Low Selenium Concentrations Research Articles

The APOE ε4 Allele Is Associated with Lower Selenium Levels in the Brain: Implications for Alzheimer's Disease.

The antioxidant activity of selenium, which is mainly conferred by its incorporation into dedicated selenoproteins, has been suggested as a possible neuroprotective approach for mitigating neuronal loss in Alzheimer's disease. However, there is inconsistent information with respect to selenium levels in the Alzheimer's disease brain. We examined the concentration and cellular compartmentalization of selenium in the temporal cortex of Alzheimer's disease and control brain tissue. We found that Alzheimer's disease was associated with decreased selenium concentration in both soluble (i.e., cytosolic) and insoluble (i.e., plaques and tangles) fractions of brain homogenates. The presence of the APOE ε4 allele correlated with lower total selenium levels in the temporal cortex and a higher concentration of soluble selenium. Additionally, we found that age significantly contributed to lower selenium concentrations in the peripheral membrane-bound and vesicular fractions. Our findings suggest a relevant interaction between APOE ε4 and selenium delivery into brain, and show changes in cellular selenium distribution in the Alzheimer's disease brain.

SELENIUM STATUS OF PRESCHOOL CHILDREN IN YAROSLAVL REGION

The article presents the assessment results of the selenium status of children living in Yaroslavl city which is situated in a selenium deficient area of the European part of Russia. Hair samples of 201 preschool children (1-6 year-old ) were collected in 2011-2015. Bio-substrate analysis has revealed that median of the essential selenium content in the hair of 1-3 year-old children was 0,67 |jg/g, of 4-6-year-old children - 0,78 |jg/g, which was at the lower edge of the centile intervals for the central part of Russia. 46 % of the surveyed children had low hair selenium content. Additionally, in order to study the role of drinking water in supply of children's body with selenium, concentration of this micro-element in drinking water of the examined preschools was determined. Besides, average daily dose of selenium ingestion with drinking water has been calculated. As a result, it was stated that selenium ingestion with drinking water in preschool children's organism in Yaroslavl was lower than 1% of the essential daily demand.

Serum Selenium Level in Patients with Chronic Liver Disease

Background: Selenium has been shown to protect against liver necrosis. Selenium deficiency has been involved in the pathogenesis of chronic hepatitis B and C related hepatocellular damage.Serum selenium concentration in cirrhotics was found tobe low, supportive selenium administration may be beneficial for them.Reduced selenium levels result in accumulation of lipid peroxides which accelerate the growth of hepatocellular carcinoma (HCC). Aim: To study serum selenium level in patients with chronic liver diseases and its relation with severity of theliver diseases. Patients and Methods: This case–control study was conducted on 100 subjects. The cases were 80 adult patients including chronic hepatitis C and B, liver cirrhosis and HCC.The study also included 20 healthy age and sex-matched subjects served as a control group. Clinical, laboratory and radiological data and blood samples were collected from all participants. Serum selenium concentration was measured and statistical analysis was done. Results: Selenium concentration was significantly lower in patients compared to healthy controls.Selenium levelwas found low in Chronic HBV, chronic HCV patients and lower incirrhotic group and the lowest in HCC group. Patients with advanced liver cirrhosis (Child B, C) had significantly lower selenium level compared to those with Child A. Conclusion: Selenium was lower in patients with chronic liver disease and its leveldecreases with the progression of liver disease. Patients with HCC had the lowest Selenium concentration that might correlate with the pathophysiology of HCC. Chronic hepatitis C and B, liver cirrhosis and HCC were independent predictors forSelenium deficiency.

Low serum selenium concentrations in French patients with measles

ObjectiveSelenium deficiency adversely affects the clinical outcome of measles in the tropics. In developed countries, serum selenium level has never been investigated during acute measles. The aim of this study was to determine serum selenium concentrations in French patients with acute measles and to seek correlations with clinical and virological findings. Patients and methodsWe studied serum selenium concentrations in 94 French patients with acute measles and in 99 healthy controls matched for age and sex. ResultsThe mean of selenium concentration was significantly lower in the patients than in the controls (46.4±14.1μg/L versus 86.5±13.9μg/L, P<0.0001). In the patients, selenium concentrations were not associated with age, sex, vaccination status, clinical signs or specific antibody responses. Selenium levels did not differ significantly between patients with uncomplicated measles (45.8±14.2μg/L) and patients with complications (52.7±13.2μg/L) (P=0.15). ConclusionAcute measles is associated with significant reduction of selenium level that did not seem to negatively affect the course of the disease suggesting compensating mechanisms in patients from developed countries against the disease.

