补硒对预防原发性肝癌的作用

原发性肝癌病因为多因素协同作用的结果,我国肝癌病因以乙型肝炎病毒（ＨＢＶ）、黄曲霉毒（ＡＦＢ１）、饮水污染和遗传等因素为主。某些微量元素缺乏,促进了肝癌的发生、发展。科学工作者针对肝癌病因采取以“防治肝炎、管粮防霉、改良饮水、适量补硒”为中心的综合防治措施,已取得初步成效,本硒进一步阐明在肝癌高发现场应用补硒肝癌的作用。通过四年前瞻研究结果表明,食硒盐补硒组较对照组血硒ＧＳＨ－ｐｘ升高,ＵＤＳ、微     

肝病患者血硒水平与甲胎蛋白浓度的相关性研究

硒是人体不可缺少的一种微量元素,其水平的高低影响着机体的肿瘤免疫反应,甲胎蛋白是癌胚蛋白,其浓度的高低反映了肝脏损害的程度（除胎儿期外）,本文血硒水平与甲胎蛋白浓度相关性研究结果表明,两者呈负相关（相关系数－0．627）,且血硒水平呈现慢乙肝＞肝硬化＞肝癌,提示硒对肝脏具有一定的潜在保护作用,补硒可以预防肝癌,在肝癌治疗中适量补硒,对增强患者免疫功能,延长生存期有着十分重要的临床意义。     

高危人群补硒预防肝癌的作用

通过调查、抽血检测男性20～65岁18000人,检出HBsAg+、AFP(-)、肝功能(ALT)基本正常的患者2065例,按地区随机分为补硒组1112例及对照组953例。补硒组每人每天服亚硒酸钠05mg1片,对照组则服安慰剂1片。通过服药前瞻观察2年,补硒组血硒显著升高,与对照组比较有明显差异(P<001);相应谷胱甘肽过氧化物酶随之升高,与对照组比较亦有显著差异(P<001);相反补硒组外周血淋巴细胞微核检出率显著低于对照组(P<001)。补硒组肝癌发病率170863/10万(19/1112),对照组430220/10万(41/953),有非常显著差异(P<001),进一步证实在肝癌高发区高危人群中,尤其是低硒地区,补硒可以预防肝癌,补硒方法简单,易于推广。     

硒预防原发性肝癌的研究进展

综述了从八十年代以来，在肝癌高发区进行的微量元素硒与肝癌关系的研究，包括流行病学、动物实验和防治应用等方面。     

硒化螺旋藻对实验诱发大鼠肝癌过程的作用

目的:观察硒化螺旋藻(Se-spirulina)对黄曲霉毒素B1(AFB1)致肝癌作用的影响。方法:实验动物按随机区域分组法分为A、B、C组,每组15只,A、B、C组分别为高剂量组、低剂量组、对照组,各组动物腹腔注射AFB1两周,A、B组大鼠在接受AFB1期间分别喂食含量分别为9.3×10-3和2.3×10-3的硒化螺旋藻混合饲料,8周后处死动物,观察各组动物肝组织内γ-谷氨酰转肽酶阳性肝细胞增生灶(-γGT灶)的数量(个/cm2)和大小(mm2/个)。结果:高、低剂量硒化螺旋藻均能抑制AFB1诱发的-γGT灶的数量和大小,高剂量组、低剂量组-γGT灶的数量分别为(0.90±1.07)个/cm2和(3.72±4.72)个/cm2,均低于对照组(6.10±6.30)个/cm2,高剂量组与对照组相比有显著意义(P<0.05),抑制率分别为85%和39%;高剂量组、低剂量组-γGT灶大小分别为(0.24±0.28)mm2/个和(1.94±2.32)mm2/个,均低于对照组(2.36±3.76)mm2/个,但无显著意义(P>0.05),抑制率分别为90%和17%。结论:硒化螺旋藻有抑制AFB1诱发大鼠肝癌前病变的作用,而高剂量硒化螺旋藻的抑制作用更优。     

高效液相色谱-电感耦合等离子体质谱分析几种富硒产品的硒总量及其形态

本文采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析了几种富硒产品中硒的总量及其形态。结果表明,四种富硒产品的硒总量均有不同程度增加,富硒大米和富硒茶叶中的硒总量较高,分别为1.300μg/g和0.459μg/g,富硒大米和富硒大葱的富硒倍率相对较高,分别为未富硒产品的24.1和17.8倍。以0.1mol/LHCl辅助超声预处理样品进行富硒螺旋藻和富硒大葱中硒的形态分析,发现富硒大葱中的硒主要为有机态的甲基硒代半胱氨酸(MeSeCys)以及部分硒代蛋氨酸(SeMet),而富硒螺旋藻中的硒大部分为无机硒。说明经根部吸收等富集方式可有效将无机硒转化为有机硒,而某些方式未能完全转化。     

