Relationship between Expression of Cellular Receptor-27.8kDa and Lymphocystis Disease Virus (LCDV) Infection

The 27.8kDa membrane protein from flounder (Paralichthys olivaceus) gill (FG) cells was previously identified as a putative cellular receptor involved in lymphocystis disease virus (LCDV) infection. In this paper, the expression of receptor-27.8kDa (27.8R) and LCDV loads in FG cells and hirame natural embryo (HINAE) cells were investigated upon LCDV infection and anti-27.8R monoclonal antibody (MAb) treatment. The results showed the 27.8R was expressed and co-localized with LCDV in both FG and HINAE cell surface. After LCDV infection, the expression of 27.8R exhibited a dose-dependent up-regulation with the increasing of LCDV titers, and demonstrated a tendency to increase firstly and then decrease during a time course up to 9 days; LCDV copies showed a similar variation trend to the 27.8R expression, however, it reached the highest level later than did the 27.8R expression. Additionally, the 27.8R expression and LCDV copies in FG cells were higher than those in HINAE cells. In the presence of increasing concentration of the anti-27.8R MAbs, the up-regulation of 27.8R expression and the copy numbers of LCDV significantly declined post LCDV infection, and the cytopathic effect induced by LCDV in the two cell lines was accordingly reduced, indicating anti-27.8R MAbs pre-incubation could inhibit the up-regulation of 27.8R expression and LCDV infection. These results suggested that LCDV infection could induce up-regulation of 27.8R expression, which in turn increased susceptibility and availability of FG and HINAE cells for LCDV entry, providing important new insights into the LCDV replication cycle and the interaction between this virus and the host cells.     

Immune response of Japanese flounder Paralichthys olivaceus to outer membrane protein of Edwardsiella tarda

The humoral and cellular immune responses of Japanese flounder, Paralichthys olivaceus, were investigated following intraperitioneal injection with outer membrane protein (OMP) of Edwardsiella tarda in Freund's incomplete adjuvant (FIA). The specific serum antibody titre against OMP of E. tarda were measured using ELISA for 14 weeks, and the total serum antibody concentrations were also determined according to the sandwich ELISA standard model constructed using purified IgM. Both of the specific and total antibodies had an increase and reached their peaks 4 weeks after immunization. Simultaneously, the percentages of sIg + lymphocytes in blood, spleen, pronephros and mesonephros were detected by flow cytometry. It was shown that the percentages of sIg + lymphocytes in all lymphoid organs reached their peak levels 4 weeks after immunization, and then decreased gradually. To investigate the protection against infection, three challenges were performed in the same way at day 14, 30 and 100 after immunization, fish challenged at day 30 showed a higher relative percentage survival (RPS) of 71 compared to the 14-day group (30) and 100-day group (53), which indicated a positive correlation between the survival and the levels of the antibody.     

北京夏植黄瓜内生真菌区系研究

为了解黄瓜植株内生真菌的区系组成及其变化,从而为进一步研究黄瓜内生真菌的生态和功能奠定基础,对采自北京延庆的不同品种和不同生育期的40株黄瓜进行了内生真菌的分离培养。经形态学鉴定和18S rDNA序列分析,分离到的1,024株内生真菌属于18属,其中Exserohilum和Neocosmospora尚未见内生真菌的报道。Alternaria、Aspergillus、Chaetomium、Cladosporium和Fusarium在各生育期和各器官普遍存在。其中,Alternaria在叶中的定殖率达47.0%,远高于在其他器官中的定殖率;Fusarium在根中的定殖率达32.5%,远高于在其他器官中的定殖率。多数真菌类群表现出不同程度的器官偏好性,有些真菌类群则只出现在特定器官中。叶和根的内生真菌类群数量和总定殖率均高于茎和果实。随着黄瓜的生长,各器官内生真菌的类群数在增加,部分真菌的定殖率也呈上升趋势,但Neocosmospora和Chaetomium在各器官中的定殖率则随植株生长呈下降趋势。     

留学生组织学全英文教学的探索与实践

我教研室已承担留学生组织学教学多年,在对留学生进行组织学全英文授课的教学实践中,为了提高教学质量,我们从课程安排、教材选用、教学方法、教学手段以及考试与成绩等方面进行了的探索和改革,并对留学生教学中遇到的语言交流问题进行分析,总结了提高外语水平的经验.本文就留学生组织学教学的探索与实践作了介绍,以便大家互相交流经验,共同提高.     

动脉瘤性蛛网膜下腔出血后致脑血管痉挛的发病机制分析

脑血管痉挛(cerebral vasospasm,CVS)是指脑动脉在一段时间内的异常收缩状态,目前已知CVS可继发于多种疾病当中,如蛛网膜下腔出血、高血压脑出血、急性颅脑损伤、脑手术后、脑部炎症等.脑血管痉挛是动脉瘤性蛛网膜下腔出血(aneurysmal subarachnoid hemorrhage,SAH)最常见的并发症.严重的脑血管痉挛可造成脑缺血和脑损害,是增加病人死亡和致残最重要的原因.近年来已受到国内外临床医生的更多重视,并且随着分子生物技术的发展,对SAH所致CVS的发病机制有了更多的认识和更新的进展.     

