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PubMed2002

[Selenium plasma concentrations in children with celiac disease in different stages of diagnosis].

Selenium is an important nutritional factor of human diet. Epidemiological and experimental data indicate that low selenium level can be associated with increased risk of cancer. On the other hand there are some evidence that patients with celiac disease can present selenium deficiency and increased risk of certain malignancies. Therefore the aim of study was to evaluate plasma selenium levels in children with celiac disease. The level of selenium was estimated by flame atomic absorptiometry method according to Whiteside. Celiac disease was diagnosed according to ESPGHAN criteria. Obtained results indicate that in celiac disease low plasma selenium levels are especially marked at preliminary stage of diagnosis and following low compliance to the gluten free diet. Children with this sickness may need supplementation of their diet with selenium.

Adolescent↗
PubMed2002

Selenium modulation of cell proliferation and cell cycle biomarkers in human prostate carcinoma cell lines.

Prostate cancer (PCA) is the most common histological malignancy and the second leading cause of cancer deaths among North American men. There has been considerable interest in the chemopreventative properties of selenium. In this study, we assessed whether selenium inhibits cell growth and associated cell cycle regulatory proteins. Human PCA cells (LNCaP, PC3, PC3-AR2, and PC3-M) were incubated with and without selenium (Seleno-DL-methionine, 150 microM) for 24, 48, and 72 h. Cells were fixed and stained with propidium iodide for flow cytometry analysis. In parallel experiments, total protein was extracted, immunoprecipitated with cyclin E antibody, and analyzed by Western blot for the expression of cell cycle markers. Treatment with selenium caused G1 arrest and an 80% reduction in the S phase of LNCaP with no effect on PC3. However, PC3 cells transfected with the androgen receptor (PC3-AR2) exhibited a G2/M arrest and a marked reduction (57%) in the S phase during cell cycle progression. In the analysis of cell cycle regulatory molecules, selenium-treated cells demonstrated a significant induction of cyclin-dependent kinase inhibitors Cip1/p21 and Kip1/p27. These data suggest that selenium possesses strong antiproliferative properties in regard to human PCA. This effect appears to be dependent on the presence of a functioning androgen receptor. This provides a theoretical basis for Phase III studies of selenium in PCA prevention.

Biomarkers, Tumor↗
PubMed2002

Baseline characteristics and the effect of selenium supplementation on cancer incidence in a randomized clinical trial: a summary report of the Nutritional Prevention of Cancer Trial.

The Nutritional Prevention of Cancer Trial was a randomized, clinical trial designed to evaluate the efficacy of selenium as selenized yeast (200 microg daily) in preventing the recurrence of nonmelanoma skin cancer among 1312 residents of the Eastern United States. Original secondary analyses through December 31, 1993 showed striking inverse associations between treatment and the incidence of total [hazard ratio (HR) = 0.61, 95% confidence interval (CI) = 0.46-0.82], lung, prostate, and colorectal cancer and total cancer mortality. This report presents results through February 1, 1996, the end of blinded treatment. Effect modification by baseline characteristics is also evaluated. The effects of treatment overall and within subgroups of baseline age, gender, smoking status, and plasma selenium were examined using incidence rate ratios and Cox proportional hazards models. Selenium supplementation reduced total (HR = 0.75, 95% CI = 0.58-0.97) and prostate (HR = 0.48, 95% CI = 0.28-0.80) cancer incidence but was not significantly associated with lung (HR = 0.74, 95% CI = 0.44-1.24) and colorectal (HR = 0.46, 95% CI = 0.21-1.02) cancer incidence. The effects of treatment on other site-specific cancers are also described. The protective effect of selenium was confined to males (HR = 0.67, 95% CI = 0.50-0.89) and was most pronounced in former smokers. Participants with baseline plasma selenium concentrations in the lowest two tertiles (<121.6 ng/ml) experienced reductions in total cancer incidence, whereas those in the highest tertile showed an elevated incidence (HR = 1.20, 95% CI = 0.77-1.86). The Nutritional Prevention of Cancer trial continues to show a protective effect of selenium on cancer incidence, although not all site-specific cancers exhibited a reduction in incidence. This treatment effect was restricted to males and to those with lower baseline plasma selenium concentrations.

Age Distribution↗
PubMed2002

Soil and wheat grain selenium content in the vicinity of Koprivnica (Croatia).

