SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Lindahl Tomas) "

Sökning: WFRF:(Lindahl Tomas)

  • Resultat 1-50 av 362
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Karlsson, Anna, 1985-, et al. (författare)
  • The effect of tinzaparin on biomarkers in FIGO stages III-IV ovarian cancer patients undergoing neoadjuvant chemotherapy – the TABANETOC trial: study protocol for a randomized clinical multicenter trial
  • 2024
  • Ingår i: Acta Oncologica. - Uppsala : Medical Journals Sweden. - 0284-186X .- 1651-226X. ; 63, s. 581-585
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Tinzaparin, a low-molecular weight heparin (LMWH), has shown anti-neoplastic properties in animal models and in in vitro studies of human cancer cell lines. The reduction of CA-125 levels during neoadjuvant chemotherapy (NACT) in patients with epithelial ovarian cancer (EOC) co-varies with the prognosis; the larger the decrease in CA-125, the better the prognosis.Purpose: This study aims to evaluate the potential anti-neoplastic effects of tinzaparin by investigating changes in serum CA-125 levels in advanced EOC patients who receive NACT.Material and methods: This is an open randomized multicenter pilot trial. Forty patients with EOC selected to receive NACT will be randomized 1:1 to receive daily addition of tinzaparin or no tinzaparin. The processing and treatment of the patients will otherwise follow the recommendations in the Swedish National Guidelines for Ovarian Cancer. Before every cycle of chemotherapy, preoperatively, and 3 weeks after the last cycle of chemotherapy, a panel of biomarkers, including CA-125, will be measured.Patients: Inclusion criteria are women aged 18 years or older, World Health Organization performance status 0–1, histologically confirmed high-grade serous, endometrioid or clear cell EOC, International Federation of Gynecology and Obstetrics (FIGO) stages III-IV. In addition, a CA-125 level of ≥ 250 kIE/L at diagnosis. Exclusion criteria are contraindications to LMWH, ongoing or recent treatment with unfractionated heparin, LMWH, warfarin or non-vitamin K antagonist oral anticoagulants.Interpretation: This study will make an important contribution to the knowledge of the anti-neoplastic effects of tinzaparin in EOC patients and may thus guide the planning of a future study on the impact of tinzaparin on survival in EOC. 
  •  
2.
  • Mårald, Erland, 1970-, et al. (författare)
  • Forest governance and management across time : developing a new forest social contract
  • 2017
  • Bok (refereegranskat)abstract
    • The influence of the past, and of the future on current-time tradeoffs in the forest arena are particularly relevant given the long-term successions in forest landscapes and the hundred years' rotations in forestry. Historically established path dependencies and conflicts determine our present situation and delimit what is possible to achieve. Similarly, future trends and desires have a large influence on decision making. Nevertheless, decisions about forest governance and management are always made in the present – in the present-time appraisal of the developed situation, future alternatives and in negotiation between different perspectives, interests, and actors.This book explores historic and future outlooks as well as current tradeoffs and methods in forest governance and management. It emphasizes the generality and complexity with empirical data from Sweden and internationally. It first investigates, from a historical perspective, how previous forest policies and discourses have influenced current forest governance and management. Second, it considers methods to explore alternative forest futures and how the results from such investigations may influence the present. Third, it examines current methods of balancing tradeoffs in decision-making among ecosystem services. Based on the findings the authors develop an integrated approach – Reflexive Forestry – to support exchange of knowledge and understandings to enable capacity building and the establishment of common ground. Such societal agreements, or what the authors elaborate as forest social contracts, are sets of relational commitment between involved actors that may generate mutual action and a common directionality to meet contemporary challenges.
  •  
3.
  • Rohin Rajan, Meenu, et al. (författare)
  • Comparative analysis of obesity-related cardiometabolic and renal biomarkers in human plasma and serum.
  • 2019
  • Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The search for biomarkers associated with obesity-related diseases is ongoing, but it is not clear whether plasma and serum can be used interchangeably in this process. Here we used high-throughput screening to analyze 358 proteins and 76 lipids, selected because of their relevance to obesity-associated diseases, in plasma and serum from age- and sex-matched lean and obese humans. Most of the proteins/lipids had similar concentrations in plasma and serum, but a subset showed significant differences. Notably, a key marker of cardiovascular disease PAI-1 showed a difference in concentration between the obese and lean groups only in plasma. Furthermore, some biomarkers showed poor correlations between plasma and serum, including PCSK9, an important regulator of cholesterol homeostasis. Collectively, our results show that the choice of biofluid may impact study outcome when screening for obesity-related biomarkers and we identify several markers where this will be the case.
  •  
4.
  • Abrego, Nerea, et al. (författare)
  • Accounting for environmental variation in co-occurrence modelling reveals the importance of positive interactions in root-associated fungal communities
  • 2020
  • Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 29:14, s. 2736-2746
  • Tidskriftsartikel (refereegranskat)abstract
    • Understanding the role of interspecific interactions in shaping ecological communities is one of the central goals in community ecology. In fungal communities, measuring interspecific interactions directly is challenging because these communities are composed of large numbers of species, many of which are unculturable. An indirect way of assessing the role of interspecific interactions in determining community structure is to identify the species co-occurrences that are not constrained by environmental conditions. In this study, we investigated co-occurrences among root-associated fungi, asking whether fungi co-occur more or less strongly than expected based on the environmental conditions and the host plant species examined. We generated molecular data on root-associated fungi of five plant species evenly sampled along an elevational gradient at a high arctic site. We analysed the data using a joint species distribution modelling approach that allowed us to identify those co-occurrences that could be explained by the environmental conditions and the host plant species, as well as those co-occurrences that remained unexplained and thus more probably reflect interactive associations. Our results indicate that not only negative but also positive interactions play an important role in shaping microbial communities in arctic plant roots. In particular, we found that mycorrhizal fungi are especially prone to positively co-occur with other fungal species. Our results bring new understanding to the structure of arctic interaction networks by suggesting that interactions among root-associated fungi are predominantly positive.
  •  
5.
  • Abrego, Nerea, et al. (författare)
  • Higher host plant specialization of root-associated endophytes than mycorrhizal fungi along an arctic elevational gradient
  • 2020
  • Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 10:16, s. 8989-9002
  • Tidskriftsartikel (refereegranskat)abstract
    • How community-level specialization differs among groups of organisms, and changes along environmental gradients, is fundamental to understanding the mechanisms influencing ecological communities. In this paper, we investigate the specialization of root-associated fungi for plant species, asking whether the level of specialization varies with elevation. For this, we applied DNA barcoding based on the ITS region to root samples of five plant species equivalently sampled along an elevational gradient at a high arctic site. To assess whether the level of specialization changed with elevation and whether the observed patterns varied between mycorrhizal and endophytic fungi, we applied a joint species distribution modeling approach. Our results show that host plant specialization is not environmentally constrained in arctic root-associated fungal communities, since there was no evidence for changing specialization with elevation, even if the composition of root-associated fungal communities changed substantially. However, the level of specialization for particular plant species differed among fungal groups, root-associated endophytic fungal communities being highly specialized on particular host species, and mycorrhizal fungi showing almost no signs of specialization. Our results suggest that plant identity affects associated mycorrhizal and endophytic fungi differently, highlighting the need of considering both endophytic and mycorrhizal fungi when studying specialization in root-associated fungal communities.
  •  
6.
  • af Geijerstam, Peder, Doktorand, 1983-, et al. (författare)
  • P-selectin and C-reactive protein in relation to home blood pressure and coronary calcification: a SCAPIS substudy
  • 2024
  • Ingår i: Journal of Hypertension. - : Lippincott Williams & Wilkins. - 0263-6352 .- 1473-5598.
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Soluble P-selectin (sP-selectin) and high-sensitivity C-reactive protein (hsCRP) have previously been associated with hypertension, but the relation with out-of-office blood pressure (BP) and coronary artery calcification score is unknown. We aimed to examine the relationship between sP-selectin, hsCRP and home BP, as well as coronary artery calcification score and carotid artery plaques.Methods: In the Swedish CArdioPulmonary bioImage Study (SCAPIS), 5057 randomly selected participants were evaluated with office and home BP using the semi-automatic Omron M10-IT device. For this cross-sectional study, participants with sP-selectin <4 standard deviations above mean and hsCRP <5 mg/l, representing low-grade inflammation, were included. Using generalized linear models, these inflammatory markers were evaluated in relation to BP classifications, as well as coronary artery calcification score and carotid artery plaques.Results: Of participants, 4548 were included in the analyses. The median age was 57.2 (53.4–61.2) years, and 775 (17.0%) reported taking medication for hypertension. Participants in the highest quartile of sP-selectin [odds ratio (OR) 1.67, 95% confidence interval (CI) 1.40–1.98, P < 0.001] and hsCRP [OR 2.25, (95% CI 1.89–2.60), P < 0.001] were more likely to have sustained hypertension. Participants in the highest quartile of hsCRP were also more likely to have masked hypertension, OR (95% CI) 2.31 (1.72–3.10), P < 0.001 and carotid artery plaques, OR (95% CI) 1.21 (1.05–1.38), P = 0.007.Conclusion: Increased sP-selectin and hsCRP were independently associated with sustained hypertension. These findings indicate an association between hypertension and platelet activity, as expressed by sP-selectin.
  •  
7.
