| 1. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 2. |
- Sardiwal, Sunita, et al.
(författare)
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Bone Alkaline Phosphatase in CKD-Mineral Bone Disorder
- 2013
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Ingår i: American Journal of Kidney Diseases. - : Elsevier. - 0272-6386 .- 1523-6838. ; 62:4, s. 810-822
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Forskningsöversikt (refereegranskat)abstract
- Overall and cardiovascular mortality in patients with chronic kidney disease (CKD) is greatly increased, without obvious current effective treatments. Mineral and bone disorder (MBD) is a common manifestation of CKD and contributes to the high risk of fracture and cardiovascular mortality in these patients. Traditionally, clinical management of CKD-MBD focused on attenuation of secondary hyperparathyroidism due to impaired renal activation of vitamin D and phosphate retention, although recently, adynamic forms of renal bone disease have become more prevalent. Definitive diagnosis was based on histologic (histomorphometric) analysis of bone biopsy material supported by radiologic changes and changes in levels of surrogate laboratory markers. Of these various markers, parathyroid hormone (PTH) has been considered to be the most sensitive and currently is the most frequently used; however, the many pitfalls of measuring PTH in patients with CKD increasingly are appreciated. We propose an alternative or complementary approach using bone alkaline phosphatase (ALP), which is directly related to bone turnover, reflects bone histomorphometry, and predicts outcomes in hemodialysis patients. Here, we consider the overall merits of bone ALP as a marker of bone turnover in adults with CKD-MBD, examine published bone histomorphometric data comparing bone ALP to PTH, and discuss possible pathogenic mechanisms by which bone ALP may be linked to outcomes in patients with CKD.
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| 3. |
- Björk, Jonas, et al.
(författare)
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GFR estimation based on standardized creatinine and cystatin C : A European multicenter analysis in older adults
- 2018
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1437-4331 .- 1434-6621. ; 56:3, s. 422-435
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Tidskriftsartikel (refereegranskat)abstract
- Although recommended by the Kidney Disease Improving Global Outcomes, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPICR) creatinine equation was not targeted to estimate glomerular filtration rate (eGFR) among older adults. The Berlin Initiative Study (BIS1CR) equation was specifically developed in older adults, and the Lund-Malmö revised (LMRCR) and the Full Age Spectrum (FASCR) equations have shown promising results in older adults. Our aim was to validate these four creatinine equations, including addition of cystatin C in a large multicenter cohort of Europeans ≥70 years. A total of 3226 individuals (2638 with cystatin C) underwent GFR measurement (mGFR; median, 44 mL/min/1.73 m2) using plasma iohexol clearance. Bias, precision (interquartile range [IQR]), accuracy (percent of estimates ±30% of mGFR, P30), eGFR accuracy diagrams and probability diagrams to classify mGFR<45 mL/min/1.73 m2 were compared. The overall results of BIS1CR/CKD-EPICR/FASCR/LMRCR were as follows: median bias, 1.7/3.6/0.6/-0.7 mL/min/1.73 m2; IQR, 11.6/12.3/11.1/10.5 mL/min/1.73 m2; and P30, 77.5%/76.4%/80.9%/83.5% (significantly higher for LMR, p<0.001). Substandard P30 (<75%) was noted for all equations at mGFR<30 mL/min/1.73 m2, and at body mass index values <20 and ≥35 kg/m2. LMRCR had the most stable performance across mGFR subgroups. Only LMRCR and FASCR had a relatively constant small bias across eGFR levels. Probability diagrams exhibited wide eGFR intervals for all equations where mGFR<45 could not be confidently ruled in or out. Adding cystatin C improved P30 accuracy to 85.7/86.8/85.7/88.7 for BIS2CR+CYS/CKD-EPICR+CYS/FASCR+CYS/MEANLMR+CAPA. LMRCR and FASCR seem to be attractive alternatives to CKD-EPICR in estimating GFR by creatinine-based equations in older Europeans. Addition of cystatin C leads to important improvement in estimation performance.
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| 4. |
- Björk, Jonas, et al.
