Journal articles: 'Creatinine Colorimetric Assay Kit'

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Elgamouz, Abdelaziz, Chahlaa Nassab, Alaa Bihi, Somaya A. I. Mohamad, Aisha H. S. A. Almusafri, Salman S. Alharthi, Sarah A. E. Abdulla, and Shashikant P. Patole. "Encapsulation Capacity of β-Cyclodextrin Stabilized Silver Nanoparticles towards Creatinine Enhances the Colorimetric Sensing of Hydrogen Peroxide in Urine." Nanomaterials 11, no. 8 (July 24, 2021): 1897. http://dx.doi.org/10.3390/nano11081897.

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The β-cyclodextrin shell of synthesized silver nanoparticles (βCD-AgNPs) are found to enhance the detection of hydrogen peroxide in urine when compared to the Horse Radish Peroxidase assay kit. Nanoparticles are confirmed by the UV-Vis absorbance of their localized surface plasmonic resonance (LSPR) at 384 nm. The mean size of the βCD-AgNPs is 53 nm/diameter; XRD analysis shows a face-centered cubic structure. The crystalline structure of type 4H hexagonal nature of the AgNPs with 2.4 nm β-CD coating onto is confirmed using aberration corrected high-resolution transmission electron microscopy (HRTEM). A silver atomic lattice at 2.50 Å and 2.41 Å corresponding to (100) and (101) Miller indices is confirmed using the HRTEM. The scope of βCD-AgNPs to detect hydrogen peroxide (H2O2) in aqueous media and human urine is investigated. The test is optimized by examining the effect of volumes of nanoparticles, the pH of the medium, and the kinetic and temperature effect on H2O2 detection. The βCD-AgNPs test is used as a refined protocol, which demonstrated improved sensitivity towards H2O2 in urine compared to the values obtained by the Horse Radish Assay kit. Direct assessment of H2O2 by the βCD-AgNPs test presented always with a linear response in the nM, μM, and mM ranges with a limit of detection of 1.47 nM and a quantitation limit of 3.76 nM. While a linear response obtained from 1.3 to 37.3 nmoles of H2O2/mole creatinine with a slope of 0.0075 and regression coefficient of 0.9955 when the βCD-AgNPs is used as refined test of creatinine. Values ranging from 34.62 ± 0.23 nmoles of H2O2/mole of creatinine and 54.61 ± 1.04 nmoles of H2O2/mole of creatinine when the matrix is not diluted and between 32.16 ± 0.42 nmoles of H2O2/mole of creatinine and 49.66 ± 0.80 nmoles of H2O2/mole of creatinine when the matrix is twice diluted are found in freshly voided urine of seven apparent healthy men aged between 20 and 40 years old.

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Pócsi, István, László Csáthy, V. Anna Oláh, and Robert G. Price. "Assay of N-Acetyl-β-D-Glucosaminidase in Urine from Neonates: Comparison of Two New Colorimetric Methods Using MNP-GlcNAc and VRA-GlcNAc as Substrates." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 29, no. 3 (May 1992): 292–95. http://dx.doi.org/10.1177/000456329202900307.

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The NAG activity present in urine from newborn babies was assayed using two colorimetric procedures with either MNP-GlcNAc or VRA-GlcNAc as substrate and compared with data obtained with the well established PNP-GlcNAc procedure. Both new assays were easy to perform and reproducible. The MNP-GlcNAc method has the advantage that it is now available as a kit; however, the VRA-GlcNAc procedure is more sensitive. NAG activity, creatinine concentration and NAG-index values were determined in normal neonates and within-run imprecision calculated. Excellent correlations were found between MNP-GlcNAc-ase and VRA-GlcNAc-ase indices ( r = 0·984) and between PNP-GlcNAc-ase and VRA-GlcNAc-ase indices ( r = 0.952). When low molecular weight urinary components were removed by gel filtration no significant change in VRA-GlcNAc-ase activity was observed.

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Houcher, Zahira, Bakhouche Houcher, Abderrezak Touabti, Samia Begag, Yonca Egin, and Nejat Akar. "Nutritional Factors, Homocysteine and C677T Polymorphism of the Methylenetetrahydrofolate Reductase Gene in Algerian Subjects with Cardiovascular Disease." Pteridines 23, no. 1 (February 2012): 14–21. http://dx.doi.org/10.1515/pteridines.2012.23.1.14.

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Abstract The C677T variant of methylenetetrahydrofolate reductase (MTHFR), a key enzyme in the remethylation of homocysteine (HCY) to methionine, is a frequent genetic cause of moderate hyperhomocysteinemia (HHCY) among individuals with cardiovascular disease (CVD), and particularly when combined with other factors such as hyperlipidaemia. However, in Algeria the influence of nutrient-gene interactions is not known. The aim of the present study was to explore the influence of age and gender, together with folate status, on the association between the C677T MTHFR polymorphism and plasma total HCY (tHCY) concentrations. This research was carried out as a prospective study on 98 patients hospitalized in the Cardiology Section, University of Sétif, Algeria. Mean age of participants was 57 y (range 20-96 y).The genetic analysis of the MTHFR C677T polymorphism was performed by real-time polymerase chain reaction (PCR) performed on Light Cycler in borosilicate capillaries with MTHFR 677CT polymorphism detection kit. The concentrations of tHCY, folic acid vitamin B12 levels were determined using a competitive immunoassay on the IMMULITE 1000 Analyzers. Plasma total cholesterol, triglycerides, glucose, creatinine and urea concentrations were measured by colorimetric methods. Assays were conducted according to the manufacturers' instructions. Plasma tHCY was significantly higher in the patients with CVD, and HHCY was associated with the presence of mildly elevated serum urea and creatinine (p <0.05). MTHFR gene mutation does not seem to be associated with elevation of plasma tHCY in the studied patients and this lack of correlation could be influenced by the higher folate concentrations in our study. CVD patients with 677CT/TT genotypes had a higher concentration of total cholesterol than those with 677CC genotype (p <0.05). Although, the presence of 677T variant together with hypofolatemia (<15.4 ng/ml) had a more detrimental effect on the level of total cholesterol (p <0.05). Folatemia and vitamin B12 were much higher in 677CC genotype compared to 677CT/TT genotype in CVD subjects without hyperlipidemia (p <0.05). However in patients with hyperlipidemia these values became lower also with 677CC genotype. In conclusion, hyperlipidemia affects the levels of plasma folate and vitamin B12 concentrations independent of mutated MTHFR genotype. The effect of 677T variant on total cholesterol, folate and vitamin B12 concentrations may relate to possible adverse effects of elevated tHCY on lipid profiles and on plasma folate and vitamin B12.

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He, Yi, Xianhui Zhang, and Haili Yu. "Gold nanoparticles-based colorimetric and visual creatinine assay." Microchimica Acta 182, no. 11-12 (June 23, 2015): 2037–43. http://dx.doi.org/10.1007/s00604-015-1546-0.

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Larpent, Liliane, and Christian Verger. "The Need for Using An Enzymatic Colorimetric Assay in Creatinine Determination of Peritoneal Dialysis Solutions." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 10, no. 1 (January 1990): 89–92. http://dx.doi.org/10.1177/089686089001000122.

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The fate of the peritoneal membrane on continuous ambulatory peritoneal dialysis (CAPD) is usually evaluated through the modification of its permeability to various solutes as glucose, creatinine, and urea. Therefore, the accuracy of the methods used for measurements of creatinine is of great importance. A particular problem does exist for creatinine determination as it may be influenced by the presence of glucose. We studied a new enzymatic colorimetric method for creatinine determination in peritoneal dialysis solutions which contain high dextrose concentrations. Creatinine was measured in plasma, urine, and dialysate from 18 patients on CAPD and in pure dextrose solutions, with an enzymatic test (Boehringer Mannheim) and with Jaffe's reaction on two different analyzers: Astra (Beckman) and Eris (Merck). Creatinine results were similar with both assays (Jaffe's reaction and enzymatic test) when measured in blood and urine. However the Jaffe's reaction gave higher creatinine results than the enzymatic test (p < 0.001), when assays were performed in peritoneal dialysis solutions and in pure glucose solutions. In addition, it appeared that other components of dialysis solutions, mainly calcium chloride, influenced unpredictably the results of creatinine with the Jaffe's reaction. We conclude that specific enzymatic test is a more accurate and reliable method to evaluate creatinine kinetics through the peritoneal membrane when determined in CAPD solutions.

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Krausz, Alyse D., Rajan Dewar, and Mark A. Burns. "Accuracy Evaluation of a Tetrabromophenolphthalein Ethyl Ester Colorimetric Assay for Urinary Albumin." Journal of Applied Laboratory Medicine 4, no. 2 (September 1, 2019): 201–13. http://dx.doi.org/10.1373/jalm.2019.030031.

