硒与甲状腺功能

介绍了硒与甲状腺素的脱碘 ,硒缺乏和甲状腺素 ,甲状腺中硒、甲状腺素合成和氧化损伤 ,硒与病态甲状腺功能正常综合征的研究 ,简述了硒对甲状腺功能的影响     

机体免疫机能与微量元素硒关系的研究进展

硒是人体和动物必需的微量元素,近年来,微量元素硒与免疫功能的关系越来越受到人们的重视,硒能增强机体的免疫功能和对传染性疾病的抵抗能力.就硒对机体免疫功能的影响进行了阐述,并强调了科学补硒的重要性.     

适量补硒可有效防治甲状腺疾病

硒是人体必需微量元素．主要通过含硒蛋白发挥生物学作用。硒参与了多种生命活动的基本代谢过程,例如．DNA的合成过程需要含硒蛋白的参与。体内适宜的硒营养状况有利于维持正常的免疫防御功能、甲状腺功能、生殖功能等。研究证实．甲状腺在人体器官中含硒量最高．近年来的研究表明．硒对碘代谢和甲状腺功能主要有以下几方面重要影响.     

硒与太腺功能

介绍了硒与甲状腺素的脱碘,硒缺乏和甲状腺素,甲状腺中硒、甲状腺素合成和氧化损伤,硒与病态甲状腺功能正常综合征的研究,简述了硒对甲状腺功能的影响。     

缺硒大鼠模型的构建及其在认知功能中应用的研究进展

硒是人体必需微量元素,在维持细胞氧化还原平衡、免疫、发育、生殖健康、甲状腺激素代谢和认知功能等方面具有重要作用。大脑中硒的代谢机制与硒蛋白的功能得到深入研究,但缺硒与认知功能的关系以及硒对认知功能障碍的调控作用迄今尚无全面系统的总结。本文首次综述缺硒大鼠模型的构建方法及其在认知功能中的应用,以及硒在认知功能障碍中的应用进展,旨在为硒与认知功能的深入研究提供参考。     

富硒益生菌对小鼠免疫功能及抗氧化能力的影响

目的:研究富硒益生菌对小鼠免疫功能和抗氧化能力的影响。方法:100只昆明系小鼠,雌雄各半,随机均分为5组:对照组、亚硒酸钠组、富硒酵母组、富硒益生菌组和益生菌组,每天分别灌胃(ig)蒸馏水、亚硒酸钠(2μgSe/ml)、富硒酵母(2μgSe/ml)、富硒益生菌(2μgSe/ml)、益生菌各1ml,连续28d。实验结束时测定有关免疫功能和抗氧化能力指标。结果:胸腺指数与腹腔巨噬细胞活性,富硒益生菌组显著高于其它4组;脾脏指数,富硒益生菌组显著高于对照组、亚硒酸钠组和益生菌组;脾脏淋巴细胞转化率,富硒益生菌组显著高于对照组和益生菌组;GSH-Px与SOD活性,富硒益生菌组极显著或显著高于对照组和亚硒酸钠组;MDA水平,富硒益生菌组非常显著低于对照组和亚硒酸钠组。结论:富硒益生菌能明显改善小鼠免疫功能和抗氧化能力,其改善小鼠免疫功能的效果优于富硒酵母、亚硒酸钠和益生菌,提高小鼠抗氧化能力的效果优于亚硒酸钠。     

硒的生物学作用及其意义

硒是人和动物必需的微量元素之一 ,近年来大量资料证明 ,许多疾病与缺硒有关。就近年来人们关注的硒与疾病的关系 ,对硒的生物学特性、生物学功能及硒与机体免疫功能、人体硒缺乏及需要量部分文献资料作一回顾 ,同时对硒的开发应用国内现状和前景谈一点看法 ,仅供参考     

纳米红色元素硒对小鼠的免疫功能的调节作用

纳米红色元素硒是以蛋白质为分散剂的一种纳米粒子,粒径在２０～６０ｎｍ之间。采用动物实验研究纳米红色元素硒对免疫功能的调节作用。结果表明：与对照相比,纳米红色元素硒与亚硒酸钠各剂量组的小鼠脏器重量及其指数无明显变化;纳米红色元素硒中,高剂量组小鼠的细胞免疫功能、体液免疫功能和巨噬细胞吞噬功能明显升高,而亚硒酸钠各剂量组的上述免疫批标无明显变化。结果提示;纳米红色元素硒对小鼠免疫功能有明显的调节作用。     

