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As a novel targeting drug delivery system, acid-sensitive micelles have many advantages, such as increasing solubility of lipophilic drugs, acid-sensitive release, high drug loading, etc. They can load drugs though non-covalent encapsulation and covalent conjugation methods. In tumor tissues, drugs are released quickly from the depolymerized micelles with lipophilic copolymer protonation or lypohydrophilic copolymer hydrolysis and covalent conjugated drugs are released when the acid-sensitive covalent linkage breaks. This review mainly advances acid-sensitive micelles for the tumor targeting drug delivery systems from drug-loaded methods and release mechanisms.

Objective: To investigate the effect of Cedemex on cAMP and cGMP contents in different brain regions in morphine withdrawal rats precipitated by naloxone., Method: A physical morphine dependent model of rats was established by subcutaneous injection of morphine in gradually increasing dosage within 7 days. cAMP and cGMP contents of VTA, cortex and hippocampus of the rat brains were determined by radioimmunoassay., Result: The morphine withdrawal symptoms of rats were relieved significantly by ig Cedemex. Compared with the controls, cAMP content in the region of VTA, cortex and hippocampus of the morphine dependent rats were significantly higher (P < 0.05), while cGMP contents in those regions were significantly lower (P < 0.05). cAMP contents in the area of VTA, cortex and hippocampus of the morphine dependent rats were significantly reduced, while cGMP contents were significantly increased by ig Cedemex., Conclusion: Cedemex may significantly attenuate the morphine withdrawal symptoms in rats. The mechanism of this effect may be related to adjusting the contents of cAMP and cGMP in some brain regions.

Objective: To study the possibility and mechanism by which the human umbilical blood mesenchymal stem cells (MSCs) are induced to differentiate into neuron in vitro by baicalin, a kind of flavonoid isolated from an important medicinal plant Scutellariae Radix., Methods: Human cord blood was obtained via sterile procedure with 20 U/ml of preservative-free heparin. MSCs were isolated by the two-step assay of gelatin sedimentation plus Ficoll centrifugation separation, purified and amplified in the liquid culture medium. According to the kind of antioxidants, the experiment was conducted in five groups: induction group, control group I, control group II, control group III and control group IV. Five subgroups of MSCs amplificated ex vivo for 2 weeks in each group were induced by the media containing baicalin (BC, 200 - 400 micromol/L) or baicalin-free for seven days. The media consisted of induction medium (DMEM plus 200 - 400 micromol/L of baicalin) and post-induction medium (DMEM plus 200 - 400 micromol/L of baicalin, B27). The expression of neuronal or glia specific markers was evaluated by using indirect immunofluorescence cytochemistry staining. The percentage of differentiated cells and living cells was measured by Hoechest 33,258 staining assay., Results: After induction for 7 days, MSCs displayed neuronal morphologies, such as pyramidal cell bodies and processes formed extensive network. The undifferentiated cells did not exhibit a neuronal or glial phenotype, while the differentiating cells expressed NSE and MAP-2, the specific markers of neuron, but did not express GFAP, the specific marker of glia on the seventh day after induced by baicalin. The percentage of NSE and MAP-2 expressed on the seventh day after induced by baicalin was (76.3 +/- 9.2)% and (78.5 +/- 5.5)%, respectively, which was significantly higher compared with control group I, control group II and control group III (P < 0.01), respectively. In addition, the ratio of living cells after induced for seven days in the BC group was (85.3 +/- 4.8)%, which increased significantly compared with control group I, control group II and control group III (P < 0.01), respectively., Conclusions: Baicalin may induce the umbilical blood MSCs to neuron or neuron-alike cells in vitro in a moderate and stable manner. The mechanism of such an induction may be related with its controlling the activity of NF-kappaB which regulates the production of many kinds of cytokines, such as brain-derived neurotrophic factor (BDNF), etc.

Objective: To study the effect of three flavones-luteolin, apigenin and genistein on activity of recombinant human phosphoinositide 3-kinase (PI3-K) p110beta catalytic subunit., Methods: Recombinant human P13-K p110beta catalytic subunit was expressed by gene engineering. PI3-K activity was assayed by incubation recombinant PI3-K p110beta with phosphatidylinostiol-4,5-bisphosphate and [gamma-32P] ATP; the 32P-radiolabeled lipids were extracted with cholroform and methanol, and assessed by scintillation counter., Results: Luteolin and apigenin showed inhibition on the recombinant p110beta catalytic subunit with IC50 8. 65 micromol/L and 11.56 micromol/L, but genistein had no inhibition., Conclusion: Luteolin and apigenin are inhibitors of P13-K. The recombinant P13-K p1100 catalytic subunit may be used as a molecular target for simpler screening and development of more effective inhibitors of P13-K.

