Esophageal PCO2 as a monitor of perfusion failure during hemorrhagic shock

Sato, Yoji, Max Harry Weil, Wanchun Tang, Shijie Sun,Jianlin Xie, Joe Bisera, and Hidehiro Hosaka. EsophagealPCO₂ as a monitor of perfusionfailure during hemorrhagic shock. J. Appl.Physiol. 82(2): 558-562, 1997.Measurement ofgastric wall PCO₂(Pg_CO2) bytonometric method has emerged as an attractive option for estimatingvisceral perfusion during circulatory shock. However, gastric acidsecretion obfuscates the tonometric measurement. We, therefore,investigated the option of measuringPCO₂ in the esophagus to minimizethese restraints. Hemorrhagic shock was induced in five Sprague-Dawleyrats, and five rats served as sham controls.Pg_CO2 wasmeasured with an ion-sensitive field effect transistor that wassurgically implanted into the gastric wall. Esophageal luminalPCO₂(Pe_CO2) wasmeasured by a second ion-sensitive field effect transistor sensor.During hemorrhagic shock, mean aortic pressure declined from 150 to 50 mmHg. Gastric blood flow decreased from 58 to 12 ml ^· min^{1 ·} 100 g¹ (21% of preshock) andesophageal blood flow from 44 to 7 ml ^· min^{1 ·} 100 g¹ (16% of preshock).Pg_CO2simultaneously increased from 47 to 116 Torr andPe_CO2 from 47 to 127 Torr. The increases inPg_CO2 werehighly correlated with increases inPe_CO2(r = 0.90). Esophageal tonometry may,therefore, serve as a practical alternative to gastric tonometry.

     

Yersinia pseudotuberculosis in China

Thirty strains of Yersinia pseudotuberculosis were isolated from rabbits (17 strains), wild rats (9 strains) and house rats (4 strains) in China between 1990 and 1993. The biochemical properties of these isolates were identical with those of Y. pseudotuberculosis and no special characteristics were found in these strains. Serologically, serogroups 4b and 5b were identical to isolates found in Japan, and a new serogroup 1c and unclassified strains have also been detected. The existence of virulence-associated properties were different among strains. The pYV plasmid was detected from 6 strains of 30 isolates. This report documents the presence of Y. pseudotuberculosis in China, providing important epidemiological information.     

phbB,phbC基因克隆,序列分析及植物表达载体的构建

利用聚合酶链式反应技术,从真养产碱杆菌Ａｌｃａｌｉｇｅｎｅｓ ｅｕｔｒｏｐｈｕｓ Ｈ１６染色体ＤＮＡ中的主增并克隆了调控聚－β－羧基丁酸生物合成的两个关键酶基因;依赖ＮＡＤＰＨ的乙酰乙酰ＣｏＡ还原酶基因和ＰＨＢ合成酶基因。限制性内切酶图谱和核苷酸序列分析证实了克隆结果,并表明所克隆的基因与国外报道的有很高的同源性。     

脱落酸对线粒体Na^＋—K^＋ATPase活性的影响

在提取大豆（Ｇｌｙｃｉｎｅ ｍ ａｘ）黄化子叶的线粒体时,于清洗和悬浮介质中加入ＡＢＡ,发现４０ μｍ ｏｌ／Ｌ（±） ＡＢＡ 对线粒体膜结合Ｎａ＋ －Ｋ＋ ＡＴＰａｓｅ 活性及线粒体吸氧速率有明显的促进作用。ＡＢＡ 可使１６℃与２７℃培养的大豆子叶线粒体膜结合Ｎａ＋ －Ｋ＋ ＡＴＰａｓｅ Ａｒｒｈｅｎｉｕｓ图的折点温度分别下降６．３℃和５．９℃,并将该酶的底物动力学曲线由正协同曲线转变为非协同曲线。表明ＡＢＡ 可降低线粒体的膜相变温度     

菜豆热激蛋白在生物膜上的定位

选用菜豆 Phaseolus vulgris L. 下胚轴 ,运用35S- Met标记放射自显影和二维电泳技术 ,研究热激蛋白 HSPs 的表达和在生物膜组分中的定位 .实验结果表明 ,盐溶蛋白中主要HSPs为 70 k D HSPs和小分子量 HSPs,而小分子量组 HSPs大量富集在质膜和液泡膜组分中 .     

基因转移与肿瘤基因工程疫苗

综述了近年来有关利用基因转移技术修饰肿瘤细胞制备肿瘤基因工程疫苗的最新研究进展,着重阐述了逆转录病毒载体介导的基因转移及其安全性;归纳了目前可用于肿瘤基因工程疫苗的各种目的基因的特点及作用并对这类肿瘤疫苗制备过程中所存在的问题进行了分析.     

一种用聚乙二醇制备微粒体的方法

介绍一种用聚乙二醇(PEG)制备微粒体的方法.大鼠肝匀浆经聚乙二醇-6000凝聚,及两次高速离心即可得到微粒体组分,与超速离心方法比较,可省去超速离心步骤,又缩短了分离制备的时间,是一种比较简单易行的方法．     

人脑神经元特异性烯醇化酶的纯化方法

采用改良的Grace层析方法,经一次DEAE-Sephadex A50柱层析即从人脑中纯化了神经元特异性烯醇化酶,比活力为92.1U/mg,纯化倍数为59.4.该酶纯化后,经SDS-聚丙烯酰胺凝胶电泳鉴定为单一蛋白质谱带.此外,还测定了其部分理化性质,其亚单位分子量为45000,等电点pI为4.7,氨基酸组成分析表明其为一种酸性蛋白质;对2-磷酸甘油酸的K_m值为5.6×10^-4mol/L.     

脱落酸对植物线粒体膜生物物理特性的影响

采用１,６－二苯基－１,３,５－已三乙烯（ＤＰＨ）荧光偏振法和中性红法分别研究了脱落酸（ＡＢＡ）对玉米黄化芽及大豆子叶离体线粒体膜的微粘度（η）、表面电位（ψ）等生物物理特性的影响。结果表明：ＡＢＡ有降低线粒体膜的微粘度及提高线粒体膜的表面电位作用,并导致呼吸速率升高,呼吸控制和氧化磷酸化偶联下降。ＡＢＡ对线粒体膜微粘度的作用具有浓度饱和效应;ＡＢＡ对线粒体膜表面电位的提高作用,因植物不同而有差异,对玉米的作用要大于对大豆的。追踪线粒体Ａ（３５０）值的变化,还证实,ＡＢＡ提高了大豆线粒体的Ａ（３５０）值,即导致大豆线粒体的相互聚集（ａｇｇｒｅｇａｔｉｏｎ）。     

外显子和内含子的序列复杂性

引入了两个新的关于序列复杂性的测度,并以此为指标分析比较了结构基因序列中的外显子和内含子的复杂性差异。