| 1. |
- Hillarp, Andreas, et al.
(författare)
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Effects of the oral, direct factor Xa inhibitor rivaroxaban on commonly used coagulation assays
- 2011
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Ingår i: JOURNAL OF THROMBOSIS AND HAEMOSTASIS. - : Blackwell Publishing. - 1538-7933 .- 1538-7836. ; 9:1, s. 133-139
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Rivaroxaban is an oral direct factor Xa inhibitor developed for prophylaxis and treatment of thromboembolic disorders. Laboratory monitoring is not necessary but the dose-dependent effects on common reagents and assay procedures are largely unknown. Objectives: To investigate the effect of rivaroxaban on commonly used coagulation assays. Materials and Methods: Rivaroxaban was added to plasma from healthy subjects in the concentration range 0-1000 mu g L-1 and analyzed using different reagents for activated partial thromboplastin time (APTT), prothrombin time (PT), antithrombin, fibrinogen and activated protein C (APC) resistance assays. Results: At an expected peak concentration of rivaroxaban in clinical use, the APTTs were almost invariably prolonged but at lower concentrations the effect was weak. The concentration needed to double the APTT varied between 389 +/- 106 and 617 +/- 149 mu g L-1 for different reagents. The PT assays showed a marked degree of difference. In general, the Quick PT type assays were more sensitive compared with the Owren type PT assays. The results from antithrombin assays were dependent on the type of reagent, with the Xa-based assay being sensitive for rivaroxaban with an estimated increase of 0.09 IU mL-1 per 100 mu g L-1 rivaroxaban. There were only minor effects on fibrinogen assays based on thrombin reagents. The APTT-based assay for APC resistance is affected in a dose-dependent manner whereas an assay based on the activation of coagulation at the prothrombinase level was unaffected. Conclusions: Different assays, and even different reagents within an assay group, display variable effects by therapeutic concentrations of rivaroxaban.
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| 2. |
- Isfahani, S. M. M., et al.
(författare)
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An ultra-low power multi-tunable triangle wave generator with frequency and amplitude control
- 2010
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Ingår i: ; , s. 236-239
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Konferensbidrag (refereegranskat)abstract
- ultra-low power adjustable triangle wave generator with a multi tunable amplitude and frequency is introduced in this paper. The proposed circuit consists of a Schmitt trigger and a current source. The overall nonlinearity of the TWG circuit is less than 2% in its current-to-frequency transfer characteristic. The tunable frequency and amplitude range are 10KHz to 40KHz and 0.1V-1.7V respectively. The topology is suitable for VLSI realization and can be used in the WINeR system.
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| 3. |
- Kazerouni, I. A., et al.
(författare)
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A 77 nW bioamplifier with a tunable bandwidth for neural recording systems
- 2010
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Ingår i: IEEE Asia-Pacific Conference on Circuits and Systems, Proceedings, APCCAS. - 9781424474561 ; , s. 36-39
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Konferensbidrag (refereegranskat)abstract
- In this paper a low-power low-noise amplifier for neural recording and biomedical applications is presented. The frequency band of the amplifier is tunable. It has a gain of 28.3 dB. The low and the high cut-off frequency can be adjusted from 24 mHz to 30.6 Hz and 4.5 kHz to 7.47 kHz, respectively. The circuit is designed in 0.18μm CMOS process, and it consumes only 77.8 nW at 1.8V supply voltage. The simulation results show a 14.3μV input-referred noise corresponding to 1.32 efficiency factor (NEF). It is a great improvement compared with recent presented works in terms on power consumption and NEF which is vital in neural recording applications.
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| 4. |
- Lövdahl, Susanna, et al.
