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Background: The measurement of selenium in human plasma is useful to assess deficiency or toxicity. The presence of gadolinium in clinical samples following administration of certain contrast agents used for magnetic resonance imaging can cause a significant positive bias in selenium results when measured using quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS).Methods: A mathematical equation to correct for gadolinium interference was assessed using both patient samples and commercial quality control/external quality assurance (QC/EQA) materials spiked with gadolinium. Samples were analysed using an Agilent 7900 ICP-MS operated in 'narrow peak' (half-mass) mode. Accuracy was evaluated by comparing corrected selenium results with target concentrations.Results: Corrected results were found to be accurate at all gadolinium concentrations tested (2, 4, 10 and 20 mg/L). Average recoveries ranged from 97.4 to 106.5%. Results for QC/EQA materials were within specified target ranges. Within-run imprecision was <3%, and between-run imprecision was <4.3%, demonstrating robustness.Conclusions: The correction equation described here is a simple method to correct for gadolinium interference on plasma selenium measurement using ICP-MS. This approach eliminates the need for specimen recollections, and improves patient care by reducing laboratory turnaround times and preventing delays in diagnosis/treatment. [ABSTRACT FROM AUTHOR]

Biofortification of crops with selenium is one of the possible manners on how to increase selenium intake by humans. The effect of selenium fertilization in relation to selenium enrichment of pea and following the phytotoxicity symptoms in garden pea plants was studied. Pot experiments were established with a control variant without selenium addition and four variants where selenium was applied as sodium selenate into the soil in four different concentrations (1 - 6 mg Se.kg-1) before seeding. Garden pea was grown in pots for 60 days and then plant material was dried and submitted to analysis. The total content of selenium was determined by the ZET-AAS method in the roots, above-ground parts of the plant (stems, leaves, extracted pods), and in seeds of a pea. Dean-Dixon's test and paired t-test (a = 0.05) were used for statistical evaluation of the results. Transfer factors were calculated as a ratio between selenium content (mg.kg-1) in individual plant material and soil. Transfer indexes were calculated as a ratio between selenium content (mg.kg-1) in seeds and roots. The results showed that with the increasing addition of the Se to the soil, its contents in all parts of the plant proportionally increased. The content of the Se increased in the roots 43 to 173-fold, in the above-ground parts 79 to 372-fold, and in the seeds Se was accumulated 130 to 415 times more compared to control. Transfer factors and transport indexes were expressed. Transfer factors for pea varied from 11.05 to 19.25 in the case of Se transfer to the whole pea biomass. In the case of the Se transfer from soil to pea seeds, the highest transfer showed variant with addition 1 mg Se.kg-1 and the transfer factor gradually decreased with increasing addition of Se. Based on the amount of biomass produced, the experiments statistically confirmed the phytotoxicity of higher doses (4 and 6 mg Se.kg-1) of selenium to plants. The highest transport index values are shown variants with the Se addition 1 and 2 mg Se.kg-1 (2.03 and 1.77, respectively). In these variants, Se was used the most efficiently. Our results showed that the best biofortification results were obtained in experimental variants with the lower selenium additions (1 and 2 mg Se.kg-1). [ABSTRACT FROM AUTHOR]

Abstract Background It is necessary to determine whether there are adverse health effects of prenatal exposure to long-term, low levels of mercury and selenium. However, there are limited that reports on the association between mercury levels by selenium levels and birth size. Therefore, we examined whether maternal mercury levels during pregnancy had any effect on infant birth size, and size, and whether selenium levels influenced this relationship. Objectives To examine the association between mercury and selenium levels during pregnancy with infant birth size. Methods The Japan Environment and Children's Study is a prospective birth cohort conducted between 2011 and 2014. Total mercury levels and total selenium levels in maternal blood during the second and third trimesters were measured using Inductively Coupled Plasma-Mass Spectrometry. Birth weight and small-for-gestational-age were confirmed by medical records. Small-for-gestational-age was defined as birth weight below the 10th percentile according to standard percentile for gender, parity, and gestational age. Multiple linear and logistic regression analyses were used to examine the association between maternal mercury exposure and birth weight or small-for-gestational-age adjusted for confounders (including maternal age and body mass index pregnancy). Results Overall, 15,444 pregnant women were included in this study. Median (inter-quartile range) of blood mercury and selenium levels were 3.66 (2.59–5.18) ng/g and 170.0 (158.0–183.0) ng/g, respectively. Compared to infants of mothers with the highest blood selenium level, those of mothers with the lowest blood selenium level had neither a significant birth weight increase (9 g, 95% confidence interval: −6, 25) nor a significant odds ratio for small-for-gestational-age (0.903, 95% confidence interval: 0.748, 1.089). Compared to infants of mothers with the lowest blood mercury level, those of mothers with the highest blood mercury level had neither a significant birth weight reduction (−12 g, 95% confidence interval: −27, 4) nor a significant odds ratio for small-for-gestational-age (0.951, 95% confidence interval: 0.786, 1.150). Compared to infants of mothers with the lowest quartile of maternal blood mercury level, all infants of mothers with the highest quartile of maternal blood mercury level had a reduced birth head circumference of 0.073 cm (95% confidence interval: −0.134, −0.011). Conclusions There was no association between maternal blood mercury levels and small-for-gestational-age and birth weight among 15,444 pregnant women. In a Japanese population, which has a relatively higher blood mercury level than reported in Western population, reduced birth size was not found to be associated with blood mercury levels, with the exception of birth head circumference. Highlights • We examined association between maternal mercury and selenium with birth outcomes. • 15,444 pregnant Japanese women were included in the prospective birth cohort study. • An association between blood mercury and birth head circumference was found. • No association between blood selenium and birth size was found. • Increased small-for-gestational-age from blood mercury levels was not observed. [ABSTRACT FROM AUTHOR]

Abstract Objective Selenium seems to be a risk factor for diabetes mellitus (DM) in recent studies, opposite to the previous expectation that it may contribute to prevent DM. The authors aimed to ascertain the relationship between selenium and DM. Methods Data were collected from the National Health and Nutrition Examination Survey conducted from 2011 to 2014. A multivariate logistic regression analysis with adjustment for age, sex, race/ethnicity, hypertension, dyslipidemia and body mass index was conducted to evaluate the odds ratio for DM. Results The total number of subjects was 19,931. Large proportion of subjects were excluded due to young age (< 20 years) and missing data. The data of 3406 participants were analyzed, and a total of 604 had DM. In a multivariate logistic regression model, the increase of 10 μg/L in selenium increased the prevalence of DM by 12% (OR: 1.12; 95% CI: 1.06–1.18). Further analysis with 1:1 propensity score matching data with age and sex showed a similar results (OR: 1.08; 95% CI: 1.01–1.15). In addition, the restricted cubic spline regression showed a dose-dependent relationship between selenium level and DM. Subgroup analysis showed a dose-dependent relationship between selenium level and DM regardless of sex or race/ethnicity Conclusions This large population study clearly demonstrates a positive association between selenium level and DM. This finding could have implications for nutritional supplementation in clinical settings. [ABSTRACT FROM AUTHOR]

Background and aims: Gamma radiation is widely being used in medical-imaging centers. The aim of this study was to measure possible alterations in serum zinc and selenium levels among nuclear medicine staff. Methods: This cross-sectional study was carried out on 30 nuclear medicine staff as well as on 10 individuals as the control group. Blood samples (20 mL) were obtained from the participants and the serum specimens were isolated by centrifugation at 4000 rpm for 7 minutes. The samples were then used for measurement of zinc and selenium levels. Zinc and selenium levels were measured using atomic absorption spectroscopy (AAS) with a graphite furnace. The mean serum levels of zinc and selenium were compared using SPSS. Results: The mean level of zinc in the radiated group (70.91±14.46 μmol/L) was significantly lower than that in the control group (89.75±17.35 μmol/L) (P = 0.002). A negative significant correlation was found between the duration of exposure to radiation and zinc levels (P = 0.005). Furthermore, a negative significant relationship was observed between the mean radiation dose after 5 years and zinc concentration (P = 0.019). Non-significant difference was found in the mean level of selenium between control (1.71±0.35 μmol/L) and radiation (2.13±1.12 μmol/L) groups. Furthermore, no significant correlation was found between selenium level and exposure time. Conclusion: Based on the results, declined level of zinc can be considered as one of the possible mechanisms caused by gamma radiation on cells which may be associated with oxidative damage. Therefore, zinc therapy can be helpful for those who work at medical radiation centers; however, it merits further studies. [ABSTRACT FROM AUTHOR]

