A micromethod for the determination of selenium in tissues and biological fluids by single-test-tube fluorimetry

Antioxidant Status in Patients after Breast Mastopexy and Augmentation

Background and Objectives: Mammary gland surgery has become very common, but there are complications of these operations, including the concept of breast implant illness (BII) in women with silicone gel breast implants (SBI), who suffer from various symptoms such as myalgia, arthralgia, fatigue, fever, dry eyes, or dry mouth. Silicone biomaterials are synthetic polymers that have their own physical and chemical properties and can exert their effect at the site of use and possibly on the general status of the body, causing inflammation and oxidative stress signs. The aim of the study was to examine components of the blood antioxidant system (AOS) of the mastopexy and breast augmentation patients before the operation, on the first post-op day, and 6 months after surgery. Materials and Methods: Healthy breast surgery patients (women aged 31 to 60 years without visible pathologies) were selected for the study and formed 2 groups: breast lift-mastopexy without silicone biomaterials (I group, 30 patients) and breast augmentation using silicone biomaterials (II group, 28 patients). All patients underwent standard preoperative tests. Glutathione peroxidase (GPxSe) and gamma-glutamyl transferase (GGT) in blood, selenium (Se), selenium protein P (SelPP), and total antioxidant status (TAS) in plasma were measured as AOS parameters. The concentration of vitamin D was also determined. A total of 174 blood tests were performed. Results: Overall, there were no differences in both groups in measured antioxidant system indicators over time; neither changes in objective nor subjective status were observed. However, baseline activity of GPxSe was relatively high but restored to normal values 6 months after surgery. In the mastopexy group, GPxSe decreased from 12,961.7 U/L by 18.9% to 10,513.4 U/L, and in the breast augmentation group, from 15,505.0 U/L by 25.1% to 11,265.5 U/L, which is a decrease of 18.9% and 25.1%, respectively. The patients did not note any complaints; other indicators of standard biochemical tests were within normal limits. Conclusions: The two types of surgical interventions, breast mastopexy and augmentation of the mammary glands, do not significantly impact blood AOS and are physiological in nature.

Effect of Selenium and Garlic Extract Treatments of Seed-Addressed Lettuce Plants on Biofortification Level, Seed Productivity and Mature Plant Yield and Quality

The enhancement of the plant seed yield and quality represents the basis of the successful productivity of the deriving crop. The effect of single and combined foliar treatments of lettuce plants with sodium selenate and garlic bulb extract on seed yield and quality and on mature plant biochemical characteristics was investigated using four lettuce cultivars (Bouquet, Picnic, Moskovsky parnikovy and Cavalier). The seed production of plants treated with Se increased by 20-41%, compared to the untreated control plants, while the augmentation was as much as 10-23% and 17-27% under garlic extract and the joint application of Se and garlic, respectively. Garlic extract stimulated the accumulation of Se in lettuce seeds, which rose by 1.21-1.29 times compared to the Se-treated plants. The proline levels in lettuce seeds exceeded the corresponding values recorded in the control ones by 1.32-1.64 times in the case of the Se supply, 1.10-1.47 times upon garlic extract application and 1.09-1.31 times under the combined Se/garlic treatment. All the treatments given to lettuce plants increased the leaf weight by 1.10-1.30 times, compared to the untreated control. The seed Se levels positively correlated with the leaf weight (r = 0.621; p < 0.005), chlorophyll (r = 0.672, p < 0.002) and total antioxidant activity (AOA; r = 0.730, p < 0.001) of plants grown from these seeds. Positive correlations were also recorded between the seed proline content and lettuce plant leaf weight, chlorophyll and AOA (r = 0.868, 0.811 and 0.815, respectively, at p < 0.001). Lettuce yield was positively correlated with the leaf AOA, chlorophyll and ascorbic acid content (r = 0.942, 0.921 and 0.665, respectively, at p < 0.001). The results indicate high prospects of Na2SeO4 and garlic extract application to seed-addressed lettuce plants, to improve seed productivity and quality, as well as lettuce yield and quality.

Effects of High Doses of Selenate, Selenite and Nano-Selenium on Biometrical Characteristics, Yield and Biofortification Levels of Vicia faba L. Cultivars

Faba bean (Vicia faba L.) has spread worldwide as an excellent source of proteins. To evaluate the efficiency of Se biofortification, four cultivars of V. faba (Belorussian, Russian Black, Hangdown Grünkernig, and Dreifach Weiβe) were foliar treated with 1.27 mM solutions of nano-Se, sodium selenate, and sodium selenite. Yield, protein, and Se contents were greatly affected by genetic factors and chemical form of Se. Selenium biofortification levels were negatively correlated with Se concentration in control plants and increased according to the following sequence: nano-Se < sodium selenite < sodium selenate. Contrary to selenate and selenite, nano-Se showed a growth-stimulating effect, improving yield, seed weight, and pod number. Pod thickness decreased significantly as a result of nano-Se supply and increased by 1.5-2.3 times under selenate and selenite supply. The highest Se concentrations were recorded in the seeds of Se-fortified cv. Belorussian and the lowest one in those of Se-treated Hangdown Grünkernig. Protein accumulation was varietal dependent and decreased upon 1.27 mM selenate and selenite treatment in the cvs. Hangdown Grünkernig and Dreifach Weiβe. The results indicate the high prospects of nano-Se supply for the production of faba bean seeds with high levels of Se.

