BACKGROUND & AIMS: :5-Selenium-substituted derivatives (diselenides) or uracil, 2'-deoxyuridine, and 2'-deoxyuridylic acid were synthesized via the addition of methyl hypobromite to the 5,6 double bond, followed by reaction of the adducts with sodium diselenide. The physical and chemical properties of these compounds (including their facile reduction by dithiothreitol and rapid reoxidation) were similar to those of the corresponding 5-sulfur analogues. 5-Hydroseleno-2'-deoxyuridylic acid was as potent as 5-mercapto-2'-deoxyuridylate in inhibiting thymidylate synthetase from L. casei (ki approximately 6 X 10(-8) M) but the nucleoside III was considerably less active than 5-mercapto-2'-deoxyuridine in the inhibition of growth of the leukemia L1210 cell in culture.

背景与目标： 通过向5，6双键中添加次溴酸甲酯，然后使加合物与二硒化钠反应，合成了：5-硒取代的衍生物（二硒化物）或尿嘧啶，2'-脱氧尿苷和2'-脱氧尿苷酸。这些化合物的物理和化学性质（包括通过二硫苏糖醇轻松还原和快速再氧化）与相应的5-硫类似物相似。 5-Hydroseleno-2'-deoxyuridylicacid与5-mercapto-2'-deoxyuridylate一样有效，可抑制干酪乳杆菌的胸苷酸合成酶（ki约为6 X 10（-8）M），但核苷III的活性远低于5-巯基2'-脱氧尿苷对培养的白血病L1210细胞生长的抑制作用。

BACKGROUND & AIMS: :Next year (2017), the micronutrient Selenium (Se) is celebrating its birthday-i.e., 200 years after first being identified by the Swedish chemist Jöns Jakob Berzelius. Despite its impressive age, research into the functions of this essential trace element is very alive and reaching out for new horizons. This special issue presents some recent fascinating, exciting, and promising developments in Se research in the form of eight original contributions and seven review articles. Collectively, aspects of Se supply, biochemical, physiological, and chemotherapeutic effects, and geobiological interactions are covered by leading scientists in the areas of nutritional, basic, and clinical research. It is obvious from the contributions that the bicentennial anniversary will celebrate a micronutrient still in its infancy with respect to being understood in terms of its biomedical importance.

背景与目标： ：明年（2017年），微量元素硒（Se）正在庆祝其生日，即在被瑞典化学家JönsJakob Berzelius首次发现200周年之后。尽管它具有令人印象深刻的时代，但对这种必需的微量元素的功能的研究仍非常活跃，并且正在开拓新的视野。本期特刊以八篇原创文章和七篇评论文章的形式介绍了硒研究的一些近期有趣，令人振奋和有希望的进展。总体而言，营养，基础和临床研究领域的领先科学家涵盖了硒的供应，生化，生理和化学治疗作用以及地质生物学相互作用等方面。从贡献中可以明显看出，就其生物医学重要性而言，两百周年纪念日将庆祝微量营养素仍处于婴儿期。

BACKGROUND & AIMS: :The lack of highly efficient, inexpensive catalysts severely hinders large-scale application of electrochemical hydrogen evolution reaction (HER) for producing hydrogen. MoS2 as a low-cost candidate suffers from low catalytic performance. Herein, taking advantage of its tri-layer structure, we report a MoS2 nanofoam catalyst co-confining selenium in surface and cobalt in inner layer, exhibiting an ultra-high large-current-density HER activity surpassing all previously reported heteroatom-doped MoS2. At a large current density of 1000 mA cm-2, a much lower overpotential of 382 mV than that of 671 mV over commercial Pt/C catalyst is achieved and stably maintained for 360 hours without decay. First-principles calculations demonstrate that inner layer-confined cobalt atoms stimulate neighbouring sulfur atoms while surface-confined selenium atoms stabilize the structure, which cooperatively enable the massive generation of both in-plane and edge active sites with optimized hydrogen adsorption activity. This strategy provides a viable route for developing MoS2-based catalysts for industrial HER applications.

