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Background: Biofortification with selenium (Se) elevates its concentration in feed and fodder plants and helps to prevent health problems in animals and humans. The aim of this study was to describe Se-induced modifications in the accumulation of elements important for the proper functioning of wheat, one of the most popular cereals. The presence of Se correlated with carbohydrate synthesis and electron paramagnetic resonance (EPR). This explained the mechanisms of Se's antioxidant activity., Results: Selenium accumulation in vegetative and generative leaves, and in the grains of three wheat genotypes (cv. Parabola, cv. Raweta and cv. Manu), differing in their stress tolerance and grown hydroponically in the presence of 10 or 20 μM Na 2 SeO 4, , was proportional to its content in the medium. Stronger Se accumulation was typical of a stress-sensitive genotype. Selenium generally promoted the uptake of macronutrients and micronutrients but their distribution depended on tissue and genotype. Changes in the Se-induced EPR signals of paramagnetic metals and organic radicals corresponded with stress tolerance of the tested genotypes., Conclusions: Se application increased the accumulation of nutrients and carbohydrates that are vital for proper plant growth and development. Accelerated uptake of molybdenum (Mo), an element improving dietary properties of grains, may be an additional advantage of Se fertilization. The mechanisms of Se-induced changes in removing Mn and iron (Fe) ions from macromolecules may be one of the factors that differentiate plant tolerance to oxidative stress. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

The purpose of this work was to determine trace element levels in urine and evaluate possible associations between urinary iodine concentration (UIC), other trace elements (Cr, Cu, Fe, Mn, Na, Se, Zn), toxic elements (Cd, Pb), anthropometrical measures (body weight and height), glycemic indices (serum insulin and glucose), and several parameters related to thyroid function (thyroid stimulating hormone, free thyroxine, antithyroid peroxidase antibodies, thyroid volume, and thyroid echogenicity) in pregnant women. One hundred sixty-nine participants were recruited. The whole study group, originating from Krakow region, comprised three subgroups belonging to three trimesters: I trimester (n = 28), II trimester (n = 83), and III trimester (n = 58). Trace elements were determined using inductively coupled plasma mass/(atomic emission) spectrometry. Partial least square model was used to reveal correlation structure between parameters investigated, as well as a possible causal relationship between dependent parameters and potentially explanatory parameters. Results obtained for trace and toxic elements in urine were comparable with results of other authors, although the study group was not homogenous. We confirmed (1) low iodine excretion in pregnant women, (2) the existence of statistically significant correlation between UIC and urinary selenium, and (3) lack of correlation between latter parameter and typical indices of thyroid function. Urinary selenium correlated with other urinary trace elements, but physiological significance of this finding remains uncertain. The fact that a large number of pregnant women fail to meet dietary recommendations for iodine is the major reason for concern.

This study was performed to investigate selenoenzyme activities and trace element concentrations in thyroid tissues, with reference to other parameters routinely used to characterize thyroid function. This was to reveal relevant parameters as possible additional markers of tumor grade, clinical course, and prognosis of thyroid disorders. The tissue samples were obtained during surgical treatment (total or near total thyroidectomy) of 122 patients with different types of thyroid tumor. For most of the investigated parameters in different groups of patients, we did not find statistically significant differences. In the majority of cases, thyroid benign or malignant tumors were not accompanied by significant derangement of the gland selenoenzymes and of either intrathyroidal or plasma concentration of selenium. Nevertheless, types I and II iodothyronine deiodinases were the most promising (among selenoenzymes) targets for diagnoses and possibly therapy of thyroid tumors. Higher activities of both enzymes in cases with Graves' disease, as compared with other thyroid lesions, suggest their involvement in the pathogenesis of this condition. Patients with struna nodosa had higher levels of thyroid Zn, Cu, and Pb as compared with papillary carcinoma subjects and also a higher level of Cu than follicular carcinoma cases. The above diagnostics may play a similar role to some of the general thyroid function indices, TSH, anti-TG, anti-TPO, and calcitonin, which can partially distinguish between various thyroid tumors. In conclusion, some of selenium status markers, when accompanied with general parameters, and trace elements can serve as factors with pathophysiologic relevance and be helpful in the identification of malignant disease. Multivariate statistical methods should be employed to tackle a broad array of thyroid tumor diagnostic data in a short time. Partial least squares model and other pattern recognition methods seem to be the most appropriate methods for that task. The miniaturization of all the steps of complex analytical procedure should be developed in a way to allow its completion as sensitive, robust, and efficient for use of the small quantity of material provided by fine-needle biopsy.

