High Metal Ion Levels Research Articles

Formation of zinc carbonate phases on dissolving calcite, aragonite, and vaterite in acidic aqueous solutions

Calcium carbonate (CaCO3) minerals serve as a major sink to retain metal ions through mineral-water interfacial reactions in which the capacity and long-term stability of contaminant uptake are influenced by coupled dissolution and precipitation reactions of both primary and secondary carbonate minerals (i.e., mineral replacement). Notably, recent studies of calcite reactivity in acidic solutions containing high levels of metal ions demonstrated complex behavior under conditions of sustained disequilibrium. We explored the reactivity of three CaCO3 polymorphs (calcite, aragonite, and vaterite) with acidic Zn2+-containing aqueous solutions using a suite of imaging techniques including optical and scanning electron microscopies, synchrotron-based micro X-ray fluorescence, and transmission X-ray microscopy. Zn uptake by calcite occurred through a two-step process: the formation of a thin layer of the zinc precipitate on the substrate surface followed by the growth of fibrous and radiating hydrozincite particles from the layer. In contrast, Zn uptake by aragonite occurred by mineral replacement where the secondary Zn carbonate phase preserved the external morphology of the original crystal (i.e., a pseudomorph). The replacement of vaterite by hydrozincite occurred within the confined space beneath the porous shell of vaterite, signifying that the primary mechanism driving Zn carbonate precipitation was chemical exchange through the pores. When multiple CaCO3 polymorphs coexisted, the replacement of aragonite and vaterite occurred preferentially over that of calcite. These results demonstrate the distinct morphological and mineralogical controls over the reactivities of calcium carbonate minerals with Zn2+ under acidic conditions.

Influence of Physical Activity and Cup Orientation on Metal Ion Release and Oxidative Stress in Metal-on-Metal and Ceramic-on-Metal Total Hip Arthroplasty.

Metal-on-metal (M-M) total hip arthroplasty (THA) has shown adverse reactions to metal debris, abnormal soft-tissue reactions, and high blood metal ion levels. This study aims to: (1) assess whether the toxicity of high levels of ions is related to altered oxidative stress and (2) evaluate tribological factors related to increased blood levels of chromium (Cr) and cobalt (Co) ions. A cross-sectional analytical descriptive study was conducted on 75 patients. A total of 25 underwent M-M THA, 25 ceramic-on-metal (C-M) THA, and 25 were on the THA waiting list. Ion metallic levels in blood, oxidative stress, physical activity, and implant position were compared. In the M-M group, Co and Cr levels were significantly higher than those found in the C-M group and the control group (p < 0.01). We found no differences in terms of oxidative stress between the groups. Also, we did not find a correlation between metal blood levels and oxidative stress indicators, the physical activity of the patients or the position of the implants between groups. The use of M-M bearing surfaces in THA raises the levels of metals in the blood without modifying oxidative stress regardless of the physical activity levels of the patients. Therefore, although patients with M-M bearings require close monitoring, it does not seem necessary to recommend the restriction of physical activity in patients with M-M or C-M arthroplasties.

Two-Photon Fluorescent Probes for Amyloid-β Plaques Imaging In Vivo.

Amyloid-β (Aβ) peptide deposition, hyperphosphorylated tau proteins, reactive astrocytes, high levels of metal ions, and upregulated monoamine oxidases are considered to be the primary pathological markers of Alzheimer's disease (AD). Among them, Aβ peptide deposition or Aβ plaques, is regarded as the initial factor in the pathogenesis of AD and a critical pathological hallmark in AD. This review highlights recently Aβ-specific fluorescent probes for two-photon imaging of Aβ plaques in vivo. It includes the synthesis and detection mechanism of probes, as well as their application to two-photon imaging of Aβ plaques in vivo.

