Effects of Hedan tablet on cytokins and oxidative stress factors in APOE-/-mouse / 天津医药

Objective To observe the effects of Hedan tablet on cytokines and oxidation factors in APOE-/-mouse, and to explore its effect on atherosclerosis and to explore its behind mechanism. Methods APOE-/-mice (n=50) were randomly divided into control group, model group, low dose Hedan tablet treatment group, high dose Hedan tablet treatment group and simvastatin treatment group. Mice in control group were given normal feed while mice in other groups were fed with high cho?lesterol diet. Hedan or Simvastatin was administrated intra-gastrically while normal saline was given to model group in the same route. After 12 weeks, mice were sacrificed to observe the mRNA level of tumor necrosis factor-α(TNF-αmRNA) in aorta by RT-PCR. Mean while, serum levels of interleukin-1 (IL-1), interleukin-10 (IL-10), malonaldehyde (MDA) and su?peroxide dismutase (SOD) were determined in different groups. Results Compared with control group, TNF-αmRNA tran?scription level as well as serum levels of IL-1 and MDA significantly increase while serum levels of IL-10 and SOD de?creased remarkably in model group, (P<0.01). Compared with model group, mRNA levels of TNF-αas well as serum levels of IL-1 and MDA were significantly decreased while serum levels of IL-10, SOD were greatly increased in low dose and high dose Hedan tablet treatment groups as well as in simvastatin treatment group (P<0.01). Conclusion Hedan tablet inhibit the formation of atherosclerosis through its anti-oxidation role and anti-inflammation role.

Characterization of The Essential Gene Components for Conjugal Transfer of Streptomyces lividans Linear Plasmid SLP2 / 生物化学与生物物理进展

Commonly, the interbacterial transfer of circular plasmids is initiated by nicking at an internal sequence, oriT, followed by transferring one strand as single-stranded DNA through a type Ⅳ secretion channel on cell membrane. In contrast, Streptomyces conjugative linear plasmids, containing a free 3'-end but a protein-capped 5'-end, can potentially undergo cell-to-cell transfer by transfer of non-nicked DNA. It was reported that circular derivatives of the Streptomyces lividans linear plasmid SLP2, as well as the parental linear plasmid itself can transfer efficiently. And the genetic requirements for such transfer was described. Efficient transfer of plasmid requires six co-transcribed SLP2 genes, encoding a Tra-like DNA translocase, cell wall hydrolase, two cell membrane proteins that interact with an ATP binding protein, and a protein of unknown function. Reduced transfer efficiency of plasmid from SalⅠ R-/M-to Sal Ⅰ R/M hosts argues that transfer of both the circular and linear forms of the plasmid involves double-stranded DNA. These results suggest that conjugal transfer occurs by a similar mechanism for SLP2-derived linear and circular plasmids, and cellular membrane/wall functions in the transfer process.