去铁胺对K562细胞多药耐药基因MDR1及核因子κB表达的影响

目的 探讨去铁胺对柔红霉素（DNR）诱导多药耐药基因MDR1及核因子KB（NFκB）表达的影响，初步了解NFKB与MDR1表达、细胞内铁代谢的关系。方法 以DNR单用或联合应用25μmol／L去铁胺（DFO）为处理因素作用于人红白血病细胞株K562，应用RT-PCR法、流式细胞分析技术分别检测对照组、DNR组和DNR＋DFO组K562细胞MDRlmRNA和P糖蛋白（PgP）的表达情况，同时采用免疫组织化学染色法检测NFKBκB表达及活性情况。结果 与对照组相比，DNR可同时诱导MDRlmRNA、Pgp表达和NFgB活化（P〈0．05）；25μmol／LDFO联合DNR可显著抑制DNR诱导的MDRlmRNA、Pgp的表达及NFKB的活化（P〈0．05）。结论 去铁胺可减少柔红霉素诱导的MDRl、PgP表达，其机制可能与铁剥夺后降低了柔红霉索诱导的K562细胞的氧化应激反应，进而影响NFκB的活化有关。     

四株人白血病多药耐药细胞系的建立及其生物学特性的初步研究

我们对人红白血病细胞株K562和人早幼粒细胞白血病细胞株HL－60应用高三尖杉酯破（HHT）或长春新碱（VCR），采用反复短期暴露法，并逐渐增加HHT和VCR的浓度，成功地建立了K562／VCR、K562／HHT、HL－60／VCR和HL－60／HHT四株具有高度耐药性的多药耐药（MDR）细胞系。免疫组织化学染色显示，K562／VCR、K562／HHT及HL60／VCR三株MDR细胞系有卜糖蛋白（Pgp）的高度表达，而HL－60／HHT细胞系没有pgP的表达。四株MDR细胞系均未见有多药耐药相关蛋白（MRP）的表达。5μg／ml异搏定和50μg／ml红霉素都能部分逆转K562／VCR、K562／HHT和HL－60／VCR三株MDR细胞系的耐药性，但其对HL－60／HHT细胞系的耐药性几乎无逆转作用。四株MDR细胞系与其相应敏感细胞系相比，前者对DNR的摄取均减少，外排均增加。2．5～10μg／ml异搏定能增加K562／VCR、K562／HHT和HL－60／VCR三株MDR细胞系对DNR的摄取量和滞留量，且其作用随异搏定浓度的增加而增强，但50～200μgn／ml红霉素不能增加它们对DNR的摄取量和滞留量。上述浓度异搏定或红霉素均不能增加HL－60／HHT细胞系对DNR的摄取量和滞留量。     

去铁胺诱导K562细胞凋亡研究

目的：探讨铁螯合剂去铁胺（DFO）诱导白血病细胞凋亡的分子机制。方法：实验分为DFO组(终浓度分别为10、50、100 μM)、DFO+FeCl3（各10 μmol/L）组及空白对照组。用钙黄绿素检测K562细胞可变铁池。锥虫蓝活细胞拒染实验进行活细胞计数及细胞存活率测定;光镜形态学观察及流式细胞仪方法检测K562细胞凋亡;比色法检测caspase-3活性。结果：（1）DFO作用于K562细胞后,随培养时间延长及DFO浓度的增加,动态铁池降低,细胞生存率逐渐下降,凋亡率增加,显示一定的时间剂量依赖性;而DFO+FeCl3组细胞凋亡率与空白对照组差异无统计学意义。（2）50 μmo/L、100 μmol/L DFO作用于K562细胞24 h时,caspase-3酶活性升高明显,与对照组相比,差异有统计学意义(P<0.01);相关分析结果显示,K562细胞铁池的荧光改变与caspase-3活性变化呈负相关(r=-0.894, P<0.05)。结论：DFO诱导白血病细胞凋亡的作用可能与螯合细胞内铁,降低细胞可变铁池,激活caspase-3有关。     

