Salicylate enhances necrosis and apoptosis mediated by the mitochondrial permeability transition.

Onset of the mitochondrial permeability transition (MPT) causes both necrotic and apoptotic cell death in cultured hepatocytes. Salicylate lowers the threshold for onset of the MPT. In this study, our aim was to determine whether nontoxic concentrations of salicylate potentiate MPT-mediated cell killing. In necrotic killing models to rat hepatocytes, salicylate (1 mM) enhanced calcium ionophore (Br-A23187)- and tert-butylhydroperoxide (t-BuOOH)-induced cell death, which was blocked or delayed by cyclosporin A (CsA, 2 microM), a specific inhibitor of the MPT. In hepatocyte apoptosis induced by tumor necrosis factor-alpha (TNF-alpha), salicylate accelerated cell killing after low-dose TNF-alpha (1 ng/ml), which by itself induced little apoptosis. Salicylate enhancement of apoptosis was associated with onset of the MPT and accelerated caspase 3 activation. Salicylate also augmented killing of MCF-7 human breast tumor cells by etoposide and PLC/PRF/5 human hepatoma cells by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). In conclusion, salicylate potentiates both necrotic and apoptotic cell killing by promoting onset of the MPT. Enhancement by salicylate of MPT-dependent apoptosis may play a role in protection by aspirin and other nonsteroidal anti-inflammatory drugs against colon, lung, and breast cancer.     

大肠杆菌胞嘧啶脱氨酶基因的克隆及其真核表达载体的构建

目的 克隆大肠杆菌胞嘧啶脱氨酶(CD)基因，构建真核表达载体，本研究拟探索该基因在肿瘤基因治疗中的应用基础。方法 根据GenBank数据库提供的CD基因核苷酸序列，设计并合成一对引物，采用PCR方法，从大肠杆菌基因组DNA中扩增出CD基因，并与pcDNA3．1定向连接，构建受控于人巨细胞病毒启动子的重组真核载体pcDNA3．1-CD，并用限制性内切酶、PCR和DNA测序进行鉴定。结果克隆了大肠杆菌CD基因，并构建了真核表达载体，经限制性内切酶酶切、PCR扩增和DNA测序证实了其正确性。结论 pcDNA3．1-CD真核表达载体构建成功。     

大鼠脑损伤时神经细胞c-fos 、c-jun和c-myc基因表达变化

目的观察大鼠脑损伤后不同时间皮质神经细胞早期快反应基因c-fos 、c-jun和c-myc表达变化.方法应用Northern杂交、原位杂交和免疫组织化学方法检测皮质神经细胞中c-fos、c-jun和c-myc的表达.结果脑损伤后15 min,伤侧皮质神经细胞出现上述3种基因mRNA的表达,随时间的延长,表达逐渐增加,于伤后3 h达高峰并持续至伤后24 h,伤后72 h恢复至对照水平.c-fos和c-jun蛋白表达亦于伤后15 min出现,c-myc蛋白表达于伤后30 min出现,并均于伤后3 h达高峰,持续至伤后6 h,伤后24 h表达消失.结论脑损伤后上述3种基因表达特点与其它脑损害不同,可能与损伤机制和继发性神经细胞损害有关.     

人类颞骨火棉胶切片中线粒体DNA的扩增及重组测序

目的应用分子生物学技术建立人类颞骨火棉胶切片中的ＤＮＡ分析方法。方法采用多聚酶链反应（ｐｏｌｙｍｅｒａｓｅｃｈａｉｎｒｅａｃｔｉｏｎ，ＰＣＲ）配合不同的引物、扩增方式及酶切技术检测长期保存的７例（９侧）颞骨火棉胶切片中微量线粒体ＤＮＡ的片段缺失及点突变，ｐＧＥＭＴ载体进行扩增片段的重组与克隆。结果９侧颞骨ＤＮＡ提取液中均可见正常的１３５ｂｐ扩增片段，巢式ＰＣＲ检出其中２例生前患老年聋者（各查１侧）有线粒体ＤＮＡ大片段缺失，测序结果证实扩增的准确性。结论分子生物学技术在颞骨切片研究中的应用对于提高其回顾性研究水平有重要意义，目前可在耳科疾病的研究中发现相关的基因突变或病原体。     

Sequence Analysis of Genes Encoding Rodent Homologues of the Human Tumor-rejection Antigen SART-1

Human SART-1 ( hSART-1 ) gene encodes a 125 kD protein with a leucine-zipper motif expressed in the nucleus of all proliferating cells, and a 43 kD protein expressed in the cytosol of most epithelial cancers. In this study, two rodent genes ( rSART-1 and mSART-1 ) homologous to hSART-1 were cloned from cDNA libraries of murine brain and a rat tumor cell line, respectively. mSART-1 and rSART-1 were highly homologous to hSART-1 with 86% and 84% identity at the nucleotide level, and 95% and 91% at the protein level, respectively. The leucine zipper domain and two basic amino acid portions that bind DNA, as well as peptide sequences recognized by human cyto-toxic T lymphocytes (CTLs), were all conserved in these rodent genes. Nuclear protein homologous to the 125 kD hSART-1₈₀₀ protein, but not to the 43 kD cytosol SART-1₂₅₉ protein, was detectable with specific antibody in the nuclear fractions of rodent tumor cell lines, and normal rodent fetal liver and testis. These rodent genes should be a novel tool for studies on the biological roles of the SART-1 gene, and also in the construction of animal models of specific immuno-therapy using SART-1 gene products.     