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Background Selenoprotein synthesis requires the reinterpretation of a UGA stop codon as one that encodes selenocysteine (Sec), a process that requires a set of dedicated translation factors. Among the mammalian selenoproteins, Selenoprotein P (SELENOP) is unique as it contains a selenocysteine-rich domain that requires multiple Sec incorporation events. Scope of review In this review we elaborate on new data and current models that provide insight into how SELENOP is made. Major conclusions SELENOP synthesis requires a specific set of factors and conditions. General significance As the key protein required for proper selenium distribution, SELENOP stands out as a lynchpin selenoprotein that is essential for male fertility, proper neurologic function and selenium metabolism. [ABSTRACT FROM AUTHOR]

Abstract: New data on the biological role of selenium in the body of mammals, inhabiting biogeochemical provinces with different selenium status are presented. The estimation of selenium and antioxidant status of animals is given, metabolic and clinical effects of inorganic and organic selenium-containing compounds use for the regulation of biochemical homeostasis and reproductive function of animals in conditions of biogeochemical selenium-deficient provinces are shown. [ABSTRACT FROM AUTHOR]

Objectives: Insulin resistance (IR) is one of the important factors associated with the clinical signs in patients with the polycystic ovary syndrome (PCOS). There are some studies which report a correlation between insulin resistance and trace elements. The present study primarily focuses on the investigation of serum selenium (Se) and zinc (Zn) levels as well as their relationship with insulin resistance in PCOS patients. Design: This is a case control study. Setting: The study was conducted at Fatemeh Zahra Infertility and Reproductive Health Research Center of Babol University of Medical Sciences, Babol, Iran. Methods: This study includes 60 women with PCOS (20-40 years old) and 90 healthy women. The PCOS group was divided into two sub-groups including insulin-resistant (n = 36) and non-insulin-resistant (n = 24) groups. Fasting blood sugar, fasting insulin, insulin resistance indexes and the serum levels of Se and Zn were measured in both groups. Results: Serum selenium levels were significantly lower in the patient group as compared with the control group (40.42 ± 21.12 VS 51.79 ± 15.65; p = .001). The mean zinc levels were also significantly lower in the PCOS women than in the controls (81.33 ± 24.28 VS 108.31 ± 63.29; p = .022). In addition, Zn levels in PCOS-IR were negatively correlated with the homeostatic model assessment for insulin resistance (r = -0.332, p = .048) and positively correlated with the glucose/insulin ratio (r = 0.354, p = .040) and insulin (r = 0.429, p = .009). Conclusion: The findings show decreased serum Se and Zn levels in the PCOS patients as compared to the controls. Additionally, the results confirm the correlation between zinc and insulin resistance. [ABSTRACT FROM AUTHOR]

Background: Selenium, an essential trace element, has been investigated as a potential cancer prevention agent. However, several studies have indicated that selenium supplementation may be associated with an increased risk of type 2 diabetes (T2D), although an equivocal relation of this nature requires confirmation.Objective: We examined the association between baseline plasma concentrations of selenium and the prevalence of T2D, as well as whether participant characteristics or intake of other antioxidant nutrients modified this relation.Methods: We conducted cross-sectional analyses of 1727 participants from the Selenium Trial, a randomized clinical trial of selenium supplementation for colorectal adenoma chemoprevention that had data for baseline selenium plasma concentrations, T2D status, and dietary intake. Logistic regression modeling was used to evaluate the associations between plasma selenium concentrations and prevalent T2D, adjusting for confounding factors. Heterogeneity of effect by participant characteristics was evaluated utilizing likelihood-ratio tests.Results: Mean ± SD plasma selenium concentrations for those with T2D compared with those without T2D were 143.6 ± 28.9 and 138.7 ± 27.2 ng/mL, respectively. After adjustment for confounding, higher plasma selenium concentrations were associated with a higher prevalence of T2D, with ORs (95% CIs) of 1.25 (0.80, 1.95) and 1.77 (1.16, 2.71) for the second and third tertiles of plasma selenium, respectively, compared with the lowest tertile (P-trend = 0.007). No significant effect modification was observed for age, sex, body mass index, smoking, or ethnicity. Increased odds of T2D were seen among those who were in the highest tertile of plasma selenium and the highest category of intake of β-cryptoxanthin (P-trend = 0.03) and lycopene (P-trend = 0.008); however, interaction terms were not significant.Conclusions: These findings show that higher plasma concentrations of selenium were significantly associated with prevalent T2D among participants in a selenium supplementation trial. Future work is needed to elucidate whether there are individual characteristics, such as blood concentrations of other antioxidants, which may influence this relation. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is the second leading cause of death among cancer in men. Trace elements are involved in many vital functions. Fluctuations in serum levels of these elements may reflect the occurrence and/or severity of PCa.This prospective case/control study aimed to assess the serum concentration of Cu, Zn and Se in patients with PCa (newly diagnosed and longstanding) and with benign prostatic hyperplasia (BPH). The study recruited 60 patients with PCa (30 newly diagnosed and 30 longstanding patients) and 30 patients with BPH. Other 30 healthy men were randomly selected to be a control group. Sera were separated from blood samples which were collected from each participant. Atomic absorption spectrophotometry was used to measure serum concentration of the studied trace elements. The newly diagnosed patients with PCa showed significantly (P<0.05) higher serum concentration of Cu (3.14±1.1 μg/ml) than each of longstanding group (1.48±0.91 μg/ml), BPH (0.96± 0.17μg/ml), and controls (1.1±0.23 μg/ml), while there were no significant differences between different groups regarding Zn concentration. In newly diagnosed patients, Se concentration was 58.2± 6.12 ng/ml) which is significantly lower than other groups (P<0.05). In longstanding patients, the concentration was relatively high (98.4± 12.38 ng/ml) and differed significantly from patients with BPH (72.4± 8.11 ng/ml) and non-significantly from controls (108.1±15.34 ng/ml) These results indicate that serum levels of Cu and Se undergo a marked change in newly diagnosed patients with PCa, and thus could be used as additional marker for this malignancy. [ABSTRACT FROM AUTHOR]

Japanese quails need about 70 per cent of production cost for feed and feeding. Nano minerals may reduce the feed cost by improving the productivity in poultry. This study was carried out to find out the effect of Nano-Selenium in diet at 0, 10, 15 and 25 ppm on the production performance of TANUVAS Nandanam Quail III from day old to 5 weeks of age utilizing 300 numbers in 4 treatments each with 3 replicates. Production parameters viz. weekly body weight, weight gain, feed intake, Feed Conversion Ratio (FCR) and livability were recorded. The results showed no significant difference between treatments. [ABSTRACT FROM AUTHOR]

A growing body of evidence indicates that exposure to selenium (Se) can cause neurotoxicity, and this can occur because of its interference with several neurotransmitter systems in humans and animals. Dopamine is a critical modulator of a variety of brain functions and a prime target for environmental neurotoxicants. However, effects of environmentally relevant concentrations of Se on dopaminergic system and its neurobehavioral effects are still largely unknown. For this purpose, we exposed zebrafish, a model organism, to different concentrations of dietary l -selenomethionine (control, 3.5, 11.1, 27.4, and 63.4 μg Se/g dry weight) for a period of 60 days. Cognitive performance of fish was evaluated using a plus maze associative learning paradigm. Oxidative stress, as the main driver of Se neurotoxicity, was assessed by measuring the ratio of reduced to oxidized glutathione (GSH:GSSG), lipid peroxidation (LPO) levels, and mRNA expression of several antioxidant enzymes in the zebrafish brain. Dopamine levels in the brain and the expression of genes involved in dopamine synthesis, storage, reuptake, metabolism, and receptor activation were examined. Moreover, transcription of several synaptic plasticity-related immediate-early and late response genes was determined. Overall, fish fed with the two highest concentrations of dietary Se displayed impaired associative learning. Se exposure also induced oxidative stress in the zebrafish brain, as indicated by a reduction in GSH:GSSG ratio, increased LPO levels, and up-regulation of antioxidant genes in fish treated with the two highest concentrations of Se. An increase in brain dopamine levels associated with altered expression of dopaminergic cell markers was evident in different treatment groups. Moreover, Se exposure led to the down-regulation of immediate-early and late response genes in fish that exhibiting learning impairment. Taken together, the results of this study imply that the induction of oxidative stress and dysregulation of dopaminergic neurotransmission may underlie Se-induced impairment of associative learning in zebrafish. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the in vivo effects of ochratoxin A (OTA) and/or lycopene on the levels of selenium, zinc, and copper in the liver, kidneys, and testes of male Sprague-Dawley rats. The rats were treated with OTA (0.5 mg kg-1 day-1) and/or lycopene (5 mg kg-1 day-1) by gavage for 7 or 14 days. Trace element levels were measured by atomic absorption spectrometry. OTA significantly lowered selenium (20 % in the liver, 17 % in the kidney, and 40 % in the testis), zinc (24 % in the liver, 23 % in the kidney, and 26 % in the testis), and copper levels (40 % in the liver and 10 % in the kidney). Lycopene alone did not affect the trace element levels in any of the organs. In combination with OTA, however, it significantly restored liver, kidney, and testis selenium and zinc levels compared to the group treated with OTA alone. Our results have confirmed that depletion of trace elements in different organs is one of the mechanisms of action of OTA. They also suggest that lycopene interferes with this depleting effect and restores trace element levels, the implications of which need to be further investigated. [ABSTRACT FROM AUTHOR]

