OBC/SF复合软骨支架的制备及性能

采用TEMPO/Na Br/Na Cl O体系对细菌纤维素(BC)进行氧化改性,然后以氧化细菌纤维素(OBC)、丝蛋白(SF)作为基础材料,负载骨形态发生蛋白(BMP-2),经电凝胶技术制备负载BMP-2的OBC/SF复合水凝胶。通过扫描电镜(SEM)、孔隙率、力学性能、体外降解率测试对所制备的复合水凝胶进行表征,将软骨细胞种植于负载BMP-2的OBC/SF复合水凝胶支架上进行体外联合培养,观察软骨细胞在支架中的增殖情况。结果表明:该OBC/SF复合水凝胶是一种具有细腻、疏松的双网络孔隙结构,良好的降解性能、优异的力学性能,适合细胞增殖的骨组织工程支架材料;BMP-2的加入有诱导软骨细胞分化,维持软骨细胞特点的作用。

6 Kinds of Isozymes after Long-term Subculture of Emmenopterys henryi Oliv.

[Objective] The aim was to study the changes of zymography in 6 kinds of isozymes after long-term subculture of Emmenopterys henryi Oliv.. [Method] Non-denaturing polyacrylamide gel electrophoresis was used to analyze isozyme patterns such as esterase (EST),acid phosphatase (ACP),ATP enzyme (ATPase),amylase (AMY),superoxide dismutase (SOD) and peroxidase (POD) in long-term subculture callus of Emmenopterys henryi Oliv. [Result] The research showed that there were differences among the 6 kinds of isozymes in embryogenic callus and non-embryogenic callus of Emmenopterys henryi Oliv.,and both levels could be taken as the basis for identification,the EST,ACP,and POD of non-embryogenic callus were significantly higher than embryogenic callus. The browning of non-embryogenic callus was non-level in the AMY,SOD and POD isozymes when was compared with normal non-embryogenic callus,while the EST,ACP and ATPase isozymes decreased; When the browning of embryogenic callus was contrasted with normal embryogenic callus,EST isozyme increased and the other 5 kinds of enzymes decreased. [Conclusion] The study provided theoretical basis for research morphological difference and browning of long-term tissue culture of Emmenopterys henryi Oliv..

Isozymes Analysis of the Golden Cuttlefish Sepia esculenta (Cephalopoda: Sepiidae)

Thirty nine isozymes in four tissues (mantle muscle, buccal bulb muscle, eye and liver) of Sepia esculenta were screened for enzymatic analysis using starch gel electrophoretic technique. Eighteen enzymes (G3PDH, LDH, MDH, MEP, IDHP, PGDH, GRS, NP, AAT, CK, AK, EST, ALP, ACP, FBP, MPI, GPI and PGM) show strong activities and good convergence in zymogram. They are proved to be suitable genetic markers in Sepia esculenta. Among the tissues used, mantle muscle is the best for electrophoretic analysis of isozymes. Eye and liver are fairly good for some special enzymes, such as LDH, EST, MPI, etc. Twenty six loci are detected. The proportion of polymorphic loci is 0.115 in the Qingdao sample and 0.153 in the Rizhao sample ( P < 0.99 ). The mean values of the observed and expected heterozygosity per locus of Qingdao sample are 0.016 and 0.017 , while those of the Rizhao sample are 0.023 and 0.025 respectively.