This paper describes the findings of selenium measurement in three types of soil (semigley, pseudogley and hypogley) and in wheat grain cultivated in these types of soil in the vicinity of Koprivnica using hydrid atomic absorption spectrometry. The results showed relatively low selenium levels in all three types of soil (145-333 micrograms Se/kg dry weight) as well as the wheat grain (22-62 micrograms Se/kg dry weight). The analysis of covariance suggested that the concentration of selenium in soil, pH in KCl, and K2O affect the concentration of selenium in wheat grain. After the analysis was repeated using only selenium in soil, pH in KCl, and K2O as covariates, the selenium content in wheat grain was found to vary significantly with the type of soil. Although this study was performed in a small area in relation to the area of the country, it may be a good starting point for further investigation of selenium in Croatia.

Croatia↗
PubMedDate not supplied

The kinetic study of the selenium yeast stability.

The kinetics of degradation of selenium yeast was investigated at different temperatures. The effect of temperature has been determined and from this data, applying of Arrhenius-law, the stability of selenium yeast at 25 degrees C has been predicted and the t10 was determined. The changes in selenium content of the selenium yeast were determined by the fluorimetric method. It was proved, that the decomposition observed the first-order kinetic equations. The shelf life of selenium yeast predicted from the Arrhenius plot exceeded 1126 days. In the other hand the stability of selenium preparation in normal storage conditions (T = 25 degrees C) was determined to compare with predicted values. These results were found in agreement with experimental ones obtained at room temperature. No discernible physical changes of selenium preparations were observed after the storage in normal conditions (25 degrees C).

Fluorometry↗
PubMed2002

[Determination of arsenic and selenium in the industrial sulphur].

In this paper, the method of determining arsenic and selenium in the industrial sulphur sample has been studied. Carbon tetrachloride-boromine was used to dissolve the sulphur sample in classical methods, which is complex and harmful, and a little arsenic and selenium will be lost. In this paper, nitric acid and perchloric acid were used to dissolve the sulphur sample, which was simple, and scarcely arsenic and selenium were lost. Under the selected conditions, determination of arsenic and selenium can be determined simultaneously by HG-ICP-AES. The determination limits of arsenic and selenium are 0.6 ng.mL-1 and 0.7 ng.mL-1, respectively, the relatively standard deviations(RSD) (n = 8) are 2.1% for arsenic and 1.9% for selenium, respectively, and the recoveries are 99.6% for arsenic and 101% for selenium, respectively, which was a very satisfying result.

Arsenic↗
PubMed2003

Toenail selenium levels and the subsequent risk of prostate cancer: a prospective cohort study.

Results of a randomized controlled trial have suggested a protective effect of selenium against prostate cancer. Few other prospective studies have been conducted to confirm or refute this. The association between prostate cancer and baseline toenail selenium level was evaluated in the Netherlands Cohort Study, conducted among 58,279 men, aged 55-69 years at entry. In September 1986, the cohort members completed a questionnaire on risk factors for cancer and provided toenail clippings for determination of baseline selenium status. After 6.3 years of follow-up, 540 incident prostate carcinoma cases and 1,211 subcohort members with complete toenail selenium data were available for case-cohort analyses. In multivariate survival analysis, an inverse association between toenail selenium level and prostate cancer risk was observed. Incidence rate ratios in increasing selenium quintiles were 1.00 (ref), 1.05, 0.69, 0.75, and 0.69 (95% confidence interval, 0.48-0.99), respectively (P-trend=0.008). This association persisted after exclusion of cases diagnosed during early follow-up. The inverse association was more pronounced in ex-smokers than current smokers, and unclear in never-smokers. Analysis of effect modification by intake of antioxidant vitamins C, E, and the carotenoids alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin showed a strong, significant interaction with beta-cryptoxanthin, and to a lesser extent with vitamin C. These results confirm the hypothesis that higher selenium intake may reduce prostate cancer risk. Future research on optimum dose level is needed.

Aged↗
PubMed1992

Response to selenium supplementation of sheep grazing cultivated pastures in the Natal Midlands.

