Plasma Se Levels Research Articles

Selenium Deficiency as a Possible Contributor of Goiter in Schoolchildren of Isfahan, Iran

The prevalence of goiter still remains high in some areas of Iran in spite of iodine supplementation. In the present study, we investigated the role of selenium (Se) deficiency in the etiology of goiter in Isfahan. Two thousand three hundred thirty-one schoolchildren were selected by multistage random sampling. Thyroid size was estimated in each child by inspection and palpation. Urinary iodine concentration (UIC) and plasma Se were measured. Overall, 32.9% of the 2,331 children had goiter. The median UIC was 19.55 microg/dl. Plasma Se was measured in 96 goitrous and 72 nongoitrous children. The mean +/- SD of plasma Se in goitrous and nongoitrous children was 66.86 +/- 21.82 and 76.67 +/- 23.33 microg/l, respectively (P = 0.006). Goitrous girls had lower plasma Se level than nongoitrous girls (65.62 +/- 21.64 vs. 76.51 +/- 22.61 microg/dl, P = 0.02). Goitrous boys had lower plasma Se level than nongoitrous boys (68.45 +/- 22.21 vs. 76.91 +/- 24.76 microg/l, P = 0.14). The prevalence of Se deficiency was significantly higher in goitrous boys and girls than nongoitrous children. Se deficiency is among the contributors of goiter in Isfahan goitrous schoolchildren. However, the role of other micronutrient deficiencies or goitrogens should be investigated in this region.

Effect of supplementation with Se-enriched yeast and factors influencing Se concentration in plasma of transplant recipients

The aim of this study was to assess the bioavailability of selenium (Se) in Se-enriched yeast and the possible impact of age, sex and area of residence on the Se concentration in plasma in 179 transplant recipients, as Se clinical effects in the prevention of cutaneous epithelial lesions in organ transplant recipients has been reported elsewhere. Subjects were randomized to receive either 200 μg Se/day (group 1:91 patients) or placebo (group 2: 88 patients) for 3 years. Plasma Se levels were measured at the beginning of the study and after 4, 12, 24 and 36 months of Se or placebo supplementation. Initial plasma Se levels were 90.9±26.1 μg/L for placebo and 94.0±25.3 μg/L for Se-supplemented groups. At baseline, the Se level was not linked to sex and age but to area of residence, although the number of subjects in each area was insufficient to draw any conclusions. Plasma Se levels were statistically lower in cases of liver transplant compared to kidney and heart transplant ( p=0.03). Over the 3-year period of supplementation, plasma Se in the supplemented subjects was significantly higher than in the placebo group ( p<0.01) and there was an interaction ( p<0.01) between supplementation and time for plasma Se. Supplementation with Se-enriched yeast significantly increased the Se concentration in plasma of the patients to a plateau: the mean plasma Se of the Se-supplemented patients increased to 164.7±35.8 μg/L at 4 months and then remained similar at 12 (176.1±48.3 μg/L), 24 (176.1±54.2 μg/L) and 36 (182.2±46.4 μg/L) months.

Effects of Acute Swimming Exercise on Some Elements in Rats

The objective of the present study is to explore the effects of acute swimming exercise on plasma levels of some elements in rats, immediately after the exercise, and 24 and 48 h later. The study included 40 adult male rats of Spraque Dawley species, which were equally allocated to four groups. Group 1: General Control Group; Group 2: Swimming Group, the group that was decapitated immediately after 30-min acute swimming exercise; Group 3: Swimming Group, the group that was decapitated 24 h after 30-min acute swimming exercise; Group 4: Swimming Group, the group that was decapitated 48 h after 30-min acute swimming exercise. Plasma copper (Cu), iron (Fe), magnesium (Mg), phosphorus (P), selenium (Se), zinc (Zn) levels were determined according to atomic emission method in the blood samples collected from the animals by decapitation method. Measurements conducted immediately after acute swimming exercise (group 2) showed a significant decrease in Se and Zn levels (p < 0,01) and a significant increase in P levels (p < 0,01), when compared to group 1. Measurements carried out 24 h after the exercise (group 3) demonstrated a significant increase in all parameters except for Mg, in comparison to groups 1 and 2 (p < 0,01). It was seen in the measurements made 48 h after the exercise (group 4) that all parameters were restored to control values. The results of our study show that acute swimming exercise significantly changes plasma Cu, Fe, P, Se, and Zn levels.

