自然贮存苹果的生化分析及形态解剖学研究

本文对自然贮存六个月的秦冠、红富士及新红星苹果果实在生化成分及显微、超微结构上进行了对比研究,发现红富士果实中果胶质、总糖及粗蛋白含量均高于其它品种;三种果实表面均有不同形态的蜡质分布;果皮角化层以红富士较厚,新红星次之;不同品种果肉细胞的形态有明显差异。本文对此结果进行了初步的探讨,以期为苹果贮存研究积累资料。     

Study of cell killing and morphology on S180 by ultrasound activating hematoporphyrin derivatives

The inhibition of ascitic S180 and induced sarcoma 180 in vivo was studied with the combination of hematoporphyrin derivatives (HpD) and ultrasound (US) at the frequency of 1.1 MHz and different intensities by light microscopy observation, electronic microscopy observation, cytochemical analysis and fluorescence labeling. The present study indicated that the injury of ascitic S180 increased as time passed and the inhibitory effect was stronger in US plus HpD group than that in other groups. Our results also indicated that the changes in cell structure, cytochrome C oxidase activity, the degradation and missing of DNA were the important factors that inhibited the tumor cell growth and even induced celldeath. The phenomenon of apoptosis of tumor cells indicated that cell death andinduced apoptosis exist in the treatment of sonodynamic therapy (SDT). Our study investigated the mechanism underlying the killing effect of S180 induced by USactivating HpD by the observation of cell morphology and dynamic changes from seminal injury to succeeded injury even to death. It would provide rich referencefor the study of SDT.     

血卟啉在H-22肝癌荷瘤小鼠体内的分布

目的探讨声敏剂血卟啉衍生物在肿瘤组织中的富集情况,以便在给药后超声结合血卟啉治疗肿瘤时选择最佳的超声处理时间。方法H-22肝癌荷瘤小鼠尾静脉注射HpD后,不同时间点取材,采用荧光分光光度法测定不同组织提取液中HpD的荧光强度,研究HpD在不同组织中的分布以及代谢变化。结果给药后2 h肿瘤组织以外的其他各组织内(血浆、肝、肾、皮肤、肌肉)血卟啉含量均达到其代谢过程的最高点,后逐渐下降;肿瘤组织中的HpD含量注射后不断上升,6 h时达到顶峰,随后又开始下降,10~24 h代谢比较缓慢,表现为肿瘤组织中对HpD的滞留作用,24 h时肿瘤组织中的HpD含量高于其他各组织,48~72 h趋于稳定在较低水平。结论提出了不同部位的肿瘤应选择各自适当的时间点进行超声处理。     

鉴定痢疾杆菌毒力基因的SW480细胞模型构建

信号标签诱变技术（STM）是一种在体内高通量筛选病原体毒力基因的新方法,在应用时的一个先决条件是要建立合适的体内筛选系统。为将该技术应用于福氏痢疾杆菌,我们使用三个福氏痢疾杆菌菌株进行了预试验：通过同源重组构建而成的带有氯霉素抗性且aroA和virG基因失活的突变株RC426;因在侵袭质粒上自发缺失3个基因座(ipaBCDA, invA 和 virG)的另一减毒突变株T32,其曾被用作福氏痢疾杆菌的口服疫苗;还有具侵袭宿主细胞能力的野生性菌株2457T。将RC426、T32和2457T混合后侵袭结肠细胞系SW480,不同时间回收经侵袭后细胞裂解液中的菌体并统计。结果显示在侵袭12h内回收到减毒突变株的量与野生有毒株存在显著性差异,表明SW480 细胞系可用于痢疾杆菌的STM研究。Abstract: Signature-tagged mutagenesis (STM) is a novel technology with high throughput screening ability to identify virulent genes of pathogen in vivo. An appropriate animal or cell line model is one of prerequisites by exploiting this technique. In order to apply STM to Shigella flexneri, RC426 was constructed as an attenuated mutant with chloramphenicol resistance and aroA and virG genes inactivated by homologous recombination; Another attenuated strain T32 was used as an oral S. flexneri 2a vaccine due to a spontaneous deletion in three loci (ipaBCDA, invA and virG) on the virulence plasmid. The wild type strain 2457T had the invasion ability into host cells. The three strains, RC426, T32 and 2457T, were mixed together to invade colon cancer cell line SW480, and the distinct strains were recovered and counted from cell lysates of invaded SW480 in different time. The results showed that there were statistically significant differences between the amounts of two attenuated strains recovered and that of virulent strain within 12h invasion, indicating SW480 was a suitable cell model for applying STM to screen virulent genes of Shigella flexneri.     

