Uremic syndrome results from malfunctioning of various organ systems due to the retention of uremic toxins which, under normal conditions, would be excreted into the urine and/or metabolized by the ...kidneys. The aim of this study was to elucidate the mechanisms underlying the renal elimination of uremic toxin creatinine that accumulate in chronic renal failure. Quantitative investigation of the plausible correlations was performed by spectroscopy, calorimetry, molecular docking and accessibility of surface area. Alkalinization of normal plasma from pH 7.0 to 9.0 modifies the distribution of toxin in the body and therefore may affect both the accumulation and the rate of toxin elimination. The ligand loading of HSA with uremic toxin predicts several key side chain interactions of site I that presumably have the potential to impact the specificity and impaired drug binding. These findings provide useful information for elucidating the complicated mechanism of toxin disposition in renal disease state.
Recognition and Sensing of Creatinine Guinovart, Tomàs; Hernández-Alonso, Daniel; Adriaenssens, Louis ...
Angewandte Chemie (International ed.),
February 12, 2016, Letnik:
55, Številka:
7
Journal Article
Recenzirano
Current methods for creatinine quantification suffer from significant drawbacks when aiming to combine accuracy, simplicity, and affordability. Here, an unprecedented synthetic receptor, an ...aryl‐substituted calix4pyrrole with a monophosphonate bridge, is reported that displays remarkable affinity for creatinine and the creatininium cation. The receptor works by including the guest in its deep and polar aromatic cavity and establishing directional interactions in three dimensions. When incorporated into a suitable polymeric membrane, this molecule acts as an ionophore. A highly sensitive and selective potentiometric sensor suitable for the determination of creatinine levels in biological fluids, such as urine or plasma, in an accurate, fast, simple, and cost‐effective way has thus been developed.
Creatinine quantification: A monophosphonate‐bridge calix4pyrrole cavitand traps creatinine and the creatininium cation in its deep and polar aromatic cavity. The receptor offers complementary hydrogen‐bonding sites to the polar functional groups of the guest. Its use as an ionophore enhances the analytical performance of ion‐selective electrodes and enables the determination of creatinine levels in biological samples.
Aims
Changes in maternal serum C‐peptide have been described during pregnancy in women with Type 1 diabetes. We aimed to determine whether in these women, C‐peptide, as measured by the urinary ...C‐peptide creatinine ratio (UCPCR), display changes during the course of pregnancy and in the postpartum period.
Methods
In this longitudinal study including 26 women, UCPCR was measured in the first, second, and third trimester of pregnancy, and postpartum, using a high sensitivity two‐step chemiluminescent microparticle immunoassay.
Results
UCPCR was detectable in 7/26 (26.9%) participants in the first trimester, 10/26 (38.4%) in the second trimester, and 18/26 (69.2%) in the third trimester. Changes in UCPCR concentrations were observed throughout pregnancy, significantly increasing from first to third trimester. UCPCR concentration in the three trimesters was associated with a shorter duration of diabetes and in the third trimester also with first trimester UCPCR.
Conclusion
UCPCR detects longitudinal changes during pregnancy in women with type 1 diabetes mellitus, more marked in those with shorter diabetes duration.
•Urine creatinine measurements ≤2 mmol/L are underestimated on the Siemens Vista.•This may affect spot urine biomarkers reporting.•Laboratories may be at risk of delivering incorrect results.
While ...considerable efforts have been accomplished to standardize the measurement of plasma creatinine (PCr), urine creatinine (UCr) has not been subject to the same scrutiny. UCr is importantly used when measuring biomarkers in spot urines, to assess urine output and variable dilution of urine samples. Here, we report underestimation of Jaffe UCr measurements on the Siemens Dimension Vista® analyzer, critically affecting samples with UCr ≤2 mmol/L. We demonstrate that this error is caused by automatic urine pre-dilution by the Vista’s «urine mode», and that UCr measured in «plasma mode» without pre-dilution does not present this error. In the absence of a comprehensive solution proposed by Siemens, we propose simple formulae that can be easily implemented in a laboratory to correct these low UCr measurements. Importantly, the observed UCr underestimation can significantly influence reported results for biomarkers/UCr ratios measured in spot urine. Indeed, these results can be overestimated up to +84.4 % before correction using our formulae. This can sometimes lead to misclassification according to clinical thresholds, e.g. Kidney disease: improving global outcomes (KDIGO) guidelines for urine albumin/creatinine. This highlights the need for every clinical laboratory to assess the detection limits of their assays, including for lesser-discussed parameters such as UCr. Indeed, the error we reported here may affect other urine assays performing systematic urine pre-dilution and could have significant repercussions on the clinical management of patients.