背景与目标： ：缺乏高效，廉价的催化剂严重阻碍了电化学制氢反应（HER）在生产氢气中的大规模应用。 MoS 2作为低成本的候选物具有较低的催化性能。在这里，我们利用其三层结构，报道了一种MoS2纳米泡沫催化剂，将表面硒和内层钴共聚，表现出超高的大电流密度HER活性，超过了以前报道的所有杂原子掺杂的MoS2。在1000 mA cm-2的大电流密度下，与商用Pt / C催化剂相比，实现了比671 mV更低的382 mV的过电势，并且可以稳定地维持360 for小时而不会衰减。第一性原理计算表明，内层约束的钴原子可激发相邻的硫原子，而表面约束的硒原子可稳定结构，从而可共同产生具有最佳氢吸附活性的面内和边缘活性位。该策略为开发用于工业HER应用的基于MoS2的催化剂提供了一条可行的途径。

BACKGROUND & AIMS: :Mononuclear molybdoenzymes of the dimethyl sulfoxide reductase (DMSOR) family catalyze a number of reactions essential to the carbon, nitrogen, sulfur, arsenic, and selenium biogeochemical cycles. These enzymes are also ancient, with many lineages likely predating the divergence of the last universal common ancestor into the Bacteria and Archaea domains. We have constructed rooted phylogenies for over 1,550 representatives of the DMSOR family using maximum likelihood methods to investigate the evolution of the arsenic biogeochemical cycle. The phylogenetic analysis provides compelling evidence that formylmethanofuran dehydrogenase B subunits, which catalyze the reduction of CO2 to formate during hydrogenotrophic methanogenesis, constitutes the most ancient lineage. Our analysis also provides robust support for selenocysteine as the ancestral ligand for the Mo/W atom. Finally, we demonstrate that anaerobic arsenite oxidase and respiratory arsenate reductase catalytic subunits represent a more ancient lineage of DMSORs compared to aerobic arsenite oxidase catalytic subunits, which evolved from the assimilatory nitrate reductase lineage. This provides substantial support for an active arsenic biogeochemical cycle on the anoxic Archean Earth. Our work emphasizes that the use of chalcophilic elements as substrates as well as the Mo/W ligand in DMSORs has indelibly shaped the diversification of these enzymes through deep time.

背景与目标： ：二甲基亚砜还原酶（DMSOR）家族的单核钼酶催化许多碳，氮，硫，砷和硒生物地球化学循环所必需的反应。这些酶也是古老的，有许多谱系可能会在最后一个普遍祖先进入细菌和古细菌域之前就出现分歧。我们已经使用最大似然方法为DMSOR家族的1,550多个代表构建了根系系统发育史，以研究砷生物地球化学循环的演变。系统发育分析提供了令人信服的证据，即甲氢呋喃甲烷脱氢酶B亚基在氢营养型甲烷生成过程中催化CO2还原成甲酸，是最古老的血统。我们的分析还为硒代半胱氨酸作为Mo / W原子的祖先配体提供了有力的支持。最后，我们证明，与好氧亚砷氧化酶催化亚基相比，厌氧亚砷酸氧化酶和呼吸砷还原酶催化亚基代表了更古老的DMSOR谱系，后者是由同化硝酸还原酶谱系演变而来的。这为缺氧古代地球上活跃的砷生物地球化学循环提供了实质性支持。我们的工作强调，在DMSORs中使用嗜酸性元素作为底物以及Mo / W配体已不可磨灭地塑造了这些酶在很长一段时间内的多样化。

BACKGROUND & AIMS: :We have characterized a cDNA pGPX1211 encoding rat glutathione peroxidase I. The selenocysteine in the protein corresponded to a TGA codon in the coding region of the cDNA, similar to earlier findings in mouse and human genes, and a gene encoding the formate dehydrogenase from E. coli, another selenoenzyme. The rat GSH peroxidase I has a calculated subunit molecular weight of 22,155 daltons and shares 95% and 86% sequence homology with the mouse and human subunits, respectively. The 3'-noncoding sequence (greater than 930 bp) in pGPX1211 is much longer than that of the human sequences. We found that glutathione peroxidase I mRNA, but not the polypeptide, was expressed under nutritional stress of selenium deficiency where no glutathione peroxidase I activity can be detected. The failure of detecting any apoprotein for the glutathione peroxidase I under selenium deficiency and results published from other laboratories supports the proposal that selenium may be incorporated into the glutathione peroxidase I co-translationally.

