Continuous-flow serum albumin determination by reaction with picrate ions, with use of a flow-through picrate ion electrode.

1981 ◽  
Vol 27 (3) ◽  
pp. 427-430 ◽  
Author(s):  
E P Diamandis ◽  
D S Papastathopoulos ◽  
T P Hadjiioannou
Keyword(s):  
Serum Albumin ◽  
Continuous Flow ◽  
Peak Height ◽  
Ion Concentration ◽  
Screening Tests ◽  
Albumin Concentration ◽  
Serum Samples ◽  
Factors Affecting ◽  
Analytical Recovery ◽  
Flow Through

Abstract An automated potentiometric method for serum albumin determination by use of the picrate/albumin reaction is described. A continuous-flow system and a specially designed flow-through picrate ion electrode were used in making the measurements. Various factors affecting the reaction, such as pH, picrate ion concentration, and reaction time, were studied. Peak height in millivolts and albumin concentration were linearly related in the range 10-70 g/L. Both within-run and day-to-day, the CV for the method was about 2%. Analytical recovery of albumin added to serum samples ranged from 97.0 to 110.3%, averaging 102.2%. Results compare favorably with those by the established bromcresol green method. The proposed method is suitable for routine use and for screening tests.

scholarly journals Comparison Between Measured and Calculated Free Calcium Values at Different Serum Albumin Concentrations

2016 ◽  
Vol 8 (02) ◽  
pp. 071-076 ◽  
Author(s):  
Altaf Ahmad Mir ◽  
Bela Goyal ◽  
Sudip Kumar Datta ◽  
Saidaiah Ikkurthi ◽  
Arnab Pal
Keyword(s):  
Serum Albumin ◽  
Tertiary Care ◽  
Free Calcium ◽  
Albumin Concentration ◽  
Care Hospital ◽  
Serum Samples ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Clinical Biochemistry Laboratory ◽  
The One

ABSTRACT Introduction: Free ionic calcium is the metabolically active component of total calcium (TCa) in blood. However, most laboratories report TCa levels that are dependent on serum albumin concentration. Hence, several formulae have evolved to calculate free calcium levels from TCa after adjustment for albumin. However, free calcium can directly be measured using direct ion selective electrodes rather than spectrophotometric methods used in autoanalyzers. Objectives: This study compares the levels of free calcium obtained by measurement by direct ion selective electrode (ISE) and the one calculated as a function of TCa by formulae. Materials and Methods: A total of 254 serum samples submitted to clinical biochemistry laboratory of a tertiary care hospital were analyzed for total protein, albumin, and TCa by standard spectrophotometric methods and for free calcium by direct ISE. Three commonly used formulae viz. Orrell, Berry et al. and Payne et al. were used to calculate adjusted TCa. Calculated free calcium was obtained by taking 50% of these values. Results: A significant difference (P < 0.05) was observed between calculated free calcium by all the three formulae and measured free calcium estimated by direct ISE using paired t-test and Bland–Altman plots. Conclusion: Formulae for predicting free calcium by estimating TCa and albumin lacks consistency in prediction and free calcium should be evaluated by direct measurement.

Electroimmunoassay of albumin in human serum: accuracy and long-term precision.

1983 ◽  
Vol 29 (10) ◽  
pp. 1787-1790 ◽  
Author(s):  
M W Pascucci ◽  
D W Grisley ◽  
R N Rand
Keyword(s):  
Reference Method ◽  
Human Albumin ◽  
High Accuracy ◽  
Albumin Concentration ◽  
Agarose Gel ◽  
Factors Affecting ◽  
Analytical Recovery ◽  
Plate Formation ◽  
Sample Application

Abstract An improved procedure for the Laurell "rocket" technique is described. Samples were electrophoresed in an agarose gel containing anti-human albumin. The gel plates were processed, the peaks stained, and peak heights used to calculate albumin concentrations. Factors affecting precision were (a) adequate heating of agarose gel before antibody is added, (b) accurate leveling of the gel surface during plate formation, (c) applied voltage during sample application, and (d) avoidance of the "edge" effect on sample placement in the gel. Multi-plate long-term precision (CV) for the method was 6.2% at a mean albumin concentration of 13 g/L and 3.0% at 37 g/L. Analytical recovery of 8 and 11 g of albumin per liter was 99 to 100%. There was negligible interference from hemoglobin and dextran as well as several common substances that bind to albumin--bilirubin and salicylate. Because of its high accuracy and good long-term precision, the method is a possible candidate reference method for serum albumin.

