有机硒增强BCG细胞免疫效果的初步探讨

目的:探讨酵母硒(Yeast-based selenium,Se)对卡介苗(BCG)免疫效果的影响.方法:将小鼠分为4组:A组BCG皮内接种 喂硒、B组BCG皮内接种、C组单纯喂硒、D组对照组(control).于接种4周、8周后取单个脾淋巴细胞,通过检测淋巴细胞增殖指数(Stimulation idex,SI)、IL-2、IFN-γ、细胞毒T淋巴细胞(CTL)杀伤活力及淋巴细胞颗粒酶B及穿孔素的表达量来评价机体抗结核的细胞免疫能力.结果:6项指标A与B组均高于对照组,差异有统计学意义(P＜0.05);A组的SI、IL-2、IFN-γ、CTL杀伤活力,免疫4周后分别为2.61±0.24、(172.56±9.34)pg/ml、(131.89±3.32)pg/ml、(43.91±3.21)%(8周值分别为2.32±0.31、(138.04 4-9.67)pg/ml、(129.17±2.41)pg/ml、(39.92±6.45)%,均显著高于B组(4周值:(1.62±0.14)、(134.06±9.60)pg/ml、(105.89±4.62)pg/ml、(30.46±7.97)%;8周值:1.61±0,19、(101.42±7.76)pg/ml、(102.00±5.41)pg/ml、(28.14 ±5.70)%),P＜0.05.结论:BCG与硒酵母有免疫协同作用,能诱导机体产生较强的抗结核的细胞免疫应答反应.     

长期低硒、低碘对子代发育期大鼠甲状腺形态结构及PCNA表达的影响

目的:研究长期低硒、低碘饲料喂养对子代发育期大鼠甲状腺组织形态结构以及PCNA表达的影响。方法:选取人工低硒、低碘饲料喂养繁殖的SD大鼠模型的仔3代胎鼠(F3E)、4日龄(F3P4)、21日龄(F3P21)、成年(F3A)4个时间点的甲状腺石蜡标本,常规切片,苏木精-伊红染色,免疫组化染色,镜下观察,滤泡计数。动物模型分为对照组,低硒(Se-)组,低碘(I-)组和低硒、低碘(Se-I-)组,各组分别喂以不同硒、碘水平的人工配制饲料,繁衍至仔4代。取甲状腺,制做石蜡切片。结果:各发育期时间点I-组与Se-I-组甲状腺体积增大,重量增加,滤泡增生,排列紧密。这种增生现象从胎鼠期间即有出现。在成年大鼠Se-组甲状腺滤泡有坏死和纤维化。PCNA在Se-I-组与I-组均强阳性表达,强阳性表达百分比依次为成年Se-I-组50%,I-组28.6%。21 d Se-I-组21.4%,I-组16.7%。结论:低碘和低硒、低碘均可致仔代发育期大鼠甲状腺滤泡明显增生。这种增生现象在胚胎期即表现。低硒能引起部分仔代大鼠甲状腺滤泡的坏死与纤维化。     

硒碘对大鼠肝脏细胞Ca~(2+)超载和肌动蛋白表达的影响

目的:探讨低硒、低碘对大鼠肝脏相关生化指标,细胞Ca2+超载和肌动蛋白表达的影响。方法:给大鼠饲以半合成正常饲料、低硒饲料、低碘饲料、低硒低碘饲料制作动物模型。检测各组动物肝组织相关生化指标,细胞内Ca2+浓度和肌动蛋白的表达。结果:与对照组相比,低硒组、低硒低碘组GPX、ID-I活性显著降低;低碘组GPX、ID-I活性无显著性差异;各实验组MDA水平均显著性升高;细胞内Ca2+浓度显著性升高;肌动蛋白表达量显著降低。结论:缺硒或缺碘均可明显导致机体过氧化产物堆积,缺硒缺碘可加重单纯缺硒或单纯缺碘的损伤程度。缺硒、缺碘可明显导致肝细胞Ca2+超载和降低肌动蛋白表达,提示硒、碘缺乏可加重单纯缺硒或缺碘的作用,并可能损伤细胞骨架蛋白。     

Relationship between selenium concentration in child hair and the distribution of Kashin-Beck Disease in Tibet,China

The focus of this study is to determine the relationship between selenium (Se) concentrations in child hair and the distribution of Kashin-Beck disease (KBD) in Tibet. The hair of children in typical KBD-affected areas and non-disease areas was collected, and its Se concentrations were measured by atomic fluorescent spectrometry. The Se concentrations in child hair were (0.13±0.04) and (0.18±0.07) μg/g respectively in KBD areas and non-disease areas respectively, which are significantly different. In areas supplemented with Se in Tibet, the Se concentration of hair in KBD-affected areas was higher than that in non-diseased areas, being (0.28±0.03) and (0.18±0.04) μg/g respectively. There is a close relationship between the Se concentrations in hair and KBD distribution. Se supplement increase the Se concentrations in the human body. Appropriate Se supplementation is important to prevent KBD in Tibet. Translated from Chinese Journal of Endemiology, 2006, 25(1): 70–72 [译自: 中国地方病学杂志]     

Selenium status of New Zealand infants fed either a selenium supplemented or a standard formula