O113 ELEVATED METAL ION LEVELS CAN BE TOLERATED BY SOME PATIENTS

Abstract Introduction Ten years following withdrawal and revision of large diameter metal on metal hips (MOM), there remains an uncertainty in how best to manage asymptomatic patients with abnormal imaging and/or raised blood metal ion levels. This study investigates the trajectories of symptoms, serological metal ion tests and cross-sectional imaging in these patients. Methods 523 patients with 707 acceptable functioning MOM hips (defined as Oxford Hip Score (OHS) &amp;gt;30) on active monitoring were identified. Surveillance at two time intervals included: patient-reported pain and function (OHS), blood metal ion (Cobalt (Col) and Chromium (Chr)) and/or cross-sectional imaging with MRI. Results Mean serum metal ion levels in parts per billion (ppb) were Co1 4.5 (S.D. 11.5), Co2 4.7 (S.D. 11.6) and Ch1 3.0 (S.D. 4.8) and Ch2 3.2 (S.D. 4.9). Median OHS was 42 (IQR 28–27). OHS was not significantly correlated to serum metal ion levels (Col Pearson correlation = -0.105 P = 0.106, Chr Pearson correlation = -.125 P = 0.054). There was no significant change in Col (-0.48, P = 0.414) and Chr levels (-0.25, P = 0.325) between the two time intervals. 45 patients had metal ion levels &amp;gt;7 ppb, 64.4% had OHS &amp;gt;30. 6 patients had metal ions level greater than 50 ppb, with no significant deterioration of OHS. Conclusion Our results indicate that there are a subset of patients with high metal ion levels, stable imaging and acceptable function who can safely be actively monitored thereby assisting in joint decision making with this challenging patient group.

Treatment and prevention of pollutants in the wastewater from a scheelite and fluorite processing plant

Mineral processing wastewater contains high levels of chemical oxygen demand (COD), suspended solids (SS) and heavy metal ions, and its substandard discharge will pose a threat to the ecological environment and human health. In this study, a combined method of coagulation and Fenton oxidation was used to remove pollutants from scheelite and fluorite processing wastewater. The experimental results showed that the overall removal rates of COD, SS, Pb2+ and Zn2+ from the wastewater samples reached 88.41 %, 99.73 %, 99.09 % and 99.31 %, respectively, after stepwise treatment with poly ferric sulfate (PFS) coagulation and Fenton oxidation. The main contributors of COD in the wastewater samples were sodium oleate (NaOL) and benzohydroxamic acid (BHA). The maximum COD removal by PFS coagulation was >90 % for NaOL solution, but <45 % for BHA solution. The COD removal effect of Fenton process on NaOL solution was also better than that of BHA. This indicated that the removal effect of COD was not only related to the experimental conditions but also to the structure of organic compounds. Based on the above research, a monitoring and management system of pollutants was established, and the effective removal of pollutants was confirmed by industrial tests in a plant. This study provides a certain theoretical basis and technical support for the efficient treatment of mineral processing wastewater and is of great significance for the protection of the ecological environment around the mine.

A Mini-review on the Application of Chemically Modified Sensing Platforms for the Detection of Heavy Metal Ions in Water

Abstract: High levels of metallic ions, particularly heavy metals, can cause serious damage not only to public health but to the whole ecosystem. Therefore, rapid and precise detection and monitoring of heavy metals have become vital. The detection of heavy metals in water using conventional monitoring approaches based on physicochemical and analytical procedures, e.g., inductively coupled plasma combined with atomic absorption spectroscopy, X-ray fluorescence, instrumental neutron activation analysis, etc., has been immensely utilized. However, the sophisticated sample preparation and evaluation procedures for most of the mentioned methods are time- and labor-intensive, and economically more favorable detection approaches, e.g., sensors and lab-on-a-chip techniques, are being developed. Chemical sensors (electrochemical, optical, and piezogravimetric) with different sensing platforms (nanostructures, biological, polymeric, and macrocyclic) have been considered to be the most promising ones, owing to their strong adsorption of target elements, fast electron transfer kinetics, and biocompatibility, which are very apt for sensing applications. The combination of electrochemical, optical, and piezogravimetric techniques with nanomaterials has enhanced the sensitivity, limit of detection, and robustness of the chemosensors. Following this perspective, this review highlights surface modification platforms of sensors that enhance the detection properties (sensitivity, selectivity, limit of detection, and linear range) of the proposed devices, including nanostructures, biological networks, polymers, and macrocycles with a special emphasis on calixarenes/resorcinarenes oligomers. The capabilities, limitations, and prospect assessments of the covered techniques in detection and monitoring have been highlighted.

