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Se Levels (se + level)
Selected AbstractsFragile Self-Esteem in Children and Its Associations With Perceived Patterns of Parent-Child CommunicationJOURNAL OF PERSONALITY, Issue 2 2000Michael H. Kernis We examined the extent to which 11- to 12-year-old children' (N= 174) self-esteem (SE) stability and level related to their perceptions of various aspects of parent-child communication. Compared to children with stable SE, children with unstable SE reported that their fathers were more critical and psychologically controlling, and less likely to acknowledge their positive behaviors or to show their approval in value-affirming ways. Likewise, children with low SE reported that their fathers exhibited these qualities to a greater extent than did children with high SE. In addition, fathers of children with stable high SE were viewed as especially good at problem solving. Children' SE level related to perceptions of mothers' communication styles very similarly to how it did with fathers'; with respect to SE stability, however, relationships were generally less consistent and frequently absent. Discussion centered on the role of parent-child communication in promoting unstable SE. [source] Seasonal fluctuations of selenium and sulfur accumulation in selenium hyperaccumulators and related nonaccumulatorsNEW PHYTOLOGIST, Issue 3 2007Miriam L. Galeas Summary ,,Some plants hyperaccumulate selenium (Se) up to 1% of dry weight. This study was performed to obtain insight into whole-plant Se fluxes in hyperaccumulators. ,,Selenium hyperaccumulators Astragalus bisulcatus and Stanleya pinnata were monitored over two growing seasons for seasonal fluctuations in concentrations of Se and the chemically similar element sulfur (S). The related nonhyperaccumulators Astragalus sericoleucus, Oxytropis sericea and Thlaspi montanum were included for comparison. ,,In both hyperaccumulators leaf Se decreased from April to October, coinciding with Se hyperaccumulation in flowers and seeds. Root Se levels were lowest in summer. Selenium concentration decreased with leaf age in both hyperaccumulators. Leaf S levels peaked in summer in all plant species, as did Se levels in nonhyperaccumulators. Selenium and S levels tended to be negatively correlated in hyperaccumulators, and positively correlated in nonhyperaccumulators. ,,These results suggest a specific flow of Se in hyperaccumulator plants over the growing season, from root to young leaves in spring, followed by remobilization from aging leaves to reproductive tissues in summer, and back to roots in the autumn. [source] High-throughput quantification of selenium in individual serum proteins from a healthy human population using HPLC on-line with isotope dilution inductively coupled plasma-MSPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 19 2010Sophia Letsiou Abstract In this study, a method, based on dual column affinity chromatography hyphenated to isotope dilution inductively coupled plasma,quadrupole MS, was developed for selenium determination in selenoprotein P, glutathione peroxidase, and selenoalbumin in human serum samples from a group of healthy volunteers (n=399). Method improvement was achieved using methanol-enhanced isotope dilution which resulted in improved sensitivity and removal of isobaric interferences. Although no human serum reference materials are currently certified for their selenium species levels, method development was conducted using human serum reference material BCR 637 and 639 as their Se species content has been reported in the previous studies, and thus comparisons were possible. The mean selenium concentrations determined for the 399 healthy volunteer serum samples were 23±10,ng Se mL,1 for glutathione peroxidase, 49±15,ng Se mL,1 for selenoprotein P and 11±4,ng Se mL,1 for selenoalbumin. These values are found to be in close agreement with published values for a limited number of healthy volunteer samples, and to establish baseline Se levels in serum proteins for an apparently healthy group of individuals, thus allowing for subsequent comparisons with respective values determined for groups of individuals with selenium related health issues, as well as assist in the discovery of potential selenium biomarkers. Also, the relationship between Se serum protein levels and some anthropometric characteristics of the volunteer population were investigated. Additionally, further development of the analytical method used in this study was achieved by adding a size exclusion chromatography column after the two affinity columns via a switching valve. This allowed for the separation of small selenium-containing molecules from glutathione peroxidase and thus enhanced the overall confidence in its identification. [source] The effects of dietary organic or inorganic selenium in rainbow trout (Oncorhynchus mykiss) under crowding conditionsAQUACULTURE NUTRITION, Issue 6 2009F.Z. KÜÇÜKBAY Abstract In the present study, the effects of different sources of selenium (Se; sodium selenite or selenomethionine) supplementation on the growth and serum concentrations of oxidative stress markers [malondialdehyde (MDA), 8-isoprostane, glutathione peroxidase (GSH-Px) activity] and muscle Se, MDA and heat shock protein 70 (Hsp70) levels in rainbow trouts were evaluated. The fish (n = 360; 0 + years old) with initial average weight of 20 ± 0.8 g were randomly assigned to 12 treatment groups consisting of 3 replicates of 10 fish each in a 2 × 2 × 3 factorial arrangement of treatments (stocking densities, Se sources, Se levels). The fish were kept at low (25 kg m,3) or high (100 kg m,3) stocking densities and fed a basal (control) diet or the basal diet supplemented with either 0.15 or 0.30 mg of Se kg,1 of diet from two different forms: sodium selenite or selenomethionine. High stocking density decreased weight gain, feed intake and feed conversion ratio (FCR) when basal diet was fed (P = 0.001). A linear increase in feed intake and weight gain and improvement in FCR were found in sodium selenite (P = 0.01)- or selenomethionine (P = 0.001)-supplemented fish reared under crowding conditions. Serum and muscle Se levels and serum GSH-Px activity increased (P = 0.001) linearly, whereas serum and muscle MDA concentrations and serum 8-isoprostane