(författare)
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A longitudinal study of family structure in Swedish persons with haemophilia
- 2014
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 20:4, s. 493-499
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Tidskriftsartikel (refereegranskat)abstract
- Haemophilia is an X-linked inherited rare bleeding disorder affecting mainly men. The treatment consists of replacement therapy that has been associated with severe side effects, such as blood transmitted viral infections, but has markedly improved over the last decades. The aim of this study was to study family structure over time among Swedish persons with haemophilia (PWH), focusing on children, siblings and marital status. PWH A or B were identified from the haemophilia centres and the national Patient Registry. Each PWH was compared to five age- and gender-matched controls. The national Multi-Generation Registry was used to identify children and siblings. A total of 1365 children with a father suffering from haemophilia A or B and 1938 siblings of the PWH were identified. Having one or more children was significantly less common (P=0.003) for PWH than for controls. Significantly lower rates of having a child were also found for the subgroups of persons suffering from severe haemophilia and those infected with HIV (P<0.001). A higher proportion of PWH, with or without HIV and/or viral hepatitis had siblings compared to the controls (P<0.001). However, the mean number of siblings was significantly lower for persons with severe haemophilia (P=0.001). The number of marriages and divorces did not differ between PWH and controls. Our data indicate a negative impact of HIV and viral hepatitis on family structure for PWH despite the relatively good access to treatment in Sweden over the last few decades. This was particularly true for those with a severe form of haemophilia.
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| 5. |
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| 6. |
- Berntorp, Erik, et al.
(författare)
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Treatment of haemophilia A and B and von Willebrand's disease : summary and conclusions of a systematic review as part of a Swedish health-technology assessment
- 2012
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 18:2, s. 158-165
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Forskningsöversikt (refereegranskat)abstract
- In an ongoing health-technology assessment of haemophilia treatment in Sweden, performed by the governmental agency Dental and Pharmaceutical Benefits Agency (TLV; tandvårds-och läkemedelsförmånsverket), the Swedish Council on Health Technology Assessment (SBU; statens beredning för medicinsk utvärdering) was called upon to evaluate treatment of haemophilia A and B and von Willebrand's disease (VWD) with clotting factor concentrates. To evaluate the following questions: What are the short-term and long-term effects of different treatment strategies? What methods are available to treat haemophilia patients that have developed inhibitors against factor concentrates? Based on the questions addressed by the project, a systematic database search was conducted in PubMed, NHSEED, Cochrane Library, EMBASE and other relevant databases. The literature search covered all studies in the field published from 1985 up to the spring of 2010. In most instances, the scientific evidence is insufficient for the questions raised in the review. Concentrates of coagulation factors have good haemostatic effects on acute bleeding and surgical intervention in haemophilia A and B and VWD, but conclusions cannot be drawn about possible differences in the effects of different dosing strategies for acute bleeding and surgery. Prophylaxis initiated at a young age can prevent future joint damage in persons with haemophilia. The available treatment options for inhibitors have been insufficiently assessed. The economic consequences of various treatment regimens have been insufficiently analysed. Introduction of national and international registries is important.
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| 7. |
- Hillarp, Andreas, et al.
(författare)
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Effects of the oral, direct factor Xa inhibitor apixaban on routine coagulation assays and anti-FXa assays
- 2014
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 12:9, s. 1545-1553
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionApixaban is an oral direct factorXa inhibitor developed for the prophylaxis and treatment of thromboembolic disorders. Laboratory monitoring is not necessary, but the effects on common coagulation reagents and assays constitute clinically valuable information. ObjectivesTo investigate the effects of apixaban on commonly used coagulation methods, and to evaluate anti-FXa assays for specific determination of the drug concentration. Materials and MethodsApixaban was added to plasma from healthy subjects in the concentration range 0-1000gL(-1), and analyses were performed with different reagents for activated partial thromboplastin time (APTT), prothrombin time (PT), antithrombin, proteinC, and proteinS. A lupus anticoagulant assay and an APTT assay with varying phospholipid concentrations were used to study the phospholipid dependence. ResultsIn general, apixaban showed fewer effects invitro than have been shown for rivaroxaban, another direct FXa inhibitor. The concentration needed to double the APTT varied between 2200 and 4700gL(-1), and the concentration needed to double the PT varied between 700 and 3900gL(-1). The effects on antithrombin, proteinC and proteinS assays were dependent on the type of reagent. Apixaban did not cause false-positive lupus anticoagulant results. Chromogenic anti-FXa assays showed linear dose-response curves with apixaban. ConclusionsTherapeutic concentrations of apixaban variably affect different assay groups, and even different reagents within an assay group. The effects were much smaller than with rivaroxaban. The use of APTT and/or PT assays to screen the anticoagulant activity of apixaban cannot be recommended. A chromogenic anti-FXa assay can be used for reliable measurements of apixaban concentration.