Effects of low dose pre-irradiation on the toxicity of cyclophosphamide

Objective:The aim of the study was to investigate the effects as well as the possible mechanisms of low dose γ-ray pre-irradiation on hepatic damage,DNA damage of peripheral lymphocytes and genetic material damage caused by high dosage of cyclophosphamide(CTX).Methods:Kunming strain male mice were randomly divided into five groups:control group,sham-irradiated group,low dose irradiation group(LDR group),cyclophosphamide chemotherapy group(CTX group) and low dose irradiation combined with chemotherapy group(LDR + CTX group).Having being raised for one week,all the mice were implanted subcutaneously with S180 cells in the left inguen(control group excluded).On days 8 and 11,mice of LDR and LDR + CTX groups were given 75 mGy whole-body γ-irradiation,30 h later mice of CTX and LDR + CTX groups were injected i.p.3.0 mg cyclophosphamide.All the mice were sacrificed on day 13.DNA damage of the peripheral lymphocytes was analyzed using single cell gel electrophoresis(SCGE);ALT activity,total protein(TP) and albumin(ALB) of the plasma were analyzed using automatic biochemistry analyzer;MDA content,SOD and GSH-PX activity of the hepatic homogenate were analyzed using chromometry;genetic material damage was analyzed using micronucleus frequency(MNF) of polychromatoerythrocytes(PCE) in bone marrow.Results:1.Differences of MDA contents,SOD and GSH-PX activity of hepatic homogenate between 5 groups had notable statistical significance(P < 0.01);in control group MDA content was the lowest,SOD and GSH-PX activity were the highest,while in CTX group MDA content was the highest,SOD and GSH-PX activity were the lowest;compared with CTX group MDA content decreased significantly(P < 0.01) and SOD and GSH-PX activity increased significantly(P < 0.05) in LDR + CTX group.2.Differences of ALT activity of plasma between 5 groups had no statistical significance(F = 1.262,P > 0.05).Differences of TP and ALB of plasma between 5 groups had statistical significance(F = 12.879 and 6.336 respectively,P < 0.01);TP and ALB in control group were higher than those of other groups and compared with sham-irradiated group,TP and ALB in LDR group elevated significantly(P < 0.05).3.Differences of DNA damage of peripheral lymphocytes had notable statistical significance(F = 6.383,P < 0.01);DNA damage in control group was the lightest,while DNA damage in CTX group was the severest;compared with CTX group,DNA damage in LDR + CTX group was much lighter(P < 0.05).4.MNF of PCE between 5 groups had remarkable significance(F = 179.652,P < 0.01);compared with control group and sham-irradiated group,MNF in CTX group increased significantly(P < 0.01);compared with CTX group,MNF in LDR + CTX group had a tendency of decline,which had no statistical significance(P > 0.05).Conclusion:1.CTX can damage the hepatic tissue through oxidative stress;75 mGy γ-irradiation before CTX chemotherapy can induce activities of anti-oxidative enzymes,promote elimination of free radicals,so as to alleviate the damaging effects of oxidative stress to hepatic tissue caused by high-dose chemotherapy.2.A 75 mGy γ-irradiation before CTX chemotherapy has no obvious effect on ALT activity of plasma,but may have protective effect on the protein synthesis function of liver.3.High-dose CTX chemotherapy can cause DNA damage of peripheral lymphocytes;75 mGy γ-irradiation before chemotherapy may have certain protective effect on DNA damage.4.CTX has potent mutagenic effect,can cause significant increase of MNF of PCE;75 mGy γ-ray pre-irradiation did not show obvious protection against genetic toxicity of high-dose CTX chemotherapy.

Secondary Structure and Neurotrophic Effect of a 33.1 kDa Specific Protein (SSP-33.1) in Spinal Sensory Ganglia

Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by two dimensional electrophoresis. One specific protein in sensory neurons was isolated and purified by DEAE Sephacel ion exchange chromatography and high performance liquid chromatography. A primary analysis of its secondary structure by circular dichroism, and its neurotrophic effects were investigated using the model of dorsal root ganglia(DRG) cultured in vitro . Results The molecular weight and isoelectric point of the protein were 33 1 kDa and 5 52, respectively. Its circular dichroism showed that there were 20 8% α helix, 54 8% β sheet, 7 3% turn, and 17 1% random coil in its secondary structure. Biological experiments showed that the protein could promote the neurite outgrowth of DRG. Conclusion A specific protein in spinal sensory tissue with molecular weight of 33 1 kDa has been purified. There is mainly β sheet in the secondary structure of the protein. And the protein has neurotrophic effects in the model of DRG.

Development of a novel modified EGSB reactor for municipal sewage treatment at ambient temperatures

A novel modified expanded granular sludge bed(EGSBm) reactor was developed for anaerobic treatment of municipal sewage with mixed liquid recirculation instead of effluent recirculation commonly adopted by a conventional EGSB(EGSBc) reactor.Performances of these two reactors were compared in treating municipal sewage at ambient temperatures ranging from 8 to 26 ℃.At an upflow liquid velocity(Vup) of 10.3 m/h,the mean concentrations of filtrated COD(CODfilt) and COD of the EGSBm effluent were determined to be 59.4 and 95.9 mg/L,respectively,which were significantly lower than those of the EGSBc effluent operated under identical experimental conditions.When the organic loading rate was suddenly increased from 1.2 to 7.2 kg COD/(m3·d),the EGSBm regained the removal efficiency of previous operation phase in 10 d.Hydrodynamic characteristics of the reactors were compared using the residence time distribution(RTD) model.It was found that the treatment efficiency of EGSBm kept increasing as the Vup increased.The polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis(PCR-DGGE) technique was used to analyze the microbial diversity in EGSBm.Fingerprinting pattern indicated that some species in the inoculating sludge were still reserved in the granular sludge of EGSBm,moreover,several new species occurred.