高三尖杉酯碱抗乳腺癌作用的初步研究

目的:研究药物高三尖杉酯碱是否对人乳腺癌MDA-MB-453细胞具有生长抑制和诱导凋亡作用,以挖掘研发治疗乳腺癌的新药物.方法:常规培养人乳腺癌MDA-MB-453细胞,根据高三尖杉酯碱浓度分为分为组和高三尖杉酯碱10、20、40、60、80、120、160μg/mL组,其中20μg/mL组为小剂量组,80μg/mL组为中剂量组,120 μg/mL组为大剂量组.采用台盼蓝染色、MTT比色法和透射电镜分析研究高三尖杉酯碱对于人乳腺癌细胞的作用.结果:台盼蓝染色结果显示大、中、小剂量组的活细胞率依次由小到大;MTT比色法显示各浓度药物作用在24、48和72 h均能显著抑制人乳腺癌MDA-MB-453细胞的增殖(P<0.05,P<0.01).电镜观察发现,高三尖杉酯碱作用后的人乳腺癌MDA-MB-453细胞染色体断裂,核分裂成碎片,细胞内形成凋亡小体.结论:高三尖杉酯碱对于乳腺癌MDA-MB-453细胞具有一定的抑制作用和诱导凋亡的作用,应予进一步研究.     

高三尖杉酯碱抗乳腺癌作用的初步研究

目的:研究药物高三尖杉酯碱是否对人乳腺癌MDA-MB-453细胞具有生长抑制和诱导凋亡作用,以挖掘研发治疗乳腺癌的新药物.方法:常规培养人乳腺癌MDA-MB-453细胞,根据高三尖杉酯碱浓度分为分为组和高三尖杉酯碱10、20、40、60、80、120、160μg/mL组,其中20μg/mL组为小剂量组,80μg/mL组为中剂量组,120 μg/mL组为大剂量组.采用台盼蓝染色、MTT比色法和透射电镜分析研究高三尖杉酯碱对于人乳腺癌细胞的作用.结果:台盼蓝染色结果显示大、中、小剂量组的活细胞率依次由小到大;MTT比色法显示各浓度药物作用在24、48和72 h均能显著抑制人乳腺癌MDA-MB-453细胞的增殖(P<0.05,P<0.01).电镜观察发现,高三尖杉酯碱作用后的人乳腺癌MDA-MB-453细胞染色体断裂,核分裂成碎片,细胞内形成凋亡小体.结论:高三尖杉酯碱对于乳腺癌MDA-MB-453细胞具有一定的抑制作用和诱导凋亡的作用,应予进一步研究.     

半合成三尖杉酯碱的抗肿瘤作用及毒性研究

三尖杉酯碱Harringtonine是从我国特有植物海南粗榧(Cephalotaxus hainanensisLi)中分离出的一种抗肿瘤有效成分。对多种动物移植性肿瘤有明显的抗肿瘤作用。临床已经证明该酯碱对多种急性非淋巴性白血病及慢性粒细胞白血病有较好疗效。由于三尖杉     

三尖杉酯碱和高三尖杉酯碱诱导人早幼粒白血病细胞的程序性死亡

体外实验证明2×1O^-7 mol·L^-1 三尖杉酯碱和 1O^-7 mol·L^-1高三尖杉酯碱与HL-60细胞作用 4 h，可诱导该细胞产生程序性死亡。提取细胞DNA进行琼脂糖凝胶电泳呈现典型的DNA 梯，同时出现细胞核染色体断裂、核固缩及细胞空泡样变等形态变化。并且在一定范围内具有作用时间和浓度依赖性，二者诱导HL-60细胞程序性死亡作用的强弱与其细胞毒作用平行。     

三尖杉酯碱正，负电荷脂质体在大鼠体内的分布

三尖杉酯碱（harringtonine,H)是从三尖杉属植物中分离到的抗肿瘤有效成分，对急性及慢性粒细胞白血病，急性单核细胞白血病及红白血病匀有肯定的疗效，但也具有毒性较大及易复发的缺点，脂质体可以改变多种药物在动物体内的组织分布，提高药物的选择性，增加疗效和降低毒性（4-6)，因而越来越受到重视，本文目的是比较三尖杉酸碱正，负脂质体（harringtonine positively and negatively charged liposome,HL( ),HL(-)和游离三尖杉酯碱（harrinmgtonine free-form ,HF)在动物体内的组织分布及它们的急性毒性，观察不同的三尖杉酯碱脂质体是否能提高H在某些组织中的分布量，能否促进H秀过血脑屏障及血睾屏障，为扩大H临床应用范围及临床合理用药提供依据。     