PP.19.18] SELENIUM AND HYPERTENSION

Objective: Until now, there was a widespread belief in the scientific community that correcting a selenium deficit in marginally supplied individuals provides health benefits. The vast majority of published analyses in this respect report a positive correlation or no interaction. For example, Nawrot et al. in 2007 concluded that relative selenium deficit might constitute an underestimated risk factor for the development of high blood pressure, especially in European men, and Lubos et al. reasoned in 2010 that low selenium concentrations were associated with risk of future cardiovascular death in patients with acute coronary syndrome. There ist increasing interest in using selenium for prevention of cancer or other serious diseases or for treatment of prevention of side effects from an effective oncological therapy. Design and method: Our own prospective randomized trial studied the use of a selenium supplement in selenium deficient female cancer patients receiving pelvic irradiation for gynecological tumors. It was possible to improve and balance the pre-existing selenium deficiency by supplementing 500 ug sodium selenite per day orally during the five to six weeks of radiotherapy. Results: The supplementation reduced the number of episodes and severity of radiation-associated diarrhoe. With regard to possible hypertensinogenic effects of selenium, hypertension or other cardiovscular events were not observed; instead, selenium efficiently reduced some side effects of the radiation treatment. In the long-term follow-up of more than five years, we observed even a small but statistically significant advantage of overall survival in the patient group reveiving seleniujm supplementation without any detectable cardiovascular disadvantage. Conclusions: These findings are of clinical importance as cardiovascular events belong to the main causes of mortalities in tumor patients, apart from the cancer mortality itself.

Serum Concentration of Zinc, Copper, Selenium, Manganese, and Cu/Zn Ratio in Children and Adolescents with Myopia

The purpose of the present study was the assessment of the serum concentration of antioxidant microelements-zinc, copper, selenium, manganese, and Cu/Zn ratio in children and adolescents with myopia. Eighty-three children were examined (mean age 14.36±2.49years) with myopia. The control group was 38 persons (mean age 12.89±3.84years). Each patient had complete eye examination. The serum concentration of zinc, copper, manganese, and selenium was determined by atomic absorption spectrometry. Cu/Zn ratio, which is the indicator of the oxidative stress, was also calculated. The average serum concentration of zinc in myopic patients was significantly lower (0.865±0.221mgL-1) in comparison to the control group (1.054±0.174mgL-1). There was significantly higher Cu/Zn ratio in myopic patients (1.196±0.452) in comparison to that in the control group (0.992±0.203). The average serum concentration of selenium in the study group was significantly lower (40.23±12.07μgL-1) compared with that in the control group (46.00±12.25μgL-1). There were no essential differences between serum concentration of copper and manganese in the study group and the control group. Low serum concentration of zinc and selenium in myopic children may imply an association between insufficiency of these antioxidant microelements and the development of the myopia and could be the indication for zinc and selenium supplementation in the prevention of myopia. Significantly, higher Cu/Zn ratio in the study group can suggest the relationship between myopia and oxidative stress.

Supplementation with Selenium and Coenzyme Q10 Reduces Cardiovascular Mortality in Elderly with Low Selenium Status. A Secondary Analysis of a Randomised Clinical Trial.

