Change in electrophoretic mobility of HL-60RG cells by apoptosis

We measured the electrophoretic mobilities of HL-60RG cells and their apoptotic cells triggered by Actinomycin D as a function of the ionic strength of the suspending medium at pH 7.4. Both types of cells showed negative mobilities. The apoptotic HL-60RG cells exhibited larger mobility values in magnitude than intact HL-60RG cells in the whole range of the electrolyte concentration measured. The obtained data were analyzed via a mobility expression for soft particles, that is, colloidal particles with ionpenetrable surface layers. The observed mobility difference between the intact and apoptotic HL-60RG cells was found to be due mainly to the difference in friction exerted by the cell surface layers on the liquid flow around the cells between these two types of cells rather than the difference in charge density in their surface layers. A possible explanation for this mobility change by apoptosis is given.     

Preparation of Realgar Nanoparticle Suspension and Its Inhibition Effect on the Proliferation of Human Myelocytic Leukaemia HL-60 Cells

Realgar (As₄S₄) has recently been proved effective in the treatment of leukaemia in clinical trials. However, the poor solubility of realgar makes it difficult to conduct mechanistic study in cellular level. In this work, we prepared realgar nanoparticle (RNP) suspension and examined its effect on the proliferation of human myelocytic leukaemia HL-60 cells. The average diameter of the particles was 143 nm and was stable against coalescence over a 15-month storage. The suspension inhibited cell proliferation dose-dependently at concentrations from 10 to 60 µM (As), a fact shedding light on the mechanism of realgar's clinical effectiveness against hematopoietic malignancies.     

人早幼粒白血病细胞HL-60胞内pH的31P核磁共振研究

建立了无损伤性测定HL-60细胞胞内pH的31P-NMR方法.细胞内无机磷(Pi)的化学位移对pH非常敏感,随pH变化而变化,通过测定其化学位移进而能间接确定细胞内的pH.HL-60细胞的31P核磁共振谱由Pi、ATP等的共振峰组成.根据Pi峰的化学位移对HL-60细胞内pH进行了测定.HL-60细胞内Pi峰的化学位移为5.78±0.01,计算得到细胞内pH值为6.16±0.01.31P核磁共振能在测定细胞胞内pH的同时,观测到细胞内多种含磷小分子代谢物, 是一种无损伤研究细胞内pH及代谢的有效方法.     

气相色谱/氢火焰检测器检测HL-60细胞DNA中氧化损伤产物8-羟基鸟嘌呤的研究

用0．4mmol／LH2O2处理HL－60细胞株24h,采用气相色谱／氢火焰检测器（GC／FID）检测DNA氧化损伤产物8-羟基鸟嘌呤,并用气相色谱质谱仪选择性离子检测（CGC／MS－SIM）对其进一步鉴定。所用方法的平均回收率为81．7％,RSD小于5％。     

白血病细胞的31P核磁共振分析及用于无损伤游离镁离子测定

建立了无损伤性^31P-NMR研究细胞内代谢物的实验方法,并对人早幼粒白血病细胞HL-60的^31P-NMR谱中含磷小分子代谢物的谱峰进行了分析;通过测量HL-60的^31P-NMR谱中ATP的仅磷和β磷的化学位移差值,得出HL-60细胞内Mg^2 与ATP结合的复合物MgATP和整个ATP量的比值,计算得到HL-60细胞内游离Mg^2 浓度为0．264mmol／L。与其它分析方法相比,^31P-NMR测定细胞内游离Mg^2 浓度具有对细胞样品无损伤的优点。     

发夹型荧光分子探针用于DNA甲基化酶的活性分析及其在药物筛选中的应用

报道了一种基于发夹型荧光探针的甲基化酶活性的分析方法, 甲基化酶和相应的限制性内切酶的识别位点被设计在发夹型探针的茎部, 四甲基罗丹明(TAMRA)被连接在探针的5'端, 其荧光被连在3'端的熄灭基团4-(4'-二甲基对胺基偶氮苯)苯甲酸(DABCYL)所熄灭. 限制性内切酶可切割未发生甲基化修饰的探针, 导致探针的发夹结构遭到破坏, 引起TAMRA荧光信号的恢复. 根据荧光信号的恢复程度可实现对甲基化酶活性的分析. 在此基础上, 建立了一种简便、快速分析抗肿瘤药物对DNA甲基化酶活性的影响的方法, 为筛选针对基因甲基化异常引起的恶性肿瘤的治疗药物提供了一种新的思路和方法.     

A new daphnane diterpenoid from Excoecaria venenata with inhibitory effect on human leukaemia HL-60 cells

A new daphnane diterpenoid, venenatin (1), along with six known compounds, was isolated from the aerial parts of Excoecaria venenata. The structure of 1 was elucidated on the basis of extensive spectroscopic analysis. Compound 1 exhibited growth inhibitory effect on human leukaemia HL-60 cell line with IC₅₀ value of 28.10 μM.     

