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。     

纳米红色元素硒的护肝、抑瘤和免疫调节作用

目的 :　研究纳米红色元素硒的护肝、抑瘤和免疫调节作用。方法 :　采用 CCl4 致小鼠急性肝损伤、S180 移植瘤和免疫模型 ,评价纳米红色元素硒的保护、抑制和调节作用。结果 :　纳米红色元素硒提高血和肝硒、抑制 CCl4 所致的肝丙二醛 (MDA)和血清天冬氨酸氨基转移酶(AST)升高 ,降低 S180 荷瘤鼠瘤重和提高 S180 荷瘤鼠的吞噬率和天然杀伤细胞 (NK)活性 ,提高正常小鼠的免疫活性 ,均有显著性差别 (P<0 .0 5)。口服 LD50 为 Se 1 1 2 .98mg/ kg bw。结论 :　纳米红色元素硒有护肝、抑瘤和免疫调节作用 ,是已发现的急性毒性最低的补硒制剂     

纳米红色元素硒抑制肿瘤和提高免疫功能的作用

已知硒化合物 ,如亚硒酸钠和硒蛋氨酸 ,有较高生物活性和毒性。而零价元素硒 ,如灰和黑色元素硒 ,几乎无生物活性和毒性〔1〕。目前 ,对于红色元素硒生物性质的认识是模糊的〔2～ 4〕。 1985年 ,Ｎｕｔｔａｌ在ＭｅｄｉｃａｌＨｙｐｏｔｈｅｓｉｓ杂志发表论文〔5〕,提出胶体状态红色元素硒具有或至少是在特定环境下具有生物活性的假说 ,这只是一种尚未被实验证实的理论构想。我们制备了一种能稳定存在的胶体状态红色元素硒 ,称之为纳米红色元素硒。本文拟从营养剂量水平 ,研究纳米红色元素硒是否具有抑制肿瘤和提高免疫功能的作用 ,为其应…     

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     

纳米红色元素硒对新生动物缺氧缺血性脑损伤的保护作用

纳米红色元素硒（NS）具有多种生物学功能,在适当剂量下,具有延缓衰老的保健作用等。近年研究发现它的抗氧化功能对创伤性脑损伤有很好的保护作用,但对新生大鼠缺氧缺血性脑损伤（HIBD）的保护作用目前尚未见报道。为此,我们进行了NS对新生大鼠缺氧缺血性脑损伤保护作用的研究,报道如下。     

纳米红色元素硒对四氯化碳致大鼠肝损伤的影响

目的 探讨纳米红色元素硒在CCl4诱发大鼠实验性肝损伤中的干预作用.方法 将清洁级Wistar大鼠按体重随机分为阴性对照组、阳性对照组、纳米红色元素硒对照组、纳米红色元素硒高、中、低剂量组,分别灌胃给予生理盐水、生理盐水、纳米红色元素硒(0.2、0.2、0.1、0.05mg/kg).8d后,阴性对照组和纳米红色元素硒对照组一次性腹腔注射植物油(3 ml/kg),阳性对照组和纳米红色元素硒高、中、低剂量组均一次性腹腔注射5.18 mol/L,四氯化碳(3 ml/kg).24 h后,处死大鼠,称量体重、肝脏重量,计算肝脏系数.测定大鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活力,采用HE染色法检测肝组织病理情况,采用免疫组织化学法检测大鼠肝组织中bax、p53基因蛋白表达.结果 阴性对照组和纳米红色元素硒对照组肝组织正常;阳性对照组、纳米红色元素硒高、中、低剂量组肝脏体积增大,颜色灰暗,并有腹水,肝组织小叶内出现气球样变和脂肪变,并有大量中性粒细胞浸润.纳米红色元素硒对照组与阴性对照组肝脏系数、AST、ALT活力、bax、p53基因蛋白表达的积分光密度(IOD)值和阳性面积间,差异均无统计学意义(P＞0.05).阳性对照组、纳米红色元素硒高、中、低剂量组肝脏系数、AST、ALT活力、bax、p53基因蛋白表达的IOD值和阳性面积高于阴性对照组、纳米红色元素硒对照组,差异均有统计学意义(P＜0.01);且纳米红色元素硒对照组＜低剂量组＜中剂量组＜高剂量组.结论 在本次实验剂量下,纳米红色元素硒对大鼠肝脏无损伤作用,对CCl4诱导的急性实验性肝损伤无明显保护作用.     

