Serum selenium and selenoprotein P in patients with silicosis

ObjectivesSelenoprotein P (SeP) is a selenium (Se) supply protein, which is an antioxidant micronutrient considered to be vital for human health. The aim of this study was to assess the serum selenium status in patients with silicosis.MethodsWe conducted a retrospective case–control study where serum samples from a total of 78 patients (males with a median age of 73.5 years old) with silicosis and 20 healthy controls (males with a median age of 72.5 years old) were assayed for Se and SeP. They underwent medical and job history taking, lung function testing, and chest radiography examinations. Levels of serum Se were measured using electrothermal atomic absorption spectrophotomerty, while levels of SeP were assessed with sandwich Enzyme Immunoassay. Spearman's rank correlation test was carried out to evaluate the relationship between Se and SeP. The Mann–Whitney test was used to evaluate differences in serum Se and SeP between study groups.ResultsThe median serum Se and SeP concentrations were significantly lower in cases (74.0 μg/l and 4.2 mg/l, respectively) compared with controls (116.0 μg/l and 5.8 mg/l, respectively). In both cases and controls, serum Se was positively correlated with serum SeP (rho = 0.781, p < 0.001 and rho = 0.768, p < 0.001, respectively). Serum Se and SeP levels were significantly lower in patients classified in category four compared with those who were classified in category two or three.ConclusionsSerum Se and SeP concentrations were found to be at inadequate levels in patients with silicosis, and decreased significantly with the severity of the disease.     

High levels of plasma selenium are associated with metabolic syndrome and elevated fasting plasma glucose in a Chinese population: A case-control study

BackgroundSelenium is important for human health and involved in various metabolic processes. Deficiency of selenium associates with increased risk for cancer and cardiovascular diseases. There has been an increase use of selenium supplements for the treatment of autoimmune thyroid conditions. However, the potential biological effects of selenium overload arouse the public concern. The aim of this study was to investigate the associations of plasma selenium concentrations of adults with metabolic syndrome (MS) in Chinese population.MethodsA matched case-control study including 204 metabolic syndrome patients and 204 healthy controls was conducted in 2012. The MS cases were defined according to the criteria of Chinese Diabetes Society (CDS). Healthy controls without abnormality of metabolic components were matched with cases in age, gender and region. Plasma concentrations of selenium were determined by graphite furnace atomic absorption spectrometry (GFAAS). Fasting plasma glucose (FPG), total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL), and low density lipoprotein cholesterol (LDL) were detected by automatic biochemical analyzer.ResultsThe median levels of plasma selenium in MS group were 146.3 (107.3–199.4) μg/L, which were significantly higher than that in the control group (127.4: 95.7–176.0) μg/L; Plasma levels of selenium were related to the risk of MS in dose-response manner. Risk of MS was significantly higher in subjects with plasma selenium in the highest tertile (T3: ≥176.0 μg/L) compared to those in the lowest tertile (T1: <95.7 μg/L) [odds ratio (OR) = 2.416 (95% CI: 1.289–4.526)]. The plasma levels of selenium were positively correlated with fasting plasma glucose (FPG) (r_s = 0.268, P < 0.001). Plasma selenium at the median (T2: 95.7–176.0 μg/L) or upper tertile (T3: ≥176.0 μg/L) was associated with increased risk of elevated FPG (defined by FPG ≥ 6.1 mmol/L) as compared with the lowest tertile (T1: ≤95.7 μg/L) [T2 vs. T1, OR = 3.487 (1.738–6.996); T3 vs. T1, OR = 6.245 (3.005–12.981)].ConclusionsHigher levels of plasma selenium might increase the risk of metabolic syndrome and elevated fasting plasma glucose. Selenium supplements should be used with prudence for CVD and cancer prevention.     

