Protection against nontypeable Haemophilus influenzae challenges by mucosal vaccination with a detoxified lipooligosaccharide conjugate in two chinchilla models

Otitis media (OM) can occur following outset of upper respiratory tract infections. Inhibition of bacterial colonization in nasopharynx (NP) by mucosal vaccination may prevent OM by reducing bacterial invasion of the middle ears (MEs). In this study, 80 chinchillas were intranasally (i.n.) immunized with a detoxified lipooligosaccharide (dLOS)-tetanus toxoid conjugate vaccine of nontypeable Haemophilus influenzae (NTHi) mixed with cholera toxin (CT) or CT alone. All vaccinated animals responded with elevated levels of mucosal and serum anti-LOS antibodies. Two weeks after the last immunization, 40 chinchillas were challenged i.n. with NTHi to evaluate NP colonization and ME infection while the rest of the animals were challenged transbullarly (T.B.) to examine the development of OM. Compared to the control group, the vaccination inhibited not only bacterial colonization in NP and transmission to MEs in the i.n. challenge group but also bacterial colonization in NP and transmission to unchallenged ears in the T.B. challenge group. Though no difference was found in the challenged ears of either group right after the T.B. challenge, an early clearance of NTHi from NP and unchallenged ears as well as less severity of OM in the unchallenged ears were observed in vaccinated animals. Current results along with our previous data indicate that mucosal vaccination is capable of inhibiting NTHi NP colonization and preventing OM occurrence in chinchillas; the i.n. challenge model is preferable for testing the mucosal vaccines while the T.B. challenge model is superior for testing the systemic vaccines.     

脑红蛋白与Na^＋，K^＋-ATP酶β2亚基的相互作用及作用位点的鉴定

为研究神经系统特异性携氧蛋白———脑红蛋白 (NGB)保护神经元耐受缺氧损伤的分子机制 ,利用酵母双杂交系统从人胎脑cDNA文库中筛选与其有相互作用的蛋白质。序列分析表明 ,其中一个克隆的编码产物与Na ,K ATP酶 β2亚基 (NKA1b2 )序列一致。随后采用PCR方法从人胎脑cDNA文库中扩增获得NKA1b2全长cDNA。蛋白质结合实验表明 ,原核表达的NGB与体外转录翻译得到的NKA1b2在细胞外有结合作用。免疫共沉淀实验证明二者在生理条件下能够以复合物的形式存在。利用NGB系列短截体研究相互作用的位点发现 ,NGB蛋白N末端 1～ 75位氨基酸可与NKA1b2结合 ,但结合力很弱 ,而其C末端 75个氨基酸则与NKA1b2无结合作用 ,由此推测NGB蛋白整体的三维结构是结合所必需的。     

柠檬酸钠对枯草杆菌生长代谢及肌苷积累的影响

研究柠檬酸钠对枯草杆菌生长代谢及产苷的影响 ,在基础料中添加浓度为 0 2g L的柠檬酸钠 ,肌苷产量提高 18% ,肌苷对葡萄糖得率增加 38%。通过分析糖代谢途径中关键酶的酶活 ,结果表明添加柠檬酸钠改变了一些关键酶的活力 ,可降低糖酵解途径中 6_磷酸果糖激酶和丙酮酸激酶的活力 ,从而减弱了糖酵解途径的通量。     

Moraxella catarrhalis lipooligosaccharide selectively upregulates ICAM-1 expression on human monocytes and stimulates adjacent naïve monocytes to produce TNF-alpha through cellular cross-talk

To elucidate the role of Moraxella catarrhalis lipooligosaccharide (LOS) in otitis media with effusion (OME), the effects of LOS on adhesion antigens of human monocytes were investigated. M. catarrhalis LOS selectively enhanced intercellular adhesion molecule 1 (ICAM-1 or CD54) expression on human monocytes by significantly increasing both the surface expression intensity and the percentage of ICAM-1⁺ cells. ICAM-1 upregulation on human monocytes by the LOS required surface CD14, TLR4, NF-κB p65 and c-Jun N-terminal kinase (JNK) activity. Our study also revealed that the LOS-induced surface ICAM-1 expression was partially mediated through a TNF-α dependent autocrine mechanism and could be further augmented by lipopolysaccharide-binding protein in serum. In addition, M. catarrhalis LOS also stimulated human monocytes to produce pro-inflammatory cytokines in both TLR4- and CD14-dependent pathways. Our results also indicated that enhanced surface ICAM-1 expression on monocytes may hinder their adherence to the lung epithelial monolayer. Furthermore, the LOS-activated human monocytes secreted a significantly high level of IL-8, and could stimulate adjacent naïve monocytes to produce TNF-α which was partially mediated via membrane ICAM-1 and IL-8/IL-8RA. These results suggest that M. catarrhalis LOS could induce excessive middle ear inflammation through a cellular cross-talk mechanism during OME.     