The response to selenium supplementation of sheep grazing cultivated pastures was investigated on different farms in the Natal Midlands, Republic of South Africa. Over a period of one year, a significant (P < 0.01) improvement of 18.2% in live mass gain and of 13.7 and 15.8% (P < 0.05) in greasy and clean wool production, respectively, was measured in response to selenium supplementation in young ewes at the Cedara Research Station. In ewes injected with a long-acting barium selenate product, the glutathione peroxidase (GSH-Px) activity in the erythrocytes was maintained at elevated levels, above that of the control group, for almost 2 years. On 6 private farms, mature ewes were dosed approximately 6 weeks before mating, with a long-acting intraruminal selenium pellet. On 2 of the farms, a significant improvement (P < 0.05) in fertility of ewes was observed with no response to supplementation in the birth mass, lamb growth rate, or in lamb mortality. The long-acting pellets maintained elevated erythrocyte GSH-Px activity in the ewes for approximately one year. Although sheep on some farms in the Natal Midlands responded to selenium supplementation, it seems advisable to establish the selenium status of a flock before embarking on a supplementation programme. The risk of an excessive selenium intake, through the inadvertent supplying of selenium in different feed sources, has been demonstrated and should be guarded against.

Animal Feed↗
PubMed1992

An assessment of the selenium, copper and zinc status of sheep on cultivated pastures in the Natal Midlands.

Blood samples were collected from sheep on 24 farms in the Natal Midlands to ascertain the selenium, copper and zinc status of sheep kept under intensive grazing conditions on cultivated pastures in this region. The mean erythrocyte glutathione peroxidase activity was 34.1 enzyme units (EU: nmol NADPH oxidised min-1 mg-1 haemoglobin). A total of 59.4% of the samples contained less than 30 EU, a level below which a marginal deficiency may exist. The mean selenium concentration in whole blood was 0.57 mumol l-1. Sixty four per cent of the samples contained less than 0.63 mumol l-1, a level below which the animals were considered to be marginally deficient. The mean copper concentration in plasma was 16.1 mumol l-1 and that of zinc 15.0 mumol l-1. On none of the farms was the copper concentration in plasma below the concentrations accepted to represent a marginal deficiency, and ewes on only one farm had relatively low plasma zinc concentrations. It is concluded that many sheep grazing cultivated pastures in the Natal Midlands may be marginally deficient in selenium. However, the selenium status in sheep should be determined on individual farms before supplementation is recommended, as external sources of selenium are often supplied, mostly unintentionally. Seasonal variations in blood selenium concentrations did not follow a specific trend, probably because the sheep were grazing cultivated pastures for most of the year and feeding practices differed from farm to farm. It is therefore suggested that the selenium status of sheep be determined at the pre-mating and pre-lambing stages rather than in a specific season of the year.

Animals↗
PubMed2004

[Selenium safety in children with protracted diarrhea syndrome].

The insufficient selenium safety was revealed in 27% of the children without signs of intestinal absorption damage surveyed in Novokuznetsk. Patients with coeliac disease differ doubtfully on a parameter of selenium safety from patients of control group whereas serum selenium level rises while keeping gluten free diet. Selenium insufficiency was observed approximately in 2/3 of children with allergic enteropathia and intestinal absorption damage of obscure origin. It is supposed, that the basic reason of selenium insufficiency in children with protracted diarrhea is a violation of intestinal protein absorption. The assumption failed that exception of grain products from diet in coeliac disease leads to selenium insufficiency. Children suffering from protracted diarrhea may need in correction of their selenium status.

Adolescent↗
PubMed2004

Chromatographic speciation of anionic and neutral selenium compounds in Se-accumulating Brassica juncea (Indian mustard) and in selenized yeast.

Selenium-accumulating plants such as Brassica juncea (Indian mustard) concentrate the element in plant shoots and roots. Such behavior may provide a cost-effective technology to clean up contaminated soils and waters that pose major environmental and human health problems (phytoremediation). Such ability to transform selenium into bioactive compounds has important implications for human nutrition and health. Element selective characterization of B. juncea grown in the presence of inorganic selenium under hydroponic conditions provides valuable information to better understand selenium metabolism in plants. The present work determines both previously observed organoselenium species such as selenomethionine and Se-methylselenocysteine and for the first time detects the newly characterized S-(methylseleno)cysteine in plant shoots and roots when grown in the presence of selenate or selenite as the only selenium source. A key feature of this study is the complementary role of selenium and sulfur specific chromatographic detection by HPLC with interfaced inductively coupled plasma mass spectrometry (ICP-MS) detection and by derivatization GC with interfaced atomic spectral emission. HPLC-ICP-MS limits of detection for such species were in the range 5-50 ng Se mL(-1) in the injected extracts. Speciation profiles are compared with those of selenium-enriched yeast by both HPLC-ICP-MS and GC-AED.

