Therapeutic effects of recombinant human growth hormone on rat sepsis

AIM:To investigate therapeutic effects of recombinant human growth hormone(rhGH) on rat sepsis and its possible mechanisms.METHODS:Mean arterial pressure (MAP), levels of plasma TNFα, IL-1β and endotoxin, leukocyte count and survival rate within 1 week were determined after E. coli injection among control group, sepsis group and sepsis+rhGH group.RESULTS:(1)rhGH diminished the decrease of MAP, reduced plasma endotoxin and TNFα levels and increased neutrophil ratio in total leukocytes in sepsis rat. rhGH increased survival rate within 1 week on sepsis rat. (2)No changes were found in IL-1β level among the three groups.CONCLUSION:rhGH showed desirable beneficial effects on rat sepsis, which may attribute to: improving circulatory function;maintaining intestinal mucosa barrier, attenuating bacteria/endotoxin translocation and inhibiting the production and release of TNFα.     

Effect of fibronectin on proliferation and collagen synthesis in cardiac fibroblasts from spontaneously hypertensive rats

AIM:To investigate the effects of fibronectin (FN) on the proliferation and collagen synthesis in cultured rat cardiac fibroblasts (CFb) derived from SHR (CFb_SHR) and WKY (CFb_WKY). METHODS:CFb derived from 12-week-old spontaneously hypertensive rat (SHR) and WKY was cultured by outgrowth of tissue block. Cell proliferation of CFb was measured by cell number counting and[³H]-TdR incorporation using 24-well plates pre-coated with 5 μg/cm² of FN. Collagen synthesis was determined by [³H]-proline incorporation. RESULTS:As compared with control, the cell number of fibroblasts derived from SHR and WKY were significantly increased to 163.75% and 170.42% respectively after 72 h incubation with FN in the presence of 0.4% FCS from a intial cell density of 1×10⁴ cells/mL. DNA synthesis of CFb was markedly promoted by FN. FN induced an increased in [³H]-proline incorporation in both CFb_SHR and CFb_WKY. CONCLUSION:FN is able to promote cell proliferation and collagen synthesis of CFb derived both from SHR and WKY.     

麦二叉蚜传播玉米矮花叶病毒的机制

用胶体金标记法和荧光抗体标记法研究了麦二叉蚜(Schizaphis graminum)传播玉米矮花叶病毒(Maize dwaft mosaic virus,MDMV)的机制。麦二叉蚜传播玉米矮花叶病毒需要辅助成份-蛋白酶(Helper component-proteinase,HC-Pro)的参与。在电镜下观察到HC-Pro可以与MDMV粒子结合。用FITC标记的HC-Pro抗体和MDMV抗体证明,HC-Pro可以直接结合到蚜虫口针上;而MDMV粒子不能直接结合到蚜虫口针,必须在HC-Pro的辅助下才能结合到蚜虫口针上。这为HC-Pro在蚜虫传毒过程中起桥梁作用提供了新的证据。MDMV粒子主要吸附在蚜虫口针的尖端和中间部分。     

十种常用农药与球孢白僵菌的生物学相容性

球孢白僵菌孢子粉与10种常用农药相容性的测定结果显示,随着孢子浓度上升,所试农药对孢子的抑制作用均有不同程度的增强。在1/10田间常规使用浓度下,百菌清和代森锰锌均能抑制或杀死孢子(萌发率<1％)。除阿维菌素外,所有杀虫剂均与白僵菌孢子相容,在常规使用浓度的10倍稀释液中孢子萌发率达90％以上。吡虫啉、蚜虱灵、灭多威和氟虫腈与孢子的相容性最好,其中吡虫啉和蚜虱灵对孢子萌发率的影响不明显随药剂浓度的变化而变化,即使在田间常规使用浓度下孢子萌发率也在95％以上,而阿维菌素与白僵菌的相容性极差。因此,应用白僵菌制剂防治害虫,选择生物学相容性好的农药以低剂量与白僵菌制剂混用,既可使菌剂增效,又可大幅度降低化学药剂用量。     