BackgroundSelenium is needed by all living cells in order to ensure the optimal function of several enzyme systems. However, the selenium content in the soil in Europe is generally low. Previous reports indicate that a dietary supplement of selenium could reduce cardiovascular disease but mainly in populations in low selenium areas. The objective of this secondary analysis of a previous randomised double-blind placebo-controlled trial from our group was to determine whether the effects on cardiovascular mortality of supplementation with a fixed dose of selenium and coenzyme Q10 combined during a four-year intervention were dependent on the basal level of selenium.MethodsIn 668 healthy elderly individuals from a municipality in Sweden, serum selenium concentration was measured. Of these, 219 individuals received daily supplementation with selenium (200 μg Se as selenized yeast) and coenzyme Q10 (200 mg) combined for four years. The remaining participants (n = 449) received either placebo (n = 222) or no treatment (n = 227). All cardiovascular mortality was registered. No participant was lost during a median follow-up of 5.2 years. Based on death certificates and autopsy results, all mortality was registered.FindingsThe mean serum selenium concentration among participants at baseline was low, 67.1 μg/L. Based on the distribution of selenium concentration at baseline, the supplemented group was divided into three groups; <65 μg/L, 65–85 μg/L, and >85 μg/L (45 and 90 percentiles) and the remaining participants were distributed accordingly. Among the non-treated participants, lower cardiovascular mortality was found in the high selenium group as compared with the low selenium group (13.0% vs. 24.1%; P = 0.04). In the group with the lowest selenium basal concentration, those receiving placebo or no supplementation had a mortality of 24.1%, while mortality was 12.1% in the group receiving the active substance, which was an absolute risk reduction of 12%. In the middle selenium concentration group a mortality of 14.0% in the non-treated group, and 6.0% in the actively treated group could be demonstrated; thus, there was an absolute risk reduction of 8.0%. In the group with a serum concentration of >85 μg/L, a cardiovascular mortality of 17.5% in the non-treated group, and 13.0% in the actively treated group was observed. No significant risk reduction by supplementation could thus be found in this group.ConclusionsIn this evaluation of healthy elderly Swedish municipality members, two important results could be reported. Firstly, a low mean serum selenium concentration, 67 μg/L, was found among the participants, and the cardiovascular mortality was higher in the subgroup with the lower selenium concentrations <65 μg/L in comparison with those having a selenium concentration >85 μg/L. Secondly, supplementation was cardio-protective in those with a low selenium concentration, ≤85 at inclusion. In those with serum selenium>85 μg/L and no apparent deficiency, there was no effect of supplementation. This is a small study, but it presents interesting data, and more research on the impact of lower selenium intake than recommended is therefore warranted.Trial RegistrationClinicaltrials.gov NCT01443780

73 Comparison of serum selenium levels among hypertensive and normotensive pregnant women from southern brazil: A Case control-study

Introduction The hypertensive disorders of pregnancy (HDP) are the leading cause of maternal death in the world; however, its pathogenesis is not fully understood. It is believed that a dysfunction in the placentation process leads to oxidative stress, thus antioxidants like selenium could be a protective factor Objectives To correlate serum selenium levels with HDP in our population, considering a possible protective factor of this mineral. Methods This case-control study included 32 normotensive pregnant women, 20 with hypertension (chronic and gestational hypertension) and 38 patients with preeclampsia. All patients were derived from antenatal or obstetric admission of a tertiary hospital Southern Brazil. Serum selenium was measured at the time of inclusion in the study. Patients were followed until hospital discharge after delivery. The significance level was 5% (p ⩽ 0.05) and analyzes were performed using SPSS version 18. Values were expressed as mean ± standard deviation. Chi-square test was utilized for the categorical variables. Continuous variables were first tested using the Shapiro–Wilk test and then applied an independent-sample t test, Mann–Whitney U test, one-way analysis of variance (with post hoc Student–Newman–Keul) or Kruskal–Wallis test according with the groups. Results The patients did not differ with regard to maternal age, ethnicity, years of education, parity, and smoking prevalence. Normotensive patients had lower body mass index and were included in the study earlier. In addition, these patients had a higher prevalence of other comorbidities excluding hypertension. Patients with preeclampsia had higher levels of systolic blood pressure on admission. Continuous use of medication and HDP history in previous pregnancies were more common in patients with preeclampsia. 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 group with preeclampsia (P = 0.67). Of patients with preeclampsia, 52.6% had severe preeclampsia. Serum selenium levels of these patients did not differ significantly from the control group (P = 0.77). Preeclampsia was associated with earlier interruption of pregnancy and lower birth weight (P Conclusions There was no significant difference in the concentration of serum selenium between normotensive and hypertensive women, thus not being possible to establish selenium as a protective factor. Besides, we found that our population is extremely selenium deficient. One may speculate that population-wide low plasma concentrations of selenium may be one etiology accounting for the higher incidence of preeclampsia and may conjecture that selenium supplementation might lower this incidence.

Blood Trace Element Concentrations in Polycystic Ovary Syndrome: Systematic Review and Meta-analysis.