  • Alabas, Oras A., et al. (författare)
  • Sex Differences in Treatments, Relative Survival, and Excess Mortality Following Acute Myocardial Infarction : National Cohort Study Using the SWEDEHEART Registry
  • 2017
  • Ingår i: Journal of the American Heart Association. - : WILEY. - 2047-9980. ; 6:12
  • Tidskriftsartikel (refereegranskat)abstract
    • Background - This study assessed sex differences in treatments, all-cause mortality, relative survival, and excess mortality following acute myocardial infarction.Methods and Results - A population-based cohort of all hospitals providing acute myocardial infarction care in Sweden (SWEDEHEART [Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies]) from 2003 to 2013 was included in the analysis. Excess mortality rate ratios (EMRRs), adjusted for clinical characteristics and guideline-indicated treatments after matching by age, sex, and year to background mortality data, were estimated. Although there were no sex differences in all-cause mortality adjusted for age, year of hospitalization, and comorbidities for ST-segment-elevation myocardial infarction (STEMI) and non-STEMI at 1 year (mortality rate ratio: 1.01 [95% confidence interval (CI), 0.96-1.05] and 0.97 [95% CI, 0.95-.99], respectively) and 5 years (mortality rate ratio: 1.03 [95% CI, 0.99-1.07] and 0.97 [95% CI, 0.95-.99], respectively), excess mortality was higher among women compared with men for STEMI and non-STEMI at 1 year (EMRR: 1.89 [95% CI, 1.66-2.16] and 1.20 [95% CI, 1.16-1.24], respectively) and 5 years (EMRR: 1.60 [95% CI, 1.48-1.72] and 1.26 [95% CI, 1.21-1.32], respectively). After further adjustment for the use of guideline-indicated treatments, excess mortality among women with non-STEMI was not significant at 1 year (EMRR: 1.01 [95% CI, 0.97-1.04]) and slightly higher at 5 years (EMRR: 1.07 [95% CI, 1.02-1.12]). For STEMI, adjustment for treatments attenuated the excess mortality for women at 1 year (EMRR: 1.43 [95% CI, 1.26-1.62]) and 5 years (EMRR: 1.31 [95% CI, 1.19-1.43]).Conclusions - Women with acute myocardial infarction did not have statistically different all-cause mortality, but had higher excess mortality compared with men that was attenuated after adjustment for the use of guideline-indicated treatments. This suggests that improved adherence to guideline recommendations for the treatment of acute myocardial infarction may reduce premature cardiovascular death among women.
  •  
8.
  • Alabas, Oras A., et al. (författare)
  • Statistics on mortality following acute myocardial infarction in 842 897 Europeans
  • 2020
  • Ingår i: Cardiovascular Research. - : OXFORD UNIV PRESS. - 0008-6363 .- 1755-3245. ; 116:1, s. 149-157
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims: To compare ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) mortality between Sweden and the UK, adjusting for background population rates of expected death, case mix, and treatments.Methods and results: National data were collected from hospitals in Sweden [n = 73 hospitals, 180 368 patients, Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART)] and the UK [n = 247, 662 529 patients, Myocardial Ischaemia National Audit Project (MINAP)] between 2003 and 2013. There were lower rates of revascularization [STEMI (43.8% vs. 74.9%); NSTEMI (27.5% vs. 43.6%)] and pharmacotherapies at time of hospital discharge including [aspirin (82.9% vs. 90.2%) and (79.9% vs. 88.0%), beta-blockers (73.4% vs. 86.4%) and (65.3% vs. 85.1%)] in the UK compared with Sweden, respectively. Standardized net probability of death (NPD) between admission and 1 month was higher in the UK for STEMI [8.0 (95% confidence interval 7.4-8.5) vs. 6.7 (6.5-6.9)] and NSTEMI [6.8 (6.4-7.2) vs. 4.9 (4.7-5.0)]. Between 6 months and 1 year and more than 1 year, NPD remained higher in the UK for NSTEMI [2.9 (2.5-3.3) vs. 2.3 (2.2-2.5)] and [21.4 (20.0-22.8) vs. 18.3 (17.6-19.0)], but was similar for STEMI [0.7 (0.4-1.0) vs. 0.9 (0.7-1.0)] and [8.4 (6.7-10.1) vs. 8.3 (7.5-9.1)].Conclusion: Short-term mortality following STEMI and NSTEMI was higher in the UK compared with Sweden. Mid- and longer-term mortality remained higher in the UK for NSTEMI but was similar for STEMI. Differences in mortality may be due to differential use of guideline-indicated treatments.
  •  
9.
  • Albrektsson, Tomas, 1945, et al. (författare)
  • Histologic investigations on 33 retrieved Nobelpharma implants.
  • 1993
  • Ingår i: Clinical materials. - 0267-6605. ; 12:1, s. 1-9
  • Tidskriftsartikel (refereegranskat)abstract
    • Thirty Nobelpharma implants were retrieved from 17 patients despite a remaining clinical stability, after between 1 and 16 years of clinical function. The reasons for implant removal were bone resorption in combination with soft tissue disorders, psychological causes, implant fracture and post mortem cases. When measured at the cortical passage, there was an average of 84.9% direct bone-to-implant contact and 81.8% average surface bone area in individual threads as evaluated in a computerized morphometric system at the light microscopic level.
  •  
10.
  • Alehagen, Urban, et al. (författare)
  • Cystatin C and NT-proBNP, a powerful combination of biomarkers for predicting cardiovascular mortality in elderly patients with heart failure : results from a 10-year study in primary care
  • 2009
  • Ingår i: EUROPEAN JOURNAL OF HEART FAILURE. - : Wiley. - 1388-9842. ; 11:4, s. 354-360
  • Tidskriftsartikel (refereegranskat)abstract
    • Heart failure (HF) is common among the elderly patients. It is essential to identify those at high risk in order to optimize the use of resources. We aimed to evaluate whether a combination of two biomarkers might give better prognostic information about the risk of cardiovascular (CV) mortality in patients with symptoms associated with HF, compared with only one biomarker. Four hundred and sixty-four primary health-care patients (mean age 73 years, range 65-87) with symptoms of HF were examined. All patients were evaluated using Doppler echocardiography and blood samples, including measurement of cystatin C and NT-proBNP. The patients were followed over a 10-year period. Patients with serum cystatin C levels within the highest quartile had almost three times the risk (HR: 2.92; 95% CI: 1.23-4.90) of CV mortality compared with those patients who had levels within the first, second, or third quartiles. If, at the same time, the patient had a plasma concentration of NT-proBNP within the highest quartile, the risk increased to andgt; 13 times (HR: 13.61; 95% CI: 2.56-72.24) during 10 years of follow-up or andgt; 17 times (HR: 17.04; 95% CI: 1.80-163.39) after 5 years of follow-up. Combined analysis of cystatin C and NT-proBNP could provide important prognostic information among elderly patients in the community with symptoms of HF.
  •  
11.
  • Alehagen, Urban, 1951-, et al. (författare)
  • Dietary Supplementation with Selenium and Coenzyme Q10 Prevents Increase in Plasma D-Dimer While Lowering Cardiovascular Mortality in an Elderly Swedish Population.
  • 2021
  • Ingår i: Nutrients. - Basel : MDPI. - 2072-6643. ; 13:4, s. 43-56
  • Tidskriftsartikel (refereegranskat)abstract
    • A low intake of selenium is associated with increased cardiovascular mortality. This could be reduced by supplementation with selenium and coenzyme Q10. D-dimer, a fragment of fibrin mirroring fibrinolysis, is a biomarker of thromboembolism, increased inflammation, endothelial dysfunction and is associated with cardiovascular mortality in ischemic heart disease. The objective was to examine the impact of selenium and coenzyme Q10 on the level of D-dimer, and its relationship to cardiovascular mortality. D-dimer was measured in 213 individuals at the start and after 48 months of a randomised double-blind placebo-controlled trial with selenium yeast (200 µg/day) and coenzyme Q10 (200 mg/day) (n = 106) or placebo (n = 107). The follow-up time was 4.9 years. All included individuals were low in selenium (mean 67 μg/L, SD 16.8). The differences in D-dimer concentration were evaluated by the use of T-tests, repeated measures of variance and ANCOVA analyses. At the end, a significantly lower D-dimer concentration was observed in the active treatment group in comparison with those on placebo (p = 0.006). Although D-dimer values at baseline were weakly associated with high-sensitive CRP, while being more strongly associated with soluble tumour necrosis factor receptor 1 and sP-selectin, controlling for these in the analysis there was an independent effect on D-dimer. In participants with a D-dimer level above median at baseline, the supplementation resulted in significantly lower cardiovascular mortality compared to those on placebo (p = 0.014). All results were validated with a persisting significant difference between the two groups. Therefore, supplementation with selenium and coenzyme Q10 in a group of elderly low in selenium and coenzyme Q10 prevented an increase in D-dimer and reduced the risk of cardiovascular mortality in comparison with the placebo group. The obtained results also illustrate important associations between inflammation, endothelial function and cardiovascular risk.
  •  
12.
  • Alehagen, Urban, 1951-, et al. (författare)
  • Elevated D-dimer level is an independent risk factor for cardiovascular death in out-patients with symptoms compatible with heart failure
  • 2004
  • Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 92:6, s. 1250-1258
  • Tidskriftsartikel (refereegranskat)abstract
    • D-dimer, a marker of fibrin turnover, exhibits many interesting properties as a biological marker of thrombosis. Some of the properties of D-dimer might also be used to provide additional information about patients with heart failure. In this study, we evaluate the prognostic information acquired from D-dimer concerning increased risk of cardiovascular mortality in an elderly population with symptoms associated with heart failure. A cardiologist examined 458 elderly patients, out of 548 invited, attending primary care for symptoms of dyspnoea, fatigue and/or peripheral oedema and assessed NYHA functional class and cardiac function. Abnormal systolic function was defined as EF <40% on Doppler echocardiography. Abnormal diastolic function was defined as reduced E/A ratio and/or an abnormal pattern of pulmonary venous flow. Blood samples were drawn, and BNP and D-dimer were analysed. D-dimer was analysed using an automated micro-latex assay. A statistical analysis was performed to identify the prognostic value of increased plasma concentration of D-dimer. Results showed that during a median follow-up period of 5.5 years, 68 (14%) patients died of cardiovascular disease. No gender difference was noted. A plasma concentration of D-dimer >0.25mg/L increased the risk almost 4-fold. In conclusion, D-dimer is an independent risk factor for cardiovascular mortality that may be used to risk-stratify patients with heart failure. © 2004 Schattauer GmbH, Stuttgart.