叶绿素缺乏的大麦突变体的光合作用和叶绿素荧光

和早熟３号大麦（野生型）（ＤＧ）相比,黄化大麦（突变体）（ＬＧ）叶片Ｃｈｌ含量低,而Ｃｈｌａ／ｂ较高;光合速率低,表现量子效率低,而饱和光强较高,气孔导度较高;荧光参数Ｆｏ低,而ＰＳⅡ的光化学效率（Ｆｖ／Ｆｍ）以及Ｔ１／２、Ｆｍ／Ｆｏ、Φｅ均高。以单位叶绿素计算,黄化大麦的ＰＳⅡ电子传递活性和全链电子传递活性较高,而ＰＳⅠ电子传递活性较低。推测黄化大麦ＰＳⅡ的光化学效率增高可能是由于其ＰＳⅡ向ＰＳⅠ传递的激发能较少,是对Ｃｈｌ含量低的一种补偿。     

水解鱼蛋白对大菱鲆幼鱼消化率的影响

设计5组等氮等脂等能的饲料, 在室内流水系统进行68d的养殖实验, 探讨高植物蛋白饲料中添加不同分子量水解鱼蛋白对大菱鲆Scophthalmus maximus L.（16.050.03） g幼鱼消化能力的影响。分别在高植物蛋白饲料中添加5.4%超滤水解鱼蛋白（UF）、5.5%未经超滤水解鱼蛋白（FPH）、5.5%超滤截留水解鱼蛋白（RF）, 其均占饲料蛋白的10%, 以及不添加水解蛋白（PP）, 以上各组鱼粉含量均为18%, 对照组（FM）鱼粉含量为67.5%。研究结果表明, FM组的大菱鲆特定生长率与UF、FPH及PP组无显著差异（P0.05）; 饲料效率、蛋白质效率和蛋白质沉积率在FM组与UF组无显著差异（P0.05）, 但显著高于FPH、RF及PP组（P0.05）; 饲料干物质和蛋白质消化率在UF、FPH及RF组显著高于PP组（P0.05）, 但显著低于FM组（P0.05）, 在UF组显著高于FPH和RF组（P0.05）; 不同处理对饲料氨基酸和牛磺酸的消化率均产生显著影响（P0.05）, 趋势为FM组最高, 其次为UF组, PP组最低; 半胱氨酸和牛磺酸的消化率在添加水解鱼蛋白的3组（UF、FPH和RF组）和不添加水解鱼蛋白的2组（FM和PP组）呈相反的趋势。上述结果表明, 在高植物蛋白饲料中添加低分子量水解鱼蛋白（UF）, 大菱鲆幼鱼的生长和饲料利用有升高的趋势, 但UF、FPH以及RF都显著提高了大菱鲆对饲料干物质、蛋白质和氨基酸的消化率, 且UF效果优于FPH和RF。此外, 添加不同分子量水解鱼蛋白都降低了牛磺酸的消化率。       

核转录因子TR3小干扰RNA载体的构建及其效果鉴定

目的：构建核孤儿受体TR3的小干扰RNA（siRNA）真核表达载体,并进行沉默效果测定。方法：根据TR3 mRNA序列和载体psiSTRIKE的粘性末端,设计合成TR3的干扰RNA序列,退火后克隆至psiSTRIKE,经测序鉴定后用阳离子脂质体将重组子和TR3高表达载体TR3-pcDNA共转染至HEK293细胞中,以Western blotting检测干扰后HEK293细胞内TR3表达的变化。结果：Western blotting检测结果证实构建的TR3 siRNA表达重组载体可显著抑制HEK293细胞内TR3的高表达。结论：构建了核孤儿受体TR3 siRNA真核表达载体。     

Identification of a RAPD Marker Linked to Fusarium Wilt Resistant Gene in Wild Watermelon Germplasm (Citrullus lanatus var. citroides

Random amplified polymorphic DNA(RAPD) was employed to detect a molecular marker linked to Fusarium wilt resistant gene in the wild watermelon ( Citrullus lanatus (Thunb.) Mansfeld var. citroides ) germplasm P1296341. The resistance to race 1 Fusarium wilt of PI296341 was controlled by one dominant gene. A RAPD marker OPPO1/700 was proved to be linked to the resistant gene. The genetic distance is 3.0 cM (centimorgan). This work has provided a solid basis for molecular marker-assisted selection (MAS) for disease resistance, and made location and cloning of disease resistant genes possible.