HPLC-ICP-MS联用技术在富硒金针菇硒的形态分析中的应用

从富硒培养的金针菇中分离得到含硒化合物, 并采用SE-HPLC-ICP-MS联机技术对浸提液中的含硒化合物进行分离分析; 同时对样品中的硒蛋白在特定条件下水解, 采用RP-HPLC-ICP-MS联机技术对水解液中硒代氨基酸进行确认, 并测定其中硒的含量. 结果表明, 可溶态硒是富硒金针菇中硒的主要存在形式, 其中小分子含硒有机化合物中的含硒量占浸提液中硒的71.87%; 而含硒蛋白所占比例为4.88%; 进一步确定富硒金针菇中含有硒代胱氨酸、硒代蛋氨酸和由二者组成的含硒多肽等, 各形态硒的含量为总硒量的12.3%, 17.6%和36.8%. 本方法将具有高效分离能力的色谱技术与高灵敏度的元素检测技术成功结合, 用于含硒生物分子中硒的在线分析, 具有快速、灵敏及准确等特点.     

中国富硒食品的生产现状及趋势

对硒的生物学作用和目前已经开发的富硒食品(富硒西瓜、富硒灵芝、富硒茶叶、富硒牛奶、富硒猪肉和富硒鸡蛋等)进行了概述。当前富硒食品的技术含量大多偏低,技术水平有待提高;价廉物美的富硒食品受市场欢迎,科学论证富硒食品的转化机制是今后科研的一个方向。     

硒缺乏的预防

防治硒缺乏可采用补硒方法。目前常用的补硒制剂主要包括有机物（硒蛋氨酸）和无机物（亚硒酸钠或硒酸钠）。硒主要在小肠吸收，人体对硒的吸收率很高，约为50％～100％。膳食来源的硒主要以硒蛋氨酸形式存在。硒蛋氨酸和硒酵母中生物结合形式的硒在直接消除氧自由基、抑制脂质过氧化方面，在激发免疫反应、促进免疫蛋白合成、刺激淋巴细胞增殖方面，在提高肝脏、肌肉中硒含量和提高肝GSH-Px活性方面，效果均明显好于无机硒化合物。与硒的无机盐相比，硒蛋氨酸不仅生物学活性高出许多，而且更容易被吸收，     

高效液相色谱与电感耦合等离子体质谱联用技术用于胁迫富硒海带硒形态研究

通过对海带胁迫富硒培养, 研究了海带对硒的富集总量及硒化学形态转变. 建立了反相离子对缓冲盐等3个色谱系统的高效液相色谱与电感耦合等离子体质谱联用(RP-HPLC-ICP-MS)技术测定亚硒酸钠、硒甲基半胱氨酸(MeSeCys)、硒代蛋氨酸(SeMet)三种硒形态. 采用3种提取溶剂, 超声提取缩短提取时间, 分离检测富硒海带的主要硒形态为亚硒酸钠、硒甲基半胱氨酸和硒代蛋氨酸.     

BOOK REVIEWS

Book reviewed in this article:
Chemical and Biochemical Applications of Lasers. Volume II. Edited by C. B radley M oore
Laser Spectroscopy III, Springer Series in Optical Spectroscopy. Volume 7. Edited by J. L. H all and J. L. C arlsten
Photosynthesis. Second Edition, D. O. H all and K. K. R ao
The Amphibian Visual System. Edited by K atherine V. F ite
The Physiology and Biochemistry of Seed Dormancy and Germination. Edited by A. A. K han
Phytochrome and Plant Growth. Studies in Biology NO. 68. Edited by R. E. K endrick and B. F rankland
The Science of Photobiology. Edited by K endric C. S mith
Photosensitized Reactions, By M. K oizumi , S. K ato , N. M ataga , T. M atsuura and Y. U sui
Bioenergetics of Membranes, Edited by L. P acker , G. C. P apageorgiou and A. T rebst     

Kinetics of solid state thermal decomposition reactions

The author wishes to thank Prof. C. G. R. Nair, Dr. V. R. Gowarikar, Mr. M. R. Kurup and Dr. K. V. C. Rao for their encouragements. Thanks are due to Prof. P. M. Madhusudanan and Dr. K. Krishnan for helpful discussions and to Director, VSSC for the kind permission to publish this work.     

Bemerkungen zu den „Viskositätstheorien“ von K. C. Sen,N. R. Dhar und Mitarbeitern

Ohne Zusammenfassung K. C. Sen, Koll.-Zeitschr.38, 253 (1926); D. N. Chakravarti u. N. R. Dhar, Journ.Phys. Chem.29, 1556 (l925);30, 1646 (1926); Zeitschr. f. anorg. Chem.152, 393 (1926); D. N. Chakravarti u. N. R. Dhar, Koll.-Zeitschr.42, 124 (1927); N. R. Dhar, D. N. Chakravarti u. M.N.Chakravarti, Koll.-Zeitschr.44 225 (1928).     