  •  
13.
  • Alehagen, Urban, et al. (författare)
  • Levels of sP-selectin and hs-CRP Decrease with Dietary Intervention with Selenium and Coenzyme Q10 Combined: A Secondary Analysis of a Randomized Clinical Trial
  • 2015
  • Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 10:9, s. e0137680-
  • Tidskriftsartikel (refereegranskat)abstract
    • Background/Objectives Inflammation and oxidative stress are central in many disease states. The major anti-oxidative enzymes contain selenium. The selenium intake in Europe is low, and supplementation with selenium and coenzyme Q(10) , important anti-oxidants, was evaluated in a previous study. The aim of this study was to evaluate response on the inflammatory biomarkers C-reactive protein, and sP-selectin, and their possible impact on cardiovascular mortality. Subjects/Methods 437 elderly individuals were included in the study. Clinical examination, echocardiography, electrocardiography and blood samples were drawn. The intervention time was 48 months, and median follow-up was 5.2 years. The effects on inflammation/atherosclerosis were evaluated through analyses of CRP and sP-selectin. Evaluations of the effect of the intervention was performed using repeated measures of variance. All mortality was registered, and endpoints of mortality were assessed by Kaplan-Meier plots. Results The placebo group showed a CRP level of 4.8 ng/mL at the start, and 5.1 ng/mL at the study end. The active supplementation group showed a CRP level of 4.1 ng/mL at the start, and 2.1 ng/mL at the study end. SP-selectin exhibited a level of 56.6mg/mL at the start in the placebo group and 72.3 mg/mL at the study end, and in the active group the corresponding figures were 55.9 mg/mL and 58.0 mg/mL. A significantly smaller increase was demonstrated through repeated measurements of the two biomarkers in those on active supplementation. Active supplementation showed an effect on the CRP and sP-selectin levels, irrespective of the biomarker levels. Reduced cardiovascular mortality was demonstrated in both those with high and low levels of CRP and sP-selectin in the active supplementation group. Conclusion CRP and sP-selectin showed significant changes reflecting effects on inflammation and atherosclerosis in those given selenium and coenzyme Q(10) combined. A reduced cardiovascular mortality could be demonstrated in the active group, irrespective of biomarker level. This result should be regarded as hypothesis-generating, and it is hoped it will stimulate more research in the area.
  •  
14.
  • Alehagen, Urban, et al. (författare)
  • Low plasma concentrations of coagulation factors II, VII and XI indicate increased risk among elderly with symptoms of heart failure.
  • 2010
  • Ingår i: Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis. - 1473-5733. ; 21:1, s. 62-9
  • Tidskriftsartikel (refereegranskat)abstract
    • Heart failure is a serious condition, and it is, therefore, important to identify patients at high risk as early as possible in order to initiate appropriate treatment. The condition results in complicated disease mechanisms including disturbances in blood coagulation. The aim of the present study was to evaluate whether low plasma concentrations of coagulation factors (F) II, VII and XI influence cardiovascular mortality in an elderly population with possible heart failure. A cardiologist evaluated 450 elderly patients who attended primary healthcare because of symptoms associated with heart failure. He recorded new patient history, conducted a clinical examination, took blood samples, determined concentrations of B-type natriuretic peptide and FII, FVII, FXI and performed Doppler echocardiography. The patients were followed over almost a 10-year period during which all mortality was registered. In patients with suspected heart failure, those with low plasma concentrations of FII, FVII, FXI or all had a significantly higher mortality rate during the follow-up period of 10 years as compared with those with higher plasma concentrations, in contrast with findings in previous reports on patients with acute coronary syndromes. In the group with a plasma concentration of the first versus the ninth decile of FII, FVII, FXI or all, the risk of cardiovascular mortality increased two to three times.
  •  
15.
  • Alehagen, Urban, 1951-, et al. (författare)
  • Significant decrease of von Willebrand factor and plasminogen activator inhibitor-1 by providing supplementation with selenium and coenzyme Q10 to an elderly population with a low selenium status
  • 2020
  • Ingår i: European Journal of Nutrition. - : Springer Science and Business Media LLC. - 1436-6207 .- 1436-6215. ; 59:8, s. 3581-3590
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: Endothelial dysfunction and inflammation are conditions which fuel atherosclerosis and ischaemic heart disease. We have previously reported reduced cardiovascular (CV) mortality following supplementation with selenium and coenzyme Q10 to 443 elderly individuals with low selenium status (mean 67 μg/L) for 4 years. Here, we wanted to evaluate a possible association between the supplementation and the plasma concentrations of the von Willebrand factor (vWf), and the plasminogen activator inhibitor-1 (PAI-1), as they, besides other functions, are also strongly associated with endothelial function.METHODS: In this sub-study, 308 individuals (active substance: 157, placebo: 151) were included. Blood samples were drawn after 6 and 36 months and vWf and PAI-1 were determined in plasma by ELISA. Changes in concentrations of the biomarkers were evaluated by the use of T tests, repeated measures of variance, and ANCOVA analyses.RESULTS: The active treatment group presented a lower level of vWf after 36 months compared with the placebo group (1.08 U/mL vs. 5.10 U/mL; p = 0.0007). The results were validated through the repeated measures of variance evaluation. The PAI-1 levels showed an equally significant decrease in the active group (26.2 ng/mL vs. 49.2 ng/mL; p = 0.0002) and were also validated through repeated measures of variance evaluation.CONCLUSION: In this sub-study on elderly receiving selenium and coenzyme Q10, or placebo we found significantly lower levels of vWf and PAI-1 in the active treatment group as compared to the placebo group. We interpret this as a better endothelial function because of the intervention, which accords with a previous finding of reduced CV mortality.
  •  
16.
  • Alfredsson, Joakim, et al. (författare)
  • Individual long-term variation of platelet reactivity in patients with dual antiplatelet therapy after myocardial infarction.
  • 2019
  • Ingår i: Platelets. - : Informa UK Limited. - 0953-7104 .- 1369-1635. ; 30:5, s. 572-578
  • Tidskriftsartikel (refereegranskat)abstract
    • There is a large inter-individual variation in response to clopidogrel treatment, and previous studies have indicated higher risk of thrombotic events in those with high residual platelet reactivity (HPR). Less is known about individual variation over time. The aim of this prospective cohort study was to investigate intra-individual variation in platelet reactivity. Platelet aggregation in whole blood was assessed in 77 patients, at 3 days, 8 days and 6 months after admission for acute myocardial infarction and loading dose of clopidogrel. All patients were treated with aspirin and clopidogrel through 6-month follow-up. We found a significant increase in median ADP-stimulated aggregation from third to eighth day (195 vs. 250 AU*min, p-value = 0.001) but not from day 8 to 6 months (250 vs. 223 AU*min, p-value = 0.666). There was no significant change in the overall rate of HPR (15.6% vs 20.8%, p-value 0.503) or low platelet reactivity (LPR) (37.7% vs 33.8%, p-value = 0.609) from day 8 to 6-month follow-up. In contrast, more than one in four changed HPR status, 15.6% from non-HPR to HPR and 10.4% HPR to non-HPR. A shift in LPR status appeared even more frequent, occurring in about one of three patients. In spite of similar median aggregation and rate of HPR during 6-month follow-up, about one in four of the patients changed HPR status and one in three changed LPR status. This may be important information for a concept of risk stratification based on a single aggregation value early after an acute coronary syndromes.
  •  
17.
  • Alfredsson, Joakim, et al. (författare)
  • Large early variation of residual platelet reactivity in Acute Coronary Syndrome patients treated with clopidogrel : Results from Assessing Platelet Activity in Coronary Heart Disease (APACHE).
  • 2015
  • Ingår i: Thrombosis Research. - : Pergamon Press. - 0049-3848 .- 1879-2472. ; 136:2, s. 335-340
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: There is a large inter-individual variation in response to clopidogrel treatment and previous studies have indicated higher risk of thrombotic events in patients with high residual platelet reactivity (HRPR), but the optimal time-point for testing is not established. The aim of this study was to investigate the optimal time-point for aggregometry testing and the risk of major adverse cardiac events associated with HRPR.METHOD AND RESULTS: We included 125 patients with ACS (73 with STEMI, and 71 received abciximab). The prevalence of HRPR varied substantially over time. The rate of HRPR in patients treated and not treated with abciximab were 43% vs 67% (p=0.01) before, 2% vs 23% (p=0.001) 6-8h after, 8% vs 9% (p=0.749) 3days after, and 23% vs 12% (p=0.138) 7-9 days after loading dose of clopidogrel. We found HRPR in 18% of the patients but only four ischemic events during 6months follow-up, with no significant difference between HRPR patients compared to the rest of the population. There were 3 TIMI major bleedings, all of which occurred in the low residual platelet reactivity (LRPR) group.CONCLUSION: There is a large variation in platelet reactivity over time, also depending on adjunctive therapy, which has a large impact on optimal time-point for assessment. We found HRPR in almost 1 in 5 patients, but very few MACE, and not significantly higher in HRPR patients. In a contemporary ACS population, with low risk for stent thrombosis, the predictive value of HRPR for ischemic events will probably be low.
  •  
18.
  • Algaba, Juan-Carlos, et al. (författare)
  • Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
  • 2021
  • Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
  • Forskningsöversikt (refereegranskat)abstract
    • In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
  •  
19.
  •  
20.
  • Andell, Pontus, et al. (författare)
  • Oxygen therapy in suspected acute myocardial infarction and concurrent normoxemic chronic obstructive pulmonary disease : a prespecified subgroup analysis from the DETO2X-AMI trial.