背景与目标： ：我们已经表征了编码大鼠谷胱甘肽过氧化物酶I的cDNA pGPX1211。该蛋白中的硒代半胱氨酸对应于该cDNA编码区中的TGA密码子，类似于小鼠和人类基因中的早期发现，以及一个编码来自E的甲酸脱氢酶的基因大肠杆菌，另一种硒酶。大鼠GSH过氧化物酶I的计算亚单位分子量为22155道尔顿，分别与小鼠和人亚单位具有95％和86％的序列同源性。 pGPX1211中的3'非编码序列（大于930 bp）比人类序列长得多。我们发现，在缺乏硒的营养胁迫下谷胱甘肽过氧化物酶I mRNA而不是多肽被表达，在硒缺乏的情况下，谷胱甘肽过氧化物酶I的活性无法被检测到。在硒缺乏的情况下未能检测到谷胱甘肽过氧化物酶I的任何载脂蛋白，以及其他实验室发表的结果支持了将硒共翻译入谷胱甘肽过氧化物酶I的提议。

BACKGROUND & AIMS: Selenium (Se) in plasma, whole blood and erythrocytes as well as glutathione peroxidase (GSH-Px) activity in plasma and erythrocytes were investigated in 161 healthy Hungarian children aged 1-15 years. Se was determined by AAS with hydride generation. The estimation of GSH-Px activity was performed in plasma with tertbutyl-hydroperoxide (t-BOOH) and in erythrocytes with hydrogen peroxide (H2O2) as acceptor substrates. The Se content in plasma (0.63 +/- 0.12 mumol/L), whole blood (0.81 +/- 0.14 mumol/L) and erythrocytes (1.14 +/- 0.26 mumol/L, the GSH-Px activity in plasma (87 +/- 19 U/L) and erythrocytes (5.93 +/- 1.04 U/gHb) was low in Hungarian children in comparison to values for children from other European countries. Samples from a rural area in southeast Hungary showed even lower Se content than samples from an industrial city in the northwest or from the capital. The Se in plasma and whole blood as well as GSH-Px activity in the plasma exhibited a clear age dependency. There was a good correlation between plasma Se and GSH-Px activity in all children (r = 0.633, p < 0.001). In addition, in children from the northwestern city and from the capital a correlation was found between Se content and GSH-Px activity of erythrocytes (r = 0.625, p < 0.001). There is no indication that the high mortality in young Hungarian adults from cardiovascular diseases is mainly caused by a low Se supply because there are no corresponding findings in the surrounding countries of southeastern or central eastern Europe with similar low Se states.

背景与目标： 在161名1至15岁的匈牙利健康儿童中，研究了血浆，全血和红细胞中的硒（Se）以及血浆和红细胞中的谷胱甘肽过氧化物酶（GSH-Px）活性。用氢化物发生的原子吸收光谱法测定硒。 GSH-Px活性的估计是在血浆中使用叔丁基氢过氧化物（t-BOOH），在红细胞中使用过氧化氢（H2O2）作为受体底物。血浆中的硒含量（0.63 /-0.12μmol/ L），全血（0.81 /-0.14μmol/ L）和红细胞（1.14 /-0.26μmol/ L），血浆中的GSH-Px活性（87 /-19 U与来自其他欧洲国家的儿童相比，匈牙利儿童的/ L）和红细胞（5.93 /-1.04 U / gHb）低。在西北或首都地区，血浆和全血中的硒以及血浆中的GSH-Px活性具有明显的年龄依赖性，所有儿童血浆中的硒与GSH-Px活性之间都具有良好的相关性（r = 0.633） （p <0.001）。此外，在西北城市和首都的儿童中，硒含量与红细胞GSH-Px活性之间存在相关性（r = 0.625，p <0.001）。匈牙利年轻人因心血管疾病而死亡的主要原因是硒供应不足，因为在东南欧或中东欧的周边国家中，也有类似的低硒状态。

BACKGROUND & AIMS: :Selenium (Se) is a trace element contributing to the structure of antioxidant system that saves cells from reactive oxygen species. Low serum Se levels have been reported in pediatric and adult patients with cancers. On the other hand, hair Se levels, predicting the long-term body Se status, have been reported in only adult patients with cancer. The aim of the study was to investigate the hair Se status in children with newly diagnosed lymphoid malignancies and the relation between malnutrition and Se deficiency. Thirty patients with leukemia (n=17) and lymphoma (n=13), and 25 healthy controls were enrolled to the study. Se was determined with atomic absorption spectrophotometrical method. Hair Se levels of the patients were significantly lower than those of control group [666.96+/-341.46 ng/g vs. 1019.22+/-371.83 ng/g (P<0.001)]. Children with lymphoma had lower Se than the children with acute lymphoblastic leukemia but not statistically significant [547.03+/-283.67 ng/g vs. 758.67+/-361.05 ng/g (P>0.05)]. Malnourished patients (11/30) had lower hair Se levels (483.51+/-235.55 ng/g) than those of the controls (P=0.036), whereas the Se levels of the patients who had no malnutrition (773.17+/-352.92 ng/g) were also lower than those of the controls but not statistically significant (P=0.053). There was no correlation between age, sex, and the hair Se levels. In this study, we found that hair Se levels of the children with leukemia and lymphoma, especially those of malnourished patients, were lower than those of controls. Additional studies are needed to determinate whether low levels of hair Se may play a role in carcinogenesis.