Plasma selenium status in a group of Australian blood donors and fresh blood components

The purpose of this study was to assess plasma selenium levels in an Australian blood donor population and measure extra-cellular selenium levels in fresh manufactured blood components. Selenium levels were measured using graphite furnace atomic absorption spectrometry with Zeeman background correction. The mean plasma selenium level in healthy plasmapharesis donors was 85.6 ± 0.5 μg/L and a regional difference was observed between donors in South East Queensland and Far North Queensland. Although participants had selenium levels within the normal range (55.3–110.5 μg/L), 88.5% had levels below 100 μg/L, a level that has been associated with sub-optimal activity of the antioxidant enzyme glutathione peroxidase (GPx). Extra-cellular selenium levels in clinical fresh frozen plasma (cFFP) and apheresis-derived platelets (APH Plt) were within the normal range. Packed red blood cells (PRBC) and pooled buffy coat-derived platelets (BC Plt) had levels at the lower limit of detection, which may have clinical implications to the massively transfused patient.     

Revised reference values for selenium intake

The German, Austrian and Swiss nutrition societies are the joint editors of the ‘reference values for nutrient intake’. They have revised the reference values for the intake of selenium and published them in February 2015. The saturation of selenoprotein P (SePP) in plasma is used as a criterion for the derivation of reference values for selenium intake in adults. For persons from selenium-deficient regions (China) SePP saturation was achieved with a daily intake of 49 μg of selenium. When using the reference body weights the D-A-CH reference values are based upon, the resulting estimated value for selenium intake is 70 μg/day for men and 60 μg/day for women. The estimated value for selenium intake for children and adolescents is extrapolated using the estimated value for adults in relation to body weight. For infants aged 0 to under 4 months the estimated value of 10 μg/day was derived from the basis of selenium intake via breast milk. For infants aged 4 to under 12 months this estimated value was used and taking into account the differences regarding body weight an estimated value of 15 μg/day was derived. For lactating women compared to non-lactating women a higher reference value of 75 μg/day is indicated due to the release of selenium with breast milk. The additional selenium requirement for pregnant women is negligible, so that no increased reference value is indicated.     

Antioxidant and cytotoxic effect of biologically synthesized selenium nanoparticles in comparison to selenium dioxide

The present study was designed to evaluate antioxidant and cytotoxic effect of selenium nanoparticles (Se NPs) biosynthesized by a newly isolated marine bacterial strain Bacillus sp. MSh-1. An organic–aqueous partitioning system was applied for purification of the biogenic Se NPs and the purified Se NPs were then investigated for antioxidant activity using DPPH scavenging activity and reducing power assay. Cytotoxic effect of the biogenic Se NPs and selenium dioxide (SeO₂) on MCF-7 cell line was assesed by MTT assay. Tranmission electron micrograph (TEM) of the purified Se NPs showed individual and spherical nanostructure in size range of about 80–220 nm. The obtained results showed that, at the same concentration of 200 μg/mL, Se NPs and SeO₂ represented scavenging activity of 23.1 ± 3.4% and 13.2 ± 3.1%, respectively. However, the data obtained from reducing power assay revealed higher electron-donating activity of SeO₂ compared to Se NPs. Higher IC₅₀ of the Se NPs (41.5 ± 0.9 μg/mL) compared to SeO₂ (6.7 ± 0.8 μg/mL) confirmed lower cytotoxicity of the biogenic Se NPs on MCF-7 cell line.     

Selenium deficiency in children and adolescents nourished by parenteral nutrition and/or selenium-deficient enteral formula

The authors analyzed serum selenium levels of 95 children and adolescents with intestinal dysfunction and/or neurological disabilities [age range: 7 months–20 years; mean ± standard deviation (SD): 8.0 ± 5.3 years] who received parenteral nutrition (PN) and/or enteral nutrition (EN) with either reduced or no selenium doses for more than 3 months. Twenty-eight patients (29%) showed serum selenium levels below 4.0 μg/dL. Five patients whose serum selenium levels were below 2 μg/dL presented various clinical manifestations, including hair browning (n = 5), macrocythemia (n = 4), nail whitening (n = 3) and cardiac dysfunction (n = 1). None of these 5 patients were nourished through ordinary diets. Three of these patients were nourished through selenium-free enteral nutritional products, 1 through selenium-deficient PN and 1 through PN and a formula with reduced selenium. After selenium supplement therapy for 1 year, all 5 patients exhibited improvement in their serum selenium levels and clinical features of selenium deficiency. It is important to be cautious about secondary selenium deficiency in children and adolescents nourished only through EN/PN without an adequate dose of selenium.     