Polycystic ovary syndrome (PCOS) is a prevalent condition in women of reproductive age. PCOS is characterized by androgen excess and chronic anovulation and associated with low-grade inflammation and metabolic comorbidities. Some trace elements have been linked to pathophysiological mechanisms of oxidative stress and inflammation in different disorders. Therefore, we conducted a systematic review and meta-analysis of the available evidence regarding trace element concentrations in PCOS. We reviewed MEDLINE and EMBASE in search of case-control, cross-sectional, and cohort studies published until September 2015. Of 183 studies identified, six were selected for systematic review. All used the Rotterdam criteria for the diagnosis of PCOS. Two studies evaluating chromium and one assessing cobalt levels did not observe differences between PCOS and controls. Another study recorded similar nickel and vanadium levels between the groups, but lower selenium concentrations in women with PCOS compared to controls. Four studies were included in the random effects model meta-analysis, for a total of 264 PCOS and 151 control women. Copper levels were found to be higher in women with PCOS than in controls [mean difference 0.12ppm (95% CI 0.07; 0.17ppm); I 2 = 0%]. Manganese [mean difference 0.04ppm (95% CI -0.05; 0.13ppm); I 2 = 94.4%] and zinc concentrations [mean difference 0.02ppm (95% CI -0.12; 0.16ppm); I 2 = 92.4%] were similar between the groups. The present results suggest a relationship between increased copper concentration and PCOS. This systematic review and meta-analysis is registered in PROSPERO under number CRD42016034036.

Blood Selenium Concentration and Blood Cystatin C Concentration in a Randomly Selected Population of Healthy Children Environmentally Exposed to Lead and Cadmium.

This study aimed at evaluation of a relationship between blood selenium concentration (Se-B) and blood cystatin C concentration (CST) in a randomly selected population of healthy children, environmentally exposed to lead and cadmium. The studies were conducted on 172 randomly selected children (7.98±0.97years). Among participants, the subgroups were distinguished, manifesting marginally low blood selenium concentration (Se-B 40-59μg/l), suboptimal blood selenium concentration (Se-B: 60-79μg/l) or optimal blood selenium concentration (Se-B≥80μg/l). At the subsequent stage, analogous subgroups of participants were selected separately in groups of children with BMI below median value (BMI <16.48kg/m2) and in children with BMI≥median value (BMI ≥16.48kg/m2). In all participants, values of Se-B and CST were estimated. In the entire group of examined children no significant differences in mean CST values were detected between groups distinguished on the base of normative Se-B values. Among children with BMI below 16.48kg/m2, children with marginally low Se-B manifested significantly higher mean CST values, as compared to children with optimum Se-B (0.95±0.07 vs. 0.82±0.15mg/l, p<0.05). In summary, in a randomly selected population of healthy children no relationships could be detected between blood selenium concentration and blood cystatin C concentration. On the other hand, in children with low body mass index, a negative non-linear relationship was present between blood selenium concentration and blood cystatin C concentration.

Exotic pediculosis and hair-loss syndrome in deer (Odocoileus hemionus) populations in California.

Infestation with nonnative, "exotic" lice was first noted in Washington black-tailed deer (Odocoileus hemionus columbianus) in 1994 and has since then spread throughout the western United States. In California, infestation with the exotic louse Damalinia (Cervicola) sp. was first detected in black-tailed deer from northern California in 2004, and, in 2009, the exotic louse species Bovicola tibialis and Linognathus africanus were identified on mule deer (Odocoileus hemionus californicus) in central Sierra Nevada in association with a mortality event. Exotic lice have since been detected in various locations throughout the state. We describe the geographic distribution of these exotic lice within California, using data from 520 live-captured and 9 postmortem-sampled, free-ranging mule deer examined between 2009 and 2014. Data from live-captured deer were used to assess possible associations between louse infestation and host age, host sex, migratory behavior, season, and blood selenium and serum copper concentrations. Damalinia (Cervicola) sp. and B. tibialis lice were distinctively distributed geographically, with D. (Cervicola) sp. infesting herds in northern and central coastal California, B. tibialis occurring in the central coastal mountains and the Sierra Nevada, and L. africanus occurring only sporadically. Younger age classes and low selenium concentrations were significantly associated with exotic louse infestation, whereas no significant relationship was detected with serum copper levels. Our results show that exotic lice are widespread in California, and younger age classes with low blood selenium concentrations are more likely to be infested with lice than older deer.