Effects of Plant Biostimulation Time Span and Soil Electrical Conductivity on Greenhouse Tomato 'Miniplum' Yield and Quality in Diverse Crop Seasons

Biostimulants help plants cope with environmental stresses and improve vegetable yield and quality. This study was conducted to determine the protein hydrolysate (PH) effect of three different durations (weekly applications: three, six, or nine times plus an untreated control) in factorial combination with four soil electrical conductivities (EC: 1.5, 3.0, 4.5, or 6.0 mS·cm^-1) on yield, fruit quality, and elemental composition of tomato 'miniplum' grown in a greenhouse. Fruit yield was best affected, during the summer, by six and nine biostimulant applications at EC 3.0 mS·cm^-1, and in the same season, the six treatments led to the highest fruit number with no difference compared to nine applications; during the winter, the three and six treatments improved the mentioned variables at each EC level. Fruits' dry residue and Brix^o were positively affected by biostimulation both in summer and winter. In summer, the 6.0 mS·cm^-1 EC led to the highest dry residue and Brix^o values, though the latter did not show any significant difference compared to 4.5 mS·cm^-1; in winter, the best results corresponded to 4.5 and 6.0 mS·cm^-1. A higher beneficial effect of PH on fruit antioxidant status, i.e., lycopene, polyphenols, ascorbic acid levels, and lipophilic (LAA) and hydrophilic (HAA) activity, was recorded in winter compared with summer. Positive correlations between polyphenols and LAA, as well as ascorbic acid content and HAA were found for all EC and PH treatments. Most of the mineral elements tested demonstrated concentration stability, whereas the highest EC decreased P, Mg, Cu, and Se accumulation. The opposite effect was shown by PH application on Se and Mn levels, with P tending to increase. The concentrations of Fe, Zn, and Cu were the lowest under the longest duration of PH supply. These results further confirm the essential role of plant biostimulation in enhancing tomato yield and quality, with a particular focus on the treatment duration.

Effect of Sodium Selenate and Selenocystine on Savoy Cabbage Yield, Morphological and Biochemical Characteristics under Chlorella Supply

Biofortification of Brassica oleracea with selenium (Se) is highly valuable both for human Se status optimization and functional food production with direct anti-carcinogenic activity. To assess the effects of organic and inorganic Se supply for biofortifying Brassica representatives, foliar applications of sodium selenate and selenocystine (SeCys2) were performed on Savoy cabbage treated with the growth stimulator microalgae Chlorella. Compared to sodium selenate, SeCys2 exerted a stronger growth stimulation of heads (1.3 against 1.14 times) and an increase of leaf concentration of chlorophyll (1.56 against 1.2 times) and ascorbic acid (1.37 against 1.27 times). Head density was reduced by 1.22 times by foliar application of sodium selenate and by 1.58 times by SeCys2. Despite the greater growth stimulation effect of SeCys2, its application resulted in lower biofortification levels (2.9 times) compared to sodium selenate (11.6 times). Se concentration decreased according to the following sequence: leaves > roots > head. The antioxidant activity (AOA) was higher in water extracts compared to the ethanol ones in the heads, but the opposite trend was recorded in the leaves. Chlorella supply significantly increased the efficiency of biofortification with sodium selenate (by 1.57 times) but had no effect in the case of SeCys2 application. Positive correlations were found between leaf and head weight (r = 0.621); head weight and Se content under selenate supply (r = 0.897-0.954); leaf ascorbic acid and total yield (r = 0.559), and chlorophyll (r = +0.83-0.89). Significant varietal differences were recorded for all the parameters examined. The broad comparison performed between the effects of selenate and SeCys2 showed significant genetic differences as well as important peculiarities connected with the Se chemical form and its complex interaction with Chlorella treatment.

Effect of Foliar Sodium Selenate and Nano Selenium Supply on Biochemical Characteristics, Essential Oil Accumulation and Mineral Composition of Artemisia annua L

Selenium (Se) biofortification of aromatic plants is a promising strategy to produce valuable functional food with high biological activity and enhanced essential oil yield. The experiment carried out in 2021 and 2022 on A. annua treated with sodium selenate or nano-Se sprayed on foliar apparatus demonstrated a significant increase in photosynthetic pigments, pectin, waxes, macro- and microelements and a decrease in malonic dialdehyde (MDA) accumulation. Contrary to literature reports, neither selenate nor nano-Se showed a beneficial effect on essential oil accumulation; the oil yield did not differ between the selenate treated and control plants but was halved by the nano-Se application. Extremely high variations in the number of essential oil components, as well as in the eucalyptol, artemisia ketone, camphor and germacrene D ratio in the 2021 and 2022 experiments were recorded. The analysis of the 2016-2022 data for oil yield and composition in the control plants revealed a direct correlation between the number of components and of solar flares, and a negative correlation between oil yield and the percentage of spotless days. Both control plants and plants fortified with selenium showed higher levels of germacrene D and lower levels of artemisia ketone in 2022, characterized by more remarkable solar activity compared to 2021. Nano-Se supply resulted in the highest percentage of germacrene D accumulation. The results of the present research highlight the importance of the solar activity effect on the essential oil yield and quality of aromatic plants.

Joint Cultivation of Allium ursinum and Armoracia rusticana under Foliar Sodium Selenate Supply

Despite the high value of ramson (Allium ursinum) in medicine and nutrition, it is not cultivated in open fields due to the need for shading as well as weeding during the early crop stages. Research was carried out in an open field with the aim to improve A. ursinum growth, through its intercropping with Armoracia rusticana (horseradish). In the latter context, with and without sodium selenate application, ramson and horseradish showed reciprocal growth stimulation, as ramson biomass increased by 1.28 times and horseradish root biomass by 1.7 times. The biofortification level of horseradish roots increased from 5.9 to 9.6 times due to joint plant growth under selenium (Se) supply. The opposite phenomenon was recorded for ramson leaves, as the biofortification level decreased from 11.7 in the case of Se supplementation to 6.7 in plants supplied with sodium selenate when jointly cultivated with horseradish. Among the tested antioxidants, the highest increase due to joint cultivation and/or Se supply was recorded for ascorbic acid by 1.69 times in ramson leaves and 1.48 and 1.37 times in horseradish roots and leaves, respectively. All treatments significantly increased the total antioxidant activity (AOA) of horseradish leaves (by 1.33-1.49 times) but not roots. Comparison of the results obtained in field conditions with those obtained earlier for the Se biofortification of ramson in the natural habitat (forest) revealed significantly higher levels of the plant's antioxidant status under environmental stress (field) and a decrease in the correspondent differences as a consequence of Se biofortification. The estimation of allelopathic beneficial interaction between ramson and horseradish implies the efficiency of ramson growth and production of functional food with high levels of Se (Se-ramson leaves and Se-horseradish roots).