Anions↗
PubMed2005

Selenium status, pregnancy outcomes, and mother-to-child transmission of HIV-1.

BACKGROUND: Among HIV-infected pregnant women, low selenium status may increase risk of mother-to-child transmission (MTCT) of HIV and poor pregnancy outcomes (low birthweight, small for gestational age, preterm birth, and fetal death) through several mechanisms, such as by promoting maternal HIV disease progression, viral shedding in the genital tract, and development of mastitis. However, there is no direct epidemiologic evidence on these relations among HIV-infected pregnant women. OBJECTIVE: To investigate the association between selenium status during pregnancy and pregnancy outcomes, MTCT of HIV, and child mortality. DESIGN: Baseline plasma selenium measurements from HIV-positive pregnant women (n = 670) were obtained between 12-27 weeks of gestation and mother-child pairs were followed prospectively until 24 months after delivery. RESULTS: Low plasma selenium levels were associated with increased risks of fetal death, child death, and HIV transmission through the intrapartum route. Low selenium status was not associated with risks of low birthweight or preterm birth but was associated with an apparently lower risk of small for gestational age. CONCLUSION: Adequate selenium status may be beneficial for some but not all pregnancy outcomes. Further studies are needed to better understand the role of selenium status in pregnancy outcomes, HIV transmission, and child health.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Selenium: the biological role and antioxidant activity].

Selenium is essential trace element, sulphur analogue with high chemical activity, component of some selenoproteins and enzymes: glutathione peroxidase and other peroxidases, blood and tissue proteins. As to their biological action mechanism selenium and its compounds are antioxidants. Selenium is active immunomodulator, much more potent anti-oxidant than vitamins E, C and A, beta-carotene, but much more toxic. It takes part in thyroxine conversion to triiodethyronine in thyroid hormone biosynthesis. As sperm antioxidant selenium protected its motility and fertility. Selenium is a serious factor of biological and antioxidant protection of vascular endothelium, of low-density lipoproteins, protection of DNA, chromosomes. As food component selenium is an exceptional agent of protection from atherosclerosis, coronary ischemic disease and cancer. Some hydrobionts, liver, kidney, meal, corn and garlic, onion, cabbage, broccoli are dietary products with high content of selenium.

Animals↗
PubMed2005

The influence of different factors on selenium levels in dairy cow herds in the central-eastern region of Poland.

Selenium has been recognised as a basic bioelement that determines normal development and health of animals and humans alike. Studies of many authors revealed the influence of selenium deficiency on immunity, health, reproduction and production of dairy cows. Selenium deficiency have been reported in a number of countries, for example in different regions of Poland. The aim of the study was to determine the Se levels in blood serum of dairy cows in the Lublin region. In the periods: autumn 2003, winter 2003 and autumn 2004 selenium concentrations were investigated in serum samples from 180 dairy cows. The samples were obtained from 11 farms. The selenium concentrations were estimated with the ASA method. The monitoring studies have found that Se serum levels are dependent on season of the year, physiological period, maintenance systems and methods of feeding. Mean selenium serum levels observed in the study were between 0.21-0.92 micromol/l, especially (micromol/l): lactation 0.74 +/- 0.13, drying-off period 0.67 +/- 0.15, autumn 2003 0.38 +/- 0.17, winter 2003 0.48 +/- 0.16, autumn 2004 0.69 +/- 0.18. These results suggest that selenium should be supplemented, especially in high-producing dairy cow herds.

Animal Feed↗
PubMed2005

[Effects of selenium on Chamaecrista rotundifolia growth, nutrient absorption and nitrogen-fixing ability].

In this paper, a field experiment was conducted on a red soil of South China to study the effects of applying selenium fertilizer on the growth, forage quality and nitrogen-fixing ability of Chamaecrista rotundifolia. The results showed that applying 75, 150, 225 and 300 g Se x hm(-2) could increase the plant height, branch number, dry root weight and dry forage yield by 0.3% - 6.2%, 65.1% - 79.5%, 155% - 252% and 30.6% - 54.1%, respectively. The total nitrogen, total phosphorus and total potassium contents of plant were increased by 21.79% - 41.46%, 20.74% - 34.67% and 34.3% - 62.4%, respectively, and the raw protein, raw fat, raw fiber and amino acid contents were increased by 21.79% - 41.46%, 1.4% - 89.6%, 34.1% - 56.6% and 6.33% 63.24%, respectively. Among the 4 doses, 150 g Se x hm(-2) was the most effective and suitable application amount. The selenium content in plant after applying 300 g Se x hm(-2)(S4) was 0.695 mg x kg(-'), with an increase of 0.658 mg x kg(-1) compared to no selenium fertilization. There was a significantly positive correlation between plant selenium content and applied selenium (R2 = 0.9666**). The root nodule weight, number and nitrogenase activity in treatment 150 g Se x hm(-2)(S2) were respectively 131.7%, 114.3% and 1417.9% higher than those of no selenium fertilization. The correlation between applied selenium and nitrogenase activity was also significant (R2 = 0.9606*).