This paper reviews the entire recent global tendency for creatinine measurement. Creatinine biosensors involve complex relationships between biology and micro-mechatronics to which the blood is ...subjected. Comparison between new and old methods shows that new techniques (e.g. Molecular Imprinted Polymers based algorithms) are better than old methods (e.g. Elisa) in terms of stability and linear range. All methods and their details for serum, plasma, urine and blood samples are surveyed. They are categorized into five main algorithms: optical, electrochemical, impedometrical, Ion Selective Field-Effect Transistor (ISFET) based technique and chromatography. Response time, detection limit, linear range and selectivity of reported sensors are discussed. Potentiometric measurement technique has the lowest response time of 4–10s and the lowest detection limit of 0.28nmolL−1 belongs to chromatographic technique. Comparison between various techniques of measurements indicates that the best selectivity belongs to MIP based and chromatographic techniques.
► All sensors for creatinine measurement are categorized into five main groups. ► Their mechanisms, subsystems, benefits and problems are explained. ► Response time, interfering parameters, detection limit and linear range are studied. ► The MIP based method is specified as the best method regarding to above parameters.
Acute kidney injury Ronco, Claudio; Bellomo, Rinaldo; Kellum, John A
The Lancet (British edition),
11/2019, Letnik:
394, Številka:
10212
Journal Article
Recenzirano
Acute kidney injury (AKI) is defined by a rapid increase in serum creatinine, decrease in urine output, or both. AKI occurs in approximately 10–15% of patients admitted to hospital, while its ...incidence in intensive care has been reported in more than 50% of patients. Kidney dysfunction or damage can occur over a longer period or follow AKI in a continuum with acute and chronic kidney disease. Biomarkers of kidney injury or stress are new tools for risk assessment and could possibly guide therapy. AKI is not a single disease but rather a loose collection of syndromes as diverse as sepsis, cardiorenal syndrome, and urinary tract obstruction. The approach to a patient with AKI depends on the clinical context and can also vary by resource availability. Although the effectiveness of several widely applied treatments is still controversial, evidence for several interventions, especially when used together, has increased over the past decade.
Creatinine is the most important parameter to be determined in the diagnosis of renal, muscular and thyroid function. The most common method for the determination of creatinine is Jaffe's reaction, a ...routine practice for blood and urine analysis. However, in cases of icteric and haemolyzed blood samples, interference occurs during the estimation of creatinine by other constituents present in the blood like bilirubin, creatine, and urea, which lead to wrong diagnosis. To overcome such difficulty, we have developed a silver nanoparticle (Ag NPs) based sensor for the selective determination of creatinine. In this study, a new approach has been given to the traditional Jaffe's reaction, by coating Ag NPs with picric acid (PA) to form an assembly that can selectively detect creatinine. The Ag NPs based sensor proficiently and selectively recognizes creatinine due to the ability of picric acid to bind with it and form a complex. The nanoassembly and the interactions were investigated by transmission electron microscopy (TEM), dynamic light scattering (DLS) analysis, UV-Vis spectroscopy, FT-IR spectroscopy and ESI-MS, which demonstrated the binding affinity of creatinine with PA-capped Ag NPs. A linear correlation was obtained in the range of 0.01 μM-1 μM with an R(2) value of 0.9998 and a lower detection limit of 8.4 nM. The sensor was successfully applied to different types of blood and CSF samples for the determination of creatinine, and the results were compared to that of the Jaffe's method. With the advantages of high sensitivity, selectivity and low sample volume, this method is potentially suitable for the on-site monitoring of creatinine.
