Observations on the levels of total mercury (Hg) and selenium (Se) in species common to the artisanal fisheries of Seychelles

Exposure to mercury (Hg) in Seychelles is expected to be high owing to the large amounts of fish regularly consumed. In spite of this consumption, a recent long-term study of child development found no evidence that higher prenatal exposure to Hg increases the risk of neurological disorders. To identify the major sources of mercury in the diets of Seychellois fish consumers, 16 species of fish common to local markets were tested for total Hg. Selenium (Se), which may act as an antidote to Hg toxicity, was also measured. Mercury and selenium were measured using standardised laboratory procedures. The average total Hg concentration across all species was 0.07 mg/kg while the Se concentrations averaged 0.29 mg/kg. Based on the pooled species dataset, there was no correlation between total Hg and Se concentrations, suggesting that joint bioaccumulation of these elements does not occur in the reef fishes tested. Barracuda (Sphyraena jello) had the highest concentration of Hg (0.36 mg/kg), a level that was below European Union guidelines. Although Seychellois traditionally eat a large amount of fish, barracuda would need to be consumed more than 5 times a week for FAO/WHO Total Hg Provisional Tolerable Weekly Intake (PTWI) limits to be exceeded, an unusual rate of consumption. Further investigations are needed to assess the risks posed to the population through the consumption of marine fish and fish products.     

Correlates of toenail selenium and its cross‐sectional association with metabolic syndrome

Background

The present study aimed to identify independent correlates of toenail selenium levels and to examine the association between toenail selenium levels and metabolic syndrome in Korean adults.

Methods

Cross‐sectional analysis was conducted using baseline data from the Trace Element Study of Korean Adults in the Yeungnam area, an ongoing cohort study of Korean adults over the age of 35 years. The baseline survey consisted of questionnaires on demographics, lifestyle characteristics and medical information. Dietary information was obtained through a validated semi‐quantitative food frequency questionnaire. Toenail selenium levels were quantified using neutron activation analysis. Biomarkers associated with metabolic syndrome were obtained from biennial medical check‐ups.

Results

In the multivariable‐adjusted analyses, independent lifestyle and dietary correlates of higher selenium levels were alcohol drinking (4.62% higher than nondrinking) and egg intake (0.43% higher per weekly serving), whereas current smoking (5.42% lower than nonsmoking) and vegetable consumption (0.05% lower per weekly serving) were associated with lower toenail selenium levels. In the multivariable adjusted logistic regression, no significant association was observed between toenail selenium levels and metabolic syndrome (odds ratio = 1.33, 95% confidence interval = 0.58–3.05).

Conclusions

Multiple lifestyle and dietary factors influenced toenail selenium levels, although no meaningful association was observed between toenail selenium levels and metabolic syndrome in Korean adults. Future prospective large‐scale cohort studies are required to determine whether there is a causal relationship between selenium levels and metabolic syndrome in Korean adults.

     

白芍总苷联合硒酵母对Graves病患者促甲状腺激素受体抗体水平及突眼度的影响

目的 观察白芍总苷联合硒酵母对Graves病患者促甲状腺激素受体抗体(TRAb)水平及突眼度的影响.方法 选取本院内分泌科门诊2019年10月至2020年2月收治的90例Graves患者为研究对象,按随机数字表法将其分为对照组、治疗组1、治疗组2,各30例.三组均予以甲巯咪唑治疗,治疗组1在此基础上加用硒酵母治疗,治疗组2在治疗组1基础上加用白芍总苷治疗.比较三组治疗前及治疗3、6个月后的甲状腺功能指标,治疗前与治疗6个月后的左、右眼突眼度差值,治疗6个月后甲巯咪唑的使用总量及不良反应发生情况.结果 治疗前,三组患者的FT3、FT4、TSH、T3、T4、TRAb水平比较,差异无统计学意义(P>0.05);治疗3、6个月后,三组患者的FT3、FT4、T3、T4、TRAb水平均低于治疗前,TSH水平均高于治疗前,差异具有统计学意义(P<0.01);治疗3、6个月后,治疗组1、治疗组2的FT3、FT4、T3、T4、TRAb水平均低于对照组,且治疗组2低于治疗组1,差异具有统计学意义(P<0.05);治疗3、6个月后,治疗组1、治疗组2的TSH水平均高于对照组,且治疗组2高于治疗组1,差异具有统计学意义(P<0.05).治疗组2治疗前与治疗6个月后的左、右眼突眼度差值均低于对照组、治疗组1,治疗6个月后甲巯咪唑的使用总量少于对照组、治疗组1,差异具有统计学意义(P<0.05).三组治疗期间的不良反应总发生率比较,差异无统计学意义(P>0.05).结论 白芍总苷联合硒酵母治疗Graves病能降低患者的TRAb水平,延缓突眼的发展,减少甲巯咪唑的使用总量,提高抑制甲状腺激素的效果,改善症状,值得临床推广应用.     

