2006年秋季东海陆架浮游植物群集

根据2006年11月19日—12月24日在东海陆架海域（24.0°—32.0°N,120.0°—127.0 °E）进行的综合采样调查,对调查海域浮游植物的群集特征进行了研究.本次调查共发现浮游植物4门64属145种（包括未定名种）,其中硅藻是该调查海区浮游植物的主要功能群,其次为甲藻.主要的优势种为菱形海线藻、圆海链藻、丹麦细柱藻、斯氏几内亚藻、尖刺伪菱形藻和铁氏束毛藻等.浮游植物细胞丰度为0.09～5.11 cells·ml^-1,平均值为4.92 cells·ml^-1,秋季东海陆架浮游植物细胞丰度的平面分布主要由浮游硅藻刻画,其高值出现在调查区的北、东部离岸海域,细胞丰度大于30 cells·ml^-1.浮游植物及硅藻和甲藻的细胞丰度垂直变化趋势基本上都是随着水深增加,丰度逐渐减小.各个断面细胞丰度密集区主要集中在表层,个别站位的中层和底层也出现浮游植物密集区.调查区浮游植物的多样性指数平均值为2.80,其高值位于调查区东北和东南部,物种均匀度指数平均值为0.81,其高值位于调查区中部,生物多样性的分布与细胞丰度的分布一致.从Pearson相关性指数来看,亚硝酸盐、溶解态有机氮(DON)和温度显著影响调查区浮游植物的生长.     

郧县人遗址石核的研究

在郧县人遗址中发现的石核占整个遗址石制品总数的26%。虽然数量仅77件,但从石核上可以看出打片以锤击法为主,采用硬锤直接打击。其利用率不高。石核的打片长度基本上只占该台面周长的一半以下,多在台面的一个边打片,剥片面上的石片疤多为单层,有些打下一块石片后就不再继续打片了。     

用抑制性差减杂交构建新疆Kaposi肉瘤差异表达基因文库

目的:分离卡波氏肉瘤(Kaposi′s sarcoma,KS)差异表达基因,并建立相应的cDNA文库,为从分子水平揭示KS发病机制打下良好的基础。方法:采集KS肉瘤及来源于同一患者的正常皮肤组织,抽提总RNA,经逆转录酶合成dscDNA,并经RsaⅠ酶切,与2种不同的接头衔接,分别以正常组织和肿瘤组织作为tester和driver,进行双向抑制性差减杂交(suppression subtractive hybridization,SSH),初步筛选KS肉瘤与正常皮肤差异表达基因,将差异基因PCR扩增,产物与pGEM-Teasy克隆载体连接,转化DH5α大肠杆菌,采用蓝白斑筛选,获得白色阳性克隆菌落,并煮沸破菌,PCR扩增出未知基因片段。结果:差减得到差异基因片段多位于200~500bp,成功构建了2个分别代表在KS肿瘤组织中表达上调和下调的基因文库。结论:经双向抑制性差减杂交获得了KS差异表达基因文库。抑制性差减杂交是一种快速、方便、有效的建立差异基因文库的方法。     

Elatoside C protects against hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes through the reduction of endoplasmic reticulum stress partially depending on STAT3 activation

Endoplasmic reticulum (ER) stress-induced apoptosis has been suggested to contribute to myocardial ischemia–reperfusion (I/R) injury. Elatoside C is one of the major triterpenoid compounds isolated from Aralia elata that is known to be cardioprotective. However, its effects on I/R injury to cardiac myocytes have not been clarified. This study aimed to investigate the possible protective effect of Elatoside C against hypoxia/reoxygenation (H/R)-induced H9c2 cardiomyocyte injury and its underlying mechanisms. H9c2 cardiomyocytes were subjected to H/R in the presence of Elatoside C. Our results showed that Elatoside C (25 μM) treatment provided significant protection against H/R-induced cell death, as evidenced by improved cell viability, maintained mitochondrial membrane potential, diminished mitochondrial ROS, and reduced apoptotic cardiomyocytes (P < 0.05). These changes were associated with the inhibition of ER stress-associated apoptosis markers (GRP78, CHOP, Caspase-12 and JNK), as well as the increased phosphorylation of STAT3 and an increased Bcl2/Bax ratio. Moreover, these effects of Elatoside C were prevented by the STAT3 inhibitor Stattic. Taken together, these results suggested that Elatoside C can alleviate H/R-induced cardiomyocyte apoptosis most likely by activating the STAT3 pathways and reducing ER stress-associated apoptosis.     