Evaluation of Factors Affecting Tree and Shrub Bark's Antioxidant Status

The importance of using the barks of trees and shrubs as powerful natural antioxidants suggests the necessity to evaluate the effect of different environmental factors on bark extracts’ quality. The determination of total antioxidant activity (AOA) and polyphenol content (TP) in the bark of 58 tree and shrub species from 7 regions differing in mean annual temperature, insolation, humidity, salinity level, and altitude was performed. The above stress factors positively affected bark AOA but did not have a statistically significant effect on TP. The bark of trees grown in the seashore proximity was characterized by significantly higher AOA than samples gathered in other areas, similarly to the trees grown at high altitude. The bark antioxidant status of 18 species was described for the first time. New sources of powerful antioxidants were represented by the ornamental shrubs Cornus sanguinea and Cornus alba, which showed the highest AOA (169−171 mg GAE g−1 d.w.). Among the typical halophytes, Calligonum and Tamarix had high AOA (172 and 85 mg GAE g−1 d.w.), while in the bark of tamarisk, an Se accumulator, an Se concentration of about 900 µg kg−1 d.w. was recorded. A significant positive correlation was found between leaves and bark AOA in the Karadag Nature Reserve’s deciduous trees (r = 0.898, p < 0.01). The relationship between bark AOA and TP was highly significant (r = 0.809; p < 0.001) for all samples except the mountainous ones. The results of the present research revealed new opportunities in successive bark utilization.

Iodine and Selenium Biofortification of Chervil Plants Treated with Silicon Nanoparticles

Production of functional food with high levels of selenium (Se) and iodine (I) obtained via plant biofortification shows significant difficulties due to the complex interaction between the two elements. Taking into account the known beneficial effect of silicon (Si) on plant growth and development, single and joint foliar biofortification of chervil plants with potassium iodide (150 mg L-1) and sodium selenate (10 mg L-1) was carried out in a pot experiment with and without Si nanoparticles foliar supplementation. Compared to control plants, nano-Si (14 mg L-1) increased shoot biomass in all treatments: by 4.8 times with Si; by 2.8 times with I + Si; by 5.6 times with Se + Si; by 4.0 times with I + Se + Si. The correspondent increases in root biomass were 4.5, 8.7, 13.3 and 10.0 times, respectively. The growth stimulation effect of Se, I and I + Se treatments resulted in a 2.7, 3.5 and 3.6 times increase for chervil shoots and 1.6, 3.1 and 8.6 times for roots, respectively. Nano-Si improved I biofortification levels by twice, while I and Se enhanced the plant content of each other. All treatments decreased nitrate levels, compared to control, and increased the photopigment accumulation. Improvement of total antioxidant activity and phenolic content was recorded only under the joint application of Se + I + Si. Foliar nano-Si treatment affected other element content in plants: decreased Na+ accumulation in single and joint supplementation with Se and I, restored Fe, Mn and Cr amount compared to the decreased levels recorded in separately Se and I fortified plants and promoted Al accumulation both with or without Se and I biofortification. The results of this research suggest high prospects of foliar nano-Si supply for enhancing both growth and joint I/Se biofortification of chervil.

Plasma levels of Th17-associated cytokines and selenium status in autoimmune thyroid diseases

Introduction

The contribution of Th17 cytokines to autoimmune thyroid disease (AITD) is generally accepted. However, the roles of Th17 cells in the initiation and progression of Hashimoto's thyroiditis (HT) and Graves' disease (GD) remain unclear. Selenium deficiency, along with genetic predisposition and environmental factors, may have a role in thyroid autoimmunity.

Aim

We aimed to assess (1) the Th17 immune response by measuring plasma levels of Th17‐ and Treg‐associated cytokines and (2) the selenium status in treatment‐naïve Latvian patients with newly diagnosed GD or HT.

Methods

Eleven GD patients, 41 HT patients, and 26 healthy subjects were recruited for this study. Plasma levels of IL‐17a, IL‐22, IL‐23, IL‐6, and IL‐10 were detected by xMAP technology, while selenium was detected fluorometrically.

Results and Conclusions

No significant differences in IL‐17a, IL‐22, IL‐23, IL‐6, or IL‐10 levels were found among the HT patients, GD patients, and controls. In the HT patients, IL‐17a levels were positively correlated with IL‐22, IL‐23, IL‐6, and IL‐10, while IL‐22 was correlated with IL‐6, IL‐23, and IL‐10. In the GD patients, IL‐17a levels were positively correlated with IL‐22, IL‐23, and IL‐10; IL‐22 was positively correlated with IL‐23, IL‐6, and IL‐10; FT3 was positively correlated with IL‐17a, IL‐23, and IL‐10; and FT4 was positively correlated with IL‐17a and IL‐10 levels. Plasma selenium levels were negatively correlated with antithyroid peroxidase antibody titers in the HT patients. Although no difference in selenium levels was observed between the AITD patients and controls, the selenium status of the Latvian patients with GD or HT was at a suboptimal level.