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目的观察不同硒水平作用的大鼠牙齿脱矿情况,探讨硒与龋易感性的关系。方法2013年8月至10月于吉林大学口腔医学院将12只妊娠Wistar大鼠按体重随机分为4组,自受孕之日开始分别喂食无硒（对照组）、低硒（含硒量0．015mg／kg）、中硒（含硒量0．15mg／kg）、高硒（含硒量1．5mg／kg）饲料,喂至母鼠分娩后21d,给断乳仔鼠继续喂食原饲料。处死44日龄仔鼠,取其上下颌后牙经人工致龋液处理,用增强肉眼光学检查、激光龋齿诊断仪DIAGNOdent、激光共聚焦扫描显微镜（CLSM）检测不同硒水平作用下大鼠牙齿脱矿程度。结果4组大鼠牙齿脱矿程度差异均有统计学意义（均P〈0．05）。增强肉眼光学检查、激光龋齿诊断仪及CLSM等3种不同方法检测均显示随硒增高大鼠牙齿脱矿程度加重,但低硒组脱矿程度明显低于对照组,差异有统计学意义（P〈0．05）。结论发育时期摄入硒能影响牙的龋易感性,高水平硒使大鼠牙齿更易于龋坏,低水平硒可降低龋易感性。     

孕期硒营养状况对母婴结局的影响

硒是机体生长发育及代谢所必需的元素,孕期硒营养不良可能会对妊娠结局产生不良影响,因此孕妇保持适宜的硒营养状态是非常重要的。但目前针对孕妇硒营养状态的评估方法及孕期是否需要常规补硒尚未达成共识,尚需更多更深入的研究提供依据。本文就孕期硒营养状况对母婴结局的影响作一述评,旨在为临床提供一定的参考。     

硒和维生素E对心肌成纤维细胞Ⅰ型胶原合成代谢的影响

目的：研究硒（Se）及维生素E（VE）对去甲肾上腺素（NE）处理的心肌成纤维细胞（CFbs）Ⅰ型胶原合成的影响。方法：酶消化法获得Wistar大鼠乳鼠CFbs,与NE、Se和VE作用一定时间后,测定上清中羟脯氨酸（HYP）和Ⅰ型胶原含量。结果：Se、VE及Se+VE组培养液中HYP含量分别为（64.88±1.25）、（47.60±1.59）和（41.34±1.73）mg·L^-1 prot,明显低于NE组［（68.27±1.89）mg·L^-1 prot］（P<0.05）,Ⅰ型胶原含量分别为(0.67±0.05)、(0.40±0.03)和 0.39±0.04,与NE组（0.90±0.15）比较,差异有显著性（P<0.05）。结论：Se和VE单独应用可抑制CFbs Ⅰ型胶原的合成,二者联合应用具有协同作用。        

Toxic effects arising from selenium and deferasirox interaction in the biological system

This investigation was conducted to evaluate the effect of deferasirox on selenium toxicity in male rat organs. After 50 days of selenium administration, all the rats showed toxicity symptoms. After poisoning, deferasirox was given orally to rats during 10 days. The results show that toxicity symptoms were unexpectedly increased. The new symptoms of toxicity after deferasirox administration were including loss of body hairs, yellowish discoloration of hair, weakness, brown spot on their skin, enlargement of the spleen and shrinking of sex organs. Selenium and iron concentrations were determined by GFAAS and FAAS, respectively. The results indicate the poisoned rats with selenium that received deferasirox as a drug, shown serious symptoms such as exacerbate toxicity, reduction in iron concentration, anemia and even death after a few days of deferasirox administration.     

Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.     

Biomarkers of Selenium Status

The essential trace element, selenium (Se), has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potential; and very high Se intakes can produce adverse effects. This hierarchy of biological activities calls for biomarkers informative at different levels of Se exposure. Some Se-biomarkers, such as the selenoproteins and particularly GPX3 and SEPP1, provide information about function directly and are of value in identifying nutritional Se deficiency and tracking responses of deficient individuals to Se-treatment. They are useful under conditions of Se intake within the range of regulated selenoprotein expression, e.g., for humans <55 μg/day and for animals <20 μg/kg diet. Other Se-biomarkers provide information indirectly through inferences based on Se levels of foods, tissues, urine or feces. They can indicate the likelihood of deficiency or adverse effects, but they do not provide direct evidence of either condition. Their value is in providing information about Se status over a wide range of Se intake, particularly from food forms. There is need for additional Se biomarkers particularly for assessing Se status in non-deficient individuals for whom the prospects of cancer risk reduction and adverse effects risk are the primary health considerations. This would include determining whether supranutritional intakes of Se may be required for maximal selenoprotein expression in immune surveillance cells. It would also include developing methods to determine low molecular weight Se-metabolites, i.e., selenoamino acids and methylated Se-metabolites, which to date have not been detectable in biological specimens. Recent analytical advances using tandem liquid chromatography-mass spectrometry suggest prospects for detecting these metabolites.