Assessment of essential and toxic trace element levels in erythrocytes of hemodialysis patients with end-stage renal disease.

BACKGROUND: Chronic kidney disease (CKD) is a global public health problem, resulting in end-stage kidney disease, cardiovascular disease, and premature death. AIM: The aim of the study was to determine the profile of essential and toxic trace elements in erythrocytes of patients with end-stage renal disease (ESRD) and their relationship with selected anthropometric and biochemical parameters. METHODS: The present study compared the profiles of trace elements, including toxic sub-stances, in the erythrocytes of 80 hemodialysis patients with CKD with 40 healthy subjects. All patients had stage 5 CKD. The levels of Cd and Pb were determined by graphite furnace atomic absorption spectrometry and levels of Fe, Mn, Zn, Cu Cr, Ni, and Li by inductively coupled plasma atomic emission spectrometry. RESULTS: The ESRD patients demonstrated significantly lower Fe and Zn concentrations and significantly higher Mn and Li and toxic Pb and Cd concentrations in erythrocytes compared to those of the healthy controls. Negative correlations were observed, among others, between the concentrations of Cu, Li, and creatinine; Cu and phosphates; Mn, Pb, and transferrin saturation while positive correlations were noted between Cu, Cr, and transferrin and Pb, Cr, and the normalized protein catabolism rate. CONCLUSIONS: The higher concentrations of toxic elements present in the erythrocytes of CKD patients might have resulted from the reduced ability of the kidneys to excrete them. Moreover, differences in the concentrations of essential elements (Fe, Mn, Zn) between the two groups indicated that their resorption in the kidneys of CKD patients was impaired. Patients with CKD might benefit from interventions intended to reduce high, toxic concentrations of Pb and Cd and Li and Mn as an alternative supportive treatment. Iron and zinc supplementation should be a component for the treatment of anemia in CKD patients.

Mercury in Selected Abiotic and Biotic Elements in Two Lakes in Poland: Implications for Environmental Protection and Food Safety.

Mercury, which tends to bioaccumulate and biomagnify in aquatic food webs, poses a potential health risk to wildlife and to consumers of predatory fish in particular. Its concentration in biota can be high even at low environmental concentrations. Therefore, the aim of this study was to determine mercury in both abiotic (water and sediment) and biotic elements (common reed (Phragmites australis) and fish: pike (Esox lucius), bream (Abramis brama) and roach (Rutilus rutilus)) in the context of assessing the pollution of two lakes in Poland and the safety of fish consumers. The possibility of Hg biomagnification in fish was also considered. Mercury was determined by means of cold vapor atomic absorption spectrometry (CVAAS). The concentrations of Hg in water and bottom sediments of Lake Insko were lower than in Lake Wisola. In the bottom sediments of both lakes, a positive correlation was found between the Hg content and organic matter. The concentration of mercury in the organs of common reed did not exceed 0.017 mg/kg dry weight (dw), and its distribution can be presented as follows: root > leaves > stems > rhizomes. In fish organs from both lakes, the average mercury content did not exceed 0.086 mg/kg of wet weight (ww) and in most cases it was the highest in pike. Higher values were only observed in the muscles and skin of roach. This indicates a lack of biomagnification in the relationships between planktivorous-predatory and benthivores-predatory fish. Based on the maximum levels of mercury in fish and the calculated parameters, i.e., estimated daily intake (EDI), target hazard quotient (THQ) and tolerable weekly intake (TWI), the muscles of the examined fish were found to be safe for consumption. The average dietary exposure to total mercury (THg) and methylmercury (MeHg) was below 0.3% of the TWI.

Heavy Metals and the Occurrence of Ulcerative Dermal Necrosis (UDN) in Sea Trout from the RIVER REGA, Poland-Consumer Health Assessment.

