| 1. |
- Adoberg, Annika, et al.
(författare)
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Treatment with Paracetamol Can Interfere with the Intradialytic Optical Estimation in Spent Dialysate of Uric Acid but Not of Indoxyl Sulfate
- 2022
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Ingår i: Toxins. - : MDPI. - 2072-6651. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Optical online methods are used to monitor the haemodialysis treatment efficiency of end stage kidney disease (ESKD) patients. The aim of this study was to analyse the effect of the administration of UV-absorbing drugs, such as paracetamol (Par), on the accuracy of optical monitoring the removal of uremic toxins uric acid (UA) and indoxyl sulfate (IS) during standard haemodialysis (HD) and haemodiafiltration (HDF) treatments. Nine patients received Par in daily dosages 1-4 g for 30 sessions. For 137 sessions, in 36 patients the total daily dosage of UV-absorbing drugs was less than 500 mg, and for 6 sessions 3 patients received additional UV-absorbing drugs. Par administration slightly affected the accuracy of optically assessed removal of UA expressed as bias between optically and laboratory-assessed reduction ratios (RR) during HD but not HDF employing UV absorbance of spent dialysate (p < 0.05) at 295 nm wavelength with the strongest correlation between the concentration of UA and absorbance. Corresponding removal of IS based on fluorescence at Ex280/Em400 nm during HD and HDF was not affected. Administration of UV-absorbing drugs may in some settings influence the accuracy of optical assessments in spent dialysate of the removal of uremic solutes during haemodialysis treatment of ESKD patients.
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| 2. |
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| 3. |
- Arund, Jurgen, et al.
(författare)
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Is Fluorescence Valid to Monitor Removal of Protein Bound Uremic Solutes in Dialysis?
- 2016
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the contribution and removal dynamics of the main fluorophores during dialysis by analyzing the spent dialysate samples to prove the hypothesis whether the fluorescence of spent dialysate can be utilized for monitoring removal of any of the protein bound uremic solute. A high performance liquid chromatography system was used to separate and quantify fluorophoric solutes in the spent dialysate sampled at the start and the end of 99 dialysis sessions, including 57 hemodialysis and 42 hemodiafiltration treatments. Fluorescence was acquired at excitation 280 nm and emission 360 nm. The main fluorophores found in samples were identified as indole derivatives: tryptophan, indoxyl glucuronide, indoxyl sulfate, 5-hydroxy-indoleacetic acid, indoleacetyl glutamine, and indoleacetic acid. The highest contribution (35 +/- 11%) was found to arise from indoxyl sulfate. Strong correlation between contribution values at the start and end of dialysis (R-2 = 0.90) indicated to the stable contribution during the course of the dialysis. The reduction ratio of indoxyl sulfate was very close to the decrease of the total fluorescence signal of the spent dialysate (49 +/- 14% vs 51 +/- 13% respectively, P = 0.30, N = 99) and there was strong correlation between these reduction ratio values (R-2 = 0.86). On-line fluorescence measurements were carried out to illustrate the technological possibility for real-time dialysis fluorescence monitoring reflecting the removal of the main fluorophores from blood into spent dialysate. In summary, since a predominant part of the fluorescence signal at excitation 280 nm and emission 360 nm in the spent dialysate originates from protein bound derivatives of indoles, metabolites of tryptophan and indole, the fluorescence signal at this wavelength region has high potential to be utilized for monitoring the removal of slowly dialyzed uremic toxin indoxyl sulfate.
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| 4. |
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| 5. |
- Fridolin, Ivo, et al.
