重要的保健元素--硒(之一)

硒的保健作用 硒作为一种微量元素是在1817年才被Berzhus发现并命名的。硒是人体必需微量元素之一,是一种强抗氧化剂,其作用与维生素E相似,但效力更大。硒可用于调节体内氧化还原反应的速度,影响某些重要酶的代谢及活性,调节维生素A、C、E、K在体内     

食品中硒测定方法的改进

硒是人与动物生长中必需的微量元素之一,硒能调节氧化还原反应速度,强化某些酶系的活性,调节维生素A、C、E、K在体内的吸收和消耗.     

硒与糖尿病关系的研究简介

硒缺乏可以导致人体免疫能力下降,医学研究表明,糖尿病患者体内普遍缺硒,若补充硒可以增加糖尿病患者免疫力。对微量元素硒与糖尿病相关性的研究进行介绍。     

山西太原地区部分正常人群与肿瘤患者维生素营养状况分析

目的 探讨太原地区部分正常人群与恶性肿瘤住院患者9种维生素营养状况的差异，为合理补充维生素提供参考。方法 本实验的受试者分为肿瘤组和正常人群组，共855人。肿瘤组人群选择在我院肿瘤科的住院患者，正常组人群选择18~70岁经体格检查、实验室检验和肿瘤系列检测后均未见异常的人群。所有受试者在知情同意后，采用基线问卷调查以及抽取空腹静脉血检测。采用两独立样本比较的t检验、单因素方差分析及Dunnett t检验分析两组维生素水平的差异。结果 肿瘤组和正常人群组的血清维生素A（平均值:肿瘤组0.47±0.33，正常组0.87±0.15,单位:μmol /L）、维生素B1（平均值:肿瘤组69.68±12.60，正常组80.35±23.42，单位:nmol /L）、维生素B6（平均值:肿瘤组26.82±8.43，正常组46.41±12.43，单位:nmol /L）和维生素C（平均值:肿瘤组28.00±7.90，正常组30.82±5.11，单位:μmol /L）水平的差异具有统计学意义(P＜0.0001)；在不同病理分型的恶性肿瘤中，无论是哪一种病理分型的患者，其维生素A、维生素B1、维生素B6、维生素B9和维生素C水平均低于正常人群组的维生素水平P＜0.0001；胃部恶性肿瘤、泌尿系统肿瘤、乳腺肿瘤、食管恶性肿瘤、泌尿系统肿瘤和生殖系统肿瘤患者的不同维生素水平与正常人群组相比水平偏低P＜0.05。结论 肿瘤患者和正常人群的血清维生素水平有差异，而不同病理分型的恶性肿瘤患者存在不同种类的维生素缺乏。     

黑龙江省肿瘤病人血清硒水平研究

近年来微量元素的研究在许多领域获得突破性进展,特别是微量元素硒与医药学、生命、健康和疾病的关系至关重要。一些研究指出,硒可以预防和抑制肿瘤的发生和发展,缺乏硒时,可以促进癌症的发生和发展,补充硒之后便可抑制癌症。为探素微量元素硒与肿瘤的关系,初步测定胃癌、大肠癌、肺癌患者与对照组血清硒水平,为研究硒与肿瘤的关系提供依据。1 材料和方法选择因患胃癌、大肠癌和肺癌而入黑龙江省肿瘤医院、黑龙江医院和哈尔滨医科大学附     

维生素C对低硒高镉饲料饲养大鼠肝细胞电生理的影响

硒参与机体的许多生理过程，是人体必需的微量元素，研究表明，缺硒可以导致心脏、肝脏、关节等机体许多部位的严重病患。但近年的研究进一步表明：单纯低硒并不能致上述疾病，机体脏器的损害可能与环境因素特别是食物中其它物质含量的异常也密切相关，其中，高镉低维生素C可能是十分重要的协同因素。本研究以Wistar大鼠为对象，采用低硒高镉及低硒高镉伴高维生素C饲料饲养建立实验动物模型，以细胞内微电极技术观察低硒、高镉及维生素C对大鼠肝细胞电生理的协同影响，为进一步阐明食物中微量元素及维生素C含量异常致肝细胞损害的机理提供实验依据。     