JNK、ERK信号通路在NaAsO2诱导骨髓间充质干细胞增殖中的作用

目的:研究c-ink氨基末端激酶(JNK)、细胞外信号调节激酶(ERK)在亚砷酸钠(NaAsO2)诱导骨髓间充质干细胞(BMSC)增殖中的作用.方法:体外培养骨髓间充质干细胞,四甲基偶氮唑盐比色法(MTT法)检测细胞增殖,Western-blot检测磷酸化JNK、ERK表达水平.结果:低浓度1、2μ mol/L NaAsO2对BMSC有明显的促进增殖作用;高浓度16、32μ mol/LNaAsO2则对细胞生长产生抑制作用,具有一定剂量-效应关系;2、4、8μ mol/LNaAsO2处理BMSC 24h后,JNK磷酸化表达水平明显增加,ERK磷酸化表达水平明显降低;JNK抑制剂SP600125可明显降低高浓度16、32μmol/LNaAsO2的生长抑制作用;ERK抑制剂PD98059可抑制低浓度1、2μ mol/LNaAsO2对BMSC的促增殖作用.结论:低浓度NaAsO2激活ERK信号通路,提高细胞增殖率,可被抑制剂PD98059阻断;高浓度NaAsO2激活JNK信号通路,提高细胞凋亡率,可被抑制剂SP600125阻断.NaAsO2致癌机制可能与JNK、ERK信号通路作用相关.     

血塞通体内中和内毒素作用的试验研究

目的:探讨血塞通体内中和内毒素的作用.方法:健康大耳白兔24只,随机分为正常对照组、内毒素组、血塞通干预组,每组8只.内毒素组经耳缘静脉静推LPS(1mg/kg),12h后再由耳缘静脉注射一次LPS(1mg/kg),复制SIRS/MODS动物模型;对照组耳缘静脉静推等量生理盐水;血塞通干预组于Oh,12h经耳缘静脉推注LPS(Img/kg)并于第一次注入内毒素后6h,12h,18h静推血塞通(50mg/kg).于24h时间点测定各组动物血清肿瘤坏死因子-α(TNF-α)、白细胞介素-(IL-1)、白细胞介素-8(IL-8)、血小板活化因子(PAF).光镜下观察各组动物脏器病理学变化.结果:血塞通干预组与内毒素组相比,IL-1、IL-8、PAF、TNF-α均较内毒素组有不同程度降低.血塞通干预组脏器损伤组织学改变较内毒素组明显减轻.结论:血塞通在体内能明显中和内毒素的作用,为防治SIRS/MODS提供了实验依据.     

附子连作障碍效应初步研究

通过大田试验,调查了连作附子的生长发育、产量及病虫害的变化,分析附子的连作障碍原因;并通过实验室常规分析,测定连作土壤的理化性状,探讨附子连作障碍的形成机理。结果显示：随着连作年限的增加,连作附子株高、茎粗、母根直径、最大子根直径均出现了不同程度的下降,其中连作对附子株高和茎粗的影响极显著;连作使病、虫害逐年加重,产量显著下降;附子连作使土壤pH下降,有机质含量升高,全N、有效P、速效K过剩。结果表明,连作加重了附子根腐病的发生,影响了附子母根的正常发育,从而导致附子产量下降;连作导致土壤pH降低是影响附子正常生长的限制因子。因此通过采用科学的配方施肥措施,调节土壤pH值,改善土壤环境,是缓解附子连作障碍的重要途径。     

新疆沙冬青叶片氨基酸和蛋白质的测试与分离以及抗冻蛋白的鉴定结果分析

提取并纯化了新疆沙冬青(Ammopiptanthus nanus)叶片总蛋白,得到了适合新疆沙冬青叶片总蛋白提取的最佳缓冲体系;用DEAE52-C分离了各蛋白质组分,并用SDS-PAG测定了纯度和分子量(14~90 kD之间);氨基酸组成分析显示了新疆沙冬青属内种遗传的一致性。对抗冻活性分析讨论证实了与蒙古沙冬青同属的新疆沙冬青中也含有抗冻蛋白(AFPs)。     

地统计学方法在长白落叶松人工林凋落物现存量估测中的应用

采用地统计学的变异函数分析方法定量研究了15年生落叶松(Larix olgensis)人工纯林凋落物层重量的空间异质性特征,利用地统计学的克里格内插法结合定积分,对凋落物层的重量进行了估测.结果表明1)不同分解层次的凋落物重量的变异函数曲线理论模型均为球状模型,空间变异主要是由结构性因素引起,且空间自相关程度均属中等以上(空间结构比＞25%).2)非参数统计的成对样本符号检验结果表明,变异函数分析结果基础上的克里格内插法适用于凋落物重量的估计.利用此估计值,拟合其与位置坐标值之间的多元回归关系均为二元十次余弦级数多项式.利用此多项式,通过定积分的方法(积分区间为整块样地的大小),估计出15年生落叶松人工纯林中凋落物层的未分解、半分解、完全分解和腐殖质层的重量分别为4.7753、5.4129、8.0742、10.9269t hm-2.3)采用地统计学的克里格空间插值,结合多元回归和定积分的方法,可以实现落叶松人工林凋落物层重量的准确估计.