Determination of selenium and its compounds in marine organisms

In this study, we investigate the type and quantity of selenium compounds in fish and marine organisms, using ion-pair reversed phase LC–ICP-MS, developed and applied for the analysis of Atlantic cod, Atlantic salmon, Greenland halibut, Atlantic herring, blue mussel, common crab, scallop, calanus, and Euphasia super. Of the samples examined, the lowest level of selenium was found in farmed Atlantic salmon (0.17 mg Se kg⁻¹ dm). The total selenium extraction efficiency by phosphate buffer was 2.5 times higher in sea plankton and shellfish samples than in fish samples. Analysis of Se species in each hydrolysate obtained by proteolysis showed the presence of selenomethionine, which constituted 41.5% of the selenium compounds detected in hydrolysates of Atlantic herring and 98.4% of those in extracts of Atlantic salmon. Inorganic compounds, such as selenates and selenites, were detected mainly in sea plankton and shellfish samples (<0.13 mg Se kg⁻¹ wm), although no correlation was found between the presence of inorganic compounds and total selenium concentration. The accuracy of the total selenium determination was validated using a certified reference material (oyster tissue (NIST 1566b)). A lyophilised powder of cod (Gadus morhua) was used to validate speciation analysis, enzymatic hydrolysis of lyophilised powder of cod recovered 54 ± 6% of total selenium, and SeMet constituted 83.5 ± 5.28% of selenium detected in hydrolysates. The chromatographic detection limits were, respectively, 0.30 ng mL⁻¹, 0.43 ng mL⁻¹, 0.54 ng mL⁻¹, 0.55 ng mL⁻¹, 0.57 ng mL⁻¹ and 0.72 ng mL⁻¹ for selenate, selenomethionine, selenite, Se-methyl-selenocysteine, selenocystine and selenomethionine selenoxide.The data on selenium concentrations and speciation presented here could be useful in estimating levels of selenium intake by seafood consumption.     

Biomedical potential of actinobacterially synthesized selenium nanoparticles with special reference to anti-biofilm,anti-oxidant,wound healing,cytotoxic and anti-viral activities

Currently, there is an ever-increasing need to develop environmentally benign processes in place of synthetic protocols. As a result, researchers in the field of nanoparticle synthesis are focusing their attention on microbes from rare biological ecosystems. One potential actinobacterium, Streptomyces minutiscleroticus M10A62 isolated from a magnesite mine had the ability to synthesize selenium nanoparticles (SeNPs), extracellularly. Actinobacteria mediated SeNP synthesis were characterized by UV–visible, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and high resolution transmission electron microscopy (HR-TEM) analysis. The UV-spectral analysis of SeNPs indicated the maximum absorption at 510 nm, FT-IR spectral analysis confirms the presence of capping protein, peptide, amine and amide groups. The selenium signals confirm the presence of SeNPs. All the diffraction peaks in the XRD pattern and HR-TEM confirm the size of SeNPs in the range of 10–250 nm. Further, the anti-biofilm and antioxidant activity of the SeNPs increased proportionally with rise in concentration, and the test strains reduced to 75% at concentration of 3.2 μg. Selenium showed significant anti-proliferative activity against HeLa and HepG2 cell lines. The wound healing activity of SeNPs reveals that 5% selenium oinment heals the excision wound of Wistar rats up to 85% within 18 days compared to the standard ointment. The biosynthesized SeNPs exhibited good antiviral activity against Dengue virus. The present study concludes that extremophilic actinobacterial strain was a novel source for SeNPs with versatile biomedical applications and larger studies are needed to quantify these observed effects of SeNPs.     

