胎盘早剥86 例的临床表征与病因分析

目的:分析胎盘早剥漏诊、误诊原因,提高早期确诊率,降低母儿并发症。方法:回顾性分析我院10年内胎盘早剥患者的临床资料,分析比较胎盘早剥漏诊与误诊原因。结果:过去十年内我院共检测出胎盘早剥86例,发生率为0.46%,该类孕妇临床表现主要为腰腹胀或腹痛、阴道流血、血性羊水。其中,急诊入院患者占(61.6%),有明确诱因39例,占45.3%,且以妊娠期高血压疾病、胎膜早破、外伤性因素为主。B超检出率62.8%。轻型胎盘早剥45例(52.3%),重型胎盘早剥41例(47.7%),出现症状到就诊及处理时间重型胎盘早剥均长于轻型胎盘组P<0.01。剖宫产分娩60例(69.8%),阴道分娩26例(30.2%)。结论:临床发病到临床处理时间是影响胎盘早剥轻重程度的重要因素;胎盘早剥临床表现易与早产、先兆临产或胎儿窘迫等混淆;后壁胎盘发生胎盘早剥时,超声容易漏诊。     

不同叶色红栌叶片中色素含量、酶活性及内含物差异的研究

为明确秋季不同叶色美国红栌叶片的生理差异,以秋季同一植株上红色、中间色、绿色三种颜色的美国红栌叶片为试材,测定了叶片中色素物质含量、酶活性以及叶片可溶性内含物的含量,结果表明：在红色叶片中,叶绿素含量较低,PAL、POD酶活性较高,花青素苷/叶绿素的比值较大,从而使叶色显现红色;而在绿色叶片中,叶绿素含量较高,PAL、POD酶活性较小,花青素苷/叶绿素的比值较低,叶片显现绿色。通过可溶性内含物测定可知,在红色叶片中的可溶性糖和蛋白质含量相对较高,均与花青素苷/叶绿素的比值达到显著相关水平,表明这些内含物的积累有利于花色素苷的合成。     

Ca2+参与茉莉酸诱导蚕豆气孔关闭的信号转导

以Fluo-3AM为Ca~(2 )荧光探针,结合激光共聚焦扫描显微技术,观察到在处理后数十秒内,气孔关闭之前,茉莉酸(JA)可引起[Ca~(2 )]cyt的迅速上升;叶照和JA的前体物亚麻酸(LA)几乎不能引起[Ca~(2 )]cyt的明显变化;钙的螯合剂EGTA预处理可完全阻断JA诱导气孔关闭的效应,并且JA不再引起保卫细胞[Ca~(2 )]cyt增加;质膜Ca~(2 )通道的抑制剂硝苯吡啶(nifedipine,NIF)可减弱JA诱导气孔关闭的效应,也使JA诱导保卫细胞[Ca~(2 )]cyt增加的幅度有所下降;胞内Ca~(2 )释放的抑制剂钌红不能明显改变JA诱导气孔关闭的趋势,但使JA引起的保卫细胞[Ca~(2 )]cyt增加有所降低。实验结果表明:Ca~(2 )参与JA诱导气孔关闭的信号转导;推测JA引起的[Ca~(2 )]cyt升高可能主要来源于胞外,但不能完全排除胞内Ca~(2 )的释放。     

黄瓜育成品种"春玉"RAPD指纹图谱分析

从300条随机引物中筛选出能稳定扩增的26个引物．对黄瓜育成品种“春玉”等21个实验材料进行扩增,在扩增出的173条谱带中,多态性带有80条,比例为46．24％。“春玉”在用引物E13扩增时有特异缺失条带,大小为400bp,可作为特征性指纹图谱,为其产权保护提供分子依据。利用各材料的DNA指纹可将不同参试材料鉴别出来。同时利用MEGA软件进行UPGMA聚类分析,将参试材料在相似系数0．706处分为4个组群。     

放线菌药物资源开发面临的问题与对策

放线菌药物的开发已取得了极其辉煌的成就, 对医疗事业的发展和人类健康做出了重大贡献。然而, 随着放线菌药物资源的长期开发和利用, 也面临诸多问题。如: 包袱沉重, 去重复难度极大, 因而投资周期长、耗资巨, 风险大; 药物开发赶不上病原菌抗药性的增加及不断出现的新疾病; 虽然未知放线菌甚多, 但发现难度大。为此, 提出了从化学、菌种和基因三方面开展放线菌药物研究的应对策略, 以解决限制放线菌药物资源持续利用和发展的瓶颈。     

