Click evoked otoacoustic emissions in occupational exposure to lead, concentrations of selected essential elements and markers of oxidative stress.

PURPOSE: This study focused on the selected markers of oxidative stress, impact of elevated lead levels on long-term hearing quality. We investigated whether the presence of certain essential minerals might provide protection to the auditory system against the effects of lead (and cadmium) compounds. METHODS: The research group included 280 male employees of the zinc and lead smelter, which was divided into: L-Pb-low blood lead concentration (PbB) subgroup, H-Pb-high PbB subgroup. Hearing tests were performed using the click evoked otoacoustic emission (CEOAE). RESULTS: Zinc protoporphyrin level was significantly higher in the H-Pb subgroup by 68%. Cd concentration was significantly higher in H-Pb by 33%. The Ca concentration was significantly lower in the H-Pb by - 2%. Selected oxidative stress markers concentration were significantly higher in the H-Pb group: malondialdehyde (MDA) by 4%, and lipofuscin (LPS) by 9%. In the CEOAE results showed statistically significant differences between the L-Pb and H-Pb subgroups. Larger negative changes in otoemission amplitude were observed in H-Pb subgroup. All otoemission results showed a statistically significant negative correlation with age, time of work, MDA concentration, and with PbB. Selected CEOAE parameters showed a significant negative correlation with cadmium blood concentration (CdB), and a positive correlation with Ca and Zn. CONCLUSION: Elevated blood lead content in occupational exposure is associated with an increase in MDA and LPS concentration, which negatively correlates with CEOAE parameters. This suggests an important role of oxidative stress in the long-term deterioration of hearing.

Effect of Cadmium on Oxidative Stress Indices and Vitamin D Concentrations in Children.

Heavy metal poisoning can have serious health consequences, including damage to the brain, kidneys, and other organs. Cadmium is a toxic heavy metal that can accumulate in the body over time and the exposure to this element has been linked to a variety of adverse health effects. Cadmium toxicity can lead to an imbalance in the cellular redox state and be a source of oxidative stress. On the molecular level, cadmium ions negatively affect cellular metabolism, including the disruption of energy production, protein synthesis, and DNA damage. The study has been carried out on a group of 140 school-age children (8 to 14 years old) inhabiting the industrialized areas of Upper Silesia. The study population was divided into two sub-groups based on the median concentration of cadmium in blood (0.27 µg/L): Low-CdB and High-CdB. Measured traits comprised blood cadmium levels (CdB) as well as a blood count and selected oxidative stress markers. This research study aimed to demonstrate a correlation between the impact of exposure to elevated cadmium concentrations in a population of children and certain markers of oxidative stress, and 25-OH vitamin D3 concentration. A negative correlation has been found between cadmium concentration and 25-OH vitamin D3 level, protein sulfhydryl groups content in blood serum, glutathione reductase activity, and lipofuscin and malondialdehyde levels in erythrocytes. The concentration of 25-OH vitamin D3 in the High-CdB group was decreased by 23%. The oxidative stress indices can be considered a valuable indicator of early Cd-toxicity effects to be included in the routinely-applied cadmium exposure monitoring parameters, allowing the evaluation of stress intensity to the cell metabolism.

Relationship between Postural Stability, Lead Content, and Selected Parameters of Oxidative Stress.

This study attempts to determine whether the increased blood lead concentration affects the posturographic test and to determine the relationship between the parameters of posture stability and selected parameters of oxidative stress. The study population consisted of 268 male employees and was divided into two equal subgroups, depending on the lead content in the blood. A posturographic examination was performed. Concentrations of lead, cadmium, zinc protoporphyrin, selected essential elements, and selected markers of oxidative stress in the blood were tested. Higher blood lead concentrations positively affected the values of the sway results: the field and the mean velocity of the center of the feet pressure in posturography. The absolute value of the proprioception ratio was similar in both subgroups. The content of malondialdehyde shows a statistically significantly higher value in a subgroup with high blood lead concentration and exhibits significant correlations only with some of the posturography parameters. The lipofuscin content in erythrocytes correlates with the results of the posturography test. Zinc protoporphyrin, total oxidant status, total antioxidant capacity, selected minerals, and metals did not correlate with the results of the posturography test. In conclusion, posturographic results correlate only with selected markers of oxidative stress, so it can be assumed that the effect on the body balance is only partial.

Validation of the test for detecting SARS--CoV-2 antigens in the Polish population in patients with suspected SARS-CoV-2 infection.