  • 2020
  • Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 2048-8726 .- 2048-8734. ; 9:8, s. 984-992
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: The DETermination of the role of Oxygen in suspected Acute Myocardial Infarction (DETO2X-AMI) trial did not find any benefit of oxygen therapy compared to ambient air in normoxemic patients with suspected acute myocardial infarction. Patients with chronic obstructive pulmonary disease may both benefit and be harmed by supplemental oxygen. Thus we evaluated the effect of routine oxygen therapy compared to ambient air in normoxemic chronic obstructive pulmonary disease patients with suspected acute myocardial infarction.METHODS AND RESULTS: =0.77]); there were no significant treatment-by-chronic obstructive pulmonary disease interactions.CONCLUSIONS: Although chronic obstructive pulmonary disease patients had twice the mortality rate compared to non-chronic obstructive pulmonary disease patients, this prespecified subgroup analysis from the DETO2X-AMI trial on oxygen therapy versus ambient air in normoxemic chronic obstructive pulmonary disease patients with suspected acute myocardial infarction revealed no evidence for benefit of routine oxygen therapy consistent with the main trial's findings.CLINICAL TRIALS REGISTRATION: NCT02290080.
  •  
21.
  •  
22.
  • Arbring, Kerstin, et al. (författare)
  • Comparison of prothrombin time (INR) results and main characteristics of patients on warfarin treatment in primary health care centers and anticoagulation clinics
  • 2013
  • Ingår i: BMC Health Services Research. - : BioMed Central. - 1472-6963. ; 13
  • Tidskriftsartikel (refereegranskat)abstract
    • BackgroundOral anticoagulant therapy is used to prevent thrombosis in patients with atrial fibrillation (AF), venous thrombosis and prosthetic heart valves. The introduction of new therapies emphasizes the need to discern the best practice for the patients remaining on warfarin treatment. This study compares patient characteristics and therapeutic control in two settings managing warfarin treatment: Swedish primary health care centers (PHCC) and specialized anticoagulation clinics (ACC).MethodsProthrombin time (PT) test results reported as International Normalized Ratio (INR) were collected for five consecutive days from patients on warfarin treatment; 564 PHCC and 927 ACC patients. Therapeutic control was calculated as PT test results in relation to intended therapeutic range (TR). Mann–Whitney Rank Sum Test and Chi2 test were used for statistical comparisons.ResultsThe PHCC patients were older than the ACC patients, 76 v. 70 years (p<0.01) with a predominance of men in both groups. The reasons for treating differed between the groups. Seventy-two percent of PHCC patients and 66% of ACC patients had a PT-INR within the intended TR (p<0.05). Men generally had better results than women (72% v. 63%, p<0.001) and particularly in the PHCC group v. the ACC group (78% v. 69%, p<0.01).PT-INR above intended TR was significantly more common in the ACC setting, (p<0.05), for women overall (p<0.01), for women in the PHCC setting, and for ACC men (p<0.05).ConclusionsIn this study both settings achieved good therapeutic control of warfarin treatment with a minor advantage for PHCC over ACC, and better results for men, especially in the PHCC setting. As patient characteristics differ between the PHCC and ACC, it is important to conduct further randomized studies to discern the best practice locally for warfarin management also after the introduction of new drugs.
  •  
23.
  •  
24.
  • Arbring, Kerstin, 1961- (författare)
  • Two worlds, one goal : A Clinician’s Perspective on Laboratory Analyses in Anticoagulant Treatment
  • 2023
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Almost precisely a century ago, in the 1920s and 1930s, cattle bled to death in North America after being fed moldy hay containing sweet clover, the yellow Melilotus officinalis, and the white Melilotus albus. The toxic substance in the hay inhibiting blood coagulation was identified and named dicumarol. Further development resulted in warfarin, an oral anticoagulant that has been used for over 70 years and still is, even though newer direct-acting oral anticoagulants (DOACs) are mainly replacing it. For some patients, warfarin is still the drug of choice. A safe warfarin treatment needs repeated blood sample analysis (PT-INR), and with the new DOACs come new laboratory challenges. The aim of this thesis was to investigate ways laboratory methods can contribute to improving oral anticoagulant treatment. Paper I explores genetic variants of the enzyme targeted by warfarin, VKORC1. The result shows that the haplotype VKORC1*2 is the most important of the VKORC1 haplotypes for warfarin dosage, with a lower dose requirement. The VKORC1*2 haplotype was also related to more unstable PT-INR levels. Paper II describes a cross-section study comparing warfarin treatment control, as PT-INRs within the intended therapeutic range, in primary health care centers (PHCCs) and specialized anticoagulation clinics (ACCs). Both settings showed good therapeutic control, with at least as good therapeutic control in the PHCCs as in the ACCs. Today, almost all warfarin treatment in our region is centralized to ACCs. Paper III focuses on the modification of a point-of-care PT method. A ratio of PT from two different dilutions of each patient sample was calculated and used as an indirect measure of DOAC activity. There were close correlations between the PT ratio and drug concentrations measured at the hospital laboratory. The detection level varies between DOACs and may limit its use in some situations. Paper IV evaluated the MRX PT DOAC, an assay based on the PT ratio principle. It was found to be able to detect potentially interfering DOAC levels in plasma samples. Confirmatory testing is recommended, as is sensitivity improvement for the detection of specific interferences.   
  •  
25.
  • Arvidsson, Sara, 1977-, et al. (författare)
  • Detection of surface bound complement at increasing serum anticoagulant concentrations.
  • 2008
  • Ingår i: Colloids and surfaces. B, Biointerfaces. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 62:2, s. 214-9
  • Tidskriftsartikel (refereegranskat)abstract
    • Surface mediated immune complement activation can be detected by a variety of antibody utilizing methods such as ELISA, fluorescence- or radiolabelling techniques, QCM, and ellipsometry. In the present work we investigated how the common anticoagulants heparin, dalteparin, fondaparinux and sodium citrate affected the binding of anti-complement factor 3c (anti-C3c) on a model complement activator surface, immobilised IgG, after incubation in human blood serum. The results show, as expected, that different anticoagulants affect the antibody binding differently. Increasing amounts of heparin, dalteparin and sodium citrate in normal serum resulted in a decreasing anti-C3c binding. The antibody deposition was not sensitive for the fondaparinux concentration. Surprisingly high concentrations of anti-coagulantia were needed to completely eradicate the antibody binding. Experiments in EGTA-serum showed that anticoagulants interfered directly with both the classical and alternative pathways. Control C3a-des arg ELISA measurements show that the lowered antibody surface binding was not a result of complement depletion in serum. Kallikrein generation by hydrophilic glass surfaces was not affected by high anticoagulant concentrations.
  •  
26.
  • Axelsson Rosén, Stina, et al. (författare)
  • In vitro effects of antipsychotics on human platelet adhesion and aggregation and plasma coagulation
  • 2007
  • Ingår i: Clinical and experimental pharmacology & physiology. - : Wiley. - 0305-1870 .- 1440-1681. ; 34:8, s. 775-780
  • Tidskriftsartikel (refereegranskat)abstract
    • 1. Several studies suggest an association between venous thromboembolism and the use of antipsychotic drugs, especially clozapine, but the biological mechanisms are unknown. It has been suggested that antipsychotic drugs enhance aggregation of platelets and thereby increase the risk of venous thrombosis. The purpose of the present study was to examine the effects of clozapine and its main metabolite, N-desmethyl clozapine, as well as olanzapine, risperidone and haloperidol, on platelet adhesion and aggregation and on plasma coagulation in vitro. 2. Blood was collected from healthy subjects free of medication. Platelet adhesion to different protein surfaces and aggregation were measured in microplates. The coagulation methods of activated partial thromboplastin time (APTT) and prothrombin time were performed in platelet-poor plasma. 3. Clozapine was the only compound that increased platelet adhesion and aggregation and shortened APTT. The effect appeared at therapeutic concentrations and was significant but weak. 4. This weak effect of clozapine on haemostasis may explain, in part, the association of this compound and venous thromboembolism. © 2007 The Authors.
  •  
27.
  • Baron, Tomasz, et al. (författare)
  • Impact on Long-Term Mortality of Presence of Obstructive Coronary Artery Disease and Classification of Myocardial Infarction
  • 2016
  • Ingår i: American Journal of Medicine. - : Elsevier BV. - 0002-9343 .- 1555-7162. ; 129:4, s. 398-406
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: In contrast to the associated-with-thromboembolic-event type 1 myocardial infarction, type 2 myocardial infarction is caused by acute imbalance between oxygen supply and demand of myocardium. Type 2 myocardial infarction may be present in patients with or without obstructive coronary artery disease, but knowledge about patient characteristics, treatments, and outcome in relation to coronary artery status is lacking. We aimed to compare background characteristics, triggering mechanisms, treatment, and long-term prognosis in a large real-life cohort of patients with type 1 and type 2 myocardial infarction with and without obstructive coronary artery disease.METHODS: All 41,817 consecutive patients with type 1 and type 2 myocardial infarction registered in the Swedish myocardial infarction registry (SWEDEHEART) who underwent coronary angiography between January 1, 2011 and December 31, 2013, with the last follow-up on December 31, 2014, were studied.RESULTS: In 92.8% of 40,501 patients classified as type 1 and in 52.5% of patients classified as type 2 myocardial infarction, presence of an obstructive coronary artery disease could be shown. Within the patients with obstructive coronary artery disease, those with type 2 myocardial infarction were older, and had more comorbidities and smaller necrosis as compared with type 1 myocardial infarction. In contrast, there was almost no difference in risk profile and extent of myocardial infarction between type 1 and type 2 myocardial infarction patients with nonobstructive coronary artery stenosis. The crude long-term mortality was higher in type 2 as compared with type 1 myocardial infarction with obstructive coronary artery disease (hazard ratio [HR] 1.72; 95% confidence interval [CI], 1.45-2.03), but was lower after adjustment (HR 0.76; 95% CI, 0.61-0.94). In myocardial infarction patients with nonobstructive coronary artery stenosis, the mortality risk was similar regardless of the clinical myocardial infarction type (crude HR 1.14; 95% CI, 0.84-1.55; adjusted HR 0.82; 95% CI, 0.52-1.29).CONCLUSIONS: The substantial differences in risk factors, treatment, and outcome in patients with type 1 and type 2 myocardial infarction with obstructive coronary artery disease supports the relevance of the division between type 1 and type 2 in this population. On the contrary, in patients with nonobstructive coronary artery stenosis, irrespective of the clinical type, a similar risk profile, extent of necrosis, and longterm prognosis were observed, indicating that distinction between type 1 and type 2 myocardial infarction in these patients seems to be inappropriate.