糖病患者宜喝麦芽茶

糖尿病患者有时为控制血糖而限制饮食,殊不知这样会因缺乏微量元素铬、硒及B族维生素等,使病情加重。其中,铬元素参与体内的糖成分,可提高人体对胰岛素的敏感性;硒是构成谷胱甘肽过氧化酶的活性成分,能防止胰岛B细胞氧化破坏．降低血糖和尿糖,防止糖尿病眼病的发生;B族维生素可减少糖尿病末梢神经病变。麦芽（一般药店有售）是大麦经水浸泡长出幼芽后干燥而成．富含铬、硒及B族维生素。喝麦芽茶对控制血糖有明显作用。     

妇科肿瘤治疗中硒的应用

在人体最重要的内源性抗氧化系统中,必需微量元素硒是一种关键的辅助因子。有关的研究主要集中在下列方面:正常组织的辐射防护,恶性肿瘤的射线增敏,消水肿药效,硒的预测效果,初期和续发癌症的预防效果。进一步探讨微量元素硒在妇科肿瘤中的应用。     

膳食中维生素E对克山病区粮饲养的大鼠硒代谢的影响

用除去维生素E的克山病病区粮配成的基础饲料,利用在该低硒低维生素E的基础饲料中补充α-生育酚和/或硒的饲料饲养大鼠,观察维生素E对硒代谢的影响。结果表明: (1)饲料硒水平相同时,维生素E可使肝组织中硒水平明显升高,对其它组织影响不大。 (2)不论硒缺乏时或是补充硒时,维生素E缺乏组动物的全血、心和肝谷胱甘肽过氧化物酶活力均低于补充维生素E组。心和肝中的差异较为明显。 (3)当相应两组大鼠的硒摄入量无明显差别时,不论是补硒组或是缺硒组,在饲料中补充维生素E均可使尿硒排出明显降低,硒在体内存留率增高。     

硒——神奇的护肝元素

在古希腊语中,硒（Selenium）是“月亮女神”的意思。第二次世界大战期间,许多人由于营养缺乏患上了严重的肝病。营养学家施瓦茨教授研究发现,蛋白质缺乏是引起这种肝脏坏死的主要原因,而补充硒具有明显的保肝作用,疗效优于含硫氨基酸和维生素E等,证明硒是人体必需的一种微量元素。     

微量元素硒预防和治疗肿瘤研究新进展

大量研究表明 ,微量元素硒不仅可直接抑制某些肿瘤的生长 ,而且具有拮抗和缓解诱变剂、致癌剂对机体的致癌作用 ,对癌前病变有阻断作用 ,并能缓解癌症患者化疗过程中的毒副作用。因此 ,微量元素硒在肿瘤的预防和治疗中具有极其重要的作用。     

微量元素硒与婴幼儿佝偻病的关系探讨

目的 为了了解婴幼我佝偻病的硒营养状况。方法 婴幼儿佝偻病和正常对照组进行微量元素硒的测定。结果 佝偻病的婴幼儿和正常的婴幼儿血硒存在显著性差异。结论 婴幼儿佝偻病缺硒，因而可能影响机体的免疫能力。     

提高接触粉尘工人抗超氧阴离子(O-*2)功能的研究——人体对生产性粉尘免疫反应系列研究之二

目的　探讨提高接触粉尘工人体内抗超氧阴离子 (O-·2 )能力的方法 ,为寻找尘肺早期诊断的辅助指标及开壁治疗新途径提供依据。方法　检测接尘作业工人血液中超氧化物歧化酶 (SOD)及微量元素 (Cu、Zn、Mn)的含量 ,并对SOD含量下降工人进行治疗观察。结果　检测结果表明 ,接触碳素粉尘及碳黑粉尘工人血液中微量元素铜锌含量有不同程度下降 ,其中锌含量下降较明显 ;接尘工人血液中SOD含量下降 ,其下降幅度与接尘工龄相关不明显 ;接尘工人血液中SOD含量下降者经治疗后有明显提高 (2 4 2 %～ 5 3 3 % )。结论　接尘工人经用微量元素及清除自由基的药物治疗后 ,SOD含量有明显提高 ,为此 ,建议定期给接尘工人补充微量元素 (Cu、Zn)及维生素C、E ,提高他们抗超氧阴离子功能     

