paradox, because the variable region must retain an important function, while exhibiting extensive immunological variability. We studied this problem for a group of streptococcal M proteins in which the approximately 50-residue hypervariable regions (HVRs) show essentially no residue identity but nevertheless bind the same ligand, the human complement regulator C4b-binding protein (C4BP). Synthetic peptides derived from different HVRs were found to retain the ability to bind C4BP, implying that the HVR corresponds to a distinct ligand-binding domain that can be studied in isolated form. This finding allowed direct characterization of the ligand-binding properties of isolated HVRs and permitted comparisons between different HVRs in the absence of conserved parts of the M proteins. Affinity chromatography of human serum on immobilized peptides showed that they bound C4BP with high specificity and inhibition experiments indicated that different peptides bound to the same site in C4BP. Different C4BP-binding peptides did not exhibit any immunological cross-reactivity, but structural analysis suggested that they have similar folds. These data show that the HVR of streptococcal M protein can exhibit extreme variability in sequence and immunological properties while retaining a highly specific ligand-binding function.
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| 2. |
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| 3. |
- Andersson, Jonas, 1977-, et al.
(författare)
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Effect of intensive lifestyle intervention on C-reactive protein in subjects with impaired glucose tolerance and obesity : results from a randomized controlled trial with 5-year follow-up
- 2008
-
Ingår i: Biomarkers: biochemical indicators of exposure, response, and susceptibility to chemicals. - : Informa UK Limited. - 1366-5804. ; 13:7, s. 671-679
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Tidskriftsartikel (refereegranskat)abstract
- C-reactive protein (CRP) is a marker of metabolic and cardiovascular disease. To study the effects of lifestyle on CRP in a high-risk population we conducted a randomized controlled trial on 200 obese subjects (BMI > 27 kg m(-2)) with impaired glucose tolerance recruited from primary care settings. They were randomized to either a 1-month stay at a wellness centre focusing on diet, exercise and stress management (intervention group) or 30-60 min of oral and written information on lifestyle intervention (control group). A significant reduction of CRP was observed after 1 month and 1 year in the intervention group. They reduced their CRP levels more than the control group 1 year after intervention (p=0.004). In conclusion lifestyle intervention can decrease CRP in obese individuals with impaired glucose tolerance for up to 1 year. Further research is needed to evaluate whether the CRP level reduction translates into a decreased risk for cardiovascular morbidity.
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| 4. |
- André, Ingemar, et al.
(författare)
-
Streptococcal M protein: Structural studies of the hypervariable region, free and bound to human C4BP
- 2006
-
Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 45:14, s. 4559-4568
-
Tidskriftsartikel (refereegranskat)abstract
- Streptococcus pyogenes is a Gram-positive bacterium that causes several diseases, including acute tonsillitis and toxic shock syndrome. The surface-localized M protein, which is the most extensively studied virulence factor of S. pyogenes, has an similar to 50-residue N-terminal hypervariable region (HVR) that plays a key role in the escape of the host immunity. Despite the extensive sequence variability in this region, many HVRs specifically bind human C4b-binding protein (C4BP), a plasma protein that inhibits complement activation. Although the more conserved parts of M protein are known to have dimeric coiled-coil structure, it is unclear whether the HVR also is a coiled coil. Here, we use nuclear magnetic resonance (NMR) to study the conformational properties of HVRs from M4 and M22 proteins in isolation and in complex with the M protein binding portion of C4BP. We conclude that the HVRs of M4 and M22 are folded as coiled coils and that the folded nucleus of the M4 HVR has a length of similar to 27 residues. Moreover, we demonstrate that the C4BP binding surface of M4-N is found within a region of four heptad repeats. Using molecular modeling, we propose a model for the structure of the M4 HVR that is consistent with our experimental information from NMR spectroscopy.
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| 5. |
- Bengtsson, Torbjörn, et al.