Background: Observational studies have reported an inverse relationship between selenium status (blood or toenail) and the risk of laryngeal cancer; however, the impact of low serum selenium level on survival has not been evaluated. Methods: We conducted a prospective study of 296 patients diagnosed with laryngeal cancer in Szczecin, Poland. Serum selenium was measured at diagnosis and prior to treatment. Patients were followed from the date of diagnosis to death at five years. Vital status was obtained by linkage to the Polish National Death Registry. Results: The five-year survival after diagnosis was 82.0% (95% CI: 68% to 91%) for individuals in the highest quartile of serum selenium (> 66.8 μg/L) and was 28.6% (95% CI 19% to 42%) for individuals in the lowest quartile (<50.0 μg/L). In an age- and sex-adjusted analysis, the hazard ratio (HR) for death from all causes was 7.01 (95% CI 3.81 to 12.9) for patients in the lowest quartile of serum selenium, compared to those in the highest quartile. The corresponding multivariate HR was 3.07 (95% CI 1.59 to 5.94). Conclusions: This study suggests that a selenium level in excess of 70 μg/L is associated with improved outcome among patients undergoing treatment for laryngeal cancer. Further studies are needed to evaluate if selenium supplementation to achieve this level might improve overall prognosis. [ABSTRACT FROM AUTHOR]

Scientific studies of foreign and domestic scientists convincingly proved, that selenium is a vitally necessary microelement with a wide spectrum of biological action. Despite the small concentrations in the body, selenium has unique multi-functional functions - catalytic, structural, regulatory, - in the process of which he activates the action of many enzymes, vitamins, hormones and thus ensure the normal functioning of various biological systems, the implementation of numerous physiological and biochemical reactions in the living organism. The biochemical functions of selenium are not determined by the trace element itself, but by selenium proteins that contain the selenocysteine residue as an integral part of their active center. For today more than thirty such specific selenoproteins have been identified and identified in their pure form, the main of which are glutathione peroxidase, thioredoxine reductase, 5-iodothyronine deiodinase, selenoprotein P, and others. Glutathione peroxidases are the main antioxidant enzymes involved in peroxide oxidation of lipids in biological membranes, catalyze the reduction of hydrogen peroxide and almost all organic hydroperoxides, thus protecting the body's cells from reactive oxygen species. Thioredoxin reductase restores the SH-group in a specific thioredoxin protein, which is responsible for maintaining the oxidative-reduction potential in the cell, affects the products of eicosanoids, modulates the processes of inflammation and chemotaxis. Dayon dentiases of the I-III type are responsible for the exchange of thyroid hormones, are involved in the transformation of the "prohormone" of thyroxine into a more active form of influence - triiodothyronine, regulate and maintain a constant concentration of other thyroid hormones. Selenoprotein P is involved in the transport of selenium to various tissues, acts as an agent that helps neutralize toxic effects and remove heavy metals (Pt, Hg), protecting Leydig cells from active forms of oxygen, indirectly affects the synthesis of testosterone and the processes of spermatogenesis. Selenium plays an important role in the functioning of a nonspecific and specific immune system, prevents mutation of viruses and the emergence of new high-pathogenic strains. Selenium inhibits the formation of hyperplastic and enzyme-altered cells caused by aflatoxin B1 or T- 2 toxin, capable of destroying molds producing aflatoxins. Selenium is involved in the formation of mechanisms that determine the reproductive function, in particular, stimulates the hormonal function of the fetoplacental complex towards increasing the synthesis of estrogens, activates childbirth and postnatal involutional processes in the organs of the reproductive system, maintains the active function and structural integrity of the sperm, and thereby ensures their high mobility, preservation, and active penetration into the egg cell. The discovery of the biological properties of selenium has become the basis for its use initially in the prophylaxis and treatment of many illnesses and pain symptoms associated with the deficiency of this trace element, and subsequently - in order to increase the productivity of farm animals and poultry, improve the quality of their products and produce dietary food products of a functional purpose, with bio-correcting effect. Despite the considerable amount of conducted research, mechanisms of action of selenium on some metabolic processes in the body are still not fully clarified. [ABSTRACT FROM AUTHOR]

Data from National Health and Nutrition Examination Survey for 2013-2014 were used to compare observed levels of selected metals in blood, serum, and urine among US adults aged ≥20 years for exclusive cigar, cigarettes, and e-cigarette users. Adjusted geometric means for e-cigarette users were found to be higher than for cigar users for blood manganese (10.3 vs. 7.9 µg/L, p = 0.02). Cigar users were found to have lower adjusted geometric means than cigarette users for urine cobalt (0.22 vs. 0.4 µg/L, p = 0.04) and urine antimony (0.03 vs. 0.06 µg/L, p = 0.03). Adjusted levels of blood selenium, serum copper, selenium, and zinc, and urine arsenic, barium, molybdenum, tin, strontium, thallium, tungsten, and uranium were found to be comparable among cigarettes only, cigar only, and electronic cigarettes only users. However, irrespective of the comparative levels of these metals among cigar, cigarette, and e-cigarette users, focus must be to assess the short- and long-term health effects of the exposure to these metals particularly nanoparticles via inhalation from e-cigarette aerosols. [ABSTRACT FROM AUTHOR]

An experiment was conducted to study the effects of two sources and dietary levels of selenium (Se) on performance, Se concentration and glutathione peroxidase activity in plasma and liver ofpiglets post weaning. A total of 126 weaned pigs male and female Large White x Landrace, at average body weight of 7.2±0.67kg were allotted to seven treatments in a randomized block design, with two Se sources (organic and inorganic), inclusion levels, two levels for the inorganic source (0.30 and 0.60ppm) and four for the organic source (0.15, 0.30, 0.45 and 0.60ppm) and one control diet without Se supplementation containing 0.095ppm, and six replicates of three animals per pen. The experimental period was 35 days post-weaning. The organic source contained 0.2067% (Se-yeast), and the inorganic 45.86% (sodium selenite) analyzed. Piglets that received supplemental Se had lower feed intake compared to those not supplemented. Furthermore, feed conversion was better with dietary supplementation of Se, and the organic source was better than the inorganic source at level of 0.30ppm. Plasma concentration of Se was higher (35.53%) in animals receiving dietary supplementation of this mineral, regardless of the sources studied. There was no effect of sources on plasma and hepatic Se, with the lowest values observed for the non-supplementation and organic Se at dietary level of 0.15ppm. There was a linear reduction of plasma GSH-Px activity with increased supplementation levels of organic Se, and the hepatic GSH-Px activity increased linearly with the increased supplementation, regardless of the source studied. [ABSTRACT FROM AUTHOR]

