PTSD促进大鼠中缝背核细胞色素c表达

目的研究创伤后应激障碍(PTSD)大鼠中缝背核神经元细胞色素C(Cyt-c)的表达变化。方法应用无连续单一刺激(SPS)方法建立PTSD大鼠模型,随机分为SPS刺激后1d、4d、7d和对照组,应用酶组织化学法和RT-PCR方法观察中缝背核神经元Cyt-c的表达变化。结果光镜酶细胞化学法和RT-PCR法显示中缝背核神经元Cyt-c染色阳性细胞于SPS刺激后1d明显高于对照组,4d逐渐增高,并于7d达到高峰。电镜下显示Cyt-c阳性反应产物主要分布在中缝背核神经元线粒体膜,SPS刺激后可见Cyt-c释放到胞浆中。结论 SPS刺激引起Cyt-c在PTSD大鼠中缝背核神经元呈过表达。     

Glycated albumin and diabetes mellitus

Background

Diabetes is a growing worldwide problem that is strongly associated with atherosclerosis. Screening and intervention for diabetes in the earliest stages are advocated for the prevention of diabetic complications and cardiovascular disease.

Scope of review

This review gives a background of and discusses the potential clinical utility of glycated albumin (GA) in diabetes.

Major conclusions

GA is a ketoamine formed via a non-enzymatic glycation reaction of serum albumin and it reflects mean glycemia over two to three weeks. GA can be used for patients with anemia or hemoglobinopathies for whom the clinically measured hemoglobin A1c level may be inaccurate. Because both serum and plasma samples can be used, GA can be analyzed from the same samples as common biological markers. GA is a useful marker for the screening of diabetes in a medical evaluation. It can be also used to determine the effectiveness of treatment before initiating or changing medications for diabetic patients. GA is potentially an atherogenic protein in the development of diabetic atherosclerosis.

General significance

GA measurement is useful as part of a routine examination to screen for both diabetes and atherosclerosis. This article is part of a Special Issue entitled Serum Albumin.     

绿色荧光报告基因在细胞免疫检测中的应用

将丙肝病毒C E1区基因插入绿色荧光报告基因pEGFP-N1中,构建真核表达重组质粒pEGFP-N1-HCV/C E1。转染小鼠骨髓瘤细胞SP2/0,在荧光显微镜下观察绿色荧光融合蛋白的表达情况。结果在细胞浆中出现了绿色荧光,表明目的基因得到表达,再通过G418筛选后大量培养用作细胞毒实验的靶细胞,结果表明以EGFP报告基因作筛选标记制备的靶细胞完全可以满足细胞毒实验要求。     

Effects of newly synthesised platinum(ii) complexes on mitochondrial functions

Protease deficient recA431 mutants of Escherichia coli are defective in their capacity for induction of SOS responses and were intermediate in their sensitivities to ultraviolet light (UV) and cis-platinum(II)diamminodichloride (cis-PDD). Survival after treatment determined as colony forming ability was greater in rec⁺ strains and decreased in recA13 mutants which are defective in both recA proteolytic and recombination capabilites. In contrast, recA431 mutants were as sensitive to N-methyl-N′-nitro-N-nitrosoguanidine (NTG) as the recA13 cells. When cells carried either the pKM101 or N3 plasmid, survival after treatment with the three mutagens was increased. Presence of these plasmids in cells also resulted in hypermutagenicity as indicated by reversion of the argE3 mutation using a modified Ames test. Mutagenesis by NTG and cis-PDD was increased, as was survival of cells treated with UV light, cis-PDD and NTG in both recA⁺ and recA431 (protease deficient) strains. No plasmid mediated enhancement of mutagenesis or cell survival was observed in recA13 mutants. Thus, the ability of the plasmids to enhance cell survival and mutagenesis was dependent on recombination proficiency of the recA gene product and not its regulatory proteolytic activity. Unlike UV or NTG, presence of one of these plasmids was needed to detect reversion of the argE3 mutation by cis-PDD.     