(författare)
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A New Optical Method for Measuring Creatinine Concentration Removed During Dialysis
- 2010
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Ingår i: XII Mediterranean Conference on Medical and Biological Engineering and Computing 2010 IFMBE Proceedings, 2010. - Berlin, Heidelberg : Springer. - 9783642130380 - 9783642130397 ; , s. 379-382
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to compare creatinine (Cr) concentration measurements removed during dialysis by two optical algorithms based on single wavelength and multiwavelength UV-absorbance. Ten uremic patients, three females and seven males, mean age 62.6 ± 18.6 years, on chronic thrice-weekly hemodialysis were included in the study. Double-beam spectrophotometer (Shimatsu UV-2401 PC, Japan) was used for the determination of UV-absorbance in the collected spent dialysate samples. Two optical algorithms were developed to calculate Cr concentration removed during dialysis from measured UVabsorbance: (i) an algorithm utilizing only a single wavelength, revealing Cr concentration Cr_sw; (ii) an algorithm utilizing several wavelengths (multiwavelength algorithm), revealing Cr concentration Cr_mw. The mean value of Cr estimated at the laboratory was 107 ± 46,7 micromol/l, while UV-absorbance as Cr_sw (242 nm) was 107 ± 42.7 micromol/l, and 107 ± 44.7 micromol/l as Cr_mw. The mean concentrations were not significantly different (P = 0.99). The systematic errors, using Cr_lab as a reference, were -2.7% for Cr_sw and -1.7% for Cr_mw, and random errors were 17.3% and 13.6% for Cr_sw and Cr_mw, respectively. The systematic error was not significantly different for two optical algorithms (P = 0.25). The random error decreased significantly (P < 0.05) using Cr_mw algorithm compared to the Cr_sw model. In summary, the creatinine concentration removed during dialysis can be estimated with UV-absorbance technique.
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| 6. |
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| 7. |
- Holmar, Jana, et al.
(författare)
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An Optical Method for Serum Calcium and Phosphorus Level Assessment during Hemodialysis
- 2015
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Ingår i: Toxins. - BASEL, SWITZERLAND : MDPI AG. - 2072-6651. ; 7:3, s. 719-727
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Tidskriftsartikel (refereegranskat)abstract
- Survival among hemodialysis patients is disturbingly low, partly because vascular calcification (VC) and cardiovascular disease are highly prevalent. Elevated serum phosphorus (P) and calcium (Ca) levels play an essential role in the formation of VC events. The purpose of the current study was to reveal optical monitoring possibilities of serum P and Ca values during dialysis. Twenty-eight patients from Tallinn (Estonia) and Linköping (Sweden) were included in the study. The serum levels of Ca and P on the basis of optical information, i.e., absorbance and fluorescence of the spent dialysate (optical method) were assessed. Obtained levels were compared in means and SD. The mean serum level of Ca was 2.54 ± 0.21 and 2.53 ± 0.19 mmol/L; P levels varied between 1.08 ± 0.51 and 1.08 ± 0.48 mmol/L, measured in the laboratory and estimated by the optical method respectively. The levels achieved were not significantly different (p = 0.5). The Bland-Altman 95% limits of agreement between the two methods varied from -0.19 to 0.19 for Ca and from -0.37 to 0.37 in the case of P. In conclusion, optical monitoring of the spent dialysate for assessing the serum levels of Ca and P during dialysis seems to be feasible and could offer valuable and continuous information to medical staff.
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| 8. |
- Holmar, Jana, et al.
(författare)
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Estimation of dialysis patients survival through combined approach of small molecule uremic markers
- 2014
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Ingår i: Proceedings of the Estonian Academy of Sciences. - : Estonian Academy Publishers. - 1736-6046 .- 1736-7530. ; 63:3, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- Survival rate of dialysis patients is still alarmingly low and various factors may have in it an important role. The purpose of this study was to observe the relationship between the survival of dialysis patients and the serum level of urea, creatinine, and uric acid (UA). Serum urea and creatinine concentrations may express patients nutritional status and muscle mass, and high UA value may refer to higher risk for cardiovascular events. The idea of combining the concentrations and removal of urea and UA into a single model for predicting the patients outcome is introduced. The study included 33 hemodialysis patients from Link ping, Sweden and 10 from Tallinn, Estonia. Kaplan-Meier analysis was used for survival analysis. Logistic and Cox regression analysis was applied to create models for predicting patients three-year survival. It was observed that higher serum UA is significantly related to poor survival in dialysis patients (p = 0.026). A reverse effect was observed in case of urea (p = 0.095). The level of creatinine was not related to survival (p = 0.905). The best logistic regression model for predicting patients outcome included both UA and urea based parameters (Chi Square 21.0, p = 0.0001). Survival of dialysis patients seems to be determined by a set of causal factors and combined models may have a predictive relevance. A possibility for automatic online monitoring of small molecule uremic markers is proposed. Since the number of participating patients was small, larger studies including more patients and testing the models in independent validation cohort is the future goal.
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