Inuit in Canada have high selenium intake from the consumption of country food such as fish and marine mammals. The health consequence is not known. This study examines the association between blood selenium concentration and prevalence of stroke among Canadian Inuit. The International Polar Year Inuit Health Survey was conducted in 2007–2008. Among the 2077 adults participants (≥18 years old) who completed a questionnaire and gave blood samples, 49 stroke cases were reported, 31 of which were from women. The crude prevalence of stroke was 2.4% in the participants. Participants with stroke had lower blood selenium (geometric mean: 260 μg/L vs. 319 μg/L) and dietary selenium (144 μg/day vs. 190 μg/day) compared to individuals without stroke. Participants with high blood/dietary selenium exposure (quartiles 3 and 4) had a lower prevalence of stroke compared to those with low selenium exposure (quartile 1). The adjusted odds ratio ranged from 0.09 to 0.25 among subgroups (e.g. age, sex, and blood mercury). An L-shaped relationship between prevalence of stroke with blood and dietary selenium was observed, based on the cubic restricted spline and segmented regression analyses. The estimated turning points of the L-shaped curve for blood selenium and dietary selenium were 450 μg/L and 350 μg/day, respectively. Below the turning points, it was estimated that each 50-μg/L increase in blood selenium was associated with a 38% reduction in the prevalence of stroke, and each 50-μg/day increase in dietary selenium was associated with a 30% reduction in the prevalence of stroke. In conclusion, blood and dietary selenium are reversely associated with the prevalence of stroke in Inuit, which follows an L-shaped relationship. Whether this relationship applies to other population needs further investigation. [ABSTRACT FROM AUTHOR]

Due the long-term nature of joint tissue remodeling processes, knee structures including meniscus and anterior cruciate ligament (ACL) can be a model for studying the bioaccumulation of mercury (Hg) and selenium (Se). The accumulation and retention of Hg in human tissues can have a negative effect on the proper functioning of homeostasis-affecting organisms. A factor of chronic poisoning with Hg forms is probably the Se:Hg ratio in tissues. Se:Hg molar ratios below one may increase Hg toxicity potentials, while molar ratios that approach or exceed one effectively may protect against Hg toxicity. Therefore, the aim of the study was to determine total mercury (THg), Se, and Se:THg molar ratios in the cartilage, meniscus and ACL of patients with osteoarthritis (OA) from northwestern Poland. In all studied samples (n = 95), we observed higher Se than THg concentration. Taking into consideration the biological factors, we found significantly higher THg levels in the cartilage of women, patients under 65 years of age, patients without hypertension and in the ACL of patients with spinal degenerative disease. We found higher Se levels in the meniscus in women than in men. In all studied parts of the knee joint, we found the Se:THg molar ratio higher than one, which suggests that the joint forming structures are not much exposed to THg. Moreover the results reported here may provide a basis for establishing reference values for the meniscus and ACL in patients with OA who had undergone knee replacement surgery. [ABSTRACT FROM AUTHOR]

Project Varicocele is an abnormal tortuosity and distension of the veins of the pampiniform plexus in the spermatic cord. It is the most common surgically correctable cause of male infertility. Several studies have revealed the effects of increased oxidative stress on serum, semen, and testicular tissues in patients with varicocele or in animal models. The aim of this study was to investigate the effects of sodium selenite on testicular damage induced by experimental left varicocele in male Wistar rats. Procedure In the present study, the effects of oral administration of sodium selenite (at doses of 0.05, 0.1, 0.2, and 0.4 mg/kg bw) were assessed in normal and varicocelized rats. Results The varicocelized control rats showed decrease in sperm quality parameters, decreased activity of testes CAT, GPX and SOD, increased levels of MDA, and damage in testicular architecture. Administration of sodium selenite significantly reduced these changes to nearly normal levels, but did not change these parameters in normal rats. Histopathological studies further confirmed the protective effects of sodium selenite on varicocele-induced testicular damage in rats. Administrations of sodium selenite did not change these parameters in normal rats. Conclusions Taken together, the results of this study suggest that sodium selenite treatment may have beneficial effect on the testes of varicocelized rats. [ABSTRACT FROM AUTHOR]

To explore the metabolism of T-2 toxin in human chondrocytes (HCs) and determine the impact of selenium supplementation. For determination of cytotoxicity using the MTT assay, optical density values were read with an automatic enzyme-linked immunosorbent assay reader at 510 nm. Cell survival was calculated and the cytotoxicity estimated. To identify the metabolites of T-2 toxin, the medium supernatants and C28/I2 cells were analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) separately. For HPLC–MS/MS, the mobile phase A was water and phase B was 98% methanol. The gradient for the elution was: 0–0.5 min, 50% of B; 0.5–2.0 min, 100% of B; 2.0–3.5 min, 100% of B; 3.6–6 min, 50% of B. T-2 toxin increased the toxicity to C28/I2 cells significantly in a dose- and time-dependent manner (viability range 91.5–22.0%). Supplementation with selenium (100 ng/mL) could increase the cell viability after the 24 h incubation. The concentration of T-2 toxin in the cell medium decreased from 20 to 6.67 ± 1.02 ng/mL, and the concentration of HT-2 toxin increased from 0 to 6.88 ± 1.23 ng/mL during the 48 h incubation, whereas the relative concentration of T-2 toxin in cells increased from 0 to 12.80 ± 1.84 ng/g. Supplementary selenium in the HCs cultures reduced the cytotoxicity induced by T-2 toxin significantly, and was associated with rapid conversion of T-2 toxin in the culture medium to HT-2 toxin. T-2 toxin was more toxic to HCs than HT-2 toxin at equivalent concentrations. HT-2 toxin was a detectable metabolite of T-2 toxin in cultured HCs, and selenium enhanced the metabolic conversion of T-2 toxin, reducing its cytotoxicity to HCs. [ABSTRACT FROM AUTHOR]

Increased oxidative stress in the brain during the course of Alzheimer's disease (AD) leads to an imbalance of antioxidants and formation of free radical reaction end-products which may be detected in blood as fluorescent lipofuscin-like pigments (LFPs). The aim of this study was to evaluate and compare LFPs with plasma selenium concentrations representing an integral part of the antioxidant system. Plasma samples from subjects with AD dementia (ADD; n=11), mild cognitive impairment (MCI; n=17) and controls (n=12), were collected. The concentration of selenium was measured using atomic absorption spectroscopy. LFPs were analyzed by fluorescence spectroscopy and quantified for different fluorescent maxima and then correlated with plasma selenium. Lower levels of selenium were detected in MCI and ADD patients than in controls (P=0.003 and P=0.049, respectively). Additionally, higher fluorescence intensities of LFPs were observed in MCI patients than in controls in four fluorescence maxima and higher fluorescence intensities were also observed in MCI patients than in ADD patients in three fluorescence maxima, respectively. A negative correlation between selenium concentrations and LFPs fluorescence was observed in the three fluorescence maxima. This is the first study focused on correlation of plasma selenium with specific lipofuscin-like products of oxidative stress in plasma of patients with Alzheimer's disease and mild cognitive impairment. [ABSTRACT FROM AUTHOR]

The current NRC selenium (Se) requirement for turkeys is 0.2 μg Se/g diet. We previously fed turkey poults a Se-deficient diet (0.005 μg Se/g) supplemented with 10 graded levels of Se (0, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0 μg Se/g as Na2SeO3, 5/treatment) for 4 wk, and found that the minimum dietary Se requirement was 0.3 μg Se/g based on selenoprotein enzyme activity in blood, liver, gizzard and pancreas. Because the turkey is primarily a production animal, we expanded this analysis to kidney, heart, breast and thigh. Se concentrations in Se-deficient poults were 5.0, 9.8, 33, and 15% of levels in poults fed 0.4 μg Se/g in liver, kidney, thigh and breast, respectively. Increasing Se supplementation resulted in hyperbolic response curves for all tissues; breakpoint analysis indicated minimum Se requirements of 0.34–0.36 μg Se/g based on tissue Se levels in liver, kidney and thigh. Similarly, GPX1 activity in muscle tissues and kidney responded hyperbolically to increasing dietary Se, reaching well-defined plateaus with breakpoints at 0.30–0.36 μg Se/g. Minimum Se requirements based on GPX4 activity were 0.30–0.32 μg Se/g for breast and thigh. Selenoprotein transcript expression decreased significantly in Se deficiency for only 2, 3, 5, and 6 mRNA in breast, thigh, heart, and kidney, respectively, out of 24 known avian selenoproteins. Se response curves for regulated selenoprotein transcripts were hyperbolic, and reached well-defined plateaus with breakpoints in a narrow range of 0.08–0.19 μg Se/g. No selenoprotein transcript was altered by supernutritional Se. In summary, these results clearly indicate that the NRC dietary Se requirement should be raised to 0.4 μg Se/g, at least for poults, to meet the nutritional needs of the young turkey. The Se response curve plateaus further show that limits for turkey supplementation with selenite could safely be raised to 0.5 μg Se/g diet. [ABSTRACT FROM AUTHOR]