病毒巨噬细胞炎症蛋白-Ⅱ对载脂蛋白B mRNA编辑酶催化样蛋白3G和正常T细胞表达分泌的调节活化蛋白表达的影响

目的:明确病毒巨噬细胞炎症蛋白-II(viral macrophage inflammatory protein-II,vMIP-II)对HIV-1抑制因子:载脂蛋白BmRNA编辑酶催化蛋白3G(apolipoproteon B mRNA-editing catalytic polypeptide-3G,APOBEC 3G)和正常T细胞表达分泌的调节活化蛋白(regulated upon activation normal T expressed and secreted,RANTES)表达的影响。方法:构建vMIP-II真核表达载pEGFP-N3-vMIP-II,分别采用电穿孔和脂质体转染的方法将其转染至Jurkat和293T细胞。荧光定量PCR检测vMIP-II基因对Jurkat细胞和293T细胞内的抗艾滋病基因APOBEC3G和RANTES表达水平的影响。结果:测序结果显示成功构建了的vMIP-II真核表达载体,荧光显微镜观察估计转染效率达到50%左右。与空载体组相比较,转染pEGFP-N3-vMIP-II组的Jurkat细胞内的APOBEC3G和RANTES分别上调4.97倍和7.31倍,293T细胞内的APOBEC3G和RANTES分别上调为5.73倍和8.14倍。结论:vMIP-II基因不同程度的上调了Jurkat细胞和293T细胞内的抗艾滋病基因APOBEC3G和RANTES的表达。     

Expression of the antimicrobial peptide cecropin fused with human lysozyme in Escherichia coli

Lysozyme is an abundant, cationic antimicrobial protein that plays an important role in host defense. It targets the β (1–4) glycosidic bond between N-acetylglucosamine and N-acetylmuramic residues that make up peptidoglycan, making lysozyme highly active against Gram-positive bacteria. However, lysozyme alone is inactive against Gram-negative bacteria because it cannot reach the peptidoglycan layer. Cecropins are cationic molecules with a wide range of antimicrobial activities. The main target for these peptides is the cytoplasmic membrane. We resume that cecopin may disrupt the outer membrane, giving the enzyme access to the peptidoglycan in cell wall. So in the present study, novel hybrid protein combining Musca domestica cecropin (Mdc) with human lysozyme (Hly) was designed. The DNA sequence encoding recombination fusion protein Mdc–hly was cloned into the pET-32a vector for protein expression in Escherichia coli strain BL21 (DE3). The protein was expressed as a His-tagged fusion protein, and the Mdc–hly was released from the fusion by enterokinase cleavage and separated from the carrier thioredoxin. Antimicrobial activity assays showed that the recombinant fusion protein Mdc–hly has improved in vitro antimicrobial activity and action spectrum compared to Mdc and hly. Mdc–hly may have important potential application as a future safely administered human drug and food additive.     

猴泡沫病毒（SFV）RT-nestedPCR检测方法的建立及初步应用

目的建立实验猴群及相关生物制品猴泡沫病毒（SFV）的PCR检测方法。方法选择SFV-1、SFV-3、SFVCPZ前病毒序列的pol基因同源性较高的区域设计嵌套引物对SFV-1毒种进行RT-nestedPCR扩增并克隆测序,以确定其准确性,通过验证方法的特异性和敏感性,初步应用该方法对恒河猴外周血淋巴细胞（PBLs）,常用猴肾传代细胞及猴源性生物制品进行检测。结果经RT-nestedPCR扩增出的片断与SFV-1 cDNA序列同源性达到99%,对10只恒河猴的检测结果为5只阳性,5只阴性,对常用猴肾传代细胞及脊髓灰质炎疫苗的检测结果均为阴性。结论所建立的SFV RT-nestedPCR检测方法能准确的检测出恒河猴SFV的感染情况,对控制实验猴群的质量具有重要意义。该方法可用于检测猴源性生物制品中SFV的污染情况,为保证生物制品应用的安全性提供一定依据。     

SCD1在高脂饮食大鼠肝脏的表达及其与肝细胞凋亡的相关性

目的:探讨高脂饮食大鼠肝脏中硬脂酰辅酶A去饱和酶1(stearoyl-CoA desaturase 1,SCD1)的表达及其与肝细胞凋亡的相关性.方法:30只SD大鼠随机分成正常组和高脂组,分别给予普通饲料和高脂饲料喂养.在实验的第8w,16w和24w分批处死,观察肝细胞组织学改变,RT-PCR方法检测SCD1和丝氨酸棕榈酰转移酶(serine palmitoyl transferase,SPT)mRNA的表达,TUNEL方法观察肝细胞的凋亡.结果:肝组织HE染色显示高脂组大鼠肝脏内肝细胞呈弥漫性脂肪变性,8w即达到脂肪肝的诊断标准.RT-PCR分析结果显示高脂组SCD1 mRNA表达下降,SPTmRNA表达进行性上升.TUNEL凋亡检测表明,随着高脂饮食时间延长,肝细胞凋亡趋于严重.SCD1表达与SPT和凋亡指数(AI)之间呈负相关,SPT表达和AI指数之间呈正相关.结论:长期高脂饮食可引起肝SCD1表达下调,同时促进细胞凋亡关键基因SPT的表达,肝细胞凋亡增多.