Selenium Status of the Australian Population: Effect of Age, Gender and Cardiovascular Disease

Selenium (Se) is an essential trace element and the clinical consequences of Se deficiency have been well-documented. Se is primarily obtained through the diet and recent studies have suggested that the level of Se in Australian foods is declining. Currently there is limited data on the Se status of the Australian population so the aim of this study was to determine the plasma concentration of Se and glutathione peroxidase (GSH-Px), a well-established biomarker of Se status. Furthermore, the effect of gender, age and presence of cardiovascular disease (CVD) was also examined. Blood plasma samples from healthy subjects (140 samples, mean age = 54 years; range, 20-86 years) and CVD patients (112 samples, mean age = 67 years; range, 40-87 years) were analysed for Se concentration and GSH-Px activity. The results revealed that the healthy Australian cohort had a mean plasma Se level of 100.2 +/- 1.3 microg Se/L and a mean GSH-Px activity of 108.8 +/- 1.7 U/L. Although the mean value for plasma Se reached the level required for optimal GSH-Px activity (i.e. 100 microg Se/L), 47% of the healthy individuals tested fell below this level. Further evaluation revealed that certain age groups were more at risk of a lowered Se status, in particular, the oldest age group of over 81 years (females = 97.6 +/- 6.1 microg Se/L; males = 89.4 +/- 3.8 microg Se/L). The difference in Se status between males and females was not found to be significant. The presence of CVD did not appear to influence Se status, with the exception of the over 81 age group, which showed a trend for a further decline in Se status with disease (plasma Se, 93.5 +/- 3.6 microg Se/L for healthy versus 88.2 +/- 5.3 microg Se/L for CVD; plasma GSH-Px, 98.3 +/- 3.9 U/L for healthy versus 87.0 +/- 6.5 U/L for CVD). These findings emphasise the importance of an adequate dietary intake of Se for the maintenance of a healthy ageing population, especially in terms of cardiovascular health.

Effect of Different Levels of Selenium Supplementation on Growth Rate, Nutrient Utilization, Blood Metabolic Profile, and Immune Response in Lambs

Eighteen male lambs (8-9 months of age, 25.00 +/- 0.90 kg body weight) were divided into three groups of six animals in each and fed a total mixed ration (TMR) containing concentrate mixture (30% maize grain, 27% soybean meal, 40% wheat bran, 2% mineral mixture, and 1% common salt) and wheat straw in 65:35 ratio and supplemented with selenium (Se) as sodium selenite at 0 (T1, control), 0.15 (T2), and 0.30 ppm (T3) levels. Experimental feeding was done for a period of 90 days including a 6-day metabolism trial. To assess the growth performance, lambs were weighed every 15 days throughout the experimental period. All the lambs were intramuscularly inoculated with a single dose (2 ml) of haemorrhagic septicaemia oil adjuvant vaccine on 0 day to evaluate the humoral immune response. Blood samples were collected on 0 day and thereafter at 30 days interval. Results revealed that supplementation of Se both at 0.15 and 0.30 ppm levels had no significant (P > 0.05) effect on intake and digestibility of dry matter, organic matter, crude protein (CP), ether extract, neutral detergent fiber, acid detergent fiber, and hemicellulose; balances of calcium and phosphorus; and level and intake of digestible CP and total digestible nutrients. Se supplementation also had no significant (P > 0.05) effect on the levels of serum total cholesterol, total protein, albumin, globulin, albumin/globulin ratio, tri-iodothyronine (T(3)), thyroxine (T(4)), and T(4)/T(3) ratio; and serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase enzyme activity in the lambs. However, there was a significant (P < 0.05) increase in the plasma Se levels, red blood cell glutathione peroxidase enzyme activity, and humoral immune response in both the Se-supplemented groups. Feed (TMR) required per kilogram gain was less by 11.1% and 16.5% in groups T2 and T3, respectively, as compared to control (T1) group. Average daily gain was highest (108.5 g) in group T3, followed by group T2 (98.2 g), and lowest (89.06 g) in the control group (T1). These results indicated that supplementation of 0.15 and 0.3 ppm Se in the diet (having 0.19 ppm Se) of lambs significantly improves their immune response and antioxidant status.