This study investigated whether plasma selenium levels modified the risk for prostate cancer (PC) related to arsenic exposure. We conducted a case-control study that included 318 PC patients and 318 age-matched, healthy control subjects. Urinary arsenic profiles were examined using HPLC-HG-AAS and plasma selenium levels were measured by ICP-MS. We found that plasma selenium levels displayed a significant dose-dependent inverse association with PC. The odds ratio (OR) and 95% confidence interval (CI) for PC was 0.07 (0.04–0.13) among participants with a plasma selenium level >28.06 μg/dL vs. ≤19.13 μg/dL. A multivariate analysis showed that participants with a urinary total arsenic concentration >29.28 μg/L had a significantly higher OR (1.75, 1.06–2.89) for PC than participants with ≤29.89 μg/L. The combined presence of a low plasma selenium level and a high urinary total arsenic concentration exponentially increased the OR for PC, and additively interacted with PSA at levels ≥20 ng/mL. This is the first epidemiological study to examine the combined effects of plasma selenium and urinary total arsenic levels on the OR for PC. Our data suggest a low plasma selenium level coupled with a high urinary total arsenic concentration creates a significant risk for aggressive PC. [ABSTRACT FROM AUTHOR]

Introduction Several studies have shown an inverse relationship between selenium status and cardiovascular health, although epidemiologic evidence yielded by the randomized trials did not find a beneficial effect of selenium administration. The aim of this study was to analyze the association between serum selenium levels and lipid profile adjusted by age, sex and other associated factors among a general adult population in Spain. Materials and methods We recruited 372 hospital employee volunteers (60 men and 312 women) with a mean age of 47 (SD: 10.9), whom were given a standardized questionnaire. Serum selenium concentration was measured by electrothermal atomization atomic absorption spectrometry. Serum copper and zinc concentrations were measured using flame atomic absorption spectrometry. Results The mean of serum selenium was 79.5 μg/L (SD: 11.7) with no sex-dependent differences. In the multivariate linear regression analysis, the associated factors with the mean levels of selenium were: age (β = 0.223; CI 95%: 0.101–0.345), p < 0.001; widowhood (β = −9.668; CI 95%: −17.234 to −2.102), p = 0.012; calcium supplements (β = 3.949; CI 95%: 0.059–7.838), p = 0.047; zinc (β = 0.126; CI 95%: 0.013–0.238), p = 0.028 and glucose (β = 0.172; CI 95%: 0.062- 0.281), p = 0.002; Participants with serum selenium ≥ 79.5 μg/L were 1.98 (OR = 1.98; CI 95% 1.17–3.35; p = 0.011) and 2.04 times (OR = 2.04; CI 95% 1.06–3.97; p = 0.034) more likely to have cholesterol ≥200 mg/dL and LDL-c ≥100 mg/dL respectively than those with serum selenium <79.5 μg/L. Conclusions Higher selenium was positively associated with increased total and LDL cholesterol but not with HDL-c and triglycerides. More studies are needed in order to confirm the lower serum selenium findings in widows. [ABSTRACT FROM AUTHOR]

Selenium is involved in the complex system of defense against oxidative stress in diabetes through its biological function of selenoproteins and the antioxidant enzyme. A case-control study was carried out to determine the association of plasma selenium with oxidative stress and body composition status presented in Type 2 Diabetes Mellitus (T2DM) patient and healthy control. This study involved 82 newly diagnosed T2DM patients and 82 healthy controls. Plasma selenium status was determined with Graphite Furnace Atomic Absorption Spectrometry. Body Mass Index, total body fat and visceral fat was assessed for body composition using Body Composition Analyzer (TANITA). Oxidative DNA damage and total antioxidant capacity were determined for oxidative stress biomarker status. In age, gender and BMI adjustment, no significant difference of plasma selenium level between T2DM and healthy controls was observed. There was as a significant difference of Oxidative DNA damage and total antioxidant capacity between T2DM patients and healthy controls with tail DNA% 20.62 [95% CI: 19.71,21.49] (T2DM), 17.67 [95% CI: 16.87,18.56] (control); log tail moment 0.41[95% CI: 0.30,0.52] (T2DM), 0.41[95% CI: 0.30,0.52] (control); total antioxidant capacity 0.56 [95% CI: 0.54,0.58] (T2DM), 0.60 [95% CI: 0.57,0.62] (control). Waist circumference, BMI, visceral fat, body fat and oxidative DNA damage in the T2DM group were significantly lower in the first plasma selenium tertile (38.65–80.90 μg/L) compared to the second (80.91–98.20 μg/L) and the third selenium tertiles (98.21–158.20 μg/L). A similar trend, but not statistically significant, was observed in the control group. [ABSTRACT FROM AUTHOR]

Objective Wide variation exists in ovarian cancer incidence rates suggesting the importance of environmental factors. Due to increasing environmental pollution, trace elements and heavy metals have drawn attention in studies defining the etiology of cancer, but scant data is available for ovarian cancer. Our aim was to compare the tissue concentrations of lead, selenium and nickel in epithelial ovarian cancer, borderline tumor and healthy ovarian tissues. Methods The levels of lead, selenium and nickel were estimated using atomic absorption spectrophotometry in formalin-fixed paraffin-embedded tissue samples. Tests were carried out in 20 malignant epithelial ovarian cancer, 15 epithelial borderline tumor and 20 non-neoplastic healthy ovaries. Two samples were collected for borderline tumors, one from papillary projection and one from the smooth surface of cyst wall. Results Pb and Ni concentrations were found to be higher both in malignant and borderline tissues than those in healthy ovaries. Concentrations of Pb and Ni in malignant tissues, borderline papillary projections and capsular tissue samples were not different. Comparison of Se concentrations of malignant, borderline and healthy ovarian tissues did not reveal statistical difference. Studied metal levels were not found to be different in either papillary projection or in cyst wall of the borderline tumors. Conclusions This study revealed the accumulation of lead and nickel in ovarian tissue is associated with borderline and malignant proliferation of the surface epithelium. Accumulation of these metals in epithelial ovarian cancer and borderline ovarian tumor has not been demonstrated before. [ABSTRACT FROM AUTHOR]

Ultraviolet B (UVB medium wave, 280-315 nm) induces cellular oxidative damage and apoptosis by producing reactive oxygen species (ROS). Glutathione peroxidase functions as an antioxidant by catalyzing the reduction of hydrogen peroxide, the more important member of reactive oxygen species. A human selenium-containing single-chain variable fragment (se-scFv-B3) with glutathione peroxidase activity of 1288 U/μmol was generated and investigated for its antioxidant effects in UVB-induced oxidative damage model. In particular, cell viability, lipid peroxidation extent, cell apoptosis, the change of mitochondrial membrane potential, caspase-3 activity and the levels of intracellular reactive oxygen species were assayed. Human se-scFv-B3 protects NIH3T3 cells against ultraviolet B-induced oxidative damage and subsequent apoptosis by prevention of lipid peroxidation, inhibition of the collapse of mitochondrial membrane potential as well as the suppression of the caspase-3 activity and the level of intracellular ROS. It seems that antioxidant effects of human se-scFv-B3 are mainly associated with its capability to scavenge reactive oxygen species, which is similar to that of the natural glutathione peroxidase. [ABSTRACT FROM AUTHOR]

Background: Selenium (Se) and zinc (Zn) have antioxidant and anticancer properties. Objective: The aim of this study was to evaluate the serum levels of Se and Zn and the correlation between the levels of these two elements with risk of incidence of esophageal cancer (EC) and gastric cancer (GC). Materials and Methods: In a case-control study, we selected sixty patients with GC or EC as the intervention group and 120 age-matched individuals as the control group. Exclusion criteria were the individuals with kidney and liver failure and the consumer of dietary supplements such as Se and Zn. Measurement of serum Se was done in a graphite furnace system and atomic absorption device of Varian and of serum Zn was done by a flame photometer system (flame) and atomic absorption device of Varian. Results: In thirty patients of ECs, 90% were squamous cell carcinoma and 10% adenocarcinoma, and out of thirty patients of GCs, 90% were intestinal type and 10% diffuse type. The level of two elements in cancer patients was lower than the control group (P < 0.05). There was no significant different between two cancer groups for level of Se and Zn, but there was a significant difference between the control group with two other groups. Conclusion: Our study confirmed the findings from previous prospective studies and randomized trials that reducing of lower levels of Se and Zn can effect on incidence of cancer. [ABSTRACT FROM AUTHOR]

