共查询到20条相似文献,搜索用时 46 毫秒
1.
PIC-BE诱导K562/ADM细胞凋亡及逆转其MDR的研究 总被引:6,自引:0,他引:6
β榄香烯吗素(PIC-BE)是抗癌新药β榄香烯的水溶性衍生物.采用人红白血病的多药耐药性(MDR)细胞株K562/ADM作为实验模型,观察PIC-BE对K562/ADM细胞的生长抑制和凋亡诱导作用,并进而研究其对该细胞MDR的可能影响.结果显示:(1)K562/ADM细胞对ADM具有明显的抗性,与K562细胞相比,抗性倍数约为40倍,而两者对PIC-BE的IC50接近,无显著差异;(2)PIC-BE(10.0~30.0μg/ml)对K562/ADM细胞具有明显的生长抑制和凋亡诱导作用,两种作用的强度在一定的范围内均具药物浓度和作用时间依赖性;(3)低毒剂量PIC-BE(10.0μg/ml)与ADM(4.0μg/ml)联合应用,可显著增强ADM对该细胞的生长抑制和凋亡诱导作用,升高细胞内ADM的浓度,降低该细胞对ADM的IC50,使该细胞对ADM的抗性有数倍逆转.上述结果提示,PIC-BE不仅是一种有效的广谱抗肿瘤剂,而且也是一种有效的MDR逆转剂 相似文献
2.
以药物敏感型细胞株K562/S和耐药型细胞株K562/A02为对象.观察原癌基因Bcl-2的表达量在两种细胞中的差异,以及神经酰胺作为一个新的脂质第二信使诱导细胞凋亡的能力,并利用酪氨酸激酶抑制剂genistein,酪氨酸磷酸酯酶抑制剂vanadate,观察酪氨酸可逆磷酸化与细胞凋亡间的关系.结果显示:在K562/A02中Bcl-2的表达量明显高于K562/S;外源性神经酰胺能成功地诱导K562/S,K562/A02细胞凋亡,凋亡细胞具有典型的形态学改变和DNA“Ladder”形成,FCM检测出现凋亡细胞峰,但在同样的诱导条件下,K562/S细胞凋亡明显高于K562/A02细胞.FCM检测genistein能显著改变这两种细胞生长周期,但细胞阻滞于G2/M期,便对神经酰胺诱导的细胞凋亡无明显作用,vanadate单独对细胞地明显作用,但与神经酰胺共同作用能明显提高细胞凋亡率.以上结果表明在药物诱导的细胞调亡中Bcl-2基因起重要作用,神经酰胺能诱导K562/S和K562/A02细胞调亡. 相似文献
3.
IL—3对人红白血病细胞株珠蛋白基因表达的影响 总被引:2,自引:0,他引:2
运用RT-PCR等方法研究了白细胞介素-3(IL-3)对人类红白血病细胞株(K562细胞)内珠蛋白基因表达的影响,结果显示,K562细胞在诱导前,不能表达β-珠蛋白基因,用IL-350u/ml诱导K562细胞3d和5d后,可检测到β珠蛋白基因的转录产物,而α珠蛋白基因和γ-珠蛋白基因在诱导前后无明显变化,同时,用苯肼当色细胞的方法检测到:K562细胞在诱导前蓝染细胞数极少,IL-3诱导K562细胞 相似文献
4.
细胞凋亡过程中c-erbB-2基因的表达 总被引:5,自引:2,他引:3
据文献报道c-erbB-2可以介导细胞凋亡,为检验这一结论是否具有普遍性,用5-氟尿嘧啶(5-Fu)诱导小鼠成纤维细胞NC3H10,TC3H10及人乳腺癌细胞MCF-7的凋亡.用Northern印迹法检测c-erbB-2的表达状况.结果显示:c-erbB-2基因表达在5-Fu作用6h开始降低,12h降低更为明显.作用24~48h出现细胞存活率下降,DNA梯状断裂及细胞周期凋亡峰等凋亡典型现象.实验结果并不支持c-erbB-2可介导细胞凋亡的观点.该基因在细胞凋亡过程中有何作用尚待探讨. 相似文献
5.
用重组痘苗病毒表达pGHcDNA的研究 总被引:4,自引:0,他引:4
构建了含有pGHcDNA的重组痘苗病毒,用ELISA证明该重组病毒在被感染的h143细胞中,可表达出猪生长激素并将之分泌到培养基中,表达量约为1.05μg/10^6细胞(24h),用定位免疫化学法进一步证明该病毒可感染小鼠并在小鼠体内表达pGHcDNA,同时还构建了含双拷贝pGHcDNA的重组痘苗病毒,并证明其pGH表达量比单拷贝重组病毒有明显提高,约为1.50μg/10^6细胞(24h) 相似文献
6.