In December 2019, the World Health Organization (WHO) reported that China had accumulated pneumonia of unclear etiology in Wuhan. According to WHO recommendations, in strictly defined situations, antigen tests can be implemented into the diagnostic algorithm to reduce the number of molecular tests performed and support the rapid identification and treatment of COVID-19 patients. According to WHO recommendations, the antigen test for diagnostic use should have a sensitivity of ≥ 80% and a specificity of ≥ 97% compared to molecular tests (NAAT). Based on the comparative analysis, the sensitivity and specificity of the SARS-CoV-2 Antigen ELISA test were determined concerning the RT-PCR reference method. The sensitivity of the SARS-CoV-2 Antigen ELISA was 100% (51/51) and the specificity was 98.84%. The obtained data demonstrate that the analyzed antigen test meets both the WHO and the Ministry of Health criteria.

Effects of environmental and occupational lead toxicity and its association with iron metabolism.

BACKGROUND: Discrepancies are present in the findings from clinical trials evaluating a physiological role of iron status in the lead-exposed population. OBJECTIVE: The purpose of this article was to summarize the current understanding of cellular mechanisms of lead toxicity and present a comprehensive review of existing clinical trials related to associations of lead poisoning and iron status. Although an association of iron metabolism pathways that are affected by lead intoxication has been studied, there are still aspects that remain to be elucidated. The existence of additional Pb uptake pathways besides DMT1 transporter-mediated is postulated to non-specifically regulate lead absorption. METHODS: Authors performed a systematic search of PubMed, EMBASE® and Web of Science databases to identify studies that reported an association between health risks of non-organic lead that are associated with iron status markers as possible effect modifier. RESULTS: There were 58 studies that met the pre-defined inclusion criteria for the systematic review. There is a strong body of evidence supporting the hypothesis that alleviated blood lead level can be correlated with a reduced body iron store and increasing the risk of anemia. This association is of a high significance in cases of a young adolescent, weaker in groups of older children and often without a statistical significance in adults. DISCUSSION: Discrepancies in the observations may result from different specificities of lead absorption pathways in children and adults, as well as the power of the statistical tests in varying population sizes. It may be assumed that the extent of iron deficits coupled together with source, timing, and severity of lead exposure, significantly influence the correlation between these factors. Some of the intervention programs of counteracting lead poisoning by iron supplementation proved to be effective and may be a promising prevention strategy for the exposed population.

Relationship between lead absorption and iron status and its association with oxidative stress markers in lead-exposed workers.

BACKGROUND: The emission of lead (Pb) occurring during the extraction, processing and industrial applications of this element remains a significant environmental risk factor. The absorbability of lead in humans is strongly associated with the general health status of exposed individuals. Existing mineral deficiencies are considered being a predisposition to an increased Pb uptake. Both, iron deficiency and lead poisoning are the major causative factors responsible for the prevalence of anemia within the vulnerable population, especially in children. Although some of the intervention programs of counteracting lead poisoning by iron supplementation proved to be effective in the Pb-exposed population, the exact mechanisms of this interaction still require further studies. The objective of the presented study was to examine the association of iron level on oxidative stress measures and its effects on the severity of lead toxicity in the exposed population. METHODS: The analyzed population consisted of 270 male workers from the lead-zinc smelter. The studied population was divided into two sub-groups based on the serum iron concentration: low iron level group (L-Fe; Fe < median value) and high iron level group (H-Fe; Fe > median value). Measured traits comprised of blood lead (PbB), serum Fe and zinc protoporphyrin (ZPP) levels as well as a blood count and oxidative stress markers. RESULTS: No significant correlation between serum iron concentration and PbB in the tested cohort was found. On the contrary, the analysis of ZPP levels (long-term marker related to a hematologic toxic effect of Pb) within the subgroups differing in serum Fe level shown that ZPP was 12.3 % lower (p = 0.043) in subjects classified within the H-Fe group. A positive correlation of serum Fe and total antioxidant capacity (TAC) was found (R = 0.1999). The conducted 3-D PCA analysis showed that individuals classified within the H-Fe group were characterized by the co-occurrence of higher Fe levels, lower ZPP, and higher TAC value. CONCLUSION: These results support the existing evidence providing that maintaining the optimal status of Fe may play a significant role in preventing the lead poisoning and alleviating harmful effects of Pb on the oxidative balance in humans.

Methods for the Simple and Reliable Assessment of Barley Sensitivity to Abiotic Stresses During Early Development.