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| 8. |
- Kianpour, I., et al.
(författare)
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A subthreshold ultra low power 22fJ/conversion flash ADC for RFID sensing applications
- 2011
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Ingår i: 2011 19th Iranian Conference on Electrical Engineering (ICEE). - 9781457707308 - 9789644634284 ; , s. 1-4
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper an ultra low power Flash ADC for RFID application is presented. Several techniques are used to further reduce the power consumption and relatively elevate the speed of the ADC. These techniques include a low power Track-and-Latch comparator with no static current, large resisters in the resister string, an optimum encoder with only 2 stages using subthreshold design with the aid of low supply voltage of 0.7v for resister string and 0.5v for all logic blocks. In this ADC by absolute approximation the occupied area is equal with area of 16 resisters in the string. The circuit designed in 0.18μm CMOS technology and simulations show that the 4-bit ADC consumes almost 14.5μW at 40MS/s and 93.8nW at 0.1MS/s; however, it minimally dissipates only 22fJ per each conversion step. The results show that the proposed ADC could seriously compete with other low power ADCs in RFID sensing applications such as SAR ADCs.
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| 9. |
- Lindahl, Tomas, et al.
(författare)
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Effects of the oral, direct thrombin inhibitor dabigatran on five common coagulation assays
- 2011
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Ingår i: Thrombosis and Haemostasis. - : F K Schattauer Verlagsgesellschaft MBH. - 0340-6245 .- 2567-689X. ; 105:2, s. 371-378
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Tidskriftsartikel (refereegranskat)abstract
- Dabigatran is an oral, reversible thrombin inhibitor that has shown promising results in large clinical trials. Laboratory monitoring is not needed but the effects on common coagulation assays are incompletely known. Dabigatran was added to plasma from healthy subjects in the concentration range 0-1,000 μg/l and analysed using several reagents for activated thromboplastin time (APTT), prothrombin time (PT), fibrinogen, antithrombin, and activated protein C resistance. Typical trough concentrations are about 50 μg/l, peak concentrations 100-300 μg/l. At 100 μg/l all APTT-results were prolonged. The concentration required to double APTT ranged between 227 and 286 μg/l, the responses for all five reagents were similar. PT-reagents were much less affected with almost no samples above INR 1.2 at 100 μg/l. The effect was sample dilution dependent with PT Quick type more sensitive than PT Owren type methods. If a patient on dabigatran has prolonged APTT, >90 seconds, and Quick PT INR>2 or Owren PT INR>1.5 over-dosing or accumulation of dabigatran should be considered. Two of four fibrinogen reagents underestimated the fibrinogen concentration considerably at expected peak concentration. Methods based on inhibition of thrombin over-estimated the antithrombin concentration, but not Xa-based. The APC-resistance methods over-estimated the APC-ratio, which may lead to miss-classification of factor V Leiden patients as being normal. Different coagulation assays, and even different reagents within an assay group, display variable effects at therapeutic concentrations of dabigatran. Some of these assay variations are of clinical importance, thus knowledge is needed for a correct interpretation of results.
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| 10. |
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| 11. |
- Lövdahl, Susanna, et al.
(författare)
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Incidence, mortality rates and causes of deaths in haemophilia patients in Sweden.