背景与目标： ：硒（Se）是一种微量元素，有助于抗氧化系统的结构，从而使细胞免受活性氧的影响。据报道，患儿和成年癌症患者的血清硒水平较低。另一方面，仅在成人癌症患者中报道了预测长期体内硒状态的头发硒水平。这项研究的目的是调查新诊断的淋巴恶性肿瘤患儿的头发硒状况，以及营养不良与硒缺乏之间的关系。该研究招募了30例白血病（n = 17）和淋巴瘤（n = 13）患者，以及25名健康对照。硒采用原子吸收分光光度法测定。患者的头发硒水平显着低于对照组[666.96 /-341.46 ng / g与1019.22 /-371.83 ng / g（P <0.001）]。淋巴瘤患儿的硒含量低于急性淋巴细胞白血病患儿，但无统计学意义[547.03 /-283.67 ng / g vs. 758.67 /-361.05 ng / g（P> 0.05）]。营养不良的患者（11/30）的头发Se水平（483.51 /-235.55 ng / g）低于对照组（P = 0.036），而没有营养不良的患者的Se水平（773.17 /-352.92 ng / g） g）也低于对照组，但无统计学意义（P = 0.053）。年龄，性别和头发硒水平之间没有相关性。在这项研究中，我们发现白血病和淋巴瘤患儿，尤其是营养不良患者的头发硒水平低于对照组。还需要其他研究来确定低含量的头发硒是否可能在致癌过程中起作用。

BACKGROUND & AIMS: :Selenium has been associated with an anti-cancer effect via the modulation of Akt. In order to investigate whether selenium modulates Akt by hitherto unidentified molecular mechanisms, we examined the effect of selenium on the stability and activity of Akt. Selenium induced destabilization of Akt which is coupled to its own enzyme activation. Mutation of T308 and S473 of Akt to alanine as well as the inhibition or depletion of upstream kinases for Akt activation blocked Akt degradation. These features of Akt degradation are reminiscent of the 'activation-induced suicidal degradation' mechanism. PTEN was also required for Akt destabilization as Akt activation alone was unable to elicit Akt degradation in the absence of PTEN. Conversely, PTEN introduction in PTEN-null prostate cancer cells restored the ability to degrade Akt upon selenium treatment. Collectively, selenium seems to achieve ultimate negative regulation of Akt signaling by destabilizing the protein, and this regulation mechanism might provide a paradigm for the anti-cancer activity of selenium.

背景与目标： 硒通过调节Akt与抗癌作用有关。为了研究硒是否通过迄今尚未确定的分子机制调节Akt，我们研究了硒对Akt稳定性和活性的影响。硒诱导的Akt失稳与其自身的酶活化有关。 Akt的T308和S473突变为丙氨酸，以及Akt激活的上游激酶的抑制或耗竭阻止Akt降解。 Akt降解的这些特征使人联想到“活化诱导的自杀降解”机制。 Akt不稳定也需要PTEN，因为在没有PTEN的情况下，仅Akt激活不能引发Akt降解。相反，在无PTEN的前列腺癌细胞中引入PTEN恢复了硒处理后降解Akt的能力。总体而言，硒似乎通过使蛋白质不稳定来实现对Akt信号的最终负调控，并且这种调控机制可能为硒的抗癌活性提供范例。