太白红杉（Larix chinensis）叶的形态解剖学特征与环境因子的关系

根据生态气候学方法推断出不同海拔高度气候指标,应用多元统计方法,对分布于秦岭太白山地区海拔3000－3400m的太白红杉（Larix chinensis)叶特征进行了生态解剖学研究,分析了影响其变化的主导生态因子。观察指标包括叶形态指标（叶片总厚度、每束叶中的叶数和叶长宽比）、叶解剖学特征（叶表皮角质膜厚度、上、下表皮厚度,近上、下表皮叶肉厚度,内皮层厚度,管胞直径,叶传输组织和维管束厚度及其与叶片总厚度之比）。结果表明：（1）水热综合因子是影响太白叶长宽比和叶表皮角质膜厚度的主导因子,随着水热综合因子的增大,叶长宽比呈增加趋势,而角质膜厚度则逐渐变薄。（2）年降水量是影响其它形态解剖学指标的主导因子,随着年降水量的增加,每束叶中的叶数、叶厚度、管胞直径、叶传输组织和维管束厚度、内皮层厚度、传输组织和维管束厚度及其与叶总厚度之比呈减少和变薄的趋势,而上、下表皮厚度则逐渐增加。（3）近上、下表皮叶肉厚度与环境因子无明显相关,可能属于比较保守的性状。     

声化学诱导艾氏腹水瘤细胞凋亡机制初探

本研究采用频率1.43MHz,声强3W/cm2的高频聚焦超声处理艾氏腹水肿瘤细胞,研究超声激活血卟啉诱导艾氏腹水肿瘤细胞凋亡的途径及其与癌细胞内的氧自由基之间的关系。通过细胞免疫组织化学方法检测与癌细胞凋亡相关的Bax,细胞色素c和caspase-3蛋白的动态表达,黄嘌呤氧化酶法检测超氧化物歧化酶活性变化,硫代巴比妥酸法检测膜脂质过氧化物的含量。结果发现超声加血卟啉处理1h,癌细胞胞浆中的三种促凋亡蛋白表达增多,3h时表现为高表达;处理1h的癌细胞,超氧化物歧化酶活性下降,膜脂质过氧化物增多。研究结果表明超声激活血卟啉诱导艾氏腹水肿瘤细胞凋亡可能通过线粒体途径,且与癌细胞受损后产生的氧自由基有关。     

Study of cell killing and morphology on S180 by ultrasound activating hematoporphyrin derivatives

Sonodynamic therapy (SDT) is one of antitumor strategies that kill tumor cells through the synergistic effects caused by the combined use of HpD and US[1]. SDT is based on the following principle. Ultrasound used in SDT can penetrate the deep tissue and activate HpD, which accu- mulated in tumor cell, and produce highly active oxygen species[2] such as singlet oxygen (1O2), which can destroy the structure of tumor cells. So far the studies on the SDT have focused mainly on the mechan…     

槐树器官、胚胎发生及细胞学观察

槐树(Sophora japonica)是多年生木本豆科植物,常作行道树,并为优良的蜜源及药用植物。陈维伦等曾以胚轴和子叶进行槐树的组织培养,获得了无根苗,我们曾简要的报道了其子叶、胚轴和幼叶的培养及植株再生。本文着重报道槐树子叶培养中器官、胚胎发生及细胞学观察结果。8月上旬采取15年龄槐树的肉质果荚,70%酒精浸泡30秒,0.2%HgCl_2常规灭菌10分钟,无菌水冲洗3次,在无菌条件下剥去果荚及种皮,切下子叶,并一分为二,接种在 MS     

细胞骨架纤维间的相互联系

细胞骨架是由微丝、微管及中间纤维组成的蛋白质纤维网络体系.三种骨架纤维具有不同的形态、结构和功能特征,它们在细胞中彼此联系、互相依赖,共同构成完整的细胞骨架系统,在细胞的各项生命活动中起着重要的作用.认识与研究细胞骨架的这三种纤维之间存在的相互联系,揭示它们作用的分子机制,对全面、科学的认识细胞骨架系统在细胞中起所的作用以及对于科学研究都有着重要的意义.