鬼臼毒素抗胃癌细胞株SGC 7901作用的实验研究

目的:研究鬼臼毒素抗胃癌SGC 7901细胞株的作用,为鬼臼毒素用于临床治疗胃癌提供依据.方法:不同浓度的鬼臼毒素(0,5,10,20和50mg/L)处理SGC 7901细胞后,采用MTT比色法和平板克隆形成实验检测细胞的增殖;采用流式细胞术检测细胞周期分布和细胞凋亡;裸鼠成瘤实验检测鬼臼毒素对SGC 7901细胞体内致瘤能力的影响.结果:鬼臼毒素呈时间与剂量依赖性抑制SGC 7901细胞生长,明显降低SGC 7901细胞平板克隆,显著诱导SGC 7901细胞凋亡,并使SGC 7901细胞阻滞于G2/M期,还能显著降低SGC 7901细胞裸鼠移植瘤的体积及质量.结论:鬼臼毒素能抑制胃癌SGC 7901细胞的生长,诱导SGC 7901细胞凋亡,并能抑制GC7901细胞的体内致瘤能力,此为鬼臼毒素临床治疗胃癌提供了科学依据.     

纳络酮在重症颅脑损伤治疗中的疗效观察

目的：为了探讨早期应用纳络酮（NLX）在急性重症颅脑损伤治疗中的作用。方法：我们在两年内对收治的急性重症颅脑损伤患者随机分为治疗组（64例）和对照组（70例），对两组病人的死亡率、伤残率和痊愈率进行统计学处理分析。结果：发现NLX治疗组病人的死亡率、伤残率明显低于对照组，P〈0.05，痊愈率明显高于对照组，P〈0.05。结论：早期应用纳络酮可有效降低急性重症颅脑损伤患者的伤残率和死亡率。     

珠海市禽类养殖户禽流感KAP现状调查与影响因素分析

目的了解珠海农村禽类饲养人员预防人感染高致病性禽流感知识、态度和行为的现状及可能行为影响因素,为健康教育干预提供依据。方法分层随机整群抽样选择养殖户,养殖户内主要负责养殖工作的人员作为调查对象,由调查员一对一询问调查对象完成调查问卷。结果珠海市农村禽类养殖户99%饲养的家禽是鸡。54.5%的调查对象知道鸭子也能传播禽流感,29%调查对象不知道人是怎么感染禽流感的,只有2%的人知道禽流感容易侵袭的各类人群;55.5%的人认为禽流感对自己有威胁,42%的调查对象表示如果发现异常死亡的禽鸟不会报告;禽类饲养数量多的养殖户对于自家禽类死亡后掩埋的比率和认为新买家禽与原有家禽分开饲养的比率显著高于饲养数量少的养殖户(p<0.05),家庭年经济收入高的养殖户对于禽鸟异常死亡的报告率明显高于收入低的养殖户;宰杀家禽时96.5%的调查对象都是徒手处理,没有任何防护。结论珠海农村禽类饲养人员预防人感染高致病性禽流感的知识较为薄弱,很多养殖户还存在家禽散养的习惯,群众对死禽报告率底,自我防护意识淡薄。     

Shh信号通路成员Shh蛋白在胃癌细胞SGC-7901中的表达

目的：研究Shh信号通路成员Shh蛋白在胃癌细胞中的表达，探讨其与胃癌发生的关系。方法：培养胃癌细胞（SGC-7901）和正常肠上皮细胞（IEC-6），用免疫细胞化学法检测两种细胞中Shh蛋白的表达，用RT—PCR法检测Shh mRNA在两种细胞中的表达。结果：Shh蛋白在正常肠上皮细胞中表达阳性率为15％，在胃癌细胞中表达阳性率为70％，Shh蛋白在正常肠上皮细胞中的表达明显低于胃癌细胞（P〈0．05）。Shh mRNA在正常肠上皮细胞中不表达或低表达，在胃癌细胞中明显表达（P〈0.05）。结论：Shh信号通路可能与胃癌发生有关。     

飞行时间质谱技术在HIV诊断应用性研究

[目的]用基质辅助激光解析电离飞行时间质谱（MALDI TOF MS）技术分析HIV感染者和健康人血清标本的多肽指纹图谱，建立HIV血清多肽指纹图谱诊断模型并探究其临床价值。[方法]选取的血清样本经Zip Tip C18层析预分离，运用MALDI TOF MS分析检测，获得HIV感染者和健康人血清标本的多肽指纹图谱，用SPSS13．0软件对数据进行分析，建立诊断模型。[结果]在分子量为800—4000Da范围内，共发现500个多肽峰，其中11个多肽峰在HIV感染组、正常对照组中表达均有显著差异（P〈0．05），5个在HIV感染组中表达上调（m／z1418．67，1465．67，1777．82，1864．82和2080．23），6个在HIV感染组中表达下调（m／z904．71，920．73，1076．73，1521．79，1552．75和2080．78）；（m／z2080．78＋2080．23＋1777．82＋1465．67）组合的P〈0．05，回归系数、相对危险度都比较理想，其ROC曲线下面积是1．0，以此建立了HIV血清多肽指纹图谱诊断模型。[结论]本研究建立的诊断模型可以有效区分HIV感染者和健康人，为HIV的诊断与筛查提供了一条崭新途径。     