Various factors, including heavy metals, can make fish more susceptible to disease. This study investigated, inter alia, the relationship between Pb, Cd, and Hg contamination of the organs and muscles of sea trout from the river Rega (Poland) and the occurrence of UDN (ulcerative skin necrosis) symptoms. Moreover, the dietary risk of Pb, Cd, and Hg uptake from the muscles of healthy sea trout was assessed based on estimated daily intake (EDI), target hazard quotient (THQ), benchmark dose lower confidence limits (BMDL01 and BMDL10), and tolerable weekly intake (TWI). The metal concentrations varied, depending on the fish organs and the fish condition. A significantly higher amount of Pb was found in the gonads, gills, and muscles, Cd in the kidneys, and Hg in the muscles of sea trout with UDN symptoms. The lowest concentrations of Pb and Cd were detected in the muscles, and of Hg in the gonads. Dietary exposure to Pb, Cd, and Hg accounted for: 0.4% of BMDL01 and 1.0% of BMDL10, 0.56% of TWI, and 16.5% of TWI, respectively. THQs for each metal and the HI value for combined metals were below 1. The weakening of fish due to UDN-like disease probably increased the accumulation of Pb in the gonads, gills, and muscles, and of Cd in the kidneys, of the sea trout. As regards the maximum levels (MRLs), the muscles of healthy sea trout are safe for consumption. The risk assessment suggests no concern for the health of consumers.

Health benefits and risks associated with element uptake from grilled fish and fish products.

BACKGROUND: The content of essential and toxic elements in grilled fish (Atlantic salmon, trout) and in 20 assortments of fish products was examined. The aim of this study was to assess the fulfilment of the demand for Zn, Fe, Mn and Cu based on recommended dietary allowances (RDAs) or adequate intakes (AIs) and to assess the health risk associated with the consumption of Al, Pb and Cd. The risk assessment was based on estimated weekly intake (EWI), hazard index (HI), target risk ratio (THQ) and percentage: provisional tolerable weekly intake (PTWI) for Al, tolerable weekly intake (TWI) for Cd and reference dose lower bound (BMDL) for Pb. RESULTS: Taking into account the health benefits, the best source of Fe, Cu and Mn was found to be fish products in cans and jars, 150 g of which covered the daily requirement: Fe 9.39%, Cu 2.91% and Mn 1.21%. Smoked fish covered the RDA for Zn to 5.69%. Moreover, the uptake of toxic elements was as follows: Al 0.45% PTWI: Pb 0.74% BMDL10 and Cd 2.20% TWI. The THQ values for Pb and Cd were significantly lower than 1, whereas for Al it reached as high as 4.0. CONCLUSION: The obtained results indicate that there is no risk related to the intake of Pb and Cd with the consumption of the tested fish products. Low consumption of fish by Poles, however, contributes to their small share in covering the demand for microelements, i.e. Zn, Fe, Mn and Cu. © 2021 Society of Chemical Industry.

Psychophysiological, but Not Behavioral, Indicator of Working Memory Capacity Predicts Video Game Proficiency.

Visual working memory (VWM) is the ability to actively maintain visual information over short periods of time and is strongly related to global fluid intelligence and overall cognitive ability. In our study, we used two indices of visual working memory capacity: the behavioral estimate of capacity (K) and contralateral delay activity (CDA) in order to check whether training in a Real-Time Strategy (RTS) video game StarCraft II can influence the VWM capacity measured by the change detection task. We also asked a question whether individual differences in behavioral and psychophysiological indices of VWM can predict the effectiveness of video game training. Sixty-two participants (non-players) were recruited to the experiment. Participants were randomly assigned to either experimental (Variable environment), active control (Fixed environment), and passive control groups. Experimental and active control groups differed in the type of training received. Training consisted of 30 h of playing the StarCraft II game. Participants took part in two EEG sessions (pre- and post-training) during which they performed the VWM task. Our results showed that working memory capacity (K calculated according to Pashler's formula) increases after training in both experimental groups, but not in a control group. We have also found a correlation between average visual working memory capacity (calculated as K) and mean CDA amplitude no matter which group we are looking at. And, last but not least, we have found that we can predict the amount of improvement in the RTS video game by looking at the psychophysiological indices (CDA amplitude) recorded at baseline (before training), but only in the experimental group. We think that the strength of the psychophysiological indicator of VWM capacity might be a marker of the future success in video game acquisition.

The role of individual differences in attentional blink phenomenon and real-time-strategy game proficiency.