BACKGROUND & AIMS: BACKGROUND:Low levels of selenium have been associated with increased risk of prostate cancer (PCa). Selenoprotein P is the most abundant selenoprotein in serum and delivers ten selenocysteine residues to tissues. Variation in the selenoprotein P gene (SEPP1) may influence PCa development or modify the effects of selenium. We examined the association of SEPP1 single nucleotide polymorphisms (SNPs) with PCa risk and survival, and tested for interactions. METHODS:The Physicians' Health Study (PHS) is a prospective cohort of 22,071 US physicians; we utilized a nested case-control study of 1,352 PCa cases and 1,382 controls. We assessed four SNPs capturing common variation within the SEPP1 locus. In a subset of men (n = 80), we evaluated SEPP1 mRNA expression in tumors. RESULTS:Two SNPs were significantly associated with PCa risk. For rs11959466, each T allele increased risk (odds ratio (OR) = 1.31; 95% confidence interval (CI): 1.02,1.69; P(trend)  = 0.03). For rs13168440, the rare homozygote genotype decreased risk compared to the common homozygote (OR = 0.56, 95% CI: 0.33, 0.96). Moreover, there was a significant interaction of rs13168440 with plasma selenium; increasing selenium levels were associated with decreased PCa risk only among men with the minor allele (P(interaction)  = 0.01). SEPP1 expression was significantly lower in men with lethal PCa than long-term survivors. CONCLUSIONS:SEPP1 genetic variation was associated with PCa incidence; replication of these results in an independent dataset is necessary. These findings further support a causal link between selenium and PCa, and suggest that the effect of selenium may differ by genetics.

背景与目标： 背景：硒水平过低与前列腺癌（PCa）的风险增加有关。硒蛋白P是血清中含量最丰富的硒蛋白，可向组织输送十个硒代半胱氨酸残基。硒蛋白P基因（SEPP1）的变异可能会影响PCa的发育或改变硒的作用。我们检查了SEPP1单核苷酸多态性（SNP）与PCa风险和生存的关联，并测试了相互作用。
方法：《医师健康研究》（PHS）是美国22,071名医师的前瞻性队列研究。我们利用了对1352个PCa病例和1382个对照的嵌套病例对照研究。我们评估了四个捕获SEPP1基因座内常见变异的SNP。在一组男性患者中（n = 80），我们评估了SEPP1 mRNA在肿瘤中的表达。
结果：两个SNP与PCa风险显着相关。对于rs11959466，每个T等位基因的患病风险增加（几率（OR）= 1.31； 95％置信区间（CI）：1.02,1.69； P（趋势）= 0.03）。对于rs13168440，与普通纯合子相比，罕见的纯合子基因型降低了风险（OR = 0.56，95％CI：0.33，0.96）。此外，rs13168440与血浆硒之间存在显着的相互作用。硒水平升高与等位基因较小的男性中PCa风险降低相关（P（相互作用）= 0.01）。具有致死性PCa的男性SEPP1表达明显低于长期存活者。
结论：SEPP1基因变异与PCa发生率有关。必须将这些结果复制到独立的数据集中。这些发现进一步支持了硒与PCa之间的因果关系，并表明硒的作用可能因遗传因素而有所不同。

BACKGROUND & AIMS: The effects of lead (Pb) and selenium (Se) interactions on central nervous system (CNS) functions were seen in adult rats by both biochemical and histologic pathological alterations. Pb administration of 20 mg/kg body wt for 8 wk showed degenerative changes only in the cerebral cortex. The changes in the cerebellar regions were not significant. Biochemically a marked decrease in the DNA, RNA, and protein content was seen following lead treatment. These decreases were significant in both the regions of the brain. During the concomitant administration of Pb and Se, the alterations in the transverse section of cerebral cortex showed only marginal changes. The values of DNA and RNA content showed significant improvement in both regions of the brain compared to the Pb treated group.

背景与目标： 通过生化和组织病理学改变，观察到成年大鼠中铅（Pb）和硒（Se）相互作用对中枢神经系统（CNS）功能的影响。连续8周每周施用20 mg / kg体重的铅，仅在大脑皮层中显示出退行性变化。小脑区域的变化不明显。铅处理后，发现生化方面的DNA，RNA和蛋白质含量显着下降。这些减少在大脑的两个区域都是显着的。在同时施用铅和硒的过程中，大脑皮层横断面的变化仅显示出边缘变化。与Pb治疗组相比，DNA和RNA含量的值在大脑的两个区域均表现出显着改善。