(författare)
-
The periodontal pathogen Porphyromonas gingivalis cleaves apoB-100 and increases the expression of apoM in LDL in whole blood leading to cell proliferation
- 2008
-
Ingår i: Journal of Internal Medicine. - : Institutionen för medicin och hälsa. - 0954-6820 .- 1365-2796. ; 263:5, s. 558-571
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Several studies support an association between periodontal disease and atherosclerosis with a crucial role for the pathogen Porphyromonas gingivalis. This study aims to investigate the proteolytic and oxidative activity of P. gingivalis on LDL in a whole blood system by using a proteomic approach and analyze the effects of P. gingivalis-modifed LDL on cell proliferation.Methods: The cellular effects of P. gingivalis in human whole blood were assessed using lumi-aggregometry analyzing reactive oxygen species (ROS) production and aggregation. Blood was incubated for 30 min with P. gingivalis, whereafter LDL was isolated and a proteomic approach was applied to examine protein expression. LDL-oxidation was determined by analyzing the formation of protein carbonyls. The effects of P. gingivalis-modifed LDL on fibroblast proliferation were studied using the MTS-assay.Results: Incubation of whole blood with P. gingivalis caused an extensive aggregation and ROS-production, indicating platelet and leukocyte activation. LDL prepared from the bacteria-exposed blood showed an increased protein oxidation, elevated levels of apoM and formation of two apoB-100 N-terminal fragments. P. gingivalis-modified LDL markedly increased the growth of fibroblasts. Inhibition of gingipain R suppressed the modification of LDL by P. gingivalis.Conclusions: The ability of P. gingivalis to change the protein expression and the proliferative capacity of LDL may represent a crucial event in periodontitis-associated atherosclerosis.
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| 6. |
- Bergemalm, Daniel, 1977-, et al.
(författare)
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Systemic Inflammation in Preclinical Ulcerative Colitis
- 2021
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Ingår i: Gastroenterology. - : AGA Institute. - 0016-5085 .- 1528-0012. ; 161:5, s. 1526-1539.e9
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Preclinical ulcerative colitis is poorly defined. We aimed to characterize the preclinical systemic inflammation in ulcerative colitis, using a comprehensive set of proteins.Methods: We obtained plasma samples biobanked from individuals who developed ulcerative colitis later in life (n = 72) and matched healthy controls (n = 140) within a population-based screening cohort. We measured 92 proteins related to inflammation using a proximity extension assay. The biologic relevance of these findings was validated in an inception cohort of patients with ulcerative colitis (n = 101) and healthy controls (n = 50). To examine the influence of genetic and environmental factors on these markers, a cohort of healthy twin siblings of patients with ulcerative colitis (n = 41) and matched healthy controls (n = 37) were explored.Results: Six proteins (MMP10, CXCL9, CCL11, SLAMF1, CXCL11 and MCP-1) were up-regulated (P < .05) in preclinical ulcerative colitis compared with controls based on both univariate and multivariable models. Ingenuity Pathway Analyses identified several potential key regulators, including interleukin-1β, tumor necrosis factor, interferon-gamma, oncostatin M, nuclear factor-κB, interleukin-6, and interleukin-4. For validation, we built a multivariable model to predict disease in the inception cohort. The model discriminated treatment-naïve patients with ulcerative colitis from controls with leave-one-out cross-validation (area under the curve = 0.92). Consistently, MMP10, CXCL9, CXCL11, and MCP-1, but not CCL11 and SLAMF1, were significantly up-regulated among the healthy twin siblings, even though their relative abundances seemed higher in incident ulcerative colitis.Conclusions: A set of inflammatory proteins are up-regulated several years before a diagnosis of ulcerative colitis. These proteins were highly predictive of an ulcerative colitis diagnosis, and some seemed to be up-regulated already at exposure to genetic and environmental risk factors.
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| 7. |
- Bergman, Torbjörn, 1957-, et al.
(författare)
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Appendix : On definition and measurement
- 2021
-
Ingår i: Coalition governance in Western Europe. - Oxford : Oxford University Press. - 9780198868484 ; , s. 727-748
-
Bokkapitel (refereegranskat)abstract
- The appendix introduces our empirical study of the coalition life cycle. The structure of each country chapter is based on six core tables, each one capturing a major stage in the coalition life cycle. In the book chapters, the tables help structure the analysis and provide wealth of information and details of the coalition cycle. Nevertheless, the book chapters and this appendix only present a sample of the data and information that we have collected for this research project. For reasons of space, we have had to limit the presentation in the book chapters in terms of time-periods and variables. This appendix presents many more details that are important for readers who are not familiar with the definitions used in coalition research or interested in how particular variables where measured. In addition to the definitions and measurements presented in this appendix, all the data and all the variables are presented in an on-line data appendix at www.erdda.org.
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| 8. |
- Fälker, Knut, 1971-, et al.
