Immobilizing engineered Escherichia coli cells into zeolitic imidazolate framework 8 for efficient biosynthesis of Ala-Gln / 生物工程学报

The α-amino acid ester acyltransferase (SAET) from Sphingobacterium siyangensis is one of the enzymes with the highest catalytic ability for the biosynthesis of l-alanyl-l-glutamine (Ala-Gln) with unprotected l-alanine methylester and l-glutamine. To improve the catalytic performance of SAET, a one-step method was used to rapidly prepare the immobilized cells (SAET@ZIF-8) in the aqueous system. The engineered Escherichia coli (E. coli) expressing SAET was encapsulated into the imidazole framework structure of metal organic zeolite (ZIF-8). Subsequently, the obtained SAET@ZIF-8 was characterized, and the catalytic activity, reusability and storage stability were also investigated. Results showed that the morphology of the prepared SAET@ZIF-8 nanoparticles was basically the same as that of the standard ZIF-8 materials reported in literature, and the introduction of cells did not significantly change the morphology of ZIF-8. After repeated use for 7 times, SAET@ZIF-8 could still retain 67% of the initial catalytic activity. Maintained at room temperature for 4 days, 50% of the original catalytic activity of SAET@ZIF-8 could be retained, indicating that SAET@ZIF-8 has good stability for reuse and storage. When used in the biosynthesis of Ala-Gln, the final concentration of Ala-Gln reached 62.83 mmol/L (13.65 g/L) after 30 min, the yield reached 0.455 g/(L·min), and the conversion rate relative to glutamine was 62.83%. All these results suggested that the preparation of SAET@ZIF-8 is an efficient strategy for the biosynthesis of Ala-Gln.

Research advances in pancreatic exocrine insufficiency secondary to pancreatic cancer / 临床肝胆病杂志

At present, there is still a lack of comprehensive diagnosis and treatment criteria for pancreatic exocrine insufficiency around the world. Pancreatic surgeons often ignore or misjudge pancreatic exocrine insufficiency secondary to pancreatic cancer, and as a result, pancreatic exocrine insufficiency is not adequately treated, which greatly affects the quality of life of patients with pancreatic cancer. This article summarizes the latest research advances in the pathogenesis, typical symptoms, and diagnostic methods of pancreatic exocrine insufficiency, as well as pancreatic enzyme replacement therapy in different stages of pancreatic cancer. It is pointed out that pancreatic enzyme replacement therapy can significantly improve the quality of life of patients with different stages of pancreatic cancer.

Role of leukemia inhibitory factor in pancreatic ductal adenocarcinoma / 临床肝胆病杂志

Pancreatic ductal adenocarcinoma is a highly invasive malignant tumor of the digestive system with an extremely poor prognosis. Leukemia inhibitory factor is an important member of the interleukin-6 family and can regulate multiple physiological processes such as cell differentiation, growth, and renewing. This article reviews the mechanism of action of leukemia inhibitory factor in pancreatic ductal adenocarcinoma and the research advances in leukocyte inhibitory factor-targeted therapy based on literature evidence, and the analysis shows that leukemia inhibitory factor plays an important role in the progression, immune escape, and chemotherapy resistance of pancreatic ductal adenocarcinoma and may gradually become a potential biomarker and therapeutic target for pancreatic ductal adenocarcinoma.

The clinical significance of sCD40L and Lp-PLA2 in the assessment of coronary artery severity and risk classification in patients with non-ST-segment elevation acute coronary syndrome / 西安交通大学学报(医学版)

Objective To investigate the clinical significance of soluble CD40 ligand (sCD40L ) and lipoprotein associated phospholipase A2 (Lp-PLA2 ) in the assessment of coronary artery severity and risk classification in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS).Methods Of the 9 6 patients with coronary heart disease diagnosed by coronary angiography,2 8 patients had stable angina pectoris (SAP),38 patients unstable angina pectoris (UAP)and 30 patients acute non-ST-segment elevation myocardial infarction (NSTEMI).Another 30 patients with non-coronary heart disease (NC)served as controls.The sCD40L and Lp-PLA2 levels were determined by enzyme-linked immune sorbent assay (ELISA)method.The Gensini score was used to assess the severity of coronary artery and analyze the correlation with sCD40L and Lp-PLA2.The correlation of sCD40L and Lp-PLA2 with GRACE risk score was analyzed too.Results ① sCD40L was significantly higher in NSTEMI and UAP groups than in SAP and NC groups (P0 .0 5 )or SAP and NC groups (P>0 .0 5 ).Lp-PLA2 was significantly higher in NSTEMI group than in UAP,SAP and NC groups (P<0.05).Lp-PLA2 was significantly higher in UAP group than in SAP and NC groups (P<0.05).② We found that sCD40L had obvious correlation with Lp-PLA2 (r=0.284, P<0.01),Gensini score (r=0.213,P<0.05),and GRACE (r=0.224,P<0.05).Lp-PLA2 was significantly correlated with Gensini score (r=0.270,P<0.05),and GRACE (r=0.323,P<0.01).③ Multivariate logistic regression analysis showed that Lp-PLA2 was independently associated with NSTE-ACS (P<0.05).Conclusion The sCD40L and Lp-PLA2 which were significantly elevated in NSTE-ACS are correlated with the severity of coronary artery disease.The two indexes indicate the instability of atherosclerotic plaque;thus they can be used as predictors of risk assessment in coronary heart disease.

