根癌农杆菌对云南红豆杉原生质体的转化

本文介绍了根癌农杆菌T-DNA对云南红豆杉原生质体的转化,分析了转化系的紫杉醇合成能力。实验以生长20 d的云南红豆杉幼茎诱导的淡黄色愈伤组织为材料,经酶解可分离出大量有活力的原生质体。在由B5无机盐、KM有机成分、3.0 mg/L 2,4-D、0.1mg/L KT和0.45 mol/L果糖组成的培养基中培养1周后,原生质体再生细胞持续分裂形成细胞团。根癌农杆菌对原生质体的转化能力与原生质体生长状态及菌株相关。虽然刚分离的或已再生细胞壁的原生质体不能被根癌农杆菌转化,但由10个以上细胞组成的原生质体克隆和根癌农杆菌B6S3菌株共培养后可实现T-DNA转化,高压纸电泳检测转化系具有冠瘿碱的合成,转化率约为5％。HPLC证实转化系具有合成紫杉醇的能力,但不同转化系中紫杉醇含量变异很大,最高含量为0.076％,是对照愈伤组织的6倍,表明T-DNA的插入改变了培养细胞对紫杉醇的合成。获得的高产转化系细胞生长比对照低,但继代培养中其生长和紫杉醇积累基本保持稳定。尽管转化系合成紫杉醇能力远未达到商业化生产的要求,但研究通过T-DNA对原生质体的转化而实现插入诱变,可以为分离高产紫杉醇优良细胞系提供单细胞筛选系统。     

大枣多糖的分离、纯化及分子量的测定

大枣果肉用乙醇回流脱脂,80～100℃热水浸提,提取液经减压浓缩,乙醇分级沉淀,三氯乙酸脱蛋白,透析,透析内液再经减压浓缩、醇沉得到三个粗多糖ZJ-A’,ZJ-B’,ZJ-C’,ZJ-B’经DEAE-Cellulose柱、Sephacryl S-300柱反复纯化,得大枣多糖ZJ-1、ZJ-2,高效凝胶渗透色谱(HPGPC)和常压凝胶柱色谱分析表明,ZJ-1、ZJ-2为均一多糖,HPGPC法测定分子量(MW)分别为9848、8991,紫外吸收光谱表明,ZJ-1、ZJ-2无核酸和蛋白质的特征吸收峰。     

乳腺癌根治术后皮瓣坏死原因及预防措施探讨

目的 探讨乳腺癌术后皮瓣坏死的原因及预防皮瓣坏死的新方法。方法 将1990～1999年420乳腺癌病例分为对照组和实验组,将其手术方法进行对比研究。结果 前6年对照组皮瓣坏死率为43.3％,后4年实验组皮瓣坏死率为11.8％。经统计学处理,两组差异有显著性(P<0.01)。结论 实验组的新措施对预防乳腺皮瓣坏死有重要作用,真皮层血管网的损伤是皮瓣坏死的根本原因。     

电阻抗断层成像硬件系统的初步研究

各种原因导致的人体重要器官的缓慢出血等是导致病人死亡或预后较差的重要原因之一,目前的医学成像技术,包括CT、MRI、PET、超声等还无法对出血的过程进行长期、连续的床旁监测和监护。电阻抗断层成像是以目标体内电阻抗的分布或变化为成像对象的一种新型成像技术,作为一种廉价的无损伤检测技术,不使用核素或射线,无毒无害,因而可以成为对病人进行长期、连续图像监护的设备。本文介绍了一个基于物理模型的电阻抗成像硬件系统(FMMU V3),包括具有32个银复合电极的物理模型、采用DDS技术的恒流激励源、高精度信号检测模块、驱动测量模式程控设置模块、数据采集模块、数字I/O模块和高精度多路电源模块。该系统基于物理模型的测量数据经100次迭加后,测量精度在小信号时为1.0%,大信号时为0.1%。采用外触发DMA方式采集一组成像数据(32 X 31个)的时间小于1秒,基本满足了基于物理模型的动态成像要求,并给出了基于物理模型的初步动态成像结果。     

Mechanisms of proteasome inhibitor PS-341-induced G(2)-M-phase arrest and apoptosis in human non-small cell lung cancer cell lines.