Selenium status in elderly: Relation to cognitive decline

Studies show that decreased antioxidant system is related to cognitive decline. Thus we aimed to measure selenium (Se) status in Alzheimer's disease (AD) and mild cognitive impairment (MCI) elderly and compared them with a control group (CG). 27 AD, 17 MCI and 28 control elderly were evaluated. Se concentration was determined in plasma and erythrocyte by using hydride generation atomic absorption spectroscopy. Erythrocyte Se concentration in AD group was lower than CG (43.73 ± 23.02 μg/L and 79.15 ± 46.37 μg/L; p = 0.001), but not statistically different from MCI group (63.97 ± 18.26 μg/L; p = 0.156). AD group exhibited the lowest plasma Se level (34.49 ± 19.94 μg/L) when compared to MCI (61.36 ± 16.08 μg/L; p = 0.000) and to CG (50.99 ± 21.06 μg/L; p = 0.010). It is observed that erythrocyte Se decreases as cognition function does. Since erythrocyte reflects longer-term nutritional status, the data point to the importance of the relation between Se exposure and cognitive function. Our findings suggest that the deficiency of Se may contribute to cognitive decline among aging people.     

Serum selenium levels of the very low birth weight premature newborn infants with bronchopulmonary dysplasia

BackgroundThe selenium (Se) is an essential trace element that has a critical role in synthesis and activity of a number of selenoproteins with protective properties against free radical damage. This study was conducted to detect the serum Se concentration in very low birth weight (VLBW) preterm infants and its association with bronchopulmonary dysplasia (BPD).Materials and methodsCord blood Se concentration was determined in 54 neonates with gestation age 30 week or less. Another sample was obtained from these infants at day 28 of birth and serum Se levels were measured by atomic absorption spectrophotometer. All neonates were followed for oxygen dependency at 28 day after birth and 36 week postmenstrual age.ResultsThe mean cord blood Se concentration in studied neonates was 64.78 ± 20.73 μg L^?1. Serum Se concentration was 60.33 ± 26.62 μg L^?1 at age 28-day. No significant correlation was observed for serum Se concentration at birth and at one month after birth (r = ?0.04, p = 0.72). BPD was diagnosed in 25 neonates (46%). The mean serum Se concentration at one month was 57.16 ± 29.68 μg L^?1 in patients with BPD (25 cases) and 63.27 ± 23.6 μg L^?1 in 29 patients without BPD (p = 0.40).ConclusionIn our study, serum Se concentration at 28 day of birth was lower than cord blood levels in preterm neonates, but we have not found significant difference among patients who had BPD or not with respect to serum Se concentrations at this age.     

Use of selenium–silymarin mix reduces lower urinary tract symptoms and prostate specific antigen in men

The aim of this double-blind, placebo controlled clinical trial was to assess the effects of a combination of selenium and silymarin in men with lower urinary tract symptoms, benign prostatic hyperplasia and a prostate specific antigen (PSA) ≤2.5 ng/ml. The volunteers were randomized to two groups: the first one (n = 26) received 240 μg selenium (in the form of yeast l-selenomethionine) plus 570 mg silymarin daily for 6 months and the second (n = 29) received placebo. Outcome measures were changes in the International Prostate Symptom Score (IPSS), bladder volume (V), urinary flow rate, ultrasound estimated postvoid residual urine volume (RV), serum PSA, testosterone and selenium levels, safety clinical biochemistry, hematology and oxidative stress parameters at baseline and on day 180. The results showed statistically significant differences (p < 0.05) between treatment and control groups for the following parameters: IPSS score, urodynamic parameters: maximal rate of urine flow (Q_max), average flow (Q_ave), V and RV, total PSA value and serum selenium levels. There was a significant reduction in PSA in the selenium–silymarin group but no effect on blood testosterone level. Overall the treatment was well-tolerated with no adverse effects.     