Correlation of glycated hemoglobin,fibrinogen and cystatin C with the severity of coronary artery lesions in non-diabetic patients / 西安交通大学学报(医学版)

Objective To investigate the relationship of glycated hemoglobin (HbA1c),fibrinogen (Fbg)and cystatin C (Cys C)with the severity of coronary artery lesions in non-diabetic patients.Methods We enrolled 358 patients who received coronary angiography (CAG)in this study.They were divided into coronary artery disease (CAD)group and non-CAD group according to CAG results.Moreover,according to different clinical types of CAD,all the CAD patients were further classified into stable angina pectoris (SAP)group and acute coronary syndrome (ACS)group.We calculated Gensini score and divided CAD group into A,B and C subgroups by Gensini score.HbA1 c,Fbg,Cys C and other clinical data were measured and compared between groups,and the correlation analysis was used to find the relationship of HbA1c,Fbg and Cys C with Gensini score.Results The levels of HbA1 c,Fbg and Cys C were significantly higher in groups A,B and C than in non-CAD group.When Gensini score increased,the three indexes were increased too (P<0.05).The levels of HbA1c,Fbg and Cys C were significantly higher in ACS group than in SAP and non-CAD group (P<0.05).After adjustment for the influencing factors, HbA1 c was still associated with Fbg (P<0 .0 5 ).The levels of HbA1 c and Fbg were closely related to Gensini score (P<0.05).Conclusion In non-diabetes patients,HbA1c and Fbg are significantly related to the severity of coronary artery stenosis,and Cys C may not be an independent risk factor of coronary artery stenosis.

Expression and clinical significance of serum angiopoietin-2 in patients with chronic heart failure / 西安交通大学学报(医学版)

Objective To investigate the expression of serum angiopoietin-2 (Ang-2 ) and its clinical significance in patients with chronic heart failure (CHF).Methods The levels of serum Ang-2,N-terminal pro-B-type natriuretic peptide (NT-proBNP)and left ventricular ejection fraction (LVEF)were detected in 1 1 3 patients with CHF,who were divided into four groups according to New York Heart Association (NYHA:class Ⅰ,n=3 2;Ⅱ,n=30;Ⅲ,n=26;Ⅳ,n=25).Another 20 healthy volunteers for physical check-up were chosen as the control group.Results With the change of cardiac function (from Ⅰ to Ⅳ),the levels of plasma Ang-2 and NT-proBNP were increased significantly (P<0.05 ).The level of serum Ang-2 was positively correlated with NT-proBNP (r=0.774,P<0.001),but negatively correlated with left ventricular ejection fraction (r=-0.725,P<0.001).Conclusion The level of serum Ang-2 has a significant correlation with the severity of heart failure.Ang-2 is expected to be used to predict and evaluate the severity of CHF.

Relationship of CD31+/CD42b- and CD144+ endothelial micropaticles with intima-media thickness of carotid artery / 西安交通大学学报(医学版)

Objective To detect the levels of CD31+/CD42b- and CD144+ endothelial microparticles (EMPs)in plasma,and analyze the relationship with carotid intima-media thickness (CIMT)and the risk factors of atherosclerosis.Methods Totally 122 outpatients and inpatients in our hospital were selected,and carotid artery ultrasound examination was performed.The results were divided into a thickening group (62 cases)and a control group (60 cases).Flow cytometry was used to detect the levels of CD31+/CD42b- and CD144+ EMPs in the blood to analyze the relationship between the level of endothelial cells and CIMT,and to investigate the relationship between the level of plasma EMPs and the risk factors of atherosclerosis.Results Compared with the control group,the levels of EMPs of CD31+/CD42b- and CD144+ were significantly higher.In the correlation analysis, plasma CD31+/CD42b- and CD144+EMPs levels were positively correlated with CIMT;in multi-factor Logistic regression analysis,CD31+/CD42b- EMPs levels were correlated positively with age,TC and Cys C;plasma CD144+ EMPs levels were correlated with UA and BMI.Conclusion The levels of CD31+/CD42b-,CD144+EMPs in plasma were correlated with CIMT,guiding early prevention of cardiovascular diseases.