s〕 Objective:To investigate the influence of repeated firings on the color of porcelain fused to metal crown(PFM) . Methods: 5 PFM samples were prepared and fired for 9 times.The color of the samples was measured following firing with CIE1976 L*a*b* color system . The color difference ?E ab *,hue angle h ab * and chroma C ab * were calculated according to the following calculations:?E ab * ={(?L*) 2 +(?a*) 2 +(?b*) 2} 1/2 , C ab * ={(a*) 2+(b*) 2} 1/2 , h ab *=tg 1 b*/ a*, L* presented brightness. Results: After repeated firing, L* value of PFM , C ab * and L* value of dentin layer and h ab * value of opaque layer increased. Conclusion: The color of PFM after repeated firing may become brighter. The color change is resulted from the increase of L* and C ab * of dentin layer.

Objective: To study the influence of repeated firings on the PFM bond strength. Methods: 25 specimens of PFM in the diameter of 13.0 mm and thickness of (1.0?0.02) mm were prepared and fired at 920 ℃ for 1, 3, 5, 7 or 9 times(5 samples for each time). The remained porcelain rate(RPR) was measured by Mackert method and used to evaluate the bond strength.Results: After 3 firings, the RPR of PFM decreased obviously, and additional firings had no obvious effect on the RPR. Conclusion: 3 times firing or more may decrease the bond strength of PFM.

BACKGROUND: Bone marrow stromal stem cells (BMSCs) are characterized by rapid amplification and wide differentiation.Thus, to establish in vitro BMSC induction models contributes to the study of tissue engineering.OBJECTIVE: To investigate the possibility of inducing the differentiation of rat BMSCs into cardiomyocytes by 5-azacitidine in vitro.OESING, TIME AND SETTING: The cytological in vitro study was performed at the Central Laboratory of First Affiliated Hospital of Liaoning Medical University from June 2005 to June 2008.MATERIALS: A total of 20 Sprague Dawley rats were supplied by the Experimental Animal Center, Liaoning Medical University.5-azacitidine (Sigma, USA) was used.MHEHODS: Following anesthesia, the rats were used to isolate the femur and tibia. BMSCs were isolated and cultured by the whole bone marrow method + adherent method. When 90% BMSCs were confluence, BMSCs were passaged. BMSCs at the third passage were incubated in a 24-well plate at 2×10~4/well, with 5,10, 15, 20 μmol/L 5-azacitidine. Simultaneously, a blank control group (without inductor) was set. Following 24 hours of induction, BMSCs were incubated in normal medium for 3 weeks.MAIN OUTCOME MEASURES: The following parameters were measured: cell appearance and growth curve, morphological changes following induction, and expression of connexin-43 and a-striated muscle actin.RESULTS: Cultured BMSCs were spindle-shape, with some cell confluence. P3 cells following incubation entered static phase at 1 and 2 days, and entered logarithmic phase at 3 days, reached a peak at 9 days, and then entered platform stage. Cell number became decreased at 12 days. Following induction of 5 μmol/L 5-azacitidine, no significant difference was found in BMSCs.Following induction of 10 μmol/L 5-azacitidine, BMSCs became long and big, extended towards a direction, with the property of myotube formation cells. Following induction of 15 umol/L 5-azacitidine, a few cells survived surrounding the 24-well plate.Following induction of 20 μmol/L 5-azacitidine, cells died. Following induction of 10 μmol/L 5-azacitidine for 3 weeks, expression of connexin-43 and a-striated muscle actin was determined in BMSCs. However, a negative expression was detected in the blank control group.CONCLUSION: BMSCs cannot differentiate into cardiomyocytes by itself. Following in vitro induction, BMSCs can differentiate into cardiomyocytes. Low-dose 5-azacitidine concentration cannot induce the differentiation, but high-dose 5-azacitidine concentration will induce death in a large number of cells. Thus, 10 μmol/L is an optimal concentration.