Objective: New Zealand soils are deficient in the essential micronutrient, selenium. New Zealand infants have low selenium levels at birth and experience a further decline if fed cows milk based formula. This study examined the selenium status of infants fed with a new commercially available selenium supplemented formula.
Methodology Forty-four newborn infants, whose mothers wished to formula feed, were randomized in an open controlled trial to be fed a commercially available selenium supplemented cows milk formula (containing 17 μg Se/L) or an unsupplemented formula (containing 4.6 μg Se/L). Cord, 1 and 3 month blood samples were obtained for selenium status (plasma and red cell selenium and glutathione peroxidase) and thyroid function.
Results Mean plasma selenium and glutathione peroxidase values were significantly higher in supplemented than unsupplemented infants at 1 month (unpaired t -tests; P <0.0001 and P = 0.001 respectively) and 3 months ( P <0.0001 and P = 0.0005). Analysis within treatment groups between time points (paired t -tests) showed that selenium supplementation prevented the fall in plasma selenium from birth to 1 month seen in unsupplemented infants and was associated with a rise in levels between 1 and 3 months ( P = 0.002).
Conclusions Supplementing cows milk formula with selenium to replicate the levels found in breast milk is nutritionally sound. Feeding from a few days of age with a formula containing 17 μg Se/L in infants with low selenium status at birth is sufficient to cause a rise to 80% of adult levels at 3 months of age.     

The selenium status of children with phenylketonuria: Results of selenium supplementation

The selenium status of children with phenylketonuria on a synthetic low phenylalanine diet was assessed. Correlation between blood selenium and red cell glutathione peroxidase was unsatisfactory ( r = 0.65) due to the poor discrimination of red cell glutathione peroxidase with a low selenium diet. No symptoms of deficiency were observed. Supplementation with 50 μg per week of selenium as brewers yeast tablets over a period of 6 months significantly increased the blood selenium of the phenylketonuric children. Plasma Vitamin E levels were within normal limits. The supplementation effectively doubled their selenium intake to 15–17 μg per day, which is probably sufficient for this group with an adequate Vitamin E status, though considerably lower than the recommended minimum intake of 50 μg per day.     

Low serum selenium concentration in patients with cervical or endometrial cancer

Serum concentrations of selenium were determined in 37 patients with cervical and 64 patients with endometrial cancer. The patients had lower (P less than 0.001) serum concentrations of selenium than the age-, weight- and place of residence-matched paired control women. There was no difference in the selenium concentration between various age groups or different clinical stages of cervical or endometrial cancer. A low serum concentration of selenium might be a contributing factor in uterine carcinogenesis.     

Toenail selenium concentration and lung cancer in male smokers (Finland)

Background: The objective of this investigation was to evaluate the association between toenail selenium concentration and lung cancer risk in male smokers. Methods: We conducted a nested case–control study within the Alpha–Tocopherol Beta–Carotene Cancer Prevention Study cohort. This substudy included 250 randomly selected incident lung cancer cases and 250 controls matched on age (up to ± 5 years), intervention group assignment, and date or randomization (±15 days). Odds ratios (ORs) and 95% confidence intervals (CIs) were determined using conditional logistic regression methods. Finland began fortification of argricultural fertilizers in the fall of 1984, increasing the dietary intake, plasma, and toenail selenium concentrations for the population. The present analyses were based on the calculated residual of toenail selenium after regressing it on date of randomization. The selenium residual and the interaction of the residual with date of randomization were included in models with smoking status and body mass index as covariates. Results: We observed a suggestion of a protective association for higher selenium status among men who entered the trial early (when the range of selenium values included very low levels). The OR for men with adjusted toenail selenium concentrations at the 75th percentile compared to those with the lowest selenium concentrations ranged between 0.20 (0.09–0.44) for men randomized earliest in the trail and 0.61 (0.27–1.41) for men randomized in the fifth year. Conclusions: These results suggest that low selenium status may be associated with increased risk for lung cancer.     

富硒蛋鸡硒水平的研究

在蛋鸡饲料中添加有机硒 ,通过生物转化可以提高鸡体的硒含量 ,从而生产富硒鸡肉和鸡蛋。用新极谱法分别测定了富硒和对照蛋鸡的血、肉、蛋、毛及粪中的硒含量 ,测得富硒蛋鸡的硒含量分别为 4 5 1 9±4 2 1μg/L、0 2 0 6± 0 0 0 6mg/kg、0 4 15± 0 0 5 2mg/kg、1 6 6 3± 0 199mg/kg及 1 349± 0 2 39mg/kg ,分别为对照蛋鸡的 4 8、1 6、3 8、5 0及 31倍。     

硒对高碘小鼠肝脏两种含硒酶的影响

目的:研究硒对高碘小鼠肝脏含硒酶的影响,探讨硒干预高碘危害的机制。方法:40只雌性Balb/c小鼠按体重随机分为4组:正常对照组(NC);高碘对照组(HI),饮用3.0mg/LI的高碘水;高碘+硒I组(HI+Se1),高碘水中补充0.5mg/LSe;高碘+硒II组(HI+Se2),高碘水中补充1.0mg/LSe。5个月后,观察甲状腺病理变化,测定血清总T4(TT4)、总T3(TT3)、反式T3(rT3)水平以及肝脏硒含量、谷胱甘肽过氧化物酶(GSH-Px)活性、1型脱碘酶(DI-1)活性及mRNA表达。结果:高碘组小鼠出现了弥漫胶质性甲状腺肿;与正常对照组相比,高碘组的血清TT4水平显著升高,TT3水平显著降低;而补硒可显著抑制TT4的升高和TT3的降低;高碘组肝脏硒含量降低,MDA含量显著升高,GSH-Px和DI-1活性分别降低了47%和33%,DI-1mRNA的表达也下调。而两个补硒组能显著升高肝硒含量,增强GSH-Px活性以及DI-1活性和表达,其中以0.5mg/L的硒剂量作用最为明显。结论:适当剂量的硒可通过影响含硒酶的活性和mRNA的表达来发挥对高碘危害的干预作用。