Production and characterization of a novel aminopeptidase A from Lactococcus lactis / 生物工程学报

Aminopeptidase A (Pep A) is a metal-dependent enzyme that specifically hydrolyze peptides with the N-terminal amino acids glutamic acid (Glu) and aspartic acid (Asp). A possible application of PepA is the hydrolysis of Glu/Asp-rich food proteins such as wheat gluten and casein, increasing the flavor and solubility of food protein. In the present study, the gene encoding a Pep A from Lactococcus lactis ssp. lactis IL1403 was synthesized and introduced into Pichia pastoris GS115 (His4). Lc-Pep A was successfully expressed and secreted to the culture medium, followed by identification and purification to homogeneity. Characteristics study demonstrated that Lc-Pep A could specifically hydrolyze the substrates Glu-pNA and Asp-pNA with similar catalytic activity, and this was further confirmed by the kinetics parameters measured. Additionally, Lc-Pep A showed a broad thermostability and pH stability with an optimum temperature of 60 ℃ and an optimum pH of 8.0. The enzyme activity of Lc-Pep A was activated by metal ions Co2+, Mn2+, and Zn2+ but was strongly inhibited by Ni2+and Cu2+. The routine proteinase inhibitor had no effect on the activity of Lc-Pep A. However, Lc-Pep A was strongly inhibited by the metallopeptidase inhibitor, EDTA, and disulfide bond-reducing agents. The study may facilitate production and application of Lc-Pep A.

Research on the effects of compound matrine injection combined with chemotherapy on elderly patients with colorectal cancer / 中国综合临床

Objective To study the effect of compound matrine injection combined with chemotherapy on the immune function and life quality of elderly patients with colorectal cancer. Methods Seventy patients with colorectal cancer treated in Shanghai Jiao Tong University Affiliated Sixth People′s Hospital South Campus from January 2010 to December 2013 were involved in this survey. They were divided into the control group and the observation group randomly,each group had 35 cases,the control group was treated with chemotherapy only, the observation group was treated with compound matrine injection combine with chemotherapy. The curative effect,life quality and immune function in the two groups were compared. Results The number of complete remission patients in the observation group was 8 cases ( 22. 86%) ,the number of partial remission cases was 16 cases ( 45. 71%) , the effective rate was 68. 57%, while the control group had 4 cases of complete remission (11. 43%),11 cases of partial remission (31. 43%),the effective rate was 42. 86% (Z=-2. 259,P=0. 024) . In the observation group,life quality was significantly improved in 10 cases (28. 57%),improved in 19 cases ( 54. 29%) ,the effective rate was 82. 86%,while in the control group,life quality was significantly improved in 4 cases ( 11. 43%) ,and improved in 10 cases ( 28. 57%) ,the effective rate was only 40%. The improvement rate of the two groups was statistically significant ( Z=-3. 497,P=0. 000) . Before treatment,the immune function indexes of patients in the two groups were close ( P>0. 05) ,after treatment,the immune function in both groups were significantly improved,CD3+,CD4+,CD4+/CD8+ levels of patients in the observation group were higher than those in the control group,while the CD8+ level in the observation group was lower than that of the control group ( t=-3. 968,P=0. 000;t=-5. 351,P=0. 000;t=-5. 474,P=0. 000;t=6. 407,P=0. 000) . The follow?up time of the two groups was 36 months. After 36 months,the survival rates of the observation group and the control group were 85. 7% (30/35) and 80. 0% (28/35) respectively,and the difference was not statistically significant (χ2=0. 402,P=0. 526) . Conclusion Compound matrine injection combined with chemotherapy can significantly improve the clinical efficacy of elderly patients with colorectal cancer,improve the immune function and quality of life,it is worthy of clinical application.

Clinical significance of differential Drosha expression between endometrial cancer tissue and other tissues / 天津医药

Objective To detect the different expressions of Drosha between endometrial cancer (EC) tissue and other tissues and to explore correlation between Drosha mRNA transcription level and protein expression level with clinicopatho?logical characteristics of EC. Methods The mRNA transcription and protein expression levels of Drosha were examinaned by q-PCR and Western blot respectively in normal endometrial tissues (25 cases), atypical hyperplasia of endometrial tis?sues (20 cases) and endometrial cancer tissues (40 cases). Correlations between Drosha mRNA transcription and protein ex?pression with clinicopathological characteristics of EC were analyzed. Results The levels of Drosha mRNA and protein lev?els in EC were obviously lower than those in endometrial atypical hyperplasia and normal endometrium (P0.05). The protein expression levels of Drosha were consistent with transcription of mRNA transcription levels. Drosha mRNA expression does not differ significantly with differentiation, histological type, myometrial invasion, lymphatic metasta?sis and FIGO stages of EC (P>0.05). Conclusion The expression levels of Drosha in EC tissues were down-regulated, therefore the reduction of Drosha may contributed to tumorigenesis of EC.

Expression and significance of spleen tyrosine kinase in endometrial cancer / 实用医学杂志

Objective To investigate the expression of spleen tyrosine kinase (Syk) in endometrial cancer ( EC ) and its relationship with the clinic and pathological factors , as well as the diagnostic value for EC . Methods Through real-time PCR and immunohistochemistry, the expression level of Sky mRNA and protein in normal endometrial tissues, atypical hyperplasia of endometrial tissues and endometrial cancer tissues were examined. Results The expression of Syk in EC were lower than that in endometrial atypical hyperplasia and normal endometrium (P < 0.05). The expression of Syk was related to histological grade, invasive depth, lymphatic metastasis and clinical stages (P<0.05). Conclusion Syk contributes to tumorigenesis and metastasis of EC. The detection of Syk can provide evidence to evaluate the malignancy grade of EC.

Correlation between CXCR4,VEGF and the blood metastasis of osteosarcoma / 中国癌症杂志

Background and purpose:The chemokine,CXCL12 and its receptor,CXCR4,have recently been shown to play an important role in the metastasis of several kinds of carcinoma. It also has been demonstrated that VEGF regulates both the expression of CXCR4 and invasiveness in cancer cell. Our aim was to study the expression of CXCR4,VEGF in osteosarcoma and the correlation between these two factors and distant metastasis. Methods: The immunohistochemical staining SP method was used to detect the expression of CXCR4 and VEGF in 56 cases of osteosarcoma. We analyzed the correlation between the expression of CXCR4 and VEGF,and the correlation between the expression of CXCR4,VEGF and clinical stage,the level of ALP. The patients were followed up for 2 years. Results:There was signifi cant correlation between the expression of CXCR4 and VEGF in 56 cases(r=5.678,P=0.02). Univariate analysis showed a signifi cant correlation between the expression of CXCR4,VEGF and clinical tumor stage(P=0.026),and no correlation between the expression of these two factors and age,sex and serum ALP level. 31 cases had metastasis in two years in a total of 56 follow-up cases,and the expression of CXCR4 and VEGF was associate with metastasis(P=0.018 and P=0.022,respectively). Conclusion:VEGF can upregulate tumor angiogenesis and promote tumor metastasis to specific organ by increasing expression of CXCR4.The increasing expression of CXCR4 and VEGF is useful to predict metastasis and prognosis of osteosarcoma.