OBJECTIVE:To establish an HPLC method for the determination of lipoic acid in lipoic acid sustained-release tablets.METHODS:HPLC was conducted on a Hypersil ODS with acetonitrile-0.05 mol?mL-1 potassium dihydrogen phosphate(45∶55,adjust pH to 2.0)as mobile phase at a flow rate of 1.0 mL?min-1.The injection volume was 10 ?L;the detection wavelength was set at 219 nm and the column temperature was 25 ℃.RESULTS:The linear range of lipoic acid was 9.99～399.70 ?g?mL-1(r=0.999)with an average recovery rate of 99.17%(RSD=0.40%);the intra-day and inter-day RSD were all less than 2.6%.CONCLUSION:The method is simple and accurate,and suitable for the determination of the content of lipoic acid in lipoic acid sustained-release tablets.

Objective To investigate the outcomes of unselected peripheral T cell lymphoma (PTCL) patients treated with in-tensive first-line chemotherapy with high-dose therapy followed by autologous stem cell transplantation (ASCT).Methods Here a nonrandom study was reported for 23 PTCL patients treated with first-line intensive chemotherapy followed by autologous stem cell trans-plantation and 23 PTCL patients treated with conventional chemotherapy during January in 2000 to 2011 .All patients had received E-CHOP for 6~8 cycles, and autologous stem cell transplantation group was administrated with intensive chemotherapy followed by ASCT after complete remission or partial remission .Results There was no statistically significant difference in short-term therapeutic effect between two groups( P >0.05), but the 5-year overall survival(OS) of autologous stem cell transplantation group( 58%) was higher than conventional chemotherapy group , as well as 5-year disease-free survival time (DFS) (45%in autologous stem cell transplanta-tion group, and 21%in conventional chemotherapy group ) with both statistical significance ( P <0.05).Only the incidence of Ⅳ° myelosuppression in autologous stem cell transplantation group ( 100%) was higher than that in conventional chemotherapy group ( 13%) ( P <0.01 ) .Conclusions First-line intensive chemotherapy followed by autologous stem cell transplantation for peripheral T cell lymphoma was quietly safe utility , it was better than conventional chemotherapy which would be considered as first -line method.

Objective To construct bispecific antibody BsAb1/17 against both IL-1β and IL-17A,express and purify the biologically active BsAbl/17 protein in prokaryotic system for further studies and applications. Methods VH1VL17-CL and VL1VH17-CH1 gene segments were constructed by overlap-PCR.Restriction enzyme sites Nco Ⅰ and BamH Ⅰ were designed at the 5'and 3' end primers respectively. The products of overlap-PCR were ligated to the Nco Ⅰ/BamH Ⅰ -prepared pET-27b vector. The recombinant plasmids pET-27b-VH1 VL17-CL(petA) and pET-27b-VL1 VH17-CH1 ( petB ) were transformed into E. coliRosetta separately. The expressing products were analyzed by SDS-PAGE and Western blot. Neutralization activity of the bispecific antibody for blocking the induction of IL-18 expression by IL-1β in human T cells was determined by real-time PCR. Neutralization activity of the bispecific antibody for blocking the induction of IL-6 expression by IL-17A in HeLa cells was determined by ELISA assay. Results The structure of the plasmids pET-27b-VH1 VL17-CL(petA) and pET-27b-VL1 VH17-CH1 (petB)was confirmed by DNA sequencing. After induction, the fusion proteins were expressed mainly as inclusion bodies. The purity of the both proteins exceeded 90%. SDS-PAGE analysis suggests the relative molecular mass of both products expressed by petA and petB were approximately 38× 103, which is in accordance with the theoretical value. The results of Western blot and ELISA test demonstrated that BsAb1/17 molecule had binding ability to both IL-1β and IL-17A. The BsAb1/17 could block IL-1β to stimulate human T cell to express IL-18 and block IL-17A to stimulate HeLa cell to express IL-6. Conclusion We successfully constructed a novel bispecific antibody BsAb1/17 against both IL-1 β and IL-17A, and expressed biologically active BsAb1/17 protein in prokaryotic system.