氟哌酸锌的制备及其体外抑菌实验

 为研究氟哌酸锌的制备，采用４种方法：氢氧化钠法、氨水法、碳酸氢钠法、碳酸钠法制备氟哌酸锌。实验表明碳酸钠法、碳酸氢钠法、氨水法均较氢氧化钠法为好。体外抑菌实验表明，氟哌酸锌对金葡球菌、大肠杆菌、绿脓杆菌的抑制作用明显高于磺胺嘧啶锌。     

Fiberoptic ductoscopy for patients with nipple discharge

BACKGROUND: Breast carcinoma and precancer are thought to start in the lining of the milk duct or lobule, yet until recently, we have not had direct access to this area other than by blindly removing tissue by core biopsy or fine-needle aspiration. Fiberoptic ductoscopy (FDS) is an emerging technique allowing direct visual access to the ductal system of the breast through nipple orifice exploration. METHODS: We applied ductoscopy to 259 women who had nipple discharge, and we analyzed the visual findings, the cytological washings, and the subsequent histopathology. RESULTS: In 92 (36%) of these women, fiberoptic ductoscopy was successful in detecting an intraductal papillary lesion. Of these observed lesions, 68 (74%) were single papilloma, 21 (23%) were multiple discrete papillomas, and 3 (3%) were diffuse intraductal thickening which corresponded to diffuse papillomatosis on histopathological analysis. The overall positive predictive value of FDS screening was 83%. Of the lesions observed, 29.8% were located in the main (segmental) duct, 43.9% lesions in the first branch, 17.5% lesions in the second branch, 7.9% in the third branch, and 0.9% in the fourth branch. These lesions had an overall average distance of 2.7 cm from the nipple orifice. Ductal washings performed at the time of ductoscopy were effective at obtaining representative exfoliated ductal cells which could be evaluated for the presence of clumps (> 50 cells), clumps with atypia or single ductal cells. The presence of clumps with positive FDS increased the positive predictive value to 86%. CONCLUSIONS: Fiberoptic ductoscopy currently offers a safe alternative to ductography in guiding subsequent breast surgery in the treatment of nipple discharge.     

Celecoxib prevents tumor growth in vivo without toxicity to normal gut: lack of correlation between in vitro and in vivo models

Nonsteroidal anti-inflammatory drugs have potential for use in the prevention and/or treatment of colorectal cancer. We have studied the cytotoxic effect of a specific COX-2 inhibitor, celecoxib, against LLC, HCA-7, and HCT-15 cells grown in cell culture and have compared these results with its effect on HCA-7 cells grown as xenografts in nude mice. "High-dose" celecoxib (>20 microM) reduced the viability of all three cell lines in vitro as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometric analysis demonstrated that this loss of viability was attributable to the induction of apoptosis. Significantly, concentrations of the drug <10 microM had no effect on cell viability in vitro. The cytotoxic effects of high-dose celecoxib were independent of COX-2 inhibition because similar effects were observed in cox-2 (+/+), cox-2 (+/-) and cox-2 (-/-) fibroblasts. A plasma concentration of 2.3+/-0.7 microM was achieved when celecoxib (1250 mg/kg of chow) was fed to animals ad libitum. Despite a lack of toxicity at 2-3 microM celecoxib in vitro, there was attenuation of HCA-7 xenograft growth in vivo. Celecoxib had no effect on apoptosis, cell division, or the epithelial architecture of the normal gut in treated mice. These results support the need for additional clinical evaluation of celecoxib for treatment and/or prevention of colorectal cancer in humans.     

Human cord blood conditioned medium enhances leukemia colony formation in vitro

Childhood T-cell acute lymphoblastic leukemia (T-ALL) is one of the most common childhood cancers. Recently, we observed that pre-conditioning sub-lethally irradiated immunodeficient mice with human cord blood mononuclear cells facilitates in these mice high level engraftment of primary T-ALL cells obtained from patients. Here we report that human cord blood cells secrete a factor(s) which markedly enhances in vitro both colony number and burst size of the T-ALL clonogenic progenitors from patients. The enhancing activity does not correspond to IL-2, IL-15, nor to several other cytokines implicated in T cell proliferation/activation. Thus, it is possible cord blood may secrete an as yet unidentified factor(s) acting on leukemia clonogenic progenitors of T-ALL. Collectively, these studies should prove invaluable in addressing the growth properties of primary T-ALL cells from patients.     

Identification of the subcellular localization of daunorubicin in multidrug-resistant K562 cell line

We examined the subcellular distribution of daunorubicin (DNR) in resistant K562 cell line which overexpress the P-glycoprotein by confocal laser scanning microscopy. Three fluorescent probes - Rhodamine123, neutral red, NBD-ceramide, which stain the mitochondria, lysosomes, Golgi apparatus respectively, were used to identify the nature of the subcellular compartment sequestering daunorubicin. In sensitive k562 cell line, nuclear and cytoplasmic DNR fluorescence was intense and diffuse. In contrast, resistant K562 cell line showed a different DNR distribution. A bright fluorescence signal was located in the perinuclear region and peripheral plasma, the nucleus and other cytoplasmic region appear as empty, as suggested by the distribution of fluorescent probe Rhodamine123 specifically for mitochondria. Verapamil, an effective resistance modulator in P-glycoprotein MDR cells, restored the DNR distribution closer to that in the parent cells. Golgic inhibitor brefeldin A and lysosomotropic agent chloroquine had little effect on drug sequestration. Our studies demonstrate that daunorubicin may be sequestered in mitochondrial compartment in the resistant cells and P-glycoprotein plays an important role on mediating DNR transport.