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Abstract Background The tetrabromophenolphthalein ethyl ester (TBPE) assay has been used to quantify urinary albumin in point-of-care devices. We assessed the accuracy of this TBPE assay for urinary albumin through comparison with an established immunoturbidimetric method (ADVIA 1800 Chemistry System, Siemens). Methods We developed a TBPE assay protocol to quantify albumin in the range associated with microalbuminuria (0–200 mg/L). The Jaffe reaction and a 3-dimensional (3D) surface were used to compensate for creatinine interference. Spiked simulated urine samples and patient samples were used to compare the TBPE assay with the immunoturbidimetric method. Multiple linear regression was used to analyze factors that could account for discrepancies between the 2 methods. Results We found that creatinine interfered with the TBPE assay. To compensate, a 3D surface was successfully used to quantify albumin in spiked deionized water and simulated urine samples. In spiked simulated urine samples, the immunoturbidimetric method underestimated the albumin concentration by 2 to 45 mg/L, and the TBPE assay overestimated it by 9 to 82 mg/L. In patient samples, the albumin concentrations measured with the TBPE assay and the immunoturbidimetric method differed by an average of 184 mg/L. Conclusions The TBPE assay is a function of the creatinine concentration, and a 3D surface can be used to provide accurate albumin concentrations for standard samples. The corrected TBPE method and the immunoturbidimetric method deviated from known concentrations of spiked samples. Further investigation and comparisons with a third albumin measurement method, such as LC-MS/MS, are necessary before conclusions on the accuracy of the TBPE assay can be made.

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Magnotti, R. A., G. W. Stephens, R. K. Rogers, and A. J. Pesce. "Microplate measurement of urinary albumin and creatinine." Clinical Chemistry 35, no. 7 (July 1, 1989): 1371–75. http://dx.doi.org/10.1093/clinchem/35.7.1371.

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Abstract We describe microplate methods for measurement of human urinary albumin (HUA) by competitive enzyme-linked immunosorbant assay (ELISA) and creatinine with a modified commercial enzymatic kit. Incorporation of substrate mixing into the competitive ELISA changes the dynamic absorbance-concentration response, greatly simplifying calculations and improving sensitivity and accuracy. Measurement of creatinine in urine and plasma samples with a commercially available enzymatic kit modified for analysis by use of an inexpensive microplate reader produced values comparable in precision and accuracy to those obtained by an automated kinetic Jaffé method.

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Paz, Matt Andrew, and Jesse Seegmiller. "Interference on the Abbott i-STAT creatinine assay caused by hydroxyurea." American Journal of Clinical Pathology 158, Supplement_1 (November 1, 2022): S19—S20. http://dx.doi.org/10.1093/ajcp/aqac126.034.

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Abstract Serum creatinine is an important biomarker used for estimating glomerular filtration rate (eGFR). The present study was designed after a patient at our institution had a significantly elevated creatinine result taken from an i-STAT point of care test that utilizes electrochemical detection. The patient’s creatinine from the i-STAT was 3.8 mg/dL and was not consistent with their clinical history. The patient’s previous creatinine taken 2 days prior was 1.39 mg/dL and 1.27 mg/dL seven days prior. Both previous readings were measured with the Siemens Dimension Vista 1500 using a colorimetric enzymatic creatinine method. A subsequent creatinine measured on the Siemens Dimension Vista 1500 was 1.30 mg/dL. Upon chart review, the clinical team noted that the patient is taking 500 mg of hydroxyurea daily for treatment of a myeloproliferative disorder. Review of the i-STAT package insert revealed hydroxyurea as a known interfering substance and states for every 100 µmol/L hydroxyurea in the specimen, creatinine will be increased by approximately 1.85 mg/dL. Review of literature described the positive interference caused by hydroxyurea for the i-STAT creatinine and glucose assays but did not explain the mechanism of this positive interference. In order to characterize the mechanism of hydroxyurea interference, we investigated the situation further. A pool of plasma was spiked with hydroxyurea. The spiked pool was serial diluted (x2, x4, x8, x16, x32, x64, x128) to observe the creatinine results in the presence of and absence of hydroxyurea. The dilution series was analyzed using the Vista enzymatic creatinine and the Abbott i-STAT enzymatic creatinine methods. The i-STAT creatinine results show increasing creatinine concentration from interference as the concentration of hydroxyurea increased. The dilution series suggests increasing positive interference with hydroxyurea. Positive creatinine interference with hydroxyurea was not observed when analyzed on the Vista platform. Hydroxyurea is a widely used treatment for myeloproliferative disorders and also for managing sickle cell disease. Hydroxyurea is known to cause positive interference in the i-STAT enzymatic creatine method that uses electrochemical detection, with the degree of interference correlating with the concentration of hydroxyurea. The Vista colorimetric enzymatic creatinine method was not observed to have hydroxyurea interference. While both methods employ enzymatic reagent systems the final detection approach is important. Patients undergoing hydroxyurea treatment should avoid i-STAT measurement systems for creatinine.

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Yuen, Peter S. T., Stephen R. Dunn, Takehiko Miyaji, Hideo Yasuda, Kumar Sharma, and Robert A. Star. "A simplified method for HPLC determination of creatinine in mouse serum." American Journal of Physiology-Renal Physiology 286, no. 6 (June 2004): F1116—F1119. http://dx.doi.org/10.1152/ajprenal.00366.2003.

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Mouse models are frequently used to study renal function. However, mouse serum contains chromagens that interfere with standard picric acid-based assays for serum creatinine. Several alternative methods exist for serum creatinine measurements, including assay by high-performance liquid chromatography (HPLC), but only one has been adapted to mouse serum. Creatinine was measured in serum by acetonitrile deproteinization, followed by isocratic, cation exchange HPLC. The HPLC method was compared with a standard alkaline picrate colorimetric assay, using serum from animals with low-to-moderate renal injury. Acidification of acetonitrile with HCl in the deproteinization step produced variable results, including an extra peak that interfered with integration of the creatinine peak or loss of the creatinine peak. Deproteinizing with acetonitrile alone resulted in a more reliable measurement of serum creatinine, which was validated by a series of known additions of creatinine standard. The HPLC assay was reproducible with coefficients of variation from 1.6 to 5.1%. The picric acid assay overestimated serum creatinine, when directly compared with the HPLC assay. The extent of overestimation, up to sixfold, was greatest at normal (0.1 to 0.2 mg/dl) to moderately elevated (0.5 mg/dl) serum creatinine levels. Mouse serum contains substances that interfere with standard picric acid assays for creatinine. Our new HPLC assay can accurately detect creatinine from 5 μl of mouse serum. These results support the widespread adoption of HPLC to accurately measure serum creatinine in mouse models of renal injury.

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Gao, Jing-Jhong, Ching-Wei Chiu, Kuo-Hsing Wen, and Cheng-Sheng Huang. "A Compact Detection Platform Based on Gradient Guided-Mode Resonance for Colorimetric and Fluorescence Liquid Assay Detection." Sensors 21, no. 8 (April 15, 2021): 2797. http://dx.doi.org/10.3390/s21082797.

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This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

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Kind, Clive N. "The Measurement of Serum Unsaturated Iron-Binding Capacity in the Presence of Iron-Dextran." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 25, no. 3 (May 1988): 325–26. http://dx.doi.org/10.1177/000456328802500323.

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The standard colorimetric methods most often used for the measurement of serum unsaturated iron binding capacity (UIBC) are subject to gross interference by iron dextran. This paper describes a brief evaluation of an alternative radiometric assay for serum UIBC, based on a commercially available kit method, but incorporating a modification to the manufacturer's protocol. The effects of iron dextran on the assay were determined.

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Chang, Tsui-Hsuan, Kuo-Hao Tung, Po-Wen Gu, Tzung-Hai Yen, and Chao-Min Cheng. "Rapid Simultaneous Determination of Paraquat and Creatinine in Human Serum Using a Piece of Paper." Micromachines 9, no. 11 (November 12, 2018): 586. http://dx.doi.org/10.3390/mi9110586.

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Paraquat intoxication is characterized by acute kidney injury and multi-organ failure, causing substantial mortality and morbidity. This study aims to develop a 2-in-1 paper-based analytical device to detect the concentrations of paraquat and creatinine in human serum, which can help clinicians diagnose patients with paraquat poisoning in a more rapid and geographically unrestricted manner. The procedure involves fabrication of a paper-based analytical device, i.e., printing of design on a filter paper, heating of wax-printed micro zone plates so as molten wax diffusing into and completely through the paper to the other side, forming hydrophobic boundaries that could act as detection zones for the paraquat colorimetric assay, and finally analysis using ImageJ software. The paper employed a colorimetric sodium dithionite assay to indicate the paraquat level in a buffer or human serum system in less than 10 min. In this study, colorimetric changes into blue color could be observed by the naked eye. By curve fitting models of sodium dithionite in normal human serum, we evaluated the serum paraquat levels for five paraquat patients. In the sodium dithionate assay, the measured serum paraquat concentrations in patients 1–5 were 22.59, 5.99, 26.52, 35.19 and 25.00 ppm, respectively. On the other hand, by curve fitting models of the creatinine assay in normal human serum, the measured serum creatinine concentrations were 16.10, 12.92, 13.82, 13.58 and 12.20 ppm, respectively. We found that the analytical performance of this device can compete with the standard of Clinical Laboratory of Chang Gung Memorial Hospital, with a less complicated sample preparation process and more rapid results. In conclusion, this 2-in-1 paper-based analytical device has the advantage of being simple and cheap, enabling rapid detection of paraquat intoxication as well as assessment of renal prognosis.

