1.Expression, purification and characterization of a phyA(m)-phyCs fusion phytase.
Li-Kou ZOU ; Hong-Ning WANG ; Xin PAN ; Guo-Bao TIAN ; Zi-Wen XIE ; Qi WU ; Hui CHEN ; Tao XIE ; Zhi-Rong YANG
Journal of Zhejiang University. Science. B 2008;9(7):536-545
The phyA(m) gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichia pastoris in order to expand the pH profile of phytase and decrease the cost of production. The fusion phytase phyA(m)-phyCs gene was successfully overexpressed in P. pastoris as an active and extracellular phytase. The yield of total extracellular fusion phytase activity is (25.4+/-0.53) U/ml at the flask scale and (159.1+/-2.92) U/ml for high cell-density fermentation, respectively. Purified fusion phytase exhibits an optimal temperature at 55 degrees C and an optimal pH at 5.5~6.0 and its relative activity remains at a relatively high level of above 70% in the range of pH 2.0 to 7.0. About 51% to 63% of its original activity remains after incubation at 75 degrees C to 95 degrees C for 10 min. Due to heavy glycosylation, the expressed fusion phytase shows a broad and diffuse band in SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). After deglycosylation by endoglycosidase H (EndoH(f)), the enzyme has an apparent molecular size of 95 kDa. The characterization of the fusion phytase was compared with those of phyCs and phyA(m).
6-Phytase
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genetics
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isolation & purification
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metabolism
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Amino Acid Sequence
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Fermentation
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Genetic Vectors
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Molecular Sequence Data
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Pichia
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genetics
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Recombinant Fusion Proteins
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biosynthesis
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isolation & purification
2.Analysis of lymph node metastasis in the thoracic esophageal squamous cell carcinoma.
Zi-Jiang ZHU ; Yong-Fan ZHAO ; Yang HU ; Long-Qi CHEN ; Lun-Xu LIU ; Zhu WU ; Ying-Li KOU ; Yun WANG
Chinese Journal of Oncology 2008;30(2):138-140
OBJECTIVETo assess the metastatic frequency in different groups of lymph nodes and its influencing factors of the thoracic esophageal squamous cell carcinoma (ESCC) in order to determine the extent of lymphadenectomy during esophagectomy.
METHODSThe clinical data of 730 patients with ESCC who underwent esophagectomy and lymphadenectomy were analyzed retrospectively.
RESULTSOf 730 patients, 166 had metastasis to the para-esophageal lymph nodes (22.7%), 90 to the left gastric artery lymph nodes (12.3%), 67 to the lymph nodes around gastric cardia, and 15 to the subcrinal lymph nodes (2.1%). Univariate analysis showed that metastasis to the subcrinal lymph node was positively correlated with the length and differentiation of tumor (P < 0.05), but it was not correlated with any the above parameters when analyzed by multivariate analysis. The metastasis to the para-esophageal lymph node was positively correlated with the length, invasion depth and differentiation of tumor by univariate and multivariate analysis (P < 0.05). The metastasis to the lymph nodes around gastric cardia and metastasis to left gastric artery lymph nodes were positively correlated with the position and invasion depth of tumor by univariate and multivariate analysis (P < 0.05).
CONCLUSIONLymph nodes of the para-esophagus, gastric cardia and left gastric artery usually have high frequency to harber mestastasis, therefore, it was suggested that the lymph nodes in these groups should be dissected during esophagectormy with two-field lymphadenectomy for thoracic esophageal squamous cell carcinoma. Whereas for those patients with the lesion < 3 cm in length or with tumor invasion confined within the esophageal wall or with a lesion located at the upper or lower third of the thoracic esophagus, the subcrinal lymph nodes may not be necessarily dissected.
Adult ; Aged ; Carcinoma, Squamous Cell ; pathology ; surgery ; Cardia ; Esophageal Neoplasms ; pathology ; surgery ; Esophagectomy ; methods ; Esophagus ; Female ; Humans ; Lymph Node Excision ; methods ; Lymph Nodes ; pathology ; surgery ; Lymphatic Metastasis ; Male ; Middle Aged ; Multivariate Analysis ; Neoplasm Invasiveness ; Neoplasm Staging ; Retrospective Studies
3.A meta-analysis on overweight, obesity and the risk of breast cancer in Chinese female population.
Qi ZHANG ; Yun QIAN ; Zi-Yi JIN ; Mei-hua DONG ; Ren-qiang HAN ; Jin-yi ZHOU ; Jin-kou ZHAO ; Zuo-feng ZHANG ; Ming WU
Chinese Journal of Preventive Medicine 2013;47(4):358-362
OBJECTIVETo estimate the association between overweight, obesity and the risk of breast cancer in Chinese female population.
METHODSLiteratures published in China and abroad about overweight, obesity and breast cancer risk among Chinese females were searched. We used "breast cancer", "overweight", "obesity", "weight", "body mass index" and "risk factors" as keywords, to retrieve papers in Chinese literature databases including CNKI, Wanfang and Weipu database. The same strategy was used to retrieve English papers in English literature database including Embase database, PubMed, Science Direct, Elsevier and Cochrane database, supplemented by literature tracing method. Time range was from the founding of each database to April 2012. A total of 124 research papers were collected. Using Stata11.2 software, meta-analysis was conducted, combined odds ratio (OR) and 95% confidence interval (CI) were calculated to estimate the associations between overweight, obesity and the risk of breast cancer in Chinese female population.
RESULTSEighteen studies were included in meta-analysis, among them 12 studies were in Chinese and 6 were in English, with a number of 7217 cases and 81 605 controls. Results showed a 7.7% increased risk of breast cancer among overweight or obesity women (OR = 1.08, 95%CI: 1.04 - 1.12). Compared with normal BMI women, the OR (95%CI) of overweight or obesity women were 1.07 (1.03 - 1.11) and 1.56 (1.29 - 1.84) before and after the adjustment of menopausal status.
CONCLUSIONOverweight, obesity may be important risk factors of breast cancer in Chinese female population. The intervention and control activities may reduce the risk of breast cancer at population level.
Asian Continental Ancestry Group ; Breast Neoplasms ; epidemiology ; China ; epidemiology ; Female ; Humans ; Obesity ; epidemiology ; Overweight ; epidemiology ; Risk Factors