槲皮素逆转K562、K562/ADM细胞耐药性研究

目的探讨槲皮素对K562、K562/ADM细胞热休克蛋白70信使核糖核酸(HSP70 mRNA)及多药耐药基因信使核糖核酸(MDR1 mRNA)表达的影响。方法采用MTT法检测槲皮素对K562细胞生长的抑制作用。逆转录聚合酶链反应(RT-PCR)检测多柔比星化疗前、后加入槲皮素K562细胞HSP70 mRNA及MDR1 mRNA的表达,及K562/ADM细胞在槲皮素作用后加多柔比星化疗两者的表达情况。结果1.槲皮素对K562细胞的生长抑制作用随浓度增加而增强。2.槲皮素作用后加多柔比星化疗组K562、K562/ADM细胞中HSP70 mRNA及MDR1 mRNA表达均显著降低。多柔比星化疗后加槲皮素组与多柔比星化疗组比较,K562细胞HSP70 mRNA、MDR1 mRNA表达均无显著性差异。结论槲皮素对白血病细胞生长具有抑制作用,并能下调HSP70 mR-NA及MDR1 mRNA表达。槲皮素能增加白血病细胞对多柔比星敏感性,逆转白血病细胞对多柔比星的耐药性。     

铁剥夺抗K562细胞的增殖作用及机制

目的观察铁剥夺对白血病细胞增殖的影响。方法以K562细胞作为人类白血病细胞株,台盼蓝染色,光镜下计数活细胞率;用四甲基偶氮唑蓝（MTT）法测A值（570nm）,绘制生长曲线;流式细胞术分析细胞周期变化。结果小剂量去铁胺（DFO）（12.5μmol/L）处理K562细胞时,生长曲线轻微变化,随时间延长和DFO剂量增加（25、50、100μmol/L）,细胞存活率明显下降,生长曲线高峰显著低于对照组。DFO的抗增殖活性为时间-剂量依赖型。用DFO（50、100μmol/L）处理K562细胞48和72h后,G0/G1期细胞数量增加,S期细胞数量减少,与对照组比较均有显著性差异（Pa〈0.001）。上述作用可被等浓度的三氯化铁抵消。结论铁剥夺具有抗白血病细胞增殖作用,剥夺细胞内铁,阻止细胞由G0/G1期进入S期可能是其机制之一。     

氯丙嗪对白血病细胞株K562/AO2多药耐药逆转作用的实验研究

目的研究氯丙嗪对阿霉素诱导的K562耐药细胞株(K562/AO2)多药耐药的逆转作用及机制,以便为临床应用提供实验依据.方法 (1)以四氮甲基唑蓝(MTT)法检测氯丙嗪的细胞毒性及其对K562/AO2细胞的耐药逆转作用;(2)以流式细胞术检测氯丙嗪处理前后K562/AO2细胞内柔红霉素(DNR)的蓄积量;(3)以逆转录聚合酶链反应(RT-PCR)法检测氯丙嗪处理前后后K562/AO2细胞中mdr-1 mRNA的表达水平.结果 (1)氯丙嗪在3 μg/ml时对K562/AO2增殖的抑制作用小,抑制率＜5%;(2)氯丙嗪明显增加DNR对K562/AO2的毒性作用(P＜0.05),耐药逆转倍数为1.901;(3)氯丙嗪可明显增强DNR在K562/AO2细胞内的蓄积(P＜0.05);(4)氯丙嗪对K562/AO2细胞mdr-1 mRNA的表达水平无影响.结论氯丙嗪通过增加K562/AO2细胞内DNR的蓄积显著提高 K562/AO2细胞对DNR的敏感性,其逆转白血病细胞多药耐药的机制与mdr-1基因无关,还有待进一步探讨.     