Creatinine is a metabolic product of creatine phosphate in muscles, which provides energy to muscle tissues. Creatinine has been considered as indicator of renal function specifically after dialysis, ...thyroid malfunction and muscle damage. The normal level of creatinine in the serum and its excretion through urine in apparently healthy individuals is 45–140 μM and 0.8–2.0 gm/day respectively. The level of creatinine reaches >1000 μM in serum during renal, thyroid and kidney dysfunction or muscle disorder. A number of conventional methods such as colorimetric, spectrophotometric and chromatographic are available for determination of creatinine. Besides the advantages of being highly sensitive and selective, these methods have some drawbacks like time-consuming, requirement of sample pre-treatment, high cost instrumental set-up and skilled persons to operate. The sensors/biosensors overcome these drawbacks, as these are fast, easy, cost effective and highly sensitive. This review article describes the classification, operating principles, merits and demerits of various creatinine sensors/biosensors, specifically nanomaterials based biosensors. Creatinine biosensors work optimally within 2–900 s, potential range 0.1–1.0 V, pH range 4.0–10.0, temperature range 25–35 °C and had linear range, 0.004–30000 µM for creatinine with the detection limit between 0.01.01 µM and 520 µM. These biosensors measured creatinine level in sera and urine samples and had storage stability between 4 and 390 days, while being stored dry at 4 °C. The future perspective for further improvement and commercialization of creatinine biosensors are discussed.
•Review illustrates classification of creatinine biosensors with their merits and demerits.•Creatinine biosensors work ideally within 2–900 s, between pH, 4.0–10.0 and temp 25–35 °C and linear range, 0.004–30,000 µM.•Detection limits of creatinine biosensors are between 0.01 μM and 520 µM.•Fabrication of low cost NPs based creatinine biosensors along with their improved sensitivity and stability has been discussed.•The future research could be focused on miniaturization of creatinine biosensors.
Albuminuria is a well-known predictor of chronic kidney disease in patients with type 2 diabetes mellitus (DM). However, proteinuria is associated with chronic complications in patients without ...albuminuria. In this retrospective cohort study, we explored whether non-albumin proteinuria is associated with all-cause mortality and compared the effects of non-albumin proteinuria on all-cause mortality between patients with and without albuminuria. We retrospectively collected data from patients with type 2 DM for whom we had obtained measurements of both urinary albumin-to-creatinine ratio (UACR) and urinary protein-to-creatinine ratio (UPCR) from the same spot urine specimen. Urinary non-albumin protein-creatinine ratio (UNAPCR) was defined as UPCR-UACR. Of the 1809 enrolled subjects, 695 (38.4%) patients died over a median follow-up of 6.4 years. The cohort was separated into four subgroups according to UACR (30 mg/g) and UNAPCR (120 mg/g) to examine whether these indices are associated with all-cause mortality. Compared with the low UACR and low UNAPCR subgroup as the reference group, multivariable Cox regression analyses indicated no significant difference in mortality in the high UACR and low UNAPCR subgroup (hazard ratio HR 1.189, 95% confidence interval CI 0.889-1.589, P = 0.243), but mortality risks were significantly higher in the low UACR and high UNAPCR subgroup (HR 2.204, 95% CI 1.448-3.356, P < 0.001) and in the high UACR with high UNAPCR subgroup (HR 1.796, 95% CI 1.451-2.221, P < 0.001). In the multivariable Cox regression model with inclusion of both UACR and UNAPCR, UNAPCR ≥ 120 mg/g was significantly associated with an increased mortality risk (HR 1.655, 95% CI 1.324-2.070, P < 0.001), but UACR ≥ 30 mg/g was not significantly associated with mortality risk (HR 1.046, 95% CI 0.820-1.334, P = 0.717). In conclusion, UNAPCR is an independent predictor of all-cause mortality in patients with type 2 DM.
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