Batch culture of Candida utilis CCTCC M 209298 for the preparation of selenium (Se)-enriched yeast was carried out under different pH conditions, and maximal intracellular organic Se and glutathione (GSH) contents were obtained in a moderate acid stress environment (pH 3.5). In order to elucidate the physiological mechanism of improved performance of Se-enriched yeast by acid stress, assays of the key enzymes involved in GSH biosynthesis and determinations of energy supply and regeneration were performed. The results indicated that moderate acid stress increased the activity of γ-glutamylcysteine synthetase and the ratios of NADH/NAD and ATP/ADP, although no significant changes in intracellular pH were observed. In addition, the molecular mechanism of moderate acid stress favoring the improvement of Se-yeast performance was revealed by comparing whole transcriptomes of yeast cells cultured at pH 3.5 and 5.5. Comparative analysis of RNA-Seq data indicated that 882 genes were significantly up-regulated by moderate acid stress. Functional annotation of the up-regulated genes based on gene ontology and the Kyoto Encyclopedia of Genes and Genome (KEGG) pathway showed that these genes are involved in ATP synthesis and sulfur metabolism, including the biosynthesis of methionine, cysteine, and GSH in yeast cells. Increased intracellular ATP supply and more amounts of sulfur-containing substances in turn contributed to NaSeO assimilation and biotransformation, which ultimately improved the performance of the Se-enriched C. utilis. [ABSTRACT FROM AUTHOR]

Objective: To correlate serum selenium levels with hypertensive disorders of pregnancy (HDP) in a selected population and evaluate this mineral as a possible protective factor.Methods: This case-control study included 32 normotensive, 20 hypertensive (chronic and gestational hypertension), and 38 preeclamptic pregnant women. All patients were recruited from antenatal or obstetric admissions of a tertiary hospital in Brazil. Serum selenium was measured at the time of inclusion. Patients were followed up until hospital discharge after delivery.Results: Groups did not differ with regard to maternal age, ethnicity, educational attainment, parity, or smoking prevalence. Normotensive patients had lower body mass index and were included in the study earlier. These patients also had a higher prevalence of comorbidities other than hypertension. Continuous use of medication and a history of HDP in previous pregnancies were more common in preeclamptic patients. Serum selenium levels were not significantly different between groups, with an average of 56.4 ± 15.3 μg/L in the control group, 53.2 ± 15.2 μg/L in the hypertension group, and 53.3 ± 16.8 μg/L in the preeclampsia group (p = 0.67). Among patients with preeclampsia, 52.6% had the severe form. Serum selenium levels in these patients also did not differ significantly from those of controls (p = 0.77). Preeclampsia was associated with earlier termination of pregnancy and lower birth weight (p < 0.05). There were no significant differences across groups in other outcomes of interest.Conclusion: Serum selenium levels did not differ significantly between groups. Thus, we could not establish whether selenium is a protective factor against these conditions. [ABSTRACT FROM AUTHOR]

Reindeer (Rangifer tarandus tarandus) are important livestock for arctic and subarctic herders, including those in North America, but as climate change affects traditional herding practices, alternative methods of rearing (such as captive rearing) will likely become common. Proper nutrition is critical in livestock production, but there is minimal information available on circulating nutrient concentrations in reindeer, who are adapted to a unique climate. This study looks at 2 important antioxidants. Blood and serum were taken from female reindeer from three herds: a freeranging herd from the Seward Peninsula, Alaska (AK), during the summer, and two captive herds (one in Fairbanks, AK and one in Upstate New York (NY) during the summer and winter. Selenium (Se) and vitamin E concentrations were described stratified on season (when possible), location, and management practices (captive or free range). Herd mean values across seasons for Se ranged from 2.42 to 4.88 μmol/L. Herd mean values across seasons for vitamin E ranged from 5.27 to 6.89 µmol/L. [ABSTRACT FROM AUTHOR]

Selenium supplementation of the diets of rodents has consistently been shown to suppress mammary carcinogenesis and some, albeit not all, human epidemiological studies have indicated an inverse association between selenium and breast cancer risk. In order to better understand the role selenium plays in breast cancer, 30 samples of tumor tissue were obtained from women with breast cancer and analyzed for selenium concentration, the levels of several selenium-containing proteins and the levels of the MnSOD anti-oxidant protein. Polymorphisms within the genes for these same proteins were determined from DNA isolated from the tissue samples. There was a wide range of selenium in these tissues, ranging from 24 to 854 ng/gm. The selenium levels in the tissues were correlated to the genotype of the SELENOP selenium carrier protein, but not to other proteins whose levels have been reported to be responsive to selenium availability, including GPX1, SELENOF and SBP1. There was an association between a polymorphism in the gene for MnSOD and the levels of the encoded protein. These studies were the first to examine the relationship between selenium levels, genotypes and protein levels in human tissues. Furthermore, the obtained data provide evidence for the need to obtain data about the effects of selenium in breast cancer by examining samples from that particular tissue type. [ABSTRACT FROM AUTHOR]

We analysed sodium (Na), copper (Cu) and selenium (Se) levels in human semen and glutathione peroxidase activity (GPx) in seminal plasma and examined their relationships with sperm quality. Semen samples were obtained from men (n=168) undergoing routine infertility evaluation. The study design included two groups based on standard ejaculate parameters: Group I (n=39) with normal ejaculates (normozoospermia) and Group II (n=129) with a pathological spermiogram. Se concentration (but not Na or Cu) and GPx activity were significantly higher in normozoospermic males than in those with a pathological spermiogram and also in males with correct sperm motility and normal sperm morphology than in asthenozoospermic and teratozoospermic males. There were significant correlations between sperm motility, Se and GPx, between rapid progressive motility and Cu, between sperm motility and Na, between normal sperm morphology and Se and Cu and between sperm concentration and Cu and GPx. Significant correlations were found between Na and Cu, between Na and Se and between Cu and Se in human semen in relation to alcohol consumption and tobacco use. Na, Cu, Se and GPx are related to sperm characteristics and male fertility and their survey could improve male infertility diagnosis. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the case study of a 35-year-old man with four-month history of dystrophy of all nails and one-month history of hair loss and fragility of hair all over his body, in which the patient was diagnosed with selenium toxicity.

Background: The association between serum selenium level and gestational diabetes mellitus (GDM) is controversial. The aim of our study was to systematically review available literature linking selenium to GDM for a comprehensive understanding of the relationship between serum selenium level and GDM in human. Methods: PubMed, The Cochrane Library and Medline were searched for studies published up to August 2016. Manual searches of references of the relevant original studies were carried out. Pooled estimates were measured using the fixed or random effect model. Overall effect was reported in a standard mean difference (SMD). All data were analyzed with Review Manager 5.3 and Stata 12.0. Results: Of 44 references reviewed, seven studies involving 569 patients met our inclusion criteria and contributed to meta-analysis. All the studies were used to evaluate the relationship between serum selenium level and GDM. Selenium level was significantly lower in women with GDM than those without GDM (SMD = -1.17; 95% CI: -1.98 to -0.35, P = 0.005). Subgroup analysis showed that such trend was consistent within the non-Caucasian population (Asia: SMD = -2.82; 95% CI: -5.21 to -0.43, P = 0.02; Africa: SMD = -0.56; 95% CI: -1.07 to -0.05, P = 0.03) and in the third trimester (SMD = -1.78; 95% CI: -3.04 to -0.52, P = 0.006), but not within the Caucasian population (Europe: SMD = -0.6; 95% CI: -1.98 to 0.78, P = 0.39) or in the second trimester (SMD = -0.68; 95% CI: -1.6 to 0.25, P = 0.15). Conclusions: The available evidences suggested that serum selenium level was lower in women with GDM than those with normal glucose tolerance, especially within the non-Caucasian population and in the third trimester. However, well-designed prospective studies are needed to understand dynamic associations between selenium status and GDM risk. [ABSTRACT FROM AUTHOR]

Selenium, an essential micronutrient known for its cancer prevention properties, is incorporated into a class of selenocysteinecontaining proteins (selenoproteins). Selenoprotein H (SepH) is a recently identified nucleolar oxidoreductase whose function is not well understood. Here we report that seph is an essential gene regulating organ development in zebrafish. Metabolite profiling by targeted LC-MS/MS demonstrated that SepH deficiency impairs redox balance by reducing the levels of ascorbate and methionine, while increasing methionine sulfoxide. Transcriptome analysis revealed that SepH deficiency induces an inflammatory response and activates the p53 pathway. Consequently, loss of seph renders larvae susceptible to oxidative stress and DNA damage. Finally, we demonstrate that seph interacts with p53 deficiency in adulthood to accelerate gastrointestinal tumor development. Overall, our findings establish that seph regulates redox homeostasis and suppresses DNA damage. We hypothesize that SepH deficiency may contribute to the increased cancer risk observed in cohorts with low selenium levels. [ABSTRACT FROM AUTHOR]

