1.Preliminary Clinical Study of MRI in Primary Hepatic Cancer with Different Differentiation
Weizhuo HU ; Zhonghu LIU ; Hongjuan QIN ; Hui QI ; Lei ZHANG
Progress in Modern Biomedicine 2017;17(26):5074-5078
Objective:To study parameters of MRI image in different tissue differentiation,cell type of primary liver cancer.Methods:The pathological results and MRI data of regeneration nodules (27),hepatocellular carcinoma (HCC) (81 total;15,highly differentiated;40,moderately differentiated;26,low-grade differentiation),intrahepatic cholangiocarcinoma (ICC) (20) were retrospectively analyzed and compared To compare the difference of ADC values,strengthen degree among the regeneration nodules,HCC and ICC,and among HCC tissue differentiation.Results:Most cases of primary liver cancer can be accurately diagnosed by conventional MRI combined with LAVA.there are statistically significant differences of ADC values among regenerative nodules,HCC,ICC (P<0.01),and among highly,moderately,poorly differentiated HCC groups (P<0.01).But there is not actual clinical significance of the ADC values between moderately and poorly HCC.there is no statistically significant difference of the ADC values between highly differentiated HCC and ICC (P=0.27).Conclusion:Conventional MRI combining with DWI,LAVA can help distinguish the primary liver cancer differentiation degree and the cell type.
2.Immunological enhancement effects of IL-2 on the duodenum mucosa in Gush chicken
Shusong ZHANG ; Zhonghu LIU ; Xiangtao KANG ; Feng ZHAO ; Chuanbin XIAO
Chinese Journal of Veterinary Science 2009;29(7):909-913
To investigate the immunological enhancement effects of IL-2 with different doses in chicken Shigella vaccine on the duodenum mucosa in Gushi chicken,parental line Gushi chicken were grouped and inoculated with Shigella vaccines including different dose of IL-2.And then the distribution and change of SIgA positive cells and its secretion in the duodenum of the chicken were observed with the immunohistochemistry technology using the Qwin image analysis system.SIgA postive cells were distributed and located primarily in inhesion membrane and enteraden cavity of the duodenum mucosa,additive IL-2 in the Shigella vaccine could increase secretion of SlgA positive cells and strengthen the immunity of the birds,in some degree.The 50 μg IL-2 in the vaccine could display a optimal immunological enhancement effect.
3.Effect of N-terminal truncation of Bacillus acidopullulyticus pullulanase on enzyme properties and functions.
A'na CHEN ; Xiuxia LIU ; Xiaofeng DAI ; Jinling ZHAN ; Feng PENG ; Lu LI ; Fen WANG ; Song LI ; Yankun YANG ; Zhonghu BAI
Chinese Journal of Biotechnology 2016;32(3):355-364
We constructed different N-terminal truncated variants based on Bacillus acidopullulyticus pullulanase 3D structure (PDB code 2WAN), and studied the effects of truncated mutation on soluble expression, enzymatic properties, and application in saccharification. Upon expression, the variants of X45 domain deletion existed as inclusion bodies, whereas deletion of CBM41 domain had an effective effect on soluble expression level. The variants that lack of CBM41 (M1), lack of X25 (M3), and lack both of CBM41 and X25 (M5) had the same optimal pH (5.0) and optimal temperature (60 degrees C) with the wild-type pullulanase (WT). The K(m) of M1 and M5 were 1.42 mg/mL and 1.85 mg/mL, respectively, 2.4- and 3.1-fold higher than that of the WT. k(cat)/K(m) value of M5 was 40% lower than that of the WT. Substrate specificity results show that the enzymes exhibited greater activity with the low-molecular-weight dextrin than with high-molecular-weight soluble starch. When pullulanases were added to the saccharification reaction system, the dextrose equivalent of the WT, M1, M3, and M5 were 93.6%, 94.7%, 94.5%, and93.1%, respectively. These results indicate that the deletion of CBM41 domain and/or X25 domain did not affect the practical application in starch saccharification process. Furthermore, low-molecular-weight variants facilitate the heterologous expression. Truncated variants may be more suitable for industrial production than the WT.