LOSS OF HETEROZYGOSITY ON CHROMOSOME 13 IN SQUAMOUS CELL CARCINOMAS OF THE LARYNX

ＬＯＳＳＯＦＨＥＴＥＲＯＺＹＧＯＳＩＴＹＯＮＣＨＲＯＭＯＳＯＭＥ１３ＩＮＳＱＵＡＭＯＵＳＣＥＬＬＣＡＲＣＩＮＯＭＡＳＯＦＴＨＥＬＡＲＹＮＸＢａｉＳｕｊｕａｎ白素娟ＺｈａｎｇＸｕｅ张学ＷａｎｇＪｕｎ王筠ＳｕｎＫａｉｌａｉ孙开来ＦｅｉＳｈｅｎｇｚｈｏｎ...     

Evolutionary Classification of Homeodomains

Purpose and Methods: We performed multiple comparisons between available amino acid (aa) sequences of homeodomain(HOM)-containing proteins from a wide spectrum of animals to create an evolutionary classification of the proteins. Results: Based on results of statistical and special computational analyses of over 500 homeodomain aa sequences (HOMs) a novel system of concepts describing complex structural correlations between homologous proteins is proposed. This system includes such notions as differentiated isofunctionality of aa, chemotype, stereotype, local functional motifs, gradual conservativeness of aa positions, and group-specific domain patterns, as well as major categories of the evolutionary classification of HOMs (Division, Type, Branch, Class, Family, Series, Variety, Sort). Using this approach, a complete structural systematics of HOMs belonging to proteomes of eukaryotic animals is proposed. Conclusions: The proposed structural classification of HOMs is in full agreement with the bulk of experimental data revealing complex functional similarities and differences among HOMs in terms of their expression patterns in developing embryos. It turn, this classification can provide answers regarding homology among homeodomains when experimental data are conflicting.     

鼻咽癌肿瘤细胞增殖与凋亡关系

目的 了解鼻咽癌肿瘤细胞增殖与产凋亡的关系及ｂｃｌ－２表达在此过程中的作用。方法 ６５例鼻咽癌活检组织及１５例癌旁组织用免疫组化技术检测ｂｃｌ－２和ＰＣＮＡ;ＨＥ染色中作核分裂计数,并将后两者合并为增殖指数;用原位末端标记法（ＩＳＥＬ法）显示４４例鼻咽及１５例癌旁组织中的细胞凋亡。结果 ①鼻咽癌ＰＣＮＡ、核分裂像数、凋亡细胞数均高于癌旁上皮组织,但与组织分型无关;增殖指数与凋亡细胞数呈正相关。②ｂ     

正天丸对小白鼠心脏等基因的影响及治疗各种头痛可能的机理

目的观察方剂“正天丸”，调节正常小白鼠心、甲状腺、肾和胰腺等基因活力的增减与其功能相联系，对比多瘀、多风、多湿“证”头痛患者，有助于了解正天丸能治疗各种头痛患者的奥秘。方法用3H-dTR掺人已连续服正天丸药水五天的正常小白鼠各器官组织DNA(基因)，并测其放射性。结果促进小白鼠心、甲状腺、淋巴结、肾、胸腺、肾上腺和肺基因活力分别提高176．0％、149．8％、108．2％、81.3％、58．0％、36．9％、21．7％，并使胰腺、骨髓、小肠和脾基因分别受到62.3％、43．7％、38．4％、31．3％的抑制。结论正天丸方剂的有效成分，如阿魏酸、川芎嗪、芍药甙、β谷甾醇、红花甙、苦杏仁甙、钩藤碱、伪麻黄碱等调节特定基因-心肌(“心激素”、心NOS等)基因、甲状腺基因、肾基因和胰腺基因等及其调理其它所有基因的结果，使心脑血管内的血液成分、血管舒缩物质、神经体液、ROS、电解质等逐渐恢复平衡。所谓“正天”，即正天丸多成分、多靶点、多途径、多层次、多环节调理与清除由风湿瘀所引起的，中枢神经系统可感受疼痛的神经星形胶质细胞兴奋因子(致炎因子、NO与其它因子等)，使各种头痛患者疼痛感缓解或消失。     

葡多酚对胸腺细胞凋亡和线粒体膜电位的影响

目的　观察葡多酚 (GPC)对氧化损伤引发的胸腺细胞凋亡和线粒体膜电位的影响。方法　在体外培养的胸腺细胞中加入不同浓度的GPC和培养液中浓度为 12 5 μmol L的H2 O2 ,共同培养 2h ,采用流式细胞术检测细胞凋亡和线粒体膜电位水平。结果　氧化损伤组细胞凋亡率为 (2 9 5 3± 3 8) % ,线粒体膜电位为 2 7 2 4± 2 2 (D值 ) ,5 0mg LGPC保护组则分别为 (8 6 1± 1 2 ) %和 87 5 5± 4 7(D值 ) ,两组间的差异均有显著性 (P <0 0 5 )。结论　GPC可有效抑制氧自由基引发的胸腺细胞凋亡和线粒体膜电位的下降 ,对胸腺细胞的氧化损伤有良好防护作用