铁剥夺对K562细胞动态铁池的改变及凋亡相关基因表达的影响

目的探讨去铁胺(DFO)对白血病细胞K562动态铁池(LIP)、凋亡和凋亡相关基因表达的影响及其分子机制。方法实验分为DFO组、DFO 三氯化铁组及空白对照组,分别采用钙黄绿素检测K562细胞LIP改变、流式细胞术观察K562细胞凋亡和RT-PCR测定K562细胞c-myc、Rbb、ax mRNA表达。结果1.不同浓度的DFO作用于K562细胞后,随培养时间延长及DFO浓度增加,LIP降低,细胞生存率逐渐下降,显示一定的时间剂量依赖性。2.不同浓度的DFO作用于K562不同时间后,细胞凋亡增加,高于对照组(P<0.05);3.RT-PCR结果显示,DFO能明显上调c-myc、Rb和bax mRNA表达(P<0.05)。结论DFO可诱导K562细胞凋亡;其诱导K562细胞凋亡作用可能与其螯合细胞内铁,降低细胞LIP,上调细胞凋亡相关基因c-myc、Rb、bax mRNA表达密切相关。     

铁剥夺对白血病细胞凋亡相关基因表达的影响

目的　探讨去铁胺 (DFO)对白血病细胞K562凋亡相关基因表达的影响及其可能分子机制。方法　采用RT PCR法分析Rb及c myc基因在RNA水平变化。结果　DFO 50 μmol/L及 1 0 0 μmol/L作用于K562细胞 2 4h及 48h ,Rb及c mycmRNA水平较空白对照组增加 (P <0 .0 5) ,且以 1 0 0 μmol/L组增加明显。 结论　铁剥夺剂使K562细胞Rb及c mycmRNA表达增加可能是其诱导白血病细胞凋亡的机制之一。     

铁剥夺诱导HL-60细胞凋亡及对化疗药物诱导HL-60细胞凋亡的影响

目的 探讨铁剥夺对HL－60细胞凋亡及对化疗药物诱导HL－60细胞凋亡的影响。方法 HL－60细胞与不同浓度的铁螯合剂－去铁胺（DFO）、DFO加化疗药物、化疗药物、DFO加化疗药物及三氯化铁、三氯化铁共同培养6h、12h、24h、48h。通过测定细胞活力,观察细胞形态学变化,应用流式细胞仪检测和DNA凝胶电泳等方法观察细胞凋亡;通过亲和免疫组化方法检测c-myc基因表达,从而确定DFO及DFO与化疗药物联合应用对HL－60细胞的作用。结果 DFO单用可降低HL－60细胞活力、抑制HL－60细胞增殖、诱导HL－60凋亡,并可使c-myc基因表达增加,其作用强度随培养时间延长及DFO浓度增加而增加。DFO与化疗药物联合时,可增加化疗药物诱导HL－60细胞凋亡的作用。该作用可被等摩尔的三氯化铁抵消。结论 铁剥夺可影响HL－60细胞DNA的合成,诱导其凋亡,并提高HL－60细胞对化疗药物的敏感性。因此,铁剥夺可作为临床上白血病治疗或辅助治疗的方法之一,不适当补铁或升高血红蛋白将影响化疗疗效。     

铁剥夺和铁超负荷对白血病细胞株HL-60凋亡的影响机制

目的探讨铁剥夺和铁超负荷对白血病细胞株HL-60细胞凋亡的影响及其机制,为临床采用铁剥夺策略治疗或辅助治疗白血病提供理论依据。方法在HL-60细胞培养基中分别加入不同浓度的去铁胺(DFO)或三氯化铁(FeCl3),造成细胞内铁剥夺或铁超负荷状态,采取噻唑蓝(MTT)法、DNA原位末端标记染色法(TUNEL)、免疫组化法检测铁剥夺和铁超负荷状态下HL-60细胞活力、凋亡率、细胞色素C(Cyt C)阳性细胞率。结果 DFO组细胞活力呈明显下降趋势,凋亡率呈显著上升趋势;FeCl3组细胞活力和凋亡率与对照组相比呈下降趋势;DFO组细胞胞浆内Cyt C阳性细胞率与对照组相比明显升高;而FeCl3组细胞浆内Cyt C阳性细胞率与对照组相比无明显差异。结论铁剥夺可促进线粒体释放Cyt C,诱导HL-60细胞凋亡;铁超负荷对线粒体释放Cyt C无直接影响作用。     