- 2013
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Ingår i: Haemophilia. - : Wiley. - 1351-8216. ; 19:3, s. 362-369
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Tidskriftsartikel (refereegranskat)abstract
- Sweden has been a pioneer in the treatment of haemophilia, with the first concentrate available in the 1950s. Treatment has improved over the years to its current state-of-the art. The aim of the current study was to evaluate the long-term outcome of haemophilia in terms of incidence, morbidity and mortality. Patients diagnosed with haemophilia A or B registered at the national haemophilia centres and/or the Patient Registry and born before 2009 and alive in 1968 were enrolled and linked to the Cause of Death-, Migration- and Medical Birth registries. Five age- and sex-matched controls were selected for each patient. A total of 1431 patients with haemophilia A or B were compared with 7150 controls. The 3-year moving average incidence rate per 100 000 population varied between 21 and 36. The hazard ratio for all-cause mortality compared with controls was 2.2, 95% CI: [1.8; 2.7], P < 0.001 for the entire group of patients and 1.7, 95% CI: [1.3; 2.2], P < 0.001 when patients with HIV and/or viral hepatitis were excluded. The corresponding figures for the severe haemophilia subgroup were 6.6, 95% CI: [4.5; 10.0], P < 0.001 and 8.2, 95% CI [3.2; 20.8], P < 0.001 respectively. The most common causes of death were related to malignancies and the haemostatic defect. People with haemophilia were 57% less likely to die from ischaemic heart disease than controls. People with haemophilia in Sweden demonstrate higher mortality over time, independent of HIV and viral hepatitis, despite relatively advantageous access to clotting factor concentrates.
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| 12. |
- Nilsaz, A. S., et al.
(författare)
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Low power 0.18 um CMOS ultra wideband inductor-less LNA design for UWB receiver
- 2010
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Ingår i: IEEE Asia-Pacific Conference on Circuits and Systems, Proceedings, APCCAS. - 9781424474561 ; , s. 855-858
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Konferensbidrag (refereegranskat)abstract
- This paper presents an inductor-less low-noise amplifier (LNA) design for ultra-wideband (UWB) receivers and microwave access covering the frequency range from 0.4 to 5.7 GHz using 0.18-μm CMOS. Simulation results show that the voltage gain reaches a peak of 18.94 dB in-band with an upper 3-dB frequency of 5.7 GHz. The IIP3 is about 3 dBm and the noise figure (NF) ranges from 3.15-3.86 dB over the band of interest. Input matching is better than -8.79dB and the LNA consumes 5.77mW at 1.8V supply voltage. A figure of merit is used to compare the proposed design with recently published wideband CMOS LNAs. The proposed design achieves a superior voltage gain and tolerable NF, with the additional advantage of removing the bulky inductors. It is shown that the designed LNA without on-chip inductors achieves comparable performances with inductor-based designs.
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| 13. |
- Radulovic, Vladimir, 1969, et al.
(författare)
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Sustained heparin effect contributes to reduced plasma thrombin generation capacity early after cardiac surgery.
- 2012
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Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 130:5, s. 769-774
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Thrombin is a key component in the coagulation cascade, and impaired thrombin generation has been linked to increased bleeding after surgical procedures. The aim was to evaluate postoperative thrombin generation capacity in plasma after cardiac surgery, and its potential associations to activity of individual coagulation factors and heparin. MATERIAL AND METHODS: Forty-eight coronary artery bypass grafting patients were included in a prospective observational cohort study. Thrombin generation capacity was analysed in plasma with calibrated automated thrombogram with tissue factor as activator before (baseline), and 2h and 24h after surgery. In addition, plasma activity of coagulation factors II, V, VII, VIII, IX, X, XI, XIII, were determined. Heparin effect was assessed by anti-Xa activity, APTT and thrombin time. RESULTS: Thrombin generation was markedly reduced 2h after surgery compared to baseline. Peak levels decreased with median 74% (interquartile range 52-90), p<0.001, and endogenous thrombin generation potential decreased with 65% (43-86), p<0.001. Postoperative changes in endogenous thrombin generation potential correlated inversely to changes in anti-Xa activity (r=-0.51, p=0.010) and to changes in thrombin time (r=-0.51, p=0.009), but there were no correlations to changes in individual coagulation factor activity. CONCLUSIONS: A marked reduction in thrombin generation potential was observed in the early postoperative phase after cardiac surgery. The decrease was independent of reductions in individual coagulation factor activity but correlated to heparin effects. The results indicate that a sustained heparin effect contributes to the postoperative reduction in thrombin generation capacity.