硒及其生物利用度

人和动物体内硒缺乏与疾病发生有关。硒在人体内有(必需性和毒性)的双重效应,它的必需性和毒性的量亦非常接近,所以为治疗和预防疾病应适当检测每日硒的饮食摄入量。然而,仅仅了解食物中的硒含量是不够的,还必须了解硒的生物利用度和吸收,利用和转化的程度。现就硒的重要性、硒补充和硒生物利用度做一简评。     

大鼠硒耗竭过程中不同组织硒蛋白利用硒的优先性

以低硒酵母配制的低硒基础饲料（含硒量为０．０１ｍｇ／ｋｇ）和在此基础上加亚硒酸钠配成硒水平为０．５０ｍｇ／ｋｇ的足硒饲料来喂养雄性Ｗｉｓｔａｒ断乳大鼠。于０、１、２、４、６、８、１２、１５、１７、１９、２０和２４周时处死大鼠取其组织,分别对各种组织中的硒、细胞内谷胱甘肽过氧化物酶（ｃＧＰＸ）、细胞外谷胱甘肽过氧化物酶（ｅＧＰＸ）、磷脂氢谷胱甘肽过氧化物酶（ＰＨＧＰＸ）、Ⅰ型脱碘酶（ＩＤⅠ）和Ⅱ型脱碘酶（ＩＤⅡ）活性进行动态观察。结果发现睾丸中的硒和脑垂体中的ｃＧＰＸ在耗竭过程中降低速度较其它组织慢,且降低幅度较小;而硒蛋白中ＩＤⅠ和ＰＨＧＰＸ对硒的利用优先于ｃＧＰＸ和ｅＧＰＸ,ＰＨＧＰＸ和ＩＤⅠ的功能可能比ｃＧＰＸ和ｅＧＰＸ更重要。     

生物纳米硒饲料添加剂对淡水养殖鱼类影响的研究

通过投加生物纳米硒饲料添加剂,进行鲤鱼、鲫鱼、白鲢和鳙鱼的含硒量、体重、产量、成活率、饵料系数、抗病力、色泽和肉质的对比试验,说明生物纳米硒的影响作用。结果表明,投加生物纳米硒饵料4个月,鲤鱼、鲫鱼、白鲢和鳙鱼的含硒量明显增加,分别为0.424,0.453,0.285和0.306 mg/kg,分别是对照样的1.64、1.66、1.22和1.28倍。鲤鱼和鲫鱼的体重、产量、成活率分别增加0.085 kg,6298 kg,2.5%和0.015 kg,699kg,3.0%,投药量大大减少,抗病力增强,饵料系数减少,鳞片呈金黄色,具有肉质较紧、肉层厚等优点。     

纳米红色元素硒对C57小鼠Lewis肺癌移植瘤形成与转移的影响

纳米红色元素硒是一种纳米粒子,粒径在20nm～60nm之间.采用Lewis肺癌(LLC)移植瘤模型观察其抗肿瘤功效.小鼠分别灌喂纳米红色元素硒2mg/kg·bw、4mg/kg·bw、8mg/kg·bw3种剂量10天.结果表明:与正常对照组比,纳米红色元素硒可显着抑制LLC移植瘤的体积与重量.小鼠分别灌喂纳米红色元素硒8mg/kg·bw和环磷酰胺20μg/kg·bw10天,与正常对照组比,二者皆可明显抑制LLC移植瘤的体积、重量、自发性肺转移,延长荷瘤小鼠的生存时间,二者之间无显着性差异.表明,纳米红色元素晒有较好的抗Lewis肺癌移植瘤效果.     

