Trace Elements In Serum Samples Research Articles

Determination of copper and other trace elements in serum samples from patients with biliary tract cancers: prospective noninterventional nonrandomized clinical study protocol.

Biliary tract cancers (BTCs) are usually diagnosed at an advanced stage, when the disease is incurable. Currently used tumor biomarkers have limited diagnostic value for BTCs, so there is an urgent need for sensitive and specific biomarkers for their earlier diagnosis. Deregulation of the homeostasis of trace elements is involved in the carcinogenesis of different cancers, including BTCs. The objective of the study is to determine/compare the total concentrations of copper (Cu), zinc (Zn) and iron (Fe) and the proportions of free Cu and Cu bound to ceruloplasmin (Cp) and the isotopic ratio of 65Cu/63Cu in serum samples from healthy volunteers and cancer patients using inductively coupled plasma-mass spectrometry-based methods (ICP-MS). In this prospective, noninterventional, nonrandomized study 20 patients and 20 healthy volunteers will be enrolled to identify serum Cu, Zn and Fe levels, Cu isotopic fractionation as a predictive biomarker of response to systemic therapy of BTCs, which will be evaluated by computed tomography. Newly developed analytical methods based on ICP-MS will be applied to metal-based biomarker research in oncology. In the study the comparison of the total concentration of selected trace elements, the proportion of free Cu and Cu bound to Cp and the isotopic ratio of 65Cu/63Cu in serum samples from healthy volunteers and cancer patients will be conducted to provide the foundation for the development of a BTC cancer screening methodology and the data on their usability as a potential predictive biomarker for BTCs of response to systemic therapy.

Development of a diagnostic model focusing on nutritional indicators for frailty classification in people with chronic heart failure.

Frailty has a great impact on the quality of life of patients with chronic heart failure (CHF), which needs to be judged in time. To develop a diagnostic model based on nutritional indicators to judge the frailty status of patients with chronic heart failure (Frailty-CHF). In the data collection part of this study, questionnaire method and biomedical measurement method were adopted. The trace elements in serum samples were detected by high performance liquid chromatography, chemiluminescence, and inductively coupled plasma mass spectrometry. We used Excel for data consolidation, and then imported the data into R software for modelling. Lasso method was used for variable screening, and Logistics regression fitting model was used after variables were determined. The internal validation of the model was completed by Bootstrap re-sampling. A total of 123 patients were included in this study. After variables' screening, age, nutritional status-heart failure, New York Heart Association Functional Class (NYHA), micronutrients B12, Ca, folic acid, and Se were included in the model, the c statistic and Brier score of the original model were 0.9697 and 0.0685, respectively. After Bootstrap re-sampling adjustment, the c statistic and Brier score were 0.8503 and 0.1690. In this study, a diagnostic model of age, nutritional status-heart failure, NYHA, the micronutrients B12, Ca, folic acid, and Se was established. It could help healthcare professionals better identify the frailty status in patients with CHF.

Development of dried serum spot sampling techniques for the assessment of trace elements in serum samples by LA-ICP-MS

A novel approach for serum analysis by dried matrix spot (DMS) technique is proposed. The methodology consists of sampling filter paper discs (2.7 mm in diameter) containing the large amount of serum retained after a single spotting. Several oxidizers (sodium chlorate, sodium azide, acetic acid, formic acid, 1-butyl-3-methylimidazoliumm chloride/bromide) were tested (oxidizers premixed with the sample before spotting, and papers previously soaked in concentrated additive/oxidizer solutions). Direct multi-element determination (Al, Be, Ca, Cu, Fe, K, Li, Mg, Mn, Mo, Na, P, Rb, Se, V, and Zn) in dried serum spots at very low levels was therefore assessed by laser ablation (LA) coupled with inductively coupled plasma - mass spectrometry (ICP-MS). Laser ablation was performed using a focused Nd: YAG laser beam in lineal scan mode (wavelength 213 nm, laser fluency 2.2 J cm−2, repetition rate 20 Hz, laser spot diameter 90 µm, depth 0 µm, scanning speed 12 µm s−1). Matrix-matched calibration mode and 13C as internal standard (for signal intensities normalization) was used throughout the work. Limits of quantification were found to be from 21 µg L−1 to 221 mg L−1. Repeatability (seven ablations of the same dried serum spot) and reproducibility (two ablations of seven dried serum spot from the same material) offered RSDs below 12% for all analytes, which seems satisfactory for clinical purposes. The method was validated by analyzing several certified reference materials (Seronorm™ level I and II trace elements in serum), and it was applied to several DMS from serum samples from healthy adults.

Trace Elements in Serum Samples of Patients with Multiple Sclerosis

Trace Elements in Serum Samples of Patients with Multiple Sclerosis

Determination and pattern recognition of trace elements in serum samples from patients with renal cell carcinoma by ICP-MS

Objective To study the relationship between serum trace elements and renal cell carcinoma.Methods The serum concentrations of multi-elements in 34 patients with renal cell carcinoma and 28 healthy volunteers were determined by inductively coupled plasma mass spectrometry(ICP-MS).The results were analyzed by partial least square discriminant analysis (PLS-DA) and Fisher discriminant.Results Compared with healthy voluteers,the levels of vanadium (5 034.56 ng/L:4 401.23 ng/L ),cobalt (211.34 ng/L:158.67 ng/L),nickel(l 850.55 ng/L:1 587.12 ng/L),manganese(1 873.35 ng/L:932.68 ng/L) and cadmium(95.63 ng/L:36.43 ng/L) were significantly higher in patients with renal cell carcinoma (P ＜ 0.05 ).While,the concentrations of calcium( 10.83 mg/L:11.78 mg/L) and zinc(67.11 μg/L:70.92 pg/L)were significantly lower ( P ＜ 0.05 ).Discriminant analysis showed that the serum elements levels in the patients with renal cell carcinoma were significantly different from the healthy volunteers.The scores plot showed distinct clustering between patients and controls,the points of patients were obviously offset from the controls.The classification accuracy of Fisher discriminant function was 97.61％.Conclusion Trace elements in serum are significantly different in patients with renal cell carcinoma and healthy volunteers.Discriminant analysis of serum samples based on trace element levels is possible.Thus,it is feasible for early diagnosis of renal cell carcinoma by determination of trace elements and discriminant analysis. Key words: Kidney neoplasms; Mass spectrometry; Trace elements; Discriminant analysis