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| 14. |
- Sarmiento M., David, et al.
(författare)
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A 9.2pJ/pulse UWB-IR transmitter with tunable amplitude for wireless sensor tags in 0.18um CMOS
- 2010
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Konferensbidrag (refereegranskat)abstract
- This paper presents a transmitter design for Ultra Wideband Impulse Radio (UWB-IR) communications. The design is targeted towards the implementation of passive Wireless Sensor Tags (WST) where micro-power consumption is required. The transmitter has been implemented in UMC 0.18μm CMOS and placed inside a QFN lead-less package. It complies with the FCC regulations for Pulse Rate Frequencies (PRF) up to 10MHz using OOK modulation. It is capable of adjusting the Power Spectral Emissions (PSE) modifying the transmitted pulse amplitude to always achieve the best BER/Power performance depending on the application demands. The power emission tunability has been validated implementing a complete communication link using a low sensitivity non-coherent energy receiver. Measurements show a maximum power consumption of 92uW@10MHz PRF having a maximum energy/pulse of 9.2 pJ.
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| 15. |
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| 16. |
- Ternström, Lisa, 1972, et al.
(författare)
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Plasma activity of individual coagulation factors, hemodilution and blood loss after cardiac surgery: a prospective observational study.
- 2010
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Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 126:2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hemodilution and consumption of coagulation factors during cardiopulmonary bypass has been suggested to contribute to bleeding complications after cardiac surgery. The aim was to describe the activity of individual coagulation factors after CABG in relation to hemodilution and postoperative bleeding. MATERIALS AND METHODS: Plasma concentrations of fibrinogen and plasma activity of FII, FV, FVII, FVIII, FIX, FX, FXI and FXIII adjusted for hemodilution were analysed in 57 CABG patients before, and 2h and 24h after surgery. Postoperative bleeding was registered and correlations to coagulation factor activity were calculated. RESULTS: Adjusted plasma concentration of fibrinogen (-14+/-6%), and plasma activity of FII (-9+/-6%), FV (-13+/-8%), FX (-13+/-7%) and FXIII (-9+/-14%) were reduced two hours after surgery compared to baseline (all p<0.001). FVII (+3+/-12%, p=0.34) and FXI (+1+/-19%, p=0.50) were unchanged, while FVIII (+23+/-44%, p=0.006) and FIX (+23+/-17%, p<0.001) increased. Twenty-four hours after surgery fibrinogen (+45+/-27%), FVIII (+93+/-66%) and FIX (+33+/-26%) were all increased (all p<0.001), while FVII (-37+/-14%, p<0.001), FXI (-4+/-18%, p=0.02) and FXIII (-6+/-15%, p=0.004) were decreased. Median postoperative blood loss was 380 ml/12h. There were significant inverse correlations between postoperative blood loss and fibrinogen concentration 2h after surgery (r=-0.33, p=0.019) and between postoperative blood loss and pre- and postoperative FXIII activity (r=-0.34, p=0.009 and r=-0.41, p=0.003, respectively), but not between blood loss and any of the other factors. CONCLUSIONS: There is a marked dissociation in plasma activity of individual coagulation factors after CABG. Plasma concentration of fibrinogen and factor XIII activity correlates inversely to postoperative blood loss after CABG.
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