(författare)
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The Toll-like receptor 2/1 (TLR2/1) complex initiates human platelet activation via the src/Syk/LAT/PLC gamma 2 signalling cascade
- 2014
-
Ingår i: Cellular Signalling. - New York, USA : Elsevier. - 0898-6568 .- 1873-3913. ; 26:2, s. 279-286
-
Tidskriftsartikel (refereegranskat)abstract
- The specific TLR2/1 complex activator Pam3CSK4 has been shown to provoke prominent activation and aggregation of human non-nucleated platelets. As Pam3CSK4-evoked platelet activation does not employ the major signalling pathway established in nucleated immune cells, we investigated if the TLR2/1 complex on platelets may initiate signalling pathways known to be induced by physiological agonists such as collagen via GPVI or thrombin via PARs. We found that triggering TLR2/1 complex-signalling with Pam3CSK4, in common with that induced via GPVI, and in contrast to that provoked by PARS, involves tyrosine phosphorylation of the adaptor protein LAT as well as of PLC gamma 2 in a src- and Syk-dependent manner. In this respect, we provide evidence that Pam3CSK4 does not cross-activate GPVI. Further, by the use of platelets from a Glanzmann's thrombasthenia patient lacking beta(3), in contrast to findings in nucleated immune cells, we show that the initiation of platelet activation by Pam3CSK4 does not involve integrin beta(3) signalling; whereas the latter, subsequent to intermediate TXA2 synthesis and signalling, was found to be indispensable for proper dense granule secretion and full platelet aggregation. Together, our findings reveal that triggering the TLR2/1 complex with Pam3CSK4 initiates human platelet activation by engaging tyrosine kinases of the src family and Syk, the adaptor protein LAT, as well as the key mediator PLC gamma 2. (C) 2013 Elsevier Inc. All rights reserved.
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| 9. |
- Johansson, Torbjörn, et al.
(författare)
-
Biologisk mångfald i skogslandskapet.
- 1994
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I skogslandskapet är mångfalden av arter och framför allt hotade sådana, koncentrerade till sumpskogar, gammal skog, död ved, och lövträd.Förekomsten av nyckelbiotoper i länet har uppskattats utifrån de ca 5% av skogsmarksarealen som idag är inventerade.Ingenting tyder på att situationen skulle vara väsentligt annorlunda i övriga delar av länet.Endast 2-3% av skogsmarksarealen i länet, inkl reservaten, bedöms utgöra biotoper med så höga naturvärden att de uppfyller kraven för nyckelbiotop.Detta ger en bild av hur mycket av skogen som idag har naturskogskaraktär och därmed också hur omfattande omdaningen av skogslandskapet har varit. Arterna i skogslandskapet påverkas i olika utsträckning av det moderna skogsbruket.
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| 10. |
- Katus, Hugo, et al.
(författare)
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Early diagnosis of acute coronary syndrome
- 2017
-
Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 38:41, s. 3049-3055
-
Forskningsöversikt (refereegranskat)abstract
- The diagnostic evaluation of acute chest pain has been augmented in recent years by advances in the sensitivity and precision of cardiac troponin assays, new biomarkers, improvements in imaging modalities, and release of new clinical decision algorithms. This progress has enabled physicians to diagnose or rule-out acute myocardial infarction earlier after the initial patient presentation, usually in emergency department settings, which may facilitate prompt initiation of evidence-based treatments, investigation of alternative diagnoses for chest pain, or discharge, and permit better utilization of healthcare resources. A non-trivial proportion of patients fall in an indeterminate category according to rule-out algorithms, and minimal evidence-based guidance exists for the optimal evaluation, monitoring, and treatment of these patients. The Cardiovascular Round Table of the ESC proposes approaches for the optimal application of early strategies in clinical practice to improve patient care following the review of recent advances in the early diagnosis of acute coronary syndrome. The following specific 'indeterminate' patient categories were considered: (i) patients with symptoms and high-sensitivity cardiac troponin <99th percentile; (ii) patients with symptoms and high-sensitivity troponin <99th percentile but above the limit of detection; (iii) patients with symptoms and high-sensitivity troponin >99th percentile but without dynamic change; and (iv) patients with symptoms and high-sensitivity troponin >99th percentile and dynamic change but without coronary plaque rupture/erosion/dissection. Definitive evidence is currently lacking to manage these patients whose early diagnosis is 'indeterminate' and these areas of uncertainty should be assigned a high priority for research.