Altered Copper Level and Renal Dysfunction in Nigerian Women Using Skin-Whitening Agents

The purpose of the study was to determine the concentration of trace elements in serum samples of women who are chronic users of skin-whitening agents as well as the hepatic and renal effects of these agents on these women. The study was conducted among 23 skin-whitening users while 25 women served as the controls. The serum concentrations of Zn, Mn, and Mg were not significantly changed in these women compared with controls (p > 0.05), but Cu was significantly increased in skin-whitening agent users compared with controls (p < 0.05). Serum urea and creatinine were significantly increased compared with the controls (p < 0.05). Moreover, ALT, AST, albumin, total protein, and bilirubin were not significantly changed (p > 0.05). The significant increase in the levels of renal indices shows that these agents might be nephrotoxic after prolonged usage while increase in copper level with accompanying renal dysfunction may be an indication that copper mediates in oxidative-induced renal dysfunction. However, further study is needed to identify the cause and source of high serum copper as many of the herbal extracts may be rich sources of copper. Moreover, a large population study may be necessary to examine the exact correlation between copper and renal indices.

Determination of trace elements in serum samples by isotope dilution inductively coupled plasma mass spectrometry using on-line dialysis

An on-line dialysis flow system coupled to inductively coupled plasma mass spectrometry to determine trace elements in serum samples by isotope dilution is presented. Isotope dilution was performed on samples incubated with enriched 65Cu, 66Zn, 77Se and 206Pb for 24 h at 36 °C prior to dialysis to quantified total element concentrations. The sample and acceptor solutions flowed through the dialysis unit with cellophane membrane placed in between the compartments. The serum sample (1 mL) was left to recycle in a closed path while the acceptor solution was continuously pumped along the dialyzer channel and through a cationic AG50W X-8 resin column. After 10 min, around 70% of Na, K and Cl migrate from the sample. Three replicate injections of 0.1 mL were performed for the clean sample after each separation step. The on-line coupling of the dialyzer to ICP-MS allowed isotope dilution for total element determination either in the cleaned sample or by eluting the cations retained in the resin to be carried out. Results demonstrated no matrix effects from alkaline elements or spectral interference from ArNa+ on 63Cu, ArCl+ on 77Se and 34SO2+ on 66Zn. The precision of isotope ratio measurements for Cu and Zn was around 1% and for Se and Pb was around 2.5%. The values found for the reference serum sample IMEP-17 were in good agreement with the certified values for Cu, Zn and Se.

Direct Determination of Selenium and other Trace Elements in Serum Samples by ICP-MS

Selenium belongs to a group of trace elements of special interest in biological samples for clinical diagnosis. Selenium has antioxidizing functions and is essential for providing the organism with triiodothyronine produced from thyroxine. Among several analytical techniques used to determine the Se concentration in serum, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has been used in the past because of its high sensitivity. Interference problems originating from different ions on the major Se isotopes have been described to be a limiting factor for the direct determination of Se in these matrices. Standard addition calibration or isotope dilution is often required to overcome carbon-enhanced ionisation effects in biological sample matrices. In most cases, the typical serum sample volume which is available for the analysis is limited to 0.5 ml or less, making multiple sample preparation for standard addition calibration impractical. Isotope dilution requires enriched isotopes and substantial sample preparation. Furthermore, the approximate Se concentration in every sample has to be known to adjust the appropriate amount of spike to each sample. Matrix matching with methanol has been described to overcome ionisation effects but we found limiting factors of this application when other trace elements are also determined within one sample run. This paper describes an effective sample preparation method which allows the direct determination of Se in serum without limiting the analytical capabilities for the additional determination of Al, Cu, Ni, Co, Cd, Mn and Zn in a single sample run by ICP-MS. Optimization procedures are presented and results of the analysis of reference samples are discussed, with a comparison of more than 150 serum data with those obtained by the GF-AAS method.

Multi-elemental trace analysis of human serum by double-focusing ICP-MS

A method is described for the determination of a selected range of trace and ultratrace elements in human serum, using a double-focusing ICP-MS instrument (ELEMENT, Finnigan-MAT). Serum samples were diluted 1+4 with ultrapure water and addition of Sc, Ga, Y and Tl as internal standards, to a final concentration of 10 µg L –1 , was used for matrix interference correction. Low and medium resolution scans were performed on the instrument for the analyses, the first scan, at m/Δm=300, for the determination of Rb, Sr, Mo, Cd, Pb and U and the second scan, at m/Δm=3000, for the determination of those elements subject to interference at low resolution: Al, Ca, Cr, Mn, Fe, Co, Cu, Zn and Se. A SRM, 1598 Inorganic Constituents in Bovine Serum (NIST), was analysed for validation of the multi-element analysis method. Good agreement was achieved between the found levels and the certified values. The method was also applied to the multi-analysis of trace elements in serum samples from healthy subjects and from uraemic patients. Preliminary experiments carried out with both quadrupole and double-focusing ICP-MS instruments proved to be invaluable for the study of spectral and non-spectral interferences in ICP-MS detection.