The impact of acute lung injury,ECMO and transfusion on oxidative stress and plasma selenium levels in an ovine model

The purpose of this study was to determine the effects of smoke induced acute lung injury (S-ALI), extracorporeal membrane oxygenation (ECMO) and transfusion on oxidative stress and plasma selenium levels. Forty ewes were divided into (i) healthy control (n = 4), (ii) S-ALI control (n = 7), (iii) ECMO control (n = 7), (iv) S-ALI + ECMO (n = 8) and (v) S-ALI + ECMO + packed red blood cell (PRBC) transfusion (n = 14). Plasma thiobarbituric acid reactive substances (TBARS), selenium and glutathione peroxidase (GPx) activity were analysed at baseline, after smoke injury (or sham) and 0.25, 1, 2, 6, 7, 12 and 24 h after initiation of ECMO. Peak TBARS levels were similar across all groups. Plasma selenium decreased by 54% in S-ALI sheep (1.36 ± 0.20 to 0.63 ± 0.27 μmol/L, p < 0.0001), and 72% in sheep with S-ALI + ECMO at 24 h (1.36 ± 0.20 to 0.38 ± 0.19, p < 0.0001). PRBC transfusion had no effect on TBARS, selenium levels or glutathione peroxidase activity in plasma. While ECMO independently increased TBARS in healthy sheep to levels which were similar to the S-ALI control, the addition of ECMO after S-ALI caused a negligible increase in TBARS. This suggests that the initial lung injury was the predominant feature in the TBARS response. In contrast, the addition of ECMO in S-ALI sheep exacerbated reductions in plasma selenium beyond that of S-ALI or ECMO alone. Clinical studies are needed to confirm the extent and duration of selenium loss associated with ECMO.     

Immobilized Triton X-100-assisted refolding of Green Fluorescent Protein-Tobacco Etch Virus protease fusion protein using β-cyclodextrin as the eluent

A new protein refolding technique based on the use of the non-charged detergent Triton X-100 immobilized to the cross-linked agarose gel Sepharose High Performance has been developed. The new solid phase was used in combination with soluble β-cyclodextrin (β-CD) to refold recombinant Green Fluorescent Protein fused to Tobacco Etch Virus protease (GFPTEVP) expressed as inclusion bodies in E. coli. Previous attempts to refold recombinant GFPTEVP by dilution had failed. In the new procedure a column packed with Triton X-100-coupled Sepharose High Performance was used to capture unfolded GFPTEVP followed by elution using an increasing β-CD concentration gradient. The yield of properly refolded GFPTEVP was 46% at a protein concentration of 380 μg/ml. In contrast, dilution refolding of GFPTEVP at 200 μg/ml refolding buffer resulted in only 4.7% of native protein.     

MTs in Palaemonetes argentinus as potential biomarkers of zinc contamination in freshwaters

Aquatic invertebrates take up and accumulate essential and non-essential trace metals even when both are likely to be poisonous. In order to study the potential of the metallothioneins (MTs) as biomarkers of metal contamination in native shrimp Palaemonetes argentinus, organisms have been exposed at 0, 5, 50 and 500 μg L⁻¹ of zinc for 96 h. Moreover, accumulation and subcellular distribution of this essential metal were evaluated. A significant Zn accumulation was observed in different body sections. Higher Zn levels occurred in cephalothorax compared to abdomen, especially at the highest exposure concentration (500 μg Zn L⁻¹). A clear differential subcellular metal distribution between cephalothorax and abdomen was also observed. In cephalothorax Zn was similarly distributed between the soluble and insoluble fractions; while in abdomen, when total Zn increased, insoluble metal augmented more markedly than the soluble one. Cytosolic Zn levels increased more in cephalothorax than in abdomen of shrimps exposed to 500 μg Zn L⁻¹ when compared to control. Finally, a significant induction of MTs was observed in cephalothorax at 500 μg Zn L⁻¹. A potential role for MTs as biomarkers in P. argentinus should be further studied to enhance the sensitivity of the response, although it is likely that MTs play a key role in metal detoxification since the increase of these proteins is linked to metal challenge.     