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Watson, Drew, Joshua Y. C. Yang, Reuben D. Sarwal, Tara K. Sigdel, Juliane M. Liberto, Izabella Damm, Victoria Louie, et al. "A Novel Multi-Biomarker Assay for Non-Invasive Quantitative Monitoring of Kidney Injury." Journal of Clinical Medicine 8, no. 4 (April 12, 2019): 499. http://dx.doi.org/10.3390/jcm8040499.

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The current standard of care measures for kidney function, proteinuria, and serum creatinine (SCr) are poor predictors of early-stage kidney disease. Measures that can detect chronic kidney disease in its earlier stages are needed to enable therapeutic intervention and reduce adverse outcomes of chronic kidney disease. We have developed the Kidney Injury Test (KIT) and a novel KIT Score based on the composite measurement and validation of multiple biomarkers across a unique set of 397 urine samples. The test is performed on urine samples that require no processing at the site of collection and without target sequencing or amplification. We sought to verify that the pre-defined KIT test, KIT Score, and clinical thresholds correlate with established chronic kidney disease (CKD) and may provide predictive information on early kidney injury status above and beyond proteinuria and renal function measurements alone. Statistical analyses across six DNA, protein, and metabolite markers were performed on a subset of residual spot urine samples with CKD that met assay performance quality controls from patients attending the clinical labs at the University of California, San Francisco (UCSF) as part of an ongoing IRB-approved prospective study. Inclusion criteria included selection of patients with confirmed CKD and normal healthy controls; exclusion criteria included incomplete or missing information for sample classification, logistical delays in transport/processing of urine samples or low sample volume, and acute kidney injury. Multivariate logistic regression of kidney injury status and likelihood ratio statistics were used to assess the contribution of the KIT Score for prediction of kidney injury status and stage of CKD as well as assess the potential contribution of the KIT Score for detection of early-stage CKD above and beyond traditional measures of renal function. Urine samples were processed by a proprietary immunoprobe for measuring cell-free DNA (cfDNA), methylated cfDNA, clusterin, CXCL10, total protein, and creatinine. The KIT Score and stratified KIT Score Risk Group (high versus low) had a sensitivity and specificity for detection of kidney injury status (healthy or CKD) of 97.3% (95% CI: 94.6–99.3%) and 94.1% (95% CI: 82.3–100%). In addition, in patients with normal renal function (estimated glomerular filtration rate (eGFR) ≥ 90), the KIT Score clearly identifies those with predisposing risk factors for CKD, which could not be detected by eGFR or proteinuria (p < 0.001). The KIT Score uncovers a burden of kidney injury that may yet be incompletely recognized, opening the door for earlier detection, intervention and preservation of renal function.

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Censi, Simona, Maurizio Iacobone, Stefano Simmini, Jacopo Manso, Giulio Franceschet, Mario Plebani, Anna Chiara Frigo, et al. "PTH: Redefining Reference Ranges in a Healthy Population—The Role of Interfering Factors and the Type of Laboratory Assay." International Journal of Endocrinology 2020 (February 21, 2020): 1–7. http://dx.doi.org/10.1155/2020/1053719.

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Introduction. Parathyroid hormone (PTH) is a linear peptide constituted by 84 amino acids and active in its 1–84 form, but a wide range of PTH forms produced by its post-transcriptional modifications are present in blood. Many assays with different specificities are commercially available. The aim of our study was to compare a 2nd and 3rd generation in healthy population in order to better define the reference range in the healthy population residing in our region. Materials and Methods. 108 subjects (53 females and 55 males) referring to the transfusion donor were enrolled in the study centre in April 2016 and underwent PTH levels measurements with a 3rd generation kit (chemiluminescent immunoassay DiaSorin Liaison) and with a 2nd generation kit (immunoradiometric assay Total Intact PTH Assay (Coated Tube), Scantibodies). Also calcium, phosphate, creatinine, and 25OHD3 were measured. A questionnaire on lifestyle and dietary habits was obtained. Results. The median PTH values obtained with the 2nd generation assay and the whole 3rd generation assay were 20.26 pg/ml and 23.11 pg/ml, respectively. Bland–Altman method showed substantial concordance between the two PTH assays, although with an overestimation of the 3rd generation method over the 2nd generation method. There was no correlation between 3rd generation PTH and 25OHD3 and creatinine. Calcium was negatively correlated with PTH only when measured with 3rd generation kit. Conclusions. On the basis of our data, obtained from healthy subjects, we can conclude that the reference range used by our laboratory was too narrow and was necessary to reestablish normal ranges according to our population. This is useful to avoid hyperparathyroidism misdiagnosis.

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Phillipou, G., S. K. James, C. J. Seaborn, and P. J. Phillips. "Assessment of a simple colorimetric procedure to determine smoking status in diabetic subjects." Clinical Chemistry 40, no. 7 (July 1, 1994): 1296–98. http://dx.doi.org/10.1093/clinchem/40.7.1296.

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Abstract The performance of a colorimetric assay for nicotine metabolites to validate self-reported smoking classification (nonsmoker, ex-smoker, and smoker) was assessed in a group of diabetic patients (n = 201). Comparison of the results with those of cotinine immunoassay (ELISA), by comparing respective areas under receiver operating characteristic curves, established the superiority of the cotinine immunoassay method. Adjusting the urinary concentrations of nicotine metabolites for creatinine excretion significantly lowered test performance. The sensitivity and specificity for the assay of nicotine metabolites to discriminate smoking classification within the diabetic patients at a threshold of > or = 28 mumol/L "cotinine carboxylic acid equivalents" were 68.4% and 98.6%, respectively; the corresponding sensitivity and specificity for urinary cotinine at a cutoff of > or = 0.5 mumol/L were 94.7% and 100%. The low sensitivity of the colorimetric urinary nicotine metabolites assay precludes its application as an objective assessment of smoking status in our patient population.

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Yang, Joshua Y. C., Reuben D. Sarwal, Fernando C. Fervenza, Minnie M. Sarwal, and Richard A. Lafayette. "Noninvasive Urinary Monitoring of Progression in IgA Nephropathy." International Journal of Molecular Sciences 20, no. 18 (September 10, 2019): 4463. http://dx.doi.org/10.3390/ijms20184463.

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Standard methods for detecting and monitoring of IgA nephropathy (IgAN) have conventionally required kidney biopsies or suffer from poor sensitivity and specificity. The Kidney Injury Test (KIT) Assay of urinary biomarkers has previously been shown to distinguish between various kidney pathologies, including chronic kidney disease, nephrolithiasis, and transplant rejection. This validation study uses the KIT Assay to investigate the clinical utility of the non-invasive detection of IgAN and predicting the progression of renal damage over time. The study design benefits from longitudinally collected urine samples from an investigator-initiated, multicenter, prospective study, evaluating the efficacy of corticosteroids versus Rituximab for preventing progressive IgAN. A total of 131 urine samples were processed for this study; 64 urine samples were collected from 34 IgAN patients, and urine samples from 64 demographically matched healthy controls were also collected; multiple urinary biomarkers consisting of cell-free DNA, methylated cell-free DNA, DMAIMO, MAMIMO, total protein, clusterin, creatinine, and CXCL10 were measured by the microwell-based KIT Assay. An IgA risk score (KIT-IgA) was significantly higher in IgAN patients as compared to healthy control (87.76 vs. 14.03, p < 0.0001) and performed better than proteinuria in discriminating between the two groups. The KIT Assay biomarkers, measured on a spot random urine sample at study entry could distinguish patients likely to have progressive renal dysfunction a year later. These data support the pursuit of larger prospective studies to evaluate the predictive performance of the KIT-IgA score in both screening for non-invasive diagnosis of IgAN, and for predicting risk of progressive renal disease from IgA and utilizing the KIT score for potentially evaluating the efficacy of IgAN-targeted therapies.

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Sadeghi, Susan, and Mohadeseh Hosseinpour-Zaryabi. "A highly selective colorimetric assay for the determination of creatinine in biological samples using gluconic acid capped silver nanoparticles after ionic liquid based dispersive liquid phase microextraction." Canadian Journal of Chemistry 99, no. 4 (April 2021): 382–89. http://dx.doi.org/10.1139/cjc-2020-0271.