早产儿视网膜病的危险因素分析及随访调查

研究早产儿视网膜病(retinopathy of prematurity,ROP)的发生率、高危因素、治疗与随访情况。方法对2005年7月-2007年12月温州医学院附属第一医院NICU收治的符合ROP筛查标准的早产儿,于生后2周开始由资深眼科医师开始行间接眼底镜检查眼底,并进行随访。结果434例早产儿中ROP的发生率为5.5%(24/434例),24例ROP中Ⅰ期19例,Ⅱ期3例,Ⅲ期2例。Ⅲ期阈值病变者行激光光凝治疗,全部患儿均恢复正常。对434例早产儿行单因素分析得出,胎龄、出生体重、住院时间、吸氧、吸氧浓度、吸氧时间、呼吸暂停、新生儿肺透明膜病(RDS)、肺表面活性剂(PS)的应用、机械通气、输血、光疗时间、感染与ROP的发生有相关性(P<0.05)。Logistic回归分析显示胎龄、出生体重、胎数、吸氧时间、光疗时间、代谢性酸中毒、母亲妊高症、颅内出血是影响ROP发生的主要因素。结论早产是ROP的根本原因,防治各种并发症、合理的氧疗是预防ROP的关键。建立完善有效的ROP筛查制度,早期发现、早期治疗ROP,可改善ROP的预后。     

术中判断肠活力三种方法的比较

术中准确地评价肠活力是外科医师面临的一个普遍问题。应用兔肠缺血模型，比较静脉荧光素、表面血氧测定和激光多普勒三种技术判断肠活力的精确性。结果：诊断效率静脉荧光素法为７８％，表面血氧测定为６８％，激光多普勒为９５％。后者精确度显著优于前二者，且操作简便、迅速，具有临床应用前景。     

Spectrum of clinical presentations of vein of Galen aneurysm

Aneurysm of the vein of Galen is a rare intracranial vascular malformation. It is known to have diverse manifestations and varying severity. Four cases with different modes of presentation and outcome are reported. A mortality of 50 per cent was encountered. Among the survivors, one had neurologic sequelae whereas the other had attained age-appropriate developmental milestones. The former was a rare case of spontaneous thrombosis of the aneurysm while the latter was a boy who underwent therapeutic embolization.     

Outcome of the Treatment of Inborn Errors of Metabolism

The use of specific dietary restrictions, cofactor administration, mobilisation of insoluble substances, environmental modifications, product replacement and selective enzyme inhibition are now established for the treatment of some inborn errors of metabolism. There is no generally accepted application for enzyme administration, cytopharmacology (manipulation of the cytoskeleton) or for cell transplantation except for bone marrow transplantation in disorders where the bone marrow is primarily at fault. The other uses of bone marrow transplantation which have been proposed require further evaluation. Results of recent research suggest that the scope of this approach is gradually being widened. There is also scope for development in the field of organ transplantation taking advantage of recent technical¹ and immunological progress. The treatment of inborn errors of metabolism by genetic modification is not yet on a practical clinical level; more laboratory and animal studies are needed before this can be attempted in man. Adenosine deaminase deficiency appears to be the disease in which this will be first attempted using a retroviral vector to insert the gene into the genome of pluripotential bone marrow cells.     