Optimisation of semi-upscaled polymer inclusion membrane (PIMs) based device for passive remediation of metal ions in acid mine drainage (AMD)

Acid mine drainage (AMD) has been a source of environmental contamination in many parts of the world. This is because many countries depend on mining as a source of revenue. However, waste tailing dumps often leach out toxic waste with high levels of metal ions and flow downstream to dams and rivers. The current remediation methods (passive and active) are expensive or ineffective for long-term use. In some cases, these methods generate solid slag waste as a major by-product. However, as part of the green and circular economy, waste materials are viewed as potential resources for raw materials. This work then reports on the design, laboratory optimisation and early-stage application of semi-pilot passive remediation device for the possible recovery of metal ions (cadmium, cobalt, copper, iron, and nickel) in AMD generated in the tailings pond. The sampling remediation device consisted of a polymer inclusion membrane composed of polyvinyl chloride and di-(2-ethylhexyl) phosphoric acid as a semi-penetrable barrier. The device had an upscaled chamber made of nylon with 1000 mL of the receiving solution. This developed passive remediation device was used in both synthetic and real AMD samples where a linear uptake of metals was demonstrated from day 6 to over a month with little influence of matrices. During deployment, the pH was increasing in the receiving solution and decreasing in the source solution of the linear region thus indicating the analytes facilitated transport. On day 35 of environmental application accumulated concentrations of target metal ions were Ni (63.42 mg L−1), Cd (47.48 mg L−1), Co (57.34 mg L−1), and Cu (49.86 mg L−1). Further, the characterisation results showed no signs of membrane degradation in this period. This highlights that the PIMs are a promising future for passive remediation and/or recovery of metal ions in mine wastewater before contamination of rivers and dams downstream.

Persistently Raised Serum Titanium Levels After Spinal Instrumentation in Children.

Prospective study of patients undergoing elective spinal deformity surgery with repeated testing for circulating metal ions including preoperative levels acting as controls. The aim was to determine if levels of particular circulating metal ions are maintained to two years postsurgery including different implant systems and rods. Adults having hip replacements, especially metal-on-metal bearings, may develop high metal ion levels. Pediatric spinal implants are known to cause circulating metal ions, notably titanium, chromium, cobalt, and nickel. Fifty-six children having spinal deformity surgery were studied with repeated testing for circulating metal ions, using high-resolution inductively coupled plasma mass spectrometry. Linear mixed-effects models adjusting for repeated measurements over time were used to analyze levels of titanium, cobalt, chromium, and nickel. Titanium levels showed a rapid increase by seven days and a peak at 30 days that was essentially maintained at the two-year assay. At two years, titanium levels were 5.14 times greater compared with the presurgery control level (P<0.0001). Cobalt levels were shown to gradually rise to a peak at 30 days and then slowly decline but remained 1.74 times above mean baseline level at two years (P=0.0004), with a declining trajectory. Chromium and nickel levels rose immediately postoperatively and then steadily declined to baseline by six months and remained at baseline at two years. The five implant systems tested had generally equivalent results. The persistent and rising levels of titanium, in a predominantly female population, is concerning. Titanium is known to cross the placental barrier and enter the circulation of the fetus in rodents and humans, and to accumulate in solid organs especially the liver, spleen, heart, and lymph nodes in humans. This potentially exposes the offspring of mothers with spinal implants to titanium, with potential teratogenic effects.

Light Irradiation Coupled with Exogenous Metal Ions to Enhance Exopolysaccharide Synthesis from Agaricus sinodeliciosus ZJU-TP-08 in Liquid Fermentation.

To promote Agaricus sinodeliciosus var. Chaidam ZJU-TP-08 growth and metabolites accumulation, a novel integrated strategy was developed by adopting high levels of metal ions coupled with light treatment. The results revealed that yellow and blue light could significantly promote biomass and exopolysaccharides production, respectively. Furthermore, the yellow–blue light shift strategy could stimulate exopolysaccharides formation. Ca2+ ions coupled with blue light mostly promoted exopolysaccharides production related to oxidative stress, which was 42.00% and 58.26% higher than that of Ca2+ ions coupled with the non-light and dark cultivation without Ca2+ ions in 5-L bioreactor. RNA-seq was performed to uncover the underlined molecular mechanism regulated by light-induced gene expressions in exopolysaccharides biosynthesis and oxidative stress. The findings of this work provide valuable insights into adopting metal ions coupled with the light-assisted method for the macrofungus submerged fermentation for exopolysaccharides production.