Effects of liposomal phophatidylserine on phagocytic uptake of liposomes by macrophage-like HL-60RG cells

The purpose of this work is to know the effect of surface properties of liposomes on their phagocytic uptake by macrophages. For this, liposomes were prepared by the Bangham technique from the mixture of phosphatidylcholine (PC) and cholesterol (Chol) incorporated either with phosphatidylserine (PS), phosphatidylethanolamine (PE) or phosphatidic acid (PA). The liposomes thus prepared had diameters in the range between 150 and 260 nm. Electric surface properties of the liposomes and the macrophages differentiated from HL-60RG cells were determined by measuring their electrophoretic mobilities. The phagocytic uptake of liposomes with different contents of PS, PE and PA by macrophage-like HL-60RG cells was investigated by measuring oxygen consumption associated with phagocytic uptake. The phagocytic activity was found to be the highest with the PC–Chol liposomes containing 7 mol% PS, but no significant effects were observed with PA- and PE-containing PC–Chol liposomes. As the uptake was independent of the electric surface property of liposomes, PS was concluded to be specifically important for phagocytic activity of macrophages.     

The toxic effects of organometals on the lands cycle in HL-60 cells

The concentration of free fatty acids within cells is mainly dependent upon the following enzyme activities: liberation by phospholipase A₂ (PLA₂), activation of free acids by acyl-CoA-synthetase and re-esterification by lysophospholipid acyltransferase (LAT). In many cell types, especially those of the haematopeotic system, this deacylation-reacylation cycle (‘Lands cycle’) plays an important role in the regulation of free fatty acid concentration, above all that of arachidonic acid. We have shown here that heavy-metal compounds affect this cycle mainly at two points and thereby lead to an increase of free fatty acids. On the one hand, organometals cause an inhibition of the reacylation of lysophospholipids; and on the other, the induction of PLA₂ activity produces the same result. All compounds investigated such as methylmercury chloride (MeHgCl), diethyltriethyl-, and trimethyl-lead chloride (Et₂PbCl₂, Et₃PbCl, Me₃PbCl) as well as trimethyltin chloride (Et₃SnCl) and di-t-butyltin dichloride (t-Bu₂SnCl₂) show at least one of these effects. In the case of Et₃PbCl, the use of PLA₂-inhibitors or pertussis toxin causes a drastic decrease in the amount of arachidonic acid liberated. These experiments demonstrate that the organometallic compounds inhibit the reacylation and/or stimulate the deacylation of fatty acids that are involved in many important biological or pathological mechanisms. The results suggest that in differentiated HL-60 cells the organometal compounds stimulate the Lands cycle by increasing the activity of the PLA₂, possibly via a signal-transduction mechanism, and this effect is intensified via an inhibition of reesterification.     

Dexamethasone Attenuates Oncostatin M Production via Suppressing of PI3K/Akt/NF-κB Signaling in Neutrophil-like Differentiated HL-60 Cells

Oncostatin M (OSM) plays a role in various inflammatory reactions, and neutrophils are the main source of OSM in pulmonary diseases. However, there is no evidence showing the mechanism of OSM production in neutrophils. While dexamethasone (Dex) has been known to exert anti-inflammatory activity in various fields, the precise mechanisms of OSM downregulation by Dex in neutrophils remain to be determined. Here, we examined how OSM is produced in neutrophil-like differentiated HL-60 cells. Enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot analysis were utilized to assess the potential of Dex. Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation resulted in OSM elevation in neutrophil-like dHL-60 cells. OSM elevation induced by GM-CSF is regulated by phosphatidylinositol 3-kinase (PI3K)/Akt/nuclear factor (NF)-kB signal cascades. GM-CSF stimulation upregulated phosphorylated levels of PI3K or Akt or NF-κB in neutrophil-like dHL-60 cells. Treatment with Dex decreased OSM levels as well as the phosphorylated levels of PI3K or Akt or NF-κB in neutrophil-like dHL-60 cells. Our findings show the potential of Dex in the treatment of inflammatory diseases via blocking of OSM.     

微量热法研究药物对肿瘤细胞的诱导分化作用

Sp-Octyl-(8-Chloroadenosine)-3',5'-Cyclophosphate (OCC), a newlysynthesized cAMP analog, strongly induces growth inhibition and differentiation in human promyelocytic leukemia HL-60 cells. The effect of OCC is dose-time dependent. By using the LKB2277 Bioactivity Monitor, we determined the heat production rate of HL-60 cells treated by OCC at different concentrations. It was found that the heat production rate of HL-60 cell treated by OCC gradually decreased to that of normal human neutrophiles.     

