肺癌患者血清硒含量的测定及临床意义

测定４０例肺癌患者的血清硒水平，并与健康对照组比较。结果表明，肺癌患者血清硒水平显著低于健康对照组，肺癌患者不同病期及病理类型间血清硒含量无统计学差异。揭示与其他很多肿瘤一样，肺癌患者血清硒水平显著降低，但不可作为判断病期及预测有无转移的指标。硒水平亦与病理类型无关。     

口腔颌面恶性肿瘤患者血清硒,NK细胞活性检测的临床意义及评价

用气相色谱法及四甲基偶氮唑蓝法（ＭＴＴ）对３７例口腔颌面恶性肿瘤初发患者进行手术前后血清硒及外用血ＮＫ细胞活性检测，并以健康人群作对照，结果发现肿瘤患者血硒及ＮＫ细胞活性均显著低于正常水平，并且随着病情进展有进一步降低趋势；治疗（手术）后血硒及ＮＫ细胞活性则明显升高。由此认为对患者进行血硒、ＮＫ细胞活性检测可作为口腔恶性肿瘤的辅助诊断指标之一，并为判断疗效及预后提供参考。同时通过对血硒与免疫应答关系的探讨，认为将硒及ＮＫ细胞运用于肿瘤的防治中具有广阔前景。     

肝病患者血硒水平与甲胎蛋白浓度的相关性研究

硒是人体不可缺少的一种微量元素,其水平的高低影响着机体的肿瘤免疫反应,甲胎蛋白是癌胚蛋白,其浓度的高低反映了肝脏损害的程度（除胎儿期外）,本文血硒水平与甲胎蛋白浓度相关性研究结果表明,两者呈负相关（相关系数－0．627）,且血硒水平呈现慢乙肝＞肝硬化＞肝癌,提示硒对肝脏具有一定的潜在保护作用,补硒可以预防肝癌,在肝癌治疗中适量补硒,对增强患者免疫功能,延长生存期有着十分重要的临床意义。     

微量元素硒与人体健康

综述了硒与人体健康的关系,包括：硒与心血管疾病、硒与肿瘤、硒与抗衰老、硒与免疫、硒与肝炎等的关系。     

硒与癌症

硒是人体必需微量元素。流行病学调查表明。土壤硒含量，谷物硒含量。食物硒摄入量及人体血硒水平与多种癌症发病率（死亡率）呈负相关，动物实验证实，适量硒具有抑癌抗癌作用，硒抗癌机理研究及人体干预试验进一步说明硒与癌症关系密切。     

微量元素硒的临床应用和研究

简述了近年来硒的临床应用和研究概况，主要内容涉及到硒在抗衰老，治疗病毒性肝炎和肿瘤中的应用以及硒的补充。     

硫代硫酸钠容量法测定电解锰厂废水中的微量硒

硒是人体必需的微量元素,对人体健康有着重要的影响,硒含量过高或过低都会引起疾病。同时,硒是多种人体酶中不可少的元素,流行病学研究表明,克山病、某些肿瘤的发病率与人体血硒水平呈显著负相关系,艾滋病(ADIS)患者血硒水平明显低于正常人群。湘西自治洲锰矿产量居全世界第二位,并且每生产1t电解锰,废渣为8～10t,污水为300t,未经任何处理直接排放于河中,为此,必须对废水中     

微量元素对老年人健康的作用与危害

介绍了微量元素的生理功能，微量元素与衰老，长寿和老年人冠心病，高血压，脑血管疾病，肿瘤，糖尿病等五种常见病的关系。还特别介绍了锌对人类健康的作用和铅对人类健康的危害。老年人体内有益的微量元素，如铁，锌，锰，铬，硒等比较缺乏，相反镍，铅，铝等有害的微量元素比较高。长寿老人头发中有益微量元素锰，钴，硒，铜，锌，铬等均有较高水平。人要长寿，必须维持体内微量元素的水平，微量元素过低或者过高应及时通过食疗或药物治疗进行调节。     

54例白血病患者血清硒含量分析

以催化极谱法测定了５４例白血病患者血清硒含量。结果表明，急淋、急粒患者血清硒含量均低于正常对照组，慢粒及急、慢粒经治疗缓解者血清硒含量与正常对照组间均无显著性差异，提示低硒状态只存在于急性患者，且随病情缓解后血硒水平趋于正常，慢粒与血硒含量没有明显的相关关系。     

硒与甲状腺疾病

简要介绍了硒的代谢、功能及其与甲状腺的生理，重点综述了硒在几种常见甲状腺疾病中的表达水平，并探讨了硒对甲状腺疾病的作用机制。     

The Application on Determination of Se by Continus Flow Hydride Generation Atomic Absorption Spectrometry in Zhangjiakou Low Se Area of China

Selenium is an essential nutrient trace element for human with established recommended dietary intake levels for different age groups. Low Se status has been reported to be a contributing factor in a number of deficiency diseases, of which the best doucumented is Keshan disease, a cardiomyopathy occurring in certain regions of China. By now,there are still new Keshan disease patients occuring in some area of China such as Zhangjiakou district. In order to assess and monitor the selenium nutrient status in human health, it is necessary to precisely quantify selenium in environment materials especially low Se level materials. This paper reports the analysis method on determination Se in low Se grain samples by continuous flow hydride generation atomic absorption spectrometry (HGAAS).     