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| 11. |
- Lindahl, Anders, et al.
(författare)
-
Gråborg och S:t Knuts kapell : en berättelse i tid och rum baserad på en studie av det keramiska materialet
- 2008
-
Ingår i: Gråborg på Öland : om en borg, ett kapell och en by. - 9789174023800 ; , s. 67-80
-
Bokkapitel (refereegranskat)abstract
- Gråborg i Algutsrums socken är en av de mest välkända fornborgarna på Öland. Mellan åren 1999 och 2002 har flera mindre forskningsundersökningar utförts av Gråborg och under 1998 genomfördes en undersökning av S:t Knuts kapellruin. En viktig fråga har varit att datera de olika lämningarna, men även att belysa en rad andra viktiga frågor. Här utgör keramikmaterialet en av de mer betydelsefulla källorna. Keramiken är den enskilt största fyndkategorin från undersökningarna, och med hänsyn till bland annat avsaknaden av väldaterade fynd är keramiken den viktigaste artefaktgruppen för att datera de olika kontexterna. Samtidigt vittnar keramiken om social status, proveniens och handelskontakter.
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| 12. |
- Lindahl, Bernt, et al.
(författare)
-
A randomized lifestyle intervention with 5-year follow-up in subjects with impaired glucose tolerance : pronounced short-term impact but long-term adherence problems
- 2009
-
Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 37:4, s. 434-442
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To compare data on cardiovascular risk factor changes in lipids, insulin, proinsulin, fibrinolysis, leptin and C-reactive protein, and on diabetes incidence, in relation to changes in lifestyle. METHODS: The study was a randomized lifestyle intervention trial conducted in northern Sweden between 1995 and 2000, in 168 individuals with impaired glucose tolerance (IGT) and body mass index above 27 at start. The intensive intervention group (n = 83) was subjected to a 1-month residential lifestyle programme. The usual care group (n = 85) participated in a health examination ending with a single counselling session. Follow-up was conducted at 1, 3 and 5 years. RESULTS: At 1-year follow-up, an extensive cardio-metabolic risk factor reduction was demonstrated in the intensive intervention group, along with a 70% decrease of progress to type 2 diabetes. At 5-year follow-up, most of these beneficial effects had disappeared. Reported physical activity and fibre intake as well as high-density lipoprotein cholesterol were still increased, and fasting insulin and proinsulin were lower. CONCLUSIONS: The intervention affected several important cardio-metabolic risk variables beneficially, and reduced the risk for type 2 diabetes, but the effects persisted only as long as the new lifestyle was maintained. Increased physical activity seemed to be the behaviour that was most easy to preserve.
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| 13. |
- Lindahl, Jonas, 1984-, et al.
(författare)
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Övergångsregeringar
- 2018
-
Annan publikation (populärvet., debatt m.m.)
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| 14. |
- Lindahl, Martin, Doktorand, 1985-, et al.
(författare)
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Field test of a silicon carbide metro propulsion system with reduced losses and acoustic noise
- 2021
-
Ingår i: IET Electrical Systems in Transportation. - : John Wiley and Sons Inc. - 2042-9738 .- 2042-9746. ; 11:1, s. 47-57
-
Tidskriftsartikel (refereegranskat)abstract
- Results are reported from a successful field test with a silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) traction inverter. The train has been operated over a 3-month period in the Stockholm metro system. Increased traction inverter power density has been achieved, with volume and weight reductions of 51% and 25%, respectively. Lower power losses permit the use of car motion cooling. A sound pressure level reduction of 9 dB(A) was measured in the field with the higher inverter switching frequency permitted by using SiC. Complementing tests have been performed in the laboratory to compare thermal performance of silicon and SiC in the same power semiconductor housing. Propulsion system power losses are reduced by 19% with SiC. Acoustic noise reductions while increasing switching frequency are also reported. © 2020 The Authors. IET Electrical Systems in Transportation published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.
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| 15. |
- Lindahl, Pernilla, et al.
(författare)
-
Copy number variants in the kallikrein gene cluster.