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A dispersive liquid-phase microextraction method combined with UV–vis spectrophotometry was utilized to highly selective determination of creatinine in human serum and urine samples. To overcome the interferences in complex matrices, creatinine reacted with 1,4-naphthoquinone-2- potassium sulfonate reagent to produce a red coloured product that could be extracted into a small volume of 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM]PF6) ionic liquid solvent. To increase the sensitivity of the assay, gluconic acid capped silver nanoparticles (Ag NPs) were used. On addition of Ag NPs to the red coloured extracted product, the solution turned to blue accompanied with a red shift in wavelength around 620 nm that could be detected by the naked eye. The effective variables on the determination of creatinine such as concentration of the reagent, amount of formic and hydrochloric acids, type and volume of the extractant, and concentration of Ag NPs were investigated. Under the optimal conditions, the calibration plot was bimodal with linear ranges from 0.1 to 1.5 µg mL−1 and 1.5 to 105 µg mL−1 creatinine with a limit of detection 0.1 µg mL−1. The relative standard deviation for five measurements at 35 µg mL−1 concentration level was 3.8%. The newly developed assay was used for the determination of creatinine in human serum and urine specimens with satisfactory results.

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Rasheed, Tahir, Chuanlong Li, Yinglin Zhang, Faran Nabeel, Jiaxin Peng, Jie Qi, Lidong Gong, and Chunyang Yu. "Rhodamine-based multianalyte colorimetric probe with potentialities as on-site assay kit and in biological systems." Sensors and Actuators B: Chemical 258 (April 2018): 115–24. http://dx.doi.org/10.1016/j.snb.2017.11.100.

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Meléndez, Daniela M., Sonia Marti, Luigi Faucitano, Derek B. Haley, Timothy D. Schwinghamer, Wiolene M. Nordi, and Karen S. Schwartzkopf-Genswein. "PSVII-3 Correlations between L-lactate concentrations obtained using a handheld lactate analyser and a lactate assay colorimetric kit in beef cattle transported by road." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 296–97. http://dx.doi.org/10.1093/jas/skaa278.535.

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Abstract Blood metabolites are used to assess a variety of animal conditions for veterinary diagnosis and research. Concentration of metabolites in blood can be measured using a commercially-available lab-based assay or in real-time using a handheld device developed to be more time- and cost-effective than the lab-based method. Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer (Lactate Scout, EFK Diagnostics, Barleben, Germany) and a lactate assay colorimetric kit (Lactate Assay Kit, Cell Biolabs Inc., San Diego, CA). Blood samples were collected by venipuncture from 96 steers (245 ± 35.7 kg BW) prior to (L1) and after 36 h, and prior to and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in colorimetric analysis. Pearson correlations were calculated to determine the relationship between the experimental methods for the quantification of L-lactate concentrations. The strengths and levels of statistical significance of the correlation varied over the observed time points, r = -0.03, P = 0.75 (L1) to r = 0.75, P = < 0.0001 (d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, P < 0.001). Based on the experimental results, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay for measuring L-lactate in transported cattle, due to variability across sampling time points and weak correlation with the traditional enzymatic method.

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Omer, Zahra Saad, Ann-Charlotte Wallenhammar, and Maria Viketoft. "Development of Loop-Mediated Isothermal Amplification Assay for Rapid Detection and Analysis of the Root-Knot Nematode Meloidogyne hapla in Soil." Horticulturae 8, no. 2 (January 19, 2022): 87. http://dx.doi.org/10.3390/horticulturae8020087.

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Soil analysis is crucial for estimating the risk of crop damage by the root-knot nematode Meloidogyne hapla. Here, we developed an analysis assay based on Loop-mediated Isothermal Amplification (LAMP). The LAMP primers were verified for specificity against 10 different nematode species. A manual soil DNA extraction, referred to as SKMM, was developed and compared with a FastDNA kit followed by DNA purification. DNA was extracted with both methods from artificially inoculated soils as well as from naturally infested soil collected from farm fields. The primers exclusively amplified DNA from M. hapla with both colorimetric and real-time LAMP. The detection limit was 193 gene copies and 0.0016 juveniles (12 pg µL−1) per reaction. DNA concentrations and purity (A260/A230) were significantly higher using the SKMM procedure compared with the kit. From the field samples collected in 2019, DNA was amplified from 16% of samples extracted with SKMM and from 11% of samples using the kit. Occurrence of M. hapla DNA was confirmed in soil samples from two out of six field soils in 2020 using both real-time LAMP and qPCR. In conclusion, the developed real-time LAMP is a fast and specific assay for detection and quantification of M. hapla DNA in soil.

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Paduszyński, Piotr, Ewa Chodurek, Marzena Jaworska-Kik, Arkadiusz Orchel, Anna Kaps, and Janusz Kasperczyk. "Antiproliferative and proapoptotic activity of ursolic acid in human skin malignant melanoma cells." Postępy Higieny i Medycyny Doświadczalnej 72 (December 31, 2018): 1148–55. http://dx.doi.org/10.5604/01.3001.0012.8261.

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Aim: Pentacyclic triterpenoid – ursolic acid is one of the most promising anticancer agents of biological origin. Especially modulation of cellular signalling pathways (STAT3, TRAIL, IRE1-TRAF-2-ASK1 signalling pathways) and enzymes inhibition (MMP-7, u-PA) may lead to apoptosis induction as well as inhibition of the following: tumorigenesis, tumor promotion, metastasis and angiogenesis. Melanoma malignum is one of the most malignant invasive cancers. It is characterized by a fast growth rate, multiple metastases, and late diagnosis. Substances of natural origin, including ursolic acid, have attracted broad attention recently, as potential antimelanoma agents. The aim of the study was to evaluate the influence of ursolic acid on the proliferation and apoptosis in human G361 malignant melanoma cell line. Material/Methods: The effect of ursolic acid on the number of G361 cells was measured using In Vitro Toxicology Assay Kit Sulforhodamine B. DNA synthesis of G361 cells was evaluated by means of BrdU colorimetric immunoassay. Detection of caspase-3 activity was performed using Caspase 3 Assay Kit, Colorimetric. Results: Ursolic acid had a strong effect on the number and proliferation of G361 cells. The most remarkable effect was observed at a concentration of 20 μM. Our results suggest that in some concentrations ursolic acid can induce apoptosis via activation of caspase-3 in melanoma G361 cells. Conclusions: The presented results suggest that ursolic acid can have an influence in a dose and time dependent manner on skin melanoma malignant cells. Ursolic acid has antiproliferative and cytotoxic activity and it can induce apoptosis in human melanoma malignum G361 cell line.

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Siedel, J., R. Deeg, H. Seidel, H. Möllering, J. Staepels, H. Gauhl, and J. Ziegenhorn. "Fully Enzymatic Colorimetric Assay of Serum and Urine Creatinine Which Obviates the Need for Sample Blank Measurements." Analytical Letters 21, no. 6 (June 1988): 1009–17. http://dx.doi.org/10.1080/00032718808071927.

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Ye, Zhiming, Li Zhang, Ruizhao Li, Wei Dong, Shuangxin Liu, Zhilian Li, Huaban Liang, et al. "Caspase-11 Mediates Pyroptosis of Tubular Epithelial Cells and Septic Acute Kidney Injury." Kidney and Blood Pressure Research 44, no. 4 (2019): 465–78. http://dx.doi.org/10.1159/000499685.

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Background/Aims: Acute kidney injury (AKI) is a serious complication of sepsis and has a high morbidity and mortality rate. Caspase-11 induces pyroptosis, a form of programmed cell death that plays a critical role in endotoxic shock, but its role in tubular epithelial cell death and whether it contributes to sepsis-associated AKI remains unknown. Methods: The caspase-11–/– mouse received an intraperitoneal injection of lipopolysaccharide (LPS, 40 mg/kg body weight). Caspase-11–/– renal tubular epithelial cells (RTECs) form C57BL caspase-11–/– mice were treated with LPS in vitro. The IL-1β ELISA kit and Scr assay kit were used to measure the level of interleukin-1β and serum creatinine. Annexin V-FITC assay and TUNEL staining assay were used to detect the cell death in different groups in vitro and in vivo. Western blot was performed to analyze the protein expression of caspase-11 and Gsdmdc1. Results: LPS-induced sepsis results in lytic death of RTECs, accompanied by increased expression of the pyroptosis-related proteins caspase-11 and Gsdmd. However, the increase in pyroptosis-related protein expression induced by LPS was attenuated with caspase-11 knockout, both in vitro and in vivo. Furthermore, when challenged with lethal doses of systemic LPS, pathologic abnormalities in renal structure, increased serum and kidney interleukin-1β, increased serum creatinine, and animal death were observed in wild-type mice but prevented in caspase-11–/– mice. Conclusions: Caspase-11-induced pyroptosis of RTECs is a key event during septic AKI, and targeting of caspase-11 in RTECs may serve as a novel therapeutic target in septic AKI.

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Schmiedeknecht, Kira, Andreas Kaufmann, Stefan Bauer, and Francisco Venegas Solis. "L-lactate as an indicator for cellular metabolic status: An easy and cost-effective colorimetric L-lactate assay." PLOS ONE 17, no. 7 (July 22, 2022): e0271818. http://dx.doi.org/10.1371/journal.pone.0271818.