Joint Selenium-Iodine Supply and Arbuscular Mycorrhizal Fungi Inoculation Affect Yield and Quality of Chickpea Seeds and Residual Biomass

The essentiality of selenium (Se) and iodine (I) for the human organism and the relationship between these two trace elements in mammal metabolism highlight the importance of the joint Se–I biofortification to vegetable crops in the frame of sustainable farming management. A research study was carried out in southern Italy to determine the effects of the combined inoculation with arbuscular mycorrhizal fungi (AMF) and biofortification with Se and I on plant growth, seed yield, quality, and antioxidant and elemental status, as well as residual biomass chemical composition of chickpea grown in two different planting times (14 January and 28 February). The AMF application improved the intensity of I and Se accumulation both in single and joint supply of these elements, resulting in higher seed yield and number as well as dry weight, and was also beneficial for increasing the content of antioxidants, protein, and macro- and microelements. Earlier planting time resulted in higher values of seed yield, as well as Se, I, N, P, Ca, protein, and antioxidant levels. Se and I showed a synergistic effect, stimulating the accumulation of each other in chickpea seeds. The AMF inoculation elicited a higher protein and cellulose synthesis, as well as glucose production in the residual biomass, compared to the single iodine application and the untreated control. From the present research, it can be inferred that the plant biostimulation through the soil inoculation with AMF and the biofortification with Se and I, applied singly or jointly, proved to be effective sustainable farming tools for improving the chickpea seed yield and/or quality, as well as the residual biomass chemical composition for energy production or beneficial metabolite extraction.

Yield, Growth, Quality, Biochemical Characteristics and Elemental Composition of Plant Parts of Celery Leafy, Stalk and Root Types Grown in the Northern Hemisphere

Celery is one of the major nutraceutical vegetable species due to the high dietary and medicinal properties of all of its plant parts. Yield, growth and produce quality of six celery genotypes belonging to leafy (Elixir and Samurai), stalk (Atlant and Primus) or root (Egor and Dobrynya) types, as well as the distribution of biomass, sugars, mineral elements and antioxidants among the different plant parts, were assessed. Within the celery root type, cultivar Dobrynya resulted in higher yield than Egor, whereas the genotype did not significantly affect the marketable plant part production of leafy and stalk types. Leaf/petiole ratios relevant to biomass, total dissolved solids, sugars, ascorbic acid, flavonoids, antioxidant activity and ash, K, Zn, Fe, Mn, Cu and Se content were significantly affected by the celery type examined. Ash content was highest in the leaves and lowest in the roots. Celery antioxidant system was characterized by highly significant relationships between ascorbic acid, polyphenols, flavonoids, antioxidant activity and Zn. Among the celery types analyzed, the highest values of chlorophyll, Fe and Mn content as well as antioxidant activity were recorded in leaves from root genotypes, which suggests interesting nutraceutical prospects of the aforementioned plant parts for human utilization.

Effects of Arbuscular Mycorrhizal Fungi on Yield, Biochemical Characteristics, and Elemental Composition of Garlic and Onion under Selenium Supply

Biofortification of garlic and onion plants with selenium and arbuscular mycorrhizal fungi inoculation are considered beneficial for producing functional food with anticarcinogenic properties. The effects of arbuscular mycorrhizal fungi (AMF) inoculation, sodium selenate foliar application, and the combination AMF + selenium (Se), compared to an untreated control, were assessed regarding the bulb yield, biochemical characteristics, and mineral composition. AMF + Se application resulted in the highest yield, monosaccharides, and Se content in both garlic and onion bulbs; and an increase of ascorbic acid and flavonoids in onion, and flavonoids in garlic. The highest bulb concentrations of P and K were recorded under the AMF + Se application, Ca was best affected by AMF, and Mg accumulation was highest under all the treatments in garlic and upon AMF + Se application in onion bulbs. Contrary to garlic, onion bulbs were characterized by a remarkable increase in microelements (B, Cu, Fe, Mn, Si, Zn) under the AMF + Se treatment. Selenium, either with or without AMF application, promoted the accumulation of B and Si in onion and Mo and Zn in garlic bulbs. It can be inferred that the interaction between AMF and Se is highly specific, differing for garlic and onion grown in similar environmental conditions in Grozny region, Chechen Republic.

Yield, Antioxidant Components, Oil Content, and Composition of Onion Seeds Are Influenced by Planting Time and Density

Research was carried out on onion landrace (Ramata di Montoro) for seed production in southern Italy, with the aim to evaluate the effects on yield and quality of four bulb planting times in factorial combination with four densities, using a split plot design with three replicates. The number of flower stalks per plant, their height and diameter, and the inflorescence diameter decreased with the bulb planting delay and density increase. The highest plant leaf area and LAI (leaf area index), seed yield, number, and mean weight were recorded with the earliest planting time, with the lowest bulb density eliciting the highest plant leaf area but the lowest LAI and seed yield per hectare. The ratio between seeds and inflorescence weight, and seed germinability, decreased with the planting delay and density increase. Seed oil, protein, and antioxidant content (polyphenols and selenium) were highest with the last crop cycle. The polyunsaturated fatty acids, predominant in oil, increased with planting time delay, whereas the monounsaturated fatty acids decreased. Linoleic, oleic, and palmitic acid prevailed among polyunsaturated, monounsaturated, and saturated fatty acids, respectively. Planting from 20 December to 10 January with 3.3 cold-stored bulbs per m² was the most effective combination in terms of seed yield per hectare, whereas seed oil content and quality were the best, with the last crop cycle starting on 21 February, independent of bulb density.

Effect of Selenium Biofortification and Beneficial Microorganism Inoculation on Yield, Quality and Antioxidant Properties of Shallot Bulbs