- 2013
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:7
-
Tidskriftsartikel (refereegranskat)abstract
- The kallikrein gene family (KLK1-KLK15) is the largest contiguous group of protease genes within the human genome and is associated with both risk and outcome of cancer and other diseases. We searched for copy number variants in all KLK genes using quantitative PCR analysis and analysis of inheritance patterns of single nucleotide polymorphisms. Two deletions were identified: one 2235-bp deletion in KLK9 present in 1.2% of alleles, and one 3394-bp deletion in KLK15 present in 4.0% of alleles. Each deletion eliminated one complete exon and created out-of-frame coding that eliminated the catalytic triad of the resulting truncated gene product, which therefore likely is a non-functional protein. Deletion breakpoints identified by DNA sequencing located the KLK9 deletion breakpoint to a long interspersed element (LINE) repeated sequence, while the deletion in KLK15 is located in a single copy sequence. To search for an association between each deletion and risk of prostate cancer (PC), we analyzed a cohort of 667 biopsied men (266 PC cases and 401 men with no evidence of PC at biopsy) using short deletion-specific PCR assays. There was no association between evidence of PC in this cohort and the presence of either gene deletion. Haplotyping revealed a single origin of each deletion, with most recent common ancestor estimates of 3000-8000 and 6000-14 000 years for the deletions in KLK9 and KLK15, respectively. The presence of the deletions on the same haplotypes in 1000 Genomes data of both European and African populations indicate an early origin of both deletions. The old age in combination with homozygous presence of loss-of-function variants suggests that some kallikrein-related peptidases have non-essential functions.
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| 16. |
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| 17. |
- Lindahl, Thomas, et al.
(författare)
-
Overexpression of cyclin E protein is associated with specific mutation types in the p53 gene and poor survival in human breast cancer.
- 2004
-
Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 25:3, s. 375-80
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Tidskriftsartikel (refereegranskat)abstract
- Cyclin E is one of the key regulators of the G(1)/S transition in the cell cycle. Overexpression of cyclin E has been observed in several malignancies and is associated with high proliferation, aberrant expression of other cell cycle regulators and chromosomal instability in vitro. To explore potential associations between cyclin E deregulation and inactivation of the p53 tumor suppressor gene in human breast cancer, we investigated the immunohistochemical expression of cyclin E in paraffin embedded breast cancers from 270 women with known p53 status by cDNA based sequencing of the p53 gene. The breast cancers were divided into three subgroups according to the percentage of cyclin E-positive cells. One hundred and seventy-one patients (63%) had low cyclin E, 72 (27%) medium and 27 (10%) had high cyclin E content. Fifty-six percent (15/27) of the breast cancers with high cyclin E had p53 gene mutations, compared with 14% (24/171) of those with low cyclin E content (P < 0.0001). In p53 mutated breast cancers high cyclin E content was associated with insertions, deletions and nonsense point mutations in the p53 tumor suppressor gene, whereas low cyclin E was linked to p53 missense point mutations. We also observed statistically significant associations between a high cyclin E content and aneuploidy, high S phase, larger tumor size, estrogen receptor negativity, presence of axillary node metastases and high tumor grade. High cyclin E content was associated with poor overall survival in univariate and multivariate analysis (hazard ratio 2.4, 95% confidence interval 1.3-4.5). In summary, our findings demonstrate that overexpression of cyclin E is associated with an aggressive tumor phenotype and specific types of p53 mutations.
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| 18. |
- Nordenskjöld, Anna, 1977-
(författare)
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Unrecognized myocardial infarction and cardiac biochemical markers in patients with stable coronary artery disease
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aim: The overarching aim of the thesis was to explore the occurrence and clinical importance of two manifestations of myocardial injury; unrecognized myocardial injury (UMI) and altered levels of cardiac biochemical markers in patients with stable coronary artery disease (CAD).Methods: A prospective multicenter cohort study investigated the prevalence, localization, size, and prognostic implication of UMI in 235 patients with stable CAD. Late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging and coronary angiography were used. The relationship between UMI and severe CAD and cardiac biochemical markers was explored. In a substudy the short- and longterm individual variation in cardiac troponins I and T (cTnI, cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were investigated.Results: The prevalence of UMI was 25%. Subjects with severe CAD were significantly more likely to exhibit UMI than subjects without CAD. There was a strong association between stenosis ≥70% and presence of UMI in the myocardial segments downstream. The presence of UMI was associated with a significant threefold risk of adverse events during follow up. After adjustments UMI was associated with a nonsignificant numerically doubled risk. The levels of cTnI, NT-proBNP, and Galacin-3 were associated with the presence of UMI in univariate analyses. The association between levels of cTnI and presence of UMI remained significant after adjustment. The individual variation in cTnI, cTnT, and NT-proBNP in subjects with stable CAD appeared similar to the biological variation in healthy individuals.Conclusions: UMI is common and is associated with significant CAD, levels of biochemical markers, and an increased risk for adverse events. A change of >50% is required for a reliable short-term change in cardiac troponins, and a rise of >76% or a fall of >43% is required to detect a long-term reliable change in NT-proBNP.