富硒大蒜和洋葱中功能性硒化合物的稳定性研究

本研究设计了几个实验 ,研究富硒大蒜和洋葱中水溶性含硒化合物的稳定性。结果发现 :冷冻干燥加工能保持富硒大蒜中含硒化合物化学性质 ,富硒大蒜室温水提液中Se 甲基 硒半胱氨酸不稳定 ,蒜氨酸酶专一抑制剂盐酸羟胺能有效抑制该含硒化合物丢失 ,提示Se 甲基 硒代半胱氨酸的分解反应可能主要受蒜氨酸酶催化。富硒洋葱中同样含有蒜氨酸酶 ,但其室温水提液中Se 甲基 硒半胱氨酸却能稳定存在。Se 甲基 硒半胱氨酸是富硒大蒜一种主要功能硒组分 ,加工储存过程中应避免它损失 ,以保障富硒大蒜医学功能的发挥。富硒大蒜和洋葱含硒化合物的稳定性差异、分解机理以及分解产物活性等均有待于进一步的研究。     

硒与免疫

硒是人体必需的微量元素 ,对人体的生长发育与维持人的生命活动发挥着重要的作用。适量的硒能增强免疫功能和对疾病的抵抗力。概述了硒增强免疫功能的机理及硒与抗氧化、细胞免疫、抗病力的关系。     

Recent developments in trace element metabolism and function: newer roles of selenium in nutrition

Until recently, studies of the function of selenium focused on the selenoenzyme, glutathione peroxidase. However, the recognition that several metabolic effects of selenium are not associated with glutathione peroxidase has forced a re-evaluation of the function of this enzyme and the element. Hepatic glutathione peroxidase contains a significant percentage of the regulated selenium in the rat and is more sensitive to selenium deficiency than other selenoproteins. Thus, in addition to its enzymatic activity, it might have a storage function for the element. Another selenoprotein, designated selenoprotein P, has been found in rat plasma and has been quantitated. Its function is not yet known, but it has been postulated to be a transport protein for selenium and a defense against oxidant stress. Understanding the nutritional effects of selenium will require better characterization of glutathione peroxidase, selenoprotein P and other selenoproteins.     

蛋白质分散的纳米红色元素硒的延缓衰老作用

目的　考察以蛋白质为核、红色元素硒为膜和以蛋白质为分散剂的纳米红色元素硒是否具有延缓衰老作用。方法　采用 D-半乳糖小鼠衰老和黑腹果蝇生存模型 ,评价纳米红色元素硒的抗氧化和延长生存时间作用。结果　纳米红色元素硒能显著降低小鼠全血丙二醛含量和提高小鼠全血谷胱甘肽过氧化物酶活性 ,显著延长黑腹果蝇生存时间。结论　适当剂量的纳米红色元素硒具有延缓衰老保健作用     

微量元素硒与人体健康

微量元素硒与人体健康密切相关,文章引导人们进一步认识硒元素生理功能,树立科学补硒新观念,正确理解硒元素的二重性,走出盲目补硒的误区,找到适合自己补硒的方案。     

Selenium Intake and its Interaction with Iron Intake Are Associated with Cognitive Functions in Chinese Adults: A Longitudinal Study

Studies on the relation between selenium intake and cognitive function are inconclusive. This study aimed to examine the associations between dietary selenium intake and cognitive function among Chinese adults and tested the interaction effect of selenium intake and iron intake on cognition. Data from 4852 adults aged 55 years and above who attended the 1991–2006 China Health and Nutrition Survey (CHNS) were used. Cognitive function was assessed through face-to-face interviews in 1997, 2000, 2004, and 2006. A 3-day, 24-hour recall was used to collect dietary selenium intake. Multivariable mixed linear regression and logistic regression were used in the analyses. In fully adjusted regression models, the regression coefficients (95% confidence interval) were 0.00, 0.29 (−0.12–0.70), 0.26 (−0.18–0.70), and 0.50 (0.02–0.97) across the quartiles of selenium intake. In the subgroup analysis, the positive association between selenium intake and cognitive function was only observed in the participants who live in the southern region but not those in the northern region. The selenium-intake-to-iron-intake ratio was inversely associated with low global cognition scores. Furthermore, only those with a normal BMI had a positive association between selenium and cognition. In conclusion, high selenium intake was linked to better cognitive function and a lower risk of cognition decline in Chinese adults among those with low iron intake. A substantial interaction was found between selenium intake and BMI or region.     

