Simple and robust ICP-MS method for simultaneous determination of serum Co and Cr in routine clinical practice

Structural and biochemical characterisation of Co2+-binding sites on serum albumins and their interplay with fatty acids

Serum albumin-Co²⁺ interactions are of clinical importance. They play a role in mediating the physiological effects associated with cobalt toxicity and are central to the albumin cobalt binding (ACB) assay for diagnosis of myocardial ischemia. To further understand these processes, a deeper understanding of albumin-Co²⁺ interactions is required. Here, we present the first crystallographic structures of human serum albumin (HSA; three structures) and equine serum albumin (ESA; one structure) in complex with Co²⁺. Amongst a total of sixteen sites bearing a cobalt ion across the structures, two locations were prominent, and they relate to metal-binding sites A and B. Site-directed mutagenesis and isothermal titration calorimetry (ITC) were employed to characterise sites on HSA. The results indicate that His9 and His67 contribute to the primary (putatively corresponding to site B) and secondary Co²⁺-binding sites (site A), respectively. The presence of additional multiple weak-affinity Co²⁺ binding sites on HSA was also supported by ITC studies. Furthermore, addition of 5 molar equivalents of the non-esterified fatty acid palmitate (C16:0) reduced the Co²⁺-binding affinity at both sites A and B. The presence of bound myristate (C14:0) in the HSA crystal structures provided insight into the fatty acid-mediated structural changes that diminish the affinity of the protein toward Co²⁺. Together, these data provide further support for the idea that ischemia-modified albumin corresponds to albumin with excessive fatty-acid loading. Collectively, our findings provide a comprehensive understanding of the molecular underpinnings governing Co²⁺ binding to serum albumin.

Patients Following Revision Total Hip Arthroplasty With Modular Dual Mobility Components and Cobalt-Chromium Inner Metal Head are at Risk of Increased Serum Metal Ion Levels

BACKGROUND

Modular dual-mobility (MDM) total hip arthroplasty (THA) is designed with a cobalt-chromium liner inserted into a titanium acetabular component. The purpose of this study is to investigate the potential risks for fretting corrosion at this junction, by measuring serum metal ions, after MDM acetabular revision.

METHODS

Thirty-seven patients with well-functioning revision THAs participated in a cross-sectional study at mean 5.1 (2-10) years after surgery. All received a trabecular titanium MDM acetabular component. The serum levels of cobalt and chromium were measured using mass spectrometry.

RESULTS

The mean values of chromium and cobalt were 2.08 μg/L (95% confidence interval 0.9-3.2, range 0.02-11.8) and 1.99 μg/L (95% confidence interval 0.81-3.17, range 0.07-16.05), respectively. Eleven patients (29, 7%) had ion levels above the normal range, with 6 (16.2%) above 5 μg/L and 5 (13.5%) between 1 and 5 μg/L. A significant correlation was found between an elevated serum metal ion level and University of California Los Angeles score (P = .016).

CONCLUSION

We conclude that serum metal level elevation may occur secondary to metal debris resulting from corrosion of the index MDM THA. This potential risk should be included in the decision-making process when dealing with revision arthroplasty in young and active patients.

Reference values for trace essential elements in the whole blood and serum samples of the adult Serbian population: significance of selenium deficiency

This study was aimed to determine reference values (RVs) for the manganese (Mn), copper (Cu), zinc (Zn), and selenium (Se) in the whole blood (B) and serum (S) samples of the Serbian population. Blood specimens were collected from healthy persons (n = 295; women/men ratio = 149/146; mean age: 42 ± 2 years). The RVs were calculated as lower limit (LL) and upper limit (UL) of the 95% confidence interval (CI) and were expressed as percentiles (P) in the range from P2.5 to P97.5. The influences of sex, age, and smoking habits on element profiles were considered. It was found that the contents of B-Cu and S-Cu were higher in women, while the contents of B-Zn and S-Zn were higher in men. Both trace elements were significantly increased in a group of persons above 40 when compared to a younger persons (≤ 40 years). According to smoking habits, increased content was found only for S-Mn in the nonsmoker's group (p < 0.05). Comparing our results to the results reported in other population groups worldwide, the Serbian population had significantly reduced content of Se in both types of samples. This finding could highlight the deficiency of Se in the investigated Serbian population and could contribute to the better understanding of the molecular basis for the increased incidence of thyroid and other diseases in which selenium plays a key role.