Optimization of ultrasound-assisted extraction conditions for total phenols with anti-hyperglycemic activity from Psidium guajava leaves

The high concentration of total phenolic compounds (TPC) in Psidium guajava leaf extracts (GvEx) is correlated to its anti-hyperglycemic activity. In this study, we established the optimum ultrasound extraction conditions for maximizing TPC yield. The response surface methodology (RSM) was employed for empirical model building. The maximum value of TPC (26.12%) was obtained at solvent to solid ratio (v/w) of 12.1, extraction temperature of 59.8 °C, and extraction time of 5.1 min. The anti-hyperglycemic activity of GvEx was compared to the commonly used diabetic drug acarbose. The IC₅₀ of GvEx for α-amylase and α-glucosidase inhibition was 50.5 μg/mL and 34.6 μg/mL, respectively. However, the IC₅₀ of acarbose for α-amylase and α-glucosidase inhibition was 95.3 μg/mL and 1075.2 μg/mL, respectively. In conclusion, GvEx obtained under optimum extraction conditions had higher anti-hyperglycemic activity than acarbose. In addition, the recommended extraction procedures for GvEx save time and are environmentally friendly.     

Effects of nationwide addition of selenium to fertilizers on foods,and animal and human health in Finland: From deficiency to optimal selenium status of the population

Despite different geological features the Nordic countries are generally selenium-poor areas. In each country various factors such as food importation and life-style determine the selenium (Se) intake. Due to an extremely low Se intake in the 1970s in Finland, 0.025 mg/day, an official decision was made in 1984 to supplement multinutrient fertilizers with Se in the chemical form of sodium selenate. Almost all fertilizers used in Finland since 1985 have contained Se. Currently all crop fertilizers contain 15 mg Se/kg. Finland is still the only country to take this country-wide measure.In a national monitoring programme, sampling of cereals, basic foodstuffs, feeds, fertilizers, soils, and human tissues has been carried out annually since 1985 by four governmental research organizations. Sampling of foods has been done four times per year and human blood has been obtained annually from the same (n = 60) adults. The accuracy of analyses has been verified by annual interlaboratory quality control. During this programme the selenium concentration of spring cereals has increased on average 15-fold compared with the level before the Se fertilization. The mean increase in the Se concentration in beef, pork and milk was 6-, 2- and 3-fold. In terms of Se, organically grown foods of plant origin are generally comparable to products produced before the Se supplementation of fertilizers. Milk from organically fed cows is 50% lower in Se than the usual milk. The average dietary human intake increased from 0.04 mg Se/day/10 MJ in 1985 to a present plateau of 0.08 mg Se/day/10 MJ, which is well above the current nutrition recommendations. Foods of animal origin contribute over 70% of the total daily Se intake. The mean human plasma Se concentration increased from 0.89 μmol/L to a general level of 1.40 μmol/L that can be considered to be an optimal status. The absence of Se deficiency diseases and a reference population have made conclusions on the impact on human health difficult. However, the rates of cardiovascular diseases and cancers have remained similar during the pre- and post-supplementation indicating medical and life-style factors to be much stronger determinants than Se. The nationwide supplementation of fertilizers with sodium selenate is shown to be effective and safe in increasing the Se intake of the whole population. Also, the health of animals has improved.     

Nutritionally rich marine proteins from fresh herring by-products for human consumption

Marine oils and proteins are valuable compounds, but under unfavorable conditions these components are easily oxidized and enzymatically degraded. We have designed an industrial process for producing high quality human grade proteins from fresh herring by-products. Two different processes were tested in semi-industrial scale: (i) thermal extraction to separate oil and proteins and (ii) enzymatic hydrolysis with different commercial proteases to produce fish protein hydrolysates (FPH) and separate oil. Both stick water from thermal extraction and fish protein hydrolysates, after hydrolysis, are nutritionally rich fractions and yielded approx. 18 and 25% of dry material in these fractions respectively. Neither season nor enzymes used influenced the color of hydrolysate powders, but time and temperature of the processes are important tools for controlling the color. Fishing seasons did not influence bitterness of hydrolysates and stick water samples, but both the process conditions and applied enzymes played an important role for the formation of bitterness. Insoluble fractions after both processes had significantly higher protein efficiency ratio: 3.08 and 2.93 compared to soluble fractions: 2.62 and 2.76 after hydrolysis and thermal extraction respectively. Both stick water and FPH showed antioxidative activity against both iron (15 μM of Fe³⁺) and hemoglobin (80 ppm) induced oxidation. Herring proteins (1.25 mg/ml) were able to reduce iron induced oxidation by 50–70%, while Hb induced oxidation was reduced by 70–80% using 4 mg/ml proteins concentration.     