硒暴露水平与农村老年人认知能力关系的研究

目的了解硒(Se)暴露水平与农村老年人认知能力的关系以及影响因素。方法对200名农村老年人进行膳食问卷调查和6项认知能力调查,采集当地环境样品、食物样品以及研究对象的指甲和血样,采用2,3-二氨基萘荧光法测定样品中硒含量,结合膳食和问卷调查结果,综合考虑可能影响老年认知能力影响因素。结果不同Se暴露指标间均有很好的相关性,在综合考虑了年龄、受教育情况、APOE基因型等因素后,膳食Se摄入量和血Se含量水平的减少与老年认知能力的下降有显著性正相关关系(P0.001)。结论老年认知能力的降低可能与Se暴露水平的降低有关。     

Neurological dysfunction occurs in mice with targeted deletion of the selenoprotein P gene

Brain function and selenium concentration are well maintained in rodents under conditions of selenium deficiency. Recently, however, targeted deletion of the selenoprotein P gene (Sepp) has been associated with a decrease in brain selenium concentration and with neurological dysfunction. Studies were conducted with Sepp(-/-) and Sepp(+/+) mice to characterize the neurological dysfunction and to correlate it with dietary selenium level. When weanling Sepp(-/-) mice were fed the basal diet (<0.01 mg/kg selenium) supplemented with 0, 0.05 or 0.10 mg selenium/kg, they developed spasticity that progressed and required euthanasia. Supplementing the diet with > or =0.25 mg selenium/kg prevented the neurological dysfunction. To determine whether neurological dysfunction would occur in more mature Sepp(-/-) mice deprived of selenium, Sepp(-/-) mice that had been fed the basal diet supplemented with 1.0 mg selenium/kg for 4 wk were switched to a selenium-deficient diet. Within 3 wk they had developed neurological dysfunction and weight loss. At 3 wk, the 1.0 mg selenium/kg diet was reinstituted. Neurological function stabilized but did not return to normal. Brain selenium concentration did not increase. Weight gain resumed. This study shows that neurological dysfunction occurs when selenium supply to the brain is curtailed and that the dysfunction is not readily reversible. Both the absence of selenoprotein P and a low dietary selenium supply are necessary for the dysfunction to occur, indicating that selenoprotein P and at least one other form of selenium supply the element to the brain.     

微量元素硒与健康的研究进展

硒是人体必需的微量矿物质,对健康有着极其重要的作用。硒是含硒蛋白的一个组份,有维持酶蛋白催化功能的作用。近年来,以下危险因素与人体缺硒有关,诸如心血管疾病、糖尿病、肝病、克山病、大骨节病、白内障、甲状腺功能异常、生殖异常、病毒感染、癌症、不良情绪及有毒元素损害免疫功能等。食入高剂量硒会有导致儿童生长迟缓的危险,此可能是硒中毒的最好指标,因而对成年人,特别是儿童必须严格谨慎补硒。     

Effects of dietary selenium and fish oil (MaxEPA) on arachidonic acid metabolism and hemostatic function in rats

This study investigated whether hemostatic function can be modified by both the consumption of fish oil and the level of dietary selenium. Male Sprague-Dawley rats were fed for 8 wk semipurified diets containing 7% corn oil (by wt) or 5.5% fish oil (MaxEPA) plus 1.5% corn oil with or without selenium supplementation. Consumption of the four diets caused no difference in weight gain, food intake or plasma malondialdehyde content. The selenium-supplemented rats had significantly higher levels of selenium and glutathione peroxidase activity in plasma. Fish oil feeding decreased ADP-induced platelet aggregation and increased bleeding time. The level of dietary selenium and type of oil interacted to influence the production of 6-keto-prostaglandin F1 alpha: more was produced when corn oil was fed in the selenium-deficient diets. These data suggest that the effect of dietary selenium on hemostatic function and the production of eicosanoids is minor.     

低硒、低碘模型大鼠F_2代生殖功能评价

目的探讨硒、碘缺乏模型动物对F2代雌性、雄性生殖功能的影响。方法采用自制人工合成饲料,利用SD大鼠建立低硒、低碘及硒碘联合缺乏动物模型,确定动物模型建立成功后,利用该模型进行大鼠的三代繁殖试验及模型稳定性监测。观察F2代模型大鼠精子形态、血清睾酮、睾丸和附睾组织病理及透射电镜超微结构的改变;检测F2代模型孕鼠生育指标、胎仔骨骼及内脏发育指标,探讨硒、碘缺乏对F2代模型动物雌性、雄性生殖功能的影响。结果经各项指标检测,三代繁殖试验中动物模型稳定性良好。通过对雄性F2代模型动物大鼠的精子形态学指标、血清睾酮含量的检测及睾丸、附睾组织病理形态学、超微结构透射电镜观察,低硒、低碘及硒碘联合缺乏均可引起雄性F2代模型动物的生殖功能损伤。通过对雌性F2代模型动物妊娠鼠体重、胚胎发育及其F3代胎仔骨骼、内脏发育的检测,低硒、低碘及硒碘联合缺乏均可引起雌性F2代模型动物生殖功能损伤。结论低硒、低碘及硒碘联合缺乏均可引起F2代模型动物生殖功能损伤。