Course of Metal Ions after a Revision of Malfunctioning Metal-on-Metal Total Hip Prostheses.

The present research evaluated the course of cobalt and chromium in the blood and urine after the revision of metal-on-metal with a ceramic-on-polyethylene total hip arthroplasty. Seven patients were enrolled for hip prosthesis revision owing to ascertained damage of the implant. Metals in the blood and urine were evaluated before and after the hip revision. The double measurement before the total hip revision revealed high levels of metal ions (on average, 88.1 µg/L of cobalt in the blood, 399.0 µg/g of creatinine cobalt in the urine, 46.8 µg/L of chromium in the blood, and 129.6 µg/g of creatinine chromium in the urine at the first measurements), with an increasing trend between the first and second dosage. Within a week after the hip revision, the levels of metal ions significantly decreased by approximately half. Four to six months after the operation, the cobalt levels were found near to the reference values, whereas the chromium levels reached 25% of the values measured before the revision. The revision of malfunctioning metal-on-metal implants produced a dramatic decrease of metal ions in biological fluids, although it did not completely rescue the chromium level.

Catastrophic failure of femoral stem modular junction when combined with metal-on-metal bearing in comparison to ceramic-on-ceramic: A retrospective cohort study

BackgroundMetal ion release from total hip arthroplasty's (THA) metal-on-metal (MoM) bearing surfaces or head-neck modular junction (trunnionosis) has been identified as a major cause of adverse reaction to metal debris (ARMD). No study has compared the effects of these bearing couples when combined with modular neck femoral stems (MNFS) (i.e. did a modular CoCr have a higher effect than large MoM bearings on whole blood ion concentrations and ARMD). Therefore we did a retrospective comparative analysis of prospectively collected data aiming to: (1) assess the difference in metal ion release between a group of MoM and CoC bearings implanted with a non-cemented MNFS; (2) compare the ARMD and the related revision rates between the two bearing types; (3) compare the patients’ HOOS and Harris Hip scores. HypothesisMetal ion levels and complications rate will be higher in MoM group. MethodsThirty hips received the same short MNFS with modular CoCr. Seventeen had CoC bearing (16=36mm) and 13 large diameter head (LDH) MoM bearing (mean=50mm, 44-54mm) Both groups had whole blood Cobalt (Co) and Chromium (Cr) concentrations measurements at last follow up or before revision surgery (if any) and were compared to 41 control individuals without implants. ARMD, revision rates and other complications were censed. Functional outcome differences between operative groups were assessed with HOOS and Harris Hip scores. ResultsMean whole blood Co and Cr were 1.9μg/L (0.1–10.6 min–max) and 1.2μg/L (0.2–4.6 min–max) in the CoC group and 12.7μg/L (2.5–40.7 min–max) and 8.2μg/L (2.8–40.6 min–max) for MoM group. Controls presented whole blood Co and Cr levels of 0.2μg/L (0.04–0.2 min–max) and 0.6μg/L (0.1–0.7 min–max) respectively. CoC had significantly higher whole blood metal ion concentrations than controls, while MoM had significantly higher concentrations than both (p<0.001). MoM had a 9/13 (69%) revision rate due to ARMD (with stem-neck junction corrosion and wear were present in all cases) while the CoC had none. Functional scores at last follow up did not statistically differ between groups (Harris: CoC=94.1±8.4 vs MoM 91.8±14.8 (p=0.22) and CoC HOOS 90.2±10.7 vs 75.6±21.7 (p=0.08)). ConclusionIn our study, MNFS with CoCr modular neck released metal ion systemically, as shown in CoC THAs, but when combined with MoM LDH bearings, that elevation was significantly higher. In MNFS MoM, these high metal ion levels translated into a dramatic ARMD related revision rate where stem-neck junction corrosion and wear were present in all cases. More research is required to understand the effects of MoM bearing on neck-stem junctions, and its mechanisms of corrosion. Level of evidenceIII; retrospective comparative study.