(författare)
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Prospects for improved glomerular filtration rate estimation based on creatinine—results from a transnational multicentre study
- 2020
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Ingår i: Clinical Kidney Journal. - : Oxford University Press (OUP). - 2048-8505 .- 2048-8513. ; 13:4, s. 674-683
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Tidskriftsartikel (refereegranskat)abstract
- Background The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation is routinely used to assess renal function but exhibits varying accuracy depending on patient characteristics and clinical presentation. The overall aim of the present study was to assess if and to what extent glomerular filtration rate (GFR) estimation based on creatinine can be improved.MethodsIn a cross-sectional analysis covering the years 2003–17, CKD-EPI was validated against measured GFR (mGFR; using various tracer methods) in patients with high likelihood of chronic kidney disease (CKD; five CKD cohorts, n = 8365) and in patients with low likelihood of CKD (six community cohorts, n = 6759). Comparisons were made with the Lund–Malmö revised equation (LMR) and the Full Age Spectrum equation.Results7In patients aged 18–39 years old, CKD-EPI overestimated GFR with 5.0–16 mL/min/1.73 m2 in median in both cohort types at mGFR levels <120 mL/min/1.73 m2. LMR had greater accuracy than CKD-EPI in the CKD cohorts (P30, the percentage of estimated GFR within 30% of mGFR, 83.5% versus 76.6%). CKD-EPI was generally the most accurate equation in the community cohorts, but all three equations reached P30 above the Kidney Disease Outcomes Quality Initiative benchmark of 90%.ConclusionsNone of the evaluated equations made optimal use of available data. Prospects for improved GFR estimation procedures based on creatinine exist, particularly in young adults and in settings where patients with suspected or manifest CKD are investigated.
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| 5. |
- Delanaye, Pierre, et al.
(författare)
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Performance of creatinine-based equations to estimate glomerular filtration rate with a methodology adapted to the context of drug dosage adjustment
- 2022
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Ingår i: British Journal of Clinical Pharmacology. - : Wiley-Blackwell Publishing Inc.. - 0306-5251 .- 1365-2125. ; 88:5, s. 2118-2127
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The Cockcroft-Gault (CG) creatinine-based equation is still used to estimate glomerular filtration rate (eGFR) for drug dosage adjustment. Incorrect eGFR may lead to hazardous over- or underdosing METHODS: In a cross-sectional analysis, CG was validated against measured GFR (mGFR) in 14,804 participants and compared with the Modification-of-Diet-in-Renal-Diseases (MDRD), Chronic-Kidney-Disease-Epidemiology (CKD-EPI), Lund-Malmö-Revised (LMR), and European-Kidney-Function-Consortium (EKFC) equations. Validation focused on bias, imprecision, and accuracy (percentage of estimates within ±30% of mGFR, P30), overall and stratified for mGFR, age, and body mass index at mGFR <60 mL/min, as well as classification in mGFR stages.RESULTS: The CG equation performed worse than the other equations, overall and in mGFR, age and BMI subgroups in terms of bias (systematic overestimation), imprecision and accuracy except for patients ≥65 years where bias and P30 were similar to MDRD and CKD-EPI, but worse than LMR and EKFC. In subjects with mGFR<60 mL/min and at BMI [18.5-25[kg/m2 , all equations performed similarly and for BMI<18.5kg/m2 CG and LMR had the best results though all equations had poor P30-accuracy. At BMI≥25kg/m2 the bias of the CG increased with increasing BMI (+17.2mL/min at BMI≥40kg/m2 ). The four more recent equations also classified mGFR stages better than CG.CONCLUSIONS: The CG equation showed poor ability to estimate GFR overall and in analyses stratified for GFR, age, and BMI. CG was inferior to correctly classify the patients in the mGFR staging compared to more recent creatinine-based equations.
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| 6. |
- Pottel, Hans, et al.