Plant biofortification with selenium in interaction with the application of an arbuscular mycorrhizal fungi (AMF)-based formulate, with the goal of enhancing Se bioavailability, is beneficial for the development of the environmentally friendly production of functional food with a high content of this microelement. Research was carried out in order to assess the effects of an AMF-based formulate and a non-inoculated control in factorial combination with two selenium treatments with an organic (selenocystine) or inorganic form (sodium selenate) and a non-treated control on the yield, quality, antioxidant properties, and elemental composition of shallot (Allium cepa L. Aggregatum group). Selenocystine showed the best effect on the growth and yield of mycorrhized plants, whereas sodium selenate was the most effective on the non-inoculated plants. The soluble solids, total sugars, monosaccharides, titratable acidity, and proteins attained higher values upon AMF inoculation. Sodium selenate resulted in higher soluble solids, total sugars and monosaccharide content, and titratable acidity than the non-treated control, and it also resulted in higher monosaccharides when compared to selenocystine; the latter showed higher protein content than the control. Calcium, Na, S, and Cl bulb concentrations were higher in the plants inoculated with the beneficial microorganisms. Calcium and sodium concentrations were higher in the bulbs of plants treated with both the selenium forms than in the control. Selenocystine-treated plants showed enhanced accumulation of sulfur and chlorine compared to the untreated plants. The AMF inoculation increased the bulb selenium content by 530%, and the Se biofortification with selenocystine and sodium selenate increased this value by 36% and 21%, respectively, compared to control plants. The AMF-based formulate led to increases in ascorbic acid and antioxidant activity when compared to the non-inoculated control. The bulb ascorbic acid was increased by fortification with both selenium forms when compared to the non-treated control. The results of our investigation showed that both AMF and selenium application represent environmentally friendly strategies to enhance the overall yield and quality performances of shallot bulbs, as well as their selenium content.

Antioxidant effects of Camellia sinensis L. extract in patients with type 2 diabetes

The prevalence of diabetes mellitus (DM) has dramatically increased in the past decade. Furthermore, increasing evidence from research shows that oxidative stress (OS) plays a crucial role in the pathogenesis of diabetes and in its complications. A search for ways to reduce oxidative damage has become the focus of interest for the majority of scientists. In this study, we determined the radical scavenging activity of single green tea constituents by using an on-line high performance liquid chromatography (HPLC)-2,2-diphenyl-1-picrylhydrazyl (DPPH) method and evaluated the antioxidant effects on type 2 diabetic patients by performing a double-blind, placebo-controlled study. Epigallocatechin gallate was identified as the most potent antioxidant, contributing approximately 50% of the total antioxidant capacity of green tea extract. We also found a statistically significant decrement of lipid peroxidation markers in patients treated with green tea extract after 9 months or after 18 months of follow-up. Overall, these findings are attractive for diabetic patients, helping them to keep a high level of performance and well-being, which ultimately may delay the time of disability and reduce mortality.

Advances of selenium supplementation in posttraumatic stress disorder risk group patients

Posttraumatic stress disorder (PTSD) is a complex of symptoms developed in a patient after traumatic event. The basis of PTSD pathophysiology is hyper activation of neurones under stress factors influence, so-called excitotoxicity, followed by oxidative stress (OS) because of an accumulation of free radicals. Lipid peroxidation can lead to neurons damage. Neurons are especially susceptible to OS, changing signal transduction and information processing mechanisms. Clinically excitotoxicity preforms as different acute and/or chronic stress reactions and can cause PTSD. Selenium (Se) is involved on different stages of transport and metabolism of Glutamate. Research aim: to access PTSD incidence, OS parameters and their adjustment advances using organic Se in PTSD risk group patients. PTSD symptomatic severity (in PCL-M points) reduced for 5.85% to baseline, Prevalence Rate reduced for 46.03% to baseline in Se group patients. We can conclude that: 1) there is a statistically reliable correlations between the incidence of PTSD and OS parameters, between PTSD symptomatic severity and OS parameters; 2) the use of Se during the mission can reduce the OS parameters, minimize the incidence of PTSD and reduce the PTSD symptomatic severity.

Selenium and oxidative stress in cancer patients

In order to identify the features of violations of free-radical processes in blood serum of 94 untreated cancer patients with different localization of the tumor (cancer of the stomach, colon, breast, ovarian, hemoblastoses) were determined selenium levels and indicators of oxidative stress (sum of metabolites of nitrogen - NOx, the level of superoxide dismutase - Cu/ZnSOD and malondiialdehyde-MDA, and the activity of catalase). In addition, 40 patients with malignant liver disease and clinical signs of liver failure in the early postoperative period was carried out a comparative evaluation of the efficacy of selenium-containing drug 'Selenaze' (sodium selenite pentahydrate). It was found that selenium levels in cancer patients by 25-30% below the norm of 110-120 mg/l at a rate of 73.0±2.6 mg/l. Low levels of NOx was detected in patients with all tumor localizations (22.1±1.1 mM, with normal range 28.4±0.9 mM). The exceptions were patients with extensive malignant process in the liver, in which the NOx levels were significantly higher than normal (p<0.001). The high level of NOx has a toxic effect on the hepatocyte, causing metabolic disorders and inflammatory-necrotic changes in the liver. Elevated levels of SOD and MDA in normal values of catalase activity was detected in all patients. The use of 'Selenaze' in postoperative patients with tumors of the liver increased selenium levels by 10-12%, which was accompanied by a decrease in the content of SOD and NOx, and contributed to earlier recovery of detoxic and synthetic liver function. These findings point to an intensification of oxidative stress and metabolic disorders in the malignant process, which is the basis for metabolic correction.

Comparative evaluation of selenium accumulation by allium species after foliar application of selenium nanoparticles, sodium selenite and sodium selenate

Accumulation and translocation intensity of selenium nanoparticles by natural selenium accumulators-perennial onions-is established and a decrease of these parameters is demonstrated in a sequence: Se(+6) > Se(0) > Se(+4).

Selenium distribution in eggs of avian species

We studied the effect of egg mass of eight different avian species on Se distribution between egg components and the effect of incubation on Se accumulation by chicken eggshell and shell membrane. Eight groups of birds received a diet without Se supplementation. Unfertile eggs were collected after 35 days of feeding; yolk, albumen, shell and shell membrane were assayed separately for Se. All avian species studied showed identical Se concentration in yolk-albumen complex equal to 38.7 microg Se/100 g, reflecting a linear correlation between yolk-albumen mass and Se content. Shells and shell membrane Se accumulation showed quadratic correlation with the appropriate mass thus explaining unusually high Se concentration in ostrich shell and shell membrane, that reached values 1785 and 1904 microg Se/kg respectively. Incubation of fertile eggs decreased eggshell Se content, the effect being more expressed in eggs from hens fed sodium selenite compared to organic Se utilization (Sel-Plex). It was concluded that shell might be an additional Se source for an embryo.