The content of toxic and essential elements in trabecular and cortical femoral neck: a correlation with whole blood samples

Pollution caused by heavy metals affects all forms of life. The aim of the study was to determine the content of toxic (Sr, Ni, Pb, V, Cd, U, Rb, As) and essential (Na, K, Ca, Mg, Zn, Cu, Se, Mn, Cr, Mo, Co) metals in the bone and whole blood samples, in regard to clinical means of long- and short-term exposure, respectively. For this purpose, the cortical and trabecular parts of femoral neck, as well as the blood samples, were collected to quantify bone-important metals by inductively coupled plasma (ICP)-based techniques. According to principal component analysis (PCA), the most influential metal discriminating blood samples was Cu, while all other quantified elements were present in higher amounts in the bones. Additionally, trabecular bones (TBs) could be characterized by higher content of Mo, Cr, V, Mn, Co, As, and Ni compared to cortical bones (CBs). Linear discrimination analysis (LDA) was successfully applied to distinguish trabecular bone from the cortical bone. Significant correlation between essential Ca and toxic Sr with other elements was found and discussed. This study provides novel data on the effects of metal pollutants on bone health hazards. The results obtained for investigating metals may serve as a baseline for further clinical investigations in the orthopedic fields.

Accurate, sensitive, and precise determination of cobalt in soil matrices by the combination of batch type gas-liquid separator-assisted photochemical vapor generation and atomic absorption spectrophotometry

Determination of cobalt at low concentrations is an important issue because of its potential harmful effects on human health. Although flame atomic absorbance spectrometry (FAAS) is a fast and cheap method, it has high detection limits compared to other methods due to low nebulizer efficiency. In this study, the sensitivity, accuracy, and precision of the conventional FAAS were tried to be improved for cobalt determination using a photochemical vapor generation (PVG) system equipped with a batch type gas-liquid separator (BTGLS). The system parameters including organic acid type and concentration, UV irradiation period, mixing type, atomizer temperature, carrier gas flow rate, and sample volume were optimized to improve the detection power. The limits of detection and quantification were found to be 8.7 and 28.9 μg L^-1, respectively. The low relative standard deviation results indicated high precision. Applicability and accuracy of the method to soil samples was determined by recovery studies and percent recoveries were obtained between 98.9-107.0%. Graphical abstract Please provide caption for the graphical abstract.PVG-BT-GLS-AAS system .

Determination of toxic and essential trace elements in serum of healthy and hypothyroid respondents by ICP-MS: A chemometric approach for discrimination of hypothyroidism

Inductively coupled plasma-mass spectrometry ((ICP-MS)) was used to determine three toxic (Ni, As, Cd) and six essential trace elements (Cr, Mn, Co, Cu, Zn, Se) in blood serum of patients with hypothyroidism (Hy group) and healthy people (control group), in order to set the experimental conditions for accurate determination of a unique profile of these elements in hypothyroidism. Method validation was performed with standard reference material of the serum by varying the sample treatment with both standard and collision mode for analysis of elements isotopes. Quadratic curvilinear functions with good performances of models and the lowest detection limits were obtained for ⁵²Cr, ⁶⁶Zn, ⁷⁵As, ¹¹²Cd in collision mode, and ⁵⁵Mn, ⁵⁹Co, ⁶⁰Ni, ⁶⁵Cu, ⁷⁸Se in standard mode. Treatment of serum samples with aqueous solution containing nitric acid, Triton X-100 and n-butanol gave the best results. Chemometric tools were applied for discrimination of patients with hypothyroidism. All nine elements discriminated Hy group of samples with almost the same discriminating power as indicated by their higher values for this group of patients. Statistically significant correlation (p < 0.01) was observed for several elements. Results indicated clear differences in element profile between Hy and control group and it could be used as a unique profile of hypothyroid state.

Potential presence of metals in patients treated with metal-metal coupling prostheses for hip arthroplasty at 7 and 10 years of follow-up

BACKGROUND

Beginning in 2008, metal-on-metal prostheses have been in the spotlight owing to much higher revision rates than expected. Adverse local tissue reactions have been well described in the literature as potential complications.

METHODS

Between 2012 and 2013, 13 patients with metal-on-metal total hip replacements were evaluated clinically and radiologically and with laboratory samples. The same tests were repeated between 2015 and 2016 on eight patients to assess any changes. In the laboratory assessment, we searched for chromium, cobalt, molybdenum, and nickel in blood and urine samples over 24 h.

RESULTS

Clinical assessment has shown good score in all patients except one. On a second examination, between 2015 and 2016, all patients obtained results similar to those obtained in the first assessment, except a patient, who reported a recent fall. In the radiological assessment between 2012 and 2013, results were optimal, apart from a case of aseptic mobilization. The patients reassessed 3 years after the first examination showed radiological results similar to those previously obtained, apart from a patient, who showed signals of mobilization. Metal levels found in their blood decreased in most cases after 3 years. Urine levels of nickel increased in five subjects, and chromium levels increased in four, but levels of cobalt and molybdenum decreased in four patients.

CONCLUSION

It could be hypothesized that the decreasing trend of metal ion levels is associated with a stable wear status. On the contrary, a progressive increase in metal ion levels must be considered as early proof of implant loosening.