Biofortification of Carrot (Daucus carota L.) with Iodine and Selenium in a Field Experiment.

The low content of iodine (I) and selenium (Se) forms available to plants in soil is one of the main causes of their insufficient transfer in the soil-plant-consumer system. Their deficiency occurs in food in the majority of human and farm animal populations around the world. Both elements are classified as beneficial elements. However, plant response to simultaneous fertilization with I and Se has not been investigated in depth. The study (conducted in 2012–2014) included soil fertilization of carrot cv. “Kazan F1” in the following combinations: (1) Control; (2) KI; (3) KIO3; (4) Na2SeO4; (5) Na2SeO3; (6) KI+Na2SeO4; (7) KIO3+Na2SeO4; (8) KI+Na2SeO3; (9) KIO3+Na2SeO3. I and Se were applied twice: before sowing and as top-dressing in a total dose of 5 kg I⋅ha-1 and 1 kg Se⋅ha-1. No negative effects of I and Se fertilization were noted with respect to carrot yield. Higher accumulation and the uptake by leaves and storage roots of I and Se were obtained after the application of KI than KIO3, as well as of Na2SeO4 than Na2SeO3, respectively. Transfer factor values for leaves and roots were about a dozen times higher for Se than for I. Selenomethionine content in carrot was higher after fertilization with Na2SeO4 than with Na2SeO3. However, it was the application of Na2SeO3, KI+Na2SeO3 and KIO3+Na2SeO3 that resulted in greater evenness within the years and a higher share of Se from selenomethionine in total Se in carrot plants. Consumption of 100 g f.w. of carrots fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 can supply approximately or slightly exceed 100% of the Recommended Daily Allowance for I and Se. Moreover, the molar ratio of I and Se content in carrot fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 was the best among the research plots.

Long-term trends in the metabolic profile test results in German Holstein dairy herds in Thuringia, Germany

Systematic metabolic profile tests at regular intervals provide important information to meet the increasing challenges in managing dairy herds. This study aimed at deriving long-term trends from the results of metabolic profile tests in Thuringian German Holstein dairy herds. Blood and urine samples were collected from 710 fresh, high yielding, and dry cows, respectively, to monitor 13 parameters including the serum non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), bilirubin, β-carotene and urea concentrations, the serum of aspartate aminotransferase and glutamate dehydrogenase activities, the serum concentrations of the minerals calcium, inorganic phosphate and selenium, the urine potassium and sodium concentrations, and the net acid-base excretion (NABE). A total of 17,070 group samples from 103 herds were collected during 1997-2014. Period prevalence of aberrant groups was calculated for each parameter and year accordingly. Using a linear regression model, a long-term trend of the period prevalence was determined. To account for the 15 aberrancies possible for each stage of lactation, seven significant trends were found for dry, nine for fresh, and ten for lactating cows. A decrease of the period prevalence was detected for increased NEFA, for low serum β-carotene, selenium, inorganic phosphate, and urea concentrations, for low sodium and high potassium urine concentrations, and for increased NABE. In contrast, period prevalence increased significantly for cases with increased serum aspartate aminotransferase and glutamate dehydrogenase activities, increased bilirubin concentration, and low NABE. Metabolic profile tests enable a description of the herd health status using objectively measured data as a basis for the implementation of measures to optimize herd management to improve the herd health status.

Imbalance in Protein Thiol Redox Regulation and Cancer-Preventive Efficacy of Selenium.