三尖杉酯碱和高三尖杉酯碱对肿瘤细胞Ⅳ型胶原酶的分泌及活性的影响

目的：植物来源的抗白血病药三尖杉酯碱和高三尖杉酯碱对肿瘤细胞增殖有显抑制，已成为急性粒细胞性自血病的首选药物之一：我们的研究还表明该药对肿瘤细胞的侵袭和运动也有明显抑制作用。为探讨其作用机理，进一步观察了该药对人纤维肉瘤HT-1080细胞Ⅳ型胶原酶的分泌及活性的影响。方法：用聚丙烯酰胺凝胶电泳法测定HT-1080细胞Ⅳ型胶原酶MMP-2和MMP-9的产生及活性。结果：三尖杉酯碱在0．001，0．01μg/ml浓度下对HT-1080细胞MMP-2和MMP-9的产生及活性均无明显影响。     

高三尖杉酯碱对白血病原癌基因bcl-2、c-myc、抑癌基因p15的影响

目的探讨高三尖杉酯碱对白血病治疗作用的机制。方法用细胞培养、DNA片段凝胶电泳、Western blot和cDNA阵列杂交等方法检测高三尖杉酯碱对白血病HL-60细胞凋亡及原癌基因表达的影响。结果高三尖杉酯碱使HL-60细胞、bcl-2蛋白表达明显较低,c-myc表达较弱,而p15表达较强。结论高三尖杉酯碱抑制HL-60细胞增殖、诱导其分化和凋亡,其机制可能与高三尖杉酯碱下调原癌基因bcl-2、c-myc及上调抑癌基因p15有关。     

微量液体克隆形成法体外检测三尖杉酯碱、高三尖杉酯碱对CFU—GM及L—CFU的细胞毒作用

基于琼脂半固体培养法和极限稀释微孔池培养法,建立了一种新的体外药敏检测体系——微量液体克隆形成法。并应用该体系检测了三尖杉酯碱(H)和高三尖杉酯碱(HH)对CFU—GM及L—CFU的细胞毒作用。结果提示:24h及168h作用法时,HH对CFU—GM以及L—CFU的细胞毒作用均大于H,H、HH对L—CFO的细胞毒作用选择性均大于CFU—GM,但HH的细胞毒作用选择性不及H;H、HH的TDI(Time—schedule Depne—dence Index),IC_(90-24h)÷IC_(-90-168h)分别为68、60,说明两药物均为细胞周期时相特异性药物;并对H、HH之间可能存在的同系物间的交叉耐药性作了探讨。     

三尖杉酯类生物碱对L615及P388白血病细胞cAMP含量的影响

实验证明,三尖杉酯类生物碱对某些动物移植性白血病和实体瘤有不同程度的疗效。在治疗剂量下,三尖杉酯碱能抑制肿瘤细胞有丝分裂,降低肝、脾和肿瘤组织的核酸含量,明显抑制DNA合成。三尖杉酯碱对白血病L1210杀伤动力学研究表明,它是一个细胞周期非特异性抗肿瘤药,但对S期细胞有强烈杀伤作用,对G_0期细胞也有一定影响。临床     

用改进逆流分配法分离三尖杉酯碱和高三尖杉酯碱

对三尖杉酯碱和高三尖杉酯碱混合物的分离利用经改进的逆流分配法，用经ｐＨ５缓冲液饱和的氯仿作流动相，经氯仿饱和的ｐＨ５磷酸氢二钠－枸橼酸作固定相，醋酸乙酯∶丙酮（６∶２．５）作展开剂，碱性硅胶板作薄层板，经对５批混合物进行分离，均分别获得三尖杉酯碱和高三尖杉酯碱的白色结晶。各项指标检查均符合标准。     

CAMPATH-1H (Cambridge University)

CAMPATH-1H, a T-cell-depleting, humanized monoclonal antibody, is under development by LeukoSite and ILEX for the potential treatment of chronic lymphocytic leukemia (CLL). In August 1998, ILEX completed enrollment of a pivotal clinical trial of CAMPATH-1H in the treatment of CLL. The study has enrolled 94 patients at 20 centers in the US and Europe. It is anticipated that achievement of the target response would result in a biologics license application being filed with the FDA in mid-1999. Preliminary unaudited results reported by one of the clinical sites were positive. Additional potential therapeutic areas include vasculitis and multiple sclerosis. Preliminary studies have also shown the antibody may reverse acute renal transplant rejection episodes and be useful in ex vivo purging of bone marrow to remove potentially malignant cells. The US FDA has granted Fast Track designation to CAMPATH. The product has orphan drug status.     

