硒化壳聚糖诱导NB4细胞凋亡及周期阻断作用

为研究硒化壳聚糖对NB4细胞的凋亡及周期阻断作用,用流式细胞法观察了药物对细胞的诱导凋亡及周期阻断作用。结果表明,硒化壳聚糖作用NB4细胞24 h,可剂量依赖性地诱导细胞凋亡并使G0—G1期细胞增多。提示硒化壳聚糖可诱导细胞凋亡,并对NB4细胞周期有特异性阻断作用。     

硒化壳聚糖抗K562细胞的实验研究

用MTT法和AO/EB荧光染色法观察了硒化壳聚糖对K 562肿瘤细胞株生长的影响。结果发现,硒化壳聚糖可有效地抑制K 562细胞生长,并呈量效、时效关系。经硒化壳聚糖作用后的细胞可明显出现核固缩、碎裂等凋亡形态改变。硒化壳聚糖可诱导K 562细胞凋亡,抑制其生长。     

硒化壳聚糖抑制人早幼粒白血病细胞增殖的研究

为探讨硒化壳聚糖对体外培养人早幼粒白血病细胞增殖的抑制作用,用SRB法和集落形成法检测了药物对细胞增殖的抑制作用,流式法检测了细胞周期阻断作用。结果表明,25、50、100mg／L硒化壳聚糖作用HL60细胞48h对细胞有增殖抑制作用（P〈0．01）;50、100mg／L硒化壳聚糖作用细胞48h后,G0／G1期细胞数较对照组增加了14．9％-22．0％（P〈0．05）,S期细胞减少了14．3％～20．1％（P〈0．05）。可见硒化壳聚糖对人早幼粒白血病细胞增殖具有抑制作用。     

硒化壳聚糖对K 562和K 562/ADM作用的比较研究

应用MTT法和细胞集落形成率法观察了硒化壳聚糖对K562和K562／ADM肿瘤细胞株生长的影响，结果发现硒化壳聚糖可有效地抑制两种K562细胞生长，呈量效关系。同等剂量的硒化壳聚糖对K562细胞的作用强度高于对K562／ADM细胞。硒化壳聚糖对耐药的细胞株可产生抑制作用，若与化疗药合用则可减慢甚至部分逆转临床上K562细胞耐药性的发生。     

单独和合用硒化壳聚糖与阿霉素对K562细胞作用的研究

应用MTT法和AO／EB荧光染色法观察单独和合用硒化壳聚糖与阿霉素对K562细胞株的影响,结果发现硒化壳聚糖和阿霉素均可有效地抑制K562细胞生长。且两药联合使用效果更佳。硒化壳聚糖可诱导细胞凋亡。两药合用诱导细胞凋亡效果更好。     

气相色谱串联四极杆质谱法对富硒包菜汁中硒甲基硒半胱氨酸与硒蛋氨酸的测定

建立了一种快速分析富硒包菜汁中硒甲基硒半胱氨酸和硒蛋氨酸含量的方法。以氯甲酸乙酯作衍生化试剂,利用串联质谱技术在多离子监测模式下对衍生物进行GC-MS/MS测定。方法的线性范围为0.01～25 mg/L,线性相关系数r≥0.9988;方法检出限分别为硒甲基硒半胱氨酸（met-Se-cys）4μg/L、硒蛋氨酸（Se-met）2μg/L;met-Se-cys的方法回收率为82%～97%,RSD小于6.3%,Se-met的方法回收率为100%～109%,RSD小于7.5%。结果表明该方法简单、快速、准确,并能有效排除基质的干扰,适合于食品中硒甲基硒半胱氨酸和硒蛋氨酸的定性定量分析。     

荧光猝灭法测定壳聚糖含量

在pH 6.3的NaH2PO4-Na2HPO4缓冲溶液中,壳聚糖对荧光素的荧光强度具有明显的猝灭作用,且在一定浓度范围内,其猝灭程度与加入的壳聚糖浓度成线性关系,据此建立了一种新的测定壳聚糖含量的荧光猝灭分光光度法。该方法的回归方程为ΔF=64.02+42.28ρ(mg/L),R2=0.9942,线性范围为0.50~10.0 mg/L,检出限为0.27 mg/L。样品测定的RSD为4.5%(n=6),平均回收率为99.3%。采用该方法可测定复杂样品中的壳聚糖含量。     

硒化聚甘露糖醛酸的合成及抗阿尔茨海默症细胞氧化与凋亡

以聚甘露糖醛酸为原料, 采用先磺化、 再硒化的方法合成了硒化聚甘露糖醛酸, 产率为54%, 产物硒含量为437.25 μg/g. 在2.5 μmol/L硒浓度下, 硒化聚甘露糖醛酸促细胞生长能力达到最适范围, 能保护细胞免受过氧化氢损伤, 显著提高阿尔茨海默症(AD)模型细胞N2a-APP695-sw中的超氧化物歧化酶和谷胱甘肽过氧化物酶的活性, 降低细胞内活性氧自由基, 增加线粒体膜电位, 抑制细胞色素C的释放, 在促进Bcl-2表达的同时抑制Bax的表达, 从而具有抑制AD细胞凋亡的功能. 硒化聚甘露糖醛酸也能抑制AD病理相关蛋白BACE1和APP的表达. 结果表明, 硒化聚甘露糖醛酸在抗AD方面具有潜在的应用前景.     