  •  
28.
  •  
29.
  • Baron, Tomasz, et al. (författare)
  • Type 2 myocardial infarction in clinical practice.
  • 2015
  • Ingår i: Heart. - : BMJ. - 1355-6037 .- 1468-201X. ; 101:2, s. 101-106
  • Tidskriftsartikel (refereegranskat)abstract
    • We aimed to assess differences in incidence, clinical features, current treatment strategies and outcome in patients with type 2 vs. type 1 acute myocardial infarction (AMI).
  •  
30.
  •  
31.
  • Bian, Li, et al. (författare)
  • Rutinmässig screening med APTT är inte indicerad före operation : [Routine screening with APTT is not indicated before surgery
  • 2022
  • Ingår i: Läkartidningen. - : Sveriges Läkarförbund. - 0023-7205 .- 1652-7518. ; 119
  • Forskningsöversikt (refereegranskat)abstract
    • Activated partial thromboplastin time (APTT) is widely practiced in preoperative screening. The value of using this test to predict the risk of perioperative bleeding is not well documented in Sweden. In this article, a literature review is performed to determine whether unselected APTT testing can predict abnormal perioperative bleeding. The current literature does not support coagulation screening with APTT in routine perioperative bleeding assessment, as preoperative screening with APTT has a low sensitivity for detection of clinically significant bleeding disorder. While a comprehensive bleeding history is crucial, the APTT test should only be performed on patients with a history of increased bleeding tendency. The conclusion of this literature review is that patients with a negative bleeding history do not require routine screening with APTT prior to surgery, which, if implemented, would lead to a more cost-effective perioperative routine.
  •  
32.
  • Björses, Katarina, et al. (författare)
  • In vitro and in vivo evaluation of chemically modified degradable starch microspheres for topical haemostasis
  • 2011
  • Ingår i: ACTA BIOMATERIALIA. - : Elsevier Science B.V. Amsterdam. - 1742-7061 .- 1878-7568. ; 7:6, s. 2558-2565
  • Tidskriftsartikel (refereegranskat)abstract
    • Degradable starch microspheres (DSMs) are starch chains cross-linked with epichlorhydrin, forming glycerol-ether links. DSMs have been used for many years for temporary vascular occlusion and drug delivery in treatment of malignancies. They are also approved and used for topical haemostasis by absorbing excess fluid from the blood and concentrating endogenous coagulation factors, thereby facilitating haemostasis. This mechanism of action is not sufficient for larger bleedings in current chemical formulations of DSMs, and modification of DSMs to trigger activation of platelets or coagulation would be required for use in such applications. Chemical modifications of DSMs with N-octenyl succinic anhydride, chloroacetic acid, acetic anhydride, diethylaminoethyl chloride and ellagic acid were performed and evaluated in vitro with thrombin generation and platelet adhesion tests, and in vivo using an experimental renal bleeding model in rat. DSMs modified to activate platelets in vitro were superior in haemostatic capacity in vivo. Further studies with non-toxic substances are warranted to confirm these results and develop the DSM as a more effective topical haemostatic agent.
  •  
33.
  • Body, Richard, et al. (författare)
  • The Use of Very Low Concentrations of High-sensitivity Troponin T to Rule Out Acute Myocardial Infarction Using a Single Blood Test
  • 2016
  • Ingår i: Academic Emergency Medicine. - : Wiley. - 1069-6563 .- 1553-2712. ; 23:9, s. 1005-1013
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Recent single-center and retrospective studies suggest that acute myocardial infarction (AMI) could be immediately excluded without serial sampling in patients with initial high-sensitivity cardiac troponin T (hs-cTnT) levels below the limit of detection (LoD) of the assay and no electrocardiogram (ECG) ischemia. Objective: We aimed to determine the external validity of those findings in a multicenter study at 12 sites in nine countries. Methods: TRAPID-AMI was a prospective diagnostic cohort study including patients with suspected cardiac chest pain within 6 hours of peak symptoms. Blood drawn on arrival was centrally tested for hs-cTnT (Roche; 99th percentile = 14 ng/L, LoD = 5 ng/L). All patients underwent serial troponin sampling over 4-14 hours. The primary outcome, prevalent AMI, was adjudicated based on sensitive troponin I (Siemens Ultra) levels. Major adverse cardiac events (MACE) including AMI, death, or rehospitalization for acute coronary syndrome with coronary revascularization were determined after 30 days. Results: We included 1,282 patients, of whom 213 (16.6%) had AMI and 231 (18.0%) developed MACE. Of 560 (43.7%) patients with initial hs-cTnT levels below the LoD, four (0.7%) had AMI. In total, 471 (36.7%) patients had both initial hs-cTnT levels below the LoD and no ECG ischemia. These patients had a 0.4% (n = 2) probability of AMI, giving 99.1% (95% confidence interval [CI] = 96.7% to 99.9%) sensitivity and 99.6% (95% CI = 98.5% to 100.0%) negative predictive value. The incidence of MACE in this group was 1.3% (95% CI = 0.5% to 2.8%). Conclusions: In the absence of ECG ischemia, the detection of very low concentrations of hs-cTnT at admission seems to allow rapid, safe exclusion of AMI in one-third of patients without serial sampling. This could be used alongside careful clinical assessment to help reduce unnecessary hospital admissions.
  •  
34.
  • Boij, Roland, et al. (författare)
  • Biomarkers of Coagulation, Inflammation, and Angiogenesis are Independently Associated with Preeclampsia
  • 2012
  • Ingår i: AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY. - : John Wiley and Sons. - 1046-7408 .- 8755-8920. ; 68:3, s. 258-270
  • Tidskriftsartikel (refereegranskat)abstract
    • Problem Although preeclampsia has been associated with inflammation, coagulation, and angiogenesis, their correlation and relative contribution are unknown. Method of Study About 114 women with preeclampsia, 31 with early onset (EOP) and 83 with late onset preeclampsia (LOP), and 100 normal pregnant controls were included. A broad panel of 32 biomarkers reflecting coagulation, inflammation, and angiogenesis was analyzed. Results Preeclampsia was associated with decreased antithrombin, IL-4 and placental growth factor levels and with increased C3a, pentraxin-3, and sFlt-1 levels, with more marked differences in the EOP group. The Th1-associated chemokines CXCL10 and CXCL11 were significantly higher in the preeclampsia and EOP group than in controls, respectively. No correlations between the biomarkers were found in preeclampsia. Multivariate logistic regression tests confirmed the results. Conclusions Cytokines, chemokines and complement activation seem to be part of a Th1-like inflammatory reaction in preeclampsia, most pronounced in EOP, where chemokines may be more useful than cytokines as biomarkers. Biomarkers were not correlated suggesting partly independent or in time separated mechanisms.
  •  
35.
  •  
36.
  • Boknäs, Niklas, et al. (författare)
  • Associations between hemostatic markers and mortality in COVID-19-Compounding effects of D-dimer, antithrombin and PAP complex
  • 2022
  • Ingår i: Thrombosis Research. - : Pergamon-Elsevier Science Ltd. - 0049-3848 .- 1879-2472. ; 213, s. 97-104
  • Tidskriftsartikel (refereegranskat)abstract
    • In this single-center cohort study, we applied a panel of laboratory markers to characterize hemostatic function in 217 consecutive patients that underwent testing for COVID-19 as they were admitted to Linkoping ¨ University Hospital between April and June 2020. In the 96 patients that tested positive for SARS-CoV-2 (COVID-19+), the cumulative incidences of death and venous thromboembolism were 24.0% and 19.8% as compared to 12.4% (p = 0.031) and 11.6% (p = 0.13) in the 121 patients that tested negative (COVID-19− ). In COVID-19+ patients, we found pronounced increases in plasma levels of von Willebrand factor (vWF) and fibrinogen. Excess mortality was observed in COVID-19+ patients with the following aberrations in hemostatic markers: high D-dimer, low antithrombin or low plasmin-antiplasmin complex (PAP) formation, with Odds Ratios (OR) for death of 4.7 (95% confidence interval (CI95) 1.7–12.9; p = 0.003) for D-dimer >0.5 mg/L, 5.9 (CI95 1.8–19.7; p = 0.004) for antithrombin (AT) ˂0.85 kIU/l and 4.9 (CI95 1.3–18.3; p = 0.019) for PAP < 1000 μg/L. Compounding increases in mortality was observed in COVID-19+ patients with combined defects in markers of fibrinolysis and coagulation, with ORs for death of 15.7 (CI95 4.3–57; p < 0.001) for patients with PAP <1000 μg/L and D-dimer >0.5 mg/L and 15.5 (CI95 2.8–87, p = 0.002) for patients with PAP <1000 μg/L and AT ˂0.85 kIU/L. We observed an elevated fraction of incompletely degraded D-dimer fragments in COVID-19+ patients with low PAP, indicating impaired fibrinolytic breakdown of cross-linked fibrin. 
  •  
37.