(författare)
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Cystatin C–Based Equation to Estimate GFR without the Inclusion of Race and Sex
- 2023
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Ingår i: The New England journal of medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 388:4, s. 333-343
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDThe accuracy of estimation of kidney function with the use of routine metabolic tests, such as measurement of the serum creatinine level, has been controversial. The European Kidney Function Consortium (EKFC) developed a creatinine-based equation (EKFC eGFRcr) to estimate the glomerular filtration rate (GFR) with a rescaled serum creatinine level (i.e., the serum creatinine level is divided by the median serum creatinine level among healthy persons to control for variation related to differences in age, sex, or race). Whether a cystatin C–based EKFC equation would increase the accuracy of estimated GFR is unknown.METHODSWe used data from patients in Sweden to estimate the rescaling factor for the cystatin C level in adults. We then replaced rescaled serum creatinine in the EKFC eGFRcr equation with rescaled cystatin C, and we validated the resulting EKFC eGFRcys equation in cohorts of White patients and Black patients in Europe, the United States, and Africa, according to measured GFR, levels of serum creatinine and cystatin C, age, and sex.RESULTSOn the basis of data from 227,643 patients in Sweden, the rescaling factor for cystatin C was estimated at 0.83 for men and women younger than 50 years of age and 0.83+0.005×(age–50) for those 50 years of age or older. The EKFC eGFRcys equation was unbiased, had accuracy that was similar to that of the EKFC eGFRcr equation in both White patients and Black patients (11,231 patients from Europe, 1093 from the United States, and 508 from Africa), and was more accurate than the Chronic Kidney Disease Epidemiology Collaboration eGFRcys equation recommended by Kidney Disease: Improving Global Outcomes. The arithmetic mean of EKFC eGFRcr and EKFC eGFRcys further improved the accuracy of estimated GFR over estimates from either biomarker equation alone.CONCLUSIONSThe EKFC eGFRcys equation had the same mathematical form as the EKFC eGFRcr equation, but it had a scaling factor for cystatin C that did not differ according to race or sex. In cohorts from Europe, the United States, and Africa, this equation improved the accuracy of GFR assessment over that of commonly used equations.
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| 7. |
- Pottel, Hans, et al.
(författare)
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Cystatin C–Based Equation to Estimate GFR without the Inclusion of Race and Sex
- 2023
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Ingår i: New England Journal of Medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 388:4, s. 333-343
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe accuracy of estimation of kidney function with the use of routine metabolic tests, such as measurement of the serum creatinine level, has been controversial. The European Kidney Function Consortium (EKFC) developed a creatinine-based equation (EKFC eGFRcr) to estimate the glomerular filtration rate (GFR) with a rescaled serum creatinine level (i.e., the serum creatinine level is divided by the median serum creatinine level among healthy persons to control for variation related to differences in age, sex, or race). Whether a cystatin C–based EKFC equation would increase the accuracy of estimated GFR is unknown.MethodsWe used data from patients in Sweden to estimate the rescaling factor for the cystatin C level in adults. We then replaced rescaled serum creatinine in the EKFC eGFRcr equation with rescaled cystatin C, and we validated the resulting EKFC eGFRcys equation in cohorts of White patients and Black patients in Europe, the United States, and Africa, according to measured GFR, levels of serum creatinine and cystatin C, age, and sex.ResultsOn the basis of data from 227,643 patients in Sweden, the rescaling factor for cystatin C was estimated at 0.83 for men and women younger than 50 years of age and 0.83+0.005×(age–50) for those 50 years of age or older. The EKFC eGFRcys equation was unbiased, had accuracy that was similar to that of the EKFC eGFRcr equation in both White patients and Black patients (11,231 patients from Europe, 1093 from the United States, and 508 from Africa), and was more accurate than the Chronic Kidney Disease Epidemiology Collaboration eGFRcys equation recommended by Kidney Disease: Improving Global Outcomes. The arithmetic mean of EKFC eGFRcr and EKFC eGFRcys further improved the accuracy of estimated GFR over estimates from either biomarker equation alone.ConclusionsThe EKFC eGFRcys equation had the same mathematical form as the EKFC eGFRcr equation, but it had a scaling factor for cystatin C that did not differ according to race or sex. In cohorts from Europe, the United States, and Africa, this equation improved the accuracy of GFR assessment over that of commonly used equations. (Funded by the Swedish Research Council.)
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| 8. |
- Pottel, Hans, et al.