胃癌患者肿瘤组织中锌 铜 铁 硒含量分析

为了解微量元素与胃癌的关系 ,对 2 0例胃癌患者切除的肿瘤组织进行Zn、Cu、Fe、Se分析 ,以 2 4例非胃癌患者胃组织为对照。结果 :胃癌患者肿瘤组织中Zn、Fe含量明显低于对照组 (P <0 .0 1) ,而Cu、Se含量与对照组无明显差异 ,但Cu/Zn比值观察组明显高于对照组。揭示了胃癌的发生与体内微量元素有关     

Selenium in cancer prevention: a review of the evidence and mechanism of action

Se is an unusual trace element in having its own codon in mRNA that specifies its insertion into selenoproteins as selenocysteine (SeCys), by means of a mechanism requiring a large SeCys-insertion complex. This exacting insertion machinery for selenoprotein production has implications for the Se requirements for cancer prevention. If Se may protect against cancer, an adequate intake of Se is desirable. However, the level of intake in Europe and some parts of the world is not adequate for full expression of protective selenoproteins. The evidence for Se as a cancer preventive agent includes that from geographic, animal, prospective and intervention studies. Newly-published prospective studies on oesophageal, gastric-cardia and lung cancer have reinforced previous evidence, which is particularly strong for prostate cancer. Interventions with Se have shown benefit in reducing the risk of cancer incidence and mortality in all cancers combined, and specifically in liver, prostate, colo-rectal and lung cancers. The effect seems to be strongest in those individuals with the lowest Se status. As the level of Se that appears to be required for optimal effect is higher than that previously understood to be required to maximise the activity of selenoenzymes, the question has been raised as to whether selenoproteins are involved in the anti-cancer process. However, recent evidence showing an association between Se, reduction of DNA damage and oxidative stress together with data showing an effect of selenoprotein genotype on cancer risk implies that selenoproteins are indeed implicated. The likelihood of simultaneous and consecutive effects at different cancer stages still allows an important role for anti-cancer Se metabolites such as methyl selenol formed from gamma-glutamyl-selenomethyl-SeCys and selenomethyl-SeCys, components identified in certain plants and Se-enriched yeast that have anti-cancer effects. There is some evidence that Se may affect not only cancer risk but also progression and metastasis. Current primary and secondary prevention trials of Se are underway in the USA, including the Selenium and Vitamin E Cancer Prevention Trial (SELECT) relating to prostate cancer, although a large European trial is still desirable given the likelihood of a stronger effect in populations of lower Se status.     

糖尿病大鼠心肌胰岛素含量与硒和维生素E的关系

探讨糖尿病（ＤＭ）大鼠心肌胰岛素含量变化与Ｓｅ和维生素Ｅ（ＶＥ）之间的关系。方法：应用低Ｓｅ复加注射链脲佐菌素（ＳＴＺ）制造ＤＭ模型,结合放免分析技术检测血清与心肌胰岛素含量。结果：低Ｓｅ、低ＶＥＤＭ大鼠心肌胰岛素含量明显减少,单纯补Ｓｅ或ＶＥ对心肌胰岛素含量的影响无统计学意义,而联合补Ｓｅ和ＶＥ则显著提高了ＤＭ大鼠心肌胰岛素水平。结论：ＤＭ时,Ｓｅ和ＶＥ所产生的联合生物学效应可以明显改善心肌细胞对胰岛素的摄取和利用,对改善ＤＭ时心肌细胞代谢与机能,防止ＤＭ心肌病变的发生发展可能起一定作用。     