Physiological assays that facilitate screening for various types of responses to abiotic stresses are well established for model plants such as Arabidopsis; however, there is a need to optimize similar tests for cereal crops, including barley. We have developed a set of stress assays to characterize the response of different barley lines during two stages of development-seed germination and seedling growth. The assays presented, including the response to osmotic, salt, oxidative stresses, and exogenously applied abscisic acid, can be used for forward screening of populations after mutagenesis as well as for phenotyping of already isolated mutants, cultivars, or breeding lines. As well as protocols for stress treatments, we also provide methods for plant stress response evaluation, such as chlorophyll a fluorescence (ChlF) and image analysis.

Analysis of aluminum toxicity in Hordeum vulgare roots with an emphasis on DNA integrity and cell cycle.

Barley is one of the cereals that are most sensitive to aluminum (Al). Al in acid soils limits barley growth and development and, as a result, its productivity. The inhibition of root growth is a widely accepted indicator of Al stress. Al toxicity is affected by many factors including the culture medium, pH, Al concentration and the duration of the treatment. However, Al can act differently in different species and still Al toxicity in barley deserves study. Since the mechanism of Al toxicity is discussed we cytogenetically describe the effects of different doses of bioavailable Al on the barley nuclear genome-mitotic activity, cell cycle profile and DNA integrity. At the same time, we tested an established deep-water culture (DWC) hydroponics system and analyzed the effects of Al on the root system parameters using WinRHIZO software. We demonstrated the cytotoxic and genotoxic effect of Al in barley root cells. We showed that Al treatment significantly reduced the mitotic activity of the root tip cells and it also induced micronuclei and damaged nuclei. The DNA-damaging effect of Al was observed using the TUNEL test. We define the inhibitory influence of Al on DNA replication in barley. Analysis with the labelling and detection of 5-ethynyl-2'-deoxyuridin (EdU) showed that the treatment with Al significantly decreased the frequency of S phase cells. We also demonstrated that Al exposure led to changes in the cell cycle profile of barley root tips. The delay of cell divisions observed as increased frequency of cells in G2/M phase after Al treatment was reported using flow cytometry.

Mutation in HvCBP20 (Cap Binding Protein 20) Adapts Barley to Drought Stress at Phenotypic and Transcriptomic Levels.

CBP20 (Cap-Binding Protein 20) encodes a small subunit of the cap-binding complex (CBC), which is involved in the conserved cell processes related to RNA metabolism in plants and, simultaneously, engaged in the signaling network of drought response, which is dependent on ABA. Here, we report the enhanced tolerance to drought stress of barley mutant in the HvCBP20 gene manifested at the morphological, physiological, and transcriptomic levels. Physiological analyses revealed differences between the hvcbp20.ab mutant and its WT in response to a water deficiency. The mutant exhibited a higher relative water content (RWC), a lower stomatal conductance and changed epidermal pattern compared to the WT after drought stress. Transcriptome analysis using the Agilent Barley Microarray integrated with observed phenotypic traits allowed to conclude that the hvcbp20.ab mutant exhibited better fitness to stress conditions by its much more efficient and earlier activation of stress-preventing mechanisms. The network hubs involved in the adjustment of hvcbp20.ab mutant to the drought conditions were proposed. These results enabled to make a significant progress in understanding the role of CBP20 in the drought stress response.

An automated, cost-effective and scalable, flood-and-drain based root phenotyping system for cereals.

BACKGROUND: Genetic studies on the molecular mechanisms of the regulation of root growth require the characterisation of a specific root phenotype to be linked with a certain genotype. Such studies using classical labour-intensive methods are severely hindered due to the technical limitations that are associated with the impeded observation of the root system of a plant during its growth. The aim of the research presented here was to develop a reliable, cost-effective method for the analysis of a plant root phenotype that would enable the precise characterisation of the root system architecture of cereals. RESULTS: The presented method describes a complete system for automatic supplementation and continuous sensing of culture solution supplied to plants that are grown in transparent tubes containing a solid substrate. The presented system comprises the comprehensive pipeline consisting of a modular-based and remotely-controlled plant growth system and customized imaging setup for root and shoot phenotyping. The system enables an easy extension of the experimental capacity in order to form a combined platform that is comprised of parallel modules, each holding up to 48 plants. The conducted experiments focused on the selection of the most suitable conditions for phenotyping studies in barley: an optimal size of the glass beads, diameters of the acrylic tubes, composition of a medium, and a rate of the medium flow. CONCLUSIONS: The developed system enables an efficient, accurate and highly repeatable analysis of the morphological features of the root system of cereals. Because a simple and fully-automated control system is used, the experimental conditions can easily be normalised for different species of cereals. The scalability of the module-based system allows its capacity to be adjusted in order to meet the requirements of a particular experiment.