Objective The growth inhibitory effects of GlcNH_2?HCl,GlcNH_2 and NAG on human hepatoma SMMC-7721 cells in vitro was investigated.The antitumor activity of GlcNH_2?HCl against Sarcoma_(180) in KM mice was also investigated.Methods The cell viability in vitro was examined with MTT assay.DNA isolation and cell-cycle analyses were also performed.GlcNH_2?HCl was ig administered to Sarcoma_(180) KM mice.The inhibition rates,spleen and thymus index were calculated.Results GlcNH_2?HCl and GlcNH_2 resulted in a concentration-dependent reduction in hepatoma cell growth.The inhibition rates against SMMC-7721 cell of GlcNH_2?HCl and GlcNH_2 at concentration of 500?g?mL~(-1) were(50.24)% and 52.19%.As to the concentration of 1000?g?mL~(1), the rates were(82.21%) and 83.20%.This effect was accompanied by a marked increase in the proportion of S phase cells.Compared with the control,there was no significant difference among various concentrations of NAG,GlcNH_(2)?HCl exhibited inhibitiory effect against Sarcoma_(180) in mice at the dosage of 125～500 mg?kg~(-1),and the inhibition rate was about 27.84%～34.02%.The optimal inhibitory effect was 250 mg?kg~(-1).GlcNH_2?HCl could enhance the weights of thymus and spleen.In addition,it could promote lymphocyte transformation.Conclusion It is therefore postulated that the antitumor effect of GlcNH_2?HCl is probably host-mediated and cytocidal.

Chitinase (EC3.2.1.14) catalyses the reaction of hydrolyzing the chitin into N acetylglucosamine (GlcNac) and (GlcNac) n.With the in deep study of chitinase,more and more biological function of chitinase appeared obviously.Now,we introduce the actualities of chitinase research,including substrate specificity,physiological function,antifungi function and transgenics, et al .

Objective To observe the effect of carboxymethyl chitosan calcium(CCC) on the concentration of lead,calcium,and liver antioxidative capacity in lead poisoned mice.Methods mice were randomly divided into 6 groups.Three test groups were treated with CCC at three doses.The lead poisoned mice model was established by giving water containing lead acetate,and then CCC was administered to mice once a day.After 30 days,the mice were killed and the content of lead in blood,liver,brain and femur were determined by atomic absorption spectrophotometer,and antioxidative capacity in liver was measured using assay kit.Results CCC could reduce the contents of lead in blood,brain,liver and femur significantly,decrease the level of maleicdialdehyde(MDA),increase activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and total antioxidative capacity(T-AOC) in liver markedly. Conclusion CCC can promote the excretion of lead,increase the content of calcium in femur and antioxidative capacity in lead poisened mice.

Objective A strain with high alginase activity was screened and isolated by decomposing sodium alginate from the decaying parts of brown alga Laminaria japonica and Undaria pinnatifida,in order to produce alginase.Methods The strain s4 with high alginase activity was chosen by filtration.The alginase producing media was optimized and the alginase was produced and its characterization was investigated.Results The optimum fermentation conditions for alginate lyase producing as follows: media AlgNa 1.2%,NH4Cl 0.9%,NaCl 1.5%,pH=7.5,and temperature 25℃.Conclusion The alginase produced by strain s4 showed high alginase activity and good stability.

Objective:To study the effects of glucosamine(GlcNH2) on immune function in mice.Method:The effects of GlcNH2 on murine proliferation of splenocytes were carried out in vitro.After feeding mice by GlcNH2,the phagocytotic functions of mononuclear macrophage,murine delayed type hypersensitivity(DTH) caused by sheep red blood cells(SRBC),the ability of antibody production(tested by HC50),and the index of immune organs(thymus and spleen) were deteimined in vivo.Results:GlcNH2 could promote the proliferation of splenocytes,phagocytotic functions of mononuclear macrophage,DTH,the ability of antibody production and the index of immune organs.Conclusion:Glucosamine can enhance immune function in mice such as cellular immunity,humoral immunity and non-specific immunity.

To determine the number average molecular mass of chitosan-oligosaccharide by u-sing the acetylacetone's method based on the color-producing reaction with amino terminal . Via the tests on the repetitiveness, accuracy and the stability, supposed this method was reliable. At the same time, the contrastive results of HPLC and the traditional K3Fe(CN)6 method indicate that the acetylacetone method was more suitable for the determination of chitosan-oligosaccharide molecular mass.

BACKGROUND: Carboxymethyl chitosan is a water-soluble derivate modified from chitosan, with various biological activities. It is a good ligand of metal ion and can integrate Ca~(2+) to prepare a novel biological material. OBJECTIVE: To explore a method for preparing carboxymethyl chitosan calcium (CCC) and analyze its properties and structure. METHODS: CCC was produced by carboxymethyl ohitosan reacting with solution of calcium chloride. The solubility, carboxymethylation degree, rotational viscosity, and calcium content of CCC were determined, and infrared and ultraviolet spectral analyses were performed.RESULTS AND CONCLUSION: The calcium content of CCC was approximately 15%. Compared with carboxymethyl chitosan, infrared spectrum and ultraviolet spectrum of CCC were changed. The prepared CCC is a new calcium compound through property and structural analysis.

The characters of the chemical structure of CM-chitosan were studied, by assay the content of the N, carboxylation, Primary amine and DEPT,13C-NMR of CM-chitosan.

A1 strain with fibrinolytic activity was isolated from sea water in Qingdao. After combination treatment with ultraviolet light and MNNG, a mutant C22 producing 2947.60 u?mg -1 protein of fibrinolytic enzyme in culture broth was obtained.Its enzyme activity was 4.23 fold of wild stain A1.The optimum medium for fermentation consisted of 2.5% soy bean cake meal, 0.1% yeast extract,0.2%NaCl,0.05%MgSO 4?7H 2O,0.001%FeSO 4?7H 2O.They were dissolved with 0.05mol?L -1 ,pH7.4 phosphoric buffer.The strain producing maximum fibrnolytic activity after growth at 25℃ for 40h on a rotary shaker.The initial optimum pH was 7.0~7.5.

The current problems with corneal transplant,including shortage of donors and immune rejection,could be effectively solved by constructing cornea in vitro with tissue engineering techniques,in which the selection of suitable scaffold materials is especially critical.Chitosan and its derivatives are natural biomaterials with excellent biocompatibility,biodegradability,mechanical property and plasticity,indicating wide application prospects in corneal tissue engineering.This article systematically reviews the research advances in chitosan and its derivatives in corneal tissue engineering,and the existing problems are also highlighted in order to provide theoretical basis for further clinical research.