Protein-protein- and protein-RNA-binding properties of the movement protein and VP25 coat protein of Apple latent spherical virus

To elucidate the mechanism of Apple latent spherical virus (ALSV) movement, various properties of its cell-to-cell movement protein (MP) were analyzed. ELISA and blot overlay assays demonstrated that the MP bound specifically to ALSV virions and in particular to one of the three coat proteins (VP25) but not to the other two coat proteins (VP20 and VP24). Mutational analyses have revealed that the MP contains two domains with independent VP25-binding activity (amino acid residues 1-188 and 189-281). Furthermore, nucleotide-binding experiments showed that the MP and VP25 bound to single-stranded RNA (ssRNA) and ssDNA without any sequence specificity, but these two proteins did not bind to double-stranded RNA (dsRNA) and dsDNA. The MP contains three potentially independent single-stranded nucleic acid-binding domains between amino acid residues 95-188, 189-281 and 277-376. The MP demonstrated cooperative and VP25 demonstrated non-cooperative binding to ssRNA in gel-retardation analyses. The cooperative RNA binding of the MP became non-cooperative when MP and VP25 were tested together in competition binding experiments, even though a sufficient amount of the MP for fully cooperative RNA binding the MP was supplied. The roles of the MP and VP25 interactions and nucleic acid binding activities in ALSV movement are discussed.     

Food Allergy Overview in Children

Food allergies have increased significantly in the past decade. An accurate history is crucial in approaching the management. At the outset, food intolerance must be distinguished from food allergies and, furthermore, these allergies should be classified into either an IgE, Non-IgE, or a mixed response. The clinical features vary from life-threatening anaphylaxis to milder IgE-mediated responses, atopic dermatitis, and gastrointestinal symptoms. The severity of the reaction and the potential risk for anaphylaxis on reexposure should be assessed. Milk, soy, egg, wheat, and peanut allergies are common in children, whereas peanut, tree nut, fish, shell fish allergies, and allergies to fruits and vegetables are common in adults. Structural proteins are important determinants of the severity of the reactions and may often predict the natural history and cross reactivity. Diagnostic work up must be guided by the clinical history. Skin testing and food-specific IgE done by standard methods are very useful, whereas oral challenges may be indicated in some situations. Majority of the patients outgrow their allergies to milk, soy, egg, and wheat, and some to peanut also, therefore, patients should be periodically reassessed. Novel diagnostic techniques which detect specific allergenic epitopes have been developed. Several newer therapies are promising.     

复方黄芪提取物抗急性肝损伤作用的研究

目的：研究复方黄芪提取物（ERAC）的抗急性肝损伤作用。方法：分别采用D-氨基半乳糖（D-Galn）和四氯化碳（CCl4）造成急性肝损伤模型,检测血清中丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）的活性及胆红素的含量,并进行病理学检查。结果：ERAC对肝损伤引起的ALT和AST活性增加以及胆红素增高均有明显的降低作用（P<0.05）。病理组织学检查：ERAC对肝损伤引起的肝细胞变性、坏死等病变有改善作用。结论：ERAC能减轻D-Galn和CCl4所引起的肝损伤,改善肝功能。     

植物抗体及其应用

20世纪80年代末科学家将抗体基因转入烟草表达,标志着植物抗体的诞生.人类既可以以植物为生物反应器异源表达和生产具有药用及商业价值的蛋白质;也可用抗体在植物体中进行免疫调节,以研究植物生理代谢机制,或增加植物抵抗病虫害的能力.本文旨对植物抗体的优越性、表达生产及其在医药学、植物抗病及代谢等领域的进展进行综述和讨论.     

Silencing suppressor activity of the Tobacco rattle virus-encoded 16-kDa protein and interference with endogenous small RNA-guided regulatory pathways

Higher plants use RNA silencing as a defense mechanism against viral infections, but viruses may encode suppressor proteins that counteract these defenses. Several virus-encoded suppressors also exert an inhibitory effect on endogenous small RNA regulatory pathways. Here we characterized the Tobacco rattle virus-encoded 16-kDa (TRV-16K) protein as a suppressor that blocked local RNA silencing induced by single (s)- and double-stranded (ds) RNA, indicating that TRV-16K interfered with a step in the silencing pathway downstream of dsRNA formation. The suppressor activity of TRV-16K was severely compromised by moderate to high dosages of dsRNA inducer. When silencing was locally triggered by ssRNA or low levels of dsRNA, silencing suppression by TRV-16K was associated with reduced accumulation of silencing-related siRNAs. TRV-16K also prevented partially cell-to-cell movement and systemic propagation of silencing but not transitive amplification of RNA silencing. We showed that neither TRV nor TRV-16K caused a global deregulation of the microRNA-regulatory pathway in Arabidopsis, suggesting that interference with microRNA biology was not a prerequisite for TRV, and probably many other plant viruses, to develop systemic infections in plants.     