维生素E和硒缺乏促进大鼠食管肿瘤发生及氧化应激机制的研究

目的探讨维生素E(VE)和硒(Se)营养缺乏对食管肿瘤发生的影响及其氧化应激机制。方法 110只雄性F344大鼠随机分为3组:VE/Se缺乏组,VE/Se正常组和溶剂对照组。VE/Se缺乏组和VE/Se正常组动物皮下注射N-甲基苄基亚硝胺(NMBzA)染毒,染毒剂量为0.35 mg/kg BW,每周3次,连续5周。溶剂对照组动物皮下注射等体积的20%二甲基亚砜(DMSO)。VE/Se缺乏组给予低VE/Se饲料(VE 46U/kg,Se 0.05mg/kg),VE/Se正常组、溶剂对照组给予正常饲料(VE 80U/kg,Se 0.15mg/kg)。在实验第25周解剖动物,进行食管肿瘤肉眼观察及病理检查。动物血浆VE水平采用高效液相色谱法检测,Se水平采用荧光法检测。食管组织中细胞增殖和DNA氧化损伤分别采用5-溴脱氧尿嘧啶(BrdU)和8羟基脱氧鸟苷(8-OH-dG)免疫组织化学法检测。动物血浆、食管及肝脏谷胱甘肽过氧化物酶(GPX)、谷胱甘肽转移酶(GST)活性采用试剂盒法检测。结果动物血浆VE和Se水平VE/Se缺乏组显著低于VE/Se正常组,VE/Se正常组略低于溶剂对照组。VE/Se缺乏组动物食管肉眼可见肿瘤发生率、平均肿瘤数量及病理损伤数量均显著高于VE/Se正常组(P<0.05);与VE/Se正常组相比,VE/Se缺乏组动物食管组织细胞增殖水平、8-OH-dG水平显著升高(P<0.05);动物血浆、食管及肝脏GPX和GST活性显著降低(P<0.05)。结论维生素E和硒缺乏能够加快细胞增殖,显著促进NMBzA诱发的大鼠食管肿瘤的发生,机体氧化应激、DNA氧化损伤在食管癌变过程中具有重要作用。     

The Use of Dietary Supplements to Alleviate Androgen Deprivation Therapy Side Effects during Prostate Cancer Treatment

Prostate cancer (PCa), the most commonly diagnosed cancer and second leading cause of male cancer death in Western societies, is typically androgen-dependent, a characteristic that underlies the rationale of androgen deprivation therapy (ADT). Approximately 90% of patients initially respond to ADT strategies, however many experience side effects including hot flashes, cardiotoxicity, metabolic and musculoskeletal alterations. This review summarizes pre-clinical and clinical studies investigating the ability of dietary supplements to alleviate adverse effects arising from ADT. In particular, we focus on herbal compounds, phytoestrogens, selenium (Se), fatty acids (FA), calcium, and Vitamins D and E. Indeed, there is some evidence that calcium and Vitamin D can prevent the development of osteoporosis during ADT. On the other hand, caution should be taken with the antioxidants Se and Vitamin E until the basis underlying their respective association with type 2 diabetes mellitus and PCa tumor development has been clarified. However, many other promising supplements have not yet been subjected large-scale clinical trials making it difficult to assess their efficacy. Given the demographic trend of increased PCa diagnoses and dependence on ADT as a major therapeutic strategy, further studies are required to objectively evaluate these supplements as adjuvant for PCa patients receiving ADT.     

Intravenous vitamin C as a chemotherapy agent: a report on clinical cases

A series of seven cases are presented in which intravenous vitamin C has been used as antineoplastic agent in the treatment of different types of cancers. The cancers cases reviewed are the following: Renal cell carcinoma (2), Colorectal cancer (1), Pancreatic cancer (1), Non-Hodgkin's lymphoma (2) and breast cancer (1). Toxic reactions were not observed at these high doses of intravenous Vitamin C. All patients were prescreened for Glucose 6--phosphate dehydrogenase deficiency before administering intravenous Vitamin C in order to prevent hemolysis.     

Evaluation of the microelement profile of Turkish hazelnut (Corylus avellana L.) varieties for human nutrition and health

In this study, the levels of boron (B), cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), lithium (Li), nickel (Ni), selenium (Se) and zinc (Zn) microelements in 16 hazelnut samples were determined by inductively coupled plasma mass spectrometry and atomic absorption spectroscopy after microwave digestion, and are discussed for human nutrition and health. Significant differences were observed between the microelement contents of the 16 varieties (P < 0.01). The average microelements concentrations in the varieties varied in the following ranges: B, 13.63-23.87; Co, 0.47-0.82; Cr, 0.22-0.52; Cu, 16.23-32.23; Fe, 31.60-51.60; Li, 0.035-0.042; Ni, 0.58-2.58; Se, 0.96-1.39; and Zn, 22.03-44.03 mg/kg. These results showed that hazelnuts can be an important microelement source for human nutrition and health. According to our trace element data, a daily consumption of 50 g hazelnut can supply easily about 6% for B, 9% for Co, 19% for Fe, 9% for Ni and 16% for Zn of the recommended daily allowance. On the other hand, Se, Cu and Cr levels of 50 g hazelnuts are higher than the respective daily requirements, but slight overdoses of these elements are non-toxic for human health.