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Background In recent times, the study of metabolic pathways has become inevitable and predominant for a variety of research fields as cancer biology and immunology. L-lactate as a product of anaerobic glycolysis has shown to be an important indicator of the cellular metabolic status and can be associated with diverse cellular effects. For this reason, L-lactate assay kits are of high demand when metabolic effects need to be considered. Nevertheless, commercially available kits are not affordable if multiple samples must be evaluated. Principal finding In this work, we develop an easy and cost-effective colorimetric assay for quantification of L-lactate suitable for cells with low or high L-lactate production based on LDH activity and suitable for 96 well-plate format. Using different metabolic regulators, we demonstrate the capacity of the assay to detect and quantify L-lactate from the supernatant of HeLa cancer cell line. Furthermore, we validate the assay against a commercially available kit by demonstrating no significant difference between both assays. Finally, we show that the assay is capable of quantifying L-lactate in primary cells such as hPBMCs that were stimulated with toll-like receptor ligands and treated with different metabolic regulators. Conclusion We herein present an easy custom assay that is suitable for cells with low and high L-lactate production at very low cost compared to commercially available kits. These advantages of the custom assay can simplify the research in the field of metabolism and related fields.

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Phromchaloem, C., and L. Muensritharam. "A simple paper-based biosensor for on-site visual detection of organophosphate residues." Research Journal of Chemistry and Environment 25, no. 12 (November 25, 2021): 82–87. http://dx.doi.org/10.25303/2512rjce8287.

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In general, the laboratory method of analyzing pesticides in vegetables is complicated due to the high cost of equipment and chemicals. The process of analyzing pesticide residues generally requires expertise as well as a significant period of time. In this study, a paper-based biosensor was developed for the detection of acetylcholinesterase (AChE) inhibitors, particularly organophosphate pesticides. The paperbased biosensor was constructed based on the Ellman colorimetric assay by immobilizing AChE on cellulose paper with 2% alginate gel, 0.25% glutaraldehyde and the colorimetric reagent 5,5-dithio-bis-(2-nitrobenzoic acid) (DTNB) in phosphate buffer (pH 8.0). As a substrate, acetylthiocholine chloride (ATChCl) was used. The results showed that the developed paperbased biosensor has been stable for 2 weeks with a detection limit of 0.03 mM of chlorpyrifos. The paper-based biosensor was applied to detect organophosphate pesticides in vegetables from the farmers’ market, Ratchaburi Province. It was found that the test results of the paper-based biosensor were similar to the commercial GT-test kit. The paper-based biosensor was 10 times faster than the GT-test kit in terms of testing time and the results were easy to identify due to the color-based indicator. As a result, a paper-based biosensor is rapid, portable and easy to use by the general population.

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AL-BAYATI, S. M. "BIOCHEMICAL PROFILE OF HYDATID CYST FLUIDS OF ECHINOCOCCUS GRANULOSUS OF SHEEP IN DUHOK AREA." Iraqi Journal of Veterinary Medicine 34, no. 1 (June 30, 2010): 185–90. http://dx.doi.org/10.30539/iraqijvm.v34i1.678.

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Twenty two ( 11 from lung and 11 from liver of lung-liver cross infection ) hydatid cysts fluid collected from sheep slaughter in Duhok abattoir and there biochemical analysis done for several parameters (total protein , Glucose, Cholesterol , triglyceride, creatinine , Urea , Uric acid , Calcium and Magnesium ions ) by colorimetric assay kits for the first time in this area . The biochemical parameters varies in there measures as for protein increased significantly ( P<0.01) in lung cysts fluid ,while in liver some increased significantly like cholesterol ( P<0.01) ,triglyceride ( P<0.05 ) , creatinine (P<0.01) , calcium (P <0.01) and magnesium ( P<0.05). In compare with previous studies the results reflected some differences for many values ,and also among lungs or livers , which may pointed some strain variability in parasite metabolism, growth rate or even strain variation

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Panteghini, M., F. Pagani, and R. Bonora. "Clinical and analytical evaluation of a continuous enzymatic method for measuring pancreatic lipase activity." Clinical Chemistry 39, no. 2 (February 1, 1993): 304–8. http://dx.doi.org/10.1093/clinchem/39.2.304.

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Abstract We report the evaluation of a new commercial kit for the determination of pancreatic lipase activity. The kit is based on the use of a 1,2-diglyceride as substrate and a specific monoglyceride lipase. The detection step is the continuous colorimetric measurement of hydrogen peroxide produced from glycerol by glycerol kinase, glycerol-3-phosphate oxidase, and peroxidase reactions. The procedure appears to be precise (between-day CV < 9%) and the results show good correlation with those obtained by alternative procedures (vs turbidimetry, r = 0.965; vs ultraviolet absorbance-enzymatic method, r = 0.995; vs Ektachem, r = 0.976; vs immunometry, r = 0.970). However, the method is susceptible to interference by increased concentrations (> 4.5 mmol/L) of serum triglycerides. We estimated the reference interval for healthy adults to be 8-44 U/L. When we evaluated clinical efficacy by using receiver-operating characteristic curves and the overlap index, no significant differences were found between the commercial kit and a common turbidimetric assay for diagnosing patients with acute pancreatitis; both methods performed satisfactorily.

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Alnahash, Abdullah, Young-Min Song, Sae-Kyung Min, Hyun-Jin Lee, Min-Ji Kim, Yoon-Hee Park, Je-Uk Park, and Jun-Beom Park. "Effects of Connective Tissue Growth Factor on the Cell Viability, Proliferation, Osteogenic Capacity and mRNA Expression of Stem Cell Spheroids." Applied Sciences 11, no. 14 (July 16, 2021): 6572. http://dx.doi.org/10.3390/app11146572.

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Background: Connective tissue growth factor (CTGF) is a cellular communication network factor family protein involved in many cellular functions. The purpose of this study was to determine the effects of CTGF on the proliferation, osteogenic capacity, and mRNA expression of spheroids composed of gingiva-derived mesenchymal stem cells (GMSCs). Methods: CTGF was applied at final concentrations of 0, 25, 50, 100, and 200 ng/mL. Qualitative cell viability was determined using Live/Dead kit assay. Metabolic viability was determined with a colorimetric assay kit. Osteogenic activity was analyzed with alkaline phosphatase activity and Alizarin Red S staining. Quantitative polymerase chain reaction (qPCR) was used to assess the expression levels of RUNX2, BSP, OCN, and COL1A1. Results: In general, there was no significant difference in cell viability between the groups on Days 1, 4, and 7. Addition of CTGF produced an increase in Alizarin Red S staining. qPCR results demonstrated that the mRNA expression levels of RUNX2, BSP, OCN, and COL1A1 were significantly increased with the addition of CTGF. Conclusions: Based on these findings, we conclude that CTGF can be applied for increased osteogenic differentiation of stem cell spheroids.

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Xu, Jianfeng, Wei Li, Shufen Xu, Weiyang Gao, and Zhenyu Yu. "Effect of dermatan sulphate on a C57-mouse model of pulmonary fibrosis." Journal of International Medical Research 47, no. 6 (April 21, 2019): 2655–65. http://dx.doi.org/10.1177/0300060519842048.

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Objective To test the antifibrotic effect of dermatan sulphate in a bleomycin-induced mouse model of pulmonary fibrosis. Methods C57 mice were randomly divided into four experimental groups: saline-treated control group, bleomycin-induced fibrosis group, prednisolone acetate group and dermatan sulphate group. Lungs were assessed using the lung index, and the extent of interstitial fibrosis was graded using histopathological observation of haematoxylin & eosin-stained lung tissue. Lung tissue hydroxyproline levels and blood fibrinogen levels were measured using a hydroxyproline colorimetric kit and the Clauss fibrinogen assay, respectively. Tissue-type plasminogen activator (tPA) was measured using a chromogenic tPA assay kit. Results Lung index values were significantly lower in the dermatan sulphate group versus the fibrosis group. Histopathological analyses revealed that dermatan sulphate treatment ameliorated the increased inflammatory cell infiltration, and attenuated the reduction in interstitial thickening, associated with bleomycin-induced fibrosis. Hydroxyproline and fibrinogen levels were decreased in the dermatan sulphate group versus the fibrosis model group. Dermatan sulphate treatment was associated with increased tPA levels versus controls and the fibrosis group. Conclusions Damage associated with bleomycin-induced pulmonary fibrosis was alleviated by dermatan sulphate.

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Faham, Shadab, Hamed Golmohammadi, Raouf Ghavami, and Gholamreza Khayatian. "A nanocellulose-based colorimetric assay kit for smartphone sensing of iron and iron-chelating deferoxamine drug in biofluids." Analytica Chimica Acta 1087 (December 2019): 104–12. http://dx.doi.org/10.1016/j.aca.2019.08.056.

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Canova-Davis, E., C. T. Redemann, Y. P. Vollmer, and V. T. Kung. "Use of a reversed-phase evaporation vesicle formulation for a homogeneous liposome immunoassay." Clinical Chemistry 32, no. 9 (September 1, 1986): 1687–91. http://dx.doi.org/10.1093/clinchem/32.9.1687.