Monitoring of feeds selenium status in a southeast region of Romania

One hundred and eighty-five samples of feeds (hays, green plants, and concentrate feed) from households covering 41 localities in Dobrudja, a southeast region of Romania, were collected and analyzed for selenium (Se) content by spectrofluorometry with 2,3-diaminonaphthalene. Only 6.5% of the samples analyzed were, in terms of the feed Se content, considered appropriate (i.e., 0.15-0.30 ppm), within the normal range. The remaining 93.5% proved to be Se deficient; the results fell into the 0.001-0.150 ppm range. Consequently, the samples were divided into three deficiency groups based on the content recorded as follows: severe for 3.2% (Se below 0.01 ppm), critical for 84.9% (Se in the 0.01-0.1 ppm range), and marginal for 5.4% (Se in the 0.1-0.15 ppm range). Conclusively, the Dobrudja feeds may be said to be generally Se deficient, which requires prophylactic and therapeutic measures to correct animal selenium deficiency.

The influence of supplements of selenite, selenate and selenium yeast on the selenium status of dairy heifers

The aim of the study was to define possible differences between selenite, selenate and selenium yeast on various aspects of selenium status in growing cattle. Twenty-four Swedish Red and White dairy heifers were fed no supplementary selenium for 6 months. The basic diet contained 0.026 mg selenium/kg feed dry matter (DM). After the depletion period the animals were divided into 4 groups; group I-III received 2 mg additional selenium daily as sodium selenite, sodium selenate, and a selenium yeast product, respectively. Group IV, the control group, received no additional selenium. The total dietary selenium content for groups I-III during the supplementation period was 0.25 mg/kg DM. After the depletion period the mean concentration of selenium in blood (640 nmol/l) and plasma (299 nmol/l) and the activity of GSH-Px in erythrocytes (610 mukat/l) were marginal, but after 3 months of supplementation they were adequate in all 3 groups. The concentration of selenium in blood and plasma was significantly higher in group III than in groups I and II, but there was no significant difference between groups I and II. The activity of GSH-Px in erythrocytes did not differ between any of the supplemented groups. The animals in the control group had significantly lower concentrations of selenium in blood and plasma and lower activities of GSH-Px in erythrocytes than those in the supplemented groups. The activity of GSH-Px in platelets was also increased by the increased selenium intake. There was no difference in the concentration of triiodothyronine (T3) between any of the groups, but the concentration of thyroxine (T4) was significantly higher in the unsupplemented control group.

The human selenium status in 27 regions of Russia

Russia is the largest nation in the world and it has vastly different climatic and geochemical conditions. The human selenium status is determined mainly by the selenium intake from foods, whose concentration is subject to geochemical, geological and temporal factors. The data on the selenium status of populations in Russia are scarce and sporadic. This review presents the most recent selenium data acquired using adequate quality assurance measures. Serum samples were obtained from 2462 healthy blood donors between 1990-1996 from 125 locations representing 27 different regions of Russia. Samples of wheat flour and dried milk were also analyzed from most regions. The mean serum selenium concentration per region varied from 0.80 mumol/l in the western regions (Pskov) to 1.84 mumol/l in the easternmost regions (Sakhalin). A low (0.76-1.00 mumol/l) serum selenium concentration was found in only 6% of the locations. In 88% of the locations the mean serum selenium concentrations were moderate (1.01-1.40 mumol/l) and the highest values, > 1.45 mumol/l were found in eight towns. Wheat flour selenium concentrations varied widely from 44 to 557 micrograms/kg depending on the origin. The low values were either domestic or European and the high values of American or Australian origin. A high correlation between serum selenium and wheat flour (r = 0.79) suggests that the selenium status in most instances is determined by high selenium in wheat. Overtly very low or high serum selenium levels were not found in the 27 regions studied in Russia.

Selenium content of milk and milk products of Turkey. II

Selenium content of 1028 milk and milk products of Turkey are presented in this study. The selenium content of human milk (colostrum, transitional, and mature milk), various kinds of milk [cow, sheep, goat, buffalo, paper boxes (3%, 1.5%, 0.012% fat), bottled milk, condensed milk (10% fat), mineral added milk (1.6%), and banana, strawberry, and chocolate milk] and milk products (kefir, yogurt, Ayran, various cheese, coffee cream, ice cream, butter, margarine, milk powder, and fruit yogurt) in Turkey were determined by a spectrofluorometric method. The selenium levels of cow milks collected from 57 cities in Turkey were also determined. Selenium levels in cow milk varied with geographical location in Turkey and were found to be lowest for Van and highest for Aksaray. The results [milk (cow, sheep, goat, buffalo and human) and milks products] were compared with literature data from different countries.

Selenite and selenium yeast as feed supplements to growing fattening pigs

Twenty-four cross-bred fattening pigs weighing, on average, 24 kg were divided into three equal groups and fed a basic diet containing 0.1 mg selenium/kg. The diet of group A was supplemented with 0.3 mg selenium/kg derived from selenium yeast, group B with 0.1 mg selenium/kg from the same source, and group C with 0.3 mg/kg from sodium selenite. The pigs were slaughtered after 103 days. There was no significant difference between the mean whole blood selenium concentration of the pigs supplemented with selenium yeast neither after five nor after nine weeks of supplementation (group A, 201 and 213 micrograms/litre; group B 192 and 201 micrograms/litre, respectively), but the group supplemented with selenite had significantly lower concentrations both after five and nine weeks (158 and 159 micrograms/litre, respectively). There were no significant differences between the mean activity of glutathione peroxidase (GSH-Px; in the whole blood of the three groups (group A, 348 and 327 mukat*/litre, group B, 342 and 302 mukat/litre; group C, 332 and 300 mukat/litre, after five and nine weeks, respectively). The concentration of selenium in the liver of the pigs supplemented with organic selenium was significantly higher than in the pigs supplemented with selenite (group A, 0.54 mg/kg wet weight; group B, 0.54 mg/kg; group C, 0.40 mg/kg). No deposits of lipofuscin or ceroid pigments were observed in the histological preparations of liver and heart from any of the pigs.