Book Reviews

Book reviewed in this article:
The Effects of Constant Light on Visual Processes. Edited by T. P. W illiams and B. N. B aker . Plenum Press, New York, 1980. 455 pp. $45.00.
Radiation Biology and Chemistry: Research Developments. Edited by H. E. E dwards , S. N avaratnam , B. J. P arsons and G. O. P hillips . Elsevier Scientific, Amsterdam, 1979. 505 pp. $78.00     

BOOK REVIEWS

Book reviewed in this article:
Chemistry of Atmospheres, An introduction to the chemistry of the atmospheres of Earth, the planets and their satellites .Edited by Richard P. Wayne
Advances in Photochemistry , vol.13 Edited by D. H. Volman, K. Gollnick and G. S. Hammond.
Multiple Photon Infrared Laser Photophysics and Photochemistry . V. N. Bagratashvili, V. S. Leto-khov, A. A. Makarov and E. A. Ryabov.     

BOOK REVIEW

Structure and Bonding , Volume 41, Edited by J. D. D unitz , J. B. G oodenough , P. H emmerich , J. A. I bers , C. K. J ørgensen , J. B. N eilands , D. R einen and R. J. P. W illiams .     

Electrophoresis of spheres with uniform zeta potential in a gel modeled as an effective medium

The effective medium model [H.C. Brinkman, Appl. Sci. Res. A 1 (1947) 27] is used to calculate the electrophoretic mobility of spheres in a gel with uniform zeta potential on their surface. In the absence of a gel support medium or ion relaxation (the distortion of the ion atmosphere from equilibrium due to the presence of an external flow or electric field), our results reduce to those of Henry [D.C. Henry, Proc. R. Soc. London Ser. A 133 (1931) 106]. The relaxation effect can be ignored for weakly charged particles, or for particles with low absolute zeta potential. Using a procedure similar to that employed by O'Brien and White [R.W. O'Brien, L.R. White, J. Chem. Soc. Faraday Trans. 2 74 (1978) 1607], the relaxation effect is accounted for in the present work and results are presented over a wide range of particle sizes, gel concentrations, and zeta potentials in KCl salt solutions. In the limit of no gel, our results reduce to those of earlier investigations. The procedure is then applied to the mobility of Au nanoparticles in agarose gels and model results are compared to recent experiments [D. Zanchet, C.M. Micheel, W.J. Parak, D. Gerion, S.C. Williams, A.P. Alivisatos, J. Phys. Chem. B 106 (2002) 11758; T. Pons, H.T. Uyeda, I.L. Medintz, H. Mattoussi, J. Phys. Chem. B 110 (2006) 20308]. Good agreement with experiment is found for reasonable choices of the model input parameters.     

A study of sorption and decomposition of ozone on microfibrous filtering materials

Decomposition of ozone on commercial and pilot filtering microfibrous materials based on polymers, glass fibers, and carbonized polymeric fibers was studied. Original Russian Text A.I. Klimuk, L.A. Obvintseva, A.D. Shepelev, V.L. Kuchaev, M.P. Dmitrieva, E.N. Ushakova, A.K. Avetisov, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 4, pp. 593–597.     

Mass selective gas phase study of ClO, OClO, ClOO and ClAr by anion-ZEKE-photoelectron spectroscopy

Anion-ZEKE-photoelectron spectra of ClO-, OClO-, ClOO- and the van der Waals cluster ArCl- have been measured. Refined or new values for the electron affinity of ClO, OClO and ClOO have been found. The peak positions in these spectra are in very good agreement with former ClO- and OClO- anion-photoelectron spectra (K. M. Gilles, M. L. Polak and W. C. Lineberger, J. Chem. Phys., 1992, 96, 8012) and a recent ArCl- anion-ZEKE spectrum (T. Lenzer, I. Yourshaw, M. Furlanetto, G. Reiser and D. Neumark, J. Chem. Phys., 1992, 110, 9578). The higher resolution of our anion-ZEKE-photoelectron spectrum of OClO- led to a refined assignment of the corresponding anion-photoelectron spectrum. In addition, a strong difference in the relative intensities of the vibrational peaks has been found in the anion-ZEKE-spectrum of OClO- in comparison with the anion-photoelectron spectrum. For the first time, mass selective spectroscopic information has been obtained for ClOO. The strong similarity to the ArCl- spectrum indicates a weakly bound van der Waals cluster Cl.O2. Binding energies of the anion, neutral ground and neutral excited state could be deduced. These are in good agreement with the electron affinities of Cl and ClOO, but differ from theoretical values (K. A. Peterson and H. J. Werner, J. Chem. Phys., 1992, 96, 8948) by a factor of 4.5 and from thermochemically determined values (J. M. Nicovich, K. D. Kreutter, C. J. Shackelford and P. H. Wine, Chem. Phys. Lett., 1991, 179, 367 and S. Baer, H. Hippler, R. Rahn, M. Siefke, N. Seitzinger and J. Troe, J. Chem. Phys., 1991, 95, 6463) by a factor of 9.