High-throughput screening reveals small molecule modulators inhibitory to Acidovorax citrulli

Acidovorax citrulli is a seed-transmitted gram-negative bacterium that can cause substantial economic yield loss in watermelon and melon production worldwide. Four small-molecule libraries containing 4,952 compounds were selected for high-throughput screening against A. citrulli wild-type strain Xu3-14 by evaluation of growth inhibition. One hundred and twenty-seven molecules (2.5% hit rate) were identified as bactericidal or bacteriostatic against A. citrulli at 100 μM. Secondary screens indicated that 27 candidate compounds were more effective against A. citrulli Group II strains than Group I strains (classified using repetitive element PCR). Several compounds were inhibitory to other pathogenic bacteria, including Clavibacter michiganensis subsp. michiganensis and Xanthomonas campestris pv. campestris, but did not affect the growth of plant beneficial bacteria Pseudomonas fluorescens and Bacillus subtilis. More than half of the compounds did not inhibit germination of Arabidopsis or watermelon seeds. The effect of small molecules on A. citrulli seed-to-seedling transmission was evaluated by applying each compound to inoculated watermelon seeds and assessing seedling infection. Nine compounds were chosen for further investigation based on their reduction of percentage seedling infection and compiling scores on their specificity, sensitivity, and phytotoxicity obtained in the secondary screens. The five best compounds were selected (thiamphenicol, nadifloxacin, pipemidic acid, ciclopirox, and zinc pyrithione) for greenhouse tests and were found to effectively reduce the seed-to-seedling transmission of A. citrulli in both artificially and naturally infested seeds. These top five compounds provide a basis for future development of an A. citrulli-specific bactericide.     

液态奶生产新设备和工艺

液态奶包括巴氏杀菌奶、UHT超高温灭菌奶等。目前国内采用的液态奶杀菌工艺是热处理法。但通过热处理法的液态奶仍可能残留休眠芽孢,给液态奶产品带来潜在风险。本文通过研究目前液态奶杀菌工艺的种类和存在问题,申报了发明专利“一种能延长液态奶保质期的生产方法”和“一种能使液体隔离空气的无菌罐体”,并利用氢医学制作含氢乳制品,实现了提高液态奶品质,延长保质期,获得氢分子医学效应。     

一氧化碳(CO)在植物体内的生理生化作用研究进展

为了促进一氧化碳(CO)在植物生理生化方面的研究,本文归纳了CO在植物体中的生物合成途径,CO作为信号分子对植物各种生理功能的调控,以及CO与其他信号分子之间的相互作用。经过分析得出,CO在植物生物胁迫过程中的作用及其作用机制方面的研究还很少,因此,CO在这方面的研究将会成为今后的研究重点。     

益气活血法对冠心病稳定型心绞痛气虚血癖证 患者血清IL-6,TNF-。及ICAIVI-1的影响

〔摘要〕目的观察益气活血之保心汤对气虚血疲型冠心病稳定型心绞痛患者的疗效及对血清白介素一6 ( IL- 6)、肿瘤坏死因子一。(TNF-a)、细胞间粘附分子一1(ICAM-1)的影响〔方法60例患者随机分为治疗组和对照组,分 别采用保心汤和西药治疗4周后,观察两组治疗心绞痛的疗效和患者治疗前后血清IL-6 ,TNF-a ,ICAM-1水平的 变化〔结果治疗组疗效评价明显优于对照组((P<0.05) ;治疗组患者治疗后血清IL-6 ,TNF-a ,ICAM-1水平较治疗前 明显降低(P<0.01)结论保心汤对气虚血疲型冠心病心绞痛患者有确切的疗效,可能通过抑制血清IL-6,TNF-a, TCAM-1 iK平_从而抑制}h''}}应_以iJ.- }}I疗冠心病}.} }.h ''J ,I`} }u痛的作用.     

水稻病原菌Burkholderia plantarii群体感应和群体淬灭研究进展

植物伯克霍尔德菌Burkholderia plantarii是引起水稻秧苗细菌性立枯病的重要病原菌之一,其侵染性、繁殖力及适应性均很强,严重威胁中国水稻生产。文章围绕B.plantarii的发生、危害及致病机理,着重论述了细菌群体感应系统(quorum sensing,QS)的生理功能及其在B.plantarii致病力调控方面的最新研究进展,并进一步从根际微生物互作角度,综述了种间信号分子对病原菌群体淬灭(quorum quenching)的作用机制,同时结合种间信号分子的独特性,展望了其在新型微生物杀菌剂研发中的重要性和应用潜力。     