(författare)
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Development and Validation of a Modified Full Age Spectrum Creatinine-Based Equation to Estimate Glomerular Filtration Rate : A Cross-sectional Analysis of Pooled Data
- 2021
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Ingår i: Annals of Internal Medicine. - : American College of Physicians. - 0003-4819 .- 1539-3704. ; 174:2, s. 183-191
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Chronic Kidney Disease in Children Study (CKiD) equation for children and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for adults are recommended serum creatinine (SCr)-based calculations for estimating glomerular filtration rate (GFR). However, these equations, as well as their combination, have limitations, notably the problem of implausible changes in GFR during the transition from adolescence to adulthood and overestimation of GFR in young adults. The full age spectrum (FAS) equation addresses these issues but overestimates GFR when SCr levels are low.OBJECTIVE: To develop and validate a modified FAS SCr-based equation combining design features of the FAS and CKD-EPI equations.DESIGN: Cross-sectional analysis with separate pooled data sets for development and validation.SETTING: = 13) with measured GFR available.PATIENTS: 11 251 participants in 7 studies (development and internal validation data sets) and 8378 participants in 6 studies (external validation data set).MEASUREMENTS: Clearance of an exogenous marker (reference method), SCr level, age, sex, and height were used to develop a new equation to estimate GFR.RESULTS: ] in adults) across the FAS (2 to 90 years) and SCr range (40 to 490 µmol/L [0.45 to 5.54 mg/dL]) and with fewer estimation errors exceeding 30% (6.5% [CI, 3.8% to 9.1%] in children and 3.1% [CI, 2.5% to 3.6%] in adults) compared with the CKiD and CKD-EPI equations.LIMITATION: No Black patients were included.CONCLUSION: The new EKFC equation shows improved accuracy and precision compared with commonly used equations for estimating GFR from SCr levels.PRIMARY FUNDING SOURCE: Swedish Research Council (Vetenskapsrådet).
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| 9. |
- Pottel, Hans, et al.
(författare)
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Standardization of serum creatinine is essential for accurate use of unbiased estimated GFR equations : evidence from three cohorts matched on renal function
- 2022
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Ingår i: Clinical Kidney Journal. - : Oxford University Press. - 2048-8505 .- 2048-8513. ; 15:12, s. 2258-2265
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Tidskriftsartikel (refereegranskat)abstract
- Background: Differences in the performance of estimated glomerular filtration rate (eGFR) equations have been attributed to the mathematical form of the equations and to differences between patient demographics and measurement methods. We evaluated differences in serum creatinine (SCr) and eGFR in cohorts matched for age, sex, body mass index (BMI) and measured GFR (mGFR).Methods: White North Americans from Minnesota (n = 1093) and the Chronic Renal Insufficiency Cohort (CRIC) (n = 1548) and White subjects from the European Kidney Function Consortium (EKFC) cohort (n = 7727) were matched for demographic patient characteristics (sex, age +/- 3 years, BMI +/- 2.5 kg/m(2)) and renal function (mGFR +/- 3 ml/min/1.73 m(2)). SCr was measured with isotope dilution mass spectrometry (IDMS)-traceable assays in the Minnesota and EKFC cohorts and with non-standardized SCr assays recalculated to IDMS in the CRIC. The Minnesota cohort and CRIC shared a common method to measure GFR (renal clearance of iothalamate), while the EKFC cohort used a variety of exogenous markers and methods, all with recognized sufficient accuracy. We compared the SCr levels and eGFR predictions [for Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and EKFC equations] of patients fulfilling these matching criteria.Results: For 305 matched individuals, mean SCr (mg/dL) was not different between the Minnesota and EKFC cohorts (females 0.83 +/- 0.20 versus 0.86 +/- 0.23, males 1.06 +/- 0.23 versus 1.12 +/- 0.37; P > .05) but significantly different from the CRIC [females 1.13 +/- 0.23 (P < .0001), males 1.42 +/- 0.31 (P < .0001)]. The CKD-EPI equations performed better than the EKFC equation in the CRIC, while the opposite was true in the Minnesota and EKFC cohorts.Conclusion: Significant differences in SCr concentrations between the Minnesota and EKFC cohorts versus CRIC were observed in subjects with the same level of mGFR and equal demographic characteristics and can be explained by the difference in SCr calibration.Lay Summary: Standardization of serum creatinine (SCr) measurement is fundamental for estimating glomerular filtration rate (GFR). We used data with GFR measured by a reference method from three cohorts: Chronic Renal Insufficiency Cohort (CRIC, n = 1548), Minnesota cohort (n = 1093) and European Kidney Function Consortium cohort (EKFC; n = 7727). In the EKFC and Minnesota cohorts, SCr was measured by standardized methods, although SCr 'calibration' was more debatable in the CRIC. GFR was measured by the same method in the CRIC and Minnesota cohort. Then we matched 305 White subjects for sex, measured GFR (+/- 3 ml/min/1.73 m(2)), age (+/- 3 years) and body mass index (+/- 2.5 kg/m(2)). From these matched subjects we showed that the association between SCr and measured GFR was quite similar between subjects from the Minnesota and EKFC cohorts, but different between the CRIC and EKFC cohort and between the Minnesota cohort and CRIC. These differences lead to discrepancies in the analysis of the performance of different creatinine-based equations.
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