Thirty six New Zealand White (NZW) rabbit bucks were divided into three experimental groups were used to assess effect of age and administration of vitamin E with selenium on some testicular traits, hematological and biochemical parameters. Group 1: young age (4-5 months), Group 2: middle age (9-10 months) and Group 3: old age (20-24 months). Each group was divided into two subgroups (treatment and control). Treated group was subcutaneously injected with vitamin E and selenium weekly for twelve weeks, while the other was given saline solution and served as control. Blood samples were collected at 6th and 12th weeks of experiment. Some hematological and biochemical parameters were determined in blood serum. At the end of experiment (12th weeks), animals were slaughtered and the two testes and the epididymis of each buck were weighed. The obtained results showed that hematological parameters were not significantly affected by age except for hemoglobin and white blood cells values. Vitamin E and selenium insignificantly increased red blood cells count, hemoglobin, packed cell volume and white blood cells count and decreased neutrophils (N), lymphocytes (L) and N/L ratio. Age had a significant effect on total protein, glucose and cholesterol. Vitamin E and selenium did not affect blood biochemical parameters. In addition, age of bucks had significant effects on body weight, testes weight and sperm output. Vitamin E and selenium had significant effects on total motile sperm per gram testis. Generally, administration of vitamin E and selenium improved testes weight and sperm output. Middle age bucks were superior in most studied parameters than young and old age groups. Treatment of young group with vitamin E and selenium improved their total sperm output to comparable levels of that observed in control old and middle groups which could enhance their earlier usage in rabbit farms. [ABSTRACT FROM AUTHOR]

Purpose: Understanding of the etiology and pathogenesis of pancreatic cancer (PaCa) is still insufficient. This study evaluated the associations between concentrations of selenium (Se) and copper (Cu) in the serum of PaCa patients. Materials and Methods: The study included 100 PaCa patients and 100 control subjects from the same geographical region in Poland. To determine the average concentration of Se, Cu, and ratio Cu:Se in the Polish population, assay for Se and Cu was performed in 480 healthy individuals. Serum levels of Se and Cu were measured using inductively coupled plasma mass spectrometry. Results: In the control group, the average Se level was 76 µg/L and Cu 1,098 µg/L. The average Se level among PaCa patients was 60 µg/L and the mean Cu level was 1,432 µg/L. The threshold point at which any decrease in Se concentration was associated with PaCa was 67.45 µg/L. The threshold point of Cu level above which there was an increase in the prevalence of PaCa was 1,214.58 µg/L. In addition, a positive relationship was observed between increasing survival time and Se plasma level. Conclusion: This retrospective study suggests that low levels of Se and high levels of Cu might influence development of PaCa and that higher levels of Se are associated with longer survival in patients with PaCa. The results suggest that determining the level of Se and Cu could be incorporated into a risk stratification scheme for the selection and surveillance control examination to complement existing screening and diagnostic procedures. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the levels of selenium and chromium in blood in well-trained male rowers of Turkish national team during and after an aerobic maximal exercise. Eleven well-trained young male completed the exercise protocol. Blood samples were collected before the exercise, immediately after exercise, and one hour after the exercise. Blood was analyzed for Se and Cr by using inductively coupled plasma optical emission spectrometry (ICP-OES) method. Although there were no statistically differences between the pre and post Cr levels (P > 0.05), the levels observed one hour after the exercise showed statistically significant changes compared to the pre and post exercise values (P < 0.05). There was no change of statistical relevance in Se levels (P > 0.05). [ABSTRACT FROM AUTHOR]

Mercury (Hg) is likely bound to large biomolecules (e.g. proteins) in living organisms, and in order to assess Hg metabolic pathways and possible toxicological effects, it is essential to study these Hg containing biomolecules. However, the exact nature of most metal binding biomolecules is unknown. Such studies are still in their infancy and information on this topic is scarce because the analysis is challenging, mainly due to their lability upon digestion or extraction from the tissue. New analytical methods that allow complex Hg-biomolecules to be analysed intact are needed and only few very recent studies deal with this approach. Therefore, as an initial step towards the characterization of Hg containing biomolecules, an analytical procedure has been optimised using size-exclusion chromatography (SEC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. We applied this technique to elucidate the distribution and elution profile of Hg and Se, and some physiological important elements such as Fe, Ni, Zn and Cu, to assess metal binding profiles in liver and kidney samples of red deer ( Cervus elaphus ) and wild boar ( Sus scrofa ) who roam freely within the largest Hg mining district on Earth, Almadén in Spain. Elemental fractionation profiles of the extracts from different tissues were obtained using two different SEC columns (BioSep-SEC-S2000 GL 300–1 kDa and Superdex 75 10/300 GL 70–3 kDa). Similar profiles of Hg were observed in red deer and wild boar; however, significant differences were evident for liver and kidney. Moreover, the profiles of Se showed a single peak at high-medium molecular weight in all investigated tissues, while co-elution of Hg with Fe, Ni, Zn and Cu was observed. [ABSTRACT FROM AUTHOR]

Aims Selenium (Se) and zinc (Zn) are trace elements required for optimal brain functions. Thus, the role of Se and Zn against protein malnutrition induced oxidative stress on mitochondrial antioxidants and electron transport chain (ETC) enzymes from rats' brain were investigated. Main methods Normal protein (NP) and low protein (LP) rats were fed with diets containing 16% and 5% casein respectively for a period of 10 weeks. Then the rats were supplemented with Se and Zn at a concentration of 0.15 mg L − 1 and 227 mg L − 1 in drinking water for 3 weeks after which the rats were sacrificed. Key findings The results obtained from the study showed significant (p < 0.05) increase in lipid peroxidation (LPO), ROS production, oxidized glutathione (GSSG) levels and mitochondrial swelling and significant (p < 0.05) reductions in catalase (CAT) and Mn-superoxide dismutase (Mn-SOD) activities, glutathione (GSH) levels, GSH/GSSG ratio and MTT reduction as a result of LP ingestion. The activities of mitochondrial ETC enzymes were also significantly inhibited in both the cortex and cerebellum of LP-fed rats. Supplementation with either Se or Zn restored the alterations in all the parameters. Significance The study showed that Se and Zn might be beneficial in protecting mitochondrial antioxidants and ETC enzymes against protein malnutrition induced oxidative stress. [ABSTRACT FROM AUTHOR]

In this study, we investigated the protective effect of selenium (Se) on cisplatin (Cis) induced testicular damage using histopathological, immunohistochemical and biochemical approaches. Twenty-one male Wistar rats were equally divided into three groups of seven rats each: control (C), Cis, and Cis + Se. Cis and Cis + Se group rats received Cis at a dose of 12 mg/kg b.w./day, intraperitoneally for 3 consecutive days. Cis + Se group rats received selenium via oral gavage 3 mg/kg/day (twice-a day as 1.5 mg/kg) until 11th consecutive days starting at 5 days before cisplatin injection. C group received only 0.9% NaCl intraperitoneally and orally at same time and at equal volume. After the treatment, the histopathological, immunohistochemical and biochemical examinations were performed. In seminiferous tubules of Cis treated rats were observed the most consistent findings characterized with vacuolization, desquamation, disorganization, and also was a considerable reduction in elongated spermatids, however the Cis + Se group exhibited improved histopathologic changes. In the immunohistochemical examinations, caspase-3 immunopositive cells displayed higher in the Cis group according to C and Cis + Se groups. Bcl-2 and NF-κB staining revealed a moderate number in the C group and significantly fewer in the Cis group compared to the Cis + Se groups. Additionally, MDA levels were also significantly increased in the Cis group in comparison to Control group, but pretreatment with selenium prevented elevation of MDA levels significantly in Cis + Se group rats. This study indicates that Cis-treatment induced testicular apoptosis and lipid peroxidation, and combined treatment with selenium prevented severity of the toxicity in rats. [ABSTRACT FROM AUTHOR]

We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species ( n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues ( R 2 ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern ( Sterna forsteri ) and black-necked stilt ( Himantopus mexicanus ) females transferred more methylmercury to their eggs than American avocet ( Recurvirostra americana ) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver ( R 2 = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father ( R 2 = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues. [ABSTRACT FROM AUTHOR]