The aim of this study was to examine changes in activities of cytochrome c oxidase (CCO), glucose-6-phosphate dehydrogenase (G6PDH), Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px), glutathione (GSH) levels and copper (Cu), zinc (Zn) and selenium (Se) concentrations, and to assess the possible differences between preterm placentas, placentas from term pregnancies complicated by intrauterine growth restriction (IUGR) and full-term control placentas. The enzyme activities and the level of GSH decreased in IUGR and preterm placentas in comparison with the control group. CCO activity and GSH level in preterm placentas were markedly lower compared with the IUGR (P<0.01; P<0.05) and control (P<0.01; P<0.05) placentas, respectively. In IUGR placentas the level of Cu was reduced by 23% (P<0.05) and Zn by 37%. In preterm placentas the level of Cu was reduced by 19% and Zn by 42%. Se level in IUGR and preterm placentas was higher (P<0.05) by 28% and 32% than in control group, respectively. The strong relation was observed between birth weight and CCO activity, birth weight and Cu-Zn SOD activity, and a low level of Zn and Cu influenced the birth weight especially in IUGR cases. Moreover, the strong inverse correlation between Se level and birth weight, Se level and placental weight and Se level and CCO activity are new findings.

We investigated the relations between selenium status (SeS) parameters, indexes of nutrition, erythropoiesis, and uremic toxemia, serum electrolytes, and other biochemical markers in end-stage renal disease (ESRD) patients, as no multivariate statistical analysis concerning all of these parameters was performed so far. SeS was evaluated by plasma Se concentration (plSe) and glutathione peroxidase (plGSHPx) activity in 69 uremic patients treated with hemodialysis (HD) and 40 healthy controls. The hierarchical multivariate partial least squares model (PLS2) was employed to establish data structure and correlations between parameters investigated. plSe and plGSHPx activity were significantly lower in patients when compared with controls (p=0.000). plSe was positively associated with indexes of erythropoiesis and nutritional status, as well as serum electrolytes and parameters of uremic toxemia. plGSHPx was inversely dependent on the pair of parameters: intact parathyroid hormone (iPTH) and aluminum plasma concentration (Al). We conclude that (1) ESRD strongly decreases selenium status and (2) the PLS2 approach revealed the existence of significant interactions among plSe, plGSHPx, and selected biochemical parameters or groups of such parameters; some of these associations need further studies to be clarified.

Selenium (Se) is essential for health of humans, animals, and plants. Especially wheat is a major source of Se in the terrestrial food chain. In this study, an element analysis was optimized and the content of Ca, Mg, K, S, P, Fe, Se, Mn, Cu, Zn, and Mo in leaves, roots, and seeds were measured during growth of wheat ( Triticum aestivum L. cv. Manu) in Hoagland nutrient solution with 5 and 15 μM NaSeO. Se was transported to all investigated tissues and accumulated in the seeds in proportion to used amounts. The supplementation of Se, independently of concentration, weakly modified the micro- and macro-elements content in the seedlings. In the flag-leaf stage, an increase of the Mo and S content in the shoots and the S and Cu content in the roots was found. Moreover, in the generative phase, a decrease in Ca and Fe in the roots was registered. Increased Se in the nutrient solution strongly stimulated the Se accumulation in the seeds. [ABSTRACT FROM AUTHOR]