Effect of albumin concentration on the assay of serum free thyroxin by equilibrium radioimmunoassay with labeled thyroxin analog (Amerlex Free T4).

1983 ◽  
Vol 29 (2) ◽  
pp. 321-325 ◽  
Author(s):  
N Amino ◽  
K Nishi ◽  
K Nakatani ◽  
H Mizuta ◽  
K Ichihara ◽  
...  
Keyword(s):  
Serum Albumin ◽  
Pregnant Women ◽  
Binding Proteins ◽  
Solid Phase ◽  
Albumin Concentration ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Free T4 ◽  
Serum Free

Abstract Serum free thyroxin (FT4) in normal nonpregnant and pregnant subjects was measured by radioimmunoassay (RIA) with Amerlex FT4 RIA (Amersham International) and LiquiSol FT4 RIA (Damon Diagnostics) kits. Amerlex FT4 values in serum from pregnant women were lower than those in serum from nonpregnant women, but LiquiSol FT4 values were similar in serum from both groups. Amerlex FT4 values were directly correlated with the concentrations of albumin in serum and inversely correlated with those of thyroxin-binding globulin, but not with prealbumin concentrations. No significant correlations were observed between LiquiSol FT4 values and serum concentrations of thyroxin-binding proteins. Amerlex FT4 values were normal in patients with excess, deficient, or decreased thyroxin-binding globulin. Albumin added to serum samples increased Amerlex FT4 values but not LiquiSol FT4 values. Albumin inhibited the binding of labeled thyroxin analog to the solid-phase thyroxin antibody. These data indicate that the albumin concentration influences FT4 values as measured by an RIA involving a thyroxin analog and that Amerlex FT4 values should be carefully interpreted when the patient has an abnormal concentration of serum albumin.

scholarly journals Prospective real-world study on the pharmacokinetics of pembrolizumab in patients with solid tumors

2021 ◽  
Vol 9 (6) ◽  
pp. e002344
Author(s):  
Daan P. Hurkmans ◽  
Sebastiaan D.T. Sassen ◽  
Karlijn de Joode ◽  
Lisanne Putter ◽  
Edwin A. Basak ◽  
...  
Keyword(s):  
Serum Albumin ◽  
Real World ◽  
Cell Cancer ◽  
Drug Clearance ◽  
Serum Lactate ◽  
Serum Lactate Dehydrogenase ◽  
Serum Samples ◽  
Factors Affecting ◽  
Serial Sampling ◽  
Advanced Stage Cancer

BackgroundDosing schemes of pembrolizumab (anti-programmed cell death protein 1 monoclonal antibody) are solely based on pharmacokinetic (PK) modelling derived from phase I–III trials. The current study aimed to determine factors affecting PK and its relationship with clinical outcome in the real-world setting.MethodsAdvanced-stage cancer patients, who were treated with pembrolizumab monotherapy (2 mg/kg Q3W or 200 mg flat Q3W), were prospectively included for serial sampling to obtain trough concentrations. A PK model was generated, covariate effects assessed and internally validated by a bootstrap procedure. PK parameters were related to overall survival (OS) and the occurrence of immune-related adverse events (irAEs).Results588 serum samples derived from 122 patients with (non-)small-cell lung cancer ([N]SCLC), malignant pleural mesothelioma (MPM), melanoma and urothelial cell cancer (UCC) were analyzed. Median follow-up was 2.2 years. A one-compartment PK model was generated: body surface area (BSA) and serum albumin had a significant effect on drug clearance (CL; covariate estimate 1.46 and −1.43, respectively), and serum lactate dehydrogenase (LDH) on the distribution volume(Vd; 0.34). A significant inverse CL–OS relationship was determined for NSCLC (HR:1.69; 95%CI1.07–2.68; p=0.024) and MPM (HR: 3.29; 95% CI 1.08 to 10.09; p=0.037), after correction for prognostic factors, which could not confirmed for melanoma (p=0.22) or UCC (p=0.34). No relationship could be determined between CL and grade >3 irAEs (p=0.70).ConclusionsHigh interpatient variability of pembrolizumab PK is determined by BSA and serum albumin (on CL) and LDH (on Vd). A strong inverse CL–OS relationship was demonstrated for NSCLC and MPM, which could not be observed for melanoma and UCC. The findings suggest that personalized dosing should be prospectively explored.

Total calcium and magnesium determined in serum with an automated stopped-flow analyzer.