BACKGROUND & AIMS: :Two experiments were conducted on broiler chickens to compare the effect of a new organic Se source, 2-hydroxy-4-methylselenobutanoic acid (HMSeBA; SO), with two practical Se additives, sodium selenite (SS) and Se yeast (SY). The relative bioavailability of the different Se sources was compared on muscle (pectoralis major) total Se, selenomethionine (SeMet) and selenocysteine (SeCys) concentrations and apparent digestibility of total Se (ADSe). In the first experiment, from day (d) 0 to d21, Se sources were tested at different supplied levels and compared with an unsupplemented diet (NC). No significant effects were observed on growth performance during the experimental period. However, the different Se sources and levels improved muscle Se concentration compared with the NC, with a significant source effect in the following order: SS < SY < SO (P<0·05). Seleno-amino acids speciation results for NC, SY and SO at 0·3 mg Se/kg feed indicated that muscle Se was only present as SeMet or SeCys, showing a full conversion of Se by the bird. The second experiment (d0-d24) compared SS, SY or SO at 0·3 mg Se/kg feed. The ADSe measurements carried out between d20 and d23 were 24, 46 and 49% for SS, SY and SO, respectively, with significant differences between the organic and mineral Se sources (P<0·05). These results confirmed the higher bioavailability of organic Se sources compared with the mineral source and demonstrated a significantly better efficiency of HMSeBA compared with SY for muscle Se enrichment.

背景与目标： ：在肉鸡上进行了两次实验，比较了一种新型有机硒源2-羟基-4-甲基硒代丁酸（HMSeBA; SO）与两种实用的硒添加剂亚硒酸钠（SS）和硒酵母（SY）的效果。比较了不同硒源的相对生物利用度，分别针对肌肉（主要胸大肌）总硒，硒代蛋氨酸（SeMet）和硒代半胱氨酸（SeCys）浓度以及总硒（ADSe）的表观消化率。在第一个实验中，从（d）0天到d21天，以不同的供应水平测试了硒源，并将其与不补充饮食（NC）进行了比较。在实验期间，未观察到对生长性能的显着影响。然而，与NC相比，不同的硒来源和水平提高了肌肉硒浓度，其显着的来源效应按以下顺序：SS

BACKGROUND & AIMS: :Selenium (Se) has anti-inflammatory and antioxidant properties and is necessary for the development and normal function of the central nervous system. This study was aimed to compare the in vitro effects of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C21H2HOSe; organoselenium) and sodium selenate (inorganic Se) on adenosine deaminase (ADA) activity, cell viability, lipid peroxidation, scavenger of nitric oxide (NO) and nonprotein thiols (NP-SH) content in the cerebral cortex slices of the young rats. A decrease in ADA activity was observed when the slices were exposed to organoselenium at the concentrations of 1, 10 and 30 µM. The same compound showed higher scavenger capacity of NO than the inorganic compound. Inorganic Se was able to protect against sodium nitroprusside-induced oxidative damage and increased the NP-SH content. Both the compounds displayed distinctive antioxidant capacities and were not cytotoxic for the cerebral cortex slices in the conditions tested. These findings are likely to be related to immunomodulatory and antioxidant properties of this compound.

背景与目标： 硒（Se）具有抗炎和抗氧化作用，是中枢神经系统发育和正常功能所必需的。这项研究旨在比较3-甲基-1-苯基-2-（苯基硒代）辛-2-烯-1-酮（C21H2HOSe;有机硒）和硒酸钠（无机硒）对腺苷脱氨酶（ADA）的体外作用幼鼠大脑皮质切片中的活性，细胞活力，脂质过氧化，一氧化氮（NO）和非蛋白硫醇（NP-SH）含量的清除剂。当切片以1、10和30 µM的浓度暴露于有机硒时，观察到ADA活性降低。相同的化合物显示出比无机化合物更高的NO清除能力。无机硒能够防止硝普钠引起的氧化损伤并增加NP-SH含量。在测试条件下，这两种化合物均显示出独特的抗氧化能力，并且对大脑皮层切片没有细胞毒性。这些发现可能与该化合物的免疫调节和抗氧化特性有关。