Total plasma carotenoids and mortality in the elderly: results of the Epidemiology of Vascular Ageing (EVA) study

Carotenoids are pigments found in fruits and vegetables. While high intakes of fruits and vegetables have been found to be associated with lower mortality, our objective is to investigate if total plasma carotenoids, via their antioxidant properties, are associated with mortality risk in a free-living elderly population. The 'Epidemiology of Vascular Ageing' (EVA) study (n 1389; 59-71 years) is a 9-year longitudinal study with six waves of follow-up. The association between baseline total plasma carotenoids and mortality was determined by Cox proportional hazards regression analyses. Low total plasma carotenoid level was significantly associated with all-cause mortality in men but not in women. After controlling for potential confounding factors, mortality risk increased significantly in men (P = 0.03) with plasma carotenoids in the lowest quintile compared with men with plasma carotenoids in the highest (relative risk 2.94 (95% CI 1.21, 7.17)). A significant association between mortality by cancer and low plasma carotenoid level variable was also found in men (unit = 1 micromol/l; relative risk 1.72 (95% CI 1.02, 2.86); P = 0.01). Associations between total plasma carotenoids and mortality risk remained statistically significant after taking into account: (1) plasma Se level, which previously was found associated with mortality in this population and (2) thiobarbituric acid-reactive substances level considered as an indicator of oxidative stress. By showing, prospectively, in a general healthy elderly population, that total plasma carotenoid levels were independently associated with mortality risk in men, the present study suggests that total plasma carotenoid levels could be a health indicator in elderly populations.

The Nutritional Prevention of Cancer: 400 Mcg Per Day Selenium Treatment

Nonexperimental studies suggest that individuals with higher selenium (Se) status are at decreased risk of cancer. The Nutritional Prevention of Cancer (NPC) study randomized 1,312 high-risk dermatology patients to 200-mcg/day of Se in selenized yeast or a matched placebo; selenium supplementation decreased the risk of lung, colon, prostate, and total cancers but increased the risk of nonmelanoma skin cancer. In this article, we report on a small substudy in Macon, GA, which began in 1989 and randomized 424 patients to 400-mcg/day of Se or to matched placebo. The subjects from both arms had similar baseline Se levels to those treated by 200 mcg, and those treated with 400-mcg attained plasma Se levels much higher than subjects treated with 200 mcg. The 200-mcg/day Se treatment decreased total cancer incidence by a statistically significant 25%; however, 400-mcg/day of Se had no effect on total cancer incidence.

Absence of diabetes indicators in a selenium‐supplementation trial

We conducted a yr‐long intervention with selenium (Se) to characterize dose‐response relationships of biomarkers of Se status. Volunteers from Grand Forks, ND, were screened by interview, medical history and clinical biochemistry; individuals with liver or renal dysfunction, uncontrolled hypertension, unmanaged diabetes, or BMI&gt;40 were ineligible. Of those eligible, 261 (106 men, 155 women) were randomized to Se supplements (0, 50, 100 or 200 ug Se [as L‐selenomethionine]/day). Baseline plasma Se levels were relatively high (141.5±23.7 ng/ml), with &gt;50% in the upper quintile of the NHANES III cohort, and 6% in the range achieved only by Se supplementation in the NPC trial. As secondary analyses of those studies have suggested associations of plasma Se level and diabetes risk, we evaluated that relationship in our cohort. At baseline, 15 subjects reported having diabetes and/or using diabetic medications; they showed higher (P&lt;0.05) fasting glucose levels (120±25 mg/dl) than subjects without apparent diabetes (88±9 mg/dl), but similar plasma Se levels (132.4±18.3 ng/ml vs. 142.6±23.7 ng/ml) with cases similarly distributed over the tertiles of baseline plasma Se. Subjects without apparent diabetes showed similar fasting glucose levels across those tertiles (low: 86.4±9.0 mg/dl; mid: 87.5±8.3 mg/dl; high: 90.2±10.1 mg/ml). These results do not support a relationship of Se status and diabetes risk.