decreased linearly as dietary sodium selenite (P = 0.01) or selenomethionine (P = 0.001) supplementation increased. Selenomethionine and sodium selenite supplementation decreased Hsp70 in the muscle of fish reared under crowding conditions (P < 0.05). Supplementation with Se improved growth and antioxidant status of fish and the effects of selenomethionine were relatively greater than sodium selenite in the crowded groups. Results suggest that crowding conditions cause significant detrimental effects in rainbow trout indicated by increased oxidative stress, reduced feed intake and body weight gain. ,t also indicates that dietary Se supplementation offers a feasible way of reducing the losses in performance of rainbow trout reared under crowding conditions. Selenomethionine seems to be more effective than sodium selenite and the higer dose in the present study also seems to be more effective than the lower dose. [source] Hyperaccumulation of selenium in hybrid striped bass: a functional food for aquaculture?AQUACULTURE NUTRITION, Issue 3 2008P.A. COTTER Abstract One method of increasing the value of aquacultured product is to produce fillets that are fortified with minerals that are beneficial to human health , that is enhance the functionality of an already healthy product. A good candidate mineral in this regard is selenium (Se) which is of vital importance to normal metabolism in humans. In order to evaluate the dose response and tissue accumulation of supplemental dietary Se, a study was undertaken with hybrid striped bass (HSB). Animals were fed diets supplemented with either organic (0,3.2 mg kg,1 as SelPlex®) or inorganic (0.2 and 0.4 mg kg,1 as sodium selenite) Se for 6 weeks. Because basal fishmeal-based diets contained 1.22 mg Se kg,1, doses of Se delivered equated to 1.22,4.42 mg kg,1. At trial end, greatest weight gain was observed in fish receiving 0.2 mg Se kg,1, irrespective of form (organic/inorganic). Se accumulation in HSB liver and fillet revealed a classical dose-response once a threshold level of 0.2 mg Se kg,1 was surpassed. Greatest tissue accumulation of Se was observed in fish fed the 3.2 mg Se kg,1 level (P > 0.0001). A 100 g portion of Se-enhanced HSB fillet would contain between 33 and 109 ,g Se, amounting to a dietary intake of between 25 and 80 ,g Se; a level that would satisfy present daily intake recommendations. Comparison of tissue Se levels indicated that the muscle provides a more conspicuous gauge of dietary Se dose-response than does liver. Dietary treatments of between 0.4 and 1.6 mg organic Se kg,1 reduced (P < 0.024) plasma glutathione peroxidase (GSH-Px) activity. No differences were observed in ceruloplasmin, lysozyme or GSH-Px activities between organic and inorganic Se when delivered at the 0.2 mg Se kg,1 level. Ceruloplasmin, lysozyme and GSH-Px levels were elevated (P , 0.025) in fish fed the diet containing 0.4 mg inorganic Se kg,1. [source] Dietary selenium requirement for juvenile cobia, Rachycentron canadum L.AQUACULTURE RESEARCH, Issue 10 2010Kang Liu Abstract A 10-week feeding trial was conducted to estimate the optimum dietary selenium (Se) requirement for juvenile cobia, Rachycentron canadum L. The basal diet was formulated to contain 50.6% crude protein from vitamin-free casein, gelatin. A control diet (no added seleno- dl -methionine) and five experimental diets containing 0.20, 0.40, 0.60, 0.80 and 1.00 mg seleno- dl -methionine kg,1 were prepared. Each diet was randomly fed to triplicate groups of juvenile cobia with initial weight 6.27±0.03 g in a flow-through system. The Se concentration in rearing water was monitored during the feeding period, and was not detectable. The dietary Se level significantly influenced the survival, specific growth rate (SGR), feed efficiency and the Se concentrations in the whole body and vertebra of cobia. The Se-dependent glutathione peroxidase (EC 1.11.119) activity increased with an increase in the dietary Se levels (P<0.05). Hepatic glutathione reductase (EC 1.6.4.2) activity was the highest in fish fed the diet with 0.21 mg Se kg,1, and declined with an increase in the dietary Se levels. Based on broke-line regression of SGR, the Se concentration in the whole body and vertebra, the Se requirements of juvenile cobia were 0.788, 0.811 and 0.793 mg Se kg,1 diet in the form of seleno- dl -methionine respectively. [source] Role of selenium in regulation of spermatogenesis: Involvement of activator protein 1BIOFACTORS, Issue 3 2005Sonia Shalini Abstract Selenium (Se) is involved in the process of male reproduction. Several studies have been carried out to find the mechanism of Se action through identified selenoproteins. Especially selenoenzyme phospholipid glutathione peroxidase (PHGPx, GPx-4) plays a pivotal role in regulating spermatogenesis. However, the action of selenium is best known as an antioxidant which acts through various selenoproteins viz. glutathione peroxidase, thioredoxin reductase and selenoprotein P. Oxidative stress is currently being considered a leading cause of male infertility. Presently, the involvement of redox active transcription factor, AP1 (Activator protein1) in testicular function was studied. AP1 is redox sensitive and also controls cell proliferation. The effects of Se might be mediated through it. Different Se status - deficient, adequate and excess Se - were generated in male Balb/c mice by feeding yeast based selenium deficient diet and deficient diet supplemented with Se as sodium selenite (0.2 and 1 ppm Se), respectively, for a period of 4 and 8 weeks. Se status was checked by measuring the Se levels and glutathione peroxidase (GSH-Px) activity in testis and liver. The reproductive potential of mice was affected at these changed Se levels. Changes in the activity of superoxide dismutase (SOD), levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) were observed indicating increased oxidative stress at both the levels. Further, changes in the mRNA expression of GSH-Px, ,-glutamylcysteine synthetase ,GCS) and Mn superoxide dismutase (MnSOD) were observed. Decrease in cjun and cfos mRNA levels were observed at both the Se status (deficient and excess) which might be responsible for decreased germ cell number, differentiation and reduced fertility observed at the altered Se levels. [source] | |||||||||||||