BACKGROUND & AIMS: :This study determined the selenium (Se) bioavailability from Se-enriched garlic and cabbage using broiler chickens. Se-enriched garlic (18.5 mg of Se/kg) and cabbage (101.5 mg of Se/kg) were produced by soil enrichment using selenate. Conventional and Se-enriched garlic and cabbage were dried, ground, and added to broiler chick diets. Ninety-six broiler chickens at 1 day of age were assigned to four dietary treatments: NC (cabbage + garlic), PC (cabbage + garlic + selenomethionine, 0.5 mg of Se/kg of diet), GS (cabbage + Se-enriched garlic, 0.5 mg of Se/kg of diet), and CS (garlic + Se-enriched cabbage, 0.5 mg of Se/kg of diet), with six replicates per treatment and four birds per cage. Birds were fed the experimental diets for 4 weeks and slaughtered to obtain blood and tissues: white (breast) muscle, dark (thigh) muscle, liver, and feathers. All excreta were collected weekly, dried, and ground for Se analysis. Bird weight gain and feed intake were measured weekly. Total Se content and glutathione peroxidase (GPX) activity in liver and plasma were measured. Total liver Se content of the PC birds (0.876 mg of Se/kg) was the highest (P < .05). The CS (0.693 mg of Se/kg) and GS (0.627 mg of Se/kg) birds had higher (P < .05) total liver Se than the NC birds (0.514 mg of Se/kg). Plasma GPX activity of the PC birds was highest (P < .05), and that of CS and GS birds was higher (P < .05) than the NC birds. Liver GPX activity of the PC birds was higher (P < .05) than all other treatments. Bioavailability of Se to broiler chickens was not different (P > .05) among PC (65.2%), CS (61.2%), and GS (70.7%) birds. This study indicates that the Se from Se-enriched garlic and cabbage is highly bioavailable and can potentially be beneficial in enhancing Se status and GPX activity.

背景与目标： ：本研究使用肉鸡确定了富硒大蒜和卷心菜中硒的生物利用度。通过使用硒酸盐进行土壤富集，可以生产出富硒的大蒜（Se的含量为18.5 mg / kg）和卷心菜（Se的含量为101.5 mg / kg）。将常规的和富硒的大蒜和白菜干燥，磨碎，然后添加到肉鸡的日粮中。 1日龄的96只肉鸡被分配到四种饮食疗法中：NC（白菜大蒜），PC（白菜大蒜硒蛋氨酸，0.5 mg Se / kg饮食），GS（白菜中富含Se的大蒜，0.5 mg硒/千克日粮）和CS（大蒜富硒卷心菜，0.5毫克硒/千克日粮），每次处理重复六次，每笼饲养四只鸡。给鸟类喂食4周的实验饮食，并宰杀以获取血液和组织：白（乳房）肌肉，黑（大腿）肌肉，肝脏和羽毛。每周收集所有排泄物，干燥并研磨以进行Se分析。每周测量家禽体重增加和采食量。测量肝脏和血浆中的总硒含量和谷胱甘肽过氧化物酶（GPX）活性。 PC禽的总肝硒含量最高（Se / kg为0.876 mg）（P <0.05）。 CS（0.693 mg Se / kg）和GS（0.627 mg Se / kg）禽类的总肝Se含量高于NC禽类（0.514 mg Se / kg）（P <.05）。 PC鸟的血浆GPX活性最高（P <.05），CS和GS鸟的血浆GPX活性高于NC鸟（P <.05）。 PC禽的肝GPX活性高于所有其他处理（P <.05）。在PC（65.2％），CS（61.2％）和GS（70.7％）禽类中，硒对肉鸡的生物利用度没有差异（P> .05）。这项研究表明，富硒大蒜和卷心菜中的硒具有很高的生物利用度，并且可能在提高硒状态和GPX活性方面具有潜在的益处。

BACKGROUND & AIMS: :For determination of selenium (Se) in biological materials, an improved method based on high performance liquid chromatographic determination of the fluorophore formed by reaction of selenite with 2,3-diaminonapththalene was developed. The concentration detection limits were 0.5 ng/g in dried materials and 0.03 ng/mL in fluid materials. In quadruplicate assays of 11 biological reference materials using the proposed method, measured Se concentrations were not significantly different from their certified values. Thus, the proposed method is reliable and suitable for the determination of trace levels of Se in foods. Using the proposed method, Se concentrations in various kinds of tea were determined to assess the contribution of tea to daily Se intake in the Japanese population. Se concentration in the leaves of general black, green and oolong tea obtained in local retail stores was 33 +/- 19 ng/g (n=440). The leaves of a particular Chinese green tea sold under the name "high Se tea" were found to contain 455 +/- 184 ng/g (n= 14) of Se. While the percentage of Se extractable by infusion was less than 5% for the general teas, that in the high Se tea was more than 20%. These results indicated that intake of tea does not contribute to daily Se intake in the Japanese population. However, since infusions from high Se tea contained over 5 ng/mL of Se, consumption of over 1 L/d of tea derived from such high Se teas may increase the daily Se intake by close to 10%.