Objective: To observe the effect of taurine on hepatic stellate cell's apoptosis induced by carbon tetrachloride (CCl4) in rats and to study its protective mechanisms., Methods: CCl4-induced rat hepatic fibrosis was treated by taurine. Serum alanine aminotransferase (ALT), plasma protein, hyaluronic acid (HA), procollagen III (PC III), hepatic microsomal drug-metabolizing enzyme and anti-transforming growth factor beta1 (TGF-beta1) were determined. In addition, hepatic stellate cell's apoptosis and the pathological changes of liver tissue were observed under light microscope., Results: The activity of serum ALT and the levels of serum HA, PC III were markedly reduced by taurine treatment. The hepatic cytochrome P450 (Cyt. P450) and cytochrome b5 (Cytb5) contents were increased by the same treatment. In addition, taurine could significantly inhibit the expression of TGF-beta1, promote the hepatic stellate cell's apoptosis, and relieve hepatic fibrosis., Conclusion: Taurine fulfills a role in promoting hepatic stellate cell's apoptosis in the case of hepatic fibrosis, it mitigates the liver injury, decreases the expression of TGF-beta1, and relieves hepatic fibrosis.

Based on the principle of the pathway engineering, a novel pathway of producing glycerol was built in E. coli. The gpd1 gene encoding glycerol 3-phosphate dehydrogenase and the hor2 gene encoding glycerol 3-phosphatase were cloned from Saccharomyces cerevisiae, respectively. The two genes were inserted into expression vector pSE380 together. A recombinant plasmid pSE-gpd1-hor2 containing polycistron was constructed under the control of the strong trc promoter. Then it was transformed into E. coli BL21. The result showed the recombinant microorganism GxB-gh could convert glucose to glycerol directly. And the recombinant microorganism GxB-gh was incubated to produce glycerol from D-glucose in the fermentor. The maximal concentration of glycerol was 46.67g/L at 26h. Conversion rate of glucose was 42.87%. The study is about "green" producing glycerol by recombinant microorganism and is also useful for further working in recombining microorganism of producing 1,3-propanediol.

Background & Objective: Human tissue factor pathway inhibitor-2 (TFPI-2) is a newly discovered serine protease inhibitor, which inhibits plasmin, trypsin, matrix metalloproteinase (MMPs), but not urokinase, tissue-type plasminogen activators and thrombin. Earlier studies have shown that the production of TFPI-2 is downregulated during the progression of various cancers. The aim of this study was to elucidate the relationship between TFPI-2 expression and ovarian tumor migration and invasion., Methods: Human TFPI-2 expression vector pBos-Cite-neo/TFPI-2 was transfected into ovarian tumor cells line A2780. After the transfected cells were screened by G418, transfected and nontransfected cells were examined for TFPI-2 mRNA and protein by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. The number of transfected or nontransfected cells passing through membrane of Boyden chamber was counted as the basis assessing tumor cells migratory and invasive behaviors., Results: Expression of mRNA and protein of TFPI-2 were confirmed in transfected cells. In invasion assay, the number of TFPI-2-expressing cells to traverse a Matrigel-coated membrane was obviously decreased compared with that of nonexpressing cells (59.3+/-6.5 versus 109.7+/-5.5, P< 0.01); while in migration assay, no significant difference was observed between transfected and nontransfected cells (114.7+/-8.6 versus 127.3+/-7.1, P >0.05)., Conclusion: Expression of TFPI-2 may strongly inhibit the invasive ability of ovarian tumor cells in vitro, but has no effect on the migratory ability, which provides an experimental basis for treating human ovarian tumor with gene therapy.

A gas chromatographic method was developed to directly determine the enantiomers of acrylic ketone alcohol and acrylic ketone acetate. Two pairs of enantiomers were nearly baseline-separated by using Model HP-5890 Gas Chromatograph with flame ionization detector and WCOT CD-Chiral-DEX CB (30 m x 0.25 mm i.d.) column. The optimum conditions were the split ratio of 30:1 for the sample injected, the flow rates of 3.7 mL/min for the carrier gas (nitrogen), 60 mL/min for the hydrogen, and 250 mL/min for the oxygen, and temperatures of 148 degrees C for the column, 230 degrees C for the injector, and 230 degrees C for the detector. The linearity and reproducibility were satisfactory. The regression coefficients were over 0.9965. The RSDs obtained were less than 1.25%. The method was further used to trace the reactants and products, and to evaluate the enzyme catalyst activity and selectivity under different conditions. The results show that the method developed is very successful.