Biomass↗
PubMed2005

Intravenous selenium modulates L-arginine-induced experimental acute pancreatitis.

CONTEXT: Oxidative stress is understood to have a critical role in the development of acinar injury in experimental acute pancreatitis. We have previously demonstrated that compound multiple antioxidant therapy ameliorates end-organ damage in the intra-peritoneal L-arginine rat model. As the principal co-factor for glutathione, selenium is a key constituent of multiple antioxidant preparations. OBJECTIVE: The intention of this study was to investigate the effect of selenium on pancreatic and remote organ injury in a well-validated experimental model of acute pancreatitis. METHODS: Male Sprague-Dawley rats were randomly allocated to one of 3 groups (n=5/group) and sacrificed at 72 hours. Acute pancreatitis was induced by 250 mg per 100 g body weight of 20% L-arginine hydrochloride in 0.15 mol/L sodium chloride. Group allocations were: Group 1, control; Group 2, acute pancreatitis; Group 3, selenium. MAIN OUTCOME MEASURES: Serum amylase, anti-oxidant levels, bronchoalveolar lavage protein, lung myeloperoxidase activity, and histological assessment of pancreatic injury. RESULTS: L-arginine induced acute pancreatitis characterised by oedema, neutrophil infiltration, acinar cell degranulation and elevated serum amylase. Selenium treatment was associated with reduced pancreatic oedema and inflammatory cell infiltration. Acinar degranulation and dilatation were completely absent. A reduction in bronchoalveolar lavage protein content was also demonstrated. CONCLUSION: Intravenous selenium given 24 hours after induction of experimental acute pancreatitis was associated with a reduction in the histological stigmata of pancreatic injury and a dramatic reduction in broncho-alveolar lavage protein content. Serum selenium fell during the course of experimental acute pancreatitis and this effect was not reversed by exogenous selenium supplementation.

Acute Disease↗
PubMed1990

Effects of selenium on RNA synthesis and content in rat pancreas.

In order to investigate the effect of selenium supplementation on RNA in the rat pancreas, the rate of in vitro incorporation of [3H]uridine into RNA by pancreas slices derived from two groups of rats fed either a low-selenium diet or a diet supplemented with 0.25 mg/kg selenium as selenite was examined. The RNA and lipid peroxide contents and glutathione peroxidase activity in homogenates from the pancreas were also determined. After feeding for 12-14 weeks, the rates of [3H]uridine incorporation were significantly higher in the pancreatic tissue from the selenium-supplemented diet group. Concomitantly, an increase in glutathione peroxidase activities and RNA content, and a reduction of lipid peroxides, were also found in the pancreatic tissue of the selenium-supplemented group. The results suggest that selenium supplementation at a level of 0.25 mg/kg selenium could promote RNA synthesis with an increase in glutathione peroxidase activity and a decrease of lipid peroxides.

Animals↗
PubMed1990

Hepatic selenium concentration in pigs with microangiopathy (mulberry heart disease)--an animal model for the study of oxidative damage.

The significance of selenium deficiency was investigated in pigs that died suddenly of microangiopathy (MAP, mulberry heart disease). Hepatic selenium concentration (mean +/- SD) in pigs with MAP (1.04 +/- 0.47 micrograms/g dry weight) was lower than in healthy pigs (1.23 +/- 0.53 micrograms/g). The lowest hepatic selenium values were found in pigs with MAP and in 22.2% of MAP pigs hepatic selenium concentration was below 0.5 microgram/g which reflects selenium deficiency. Thus, pigs with a low selenium status are at risk of MAP. The low selenium status together with vitamin E deficiency increases oxidative stress and thus contributes to the development of oxidative damage.

Animals↗