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Abstract Complement-mediated release of enzyme molecules from reversed-phase evaporation vesicles serves as the basis of the sensitive homogeneous immunoassay reported here. We found it necessary to co-entrap the substrate glucose 6-phosphate with the bacterial enzyme glucose-6-phosphate dehydrogenase (EC 1.1.1.49) to protect enzyme activity during liposome preparation. Enzyme can be released specifically from these liposomes by incubation with antibody and complement. the enzyme is not merely available to substrate but is actually physically free of the liposomes. Inhibition of this complement-mediated lysis by theophylline is the basis for the homogeneous liposome immunoassay described. The assay results vary linearly with theophylline concentrations in plasma in the clinically relevant range, and serum components do not interfere. The reagents in the assay kit are stable for at least seven months when stored at 5 degrees C. No nontheophylline compounds reacted significantly with the antiserum used. The assay can be run in a kinetic format, with either ultraviolet or colorimetric detection.

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Mahmoudi, Tohid, Mohammad Pourhassan-Moghaddam, Behnaz Shirdel, Behzad Baradaran, Eden Morales-Narváez, and Hamed Golmohammadi. "On-Site Detection of Carcinoembryonic Antigen in Human Serum." Biosensors 11, no. 10 (October 14, 2021): 392. http://dx.doi.org/10.3390/bios11100392.

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Real-time connectivity and employment of sustainable materials empowers point-of-care diagnostics with the capability to send clinically relevant data to health care providers even in low-resource settings. In this study, we developed an advantageous kit for the on-site detection of carcinoembryonic antigen (CEA) in human serum. CEA sensing was performed using cellulose-based lateral flow strips, and colorimetric signals were read, processed, and measured using a smartphone-based system. The corresponding immunoreaction was reported by polydopamine-modified gold nanoparticles in order to boost the signal intensity and improve the surface blocking and signal-to-noise relationship, thereby enhancing detection sensitivity when compared with bare gold nanoparticles (up to 20-fold in terms of visual limit of detection). Such lateral flow strips showed a linear range from 0.05 to 50 ng/mL, with a visual limit of detection of 0.05 ng/mL and an assay time of 15 min. Twenty-six clinical samples were also tested using the proposed kit and compared with the gold standard of immunoassays (enzyme linked immunosorbent assay), demonstrating an excellent correlation (R = 0.99). This approach can potentially be utilized for the monitoring of cancer treatment, particularly at locations far from centralized laboratory facilities.

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Meléndez, Daniela M., Sonia Marti, Luigi Faucitano, Derek B. Haley, Timothy D. Schwinghamer, and Karen S. Schwartzkopf-Genswein. "Correlation between L-Lactate Concentrations in Beef Cattle, Obtained Using a Hand-Held Lactate Analyzer and a Lactate Assay Colorimetric Kit." Animals 11, no. 4 (March 25, 2021): 926. http://dx.doi.org/10.3390/ani11040926.

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Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer and a traditional lactate assay colorimetric kit. Blood samples were collected by venipuncture from 96 steers (Black or Red Angus × Hereford/Simmental and Black or Red Angus × Charolais; 247 ± 38.2 kg BW) prior to loading (LO1) and after 36 h of transport, and prior to reloading and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in the colorimetric analysis. Pearson correlations were calculated to assess the strength of the relationship between the experimental methods for the quantification of L-lactate concentrations. The magnitude and direction of the correlation, and the level of statistical significance varied over the observed time points, ranging from r = −0.03 (p = 0.75; LO1) to r = 0.75 (p < 0.0001; d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, p < 0.0001). Based on the low magnitude of the correlation due to variability across sampling time points in this study, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay (considered the gold standard) for measuring L-lactate in transported cattle.

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Yuan, Kaijing, Yao Sun, Fenchun Liang, Fenglan Pan, Miao Hu, Fei Hua, Yali Yuan, Jinfang Nie, and Yun Zhang. "Tyndall-effect-based colorimetric assay with colloidal silver nanoparticles for quantitative point-of-care detection of creatinine using a laser pointer pen and a smartphone." RSC Advances 12, no. 36 (2022): 23379–86. http://dx.doi.org/10.1039/d2ra03598g.

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This work describes a new nanosensor for one-step ultrasensitive naked-eye detection of creatinine based on the target-triggered aggregation of silver nanoparticles showing dramatically enhanced Tyndall effect.

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PUGGINA, ENRICO F., DALMO R. L. MACHADO, HUGO TOURINHO FILHO, and VALDIR J. BARBANTI. "Half-ironman induces changes in the kidney function of triathletes." Anais da Academia Brasileira de Ciências 86, no. 1 (March 2014): 429–36. http://dx.doi.org/10.1590/0001-37652014112912.

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Long duration exercise may lead to the occurrence of urine abnormalities. Aiming to investigate the effects of triathlon training and competition on the renal function, twelve male triathletes (32.60 ± 5.10 years, 175.04 ± 6.67m, 71.83 ± 7.42Kg) were studied during the 12-week training protocol and after a Half Ironman. Urine was collected in M-1 – beginning of the training season, M-2 – before the competition and M-3 – after the half ironman. Urine pH was measured using reagent strips, density with a refractometer, proteinuria by Bradford assay, creatinine with a colorimetric assay and blood cells by microscopy. Data were analyzed using Shapiro-Wilk test, One-Way ANOVA and Tukey-Kramer test (p < 0,05). Changes were found after the competition in the protein (M-1= 7.41 ± 2.48; M-2= 7.57 ± 3.74; M-3= 86.10 ± 76.21 mg/mL), creatinine (M-1= 157.66 ± 41.59; M-2= 177.68 ± 44.46; M-3= 316.46 ± 132.86 mg/mL), erythrocytes (M-1= 1060.00 ± 0.30; M-2= 1142.86 ± 377.96; M-3= 52555.56 ± 58.65 units/mL) and leucocytes (M-1= 2375.00 ± 744.02; M-2= 2090.00 ± 0.50; M-3= 5000.00 ± 2738.60 units/mL) excretion when compared to the other collection times. These effects are probably due to the exercise-induced modifications in the glomerular membrane and endocrine variables such as anti diuretic hormone, catecholamines and aldosterone.

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Batta, Dr Anil, Preeti Sharma, and Umesh Kumar. "Microalbuminuria, Serum Creatinine and Other Biomarkers among T2 DM Patients in North India." South Asian Research Journal of Applied Medical Sciences 4, no. 5 (September 6, 2022): 35–40. http://dx.doi.org/10.36346/sarjams.2022.v04i05.001.

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Background: Diabetic nephropathy (DN) is a common finding in diabetic patients. Microalbuminuria is the earliest clinical evidence of DN. Early detection of microalbuminuria is very important; it allows timely interventions to prevent progression to macroalbuminuria and later end-stage renal disease (ESRD). Objectives: To determine the prevalence of microalbuminuria in diabetic patients and establish its association with traditional serum renal markers in assessment of incipient nephropathy. Methods: This cross-sectional study involved 213 participants with diabetes mellitus (DM) attending the diabetic clinic of MM Institute of MSR. Aim: We aimed to evaluate the levels of urine microalbumin, urine albumin creatinine ratio, plasma creatinine and glycosylated hemoglobin (HbA1c) among type 2 diabetic patients and assessed the correlation between microalbuminuria and plasma creatinine levels. Questionnaires were used to obtain participant data after obtaining written informed consent. Data collected included: age, sex, level of education, history of smoking and alcohol consumption, hypertension, body mass index, family history, and duration of DM. Morning spot urine samples were collected from each participant and blood drawn for analysis of other renal markers. Urine microalbumin was determined quantitatively using immunoturbidity assay (Microalbumin kit, Mindray). Results: Increase in mean level of plasma creatinine (138 μmol/L), urine microalbuminuria (310 mg/L), albumin creatinine ratio (52) and HbA1c (7.9%) was observed among type 2 DM patients. Moderate positive correlation was observed between microalbuminuria and urine albumin creatinine ratio (r = 0.643 P = 0.0008) and between urine albumin creatinine ratio and plasma creatinine (r = 0.645 P = 0.032). Conclusion: We concluded that type 2 DM patients who are at risk of developing renal impairment must be regularly monitored for microalbuminuria, urine albumin creatinine ratio, and HbA1c levels.

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Mammadova, T. A. "BIOMARKERS OF EARLY DIAGNOSIS OF NECROTIZING ENTEROCOLITIS IN FULL-TERM INFANTS." Pediatria. Journal named after G.N. Speransky 100, no. 1 (February 15, 2021): 23–29. http://dx.doi.org/10.24110/0031-403x-2021-100-1-23-29.