Effect of Boron Doping Level on BDD Electrode for Heavy Metal Ion Sensor

Recently, industrial wastewater is being discharged in large quantities due to the development of industry and this wastewater contains a various heavy metal ion. Exposure to high levels of trace metal ions [Cd (II), Pb (II), Cu (II)] causes a variety of health and environmental problems. These toxic species accumulated in the human body through the water source have a low rate of clearance. [1,2]To minimize the exposure of humans to these contaminants through effective water quality monitoring, anode stripping voltammetry (ASV) method was used. ASV method has wide linear dynamic range, low detection limit (ppb), multi-element analysis capability and the simplicity of the instrumentation, which is relatively inexpensive and small in size, requires low levels of electrical power and is sufficiently portable to permit its use in the field. So, ASV has been used successfully for the determination of heavy metals in water. The sensitivity of differential pulse anode stripping voltammetry (DPASV) is higher than other classical voltammetry, because of its enhanced faradaic current and decreased non-faradaic charging current. [2]In generally, Ir, Au, Ag and Hg electrodes have been used for stripping analysis of trace metals, but the Ir, Au, Ag electrodes have low sensitivity, Hg electrode have toxicity and volatility. [2] To solve this drawbacks, we fabricate a Boron-doped diamond (BDD) electrodes. BDD electrodes are candidate for use in the detection of a trace heavy metal ions, because these show good electrical conductivity, low background current, and non-toxicity.In this study, BDD electrodes on Si substrate deposited by hot filament chemical vapour deposition (HFCVD) and applied to DPASV measurement. Through the optimization of the deposition condition of BDD electrodes and measurement condition of DPASV, we increased the detection sensitivity of heavy metal ions. The BDD electrode with the optimum boron doping concentration by controlling the boron doping concentration from 100 to 10000 ppm in the deposition process optimization step has excellent durability and selectivity of heavy metal ions. As a result of electrochemical measurement, BDD electrode with 8000 ppm B was displayed high sensitive response and wide potential window range of -1.7 V to 1.6 V with the detection limit of 0.001 mg/L to 0.01 mg/L ±5 % about heavy metal ions [Cd (II), Pb (II), Cu (II)].[1] M.O. Park et al, Electroanalysis. 2017, 29, pp. 514 – 520[2] J. –H. Yoon et al, Bull. Korean Chem. Soc. 2010, Vol. 31, No. 1This study was supported by the Korea Environmental Industry & Technology Institute[grant number 20190027400012] and R&D Center for Green Patrol Technologies through R&D for Global Top Environmental Technologies [grant number 20180018400013] funded by the Ministry of Environment, Republic of Korea (MOE), Figure 1

Highly efficient removal of aluminum, iron, and manganese ions using Linde type-A zeolite obtained from hazardous waste

Coal acid mine drainage (AMD) contaminates natural water to form mine-impacted water (MIW), which is characterized by high levels of acidity, sulfate, and metallic ions. This study investigates the use of a Linde Type-A (LTA) zeolite obtained from a hazardous industrial waste for Al3+, Fe2+, and Mn2+ removal from synthetic aqueous solutions. The aim of this study is to stablish a basis for the subsequent treatment of MIW in order to obtain reuse water. In a central composite rotatable design (CCRD) study, 8.25 g L−1 zeolite and 147 rpm were the optimal conditions for treating the multicomponent solution, yielding 99.9, 99.9 and 99.3% removal for Al3+, Fe2+, and Mn2+, respectively. Isothermal studies showed that the affinity of the ions by the zeolite were ranked as Al3+>Mn2+>Fe2+. The best fitting isothermal models for monocomponent solutions were Tóth, Freundlich, and Sips for Al3+, Fe2+, and Mn2+, respectively. In the multicomponent solution, Sips and Freundlich were the better fitting models for Al3+ and Mn2+, respectively, indicating a weakness of the sorbate-sorbent interactions. Kinetic studies revealed that the quantitative removal of Al3+ was achieved in 5 min. The multicomponent solution was transformed into water that was suitable for non-potable use after an optimal time of 60 min. The results demonstrate that LTA zeolite synthetized from hazardous waste has a high potential for remediating contaminated water by metallic ions at low dosages and short times. Using LTA zeolite for remediating contaminated water could make a positive contribution to the circular economy and environmental sustainability.