Immune Response and Plasma Alpha Tocopherol and Selenium Status of Male Buffalo (Bubalus bubalis) Calves Supplemented with Vitamin E and Selenium

An experiment was conducted using 20 male buffalo calves to study the effect of vitamin E and selenium supplementation on their immune response and plasma α-tocopherol and selenium status. These buffalo calves (10-12 months old, average body weight 75.30±2.20 kg) were randomly allotted to four treatments on the basis of their body weights and were fed on wheat straw and concentrate mixture to meet their nutrient requirements of 500 g/d body weight gain. The buffalo calves were fed either a control diet (neither supplemented with Se nor VE) or diets supplemented with Se at 0.3 ppm (+Se), DL-alpha tocopheryl acetate at 300 IU (+VE), and both DL-alpha tocopheryl acetate at 300 IU and Se at 0.3 ppm (+Se+VE). These experimental diets were fed for 180 days. Blood samples were collected at day 0 and subsequently at 45 day intervals up to 180 days of experimental feeding to monitor plasma α-tocopherol and Se concentrations. To assess humoral immune response, all calves were sensitized with formalin inactivated Pasteurella multocida antigen at 135 days of experimental feeding and blood was collected on 0, 7, 14, 21 and 28 days post vaccination (DPV) to measure antibody production using indirect ELISA. Cell mediated immune response of calves was assessed after 180 days of experimental feeding by in viva delayed type hypersensitivity (DTH) reaction using phytohaemaglutinin-P (PHA-P) as a mitogen. Results revealed that feeding of VE and Se improved the plasma levels of these nutrients. Plasma levels of Se were affected by supplementation of both VE (p<0.001) and Se (p<0.001); however, no interaction (SexVE) was observed. Supplementation of Se improved the humoral immune response (p<0.008), whereas, VE showed a tendency towards improvement in cell mediated immune response (p<0.064). It was concluded that vitamin E and Se supplementation improved the status of these micronutrients and humoral immune response in buffalo calves.

Effects of Selenium Supplementation on Antioxidant Defense and Glucose Homeostasis in Experimental Diabetes Mellitus

The objective of this study was to investigate the effects of different forms of Se supplementation on the antioxidant defense and glucose homeostasis in experimental diabetes. Sodium selenate (SS) or selenomethionine (SM) were administered (2 micromol Se kg(-1) day(-1)) via orogastric route to streptozotocine (STZ)-induced diabetic rats in addition to basal diet for 12 weeks. Glucose levels in whole blood, glutathione peroxidase (GSH-Px) activity in erythrocytes, Se and fructosamine levels in plasma were evaluated monthly. Plasma Se levels increased significantly in all diabetic groups compared to basal measurements, being more prominent in SM group [p(SM(3)/SM(0)) = 0.018]. The increase in GSH-Px activities was significant at the end of the second month in SS [p(SS(2)/SS(0)) = 0.028], whereas at the end of the third month in SM the value was lower [p(SM3/SM0) = 0.018] and the unsupplemented diabetic control (DC) groups, p(DC(3)/DC(0)) = 0.012. Glucose increased significantly only in DC group. Fructosamine increased gradually in all diabetic groups, being significant in DC and SS groups. At the end of the third month, highest fructosamine levels were observed in SS group, which were significantly higher than the SM group [p(SM/SS) = 0.010]. In conclusion, Se augmented the antioxidant defense by increasing GSH-Px activity and this effect was more prominent when Se was supplemented as SM, which exerted positive effects also on glucose homeostasis.

Increased plasma selenium levels correlate with elevated resistance of Heliothis virescens larvae against baculovirus infection

We reported that dietary selenium (Se) impacted the growth and development of Trichoplusia ni reared for many generations on diet containing extremely low levels of Se. Larvae had an elevated resistance to per os infection with a baculovirus. In this study, we examine how dietary Se (in the form of selenite) affects the growth, development, and Se content of Heliothis virescens that have been laboratory reared for less than two years. Larvae fed a commercial tobacco budworm diet supplemented with greater than 20 ppm Se grew at a slower rate than insects fed lower levels of Se and had an increase in the amount of Se sequestered in pupae. Larvae fed diets containing from 10–60 ppm Se exhibited elevated plasma concentrations of the micronutrient and increased plasma virucidal activity against Helicoverpa zea single nucleopolyhedrovirus (HzSNPV). Larvae reared on diet supplemented with 10 or 60 ppm Se until the onset of the penultimate instar were then infected per os or by injection with increasing concentrations of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). Larvae fed dietary Se and infected with occluded virus per os displayed a significantly lower mortality compared with infected larvae not fed Se. Our results suggest that dietary Se levels are directly correlated with plasma Se levels, and that plasma Se levels are in turn correlated with baculovirus resistance.

Red blood cell and plasma glutathione peroxidase activities and selenium concentration in patients with chronic kidney disease: a review.