检测伪狂犬病的PCR方法的建立及其在临床诊断中的应用

根据文献,通过计算机分析设计并合成了1对用于扩增伪狂犬病病毒(pseudorabies virus,PRV)gB基因281bp片段的引物,上游引物(P1)位于gB基因的1827～1851位,下游引物(P2)位于gB基因的2083～2107位.以PRV闽A株细胞培养毒为模板,筛选最佳反应条件和试剂工作浓度,建立了检测PRV的PCR方法.应用该方法对保存的16株伪狂犬病强弱毒株的细胞培养液进行基因扩增,均获得了281bp的特异性目的DNA片段.可是,对正常细胞与其它6种引起猪病毒性疫病相关病毒进行检测,结果均为阴性,没有出现交叉反应.对扩增产物测序,结果序列与文献报道一致,证明PCR扩增产物和方法的特异性.对PRV闽A株细胞毒提取物DNA进行检测,其最低检出量为15.8pg.用病毒分离、双抗体夹心ELISA和PCR等3种方法检测1994～2000年期间送检的临床样品和保存的PRV毒种,对所获得的结果进行χ2分析,证明PCR检出率明显高于前2种方法.对1999～2001年期间广东、福建、海南等省的76个大中型猪场送检的348份病料进行检测,检出阳性病料68份,病料阳性率为19.54%;检出阳性猪场27个,猪场阳性率为35.53%.对27个阳性猪场分析发现,种猪场阳性率为7.41%(2/27),商品猪场阳性率为92.59%(25/27).PRV在自然发病猪体内分布较广,脑、肾、肺、脾、肝、淋巴结均有PRV的存在,PRV检出率最高的组织为脑,其检出率为5/5,依次为肾12/15、肺9/16、脾10/20、肝7/18、淋巴结4/11等.实验结果表明,所建立的PCR技术可用于伪狂犬病的快速诊断和流行病学调查.     

细菌质粒的消除

利用化学消除剂或改变生长条件可以消除细菌中的质粒,除宿主菌的特性及其所含质粒分子量大小之外,消除率还与消除剂浓度,作用时间有关,嵌合染料适用于消除大肠杆菌中的质粒,十二烷基硫酸钠对具有性纤毛的细菌作用效果较好,适当提高培养温度可消除一些细菌中的质粒,胸腺嘧啶限量法仅适用于其营养缺陷菌株的质粒消除,利用原生质体的形成与再生及反复冻融菌体均可消除细菌中的质粒。     

ROLE OF RICE VOLATILES IN THE FORAGING BEHAVIOUR OF CYRTORHINUS LIVIDIPENNIS REUTER

Abstract Experiments were conducted in laboratory to study the impacts of rice genotypes and nitrogen levels on the preference of the egg predator, Cyrtorhinus lividipennis , for eggs of brown planthopper(BPH), Nilaparvata lugens (Stal), and their relation to the rice volatiles. In two-choice tests, the female predators showed different preference for BPH eggs on different rice genotypes, but not for BPH eggs on rice plants treated with different levels of nitrogen. The olfactory response test revealed that more predator oriented to the odour from healthy rice plants compared with the plain air (control); the predator preferred BPH nymph-damaged plants to healthy plants, and BPH female adult-damaged plants to BPH nymph-damaged plants. The comparative studies between rice genotypes and nitrogen levels indicated that there were obvious differences in attractiveness to the predator between rice genotypes, while there was no significant difference between rice plants treated with different levels of nitrogen. The results showed that rice volatiles played an important role in mediating the foraging behaviour of C. lividipennis . Implications for augmenting the effectiveness of natural enemies by adjusting rice attributes and cultural practices are discussed.     

CH4 emission with differences in atmospheric CO2 enrichment and rice cultivars in a Japanese paddy soil

A pot experiment was conducted to investigate CH₄ emissions from a sandy paddy soil as influenced by rice cultivars and atmospheric CO₂ elevation. The experiment with two CO₂ levels, 370 μL L⁻¹ (ambient) and 570 μL L⁻¹ (elevated), was performed in a climatron, located at the National Institute for Agro‐Environmental Sciences, Tsukuba, Japan. Four rice cultivars were tested in this experiment, including IR65598, IR72, Dular and Koshihikari. Tiller number, root length and grain yield were clearly larger under elevated CO₂ than under ambient CO₂. IR72 and Dular showed significantly higher tiller number, root length and grain yield than Koshihikari and IR65598. Average daily CH₄ fluxes under elevated CO₂ were significantly larger by 10.9–23.8% than those under ambient CO₂, and varied with the cultivars in the sequence Dular ≧ IR72>IR65598 ≧ Koshihikari. Dissolved organic C (DOC) content in the soil was obviously higher under elevated CO₂ than under ambient CO₂ and differed among the cultivars, in the sequence IR72>Dular>Koshihikari>IR65598. The differences in average daily CH₄ fluxes between CO₂ levels and among the cultivars were related to different root exudation as DOC content, root length and tiller number. This study indicated that Koshihikari should be a potential cultivar for mitigating CH₄ emission and simultaneously keeping stable grain yield, because this cultivar emitted lowest CH₄ emission and produced medium grain yield.     

外泌体源性miRNAs在肺癌发生发展中的作用

外泌体(exosomes)是细胞分泌的纳米级细胞外囊泡.外泌体通过释放其内的生物活性大分子,比如微小RNA(microRNA,miRNA)到受体细胞,从而介导细胞间交流通讯. MiRNAs作为一类主要在转录后水平负向调控靶mRNAs的非编码RNAs,其在外泌体中含量最为丰富.在肺癌中,miRNAs经肿瘤细胞分泌的外泌体转运释放而发挥重要的作用.本文主要讨论了外泌体源性miRNAs在肺癌发生发展的各个阶段,包括血管生成、细胞增殖、侵袭转移、免疫逃逸、耐药等方面的作用,以及其在作为新型肺癌诊断和预后标志物方面的临床价值.