镓转铁蛋白与HL60细胞的结合

用¹²⁵I示踪法测定了不同形式的镓转铁蛋白(Ga_C-Tf, Ga₂-Tf, Ga_C-Tf-Fe_N)与HL60细胞的结合作用. 结果表明0 ℃、pH＝7.4时Ga_C-Tf, Ga₂-Tf和Ga_C-Tf-Fe_N均与细胞膜结合, 表观结合常数分别为(1.2±0.14)×10⁸, (1.1±0.19)×10⁸和(1.8±0.42)×10⁸ L/mol; 同时测定了¹²⁵I标记的脱铁转铁蛋白(apoTf)与HL60细胞的表观结合常数为(0.97±0.20)×10⁸ L/mol; HL60细胞的平均受体数为(4.8±0.11)×10⁵. 通过体外研究表明, 不同形式的镓转铁蛋白与受体的结合能力次序为apoTf≈Ga_C-Tf≈Ga₂-Tf＜Ga_C-Tf-Fe_N.     

Synthesis and Characterization of C60-Containing Poly（ethylene oxide）

C60-Containing poly(ethylene oxide) (PEO) was synthesized by a new method.Molecular structural characterization for the polymers was presented by ^1H-NMR, infrared and UV-Vis spectra.     

水溶性C60衍生物的电化学合成及表征

通过电化学方法合成了一种具有良好水溶性并能在水及空气中长期稳定存在的C₆₀衍生物,经电泳实验证实该衍生物带负电荷。红外光谱及近红外光谱显示该水溶物有稳定键合的CO和OH基,所以表现出强亲水性。在可见区(从420nm到700nm)有非常宽的发光谱带,这是由于Jahn-Teller效应以及C₆₀和OH基之间的相互作用引起的。     

含C60的苯乙烯和丙烯酰胺共聚物的合成与表征

在高分子领域中,C60的高分子化一直是C60材料化的一个重要途径.迄今为止,制备含C60高分子的方法有以下几种:(1)采用自由基引发剂、阴离子引发剂或阳离子引发剂引发C60与烯类单体共聚[1,2];(2)对C60进行表面修饰,引入可聚合官能团,合成含C60的单体,随后聚合成含C60的高分子[3];(3)制备出带有功能基团的高分子前体,再通过功能化反应将C60引入高分子链[4～9].     

High-Speed Large Scale Chromatographic Purification of Plasmid DNA with a Novel Giant-Pore Stationary Phase

A rigid spherical giant-pore poly (glycidyl methacrylate-co-ethylene dimethacrylate) matrix has been prepared by radical suspension–polymerization on the basis of a novel porogenic mode using superfine particles of calcium carbonate as a solid porogen. Scanning electron microscopy reveals that the bead has pores as large as 10 μm. The hydrodynamic properties show that this polymeric material has good strength and a low back pressure of 1.0 MPa at a flow velocity of 3,000 cm h⁻¹. After being modified to be an anion-exchange material, high dynamic binding capacity of plasmid DNA of above 1,000 μg plasmid per mL of bed by a column of this material, could be obtained comparing to the 150 μg plasmid per mL of bed with a Q-Sepharose FF column at the same flow rate. Large-scale preparative plasmid separations (2–20 mL) from cell lysate were investigated. A 75% yield and 94.9% purity of SC plasmid DNA were obtained by a 20 mL column of giant-pore beads at a flow rate of 600 cm h⁻¹.     

Synthesis and Characterization of a Squarylium Cyanine Dye with Two [60]Fullerene Units

Fullerene derivatives containing two or more [60]fullerene units may exhibit interesting properties1. There have been reported a limited number of organofullerenes with two or more cages, and the synthetic procedures are an oxidative coupling reaction of terminal alkynes2, bifunctional cycloaddition reactions such as diazo compounds3, dienes4 or (-amino acids and aldehydes 1, 3-dipolar cycloaddtion5, cyanogen di-N-oxide as a double 1, 3-dipole6. Oxo- and methylene-bridged [60]fullerene dimers …     

C_(60)吡咯烷聚硅氧烷的合成及其在毛细管气相色谱中的应用

通过Ｃ６０吡咯烷衍生物（Ⅰ）和甲基二氯硅烷的硅氢加成产物和端羟基甲基硅油缩合,合成了首例Ｃ６０衍生物气相色谱固定相——Ｃ６０吡咯烷聚硅氧烷（Ⅱ）,并首次研究了它在毛细管气相色谱中的应用。结果表明,该固定相可有效分离多环芳烃,对高沸点的邻苯二甲酸二酯类化合物有很好的分离效果,且有很好的热稳定性,３６０℃时基线漂移量为５ｆＡ。     

豆荚型纳米材料C60@SWNTs的制备和表征

通过气相扩散的方法将C60填入单壁碳纳米管（SWNTs）,制备了豆荚型纳米材料C60@SWNTs,并利用高分辨电子显微镜（HRTEM）和拉曼光谱（Raman spectra）对其进行了表征.结果均证明C60以较高的比例填充入单壁碳纳米管中.HRTEM结果表明,填入单壁碳纳米管的C60之间的距离与面心立方C60晶体中C60之间的距离有细微的差别,说明C60分子与SWNTs间存在弱的范德华相互作用.此外,还观察到在电子束的照射下,C60在SWNT中两两聚合的现象.