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| 19. |
- Nylander, Martina, et al.
(författare)
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The periodontal pathogen Porphyromonas gingivalis sensitises human blood platelets to epinephrine
- 2008
-
Ingår i: Platelets. - : Taylor & Francis. - 1369-1635 .- 0953-7104. ; 19:5, s. 352-358
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies indicate connections between periodontitis and atherothrombosis, and the periodontal pathogen Porphyromonas gingivalis has been found within atherosclerotic lesions. P. gingivalis-derived proteases, designated gingipains activate human platelets, probably through a "thrombin-like" activity on protease-activated receptors (PARs). However, the potential interplay between P. gingivalis and other physiological platelet activators has not been investigated. The aim of this study was to elucidate consequences and mechanisms in the interaction between P. gingivalis and the stress hormone epinephrine. By measuring changes in light transmission through platelet suspensions, we found that P. gingivalis provoked aggregation, whereas epinephrine alone never had any effect. Intriguingly, pre-treatment of platelets with a low, sub-threshold number of P. gingivalis (i.e. a density that did not directly provoke platelet aggregation) resulted in a marked aggregation response when epinephrine was added. This synergistic action was not inhibited by the cyclooxygenas inhibitor aspirin. Furthermore, fura-2-measurements revealed that epinephrine caused an intracellular Ca(2+) mobilization in P. gingivalis pre-treated platelets, whereas epinephrine alone had no effect. Inhibition of the arg-specific gingipains, but not the lys-specific gingipains, abolished the aggregation and the Ca(2+) response provoked by epinephrine. Similar results were achieved by separate blockage of platelet alpha(2)-adrenergic receptors and PARs. In conclusion, the present study shows that a sub-threshold number of P. gingivalis sensitizes platelets to epinephrine. We suggest that P. gingivalis-derived arg-specific gingipains activates a small number of PARs on the surface of the platelets. This leads to an unexpected Ca(2+) mobilization and a marked aggregation response when epinephrine subsequently binds to the alpha(2)-adrenergic receptor. The present results are consistent with a direct connection between periodontitis and stress, and describe a novel mechanism that may contribute to pathological platelet activation.
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| 20. |
- Ollas, Patrik, 1987, et al.
(författare)
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Quasi-Dynamic Modelling of DC Operated Ground-Source Heat Pump
- 2020
-
Ingår i: SINTEF Proceedings. - Oslo. - 2387-4295. ; 5, s. 208-213, s. 208-213
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Konferensbidrag (refereegranskat)abstract
- The performance of a conventional ground-source heat pump (GSHP) has been measured in the laboratory with alternating current (AC) and direct current (DC) operation using the standardised points from EN14511:2018. The results from these measurements have been used to modify a variable speed heat pump model in IDA Indoor Climate and Energy (ICE) and the annual performance of AC and DC operation have been simulated for an entire year’s operation at two geographical locations in Sweden. Results show that the energy savings with DC operation from laboratory measurements span between 1.4–5.2% and when simulating the performance for an entire year’s operation, the energy savings vary between 2.5–3.4%. Furthermore, the energy savings from the simulations have been compared to the bin method described in EN14825:2018.
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| 21. |
- Trosten, Torbjörn, 1979-, et al.
(författare)
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Energy Optimal Switching Frequency for a 750V Metro Traction Drive Using Silicon Carbide MOSFET Inverter
- 2018
-
Ingår i: Energy Optimal Switching Frequency for a 750V Metro Traction Drive Using Silicon Carbide MOSFET Inverter.
-
Konferensbidrag (refereegranskat)abstract
- The introduction of Silicon Carbide (SiC) MOSFET based inverters into the traction drive makes it possible to increase the inverter switching frequency and reduce energy consumption. This paper describes how to model switching frequency dependent losses in the traction drive and compares the calculated losses to measurements done on a newly developed SiC MOSFET based traction drive. The results from the developed loss models of motor and inverter agrees well with the results from energy measurements. This paper concludes that the energy use of the traction motor and inverter can be simulated well using simple models where skin-effect losses in the motor are modelled in detailed. This paper also concludes that in terms of energy efficiency, the optimal switching frequency using a SiC MOSFET based inverter, is in the range of 3-6 kHz.