接头分子在TLRs信号传导中的作用研究进展

接头分子在Toll样受体(Toll like receptors,TLRs)识别病原相关分子模式或损伤相关分子模式、发动和调节先天与后天免疫反应的信号传导网络中发挥着重要的生物学作用,与Toll样受体相结合后,其下游激酶和转录因子传导信号,激活细胞内核转录因子调控作用元件。TLRs接头分子的共同特征是含有TIR结构域,不同TLRs家族成员可依赖于一个或多个接头分子传导信号。对目前已确认的MyD88、MAL/TIRAP、TRIF、TRAM和SARM 5种接头分子在TLRs信号传导途径中的调控作用进行综述,以期为研究接头分子在TLRs信号传导中的作用机制提供参考。     

Effects on adhesion molecule expression and lymphocytes in the bovine mammary gland following intra-mammary immunisation

Changes to adhesion molecule expression and lymphocyte populations were evaluated in alveolar mammary tissue collected from cows following an immunisation protocol that involved intra-mammary inoculation to induce an IgA response in mammary secretions. The right quarters of the udder were immunised; the left side acted as a control. Antibody titres in secretions showed that at least two animals responded with antigen-specific IgA. Numbers of T-lymphocytes were 4-fold higher in immunised glands compared with controls (P < 0.05). IgA-, IgM- and IgG-positive cell numbers were significantly higher (P < 0.01) in immunised glands compared with controls in three of the four cows. No mucosal addressin molecule-1 (MAdCAM-1), vascular cell-adhesion molecule-1 (VCAM-1) or peripheral node addressin (PNAd) protein expression was detected on smaller venules that stained positively for von Willebrand factor in alveolar mammary tissues, from either immunised or control glands. Both VCAM-1 and PNAd were detected on smaller venules in supramammary lymph nodes, however, there was no significant difference between immunised and control glands. Quantification of MAdCAM-1 mRNA showed very low expression in both immunised and control alveolar tissue compared with Peyer's patch positive-control tissue. These findings suggest that the bovine mammary gland is capable of a mucosal antibody response; however, MAdCAM-1 is not involved with lymphocyte homing to the mammary gland in this species.     

Summary of workshop findings for porcine adhesion molecule subgroup

Fifty-nine monoclonal antibodies (mAb) were assigned to the adhesion section of the Second International Swine CD Workshop. They were analysed for their reactivity to selected lymphoid cell populations, as well as to non-lymphoid cell lines. Cell lysate ELISAS and Western Blot analyses were also carried out. As a result, thirteen separate cluster groups emerged (p>0.95). Workshop assignments for adhesion molecules were made: wCD29/49 for mAbs UCP1D2 (#133) and FW4-101 (#165), and PNK-I (#194) and MUC76A (#025) could be assigned to wCD18. For one cluster (FQ1D7, #161 and 2F4, #069) the cellular distribution and MW were characteristic for MHC Class II, and another cluster comprising several antibodies which appeared to recognise MHC Class I. Other clusters could not be assigned to cell surface structures known to be linked to cellular adhesion, however, two further antibodies, 335-2 (#112) and FG1F6 (#156), could be added to SWC1, and the new SWC8 was defined by MIL3 (#077) and MUC20A (#029), binding a ligand of 29–32 kDa. Clustering for these two antibodies was confirmed by blocking studies. The cellular distribution is known for MIL3, recognising an epitope present on granulocytes, B cells, and a subset of T cells expressing CD8 at high intensity.     

Expression of intercellular adhesion molecule in lung tissues of experimental acute lung injury and the effect of rhubarb

AIM:To approach the relationship between the expression of intercellular adhesion (ICAM-1 mRNA) and acute lung injury (ALI) as well as the mechanisms of rhubarb in the prevention and treatment of the lung injury. METHODS:ALI animal model was performed by Lipopolysaccharide (LPS). The rats were divided into 4 groups: LPS group, control group, rhubarb+LPS group and dexamethasone+LPS group. Histopathological examination and biological markers were measured for the lung specimens. Molecular hybridization method was used to determine the expression of ICAM-1 mRNA. RESULTS:The ICAM-1 mRNA expression in the lung tissues of LPS group significantly increased compared with control group (P＜0.01), rhubarb and dexamethasone had the action of decreasing the ICAM-1 mRNA expression (P＜0.05, P＜0.01); pathologic changes and the biological markers of ALI significantly decreased or ameliorated. CONCLUSION:The increase in the expression of ICAM-1 mRNA in the lung tissues of ALI is involved in the formation of ALI. Rhubarb and dexamethasone can ameliorate the lung damage, mechanism of which may be related to the inhibition of ICAM-1 mRNA expression.     

光合膜蛋白复合物中的脂分子和色素分子的概述

介绍了植物类囊体膜上光合膜蛋白中的脂分子及其作用,同时介绍了植物类囊体膜上的色素分子。其中,PSII单体有25个脂分子和35个叶绿素a分子,Cyt b6f有3个脂分子、1个叶绿素a分子和1个类胡萝卜素分子,PSI单体有4个脂分子和167个叶绿素分子。