  • Boknäs, Niklas, et al. (författare)
  • Contact activation : important to consider when measuring the contribution of tissue factor-bearing microparticles to thrombin generation using phospholipid-containing reagents
  • 2014
  • Ingår i: Journal of Thrombosis and Haemostasis. - : John Wiley & Sons. - 1538-7933 .- 1538-7836. ; 12:4, s. 515-518
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: A commercial MP reagent containing phospholipids is used for thrombin generation (TG) measurements to estimate the procoagulant activity of microparticles (MPs). Previous reports have shown that contact activation affects TG when TF levels are low, and that addition of phospholipids might augment this effect.Objectives: To quantify the impact of contact activation on TG in the presence of phospholipids and low/no TF, as is the case using a commercially available MP-reagent. Methods Thrombin generation was analyzed using MP- or platelet-rich plasma (PRP)-reagent in the presence and absence of corn trypsin inhibitor and anti-TF antibodies, respectively. To quantify the impact of different experimental parameters on contact activation, microparticle-depleted plasma was analyzed in the presence of different concentrations of phospholipids, TF and/or contact activating agents (kaolin).Results: Even with low contact activating blood collection tubes, substantial thrombin generation was observed with the MP-reagent, but this was completely inhibited by addition of corn trypsin inhibitor. Control experiments illustrate that the phospholipids in the reagent play a major role in enhancing TG initiated by FXIIa. Even with the PRP-reagent, which is recommended for determining the content of phospholipids from MPs, TG was partly dependent on contact activation.Conclusions: Contact activation plays a major role in TG when using reagents/samples containing phospholipids but little or no tissue factor. This needs to be considered and accounted for in future clinical studies using TG to assess the procoagulant activity of MPs.
  •  
38.
  • Boknäs, Niklas, et al. (författare)
  • Flow cytometry-based platelet function testing is predictive of symptom burden in a cohort of bleeders
  • 2018
  • Ingår i: Platelets. - : Taylor & Francis. - 0953-7104 .- 1369-1635. ; 29:5, s. 512-519
  • Tidskriftsartikel (refereegranskat)abstract
    • Platelet function disorders (PFDs) are common in patients with mild bleeding disorders (MBDs), yet the significance of laboratory findings suggestive of a PFD remain unclear due to the lack of evidence for a clinical correlation between the test results and the patient phenotype. Herein, we present the results from a study evaluating the potential utility of platelet function testing using whole-blood flow cytometry in a cohort of 105 patients undergoing investigation for MBD. Subjects were evaluated with a test panel comprising two different activation markers (fibrinogen binding and P-selectin exposure) and four physiologically relevant platelet agonists (ADP, PAR1-AP, PAR4-AP, and CRP-XL). Abnormal test results were identified by comparison with reference ranges constructed from 24 healthy controls or with the fifth percentile of the entire patient cohort. We found that the abnormal test results are predictive of bleeding symptom severity, and that the greatest predictive strength was achieved using a subset of the panel, comparing measurements of fibrinogen binding after activation with all four agonists with the fifth percentile of the patient cohort (p = 0.00008, hazard ratio 8.7; 95% CI 2.5-40). Our results suggest that whole-blood flow cytometry-based platelet function testing could become a feasible alternative for the investigation of MBDs. We also show that platelet function testing using whole-blood flow cytometry could provide a clinically relevant quantitative assessment of platelet-related hemostasis.
  •  
39.
  •  
40.
  • Boknäs, Niklas, 1979- (författare)
  • Studies on interfaces between primary and secondary hemostasis
  • 2016
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Our conceptual understanding of hemostasis is still heavily influenced by outdated experimental models wherein the hemostatic activity of platelets and coagulation factors are understood and studied in isolation. Although perhaps convenient for researchers and clinicians, this reductionist view is negated by an ever increasing body of evidence pointing towards an intimate relationship between the two phases of hemostasis, marked by strong interdependence. In this thesis, I have focused on factual and proposed interfaces between primary and secondary hemostasis, and on how these interfaces can be studied.In my first project, we zoomed in on the mechanisms behind the well-known phenomenon of thrombin-induced platelet activation, an important event linking secondary to primary hemostasis. In our study, we examined how thrombin makes use of certain domains for high-affinity binding to substrates, called exosite I and II, to activate platelets via PAR4. We show that thrombin-induced platelet activation via PAR4 is critically dependent on exosite II, and that blockage of exosite II with different substances virtually eliminates PAR4 activation. Apart from providing new insights into the mechanisms by which thrombin activates PAR4, these results expand our knowledge of the antithrombotic actions of various endogenous proteins such as members of the serpin superfamily, which inhibit interactions with exosite II. Additionally, we show that inhibition of exosite II could be a feasible pharmacological strategy for achieving selective blockade of PAR4.In my second project, we examined the controversial issue of whether platelets can initiate the coagulation cascade by means of contact activation, a hypothesis which, if true, could provide a direct link between primary and secondary hemostasis. In contrast to previous results, our findings falsify this hypothesis, and show that some of the erroneous conclusions drawn from earlier studies can be explained by inappropriate experimental models unsuitable for the study of plateletcoagulation interfaces.My third project comprised an assessment of the methodological difficulties encountered when trying to measure the ability of platelets to initiate secondary hemostasis by the release of microparticles expressing tissue factor. Our study shows that the functional assays available for this purpose are highly susceptible to error caused by artificial contact activation. These results could help to improve the methodology of future research and thus pave the way for new insights into the roles of tissue factor-bearing microparticles in the pathophysiology of various thrombotic disorders.From a personal perspective, my PhD project has been a fascinating scientific odyssey into the largely unexplored interfaces between primary and secondary hemostasis. Looking forward, my ambition is to continue our work exploring platelet-coagulation interactions and to translate these insights into clinically meaningful information, which may someday improve the treatment of patients with bleeding and/or thrombosis.
  •  
41.
  • Boknäs, Niklas, et al. (författare)
  • Thrombin-induced platelet activation via PAR4 : pivotal role for exosite II
  • 2014
  • Ingår i: Thrombosis and Haemostasis. - Stuttgart, Germany : Schattauer Gmbh. - 0340-6245 .- 2567-689X. ; 112:3, s. 558-565
  • Tidskriftsartikel (refereegranskat)abstract
    • Thrombin-induced platelet activation via PAR1 and PAR4 is an important event in haemostasis. Although the underlying mechanisms responsible for ensuring efficient PAR1 activation by thrombin have been extensively studied, the potential involvement of recognitions sites outside the active site of the protease in thrombin-induced PAR4 activation is largely unknown. In this study, we developed a new assay to assess the importance of exosite I and II for PAR4 activation with alpha- and gamma-thrombin. Surprisingly, we found that exosite II is critical for activation of PAR4. We also show that this dependency on exosite II likely represents a new mechanism, as it is unaffected by blockage of the previously known interaction between thrombin and glycoprotein Ib alpha.
  •  
42.
  • Brown, Rosemary, 1990, et al. (författare)
  • Unraveling the Surface Chemistry and Structure in Highly Active Sputtered Pt3Y Catalyst Films for the Oxygen Reduction Reaction
  • 2020
  • Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 12:4, s. 4454-4462
  • Tidskriftsartikel (refereegranskat)abstract
    • Platinum is the most widely used and best performing sole element for catalyzing the oxygen reduction reaction (ORR) in low-temperature fuel cells. Although recyclable, there is a need to reduce the amount used in current fuel cells for their extensive uptake in society. Alloying platinum with rare-earth elements such as yttrium can provide an increase in activity of more than seven times, reducing the amount of platinum and the total amount of catalyst material required for the ORR. As yttrium is easily oxidized, exposure of the Pt-Y catalyst layer to air causes the formation of an oxide layer that can be removed during acid treatment, leaving behind a highly active pure platinum overlayer. This paper presents an investigation of the overlayer composition and quality of Pt3Y films sputtered from an alloy target. The Pt3Y catalyst surface is investigated using synchrotron radiation X-ray photoelectron spectroscopy before and after acid treatment. A new substoichiometric oxide component is identified. The oxide layer extends into the alloy surface, and although it is not completely removed with acid treatment, the catalyst still achieves the expected high ORR activity. Other surface-sensitive techniques show that the sputtered films are smooth and bulk X-ray diffraction reveals many defects and high microstrain. Nevertheless, sputtered Pt3Y exhibits a very high activity regardless of the film's oxide content and imperfections, highlighting Pt3Y as a promising catalyst. The obtained results will help to support its integration into fuel cell systems.
  •  
43.
  • Burkill, Sarah, et al. (författare)
  • The DQB1* 03:02 Genotype and Treatment for Pain in People With and Without Multiple Sclerosis
  • 2020
  • Ingår i: Frontiers in Neurology. - : Frontiers. - 1664-2295. ; 11
  • Tidskriftsartikel (refereegranskat)abstract
    • Murine models have demonstrated that the major histocompatibility complex (MHC) is associated with pain-like behavior in peripheral nerve injury, however, the same association has not been shown when considering injury to the central nervous system (CNS), which more closely mimics the damage to the CNS experienced by MS patients. Previous research has indicated the DQB1*03:02 allele of the class II HLA genes as being associated with development of neuropathic pain in persons undergoing inguinal hernia surgery or with lumbar spinal disk herniation. Whether this HLA allele plays a part in susceptibility to pain, has not, as far as we are aware, been previously investigated. This study utilizes information on DQB1*03:02 alleles as part of the EIMS, GEMS, and IMSE studies in Sweden. It also uses register data for 3,877 MS patients, and 4,548 matched comparators without MS, to assess whether the DQB1*03:02 allele is associated with prescribed pain medication use, and whether associations with this genotype differ depending on MS status. Our results showed no association between the DQB1*03:02 genotype and pain medication in MS patients, with an adjusted odds ratio (OR) of 1.02 (95% CI 0.85-1.24). In contrast, there was a statistically significant association of low magnitude in individuals without MS [adjusted OR 1.18 (95% CI 1.03-1.35)], which provides support for HLA influence on susceptibility to pain in the general population. Additionally, the effect of zygosity was evident for the non-MS cohort, but not among MS patients, suggesting the DQB1*03:02 allele effect is modified by the presence of MS.
  •  
44.
