Progress in biosynthesis of santalene and santalol / 生物工程学报

Santalene and santalol are the main components of valuable perfume sandalwood essential oil, and have good antibacterial, anti-oxidation and anti-tumor activities. Commercial sandalwood essential oil is mainly extracted from sandalwood tree that grows slowly and is difficult to cultivate. In addition, the extraction recovery of sandalwood essential oil from sandalwood tree is too low to meet the market demand. These factors make sandalwood essential oil expensive. An option is to use genetic engineering and molecular biological methods to heterologously express related synthase of santalene and santalol in microbial host. In this paper, the biosynthesis progress of santalene and santalol synthase, as well as the optimization of mevalonate metabolic pathways in the hosts are summarized. Furthermore, the strategies of applying protein engineering technology to carry out orthomutation of santalene synthase were also discussed, to provide reference for the optimal biosynthesis of santalene and santalol.

Upregulated heme oxygenase-1 expression of mouse mesenchymal stem cells resists to chemotherapy-induced bone marrow suppression / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Bone marrow hematopoietic function suppression is one of the most common side effects of chemotherapy. After chemotherapy, the bone marrow structure gets destroyed and the cells died, which might cause the hematopoietic function suppression. Heme oxygenase-1 (HO-1) is a key enzyme of antioxidative metabolism that associates with cell proliferation and resistance to apoptosis. The aim of this study was to restore or resist the bone marrow from the damage of chemotherapy by the HO-1 expression of mouse mesenchymal stem cells (mMSCs) homing to the mice which had the chemotherapy-induced bone marrow suppression.</p><p><b>METHODS</b>One hundred and sixty female Balb/c mice (6-8-weeks old) were randomly divided into four groups. Each group was performed in 40 mice. The control group was intraperitoneally injected for 5 days and tail intravenously injected on the 6th day with normal saline. The chemotherapy-induced bone marrow suppression was established by intraperitoneally injecting cyclophosphamide (CTX) into the mice which performed as the chemotherapy group. The mMSCs were tail intravenously injected into 40 chemotherapically damaged mice which served as the mMSCs group. The difference between the HO-1 group and the mMSCs group was the injected cells. The HO-1 group was tail intravenously injected into the mMSCs that highly expressed HO-1 which was stimulated by hemin. The expression of HO-1 was analyzed by Western blotting and RT-PCR. Cell proliferation was measured using the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Histopathologic examinations were performed 1 week after injection.</p><p><b>RESULTS</b>Compared with the control group, the expression levels of HO-1 mRNA and protein were significantly higher in the HO-1 group (all P < 0.05), even obviously than the mMSCs group. CTX treatment induced apoptosis and inhibited proliferation. After injected, the white blood cell (WBC), red blood cell (RBC) and platelet (PLT) declined fast and down to the bottom at the 7th day. The bone marrow structure was destroyed incomplete. In vitro, the survival rate of cells in chemotherapy group was less than 50% after 24 hours. In contrast, mMSCs could do a favor to the cellular cleavage and proliferation. They slowed down the cell mortality and more than 50% cells survived after 24 hours. The effects of blocking apoptosis and bone marrow recovery could be more effective in the HO-1 group. In the HO-1 group, it had observed that the bone marrow structure became complete and the hemogram closed to normal at 7th day.</p><p><b>CONCLUSIONS</b>HO-1 played an important role in promoting the recovery of CTX-induced hematopoietic damage. We suggest that HO-1 is able to restore the functions of chemotherapy-induced hematopoietic damage.</p>

Research on the development strategy of children's hospital under the new situation / 中华医学教育探索杂志

Facing the new problems under the background of new era,with the establishment of the market economy of our country and the improvment of the medical health system,how to solve medical health problems,how to strengthen the modernization management of state-owned hospital,and how to improve their comprehensive strength become the focus of the health research.With the internal and external environment analysis and the strategic management theory,this paper puts forward the development strategy and the support system of the children's hospital of Chongqing Medical University.