With the rapid development of industrial biotechnology, breakthrough in enzymology and biocatalysis has been made in recent years, especially in areas of stability and activity of enzyme in nonaqueous media, screening, construction and modification of solvent-tolerant biocatalysts, as well as the development of green solvent with excellent biological and environmental compatibility. Recent trend and future focus include: in silico virtual screening and construction of solvent-tolerant biocatalysts based on bioinformatic technology, modification and construction of native solvent-tolerant biocatalysts, the development of environmental friendly green solvent such as ionic liquids.
Animals ; Biocatalysis ; Biotechnology ; trends ; Enzymes ; chemistry ; genetics ; Humans ; Solvents

OBJECTIVE: To evaluate the effect of aerobic exercise on genome expression in human skeletal muscle. METHODS: Six healthy sedentary elderly men aged (66+9) years were selected from military cadre retirement centers and after exercise. Testing indices included height, weight, vital capacity, step index and maximal oxygen uptake. Needle biopsies were obtained from the skeletal muscle before and after the last training. Total RNA extracted from the samples was hybridized to Affymetrix U 133A platform, the gene expression datum was analyzed.RESULTS: Aerobic exercise was shown to improve cardiorespiratory function and reduce body fat of elder subjects. It could alter the genome expression in human skeletal muscle, the number of genes that passed filtering criteria was 725. The most differently expressed genes (n=20) were investigated in this study, in which there were 3 upregulated and 17 downregulated. According to gene function annotations, the differential genes were classified into 8 categories which concerned cellular component and biological process, Kyoto Encyclopedia of Genes and Genomes (KEGG) searching showed 4 genes' metabolism pathway. CONCLUSION: Systematic aerobic exercise upregulates expression of enzyme genes concerning tricarboxylic acid cycle, and downregulates expression of genes conceming muscle protein synthesis and sphingolipid. It is suggested that aerobic exercise is good to protect human nerves' integrity, exerts positive action on anti-aging and accelerate the aerobic metabolism of lipid materials in vivo.

AIM:To construct myocardium-specific nucleolin ( Ncl) transgenic mice and to provide an animal model for the studies of the myocardial protection of nucleolin .METHODS:To create nucleolin transgenic mice , a myo-cardium-specific expression plasmid of nucleolin ( Alpha-MyHC clone 26-Ncl) was constructed .The gene type of transgenic mice was identified by PCR and the nucleolin protein level was tested by Western blotting .The myocardium morphology , heart weight index (HWI) and left ventricular pressure maximum rise rate were observed in nucleolin transgenic (TG) mice and wild-type ( WT) mice.RESULTS:We gained 4 transgenic mice (51, 52, 56 and 86 lines, only 52 line and 86 line were eugonic) by PCR.Western blotting analysis showed the expression of nucleolin up-regulated specifically in the myocardium .However , the myocardium morphology , HWI and left ventricular pressure maximum rise rate in the nucleolin transgenic mice were similar to those in the wild-type mice.CONCLUSION:We constructed myocardium-specific nucleo-lin transgenic mice successfully .

Aim To explore inhibitory effects and mechanism of engineering endostatin on growth and metastasis of melanoma cells in mice. Methods Melanoma cells(2× 106/mouse)were inoculated sabcutaneously to C57BL/6 mice. After tumorigenesis,endostatin(8mg/kg.d)was administrated to tumor-bearing mice,once a day ,twenty-one in all.Dietetic state and weight change of the tumor-bearing mice were observed and tumorous sige was measured during administration of endostatin. On 26thday,the tumor-bearing mice were sacrificed,subcutaneously tumorous weight was weighed and brain,lung ,liver,spleen and kidney were excised and sections were made to supply the pathological examination. Results Area under curve in the endostatin-treated group was obviously less than that in tamor control group(P∨ 0.01). Pathological study revealed that lavge areal necrosis arose in tumor and newborn cappillaries around the tumor disapeared. Conclusion Endostatin possosses strongly inhibitory effects on growth and metastasis of mouse melanoma and formation of newborn capillaries around tumor.