硒对铅毒性的拮抗作用

近年来,随着对硒研究的不断深入,人们发现硒有拮抗铅毒性的作用:一方面硒是体内抗氧化系统的重要组成成分,能明显改善铅中毒诱发的脂质过氧化反应,减轻铅的危害;另一方面硒与金属有很强的亲和力,可在体内与铅结合形成金属硒蛋白复合物,从而可降低铅的毒性作用。本文从硒拮抗铅毒性作用的机理、硒对铅毒性的拮抗作用以及不同形式的硒对铅毒性作用的影响三个方面综述了硒与铅毒性之间的关系。     

Bioavailability of selenium from foods

Selenium (Se), an essential nutrient, is needed for activity of several important proteins. Additionally, the consumption of Se in amounts that exceed the Recommended Dietary Allowance (RDA) may protect against prostate and colorectal cancer. Supplemental Se may be acquired through the diet, but Se bioavailability depends on the source. Therefore, dietary advice concerning improvement of Se intake depends on characterization of Se bioavailability from Se-containing food sources.     

砷、氟、硒联合对大鼠全胚胎的发育毒性研究

用体外全胚胎培养（ｗｈｏｌｅｅｍｂｒｙｏｃｕｌｔｕｒｅ,ＷＥＣ）探讨硒、氟和砷三者以不同配比浓度对旋转培养４８ｈ的大鼠胚胎所产生的联合作用。３×３×３析因分析结果表明硒、氟、砷联合对发育呈协同毒性作用;随着三种化学物剂量的配比变化,发育毒性效应亦不同,７个低剂量联合组的协同作用主要表现为致畸性,而高剂量联合组〔（２．０μｇ硒＋１０．０μｇ氟＋１．０μｇ砷）／ｍｌ培养基〕的协同作用以致死性为主。结果还提示卵黄囊胎盘结构与功能紊乱是硒、氟、砷联合致畸的重要机制之一。     

Acute toxicity of chlorpyrifos to the non-target organism Cnesterodon decemmaculatus

Chlorpyrifos is the most used insecticide in Argentina. Cnesterodon decemmaculatus is a widely distributed, endemic fish from Neotropical America. It attains high densities in the shallow water assemblages of Argentina and Brazil. The aim of this study was to assess the acute toxicity of chlorpyrifos to C. decemmaculatus. The mean 96-h LC₅₀ of three independent determinations was 105.3 (±?3.1) μg/L. Sublethal effects were observed. Swimming behavioral changes at each chlorpyrifos exposure concentration were reported. C. decemmaculatus represents a good model for ecotoxicological risk assessment.     

Acute nickel toxicity in electroplating workers who accidently ingested a solution of nickel sulfate and nickel chloride

Thirty-two workers in an electroplating plant accidently drank water contaminated with nickel sulfate and chloride (1.63 g Ni/liter). Twenty workers promptly developed symptoms (e.g., nausea, vomiting, abdominal discomfort, diarrhea, giddiness, lassitude, headache, cough, shortness of breath) that typically lasted a few hours but persisted 1-2 days in 7 cases. The Ni doses in workers with symptoms were estimated to range from 0.5 to 2.5 g. In 15 exposed workers who were tested on day 1 postexposure, serum Ni concentrations ranged from 13 to 1,340 micrograms/liter and urine Ni concentrations ranged from 0.15 to 12 mg/g creatinine. Ten subjects (with initial urine Ni concentrations greater than 0.8 mg/g creatinine) were hospitalized and treated for 3 days with intravenous fluids to induce diuresis, resulting in a mean elimination half-time (T1/2) for serum Ni of 27 hours (SD +/- 7 hour), which was significantly shorter (p less than .001) than the mean T1/2 of 60 hours (SD +/- 11 hours) in 11 subjects who did not receive intravenous fluids. Laboratory tests showed transiently elevated levels of blood reticulocytes (N = 7), urine albumin (N = 3), and serum bilirubin (N = 2). All subjects recovered rapidly, without evident sequellae, and returned to work by the eighth day after exposure.     