The impact of action videogame playing on cognitive functioning is the subject of debate among scientists, with many studies showing superior performance of players relative to non-players on a number of cognitive tasks. Moreover, the exact role of individual differences in the observed effects is still largely unknown. In our Event-Related Potential (ERP) study we investigated whether training in a Real Time Strategy (RTS) video game StarCraft II can influence the ability to deploy visual attention measured by the Attentional Blink (AB) task. We also asked whether individual differences in a psychophysiological response in the AB task predict the effectiveness of the video game training. Forty-three participants (non-players) were recruited to the experiment. Participants were randomly assigned to either experimental (Variable environment) or active control (Fixed environment) group, which differed in the type of training received. Training consisted of 30 h of playing the StarCraft II game. Participants took part in two EEG sessions (pre- and post-training) during which they performed the AB task. Our results indicate that both groups improved their performance in the AB task in the post-training session. What is more, in the experimental group the strength of the amplitude of the P300 ERP component (which is related to a conscious visual perception) in the pre training session appeared to be predictive of the level of achievement in the game. In the case of the active control group in-game behaviour appeared to be predictive of a training-related improvement in the AB task. Our results suggest that differences in the neurophysiological response might be treated as a marker of future success in video game acquisition, especially in a more demanding game environment.

Lenticular nucleus volume predicts performance in real-time strategy game: cross-sectional and training approach using voxel-based morphometry.

It is unclear why some people learn faster than others. We performed two independent studies in which we investigated the neural basis of real-time strategy (RTS) gaming and neural predictors of RTS game skill acquisition. In the first (cross-sectional) study, we found that experts in the RTS game StarCraft® II (SC2) had a larger lenticular nucleus volume (LNV) than non-RTS players. We followed a cross-validation procedure where we used the volume of regions identified in the first study to predict the quality of learning a new, complex skill (SC2) in a sample of individuals who were naive to RTS games (a second (training) study). Our findings provide new insights into how the LNV, which is associated with motor as well as cognitive functions, can be utilized to predict successful skill learning and be applied to a much broader context than just video games, such as contributing to optimizing cognitive training interventions.

Toxic Elements and Mineral Content of Different Tissues of Endemic Edible Snails (Helix vladika and H. secernenda) of Montenegro.

The objective of the present study is to determine the differences between the mineral content of various organs of Helix vladika and H. secernenda, the two most abundant edible snail species in Montenegro. The bioaccumulation of 12 examined elements (zinc, manganese, copper, aluminum, cadmium, lead, nickel, iron, chromium, lithium, selenium and mercury) was determined in the hepatopancreas, albumen gland, digestive tract, reproductive system, mantle, foot and shell from three sampling sites (Biogradska Gora, Niksic and Malesija). The examined populations of H. vladika and H. secernenda showed a significant difference in their lithium and selenium contents. The levels of the most examined metals (Zn, Mn, Cu, Al, Cd, Pb, Se and Hg) varied significantly among organs. The digestive tract and hepatopancreas tend to bioaccumulate selenium and cadmium. The general mean concentration of cadmium in the examined snail tissues exceeded the maximum allowable level at the Biogradska Gora and Malesija sites. Therefore, the use of the Montenegrin edible snails collected from the wilderness for human consumption seems to be limited by their higher bioaccumulation capacity for toxic elements such as cadmium.

Acute Lethal Toxicity of Heavy Metals to the Seeds of Plants of High Importance to Humans.

Laboratory experiments were conducted to assess the effects of highly toxic and dangerous metals (Pb, Cd, Hg) and essential microelements (Cr, Cu, Ni, Zn) on the seed germination process in vetch and eight plant species of major importance to human consumption. The degree of metal toxicity was determined on the basis of acute LC50 values calculated by means of two different methods. All the metals were found to inhibit the germination process, but in a varying, species-dependent degree. Of all the plant seeds under study, the most sensitive to the presence of the examined metals during germination were the seeds of cress (Cu, Pb, Hg), rye (Ni, Zn, Cd) and barley (Cr), while vetch (Cr, Ni, Zn, Cd, Pb, Hg), rape (Cr, Cu) and pea (Ni, Cd) were found to be least affected.