Histamine H(3) receptor (H(3)R) antagonists and inverse agonists in the treatment of sleep disorders

After the discovery and characterization of the H(3)R and H(4)R receptors, they have become widely anticipated as potential therapeutic agents in the treatment of sleep disorders. In preliminary studies, histamine H(3) receptor (H(3)R) antagonists and inverse agonists have demonstrated promise in the treatment of sleep disorders associated with excessive daytime sleepiness. This review article summarizes the current research in this area and characteristics of H(3)R and H(3)R antagonists and inverse agonists in development.     

(3H)Choline entry and (3H)acetylcholine formation in leech segmental ganglia.

Choline entry into the cells of segmental ganglia of the leech, Hirudo medicinalis was studied. Kinetic data obtained for two different choline concentration ranges suggest that there are two different Michaelis constants for the carrier-mediated choline entry, one about 860 μM and the other about 45 μM. The percentage of labelled choline transformed into acetycholine was considerably higher if the ganglia were incubated in 6 μM [³H]choline than in 250 μM [³H]choline. Hemicholinium-3 at 10 and 100 μM inhibited choline entry rate and diminished the percentage of labelled choline transformed into acetycholine. Removal of sodium from the incubating medium affected the choline entry to roughly the same degree at low and at high choline concentrations. The percentage of labelled choline transformed into acetylcholine did not diminish in the sodium-free medium. The results might be interpreted in terms of two choline entry systems in leech segmental ganglia. The choline entry system with the high affinity seems to be linked to acetylcholine synthesis.     

Bio-Transformation of (G-3H)-digitoxin and (G-3H)-digoxin by Digitalis purpurea

The biotransformation of (G- (3)H) digitoxin and (G- (3)H) digoxin has been studied in a strain of Digitalis purpurea in which cardenolides of the B series were predominant. A direct method of introducing the tritiated glycosides into the plant is described and the conversions monitored at intervals during the subsequent 6 weeks. Conversion of labelled digitoxin to purpurea glycosides A and B, gitoxin and gitaloxin occurred. Of particular interest was the conversion of digitoxin to the digitalose - containing glycosides, strospeside and verodoxin. Digoxin, an exogenous glycoside to D. purpurea, was glycosylated to desacetyl lanatoside C; there was some conversion to B and E series glycosides but only minimal formation of A series cardenolides.     

PHARMACOLOGICAL ACTIONS OF THE COENZYMES NAD(H) AND NADP(H) ON THE RAT ANOCOCCYGEUS MUSCLE

1. The pharmacological actions of the oxidized and reduced forms of nicotinamide-adenosine dinucleotide (NAD, NADH) and nicotinamide-adenosine dinucleotide phosphate (NADP, NADPH) were studied on rat isolated anococcygeus muscles. 2. The actions of the two nucleotides were different, but there were no apparent qualitative differences between the oxidized and reduced forms of each. 3. In fully relaxed anococcygeus muscles, NADP(H) produced transient contractions that were subject to desensitization, but NAD(H) had no effect. 4. NADP(H) slightly enhanced contractions elicited by noradrenergic nerve stimulation. In contrast, noradrenergic contractions were inhibited by NAD(H). NADH reduced the stimulation-induced release of noradrenaline, but enhanced contractions elicited by exogenous noradrenaline. 5. In anococcygeus muscles partly contracted with guanethidine, NAD(H) produced a further sustained increase in tone; in contrast, NADP(H) mainly produced transient relaxations to which there was immediate desensitization. 6. Relaxations of anococcygeus muscle elicited by nitrergic nerve stimulation were not affected by NAD. In contrast, NADP(H) reduced them. 7. The actions of NAD(H) were generally the same as those of adenosine and can be attributed to activation of P₁-purinoceptors since they were blocked by the selective antagonist 8-sulphophenyl-theophylline. 8. The actions of NADP resembled those of the P₂-purinoceptor agonist ATP to some extent, but there were some differences. As suggested by others, NADP may act on a unique receptor.     

Bio-Transformation of (G-3H)-Digitoxin and (G-3H)-Digoxin by Digitalis purpurea.

The biotransformation of (G- (3)H) digitoxin and (G- (3)H) digoxin has been studied in a strain of DIGITALIS PURPUREA in which cardenolides of the B series were predominant. A direct method of introducing the tritiated glycosides into the plant is described and the conversions monitored at intervals during the subsequent 6 weeks. Conversion of labelled digitoxin to purpurea glycosides A and B, gitoxin and gitaloxin occurred. Of particular interest was the conversion of digitoxin to the digitalose - containing glycosides, strospeside and verodoxin. Digoxin, an exogenous glycoside to D. PURPUREA, was glycosylated to desacetyl lanatoside C; there was some conversion to B and E series glycosides but only minimal formation of A series cardenolides.