补充富硒小麦和富硒玉米对大鼠血硒状态影响的对比观察

给克山病病区粮喂养６周的大鼠补充富硒小麦或富硒玉米,观察了大鼠血硒和血ＣＳＨ－Ｐｘ活性的变化。结果显示,补充富硒小麦和富硒玉米均可有效地升高大鼠血浆硒、红细胞硒和红细胞ＧＳＰ－Ｐｘ活性,且两种形式硒的作用效果相同;停止补硒后,补充富硒小麦组大鼠的红细胞和红细胞ＧＳＨ－Ｐｘ活性均显著高于补充富硒玉米组大鼠。表明给大鼠补充富硒小麦较补充富硒玉米好。     

Selenium speciation determines the angiogenesis effect through regulating selenoproteins to trigger ROS-mediated cell apoptosis and cell cycle arrest

Tumor angiogenesis is closely related to tumor development, immune escape, and drug resistance. Therefore, the development of effective anti-tumor angiogenesis drugs is of great research significance. Although the current clinical angiogenesis inhibitors have achieved certain efficacy, they also pose the problems of limited and short duration of efficacy, drug resistance, and intrinsic toxicity. Anti-tumor angiogenesis strategies targeting endothelial cells (ECs) have attracted widespread attention in the development of highly effective and low toxicity anti-angiogenesis inhibitors. Studies have verified that the trace element selenium (Se) can inhibit tumor growth by inhibiting tumor angiogenesis through different mechanisms. Nevertheless, it is unclear whether Se speciation has different effects on anti-tumor angiogenesis. Herein, we found that Se exhibited effective anti-angiogenic activity, and its mechanisms of activity were determined by its chemical speciation. Organic Se can significantly inhibit tumor angiogenesis by targeting thioredoxin reductase (TrxR) to trigger cell apoptosis and cell cycle arrest and by increasing reactive oxygen species (ROS) production in ECs. Inorganic Se can induce cell cycle arrest and increase ROS production in ECs, showing promising anti-angiogenic effects. Se nanoparticles (SeNPs) slightly inhibit tumor angiogenesis by inducing apoptosis and cell cycle arrest and by increasing the production of ROS. In summary, this study elucidates the anti-angiogenic activity of Se speciation control with a view to providing a scientific reference for the design and development of novel Se-based highly effective and low toxicity angiogenesis inhibitors.     

Preliminary Study on the Changes of IgA/VcA Titers in Low Blood Selenium Persons1 Sera by Oral use of Selenium-Enriched Yeast

Abstract

Whole blood selenium (Se) concentrations in 112 IgA/VcA positive and 33 oral administrating Se—enriched yeast subjects and 32 IgA/VcA negative ones were determined, using 2,3—diaminonaphahalene fluorometric method modified by the author. The blood Se levels ([xbar] ± SD) of IgA/VcA positive and negative subjects were 0.115 ± 0.024, 0.118 ± 0.028 μg/ml. respectively, no significant difference was existed between their blood Se levels (P > 0.20). The blood Se levels of low blood Se subjects with IgA/VcA positivity were 0.104 ± 0.009, 0.149 ± 0.033 μg/ml, respectively, before and after oral use of Se—enriched yeast, there were significant differences between their blood Se levels (P < 0.001). However, the efficiency of Se—enriched yeast on the negative change of IgA/VcA titer was only 21.4%. It suggested that blood Se levels are not related with IgA/VcA titers.     

Synchrotron X-ray 2D and 3D elemental imaging of CdSe/ZnS quantum dot nanoparticles in Daphnia magna

The potential toxicity of nanoparticles to aquatic organisms is of interest given that increased commercialization will inevitably lead to some instances of inadvertent environmental exposures. Cadmium selenide quantum dots (QDs) capped with zinc sulfide are used in the semiconductor industry and in cellular imaging. Their small size (<10 nm) suggests that they may be readily assimilated by exposed organisms. We exposed Daphnia magna to both red and green QDs and used synchrotron X-ray fluorescence to study the distribution of Zn and Se in the organism over a time period of 36 h. The QDs appeared to be confined to the gut, and there was no evidence of further assimilation into the organism. Zinc and Se fluorescence signals were highly correlated, suggesting that the QDs had not dissolved to any extent. There was no apparent difference between red or green QDs, i.e., there was no effect of QD size. 3D tomography confirmed that the QDs were exclusively in the gut area of the organism. It is possible that the QDs aggregated and were therefore too large to cross the gut wall.     

