植物非共生血红蛋白的研究进展

植物非共生血红蛋白（nsHb）基因在植物界广泛存在。许多生物和非生物胁迫可以诱导nsHb的表达。nsHb在植物的生长发育和逆境胁迫中具有重要功能,其作用机制与NO的代谢密切相关。文章综述了非共生血红蛋白的表达特性、生物学功能及其作用机制等方面的研究进展。     

海马脑片缺氧损伤电位机制的研究

本实验在海马脑片采用微电极记录技术,观察了缺氧损伤电位（ＨＩＰ）的电生理特性,并研究了其产生机制。实验结果表明：①ＨＩＰ是突触在缺氧过程中功能暂时恢复的反应;②随着缺氧程度的加重,ＨＩＰ出现时间前移,持续时间缩短;③ＨＩＰ的出现表明突触功能的丧失发生在突触膜损伤之前,其消失代表突触传递不可逆性损伤的发生,即突触膜损伤的开始;④大剂量腺苷不能阻止ＨＩＰ的产生,表明ＨＩＰ的出现不是由于腺苷浓度的降低。     

Sensitive profiling of chemically diverse bioactive lipids

Here, we present an improved method for sensitive profiling of lipids in a single high-performance liquid chromatography-electrospray ionization-quadrupole time of flight mass spectrometry experiment. The approach consists of i) sensitive isocratic elution, which takes advantage of C18 column material that is resistant to increased pH values induced by piperidine, ii) chemometric alignment of mass spectra followed by differential analysis of ion intensities, and iii) semiquantitative analysis of extracted ion chromatograms of interest. A key advantage of this method is its wide applicability to extracts that harbor lipids of considerable chemical complexity. The method allows qualitative and semiquantitative analysis of fatty acyls, glycerophospholipids (such as glycerophosphatidylinositols, glycerophosphatidylserines, and glycerophosphatidylcholines in brain extracts), phosphatidylinositol mannosides, acylated glycerophospholipids, sphingolipids (including ceramides and gangliosides in brain extracts), and, for the first time with ESI, prenols and mycolic acids (MAs). MAs are targets in antimycobacterial therapy, and they play an important immunomodulatory role during host-pathogen interactions. We compared high-resolution mass spectra of MAs derived from Mycobacterium bovis Bacille Camette-Guérin during entry into nonreplicative conditions induced by oxygen deprivation (hypoxic dormancy). Although the overall composition is not drastically altered, there are pronounced differences in individual MAs. alpha-MAs accumulate during entry into dormancy, whereas a subpopulation of keto-MAs is almost entirely eliminated. This effect is reversed upon resuscitation of dormant mycobacteria. These results provide detailed chemical information with relevance to drug development and immunobiology of mycobacteria.     

乏氧微环境、“瓦伯格”效应及上皮间质转化相关性

肿瘤细胞在氧气充足的情况下以糖酵解的方式供能,这一现象称为“瓦伯格”效应,被认为是肿瘤的第七大特征。上皮间质转化（epithelial mesenchymal transition,EMT）是一种重要的细胞过程,参与胚胎发育、伤口愈合及肿瘤的发生等过程中,被认为是恶性肿瘤的重要特征。近年研究表明,“瓦伯格”效应和上皮间质转化的发生均与肿瘤处于乏氧微环境密切相关。乏氧微环境除可直接诱导上皮间质转化发生外,还可诱导肿瘤细胞产生“瓦伯格”效应,进一步促进上皮间质转化的发生。本文就乏氧微环境、“瓦伯格”效应、以及上皮间质转化的相关性的研究进展做一综述,有助于揭示乏氧微环境、肿瘤能量代谢改变以及肿瘤迁移侵袭之间的因果关联。     

多巴胺对急性间歇性低氧诱导的大鼠颈动脉体低氧敏感性的影响

目的:观察急性间歇性低氧刺激后大鼠颈动脉体对低氧的敏感性以及多巴胺对颈动脉体低氧敏感性的影响。方法:将分离SD大鼠的颈动脉体-窦神经移入到孵育槽,然后把分离的窦神经吸入到记录的玻璃电极中行电信号记录。记录基线部分缓冲液充入气体为95%O2+5%CO2混合气,低氧应激给予5%O2+5%CO2+90%N2混合气,低氧刺激给予30 s,95%O2+5%CO2给予90 s,共10个循环,每组实验大鼠数量n大于等于5。结果:大鼠离体的颈动脉体,给予急性间歇性低氧应激,再给予低氧刺激,窦神经较之前低氧刺激放电活动增强。但加入多巴胺后,可以抑制窦神经对低氧的反应,急性间歇性低氧后,多巴胺对窦神经的低氧放电活动抑制作用加强。结论:大鼠颈动脉体给予急性间歇性低氧可增强窦神经对低氧的反应,多巴胺可抑制急性低氧诱导的颈动脉体对低氧敏感性的增强。     

脑心通对急性低压低氧小鼠空间记忆功能及脑水肿的影响

目的:探讨脑心通对急性低压低氧诱发的空间记忆功能损害及脑水肿的预防作用及机制。方法:144只小鼠随机分为6组:即常压常氧组、常压常氧给药组、模拟海拔4km组(4km组)、模拟海拔8km组(8km组)、模拟海拔4km给药组(4km给药组)、模拟海拔8km给药组(8km给药组)。比较各组实验前后及组间的Y型电迷宫测试成绩及脑组织水含量、伊文思兰(EB)含量。结果:各组实验前的Y型电迷宫训练成绩无显著差异,实验后常压常氧组、常压常氧给药组、4km组、4km给药组、8km组和8km给药组,Y型电迷宫测试成绩分别为90.00±6.32、93.33±5.16、56.67±8.16、86.67±8.16、45.00±10.49和85.00±5.48(P<0.01);常压常氧组、常压常氧给药组、4km组、4km给药组、8km组和8km给药组比较,脑组织水含量结果分别为77.79±0.27、77.66±0.23、78.42±0.18、77.81±0.18、79.04±0.33、77.94±0.42,EB含量结果分别为0.44±0.04、0.43±0.02、0.98±0.07、0.46±0.06、1.17±0.07、0.49±0...