FITC标记重组灵芝免疫调节蛋白(rLz-8)在NB4细胞中的动态定位

实验发现, 重组灵芝免疫调节蛋白(rLz-8)可直接杀伤人急性早幼粒细胞白血病细胞株NB4. 利用异硫氰酸荧光素(FITC)标记rLz-8, 其相关的活性实验结果和晶体结构分析都表明, FITC没有影响rLz-8已知生物学功能. 通过激光共聚焦显微镜观察FITC-rLz-8在NB4细胞内的动态过程发现, FITC-rLz-8可识别细胞膜上的受体, 并可进入细胞质, 并最终富集在细胞核区域内. Annexin V-FITC双染检测结果显示, rLz-8对NB4细胞杀伤作用的可能机制是对NB4细胞凋亡的诱导作用, 在一定浓度范围内, 剂量与凋亡诱导率成正相关. 因此rLz-8能够诱导肿瘤细胞NB4发生凋亡的亚细胞学机制可定位在细胞核上.     

磺化低聚壳聚糖的制备及其阻垢性能的研究

低聚壳聚糖和2,3-环氧丙磺酸钠开环接枝制得磺化低聚壳聚糖(SCS),其磺化度为0.77,用红外(FT-IR)光谱、核磁共振(1H NMR)氢谱进行了SCS产物结构表征。利用静态阻垢法对SCS阻硫酸钙和阻磷酸钙性能进行评价,当[Ca2+]为1900 mg/L,[SO42-]为4560 mg/L,SCS用量为32mg/L时,对硫酸钙的阻垢率能够达到88%;当[Ca2+]为100mg/L,[PO43-]为5 mg/L,SCS用量为16mg/L时,对磷酸钙的阻垢率可达到84%。研究表明磺化低聚壳聚糖是一种性能优异的绿色阻垢剂。     

微波消解-原子荧光光谱法分析肺癌患者全血中硒

目的探讨肺癌患者血样中硒含量的变化。方法采集肺癌组和对照组血样,用硝酸、过氧化氢混合液微波消解样品,采用原子荧光光谱法测定血样中硒的含量。结果肺癌组和对照组硒平均质量浓度分别为0.087、0.123 mg/L。结论肺癌患者血样硒含量明显降低,缺硒可能是导致肺癌高发的重要因素。     

Fabrics and papers modified with analytical reagents for the test determination of selenium(IV) and tellurium(IV)

It is shown that Malachite Green and Crystal Violet immobilized on viscose fabrics can be used as reagents for the rapid determination of selenium(IV) and tellurium(IV). Selenium is determine by the color intensity of ion associates formed by the reagents with the triiodide ion formed upon the reduction of selenium(IV) with potassium iodide and tellurium, by the color intensity of reagent ion associates with telluromolybdic heteropoly acid. The analytical ranges for selenium and tellurium(IV) were 0.005–0.5 and 0.01–0.1 mg/L upon passing 20 and 100 mL of a test solution through the indicator matrix, respectively. The duration of analysis does not exceed 15–20 min. The relative standard deviation is 50%. Test strips were proposed for determining 0.1–100 mg/L selenium(IV) and 1–1000 mg/L tellurium(IV) by the length of the colored zone. The determination of selenium(IV) is based on the oxidation of 4-nitrophenylgydrazine to its diazonium salt and salt interaction with naphthylamine chemically immobilized on paper with the formation of a red azo compound. The determination of tellurium(IV) is based on its reaction with Bismuthol II immobilized on a paper.     

分光光度法测定浙贝母中不同价态的硒含量

基于３，３＇－二氨基联苯二胺对Ｓｅ＾４＋的选择性测定，同时选择用２ｍｏｌ／Ｌ盐酸将Ｓｅ＾６＋定量还原为Ｓｅ＾４＋，测定了浙贝母中不同价态的硒含量。本法测Ｓｅ＾４＋回收率大于９３％，测Ｓｅ＾６＋回收率大于９５％，变异系数均小于５％，检出限为０．０２ｍｇ／Ｌ。     

2,3,5,4'- tetrahydroxystilbene-2-O-β-D-glycoside biosynthesis by suspension cells cultures of Polygonum multiflorum Thunb and production enhancement by methyl jasmonate and salicylic acid

Friable calli of Polygonum multiflorum Thunb have been induced in MS medium supplemented with 6-benzylaminopurine (6-BA) and kinetin (KT). Suspension cultures were initiated from friable calli by inoculating calli in liquid MS medium in shake flasks in the dark and 25 °C on an orbital shaker at 100 rpm. The maximum dry weight (DW, 7.85 g/L) and 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glycoside (THSG, 56.39 mg/L) of suspension cells was obtained in MS medium after 16 days culture. Both methyl jasmonate (MeJA) and salicylic acid (SA) could increase THSG production. The most appropriate concentration of MeJA was 100 μmol/L in MS medium, in which concentration THSG content reached the maximum value of 147.79 mg/L, which represented a 162.36% increase compared to that of the control (56.33 mg/L). The most appropriate concentration of SA was 125 μmol/L in MS medium, at which concentration THSG content reached its maximum value of 116.43 mg/L, a 106.69% increase compared to that of the control (56.33 mg/L).     

Differential pulse polarographic determination of selenium(IV) in whole blood using the catalytic hydrogen wave

The selenium content in blood was determined using the hydrogen catalytic peak. This peak at -1.1 V was obtained in the presence of selenium and molybdenum at pH values of 1-4 in different buffers. For the determination of selenium, the Mo(VI) concentration has to be approximately 100-200 times higher than the selenium present. The linear domain range of selenium is 1x10(-6)-5x10(-9) M. The interference of zinc is eliminated by the addition of EDTA at pH 3.5 acetate buffer. The method was applied to 1.0 ml of digested blood, and 620+/-44 mug l(-1) Se and 7.15 mg l(-1) Zn could be determined with a 90% (n=6) confidence interval.