1982 ◽  
Vol 28 (10) ◽  
pp. 2149-2152 ◽  
Author(s):  
M A Koupparis ◽  
E P Diamandis ◽  
H V Malmstadt
Keyword(s):  
Continuous Flow ◽  
Absorption Spectrometry ◽  
Stopped Flow ◽  
Tetraacetic Acid ◽  
Total Calcium ◽  
Serum Samples ◽  
Sample Throughput ◽  
Delay Response ◽  
Analytical Recovery ◽  
Calcium And Magnesium

Abstract We describe the measurement of total calcium and magnesium in serum with an automated microcomputer-controlled stopped-flow analyzer. The calcium method is based on the cresolphthalein complexone procedure, with 2-amino-3-methyl-1-propanol as the alkalinizing agent. The assay, performed on 60-fold prediluted samples, requires 50 microL of serum. Absorbance is measured at 580 nm for 1 s, after a 5-s delay. Response is linearly related to concentration up to 5 mmol/L; analytical recovery averaged 97.8%. Within-day CVs were 0.7 to 1.5%, day-to-day CVs 1.8 to 2.5%. Results compared well with those by continuous-flow Technicon SMA II method. A sample throughput of as many as 260 samples per hour is possible. The magnesium determination, a complexometric procedure, involves magnesium/calmagite complex in an alkaline reagent mixture and ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to eliminate calcium interference. Prediluted serum samples are used (100 microL of serum diluted 25-fold), and absorbance at 520 nm is linear with concentration to 50 mg/L. Within-run CVs were 0.5 to 1.1%, and day-to-day 1.3 to 3.8%; analytical recovery was 99.3%. Results compared well with those by atomic absorption spectrometry (r = 0.994). A delay time of 10 and a measurement time of 2.5 s allows for a throughput of as many as 180 samples per hour.

Clinical factors affecting cerebral oxygenation in patients undergoing peritoneal dialysis

2021 ◽  
pp. 039139882110200
Author(s):  
Taisuke Kitano ◽  
Kiyonori Ito ◽  
Susumu Ookawara ◽  
Taro Hoshino ◽  
Hideyuki Hayasaka ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Peritoneal Dialysis ◽  
Linear Regression ◽  
Serum Albumin ◽  
Cerebral Oxygenation ◽  
Linear Regression Analysis ◽  
Albumin Concentration ◽  
Healthy Controls ◽  
Serum Albumin Concentration ◽  
Factors Affecting

Background: Although cerebral regional oxygen saturation (rSO2) is significantly lower in hemodialysis (HD) patients than that in healthy controls, investigations on cerebral oxygenation in peritoneal dialysis (PD) patients are limited. We aimed to confirm the cerebral oxygenation status and identify the factors affecting cerebral rSO2 in PD patients. Methods: Thirty-six PD patients (21 men and 15 women; mean age, 62.8 ± 12.7 years) were recruited. In addition, 27 healthy volunteers (17 men and 10 women; mean age, 43.5 ± 18.8 years) were recruited as a control group. Cerebral rSO2 was monitored at the forehead using an INVOS 5100c oxygen saturation monitor. Results: Cerebral rSO2 was significantly lower in PD patients than that in healthy controls (57.0 ± 7.3% vs 68.9 ± 8.6%, p < 0.001); moreover, cerebral rSO2 was significantly correlated with natural logarithm (Ln)-PD duration ( r = −0.389, p = 0.019) and serum albumin concentration ( r = 0.370, p = 0.026) in a simple linear regression analysis. Multivariable linear regression analysis was performed using variables that showed a significant correlation and p < 0.20 (serum creatinine, serum sodium, Ln-C-reactive protein, and dosage of erythropoiesis-stimulating agent) with the cerebral rSO2. Cerebral rSO2 was independently associated with Ln-PD duration (standardized coefficient: −0.339) and serum albumin concentration (standardized coefficient: 0.316). Conclusions: Cerebral rSO2 was significantly affected by the PD duration and serum albumin concentration. Further prospective studies are needed to clarify whether preventing a decrease in serum albumin concentration leads to the maintenance of cerebral oxygenation in patients undergoing PD.

Serum Albumin Concentrations: Who Needs Them?