Bioavailability of selenium from selenium-enriched milk assessed in the artificially reared neonatal pig

There is interest in pre-farm gate fortification of the diet with highly bioavailable selenium (Se) to improve public health, so the aim of the present study was to determine the bioavailabilities of Se from Se-enriched whole milk and milk replacers supplemented with exogenous Se in neonatal pigs. Milk enriched with Se (1070 μg Se/kg dry matter (DM); HSeM) was obtained from cows supplemented with selenised yeast while the control milk diet (135 μg Se/kg DM; LSeM) was made using milk powder from non-supplemented cows. Additional diets were formulated by adding selenised yeast (HSP) or selenate (HSN) to the LSeM diet to give final Se concentrations of 1070 μg Se/kg DM. Neonatal pigs were trained to drink milk and then randomly allocated to their four respective diets and slaughter times (0, 7, 14, 28 and 42 days of feeding). Plasma Se increased over the first 21 days in pigs consuming HSeM, reaching a value over three times higher than the LSeM pigs. Plasma Se concentrations plateaued at 45, 125, 122 and 170 μg/mL for LSeM, HSN, HSP and HSeM pigs, respectively ( P  < 0.001). After 28 days, muscle Se plateaued at 47, 106, 237 and 486 μg/kg for LSeM, HSN, HSP and HSeM pigs, respectively ( P  < 0.001). Colonic selenoprotein P gene expression was greater ( P  = 0.024) in pigs fed HSeM compared with LSeM while the HSP and HSN were intermediate. These data suggest that Se in milk from cows fed selenised yeast is highly bioavailable and may offer a means of delivering supplemental Se to humans.     

The relative bioavailability in humans of elemental iron powders for use in food fortification

Summary Background Bioavailability data in humans of elemental iron powders is limited although elemental iron is a common form of iron when used as a fortificant. Aim of the study The relative bioavailability (RBV) of seven elemental iron powders, five commercially available and two developmental are evaluated. In addition, one commercial electrolytic iron powder given with ascorbic acid (AA) was examined. Methods Based on a validated method this double–blinded randomized crossover study included three groups of male blood donors (n = 3*16) who were served rolls fortified with different elemental iron powders or ferrous sulfate (FeSO₄) nine weeks apart. Blood samples were drawn every hour for six hours. RBV was obtained by comparing the increase in serum iron concentration induced by the elemental iron with the increase induced by FeSO₄. Results All elemental iron powders studied were significantly less well absorbed compared to FeSO₄. The electrolytic iron given with 50–mg AA was as well absorbed as FeSO₄ (molar ratio = 1:6, AA:Fe). The mean RBVs of the iron powders were: electrolytic (A–131, RBV = 0.65); electrolytic (Electrolytic, RBV = 0.59); carbonyl (Ferronyl, RBV = 0.58); H–reduced (AC– 325, RBV = 0.56); H–reduced (Hi–Sol, RBV = 0.50); carbonyl (CF, RBV = 0.37); reduced (Atomet 95SP, RBV = 0.36). The reduced iron was distinguished by having significantly lower RBV (0.36) although no significant overall ranking was possible. Conclusion Based on a validated method this doubleblinded cross–over study in humans showed that the evaluated elemental iron powders currently available for commercial use are significantly less well absorbed compared to FeSO₄. The results indicate that the reduced iron powder was absorbed to a lower extent compared to the other iron powders and only 36% compared to FeSO₄. Ascorbic acid seems to improve the bioavailability of elemental iron even though a rather low molar ratio is used. Thus, if confirmed, this enhancing effect of ascorbic acid on elemental iron when used as a fortificant could be used by co–fortifying them.