氧化诱导K_(562)细胞凋亡机制的初步探讨 总被引:7,自引:0,他引:7
以过氧化氢(H2O2)诱导人慢性髓细胞白血病(K562)细胞为凋亡模型,采用流式细胞仪(flowcytometry,FCM)和激光共聚焦扫描显微镜(laserconfocalscanningmicroscopy,LCSM)研究细胞凋亡,形态观察出现核固缩,核碎裂及凋亡小体等典型凋亡特征.DNA电泳图谱出现“Ladder”.FCM检测在G0/G1峰前出现一低DNA含量的凋亡峰.LCSM显示凋亡细胞c-Fos.c-Jun和NFκB表达量均有不同程度的增加.该结果提示上述三种转录因子可能参与氧化诱导凋亡过程中基因的调控作用. 相似文献
7.
构建了含有pGHcDNA的重组痘苗病毒,用ELISA证明该重组病毒在被感染的h143细胞中,可表达出猪生长激素并将之分泌到培养基中,表达量约为1.05μg/10 ̄6细胞(24h)。用定位免疫化学法进一步证明该病毒可感染小鼠并在小鼠体内表达pGHcDNA。同时还构建了含双拷贝pGHcDNA的重组痘苗病毒,并证明其pGH表达量比单拷贝重组病毒有明显提高,约为1.50μg/10 ̄6细胞(24h)。 相似文献
8.
灵芝多糖对人脐血LAK细胞活性的影响 总被引:2,自引:0,他引:2
本文研究了灵芝多糖(GLP)对人脐血LAK(CB—LAK)细胞活性的影响,结果发现,单独GLP能刺激人脐血单个核细胞(CBMC)增殖,但不能诱导LAK活性,当与50u/mlrIL—2伍用时,可增殖CB—LAK细胞诱导活性,不同剂量GLP(0.5—100μg/ml)影响作用不同,以10μg/ml浓度最好.在不同浓度rIL—2(10—100u/ml)诱导CB—LAK细胞过程中加入GLP(10μg/ml),可明显提高细胞增殖能力,减少rIL—2用量。GLP亦能促进效应阶段CB—LAK细胞对Raji肿瘤靶细胞的杀伤作用(P<0.001)。由此看出,GLP具有增强CB—LAK细胞活性的作用,是一很好的生物反应调节剂(BRM),有必要进行深入的研究。 相似文献
9.
黄芪多糖和白细胞介素2对LAK细胞毒活性的调节作用 总被引:5,自引:0,他引:5
采用扶正中药黄芪的有效成分黄芪多糖(APS)和不同来源的白细胞介素2的伍用,探讨其对LAK细胞毒性的调节作用,乳酸脱氢酶释放法(LDH)测定LAK细胞毒性的实验结果表明:APS自身具有增强LAK细胞毒性的作用,有效剂量范围为1μg/ml ̄100μg/ml;LAK细胞发挥细胞毒活性伍用一定剂量的白细胞介素2;APS(10μg/ml)和IL-2(500μ/ml)对LAK细胞毒性具有非常显著的协同增强作 相似文献
10.
鼻咽癌细胞对HA的粘附作用及微丝的共聚焦显微镜观察 总被引:2,自引:0,他引:2
本文研究了人鼻咽癌上皮细胞系CNE-2Z对透明质酸(HA)的粘附作用及其粘附后微丝的改变,结果表明,鼻咽癌细胞粘附的OD值随HA浓度的升高而升高,300μg/ml、1250μg/ml组与对照组比较有极显著性意义,P<0.01;癌细胞粘附的OD值随培养时间延长而升高,240min组及120min组与60min组比较有极显著性意义,P<0.01。LSM观察HA浓度为300μg/ml时培养4h和24h的癌细胞微丝的分布明显不同,培养4h的癌细胞呈圆形,微丝均匀地分布于胞浆内;培养24h的癌细胞呈不规则形,微丝主要分布于与HA的粘附面上。上述结果提示HA可促进鼻咽癌细胞粘附,癌细胞与HA结合后可诱导MF重组 相似文献
11.
12.
13.
Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
14.
15.
16.
17.
RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
18.
JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
19.
肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
20.
H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献