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| 22. |
- Wennberg, Patrik, 1972-, et al.
(författare)
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The effects of commuting activity and occupational and leisure time physical activity on risk of myocardial infarction
- 2006
-
Ingår i: European Journal of Cardiovascular Prevention & Rehabilitation. - : Wolters Kluwer. - 1741-8267 .- 1741-8275. ; 13:6, s. 924-930
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Tidskriftsartikel (refereegranskat)abstract
- AB Background: Risk reduction of myocardial infarction has been shown for leisure time physical activity. The results of studies on occupational physical activity and risk of myocardial infarction are incongruous and studies on commuting activity are scarce. The aim of this study was to investigate how commuting activity, occupational physical activity and leisure time physical activity were associated with risk of future first myocardial infarction.Design: We used a prospective incident case-referent study design nested in Vasterbotten Intervention Program and the Northern Sweden MONICA study.Methods: Commuting habits, occupational physical activity, leisure time physical activity and cardiovascular risk factors were assessed at baseline screening and compared in 583 cases (20% women) with a first myocardial infarction and 2098 matched referents.Results: Regular car commuting was associated with increased risk of myocardial infarction versus commuting by bus, cycling or walking [odds ratio (OR) 1.74; 95% confidence interval (CI), 1.20-2.52] after multivariate adjustment. High versus low leisure time physical activity was associated with reduced risk of myocardial infarction (OR 0.69; 95% CI, 0.50-0.95) after adjustment for occupational physical activity and commuting activity, but the association was not statistically significant after further multivariate adjustment. After multivariate adjustment we observed a reduced risk for myocardial infarction in men with moderate (OR 0.70; 95% CI, 0.50-0.98) or high (OR 0.67; 95% CI, 0.42-1.08) versus low occupational physical activity.Conclusions: We found a clear association between car commuting and a first myocardial infarction and a corresponding inverse association with leisure time physical activity, while the impact of occupational physical activity on the risk of myocardial infarction was weaker. (C) 2006 European Society of Cardiology
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| 23. |
- Whiss, Per A., 1966-, et al.
(författare)
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Acute Effects of Nicotine Infusion on Platelets in Nicotine Users with Normal and Impaired Renal Function
- 2000
-
Ingår i: Toxicology and Applied Pharmacology. - : Elsevier BV. - 0041-008X .- 1096-0333. ; 163:2, s. 95-104
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Tidskriftsartikel (refereegranskat)abstract
- The role of platelets in cardiovascular disease associated with smoking is becoming more established, but the effects of nicotine on platelets are unclear. Nicotine therapy is used for smoking cessation in both health and disease. Consequently, the effects of nicotine on platelets are of particular significance in disorders such as renal disease, which is associated with defective platelet function, increased cardiovascular morbidity, and altered nicotine metabolism. Thus, the aim of the present study was to investigate the acute effects of nicotine infusion (NI) on platelets in seven healthy subjects (HS) and seven patients with renal failure (RF). All subjects were nicotine users and had refrained from using nicotine for 36 h before NI. Blood was collected before, immediately after, and 2 h after NI. The plasma concentrations of nicotine and its main metabolite cotinine were determined by gas chromatography. Platelet responsiveness was assessed by aggregometry and flow cytometry in whole blood (P-selectin surface expression, fibrinogen- and von Willebrand factor-binding), P-selectin expression in isolated platelets, and immunoassays of platelet release (β-thromboglobulin, platelet factor 4, and soluble P-selectin) and nitric oxide (NO) products. The plasma levels of cotinine, but not nicotine, were significantly higher in RF compared to HS at all time points. In both groups, collagen-induced platelet aggregation was restrained immediately after NI, when the plasma concentration of nicotine was maximal, and was restored after 2 h. Two hours after NI, activation-dependent P-selectin surface expression in isolated platelets increased in both groups. This increased platelet responsiveness occurred simultaneously with a significant increase of plasma cotinine and a decrease of NO products. Thus, the present study suggests that nicotine, directly or through some secondary mechanism or metabolite, only slightly potentiates some of the platelet responses. Renal failure appears not to influence the effects of nicotine on platelets.
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