Selenite and selenium yeast as feed supplements for dairy cows

The availability of inorganic and organic forms of selenium to dairy cows was studied by giving 25 cows supplementary selenium for 9 months either as sodium selenite or as a selenium-containing yeast product. Group I (eight cows) received 3.0 mg selenium as sodium selenite daily, group II (nine cows) received 3.0 mg selenium as the selenium yeast product, and group III (eight cows) received 0.75 mg selenium as the selenium yeast product. The total selenium contents of the ration were 0.26-0.32 mg/kg feed dry matter for groups I and II, and 0.16-0.18 mg/kg for group III. The supplement of 0.75 mg selenium daily from the yeast product maintained the selenium concentrations of whole blood and milk at the same levels as 3.0 mg selenium as sodium selenite, and 3.0 mg selenium from the yeast product increased the selenium concentration of whole blood by approximately equal to 40% and that of milk by approximately equal to 100%. The activity of glutathione peroxidase in erythrocytes of the group given selenite was not significantly different from that in either of the groups given the yeast product. The concentrations of selenium in the tissues of two cows from each group were marginal to adequate, and there was a trend for the concentrations to be higher in the tissues of the cows supplemented with the yeast product.

Reproducibility and validity of a food frequency questionnaire in a case-control study on breast cancer

A 110-item food frequency questionnaire was tested among 152 community controls of the Kuopio Breast Cancer Study. They completed the questionnaire twice and kept two 7-day diet records at 3-month intervals. The intraclass correlations for nutrients varied from 0.49 (thiamine with supplements) to 0.81 (lactose), and for foods from 0.52 (poultry) to 0.84 (alcoholic drinks). The Pearson correlations between the first food frequency questionnaire and the 14-day diet records, after adjustment for energy, varied for nutrients from 0.18 (thiamine without supplements) to 0.80 (alcohol), and for foods from 0.30 (inner organs) to 0.90 (coffee). Comparison of quintile classification between the two methods is reasonably accurate when observed restrictions concerning some nutrients and foods are taken into account. A low association (r = 0.12) was observed between toenail selenium and dietary selenium intake, indicating the difficulty of estimating selenium intake in the Finnish diet.

Environmental effects of nationwide selenium fertilization in Finland

To study the possible pollution of natural waters by selenium added to agricultural fertilizers, water selenium concentrations were determined in lakes and ground water pools during the year 1992, when the enrichment of fertilizers by selenium had continued for 8 yr. Water samples were preconcentrated by evaporating, and selenium concentrations were analyzed fluorometrically using the dye 2,3-diaminonaphthalene after wet digestion. In lake water samples from 13 lakes, no significant correlations were found between selenium and pH, chlorophyll A, total nitrogen, or phosphorus. Agriculturally affected and nonaffected lakes had no differences in their selenium concentrations. In the lakes that were surrounded by cultivated fields mean water selenium was 83.4 ng/L (range: 75.2-93.4 ng/L, n = 9). Correspondingly, in lakes situated in forests without agricultural surroundings, mean water selenium concentration was 76.5 ng/L (range: 51.2-110 ng/L, n = 3). Only one lake in the close vicinity of a coal power plant had a high water selenium concentration (mean 272 ng/L). In ground water samples, there was a big variation in selenium levels between different pools, the levels varying between 33 and 260 ng/L. This variation may partly be explained by different selenium concentrations of the bedrock and sediments. However, simultaneous increase of total nitrogen, phosphorus, and selenium levels in consecutive samples from some ground water pools indicates leaching of selenium from the fertilizers into the ground water in certain areas.

Factors affecting the selenium intake of people in Transbaikalian Russia

The selenium concentration in foods grown and consumed and in plasma, red blood cells, and toenails of people living in the district of Chita in the transbaikalian part of Russia were studied in August 1991. Preliminary results from the area have suggested low selenium intakes and the possible occurrence of cardiomyopathy (Keshan disease) in the population. A low selenium concentration in foods grown locally was found: mean selenium concentration in wheat grains was 1, 5, and 28 micrograms/kg, respectively, in three villages studied, that of oats was between 3-6 micrograms/kg, and of cow's milk 10-27 micrograms/kg dry matter. The selenium concentration of bread was considerably higher, between 87-337 micrograms/kg dry wt, presumably because wheat imported from the US had been used for baking. Occasional samples of pork, beef, and mutton contained between 32-218 micrograms selenium/kg dry wt. Low selenium concentrations were observed in samples of soil and river water. The mean plasma selenium concentration of 52 persons was 1.02 mumol/L, including 33 children and 19 adult subjects. The selenium concentrations in red blood cells and toenails were 1.95 mumol/L and 0.61 mg/kg, respectively. No symptoms of heart disease caused by selenium deficiency were observed. It is concluded that the selenium status of people was fairly good thanks to the contribution to dietary intake of imported wheat with a high selenium content. As the selenium concentration was very low in foods grown in the area, the selenium intake of the population will be reduced to a very low level if only locally produced foods are consumed.