PURPOSE: PS-341 is a novel dipeptide boronic acid proteasome inhibitor with in vitro and in vivo antitumor activity that induces mechanisms of apoptosis by unknown mechanisms. EXPERIMENTAL DESIGN: Human non-small cell lung cancer cell lines were used to investigate effects PS-341 on cell proliferation, cell cycle progression, and the induction of apoptosis. RESULTS: PS-341 was 38-360-fold more cytotoxic against H460 cells when compared with the proteasome inhibitors MG-132 and PSI. Differential PS-341 cytotoxic effects were found with respect to P53 function: H322 cells (p53 mutant) were 6-fold less sensitive as compared with H460 cells (p53 wild type); and H358 cells (p53 null) were 1.6-fold more sensitive as compared with H460 cells (p53 wild type). A concentration- and time-dependent cell cycle blockade at G(2)-M phase was seen for H460 cells without any direct effects on microtubule polymerization or depolymerization. PS-341 exposure in H460 cells led to stabilization of p53, induction of p21(cip/waf-1) and MDM2 expression, an increase in cyclin B and cyclin A, and the activation of cyclin B and cyclin A kinases. MDM2 induction was found only in H460 cells, whereas in H322 and H358 cells, G(2)-M-phase arrest, p21(cip/waf-1) induction, and an increase in cyclin B1 were found. The commitment of G(2)-M-phase cells to apoptosis was verified by the activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase in drug-free medium. CONCLUSIONS: Our data suggest that the PS-341-induced G(2)-M-phase arrest may be associated with the inhibition of degradation of cell cycle regulators and that the up-regulation of p21(cip/waf-1) expression may be via p53-dependent and/or -independent pathways. The resulting disturbance of cell cycle progression leads either to growth inhibition or to the initiation of apoptotic pathways.     

龙参颗粒的质量标准研究

目的:为龙参颗粒提供方便可行的质量控制方法。方法:采用薄层色谱法进行定性鉴别;用HPLC法对成品中苦参碱进行含量测定。结果:薄层层析可成功鉴别出当归和黄芪药材;Hypersil NH_2,色谱柱(4.6mm×200mm,5μm);柱温:25℃;流动相:乙腈-0.02mol/L磷酸二氢钠(82:18);流速:1mL/min;检测波长:215nm。加样回样率为97.70％,RSD为1.56％。结论:本实验方法基本可控制龙参颗粒的质量。     

Val158Met Polymorphism in catechol-O-methyltransferase gene associated with risk factors for breast cancer.

Extensive mammographic density is heritable, strongly associated with increased breast cancer risk, and is influenced by sex hormone exposure. In a cross-sectional study of 181 pre- and 171 postmenopausal women without breast cancer, we examined the relationship of a functional polymorphism in catechol-O-methyltransferase (COMT; VAL-->MET) to mammographic density and other risk factors for breast cancer. We hypothesized that individuals who inherited the low-activity form of COMT (COMT*2 allele) would have higher levels of breast density, presumably because of reduced inactivation/detoxification of catecholestrogens. Subjects were recruited across five categories of breast density. Risk factor information, anthropometric measures, and blood samples were obtained; sex hormone and growth factor levels were measured, and COMT genotypes determined. Mammograms were digitized and measured using a computer-assisted method. After adjustment for age and ethnicity, among pre- but not postmenopausal subjects, each low-activity COMT*2 allele was associated with lower levels of percentage breast density. The statistical significance of this association was lost after further adjustment for serum growth factors [growth hormone, insulin-like growth factor-1 (IGF-1), and insulin-like growth factor binding protein-3 (IGFBP-3)], hormones [follicle-stimulating hormone (FSH) and progesterone], and body size (body mass index and waist:hip ratio). The low-activity COMT*2 allele was also associated, after adjustment for age and ethnicity in premenopausal women, with lower serum levels of IGF-1, higher levels of FSH and progesterone, and with a larger waist:hip ratio, body mass index, and subscapular skinfold. After adjustment for body size, the associations of genotype with IGFBP-3 and FSH were no longer significant. These findings indicate that COMT genotype is associated with several risk factors for breast cancer and suggest that the low-activity COMT*2 allele is associated with a reduced risk of breast cancer among premenopausal women.     

加替沙星制剂中有关物质检查与含量测定的高效液相色谱法

目的　建立加替沙星制剂中加替沙星的含量及其有关物质测定的 RP- HPL C法。方法　采用Shimpack VP- ODS柱 (15 0 mm× 4 .6 mm,5 μm) ,流动相为 1%三乙胺 (磷酸调节 p H至 4 .5 ) -乙腈 (82∶ 18,体积比 ) ,检测波长 32 5 nm。结果　加替沙星在 2 .32～ 4 6 .4 8μg/ ml浓度范围内线性关系良好 ,日内及日间 RSD分别为 1.1%和 1.7%。平均回收率为 99.9% ,RSD为 0 .6 5 %。最低检测限为 0 .2 μg/ ml。结论　该方法简单 ,灵敏度高 ,结果准确 ,可用于加替沙星制剂的含量测定及有关物质检查。     

普胸手术预防性应用头孢呋辛随机对照研究

目的　评价预防性使用单剂头孢呋辛对普通胸外科手术后感染的预防效果。方法　通过随机对照试验 ,将 2 6 4例普胸手术患者随机分成单剂组 (n=134)和多剂组 (n=130 ) ,比较两组的术后感染率、平均住院时间和平均住院费用。结果　单剂组的术后感染率 (8.96 %)与多剂组的术后感染率 (7.6 9%)不具有显著性差异 (P>0 .0 5 ) ,两组的住院时间也无显著性差异 (P>0 .0 5 )。但是单剂组的平均住院费用比多剂组少1345 .90元 (P<0 .0 5 )。结论　单剂头孢呋辛是预防普胸手术后感染有效的抗生素方案。