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Objective of the research: to assess the value of new biomarkers – erythropoietin (EPO), nitric oxide (NO), calcium ion for the early diagnosis of necrotizing enterocolitis (NEC) in full-term newborns. Materials and methods: 100 full-term infants with NEC and 30 generally healthy infants (control group) were examined. In newborns of both groups in the first 2 weeks of life, plasma NO levels were determined by the colorimetric method (Caymans Nitrate/Nitrite Colorimetric Assay Kit) using an ELISYS UNO HUMAN; EPO – by Human Enzyme Immunoassay ELISA Kit, calcium ions – by a photometric test with BioScreen MS2000. Results: an increase in EPO levels and a decrease in Ca+2 level were revealed in patients depending on the NEC stage. In patients with stage I NEC, EPO and NO values increased by 54% and 46%, respectively, and the Ca+2 values were decreased by 19% in comparison with indicators in children of the control group. In patients with stage II NEC, EPO values increased by 70%, NO – by 124%, and Ca+2 were decreased by 61% compared to the indicators of children in the control group. In patients with stage III NEC, EPO values increased by 100%, NO – by 222% compared with the indicators of children in the control group. Conclusion: EPO, NO, and Ca+2 are biomarkers of early diagnosis of NEC in term infants and detection of severe variants of the disease.

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Chukwudi, Ijeoma Chekwube, Kenneth Ikejiofor Ogbu, Pam Dachung Luka, Refiloe Petunia Malesa, Livio Edward Heath, Emmanuel Ikenna Ugochukwu, and Kennedy Foinkfu Chah. "Comparison of colorimetric loop-mediated isothermal amplification kit and reverse transcription-polymerase chain reaction in the diagnosis of peste des petits ruminants in sheep and goats in Southeast Nigeria." November-2020 13, no. 11 (2020): 2358–63. http://dx.doi.org/10.14202/vetworld.2020.2358-2363.

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Background and Aim: Peste des petits ruminants (PPR) is an acute, extremely contagious transboundary viral disease of small ruminants with severe economic consequences, caused by PPR virus. Cost-effective and rapid diagnosis of the disease is essential for prompt management and control. This study aimed to compare the application of a commercial colorimetric loop-mediated isothermal amplification (cLAMP) kit and reverse transcriptase-polymerase chain reaction (RT-PCR) in the diagnosis of PPR in sheep and goats in Southeast Nigeria. Materials and Methods: Nasal swab samples were collected from West African Dwarf sheep and goats showing clinical signs suggestive of PPR (n=80) and those without any clinical signs (n=140) of the disease. The diagnosis was achieved through detection of PPR viral genome in the samples using a cLAMP kit and RT-PCR. cLAMP assay was done directly on nasal swab samples without ribosomal nucleic acid extraction. A set of six primers targeting the matrix gene protein was used for the cLAMP assay. Results: PPR viral genome was detected by both cLAMP and RT-PCR in 51 (63.8%) of the 80 samples from sheep and goats with signs suggestive of PPR while 14 (10%) of those without signs tested positive for PPR by both assay methods. There was a 100% agreement in the cLAMP and RT-PCR results. However, cLAMP was a faster, easier, and less expensive method compared to RT-PCR. Conclusion: The cLAMP assay demonstrates the potential for a point of care diagnosis in the field and a valuable diagnostic tool in areas with poor electricity supply as well as in a less equipped diagnostic laboratory. Since the reagents are affordable, cLAMP can be a diagnostic tool of choice in the detection and surveillance of PPR virus in countries with limited resources.

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Qiu, Yulou, Ajuan You, Xianshu Fu, Mingzhou Zhang, Haifeng Cui, Biao Zhang, Weiwei Qin, Zihong Ye, and Xiaoping Yu. "Quantum-Dot-Bead-Based Fluorescence-Linked Immunosorbent Assay for Sensitive Detection of Cry2A Toxin in Cereals Using Nanobodies." Foods 11, no. 18 (September 9, 2022): 2780. http://dx.doi.org/10.3390/foods11182780.

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In this study, a quantum-dot-bead (QB)-based fluorescence-linked immunosorbent assay (FLISA) using nanobodies was established for sensitive determination of the Cry2A toxin in cereal. QBs were used as the fluorescent probe and conjugated with a Cry2A polyclonal antibody. An anti-Cry2A nanobody P2 was expressed and used as the capture antibody. The results revealed that the low detection limit of the developed QB-FLISA was 0.41 ng/mL, which had a 19-times higher sensitivity than the traditional colorimetric ELISA. The proposed assay exhibited a high specificity for the Cry2A toxin, and it had no evident cross-reactions with other Cry toxins. The recoveries of Cry2A from the spiked cereal sample ranged from 86.6–117.3%, with a coefficient of variation lower than 9%. Moreover, sample analysis results of the QB-FLISA and commercial ELISA kit correlated well with each other. These results indicated that the developed QB-FLISA provides a potential approach for the sensitive determination of the Cry2A toxin in cereals.

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Mohammadi, Hamzeh, Somayeh Farhang Dehghan, Alireza Tahamtan, and Farideh Golbabaei. "Evaluation of potential biomarkers of exposure to crystalline silica: A case study in an insulator manufacturer." Toxicology and Industrial Health 34, no. 7 (May 7, 2018): 491–98. http://dx.doi.org/10.1177/0748233718770073.

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The purpose of this study was to examine the potential determinants of serum neopterin, malondialdehyde (MDA), and erythrocyte glutathione (GSH) as potential markers of oxidative stress, resulting in cellular immune response to inhaled silica particles. This descriptive analytical study was conducted on two groups of exposed workers ( n = 55) and unexposed office workers ( n = 38) of an insulator manufacturing plant. The sampling of airborne silica in the breathing zone of participants was done on the basis of the National Institute for Occupational Safety and Health Method 7601. The blood samples were analyzed by high performance liquid chromatography to determine the level of serum neopterin. A ZellBio GmbH assay kit was used for the quantitative assays of GSH and MDA on the basis of the colorimetric assay. The results of this study show that the measurements of serum neopterin, MDA, and GSH can be considered as potential biological markers of silica exposure for undertaking further comprehensive studies in this area.

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Jenny, R. W. "Interlaboratory evaluation of salicylate interference in colorimetric acetaminophen methods and its clinical significance." Clinical Chemistry 31, no. 7 (July 1, 1985): 1158–62. http://dx.doi.org/10.1093/clinchem/31.7.1158.

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Abstract Serum specimens with concentrations simulating an overdose of salicylate and acetaminophen were submitted to laboratories participating in an external quality-control program, to evaluate both the magnitude of salicylate interference in colorimetric acetaminophen methods and the clinical significance of the interference. The apparent acetaminophen concentration determined by nitration methods was increased by about 0.70 mg/L per milligram of salicylate per deciliter. Of those laboratories using nitration procedures, 25% do not routinely correct for salicylate and 66% use the (incorrect) correction factor provided by a kit manufacturer. Laboratory data, as they would have been reported to physicians, were used to estimate the acetaminophen half-life and were also applied to a nomogram used to assess the probability of hepatotoxicity. Interference by salicylate in the simulated overdose of 10 g (total dose) of each drug falsely indicated impending hepatic necrosis unless the appropriate correction factor was used. Laboratories using nitration procedures should screen samples submitted for acetaminophen assay for the presence of salicylate and, if present, either use a method specific for acetaminophen or utilize a correction factor determined in-house.

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Thorpe, G. H., I. Bronstein, L. J. Kricka, B. Edwards, and J. C. Voyta. "Chemiluminescent enzyme immunoassay of alpha-fetoprotein based on an adamantyl dioxetane phenyl phosphate substrate." Clinical Chemistry 35, no. 12 (December 1, 1989): 2319–21. http://dx.doi.org/10.1093/clinchem/35.12.2319.

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Abstract We have evaluated a new chemiluminescent substrate for the alkaline phosphatase (EC 3.1.3.1) label used in a Hybritech Tandem-E immunoassay of alpha-fetoprotein (AFP). The new substrate, adamantyl 1,2-dioxetane phenyl phosphate (AMPPD), emits light at 477 nm when acted upon by the enzyme. Detection limits for AFP with this method were 33 ng/L (mean of 20 replicates of the zero standard + 2 SD) and 470 ng/L (twice background). Between-batch CVs ranged from 4.31% to 9.60% for AFP in the range 29.1-132.0 micrograms/L. Comparison of results for 49 specimens assayed with use of the chemiluminescent kit and a colorimetric version of the AFP assay gave statistical values as follows: slope = 0.88, intercept = 4.19, and r = 0.94.

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Kaliberdenko, Vitalii B., Shanmugaraj Kulanthaivel, Michael V. Shterenshis, Olga Y. Poleshchuk, Kadri Mametov, Lutfie Mametova, and Keerthanaa Balasundaram. "Creatinuria and Dynamics of Calcium Metabolism in Children in the Phase of Exacerbation of Bronchial Asthma." Current Respiratory Medicine Reviews 16, no. 1 (September 15, 2020): 28–33. http://dx.doi.org/10.2174/1573398x16666200212102333.