婴幼儿法乐四联症手术治疗近期疗效的影响因素

目的 探讨影响婴幼儿法乐四联症手术治疗近期疗效的各相关因素.方法 将2003年8月至2011年2月经作者一期手术纠治的117例年龄≤3岁的法乐四联症患儿分为疗效良好、疗效较差两组.分析手术时患儿年龄、体重、术前HCT值、McGoon指数、EDVI、主动脉阻断时间、转流时间、室间隔缺损大小、升主动脉与肺动脉干直径比、...     

主动脉缩窄的治疗研究进展

主动脉缩窄(coarctation of aorta,CoA)是主动脉的局限性狭窄,狭窄最常见于峡部,是一种常见的先天性心血管畸形,占所有先天性心脏病的5％ ～8％.缩窄导致上肢血压升高,下肢血压降低,并可引起心功能下降,未经治疗的CoA预后不佳.治疗方式包括外科治疗及经皮介入治疗,不同治疗方式的并发症发生率不同,术后长期监测其并发症、心功能是评估预后的重要指标.该文对主动脉缩窄的治疗方式及术后并发症、心功能情况的研究进展作一综述.     

早产儿脑病研究进展

早产儿脑病是复杂的原发性脑损伤和继发性脑发育异常疾病.过去几年对该病有了较为深刻的认识,该文就最新的有关早产儿脑病概念演变,脑损伤后的细胞分子机制和损伤后发育障碍,尤其是活化小胶质细胞介导的少突胶质细胞损伤机制、神经/髓鞘受损和丘脑、板层下神经元及大脑皮层的受损机制或发育成熟障碍进行综述,以便对该病有更深刻的认识.     

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??Inhaled corticosteroids??ICS?? are the most effective medicine for chronic airway inflammation nowdays. Atomization inhalation has been widely applied in clinics because of its efficacy??fewer side-effects and convenience. Here??we focused on some points which should be paid attention to??including how to choose appropriate patients??how to ensure the effectiveness of inhaled steroids and how to reduce possible side-effects.     

Treatment of retinopathy of prematurity

Retinopathy of prematurity is a potentially blinding disorder of premature infants. Retinal ablation of the avascular retina originally described using cryotherapy but now most commonly undertaken with laser photocoagulation, reduces the unfavourable structural outcomes and improves the functional visual acuity outcome. The CRYO-ROP study showed the long-term benefit of treatment of threshold disease compared with no treatment, however even with cryoablation 44.4% of treated eyes had a visual acuity of 6/60 or worse at 10 year follow-up. The ETROP study of earlier treatment for high-risk pre-threshold disease, rather than treatment at threshold, has shown that pre-threshold treatment of type 1 disease produces a significantly improved outcome. Despite treatment some infants develop retinal detachment for which various surgical treatments have been described, although not always with a good functional outcome. Future treatment modalities may include the use of anti-VEGF therapies.     

Epidemiology of respiratory distress of newborns

The present prospective study was conducted to find out the incidence, etiology and outcome of respiratory distress (RD) in newborns. All newborns (n=4505), delivered at this hospital over a period of 13 months, were observed for respiratory problems. Relevant antenatal, intranatal and neonatal information was noted. Cases were investigated for the cause of respiratory distress and followed up for the outcome. The overall incidence of RD was 6.7% Preterm babies had the highest incidence (30.0%) followed by post-term (20.9%) and term babies (4.2%). Transient tachypnea of newborn (TTN) was found to be the commonest (42.7%) cause of RD followed by infection (17.0%), meconium aspiration syndrome (10.7%), hyaline membrane disease (9.3%) and birth asphyxia (3.3%). TTN was found to be common among both term and preterm babies. While Hyaline membrane disease (HMD) was seen mostly among preterms, and Meconium aspiration syndrome (MAS) among term and post-term babies. Overall case fatality ration for RD was found to be 19%, being highest for HMD (57.1%), followed by MAS (21.8%) and infection (15.6%). Our results indicate that RD is a common neonatal problem. TTN accounts for a large proportion of thhese cases. MAS and infection also contribute significantly and are largely preventable. Without adequate ventilatory support HMD and MAS carry high mortality.