应用差异PCR技术研究MTX耐药细胞的遗传学改变

基因扩增是介导细胞产生耐药性的一种普遍性机制。为探讨MTX耐药的小鼠细胞中与耐药机制形成有关的分子遗传学背景,应用差异PCR技术,检测了MTX耐药细胞中DHFR基因的扩增和过表达,并对c-myc及p53基因状态与dhfr扩增之间的相关性进行了探讨。结果表明：dhfr的扩增和过表达直接介导细胞耐药。未检测到c-myc的扩增和p53拷贝数的变化;也未检测到c-myc mRNA水平的改变,但p53基因的mRNA水平明显升高,显示p53可正常表达。这些结果表明dhfr的扩增与这两个侯选基因的状态无关,提示该耐药细胞中可能存在其他的分子遗传学改变允许基因大量扩增。     

E2F6在物理性低氧及化学性低氧诱导的凋亡中的表达特征

心肌细胞凋亡性死亡是低氧发生时的重要病理学特征,但低氧诱导的心肌细胞凋亡的调控机制尚未完全阐明.E2F6是E2F转录因子家族成员之一,我们新近的研究证实其具有抑制DNA损伤诱导的细胞凋亡作用.但是,E2F6是否参与了低氧诱导的心肌细胞凋亡的调控尚不清楚.在本研究中,我们初步探讨了E2F6在物理性低氧及化学性低氧模拟物诱导大鼠心肌细胞系H9c2细胞凋亡中的表达特征.结果表明:物理性低氧、化学性低氧模拟物去铁胺(desferrioxamine,DFO)和氯化钻(cobalt chloride,CoCl2)均能有效诱导H9c2细胞发生凋亡.在物理性低氧及CoCl2,诱导的H9c2细胞凋亡中,内源性E2F6 mRNA表达明显下调,但蛋白表达没有明显变化.而在DFO诱导的凋亡中,内源性E2F6 mRNA及蛋白表达均发生明显下调.这些结果提示,E2F6可能参与调控DFO模拟低氧诱导的H9c2细胞凋亡,而对物理性低氧及CoCl2,模拟低氧诱导的细胞凋亡敏感性较低.此外,DFO模拟低氧诱导的细胞凋亡机制可能与物理性低氧及CoCl2.模拟低氧诱导的细胞凋亡机制不同.     

异烟肼影响重组耻垢分支杆菌Rv1776c基因表达的实验研究

目的 研究经典抗结核药物异烟肼对重组耻垢分支杆菌生长增殖及其Rv1776c基因表达的影响。方法 将重组菌MS-Rv1776c接种于LB培养基培养作为对照组,实验组给予异烟肼药物处理,不同时间点取菌液测量A600值,根据所测A值绘制增殖曲线;提取菌液DNA以RT-PCR方法检测异烟肼对Rv1776c基因表达的影响;免疫印迹法SDS-PAGE及Western blot检测异烟肼对Rv1776c蛋白表达的影响。结果 异烟肼对两组重组耻垢分枝杆菌增殖无显著影响（P>0.05）;异烟肼可抑制Rv1776c基因的表达（P<0.05）;SDS-PAGE及Western blot检测发现异烟肼可显著降低ERv1776c蛋白的表达（P<0.05）。结论 异烟肼对重组耻垢分支杆菌的增殖无影响,但可抑制结核分枝杆菌Rv1776c基因及其表达的蛋白。该结果对研究结核菌从休眠菌到复苏初期及活跃期的药物预防提供了实验依据。     

Circular Thin-layer Chromatography of Oligosaccharides

The physicochemical properties and chemical constituents of the blue protein from rice bran were investigated. The blue protein was a copper-containing glycoprotein, the molecular weight of which was found to be 18,300 Daltons by the sedimentation equilibrium method assuming the partial specific volume 0.72 cm³ g^?1. The hexose and pentose contents were 5.49 and 4.01 g per 100 g protein respectively. The copper content was 0.38% which corresponded to 1.09 atoms per one molecule of the protein. The electron spin resonance spectrum showed that the copper was in a cupric state. The standard oxidation-reduction potential of the copper was found to be +275 mV at 20°C and at pH 7.39. The visible and near infrared absorption maxima were found at 450, 600 and 890 mμ, and the 450 mμ band was optically active in the optical rotatory dispersion exhibiting a large Cotton effect.