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: Bronchial asthma is one of the most common and severe diseases among children. The phenomenon of creatinuria (CU) in patients with bronchial asthma (BA) has been acknowledged for a relatively long time. Aims: The Aim of the research is to study the level of creatinuria, creatinemia, creatine kinase activity, and the concentration of calcium in biological medium (blood, saliva, urine) in children suffering from an intermittent and persistent form of asthma during the period of exacerbation. Material and methods:: The research consists of 102 children with asthma who were treated in inpatient department in Simferopol Clinic. The intermittent course of asthma was recorded in 49 children and a persistent course of asthma was recorded in 53 children. The subject of study was blood serum and daily urine of observed patients. The level of calcium in the biological medium was studied using the "Filisit" test kit (Dnipro) and the activity of the creatine kinase by test set "Lahma". The levels of creatine and creatinine were determined using a colorimetric method based on a color reaction with picric acid. Results and conclusion: : The analysis testifies that creatinuria in children with persistent BA is caused by the disorder of the phosphorylation process rather than the disorder of creatinin rephosphorylation synthesis, that is testified by the normal creatinine level. In children with persistent BA, there is а decrease of creatinine concentration in the blood serum and urine during the exacerbation period and early post exacerbation period. The low activity of creatinine kinase at the background of creatinine elimination is typical for the children in the phase of exacerbation of persistent form of BA, though its level remains to be sufficient for the synthesis of the necessary amount of creatinine phosphate. Conclusion: The processes of creatinuria and calciuria in children suffering from a persistent form of BA are interdependent, that is testified by the data of correlative analysis. In connection with this, it is possible to consider the change of calcium homeostasis in the pathogenesis of the disease as one of the causes of distributing the creatinine metabolism on the cellular level.

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Pungut, Nur Amira Solehah, Hazwani Mat Saad, Kae Shin Sim, and Kong Wai Tan. "A turn on fluorescent sensor for detecting Al3+ and colorimetric detection for Cu2+: Synthesis, cytotoxicity and on-site assay kit." Journal of Photochemistry and Photobiology A: Chemistry 414 (June 2021): 113290. http://dx.doi.org/10.1016/j.jphotochem.2021.113290.

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Huang, Xiaopeng, Yingjie Li, Jiahong Pan, Fushen Lu, Yaowen Chen, and Wenhua Gao. "Glutathione-Protected Hierarchical Colorimetric Response of Gold Nanoparticles: a Simple Assay for Creatinine Rapid Detection by Resonance Light Scattering Technique." Plasmonics 10, no. 5 (February 26, 2015): 1107–14. http://dx.doi.org/10.1007/s11468-015-9907-4.

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Natarajan, Satheesh, Maria C. DeRosa, Malay Ilesh Shah, and Joseph Jayaraj. "Development and Evaluation of a Quantitative Fluorescent Lateral Flow Immunoassay for Cystatin-C, a Renal Dysfunction Biomarker." Sensors 21, no. 9 (May 3, 2021): 3178. http://dx.doi.org/10.3390/s21093178.

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The diagnosis, prognosis, and control of chronic kidney disease rely on an understanding of the glomerular filtration rate (GFR). The renal clearance of the cystatin-C is closely associated with the GFR. Cystatin-C is a more suitable GFR marker than the commonly used creatinine. General techniques for cystatin-C calculation, such as particle-enhanced turbidimetric and nephelometric assay, are time-consuming and tedious. Here, we propose a rapid, quantitative immunoassay for the detection of cystatin-C. A fluorescence-based lateral-flow kit was developed in a sandwich format by using a monoclonal antibody. A Linear calibration was obtained over the clinical diagnostic range of 0.023–32 µg/mL and the limit of detection (LOD) was 0.023 µg/mL and the limit of quantification (LOQ) was 0.029 µg/mL. Average recoveries from spiked urine samples ranged from 96–100% and the coefficient of variation was less than 4% for both intra and inter-day assays with excellent repeatability. With the comparison with an ELISA kit, the developed kit is highly sensitive, performs well over the detection range, provides repeatable results in a short time, and can easily be used at point-of-care (POC), making it an ideal candidate for rapid testing in early detection, community screening for renal function disorders.

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Sakai, T., K. Yamamoto, H. Yokota, K. Hakozaki-Usui, F. Hino, and I. Kato. "Rapid, simple enzymatic assay of free L-fucose in serum and urine, and its use as a marker for cancer, cirrhosis, and gastric ulcers." Clinical Chemistry 36, no. 3 (March 1, 1990): 474–76. http://dx.doi.org/10.1093/clinchem/36.3.474.

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Abstract We devised a kit for use with automated analyzers, for assay of urinary free L-fucose by means of a newly isolated L-fucose dehydrogenase (EC 1.1.1.122), and we measured L-fucose in healthy subjects, cancer patients, and patients with other diseases. It takes 10 min to complete one assay. Absorbance and L-fucose concentration were linearly related up to at least 3.0 mmol/L, analytical recovery was 90-104%, and intra- and interassay coefficients of variation were less than 4.2% and 7.8%, respectively. The concentrations of L-fucose, corrected for creatinine, were significantly higher than those in healthy subjects in nine of 18 patients with gastric ulcers, 19 of 21 patients with cirrhosis of the liver, and 206 of 366 patients with some type of cancer, reflecting a changed L-fucose metabolism. Because urine specimens are analyzed and the test is rapid and inexpensive, this method may be suitable for mass screening for some kinds of cancer, cirrhosis, and gastric ulcers.

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Bhadarka, Nagajan, Krutika Poddar, and Satyam Joshi. "Utilization of urine protein/creatinine ratio in pregnancy for diagnosis of preeclampsia." International Journal of Reproduction, Contraception, Obstetrics and Gynecology 7, no. 9 (August 27, 2018): 3646. http://dx.doi.org/10.18203/2320-1770.ijrcog20183769.

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Background: The aim of the present study was to evaluate the ability of the random urine P/C ratio to predict significant proteinuria, as well as to introduce a diagnostic test for preeclampsia that would avoid the inconvenience and time consumption of 24-hour urine protein collection.Methods: A total of 100 women who were pregnant were included in the study. For urine test, the urine was collected for 24 hours. The women patients provided the mid stream urine sample prior to the collection period. Biuret colorimetric assay was used to determine the total protein in the urine and the creatinine concentration was measured with the help of modified Jaff test.Results: The mean urinary protein excretion in 24 hour urine collection was found to be 2.05±0.74 g/dl and the median serum creatinine concentration was found to be 0.82 mg/dl. The mean p/c ratio was found to be 1.94±0.83. The correlation coefficient for the p/c ratio against the 24 hour urine protein excretion was found to be 0.88.Conclusions: This test can also be used as a reasonable alternative to 24-hour urine protein excretion, especially in emergency situations, and, it could also complement the urinary dipstick test in preeclamptic pregnancy.

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Dhaka, Gargi, Gitanjali Jindal, Ranjeet Kaur, Shweta Rana, Akhil Gupta, and Navneet Kaur. "Multianalyte azo dye as an on-site assay kit for colorimetric detection of Hg2+ions and electrochemical sensing of Zn2+ ions." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 229 (March 2020): 117869. http://dx.doi.org/10.1016/j.saa.2019.117869.

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Okabayashi, T., K. Takeda, M. Kawada, Y. Kubo, S. Nakamura, K. Chikamori, N. Terao, and K. Hashimoto. "Free thyroxine concentrations in serum measured by equilibrium dialysis in chronic renal failure." Clinical Chemistry 42, no. 10 (October 1, 1996): 1616–20. http://dx.doi.org/10.1093/clinchem/42.10.1616.

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Abstract The serum concentration of free thyroxine (FT4) is often low in patients with chronic renal failure (CRF) with low serum concentrations of triiodothyronine (T3). We evaluated the serum FT4 concentration by using both an equilibrium dialysis RIA kit (D-FT4) and a labeled-antibody kit (M-FT4) in two different groups of CRF patients, undergoing chronic hemodialysis (HD, n = 145) or not (non-HD, n = 30), and in a group of normal healthy subjects (n = 58). Thyroid peroxidase antibodies and thyroglobulin antibodies were not detected in any patient. Serum FT4 concentrations (mean +/- SD, pmol/L) by the D- and M-FT4 assays were, respectively, 21.5 +/- 4.6 and 16.6 +/- 2.0 in the healthy subjects, 17.8 +/- 4.3 and 13.9 +/- 3.6 in the non-HD patients, and 16.9 +/- 4.9 and 10.7 +/- 1.9 in the HD patients. By the D-FT4 assay, results for both CRF groups were significantly different from those for the healthy group (P <0.01), as were the results for each pair of groups by the M-FT4 assay (P <0.01). FT4 values were reported as being within the healthy reference range by D-FT4 in 73 of 113 HD subjects who had low T3 and low M-FT4 values. Serum FT4 concentrations measured by both assay kits showed a significant inverse correlation with the serum concentration of creatinine (P <0.01), but the serum concentrations of sex-hormone-binding globulin did not differ significantly among the three groups. Our results indicate that the low FT4 concentration measured by D-FT4 in patients with CRF, particularly those on HD, probably reflects the actual, mild nonthyroidal illness of renal failure.

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Journal articles on the topic 'Creatinine Colorimetric Assay Kit'

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