  • Chaireti, Roza, et al. (författare)
  • Endogenous thrombin potential is higher during the luteal phase than during the follicular phase of a normal menstrual cycle
  • 2013
  • Ingår i: Human Reproduction. - : Oxford University Press (OUP): Policy B1 - Oxford Open Option B. - 0268-1161 .- 1460-2350. ; 28:7, s. 1846-1852
  • Tidskriftsartikel (refereegranskat)abstract
    • Do thrombin generation and haemostatic parameters differ during the two phases of the menstrual cycle? less thanbrgreater than less thanbrgreater thanTotal thrombin concentration is higher during the luteal phase compared with the follicular phase of the menstrual cycle. less thanbrgreater than less thanbrgreater thanThe coagulation cascade is affected by many variables, such as fluctuations in the levels of sex hormones. The studies on the variations in haemostatic parameters during the menstrual cycle have produced diverse results. less thanbrgreater than less thanbrgreater thanThrombin generation and selected haemostatic parameters (fibrinogen, factor II, factor VII, factor VIII, factor X, von Willebrand factor, antithrombin and D-dimer) were measured during the two phases of a normal menstrual cycle in 102 healthy women not taking any form of hormone medication. less thanbrgreater than less thanbrgreater thanThe study cohort consisted of 102 healthy women with regular menstrual cycles. Thrombin generation was measured by the calibrated automated thrombogram method. Progesterone and sex hormone-binding globulin were measured by chemiluminescence enzyme immunoassays. Estradiol was measured by a sensitive radioimmunoassay. Fibrinogen was measured by a clotting method, antithrombin was measured by a chromogenic method and factor II, factor VII, factor VIII, factor X, von Willebrand factor and D-dimer were measured by photometric methods. less thanbrgreater than less thanbrgreater thanIt was shown that the total amount of generated thrombin (Endogenous Thrombin Potential) was significantly higher during the luteal compared with the follicular phase (P 0.027). Factor X was significantly higher during the follicular phase (P 0.028). Progesterone exhibited significant associations (measured by the least squares regression analysis) with fibrinogen and factor X during the follicular phase (P 0.043 and P 0.033, respectively) and with factors II and VII during the luteal phase (P 0.034 and P 0.024, respectively). The validity of the results from the regression analysis was further confirmed by performing correlation analyses (Pearson correlation matrix) for haemostatic markers for the luteal and follicular phases (accepted correlation level 0.8). less thanbrgreater than less thanbrgreater thanThe wide confidence interval for the differences in endogenous thrombin potential during the two phases could imply that the size of the cohort may not be sufficient to fully evaluate the biological variations. Additionally, the haemostatic markers were not shown to have significant associations with thrombin generation, suggesting that the increased thrombin concentration during the luteal phase would be mediated by another mechanism, as yet unidentified. less thanbrgreater than less thanbrgreater thanThe associations between progesterone and the haemostatic markers, as shown for both phases of the menstrual cycle, suggest a previously unknown or undefined yet potentially significant role for progesterone in the coagulation system. However, it has been shown that the use of progestogen-only preparations does not affect the coagulation system, which is partly the reason why they are considered safe for women with thrombophilia or previous thrombotic event. Further studies are required in order to demonstrate whether our results can be extrapolated for synthetic progestins, which might have significant implication on the indications for their use. less thanbrgreater than less thanbrgreater thanThis study was supported by the Karolinska Institutet, Linkping University and the County Council of stergtland. The authors report no conflicts of interest.
  •  
45.
  • Chaireti, Roza, et al. (författare)
  • Increased thrombin generation in splanchnic vein thrombosis is related to the presence of liver cirrhosis and not to the thrombotic event
  • 2014
  • Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 134:2, s. 455-461
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: In recent years there have been increasing evidence associating liver disease with hypercoagulability, rather than bleeding.Aims: To evaluate the haemostatic potential in patients with liver disease.Methods: We measured thrombin generation in the presence and absence of thrombomodulin in patients with portal vein thrombosis (PVT, n=47), Budd-Chiari syndrome (BCS, n=15) and cirrhosis (n=24) and compared the results to those obtained from healthy controls (n=21). Fifteen patients with PVT and 10 patients with BCS were treated with warfarin and were compared with an equal number of patients with atrial fibrillation matched for prothrombin time-international normalized ratio. We assessed resistance to thrombomodulin by using ratios [marker measured in the presence]/[marker measured in the absence of thrombomodulin].Results: There were no differences between patients with BCS, patients on warfarin treatment and controls. Cirrhotic patients generated more thrombin in the presence of thrombomodulin and exhibited thrombomodulin resistance compared with controls [p=0.006 for endogenous thrombin potential (ETP) and p<0.001 for peak thrombin. P<0.001 for both ratios ETP and peak] and patients with non-cirrhotic PVT (p=0.001, p=0.006, p<0.001, p<0.001 for ETP, peak, ratio ETP, ratio peak). The patients with cirrhotic PVT exhibited higher ETP (p=0.044) and peak (p=0.02) in the presence of thrombomodulin than controls, as well as thrombomodulin resistance (ETP ratio: p=0.001, peak ratio: p=0.001).Conclusions: Hypercoagulability and thrombomodulin resistance in patients with cirrhosis were independent of the presence of splanchnic vein thrombosis. The hypercoagulability in patients with cirrhotic PVT could have implications for considering longer treatment with anticoagulants in this group.
  •  
46.
  • Chaireti, Roza, et al. (författare)
  • Inflammatory and endothelial markers during the menstrual cycle
  • 2016
  • Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : TAYLOR & FRANCIS LTD. - 0036-5513 .- 1502-7686. ; 76:3, s. 190-194
  • Tidskriftsartikel (refereegranskat)abstract
    • Background The menstrual cycle exhibits a pattern of repeated inflammatory activity. The present study aims to evaluate inflammatory and endothelial markers during the two phases of a menstrual cycle. Methods The study cohort consisted of 102 women with regular menstrual cycles. Inflammatory and endothelial markers (interleukin-6 [IL-6], pentraxin-3 [PTX-3], hs-C reactive protein [hs-CRP], sE-selectin, sP-selectin, intracellular and vascular cell adhesion molecules [ICAM-1 and VCAM-1] and cathepsins L, B and S) were measured during the early follicular and the late luteal phase of a normal menstrual cycle. Results Pentraxin-3 (PTX-3) and hs-CRP were significantly higher during the follicular phase compared to the luteal phase (p < 0.001 respectively p = 0.025). The other inflammatory and endothelial markers, with the exception of cathepsin B, were higher, albeit not significantly, during the follicular phase. Conclusions Inflammatory activity, expressed mainly by members of the pentraxin family, is higher during the early follicular compared to the luteal phase. This could be associated to menstruation but the exact mechanisms behind this pattern are unclear and might involve the ovarian hormones or an effect on hepatocytes.
  •  
47.
  • Chaireti, Roza, et al. (författare)
  • Is thrombin generation at the time of an acute thromboembolic episode a predictor of recurrence? The LInkoping Study on Thrombosis (LIST) - A 7-year follow-up
  • 2013
  • Ingår i: Thrombosis Research. - : Elsevier. - 0049-3848 .- 1879-2472. ; 131:2, s. 135-139
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Venous thromboembolism(VTE) is considered a chronic disease, since a high percentage of patients experience recurrences. Oral anticoagulants are effective in preventing recurrences at a price of potential bleeding complications, which underlines the importance of finding reliable markers for estimating the individual recurrence risk. In this report we evaluate thrombin generation markers at the time of an acute VTE as predictive markers for recurrence risk. Gender, presence of factor V Leiden and acquired provocative factors were taken into consideration. Additionally, we study the correlation between thrombin generation at the time of an acute VTE and thrombin generation measured four to eight weeks after discontinuation of anticoagulants. less thanbrgreater than less thanbrgreater thanMaterials and Methods: Themain cohort consisted of 115 patients with a confirmed thromboembolic event at inclusion. The follow-up period was seven years. less thanbrgreater than less thanbrgreater thanResults: Patients with an initial unprovoked VTE and at least one recurrence had significantly prolonged thrombin generation, whereas those without recurrences had higher maximum and total thrombin concentration. In contrast, when thrombin generation was measured one to two months after discontinuation of anticoagulant treatment, it was shown that the patients who experienced recurrences had higher maximum thrombin concentration. less thanbrgreater than less thanbrgreater thanConclusions: Our study shows that thrombin generation profiles at the time of a VTE correlate to the clinical course after the acute episode. The great over-lap in thrombin generation between patients with and without recurrences though, makes the use of thrombin generation profiles for advice on length of oral anticoagulation for an individual patient doubtful at the present stage of knowledge.
  •  
48.
  • Chaireti, Roza, et al. (författare)
  • Thrombin generation and D-dimer concentrations in a patient cohort investigated for venous thromboembolism. Relations to venous thrombosis, factor V Leiden and prothrombin G20210A. The LIST study.
  • 2009
  • Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 124:2, s. 178-84
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: The present study evaluated possible relations between various markers of thrombin generation, D-dimer and venous thromboembolism in outpatients with and without the FV Leiden and the protrombin mutations. PATIENTS AND METHODS: Our cohort consisted of 98 patients with the FV Leiden and 15 with the prothrombin mutation and an equal number of age- and gender-matched controls. All subjects were investigated due to suspicion of venous thromboembolism and the diagnosis was objectively confirmed or refuted. RESULTS: We compared the D-dimer values and the thrombin generation markers among different patient groups (with/without thromboembolism, with/without genetic factors, gender-linked). The only statistically significant difference noted was prolonged time both for the initiation and termination of thrombin generation in patients with thrombosis. This applied to controls and to patients heterozygous for the FV Leiden. Additionally, the D-dimer values were elevated in patients with the FV Leiden. No difference was found among the patients with prothrombin mutation and their controls. DISCUSSION: Multi-variant analysis indicated that the difference in D-dimer between FV Leiden patients and controls was due to the greater number of patients with confirmed thrombosis in the former group, a finding supported by an independent prospective study on postoperative thrombosis. Neither D-dimer concentration nor thrombin generation depend on FV Leiden. The total amount of thrombin generated was not related to diagnosis. The prolonged thrombin generation noted in controls and FV Leiden heterozygotes with thrombosis may point out different thrombin generation profiles in different patient populations and requires further studies.
