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.     

陕南安康地区大竹园镇砷中毒患者血清PICP、PINP与COL1α1序列检测

目的 研究陕南安康地区大竹园镇高砷高氟高硒地区的砷皮肤损伤患者体内Ⅰ型胶原代谢状况.方法 采用病例对照研究,选取安康大竹园镇燃高砷高氟高硒石煤区29例砷皮肤损伤患者为病例组,西安市非砷中毒区30例为对照组.用石墨炉原子吸收光谱法测定砷和硒含量.氟离子选择性电极法测定氟含量,ELISA检测血清中Ⅰ型前胶原羧基前肽(PICP)和Ⅰ型前胶原氨基前肽(PINP)的含量,高保真PCR扩增-美国ABI3100测序仪作正反向直接测序检测Ⅰ型胶原α1多肽链(COL1α1)碱基突变.结果 在偏相关分析中控制其他影响因素后,PICP与血清氟呈弱负相关r=-0.4,P≤0.05),PINP与发氟呈中度负相关(r=-0.5,P<0.05),与发硒呈中度正相关(r=0.5,P<0.05).但血清PICP、PINP与COL1α1序列在病例组和对照组间无统计学显著性差异(P>0.05).结论 发氟和发硒是影响PINP代谢的主要影响因素,且发氟升高可使PINP降低而发硒升高町使PINP增高.但在陕南安康地区大竹园镇砷、氟和硒三元素联合性增高地区的砷皮肤损伤患者体内的PICP、PINP含量和Ⅰ型胶原α1基因序列却无显著性改变.提示在该地区,发硒增高引起PINP的升高可能抑制了由发氟升高引起PINP的降低.     

锌、硒对砷诱导金属硫蛋白合成影响的研究

目的:探讨锌、硒对砷诱导金属硫蛋白合成的影响。方法:采用亚慢性毒性实验方法,分别测定小鼠肝脏中金属硫蛋白(MT)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活力。结果:砷低剂量组、单纯锌组和单纯硒组肝脏MT含量升高,高于对照组和砷高剂量组(P<0.05)。随着砷染毒剂量的增加,小鼠肝脏组织中MDA含量增加,SOD、GSH-Px活性降低,且呈剂量-效应关系。结论:亚砷酸钠能够诱导小鼠产生金属硫蛋白,金属硫蛋白含量与抗氧化能力存在相关性,锌、硒能抑制MDA生成量,提高SOD、GSH-Px活性,增加抗氧化能力,从而拮抗砷毒性。     

硒酵母中硒的化学形态分析与评价

 利用Ｔｒｉｓ－缓冲液－甘油提取法对硒酵母的化学形态进行了分析，并与透析法进行比较。结果表明，经过特殊工艺生产的硒酵母虽然总硒含量达到４０００μｇ／ｇ以上，但其中５０％以上的硒为硒蛋氨酸形态的蛋白质或其它大分子态硒，无机态硒仅占３％左右，而游离态硒只占０．０１％。说明硒酵母有广阔的开发前景，同时也为硒制剂提供了适宜的质量监测方法。     

Hypothesis: Iodine, selenium and the development of breast cancer

Background: In this paper we examine some of the evidence linking iodine and selenium to breast cancer development. Seaweed is a popular dietary component in Japan and a rich source of both of these essential elements. We hypothesize that this dietary preference may be associated with the low incidence of benign and malignant breast disease in Japanese women. In animal and human studies, iodine administration has been shown to cause regression of both iodine-deficient goiter and benign pathological breast tissue. Iodine, in addition to its incorporation into thyroid hormones, is organified into anti-proliferative iodolipids in the thyroid; such compounds may also play a role in the proliferative control of extrathyroidal tissues. Selenium acts synergistically with iodine. All three mono-deiodinase enzymes are selenium-dependent and are involved in thyroid hormone regulation. In this way selenium status may affect both thyroid hormone homeostasis and iodine availability. Conclusion: Although there is suggestive evidence for a preventive role for iodine and selenium in breast cancer, rigorous retrospective and prospective studies are needed to confirm this hypothesis.