Role of selenium-dependent glutathione peroxidase in protecting against t-butyl hydroperoxide-induced damage in hepatocytes

The role of the selenoenzyme glutathione peroxidase (Se-GSHPx) in protecting against oxidative injury was studied in hepatocytes isolated from rats fed either a low-selenium (Se-) or a selenium-adequate (Se+, control) diet. In rats fed Se- diet for eight weeks the selenium content of plasma and liver was lowered to 15 and 8%, respectively. No Se-GSHPx and only 5% of total GSHPx activity was detected in Se- hepatocytes. However, the Se- hepatocytes were as resistant as the Se+ cells to oxidative injury by 0.8 mM tert-butyl hydroperoxide (t-BuOOH), or 0.2 mM t-BuOOH plus 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), an inhibitor of oxidized glutathione (GSSG) reductase. Only at 1.5 mM t-BuOOH or at 0.5 mM t-BuOOH with BCNU were cell damage and lipid peroxidation more evident in Se- cells. At all t-BuOOH concentrations used the depletion of cellular glutathione (GSH) was similar in magnitude in Se- and Se+ cells, but Se+ cells released more glutathione (mainly GSSG), obviously due to their higher Se-GSHPx activity. These results suggest that hepatocytes devoid of Se-GSHPx activity maintain a high capacity to resist peroxidative attack, either via residual (non-Se)GSHPx activity or other compensatory GSH-associated detoxication mechanisms.

Effects of selenium supplementation on blood and urine selenium levels and liver function in patients with primary biliary cirrhosis

To study the mechanism of the reduced serum selenium concentration in patients with liver damage we administered 200 micrograms (2.53 mumol) selenium daily as selenium-rich yeast to 8 patients with primary biliary cirrhosis and 8 healthy controls over 16 weeks. Initially selenium concentrations in serum were 24% lower (P less than 0.001) in patients than controls. During supplementation serum selenium levels increased in both groups but the difference between them persisted. Throughout the study whole blood selenium levels and glutathione peroxidase activities were also somewhat lower (P = NS) in patients than controls. Selenium supplementation had no effect on whole blood glutathione peroxidase activities in either group. The basal 24 h urinary excretion of selenium was similar in both groups but was increased more by supplementation in patients than controls. Selenium administration did not influence the liver function of the patients. We conclude that impaired hepatic production of selenium-containing serum compounds is the most likely explanation for the reduced serum selenium concentration in patients with primary biliary cirrhosis.

Effect of fat on human liver selenium concentration

Liver samples from 94 adult men and eight fetuses were obtained at autopsy from the Helsinki region. After lyophilization, the samples were analyzed for selenium (Se) both before and after extraction of fat with hexane/isopropanol. An inverse exponential relationship (R2 = 0.63) existed between unextracted adult liver Se concentration and the corresponding liver fat concentration. The relationship ceased to exist when Se was determined on the defatted tissue. The mean defatted adult liver Se concentration, 16.8 microM/kg dry wt, was significantly higher (p less than 0.001) than that of unextracted samples, 12.1 microM/kg. The Se concentration of fetal liver was not affected by the fat extraction. An age relationship (p less than 0.01) was found between subjects under 25 y and those over 40 y when the Se concentration was expressed per unextracted liver tissue but when expressed per defatted liver tissue the difference between age groups widened to comprise subjects over 60 y. Hepatic fat (mean Se concentration 2.7 microM/kg) thus constitutes a diluting factor. We conclude that the Se concentration of fatty human liver results in an underestimation of the selenium status of subjects who have an unphysiologically high liver fat concentration.

Determination of selenium in human spermatozoa and prostasomes using base digestion and electrothermal atomic absorption spectrophotometry

A method for the determination of selenium in human spermatozoa and prostasomes is described. The samples were digested with 25% (w/v) tetramethylammonium hydroxide (TMAH) in methanol and analyzed by atomic absorption spectrometry with electrothermal atomization and Zeeman background correction (ET-AAS). Nickel was used as a matrix modifier. Calibration was performed using the matrix-based calibration curve. The TMAH-digestion method agreed well with a conventional digestion procedure using concentrated nitric acid. The TMAH-digestion does not require heating or strong acids and it was suitable for small biological samples. The average recovery of added selenium in spermatozoan digests was 95.1 +/- 5.2% (n = 5). The coefficient of variation was 9.1% (n = 21). The accuracy of the method tested with the NBS standard 1577 (bovine liver, certified at 1.1 +/- 0.1 micrograms Se/g) resulted in a value of 0.98 +/- 0.10 micrograms Se/g (n = 16). The method was further tested in an interlaboratory comparison study.

Blood and liver selenium concentrations in patients with liver diseases

To study the relation between blood and liver selenium levels in hepatic disorders we measured the selenium concentrations of whole blood, serum and liver tissue obtained at laparoscopy in 17 patients with different kinds of liver diseases. As compared to healthy controls the mean concentration of selenium was decreased by 24% (p less than 0.001) in the whole blood of the patients (n = 15). Similarly, the mean concentration of selenium in serum was 35% lower in the patients than in the controls (p less than 0.001). As compared to the control samples obtained at autopsy the selenium content of liver was decreased by 13% (p less than 0.05) in the patients. Significant positive correlations were found between the selenium content of the liver and the whole blood (r = 0.62, p less than 0.05) as well as also between liver and serum (r = 0.52, p less than 0.05) selenium concentrations. In conclusion, the present study suggests that in patients with liver disorders the selenium concentrations are decreased not only in the blood but also in the liver tissue. Whether this means a decreased activity of hepatic glutathione peroxidase and, further, an increased possibility of oxidative cell injury, remains open.

Serum selenium concentrations in ovarian cancer patients using a simplified fluorimetric procedure

The serum selenium (Se) concentrations were determined to be 105.6±15.6 μg/L ([Formula: see text]) and 116.7±18.4 μg/L ([Formula: see text]) for the ovarian cancer patients and the control subjects in Singapore, respectively (p<0.0065). When we separated the patients into three age groups, namely <30, 30-50, and >50 yr, the ovarian cancer patients showed significantly lower mean serum Se levels than the control subjects for the 30-50-yr age group only. However, when the analysis of variance was used to evaluate the data, the values indicated that the age of the subject did not significantly affect the serum Se level. Our findings suggest that there is an inverse relationship between serum Se concentration and the incidence of human ovarian cancer.A modified simple fluorimetric method for the determination of serum Se concentration is described. The procedure, with a sensitivity limit of 5 μg/L and percentage recoveries of 96.2-100.7%, requires only 0.2 mL of serum sample.