  •  
49.
  • Chaireti, Roza, et al. (författare)
  • Thrombin generation and levels of factor VII activity measured in the presence of rabbit and human thromboplastins in patients with mild factor VII deficiency – effects of mutations in factor VII
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Background/Aim: It is known that spontaneous prolonged prothrombin time-international normalized ratio may be caused by deficiency of factor VII (FVII). The activity of FVII in the presence of thromboplastins of different origin is affected by the presence of specific mutations in the F7 gene. The present study aims to evaluate patients with mild FVII deficiency and somewhat discrepant FVII activity depending on the use of human or rabbit thromboplastin in relation to mutations in the FVII gene and markers of thrombin generation.Patients and methods: A cohort of 10 patients with mild deficiency of FVII and discrepant FVII activity was investigated. The median ratio of the FVII activity in the presence of human/rabbit thromboplastin was 1.4. All but 1 patient had mild to no bleeding symptoms. A genetic analysis of the F7 gene was performed. Thrombin generation was measured by the calibrated automated thrombogram in platelet poor plasma in the presence of human recombinant and different dilutions of rabbit thromboplastin and compared with thrombin generation in healthy controls (n=12). Thrombin generation was measured in 9 patients as 1 was treated with warfarin at the time of the blood sampling.Results: Six previously described mutations were found. Two of those (FVII Padua and FVII Shinjo) are known to affect the results for FVII activity dependent on the species origin of the thromboplastin. Nine out of 10 patients had one mutation in common (Arg353Gln), which however does not affect the binding site of FVII to tissue factor. Lagtime and ttpeak increased with decreasing concentrations of thromboplastin and total and maximum thrombin concentrations increased with increasing thromboplastin concentrations in the patients with FVII deficiency. ETP in patients with FVII deficiency was 86% of ETP in controls.Discussion: The Arg353Gln mutation was very common, however it does not appear to affect the reactivity towards thromboplastins of different origins. Although ETP was higher in the healthy controls, thrombin generation in FVII deficient patients was enough to sustain normal haemostasis. The expected thrombin generation patterns with increasing thromboplastin concentrations were confirmed for the patients in this study.
  •  
50.
  • Chaireti, Roza, 1979- (författare)
  • Thrombin generation in different cohorts : Evaluation of the haemostatic potential
  • 2013
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The aim of this thesis is to evaluate thrombin generation in patients with thrombophilia (Paper I), in patients with venous thromboembolism (Paper II), in healthy women during the menstrual cycle (Paper III), in patients with liver disease (Paper IV) and in patients with mild deficiency of factor VII (Paper V).For this purpose, thrombin generation was measured in platelet poor plasma by the calibrated automated thrombogram (CAT®) assay. Thrombin generation expresses the overall haemostatic potential, in contrast to the more traditional coagulation tests, which concentrate on individual factors or coagulation pathways. The thrombin generation markers that were measured and studied were: lagtime (clotting time), endogenous thrombin potential (ETP, total thrombin concentration), peak (maximum thrombin concentration) and time to peak (ttpeak).The cohorts for Papers I and II are part of a larger cohort (The LInköping Study on Thrombosis, LIST), which included 516 consecutive patients who presented at the Emergency Department of Linköping University Hospital, Sweden with the clinical suspicion of venous thrombosis. In Paper I thrombin generation was measured in the absence of thrombomodulin in patients with thrombophilia (factor V Leiden, n=98 and prothrombin G20210A mutation, n=15) and in an equal number of age- and gendermatched controls. The results were associated with the presence of thrombosis, as well as gender and age. It was shown that thrombin generation did not differ significantly among patients and controls. Patients with and patients without thrombophilia who had suffered a thrombosis upon inclusion had longer lagtime compared with their counterparts without thrombosis. Neither age nor gender had any effect on the results.In Paper II, thrombin generation at the time of an acute thromboembolic episode was studied as a potential early marker for recurrence during a 7-year follow-up in 115 patients with venous thrombosis upon inclusion. It was shown that patients with recurrences during follow-up had longer lagtime and ttpeak at the time of the acute thrombosis, whereas those without recurrences had higher ETP and peak. Those results were particularly evident in the group of patients with an unprovoked thrombosis upon inclusion.In Paper III, thrombin generation was measured in the follicular and luteal phase of a normal menstrual cycle in 102 healthy women not taking oral contraceptives. The results were associated with haemostatic parameters (fibrinogen, antithrombin, D-dimer, plasminogen activator inhibitor-1, factors VII, VIII, X and von Willebrand) as well as the physiological concentrations of oestradiol, progesterone, antimüllerian hormone and sex hormone-binding globulin and the number of pregnancies and deliveries for these women. ETP was significantly higher during the luteal phase. However, this could not be explained by the elevation of other procoagulant factors during the same phase. Progesterone was found to exert a more significant effect on haemostasis than oestradiol during both phases (multiple regression analysis).In Paper IV, thrombin generation was measured in the presence and absence of thrombomodulin in 47 patients with portal vein thrombosis, PVT (11 with cirrhotic PVT and 36 with non-cirrhotic PVT), 15 patients with Budd-Chiari syndrome and 24 patients with cirrhosis, as well as 21 healthy controls. Since 15 patients with PVT (2 with cirrhotic PVT and 13 with non-cirrhotic PVT) and 10 patients with Budd-Chiari syndrome were treated with warfarin at the time of the blood sampling, an equal number of patients matched for age, gender and prothrombin time-international normalized ratio with atrial fibrillation and no hepatic diseases were used as controls. It was shown that hypercoagulability, expressed as total and maximum concentration of generated thrombin as well as thrombomodulin resistance [thrombin generation markers measured in the presence]/[thrombin generation markers measured in the absence of thrombomodulin] was pronounced in the groups of patients with cirrhosis, regardless of the presence of splanchnic thrombosis.In Paper V, thrombin generation in the presence of human and different concentrations of rabbit thromboplastin was measured in 10 patients with mild deficiency of factor VII and in 12 controls. In these patients, the levels of factor VII varied slightly depending on the origin of the thromboplastin used in the reagent. Nine out of 10 patients had a mutation in common (Arg353Gln), which was, however, not associated with the diversity in the factor VII measurements due to the origin of thromboplastin. ETP in patients with mild factor VII deficiency was about 86% of the ETP in the control group. The expected thrombin generation patterns with increasing concentrations of thromboplastin did not differ depending on the origin of thromboplastin in the patient group.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 362
Typ av publikation
tidskriftsartikel (287)
konferensbidrag (34)
annan publikation (14)
doktorsavhandling (14)
forskningsöversikt (6)
rapport (4)
visa fler...
bok (1)
licentiatavhandling (1)
patent (1)
visa färre...
Typ av innehåll
refereegranskat (282)
övrigt vetenskapligt/konstnärligt (74)
populärvet., debatt m.m. (6)
Författare/redaktör
Lindahl, Tomas (104)
Jernberg, Tomas (97)
Lindahl, Bertil, 195 ... (61)
Lindahl, Tomas, 1954 ... (57)
Lindahl, Bertil (48)
Erlinge, David (37)
visa fler...
Lindahl, Tomas L (30)
Bäcklund, Tomas (25)
Faxälv, Lars (24)
Eggers, Kai M., 1962 ... (21)
Lindahl, Olof (21)
Ramström, Sofia, 197 ... (20)
Tengvall, Pentti (16)
Wallentin, Lars (16)
Baron, Tomasz (16)
Venge, Per (15)
Hillarp, Andreas (15)
Alfredsson, Joakim (14)
Larsson, Anders (13)
Ramström, Sofia (13)
Boknäs, Niklas (12)
Rånby, Mats (12)
James, Stefan (11)
Bjerner, Tomas (11)
Ahlström, Håkan (10)
James, Stefan, 1964- (10)
Stridsberg, Mats (10)
Szummer, Karolina (10)
Spaak, Jonas (10)
Lindahl, Tomas, Prof ... (10)
Hofmann, Robin (9)
Kellerth, Thomas (9)
Fagerberg, Inger (9)
Eklund, Anders (8)
Osman, Abdimajid (8)
Nordenskjöld, Anna M ... (8)
Hadziosmanovic, Nerm ... (8)
Duvernoy, Olov (8)
Hansson, Kenny, 1972 ... (8)
Järemo, Petter (8)
Fröbert, Ole, 1964- (7)
Lundström, Ingemar (7)
Lagerqvist, Bo (7)
Östlund, Ollie (7)
Chaireti, Roza (7)
Milovanovic, Micha, ... (7)
Tynngård, Nahreen (7)
Eggers, Kai M (7)
Ljung, Lina (7)
Nylander, Martina (7)
visa färre...
Lärosäte
Linköpings universitet (210)
Uppsala universitet (127)
Karolinska Institutet (89)
Lunds universitet (50)
Örebro universitet (36)
Göteborgs universitet (26)
visa fler...
Luleå tekniska universitet (24)
Umeå universitet (18)
Högskolan i Borås (6)
Chalmers tekniska högskola (5)
Stockholms universitet (4)
RISE (4)
Kungliga Tekniska Högskolan (3)
Linnéuniversitetet (3)
Sveriges Lantbruksuniversitet (3)
Högskolan Kristianstad (1)
Södertörns högskola (1)
Kungl. Konsthögskolan (1)
visa färre...
Språk
Engelska (342)
Svenska (18)
Odefinierat språk (2)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (169)
Teknik (33)
Naturvetenskap (22)
Lantbruksvetenskap (1)
Humaniora (1)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy