抗菌肽对种植体周围炎主要致病菌生长抑制作用的研究

目的研究抗菌肽KSL及其衍生物KSL—W对种植体周围炎主要致病菌的体外抑菌效果。方法应用二倍稀释法检测KSL和KSL—W对血链球菌、具梭核杆菌和牙龈卟啉单胞菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）;MTT法检测KSL和KSL—W对成骨样细胞MG-63的细胞毒性。结果KSL和KSL—W对具梭核杆菌的MIC和MBC分别为0．0156mg／mL和0．0313mg／mL,对牙龈卟啉单胞菌的MIC和MBC分别为0．125mg／mL和0．5mg／mL,在0．5mg／mL的浓度范围内对血链球菌没有抑制作用;KSL和KSL-W在0．5mg／mL的浓度范围内没有细胞毒性。结论KSL和KSL—W没有细胞毒性,对具梭核杆菌和牙龈卟啉单胞菌具有抑制作用。     

植物悬浮细胞的研究进展

综述了植物悬浮细胞培养的原理、培养类型、不同植物悬浮细胞培养基的配方和培养方法.同时阐述了悬浮细胞系在细胞生物学和分子生物学领域中的应用前景.     

Up-regulation of multiple serine proteinases during earthworm tail regeneration

Summary

Previous studies have shown that spatiotemporal regulation of extracellular matrix (ECM) by proteinases is implicated in the initial step of regeneration. In amphibian regeneration, the up-regulation of proteinases such as metalloproteinases (MMPs) and cathepsin D, and proteinase-related proteins such as proteinase tissue inhibitors and activators has been demonstrated. Since the earthworm could provide a unique and valuable model to investigate the mechanism of regeneration, we studied the developmental change in proteinase expression during earthworm tail regeneration. Zymographic analysis revealed that proteinase activities began to increase within 1 h after amputation and reached a maximum at 7 days post-amputation. This peak in activity was approximately 22-fold greater than the unamputated controls. Thereafter, the proteinase activities tended to decrease followed by another peak at 30 days before returning to control levels. At least four types of proteinase were distinguishable at 7 and 30 days post-amputation, with molecular weights of 25, 28, 38, and 44 kDa, respectively. All proteinase activities were strongly inhibited by addition of phenylmethylsulfonyl fluoride (PMSF) and aprotinin, specific inhibitors for serine proteinase. Pepstatin A, E-64, iodoacetamide and a metal ion-free medium were not effective inhibitors, indicating that proteinases expressed during earthworm tail regeneration would be serine proteinases. In addition, we were able to detect two types of plasminogen activator (PA) with molecular weights of 40 and 47 kDa, respectively. PA activities were predominantly expressed at 1, 5, and 25 days post-amputation, which preceded two peaks of serine proteinase activities appearing at approximately 7 and 30 days after amputation, respectively. This fact supports the view that serine proteinases expressed in respond to tail amputation may be plasmin-like proteinases activated by PA.     

Multimodal signals in male European treefrog (Hyla arborea) and the influence of population isolation on signal expression

In nocturnal treefrogs, mate choice implies the use of acoustic and visual signals. Multimodality is suspected to have evolved for either information redundancy or information complementariness. It is essential to explore multimodality in a natural context to understand the selection pressures operating on the signals. In the present study, we investigated calling and coloration in relation to male biometry and condition in four populations of European treefrog (Hyla arborea) varying in size and genetic isolation. We compared the signal intensity between core and satellite populations to estimate the impact of genetic diversity on male secondary sexual traits. The results obtained show important regional variations in both traits, likely as a result of local adaptations. Call and coloration are weakly correlated within an individual, implying that these traits likely convey different information about the signaller's identity or quality, thus supporting the hypothesis of complementariness of multiple messages. By contrast to the experimental evidence, we find that call and coloration are not related to male condition (as estimated by the residual of mass over size), suggesting that the condition‐dependence of these traits may be mediated by complex mechanisms not accurately reflected by the chosen estimator. Finally, male call and colour phenotypes present no robust pattern of variation with isolation status, probably because of variation in local selective pressures and in history of population dynamics. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 633–647.     

蟋蟀对召唤声识别的趋声性定位行为

为了探究蟋蟀种内个体间的声音通讯原理,本研究通过回放利用Cool-edit2000声音采集软件采集的双斑蟋Gryllus bimachlatus召唤声,分别对雌、雄蟋蟀识别召唤声的趋声性定位行为进行了观测研究。实验结果表明:雌、雄双斑蟋对回放的召唤声均有较强的识别反应,但雌蟋蟀的趋声定位性较强,能在较短的时间内积极寻找到声源,路径成"s"型;雄蟋蟀反应相对较弱,路径较长,找到声源时间比雌蟋蟀长。本研究结果揭示召唤声在蟋蟀种内通讯中不仅对个体间的联系有作用,对异性求偶也有重要作用。     

大鼠脑缺血再灌注后血清中血管内皮生长因子与神经元凋亡的研究

目的：通过检测SD大鼠脑缺血再灌注模型血清中血管内皮生长因子（VEGF）与神经元凋亡动态表迭变化的关系,以探讨两者之间的相关性。方法：将40只大鼠随机分为8组：对照组、假手术组和脑缺血30min再灌注12h组、1d组、3d组、5d组、7d组、及14d组,每组5只。采用ELISA双抗夹心法检测大鼠血清中血管内皮生长因子、原位细胞凋亡TUNEL法检测脑组织中的凋亡神经细胞数。结果：再灌注12h、1d、3d、5d、7d及14d大鼠血清VEGF表达和凋亡神经元百分比的变化均为负相关性（均为P〈0．05）。结论：在脑缺血再灌注大鼠模型中,缺血诱导使VEGF的表达发生变化,VEGF通过直接或间接的途径抑制神经元凋亡。