Selenium (Se) is shown to be an essential element for sow nutrition and a great deal of information has been accumulated for the last two decades indicating that dietary form of Se is a major determinant of its efficiency. Indeed, there are two major Se sources for pigs, namely inorganic selenium (mainly selenite or selenate) and organic selenium in the form of selenomethionine (SeMet; mainly as Se-yeast or SeMet preparations). The aim of the review is to update existing information about Se roles in sow nutrition with a specific emphasis to the oxidative stress and possibilities of decreasing negative consequences of the stresses by using dietary Se supplementation in an optimal form. It has been clearly shown that organic selenium has many important advantages in sow nutrition in comparison to traditional sodium selenite. The aforementioned benefits of organic selenium for sow include: better Se status of sows, especially in the case of advanced parities; improved antioxidant defences of sows; increased Se concentration in colostrum and milk and improved antioxidant status of colostrum and milk; improved Se transfer via placenta; improved Se status of foetus and development of pig embryos. It was proven that replacement of sodium selenite by organic Se in the sow's diet improved Se status of newly born piglets characterised by increased Se concentrations in tissues and whole body. In particular, increased Se concentration in piglet muscles could be considered as an important storage form of Se to be used in stress conditions. Furthermore, organic Se in sow's diet (versus sodium selenite) provides better Se status and antioxidant status of weaning piglets, as well as improves thyroid metabolism and increases activities of major digestive enzymes in piglet pancreas at time of weaning. However, most of the commercially relevant parameters (growth rate, mortality, FCR, etc.) were not affected. Only in two most recent publications in which sodium selenite was replaced by pure organic Se source in the sows diet, there were significant improvements in weaning litter weight and average weight of progeny piglets and daily weight gain of piglet from birth to weaning. Indeed, additional well-designed organic Se trials with big numbers of sows in commercial conditions are needed to explore a full potential of organic Se in sow nutrition. [ABSTRACT FROM AUTHOR]

Lactating mother and her two month old healthy daughter (APGAR 10) gave their scalp hair for a multielement profile analysis; 25 elements were analyzed with the ICP MS. Mother’s hair was divided into 5 cm long segment proximal to the scull ( Young ), and the distal segment further up to the hair tip ( Old ). One centimeter of hair records one month of the metabolic activity of the bioelements in the body. Mother’s Young hair and daughters hair have 2.70 and 9.74 μg g −1 Se, a distinctly higher Se concentrations than the Old hair of 0.87 μg g −1 . The adequate hair Se concentrations in Croatia women population vary from 0.08 to 0.63 μg g −1 ; values below or above that range indicate deficiency or excess, respectively. Dietary recall revealed that during the last trimester of pregnancy and over a period of a week, the mother has consumed 135 g of Brazil nuts ( Bertholletia excelsa ) (BN); BN is an exceptionally rich Se dietary source. The amount of Se in BN varies and one week consumption of 135 g of BN may result in Se daily intake of 367 to 492 μg g −1 day −1 over a period of seven consecutive days, and what is about or exceeds the Upper Limit of daily selenium intake of 400 μg −1 g −1 . The excessively high infant hair Se mirrored a natural high mother to fetus transplacental transfer of bio elements in the last trimester of pregnancy. The potential toxicological risks of such a high Se transfer remains to be elucidated. [ABSTRACT FROM AUTHOR]

Objectives Preeclampsia is a hypertensive disorder of pregnancy which is one of the leading causes of maternal and perinatal mortality and pre-term delivery, especially in low and middle income countries. Selenium is an important constituent of selenoproteins that act as antioxidant and have several metabolic functions. The present study was conducted to determine serum selenium concentration in preeclampsia patients in order to find out the role of selenium in preeclampsia. Methods This study was conducted as case-control study with 74 preeclampsia patients as cases whose gestation were ≥20 weeks (52 mild and 22 severe patients) and 118 normotensive pregnant women as controls from same gestational period. Detailed patient history was recorded during routine hospital visits. Serum selenium concentration was determined by using atomic absorption spectroscopy. Independent sample t -test and Pearson’s correlation test were done for the statistical analysis using the statistical software package SPSS, version 16. Results Our study found that mean serum concentration of selenium in preeclampsia patients was significantly lower than that of healthy pregnant women ( p < 0.05). Further analysis for selenium concentration with disease severity explored that selenium concentration was significantly lower in severe preeclampsia in comparison to mild preeclampsia ( p < 0.05). We found no significant difference for selenium concentration between rural and urban preeclampsia patients ( p > 0.05). Pearson’s correlation analysis reveals significant negative correlation of selenium with systolic blood pressure ( r = −0.419, p = 0.001), diastolic blood pressure ( r = −0.392, p = 0.001), and gestational period ( r = −0.218, p = 0.001). Conclusion Our study found that preeclampsia patients have decreased serum selenium concentration than the healthy pregnant women. [ABSTRACT FROM AUTHOR]

This study was performed to characterise selenium (Se) and Se species in cerebrospinal fluid (CSF) of sheep and its relation to the respective Se concentrations in serum. Paired samples from 10 adult sheep were used for the study. Five sheep were fed a diet with a marginal Se concentration of <0.05 mg Se/kg diet dry weight (dw, Se – ), and five animals were fed the same diet supplemented with sodium selenite revealing a concentration of 0.2 mg Se/kg diet dw (Se + ). The feeding strategy was conducted for two years; The results on metabolic effects were published previously. At the end of the feeding period, paired samples of serum and CSF were collected and analysed using ion exchange chromatography inductively coupled plasma–dynamic reaction cell–mass spectrometry (IEC-ICP-DRC-MS) technique for total Se concentration and concentrations of Se species. Albumin concentrations were analysed additionally. The feeding strategy caused significant differences ( p < 0.01) in serum Se concentrations with 33.1 ± 5.11 μg Se/l in the Se – group and 96.5 ± 18.3 μg Se/l in the Se + group, respectively. The corresponding total Se concentrations in CSF were 4.38 ± 1.02 μg Se/l and 6.13 ± 1.64 μg Se/l in the Se – and the Se + group, respectively, missing statistical significance ( p = 0.077). IEC-ICP-DRC-MS technique was able to differentiate the Se species selenoprotein P-bound Se (SePP), selenomethionine, glutathione peroxidase-bound Se (Se-GPx), selenocystine, thioredoxin reductase-bound Se, ovine serum albumin-bound Se (Se-OSA), SeIV and SeVI in ovine serum and CSF. Quantitatively, SePP is the main selenoprotein in ovine serum followed by Se-GPx. The CSF/blood ratio of albumin (Q Albumin ) reflected a physiological function of the blood-CSF barrier in all sheep. Q Se-species were higher than Q Albumin both feeding groups, supporting the hypothesis of local production of Se species in the brain. Significant positive regression lines for CSF vs. serum were found for albumin and Se-OSA only, suggesting a role of albumin to convey Se across the blood-CSF barrier. The ovine model, together with the IEC-ICP-DRC-MS technique to characterise the Se species, might be a worthwhile model for further studies as repeated sample collection as well as modification of the nutritional status is feasible and effective. [ABSTRACT FROM AUTHOR]

Selenium is a microelement of big importance for male reproduction. As a part of the antioxidative enzyme gluthationperoxidase and structural Se proteins, it plays pivotal role in the defense of spermatozoa against generated ROS and in ensuring of its motility. During the last years the interests to the organic forms of selenium was enhanced because of its better biological utilization. The present work aimed to study the effect of injective application of organic compound selenopyran in rams on the distribution of selenium content in blood and sperm and on the changes in sperm quality. The experiment was conducted with 5 rams from the Synthetic Population Bulgarian Milk breed at the age between 3-7 years and live weight 85-90 kg. The animals were injected once with an oil solution of the selenopyran in dose of 0.1mg/kg live weight (selenium content 24%) 45 days before starting the breeding season. The blood was collected before treatment and 45 days thereafter. At the same time the first and second ejaculates of rams were collected using artificial vagina and analyzed by Sperm Class Analyzer. The selenium content was measured in plasma, blood cells and sperm by atomic absorption spectrometry using SpectrAA 55B double beam spectrometer (Varian, Inc.). The results showed that one injection of organic compound of selenium - selenopyran in dose of 0.1mg/kg live weight ensured the increase and support of high level of selenium in blood (plasma and blood cells) and in sperm during investigated period. That lead to the proper spermatogenesis in testis and allowed the production of qualitative ejaculates with higher number of total spermatozoa as well as of spermatozoa with progressive motility. [ABSTRACT FROM AUTHOR]