Although several experimental studies showed cancer-preventive efficacy of supplemental dietary selenium, human clinical trials questioned this efficacy. Identifying its molecular targets and mechanism is important in understanding this discrepancy. Methylselenol, the active metabolite of selenium, reacts with lipid hydroperoxides bound to protein kinase C (PKC) and is oxidized to methylseleninic acid (MSA). This locally generated MSA selectively inactivates PKC by oxidizing its critical cysteine sulfhydryls. The peroxidatic redox cycle occurring in this process may explain how extremely low concentrations of selenium catalytically modify specific membrane-bound proteins compartmentally separated from glutathione and selectively induce cytotoxicity in promoting cells. Mammalian thioredoxin reductase (TR) is itself a selenoenzyme with a catalytic selenocysteine residue. Together with thioredoxin (Trx), it catalyzes reduction of selenite and selenocystine by NADPH generating selenide which in the presence of oxygen redox cycles producing reactive oxygen species. Trx binds with high affinity to PKC and reverses PKC inactivation. Therefore, established tumor cells overexpressing TR and Trx may escape the cancer-preventive actions of selenium. This suggests that in some cases, certain selenoproteins may counteract selenometabolite actions. Lower concentrations of selenium readily inactivate antiapoptotic PKC isoenzymes e and a which have a cluster of vicinal thiols, thereby inducing apoptosis. Higher concentrations of selenium also inactivate proapoptotic enzymes such as proteolytically activated PKCd fragment, holo-PKCz, caspase-3, and c-Jun N-terminal kinase, which all have a limited number of critical cysteine residues and make tumor cells resistant to selenium-induced apoptosis. This may explain the intriguing U-shaped curve that is seen with dietary selenium intake and the extent of cancer prevention.

Selenite is More Efficient than Selenate in Alleviation of Salt Stress in Lettuce Plants

Abstract There is increasing evidence showing that low selenium (Se) concentrations may increase tolerance of crop plants to several environmental stresses. The aim of this study was to compare the influence of two chemical forms of Se (selenite or selenate) at different concentrations (2 or 6 μM) on the resistance of butterhead lettuce (Lactuca sativa L. var. capitata) cv. Justyna to NaCl-induced stress (40 mM NaCl). Plant growth was negatively affected by salinity, but the level of photosynthetic pigments was not reduced. Se application at a concentration of 2 μM significantly improved the growth of salt-stressed plants, but selenite was much more effective than selenate in enhancing salt-tolerance of lettuce. The growth-promoting effect of Se was also noted at 6 μM of selenite, but did not appear at 6 μM of selenate. The beneficial effect of Se in salt-stressed lettuce could be due to antioxidative activity of Se, root system growth stimulation, and/or increase in photosynthetic pigment concentration after Se supplementation; however, it was not related to either increase in proline accumulation or reduction in foliar Na+ or Cl− concentration. These results imply that Se application, especially in the form of selenite, can enhance antioxidant defense of lettuce under salt stress, and Se supplementation may be recommended for areas of lettuce cultivation with excessive salt accumulation.

Selenium deficiency induced damages and altered expressions of metalloproteinases and their inhibitors (MMP1/3, TIMP1/3) in the kidneys of growing rats

Selenium is an essential trace element for the maintenance of structures and functions of kidney. To evaluate the effects of low selenium on the kidneys of growing rats, newborn rats were fed with selenium deficient and normal diets respectively for 109 days. As a result, rats fed with low selenium diets resulted in a decline in the body weight and the concentration of selenium in the kidney, especially the male rats from the low selenium groups. Moreover, the ultrastructure of glomerulus and tubules were damaged in low selenium group: the glomeruli were observed with hyperplasia of mesangial cells, fusion of podocyte foot processes and thickening of basement membrane; and the tubules were observed with vacuolar degenerated epithelial cells, increased edema fluid or protein solution between cells, microvilli edema, increased cell gaps and decreased cell links. Furthermore, the pathological changes in selenium deficient group included the increase of fibers around renal hilum aorta and in the renal collecting duct, and shed of cells in the proximal convoluted tubules. In addition, up-regulated expressions of matrix metalloproteinases (MMP1/3) and down-regulated expressions of their inhibitors (TIMP1/3) at the mRNA and protein levels were also appeared to be relevant to low selenium. The results suggested that low selenium in diet may cause low selenium concentration in the kidney of growing rat and lead to damages of the ultrastructure and extracellular matrix (ECM) of kidney.