Establishing human heart chromium, cobalt and vanadium concentrations by inductively coupled plasma mass spectrometry

OBJECTIVE

Chromium, cobalt, and vanadium are used in metallic joint prosthesis. Case studies have associated elevated heart tissue cobalt concentrations with myocardial injury. To document the long term heart metal ion concentrations, a validated inductively coupled plasma mass spectroscopy (ICP-MS) method was needed.

METHOD

The method utilized a closed-vessel microwave digestion system to digest the samples. An ICP-MS method utilizing Universal Cell Technology was used to determine our target analyte concentrations. Accuracy was verified using reference materials. Precision, sensitivity, recovery and linearity studies were performed. This method was used to establish a reference range for a non-implant containing cohort of 80 autopsy human heart tissues RESULTS: This method demonstrated an analytic measurement range of 0.5-100ng/mL for each element. Accuracy was within ±10% of target value for each element. Within-run precision for each element was below 20% CV. The chromium, vanadium and cobalt concentrations (mean±SD) were 0.1523±0.2157μg/g, 0.0094±0.0211μg/g and 0.1039±0.1305μg/g respectively in 80 non-implant containing human heart tissue samples.

CONCLUSIONS

This method provides acceptable recovery of the chromium, cobalt and vanadium in heart tissue; allowing assessment of the effects of metallic joint prosthesis on myocardial health.

Acid retardation method in analysis of strongly acidic solutions by inductively coupled plasma mass-spectrometry

Acid retardation on the sorbents as a technique for reduction of the acidity of the solutions prior to their analysis by inductively coupled plasma mass spectrometry was proposed and investigated. The proposed scheme provides substantial separation of the analytes and nitric acid, which allows direct introduction of the eluates in plasma without dilution. Two sorbents were examined - AV-17 anion-exchange resin and the Stirosorb 584 sorbent. Sorption and desorption of 38 elements on these sorbents were investigated. The efficiencies of the REEs' sorption on the anion-exchange and neutral sorbents were compared. The higher efficiency of the REEs and HNO3 separation was revealed for the neutral Stirosorb 584 sorbent. It was also found that most elements come out quantitatively of the column filled with the AV-17 resin after pumping 2-4mL of the solution. Wherein, the concentration of nitric acid decreased by 20 times. The anomalous behaviour of Ag, Pb, Th and U on the AV-17 resin was found. These analytes were eluted only after pumping 4 column volumes of deionized water. Na, K, Fe, Al and Li in concentrations within (50-1000mgL(-1)) range did not affect the recovery of REEs. The potential of ARM technique was demonstrate by the analysis of puriss. HNO3 and silverware. ARM enables to avoid dilution of highly acidic solutions prior to their introduction in ICP-MS.

Trace metal determination as it relates to metallosis of orthopaedic implants: Evolution and current status

In utilising metal surfaces that are in constant contact with each other, metal-on-metal (MoM) surgical implants present a unique challenge, in the sense that their necessity is accompanied by the potential risk of wear particle generation, metal ion release and subsequent patient toxicity. This is especially true of orthopaedic devices that are faulty and subject to failure, where the metal surfaces undergo atypical degradation and release even more unwanted byproducts, as was highlighted by the recent recall of orthopaedic surgical implants. The aim of this review is to examine the area of metallosis arising from the wear of MoM articulations in orthopaedic devices, including how the surgical procedures and detection methods have advanced to meet growing performance and analytical needs, respectively.

Serum Concentrations of Trace Elements in Patients with Tuberculosis and Its Association with Treatment Outcome

Deficiencies in essential trace elements are associated with impaired immunity in tuberculosis infection. However, the trace element concentrations in the serum of Korean patients with tuberculosis have not yet been investigated. This study aimed to compare the serum trace element concentrations of Korean adult patients with tuberculosis with noninfected controls and to assess the impact of serum trace element concentration on clinical outcome after antituberculosis treatment. The serum concentrations of four trace elements in 141 consecutively recruited patients with tuberculosis and 79 controls were analyzed by inductively coupled plasma-mass spectrometry. Demographic characteristics were also analyzed. Serum cobalt and copper concentrations were significantly higher in patients with tuberculosis compared with controls, while zinc and selenium concentrations were significantly lower (p < 0.01). Moreover, serum selenium and zinc concentrations were positively correlated (ρ = 0.41, p < 0.05). A high serum copper concentration was associated with a worse clinical outcome, as assessed after one month of antituberculosis therapy. Specifically, culture-positive patients had higher serum copper concentrations than culture-negative patients (p < 0.05). Patients with tuberculosis had altered serum trace element concentrations. Further research is needed to elucidate the roles of individual trace elements and to determine their clinical impact on patients with tuberculosis.