Risk factors of poor renal prognosis in coronary artery bypass grafting surgery-associated acute kidney injury patients / 中华肾脏病杂志

Objective:To explore the risk factors of poor renal prognosis in patients with coronary artery bypass surgery (CABG)-associated acute kidney injury (AKI), and establish a preliminary clinical risk prediction model for chronic kidney disease (CKD) progression in CABG-associated AKI patients, and evaluate its predictive efficacy.Methods:It was a retrospective, observational cohort study. The study subjects were patients who underwent CABG at Central China Fuwai Hospital from January 1, 2018 to December 31, 2020, with a baseline estimated glomerular filtration rate (eGFR)>60 ml·min -1·(1.73 m 2) -1 and postoperative complication of AKI. The patients were followed up for 90 days after discharge from hospital. The endpoint event was defined as progression to CKD after 90 days of the occurrence of CABG-associated AKI. The patients were divided into CKD group and non-CKD group based on whether they experienced endpoint events. The baseline clinical data were compared between the two groups. The logistic regression model was used to analyze the risk factors of endpoint event. The receiver-operating characteristic curve was drawn to evaluate the performance of the clinical risk prediction model for predicting poor renal prognosis in CABG-associated AKI patients. Results:A total of 124 CABG-associated AKI patients were enrolled in the study, including 95 males and 29 females, aged (62.57±9.61) years old. Thirty-eight patients (30.8%) progressed to new-onset CKD 90 days after CABG-associated AKI. Compared with non-CKD group, CKD group had lower preoperative hemoglobin ( t=2.778, P=0.006) and baseline eGFR ( t=3.603, P<0.001), higher proportion of women ( χ2=10.714, P=0.001), and higher preoperative blood NT-proBNP ( Z=-2.150, P=0.030) and discharged serum creatinine ( Z=-5.290, P<0.001). The multivariate logistic regression analysis results revealed that female ( OR=5.179, 95% CI 1.535-17.477, P=0.008), high preoperative blood NT-proBNP ( OR=1.049, 95% CI 1.004-1.095, P=0.032), low baseline eGFR ( OR=0.928, 95% CI 0.889-0.968, P=0.001), and high serum creatinine at discharge ( OR=1.019, 95% CI 1.009-1.029, P<0.001) were independent influencing factors of CABG-associated AKI to CKD. The clinical risk prediction model including female, preoperative blood NT-proBNP, preoperative baseline eGFR, and serum creatinine at discharge produced a moderate performance for predicting CABG-associated AKI to CKD ( AUC=0.872, 95% CI 0.806-0.939, P<0.001). Conclusion:Patients with CABG-associated AKI are at high risks for new-onset CKD. Female, preoperative high NT-proBNP, preoperative low baseline eGFR and high serum creatinine at discharge can help identify patients with a high risk of CABG-associated AKI to CKD.

Concomitant use of immobilized uridine-cytidine kinase and polyphosphate kinase for 5'-cytidine monophosphate production / 生物工程学报

Uridine-cytidine kinase, an important catalyst in the compensation pathway of nucleotide metabolism, can catalyze the phosphorylation reaction of cytidine to 5'-cytidine monophosphate (CMP), but the reaction needs NTP as the phosphate donor. To increase the production efficiency of CMP, uridine-cytidine kinase gene from Thermus thermophilus HB8 and polyphosphate kinase gene from Rhodobacter sphaeroides were cloned and expressed in Escherichia coli BL21(DE3). Uridine-cytidine kinase was used for the generation of CMP from cytidine and ATP, and polyphosphate kinase was used for the regeneration of ATP. Then, the D403 metal chelate resin was used to adsorb Ni²⁺ to form an immobilized carrier, and the immobilized carrier was specifically combined with the recombinant enzymes to form the immobilized enzymes. Finally, single-factor optimization experiment was carried out to determine the reaction conditions of the immobilized enzyme. At 30 °C and pH 8.0, 60 mmol/L cytidine and 0.5 mmol/L ATP were used as substrates to achieve 5 batches of high-efficiency continuous catalytic reaction, and the average molar yield of CMP reached 91.2%. The above method has the advantages of low reaction cost, high product yield and high enzyme utilization rate, and has good applied value for industrial production.

Advances in poly (N-isopropylacrylamide) based platforms for cell culture / 生物工程学报

Poly (N-isopropylacrylamide) (PNIPAAm), a temperature-responsive polymer, can be potentially applied to replace enzymes or cell scrapers to recover attached cells. Taking full advantage of this unique function of PNIPAAm, cells can be protected from enzymatic hydrolysis and mechanical treatment, thereby to provide ideal seed cells with high quality for biomedical fields. In this review we describe the method to facilitate cell effective adhesion and rapid detachment on thermoresponsive two dimensional surfaces, including selecting special substrate, introducing hydrophilic group, adjusting reactant ratio, controlling polymer thickness/density, providing appropriate external force, so as to effectively improve adherent cell adaptability to thermoresponsive surfaces, depress the risk of bacterial contamination and reduce the effect of low-temperature treatment on the cells. The three dimensional cell culture systems involved in temperature-sensitive microcarriers, scaffolds and gels were briefly discussed. The application based on the platforms for cell culture was also presented.

Association between endothelial dysfunction and arterial stiffness in continuous ambulatory peritoneal dialysis patients / 中华肾脏病杂志

Objective To investigate the association between endothelial dysfunction and arterial stiffness in continuous ambulatory peritoneal dialysis (CAPD) patients.Methods Ninetyfour stable CAPD patients from a single center were enrolled in this cross-sectional study.Ultrasound evaluation was conducted on brachial artery to estimate endothelial-dependent flow-mediated dilation (FMD).Automatice pulse wave velocity (PWV) measuring system was applied to examine the carotidfemoral PWV.Blood pressure and biochemical parameters were detected.Pearson's correlation and Stepwise multiple regression analysis were performed to explore the relationship between FMD and PWV.Results PWV was significantly higher in patients with diabetes as compared to those without diabetes[(13.25± 1.66) m/s vs (11.24±1.92) m/s,P ＜ 0.01].Furthermore,PWV was positively correlated with age(r=0.319,P=0.002),SBP (r=0.289,P=0.005) and C-reactive protein (r=0.211,P=0.041),was negatively correlated with albumin (r =-0.429,P =0.001) and FMD (r=-0.466,P=0.001).In multivariate regression analysis,diabetes mellitus,albumin,FMD,age and SBP were independently associated with PWV after adjustment.Conclusion Endothelial dysfunction is associated with greater arterial stiffness in CAPD patients.