The metabolism of oxygen in aerobic organisms leads to generation of reactive oxygen species (ROS). These entities are able to oxidize almost all classes of macromolecules, including proteins, lipids and nucleic acids. The physiological level of ROS is usually regulated by antioxidant defense mechanisms. There are at least three groups of antioxidant enzymes: superoxide dismutases, catalases and glutathione peroxidases (GSH-Pxs) which neutralize ROS. The trace elements (copper, zinc and selenium) bound to the active sites of the above listed enzymes play an important role in the antioxidant defense system. In mammals, a major function of selenium (Se) and Se-dependent GSH-Pxs is to protect cells from oxidative stress. Selenium concentrations and GSH-Px activities are altered in blood components of chronic kidney disease (CKD) patients. The Se level is frequently lower than in healthy subjects and the concentration very often decreases gradually with advancing stage of the disease. Studies on red cell GSH-Px activity in CKD patients reported its values significantly lower, significantly higher and lower or higher, but not significantly as compared with healthy subjects. On the other hand, all authors who studied plasma GSH-Px activity have shown significantly lower values than in healthy subjects. The degree of the reduction decreases gradually with the progression of the disease. High inverse correlations were seen between plasma GSH-Px activity and creatinine level. A gradual decrease in plasma GSH-Px activity in CKD patients is due to the fact that this enzyme is synthesized predominantly in the kidney and thus the impairment of this organ is the cause of the enzyme's lower activity. Se supplementation to CKD patients has a slightly positive effect in the incipient stage of the disease, but usually no effect was observed in end-stage CKD. Presently, kidney transplantation is the only treatment that may restore plasma Se level and GSH-Px activity in patients suffering from end-stage CKD. A few studies have shown that in kidney recipients, plasma Se concentration and GSH-Px activity are restored to normal values within a period of 2 weeks to 3 months following surgery and thus it can be acknowledged that Se supplementation to those patients has a positive effect on plasma GSH-Px activity.

Effect of atorvastatin on soluble CD14, CD40 Ligand, sE- and sP-selectins and MCP-1 in patients with type 2 diabetes mellitus: Relationship to cholesterol turnover

Metabolic abnormalities frequently associated with type 2 diabetes, feature besides endothelial dysfunction a novel factor of low cholesterol absorption and high cholesterol synthesis. We hypothesized an association between endothelial dysfunction and disturbances in cholesterol turnover, predisposing advanced atherosclerosis in patients with type 2 diabetes. We studied 75 patients: 30 with type 2 diabetes, 30 non-diabetic subjects with a history of cardiovascular disease, and 15 healthy subjects. Plasma sterols, soluble adhesion molecules sCD14, sCD40 Ligand, monocyte chemo-attractant protein-1 (MCP-1), sE- and sP-selectins were measured with and without atorvastatin therapy. The diabetic patients showed significantly higher levels of lathosterol and lower levels of sitosterol and campesterol. Non-diabetic subjects showed no significant differences in non-cholesterol based sterols. Plasma levels of hsCRP, sE- and sP-selectins and MCP-1 were significantly increased in patients with diabetes. The plasma levels of sCD40L correlate significantly with clinical parameters of BMI and glycaemia, and the plasma levels of sP-selectin correlate significantly with parameters of glycaemia and HbA 1c. The diabetic patients without statin therapy showed a significant correlation of sE-selectin with the marker of cholesterol absorption—sitosterol and sitosterol/cholesterol ratio. The diabetic patients without statin therapy showed a significant inverse correlation of sP-selectin with the marker of cholesterol synthesis—lathosterol. Both relationships disappeared with statin treatment. We conclude that endothelial dysfunction in obese patients with type 2 diabetes mellitus and cardiovascular disease associates with obesity and glycaemic control. The relation of parameters of endothelial dysfunction (such as sP-selectin and sE-selectin) with cholesterol synthesis and absorption may be influenced by reverse cholesterol transport.