“螺威”植物杀螺剂现场灭螺效果研究与示范Ⅲ山丘地区喷洒灭螺效果

目的 目的 评价植物杀螺剂4%螺威 （TDS） 在山丘地区现场灭螺效果, 为现场应用提供科学依据。方法 方法 在南京市江 宁区湖山村选择钉螺密度相对较高的环境, 采用5 g/m2 TDS和2 g/m2 50%氯硝柳胺乙醇胺盐 （WPN） 进行喷洒灭螺试验, 比 较不同时间不同药物的现场灭螺效果。结果 结果 灭螺后1、 3、 7、 15 d TDS组钉螺死亡率为56.47%、 57.32%和90.58%、 93.41%, WPN组钉螺死亡率为49.22%、 53.37%、 95.92%和97.26%, 灭螺后1、 7 d和15 d两组钉螺死亡率之间差异有统计学 意义 （P均＜0.05）; 灭螺后15 d, TDS组和WPN组活螺密度分别由20.30±16.20只/0.1 m2 和23.67±21.22只/0.1 m2 下降至 2.28±2.17只/0.1 m2 和1.27±0.76只/0.1 m2 , 钉螺密度下降率分别为88.77%和94.63%。结论 结论 TDS可作为山丘地区的备选灭 螺药物之一, 值得进一步推广应用。     

Antimicrobial Activity of Various Extracts of Ocimum Basilicum L. and Observation of the Inhibition Effect on Bacterial Cells by Use of Scanning Electron Microscopy

The antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of Ocimum basilicum L. were studied. These extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. The results indicated that the methanol extracts of O. basilucum exhibited the antimicrobial activity against tested microorganisms. While the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strains of Pseudomonas aeruginosa, Shigella sp., Listeria monocytogenes, Staphylococcus aureus and two different strains of Escherichia coli. The cells of microorganisms, which were treated and untreated with plant extracts, were observed by using the scanning electron microscope. It was observed that the treated cells were damaged.     

炒紫苏子醇提物对血小板聚集活性的影响

目的:探讨炒紫苏子醇提取物对腺苷二磷酸(ADP)、花生四烯酸(AA)和血小板活化因子(PAF)诱导血小板聚集功能的影响。方法:用诱导剂ADP(终浓度3μmol/L)、PAF(终浓度7.2 nmol/L)、AA(终浓度0.35 mmol/L)分别激发血小板聚集,观察炒紫苏子醇提取物对血小板聚集的抑制作用。结果:炒紫苏子醇提取物体外能抑制由ADP、PAF和AA激发的兔血小板聚集,并表现明显的剂量依赖关系。其中,对PAF诱发的血小板聚集作用有更强的抑制作用,80mg/L就表现出明显的抑制作用(P<0.05);而对于ADP和AA激发的兔血小板聚集,640 mg/L炒紫苏子醇提取物表现出明显的抑制作用。结论:炒紫苏子醇提取物具有明显的抗血小板聚集作用。     

两种仙人掌提取物抗肿瘤作用的研究

目的探讨仙人掌提取物对S180荷瘤小鼠体内的抗肿瘤作用。方法以小鼠移植性肉瘤S180为模型,观察仙人掌醇提取物和水提取物的抗肿瘤作用,并分别计算出抑瘤率和生命延长率。结果两种仙人掌提取物对S180小鼠的抑瘤率分别为72.30%和69.95%(与对照组相比较差异有显著性,P<0.01);两种仙人掌提取物也能延长荷艾氏腹水瘤(EAC)小鼠的存活期,生命延长率分别为57.14%和43.92%(与对照组相比较差异有显著性,P<0.01)。结论两种仙人掌提取物在动物体内有抗肿瘤作用,可作为一种有前途的抗肿瘤药物进行研究。