一种监测棉铃虫对Bt杀虫晶体蛋白抗性的技术

研究了以诊断试剂盒监测棉铃虫对苏云金杆菌(Bt)杀虫晶体蛋白(ICP)抗性的技术。将1日龄幼虫在含诊断剂量的饲料中(每毫升饲料含Bt ICP0.01mg)取食7天,以生长至3龄以上的个体作为抗性个体的判断指标;筛选出人工饲料中防腐剂剂量的最佳值为每350毫升饲料中含丙酸2.5ml。经对多个棉铃虫不同抗性种群的验证试验,证明诊断试剂盒检测抗性个体频率较为精确且应用简便。     

钙素对叶用莴苣营养吸收和生长发育的影响

 采用NFT 栽培, 研究了叶用莴苣钙素与主要无机成分间的相互关系, 以及对叶用莴苣生长发育的影响。结果表明, 缺钙胁迫引起叶绿素含量降低, 缘腐病发病率上升, 叶片干、鲜样质量降低。生长中后期, 特别是新生内叶易发生钙素营养失调症。营养液中钙浓度过高会降低钾、镁的吸收, 而对氮、磷吸收影响不大。提高营养液中NH₄⁺ -N 比例会抑制钙吸收, 降低其有效性。     

苹果梨中多酚氧化酶酶学特性的研究

 以苹果梨中的多酚氧化酶为研究对象, 对其酶的活性变化及其特性的研究表明, 苹果梨中的多酚氧化酶的最适pH 值是4. 6 , 最适温度是40 ℃; 亚硫酸氢钠、维生素C、柠檬酸对苹果梨中多酚氧化酶的抑制作用依次减弱, 硫酸钠几乎无抑制作用。不同底物和同底物不同浓度影响多酚氧化酶特性。     

十五种柑桔种质资源的RAPD分析

对柑桔15个材料（其中包含14个种，1个为品种）进行了RAPD分析，从结果看，各材料之间具有不同的遗传距离，供试材料聚为8个类群，分别为柠檬，柠檬群；香橼，小香橼群；柚，红心柚群；宜昌橙，香圆群；香橙，大翼橙群；红桔，温州蜜柑群；枳登，富民枳群；枳群。采用RAPD技术可作为品种鉴别，亲缘关系和分类的手段。对所得结果进行了讨论。     

灰树花不同菌株液体深层培养蛋白质含量的测定

在液体培养条件下测定了发酵液中5个灰树花菌株蛋白质含量的变化。结果表明，接种后第6天发酵液中蛋白质含量最高，Gf961菌株发酵液中的蛋白质含量为0.58%，Gf962菌株发酵液中的蛋白质含量最低，为0.30%，随着培养时间的延长，发酵液中蛋白质含量逐渐下降，接种后第9天最低，随后以呈上升趋势。但上升的幅度较小。试验为确定从发酵液中提取蛋白质的最佳时期提供了一定的理论依据。     

Study on integrin-mediated albumin microbubbles adherence to activated leukocytes

AIM:To investigate the mechanism responsible for albumin microbubbles adherence to activated leukocytes. METHODS: In vitro studies were performed in which activated or nonactivated leukocytes were incubated with albumin microbubbles and observed under microscopy. The suspensions of leukocytes and microbubbles which contained or absented of integrins were analyzed with flow cytometry.RESULTS: A minimum of 50cells were identified under transillumination. 5 min after microbubbles were incubated with leukocytes, the number of cells interacting with microbubbles was greater for activated cells than for nonactivated cells(20.30±2.67 vs 4.50±1.43, P <0.01).Microbubbles attached to the surface of activated leukocytes were phagocytosed and remained intact for up to 30min. Microbubble attachment was inhibited notably by blocking the leukocyte β₂-integrin Mac-1(P <0.01) and by VLA-4mAb slightly(P <0.05) CONCLUSION: The mechanism of albumin microbubbles attaching to and phagocytosed by leukocytes was due to β₂-integrin and VLA-4 mediation. Phagocytosed microbubbles can remain at the regions of inflammation for15 min, also responsible to ultrasound.