Impact of fetal and childhood mercury exposure on immune status in children

BackgroundMercury exposure have been shown to affect immune status in animals as reflected by cytokine expression. It is unclear whether low levels of exposure during fetal and/or childhood periods could impact on immune status in humans. ObjectivesTo test the hypothesis that fetal and childhood mercury exposure is associated with childhood cytokine profiles and to investigate whether childhood selenium levels interact with any of the associations found. MethodsChildren were recruited from a previously established birth cohort between the ages of 6–9 years for assessment and measurement of blood mercury, selenium and cytokine profile (interleukin (IL)-4, IL-6, IL-8, IL-10, IL-13 and TNF-alpha). Multivariable linear regression models were used to assess the adjusted association of cord blood mercury concentration and current mercury concentrations with levels of the cytokine levels. We tested whether the association with current mercury level varied by current selenium level and cord blood mercury level. ResultsIL-10 was negatively associated with current blood mercury concentration. The effect was greatest in cases with low cord blood mercury and low current selenium concentrations. None of the other cytokine levels were associated with either cord blood or current blood mercury concentrations, except that cord blood mercury was negatively associated with IL-6. ConclusionsChildhood mercury exposure was negatively associated with childhood IL-10 levels. It is postulated that while selenium is protective, low levels of fetal mercury exposure may increase the degree of this negative association during childhood. Further studies into the clinical significance of these findings are required.

Scientific Opinion on the safety and efficacy of selenium compounds (E8) as feed additives for all animal species: sodium selenite (coated granulated preparation), based on a dossier submitted by Doxal Italia S.p.A

Selenium is a trace element that is essential for vertebrates and involved in a series of vital metabolic functions. The additive, a coated granulated preparation of sodium selenite, consists of carrier granules to which the active compound, sodium selenite, is fixed using filming agents; it is manufactured with different selenium contents. Sodium selenite is considered to be a safe source of selenium for all animal species/categories, also when applied in coated granulated preparations. Based on extensive published literature data, the use of sodium selenite as a source of selenium in animal nutrition is considered to be safe for the consumer, provided that the total maximum authorised content of selenium in complete feed is respected. No concerns would arise from inhalation of selenium during the handling of the coated granulated preparation of sodium selenite owing to the very low estimated exposure. The coated granulated preparation of sodium selenite is considered to be an irritant to the skin, eyes and the respiratory system, and a skin sensitizer. Systemic exposure to selenium could result from dermal contact, particularly when cutaneous absorption of sodium selenite might be facilitated by skin damage; any dermal contact with the additive should be avoided. The use of sodium selenite in animal nutrition up to the maximum authorised content in feed would not raise concerns regarding the soil compartment, the ground or surface water. Concerning the marine sediments, given standard aquaculture practices and the low potential maximum concentration of selenium from fish feeds, any impact on the environment is unlikely. The coated granulated preparation of sodium selenite is an efficacious source of the essential trace element selenium for all animal species.

Low serum selenium concentration is associated with preeclampsia in pregnant women from Bangladesh

ObjectivesPreeclampsia 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. MethodsThis 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. ResultsOur 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). ConclusionOur study found that preeclampsia patients have decreased serum selenium concentration than the healthy pregnant women.

Selenium content in European smelt (Osmerus eperlanus eperlanus L.) in Pomerania Bay, Gdansk Bay and Curonian Lagoon

Migratory smelt (Osmerus eperlanus eperlanus L.) may be perceived as a valuable indicative organism in monitoring the current environmental status and in assessment of a potential risk caused by selenium pollution. The aim of the study was to compare the selenium content in the European smelt from the Bay of Pomerania, Gdansk, and the Curonian Lagoon. The experimental material consisted of smelt samples (muscle) caught in the bays of Gdansk and Pomerania and the Curonian Lagoon (estuaries of the three largest rivers in the Baltic Sea basin: the Oder, the Vistula and the Neman). A total of 133 smelt were examined (Pomerania Bay n = 67; Gdansk Bay n = 35; Curonian Lagoon n = 31). Selenium concentrations were determined spectrofluorometrically. The data were analyzed statistically using one-way analysis of variance, calculated in Statistica PL software. The region of fish collection significantly affected the content of selenium in the examined smelts. The highest content of selenium was observed in smelt caught in the Bay of Gdansk (0.236 µg g -1 w.w.), then in smelt from the Pomeranian Bay (0.165 µg g-1 w.w.), and the lowest in smelt obtained in the Curonian Lagoon (Lithuania) (0.104 µg g-1 w.w.). The low concentrations of selenium recorded in the smelt show that there is a deficiency of this element, especially in the Curonian Lagoon (Lithuania). Geochemically, Poland and Lithuania are selenium deficient areas. Migratory smelt may serve as indicative organisms of environmental levels of selenium.