The association between serum selenium and gestational diabetes mellitus: A systematic review and meta-analysis

BackgroundResults of the studies about association between serum selenium concentration and gestational hyperglycemia are inconsistent. Some studies have demonstrated that women with gestational diabetes mellitus (GDM) have lower Se concentrations while contrary results are reported in other studies.AimThe aim of this study is to compare the serum Se concentration in women with GDM and normoglycemic pregnant women via a systematic review and meta-analysis.MethodsA computerized literature search on four databases (PubMed, Cochrane register of control trials, Scopus and Google scholar) was performed from inception through August 2013. Necessary data were extracted and random effects model was used to conduct the meta-analysis.ResultsSix observational studies (containing 147 women with GDM and 360 normoglycemic pregnant women) were found, which had compared serum Se concentration in women suffering from GDM with normal pregnant ones. Our meta-analysis revealed that serum Se concentration was lower in women with GDM compared to normoglycemic pregnant women (Hedges = −1.34; 95% CI: −2.33 to −0.36; P < 0.01). Stratified meta-analysis demonstrated that concentration of Se in the sera of women with GDM was lower than normal pregnant women both in second and third trimesters, but the result was not significant in second trimester (second trimester: Hedges = −0.68; 95% CI: −1.60−0.25; P = 0.15, third trimester: Hedges = −2.81; 95% CI: −5.21 to −0.42; P < 0.05). It was also demonstrated that serum Se status was lower in pregnant women with impaired glucose tolerance (IGT) compared to normoglycemic pregnant women (Hedges = −0.85; 95% CI: −1.18 to −0.52).ConclusionThe available evidences suggest that serum Se concentration is significantly lower in pregnant women with gestational hyperglycemia compared to normal pregnant women.     

Male infertility: Decreased levels of selenium,zinc and antioxidants

In this study, we aimed to compare the level of zinc, selenium, glutathione peroxidase activity and antioxidant status in following populations of men: severe inflammation in prostate (>10⁶ white blood cells in prostate secretion; n = 29), severe leukocytospermia, (>10⁶ white blood cells in semen; n = 31), mild inflammation, (0.2–1 M white blood cells in semen or prostate secretion; n = 24), non-inflammatory oligozoospermia (n = 32) and healthy controls (n = 27). Male partners of infertile couples had reduced level of antioxidative activity, selenium and zinc in their seminal plasma. Most importantly, reduced selenium levels were evident in all patient groups regardless of inflammation status. Therefore, these patients might gain some benefit from selenium supplementation.     

Design,expression and characterization of the hybrid antimicrobial peptide LHP7, connected by a flexible linker,against Staphylococcus and Streptococcus

The emergence of bacterial resistance to common antibiotics poses a threat to human health and has rekindled an interest in antimicrobial peptides (AMPs). LHP7, a novel hybrid AMP containing 83 amino acid residues was designed on the basis of the LH28 and plectasin. LHP7 was expressed in Pichia pastoris, the total concentration of secreted protein reached 0.906 g/L after 108 h of methanol induction. Its antimicrobial activity was higher than that of the parent AMPs; the minimal inhibitory concentrations (MICs) of LHP7 against Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus suis were 0.091, 0.023 and 0.18 μM, respectively. The antibacterial activity of LHP7 against clinical MRSA isolates (MICs = 0.73–2.91 μM) was enhanced over that of plectasin. The fractional inhibitory concentration (FIC) indicated a synergistic effect between LHP7 and ampicillin against MRSA (FIC = 0.375), and combinations of LHP7 with gentamicin, rifampin or tetracycline provided evidence of additive effects (FIC = 0.625–1.0). LHP7 exhibited a broad range of pH stability and thermostability, and a hemolytic activity of less than 5% below a concentration of 500 μg/mL. It was resistant to pepsin and papain digestion, but sensitive to trypsin digestion. These results suggest that LHP7 might have potential as a broadly applied and clinically useful antimicrobial agent.