When It Comes to an End: Oxidative Stress Crosstalk with Protein Aggregation and Neuroinflammation Induce Neurodegeneration.

Neurodegenerative diseases are characterized by a progressive loss of neurons in the brain or spinal cord that leads to a loss of function of the affected areas. The lack of effective treatments and the ever-increasing life expectancy is raising the number of individuals affected, having a tremendous social and economic impact. The brain is particularly vulnerable to oxidative damage given the high energy demand, low levels of antioxidant defenses, and high levels of metal ions. Driven by age-related changes, neurodegeneration is characterized by increased oxidative stress leading to irreversible neuronal damage, followed by cell death. Nevertheless, neurodegenerative diseases are known as complex pathologies where several mechanisms drive neuronal death. Herein we discuss the interplay among oxidative stress, proteinopathy, and neuroinflammation at the early stages of neurodegenerative diseases. Finally, we discuss the use of the Nrf2-ARE pathway as a potential therapeutic strategy based on these molecular mechanisms to develop transformative medicines.

Molybdenum sulphide modified chelating resin for toxic metal adsorption from acid mine wastewater

Acid mine wastewater from mining industries leads to serious environmental problems due to its acidic nature and high levels of hazardous heavy metal ions. Thus, it is important to develop novel adsorbent materials for selective removing heavy metal ions. In this work, an amorphous molybdenum sulphide functionalized dipicolyamine exchanger were prepared and ultilised to scavenge toxic heavy metal ions from both synthetic and real acid mine waste water (copper mining industry). This new exchanger combines the advantages of exceptional heavy metal affinities from molybdenum sulphide and engineered macroporous structure from dipicolylamine resin. The results of batch and fixed-bed column tests suggest high selectivity towards heavy metals, fast adsorption kinetics, good reusability and excellent adsorption capacities in the sequence of Hg(II)≫Cd(II) > Cu(II). The metal adsorption mechanism has been demonstrated by X-ray Photoelectron Spectroscopy (XPS). Our findings support the potential practical application of this new material for scavenging heavy metal ions in mining wastewater.

Facile preparation of Ce enhanced vinyl-functionalized silica aerogel-like monoliths for selective separation of radioactive thorium from monazite

Thorium (Th) is an associated ore of rare earth metals that is radioactive and harmful to the environment, but it is also a potential nuclear fuel replacement for uranium. The separation of Th from rare earth elements (REEs) is of great importance in environmental governance and clean-energy development. In this work, a monolithic cerium (Ce) doped silica aerogel-like with flexibility was synthesized using a low consumption and rapid technique, and it was used in a continuous solid-phase extraction as an adsorbent for the selective separation of Th/REEs. The batch adsorption experiments showed that the adsorption efficiency of Th(IV) can be up to 96% when abnormally high levels of metal ions (20 ppm) exist. Under the same conditions, the adsorption efficiency of REEs is at a near-zero level, which demonstrates the great selective separation of Th/REEs for the aerogel-like. The results also indicated that Th(IV) could desorb from the adsorbent in weak acidic media, which is friendly to the environment. Therefore, the material has application prospects for the separation of Th/REEs and removal of radioactive contamination from the environment.

Attapulgite enhances methane production from anaerobic digestion of pig slurry by changing enzyme activities and microbial community

This study evaluated the effect of attapulgite addition on the anaerobic digestion of pig slurry. Results showed that attapulgite addition increased methane yield by 8.9%–37.3% and affected methane production kinetics. Attapulgite with the addition loading of 10 g/L obtained the highest methane yield of 210.4 mL/g volatile solids. Attapulgite accelerated the rates of hydrolysis, acetogenesis, and methanogenesis, as evidenced by the increases in the activities of β-glucosidase, protease, dehydrogenase, and coenzyme F420; the abundance of hydrolytic and acetogenic bacteria (Clostridiales, Syntrophobacterales, and Fibrobacterales); and the abundance of methanogenic microorganisms (Methanomicrobiales). These phenomena can be ascribed to both the reduced ammonia nitrogen due to attapulgite adsorption and the increased trace elements, such as Ca2+, Mg2+, K+, and Fe3+ ions, due to attapulgite release. However, excessive dose of attapulgite (≥30 g/L) decreased the promotion of methane production by reducing the enzyme activities of hydrolytic and methanogenic steps and lowering the abundance of hydrolytic, acetogenic, and methanogenic microorganisms due to the high levels of free ammonia and metal ions, such as Mg2+, at the initial phase of digestion. These results provided insights into the improvement of methane production during the anaerobic digestion of animal slurry.