1992 ◽  
Vol 26 (9) ◽  
pp. 1134-1138 ◽  
Author(s):  
Brian L. Erstad
Keyword(s):  
Serum Albumin ◽  
Data Extraction ◽  
Institutional Setting ◽  
Albumin Concentration ◽  
Serum Albumin Concentration ◽  
General Applicability ◽  
Factors Affecting ◽  
Number Of Factors ◽  
Study Selection ◽  
Patient Prognosis

OBJECTIVE: To examine the multiple factors that influence serum albumin concentrations and to discuss settings in which the monitoring of such concentrations provides clinically useful information. DATA SOURCES: Original investigations, review articles, books, and abstracts published in English. STUDY SELECTION: Studies pertaining to factors affecting serum albumin concentration were chosen based on general applicability. Recommendations related to the appropriate monitoring of albumin concentrations were based on studies performed in the clinical setting with direct applicability to patient care. DATA EXTRACTION: Data on factors affecting serum albumin concentration were extracted from studies that resulted in similar conclusions regardless of assay technique. Appropriate indications for albumin monitoring were derived from studies demonstrating direct clinical relevance. DATA SYNTHESIS: A number of factors may influence serum albumin concentration and ultimately affect interpretation of the concentration. Serum albumin concentrations generally are useful in the institutional setting shortly after admission or preoperatively to determine patient prognosis. Albumin concentrations have limited merit for predicting the free fractions of various hormones, electrolytes, and drugs. When used as an indicator of nutritional support, albumin concentrations are most helpful when measured over longer periods in relatively stable patients. CONCLUSIONS: Serum albumin determinations should be limited to those situations in which the concentrations are likely to provide clinically useful information. Such situations are limited.

scholarly journals Spectroscopic Analysis of the Interaction between Bovine Serum Protein and Lead Ion

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiangqian Kong ◽  
Yingqing Liu ◽  
Yanhua Chen
Keyword(s):  
Infrared Spectroscopy ◽  
Bovine Serum Albumin ◽  
Fluorescence Spectroscopy ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Spectral Characteristics ◽  
Ion Concentration ◽  
Lead Ion ◽  
Albumin Concentration ◽  
Uv Spectrum

In this paper, the spectral characteristics of the interaction between lead and bovine serum albumin (BSA) were analyzed by fluorescence spectroscopy, ultraviolet spectroscopy and infrared spectroscopy. The effects of pH, bovine serum albumin concentration, lead ion concentration and ionic strength on the spectra of lead ion-bovine serum albumin system were investigated, and the best testing condition is to determine the interaction between lead and BSA by testing the peak changes or displacement in the UV spectrum analysis. Fluorescence spectroscopy showed that lead ion could induce the fluorescence quenching of bovine serum albumin. The influence of lead ion on the secondary structure of protein was analyzed by infrared spectroscopy. It was found that β-angle increased, α-helix decreased and β-slice increased.

scholarly journals State of Harmonization of 24 Serum Albumin Measurement Procedures and Implications for Medical Decisions

2017 ◽  
Vol 63 (3) ◽  
pp. 770-779 ◽  
Author(s):  
Lorin M Bachmann ◽  
Min Yu ◽  
James C Boyd ◽  
David E Bruns ◽  
W Greg Miller
Keyword(s):  
Serum Albumin ◽  
Renal Dialysis ◽  
Measurement Procedure ◽  
Albumin Concentration ◽  
Serum Samples ◽  
Medical Decisions ◽  
Immunochemical Method ◽  
Quality Of Patient Care ◽  
Heparin Plasma

Abstract BACKGROUND Measurements of serum and plasma albumin are widely used in medicine, including as indicators of quality of patient care in renal dialysis centers. METHODS Pools were prepared from residual patient serum (n = 50) and heparin plasma (n = 48) from patients without renal disease, and serum from patients with kidney failure before hemodialysis (n = 53). Albumin was measured in all samples and in ERM-DA470k/IFCC reference material (RM) by 3 immunochemical, 9 bromcresol green (BCG), and 12 bromcresol purple (BCP) methods. RESULTS Two of 3 immunochemical procedures, 5 of 9 BCG, and 10 of 12 BCP methods recovered the RM value within its uncertainty. One immunochemical and 3 BCG methods were biased vs the RM value. Random error components were small for all measurement procedures. The Tina-quant immunochemical method was chosen as the reference measurement procedure based on recovery and results of error analyses. Mean biases for BCG vs Tina-quant were 1.5% to 13.9% and were larger at lower albumin concentrations. BCP methods' mean biases were −5.4% to 1.2% irrespective of albumin concentration. Biases for plasma samples were generally higher than for serum samples for all method types. For most measurement procedures, biases were lower for serum from patients on hemodialysis vs patients without kidney disease. CONCLUSIONS Significant differences among immunochemical, BCG, and BCP methods compromise interpretation of serum albumin results. Guidelines and calculations for clinical management of kidney and other diseases must consider the method used for albumin measurement until harmonization can be achieved.

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