Plasma glutathione peroxidase by ELISA and relationship to selenium level

Background Many assays have investigated GPx activity but there are few reports of immunoreactive methods of GPx plasma determinations and their relationship with plasma selenium. Methods A cross-sectional analysis of selenium and GPx was carried out on 170 adults randomly selected from the electoral role. Blood samples were collected and analysed for plasma GPx using a commercial enzyme-linked immunosorbent assay (ELISA) kit and plasma selenium using magnetic sector ICP–MS. Further investigations of GPx level were carried out using one-dimensional (1D) and two-dimensional (2D) polyacrylamide gel electrophoresis (PAGE). Results Plasma GPx was associated with plasma Se level ( r 2 = 0.24, P < 0.0001). Mean (range) Se was 108.9 (67.4–268.0) μg/l. Mean (range) plasma GPx was 18.5 (3.8–43.8) μg/ml, significantly higher than the theoretical mean GPx of around 6.5–6.9 μg/ml based on ICP–MS results and the proportion of Se in intact GPx. GPx was higher in males than females and lower in current than non-smokers and ex-smokers. PAGE analysis of glycine dissociated ELISA wells revealed GPx as well as a number of unknown proteins with significant variability between high and low GPx samples. Conclusions Plasma GPx is correlated with Se status, however, there is considerable GPx variability between patients and ELISA methods appear to significantly overestimate true plasma GPx.

The effect of selenium on thyroid status in a population with marginal selenium and iodine status

The effects of Se on thyroid metabolism in a New Zealand population are investigated, including (a) the relationship between Se and thyroid status, and (b) the effect of Se supplementation on thyroid status. The data used come from two cross-sectional studies of Se, I, thyroid hormones and thyroid volume (studies 1 and 4), and three Se intervention studies in which thyroid hormones, Se and glutathione peroxidase (GPx) activities were measured (studies 2, 3 and 5). There were no significant correlations between Se status and measures of thyroid status after controlling for sex at baseline or after supplementation in any of the studies. When data from study 4 were divided into two groups according to plasma Se, plasma thyroxine (T4) was lower in males with higher plasma Se levels (P=0.009). Se supplementation increased plasma Se and GPx activity, but produced only small changes in plasma T4 and triiodothyronine (T3):T4 ratio. In study 2, there was a significant reduction in plasma T4 (P=0.0045). In studies 3 and 5 there were small decreases in plasma T4 and a small increase in the T3:T4 ratio, which were not significantly different from placebo groups. Lack of significant associations between plasma Se and thyroid status, and only small changes in T4 suggest that Se status in New Zealand is close to adequate for the optimal function of deiodinases. Adequate plasma Se may be approximately 0.82-0.90 micromol/l, compared with 1.00-1.14 micromol/l for maximal GPx activities.

Optimization of selenium status by a single intraperitoneal injection of Se in Se-deficient rat: Possible application to burned patient treatment

In order to investigate the efficiency of a single selenium (Se) administration in restoring selenium status, Se and antioxidant enzymes were studied in an animal model of Se depletion. In Se-depleted animals receiving or not a single parenteral administration of Se, plasma, red blood cell (RBC), and tissue Se levels were measured concurrently with glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities. The oxidative stress was assessed by thiobarbituric acid-reactive species (TBARs), total thiol groups, glutathione, and tocopherol measurements. Our study showed that Se depletion with alterations in the antioxidant defense system (Se and GPx activity decreases) led to an increase of lipid peroxidation, a decrease of the plasma vitamin E level, and SOD activation. Sodium selenite injection resulted after 24 h in an optimal plasma Se level and a reactivation of GPx activity. In liver, brain, and kidney, Se levels in injected animals were higher than those in reference animals. However, this single administration of Se failed to decrease free radical damage induced by Se depletion. Therefore, in burned patients who exhibit an altered Se status despite a daily usually restricted Se supplementation, the early administration of a consistent Se amount to improve the GPx activity should be of great interest in preventing the impairment of the antioxidant status.

Alterations of antioxidant trace elements (Zn, Se, Cu) and related metallo-enzymes in plasma and tissues following burn injury in rats

To improve the nutritional support for burn patients, we evaluated the alterations of selenium, zinc and copper (Se, Zn and Cu) and their possible contributions to an unbalanced antioxidant response to burn injury. These trace elements and the related antioxidant enzymes, glutathione peroxidase (GPx) and superoxide dismutase (SOD), were studied both in plasma (or serum) and tissues of 20% total body surface area (TBSA) burned rats for 10 days. While plasma Se and serum Zn levels significantly decreased 6 h after burn injury, serum Cu levels increased after 1 day and remained elevated the following 9 days. Selenium levels increased in kidney but decreased progressively in liver. The hepatic Zn and Cu concentrations followed a biphasic increase following burn injury. During the first day, GPx activity decreased in plasma and remained unchanged in the organs, except for a moderate diminution in the liver. Liver Cu/Zn SOD activity increased from 6 h to 4 days. In summary, following burn injury, copper and zinc were redistributed to the liver and selenium to the kidney with non-detectable changes in the muscle and brain. Changes in antioxidant enzyme activities following burn injury were significant mainly in the plasma. Early combined antioxidant supplementation to maintain and restore antioxidant status in burn patients requires further study.