Sensitivities of selenite, selenate, selenomethionine and trimethylselenonium ion in aqueous solution and in blood plasma-ETAAS compared with ICP-MS

Aqueous solutions and blood plasma spiked with selenite (Se(IV)), selenate (Se(VI)), selenomethionine (SeMet) or trimethylselenonium (TMSe) iodide were analyzed by Zeeman-corrected electrothermal atomic absorption spectrometry (ETAAS) using palladium as a chemical modifier, and by inductively coupled plasma mass spectrometry (ICP-MS). Using ETAAS, the sensitivities for Se(IV), SeMet and TMSe in aqueous solution were similar, whereas the sensitivity of Se(VI) was 63% of that value. In blood plasma, the ETAAS sensitivities of Se(IV) and Se(VI) were equal, whereas the sensitivities of SeMet and TMSe were 87 and 56%, respectively, of that value. In contrast, the ICP-MS sensitivities obtained for Se(VI), TMSe and SeMet were between 96 and 98% of that obtained for Se(IV) in aqueous solution and in blood plasma. It is concluded, that ICP-MS is superior to ETAAS as the problem of differences in sensitivity of the selenium species when using ETAAS are not prevalent when using the ICP-MS technique.     

低硒对大鼠血管一氧化氮合酶和微循环的影响

采用低硒饲料饲养大鼠造成体内贫硒。１４周时测定血浆中脂质过氧化物（ＬＰＯ）、前列环素（ＰＧＩ２）和血栓素（ＴＸＡ２）的水平以及部分血液流变学指标。实验第３９周,测定血管组织一氧化氮合酶（ＮＯＳ）活性及一氧化氮（ＮＯ）水平。结果显示,低硒饲料组的血管ＮＯＳ活性、ＮＯ水平显著低于常规饲料的对照组;而在实验第１４周时,当低硒饲料组的血硒、血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性显著下降、血浆ＬＰＯ水平明显上升的同时,其对应的血浆６－酮－ＰＧＦ１α水平也显著降低,但其ＴＸＢ２与对照组无显著差异。此外,随着大鼠体内的贫硒,其红细胞变形能力下降,但红细胞聚集指数和血沉方程Ｋ值提高。因此,硒不足可能会通过影响ＮＯＳ活性和ＰＧＩ２的合成以及红细胞特性而损害微循环功能。     

Effect of selenium supplementation on thyroid antibodies

Selenium is an essential component of selenoproteins, enzymes with extensive regulatory and protective effect in organism. Immunological effects of Se are documented and are distinct even above concentrations necessary for maximal activity of selenoenzymes. Therefore, we investigated effect of supplementation by 100 μg of yeast-bound Se on concentrations of thyroid autoantibodies TPOAb and TgAb in the group of 253 seniors living in the Asylum Houses of South Bohemia. Increase of serum selenium from 59 to 150 μg Se/L serum in supplemented group and from 59 to 72 μg Se/L serum in group with placebo were detected by Instrumental Neutron Activation Analysis (INAA) and proved increased Se intake during the trial. Autoantibodies were analyzed by ELISA at the beginning of the trial and after 1 year. Statistical evaluation of results in whole groups (regardless of increased autoantibodies) by ANOVA manifested significant decrease of TPOAb and TgAb in non-supplemented group while supplementation did not effect serum autoantibodies concentrations. Evaluation of groups of seniors created from those with increased autoantibodies, ANOVA demonstrated decrease of TPOAb in both groups but Se supplementation did not affect the decrease. In opposite, TgAb increased significantly and Se supplementation led to higher increase of TgAb. Recent results of possibility to decrease serum concentration of TPOAb proved this effect only for high TPOAb concentrations and for higher Se supplements. From this point of view, it is necessary to conduct subsequent trials with the patients with autoimmune thyreoiditis with different levels of autoantibodies and detect also serum Se levels.     

Selenium bioaccessibility assessment in selenized yeast after "in vitro" gastrointestinal digestion using two-dimensional chromatography and mass spectrometry

In order to investigate the potentially bioavailable selenium-containing compounds in the selenized yeast candidate reference material SEAS 6, a two-dimensional (size exclusion-reversed phase) chromatography approach has been worked out. Electrospray tandem mass spectrometry (ESI Q-TOF MS) was then used for off-line identification of low molecular weigh selenocompounds generated during the gastrointestinal digestion. Selenomethionine (SeMet) was the major compound identified in the gastrointestinal extract while SeMet selenoxide was its main degradation product formed after medium and long-term sample storage, respectively. Total Se and SeMet were quantified in both the soluble extracts and the residue. Results showed that 89+/-3% of total Se was extracted after gastrointestinal digestion, but only 34+/-1% was surprisingly quantified as free SeMet. The rest of Se was present as many other low, medium and high molecular weight Se-species, which could be detected and further characterized by using the two-dimensional chromatography approach proposed here. Interestingly, most of Se-species seemed to be Se-peptides unspecifically produced by the gastrointestinal juice. These results show for the first time that while the efficiency of human gastrointestinal digestion to dissolve Se-containing proteins present in yeast may be high, its efficiency to convert them into free SeMet is much lower. Se-species present in the insoluble residue (not assimilated by the organism), accounting for 11+/-1% of the total Se in selenized yeast, were also studied. After treatment with SDS (denaturing agent) only 13+/-2% of this "insoluble" Se was solubilized, indicating that it was mainly non-protein bound and likely associated to other insoluble matrix components.