背景与目标： ：为了测定生物材料中的硒，开发了一种改进的方法，该方法基于高效液相色谱法测定亚硒酸盐与2,3-二胺基萘的反应形成的荧光团。干燥物质的浓度检测极限为0.5 ng / g，流体物质的浓度检测极限为0.03 ng / mL。使用所提出的方法对11种生物参考物质进行一式四份测定时，测得的硒浓度与它们的认证值无显着差异。因此，所提出的方法是可靠的并且适用于食品中痕量硒的测定。使用所提出的方法，确定了各种茶中的硒含量，以评估茶对日本人口每日硒摄入量的贡献。在当地零售商店中获得的普通红茶，绿茶和乌龙茶中的硒含量为33 /-19 ng / g（n = 440）。发现以“高硒茶”的名称出售的特定中国绿茶的叶子含有455 /-184 ng / g（n = 14）的硒。虽然普通茶可通过浸提提取的硒含量少于5％，但高硒茶的硒含量却超过20％。这些结果表明，茶的摄入量对日本人口的每日硒摄入量没有贡献。但是，由于从高硒茶中注入的硒含量超过5 ng / mL，因此从这种高硒茶中提取的茶量超过1 L / d可能会使每天的硒摄入量增加近10％。

BACKGROUND & AIMS: :Ageing is an inevitable biological process with gradual and spontaneous biochemical and physiological changes and increased susceptibility to diseases. Some nutritional factors (zinc, niacin, selenium) may remodel these changes leading to a possible escaping of diseases, with the consequence of healthy ageing, because they are involved in improving immune functions, metabolic homeostasis and antioxidant defence. Experiments performed "in vitro" (human lymphocytes exposed to endotoxins) and "in vivo" (old mice or young mice with low zinc dietary intake) show that zinc is important for immune efficiency (both innate and adaptive), metabolic homeostasis (energy utilization and hormone turnover) and antioxidant activity (SOD enzyme). Niacin is a precursor of NAD+, the substrate for the activity of DNA repair enzyme PARP-1 and, consequently, may contribute to maintaining genomic stability. Selenium provokes zinc release by Metallothioneins (MT), via reduction of glutathione peroxidase. This fact is crucial in ageing because high MT may be unable to release zinc with subsequent low intracellular free zinc ion availability for immune efficiency, metabolic harmony and antioxidant activity. Taking into account the existence of zinc transporters (ZnT and ZIP family) for cellular zinc efflux and influx, respectively, the association between zinc transporters and MT is crucial in maintaining satisfactory intracellular zinc homeostasis in ageing. Improved immune performance, metabolic homeostasis, antioxidant defence occur in elderly after physiological zinc supplementation, which also induces prolonged survival in old, nude and neonatal thymectomized mice. The association "zinc plus selenium" improves humoral immunity in old subjects after influenza vaccination. The association "zinc plus niacin" in elderly is actually in progress.

背景与目标： ：衰老是不可避免的生物学过程，具有逐渐而自然的生化和生理变化以及对疾病的易感性。一些营养因素（锌，烟酸，硒）可能会重塑这些变化，从而导致疾病的逃逸，并导致健康衰老，因为它们参与改善免疫功能，代谢稳态和抗氧化防御。 “体外”（暴露于内毒素的人淋巴细胞）和“体内”（低锌饮食的老年小鼠或年轻小鼠）进行的实验表明，锌对于免疫效率（先天和适应性），代谢稳态（能量利用）都非常重要。和激素转换）和抗氧化活性（SOD酶）。烟酸是NAD的前体，NAD是DNA修复酶PARP-1活性的底物，因此可能有助于维持基因组稳定性。硒可通过还原谷胱甘肽过氧化物酶来激发金属硫蛋白（MT）释放锌。这一事实对于衰老至关重要，因为高MT可能无法释放锌，随后细胞内游离锌离子的利用率较低，从而提高了免疫效率，代谢和谐和抗氧化剂活性。考虑到锌转运蛋白（ZnT和ZIP家族）分别存在于细胞锌外流和内流中，锌转运蛋白和MT之间的联系对于维持衰老过程中令人满意的细胞内锌稳态至关重要。补充生理锌后，老年人的免疫力，代谢稳态，抗氧化防御能力得到改善，这也可导致经去胸腺切除的老年，裸鼠和新生小鼠的存活时间延长。流感疫苗接种后，“锌加硒”协会提高了老年受试者的体液免疫力。老年人中的“锌加烟酸”协会实际上正在进行中。