Dietary selenium supplementation of pigs and broilers as a way of producing selenium enriched meat

Serbia is a selenium (Se) deficient area. In the food chain animals accumulate Se in tissues, thus meat is a good source of this microelement. The aim of the research is to study the effects of different forms and doses of dietary Se in pigs and broilers on muscle and liver tissue Se concentrations, as well as to assess the possibility of using selenized meat as a Se source in the Belgrade area. Pigs (24) were randomly assigned in 4 groups: control and groups supplemented with Na-selenite: 0.10, 0.30 mgSe/kg feed and selenized yeast 0.30 mgSe/kg. Chicks (42) were assigned in 7 groups supplemented with 0.05, 0.10 and 0.30 mgSe/kg feed as Na-selenite or selenized yeast. Se content in muscle and liver samples was determined by AAS. Serum Se content in 54 healthy adult subjects (13 from Barajevo and 41 from inner city area) was determined by AAS. In all supplemented broilers Se-yeast was more effective in raising muscle Se content than Na-selenite. The most efficient increase in tissue Se content in pigs was obtained with 0.30 mg Se/kg feed supplemented as Se-yeast. Plasma Se levels in man were low, being significantly lower in subjects from Barajevo compared with the inner city residents (p<0.05). The use of Se-enriched pork and poultry meat in quantities according to dietary habits would have beneficial health effects specially in Se deficient rural areas where home grown feedstuffs are commonly used.

Essential Trace Elements Selenium, Zinc, Copper, and Iron Concentrations and Their Related Acute-Phase Proteins in Patients with Vivax Malaria

The aim of the present study is to evaluate the status of plasma essential trace elements selenium (Se), zinc (Zn), copper (Cu), and iron (Fe) concentrations and their related acute-phase proteins, ceruloplasmin (Cp), ferritin, transferrin (Tf), and albumin levels in patients with vivax malaria. Plasma Cu and Zn concentrations were determined by atomic absorption spectrometry (AAS). Se concentrations were determined by graphite furnace AAS. Fe, Cp, Tf, and albumin levels were determined by colorimetric methods. Plasma Se, Fe, and albumin levels were found to be significantly lower (p < 0.01, p < 0.001, and p < 0.05, respectively) and Cu, Cp, and ferritin levels and Cu/Zn ratios were significantly higher (p < 0.001, p < 0.001, p < 0.001, and p < 0.05, respectively) in patients when compared with those of healthy subjects. Plasma, Tf, and Zn levels were not found to be significantly different (p > 0.05) in patients and controls. There were positive important correlations between Cu and Cp (r = 0.908, p < 0.001), Zn and albumin (r = 0.633, p < 0.001), and negative correlations between Fe and ferritin content (r = -0.521, p < 0.05) and Fe and Tf (r = -0.616, p < 0.01) in the patients group. Our findings demonstrated that plasma essential trace elements Se, Cu, and Fe change, but these changes might be dependent on acute-phase proteins, which were regulated as a part of defense strategies of the organism, induced by hormonelike substances.

Micronutrients and cancer

Adverse dietary factors account for approximately 30% of all cancers. Overconsumption of energy is undoubtedly one of the major risk factors, but dietary composition is also very important. In particular, a low consumption of fruits and vegetables appears to double the risk of carcinomas of the lung and alimentary tract. Epidemiological studies suggest that high plasma levels of Se, carotenoids and ascorbic acid are protective against cancer. However, intervention studies with antioxidant nutrients have given mixed results, and it has not been established that the benefits of a high intake of fruits and vegetables are invariably related to the prevention of oxidative DNA damage. Folic acid supplementation appears to protect against colo-rectal neoplasia, probably by preventing mutations associated with the repair of uracil mis-incorporation. However, there are indications from animal studies that exposure to high levels of folic acid at certain stages of development may lead to epigenetic effects that are, as yet, poorly understood. There seems little doubt that micronutrients contribute to the protective effects of plant foods against cancers of the lung and alimentary tract, but it has not been established that these benefits can be achieved using supplements.