Is end-organ surveillance necessary in patients with well-functioning metal-on-metal hip resurfacings? A cardiac MRI survey.

Cardiac magnetic resonance (CMR) was used to assess whether cardiac function or tissue composition was affected in patients with well-functioning metal-on-metal hip resurfacing arthroplasties (MoMHRA) when compared with a group of controls, and to assess if metal ion levels correlated with any of the functional or structural parameters studied. In all, 30 participants with no significant cardiac history were enrolled: 20 patients with well-functioning MoMHRA at mean follow-up of 8.3 years post-procedure (ten unilateral, ten bilateral; 17 men, three women) and a case-matched control group of ten non-MoM total hip arthroplasty patients (six men, four women). The mean age of the whole cohort (study group and controls) at the time of surgery was 50.6 years (41.0 to 64.0). Serum levels of cobalt and chromium were measured, and all patients underwent CMR imaging, including cine, T2* measurements, T1 and T2 mapping, late gadolinium enhancement, and strain measurements. None of the MoMHRA patients showed clinically significant cardiac functional abnormality. The MoMHRA patients had larger indexed right and left end diastolic volumes (left ventricular (LV): 74 ml/m2vs 67 ml/m2, p = 0.045; right ventricular: 80 ml/m2vs 71 ml/m2, p = 0.02). There was a small decrease in T2 time in the MoMHRA patients (median 49 ms vs 54 ms; p = 0.0003). Higher metal ion levels were associated with larger LV volumes and with shorter T2 time. Although cardiac function is not clinically adversely affected in patients with well-functioning MoMHRA, modern imaging is able to demonstrate subtle changes in structure and function of the heart. As these changes correlate with systemic ion measurements, they may be consequences of wear debris deposition. Longer, longitudinal studies are necessary to determine whether cardiac function will become affected. Cite this article: Bone Joint J 2019;101-B:540-546.

Association Between Pseudotumor Formation and Patient Factors in Metal-on-Metal Total Hip Arthroplasty Population

BackgroundPseudotumor formation from metal-on-metal (MoM) hip implants is associated with implant revision. The relationship between pseudotumor type and patient outcomes is unknown. MethodsWe retrospectively reviewed patients with a MoM total hip arthroplasty and metal artifact reduction sequence magnetic resonance imaging. Pseudotumors were graded using a validated classification system by a fellowship-trained radiologist. Patient demographics, metal ion levels, and implant survival were analyzed. ResultsPseudotumors were present in 49 hips (53%). Thirty-two (65%) pseudotumors were cystic thin walled, 8 (16%) were cystic thick walled, and 9 (18%) were solid masses. Patients with pseudotumors had high offset stems (P = .030) but not higher metal ion levels. Patients with thick-walled cystic or solid masses were more likely to be symptomatic (P = .025) and were at increased risk for revision (P = .004) compared to patients with cystic lesions. ConclusionPseudotumor formation is present in 53% of patients with a MoM total hip arthroplasty, of which 40% were asymptomatic. Patients with thick-walled cystic and solid lesions were more likely to be symptomatic and undergo revision.

Cadmium and Nickel Toxicity for Sinapis alba Plants Inoculated with Endophytic Strains of Bacillus subtilis

We studied the effect of cadmium and nickel on Sinapis alba L. plants inoculated with endophytic strains of Bacillus subtilis. It was shown that treatment of S. alba seeds with endophytic strains of bacteria B. subtilis improves plant resistance to the toxic effect of cadmium and nickel and reduces manifestation of oxidative stress in the presence of higher levels of metal ions in the above-ground part of plants. Anti-stress effect and the ability of endophytic strains of B. subtilis to intensify uptake of cadmium and nickel ions by S. alba plants may be used for phytoextraction of heavy metals and stimulation of plant growth in contaminated areas.