Bacillus
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enzymology
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Glycoside Hydrolases
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metabolism
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Molecular Weight
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Protein Conformation
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Sequence Deletion
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Substrate Specificity
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Temperature
4.Hyperosmotic stress and perfusion culture strategies increase the yield of recombinant adenoviral vector produced by HEK 293 cells.
Zhuoxi ZHANG ; Zhonghu BAI ; Guangyin LIU ; Jianqi NIE ; Yankun YANG
Chinese Journal of Biotechnology 2023;39(8):3364-3378
With various diseases ravaging internationally, the demands for recombinant adenoviral vector (Adv) vaccines have increased dramatically. To meet the demand for Adv vaccine, development of a new cell culture process is an effective strategy. Applying hyperosmotic stress in cells before virus infection could increase the yield of Adv in batch culture mode. Emerging perfusion culture can significantly increase the yield of Adv as well. Therefore, combining the hyperosmotic stress process with perfusion culture is expected to improve the yield of Adv at high cell density. In this study, a shake flask combined with a semi-perfusion culture was used as a scaled-down model for bioreactor perfusion culture. Media with osmotic pressure ranging from 300 to 405 mOsm were used to study the effect of hyperosmotic stress on cell growth and Adv production. The results showed that using a perfusion culture process with a hyperosmotic pressure medium (370 mOsm) during the cell growth phase and an isosmotic pressure medium (300 mOsm) during the virus production phase effectively increased the yield of Adv. This might be due to the increased expression of HSP70 protein during the late phases of virus replication. The Adv titer in a bioreactor with such a process reached 3.2×1010 IFU/mL, three times higher than that of the traditional perfusion culture process. More importantly, this is the first time that a strategy of combining the hyperosmotic stress process with perfusion culture is applied to the production of Adv in HEK 293 cells. It also reveals the reason why the hyperosmotic stress process increased the yield of Adv, which may facilitate the process optimization of for producing other Adv in HEK 293 cells.
Humans
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HEK293 Cells
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Genetic Vectors/genetics*
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Batch Cell Culture Techniques
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Bioreactors
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Perfusion
5.Secretory production of xylanase in Corynebacterium glutamicum using its endogenous elements.
Wei ZHANG ; Xiuxia LIU ; Yankun YANG ; Zhonghu BAI
Chinese Journal of Biotechnology 2019;35(3):425-434
We constructed bicistronic expression system containing AH6 promoter, 5' UTR and its fore 38 bp sequence from Corynebacterium glutamicum, followed by a conserved Shine-Dalgarno (SD) sequence for xylanase expression. The two major secretory pathways signal peptide in C. glutamicum, Tat (CgR0949) and Sec (CspB) dependent signal peptide were added before xylanase for its secretion. Fed-batch cultivation was done in a 5 L jar for high-level xylanase secretion. The enzyme properties of the purified xylanase were then studied, including the effect of temperature and pH on its activity. The xylanase could be secreted into the culture supernatant when the Sec-dependent signal peptide CspB was used, but none was detected when CgR0949 was used. The secretory production level of xylanase in a flask was 486.2 U/mL and become 1 648.7 U/mL when in a 5 L jar, which was 3.4 fold as in the flask. The optimal pH and temperature of xylanase were pH 4.5 and 45 ℃, respectively. Its activity was 80% of initial activity after pretreatment at 4 ℃ for 24 h at pH 4-11, 95% after incubation below 50 ℃ for 15 min, and 20% when the temperature above 60 ℃. The xylanase could be efficiently secreted into the culture medium by C. glutamicum using its own genetic elements, and the secretion level could be improved through large-scale fed-batch cultivation. This bicistronic expression system can provide a useful tool for heterologous proteins secretion in C. glutamicum. In addition, the catalyze activity of xylanase could be further improved by enzyme properties study.
Corynebacterium glutamicum
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Promoter Regions, Genetic
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Protein Sorting Signals
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Protein Transport